Five axis linkage is the term of numerical control. Linkage means that the axis of CNC machine tool reaches a certain set point at a certain speed at the same time. Five axis linkage means that all five axes can be used. Five axis CNC machine tool is a kind of machine tool with high technology content and high precision, which is specially used for machining complex curved surface.
Five axis machine tools include vertical, horizontal and cradle type two axis NC table, NC table NC dividing head, NC table 90 axis, NC table 45B axis, NC table a axis, two axis NC spindle and so on. There are 7 kinds of five axis linkage modes in the above six categories. They all have their own characteristics. It is impossible to say which form is better, but what type of five axis machining is suitable for your products.
(1) Five axis linkage double turntable machine tool
(A) The rotation coordinate has enough travel range and good process performance
Five axis linkage 3
(B) The rigid part of the machine tool is much higher than that of the whole machine tool
(C) It is easy to develop into a machining center. It only needs to install independent tool magazine and tool changing manipulator. However, the coordinate driving power of the turntable of double turntable machine tool is large, and the coordinate conversion relationship is complex;
(2) Five axis linkage double swing head machine tool
The driving power of swing coordinate of double swing head machine tool is small, the loading and unloading of workpiece is convenient, and the relationship of coordinate transformation is simple
(3) Five axis linkage machine tool with one swing head and one turntable
The performance of a swing head and a rotary table type machine tool is between the above two
- It can effectively avoid tool interference
- For ruled surface parts, side milling can be used to form one tool
- For general solid surface, especially for large flat surface, the end face of large diameter end milling cutter can be used for machining
- It can carry out multi face and multi process processing for multiple space surfaces on the workpiece at one time
- In five axis machining, the tool can be in the most effective cutting state relative to the workpiece surface. The error distribution on the part surface is uniform
- In some cases, larger size tools can be used to avoid interference.
Current and future research focus of 5-axis CNC machining
The so-called line contact machining refers to the processing method of line contact forming in the process of machining, such as cylindrical peripheral milling, conical milling, camphor shaped hole cutting and abrasive belt grinding, etc. the characteristics of this processing method are: due to the high cutting speed at the cutting point, it can obtain higher machining accuracy, at the same time, due to the line contact molding, it has higher processing efficiency, and has developed to the corresponding task Research on line contact machining of Italian curved surface.
The use of five axis machine tool makes it easy to clamp the workpiece. No special fixture is needed in the process, which reduces the cost of the fixture, avoids multiple clamping and improves the machining accuracy of the die. Using five axis technology can reduce the number of fixtures. In addition, because the five axis machine tool can save many special tools in the processing, so the tool cost is reduced. Five axis machine tool can increase the effective cutting edge length, reduce the cutting force, improve the tool life and reduce the cost.
The use of five axis machine tool processing mold can quickly complete the mold processing, delivery, better guarantee the mold processing quality, make the mold processing easier, and make the mold modification easier. Ball end milling cutter is widely used in modern mold processing. The advantages of ball end milling cutter in mold processing are obvious. However, if the vertical machining center is used, the linear speed of the bottom surface is zero, so the bottom surface finish is very poor. If the four or five axis linkage machine tool processing technology is used to process the mold, the above shortcomings can be overcome.
Firstly, linear motor drive technology is used. The advantages of linear motor are linear drive, no drive chain, no wear, no reverse clearance, so it can achieve the best positioning accuracy. The linear motor has high dynamic performance, and the acceleration can exceed 2G. Linear motor drive also has the characteristics of high reliability and maintenance free.
The second is the use of dual drive technology. For the wide worktable or gantry type, if the middle drive is adopted, it can not guarantee that the driving force is in the center, which is easy to cause inclination and poor dynamic performance. Using double drive, double grating ruler and one driving module, the dynamic performance is perfect. A driver instruction, dual drive work at the same time, grating ruler to detect whether the two points are balanced, if not, through different instructions to achieve balance.
Machining center is generally divided into vertical machining center and horizontal machining center. The most effective machining surface of vertical machining center (three axis) is only the top surface of workpiece, and the horizontal machining center can only complete the four sides processing of workpiece with the help of rotary table. The high-grade machining center is developing towards the direction of five axis control. The five axis linkage machining center has the characteristics of high efficiency and high precision. The workpiece can be processed in one clamping. High grade CNC system can also be used for high precision machining of high-end space, such as automobile
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