JP7055024B2 - Sonic transmitter - Google Patents

Description

The present invention relates to a technique for transmitting sound waves in water or soil, and more particularly to a sound wave transmitter suitable for use under high water pressure and a shield machine provided therewith.

Generally, in water or soil, the deeper the depth, the higher the external pressure. Therefore, if the inside of the housing of this type of sound wave transmitter has a closed structure, an external pressure according to the depth acts on the diaphragm of the sound wave transmitter on the outside of the diaphragm. Therefore, in order to generate sound waves, it is necessary to push the diaphragm from the inside to the outside with a force exceeding the external pressure, so that there is a problem that a large output corresponding to the depth is required.

Here, as a sound wave transmitter having a large generated stress corresponding to a large depth, Patent Document 1 uses a magnetostrictive element that vibrates due to magnetostriction to obtain a large output according to the depth. The technology corresponding to the depth is disclosed. Further, Patent Document 2 discloses a technique of canceling a pressure difference acting on both sides of a diaphragm by providing an opening in a housing of a sound wave transmitter so that external water can freely enter and exit the housing. .. According to the technique described in Patent Document 2, sound waves can be transmitted even under a large depth with a large external pressure.

Japanese Unexamined Patent Publication No. 2010-141540 Japanese Unexamined Patent Publication No. 2010-182804

However, if the structure is such that the housing is simply sealed due to concern about the infiltration of impurities into the housing as in the technique described in Patent Document 1, the vibration of the diaphragm is caused by the pressure difference between the inside and outside of the housing. There is a problem that it is hindered or the element inside the sound wave transmitter is damaged.
On the other hand, as in the technique described in Patent Document 2, a structure in which an opening is provided in the housing to allow external water to freely enter and exit the housing is a housing in a situation where there are many impurities such as sand and stones in the soil. The infiltration of impurities into the interior may cause damage to the elements inside the sound wave transmitter.
Therefore, the present invention has been made by paying attention to such a problem, and has highly reliable operability and pressure resistance even when used under a large depth, and can be miniaturized. It is an object of the present invention to provide a suitable sound wave transmitter and a shield machine equipped with the same.

In order to solve the above problems, the sound wave transmitter according to one aspect of the present invention has a vibrating plate and a gap portion inside itself defined by a peripheral wall including the vibrating plate while supporting the vibrating plate violently. A watertight housing filled with liquid, an oscillator provided inside the housing to vibrate the vibrating plate, and a state attached to the housing to prevent liquid from entering the inside of the housing. A sound wave transmitter including a pressure balancing means for balancing the hydraulic pressure inside the housing with the hydraulic pressure outside the housing, wherein the pressure balancing means is a cylinder attached to the housing and the cylinder. It is characterized by having a piston that is fitted and slides and moves according to a pressure difference between the inside and outside so as to balance the pressure outside the housing with the pressure inside the housing .

According to the sound wave transmitter according to one aspect of the present invention, a watertight housing in which the void portion inside itself is filled with a liquid is provided, and the pressure inside and outside the housing is applied by the pressure balancing means attached to the housing. By balancing, it is possible to cancel the pressure difference between the inside and outside of the housing acting on the diaphragm and reduce the action of the external pressure on the element inside the oscillator. Therefore, it is not necessary to make the element a withstand voltage specification. As a result, even when used under a large depth, it is possible to suppress the increase in size and cost of the device and generate sound waves under high water pressure by a compact sound wave transmitter.

Then, this pressure balancing means balances the hydraulic pressure inside the housing with the hydraulic pressure outside the housing while preventing the liquid outside the housing from entering the inside of the housing, so that the liquid casing outside the housing Invasion into the body is prevented. Therefore, even in a situation where there are many impurities such as sand and stones in the soil, the infiltration of impurities into the housing can be prevented. Therefore, it has highly reliable operability and pressure resistance even when used under a large depth.
Further, according to the shield machine according to one aspect of the present invention, since the sound wave transmitter according to one aspect of the present invention is provided, the equipped sound wave transmitter is small even when used under a large depth. It is suitable for use and exhibits highly reliable operability and pressure resistance under a large depth.

