Research On Variant Design Technology Of Aero-engine Parts Machining Fixture

Aero-engine parts have the characteristics of complex structures,high machining accuracy,difficult machined materials and etc,which result in the complicated processing technology and needing to design a large number of fixtures to ensure the machining process.The complexities of aero-engine parts also result in the complex structures and long design period of machining fixtures,which influnce the development period of aero-engine;meanwhile,frequent design changes during the developing stage lead to large amendment work on fixtures and much repeated work.With the increasing number of aero-engines,the tasks of designing fixtures for aero-engine parts are becoming increasingly heavy.It is one of the urgent issues to improve efficiency and shorten the development period of fixtures.The types of aero-engine parts are relatively fixed,and the fixture structures usually have a high similarity when the congeneric parts are machined by the same method;at the same time,the main design consideration of machining fixtures is the parameter information of clamping features in process model rather than information in other features.Considering the characteristics of fixture design,a variant design method for machining fixtures of aero-engine parts is proposed by combining template technology with variant design technology,the fixture variant design template is constructed in this paper,the new fixtures can be obtained by matching clamping fixtures both in process model and fixture variant design template.The only design basis are clamping features in process model in the design process,which simplifys the design process and improves the design efficiency.The research contents and results of this paper are presented as follows:(1)A variant design method for machining fixtures of aero-engine parts is proposed by analysing the fixture design requirement of certain aero-engine manufacturing enterprise.The information contained in fixture variant design template is analysed,and the information model of fixture variant design template is constructed based on the modeling ideology of ontology.(2)The overall demension information and relative location information in clamping features of machining process model are analysed,the fixture variant design template which includes process model template,fixture template and the relationship between them is constructed.The fixture variant design template library is designed on the Teamcenter platform,which can manage the 3D model information and parameter information.(3)The machining fixture design driven by process model is achieved.The design parameter linkage between process model and fixture variant design template can be achieved by matching clamping features both in process model and in fixture variant design template,and a new fixture can be obtained by driving fixture variant design template.(4)The machining fixture variant design system for aero-engine parts is developed on NX and Teamcenter platforms with Visual C++ and NX Open API,and it has been successfully applied in a certain aero-engine manufacturing enterprise.