How to arrange the CNC precision machining sequence
After selecting the CNC precision machining method and dividing the process, the main content of the process route is to rationally arrange the order of these machining methods and processes. The CNC precision machining process of parts usually includes c
After selecting the CNC precision machining method and dividing the process, the main content of the process route is to rationally arrange the order of these machining methods and processes. The CNC precision machining process of parts usually includes cutting process, heat treatment process and auxiliary process. The sequence of these processes directly affects the processing quality, production efficiency and processing cost of the parts. Therefore, when designing the CNC precision machining process route, the order of cutting, heat treatment and auxiliary procedures should be reasonably arranged, and the connection problem between the procedures should be solved. Then it should be arranged according to the following methods:
1. First rough and then refined
Rough turning will cut off most of the machining allowance on the surface of the workpiece in a short time. This improves the metal removal rate on the one hand, and on the other hand satisfies the uniformity requirements of the precision turning.
Second, near first and farther away
In general, the modern parts away from the tool setting point are processed first, and the parts away from the tool setting point are processed later in order to shorten the tool movement distance and reduce the idle travel time. For turning, it is beneficial to maintain the rigidity of the blank or semi-finished product and improve its cutting conditions.
Third, the principle of crossover between inside and outside
For parts that have both an inner surface (inner cavity) and an outer surface to be processed, when arranging the processing sequence, the inner and outer surfaces should be roughed first, and then the inner and outer surfaces should be finished. Do not process a part of the surface (outer or inner surface) of the part before processing other surfaces (inner or outer surface).
Fourth, the basis first principle
Priority should be given to the surface to be used as a fine reference. This is because the more accurate the surface of the positioning reference, the smaller the clamping error. For example, when machining shaft parts, the center hole is usually processed first, and then the outer surface and the end surface are processed on the center hole as a fine reference.
Five, the principle of first, then second
The main working surface and assembly base surface of the part should be processed first, so that modern defects may be found on the main surface of the blank as early as possible. The secondary surface can be interspersed, placed on the main processing surface to a certain extent, and then before CNC precision processing.
Sixth, the principle of face first, hole second
The plane outline size of the box body and bracket parts is relatively large. Generally, the plane is processed first, and then the holes and other sizes are processed. The processing sequence is arranged in this way, and the processed plane is used for positioning, which is stable and reliable.