| 摘要 |
Device in ultrasonic knives of the kind including a transducer for converting electrical energy at ultrasonic frequency to a mechanical oscillation. An amplitude transformer (2) forms the tip of the knife. The length of the ultrasonic transformer is in the order of magnitude 0.72 times the wavelength of the ultrasonic frequency. The ultrasonic transformer is an integral unit comprising a cylindrical portion (40), an integral portion (41) which is the curve of a wave function of the fourth order Fourier form, and a tip portion (42) which is conical, whereby the maximum stroke of the longitudinal oscillation mode of the knife is a desired resonance frequency, this resonance frequency being greatly separated, in the order of magnitude 20% with relation to the resonance frequency, from resonance frequency pertaining to harmonics of the desired resonance frequency in the longitudinal oscillation mode, and resonance frequency pertaining to oscillations in the transverse mode. |
