JPH0764308B2 - Method and apparatus for maintaining gas pressure in an underwater casing in equilibrium with external pressure - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method and a device for keeping the inside of a gas-filled underwater casing in pressure equilibrium with the outside.

The technical field of the invention relates in particular to the construction of underwater devices which are electro-acoustic transducers.

[Prior Art and its Problems] A casing that is submerged in water extremely deep must withstand the high hydrostatic pressure that causes the mechanical structural stress of the casing.

In some cases, the interior of the casing communicates with the exterior, which constantly balances the pressure and the casing wall does not have to withstand any pressure. However, in many cases, water does not enter the underwater casing, and an electronic or electric device or circuit is arranged inside the casing so as not to come into contact with the water or the liquid inside.

In such a case, the interior of the casing is in communication with a deformable bag filled with gas, which bag is submerged in the water at the same time as the casing. Therefore, the gas in the casing is always kept at a hydrostatic pressure.

In the following explanation, the piezoelectric transducer (piezo-electri
c piezoelectrics), this piezoelectric transducer comprises for example a sonar antenna,
It needs to go very deep, on the order of hundreds to thousands of meters. Note that such selection does not limit the present invention, and the present invention can be applied to other underwater casings.

Currently, submerged transducer
s) is a plurality of piezoelectric elements (pie
zo-electric element) and is arranged in a watertight housing. The housing is connected by a pipe to a deformable bag or bag made of elastic material, which is arranged in a casing for mechanical protection and communicates with the surroundings. When the bladder is filled with atmospheric air and the volume of the transducer housing is relatively large, the compensating hydrostatic pressure of such a system can only accommodate a limited depth. Actually, if V ₀ is the initial volume of the bag, V ₁ is the volume of air in the housing, P ₀ is the initial pressure, and P is the hydrostatic pressure when all the air in the bag flows into the housing, The relationship is established.

P ₀ (V ₀ + V ₁ ) = P ₁ V ₁ Therefore, when submerging to a depth of 500 m, which corresponds to a hydrostatic pressure of P ₁ / P ₀ = 1 + V ₀ / V ₁ 50 bar, the bag body is initially A volume equal to 49 times the total volume of the transducer housing at pressure P ₀ = 1 bar is required. The volume of such bags cannot be dimensionally matched.

To reduce the air volume, a compensation system is used, which comprises a deformable bladder or bag pre-inflated with a pressure P ₀ equal to several times atmospheric pressure. For example P ₀ = 5ba
r, V ₀ / V ₁ = 19, the hydrostatic pressure limit is P ₁ = P ₀ × 20 or
P ₁ = 100 bar or maximum diving depth of 1000 meters.

This method requires the transducer housing to withstand and undergo initial pressure from the beginning of the dive.

Housings with significant volume cannot withstand high internal pressures, which limits the depth of dive with pressure compensation systems that include a pre-inflated bladder.

According to another method, the transducer housing is coupled to a compressed air cylinder provided with a pressure reducing valve such as used in diving.

In this case, while the transducer and cylinder settle,
The pressure reducing valve discharges air at a pressure approximately corresponding to the hydrostatic pressure.
Despite the small volume of the cylinder relative to the volume of the housing, it can be submerged fairly deep if it contains high pressure compressed gas. For example, if the initial pressure in the cylinder is 50 bar and the ratio V ₀ / V ₁ = 1/10, a hydrostatic pressure of 55 bar or a depth of 550 m can be reached. When surfacing to the surface, an overpressure is created in the housing and the valve or pressure reducing valve can expel excess air.

According to this method, air bubbles are generated when levitating to the surface, which is the underwater sonar antenna (su) used for military purposes.
bmerged sonar antenna) is not necessary.

Moreover, in the event of a poor operation of the pressure reducing valve, there is a risk of creating an unbearable excess pressure in the housing and thus of the housing and the equipment inside.

Moreover, if the transducer forms part of a diving machine that is leaked by ship, the sinking depth will change constantly, causing air bubbles to be expelled each time the transducer rises, resulting in unexpected air consumption. And the pressure difference between the inside and the outside of the housing may exceed its mechanical strength.

