电火花线切割机加工自由曲面的CAD/CAM软件

CAD/CAM software for manufacturing 3-D curved surfaces using WEDM

用电火花线切割机加工自由曲面时,常规的NC编程无法精确、实时地调整电极丝与工件的相对位置。为此设计了一种CAD/CAM软件,该软件可依据被加工曲面的CAD数据,计算出加工点处电极丝的位置和姿态,并且根据加工点的法线矢量和电极丝的轴心矢量的交叉乘积决定加工点的移动方向,然后自动生成NC指令进行自由曲面的加工。利用这套软件对球面进行了加工实验。结果表明:加工得到的球面与仿真结果基本相似,加工精度取决于放电间隙及切向进给方式。

Conventional NC programming cannot guarantee precise and real-time control of the relative position between the wire electrode and the workpiece when a 3-D curved surface is machined using a wire electrical discharge machine （WEDM）. A CAD/CAM software was developed to calculate the wire electrode position and orientation at the machining point based on the CAD data of the machined surface to determine the machining point movement direction according to the cross product between the normal vector at the present machining point and the vector along the wire electrode axis with the NC commands then automatically generated to machine the 3-D curved surface. A spherical surface was machined using the software, with the finished spherical surface matching well with the design shape. The results also show that machining accuracies greatly depend on the discharge gap and the tangential feeding mode.