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Explore CNC Meaning​ & CNC Technology

GreatLight’s blog aims to share our hard-earned knowledge on Explore CNC Meaning​ & CNC Technology. We hope these articles help you to optimize your product design and better understand the world of rapid prototyping. Enjoy!

High-speed CNC drilling and milling machines have the following main functions:

Great Light CNC Machining Services 12/01/2025 18:06

　　High Speed ​​CNC Drilling and Milling MachineDevelop the processing technology according to the technical requirements such as shape, size, precision and roughness of the workpiece, select the processing parameters, and input the compiled processing program into the controller through manual programming or automatic programming using CAM software. Once the controller has processed the processing program, it sends instructions to the servo motor. The servo motor sends control signals to the servo motor. The spindle motor rotates the tool, and the servo motors in the X, Y and Z directions control the relative movement of the tool and the workpiece along a certain trajectory, thereby realizing the cutting of the workpiece.
High-speed CNC drilling and milling machines can achieve continuous contour control of tool movement paths through linear and arc interpolation, and processing plane contours composed of linear and arc geometric elements. Planar contours composed of non-circular curves can also be processed after linear or arc approximation. Additionally, some spatial surfaces can also be processed.
Here is the pairHigh Speed ​​CNC Drilling and Milling MachineDetailed explanation of the main functions:
1. Improve production efficiency
High degree of automation: Using CNC technology, it can automatically complete complex processing tasks such as drilling and milling, greatly reducing manual operations and improving production efficiency.
Fast processing speed: Compared with traditional drills, the processing speed has been significantly improved and it can complete a large number of processing tasks in a short time.
Reduce process steps: By optimizing processing procedures, processing steps can be reduced and overall processing efficiency can be further improved.
2. Improve processing accuracy
High-precision positioning: Using transmission components such as high-precision servo motors and ball screws, combined with advanced CNC algorithms, micron-level or even higher precision positioning control is achieved to ensure the processing precision.
Tool compensation function: It has tool radius compensation and length compensation functions, which can automatically calculate and adjust the tool path, eliminate tool wear and tool change errors tool and guarantee machining precision.
Fixed-cycle processing: Applying fixed-cycle processing instructions can simplify the processing program, reduce programming workload, and improve processing accuracy.
3. Expand the scope of treatment
Versatility: Not only can it perform drilling, but it can also perform various processing operations such as milling and tapping to meet the processing needs of different parts.
Large-aperture processing: For processing large-aperture holes, it has a fully automatic CNC positioning function, which can be processed and formed in one step without the need for secondary hole expansion.
Complex shape processing: Through linear interpolation, arc interpolation or complex curve interpolation movement, high-speed CNC drilling and milling machines can process workpieces of various complex shapes.
4. Reduce production costs
Save labor costs: High-speed CNC drilling and milling machines have a high degree of automation, which can reduce reliance on labor, saving labor costs workforce.
Improve material utilization: Due to the high processing precision, the scrap rate can be reduced, the material utilization rate can be improved, and the cost can be further reduced.
Extend tool life: The tool compensation function can compensate for tool wear, extend tool life and reduce tool replacement costs.
5. Promote industrial modernization
Promote intelligent manufacturing: As a key equipment of intelligent manufacturing system, it can promote the development of manufacturing industry in the direction of intelligence and automation.
Promote technological innovation: With the continuous development and improvement of high-speed CNC drilling and milling machine technology, it can stimulate enterprises’ enthusiasm for technological innovation and product research and development .
Improve competitiveness: By introducing advanced equipment such as high-speed CNC drilling and milling machines, enterprises can improve product quality and production efficiency and increase their market competitiveness.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: Complete material surface treatment process

Great Light CNC Machining Services 12/01/2025 17:23

Surface treatment is a process that artificially forms a layer on the surface of a base material having mechanical, physical and chemical properties different from those of the base material.

The purpose of surface treatment is to meet the corrosion resistance, wear resistance, decoration or other special functional requirements of the product. Our most commonly used surface treatment methods are mechanical grinding, chemical treatment, surface heat treatment and surface spraying which involves cleaning, sweeping, deburring, removing oil and removing scale on the surface of the room. Today we will learn about the surface treatment process.

Commonly used surface treatment processes include:

Vacuum electroplating, electroplating process, anodizing, electropolishing, pad printing process, galvanizing process, powder spraying, water transfer printing, screen printing, electrophoresis, etc.

01. Vacuum plating

—— Vacuum metallization ——

Vacuum plating is a physical deposition phenomenon. That is, the argon gas is injected under vacuum and the argon gas hits the target material. The target material is separated into molecules and is adsorbed by the conductive products to form a uniform and smooth imitation metal surface layer.

Applicable materials:

1. Many materials can be vacuum galvanized, including metals, soft and hard plastics, composite materials, ceramics and glass. Among them, aluminum is most commonly used for electroplating surface treatment, followed by silver and copper.

2. Natural materials are not suitable for vacuum plating because the humidity of natural materials themselves will affect the vacuum environment.

Process cost: During the vacuum electroplating process, the part needs to be sprayed, loaded, unloaded and sprayed again, so the labor cost is quite high, but it also depends on the complexity and the quantity of the piece.

Environmental impact: Vacuum electroplating has very little environmental pollution, similar to the impact of spraying on the environment.

02.Electropolishing

—— Electropolishing ——

Electropolishing is an electrochemical process in which the atoms of a workpiece immersed in an electrolyte are converted into ions and removed from the surface due to the passage of current, thereby achieving the effect of removing fine burrs and increasing the brightness of the surface of the room.

Applicable materials:

1. Most metals can be electrolytically polished, which is most often used for surface polishing of stainless steel (especially suitable for nuclear grade austenitic stainless steel).

2. Different materials cannot be electropolished at the same time, or even placed in the same electrolytic solvent.

Process cost: The whole electropolishing process is basically carried out automatically, so labor costs are very low. Environmental impact: electropolishing uses less harmful chemicals. The whole process requires a small amount of water and is simple to use. In addition, it can prolong the properties of stainless steel and delay the corrosion of stainless steel.

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03. Pad printing process

—— Pad printing ——

Being able to print text, graphics and images on the surface of irregularly shaped objects is now becoming an important special impression.

Applicable materials:

Pad printing can be used on almost any material except materials softer than silicone pads, such as PTFE.

Process cost: low mold cost and low labor cost.

Environmental impact: As this process is limited to soluble inks (which contain harmful chemicals), it has a significant impact on the environment.

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04. Galvanizing process

—— Galvanizing ——

Surface treatment technology that coats the surface of steel alloy materials with a layer of zinc for aesthetics, rust prevention, etc. The zinc layer on the surface is an electrochemical protective layer that can prevent metal corrosion. The main methods used are hot-dip galvanizing. and electro-galvanized.

Applicable materials:

Since the galvanizing process relies on metallurgical bonding technology, it is only suitable for surface treatment of steel and iron.

Process cost: no casting costs, short cycle time/average labor cost, because the surface quality of the part largely depends on the manual surface treatment before galvanizing.

Environmental impact: Since the galvanizing process increases the life of steel parts from 40 to 100 years and prevents rust and corrosion of parts, it plays a positive role in environmental protection. In addition, galvanized parts can be returned to the galvanizing tank after their service life expires, and repeated use of liquid zinc will not produce chemical or physical waste.

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05. Electroplating process

—— Electroplating ——

A process that uses electrolysis to attach a metal film to the surface of parts, thereby preventing oxidation of the metal, improving wear resistance, conductivity, reflectivity, corrosion resistance and improving aesthetics . The outer layers of many parts are also galvanized.

Applicable materials:

1. Most metals can be galvanized, but different metals have different levels of purity and plating effectiveness. The most common are: tin, chrome, nickel, silver, gold and rhodium.

2. The most commonly used plastic for electroplating is ABS.

3. Metallic nickel cannot be used for plating products that come into contact with skin because nickel is irritating and toxic to the skin.

Process cost: no casting costs, but accessories are required to attach the parts/Time cost depends on temperature and metal type/Labor cost (medium-high), depends on the type of specific electroplated parts, such as silverware and jewelry, which requires a lot of electroplating. Highly skilled workers are required to operate it due to its high requirements for appearance and durability.

Environmental Impact: A large number of toxic substances are used in the electroplating process, so professional diversion and extraction are required to ensure minimal environmental impact.

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06. Water Transfer Printing

—— Hydroelectric transfer printing ——

It is a method of printing color patterns on transfer paper onto the surface of three-dimensional products using water pressure. As people’s requirements for product packaging and surface decoration increase, water transfer printing is more and more widely used.

Applicable materials:

All hard materials are suitable for water transfer printing, and materials suitable for spraying should also be suitable for water transfer printing. The most common are injection molded parts and metal parts.

Process cost: There is no molding cost, but you need to use a device to transfer multiple products to water at the same time. The time cost generally does not exceed 10 minutes per cycle.

Environmental impact: Compared to spraying products, water transfer printing more fully applies print coatings, reducing the risk of waste leakage and material waste.

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07.Screen printing

—— Screen printing ——

Through the compression of the scraper, the ink is transferred to the substrate through the mesh of the graphic part, forming the same graphic and text as the original. Screen printing equipment is simple, easy to operate, easy to print and make plates, low cost and strong adaptability.

Common printed materials include: color oil paintings, posters, business cards, binding covers, product signs and printed and dyed textiles, etc.

Applicable materials:

Almost any material can be screen printed, including paper, plastic, metal, ceramic and glass.

Process cost: The mold cost is low, but it still depends on the number of colors, because each color needs to be plated separately. Labor costs are high, especially when it comes to multi-color printing.

Environmental impact: Light-colored screen printing inks have less impact on the environment. However, inks containing PVC and formaldehyde contain harmful chemicals and must be recycled and treated in time to avoid contamination of water resources.

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08.Anodizing

—— Anodic oxidation ——

Mainly aluminum anodizing, which uses electrochemical principles to generate an Al2O3 (aluminum oxide) film on the surface of aluminum and aluminum alloys. This oxide film has special properties such as protection, decoration, insulation and wear resistance.

Applicable materials:

Aluminum, aluminum alloy and other aluminum products

Process cost: During the production process, the consumption of water and electricity is considerable, especially in the oxidation process. The heat consumption of the machine itself requires the constant use of circulating water for cooling, and the energy consumption per ton is often around 1,000 degrees.

Environmental impact: Anodizing is not great in terms of energy efficiency. At the same time, during the production of aluminum electrolysis, the anode effect also produces gases that have harmful side effects on the atmospheric ozone layer.

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09. Metal brushing

——Metal wired——

This is a surface treatment method that uses grinding products to form lines on the surface of the workpiece to achieve a decorative effect. According to the different textures after stretching, it can be divided into: straight grain drawing, random grain drawing, wavy grain and spiral grain.

Applicable materials: Almost all metal materials can use the metal drawing process.

Process cost: The process method is simple, the equipment is simple, the material consumption is very low, the cost is relatively low, and the economic benefits are high.

Environmental impact: pure metal products, without paint or chemical substances on the surface, do not burn at a high temperature of 600 degrees, do not produce toxic gases, and comply with fire protection and environmental protection requirements environment.

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10. Decoration in the mold

——In-mold decoration-IMD——

This is a casting method in which a diaphragm with a printed pattern is placed in a metal mold, and casting resin is injected into the metal mold to join the diaphragm, so that the diaphragm with the printed pattern and the resin are integrated and solidified. into a finished product.

Applicable materials: plastic surface

Process cost: Only one set of molds is needed, which can reduce costs and labor hours for highly automated production. There is a one-time injection molding method that can carry out molding and decoration at the same time.

Environmental impact: This technology is green and environmentally friendly, avoiding pollution caused by traditional spray painting and electroplating.

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Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

CNC Knowledge: The harm of cutting fluid to the human body should not be ignored!

Great Light CNC Machining Services 12/01/2025 16:21

Any chemical can be potentially harmful to human health! Chemical substances contained in cutting fluids can enter the human body through contact with skin, breathing, accidental consumption, splashing into the eyes, etc.

Friends engaged in mechanical processing, the best way is to check the MSDS file of the product you are using! Any regular product will have such a document detailing the possible dangers of its product to users and the corresponding countermeasures.

Today’s machine tools all operate at high pressure and the cutting fluid produced is atomized without protection and can easily be inhaled into the lungs. Therefore, high-end machine tools are equipped with smoke recovery devices. If your machine tool is not installed, it will take 5 seconds to enter operation after opening the safety door.

The most typical example is that nitrite, a powerful carcinogen and cheap anti-rust additive, can be detected in the cutting fluid used by most domestic factories! Our country still has no corresponding laws and regulations prohibiting it!

The harm of mineral oil for the human body is certain. Developed countries no longer use emulsified oil containing more mineral oil.

Its content is approximately 35%. Synthetic cutting fluids do not contain mineral oil, but have poor lubricating properties. To solve this problem, a micro-emulsified cutting fluid appeared, containing about 17% mineral oil, which significantly reduces damage to the human body.

Some additives are harmful to the human body. Some additives, such as those containing sulfur and chlorine, are banned in developed countries. Therefore, it is recommended to use green and environmentally friendly cutting fluid. EU environmental protection standard goes through SGS inspection. The city of Shenzhen in my country has already made this request.

At the same time, the cutting fluid also seriously pollutes the environment, and the recycling cost of the cutting fluid is higher than its own purchase price. For your own physical and mental health, it is necessary to wait a certain amount of time before entering the security gate.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

How to clean the cutting tools of a twin-spindle machining center?

CNC Technology: How to clean the cutting tools of a twin-spindle machining center?

Great Light CNC Machining Services 12/01/2025 16:17

How to clean the cutting tools of a twin-spindle machining center? Cleaning the cutting tools of a twin-spindle machining center is an important step to guarantee machining precision and extend tool life. Here are some specific cleaning steps and considerations:

1. Preparation before cleaning

Turn off the power: Before any cleaning work, be sure to turn off the main power switch of the machine tool and ensure that the machine tool is turned off to avoid electric shock accidents.

Prepare the tools: prepare a clean cotton cloth or special cloth, a vacuum cleaner or air gun (for cleaning hard-to-reach corners), detergent suitable for machine tool materials, lubricating oil and grease, screwdrivers, wrenches and other tools (for removal and installation). protective cover and other parts).

2. Cleaning Steps

To clean the tool surface:

Use a clean cotton cloth or wipe to wipe the surface of the tool to remove dust and oil.

Be careful not to use cleaners containing corrosive substances to avoid damaging the tool surface.

Clean the tool magazine and tool arm:

Open the protective cover of the machine tool and use a vacuum cleaner or pneumatic gun to clean dust and chips from the tool magazine and tool arm.

Pay special attention to cleaning the tool arm, tool magazine and other parts of the tool magazine. These parts are prone to accumulation of dust and chips, affecting the accuracy and life of the machine tool.

Clean the guide rails and lead screw:

Use a brush and detergent to clean chips and dust from the surface of the guide rails and screws.

After cleaning, apply an appropriate amount of oil or grease to reduce friction and wear.

Check the condition of the tool:

During the cleaning process, inspect the knives for wear, damage, or rust.

If necessary, promptly replace worn or damaged tools.

3. Precautions

Safety First: During the cleaning process, be sure to follow the safe operating procedures of the machine tool to ensure personal safety and normal operation of the machine tool equipment.

Regular cleaning: It is recommended to regularly clean and maintain the cutting tools of the twin-spindle machining center to maintain their good working condition and processing precision.

Anti-rust treatment: After cleaning, carry out anti-rust treatment on the cutter, such as applying anti-rust oil, etc. to prevent the cutter from rusting during storage.

Professional maintenance: For complex cleaning and maintenance work, it is recommended to entrust the operation to professional machine tool maintenance personnel or technicians.

In summary, cleaning the tools of a twin-spindle machining center requires following certain steps and precautions to ensure the cleaning effect and normal operation of the machine tool equipment.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

CNC Knowledge: Sharing study notes on high speed dry cutting gear hobbing

Great Light CNC Machining Services 12/01/2025 15:20

Original woody kissme

High-speed dry gear hobbing has appeared in the world for many years, but its domestic application is not particularly common. Recently, I sorted out the relevant content on high-speed dry cutting and gear hobbing, wrote a study note and saved it. Interested friends can take the time to take a look.

The emergence of dry gear cutting is mainly due to several factors:

In recent years, environmental safety requirements have continued to increase around the world and many companies are seeking to obtain ISO14000 certification to meet international environmental standards. As part of this effort, the shop designs and implements coolant-free metal cutting methods, not only to improve the working environment but also to protect the environment. However, in turning and milling applications, there are few dry cutting machine tools that do not use coolant entirely, although some convert from wet cutting to MQL (minimum lubrication). Among them, the field of gear cutting, especially gear hobbing, is developing into complete dry cutting machine tools.

Wet cutting gear hobbing

In gear hobbing applications, dry cutting methods using carbide hobs have been advocated in the past, but have not gained widespread acceptance because the problem of tool chipping has not been resolved. Since then, due to the progress of surface treatment technology and the emergence of high-speed steel coated hobs and dry hobbing machines, gear dry hobbing technology has developed rapidly.

Advantages of dry cutting

In fact, coolant can produce oily contaminants in the factory and negatively impact the environment. Dry cutting not only solves these environmental problems, but also can effectively improve cutting efficiency and reduce life cycle costs with its low operating costs.

From an environmental perspective, the benefits of using dry hobs have prompted companies like Mitsubishi, Gleason, Liebherr and others to investigate the use of high speed steel hobs for hot cutting. dry, which are more stable than carbide hobs. Factory testing begins at the same speed as a normal wet cooktop with a high speed steel cooktop.

The results were surprising. High-speed cutting seemed to be an ideal cutting method because no abnormal wear or temperature increase occurred on the parts by increasing the cutting speed to twice the normal cutting speed. However, lack of coolant also creates significant problems that hinder the practical application of dry cutting. These problems include flying chips and heat generated by chips, which has prompted machine tool manufacturers to develop a new type of dry hobbing machine. The following uses a three-edged high-speed roller as an example to discuss the functions of the machine tool and the tool requirements required for dry cutting.

The capacity of the main motor of the machine tool is an important issue. In wet hobs, high speed steel hobs are generally used for sharpening workpieces (hardened steel) at cutting speeds of 80 to 160 m/min. However, the cutting speed of dry hobbing is 160-400m/min, which is 2-2.5 times that of wet cutting, or even higher. Since the cutting power is directly proportional to the cutting force and spindle speed, the dry trimming machine requires more than 2-2.5 times the capacity of the main motor of the dry trimming machine. traditional water. That is, it is possible to convert a traditional cutting machine into a dry cutting machine, but in many cases the cutting conditions are limited by the capacity of the main motor.

Additionally, measures should be taken to prevent chips from dispersing and accumulating. In wet gear cutting, coolant is used to clean the cutting point, cool parts, tools and accessories, and expel chips to the outside of the machine. On the other hand, in dry rolling, these functions are provided by air and shields.

One strategy employed uses a fully sealed cutting area. Cutting chips carrying kinetic energy bounce around the cutting zone and pass through gaps as small as a few millimeters, are ejected from the cutting zone and accumulate on machine parts. Therefore, to avoid deterioration and breakdown of machine performance, the cutting area must be completely sealed.

On the column side, due to the vertical and rotational movement of the hob headstock, a double cover design (one mounted on the hob saddle and the other on the column) is used to prevent chips from flying away. Additionally, all pipes entering the machine are connected via relay modules that separate the inside and outside of the cutting area. Of course, cable and pipe sections placed in the cutting area must be protected from hot cutting debris.

On the tailstock side, in order to prevent chips from escaping during gear cutting, the opening of the separation cover used for rotating the spindle is closed by a baffle. The top of the bed is covered with a steep-slope stainless steel cover with a low friction coefficient, which can collect the falling chips into a chip conveyor installed at the bottom of the bed to prevent the chips from flying out of the bed. cutting surface and build up.

Then there is the blade cover. Stainless steel cutter head covers prevent flying chips from accumulating on the cutter head or entering gaps between the main engine or machine components.

Dry honing does not have the ability to discharge coolant, which can easily cause chips to adhere to the cutting tool, resulting in defects on the gear tooth surface and chip deposition.

Machine tool manufacturers have provided corresponding countermeasures to solve these problems. Most use flat blow nozzles to generate airflow to remove waste. The guard installation angle should take into account chip bounce and the inclined surface of the fixture to prevent chips from entering the cutting area. Additionally, blown air is used to remove chips accumulated on the top of the workpiece, and a baffle is installed near the outer circumference of the hob to prevent flying chips from being caught and spinning with it. the hob.

When dry cutting, chip evacuation measures are crucial because most of the heat generated during dry cutting is transferred to the cutting chips. Additionally, because the process does not involve coolant, the heat generated by the machine must be controlled by other means. These measures include:

Inner cover: To prevent heat transfer to the fuselage, a low thermal conductivity stainless steel cover is installed for thermal insulation through an air layer.

Dust collector to release cutting heat: In order to prevent the heat of the chips from being transferred to the machine body by convection, the machine uses a dust collector to capture the tiny chips generated during the dry cutting process to provide a Air flow to remove cutting heat from the machine.

Hose and cable protection: Use steel braided hoses for hydraulic and other connections, as flying debris at high temperatures can cause oil or air leaks. To prevent breakage due to chips, the connection cables are protected by heat-resistant plastic sheaths. Controlling the heat generated by the cell requires the use of non-contact seals. The oil seal used on the spindle, which generates a lot of heat, was replaced with a non-contact seal, which significantly reduced the heat generated.

The bearings are lubricated with an oil mist. When rotating at high speed, apply a large amount of lubricant to the bearings to dissipate heat, and some heat will also be generated due to stirring losses. However, applying too little lubricant is not effective in dissipating heat. That’s why we use an oil mist lubrication method to ensure the bearings generate minimal heat. This method also prevents foreign objects from entering the joint due to the difference in atmospheric pressure.

Features of dry rolling using high-speed hobs

First of all, how is dry rolling done? Dry honing gears using traditional TiN-coated hobs will experience abnormal wear, but TiAIN-coated hobs wear much less under the same conditions. This is due to the following reasons:

Firstly, a coating film with excellent wear resistance is used. When dry cutting, the hob teeth are exposed to extremely high temperatures due to lack of coolant. Changes in coating film composition at high temperatures. In TiN coating, the Ti component of the coating film is oxidized and converted to a brittle TiO2 component, making it unable to maintain its original wear-resistant properties. In contrast, in the case of the TiAlN film, Al is selectively oxidized at a depth of approximately 0.5 μm from the surface, and a rigid film is produced. Studies have shown that due to the role of this film, the TiAIN coating has high wear resistance.

Second, a protective film is created by depositing cooking chips. When cutting gears under water, the extreme pressure additives contained in the coolant prevent deposits of gear cutting chips. However, when dry cutting, the cutting chips are easily deposited to protect the tool surface and reduce wear. Figure 7 shows an image of the composition of the cutting edge after cutting. The white part consists of hob chips (Fe), which can be seen deposited on the cutting surface of the hob.

To compare the different types of hobs, Table 2 shows the hobs used in various gear hobbing methods. Although carbide hobs can be used for gear hobbing at extremely high speeds, they are prone to chipping due to their low toughness. Dry cutting using high-speed hobs offers high productivity and tool stability and is therefore by far the most advantageous method of gear hobbing.

Important notes on using dry baking trays

As previously stated, the capacity of the main engine must be increased. If the cutting speed increases from 100 m/min to 200 m/min by introducing dry cutting, the required cutting power will be doubled, coupled with the increase in the no-load power of the machine, so that the capacity of the main engine must be increased.

Steps can also be taken to minimize chip adhesion. One approach is to coat to reduce the affinity between tool and workpiece and prevent hobbing chips from adhering to the tool edge. It should also be combined with suitable air jets to remove chips adhering to the cutting edge and remove flying chips at the cutting point.

Heat buildup increases with longer cycle times and more heat builds up in the workpiece. In other words, the longer the tool is in contact with the workpiece, the hotter the workpiece becomes. Increasing the cutting speed or feed rate can reduce the workpiece temperature. Therefore, it is necessary to set optimal hobbing parameters based on the relationship with workpiece accuracy, tool life, etc.

recent developments

The maximum speed for dry cutting of high speed steel used to be 200 m/min. However, with the development of new coating films with better high temperature oxidation resistance properties than TiAlN, this speed has been increased to 250 m/min, and in some cases the maximum linear speed has even reached 450 m/min. For hobbing the rear cutting edge of a workpiece (m2.25, 52T, 23°LH, B35 mm) using a hob (3 threads, 14 edges) under hobbing conditions specific (cutting speed 250 m/min, axial feed) Wear condition 2.4 mm, no moving knife). The new coated cooktops wear half as much as TiAIN cooktops.

Finally

In the area of ​​dry cutting, higher cutting speeds will be sought in the future. For cutting tools, in order to withstand high temperature gear cutting, it is necessary to develop base materials with excellent heat resistance and coating materials with excellent oxidation resistance.

Although the development of dry cutting machines continues, gear shapers are steadily moving toward dry cutting. In addition, there is also a high demand for gear cutting production lines consisting of only dry cutting machines. The development of dry gear shaving machines is therefore worth looking forward to, although gear shaving is gradually being replaced by gear grinding.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: CNC lathe operating skills and experience

Great Light CNC Machining Services 12/01/2025 14:19

Programming skills

Due to the high precision requirements for processed products, considerations when programming are:

First, consider the sequence of processing parts:

1. Drill holes first, then flatten the end (to avoid material removal during drilling);

2. Rough turning first, then fine turning (this is to ensure the precision of the parts);

3. Process parts with large tolerances first, and process parts with small tolerances last (this is to ensure that the surface of small tolerances is not scratched and to prevent the parts from deformation).
According to the hardness of the material, select a reasonable rotation speed, feed rate and cutting depth: 1. Choose high rotation speed, high feed speed and large cutting depth for materials made of carbon steel. For example: 1Gr11, choose S1600, F0.2 and cutting depth 2mm; 2. For carbide, choose low speed, low feed and low cutting depth. For example: GH4033, choose S800, F0.08 and cutting depth 0.5mm; 3. For titanium alloy, choose low speed, high feed and low cutting depth. For example: Ti6, select S400, F0.2, cutting depth 0.3mm. Take the processing of a certain workpiece as an example: the material is K414, which is a super-hard material, after many tests, S360, F0.1 and cutting depth of 0.2 were finally selected before before a qualified part is processed.

Knife Adjustment Skills

Tool setting is divided into tool setting instrument setting and direct tool setting. The tool setting techniques mentioned below are direct tool setting.

Common tool settings

First select the center of the right end face of the workpiece as the tool calibration point and set it as the zero point after the machine tool returns to the origin, each tool that needs to be used is calibrated with the center of the right end. face of the part as zero point; When the tool touches the right end face, enter Z0 and click the measurement. The measured value will be automatically saved into the tool offset value, which means the tool alignment on the Z axis is correct.

Tool setting X is for test cutting. Use the tool to reduce the outer circle of the part. Measure the value of the outer circle to be rotated (for example, X is 20mm) and enter X20. The offset value will automatically save the measured value. The axis is also aligned;

This tool setting method will not change the tool setting value even if the machine tool is turned off and restarted. It can be used to produce the same parts in large quantities for a long time, and there is no need to recalibrate the tool. tool after stopping the lathe.


Debugging Tips

After the parts are programmed and the knife adjusted, test cutting and debugging are necessary to prevent program errors and tool setting errors from causing collisions with the machine.

You should first carry out no-load stroke simulation processing, facing the tool in the machine tool coordinate system and moving the entire workpiece to the right by 2-3 times the total length of the part, then starting the simulation processing. processing is completed, confirm that the program and tool calibration are correct, and then start processing the workpiece. After the first part is processed, first conduct self-inspection to confirm that it is qualified, and then find a full-time job. Inspection. Only after the full-time inspection confirms that it is qualified, the debugging is completed.


Complete parts processing

After the first part is trial cut, the parts will be produced in batches. However, qualifying the first part does not mean that the entire batch of parts will be qualified, because during the processing process the tool will wear out due to wear. different processing materials. If the tool is soft, tool wear will be low. If the processing material is hard, the tool will wear out quickly. Therefore, during the processing process, it is necessary to frequently check and increase and decrease the tool compensation. value timely to ensure the parts are qualified.

Tool wear processes and dulling standards

Let’s take as an example a part already machined

The processing material is K414, and the total processing length is 180mm. Because the material is very hard, the tool wears out very quickly during processing. From starting point to end point, there will be a slight deviation of 10-20mm due to wear. tool wear. It is therefore necessary to artificially add 10 ~20mm to the program, in order to ensure that the parts are qualified.

The basic principles of processing: Rough processing should first remove excess material from the workpiece, and then finish processing. Thermal degeneration should be avoided during processing of the part. There are many possible reasons for vibrations. due to excessive load; it may be the resonance of the machine tool and the workpiece, or it may be the machine tool; Insufficient rigidity can also be caused by tool dullness. We can reduce vibration through the following methods: reduce the amount of cross feed and processing depth, check whether the workpiece is firmly clamped, increase the tool speed and reduce the speed. Reduce the resonance and check if it is necessary to replace the tool with a new one.


Tips for Preventing Machine Tool Collisions

Machine tool collisions will cause serious damage to the precision of the machine tool, and the impact will be different according to different types of machine tools. Generally speaking, the impact will be greater on machine tools that are not very rigid. Therefore, for high-precision CNC lathes, collisions must be eliminated. As long as the operator is careful and masters certain anti-collision methods, collisions can be completely avoided.

The main reasons for collisions:

☑ The diameter and length of the tool are incorrectly entered;

☑ Incorrect entry of part dimensions and other associated geometric dimensions, as well as errors in the initial position of the part;

☑ The workpiece coordinate system of the machine tool is incorrectly adjusted or the zero point of the machine tool is reset during the machining process, and machine tool collisions mainly occur during the rapid movement of the machine tool. machine tool. the most harmful and must be absolutely avoided. Therefore, the operator must pay special attention to the initial phase of the program execution by the machine tool and when the machine tool changes tools. At this time, a program editing error occurs and the tool diameter and length are entered incorrectly. , a collision will easily occur. At the end of the program, if the CNC axis retraction sequence is wrong, a collision may also occur.

In order to avoid the above collision, the operator should give full play to the functions of the five senses when operating the machine tool. Observe for abnormal movements of the machine tool, sparks, unusual noises and sounds, vibration and odor burned. If an anomaly is discovered, the program must be stopped immediately. The machine tool can only continue to work after the machine tool problem is resolved.

In short, mastering CNC machine tool operational skills is a step-by-step process and cannot be achieved overnight. It is based on mastery of basic machine tool operations, basic machining knowledge and basic programming knowledge. CNC machine tool operating skills are not static. This is an organic combination that requires the operator to give full play to his imagination and practical abilities, and it is innovative work.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

Inclined Bed CNC Lathe: A Precision Assistant for the Manufacturing Industry

Great Light CNC Machining Services 12/01/2025 13:58

In the field of modern machining, CNC lathes play an important role. With the progress of science and technology and the growth of industrial demand, inclined bed CNC lathes are distinguished by their efficient design and processing capabilities, becoming an important choice for many manufacturing enterprises to improve production efficiency and product quality.
Inclined bed CNC lathe is a machine tool specially used for turning. It adopts an inclined bench design, which has significant advantages over the traditional horizontal bench. This design not only improves the efficiency of chip removal and reduces the impact of chips on the machining process, but also improves the operator’s line of sight, making it more intuitive to observe the cutting situation. ‘machining. In addition, the inclined bed structure helps to improve the overall rigidity of the machine tool and reduce vibration during processing, ensuring higher processing precision and surface quality.
1. Advantages of the design
The design of inclined bed CNC lathe intelligently combines mechanical principles and practical application requirements. Its inclined bed is typically set at an angle of 30 or 45 degrees, a design that makes gravity an advantageous factor in the chip evacuation process. Chips slide more naturally, preventing their accumulation in the work area, reducing the risk of tool wear and damage to the workpiece caused by chip entanglement. At the same time, the inclined layout also makes more reasonable use of the internal space of the machine tool, which is conducive to the installation of more functional modules, such as automatic tool changers, power heads, etc. ., to meet multiple and complex needs. process processing requirements.
2. Performance Characteristics
1. Precision control: Precise control of feed and speed is achieved through the CNC system to ensure that each cut can achieve ideal dimensional accuracy.
2. Efficient production: The fast-response servo motor and optimized transmission system can realize high-speed and high-precision continuous processing, greatly shortening the production cycle.
3. High degree of automation: supports a variety of automation functions, including automatic loading and unloading, automatic tool changing, etc., reducing the need for manual intervention and improving the level automation of the production line.
4. Easy Maintenance: Open structure and easy-access key components facilitate daily inspection and maintenance, extending the life of the equipment.
3. Scope
Inclined bed CNC lathes are widely used in many industries such as automotive parts, aerospace and medical equipment. It is ideal for products requiring high volume production and strict precision requirements. For example, in the automotive industry it can be used to process key components such as engine blocks and crankshafts; In the field of medical equipment, it is suitable for manufacturing small delicate implants or surgical tools.
4. Future development
With the in-depth development of the concept of intelligent manufacturing, inclined bed CNC lathes will continue to evolve in the direction of intelligence and integration. In the future, we will see the emergence of smarter towers integrating IoT technology, big data analytics and artificial intelligence algorithms. They will have functions such as self-diagnosis and predictive maintenance, further improving treatment efficiency and service quality.
　　

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

CNC Knowledge: Reverse tower and German FAME!

Great Light CNC Machining Services 12/01/2025 13:18

Most of our common lathes have a horizontal structure with a horizontal spindle, but this company has used reverse thinking to make a reverse lathe a new category of machine tools.
This is the German EMAG group. As the inventor of the reverse lathe, he introduced the reverse lathe in 1992, setting a new standard for lathe in the industry.

Furthermore, EMAG has never stopped innovating and developing.In turning, grinding, laser welding, electrochemistry, induction heat treatmentIn addition to gear hobbing technology, it has launched a series of innovative technologies and products, and continued to increase in the field of high-end machine tools and market share, creating a typical “hidden champion” in the German machine tool industry.

The VLC 200 GT vertical turning and grinding lathe is specially designed for processing disc-type parts of automobile transmission gears. The highlight is that the two machining processes are alternately combined intelligently and quickly depending on the geometry and quality requirements of the workpiece. The user not only benefits from efficient turning and grinding in just one clamping, but also benefits from its extremely high price-performance ratio. The machine tool takes up little space and can be flexibly connected to workshop equipment.
Machine loading of the entire process, including dressing, can be carried out at extremely high speeds thanks to the integrated loading and unloading spindle typical of EMAG. EMAG also optimized the mechanics of the treatment area doors in order to reduce unproductive times. After the spindle and workpiece reach the machining position, hard rough turning of the shoulder and bore is performed in rapid succession. There are then only a few microns left on the transmission pinion.

This also makes the subsequent grinding process much shorter, which can be completed with corundum or CBN grinding wheels. If only a small amount of material needs to be removed after turning, the grinding wheel can be sized specifically for the final quality required, allowing the VLC 200 GT to achieve surfaces with an average roughness Rz below the process values ​​of 1, 6 microns. and guarantee process security.

Overall, the versatile process technology also opens up more possibilities for the user: depending on requirements, internal and external grinding spindles, beveling tools, integrated tool holders or the proven EMAG tool turret to 12 stations can be used. Tool costs are reduced because grinding wheel wear is slowed and the need for dressing is reduced.

If dressing is required, the VLC 200 GT is specially equipped with a separate diamond-coated dressing roller. The machine tool has the best equipment such as independent rotary dressing system and distance control monitoring, which can fully exploit the advantages of CBN‍ technology. The integrated measuring heads detect the diameter and length of the components after the clamping process, ensuring permanent process reliability and high-quality machining.

EMAG’s R&D staff also attach great importance to user comfort and use wide doors to facilitate access to the treatment area. Tools and pliers are easy to use and can be changed quickly and easily.

Helpline: 13522079385

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: Water-guided laser processing technology of DD6 alloy micropores

Great Light CNC Machining Services 12/01/2025 12:15

As the performance of aircraft engines continues to improve, the operating temperature of the combustion chamber also becomes higher and higher. In order to improve the performance of aircraft engine turbine blades under high temperature conditions, air film holes are usually made on the blade surface. The hole processing quality of the air film is crucial to its bearing capacity and service life. Laser processing technology is currently one of the main air film hole preparation methods. The laser light sources used are mainly divided into long pulse laser, short pulse laser and ultra-short pulse laser. Long pulse laser and short pulse laser will produce microcracks and recast layers during the hole making process. The ultra-short pulse laser has almost no thermal damage to the material, but it has higher requirements for processing equipment and working environment. the treatment effectiveness is not high. Therefore, in order to meet the needs of high-quality air film hole processing, a water-guided laser processing method was proposed, a water-guided laser processing system was constructed by us themselves and a hole making test of the DD6 alloy was carried out. . The test successfully produced 400 µm diameter straight holes and 45° inclined holes. The processed air film holes had almost no recast layers, microcracks and no heat-affected zones, providing an effective technical reference for air film hole processing.

01

Preface

With the rapid development of aviation technology, high thrust-to-weight ratio and low fuel consumption have become the main development trends of aircraft engines. Therefore, the working environment of turbine blades has become more and more rigorous, which has imposed higher design requirements. , manufacturing and performance of turbine blades.[1]. At present, turbine blades are mainly made of nickel-based single-crystal superalloys, and air film holes are made on their surfaces to meet the requirements of high temperature resistance.[2]. Research shows that film cooling technology plays a 60-70% role in increasing the operating temperature of turbine blades. Therefore, the production of high-quality air film holes is crucial to improve the bearing capacity and service life of aircraft engines.

Laser processing technology is one of the main processing methods for preparing air film holes in aircraft engine turbine blades. Researchers at home and abroad have carried out a lot of research on laser processing of air film holes.[3]. At the beginning, the laser light source for laser processing of air film holes mainly used millisecond (ms) laser.[4]A millisecond laser is used to create air film holes on the surface of the DD6 alloy. The obtained air film holes have thermal defects such as recast layer and microcracks, and the surface roughness is poor. With the emergence of ultrashort pulse laser, its use for treating air film holes has been widely studied. Zhang Ruifeng et al.[5]The picosecond laser is used to process the gas film holes on the surface of the nickel-based single crystal alloy. The resulting hole wall has no recast layer or heat affected zone. However, due to the impact of the plasma, slight cracking is caused on the hole. wall and surface. The femtosecond laser has great advantages in material processing due to its extremely short pulse time and extremely high peak power.[6]A femtosecond laser hole creation test was carried out on a nickel-based alloy sample, and the relationship between the energy parameters (femtosecond laser pulse width, laser wavelength and repetition frequency) and the diameter and depth of the micro-holes was studied quantitatively. No recast layer, microcracks and heat affected zone. However, the femtosecond laser has higher requirements for equipment and environment, and the processing efficiency is low.

In response to the above problems, this article proposes water-guided laser processing technology. Water-guided laser processing technology uses the principle of total reflection of the laser in the water beam and uses water as an optical fiber to guide the laser to the surface. of the workpiece.[7]. Due to the scrubbing and cooling effect of the high-speed jet, the water-guided laser has a significant inhibitory effect on the thermal damage caused by the treatment. The processed holes have high processing quality, extremely low heat affected zones and minimal recast layers. .[8，9]. At the same time, water-guided lasers mainly use nanosecond lasers as the laser light source, which have higher processing efficiency. Therefore, this paper uses water-guided laser processing technology to process the air film holes of aircraft engine turbine blades. By comparing the quality achieved using conventional laser processing methods, the processing advantages of water-guided laser are established. The impact of different powers on the processing quality was studied, and straight holes and 45° inclined holes were successfully produced, providing a new solution for the field of air film hole processing.


02

Experimental analysis

2.1 Material analysis

The ultimate goal of this research is to produce high-quality air film holes on aircraft engine turbine blades. The structure is shown in Figure 1. Turbine blades are often cast from single-crystal nickel-based high-temperature alloys. This type of alloy has high strength and hardness as well as excellent resistance to high temperatures and corrosion. The test uses the nickel-based high-temperature single-crystal alloy brand DD6 as the research object, with a specification of 20mm × 20mm × 2.6mm. The chemical composition and physical properties of the material are shown in Table 1 and Table 2.

Figure 1 Structure of turbine blades

Table 1 Chemical composition of nickel-based single-crystal alloy DD6 (mass fraction) (%)

Image WeChat_20231218104025.png

Table 2 Physical properties of nickel-based single-crystal alloy DD6

Image WeChat_20231218104028.png

Before testing, the sample must be cleaned with absolute ethanol. Once the surface is free of stains, it is placed in an ultrasonic cleaner. The temperature is set at 50°C and the frequency is 40 kHz. After ultrasonic cleaning for 15 minutes. , it is dried. After the test, in order to facilitate the observation of the degree of laser ablation on the sample surface, the sample surface was ground and polished.

2.2 Hole making characteristics

The laser hole making test adopts the ring cutting hole making method, that is, controlling the XY working platform to control the movement trajectory of the workpiece in a series of circles concentric. The processing process is shown in Figure 2, and the air film hole quality requirements are shown in Table 3.

Image WeChat_20231218104032.png

Figure 2 Schematic diagram of ring cutting and hole making processing process

Table 3 Quality requirements for air film holes (unit: μm)

Image WeChat_20231218104035.png

2.3 Test equipment

The light source of the processing system used in this article is Pulse 532-50-LP laser produced by Suzhou Yinggu. Table 4 shows the relevant laser parameters. The nozzles involved in the test include three specifications: 60 μm, 80 μm and 100 μm (diameter). The diameter of the focused spot in the center of the nozzle is about 30 µm, which meets the coupling requirements.

Table 4 Laser Parameters

Image WeChat_20231218104038.png


03

Water guide laser treatment method

3.1 Principle of water-guided laser action

When light is projected from water to air, if the angle of incidence is greater than a certain value, the light will be completely reflected at the water-air interface and transmitted with the jet. The working principle of water-guided laser processing technology is shown in Figure 3.[10]. The focused laser passes through the glass window and water layer and converges on the top surface of the nozzle, where it couples with the high-pressure jet emitted by the nozzle to form a coupled energy beam. The laser energy is not focused directly on the workpiece surface, but is transmitted to the workpiece surface through the water jet in capillary laminar flow. After the water jet in the stable range collides with the workpiece, the laser energy guided by the water jet is absorbed by the material surface, causing the material in the area to melt and evaporate. ablation. At the same time, the high-speed jet removes molten material, excess heat and residue, effectively scouring and cooling the treatment area.[11]。

Image WeChat_20231218104041.png

Figure 3 Working principle of water-guided laser treatment technology

3.2 Water guide laser treatment system

The water guided laser processing system mainly includes 4 parts, namely coupling system, optical transmission system, water supply system and motion control system. The core part is the coupling system, which is used to generate fine water jets, couple the laser to the water beam, and observe and adjust the coupling state in real time. The optical transmission system includes lasers and adjustment lens groups such as collimator beam expanders, which are used to shape the beam generated by the laser into a coupleable beam. The water supply system provides high-pressure fine water jets, and the motion control system is used to control the motion status of the machine tool. The principle and actual construction of the water-guided laser processing system are shown in Figures 4 and 5.

