The principles that CNC lathe should follow in the sequence of turning parts

After selecting the processing method and dividing the process, the next step is to arrange the sequence of the process reasonably. The machining process of parts usually includes cutting process, heat treatment process and auxiliary process. Reasonably arrange the order of cutting, heat treatment and auxiliary process, and solve the connection problem between the processes, which can improve the processing quality and production efficiency of the parts and reduce the processing cost. . To process parts on a CNC Lathe, the processes should be divided according to the principle of process concentration, and the order of parts turning processing generally follows the following principles.

1. First rough and then refined.

Follow the order of rough turning→semi-finishing turning→finishing turning to gradually improve the machining accuracy of the parts. Rough turning will cut off most of the machining allowance on the surface of the workpiece in a relatively short period of time, which not only improves the metal removal rate, but also meets the requirements for the uniformity of the finishing allowance. If the uniformity of the margin left after rough turning cannot meet the requirements of finishing, semi-finishing turning should be arranged to make the finishing margin small and even. When finishing turning, the tool moves along the contour of the part in one pass to ensure the machining accuracy of the part.

2. Near first and then far away.

The far and near mentioned here are based on the distance between the processing part and the tool change point. Usually during rough machining, the parts close to the tool change point are processed first, and the parts far away from the tool change point are processed later, in order to shorten the tool moving distance, reduce the idle travel time, and help maintain the rigidity of the blank or semi-finished product, and improve Its cutting conditions.

3. The Cnc Lathe crosses the inside and outside in the part processing.

For parts with both inner surface (inner shape, cavity) and outer surface, when arranging the processing sequence, the inner and outer surfaces should be roughed first, and then the inner and outer surfaces should be finished.

When processing the inner and outer surfaces, the inner mold and cavity are usually processed first, and then the outer surface is processed. The reason is that it is difficult to control the size and shape of the inner surface, the rigidity of the tool is relatively poor, the durability of the tool tip (edge) is easily affected by the cutting heat and is reduced, and it is difficult to remove chips during processing.

4. CNC lathes should concentrate tools during processing.

Tool concentration means that one tool is used to process the corresponding parts, and then another tool is used to process the corresponding other parts, so as to reduce the idle stroke and tool change time.

5. Numerical control lathe takes the base surface first in the part processing.

The surface used as a precision datum should be processed first, because the more accurate the surface as a positioning datum, the smaller the clamping error. For example, when machining shaft parts, the center hole is always processed first, and then the outer surface and end face are processed on the center hole as a fine reference.