基于修正等速运动规律的自由曲面多轴加工刀轴序列优化方法

Cutter-axis sequences optimization for multi-axis machining free-form surfaces based on modified rule of constant velocity

针对自由曲面多轴加工中起始位置处刀具相对工件速度、加速度不为零导致的一定程度刚性冲击现象,提出了一种基于修正等速运动规律的刀轴序列优化方法,通过控制工件坐标系中决定刀具姿态的两个约束角,使之变化遵循修正等速运动规律,获得了切削行上平稳变化的刀轴序列,避免了由于起始位置处刀具相对工件速度、加速度不为零导致刀具不能精准到达后续加工位置的现象。算例分析表明,该方法能产生平稳且光滑的刀轴序列,可一定程度改善机床运动性能,提高加工表面质量。

To avoid the rigid impact on machined surfaces produced by the nonzero velocity and acceleration of cutter to static workpiece on initial location,this paper presents an approach to generate smooth cutter-axis sequences based on modified rule of constant velocity.By limiting the changes of two space angles determined by tool orientation using the rule of constant velocity,stable cutter-axis sequences used to machine current cutter path can be obtained.Meanwhile,this method can avoid inaccuracy cutter locations created by nonzero velocity and acceleration of initial cutter location to static workpiece.The analyzing results of experiment suggests that the method presented by this paper can produce steady and smooth cutter-axis sequences,improving the stability of machine tool running status and the quality of machined surfaces.