JP2022001698A - Flap gate - Google Patents

Abstract

To provide a flap gate capable of securing a large gap between a door body and a bottom of a water gate without arranging any substrate step in a state no external force except gravitation force acts as well as securing water tightness with an opening of the water gate upon closing.SOLUTION: A flap gate is provided with an open/close operation support mechanism 8 lifting a gap open/close member 7 in an open direction when a door body 2 is opened at an initial angle or more, swinging the gap open/close member 7 in association with the door body 2 when the door body 2 swings within an opening range less than the initial angle, and abutting the gap open/close member 7 to a gate guide 9 of an opening 200 when the door body 2 closes the opening 200 of a water gate 100.SELECTED DRAWING: Figure 1

Description

The present invention relates to a flap gate provided with a flap-type door body for opening and closing the opening of a floodgate.

Conventionally, gutter gates and floodgates installed on rivers, lakes, coasts, etc. are provided with gates to prevent backflow due to floods and storm surges. As an example of a gate that opens and closes the opening of the water gate, there is a pull-up gate that opens the water gate opening by pulling up the door body. Generally, a rack-type elevator is used to raise and lower the door body. Normally, the water gate opening is opened, and the water flowing from the upstream side (inner water side) is drained to the downstream side (outer water side). If the water level on the downstream side rises and a backflow to the upstream side occurs, the operator goes to the floodgate and performs a closing operation. On the other hand, if the water level on the downstream side becomes low, the opening operation of the floodgate is performed again. As described above, the pull-up gate needs to be operated according to the water level, and there is a problem of securing personnel for the operation.

On the other hand, the applicant of the present application has so far developed and obtained a patent right for a flap gate capable of automatically opening and closing the water gate opening according to the water levels on the upstream side and the downstream side (Patent Document 1). ). At the opening of the water gate where the flap gate is installed, a rectangular door stop is installed in close contact with the watertight rubber installed on the upstream side surface of the door body to ensure watertightness. In this case, in order to install a door stop on the bottom surface of the water gate opening, a step (also referred to as a "bed step") is provided on the downstream side so as to be lowered one step. The flap gate forms a gap between the door contact surface of the floor step and the door body by inclining the door body by several degrees to ten and several degrees, and drains water from the upstream side. It is designed to be done smoothly.

Focusing on the advantages of such flap gates, in recent years, there is an increasing need to repair the flap gates in order to solve the problems of the pull-up gates.

However, the bottom surface of the sluice gate opening where the pull-up gate was installed is in a flat state, and no step is provided. For this reason, when the flap gate is installed in a sluice gate without a sluice step and the door body is tilted by several degrees to a dozen degrees as in the case of a sluice step, the lower end of the door body and the bottom surface of the sluice gate opening Only a small gap is formed between them. Therefore, even if the water level on the upstream side is low, drainage may be hindered. On the other hand, a method of increasing the inclination angle of the door body to increase the gap with the bottom surface is also conceivable, but in a situation where the water level on the downstream side rises and a backflow occurs, the door body is automatically closed by water pressure. The water level required for this is also high. That is, the reaction of automatically closing due to the water pressure on the downstream side is delayed. Therefore, conventionally, in the work of renovating from a pull-up gate to a flap gate, it is necessary to provide a step on the water gate side when installing the flap gate.

In order to solve the technical problem when repairing such a flap gate, the applicant of the present application previously used the weight of the external float installed on the downstream side of the door body to install the door body in the water gate without a step. We have developed and obtained a patent right for a flap gate that can be lifted greatly and the door body can be closed smoothly by the buoyancy that accompanies the rise in water level (Patent Document 2).

Japanese Patent No. 3500288 Japanese Patent No. 5905152

However, even in the invention described in Patent Document 2, it may be difficult to install an external float depending on the installation location of the floodgate, the surrounding environment, the structure of the floodgate, and the like. Therefore, there has been a need to develop a new flap gate that can be installed even when there is no step and it is difficult to install an external float.

The present invention has been made to solve the above problems, and in a state where an external force other than gravity is not applied, a gap between the door body and the bottom surface of the floodgate is provided without providing a step. The purpose is to provide a flap gate that can be made large and can ensure watertightness with the opening of the floodgate when closed.