Image WeChat_20231218104045.png

Figure 4 Principle of water-guided laser treatment system

1—Laser 2—Shutter 3—Beam expander 4, 5—Reflector

6—Visible light source 7—CCD camera 8, 10—Thin film beam splitter 9—Attenuator

11—Focus lens 12—Coupling device 13—High pressure water inlet

14—Water-guided laser coupling energy beam 15—DD6 alloy

Image WeChat_20231218104048.png

Figure 5 The actually constructed water-guided laser processing system


04

Comparison of the effects of water-guided laser and other treatment methods

To establish the processing advantages of water-guided laser, microsecond pulse laser, femtosecond laser, and water-guided laser were used to drill holes in DD6 alloy. The surface morphology of the obtained holes was compared. The results are presented in Figure 6.

Image WeChat_20231218104052.png

a) Microsecond laser b) Femtosecond laser c) Water guide laser

Figure 6 Surface morphology of holes produced by different laser processing methods

Figure 6a shows that there is a large heat-affected zone on the surface of the hole processed by microsecond laser, the hole edge continuity is poor, and there is obvious molten material deposition. This is because the pulse width and power of the microsecond laser are large and the material cannot be completely cooled after the pulse is completed, and the heat continues to be transferred into the material, resulting in an affected area thermally on a large scale; the ablated material cannot be effectively discharged in time, deposited on the material surface to form droplet-like molten deposits. The hole surface processed by the femtosecond laser has almost no processing damage such as heat affected zone, material melting and redeposition. This is because the pulse width time of the femtosecond laser is shorter than the heat transmission time between the arrays. femtosecond laser processing This is a rough “cold working” process, resulting in better quality holes. However, due to the Gaussian distribution of laser energy, the taper of femtosecond laser holes is difficult to control, and the roundness of processed holes is poor and the processing efficiency is low, so it is difficult to process large quantities of holes. In contrast, the water-guided laser removes the molten material in time during the processing process, thereby overcoming the problem of molten metal splashing in traditional microsecond laser processing. At the same time, the jet effectively washes the cooling treatment wall, which can greatly. improve surface quality and reduce heat affected zone. During the water-guided laser processing process, the transverse energy distribution of the coupled energy beam is uniform, which makes the material surface uniformly heated during the processing process, enabling vertical processing over a longer period of time. distance, as well as the roundness and taper of the hole are also well controlled. In addition, water-guided lasers use nanosecond lasers, which can produce high energy power, significantly improving the efficiency of hole making compared with femtosecond lasers. In summary, compared with microsecond pulse laser and femtosecond laser, water-guided laser has significant processing advantages in the field of DD6 alloy hole making.


05

Processing straight holes

A nozzle with a diameter of 60 μm was used, the jet pressure was set at 15 MPa, the scanning speed was 1 mm/s, the average power was 50 W and 40 W, respectively, and a hole with a diameter of 400 µm was made on the DD6 high-temperature alloy. The surface morphology of the pores was characterized and the results are shown in Figure 7.

Image WeChat_20231218104056.png

a) 50 W, upper surface b) 50 W, lower surface

Image WeChat_20231218104100.png

c) 40 W, upper surface d) 40 W, lower surface

Image WeChat_20231218104103.png

e) 40W, cross section

Figure 7 Morphological characteristics of holes treated under different average powers

The processing results show that there is almost no slag splashing on the hole surface obtained by processing DD6 under different average powers, the hole entrance edge is sharp, the roundness is high, and the affected area thermally is extremely small. However, comparing the morphology of the inlet and outlet obtained at different power levels, it is found that there is a small amount of molten metal deposition on the surface of the hole processed under a power of 50 W, and that there is a small amount of scales and material. overhaul near the exit; while the hole processed under 40W average power has a small amount of molten metal deposition, the surface roundness of the hole exit and entrance is higher, there is no layer of recast nor heat affected zone, and there is only a small amount. quantity of material deposited on the entry surface. Analyzing the reasons for this phenomenon, it is believed that under the same conditions of operating frequency and pulse width, higher average power corresponds to higher single pulse energy and peak power, and the rate erosion of the material is higher. The water jet formed by the water pressure of 15 MPa is not enough to completely cool and flush the processing area under these conditions, which prevents part of the molten material from being discharged in time, forming a small amount of deposits on the surface of the hole, and causing the formation of a recast layer. When the average power is reduced to 40 W, the cooling and scrubbing effects of the jet on the treatment area are more sufficient in the pulse space. Material deposition on the hole surface is significantly reduced. The recast layer is almost invisible on the surface. bottom of the hole, and the roundness of the hole inlet and outlet is significantly improved.

The hole treated with a power of 40 W was cut vertically from the middle, and the obtained half-hole morphology is shown in Figure 7e. It can be seen that the hole wall is relatively smooth, has good continuity, and has almost no recast layers or heat-affected zones. In addition, the diameter difference between the hole entrance and exit is not obvious, which proves that the hole obtained by water-guided laser processing has a smaller taper than other laser processing methods. This difference is mainly due to the fact that most traditional laser energy has a Gaussian distribution. Once the laser is focused, the energy quickly diverges and processing capacity is lost. The guided laser has a uniform distribution of energy density in the cross section of the jet within the working distance, and the processing depth of field is larger. The taper of the resulting hole is smaller.


06

Treatment of oblique holes

Most motor blades have a curved surface structure, and the tilt angles in different positions are very different. It is often necessary to process oblique holes on the blades. In order to ensure the integrity of the inclined hole, it is necessary that the exit and entrance beveled edges of the produced inclined hole are smooth and free of defects. Use a water-guided laser to make a 45° inclined hole on 2.6mm thick DD6 alloy. The diameter of the target hole is 400 µm. A concentric circular tool path is used. The selected parameters are: average laser power 40 W, scanning speed 1 mm/. s, water pressure 15MPa. Characterize the top and bottom surfaces and cross-sectional morphology of the treated hole, as shown in Figure 8.

Image WeChat_20231218104107.png

a) Upper surface b) Lower surface

Image WeChat_20231218104110.png

c) Section

Figure 8 Morphology of oblique holes obtained by water-guided laser treatment

For samples of the same thickness, the processing distance of oblique holes is longer than that of straight holes, and the processing is more difficult. However, observing the characterization results, it was found that the roundness of the inclined hole entrance was very good, and there was no molten material on the surface, which was consistent with the surface untreated. The edge of the hole is not missing or broken, but there is some damage at the end where the angle between the hole axis and the coating surface is acute. This is because the material at the end of the acute angle is thinner and is easily removed. by high speed water jets, causing minor defects. The end of the hole where the angle between the hole axis and the surface is an obtuse angle is sharp and no collapse occurs. The morphology of the exit surface is consistent with that of the entrance. However, as drainage at the bottom of the hole is more difficult and scrubbing and cooling performance is poorer, the surface quality obtained is reduced accordingly. The cross-section quality of the inclined hole is basically the same as that of the straight hole, the hole wall is smooth and continuous, and there is almost no recast layer and heat-affected zone, which meets the production requirements of air film. turbine blade hole. Tests have shown that the water-guided laser can produce high-quality straight holes with a diameter of 400 μm and 45° inclined holes in 2.6 mm thick DD6 nickel-based superalloy, which which has significant advantages in the field of air film hole production. in the turbine blades.


07

Conclusion

A water-guided laser was used to perform hole processing on a 2.6 mm thick DD6 nickel-based high-temperature alloy. The treatment quality and efficiency were compared with those of a microsecond pulse laser and a femtosecond laser, as well as the treatment advantages of the water-guided laser. were established. The 400μm straight holes and 45° inclined holes processed by water-guided laser processing are of excellent quality, with good hole surface roundness and almost no defects caused by material deposition, areas affected by heat and chipping. They meet hole making needs. industrial production and are ideal for turbines. Producing air film holes in the blades provides a better processing method.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: The impact of machining allowances on machining precision!

Great Light CNC Machining Services 12/01/2025 11:11

With the continuous improvement of quality requirements for mechanically processed products, people have invested a lot of time and energy in exploring methods and measures to improve product quality, but they have ignored the impact of machining allowance on product quality during the machining process. As long as there is a margin during processing, it will not have much impact on the quality of the product. In the actual processing of mechanical products, it is found that the size of the machining allowance of parts directly affects the quality of the product.

If the machining allowance is too small, it will be difficult to eliminate the residual shape errors and surface defects in the previous process; if the allowance is too large, it will not only increase the machining workload, but also increase material consumption; , tools and energy. What is more serious is that the heat generated by removing a large amount of machining allowance during processing will deform the parts, increase the processing difficulty of the parts, and affect the quality of the product. strictly control the machining allowance of the parts.

1 The concept of machining allowance

Machining allowance refers to the thickness of the metal layer that is removed from the machined surface during the machining process. The machining allowance can be divided into process machining allowance and total machining allowance. Process machining allowance refers to the thickness of the metal layer removed from a certain surface during a process. It depends on the difference between the dimensions of the process before and after adjacent processes. Total machining allowance refers to the total thickness of the metal layer removed from a certain surface during the entire processing of the part from blank to finished product, that is, the difference between the size of the blank and the size of the part on the same surface on the part. The total machining allowance is equal to the sum of the machining allowances for each process.

Since there are inevitable errors in the blank manufacturing and dimensions of each process, the total machining allowance and the process machining allowance are variable values, and there are minimum machining allowances and maximum machining allowances. The machining allowance and tolerance are shown in Figure 1. In the figure, the minimum machining allowance is the difference between the minimum process size of the previous process and the maximum process size of this process. The maximum machining allowance refers to the difference between the maximum size of the previous process and the minimum size of the process; size of this process. The variation range of the machining allowance of the process (the difference between the maximum machining volume and the minimum machining allowance) is equal to the sum of the dimensional tolerances of the previous process and this process. The process dimension tolerance zone is usually specified in the part entry direction. For shaft parts, the base size is the maximum process size, while for holes it is the minimum process size.


2 Analysis of the influence of machining allowance on machining precision

2.1 The impact of excessive machining allowance on machining precision

Parts must generate cutting heat during machining. Part of this cutting heat is carried away by the iron shavings and cutting fluid, part is transferred to the tool, and part is transferred to the workpiece, causing the workpiece temperature to increase. The temperature has a great relationship with the machining allowance. If the machining allowance is large, the roughing time will inevitably become longer, and the cutting quantity will also increase appropriately, which will cause the cutting heat to increase and the workpiece temperature to increase. The biggest damage caused by increasing part temperature is the deformation of parts, especially materials sensitive to temperature changes (such as stainless steel), and this thermal deformation propagates throughout the processing process , making processing more difficult and product quality affected. . Influence.

For example, when processing thin shaft parts such as screw rods, due to the one-clamp, one-top processing method, the lengthwise degree of freedom is limited at this time , if the room temperature is too high. , thermal expansion will occur. When the lengthwise extension is blocked, the workpiece will inevitably bend and deform under the influence of stress, causing great problems in subsequent processing. The bending deformation diagram of the workpiece after heating is shown in Figure 2. If the processing continues at this time, the protruding part will be processed to the finished product. After cooling to normal temperature, the parts will undergo reverse deformation under the action of stress, causing shape and position errors and affecting quality. The bending deformation diagram of the workpiece after normal temperature is shown in Figure 3. After expansion in the diameter direction, the expanded part will be removed, and cylindrical and dimensional errors will occur after the workpiece is cooled. When grinding precision screws, thermal deformation of the workpiece will also cause pitch errors.

Image WeChat_20231219100512.png

2.2 The impact of too small a machining allowance on machining precision

The machining allowance of the parts must not be too large or too small. If the machining allowance is too small, the residual geometric tolerances and surface defects from the previous process cannot be eliminated, thereby affecting product quality. In order to ensure the processing quality of parts, the minimum machining allowance left in each process must be able to meet the basic requirements of the minimum machining allowance of the previous process. The schematic diagram of the components of the minimum machining allowance for the inner hole of a certain workpiece is shown in Figure 4. Figure 4a) shows the workpieces with inner holes. If the O1-O1 axis deviates from the OO reference axis when the hole is processed in the previous process, there will be a position error n and the inner hole will have a cylindrical error p (such as taper, ellipse , etc.) and surface roughness error h (as shown in Figure 4b) ), then in order to eliminate the geometric tolerance before boring, the minimum machining allowance on one side of the process reaming must include the values ​​of the above errors and defects. Considering that there is inevitably an installation error in the workpiece when reaming in this process, that is, the error e between the original hole axis OO and the axis of O’-O’ rotation after installing the part (as shown in Figure 4c). , and the bore in this process The dimensional tolerance T of the hole, therefore the minimum machining allowance z for this process can be expressed by the following formula:

z≥T/2+h+p+n+e (margin on one side)

Image WeChat_20231219100515.png

Figure 4 Illustration of the components of the minimum machining allowance

For different parts and different processes, the values ​​and manifestations of the above errors are also different. They must be treated differently when determining machining allowances. For example, the thin shaft is prone to bending and deformation, and the linear error of the bus bar exceeds the diameter tolerance range. The machining allowance of the process should be enlarged appropriately for the process of using tools such as floating reamers for positioning. the processing surface itself, the installation error does not need to be considered. e, the process machining allowance can be reduced accordingly for some finishing processes which are mainly used to reduce surface roughness, the size of the process machining allowance is only related to; surface roughness h.


3 Reasonable selection of machining allowance

3.1 Principles of part machining allowances

The choice of parts processing allocation is closely related to the materials used, size, precision level and processing method of parts, and depends on the specific situation. The following principles must be respected when determining the machining allowance of parts:

(1) The minimum machining allowance should be used to shorten the processing time and reduce the processing cost of parts.

(2) Sufficient processing margin must be left, especially in the final process. The machining allowance must be able to guarantee the precision and surface roughness specified in the drawing.

(3) When determining the machining allowance, the deformation caused by heat treatment of parts must be taken into account, otherwise waste may be produced.

(4) When determining the machining allowance, the processing method and equipment, as well as possible deformations during processing, should be considered.

(5) The size of the workpieces to be processed should be taken into account when determining the machining allowance. The larger the part, the greater the machining allowance. Because as the part size increases, the possibility of deformation caused by cutting forces, internal stresses, etc. increases. will also increase.

3.2 Method for determining machining allowances

3.2.1 Empirical estimation method

The empirical estimation method is commonly used in production practice. This is a method of determining machining allowance based on the craftsman’s design experience or by comparison with parts of the same type. For example, the machining allowances for the rudder stock, rudder pin, intermediate shaft and stern shaft of the vessel under construction are determined based on the craftsmen’s many years of design experience. Considering the importance of the workpiece, coupled with the influence of factors such as its large size and high stress on the forging blank, a semi-finishing allowance of 6 mm is left after rough turning of the circle exterior, a fine turning allowance of 3 mm is left after semi-finishing, and a fine turning allowance of 3 mm is left after fine turning of 1 mm. In order to avoid insufficient machining allowance and producing scrap, the machining allowance estimated by the empirical estimation method is generally too large. This method is often used for the production of unique pieces and small batches.

3.2.2 Table search correction method

The look-up table correction method is a method that is compiled into a table based on the machining allowance data accumulated in production practice and experimental research, and revised according to actual processing conditions to determine the machining allowance. This method is widely used. . The machining allowances for the finely turned outer circle and the ground outer circle of the rolling parts after rough turning are shown in Table 1 and Table 2, respectively.

3.2.3 Method of analysis and calculation

The analytical calculation method is a method for comprehensively analyzing and calculating various factors that affect the machining allowance based on test data and calculation formulas to determine the machining allowance. The machining allowance determined by this method is accurate, economical and reasonable, but it requires the accumulation of relatively complete data. It is not as simple and intuitive as the above two methods, so this method is currently rarely used.


4 Conclusion

In actual production, the production methods of many part blanks are temporarily determined. For example, the spin-cast stainless steel sleeve is made of rolled and welded steel plates; the cooler end cover, engine base and gearbox sand castings are replaced with sand castings. welded parts, wait. There are many uncertain factors in the production process of these parts, and their shape errors are difficult to predict. Therefore, the three methods for determining the machining allowance of parts presented in this article are not suitable for determining the machining allowance of these parts. They can only be used in practice. Be flexible during the production process.

Table 1 Machining allowance in mm of the outer circle of shaft parts after rough turning after rough turning

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Table 2 Machining allowance mm for cylindrical grinding of shaft parts

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Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

Image WeChat_20231220100424.png

CNC Knowledge: Difficulties and solutions in cylindrical grinding of graphite parts

Great Light CNC Machining Services 12/01/2025 09:08

1 Preface

Graphite is a black, non-metallic material[1]the density is lower, 2.25g/cm3. Due to its advantages of high temperature resistance, self-lubrication, corrosion resistance, light weight and good plasticity, it is widely used in industrial production. Graphite products generally have very high quality requirements. However, the characteristics of the graphite material itself make it prone to various problems during processing. For example, when grinding the outer circle, oversized ellipses, excessive dimensions and machined surface quality defects may appear, leading to substandard quality or even scrapping. processed products.

Through long-term accumulation of experience in processing graphite materials and reasonable analysis of the problems encountered during processing, cutting parameters, grinding methods, grinding wheel selection, clamping force and other process factors when grinding the outer circle of graphite can be optimized effectively. overcome the quality problems that arise during the processing of the outer circle of graphite parts, ensure the processing accuracy and reduce defects.

2 Problems that arise when grinding the outer circle

2.1 Clamping deformation

Due to the external dimensions and high toughness of the parts, when the parts are clamped, slight changes will occur in the shape of the tooling, which will affect the quality of the product. Tightening of parts is shown in Figure 1.

Figure 1 Tightening parts

(1) The two processing marks that affect the roundness and coaxiality of the workpiece are the inner hole and the chuck, the interference fit between the inner hole of the workpiece and the small taper chuck, and the wear of the chuck or poor contact between the tip and the central hole can cause out-of-tolerance runout. The inner hole in the previous process is processed by a lathe. There may be clamping deformation, which may make the inner hole become elliptical, thereby affecting the machining accuracy of the outer circle.

(2) Affects the size of parts Graphite material has high toughness. When the graphite parts are clamped on the chuck, due to the taper of the chuck, the workpiece will be enlarged by the chuck, resulting in deformation, resulting in the actual size. of the part to deviate small, which results in an out of tolerance.

2.2 Various defects appear on the surface of parts

During the process of grinding graphite parts, due to their soft texture[2]will be affected by factors such as grinding wheel particles and grinding methods, causing various defects on the workpiece surface: ① Polygonal defects. There are equidistant straight lines on the workpiece surface along the axis direction. ②Spiral defects. The grinding surface has a spiral mark. ③ Scratches or scratches. There are obvious engraved grinding marks on the surface, some are large, some are small, some are long and some are short.

3 solutions

3.1 Grinding wheel selection

When choosing a grinding wheel, the characteristics of the grinding wheel (abrasive, grain size, hardness, bond and structure of the grinding wheel, etc.) have an extremely important impact on the quality of the outer circle of graphite parts. If the grinding wheel is not selected correctly, the surface roughness of graphite parts will be difficult to meet the requirements. In addition, the cutting performance of the grinding wheel must be guaranteed. When processing graphite parts, choose a harder grinding wheel, whose abrasives are not easy to fall off. This can not only avoid the adverse effects of falling abrasives on the machined surface, but also ensure the sharpness of sand grains. The parts processing process is shown in Figure 2.

Image WeChat_20231220100427.png

Figure 2 Parts processing process

3.2 Grinding method

Generally, coarse and fine grinding methods are used for processing.[3]. When rough grinding, the parts will have a large amount of grinding, and the positioning cross feed method is used. Since the grinding wheel has a large contact area with the graphite parts, it is easy to generate heat during grinding, so sufficient cooling is required during rough grinding. When fine grinding, longitudinal grinding is used and transverse feed is carried out during the grinding process. The quantity of grindstone is.

Small, it can effectively guarantee the processing accuracy and workpiece size requirements.

3.3 Method of clamping parts

Generally, a tapered chuck is used to drill the outer circle. Since the graphite parts and chuck use an interference fit, the clamping force must be appropriate. Clamping of workpieces is shown in Figure 3. Generally, greater clamping force is used during rough grinding. This is because during the rough grinding process, the feed quantity is relatively large, the workpieces are pressed, and the grinding force on the workpieces is larger, so more clamping force is used. . Relative movement between workpiece and spindle can be avoided. When fine grinding, when there is no relative movement between the workpiece and the chuck, the lower the clamping force, the better to prevent the graphite workpieces from being stretched by the chuck and deformed elastically, thus affecting the size of the part. . The amount of interference during coarse grinding is generally 0.005-0.1mm, and the amount of interference during fine grinding is 0.003-0.005mm.

Image WeChat_20231220100430.png

Figure 3 Tightening parts

4 Examples of processing graphite products

4.1 Examples of parts

The material quality of the parts is M125P, which is characterized by light texture, low density and brittle material. The processing model requires that the coaxiality between the inner hole and the outer circle is 0.01 mm and the surface roughness value Ra = 0.8 μm. Processed with M1420A cylindrical grinder[4]according to RT 03 detection table to match the grinding size, calculate the gap value and fill it into RT-40 table, and use the through chuck during processing. The ground parts are shown in Figure 4.

Image WeChat_20231220100433.png

Figure 4 Parts after grinding

4.2 Analysis of actual processing

The two machining marks for coaxiality are the inner hole of the part and the outer circle of the chuck. Chuck wear or poor contact between the tip and center hole can cause out-of-tolerance runout. The inner hole of the workpiece in the previous process is processed by a lathe. There may be clamping deformation, which may make the inner hole oval, thereby affecting the processing of the outer circle.

The elastic deformation of parts and the clamping force during clamping will affect the processing accuracy and cause measurement errors. The biggest processing difficulty lies in the surface roughness of the outer circle of graphite parts. Since graphite is a non-metallic material, the mixture of particles rejected by the grinding wheel and the cutting fluid will scratch the surface of the part; tiny impurities in the circulating cutting fluid rushing into the grinding zone will also cause passivation; of the grinding wheel will cause scratches on the surface of the workpiece. Multiple veins or spiral defects will appear.

4.3 Solutions

(1) The coaxiality of the parts ensures that the chuck is measured with a lever micrometer on the deflectometer before use. It can only be used when the runout of the outer circles at both ends of the chuck relative to the center hole is less. than 0.005 mm.

(2) The size of the parts ensures that the processing of the parts is divided into two parts: coarse grinding and fine grinding. Surface roughness and deformation are not taken into account during coarse grinding, and only the amount of grinding remaining for subsequent fine grinding is guaranteed. During processing, positioning plunge grinding is adopted, the cutting amount is relatively large, and the processing is carried out several times, and the feed amount is controlled at 0.01 ~ 0.02 mm/r. Slightly increase the clamping force between the workpieces and the chuck, with an interference of about 0.005~0.01mm, which can improve work efficiency. When fine grinding, measure the size of the workpiece first. If the workpiece is distorted, appears elliptical, or has a cylindricity greater than 0.01 mm, drill holes to ensure that the clamping force should be moderate and interference between the chuck and the. the workpiece should be controlled to 0.003~0.006mm, so that the elastic deformation of clamped parts is small and the geometric tolerance is guaranteed. When grinding, the machine tool adopts the reciprocating grinding method, and the feed speed is 0.001 ~ 0.005mm/r. The cutting amount is small, the grinding amount is small, and the pressure generated during grinding is used for a short time. time, allowing for a more precise grinding size. Reciprocating cutting can not only improve the surface quality of the outer circle, but also reduce the grinding marks produced on the machined surface of the workpiece, making the surface smoother.

(3) The surface roughness of the parts is guaranteed to ensure the surface roughness of the outer circle processed, mainly through the selection and dressing of the grinding wheel. When the hardness of the workpiece is low, the abrasive grains slowly passivate, causing the abrasive grains to fall off before they become dull, so a harder grinding wheel should be selected when the hardness of the workpiece is low and the toughness is high ; chips will easily clog the grinding wheel, so a coarse-grained grinding wheel should be selected with large pores. Combined with the soft nature of graphite, it is most effective to choose a chrome corundum grinding wheel with a hardness of K or L, a ceramic bond, and a grain size of 60#.

When fine grinding, grinding wheel wear is very low. Generally, a cut of 0.05 mm is enough to restore the cutting performance of the grinding wheel. The correction speed is slower, about 150~200mm/min. Finally, light pruning is carried out to remove individual protruding micro-edges and loose grains of sand on the grinding wheel.

(4) Cutting fluid When machining graphite parts, it is necessary to ensure that the cutting fluid is clean. The machine tool must be equipped with a filtration system to prevent the mixture of particles from falling from the grinding wheel and the cut. The fluid does not scratch the workpiece surface or mix tiny impurities into the circulating cutting fluid.

(5) Fixed value measurement: After the graphite parts are processed on the machine tool, a constant temperature adjustment is required. After the parts are stable, the measurement is then calculated according to the correspondence table and the table is carried out. completed.

5Conclusion

This article introduces the problems and solutions that arise in cylindrical grinding of graphite parts, summarizes and shares the grinding processing experience and skills. When processing graphite parts, it is necessary to carry out careful process analysis based on the material’s own characteristics and model requirements, and select appropriate fixtures, grinding wheels and grinding methods to solve problems such as clamping deformation, dimensional tolerances and surface defects of parts. Thus producing high quality products.

Expert Commentary

The graphite material in this example has excellent properties such as self-lubrication and corrosion resistance, and is widely used in the field of mechanical processing. However, graphite has a soft texture and is subject to elliptical deformation, dimensional deviations and surface quality defects during cylindrical grinding. Aiming at the quality problems that occur during cylindrical grinding of graphite parts, the author conducts analysis of causes and processing examples based on the characteristics of materials and parts, and summarizes the experience and skills of cylindrical grinding. By selecting appropriate grinding wheels and grinding methods, optimizing the spindle clamping method and other process improvement measures, problems such as clamping deformation, dimensional tolerances and surface scratches are solved efficiently, thereby improving production efficiency and reducing costs. The article has reasonable structure, complete content, clear logic and strong argumentation, and has good reference and application value.

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CNC Knowledge: Some understandings of five-axis linkage horizontal turning and milling compound machining center

Great Light CNC Machining Services 12/01/2025 08:07

The five-axis linkage turning and milling machining center is the shining pearl in the crown of lathe products. It is developed based on the three-axis turning center. It can be clamped in a single turning and milling center to carry out all turning, milling, drilling, reaming, tapping and even heat, laser and other treatments. Its wide range of processes and strong capabilities have made it the current leader in composite processing. machine tools which. It is the most effective way to treat turbines, blades, marine propellers, heavy-duty generator rotors, steam turbine rotors and large diesel engine crankshafts.

After the five-axis linkage compound turning and milling machining center is clamped once, the machine tool executes multiple processes such as turning, milling and cutting according to different processing procedures, selects and replaces automatically tools and dynamically changes the spindle speed of the machine tool. , the feed speed and the relative position of the tool. The motion traces and other auxiliary functions of the workpiece are used to complete the machining of the complex spatial surface of the workpiece in sequence, resulting in higher product precision and smoother processing. However, the technology is complex and processing and manufacturing are difficult. Domestic enterprises have just entered the five-axis turning and milling center, and the market share is basically monopolized by foreign countries. Domestic users have also used a large number of imported milling lathes for processing complex parts, scientific research and manufacturing new products. According to the structure of the machine tool, five-axis linkage turning and milling centers can be divided into two categories: vertical and horizontal. This article mainly introduces some situations of five-axis horizontal linkage turning and milling centers.

1. Development process

The concept of five-axis linkage turning and milling centers originated in Europe. Austrian company WFL Milling and Turning Technology is a pioneer in the Japanese composite processing machinery industry. Currently, the machine tools are located in Germany and Switzerland. have the highest precision and most complete Overall, Germany has the highest level, Japan has the greatest production value and has the highest global market share.

China’s five-axis turning and milling center started late. The first five-axis turning and milling center was the SSCKZ63-5 five-axis turning and milling compound machining center produced by Shenyang Machine Tool (SMTCL) and German MAX MULLER. company at the Beijing Exhibition in 2001. Exhibited, the parameters of the era reached the international level in the late 1990s. The machine tool can control the X, Y, Z, B and C axes, the diameter maximum rotation of bed is Φ800mm, spindle is 2000rpm, main motor is 37kW, tool magazine has 12 tools and it is equipped. with a Siemens 840D CNC system. In recent years, large domestic machine tool companies have also launched five-axis turning and milling centers. Although the development of compound processing machines in my country started late, domestic users have also used a large number of imported turning and milling compound processing machines for complex workpiece processing, scientific research and production. manufacturing of new products.

2. Horizontal five-axis overall structure

The author believes that the current current structures of five-axis linkage horizontal turning and milling machining centers in the world are divided into three types: servo Y-axis, direct Y-axis and Y-axis. vertical.

Servo Y axis, inclined bed structure, realizes the function of Y axis through the synthesis of the tilting movement of the X axis and the tool holder, and interpolation. Representative machine models are MAZAK INTEGREX IV series, DMG GMX linear series, DOOSSAN PUMA MX and SMTCL. HTM63150iy series. At present, most companies adopt this structure, and the idea is similar to that derived from towers, focusing on tower processing. The two-axis interpolation realizes the function of the Y axis and has a compact structure, but the travel of the Y axis is limited by the structure. For example, the DMG GMX500 five-axis machining center has a rotating diameter of Φ610mm and a Y-axis stroke of 210mm; The MAZAK INTEGREX 400-IV five-axis machining center has a rotating diameter of Φ760 mm, the travel of the Y axis is 230 mm.

Direct Y axis, inclined bed structure, the tool holder moves up and down along the vertical direction of the X axis to realize the function of the Y axis, representative machine models WFL M series, SMTCL series HTM40/80. First developed by the Austrian company WFL, the design concept is based on lathes and the processing is based on turning and milling. The travel of the Y axis and the overall rigidity of the B axis tool holder are limited by the structure of the machine tool. For example, the WFL M35 turning and milling machining center has a maximum turning diameter of Φ520mm and a Y shaft stroke of 250mm.

The vertical Y axis has been developed in recent years based on the structure of horizontal machining centers and lathes. It has a flat top overall frame structure, and the tool holder moves in the vertical direction to realize the function of Y axis. Representative models include MORI SEIKI NT DCG series, MAZAK INTEGREX eH series, SMTCL HTM63150 , etc. The travel of the Y axis is large and limited by the structure of the whole machine. For example, MORI SEIKI’s NT4000 DCG turning and milling machining center has a turning diameter of Φ660 mm and a Y-axis travel of 420 mm. axis travel and a wider milling range than other machine tools with similar structures.

For the above reasons, MAZAK five-axis horizontal machines are divided into two series. The INTEGRX IV series uses a servo Y-axis structure for turning diameters below φ760mm. The INTEGRX eH series uses a vertical Y-axis structure for large turning diameters. φ610-920mm. MORI SEIKI abandoned the servo Y-axis structure, completely shifted to the vertical Y-axis structure, and proposed the concept of box-in-box structure machine tool.

3. Reference model

Austrian WFL (13501282025) Turning and Milling Technology Company, as the inventor of turning and milling technology and the largest professional manufacturer of turning and milling machine tools in the world, has installed more than 1,200 machines -five-axis tools in the world. WFL-M series turning and milling machining center sets the direction and benchmark in the research and development of high-end machine tools.

The WFL M series five-axis turning and milling unit uses a 60° gray cast iron tilt bed. The turning, boring and milling unit is gear driven and equipped with a special mechanical design and hydraulic clamping system. This series of machine tools can also carry out online measurement, deep hole drilling, inner diameter processing, gear hobbing, inner diameter spline forming, high precision machining, etc. Using the B axis, the machine tool can perform machining at any angle to the centerline. Through the five-axis linkage, parts with various complex geometric shapes can be processed efficiently, especially special materials such as stainless steel, titanium, Inconel, nickel-based alloys, etc. can be treated safely and effectively. The humanized design of the machine tool allows the operator to approach the working area without any barriers. To improve safety, WFL offers offline 3D simulation software. In order to avoid potential collision risks caused by program errors or operator errors, WFL provides real-time collision avoidance software – Collision Protection. WFL machine tools are mainly used to process aircraft landing gears, jet engine shafts, large crankshafts, camshafts, valve bodies and housings in the oil and gas industry, printing cylinders, generator shafts, turbine rotors, etc.

Machining center composed of milling and turning representative model M30 MILLTURN, maximum turning diameter Φ520 mm, maximum processing length 2000 mm, maximum turning spindle speed 4000 rpm, maximum milling spindle speed 6000/ 9000/12000 m/min optional, B axis swing angle range -110°～110°. Equipped with an intelligent tool management system that can automatically modify tool data. The machine tool is suitable for six-sided processing of complex shaft and disc parts. It combines turning, milling and drilling processes and can realize five-axis linkage processing. It can also select corresponding modules according to needs to achieve gear or deep processing. hole treatment.

4. Domestic models have made great progress

As user demands are faster, higher and stronger, machine tools must evolve in the direction of high efficiency, high precision and high reliability. This is one of the highlights of the CIMT2023 national machine tool exhibition. Five-axis composite machines. Axis linkage machine tool products have different structural forms, but each has its own characteristics. This trend will surely accelerate the development, progress and popularization of applications of domestic five-axis linkage machines. tools. However, domestic five-axis machine tools still have a long way to go in terms of intelligence and industrialization.

–Kode CNC Co., Ltd. KCX 1200 TM five-axis horizontal milling and turning machining center. Equipped with double opposing turning spindles, two lower turrets and milling spindles. The maximum processing diameter is Φ400mm and the maximum processing length (when supported by two chucks) is 1200mm; The main and auxiliary rotating spindle housings use internal cooling torque motors and are equipped with high-precision electromagnetic angle encoders + hydraulic clamping. The control system adopts Code GNC62 system, optionally equipped with BMT65 power tool turret and programmed tailstock center. The tailstock clamping force can be programmed and controlled based on the diameter and size of the workpiece.

–Machining center composed of horizontal milling and turning Qinchuan Group Baoji Machine Tool BHR800V. The maximum rotating diameter of the bed is Φ820mm, the maximum rotating spindle speed is 2700/1680rpm, the maximum milling spindle speed is 5000rpm, and the rotating range of axis B is -110°~90°. The spindle box adopts dual-motor master-slave mode, connected to a gearbox and has two speeds. The maximum spindle output torque is 3340 Nm, and the spindle clamping force is adjustable. It adopts independent storage tool store and is equipped. with a robot to achieve rapid replacement of tools and accessory heads, it can be implemented; Nowadays, it can do all kinds of high precision complex machining such as turning, milling, boring, drilling, gear milling and grinding. It is effective in processing deep holes, with a maximum processing hole depth of up to 1500mm. used in power transmission, aerospace and large marine diesel engine processing.

–Tianshui Xinghuo Machine Tool Co., Ltd. CNCX630 five-axis milling and turning compound machining center. It is jointly developed by Xinghuo and its wholly-owned French subsidiary SOMAB. The maximum rotating diameter of the bed is Φ630mm, the maximum processing length is 4000mm, and the control system is Huazhong HNC-840DI, fully closed-loop control. Equipped with hydraulic self-centering chuck, hydraulic self-centering center frame, program-controlled hydraulic tailstock, B-axis motorized tool turret and tool magazine automatic tools. Used for turning, drilling, milling, thread milling, tapping and other processing of high-strength steel parts.

–Shandong Plissen Group Co., Ltd. CH6163-5 milling and turning compound machining center. The maximum processing diameter is Φ630mm and the maximum processing length is 1000mm. The spindle unit has separately controlled hydraulic damping and hydraulic braking systems to ensure the machine tool spindle’s stable resistance to vibration during high-speed milling and low-speed gravity milling; the Y axis is a virtual axis interpolated between the X axis and the X axis; U axis at an angle of 60° to each other. Great trip, just. Good performance: The 24-bit tool magazine is installed on the rear of the sliding saddle and feeds simultaneously with the Z axis. It can install and change tools at any position of the slide travel. Z axis, which reduces traditional breakdowns. Fixed tool magazine for installing and changing tools, and greatly reduces time. The auxiliary tool change time is determined.

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CNC Knowledge: 88 Common Core Knowledge of Mold Design, An Indispensable Guide for Mold Experts

Great Light CNC Machining Services 12/01/2025 07:03

1. Commonly used plastic engineering materials and their shrinkage rates?

ABS: 0.5% (super unbreakable rubber)

PC: 0.5% (glue for bulletproof glass)

PMMa: 0.5% (plexiglass)

PE: 2% (polyethylene)

PS: 0.5% (polystyrene)

PP: 2% (100% soft rubber)

PA: 2% (nylon)

PVC: 2% (polyvinyl chloride)

POM: 2% (steel)

ABS+PC: 0.4%

PC+ABS: 0.5%

Engineering materials: ABS PC PE POM PMMA PP PPO PS PET

2. How many systems are molds divided into?

Pouring → Ejecting → Cooling → Forming → Exhausting

3. What problems should be paid attention to during the mold design process?

(1) The wall thickness should be as uniform as possible and the draft angle should be large enough.

(2) The transition part should be gradual and smooth, avoiding sharp corners.

(3) Door. The flow channel should be as wide and short as possible, and the position of the door should be adjusted according to the shrinkage and condensation process. If necessary, a cold well should be added.

(4) The mold surface should be smooth and clean, with low roughness (preferably less than 0.8).

(5) Exhaust holes and slots should be sufficient to discharge air and gases from the melt in a timely manner.

(6) Except for PET, the wall thickness should not be too thin, generally at least 1mm.

4. What are the common defects of plastic parts?

Lack of glue → Cape → Bubbles → Shrinkage → Solder marks → Black spots → Scratches → Lifting → Layering → Peeling

5. Commonly used plastic mold steels?

45#S50c718738718H

738H P20 2316 8407 H13

NAK80 NAK55 S136 S136H SKD61

6. What type of material is used for high mirror polishing?

Commonly used very hard heat treated steels, such as: SKD61, 8407, S136

7. What structures does the mold holder have?

Panel → Panel A → Panel B → Square iron → Guide post → Ejector plate → Ejector pin fixing plate → Base plate

8. What are the basic shapes of joint surfaces?

Straight surface → inclined → curved surface → vertical → curved surface

9. How to hide in UG?

ctrl+B or ctrl+shift+B

10. What are the mold processing machines and equipment?

Computer gong → Lathe → Milling machine → Grinder → Drill

11. What is 2D and what is 3D?

The English word D is the prefix for Dimension. 2D refers to the two-dimensional plan and 3D refers to the three-dimensional space, 2D generally refers to the plan view or CAD drawing, and 3D generally refers to the three-dimensional space. three-dimensional drawing.

12. What is the default accuracy of pro/e? What is the default precision of UG?

The default precision of pro/e is: 0.0012 mm, and the default precision of UG is: 0.0254 mm.

13. Among the world’s top four mold holder manufacturers?

Germany: HASCO Japan: FUTABA (Double Leaves) United States: DME China: LKM (Longji)

14. What is CAD’s default font height?

The default height of CAD characters is: 2.5 mm.

15. What is penetration and penetration?

The joining surface of the male and female molds which is parallel to the PL surface is called the penetration surface, and the joining surface of the male and female molds which is not parallel to the PL surface is called the insertion surface.

16. The relationship between bands and silk

Strips and threads are units of length. Strips are used in Taiwan, 1 strip = 0.01mm, and silk is used in Hong Kong, 1 thread = 0.01mm, so 1 strip = 1 thread.

17. What is the position of the pillow?

There are often notches on the edges of the plastic parts of the hull, which are used to install various accessories. The pillow-like part formed here is called pillow position.

18. What is a crater?

The shape of the glued part at the root of the BOOS column reflected on the mold after the volcanic eruption is called the mold crater.

19. What is finger?

Ha refers to Mo Yan, a Hong Kong idiom.

20. What is the tiger’s mouth?

The tiger’s mouth is also called: position tube, which is the part used to limit the position.

21. What is ranking?

The arrangement of the product on the mold is called grading.

22. What is the position of the glue?

The product cavity on the mold is called: glue level.

23. What is bone position?

The tendons present on the product are called: bone positions.

24. What is the position of the spine?

The BOSS column on the product is called: column position.

25. What is virtual position?

The gap on the mold is called: virtual position.

26. What is deduction?

The hook used for connection on the product is called a loop.

27. What are spark lines?

The lines left after EDM are called spark lines.

28. Which side PL?

The PL surface, also called: parting surface and pop-up surface, refers to the part where the front mold and the rear mold come into contact when the mold is closed.

29. What is a computer gong?

CNC milling machines and machining centers.

30. What is copper working?

Electric sparks generally use easy-to-process copper materials as discharge electrodes, called copper workers, also called electrodes. Copper workers are generally divided into: raw workers, raw workers, and young and young workers. good workers.

31. What is the usual position of the spark?

During the discharge process, the discharge gap between copper and steel materials is called spark position. Raw sparks are usually 10-50 and young sparks are usually 5-15.

32. What is the material level?

The thickness of plastic products is also called flesh thickness.

33. What remains of the original body?

Compared with cutting inserts, original body retention refers to a whole piece of steel as the blank to be processed, which is processed together during processing.

34. What are weld marks?

The line formed when two strands of plastic meet is called a weld mark.

35. What is a jet plane?

Once the plastic enters the mold cavity from the plastic entrance, it forms a curved and bent snake-shaped flow mark called a jet.

36. What does LKM mean?

LKM refers to Longji mold base. Commonly used mold bases include: LKM, Fudeba, Mingli, Huansheng, Changhui and Desheng.

37. What does DME mean and what does HASCO mean?

DME and LKM are both standards for standard parts, DME is American made and HASCO is European made.

38. What is undercut?

The parts of the product that cannot be directly demolded from the front and rear molds become undercuts.

39. What is infallibility?

Infallible is an idiom, which means to avoid a very simple mistake and avoid being dazed! For example: an insert has hangers of the same size on the sky and on the ground. When installing on site, it is very likely that the top and bottom sides are installed upside down, but it makes the hangers on one side only. the insert. At this time, if the upper and ground sides are installed upside down, it cannot be installed and it is impossible to install it incorrectly. This action to avoid errors caused by blurring is called foolproof.

40. What is a beer machine?

Beer machine is a local idiom, it is what we often call injection molding machine and molding machine.

41. What is silence?

The stop is the artistic line of the mouth, also known as the ugly line.

42. What is a flying model?

The flying molds are assorted molds or standard molds.

43. What is a light knife?

The action of CNC finishing is called light knife, which is to complete the machining in place from a rough cutting.

44. What is open frame?

The action of processing the position of the mold core on the mold support is called frame opening.

45. What is the word “Sha”?

Publishing involves putting the fonts on the film and then adding fonts to the fonts.

46. ​​​​​​​What is opposition?

The method of opening the mold by reversing the front and rear positions of the mold material under normal circumstances is called reverse.

