JP2004104481A - Bent transmitter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bent transmitter transmitting a horizontal direction nondirectional wave in a plurality of frequency bands of low frequencies. <P>SOLUTION: The bent transmitter 1 is provided with a pair of metallic disks 2a and 2b which are oppositely disposed, disk-like vibration members 6a and 6b connected to the disks 2a and 2b, active vibrators 3a and 3b formed of piezoelectric porcelain buried on outer surface sides of the disks 2a and 2b, an O ring 5 sandwiched with edge parts of the disks 2a and 2b and spring bands 7 holding the disks 2a and 2b. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a bending type transmitter which emits sound waves into water by bending vibration of a disk-shaped vibrator, which is used for long-distance sonar, marine resource survey, etc., and has a plurality of transmission frequency bands in a low frequency range. The present invention relates to a bent-type transmitter having a horizontal direction and omnidirectional transmission.
[0002]
[Prior art]
Sound waves of low frequency (for example, a frequency of several kilohertz) in water have lower propagation loss than those of high frequency, and can reach farther. For this reason, a bent-type transmitter has been developed as a low-frequency sound wave transmitter, and has been used for sonar, marine resource exploration, and the like.
In addition, an active vibrator made of a piezoelectric ceramic is usually used for the above-mentioned bending type transmitter, so that the vibration amplitude of the piezoelectric ceramic is further expanded, and a high-frequency acoustic radiation with a low frequency is obtained from the disk-shaped vibrator. A variety of techniques have been developed for performing this.
[0003]
(Conventional example)
Next, a conventional bent type transmitter will be described with reference to the drawings.
14A and 14B are schematic diagrams for explaining the structure of a main part of a bent type transmitter according to a conventional example, where FIG. 14A is a plan view and FIG. 14B is a cross-sectional view taken along line EE. ing. In the figure, a bent type transmitter 101 is an active type comprising a pair of metal discs 102a and 102b disposed to face each other, and piezoelectric ceramics buried respectively on the outer surfaces of the discs 102a and 102b. It is composed of vibrating bodies 103a and 103b, an O-ring 105 sandwiched between the edges of the discs 102a and 102b, and a spring band 107 sandwiching the discs 102a and 102b.
[0004]
Each of the active vibrators 103a and 103b is formed of a circular thin plate-shaped piezoelectric ceramic. The piezoelectric ceramic is polarized in a thickness direction, and a voltage is applied along the polarization direction. Radial spreading motion is excited. Note that wirings for applying a voltage and the like are omitted for easy understanding.
Each of the active vibrators 103a and 103b is buried in a concave portion formed on the outer surface side of each of the disks 102a and 102b, and is bonded and fixed with an adhesive such as an epoxy resin.
[0005]
Each of the disks 102a and 102b has a disk shape having the above-described concave portion, and an annular groove for positioning the O-ring 105 is provided at an edge of a surface opposite to the concave portion. The depth of the groove is a depth that can secure a gap 151 necessary for the discs 102a and 102b to perform a bending motion in a state where the bending type transmitter 101 is assembled.
The pair of disks 102a and 102b are disposed so as to face each other such that the active vibrators 103a and 103b face the outer surface, and are connected to the spring band 107 and the bolt 171 with the O-ring 105 interposed therebetween. I have.
Note that a metal such as Al (aluminum) is used as a material of the disks 102a and 102b.
[0006]
The O-ring 105 as the vibration member is made of a high-strength material such as maraging steel, and vibrates due to the bending motion of the disk-shaped vibration members 104a and 104b including the disks 102a and 102b and the active vibration members 103a and 103b. This prevents the amplitude from being attenuated.
[0007]
The spring band 107 is formed by bending a rectangular metal plate into a U-shape when viewed from the side, and has bolt holes through which bolts 171 are passed through upper and lower plates. Further, the spring band 107 has a structure in which the side plates are elastically deformed and easily bendable, so that the disk-shaped vibrators 104a and 104b can be connected without hindering the bending vibration of the disk-shaped vibrators 104a and 104b.
The outer surface of the bent type transmitter 101 is covered with an outer sheath 110 made of urethane resin or the like to protect the bent type transmitter 101 with water and nectar.
[0008]
Next, the operation of the bent type transmitter 101 having the above configuration will be described with reference to the drawings.
FIG. 15 is a schematic cross-sectional view of a main part for describing a primary bending vibration mode of a bending type transmitter according to a conventional example.
FIG. 16 is a schematic cross-sectional view of a main part for describing a tertiary bending vibration mode of the bending type transmitter according to the conventional example.