Here, in the sound wave transmitter according to one aspect of the present invention, the pressure balancing means includes a cylinder attached to the housing, a hydraulic pressure outside the housing and a liquid inside the housing fitted in the cylinder. It is preferable to have a piston that slides and moves according to the pressure difference between the inside and the outside so as to balance the pressure.
It is preferable that the pressure balancing means further includes an elastic member that prevents the piston from vibrating due to the vibration of the diaphragm. It is preferable that the pressure balancing means further has a damper means for preventing the pressure balancing means itself from vibrating when the diaphragm vibrates. Such a configuration is suitable for preventing the vibration of the pressure balancing means itself due to the vibration of the diaphragm.

As described above, according to the present invention, even when used at a large depth, the pressure inside the housing of the sound wave transmitter and the pressure with the outside while preventing impurities from entering the inside of the housing. It is possible to transmit sound waves with a relatively small generated stress while preventing buckling of elements inside the oscillator such as a super-magnetostrictive element. Therefore, it is possible to provide a sound wave transmitter suitable for miniaturization while having highly reliable operability and pressure resistance under a large depth, and a shield machine provided with the sound wave transmitter.

It is explanatory drawing of one Embodiment of the sound wave transmitter which concerns on one aspect of this invention, FIG. It is an enlarged view of the main part of the part of the pressure balance plug attached to the sound wave transmitter of FIG. It is a schematic explanatory diagram of the tunnel excavation method by the shield machine equipped with the sound wave transmitter of FIG. It is a schematic diagram ((a)-(c)) explaining the operation of the pressure balance plug attached to the sound wave transmitter of FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings as appropriate. The sound wave transmitter of the present embodiment has water pressure resistance under a large depth and is suitable for miniaturization.
The drawings are schematic. Therefore, it should be noted that the relationship, ratio, etc. between the thickness and the plane dimension are different from the actual ones, and there are parts where the relationship and ratio of the dimensions are different between the drawings. Further, the embodiments or modifications shown below exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention describes the materials, shapes, and shapes of constituent parts. The structure, arrangement, etc. are not specified in the following embodiments.

As shown in FIG. 1, the sound wave transmitter 10 includes a watertight housing 1 having a sealed structure and an oscillator 3 provided in the housing 1 to vibrate the diaphragm 2. The housing 1 has a disk-shaped bottom surface portion 1a and a cylindrical portion 1b constituting a cylindrical side surface. In this example, a disk-shaped diaphragm 2 is coaxially mounted on the opening side facing the bottom surface portion 1a of the housing 1.
The bottom surface portion 1a and the cylindrical portion 1b are in-row fitted to each other, and water is stopped between the outer peripheral surface of the bottom surface portion 1a and the inner peripheral surface of the cylindrical portion 1b by a sealing member using an O-ring 34. The infiltration of liquids and impurities from the outside into the inside is prevented. The diaphragm 2 is softly supported on the front side of the cylindrical portion 1b (on the right side in the figure (a)) so as to be vibrable, and a gap portion E is formed inside itself defined by a peripheral wall including the diaphragm 2. There is.

A support pipe 4 is coaxially mounted on the outer surface of the bottom surface portion 1a via an annular support flange 5. The support flange 5 is fixed to the outer surface of the bottom surface portion 1a with a plurality of fixing bolts 32. Water is stopped between the mounting surface of the support flange 5 and the outer surface of the bottom surface portion 1a by a sealing member using an O-ring 35 to prevent liquids and impurities from entering the inside. In this example, the connection portion between the support pipe 4 and the support flange 5 is covered with a cover 36 made of MC nylon so as to cover the periphery thereof.

The oscillator 3 is a magnetostrictive actuator that vibrates due to magnetostriction in order to oscillate a sound wave by the diaphragm 2. It is composed of a coil and a countersunk spring. Since the coil is formed of an enamel wire or the like, if the connection portion between the coil and the cable 8 is waterproof, the oscillator 3 operates normally without a short circuit even when it is placed in water.

In the oscillator 3 of the present embodiment, the housing 1 is provided so that the displacement direction of the magnetostrictive element coincides with the facing direction between the opening portion of the housing 1 (that is, the portion where the diaphragm 2 is mounted) and the bottom surface portion 1a. It is housed coaxially with the center of the inside of. The base end surface of the oscillator 3 is fixed to the bottom surface portion 1a by a plurality of fixing bolts 31, and is arranged coaxially with the center of the disk-shaped diaphragm 2.
The bottom surface portion 1a of the housing 1 is formed with a drawing hole for drawing out the two cables 8 led out from the oscillator 3 from the inside of the housing 1 to the outside, and the housing 1 is underwater or the like in other parts. When placed in the liquid of, the liquid such as water outside the housing 1 is prevented from entering the inside of the housing 1.

