JP2009147872A - Underwater sound source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an underwater sound source device that prevents gas from entering a hydraulic system. <P>SOLUTION: The underwater sound source device includes an internal atmospheric control means 8 of balancing internal atmospheric pressure with external water pressure, an oil pressure balancing device 10 which balances the working oil pressure in a working oil tank 9 with the external water pressure, an inner sealing member 12 disposed on the side of a cylinder chamber of a piston passage 11 of a cylinder 6, an outer sealing member 13 disposed on the side of an opening of the piston passage 11, a drain circuit 14 extending from between the sealing members 12 and 13 to a working oil tank 9, and a drain control valve 15 which opens the drain circuit 14 only when the working oil pressure between the sealing members 12 and 13 is higher than the internal atmospheric pressure in the enclosure 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an underwater sound source device that prevents gas from entering a hydraulic system.

  Various academic and technical surveys can be conducted using sound in the ocean, lakes, rivers, etc. For example, it is possible to investigate the topography of the bottom of the water and the properties of the substances constituting the bottom by measuring the sound waves that are reflected and returned when the sound waves are emitted in water.

  The sound source device used for this purpose is called an underwater sound source device. A diaphragm is attached to the opening of the enclosure, and a hydraulic actuator that vibrates the diaphragm is provided inside the enclosure so that the diaphragm is vibrated in water. Radiates sound waves into the water. When the frequency of the sound wave is low, in order to vibrate the diaphragm at such a low frequency in water, a hydraulic actuator that reciprocates hydraulically is used.

  Since the underwater sound source device is used while being immersed in water, it is exposed to high water pressure. In order to counteract this water pressure, the enclosure makes the internal pressure of air or nitrogen gas high to balance the internal pressure with the external water pressure.

  On the other hand, since it is necessary to vibrate the diaphragm against high water pressure, the operating oil of the hydraulic actuator is also made high to balance the operating oil pressure with the external water pressure. At this time, the operating oil pressure equalizing apparatus also has a function of absorbing a volume change due to a temperature change of the operating oil.

  By the way, the hydraulic actuator includes a piston rod connected to the diaphragm and a cylinder through which the piston rod is inserted, and strokes the piston rod by supplying and discharging operating oil into the chamber of the cylinder. The diaphragm is vibrated. For this purpose, the cylinder is formed with a piston passage for holding the piston rod in a freely strokeable manner. The piston rod moves back and forth between the cylinder chamber filled with the working oil and the gas atmosphere enclosure through the piston passage.

  In such a hydraulic actuator, it is preferable to provide a seal member in the piston passage so that hydraulic oil does not leak into the enclosure through the piston passage. The seal method recommended by the manufacturer of the seal member is a method called double seal in which seal members are installed at two locations in the piston passage. And when employ | adopting a double seal system, it is necessary to connect a drain circuit between two seal members, and to discharge the operating oil which accumulates between seal members (nonpatent literatures 1 and 2). . The drain circuit communicates with the operating oil tank and guides the operating oil between the seal members to the operating oil tank as it is.

JP-A-8-251687 NOK Corporation Catalog Cat. No. 035-06-99 NOK CORPORATION catalog Cat. No. 038-12-99

  The present inventor adopts the double seal method and installs the drain circuit as recommended by the manufacturer for the hydraulic actuator of the underwater sound source device.

  However, in the case of an underwater sound source device, it has been found that there are special problems that are not found in general hydraulic devices. That is, a general hydraulic device is installed and operated in the atmosphere. On the other hand, as described above, the underwater sound source device balances the operating hydraulic pressure with the external water pressure, and on the other hand, the hydraulic actuator operates in an atmosphere inside the enclosure controlled to a high pressure equivalent to the external water pressure. .

  As shown in FIG. 4, the cylinder 6 of the hydraulic actuator is formed with a piston passage 11 that holds the piston rod 5 in a strokeable manner, and an inner seal member 12 is disposed on the cylinder chamber side of the piston passage 11. The outer seal member 13 is disposed on the opening side of the piston passage 11. The drain circuit 14 reaches the working oil tank 9 from between the inner seal member 12 and the outer seal member 13 of the piston passage 11.

  The internal pressure of the enclosure 2 is Pe, and the operating oil pressure in the operating oil tank 9 is Pt. The operating oil pressure between the two seal members 12 and 13 and the operating oil tank 9 are communicated by the drain circuit 14 so that the operating oil pressure between the two seal members 12 and 13 is the same as the operating oil pressure Pt in the operating oil tank 9. is there.

