1.1 The internal force causes the machining accuracy of the parts to change

During lathe processing, the centripetal force is usually used to clamp the parts with the three-jaw or four-jaw chuck of the lathe, and then the mechanical parts are processed.

At the same time, in order to ensure that the parts do not loosen when under force and reduce the effect of the internal radial force, the clamping force must be greater than the mechanical cutting force. The clamping force increases as the cutting force increases and decreases with it. Such an operation can make the mechanical parts stable during the machining process. However, after the three-jaw or four-jaw chuck is released, the machined parts will be very different from the original ones, some are polygonal, some are oval, and there is a big deviation.

1.2 Deformation is easy to occur after heat treatment

For sheet-like mechanical parts, due to their large long diameter, the straw hat is prone to bending after heat treatment. On the one hand, there will be a phenomenon of bulging in the middle, and the plane deviation will increase. On the other hand, due to the influence of various external factors, the parts will be bent.

The occurrence of these deformation problems is not only due to the change in the internal stress of the parts after heat treatment, but also because the operator's professional knowledge is not solid and the structural stability of the parts is not well understood, thereby increasing the probability of deformation of the parts.

1.3 Elastic deformation caused by external force

There are several reasons for the elastic deformation of parts in machining.

First, if the internal structure of some parts contains flakes, it will have higher requirements on the operation method. Otherwise, when the operator locates and clamps the parts, it cannot correspond to the design of the drawing, which will easily lead to elastic deformation. produce.

The second is the unevenness of the lathe and the fixture, so that the force on both sides of the part is uneven when the part is fixed, resulting in the side with less force during cutting, which will translate and deform the part under the action of the force.

The third is the unreasonable positioning of the parts during the processing, which reduces the rigidity of the parts. Fourth, the existence of cutting force is also one of the reasons for the elastic deformation of parts. The elastic deformation caused by these different reasons all illustrate the influence of external force on the machining quality of mechanical parts.

In actual parts processing, there are many factors that cause parts to deform. In order to fundamentally solve these deformation problems, operators need to carefully explore these factors in actual work, and combine the essence of the work to formulate targeted improvements.