The two cables 8 are connected to both ends of the coil constituting the oscillator 3 and are led out to the outside of the housing 1 via the bottom surface portion 1a. A power supply is connected to the cable 8, and when power is supplied to the cable 8 from the power supply, the giant magnetostrictive actuator of the oscillator 3 vibrates, and the diaphragm 2 vibrates due to the vibration to emit low-frequency sound waves. It has become.

In the present embodiment, a female screw is formed in the center of the back surface of the diaphragm 2, a male screw is formed at the tip of the output end of the oscillator 3, and the output end of the oscillator 3 is screwed into the female screw on the back surface of the diaphragm 2. It is fixed by the fixing nut 33.
The number of giant magnetostrictive actuators constituting the oscillator 3 is not limited to one. For example, a plurality of magnetostrictive actuators are housed in the housing 1 so that the displacement direction of the supermagnetostrictive element coincides with the facing direction between the opening of the housing 1 and the bottom surface portion 1a, and the output end of each supermagnetostrictive actuator is set. It may be configured such that it is connected to the diaphragm 2 and the base end is supported by the bottom surface portion 1a.

The diaphragm 2 is a plate that vibrates with the vibration of the oscillator 3 and emits low-frequency sound waves. In this embodiment, two packings 6 are formed in an annular shape on the peripheral edge of the diaphragm 2. It is arranged in the opening of the housing 1 in a state where the support portion of the above is sandwiched from both sides in the axial direction. The shape of the diaphragm 2 is a disk shape smaller than the opening of the housing 1.
The packing 6 of the present embodiment is a cushion rubber formed in an annular shape coaxially, and the first packing 6a on the inner side in the axial direction has a diameter equivalent to the inner and outer diameters of the side end portion 1d of the housing 1. The second packing 6b on the outer side in the axial direction has a diameter equivalent to the outer diameter of the side end portion 1d of the housing 1.

The two packings 6 are softly connected by being sandwiched between the side end portion 2b of the housing 1 and the cap-shaped diaphragm holding nut 7 so as to overlap the annular support portion provided on the diaphragm 2. Has been done. The packing 6 fills the space between the diaphragm 2 and the side surface portion 1b, and the gap portion E inside the housing 1 is sealed. The gap E is filled with a liquid such as water between the inside of the housing and the oscillator 3.
The packing 6 may be replaced with a packing other than rubber as long as it has flexibility. When the clearance between the diaphragm 2 and the side end portion 2b of the housing 1 is appropriately provided, when the sound wave transmitter 10 is placed in the liquid, the packing 6 is deformed by the hydraulic pressure outside the sound wave transmitter 10 and the packing 6 is deformed. Damage can be prevented. The clearance is appropriately changed depending on conditions such as the material and thickness of the packing 6 and the external hydraulic pressure of the sound wave transmitter 10.

In the housing 1 of the present embodiment, two water injection / drainage bolts 26 are interposed at positions separated from the cylindrical portion 1b by 180 degrees in the circumferential direction at positions in contact with the inner surface of the bottom surface portion 1a. It is attached so that it can be attached and detached. As a result, when the gap portion E is filled with the liquid, first, the upper and lower water injection / drainage bolts 26 are removed, and the diaphragm 2 is directed downward and the bottom surface portion 1a is oriented upward. Then, water is injected from the mounting hole of one water injection / drainage bolt 26, and exhaust gas is discharged from the mounting hole of the other water injection / drainage bolt 26.

Next, when the injection liquid is discharged from the mounting hole of the other pouring / draining bolt 26, the other pouring / draining bolt 26 is mounted in the mounting hole, and in that state, until it overflows from the mounting hole of one pouring / draining bolt 26. Continue water injection. After that, when the liquid injection overflows from the mounting hole of one of the water injection / drainage bolts 26, it is determined that the space between the inside of the housing and the oscillator 3 is filled with the liquid, and by mounting the one water injection / drainage bolt 26, the gap portion is formed. E can be filled with a liquid.
As a result, in the sound transmitter 10, the oscillator 3 supports the diaphragm 2 from the inner surface side, and the flexible packing 6 is connected to the diaphragm 2 and the side end portion 2b. Therefore, the diaphragm 2 is not constrained by the housing 1, and the diaphragm 2 and the housing 1 are relatively displaced from each other, so that the diaphragm 2 can vibrate even at a deep water pressure.

