凸轮轴数控磨削轮廓误差分析与补偿

摘要

在分析国内外磨削加工误差分析与补偿研究现状基础上，针对X 轴和C 轴两轴联动的凸轮轴数控磨削的轮廓误差提出一种轮廓误差分析和补偿策略，以提高凸轮磨削加工精度。基于凸轮轴数控磨削的X-C联动运动模型，推导了由凸轮升程表到磨削加工位移表的数学模型；指出凸轮升程与轮廓的误差变化规律在趋势上具有一致性。基于最小二乘多项式方法对多次磨削加工实验的凸轮升程误差进行一系列拟合处理，得到稳定的、可重复的凸轮升程预测误差；将升程预测误差按一定比例反向叠加到理论升程表中，采用最小二乘多项式法进行光顺，得到光顺的虚拟升程表；利用虚拟升程表对同类型凸轮轴进行磨削加工实验。实验结果表明，砂轮架速度和加速度在机床伺服响应范围之内，凸轮最大升程误差与最大相邻误差降低，凸轮轮廓表面粗糙度值满足加工要求，从而证明该误差分析和补偿方法是正确可行的。%Based on the current situations of grinding error analysis and compensation,a new con-tour error analysis and compensation method was proposed for camshaft CNC grinding in X-C axis linkage,to improve the accuracy of cam grinding.According to the camshaft grinding motion model in X-C axis linkage,the mathematical model was derived for cam lifting to grinding offset.It pointed out that the variation trends of cam lifting errors and contour errors were basically the same.Then a stable and repeatable cam lifting errors could be predicted with series fitting of cam lifting errors from multiple grinding experiments,using least square method.By inverse superposition of predicted lifting errors to theoretical lifting table in a certain proportion,the virtual lifting table could be obtained after the smoothing using least square method.Finally,the camshaft grinding experiments were applied ac-cording to the virtual table.The experimental results indicated that:the speed and acceleration of grinding carriage are basically in the response range of grinder servo,the maximum cam lifting error and the maximum adj acent error are decreased,the surface roughness satisfies with the processing re-quirements.It is proved that the error analysis and compensation methods are correct and feasible.