Part machining process route refers to the production process of parts, from the blank to the finished product through the sequence of processes. In the development of the process route, in addition to the first consideration of the choice of positioning datum, should also consider the choice of surface processing methods, the degree of concentration and dispersion of the process, the division of the processing stage and the arrangement of the sequence of processes and other issues.
At present, there is not a set of general and complete process route formulation method, only some comprehensive principles are summarized, in the specific application of these principles, according to the specific conditions of comprehensive analysis.
The choice of surface processing method is to choose a reasonable set of processing methods for each surface with quality requirements on the part. In the selection, the final machining method is generally selected first according to the accuracy and roughness requirements of the surface, and then the machining method for the preparation process before finishing is determined, i.e., the machining scheme is determined. Since there are often several processing methods to obtain the same accuracy and roughness, the following factors should be considered in addition to productivity requirements and economic efficiency when selecting.
First, the nature of the workpiece material
For example, the finishing of hardened steel parts should be ground; the finishing of non-ferrous metal parts should be fine-turning or fine-boring and other processing methods, and grinding should not be used.
Second, the structure and size of the workpiece
For example, for it7 level of accuracy of the hole using broaching, reaming, boring and grinding processing methods are available. But the holes on the box generally do not need to pull or grind, but often use reaming and boring, and the holes with diameter greater than 60㎜ should not use drilling, expanding and reaming.
Three, production type
Select the CNC machining method to adapt to the production type. High productivity and stable quality processing methods should be used for mass production. For example, plane and hole are processed by broaching. Single small batch production is used to planing, milling plane and drilling, reaming, reaming holes. Another example is to ensure reliable and stable quality, to ensure a high rate of yield, in a large number of mass production using honing and super-finishing process to process more precise parts.
Fourth, the specific production conditions
Should make full use of the existing equipment and process means, the continuous introduction of new technology, technical transformation of old equipment, to tap the potential of enterprises, improve the level of technology.