JP2010228503A - Swing reducer of floating body type marine structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a swing reducer of a floating body type marine structure capable of preventing the deterioration in sailing performance and fuel consumption, by putting a member in a withdrawal state of being pulled up from a water surface, in self-sailing and towing of a floating body, by providing the optimal swing reducing effect in response to a state such as draft and oceanographic conditions, by changing a state of the member arranged on the water surface and in the water for providing the swing reducing effect. <P>SOLUTION: This swing reducer has a duct-shaped opening type swing reducing tank 21 extended in the vertical direction, for respectively forming a lower end side opening 24 functioning as a water inlet-outlet port on the lower end side and an upper end side opening 25 functioning as an air inlet-outlet port on the upper end side, and controls a position in the vertical direction in response to the state by movably supporting the opening type swing reducing tank 21 in the vertical direction. The opening type swing reducing tank 21 can move in an operation state of positioning the lower end side opening 24 in the water and the withdrawal state of withdrawing the lower end side opening 24 from the water surface. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an anti-vibration device for reducing the shaking of a floating offshore structure (hereinafter referred to as a floating body) that is used for mining oil and mineral resources on the ocean. It relates to a rocking device.

  In floating bodies that mine oil or mineral resources offshore, it is desirable to reduce the fluctuations caused by waves in order to improve the operating rate. An anti-vibration device is used.

  As an anti-vibration device, an open type anti-vibration tank has been proposed in which an air inlet / outlet is provided at the upper end of a duct-like water channel extending in the vertical direction and a water inlet / outlet is provided at the lower end. By installing an open type anti-vibration tank on the floating body, when the floating body shakes, water enters and exits from the water inlet / outlet, creating a phase difference between the shaking and the fluctuation of the water level in the shaking tank, and reducing the fluctuation. It acts as a rocking moment (see, for example, Patent Document 1).

  Further, as a vibration reducing device, a vertical plate is supported along a substantially vertical direction via a plurality of stays on one side surface of the floating body, and a penetrating portion that allows water to flow between the floating body and the vertical plate is provided. It has been proposed that the upper end of the vertical plate be located at substantially the same height as the bottom surface of the floating body. A wave hits the side of the floating body and the vertical plate, and part of the water passes through the penetration. Accordingly, the vertical plate becomes resistance to rolling of the floating body, and further increases resistance when the fluid passes through the penetrating portion, so that fluctuation of the floating body can be reduced (see, for example, Patent Document 2).

  Furthermore, as a vibration reduction device, a pair of swing mechanisms composed of a folding crane or the like is attached to the hull, and when the ship stops, the float is gripped by the grip portion at the tip of the swing mechanism and is swung out in the width direction of the hull. It has been proposed to land. Thereby, a ship becomes a 3 body type at the time of a ship stop, and even if a wave acts, a shake of a ship can be reduced (for example, refer to patent documents 3).

  Furthermore, as a vibration reduction device, a well opening area changing member that adjusts the opening of a well as a water inlet / outlet at the center of the lower hull in a floating body provided with a platform at the upper end of a column erected on the lower hull in the water is provided. Proposed to provide. Thereby, since the aperture ratio of a well can be adjusted according to the state of a wave, the fluctuation of a floating body can be reduced exactly (for example, refer patent document 4).

Japanese Patent Laid-Open No. 03-90497 JP 2002-37184 A JP-A-11-227686 Japanese Utility Model Publication No. 06-13997

  However, in the prior art, in order to obtain a vibration reduction effect, a member disposed on the surface of the water or in the water, that is, an open type vibration reduction tank in Patent Document 1, a vertical plate in Patent Document 2, a float in a state of being swung out in Patent Document 3. Since the lower hull in Patent Document 4 is fixedly provided to the floating body, there is a problem that the effect of reducing the vibration may be lowered depending on the conditions such as draft and sea conditions. .

  The present invention has been made in view of such a situation, and by changing the state of the water surface and the members disposed in the water in order to obtain a vibration reduction effect, the present invention is optimal according to the situation such as drafts and sea conditions. A floating offshore structure that can obtain a vibration reduction effect and can prevent deterioration of navigation performance and fuel consumption by pulling the same member up from the water surface during self-propulsion or towing of the floating body An object of the present invention is to provide a vibration reduction device.

