close

Вход

Забыли?

вход по аккаунту

?

JPH099385

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JPH099385
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an
underwater wave receiver, and more particularly to an underwater wave receiver used for
acoustic measurement in the ocean and adapted to reduce noise generated by fluid flow such as
tidal current. .
[0002]
2. Description of the Related Art FIG. 2 is a schematic cross-sectional view of a conventional
suspension underwater receiver. The figure shows a cross section of the rotationally symmetric
form (rotary body). The underwater receiver for suspension is used in a state where the
electroacoustic transducer is suspended from a predetermined position, for example, at sea level
or in the sea. In FIG. 2, reference numeral 11 denotes an electroacoustic transducer formed of a
piezoelectric ceramic (piezoelectric ceramic) such as PZT (lead titanate) or the like as an acoustic
sensor material. A signal cable 12 doubles as a suspension cable, and a signal line in the cable is
connected to an electrode (not shown) of the electroacoustic transducer 11. Reference numeral
13 denotes a case for clamping the tip of the signal cable 12 and holding the electroacoustic
transducer 11. Reference numeral 14 denotes a waterproof rubber molded to maintain the
electrical insulation of the electroacoustic transducer 11.
[0003]
In the underwater wave receiver having the above-mentioned configuration, the sound wave
04-05-2019
1
coming to the water wave receiver penetrates the waterproof rubber 14 and is converted into an
electric signal proportional to the strength of the sound wave by the electro-acoustic transducer
11 and a signal cable It is detected through 12 signal lines.
[0004]
However, in the conventional underwater wave receiver as described above, there is a flow of
fluid by, for example, a tidal current in the actual measurement environment, and the water wave
receiver can Since the wave pressure is applied to the electroacoustic transducer because it is
received on the front of the receiver, it is a noise.
The reason is that the area on which the sound wave is incident is large, that is, the area to be
subjected to the vibration of the fluid is large, so that it is inevitable that the noise becomes large.
[0005]
SUMMARY OF THE INVENTION An underwater receiver according to the present invention is an
underwater receiver which has an electroacoustic transducer as an acoustic sensor and is used
suspended in water, and is internally provided therein. An acoustic entrance is provided in a
hollow rigid shell in which the electroacoustic transducer is disposed, and the hollow portion
constituting the interior of the shell is filled with an elastic elastic material. Here, it is preferable
that the acoustic incident port provided in the shell is provided at a position facing the
electroacoustic transducer, and it is preferable that the above elastic material be a waterproof
rubber such as a rubber elastic body. is there.
[0006]
In the present invention, an acoustic entrance is provided in a hollow rigid shell in which the
electroacoustic transducer is disposed, and the hollow portion of the shell is filled with an
acoustically transparent elastic material to be received underwater. Since the wave is formed, the
flow of fluid acts as a receiver, and even if irregular pressure is always applied to the surface of
the receiver, the pressure acts on the surface of the hard case, so the electro-acoustic transducer
directly It is hardly affected by the pressure. Therefore, when the receiver is suspended in water,
04-05-2019
2
the incoming sound wave reaches the electroacoustic transducer through the acoustic entrance
and is normally detected, but when the receiver is suspended in water, The pressure due to flow
is no longer measured as receiver noise (background), and the S / N of the measurement is
improved.
[0007]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a schematic sectional view
showing an embodiment of a suspended underwater receiver according to the present invention.
The figure shows a cross section of the rotationally symmetric form (rotary body). In FIG. 1,
reference numeral 21 denotes an electro-acoustic transducer formed of a piezoelectric ceramic
(piezoelectric ceramic) such as PZT (lead titanate) or the like as an acoustic sensor material. A
signal cable 22 also serving as a suspension cable has a signal line inside, and the signal line is
connected to an electrode (not shown) of the electroacoustic transducer 21. A case 23 clamps the
tip of the signal cable 22 and holds the electro-acoustic transducer 21. The case 23 forms a rigid
shell having an acoustic entrance 25. Reference numeral 24 denotes waterproof rubber filled in
the case 23 in order to maintain the electrical insulation of the electroacoustic transducer 21.
