Abstract:
The invention is for a mooring device ( 11 ) for a flap-gate breakwater ( 1 ) having a water blocking door body ( 2 ) that pivots about a horizontal axis. The mooring device ( 11 ) comprises a mooring hook ( 15 ) that controllably engages and disengages a gate mooring member ( 2   b ) of the door body ( 2 ) during mooring and raising operations. The mooring hook ( 15 ) is operated by a control device ( 21 ), making it possible to adjust the mooring hook position in a short period of time.

Description:
This application is a 371 application of PCT/JP2010/065145 having an international filing date of Sep. 3, 2010, which claims priority to JP2009-266451 filed Nov. 24, 2009, the entire content of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to a device which moors a door body of a flap-gate breakwater which is placed in a harbor as a countermeasure against high tide, for example. 
     BACKGROUND ART 
     In a flap-gate breakwater of the prior art, the door body was raised or lowered by buoyancy (e.g., Patent Reference 1). 
     The prior art flap-gate breakwater raised the door body by supplying air to a buoyancy chamber provided to the door body, thereby discharging sea water from the buoyancy chamber, so it needed an air supply device to supply air to the buoyancy chamber and discharge water from the buoyancy chamber. 
     However, in order to be able to supply compressed air during an electricity breakout, the prior art flap-gate breakwater constantly required a reservoir of compressed air in an accumulator tank. It was also necessary to constantly monitor the pressure of the accumulator tank, the overturning moment of the door body (weight of the end of the door body), and the angle of inclination of the door body, because the buoyancy chamber of the door body fills with sea water when it is being contained, and the door body rests in the containment position because of its weight. However, in this case, it is impossible to detect abnormalities such as the formation of holes in the buoyancy chamber due to corrosion or the like. Moreover, if the weight of the door body increases due to sediments or the like, maintenance becomes burdensome, since it is necessary to maintain buoyancy operations or dredging. 
     If a tsunami warning is sounded during an earthquake and a breakwater is raised, it can take a long time to raise the breakwater, because an air supply valve is opened to supply air to the buoyancy chamber and water is discharged from the buoyancy chamber based on levitation instructions, and this can occur too late to block the influx of a tsunami. 
     Accordingly, the applicants had previously disclosed a mooring device which constantly held a door body in a buoyant state in a flap-gate breakwater in which the door body rises due to buoyancy (Japanese Patent Application No. 2008-307699). 
     In this prior art mooring device for a flap-gate breakwater, an operation of a mooring hook positioned in the water was carried out, using a mooring rope operated from land. Therefore, in order to maintain secure mooring conditions, the position of the mooring hook had to be adjusted if the mooring rope was stretched due to the passage of time or by seasonal changes, and such an adjustment takes a long time. 
     In addition, if the mooring rope stretched and needed to be replaced, the operation of attaching the end of the rope to the mooring hook had to be carried out under water.
     Patent Reference 1: Japanese Patent Application Kokai Publication No. 2003-227125   

     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     The prior art problems to be solved by the present invention are: (1) It takes a long time to adjust the position of the mooring hook in response to changes in the mooring rope (stretching), in order to maintain secure mooring conditions; and (2) The operation of replacing the mooring hook must be carried out under water, because the mooring hook side of the mooring rope is under water. 
     Means for Solving these Problems 
     In order to avoid taking a long time to adjust the mooring hook position, and in order to avoid the operation of positioning the rope under water, the mooring device for a flap-gate breakwater according to the present invention provides a door body which has a plurality of sets of door body blocks arranged in a width direction, and is moored in a state of buoyancy, and is raised by releasing the mooring. 
