Study On New Process Of Twin-Screw And Its Supporting System

This dissertation explores the new process of co-rotating twin-screw and its supporting system theoretically and technically. It is based on the requirements of the 863 Program named "Research and development of co-rotating twin-screw CAD system and Dalian rubber and plastics CIMS-CAPP system". The main works are shown as followings:In order to get best economic benefits and quickest time response, the advantages and shortages of existing methods for machining twin-screws are analyzed. In view of the production of co-rotating twin-screw is various and mostly in small batch, a new approach for forming cylinder helical surface with milling cutter is put forward. It presents the theoretical foundation for machining of twin-screw. Changing the diameters and fixing angles of milling cutter can meet the machining requirements of helical surface. This method has been applied in the process of manufacturing twin-screw in rubber and plastic mechanics, which simplifies the process route and shortens the prepare time in production and at the same time saves the cost and improves technical and economic benefits.According to the requirements of digitalization system scheme of twin-screw process, its structure is composed of base layer,data layer,tool layer,function layer and interface layer.The mathematic model of co-rotating twin-screw machining with milling tool is built. According to this model the tool parameters and theoretical machining error are computed and analyzed.The technique and the approach can effectively aid the designing and choosing of cylinder helical surface machining tools for co-rotating twin-screw. With VRML techniques,the process of co-rotating twin-screw machining is simulated based on the theory of machining with milling cutter, and the machining simulation theory and its key techniques are discussed.The mathematic model and computation are proved correct and feasible through cutting experiment and the model is now applied in practice.A new idea of generating the process plan system based on knowledge template is proposed according to the characteristics of twin-screw machining. The theory of the system, its key techniques and future application are discussed. A practical computer aided process plan designing and managing system is explored based the template. A co-rotating twin-screw process planning is completed using this system.The concept of prototype process is discussed, and its generation mechanism and methods for building process base are studied. Furthermore, the generation of objective process from prototype process is patterned. The method is of great importance for the flexibility and practicality of process planning system.The digitalization of process brings high demands for organization of process data. A technique of data warehouse is applied into data organizing of computer aided process planning. It can improve the flexibility and practicality of the system.