JP2017043931A - Rotary backflow prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary backflow prevention device using a waterproof plate that may be laid on a water bottom at a time of forward flow, and may keep a stably erected state at a time of backflow.SOLUTION: A rotary backflow prevention device A rises from a laid state on a water bottom. The rotary backflow prevention device A includes: a waterproof plate 1 generating buoyancy in a flowing body; a first link 2 connecting rotatably a bottom edge side of the waterproof plate 1 that has risen with a downstream side pedestal 4; and a second link 3 connecting rotatably a top edge side of the waterproof plate 1 that has risen with an upstream side pedestal 5, the second link 3 being longer than the first link 2. A convex curved surface 11a that faces downward is provided on an undersurface of the waterproof plate 1 in the laid state, and an open space 11b is formed between the convex curved surface 11a and the water bottom surface. The rotary backflow prevention device is brought to the laid state on the water bottom, when inverse lift is exerted on the waterproof plate 1 by a water flow that enters the space 11b and a water flow flowing on a top surface side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotary backflow prevention device in waterways, rivers, etc., and in a normal forward flow, presents a state of lying down on the bottom of the water using a reverse lift, and functions to prevent backflow by standing up at the backflow accompanying the occurrence of a tsunami or storm surge The present invention relates to a rotary backflow prevention device capable of exhibiting

  Conventionally, the river facility has been provided with a backflow prevention gate for preventing a backflow in preparation for river increase due to a tsunami or storm surge. A conventional backflow prevention gate has a structure in which a water channel is opened and closed by a door body that slides in the vertical direction, and the backflow is prevented by raising and lowering the door body in accordance with an increase or decrease in the amount of water.

  When a river is flooded due to a tsunami or storm surge, the river manager must open and close the gate according to the degree of flooding each time, and after returning to the normal state, the gate must be returned to the normal state. I must. For this reason, the burden on the manager is great and the risk of encountering an accident is high.

  Therefore, the waterway gate device described in Patent Document 1 is pivotally supported in a waterway in which water flows in a certain direction, and has a door body that generates a levitation force in water. When the river side increases in water, the door body stands up. The lower part of the door body is pivotally supported by a lower door at the bottom of the waterway via a hinge, and an elastic sealing material that can be bent along with the tilting of the door body is provided on the shaft support part. Attached to the upper edge of the door body is an elastic sealing material that can be attached to and detached from the upper door of the ceiling of the waterway, and slides on both sides of the door body against the side door of the inner surface of the waterway. Possible elastic sealing material is attached.

Such a device has a mechanism in which one end is fixed to the bottom of the water with a hinge, and at the time of backflow, it automatically rotates and stands up by the force of the flow to prevent backflow. However, neutral buoyancy (neutral plus or minus buoyancy that does not lift or sink in water) or some buoyancy is required in order to ensure that the waterproof plate stands upright during reverse flow. The plate cannot be stably placed on the bottom of the water during forward flow.

JP 2001-172947 A

  An object of the present invention is to provide a rotary backflow prevention device using a waterproof plate that can be stably placed on the water bottom during forward flow and can maintain a stable standing state during backflow.

The rotary backflow prevention device of the present invention is a rotary backflow prevention device that stands up from a state where it lies on the bottom of the water, and the rotary backflow prevention device includes a waterproof plate that generates a levitation force in a fluid, and the waterproof plate A first link that pivotably connects the lower end side and the downstream pedestal in the upright state, and an upper end side and upstream side pedestal in the upright state of the waterproof plate that are pivotally connected, respectively. It comprises a second link that is longer than the first link, and is provided with a convex curved surface portion directed downward on the lower surface of the waterproof plate in a lying state, between the convex curved surface portion and the water bottom surface. A space that has been released to the bottom of the water by causing a reverse lift to the waterproof plate by both the water flow entering the space and the water flow entering the upper surface. It is what.

  According to such a rotary backflow prevention device, in a state where the waterproof plate in the forward flow has fallen to the bottom of the water, a reverse curved force is generated by providing a convex curved surface portion on the lower surface of the waterproof plate, and the waterproof plate generates a levitation force in water. Even so, it is possible to maintain a stable and stable waterproofing state of the waterproof board. In addition, during the transition from the forward flow to the reverse flow, the water flow of the forward flow and the reverse flow is balanced, and the waterproof plate is lifted by the levitation force generated in the waterproof plate released from the reverse lift force. By acting, the backflow can be prevented by the waterproof plate standing.

In addition, if the convex curved portion is formed so as to generate a reverse lift only for the forward water from the upstream side, if the transition time is extremely short, the water pressure due to the reverse flow acts before the waterproof plate rises. However, since the reverse lifting force that prevents the waterproof board from floating does not act, the waterproof board can be erected more reliably.