47. What is fuhe?

The mold ejection method of using small inserts to reveal parts with undercuts is called Fuhe.

48. What is eating away at the front mold?

When the mold is opened, the product remains in the front mold, which is called eating the front mold.

49. What is Dingbai?

When ejecting, the required molding force is large and the ejector pin is not strong enough, resulting in the product being partially ejected. When viewed from the front of the product, there is an obvious white mark called ejection white, also known as ejection. nozzle.

50. What is pastry?

The marks left by the point of water entry on the surface of the point made during diving are called cooking marks.

51. What is a coder?

The pliers are a clamping tool, a pad with a triangular bevel and an opening slot.

52. What is overexploitation?

Overcutting refers to excessive cutting, that is, when processing the workpiece, parts that do not need to be processed are also processed.

53. What is the school cut?

The front mold pops up and opens the inner mold position.

54. What is Yata?

Tapping, tapping on the thread is called thread.

55. When should a two-tone mold be made?

When a product contains two different materials or the same material in different colors, a two-color mold is designed.

56. What is the factory’s mold design process?

Customer provides product drawings → analyzes the product → confirms the plastic variety → confirms the mold material → converts the technical drawing → multiplies and shrinks to create a mirror image → completes the assembly drawing → orders the mold base → order the mold core material → draw the mold → 3D separation → determine the flow channel / Gate method → refer to the layout diagram for the structural design → disassemble the inserts → correct the 3D → produce the project drawings “including: mold core/inserts/mold base/parts” → create a list of parts lists → reread and revise.

57. How many ways are there to eliminate mold?

Soft and forced ejaculation.

58. What are the glue supply methods?

Direct gluing → Lap gluing → Side gluing → Circular gluing → Sheet gluing → Latent type → Dot gluing → Horn type gluing → Fan gluing.

59. What are the shapes of flow channels?

There are circular flow channels → semicircular flow channels → T-shaped flow channels → regular hexagonal flow channels.

60. What are the permanent manuals and books for mold designers?

Steel books, plastic books, mold standard parts books.

61. What is the function of the spring?

Rebound when used outdoors.

62. Why does the mold need to be sketched?

Prevent product from dripping when removed from mold.

63. What is the function of screws and how to determine the corresponding length?

It mainly plays the role of tightening and fixing. The corresponding length is generally 1.5 to 2 times the diameter of the screw.

64. What is the general slope of the slider and the slope of the inclined guide column?

The slope of the slider is generally 20 degrees, and the slope of the inclined guide column is generally 18 degrees.

65. What is the function of the cold well?

The function of the cold material well is to store the small portion of plastic material at relatively low temperature that first enters the mold.

66. What is the function of the positioning ring?

The function of the positioning ring is to ensure that the correct relative position between the mold and the injection machine is maintained.

67. The relative position of coordination?

Fits are mainly divided into three categories: undercut fit, transition fit, and tight fit.

68. What is the function of inserts?

It facilitates processing, prevents carbon deposition, facilitates polishing, saves materials, facilitates exhaust, facilitates replacement, and reduces the size of the processing machine.

69. What are the hardness indicators?

Hardness indicates a material’s ability to resist hard objects pressed against its surface. Commonly used hardness indicators include Brinell hardness, Rockwell hardness and Vickers hardness.

70. Can curved surfaces be drawn? Can the group be drafted? Can the duvet be replaced?

Curved surfaces cannot be stripped, group surfaces can be stripped, and quilt groups can be replaced.

71. What is the difference between the first angle method and the third angle method?

① Any drawing method that places an object in the first quadrant and projects the view into the relationship (point of view) (observer) → (object) → (projection surface) is called the first angle method, also known as of the first quadrant method. .

②Any drawing method that places an object in the third quadrant and projects the view into the relationship (point of view) (observer) → (projection plane) → (object) is called the third angle method, also known as third quadrant method.

Note: The difference between the first angle drawing method and the third angle drawing method is the placement of the item in the view.

How to draw the first corner: put the view from left to right, the view from right to left, the view from top to bottom, and so on…

Third angle drawing method: put the view from left to left, the view from right to right, the top view to top, and so on…

72. What are the means of transporting water?

Commonly used types for water transportation include: straight type, wraparound type, water tower type, and spiral type.

73. What are the basic principles of three points of view?

The basic principles of three views are: length is aligned, height is equal, and width is equal.

74. What are the categories of injection machines?

According to appearance, they are divided into: vertical and horizontal According to the injection volume, they are divided into: ultra-small injection molding machine, small injection molding machine, medium-sized injection molding machine, large injection molding machine and super large injection molding machine; according to the clamping force of the mold, they are divided into: several tons to several thousand tons.

75. What is the relationship between clamping force and mold support force?

The clamping force of the injection molding machine should be greater than the opening force of the mold, otherwise the mold will be opened by the pressure inside the mold.

76. What are the methods of positioning male and female molds?

There are two types of positioning methods for front and rear molds: one is jig positioning and the other is mold core positioning.

77. What is the appropriate wall thickness for commonly used plastics?

The suitable wall thickness of ABS is: 1.8 ~ 3mm, the suitable wall thickness of PC is: 2 ~ 3.5mm, the suitable wall thickness of POM is: 1.5 ~ 2.5mm, the suitable wall thickness of NoryL is: 2~3.5mm. .

78. What is overflow value?

The overflow value refers to the space under which the plastic product will overflow. The overflow value of ABS is 0.04mm. The overflow value of PC is 0.06mm, the overflow value of PA is 0.015mm, the suitable wall thickness of POM is 0.04mm, the overflow value of PBT+15%GR is of 0.03mm, the overflow value of PBT+30% is 002mm, PM The overflow value of MA is 0.065mm, the overflow value of PVC is 0.07mm, the overflow value of AS is 0.05mm, the overflow value of PS is 0.05mm, the overflow value of PP is 0.03mm and the overflow value The PE is 0.02 mm.

79. How big is a standard picture frame?

Commonly used photo frames are: A0, A1, A2, A3, A4. The photo frame size of A0 is: 1189m x 841m, the photo frame size of A1 is: 841m x 594mm, the photo frame size of A2 is: 594mm x 420mm, the photo frame size A3. The frame size is: 420mm x 297mm, and the A4 photo frame size is: 297mm x 210mm.

80. Planning mold size?

Each company has different standards for planning mold sizes, but the common standards are as follows: molds of 15 to 30 series mold bases are classified as small molds, molds of 30 series mold bases are classified as small molds, to 50 are classified as medium molds and molds from 50 to 50 mold bases are classified as medium molds. The mold base mold is listed as a large mold.

81. What is elastic deformation? What is plastic deformation?

An object deforms under the action of an external force. When the external force disappears, the object can return to the deformation before deformation, called elastic deformation. When the external force disappears, the object cannot return to the deformation before deformation. is called plastic deformation.

82. What materials are commonly used for mold bases?

Mold bases are often made of Trump steel (called in Hong Kong), which is medium carbon steel and 45 steel.

83. What is the difference between CAD drawing workspace and layout space?

Model space is the space reserved for graphic entities and layout space is the space intended for drawing layouts.

84. What is the function of water transport?

The function of water transportation: controlling the temperature of the mold core.

85. What is a mold?

In industrial production, various presses and special tools mounted on the press are used to manufacture parts or products of the required shape from metallic or non-metallic materials by pressure. These special tools are collectively called molds.

86. Classification of molds?

Molds can generally be divided into plastic molds and non-plastic molds. Non-plastic molds include: casting molds, forging molds, stamping molds, die casting molds and plastic molds. According to different production processes and products, they are divided into: injection molding mold, blow molding mold, compression molding mold, transfer molding mold, extrusion molding mold, thermoforming mold and heat molding mold. rotation. According to the different types of door systems, molds can be divided into three categories: large nozzle molds, fine nozzle molds and hot runner molds.

87. What is a casting system?

The plastic flow channel from the nozzle of the injection machine to the mold cavity is called the gate system. The gate system includes: main channel, diversion channel, gate and cold well.

88. What is reverse engineering?

Reverse engineering uses a high-speed three-dimensional laser scanner to scan existing samples or models accurately and at high speed to obtain their three-dimensional contour data, then performs curve reconstruction with inverse software and performs analysis and online accuracy assessment of the reconstruction. Surface After constructing the effect and finally generating IGES or STL data, rapid prototyping or CNC machining can be achieved in one step.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

CNC Knowledge: Developing automatic lines is a strategic choice for machine tool companies

Great Light CNC Machining Services 12/01/2025 05:59

Due to the instability and uncertainty of today’s economy, machine tool companies are facing enormous transformation pressure. They must move from low-cost competition to differentiated competition and gradually move from the status of machine tool manufacturer to that of industrial service provider. promote intelligent products to promote enterprise transformation. Industry 4.0 will completely change the way products are made and disrupt our traditional understanding of manufacturing. Although the current development of automatic lines is a transition product of Industry 3.0, Industry 4.0 for intelligent manufacturing is a long-term systematic process, although it cannot be. achieved overnight. But it is a new productive force for machine tool enterprises to serve customers, participate in market competition, continue operations and achieve high-quality development.

1. Development trend of automatic lines

1. The manufacturing industry is embarking on an intelligent transformation. Under the rise of Industry 4.0, the Internet and cloud computing, digital technology has penetrated all aspects of the manufacturing industry. National and local governments have vigorously supported smart manufacturing. and the integration of computerization and computerization projects. More and more large and medium-sized enterprises have embarked on the smart construction journey at the same time, with the aging population, increasing labor costs, recruitment difficulties and huge pressure from lack of staff; Professional technicians and increasing personalized needs of customers require manufacturing enterprises to transform and upgrade and promote intelligent construction. Over the past ten years, nearly 2,000 digital workshops and smart factories have been built to guide the development of the industry. Intelligence has become the only path to development of the manufacturing industry.

2. Automation has become a new trend in the development of machine tools. With the progress of times, the manufacturing industry has entered the era of meager profits; the pursuit of efficiency and effectiveness is increasingly the perennial theme of manufacturing companies. companies are focusing on technological transformation in automation and intelligence. In the past, automated production lines have become indispensable for users in technological transformation and investment upgrading before unmanned chemical factories and intelligent manufacturing technologies are fully mature. Improving customer demand has driven the machine tool industry to accelerate its transformation. The demand for single-process machine tools has gradually decreased, while the demand for flexible, multi-process manufacturing has gradually increased. and automation have become new trends in the development of the machine tool industry.

3. It has become a consensus among global machine tool manufacturing enterprises that industrial enterprises vigorously develop automatic online intelligent manufacturing. In the new industrial era, automatic lines can meet customers’ needs for rapid production changeovers, large batches of parts and short processing cycles. , reducing labor costs, improving production efficiency and improving product quality, etc., becoming the ideal choice for more and more factories;

International machine tools Mazak, DMG MORI, Okuma, EMAG, Chiron and other companies have generally launched automatic line products, demonstrating the digital path to intelligent production in the era of Industry 4.0. Domestic companies have also begun to explore it, including Haitian Precision, Heidemann, Dalian, Baoji, etc. Different types of flexible manufacturing units and automatic production lines have been launched to improve product quality and application levels. For details, see “Automatic lines are the best route to developing mid-to-high-end CNC machine tools”. “

Imported machine tool consultation: 15910974236

2. Basic situation of automatic lines. At present, automatic line products mainly include single-machine automatic lines and multi-machine automatic lines, which are equipped with truss manipulators (two-axis/three-axis), robots (six-axis /three-axis). seven axes), multi-pallet flexible lines (single machine/line), etc. Automatic lines are used to process parts in various industries such as bearings, automotive, petroleum, military and ships. Although each product in the automatic line has its own differences, it can generally be divided into four parts.

–The host equipment part is a single machine (special machine tool)/multi-machine CNC machine tool host, functional components and its operating system;

–The automation unit part mainly includes loading and unloading robots/hands, farms, logistics warehousing, online testing and supporting tools, etc. ;

–Supporting piece of equipment, including cutting tools, accessories, fixtures, hydraulic stations, cooling units, chip removal stations, etc. ;

–Part of the power system, mainly power system, data collection, real-time monitoring, etc., to realize the interconnection and intelligent manufacturing of the whole range of equipment.


3. Pressure to develop automatic lines

1. Significant occupation of capital. The R&D, manufacturing and acceptance cycle of automatic line series products is long, large investments are slow to be repaid, and the conditions for customers to repay the full amount are also relatively strict, requiring large quantity of capital. Take the 361 payment method currently commonly used in the machine tool industry as an example. After the user pays 30% of the payment in advance, the company pre-invests funds to arrange production and can only receive 60% of the payment until the payment is made. the goods are shipped and cannot be collected until final acceptance (or expiration of the warranty period). The general cycle from signing the contract to delivering the automatic line products is 3-6 months, and it takes more than 1 year from final acceptance. until the warranty period expires.

2. The technology is complex and highly integrated. Automatic line products have customer, process requirement and machine. The threshold for machine tool technology is not only difficult to develop and manufacture core machines, but also core machines. Tooling companies must also have the ability to integrate upstream and downstream resources to provide customers with turnkey projects; functional components, tools, systems, etc. Automatic line products rely on outsourcing and automation. units, support equipment and electrical systems depend on outsourcing. Taking crankshaft processing as an example, companies need to have efficient, full-sequence manufacturing capabilities and a complete set of solutions for main journals, connecting rod journals and end faces, from machining coarse raw materials, finish machining, hole system. from machining to weight removal and balancing.

3. It is necessary to fully understand the complexity of the client’s process. The automatic line products are all customized products. They cannot function without user trust. Customers generally have high requirements for processing accuracy, product consistency and cycle time. For example, the processing cycle of friction welding electrode pillars is 15 seconds, multiplied by the machining of car pistons The cycle time is 60 seconds; most users require a Cp ≥ 1.67, which equates to a defective product rate of less than 6‰. This not only tests the overall organizational capabilities of manufacturing, but also requires the support of stable and efficient products. tool fixing systems. Provide customers with a complete set of solutions.

4. Extremely high quality requirements for employees The R&D, manufacturing and sales of automatic line products require extremely high professional quality from employees, who must not only have a solid technical foundation, but also be innovative and looking to the future. The product characteristics of the automatic line determine that the required middle and senior technical personnel and senior technicians need long-term training and self-learning. The integrated design, installation and debugging of automatic line products requires good mechanical and electrical designers, as well as senior technicians in installation, debugging, service and cutting.


4. Advantages of automatic line development Although automatic lines have problems such as large investment, slow payment and difficulties in R&D and manufacturing, its market has relatively low competition, premium rates on high revenues, strong profitability and stable market expectations; has core technology and serves the national strategy, and the development of mid-to-high-end CNC machine tools is the best way to solve the problem of “stuck neck”. It is also a “compulsory course” and a source of motivation for sustainable development. hospitality companies.

1. Policies to support intelligent manufacturing The Party Central Committee and the State Council attach great importance to the development of intelligent manufacturing. The government has issued a series of policy documents to support intelligent enterprise construction, such as the “14th Five-Year”. Plan for the Development of Intelligent Manufacturing” and “Opinions on the Recommendation of Intelligent Manufacturing Demonstration Pilot Projects” and various guides, etc.; among them, the “14th Five-Year Plan for the Development of Intelligent Manufacturing” The plan proposes clearly a “two-step approach” and strives to achieve digitalization and networking for most manufacturing companies larger than specified by 2025, with key companies in key sectors initially applying the intelligence by 2035, digitalization and networking will be fully popularized in the manufacturing sector; enterprises above the designated size, key enterprises in key sectors have become fundamentally intelligent The state provides financial support for projects. smart manufacturing projects and demonstration pilot projects, with grants ranging from 10 to 25% of the total investment. In addition, local governments provide subsidies in the same proportion.

2. Create profits with core technology. The automatic line pursues the technical core of “quality, efficiency and advantage” through the method of “strengthening the fortress and fighting stupid battles”, the company can overcome technical blocking points one by one; especially thanks to high efficiency cutting and automatic line electricity. Core technologies for intelligent manufacturing such as control and interconnection of the whole line, at the same time we will carry out technical research on cutting tools, accessories, systems and other technologies; for parts processed by automatic lines, which can focus on breakthroughs in high-speed processing, chip separation, improving surface quality and improving precision and consistency and other process technologies. By providing customers with comprehensive solutions, businesses can generate profits.

3. Improve the overall strength of the company. Customers of automatic line products have high requirements for technology, delivery time and service. Through the reverse forcing mechanism, the response speed and service level of the enterprise’s products and the support of the entire industrial chain can be improved; continuous improvement of product stability and system integration, process reliability can improve the quality and quality of enterprise supporting products, such as CNC lathes, vertical machining machines, processing machines Horizontal machining and other machine tool host products.

4. It is conducive to the development of professional talents for R&D, manufacturing, installation and commissioning, sales and service. Automatic line products require extremely high professional quality from employees. They must not only have a deep technical foundation, but also be innovative and forward-looking. The required personnel requires long-term culture and practice. Mechanical and electrical designers as well as installation and commissioning technicians of special machines and automatic line series products must have a thorough understanding of machine tool performance and manufacturing processes. This is impossible without long-term practice. Through the automatic line project, a group of front-line industrial workers and leaders in R&D, manufacturing, technology, installation, debugging, cutting and other disciplines can be trained as soon as possible.

5. Improve manufacturing capabilities of enterprises. If workers want to do their jobs well, they must first sharpen their tools. To vigorously develop automatic lines, it is necessary to create specialized workshops and sections. This requires coordination by technology, production and others. departments, replanning the company’s production capacity, purchasing production equipment, inspection and testing instruments, setting up production factors such as man-machine, materials, methods and environmental testing will help to improve the company’s manufacturing capabilities. If the existing factory is used for automatic online product processing and manufacturing, the factory structure can remain unchanged, and only the factory interior, workshop floors, walls, public facilities, air, water, electricity, gas, etc. Investments in technological transformation can be significantly reduced and rapid production can be achieved. Promoting the development of an enterprise’s automatic line business involves R&D and design, production and manufacturing, marketing, after-sales service, operation management and control, talent training and others aspects. It is a complex and systematic project. companies to build new productivity and face current competition. The process of reorganizing resources and business reengineering for future development.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: Intercity EMU bogie frame processing technology

Great Light CNC Machining Services 12/01/2025 04:56

1

Preface

The bogie is one of the key systems of railway vehicles. It not only provides traction and braking force during vehicle operation, but also ensures the quality of the entire vehicle. Its reliability is particularly important. As the main structure, the frame generally adopts an H-shaped all-welded structure, which connects the primary suspension, secondary suspension, vibration damping device, traction device, braking device, electric motor and the gearbox. The frame is made of medium thickness plates welded into a box-shaped structure to ensure the strength of the connection.

Below the frame are the main suspension-related components, such as axle boxes, vertical shock absorbers, etc. ; Above the frame are the secondary suspension-related components, such as air springs, side shock absorbers, etc. In order to ensure precise installation of each component, the front and rear sides of the frame must be processed, and the surface roughness Ra of the suspension mounting surface is limited to 6.3 μm. As the speed and carrying capacity of intercity EMUs increase, the vehicle operating environment becomes more and more complex. More and more components are installed on the chassis, and the processing requirements of the chassis are also higher and higher.

2

Process analysis

Figure 1 shows the structure of a 200-kilometer intercity EMU, with a typical H-shaped structure. The main processing positions on the rear side of the frame include the swing arm positioning seat, the suspension seat of the gearbox and bracket mounting surface; The main processing positions on the front side include the pull rod seat, the engine suspension seat and the brake suspension seat, etc. .

Figure 1 The structure of a 200 kilometer intercity EMU

Before processing the frame, all processing parts have been marked and checked, and unqualified positions have been adjusted to ensure that the required parts of the frame can be processed. Here we choose the processing method for the back side first, then the front side.[1]because there is a large flat area at the position of the cap tube in the inverted mounted state, and the position is also at the edge of the largest size of the frame, which is very suitable to be used as a rough reference for the treatment . By marking and alignment, the mounting surface on the back side is processed first, and then the finished machined surface on the back side is used as a reference to position the front side, thereby achieving precise processing of the front side.

3

Tool selection and parameter determination

3.1 Bracket mounting surface treatment plan

Use a high-speed steel end mill. Rotation speed n0 = 600 rpm, rear cut quantity ap = 1 mm, outer diameter of the cutter d0 = 80 mm, number of teeth z = 6, feed per tooth af = 0.13 mm/z, depth of the milling contact arc ae = 45 mm.

3.2 Treatment plan of rotating arm positioning seat

1) Vertical roughing of the interior facade of the swivel arm positioning seat. D63 end mill is selected to use layered cutting processing method and the tool material is high speed steel. Rotation speed n0 = 900 rpm, rear cut quantity ap = 3 mm, outer diameter of the cutter d0 = 63 mm, number of teeth z = 6, feed per tooth af = 0.22 mm/z, depth of the milling contact arc ae = 3 mm.

2) Vertical finishing of the interior facade of the rotating arm positioning seat. D25 end mill is selected to use layered cutting processing method and the tool material is carbide. Rotation speed n0 = 800 rpm, rear cut quantity ap = 5 mm, outer diameter of the cutter d0 = 25 mm, number of teeth z = 4, feed per tooth af = 0.06 mm/z, depth of the milling contact arc ae = 5 mm.

3) Rough machining of φ70mm hole for swing arm positioning seat. There is interference in vertical machining at this position, so a right angle head and corn milling cutter are used to process the tool using spiral feed. The tool material is high speed steel. Rotation speed n0 = 900 rpm, rear cut quantity ap = 0.5 mm, outer diameter of the cutter d0 = 50 mm, number of teeth z = 3, feed per tooth af = 0.44 mm/z, depth of milling contact arc ae = 0.5 mm.

4) Rough bore of φ70mm hole for rotary arm positioning seat. There is interference in vertical machining at this position, so a right angle head and a rough boring tool are used, and the tool material is high speed steel. Rotation speed n0 = 800 rpm, amount of backcut ap = 100 mm (effective bore), outer diameter of the cutter d0 = 69.6 mm, number of teeth z = 2, feed per tooth af = 0, 13mm/z, depth of milling contact arc ae =60mm.

5) Precision boring arm positioning seat with φ70mm hole. There is interference in vertical machining at this position, so a right angle head and a fine boring tool are used, and the tool material is high speed steel. Rotation speed n0 = 800 rpm, amount of backcut ap = 100 mm (effective bore), outer diameter of the cutter d0 = 70.1 mm, number of teeth z = 2, feed per tooth af = 0, 10mm/z, depth of milling contact arc ae =60mm.

3.3 Gearbox suspension treatment plan

There is interference in vertical machining at this position, so a right angle head and an end mill are used to process by layer cutting, and the tool material is high speed steel. Rotation speed n0=900r/min, rear cut quantity ap=2mm, outer diameter of the cutter d0=63mm, number of teeth z=6, feed per tooth af=0.22mm/z, arc depth of milling contact ae=2mm.

4 tooling design

For general machining procedures, the commonly used positioning method is an adjustable support on the lower part and a vertical downward pressing force on the upper part. In order to correct the dimensions of the X and Y coordinates of the part, an adjustment screw is added. the side. However, because this compression method is entirely achieved by friction, it is necessary to check the friction force and cutting force during processing to verify whether the compression is reliable.

The general weft processing tools are shown in Figure 2. The cap tube under the frame is supported by an adjustment cushion with a working area of ​​220mm × 120mm, and an opening pressure plate made of U shape is used for compression above. Auxiliary support and compression are added in places where frame rigidity is lower.

Image WeChat_20231222093324.png

Figure 2 General frame processing tools

The following takes the largest mounting surface of the holder in reverse machining, which is also the position where the workpiece receives the greatest cutting force, as an example for verification. If this position can meet the compression requirements, then all other positions can meet the requirements. requirements.

4.1 Forces on the tool

Cutting force is a resultant force[2]its sources include: resistance to elastic deformation, resistance to plastic deformation and friction, etc. In order to facilitate measurement and application, the resultant force F can be decomposed into three mutually perpendicular components: the main cutting force Fz, the cutting resistance force Fy and the feed resistance force Fx, as the shown in Figure 3.

Image WeChat_20231222093328.png

Figure 3 Breakdown of cutting force

4.2 Forces exerted on the part

The total cutting forces F′ and F acting on the workpiece are equal in magnitude and opposite in direction. Due to the design requirements of machine tools and accessories, the total cutting force is generally decomposed into the following three components: feed force Ff – the component of the total cutting force in the longitudinal feed direction, force of transverse feed Fe – the total cutting force in the transverse direction Component force in the feed direction, vertical feed force Ffn – the component force of the total cutting force in the vertical feed direction.

According to experiment, Ff=(0.3~0.4)Fz, Ffn=(0.85~0.95)Fz, Fe=(0.5~0.55)Fz.

4.3 Analysis of the constraints of the part

The force exerted on the part is:Image WeChat_20231222093331.png. vertical direction:Image WeChat_20231222093335.pnghorizontal direction:Image WeChat_20231222093339.png. The friction force generated by the vertical feed force Ffn, the tool pressure force Fpressure and the gravity force of the workpiece must be greater than the resulting force of the feed force Ff and the force d transverse feed Fe. For the part to remain stable, the resulting horizontal force must be positive. The formula for calculating cutting force is

Image WeChat_20231222093343.png

In the formula KFz=(σb/0.637)0.3, treatment of carbon structural steel σb=0.637GPa.

The coefficients and indices of the cutting force formula are presented in Table 1. It can be seen that CF=78.5,

Image WeChat_20231222093347.png

From Ffn=(0.85~0.95)Fz, we can approximately obtain Ffn=0.9×478.5=430.7(N); from Ff=(0.3~0.4)Fz, we can approximately obtain F f=0.35×478.5=167.5(N); from Fe=(0.5～0.55)Fz, we can approximately obtain that Fe=0.525×478.5=251.2(N). Then the resulting force on the horizontal plane of the tool on the workpiece is F2 = (Ff2 + Fe2) 1/2 = (167.52 + 251.22) 1/2 = 301.9 (N). Gravity G = mg = (1900/4) × 10 = 4750 (N).

Since the cutting process is extremely complex and the model building and formula usage are simplified to a certain extent during the calculation process, a larger safety factor of 10 is adopted and the thrust force external force exerted by the tool on the workpiece is approximately 3019N.

Table 1 Coefficients and exponents of the cutting force formula

Image WeChat_20231222093350.png

4.4 Calculation of the pressing force of the pressure plate

Select M16 class 8.8 bolts. According to the corresponding manual, the tightening torque Mt of the bolt is 189N·m. The calculation formula is Mt=0.001KP0d. The formula for calculating the bolt pre-tightening force is as follows:

Image WeChat_20231222093354.png

In the formula, P0 is the pre-tightening force (N); Mt is the tightening torque (N·m); K is the clamping force coefficient d is the nominal diameter of the thread (mm).

Consult relevant manuals[3]It turns out that K = 0.3. Substituting Mt = 189N·m and d = 16mm into equation (2), we obtain P0 = 189/(0.001×0.3×16) = 39375 (N).

Take the bolt and tighten it in the middle position, then the pressure exerted by the pressure plate on the workpiece is F pressure = P0/2 = 19687.5 (N).

4.5 Calculation of the maximum static friction force

Due to the presence of cutting fluid, the coefficient of static friction is taken as 0.05. Then the maximum static friction force Fdown on the bottom surface of the part = μN down = 0.05 × (Ffn + G gravity + F pressure) = 0.05 × (430.7 + 4750 + 19687.5) = 1243 ,4 (N); the maximum static friction force F on the upper surface of the part = μ N = 0.05 × F pressure = 0.05 × 19687.5 = 984.4 (N).

4.6 Conclusion of the strengths analysis

The friction force experienced by the workpiece in the horizontal direction is 2227.8 N and the thrust force given by the tool to the workpiece is 3019 N. Since the thrust force on the workpiece is greater due to friction on the upper and lower surfaces of the object, the workpiece is not reliably pressed and will move during the machining process. Therefore, in the design of frame processing tooling, the method of increasing side clamping is adopted to provide excessive horizontal force, so that the frame can remain stationary during the processing process.

5Conclusion

During the actual production process of the part, the stress situation is very complicated, and quality problems may occur if you are not careful. This article analyzes the processing technology of EMU intercity structure and calculates the force during the workpiece compression tooling process to determine whether the compression force in actual processing is reliable and whether the process plan is appropriate. similar parts.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: Detailed explanation of stepper motor knowledge, no longer be afraid of not understanding stepper motors!

Great Light CNC Machining Services 12/01/2025 03:54

PART１.

01

What is a stepper motor

A stepper motor is an electromechanical device that directly converts electrical pulses into mechanical motion. By controlling the sequence, frequency and amount of electrical pulses applied to the motor coil, the direction, speed and angle of rotation of the stepper motor can be controlled. Without the use of a closed loop feedback control system with position sensing, precise control of position and speed can be achieved using a simple to control and inexpensive open loop control system consisting of a stepper motor and its corresponding driver.

02

Basic structure and working principle

Basic structure:

How it works:

Based on external control pulses and direction signals, the stepper motor driver controls the stepper motor windings to power forward or reverse in a certain timing sequence through its internal logic circuit, causing rotating the motor forward/backward or locking it.

Take a 1.8 degree two-phase stepper motor as an example: when both phase windings are energized and energized, the motor output shaft will be stationary and locked in position. The maximum torque that keeps the motor locked at rated current is the holding torque. If the current in one of the phase windings changes direction, the motor will rotate one step (1.8 degrees) in a given direction.

Similarly, if the current in another winding changes direction, the motor will rotate one step (1.8 degrees) in the opposite direction to the first. When the current flowing through the coil winding changes direction and is excited in sequence, the motor achieves continuous rotational steps in the predetermined direction with very high operating precision. For a two-phase 1.8 degree stepper motor, it takes 200 steps to rotate once.

Two-phase stepper motors are available in two winding styles: bipolar and unipolar. There is only one winding coil on each phase of the bipolar motor. When the motor runs continuously, the current must change direction and excite sequentially in the same coil. The drive circuit design requires eight electronic switches for sequential switching.

Unipolar motors have two coils of opposite polarity on each phase. When the motor continues to rotate, it only needs to alternately power and excite the two coils of the same phase. The control circuit design requires only four electronic switches. In bipolar drive mode, since the winding coil of each phase is 100% energized, the output torque of the motor in bipolar drive mode is about 40% higher than that in unipolar drive mode.

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PART2.

01

load

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02

Speed-torque curve

The speed-torque curve is an important expression of the output characteristics of the stepper motor.

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A. Working frequency point

The motor speed value at a certain point.

n=q*Hz/(360*D)

n: revolution/second

Hz: frequency value

D: subdivision value of the control circuit

q: walking angle

For example: a stepper motor with a step angle of 1.8°, in 1/2 subdivision drive mode (i.e. 0.9° per step), has a rotation speed of 1.25r/s at an operating frequency of 500Hz.

B. Self-start zone

Area where stepper motors can be started and stopped directly.

C. Continuous operation zone

In this area, the engine cannot be started or stopped directly. The engine running in this zone must first pass through the self-start zone and then accelerate to reach this working zone. Likewise, the motor cannot be braked directly in this area, otherwise it would easily cause the motor to lose synchronization. It must first decelerate to the self-start zone before braking.

D. Maximum start frequency

The maximum pulse frequency to ensure that the motor does not lose steps when the motor is idle.

E. Maximum operating frequency

Highest pulse frequency at which an excited motor can operate without losing steps under no-load conditions.

F. Starting torque/pulling torque

It reaches the maximum load torque when the stepper motor starts and starts working at a certain pulse frequency without losing steps.

G. Operating torque/pull-out torque

It meets the maximum load torque of the stepper motor which can work stably at a certain pulse frequency without losing steps.

03

Acceleration/deceleration motion control

When the motor operating frequency point is in the continuous operation area of ​​the speed-torque curve, how to shorten the acceleration or deceleration time when the motor starts or stops, so that the motor can run at optimal speed for a longer period. of time, thus improving the effective operating time of the engine is very critical.

As shown in the figure below, the dynamic torque characteristic curve of a stepper motor is a horizontal straight line when it operates at low speed; when operating at high speed, the curve drops exponentially due to the influence of inductance;

Image WeChat_20231225101205.png

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Noticed:

J represents the moment of inertia of the motor rotor when loaded.

q represents the rotation angle of each step, which refers to the step angle of the motor during the entire drive.

During deceleration operation, simply invert the above acceleration pulse frequency and calculate it.

04

Vibrations and noise

Generally speaking, when a stepper motor operates without load, resonance occurs when the operating frequency of the motor is close to or equal to the natural frequency of the motor rotor, and serious offset phenomena occur.

Several solutions for resonance:

A. Avoid vibration area: keep the motor operating frequency within the vibration range.

B. Adopt subdivided drive mode: use micro-step drive mode to subdivide the original step into multi-step operation to improve the resolution of each motor step, thereby reducing vibration. This can be achieved by adjusting the phase current ratio of the motor. Microstepping does not increase step angle accuracy, but it can make the motor run smoother and make less noise. Generally, when the motor operates in half step, the torque will be 15% lower than that in full step. When using sinusoidal current control, the torque will be reduced by 30%.

PART３.

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Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: A set of animations to help you understand common machining methods

Great Light CNC Machining Services 12/01/2025 02:53

The most amazing thing about machines is that they bring great convenience to everyday life, from cars to kitchen knives. Do you know how their parts are processed? A set of animations to help you understand common machining methods.

Turning point

Why is a factory also called a workshop? This “round” refers to turning processing. The key to turning is to rotate the workpieces, then move the linear motion tool near them to carve the surface of the workpiece.

Firstly, the workpiece is fixed on the machine tool by the chuck. Then the workpiece is driven by the motor to rotate at high speed. The rotation speed can be controlled manually according to our processing requirements. Then you can start controlling the tool to carve the surface of the workpiece, which is called “cutting”. Common turning tools are often made from high-speed steel or carbide. In recent years, ceramic tools and artificial diamond tools are also widely used in the market. Different shapes of turning tools can meet various processing requirements:

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In addition to external surfaces, the use of boring tools in turning can also be used to finish internal surfaces where the part already has holes.

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Milling

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Having talked about “turning”, what is “milling”? In fact, it still uses rotation processing, but this time it is the cutter’s turn to rotate.

There are two methods of relative movement in traditional milling processing. One is the one shown in the image above. The workpiece is fixed and rests entirely on the cutter to seat, rotate and translate automatically. below. The part rotates and moves automatically. By simply rotating, the piece can move in three directions: forward and backward, left and right, and up and down.

The milling cutter is a multi-edged tool. In each round of milling, each edge of the cutter only participates in one cut, and the rest of the time is stopped to facilitate heat dissipation. In this way, the cutting efficiency of milling cutters is higher than that of single-edged turning tools. Milling cutters of different shapes can complete the processing of various planes, walking surfaces, grooves and cavities. The amount of milling during milling consists of four factors: cutting speed, feed amount, back cutting amount (milling depth), and side cutting amount (milling width).

Several common milling processing methods

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Several common types of strawberries

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Planing

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The working principle of planing is clear at a glance. Compared with turning and milling, the production efficiency is extremely low. However, because the equipment and tool structure are simple and easy to use. it is still used to roughen the surface of parts.

Sharpening

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Grinding is the use of abrasive tools such as grinding wheels and abrasive belts to cut the surface of the workpiece. In today’s machining, grinding heads can be integrated into the machining center of CNC milling machines.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: Analysis and treatment of X-axis jitter fault of CNC gantry milling machine

Great Light CNC Machining Services 12/01/2025 01:51

PART 1

Preface

The gantry milling machine shown in Figure 1 was purchased in 2019 and is suitable for medium-sized diesel engine bodies, textile machinery, printing machinery, automobile manufacturing, shipbuilding machinery, aerospace manufacturing , machine tool manufacturing and other industries, especially for multi-station machines. , multi-process rectangular boxes It is an indispensable key equipment for the treatment of body parts. Detecting the position of the X, Y and Z feed axes of the machine tool uses metal linear grid rulers produced by well-known German companies. The spindle orientation position detection device uses toothed photoelectric encoders produced by well-known German companies, which have high precision and high standard. reliability. In terms of electrical control, the modular design of electrical devices is adopted to ensure the electrical control unit of CNC gantry series machine tools and facilitate debugging, operation and maintenance. The whole machine is equipped with the 840D sl CNC system. The machine tool is equipped with accessory milling heads, which use semi-automatic and automatic tool changing technology to replace various accessory milling heads. It can realize multi-station and multi-process processing such as milling, boring, drilling, reaming and tapping. the part after a single tightening.

Figure 1 Appearance of the gantry milling machine


PART 2

Fault phenomenon

After installing and debugging the new equipment, the X axis still had loud sounds and slight shaking. The manufacturer also made several optimization adjustments, but the effect was not ideal. As the equipment continues to operate, the jitter phenomenon becomes more and more serious, and sometimes contour error monitoring alarms appear, which seriously affects the processing accuracy of the product.


PART 3

X-axis transmission structure

The worm box is fixed in the middle of the machine bed and is connected with the drive shaft of the workbench feed box. The worm gear engages with the worm band under the workbench to move the workbench (X direction).

The worm in the worm box is a hydrostatic worm. During operation, the constant pressure oil of the hydraulic system is injected into the surface of the meshing teeth of the worm and the worm bar, forming a high-strength hydrostatic oil film of a certain thickness , so that the worm and the worm bar form a frictionless transmission. Therefore, the transmission efficiency and precision are high, there is no wear, and the service life is long.

The oil chamber is located on the worm tooth side. The hydrostatic auger adopts double pump to supply oil, that is, the double pump leads to two oil paths with equal flow rates to supply oil to the oil chambers located respectively on the left and right sides of the worm.

In addition to a static pressure oil feed pump assembly, the static pressure auger also has a static pressure auger pre-flush oil system. When the auger oil chamber and the auger band are out of the mesh area, the static pressure oil circuit. is disconnected and the pre-flushing oil is connected, so that the mesh-free oil chamber is always filled with oil, preventing air from being mixed in the oil line, so as to improve the static pressure rigidity of the worm oil film and. ensure the load-bearing strength. The hydrostatic auger adopts the form of axial oil distribution. The structure of the static pressure auger is shown in Figure 2.

Image WeChat_20231226145027.png

Figure 2 Structure of the hydrostatic screw


PART 4

Analysis of the causes of failure

Based on the analysis of the working principle of the X-axis transmission mechanism, it is believed that there are many reasons for the X-axis jitter, such as low static pressure on the workbench , low static pressure on the worm, the worm brake. is not lit and the adjustment gap of the workbench pressure plate is too small. The servo motor itself is defective, the sensing unit is defective, the servo parameter settings are incorrect, and the gap between the worm and the worm band is incorrect. , etc.

In order to avoid a large number of blind disassembly and improve maintenance efficiency, first check the static pressure of the workbench, the static pressure of the worm screw, the braking pressure of the worm screw end, the X-axis detection unit and servo control parameters. There is no anomaly. Next, disengage the X-axis servo motor and change the X-axis to semi-closed loop operation for testing. The motor operates normally without jitter. This eliminates the problem of the servo motor itself. It has been analyzed that the main influencing factors that can cause this failure are that the adjustment gap of the pressure plate of the workbench is too small or the gap between the worm and the worm band ending is inappropriate.

(1) The adjustment gap of the workbench pressure plate is too small. The workbench adopts a closed static pressure guide rail, with a total of 8 pressure plates underneath. If the pressure plate gap is too small when the machine tool is installed, it will cause insufficient floating quantity of the workbench and cause X-axis jitter failure.

(2) Improper clearance between the worm gear and the worm band. The constant pressure oil forms a static pressure oil film between the worm gear and the worm band, allowing the worm gear and the worm to achieve a frictionless transmission if there is a gap between the worm gear. and the worm band is too small, it will make the static pressure of the oil film unstable and cause jitter failure.[1]。


PART 5

Troubleshooting

5.1 Bench Pressure Plate Clearance Inspection

By consulting the relevant information on the machine tool, the gap between the worktable pressure plate and the guide rail should be controlled within 0.05mm. If the gap is too small, the static pressure float of the workbench is not enough and the machine tool will vibrate during processing. If the gap is too large, the machine tool cannot guarantee its own rigidity requirements.

Remove the protective covers on both sides of the[2]。

Inspection of the workbench pressure plate gap is shown in Figure 3.

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Figure 3 Checking the gap between the workbench pressure plates

5.2 Inspection and adjustment of clearance between worm and worm band

By adjusting the thickness of the gasket under the mounting seat of the worm box, the gap between the worm and the worm band can be adjusted. Since the worm box is located in the middle of the bed, the workbench must be moved away during adjustment to expose the worm box, then the gaskets must be removed to adjust the gap. The specific implementation steps are as follows.

1) Set the status point of PLC DB99.DBX1.1 to 1, DB99.DBX1.2 to 0, change the worm gear, modify the PLC. programs and protects its alarm function. The main purpose of turning off the static pressure of the auger is to better detect the actual gap between the auger and the auger band.

2) Prepare a dial indicator to detect the actual gap between the worm and the worm band. First move the handwheel forward and slowly for a certain distance (note that it must be slow, because the static pressure of the auger is cut off and there is no pressure oil film static between the worm and the worm band At the same time, the current of the X axis should be monitored when moving), then move 0.01mm in the opposite direction, and the gap measured. is 0.03 mm. The measured gap between the worm and the worm band is relatively small, and the normal value of the gap should be 0.06mm.[3]。

3) Remove the X-axis grid ruler read head and mounting bracket, protect them and seal them with an airtight bag.

4) Remove the X-axis hard limit switch and cable chain fixed brackets on both sides, then activate the static pressure of the worm to move the X-axis forward until Whether the auger and auger band are about to separate, shield pressure alarm for multi-head pump behind the shaft. Because when the workbench moves backward, there is a period during which static pressure cannot be established.

5) Stop the hydrostatic worm pump, install a hand hoist in the front position of the workbench, use the hand hoist to pull the workbench with light force for the last distance, and at the same time slowly rotate the worm forward. direction until the auger and auger band are completely disengaged.

6) Remove the 8 locating pins and 14 M17 hex socket fixing screws from the worm box, then place a threaded top under each end of the worm box, use the two threaded tops to lift lightly the worm box and remove the worm box. and the bed There are 4 pieces of joints between the body, and they need to be marked for easy installation later.

7) The specific value for adjusting the joint thickness can be determined according to the angle between the worm and the worm band. The end result of the calculation is that the removed joint must be ground by 0.3mm, which may increase the clearance of the worm. gear about 0.03mm.

8) The joint is processed, assembled according to the marks, drive the worm box locating pin and tighten the fixing screw. Run the worm at idle and clean the dirt off the worm with your hands.

9) Connect the worm and worm bar, turn the positive end of the toothless worm half-turn upwards, and slowly push the workbench to the negative side with a jack until ensure that the front end of the worm bar on the workbench contacts the end face. teeth of the worm, at this time, the cylinder is lightly stressed, the machine tool activates the static pressure of the worm and slowly rotates the worm to connect the worm and the screw band endless. Then move the X axis slowly and monitor whether its current is normal and whether there is any abnormal noise.