In the flap gate according to the present invention, a gap is provided between the door body and the bottom surface of the water gate without providing a step, the gap is opened and closed in conjunction with the inclination angle of the door body, and the opening of the water gate is closed. In order to solve the problem of ensuring watertightness with the opening when the door is closed, the flap type door body is suspended at a predetermined initial angle in a state where no external force other than gravity is applied. A flap gate that opens and closes the opening of the water gate, and has a predetermined distance between the lower end edge of the door body and the bottom surface of the water gate in a state where the door body closes the water gate. The door is installed so as to form a gap, and a gap opening / closing member that swings with the lower end edge as a fulcrum to open / close the gap is provided at the lower end edge of the door body. When the body is opened at the initial angle or more, the gap opening / closing member is pulled up in the opening direction, and when the door body is swinging within the opening range less than the initial angle, the gap opening / closing member is pulled up at the door body. When the door body closes the opening of the water gate, the door body is provided with an opening / closing operation assisting mechanism for bringing the gap opening / closing member into contact with the door contact of the opening.

Further, as one aspect of the present invention, in order to solve the problem of configuring the opening / closing operation assisting mechanism based on the link mechanism, the opening / closing operation assisting mechanism is provided at a position different from the door body support shaft of the door body. A link arm in which a downstream arm and an upstream arm are alternately supported so as to be vertically movable with the arm rotation axis as a fulcrum, and a link connecting the downstream arm of the link arm and the gap opening / closing member. A rod, an opening / closing auxiliary weight provided on the upstream arm of the link arm, and an arm that stops the rotation of the link arm when the door body swings within an opening range less than the initial angle. It may have a stopper.

Further, as one aspect of the present invention, in order to solve the problem of improving the operability of the gap opening / closing member by the opening / closing assist weight, the link arm has a length from the arm rotation shaft to the position of the center of gravity of the opening / closing assist weight. The length may be longer than the length from the arm rotation shaft to the connection position of the link rod.

Further, as one aspect of the present invention, in order to solve the problem of improving the opening / closing operability of the gap opening / closing member by the opening / closing operation assist mechanism, the connection position of the downstream side arm with the link rod is set to the arm rotation shaft. It may be configured to be located higher.

Further, as one aspect of the present invention, in order to solve the problem of facilitating closing the gap between the lower end edge of the door body and the bottom surface of the water gate, the lower end corners of the left and right side door stops in the door stop are provided. May be provided with an opening / closing member receiving portion that comes into contact with the gap opening / closing member when the door body is in a state of closing the opening.

According to the present invention, in a state where an external force other than gravity is not applied, a large gap can be taken between the door body and the bottom surface of the water gate without providing a step, and when the door is closed, the gap between the door body and the bottom surface of the water gate can be widened. Watertightness can be ensured.

It is a front side perspective view which shows one Embodiment of the flap gate which concerns on this invention. It is a right side view which shows the state which the door body in this embodiment closes a water gate. It is the back side partially enlarged perspective view which shows the state around the door body support shaft in this embodiment. It is a partially enlarged right side view which shows the gap opening / closing member in this embodiment. It is a right side view which shows the opening / closing operation assist mechanism in the state which the door body is suspended at an initial angle in this embodiment. It is a partially enlarged perspective view on the back side which shows the opening / closing operation assist mechanism in this embodiment. It is a front side partially enlarged perspective view which shows the opening / closing operation assist mechanism in this embodiment. It is a front side partially enlarged perspective view which shows the connection state of the link rod of the opening / closing operation assist mechanism and the gap opening / closing member in this embodiment. It is a right side view which shows (a) the distance between each structure in the flap gate of this embodiment, and (b) is a schematic diagram which shows the said distance. It is a right side view of (a) opening and closing operation assisting mechanism in a state where a door body is inclined at 90 degrees in this embodiment, and (b) is a schematic diagram which shows the distance between each structure. It is a right-angle view of (a) the right side view of the opening / closing operation assisting mechanism, and (b) the schematic diagram which shows the distance between each structure in the state which the door body in this embodiment is inclined in the range from the initial angle or more but less than 90 degrees. It is a schematic diagram which shows (a) the right side view of the opening / closing operation assisting mechanism, and (b) the distance between each structure in the state which the door body in this embodiment is inclined in the range which is less than an initial angle and is more than 0 degree. .. FIG. 3 is a right side view of (a) an opening / closing operation assisting mechanism and (b) a schematic view showing a distance between each configuration in a state where the door body is tilted to 0 degrees (closed state) in the present embodiment.