The object of the present invention is to equilibrate the gas pressure in this casing with the hydrostatic pressure by means of a variable bag or bag filled with a gas that is submerged with a submersible or submersible casing, so that a large volume bag or casing can be expanded without pre-expansion. It is to provide a means by which one can dive into depth.

The method according to the invention simultaneously dives a casing and a variable bag filled with gas and in communication with this casing.

[Means, Actions and Effects for Solving the Problems] The above-mentioned object of the present invention is to immerse a large number of variable bags filled with gas compressed respectively at different pressures in water at the same time as the casing, and to reduce the hydrostatic pressure during sedimentation. By the method of automatically connecting the casing and each small bag when the gas pressure in the bag is almost reached, and automatically separating each bag when the internal pressure reaches the initial pressure while floating on the surface To be achieved.

The device of the present invention comprises a casing, which is submerged with a gas-filled variable bag in communication with the casing.

The device according to the invention comprises a number of variable bags, each filled with a gas of a different pressure, which bags are connected in parallel to a manifold connected to the casing, other than the bag containing the lowest pressure gas. The bag is connected to the manifold by a three-way valve which communicates between the bag and the manifold when the hydrostatic pressure is approximately equal to the pressure in the bag and the hydrostatic pressure is slightly less than the pressure in the bag. Sometimes it is automatically controlled by means of automatically disconnecting communication.

According to a preferred embodiment, each variable bag is arranged in a bottle-shaped metal casing, which casing comprises a first cylindrical shell closed by a cover and a second cylindrical shell closed by a convex bottom. , These shells are assembled together with two flanges, the opening of the bag is clamped airtight between these flanges, the convex bottom has an opening communicating hydrostatic pressure to the outside of the bag, Has an opening communicating the interior of the bag with a manifold or one of the three-way valves.

According to the invention, the submersible casing can be submerged very deeply and is kept filled with gas at a pressure equal to the hydrostatic pressure without the use of a bulky variable bag.

The device of the present invention uses a bag that has been pre-inflated above the surface of the water, which allows it to be sunk very deeply, without the need for overpressure in the casing as is conventional. Especially in the case of electro-acoustic transducers, it may not be possible to form them to withstand overpressure.

The overall dimensions of the device according to the invention can be smaller than to the extent that conventional diving is possible.

The device according to the present invention can easily cope with various diving depths, for example, in the case of a sonar antenna which leaks and the diving depth changes during the leaking.

The device according to the invention can double the number of stages, that is the number of bags filled with different initial pressures, and can be sunk very deeply.

For example, for an electro-acoustic transducer that cannot withstand internal overpressure, the minimum residual volume that must withstand a long dive at a depth of 250 m is 4 liters, which varies.

Pre-inflated deformable bags cannot be used because this transducer cannot withstand overpressure.

A cylinder provided with a decompression source, which has a limited self-control range and cannot know when the amount of air becomes insufficient, cannot be used.

A bag filled with atmospheric pressure air can be used, but in this case an initial air volume of 400 liters is required to dive up to 250 m.

If the device of the invention has a two-stage configuration expanded to 72 liters at 1 bar and 3 bar respectively, the initial volume is 144
One liter is enough.

The device of the present invention is 37 bar at 1 bar, 2.3 bar and 7.6 bar respectively.
With a three-stage configuration expanded to liters, an initial volume of 111 liters is sufficient.

In the case of a four-stage configuration of 25 liters each, the initial volume is
It is 100 liters. Thus, the device according to the invention can significantly reduce the initial volume of gas required to maintain the casing at an equal pressure without the conventional overpressure inside.

[Embodiment] FIG. 1 shows a conventional type electro-acoustic transducer (el
ectro-acoustic transducers) having a watertight housing containing voltage plates inserted between the electrodes. The housing is filled with gas.

The housing of the transducer is connected to a pipe 2, which is, for example, a supply pipe which can withstand hydrostatic pressure or external pressure. The pipe 2 is connected to a dehumidifier 3 containing, for example, silica gel which absorbs moisture in the air.

