JP2001056063A - Flap valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To promote drainage by easily opening a valve element with a small flow by supporting a flap valve to freely swing round the shaft center of a horizontal support shaft, and forming a downward inclined passage on the lower side part of an opening edge of a drain port of a valve easing toward the flat valve. SOLUTION: This flap valve 13 is so constructed that a valve easing 14 is connected to a conduit pipe 11, and a flap valve element 16 for opening and closing a drain port 15 of the valve casing 14 is supported by a holder part 18 provided on the valve casing 14 to freely swing round the shaft center of a horizontal support shaft 17. The axis (b) of an internal passage 14A of the valve casing 14 is inclined at a designated angle θ to the axis (a) of the conduit pipe 11 to become lower as it goes toward the drain port 15. That is, at the inclined lower end part of the internal passage 14A of the valve casing 14, a lower part below the axis (b) of the internal passage 14A is formed like a square to form a downward inclined passage 19 toward the flap valve element 16. Thus, draining can be smoothly performed even in the case of a small quantity of drainage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flap valve mounted on a drain pipe such as a river gutter.

[0002]

2. Description of the Related Art As shown in FIG. 4, a flap valve of this type is provided at the tip of a gutter pipe 3 penetrating a levee 2 for draining from a land side or a wastewater treatment plant to a river 1. Used by mounting. The flap valve 4 has a function of opening at the time of drainage and closing at the time of rising water when the water level of the river 1 rises, thereby preventing the backflow of the river water.

[0003]

In the flap valve having such a function, the valve element 5 is opened by receiving a water flow flowing through the internal flow passage 3A of the gutter tube 3, and is closed by the weight of the valve element 5. When the amount of water flowing through the internal flow passage 3A of the gutter tube 3 is low and the water level is low, it is difficult to open the valve body 5 against its own weight, and drainage to the river 1 is hindered.

The present invention has been made to solve the above-mentioned problem, and can easily open a valve body with a small flow rate to promote drainage. An object of the present invention is to provide a flap valve that can be closed to reliably exhibit a backflow prevention function.

[0005]

In order to solve the above-mentioned problems, a flap valve according to the present invention is provided with a valve box connected to a drain pipe and a flap for opening and closing a drain port of the valve box. A valve body, a support portion for swingably supporting the flap valve body around the axis of the horizontal support shaft, and an inclined flow passage inclined downward toward the flap valve body below the opening edge of the drain port of the valve box. Is formed.

[0006] With the above-described configuration, the drainage that normally flows into the valve box from the drainage pipe flows out from the drainage port by the flap valve body being opened by receiving the water pressure of the water flow. At this time, even if the amount of drainage water flowing into the valve box from the drain pipe is small, the water depth of the water flow increases in the inclined flow path, so that the flaps are smaller than when the internal flow path of the valve box is flat. The water pressure acting on the valve element increases, the opening moment about the horizontal support shaft increases, and the flap valve element opens easily, so that even a small amount of water can be smoothly discharged.

On the other hand, when the water level on the outer water surface increases due to rainfall or the like and the outer water surface becomes higher than the inner water surface of the valve box, the flap valve body is fully closed due to the water pressure acting due to the water level difference and the weight of the valve body. To prevent backflow. Claim 2
The present invention relates to a flap valve, which swings around the axis of a horizontal support shaft integrally with the flap valve body, and has a guide arm extending in the front-rear direction of the valve body, and a guide arm of the weight arm. One end of the weight arm is located forward of the horizontal support shaft, the other end is located behind the horizontal support shaft, and the weight is located at one end of the weight arm when the flap valve is fully closed. To generate a moment in the closing direction, and when the flap valve is opened, the weight moves to the other end of the weight arm to generate a moment in the opening direction.

With the above structure, even if the amount of waste water flowing into the valve box from the drain pipe is small, when the flap valve starts to open due to the water pressure acting on the inclined flow path, the weight arm is moved to the flap valve. Swinging around the axis of the horizontal support shaft integrally with the body, the guide groove has a downward slope toward the rear of the valve body, and the weight moves to the other end of the weight arm along the guide groove and the moment in the opening direction As a result, the flap valve body easily opens, so that even a small amount of water can be discharged smoothly.

On the other hand, when the outer water level becomes higher than the inner water level of the valve box, the flap valve is fully closed by the water pressure acting due to the water level difference and the weight of the valve, and the weight is positioned at one end of the weight arm. As a result, a sealing moment is increased due to an increase in surface pressure, and backflow is reliably prevented.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 and FIG. 2, a gutter 11 is a conduit for draining water from a land side or a wastewater treatment plant to a river 12, and is disposed so as to penetrate an embankment (not shown). At the time of drainage, the river 1
2 is equipped with a flap valve 13 which closes when the water level rises and prevents backflow of river water.

The flap valve 13 includes a valve box 14 connected to the gutter pipe 11, a flap valve element 16 for opening and closing a drain port 15 of the valve box 14, and a flap valve element 16 which is connected to a horizontal support shaft 17 around the axis thereof. And a holder 18 provided on the valve box 14 for swingably supporting. On the other hand, the internal flow path 14A of the valve box 14 is inclined at a predetermined angle θ with respect to the axis a of the gutter tube 11 so that the axis b becomes lower toward the drain port 15. As shown in FIG. 3, the lower portion of the opening edge of the drain port 15 of the valve box 14, that is, the lower portion of the inclined lower end of the internal flow path 14 </ b> A below the axis b of the internal flow path 14 </ b> A is formed in a square shape. A downwardly inclined flow path 19 is formed toward the flap valve element 16.

