JPH1111385A - Method and apparatus for preventing pitching of hull - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent vertical swing of a hull with a simple device even when the ship is stopped. A method for preventing pitching of a hull, wherein a strut supporting the hydrofoil causes a pendulum motion on the hydrofoil to generate a moment in a direction opposite to the pitching of the hull. The apparatus also includes a hydrofoil 3 disposed underwater, a strut 2 for supporting the hydrofoil 3 from the hull 1, a driving mechanism 5 for driving the strut 2 in a pendulum, and a control unit 6 for controlling the driving mechanism 5. This is a device for preventing the hull from pitching.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for preventing a hull from pitching.

[0002]

2. Description of the Related Art Hull of a hull is caused by pitching,
There are rolling (rolling), lateral movement (yawing), and the like. Preventive measures are roughly classified into the following methods. (1) A method of balancing by changing the center of gravity of the ship by moving seawater and weights in the rocking tank. (2) A method of reducing sway using a propulsion device (propeller, water jet, etc.). (3) A method of using a lift acting on a fin to reduce the motion of a ship. (4) A method of adding a fluid nozzle to the fin to reduce the motion of the ship.

Japanese Patent Application Laid-Open No. Hei 7-228292 discloses a method of reducing the sway of a ship by using the lift acting on the fins of the above (1) to (4).

The technique disclosed in the above publication includes a strut which descends from the storage room near the end of the hull to the bottom of the hull by a lifting drive mechanism, and fins for preventing pitching mounted on the strut. The fin is moved up and down together with the strut by controlling a lifting drive mechanism via a control system based on a signal from a pitch sensor,
A lift is generated in the fin by the water flow flowing into the fin at an angle of attack corresponding to the direction of the combined vector of the moving speed of the fin in the vertical direction and the flow velocity, and the vertical motion of the hull is canceled by the moment due to the lift. It is.

[0005]

However, in the prior art disclosed in the above-mentioned Japanese Patent Application Laid-Open No. Hei 7-228292, lift due to the water flow on the fin wing surface can be expected for pitching during sailing. In the vertical pitching, no lift is generated by the water flow on the fin wing surface, so that only a damper effect due to vertical movement can be expected. Therefore, the effect of preventing pitching at the time of stopping the ship cannot be expected.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problem of preventing vertical swing when the boat is stopped.

[0007]

A first means for solving the above-mentioned problem is characterized in that a strut for supporting the hydrofoil performs a pendulum motion on the hydrofoil to generate a moment opposite to the pitching of the hull. This is a method for preventing the hull from pitching.

[0008] A second means for solving the above-mentioned problems includes a hydrofoil arranged in water, a strut for supporting the hydrofoil from the hull, a drive mechanism for driving the strut to pendulum, and controlling the drive mechanism. And a control unit for controlling the vertical motion of the hull.

According to the present invention, when pitching occurs in the hull during sailing or when the boat is stopped, the hydrofoil at the tip of the strut is pendulum-moved through the control unit and the pendulum drive unit by detecting a sensor, and acts on the hydrofoil. The lift is controlled to generate a force in a direction opposite to the wave forcing moment, thereby canceling the wave forcing moment and preventing the hull from pitching.

Further, even when the boat is stopped, the hydrofoil is driven by the pendulum, so that the acceleration of the hydrofoil generates a lift due to the water flow on the hydrofoil surface, thereby improving the pitching prevention force.

That is, when the pitching moment of the bow lowering acts as an external wave force, the movement of the strut is controlled so that the force acting on the hydrofoil is directed upward. When working as a strut, the strut movement is controlled so that the force acting on the hydrofoil is downward.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of an apparatus for preventing pitching of a hull according to the present invention, wherein 1 is a hull, 1a is a bow of the hull 1,
1b is a ship bottom.

Reference numeral 2 denotes a strut extending from the bottom 1b of the hull 1. At the tip of the strut 2, hydrofoils 3, 3 are fixed via an attachment portion 4.

FIG. 2 is a side sectional view of a hull pitching prevention apparatus according to the present invention. The strut 2 having the hydrofoil 3 attached to the tip is provided so as to extend from the inside of the hull 1 and is attached to a drive mechanism 5 inside the hull 1.

The drive mechanism 5 is, for example, a drive wheel 5
The end of the strut 2 is connected to a link 5b connected to a, and the strut 2 and the hydrofoil 3 perform a pendulum motion by rotating the drive wheel 5a.

Reference numeral 6 denotes a control unit for controlling the driving mechanism 5, which receives the information on the motion of the hull 1 from a tilt sensor and an acceleration sensor (not shown) by a signal and controls the driving mechanism 5 in a phase opposite to that of the waves.

FIG. 3 is a graph showing the force acting on the hydrofoil according to the present invention. The forcible pendulum motion of the hydrofoil 3 according to the present invention allows the hydrofoil 3 to combine the lift and the fluid force during acceleration / deceleration. The generated fluid force 7 is generated.

