(1) Selection of processing method
The selection principle of the processing method is to ensure the processing accuracy and surface roughness of the processed surface. Since there are generally multiple processing methods to obtain the same level of accuracy and surface roughness, the shape, size and heat treatment requirements of the part must be fully considered when making the actual selection. For example, IT7 level precision holes can meet the accuracy requirements by boring, reaming, grinding and other processing methods, but the holes on the box are generally bored or reamed instead of ground. Generally, reaming should be selected for small-sized box holes, and boring should be selected for larger hole diameters. In addition, productivity and economic requirements as well as the actual situation of the factory's production equipment should also be considered. The economical processing accuracy and surface roughness of commonly used processing methods can be found in the relevant process manuals.
(2) Principles for determining processing plans
The processing of more precise surfaces on parts is often achieved gradually through rough machining, semi-finishing and finishing. It is not enough to select the corresponding final processing method for these surfaces based on quality requirements. The processing plan from blank to final shape should also be correctly determined. When determining the processing plan, first determine the processing method required to meet these requirements based on the main surface accuracy and surface roughness requirements. For example, for small-diameter IT7 precision holes, when the final processing method is fine reaming, it is usually necessary to drill, ream, and rough ream before fine reaming.