  Furthermore, if the convex curved surface portion is a wing shape, it can be expected that reverse lift force is generated more effectively.

  According to the rotational backflow prevention device of the present invention, the bottom surface of the waterproof plate is formed as a wing-shaped convex curved surface, so that when the forward flow, the waterproof plate has a vertically downward reverse lift so that the plate is substantially parallel to the bottom of the water. Acts, and a stable lying state is maintained. In addition, when the reverse flow, the waterproof plate is easily inclined due to the resistance of the flow (Fig. 4 (b)), and no reverse lift that prevents buoyancy occurs, the upper surface side of the waterproof plate rotates downstream while floating more reliably, When the water pressure of the backflow water acts on the upper surface of the waterproof plate, the rotation is promoted and finally the standing state can be achieved. Furthermore, if the convex curved surface portion is a wing shape, it becomes possible to generate a reverse lift force with the waterproof plate vertically downward more effectively against forward water.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a side view of a rotary backflow prevention device according to an embodiment of the present invention in a lying state, and FIG. It is (a) AA top view, (b) BB top view, (c) CC sectional drawing of the rotary backflow prevention apparatus which concerns on embodiment of this invention. It is the schematic which shows the action force of the rotary backflow prevention apparatus which concerns on embodiment of this invention. (A) A side view showing a lying state during forward flow, (b) a side view showing a waterproof plate floating state during transition, and (c) an upright state during reverse flow of the rotary backflow prevention device according to the embodiment of the present invention. FIG.

The structure of the rotary waterproof device of the present invention is shown in FIGS.
The rotary waterproof device A according to the present invention includes a first link 2 that pivotably connects the waterproof plate 1 and the lower end side and the downstream pedestal 4 when the waterproof plate 1 stands upright, and the waterproof plate 1 stands up. The second link 3 is longer than the first link 2 in which the upper end side and the upstream side pedestal 5 are rotatably connected to each other. And has a space 11b that is open between the convex curved surface portion 11a and the water bottom surface, and is waterproofed by both the water flow entering the space 11b and the water flow entering the upper surface side. By causing the plate 1 to generate a reverse lift force, the plate 1 is in a state of falling on the bottom of the water.
Hereinafter, details of each member and other configurations will be described.

  As shown in FIG. 1, when constructing a waterproof device, it is desirable to first provide a foundation a on the bottom of the water in the direction of the backflow water caused by the increase of rivers such as tsunami and storm surge. On the foundation a, two pedestals (downstream pedestal 4 and upstream pedestal 5) are arranged with an interval in the direction of the backflow of water.

<Waterproof board 1>
As shown in FIG.1 (b), the waterproof board 1 is a member for resisting backflow water in the state which stood up in water.
The waterproof board 1 may be appropriately designed in material and size from various conditions such as a water level expected at the time of occurrence of water increase and desired strength, weight, and volume.
In addition, since the waterproof board 1 is normally placed on the water bottom in a lying state, even if it is long in the height direction, it does not hinder the operation of the ship or the like.

  As shown in FIG. 2A, the waterproof plate 1 includes a top plate 11 and side plates 12 and 12, and the side plates 12 and 12 are integrally formed so as to sandwich the top plate 11. In the embodiment, the top surface of the top plate 11 and the top surfaces of the side plates 12 and 12 have the same flat surface.

As shown in FIGS. 2B and 2C, a convex curved surface portion 11 a facing downward is provided on the lower surface of the top plate 11, and between the convex curved surface portion 11 a and the water bottom surface or the upper surface of the foundation a. A released space 11b is provided. The space 11b is formed so that the water flow from the upstream side and the downstream side shown in FIG.
The convex curved surface portion 11a has a wing shape and is configured such that a reverse lift acts on a forward water flow from the upstream side.
The shape of the convex curved surface portion 11a may be circular, elliptical, or other shapes as long as the reverse lift acts, and is not limited to the wing shape.

As shown in FIGS. 2 (a) and 2 (b), the waterproof plate 1 is provided with connecting portions 13a, 13a and 13b, 13b for rotatably connecting a first link 2 and a second link 3 described later. Are integrally fixed to the upper end side and the lower end side in the state where the waterproof plate 1 stands.

<Link mechanism>
The link mechanism is a member for controlling movement / rotation of the waterproof board 1.
As shown in FIGS. 1A and 1B and FIGS. 2A and 2B, the link mechanism includes a first link 2 and a second link 3 having different lengths.
The first links 2 and 2 are short link members, one end of which is pivotally connected to the connecting portions 42 and 42 of the downstream pedestal 4 and the other end is a lower end in a state where the waterproof plate 1 is raised. It is connected to the connecting parts 13b, 13b on the side so as to be rotatable.
The second links 3, 3 are long link members, one end of which is rotatably connected to the connecting portions 52, 52 of the upstream pedestal 5, and the other end is in a state where the waterproof plate 1 is erected. The upper end side connecting portions 13a and 13a are rotatably connected.
What is necessary is just to design a material and a size suitably for link members from various conditions, such as desired intensity | strength, weight, a dimension.

