Design Of A Robot Longitudinal-torsional Resonance Rotary Ultrasonic Machining System

The aerospace field,as a national strategic support,has always been the focus of vigorous national development.In recent years,aviation aircraft design and manufacturing technologies have continued to advance.Therefore,the higher requirements are imposed for processing.Traditional CNC machine tools cannot complete flexible processing of large workpieces and complex curved surfaces due to their structural limitations.The application of industrial robots will definitely provide a huge driving force for the change of the aerospace manufacturing industry.The chattering problem in the ordinary machining of robots has seriously affected the widespread application of robotic machining.In view of this situation,this paper studies the design of a robotic longitudinal torsional resonance rotary ultrasonic machining system.It has been found that the machining efficiency is greatly improved compared to a single longitudinal vibration.The main research contents are as follows:(1)A mathematical model of a non-contact power transmission system is established.Based on the mutual inductance model,the calculation method of the relevant parameters of the electromagnetic coupler and the relationship between the parameters are obtained.The influence mechanism of each parameter on the transmission characteristics of the electromagnetic coupler is analyzed.It lays the foundation for further structural design of the coupler.The circuit topology of the primary and secondary circuits is improved.The influence of the compensation network on the primary and secondary circuits in the primary and secondary circuits is studied.The power transmission capacity and efficiency of the system are improved.The core material,core structure and coil of the non-contact power transmission system of the robot are designed.Finally,the influence of the gap between the two coils and the air gap between the cores on the coupling coefficient were analyzed using Maxwell.(2)Based on the analysis of the effects of piezoelectric material characteristics and horn performance parameters on robotic ultrasonic machining tool holders,the main performance parameters of ultrasonic machining transducers were calculated.According to the form of longitudinal torsional resonance rotating ultrasonic vibration,the stress ratio of longitudinal torsional horn is analyzed.The influence rule of the helical groove parameters of the tool holder on the longitudinal torsional resonance frequency and amplitude was clarified.Optimal design parameters are obtained.Finally,the longitudinal torsional resonance frequency and amplitude were detected.The longitudinal and torsional vibration amplitudes were 9.3um and 4.5um,respectively.The accuracy and validity of the simulation calculation are verified.(3)Robot longitudinal torsional rotary ultrasonic milling and drilling experiments of the robot were carried out.The changing trend of milling force under ultrasonic vibration and its influence on machining quality were clarified.The influence of Robot longitudinal torsional rotary ultrasonic vibration on milling tool marks was analyzed.Robot longitudinal torsional rotary ultrasonic milling drilling experiment of a robot was carried out to analyze the influence of ultrasonic amplitude on drilling force and hole wall damage.The experimental results show that the longitudinal torsional resonance can reduce the robot's milling force by about 46.7% on average.The planarity of the milled surface is reduced by about 50.4%.The hole deviation is reduced by about 38.2%.The hole wall roughness is reduced by about 36.1%.