Development of Solid Horn with Diaphragm for High Power Ultrasound Radiation. 1st Report. Natural Frequency and Vibration Mode.

Abstract

Solid horns are used to magnify the displacement amplitude for power ultrasonics. They have half a wavelength and are connected vertically with the transducer. Therefore the ultrasonic vibration system usually becomes too long and heavy to handle. Thus a new type of solid horn with a metallic diaphragm has been developed by the authors. The horn transduces the little longitudinal vibration to the extremely large flexural one. Therefore it is possible to shorten and to make lighter the ultrasonic vibration system by replacing connected horns to a simple new horn. It is thought that the horn is suitable as a high power ultrasound source, further the high efficiency of the sound radiation is obtained by the larger area and in-phase vibration of sound radiation face. Thus the authors have attempted to expand the diameter of the diaphragm by keeping in-phase vibration. In this paper, the free vibration of the solid horn with a diaphragm and the one with double concentric diaphragms are analyzed using FEM and theory. The analytical results on the natural frequency and the vibration mode are confirmed experimentally.