  In order to solve the above-mentioned problem, a floating offshore structure rocking device according to the present invention corresponding to claim 1 is mounted on a floating offshore structure, and is a floating body that reduces fluctuation of the floating offshore structure. A marine structure vibration reduction device having a lower end opening functioning as a water inlet / outlet at the lower end side and an upper end opening functioning as an air inlet / outlet at the upper end side, and extending vertically The open-type anti-vibration tank is supported so as to be movable in the vertical direction, and the vertical position of the open-type anti-vibration tank is determined by the drive means depending on the situation. Is controllable. The open-type anti-vibration tank is disposed on both sides of the open-type anti-vibration tank, for example, and is formed with a pair of guide rods extending in the vertical direction and an opening through which the guide rod penetrates. Each of the fixed guide pieces can be supported so as to be movable in the vertical direction. Moreover, as a drive means, it can comprise with the crane which hangs an open type anti-vibration tank and raises / lowers.

  Furthermore, the rocking device for a floating offshore structure according to the present invention is characterized by comprising opening area adjusting means for adjusting the area of the opening on the lower end side of the open type shaking tank. As an opening area adjustment means, it can be comprised, for example with the door slidably provided in the lower end side opening.

  Furthermore, the rocking device for a floating offshore structure according to the present invention is characterized in that a resistance means for imparting a frictional resistance to water is provided in the open type shaking tank. As the resistance means, for example, a baffle plate standing in an open type anti-vibration tank can be configured, and by arranging a plurality of baffle plates alternately, the channel length of the open type anti-vibration tank is desired. Can be extended to length.

  Furthermore, in the rocking device of the floating offshore structure of the present invention, the open-type rocking tank is in an operating state in which the lower end side opening is located in water by the driving means, and a retracted state in which the lower end side opening is lifted from the water surface. And is movable.

  Furthermore, in the rocking device for a floating offshore structure according to the present invention, the open type anti-shock tank is capable of adjusting the water depth at which the lower end side opening is located in an operating state in which the lower end side opening is located in water. Features.

  According to a sixth aspect of the present invention, there is provided a floating offshore structure rocking device according to the present invention, which is mounted on the floating offshore structure and reduces the shaking of the floating offshore structure. The lower end side opening that functions as a water inlet / outlet is formed on the lower end side, and the upper end side opening that functions as an air inlet / outlet is formed on the upper end side, and an open type anti-vibration tank that extends in the vertical direction and is opened. An internal water control means for controlling the movement of the internal water in the mold reduction tank, and the natural period in the open-type vibration reduction tank can be controlled according to the size of the internal water control means. And The internal water control means can be constituted by a float member arranged in an open type anti-vibration tank.

  Furthermore, in the rocking device for floating offshore structure of the present invention, the vertical movement of the internal water control means in the open type shaking tank is controlled.

  Furthermore, the floating offshore structure rocking device of the present invention comprises a driving means for driving the open-type rocking tank, the operating state in which the lower end opening is located in water, and the lower end opening is lifted from the water surface. The open type anti-vibration tank can be moved by the driving means in the removed state.

  Furthermore, in the rocking device for a floating offshore structure according to the present invention, the position of the open-type rocking tank is controlled by driving means according to draft or sea conditions.

  Further, the floating offshore structure rocking device of the present invention corresponding to claim 10 is mounted on the floating offshore structure, and the floating offshore structure rocking device that reduces the fluctuation of the floating offshore structure. A float plate that absorbs the energy of the waves by facing the water surface, and a drive means for driving the float plate, and the float plate is arranged in a vertical direction or a rotation direction with one end as an axis. It is supported so as to be movable, and the position relative to the water surface can be controlled by the driving means according to the situation.

  Furthermore, in the rocking device for a floating offshore structure of the present invention, the float plate can be moved by the driving means between an operating state facing the water surface and a retracted state pulled up from the water surface.

