精密机床加工误差灵敏度分析与公差设计

Sensitivity Analysis and Tolerance Design for Precision Machine Tool

加工精度是衡量精密机床加工性能的重要指标,当前针对提高加工精度的研究主要围绕误差补偿展开,缺少根据加工件的精度要求而进行机床运动轴公差设计的研究.从公差设计的角度出发,通过机床空间运动误差建模、蒙特卡洛法模拟,实现最小二乘法评价零件加工精度;利用正交试验方法,得到某项精度要求与机床运动轴误差的公差带的多组对应数据,通过多元线性回归,进行灵敏度分析;同时基于自适应遗传算法,给出了运动轴误差的公差设计方法,保证所设计的公差带在装配工艺上的可行性.通过对某精密卧式坐标镗床29项误差公差带设计,验证了该方法的可行性.

The least squares method is used to evaluate the part machining precision from the perspective of tolerance design, by using the machine tool space motion error modeling, the Monte Carlo method and the Matlab software, and the precision requirements and the machine movement axis are obtained by the orthogonal test method. Multiple sets of corresponding data of the error tolerance band, through multiple linear regression, sensitivity analysis. At the same time based on adaptive genetic algorithm, a tolerance design method for motion axis error is given to ensure the feasibility of the designed tolerance zone in the assembly process. The feasibility of the method is verified through the design of 29 error tolerance bands for a precision horizontal coordinate boring machine.