| 摘要 |
PURPOSE:To output powerful ultrasonic oscillation by using a piezoelectric thickness oscillator to excite the center part of a disc-shaped oscillator and two fulcrums of a ring part forming a circle with this center part as the center and generating resonant oscillation of the mode where the disc-shaped oscillator is bent partially circularly. CONSTITUTION:A thick screw part 2 is formed in the center part on the lower face of a bending diaphragm 1 consisting of an Al disc, and a tapped hole is provided in the center part of this part 2. An exciting ring 4 on which the diaphragm 1 is put and which drives bending oscillation consists of a doughnut ring 4a and a mountain-shaped ring 4b which is provided on this ring 4a and has a circular-crowned top. Positive polarization surfaces of doughnut-shape thickness oscillators 5 and 6 consisting of Pb(ZrTi)O3 piezoelectric ceramics are allowed to face each other, and a terminal board 9 with a lead wire 12 is interposed between them, and a terminal board 10 with a lead wire 11 is brought into contact with the lower face of the oscillator 6, thus constituting a piezoelectric oscillating part. This oscillating part 4 is brought into contact with the lower face of the ring 4, and the diaphragm 1, the ring 4, and the piezoelectric oscillating part are fastened firmly by a cap bolt 8 inserted to a washer 7. |
