JP2023050362A - Backflow prevention joint - Google Patents

Abstract

To provide a backflow prevention valve that can be attached to a drain basin or the like and can prevent backflow of waste water by reliably closing a valve pipe with a valve body even in an emergency when backflow water occurs.MEANS FOR SOLVING THE PROBLEM: A backflow prevention joint comprises: a valve pipe that has an inlet and an outlet; a valve body that is rotatably attached to the valve pipe to open and close the outlet of the valve pipe; link means that has one end rotatably attached to the valve pipe and the other end rotatably attached to the valve body; and a buoyancy generating part that is attached to the link means and rises and falls according to height of a liquid surface. The link means rotates the valve body so as to close the outlet of the valve pipe as the buoyancy generating part rises, and rotates the valve body so as to open the outlet of the valve pipe as the buoyancy generating part descends.SELECTED DRAWING: Figure 1

Description

The present invention relates to a backflow prevention joint that is attached to the inlet/outlet of drainage facilities such as manholes, public basins, and drainage basins, and to the outlet of water channels, and in particular, assists and reliably opens and closes the valve body via link means. It relates to a backflow prevention joint with float means for

In general, the drainage pipes connected to each drainage system are used to mitigate sudden changes in the amount of wastewater discharged from toilets and other drainage facilities, or for the purpose of removing and inspecting foreign objects such as garbage. The wastewater collected in the drainage basin is collected in the drainage basin installed in the residential lot, and the wastewater collected in the drainage basin is discharged to the sewage main via the public basin or the manhole.

However, due to abnormal weather in recent years, there have been frequent cases where a large amount of rainwater flows into the sewer main in a short period of time. There is a problem that the overflowing drainage flows back through a drainage basin or the like, and the back-flowing drainage spouts out from the indoor drainage equipment connected to the drainage pipe.

For this reason, in order to prevent the wastewater flowing back from the sewage main pipe from overflowing from the indoor drainage equipment through the drainage basin, etc. As described in JP-A-2010-248904 (Patent Document 3) and JP-A-2010-248904, a check valve to be attached to the inlet of a drain basin has been developed.

In the check valve described in Patent Document 1, the valve seat surface of the valve pipe outlet is tilted forward to provide a gap between the valve body and the valve seat surface during normal operation, thereby facilitating smooth drainage. When the water level rises, the valve body pressed from the front by the backflow water rotates backward and comes into contact with the valve seat surface, thereby preventing the backflow of wastewater to the upstream side. In addition, the check valve described in Patent Document 2 has the configuration of the check valve described in Patent Document 1, in addition to the structure of the check valve described in Patent Document 1, by configuring all or part of the valve body as a buoyancy generating part, The opening and closing of the valve body is made to operate more reliably.

However, in the check valves described in Patent Literatures 1 and 2, the valve body is merely suspended swingably at the valve pipe outlet. In addition, especially when a large amount of rainwater flows into the drainage basin at once due to a typhoon or torrential rain, etc., the valve body may Unstable rocking occurs repeatedly between the closing side and the opening side of the valve pipe outlet. Therefore, in the non-return valves described in Patent Documents 1 and 2, if rainwater flows into a drainage basin or the like at the timing when the valve body swings to open the valve pipe outlet, the buoyancy of the valve body is reversed. As a result, the valve body cannot return to the closing direction while the valve pipe outlet is open, and there is a problem that it is impossible to prevent the waste water from flowing backward to the upstream side.

In addition, in the check valve described in Patent Document 3, the end face of the valve seat is inclined from the upstream side to the downstream side as it goes from the upper part to the lower part, so that the valve body normally contacts the valve seat. The forward flow of the waste water lifts the valve body to ensure the flow of the waste water, and in an emergency, the valve body maintains a state of contact with the valve seat to block the reverse flow of the waste water. It is.

That is, the backflow prevention valve described in Patent Document 3 preferentially prevents backflow water temporarily generated due to a guerrilla rainstorm or the like from flowing backward to the upstream side rather than ensuring the flow of forward flow drainage in normal times. Therefore, there is a problem that the valve body cannot move to the opening side reliably and becomes unstable (drainage clogging occurs) even in normal times with a small amount of forward flow drainage. there were.

