基于改进田口试验法的装配公差分析

Assembly tolerance analysis based on improved Taguchi method

针对传统的田口试验法在进行装配公差分析时只适用于组成环尺寸分布为正态的情况,且计算精度较低,无法满足航空发动机装配过程中高精度、高效率、短周期等要求的问题,提出一种改进的田口试验法,通过合理选择各组成环的水平值及相应的权重因子,将传统田口试验法的适用范围扩展到组成环尺寸分布为非正态的情况,并且能够较为准确地估计出封闭环尺寸变量的前四阶矩,结合Pearson分布理论构建了新的装配公差分析模型。在理论分析的基础上,通过计算某型航空发动机涡轮转子的装配成功率,验证了该方法的有效性。

The traditional Taguchi method was only applicable to the case where the components distributions were normal in assembly tolerance analysis.Its calculation accuracy was not high enough to meet the requirements of high-precision,high-efficiency and short-cycle in the assembly process of aeroengine.Aiming at these problems,an improved Taguchi method was presented,which extended the traditional Taguchi method to handle the non-normal distribution cases by choosing the levels and weights of components reasonably.The first four moments of the assembly dimension variables were estimated accurately by the proposed method.Combined with Pearson distribution theory,a new tolerance analysis model was established.Based on the theoretical analysis,the effectiveness of the proposed method was validated by calculating the turbine rotor＇s assembly success rate of an aero-engine.