JPH10252044A - Back flow preventing gate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of the defective closing action of a door body caused by suspended matters such as drifting logs by providing a stopper tiltably fitted in a passage and blocking the flow-down of the suspended matters floated on a fluid in the passage on the upstream side of the door body having flotation in the fluid. SOLUTION: A stopper 35 blocking the flow-down of suspended matters such as drifting logs 30 floatingly moved on water 40 is liftably provided on a ceiling 34 in a conduit 32 upstream from a door body 33 in the suspended state. When the downstream water surface 41 is lowered and made lower than the upstream water surface 43 after the conduit 32 is temporarily closed, the buoyancy applied to the door body 33 by the water 42 in the downstream is decreased, the door body 33 is automatically prostrated to downstream, and the water 40 in the upstream again flows downstream over the overflow section 33a of the door body 33. The flow-down of the drifting logs 30 floatingly moved on the water 40 is blocked by the stopper 35, and the closing action of the door body 33 is not hindered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backflow prevention gate installed at a gutter or a gutter pipe as a river management facility, and more particularly to a backflow prevention gate having a function of preventing a floating substance from being caught.

[0002]

2. Description of the Related Art Conventionally, as a river management facility, a backflow prevention gate has been installed at a gutter or a gutter pipe in order to prevent a backflow when a river is flooded due to a torrential rain.
The conventional backflow prevention gate has a structure in which a water passage is opened and closed by a door body that slides in a vertical direction, and the backflow is prevented by moving the door body up and down according to an increase or decrease in the amount of water.

[0003] When a river is flooded due to a typhoon or torrential rain, the manager goes to the site where the backflow prevention gate is installed, day or night, and adjusts the height of the door according to the flooding condition. This prevents backflow from the river side. Further, when a typhoon or the like has passed and the water volume of the river has returned to normal, the manager again goes to the installation site of the backflow prevention gate and adjusts the height of the door body.

[0004] As described above, in the conventional backflow prevention gate, when the amount of water increases or decreases due to the weather or the like, it is necessary for the manager to go to the site and adjust the height of the door each time. A lot of effort is spent on management.

In many cases, it is necessary to prevent a backflow from a river during a typhoon or a torrential downpour, and the manager goes to the site in the severe wind and rain and operates the floodgate. Therefore, the burden is large and the danger is high.

Further, in the case of a typhoon or a torrential downpour, if the timing of opening and closing the floodgate is incorrect, a disaster such as a flood may be caused. In case of heavy rain,
The reality is that it is difficult to respond quickly.

In order to cope with such a situation, the present applicant has developed a backflow prevention gate having a function of automatically operating when a river rises to prevent backflow, and is disclosed in Japanese Patent Application No. 8-310945. Has filed a patent application.

The backflow prevention gate according to Japanese Patent Application No. 8-310945 has a structure as shown in FIG.
Door body 12 that is pivotally supported inside and generates a buoyancy force in water
As a closing means for closing the water channel 11 when the door body 12 stands up, a sealing member 1 is provided on an outer peripheral portion of the door body 12.
7 are provided, and door stop members 19 and 20 are provided on the side wall 15 and the ceiling 18 of the water channel 11 to abut against the sealing member 17 of the door body 12 to prevent the passage of water.

The force caused by the flow of the water 21 and the buoyancy caused by the water 24 on the downstream side simultaneously act on the door body 12 pivotally supported in the water channel 11 in which the water 21 flows in a certain direction. As shown in FIG. 4A, the door body 12 stands up slightly inclining from the vertical to the downstream side. Therefore, the upstream water surface 22 of the water 21 blocked by the door body 12
Is higher than the downstream water surface 23, and the upstream water 21 flows over the overflow section 12 a of the door body 12 and flows downstream.

On the other hand, when the downstream water surface 23 rises, the buoyancy of the downstream water 24 acting on the door body 12 increases, so that the door body 12 automatically rises upstream.
Finally, as shown in FIG.
The sealing member 17 located in the upper part of 2 contacts the door stop member 20, and the waterway 11 is closed. As a result, water 24
Backflow from the downstream side to the upstream side can be prevented.

On the other hand, after the water channel 11 is closed, when the downstream water surface 23 descends and becomes lower than the upstream water surface 22,
The buoyancy due to the water 24 on the downstream side acting on the door body 12 is reduced, and the door body 12 automatically falls down to the downstream side, as shown in FIG.
Since the state shown in (b) is reached, the water 21 fluid on the upstream side
It again flows over the upper part of the door body 12 and flows downstream.