In addition, by providing a buoyancy generating part separately from the valve body, the valve body can be opened and closed more reliably during normal operation and reverse flow. 4) are known.

However, in the flap gate described in Patent Document 4, the gate body is swingably suspended at the outlet of the water channel, and the float mechanism that assists the opening and closing operation of the gate body floats so as not to restrict the movement of the gate body.・It is in contact with the gate body through the roller attached to the tip of the lever and is not connected. Therefore, even in the flap gate described in Patent Document 4, if rainwater flows backward at the timing when the gate body swings toward the opening side of the waterway, the gate body detaches from the float mechanism and the waterway opens. As a result of not being able to return to the closing direction while the outlet is open, there is a problem that it becomes impossible to prevent the waste water from flowing backward to the upstream side.

Japanese Patent Application Laid-Open No. 2020-153508 JP 2018-204198 A JP 2010-248904 A Utility Model Registration No. 3200989

Therefore, the present invention can be attached to the inlet/outlet of drainage facilities such as manholes, public basins, drainage basins, etc., and the outlet of water channels. The smooth operation of the forward flow drainage can be guaranteed by this operation, and even in an emergency such as when a large amount of rainwater flows into the drainage basin at once, the valve body reliably closes the valve pipe. To provide a backflow prevention valve capable of preventing backflow of waste water to the upstream side by operating in a reverse direction.

The inventors of the present invention have studied the valve element rotation mechanism and the mechanism for assisting the rotation mechanism for check valves and flap gates that are attached to the inlet/outlet of drainage facilities such as drainage basins and the drain ports of water channels. As a result of extensive research on the mechanism, structure, etc., a buoyancy generating part that rises and falls according to the height of the liquid surface is provided separately from the valve body attached to open and close the outlet of the valve pipe, and Between the valve pipe and the valve body, the valve body is rotated so as to close the outlet of the valve pipe as the buoyancy generating part rises, and the valve body opens the outlet of the valve pipe as the buoyancy generating part descends. The inventors have found that the above-mentioned problem can be solved by connecting the link means for rotating the shaft, and have completed the present invention.

That is, according to the present invention, a valve tube having an inlet and an outlet, a valve body rotatably attached to the valve tube so as to open and close the outlet of the valve tube, and a valve body having one end rotatable to the valve tube a link means rotatably attached at the other end to the valve body; and a buoyancy generating part attached to the link means and rising and falling according to the height of the liquid surface. The link means rotates the valve body so as to close the outlet of the valve pipe as the buoyancy generating part rises, and the valve body closes the outlet of the valve pipe as the buoyancy generating part descends. There is provided a backflow prevention joint characterized by pivoting the to open.

Further, in the present invention, it is preferable that one end of the link means is rotatably attached to the valve tube at a fulcrum at a position different from the fulcrum at which the valve body rotates. and a second connecting arm rotatably connected to the first connecting arm and having the other end.

As described above, in the backflow prevention joint of the present invention, the buoyancy generating section provided separately from the valve element of the check valve rises and falls according to the liquid level of the backflowing waste water. Between the valve pipe and the valve body, the valve body rotates so as to close the outlet of the valve pipe as the buoyancy generating part rises, and the valve body closes the outlet of the valve pipe as the buoyancy generating part descends. A link means is connected for pivoting to open.

For this reason, even in a situation where a large amount of rainwater flows back at once and wraps around to the opening side (upstream side) of the valve body, the buoyancy generating part raised by the backflow water reliably moves in the direction to close the valve body via the link means. Since it is activated, it is possible to reliably prevent backflow water from flowing further upstream. In normal times, the fulcrum of the valve pipe that supports the valve body exerts a moment in the direction of opening the valve body due to the weight of the buoyancy generating part, so the valve body does not interfere and the forward flow of the drainage is smooth. can be guaranteed.

