一种新型级联式高强度功率超声压电陶瓷换能器

A new type of cascaded high intensity piezoelectric ultrasonic transducers

基于传统夹心式压电陶瓷换能器,提出了一种新型级联式高强度功率超声换能器。该换能器由多个半波长夹心式压电陶瓷换能器通过电端并联及机械端串联而成。基于一维理论,得出了换能器的六端机电等效电路,分析了换能器的电阻抗频率特性,并给出换能器的共振频率方程。研究了不同振动模态下,换能器的共振频率、反共振频率以及有效机电耦合系数与压电陶瓷晶堆间距的依赖关系。实验制造2个级联式功率超声换能器,并对其共振频率和有效机电耦合系数进行了测试,实验结果与理论分析相吻合。此类级联式高强度功率超声换能器可望在超声波液体处理、超声波加工等大功率超声技术中获得应用。

A new type of high intensity piezoelectric ultrasonic transducer is presented.The transducer is composed of two traditional longitudinally sandwiched piezoelectric transducers,which are connected together in series mechanically and in parallel electrically.Based on the analytical method,the electromechanical equivalent circuit is derived and the resonance/anti-resonance frequency equations are obtained.The impedance characteristics and the vibrational modes of the transducer are analyzed.The dependency of the resonance/anti-resonance frequency and the effective electromechanical coupling coefficient on the distance between two piezoelectric stacks are studied.Two prototypes of the transducers are designed and made,and the resonance/anti-resonance frequency is measured.It is shown that the analytical resonance/anti-resonance frequencies are in good agreement with the experimental results.It is expected that this kind of transducer can be used in large power and high intensity ultrasonic applications,such as ultrasonic liquid processing,ultrasonic metal machining and ultrasonic welding and soldering.