Research And Implementation Of The Stamping Die 3D CAD System Of Railway Passenger Car Parts Based On Software Design Patterns

Stamping is an important process of metal plastic forming; accordingly, stamping die occupies a position of consequence in modern manufacturing industry, and has wide range application. In railway production, as important tools for part forming of railway passenger cars, stamping die is paid more attention to its design and manufacturing. The development of CAD/CAM system is a main approach in enhancing and upgrading design and manufacture level. This dissertation deals with the development of a stamping die 3D CAD system, which is a key projects sponsored by Ministry of Railway, PR China, some new technologies such as intelligence integrated 3D product model and software design pattern are also studied in the dissertation.The first research content is about the architecture of the stamping die CAD system. On the base of analysis of stamping dies general design process, an IDEF0 based functional model and a design pattern of die structure based on the hierarchical function-structure map are built. And then, the stamping die CAD system architecture with software components and their interface bus is generated. As a software design pattern in system level, the architecture defines the CAD contents, system working flow and interactive communication. It can be reused in other specific CAD system development in stamping domain. Based on this architecture, the stamping die CAD system will support the specific functions and is convenient for maintenance, function extending and enhancing intelligent level, and we can develop it in a manner of concurrence.Secondly, the product model of stamping die is studied. On the basis of analysis of the basic demands of product model in integrated environment of CAD/CAM, a logic structure pattern of the product model is presented. And then, a feature based integrated 3D stamping die product model including design knowledge is established by means of object oriented technology. Besides expressing design result, it provides domain constraint for design process and model information for digital assembly sequence planning and simulation of stamping die, which is usually ignored in the former product models. Taking the specific structure and design process of stamping die into account, the information of workpiece is composed in die product model as product feature. Former product models merely contain mainly about the die design result, this model extends the contents of product model with the relation feature of the composed subassembly and parts and also other associated production knowledge. It is convenient for getting the associated information during intelligentized design process. The model has an open structure, and easily to be extended and maintained.In order to implement the system, variety feature in stamping dies domain is analyzed.Some key technologies of component development and system integration based on software components are discussed, such as software component function definition, implementation and management. And design pattern oriented development methods are studied. Aim at tendency of mechanical CAD system, design pattern found strategy based on feature based modeling process and CAD system development experience abstract is presented. Some software design pattern of 3D stamping die system is established according this strategy. As a particular example, punch structure pattern is presented in detail. Software reuse is paid attention to at the very start in this way of pattern mining. So, it can help to find early design idea and to reuse the design patterns.Finally, a digital assembly sequence planning approach and simulation of the stamping die is studied. A specific modular of assembly sequence planning (ASP) is developed. It is based on subassemblies partition and assembly engineering semantics. In this way, the ASP of integral stamping die is translated into ASP of every subassembly and ASP among subassemblies, and some problems existed conventional methods can be avoided. The arithmetic of ASP based on subassemblies partition and a bina...