The dehumidifier 3 is connected by a pipe 4 to an assembly of three deformable bags filled with gas, namely variable bags 5, 6, 7.

FIG. 2 shows an axial sectional view of one of the bags 6,7.
Each bag is provided with a metal casing, which has first and second cylindrical shells 8, which are flanged together.
This second cylindrical shell 9 is closed by a convex bottom 9a and the opposite end of the first cylindrical shell 8 is closed by a cover 10. The cover 10 is provided with a valve 11, which communicates the casing with an automatic three-way valve 12 described below.

The metal casing comprises a bag or bag 13 made of a deformable elastic material, the opening of which is clamped in an airtight manner between two flanges 8b.9b for assembling the shells 8,9. The convex bottom 9a has an opening 14 which is closed by a valve 15 when the bag is inflated.

Reference numeral 16 indicates an end piece for inflation.

FIG. 2 shows the bag body 13 in an inflated state.

3 and 4 are axial sectional views of the automatic three-way valve 12 mounted on the bags 6 and 7, respectively.

3 and 4 show two functions of the same valve. As shown, each valve is provided with an axial gas passage 17, which communicates with the inside of the bag in which the valve is mounted via a passage 11a, which is closed by the valve 11. .

The valve body 19 is provided with two grooves 20a, 20b, each of which communicates with a transverse groove into which a threaded end piece 21a, 21b is screwed, which end piece has two pipes 22, 23 are combined.

The valve body 19 comprises a base, which is fastened by screws 24 to the cover 10 of the casing 1 which encloses the bag.

The valve body contains two pistons 25,26, which are deformable variable membranes 25a, 26 made of a cross-linked elastic material.
It is fixed to a. Two pistons are axial rods 2
The rods are integrally connected at 7, and an axial groove 17 is provided in the rod. The rod 27 is fitted with two seals 28a, 28b, which change with the movement of the rod,
Determines communication between the three directions. Oil is filled between the membrane 25a and the lower seal 28b.

The upper part of the valve body is closed by a tight variable membrane 29, the outer surface of which is in contact with water. The space between the two membranes 29, 26a is filled with oil, which communicates via the groove 30 formed in the rod 27 with the oil-filled space between the lower seal 28b and the membrane 25a. .

The axial air passage 17 is provided at its upper end with two passages 31, 32, which communicate with the space between the membrane 26a and the upper seal 28a. The valve of FIGS. 3 and 4 is formed so that the mechanical part contacts seawater.

Hydrostatic pressure is exerted on the membrane 29, and the oil exerts this pressure on two pistons.
Reach 26,25.

A moving part assembly consisting of two pistons joined by a rod increases the hydrostatic surface and improves operational reliability.

The valve further comprises a return spring 33, which abuts the valve body and returns the two pistons towards the lower or casing containing the inflated bladder.

As shown in FIG. 1, the bag 5 is inflated at atmospheric pressure or slightly higher pressure and directly connected to the air pipe without passing through the valve 12. The bag 6 is inflated to an intermediate pressure, for example 8 bar, and the bag 7 is inflated to a high pressure, for example 20 bar, which bag can withstand this pressure and by means of the metal housing 9,9a carrying the variable bag. .

The operation is as follows.

The bags 6,7 are inflated by connecting inflation means on the end piece 16. The pressure in each bag returns the valve pistons 25, 26 mounted in the bag to the position shown in FIG.
In this position the two grooves 20a, 20b are located between the two seals 28a, 28b, the lateral passages of the valves are in communication with each other and the orifices 31, 32 are not in communication with the lateral outlets, so that No gas is emitted.

When the transducer and the bags 5, 6, 7 connected to it as shown in FIG. 1 are submerged, hydrostatic pressure acts on the membranes 29 of the two valves and is transferred to the oil in each valve. The hydrostatic pressure acts on the variable bag 5, which is contracted and the enclosed gas is expelled towards the transducer housing,
Hold this housing equal to the water pressure. Variable bag 5
The volume of is calculated so that it is not completely compressed when it reaches an intermediate pressure of 8 bar. When the variable bag 5 reaches the cover 10, it contacts the valve 11 and closes it.

