五轴曲面铣削的通用表面纹理形貌建模方法

Universal Surface Texture Modeling Method for Five-axis Surface Milling

为进一步提高五轴铣削加工曲面纹理形貌仿真建模方法的通用性,同时为考虑刀具姿态角影响及分类的曲面纹理质量评定提供参考,提出了一种基于刀具结构通用参数和通用曲面刀触点坐标系的五轴铣削曲面纹理形貌建模及仿真方法。基于具有通用性的环形铣刀,采用刀具倾斜角?和旋转角θ定义刀具位姿,建立了能够适用于不同刀具及曲面的五轴铣削表面纹理过程的刀具切削刃点表达式。基于离散化思想,结合刀具切削刃点表达式,提出通过几何关系寻找瞬时扫掠四边形内工件网格点来实现曲面纹理形貌仿真。建立了平面和球面两类常用不同几何特征曲面以及不同类型自由曲面在不同刀具姿态角下表面纹理形貌仿真模型,并将平面仿真形貌分为Φ=0°、Φ≠0°两类,同时通过平面仿真时间对比验证了该仿真方法的效率更高。最后进行平面切削实验,结果表明,θ=-40°、Φ=20°及θ=15°、Φ=60°组合下实际切削与仿真表面纹理特征基本一致,同时实际切削表面纹理形貌特征与仿真分类结果一致,验证该曲面纹理形貌建模和仿真方法正确有效。

To further improve the universality of five-axis milling surface texture simulation modeling method,and to provide reference for surface texture quality assessment considering tool attitude angle and classification,a kind of five-axis milling surface texture topography simulation method was proposed with general tool parameters and general curved tool contact coordinates.The tool cutting edge expression suitable for the surface texture process of five-axis milling of different tools and surfaces was established with the tool poses defined by the tool inclination angle∅and rotation angle θ of the generality of annular milling cutter.Then,a surface texture simulation model was established with searching the grid points of the workpiece in the instantaneous swept quadrilateral through geometric relationship based on the idea of discretization and the expression of cutting edge points.Under different tool attitude angles,the surface texture simulation models of two traditional surfaces with different geometric characteristics plane,spherical surfaces and different types of freeform surfaces were established,according to the simulation results,the plane simulation morphology was divided into Φ=0°and Φ≠0°,and the efficiency of the simulation method was verified by comparing the plane simulation time.Finally,the plane cutting experiments were carried out.The results show that the actual cutting workpiece texture is basically consistent with the simulation texture morphology under the combination of θ=-40°,Φ=20°and θ=15°,Φ=60°.At the same time,the actual cutting surface texture morphology characteristics are consistent with the classification results of the simulated workpiece surface texture morphology,which further verifies the correctness of the surface texture morphology modeling and simulation methods.