JPH101091A - Anti-rolling device for ship - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce restoring force of a hull after rolling by means of movement of a bob so as to reduce rolling of the hull by installing the bob freely moving according to inclination of the hull in the hull upper part and moving the bob along a supporting frame arranged in the direction crossing the hull. SOLUTION: In the center upper part of a hull 1 of a small size ship, a supporting frame 2 is arranged in the direction crossing the hull 1. A guide part 4 is arranged in the supporting frame 2, and along the guide part 4, a bob 3, from which a pendulum type bob 6 is suspended freely oscillationally, is supported freely movably. The guide part 4 is formed into a circular arc which is provided with an arc center arranged on the midship vertical line (a) and a single curvature and is recessed in the center, and the bob 3 is supported on the guide part 4 via a rolling wheel 5. If the hull 1 is held approximately horizontally in spite of rolling when a sea surface is calm, the bob 3 is positioned in the center part of the guide part 4. At the first inclination by which the hull 1 is rolled, the bob 3 moves in the inclination direction so as to shift the center of gravity of the hull 1 to the inclination side and works in the direction in which a restoring speed is reduced when the hull 1 is restored to the horizontal position. Therefore, rolling of the hull 1 is quickly reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a small boat or the like, and more particularly, to a boat swaying device which is effective for reducing the roll of a hull.

[0002]

2. Description of the Related Art Conventionally, various types of anti-rolling devices for ships have been proposed, but most of them are of a hull structure or of a configuration protruding outside the hull.

One of them is to provide anti-oscillation tanks on both sides of the center of the hull. The lower part of the anti-oscillation tank is communicated with the water and the upper part of the tank is communicated with the atmosphere. 2. Description of the Related Art There is an anti-oscillation device which restricts the inflow and outflow of seawater in a tank and causes an anti-oscillation effect when the height of seawater in left and right anti-oscillation tanks is different from the level of a flat water surface.

[0004] In addition, as described above, in the configuration in which the anti-roll tank is provided on both sides of the center of the hull, the boat is driven while seawater is still contained in the anti-roll tank during navigation, so that particularly high speed In a high-speed boat that sails at speed, a pair of attenuating tanks are provided on both sides at the bottom of the rear end of the hull, and when the lower part of the rear surface of the attenuating tank is exposed to the atmosphere during high-speed cruising, the seawater in the There has also been proposed a vibration damping device having a structure in which the water can be naturally drained out of a ship through a drain port provided at a lower portion to empty the vibration damping tank and travel. Documents showing such a conventional structure include, for example, JP-A-6-40380.

[0005]

As described above, in the case of a vibration-reducing device in which the movement of seawater into and out of the vibration-reducing tank is restricted to produce a vibration-reducing action, the vibration-reducing device is moved into the vibration-reducing tank in response to the vibration of the hull. The hull of the hull will be a relatively long sway when operating in the open sea where the sea surface condition is large swelling because the inflow and outflow of seawater is slow and slow. Therefore, it is possible to restrict the inflow and outflow of the seawater into and from the anti-oscillation tank, thereby causing the anti-oscillation effect.

[0006] However, when a small boat such as a fishing boat is operating in a moored state in a calm inland sea, the hull of the hull has a relatively short swaying period. The anti-shock effect of the anti-shock tank cannot be expected for a typical hull sway. However, when it receives waves generated as a large ship passes near it,
The hull sways very sharply, and until the sway is settled, the work may be hindered. Therefore, it is required to reduce the sudden swaying of the hull due to such waves as quickly as possible.

However, when a small vessel is equipped with the above-mentioned anti-shock tank, and the vessel is operating in a berthed state in a calm inland sea, the hull suddenly rises due to waves generated when a large vessel passes nearby. Considering the case of rolling, the wave of this kind has a short period and a large amplitude in the early stage, but it is a temporary wave that gradually decreases, so that With respect to the inclination (large sway), one of the sway tanks rises above the flat water surface while the seawater is still contained in the sway tank, and the weight acts in the sway direction. However, because the wave cycle is short, the hull immediately tilts to the opposite side, so both anti-shock tanks only repeat the upward and downward movement of the hull alternately with the hull while seawater hardly enters and exits Becomes
The sway of the hull will stop as the waves pass. In this case, it is not possible to quickly reduce a sudden sudden sway of the hull due to a wave caused by the passage of a large vessel.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a structure in which the hull upper part is freer than the inclination of the hull in order to quickly reduce the sudden sudden swaying of the hull while anchored. It is said that the weight to move to was installed.

As described above, by attaching the weight which can move freely from the inclination of the hull to the upper part of the hull, the weight moves in the inclination direction at the initial inclination when the hull suddenly swings, and the center of gravity of the hull is shifted to the inclination side of the hull. It moves in a direction that slows down the restoration speed when the hull attempts to restore horizontal by moving this weight, so that the subsequent movement of the weight against the sway of the hull exerts a force in a direction that is not synchronized with the wave cycle. To reduce the sway of the hull quickly.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a weight is attached to the upper part of a hull so as to move freely due to the inclination of the hull.

