JPH0723675B2 - Underwater machinery pressure balance device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pressure balancing device for an underwater machine, and more particularly to a mechanism for balancing internal and external pressures of a seal of an underwater machine such as an underwater excavator used underwater. The present invention relates to a pressure balance device for an underwater machine that prevents sand and muddy water from entering the sea.

[Conventional technology]

Generally, when excavating a circular hole or the like in the ground, as the excavation depth increases, the groundwater pressure rises, and the hole wall of the excavation hole may be collapsed. Therefore, at the time of excavation, excavation is performed in a state where the hole is filled with water and hydrostatic pressure is applied to the hole wall. Further, the earth and sand generated during excavation are discharged to the ground by circulating muddy water in the excavation hole. Therefore, since water head pressure is constantly applied to the excavator body, the joints such as the casing that configure the excavator body and the shaft sealing portion between the bit and the casing are sealed to prevent water from entering the mechanism. It is designed to prevent the entry of sand and sand. However, since the head pressure directly acts on such a seal, the pressure difference between the inside and the outside of the seal becomes large, and the durability of the seal is unavoidably reduced.

Therefore, conventionally, a balance device described in Japanese Patent Publication No. 51-17321 has been proposed. According to the publication, a lubricating oil (operating oil) filled in a hermetically sealed casing is introduced into a balance device having a diaphragm or a piston, and the diaphragm is expanded or contracted by utilizing the hydraulic head pressure in the drill hole. Is moved and the same pressure as the hydraulic head pressure is applied to the lubricating oil in the transmission by the balance device to balance the hydraulic head pressure in the drill hole and prevent the pressure difference from acting on the seal. . Further, Japanese Utility Model Publication No. 56-37030 and Japanese Patent Publication No. 62-40506 disclose pressure balance devices having the same principle.

[Problems to be Solved by the Invention]

However, the former piston type balancer disclosed in Japanese Patent Publication No. 51-17321 has a drawback that slurry such as sand is deposited on the sliding portion of the piston, causing malfunction of the piston. Further, the diaphragm type balance device has a limited expansion and contraction amount, and since air and the like are often mixed in, a change in the hydraulic head pressure cannot be sufficiently reflected in the hydraulic oil in the casing. Further, the balance device of Japanese Utility Model Publication No. 56-37030 uses a metal bellows coated with a rubber bag as a pressure adjusting device, but fresh water is put in the rubber bag to avoid direct contact of muddy water with the bellows. This prevents the slurry from biting into the bellows bellows and causing a malfunction, but the resistance is large and the pressure change cannot be swiftly followed. In addition, the balance device described in Japanese Patent Publication No. 62-40506 also uses a bellows-shaped diaphragm, so that the slurry is bitten in as in the case of Japanese Utility Model Publication No. 56-37030, resulting in defective operation.

The above-mentioned various pressure balance devices move in the axial direction and change, and since the slurry slides in a state where the slurry is easily bited, it has a defect that it is liable to malfunction and is easily damaged.

In addition, the underwater excavator is large and expensive, and if the balancer is defective, muddy water is mixed in, which causes great damage due to replacement and disassembly.

Further, the balance device has a casing filled with a liquid such as lubricating oil (operating oil) in order to balance the external pressure such as head pressure and the pressure applied to the casing of the underwater excavator body. It is impossible to completely remove the air from the casing because air is mixed into the lubricating oil itself at the time of refueling and the air reservoir cannot be completely eliminated from the internal structure. Therefore, in order for the balance device to work effectively, it is necessary to be able to deal with the volume change in consideration of contraction and expansion due to air.

The present invention has been made in view of such circumstances, and it is possible to quickly respond to the change in the head pressure generated in the submersible machine body, and the volume thereof is large, so that a malfunction due to the deposition of slurry such as sand does not occur. An object is to provide a pressure balance device for an underwater machine.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention provides a pressure balance device for an underwater machine, which balances the head pressure received by the underwater machine and the pressure of the hydraulic oil in the underwater machine body. The expansion / contraction bag made of rubber that allows the working oil to come in and out freely and can be contracted and expanded, and the expansion / contraction bag are housed, and has a communication hole at one end for communicating the inside of the submersible machine body with the expansion / contraction bag, and the other end. An outer cylinder having an opening for receiving a water head pressure, and a through hole which is attached to a communication hole of the outer cylinder to limit the contraction amount of the expansion / contraction bag, and through which the working oil inside the main body enters and leaves the expansion / contraction bag. And a stopper member that is provided at the end of the expansion / contraction bag and that restricts the expansion amount of the expansion / contraction bag by contacting the edge of the opening of the outer cylinder when the expansion / contraction bag is expanded. It has a feature.

