CAPP System For Injection Mold Based Upon The Case Reasoning

With the advent of a knowledge-based economy, more and more enterprises recognize that knowledge is an important business capital. For the injection mold industry, process design is the intermediate links between the product design and manufacture, and the process design knowledge accumulated in this part plays an important role in the enterprise production. However, because of the characteristics about the injection mold, such as one-of-a-kind production, complex structure and other factors, make the process design more diversity and empirical, and also by the prevalence of the manual prepared by the engineers of the phenomenon. Therefore, the method of how to effectively manage and reduce the workload of engineers to enhance the competitiveness of enterprises and knowledge innovation capacity has become a question which more and more injection mold enterprises need to face.Faced with the above-mentioned problems and its characteristics, by analyzing the process design of injection mold and investigating its characteristics of Computer Aided Process Planning (CAPP), this paper presents a method of CAPP for the inject-tion mold by means of the case-based reasoning with the purpose of accumulating the process knowledge, enhancing the efficiency and standardization of the process design. The main work is as follows:1. By a detailed analysis of process, the role and characteristics about process design in the injection mold, and by analysis on CBR and its key technologies, this paper presents the feasibility of the CAPP system by means of the case-based reasoning.2. According to the features on process design of the injection mold, an expression model is built up which is based on ontology technology about the process cases in injection mold, and it can solve the "bottleneck" problem of the knowledge expression, standardize process-knowledge, and enhance their knowledge sharing and reuse.3. By the established repository on the process-knowledge ontology and the typical process, a method is put forward which can calculate the similarity of the process cases through the semantic similarity for the purpose of the retrieval of the process case. Based on the semantic similarity, such retrieval can avoid the limitations of keyword search, and improve the quality and efficiency of the system's retrieval.4. A CAPP system for the injection mold, which is based upon above method, has been developed and applied in an enterprise and proved its support on the process-cards preparation. The system can not only support the preparation of documents for master, but also provide process information, processing costs about parts information for the workshop management, project management and OA system with the purpose to achieve enterprise information integration.The main creativity of this paper is expressed in the proposed methods of CAPP for the injection mold by means of the case-based reasoning. This method uses Ontology semantic model to express the characteristics of the process cases, and defines similarity of the case through semantic similarity. A CAPP system for the injection mold, which is based upon above method, has applied in an enterprise and proved its support on the process-cards preparation.