We all know that one of the indicators for testing NC machining is machining accuracy. When we mass produce, how to ensure cnc machining accuracy? The traditional scheme is the trial cutting method. The trial cutting method is through trial cutting – measuring size – adjusting the cutting amount of the tool – cutting – cutting again and again until the required size is reached. This method can ensure that the error is within a reasonable control range, but it is cumbersome and inefficient. It is mainly used for single piece small batch production. For mass production of mobile phone shells, while maintaining high CNC machining accuracy, it is necessary to adjust the relative positions of machine tools, fixtures, workpieces and tools to obtain the required dimensions to ensure the mass machining accuracy. What processes should be adjusted in advance to ensure the machining accuracy?
1、 Improve the rotary accuracy of the bearing of CNC machine tools. In order to improve the accuracy of the rotation, high-precision rolling bearings, multi oil wedge hydrodynamic bearings and hydrostatic bearings can be selected. At the same time, improve the accuracy of bearing accessories, such as improving the machining accuracy of box support holes and main shaft journals, so that the spindle rotation accuracy is not reflected on the workpiece.
2、 Control the thermal deformation of the process. CNC machining center is the processing equipment of high-speed cutting, which will generate a lot of heat during the processing. It is necessary to reduce the heating of heat sources and isolate heat sources, and increase the heat treatment process to eliminate internal stress; The size of machining error reflects the level of machining accuracy. The larger the error, the lower the machining accuracy, and the smaller the error, the higher the machining accuracy.
3、 To reduce the transmission error of the transmission chain, the transmission system should keep the principle of fewer transmission pieces, shorter transmission chain and higher transmission accuracy. Speed reduction transmission is an important way to ensure transmission accuracy, and the closer the transmission pair is to the end, the smaller its transmission ratio should be; The accuracy of the end piece shall be higher than that of other transmission parts.
4、 Reduce the tool wear of CNC machine tools. Before the sharp wear of the tool, the tool should be re worn, the most special cutting oil should be selected for full lubrication, and the tool material should meet the process requirements. The above are four methods to improve the machining accuracy of CNC machining centers, which can greatly improve the machining accuracy of CNC
