With the continuous development of modern manufacturing and treatment technology, CNC treatment equipment and its support CAM systems have been widely used and developed. The trajectory of the machining tool (i.e. the tooling method) generated by the CAM system is the heart of the control of the equipment processing operation. of the tool-machine and finally determines production.
This article provides a reference on how to choose the tooling method appropriate by analyzing the different characteristics of the tool method and certain factors affecting its selection, and compares process methods and tool methods during the milling process.
Click to receive the CNC 10G programming tutorial for free
1. How to walk on the knife
1f
The basic concept of the walking method
In CNC machining, the tool method refers to the trajectory planning method when the tool ends the part of the part. When processing the same part, several tool methods can meet the dimensions and precision requirements of the parts, but the processing efficiency is different.
2F
Classification of mantle methods
Cutting methods can be divided into four categories: unidirectional cut, alternative cut, circumcision cutting and composite cut. The compound knife is the first mixed knife. A one -way or reciprocal tool is used, and in terms of treatment strategy, it is a cutting tool. Therefore, depending on the different processing strategies, the tool method can be divided into online cut, circumcision and other special methods. The cutting of the lines and circumcision are generally used.
The cutting method is conducive to the maximum food machine power speed, and its cutting quality is also better than the treatment of circumcision. However, when a complex plane cavity has several bosses to train several interior contours, more knowledge of CNC programming focuses on weChat public accounts (CNC programming education) and that additional lifting actions are often generated, it is -Ede in the tool track somewhere, or on avoid interference with the boss or to bring the tool back in the remaining non-transformed area, the tool must be raised to make a certain height of the plan of Treatment, then translate to the starting point of another tool track. the cutting action.
The trajectory of the line cutting tool is mainly composed of a series of straight line segments parallel to a certain fixed direction, and the calculation is simple. Suitable for a simple cavity finish or rough treatment which eliminates large margins. As shown in Figure 1 – the reciprocity of the cutting track.
During the treatment of circumcision, the tool follows a path with similar limit profiles and consists of a set of closed curves, which can ensure that the tool maintains the same cutting state during cutting parts. Since the treatment of circumcision consists in building the current circumcision track diagram by continuously biaring to calculate the next circumcision track, the calculation is complex and takes time. Suitable for the treatment of the complex cavity and curved surfaces. As shown in Figure 2 – Track of the circular cutting tool.
Figure 1 Alternative cutting track
Figure 2 Circular cutting tool track
2. Factors that affect how to cut
1f
The shape and geometric elements of the part itself
The shape and geometric elements of the part itself include the geometry of the treatment field, the size and position of the island. This is an inherent characteristic of the part itself, an unchanging factor, but it is the fundamental factor that determines the way of cutting.
2F
Processing route
The process route is a direct process to achieve the objective of treatment and is the direct basis for choosing the tooling method. The process route determines the order of processing areas, merger and division of islands, gross treatment, treatment of semi-finishing and the division of finish treatment, etc. There are many process routes to achieve the objective, which determines the different tools of tools.
3F
Part
Part materials are also one of the factors that determine the tool cutting method. etc., thus indirectly affecting the tool cutting method. The shape and size of the white part will lead to the uniform of the distribution of the treatment allowance for each part of the room. Sizes and shapes of whites.
4F
Tightening and fixing methods of parts
The methods of tightening and fixing parts also indirectly affect the tooling method, such as the impact of the new “island” generated by the pressure plate, the impact of the fixing force on the use of the Cut, resulting in changes in the tool method, and the vibration affects the tooling method.
5F
Tool selection
The selection of tools includes the tool material, the shape of the tool, the length of the tool, the tool number, etc. The wear resistance of the tool-machine. Among them, the size of the tool (i.e. the diameter) has a direct impact on the tooling method. The selection of tools of different diameters will affect the size of the residual area, causing changes in the treatment trajectory and causing different tool methods.
6f
Selection of the processing field
During grinding, when a complex plane cavity has several bosses to form several interior contours, the lifting of additional tools is often produced for the cutting of lines; This additional tool raising the action or lengthening of the machining trajectory will seriously reduce the efficiency of the cut. Therefore, how to minimize the number of times this situation is a major problem that concerns us.
The whole cut area is divided into several sub-regions depending on the processing needs, and each sub-region is processed separately. Or divided according to the tooling method, or even ignored. This choice of area of different treatment not only reduces the number of tools without making the processing trajectory relatively longer.
3. Reasonable choice of the coat method
1f
Basic selection principle
When choosing a tooling method, you must consider two points: one is the duration of the processing time, and the other is whether the processing allowance is uniform. In general, the circumcision method is a tooling method based on the shape of the part, and the processing allowance is relatively uniform. The treatment allowance for the line cutting method is relatively uneven. If the requirements in terms of margins are ignored, greater knowledge of CNC programming is granted to an official WeChat account (CNC programming teaching), the duration of the cutting tool is generally relatively short; The tangent is increased for tool tracks, when the limit of the processing area is long (as in many islands), the track of the circumcision tool around the border has a significant impact on the treatment time Total, and the cutting tool track is generally longer than the track of the circumcision tool. The knife cutting position is easy to calculate and takes less memory, but the stab lifting is more frequent. When using an annular tool track, the ring limit must be offset and the self-interest ring is deleted several times.
2F
Select according to appearance characteristics
The parts of the part appearance determine the processing tool method. Depending on the various treatment objects, the part can be simply divided into a flat cavity and free surface. The flat cavity is generally treated in an online cutting method. Progress of the machine tool.
Free surfaces generally adopt the treatment of circumcision, mainly because curved surfaces are mainly flowing or formed from regular forms, the distribution of margins is unequal and the requirements of curved surface surface are high; Second, the treatment of circumcision and the line cutting method are compared. It can be better closer to the true form of the curved surface than to have good surface treatment characteristics.
3F
Select according to the treatment strategy
The treatment of parts is often divided into three stages of treatment: approximate treatment, semi-finishing treatment and the treatment of finish. Because the function of the machine tool is relatively simple, the limit of each step can be clearly visible in the process path, but the limit of this border under the CNC milling method is relatively vague, and it can there Having a kneader (like rough treatment the scene is good. The treatment step during CNC treatment is also necessary, but in order to reduce the tightening time and simplify the movement of the tool, etc., how to determine the Treatment contents of each step, the problems considered can be somewhat different from traditional treatment technology.
The main objective of blurring is to continue the elimination of materials per unit of time and to prepare the geometric profile of the room for semi-finishing. Therefore, the line cutting method or the composite method is often used for layer cutting. The main objective of the semi-finition is to make the form of outline of the flat part and the surface finishing allowance is uniform. Therefore, circumcision is often used. The main objective of the finish is to obtain parts with geometric dimensions, formal precision and surface quality that meet the requirements. The interior must be cut online depending on the geometric characteristics of the room, and the edges and the junctions must be cut in a circumference.
4F
Select according to the programming strategy
The main principles to determine the tooling method during programming are: the requirements to guarantee the precision of machining and the roughness of the parts; Be simplified and the number of program segments must be low, in order to reduce the programming workload. In general, for the types of flat cavities, the areas of treatment are divided by cutting lines to reduce the number of times of lifting of the knife; The size of the empty shape will affect the choice of programming. Circumcision transfer is used to convert the lines.
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.
