JPS5830793Y2 - Sway reduction device using the hull structure - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the invention of a rocking reduction device that utilizes a ship's hull structure, and aims to obtain a favorable rocking reduction effect by using a top side tank as an anti-rolling tank.

It has been generally known to employ an anti-rolling tank for the purpose of reducing the rocking of a ship's hull due to waves and the like.

However, this conventional anti-rolling tank is installed between the lower sides of the hull, and the waterway that connects the wing tanks on both sides is of a U-shape formed near the bottom of the ship, and is located inside the hull. The disadvantage is that it requires considerable installation space.

Furthermore, it is common for such hulls to have a separate topside tank, and it appears that some consideration has been given to using such a topside tank as a sway reduction mechanism. If you try to use this topside tank as an anti-rolling tank, a waterway will be formed in the middle of the hull, which will be extremely inconvenient for the ship's use, and if the waterway is formed near the bottom of the ship, the pipe will become long, making the waterway of a given cross-sectional area longer. Doing so would reduce the usable space inside the ship, which would be disadvantageous in terms of its structure and the collapse of the usable space.

The present invention was devised after repeated studies in view of the above-mentioned circumstances, and it connects the upper parts of the top side tanks installed oppositely on both sides of the hull by a waterway using the underside of the deck. The air bags are respectively secured to the lower part of the air bag, and these air bags are connected by an air pipe.

That is, to explain the specific embodiment of the invention according to the present invention as shown in the accompanying drawings, a hold 7 is appropriately arranged in the center of the hull 8, and (In the illustration, only one side is partially shown, but a similar relationship is formed symmetrically on both sides of the center line 9.)
As shown in Figures 1 and 2, these topside tanks 1 and 1 are connected at their upper parts by a waterway 2 that is also formed along the lower surface of the deck 10. has been done.

Further, an air bag 3 is provided at the lower part of the top side tanks 1, 1, and the air bag 3 is made of anti-floating material 5, preferably having some elasticity or deformability, such as a net or a string. It is attached to the bottom of the tank 1 by means of a locking ear provided on the circumference of the air bag 3 itself and a hook provided on the inner surface of the bottom of the tank. The provided air bags 3 are also connected to each other by an air pipe 4, and the air pipe 4 is arranged along a bulkhead member 6, which is a hull structural member, in the second and third sections.
As shown in the figure.

That is, to further explain the device according to the present invention, it is clear that in the case where the upper parts are connected by the waterway 2 as described above, an inverted U-shaped tank space is formed between both sides of the hull. , oil, seawater, or other liquid is injected into the tank as a working fluid.

The amount of working fluid to be injected is such that a certain amount of space is formed above the tank 1.1 and water channel 2 without completely filling them, so that the working fluid can mutually interact between the side tanks 1.1 and 1 during rocking. Allow it to flow.

For example, the top side tank 1 as described above has a narrow bottom in vertical section due to the structure of the hull 8, and normally has an inverted right triangular shape as shown in FIG. When air bags 3 as shown in Fig. 2 are set at the bottom, a space equivalent to 31 air bags is left above each tank 1 and waterway 2 under conditions where the ship does not rock. The amount should be about the same amount.

This amount of working fluid is such that when compressed air is injected into the air bag 3 after injecting the working fluid into the tank, the compressed air in the bag will move the air bag 3 under pressure balance conditions with the working fluid. Since the amount is enormous, it can be easily obtained practically.

It is clear that when the hull 8 of a vessel installed as described above rocks, it will topple over or the working fluid in one of the upper tanks 1 will flow into the other lower tank through the waterway 2. The fact that the upper and lower relationships between the side tanks 1 and 1 are alternately switched and reversed is the same as in a general U-shaped anti-sway tank;
In such a case, the upper area of the lower tank and the middle part of the waterway 2 are generally filled with the working fluid. The liquid pressure due to the head difference from the free liquid level (this free liquid level is inclined with respect to the cross section of the water channel 2) acts on the air bag 3, and therefore the air in the air bag 3 in the lower tank increases in pressure ( (in terms of volume), the air is transferred to the air bladder in the upper tank via the air pipe 4.

That is, as described above, a larger amount of working fluid can be received in the lower tank by the air bag in the solder lower tank, and on the other hand, as described above, the working fluid flows out toward the lower tank and the liquid pressure decreases. Furthermore, in the upper tank whose bottom air bladder is pressurized with gas, the working fluid is more effectively sent toward the lower tank.

The cross-section of the top side tank 1 is arranged in an inverted right-angled triangular shape with the outer side at a right angle, as shown in FIG. 2, and the upper air bag (and lower air bag) as described above. Coupled with the action of , most of the working fluid in the upper top side tank 1 flows out and becomes empty, and according to the well-known calculation formula for determining the natural period T of the vibration reduction tank. By employing selected water depths and cross-sectional areas of the tank and duct (channel 2), an extremely efficient vibration reduction effect can be achieved.

It is clear that according to the present invention as explained above, an anti-rolling tank is formed using the top side tank, that is, a rolling reduction mechanism using the hull structure itself is obtained, and the hydraulic pressure of the flowing working fluid is By using the air bag to expand and contract, it was possible to achieve an efficient vibration reduction effect that made it possible to empty the top side tank, which was located on the upper side during rocking, and furthermore, to make it possible to empty the top side tank that was located on the upper side during rocking The waterway uses the underside of the deck, and the air pipe that connects the air bags can have a fairly small diameter because the volume of the air passing through it decreases under pressure conditions, and it can also be attached to the bulkhead surface. This is a highly effective design in practical terms, as it has the advantage of virtually no hindrance to the utilization of space inside the ship.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and Fig. 1 is a plan view of a part of the hull equipped with the anti-sway device of the present invention, and Fig. 2 is a cross section taken along the line ■... in Fig. 1. Figure 3 is a sectional view taken along line 2 in Figure 2. However, in these drawings, 1 is the top side tank, 2 is the waterway, 3 is the air bag, 4 is the air pipe, 8 is the hull,
10 indicates the deck, respectively.

Claims (1)

[Scope of utility model registration request] The upper parts of the top side tanks installed opposite to each other on both sides of the ship's hull are connected by a waterway using the underside of the deck, and the lower parts of the top side tanks are each connected with an air bag, and these air bags are connected by an air pipe. A sway reduction device that utilizes the ship's hull structure.