电火花线切割 加工工艺设计时如何确定零件的加工余量呢？ How to determine the machining allowance of a part when designing an EDM machining process?
There are three methods for determining the EDM machining allowance.
(1) EDM wire table look-up table correction method According to production practice and experimental research, the remaining data of the blank and the process remaining data of various processes have been included in the manual. When determining the machining allowance, the required data can be obtained from the manual and then corrected in accordance with the actual situation of the factory. When checking the table, it should be noted that the data in the table are nominal values. The machining allowances on symmetrical surfaces (shaft holes, etc.) are bilateral allowances, and the machining allowances on asymmetric surfaces are unilateral. This method is currently the most widely used.
(2) EDM Empirical Estimation Method This method determines the machining allowance based on practical experience. In order to prevent waste products due to insufficient machining allowances, the estimated value is always too large, so this method is only suitable for single piece and small batch production.
(3) The EDM analysis and calculation method is a method to determine the machining allowance through calculation according to the machining allowance calculation formula and certain test data. The processing margin determined by this method is relatively economical and reasonable, but it must be carried out with comprehensive and reliable test data and advanced calculation methods, so it is currently less used.
When determining the EDM machining allowance, the total machining allowance and the process allowance must be determined separately. The size of the total machining allowance is related to the precision of the selected blank manufacturing. When the table machining method is used to determine the machining allowance of the process, the machining allowance of the roughing process should not be determined by referring to the table. Instead, the total machining allowance is subtracted from each process allowance. If the amount is too small, the total machining allowance should be increased; if it is too large, the total machining allowance should be appropriately reduced to avoid waste.