When an intermediate pressure of 8 bar is reached, the valve 12 mounted on the intermediate bag 6 automatically repositions. In fact, at this time, the two pistons 25 and 26 mounted on this valve receive hydrostatic pressure on the upper surface and the same gas pressure in the bag 6 on the lower surface.

The return spring 33 returns the two pistons downward, the valve automatically moves to the position shown in FIG. 3, the upstream bag 5 is shut off and the bag 6 communicates with the transducer. Valve 12
Is a pressure regulator (pr) that compares the hydrostatic pressure to the pressure in the variable bag and automatically activates the valve when the two pressures are equal.
essostat) is formed.

Upon further diving, the gas in the intermediate bag 6 is forced into the transducer to equalize the pressure.

When the hydrostatic pressure reaches the pressure in the third bag 7, that is, 20 bar, the valve 12 equipped in the bag 7 detects that the pressures become equal and automatically moves to the position shown in FIG. 3 bags communicate with the transducer.

In case of ascending to the surface, it works automatically contrary to the above.

When the hydrostatic pressure decreases, the bag 7 is inflated, a part of the gas in the transducer is sent into the bag, and the hydrostatic pressure becomes 20 ba.
When the pressure is reduced to r, the bag is completely filled. When the pressure in the bag 7 becomes higher than the hydrostatic pressure, the gas pressure acts on the lower surfaces of the pistons 25 and 26, and the valve 12 equipped with the bag 7
To move. This valve again occupies the position shown in FIG.
The gas in the transducer gradually fills the bag 6 until the pressure in the intermediate bag 6 is fully inflated at a pressure equal to the hydrostatic pressure.
Sent to.

The variable bag 6 is in contact with the metal casing that contains the variable bag 6 and cannot expand any further. When the pressure in the bag becomes higher than the hydrostatic pressure, the valve 12 of the intermediate bag 6 moves and the transducer is moved to the bag 5 until it floats on the water surface.
Communicate with.

Obviously, the device described above allows the casing to be submerged without draining water bubbles into the water and without creating an overpressure inside.

This is due to the use of a series of relatively small volume variable bags.

5 and 6 show a modification in which a solenoid valve controlled by a static pressure switch is used instead of the automatic valve 12 which is directly controlled by differential pressure.

FIG. 5 is an axial sectional view of a 3-way solenoid valve 35 provided in one of the two casings containing the variable bags 6 and 7.

For example, one passage 36 arranged on the right side of FIG. 5 is provided in the transducer when the solenoid valve is equipped in the bag 7, or in the bag 7 when the electronic sentence is equipped in the bag 6. Be combined. The other passage 37 is connected to a bag equipped with a solenoid valve. The third passage is the upstream bag, ie bag 5 if bag 6 is equipped with a solenoid valve.
In addition, when the bag 7 is equipped with a solenoid valve, it is connected to the bag 6.

Each solenoid valve includes a coil 39 and a movable core, and a rod 40 extending from the movable core slides in an axial inner hole where three passages are opened at different positions.

The movable rod 40 has three seals 43a, 43b, 43c and two grooves 41, 42 formed between the two seals.

The rod 40 is returned downward by the return spring 44.

FIG. 5 shows the solenoid valve in a state where the electromagnet coil is not excited. The spring 44 holds the rod 40 downward. In this position, the passage 38 communicates with the passage 36 and the passage 37 from the bag equipped with the solenoid valve is blocked.

FIG. 6 shows one of the bags 6 and 7, the valve 11 and the passage 1 through which the gas flows.
FIG. 3 is a sectional view in the axial direction of a cover 10 of a casing including 1a and 1a.

The cover 10 has a closed space 45 and a pipe 37 connected to one of the passages of the solenoid valve, and a passage 11a is opened in the eating trunk. The space 45 contains a micro switch 46, and this micro switch is connected via an electric wire.
It is coupled to an electromagnet 39 which controls the solenoid valve. This wire extends from the cover via a tightly mounted connector 47.