10) Install the components removed in the steps above in order according to the marks made before. At the same time, according to the above-mentioned detection method of the gap between the worm and the worm band, detect the reverse clearance. the clearance is 0.06 mm and the detection is normal. Then change the X axis to fully closed loop, enable all PLC protected alarms, and modify the cycle program to check the working status of eliminated.


PART 6

Conclusion

As an important mechanical transmission component of large-scale CNC gantry boring and milling machines, the worm transmission mechanism has high requirements for machining precision, assembly precision and control precision, at the same time as the power transmission method of the machine tool. feed axis, the worm and worm mechanism must withstand large cutting force and irregular vibration, so the failure rate is relatively high.

The troubleshooting was lengthy and was a combination of a series of mechanical, hydraulic and electronic control issues. To deal with this kind of breakdown, it is necessary to have a certain level of understanding of the mechanical part of the transmission mechanism, the hydraulic control part and PLC control system Know. After fully analyzing the fault and understanding the structure of the machine tool, detecting and adjusting the gap between the worm and the worm band can effectively eliminate the failure of machine jitter. tool.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: Use the machining program to clear the clearance error

Great Light CNC Machining Services 12/01/2025 00:49

01

Preface

The machining precision of CNC lathes is not only related to its own precision, but also closely related to the CNC machining program. Poorly written machining programs will not only cause unexpected errors, but also falsely believe that there is a problem with the accuracy of the machine tool. When repairing the machine tool, the problem cannot be found and there is no way to start. A similar case is analyzed below.

02

Description of the fault

The part shown in Figure 1 was processed with a CK6140 CNC lathe. It was found that there was no problem with the accuracy of the first part. The outer diameter and inner hole of the second piece were two threads larger than the first piece (1). wire = 10 μm, same as below). The outer diameter and inner hole of the third piece were two threads larger than the second piece. Such problems still occurred when treatment continued. The operator thought there was an accuracy problem. machine tool and maintenance required.

Figure 1 Part structure

After checking that there is no problem with the accuracy of the machine tool, the routine machining procedures for this inner hole are as follows.

N40G0X150Z100;

N50 T0202;

N60G0X25Z1;

N70G1Z-105F0.25;

N80 G0Z100;

N90 G0X150;

There is no retraction command in the X direction after processing the N70 program. The operator stated that there is no surface roughness requirement for the inner hole. Such programming can improve treatment efficiency. the machine tool. Other technicians also agreed with the operator’s point of view, so he found himself in a situation where he didn’t know what to do.

03

Failure analysis

According to the analysis of the fault phenomenon, each part has an outer diameter and an inner hole two wires larger than the previous part, and the problem may lie in the X direction. After checking, there is no screw movement problem in the X direction, and the clearance in the X direction is exactly two threads, and the clearance compensation amount is also two threads, which indicates that there is no problem with the precision of the machine. tool. When I had no choice but to change programs, I inserted the next program segment between N60 and N70.

N63G0X24;

N66G0X25;

Keep other procedures unchanged, retest and the fault is resolved, which means the problem lies in backlash compensation. The following analyzes two situations.

The trajectory of the conventional program for machining the inner hole is shown in Figure 2, and the trajectory of the modified program for machining the inner hole is shown in Figure 3. Point A in Figures 2 and 3 is the starting point of the inner hole tool, and its coordinates are X=150, Z=100; the coordinates of point B are X=25, Z=1, the coordinates of point C are X; =25, Z=-105; the coordinates of point H are X=25, Z=0; the coordinates of point G are X=24, Z=1 and F are the two ends of the ball screw in the X direction; nut.

Image WeChat_20231227093823.png

Figure 2 Trajectory of conventional interior hole machining program

As shown in Figure 2, when the tool moves from A to B, the actual gap between the X-axis ball screw and the nut is at point F. At this point, there is no no gap between the screw and the nut at point E. When the tool moves from B to C, the ball screw of the X axis does not move. When the tool moves to point H and starts cutting, the tool is subjected to a compressive force from the workpiece in the negative direction of the X axis. Under the action of this force, the ball screw nut moves slightly toward the negative end of the X axis when F When all the spaces at the end are transferred to the E end, the micro- movement stops. The CNC system cannot know this process, so point C is equivalent to a ball screw reverse set shifted in the negative direction of the female is well adjusted 2, and after running N80 GOZ100, it will not affect the change direction X clearance of ball screws. Run N90 G0X150, the X axis is reversed, and the CNC system automatically performs ball screw backlash compensation. Due to the action of external force, the reverse clearance of the X axis has been transferred from end F to end E, and there is no gap when point A is shifted by a point A instead of the original position of point A. reverse clearance amount in the positive direction of the X axis. In this way, each time the inner hole turning tool cycles, as long as the extrusion force in the negative direction of the X axis is compensated by an amount of play in the positive direction of. the X axis, causing the above failure.

In Figure 3, program instructions N63 and N66 are added. After the N66 program is executed, the actual gap between the ball screw and the nut is in F, and there is no gap in E at this time. From H to C, although the tool is subjected to the negative extrusion force of the workpiece towards the X axis, there is no gap at E and the ball screw is positioned by the servo motor, so there will be no errors in the Direction X, and the problems mentioned above will not occur in the event of a continuous processing fault.

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Figure 3 Program path for machining the inner hole after modification

04

Conclusion

The above examples illustrate that eliminating backlash is one of the important ways to ensure machining accuracy. The system parameter compensation method does not affect the writing of processing programs. Although the system parameter compensation method is easy to use, simple and clear, it has great limitations. Using machining programs to eliminate backlash is suitable for open and semi-closed loop systems, especially systems without compensation. It has a great practical effect. However, this method of programming requires a high degree of process knowledge and understanding of the structure of the machine tool from the programmer.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

What should you pay attention to when using CNC universal inclined rail gear shaping machine?

Great Light CNC Machining Services 12/01/2025 00:25

　　CNC universal inclined rail gear shaping machineThis is advanced gear processing equipment. Its working principle is based on the gear shaping method, that is, using a gear shaping cutter as a tool to cut the workpiece along a predetermined path. During the machining process, the gear shaping cutter makes reciprocating cutting movements up and down, and at the same time makes relative rolling and oblique feeding movements with the workpiece. The relative position and speed of the tool and workpiece are controlled by the CNC system to achieve high precision gear processing.
　　CNC universal inclined rail gear shaping machineOperation elements:
1. Preparation before operation
Equipment Inspection: Before use, you should carefully check whether the mechanical structure, electrical system and other parts of the CNC gear shaping machine are intact. If there is any defect or damage, please notify the maintenance personnel in time for repair.
Tool Inspection: Make sure the gear shaping tool is in good condition and replace it promptly if worn or otherwise damaged. At the same time, check the auxiliary tools, such as pliers, guides, etc., to ensure their normal operation.
Cleaning the working area: Keep the working area clean and tidy, and remove dust and dirt around the machine to avoid affecting the normal operation of the machine.
2. Personal protection
Wear protective equipment: Operators should wear personal protective equipment such as safety helmets, goggles, protective gloves and protective shoes to avoid injury in the event of an accident.
Operational Training: Ensure operators have the necessary knowledge and skills, receive relevant training, and understand gear shaper operating procedures and safety precautions.
3. Start and stop
Speed ​​control: When starting or stopping the CNC gear shaping machine, the speed should be slowed down to ensure the safety and stability of the operation.
It is prohibited to leave the station: operators are strictly prohibited from leaving the station during work. If they must leave the station under special circumstances, other operators must be informed in advance and power to the equipment must be turned off.
4. Adjustment and maintenance
Use tools to adjust: When adjusting the tool and clamping the workpiece, direct contact with your hands is strictly prohibited. Tools should be used to avoid injury.
Daily maintenance: After finishing work every day, the operator should clean the CNC gear shaping machine, remove impurities such as cutting oil residue and iron filings on the machine surface, and lubricate guide rails, sliders and other components.
5. Troubleshooting
Immediate power failure: In the event of a gear shaping machine failure or other emergencies, the power supply to the equipment should be cut off immediately.
Professional maintenance: If the equipment encounters abnormal conditions, timely maintenance and repair is the key to equipment maintenance. It is necessary to let professional technicians carry out repairs and strictly follow operating procedures to ensure the safety of repairs.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: What is laser cladding technology, what are its characteristics and how is it applied?

Great Light CNC Machining Services 11/01/2025 23:49

Laser coating technology involves placing selected coating materials on the surface of the coated substrate using different filling methods. After laser irradiation, they simultaneously melt with a thin layer on the substrate surface and quickly solidify to form a layer with extremely low dilution. a surface coating that is metallurgically bonded to the base material, thereby significantly improving the wear resistance, corrosion resistance, heat resistance, oxidation resistance and electrical properties of the surface of the material basic.

Laser cladding technology is a new technology with high economic advantages. It can prepare high-performance alloy surfaces on inexpensive metal substrates without affecting the properties of the substrate, thereby reducing costs and saving valuable and rare metal materials.

Lasers used in laser cladding mainly include CO2 lasers and solid-state lasers, including disk lasers, fiber lasers and diode lasers.


Process characteristics of laser cladding technology

Laser cladding can be divided into two categories according to different powder feeding processes: powder presetting method and synchronous powder feeding method. Both methods have similar effects. The synchronous powder feeding method has the advantages of easy automatic control, high laser energy absorption rate and no internal pores. In particular, cermet coating can significantly improve the crack resistance of the coating layer, thereby enabling curing. ceramic phase uniformly distributed in the coating layer.

1. Laser cladding has the following characteristics:

(1) The cooling rate is fast (up to 106 K/s), which corresponds to a rapid solidification process. It is easy to obtain fine-grained structures or produce new phases that cannot be obtained at equilibrium, such as unstable phases or amorphous states. , etc.

(2) The dilution ratio of the coating is low (generally less than 5%) and it has a strong metallurgical bond or interface diffusion bond with the substrate. By adjusting the laser process parameters, a good coating with a low dilution rate can be obtained. and the coating composition conforms to The dilution is controllable.

(3) Heat input and distortion are small, especially when using high power density and fast coating, the distortion can be reduced to the assembly tolerance of the part.

(4) There are almost no restrictions on powder selection, especially for deposition of high melting point alloys on the surface of low melting point metals.

(5) The thickness range of the coating layer is wide, and the thickness of a coating with single-pass powder feeding is 0.2-2.0mm.

(6) It can perform selective deposition, consumes less material and has an excellent performance-price ratio.

(7) Beam aiming can weld inaccessible areas.

(8) The process is easy to automate. It is very suitable for the wear and repair of common wearing parts in the petroleum field.

2. Similarities and differences between laser cladding and laser alloy

Both laser cladding and laser alloying are rapid melting processes produced by high energy density laser beams, forming alloy coatings with completely different compositions and properties on the substrate surface which are fused with the matrix. The processes of both are similar, but they are essentially different. The main differences are:

(1) During the laser cladding process, the coating material is completely melted, and the melted layer of the base material is extremely thin, so it has minimal impact on the composition of the coating layer. Laser alloy, on the other hand, adds. alloy to the surface fusion coating layer of the elements of the base material, the aim is to form a new alloy layer based on the base material.

(2) Laser cladding basically does not use the molten metal on the substrate surface as a solvent, but melts the configured alloy powder separately to make the subject alloy of the cladding layer at the same time, a fine coating layer. The substrate alloy is also melted to form a metallurgical bond. The preparation of new materials by laser cladding technology provides an important basis for the repair and refurbishment of defective parts under extreme conditions and for the direct manufacturing of metal parts. It has received great attention from the scientific community and businesses around the world.


Evaluation of laser cladding effect

To evaluate the quality of laser cladding layer, we mainly consider two aspects. The first is to macroscopically examine the shape of the coating channel, surface roughness, cracks, pores and dilution rate, etc. ; the second, under the microscope, is to examine whether a good structure is formed and whether it can provide the required performance. In addition, the types and distribution of chemical elements in the surface coating layer should also be measured, and care should be taken to analyze whether the transition layer is a metallurgical bond. If necessary, life tests should be carried out.

The research work focuses on the research and development of coating equipment, molten bath dynamics, alloy composition design, crack formation, expansion and control methods, and strength connection between the coating layer and the substrate.

The main problems facing the further application of laser cladding technology are:

(1) The main reason why laser cladding technology has not yet been fully industrialized in China is the instability of the quality of the cladding layer. During the laser cladding process, the heating and cooling rates are extremely fast, with the highest speed reaching 1012°C/s. Due to the difference in temperature gradient and thermal expansion coefficient between the coating layer and the base material, various defects may occur. in the coating layer mainly include pores, cracks, deformation and surface roughness.

(2) Automatic detection and control of the optical deposition process.

(3) The cracking susceptibility of laser cladding layer remains a difficult problem that worries domestic and foreign researchers, and also poses an obstacle to technical application and industrialization. Although crack formation and propagation have been studied, control methods are. not yet ripe.


Application of laser cladding technology

The scope and application areas of laser cladding processing technology are very wide, covering almost the entire machinery manufacturing industry.

Currently, laser coating of self-melting cobalt, nickel and iron alloy powders and ceramic phases on the surfaces of stainless steel, mold steel, malleable cast iron, of gray cast iron, copper alloy, titanium alloy, aluminum alloys and special alloys has been successfully carried out.

Iron-based alloy powder laser coating is suitable for parts that require local wear resistance and are easily deformed. Nickel-based alloy powder is suitable for components requiring local wear resistance, hot corrosion resistance and thermal fatigue resistance. Cobalt-based alloy powder is suitable for parts requiring resistance to wear, corrosion and thermal fatigue. Ceramic coatings have high high temperature resistance, good thermal stability and high chemical stability. They are suitable for parts requiring resistance to wear, corrosion, high temperature and oxidation.

Here are some typical applications of laser cladding technology:

1. Manufacturing and refurbishment of mining equipment and parts

Coal mining machinery equipment is heavily used and wears out quickly. Due to their harsh working environment, parts and components are damaged relatively quickly. Laser manufactured and remanufactured coal machine equipment parts include: three machines and one machine.

(1) Coal shear: main frame, rocker arms, gears, gear shafts, various bushings, hinged frames, oil cylinders, oil cylinder seats, guide shoes, sprockets, rail axle wheels, driving wheels, picks, etc.

(2) Tunnel boring machine: cylinder, support, shaft, various rings, picks, etc.

(3) Scraper conveyor: central chute, transition chute, gearbox, gears, gear shafts, spiral bevel gears, shaft parts, etc.

(4) Hydraulic support: hinge holes of oil cylinders, bases and supports, various bushings, etc.

2. Manufacturing and refurbishment of electrical equipment and parts

Electrical equipment is distributed in large quantities and operates continuously, and its parts have a high probability of being damaged. Steam turbines are the basic equipment for thermal energy production. Due to the special working conditions of high temperature and heat, damaged parts such as main shaft diameter, moving blades, etc. may be damaged. must be repaired regularly every year. Gas turbines often suffer damage due to operating at high temperatures of up to 1,300°C. Laser refurbishment technology is used to repair any defects and restore its performance at a cost that is only 1/10 of the price of a new unit.

Laser coating of motor rotor shaft

3. Manufacturing and refurbishment of petrochemical equipment and parts

The modern petrochemical industry essentially adopts a continuous mass production model. During the production process, machines operate for a long time in harsh environments, resulting in damage, corrosion and wear of equipment components, which often cause problems, including valves. pumps, impellers, journals, discs, bushings, bearings, etc. large rotors, and these components are very expensive, and many types of parts are involved, and most of them are complex in shape, which makes them difficult to repair, But thanks to the emergence of rotor technology laser coating, these problems are no longer a problem.

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Laser coating of hard ceramic coatings on oil drilling rods, drilling tools, etc.

4. Manufacturing and refurbishment of railway equipment and parts

Rail transport is developing rapidly with the growth of the social economy. The demand for new railway vehicles is very high, and the quantity and performance requirements for major components are also increasing. As a new resource reuse technology, remanufacturing technology can be applied to the refurbishment of vehicle parts prone to wear. Laser surface strengthening is the core technology and process method of remanufacturing, among which laser surface coating technology can be applied to repair and strengthen the surface of remanufactured parts.

5. Refurbishment of key components of equipment in other machinery industries

Remanufacturing of key parts in other machine manufacturing industries involves sectors such as metallurgy, petrochemicals, mining, chemicals, aviation, automotive, shipping and machine tools, considering the wear and tear of precision equipment, large equipment and valuable parts. These fields, erosion and corrosion areas are repaired and performance optimized using laser cladding processing technology.

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Laser coating of highly wear-resistant steel continuous casting rollers

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

Double-ended CNC grinder can be used to fix the workpiece

Double-ended CNC grinder can be used to fix the workpiece

Great Light CNC Machining Services 11/01/2025 23:22

Double-end CNC grinder is a modern precision mechanical equipment widely used in metal processing industry, especially in workpiece processing which requires high precision and efficiency.

　　CNC dual grinderThe structure is made up of:
1. Lathe bed: As the base of the whole machine, it supports other components and ensures the stability and rigidity of the grinder.
2. Grinding head: usually equipped with two grinding wheels, driven by an electric motor, which can achieve high-speed rotation. The material and shape of the grinding wheel are selected based on the characteristics of the part to be ground.
3. Workpiece fixation: used to fix the workpiece to ensure positioning accuracy during the grinding process.
4. Feeding system: controls the feeding speed and grinding depth of the workpiece, and is usually equipped with a servo motor to achieve high precision CNC.
5. Control system: CNC is carried out through a computer or PLC, which can compile processing programs and realize automated operations and multi-piece processing.
How it works:
1. Fixing the workpiece: Fix the workpiece to be ground on the grinder using pliers to ensure its stability during processing.
2. Grinding wheel rotation: The grinding head drives the grinding wheel to rotate at high speed. Because the rough surface of the grinding wheel contacts the surface of the workpiece, grinding occurs.
3. Feed movement: Under the influence of the control system, the workpiece is fed to the grinding wheel at a set speed. This process can be reciprocating, circular or spiral motion.
4. Grinding process: The grinding wheel continuously grinds the workpiece, eliminating surface irregularities and gradually reaching the required size and finish.
Application areas of double end CNC grinder:
1. Automotive industry: used for fine grinding of key components such as friction pads and brake discs to improve component performance and service life.
2. Aerospace: In the processing of engine components and structural parts, the requirements of high precision and surface finishing are ensured.
3. Mold manufacturing: surface finishing of molds, using grinders for mold production and repair to improve the precision and durability of molds.
4. Electronic industry: used to process circuit boards and electronic components to ensure high precision and reliability.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: Five-axis machining and these down-to-earth methods, see what you know?

Great Light CNC Machining Services 11/01/2025 22:48

01Side edge treatment

Compared with using the bottom edge of the tool for machining, using the side edge of the tool for machining can produce a smoother machined surface. Suitable for finish machining of complex cavity parts in the aerospace industry. Mastercam provides dedicated functions to effectively prevent overcutting of the tool and the bottom of the part cavity. It can program side edge machining based on surface or wireframe data, and can choose from several tool types, including tapered tools.

02 Efficient roughing with five-axis connection

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Mastercam’s five-axis linkage roughing adopts a fully automatic tool axis control method to avoid drastic changes in the tool axis during the roughing process.

03Use three-axis toolpaths to compile five-axis toolpaths

For some parts, we can first program a three-axis toolpath:

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This can then be converted to a five-axis toolpath in Mastercam’s multi-axis module.

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The new five-axis toolpath can automatically produce tool axes and re-optimize the original toolpath data, and includes comprehensive five-axis collision detection.

Using “three-axis five-axis” can simplify the difficulty of five-axis programming and increase the programming speed. This function supports the conversion of all three-axis toolpaths, and the generated five-axis toolpaths are fast, safe and reliable, without worrying about overcutting.

04 Automatic tool axis avoidance

When programming in five axes, we often need to consider the interference between the tool axis and the workpiece in the tool path.

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When using Mastercam for five-axis programming, we can configure automatic adjustment of the front and side tilt angles of the cutter axis and automatically tilt the cutter axis according to the tolerance specified in the areas where collisions may occur to avoid collisions after cutting; through the collision zone, the tool axis will be automatically adjusted to its original angle to avoid collision between the tool and the workpiece.

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In this way, is it easier to program five-axis toolpaths?

05Tool cutting point check

Tool cutting point control can ensure that the tool cutting point is in contact with the workpiece surface without changing any parameters to avoid cutting traps.

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Mastercam can control the feed rate between designated areas, designated connections, or segment connections, making the cut tool path through the part smoother.

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06Optimizing the distribution of tool path points

The distribution of toolpath points is optimized to control the number of toolpath nodes on each toolpath. Combined with the excellent big data processing capabilities of advanced machine tools, in Mastercam we can increase the number of toolpath nodes in the toolpath and control how the toolpath points are distributed .

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Before optimization

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After optimization

Increasing the number of cutting nodes in the tool path can make the distribution of tool path points more uniform, make the movement of the tool axis smoother during five-axis machining, and reduce vibration during machining.

This means:

Continued improvement of the quality of the finishing surface;

A stable tool load reduces tool wear;

Stable processing, the machine tool maintains high precision operation.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

CNC Knowledge: Processing accuracy does not meet standards? The forgotten “machine tool preheating”!

Great Light CNC Machining Services 11/01/2025 21:47

The factory uses precision CNC machine tools (machining centers, EDM, slow wire moving machine tools, etc.) for high precision processing. Do you have this experience: When the machine is started for processing every morning, the machining precision of the. the first piece is often not good enough; when the machine is started for processing after a long vacation. The accuracy of the first batch of parts is often very unstable, and the probability of failure is extremely high during high-precision processing, especially position accuracy.

Factories without experience in precision machining often attribute this unstable precision to equipment quality problems. Factories with experience in precision machining will place great importance on the thermal balance between ambient temperature and machine tools. They know very well that even high-precision machine tools can only achieve stable processing precision under a stable temperature environment and thermal equilibrium state. When high-precision machining is about to start after the machine is powered on, preheating the machine tool is the most basic common sense in precision machining.

01

Why do we need to preheat the machine tool?

The thermal characteristics of CNC machine tools have a significant impact on machining accuracy, accounting for almost half of the machining accuracy. The machine tool spindle, guide rails, screws and other components used in XYZ movement axis components will heat and deform due to load and friction during movement. However, the final impact on machining accuracy is the chain of thermal distortion errors. is the relative relationship between the spindle and the components of the XYZ axis of motion. Moving the workbench.

The machining accuracy of the machine tool is significantly different between the long-term shutdown operating state and the thermal equilibrium state. The reason is that the temperature of the spindle and each axis of movement of the CNC machine tool is relatively maintained at a certain fixed level. after running for a while, and as the processing time changes, the thermal accuracy of CNC machine tools tends to be stable, which shows that it is very necessary to preheat the spindle and moving parts before the treatment.

However, the process of preparing for machine tool “warm-up exercises” is ignored or unknown by many factories.

02

How to preheat the machine tool?

If the machine tool is idle for more than several days, it is recommended to preheat for more than 30 minutes before high-precision machining; if the machine tool is unused for only a few hours, it is recommended to preheat for 5-10 minutes; before high precision machining.

The preheating process aims to enable the machine tool to participate in the repeated movement of the processing axis. It is best to perform multi-axis linking, for example by moving the XYZ axis from the lower left corner to the upper right corner of the coordinate system. , and moving diagonally several times.

During execution, you can write a macro program on the machine tool to allow the machine tool to repeatedly perform the preheating action.

After the machine tool is fully warmed up, the energetic machine tool can be put into high-precision machining production. You will get stable and consistent machining accuracy.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: I understand all the complex machining drawings this time

Great Light CNC Machining Services 11/01/2025 20:47

1. Method for sizing current structures

Common hole sizing methods (blind holes, threaded holes, countersunk holes, countersunk hole sizing methods for chamfers);

❖ Blind hole

❖ Threaded hole

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❖ Counterbore

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❖ Countersunk hole

Image WeChat_20240102094402.png

❖ Chamfer

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2. Mechanical processing structure on parts

❖ Undercut groove and wheel overhang groove

When cutting workpieces, in order to facilitate tool removal and ensure that the mating surfaces of related workpieces are narrow during assembly, an undercut groove or grinding wheel overtravel groove should be pre-treated at the surface to be treated. .

The size of the undercut when turning the outer circle can generally be marked as “groove width ×; diameter” or “groove width × groove depth”. The protruding groove of the grinding wheel when grinding the outer circle or grinding the outer circle and end face.

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❖ Drilling structure

The blind hole drilled with a drill bit has a taper angle of 120° at the bottom. Drilling depth refers to the depth of the cylindrical part, excluding the conical pit. At the step borehole transition, there is also a 120° angle cone, its drawing method and sizing method.

When drilling with a drill bit, the axis of the drill bit should be as perpendicular as possible to the end face to be drilled to ensure accurate drilling and avoid breakage of the drill bit. Correct construction of three drill end faces.

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❖ Bosses and dimples

Contact surfaces between parts and other parts generally need to be treated. To reduce the processing area and ensure good contact between part surfaces, bosses and recesses are often designed on castings. Bolted bearing surface bosses or bearing surface pits in order to reduce the processing area, a groove structure is made.

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3. Structure of common areas

❖ Shaft Sleeve Parts

These parts usually include shafts, bushings and other parts. When expressing views, as long as a basic view is drawn and the appropriate cross sections and dimensions are drawn, its main shape features and local structure can be expressed. To make it easier to view the drawing during processing, the axis is usually placed horizontally for projection. It is best to choose a position where the axis is a side vertical line.

When marking the dimensions of bushing parts, its axis is often used as a radial dimension reference. From there are taken φ14, φ11 (see section AA), etc. shown in the figure. This unifies the design requirements and process reference during processing (when shaft parts are processed on a lathe, use lugs on both ends to push against the center hole of the shaft). The large end face, mating surface (shoulder), or machined surface are often used as a lengthwise reference.

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As shown in the figure, the straight shoulder with a surface roughness of Ra6.3 is selected as the main dimensional reference in the length direction, and sizes such as 13, 28, 1.5 and 26.5 are in it. pulled, then the right end of the axis; is used as an auxiliary base length direction, thus marking the total length of shaft 96.

❖ Disk cover parts

The basic shape of this type of parts is a flat disk, usually including end covers, valve covers, gears and other parts. Their main structure usually has a rotating body, usually with flanges of various shapes and uniformly distributed round holes and local structures. like the ribs. When selecting views, generally choose a section view through the plane of symmetry or axis of rotation as the primary view. At the same time, you need to add other suitable views (such as left view, right view or top view) to express the shape. and a uniform structure of the room. As shown in the figure, a left view is added to express the square flange with rounded corners and four evenly distributed through-holes.

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When marking the dimensions of the disc cover parts, the axis passing through the shaft hole is generally selected as the radial dimension data, and the important end face is often selected as the main dimension data in the direction of length.

❖ Fork parts

These parts usually include shift forks, connecting rods, brackets and other parts. Due to their variable processing positions, the working position and shape characteristics are mainly taken into account when selecting the main view. The selection of other views often requires two or more basic views, and partial views, section views and other suitable expression methods are also used to express the local structure of the part. The view selection expression diagram shown in the foot seat parts diagram is concise and clear. To express the width of the bearing and rib, the right view is not necessary, but for the T-shaped rib, it is more appropriate to use a cross. -section.

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When marking the dimensions of fork-type parts, the surface of the mounting base or the plane of symmetry of the part is generally used as the dimensional data. See figure for sizing methods.

❖ Box Parts

Generally speaking, the shape and structure of this type of parts are more complex than the previous three types of parts, and the processing positions change more. These parts generally include valve bodies, pump bodies, reducer housings and other parts. When choosing a main view, the main considerations are working location and form characteristics. When selecting other views, appropriate auxiliary views such as sections, sections, partial views and oblique views should be used according to the actual situation to clearly express the internal and external structure of the part.

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In terms of sizing, the axis required by the design, the large mounting surface, the contact surface (or processing surface), the symmetry surface (width, length) of certain main structures of the case, etc. are generally used as dimensions. reference. For those parts of the box that require cutting processing, the dimensions should be marked as much as possible to facilitate processing and inspection.

4. Surface roughness

❖ Concept of surface roughness

Microscopic geometric shape features composed of closely spaced peaks and valleys on the surface of the part are called surface roughness. This is mainly due to the tool marks left on the workpiece surface during workpiece processing and the plastic deformation of the surface metal during cutting and splitting.

The surface roughness of parts is also a technical indicator to evaluate the surface quality of parts. It has an impact on fitting properties, working precision, wear resistance, corrosion resistance, sealing, appearance, etc.

❖ Surface roughness codes, symbols and markings

GB/T 131-1993 specifies the surface roughness code and its rating method. Symbols indicating the surface roughness of parts in the drawing are shown in the table below.

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❖ Main parameters for evaluating surface roughness

The parameters for evaluating the surface roughness of the part are:

1) Arithmetic mean deviation of the contour (Ra)

Arithmetic mean of the absolute value of the contour offset in the sampling length. The value of Ra and the sampling length l are shown in the table.

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2) Maximum profile height (Rz)

In the sample length, the distance between the upper line of the contour peak and the lower line of the contour peak.

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Note: The Ra setting is preferred when using.

❖ Labeling requirements for surface roughness

1) Example of coded labeling for surface roughness

When the surface roughness height parameters Ra, Rz and Ry are marked with numerical values ​​in the code, except that the parameter code Ra may be omitted, the corresponding parameter code Rz or Ry shall be marked before the value of the setting. table for labeling examples.

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2) Marking surface roughness. Surface roughness numbers and symbols.

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❖ How to mark surface roughness symbols on drawings

1) The surface roughness code (symbol) should generally be marked on visible contour lines, dimension lines or their extension lines. The tip of the symbol should point from the outside of the material toward the surface.

2) The direction of numbers and symbols in the surface texture code shall be marked according to regulations.

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Surface Roughness Labeling Example

On the same drawing, each surface is generally marked with a single generation (symbol) and as close as possible to the dimension line concerned. When the space is small or it is inconvenient to mark, you can draw the mark. When all surfaces in a part have the same surface roughness requirements, they can be marked uniformly in the upper right corner of the drawing. When most surfaces in the part have the same surface roughness requirements, the most commonly used code (symbol) may be. At the same time, write it down in the upper right corner of the drawing and add the word “rest”. The height of all uniformly marked surface roughness symbols (symbols) and explanatory text should be 1.4 times higher than that of the drawing markings.

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The surface roughness code (symbol) of the continuous surface of the part, the surface of repeated elements (such as holes, teeth, grooves, etc.) and the discontinuous surface connected by thin solid lines is not noted only once.

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When there are different surface roughness requirements on the same surface, a thin continuous line should be used to draw the dividing line, and the corresponding surface roughness code and size should be noted.

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When the tooth shape (tooth) is not drawn on the working surface of gears, threads, etc., the surface roughness code (symbol) is displayed in the figure.

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Surface roughness codes for center hole working surface, keyway working surface, chamfers and fillets can simplify labeling.

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When parts are to be partially heat treated or partially plated (coated), the range should be drawn with thick dotted lines and the corresponding dimensions should be marked on the horizontal line on the long side of the surface roughness. symbol.

5. Standard tolerances and fundamental deviations

In order to facilitate production, realize the interchangeability of parts and meet different usage requirements, the national standard “Limits and adjustments” stipulates that the tolerance zone consists of two elements: standard tolerance and deviation basic. The standard tolerance determines the size of the tolerance box, while the base deviation determines the location of the tolerance box.

1) Standard Tolerance (IT)

The standard tolerance value is determined by the base size and tolerance class. The tolerance level is a mark that determines the accuracy of dimensions. The standard tolerance is divided into 20 levels, namely IT01, IT0, IT1,…, IT18. Dimensional accuracy decreases from IT01 to IT18. For specific values ​​of standard tolerances, see the relevant standards.

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2) Baseline Gap

Baseline deviation refers to the upper or lower deviation of the tolerance zone from the zero line within the standard limits and coordination, generally referring to the deviation close to the zero line. When the tolerance zone is above the zero line, the base deviation is a lower deviation, otherwise it is an upper deviation. There are a total of 28 fundamental deviations and the codes are expressed in Latin letters, with uppercase letters for holes and lowercase letters for trees.

This can be seen from the base gap series diagram: the hole base gap A～H and the shaft base gap k～zc are the hole base gap K～ZC and the base gap of the hole; the tree a～h are the upper gap, JS. The tolerance zones de and js are distributed symmetrically on both sides of the zero line. The upper and lower gaps of the hole and the shaft are +IT/2 and -IT/2 respectively. The basic deviation series chart only shows the position of the tolerance zone, not the size of the tolerance. Therefore, one end of the tolerance zone is an opening and the other end of the opening is defined by the standard tolerance.

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The basic deviation and the standard tolerance, according to the definition of the dimensional tolerance, have the following calculation formula: ES=EI+IT or EI=ES-IT ei=es-IT or es=ei+IT The code of tolerance zone of the hole. and the tree uses the base gap code. It consists of the tolerance zone quality code.

6. Cooperation

The relationship between the tolerance zones of holes and shafts having the same basic dimensions and combined with each other is called fit. Depending on the usage requirements, the fit between the hole and the shaft can be loose or tight, so the national standard stipulates the fit type.

1) Clearance fit: When the hole and shaft are assembled, there is a fit (including the minimum clearance equal to zero). The tolerance zone of the hole is above the tolerance zone of the shaft.

2) Transition fit: When the hole and shaft are assembled, there may be a gap or interference fit. The tolerance zone of the hole overlaps the tolerance zone of the shaft.

3) Fit with interference: There is interference (including the minimum interference equal to zero) when the hole and the shaft are assembled. The tolerance zone of the hole is less than the tolerance zone of the shaft.

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❖ In the reference system, when manufacturing matching parts, one of the parts is used as the reference part and its base deviation is certain. The system that achieves different types of adjustments with different properties by changing the base deviation of another non-standard part. This part is called the reference system. Depending on actual production needs, national standards provide for two reference systems.

1) Basic hole system: This is a system in which the tolerance area of ​​a hole with a certain basic deviation and the tolerance area of ​​a shaft with different basic deviations form various fits. See photo below left. The hole consisting of the base hole is called the reference hole, its base deviation code is H, and its lower deviation is zero.

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2) Basis shaft system: This is a system in which the tolerance area of ​​a shaft with a certain base deviation and the tolerance area of ​​a hole with different base deviations form various fits . See the image below on the right. The axis of the base axis system is called the reference axis, its base deviation code is h, and the upper deviation is zero.

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❖ Cooperation code

The fit code consists of the hole and shaft tolerance zone codes and is written as a fraction. The numerator is the tolerance zone code of the hole and the denominator is the tolerance zone code of the shaft. Any combination containing H in the numerator is a basic hole system, and any combination containing h in the denominator is a basic axis system.

For example 1: φ25H7/g6 means the base size of the fit is φ25, the clearance fit of the base hole system, the tolerance area of ​​the reference hole is H7 (the base gap is H , the tolerance level is level 7 ), and the tolerance zone of the shaft is g6 (the basic deviation is g, the tolerance level is level 6).

For example 2: φ25N7/h6 means the basic adjustment size is φ25, the transition adjustment of the basic axis, the tolerance zone of the reference axis is h6 (the basic deviation is h, the tolerance level is level 6), and the tolerance area of ​​the hole is N7 (the basic deviation is N, the tolerance level is level 7).

❖ Marking of tolerances and adjustments on plans

1) Mark tolerances and fits on the assembly drawing, using the combined marking method.

2) There are three forms of marking methods on part drawings.

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7. Geometric tolerance

After the parts are processed, there are not only dimensional errors, but also errors in geometric shape and mutual position. Even if the cylinder is of suitable size, it may be large at one end and small at the other end, or thin in the middle and thick at both ends, etc., and its cross section may not be round, which is a problem. form error. For stepped shafts, each shaft segment may have different axes after processing, which constitutes a position error. Therefore, shape tolerance refers to the allowable variation of the actual shape from the ideal shape. Position tolerance refers to the allowable variation of the actual position from the ideal position. Both are called geometric tolerances.

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Geometric tolerance chips

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❖ Shape and position tolerance codes

The national standard GB/T 1182-1996 stipulates the use of codes to mark shape and position tolerances. In actual production, when the geometric tolerance cannot be marked by a code, it is permitted to use a textual description in the technical requirements.

Geometric tolerance codes include: symbols for each geometric tolerance element, geometric tolerance frames and guidelines, geometric tolerance values ​​and other associated symbols, and reference codes, etc. The height h of the font in the frame is the same as the size number in the design.

Image WeChat_20240102094526.png

❖ Example of geometric tolerance marking

For a valve stem, text added near the geometric tolerance marked in the figure is repeated for the purpose of explanation to the reader only and need not be repeated in the drawing itself.

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Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: Method for precision machining of the spherical surface of an aircraft engine piston pump

Great Light CNC Machining Services 11/01/2025 19:46

01

Preface

As a typical friction pair of aircraft parts, spherical fit involves many parts. It is commonly found in parts such as piston shoes, ball block supports, ball block cages, etc. In the traditional process, let it be an outer spherical surface. or inner spherical surface, manual grinding is mainly used as the final finishing process, but manual grinding has disadvantages such as low efficiency and unstable quality, which have become a bottleneck in the finishing process. At the same time, the precision level of fitting the spherical surface of the parts will affect the performance indicators such as flow and pressure, and even the wear between the two will reduce the efficiency and service life of the entire pump, so the treatment method of the spherical surface is crucial. The process flow of spherical surface processing is “rough machining → heat treatment → (semi-finishing) → finishing”. This article mainly analyzes some typical spherical structures of aircraft engine piston pumps and several commonly used finishing methods. Based on several spherical surface processing methods, the processes of turning, milling, grinding and grinding are analyzed, compared and objectively evaluated.


02

turning

When using CNC lathes for processing spherical surfaces, the trajectory method is usually used, that is, the processing trajectory is determined via CNC macro programs or point programming to obtain spherical surface processing, which generally requires higher precision of the machine tool.

Spherical surfaces processed by CNC lathes are generally used for copper parts. The most widely used are ball stop parts, made of QSn7-0.2. For such parts (see Figure 1), the ball diameter tolerance is generally less than 0.015 mm and the surface area. roughness value Ra=0.4 μm, due to the subsequent surface heat treatment of the spherical surface, only pre-coating treatment is necessary.

Figure 1 Parts

Since the tin bronze material is soft, grinding and grinding are generally not used for processing, so it is processed directly to the final size through a CNC lathe.

Tool selection: The diamond blade tip has high strength, good wear resistance and chipping resistance, and excellent cutting effect, achieving stable and long-lasting processing . It is suitable for high-speed processing of aluminum alloys, brass and other non-metallic materials. ferrous metals, plastics and hard materials. Alloy turning. The tool tip adopts a 35° diamond-shaped blade with a rounded corner R (0.1 ~ 0.2) mm.

During finishing turning, the speed is generally controlled at 2000 rpm, and the feed rate is 0.015 mm/r. Usually, semi-finishing turning leaves 0.05-0.10mm machining allowance for the finishing process. the part can generally be controlled within 0.4 μm.

Although the surface roughness of these parts after processing meets the requirements, the turning lines are obvious. The surface roughness Ra value of the parts can be reduced to 0.1 µm through the subsequent finishing process.


03

Milling

Use a milling cutter to mill a spherical surface. The cutter and the workpiece rotate at the same time, the center of rotation of the cutter intersects the center of rotation of the workpiece. on the surface of the part is part of the spherical surface. Generally, end mills and ball mills are used, or using multi-axis linkage equipment such as coordinateless machining centers to mill spherical surfaces. This method requires relatively high precision for milling cutters and machine tools and is rarely used in general production shops.


04

sharpening

Spherical grinding method[1]It is widely used, including trajectory method, development method and forming method.

4.1 Trajectory correction

Path grinding (see Figure 2) is basically a linear contact between the grinding tool and the workpiece, and the contact line moves along the spherical contour to complete the grinding of the entire spherical surface.

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Figure 2 Path grinding method

1) Grinding tools: flat grinding wheel or grinding wheel with pointed or semi-circular shape.

2) Installation: The workpiece is clamped on the chuck and the top grinding method is used. The connection line is coaxial with the workpiece chuck and parallel to the axis of the grinding wheel.

3) Movement: The grinding wheel rotates at high speed after starting, and the workpiece and chuck rotate at low speed while rotating back and forth around another vertical center line of the ball. As the grinding wheel advances, a spherical surface is generated and ground.[2]。

4) Features: ① Suitable for grinding larger diameter or wider spherical surfaces. ②Grinding resistance is low. ③The accuracy of the spherical contour is determined by the positioning accuracy, the movement accuracy of the CNC machine tool, the shape accuracy of the grinding wheel and the contour tracking accuracy of the system. ④The same specification grinding wheel can grind spheres of any size, with less abrasive consumption, low investment and good economy. However, the grinding wheel is in direct contact with the workpieces, so the grinding efficiency is low and is not suitable for batch and large-scale sphere production.

4.2 Grinding generation method

Generation method Grinding (see Figure 3) of spherical surfaces is also called generation method. This method requires that the machine tool has at least one linear feed X axis and one C axis which drives the rotation of the part.

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Figure 3 Grinding generation method

1) Grinding tools: cup-shaped grinding wheel or bowl-shaped sanding disc (hereinafter collectively referred to as grinding wheel).

2) Installation: The rotation axis of the grinding wheel and the rotation axis of the workpiece form an angle α, and the intersection point is the center of the sphere to be processed.

3) Movement: The grinding wheel rotates around the axis of the grinding head spindle at high speed and the workpiece rotates around the axis at low speed in one direction. As the grinding head advances, the entire spherical surface is ground.

4) Features: High grinding efficiency, high precision and good surface roughness are the significant advantages of this grinding method. If the spherical surface specifications change, the wheel size must be changed. This method is suitable for mass production of spherical parts and is less economical. When grinding by the generation method, the diameter of the grinding wheel is related to the size of the spherical surface of the workpiece, as shown in Figure 4, L≤D sand≤(D2-d2)1/2, where D is the diameter of the spherical surface (mm) and d is the diameter of the chuck (mm), L is the thickness of the ball (mm) and D is the diameter of the cup-shaped grinding wheel (mm).

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Figure 4 Grinding scheme

During the whole grinding process, the center of the grinding wheel axis must pass through the center of the workpiece sphere. In addition, the geometric relationship between the size of the final feed position H, the inner diameter of the cup-shaped grinding wheel D and the spherical diameter D of the workpiece is H = (D2 – D sand 2) 1/2 /2. By adjusting the H value, grinding can be achieved by cutting spherical workpieces of different diameters. In the same way, the value of the feed quantity ΔH can be deduced based on the value of the ball diameter after processing the first workpiece, i.e. ΔH =[（D12－D砂2）1/2－（D2－D砂2）1/2]/2。

If the workpiece is 1/2 spherical or larger than 1/2 spherical, the workpiece and grinding wheel must be adjusted to a certain angle, as shown in Figure 5.

