JP3520837B2 - Bend type transducer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending type transducer which transmits / receives (transmits / receives) a sound wave in water, and more particularly, a plurality of slits provided in a cylindrical axial direction and a plurality of shafts formed between the slits. The present invention relates to a bending type transducer that flexibly vibrates by axial vibration of a cylindrical vibrator provided with a directional vibration plate inside a cylinder to transmit and receive sound waves in water.

[0002]

2. Description of the Related Art A conventional bending type transducer of this type is disclosed in, for example, Japanese Patent Laid-Open No. 3-11898 or Japanese Patent Laid-Open No. 2-30.
As shown in Japanese Patent Publication No. 9799, a plurality of axial vibration plates are provided around a cylindrical piezoelectric element (vibrator) and axially with both ends fixed to the ends of the piezoelectric element. The axial vibrator is substantially divided into a plurality of axial vibrators by inserting a plurality of slits in the axial direction of a cylindrical metal plate, and by the axial expansion and contraction (vibration) of the piezoelectric element. It is driven and vibrates in a bending vibration mode.
Since the resonance frequency of the axial oscillator is lowered by utilizing the bending vibration mode, the bending type transducer is used for the purpose of transmitting and receiving low frequency sound waves with a small and lightweight device.

FIG. 12 shows a bending type transducer according to the prior art similar to that disclosed in Japanese Patent Laid-Open No. 3-11898 or Japanese Patent Laid-Open No. 2-309799.
FIG. 4 is a perspective view showing a cross-section with four chips omitted. The axial vibration plate (axial vibration plate) 5 of this bending type transducer has a substantially cylindrical shape around the axial vibration plates (plurality) according to the disclosed technique, while the central part Has a hollow cylindrical shape. Although the shape of the diaphragm 5 has the effect of improving the water pressure resistance of the bending type transducer, the other configurations of the bending type transducer may be considered to be almost the same as those of the prior art.

In the bending type transducer shown in FIG. 12, two disk-shaped rings 3a and 3b each having a hole in the center (axis) are provided on both end faces of a plurality of laminated cylindrical vibrators 2, respectively. The cylindrical vibrator 2 is clamped and fixed with bolts 4 with the axis of the cylindrical vibrator 2 between 3a and 3b. The disk diameter of the rings 3a and 3b is
It is made larger than the maximum diameter of the cylindrical vibrator 2. The diaphragm 5, which is generally made of a metal plate, includes rings 3a and 3a.
It is arranged so as to surround the circumference of b, and both ends are fixed to the rings 3a and 3b by a plurality of fixing screws 90, respectively. Further, the diaphragm 5 constitutes a plurality of diaphragms by providing a plurality of slits 7 in the cylindrical axial direction. In addition, the outer periphery of the diaphragm 5 and the rings 3a and 3b
The outer edge portion of the flexible type transducer is covered with a rubber boot 6 made of rubber having elasticity, and the bending type transducer is watertightly protected.

The operation of the bending type transducer shown in FIG. 12 will now be described with reference to FIGS.

When an electric signal having the same frequency fr as the mechanical resonance frequency fr generated in each bending vibration mode of the diaphragm 5 is applied from the signal cable 8 to both ends of the laminated cylindrical vibrator 2, the cylindrical vibration occurs. The child 2 is driven to expand and contract in the axial direction at the frequency fr and vibrates. Then, the diaphragm 5 is vibrated and driven in the axial direction of the cylindrical vibrator 2 by the mechanical vibration of the cylindrical vibrator 2, and a bending vibration mode is generated in the diaphragm 5. That is, when the cylindrical vibrator 2 is expanded by applying an electric signal from the signal cable 8 (FIG. 13A).
In the vibrating plate 5, a concave portion projects outward in the cylinder (shown by a chain line) with the end of the ring 3a (and 3b) on the cylindrical vibrator 2 side as a fulcrum A of vibration. On the other hand, when the cylindrical oscillator 2 contracts, the diaphragm 5 has a recessed portion inward of the cylinder with respect to the fulcrum A (indicated by a solid line). That is, the vibration plate 5 vibrates in the bending vibration mode by applying the electric signal (see FIG. 13A).