The space 45 is closed by a cover, which is provided for the two metal parts 48, 49, so that a space is formed in these metal part tubes. An elastic metal film 50 is arranged in this space, and the central portion of this metal film abuts a rod 51 which operates the microswitch.

The metal part 48 has a passage 52 which communicates the space part 45 with the space arranged below the membrane 50, whereby the gas pressure in the casing acts on the lower surface of the membrane 50.

Further, the metal part 49 is provided with a passage 53 penetrating the metal part 49. The device further comprises a variable membrane 54 made of an elastic material, which is arranged in contact with water and is held in an airtight manner above the metal part 49 by means of a flange 55. The space between membrane 54 and membrane 50 is filled with hydrostatic oil. As long as the hydrostatic pressure is also low in the casing, the membrane 50 is pulled and the microswitch 46 is held open.

The electromagnet 39 controlled by the microswitch 46 is not excited and the solenoid valve 35 is arranged in the position shown in FIG.

When the hydrostatic pressure is approximately equal to the pressure in the casing, the elastic membrane 50 bends back to the rest position and the rod 51 closes the microswitch.

When the electromagnet is energized, the solenoid valve 35 communicates the passage 36 with the passage associated with the casing having the associated solenoid valve.

FIG. 7 is a sectional view of the air dehumidifier 3 shown in FIG. This dehumidifier removes moisture from the air even after diving for a long time and keeps it in a state of impression. This dehumidifier comprises a housing made of, for example, methyl methacrylate and a cartridge 57 of a hygroscopic material such as silica gel for absorbing particles in the air.
And the hygroscopic material is arranged in a lattice or mesh case that allows air to flow therethrough. This hygroscopic material contains a substance whose color changes according to humidity. Air flowing through the two cartridges flows from one central passage to the other central passage. The transparent body 56 is closed by a removable bottom portion 58, which allows it to be regenerated by replacing the cartridge and inserting it while it is open.

8 and 9 show an elevation view in which a part of a sonar antenna having a substantially cylindrical shape is cut away and a view along the line IX-IX,
Tnpilz type mounted on the support structure 60 (Tnpilz
type) transducer column. In this example, each transducer column has a pair of casings 61,6.
2 is used. Each of the casings 61 and 62 contains a variable bag arranged so as to come into contact with water. The casing 61 is filled with atmospheric pressure gas, and the casing 62
Is filled with gas compressed to, for example, 5 bar. A three-way valve 63 shown in FIGS. 3 and 4 is mounted on the casing 62. The outlet passage of the valve 63 is connected to the dehumidifier 3, which is itself connected to a manifold 64, to which the transducer of the column is connected in parallel. 8 and 9 show that the casing 61, 62 can be easily accommodated within the pointing structure of the antenna without increasing the space due to the reduction in volume.

[Brief description of drawings]

FIG. 1 is an overall view of an apparatus according to an embodiment of the present invention, FIG. 2 is an axial sectional view of a metal casing containing a variable bag, and FIGS. 3 and 4 are automatic valves installed in the casing of FIG. FIG. 5 is an axial sectional view of a solenoid valve mounted on the casing of FIG. 2, and FIG. 6 is a sectional view of a hydrostatically controlled switch associated with the solenoid valve of FIG. FIG. 7 is a cross-sectional view of the dehumidifier, and FIGS. 8 and 9 are an elevation view and a view taken along line IX-IX of a sonar antenna equipped with a device according to an embodiment of the present invention. 1 ... Casing, 2 ... Pipe, 3 ... Dehumidifier, 4 ...
... manifold, 5,6,7 ... variable bag, 8,9 ... shell,
10 …… Cover, 12,35 …… 3-way valve, 25,26 …… Piston,
27 …… Rod, 46 …… Micro switch.

