Research On The Machining Technology Of Flexible Envelope Gear Milling And Cutter Life

At present,the processing technology of milling herringbone gear with cutter is not mature,and there is the problem that the cutter life is too short.Therefore,the flexible envelope gear milling technology of universal multi axis CNC machine tool and universal end milling cutter provides a new method for the high precision machining of large herringbone gears in China.In this thesis,the influence of machining parameters of flexible envelope gear on the cutter life of milling cutter is studied as follows:(1)By analyzing the principle of flexible envelope milling and the coordinate system of flexible envelope milling,the theoretical model of milling process of flexible envelope milling with universal end milling cutter is established.According to the requirement of gear meshing for the accuracy of gear surface,the number of tool passes near the pitch circle of gear surface is relatively dense,and the number of tool passes near the root and the top of gear is relatively sparse.This milling method combining the accuracy of gear surface with the optimization of tool path can improve the machining efficiency of gear The service life of the tool is prolonged.(2)This thesis introduces the single error evaluation of gear tooth surface and the measurement method of tooth surface accuracy,and analyzes the main causes of tool wear.This thesis studies the relationship between tool wear and tooth surface accuracy.Taking large non undercut herringbone gear as the research object,the relationship between tool wear and tooth surface accuracy is simulated with MATLAB software.The relationship between tool wear and tooth surface accuracy is studied by changing the gear parameters.(3)The process of cross tooth indexing is established,and herringbone gear is selected for cross tooth indexing experiment.Through the comparative experiment of cross tooth machining and sequential machining of large herringbone gear,it is verified that cross tooth machining can improve the precision of flexible envelope milling herringbone gear.(4)The relationship between cutter life and machining technology of flexible envelope gear milling is studied.Taking the four axis gear milling center as the experimental prototype,the orthogonal test method is used to verify the influence of the processing parameters of the flexible envelope gear milling on the cutter life.The empirical model of cutter life is established and the significance test is carried out.The influence of two milling methods,forward milling andreverse milling,on cutter life is analyzed.Forward milling is more conducive to improving cutter life.Finally,the relationship between metal chip color and cutter life is explored.When chip color is blue or blue purple,cutter life is the best.