Simulation Research On Milling Stability Of Vertical Machining Center

As a common phenomenon in milling process,milling chatter severely affects the stability of milling process,and also restricts the dynamic performance of machine tools.Main reason of the chatter is that the machine tool-workpiece system impacted by the milling force has a change of the relative position,also cause the change in dynamic cutting thickness to provide energy to chatter continuely,its belong to the self-excited vibration.In this paper worked on the existing research to further study on the milling chatter,combining theoretical analysis and experimental methods to establish the chatter model of the milling system,then coming with the simulation analysis.The main research contents of this paper are as follows:1.In this paper firstly analyzed the domestic and foreign study related vertical machining center milling stability,proposed the defects of the existing study on the milling chatter,study the existing academic research as the basis for the further research.2.Through the analysis model of unit milling force,to establish the static model of milling force,and puts forward the identification method of milling force coefficient.Analysis of regenerative chatter mechanism for variable thickness dynamic cutting process in milling process,a dynamic model of milling force.3.Based on the theoretical study,design the modal test and the milling force coefficient identification test.Through the experimental modal analysis to obtain the modal parameters of the machine tool-workpiece system,transfer function etc.;through the milling force identification test and measurement of multiple sets of milling force,then use MATLAB regression analysis to obtain the milling force coefficients.The parameters obtained from the test are all the necessary conditions for the establishment of the simulation model.4.Based on theoretical model and test the acquired data,conducts the research to the stability domain of vertical machining center,and draw a vertical machining center milling stability lobe diagrams.The application of MATLAB / Simulink module establishment of chatter in milling system feedback control block diagram,and combined with the stability lobes diagram selected corresponding data simulation,to verify the theoretical model accuracy.