Machining of mechanical parts can not be completed in one process all the surface of all the processing content, so we know the mechanical parts processing can be divided into several stages? Let me tell you today!
(1) Roughing stage. Most of the machining allowance of each machining surface is cut off, and a fine reference is machined, mainly considering the greatest possible increase in productivity.
(2) Semi-finishing stage. Cut out the defects that may arise after rough machining, and prepare for the finishing of the surface, requiring a certain machining accuracy and ensuring the appropriate finishing allowance, while completing the machining of the secondary surface.
(3) Finishing stage. In this stage using a large cutting speed, small feed and depth of cut, remove the finishing margin left by the previous process, so that the surface of the part to meet the technical requirements of the drawing.
(4) finishing stage. Mainly used to reduce the surface roughness value or strengthen the machined surface, mainly for surface roughness requirements are very high (Ra ≤ 0.32 μm) surface processing.
(5) Ultra-precision machining stage. Machining accuracy in 0.1-0.01 μm, surface roughness value Ra ≤ 0.001 μm processing stage. The main processing methods are: diamond tool precision cutting, precision and mirror grinding, precision grinding and polishing, etc.
The parts will be divided into processing stages of the main purpose of the following points.
(1) to ensure the quality of processing. Rough machining stage cutting amount is large, the resulting cutting force is large, cutting heat, the required clamping force is also larger, so the parts residual internal stress and process system of force deformation, heat deformation, stress deformation are larger, the resulting machining errors can be gradually eliminated through semi-finishing and finishing, so as to ensure machining accuracy.
(2) Reasonable use of equipment. Rough machining requires high power, good rigidity, high productivity and low precision equipment; finishing requires high precision equipment. After dividing the processing stage, you can give full play to the strengths of roughing and finishing equipment, so that the reasonable use of equipment.
(3) facilitate the arrangement of heat treatment process. For example, after rough machining parts residual stress, can arrange aging treatment, eliminate residual stress, heat treatment caused by deformation and can be eliminated in the finishing process.
(4) to facilitate the timely detection of problems. Various defects of the blank such as porosity, trachoma and insufficient machining allowance, etc., can be found after rough machining, to facilitate timely repair or decide whether to scrap, to avoid subsequent processes to complete the discovery, resulting in a waste of man-hours, increasing production costs.