  The rocking device for a floating offshore structure according to the present invention extends in the vertical direction, with a lower end opening functioning as a water inlet / outlet at the lower end side and an upper end opening functioning as an air inlet / outlet at the upper end side. The open-type anti-vibration tank is supported so that it can move in the vertical direction, and the vertical position can be controlled by the driving means according to the conditions such as drafts and sea conditions. The natural period can be adjusted by changing the amount of internal water in the open type anti-vibration tank by moving the member placed in the open-type anti-vibration tank in the vertical direction according to the situation by the driving means, and the optimal reduction There is an effect that a rocking effect can be obtained. In addition, in a situation where no vibration reduction is required, the open type vibration reduction tank can be withdrawn by the driving means, and the natural period can be adjusted and withdrawn by the same driving means.

  Furthermore, in the rocking device for a floating offshore structure of the present invention, the area of the lower end side opening can be adjusted by the opening area adjusting means. Therefore, by adjusting the opening area depending on the situation, The effect of adjusting the effective inflow coefficient according to the speed of water entering and exiting the vehicle to optimize the anti-sway braking effect is achieved. Moreover, when the vibration reduction is unnecessary, the opening area can be reduced to zero to prevent the invasion of marine organisms and foreign substances from the lower end opening into the open vibration reduction tank.

  Furthermore, in the rocking device for a floating offshore structure of the present invention, by providing resistance means for imparting frictional resistance to water in the open type anti-vibration tank, the speed of water entering and exiting the open type anti-vibration tank By adjusting the frictional resistance according to the above, there is an effect that the damping braking effect can be increased without increasing the volume of the open type damping tank. Further, depending on the number and arrangement of the resistance means, there is an effect of adjusting the natural period of the internal water of the open type anti-vibration tank by lengthening the flow path of the internal water of the open type anti-vibration tank.

  Furthermore, in the rocking device for a floating offshore structure according to the present invention, the open-type anti-vibration tank is driven by the driving means into an operating state where the lower end opening is located in water and a retracted state where the lower end opening is pulled up from the water surface. The position of the open-type anti-vibration tank can be lifted from the water surface and removed by switching the position of the open-type anti-vibration tank to the retracted state with the driving means during navigation by self-propulsion or towing. It is possible to prevent the deterioration of the navigation performance and the fuel consumption caused by the open type anti-vibration tank. In addition, by removing the open-type anti-vibration tank from the water surface and removing it in a situation where it is not needed, marine organisms can be prevented from adhering to the open-type anti-vibration tank, and deterioration of the material due to seawater can be reduced. And maintenance such as removal of marine organisms.

  Furthermore, in the rocking device for a floating offshore structure of the present invention, in the operating state, the depth at which the opening on the lower end side of the open type anti-vibration tank is located can be adjusted according to the situation by the driving means. By adjusting the vertical position of the anti-vibration tank, it becomes possible to set the amount of water inside the open-type anti-vibration tank to the optimal amount of water depending on the draft and the floating body tilt. There is an effect that the natural period of water can be adjusted to obtain a sufficient vibration reduction effect. Moreover, contact with the seabed and rocks can be avoided by adjusting the water depth position of the open type anti-vibration tank according to the seabed and the water depth of the rocks.

  Further, in the rocking device for a floating offshore structure of the present invention, the state of the internal water is controlled by the size of the internal water control means provided in the open type anti-vibration tank. The natural cycle can be controlled by changing the amount of water in the internal water, and the internal water passage of the open type anti-vibration tank can be adjusted, so the movement of the internal water can be adjusted and the anti-vibration braking effect can be controlled. Play. In addition, by enlarging the internal water control means and closing the passage in the open type anti-vibration tank, it is possible to expect an anti-vibration effect by the taken-in air.

  Furthermore, in the rocking device for floating offshore structure of the present invention, by controlling the vertical movement of the internal water control means in the open-type rocking tank, it is optimal according to the conditions such as drafts and sea conditions. The effect that it is possible to obtain an effective vibration reduction effect is achieved.