Here, the sound wave transmitter 10 is attached to the housing 1 to prevent the liquid outside the housing from entering the inside of the housing, and the hydraulic pressure outside the housing 1 and the liquid inside the housing 1 are prevented. It is equipped with a pressure balancing plug 20 which is a pressure balancing means for balancing pressure.
A mounting portion 2c of the pressure balancing plug 20 is formed through the side surface of the cylindrical portion 1b of the housing 1 along the radial direction. A female screw is formed on the inner peripheral surface of the mounting portion 2c. The pressure balancing plug 20 has a hollow cylindrical cylinder 21, and a male screw formed on the outer peripheral surface of the cylinder 21 is screwed into a female screw of the mounting portion 2c. Water is stopped between the pressure balancing plug 20 and the mounting portion 1c of the housing 1 by a sealing member (not shown) using, for example, a liquid packing material to prevent liquids and impurities from entering the inside. ing.

Specifically, the pressure balancing plug 20 has a hollow cylindrical cylinder 21 attached to the housing 1 and a solid cylindrical piston 22 fitted in the cylinder 21. An annular engaging portion 21t is formed in the lower part of the cylinder 21 (on the side of the gap E) so as to project inward in the radial direction, and the inner diameter portion of the engaging portion 21t is the pressure inside the gap E. It is a receiving part of.
The inner diameter of the engaging portion 21t is smaller than the outer diameter of the piston 22, and the internal piston 22 prevents the piston 22 from moving below the upper surface of the engaging portion 21t. Further, a concave annular groove is formed substantially in the center of the outer peripheral surface of the piston 22, and the O-ring 25 mounted on the concave annular groove stops water from being between the inner peripheral surface of the cylinder 21 and the outside. The ingress of liquids and impurities from the inside is prevented.

A female screw is formed on the inner peripheral surface of the upper portion of the cylinder 21, and an annular cap 23 having a male screw formed on the outer peripheral surface is attached to the female screw from the upper side of the cylinder 21. The through hole 23h in the center of the annular cap 23 serves as an introduction port for introducing an external liquid, and the external hydraulic pressure introduced from the through hole 23h causes the upper surface 22m of the piston 22 to move downward in the axial direction ( It is configured to press toward the gap E side).
As a result, when the upper surface 22 m of the piston 22 is pressed, the pressure balancing plug 20 balances the hydraulic pressure inside the housing with the hydraulic pressure outside the housing (in other words, with the hydraulic pressure outside the housing). The piston 22 slides along the axial direction according to the pressure difference between the inside and the outside (so that the hydraulic pressure inside the housing is the same).

Further, the pressure balancing plug 20 of the present embodiment has a vibration preventing means for preventing the vibration of the pressure balancing means itself due to the vibration of the diaphragm. The vibration preventing means of the present embodiment is an elastic member 24 made of porous rubber formed in a solid cylindrical shape. The elastic member 24 has an outer diameter formed to be the same as that of the piston 22, and is fitted so as to fill the gap E side in the cylinder 21 so as to face the sliding movement direction of the piston 22.
That is, the pressure balancing plug 20 has a double structure in which a piston 22 that slides and moves and an elastic member 24 that prevents vibration of the piston 22 are coaxially arranged side by side. The lower surface of the elastic member 24 abuts on the upper surface of the engaging portion 21t at the lower portion of the cylinder 21, thereby restraining the movement of the elastic member 24 below the upper surface of the engaging portion 21t.

Next, an example of tunnel excavation by a shield machine equipped with the sound wave transmitter 10 will be described. As shown in FIG. 3, the sound wave transmitter 10 is an example used for position detection during underground construction. In the figure, in urban area C, underground construction is performed by a shield machine 40 in a deep underground UG. Shows the image of the building.
Here, in the construction of underground structures such as tunnel construction and boring construction, the construction will proceed along the alignment of the plan after accurately grasping the current position in the ground. As a method of accurately detecting the current position (measurement point) in the ground, sound waves are transmitted from a sound wave transmitter 10 provided in an excavator such as a shield machine to three or more receiving points whose coordinates are known. Then, the position of the excavator is calculated by measuring the propagation time to each receiving point.

