We all know that one of the indicators for testing CNC machining is machining accuracy. When we mass-produce, how to ensure CNC machining accuracy? The traditional solution is the trial cutting method. The trial cutting method is through trial cutting – measuring the size – adjusting the amount of the tool’s bite – cutting through the knife – retrying the cutting, and so on until the desired size is achieved. This method can ensure that the error is within a reasonable control range, but it is cumbersome and the production efficiency is not high, and it is mainly used for single-piece small batch production. For mass production of mobile phone casings, 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 size to achieve the purpose of ensuring batch machining accuracy. So in order to ensure the machining accuracy, which processes should be adjusted in advance?
1. Improve the rotation accuracy of the bearing of the CNC machine tool. When improving the accuracy of rotation, high-precision rolling bearings, multi-oil wedge dynamic 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 spindle journals, so that the spindle rotation accuracy is not reflected on the workpiece.
2. Control the thermal deformation of the process. The cnc machining center is a high-speed cutting processing equipment, and a large amount of heat will be generated during the processing. The heat source should be reduced and the heat source should be isolated, and the heat treatment process to eliminate internal stress should be increased; the size of the machining error reflects the machining accuracy. The lower the machining accuracy, the smaller the error and the higher the machining accuracy.
3. To reduce the transmission error of the transmission chain The transmission system should keep the number of transmission parts small, the transmission chain short, and the principle of high transmission accuracy. The use of deceleration transmission is an important way to ensure the transmission accuracy, and the closer the transmission pair is to the end, the transmission ratio should be The smaller; the precision of the end piece should be higher than that of other transmission parts.
4. Reduce the wear degree of CNC machine tools. Before the sharp wear of the tool, the tool should be worn again, the most special cutting oil should be selected for full lubrication, and the material of the tool should meet the technological requirements. The above are four methods to improve the machining accuracy of CNC machining centers, which can greatly improve the machining accuracy of CNC machining centers.
