JP2642812B2 - Underwater transducer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater transmitter / receiver integrated with an underwater transmitter / receiver as a measuring instrument for measuring the reflectivity of a specimen in water by a pulse method. It is about a vessel.

[0002]

2. Description of the Related Art In the case of measuring the reflectivity of a specimen underwater by a pulse method at sea or the like, each of an underwater transmitter and an underwater receiver is used as a measuring device in addition to the specimen.
After setting the measurement distance separated by the distance defined by the distant sound field, they are arranged in a straight line and suspended at the required depth in the sea. Next, a conventional general measuring method is to transmit a pulsed sound wave from an underwater transmitter and receive an echo from a specimen underwater by an underwater receiver to collect data.

[0003]

In this case, depending on the size and frequency of the test piece, there is a case where the measurement is performed at a long measurement distance, and in such a case, the sound source level is not sufficient due to the ambient noise level. Higher underwater transmitters and more sensitive underwater receivers are desirable, and they greatly affect the accuracy and reliability of the measurements. Also, depending on the size of the underwater receiver suspended between the underwater transmitter and the specimen, it may not be possible to accurately measure the reflectivity of the specimen due to acoustic shadow. There is. For this reason, some measures have been taken, such as placing the underwater transmitter and underwater receiver at a concentric distance from the specimen.However, this method measures the specimen in an oblique direction. No results can be obtained. Also, there are more stormy weather on the sea than on calm sea level,
The work of suspending and extending the underwater receiver and test specimen individually requires many workers and required equipment such as a crane ship, which is expensive and has safety problems.
It has been strongly desired that the measurement frequency range be expanded by improving the transmission level of the underwater transmitter as a measuring instrument and that the underwater transmitter and the underwater receiver be reduced in size and weight.

An object of the present invention is to provide an underwater transmitter / receiver having a sound receiving unit integrated sound source structure for improving the performance of an underwater transmitter and realizing a smaller and lighter measuring instrument to solve the above problems. It is an object.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a submersible transducer containing an electroacoustic transducer, wherein the metallic housing of the submersible transducer is provided.
11 is formed in a substantially semi-elliptical cross section, and the piezoelectric ceramic 2
Are laminated, and an alternating voltage is applied thereto to excite the arc surface in the short axis direction of the housing to transmit the acoustic radiation surface 1 for transmitting waves.
A, a polymer piezoelectric material 4 for receiving a sound wave is mounted on the acoustic wave emitting surface 1A for wave transmission, and the wave transmitting portion including the acoustic emitting surface 1A and the polymer piezoelectric material 4 are mounted on the same surface. And a wave receiving portion made of the material 4 is superimposed.
The transmission signal line 3 and the reception signal line 5 are specially led out from holes provided at a distance from the flat bottom surface 1B facing the arc surface of the piezoelectric element 1. It is characterized in that a urethane rubber mold 8 is applied to the entire outer surface of the housing including the lead-out portions of the line 3 and the reception signal line 5 to form a watertight structure.

In order to realize a small, lightweight, high-power sound source with a low frequency, it is necessary to drive the acoustic radiation surface with a large amplitude.
A shell-type transmitter having a substantially semi-elliptical cross section is suitable. That is,
A piezoelectric ceramic having a structure that is laminated along the major axis direction is incorporated in a shell having a substantially semi-elliptical cross section made of metallic housing, and an alternating voltage is applied to the piezoelectric ceramic to excite the shell, thereby shortening the shell having a substantially semi-elliptical cross section. A high-output small and lightweight sound source is obtained by a mechanism for bending and vibrating an axial arc surface with a large amplitude. A high-sensitivity receiver is realized by mounting a polymer piezoelectric material 4 for receiving sound waves on the acoustic emission surface 1A in the short axis direction of a shell having a substantially semi-elliptical cross section. is there. The polymer piezoelectric material 4 is acoustically transparent and highly sensitive. Moreover, it is lightweight and flexible, can be easily cut, and can be mounted by overlapping according to the shape of the sound emitting surface 1A.

[0007]

The underwater transmitter / receiver of the present invention has a structure of an integrated sound source of a receiving part, so that a high-sensitivity receiver and a small and lightweight high-output sound source can be obtained. The underwater transmitter, the underwater receiver, and the suspension of the specimen required large-scale setup and preparation under three types of suspensions. However, in the present invention, a small and light-weighted receiver integrated sound source and the specimen are required. With only two sets of suspension, workability and measurement limitations are greatly reduced. In the case of measuring the reflectivity of a test object by the sound receiving unit integrated sound source of the present invention, the arrangement interval between the test object and the test object may be set to the position of the conventional underwater receiver.
By reducing the distance between the test sample and the sound source integrated with the receiving unit, the S / N (signal-to-noise) ratio increases, and higher-precision measurement becomes possible. In addition, in order to monitor the transmission level of the transmitted sound source, the conventional transmitter has the trouble of reinforcing the peripheral portion of the sound source and separately mounting a monitor receiver. The underwater transducer according to the present invention can be easily monitored by the piezoelectric polymer material, so that there is no complexity.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an underwater transducer according to the present invention will be described below with reference to the drawings. 1 and 2 are a partially cutaway perspective view and a cross-sectional view of an underwater transducer according to an embodiment of the present invention, which will be used to explain the embodiment. In the underwater transducer according to the embodiment, a wave transmitting element, that is, an electroacoustic transducer, which is built in a shell 1 having a substantially semi-elliptical cross section and constituting a metal housing 111 along a longitudinal direction thereof. By applying an alternating voltage from the transmission signal line 3 to the piezoelectric ceramic 2 to excite it, the arc surface of the shell 1 in the short-axis direction bends and vibrates with a large amplitude, and the acoustic emission surface 1A which becomes the arc surface of the shell 1 Transmits sound waves. Also shell 1
The receiving signal line 5 and the transmitting signal line 3 were derived from the flat bottom surface 1B of the above. Reference numeral 7 denotes a shell 1 at both ends of the laminated piezoelectric ceramic 2.
Is a connecting member that is connected to the inner wall in the long axis direction.

