General principles for drawing up process routes of precision parts
The process planning of precision parts can be divided into two steps. First of all, it is to draw up the process route of parts processing, and then determine the process size of each process, used equipment and process equipment, cutting specifications, working hours quota, etc. These two steps are interrelated and should be analyzed comprehensively.
The main task is to select the processing methods of each surface, determine the machining sequence of each surface, and determine the number of processes in the whole process.
General principles of the proposed process route
1. Machining datum first
In the machining process of parts, the surface used as the positioning reference should be machined first, so as to provide the precision reference for the subsequent processing as soon as possible. It is called “benchmark first”.
2. Division of processing stages
Surfaces with high machining quality requirements are divided into three stages: rough machining, semi finish machining and finish machining. It is mainly to ensure the processing quality, to facilitate the rational use of equipment, to facilitate the arrangement of heat treatment process, and to facilitate the detection of blank defects.
3. Face before hole
For the box, bracket, connecting rod and other parts, the plane shall be machined before the hole is machined. In this way, the hole can be machined by plane positioning, ensuring the position accuracy of plane and hole, and bringing convenience to the machining of hole on plane.
The finishing of main surfaces (such as grinding, honing, finishing rolling, etc.) shall be placed at the last stage of the process route.