How to improve the precision of the workpiece in vertical machining center machining?

Any processing equipment, such as processing route setting, processing program preparation, machining tool selection, machine tool problems, clamping problems and workpiece material, etc. during workpiece processing, will affect the final machining accuracy and processing efficiency of the workpiece. Vertical machining centers are used as high-precision and high-efficiency machining equipment. The commonly used methods to reduce workpiece machining errors include reducing the original error method, error compensation method, error transfer method, error grouping method, error averaging method, and error synthesis method.

First, the error synthesis method to eliminate the error of the machine tool itself is the most important method to ensure the final machining accuracy of the workpiece. The error synthesis method requires measuring the original error of each axis of the machine tool. Laser interferometer is the main detection instrument in vertical machining center because of its high measuring accuracy and flexible use.

Second, the error compensation method error compensation method is to artificially create a kind of error, to offset the process system's inherent original error, or use a raw error to cancel another original error, so as to achieve vertical machining center workpiece machining accuracy purpose. Usually by reducing the machine tool gap, improve the stiffness of the machine, using pre-load, so that the cooperation with the pre-tightening force, and eliminate the impact of the gap. It can also improve the rigidity of the workpiece and the tool to reduce the overhang of the tool and the workpiece to improve the rigidity of the process system. It is also possible to use reasonable clamping and processing methods to reduce cutting force and changes, reasonably select tool materials, increase rake angle and lead angle, and perform reasonable heat treatment on workpiece materials to improve processing performance of materials, etc. Several methods.

Third, directly reduce the original error method directly reduce the original error method is to identify the main raw error factors affect the processing accuracy, try to eliminate or reduce it directly. For example, when the vertical machining center is used for a long time, the drive system is misaligned and reversed due to natural wear.

Fourth, the error average method error average method is the use of closely linked surfaces between the mutual comparison and mutual correction, or use each other as a basis for processing, in order to achieve vertical machining center to eliminate the processing error.

V. Error Transfer Method The essence of the error transfer method is to transfer the integrated error caused by the assembly system error, force deformation and thermal deformation. If the vertical machining center carries out some hole processing, the coaxiality of the workpiece is not ensured by the precision of the spindle rotation of the machine tool, but is guaranteed by the fixture. After the spindle and the workpiece of the machine tool are connected by floating, the original error of the spindle is no longer Affect the processing accuracy, and transfer to the fixture to ensure the processing accuracy.

Sixth, the error grouping method in vertical machining center processing, due to the existence of the process blank error, resulting in the processing error of this process. The change of blank error has two main effects on this process: reaction error and positioning error.

If the above error is too large, the machining accuracy cannot be guaranteed, and it is not realistic to increase the blank accuracy or the processing accuracy of the previous process. Error grouping method can be adopted at this time, that is, the blank or the upper process size is divided into n groups according to the error size, the error of each group of the blank is reduced to 1/n, and then the relative position of the tool and the workpiece is adjusted according to each group. Adjust the positioning elements so that the size distribution range of the entire batch of workpieces can be greatly reduced. The essence of the error grouping method is to use the means to improve the measurement accuracy to compensate for the lack of processing accuracy, so as to eliminate the influence of processing error.