As described above, since the backflow prevention gate 10 of the present embodiment is tilted in accordance with an increase or decrease in the amount of water, when the downstream water surface 23 rises, the water passage 11 is automatically closed to prevent backflow. And has an excellent function of preventing water leakage even at the time of closing.

On the other hand, as one of the devices for damming a river and maintaining the water level on the upstream side at a predetermined level, a device called a fall gate has been conventionally used, for example, Japanese Utility Model Laid-Open No. 6-56131. And the like disclose the technology.

[0014]

Problems to be Solved by the Invention Japanese Patent Application No. 8-31094
In the case of the backflow prevention gate 10 according to No. 5, as shown in FIG. 5, when the floating body such as the driftwood 30 is flowing on the upstream water surface 22 and the door body 12 rises due to the rise of the downstream water surface 23. The driftwood 30 may bite between the upper part of the door body 12 and the door stop member 20, and the door body 12 may not stand up to the predetermined position. Door 1 by driftwood 30
When the erecting of the canal 2 is hindered, as shown in FIG.
Cannot be completely closed, and a gap 11a is formed in the upper part of the door body 12, so that the backflow cannot be prevented. In such a case, the waterway 11 cannot be completely closed unless the human removes the driftwood 30 or the driftwood 30 falls to the downstream side.

As described above, when floating substances such as driftwood 30 flow into the upstream water surface 22, the closing operation of the door body 12 is often hindered in an emergency such as an increase in water level, which causes a backflow. .

On the other hand, a gate spoiler disclosed in Japanese Utility Model Laid-Open Publication No. 6-56131 discloses a gate for maintaining a water level on an upstream side at a predetermined level, for flowing down driftwood or the like caught on the gate. Therefore, the adverse effects of driftwood at the backflow prevention gate cannot be prevented.

An object of the present invention is to provide a backflow prevention gate having a tiltable door body.
An object of the present invention is to prevent a door closing operation defect from occurring due to floating substances such as driftwood.

[0018]

In order to solve the above problems, the present invention comprises a door body which is tiltably mounted in a flow path in which a fluid flows in a certain direction and generates a levitation force in the fluid,
A backflow prevention gate for closing a flow path by raising a door body due to an increase in fluid on the downstream side, and a stopper for preventing a floating substance floating in the fluid from flowing down in a flow path upstream of the door body. Is provided.

When a door that generates a buoyancy in the fluid is tiltably mounted in a flow path in which the fluid flows in a certain direction, a force due to the flow of the fluid and a buoyancy due to the fluid act on the door. Then, the door body is in an upright state inclined slightly downstream from the vertical, and the fluid on the upstream side flows over the overflow section of the door body and flows to the downstream side.

Here, when the liquid level on the downstream side rises, the buoyancy of the fluid on the downstream side acting on the door body increases, so that the door body automatically rises to the upstream side. Specifically, the channel is closed by the door body and the closing means that are upright. This can prevent the fluid from flowing backward from the downstream side to the upstream side.

On the other hand, after the flow path is closed, when the liquid level on the downstream side falls and becomes lower than the liquid level on the upstream side, the buoyancy due to the downstream fluid acting on the door decreases. Since the door body automatically falls to the downstream side, the fluid on the upstream side flows over the overflow portion of the door body again and flows to the downstream side.

In the backflow prevention gate according to the present invention, a stopper is provided in the flow path on the upstream side of the door body, and the stopper stops the floating material that has floated and moved in the fluid and stops at that position. The object does not hinder the closing operation of the door.

In this case, the stopper is provided so as to hang down from the ceiling portion in the flow passage so that the surface of the fluid on the upstream side of the door body approaches the ceiling portion in the flow passage. In addition, a function of preventing the flow of suspended matters can be provided.

Therefore, when the fluid on the downstream side has a low surface and the fluid is flowing in a state where the door body is greatly inclined to the downstream side, the suspended matter flows downstream with the fluid without being caught by the stopper. When the surface of the fluid on the downstream side rises and the door body rises, and the surface of the fluid on the upstream side also rises, the stopper prevents flow of suspended matter. That is,
Floating matter does not accumulate in the stopper during normal flow, and when the closing operation of the door body becomes necessary due to increased water or the like, it is possible to prevent the floating matter from being caught.

In order to generate a buoyant force on the door body in the fluid, for example, a structure for generating a buoyant force by the same principle as a so-called floating ring by forming an airtight space inside the door body, or A structure that generates a buoyancy by forming the door itself with a material having a specific gravity smaller than that of the fluid can be employed.

