The Research Of Computer Aided Tolerance

Tolerance Designing is one important part of mechanical design, it not only influences products' quality, but also react on the manufacture cost. At the same time, Computer Aided Tolerance (CAT) is one of the core technology in integration of CAD and CAM, it is the bottle-neck of integration of design and manufacture information.This paper dissertate the general framework of Computer Aided Tolerance System, research a series of key questions such as the methods of auto-generation of dimension chain, gives out the prototype program based bn AutoCAD. The main contents of this paper are as follows:1. Research the general framework of Computer Aided Tolerance System, which can display the idea of parallel design and the goal of cost-oriented optimization.2. Study the technology about auto-generation of dimension chain, include the expression of tolerance which based on features in CAD, the theory and process of auto-generation of dimension chain.3. In order to overcome the lack of traditional Statistic methods, this paper discusses a new Statistic method, uses P-model for the calculation of dimensions in the dimension chain, improve the result's correctness.4. Research the application of Monte Carlo method for tolerance design, display the calculate formula of estimated stack-up yield and the analysis method of sensitivity to tolerance.5. Discuss the methods of cost-oriented optimization, include the model of cost-oriented optimization,. Tolerance-Cost Model, multiplex method and the method based on the process plan.6. In the end, this paper gives out the prototype program based on AutoCAD and design examples.