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What is the reason for deformation in the shape of mechanical parts processed?


The processing performance of mechanical parts is related to the interests and safety of enterprises. Effectively reducing the probability of safety accidents while bringing economic benefits to the enterprise. In the process of adding mechanical parts, it is particularly important to avoid their deformation. Operators need to consider various factors and take corresponding measures to prevent deformation during the processing, so that the finished parts can be used normally. In order to achieve this goal, it is necessary to analyze the causes of deformation during the part processing process, find reliable measures for part deformation, and lay a solid foundation for achieving modern enterprise strategic goals.

1、 Analyzing the causes of deformation in machining mechanical parts

1. Deformation problems are prone to occur after heat treatment processing
For thin film mechanical parts, due to their large length and diameter, they are prone to bending the straw cap after heat treatment. On the one hand, due to various external factors, bulging may occur in the middle, resulting in an increase in plane deviation and bending of the parts. These deformation problems are caused by changes in internal stress of the parts after thermal treatment. Some operators do not have solid professional knowledge and do not understand the structural stability of parts, which increases the probability of parts deformation.

2. The effect of internal force causes changes in the machining accuracy of parts
When machining on a lathe, the three jaw and four jaw chucks of the lathe are used to clamp parts, and centripetal force is used to process mechanical parts. At the same time, in order to ensure that the parts do not loosen under force and reduce the impact of internal radial forces, the clamping force must be the cutting force of the machine. The clamping force increases and decreases with the increase of cutting force. This operation can stabilize the mechanical components during the machining process., After releasing the three jaw and four jaw chucks, the machined mechanical parts will be different from the original parts, some are polygonal, some are elliptical, and there will be significant deviations.

3. Elastic deformation caused by external forces
There are various reasons for elastic deformation of parts in mechanical processing. Firstly, if there are thin plates in the internal structure of certain parts, the requirements for operating methods will be high. When operators locate and clamp parts, they cannot correspond to the design of the drawing, which can easily lead to elastic deformation. Secondly, uneven lathes and fixtures result in uneven forces on both sides of the part during fixation, leading to translation and deformation of the part during cutting under the action of force. Thirdly, the unreasonable positioning of the parts during the processing reduces their stiffness and strength. Fourthly, the existence of cutting force is one of the reasons for the elastic deformation of parts. The elastic deformation caused by these different reasons indicates the impact of external forces on the machining quality of mechanical parts.

2、 Improvement measures for machining deformation of mechanical parts

In actual part processing, there are many factors that can cause part deformation. In order to fundamentally solve these deformation problems, operators need to carefully explore these factors in practical work and develop improvement measures based on the essence of the work.

1. Improving the quality of raw materials
In the specific operation process of various equipment, improving the quality of the phase embryo is a guarantee to prevent the deformation of the parts. The processed parts meet the specific standard requirements of the parts, providing assurance for the subsequent use of the components., Operators need to check the quality of different hair defects and replace defective ones from time to time to avoid unnecessary problems. At the same time, operators need to select reliable blanks based on the specific requirements of the equipment to ensure that the quality and safety of the processed parts meet the standard requirements and extend the service life of the parts.

2. Reduce cutting force
During the cutting process, closely combine the machining requirements, pay attention to the cutting angle, and reduce the cutting force. The rake angle and main deflection angle of the tool can be increased to make the blade sharp, and a reasonable tool is crucial for the size of the turning force during turning. For example, when turning thin-walled parts, if the rake angle is too large, the wedge angle of the tool will become larger, the wear rate will accelerate, and deformation and friction will be reduced. The rake angle can be selected according to different tools. The optimal front angle is 6 °~30 °; It is best to use a hard alloy tool with a front angle of 5 ° to 20 °.

3. Measures to reduce clamping force
When processing parts with poor rigidity, some measures need to be taken to increase the rigidity of the parts, such as adding auxiliary support. Attention should also be paid to the contact area between the tightening point and the parts, and different clamping methods should be selected according to the different parts. For example, when adding a thin-walled sleeve type part, elastic shaft mounting brackets can be used for clamping. It should be noted that the tightening position should be selected in the area with strong wind components. For mechanical parts with long shafts, the positioning method at both ends can be used. For parts with a very large length and diameter, it is necessary to use the method of tightening both ends together, and the method of “one end clamped, one end empty” cannot be used. In addition, when adding cast iron parts, the design of the fixture needs to be based on the principle of increasing the rigidity of the arm part. A new type of liquid bed clamping tool can also be used to effectively prevent quality problems caused by tight and irregular loading during the process of loading and unloading.

4. Use specialized fixtures to reduce clamping deformation
In the process of machining mechanical parts, the requirements for refinement are very strict. Choosing different specialized fixtures for different parts can make them less prone to displacement during processing. In addition, before processing, the staff also needs to carry out corresponding preparation work, comprehensively inspect the fixed parts, compare with the drawings, and check whether the positioning of the mechanical parts is correct to reduce clamping deformation.

5. Increase part stiffness to prevent excessive deformation
In the processing of mechanical parts, the safety performance of the parts is influenced by many objective factors. This is the phenomenon of stress shrinkage after heat treatment of the part, which will cause deformation of the part. In order to prevent deformation, technicians need to choose appropriate heat limiting treatment methods to change the stiffness of the parts. This requires the use of appropriate heat limiting treatment measures in conjunction with component performance to ensure safety and reliability. There is no obvious deformation after heat treatment.