     The mooring device according to the present invention comprises:
         a torque shaft disposed so as to freely rotate around a central axis, in a position opposite to a gate mooring member attached to the backside of the door body in a mooring state;   a mooring hook installed on the torque shaft to protrude in a position to engage with the gate mooring member;   a counterweight attached to the torque shaft for rotating the torque shaft in a direction to release the mooring hook from engaging with the gate mooring member;   a first link member disposed, in a containment structure which moors the door body under water, on a portion opposite to the backside of the door body in a mooring state;   a second link member disposed in the containment structure on the outer side of one end side of the backside of the door body in the mooring state;   a rod member having one end connected in a position toward the other end of a torque arm with one end attached to the torque shaft, and having the other end pulled above the surface of the water via the two link members;   a hook attaching and detaching cylinder device disposed near the other end of the rod member and having a pulley attached to the front end of a piston rod;   a wire member, one end of which is connected to the other end of the rod member, and the other end of which is connected via a pulley to a spring device which expands and contracts together with the oscillation of the door body; and   a first vertical rod forming the rod member, one end of which pivots at a position toward the other end of the torque arm, and the other end of which pivots at the one end of the first link member, and the first vertical rod having a slot at one end and a spherical bushing at the other end, wherein when it is time to activate mooring of the door body, while oscillating around the spherical bushing oscillating as a supporting point, a pin attached to a position toward the other end of the torque arm is allowed to move along the slot to accommodate vertical movements of the mooring hook, from the time when the gate mooring member starts to press down on the front end of the mooring hook, until the time when the front end of the mooring hook crosses the gate mooring member.       

     The present invention makes it possible to compensate for stretching of the rod member by raising and lowering the wire member which connects a spring device which expands and contracts together with the oscillation of the door body to the other end of the rod member which is used instead of a mooring rope, via a pulley attached to the front end of the piston rod of the hook attaching and detaching cylinder device. 
     Advantageous Effects of the Invention 
     The present invention makes it possible to compensate if stretching occurs in the rod member by raising and lowering the wire member which connects a spring device which expands and contracts together with the oscillation of the rod member and the door body, via a pulley attached to the piston rod of the hook attaching and detaching cylinder device. 
     In addition, the mooring operation can be carried out with only a mooring hook and a counterweight, due to the fact that a slot is provided at one end of the first vertical rod which connects the torque arm and the first link member, and the spherical bushing is provided at the other end. Thus, there is no longer a need for a series of actions pertaining to the mooring operation to be performed by a device located on land, and it is possible to reduce the stroke of the hook attaching and detaching cylinder device. Moreover, there is no need to move the link members and the rod members with a counterweight, because a series of mooring operations can be carried out irrespective of the link members and the rod members, thereby making it possible to reduce the weight of the counterweight. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  ( a ) is a schematic diagram illustrating a state when a flap-gate breakwater equipped with the mooring device of the present invention is in a lowered state during mooring; ( b ) is an expanded view of the front end portion of the door body 
         FIG. 2  is a schematic diagram illustrating a state when a flap-gate breakwater is disposed continuously along the width of a harbor, where ( a ) is a perspective view in which a tension rod is omitted, and ( b ) is a side view. 
         FIG. 3  is a drawing illustrating the interval between the top end of the door body and the containment structure, and the opening width of both ends of the door body block, where ( a ) is a side view, and ( b ) is an elevation view. 
         FIG. 4  is a detailed drawing of the mooring device, where ( a ) is a perspective view illustrating the configuration of the containment structure side, and ( b ) is a detailed drawing illustrating the configuration of the control device side. 
         FIG. 5  is a schematic diagram illustrating the state of the mooring device when there is provided a plurality of first link members. 
         FIG. 6  ( a ) is a drawing illustrating the state of the mooring device during the mooring preparation operation, and ( b ) is a view along the line A-A in ( a ). 
         FIG. 7  ( a ) is a drawing illustrating the state of the mooring device after completion of the mooring preparation operation, and ( b ) is a view along the line A-A in ( a ). 
         FIG. 8  is a drawing illustrating a specified stroke magnitude in the mooring preparation operation. 
         FIGS. 9  ( a )-( c ) are drawings which sequentially illustrating the relative positions of the mooring hook and the gate mooring pin, as the door body is lowered. 
