Analysis of the Assembly Dimensional Chain About Automotive Exterior Parts and Optimization of Tolerance Allocation

Abstract

The assembly effect of automotive exterior parts directly affects the automobile modeling design, and the gap and flush of automotive exterior parts are essential to evaluate assembly effect of automotive exterior parts. In the assembly relation of the machine, the assembly dimensional chain consists of relevant parts size or mutual position relation. The gap and flush of automotive exterior parts can be considered as a closing link of assembly dimensional chain, while the size and position relation of parts do influence the gap and flush, that should be understood as component link of assembly link. According to the basic principle of the mathematical statistics, the assembly dimensional chain should be calculated by statistical tolerance formula. In the four parameters, there are four different optimizing methods of tolerance allocation when three of them are stable. The analysis of assembly dimensional chain of automotive exterior parts should not be adopted into earlier designing stage, but also into later producing stage.