Study On Computer-Aided Process Planning System For Small Modulus Gear

In modern manufacturing, Aided Process Planning(CAPP) holds important theory meaning extensive practice demand. Technics design is to alalyse and mange machining information, based on these facts, compiling technics documents etc. Computer can manage plenty of data, can calculate correctly and fast, can perform all kinds of contrast and filter and selection, these function meet the need of technics design completely. Technics design is the key technic preparative of the manufacture of the product, it is the bridge of product design and product manufacture. CAPP system can not only improve the design efficiency of technics documents, but also can ensure technics design`s standardization consistency and resource share. And at the same time, CAPP is the key link of CAD, CAM and its integrate and one of the technical bases of CIMS. But now, inland CAPP drop behind CAD and CAM greatly, studies and applications on CAPP are obviously important. This thesis introduced the principle of CAPP and the classification of CAPP and the expoiture principle of CAPP step by step. Then, it illustrates some important problems and technologies, including the feature describing and modeling of part information, the layout and designing of process database, the object-oriented process decision, the automatic creating and outing of process document. The research mainly include the establish of the general structure of the CAPP system. Take the small modulus gear as an example, we should analyze the expression of its information feature and the information input method, setup the information module firtly, the layout and designing of process database, then study the process strategy principle and its realization, finally decide the form of the process document and output method. This system is CAPP which based on database entirely. With the opening structure, the databases are of the function of second development, which makes the system can be continuously improved during application by the user. The "self-studying"of the system in operation makes it continuously self-perfecting and more adaptive, then become a user`s system with the property of community, adaptive and easy use. This CAPP system is flexible, it can meet the need of different kind product plan in a corporation. The establishment of the information model starts from the design of the interface of information input. Based on the feature type of the parts information, all of the part information is input systematically and finally the information model matched the process database is created. The expression of the small modulus gear information feature is solved by means of the feature code technology which is the combination of the GT and feature technology. The synthetic strategy of the small gear process is realized by means of the combination of variant and generative process strategy. In the synthetic process strategy, CAPP system is of the advantage of high efficiency of derive methed and adaptive 0f generative method which makes the efficiency and the practicabilityof process strategy improved. The system creates process document automatically through cheching and using the data document, together with the interacting check function which makes the document creation fast and flexible.