Abstract:

The interference may be occurred in multi-axis Numerical Control (NC) machining of free-form centrifugal impeller, and a detection method for interference was presented herein. Firstly, the offset surface of blade of the impeller was calculated, and the offset distance was the radius of cutter. The equation of cutter axis can be obtained by the given cutter location data. Then calculations were completed to judge whether there was an intersection point between the offset surface and cutter axis, if there is an intersection point, then the interference does exist. Otherwise, the minimum distance between boundary of blade and cutter axis was calculaled, if this distance is greater than the cutter radius, there is no interference, otherwise interference exists. This method has small quantity of computation, and it can greatly decrease the calculation time of computer in interference detection for large numbers of cutter location data in NC programming of impeller machining.

Key words: centrifugal impeller, detection for interference, numerical control machining, free-form surface

摘要：

针对自由曲面离心叶轮多坐标数控加工中可能出现刀具与叶片干涉的问题，提出了一种干涉检查方法。首先计算出叶片曲面的等距面，等距面的偏移距离为刀具半径，再根据所给定的刀位数据得出刀轴的表达式，然后计算该等距面与刀轴是否有交点，如果有交点则存在干涉，否则计算叶片边界线到刀轴的最小距离，若此距离大于刀具半径则无干涉，否则存在干涉。该方法计算量小，对于叶轮数控加工编程中大量刀位数据的干涉检查，可以显著地节省计算机运算时间。

关键词: 离心叶轮, 干涉检查, 数控加工, 自由曲面