一类开式整体叶轮五坐标数控加工刀轴矢量生成及其光顺方法的研究

Generation and the Smoothing Method of 5-axis NC Machining Tool Orientation for the Open Integrated Impeller

研究了一类开式整体叶轮五坐标数控加工刀轴矢量规划问题,分析了现有刀轴矢量生成方法的不足,借鉴动画制作中设置关键帧的思想,提出了一种新的全局光顺刀轴矢量生成方法。首先根据该类的几何特征,在满足不与相邻叶片以及被加工叶片发生碰撞干涉的前提下,设置一些关键刀轴矢量,然后采用样条函数对设置的刀轴矢量进行插值。在生成刀位文件的过程中,通过将曲面上的参数与样条函数的自变量进行某种映射,从而得到样条函数值,并将该值作为该刀位点的刀轴矢量。仿真实例表明,该方法实现了全局刀轴矢量的光顺,实现了转动速度以及加速度的连续,避免了因刀轴矢量突变而引起的机床振动,改善了曲面的加工质量。

This paper studied the planning of 5-axis NC machining tool orientation for an open integrated impeller. The problems of existed method were analyzed first and a new method for generating the smoothing tool orientation was proposed by introducing the key-frame method in the animation-making. According to the feature of the open integrated impeller, several key tool orientations were set without intersection between the tool orientation and the adjacent blades. Then these key tool orientations were interpolated by the spline function. By mapping from the surface parameter to the spline parameter, the spline function value was gained and was set at the tool orientation when generating the CL file. The simulation result shows that the method proposed herein realizes the smoothing of the overall tool orientation and the continuous of the rotating velocity and the rotating acceleration. It also avoids the shaking of the machine due to the jump of the tool orientation and the machining quality is improved.