整体叶轮轮毂曲面数控加工刀具轨迹规划方法

A Toolpath Planning Method for NC Machining of the Hub of an Integrated Impeller

整体叶轮轮毂曲面数控加工刀具轨迹规划是整体叶轮数控加工重要组成部分。研究了整体叶轮轮毂曲面数控加工刀具轨迹规划方法。该方法首先提取轮毂曲面的两条边界曲线,结合流线加工思想,利用垂直于叶轮轴线平面与轮毂曲面交线为一圆弧这一特点,根据弧长与残留高度关系,计算出所需刀具轨迹数量,并最终推导出了轮毂曲面刀具轨迹的参数方程。与已有方法相比,本文方法给出了明确的刀轨数目计算方法,通过参数方程可方便地进行刀位计算。在刀轴矢量计算过程中,通过设置关键刀轴矢量并采用样条曲线插值的方式,实现了刀轴矢量的全局平滑过渡并有效地避免了加工过程中的干涉碰撞。

The toolpath planning for the hub is a necessary aspect of the NC （numerical control） machining of an integrated impeller. This paper studies the toolpath planning for the NC machining of the hub of the integrated impeller. The two boundary curves of the hub are extracted first. With the flow line machining idea and considering the feature that the intersection curve of the plane is normal to the axis of the impeller and the hub is an arc, the toolpath number is computed according to the relationship between the arc and the scallop, and the parametric function of the toolpath is deduced. Compared with the existing methods, the method proposed in this paper presents the definite toolpath number and it is convenient to compute with the parametric function. In terms of the tool orientations, by inserting and interpolating the key tool orientations, the global smooth transition of the tool orientations is realized and the collision is avoided compared with the existing methods. The machining result shows that the method proposed in this paper is effective and the intended objective is achieved.