[0009]
As shown in FIG. 15, the bending type transmitter 101 applies a voltage signal having the same frequency as the primary natural frequency (for example, point P in FIG. 2) to the active vibrators 103a and 103b. When applied, the disk-shaped vibrators 104a and 104b resonate symmetrically in the primary bending vibration mode.
Here, in the primary bending vibration mode, the center portions of the disk-shaped vibrators 104a and 104b are bent to the adjacent outer surface side from the stationary state, and the disk-shaped vibrators 104a and 104b are deformed into a convex shape ( Subsequently, the center portion bends in a direction opposite to the adjacent outer surface side (inner surface side), and the disk-shaped vibrators 104a and 104b are repeatedly deformed (not shown). Vibration mode.
[0010]
Further, as shown in FIG. 16, the bending type transmitter 101 applies a voltage having the same frequency as the tertiary natural frequency of the bending type transmitter 101 (for example, point R in FIG. 2) to the active vibrators 103a and 103b. When a signal is applied, the disk-shaped vibrators 104a and 104b resonate symmetrically in the third-order bending vibration mode.
Here, the tertiary bending vibration mode is such that the central portions of the disk-shaped vibrators 104a and 104b bend from the stationary state to the inner surface side, and the central portions and the edge portions of the disk-shaped vibrators 104a and 104b. The vibration in which the annular portion between the adjacent portions bends toward the adjacent outer surface side (see FIG. 16), and then the central portion bends toward the adjacent outer surface side and the annular portion bends toward the inner surface side is repeated. Mode. That is, the disk-shaped vibrators 104a and 104b deform so as to undulate radially.
Note that the bent-type transmitter 101 can obtain an acoustic output when the disk-shaped vibrators 104a and 104b mechanically resonate in a third-order bending vibration mode.
[0011]
As described above, in the bent type transmitter 101, the discs 102a and 102b are connected via the O-ring 105. When the cross section is viewed (see FIG. 15), the ends of the discs 102a and 102b are dotted. Since it is in the supported state, it is easy to be angularly displaced, so that the natural frequencies of the disk-shaped vibrators 104a and 104b are reduced, and low-frequency transmission can be performed.
Further, by being supported at points, the amplitude of the bending vibration of the disk-shaped vibrators 104a and 104b is increased, and high power can be achieved.
Further, since the active vibrators 103a and 103b are embedded in the disks 102a and 102b, it is possible to realize a reduction in thickness and weight (for example, see Patent Document 1).
[0012]
Next, as another conventional technique of the bending type transmitter, for example, a bending disk type resonator composed of an active disk body and a metal disk is joined to each opening of both ends of the Helmholtz type resonator one by one. By matching the natural frequencies of the cavity resonator and the bent disk resonator, filling the interior of the cylinder of the Helmholtz resonator with oil, and compensating for external pressure, high-power radiation (high There is a bent type transmitter capable of performing output radiation (for example, see Patent Document 2).
[0013]
[Patent Document 1]
Japanese Patent Application Laid-Open No. Hei 5-344581 (Claims 1, 2 and Claims)
[Patent Document 2]
JP-A-6-31577 (Claim 1)
[0014]
[Problems to be solved by the invention]
However, the above-mentioned bending type transmitter can emit low-frequency acoustic radiation by resonating the disk-shaped vibrator at the primary natural frequency of the disk-shaped vibrator, but the primary natural vibration Since the number is determined by the material, size, shape, etc. of the disk-shaped vibrator, there is a problem that the frequency band in which a transmission level above a certain level can be obtained, that is, only one resonance frequency exists in the low frequency range. there were.
[0015]
That is, since one bending type transmitter has only one resonance frequency in a low frequency range, for example, in marine resource exploration, to transmit a plurality of sound waves, the number of bending type waves is the same as the number of sound waves. It was necessary to prepare a transmitter. In the sonar, in order to transmit a plurality of sound waves for the purpose of distinguishing the reverberation sound, it is necessary to provide the same number of bent type transmitters as the number of the sound waves, and to reduce the size and weight of the sonar. There was a problem that it was not possible.
[0016]
In addition, the conventional bent-type transmitter has a certain or higher transmission level in two or more frequency bands by resonating the disc-shaped vibrator at a higher natural frequency of the disc-shaped vibrator. Although a sound wave can be transmitted, there is a problem that in the bending vibration mode of the disk-shaped vibrator at a higher natural frequency, it is not possible to transmit a non-directional wave in the horizontal direction.
[0017]
SUMMARY OF THE INVENTION The present invention has been proposed to solve the above-mentioned problems of the related art, and has a plurality of low-frequency frequency bands. The purpose is to provide.
