Study On Open Die Forging CAPP System

The work of open die forging process planning is very complicated. The traditional way of to do it need workers with experience, is difficult to achieve standardization of the process, and is energy consuming. In order to meet the requirements of flexible and small batch production, open die forging CAPP system is developed.Based on the analysis of open die forging planning process in the company, the construction and the information flow of the Computer Aided Process Planning (CAPP) is established.In the module of information input and output, the secondary development in AutoCAD using ObjectARX was carried out to reach the goal of the generation of graphics in forging process. The system can extract information, query the database and draw the forging map automatically.The standards, methods, formulas and expert knowledge involved in process planning were saved in the database. Based on analyzing the information flow in databases, the structure relations of data which supported CAPP system were established.By introducing the technology of feature, the complex attributes and information were abstracted into features and on the basis of them a model of the features of forging parts which included information and operation of the features was founded. The model was expressed by the means of object-oriented approach, and the forging part features and operations on them were encapsulated.As an alternative tool for the process planning work done by technologists, the open die forging CAPP expert system was set up based on database. A mechanism of reasoning from the forging part model was proposed, and the way to combine similar process matching with process generation was applied. The concept of forming features was proposed and the reasoning mechanism founded on them was constructedThe main framework for the system was developed, and the functions such as information input, forging step planning, display and output of process results, process management, user management and etc. were achieved. According to the study described, the basic functions of open die forging CAPP system have been established. The software has been conducted a preliminary trial in a company and the feedback is pretty good. The modules of the system are independent with others. Therefore, it is convenient for system expansion.