Research And Development Of Process Database Of CAPP System

The process data of mechanical manufacturing is the most important technology information resource for mechanical process in manufacturing enterprise and also an important information foundation for process resources in designing process regulations, constituting produce scheme and controlling produce product. As the material resource foundation of CAPP system the process data plays an important role in realizing the function of CAPP. It is necessary to establish an effective scientific and practical process data base to create a scientific and economic CAPP system.In traditional manufacturing model the process data of enterprise is established by the need of every stage, every department and every subsystem whose relative process data base is independent. The major disadvantages of process data are as follows. For lack of unification, complete definition and expression the process data will cause plenty of data redundant; multiple storage of process data wastes lots of storage resource and lead to the difficulty in data maintenance and update. Therefore, it is much more important to study the process data base.Aiming at the real need of CAPP system the specific scheme and course of establishing process data base are put forward. On the basis of the characteristic of enterprise process data the system data base is designed according to the flow of conceptual model-logical structural design-physical design. The system structure, operating theory, whole model structure and function of every module are described. The specific scientific payoffs are as follows.1. The requirement for process data from CAPP system is put forward through analyzing the concept and characteristic of process data. The process data is classified by the management of CAPP system and the five data structures of process data and their organization descriptions are explained in detail to give the foundation for creating the process data base reasonably and effectively.2. The requirement for process data by CAPP system is put forward through analyzing the concept and characteristic of process data. While the process data being classified the five data structures and their organization description are explained in detail to give the foundation for reasonably and effectively creating the process data base.3. The conceptual model, logical model and physical model of process data base are designed according to the designing steps of data base. The transformation from local E-R model to overall E-R model and the creation of relationship model are explained in detail. Under the direction of normalization theory of data, the relational model of system is optimized. 4. The running environment and developing environment are confirmed, and lastly CAPP system is demonstrated with the example of part.