[0018]
[Means for Solving the Problems]
In order to achieve the above object, the bent type transmitter according to the present invention is configured such that a pair of disk-shaped vibrators made of an active vibrating body that expands and contracts and a disc are disposed to face each other via a supporting member, Is a bending-type transmitter that transmits a pressure wave by causing the disk-shaped vibrator to resonate symmetrically in a primary bending vibration mode, and is connected to the disk, and vibrates in the vibration direction of the disk. And a vibrating member.
With this configuration, the vibrating member can be vibrated in the same phase or in the opposite phase to the disk, so that the active vibrator and the disk are subjected to the primary bending vibration mode at a frequency opposite to the above-mentioned frequency. Can be resonated. That is, the bent type transmitter can transmit a sound wave having non-directionality in the horizontal direction in a plurality of low frequency bands.
[0019]
Further, the bending type transmitter according to the present invention has a configuration in which the vibrating member has a disk shape and a gap is provided between the vibrating member and the disk, so that the structure of the vibrating member is simplified. , And can be easily designed and manufactured.
Further, the bent type transmitter according to the present invention has a configuration in which the gap is hollow, and similarly, design and manufacture can be easily performed.
In addition, in the present specification, the circular sky refers to a space formed in a circular concave portion when viewed from above.
[0020]
Further, the bending type transmitter according to the present invention has a configuration in which the vibrating member is integrally formed with the disk, and thus, the manufacturing cost of the disk and the vibrating member can be reduced.
[0021]
In addition, the bending type transmitter according to the present invention has a configuration in which the vibration member is connected to the disk by welding, bonding, and / or a mechanical connection member. Even when the vibration member cannot be integrally formed, it can be manufactured.
[0022]
Further, the bent type transmitter according to the present invention has a configuration in which a plurality of the vibration members are connected to the disk, and the plurality of vibration members can be vibrated in the same phase or in the opposite phase to the disk-shaped vibration body. Thus, sound waves having horizontal omnidirectionality can be transmitted in more frequency bands of low frequencies.
Further, the bent type transmitter according to the present invention has a configuration in which the shapes, dimensions and / or materials of the plurality of vibrating members are different, so that a plurality of low frequency bands can be easily set. be able to.
[0023]
Further, the bending type transmitter according to the present invention has a configuration in which the plurality of vibration members are stacked and connected to the disk. In this case, even if the disk-shaped vibration member is used, a low-frequency Sound waves having horizontal omnidirectionality can be transmitted in more frequency bands. Further, the bent type transmitter according to the present invention may be configured such that the plurality of vibrating members are arranged in the same plane. Sound waves having directivity can be transmitted.
Further, the bent type transmitter according to the present invention has a configuration in which the support member is formed in a cylindrical shape, so that a plurality of vibration members can be efficiently stored inside the support member.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a preferred embodiment of a bent type transmitter according to the present invention will be described with reference to the drawings.
[0025]
[First embodiment]
1A and 1B are schematic diagrams for explaining a structure of a main part of a bent type transmitter according to the first embodiment, in which FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along line AA. Is shown.
In FIG. 1, a bent type transmitter 1 includes a pair of metal discs 2a and 2b disposed to face each other, and disc-shaped vibration members 6a and 6b respectively connected to the discs 2a and 2b. And active vibrators 3a and 3b made of piezoelectric ceramics buried respectively on the outer surfaces of the disks 2a and 2b, an O-ring 5 sandwiched between the edges of the disks 2a and 2b, and the disks 2a and 2b. It consists of a spring band 7 to be clamped.
[0026]
The vibrating members 6a and 6b are disc-shaped, and have a structure in which a peripheral edge portion is connected to inner surfaces of the discs 2a and 2b via hollow spaces 52a and 52b, respectively. The vibrating members 6a, 6b are integrally formed with the disks 2a, 2b, respectively, and although not shown, holes for extracting cores for forming the gaps 52a, 52b are provided with vibrating members 6a, 6b and / or. Alternatively, they are formed on the disks 2a and 2b.
[0027]
In addition, the bending type transmitter 1 adjusts the diameter D of the support member 5 and the thickness T2 of the vibration members 6a and 6b (for example, by performing a simulation by a vibration analysis program using a finite element method). ), The mechanical resonance frequencies of the disk-shaped vibrators 4a and 4b (consisting of the disks 2a and 2b, the vibrating members 6a and 6b, and the active vibrators 3a and 3b, respectively). The resonance frequency (for example, point P in FIG. 2) can be set.
