JPH106975A - Reference draft adjusting type air cushion ship - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a leakage of air from around an air cushion room by increasing a reference degree of opening as a neutral point of a duct open and close device when there are waves to reduce a standard value of internal pressure of the air cushion room and deepening reference draft of a hull of a ship when the sea is rough and there are waves. SOLUTION: A reference degree of opening of a flap 7 is changed in such a manner that it is increased than a reference degree of opening at usual time so that a standard value of internal pressure is reduced in accordance with the height of waves to deepen reference draft based on signals detected by a wave height sensor when the sea is rough. Moreover, when a degree of opening of the flap 7 is changed to increase a degree of opening of a duct 6 and internal pressure of an air cushion room 3 is reduced, a characteristic curve is changed, and volume of air which flows by a lift fan 2 is increased. Consequently, volume of emission of air is compensated when volume of air which is emitted in the atmospheric air through the duct 6 is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air cushion ship, and more particularly, to a reference draft adjusting type air cushion ship capable of changing its reference draft according to outboard waves.

[0002]

2. Description of the Related Art In a conventional air cushion ship, as shown in FIG. 7 (transverse sectional view), a hull 1 is surrounded by left and right hull side walls 1a and a bow seal and a stern seal (not shown). A cushion chamber 3 is provided at the bottom of the ship, and a lift fan 2 for sending pressurized air to the air cushion chamber 3 is provided.

[0003] When the lift fan 2 is stopped, the hull 1 floats with a deep draft d in order to support its entire weight by buoyancy. Then, during sailing, the pressure in the air cushion chamber 3 is increased to P by the lift fan 2, so that a part of the total weight of the hull is supported by this pressure P and the remaining weight is supported by buoyancy. Therefore, Kissui is decreased in the operating state of the lift fan 2, Kissui the hull outer d _0, Kissui the hull inside the d _i.

As described above, in the conventional air cushion ship,
By reducing the draft, the water resistance of the hull is reduced, enabling high-speed cruising. In recent construction ships, a duct 4 communicating from the air cushion chamber 3 to the atmosphere and a duct 4 for the purpose of alleviating the hull acceleration caused by the fluctuation of the pressure P in the air cushion chamber 3 due to the influence of waves. There is also a louver 5 having a variable opening degree capable of opening and closing the opening 4 variably. In such an air cushion ship, a louver based on a detection signal from an internal pressure sensor for detecting an internal pressure of the air cushion chamber 3 is provided. By changing the opening degree of 5, the control for reducing the fluctuation of the internal pressure P of the air cushion chamber is performed.

[0005]

However, in the conventional air cushion ship as described above, although the draft is reduced by the internal pressure of the air cushion chamber 3, high speed cruising becomes possible. Due to shallow air intake from the seawater intake for water jet propulsion provided at the bottom of the ship, making sailing difficult, and problems such as air leaking from around the air cushion chamber 3 I have

In order to solve the above-mentioned problems, it is necessary to lower the internal pressure of the air cushion chamber 3 during a wave to deepen the draft of the hull. As a means for adjusting, it is conceivable to change the rotation speed of the lift fan 2. For example, when reducing the rotational speed of the lift fans 2 in order to lower the internal pressure, the pressure of the lift fan - flow characteristics, as shown in FIG. 6, proceeds from a to b, the internal pressure from P ₁ to P ₂ down, but will be at the same time decrease the flow rate from Q ₁ to Q _2.

On the other hand, the reason for lowering the internal pressure is that air leaks from the air cushion chamber 3 in the waves during stormy weather, and a large flow rate is required. Is a problem.

The present invention is intended to solve such a problem. When the wave height is high in stormy weather, the reference opening of the duct communicating from the air cushion chamber to the atmosphere is determined based on the detection signal of the wave height sensor. By changing the air cushion, the internal pressure of the air cushion chamber is lowered and the standard draft is deepened, so that the suction of water jets and air leakage from around the air cushion chamber can be minimized. The task is to provide ships.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a reference draft-adjustable air cushion ship of the present invention is provided with an air cushion chamber which is surrounded by left and right hull side walls, a bow seal and a stern seal, and is opened downward. An air cushion ship equipped with a lift fan for reducing the draft of the hull by sending pressurized air to the air cushion chamber and a duct communicating from the air cushion chamber to the atmosphere; and And a pressure sensor for detecting the internal pressure of the air cushion chamber, and a wave height for the wave outside the boat, in addition to an opening / closing device capable of opening and closing the duct, and a duct opening adjustment mechanism for adjusting the opening of the duct opening / closing device. The standard opening of the duct opening / closing device, which has a wave height sensor and can maintain the standard value of the internal pressure corresponding to the standard draft when sailing, is set to the neutral point. And a first control system that sends an opening control signal to the duct opening adjustment mechanism to increase or decrease the opening of the duct based on a detection signal from the pressure sensor, and based on a detection signal from the wave height sensor. A second control system for sending a reference opening control signal for changing the neutral point to the duct opening adjustment mechanism to change the reference draft is provided.