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a) The first situation

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b) Second case

Figure 5 Analysis of grinding conditions

Cup wheel diameter D sand =[D（D/2＋K）]1/2, when the spherical diameter of the workpiece is larger than the semicircle, K is a positive value, and when it is smaller than the semicircle, K is a negative value. Maximum inner diameter of the cup-shaped grinding wheel D sand = {D[D＋（D2－d2）1/2]/2}1/2. The corresponding angle between the axis of the grinding wheel and the spherical axis of the part is α=arcsin (D sand/D). The selection range of α is arcsin (1/2+K/D) 1/2≤α≤arcsin{.[D＋（D2－d2）1/2]/(2D)}1/2.

As can be seen from the above, when the grinding wheel grinds a spherical surface, the diameter of the grinding wheel must be within a certain range. The linear speed of the grinding wheel can grind the workpieces normally and cannot interfere with the machine tool. Pieces. Select the grinding wheel inner diameter D to the maximum, the cutting fluid can enter the inner hole of the grinding wheel from the workpiece side, which can maximize the cooling effect. In order to extend the life of the grinding wheel, it is generally necessary to make the inner hole of the grinding wheel into a bevel cut shape.

The inner hole of the grinding wheel is dressed with diamond. When grinding the outer spherical surface, the hole diameter of the grinding wheel can be selected to be slightly smaller to accurately adjust it to the required size. The grinding wheel should be softer grinding wheel (K grade, L grade), vs should be 15~20 m/s, v W should be 1~5 m/min, ap=0.02~0.04mm for coarse grinding, ap=0.002~0.005 for fine grinding mm. The processing parameters for grinding the spherical surface of the piston using the generation method are shown in Table 1.

During processing, the axis of the grinding wheel should be at the same height as the axis of the workpiece to ensure the roundness of the processed spherical surface, and the processed texture will be a cross mesh. When the surface of the workpiece has a concave-convex pattern, it indicates that the center of the wheel is higher or lower than the center of the workpiece.

Table 1 Processing parameters of piston spherical surface grinding by generation method

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The methods of internal cylindrical grinding and cylindrical grinding are similar, and the calculation methods are also the same.

4.3 Shape rectification

Shape grinding[3]That is to say, the grinding wheel is cut into an arc shape, the grinding wheel is cut into a concave spherical shape, the workpieces are convex spherical, and the spherical diameter of the grinding wheel is equal to the spherical diameter of the workpiece, as shown . in figure 6.

1) Grinding tools: shaped grinding wheels.

2) Movement: During the grinding process, the workpiece rotates in the C direction, the grinding wheel rotates at high speed, advances along the X axis, and cannot move along the Z axis.

3) Characteristics: ① The width of the grinding wheel should be greater than the thickness of the workpiece. ②The larger the grinding width of the grinding wheel, the greater the grinding resistance of the workpieces. ③The accuracy of the workpiece contour depends on the accuracy of the shape of the grinding wheel and the accuracy of the feed position of the machine tool. ④Normally, one type of part corresponds to one type of forming wheel, which is dedicated. ⑤ During the grinding process, neither the grinding wheel nor the parts can move in the Z direction. After the processing is completed, the surface roughness value of the parts will be relatively high.

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Figure 6 Schematic of form grinding

For shape grinding, the spherical diameter of the workpiece should not be too large, which is more suitable for grinding small spherical surfaces.[4]the X-axis feed accuracy of the machine tool is high, this method has high grinding efficiency and is suitable for mass production. Since form grinding generally requires the workpiece profile to be processed in a single step, the grinding wheel is usually made of CBN. The material is harder, the grinding wheel wear is low, and the surface quality after grinding is high. , the surface roughness value Ra can generally be guaranteed within 0.1 μm. The processing parameters of the spherical surface of the forming grinding piston are shown in Table 2.

Table 2 Processing parameters of spherical surface of shape grinding piston

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05

Grind

Grinding is mainly a method used for processing spherical surfaces with high precision. Generally, spherical surfaces require better contours and dimensional tolerances. General grinding methods can be divided into manual grinding and mechanical grinding. Manual grinding of spherical surfaces requires a large amount of labor, has low efficiency and unstable processing precision. The contour of the workpiece is determined by the mutual movement of the grinding ball and the workpiece. If higher accuracy requirements are required, frequent adjustments are necessary. When the surface of the grinding ball is larger than the machined surface of the workpiece, the contour of the workpiece depends on the grinding ball itself, and the grinding ball has a lower hardness than the workpiece and consumes a lot of money. Generally, one or more grinding balls are required for each part, and the cost is relatively high.

The principle of mechanical grinding is similar to grinding. The difference is that the equipment used for grinding changes from a grinding wheel to a cast iron grinding tool or a grinding head equipped with a soft grinding bar. It has the following characteristics: ① Since the grinding balls are generally made of cast iron and are manually ground, the grinding force is small, so the deformation produced during processing is small, and higher precision can be obtained. ②The surface of parts processed by grinding method has good corrosion resistance and wear resistance. ③Parts of different shapes can be processed depending on the shape of the grinding tool. ④Easy to use and does not require complex machine tools. ⑤ Can process parts of various materials, and may also have higher precision requirements.


06

Conclusion

There are many spherical structures in the piston pump parts of aviation engines, such as the outer spherical surface of the cage, the inner spherical surface of the cage, the spherical steel surface of the ball block, the surface copper spherical surface of the ball block, the inner spherical surface of the sliding pad, outer spherical surface of the piston and inner spherical surface of the bearing. This paper conducts experiments on turning, milling, grinding and grinding processes on typical workpieces to discover a suitable spherical surface processing method and take advantage of grinding processing, using mechanical grinding instead of grinding manual to improve the efficiency of spherical surface processing and shorten the service life. processing time. cycle to ensure the stability of the quality of the final product.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

High-speed CNC linear lathe: the basic equipment of modern precision manufacturing

Great Light CNC Machining Services 11/01/2025 19:18

In today’s manufacturing industry pursuing high efficiency, high precision and automation, high-speed CNC linear lathes, as a key processing equipment, are gradually becoming the choice of many mechanical processing enterprises . This type of lathe combines high-speed cutting technology with advanced CNC systems, combined with the application of linear guides, which not only significantly improves production efficiency, but also guarantees the quality of processed parts. This article will explore in depth the features, benefits and importance of high speed CNC linear lathes for modern industry.
1. Basic structure of high speed CNC linear rail lathe
A high-speed CNC linear lathe is a machine tool specially designed for efficient processing of metal materials. It is equipped with linear rolling guides (i.e. linear rails), which has the advantages of low friction coefficient and high positioning accuracy, enabling rapid movement and smooth operation. At the same time, the lathe is equipped with a high-performance CNC system, which can precisely control the position and movement trajectory of the tool through programming to complete complex cutting tasks. Moreover, high speed spindle is one of the essential components of this type of lathe. Its rotation speed can reach thousands or even tens of thousands of revolutions per minute, which is suitable for the use of various carbide cutting tools.
2. Advantages of high speed CNC linear rail lathes
Improve production efficiency: Through the use of high-speed spindles and fast-response power systems, high-speed CNC linear rail lathes can complete a large amount of processing work in a short time , significantly shortening the processing cycle.
Guaranteed Processing Accuracy: The high rigidity and low friction characteristics provided by the linear guides enable the lathe to maintain high positioning accuracy when operating at high speed, ensuring the consistency of the quality of the processed parts.
Improved flexibility: The introduction of CNC systems gives lathes great programming freedom. They can flexibly adjust processing procedures according to the design requirements of different products and adapt to multi-variety and small batch production models.
Reduce maintenance costs: Compared with traditional sliding guide rails, linear rails wear less and are easy to clean and maintain, reducing the workload and cost of daily maintenance.
Promote green manufacturing: An efficient cutting process means less energy consumption and material waste, in line with the current concept of sustainable development.
3. Future development trends
Looking to the future, high-speed CNC linear lathes will continue to develop in the direction of intelligence, integration and service. On the one hand, with the development of artificial intelligence technology and the Internet of Things, future towers will have functions such as self-diagnosis and predictive maintenance, further improving equipment reliability and experience. user, on the other hand, tower manufacturers will also pay; Greater focus on providing comprehensive solutions, including software support, training services and technical advice, help customers maximize the value of their equipment.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: 7 Types of Dynamic Seals Commonly Used in Mechanical Design and Manufacturing

Great Light CNC Machining Services 11/01/2025 18:45

The waterproof problem of mobile equipment always exists with the operation of the equipment. Today we have sorted out the various sealing forms, usage ranges and characteristics commonly used in mobile equipment, so that everyone can have a more in-depth understanding of the sealing problem.


1. Packaging seal

Seals can be divided into: according to their structural characteristics:

Soft seal

Hard packing seal

Formed seal

1. Soft packaging seal

Soft filling type: Packaging. The packing is usually woven from softer yarns and is filled into the sealing cavity through strips of square section. The stuffing box generates a pressing force to compress the packing, forcing the packing to be pressed against the sealing surface (shaft). On the outer surface and the sealing cavity), the radial force of the sealing effect is generated, thereby playing a sealing role.

Applicable occasions for soft filling:

The manufacturing material selected for the gasket determines the sealing effect of the gasket. Generally speaking, the material of manufacture of the seal is limited by the temperature, pressure and pH of the working environment, as well as the surface roughness and eccentricity of the mechanical equipment on which the seal is placed. works and linear speed, etc., will also have requirements on the selection of packaging materials.

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Graphite packaging can withstand high temperatures and pressures and is one of the most effective products for solving high temperature and high pressure sealing problems. Corrosion resistant, excellent sealing performance, stable and reliable function.

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Aramid filling is a kind of high strength organic fiber. The braided packing is impregnated with a polytetrafluoroethylene emulsion and a lubricant.

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PTFE packaging is made of pure PTFE dispersion resin. It is first made into a raw film, then twisted and woven to form the packaging. It can be widely used in valves and pumps with high cleanliness requirements and highly corrosive media in food, pharmaceutical, papermaking and chemical fiber industries.

2. Hard packing seal

There are two types of hard gaskets: split rings and split rings.

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2. Mechanical seal

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A mechanical seal always consists of two main parts: a rotating part (yellow part) and a fixed part (orange part). The two relatively movable dynamic and stationary annular surfaces become the primary sealing surface of the gasket.

Mechanical seals are also called end seals. According to relevant national standards, mechanical seals are defined as: at least one pair of end faces perpendicular to the axis of rotation which maintain fit and slide relative to each other under the cooperation of the fluid pressure, the elastic force (or magnetic force) of the compensation mechanism and the auxiliary seal A device to prevent fluid leakage.

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3. Dry gas sealing

Dry gas seal, or “dry-running gas seal”, is a new type of shaft end seal that uses slot sealing technology for gas sealing.

Features:

It has good sealing performance, long service life, no sealing oil system, low power consumption, simple operation and low operation and maintenance costs. As a maintenance-free sealing system that does not require any oil for cooling and lubricating the sealing end, dry gas seals replace floating ring seals and labyrinth seals and become the main seal of seals of high speed centrifugal compressor shaft in petrochemical industry.

Applicable occasions:

High-speed fluid machines such as centrifugal compressors are suitable for working conditions in which a small amount of process gas escapes into the atmosphere without damage, such as air compressors, nitrogen compressors, etc. .


4. Labyrinth Seal

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The labyrinth seal is a series of circular sealing teeth arranged in sequence around the rotating shaft. A series of interception spaces and expansion cavities are formed between the teeth. The sealed medium produces a strangling effect when passing through the spaces of the tortuous maze to prevent. leak.

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The labyrinth seal is the most basic form of sealing between the stages and shaft ends of centrifugal compressors. According to different structural characteristics, it can be divided into four types: smooth, zigzag, stepped and honeycomb.

1. Smooth labyrinth seal

The smooth labyrinth seal has two structures: integral and panel. It has a simple structure and is easy to manufacture, but the sealing effect is poor.

2. Zigzag labyrinth seal

The zigzag labyrinth seal is also divided into two structures: integral and panel. The structural feature of this labyrinth seal is that the sealing teeth extend to different heights, and the high and low teeth are arranged alternately. The corresponding shaft surface is specially designed. Concave and convex groove, this high and low tooth structure combined with concave and convex grooves, transforms the smooth sealing space into a zigzag type, thereby increasing the flow resistance and improving the efficiency of the sealing. waterproofing. But it can only be used in cylinders or partitions with horizontally divided surfaces, and the sealing body must also be horizontally divided type.

3. Stepped labyrinth seal

The structure of stepped labyrinth seal is similar to that of smooth labyrinth seal, but the sealing effect is similar to that of zigzag labyrinth seal. It is often used at the wheel cover and balance plate.

4. Honeycomb labyrinth seal

The sealing teeth of the honeycomb labyrinth seal are welded in a honeycomb shape to form a complex-shaped expansion chamber. Its sealing performance is better than ordinary sealing forms and is suitable for occasions with large pressure differences, such as scale. plate seal of a centrifugal compressor. The manufacturing process of honeycomb labyrinth seal is complex, the sealing sheet has high strength and good sealing effect.


5. Oil seal

The oil seal is a self-tightening lip seal with simple structure, small size, low cost, easy maintenance and low resistance torque. It can not only prevent medium leakage, but also prevent the intrusion of external dust and other harmful substances. is effective against It has some ability to compensate for wear, but it is not resistant to high pressure, so it is generally used in chemical pumps in low pressure situations.


6. Seal of Power

When the chemical pump works, the pressure head generated by the auxiliary impeller balances the high pressure liquid at the outlet of the main impeller to ensure sealing. When parking, the auxiliary wheel does not work, so a parking sealing device must be equipped to solve the chemical pump leakage that may occur during parking. The auxiliary wheel seal has a simple structure, reliable sealing and long service life. It cannot cause any leakage during chemical pump operation. Therefore, it is often used in chemical pumps that transport fluids containing impurities.


7. Spiral seal

The spiral seal is also a form of dynamic seal. It is a spiral groove machined on the rotating shaft or the sleeve containing the shaft, and the sealing medium is filled between the shaft and the sleeve. Rotating the shaft causes the spiral groove to act as a pump, preventing leakage of the sealing fluid. Sealing capacity is related to helix angle, pitch, tooth width, tooth height, tooth length and space between shaft and sleeve. As there is no friction between the joints, its service life is long. However, due to limited structural space, its spiral length is generally short, so its sealing ability is also limited. When the pump speed is reduced, its sealing effect will be significantly reduced.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

Datong Okuma CNC Lathe

The secret of Datong Okuma CNC lathe tool setting method

Great Light CNC Machining Services 11/01/2025 18:12

In the field of CNC lathe processing,Datong Okuma CNC LatheIt is favored for its high precision and stability. As a key part of the operation of CNC lathes, tool adjustment is precise and directly affects the processing precision and quality. Below I will reveal how to adjust the knife.

　　1. Tool adjustment on the X axis

First, perform tool calibration on the X axis of the cylindrical turning tool. Install the tool on the tool holder, start the Datong Okuma CNC lathe, manually operate the tool close to the workpiece along the Z axis direction, and then cut the outer circle of the workpiece. Note that do not move the X axis coordinates yet. When the cut is complete, retract the tool along the Z axis and stop the spindle rotation. Use vernier calipers to accurately measure the diameter of the outer circle you just turned. Then enter the tool offset page of the CNC system, search for the corresponding tool number, enter the measured diameter value, and the system will automatically calculate and store the tool offset value in the direction of X axis.

If you are using an internal hole turning tool, the steps are similar. Only after turning the inner hole is the diameter of the inner hole measured. The measured value is also entered into the corresponding position on the tool compensation page to complete the tool calibration on the X axis.

　　2. Tool adjustment on Z axis

For setting a tool on the Z axis, whether it is an external turning tool or an internal hole turning tool, the operation is basically the same. Manually control the tool to approach the workpiece along the X-axis direction, and then cut the end face of the workpiece. After cutting, retract the tool along the X-axis direction, keeping the Z-axis coordinate unchanged. Enter the tool compensation page of the CNC system and enter “0” in the Z axis compensation position corresponding to the tool number. This completes the Z-axis tool calibration and determines the zero point position of the tool in the Z-axis direction.

　　3. Thread knife adjustment

Adjusting the thread cutter is relatively complicated. In addition to basic tool setting operations on the X and Z axes like external turning tools, special attention should be paid to the tip angle and installation position of the threading tool. Since thread processing requires extremely high tool position accuracy, when installing a thread cutter, ensure that the tip of the thread cutter is at the same height as the center of the part and that the profile angle of the tool is consistent with that of the wire being processed. During the tool setting process, the X and Z axis tool setting methods are the same as ordinary tools, but before thread processing, it is necessary to further check and refine the position of the tool when cutting the thread to ensure the precision of thread processing.

　　4. Setting up tools with multiple tools

When multiple tools are used for processing, after the calibration of the first tool is completed, the calibration of subsequent tools can be based on it. Install the following tools on the tool holder in order, carry out trial cutting operations in the X and Z axis directions, measure the difference with the first tool in the X and Z directions, and then input the difference into the corresponding tool number. of the CNC system. In the compensation value, the setting of multiple tools can be completed.

Mastering the tool setting method of Datong Okuma CNC lathe requires patience and care. Each step of the operation must be precise to ensure that the tool is in the best position during the processing process, thereby processing high-quality parts that meet precision requirements. Through continued practice and practice, operators can skillfully use these tool setting methods to maximize the efficiency of CNC lathes.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: Talk about the life cycle of machine tool products

Great Light CNC Machining Services 11/01/2025 17:44

According to the product life cycle theory proposed by Harvard University professor Raymond Vernon, products, like human life, go through cycles of formation, growth, maturity, and decline. As for machine tool products, they also need to go through a process of introduction, growth, maturity and decline.

1. Introductory period

New products are brought to market. At this stage, production batches are small, manufacturing costs are high, sales prices are high, sales volume is very low, and the company’s profit margin is limited. Such as five-axis linkage machining center, complete equipment automatic line, special machine and other series of products;

–The concept of five-axis linkage machining centers originated in Europe, and Japanese composite machining machines emerged in the late 1970s and early 1980s. Although my country started Lately, domestic users have used a large number of imported five-axis linkage machining centers for processing complex parts. According to incomplete statistics, by the end of 2015, more than 20 domestic enterprises had started to develop and manufacture five-axis machining centers, launching a series of five-axis products, breaking foreign technology blockades, serving domestic strategic industries and occupying the highest point of strategic industries.

–Automatic lines have become a new trend in the development of the industry. On the one hand, automatic lines can significantly improve production efficiency. On the other hand, humans do not participate in the production process. All part captures and inspections are carried out by robots. , which avoids manual installation errors and ensures consistent processing dimensions. Good, the scrap rate is low, thirdly, it can reduce the workload of workers and greatly reduce labor costs. In recent years, large domestic machine tool enterprises such as Shenyang, Dalian, Anyang and Pleasant have launched various types of flexible manufacturing units, production lines and automatic production lines, which has led to improvements rapid changes in product quality and application levels.

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–Although the market for special machine tool products is small, they have a high technical level, complex manufacturing, are less subject to market fluctuations, and have high profits. These are the special skills of companies in the current market decline. Taking the special pipe thread processing machine in the oil industry as an example, this type of machine tool is suitable for processing various oil pipes, casings, pipe fittings, drill pipe joints, cones, claws and other oil industry parts. It can turn straight lines, oblique lines, arcs, metric threads and straight taper threads, and has multiple functions such as tool nose radius compensation. Currently, leading companies in the industry are developing special machine tools.

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2. Growth period

The demand and sales of machine tool products increased rapidly, production costs decreased significantly, and profits increased rapidly. Such as gantry machining center, horizontal machining center and other series of products;

–International mainstream machine tools of gantry machining centers can be divided according to structure into: movable fixed beam and fixed column worktable, movable beam fixed column worktable with lifting beam, fixed movable beam and fixed column working table, bridge type gantry structure, etc. . According to relevant data from the Machine Tool Association, the annual domestic market demand is about 2,000 units. The specifications of domestic machine tools are mainly concentrated in workbench widths of 1.25-3m. The products are mainly fixed beams, fixed columns and. types of mobile workbenches. Foreign machine tools use movable beams as the main body, and the fixed beam structure is gradually replaced by passive beams due to restrictions on the height of processed parts and processing precision.

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–Horizontal machining centers are divided into fixed column types and movable column types depending on whether the column moves. According to relevant data from the Machine Tool Association, the annual domestic market demand is around 2,500 units. The series product workbench is concentrated in specifications from 500 × 500mm to 1600 × 1600mm, among which the three specifications of workbench size 500 × 500mm, 630 × 630mm and 800 × 800mm are the most requested series.

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3. Maturity period

After the growth period, as production and sales of machine tools continue to increase, market demand tends to be saturated. During this stage, sales growth slowed and product profits declined due to increased competition. Such as popular CNC lathes, vertical machining centers and other series of products;

At present, domestic machine tool enterprises have fundamentally mastered the manufacturing technology of popular CNC lathes and vertical machining centers. Popular CNC lathes and vertical machines are increasing year by year and are the focus of the future development of the industry. The main parameters and structural performance of popular CNC lathes and vertical machining machines are basically similar to those of domestic enterprises, and the competition in homogenization is fierce. The single spindle, single tool holder and single workbench structure affects the processing efficiency. This type of machine tools abroad is only used for teaching and small batch single-part production.

–Popular CNC lathes. Domestic companies generally use an integrated bench and 45° (30°/60°) inclined guide rail arrangement. According to relevant data from the Machine Tool Association, the annual domestic market demand is about 35,000 units. . The maximum cutting diameter φ200-300mm is the most demanded.

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–Vertical machining centers can be divided into pyramid structure, C type and gantry type according to the vertical structure of the machine bed. According to relevant data from the Machine Tool Association, the annual demand for Lika in the domestic market is around 40,000 units; through preliminary market analysis, Lijia economic products such as culture, education, scientific research and general mechanical processing will become the focus. competition, with economic models accounting for 30% of the total demand for Lika % market share, while the VMC850 specification is the largest in terms of market demand.

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4. Recession period

The life cycle of machine tool products gradually ends and they are eventually completely withdrawn from the market. Such as ordinary machine tools (ordinary lathes, radial drills, ordinary boring machines, grinders, planers, etc.), economical CNC machine tools (economical CNC lathes, drilling machines, milling machines, etc.) are mass produced.

–Western developed countries completed the upgrade of their ordinary machine tools to CNC machine tools between the late 1970s and early 1980s, while China basically completed this process after 2013. technical transformation of users and bulk purchase of ordinary equipment are already minimal. The application of ordinary machine tools has gradually transformed from large-scale industrial production to a workshop supporting auxiliary equipment and spare parts maintenance tools. Market demand for regular towers has fallen from a peak of 125,000 units in 2011 to around 30,000 units. Affected by national conditions, the demand for ordinary machine tools will exist for a long time.

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–The economical CNC machine tool is unique in China. It is an improved product of ordinary machine tools and the starting product for the development of domestic CNC machine tools. It has a long development time and rich varieties although its functional level is low; , its price is low and it is popular among users of rough machining and general processing. According to data from the Machine Tool Association, the sales volume of economic CNC lathes accounts for 60% of the total CNC lathes, and the value accounts for 30% of CNC lathes. Its market demand has fallen from a peak of 120,000 units in. 2011 at around 40,000 units. The demand will exist for a long time due to the impact of national conditions.

Product life cycle theory analysis helps companies clarify their positioning and plays an important guiding role in formulating product competition strategies. It can identify gaps and deficiencies in existing products, deeply analyze root causes, and propose effective countermeasures for product development. Provide ideas for deepening the market and planning development.


Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

What are the advantages of magnetic separators?

What are the advantages of magnetic separators?

Great Light CNC Machining Services 11/01/2025 17:10

Magnetic separator is an important equipment which uses magnetic separation technology to separate magnetic and non-magnetic substances. It is widely used in many fields such as mining, metallurgy, environmental protection, food processing, medicine and materials science. The basic principle is to use magnetic differences produced by substances in a magnetic field for separation. When the material passes through the separator, the magnetic material will be affected by the magnetic force, but the non-magnetic material will not be affected, so the separation of magnetic material and non-magnetic material can be achieved.

　　Magnetic separatorSpecific work steps:
1. Feeding: The material to be separated enters the separation device of the separator through the feeding device.
2. Magnetic field effect: One or more strong magnetic field sources (such as electromagnets or permanent magnets) are installed in the separator when the material enters the magnetic field, magnetic substances and non-magnetic substances are separated according to the difference in magnetic field. force.
3. Separation: Magnetic substances are adsorbed on the magnetic field source and form magnetic clusters, while non-magnetic substances continue to be transported forward, finally realizing the separation of the two.
4. Discharge: Discharge the separated magnetic materials and non-magnetic materials separately through the discharge device.
Areas of application:
1. Mining and metallurgy: used for ore processing, such as the separation of iron ore, gold ore and copper ore, to improve the grade and recovery rate of minerals.
2. Environmental protection: During sewage treatment and waste recycling, magnetic pollutants, heavy metals or other harmful components in the water are separated to reduce environmental pollution.
3. Food industry: In the food production process, iron filings and metal impurities present in raw materials are removed to ensure product safety and quality.
4. Medicine and biotechnology: extract biological samples such as biomolecules, cells, viruses, etc., and apply them to cell separation, immunoprecipitation and other experiments.
5. Materials science: modify materials, isolate required functional materials, and improve the performance and application value of materials.
6. Chemical Industry: In terms of catalyst separation and recovery, it helps to improve catalytic efficiency and reduce operating costs.
Advantages of magnetic separators:
1. High efficiency: It can quickly and efficiently separate magnetic and non-magnetic substances, with short separation time and high production efficiency.
2. Environmentally friendly: Compared with traditional separation methods (such as chemical separation), it has no pollution, no chemical reagent residue, and is more environmentally friendly.
3. Wide adaptability: A variety of materials can be processed, from ores to biological samples, and a suitable separator can be selected for each material according to its characteristics.
4. Simple operation: The operation and maintenance of the equipment is relatively simple. Users can adjust the working parameters as needed to accommodate different separation needs.
5. Energy-saving and efficient: The electromagnetic separator has high efficiency in magnetic field intensity and can achieve good separation effects with low power consumption.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

CNC Knowledge: Has the precision of machine tools suddenly declined? 4 diagnostic principles and 5 diagnostic methods

Great Light CNC Machining Services 11/01/2025 16:42

The causes of abnormal machining precision defects are very hidden and difficult to diagnose. Today I have summarized the 4 diagnostic principles and 5 diagnostic methods for you. Do you know them all?

1

Causes of abnormal machining precision failures

Five main reasons: the power unit of the machine tool is changed or modified; the zero offset of each axis of the machine tool is abnormal; the axial play is abnormal; the working condition of the engine is abnormal, that is, the electrical and control parts; are abnormal; mechanical failure, such as screws, bearings, couplings and other components.
In addition, processing program preparation, tool selection, and human factors can also lead to abnormal processing accuracy.

2

Principles of fault diagnosis of CNC machine tools

1/. Look at the outside first, then the inside. CNC machine tools are machine tools that integrate mechanics, hydraulics and electricity, so the occurrence of defects will also be comprehensively reflected by these three elements. Maintenance personnel should first carry out inspections one by one from outside to inside, and try to avoid random unpacking and disassembly, otherwise the fault will be amplified, the machine tool will lose precision and performance will be reduced.
2/. Mechanical first, then electrical. Generally speaking, mechanical faults are easier to detect, but diagnosing CNC system faults is more difficult. Before troubleshooting, be sure to eliminate mechanical faults first, which often achieves twice the result with half the effort.
3/. Static first, then dynamic. Firstly, in the static state of the machine tool off, through understanding, observation, testing and analysis, the machine tool can only be powered on after confirming that this is a non-destructive defect. ; under operating conditions, carry out dynamic observation, inspection and testing to detect defects. In the event of destructive faults, the danger must be eliminated before the device can be switched on again.
4/. Simple at first, then complex. When multiple defects are intertwined and hidden and you don’t know where to start, you need to solve the easy problems first, then the more difficult ones. Often, once simple problems are solved, difficult problems can become easier.

3

CNC machine tool fault diagnosis method

1/. Intuitive method (look, hear, ask and guess) to ask – machine tool fault phenomena, processing conditions, etc. ; watch – CRT alarm information, alarm lights, deformation of capacitors and other components, smoke and burnt, protector tripping, etc. ; listen – anomaly Sound; odor – the smell of burnt electrical components and other odors touch – heat, vibration and poor contact, etc.

2/. Parameter Check Method Parameters are usually stored in RAM. Sometimes the battery voltage is insufficient, the system is not turned on for a long time, or external interference will cause settings to be lost or confused. calibrated according to the characteristics of the fault.

3/. Isolation method: For some faults, it is difficult to distinguish whether they are caused by the CNC part, the servo system or the mechanical part. The isolation method is often used.
4/. The same-type swap method replaces the suspected defective module with a replacement board with the same function, or swaps models or units with the same function.

5/. Functional program testing method: Write a few small programs for all instructions of G, M, S and T functions. Run these programs during fault diagnosis to determine the lack of functions.

4

Examples of machining precision abnormal fault diagnosis and treatment

1/. Mechanical failure results in abnormal processing accuracy

Fault phenomenon: An SV-1000 vertical machining center uses the Frank system. During the processing process of the connecting rod mold, it was suddenly discovered that the Z axis feed was abnormal, causing a cutting error of at least 1mm (Z direction overcut).

Fault Diagnosis: During the investigation, it was learned that the fault occurred suddenly. The machine tool jogs and each axis operates normally in manual data entry mode and returns to the reference point normally. There is no alarm prompt, and the possibility of a serious fault in the electrical control part is eliminated. The following aspects should mainly be checked one by one.

Check the segment of the processing program running when the machine tool accuracy is abnormal, especially the tool length compensation, calibration and calculation of the processing coordinate system (G54- G59).
In jogging mode, the Z axis was moved repeatedly and the movement status was diagnosed by sight, touch and hearing. It was found that the noise in Z direction movement was abnormal, especially in fast jogging mode. more obvious. Judging from this, the machines may contain hidden dangers.

Check the accuracy of the Z axis of the machine tool. Move the Z axis with a manual pulse generator (set the magnification to 1 × 100, i.e. the motor advances 0.1 mm for each step) and observe the movement of the Z axis with a dial indicator. Once unidirectional movement remains normal, it serves as the starting point for forward movement. Each time the pulse changes by one step, the actual distance of the Z axis movement of the machine tool is d=d1=d2=d3=… …=0.1mm, which shows that the motor runs well and the positioning accuracy is also good.
Returning to the changes in the actual movement of the machine tool, it can be divided into four stages: (1) The movement distance of the machine tool d1>d=0.1mm (the slope is greater than 1); the expression is d1=0.1 mm>d2>d3 (the slope is less than 1); (3) The machine tool mechanism does not actually move, showing the most standard clearance (4) The movement distance of the machine tool is equal to the predetermined distance; value of the pulser (the slope is equal to 1), and the machine tool returns to normal movement.

Regardless of how the clearance is compensated, its characteristic is that except for compensation in step (3), changes always exist in other steps, especially in step (1), which seriously affects the machining precision of the machine tool. During compensation, it was found that the greater the gap compensation, the greater the distance traveled in step (1).

After analyzing the above inspection, we believe that there are several possible reasons: first, there is an abnormality in the engine, second, there is a mechanical failure, and third, there is a gap in the screw. In order to further diagnose the fault, completely disengage the motor and screw, and inspect the motor and mechanical parts respectively. The inspection result is that the engine is operating normally; When diagnosing the mechanical part, it was found that when the screw is turned by hand, there is a great feeling of emptiness at the start of the return movement. Under normal circumstances, you should be able to feel the bearing moving in an orderly and smooth manner.

Troubleshooting: After disassembly and inspection, it was found that the bearing was indeed damaged and the balls fell out. The machine returned to normal after replacement.

2/. Machine tool position problems lead to abnormal machining accuracy.

Fault phenomenon: a vertical CNC milling machine produced in Hangzhou, equipped with the Beijing KND-10M system. While jogging or machining, a Z axis abnormality was detected.

Fault Diagnosis: Inspection found that the Z axis moved up and down unevenly and made noise, and there was a certain gap. When the motor starts, there is an unstable noise and uneven force in the upward movement of the Z axis in jogging mode, and the motor shakes when going down, the shaking is not so obvious that there has no jerks when stopping. This is more obvious during processing.

There are three reasons for the failure: first, the screw clearance is very large; second, the Z axis motor works abnormally. Third, the pulley is damaged to the point of being under uneven stress.

But one thing to note is that there is no jitter when stopping, and the up and down movement is uneven, so the problem of abnormal motor operation can be eliminated. Therefore, the mechanical part is diagnosed first, and no abnormality is found during the diagnostic test, which is within the tolerance. Using the rule of elimination, the only problem remaining was the belt. Upon inspection of the belt, I found that this belt had just been replaced. However, when I carefully inspected the belt, I found that there were varying degrees of damage inside. side of the belt. This was obviously due to uneven force, what is the cause? During diagnosis, it was found that there was a problem with the placement of the motor, i.e. the angular position of the clamp was asymmetrical, causing uneven stress.

Troubleshooting: Simply reinstall the motor, align the angle, measure the distance (motor and Z-axis bearing) and make sure the belt (length) is equal on both sides. In this way, the irregular movement of the Z axis up and down as well as noise and jitter are eliminated and the machining on the Z axis returns to normal.

3/. System parameters are not optimized and the engine operates abnormally.

The system parameters that lead to abnormal machining accuracy mainly include the machine tool power unit, work offset, backlash, etc. For example, the Frank CNC system has two power units: metric and imperial. During the repair process of the machine tool, local processing often affects the zero offset and backlash changes. Timely adjustments and modifications should be made after the fault is resolved. On the other hand, serious mechanical wear or loose connections can also cause measured parameter values. For a change. Changes in parameters require corresponding modifications to meet the processing precision requirements of the machine tool.

Fault phenomenon: a vertical CNC milling machine produced in Hangzhou, equipped with the Beijing KND-10M system. During the machining process, it was found that the accuracy of the X axis was abnormal.

Fault Diagnosis: Inspection found that there is a certain deviation in the X axis and the motor is unstable when starting. When you touch the X-axis motor with your hand, you feel that the motor pulls strongly, but the pull is not obvious when it stops, especially in inching mode. The analysis believes that there are two reasons for the failure: first, the screw clearance is very large; second, the X axis motor works abnormally.

Troubleshooting: Use the KND-10M system parameter function to debug the motor. First, the existing deviation is compensated, and then the servo system parameters and pulse suppression function parameters are adjusted. The jitter of the X-axis motor is eliminated, and the processing precision of the machine tool returns to normal.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: What are the differences between three, four and five axis CNC machining centers?

Great Light CNC Machining Services 11/01/2025 15:41

In recent years, through continuous innovation and updating, CNC machining centers have derived from three-axis, four-axis or five-axis machining centers, compound turning-milling CNC machining centers, etc. Today I will tell you about the features of three different CNC machining centers: three-axis, four-axis and five-axis machining centers.

Three-axis CNC machining: generally refers to three axes of linear motion with variable speed in different directions, such as left and right, up and down, forward and backward. The three-axis machine can only process one surface at a time, which is more suitable for processing certain disc parts.

Four-axis CNC machining: Place another rotation axis on the three axes, usually the reference plane rotates 360 degrees. But it can’t run at high speed. It is more suitable for processing certain parts of boxes and shells.

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Five-axis machining center CNC machining: There is an additional axis of rotation in the four axes, generally 360° rotation of the vertical surface. The five-axis machining center has achieved comprehensive processing and can reduce the clamping cost with just one clamping. . Reduces the damage caused by scratches on the product and is more suitable for multi-station pore and plane processing, as well as parts requiring high processing precision, especially parts that require more strict shape processing precision .

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Although five-axis machining centers have greater competitive advantages than four- and three-axis machining centers. In fact, not all products are suitable for five-axis machining centers, and those suitable for three-axis machining may not be suitable for five-axis machining centers if the products that can be processed with three axes are used in five. Axis machining centers, not only will production increase, but the actual results may not be good.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

CNC Knowledge: 399 Mechanical Common Sense Questions Mechanical Engineers Should Know, it’s good stuff, no need to say more, just save it

Great Light CNC Machining Services 11/01/2025 14:38

1. What are the main forms of metal structures?

Answer: There are frame structures, container structures, box structures and general component structures.

2. Into how many parts can the riveting operation be divided depending on the nature of the process?

Answer: It is divided into material preparation, placing, processing and forming, assembly and connection.

3. What are the methods of connecting metal structures?

Answer: There are hybrid riveting, welding, riveting-welding and bolting connections.

4. In the machinery manufacturing industry, riveters belong to the heat treatment category.

5. What is heat treatment?

Answer: All or part of the metallic material is heated and transformed into shape.

6. What is the main structure of the truss structure?

Answer: This is based on profiles.

7. What is the main structure of the container structure?

Answer: It is based on plates.

8. The box structure and general structure are made of a mixture of plates and profiles.

9. Material preparation refers to the preparation of raw materials and part blanks.

10. Steel plates and profiles may be deformed during transportation, lifting and storage.

11. Steel deformation will affect the normal progress of parts such as lifting, cutting and gas cutting.

12. If the deformation of parts during processing is not corrected, it will affect the proper assembly of the structure.

13. The deformation caused by welding will reduce the assembly accuracy, generate additional stress inside the steel structure, and affect the strength of the components.

14. Deformation of flat steel includes bending, twisting, and combined bending and twisting deformation.

15. What types of multi-roll straighteners can be classified based on the arrangement of shaft rollers and position of adjusting rollers?

Answer: It can be divided into upper and lower roller row parallel straightening machines and upper and lower roller tilt straightening machines.

16. What are the heating methods for flame correction?

Answer: There is point, line and triangle heating.

17. What factors determine the effect of flame correction?

Answer: Determined by heating location and heating temperature.

18. What are the correction methods?

Answer: Mechanical correction, manual correction, flame correction and high frequency thermal correction.

19. What is the first step in manufacturing a metal structure?

Answer: The layout and numbering of materials constitute the first process of manufacturing a metal structure.

20. How does staking and numbering impact the product?

Answer: It will directly affect the product quality, production cycle and cost.

21. What quantities are commonly used for staking?

Answer: There are wooden folding rulers, rulers, steel tape measures and steel board rulers, etc.

22. What are the commonly used tools for staking?

Answer: There are marking gauges, floor gauges, sample punches, marking needles and small hand hammers.

23. What is the procedure to follow to establish a real quantity?

Answer: The procedures are linear smoothing, structural smoothing and unfolding smoothing.

24. What is the content of the extension?

Answer: There are plate thickness processing, drawing expansion and digital material sample production.

25. What are the categories of models according to their uses?

Answer: There are material samples, type checking samples and positioning samples.

26. What materials are typically used to make samples?

Answer: Use thin iron sheets with a thickness of 0.5-2mm.

27. What are the main methods of drawing models and samples of columns?

Answer: There is a straight line drawing method and a transition drawing method.

28. How to use materials rationally?

Answer: It is necessary to focus on the arrangement and use of the remaining materials.

29. What types of curves are there?

Answer: It is divided into plane curve and spatial curve.

30. What are the methods to find the real length of a line segment?

Answer: There is the rotation method, the right triangle method, the branching method and the area change method.

31. What are the steps to follow to develop a sample?

Answer: Through geometric drawing, first draw intersecting lines, real long lines and real cross-section shapes, then create a developed diagram.

32. What is the basic method for finding plane, solid intersecting lines?

Answer: Edge method and Edge method.

33. What is the basic method for finding the line of intersection of a curved surface?

Answer: These are the longitude method and the latitudinal method.

34. What is the main method for finding intersecting lines?

Answer: These are the auxiliary plane method, the main line method and the spherical surface method.

35. What are the characteristics of intersecting lines?

Answer: (1) Line of intersection is the common line and dividing line between two intersecting shapes. (2) Since the shape has a certain range, the intersection line is always closed.

36. What is the line of intersection?

Answer: The intersection between the cross-sectional plane and the solid surface.

37. What is a frontline?

Answer: Any position of the busbar on the surface of the component is called main line.

38. What are the commonly used expansion methods?

Answer: There is the parallel line method, the radial line method and the triangle method.

39. What are common ways to divide a sphere?

Answer: There is the strip method, the block method and the division method.

40. What is the main content of sheet metal thickness processing?

Answer: Determine the neutral layer of the bent part and eliminate plate thickness interference.

41. How is the material length of angle steel bent parts calculated?

Answer: Calculated based on the center of gravity layer.

42. What types of shears are there for cutting straight lines?

Answer: There are gantry bevel shears, beam bevel shears and combined punching and shearing machines.

43. What types of machine tools are there for shear curves?

Answer: There are disc shears and vibrating shears.

44. What are the characteristics of vibrating shears?

Answer: The vibrating shear can cut various curves and interior holes.

45. What is a combined shear-punching machine?

Answer: It consists of diagonal shears, steel shears and small punches.

46. ​​​​​​​​Try to analyze the transmission sequence of the shear.

Answer: The sequence comes from the original moving parts – transmission parts – workpiece.

47. What is the function of the front and rear baffles of the gantry shear?

Answer: Mainly for positioning.

48. What are the positioning shapes of the shear on a gantry or oblique shear?

Answer: There are shear plate positioning shears, tailgate positioning shears and baffle positioning shears.

49. How can the shear force acting on the material be broken down?

Answer: It can be divided into shear force, horizontal tension force and separation force.

50. What materials are not suitable for shearing machines?

Answer: It is not suitable for cutting alloy materials and hardened materials.

51. How to choose the cutting oxygen pressure?

Answer: It should be selected based on the thickness of the workpiece, the diameter of the torch nozzle and the purity of the oxygen.

52. What is the flash point of general carbon steel in oxygen?

Answer: about 1100℃~1150℃.

53. What metal materials can meet the conditions of gas cutting?

Answer: There are pure iron, low carbon steel, medium carbon steel and ordinary low alloy steel.

54. What is the gas cutting process?

Answer: This includes preheating the metal, burning the metal and removing oxides.

55. What is the function of the round die? What does it consist of?

Answer: It is a tool used to process external threads. It consists of a cutting part, a positioning part and a chip removal hole.

56. What does the shape of the bevel have to do with?

Answer: It depends on the material type, thickness, welding method and mechanical properties of the product.

57. What is frosting?

Answer: Using a grinding wheel to treat the surface of a workpiece is called grinding.

58. What are the main types of grinding tools?

Answer: There are pneumatic grinders and electric grinders.

59. How much deformation will occur in the steel during the bending and forming process?

Answer: Both elastic deformation and plastic deformation will occur.

60. What are the bending and forming methods commonly used by riveters?

Answer: There are cold bending, hot bending, manual bending and mechanical bending.

61. What are the forms of bending deformation of the material during press bending?

Answer: There is free flexion, contact flexion and corrective flexion.

62. What is related to the change in transverse shape of the material during the bending process?

Answer: This is related to the relative radius of curvature, geometric characteristics of the cross section and the method of bending.

63. What is the method to prevent the blank from bending during folding?

Answer: There is a material holding device and positioning holes.

64. What types of bending and rolling machine tools are included?

Answer: Including sheet metal rolling machines and steel bending machines.