The backflow prevention joint of the present invention can be attached to the inlet/outlet of drainage facilities such as manholes, public basins, and drainage basins, as well as the outlet of waterways. In particular, the valve body is provided with a guide arm extending in a direction different from the direction in which the valve body extends across the fulcrum at which the valve body rotates in a side view, and the second connecting arm is rotatable to the guide arm. By connecting, the up-and-down motion of the buoyancy generating part can be efficiently converted into the opening and closing motion of the valve body.

In this case, it is preferable that the buoyant force generator is arranged downstream of the fulcrum at which the valve body rotates. In addition, since this type of backflow prevention joint must provide an operating space for the buoyancy generating part on the downstream side of the valve body, it can be attached to the inlet of drainage facilities such as manholes, public basins, drainage basins, etc. Suitable for

In the backflow prevention joint of the type described above, in order to increase the force generated by the upward and downward movements of the buoyant force generator and transmit it to the valve body via the second connecting arm and the second connecting arm, the buoyant force generator is provided with an extension arm, and the buoyancy generator is attached to the second connecting arm through the extension arm.

Further, in the backflow prevention joint of the present invention, the second connecting arm is rotatably connected to the valve body at a fulcrum at a position different from the fulcrum at which the valve body rotates in a side view. It is also possible to efficiently convert the up-and-down motion into the opening and closing motion of the valve body.

In this case, it is preferable that the buoyancy generating portion is arranged upstream of the fulcrum at which the valve body rotates. In addition, since this type of backflow prevention joint must provide an operating space for the buoyancy generating part on the upstream side of the valve body, it is suitable for attachment to the outlet of drainage facilities such as manholes, public basins, and drainage basins.

In the above-described type of backflow prevention joint in which the buoyant force generating portion is located upstream of the valve body, the force generated by the upward and downward movement of the buoyant force generating portion is increased to increase the force through the first connecting arm and the first connecting arm. In order to transmit the force to the valve body, it is effective to provide the buoyancy generator with an extension arm and attach the buoyancy generator to the first connecting arm via the extension arm.

In either type of locating the buoyancy generator downstream or upstream of the valve body, the buoyancy generator should have a lower specific gravity than water in order to ensure upward movement of the buoyancy generator due to backflow of water. It is preferable to be In addition, in order for the valve body to open the outlet of the valve pipe under normal conditions, the moment acting in the direction of opening the valve body due to the weight of the buoyancy generating part at the fulcrum of the valve pipe that supports the valve body It is preferable to set the moment larger than the moment acting in the direction of closing the valve body due to the body's own weight.

In normal times, the gap between the valve body and the valve pipe outlet guarantees the flow of waste water. , the end face is preferably formed so as to be inclined from the downstream side to the upstream side as it goes from the top to the bottom.

According to the present invention, a valve tube having an inlet and an outlet, a valve body rotatably mounted on the valve tube to open and close the outlet of the valve tube, and one end rotatably attached to the valve tube. and a buoyancy generating part attached to the link means and rising and falling according to the height of the liquid surface. The link means rotates the valve body so as to close the outlet of the valve pipe as the buoyancy generating part rises, and the valve body opens the outlet of the valve pipe as the buoyancy generating part descends. A backflow prevention joint is provided which is characterized in that it rotates in the following manner.

As described above, in the backflow prevention joint of the present invention, the buoyancy generating section provided separately from the valve element of the check valve rises and falls according to the liquid level of the backflowing waste water. Between the valve pipe and the valve body, the valve body rotates so as to close the outlet of the valve pipe as the buoyancy generating part rises, and the valve body closes the outlet of the valve pipe as the buoyancy generating part descends. A link means is connected for pivoting to open.

For this reason, even in a situation where a large amount of rainwater flows back at once and wraps around to the opening side (upstream side) of the valve body, the buoyancy generating part raised by the backflow water reliably moves in the direction to close the valve body via the link means. Since it is activated, it is possible to reliably prevent backflow water from flowing further upstream. In normal times, the fulcrum of the valve pipe that supports the valve body exerts a moment in the direction of opening the valve body due to the weight of the buoyancy generating part, so the valve body does not interfere and the forward flow of the drainage is smooth. can be guaranteed.

