Tolerance design of electromechanical products based on self-defined approximate model

Abstract

Influenced by the uncertain factors in the manufacturing process, the output characteristics of electromechanical products inevitably deviate from the target value, resulting in the uneven quality of batch products. Generally, tolerance design based on a large number of input-output data is used to improve the quality consistency of batch products. As for electromechanical products, the output characteristics are usually obtained by the finite element method (FEM). However, FEM is so time-consuming that it is difficult to be applied to the tolerance design process. In this paper, a new tolerance design process based on approximate model is proposed. The period of tolerance design is greatly shortened. Firstly, a self-defined approximate model based on Taylor expansion principle is established. Then based on this model, the tolerance design with variable contribution rate is carried out. Finally, Monte Carlo method is used to compare the quality consistency of batch products before and after optimization. The accuracy and effectiveness of the method proposed in this paper are verified in the case of a certain type of electromagnetic relay (EMR).