Hereinafter, an embodiment of the flap gate according to the present invention will be described with reference to the drawings.

The flap gate 1 of the present embodiment automatically opens and closes the opening 200 of the water gate 100 according to the weight balance and water pressure of the axially supported door body 2, and as shown in FIG. 1, the opening 200 is opened and closed. A door body 2 that opens and closes, a door body support arm 3 that supports the door body 2, a door body support shaft 4 that connects the door body support arm 3 to swingably support the door body 2, and a door body support shaft 4. A weight arm 5 connected to the door body support shaft 4, a balance weight 6 provided at the upper end of the weight arm 5, and a lower end edge portion 21 of the door body 2 and a bottom surface 300 of the water gate 100 are formed. The gap opening / closing member 7 that opens / closes the gap C, the opening / closing operation assist mechanism 8 that swings the gap opening / closing member 7 in conjunction with the angle (opening) of the door body 2, and the opening 200 of the water gate 100. It has 9 per door to be installed. Hereinafter, each configuration will be described in detail.

The door body 2 is a door that opens and closes the opening 200 of the water gate 100, and in the present embodiment, it is formed in a rectangular shape according to the shape of the opening 200. As shown in FIG. 2, the door body 2 is formed to have a left-right width larger than the left-right width of the opening 200 so that the opening 200 can be closed. The upper end side is installed so as to be located above the upper edge portion of the opening 200 in a state where the opening 200 is closed. On the other hand, the lower end side is installed so that a gap C at a predetermined interval is formed between the lower end edge portion 21 and the bottom surface 300 of the floodgate 100 in a state where the opening 200 is closed. Further, on the back surface (upstream side surface) of the door body 2 in the present embodiment, a float 22 that generates buoyancy when submerged is provided.

The door body support arm 3 is an arm that supports the door body 2, and in the present embodiment, the two door body support arms 3 and 3 extend continuously upward from the downstream side surface of the door body 2. It is provided in.

The door body support shaft 4 is a shaft for swingably supporting the door body 2 in the water flow direction, and in the present embodiment, as shown in FIG. 3, it is installed above the opening 200 of the water gate 100. The bearing 400 is rotatably provided. A door body support arm 3 is fixed to the door body support shaft 4, and the door body 2 supported by the door body support arm 3 is swingably supported.

The weight arm 5 is an arm for installing the balance weight 6 at the upper end, and in the present embodiment, the weight arm 5 extends in the direction opposite to the door body support arm 3 with the door body support shaft 4 as the base end.

The balance weight 6 is for adjusting the weight balance that sets the initial opening degree of the door body 2, and is installed at the upper end of the weight arm 5. The balance weight 6 in the present embodiment is adjusted to a weight that allows the door body 2 to be balanced at a predetermined initial angle in a state where no external force other than gravity is applied. Here, the initial angle is set as the angle formed by the downstream side surface of the door stop 9 and the upstream side surface of the door body 2 in the present embodiment. By setting the initial angle and increasing the gap provided between the gap opening / closing member 7 and the bottom surface 300 of the floodgate 100, the water level on the downstream side is low and no backflow to the upstream side occurs. Drainage is done smoothly.

The initial angle is not particularly limited, and is preferably about 5 to 20 degrees, preferably about 8 degrees to 15 degrees, depending on the shape of the gap opening / closing member 7, the amount of drainage from the upstream side, the water level at the time of drainage, and the like. The degree is more preferable, and in this embodiment, it is set to about 11 degrees. Further, the weight balance that supports the door body 2 at the initial angle may be adjusted by the positional relationship between the position of the center of gravity of the door body 2 and the support position of the door body support shaft 4 without using the balance weight 6.

Next, the gap opening / closing member 7 will be described. The gap opening / closing member 7 swings around the lower end edge portion 21 of the door body 2 as a fulcrum to open / close the gap C formed between the lower end edge portion 21 and the bottom surface 300 of the water gate 100. As shown in FIG. 4, the gap opening / closing member 7 in the present embodiment is provided on both front and rear surfaces of the opening / closing member main body 71 made of a rubber material having flexibility in order to improve watertightness and the opening / closing member main body 71. It has a reinforcing plate 72 and a hinge 73 that serves as a fulcrum for swingably supporting the lower end edge portion 21 of the door body 2.