When the above-mentioned weight is mounted on the upper part of the hull, it is particularly effective to reduce the roll of the hull by providing a support base in a direction transverse to the hull and moving the weight along the support base. It is a target.

In addition, the support frame is formed with an arc-shaped guide portion having a center of a circular arc having a center of an arc on the vertical line of the center of the hull, and the weight is movably movable via a rolling wheel rolling on the guide portion. When supported, the weight can be stabilized in the vicinity of the center of the guide part in a normal sway of the hull such as when the sea surface condition is calm.

Further, when the pendulum-type weight is combined with the weight and the pendulum-type weight is suspended from the weight, the amount of movement due to the inertia of the weight is limited by the swing of the pendulum-type weight when the direction of inclination of the hull changes. Thus, the movement of the weight can be appropriately synchronized with the sway of the hull.

When a bearing is interposed in the base of the suspension of the pendulum-type weight and the pendulum-type weight is swung in the moving direction of the weight, the swing of the pendulum-type weight is smooth with respect to the swing of the hull. In addition, it is performed sensitively to increase the anti-rolling effect.

Further, the weight is constituted by a rotating body, the center of which is rotatably supported by a guide portion of a support base, and a sprocket provided on the weight is meshed with a guide chain provided in parallel with the guide portion to thereby provide a weight. Is rotated, the amount of movement due to the inertia of the weight is limited when the direction of inclination of the hull changes, and the movement of the weight can be properly synchronized with the sway of the hull.

The movement of the weight with respect to the initial inclination of the hull acts to reduce the restoring force of the hull by moving in the direction of inclination of the hull, but the restoring force of the hull itself is much larger than the moving weight of the weight. The effect of weakening the restoring force is only for the initial inclination of the hull, and its action time is very short, so that there is almost no effect on the restoring performance of the hull.

[0017]

Embodiments will be described with reference to the drawings.
In the figure, reference numeral 1 denotes a hull of a small boat,
Is a fishing boat type mainly operating in inland seas where the sea surface is calm. A support gantry 2 is provided at the center upper portion of the hull 1 in a direction crossing the hull 1, and a weight 3 that can move freely is attached to the support gantry 2.

A guide portion 4 is provided on the support base 2, and the weight 2 is movably supported along the guide portion 4.
As shown in FIG. 4, the guide portion 4 of the embodiment is formed in a middle concave arc shape with a single curvature centered on an arc center on the hull center vertical line a, and the rolling wheel 5 rolling on this guide portion 4 is formed. The weight 3 is movably supported through the shaft 3 and the weight 3 is located substantially at the center of the guide portion 4 in a normal swing where the sea surface state is gentle and the hull 1 is almost horizontal. I am trying to be stable.

A pendulum-type weight 6 is suspended from the weight 3 so as to be swingable. A bearing 8 is interposed at the base of the hanging member 7 of the pendulum type weight 6, and the bearing 8 is pivotally supported by a concave portion provided at the center of the lower surface of the weight to direct the pendulum type weight 6 in the moving direction of the weight 3. And swing freely.

In the above configuration, as shown in FIG. 4, when the hull 1 is initially tilted, the weight 3 moves in the tilting direction to move the center of gravity of the hull 1 to the hull tilt side, and the hull 1 is restored to a horizontal position. In the above embodiment, when the inclination direction of the hull 1 changes, the amount of movement of the weight 3 due to inertia is limited by the swing of the pendulum type weight 6, and thereafter, When the hull 1 tilts in the opposite direction to restore horizontal, the moved weight 3 acts as a force in a direction not synchronized with the wave cycle, so that the sway of the hull 1 is quickly reduced. is there.

In the embodiment shown in FIGS. 5 and 6, the weight 3 has a rotating body structure, and a rolling wheel 5 is mounted on the center axis of the weight 3 and is rotatably supported on the guide portion 4 of the supporting member 2. ,
Instead of the pendulum type weight 6, a sprocket 9 is provided on the weight 3, and this sprocket 9 is meshed with a guide chain 10 provided in parallel with the guide part 4, and the weight 3 is supported by the guide part 4 and rotates. At the same time as the sprocket 9 moves away from the center of rotation and meshes with the guide chain 10 and rotates, the weight 3
The movement of the weight 3 is appropriately synchronized with the sway of the hull 1 by limiting the amount of movement due to the inertia of the vehicle.

Incidentally, the positional relationship of the support base 2 with respect to the hull 1, the curvature of the guide 4 (radius from the center of the circular arc on the hull center vertical line a), the length of the guide 4 and the weight of the weight 3 Regarding the weight of the pendulum-type weight 6, the length of the hanging member 7 of the pendulum-type weight 6, the radius of the sprocket 9, and the like,
It is set experimentally depending on the type and purpose of use of the hull 1 and the hull weight. For example, the width of the center of the hull is 2m,
When applied to a general-purpose fishing boat type hull 1 having a hull length of 10 m and a hull weight of about 4 tons, the weight of the weight 3 is about 2
The weight of the pendulum type weight 6 is about 16 kg.

Experimental Example FIGS. 7A, 7B, and 7C are graphs showing the results of a vibration reduction experiment using a model hull using an experimental water tank.