The operation of the above configuration will be described below. Normally, the drainage flowing from the drain pipe 11 into the internal flow path 14A of the valve box 14 opens the flap valve body 16 by the water pressure of the water flow, and flows out from the drain port 15 to the outside. At this time, the internal flow path 14 of the valve box 14
Even if the amount of drainage water flowing into A is small, the internal flow path 14A is inclined, and the water depth of the water flow increases in the inclined flow path 19, so that the internal flow path 14A of the valve box 14 is flat. In comparison, the water pressure acting on the flap valve body 16 increases, the opening moment about the axis of the horizontal support shaft 17 increases, and the flap valve body 16 is easily opened, so that even a small amount of water is discharged smoothly. be able to.

On the other hand, when the water level on the outer water surface increases due to rainfall or the like, and the outer water surface becomes higher than the inner water surface of the valve box 14, the flap valve body 16 is fully driven by the water pressure acting due to the water level difference and the weight of the valve body. Close to prevent backflow. FIG. 3 shows another embodiment of the present invention.
In FIG. 3, the flap valve body 16 is provided with a weight arm 20 that swings integrally around the axis of the horizontal support shaft 17. The weight arm 20 has a guide groove 21 extending in the front-rear direction of the flap valve body 16, and has one end on the horizontal support shaft 1.
7, the other end is located behind the horizontal support shaft 17, and the guide groove 2 when the flap valve body 16 is fully closed.
1 becomes a downward slope toward the front, and the guide groove 21 becomes a downward slope toward the rear when the flap valve body 16 is opened.
A weight 22 that moves along the guide groove 21 is disposed on the weight arm 20, and the weight 22 is located at one end of the weight arm 20 when the flap valve body 16 is fully closed, and generates a closing moment. When the flap valve 16 is opened, it moves to the other end of the weight arm 20 to generate an opening moment.

With the above configuration, when the flap valve body 16 starts to open due to the water pressure acting on the inclined flow path 19,
The weight arm 20 swings about the axis of the horizontal support shaft 17 integrally with the flap valve body 16, the guide groove 21 is inclined downward toward the rear of the flap valve body 16, and the weight 22 extends along the guide groove 21. Since it moves to the other end of the weight arm 20 to generate a moment in the opening direction, the flap valve body 16 is easily opened, and the amount of waste water flowing from the drain pipe 11 to the internal flow path 14A of the valve box 14 is small. Even in this case, drainage can be performed smoothly.

On the other hand, when the external water level is higher than the internal water level of the valve box 14, the flap valve 16 is fully closed due to the water pressure acting due to the water level difference and the weight of the valve, and the guide groove 21 of the weight arm 20 is closed. Since the weight 22 is located at one end of the weight arm 20 and generates a closing moment, the sealing performance is increased due to the increase of the surface pressure, and the backflow is reliably prevented. I do.

[0016]

As described above, according to the present invention, even if the amount of waste water flowing into the valve box from the drain pipe is small,
The water pressure acting on the flap valve body in the inclined flow path increases, the opening moment about the axis of the horizontal support shaft increases, and the flap valve body opens easily, so that even a small amount of water can be discharged smoothly. it can. Also, when the flap valve starts to open, it moves to the other end of the weight arm to generate an opening moment, and the flap valve easily opens, so that even a small amount of water can be smoothly discharged. The weight is located at one end of the weight arm in the state where the flap valve body is fully closed in the event of an abnormality, and a moment in the closing direction is generated. Therefore, the sealing performance is increased by the increase in the surface pressure, and the backflow can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a flap valve according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line XX of FIG.

FIG. 3 is a sectional view showing a flap valve according to another embodiment of the present invention.

FIG. 4 is a schematic view showing a flap valve in a conventional gutter pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Gutter pipe 12 River 13 Flap valve 14 Valve box 14A Internal flow path 15 Drainage port 16 Flap valve body 17 Horizontal support shaft 18 Holder part 19 Inclined flow path 20 Weight arm 21 Guide groove 22 Weight

Claims (2)

[Claims] 1. A valve box connected to a drain pipe, a flap valve for opening and closing a drain port of the valve box, and a supporting portion for swingably supporting the flap valve about an axis of a horizontal support shaft. And a flap valve having a downwardly sloped flow path formed toward the flap valve body below the opening edge of the drain port of the valve box. 2. A weight arm having a guide groove which swings around the axis of a horizontal support shaft integrally with a flap valve body and extends in the front-rear direction of the valve body, and a weight which moves along the guide groove of the weight arm. The weight arm has one end positioned forward of the horizontal support shaft, the other end positioned rearward of the horizontal support shaft, and when the flap valve is fully closed, the weight is positioned at one end of the weight arm to close the moment. 2. The flap valve according to claim 1, wherein when the flap valve body is opened, the weight moves to the other end of the weight arm to generate an opening moment.