Further, by adjusting the diameter dimension d of the gaps 52a and 52b, the thickness T1 of the discs 2a and 2b, and the ratio of the thickness T1 to the thickness t of the active vibrators 3a and 3b, the disc shape is obtained. A mechanical resonance frequency of the vibrators 4a and 4b, specifically, a second resonance frequency (for example, point Q in FIG. 2) can be set.
Other configurations are almost the same as those of the bent type transmitter 101 in the conventional example.
[0028]
Next, the operation of the bent type transmitter 1 having the above configuration will be described with reference to the drawings. FIG. 3 is a schematic cross-sectional view of a main part for describing a primary bending vibration mode at a first resonance frequency of the bending type transmitter according to the first embodiment.
FIG. 4 is a schematic cross-sectional view of a main part of the bending-type transmitter according to the first embodiment for explaining a primary bending vibration mode at a second resonance frequency.
[0029]
As shown in FIG. 3, when the bending type transmitter 1 applies a voltage signal having the same frequency as the first resonance frequency (for example, point P in FIG. 2) to the active vibrators 3a and 3b, the disk 2a , 2b (including the active vibrators 3a, 3b, respectively) resonate symmetrically in the primary bending vibration mode and radiate sound waves in the vertical direction of the bending type transmitter 1.
At this time, the vibrating members 6a and 6b flex and vibrate in the same direction as the disks 2a and 2b (including the active vibrators 3a and 3b, respectively) with the support member 5 as a fulcrum.
That is, the primary bending vibration mode at the first resonance frequency means the disk 2a (2b), the active vibrator 3a (3b), and the vibrating member 6a (6b) constituting the disk-shaped vibrator 4a (4b). Is a mode in which bending vibration is performed in the same direction.
[0030]
On the other hand, as shown in FIG. 4, the bending type transmitter 1 applies a voltage signal having the same frequency as the second resonance frequency (for example, point Q in FIG. 2) to the active vibrators 3a and 3b. The disks 2a and 2b (including the active vibrators 3a and 3b, respectively) resonate symmetrically in the primary bending vibration mode, and radiate sound waves in the vertical direction of the bending type transmitter 1.
At this time, the vibrating members 6a and 6b bend and vibrate in directions opposite to the disks 2a and 2b (including the active vibrators 3a and 3b, respectively) with the outer diameter positions of the gaps 52a and 52b as fulcrums.
That is, the primary bending vibration mode at the second resonance frequency means that the disk 2a (2b) and the active vibration body 3a (3b) constituting the disk-shaped vibration body 4a (4b) bend and vibrate in the same direction, In this mode, the vibration member 6a (6b) bends and vibrates in the opposite direction.
[0031]
As described above, in the bending type transmitter 1 according to the first embodiment of the present invention, the disk-shaped vibration members 6a, 6b are provided on the inner surface sides of the disks 2a, 2b via the gaps 52a, 52b. By vibrating the vibrating members 6a, 6b in the same direction as the bending vibration of the disks 6a, 6b or in the opposite direction, two frequency bands in which low-frequency sound waves can be emitted can be obtained.
Further, since the resonance generated at the second resonance frequency (for example, point Q in FIG. 2) is a vibration in the first-order bending vibration mode (FIG. 4), the bending type transmitter 1 is almost equal to the acoustic radiation surface. A distribution of sound waves can be emitted.
[0032]
Further, in the bent type transmitter 1, the vibrating members 6a and 6b are formed in a disk shape, and the hollow spaces 52a and 52b are provided, so that the structures of the vibrating members 6a and 6b and the spaces 52a and 52b are simplified. Therefore, design and manufacture can be easily performed.
Furthermore, the bending type transmitter 1 has a configuration in which the vibration members 6a, 6b are integrally formed with the disks 2a, 2b. In this case, the manufacturing costs of the disks 2a, 2b and the vibration members 6a, 6b are reduced. Down can be planned.
[0033]
<Example of use>
The bent type transmitter 1 of this embodiment was manufactured, and the frequency characteristics of the transmission sensitivity and the like were measured.
The manufactured bent-type transmitter 1 uses lead zirconate titanate-based piezoelectric ceramics as the active vibrators 3a and 3b, and includes discs 2a and 2b made of an aluminum alloy, vibrating members 6a and 6b, and stainless steel. The support member 5 is used.
Further, when the standardized frequency f, sound velocity C, and λ = C / f are set, D = 0.14λ, d = 0.10λ, t = 0.195D, T1 = 0.195D, T2 was set to 0.029D.
