Causes of deformation of parts machining

1 The effect of internal force leads to changes in the machining accuracy of parts. When lathe processing, the effect of centripetal force is usually used. Use the three-jaw or four-jaw chuck of the lathe to clamp the parts, and then process the mechanical parts. At the same time, in order to ensure that the parts do not loosen when subjected to 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 with the increase of the cutting force, and then decreases with the decrease. This kind of operation can make the mechanical parts receive a stable force during the machining process. However, after the three-jaw or four-jaw chuck is released, the machined parts will be far different from the original ones, some are polygonal, and some are elliptical, showing a large deviation


2 There are several main reasons for the elastic deformation caused by the external force in the mechanical processing of the parts. First, if there are thin slices in the internal structure of some parts, there will be higher requirements for the operation method. Otherwise, when the operator locates and clamps the parts, it will not be able to correspond with the plan of the drawing, which will simply lead to the occurrence of elastic deformation. . The second is the unevenness of the lathe and the fixture, which causes the uneven force on both sides of the part when the part is fixed, resulting in the smaller force effect during cutting, which will appear to be translated and deformed under the effect of the force. The third is the unreasonable positioning of the parts during the machining process, 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 explain the effect of external force on the processing quality of mechanical parts. 1.3 The problem of deformation simply occurs after heat treatment. For sheet-like mechanical parts, because their long diameter is very large, the straw hat is simply bent after heat treatment. On the one hand, it will show the phenomenon of bulging in the center, 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 because the internal stress of the parts after heat treatment has changed, but also because the professional knowledge of the operators is not strong, and the structural stability of the parts is not well understood, which increases the probability of deformation of the parts.