The fulcrum of the bending type transducer is changed by the change of water pressure with the change of depth in the water. That is, when the water pressure becomes high, the fulcrum B becomes the ring 3a (and 3b).
To the fulcrum A, which is the end portion on the inner surface side, and moves toward the side where the resonance frequency fr of the diaphragm 5 is higher (see FIGS. 13A and 13B). This change in the fulcrum causes a problem of reducing the transmission efficiency at a desired transmission frequency.

Here, the frequency fr of mechanical vibration of the cylindrical vibrator 2 is set to be the same as the mechanical resonance frequency fr generated in the bending vibration mode of the diaphragm 5. Therefore, the diaphragm 5 causes mechanical resonance due to the bending vibration mode, and the bending type transducer of FIG. 12 can obtain a highly efficient acoustic output at a low frequency.
Mechanical resonance frequency f in bending vibration mode of diaphragm 5
r is the dimension of each diaphragm 5 and has a length L (cm),
Assuming that the thickness t (cm), the longitudinal elastic modulus E (kg / cm ² ), the density ρ (kg / cm ³ ), the Poisson's ratio σ, and the dimensionless coefficient determined by the vibration system are α, fr≈απt {E
It can be expressed as / 3 (1-σ ² ) ρ} ^1/2 / 2L ² .

[0009]

Although the bending type transducer according to the above-mentioned conventional technique is small and lightweight and can emit low frequency sound waves, the mechanical resonance frequency depending on the bending vibration mode of the vibrating plate to be constructed. There is a problem that the fr is determined to be one depending on the material and size of the diaphragm, and the band of the transducer is narrow.

Further, in this type of bending type transducer, since the supporting point of the bending vibration of the diaphragm that performs bending vibration changes due to the change in water pressure due to the change in depth in the water, the bending vibration mode of the diaphragm changes. There is a problem that the resonance frequency fr of the diaphragm changes and the transmission efficiency at the desired transmission frequency decreases.

Further, since the bending type transducer of this type relies on only the axial force of the cylindrical vibrator in which a plurality of laminated vibrating plates perform bending vibration, a large-sized low-frequency sound wave radiation is emitted. The transmission efficiency is inferior to that of the transducer that performs the above, and in order to radiate a large amplitude sound wave, a high voltage is required to drive the cylindrical vibrator, and the peripheral components such as the above output transformer and signal cable for driving are large. There was a problem that it turned into.

Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and is a bending type transmission / reception using a bending vibration mode of a diaphragm which is small and lightweight and which emits sound waves of low frequency with good transmission efficiency. In the wave resonator, the transmission ratio bandwidth, which is the frequency bandwidth that obtains a certain level of transmission level, is widened, and the transmission efficiency at the desired transmission frequency does not change the resonance frequency of the diaphragm due to changes in the depth of the water. An object of the present invention is to provide a bending type transducer which radiates sound waves well and further improves the transmission efficiency.

[0013]

A bending type transducer according to one aspect of the present invention holds a cylindrical oscillator that expands and contracts in the axial direction in response to an electric signal, and both ends of the cylindrical oscillator. A disk-shaped ring having a diameter larger than that of the cylindrical vibrator screwed by a nut provided on the head of the bolt and the tip of the disk at the center of the shaft, and the circumference and outer surface of the disk-shaped ring having two ends A bending type transmission / reception that radiates sound waves into the water by including a plurality of slits that respectively cover the sides and are provided in the axial direction of the cylinder and that are driven by bending vibration by axial expansion / contraction of the cylindrical vibrator. In the container, a disk-shaped end surface vibration plate connected to both ends of the axial direction vibration plate is provided so as to be spaced apart from the disk-shaped ring, the head of the bolt, and the nut.