  Furthermore, in the rocking device for a floating offshore structure according to the present invention, the open-type anti-vibration tank is operated by the driving means between the operating state where the lower end opening is located in water and the retracted state where the lower end opening is pulled up from the water surface. By making the structure movable, the open-type anti-vibration tank can be lifted from the water surface and removed by switching the position of the open-type anti-vibration tank to the retracted state with the driving means during self-navigation or towing. It is possible to prevent the deterioration of the navigation performance and the fuel consumption caused by the open type anti-vibration tank. In addition, by removing the open-type anti-vibration tank from the water surface and removing it in a situation where it is not needed, marine organisms can be prevented from adhering to the open-type anti-vibration tank, and deterioration of the material due to seawater can be reduced. And maintenance such as removal of marine organisms. In addition, it is possible to move the open-type anti-vibration tank in the vertical direction by the driving means, and the movement of the internal water of the open-type anti-vibration tank can be adjusted in cooperation with the internal water control means. Can be expanded.

  Furthermore, in the rocking device for a floating offshore structure according to the present invention, the position of the open type anti-vibration tank is controlled by the driving means in accordance with the draft or sea conditions, so that the open type anti-vibration tank is changed when the draft changes. The position of the open-type anti-vibration tank can be prevented from being adjusted and the natural period of the internal water of the open-type anti-vibration tank can be adjusted differently, and the position of the open-type anti-vibration tank can be controlled according to stormy weather and the magnitude of the waves. As a result, the optimum natural period and braking force can be set.

  Further, in the vibration reduction device of the present invention, the float plate that absorbs the energy of the waves by facing the water surface is supported so as to be movable in the vertical direction or the rotation direction with one end as an axis, and the driving means according to the situation By configuring so that the position of the float plate relative to the water surface can be controlled, there is an effect that the natural period can be adjusted by changing the contact state of the float plate with respect to the water surface. In addition, when the vibration is not required, the float plate can be withdrawn by the driving means, and the natural period can be adjusted and withdrawn by the same driving means.

  Furthermore, in the vibration reduction device of the present invention, the float plate can be moved to the retracted state pulled up from the water surface by the driving means, so that the position of the float plate is withdrawn by the driving means during navigation by self-propulsion or towing. By switching to, the float plate can be lifted from the water surface and withdrawn, and the navigation performance and fuel consumption caused by the float plate can be prevented. Also, by lifting the float plate from the surface and removing it in a situation that does not require shaking, it is possible to prevent the attachment of marine organisms to the float plate, reduce the deterioration of the material due to seawater, paint, remove marine organisms, etc. Maintenance can be easily performed.

It is a general view which shows the example of equipment to the floating body of 1st Embodiment of the vibration reduction apparatus which concerns on this invention. It is a figure which shows the structure when 1st Embodiment of the vibration reduction apparatus which concerns on this invention is an operation state, (a) is the top view seen from the upper direction, (b) is a floating body It is the front view seen from the side direction, (c) is the side view seen from the front-back direction of the floating body. It is a figure which shows the structure at the time of 1st Embodiment of the vibration reduction apparatus which concerns on this invention being a withdrawal state, (a) is a top view seen from the upper direction, (b) is a floating body It is the front view seen from the side direction, (c) is the side view seen from the front-back direction of the floating body. It is a figure which shows the structure of the lower end side opening shown in FIG. 2, (a) is the front view seen from the side direction of the floating body, (b) is XY sectional drawing shown to (a). It is the front view which looked at 2nd Embodiment of the vibration reduction apparatus which concerns on this invention from the side direction of the floating body, (a) is a figure which shows the structure of an operation state, (b) is a withdrawal state. It is a figure which shows a structure. It is a longitudinal cross-sectional view which shows the structure of 3rd Embodiment of the vibration reduction apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows the structure of 4th Embodiment of the vibration reduction apparatus which concerns on this invention. It is the side view which looked at the structure of 5th Embodiment of the vibration reduction apparatus which concerns on this invention from the front-back direction of the floating body, (a) is a figure which shows the structure of an operation state, (b) is withdrawal. It is a figure which shows the structure of a state.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
Referring to FIG. 1, a floating body 1 for mining oil or mineral resources on the ocean can be self-navigated or towed in the navigation direction indicated by the arrow A, and the roll of the floating body 1, that is, the longitudinal direction of the floating body In order to reduce the rotational fluctuation of the shaft, the vibration reduction device 2 according to the first embodiment is installed at the symmetrical position of both sides of the floating body 1. Note that, depending on the structure of the floating body 1, the arrangement of the vibration reduction device 2 may not be symmetrical with respect to both sides, and is not limited to both sides. The vibration reduction device 2 is provided so as to be movable in the vertical direction indicated by the arrow B, and can be adjusted in the vertical direction, and can be withdrawn from the water when the floating body 1 is navigated by self navigation or towing. It is configured.

