C-Spaceに基づいた5軸制御加工における工具姿勢の決定法

工具形状を考慮したC-Spaceの生成と安全第一加工戦略

抄録

This paper deals with the method of collision-free tool attitude determination for five-axis control machining using ball end mills. Five-axis control machining cannot only cope with the fabrication of complicated shapes, but also offers numerous advantages such as reasonable tool employment, great reduction of set-up process and so on. However, most of the present CAM systems for five-axis control machining have a lot of restrictions concerning tool collision, object shape, machining method, and so on. For that reason, if the obtained cutter location data is unsatisfactory, there is no way to modify the data, and a considerable time is consumed in order to calculate a desirable five-axis control tool path. In this paper, an effective method is proposed, which can determine a collision-free tool attitude on the basis of the original two-dimensional configuration space. Our two-dimensional configuration space shows the relationship between tool attitudes and the existence of tool collision at each cutting point. Thus, the calculation method of configuration space is at first extended, taking into the account of the tool shape data to be used such as diameters of holder and shank parts, and taper angle. Furthermore, the proposed method enables us to reflect machining strategies, that is, the user's machining intention on the basis of empirical knowledge. In this paper, the safety first machining strategy and the rapid determination of tool attitude are proposed by utilizing the Delaunay net. The method has been found effective experimentally for generating five-axis control tool paths.