电火花加工放电通道建立过程的电磁场耦合模型

Electromagnetic Coupling Model on the Establishment of Discharge Channel in EDM

以往建立的电火花加工极间放电通道模型忽略了电磁场耦合这一关键因素,降低了准确性,故利用时域有限差分法,将极间放电通道建立过程的连续时间和空间域进行离散,并通过求解Maxwell方程实现电磁场的耦合计算。采用Matlab软件建立电火花加工放电通道形成过程的电磁场耦合模型。通过仿真发现,放电通道形成过程极短且通道直径迅速增大,在电磁场耦合效应下的放电通道直径小于忽略磁场时的直径;随着外部电压增加,放电通道中的电子和离子数量达到稳定时所经历的时间减少。

Previously,the established model of discharge channel between electrodes in EDM ignores the key factor of electromagnetic field coupling and reduces the accuracy of the model.Using the finite-difference time-domain method,the continuous time and space domain of the process of establishing the inter-electrode discharge channel are discretized,and then the Maxwell equation is solved to realize the coupling calculation of electromagnetic field.The electromagnetic field coupling model of the inter-electrode discharge channel in EDM is established on Matlab.Through simulation,it is found that the establishment of discharge channel is extremely quick and its diameter increases rapidly,moreover,the diameter of discharge channel is smaller than that of ignoring electromagnetic field coupling.With the increase of external voltage,the time that the number of electrons and ions reaches a steady state in discharge channel decreases.