Claims (10)

[Claims] 1. A method for simultaneously immersing a casing (1) and a variable bag, which is connected to the casing and is filled with gas, to maintain the gas pressure in the underwater casing in equilibrium with an external pressure, A large number of variable bags filled with gases of different pressures are immersed in water at the same time, and when the hydrostatic pressure almost reaches the gas pressure in the bag during sedimentation,
A method for automatically connecting the casing and each bag, and automatically separating each bag when the internal pressure reaches an initial pressure while floating on the surface. 2. A casing (1), comprising at least one variable bag communicating with the casing and filled with gas, the variable bag being immersed together with the casing to change the gas pressure in the casing to an external pressure. A device for maintaining equilibrium, comprising variable bags (5,6,7 ...) filled with gases of different pressures, these bags being arranged in parallel with a manifold (4,2) connected to the casing. The other bags (6,7) except the bag (5) containing the lowest pressure gas are connected to the manifold by the three-way valve (12,35), and the three-way valve has a hydrostatic pressure. A means for communicating between the bag (6,7) and the manifold (4) when the pressure in the bag is approximately equal, and automatically breaking the communication when the hydrostatic pressure is slightly lower than the pressure in the bag. Characterized by being automatically controlled Device to do. 3. Each variable bag (13) is arranged in a bottle-shaped metal casing, which casing is a cover (10).
A first cylindrical shell (8) closed with a convex bottom (9)
with a second cylindrical shell (9) closed in a), which shells are assembled together with two flanges (8b, 9b) between which the opening of the bag is clamped airtightly The convex bottom (9a) has an opening (14) communicating external pressure to the outside of the bag, and the cover (10) connects the inside of the bag to the manifold or one of the three-way valves. Device according to claim 2, characterized in that it has an opening (12a) communicating with it. 4. A variable valve (6, 7) other than the bag inflated with the lowest pressure compressed gas is provided with a three-way valve.
The one-way valve comprises two pistons (25,26) connected together by a rod (27), one of the two faces of which receives the pressure in one bag and the other of which is hydrostatic and spring action. And the spring moves the two pistons when the hydrostatic pressure becomes approximately equal to the gas pressure in the bag,
Device according to claim 2 or 3, wherein the bag is in communication with the manifold (4) and at the same time the manifold is separated from the initially inflated bag at a lower pressure. 5. An elastic film (25a, 26a) is provided on each of the pistons.
5. The device according to claim 4, wherein a) is provided and the elastic membrane ensures a positive seal between the piston and the valve body. 6. The rod (27) comprises a longitudinal passage (30) through the upper piston (26), said passage having a space arranged above the upper piston (21) for the inner piston (21). And a seal (28) attached to the rod (27).
b) communicating with spaces arranged between them, these spaces being filled with oil, said valve further having a deformable membrane (29) made of an elastic material, the outer surface of which is 6. A device as claimed in claim 4 or 5, in contact, the inner surface being in contact with the oil. 7. The rod comprises a longitudinal passageway (17) opening below the lower piston (25), the upper end of which is at least one hole (31,32) opening to the outside of the rod.
The device according to claim 4, further comprising: 8. The apparatus according to claim 2, wherein the three-way valve is a solenoid valve (35), and the coil (39) is controlled by a hydraulically controlled microswitch (46). 9. The cover (10) of each metal casing that contains a bag other than the bag containing the gas of the lowest pressure has a space (45) in which the microswitch (46) is housed, and this space is The inside of the bag communicates with the solenoid valve 1 through the passage (11a) and the solenoid valve 1 through the pipe (37) and is closed by a cover made of two metal pieces. An elastic metal film (50) is movably arranged in a space formed between the metal film and the elastic metal film (50), which abuts on a central rod (51) contacting the microswitch. 9. The device according to claim 8, wherein the gas pressure in the bag is received by and the pressure of oil held at a predetermined pressure by the elastic film (54) is received on the other surface. 10. An air dehumidifying device disposed on the manifold (4), the dehumidifying device being formed of a body (56) made of a transparent material and a hygroscopic material absorbing moisture in the air. A device according to any one of claims 2 to 9, further comprising a cartridge (57), the hygroscopic material being a color-changing material, for example silica gel, housed in a breathable lattice structure.