Development of Simulator for Wire Electrical Discharge Machining

在本研究中，我们开发了一种电火花线切割加工的仿真方法，可以在计算机上准确地再现电火花线切割加工过程中的放电现象。模拟过程包括寻找卸料位置、去除工件和分析钢丝振动。由于模拟中的点火延迟时间、爆破力、阻尼系数和介电常数等未知参数很难通过实验测量，因此通过参数规划求解反问题得到了这些参数。采用参数规划的方法，同时搜索最优的仿真参数，使仿真结果与实验结果之间的差异最小；为了评价仿真精度，利用识别出的参数对精切削加工进行仿真。结果表明，该方法可以实现高精度的精切削仿真，仿真误差小于1.5μm，并开发了粗切削仿真程序。切割了直槽和直角槽的形状，并将模拟结果与实验结果进行了比较。通过增加进给速度和焊丝电极张力，研究了沟槽正面和侧面的直线度以及沟槽宽度的变化。模拟结果与实验结果定性吻合。

In this research, we developed a WEDM (Wire Electrical Discharge Machining) simulation method which can reproduce the discharge phenomena of WEDM on computer accurately. The simulation process consists of searching for discharge locations, removing the workpiece and analyzing wire vibration. Since unclarified parameters such as ignition delay time, explosive force, damping coefficient, and permittivity of dielectric in simulation are difficult to measure from experiments, they were obtained by solving the reverse problem using parametric programming. With the parametric programming method, optimum parameters for simulation were searched simultaneously to minimize differences between simulation results and experimental results.In order to evaluate the simulation accuracy, simulation of finish cutting was performed using the parameters identified. It was found that high precision simulation of finish cutting can be realized with the simulation error less than 1.5μm.or the next step, simulation program for rough cutting was developed. Shapes of straight grooves and right angled grooves were cut, and then simulation results were compared with the experimental results. Changes in the straightness of both frontal and lateral surfaces of the grooves and the width of the grooves were investigated by increasing the feed rate and wire electrode tension. The results of simulation coincided qualitatively with the experimental results.