摘要
针对五轴加工中刀轴矢量变化过大导致加工误差较大和破坏零件表面加工质量的问题,提出采用运动学方法优化刀轴矢量。建立机床的运动学约束条件,并由此确定机床转动角速度可达区域作为刀轴矢量优化的约束条件。针对选定结构的机床,结合平底刀加工不发生过切的充要条件和被加工曲面沿行距方向的法曲率,给出初始后跟角的自动计算方法,并指出机床转动角度的变化相对于后跟角的变化是单调的。在得出切触点无干涉区域与机床转动角速度可达区域的基础上,从两个区域的交集中选取优化的刀轴矢量。如果两个区域的交集为空,则调整该点之前切触点的刀轴,从而使交集不为空。算例分析表明,所提出的运动学优化方法合理可行,能够使刀轴矢量变化均匀,充分发挥机床的性能。
Quick change in the tool orientation between neighboring contact points can never be made possible in reality due to the physical limit on the velocity and acceleration of the rotary motions of machine tool, a kinematics based method is presented in this research to solve this problem. The presented algorithm will automatically generate an interference-free inclination angle for selected machine tool, and the rotation angle will increase or decrease with the inclination angle increment. After the interference -free region and angular-velocity-feasible-region are generated, optimized tool orientation is chosen from the intersection of the two regions. If the intersection is null, backward-feasible-region will be calculated to ensure the intersection is non-null. Example shows that the method is feasible and the capability of the machine tool can be fully explored.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2009年第9期158-163,共6页
Journal of Mechanical Engineering
关键词
机床运动学
五轴加工
自由曲面
刀轴矢量优化
Kinematics of machine tool 5-axis machining Freeform surface Tool orientation optimization