In the above-mentioned reference draft-adjustable air cushion ship of the present invention, the first control system uses the reference opening degree of the duct opening / closing device that can open and close the duct communicating from the air cushion chamber to the atmosphere (the reference value during sailing). (Corresponding to drafting) as a neutral point,
Based on a detection signal from a pressure sensor capable of detecting the internal pressure of the air cushion chamber, a control signal is sent to a duct opening adjustment mechanism to increase or decrease the opening of the duct. The control system 2 sends a reference opening control signal to the duct opening adjustment mechanism based on the detection signal from the wave height sensor to perform an operation of changing the neutral point, that is, an operation of changing the reference draft.

[0011] In the reference draft adjustable air cushion ship of the present invention, the pressure drop in the duct is increased by changing the neutral point during a wave or the like and the internal pressure of the air cushion chamber is reduced, so that the internal pressure decreases. In this case, the air flow rate by the lift fan increases.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a hull showing a reference draft adjusting type air cushion ship as one embodiment of the present invention. FIG. 3 is an enlarged view showing a modification of the main part, FIG. 3 is an enlarged view showing another modification of the main part corresponding to FIG. 2, and FIG. 4 is another main part of the air cushion ship. FIG. 5 is a control block diagram showing an example of a control system in the air cushion ship of the present invention,
FIG. 6 is a graph for explaining the control characteristics of the air cushion ship of the present invention.

First, as shown in FIG. 1, this standard draft-adjustable air cushion ship also has an air cushion which is opened downward by being surrounded by left and right hull side walls 1a and bow seals and stern seals (not shown) as in the prior art. A chamber 3 is provided at the bottom of the vessel, and a lift fan 2 for sending pressurized air to the air cushion chamber 3 to reduce draft of the hull is provided.

The air cushion ship of this embodiment has a duct 6 communicating from the air cushion chamber 3 to the atmosphere,
Rotary flap 7 as a duct opening and closing device that can open and close the door
And a duct opening adjustment mechanism for adjusting the opening of the flap 7. As the duct opening adjusting mechanism, a duct opening adjusting mechanism including a hydraulic drive mechanism 12 as shown in FIG. 2 can be used. Further, instead of the rotary flap 7, a sliding partition door 8 as shown in FIG.
May be used to configure a duct opening adjustment mechanism including the hydraulic drive mechanism 12.

In this air cushion ship, FIG.
As shown in FIG. 5, a duct 4 communicating with the atmosphere from the air cushion chamber 3 and a louver 5 capable of opening and closing the duct are provided, and a louver (not shown) for driving the louver 5 to adjust the opening degree of the duct 4. It has a louver-type duct opening adjustment mechanism including a drive mechanism.

Further, an internal pressure sensor for detecting the internal pressure of the air cushion chamber 3 and a wave height sensor for detecting the wave height of the waves outside the boat are provided, and a control system based on the detection signal from the internal pressure sensor is provided. A first control system that sends an opening control signal to the louver-type duct opening adjustment mechanism; and a second control system that sends a reference opening control signal to the hydraulic duct opening adjustment mechanism 12 based on a detection signal from the wave height sensor. It has a control system.

In the above configuration, during normal cruising when the sea surface is relatively calm, the standard value of the internal pressure of the air cushion chamber 3 corresponding to the reference draft is maintained by the second control system. The opening of the flap 7 is kept at a predetermined reference opening so that the standard value of the internal pressure is lowered according to the magnitude of the wave and the reference draft is deepened in stormy weather based on a detection signal from a wave height sensor. Therefore, the reference opening of the flap 7 is changed so as to be larger than the normal reference opening.

