JPS6349192B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to acoustic transponders.

Acoustic transponders used as acoustic navigation reference points in the ocean or for installing and retrieving marine equipment must reliably receive acoustic interrogation signals from interrogators and reliably send acoustic response signals to the interrogators. It is necessary to be able to transmit waves.

FIG. 1 is a perspective view showing a typical appearance of such an acoustic transponder, in which 1 is a transducer unit, 2 is an electronic device unit, and 3 is a disconnection mechanism unit.

Figure 2 is a partially cutaway perspective view showing the structure of a transducer unit in a conventional acoustic transponder.
It consists of a boot 4, a cylindrical piezoelectric vibrator 5 provided in the boot 4, and oil 6 filling the boot 4, and the boot 4 is a watertight housing 7 of an electronic equipment unit.
It is attached to a lid 8 fixed to the top. 9
is a protective fitting.

However, according to such an acoustic transponder, since the piezoelectric vibrator 5 is cylindrical, the vibration mode of the piezoelectric vibrator 5 when transmitting and receiving signals with the interrogator is the cylindrical breathing mode, and therefore the horizontal The transmission and reception of signals in the vertical direction is the most efficient, and the transmission and reception of signals in the vertical direction, that is, the transmission and reception of signals between the interrogator installed on the measurement vessel on the sea surface directly above the acoustic transponder and the acoustic transponder standing upright on the seabed, is less efficient. The drawback was that it was not.

Furthermore, since the diameter of the watertight casing 7 of the electronic equipment unit is extremely large compared to the diameter of the piezoelectric vibrator 5, it may be affected by acoustic reflected diffraction waves from this watertight casing 7, and may even be affected by the ocean floor. Therefore, depending on the angle between the interrogator and the acoustic transponder, signal transmission and reception may become extremely inefficient.

The present invention solves these drawbacks and is characterized by providing a cone-shaped reflector on the inside or outside of the boot.The purpose of the present invention is to use the reflector to transmit and receive signals from the vertical direction in the most efficient manner. The aim is to make it possible to do so.

To explain the following with reference to the drawings, FIG. 3 is a partially cutaway perspective view showing one embodiment of the present invention. FIG. 5 is a side sectional view of the main part of FIG. The cylindrical piezoelectric vibrator 12 is oil that fills the inside of the boot 10.
is attached to a lid 8 fixed to the top of the watertight casing 7 of the electronic equipment unit.

Reference numeral 13 denotes a cone-shaped reflector, and this reflector 13 is formed by pasting a good acoustic reflective material such as Kirk rubber onto a metal cone.
It is installed outside the piezoelectric vibrator 11 in the inside of the piezoelectric vibrator 11 .

14 is a protective metal fitting for protecting the transducer unit made up of these parts.

FIG. 6 is an explanatory diagram showing the state of use of the acoustic transponder having the above configuration, where 20 is the acoustic transponder, and 21 is an interrogator equipped on the measurement ship.

Next, a case will be described in which a response signal is transmitted from the acoustic transponder 20 side in the above-described configuration.

When a signal voltage from the electronic equipment unit is applied to the piezoelectric vibrator 11, the piezoelectric vibrator 11 causes breathing vibration and transmits a sound wave in the radial direction, that is, in the horizontal direction. The transmitted sound waves are reflected and refracted by the reflector 13, but if the aperture angle of the reflector 13 is 90 degrees as shown in FIG. Sound waves are most strongly radiated in the vertical direction.
Therefore, transmission and reception in the vertical direction, that is, transmission and reception of signals between the interrogator 21 installed on the measurement ship directly above the acoustic transponder 20 and the acoustic transponder standing upright on the seabed can be performed most efficiently.

Furthermore, since the acoustic reflected diffraction waves from the watertight housing 7 of the electronic equipment unit and the reflected waves from the seabed are blocked by the reflector 13, the interrogator 21 and the acoustic transponder 20 are connected to each other as shown in FIG.
Signal transmission and reception does not become extremely inefficient in range A, which is the practical angular range of ±45°.

As explained above, in this embodiment, since the cone-shaped reflector 13 is provided inside the boot 10, the structure has acoustic directivity that makes the transmission and reception of signals in the vertical direction most efficient. Since it is no longer affected by the diffracted waves reflected by the watertight casing 7 of the unit and the waves reflected from the seabed, it has the effect that acoustic signals can be reliably transmitted and received with the interrogator 21 installed on the measurement vessel. .

Next, another embodiment will be explained with reference to FIG. Fourth
In the figure, 15 is a boot, and 16 is the boot 15.
The cylindrical piezoelectric vibrator 17 provided inside is oil that fills the inside of the boot 15, and the boot 15 is a lid 8 fixed to the upper part of the watertight casing 7 of the electronic equipment unit as in the case of FIG. installed on.

A cone-shaped reflector 18 is installed on the outside of the boot 15. 19 is a protective metal fitting.

In this embodiment, the reflector 18 is installed outside the boot 15 as described above, but the same effect as the embodiment shown in FIG. 3 can be obtained even in this case.

As explained above, the present invention provides a cone-shaped reflector in the transducer unit, so it is possible to realize a transponder with acoustic directivity that makes signal transmission and reception most efficient in the vertical direction. It is highly effective when used as an acoustic navigation reference point in the sea, or when used for installing and recovering marine equipment.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the external appearance of an acoustic transponder, Fig. 2 is a partially cutaway perspective view showing a conventional example, and Fig. 3 is a perspective view showing the external appearance of an acoustic transponder.
The figure is a partially cutaway perspective view showing one embodiment of the present invention, FIG. 4 is a partially cutaway perspective view showing another embodiment, FIG. 5 is a side sectional view of the main part of FIG. 3, and FIG. FIG. 4 is an explanatory diagram showing how the acoustic transponder of FIG. 3 is used; DESCRIPTION OF SYMBOLS 1... Transducer/receiver unit, 2... Electronic device unit, 3... Separation mechanism unit, 7... Watertight casing, 8...
Lid body, 10, 15... Boot, 11, 16... Piezoelectric vibrator, 12, 17... Oil, 13, 18... Reflector.

Claims (1)

[Scope of Claims] 1. A transducer unit consisting of a boot and a piezoelectric vibrator etc. provided in the boot is provided at one end of a watertight casing of the electronic equipment unit, and the transducer unit is placed upward. An acoustic transponder installed on the seabed, characterized in that a cone-shaped reflector having a diameter smaller than the diameter of the watertight casing is installed inside or outside the boot with its opening facing upward.