Research On Transducer Driving Characteristics Of A Percussive Ultrasonic Driller

Drilling devices play an important role in space exploration missions.The driller drills a certain depth on the surface of the celestial body to take a sample and brings it back to Earth,which is conducive to the analysis of the composition of the soil on the surface of the celestial body and can help humans discover the mysteries of space.Compared with ordinary motor-driven drills,percussive ultrasonic drills have the characteristics of low power,small mass,small volume,and low drilling pressure.The piezoelectric transducer is the core device of the ultrasonic driller.The output characteristics of the piezoelectric transducer affect the drilling effect of the ultrasonic drill directly.The horn is an important part of the piezoelectric transducer.By changing the size parameters of the horn,the resonant frequency of the transducer and the amplitude of the output can be altered;adding a preload is an important part of the process of developing an ultrasonic transducer because it affects the performance of the transducer changing the size of the preload;the temperature has a certain influence on the output of the piezoelectric transducer.In this paper,the simulation and experimental research on size parameters,pre-tightening force and heat transfer of the horn configuration are carried out for the sandwich piezoelectric transducer.The effect of five groups of horn configuration parameters on the resonant frequency of the transducer and the amplitude of the output are studied,and by using the ANSYS finite element method,the modal analysis and harmonic response analysis of the transducer are carried out to obtain the resonant frequency of the device and the output amplitude of the transduction in different sizes,furthermore,evaluating the optimal size parameter values within a given range.Based on the COMSOL physics simulation software,this paper studies the influence of the preload on the output characteristics of the transducer and obtains the variation law of the output of the transducer with preload.For different diameters of transducers,an automatic pre-tightening platform for ultrasonic transducers has been designed to load the pre-tightening force accurately and slowly,and then doing some tests on the automatic pre-tightening platform.Studying the temperature change when the transducer is driven counts a lot in improving the performance of ultrasonic drilling.Therefore,the writer studies the temperature change of the transducer basing on the preload,then the surface temperature distribution of the transducer under steady state is obtained through simulation.The real temperature change curve of the transducer is obtained through experiments,so that the simulation temperature distribution results are verified.The differences between the experimental and simulation results are analyzed,and the causes of experimental diversity are proposed.