JPH08275285A - Composite vibrator and array - Google Patents

Abstract

PURPOSE: To realize a broad band width and a high conversion efficiency with a simple structure in the composite vibrator employing transverse vibration or longitudinal vibration. CONSTITUTION: Plural holes 3 are made to an active vibrator 1 in a direction in parallel with the vibrating direction in the composite vibrator formed by fitting masses 2A, 2B to both sides of the active vibrator 1 utilizing a piezoelectric member such as a piezoelectric ceramic. Then the equivalent mass of the vibrator is decreased and the equivalent compliance is increased to execute a broad band width. Thus, the active vibrator 1 is in contact uniformly with the masses 2A, 2B to exclude locally concentrated contact and efficient sound radiation is attained through ideal parallel vibration of the masses 2A, 2B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite oscillator and array utilizing thickness vibration or longitudinal vibration, and more particularly to a composite oscillator and array used for underwater acoustic detectors such as sonars requiring a wide bandwidth. Related to transducers and arrays.

[0002]

2. Description of the Related Art A conventional composite type vibrator of this type has a structure as shown in FIG. The composite vibrator shown in FIG. 3 has an active vibrating body 21 and a pair of mass bodies 22A and 22B coupled to both ends thereof.
In order to realize a wide bandwidth in such a composite oscillator, it is necessary to reduce the mechanical resonance Q (mechanical Q) of the oscillator.

The mechanical Q is Q = ωL / R or Q = 1 /
It is represented by ωCR. Where ω is the angular frequency, L is the equivalent mass of the oscillator, C is the equivalent compliance of the oscillator, and R is the sum of the internal resistance R ₀ of the oscillator and the acoustic radiation resistance R ₁ .
Generally, the internal resistance R ₀ of the vibrator is extremely small and can be ignored. Further, the acoustic radiation resistance R ₁ is a value determined corresponding to the acoustic radiation area of the vibrator.

Therefore, in order to reduce the mechanical Q, it is necessary to reduce the equivalent mass or increase the equivalent compliance. In the conventional composite type vibrator, a cylindrical active vibrating body mainly composed of a piezoelectric member such as ceramics is used. The equivalent mass is reduced and the equivalent compliance is increased by reducing the thickness or reducing the wall thickness.

[0005]

In this conventional composite vibrator, since the contact between the active vibrating body and the mass body is concentrated in a part, the mass body does not make uniform parallel vibration, and thus the mass vibrating body shown in FIG. When the bending mode as shown in (1) is generated, the amount of excluded medium due to vibration is reduced, and there is a problem that efficient acoustic radiation is not performed.

When a large number of composite type vibrators are arranged on a plane to form an array, a complicated process of accurately arranging and assembling individually assembled composite type vibrators on a backing material is required. There was a problem that it was necessary.

The object of the present invention is to solve the above-mentioned problems,
A simple configuration that eliminates partial concentration of contact between the active vibrating body and the mass body, uniformly contacts the active vibrating body with the entire mass body, gives ideal parallel vibration to the mass body, and efficiently emits acoustic waves. It is to provide a composite oscillator.

[0008]

The present invention has the following means for achieving the above object. That is, the composite vibrator of the present invention is a composite vibrator in which a mass body is attached to both surfaces in the vibration direction of an active vibrating body composed of a piezoelectric member such as a piezoelectric ceramic, and is parallel to the vibration direction of the active vibrating body. A plurality of holes are arranged in parallel in different directions.

Further, in the composite vibrator of the present invention, the active vibrating body having the plurality of holes arranged in parallel and the mass bodies attached to both surfaces in the vibration direction of the active vibrating body are coupled in the same facing area. It has a different configuration.

Further, the composite vibrator array of the present invention is formed by planarly arranging composite vibrators in which mass bodies are attached to both surfaces in the vibration direction of an active vibrator composed of a piezoelectric member such as a piezoelectric ceramic. The composite oscillator having the same vertical and horizontal external dimensions as the desired composite oscillator array to be formed is integrally formed in advance, and the opposite side of the acoustic radiation surface is adhered and fixed to the backing member, and then the integrated composite vibration is formed. It has a configuration in which only the child is divided and cut in a predetermined equal number of divisions in both the vertical and horizontal directions.

[0011]

The function of the present invention will be described below. In order to provide a transducer for underwater acoustic equipment such as a sonar, a conventional composite vibrator configured to secure a wide frequency bandwidth has a structure in which mass bodies are added to both ends in the vibration direction. . To widen the frequency bandwidth of such a composite oscillator, it is necessary to reduce the mechanical Q. For this purpose, either reduce the equivalent mass associated with the vibration system or increase the equivalent compliance. Is required.

Corresponding to this condition, in the conventional composite type vibrator, the equivalent mass is reduced by making the cylindrical active vibrating body composed of a piezoelectric member such as ceramic thin or making it thin. And increased compliance.