In this shaking experiment, a model hull was floated in an experimental water tank, and when a wave was generated with the same strength, the rolling (rolling) of the model hull was measured from the start to the end of the shaking. As for the time, one graduation on the horizontal axis indicates 0.5 seconds.

Graph (a) shows a case where both the weight and the pendulum type weight are fixed to the support base and the weight does not function to reduce rocking. The hull sways almost in sync with the wave cycle, and it takes a considerable amount of time for the hull to subside.

Graph (b): A case where the pendulum-type weight is fixed to the weight, and both weights are integrally movable with respect to the support base. In the first sway of the hull, both weights move together in the sway direction, reducing the restoring force of the hull, slowing the restoration speed, and applying force in a direction that is not synchronized with the wave cycle, reducing the sway of the hull ing.

Graph (c): The case where both the weight and the pendulum weight are free to move. At the first sway of the hull, both weights move together to reduce the restoring force of the hull and slow down the restoration speed, but after this, the pendulum weight swings sensitively in response to the sway of the hull, The inertial motion due to the inertia of the hull is eliminated, and the movement (movement) of the weight is adapted to the sway of the hull, and the synchronization with the wave cycle is broken. Therefore, the sway of the hull is observed in the early stage of the wave generation, but thereafter, the sway of the hull is rapidly reduced.

[0028]

The present invention is embodied in the form described above and has the following effects.

The present invention is applied to a small boat, and a weight that can freely move in the direction of the hull is attached to the upper part of the hull, and generated when a large boat passes by while the boat is anchored and operating. When the hull sways due to waves, etc., the weight moves and the restoring force of the hull after weakening is weakened, the restoration speed is slowed, the synchronization with the wave cycle is lost, and the hull of the hull is reduced equivalently, This makes it possible to reduce the swiftness rationally and quickly so that there is no hindrance to offshore work.

Further, a support base is provided in a direction crossing the hull,
If you move the weight along this support base,
The roll of the hull can be effectively reduced. In addition, if a circular arc-shaped guide part with a single curvature is formed on the support base and a weight is supported via a rolling wheel on this guide part, it is possible to prevent the hull from swaying normally when the sea surface condition is calm. In this way, the weight can be stably eliminated in the vicinity of the center of the guide portion to eliminate unnecessary movement.

Further, by adopting a configuration in which the pendulum weight is suspended from the weight, the amount of movement due to the inertia of the weight is limited when the direction of swing of the hull changes, and the movement of the weight is appropriately synchronized with the sway of the hull. be able to. In addition, by interposing a bearing at the base of the hanging member of the pendulum weight and swinging the pendulum weight in the moving direction of the weight, the swing of the pendulum weight is performed smoothly and sensitively, and reduced. Increase the shaking action.

Further, the weight is constituted by a rotating body, the center of which is rotatably supported by the guide portion of the support member, and the sprocket provided on the weight is engaged with the guide chain provided on the support member. In addition, the amount of movement due to the inertia of the weight is limited when the direction of swing of the hull changes, and the movement of the weight can be properly synchronized with the sway of the hull.

Further, since the apparatus of the present invention is mounted on the upper part of the hull and does not require a special power source and does not require improvement of the hull, it can be easily applied to both existing ships and newly built ships.

[Brief description of the drawings]

FIG. 1 is a front view of a ship equipped with the device of the present invention.

FIG. 2 is a side view of a ship equipped with the apparatus of the present invention.

FIG. 3 is a perspective view in which a part of a weight which is a main part of the present invention is omitted.

FIG. 4 is a front view of a ship for explaining the operation of the apparatus of the present invention.

FIG. 5 is a front view of an apparatus showing another embodiment of the present invention.

FIG. 6 is a side view of an apparatus showing another embodiment of the present invention.

FIGS. 7 (a), (b), and (c) are graphs showing the results of a vibration reduction experiment using an experimental water tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hull 2 Support stand 3 Weight 4 Guide part 5 Roller wheel 6 Pendulum type weight 7 Hanging tool 8 Bearing 9 Sprocket 10 Guide chain

Claims (6)

[Claims] 1. An anti-rolling device for a ship, comprising a weight attached to an upper portion of the hull so as to move freely from the inclination of the hull. 2. The ship rocking apparatus according to claim 1, wherein a support base is provided on the hull in a direction crossing the hull, and the weight is moved along the support base. 3. The support frame is formed with an arcuate guide portion having a single curvature and a middle depression, and the weight is movably supported via a rolling wheel rolling on the guide portion. Ship rocker. 4. The apparatus according to claim 1, wherein a pendulum-type weight is slidably suspended from the weight. 5. A ship rocking apparatus according to claim 4, wherein a bearing is interposed in the base of the hanging member of the pendulum type weight to swing the pendulum type weight in the moving direction of the weight. 6. A weight is constituted by a rotating body, a center portion of which is rotatably supported by a guide portion of a support base, and a sprocket provided on the weight is meshed with a guide chain provided in parallel with the guide portion. 4. The ship swaying device according to claim 1, 2, or 3.