Research On Vibration Reduction Mechanism And Vibration Control Of Variable Damping Vibration Damping Boring Bar

During the deep hole boring process,the boring bar is in a cantilevered state and its stiffness will be reduced,which will easily generate vibration during the machining process,and this situation will have a serious impact on the machining quality and efficiency.Therefore,the vibration control of the boring process is a key problem that needs to be solved.In order to improve the surface quality of the boring parts,it is important to monitor the state of the boring bar and control the vibration in real time during the machining process.In this paper,we propose a variable damping vibration damping boring bar with corresponding functional integration of the boring tool.By analyzing the self-excited vibration of the boring bar during the boring process,the vibration law of the boring bar during the machining process is obtained.The negative damping effect caused by friction and velocity feedback is investigated,and it is concluded that the negative damping effect is the main cause of the vibration of the boring bar.The boring force model of the boring bar under vibration is analyzed by MATLAB software,and the results of the analysis conclude that different mass,stiffness and damping in the subsystem will affect the vibration,but the comprehensive consideration of damping is easier to adjust compared with the other two parameters,so this paper selects the variable damping damping boring bar for the design.The structure of the variable damping vibration damping boring bar is designed,the dynamics model of the bar is analyzed,and the structure of the variable damping vibration absorber is introduced.The effects of stiffness,mass and damping on the performance of the absorber are analyzed,and the results yield that the absorber stiffness is inversely proportional to the overhang,the absorber mass is inversely proportional to the absorber stiffness,and the absorber voltage is directly proportional to the damping.The static and dynamic simulations of the magnetic field generated by ANSYS simulation software show that the force on the mass increases gradually as the distance between the mass block and the excitation coil decreases and the supply voltage to the excitation coil increases,and the vibration decay rate also increases.The technical requirements of the sensing and control system are proposed through the design of the sensing and control system of the vibration-damping boring bar.The workflow and hardware selection of the sensing and control system are introduced,then the vibration state sensing and vibration control processes are analyzed respectively,and finally the Lab VIEW-based system platform is built.The functions of the platform are used to realize the system management,data acquisition,data playback,signal analysis,and vibration control of the variable damping boring bar.The performance test experiment of the variable damping vibration absorber boring bar was conducted.The performance of the vibration damping boring bar was tested under different cutting parameters.The performance of the assembled variable damping damping boring bar was tested to verify the performance of state sensing and vibration control of the bar under different cutting parameters,one set of comparative experimental results shows that the maximum vibration acceleration of the boring bar is reduced by about 34.7% after vibration control.The research in this paper has some guiding significance in the vibration reduction of the boring bar and provides new ideas for the design of the boring bar.