1. What basic requirements should the main part of the axis meet?
The basic requirements that the main parts of the axis must meet are rotary precision, rigidity, resistance to vibrations, temperature elevation and thermal deformation and precision. The spindle rotation precision refers to the radial and axial blow to the main tree of the main shaft of the part or the tool on the load and the low speed rotation conditions. The rotation accuracy depends on the manufacture, the accuracy of the assembly and the adjustment of the pin, the bearing, the hole in the box, etc. The rigidity of the spindle part refers to its ability to resist the deformation under the action of adding loads. is a complete reflection of the spindle and the bearing. The anti-vibration resistance of spindle parts refers to the ability to resist suffering and self-excitement. The vibration of the part of the main axis will directly affect the quality of treatment of the space surface, the use of the tool of the tool and will generate noise. The accuracy of the component of the pin means that the ability to maintain its original manufacturing precision in the long term must improve its resistance to wear.
2. What are the directional positioning methods of the main axis? What are everyone’s characteristics? Applicable opportunity
(1) Avant Configuration
The rolling of the thrust in the two directions is distributed to the front support; CNC machines with higher accuracy and rigidity.
(2) Back configuration
The two instructions in the push of the two directions are arranged at the rear support; and molding and multiple towers.
(3) Configuration at both ends
The rolling of the thrust of the two directions is placed at the two front and rear supports; be used to eliminate the gap and compensate for thermal expansion;
(4) Intermediate configuration
The thrust bearing in the two directions is configured on the front of the front support; complicated and the rise in temperature can be higher.
3. Describe the principle of work of the static pressing of the spindle
The static pressure bearing of the main shaft is generally used to use the liquid static pressure bearing. The static pressure bearing provides a certain pressure oil for the fuel power system. Consequently, the pressure of the film of rolling oil has nothing to do with the speed of the spindle, and the rolling capacity does not change with the speed. Compared to dynamic pressure as a dynamic turnover: the following advantages are: a high load capacity; speed speeds;, can also operate at extremely high speeds;
The principle of static static turnover of fixed pressure is illustrated in the figure below. The oil cavity is separated by an axial groove with oil feedback. The oil pressure power by the hydraulic pump is the oil of the fixed value P, which circulates through the ship T1, T2, T3 and T4 in each oil cavity. The role of the accelerator is to automatically adjust the pressure of each oil cavity with the change of load of the external load, thus balanced the external load. When an external load effect (does not take into account the weight), the oil pressure of each oil cavity is equal, that is to say, p1 = p2 = p3 = p4, keep a balance, The tree is in the center, the cover of the oily cavity is equal to the cycle, that is to say h = H1 = H2 = H3 = H4, and the resistance to the fluid of the space is equal.
When there is an external load F at the bottom, the neck is lost and a slight displacement E is offset along the direction of the load. , the flow is reduced, the diversion device T3 The reduction in pressure decreases. In the same way, the gap in the oil cavity increases, that is to say H1 = H + E, the liquid resistance of the space is reduced and the flow increases. The T1 accelerator pressure has increased and the P1 oil cavity has decreased. The pressure difference between the two ΔP = P3-P1, the pressure difference will repel the main axis to the center to balance the external load F.
4. Try the applicable characteristics and opportunities of the main three -wheel configuration type illustrated in the figure.
(1) 46000 are the cone rolls. The cylindrical roller bearings, this rolling capacity is large, the friction coefficient is low, the temperature is low, but it cannot withstand the axial force. This configuration method is mainly an axial force in the bearing behind, so it is equivalent to the back configuration.
(2) This configuration method is mainly an axial force in the axial force in the previous paragraph, so this bearing configuration is equivalent to the front configuration; Heating; The rear extension of the heat does not affect axial accuracy;
(3) 2268000 is a two -lane push towards the cardiac ball bearings. But the front support structure is complicated and the rise in temperature can be higher.
