CNC precision machining

CNC precision machining is exponential control processing, will need to be processed drawings programming to write process type, and then the computer connected to the CNC machining center, through programming to command the CNC machining center operation, complete precision parts processing. Precision CNC machining is mainly suitable for small batch, large quantity and many kinds of spare parts processing, CNC machining parts precision is very high, so it serves the precision parts processing in medical, communication, electronics and other industries. Six processing steps are detailed below.

1. Coarse before fine

For example, according to the rough car - semi - fine car - fine car order, gradually improve the machining accuracy. The rough lathe will cut off most of the machining allowance on the workpiece surface in a relatively short time. On the one hand, the metal cutting rate is improved, and on the other hand, the allowance uniformity of finishing car is satisfied. If the uniformity of the margin left after the coarse car can not meet the requirements of finishing, it is necessary to arrange half fine car, in order to prepare for fine car. Fine car to ensure the processing accuracy, according to the size of the drawing cut out parts outline;

2. Near first and far later

In general, from the modern part of the knife point first processing, from the point of the knife after processing, in order to shorten the tool moving distance, reduce the empty travel time. For turning, it is beneficial to keep the rigidity of blank or semi-finished product and improve its cutting conditions.

3. Inside and outside cross

For both the inner surface (inner cavity) and the outer surface of the parts need to be machined, arrange the processing sequence, should be roughed on the inner and outer surface first, then the inner and outer surface finishing. Must not be part of the parts on the surface (outer surface or inner surface) after processing, and then processing other surfaces (inner surface or outer surface).

4. Base plane first

Priority should be given to finishing surfaces used as finishing reference. This is because the more accurate the surface of the positioning datum, the smaller the clamping error. For example, axis parts processing, usually first processing center hole, and then the center hole as a fine benchmark processing outer surface and end;

5. First master last

The main working surface of the parts should be processed first, and the base surface should be assembled, so as to find the modern defects on the main surface of the blank as early as possible. Secondary surface can be interspersed, in the main surface processing to a certain degree, before the final finishing;

6. The first face after the hole

Box, bracket type parts of the plane outline size is large, generally processing plane first, then processing holes and other sizes. This arrangement of processing order, on the one hand, with processed plane positioning, stable and reliable; On the other hand, it is easy to process holes on the processed plane, and can improve the machining accuracy of holes, especially when drilling can be easy to deviate the axis of holes.