65. What are the main processes of manual pipe bending?

Answer: There is marking, sand filling and heated bending.

66. What are the methods of connecting metal structures?

Answer: There are three types: riveted connection, threaded connection and welding.

67. What should be considered when choosing a join method?

Answer: Factors such as component strength, working environment, materials and construction conditions must be considered.

68. What are the shapes of riveted joints?

Answer: There are butt joints and corner joints.

69. What are the shapes of solid rivet heads?

Answer: There are half round heads, countersunk heads and half countersunk heads.

70. What are the main types of AC arc welding machines?

Answer: There are BX1-330 type and BX-500 type.

71. What is the basic operational process of hot riveting?

Answer: Fastening riveted parts, repairing holes, heating rivets, connecting and threading nails, jacking nails and riveting.

72. What are the types of riveting?

Answer: There are solid rivets, tight rivets and tight rivets.

73. What tools are used to repair holes?

Answer: There is a reamer.

74. What are commonly used anti-loosening measures for threaded connections?

Answer: Increase friction and mechanically prevent loosening.

75. What is the welding arc?

Answer: It consists of an anodic zone, a cathodic zone and an arc column.

76. What are the main types of electric welding machines?

Answer: There are DC welding machines and AC welding machines.

77. What is local deformation? What is included?

Answer: It is the deformation that occurs in a certain part of the component, including angular deformation, wave deformation and local irregularities.

78. What types of welding are classified according to spatial position?

Answer: It is divided into horizontal welding, vertical welding, horizontal welding and overhead welding.

79. During the welding process, in which three directions does the welding rod move?

Answer: There is movement toward the weld pool, movement in the direction of welding, and lateral oscillation.

80. What are the three elements of assembly?

Answer: These are positioning, support and tightening.

81. What are manual pliers?

Answer: There are spiral pliers, wedge pliers, lever pliers and eccentric pliers.

82. What are non-manual pliers?

Answer: There are pneumatic grippers, hydraulic grippers and magnetic grippers.

83. What are the functions of spiral tweezers?

Answer: It has the functions of clamping, pressing, lifting and supporting.

84. What are the commonly used measuring items in assembly?

Answer: There are linear dimensions, parallelism, perpendicular, coaxiality and angle.

85. What is the support shape of the part in assembly?

Answer: There are assembly platform brackets and assembly tire frame brackets.

86. What types of tire frame assemblies can be divided based on their functions?

Answer: It can be divided into general tire frame and special tire frame.

87. What are the positioning methods commonly used in assembly?

Answer: There is line positioning, model positioning and positioning component positioning.

88. What are the basic methods for finding lines of intersection of planes?

Answer: There is an edge method and an edge method.

89. Hot riveting usually consists of four people. What is their division of labor?

Answer: One person heats and transfers; one person picks up the nails and threads them; one person pushes the nails and one person rivets;

90. What is the function of the flat shank of the taper shank drill bit?

Answer: It is used to increase the transmitted torque and prevent the drill bit from being drilled into the spindle hole or drill bush.

91. What is the function of the guide piece in the drill bit?

Answer: It can maintain the straight drilling direction of the bit during the cutting process. At the same time, it has the function of smoothing the wall of the hole and is also the backup part of the cutting part.

92. What undesirable phenomena will occur when the hole is about to be drilled?

Answer: When the drill bit simply pierces the workpiece, the axial resistance suddenly decreases. Due to the gap in the feed mechanism of the drill and the sudden recovery of elastic deformation, the drill bit automatically cuts off with a large amount of feed, resulting in. in case of drill breakage or poor drilling quality.

93. What is the role of cutting fluid during drilling?

Answer: Reduce friction, drill resistance and cutting temperature, and improve the cutting ability of the drill bit and the surface quality of the hole wall.

94. What is the reduction amount?

Answer: It is the general term for cutting speed, feed amount and depth of cut.

95. What is grinding?

Answer: It is a method of using a grinding wheel to process the surface of the workpiece.

96. What is expansion?

Answer: The process of spreading the surface or part of a metal structure on a plane in sequence according to its actual shape and size is called unfolding.

97. How many ways are there to draw an expanded diagram?

Answer: There is the parallel line method, the triangle method and the radial line method.

98. What are the conditions for expansion of the parallel line method?

Answer: The principal lines on the component surface are parallel to each other and the actual length is reflected on the projection surface.

99. What does plate thickness processing include?

Answer: Determine the neutral layer of the bent part and eliminate plate thickness interference.

100. What factors are related to the change in position of the neutral layer of the plate thickness?

Answer: This is related to the radius of curvature of the sheet and the thickness of the sheet.

101. What are the general principles of processing plate thickness of intersecting parts?

Answer: The expansion length is based on the size of the neutral layer of the component. The height of the curve in the expansion diagram is based on the height of the component contact point.

102. What is the main content of staking?

Answer: Processing plate thickness, unfolding drawings and creating material models based on the unfolding drawings of the produced components.

103. What shearing equipment is commonly used by riveters?

Answer: There are gantry shears, oblique shears, disc shears and punch shears combined with punching and shearing machines.

104. What types of plate rolling mills can be divided based on the number and arrangement of rolls?

Answer: There are three types: symmetrical three-roller, asymmetrical three-roller and four-roller.

105. How can punching dies be divided based on their structure?

Answer: It is divided into simple mold, guide pillar mold and composite mold.

106. What are the structural characteristics of composite cutting die? It has a convex and concave mold that functions as both a convex cutting mold and a convex punching mold.

107. What is strike force?

Answer: This is the maximum resistance of the material to the mold during cutting.

108. Into what stages can the process of separation deformation of metal sheets during cutting be divided?

Answer: It is divided into elastic deformation stage, plastic deformation stage and shear stage.

109. What is the minimum bend radius?

Answer: The minimum value of the radius of curvature that can be obtained without damaging the material.

110. What are common methods for reducing springback in press-bent parts?

Answer: There are mold correction methods and pressure correction methods.

111. What is the purpose of using a hold down during stretching?

Answer: Mainly to prevent the edges of stretched pieces from wrinkling.

112. What is the function of the crank link mechanism of a crank press?

Answer: Not only can it transform rotational motion into reciprocating linear motion, but it can also amplify force.

113. What does sheet metal processing include?

Answer: Including folding, bending, edge trimming, curling, sewing and patching.

114. What are the functions of development models?

Answer: It can be used to number materials, make parting molds and make milling patterns.

115. What does it mean to set aside? What are the training methods?

Answer: The operation of stretching and thinning the edge material of the deformed part during the molding process is called edge setting. Training methods include slimming and stretching.

116. What is destiny?

Answer: Use the edge pulling and closing methods to turn the edge of the sheet into a curved piece.

117. What is hem?

Answer: In order to increase the stiffness and strength of the workpiece edge, curling the workpiece edge is called curling.

118. What is a seam bite?

Answer: The edges of two sheets or both sides of a sheet are turned, engaged and pressed together, which is called a seam.

119. What is plate thickness processing?

Answer: A method adopted to eliminate the influence of plate thickness on the shape and size of the unfolded diagram.

120. What are the general steps to calculate the unfolded length of a folded part?

Answer: Divide the bent part into straight segments and arc segments; calculate the length of each segment separately; add the calculated lengths.

121. Under what circumstances should steel profiles be cut?

Answer: Angle steel, channel steel and I-beam are bent at angles.

122. What are the steps in the entire removal process?

Answer: There are three steps. Elastic deformation stage, plastic deformation stage and shear stage.

123. What is masking?

Answer: The stamping process uses a stamping plate to separate one part of the sheet from another part along a certain closed line.

124. How many types of bolted joints are there?

Answer: There are two types: the joint which supports axial tensile load and the joint which supports transverse action.

125. What are the anti-loosening measures for bolted joints?

Answer: Increases friction and mechanical anti-loosening.

126. What are the methods to avoid mechanical loosening?

Answer: Cotter pin, lock washer, lock washer and tandem wire.

127. What is welding arc?

Answer: A strong and lasting discharge phenomenon occurs in the gaseous medium between the two electrodes.

128. What parts does the welding arc consist of?

Answer: It consists of a cathode zone, an anodic zone and an arc column.

129. In which three directions does the welding rod move?

Answer: Move towards the weld pool, move in the direction of welding and swing side to side.

130. How many types of welds can be classified based on their spatial positions?

Answer: It is divided into flat welding, vertical welding, horizontal welding and overhead welding.

131. What are the characteristics of intersecting lines?

Answer: It is both a common line and a dividing line on the surfaces of two bodies. It is still closed in space.

132. What is a secant line?

Answer: A component composed of the intersection of two or more geometric bodies.

133. What are the factors that affect the quality of cutting?

Answer: The mold gap, the center lines of the convex and concave molds do not overlap, and the working edge of the mold is worn and blunt.

134. What are the general principles of mold design?

Answer: In order to guarantee the quality of stamping, we strive to design molds that are easy to manufacture, simple to implement, inexpensive and easy to use.

135. What is the purpose of calculating rolling force?

Answer: It is about choosing the calendering equipment correctly.

136. What is free flexion?

Answer: After bending is completed, the punch, blank and die fit together and no impact will occur.

137. What is corrective flexion?

Answer: These are the punch, the blank die and the concave die. Once all three are matched, there is an impact that corrects the bent parts.

138. What defects are likely to occur when pressing the head?

Answer: Roasting and bagging, tensile marks and straight pitting, microcracks on exterior surface, longitudinal tears, deflection, ellipse and inconsistent diameter.

139. What is an expansion joint?

Answer: The connection method uses the deformation of the pipe and the tubesheet to achieve sealing and tightening.

140. What is the purpose of calculating strike force?

Answer: In order to reasonably select equipment capabilities and design molds.

141. What method can be used to reduce striking force?

Answer: Beveled blade dies, stepped dies and heated dies.

142. What is the purpose of calculating bending force?

Answer: In order to choose the press brake and design the mold.

143. What does the degree of tensile strain include?

Answer: Including the degree of mold sticking and the allowable deformation degree of the material.

144. How to determine the number of drawings of a part?

Answer: Based on the maximum strain of the pulled part and elongation of the material.

145. How to determine the draft coefficient?

Answer: It depends on the material properties, the winding angle of the design, the coefficient of friction and whether the design is prefabricated.

146. What materials are not suitable for cold working?

Answer: Fragile materials such as high carbon steel, high alloy steel and cast iron.

147. What is the correction sequence when angles undergo complex deformation?

Answer: First correct the distortion, then correct the kink, and finally correct the angular distortion.

148. What are the causes of deformation of steel structures?

Answer: One is caused by an external force and the other is caused by internal stress.

149. What are the methods to eliminate welding residual stresses?

Answer: Global high temperature quenching, local high temperature quenching, temperature difference stretching method, mechanical stretching method and vibration method.

150. What is overall welding strain?

Answer: It refers to changes in shape and size of the entire structure.

151. What is the hammer expansion method?

Answer: The fibrous tissue of the sheet metal is elongated by hammering.

152. How to determine the length of the rivet shank?

Answer: It is determined based on factors such as the total thickness of the connected parts, the diameter deviation between the nail hole and the nail shank, and the riveting process.

153. What is the reason why the rivet head is too small after riveting?

Answer: Because the nail shank is short or the hole diameter is too large.

154. Depending on the condition of the metal during welding, how many types can it be divided into?

Answer: There are three types: fusion welding, pressure welding and brazing.

155. What is fusion welding?

Answer: This method uses local heating to bring the welded joint to a molten state.

156. What is tightening?

Answer: It involves using an external force to fix the positioned parts so that they remain in the same position during processing.

157. What is the six-point positioning rule?

Answer: Use six positioning points to limit the freedom of the part in space to completely determine the spatial position of the part.

158. What is relative parallelism?

Answer: It is the parallelism of the line or surface measured on the part relative to the measurement reference line or surface.

159. What is relative verticality?

Answer: It is the circularity of the line or surface measured on the workpiece relative to the baseline or surface of measurement.

160. What types of fixtures are used during assembly?

Answer: Assembly tools, assembly accessories and assembly spacers.

161. What are the commonly used mounting spreaders?

Answer: There are wire ropes, iron chains, manual chain hoists and special spreaders.

162. How many guide shapes are there for punching die?

Answer: There are three shapes: guide posts, guide sleeves and guide plates.

163. How many parts does the punching die consist of?

Answer: It consists of working part, material positioning part, unloading part and mold base.

164. What is the role of space in the drawing matrix?

Answer: Reduce the friction between the material and the die and control the flow of material into the die cavity.

165. How many types of bite spaces can be classified according to their structure?

Answer: It can be divided into vertical single bite seams, vertical double bite seams, horizontal flat bite seams and various corner bite seams.

166. What is the reason why the bent part bounces back when the external force is removed?

Answer: This is because when the sheet is folded manually, the outer surface of the sheet is stretched and the inner surface is compressed, causing rebound.

167. How to obtain cold camber and hot camber?

Answer: Cold bending is achieved by shrinking the edges of the sheet and widening the middle of the sheet, and hot bending is achieved by shrinking the sheet by heating.

198. How many methods are there to establish a relationship?

Answer: There are two types, one is to use a general tool to remove the edge and the other is to use a molded tire to remove the edge.

169. What is edge closure?

Answer: Edge closing involves first creasing the sheet and then flattening the creases to prevent stretch recovery. In this way, the shrinkage length of the sheet is reduced and the thickness is increased.

170. What is the basic principle of edge closure?

Answer: The principle is that for forming parts with convex curved edges, the material on the outer edge of the flat curved edge shrinks and becomes thicker and shorter, forcing the vertical edge to take a curved shape.

171. What is the purpose of correction?

Answer: By applying external force or local heating, the longer fibers are shortened and the shorter fibers are lengthened, and finally the fibers in each layer are aligned to achieve the correction goal.

172. What is the principle of flame correction?

Answer: It uses the deformation generated after local heating of the metal to compensate for the original deformation in order to achieve the correction objective.

173. What are the factors that affect the flame correction effect?

Answer: There are workpiece stiffness, heating position, flame heat, heating area and cooling method.

174. What are the heating methods for flame correction?

Answer: There is point, line and triangle heating.

175. What are the factors that determine process margin?

Answer: There are the effects of lofting errors, part processing errors, assembly errors, welding deformation and flame correction.

176. What categories can models be divided into based on their uses?

Answer: It can be divided into dial models, training models, positioning models and sampling rods.

177. What are the methods of drawing patterns?

Answer: There are two types, direct drawing method and transitional drawing method.

178. How to choose the implantation baseline?

Answer: Take two mutually perpendicular lines or surfaces, take two center lines as a reference line and take a plane and a center line as a reference line.

179. What error is allowed during implementation?

Answer: During the reset process, due to the influence of factors such as the accuracy of tool configuration and measuring tools, as well as the operation level, there will be a certain size deviation in the sampling. real sample, controlling this difference. within a certain range, we speak of an admissible implementation error.

180. What does structural lofting include?

Answer: Determine the joint position and connection shape of each part, make necessary changes according to the actual production and processing capabilities, calculate or measure the material length of the parts and the actual shape of the flat parts, and design the mold or frame.

181. What are the methods to find the real length of a line segment?

Answer: Rotation method, right triangle method, area change method and branching method.

182. What is the drawing rule for finding the actual length of a line segment using the right triangle method?

Answer: The projection of the line segment on any projection plane is used as one right-angled side of the right triangle, and the projection length of the corresponding projection on the axis perpendicular to the plane is used as another right-angled side, and its hypotenuse is the actual length of the line segment.

183. What is the rotation method to find the actual length?

Answer: It involves rotating the general position of space around a fixed axis into a parallel line, then projecting the line onto the projection plane parallel to it reflects the actual length.

184. What are the methods for finding the actual length of a curve?

Answer: There are face changing methods and expansion methods.

185. What is face change?

Answer: Simply set up a new projection surface parallel to the curve, then projecting the curve onto this surface will reflect the actual length.

186. What is the method of expansion?

Answer: The required expansion line is to straighten one length in the curved view and keep the height in the other view unchanged.

187. What are the fundamental characteristics of the line of intersection?

Answer: The line of intersection must be a plane figure surrounded by a straight line or a closed curve; the intersection line is the common line between the section plane and the three-dimensional surface, and is a set of points that both lie on the section plane. and on the three-dimensional surface.

188. What are the methods for finding three-dimensional intersection lines?

Answer: Edge method and Edge method.

189. What are the methods to find the three-dimensional intersection line of a curved surface?

Answer: Single thread method and weft thread method.

190. What are the characteristics of intersecting lines?

Answer: First, the common line that intersects the surfaces of two shapes is also the dividing line between the two intersecting shapes. Second, the intersecting lines are all closed.

191. What is the essence of finding intersecting lines?

Answer: It involves finding a certain number of common points on the surfaces of the two shapes, and connecting these common points in sequence to achieve what you want.

192. What are the selection principles for the intersecting line search method?

Answer: To use the principal line method to find the line of intersection, at least one projection of the line of intersection must be known; to use the auxiliary plane method to find the intersection line, the intersection line must be the simplest geometric figure; The surface method is only applicable at the intersection of rotating bodies and components whose axes cross.

193. Under what conditions is the secant line a plane curve? The frontal projection of a curve consists of two straight lines that intersect?

Answer: When two arbitrary rotating bodies circumscribed on the same spherical surface intersect, their line of intersection is a plane curve. At this moment, when the axes of the two rotating bodies are parallel to their base projection plane, the line of intersection lies on this surface. . The projection of consists of two straight lines which intersect,

196: What is a ruled surface?

Answer: It is the surface formed using straight lines as generator.

197: What are the characteristics of cylinders?

Answer: All main lines are parallel to each other. When the cylinder is cut by parallel planes, the cross-section shapes will be the same.

198: What are the characteristics of the surface of the cone?

Answer: All first lines intersect at a point, and when the cone is cut with parallel planes, the cross-section shapes are similar; the line of intersection passing through the vertex of the cone is a triangle.

199: During stamping, what are the stages of plastic deformation of the material?

Answer: Material bends, material is stretched and deformed, and material is stretched.

200: What is pull form?

Answer: It is a molding method in which the sheet material is plastically deformed to an ideal curved surface when under tension and overcomes springback.

201. What does plate thickness processing include?

Answer: Determine the neutral layer of the bent part and eliminate plate thickness interference.

202. What factors are related to the change in position of the neutral layer of the plate thickness?

Answer: This is related to the radius of curvature of the sheet and the thickness of the sheet.

203. What are the general principles of processing the plate thickness of intersecting parts?

Answer: The expansion length is based on the size of the neutral layer of the component. The height of the curve in the expansion diagram is based on the height of the component contact point.

204. What is the main content of staking?

Answer: Processing plate thickness, unfolding drawings and creating material models based on the unfolding drawings of the components made.

205. What is the working principle of the friction press?

Answer: It uses contact transmission of flywheel and friction plate and works based on the principle of relative movement of screw and nut.

206. What are the advantages of friction presses?

Answer: The movement is faster and the cursor can stop at any position in the stroke. When overloaded, it will only cause slippage between the flywheel and the friction plate without damaging the machine parts.

207. What are the advantages of the stamping process?

Answer: (1) High production efficiency. A press stunt can carry out a process, and sometimes several processes; (2) High material utilization rate (3) The shape and size of stamped parts of the same product are consistent and the interchangeability is good; operation, to facilitate the achievement of mechanized and automated production.

208. How many categories are stamping processes divided into?

Answer: (1) Separation process; (2) Forming process;

209. What is masking?

Answer: A stamping method that uses a die to separate sheet metal on a press.

210. How to distinguish between punching and masking?

Answer: Generally, the sheet metal forms two parts after punching, namely the cut part and the holed part. If the purpose of punching is to produce a workpiece with a certain shape, that is, the cut workpiece is called blanking, on the contrary, the purpose of punching is to process an inner hole of a certain shape and the cut piece; is called the punch.

211. When cutting, what are the steps for separating materials?

Answer: Elastic deformation, plastic deformation and separation by cracking.

212. How many methods are there to reduce strike force?

Answer: There are three types: inclined edge punching, stepped punching and blank hot punching.

213. What is the minimum radius of curvature?

Answer: The minimum limit value of bend radius when the material is bent without causing damage is called minimum bend radius.

214. What types of external forces cause structural parts to deform?

Answer: Including bending force, torsion, impact force, tension and pressure, etc.

215. What can happen inside a component due to an external force? When the external force is removed, some of the internal force may remain, and what will be formed?

Answer: An external force can cause an internal force to appear inside the component. When the external force is removed, an internal stress is formed.

216. What is the welding process for metal structural parts? What is the main cause of component deformation?

Answer: It is an uneven heating and cooling process: it is the main cause of deformation caused by internal stresses of components.

217. In what directions does the shrinkage of the weld and metal near the weld mainly manifest?

Answer: Mainly manifested by shrinkage in the longitudinal and transverse directions.

218. What are the design factors that can cause deformation of structural parts?

Answer: The rationality of the structure, the position of the weld and the shape of the weld groove, etc.

219. What are the factors that can cause deformation of structural parts in terms of process?

Answer: Regulations on welding processes, welding sequence numbers, anti-deformation measures, etc.

220. What is the prerequisite for carrying out correction work with quality and quantity?

Answer: The premise is correct judgment and selection of the corrective position.

221. When analyzing the causes of component deformation, it is necessary to distinguish what causes the deformation?

Answer: It is necessary to distinguish whether the deformation is caused by an external force or an internal stress.

222. What are the three deformations of Gong-shaped beams?

Answer: Arch deformation, lateral bending and angular deformation.

223. What are the two deformations of box girders?

Answer: There is deformation and distortion of the arc.

224. What is the main contradiction when both deformations of box beams appear at the same time? In what order should the correction be made?

Answer: Distortion is the main contradiction. It should be performed in the order of twisting first, then arching.

225. What is internal force?

Answer: When an object is deformed by an external force, a force that resists the deformation appears inside it. This force is called internal force.

226. What is stress?

Answer: When an object is subjected to the action of an external force, the internal force that appears on the unit cross section is called stress.

227. What is internal stress?

Answer: When no external force acts on it, the stress existing inside the object is called internal stress.

228. What is local deformation?

Answer: Deformation occurs in a certain part of the component, called local deformation.

229. What is global deformation?

Answer: Changes in the shape and size of the entire component are called global deformation.

230. What is shrinkage deformation?

Answer: One of the fundamental forms of deformation mainly refers to deformation in which an object is shortened and deformed after being heated and cooled.

231. What is distortion?

Answer: One of the basic forms of distortion is distortion in which the length of the object does not change, but its straightness exceeds the tolerance.

232. What is angular deformation?

Answer: One of the fundamental forms of warping refers to changing the angle between parts of an object beyond tolerance, called angular warping.

233. What is a patch site?

Answer: The position where the correction means are applied to the deformation of the steel structure, sometimes the correction part is not necessarily the deformation part of the component.

234. What are steel structural components?

Answer: A variety of parts are connected together by various methods such as welding, riveting or bolting. These parts are interconnected and bound together to form an organic whole, generally referred to as structural steel parts.

235. What are the causes of deformation of steel structural parts?

Answer: There are two reasons: deformation caused by external force and deformation caused by internal stress.

236. What are the main forms of welding deformation?

Answer: Longitudinal and transverse shrinkage deformation, bending deformation, torsional deformation and angular deformation.

237. What are the characteristics of thin steel sheets used in steel structures?

Answer: Thin plates used in steel structures are often assembled or welded with different types of frames and are limited by the frames.

238. The degree of transverse deformation when a pipe is bent depends on the values ​​of the relative radius of curvature and the relative wall thickness, correct?

answer.

239. When the pipe is bent, the greater the relative radius of curvature and relative wall thickness, the greater the deformation, right?

Answer: No.

240. If the curvature of the elbow pipe is not enough but similar, the curvature can be increased by cooling the outside of the pipe with water to shrink the metal inside, right?

Answer: No.

241. At present, generally for on-site pipe bending, when the requirements for the ovality of the bending deformation section are not too strict, anti-deformation devices are often not installed when of using coreless elbows, right?

Answer: No.

242. According to the transmission mode, tube bending machines are divided into two types: mechanical transmission and gear transmission, right?

Answer: No.

243. There are two limit switches on the pipe bender. The required bending length can be controlled by adjusting the position of the cap, right?

answer.

244. Hydraulic pipe bender features smooth and reliable transmission, low noise, compact structure and the ability to bend different pipe blanks, isn’t it?

Answer: No.

245. The method of bending or shaping a blank by rotating an axis is called roller bending, isn’t it?

answer.

246. The advantage of rolling bending is its great versatility. When rolling sheet metal, it is usually necessary to add other processing devices to the rounding machine, isn’t it?

answer.

247. In order to remove the bent cylindrical workpiece, both ends of the upper shaft roller supporting part are movable and the workpiece can be removed, right?

Answer: No.

248. During the roller bending process, you should always use a template to check. It’s best not to roll the curvature too small, right?

Answer: No.

249. What are the methods of bending and forming?

Answer: There are pressure bending, pull bending, bending and manual bending, etc.

250. During the bending process, by adjusting the upper and lower rollers, the blank can be bent to any curvature less than the curvature of the upper roller.

Answer: Simply adjust the relative position of the upper and lower rollers.

251. What are the two categories of rounding machines?

Answer: There are two categories: discrete and horizontal.

252. Horizontal rounding machines are divided into three-axis and four-axis. What are the two types of three axes?

Answer: There are two types: symmetrical type and asymmetrical type.

253. What is the shape of the cores of the three rollers of the three-axis symmetrical rounding machine?

Answer: It forms an isosceles triangle.

254. When material is rolled into a cylinder, the distance between the rollers must be adjusted to keep the centers of the rollers aligned with each other.

Answer: Be sure to keep the centers of the rolls parallel to each other or the piece will become tapered.

255. When the pipe is bent, what force is exerted on the material outside the neutral layer to thin the pipe wall? How much force is exerted on the material inside to make the pipe wall thicker?

Answer: The action of tensile stress makes the tube wall thinner; the action of compressive stress makes the tube wall thicker.

256. When the pipe is bent, because the cross section is circular and the rigidity is insufficient, what can easily happen when it is bent in the free state?

Answer: It is prone to flattening and warping.

257. What are the main processes of manual pipe bending?

Answer: The main processes include sand loading, marking, heating and folding.

258. When bending a crimped pipe blank, where should the pipe joint be located?

Answer: Central layer.

259. What tests should be carried out on the elbow part of the elbow pipe to check whether there are any phenomena?

Answer: Be sure to perform a pressure test to check for a leak.

260. How to eliminate the straight start of the three-roller asymmetric rounding machine?

Answer: With the three-axis asymmetric rounding machine, the rolled part has only straight ends at the beginning. As long as the part is turned over and rolled again after the first rolling, the straight ends at both ends can be eliminated.

261. What is the anti-deformation method?

Answer: Before the tube blank enters the bending deformation zone, a certain deformation is given in advance to make the outside of the tube wall swell to compensate or reduce the deformation of the tube. cross section during folding.

262. When assembling T-shaped beams in small batches or single pieces, what assembly method is typically used?

Answer: Use the marking set.

263. When assembling T-beams and I-beams, which joint is typically used to further increase assembly speed?

Answer: Use a mold assembly.

264. The longitudinal shrinkage of a weld decreases as the length of the weld increases, correct?

Answer: No.

265. The guardrail of the overhead crane is a truss structure, and its upper camber is the same as the main beam, right?

answer.

266. Box girders, bridges and frames must also have a certain camber, and the camber in the middle must be greater than the allowable deflection of the beam, right?

Answer: No.

267. Due to the self-weight of the bridge and the influence of welding deformation, the prefabricated camber of the box girder web should be greater than the camber of the main girder, right?

answer.

268. When the steel plate is thin and the weld is in the middle of the steel plate, what type of deformation often occurs after welding?

Answer: Wave deformation occurs.

269. When the weldment itself cannot overcome the function of the weld, will it cause deformation of the welded body?

Answer: When the weldment itself cannot overcome weld shrinkage, it will cause deformation of the weld body.

270. What are the methods to prevent and reduce welding deformation?

Answer: There are anti-deformation method, rigid fixing method and hammer welding method.

271. What do we call parallel lines on this projection plane? What is the property of the projection of this line?

Answer: When a straight line is parallel to the projection surface, it is called a line parallel to the projection surface. The projection of this line is realistic.

272. All sheet metal has a thickness, and the thickness of the sheet affects the shape and size of what designs are made?

Answer: This impacts the shape and size of the developed diagram.

273. How are the surfaces of spheres, rings and spiral components curved?

Answer: Its surfaces are all non-developable surfaces.

274. What expansion method is generally used for expanding prisms and cylinders?

Answer: Generally, parallel line expansion method is used.

275. If a conical tube and a cylindrical tube intersect at right angles, what method is often used to find the line of intersection?

Answer: The auxiliary plane method is often used to obtain it.

276. Which method is most commonly used to find the true length of a curve?

Answer: Use the expansion method more often.

277. When a friction press is overloaded, it will only cause slippage between what, but will not damage the machine parts?

Answer: It will only cause slippage between the flywheel and the friction plate, but will not damage the machine parts.

278. The stroke of the sliding block of an open crank press can be adjusted by changing what and what?

Answer: It can be adjusted by changing the eccentric sleeve on the upper part of the connecting rod and the center distance of the main shaft.

279. In drawing and extrusion processes, what are the most stringent requirements for materials due to the space between the dies?

Answer: Material thickness tolerance requirements are strict.

280. What are the three stages of the sheet metal separation process during cutting?

Answer: Elastic deformation, plastic deformation and separation by cracking.

281. The higher the stretching coefficient, the greater the degree of stretching deformation of the material?

Answer: The smaller the stretching coefficient, the greater the degree of stretching deformation of the material.

282. What is cold stamping?

Answer: Stamping processing carried out at room temperature is called cold stamping.

283. What is a composite process?

Answer: The combination of two or more basic processes and their completion in a single press pass is called a composite process.

284. What is a simple cutting die?

Answer: With a single press stroke, a single punching process can be carried out.

285. What is a composite punch die?

Answer: With one press stroke, the punching die can perform multiple processes at the same time.

286. How to explain the punching force correction coefficient Kp?

Answer: When calculating the punching force, factors such as mold cutting edge wear, mold spacing and mechanical properties of the material are taken into account, and the safety factor chosen is, in general, Kp equal to 13.

287. What is oblique edge removal?

Answer: Punching inclined edges is a method to reduce punching force. That is, the edge of the die is inclined at a certain angle to the blank, so that the contact between the edge of the die and the blank is gradual during punching, making the load uniform and stable.

288. What is step punching?

Answer: Step punching is a method to reduce punching force. When punching multiple holes at the same time, the punch takes on a stepped shape with different heights relative to the blank, which can effectively disperse the punching force during punching.

289. What is the difference between an open crank press and a closed crank press?

Answer: Structurally, the bed of an open crank press has a C-shaped structure, and the connecting rod converts the rotational motion of the eccentric chuck into the reciprocating up and down motion of the slider. The closed press bed has a frame-like structure, and the eccentric shaft is replaced by a crank.

290. What are the characteristics of open crank press and closed crank press?

Answer: The C-shaped bed of the open crank press is open on three sides, which is especially suitable for stamping the edges of large sheets. However, this form of bed structure itself has low rigidity and can therefore support lower loads. The frame structure of the closed crankshaft press is limited by the columns, the workbench area is limited, and the operating space is small. Therefore, there are certain restrictions on the peripheral dimensions of stamping parts. The frame-like structure of the bed has good rigidity, and the load it supports is large and uniform.

291. What are the factors that affect the stamping of materials?

Answer: Elasticity, plasticity, hardness, surface quality of the material and thickness tolerance of the material.

292. What effect does die set have on cutting quality?

Answer: If the gap between the convex and concave dies is too small, the cracks in the material near the cutting edge of the convex die will be shifted outward. In this way, part of the material between the upper and lower grooves will be sheared. a second time as the cutting progresses, affecting the quality of the cross section. When the gap is too large, the cracks in the material near the edge of the punch are shifted inward some distance and the material is stretched significantly. Burrs, sag angles and slopes on the edge of the material will also affect the cross. cutting quality of the shutter parts. In addition, if the gap is too small or too large, it will have a certain impact on the dimensional gap of the shutter parts.

293. What are the factors that affect the minimum bending radius of materials?

Answer: (1) The mechanical properties and heat treatment state of the material; (2) The bending angle of the part (3) The geometry and size of the material (4) The bending direction; such as material thickness, surface and side quality etc.

294. How is the neutral layer of a material defined when folding?

Answer: During the process of bending the material, the outer layer is stretched and the inner layer is compressed. There should be a transition layer on the cross section that is neither stretched nor compressed. The stress is almost equal to zero. is called neutral layer of material.

295. When correcting components consisting of multiple beams and columns, what assembly relationships should be fully considered?

Answer: Fully consider the connection relationship between beams and columns.

296. When correcting the deformation of thin sheets in steel structures, what should be ensured to meet the requirements?

Answer: It is necessary to ensure that all frame types meet the requirements before thin plate correction can be considered.

297. What is the heating point of the heating point linked to the plate? How far apart are the heating points?

Answer: The heating point of spot heating is related to the thickness of the plate. The distance between heating points must be uniform and constant.

298. What is longitudinal shrinkage?

Answer: A form of removal of the weld and metal near the weld. Shrinkage along the length of the weld is called longitudinal shrinkage.

299. What is lateral withdrawal?

Answer: One form of shrinkage of the weld and metal near the weld refers to shrinkage perpendicular to the length of the weld, called lateral shrinkage.

300. How are internal stresses generated in steel structural parts?

Answer: The welding process is an uneven heating and cooling process for riveted welded structures, which is the main cause of internal stress in riveted welded structural parts. Additionally, each part of the steel structure may have residual stresses in the raw state or after being made into parts. After being assembled and welded into a whole, these residual stresses can accumulate into new internal stresses in the component.

301. Why do some steel structural parts need to undergo stress relief treatment after welding?

Answer: After welding, some steel structural parts have no obvious welding deformation due to their good rigidity, but the welding stress is quite large. After the steel structure is used for a while, it may be released for one reason or another. deformation to the point of destruction. Therefore, for some important steel structures, such as high pressure vessels, hazardous fluid containers and boilers, various methods are used for stress relief treatment after welding, to prevent internal stress in the steel structure do not damage the components.

302. What are the factors that affect the welding deformation of steel structural parts?

Answer: Factors that affect welding deformation of structural steel parts include design and process. The design aspect refers to the rationality of the structural design, the location of welds and the shape of weld grooves, etc. The process aspect refers to the reasonable regulations of the welding process, the sequence of assembly and welding, the use of various anti-deformation and anti-warping methods, and the stress relief measures taken.

303. How to understand the intrinsic relationship between steel structural parts?

Answer: Steel structural parts are a variety of parts connected together by various methods such as welding, riveting or bolting. These pieces are interconnected and bound together to form an organic whole.

304. What is the key to correcting the deformation of steel structural parts?

Answer: (1) Analyze the causes of component deformation and find out whether the deformation is caused by external force or internal stress.

(2) Analyze the internal relationship of the components and clarify the mutual constraints of different parts.

(3) Choose the correct correction site and resolve the main contradiction first, then the secondary contradictions.

(4) It is necessary to understand and master the properties of the steel used in the components to avoid breakage, cracking or rebound of the part during correction.

(5) Determine the correction method according to the actual situation and the order in which multiple methods are used together.

305. Which method can be used only to correct the deformation of thin plates in structural steel parts?

Answer: For the deformation of thin plates in steel structures, local heating (and spot heating) can only be used to correct it.

306. What aspects should be paid attention to when correcting the deformation of thin plates by point heating?

Answer: (1) The heating temperature should be appropriate, which should be enough to cause plastic deformation of steel, but not too high, generally 650℃~800℃.

(2) The size of the heating point and the distance between the points should be appropriate. Generally speaking, depending on the thickness of the board, the layout should be uniform, generally plum blossom shape.

(3) Rapid water cooling and wooden hammer hammering are to accelerate the removal of the fiber group from the steel plate.

(4) Do not tip the gas welding torch during heating. The small flames should be vertical to the steel plate. Do not have too many heating points to avoid increasing excessive internal stresses.

307. What are the characteristics of deformation of frame components?

Answer: There are many parts in the frame components, which have strong mutual stresses in the structure, and the mutual influence of deformation is large.

308. When the billet is rolled and folded by the simmering machine, it is usually heated, isn’t it?

Answer: No.

309. When heating and bending, to what extent should the material be heated? And why not simultaneous heating? How does it work? What will the final temperature be?

Answer: The material should be heated to 950℃~1100℃. At the same time, the heating should be uniform and the final temperature should not be lower than 700°C.

310. What are the possible defects that can occur when bending a cylinder?

Answer: Defects that can occur when rolling and bending a cylinder include distortion, uneven curvature, excessive curvature, and a drum shape in the middle.

311. When rolling a cone, as long as the center of the upper shaft is adjusted to which position and the axis of the roller always coincides with the generator of the sector-shaped blank, can it be rolled cone-shaped?

Answer: Adjust it to an inclined position.

312. When rolling a cone, which edge of the blank should increase friction? Make what moves slower than what moves faster?

Answer: Increase the friction of the small opening of the blank so that the speed of the small opening is less than the speed of the large opening.

313. There are many types of shafts for cored curved pipes, including round head type, pointed head type, hook type and what type?

Answer: And one-way joint type, universal type, etc.

314. Coreless pipe bending does not use a mandrel. What process is used on the pipe bender to control pipe deformation?

Answer: The anti-deformation process is used on the pipe bender to control the deformation of the bent pipe section.

315. When the radius of curvature of the elbow is greater than how many times the diameter, coreless elbows are generally used?

Answer: More than 1.5 times.

316. Extrusion bending uses the plasticity of the metal to press the pipe blank into the mold with what type of mold at normal temperature to form a pipe elbow?

Answer: Press the pipe blank into the bending mold to form a pipe elbow.

317. When extruding and bending a pipe, in addition to the moment of the bending force, what other forces act in the direction opposite to the axial force?

Answer: It is also affected by axial and friction forces in the direction opposite to the axial force.

318. Briefly describe the process of rolling and bending blanks with a rounding machine?

Answer: In roller bending, the blank is placed between the upper and lower rollers of the rounding machine. Due to the rotation of the rollers and the friction between the upper and lower rollers and the blank, the blank moves, thus forming bends continuously.

319. What are the advantages of the four-axis rounding machine?

Answer: The advantage of the four-axis rounding machine is that both ends of the sheet can be rolled, eliminating straight ends at both ends. Compared with the three-axis rounding machine, the process is simplified, the workload is reduced and. production efficiency is improved.

320. What are the methods for rolling a cone?

Answer: It can be divided into area rolling method, rectangular feeding method, rotary feeding method and small mouth deceleration method, etc.

321. How to reduce the ovality of the cross section when bending pipes?

Answer: When bending pipes, in order to reduce the ovality of the cross section, during the production process, loads are often added to the pipes, or rollers with tapered grooves are used to press the outside of the pipes, or chucks are used. to penetrate inside the pipes. bending method.

322. What are the advantages of spoon chucks?

Answer: The bearing surface between the spoon-type chuck and the outer wall is large, and the anti-flattening effect is better than that of the pointed type. The surface is not easy to wrinkle when the pipe is bent. the chuck is also more convenient to manufacture, so it is widely used.

323. What are the advantages of coreless bent pipes compared to cored bent pipes?

Answer: (1) Reduce a lot of core preparation and other work before bending, thereby improving production efficiency.

(2) Avoid mandrel manufacturing and reduce costs.

(3) No lubrication is required inside the pipe, saving lubricant and oil injection processes.

(4) The quality of the elbow pipe is ensured.

(5) There is no friction between the mandrel and the pipe wall, which reduces the torque when bending the pipe, thereby extending the life of the pipe bender.

324. How is the mechanical transmission tube bender driven?

Answer: The mechanical transmission pipe bending machine is driven by an electric motor through a transmission shaft, a reduction mechanism and a worm gear to drive the pipe bending die rotating.

325. When assembling the ring joint of the connected cylinders on the roller frame, the side distance and height position of each pair of rollers cannot be the same, so the cylinders can be concentric when l assembly, right?

Answer: No.

326. If there is a deviation in the diameter of the two cylinder sections, the cylinder section with the larger diameter should be raised during assembly to make the two cylinder sections concentric, right ?

Answer: No.

327. The higher the linear expansion coefficient of the weldment material, the greater the shrinkage of the weld bead after welding, right?

answer.

328. The shrinkage after welding of carbon steel is higher than that of stainless steel and aluminum, right?

Answer: No.

329. When using hammer welding method to avoid distortion of multi-layer welding, hammering should be applied on the first and last layers, right?

Answer: No.

330. Rigid fastening method will cause large internal stresses in the weld area, so this method is suitable for medium carbon steel and alloy steel, right?

Answer: No.

331. What is often used to join the longitudinal seams of the cylinder to improve the efficiency of the assembly?

Answer: Lever and screw tensioner are often used to improve efficiency.

332. What is often used to adjust the ovality of thin-walled cylinders?

Answer: Use a radial lifter.

333. When thin cylindrical sections are butted together, how can they be joined together to ensure that the assembly does not bend?

Answer: Using a roller type roller frame for assembly can ensure that the entire unit does not bend.

334. When installing vertical butt joints with cylindrical ring joints, what type of clamping and alignment ring joints can be used to achieve better results and at the same time achieve the required gap?

Answer: Using wedge pliers to tighten and align the ring joints can achieve better results and achieve the required clearance.

335. What positioning should be used when vertically installing overlapping cylindrical ring joints? What is the final clamp?

Answer: Use a retaining iron for positioning. Finally, tighten it with tapered shims.

336. What does a rivet gun mainly consist of?

Answer: It mainly consists of a handle, a gun body, a trigger and a pipe joint.

337. Before cold riveting, in order to eliminate hardening and improve the plasticity of the material, how should rivets be treated?

Answer: Annealing is necessary.

338. What are blind rivets made of and what do they consist of?

Answer: It consists of hollow rivets and mandrels.

339. What happens in the weld zone after the weld cools? What force is generated in the welded body?

Answer: Once the weld bead cools, shrinkage occurs in the weld bead area, causing internal stress in the weld body.

340. When multilayer welding, the first layer causes the greatest shrinkage. What percentage of the shrinkage of the second layer corresponds to the shrinkage of the first layer? The third layer is about several tens of percent of the first layer?

Answer: (1) Twenty percent; (2) Five to ten percent.

341. What is the general camber of the main girder of an overhead crane?

Answer: One thousandth.

342. What three parts does an overhead crane consist of?

Answer: Bridge frame, operating mechanism and carrier trolley.

343. What is the main beam of the box structure made of?

Answer: It consists of upper cover plate, lower cover plate, web plate and long and short rib plates.

344. For the web area of ​​the main beam of the box row structure, what is the maximum allowable wave peak value for the pressure zone within a radius of one meter in length? What is the tension zone?

Answer: It is 0.7 t for the compression zone and 1.2 t for the tension zone.