As means for closing the flow path with the door,
A structure in which a sealing member is provided on the outer peripheral portion of the door body, and a door stop member that contacts the sealing member is provided in the flow path. With this, when the fluid surface on the downstream side rises and the door body stands, the sealing member on the outer periphery of the door body is in close contact with the door stop member in the flow path without any gap, so that the flow path is completely closed. can do. Therefore, backflow does not occur even when the downstream fluid surface becomes high.

On the other hand, by forming an opening for the passage of the fluid in the stopper, the fluid can be passed smoothly without lowering the function of preventing the suspended matter from flowing down. The flow of suspended matter can be prevented without lowering the flow rate. in this case,
As the opening, one having a slit, a hole, or the like, or one having the stopper itself formed of a mesh can be used.

Furthermore, if an elevating mechanism for changing the installation height of the stopper is provided, the installation height of the stopper can be freely adjusted, so that even if the size of the suspended matter changes, the flow can be effectively reduced. Can be blocked. In addition, if the lower portion of the stopper is installed in a state where it is inserted deeply into the fluid, it is possible to prevent not only the suspended matter on the fluid surface but also the suspended matter floating in the fluid from flowing down.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a backflow prevention gate according to an embodiment, and FIGS. 2 and 3 are explanatory views showing a function of a stopper of the backflow prevention gate.

The backflow prevention gate 31 of the present embodiment includes a door 33 which is pivotally supported in a water passage 32 in which water flows in a certain direction and generates a buoyancy force in the water, and a water passage 32 when the door 33 stands up. Closing means for closing the door 33.
On the ceiling 34 in the water passage 32 on the more upstream side, a stopper 35 is provided in a hanging manner to prevent the floating material such as the driftwood 30 floating in the water from flowing down. Here, since the stopper 35 can be moved up and down, the installation height can be adjusted.

When the door 33 is upright, the water channel 32
As a means for closing the door, a sealing member 3
6 are provided, and door stop members 38 and 39 are provided on the side wall 37 and the ceiling 34 of the water channel 32 to abut against the sealing member 36 of the door body 33 to prevent the passage of water.

The door body 12 is formed of a stainless steel plate, and has a structure in which an airtight space is provided in order to generate a buoyant force on the door body 33 in water. That is, since the door body 12 has a box structure in which air is sealed inside, the door body 12 generates buoyancy in water by the same principle as a so-called floating ring.

When the door 33 is pivotally supported in the water channel 32, the force of the water flow and the buoyancy of the water act on the door 33, so that the door 33 is moved slightly downstream from the vertical. Since the upstream water surface 43 rises in an inclined and upright state, the water 40 flows over the overflow section 33 a of the door body 33 and flows downstream.

When the downstream water surface 41 rises, the buoyancy of the downstream water 42 acting on the door 33 increases, so that the door 33 automatically rises upstream. Finally, the waterway 32 is closed by the upright door body 33 and the closing means described above. This can prevent the water 42 on the downstream side from flowing backward to the upstream side.

On the other hand, after the water channel 32 is closed, the downstream water surface 41 descends and becomes lower than the upstream water surface 43.
The buoyancy of the downstream water 42 acting on the door body 33 is reduced, and the door body 33 automatically falls to the downstream side. 33a, and flows downstream.

As shown in FIG. 1, in the backflow prevention gate 31 of the present embodiment, a stopper 35 is provided on a ceiling 34 in a water channel 32 upstream of a door 33, and a driftwood 30 floating and moving in water 40 is provided. Can be stopped at that position, so that the driftwood 30 does not hinder the closing operation of the door 33.

Next, referring to FIGS.
The function of will be described in detail. The stopper 35 is the ceiling 3
Since it is provided in a hanging shape from 4, as shown in FIG. 2, it is possible to prevent the drift of the driftwood 30 or the like only when the upstream water surface 43 of the door 33 approaches the ceiling 34.

On the other hand, as shown in FIG. 3, when the upstream water surface 43 of the door body 33 descends and separates from the ceiling 34, a gap is formed between the lower end of the stopper 35 and the upstream water surface 43. Therefore, the driftwood 30 floating on the upstream water surface 43 flows without being caught by the stopper 35. At this time, since the door body 33 is greatly inclined to the downstream side due to the lowering of the downstream water surface 41, the driftwood 30 floating on the upstream water surface 43 passes over the overflow section 33a of the door body 33 and moves downstream. It falls and does not accumulate on the upstream side.

