| 摘要 |
A front mass of a vibration-generating unit comprises a supported flange part, and a block part provided proximal to the flange part. A proximal end of the block part abuts a leading end of an element unit. When ultrasonic vibrations generated at piezoelectric elements of the element unit are transmitted to the front mass, the front mass vibrates in a predetermined frequency region in which a reference vibration antinode is located at a boundary location between the block part and the element unit or near the boundary location, the reference vibration antinode being one of the vibration antinodes that are located proximal to the flange part. |