5. According to the component of the main axis of the figure, how to pass the axial force? How to adjust the gap?
Answer: the axial force transmission is indicated in the figure below
Adjust the rear nut on the main tree to remove the axial difference between the rear and the axial space of the bearing and the radial and axial spaces of the axial direction of the ball bearings; The radius of the double columns front of the cardiac cylindrical roller bearings in the space, continue to adjust the rear nut on the main axis and pull the spit to the rear to eliminate the axial space of the axial bearing from the front of the front To stop the bearing.
6. There are errors in the main axis component indicated in the test graph; How should I correct it? Use the brief brief diagram of another paint.
Answer: There are many mistakes. with elastic files .;
7. Try to design a main tree component. the front and rear branches.
8. In the design of the support, what basic requirements should be met?
Answer: The following requirements must be met:
1) It must have sufficient rigidity and a high quality of rigidity ratio.
2) There must have good dynamic characteristics, including a large movement impedance (dynamic rigidity) and damping; to the vibration of the thin wall.
3) The stability of heat is good and the effect of thermal deformation has less impact on the treatment accuracy of the machine tool.
4) The crumbs are not blocked, lifting is safe and it has good structural know-how.
9. What are the materials commonly used to support? What are the characteristics?
Answer: The materials commonly used in support are melting, steel plates and steel, natural granite, pre-realized steel concrete, resin concrete, etc.
(1) Fail
The cast iron casting performance is good and easy to obtain a complex structure. However, the casting requires a wooden box. The casting branch should be treated to eliminate internal stress.
(2) Steel plate welding structure
Welding branches such as steel steel and steel are characterized by short manufacturing cycles, saving wood and casting processes: support parts can be transformed into a good rigidity; High. The disadvantage of the welding structure of the steel plate is that the damping of the material of the steel plate is approximately 1/3 of the cast iron. Can use the method of improving damping to improve dynamic performance.
(3) Pré-Stress reinforced concrete
Armature concrete before stress is mainly used to make the machine on a large scale, a base and an injection of large -scale machines. When reinforced concrete is transformed into support, the configuration of the reinforcement has a greater impact on the support. Generally, the three directions must be configured with steel bars and a total prensile power from 120 to 150kn. The drawback is that it is crisp and poor resistance to corrosion and that the penetration of oil causes loose materials, so that the surface 芘 is sprayed or sprayed in plastic.
(4) Natural granite
The natural performance of granite is stable, with good precision, good resistance to vibrations, 15 times larger than steel and 5 to 6 times higher than cast iron. Easily get high jing and surface roughness by grinding and polishing.
(5) Resin concrete
The characteristics of resin concrete are: high rigidity; 40 of the cast iron, high thermal stability, the component is low in thermal deformation; ; Strong membership with metal can be integrated into metal parts as a function of different structural requirements to reduce the amount of mechanical treatment and reduce costs; cast iron bed. In short, it has high rigidity, good resistance to vibrations, water resistance, chemical corrosion and heat resistance. The drawback is that certain mechanical properties are low, but they can be integrated into the metal or in added fiber. It has a wide range of application perspectives for high-speed, high-efficiency and precision treatment tools.
10. Select the cross section of the support support according to the principles.
Answer: The principles of selection of the cross section form of the support parts are mainly in the following aspects:
1) Whether square, round or rectangular, the rigidity of the hollow section is larger than the solid, and the same section shape and the same size areas, large and fine section the section at the same time flexion rigidity and the rigidity of the torsions are high. Consequently, in order to improve the rigidity of the support parts, the cross section of the support parts should be a hollow shape, which should increase the size of the section as much as possible, and the thickness of the wall is also thin as possible under the premise of the possible process. Of course, the thickness of the wall should not be too thin, so as not to appear thin vibration.
2]The rigidity resistant to the torsion of the round cross section (ring) is good and the rigidity of the surface surface is low. Consequently, the form of cross section of the support parts mainly of the flexion must be deleted, and the direction of the flexion in the direction of its pupae must be taken in the direction of flexion.