  The internal air pressure Pe of the enclosure 2 is balanced with the external water pressure by an internal air pressure adjusting means (not shown) and the operating oil pressure Pt in the operating oil tank 9 is balanced by a hydraulic pressure equalizing device (not shown). However, since these two pressures Pe and Pt are controlled by different systems, they are not necessarily the same pressure. Here, it is assumed that the internal pressure Pe of the enclosure 2 is higher than the operating oil pressure Pt in the operating oil tank 9.

  As shown in FIG. 4, the internal gas in the enclosure 2 passes through the outer seal member 13 from the piston passage 11 and enters the drain circuit 14. The inner seal member 12 and the outer seal member 13 are originally for sealing oil, and the material and properties are adapted to the purpose and are configured to seal gas. Absent. For this reason, it is inevitable that gas enters due to the pressure difference. Thus, the gas that has entered the drain circuit 14 enters the hydraulic oil tank 9 (the gas inflow path is indicated by a broken-line arrow).

  As described above, the pressure equalizing device for operating oil also has a function of absorbing a volume change due to a temperature change of the operating oil. By adjusting the volume to be constant regardless of the temperature, an appropriate stroke range can be secured in the hydraulic actuator. However, when a gas flows into the working oil tank filled with the working oil in a sealed structure, a situation equivalent to an unexpected volume change in the working oil occurs. For this reason, the volume change absorbing function of the pressure equalizing device becomes insufficiency, and a problem occurs in stroke control in the hydraulic actuator. Moreover, if the volume change beyond expectation arises in hydraulic fluid, it will cause a failure | damage of a hydraulic fluid tank. Furthermore, if the hydraulic pump sucks gas, it causes cavitation.

  In this way, in the underwater sound source device, the internal air pressure Pe of the enclosure is balanced with the external water pressure by the internal air pressure adjusting means, and the operating oil pressure Pt in the operating oil tank is balanced with the external water pressure, respectively. As a special problem that does not exist, a malfunction occurs in the hydraulic actuator due to gas intrusion from the outer seal member.

  Therefore, an object of the present invention is to provide an underwater sound source device that solves the above-described problems and prevents gas from entering the hydraulic system.

  In order to achieve the above object, the present invention includes a hollow enclosure immersed in water, a diaphragm that closes an opening formed in the enclosure, and a piston rod that is disposed in the enclosure and connected to the diaphragm. And a cylinder through which the piston rod is inserted, and by supplying and discharging operating oil to and from the chamber of the cylinder, the piston rod is stroked to excite the diaphragm and radiate sound waves into the water. In the sound source device, the internal air pressure adjusting means for balancing the internal air pressure of the enclosure with the external water pressure, the operating oil tank filled with the operating oil, and the operating oil pressure in the operating oil tank for balancing the external oil pressure From the cylinder chamber side to the opening side of the hydraulic pressure equalizing device and the piston passage that holds the piston rod of the cylinder in a strokeable manner A plurality of seal members arranged to prevent leakage of operating oil, a drain circuit extending from between the seal members of the piston passage to the operating oil tank, and only when the operating hydraulic pressure between the seal members is higher than the internal pressure of the enclosure And a drain regulating valve for opening the drain circuit.

  The drain regulating valve is a valve having a hydraulic resistance such as a relief valve, a check valve, a throttle valve, etc., and is opened only when the operating oil pressure between the seal members is higher than the operating oil pressure of the operating oil tank. Also good.

  The present invention exhibits the following excellent effects.

  (1) Gas intrusion into the hydraulic system can be prevented.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  Here, a case where there are two seal members, an inner seal member and an outer seal member, will be described.

  As shown in FIG. 1, an underwater sound source device 1 according to the present invention includes a hollow enclosure 2 that is immersed in water, a diaphragm 4 that closes an opening 3 formed in the enclosure 2, and an enclosure 2. And a piston rod 5 connected to the diaphragm 4 and a cylinder 6 through which the piston rod 5 is inserted. By supplying and discharging the working oil 7 to and from the chamber of the cylinder 6, the piston rod 5 is caused to stroke and the diaphragm In the underwater sound source device 1 that oscillates 4 and emits sound waves into the water, an internal air pressure adjusting means 8 for balancing the internal air pressure of the enclosure 2 with the external water pressure, a working oil tank 9 filled with the working oil 7, A hydraulic pressure equalizing device 10 for balancing the hydraulic pressure in the hydraulic oil tank 9 with the external water pressure, and a piston passage 11 for holding the piston rod 5 of the cylinder 6 in a freely strokeable manner. An inner seal member 12 that is disposed on the side of the Linda chamber and prevents leakage of operating oil, an outer seal member 13 that is disposed on the opening side of the piston passage 11 and prevents leakage of operating oil, and an inner seal member 12 of the piston passage 11. The drain circuit 14 extending from between the outer seal member 13 to the operating oil tank 9 and the drain circuit 14 is opened only when the operating hydraulic pressure between the inner seal member 12 and the outer seal member 13 is higher than the internal pressure of the enclosure 2. A drain regulating valve 15.