The opening / closing member main body 71 is a main body portion of the gap opening / closing member 7, and has a size capable of covering the gap C. The opening / closing member main body 71 in the present embodiment is formed of a rubber material having flexibility that can be deformed along the door stop 9 and the bottom surface 300 in order to improve the watertightness with the door stop 9 and the bottom surface 300 of the floodgate 100. ing. Further, the lower end portion has a bulging portion 74 that is bulged in order to increase the wall thickness and increase the strength. Further, the upper end portion has a fixing block 75 formed in a prismatic shape along the lower end edge portion 21 of the door body 2 for fixing to the lower end edge portion 21 of the door body 2. The fixing block 75 in the present embodiment is integrally formed of the same material as the opening / closing member main body 71.

The reinforcing plate 72 is a plate material for reinforcing the opening / closing member main body 71, and is for preventing the opening / closing member main body 71 from being deformed and unable to maintain watertightness due to the water pressure received when the gap C is closed. The reinforcing plates 72 in this embodiment are provided on both front and rear surfaces of the opening / closing member main body 71. The reinforcing plate 72b on the rear side (upstream side) is formed to be one size smaller than the opening / closing member main body 71 so as to avoid the contact portion between the opening / closing member main body 71 and the door stop 9 and the bottom surface 300 of the floodgate 100. The pair of front and rear reinforcing plates 72 in the present embodiment are arranged on both front and rear surfaces of the opening / closing member main body 71, and are fastened and fixed by bolts and nuts in a sandwiched state.

The reinforcing plate 72 is not limited to the one provided on the front and rear surfaces, and may be provided on only one surface or may be built in the opening / closing member main body 71. Further, if the opening / closing member main body 71 has a strength that can withstand water pressure, the reinforcing plate 72 may not be provided.

The hinge 73 is for stabilizing the operation when the opening / closing member main body 71 is swung around the lower end edge 21 of the door body 2 as a fulcrum, and the two plate members 76a and 76b are rotatable by the shaft member. It has a connected structure. As shown in FIG. 4, one of the plate members 76a of the hinge 73 in the present embodiment is fixed to the front surface side (downstream surface side) of the opening / closing member main body 71. The other plate material 76b is fitted into a slit 77 formed in the fixing block 75, and is fixed to the lower end edge portion 21 of the door body 2 together with the fixing block 75. As shown in FIG. 1, the hinge 73 is provided at a total of three positions, a center position with respect to the left and right of the lower end edge portion 21 and a left and right target position with respect to the center position.

The number of hinges 73 is not particularly limited, and may be appropriately selected based on the strength of the opening / closing member main body 71 and the like.

The opening / closing operation assist mechanism 8 is for swinging the gap opening / closing member 7 according to the opening degree of the door body 2, and when the door body 2 is opened at an initial angle or more, the gap opening / closing member 7 is opened in the opening direction. When the door body 2 swings within the opening range less than the initial angle, the gap opening / closing member 7 swings in conjunction with the door body 2, and the door body 2 closes the opening 200 of the water gate 100. It has a function of bringing the gap opening / closing member 7 into contact with the door stop 9 of the opening 200.

As shown in FIGS. 5 to 8, the opening / closing operation assist mechanism 8 of the present embodiment operates the gap opening / closing member 7 by a link mechanism, and is provided at a position different from the door body support shaft 4 of the door body 2. A link arm 81 pivotally supported with the arm rotation shaft 82 as a fulcrum, a link rod 83 connecting the link arm 81 and a gap opening / closing member 7, and an opening / closing auxiliary weight 84 provided on the link arm 81. It has an arm stopper 85 that stops the rotation of the link arm 81.

The link arm 81 is a member that swings according to the angle of the door body 2 when the gap opening / closing member 7 is operated, and is pivotally supported with the arm rotation shaft 82 as a fulcrum as shown in FIG. The link arm 81 in the present embodiment is installed in the vicinity of the left and right bearings 400 that pivotally support the door body support shaft 4.

