Structural Analysis And Optimal Design Of Milling Fixture For Aeroengine Precision Forging Blades

The processing quality of its tenon determines the service life of precision forging blade to a great extent.Leaf blade body by precision forging forming,but it’s a tenon can’t,would still need a second milling.However,the characteristics of precision forging blade such as thin body,small volume and easy deformation increase the difficulty of milling the tenon of precision forging blade.Traditionally,low-melting alloy fixture are used in the processing of precision forging blade tenon.Due to its disadvantages such as long process route,low milling efficiency and serious blade body pollution,it is urgent to carry out technical research on the new precision forging blade milling fixture with adaptive process.Therefore,the following research work is carried out in this paper on the structural analysis and optimization design of precision forging blade milling fixture for aeroengines:(1)Based on the characteristics of precision forging blade tenon processing,a new precision forging blade milling fixture with multi-point flexible support is proposed.Furthermore,the mathematical model of milling cutter is established and the mechanical model of precision forging blade-fixture system is established according to elastic mechanics.Finally,according to the established model,the influence law of milling force on the tenon deformation of precision forging blade is analyzed by finite element software.(2)By combining finite element method and genetic algorithm,four key position points of precision forging blade milling fixture were optimized by taking the minimum value of the maximum deformation of the tenon of precision forging blade as the optimization objective.Finally,the optimal layout of precision forging blade milling fixture is obtained.(3)The material and structure of positioning support elements for precision forgingblade milling fixture are optimized from micro and macro aspects respectively.In the aspect of material,at the microscopic level,the positioning support elements of three different materials are compared and analyzed.In terms of structure,at the macro level,the positioning support elements of traditional structure and new splicing structure of three kinds materials are compared and analyzed.Ultimately determine what kind of structure and materials of positioning support used in milling fixture system have max rigidity.(4)Independently set up a high frequency resolution tenons distortion test system,and precision forging blades milling experiment was carried out.The effect of milling force on the tenon deformation of precision forging blade,the effect of milling fixture layout on the tenon deformation of precision forging blade and the effect of material and structure of positioning element of milling fixture on the tenon deformation of precision forging blade were studied.Finally,the accuracy of the above analysis model is verified and the blade-fixture system of the highest stiffness is obtained.