PROBLEM TO BE SOLVED: To provide an ultrasonic vibrator and manufacturing method therefor capable of adjusting a resonance frequency and preventing the output leakage of an ultrasonic vibration.SOLUTION: At least a part of a vibration part 2 where an acoustic lens 4 and a piezoelectric element 3 are integrally formed is arranged inside a peripheral wall part 51 in a cylindrical shape housing 5. An outer diameter D2 of the acoustic lens 4 is a little smaller than an inner diameter D3 of the peripheral wall part 51. An enlarged-diameter part 55 obtained by extending an inner peripheral surface 51C outward in a radial direction is formed at an end part 51B of the peripheral wall part 51. An adhesive 6 is arranged within the enlarged-diameter part 55. A hardened adhesive 6 elastically holds the vibration part 2 inside the housing 5 while keeping the vibration part 2 and the housing 5 in a non-contact state. The acoustic impedance of the adhesive 6 is lower than those of the acoustic lens 4 and the housing 5. The ultrasonic vibration of the piezoelectric element 3 is not easily propagated to the housing 5 via the adhesive 6. In an ultrasonic vibrator 1, the amount of the adhesive 6 can be adjusted to adjust the resonance frequency of the acoustic lens 4.COPYRIGHT: (C)2016,JPO&INPIT【課題】共振周波数を調整でき、且つ超音波振動の出力漏れを防止することができる超音波振動子およびその製造方法を提供する。【解決手段】円筒形状の筐体5は、周壁部51内に音響レンズ4と圧電素子3を一体に形成した振動部2の少なくとも一部を配置する。音響レンズ4の外径D2は周壁部51の内径D3よりわずかに小さい。周壁部51の端部51Bには内周面51Cを径方向外向きに広げた拡径部55が形成されている。接着剤6は拡径部55内に設けられる。硬化後の接着剤6は、振動部2と筐体5を非接触の状態に維持しながら、振動部2を筐体5内で弾性的に保持する。接着剤6の音響インピーダンスは、音響レンズ4および筐体5よりも低い。圧電素子3の超音波振動は、接着剤6を介して筐体5に伝播しにくい。また、超音波振動子1は、接着剤6の量を調整して音響レンズ4の共振周波数を調整できる。【選択図】図3
