Research The Acoustic Characteristics Of The Untraditional Ultrasonic Machining Equipment

With the rapid development of high-end equipment technology in the aircraft,new energy technologies etc. the requirements for the overall manufacturing technology of the large size, special-shaped, deep cavity of composite material components are more and more stringent, and ultrasonic assisted processing is a new kind of mechanical processing method, it has a unique advantage in the fragile materials field, therefore, The develop of ultrasonic assisted system used to the overall manufacturing of the large size, special-shaped, deep cavity, the surface components has attracted much attention. At present, development of the system with large length to diameter ratio of the horn and cup horn has not been well solved, this paper for this system the following research:1) Ultrasonic transducer is designed by acoustical methods and optimization. And based on the finite element analysis, transducer are analyzed by the modal and harmonic response, it is respectively obtained the resonance frequency, vibration mode and the amplitude-frequency curves of the output of its before and after. Impedance of transducer and amplitude are measured by the experiment, the transducer can stably output a vibration frequency of 25.2 kHz and an amplitude of 4.2μm. The structure and principle of contactless power transmission device are expounded, and original, vice side matched form of the circuit is analyzed. By the finite element analysis, the result shows that the transmission efficiency of the contactless power transmission device is low along with the magnetic core clearance.2) Three horns with large length to diameter ratio of the conical composite, composite index and catenary composite are designed based on transmission matrix theory. And the finite element models are established to analyze the modal and stiffness. Three horns are manufactured and are the vibration performance test and working stability experiment, designed frequency and simulation and experiment results are basically identical, and catenary composite horns is the best performance.3) An ultrasonic cup tool horn is designed based on the bending vibration theory, the coupling vibration theory and the horn design theory and combined with finite element analysis. Its structural stiffness and coupling dynamics is researched, the research shows that stiffness of the cup horn is better, and when frequency of the horn and frequency of the cup head is same or similar, coupling effect is best, and the largest output amplitude. High, bottom thickness, inner diameter and cylindrical chamfering of the cup head are researched the influence to the resonance frequency of the horn by finite simulation and experimental test, research shows that the natural frequencies of the cup horn will decrease with the bottom thickness of the cup head decrease when other conditions remain unchanged; but increase along with the wall and the inner diameter decrease; a little change with the cylindrical chamfering increase, and the measured results and simulation analysis are basically identical. The impedance characteristics and the amplitude characteristics of the developed cup horn are researched by practical test, experiment shows that acoustics-electric conversion efficiency of the vibration system is high, and performance is stable, the head output surface amplitude of cup horn is a little change, was 8.0μm and axial angle of 70.2 degrees, and along the axial direction closer to output, the greater output amplitude, the two experimental results are consistent with the simulation results.