3) The rigidity of the closed section is much higher than the rigidity of the opening section, in particular the rigidity resistant to torsion. During the design, the cross section of the support bearing must be transformed into a closed shape. However, for the needs of crumbs and the installation of certain institutions in the bed, it can sometimes not be transformed into an entirely closed form.
The tendon plate refers to the inner plate of the outer wall of the seal and the joint support. Charge.
The muscles are configured on a certain inner wall of the support part, mainly to reduce local deformation and thin vibrations, and use to improve the local rigidity of the support parts. Gluten can be vertical, horizontal and diagonal, and often organizes transactions, such as the shape and shape of rice. The ribs must be located in the curved plane of the wall board to effectively fold the curved and the deformation of the wall card less. The thickness of the gluten is generally 3.7 to 0.8 times the thickness of the bed.
11 What are the measures to improve the structural rigidity and the dynamic performance of the support parts?
(1) The main method of improving static and rigidity of the support parts is to reasonably select the materials, the shape and size of the cross section, and the thickness of the support procedure according to the Pressure of support parts. rigidity.
(2) The main methods of improving dynamic characteristics are improved depreciation characteristics. Reduction of vibrations. For welding branches, in addition to filling the reduction in concrete vibrations in the inner cavity, you can also fully use friction amortization on the junction surface to reduce vibrations. In other words, there is an area adjusted between the two welding parts. Although intermittent welding seams have reduced static rigidity, the amortization ratio increased significantly, which significantly increased dynamic rigidity. The use of the damping coating on the surface of the supported parts can obtain a more amortization ratio, which improves not only resistance to vibrations, but also offers the capacity to absorb noise radiation in the machine-tool . The use of new branches of materials, such as resin concrete materials, has high rigidity characteristics, good resistance to vibrations, small thermal deformation and chemical corruption, which can increase the rigidity of dynamics.
12. What requirements should be met in the design of the guide rail?
Answer: The different rails must meet great precision, a great loading capacity, good rigidity, small resistance to friction, stable exercise, good precision, long lifespan, simple structure, good procedural , easy treatment, assembly, adjustment and maintenance, low cost, etc. Require. The following five requirements are important:
(1) The precision of orientation and the precision of the guide are the difference between the actual movement of movement and the movement of movement given when the guidance rail is exercised in the air load or the cutting conditions. There are many factors that affect the accuracy of the advice, such as geometric accuracy and contact accuracy of the guide rail, the type of structure of the guidance rail, the rigidity of the guidance rail and the support, the thickness of the Oil film and the rigidity of the rigidity of the rigidity of the oil membrane, the thermal deformation of the guidance rail and support parts, etc.
(2) A large load capacity and good rigidity depending on the nature, direction and size of the load load, reasonably select the shape and size of the cross section of the guidance rail, so that The guidance rail has sufficient rigidity to ensure the precision of treatment of the machine tool.
(3) Precision and good precision The accuracy is mainly determined by the wear resistance of the guidance rail. The factors affecting wear resistance are guides materials, load conditions, friction properties, process methods, lubrication and protection conditions, etc.
(4) Exercise at low speed is stable when the dynamic guide track is performed at low speed or trace, the exercise must always be stable without crawling. The factors which affect the softness of the low speed exercise are the form of structure, the lubrication conditions, the static of the friction of the guide rail, the difference in the movement coefficient of the guidance rail and the transmission system of the transmission system Transmission guide.
(5) Simple structure and good know-how.
13. What is the effect of scratches and pressure cards?
Answer: The space between the guide rails is commonly used to adjust the pressure. The pressure plate is used to adjust the gap between the surface of the auxiliary rail and to withstand the disturbing torque. The pressure plate is fixed on the movement component with screws, and the space is set with scratching and pads. The embedded band is used to adjust the lateral space between the rectangular guide and the tail -shaped guide rail.
