Research On Computer Aided Design And Evaluation System Of Automobile Welding Fixture

In order to reduce the automobile welding fixture design and production cycle, improve the design efficiency, solve the multi-program evaluation problem. Based on the abundant of automobile welding fixture designing experience, expounds the shortcomings of program design and evaluation.And in view of these shortcomings, this paper gives the project of design and evaluation system of automobile welding fixture based on the existing technology of CAFD and the method of program evaluation. And develops a set of practical design and evaluation system for automobile welding fixture, it is integration of design, evaluation and manufacture betterly.First of all, the automobile welding fixture was classified and concluded, on the groundwork of clearing up a mass of automobile welding fixture design data we have had. And reference on the group code technology, this paper design the automobile welding fixture naming rule. According to this, naming the automobile welding fixture. Based on the researching existing cases of similarity calculation, proposed the new method of similarity calculation.And building a automobile welding fixture case base on use of CATIA and VB database. We can make use of the fixture directly when designing the program. It is improve the series and general degree of automobile welding fixture, and build a foundation for modular design.Secondly, in view of the shortcomings of traditional fuzzy unified evaluating method, this thesis proposes a decision-making method to design the welding fixture scheme based on vague set, entropy weight coefficient and interval gray number. The multi-attribute fuzzy decision, by introducing gray system theory into the scheme, forms an automobile welding fixture decision-making model based on vague set and entropy weight coefficient. This method can be effective in reducing the loss of information to ensure the decision-making result credible, had really reflected the difference of programs, and had a higher resolution. Finally, in view of the production stage problem of repeat drawing engineering drawings, this thesis has developed an engineering drawings parametric design module of automobile welding fixture part. Using this module draw the engineering drawings of standard and general part, as long as the user inputs the design parameters and information. Will be able to drawn the parts drawing, the dimensioning, the title block the technical requirements and so on. Achieved engineering drawings parametric design, reduced the designers workload and enhanced the automobile welding fixture parts design efficiency.