[0034]
This bent type transmitter 1 has the above-described two resonance systems (resonance systems at the first resonance frequency and the second resonance frequency), and the frequency characteristics of the transmission voltage sensitivity are as shown in FIG. As shown by the solid line, a characteristic having two resonance frequencies (points P and Q) was shown. That is, according to the frequency characteristics of the transmission voltage sensitivity obtained by the conventional bending-type transmitter 101 (see the broken line in FIG. 2), the resonance of the disk-shaped vibrators 104a and 104b in the higher-order bending vibration mode shown in FIG. The second resonance frequency (point Q) was obtained in a frequency band lower than the frequency (point R).
[0035]
In addition, the conventional bent-type transmitter 101 transmits waves at the second resonance frequency (point R) in the higher-order mode (see FIG. 16) of the disk-shaped vibrators 104a and 104b. Directivity occurred in the direction, and the sound pressure in the horizontal direction was significantly reduced.
On the other hand, as shown in FIG. 5, the bent-type transmitter 1 of this usage example was able to perform uniform transmission in all directions at the first resonance frequency. Further, as shown in FIG. 6, even at the second resonance frequency, although a deviation of several dB or less occurs in an arbitrary direction (vertical direction), it is possible to perform substantially uniform transmission in all directions. did it.
That is, since the bending type transmitter 1 is in the first bending vibration mode of the disks 2a and 2b (including the active vibrators 3a and 3b, respectively) at the first and second resonance frequencies, the acoustic radiation surface Radiated almost equally distributed sound waves, and could transmit non-directional and high-power sound waves in all directions.
[0036]
[Second embodiment]
FIGS. 7A and 7B are schematic diagrams for explaining the structure of the main part of the bent type transmitter according to the second embodiment, where FIG. 7A is a plan view and FIG. 7B is a cross-sectional view taken along line BB. Is shown.
As shown in the figure, in the present embodiment, in the first embodiment described above, instead of the integrally formed vibration members 6a and 6b, the vibration members 61a and 61b made of a disc are replaced by bolts 72 and nuts 73. And connected to the disks 21a, 21b.
[0037]
Specifically, as shown in the figure, the bent type transmitter 1d according to the present embodiment has a hollow recess at the center of the inner surface of the disks 21a and 21b. Is covered with the vibration members 61a and 61b, thereby forming the gap 52a and the vibration members 61a and 61b.
[0038]
Further, the vibrating members 61a and 61b are provided with a bolt hole for inserting the bolt 72 at a peripheral edge thereof so as to be equally divided into eight in the circumferential direction, and further, at a position where each bolt hole is rotated by 22.5 degrees, A recess for positioning a steel ball 5d as a support member is formed.
Then, the disks 21a and 21b and the vibration members 61a and 61b are assembled so as to face each other via the ball 5d, and are mechanically connected by bolts 72 and nuts 73. In this manner, the disks 21a and 21b can be supported at points without using the O-ring 5, and the bending vibration can be smoothly performed.
The other configurations and operations of the bent-type transmitter 1d of the present embodiment are the same as those of the bent-type transmitter 1 of the first embodiment.
[0039]
As described above, since the bending type transmitter 1d according to the present embodiment is configured to mechanically connect the vibration member 61a to the disks 21a and 21b, the dimensional accuracy of the gap 52a and the like can be increased, and the circular shape can be improved. The plates 21a and 21b can be made to resonate more symmetrically, and a precise sound wave can be transmitted.
Further, for example, even when the shapes of the vibrating members 61a and 61b are complicated and the disks 21a and 21b and the vibrating members 61a and 61b cannot be integrally formed, the vibration members 61a and 61b can be easily manufactured.
The connection between the disks 21a and 21b and the vibration members 61a and 61b is not limited to the connection using a mechanical connection member, but may be, for example, welding (including brazing) or epoxy resin. Needless to say, the connection using an adhesive may be used.
[0040]
[Third embodiment]
FIG. 8 is a schematic top view illustrating the structure of the vibration member of the bending type transmitter according to the third embodiment.
As shown in the drawing, in the present embodiment, in the second embodiment described above, instead of the disk-shaped vibrating members 61a and 61b, the central portion is vacated by notch processing, and from the peripheral portion toward the center. The vibrating members 62a and 62b (not shown) provided with four vibrating pieces are provided.
[0041]
Specifically, as shown in the figure, the vibrating member 62a has four vibrating pieces projecting in a point-symmetric and left-right symmetrical shape, and these vibrating pieces are attached instead of the vibrating members 61a and 62b. Vibrates in the bending vibration direction.