         FIG. 10  ( a ) is a drawing illustrating the state of the mooring device when mooring is completed, and ( b ) is a drawing illustrating the relative position of the mooring hook and the gate mooring pin as viewed from the direction A-A in ( a ). 
         FIG. 11  ( a ) is a schematic diagram illustrating the state of the mooring device when the mooring of the door body is released, and ( b ) is a view along the line A-A in ( a ). 
         FIG. 12  is a diagram illustrating the mooring force required when the door body is allowed to oscillate. 
         FIG. 13  is a diagram illustrating the mooring force required to keep the door body in a lowered state. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the present invention, the object of adjusting the position of the mooring hook in a short period of time is achieved by raising and lowering the wire member which connects the rod member and the spring device which expands and contracts together with the oscillation of the door body, via the pulley attached to the piston rod of the hook attaching and detaching cylinder device. 
     Example 
     The present invention is described in detail with an example below, using  FIG. 1  to  FIG. 13 . 
       FIG. 1  is a schematic diagram illustrating a state when a flap-gate breakwater equipped with the mooring device of the present invention is in a lowered state during mooring. 
     In  FIG. 1 , Reference Numeral  1  is a flap-gate breakwater, equipped, for example, with a door body  2  and a plurality of tension rods  3  provided on the outer side of a harbor R, so that the door body  2  will not tip while the door body  2  is being raised. 
     If the door body  2  is placed in the waters of a wide harbor, a plurality of laterally arranged sets forming a door body block B is provided in a row at fixed intervals, with the members of the door body block B being adjacent and connected to each other with a rope, as shown in  FIG. 2  ( a ). 
     In the case of the door body  2 , a door body block unit is measured from the center of one of adjacent door bodies B to the center of the other of the adjacent door bodies, and the value of the width of the door body block B subtracted from the width of the door body block unit is an opening width d 1  of the two side end parts of the adjacent two door body blocks B, as shown in  FIG. 3  ( b ). 
     The opening width d 1  of the two side end parts of the adjacent two door body blocks B, is basically 1% of the width of the door body block B, so that when the flap-gate breakwater  1  serves as a tsunami-blocking countermeasure, the amount of water which leaks into the harbor during a tsunami is not too great. The size of opening width between the adjacent door body blocks B is (d 1 /2)×2=d 1 , because the door body block units are arranged in a row at fixed intervals, and is 1% of the width of the door body block B. If the opening width d 1  of the two side end parts of the door body block B is too small, there arises a problem that foreign matter can get caught therein. 
     The door body  2  has a rotating shaft  2   a  on the base end side, which is supported by a bearing  5 , so as to freely rotate on a base  4   a  of a containment structure  4  which is provided as an integral structure at the bottom of the harbor R, and the rotating shaft  2   a  serves as a supporting point for raising and lowering the door body  2 . 
     In order to facilitate a smooth raising and lowering operation, an interval d 2  is also provided between the top end of the door body  2  and the containment structure  4 , as shown in  FIG. 3  ( b ). Accordingly, as shown in  FIG. 3  ( a ), the space S 1  above the door body  2  in the lowered position and the space S 2  below the door body  2  in the lowered position communicate with each other by means of the opening width d 1  of the two side end parts of the adjacent two door body blocks B and the interval d 2  between the top end of the door body block B and the containment structure  4 . 
     The tension rod  3  is formed so as to fold into two, due to a connecting member  3   a  disposed in the middle thereof. One end part  3   b , which is positioned at the upper end side when the door body  2  is raised, is supported for rotation at the upper end of the door body  2 , and the other end part  3   c , which is positioned at the lower end side when the door body  2  is raised, is supported for rotation at a position separated only by a specified distance from the rotating shaft  2   a  on the side where the door body  2  is lowered. 
