The four stages of finishing and the principles of finishing
Mechanical finishing can be effectively divided into four stages to a certain extent. They are the front surface back hole, the machining reference surface, the finishing process, and the division and processing stage. The front surface back hole should be used for parts such as the box, bracket and connecting rod. The first plane after processing holes. In this way, the machined holes can be positioned in a plane to ensure the accuracy of the position of the plane and the holes, and the processing of the holes in the plane can be facilitated.
During the machining of its reference surface, the surface of its part during the machining process shall be processed first to provide a refined reference for the subsequent processing. Called "benchmark first."
The finishing process is mainly the surface finishing process, which should be performed in the final stage of the process line during the operation. The surface finish of the processed surface is Ra 0.9um or more. After the finishing process, the velvet cloth is used for protection. , It is absolutely not allowed to directly touch the workpiece by hand or other objects, so as to avoid the finishing surface being damaged due to the transfer and installation between processes.
The surfaces of high-precision machining that require high-quality machining in the dividing processing stage are divided into three stages: rough machining, semi-finishing machining, and finishing machining. Mainly to ensure the quality of processing, is conducive to the rational use of equipment and facilitate the arrangement of heat treatment process.
The principle of mechanical finishing
1. Benchmarking principle. Should choose the design reference as possible as the positioning reference. Especially in the final completion, to ensure accuracy, we should pay more attention to this principle. This avoids position error base deviations.
2. Benchmarking principles. Should choose a unified positioning surface of the various surface treatment, as far as possible to ensure the accuracy of the position between the surface; sometimes follow the principle of common benchmarks, repeated processing.
3. As a benchmark principle. Some small machining allowances and uniform finishing processes ensure machining quality and productivity, and the precision machining surface itself serves as a foundation level.http://www.pump-casting.com