Research And Application Of Discrete Product Design Change

The core problem which assembly process must resolve, is how to make parts contitute of product and meet quality need. At present, CAPP which aims at parts is popular, but system which can aid assembly process to plan is seldom. Because of the close ralationship between assembly process and human activity, there is much subjectivity, incertitude and empiricism during manufacturing. Assembly process need treat with the relationship of all states of parts, so system is more complex than CAPP which only aims at single part.Firstly, this paper analyses the assembly process of typical product, summarizes and abstracts assembly model of small-medium batches of multiple complex products; then, it researches computer aided assembly process planning methods; finally, based case assembly task plan as systemetic solution is introduced.main characters include two aspects: firstly, excellent process cases are reused, during process planning procedure which can help engineers to check similar cases according to part serial number,product symbol, characteristics of structure and attribute of function etc as the guidance of the new process. It not only improves work effectivity, but also makes excellent process as cases be inheritted, which also enhances the standard of process planning.Secondly, realized network chart support during assembly process planning.Every point in network chart is an assembly point, technologists can establish restricting relation between assembly points according to the order of assembly,and the network chart of assembly.Then,the macroscopical layout of assembly process is accomplished.After that, technologists can make working procedure planning and designing for every assembly point,thus,assembly process designing of the entire product.In the designing course, the whole planning performing drives by task management. Product assembly tasks play main roles, sub-tasks finished assembly process planning of parts.In allusion to the aforementioned assembly process designing model,this paper expatiates the work principle and the actualizing theory. Designing in the mass and modeling for the software system are made,and also realizes fuction structure designing, programme logic flow designing and database designing. As a result,a case-based CAAPP is carried out. This system has been put into the practice of assembling a truck production of C model for a heavy-duty motorcar company.