     The door body  2  is provided with a buoyancy chamber  2   b  on the upper end side thereof, for example, and is constructed to produce the buoyancy required to raise the door body  2 , by supplying air to the buoyancy chamber  2   b  by means of an air supply device (receiver tank and compressor) which is not depicted in the drawings. 
     Reference Numeral  11  is a mooring device of the present invention which has, for example, the structure illustrated in  FIG. 4 , and which moors the door body  2  under the water in a state in which it has buoyancy. 
     Reference Numerals  12  and  13  are first and second bell crank link members, and the first link member  12  is disposed on a portion opposite to the backside  2   c  of the door body  2  in a lowered state in a containment structure  4  which moors the door body  2  under water as shown in  FIG. 1  ( a ). The second link member  13  is disposed on the outer side of one end of the backside  2   c  of the door body  2  in a lowered state in the containment structure  4 , at a part opposite to the backside  2   c  of the door body  2  in a lowered state while being contained. 
     Reference Numeral  14  is a torque shaft which freely rotates around the central axis, and is disposed in a position opposite to a gate mooring member  2   d  attached to the top end side (the upper end side of the door body  2  when it is raised), for example, on the backside  2   c  of the door body  2  in a mooring state. A mooring hook  15  is attached in a protruding state in a position to engage with the gate mooring member  2   d  of the torque shaft  14 . 
     Reference Numeral  16  is a counterweight which is connected to the mooring hook  15  protruding to the opposite side of the torque shaft  14 , and causes the torque shaft  14  to rotate in a direction which frees the mooring hook  15  from engagement with the gate mooring member  2   d.    
     Reference Numeral  17  is a rod member having one end connected to the other end of a torque arm  18  having on end attached in a position in the center in the axial direction of the torque shaft  14 , and having the other end pulled above the surface of the water via the first link member  12  and the second link member  13 . 
     The rod member  17  is formed from a first vertical rod  17   a , a horizontal rod  17   b , and a second vertical rod  17   c.    
     The first vertical rod  17   a  is provided with a slot  17   aa  at one end, and a pin  18   a  provided in a position toward the other end of the torque arm  18  is inserted into the slot  17   aa . A spherical bushing  17   ab  is provided at the other end, is supported to rotate freely at one end part  12   a  of the first link member  12 . 
     The horizontal rod  17   b  has one end which is supported to rotate freely at the other end part  12   b  of the first link member  12  and the other end which is supported to rotate freely at one end  13   a  of the second link member  13 . If there is a plurality of first link members  12 , the horizontal rod  17   b  is supported to rotate freely at the other end part  12   b  of the plurality of first link members  12 , and the other end of the horizontal rod  17   b  is supported to rotate freely at one end  13   a  of the second link member  13  (see  FIG. 5 ). 
     The second vertical rod  17   c  has one end which is supported to rotate freely at the other end part  13   b  of the second link member  13 , and the other end is pulled above the surface of the water and is connected to a control device  21  having the structure given below. 
     Reference Numeral  19  is an operation restriction stopper provided on the rotational pathway of one end part  12   a  of the first link member  12 , and one end part  12   a  of the first link member  12  comes in contact with the operation restriction stopper  19  to restrict the operating range of the first link member  12  (see  FIG. 8 ). 
     Reference Numeral  22  is a hook attaching and detaching cylinder device for attaching and detaching the mooring hook  15  to the gate mooring member  2   d , and is disposed near the other end of the second vertical rod  17   c . The hook attaching and detaching cylinder device  22  has a pulley  23  attached to the front end of a piston rod  22   b  which projects into and retracts from a cylinder  22   a  with a fixed bottom. 
     Reference Numeral  24  is a wire member wound around the pulley  23 , and one end thereof is connected to the other end of the second vertical rod  17   c  via a load cell  25 , and the other end thereof is connected to a device such as a spring device  26  which expands and contracts together with the oscillation of the door body  2 . A spring used in the spring device  26  is a coil spring having a slender metal wire wrapped in a spiral. The wire member  24  does not have to be replaced under water when it stretches, since this can be accomplished on land. 
