Research And Development Of CAPP-NC System For Blades Based On MBD

In order to solve the problems of inconsistent data sources,low efficiency of process design and insufficient visualization of process files in process design and NC programming of blade manufacturing enterprises,this dissertation introduces MBD technology into blade process design,and develops a set of blade CAPP-NC system based on MBD on NX software platform.The main research contents and achievements of this dissertation are as follows:(1)Overall scheme design of CAPP-NC system for blades based on MBD.Based on the analysis of the traditional two-dimensional CAPP-NC system workflow,this dissertation puts forward the requirements of the MBD-based blade CAPP-NC system,constructs the system framework with five layers structure,and designs the functions of the user login module,model import module,CAPP module,NC module and database management module in detail.(2)Machining feature recognition and information extraction based on MBD design model of blade.1)The definition of MBD design model is studied.According to the classification and structure of blade,the MBD design model of blade is established.2)The processing feature recognition method based on extended attribute adjacency graph is proposed.The extended attribute adjacency graph is constructed and decomposed.Then,the processing feature in blade MBD design model can be recognized quickly and accurately through isomorphic matching of subgraphs based on matrix mapping.3)PMI information in MBD design model of blade is extracted to provide data support for the generation of machining element in process decision.(3)Blade process route decision and NC programming.1)On the basis of the generation of machining elements,an improved genetic algorithm based method of machining element sequencing is proposed.According to the process constraints,the chromosome is recombined to expand its effectiveness,and the shortest processing time is determined as the optimization objective of machining element sequencing.An example is given to verify the method.2)The generation method of MBD process model of blade is studied.Using "reverse generation" method and NX wave technology to generate blade MBD process model,the model can be automatically updated.3)This dissertation analyzes the idea of establishing NX machining template,customizes typical blade machining template,and then automatically calls machining template through NX/Open API function to generate NC code to realize rapid programming.(4)The development and running of CAPP-NC system for Blades Based on MBD.Based on the above key technology research,a set of MBD based blade capp-nc prototype system is developed by using NX secondary development tool set NX / open.Taking a certain blade as an example,the function of each module is demonstrated according to the system operation process,and the feasibility and practicability of the system are verified.The system adopts a new mode of 3D process design based on MBD technology,and the data source is unified.The seamless integration between CAPP and NC is realized.At the same time,the prototype system greatly improves the efficiency of blade process design and NC programming.In short,the system can effectively shorten the blade manufacturing cycle,reduce production costs,and help to improve the level of three-dimensional digital design and manufacturing.