Further, since each resonator element has the same shape, material (specifically, material properties related to the natural frequency such as density, rigidity, Poisson's ratio, etc.) and size, the natural frequency is the same. Becomes the same.
Other configurations and operations of the bent type transmitter of the present embodiment are the same as those of the bent type transmitter 1d of the second embodiment.
[0042]
As described above, the bent-type transmitter according to the present embodiment can easily set the secondary resonance frequency by changing the shape of the resonator element and the like.
Further, since the tip end of the vibrating reed is not supported or connected, the natural frequency is lower than that of the vibrating members 61a and 61b, and the second resonance frequency can be made closer to the first resonance frequency.
[0043]
The shape and structure of the vibrating member are not limited to the above-described vibrating members 62a and 62b. For example, as shown in FIG. The vibration members 63a and 63b (not shown) may be provided symmetrically.
The vibrating members 63a and 63b can vibrate the vibrating reed and the vibrating band in different directions. That is, the vibrating members have two vibration modes. The second natural vibration mode vibrates in the same direction. The second natural vibration mode is a mode in which each vibrating reed and the vibration band vibrate in different directions.
[0044]
Therefore, the bending type transmitter to which the vibrating members 63a and 63b are attached has the vibrating reed and the vibrating piece in the same direction as the disks 21a and 21b in a state where the disks 21a and 21b are vibrated in the primary bending vibration mode. A first resonance frequency at which the band vibrates, a second resonance frequency at which the disks 21a, 21b and the vibration band vibrate in the same direction and the vibrating piece vibrates in the opposite direction, and a second resonance frequency at which the vibrating reed vibrates in the opposite direction. The vibrating reed and the vibration band have the third resonance frequency at which the vibrating piece vibrates, and the low frequency region can have three frequency bands capable of transmitting.
[0045]
That is, the bent type transmitter according to the present embodiment provides a plurality of low-frequency plural frequencies by changing the shape, size and / or material of a plurality of vibrating members (for example, including a vibrating piece and a vibrating band). The band can be easily set.
The “material of the vibration member” specifically refers to a material characteristic related to a natural frequency such as density, rigidity, Poisson's ratio, and the like.
[0046]
Further, the bending type transmitter according to the present embodiment has a plurality of vibration members (for example, vibrating reeds and vibration bands) disposed in the same plane. In this frequency band, a sound wave having omnidirectionality in the horizontal direction can be transmitted.
Further, the vibrating reed and the vibrating band of the present embodiment are integrally formed as one vibrating member 62a, 63a. However, the annular portion provided with the recesses and the bolt holes is divided into a plurality of vibrating members (not shown). Of course).
[0047]
[Fourth embodiment]
10A and 10B are schematic diagrams for explaining a structure of a main part of a bent type transmitter according to the fourth embodiment, in which FIG. 10A is a plan view, and FIG. 10B is an enlarged cross section taken along line CC. FIG.
As shown in the drawing, in the present embodiment, in the above-described second embodiment, each disc-shaped vibrating body is further stacked with a set of voids and a vibrating member, and provided with two sets of voids and a vibrating member. .
[0048]
Specifically, as shown in the figure, the bent type transmitter 1e according to the present embodiment is configured such that a gap 52a, a vibration member 64a, a gap 53a, and a vibration member 65a are formed on a disk 22a toward the inner surface side. Similarly, a gap 52b, a vibrating member 64b, a gap 53b, and a vibrating member 65b are formed on the disk 22b toward the inner surface, and a flange is formed on the outer peripheral side of the disks 22a and 22b. Are projected in the circumferential direction, and the flanges are connected to each other by a cylinder 5e as a support member.
[0049]
The vibrating members 64a and 64b have a shape in which annular protrusions are protruded from the outer peripheral side at the periphery of the disks, and the protrusions are welded to the inner surfaces of the disks 22a and 22b. The height of the portion is the depth of the gaps 52a and 52b.
Further, the vibrating members 65a and 65b are similarly formed in such a manner that annular projections are protruded on the outer surface side at the peripheral edge of the disk, and the projections are welded to the inner surface side of the vibration members 64a and 64b. The height of the protrusion is the depth of the gaps 53a and 53b.
[0050]
The bent type transmitter 1e has a flange formed on the outer peripheral side of the disks 22a and 22b, and a bolt hole for inserting the bolt 71 is formed at a position equally divided in the circumferential direction of the flange. It is set up.
[0051]
The cylinder 5e is provided with a screw hole on each end face for fastening the bolt 71, and connects the disks 22a and 22b.