[Action]

According to the present invention, the expansion / contraction bag capable of moving in and out the hydraulic oil filled in the underwater machine body is housed inside the outer cylinder having the opening for allowing water to flow in at one end, and At the time of use, the expansion / contraction bag is expanded or contracted by the head pressure of water flowing into the outer cylinder from the opening. By expanding or contracting the expansion / contraction bag, the pressure of the hydraulic oil filled in the submersible machine body is balanced with the head pressure. That is, when the submersible machine is inserted into water and the pressure of the hydraulic oil in the casing is lower than the water head pressure, the expansion / contraction bag contracts in response to the head pressure, causing the hydraulic oil to flow into the main body from the expansion / contraction bag. Then, the pressure of the hydraulic oil in the main body casing is increased, and a pressure equal to the head pressure is applied to the main body casing and the seal portion.
Further, when the pressure of the hydraulic oil becomes higher than the hydraulic head pressure due to thermal expansion or the like, the expansion / contraction bag expands, and the hydraulic oil flows into the expansion / contraction bag to reduce the pressure to balance the hydraulic head pressure. As a result, the pressure difference between the hydraulic oil pressure inside the submersible machine body and the head pressure is eliminated, and the internal (working oil) and external (head pressure) pressures acting on the seal portion of the submersible machine body can be balanced. . Further, since the expansion / contraction bag expands and contracts like a balloon, the malfunction does not occur due to the sliding of the sand between the expansion / contraction bag and the outer cylinder. Further, since the expansion / contraction bag is made of rubber, it can be quickly expanded and contracted in response to changes in head pressure, and can immediately respond to changes in pressure.

〔Example〕

Hereinafter, preferred embodiments of a pressure balance device for an underwater machine according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an explanatory view showing a case of excavating using an underwater excavator having a pressure balance device according to the present invention.
As shown in FIG. 1, a crane 10 (only part of which is shown), a reaction force receiving device 12, a cable reel 14, a suction pump 16 and the like are installed on the ground, and the crane 10 is underwater excavated via a wire 18. Machine 20 is suspended. A cable 22 for supplying electric power to the excavator 20 is wound around the cable reel 14, and electric power is supplied to the excavator 20. Further, the excavator 20 is provided with a reverse pipe 24 for discharging earth and sand generated by excavation to the ground. The reaction force receiving device 12 supports a reaction generated in the excavator 20 by excavation via a reverse pipe 24. Further, the pressure balance device 38 according to the present invention is attached to the excavator 20 as shown in FIG. 1, and protects the seal of the rotary shaft portion of the excavator 20 main body from the water pressure in the excavation hole 26 by the action described later.

FIG. 2 is a front view showing the excavator 20 of FIG. 1, and FIG. 3 is a sectional view of the pressure balance device 38 according to the present invention. As shown in FIG. 2, the excavator 20 mainly includes a fixed casing 28, an orbiting casing 30, and expanded hole casings 32A, 32B and 32C. Each casing is composed of transmission mechanism parts such as gears and communicates with each other, and the inside thereof is filled with hydraulic oil. 2 and 3, pressure balance devices 38, 38 are mounted above the fixed casing 28, and the expansion / contraction bag 46 of the pressure balance devices 38, 38 is connected to the fixed casing 28 via a hose 52. . The hydraulic oil filled in the casing communicates with the inside of the expansion / contraction bag 46 via the hose 52.

Further, as shown in FIG. 2, the submersible motors 34, 34 and the fixed guides 36, 36 are attached to the upper portion of the fixed casing 28. A wing bit is provided at the bottom of the revolution casing 30.
42A, 42B and pilot bit 42C are attached to a drive shaft (not shown), respectively. The fixed casing 28 and the revolution casing 30 are joined via a seal in order to prevent infiltration of muddy water or the like into the casing. Further, the driving force of the submersible motors 34, 34 is provided in each casing with the bits 42A, 42B,
A power transmission mechanism for transmitting to 42C is built in together with the hydraulic oil for lubrication.

Next, the pressure balance device 38 will be described mainly with reference to FIG. The pressure balance device 38 mainly includes an outer cylinder 44 and an expansion / contraction bag 46. The expansion / contraction bag 46 is capable of contracting and expanding as shown in FIG. 3 when it is filled with lubricating oil. An opening 44A is formed at the bottom of the outer cylinder 44, and muddy water or the like can freely enter and leave the outer cylinder 44 through the opening 44A. Also, the upper portion 44B of the outer cylinder 44
The bladder cap 45 is screwed into the
The upper and lower sides of the rubber expansion / contraction bag 46 are clamped and fixed by
46 is stored and supported in the outer cylinder 44. A stopper 49 (stopper member) is attached to the lower end of the expansion / contraction bag 46 to prevent the expansion / contraction bag 46 from protruding from the opening 44A by hitting the stopper surface of the opening 44A when the expansion / contraction bag 46 is excessively expanded. .

