基于Z-buffer的组合曲面圆环面刀具加工方法

Machining of Composite Surface Based on Z-buffer Method with Torus Tools

为解决组合曲面五轴加工问题提出一种基于计算机图形学Z-buffer技术的圆环面刀具刀位生成算法。首先借助Z-buffer技术确定刀位计算的检测区域,然后在保证圆环面刀具和检测区域不干涉的前提下调整刀位,使刀具端面和模型曲面充分贴合,从而得到更宽的加工行宽。算法充分利用计算机硬件的快速高效性,直接对加工检测区域内的点进行读取和存贮,避免复杂的搜索和迭代过程。算法过程中集成对刀位干涉的检测和避让,可直接生成无干涉的刀位数据。刀位算法计算过程使用曲面的多面体信息,适用于以裁剪曲面为元素的组合曲面模型的无干涉刀位的计算。针对某组合曲面模型进行刀位计算和仿真,仿真结果相比传统的球头刀加工算法效率提高了10倍。最后对生成的刀轨进行了实际加工试验验证。

A new tool path generation method based on Z-buffer method is proposed for composite surface machining by using torus cutters. Firstly, the examining area is determined by means of Z-buffer method. Then interference-free tool positions with optimal machining strip width are obtained by matching the end surface of the torus cutter to the model surface as close as possible. The discretized points within the examining area are efficiently read in and stored directly by the computer hardware; no extra searching and iterative methods are needed. Interference checking and avoiding methods are combined with the adjusting process of the cutter, so the tool positions generated are interference-free. Triangulated model is used in the newly developed method which is particularly suitable for tool path generation of composite surface. The new method is used to generate tool path for a mold surface and the result shows that, comparing to traditional machining method with ball end cutter, the new method raises efficiency by ten times. Finally, simulation and cutting test are performed .