Research On Three Dimensional Process Planning Technology Of Key Parts Of Marine Diesel Engine Based On TCM And NX

Now computer aided design(CAD)and computer aided manufacturing(CAM) have realized three-dimensional. Acting as a bridge between CAD and CAM system, CAPP system now is mainly remain in the two-dimensional phase, before the process design,the product design model of CAD system needed to be transferred to twodimensional engineering graphics in CAPP process diagram and the two-dimensional engineering graphics need to be converted into a three-dimensional model for CAM system to generate tool path and used for processing simulation. Model conversion from three-dimensional design model to two-dimensional engineering graphics and conversion from two-dimensional engineering graphics to three-dimensional design model may cause in the process of passing information missed,which is not conducive to information integration between the systems, the efficiency of data transmission is low,which has become the bottleneck of CAD/CAPP/CAM system integration. At the same time the reuse of existing process documentation in the traditional CAPP system is low. For the above problems, the realization of the threedimensional of the CAPP system is particularly important.On the foundation of the detailed analysis of the status of 3D process design,to solve the problems of process template reuse, fast generation of new process and process model, etc., This article points out the main research content of the 3D process design system. The overall framework of 3D process design system based on TCM and NX is built with the requirement of marine diesel engine manufacturing enterprises. The main research contents and research results of this paper are as follows:In order to solve the above problems, this paper conducted the following research:1) In order to create association between the steps and the features, a coding method for machining feature was raised, In the product definition phase the code of processing characteristics in the form of product manufacturing information(PMI) is marked on the parts processing characteristics,and the PMI can be the mark be used for feature recognition.2) A structured process design method based on the manufacturing feature grouping was proposed to generate the structured process route for marine diesel key components quickly in the way of modifying the whole typical component's process route template.And this method included the flowing steps: the creation of the 3D process template/manufacturing features grouping/ the transmittal of the features information from CAD to CAPP / manufacturing features and process step connect / manufacturing features information compare and 3D-process template modification.3) Process model of reverse generating method, is studied, by Wave correlation techniques to ensure that the correlation between the steps, and on the basis of the design model by adding material to generate intermediate process model.4) Process resource matching technology is studied. Level 1 matching and statistical analysis based on the processing quality of resource evaluation process is used,and Finally secondary matching for working procedure is used to choose the appropriate machine tools.