<Pedestal>
As shown in FIGS. 1A and 1B and FIGS. 2A and 2B, the fixing portions 41 and 41 of the downstream pedestals 4 and 4 and the fixing portions 51 and 51 of the upstream pedestals 5 and 5 are There is a method of joining directly to the foundation a and fixing them, or fixing them to the bottom of the water, but in any case, after fixing members such as anchors and piles on the bottom of the water, each base is directly fixed to the fixing members. There is a method of fixing through the foundation a. Since a large external force through the link member acts on each pedestal, it is necessary to have a structure that can resist the desired external force.

<Action>
As shown in FIG. 3A, in the vertical direction of the waterproof board 1, the weight G and the reverse lift L of the waterproof board 1 act vertically downward, and the buoyancy F0 acts vertically upward. The reverse lift L is caused by the forward flow velocity V0 acting on the waterproof plate 1 from the upstream side, so that the forward water flow is diverted to the convex curved surface portions 11b on the upper surface and the lower surface of the waterproof plate 1, thereby It happens to hold down.

As shown in FIG. 3B, in the vertical direction of the waterproof board 1, the weight G of the waterproof board 1 acts vertically downward and the buoyancy F1 acts vertically upward. Since there is no forward water flow passing through the upper and lower surfaces of the waterproof 1, the reverse lift L does not occur. Since buoyancy occurs per submerged volume, no buoyancy occurs in the range above the water surface. Therefore, when the waterproof board 1 protrudes from the water surface when buoyancy occurs, the buoyancy F1 is small compared to the buoyancy F0 in the lying state.

FIG. 4 shows the transition of the waterproof board 1 from the lying down state to the standing state. FIG. 6A shows the waterproofing board 1 lying down as described above, and the waterproofing board 1 is subjected to its own weight G, buoyancy F0 and reverse lifting force L.

FIG. 4B shows a transition state in which the water flow stops due to the balance between the forward water from the upstream side and the backflow water from the downstream side due to the influence of the increase in the downstream water. Since the forward water from the upstream side is in a stopped state, no reverse lift L is generated in the waterproof plate 1, and only the own weight G and buoyancy F0 are generated. Since the buoyancy F0 is adjusted so as to require neutral buoyancy or slight buoyancy, the waterproof plate 1 is lifted by the buoyancy F0 in a state where the water flow is stopped or in a state where a slight amount of backflow water resistance is generated. The posture of the waterproof board 1 due to lifting is limited by the first link and the second link. Specifically, since the second link 3 on the upstream side is longer than the first link 2 on the downstream side, the upper surface of the waterproof board 1 rotates downstream.

As the projected area from the downstream side of the upper surface of the waterproof board 1 gradually increases due to the rotation accompanying the buoyancy, the acting force of the backflow water from the downstream side pushing the waterproof board 1 upstream increases. Eventually, as shown in FIG. 4C, the rotation and buoyancy of the waterproof plate 1 are limited to the first link 2 and the second link 3, and the waterproof plate 1 reaches a completely upright state. Subsequent backflow water is suppressed by the waterproof board 1.

In the conventional flap-type backflow waterproof device, the posture cannot be stably maintained when the backflow becomes weak, but in the present invention, the backflow changes to the forward flow, and the upstream water level becomes stable until it becomes higher than the downstream water level. Can maintain a standing posture.

A Rotational backflow prevention device 1 Waterproof plate 2 First link 3 Second link 4 Downstream pedestal 5 Upstream pedestal 11a Convex curved surface portion 11b Space

Claims (3)

A rotary backflow prevention device that stands up from a state lying on the bottom of the water,
The rotary backflow prevention device is
A waterproof plate that produces buoyancy in the fluid;
A first link that pivotably connects a lower end side and a downstream side pedestal in a standing state of the waterproof plate,
The upper end side and the upstream side pedestal in a standing state of the waterproof plate are rotatably connected to each other, and the second link is longer than the first link.
On the lower surface of the waterproof board in a lying state, a convex curved surface portion directed downward is provided,
Having a released space between the convex curved surface portion and the water bottom;
By causing a reverse lifting force to the waterproof plate by both the water flow entering the space and the water flow entering the upper surface side, it will be in a state lying on the bottom of the water.
Rotating backflow prevention device characterized by that. 2. The rotary backflow prevention device according to claim 1, wherein the convex curved surface portion is configured to generate a reverse lifting force with respect to a water flow from an upstream side.   The rotary backflow prevention device according to claim 1, wherein the convex curved surface portion has a wing shape.

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