Automatic Generation Method of Assembly Tolerance in Large-Scale Assembly Design

Design of assembly tolerance and sequence of a product is one of the important factors which affect product quality and cost. However, it is influenced by many complicated factors, so there are still a lot of problems which need to be resolved compared with other research works in CAD field. By means of the product prototype in CAD system as well as the establishment of hierarchical assembly structure tree model, this paper uses the related reasoning rules to solve the assembly sequences of the product. Then on this basis, automatic generation of assembly tolerance types and construction of assembly tolerance network are realized based on the variational geometric constraints theory and polychromatic sets theory. Finally, an example is given to verify the feasibility and effectiveness of the proposed method. This paper realizes the organic combination of assembly sequence and tolerance design, effectively reduces the difficulty and complexity of assembly tolerance generation, and simplifies programming realization.