球刃铣刀六轴数控磨削的控制模型

Control model to grind ball-nose end-mill by 6-axis numerical control

基于自主研制的嵌入式六轴数控工具磨削系统,提出了磨削铣刀球刃的六轴联动数控模型。通过分析磨削点的六坐标之间的位置关系,设计出球刃前刀面磨削的椭圆形轨迹。回转磨削砂轮使其有效磨削截面投影成椭圆形廓,控制六轴联动包络出工件上的椭圆轨迹。提出并证明了椭圆在不同方向上投影时相对应的象限内离心角关系定理,并据之进一步推导出砂轮与球刃工件之间的六轴运动坐标之间的相对位置关系的控制模型。实际磨削测试表明,该模型能有效地实现球刃铣刀的精密磨削加工控制。

Based on the embedded Computer Numerical Control（CNC） tool grinding system,a numerical control model to grind ball-nose end-mill was presented in 6-axis feed.The elliptic trace to grind the cutter＇s rake on ball-nose was designed by analyzing the position relationships among the 6 coordinates of the grinding point.The grinding wheel was swiveled to be effectively projected as elliptic shape to contour the required elliptic trace on the workpiece through the 6-axis feeding.A theorem about the eccentric-angle relationship between the ellipses of same quadrant in different projection sections was proposed and proved.Based on this theorem,the control model for relevant position in 6 coordinates between the grinding wheel and the ball-nose end-mill was deduced.The grinding test showed that the control model was effective to grind the ball-nose end-mill accurately.