Further, the link arm 81 in the present embodiment extends to the downstream side and the upstream side with the arm rotation shaft 82 as a fulcrum, and is configured as a downstream side arm 81a on the downstream side and an upstream side arm 81b on the upstream side. There is. Therefore, the downstream side arm 81a and the upstream side arm 81b can be moved up and down alternately by swinging.

Further, the length of the link arm 81 from the arm rotation shaft 82 to the position of the center of gravity of the opening / closing auxiliary weight 84 is set so that a force for pulling up the gap opening / closing member 7 is easily applied by the opening / closing auxiliary weight 84 described later. It is formed longer than the length from 82 to the connecting position of the link rod 83. As shown in FIG. 5, in the link arm 81 of the present embodiment, the downstream side arm 81a is formed shorter than the upstream side arm 81b.

Further, as shown in FIGS. 5 and 6, the downstream side arm 81a is bent upward with respect to the upstream side arm 81b, and the connection position of the downstream side arm 81a with the link rod 83 rotates. It is configured to be located above the shaft 82. Further, the connection position of the downstream arm 81a with the link rod 83 is configured so that the door body 2 is arranged on the upstream side and slightly lower than the door body support shaft 4 in the initial angle state. ..

The arm rotation shaft 82 pivotally supports the link arm 81 and is provided at a position different from the door body support shaft 4 of the door body 2. In the present embodiment, as shown in FIG. 5, the arm rotation shaft 82 is described. It is arranged at a position upstream and below the door body support shaft 4.

The link rod 83 is a member for transmitting the swing of the link arm 81 to the gap opening / closing member 7, and is provided so as to connect the downstream arm 81a of the link arm 81 and the gap opening / closing member 7. The link rod 83 in the present embodiment is made of a columnar rod, and as shown in FIGS. 5 and 7, the upper end portion is rotatably connected to the tip end portion of the downstream arm 81a. As shown in FIGS. 5 and 8, the lower end portion is rotatably connected to the reinforcing plate 72 provided on the downstream side of the opening / closing member main body 71. Further, the connection position between the lower end of the link rod 83 and the gap opening / closing member 7 (reinforcing plate 72) is arranged on the downstream side and slightly higher than the axis of the hinge 73 when the door body 2 is at the initial angle. It is configured to be. Therefore, the length of the link rod 83 is formed to be shorter than the distance from the axis of the door body support shaft 4 to the axis of the hinge 73.

The opening / closing auxiliary weight 84 applies a load by weight to the upstream arm 81b when the door body 2 swings within the opening range of the initial angle or more, and opens / closes the gap via the downstream arm 81a and the link rod 83. The member 7 is for pulling up, and is provided on the upstream arm 81b. As shown in FIGS. 5 and 6, the opening / closing assisting weight 84 in the present embodiment is integrally formed by extending upward from the upstream arm 81b. Further, the opening / closing assisting weight 84 is upstream so that the length from the arm rotating shaft 82 to the position of the center of gravity of the opening / closing assisting weight 84 is longer than the length from the arm rotating shaft 82 to the connecting position of the link rod 83. It is formed closer to the rear end side of the side arm 81b.

The opening / closing assist weight 84 is not limited to the one integrally formed with the upstream arm 81b, and may be formed as a separate body and fixed to the upstream arm 81b.

The arm stopper 85 stops the rotation of the link arm 81 when the door body 2 swings within an opening range less than the initial angle. As shown in FIGS. 5 and 6, the arm stopper 85 in the present embodiment is formed in the upper part of the opening 200 of the water gate 100, and is in the lower part of the upstream arm 81b when the door body 2 is at the initial angle. Upon contact, the upstream arm 81b is supported so as not to swing further downward, and the rotation is stopped.

The door stop 9 is for ensuring a watertight state of the opening 200 by being in close contact with the upstream side surface of the door body 2 and the gap opening / closing member 7, and is installed in the opening 200. As shown in FIG. 1, the door stop 9 in the present embodiment is formed along the upper door stop 91 formed horizontally along the upper edge portion of the opening 200 and along the left and right edges of the opening 200. 92 left and right side doors, 93 lower doors that are formed along the bottom surface 300 of the floodgate 100 and extend downstream from the left and right side doors 92, and left and right side doors. It has an opening / closing member receiving portion 94 provided in an inclined shape at the lower end corner of the 92.