A bending type transducer according to another aspect of the present invention comprises a cylindrical vibrator which receives an electric signal and expands and contracts in the axial direction, and a wire rod which holds both ends of the cylindrical vibrator. A disk-shaped ring having a diameter larger than that of the cylindrical vibrator to be lifted and fixed, and an end portion which covers the circumference and the outer surface side of each of the two disk-shaped rings, and a plurality of slits are provided in the axial direction of the cylinder. A bending type transducer that radiates sound waves in water, comprising a plurality of axial vibrating plates that are flexibly vibrated by axial expansion and contraction of a shaped vibrator, and a cylindrical vibrator that receives an electric signal and expands and contracts in the axial direction. A disk-shaped ring having a diameter larger than that of the cylindrical vibrator, which is tightened and fixed by wire rods so as to hold both ends of the cylindrical-shaped vibrator, and a circular circumference and an outer surface side of the disk-shaped ring having two ends A bending type transducer which radiates sound waves into water, comprising a plurality of slits which are respectively covered and are provided in an axial direction of a cylinder, and a plurality of axial vibration plates which are flexurally driven by axial expansion and contraction of the cylindrical vibrator. The end surface portion of the disk-shaped ring has a circular cross-sectional shape with respect to the axial direction, and both end portions of the axial diaphragm are
The disk-shaped ring is bent at the circular cross-section and extended toward the center of the shaft, and the extended tip is provided at the head of the bolt provided at the center of the shaft and the tip thereof. The feature is that each is held by a nut.

In the bending type transducer, the circular cross section of the disk-shaped ring, which is a contact portion with the end face vibration plate, is moved from the bending portion of the axial vibration plate toward the shaft center portion. Can be configured.

[0016] One of the bending type transducers according to the above-mentioned two inventions can have a constitution in which at least one of the widths of the plurality of axial diaphragms is different from the width of other axial diaphragms. .

In another one of the bending type transducers according to the above-mentioned two inventions, at least one of the plurality of axial diaphragms has a different thickness from the other axial diaphragms, but each has a different structure. Can be taken.

Still another one of the bending type transducers according to the above two inventions is such that at least one of the plurality of axial diaphragms has a concave minimum bending diameter and another axial diaphragm has a concave minimum bending diameter. It can have a configuration that is different from the diameter.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing one of the embodiments of the bending type transducer according to the present invention in a cross-section with one quarter not cut in the axial direction. FIG. 2 is a partial cross-sectional view for explaining the operation of the embodiment shown in FIG. 3 is a diagram showing a characteristic example in the embodiment of FIG.

Referring to FIG. 1, the bending type transducer according to the embodiment shown in FIG. 1 is composed of a plurality of laminated cylindrical vibrators 2 and rings used in the bending type transducer of FIG. Includes 3a and 3b and bolt 4. An electric signal of frequency fr is applied to the cylindrical vibrator 2 from both ends of the cylindrical vibrator 2 from the signal cable 8. Cylindrical oscillator 2
Also, both ends are sandwiched by the rings 3a and 3b, and are tightened (fastened) by the head of the bolt 4 and the nut 40.

The vibrating plate 5 which performs bending mode vibration in the axial direction of the cylindrical vibrator 2 (axial direction) is arranged so that its ends cover and contact the circumferential and outer surface directions of the rings 3a and 3b. The diaphragm 5 has a plurality of protrusions on the outer surface side of the rings 3a and 3b. The vibrating plate 5 is a plurality of vibrating plates 5 by dividing the circumference in the axial direction by a plurality of slits 7. The slit 7 is provided between the rings 3a and 3b.

On the upper and lower end surfaces (projections) of the diaphragm 5, disk-shaped end surface diaphragms 10 are fixed to the projections by screws 9, respectively. The end face vibration plate 10 is generally made of a thin metal plate, and the surface of the disk may be flat (planar), concave (concave to the cylindrical end face) or convex (convex) as required. In the end surface vibration plate 10, the central portions of the rings 3a and 3b are fixed by the bolts 4 and the nuts 40, and the peripheral portion thereof has the cylindrical vibrator 2.
Since it is driven to expand and contract in the axial direction, vibration of the bending vibration mode in which the amplitude of the peripheral portions of the rings 3a and 3b is large is performed. In order not to disturb the vibration of the end surface diaphragm 10,
The portion of the diaphragm 5 that covers the rings 3a and 3b, the head of the bolt 4, the nut 40, and the end surface diaphragm 10 are the end surface diaphragm 10
The distance is kept so that it does not come into contact with the vibration of.

