The process of parts processing is the process of directly changing the appearance of raw materials to make them semi-finished or finished products. This process is called technological process. It is the benchmark for parts processing and precision mechanical parts processing. The process is more complicated.
The machining process benchmarks of precision mechanical parts can be divided into categories according to different processes: casting, forging, stamping, welding, heat treatment, machining, assembly, etc. It refers to the general term of the entire part's CNC machining and machine assembly process. Others such as cleaning, inspection, equipment maintenance, oil seals, etc. are just auxiliary processes. The turning method changes the surface properties of raw materials or semi-finished products. The CNC machining process in the industry is the main process.
Contour processing of parts
1. The unmarked shape tolerance should meet the requirements of GB1184-80.
2. The allowable deviation of unmarked length dimension is ±0.5mm.
3. No fillet radius R5.
4. All unfilled chamfers are C2.
5. The sharp angle is obtuse.
6. The sharp edge is dull, and the burr and flash are removed.
Surface treatment of parts
1. There should be no scratches, abrasions and other defects that damage the surface of the part.
2. The surface of the processed thread is not allowed to have defects such as black skin, bumps, random buttons and burrs. Before painting the surface of all steel parts that need to be painted, rust, oxide scale, grease, dust, soil, salt and dirt must be removed.
3. Before rust removal, use organic solvent, lye, emulsifier, steam, etc. to remove grease and dirt on the surface of steel parts.
4. The time interval between the surface to be coated by shot blasting or manual derusting and the primer coating should not be more than 6h.
5. The surfaces of the riveting parts in contact with each other must be painted with anti-rust paint with a thickness of 30-40μm before connecting. The lap edges should be sealed with paint, putty or adhesive. The primer damaged by processing or welding must be repainted.
The choice of equipment should also be reasonable and accurate. Roughing should be carried out on a high-power machine tool, because its main purpose is to cut off most of the machining allowance, and the accuracy requirements are not so high. However, for fine processing, high-precision machine tools are required for processing. A reasonable choice of machine tools can not only ensure the accuracy of processing, but also extend the service life of the machine.
The process benchmarks for precision mechanical parts processing include positioning benchmarks, which are used by lathes or fixtures when machining on a CNC lathe. Measurement benchmark, this benchmark usually refers to the size or location standards that need to be observed during inspection. Assembly datum, this datum usually refers to the position standard of parts during the assembly process.