  As shown in FIG. 2, the vibration reduction device 2 is a duct-shaped open-type vibration reduction tank 21 extending in the vertical direction, and a pair of guide bars 22 extending in the vertical direction are provided on both sides of the open-type vibration reduction tank 21. Guide pieces 23 each having an opening through which the guide rod 22 is formed are fixed on both side surfaces of the open type anti-vibration tank 21.

  The guide bar 22 is fixed substantially parallel to the heel side of the floating body 1. Therefore, the open type anti-vibration tank 21 has the guide bar 22 penetrating through the guide pieces 23 fixed on both side surfaces. Therefore, it is guided by the guide rod 22 and is attached so as to be movable in the vertical direction on the heel side of the floating body 1.

  The lower end side of the open type anti-vibration tank 21 is bent in an L shape in a direction away from the floating body 1, and the lower end side opening 24 is formed in a direction substantially perpendicular to the heel side of the floating body 1. In FIG. 2, the lower end side opening 24 is submerged in water so that the lower end side opening 24 functions as a water inlet / outlet, and the upper end side opening 25 formed on the upper end side of the open type anti-vibration tank 21 functions as an air inlet / outlet. The operating status is shown. In such an operating state, when the floating body 1 is shaken, water enters and exits from the lower end side opening 24 that functions as a water inlet / outlet, and a phase difference is generated between the shake and the fluctuation of the water level of the open type anti-vibration tank 21. By acting as a swinging moment, the swinging of the floating body 1 can be reduced.

  The open type anti-vibration tank 21 can be moved in the vertical direction, so that the depth of the lower end side opening 24 can be adjusted. That is, the length of the water channel formed in the open type anti-vibration tank 21 changes according to the water depth of the lower end side opening 24, and the water channel length becomes longer as the depth of the lower end side opening 24 becomes deeper. It is possible to increase the natural period of the vibration reducing tank 21. Therefore, the vibration reduction effect can be improved by adjusting the depth of the lower end side opening 24 by moving the open type vibration reduction tank 21 in the vertical direction according to the draft of the floating body 1, sea conditions, and the like. .

  In addition, as for the vertical movement of the open type anti-vibration tank 21, for example, a pair of wire attachment portions 26 are formed in the open type anti-vibration tank 21, and a wire 27 spanned between the pair of wire attachment portions 26 is provided in the floating body 1. It can be performed by hanging up and down with the crane 3 which is the driving means. In the present embodiment, the means for moving the open type anti-vibration tank 21 in the vertical direction is not limited to the crane 3, and the open type anti-vibration tank 21 is provided with a motor so that the open type anti-vibration tank 21 itself can move. Arbitrary means such as moving can be used. By configuring the drive means with a motor, it is possible to adjust the amount of internal water in the open type anti-vibration tank 21, perform anti-vibration braking by the electromagnetic force of the motor, and regenerate power.

  A control means for controlling the position of the open type anti-vibration tank 21 according to the draft or sea condition may be provided so that the position of the open type anti-vibration tank 21 is changed according to the draft or sea condition. . The control means stores in advance the position of the open-type anti-vibration tank 21 corresponding to the draft or sea condition as tank position information, or inputs the value of the draft or sea condition, for example, the draft by the equipped program. The input of the sensor to perform and the input of the wave height are received, and the open type anti-vibration tank 21 is moved by the crane 3 as the driving means based on the received input and the tank position information or the calculation result by the program. Accordingly, the natural period can be adjusted by changing the amount of internal water in the open-type anti-vibration tank 21 according to the draft or sea condition, and an optimum anti-shake effect can be obtained according to the situation such as the draft or the sea condition. it can.

  Furthermore, if the fixing means for fixing the open type anti-vibration tank 21 to the floating body 1 is provided after the open type anti-vibration tank 21 is moved to an arbitrary position in the vertical direction, it is necessary to always suspend it by the crane 3. This is preferable. As a fixing means, the structure which can fix the floating body 1 and the open type anti-vibration tank 21 with a volt | bolt etc., the fastener etc. which regulate the vertical movement of the guide piece 23 by attaching to the guide rod 22 are used. Can do.