345. What tolerance is required when cutting the webs of box girders? How far from the center can there be a joint?

Answer: A margin of 0.5/1000 is required and there must be no joints two meters from the center.

346. There are different types and shapes of steel roof trusses depending on their uses and needs. What are the general types of roof trusses?

Answer: There are triangular, trapezoidal, spherical and mesh roof trusses, etc.

347. What is the general height of a triangular roof truss in relation to its span? How tall is a trapezoidal roof truss relative to its span?

Answer: Triangular roof trusses measure between a quarter and a fifth. Ladder roof trusses measure one-sixth to one-twelfth.

348. What method is commonly used to assemble steel roof trusses?

Answer: The profiling method is mainly used for assembly.

349. What is cold riveting?

Answer: Riveting rivets at room temperature is called cold riveting.

350. What is riveting?

Answer: Blind riveting is another method of cold riveting. Using manual or compressed air as energy, special tools are used to rivet rivets and riveted parts.

351. What is hot riveting?

Answer: Riveting after the rivets are heated is called hot riveting.

352. What is the anti-deformation method?

Answer: Analyze the direction and size of the deformation that may occur after welding. Before welding, the welded parts should be deformed in the same size and opposite direction to compensate or compensate for the deformation after welding, so as to avoid post-welding. deformation of the weld. For this purpose, this method is called anti-deformation method.

353. What is the rigid fixation method?

Answer: The method of using joining devices or temporary supports to fix the mutual positions of the welded parts to prevent deformation after welding is called rigid fixing method.

354. The layout drawing is a drawing drawn on the basis of the construction drawing, right?

Answer: No.

355. In addition to flat surfaces, there are also cylindrical and conical surfaces that can be developed, right?

answer.

356. All the drawing lines on the developed diagram are real long lines corresponding to the corresponding parts on the component surface, right?

answer.

357. If one of the projections of a line segment in the three-dimensional projection has accumulation properties, then the other two projections must be authentic, that is, reflect the actual length of the line segment, isn’t it?

Answer: No.

358. If both projections of a line segment are perpendicular to the projection axis between them, then the third projection must reflect the actual length of the line segment, right?

Answer: No.

359. The projection of a straight line is always a straight line, there is no other way, is there?

Answer: No.

360. Generally, the actual length of a position straight line in a three-dimensional view sometimes reflects the actual length, and sometimes it does not reflect the actual length, right?

answer.

361. For the actual length of a line in a general position, it is better to use the rotation method, right?

Answer: No.

362. Methods for finding the actual length of a line segment include the parallel line method, the triangle method, and the radial line method, right?

Answer: No.

363. In the production of riveting or sheet metal work, the right triangle method, rotation method, surface change method and snood method are commonly used to draw developed diagrams, isn’t it ?

answer.

364. When using the triangle method to develop a shape, the key is to find the actual length of each first line, right?

Answer: No.

365. Plane curves reflect the actual length in three views, right?

Answer: No.

366. Prisms, cylinders and cylindrical surfaces can all be enlarged by the parallel line method, right?

answer.

367. The triangular expansion method is applicable to expanding shapes where the main lines on the surface of all components intersect at a point, right?

Answer: No.

368. When using the auxiliary surface method to find lines of intersection, the axes of the rotating body must be parallel and reflect the actual length, right?

Answer: No.

369. What presses are commonly used by riveters?

Answer: There are hydraulic presses and pneumatic presses.

370. What effect does the final riveting temperature have on riveting?

Answer: Too much tension will reduce the initial stress of the nail shank; Too little pressure will cause the rivet to become blue brittle.

371. What is the function of the shank of a drill bit?

Answer: The torque and axial force required for tightening and transmitting drill holes.

372. What types of hammers are commonly used by riveters?

Answer: There are hand hammers, sledgehammers and type hammers.

373. What types of scissors are commonly used by riveters?

Answer: There are two categories: flat scissors and narrow scissors.

374. What is steel?

Answer: An iron-carbon alloy with a carbon content of less than 2.11% is called steel.

375. What is high carbon steel?

Answer: Steel with carbon content above 0.6% is called high carbon steel.

376. How many categories can steel be divided into based on its uses?

Answer: It can be divided into structural steel, tool steel and special purpose steel.

377. How many categories can steel be divided into based on the shape of its end face?

Answer: It can be divided into plates, pipes, profiles and wires.

378. What are the two basic methods for correcting warping in steel?

Answer: There is a cold work correction and a heating correction.

379. What is a montage montage?

Answer: It is the processing equipment used to apply external force to parts during the assembly process to ensure reliable positioning.

380. How many basic methods are there for correcting cold work?

Answer: There is manual correction and mechanical correction.

381. What are the heating correction categories?

Answer: It is divided into full heating correction and partial heating correction.

382. What are the forms of the local heating zone of heating correction?

Answer: There are three types: dotted, linear and triangular.

383. What are the types of deformation of steel angles?

Answer: There are three types: torsion, bending and angular deformation.

384. What are the deformations of channel steel?

Answer: There is local twisting, bending and deformation of the wing plate.

385. What is cold correction?

Answer: The correction carried out at room temperature is called cold correction.

386. What are the stages of separation?

Answer: It includes three processes: cutting, punching and cutting.

387. What is stamping?

Answer: The process of separating or forming sheet metal into parts.

388. What are the advantages of stamping?

Answer: Good product quality, high productivity, material saving, cost reduction and easy automation.

389. What is bend forming?

Answer: A processing method that bends the blank into the required shape.

390. What are the three basic forms of riveting?

Answer: Butt joint, lap joint and corner joint.

391. What is riveting?

Answer: Rivets are used to join two or more components into a whole.

392. How many types of rivets are commonly used?

Answer: There are half round heads, countersunk heads, half countersunk heads, flat heads, flat cone heads, oblate heads and flat heads.

393. What are the types of riveting?

Answer: There are solid rivets and tight rivets.

394. What is assembly?

Answer: It is an overproportion that combines various parts into components according to certain technical conditions.

395. What are the three elements of the assembly?

Answer: Positioning, support and tightening.

396. What are the methods of connecting metal structures?

Answer: There are hybrid connections by welding, riveting, bolting and riveting.

397. What tools are commonly used for collection prevention?

Answer: Pink thread, stone pen, drawing needle, ruler, sample punch and hand hammer.

398. What are the main methods for finding intersecting lines?

Answer: There are the primary line method, the auxiliary plane method and the spherical method.

399. What are the methods to find the real length of a line segment?

Answer: Rotation method, right triangle method, area change method and branching method.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

CNC Knowledge: How big is the technical gap between medium and slow wire processing?

Great Light CNC Machining Services 11/01/2025 13:34

CNC wire EDM processing includes fast wire cutting and slow wire cutting, which are widely used in the mold manufacturing industry. What is the current development status of the processing efficiency, cutting precision and surface quality of these two technologies?

▌ Development status of rapid yarn processing technology

As the name suggests, rapid wire processing gets its name from the high-speed unwinding of the wire electrode during the cutting process. The rapid wire processing machine tool is the original electrical processing machine tool in my country. After decades of continuous improvement and development, it has now become an important processing method in the manufacturing industry. It can meet the requirements of mid-to-low-end mold processing and other complex parts manufacturing, and occupies considerable weight in the mid-to-low-end market.

The biggest advantage of high-speed wire processing machine tools is that they have a good performance-price ratio. Due to its practicality and economical nature, it has a large domestic market. Traditional rapid wire processing uses a single cutting process, with a processing efficiency of about 40㎜²/min, a surface roughness of about Ra3.0μm, obvious lines on the surface, and a processing precision of ‘approximately 0.02㎜.

In order to improve the processing quality, rapid wire processing machine tool manufacturers have improved the relevant components of machine tools referring to the multiple cutting process, and the so-called “machine tools of medium wire processing” have appeared. A large number of process technologies such as CNC machine tool precision, pulse feeding, wire moving system and process database have been significantly improved. The processing precision is improved and the surface quality is improved.

The current technical indicators of wire processing machine tools: the efficiency of one cut is 180㎜²/min, the surface roughness after multiple cuts is Ra≤1.0μm, the average efficiency at this time is of 50㎜²/min and the treated product the surface is shiny. There are no obvious cutting scratches, the processing precision is 0.01㎜, and the loss of the electrode wire is ≤01㎜/200,000㎜². These performance indicators seem relatively good, but it should be noted that achieving these indicators requires ensuring all aspects. Once there are deviations, such as changes in the concentration of the working fluid and loss of the electrode wire, it will affect the. stability of processing quality.

Typical manufacturers of wire cutting machine tools in production include Suzhou Sanguang, Suzhou Hanqi, Shanghai Tello, Beijing Ande, Suzhou Baoma, Suzhou New Spark, Shanghai Dajia, etc.

▌ Development status of slow yarn processing technology

With the continuous improvement of manufacturing accuracy and surface quality requirements for precision, complex and long-life stamping molds, rapid wire processing technology can no longer adapt to mold manufacturing requirements precision. This status quo favored the rapid development of slow wire. processing technology and its various process indicators It has reached a very high level and is irreplaceable by other processing technologies.

1. Development status of slow yarn processing technology

(1) Improved processing precision

Multi-cutting technology is the fundamental way to improve the precision and surface quality of slow wire cutting. Generally, it is formed by one cut, two cuts improve the precision, and three or more cuts improve the surface quality.

Due to the hysteresis of the electrode wire when cutting corners, the corners will collapse. In order to improve the corner cutting accuracy, more dynamic corner processing strategies are adopted. For example: automatically change the treatment speed, automatically adjust the water pressure, control the treatment energy, etc.

The high-precision finishing circuit adopted by advanced slow wire processing machine tools is an effective technology for improving the straightness of processed parts, which greatly improves the processing precision of thick parts to process small threads, narrow slits, narrow and fine grooves; For microfinishing parts, low tip speed CNC wire EDM machines can use 0.02-0.03mm electrode wire for cutting.

In order to ensure high precision processing, mechanical precision, pulse power precision and servo control precision of the machine tool (including control of mechanical movement, pulse parameters, wire moving system and working fluid system) have reached an extremely high level. A water temperature cooling device is used to make the internal temperature of the machine tool the same as the water temperature, thereby reducing the thermal deformation of the machine tool; A closed-loop digital AC (DC) servo control system is used to ensure excellent dynamics. high performance and positioning accuracy, and the processing accuracy can be controlled within a few microns. In the range, precise positioning can achieve control equivalent to 0.1μm; immersion treatment is used to reduce the thermal deformation of the workpiece servo motor, closed-loop electrode wire; tension control; the voltage modulated tool setting power supply is used to achieve high precision tool setting, and the tool setting accuracy can reach 0.002. ㎜, no damage to the piece, wet or dry.

(2) Surface quality is improving day by day

Advanced slow wire processing machine tools use non-electrolysis pulse power supply with average voltage of zero, and the damage of electrolysis has been reduced to a minimum. In addition, due to the improvement of pulse supply, a high peak value and narrow pulse width (microsecond level) are generally used. Most materials are released in the gas phase, which absorbs a lot of heat. the part cannot rise and the phenomenon of cracking is considerably reduced; not only is the processing efficiency high, but the surface quality is also greatly improved. Using an electrolytic energy source for wire EDM processing can control the surface deterioration layer below 2 μm. The wear resistance of the carbide die cutting edge is no different from that of grinding, and is even better than mechanical grinding. More and more parts are processed by “cutting instead of grinding”.

(3) Improvement of treatment efficiency

Due to the development of nanosecond large size peak current pulse power supply technology and detection, control and anti-interference technology, the processing efficiency of machines- Slow wire processing tools are also constantly improving. machine tools can reach 500㎜²/min. The processing efficiency of larger thickness parts presents practical technological improvements. For example, when cutting a 300mm thick workpiece, the processing efficiency can reach 170㎜²/min. For processing parts of varying thicknesses, the maximum processing efficiency in this state can be achieved by automatically detecting the thickness of the part and automatically adjusting the processing parameters to avoid wire breakage.

In addition, the rapid automatic threading technology introduced by advanced slow thread processing machine tools has an automatic threading time of <15s, which improves the efficiency of processing operations; the introduced double wire automatic exchange technology can automatically use 0.20-0.02mm; electrode wire for double wire threading. Use thick wire for the first cut, generally with a wire diameter of 0.25mm, to improve processing efficiency and enable coreless cutting; then use a fine wire for cutting, usually using 0.10mm filament, to cut small round corners, and improved precision can save 30-50% of the overall cutting time.

(4) Development of automation, intelligence and informatization

During the processing process, in order to reduce human intervention and ensure that the expected process indicators are achieved, the automation, intelligence and computerization of slow yarn processing have achieved corresponding development.

The complete process expert system of the slow wire processing machine tool provides a complete set of parameters according to the processing requirements. It not only includes commonly used electrode wire brands and corresponding workpiece materials, but also provides processing parameters for special materials such as PCD and PCBN. It can be based on whether the upper and lower nozzles are in contact with the workpiece and how far apart they are. are, and whether windbreak finishes or open surface repairs, which should be preferred among precision, surface roughness and efficiency? Strategies are used to generate respective specifications; The discharge expert system handles random factors during cutting and uses adaptive control during the processing process in situations such as cutting, cutting, cross-section changes, center cutting, near edge cutting , high-speed cutting of large sections, etc. Automated strategies and control functions enable stable and efficient processing of continuous yarns.

The automatic hole-free detection function is also very convenient. During automatic skip processing, if the pre-hole is forgotten or the hole position is shifted, the machine tool will automatically move to the next pre-hole, preventing the machine from stopping during unattended operation . Processing when a short circuit occurs after threading, the position of the short circuit can be automatically searched and eliminated, which improves the reliability of continuous operation without a driver.

The CNC system of the machine tool is equipped with a standardized mechanical interface to form an intelligent manufacturing system. Thanks to the manipulator of the 3R system or the EROWA system, the automatic exchange of parts (pallets) can be easily achieved with the expert system. and automatic electrode wire exchange technology, it can automatically complete all treatment processes.

2. The technical level of different grades of slow wire processing machine tools

Slow wire processing machine tools can be divided into four categories: high-end, high-end, mid-range and entry-level. Typical manufacturers that produce slow wire machine tools include Swiss GF Machining Solutions (formerly AgieCharmilles), Japanese Makino, Japanese Mitsubishi, Japanese Sodick, Japanese Western, Japanese Frank, etc.

(1) Best slow wire processing machine tools

This type of slow wire processing machine tool represents the current highest level and is mainly manufactured in Switzerland and Japan. The processing accuracy of this type of machine tool can be guaranteed within ±0.002mm, the maximum processing efficiency can reach 400~500㎜²/min, and the surface roughness can reach Ra0.05μm. It has perfect processing surface quality. with almost no deterioration layer on the surface, and Φ0.02mm electrode wire is used for micro-finishing. Most main machines have a heat balance system, and some machine tools use oil cutting processing. This type of machine tool has complete functions and a high degree of automation. It can directly complete the precision processing of molds. The service life of processed molds has reached the level of mechanical grinding.

(2) High-end slow wire processing machine tools

This type of machine tool is mainly produced by Swiss and Japanese companies. It has an automatic threading function, a resistance-free anti-electrolysis power supply and a global thermal constant system. It can use Φ0.07㎜ electrode wire for cutting. , with an accuracy of about ±0.003㎜, and the highest processing. The efficiency can reach more than 300㎜²/min and the surface roughness can reach Ra<0.2μm. Its function is to detect changes in the cross section of the workpiece. timely and optimizing the discharge power in real time. This type of machine tool is also widely used for processing precision stamping dies.

(3) Mid-range slow wire processing machine tools

This level of machine tools is usually produced by Swiss and Japanese companies in manufacturing plants in China. The technical level of some Taiwanese machines can also reach this level. Their configuration and performance meet the requirements of most domestic precision wire cutting processes. Generally, a resistance-free anti-electrolysis power supply is used, which has the functions of submerged processing and taper cutting. The maximum practical processing efficiency is 150~200㎜²/min, the best surface roughness reaches Ra < 0.4μm, and the cutting precision can reach ±0.005㎜. Generally, electrode wires of Φ0.1㎜ and above are used for cutting. and are equipped with a collision protection system that can prevent damage caused by programming errors or misuse, and are equipped or optional with an automatic wire threading mechanism.

(4) Entry-level slow wire processing machine tools

This type of machine tool is generally a Taiwanese machine tool or a machine tool independently developed and produced in China. Its configuration and performance meet the processing requirements of ordinary household molds and parts. Generally, the process of cutting one and cutting one, cutting one and cutting two is often used, which can stably achieve a surface finish of about Ra0.8μm and a processing accuracy of ±0.008mm. Most of them can only use electrode wires. 0.15mm and above for cutting and microstructure of the processed surface, there is a certain gap between corners and advanced machine tools.

In general, compared with fast wire processing machine tools, slow wire processing machine tools have very obvious advantages in processing efficiency, precision, surface quality, etc. Although machine tools for slow wire processing are more expensive, with the rapid development of the manufacturing industry, they will be more and more used in various processing fields.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

Photo WeChat_20240108143143.jpg

CNC Knowledge: Analysis of 6 usage factors of luminaire base plate

Great Light CNC Machining Services 11/01/2025 11:31

1. Types of bottom plates and bases

Vertical machining centers mainly use base plates. In addition to the basic base plate, horizontal machining centers also have single-sided bases, double-sided bases and four-sided bases.

In order to accommodate different part sizes, horizontal machining centers also use six- and eight-sided bases. In Figure 2, the areas marked in darker orange on the part are the surfaces that can be treated.

Photo WeChat_20240108143146.jpg

2. Types of bottom plates and base mounting surfaces

The installation methods of the bottom plate and base clamp mounting surface include T-shaped groove shape, bolt hole shape, reference hole shape, etc. In addition, in actual processing, in order to make the precision of the machining center and the precision of the fixture mounting surface as perfect as possible, there is also a form of self-processing.

Photo WeChat_20240108143149.jpg

Figure 3 Advantages and Disadvantages of Typical T-Shaped Slots, Bolt Holes, and Reference Holes

Each machine tool has its own characteristics, such as the inclination of the floor in the factory where the machine tool is located, the inclination of the spindle after many years of use, etc. The remaining material retained by the fixture mounting surface can be processed to accommodate the individuality of the machine tool, so that the fixture mounting surface can be customized with greater precision. There is also a form of disassembly and assembly of tools and parts outside the machine tool: rapid tool change.


3. Determine size and positioning method

When choosing a base plate or base, you should first confirm the size and positioning method in advance. The basic dimensions of horizontal machining centers are 400X400, 500X500, 630X630 and 800X800. Depending on the machine tool manufacturer, there are also sizes such as 300X300, 1000X1000, and special sizes such as 550X550 are also produced by machine tool manufacturers. The dimensions of vertical machining centers vary from one machine tool manufacturer to another, and there are no specific rules dictating the dimensions. Each machine tool manufacturer has its own prescribed dimensions for the machine tool bench. Please refer to the machine tool manual.

Photo WeChat_20240108143152.jpg

Figure 4

Positioning the bottom plate and base of a horizontal machining center generally uses bench blocks installed in the X and Y directions. The base plate and base are positioned by adjusting the bench block. The position of the workbench support block is generally set at the 0° and 270° orientations of the machine tool workbench. The position of the workbench support block also varies depending on the machine tool manufacturer. The center of the worktable of a vertical machining center is usually equipped with a keyway. Position the X direction of the base plate and base through the keyway, then position the Y direction of the base plate and base through the T-shaped slot.

However, not all T-shaped slots can be positioned precisely. Depending on the machine tool manufacturer, there are usually only one or two T-shaped slots with positioning function in the machine tool.


4. Confirm the maximum load of the machine tool

Firstly, confirm the maximum load capacity of the machine tool, and secondly, confirm the total weight of the workpiece, fixture, base plate and base. The total weight must not exceed the maximum load capacity of the machine tool. There are also designers who calculate the weight of the part, base plate and base, but forget to calculate the weight of the fixture, which cannot be ignored.

Photo WeChat_20240108143220.jpg

Figure 5

If the total weight exceeds the maximum load of the machine tool, you can choose to reduce the thickness of the base plate, reduce the thickness of the base mounting surface, or make the base hollow to reduce the total weight.


5. Confirm the base height and maximum rotation diameter

The maximum height and maximum rotating diameter of the machine should be confirmed in advance when selecting the base plate and base. Especially for horizontal machining centers, the maximum rotating diameter should be confirmed. Generally, when the base size is 400X400, the maximum rotation diameter is φ630. When the base size is 500X500, the maximum rotation diameter is φ800. The two sizes above are the most common sizes and there are no clear requirements for using a base of this size. When the collet is clamping the workpiece up and down, the top of the collet (the top of the bolt in the image below) should be within the maximum turning diameter.

Photo WeChat_20240108143224.jpg

Figure 6


six,Confirmation of extent and timing of treatment

Confirm in advance whether the machining range of the machine tool (the range of motion of the spindle) covers all parts of the workpiece that need to be processed. Especially when using a milling cutter to process the surface, when retracting the tool, it should be considered in advance when designing whether the spindle stroke can completely withdraw the tool from the workpiece . If tool retraction is not taken into account, it will be more. difficult to ensure surface accuracy. When the cutter leaves the workpiece, the minimum distance between the cutter and the workpiece must be greater than 10 mm, that is, the cutter must completely leave the workpiece area.

Photo WeChat_20240108143227.jpg

Figure 7

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

Image WeChat_20240109095951.png

CNC Knowledge: A Brief Discussion of Six Methods for Improving Efficiency in Metal Processing

Great Light CNC Machining Services 11/01/2025 10:30

01

Preface

The rapid development of China’s manufacturing industry has generated enormous economic benefits for our country and even the world. As market competition becomes more and more fierce, cost reduction and efficiency improvement have become problems that every enterprise must face. In order to effectively reduce costs and increase efficiency, it is necessary to analyze the composition of production costs. Production cost consists of three parts: direct materials, direct labor, and manufacturing overhead. Direct materials refer to labor objects in the production process, which are transformed into semi-finished products or finished products, and their use value then becomes another use value. Direct labor refers to human resources consumed in the production process, which can be calculated by wages, social expenditures, etc. Manufacturing expenses refer to facilities such as factories, machinery, vehicles and equipment, materials and auxiliary materials used in the production process. Part of their consumption is included in the cost through depreciation, and the other part through maintenance, fixed expenses, machine material. consumption and consumption of auxiliary materials are included in the price. This paper optimizes several tool usage methods to reduce tool consumption costs and improve processing efficiency, thereby achieving the effect of reducing machine tool usage costs.


02

Change the tool material to improve processing efficiency

Commonly used tool materials include: high speed steel, carbide, ceramic, CBN and PCD. CBN and PCD have higher hardness, highest wear resistance, and their materials are relatively brittle. High speed steel has the best toughness, but its hardness is very low and its wear resistance is poor.

High speed steel is a high carbon alloy steel. The main alloy elements are tungsten, chromium, molybdenum, cobalt, vanadium and aluminum, etc., and contain a large amount of carbides. High speed steel cutting tools have high toughness and relatively low hardness. The advantages are that they are cheap, have high plasticity and can process almost any material. They were the main materials used in early cutting tools. higher requirements for operators and require manual labor for sharpening, and the cutting speed that high speed steel materials can withstand is very low. For example, the workpiece material is 45 steel, the hardness is 250HBW, the cutting speed is 30-60m/min, and the cutting efficiency is low.

At present, the most commonly used tool material is coated carbide. The hardness and heat resistance of coated carbide tools are better than those of high speed steel tools. Can withstand higher cutting speed, cutting speed is 100~300m/min[1]。

Taking the outer circle of turning steel parts as an example, if carbide turning tools are used to replace high-speed steel turning tools, the cutting speed can be increased from 50m/min to 180m /min, and the efficiency is increased by more than 3 times, and carbide tools also have a higher service life. Carbide turning tools with replaceable blades do not need sharpening, simply replace the blade and the operator does not need sharpening skills.

Besides high speed steel and carbide cutting tools, there are also ceramic, CBN and PCD. These three materials have higher cutting speeds – above 1000 m/min, but their application range is limited. Ceramic and CBN are generally used to process cast iron parts and steel parts with high hardness above 50HRC. PCD is generally used to process aluminum, plastic, wood and carbide, but cannot process cast iron parts.[2]。

Taking aluminum alloy cutters as an example, the cutting speed of high speed steel cutters is 120~300m/min. The recommended cutting speed of Mapal brand carbide cutters made of HP615 material is 700 m/min, while cutters made of PCD material. can be used. The cutting speed is 1500 ~ 2000 m/min.


03

Effect of cutting parameters on tool life and production efficiency

In order to improve machining efficiency and tool life, it is necessary to determine whether the cutting parameters are reasonable and analyze the impact of each cutting parameter on tool life. and the effectiveness of the tool. The cutting parameters include cutting speed (linear speed), feed speed and reverse cutting amount, also known as the three cutting elements.

3.1 Cutting speed vc

The relationship between cutting speed vc and spindle speed is vc=πDn/1000, where D is the effective diameter of the tool/workpiece (unit: mm) and n is the speed of the machine tool ( unit: r/min). When the cutting speed is too high, flank wear increases and the surface quality of the part deteriorates. When the cutting speed is extremely high, the insert also undergoes plastic deformation. The influence curve of cutting speed on tool life is shown in Figure 1.

Figure 1 Curve of effect of cutting speed on tool life

3.2 Feed speed vf

The feed rate calculation formula is vf=fZZnn, fZ is the tool feed (the unit is mm/z), Zn is the number of effective cutting edges (the unit is l ‘unit), n is the speed of the machine tool (the unit is r/min). ). If the feed speed is too high, the chips will be uncontrolled and the quality of the machined surface will deteriorate. The cutting power is high and the chips will impact the tool or the machined surface. The influence curve of the feed speed on the tool life is shown in Figure 2.

Image WeChat_20240109095954.png

Figure 2 Effect curve of feed rate on tool life

3.3 The quantity of rear knife ap

The amount of undercut refers to the difference between the uncut surface and the cut surface. The influence curve of the amount of backcut on the tool life is shown in Figure 3.

Image WeChat_20240109095957.png

Figure 3 Influence curve of the amount of recoil on the tool life

Of the three cutting factors, cutting speed, feed rate, and degree of back engagement all impact tool life. The impact of back cut amount is the smallest, feed speed has a greater impact than back cut amount, and cutting speed has the greatest impact on blade life.

In order to obtain the highest tool life, the direction of optimization parameters is: maximize the back engagement to reduce the number of tool passes; maximize feed speed to shorten cutting time;

To improve roughing efficiency, you can start by optimizing the undercut amount, reducing the cutting speed, and improving the undercut amount. Tool life, increases feeding speed and ensures processing efficiency.

3.4 Application examples

The flange produced by an automobile parts processing plant is shown in Figure 4. The existing processing solution is inefficient, and various cutting parameters need to be optimized to improve tool life and production efficiency .

Image WeChat_20240109100000.png

Figure 4 Flange

Optimize the machining plane by increasing the amount of backcut, reducing tool paths and reducing cutting speed. Before optimization, the tool paths were numerous and chaotic, but after optimization, the tool paths were clear, as shown in Figures 5 and 6. The parameters before and after optimization are shown in the table 1. After optimization, the tool life increased from 15 parts to 31 parts.

Image WeChat_20240109100004.png

Figure 5 Front tool path optimization

Image WeChat_20240109100007.png

Figure 6 Optimized toolpath

Table 1 Parameters before and after optimization

Photo WeChat_20240109100013.jpg

The factor that measures the cutting performance of the blade is the cutting speed. The CNC system reads the spindle speed. Many programmers only consider speed when designing programs and ignore the diameter factor. However, in actual machining, the diameter factor also has an effect. greater impact. Taking turning as an example, when the workpiece diameter D is 50 mm and the machine tool speed n is 1000 rpm, the linear speed vc = 157 m/min. When the diameter of the workpiece D is 100 mm and the machine tool speed n is 1000 rpm, the linear speed vc = 314 m/min.

According to the tool sample, the cutting speed of 314 m/min is very high, close to the limit that the carbide blade can withstand. High cutting speed can accelerate the tool wear process and reduce tool life.

It can be seen from this that for the same machine tool speed, different workpiece diameters and tool cutting speeds, when the tool life is too low, you can check whether it is caused by high speed cut too high.


04

The influence of the scraper edge on cutting efficiency

The wiper blade has a tip angle consisting of 3-9 arcs with different radii, and the arc radius can reach more than 900mm. The relationship between tool tip fillet, feed quantity and surface quality is

Rmax＝fn²/8r（1）

Rmax (wiping edge) = Rmax/² (2)

In the formula, fn is the amount of feed (mm/r); r is the fillet radius of the tool tip (mm); Rmax is the height difference between the top and bottom of the cutting surface (mm).

This method is suitable for finishing turning or boring. The wiper tool itself does not have a fast forward function. However, according to the previous formula, it can be inferred that the characteristics of the wiper tool are as follows: When the processing parameters are the same, the surface quality of the wiper tool can be increased by 1 time when the surface quality is the same; , the advance speed of the wiper tool can be increased by 1 time.

When the same surface quality is required, higher feed rates can be used when using wiping tools.

Taking the processing of the end face of the outlet shell as an example of efficiency improvement, the workpiece material is QT500, and the surface roughness value Ra≤1.6μm is required. In order to improve the cycle time, a wiper blade was used in order to meet the same surface roughness requirements, the feed speed was increased from 0.36 mm/r to 0, 5mm/r. The measured surface roughness value Ra=1.33 μm. , and the blade life was the same. The different processing parameters using ordinary turning inserts and wiper inserts are shown in Table 2. The end face of the output shell after optimization is shown in Figure 7.

Table 2 Various processing parameters of ordinary turning inserts and wiper inserts

Image WeChat_20240109100016.png

Image WeChat_20240109100019.png

Figure 7 Optimized outlet shell end face


05

Effect of main deflection angle on cutting efficiency

Feed per tooth was mentioned in the previous brief introduction to the concept of feed rate. Some tool sample brands recommend hex maximum chip thickness as the cutting parameter instead of feed per tooth. Because what determines the amount of feed is the maximum chip thickness hex and the attack angle Kr of the tool. The conversion formula is hex=fzsinKr.

When the main deviation angle is 90°, fz=hex, the maximum chip thickness of the tool is the same as the feed per tooth. As the main deviation angle decreases, the feed rate can be increased.

Taking the square shoulder milling cutter (see Figure 8) as an example, the number of teeth ZN of the 90° square shoulder milling cutter is 5 flutes, n=1000r/min, hex=0.2mm, fz=0, 2mm/z, machine tool feed speed vf =0.2×5×1000=1000 (mm/min).

Image WeChat_20240109100022.png

a) Structure diagram of square shoulder milling cutter

Image WeChat_20240109100025.png

b) Physical objects

Figure 8 90° square shoulder milling cutter

Face milling cutter with 45° lead angle (see Figure 9) ZN has 5 flutes, n=1000r/min, hex=0.2mm, fz=hex/sin45°=0.282mm/z, then the speed of machine tool feed vf=0.282× 5×1000=1410 (mm/min).

Image WeChat_20240109100028.png

a) Structure diagram of the face milling cutter

Image WeChat_20240109100031.png

b) Physical objects

Figure 9 45° square shoulder milling cutter

Face milling cutter with an attack angle of 10° (see Figure 10) ZN has 5 edges, n=1000r/min, hex=0.2mm, fz= hex/sin10°=1.156mm/z, then the speed of machine tool feed vf=1.156×5×1000=5780 (mm/min).

Image WeChat_20240109100034.png

a) Signaling

Image WeChat_20240109100037.png

b) Physical objects

Figure 10 10° square shoulder milling cutter

In summary, at the same rotation speed and for the same type of blade, the smaller the main deflection angle, the higher the usable feed speed. It should be noted that the 90° square shoulder milling cutter mainly bears the radial force, and the axial force approaches zero, as the main deviation angle decreases, taking the main deviation angle milling cutter as an example of 10°, it mainly supports the axial force. The radial force is very weak. The smaller the main deviation angle, the greater the tendency to vibration and the higher the power consumed.


06

The influence of processing methods on cutting efficiency

The path of the cutting tool also has a significant impact on machining efficiency. For example, a recently popular dynamic milling method is an efficient trochoidal milling method with a large amount of back cut and a small cutting width. The difference with conventional trochoidal milling is that the dynamic milling process strictly adheres to constant chip thickness. metal removal rate. Since dynamic milling can ensure constant cutting force during tool cutting, the processing speed is fast and stable.

Taking the milling of the outer contour of the valve body as an example to illustrate the impact of processing methods on cutting efficiency, the part is made of stainless steel. The difficulty is that the length/diameter ratio of the tool reaches 4 times the diameter. which causes vibration during processing. The initial plan used square shoulder cutters with replaceable inserts, which resulted in significant cutting vibrations due to the high aspect ratio. Unable to process normally. Optimized to use carbide cutters, large back cutting capacity, small cutting width and dynamic milling method. The dynamic simulation of the milling tool path is shown in Figure 11 and the comparison parameters are shown in Table 3.

Image WeChat_20240109100040.png

Figure 11 Dynamic simulation of the milling tool path

Table 3 Comparison of parameters

Image WeChat_20240109100044.png


07

Improve machining efficiency with composite tools

For large volume products, composite tools are usually used to improve production efficiency, such as countersink drills, composite boring tools (see Figure 12), etc.

Image WeChat_20240109100047.png

Figure 12 Compound boring tool

Composite tools use a single tool to process multiple work steps, which improves processing efficiency and saves the tool changing time of multiple tools. Composite cutting tools also have many disadvantages. The biggest drawback is that they are not universal. Cutting tools are only designed for a certain workpiece and cannot be used universally with other workpieces.[3]。


08

Conclusion

This article offers six ways to optimize cutting tools, which can provide guidance for improving production efficiency and reducing costs. The tool optimization method should be flexible and should be applied on a practical basis. Before optimization, it is necessary to analyze the bottleneck process, optimize the tool in a targeted manner and grasp the key points to solve the problem according to the specific production conditions.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: Ultra-precision optical processing technology, equipment and prices

Great Light CNC Machining Services 11/01/2025 09:29

Optical processing technology mainly includes cutting, milling, fine grinding, polishing, edge grinding, bonding, coating and other process links.

Ultra-precise optical processing technology:

Ultra-precision optical processing technology is a key bottleneck technology for advanced equipment manufacturing, and nanometer precision is known as the “crown pearl” of ultra-precision optical processing technology. -precision.

The ultra-precision optical device manufacturing system includes ultra-precision optical processing, ultra-precision optical detection and ultra-precision optical surface processing.

Ultra-precision optical device processing technology canDivided into two categories: contact and contactless：

1. Among contact manufacturing technologies, the most representative method isCNC grinding and polishing (CCP), single point diamond cutting (SPDT) and magnetorheological polishing (MRF)technology.

2. Methods with significant application value in contactless manufacturingIncludes Abrasive Jet Polishing (FJP), Plasma Forming (PACE) and Ion Beam Polishing (IBF)and other technologies.

Ultra-precision optical processing equipment:

From the company prospectus we can learn:

Model and unit price of processing equipment:

Q22-Y MRF SYSTEM magnetorheological polishing machine, xxx million

ÅFiSy IFS300 ion beam polishing machine, xxx million

Polisher SPS60-2 SL2A, xxx million

20240109103911.png

Model and unit price of test equipment:

Spliced ​​Measuring Interferometer (MET5242-6, MET1173-6), xxx million

Helpline: 13522079385

There are also many different models of coating machines.

There are other equipment and prices:

serial number

Device name

original book value/million yuan

1

High Vacuum Coating Machine HELIOS 800 Generation II

xxxx

2

Leybold coating machine HELIOS 800

xxxx

3

Spliced ​​measuring interferometer (MET5242-6、MET1173-6）

xxx

4

Magnetorheological polishing machine (MRF Q22-Y SYSTEM）

xxx

5

Thin Film Optical Coating Machine/OTFC-1550

xxx

6

Thin Film Optical Coating Machine/OTFC-1550

xxx

7

Thin Film Optical Coating Machine/OTFC-1550

xxx

8

Ion Beam Polishing MachineÅFiSy IFS300

xxx

9

Thin Film Optical Coating Machine/JASOC900CEL

xxx

10

Vacuum Coating Machine OTFC-1300TCI-P

xxx

11

New coating machine from Cologne MIC-1350DSN

xxx

12

1AVacuum Coating Machine SVT-18003

xxx

13

BIVacuum Coating Machine MIC1350

xxx

14

Vacuum coating machine (MIC-1350DSN）

xxx

15

Box Type Vacuum Coating Machine ZZS-1350

xxx

16

Centering and edging hardwareC-300-2SL

xxx

17

Milling machineSPM60-4 SL2A

xxx

18

polisherSPS60-2 SL2A

xxx

19

Coating machineBMC-1900DS

xxx

20

Hanyi Vacuum Coating Machine HVC-1200DA HOMS

xxx

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: Common drill bits for deep hole processing and their scope of application, have you asked?

Great Light CNC Machining Services 11/01/2025 08:23

Deep hole processing is a difficult point in mechanical processing and is also a hot topic in current processing. At present, as the requirements for complex deep hole processing become more and more demanding, high precision and high efficiency are required. Therefore, it is crucial to master the processing performance and application range of different deep hole drills. This article mainly introduces the characteristics, scope of application and deep hole processing precautions of various deep hole drill bits.

What is a deep hole?

In mechanical manufacturing and processing, cylindrical holes whose depth exceeds 10 times the hole diameter are generally called deep holes. Deep holes are distinguished by the ratio of hole depth (L) to hole diameter (D) (L/D). They can generally be divided into three types: general deep holes, medium deep holes and special deep holes. (Ps: the larger the L/D ratio, the more difficult it is to treat.)

Deep holes are classified according to the L/D ratio:

(1) L/D=10~20, which is a general deep hole. It is often processed with a long twist drill bit on a drill press or lathe.

(2) L/D=20~30, which is a medium deep hole. Often treated on a lathe.

(3) L/D=30~100, which is a special deep hole. It should be machined using a deep hole drill on a deep hole drill or special equipment.

Features of deep hole processing

1. The tool holder is limited by the opening, with a small diameter and a large length, resulting in poor rigidity and low strength. It is prone to vibration, ripple and cone during cutting, which affects the straightness and roughness of the surface of deep holes.

2. When drilling and reaming holes, it is difficult for the cooling lubricant to enter the cutting area without using special devices, which reduces the durability of the tool and makes the removal of difficult chips.

3. During deep hole processing, you cannot directly observe the cutting conditions of the tool. You can only judge based on your work experience by listening to the sound while cutting, looking at the chips, touching the vibration and temperature of the workpiece, and observing the instruments. (oil pressure gauge and electric meter). Is the cutting process normal?

4. It is difficult to remove chips. Reliable means should be used to break up chips and control chip length and shape to facilitate smooth removal and avoid chip clogging.

5. In order to ensure that deep holes run smoothly during processing and achieve the required processing quality, internal (or external) chip removal devices, tool guiding and supporting devices and High pressure cooling and lubricating devices should be added to the tool. .

6. The heat dissipation conditions of the tool are poor, and the cutting temperature increases, which reduces the durability of the tool.

Types and structures of deep hole drills

Deep hole drill bits are divided into two types according to chip removal methods: external chip removal and internal chip removal. External chip removal includes gun drills and solid alloy deep hole drills (which can be divided into two types: with cooling holes and without cooling holes). Internal chip removal is divided into three types: BTA deep hole drills, jet suction drills and DF system; deep hole drills. The types and usage range of deep hole drill bits are shown in the table below.

Characteristics and processing range of various drill bits for deep hole drilling

1. Pistol practice

Gun drills got their name because they were originally used mainly for processing gun barrels and barrels in the military industry. Gun drill bits are effective deep hole machining tools for a wide range of applications, from deep hole machining of mold steels, fiberglass, plastics such as Teflon, to high strength alloys such as P20 and Inconel. In processing deep holes with strict tolerance and surface roughness requirements, gun drilling can guarantee the dimensional accuracy, positional accuracy and straightness of the hole.

Image WeChat_20240110095525.png

The working principle of the gun drilling system: the cutting fluid enters inside the drill pipe through the oil inlet on the tailstock, reaches the drill head for cooling and lubrication and evacuates chips from the V-shaped groove outside the drill bit. This system is mainly used for processing small diameter deep holes (hole diameter less than 20mm).

Photo WeChat_20240110095531.jpg

Application scope of gun drilling: gun drilling (deep hole drilling by external chip removal) is mainly used to process holes with a depth of φ2 ~ 20mm, aspect ratio L/ D>100, with accuracy IT8~IT10 and surface roughness value Ra=12.5~3.2μm hole, production efficiency is lower than drilling deep holes with elimination of internal chips.

2. Deep hole drill for internal chip removal BTA

Since the gun drill rod is asymmetrical, it has low torsional rigidity and can only transmit limited torque. Therefore, gun drilling is only suitable for processing parts with small diameter holes. In order to adapt to more complex large diameter deep hole processing requirements, deep hole drilling technology with internal chip removal has emerged. In internal chip removal, since the chips are discharged from the drill pipe and do not scrape or contact the machined surface, the surface treatment quality is higher than that of auger drilling. gun and the processing hole diameter range is also larger.

The BTA system drill bit and drill rod are hollow cylinders. The principle of operation is shown in the figure below. The cutting fluid enters the oil distributor through the inlet after being pressurized, and then flows through the sealed annular space formed by the drill bit. the shank and the hole wall towards the cutting part for cooling, and press the chips into the chip outlet on the drill bit, then discharge them from the outlet through the inner cavity of the drill pipe.

Image WeChat_20240110095536.png

Deep hole drilling for internal chip removal is suitable for processing deep holes with a diameter of 20mm or more and an aspect ratio of not more than 100. The processing accuracy is IT7~IT10, the roughness of the treated surface is Ra3.2 ~ 1.6. μm, and the production efficiency is external chip removal more than 3 times.

The main disadvantage of deep drilling by internal chip removal BTA: special machine tool equipment must be used, and the machine tool must also be equipped with an oil chip separation device to separate and recycle the fluid cutting by gravity sedimentation or electromagnetic separation. In addition, during the cutting process, a high pressure zone is formed between the workpiece and the oil distributor, so a reliable seal must be formed between the workpiece and the oil distributor before drilling.

3. Jet suction drill

The deep hole drilling system with internal chip removal has the disadvantage of significant loss in the annular oil channel. It requires higher pressure and flow during processing. For this reason, drilling technology with high production efficiency and better processing quality has been developed. walk. ——Jet suction drill.

The jet suction drill uses the principle of jet suction effect of fluid mechanics to invent a double-tube deep hole drilling method for chip removal. It uses two concentric drill rods to connect the tool to the machine tool via a connector. adopts double-layer tube cutting rod, the cutting fluid enters through the inlet after being pressurized, and 2/3 of the cutting fluid enters the annular space between the inner and outer drill rods, flows to the cutting part for cooling and lubrication, and pushes the chips into the internal cavity of the drill pipe.

