KR20050016464A - Underwater shock protection device - Google Patents

Abstract

The present invention relates to a structure to be installed or operated on the surface or underwater, having a structure for protecting the structure against an underwater shock (bar), the structure includes an elastic member formed on the shell of the structure located underwater . The elastic member may be made of a layer of elastic material having a gas-filled space portion at least spaced apart from the structure, and may be compressed to at least one underwater movement amplitude range according to the underwater impact.

Description

Underwater Shock Protection Device {UNDERWATER SHOCK PROTECTION DEVICE}

The present invention relates to a structure to be installed or operated on the surface or underwater, having a structure that protects the structure against an underwater shock (bar), the structure is an elastic member to be provided on the outer shell of the structure submerged underwater Consists of

Such structures are known as marine vessels modified according to US Pat. No. 4,193,367. The outer shell of the ship is covered with a pre-pressurized membrane, such as a fiberglass plate, to prevent or at least limit the transmission of submerged shock waves into the ship.

Membranes have structural weaknesses in use, which are complex and can easily leak for water masses penetrating between the membrane and the marine vessel, adversely affecting the boating properties of the marine vessel. Moreover, due to the leak phenomenon, the protection is reduced or eliminated by the impact. In addition, relatively large surfaces near the edges of the membrane will be vulnerable to collisions with continuous shock waves. In this position, the impact will be partially transmitted to the ship.

1 is a schematic cross-sectional view of a marine ship, such as a frigate, with a protective structure according to the invention.

2 is a schematic cross-sectional view of a submarine with a protective structure according to the present invention.

3 is a detailed view of a protective structure according to the first embodiment.

4 is a detailed view of the protective structure according to the second embodiment.

5 is a schematic view of a protective structure according to a third embodiment.

It is an object of the present invention to provide an improved structure which is relatively simple, inexpensive to manufacture and maintain, and does not adversely affect the operational performance.

The object is achieved by providing a structure having the structure described above, wherein the elastic member is made of a layer of elastic material such that the elastic member has a gas filled space on at least a side spaced from the structure and at least one underwater travel width that will result from underwater impact It can be compressed more than.

As such a structure, a protective layer is formed around the vessel so that pressure waves that would result from underwater explosions cannot reach the marine ship. Since the protective layer has a very low acoustic impedance, the pressure wave is reflected back into the water like a reflected wave. Then, the energy of the shock wave is absorbed in water, and in a similar manner, bulk-cavitation occurs as a reflection effect near the water surface. As a result, the energy of the submerged shock wave is hardly transmitted because no additional impact protection means are required on the marine ship unless the path of the pressure wave exceeds the maximum travel distance of the elastic material. The internal structure of the marine ship has the advantage of having the required impact resistance no less than the prior art that protects against underwater shock. In addition, the present invention can be used without using complicated mechanical structures which are expensive to maintain and easily defective.

In practice, reflex phenomena have completely different characteristics from suppressing the collision between the ocean line and the ocean waves. For example, in a structure known as US Pat. No. 3,960,100, the impact energy is stored as elastic energy in the gas chamber and transmitted to the marine vessel in a reduced manner, that is to say a low maximum force. The maximum underwater displacement for shock waves (approximately 6-10 cm) is relatively small and the thickness of the relatively limited material is large enough to achieve a very robust and easily used structure.

In a preferred embodiment, the space portion is connected to the gas pressure regulating device. Particularly in submarines, submarines can withstand water pressure so they can operate in the deep sea, so the volume of the chamber is very small because the pressure wave has a travel path larger than the diameter of the chamber or the height of the chamber. The adjustment of the gas volume and pressure in the chamber can prevent "bottoming", that is, the impact of internally colliding elastic materials, that is, shock waves are no longer reflected and enter the ocean. In addition, the regulator has the advantage of eliminating small amounts of leaks, for example due to the diffusion or local leakage of gas from the chamber.

In another preferred embodiment, the space portion is connected to the gas buffer member. Such a member prevents a part of the gas from flowing to the buffer during the compression process so that the height gas pressure is raised in the chamber. As a result, the chamber can be designed relatively small.