That is, as shown in the figure, in the shield machine (digger) 40, an insertion device 50 equipped with a sound wave transmitter 10 is arranged at an appropriate position of the bulkhead 41, and a push-pull included in the insertion device 50 is provided. The sound wave transmitter 10 can be moved to the transmitting position and the retracting position by the front-back operation in the axial direction by the means. As for the insertion device 50, a well-known technique (see, for example, Japanese Patent Application Laid-Open No. 2010-59676) can be adopted, and detailed description thereof will be omitted.

In the present embodiment, as shown in the figure, the oscillator 10 is arranged on the face side from the inside of the shield machine 40, and the underground position of the shield machine 40 is detected. In this embodiment, an example of using the shield machine 40 is shown, but for example, it may be used for a TBM (tunnel boring machine), a propulsion machine, or the like, and the excavator applied to the sound wave transmitter of the present invention is a shield machine. Not limited to.
The shield machine 40 has a cutter head 41 for excavating and a shield portion 42 located behind the cutter head 41 to protect various equipment inside the shield machine 40. The front portion of the shield portion 42 is partitioned by the bulkhead 43, and a chamber 45 in which the earth and sand excavated by the cutter head 41 is temporarily deposited is formed between the cutter head 41 and the bulkhead 43.

An opening 44 is formed in the bulkhead 43, and the insertion device 50 allows the sound wave transmitter 10 to be inserted into the face side from inside the shield portion 42. Here, the sound wave transmitter 10 installed on the outside of the shield machine 40 is vulnerable to vibration and impact, and may be damaged or damaged. In this embodiment, the insertion device 50 is fixed to the bulkhead 43. At the time of detecting the underground position, the sound wave transmitter 10 is inserted from the opening 44 to the face side and collected after the measurement, so that the failure or damage of the sound wave transmitter 10 is prevented.

In urban area C, a receiving unit is installed at a predetermined position. In the example of the figure, the vertical holes 65 and 75 are drilled from the ground at a position separated from the ground by, for example, about 25 to 100 m in front of the underground construction position by the shield machine 40. Then, in these vertical holes 65, 75, the first receiving unit 60 hangs a cable 64 to which the three receivers 61, 62, 63 are mounted, and the second receiving unit 70 hangs the three receivers 71, 72. , 73 stands by in a state where the cable 74 to which the cable 74 is attached is hung down.

When detecting the underground position of the shield machine 40, first, the excavation by the shield machine 40 is stopped so that the slit or opening (not shown) formed in the cutter head 41 corresponds to the position of the opening 44 of the bulkhead 43. Adjust the position of the cutter head 41. Next, the pressure in the pipeline and the pressure difference on the face side are made equal by operating the pressure adjusting valve provided in the insertion device 50. Then, the sound wave transmitter 10 is arranged on the face side by pushing the insertion tube toward the face side by the pushing and pulling means.

After the sound wave transmitter 10 is arranged at a predetermined position, the sound wave transmitter 10 is operated to carry out the measurement work by the sound wave transmitter 10. Since the first receiving unit 60 and the second receiving unit 70 have known coordinates of the three receivers 61, 62, 63 and the three receivers 71, 72, 73, the coordinates of the three receivers 61, 72, 73 are known for these three receiving points. The position of the shield machine 40 can be calculated by transmitting the sound wave S from the sound wave transmitter 10 provided in the shield machine 40 and measuring the propagation time to each receiving point.
After the measurement, the sound wave transmitter 10 is pulled into the bulkhead 43 by operating the pushing / pulling means, the gate is closed, and the drain valve provided in the insertion device 50 is opened to discharge water and earth and sand in the pipeline. Since the sound wave transmitter 10 is protected by the protective case provided in the insertion device 50, it is possible to prevent the sound wave transmitter 10 from being damaged when it is inserted into the excavated earth and sand.

