SPHERICAL ULTRASONIC WAVE TRANSDUCER AND UNDERWATER MEASUREMENT DEVICE

摘要

The purpose of the present invention is to provide a spherical ultrasonic wave transducer that can be formed at low cost and with ease. An energy converting part 10 of a spherical ultrasonic wave transducer 6 includes a plurality of piezoelectric elements 14 and a spherical base 15. Each piezoelectric element 14 is mainly composed of a piezoelectric ceramic element piece 16 that has a tapered end portion 18 the width of which becomes smaller toward at least one side in the longitudinal direction, that has a convexly curved outer surface 21 and a concavely curved inner surface 22, and that is arc-shaped on the whole when seen from the side; and electrodes 26 and 27 are respectively provided on the outer surface 21 and the inner surface 22. The spherical base 15 is arranged such that the tapered end portions 18 of the piezoelectric elements 14 face one location on the spherical base 15 and support each piezoelectric element 14 from the inner surface 22 side thereof so as to form a spherical shell shape on the whole. Each piezoelectric element 14 vibrates in a vibration mode of a length direction natural frequency which corresponds to the length of the piezoelectric element, so as to expand and contract in the length direction.