面向装配的变动几何约束网络的生成方法研究

Methods for Generation of Variational Geometric Constraints Network for Assembly

提出变动几何约束网络概念 ,并将此网络应用于计算机辅助公差设计领域 .根据公差与配合的分类 ,定义3类变动几何约束 ;基于图论和 TTRS理论提出配合树和回路概念 ,给出配合树的性质和回路的生成规则 ;基于CAD系统中功能表面间的配合关系 ,研究了变动几何约束网络的生成方法 .通过变动几何约束网络在公差类型的生成和尺寸链的产生中的应用 。

Concept of variational geometric constraints network (VGCN) is presented, and application of the network to computer aided tolerancing is studied. On the basis of classification of tolerance and fit, three kinds of variational geometric constraints are defined; based on graph theory and TTRS theory, The concepts of mate tree and loop circuit are put forward, and the properties of mate tree and the generation rules of loop circuit are discussed. Using the mate relations between functional surfaces in CAD system, methods for generation of variational geometric constraints network are studied. The scheme is proved effective by applications of the network to generation of tolerance types and dimensional chain.