JPS596557B2 - ultrasonic horn - Google Patents

Description

[Detailed Description of the Invention] In a conventional ultrasonic horn, as shown in Fig. 1A, an ultrasonic vibrator d is attached to the throat a of a horn C whose diameter gradually increases from the throat a to the opening. The result of actually measuring the sound pressure in the direction that makes an angle of α degree at the throat a of the horn C with respect to the central axis c1 of the horn C is as shown in Figure 1, and the α degree increases. As the sound pressure increases and decreases over time, it has the disadvantage of poor directional characteristics.

The present invention eliminates the above-mentioned drawbacks of the conventional technology, and the embodiments of the present invention will be described below with reference to the drawings.
4 is a horn whose diameter gradually increases as it goes from the throat 2 to the opening 3; 4 is a cylindrical body whose tip is integrally connected to the throat 2 of the horn 1; an enlarged caliber is formed on the inner circumferential body in the middle of the horn; 5 is formed.

Reference numeral 6 denotes an ultrasonic vibrator, which is made by, for example, attaching a pair of electrodes to a piece of piezoelectric crystal, and when a high frequency voltage is applied between the pair of electrodes, the piece of piezoelectric crystal vibrates and generates ultrasonic waves. It is attached to the base end of the cylindrical body 4.

The present invention has the above-described configuration, and the result of actually measuring the sound pressure H in a direction forming an angle of β degree at the throat portion 2 of the horn 1 with respect to the central axis 1a of the horn 1 is as shown in FIG. , when the angle β is a predetermined value or more, the sound pressure does not increase or decrease significantly as the sound pressure decreases, and the directivity characteristics improve.

Note that the length el from the tip of the cylindrical body 4 to the enlarged aperture portion 5 is approximately 13 times the wavelength of the ultrasonic wave, and the length e of the enlarged aperture portion 5 is
2 and the length e3 from the enlarged aperture portion 5 to the ultrasonic transducer 6 are optimally set to be approximately equal to the wavelength of the ultrasonic wave.

As described above, the present invention connects the tip of the cylindrical body 4 integrally to the throat part 2 of the horn 1 whose diameter gradually increases from the throat part 2 toward the opening 3, and connects the tip of the cylindrical body 4 to the middle part of the cylindrical body 4. Since the enlarged aperture portion 5 is formed and the ultrasonic transducer 6 is attached to the base end of the cylindrical body 4, as can be seen from the actual measurement results, the directivity characteristics are improved.

[Brief explanation of the drawing]

Fig. 1A is a sectional view of a conventional ultrasonic horn, Fig. 1A is a directional characteristic diagram of a conventional ultrasonic horn, Fig. 2 is a sectional view of an embodiment of the present invention, and Fig. 3 is a sectional view of the ultrasonic horn of the present invention. It is a directional characteristic diagram of a horn. 1 is a horn, 2 is a throat, 3 is an opening, 4 is a cylindrical body, 5
is an enlarged aperture portion, and 6 is an ultrasonic transducer.

Claims (1)

[Claims] 1. The tip of a cylindrical body 4 is integrally connected to the throat 2 of the horn 1 whose diameter gradually increases from the throat 2 toward the opening 3, and an enlarged caliber 5 is formed in the middle of the cylindrical body 4. The ultrasonic horn includes an ultrasonic vibrator 6 attached to the base end of a cylindrical body 4.