定长补偿电火花铣削加工中锥形电极的形成及稳定性

电火花铣削可以利用简单电极加工复杂工件，对铣削过程中电极损耗进行补偿是保证工件加工精度的重要措施。使用圆柱电极进行定长补偿铣削加工，加工过程中电极端面会形成一个圆锥形。为保证补偿精度，对电极圆锥形端面的形成及稳定性进行了研究。通过对定长补偿下工件被加工情况的研究，阐述了圆锥形电极形成的具体过程；并且论证了在加工进入稳定阶段以后，圆锥端面角度会基本保持在一个恒定值，研究了初始加工深度和补偿长度对锥形过渡阶段的影响；在电极直径、电参数一定情况下，验证了加工模型中锥形角度与目标加工深度的函数关系，实验结果与模型计算结果相差2.1%；最后给出了加工实例，并获得较好的加工效果。

Formation and Stability of Conical Electrode in ED-milling with Fix-length Compensation Method

Electrical discharge milling (ED-milling) with simple cylindrical electrode is applied to machining complex parts. In the process of ED-milling, the electrode wear compensation is needed to guarantee the machining precision. The bottom of cylindrical electrode will become conical during the ED-milling process with fix-length compensation method. Studies of the formation and stability of the conical bottom of electrode are conducted in order to ensure the compensation precision. Through the experiments carried out on the workpiece with fix-length compensation method, the formation process of conical bottom is illustrated. When the milling process becomes stable, the angle of conical bottom keeps almost unchanged. The influence of initial machining depth and compensation length on the transition length is also studied. Further experiments reveal that with constant electrode diameter and electrical parameters, the function relationship between the angle and machining depth in the model has been verified rational. The relative error between experimental results and theoretical results is 2.1%, and the method is proved to be effective with a machined cavity.