  Between the opening 3 of the enclosure 2 and the diaphragm 4, a flexible seal member 16 such as a diaphragm that allows the diaphragm 4 to vibrate and maintains watertightness is provided.

  The inside of the cylinder 6 is partitioned into a front cylinder chamber 18 and a rear cylinder chamber 19 by a piston head 17 integrated with the piston rod 5. The cylinder 6 is provided with a servo valve 20 for supplying and discharging operating oil to and from the front cylinder chamber 18 and the rear cylinder chamber 19. When the servo valve 20 supplies operating oil to the front cylinder chamber 18, the volume of the front cylinder chamber 18 increases, the piston head 17 moves rearward (rightward in the figure), and the piston rod 5 strokes rearward. When the servo valve 20 supplies operating oil to the rear cylinder chamber 19, the volume of the rear cylinder chamber 19 increases, the piston head 17 moves forward (leftward in the figure), and the piston rod 5 strokes forward. The piston rod 5, the cylinder 6, and the servo valve 20 constitute a hydraulic actuator for exciting the diaphragm 4.

  The hydraulic oil tank 9 is a closed type, and a hydraulic pump 21 is provided in the hydraulic oil 7 in the hydraulic oil tank 9. An oil supply pipe 22 is provided from the hydraulic pump 21 to the servo valve 20, and a return pipe 23 is provided from the servo valve 20 to the inside of the working oil tank 9.

  The hydraulic pressure equalizing apparatus 10 includes an expansion / contraction chamber that communicates with the working oil tank 9 via a bottleneck. When the operating oil 7 is thermally expanded when the external water pressure is constant, the operating oil 7 flows into the expansion / contraction chamber from the operating oil tank 9, and when the operating oil 7 is thermally contracted, the operating oil 7 flows into the operating oil tank 9 from the expansion / contraction chamber. The volume change of the operating oil 7 is used for the oil amount change in the expansion / contraction chamber. In addition, when the external water pressure increases, the operating oil 7 flows into the operating oil tank 9 from the expansion / contraction chamber, and when the external water pressure decreases, the operating oil 7 flows from the operating oil tank 9 into the expansion / contraction chamber. The hydraulic pressure is always balanced with the external water pressure.

  The internal air pressure adjusting means 8 includes a gas cylinder 24 that stores high-pressure gas, an air supply valve 25 that introduces gas from the gas cylinder 24 into the enclosure 2, and an exhaust valve 26 that exhausts gas from the enclosure 2 into water. . Further, the internal air pressure adjusting means 8 includes a water pressure sensor (not shown) for detecting the water pressure outside the enclosure 2, an air pressure sensor (not shown) for detecting the air pressure inside the enclosure 2, and the difference between the water pressure and the air pressure. A control unit (not shown) that controls the air supply valve 25 and the exhaust valve 26 to balance the internal air pressure of the enclosure 2 with the external water pressure.

  The inner seal member 12 and the outer seal member 13 are known hydraulic device seal members, and are configured by combining, for example, an O-ring and a rare freon ring. A double seal is configured by installing these seal members 12 and 13 at two locations of the piston passage 11. The drain circuit 14 discharges the working oil accumulated between the inner seal member 12 and the outer seal member 13 constituting the double seal to the working oil tank 9 so as not to deteriorate the working oil sealing function of the double seal. Is to do.

  In the present invention, a drain regulating valve 15 is installed in the drain circuit 14. The drain regulating valve 15 is a valve having hydraulic resistance such as a relief valve, a check valve, a throttle valve, etc., and the operating oil pressure between the inner seal member 12 and the outer seal member 13 is higher than the operating oil pressure of the operating oil tank 9 by a predetermined pressure. Only when it is open.

  Next, the operation of the underwater sound source device 1 of the present invention will be described.

  In the hydraulic actuator, the servo valve 20 feeds / discharges the working oil 7 into / from the cylinder 6, so that the piston rod 5 strokes back and forth. When the diaphragm 4 is vibrated by the piston rod 5, sound waves are radiated into the water.

  At this time, the working oil 7 is supplied to the cylinder 6 through the servo valve 20 from the hydraulic pump 21 built in the working oil tank 9. The hydraulic pressure equalizing device 10 provided in the hydraulic oil tank 9 absorbs the volume change due to thermal expansion / contraction of the hydraulic oil 7 and balances the hydraulic pressure in the hydraulic oil tank 9 with the external water pressure.