In addition, the outside away from the structure has a relatively low specific gravity and the inside has a relatively high specific gravity has the advantage of having a gradient according to the specific gravity of the elastic material. Due to the low specific gravity from the outside, the amplitude difference between the nearby water and the impact protection structure increases, so that the reflection of the shock wave occurs better. Since the specific gravity is increased toward the inside, the structure can take a rigid structure, while the shock absorbing force of the elastic material can be optimized and used.

In order to improve the navigation performance and mechanical strength, a relatively thin and rigid plate may be provided outside the elastic material. The plate may be made of steel, aluminum, fiberglass or other relatively light material that is not very thick, but must pass the shock wave relatively well.

In a preferred embodiment, the gas filled elastic material is made of homogeneous impermeable foam with a thickness of approximately 10-20 cm.

Another preferred embodiment consists of a gas-filled elastic material with a flexible tube welded along the longitudinal direction of the side, wherein the tube is filled with a predetermined gas pressure and the tube has a diameter of approximately 10-20 cm in thickness. Preferably, the tubes are arranged next to each other in succession, so as to completely cover the surface of the marine vessel to be protected.

The present invention also relates to a structure for protecting a structure against collisions of underwater shocks according to one of the aspects described above.

The invention will be explained with reference to the accompanying drawings, in which: FIG.

In the drawings, the same or corresponding parts bear the same reference numerals.

FIG. 1 is a diagram schematically showing a marine ship 1 exposed to an underwater explosion 2. During the explosion 2, a shock wave 3 (pressure wave) is generated while spreading radially in a sphere shape at a speed of sound in water. When the shock wave reaches the water surface 4, the shock is reflected in the opposite direction and conveyed to the reflected wave 5. Bulk-cavitation occurs, as a result of which the hollow bubbles 6 are formed.

The shock wave 3 is characterized by being moved stepwise in the water over the distance s. The movement size depends on the intensity of the explosion and the distance of the explosion. During the shock movement, the momentaneous peak pressure may be generated in steps of 100 bar or more.

When the shock wave reaches the marine ship 1, a part of the shock wave 3 is transmitted into the structure of the ship without using the protection means according to the invention. When a shock is delivered, the vessel is subjected to a very, very local accelerated shock load. As a result, the movement s in the ship will be approximately 6 cm, equivalent to the movement in water. As a result of the impact, the device on board the vessel is defective. Moreover, the shell of the ship is damaged, especially if it is made of a material that lacks malleability (the destroyer made of tempered glass fiber polyester or made of aluminum) and the ship is threatened.

According to the present invention, the shell 7 of the marine ship made of elastic, gas-filled plastic or rubber material is provided to be pressurized by a distance that is at least twice the width of the underwater movement for the shock wave. The compressibility that can be achieved with the use of gas-filled plastics or rubber materials is improved because of the presence of gas in the material, so the magnitude of the double impact movement is predetermined so as not to involve the risk of "bottoming". . In such a case, the material is impacted internally, causing high pressure inside the gas and the material.

On the other hand, because the structure has a relatively low density, the acoustic amplitude of the nearby water towards the plastic or rubber material shows intense discontinuity. In fact, the acoustic amplitude of a gas damper defined by the product density (ρ) and the speed of sound (nitrogen, oxygen, etc.) of gas (c) is less than the amplitude of water (ρc = 1,000 × 1,500 = 1,500,000). Amplitude (ρc = 1.25 x 330 = 412.5).

As a result, the damper plays the same role as air, but bulk-cavitation occurs due to the buffering action. At the position of the damper, the impact is reflected in the opposite direction and conveyed underwater like a reflected wave so that the impact is not transmitted into the ship.

Impact movement of water occurs about 6 ~ 12cm. This movement (foam or air layer) is absorbed into the shock damper without problems.

By using an impact damper with sufficient elastic path (more than 12 cm) and sufficiently small stiffness, the external force to be transmitted from the shell of the ship to the damper is greatly reduced.

2 schematically shows a cross section of a submarine 8. Around the submarine, an air chamber 9 is provided, in which the amount of gas (gas mass) in the chamber is controlled. For filling or discharging gas while the submersion depth is varied, the height of the air chamber can be kept substantially constant, while the chamber pressure remains the same as the actual ambient underwater pressure, depending on the submersion depth. The height of the chamber 9 is kept substantially constant, which is that the deeper the depth of the water, the more durable the impact durability is maintained and does not affect the buoyancy.

