Analyze the causes of deformation in the processing of mechanical parts
1.1 The internal force causes the machining accuracy of the parts to change
In 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 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 very different from the original ones, some are polygonal, and some are elliptical, with large deviations.
1.2 It is easy to produce deformation problems after heat treatment
For sheet-like mechanical parts, due to their very large long diameter, the straw hat is likely to bend 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. These deformation problems are not only caused by the changes 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, which increases the probability of deformation of the parts.
1.3 Elastic deformation caused by external force
There are several main reasons for the elastic deformation of parts in machining. One is that if the internal structure of some parts contains flakes, 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 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, which causes the part with the smaller force during cutting to shift and cause the part to deform under the action 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 influence of external force on the processing quality of mechanical parts.
There are many factors that cause deformation of mechanical parts, and different countermeasures should be adopted for different reasons. In the operation process, we must pay attention to every key point of mechanical processing and manufacturing, gradually improve the processing process, and strive to reduce the property loss to a low level.