     The hook attaching and detaching cylinder device  22  is provided with a stroke sensor  22   c  for detecting the amount of projection and retraction of the piston rod  22   b . The spring device  26  is also provided with a stroke sensor  26   a  and a stroke indicator for measuring the stroke of the spring. 
     In the case of the mooring device  11  constructed as described above, when waves pass over the door body  2  moored in the containment structure  4 , oscillations caused by buoyancy generated in the door body  2  cancel out the wave force allowed by the expansion and contraction of the spring device  26 . 
     The flap-gate breakwater  1  described above moors the door body  2  and releases it from mooring by the operation described as follows. 
     Mooring Preparation Operation: See  FIG. 6-FIG .  8   
     The piston rod  22   b  of the hook attaching and detaching cylinder device  22  is activated, and one end part  12   a  of the first link member  12  is caused to make contact with the operation restriction stopper  19  (see  FIG. 6 ) 
     Then, while monitoring the stroke sensor  26   a  of the spring device  26  or the load cell  25 , the piston rod  22   b  of the hook attaching and detaching cylinder device  22  is activated until a mooring force operates that is equivalent to when the standard buoyancy operates when the door body  2  is moored. The stroke position of the piston rod  22   b  of the hook attaching and detaching cylinder device  22  at that time is detected by the stroke sensor  22   c , and is recorded as the standard position. A mooring force which is equivalent to when the standard buoyancy operates when the door body  2  is moored is referred to below as the specified mooring force. 
     At this time, the link members among the control device  21  from the operation restriction stopper  19  and a spring device system are in a stretched state equivalent to the specified mooring force. The spring device system refers to the first link member  12 , the rod members  17   b ,  17   c , the second link member  13 , the load cell  25 , the wire member  24 , and the spring device  26 . 
     The relative positional relationship between the first link member  12  and the mooring hook  15  is then understood. Therefore, the piston rod  22   b  of the hook attaching and detaching cylinder device  22  is withdrawn by an amount corresponding to the specified stroke, in the position of the first link member  12  in the standard position recorded as above (see  FIG. 8 ). The amount corresponding to the standard stroke refers to an amount from when the first link member  12  is in a position (imaginary line) touching the operation restriction stopper  19  to the relative position when the mooring hook  15  is in a horizontal state (solid line). 
     In the above state, when the piston rod  22   b  of the hook attaching and detaching cylinder device  22  is withdrawn by the amount corresponding to the standard stroke, first, the stretched link members and the spring device system contract. After that, one end part  12   a  of the first link member  12  separates from the operation restriction stopper  19 . The mooring hook  15  reaches a position inclining downward from the horizontal position, in an amount corresponding to the contraction of the link members and the spring device system (see  FIG. 7 ). This completes the mooring preparation operation. 
     Mooring Operation:  FIG. 9-FIG .  10   
     Upon completion of the above mooring preparation operation, an exhaust valve provided to the upper end of the door body  2  is opened, air is removed from the buoyancy chamber  2   b , sea water enters the buoyancy chamber  2   b , and the door body  2  is lowered. 
     With the lowering of the door body  2 , the gate mooring member  2   d  provided to the door body  2  pushes down on the mooring hook  15 , and at the same time, the pin  18   a  of the torque arm  18  moves toward the lower part of the slot  17   aa  of the first vertical rod  17   a  (see  FIG. 9  ( a )- 9  ( b )). Meanwhile, movement along the slot  17   aa  of the pin  18   a  of the torque arm  18  is accomplished smoothly, because the first vertical rod  17   a  oscillates as a supporting point for the spherical bushing  17   ab.    
     When the gate mooring member  2   d  of the door body  2  passes the mooring hook  15 , the mooring hook  15  crosses the gate mooring member  2   d , due to the weight of the counterweight  16 , and returns from the horizontal state to a position inclined slightly downward ( FIG. 9  ( c )). 