  FIG. 3 shows a state where the open-type anti-vibration tank 21 is withdrawn from the water in which the lower end side opening 24 is pulled up from the water. Thus, in the present embodiment, the open type anti-vibration tank 21 can be moved upward until the lower end side opening 24 is pulled up from the water and the open type anti-vibration tank 21 is removed from the water. It has become. Thereby, when navigating the floating body 1 by self-propulsion or towing, the open-type anti-vibration tank 21 is moved upward until the lower end side opening 24 is in a retracted state pulled up from the water. 2 (open type anti-vibration tank 21) can prevent an increase in resistance.

  Further, referring to FIG. 4, a door 70 is slidably provided in the lower end side opening 24 of the open type anti-vibration tank 21. The area of the lower end side opening 24 can be adjusted by sliding the door 70, and the natural period of the open type anti-vibration tank 21 can be set to a desired value by adjusting the area of the lower end side opening 24. It has become. If the area of the lower end side opening 24 is made smaller, the natural period of the open type anti-vibration tank 21 becomes longer, and if the area of the lower end side opening 24 is made larger, the natural period becomes shorter. Thereby, the natural period of the open type anti-vibration tank 21 can be appropriately set according to the wave period.

(Second Embodiment)
In the second embodiment, referring to FIG. 5, instead of the open type anti-vibration tank 21 of the first embodiment, an open type anti-vibration tank 40 having a telescopic structure that can expand and contract in the vertical direction is adopted. . The open type anti-vibration tank 40 includes an upper anti-vibration tank 41 having an upper end opening 25, a lower anti-vibration tank 42 having a lower end opening 24, an upper anti-vibration tank 41, and a lower anti-vibration tank 42. Is connected to the middle anti-vibration tank 43.

  The upper vibration reduction tank 41 is fixed to the floating body 1 by a fixing means (not shown). A wire 27 attached to the lower vibration reduction tank 42 is suspended by the crane 3 to move the lower vibration reduction tank 42 in the vertical direction. And it is configured to be stretchable. FIG. 5A shows an operating state in which the lower end side opening 24 of the lower vibration reduction tank 42 is submerged in water, and a vibration reduction effect can be obtained as in the first embodiment. FIG. 5 (b) shows a retracted state in which the lower end side opening 24 of the lower anti-shake tank 42 is pulled up from the water. Compared to the first embodiment, an open-type anti-shake tank in the retracted state is shown. The center of gravity of 40 can be kept low.

(Third embodiment)
In the third embodiment, referring to FIG. 6, a float member 50 is provided as internal water control means for controlling the state of internal water in the open type anti-vibration tank 21. By providing the float member 50 in the open type anti-vibration tank 21 and controlling the movement of internal water, the natural period of the open type anti-vibration tank 21 can be set to a desired value. That is, in the present embodiment, since the open type anti-vibration tank 21 is configured to be moved to the retracted state pulled up from the water, it is difficult to sufficiently secure the length of the open type anti-vibration tank 21. In that case, it becomes smaller than the natural period of the floating body 1, and there is a possibility that a sufficient vibration reduction effect cannot be obtained. Therefore, the float member 50 is provided in the open type anti-vibration tank 21 to control the movement of the internal water, and the natural period of the open type anti-vibration tank 21 is set to a desired value. Thereby, even if the length of the open type anti-vibration tank 21 cannot be ensured, a sufficient anti-vibration effect can be obtained.

  The size and weight of the float member 50 arranged in the open type anti-vibration tank 21 can be appropriately selected according to a desired natural period. Further, the float member 50 may only be floated in the open type anti-vibration tank 21, but the float member 50 may jump out of the upper end side opening 25. Therefore, as shown in FIG. It is preferable to provide a guide portion 51 such as a rail on the inner surface and move the float member 50 up and down within the range of the guide portion 51. The natural period of the open type anti-vibration tank 21 can also be adjusted by moving the float member 50 up and down. In addition, a configuration is provided so that a load is applied to the movement of the float member 50, for example, when the float member 50 moves along the guide portion 51, the float member 50 and the guide portion 51 or the inner surface of the open type anti-vibration tank 21 slide. By being configured to be moved, it is possible to obtain a vibration damping effect due to a load applied to the float member 50, for example, a sliding force.