Next, the operation and effect of the above-mentioned sound wave transmitter 10 will be described.
As described above, the sound wave transmitter 10 of the present embodiment includes a watertight housing 1, an oscillator 3 supported by the bottom surface portion 1a of the housing 1, and a diaphragm 2 supported by the tip of the oscillator 3. Since the packing 6 is a flexible connecting portion that flexibly connects between the housing 1 and the diaphragm 2, sound waves can be efficiently transmitted in water and soil.

In particular, in the sound wave transmitter 10 of the present embodiment, the void portion E in the watertightly defined housing 1 is filled with a liquid, and in the oscillator 3, the giant magnetostrictive actuator has a giant magnetostrictive element having a large driving force. Therefore, the diaphragm 2 of the sound wave transmitter 10 can transmit sound waves even at a deep water pressure.
That is, since the magnetostrictive element constituting the oscillator 3 is driven by the electromagnetic coil, it can transmit low frequency sound waves. The giant magnetostrictive actuator of the oscillator 3 can be operated by a normal amplifier, and does not require a special high voltage output device such as a ceramic type. Further, the giant magnetostrictive element constituting the oscillator 3 has a large driving force, and the actuator size to be accommodated inside the housing 1 can be selected according to the size of the housing 1 such as the diameter of the cylindrical portion 1b. Moreover, since the structure is simple, the device can be miniaturized.

Therefore, the sound wave transmitter 10 of the present embodiment has a highly reliable pressure resistance under a large depth, and can withstand a large depth of water pressure to transmit a desired sound wave. Further, since the driving force of the magnetostrictive element is large, the sound wave transmitter 10 can be miniaturized. The underwater sound wave transmitter 10 is theoretically 1 because the air chamber portion does not exist because the void portion E inside itself defined by the peripheral wall including the diaphragm 2 is filled with the liquid. It can operate normally even at a water depth of 10,000 m or more.

Further, as shown in FIG. 4, the underwater sound wave transmitter 10 of the present embodiment is attached to the housing 1 in a state where liquid such as water outside the housing 1 is prevented from entering the housing 1. Since the pressure balancing plug 20 for balancing the hydraulic pressure inside the housing 1 with the hydraulic pressure outside the body 1, the vibrating plate 2 is under water pressure at a deep depth as shown in FIGS. Even if there is, sound waves can be transmitted in a stable state.
That is, as shown in FIG. 3A, the pressure balancing plug 20 is made of porous rubber because the force with which the upper surface 22m of the piston 22 is pressed is weak when the hydraulic pressure outside the housing 1 is low. The elastic member 24 is in the extended state, and the sliding position of the piston 22 in the cylinder 21 is also maintained at the low pressure equilibrium position closer to the outside of the housing 1 in response to the low pressure inside and outside.

On the other hand, as shown in FIG. 3B, when the hydraulic pressure outside the housing 1 is high under a large depth of water pressure, the hydraulic pressure outside the housing 1 causes the upper surface 22m of the piston 22 to rise. When pressed, the hydraulic pressure inside the housing should be balanced with the hydraulic pressure outside the housing (in other words, the hydraulic pressure outside the housing should be the same as the hydraulic pressure inside the housing). The piston 22 slides toward the inside of the gap E along the axial direction according to the pressure difference between the inside and the outside, and is held at the high pressure equilibrium position near the inside of the housing 1 in response to the high pressure.

As a result, by balancing the pressure inside and outside the housing 1, the pressure difference between the inside and outside of the housing 1 acting on the diaphragm 2 can be canceled, and the action of the external pressure on the element inside the oscillator 3 can be reduced. Therefore, it is not necessary to make the element a withstand voltage specification. Therefore, even when the sound wave transmitter 10 is used under a large depth, it is possible to generate sound waves under high water pressure due to a compact configuration while suppressing an increase in size and cost of the device. In particular, the operation of the piston 22 sliding and moving in the gap E along the axial direction is performed in a state where the liquid outside the housing is prevented from entering the inside of the housing, so that sand, stones, etc. in the soil are prevented from entering the housing. Even in a situation where there are many impurities, it is possible to reliably prevent the infiltration of liquids and impurities from the outside into the inside.