[0008]
The underwater wave receiver according to the present invention has the electro-acoustic
transducer 21 arranged in a seemingly closed case 23 constituted by a hollow rigid shell, as seen
in the embodiment of FIG. It is a feature. The case 23 in the form of a closed body is provided
with an acoustic entrance 25 in the form of an opening at a position facing the installation place
of the electroacoustic transducer 21. In addition, the inside of the case 23 is filled with the
waterproof rubber 24 which is a rubber elastic body, and the hollow portion (the space inside) of
the case 23 is formed with a sufficiently small dimension with respect to the wavelength of the
sound wave.
[0009]
The case 23 has a function as a Helmholtz resonator well known in principle. However, the
resonance frequency of the Helmholtz resonator in this case is determined by the stiffness
(rigidity) of the waterproof rubber 24 which is an elastic body and the effective mass of the
acoustic entrance 25. The size of the acoustic entrance 25 is set so that the resonance frequency
04-05-2019
3
is higher than the frequency band to be used (detected) and has a minimum size.
[0010]
In the underwater wave receiver according to the present embodiment, the sound wave coming
to the water wave receiver is incident from the acoustic incident port 25 of the case 23, passes
through the waterproof rubber 24, and reaches the electroacoustic transducer 21, where It is
converted into an electrical signal proportional to the intensity of the sound wave. This electrical
signal is detected by an external circuit (not shown) via the signal line of the signal cable 22.
[0011]
Here, the action of noise reduction by the case 23 will be described. In the actual measurement
environment of the underwater receiver, there is always a fluid flow that is not necessarily
periodic due to the tidal current or the like, and such fluid collides with the receiver surface,
thereby generating a collision pressure. In the case of the present embodiment, since the case 23
receives the pressure, the pressure does not act directly on the electroacoustic transducer 21. In
this way, the sound pressure by the sound wave incident from the sound incident port 25 acts on
the electroacoustic transducer 21 through the waterproof rubber 24 and is converted into
electricity here and measured, but the pressure of the tidal current is On the other hand, the case
23 is cut (shielded) by the case 23, and the electroacoustic transducer 21 does not act on the
pressure by the tidal current. For this reason, since the noise N due to the tidal current is
significantly reduced, an S / N high sensitivity underwater receiver is formed.
[0012]
As described above, according to the present embodiment, the sound pressure incident from the
sound incident port acts on the electroacoustic transducer through the waterproof rubber, and is
electrically converted here and normally measured, but the pressure of the tidal current Has a
form that is cut in the case with respect to the inside, and the electroacoustic transducer has an
effect that pressure due to the current does not act. For this reason, the noise N due to the tidal
current is significantly reduced, and an excellent S / N high sensitivity underwater receiver is
configured.
04-05-2019
4
[0013]
As described above in detail, according to the present invention, the acoustic entrance is
provided in the hollow rigid shell in which the electroacoustic transducer is disposed, and the
hollow portion of the shell is made to transmit sound. Since the underwater receiver is
configured by being filled with a flexible elastic material, when the receiver is suspended in
water, the fluid flow hits the receiver and the pressure on the receiver surface is always irregular.
Even if applied, the pressure acts on the hard case surface, so the direct electroacoustic
transducer is hardly affected by the pressure. Therefore, the incoming sound wave reaches the
electroacoustic transducer through the acoustic entrance and is detected normally, but the
pressure due to the fluid flow is not measured as the noise of the receiver, so the noise is large.
This has the effect of being reduced and a significant improvement of the sensitivity of the
underwater receiver being achieved.
[0014]
Brief description of the drawings
[0015]
1 is a schematic cross-sectional view showing an embodiment of the underwater receiver for
suspension according to the present invention.
[0016]
2 is a schematic cross-sectional view showing a conventional suspension underwater receiver.
[0017]
Explanation of sign
[0018]
11, 21 electroacoustic transducer 12, 22 signal cable 13, 23 case 14, 24 waterproof rubber 25
acoustic entrance
04-05-2019
5
Документ
Категория
Без категории
Просмотров
0
Размер файла
13 Кб
Теги
jph099385
1/--страниц
Пожаловаться на содержимое документа