Therefore, in normal times, when the water is flowing with the door 33 greatly inclined to the downstream side, the driftwood 30 and the like flow downstream without being caught by the stopper 35.
Only when the downstream water surface 41 rises and the door body 33 rises, and the upstream water surface 43 also rises, the stopper 35 prevents the drifting of the driftwood 30 or the like. If necessary, biting of the driftwood 30 or the like can be prevented.

Also, as shown in FIGS.
5 has a large number of slits 35 s for passing water, so that it is possible to prevent a floating substance such as the driftwood 30 from flowing down without reducing the flow rate of water. A similar function can be obtained by using a stopper having a large number of holes formed in the stopper 35 or a stopper having a net-like body instead of the slit 35s.

Further, the stopper 35 is attached to the ceiling 34 so as to be able to move up and down, and the height of the stopper 35 can be freely adjusted by the elevating mechanism 44. And the flow of suspended matter can be effectively prevented. In addition, if the lower portion of the stopper 35 is installed so as to be inserted deeply into the water 40, it is possible to prevent not only the driftwood 30 on the upstream water surface 43 but also the floating material floating in the water 40 from flowing down. In addition, in the case of maintenance or the like, when it is desired to cause floating substances such as driftwood 30 accumulated in the stopper 35 to flow down, the stopper 35 may be raised to a position higher than the upstream water surface 43.

As described above, in the backflow prevention gate 31 of the present embodiment, the water passage 32 is automatically closed when the downstream water surface 41 rises because the door body 33 tilts in accordance with the increase or decrease of the water amount. Backflow can be prevented and the door 3
In a situation where the closure of the driftwood 3 is required,
Since the floating of the floating substance such as 0 is prevented, the closing operation failure of the door 33 due to the biting of the floating substance does not occur.

In the backflow prevention gate 31 of the present embodiment, the sealing member 36 attached to the door body 33 is formed of rubber, but rubber has high sealing properties and can be used in a fluid such as water. Since it has excellent strength and durability, it is suitable as a sealing member.

[0044]

According to the present invention, the following effects can be obtained.

(1) In a backflow prevention gate having a door that is tiltably mounted in a flow path and generates a levitation force in a fluid, a stopper that prevents the floating material from flowing down in the flow path upstream of the door body. Since the floating material is stopped at the position of the stopper, the closing operation of the door body is not hindered.

(2) Since the stopper is provided in the ceiling portion of the flow path in a hanging manner, a function of preventing the floating substance from flowing down can be provided only when the surface of the fluid approaches the ceiling portion. In a normal flow state, the suspended matter does not accumulate in the stopper, and when the closing operation of the door is required, the suspended matter can be prevented from being caught.

(3) By forming an opening for fluid passage in the stopper, fluid passage becomes smooth.
The flow of suspended matter can be effectively prevented without lowering the flow rate of the fluid.

(4) The provision of a lifting mechanism for changing the installation height of the stopper allows the installation height of the stopper to be freely adjusted. In this case, the flow can be effectively prevented. In addition, if the lower portion of the stopper is installed in a state where it is inserted deeply into the fluid, it is possible to prevent not only the suspended matter on the fluid surface but also the suspended matter floating in the fluid from flowing down.

[Brief description of the drawings]

FIG. 1 is a side view showing a backflow prevention gate according to an embodiment.

FIG. 2 is an explanatory diagram showing a function of a stopper of a backflow prevention gate in FIG. 1;

FIG. 3 is an explanatory diagram showing a function of a stopper of a backflow prevention gate in FIG. 1;

FIG. 4 is a side view showing an operation state of a conventional backflow prevention gate.

FIG. 5 is a side view showing a conventional backflow prevention gate.

FIG. 6 is a sectional view taken along line AA of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 30 Driftwood 31 Backflow prevention gate 32 Waterway 33 Door 33a Overflow part 34 Ceiling 35 Stopper 35s Slit 36 Sealing member 37 Side wall 38, 39 Door contact member 40, 42 Water 41 Downstream water surface 43 Upstream water surface 44 Elevating mechanism

Claims (4)

[Claims] A door that is tiltably mounted in a flow path in which a fluid flows in a certain direction and generates a levitation force in the fluid; A backflow prevention gate for closing a road, wherein a stopper is provided in the flow path on the upstream side of the door body to prevent a floating substance floating in the fluid from flowing down. 2. The backflow prevention gate according to claim 1, wherein the stopper is provided so as to hang down from a ceiling portion in the flow path. 3. The backflow prevention gate according to claim 1, wherein an opening for fluid passage is formed in said stopper. 4. The backflow prevention gate according to claim 1, further comprising an elevating mechanism for changing an installation height of the stopper.