数控刻楦中刀轴矢量平滑化及仿真

Tool-axis Smoothing Algorithm and Its Simulation in Shoe Last Carving

为了解决数控刻楦中刀轴矢量方向相对鞋楦表面法向频繁变换而造成冲击或发生干涉等问题,提出一种刀轴矢量平滑化插值方法。在确定刀触点的情况下,根据鞋楦表面的微分几何性质确定刀轴矢量方向。采用空间矢量光滑插值方法获得一系列中间位置刀轴矢量使刀轴变化较均匀;根据鞋楦误差要求,采用几何变换方法分析切削工步的起始和结束刀触点处的刀轴矢量变化状况,据此估计刻楦误差。以某规格鞋楦数控刻制过程为例对刀轴矢量光顺化方法进行仿真。结果表明,该方法可以避免刀轴方向频繁变换,并有效地提高加工精度。

In order to avoid striking or collision caused by incessant changing of tool orientation in shoe last carving, a tool orientation smoothing approach was proposed. The tool axis vectors were determined after calculating the cutter contacting points are calculated according to the differential geometry feature of shoe last surfaces. The interpolation cutter axis vectors, which turn gradually and evenly, were obtained using smoothing interpolation algorithm of spatial vector. The carving tolerance was evaluated using geometry translation on the basis of analysis for the cutter axis vectors changing between start and end points within a cutting step. The machining process was simulation after the carving machine was modeling composed of workpiece, product, cutter, clamp, and so on. The results show that this method can avoid frequent orientation change of cutter, and can improve the process precision efficiently.