Digital Pre-assembly Tolerances

Nowadays the competition in the global market is becoming fiercer and fiercer, and the key strategy for enterprises to survive and develop is to develop new products with high quality and low cost in short time. So Digital Pre-assembly Technology emerges as the times require. As a key technique of Virtual Manufacturing, the purpose of digital pre-assembly technology is to offer a package of tools for product development process. The simulation and analysis of the assembly process can be conducted before the real production. Therefore, design mistakes can be reduced, develop cycle be shortened, cost be lowered and product competitive power be enhanced.Based on the analysis of the current research context of digital pre-assembly technology and computer aided tolerancing, the computer aided tolerancing is chosen to be the research objective of this thesis. The architecture of Tolerance-oriented Digital Pre-Assembly System (TDPAS) is presented firstly. According to the product assembly model of TDPAS, a database of feature templates is built to match the assembly model. The technique to import different 3D CAD models into our TDPAS is also given and UG models are used to validate the technique. The feature information of tolerance is integrated into the geometry model of product by feature identifying technique. Then the TDPAS can generate the assembly dimension chain automatically, and the tolerance analysis for the product can be done accordingly.At last, a TDPAS prototype system is developed by us to invalidate the above research results.