| 摘要 |
PURPOSE:To make a vibrator lighter by obtaining the relation between the capacity ratio which relates with an electromechanical conversion efficiency and the vibrator shape, and by setting a piezo-ceramic part sectional area / a rear mass part sectional area >0.15 concerning the latter half from an oscillation node to a rear mass end part. CONSTITUTION:A 1/2 wavelength-resonance bolted Langevin vibtator is composed of a front mass part 11, a peizo-ceramic part 12, and a rear mass part. At this time, a rather small sectional area S3 of a bolt part 14 is set for a sectional area S2 of the ceramic part 12. Concerning the first half part from the sound radiating end of the front mass part 11 to the oscillation node, the following expression is set: 0.03<=the sectional area S2 of the ceramic part 12/a sectional area S1 of the front mass part 11<=0.25, 0.1<a length l1 of the front mass part 11)/a length l0 from the sound radiating end of the front mass part 11 to the oscillation node<0.35. Conderning the latter half from the oscillation node to the rear mass end part, the sectional area S2/sectional area S4 of the rear mass part>0.15 is set. |