Here, it is preferable that the thickness of the cylinder 5e is reduced so that the function as a Helmholtz resonator can be exhibited. In this case, the flange and the cylinder 5e are fixed by the bolt 71, but the cylinder 5e is By deforming in the resonance state, the amplitude of the bending vibration of the disks 22a and 22b can be increased, and a high-output sound wave can be transmitted.
Other configurations and operations of the bent type transmitter 1e of the present embodiment are the same as those of the bent type transmitter 1d of the second embodiment.
[0052]
Next, the operation of the bent type transmitter 1e having the above configuration will be described with reference to the drawings.
FIG. 11 is a schematic cross-sectional view of a main part for describing a primary bending vibration mode at a first resonance frequency of the bending type transmitter according to the fourth embodiment.
FIG. 12 is a schematic cross-sectional view of a main part for describing a primary bending vibration mode at a second resonance frequency of the bending type transmitter according to the fourth embodiment. Further, FIG. 13 is a schematic cross-sectional view of a main part for describing a primary bending vibration mode at a third resonance frequency of the bending type transmitter according to the fourth embodiment.
[0053]
As shown in FIG. 11, when the bending type transmitter 1e applies a voltage signal having the same frequency as the first resonance frequency to the active vibrators 3a and 3b, the bent plates 1a and 3b (the active vibrators 3a and 3b, respectively). 3b) symmetrically resonates in the primary bending vibration mode, and emits a sound wave in the vertical direction of the bending type transmitter 1e.
At this time, the vibrating members 65a, 64a, 65b, 64b are the same as the disks 22a, 22b (including the active vibrators 3a, 3b, respectively), with the outer diameter positions of the gaps 52a, 52b, 53a, 53b as fulcrums. Bending vibration in the direction.
[0054]
Further, as shown in FIG. 12, when the bending type transmitter 1e applies a voltage signal having the same frequency as the second resonance frequency to the active vibrators 3a and 3b, the discs 22a and 22b (the active vibrators 3a and 3b, respectively) 3a and 3b) resonate symmetrically in the primary bending vibration mode and radiate sound waves in the vertical direction of the bending type transmitter 1e.
At this time, the vibrating members 64a and 64b are bent in the same direction as the disks 22a and 22b (including the active vibrators 3a and 3b, respectively) with the outer diameter position of the gaps 52a and 52b adjacent to the outer surface side as a fulcrum. The vibration members 65a and 65b vibrate in a direction opposite to the circular plates 22a and 22b (including the active vibrators 3a and 3b, respectively) with the outer diameter positions of the adjacent gaps 53a and 53b as fulcrums.
[0055]
As shown in FIG. 13, when a voltage signal having the same frequency as the third resonance frequency is applied to the active vibrators 3 a and 3 b, the bending type transmitter 1 e changes the circular plates 22 a and 22 b (the active vibrators respectively). 3a and 3b) resonate symmetrically in the primary bending vibration mode and radiate sound waves in the vertical direction of the bending type transmitter 1e.
At this time, the vibrating members 65a, 64a, 65b, 64b are opposed to the disks 22a, 22b (including the active vibrators 3a, 3b, respectively) with the outer diameter position of each of the gaps 52a, 52b, 53a, 53b as a fulcrum. Bending vibration in the direction.
[0056]
As described above, the bending-type transmitter 1e uses a disk as the vibration member, and by stacking a plurality of the disks, a plurality of resonance frequencies can be easily set.
The resonance frequency can be freely set by adjusting the shape and size of the vibration member and the gap.
[0057]
The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above embodiment, and can be variously modified within the scope of the present invention.
For example, although one piezoelectric ceramic is used as the active vibrator, the present invention is not limited to this configuration, and a configuration in which a plurality of piezoelectric ceramics are provided may be used.
When used at a large depth, a high-pressure fluid may be sealed in the gap between the disk-shaped vibrators, or a pressure regulator that regulates external pressure may be attached.
Furthermore, although a configuration using a plate-shaped vibration member is used, the invention is not limited to this. For example, a vibration member using a string may be used.
[0058]
【The invention's effect】
As described above, according to the bending type transmitter of the present invention, the bending vibration of the vibration member can be utilized, that is, the vibration member can be vibrated in the same phase or in the opposite phase to the disk. The active oscillator and the disk can resonate in the primary bending vibration mode at a frequency opposite to the frequency of the transmitted sound wave, and a sound wave having horizontal omnidirectionality is transmitted in a plurality of low frequency bands. can do.
[Brief description of the drawings]
FIG. 1 is a schematic diagram for explaining a structure of a main part of a bent type transmitter according to a first embodiment, where (a) is a plan view and (b) is AA. FIG. 4 shows a cross-sectional view along the line.