In order to receive an echo from a test sample, a polymer piezoelectric material 4 for receiving a sound wave is mounted on the acoustic radiation surface 1A, and an output voltage is detected from a reception signal line 5. In addition,
The transmission signal line 3 is connected to the laminated piezoelectric ceramic 2 through the metal housing 111, and the reception signal line 5 is connected to a lead wire of the polymer piezoelectric material 4. Further, the polymer piezoelectric material 4 as a wave receiving element on the outer peripheral surface is mounted by bonding or the like, and the entirety including the metal housing 111 is formed of a urethane rubber mold 8 for waterproofing or the like. The polymer piezoelectric material 4 and the urethane rubber mold 8 are acoustically transparent, and sound waves arriving by echoes from the specimen pass through the urethane rubber mold 8 and are captured by the polymer piezoelectric material 4, and a voltage proportional to the sound waves is generated. Induced. Further, the sound wave transmitted through the polymer piezoelectric material 4 is also transmitted to the shell 1 in the short-axis direction, and a vibration proportional to the incoming sound wave occurs. Along with this, mechanical strain is further generated in the polymer piezoelectric material 4. They are converted into electrical outputs, and an output voltage is obtained from the reception signal line 5 via a lead wire. In the figure, arrow a
The short axis vibration displacement, the arrow b is the long axis vibration displacement.
In this way, the transmission and reception of sound waves are separated, and
An underwater transmitter / receiver as a sound source integrated with a receiving unit, wherein the transmitting and receiving waves are on the same plane is obtained.

The underwater transducer according to this embodiment is provided with a plurality of underwater transducers such that the bottom surface 1B of the underwater transducer is mounted on the top of the gantry, so that a high-output integrated transducer is provided. Suitable for getting signals.

[0011]

As described above, according to the underwater transducer of the present invention, the high-molecular piezoelectric material 4 for receiving sound waves is mounted on the acoustic radiation surface 1A for transmission in a superposed state. Since the transmitting unit (sound source) and the receiving unit are integrally provided on the same surface, only two sets of the receiving unit-integrated sound source and the sample are suspended during measurement. In addition, restrictions on workability and measurement are greatly reduced. Further, a superimposed output voltage of both the pressure change applied to the polymer piezoelectric material 4 by the echo sound wave and the output voltage induced by the polymer piezoelectric material 4 due to the vibration distortion of the metal housing by the echo sound wave is obtained. Can be Therefore, in addition to high sensitivity, there is a great advantage that the S / N (signal-to-noise) ratio is improved, so that the signal processing is greatly improved. In addition, since the distance between the test sample and the sound receiving unit integrated sound source is reduced, the S / N ratio is increased, and there is an excellent effect that measurement with higher accuracy is possible. Further, a plurality of underwater transducers are connected to the bottom 1
By attaching the B side so as to be installed on the top of the gantry, it is possible to obtain an integrated high-output transmitted / received signal. Furthermore, since the transmission signal line and the reception signal line are led out from the hole provided at a position spaced apart from the flat bottom surface of the housing, electrical induction is avoided,
Since the diameter of this lead-out hole is also minimized, and the entire outer surface of the housing including the outer surface of the polymer piezoelectric material and the lead-out hole portion of the transmission signal line and the reception signal line is formed with a urethane rubber mold to have a watertight structure, Suitable for underwater transducers that can be used alone by hanging them in water in a water tank or test boat using cables, and are particularly excellent as underwater transducers for measurement at deep depths that require water pressure resistance. .

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of an underwater transducer according to an embodiment of the present invention.

FIG. 2 is a transverse sectional view of the same.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Shell, 1A sound emission surface, 1B flat bottom, 2 laminated piezoelectric ceramics, 3 transmission signal lines, 4 polymer piezoelectric materials, 5 reception signal lines, 7
Coupling member, 8 urethane rubber mold, 11
1 Housing.

Claims (1)

(57) [Claims] 1. An underwater transducer in which an electroacoustic transducer is accommodated, wherein a metal housing of the underwater transducer is formed in a substantially semi-elliptical cross section, and a major axis of the semi-elliptical cross section in the housing is provided. Piezoelectric ceramics are laminated and assembled along the direction, and an alternating voltage is applied thereto to excite the arc surface in the short axis direction of the housing to provide an acoustic radiation surface for transmitting waves, and on the acoustic radiation surface for transmitting waves Is mounted with a polymer piezoelectric material for receiving acoustic waves, and has a configuration in which a wave transmitting portion made of the acoustic radiation surface and a wave receiving portion made of the polymer piezoelectric material are superimposed on the same surface. , The distance of the flat bottom surface facing the arc surface of the housing
Transmit and receive signal lines are separated from holes provided at separate locations.
Separately , and connected to the outer surface of the polymer piezoelectric material and the transmission signal line.
The entire outer surface of the housing including the outgoing hole for the
An underwater transmitter / receiver characterized by having a watertight structure by applying a rubber mold .