Here, the mechanical resonance frequency Fr1 according to the bending vibration mode of the diaphragm 5 and the mechanical resonance frequency Fr2 according to the bending vibration mode of the end surface diaphragm 10 differ depending on the use of the above approximate expression or the experiment. Design to be. Further, a rubber boot 6 made of rubber is adhered to the periphery of the bending type transducer by an adhesive so as to cover the plurality of diaphragms 5 and the screws 9, and a portion for pulling out the signal cable 8 from the rubber boot 6 is provided. Is watertightly protected by being filled with resin.

Next, the operation of the bending type transducer according to the embodiment of FIG. 1 will be described with reference to FIGS. 1, 2 and 3.

When an alternating electric signal is supplied to the signal cable 8, the plurality of laminated cylindrical vibrators 2 are excited to generate mechanical vibration (expansion / contraction) in the axial direction of the cylinder. Rings 3 bonded to the upper and lower end surfaces of the cylindrical vibrator 2 and fastened by the heads of bolts 4 and nuts 40
The a and 3b move in corresponding axial directions according to the axial vibration of the cylindrical vibrator 2. That is, the rings 3a and 3b holding the cylindrical vibrator 2 push up the protrusion of the diaphragm 5 in the axial direction by the expansion of the cylindrical vibrator 2,
The bending vibration mode of the diaphragm 5 is generated by extending the diaphragm 5 in the axial direction of the cylindrical shape (see the solid line in FIG. 2). Then, sound waves (acoustic) are emitted in the outer surface direction of the diaphragm 5, that is, in the radial direction of the bending type transducer.

Further, when the diaphragm 5 extends in the axial direction of the cylindrical shape, the end surface diaphragm 10 has a radial direction (outer circumference) of the cylinder (disk) with the contact surface between the rings 3a and 3b and the diaphragm 5 as a fulcrum. It is compressed (see the solid line in FIG. 2). As a result, a bending vibration mode of the peripheral fixed disk is also generated in the end surface vibration plate 10. It should be noted that the amplitude of the acoustic radiation surface by the diaphragm 5 and the amplitude of the acoustic radiation surface by the vibration of the end surface diaphragm 10 are in opposite directions. Sound waves are radiated from the upper and lower end surfaces (outer surfaces) of the end surface vibration plate 10 in a bending vibration mode, and the radiated sound waves wrap around to the side of the cylindrical bending type transducer, that is, acoustic radiation generated by the end surface vibration plate 10. Is added to the acoustic radiation due to the vibration of the diaphragm 5, and the bending type transducer according to the embodiment of FIG. 1 can make the sound pressure in the radial direction higher than that of the diaphragm 5 alone.

Here, as described above, the diaphragm 5 and the end surface diaphragm 10 have a mechanical resonance frequency fr in the bending vibration mode.
, The mechanical resonance frequency Fr of the diaphragm 5
1, the mechanical resonance frequency Fr2 of the end surface diaphragm 10
When r1 <Fr2, a broadband transmission level curve on the high frequency side shown by the broken line in FIG. 3 is shown. When Fr1> Fr2, a transmission level curve having a wide band on the low frequency side indicated by the alternate long and short dash line is shown. As shown in FIG. 3, the bending type transducer according to the embodiment of FIG. 1 has a wider transmission ratio bandwidth than the transmission level curve of the conventional bending type transducer (see FIG. 12) shown by the solid line. You can get it. As described above, the bending type transducer according to the embodiment of FIG. 1 has a transmission level above a certain level due to the synergistic effect of the resonance frequency due to the mechanical resonance of the two diaphragms, the diaphragm 5 and the end surface diaphragm 10. This has the effect of widening the transmission ratio bandwidth, which is the frequency bandwidth that can be obtained.

