JPS5811356B2 - Drainage buoyancy generator for semi-submerged ships - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention makes it possible to quickly deal with a problem in the trim of a semi-submerged ship while it is traveling at extremely low speed or at anchor, and also to improve the floating height of the ship. This invention relates to a device that adds or reduces drainage buoyancy to a semi-submerged ship so that it can be quickly adjusted.

A semi-submersible ship has a lower hull that accounts for the main part of its displacement and is located below the water surface, an upper hull that is located above the water surface and is used for passengers, cargo, a work platform, etc.; This hull structure, in which the hull is composed of supports connected through the hull, has many features such as good maneuverability in waves, but the submerged parts of the hull, especially the supports, are The cross-sectional area is kept to the minimum required in order to reduce the influence of water and sailing resistance as much as possible, so when the hull tilts, the change in buoyancy distribution that occurs is smaller than that of a normal monohull ship. In other words, the static restoring force due to buoyancy is extremely small, so an unbalanced load within the ship tends to cause a very large inclination relative to the size of the load.

This tendency shows that when a ship is sailing at a certain speed or higher,
By changing the attitude of the lower hull or by providing fins, it is possible to easily cope with the tilting of the hull by utilizing the large dynamic acting force generated on the hydrofoil surface, but this acting force is caused by the interaction between the hull and the water. It decreases in proportion to the square of the relative speed during the period, so it cannot be expected to have any effect when the ship is at very slow speed or at rest.

As a countermeasure for this, conventional ships have trim tanks installed at several locations in the lower hull, and the movement of water in these trim tanks compensates for the inclination of the ship when it is traveling at extremely low speed or when it is at anchor. Was.

However, since the practical permissible flow rate of water is small, its flow capacity becomes a limiting factor, limiting the speed at which water can move from one trim tank to another, resulting in a delay in compensation for the inclination of the hull. was there.

Therefore, for example, when passengers move on or off the ship to board or disembark the ship, it is difficult to cope with the rapid and irregular changes in the load on the ship that occur due to the movement of water in the trim tank. A countermeasure was desired.

Therefore, the present invention has been made to provide a semi-submerged ship that can quickly cope with the tilting of the ship due to changes in the ship's internal load while the ship is stopped. Focusing on the generality of a gas body that has a practical allowable flow velocity value (typical value 20 m15 ec) that is about 10 times that of Drainage buoyancy is achieved by attaching highly elastic or flexible liquid-tight and air-tight air bags to supporting parts below the line or at appropriate locations on the lower hull, and by freely filling and discharging gas into these air bags. This device provides semi-submerged ships with the ability to quickly adjust hull trim and buoyancy, which is not possible with conventional water tank adjustment methods.

Examples will be described below with reference to the drawings.

As shown in FIG. 1, a semi-submersible ship, for example a catamaran semi-submersible ship, has an upper hull 1 located above the water line A and a circular cross section of the vessel which generates most of the displacement buoyancy. The torpedo-shaped port lower hull 2 and starboard lower hull 3 are supported by front and rear support parts 4, 5, which penetrate the water line A and also serve as vertical fins.
Connect according to 6.7.

On the stern side of the lower hulls 2, 3, propellers 8, 9 are provided which are driven by a prime mover (not shown) installed at a suitable position in the hull element via a transmission device (not shown), and behind them are propellers 8, 9. Wing surfaces 10, 11 used as longitudinal rudders are arranged.

Furthermore, horizontal wing surfaces 12, 13, 14, and 15 are attached to the inner positions of the lower bodies 2 and 3, and can be moved appropriately depending on the structure, in part or as a whole as a horizontal control surface. Maneuvering and attitude control are performed while the ship is sailing.

Appropriate position below the water line A of such a semi-submerged ship.

For example, a device 16 for generating or adding drainage buoyancy is provided at the rear end of each support portion 4, 5, 6, 7.

FIG. 2 shows a first embodiment of this drainage buoyancy generating device.
The flange 19b of the support member 19 having a tubular shape and an internal hole 19a and the flange 20a of the opening of the air bag 20 are attached to the flange 18a of the mounting base 18 in an integral or assembled manner. 22, Natsu 23
etc., and on the other hand, a supply pipe 24 and a discharge pipe 25 which communicate with the opening of the support member 19 in the internal space B of the support part 4 are connected.

The air bag 20 is made of a flexible, liquid-tight, and air-tight material, and expands when gas is filled inside and contracts when the gas is discharged to keep the volume as small as possible and travel along the support member 19. The supply pipe 24, which is made to have low resistance, passes through the internal hole 19a of the support member 19 and connects to the air bladder 2.
The other end of the supply pipe 24 is connected to a pressurized gas supply source (not shown), such as a gas compressor, a gas holder, a cylinder, or a combination of these, installed at a suitable location on the ship. The air bladder 20 is filled from the supply pipe 24 under the control of a pressurized gas cannon from a supply source, which is connected via other necessary control devices (not shown).

On the other hand, the exhaust pipe 25 also communicates with the inside of the air bag 20 through the internal hole 19a of the support member 19, and the other end is connected through an exhaust valve (not shown) that controls the flow rate of exhaust gas and other matters.
Depending on the hull structure, the gas inside the air bag 20 is communicated with the outside air, at a suitable location inside the ship, or to a gas recovery system, and the gas inside the air bag 20 is appropriately released or recovered while being controlled by a discharge valve.

