针对数控凸轮轴磨床随着使用时间的增加机械零部件磨损、变形等导致加工精度可靠性下降的问题,提出了利用软件补偿数控凸轮轴磨床的几何误差以提高加工精度可靠性的方法.分析了数控凸轮轴磨床在磨削时的几何误差源,利用多体系统运动学推导出了含有几何误差项的数控凸轮轴磨床精密磨削运动学方程,给出了方程的迭代求解方法.对某数控凸轮轴磨床进行了几何误差补偿仿真与加工实验.通过对补偿前、补偿后与新机床加工件轮廓误差值的Wilcoxon秩和检验,结果表明,软件几何误差补偿技术对维持数控凸轮轴磨床加工精度可靠性具有显著作用,为几何精度下降的数控凸轮轴磨床加工出高精度的凸轮轴产品提供了一种方法,也为研究数控机床可靠性开阔了思路.
To deal with the problem of the manufacturing precision reliability decline due to the mechanical parts' wear and deformation with increasing service time, the soft compensation for the machine tool geometric errors is put forward to maintain the manufacturing precision reliability of the CNC camshaft grinder. The geometric error source is analyzed, the precise grinding kinematics equations that the errors are embodied are deduced by the multi-body kinematics, and the iteration solving manner is introduced. The geometric errors of one camshaft grinder are compensated and simulated and the manufacturing experiments are implemented. The maximum contour errors of cams manufactured by the non-compensated, compensated and new CNC camshaft grinder are tested by the Wilcoxon rank-sum test. Results show that the soft error compensation plays notable effect in maintaining the camshaft grinder's manufacturing precision reliability. It puts forward one manner to manufacture high precision products for the low precision camshaft grinder by the research results and widens train of thought for studying machine tools reliability.