FIG. 4 is a partial schematic view of a modification of the embodiment shown in FIG. FIG. 4 is a perspective view showing the vibration plate 5 by exfoliating the rubber boot 6 of the bending type transducer according to the embodiment of FIG. FIG. 5 is a diagram showing a characteristic example according to the modification of FIG.

In the embodiment of FIG. 1, the diaphragm 5 is formed so as to cover the circumference of each of the rings 3a and 3b and a part of the end face. Then, between the rings 3a and 3b, a plurality of slits 7 are provided in the diaphragm 5 surrounding the rings 3a and 3b in the axial direction of the cylinder to form the plurality of diaphragms 5. The respective widths W of the diaphragm 5 are equal widths, and as shown by the solid line in FIG.
r is the same.

However, in the modification of FIG. 4 (axial direction)
Regarding the width W of the diaphragm 5A, the width W of at least one diaphragm 5A is different from the width W of the other diaphragm 5A. In other words, the intervals between the slits 7 are not uniform. In the illustrated example, the width WA of the diaphragm 51 is the width WB of the diaphragm 52.
It is getting narrower. Therefore, the mechanical resonance frequency FrA due to the bending vibration mode of the diaphragm 51 becomes lower than the mechanical resonance frequency FrB according to the bending vibration mode of the diaphragm 52 because the rigidity, that is, the longitudinal elastic coefficient E decreases (see FIG. 5). . Therefore, the frequency band width of the transmitted sound wave of the bending type transducer according to the modification of FIG. 4 is a combination of the resonance characteristics of both as shown by the broken line in FIG. The transmission ratio bandwidth, which is the obtainable frequency bandwidth, can be widened. The width W of the diaphragm 5A
The number is not limited to two types, and may be variously selected according to required characteristics.

FIG. 6 is a schematic view of another part of the modification of the embodiment shown in FIG. 1, and shows a diaphragm 5B in which the part deformed from the diaphragm 5 of FIG. 1 is emphasized.

The minimum bending diameter R or thickness t of at least one concave shape of the plurality of (axial direction) diaphragms 5B in the modification of FIG. 6 is different from those of the other diaphragms 5B. That is, the minimum curved shape R or the thickness t of the concave shape of the plurality of diaphragms 5B is at least two types. The minimum radius R of the diaphragm 5B becomes smaller,
Alternatively, as the thickness t increases, the rigidity of the diaphragm 5B increases, that is, the longitudinal elastic modulus E increases, so that the mechanical resonance frequency Fr of the diaphragm 5B decreases. In the modification of FIG. 6 as well, since there are two or more types of mechanical resonance frequencies Fr depending on the bending vibration mode of the diaphragm 5B, the frequency bandwidth of the transmitted sound waves by the plurality of diaphragms 5 is the same as in the modification of FIG. Is shown in FIG.
As shown by the broken line in Fig. 4, it is a wide range that combines multiple resonance characteristics.

FIG. 7 is a perspective view showing another one of the embodiments of the bending type transducer according to the present invention in a cross section with about 1/4 not cut in the axial direction. FIG. 8 is a diagram showing one of the characteristic examples in the embodiment of FIG. FIG. 9 is a partial sectional view for explaining the operation of the embodiment of FIG. In addition, FIG.
FIG. 8 is a diagram showing another example of characteristics in the embodiment of FIG. 7.