Here, when the sound wave transmitter 10 of the present embodiment transmits a sound wave in a state where the pressure inside and outside the sound wave transmitter 10 is balanced by the pressure balancing plug 20, the oscillator 3 is as shown in FIG. 4 (c). The magnetostrictive actuator is energized, the giant magnetostrictive element expands, and the magnetostrictive element pushes the diaphragm 2 outward to generate a pressure wave.
At this time, as shown in the figure, the volume of the void portion E inside the housing 1 increases by the amount of extension of the magnetostrictive element. Although the pressure inside the housing 1 is equal to the external pressure due to the pressure adjusting action of the pressure balancing plug 20 described above, a negative pressure is applied to the inside of the housing 1 as the volume of the gap E increases. Therefore, as shown in the figure, the pressure balancing plug 20 further slides so that the piston 22 inside the cylinder 21 is pulled into the gap E side of the housing 1 so as to balance the pressure inside and outside the housing. do.

By this slide movement, in addition to the sound wave emitted from the diaphragm 2, the sound wave transmitter 10 generates a sound wave having a phase opposite to the sound wave emitted from the diaphragm 2 from the pressure balancing plug 20. Therefore, there is a concern that the sound waves having the opposite phase attenuate the sound waves emitted from the diaphragm 2.
Therefore, in the present embodiment, as a vibration preventing means for preventing the vibration of the piston 22 inside the pressure balancing plug 20 when the diaphragm 2 vibrates, a double structure in which an elastic member 24 made of porous rubber is installed inside the cylinder 21. Therefore, the vibration of the pressure balancing means itself at the time of vibration of the diaphragm 2 is prevented, and the generation of sound waves having opposite phases from the pressure balancing plug 20 is prevented. It is preferable that the natural frequency of the pressure balancing means is provided so as to deviate from the frequency transmitted by the diaphragm 2. Also in the present embodiment, the natural frequency of the piston 22 of the pressure balancing plug 20 is set. It is provided so as to deviate from the frequency transmitted by the diaphragm 2.

As described above, the sound wave transmitter 10 has highly reliable operability and pressure resistance under a large depth, and is suitable for miniaturization. The sound wave transmitter according to the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention.
For example, in the above embodiment, the packing 6 is an example of the connection portion of the sound wave transmitter according to the present invention, and two packings 6 may not be prepared. For example, one packing 6 and two diaphragms 2 may be overlapped with each other, and the outer periphery of the packing 6 may be softly connected to the cylindrical portion 1b of the housing 1.

In short, the flexible packing 6 may softly connect the diaphragm 2 and the cylindrical portion 1b to each other. The connecting portion by the packing 6 or the like has flexibility such as rubber that fills the space between the diaphragm 2 and the cylindrical portion 1b, and if the diaphragm 2 and the cylindrical portion 1 are softly connected to each other, the connecting portion is provided. The inside and the outside of the upper part of the housing 1 are blocked, and the diaphragm 2 can vibrate without being restricted by the housing 1.

1 Housing 1a Bottom part 1b Cylindrical part 1c Mounting part 1d (Opening side) side end part 2 Diaphragm 3 Oscillator (super-magnetostrictive actuator)
4 Support pipe 5 Support flange 6 Packing 6a First packing 6b Second packing 7 Diaphragm holding nut 8 Cable 9 O-ring 10 Sonic transmitter 20 Pressure balancing plug (pressure balancing means)
21 Cylinder 22 Piston 23 Cap 24 Elastic member (porous rubber)
25 O-ring 26 Note drain bolt 31 Fixing bolt 32 Fixing bolt 33 Fixing nut 34 O-ring 35 O-ring 36 Cover 40 Shielding machine 41 Bulkhead 50 Inserting device 60 1st receiving unit 70 2nd receiving unit E Air gap

Claims (1)

Diaphragm and
A watertight housing that vibratesably supports the diaphragm and fills the voids inside itself with a liquid, which is defined by a peripheral wall containing the diaphragm.
An oscillator provided in the housing and vibrating the diaphragm,
A sound wave transmitter provided with a pressure balancing means attached to the housing to balance the liquid pressure inside the housing with the liquid pressure outside the housing in a state where the liquid outside the housing is prevented from entering the inside of the housing. And,
The pressure balancing means slides according to the pressure difference between the inside and the outside so as to balance the cylinder attached to the housing and the hydraulic pressure outside the housing and the hydraulic pressure inside the housing fitted in the cylinder. A sonic transmitter characterized by having a moving piston .

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