1. Internal force effect leads to the change of machining accuracy of parts

When CNC precision parts are processed by lathe, the centripetal force is usually applied. The three or four jaw chuck of the lathe is used to tighten the parts, and then the machining of mechanical parts is stopped. At the same time, the clamping force should be greater than the mechanical cutting force to ensure that the parts are not loose and reduce the inner diameter force. The clamping force increases with the increase of the cutting force, and then decreases. This ability makes the mechanical parts stable in the process of machining. However, after the three claw or four claw chuck is loose, the processed parts will be very different from the original parts, some appear polygon, some appear ellipse, showing a large deviation.

2. After heat treatment, the deformation is easy to occur

Because of the large length and diameter of the mechanical parts, the straw hat detour appears after the heat treatment. On the one hand, it will show the phenomenon of bulge in the middle, and the plane offset will increase. On the other hand, due to the influence of various external elements, the parts will have circuitous phenomenon. These deformation problems are not only due to the change of internal stress of the parts after heat treatment, but also due to the lack of professional knowledge of the operators, they can not understand the structural stability of the parts, and then increase the probability of deformation of the parts.

3. Several reasons of elastic deformation caused by external force

1、 It is assumed that the internal structure of some parts contains flakes, which will have higher requirements for the operation method. Otherwise, when the operators stop positioning and clamping the parts, they can't stop corresponding to the planning of the drawing, which will simply lead to elastic deformation.

2、 It is the unevenness of the lathe and fixture that causes the uneven force on both sides of the part when it stops fixing, which leads to the translation of the side with small force effect when cutting, and the deformation of the part.

3、 It is unreasonable positioning of parts in the process of processing, which reduces the rigidity and strength of parts.

4、 The existence of cutting force is also one of the causes of elastic deformation. The elastic deformation caused by these different reasons all clarify the effect of external force on the machining quality of mechanical parts.

The above points are the causes of deformation in CNC precision parts processing. Machining function is not only related to the interests of enterprises, but also related to the safety of enterprises. It can bring economic benefits to enterprises, but also reduce the probability of accidents. So safety is very important.