14. What are the ways to unload the guide track? What are everyone’s characteristics?
Answer: The load guidance rail is used to reduce the pressure of the guide surface and reduce resistance to friction, thus improving the abrasion resistance of the guide rail and the stability of the low speed exercise. The quality of the workbench and the room is very large.
The loading method of the guide rail is mechanical unloading, hydraulic loading and unloading of atmospheric pressure.
1. Mechanical load
The figure below is a commonly used mechanical unloading device. The size of the loading force is adjusted by screw 1 and the discs of the flat spring 2. The number of loading points is determined by the load and load coefficient on the dynamic track. Characteristics: The mechanical load loading method cannot be adjusted with the change in the external load.
2. Hydraulic discharge guide rail
Press the high pressure oil in a chain of vertical oil grooves on the Ouchette guide rail to generate burst up, share part of the external workbench load and play a role in the unloading. If the quality of the room on the workbench changes considerably, it can be adjusted to adjust the loading pressure with a static pressure guide. The difference between the rail of the hydraulic unloading guide and the static guide rail with an accelerator is that the upper buoyancy of the latter is sufficient to float all the work to form a friction of pure liquid. The dynamic pressure effect is important and it is difficult to maintain that the friction is fundamentally constant.
3. automatically adjust the loading pneumatic loading track
The basic principles of the atmospheric pressure unloading rail are illustrated in the figure.
Air compressed in the burner of the ouchette’s tunes, the small grooves formed by the roughness of the guidance rail crossing the surface of the flow of the guide rail, and the air pressure between the guide rails is distributed in shape , forming an air cushion, and the upper part and the buoyancy is discharged on the guidance rail to remove the load. The number of air cushions depends on the length and rigidity of the ouchette.
The air pressure unloading rail is compressed as an environment, without pollution and no recycling problem; The rail is not as good as the liquid static pressure rail. In order to take into account the precision and damping requirements, the friction force must be maintained constant, that is to say that the unloading constraint must automatically regulate the unloading rail of the air pressure with The external load. The automatic regulatory air pressure unloading rail has the K1 stiffness of the loading rail system automatic adjustment, which is increased that the contact rigidity K when the charging load. When the external load changes considerably, the contact and the friction between the guide rails only change slightly, ensuring that the exercise is stable and not crawled.
15. What are the measures to improve the abrasion resistance of the guidance rail?
answer:
1) Reasonable selection of materials and heat treatment of guide rails
2) The pre-right of the guidance rail
3) Good lubrication and reliable protection of the guide rail
4) Fight for any wear, less wear, uniform wear and tear can be offset after wear and tear
16. What is the difference between the blade of the CNC machine and the bedding bedding? For what?
answer:
The knife rack is an important part of the tooltip. Some parts have a lot of treatment surfaces and more knives are needed to finish, so the tower knife appears. Overall, the degree of automation of the bedding blade, most of them must be turned manually to change the knife.
CNC machines are a highly automated machine-tool. The CNC Lathe knife supports are generally divided into two categories: radiated blade and the rotating type blade.
The difference between the blade of the CNC machine and the bedding bedding is caused by the completely different degree of automation between the two.
17. What are the requirements of the automatic knife change device for the tooltip?
answer:
⑴ meet the requirements proposed in the process. The tool-tool is based on the relative movement between the tools and the room to form the surface of the room, and the surface shape and the surface position of the part are necessary to organize enough tools on the frame and the blade of the knife, and it can be practical and correctly treated the surface of each room.
刀 The installation of the knife on the library of the knife rack and the knife, when installing the tool on the knife rack, you should also be able to adjust the position of the tool with precision. To ensure the precise relative position between the tools and the parts. 刀架的运动精度将直接反映到被加工工件的几何形状精度和表而粗糙度上 ， 为此 刀架的运动轨迹必须准确 运动应平稳 ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， 刀架运转的终点到垮应准确、并且这 A specific accuracy maintains the parts to maintain the correct position of the tool for a long time.
