五坐标加工整体叶轮粗加工刀位规划

针对具有等长叶片和长短交错叶片的叶轮,通过对其气流通道的几何分析,确定了叶轮的粗加工边界和最大刀具直径.采用均匀分层法对叶轮进行粗加工刀具路径规划,针对某一层给出了之字形走刀和三角形走刀的刀具路径规划算法.计算表明,与常规的单向等参数线法相比,之字形走刀法具有计算简单、抬刀次数少的优点,三角形走刀法不但抬刀次数少,而且切削路径长度明显减小,这些将有利于叶轮粗加工效率的提高.对于某一种走刀方式,通过连接切削层上的刀位点和盖盘曲面上的对应点,确定了五轴侧铣叶轮的刀具轴线方向,避免了刀具与叶片曲面和轮毂面的干涉.最后通过实例验证了算法的可行性.

Tool-path planning for rough machining of impeller in 5-axis machine tools

Based on the geometric analysis of the air duct of 3-D impeller, the rough machining boundary and the diameter of cutter are determined, which can be used for the tool-path planning of impeller with long blades or long & short mixed blades. The zig-zag and the triangular tool-path generating algorithms are presented using equally layered strategy. The computing results indicate that the zig-zag method is easy to program with less number of tool retractions while compared with popular one-way method; and the triangular method has the characteristics of shorter length of cutting tool-path and less number of tool retractions, which is very helpful for the improving of machining efficiency. The direction of cutter axis is determined by connecting CC-point and the corresponding point of the shroud surface. The feasibility of these algorithms has been verified by actual examples.