  On the other hand, gas is enclosed in the enclosure 2, and the internal air pressure of the enclosure 2 is balanced with the external water pressure by the internal air pressure adjusting means 8. However, since the internal air pressure adjusting means 8 controls the difference between the internal air pressure and the external water pressure to be within a predetermined value, a certain range of error is allowed between the internal air pressure and the external water pressure. Therefore, the internal air pressure of the enclosure 2 may be higher than the operating oil pressure in the operating oil tank 9.

  Here, as already explained, in the conventional configuration of FIG. 4, the gas in the enclosure 2 passes through the outer seal member 13 from the piston passage 11 and enters the drain circuit 14, and then passes through the drain circuit 14 to the operating oil tank 9. to go into.

  On the other hand, in the present invention, as shown in FIG. 2, the drain control valve 15 is provided in the drain circuit 14. For example, the drain regulating valve 15 uses the cracking pressure of the relief valve to make the operating hydraulic pressure Pd between the seal members higher than the internal pressure Pe of the enclosure. Specifically, a predetermined pressure difference is generated in the relief valve so that the operating oil pressure Pd between the seal members 12 and 13 is higher than the operating oil pressure Pt of the operating oil tank 9 by a predetermined pressure. . If the pressure difference exceeds the upper limit of the error between the internal air pressure Pe and the external water pressure by the internal air pressure adjusting means 8, the operating oil pressure Pt of the operating oil tank 9 is balanced with the external water pressure. The operating hydraulic pressure Pd between the members becomes higher than the internal pressure Pe of the enclosure.

  Thereby, the gas in the enclosure 2 is prevented from passing through the outer seal member 13 from the piston passage 11 and entering the drain circuit 14, and the gas is prevented from entering the working oil tank 9.

  In the above embodiment, the drain regulating valve 15 is provided to increase the operating hydraulic pressure Pd between the seal members, and thus is not limited to a relief valve but may be a check valve or a throttle valve. Further, the drain circuit 14 may be connected to the return pipe 23 instead of being directly drawn into the working oil tank 9.

  In the above embodiment, a set of the diaphragm 4 and the hydraulic actuator is provided, but a plurality of sets may be provided. In the above embodiment, the number of seal members is two, that is, the inner seal member 12 and the outer seal member 13, but the present invention can also be applied to the case where three or more seal members are provided.

  The underwater sound source device 31 shown in FIG. 3 is provided with two sets of the diaphragm 4 and the hydraulic actuator 32. The strokes of the piston rod 5 are reversed by the two hydraulic actuators 32 so that the reaction forces generated when the diaphragm 4 is vibrated in the two hydraulic actuators 32 can be canceled out. I do. In this case as well, as in the case of FIG. 1, a double seal 33 is provided in each piston passage, a drain circuit 14 is provided from the middle of each double seal 33 to the hydraulic oil tank 9, and a drain regulating valve 15 is provided in each drain circuit 14. Is provided.

It is a block diagram of the underwater sound source device which shows one Embodiment of this invention. It is the elements on larger scale of the underwater sound source device of FIG. It is a block diagram of the underwater sound source device which shows other embodiment of this invention. It is the elements on larger scale of the conventional underwater sound source device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Underwater sound source device 2 Enclosure 3 Opening part 4 Diaphragm 5 Piston rod 6 Cylinder 7 Operating oil 8 Internal pressure adjusting means 9 Operating oil tank 10 Hydraulic pressure equalizing device 11 Piston passage 12 Inner seal member 13 Outer seal member 14 Drain circuit 15 Drain Regulatory valve

Claims (2)

A hollow enclosure immersed in water, a diaphragm for closing an opening formed in the enclosure, a piston rod disposed in the enclosure and connected to the diaphragm, and a cylinder through which the piston rod is inserted An underwater sound source device that radiates sound waves into the water by exciting the diaphragm by stroking the piston rod by supplying and discharging operating oil into the cylinder chamber,
An internal air pressure adjusting means for balancing the internal air pressure of the enclosure with the external water pressure;
A working oil tank filled with the working oil;
A hydraulic pressure equalizing device for balancing the working oil pressure in the working oil tank with the external water pressure;
A plurality of seal members that are disposed from the cylinder chamber side to the opening side of the piston passage that holds the piston rod of the cylinder so as to be freely stroked, and prevent leakage of operating oil;
A drain circuit extending from between the seal members of the piston passage to the hydraulic oil tank;
A drain regulating valve that opens the drain circuit only when the operating hydraulic pressure between the seal members is higher than the internal pressure of the enclosure;
An underwater sound source device characterized by comprising:   The drain regulating valve is a valve having a hydraulic resistance such as a relief valve, a check valve, a throttle valve, etc., and is opened only when the operating hydraulic pressure between the seal members is higher than the operating hydraulic pressure of the operating oil tank. The underwater sound source device according to claim 1.

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