Precision machining is the process of changing the size or performance of a workpiece through a machine. According to the temperature state of the workpiece, it is divided into cold working and hot working. Cold working is usually carried out at room temperature and does not cause chemical changes in the workpiece. Generally speaking, the process of higher or lower than normal temperature will cause chemical changes of the workpiece is called thermal advance cnc machining. Cold working can be divided according to different machining methods. It is used for cutting and pressure machining. Thermal machining is often used for heat treatment, calcination, casting and welding.

• The production process of precision machining The production process of precision machining refers to the whole process of manufacturing products from raw materials (or semi-finished products). It is used for mechanical machining and production, including the transportation and storage of raw materials, production preparation, rough machining, parts machining and heat treatment, product assembly and debugging, painting and packaging. 1. From a hardware point of view, the machining of mechanical parts is produced by a variety of mechanical equipment, such as automobiles, milling machines, planers, grinders, broaching machines, and machining centers. The inherent machining accuracy of various equipment is different, so To achieve a certain degree of accuracy, it is necessary to select the appropriate advance cnc machining process and machining equipment when machining. 2. In terms of software, it is an operator’s technology, which involves the operating skills of various equipment operators. These skills include thorough understanding of equipment, understanding of mechanical machining, and understanding of parts and materials, etc. These skills can be gradually accumulated in daily work.
• Machining methods of precision machining 1. In order to ensure the machining accuracy, rough machining and finishing should be carried out separately. Because a large number of workpieces are subjected to cutting force, clamping force, and heat generation during rough machining, it is easy to cause surface hardening, and there is a large internal stress inside the workpiece. If the finishing and roughing are continuous, the precision parts after finishing Accuracy will redistribute with stress and will soon be lost. For some parts with high machining accuracy. Low temperature annealing or aging treatment should be carried out after rough machining and before finishing to eliminate internal stress. 2. Reasonably choose mechanical machining equipment. The main process of rough machining is to cut off most of the machining allowance, without requiring higher machining accuracy. Therefore, the rough machining machine only needs high power and low precision machining. Finishing requires more precise machine tools. Roughing and finishing on different machine tools can not only give full play to the performance of the equipment, but also extend the service life of precision machine tools. 3. Heat treatment is often required during machining. The arrangement of the heat treatment process is as follows: in order to improve the cutting performance of the metal, such as annealing, normalizing, quenching and tempering, etc., it is usually carried out before machining. In order to eliminate internal stress, such as aging treatment and quenching and tempering treatment, it is generally carried out after rough advance cnc machining and before finishing. In order to improve the mechanical properties of parts, carburizing, quenching, tempering, etc., are generally carried out after machining. If there is deformation after heat treatment, the final machining procedure must be arranged.