Referring to FIG. 7, in this bending type transducer, the upper and lower end faces of a cylindrical vibrator 2 laminated and laminated are sandwiched by rings 30a and 30b having a circular cross section having a hole in the center, and the whole of them is sandwiched. It is fastened with a wire (wire material) 20 made of metal or FRP fiber. here,
Each of the rings 30a and 30b is the ring 3 shown in FIG.
Like a and 3b, it has a disk shape with a hole at the center of the shaft as a whole. However, each of the rings 30a and 30b has a circular cross-section at the contact surface with the diaphragm 5C that is divided up to the ends by a plurality of slits 7A that are replaced by the diaphragm 5. The plurality of diaphragms 5C include rings 30a and 3a.
It is lined up in contact with the circular cross section of the circular shape of 0b,
Both ends thereof are respectively bent in the axial direction in the vicinity of the contact surfaces and extend to the central portions of the upper and lower end surfaces on the outer surface side of the rings 30a and 30b. The two tips of the diaphragm 5C extending to the center of the upper and lower end surfaces on the outer surface side of the rings 30a and 30b are pressed from above and below by the heads or nuts 40 of the bolts 4 penetrating the holes of the shafts of the rings 30a and 30b. It is fixed.

The rings 30a and 30 of the diaphragm 5C are
The contact surface with b has a curvature shape that matches the circular cross-sections of the rings 30a and 30b. A signal cable 8 for supplying an electric signal for driving vibration to the cylindrical vibrator 2.
Is drawn from the head of the bolt 4, but may be drawn from the nut 40. The rubber boot 6A made of rubber has a plurality of slits 7 except the head of the bolt 4 and the nut 40.
And a plurality of diaphragms 5C are covered, and the covered portions are adhered by an adhesive. That is, the rubber boot 6A covers most of the bending type wave transmitter / receiver in the present embodiment. The lead-out portion of the signal cable 8 is filled with resin to be watertightly protected.

Next, referring to FIGS. 7, 8, 9 and 10, the operation of the bending type transducer according to the embodiment of FIG. 7 will be described.

The bending type transducer shown in FIG. 7 supplies an electric signal to the signal cable 8 to excite the cylindrical vibrator 2, and the excited cylindrical vibrator 2 has a circular cross section ring 30.
a and 30b are moved in the direction corresponding to the polarity of the electric signal. Here, the cylindrical oscillator 2 and the rings 30a and 30b
Are tightened up by the wire 20, and pre-stress the cylindrical vibrator 2. Rings 30a and 3
By the movement of 0b, the vibrating plate 5C in contact with the circular cross-section portions of the rings 30a and 30b is expanded in the axial direction of the cylindrical transducer 2, that is, the axial direction of the bending type transducer, and the circular shape A bending vibration mode is generated with the contact portion between the cross section and the diaphragm 5C as a fulcrum. Here, even if the water depth applied to the bending type transducer is changed by changing the underwater depth at which the bending type transducer is operated, the supporting point (fulcrum) of the diaphragm 5C in the bending vibration mode is that of the rings 30a and 30b. There is no change at only one contact surface between the circular cross section and the diaphragm 5. This is because the cross-sectional shape of the contact surfaces of the rings 30a and 30b with the diaphragm 5C is circular, and the contact surfaces of the diaphragm 5C with the rings 30a and 30b are also in conformity with the rings 30a and 30b. This is because the contact surfaces of the circular cross-section portions of the rings 30a and 30b and the diaphragm 5 do not change.

Accordingly, in the conventional bending type transducer, the mechanical resonance frequency fr changes while the fulcrum of the bending vibration mode of the diaphragm 5 changes with the change of water pressure due to the change of depth in the water. In the bending type transducer according to the embodiment, as shown by the broken line in FIG. 8, even if the water pressure (depth in the water) changes, the fulcrum of the diaphragm 5C does not change at one fulcrum, so the bending vibration mode of the diaphragm 5C is changed. Has an effect that the mechanical resonance frequency fr becomes constant regardless of the depth in water (see FIG. 8). This effect brings about an effect that the transmission level of the bending type transducer is stable regardless of the water depth.