On the other hand, the first control system controls the internal pressure of the air cushion chamber 3 so as to maintain the standard value of the internal pressure determined by the second control system, that is, to reduce the fluctuation of the internal pressure. In such a case, the duct opening adjustment mechanism is controlled by adjusting the opening of the louver 5 based on the detection signal from the pressure sensor so as to return to the standard value.

In rough weather, when the opening of the flap 7 is changed and the reference draft becomes deeper, the air suction from the water jet intake port (not shown) of the hull 1 can be reduced, Air leakage can also be suppressed. When the opening of the flap 7 is changed to increase the opening of the duct 6 and the internal pressure of the air cushion chamber 3 is reduced from P ₁ to P ₂ as shown in FIG. 6, the characteristic curve changes from m to n. Because of the change, the air flow rate by the lift fan 2 increases from Q ₁ to Q ₃ , thereby making up for the increase in the air flow rate discharged to the atmosphere through the duct 6.

By the way, it is also possible to use the flap 7 as a duct opening / closing device for damping without providing the louver 5 for damping described in the present embodiment. In this case, the flap 7 is controlled by a control system as shown in FIG.

That is, the flap 7 corresponding to the standard draft
Is controlled by the second control system based on a detection signal from the wave height sensor. The first control system sets the reference opening as a neutral point so that the opening of the flap 7 is reduced. It is controlled based on the detection signal from the internal pressure sensor. Also in this case, substantially the same operation and effect as those of the above-described embodiment can be obtained.

Further, only the louver 5 is provided without providing the flap 7, and the control of the duct opening adjustment mechanism by the louver 5 is performed by the first control system and the second control system. Good.

[0023]

As described above in detail, according to the reference draft-adjustable air cushion ship of the present invention, the reference opening as the neutral point of the duct opening / closing device provided in the duct communicating from the air cushion chamber to the atmosphere. The following effects can be obtained by a simple means of increasing the air pressure in a wave so that the standard value of the internal pressure of the air cushion chamber can be reduced. (1) The standard draft of the ship's hull can be made deeper during stormy weather to reduce air leakage from around the air cushion room, and in the case of water jet propulsion, air intake from the intake can be reduced. (2) In order to compensate for the increase in the amount of pressurized air released into the atmosphere when the standard value of the internal pressure of the air cushion chamber drops during stormy weather, the supply flow rate of pressurized air should be reduced compared to when sailing in clear water. Can increase.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a reference draft-adjustable air cushion ship as one embodiment of the present invention.

FIG. 2 is an enlarged view showing a specific example of a main part of the air cushion ship.

FIG. 3 is an enlarged view showing another specific example of the main part shown in FIG. 2;

FIG. 4 is an enlarged view of another main part of the air cushion ship.

FIG. 5 is a block diagram showing an example of a control system in the air cushion ship.

FIG. 6 is a graph for explaining control characteristics of the air cushion ship.

FIG. 7 is a cross-sectional view of a conventional air cushion ship.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hull 1a Ship side wall 2 Lift fan 3 Air cushion room 4 Duct 5 Louver 6 Duct 7 Flap 8 Partition door 12 Hydraulic drive mechanism P Internal pressure

Claims (1)

[Claims] 1. An air cushion chamber, which is enclosed by left and right side walls and a bow seal and a stern seal and is opened downward, is provided at the bottom of the ship, and pressurized air is sent to the air cushion chamber to reduce draft of the hull. In an air cushion ship equipped with a lift fan for the, a duct communicating from the air cushion chamber to the atmosphere, an opening and closing device that can open and close the duct, and a duct opening adjustment mechanism that adjusts the opening of the duct opening and closing device And a pressure sensor for detecting the internal pressure of the air cushion chamber and a wave height sensor for detecting the wave height of the waves outside the boat, and can hold the standard value of the internal pressure corresponding to the reference draft at the time of sailing. With the reference opening of the duct opening and closing device as a neutral point, the duct is used to increase or decrease the opening of the duct based on a detection signal from the pressure sensor. A first control system for sending an opening control signal to the opening adjustment mechanism; and a reference for changing the neutral point to the duct opening adjustment mechanism to change the reference draft based on a detection signal from the wave height sensor. A reference draft-adjustable air cushion ship, comprising: a second control system that sends an opening control signal.