However, according to the above-mentioned configuration, the contact between the active vibrating body and the additional mass body is inevitably partially concentrated, the mass body does not perform uniform parallel vibration, and the amount of the medium to be excluded by the vibration is reduced. Decreased,
This causes a reduction in the efficiency of acoustic radiation.

Further, although such a composite type vibrator is often operated as an array by arranging a plurality of planes in a plane, it is complicated to accurately arrange and bond the plurality of composite type vibrators to a backing material. It was a process.

According to the present invention, the active vibrating body is provided with a plurality of holes in parallel with the vibrating direction thereof, and the mass bodies added to both ends in the vibrating direction of the active vibrating body have the same facing area as that of the active vibrating body. In this way, partial concentrated contact between the active vibrating body and the mass body is eliminated, and efficient acoustic radiation is secured. Further, by adopting such a configuration, it is possible to remarkably facilitate the process even when configured as an array.

[0016]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a side view and a sectional view showing the configuration of a first embodiment of the composite vibrator of the present invention. The active vibrating body 1 of this embodiment is externally set to have substantially the same dimensions as the acoustic radiation surfaces of the mass bodies 2A and 2B, and has a configuration in which a plurality of holes 3 are arranged in a direction parallel to the vibration direction. Have.

With such a structure, the active vibrator 1 has a reduced volume, a reduced equivalent mass and an increased equivalent compliance, whereby the mechanical Q is reduced and a wide bandwidth can be obtained. Further, since the active vibrating body 1 uniformly contacts the entire mass bodies 2A and 2B, the mass bodies 2A and 2B perform ideal parallel vibration, and efficient acoustic radiation can be realized.

FIG. 2 is a perspective view showing the configuration of the second embodiment of the present invention. The second embodiment shown in FIG. 2 shows a structure in which a large number of the same oscillators are arranged on the same plane to form an array. In this case, a vibrator having the same structure as that shown in FIG. 1 is once integrally formed corresponding to the required size of the array, and then the mass body 12 on the surface opposite to the acoustic radiation surface is formed.
A backing material is attached to B by adhesion or the like, and the vibrator portion excluding the backing material 4 is cut by a cutter such as a diamond cutter in predetermined vertical and horizontal equal divisions, whereby the active vibrating body 11 and the pair of mass bodies 12A,
A plurality of vibrators composed of 12B are independently used as the backing material 4
Realizes the array structure attached to.

As described above, by uniformly contacting the active vibrating body with the entire mass body to eliminate partial concentration of the contact, ideal parallel vibration can be given to the mass body, and efficient acoustic radiation can be achieved. It is possible to secure the same, and it is possible to remarkably simplify the process in the case of array configuration.

[0020]

As described above, according to the present invention, in a composite type vibrator in which a mass body is attached to both surfaces of an active vibrating body made of a piezoelectric member such as a piezoelectric ceramic, a plurality of active vibrating bodies are provided in a direction parallel to the vibration direction. By providing the holes in the above, the equivalent mass of the vibrator can be reduced, the equivalent compliance can be increased to reduce the mechanical Q, a wide bandwidth can be obtained, and the active vibrator can be made uniform with the entire mass body. It is possible to make contact with the body and to perform ideal parallel vibration in the mass body, thereby ensuring efficient acoustic radiation. Further, there is an effect that the remarkable simplification of the steps in the array configuration can be ensured.

[Brief description of drawings]

FIG. 1 is a side view and a cross-sectional view showing a configuration of a first embodiment of a composite vibrator of the present invention.

FIG. 2 is a perspective view showing the configuration of a second embodiment of the composite vibrator of the present invention.

FIG. 3 is a side view and a cross-sectional view showing a configuration of a conventional composite vibrator.

[Explanation of symbols]

 1 Active Vibration Body 2A Mass Body 2B Mass Body 3 Hole 4 Backing Material 11 Active Vibration Body 12A Mass Body 12B Mass Body 21 Active Vibration Body 22A Mass Body 22B Mass Body

Claims (3)

[Claims] 1. A composite type vibrator having a mass body attached to both sides in the vibration direction of an active vibrating body composed of a piezoelectric member such as a piezoelectric ceramic, wherein a plurality of holes are provided in a direction parallel to the vibrating direction of the active vibrating body. A composite type vibrator characterized by arranging in parallel. 2. The active vibrating body having the plurality of holes arranged in parallel, and the mass body mounted on both sides of the active vibrating body in the vibration direction are coupled to each other in the same facing area. The described hybrid oscillator. 3. A desired composite oscillator array to be configured by planarly arranging composite oscillators having mass bodies attached to both surfaces in the vibration direction of an active oscillator made of a piezoelectric member such as a piezoelectric ceramic. A composite type vibrator having vertical and horizontal external dimensions is integrally formed in advance, and the opposite side of the acoustic radiation surface is adhered and fixed to a backing member. A composite transducer array, which is configured by dividing and cutting by the number of divisions.