Further, referring to FIG. 9, in the bending type transducer according to the embodiment of FIG. 7, the bolt 4 and the nut 40 at the central portion of the shaft are It does not move because it is mechanically independent of the cylindrical oscillator 2. Therefore, even when the cylindrical vibrator 2 expands or contracts, the end of the diaphragm 5C is held down by the bolt 4 and the nut 40, so that the end of the diaphragm 5C does not move and the contact surfaces of the rings 30a and 30b are not moved. Are pushed up to the bolt 4 and nut 40 sides. Since the amplitude of the acoustic radiation surface of the diaphragm 5C is efficiently performed by the action of the lever of the bolt 4 and the nut 40, this bending type transmitter / receiver responds to the supplied electric signal in comparison with the bending type transducer of the related art. An efficient transmission level can be obtained (see the broken line in FIG. 10).

FIG. 11 is a perspective view showing another one of the embodiments of the bending type transmitter / receiver according to the present invention, which is cut away in the axial direction by about 1/4 and is shown in a cross section.

The bending type transducer shown in FIG. 11 has a structure in which the rings 30a and 30b of the bending type transducer shown in FIG. 7 are replaced with rings 31a and 31b. Ring 31
a and 31b move the circular cross sections of the rings 30a and 30b from the axial center of the cylindrical vibrator 2. That is, the circular cross section is a protrusion of a substantially semicircular ring. Then, the bent portion of the diaphragm 5C in the axial direction becomes a contact point with the protrusion having the circular cross section of the rings 31a and 31b.

Similar to the bending type transducer shown in FIG. 7, this bending type transducer also receives the action of a lever with the position where the diaphragm 5C is fixed by the bolts 4 and the nuts 40 as a fulcrum. As shown by the broken line 10 in FIG. 10, an efficient transmission level for the supplied electric signal can be obtained.

The bending type wave transmitter / receiver described with reference to FIGS. 1 to 11 has been described only as a wave transmitter. However, since this bending type transducer is composed entirely of reversible elements, it receives the underwater sound wave with the vibrating plates 5 and 10 to generate vibration, and transmits this vibration to the cylindrical vibrator 2 to generate an electric signal. It is obvious that it can also be used as a receiver of underwater sound waves that generates the electric wave and takes out this electric signal from the signal cable 8.

[0045]

As described above, in the bending type transducer according to one aspect of the present invention, in addition to the plurality of cylindrical axial vibrating plates, end face vibrating plates are respectively provided on the upper and lower end faces of the axial vibrating plate. By providing the above, the resonance frequency of the bending vibration mode by the above-mentioned axial diaphragm and the resonance frequency of the bending vibration mode by the above-mentioned end face diaphragm are made different, and the transmission ratio band which is the frequency bandwidth for obtaining a transmission level above a certain level. The effect is that the width can be widened.

A bending type transducer according to another aspect of the present invention is a ring having a circular cross section for holding an end face of a cylindrical vibrator that expands and contracts when excited by an electric signal, and a cylindrical shaft of the axial diaphragm. By eliminating the change in the vibration fulcrum of the above-mentioned axial diaphragm by matching the contact surface with the part that bends in the direction, even if the water depth in which the bending type transducer operates changes and the water pressure changes, bending vibration It is possible to eliminate the change in the resonance frequency of the mode and maintain a high transmission efficiency at a desired transmission frequency.

An example of this bending type transducer is that the both ends of the axial vibration plate are extended to the center of the upper and lower end faces of the ring while being in contact with the ring, and the ends are vibrated by the cylindrical vibrator. Since it is fixed by a bolt and a nut that are independent of, there is an effect that the wave transmission efficiency of the axial diaphragm can be increased by the action of the lever by the bolt and the nut.

Further, in the two bending type transducers, at least one of the plurality of axial diaphragms has a width, a thickness and a minimum bending diameter different from those of the other axial diaphragms.
It is possible to widen the transmission ratio bandwidth by obtaining a plurality of resonance frequencies of the bending vibration mode by the axial diaphragm.

[Brief description of drawings]

FIG. 1 is a perspective view showing one of the embodiments of the bending type transducer according to the present invention in a cross section with one quarter not cut in the axial direction.

FIG. 2 is a partial cross-sectional view for explaining the operation of the embodiment of FIG.

FIG. 3 is a diagram showing a characteristic example in the embodiment of FIG.