The upper door contact 91 is in contact with the upper edge portion of the upstream side surface of the door body 2, and the downstream surface side is formed flat along the vertical surface in order to ensure watertightness.

The side door stop 92 abuts on the side portion of the upstream side surface of the door body 2, and extends downward from the left and right ends of the upper door stop 91. Similar to the upper door stop 91, the side door stop 92 is formed flat on the downstream surface side along the vertical surface in order to ensure watertightness.

The lower door stop 93 abuts on the lower end of the gap opening / closing member 7, and extends horizontally from the lower end of the side door stop 92 toward the downstream side. The upper surface of the lower door stop 93 in the present embodiment is formed flat along the horizontal plane in order to ensure watertightness with the lower end of the gap opening / closing member 7.

The opening / closing member receiving portion 94 is a portion that abuts on the upstream side surfaces of the left and right ends of the gap opening / closing member 7, and is provided in an inclined shape at the lower end corner of the left and right side door contacts 92 as shown in FIGS. 1 and 2. Has been done. The opening / closing member receiving portion 94 in the present embodiment has a downwardly inclined shape from the side door contact 92 toward the downstream side, and the upper surface thereof is formed in a flat shape. The inclination angle of the opening / closing member receiving portion 94 is not particularly limited and may be appropriately selected.

Next, the operation of each configuration in the flap gate 1 of the present embodiment will be described based on the distance between the configurations shown in FIG. 9 and the like.

As shown in FIG. 9, the distance A is a horizontal distance from the axis of the door body support shaft 4 to the connection position between the link arm 81 and the link rod 83. The distance B is the distance from the axis of the door body support shaft 4 to the connection position between the link arm 81 and the link rod 83. The distance C is the radius of the downstream arm 81a (the distance from the axis of the arm rotation shaft 82 to the connection position between the link arm 81 and the link rod 83). The distance D is the distance from the axis of the door body support shaft 4 to the connection position between the gap opening / closing member 7 and the link rod 83. The distance E is the length of the link rod 83 (distance between the upper and lower connecting points of the link rod 83). The distance F is the distance from the axis of the door body support shaft 4 to the axis of the hinge 73.

At each of these distances, the distance C (radius of the downstream arm 81a), the distance E (the length of the link rod 83), and the distance F (the distance from the axis of the door body support shaft 4 to the axis of the hinge 73) are constant values. Is. Further, the angle of the gap opening / closing member 7 with respect to the door body 2 at the initial angle is set to α ₁ .

First, as shown in FIG. 10, a state in which the angle (opening) of the door body 2 is 90 degrees will be described. The water level on the upstream side and the downstream side rises, and the door body 2 is opened up to 90 degrees due to the buoyancy of the float 22 on the back surface.

The link arm 81 is not stopped by the arm stopper 85, and is in a state of being freely rotatable with the arm rotation shaft 82 as a fulcrum. Therefore, the opening / closing assist weight 84 applies a pushing force to the upstream arm 81b of the link arm 81 due to its weight. On the other hand, the downstream arm 81a rises as the upstream arm 81b descends. The link rod 83 pulls up the gap opening / closing member 7 in response to the force of the downstream arm 81a to rise.

At this time, since the downstream side arm 81a is configured to be located above the arm rotation shaft 82, it acts to pull the link rod 83 upward or upstream. Further, since the length from the arm rotation shaft 82 to the position of the center of gravity of the opening / closing assist weight 84 is formed longer than the length from the arm rotation shaft 82 to the connection position of the link rod 83, the opening / closing assist weight 84 is formed. The link rod 83 can be pulled with a strong force against the weight.

The gap opening / closing member 7 is in a state of being pulled up by the link rod 83, and is held at the _{same angle α 1 as at the initial angle with respect to the door body 2.} At this time, the distance D in the present embodiment is maintained at the same distance as the distance D at the initial angle.

Next, as shown in FIG. 11, a state in which the angle of the door body 2 is in the range from the initial angle or more to less than 90 degrees will be described. The movement of the link arm 81 is not stopped by the arm stopper 85 as in the case of 90 degrees, and the link arm 81 is in a state of being freely rotatable with the arm rotation shaft 82 as a fulcrum. Therefore, the gap opening / closing member 7 is pulled up by the action of gravity of the opening / closing auxiliary weight 84. The distance A (horizontal distance between fulcrums) is longer than when it is 90 degrees, and the distance B (distance between fulcrums) is also longer than when it is 90 degrees.

