1. Datum first: that is, the datum surface is processed first. During the machining process of the parts, the appearance of the positioning reference should be processed first, so as to provide a precise reference for the processing of the subsequent process as soon as possible.
2. Divide the processing stages: Surfaces with high machining quality requirements are divided into processing stages, which can generally be divided into three stages: rough machining, semi-finishing and finishing. It is mainly to ensure the quality of processing; it is conducive to scientific application of equipment; it is convenient to arrange heat treatment procedures; and it is convenient to find blank defects.
3. Face first and then hole: For parts such as box, bracket and connecting rod, the plane should be machined first and then the hole should be machined. In this way, the processing hole can be positioned on the plane, the positional accuracy of the plane and the hole can be ensured, and the processing of the hole on the plane can be facilitated.
Fourth, finishing: the finishing of the main surface, such as grinding, honing, fine grinding, rolling, etc., should be placed at the end of the process route. The general principles for formulating the processing route of precision parts and the formulation of the processing rules for precision parts can be roughly divided into two parts. The first is to formulate the process route of parts processing, and then determine the process size of each process, the equipment and process equipment used, as well as cutting specifications, working hour quotas, etc.