It is impossible to finish all the machining contents of all surfaces in one process for the machining of mechanical parts. Do you know how many stages the machining process of mechanical parts can be divided into? Let me tell you today!
(1) Rough machining stage. Cut off most of the machining allowance of each machining surface and machine the precision datum, mainly considering to improve the productivity as much as possible.
(2) Semi finishing stage. The possible defects after rough machining shall be removed to prepare for the finish machining of the surface. It is required to achieve a certain machining accuracy, ensure a proper finish machining allowance, and complete the machining of the secondary surface.
(3) Finishing stage. In this stage, large cutting speed, small feed rate and cutting depth are used to cut off the finishing allowance left by the previous process, so that the part surface can meet the technical requirements of the drawing.
(4) Finishing stage. It is mainly used to reduce the surface roughness value or strengthen the machined surface. It is mainly used for high surface roughness requirements (Ra ≤ 0.32 μ m) Surface finish.
(5) Ultra precision machining stage. The machining accuracy is 0.1-0.01 μ m. Surface roughness value Ra ≤ 0.001 μ M processing stage. The main processing methods are: precision cutting with diamond tools, precision and mirror grinding, precision grinding and polishing.
The main purposes of dividing parts into processing stages are as follows:
(1) Ensure the processing quality. In the rough machining stage, the cutting amount is large, the cutting force generated is large, the cutting heat is large, and the clamping force required is also large. Therefore, the residual internal stress of the part and the stress deformation, thermal deformation, and stress deformation of the process system are large. The machining error generated can be eliminated step by step through semi finishing and finishing, so as to ensure the machining accuracy.
(2) Use the equipment reasonably. Equipment with high power, good rigidity, high productivity and low precision requirements for rough machining; Finishing requires high precision equipment. After dividing the processing stages, we can give full play to the advantages of the rough and finish processing equipment, and make reasonable use of the equipment.
(3) It is convenient to arrange the heat treatment process. For example, after rough machining, the residual stress of the part is large, aging treatment can be arranged to eliminate the residual stress, and the deformation caused by heat treatment can be eliminated in finish machining.
(4) It is convenient to find problems in time. Various defects of the blank, such as air hole, sand hole and insufficient machining allowance, can be found after rough machining to facilitate timely repair or decide whether to scrap, so as to avoid the discovery after the completion of subsequent processes, resulting in waste of working hours and increased production costs.
The above content is about the processing stage of mechanical parts, and I hope it can help you!