  Furthermore, the movement of the float member 50 may be controlled, and the float member 50 position may be changed according to the situation such as the draft of the floating body 1 and sea conditions, for example, by the internal water control means. A certain float member 50 is configured as a hollow float body and moved in the vertical direction, thereby adjusting the posture of the floating body when it is inclined. Moreover, the anti-sway braking effect based on the spring property can also be obtained by configuring the float member 50, which is the internal water control means, with a flexible material having gas inside.

(Fourth embodiment)
In the fourth embodiment, referring to FIG. 7, there is provided a baffle plate 60 that functions as a resistance means for imparting frictional resistance to water entering and exiting the open type anti-vibration tank 21. By providing the baffle plate 60, it is possible to adjust the frictional resistance according to the speed of water entering and exiting the open type anti-vibration tank 21 and increase the anti-vibration braking effect. The baffle plate 60 is a plate erected in the open type anti-vibration tank 21. By configuring the resistance means with the baffle plate 60, the structure can be simplified, and the friction resistance can be increased by increasing or decreasing the number of the baffle plates 60. It becomes easy to adjust.

  Moreover, the water channel length of the internal water of the open type anti-vibration tank 21 is extended by providing a plurality of baffle plates 60 alternately. That is, in this embodiment, since the open type anti-vibration tank 21 is configured to be moved to the retracted state pulled up from the water, it is difficult to ensure the length of the open type anti-vibration tank 21, There is a possibility that it becomes smaller than the natural period of the floating body 1 and a sufficient vibration reduction effect cannot be obtained. Therefore, by arranging a plurality of baffle plates 60 alternately, the length of the internal water channel of the open type anti-vibration tank 21 is extended, and the natural period of the open type anti-vibration tank 21 is increased. Thereby, even if the length of the open type anti-vibration tank 21 cannot be ensured, a sufficient anti-vibration effect can be obtained. For the purpose of merely providing frictional resistance depending on the speed of water, not a baffle plate structure as described above, but, for example, a structure in which a plurality of plates having openings at the center are arranged or a rod-like protrusion is used. A structure in which a plurality of forests are built inside may be used.

(Fifth embodiment)
As shown in FIG. 8, the vibration reduction device 8 according to the fifth embodiment includes a plate-like base portion 82 that is attached so as to be vertically movable along a guide plate 81 provided on the heel side of the floating body 1, and a base portion 82. The first float plate 84 is pivotally connected to the lower portion of the first float 83 via the first hinge 83, and the second hinge 85 is connected to the open end of the first float plate 84. And a second float plate 86 that is pivotally connected about the second hinge 85 as an axis. Accordingly, the first float plate 84 and the second float plate 86 are supported so as to be movable in the up-down direction or the rotation direction with one end portion as an axis.

  FIG. 8A shows an operating state in which the base portion 82 is moved downward and the first float plate 84 and the second float plate 86 are exposed to the water surface. Thus, by causing the first float plate 84 and the second float plate 86 to face the water surface, a phase difference is generated between the floating body 1 and the wave period, and the energy of the wave is transferred to the first float plate 84 and the second float plate 84. Can be absorbed by the float plate 86, and a rocking effect can be obtained. It should be noted that the rotation of the shafts of the first float plate 84 and the second float plate 86, that is, the rotation of the first hinge 83 and the second hinge 85 is given friction, and the spring is used to apply a biasing force in the rotation direction. By attaching it, it is possible to enhance the anti-shake braking effect.

  In FIG. 8 (b), the cable 27 attached to the second hinge 85 is lifted by the crane 3 to pull up the first float plate 84 and the second float plate 86 from the water surface in an inverted V shape, A retracted state in which the base 82 is moved upward is shown. In the retracted state, when the floating body 1 is navigated by self-navigation or towing, the first float plate 84 and the second float plate 86 are lifted from the water surface until the floating body 1 is in the retracted state, thereby reducing the vibration reduction device. The increase in resistance due to 8 can be prevented. In addition, you may comprise so that the 1st float board 84 and the 2nd float board may be folded by pulling with the crane 3 by using the hinge 83 as a fixed axis | shaft at the time of withdrawal. In this case, the hinge 83 is preferably located above the water surface.

