Research On Principle And Characteristics Of Variable Damping Vibration Absorption Boring Bar

In deep hole boring,the stiffness of boring rod body is reduced because of the great elongation of hanging,and the vibration of the bar body is easy to occur during the machining.The vibration of the rod body will reduce the machining quality of the inner hole surface and even lead to defects and shorten the service life of the tool,etc.The precision deep-hole machining parts are mostly the key parts in the fields of aerospace,military industry,national defense and so on.At present,most of the tools used to process the precision deep-hole parts in China rely on imports.At the same time,the foreign standardized serialized products have invaded our manufacturing industry and formed a monopoly in the high-end manufacturing field.This situation has posed a great threat to our national defense security and seriously restricted the development of our manufacturing industry.Boring is the main way of deep hole machining,so the study of vibration absorption technology of boring bar is of great significance.The basic parameters of boring process are analyzed,and the relationship between cutting area & line length and basic parameters of machining process is obtained.The mechanical model about cutting area and line length is established.The simulation software is designed by MATLAB and the machined surface morphology considering vibration is predicted.The principle of vibration and dynamic vibration absorption in boring process is analyzed,and the dynamic equation of vibration absorption boring bar is established.The relationship between damping and amplitude ratio is obtained by solving the dynamic equation.The control strategy of variable damping boring bar is put forward,and the vibration absorption boring bar is designed according to variable damping principle.The electromagnetic damping vibration absorber is designed according to the principle of variable damping,and the static characteristics of boring bar are simulated and analyzed.The basic parameters of the electromagnetic damper are designed and the relationship curve between the damping coefficient and the current is obtained through the theoretical derivation of the damping coefficient.The average amplitude of the signal is solved by smoothing the vibration acceleration data based on MATLAB.The method of extracting the characteristic of vibration signal is found,and the velocity and displacement of vibration are obtained by Fourier transform and integral processing.The damping of the electromagnetic damping absorber is adjusted by real-time on-line control to change the vibration absorption performance of the boring bar and realize the on-line control of the vibration.The parameters of the dynamic foundation of the variable damping vibration absorption boring bar are tested,verifing the accuracy of theoretical derivation.The static and dynamic performance of the variable damping vibration absorption boring bar is tested to test its vibration absorption performance.Boring experiment was carried out to analyze the influence of cutting parameters on vibration.Finally,the boring experiment of the variable damping vibration absorption boring bar is carried out to verify its vibration absorption performance.Provide technical support for deep hole processing technology.