On the other hand, as for the distance D, the same distance as the distance D at the initial angle is maintained as in the case of 90 degrees, and the gap opening / closing member 7 has the same angle α as the initial angle with respect to the door body 2. It is held at _1.

As described above, when the angle of the door body 2 is equal to or larger than the initial angle, the distance A and the distance B change, but the distance D is constant by pulling up the gap opening / closing member 7 by the action of the gravity of the opening / closing auxiliary weight 84. The gap opening / closing member 7 can be held at the _{same angle α 1} as the initial angle with respect to the door body 2.

Therefore, as shown in FIGS. 9 to 11, the gap opening / closing member 7 is sufficient for draining water from the upstream side between the gap opening / closing member 7 and the bottom surface 300 of the floodgate 100 without providing a step. A gap can be secured. In addition, dust such as driftwood that flows along with the drainage also flows downstream, so that it becomes difficult for dust to accumulate in the vicinity of the floodgate 100.

Next, a state in which the angle of the door body 2 is less than the initial angle and larger than 0 degrees will be described. As shown in FIG. 12, the arm stopper 85 stops the rotation of the link arm 81 when the door body 2 is in the initial angle state. Specifically, the arm stopper 85 supports the lower part of the upstream arm 81b and stops the movement of the upstream arm 81b to descend and rotate. Further, the movement of the upstream arm 81b to rotate upward is stopped by the weight of the opening / closing auxiliary weight 84. Therefore, the link arm 81 is held in a state where the rotation is stopped. As a result, the connection point between the link rod 83 and the link arm 81 is fixed, and the distance A and the distance B are maintained at the same length as at the initial angle.

On the other hand, the link rod 83 tends to rotate in the same direction as the door body 2 rotates in the closing direction. Since the rotation of the link arm 81 is stopped, the link rod 83 rotates about the connection point with the link arm 81 on the upper end side.

Since the door body support shaft 4 and the arm rotation shaft 82 are provided at different positions, the distance D changes. Specifically, the distance D extends with respect to the case where the door body 2 has an initial angle of 11 degrees. On the other hand, the distance F between the door body support shaft 4 and the hinge 73 is constant. _{Therefore, the gap opening / closing member 7 has a larger angle α 2} with the door body 2 according to the amount of change in the distance D (α ₁ <α ₂ ). That is, the opening / closing operation assist mechanism 8 can tilt the gap opening / closing member 7 in the direction of closing the gap C with the bottom surface 300 of the floodgate 100 as the angle of the door body 2 becomes smaller.

Then, as shown in FIG. 13, when the angle of the door body 2 becomes 0 degrees to close the opening 200 of the floodgate 100, the opening / closing operation assist mechanism 8 hits the door stop 9 in which the gap opening / closing member 7 is provided in the opening 200. Get in touch. The opening / closing operation assist mechanism 8 in the present embodiment can tilt the gap opening / closing member 7 to the same angle (α ₃ ) as the inclination angle of the opening / closing member receiving portion 94 so that the opening / closing member receiving portion 94 can be brought into contact with the opening / closing member receiving portion 94. As a result, the gap opening / closing member 7 can close the gap C between the lower end edge 21 of the door body 2 and the bottom surface 300 of the water gate 100, and can close the opening 200 of the water gate 100 together with the door body 2.

On the other hand, when the angle of the door body 2 is within the opening range from 0 degree to less than the initial angle, the opening / closing operation assist mechanism 8 gradually pulls up the gap opening / closing member 7 as the angle increases. Then, when the door body 2 is tilted to the initial angle, the door body 2 is pulled up to a predetermined angle with respect to the door body 2, and a gap can be formed again between the door body 2 and the bottom surface 300 of the water gate 100.