The supply pipe 24 and the discharge pipe 25 can also serve as both with the aid of suitably configured valves and side pipes.

Alternatively, if the pressurized gas is compressed air and there is no problem in discharging it into the internal space B of the support part 4, the discharge valve can be mounted directly on the mounting base 18, and the discharge pipe 25
may be omitted.

Next, the action will be explained.

If pressurized gas is supplied into the air sac 20 from the supply pipe 24, the air sac 20 will expand (as shown by the two-dot chain line in FIG. 2), and if the gas in the air sac 20 is discharged from the discharge pipe 25, the air sac 20 will expand Shrink.

Therefore, if the air sac 20 is filled with an appropriate amount of gas at an appropriate pressure and the air sac 20 is appropriately inflated, drainage buoyancy corresponding to the volume of the air sac 20 will be generated.

Therefore, by installing an appropriate number of drainage buoyancy generators 16 including such air bladders 20 at appropriate positions on the ship's hull below the waterline A, and adjusting the amount of gas filled in each air bladder 20, the attitude of the ship can be quickly adjusted. Can be controlled and adjusted.

In this case, in addition to the attitude of the hull and the floating height, a detector (not shown) detects the gas pressure in each air bladder as necessary, and according to these detection signals, further Through a system that combines and processes these detection signals, pressurized gas from a gas supply source is introduced into or discharged from each air sac to control the expansion level of each air sac to an appropriate level. Since additional discharge buoyancy can be distributed on the hull, these buoyancy values and the distribution of buoyancy at the practical inflation limit of the bladder allow the hull attitude to be adjusted automatically and quickly, even at slow speeds or at rest. 3 to 5 show a second embodiment of the drainage buoyancy generating device. Internal holes 26a, 2 for
6b is fixed, and the opening of the air bladder 27 is fastened and fixed to this support plate 26 in a liquid-tight and airtight manner using a fixture 28, and a supply pipe 24 and a discharge pipe are connected to the internal holes 26a and 26b, respectively. 25 are connected to constitute a drainage buoyancy generating device 29.

The air sac 27 is formed of a material such as rubber-coated cloth that has deformability and appropriate elasticity to withstand folding, and maintains the folded state in, for example, a bellows shape (Fig. 5) to exhibit a regular shape with low sailing resistance. Do it like this.

At this time, if the appropriate location of the air sac 27 and the appropriate location of the support plate 26 are connected with a string 30 having appropriate elasticity and tensile strength,
The air bag 27 can be automatically maintained in a well-folded state with low running resistance.

When this air bladder 27 is filled with pressurized gas, the air bladder 27 expands and generates drainage buoyancy, as shown by the two-dot chain line in FIG. 3 and FIG. 4.

Note that the drainage buoyancy generating device 16 according to the first embodiment and the drainage buoyancy generating device 29 according to the second embodiment may be used together and mounted at appropriate positions on the hull.

According to the above-mentioned displacement buoyancy generating device for a semi-submerged ship of the present invention, it is difficult to control the buoyancy of the ship due to the unbalance of cargo movement inside the ship during very fine navigation or while stopped, which was difficult to control in the conventional semi-submerged ship. By using a gas body with a large practical allowable flow velocity value, it is possible to easily control and adjust changes in the attitude of the drain, and as a medium that generates drainage buoyancy, in the supply and discharge passages that are the bottleneck in the flow. , it is possible to control the attitude of the ship extremely quickly, and therefore it is possible to sufficiently respond to changes in the attitude of the ship due to rapid and irregular load fluctuations during extremely slow movement or while stopped.

Furthermore, it is also within the technical scope of the present invention to use the drainage buoyancy generating device using gas according to the present invention in combination with a conventional hull attitude adjustment device that performs water injection into the hull water tank. By using them in combination, even greater practicality and economic efficiency can be achieved.

In addition, the air bladder of the present invention is made of a material such as rubber-coated cloth that has deformability and appropriate elasticity that can withstand folding, and is maintained in a folded state in a bellows shape, so that the sailing resistance can be significantly reduced. Therefore, there is an effect that the running stability can be increased.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Fig. 1 is an overall perspective view of a twin-hulled semi-submersible ship seen from diagonally below, and Fig. 2 is a longitudinal sectional view showing a first embodiment of a drainage buoyancy generating device. Fig. 3 is a longitudinal cross-sectional view of the second embodiment of the drainage buoyancy generating device, Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3 showing the air sac in an expanded state, and Fig. 5 is a folded state of the air sac. FIG. 4 is a side sectional view taken along the line V-V in FIG. 3; 1... Upper hull, 2, 3... Lower hull, 4, 5, 6
゜7...Support part, 16.29...Drainage buoyancy generator, 18...Mounting base, 19...Support member, 20, 27
... Air sac, 24... Gas supply pipe, 25... Gas discharge pipe, 26... Support plate, 30... Strap.

Claims (1)

[Claims] 1. In a semi-submerged ship in which the upper hull located above the waterline and the lower hull located below the waterline are connected by a support part and the support part penetrates the waterline, the above-mentioned support below the waterline At least one foldable, flexible, liquid-tight and air-tight air bladder is installed at an appropriate position on the lower hull or the lower hull, and a detector detects the attitude of the hull and the floating height, and gas is supplied into the air bladder. , and a drainage buoyancy generating device for a semi-submerged ship, characterized in that the drainage is controlled freely.