三角网格曲面环形刀五轴加工宽行距刀具路径生成方法

针对三角网格曲面五轴数控加工中普遍使用的截平面法加工行距较窄、加工效率较低的问题，提出一种可变行距的宽行加工刀具路径生成方法。首先，以三角网格数据重构为基础，提出一种基于KdTree网格区域划分的求交算法，实现了网格数据点的快速获取；然后，分析环形刀及三角网格曲面的几何特性，在无曲率干涉条件下提出通过改变侧倾角并优化前倾角使刀具有效切削半径最大化的方法，获得以加工行距最大化为优化目标的最佳刀具倾角组合；最后，结合三角网格曲面的特性建立一种环形刀刀具离散模型，并提出了相应的干涉检测与修正方法。仿真实验表明，在相同加工条件下，本文加工行距优化方法较现有方法明显增大了加工行距、提高了加工效率，而且所提出的刀具干涉与修正处理方法能有效避免局部刀底干涉及全局刀杆干涉现象的发生。

Tool Paths with Large Intervals Generation Method for Five-axis Machining of Triangular Mesh Surface Using Toroidal Cutter

Aiming at the problem of machining inefficiency caused by narrow path interval in the current five-axis CNC machining process of triangular mesh surface, a tool path generation algorithm for variable path interval in machining was proposed. Firstly, with the data reconstruction of triangular mesh, an intersection-algorithm based on KdTree mesh partition was proposed, which achieved fast grid data point acquisition. Then, with analyzing the geometric characteristics of the toroidal cutter and the triangular mesh surface, a method was proposed to maximize the effective cutting radius by changing the tilt angle and optimizing the inclination angle under the condition of no curvature interference. Finally, a discrete model of toroidal cutter was established based on the characteristics of triangular mesh surface, and the corresponding interference detection and correction method was also put forward. The simulation results showed that the optimization method of path intervals can significantly improve the machining path intervals compared with the existing methods under the same machining conditions and the presented method of checking and correcting the tool-interference can effectively avoid the local interference of cutter bottom and the global interference of cutter arbor. It can be seen that the methods proposed had upper theoretical significance and practical application value in improving the efficiency of five-axis CNC machining for triangular mesh surface.