According to the flap gate 1 of the present embodiment as described above, the following effects can be obtained.
1. 1. When the door body 2 is opened at an initial angle or more, the opening / closing operation assist mechanism 8 pulls up the gap opening / closing member 7 in the opening direction, so that the gap between the door body 2 and the bottom of the 300 is large even if the water gate 100 is not provided with a step. Can be taken.
2. 2. When the door body 2 swings within the opening range less than the initial angle, the opening / closing operation assist mechanism 8 swings the gap opening / closing member 7 in conjunction with the door body 2, and the door body 2 swings at the opening of the water gate 100. When the 200 is closed, the gap opening / closing member 7 is brought into contact with the door stop 9 to close the gap C, and watertightness with the opening 200 can be ensured.
3. 3. Since the length from the arm rotation shaft 82 to the position of the center of gravity of the opening / closing auxiliary weight 84 is formed longer than the length from the arm rotation shaft 82 to the connection position of the link rod 83, the gap opening / closing member by the opening / closing auxiliary weight 84 is formed. The pulling effect of 7 can be enhanced, and the configuration of the link arm 81 and the like can be made compact accordingly.
4. Since the connection position of the downstream arm 81a with the link rod 83 is configured to be located above the arm rotation shaft 82, the effect of pulling up the gap opening / closing member 7 by the opening / closing auxiliary weight 84 can be enhanced. When the door body 2 is swinging within the opening range less than the initial angle, the gap opening / closing member 7 can be interlocked to facilitate swinging.
5. By providing the opening / closing member receiving portion 94 at the lower end corner of the side door contact 92, the angle required for contact with the gap opening / closing member 7 becomes shallow, and the opening / closing operation assist mechanism 8 does not significantly change the angle. Can also close the gap C.

The flap gate according to the present invention is not limited to the above-described embodiment, and can be appropriately changed. For example, the opening / closing operation assisting mechanism 8 may be able to open / close the gap opening / closing member 7 in conjunction with the angle of the door body 2 by means of a gear or the like without using the link mechanism.

1 Flap gate 2 Door body 3 Door body support arm 4 Door body support shaft 5 Weight arm 6 Balance weight 7 Gap opening / closing member 8 Opening / closing operation assist mechanism 9 Door stop 21 Lower end edge 22 Float 71 Opening / closing member body 72, 72b Reinforcing plate 73 Hinge 74 bulge 75 Fixing block 76a, 76b Plate material 77 Slit 81 Link arm 81a Downstream arm 81b Upstream arm 82 Arm rotation shaft 83 Link rod 84 Opening and closing auxiliary weight 85 Arm stopper 91 Upper door stop 92 Side door stop 93 Lower door per 94 Opening / closing member receiving part 100 Water gate 200 Opening 300 Bottom surface 400 Bearing C Gap

Claims (5)

A flap gate that opens and closes the opening of a floodgate, equipped with a flap-type door body that is suspended at a predetermined initial angle in a balanced manner when no external force other than gravity is applied.
The door body is installed so as to form a gap at a predetermined interval between the lower end edge of the door body and the bottom surface of the water gate in a state where the water gate is closed, and the door body is installed. The lower end edge portion is provided with a gap opening / closing member that swings around the lower end edge portion as a fulcrum to open / close the gap.
When the door body is opened at the initial angle or more, the gap opening / closing member is pulled up in the opening direction, and when the door body is swinging within the opening range less than the initial angle, the gap opening / closing member is pulled. The opening / closing operation assisting mechanism is provided, which swings in conjunction with the door body and brings the gap opening / closing member into contact with the door contact of the opening when the door body closes the opening of the water gate. Flap gate. The opening / closing operation assist mechanism is
A link arm in which the downstream arm and the upstream arm are alternately supported so as to be vertically movable with an arm rotation shaft provided at a position different from the door body support shaft of the door body as a fulcrum.
A link rod connecting the downstream arm of the link arm and the gap opening / closing member,
An opening / closing auxiliary weight provided on the upstream arm of the link arm, and
An arm stopper that stops the rotation of the link arm when the door body swings within an opening range less than the initial angle, and
The flap gate according to claim 1. 2. The link arm is formed so that the length from the arm rotation shaft to the position of the center of gravity of the opening / closing auxiliary weight is longer than the length from the arm rotation shaft to the connection position of the link rod. The flap gate described in. The flap gate according to claim 2 or 3, wherein the connection position of the downstream arm with the link rod is configured to be located above the arm rotation axis. Left and right side parts of the door stop At the lower end corners of the door stop, an opening / closing member receiving portion that comes into contact with the gap opening / closing member when the door body closes the opening is provided. The flap gate according to any one of claims 1 to 4.

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