FIG. 4 is a partial schematic view of a modification of the embodiment of FIG.

5 is a diagram showing a characteristic example according to a modification of FIG.

FIG. 6 is another partial schematic view of a modification of the embodiment of FIG.

FIG. 7 is a perspective view showing another one of the embodiments of the bending type transmitter / receiver according to the present invention in a cross section with about 1/4 not cut in the axial direction.

FIG. 8 is a diagram showing one of characteristic examples in the embodiment of FIG.

FIG. 9 is a partial cross-sectional view for explaining the operation of the embodiment of FIG.

FIG. 10 is a diagram showing another example of characteristics in the embodiment of FIG.

FIG. 11 is a perspective view showing another one of the embodiments of the bending type transducer according to the present invention in a cross section with about 1/4 not cut in the axial direction.

FIG. 12 is a perspective view showing a cross section of a bending type transducer according to the related art with about 1/4 not cut in the axial direction.

FIG. 13 is a partial cross-sectional view for explaining the operation of the bending type wave transceiver of FIG.

[Explanation of symbols]

2 Cylindrical vibrators 3a, 3b, 30a, 30b, 31a, 31b Ring 4 Bolt 5, 5A, 5B, 5C, 51, 52 Vibration plate 6, 6A Rubber boot 7, 7A Slit 8 Signal cable 9 Screw 10 End face vibration plate 20 Wires 30a, 30b Circular cross-section ring 40 Nut 90 Fixing screw

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04R 1/44 330 G01S 7/521 H04R 17/00 332

Claims (6)

(57) [Claims] 1. A cylindrical oscillator that expands and contracts in the axial direction in response to an electrical signal, and a nut provided at the center of the shaft and at the tip of the bolt so as to hold both ends of the cylindrical oscillator. A disk-shaped ring having a diameter larger than that of the cylindrical vibrator screwed together by means of an end, and a plurality of slits provided in the axial direction of the cylinder while the ends cover the circumference and the outer surface side of the two disk-shaped rings, respectively. In a bending type transducer that includes a plurality of axial vibration plates that are flexurally driven by axial expansion and contraction of a cylindrical vibrator to radiate sound waves in water, the disk-shaped ring, the head of the bolt, and the nut and the gap. A bending type transducer, characterized in that a disc-shaped end face vibration plate connected to both ends of the axial direction vibration plate is provided so as to open. 2. A cylindrical oscillator which receives an electric signal and expands and contracts in the axial direction, and a diameter larger than that of the cylindrical oscillator which is tightened and fixed by wire rods so as to hold both ends of the cylindrical oscillator. The disk-shaped ring and the ends thereof respectively cover the circumference and the outer surface side of the two disk-shaped rings, and a plurality of slits are provided in the axial direction of the cylinder, and the bending vibration is driven by the axial expansion and contraction of the cylindrical vibrator. In a bending type transducer including a plurality of axial vibration plates and radiating sound waves in water, an end surface portion of the disk-shaped ring has a circular cross-sectional shape with respect to the axial direction, and the axial vibration plates. Both ends of the bolt are bent at the circular cross section of the disk-shaped ring and extended toward the center of the shaft, and the extended tip end of the bolt is provided at the center of the shaft and its head. Installed at the tip Bending type transducer, characterized in that are holding respectively nuts. 3. The circular cross section of the disc-shaped ring, which is a contact portion with the axial vibration plate, is shifted from the bent portion of the axial vibration plate toward the axial center portion. The bending type transducer according to claim 2. 4. The bending type transducer according to claim 1, wherein at least one of widths of the plurality of axial diaphragms is different from widths of other axial diaphragms. . 5. The thickness of at least one of the plurality of axial diaphragms is different from the thickness of the other axial diaphragms, but is different from each other.
Bent type transducer described. 6. The minimum curved diameter of at least one concave shape of the plurality of axial vibration plates is different from the minimum curved diameter of concave shape of other axial vibration plates. The bending type transducer according to item 3.