The Classification Of CNC Machine Tools
There are many classification methods for CNC machine tools, which can be roughly classified according to the type of machine tool structure, control method, china cnc machining movement method, and machine tool processing method.
1. Classification by machine tool structure
If it is classified according to the machine tool structure, then the main distinction is in the number and method of machine tool motion axes, usually two-axis linkage lathes, three-axis linkage machine tools (such as those with tool magazines are called machining centers), and four-axis linkage machine tools (which move The axis consists of X, Y, Z, A four axes), five-axis linkage machine tool (usually consists of X, Y, z, A, C or X, Y, Z, B, C five axes).
2. Classification of control methods
The control of the machine tool is usually realized by the servo mechanism, so according to the different detection positions of the machine tool, it can be divided into three types: open-loop, semi-closed-loop and closed-loop control.
- (1) Open-loop control: It does not detect any feedback device, and the information control feedback belongs to a one-way mode, so it is called an open-loop control mode. Advantages: The system is relatively stable. Disadvantages: There is no feedback device, and its accuracy is mainly controlled by the transmission accuracy of machine tool components, and the relative accuracy is not high.
- (2) Semi-closed loop control: The total detection feedback device usually controls the feedback in the rotating part of the screw of the machine tool, not in the actual position detection of the moving parts, which is called semi-closed loop control. There is an error in the machine tool screw transmission, which is difficult to eliminate, so the actual detection position is not as good as the closed-loop control of directly detecting the workpiece, but the error can be debugged and compensated, so high-precision machining can still be obtained.
- (3) Closed-loop control: The detection feedback device directly detects the workpiece, so it is called closed-loop control. Because the feedback can be detected and compensated for the entire transmission error, higher accuracy can theoretically be obtained. In practice, the stability of precision control is difficult, and there are many influencing factors.
3. The Classification By Machining Motion
CNC machine tools can be divided into point control machine tools, linear control machine tools, and contour control machine tools according to the movement mode. The differences between them are as follows.
- Point control machine tool: Point control is simply point movement, similar to drilling movement. 189 top group
- Linear control machine tool: The movement of the linear control machine tool is simple, and its movement is similar to that of a CNC grinder.
- Contour control machine tool: The movement of the contour control machine tool is complex, which can complete the three-dimensional movement in space and complete the processing of complex profile workpieces.
4. Classification By Machine Tool Processing Method
According to the machine tool processing method, it can be divided into CNC turning, CNC milling, CNC grinding, CNC drilling, CNC planing, laser wire cutting and other special machine tools, special CNC machine tools also include CNC forming machines, CNC shearing machines, CNC spark machines, CNC wire Cutting machine etc.