Design And Experimental Study Of Half-wave Resonant Ultrasonic Oscillator For Rotary Ultrasonic Machining

Rotary ultrasonic machining technology has been widely used in the processing of hard and brittle materials by virtue of its technological characteristics such as improving cutting force,reducing machining damage,prolonging tool life and improving machining efficiency.The rotating ultrasonic machining system is usually composed of a machining center,an ultrasonic power supply,an energy transmission device,and an ultrasonic vibrator.Ultrasonic vibrator as the core component of rotary ultrasonic machining system determines the resonant frequency,vibration amplitude and working stability of rotary ultrasonic machining system.However,there is presently still little research work on design,simulation analysis,and performance testing of half-wave resonance ultrasonic vibrators.Therefore,under the funding of the Key Research and Development Program of Zhejiang Province(Grant No.2019C01118),this article carried out the structural design,finite element simulation analysis,and vibration performance of the half-wave resonance ultrasonic vibrator.And completed the comparative experimental study of the rotary ultrasonic machining based on the half-wave resonance ultrasonic vibrator and the non-ultrasonic machining.The main research contents of this paper are as follows:Chapter 1: The background and significance of this research is introduced.Then introduce the working principle and characteristics of rotary ultrasonic machining technology,summarize the domestic and foreign research status of rotary ultrasonic machining method and ultrasonic vibrator structure design in detail,and summarize the current research institute Existing problems,and on this basis,put forward the main research content and structural framework of this article.Chapter 2: Analyze the requirements of the BT30 machining center for rotating ultrasonic machining,and put forward the structural design plan of the half-wave resonant ultrasonic vibrator.The structural analysis of the ultrasonic transducer,ultrasonic horn and ultrasonic cutter in the ultrasonic vibrator are carried out in turn.Material selection and electromechanical equivalent method were used to calculate the structural parameters of the ultrasonic vibrator,and finally a simplified two-dimensional model of the half-wave resonant ultrasonic vibrator was obtained.Chapter 3: Based on the assembly requirements of the ultrasonic vibrator,a threedimensional finite element model of the ultrasonic vibrator is constructed on the basis of the twodimensional simplified model;the modal analysis method and the harmonic response analysis method are used to determine the ultrasonic vibrator under the half-wave resonance state.Characteristic frequency and vibration displacement distribution;on this basis,the flange installation position of the ultrasonic vibrator is determined,and the structural design scheme of the Z-shaped flange is proposed,and the simulation analysis is compared with the traditional discshaped flange structure.Chapter 4: Completed the manufacturing and assembly of the ultrasonic vibrator,using an impedance analyzer to test and analyze the impedance characteristics of the ultrasonic vibrator in the free state,verified the rationality of the structural design of the ultrasonic vibrator and the correctness of the simulation analysis;built the ultrasonic vibration The test platform uses an ultrasonic digital power source to excite the ultrasonic vibrator under the constraint of the flange.The effects of voltage,tool diameter,tool elongation,and tool load on the vibration frequency of the ultrasonic vibrator and the amplitude of the tool end face are studied.Chapter 5: The experimental system of rotary ultrasonic machining based on half-wave resonant ultrasonic vibrator was built,the comparative experimental study of rotary ultrasonic machining and non-ultrasonic machining for zirconia ceramics was carried out,and the ultrasonic vibration in improving the surface roughness of the workpiece was analyzed.The mechanism of action has verified the effectiveness of the ultrasonic vibrator in the process of rotary ultrasonic machining;on this basis,research the improvement of the surface roughness of the workpiece by ultrasonic vibration under different process parameters(spindle speed,feed speed,grinding depth).Chapter 6: Summarizes the main research work of the thesis and looks forward to the future research work.