FIG. 2 is a sensitivity change graph for explaining a change in sensitivity with respect to frequency of a bent type transmitter according to a use example of the first embodiment of the present invention.
FIG. 3 is a schematic cross-sectional view of a main part for describing a primary bending vibration mode at a first resonance frequency of the bending type transmitter according to the first embodiment.
FIG. 4 is a schematic cross-sectional view of a main part for describing a primary bending vibration mode at a second resonance frequency of the bending type transmitter according to the first embodiment.
FIG. 5 is a schematic pattern diagram for explaining directivity at a resonance point P according to a usage example of the first embodiment of the present invention.
FIG. 6 is a schematic pattern diagram for explaining directivity at a resonance point Q according to a usage example of the first embodiment of the present invention.
FIGS. 7A and 7B are schematic diagrams for explaining a structure of a main part of the bent type transmitter according to the second embodiment, in which FIG. 7A is a plan view, and FIG. FIG. 4 shows a cross-sectional view along the line.
FIG. 8 is a schematic top view for explaining the structure of the vibration member of the bending type transmitter according to the third embodiment.
FIG. 9 is a schematic top view for explaining the structure of an application example of the vibration member of the bending type transmitter according to the third embodiment.
FIGS. 10A and 10B are schematic diagrams for explaining a structure of a main part of the bent type transmitter according to the fourth embodiment, where FIG. 10A is a plan view and FIG. FIG. 4 shows an enlarged sectional view taken along line.
FIG. 11 is a schematic cross-sectional view of a main part for describing a primary bending vibration mode at a first resonance frequency of the bending type transmitter according to the fourth embodiment.
FIG. 12 is a schematic cross-sectional view of a main part for describing a primary bending vibration mode at a second resonance frequency of the bending type transmitter according to the fourth embodiment.
FIG. 13 is a schematic cross-sectional view of a main part for describing a primary bending vibration mode at a third resonance frequency of the bending type transmitter according to the fourth embodiment.
14A and 14B are schematic diagrams for explaining a structure of a main part of a bent type transmitter according to a conventional example, in which FIG. 14A is a plan view, and FIG. FIG.
FIG. 15 is a schematic cross-sectional view of a main part for describing a primary bending vibration mode of a bending type transmitter according to a conventional example.
FIG. 16 is a schematic cross-sectional view of a main part for describing a tertiary bending vibration mode of a bending type transmitter according to a conventional example.
[Explanation of symbols]
1,1d, 1e Bend type transmitter
2a, 2b disk
21a, 21b disk
22a, 22b disk
3a, 3b Active vibrator
4a, 4b Disc-shaped vibrator
5 O-ring
5d sphere
5e cylinder
6a, 6b vibrating member
7 Spring band
51 gap
52a, 52b gap
53a, 53b gap
61a, 61b vibrating member
62a, 63a vibrating member
64a, 64b vibrating member
64a, 65b vibrating member
71,72 bolt
72 nut
10 outer sheath
101 Bend type transmitter
102a, 102b disk
103a, 103b Active vibrator
104a, 104b disk-shaped vibrator
105 O-ring
107 spring band
151 gap
171 volts
110 outer sheath

Claims (10)

A pair of disk-shaped vibrators composed of an active vibrating body that expands and contracts and a disk are disposed to face each other via a support member, and the pair of disk-shaped vibrators resonate symmetrically in a primary bending vibration mode. By doing, it is a bending type transmitter that transmits a pressure wave,
A bending type wave transmitter, comprising: a vibration member connected to the disk and vibrating in a vibration direction of the disk. The bending type transmitter according to claim 1, wherein the vibrating member has a disk shape, and a gap is provided between the vibrating member and the disk. 3. The bent type transmitter according to claim 2, wherein the gap is circular. The bent type transmitter according to any one of claims 1 to 3, wherein the vibrating member is formed integrally with the disk. The bending type transmitter according to any one of claims 1 to 3, wherein the vibration member is connected to the disk by welding, bonding, and / or a mechanical connection member. The bending type transmitter according to any one of claims 1 to 5, wherein a plurality of the vibration members are connected to the disk. 7. The bent type transmitter according to claim 6, wherein the plurality of vibrating members have different shapes, sizes and / or materials. 8. The bending type transmitter according to claim 6, wherein the plurality of vibration members are stacked and connected to the disk. 8. The bending type transmitter according to claim 6, wherein the plurality of vibration members are arranged in the same plane. 9. The bent type wave transmitter according to claim 8, wherein said support member has a cylindrical shape.

Images