Optimization of Quality Consistency Problem of Electromechanical Component due to Manufacturing Uncertainties with a Novel Tolerance Design Method

摘要

The consistency problem caused by uncertainties in manufacturing process is a significant factor influencing the quality of electromechanical components. Currently, there are two approaches for reducing the influence of uncertainties. The first one is to improve the resistance capability of design scheme by using robust parameter design( RPD) method with nonlinear feature of controllable factors. The second one is to control the influence of uncertainties by using robust tolerance design( RTD) method with quality loss function,setting the optimal tolerance with the minimum total product loss as the objective. However, as for the electromechanical component, it is difficult to achieve nonlinear region owing to the restrictions of design parameters. In addition,the establishment of cost function in manufacturing process is also confronted by practical difficulties. In order to solve the quality consistency problem under the influence of manufacturing uncertainties,a novel tolerance design method was proposed for the electromechanical components. Through the experiment design and contribution rate analysis, key factors influencing the quality consistency were determined,and the tolerance allocation scheme was confirmed according to the consistency objective of quality.Then, quality distribution characteristics before and after the consistency optimization were analyzed and verified through the Monte Carlo stochastic simulation. The application result of electromagnetic relay proves the effectiveness of the method proposed in this paper.