针对汽车凸轮轴磨削加工中存在的精度问题,从提高MKS8332A数控凸轮轴磨床几何精度出发,以达到提高凸轮轴磨削精度和加工效率为目的进行了相关研究。运用多体系统运动学理论,分析并建立了该磨床磨削高精密凸轮轴过程的几何误差模型,推导出了该磨床精密加工运动约束条件方程;在多体系统理论误差参数辨识模型基础上,结合球杆仪测量原理所提出的辨识方法,能够很好地对该磨床的几何误差参数进行辨识;在此基础上研究了精密数控指令和逆变凸轮廓形的求解算法、理想数控指令的生成方法、砂轮轮廓误差的计算方法;最后给出了凸轮廓形曲线的拟合方法和刀具路线的计算方法。
This paper focused on the grinding accuracy of an automotive camshaft and executed re- lated research in order to improve the geometric accuracy of MKSS332A CNC camshaft grinder and improved the camshaft grinding accuracy and processing efficiency. A geometric error model of this grinder was analyzed and established by the utilization of multi--body system theory, and the motion constraint equation of precision machining was given. Combining the geometric error parameter iden- tification model based on multi--body system theory with a double ball bar the identification methods were put forward and could identify the geometric error parameters of the grinder well. On the basis of above,the calculation methods for precision NC instructions and inverse contour of cam,ideal NC in- structions,grinding errors were all discussed in detail. At last,a fitting method of the cam--shaped curve and the calculation method of the tool path were all given.