Research On Dynamic Characteristics Of Turn-milling Of Slender Shafts

With the development of civil and national defense industry,the manufacturing level of parts put forward higher requirements,the processing of high precision processing of slender shaft parts,belong to the current civil and defense industry need to solve the problem.Due to its low machining cost,high machining accuracy,high cutting efficiency,complex machining and strong ability to forming parts,the technology of turn-milling thas become one of the important cutting methods for slender shafts.Therefore,the study of cutting force and dynamics characteristics of orthogonal turn-milling have important practical significance for actual production and scientific research.First,through the research and analysis of turning milling technology,the method of orthogonal turn-milling is used to process slender shaft parts.As one of the turn milling technology,orthogonal turn milling can obtain higher machining efficiency and surface quality compared with turning technology.At present,the main cutting method for slender shaft parts is turning with various auxiliary supporting means.From the point of view of the orthogonal turn-milling kinematics analysis,established the model of chip formation in orthogonal turn-milling.Study the entrance angle,the cutting angle of side cutting edge,the entrance angle and the cutting angle of the end cutting edge in the cutting cycle.And the formulas for calculating the instantaneous cutting area is established on the basis of the entrance angle of the cutting angle,using the orthogonal experimental method to study the influence of cutting speed,cutting depth,cutter tooth number,cutter eccentricity and axial feed on the instantaneous cutting area.Two-dimensional cutting force model of orthogonal turn-milling is established.Secondly,the common dynamics problems in the cutting process were summarized.Aiming at the problem of self-excited vibration are most concerned about the established turning and milling of two degrees of freedom dynamic model,and starting from the transfer function,the characteristic root of the real and imaginary part of the cutting force and the frequency domain is deduced including the main angle and turning coincidence coefficient of turning and turn-milling chatter critical cutting stability calculation formula.Finally,the electric spindle unit by modeling and analysis,the dynamic characteristics of the electric spindle unit has great influence on the part of the finite element analysis,considering the spindle holder tool combined with the dynamic properties.The numerical values of the kinetic parameters have been picked up by the half power point method,and the critical cutting depth of regenerative chatter is obtained.