Study On The Rotary Ultrasonic Grinding Device And Process Of Small Hole In Engineering Ceramics

Engineering ceramic materials have excellent physical properties,good wear resistance,low friction coefficient,and high hardness and brittleness.Due to high hardness,low line speed,small machining gaps,difficulty in excretion and heat dissipation,poor rigidity of the tool head,and engineering ceramic hole grinding has become a major technical problem.Rotary ultrasonic grinding is a combination of traditional grinding and ultrasonic machining technologies.It is one of the accepted and inexpensive methods for grinding ceramic holes in the academic community.Domestic and foreign researchers have done a lot of research and developed rotary ultrasonic grinding equipment.However,foreign products are too expensive and many small and medium-sized enterprises are discouraged.In order to promote the development of social productivity,this article has developed a rotary ultrasonic spindle,and made a process experimental study,the main content is as follows:Based on the theory of ultrasonic vibration,the frequency equations of the transducer and the four-section composite horn were derived using the analytical method and the matrix transmission method.Using the frequency equation,the structural dimensions of the transducer were designed.Through reasonable simplification of the structure and material,the approximate range of the size of the horn(tool head)was calculated.The structural static analysis,modal analysis and harmonic response analysis of different lengths of horns(tool heads)were performed using ANSYS.The effect of tool head length on vibration performance was studied.Simulation results show that the longer the tool head,the smaller the frequency and the greater the amplitude.The influence of the length of the tool head on the frequency was experimentally studied.The result was consistent with the simulation and the size of the tool head was determined accordingly.Through experiments,the influence of the preload on the vibration performance of the nut on the tool head was also studied.Experimental results show that the greater the preload,the greater the resonant frequency and the smaller the dynamic resistance.The vibrator was measured with a frequency of 40027 Hz,a quality factor of 635.7,a dynamic resistance of 132 ?,and an amplitude of 32 ?m.With the oscillator as the starting point,a rotating ultrasonic spindle with a rated speed of 10000 rpm was designed.A tapered flange was designed to ensure the vibration performance and installation accuracy of the vibrator.Non-contact induction power supply devices have been designed.The pendulum surface of the rotary ultrasonic spindle was measured with a dial gauge,and the radial runout was 4 ?m.In the rotary ultrasonic grinding and traditional grinding two processing methods,the spindle speed,axial feed speed,radial feed rate were studied.Research shows that rotary ultrasonic grinding is 7.8%-27.5% lower than that of traditional grinding.At the same time,the influence of the ultrasonic power supply voltage on the surface roughness was also studied under the two processing methods.The research shows that rotary ultrasonic grinding is 13.7%~27.4% lower than that of traditional grinding.Between 30V~80V,the greater the voltage,the smaller the surface roughness.