     After lowering is completed, compressed air is supplied to the buoyancy chamber  2   b , and sea water is expelled from the buoyancy chamber  2   b . Consequently, the door body  2  rises, and the gate mooring member  2   d  pushes the mooring hook  15  upward, transmitting the buoyancy of the door body  2 . At the same time, the rod member  17 , the first link member  12 , the second link member  13 , the wire member  24 , and the spring device  26  are stretched and displaced by the mooring force resulting from the buoyancy of the door body  2 . The mooring hook  15  moves upward by the amount of displacement ( FIG. 10 ). 
     Then, the stroke sensor  26   a  of the spring device  26  or the load cell  25  is monitored to confirm that the specified mooring force is in operation, and the supply of air to the buoyancy chamber  2   b  is stopped. When this happens, the mooring hook  15  reaches a horizontal state. 
     The stroke of the hook attaching and detaching cylinder device  22  can be reduced, because the control device  21 , which is provided on land, no longer needs to operate with regard to the series of mooring operations described above. Additionally, the weight of the counterweight  16  can be reduced, because there is no need to operate the link members  12 ,  13  and the rod member  17  by means of the counterweight  16 . 
     Furthermore, in cases where the rod member  17 , the first link member  12 , and the second link member  13  have undergone changes such as stretching, deflecting, or the like, if the above-described series of mooring preparation operations are performed each time prior to the mooring operation, the position of the mooring hook  15  can be kept constant, without visually checking the position of the mooring hook  15  when it is under water, thereby making it possible to always maintain a normal mooring state. 
     During the Operation of Raising the Door Body  2 : See  FIG. 11   
     When the hydraulic pressure of the hook attaching and detaching cylinder device  22  is released, the holding force is relaxed. Consequently, the mooring force of the mooring hook  15  is relaxed via the second vertical rod  17   c , the second link member  13 , the horizontal rod  17   b , the first link member  12 , the first vertical rod  17   a , and the torque arm  18 . Therefore, the mooring hook  15  is pushed upward by the buoyancy of the door body  2  and the force of the counterweight  16 , releasing engagement with the gate mooring member  2   d.    
     After that, it is confirmed that the spring device  26  has contracted, and the load cell  25  confirms that there is no mooring force. 
     In the flap-gate breakwater  1  described above, oscillation of the door body  2  is allowed by the spring device  26 , so that mooring is performed. In this case, negative pressure occurs in the space S 2  on the lower side of the door body  2 , as a result of the upward displacement of the door body  2 , generating a force which operates downward on the door body  2  as a result of the difference in pressure vis-à-vis the upper surface of the door body  2  (see  FIG. 12 ). 
     Accordingly, the load required to moor the door body  2  is less than in the case where mooring is accomplished when the door body  2  whose the mooring mechanism must entirely bear the operating load in the form of momentum around the rotating shaft  2   a  of the door body  2  generated by a wave is fixed in place (see  FIG. 13 ). 
     The present invention is not limited to the above-described example, and the preferred embodiment may, of course, be advantageously modified within the scope of the technical ideas recited in the claims. 
     EXPLANATION OF THE REFERENCE SYMBOLS 
     
         
         
           
             B Door body block 
               1  Flap-gate breakwater 
               2  Door Body 
               2   a  Rotating shaft 
               2   b  Buoyancy chamber 
               2   c  Backside 
               2   d  Gate mooring member 
               4  Containment structure 
               5  Bearing 
               11  Mooring device 
               12  First Link member 
               13  Second Link member 
               14  Torque shaft 
               15  Mooring hook 
               16  Counterweight 
               17  Rod member 
               17   a  First Vertical rod 
               17   aa  Slot 
               17   ab  Spherical bushing 
               17   b  Horizontal rod 
               17   c  Second Vertical rod 
               18  Torque arm 
               19  Operation restriction stopper 
               22  Hook attaching and detaching cylinder device 
               22   b  Piston rod 
               23  Pulley 
               24  Wire member 
               26  Spring device