基于控制点变动模型的车床主轴系统误差计算与公差优化设计

摘要

为提高车床主轴系统的设计精度,提出一种基于几何要素控制点变动模型的车床主轴系统误差计算与公差优化设计方法.分析了影响主轴空间位置的前后轴承、箱体以及相互之间的装配关系,建立了误差传递关系图.根据控制点变动模型建立了车床主轴实际轴线相对于理想轴线的误差表示数学模型.利用蒙特卡洛模拟方法生成零件样本实例,采用统计分析方法计算主轴位置的概率统计结果.提出基于控制点变动模型的敏感度数值计算方法,得到了全部公差因子的敏感度.最后,采用正交试验方法,对高敏感度公差因子的公差值进行验证,获得优化的主轴系统的公差设计方案,从而验证了所提方法的正确性.%To improve the design precision of lathe spindle,based on Controlling Point Variation Model (CPVM) of geometry feature,an error calculation and optimized tolerance allocation method of lathe spindle system was proposed.The front and rear bearing,the spindle box and their assembly relationship that affected spindle rotation precision were analyzed,and the error transfer graph of spindle system was established.The mathematical model of spindle actual position relative to its nominal position was established based on CPVM.The statistical analysis results of spindle position were obtained with Monte Carlo Simulation method.The numeric method to calculate the sensitivity of tolerance factor based on CPVM was presented,and the sensitivities of all tolerance factors were calculated.The tolerance values of tolerance factor with higher sensitivity index were optimized by orthogonal test method,and optimized tolerance scheme of lathe spindle system were obtained to verify the correctness of the proposed method.