Image WeChat_20240110095538.png

The remaining one-third of the cutting fluid is sprayed into the internal drill pipe at high speed from the crescent-shaped nozzle on the internal drill pipe, forming a low pressure zone in the internal cavity of the internal drill pipe , which produces a suction effect on the cutting fluid carrying the chips. It has a dual function of spraying and suction, which encourages the chips to be quickly discharged from the outlet.

The oil supply to the jet-suction drill is via the rotary connector. The guide seat mainly serves as a support and does not need to be close to the workpiece. This is a great advantage for five-axis machining. As we generally encounter non-flat surfaces during five-axis machining, the guide seat cannot be close to the workpiece. In addition, the jet suction drill will produce a vacuum effect during processing, which will remove chips and be more flexible to use.

Jet suction drilling is mainly suitable for processing holes with an aspect ratio of not more than 100 and a diameter ranging from 18 to 65mm, with an accuracy of IT9 to IT11.

4.DF system deep hole drilling

DF system deep hole drilling is also called single-pipe jet drilling. DF is the abbreviation of Double Feeder in English, and its original meaning is double oil inlet device. The DF system deep hole drill bit is a hole processing tool first developed by Nippon Metallurgical Co., Ltd. in the mid-1970s. It is developed on the basis of ordinary jet drilling. This is a processing system that combines the BTA ordinary internal chip removal deep hole drill to expel chips and the jet drill to vacuum chips. Since a drill pipe is supported by cutting fluid, the vibration is reduced, the chip removal space is large, the processing efficiency is high and the precision is good, and it can be used for high precision deep hole processing; 3 to 6 times that of gun drilling, and better than that of BTA internal drilling. Chip drills are 3 times more expensive, but the cost of use is higher.

Image WeChat_20240110095542.png

It can be seen from the relevant configurations required by the above different drill bits that no matter what chip removal method is, it is composed of workpieces, cutting tools, special auxiliary tools, machine tools, control systems and other elements. Among them, special auxiliary tools depend on the cutting fluid supply method, chip removal method and relative movement method between workpiece and tool. It can be seen that deep hole processing requires special equipment and special auxiliary tools, so the equipment structure is complex and expensive.


Precautions when processing deep holes

1. Key points of deep hole processing operations

The coaxiality of the center lines of the spindle and the tool guide sleeve, the toolbar support sleeve, the workpiece support sleeve, etc. must meet the requirements; the cutting fluid system should be smooth and normal; there should be no central hole on the machined end; face of the workpiece and avoid drilling on the inclined surface. The shape of the chips should be kept normal to avoid the generation of straight strip-shaped chips; use a higher speed to process holes when the bit is about to drill. , the speed should be reduced or stopped to avoid damage to the drill bit.

2. Key points to note when using cutting fluid for deep hole machining

A large amount of cutting heat will be generated when machining deep holes, which is not easy to diffuse. Sufficient cutting fluid should be supplied to lubricate and cool the tool. Typically, a 1:100 emulsion or extreme pressure emulsion is used; When higher machining precision and surface quality or tough materials are required, extreme pressure emulsion or high concentration extreme pressure emulsion is generally used. The kinematic viscosity of cutting oil is generally (40). ℃)10~20cm2/s, cutting fluid flow rate is 15~18m/s; when processing small diameters, use low viscosity cutting oil; For processing deep holes that require high precision, the cutting oil ratio can be 40% extreme pressure vulcanized oil + 40% kerosene + 20% chlorinated paraffin.

The pressure and flow rate of cutting fluid are closely related to the hole diameter and processing method. The specific reference is shown in the table below.

Image WeChat_20240110095548.png

3. Precautions when using deep drill bits

1) The end face of the part is perpendicular to the axis of the part to ensure reliable sealing of the end face.

2) Before formal processing, pre-drill a shallow hole in the hole position of the workpiece, which can serve as a guide and centering function when drilling.

3) To ensure tool life, it is best to use automatic tool feeding.

4) If the guide elements in the liquid inlet and the movable center support are worn, they should be replaced in time to avoid affecting the drilling accuracy.

To summarize

Deep hole processing occupies a very important position in the field of mechanical processing, accounting for about 40% of the hole processing volume. The continuous emergence of new high-hardness and high-value deep-hole parts that are difficult to machine has led to continuous improvement in the processing depth, processing precision and processing efficiency requirements of processed parts. as a key process and treatment difficulty. it is only by mastering the concept of deep holes, deep holes. Only by understanding the characteristics and difficulties of processing and having a thorough understanding of the types, structures and use ranges of different deep hole drills can we better improve the efficiency of deep holes. treatment.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: What is Wuxinmo? Where can it be used?

Great Light CNC Machining Services 11/01/2025 07:19

In centerless cylindrical grinding, the workpiece is placed between the guide wheel and the grinding wheel. One of the grinding wheels plays the role of grinding and the other grinding wheel plays the role of transmission, called the guide wheel. The bottom part of the part is supported by the support plate. The guide wheel is made of rubber and its axis forms an angle θ with the grinding wheel in the vertical direction, causing the workpiece to rotate and advance.

Common grinding defects of centerless grinders and their elimination methods are summarized as follows:

1. The pieces are not round

Cause of event

(1) The guide wheel is not rounded

(2) The number of grinding operations is small or the ellipse of the previous process is too large.

(3) The grinding wheel is dull

(4) The amount of grinding is too large or the amount of tool feed is too large

Disposal method

(1) Rebuild the guide wheel and wait for the guide wheel to round (usually until there is no intermittent noise)

(2) Appropriately increase the number of grinding times

(3) Reshape the grindstone

(4) Reduce grinding volume and retooling speed

2. Parts have edges (polygons)

Cause of event

(1) The center of the room is not high enough

(2) The axial thrust of the workpiece is too great, causing the workpiece to press against the stop pin and prevent it from rotating evenly.

(3) The grinding wheel is unbalanced

(4) The center of the room is too high

Disposal method

(1) Accurately advance the centering of the part

(2) Reduce the tilt angle of the grinder guide wheel to 0.5° or 0.25°. If the blockage cannot be resolved, check the balance of the fulcrum.

(3) Balanced grinding wheel

(4) Correctly reduce the central height of the room

3. Vibration traces on the surface of the parts (that is, fish spots and straight white lines appear on the surface of the parts)

Cause of event

(1) Machine tool vibration caused by unbalanced grinding wheel surface

(2) The center of the coin moves forward, causing the coin to jump

(3) The grinding wheel is dull or the surface of the grinding wheel is too smooth

(4) The guide wheel turns too fast

Disposal method

(1) Balance the grinding wheel carefully

(2) Lower the center of the workpiece correctly

(3) Grinding wheel or appropriately increase the dressing speed of the grinding wheel

(4) Correctly reduce the guiding speed

4. The parts are conical

Cause of event

(1) Since the busbar of the front guide plate and guide wheel is too low or the front guide plate is tilted in the direction of the guide wheel, the front part of the workpiece is small.

(2) The rear part is small due to the low surface of the rear guide plate and the guide wheel busbar or the inclination of the rear guide plate towards the guide wheel.

(3) Taper occurs at the front or back of the part for the following reasons

① The grinding wheel itself has a taper due to incorrect dressing.

②The surface of the grinding wheel and guide wheel is worn

Disposal method

(1) Move the front guide plate correctly and adjust the front guide plate to be parallel to the guide wheel busbar.

(2) After adjustment, the guide surface of the guide plate is parallel to the guide wheel busbar and on a line

①According to the taper direction of the workpiece, adjust the angle of the grinding wheel when changing the grinding wheel

②Grinding wheel and guide wheel

Photo WeChat_20240110141947.jpg

5. The center of the piece is large and the ends are small.

Cause of event

(1) The front and rear guide plates are evenly inclined toward the side of the grinding wheel.

(2) The grindstone is dressed in the shape of a drum

Disposal method

(1) Adjust the front and rear guide plates

(2) When modifying the grinding wheel, the margin for each modification should not be too large.

6. There are circular threads on the surface of the workpiece

Cause of event

(1) The front and rear guide plates protrude from the surface of the guide wheel, so that the parts are scraped by the edge of the guide wheel when exiting or entering.

(2) The bearing is too soft, and the ground cut is embedded in the surface of the bearing to form protruding burrs, which are carved into threads on the surface of the workpiece.

(3) The coolant is not clean and contains chips or sand.

(4) Due to the large amount of grinding at the outlet, it is scraped by the edge of the grinding wheel.

(5) When the center of the workpiece is lower than the center of the grinding wheel, the vertical pressure is greater, causing sand and chips to adhere to the support bristles.

(6) The grinding wheel is dull

(7) There is too much excess left in one wheel or the wheel is too thick, resulting in extremely fine thread lines on the surface of the other part.

Disposal method

(1) Adjust the front and rear guide plates

(2) Replace the hair with a smooth surface and higher hardness.

(3) Replace the coolant

(4) Round the edge of the grinding wheel so that about 20 mm at the exit of the workpiece is not ground.

(5) Properly increase the center height of the room

(6) Grindstone

(7) Appropriately reduce the amount of grinding and slow down the speed of modification

7. Cut a small piece from the front of the piece

Cause of event

(1) The front guide plate protrudes beyond the surface of the guide wheel

(2) The front faces of the grinding wheel and the guide wheel are not aligned and are very different.

(3) Too much squeaking at the entrance

Disposal method

(1) Move the front guide back slightly

(2) Replace or modify the longer of the two

(3) Reduce the amount of grinding at the entrance

8. The middle or tail of the workpiece is cut and the cuts are as follows:

1. The incision is rectangular

Cause of event

(1) The rear guide plate has a good surface on the guide wheel, which prevents the parts from rotating and continuing to grind on the side surface.

(2) The rear support pad extends too long and the ground parts do not fall, preventing the rotation and advancement of the ground parts.

Disposal method

(1) Move the rear guide plate back appropriately

(2) Reinstall the support cushion

2. The incision is angular or has many micro-shaped marks

Cause of event

(1) The rear guide plate lags behind the surface of the guide wheel

(2) The center of the part advances too high, causing the part to jump out.

Disposal method

(1) Move the rear guide plate slightly forward.

(2) Reduce the center height of the room correctly

9. The surface of the parts is not shiny enough

Cause of event

(1) The tilt angle of the guide wheel is too large, resulting in the workpieces being cut too quickly.

(2) The changing speed of the grinding wheel is too fast, and the surface of the grinding wheel is not bright when changed.

(3) The guide wheel is modified too thick

Disposal method

(1) Reduce the tilt angle

(2) Reduce the modification speed and modify the grinding wheel from scratch

(3) Rebuild the guide wheel

Note: It is prohibited to turn on the coolant when the grinding wheel is not working. If the coolant is opened first, in order to avoid the occurrence of a malfunction, the machine should be driven intermittently (that is, on, off, on, off). until coolant is emitted in all directions, then get to work.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: This article explains everything about faucets!

Great Light CNC Machining Services 11/01/2025 06:13

1

Faucet classification

(1) Cutting tap

1) Straight flute tap: used for processing through holes and blind holes. Iron shavings exist in the tapping groove, and the quality of processed threads is not high. It is more commonly used for processing short chip materials, such as gray cast iron. iron.

2) Spiral groove tap: used for processing blind holes with hole depth less than or equal to 3D. The iron shavings are discharged along the spiral groove, and the thread surface quality is high.

10°~20° helix angle tap can process thread depth less than or equal to 2D;

28°-40° helix angle taps can process thread depths less than or equal to 3D;

The 50° helix angle tap can process thread depth less than or equal to 3.5D (4D special working condition).

In some cases (hard materials, large pitches, etc.), in order to obtain better resistance of the tooth tips, taps with helical flutes are used to machine through holes.

3) Spiral point taps: generally only used for through holes, the length/diameter ratio can reach 3D~3.5D, the iron chips are discharged downward, the cutting torque is small, and the surface quality is good. of processed threads is high. It is also called Edge Corner Tap or Tip Tap.

When cutting, it is necessary to ensure that all cutting parts are penetrated, otherwise teeth may chip.

(2) Extrusion tap

It can be used for processing through holes and blind holes. The tooth shape is formed by plastic deformation of the material. It can only be used to process plastic materials.

Its main characteristics:

1) Use plastic deformation of the workpiece to process threads;

2) The faucet has a large cross section, high strength and is not easy to break;

3) The cutting speed can be higher than that of cutting taps, and the productivity is also increased accordingly;

4) Due to the cold extrusion process, the processed thread surface has improved mechanical properties, high surface roughness and improved thread strength, wear resistance and corrosion resistance;

5) Chip-free processing.

Its faults are:

1) Can only be used to process plastic materials;

2) High manufacturing cost.

There are two structural forms:

1) Oil groove extrusion taps are only used for vertical machining of blind holes;

2) Extrusion taps with oil grooves are suitable for all working conditions, but generally small diameter taps are not designed with oil grooves due to manufacturing difficulties.

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2

Structural parameters of faucets

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(1) Overall dimensions

1) Total length: Pay attention to certain working conditions which require particular lengthening.

2) Slot Length: Same as above

3) Shank Square: At present, common shank square standards include DIN (371/374/376), ANSI, JIS, ISO, etc. When selecting, you should pay attention to the matching relationship with the tapping tool holder.

(2) Threaded part

1) Precision: selected according to specific thread standards. The ISO1/2/3 metric thread level is equivalent to the national standard H1/2/3 level, but attention should be paid to the manufacturer’s internal control standards.

2) Cutting cone: The cutting part of the tap formed a partially fixed pattern. Usually, the longer the cutting cone, the better the life of the faucet.

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3) Correction teeth: They play an assistance and correction role, particularly when the tapping system is unstable. The more correction teeth, the greater the tapping resistance.

(3) Chip evacuation groove

1) Groove shape: affects the formation and evacuation of iron shavings and is generally an internal secret of each manufacturer.

2) Front angle and clearance angle: When the angle of the tap increases, the tap becomes sharper, which can greatly reduce the cutting resistance, but the strength and stability of the tooth tip decrease.

3) Number of flutes: Increasing the number of flutes increases the number of cutting edges, which can effectively increase the life of the tap, but it will compress the chip evacuation space, which will be detrimental to the tap. chip removal;


3

Faucet materials and coatings

(1) Faucet material

1) Tool steel: mainly used for incisor taps used by hand, which is no longer common.

2) Cobalt-free high-speed steel: Currently widely used as tapping materials, such as M2 (W6Mo5Cr4V2, 6542), M3, etc., marked with HSS code.

3) Cobalt-containing high-speed steel: Currently widely used as tapping materials, such as M35, M42, etc., with HSS-E marking code.

4) Powder metallurgy high speed steel: used as a high-performance tapping material, its performance is greatly improved compared with the above two. Each manufacturer’s naming methods are also different, and the marking code is HSS-E-PM.

5) Carbide materials: generally use ultra-fine particles and good toughness levels, which are mainly used to make straight flute taps for processing short chip materials, such as gray cast iron, aluminum to high silicon content, etc.

Faucets are highly dependent on materials. Choosing the right materials can further optimize the structural parameters of the faucet, making it suitable for efficient and more demanding working conditions, while having a longer service life. At present, large tap manufacturers have their own material factories or material formulas. At the same time, due to cobalt resource and price problems, a new cobalt-free high-performance high-speed steel has also been launched.

(2) Faucet coating

1) Steam oxidation: place the faucet in high temperature water steam to form an oxide film on the surface, which has good adsorption on the coolant, can reduce friction and at the same time prevent bonding between tap and cut material. . Suitable for processing mild steel.

2) Nitriding treatment: The surface of the tap is nitrided to form a surface hardened layer, which is suitable for processing cast iron, cast aluminum and other materials that cause heavy tool wear.

3) Steam + nitriding: combines the advantages of the two above.

4) TiN: golden yellow coating, with good hardness and lubricity, and good coating adhesion, suitable for processing most materials.

5) TiCN: blue-gray coating, hardness is about 3000HV, heat resistance reaches 400°C.

6) TiN+TiCN: dark yellow coating, with excellent hardness and lubricity, suitable for processing most materials.

7) TiAlN: blue-gray coating, hardness 3300HV, heat resistance up to 900°C, can be used for high-speed processing.

8) CrN: silver gray coating, excellent lubrication performance, mainly used for non-ferrous metal processing.

The coating of the faucet has a very obvious impact on the performance of the faucet, but currently most manufacturers and coating manufacturers work together to research special coatings.


4

Factors Affecting Tapping

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(1) Tapping equipment

1) Machine tools: can be divided into two processing methods: vertical and horizontal. For tapping, vertical processing is better than horizontal processing. When using external cooling for horizontal processing, consideration must be given to whether the cooling is sufficient.

2) Tapping tool holder: It is recommended to use a special tapping tool holder for tapping. If the machine tool is rigid and stable, the synchronous tapping tool holder is preferable. Rather, a flexible tapping tool holder with axial/radial compensation. should be used as much as possible. Except for small diameter taps (

3) Cooling conditions: For tapping, especially extrusion taps, the coolant requirements are lubrication > cooling in actual use, it can be adjusted according to the conditions of the machine tool (when the use of an emulsion, the recommended concentration is greater than 10%).

(2) Treated parts

1) Material and hardness of the part to be treated: The hardness of the material of the part must be uniform. It is generally not recommended to use taps to process parts exceeding HRC42.

2) Tapping the bottom hole: bottom hole structure, choose the accuracy of the bottom hole size;

(3) Processing parameters

1) Speed: The listed speed is based on the type, material, material and hardness of the tap, the quality of the tapping equipment, etc.

It is generally chosen according to the parameters given by the faucet manufacturer. Speed ​​must be reduced under the following working conditions:

– Poor rigidity of the machine tool; significant faucet runout; insufficient cooling;

– The material or hardness of the tapping area is uneven, such as solder joints;

– The faucet is extended or an extension is used;

– Lying down, it’s cold outside;

– Manual operations, such as bench drills, radial drills, etc. ;

2) Feed: Rigid tapping, feed = 1 step/revolution.

Flexible tapping and the tool holder compensation variable is sufficient: feed = (0.95-0.98) steps/revolution.


5

Tips for Selecting Faucets

(1) Tolerances of taps with different precision levels

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Basis of selection: The precision level of the tap cannot be selected and determined solely on the basis of the precision level of the thread being processed.

1) The material and hardness of the part to be treated;

2) Tapping equipment (such as machine tool conditions, clamping tool holders, cooling rings, etc.);

3) The manufacturing accuracy and error of the faucet itself.

For example: when processing 6H threads on steel parts, you can choose 6H precision taps; When processing gray cast iron, because the average diameter of the tap wears quickly and the expansion of the screw hole is small, it is better to choose 6HX precision. taps. Press, life will be better.

Notes on the precision of Japanese taps:

1) OSG cutting tap uses OH precision system. Different from the ISO standard, the OH precision system forces the entire width of the tolerance zone from the lowest limit, and every 0.02mm is used as the precision level, named OH1, OH2, OH3, etc. .;

2) OSG extrusion tap uses RH precision system. The RH precision system forces the entire width of the tolerance zone from the lowest limit, and each 0.0127 mm is used as the precision level, named RH1, RH2, RH3, etc.

Therefore, when using ISO precision taps to replace OH precision taps, you cannot simply think that 6H is approximately equal to the OH3 or OH4 level. It must be determined by conversion or based on the customer’s actual situation.

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(2) Faucet dimensions

1) The most commonly used currently are DIN, ANSI, ISO, JIS, etc. ;

2) Suitable overall length, blade length and shank size can be selected according to different processing requirements or existing conditions of customers;

Image WeChat_20240111100606.png

3) Interference during treatment;

Image WeChat_20240111100609.png

(3) 6 basic factors for faucet selection

1) Thread processing type, metric, imperial, American, etc. ;

2) Threaded bottom hole type, through hole or blind hole;

3) Material and hardness of the part being processed;

4) The depth of the full thread of the part and the depth of the bottom hole;

5) The precision required by the threading of the part;

6) Faucet appearance standards (special requirements should be specially marked).

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: Who said that a lathe can only turn “round” laps? Let me try to turn a “square” one!

Great Light CNC Machining Services 11/01/2025 05:11

For small factories, “versatility” is a necessary skill. Today we will see how to process polygons with a lathe.

Normally, the surface treatment of the rotating body is carried out on a lathe. However, often due to lack of equipment or unbalanced load on the machine tool, after technical transformation of the lathe, it can also be used for other processing (non-turning), such as processing of polygons, grinding processing, rolling processing and thread milling. treatment.

Facts have proven that taking technical measures adapted to local conditions not only requires low investment, is quick to start and gives good results, but is also a good way to compensate for insufficient or unmatched equipment. the scope of use of towers, especially for small and medium-sized factories and enterprises, has practical significance.

01

How polygon processing works

To process polygonal parts on a lathe, you need to install a special device as shown in the figure.

1-Cutter 2-Workpiece 3-Chuck 4-Universal coupling 5-Transmission 6-Screw 7-Base plate

During turning, it is installed on the central sliding plate, so that the workpiece and the tool rotate in the same direction, and the speed ratio relationship between the tool and the workpiece with a certain number of turning heads tools is used to achieve relative movement. of the tool and the workpiece, so that the shape can be made according to the forming law. Surface forming, complete the processing of square, hexagonal, equilateral triangles, trapezoid, drum, waist, flat, rhombus, irregular polygon and conical polygon workpieces. .

Photo WeChat_20240112100730.jpg

For example, when machining an equilateral triangle, the transmission ratio between the tool and the workpiece is i=3. Therefore, during the cutting process, the path of the tool tip relative to the workpiece axis is a periodically repeated closed curve. and the middle part surrounded by the curve forms a rough triangle.

Photo WeChat_20240112100733.jpg

If the axis of the workpiece is located outside the circle of movement of the tool tip, it is called the “exterior cutting method” and the triangle presented is that shown in figure a. If the axis of the workpiece is located inside the circle of movement of the tool tip, it is called an “exterior cutting method”; “internal cutting method” and the triangle presented is as follows. As shown in figure b.

It can be seen from the presented triangular figure that whether the external cutting method or the internal cutting method is used, the surfaces of the processed triangular workpiece are not flat surfaces, but approximately flat arcuate surfaces. Hence, the method of turning polygons mentioned above. , It can only be used in treatments that do not require high surface flatness.

02

Introduction to the now widely used cutting tools

The above introduction is a traditional theory, but in practical applications, there are different forms of cutting tools. The principles are the same, but when the principle is introduced, the cutting tool performs the main movement on the spindle and the workpiece performs auxiliary movement. In practical applications, the workpiece performs the primary movement on the spindle.

In polygonal turning, a flying cutter head is used to cut polygons (three to eight sides) on the sides of an axially symmetrical part. The workpiece (main spindle) and the rotating tool (flying cutter head) work together synchronously to machine the contact surface.

The amount of surface area cut depends on the gear ratio and the number of cutting tool edges. The workpiece and tool rotate in opposite directions.

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↑↑Car hexagon↑↑

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↑↑Car rectangle↑↑

Two-blade knives are used for cutting quadrilateral-type shapes, and three-blade tools are used for cutting hexagon-type shapes, etc. If a different gear ratio is used or the number of cutting edges of the tool is changed, larger depressions or prominent deflection arcs may appear on the workpiece surface.

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Due to this principle, the contour trajectory generated by the tool tip is exactly an ellipse, but the curve applied on the force surface of the wrench is a section with a larger radius of curvature in the ellipse, it therefore does not affect the assembly of tightening and loosening.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: The processing skills and precautions of grooving and cutting are worth collecting!

Great Light CNC Machining Services 11/01/2025 04:09

The parting and grooving process is an important part of turning operations and presents many unique challenges. During the machining process, the limitations of many factors such as machine tool and tool rigidity, cooling conditions, programming technology, tool performance, etc. arise. will cause problems in machining efficiency, quality and safety. At the same time, the processing area of ​​cutting and grooving is very narrow, and there are high requirements for chip removal, chip control and blade safety. High reliability tool materials and excellent groove structures have become important indicators sought by the market, and high. -High-performance cutting and grooving tools Combined with exquisite processing technology, it has become an important way to solve the efficient and high-quality processing of cutting and grooving. Today we will talk about the tips and methods of choosing grooving and cutting tools.

Application and processing characteristics of cutting and grooving tools

Cutting tools and grooving tools are widely used in mechanical processing, automobile manufacturing, metal processing, electronic manufacturing and other fields. For example, in automobile manufacturing, cutting tools are used for grooving and processing automobile parts. In bearing processing, grooving tools are used to process bearing grooves, etc. Cutting and grooving tools play an irreplaceable role in mechanical processing and production. Their superior features and wide range of application areas have contributed to the development and progress of the manufacturing industry.

At the same time, cutting and cross-cutting processes are characterized by a very narrow cutting area, which poses difficulties in controlling the chips generated during machining. Particularly during the cutting process, the tool is surrounded on both sides by the workpiece, which limits the path of chip evacuation. At the same time, fine chips generated during cutting and grooving tend not to break, and uncontrolled shavings from the ribbon can cause chip jams, damage the workpiece, and endanger the safety of the operator. Additionally, chip control issues can also hinder the implementation of unattended or “fully automated” machining.

In addition, large chip deformation, large cutting force, concentrated cutting temperature and poor tool rigidity are also important factors that harm the cutting and grooving process. Choosing more optimized processing technology solutions and high-performance cutting and cutting tool products is an important way to solve the problem of cutting and grooving processing.


Cutting and grooving processing technology

The front end of the groove or grooving insert is the primary cutting edge, with secondary cutting edges on both sides. The main cutting edge is a cross feed during the cutting process. At the same time, it supports significant cutting forces. It is difficult to break and unload the cutting, the cutting edge temperature is high, coupled with the influence of insufficient cooling, the safety of cutting processing faces greater challenges. Therefore, facing different processing requirements, appropriate processing technology should be selected to achieve efficient and safe cutting and grooving processing.

●Selection of working conditions system

There are specific setup recommendations for cutting and grooving tools. When installing the tool, care must be taken to ensure that the blade is truly perpendicular to the axis of the workpiece. This minimizes axial forces on the tool and prevents rubbing against the sides of the insert. Regarding the position of the tool, the center height of the cutting edge should be as close as possible to the center of the workpiece and the deviation should be within ± 0.1 mm. This also helps avoid excessive pressure on the tool and avoids shortening the tool. life.

Additionally, stable working conditions are crucial for cutting and grooving. Stable cutting conditions not only ensure higher processing efficiency, but also achieve better processing quality. Therefore, for CNC lathes, try to ensure that the grooving processing position is as close as possible to the chuck position, and at the same time, try to use a larger diameter toolbar and the Smaller tool overhang without interfering with the workpiece.

● Selection of cutting parameters

The cutting parameters of parting off and grooving tools are different from ordinary turning. If the spindle speed is constant, the cutting speed of the cutting tool will decrease to zero when it reaches the center of the bar. Slow speeds put a lot of pressure on the tool and can cause material to stick to the cutting edge. Therefore, the feed should be reduced as the tool approaches the center of the workpiece.

Blades used in crosscutting and grooving processes are generally narrow blades. At the same time, the cutting process is unstable due to the main side feed. Adjusting cutting parameters can effectively optimize chip deformation. Reasonable cutting speed and feed can effectively achieve clock-like chip morphology, and inserts with different geometry types generally have the most suitable range of cutting parameters. The following is a common chip morphology during cutting and grooving.

Common chip morphology in cutting surface and groove processing

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● Reasonable selection of cooling system

Reasonable selection of cooling system can effectively improve chip breaking and cooling effect of cutting and grooving. At present, plain water cooling is the most common form of cooling for cutting and grooving. However, pouring coolant often does not create enough pressure to reach the cutting zone in parting off and grooving applications. Additionally, the position of the nozzle for pouring the coolant is difficult to determine, so the coolant cannot flow to the parts where it is most needed. Finally, the relatively low flow rate of poured coolant can turn into vapor in the cutting area, creating an insulation layer that prevents the heat generated during the cutting process from dissipating. Therefore, in recent years, high-pressure jet cooling has become a popular form of cooling for cutting and grooving. In order to achieve the best results, high pressure coolant should be delivered to a fixed point and as close as possible to the cutting area to ensure chip breakage and optimization of the cooling effect, thereby improving stability of the cutting process and a longer blade. life.

● Optimization of processing technology

Choosing the appropriate cutting and grooving technology and processing method can not only optimize the processing process, but also improve the processing efficiency and quality. The processing technology selected for different groove shapes is different, so it should be combined with the groove characteristics and processing operability. For general groove shapes, simply cut straight; for deeper grooves, you must use the pecking cycle control to deal with the chips; for wider grooves, use the grooving + horizontal turning method to process the arc grooves when processing; use round head turning tools and semi-precision tool tip for processing compensation orders.


Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: Structural Design Principles of Sheet Metal Bended Parts

Great Light CNC Machining Services 11/01/2025 03:08

It is generally believed that all sheet metal materials of uniform thickness are collectively referred to as sheet metal. Commonly used sheet metal materials include stainless steel, galvanized steel sheets, tinplate, copper, aluminum and iron. This article mainly analyzes the basic principles of sheet metal product design.

1. Minimum panel curvature radius

When the plate is folded, if the fillet at the fold is too small, cracks will easily occur on the outer surface. If the bend fillet is too large, it will be difficult to guarantee the accuracy of the folded part due to the impact of springback. A minimum radius of curvature is specified for this purpose. See table 4.1-3.

Image WeChat_20240116095900.png

2. The height of the curved straight edge should not be too small, otherwise it will be difficult to form sufficient bending moment and it will be difficult to obtain parts with precise shapes.

The value h≥R+2t can be used. See Figure 4.1-5.

3. When punching with a curved edge, the distance L between the edge of the hole and the center of the curvature radius R should not be too small to avoid deforming the hole after bending.

The value L ≥ 2t can be used. See Figure 4.1-6.

Image WeChat_20240116095906.png

4. When

Image WeChat_20240116095909.png

5. On U-shaped folded parts, both folded sides should be equal in length to avoid moving to one side during folding.

If this is not permitted, a process positioning hole can be provided. As shown in Figure 4.1-8.

Image WeChat_20240116095912.png

6. Avoid cracking or deformation when the side (trapezoid) is bent.

A reserved notch should be designed or the root should be made into a stepped shape. Groove width K≥2t, groove depth L≥t+R+K/2.

Image WeChat_20240116095915.png

7. To prevent rounded corners from being compressed during bending and causing creases after extrusion, reserved incisions should be designed.

Such as the shape of the cutouts at the rounded corners of the side panels (top and bottom ends) of the outdoor unit.

Image WeChat_20240116095919.png

Image WeChat_20240116095922.png

8. To avoid creases on both sides of the right angle after bending, reserved incisions should be designed.

Image WeChat_20240116095925.png

Image WeChat_20240116095929.png

9. Prevent the cut shape from bouncing back after folding.

Image WeChat_20240116095932.png

10. Prevent cracks from bending after punching.

Image WeChat_20240116095936.png

11. Prevent one side from shrinking inward when folding.

Process positioning holes can be designed, or both sides can be bent at the same time. The shrinkage problem can also be solved by increasing the width.

Image WeChat_20240116095939.png

12. Overlap shape bent at right angle.

Image WeChat_20240116095943.png

13.Folding of the convex part

If the fold line and the walk line match as shown in Figure A, cracks and deformations may occur at the root. Therefore, make the curved line give way to the walking line as shown in figure b, or design the cutouts as shown in C and D.

Image WeChat_20240116095946.png

14. To avoid bending, the holes on the bending surface will deform after being subjected to stress. The distance value from the edge of the hole (to the lower root) should be A≥4.

Image WeChat_20240116095949.png

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

CNC Knowledge: 5 methods to measure the dimensional accuracy of machining parts

Great Light CNC Machining Services 11/01/2025 02:07

Trial cutting method

That is, first cut a small part of the processing surface, measure the size obtained by the trial cut, and adjust the position of the tool cutting edge relative to the workpiece appropriately according to the processing requirements , then try cutting again. then measure. After two or three attempts of cutting and measuring, when the machine is processing, once the size meets the requirements, the entire surface to be processed is cut.

The trial cutting method is repeated by “trial cut – measure – adjust – trial cut again” until the required dimensional accuracy is achieved. For example, bore processing test of box hole system.

The precision achieved by the trial cutting method can be very high and does not require complicated devices. However, this method is time consuming (requiring multiple adjustments, trial cuts, measurements and calculations), is inefficient and relies on the trial cutting method. Technical level of workers and precision of measuring instruments, quality is unstable, so it is only used for the production of single parts and small batches.

As a type of trial cutting method – matching, it is a method of processing another workpiece that matches it based on the workpiece being processed, or a method of combining two (or more) pieces together for processing. The requirements for the final dimensions processed in the production process are based on the requirements corresponding to the parts processed.

adjustment method

The precise relative positions of machine tools, fixtures, cutting tools and parts are adjusted in advance with prototypes or standard parts to ensure the dimensional accuracy of the part. Since the size is adjusted in advance, there is no need to try cutting again during processing. The size is automatically obtained and remains unchanged during processing of a batch of parts. For example, when using a milling machine fixture, the tool position is determined by the tool setting block. The essence of the setting method is to use the setting device or tool setting device on the pre-assembled machine tool or tool holder to make the tool achieve a certain position accuracy relative to at the machine tool or assembly, then processing a batch of workpieces.

Feeding the tool according to the dial of the machine tool and then cutting is also a type of setting method. This method first requires determining the scale on the dial by a cutting test. In mass production, tool setting devices such as fixed range stops, prototypes and models are often used for setting.

Compared with the trial cutting method, the adjustment method has better machining precision stability and higher productivity. It does not have high requirements for machine tool operators, but it does have high requirements for machine tool fitters. It is often used in batch production and mass production. .

sizing method

The method of using the corresponding size of the tool to ensure the size of the processed part of the workpiece is called sizing method. It is processed using standard size tools and the size of the processing surface is determined by the size of the tool. That is, tools with a certain dimensional accuracy (such as reamers, reamers, drills, etc.) are used to ensure the accuracy of the processed parts of the workpiece (such as holes).

The sizing method is easy to operate, has high productivity, and the processing accuracy is relatively stable. It has almost nothing to do with the technical level of the worker. It has high productivity and is widely used in various types of production. Such as drilling, reaming, etc.

active measurement method

During the machining process, the machining dimensions are measured during machining, and after comparing the measured results with the dimensions required by the design, the machine tool is either allowed to continue working or stopped. This is the active measurement method.

Currently, active measurement values ​​can be displayed digitally. The active measurement method adds the measuring device to the process system (i.e. the unit of machine tools, tools, fixtures and parts) as a fifth factor.

The active measurement method has stable quality and high productivity, which is the development direction.

automatic control method

This method is composed of a measuring device, a power supply device and a control system. It combines the measurement, feeding device and control system into an automatic processing system, and the processing process is automatically completed by the system.

A series of tasks such as dimensional measurement, tool compensation adjustment, cutting processing and machine tool parking are automatically carried out to automatically achieve the required dimensional accuracy. For example, when processing on a CNC machine tool, the processing sequence and processing accuracy of parts are controlled through various program instructions.

There are two specific methods of automatic control:

1. Automatic measurement, that is, the machine tool has a device that automatically measures the size of the workpiece. When the workpiece reaches the required size, the measuring device issues an instruction for the machine tool to automatically retract and stop working.

2. Numerical control, that is, the machine tool has a servo motor, a pair of rolling screw nuts and a complete set of numerical control devices that control the precise movement of the tool holder or workbench. Acquisition of size (movement of the tool holder). or established) is programmed in advance. The program is automatically controlled by a computer numerical control device.

The initial automatic control method was carried out using active measurement and mechanical or hydraulic control systems. At present, pre-arranged programs according to treatment requirements have been widely used. adapt to changes in processing conditions during processing, automatically adjust the processing amount, and automatically control processing with adaptive control machine tools that optimize the processing process according to specified conditions.

The automatic control method has stable quality, high productivity, good processing flexibility, and can adapt to multi-variety production. It is the current development direction of mechanical manufacturing and the basis of computer-aided manufacturing (CAM).

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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CNC Knowledge: Do you know the bad ideas and concepts of high-speed milling?

Great Light CNC Machining Services 11/01/2025 01:07

In the manufacturing industry, there are many misconceptions regarding high-speed milling, including the following:

High-speed milling is just a milling machine equipped with a high-speed spindle

The higher the spindle speed, the faster the processing speed

High speed milling machine is a new technology, just to replace the general traditional milling machine

A 20,000 rpm spindle is sufficient for mold production needs.

High-speed milling is only accelerated by increasing the axial server

High-speed milling can only process electrodes

………


In fact, high-speed milling is a new technology and new application philosophy:

If you want to bring out the efficiency of high-speed cutting, you must work closely with each link. If one of the links is not well matched, you will not be able to bring out the efficiency of high-speed cutting.

High-speed tool holders and cutters

high speed spindle

Highly powerful X, Y and Z axes

High Speed ​​CNC Controller

high speed programming strategy


The situation when cutting at high speed

As the rotation speed increases to a certain level, the temperature and cutting force of the tool gradually decrease. This phenomenon is used in high-speed milling technology.

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Conventional milling

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High speed milling

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Dispersion rate of high speed cutting heat source

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Machining concepts of high-speed milling (HSM) and high-performance milling (HPM)

Example: Rough machining of hardened steel, material hardness >55HRC

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Application area of ​​high speed milling

1) In order to match the specifications of the spindle and ensure the stability and safety of processing, the tool diameter does not exceed 16mm (HSK-E40).

2) Compared with traditional milling, the cutting removal rate of high-speed milling is relatively low, which is very suitable for small parts and mold processing applications.

3) It can be used in new processing applications such as thin sheet processing and micro-processing.

4) It is a new concept processing method for soft materials or ultra-hard materials.

Example: An aluminum part with a wall thickness of 0.5 mm cannot be produced without high-speed milling technology.

1. High speed matching tool holder and tool

In fact, it is not the machine that cuts, but the tool! Tools are like the tires on a car, the only parts of the car that touch the ground. Good and suitable tires are the key to success in racing. The selection of cutting tools and processing conditions can be based on information provided by the cutting tool manufacturer, but the user should always make adjustments based on actual processing conditions.

Tool selection criteria:

Diameter (depending on the geometric dimensions and precision of the part)

Type (roughing, finishing, grooving, 3D contouring, edge machining…)

Shape (ball cutter, round nose cutter, multi-edge cutter, etc.)

Materials (high speed steel, cemented carbide, cermet, diamond, cubic boron nitride CBN)

Tool coating (TiN, TiCN, TiAlN…)

Quality (radial voice, shape precision, dynamic balance, rigidity)

2. High speed spindle

In fact, the high-speed spindle is comparable to the high speed and power of an F1 racing car’s engine.

Pins can be roughly divided into two specifications:

1) With ≥ high torque bearings, the current maximum speed can reach 54,000 rpm.

2) Without bearing (gas) ≥ low torque, but very fast speed (>100 rpm).

High torque allows you to cut larger materials, using larger tools and harder materials. The high rotation speed allows for faster cutting rates and achieves HSM effects.

3. High dynamic performance of each axis

In fact, the machine bed structure itself is like the chassis of a car, strong and safe to absorb shock and vibration.

Traditional hard rails can achieve better precision through adjustments on the machine table, but they cannot achieve the high-speed processing that linear sliding rails can achieve. With high-speed axles and a solid bed structure, acceleration is a key factor. High acceleration spindles reduce wasted time, provide better cutting surfaces and reduce tool wear.

4. High speed CNC milling controller

In fact, the controller is like a driver, and his operational skills determine the outcome of the car. This requires forethought, sensitivity and rapid response skills.

5. CAM processing strategy for high-speed milling

In fact, there are many paths to get from one point to another, but all paths will have different effects on speed, area, etc.


Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

CNC Knowledge: Summary of gear tooth manufacturing processing technology

Great Light CNC Machining Services 11/01/2025 00:05

Gear tooth processing refers to the process of transforming gear blanks into specific tooth shapes by cutting, grinding, heat treatment and other methods. Common gear tooth manufacturing processes include:

1. Tooth milling: Use a milling cutter to cut the tooth shape on the gear blank. This process is suitable for processing gears that do not require high precision, such as gears of agricultural machinery, construction machinery and other fields.

2. Gear shaping: Use a gear shaping cutter to cut the tooth shape on the gear blank. This process is suitable for processing gears with complex tooth shapes such as internal gears and double gears.

3. Gear size cutter: Use a gear cutter tool to cut out the tooth shape on the gear blank. This process is suitable for processing gears with high precision requirements, such as gears in automobile, aerospace and other fields.

4. Gear grinding: Use a gear cutter to grind the tooth shape on the gear blank. This process is suitable for processing gears with extremely high precision requirements, such as gears of watchmaking, precision instruments and other fields.

5. Heat treatment: Heat treatment is carried out on the gear blank to improve its mechanical properties and wear resistance.

Different gear tooth manufacturing processes are suitable for different application scenarios, and the appropriate process should be selected according to the precision requirements, size, material properties and other factors of the gear.

Consultation hotline for gear milling, gear shaping, gear hobbing, gear grinding and other machine tools: 15910974236

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

The role of inclined bed CNC lathes in various fields

Great Light CNC Machining Services 10/01/2025 23:38

　　Inclined bed CNC latheIt is a high-precision, high-efficiency automated machine tool whose working principle is based on the combination of CNC technology and traditional lathe processing principles. It controls the movement of the workpiece on three coordinate axes through a CNC system to achieve precise machining processes. During the machining process, the workpiece is clamped to the bed with a beveled spindle centerline, while the tool passes through the turret for fast, precise cutting. It is also equipped with a multi-station turret or motorized turret, which gives it a wide range of process performance and can process complex parts such as linear cylinders, oblique cylinders, arcs and various threads, grooves , endless screw, etc. , and has linear interpolation, circular arc interpolation various compensation functions. In the mass production of complex parts, inclined bed CNC lathes have played a good economic role.
　　Inclined bed CNC latheMain areas of application:
1. Aerospace field: capable of processing various high-precision aerospace parts, such as engine blades, turbine disks, shafts, etc. These parts require high precision and surface quality to meet these demanding machining requirements.
2. Automobile manufacturing industry: In the automobile manufacturing process, it is used to process various shaft and disc parts, such as crankshafts, camshafts, gears, etc. These parts are essential components of the vehicle’s engine and transmission system and are essential to the performance and reliability of the vehicle.
3. Mold making industry: It is also widely used in mold making. It can process high-precision mold cavities and cores for the production of various plastic products, metal products, etc. The precision and quality of the mold surface directly affect the quality and production efficiency of the product, so it plays an important role in the manufacturing of the mold.
4. Precision machinery industry: suitable for processing various precision machinery parts, such as optical instrument parts, precision measuring instrument parts, etc. These parts have high requirements for precision and surface quality, which can be met to ensure processing accuracy and stability of the parts.
5. Medical equipment manufacturing: In medical equipment manufacturing, it is used to process various precision medical parts, such as surgical instruments, medical device casings, etc. These parts have high requirements for precision and surface quality to ensure the performance and safety of medical devices.
6. Electronic communications industry: It can also be used to process precision parts in the electronic communications industry, such as connectors, connectors, etc. These parts also require high precision and surface quality to meet these machining needs.

Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.

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