JP2833258B2 - Underwater ultrasonic 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 ultrasonic transducer and, more particularly, to a flex tensional underwater ultrasonic transducer for transmitting and receiving low-frequency waves at a depth.

[0002]

2. Description of the Related Art As a low frequency and high power underwater ultrasonic transducer which is operated underwater at a frequency of several kHz or less, there is a flex tensional transducer as shown in FIG. (For example, US Pat. 3, 277, 433) The transducer shown in FIG. 3 includes an elliptical shell 1, an active column 2 and an end plate 3, and the longitudinal vibration of the active column 2 causes the end plate 3 to move. The sound is transmitted to the elliptical shell 1 and the elliptical shell 1 bends and vibrates, so that sound waves are emitted into the water.

[0003]

In the above-mentioned conventional underwater ultrasonic transducer, the piezoelectric or magnetostrictive material constituting the active columnar body is weak against tensile stress, and usually, the tensile force acting on the vibrator at the time of excitation is obtained. A compressive force is applied to the vibrator in advance to cancel the stress. However, in the conventional flex tensional type transducer, when hydrostatic pressure is applied to the elliptical shell, the elliptical shell is stretched in the long axis direction, and a tensile stress acts on the active columnar body. This phenomenon will be described with reference to FIG. 3. When hydrostatic pressure is applied to the elliptical shell 1, a force F1 acts on the shell due to the shell shape. The power of this F1 is
It is the force of F2 that stretches the shell in the longitudinal direction. The force of F2 becomes the force of F4 at the vibrator end of the active columnar body 2, and becomes the vibrator tensile force.

For this reason, when the transducer is driven at a deep depth, if the sum of the tensile force applied to the vibrator by the hydrostatic pressure and the tensile force at the time of excitation exceeds the tensile stress limit of the vibrator, mechanical destruction occurs in the vibrator. There is a drawback of getting up.

An object of the present invention is to provide an underwater ultrasonic transducer which eliminates the above-mentioned disadvantages and does not cause mechanical damage to the vibrator even at a deep depth.

[0006]

An underwater ultrasonic transducer according to the present invention is a flex tensional type underwater ultrasonic transducer, wherein a vibrating body using a piezoelectric material or a magnetostrictive material inside an elliptical shell is provided. The vibrating direction of the active columnar body is made to coincide with the major axis direction of the elliptical shell, a gap is provided therein, and one end is fixed to each of end plates attached to both end surfaces of the active columnar body in the vibrating direction. At least one pair of bolts penetrates the active columnar body and the end plate on the opposite side and is fixed to both long axis ends of the elliptical shell.

The underwater ultrasonic transducer according to the present invention has a structure in which the arrangement direction of the at least one pair of bolts matches the vibration direction of the active columnar body and is spatially vertically parallel.

[0008]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of one embodiment of the present invention.

The embodiment shown in FIG. 1 includes an elliptical shell 1, an active columnar body 2 using a piezoelectric material or a magnetostrictive material which is provided with a gap in the elliptical shell 1 and whose vibration direction coincides with the longitudinal direction and which is contained therein. End plates 3 disposed at both ends of the active column 2 in the vibration direction, and one end plate 3 penetrates the active column 2, further penetrates the other end plate, and is fixed to the long axis end of the elliptical shell. It is provided with at least one pair of bolts 4 which are vertically parallel in space and two pairs in this embodiment.

Next, the operation of the underwater ultrasonic transducer according to this embodiment will be described.

By applying an electric signal to the active column 2, a longitudinal vibration coincident with the major axis direction of the elliptical shell 1 is excited. The vibration amplitude of the active columnar body 2 is controlled by the bolts 4 from the end plates 3 attached to both ends thereof.
And transmitted to the elliptical shell 1 on the opposite side to the end plate, and radiated as sound waves into water.

Next, the operation under hydrostatic pressure will be described. FIG.
In this case, when a hydrostatic pressure of force F1 is applied to the elliptical shell 1, the elliptical shell 1 is deformed in the long axis direction, and a force of F2 acts on the bolt 4. This force F2 is transmitted to the bolt 4, becomes a force of a pair of F3 at the end plate 3, and provides a force for compressing the active columnar body 2.

Since the active column 2 has a high stress limit against such a compressive force, the influence of the hydrostatic pressure is significantly suppressed.

[0015]

As described above, according to the present invention, both ends of the active columnar body of the flex tensional type underwater ultrasonic transducer are attached to the opposite elliptical shell ends via bolts with a gap provided therebetween. By applying a force to the compression side of the active column where the stress limit is high even when the hydrostatic pressure is applied, the effect of the hydrostatic pressure is remarkably suppressed, and the active column is used while avoiding mechanical destruction of the active column even at deep depths There is an effect that a high-powered underwater ultrasonic transducer of a flexible tension type can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view of one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view for explaining stress generated under hydrostatic pressure in the embodiment of FIG.

FIG. 3 is a longitudinal sectional view of a conventional flex tensional type transducer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Oval shell 2 Active pillar 3 End plate 4 Bolt

Claims (2)

(57) [Claims] 1. A of flextensional submersible ultrasonic transducer, wherein the <br/> vibration direction active columnar body as a vibration body using a piezoelectric material or magnetostrictive material in the interior of the elliptical shell At least one pair of bolts having one end fixed to each of end plates attached to both end faces in the vibration direction of the active columnar body, the at least one pair of bolts being aligned with the major axis direction of the elliptical shell and being provided with a gap, and An underwater ultrasonic transducer having a structure penetrating opposite end plates and fixed to both long-axis ends of the elliptical shell. 2. The underwater ultrasonic wave according to claim 1, wherein the directions in which the at least one pair of bolts are arranged coincide with the vibration direction of the active columnar body and are spatially vertically parallel. Transducer.