| Aero-engine parts have the characteristics of complex shape, high machining accuracy and difficult machined materials, which result the complicated processing technical and need to design a large number of fixtures to ensure the machining process. With the increasing number of aero-engines, the tasks of design the machining fixture for aero-engine parts is becoming increasingly heavy. At present, the designers need to first plan the fixtures structure and modeling according to the geometric information of procedure model and clamping requirements. Then, they use CAD software to complete the fixture based on the constraints and a lot of geometric elements between objects. The workload of this design process is heavy and inefficiency. Considering the similarity of aero-engine parts processing technology and fixtures, this paper proposed a rapid assembly design method rely on the assembly features according to the specific requirements of aero-engine manufacturing enterprises. This method starts with the establishment of the fixture element library and applies the recognition and matching of assembly features to complete the fixture design. Compared to other approaches, this method can fully reuse the fixture elements and greatly improve the efficiency of fixture design.The research contents of this paper are presented as follows:1) The meaning of the assembly feature is first studied to give the definition of the assembly feature for fixture element. After studying the method of the semantic representation and storage in the model, the definition of assembly feature for the fixture element model is realized by combining the elements’ structure, assembly information and drilling information.2) Based on the semantic representation and storage of the assembly features, a fixture element library is created by applying Teamcenter software and Access database, which realized the storage and management of the models and assembly feature information.3) Rapid assembly is realized after the studying of the method of assembly feature matching and constraints creation rules. The automatic punching is also realized by combining with the drilling information and analyzing the interference between the elements and other models.4) The aero-engine parts machining fixture rapid design system was developed on UG platform with C++ and UG/Open API, and it had been successfully applied in a domestic aviation manufacturing enterprise. |