A bladder mask 47 (mask) having a through hole 47A is fitted into the bladder cap 45, a cap 48 is screwed to the upper end of the bladder cap 45, and a stopper plug is attached to the upper part by an air bleeding plug 50. Has been done. Further, the fixed casing 28 and the expansion / contraction bag are provided on the side surface of the cap 48.
A piping hose 52 connecting with 48 is attached. The hydraulic oil sealed in the casings 28, 30, 32A, 32B, and 32C passes through the piping hose 52 and the cap 48, and enters and leaves the expansion / contraction bag 48 through the through hole 47A of the bladder mask 47. The bladder mask 47 also has a function of preventing the expansion / contraction bag 46 from entering the cap 48 when the expansion / contraction bag 46 is excessively contracted as shown by the alternate long and short dash line in FIG.

The operation of the pressure balancing device for an underwater machine according to the present invention configured as described above is as follows. At the time of excavation, as shown in FIG. 1, the excavation hole 26 is filled with a certain amount of water in order to prevent the side wall of the excavation hole 26 from collapsing. Therefore, the third
In the illustrated pressure balance device 38, water pressure is constantly acting from the opening 44A into the outer cylinder 44 during excavation, and the expansion / contraction bag 46 expands and contracts in proportion to the magnitude of the water pressure. In this case, if the hydraulic oil is completely filled and the compressed fluid such as air is not mixed in the casing, the expansion / contraction does not occur. Expansion bag
When 46 is contracted by the head pressure, the hydraulic oil in the expansion / contraction bag 46 is transferred to the casings 28, 30, 32A, 32B and 32C by the bladder mask 4
7. Flow through the piping hose 52. Then, due to the inflow of the hydraulic oil, the pressure in the casing rises to almost the same pressure as the hydraulic head pressure in the excavation hole 26, and the pressure difference between the pressure in the casing and the hydraulic head pressure in the excavation hole 26 disappears. Therefore, the pressure difference does not work on the seal of the shaft sealing portion of the casing, and the seal is protected. Further, when the pressure in the casing increases due to a decrease in head pressure or a rise in the temperature of the hydraulic oil, the hydraulic oil in the casing flows into the expansion / contraction bag 46 and expands / contracts in the opposite manner to the case of contraction. The bag 46 expands like a balloon to balance the hydraulic oil pressure with the hydraulic head pressure. As described above, the durability of the seal is improved by eliminating the pressure difference between the hydraulic oil pressure and the hydraulic head pressure.

Further, since the expansion / contraction bag 46 is made of rubber, the expansion / contraction bag 46 can be quickly contracted and expanded in response to a rapid change in the head pressure in the drill hole 26 and an increase in the pressure of the hydraulic oil in the casing, and the pressure in the casing is reduced. Instantly balance the internal head pressure. In addition, it does not cause malfunctions due to earth and sand,
Since only the replacement of the expansion / contraction bag 46 is required for the maintenance, the maintenance can be efficiently performed in a short time.

The present invention is not limited to the above-described embodiment, and can be used for an underwater excavating machine such as a continuous wall excavator or a mechanical device such as an underwater pump that is used in water and receives a head pressure.

〔The invention's effect〕

As described above, according to the pressure balance device of the present invention, the expansion and contraction bag made of rubber is installed in the outer cylinder, and the expansion and contraction of the expansion and contraction bag controls the pressure of the hydraulic oil in the submersible machine body, and Balanced with pressure. Therefore, the joint portion and the seal portion of the casing can be protected from the head pressure. Furthermore, troubles such as malfunctions due to sliding with the outer cylinder can be prevented.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a case of excavating using an excavator having a pressure balance device for an underwater machine according to the present invention,
2 is a front view showing a main part of the excavator shown in FIG. 1,
FIG. 3 is a sectional view of a pressure balance device according to the present invention. 20 ... Excavator, 26 ... Drilling hole, 28 ... Fixed casing, 38 ... Pressure balancing device, 44 ... Outer cylinder, 44A ... Opening part, 44B ... Communication hole, 46 ... Expansion / contraction bag, 47 ... Bladder mask (mask), 47A …
Through hole, 49 ... Stopper (stopper member).

Claims (1)

[Claims] Claim: What is claimed is: 1. A pressure balance device for an underwater machine, wherein the hydraulic head pressure received by the underwater machine and the pressure of the hydraulic oil in the underwater machine body are balanced. A flexible expansion / contraction bag made of rubber that can be freely contracted and expanded, and an opening for accommodating the expansion / contraction bag, having a communication hole at one end for communicating the inside of the submersible machine body with the expansion / contraction bag, and receiving water head pressure at the other end. An outer cylinder having a portion, a mask having a through hole that is attached to a communication hole of the outer cylinder to limit the amount of contraction of the expansion and contraction bag, and the working oil inside the main body enters and leaves the expansion and contraction bag; A stopper member that is provided at an end of the expansion / contraction bag and limits the expansion amount of the expansion / contraction bag by contacting the edge of the opening of the outer cylinder when the expansion / contraction bag is expanded. Pressure balance device.