(3) Cutting holders, knives’ library and robotics changing the knives should have sufficient stiffness. Due to the different types and sizes of the tool, the weight is very different. Advanced cutting dosage, the knife grid both the blade and the knife change robot must have sufficient stiffness.
⑷ high reliability. Since the blade frame and the automatic knife device are used in the tooltip, the number of times is large and the frequency of use is high, it must therefore be entirely attached to its reliability.
The knife change device and the automatic knife device seem to improve the automation of machine tools.
。 Easy to use and safety. The blade is one of the components of the machine often operated by workers. The knife rack should be practical for workers to install and adjust the knife.
18. What is the positioning of the end of the final face plaque? What are the characteristics?
Answer: The positioning of the dental plaque at the bitch is also called the positioning of the dental plaque at the end. high.
The dental corner of dental plaque is generally 2α equal to 90 ° and 60 °. The selection of the number of teeth Z must be determined according to the required scores and the size of the outside diameter D of the dental plaque. Generally, the outer diameter of the dental plaque is between 100 and 800 mm, and the parameter Z, the dental form angle α, the outer diameter D, the diameter of the positioning reference pores and the heavy adjustment have been standardized.
19. What is the automatic knife change device in the treatment center includes?
Answer: the automatic device for change of the treatment center for the treatment center includes the knife library and the automatic robot knife change device.
20. What are the types of knife library on the treatment center? What are their own characteristics?
Answer: The knife library is used to store the tool, which is one of the main components of the automatic sword modification device. Depending on the number of cutting tools and methods, the blade can be designed as different types. The types of knife library include the drum wheel, the chain, the lattice box and the rights library. The following introduces several forms of common blade.
(1) Library of right knives, the tool is arranged in a straight line in the blade, the structure is simple and the number of tools is limited (generally 8-12), which is used less.
(2) Deculcation library. There are less than 6 to 8 discs in the disc, up to 50-60. It is characterized by low manufacturing costs. The main components are the body of the blade and the division disc. The equipment adjustment is more practical and simple maintenance. Manufacturers of general machine tools can be done.
(3) Library of chain knives. The chain knife library is a more commonly used shape. The chain knife library is driven by an active gable.
(4) Another blade, like a library of checkered type knives.
21. What is the basis of the elected engine of the driving engine?
Answer: Selecting the blade driving engine must also meet the requirements of the Toro TF load and acceleration torque during the start of the blade library at the same time. Since the real situation is complicated that the conditions of adjustment, the nominal torque of the engine must be 1.2 ~ 1.5 times that of the TF load torque, that is to say ts> (1.2 ～ 1.5) TF.
22. How many typical knife robots? What are their own characteristics and their scope of use.
Answer: 1) Unique and simple Rabber Mobile: This robotic hand is divided into two types: robotic players only engage in online and robotics movement. The characteristics of the unique and unique mobile thief are that the structure is relatively simple.
① Robotics of robotics only is used on the occasion of the axis of the scalp and the axis of the knife and knife blade.
② The robotic robotic hand of the robotic hand is divided into two types: robotic swing shaft, parallel parallel axis and oscillating axis, and the spare axis of the tool. The axis of the pin.
2) Rotation of a double -arm mobile thief: this type of robotic hand can grasp the knife which is inserted and inserted at the same time, placed in the fuselle and the knife library compared to a single arm and a robot enrières, it , it can shorten the time of change of knife.
3) Two robotic players with both hands: this type of robotic hand is divided into two types: robotic players only make the movement in a straight line and robotics worse. The two -course manipulator of the manipulator to compose straight lines is that the tools that have been used in the knife library and the selection of a new knife can be treated when the main axis is treated. A large capacity, a more distant aspid, in particular a separate knife database.
4) Multi-hand robotic player: This type of robotic player is characterized by the ordered use of each robot.
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