By means of the duct system 11, a gas-buffer member 10 is connected to the air chamber 9. A gas-buffered member that regulates the gas pressure and the gas volume of the chamber is connected to a gas container 12 containing a compressor or high pressure gas. In addition, the discharge valve can be used even at the maximum available pressure load.

3 is a view covering the ship's shell 14 with a flexible plastic hose or air mattress 13. The hose is welded along the lateral longitudinal direction and has a predetermined gas pressure. The hose has a diameter of about 12-20 cm. The hose 13 is hermetically sealed at one end and the other end is hermetically connected or sealed to a compressor or gas container (not shown).

Figure 4 shows a preferred embodiment of the protective structure against the generated underwater shock. The gas-filled elastic material is made of substantially uniform impermeable foam 15 to a thickness of approximately 10-20 cm. On the foam 15 for protection or resistance to low operational performance, a relatively thin and rigid plate 16 on the outer surface of the elastic material is provided, for example, in steel, aluminum, plastics. The thickness of the protective layer should be as thin as possible, preferably 10 mm or less.

The specific gravity of the elastic material has a specific gravity gradient according to the outer surface 17 having a relatively low specific gravity and the inner surface 18 having a relatively high specific gravity. The whole is attached to the steel ship shell 14, for example, by gluing or vulcanization.

FIG. 5 is a schematic illustration of a ship hull 14, such as the hull of a small warship or submarine, covered with a structure for protection against underwater shock according to the invention. The structure consists of a thin layer member 19 of, for example, a standard size of 1 m x 1 m. The thin layer member is provided in close proximity to the ship shell 14 by bolting, gluing and welding, or magnetic coupling (not shown). The magnetic coupling method, which magnetically attaches members to the ship's shell, provides temporary protection for the ship from underwater shocks.

The member consists of a foam layer 15 formed of rubber having a thickness of approximately 25 cm, covering both sides of a relatively thin and rigid plate 16 of steel, aluminum or fiberglass.

The invention is not limited to the preferred embodiment shown in the accompanying drawings, but all possible variations are possible. For example, in the protective structure, it can be made and used in combination with expansion members with foam rubber members, and can temporarily increase the impact resistance of the ship. Also in the protective member, the reinforcing portion can increase the magnetic regeneration ability of the member. It is noted that such modifications are possible within the scope of the appended claims.

Claims (11)

In a structure to be installed or operated on the water surface or in water having an elastic member formed on the outer surface of the structure located underwater and having a structure capable of protecting against underwater shock, The elastic member is at least spaced apart from the structure and is manufactured as a layer of elastic material having a gas-filled space on the side, and can be compressed to at least one water displacement amplitude range according to the underwater impact. Structure having an impact protection structure. The structure of claim 1, wherein the gas-filled space portion is connected to a gas-pressure regulator. 3. The structure of claim 2, wherein said space portion is connected to a gas buffer member. According to any one of claims 1 to 3, wherein the specific gravity of the elastic material has a gradient due to the specific gravity difference so as to have a relatively low specific gravity on the outside away from the structure, and a relatively high specific gravity on the inside. structure. The structure according to any one of claims 1 to 4, wherein the outer surface of the elastic material is provided with a relatively thin and rigid plate. The structure according to any one of claims 1 to 5, wherein the gas-filled elastic material is made of a homogeneous impermeable foam having a thickness of about 10-20 cm. 7. The gas filled elastic material according to any one of claims 1 to 6, wherein the gas-filled elastic material is made of a flexible tube filled with a predetermined gas pressure, welded along a longitudinal direction, and having a diameter of about 10 to 20 cm. Structure made with. A structure characterized in that it is possible to protect the structure according to any one of claims 1 to 7 against underwater shock. 9. A structure according to claim 8, wherein a relatively thin and rigid plate is arranged externally and formed of a thin plate of substantially homogeneous impermeable foam. 9. A structure according to claim 8, wherein a relatively thin and rigid plate is arranged externally and consists of a continuous layer of air pressurized hose or an air mattress. The structure according to any one of claims 8 to 10, wherein the structure is provided to the structure by welding, bolting, adhesive bonding, or magnetic bonding.