纵-扭复合模式夹心式功率超声压电换能器的研究

本文对纵-扭复合模式功率超声换能器进行了研究,该换能器由指数型前后金属喇叭盖板以及轴向极化和切向极化的两组压电陶瓷晶片组成。文中推出了换能器中纵向及扭转两种振动模式的共振频率方程。通过改变换能器前后指数型盖板的半径减编系数,得出了换能器中纵向与扭转两种振动模式同频共振的条件。实验表明,换能器的设计频率与测试频率基本一致,而且,换能器的纵向及扭转共振频率也比较接近,该换能器可望应用于超声加工及焊接等高振幅的功率超声技术中。

Study on the sandwiched longitudinal-torsional ultrasonic transducer

The longitudinal-torsional composite mode ultrasonic transducer is studied. The transducer consists of the front and back exponential metal horns, and the axially and tangentially polarized piezoelectric ceramic piles. The resonance frequency equations for the longitudinal and torsional vibrations in the transducer are derived. By changing the cross sectional radius decay coefficient of the exponential metal horns, the longitudinal and torsional vibrations in the transducer could resonate at the same resonance frequency. Experimental results show that the measured resonance frequency is in good agreement with the theoretical results, and the resonance frequency for the longitudinal vibration is basically the same as that for the torsional vibration in the transducer. This kind of transducer could be used in ultrasonic processing and other high power ultrasonic technologies.