  Note that the present invention is not limited to the above-described embodiments, and it is obvious that the embodiments can be appropriately changed within the scope of the technical idea of the present invention. In addition, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment, and can be set to a number, position, shape, and the like that are suitable for implementing the present invention. In each figure, the same numerals are given to the same component.

DESCRIPTION OF SYMBOLS 1 Floating body 2 Vibration reduction device (1st Embodiment)
3 Crane (drive means)
8 Vibration reduction device (fifth embodiment)
21 Open Type Anti-Shock Tank 24 Opening on Lower Side 25 Opening on Upper Side 40 Open-type Shaking Tank (Second Embodiment)
41 Upper vibration reduction tank 42 Lower vibration reduction tank 43 Middle vibration reduction tank 50 Float member 60 Baffle plate (resistance means)
70 Door (opening adjustment means)
83 First hinge (shaft)
84 First float plate 85 Second hinge (shaft)
86 Second float plate

Claims (11)

A floating marine structure vibration reduction device that is mounted on a floating marine structure and reduces the fluctuation of the floating marine structure,
An open type anti-vibration tank that has a lower end side opening that functions as a water inlet / outlet on the lower end side and an upper end side opening that functions as an air inlet / outlet on the upper end side and extends in the vertical direction;
Driving means for driving the open type anti-vibration tank,
The open-type anti-vibration tank is supported so as to be movable in the vertical direction, and the vertical position can be controlled by the driving means according to the situation.   2. The apparatus for reducing a floating offshore structure according to claim 1, further comprising an opening area adjusting means for adjusting an area of the opening on the lower end side of the open type anti-vibration tank.   3. The apparatus for reducing a floating offshore structure according to claim 1, further comprising resistance means for imparting frictional resistance to water in the open type anti-vibration tank.   The open-type anti-vibration tank is movable by the driving means between an operating state in which the lower end opening is located in water and a retracted state in which the lower end opening is lifted from the water surface. 4. A rocking device for a floating offshore structure according to any one of 1 to 3.   5. The open-type anti-vibration tank is capable of adjusting a water depth at which the lower end side opening is located in an operating state in which the lower end side opening is located in water. A rocking device for floating offshore structures. A floating marine structure vibration reduction device that is mounted on a floating marine structure and reduces the fluctuation of the floating marine structure,
An open type anti-vibration tank that has a lower end side opening that functions as a water inlet / outlet on the lower end side and an upper end side opening that functions as an air inlet / outlet on the upper end side and extends in the vertical direction;
An internal water control means for controlling the state of the internal water in the open type anti-vibration tank,
A rocking device for a floating offshore structure, wherein the natural period in the open-type rocking tank can be controlled according to the size of the internal water control means.   7. The apparatus for reducing a floating offshore structure according to claim 6, wherein the internal water control means is controlled to move in the vertical direction in the open type anti-vibration tank. Comprising driving means for driving the open type anti-vibration tank;
The open-type anti-vibration tank can be moved by the driving means between an operating state in which the lower end side opening is located in water and a retracted state in which the lower end side opening is lifted from the water surface. Or a rocking device for floating offshore structure according to 7.   9. The reduction of the floating offshore structure according to any one of claims 1 to 5, wherein the position of the open type anti-vibration tank is controlled by the driving means according to draft or sea conditions. Rocking device. A floating marine structure vibration reduction device that is mounted on a floating marine structure and reduces the fluctuation of the floating marine structure,
A float board that absorbs the energy of waves by facing the water surface,
Driving means for driving the float plate,
The floating plate is supported so as to be movable in a vertical direction or a rotational direction with one end as an axis, and the position relative to the water surface can be controlled by the driving means according to the situation. Thing attenuator.   The said float board is movable to the operation state which faces the water surface with the said drive means, and the retracted state pulled up from the water surface, The rocking | fluctuation apparatus of the floating type marine structure of Claim 10 characterized by the above-mentioned.

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