The fluid force 7 varies depending on the speed of the hydrofoil 3 and the angle at which the hydrofoil 3 is attached to the strut. Therefore,
The pendulum motion is controlled such that the wave moment acting on the hull and the fluid force 7 cancel.

FIGS. 4A and 4B are side views showing the relationship between the hydrofoil and the pitching of the hull 1 according to the present invention.

In FIG. 4A, when the right end of the hull 1 rotates in the sinking direction R ₁ , the pendulum motion of the hydrofoil 3 is:
Moves in the direction in which a force F ₁ against it.

In FIG. 4B, when the left end of the hull 1 rotates in the sinking direction R ₂ , the pendulum motion of the hydrofoil 3 is
Moves in the direction in which a force F ₂ against it.

FIG. 5 is a perspective view of a second embodiment in which the present invention is applied to a catamaran. In FIG. 5, the twin hulls 1c and 1d are provided with extending struts 2a and 2b, respectively, and both ends of the hydrofoil 3 are supported at the lower ends thereof via a mounting portion 4 to perform a pendulum motion. It has become.

With this structure, both ends of the hydrofoil 3 are supported, so that the blade area can be increased.

The structure in which the struts 2a and 2b support both ends of the hydrofoil 3 can be applied to a single hull and a wide hull.

FIGS. 6 (a), 6 (b) and 6 (c) are front views showing an embodiment of a hydrofoil mounting structure according to the present invention to the catamaran.

FIG. 6A shows the strut 2 of the hydrofoil 3.
a and 2b are structures provided vertically when viewed from the front.

FIG. 6B shows the strut 2 of the hydrofoil 3.
When viewed from the front, a and 2b are provided in a C-shape so as to extend downward and open. With this structure, the wing area can be increased by an amount corresponding to the outward projection.

FIG. 6C shows the strut 2 of the hydrofoil 3.
When viewed from the front, a and 2b are provided in an inverted U-shape and are provided at an angle that opens upward. With this structure, the hydrofoil can be firmly supported.

FIGS. 7 (a), 7 (b) and 7 (c) are plan views of struts 2a and 2b supporting both ends of the hydrofoil 3 cut along the water surface, and show an embodiment of the arrangement in the longitudinal direction of the hull.

FIG. 7A shows a state in which the struts 2a and 2b are arranged parallel to the hull center line.

FIG. 7B shows a structure in which the struts 2a and 2b are arranged so as to close forward with respect to the hull center line. With this structure, when an auxiliary wing (not shown) is attached to the trailing edge of the hydrofoil 3, the area of the auxiliary wing can be increased.

FIG. 7C shows a structure in which the struts 2a and 2b are arranged so as to open forward with respect to the center line of the hull. With this structure, the resistance acting on the strut 2 can be reduced.

[0034]

As described above, the present invention enables control of pitching prevention not only at the time of sailing but also at the time of stopping the ship.

Further, since the control is a simple pendulum motion drive control, there is an advantage that a simple device is sufficient.

[Brief description of the drawings]

FIG. 1 is a perspective view of a hull pitching prevention apparatus according to the present invention.

FIG. 2 is a side sectional view schematically showing a hull pitching prevention apparatus according to the present invention from a side.

FIG. 3 is a graph showing a force acting on a hydrofoil in the present invention.

4A and 4B are side views illustrating the relationship between the hydrofoil and the pitch of the hull according to the present invention, wherein FIG. 4A is a state in which a bow sinks, and FIG. This shows a state where the part is raised.

FIG. 5 is a perspective view of a second embodiment in which the present invention is applied to a catamaran.

FIG. 6 (a) is a front view showing an embodiment of a structure when the hydrofoil according to the present invention is attached to the catamaran.
(B) It is a front view which shows embodiment of the structure at the time of attaching the hydrofoil which concerns on this invention to the said catamaran. (C) It is a front view which shows embodiment of the structure at the time of attaching the hydrofoil which concerns on this invention to the said catamaran.

FIG. 7A is a plan view in which struts supporting both ends of a hydrofoil according to the present invention are cut along a water surface line. (B) It is the top view which cut the strut which supports both ends of the hydrofoil concerning this invention by the water surface line. (C) It is the top view which cut the strut which supports both ends of the hydrofoil concerning this invention by the water surface line.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hull 1a Bow 1b Ship bottom 2 Strut 2a Strut 2b Strut 3 Hydrofoil 4 Mounting part 5 Drive mechanism 6 Control part 7 Fluid force

Claims (2)

[Claims] 1. A method for preventing pitching of a hull, wherein a strut for supporting the hydrofoil performs a pendulum motion on the hydrofoil to generate a moment in a direction opposite to the pitching of the hull. 2. A vertical hull comprising a hydrofoil disposed in water, a strut for supporting the hydrofoil from a hull, a drive mechanism for driving the strut to pendulum, and a control unit for controlling the drive mechanism. Anti-sway device.