PARAMETER AND TOLERANCE CONSTRAINTS MODELING FOR ASSEMBLY

摘要

Geometric parameter and tolerance design are two important phase in product design, and will affect the assembly functionality of the product. The aim of the article is to present a new method of parameter and tolerance constraints modeling for assembly. In the nominal domain, a graphical representation of the linkage of geometric constraints is termed the nominal loop circuit (NLC), which helps to formulate the stack path of parameters into parameter equations. In the variational domain, assembly stackup functions are established. In the tolerance domain, tolerance inequations are formulated. The parameter equations, tolerance inequations and assembly stackup functions constitute parameter and tolerance constraints model, which can be used to optimize of parameter and tolerance. The method is demonstrated by a gear pump design problem.