1 is a perspective view showing the entire backflow prevention joint according to one embodiment of the present invention; FIG. 2 is a side view showing a state in which a valve body opens a valve pipe in the backflow prevention joint shown in FIG. 1; FIG. FIG. 3 is a cross-sectional view of the backflow prevention joint shown in FIG. 2 taken along a cross section passing through the central axis of the valve pipe; 2 is a side view showing a state in which a valve body closes a valve pipe in the backflow prevention joint shown in FIG. 1; FIG. FIG. 5 is a cross-sectional view of the backflow prevention joint shown in FIG. 4 taken along a cross section passing through the central axis of the valve pipe; FIG. 2 is a cross-sectional view of a drain basin showing a mode in which the backflow prevention joint shown in FIG. 1 is attached to the drain basin; FIG. 5 is a perspective view showing the entire backflow prevention joint according to another embodiment of the present invention; FIG. 8 is a side view showing a state in which the valve body opens the valve pipe in the backflow prevention joint shown in FIG. 7; FIG. 9 is a cross-sectional view of the backflow prevention joint shown in FIG. 8 taken along the central axis of the valve pipe; FIG. 8 is a side view showing a state in which the valve body closes the valve pipe in the backflow prevention joint shown in FIG. 7; FIG. 11 is a cross-sectional view of the backflow prevention joint shown in FIG. 10 taken along the central axis of the valve pipe; FIG. 8 is a cross-sectional view of a drainage basin showing a mode in which the backflow prevention joint shown in FIG. 7 is attached to the drainage basin;

A backflow prevention joint according to an embodiment of the present invention will be described in detail below with reference to the drawings. The present invention is not limited to the embodiments shown below, and various modifications are possible without departing from the technical idea of the present invention.

<First Embodiment>
FIG. 1 shows a perspective view showing the entire backflow prevention joint 1 according to the first embodiment of the present invention.

As shown in FIG. 1, the backflow prevention joint 1 of the first embodiment includes a valve tube 2 having an inlet 20 and an outlet 21, and a valve tube 2 pivoting on the valve tube 2 to open and close the outlet 21 of the valve tube 2. It is equipped with a valve element 3 that can be attached and a buoyancy generator 4 that ascends and descends according to the height of the liquid surface. Between the valve pipe 2 and the valve body 3, a first connecting arm 50 having a first end 500 rotatably attached to the valve pipe 2 and a first connecting arm 50 are provided. A linking means 5 is mounted which consists of a second connecting arm 51 which is movably connected and whose second end 510 is pivotally attached to the valve body 3 .

In the backflow prevention joint 1 of the first embodiment, the link means 5 consisting of the first connecting arm 50 and the second connecting arm 51 is configured so that the valve element 3 moves toward the outlet of the valve tube 2 as the buoyancy generating section 4 rises. 21 is closed, and the valve element 3 is rotated to open the outlet 21 of the valve pipe 2 as the buoyancy generating part 4 descends.

FIG. 2 shows a side view of the backflow prevention joint 1 shown in FIG. 1 with the valve body 3 opening the valve pipe 2, and FIG. 3 shows the backflow prevention joint shown in FIG. 1 is cut along the central axis of the valve pipe 2. FIG. 4 shows a side view of the backflow prevention joint 1 shown in FIG. 1, in which the valve body 3 closes the valve pipe 2. FIG. 5 shows the backflow prevention joint 1 shown in FIG. A cross-sectional view of the joint 1 cut along the central axis of the valve pipe 2 is shown.

<Valve>
In the backflow prevention joint 1 of the first embodiment, vinyl chloride resin is used as the material of the valve pipe 2, but the material to be used is not particularly limited, and known materials such as plastic can be mainly used. . Further, the valve pipe 2 is composed of a short straight pipe with a circular cross section, but it is not necessary that the entire pipe is a straight pipe, and a curved pipe portion may be included in part. Also, the diameter of the valve pipe 2 does not necessarily have to be uniform, and for example, it may be configured like a different diameter pipe joint in which the diameters of the inlet 20 and the outlet 21 are different.

In the first embodiment, the outlet 21 of the valve pipe 2 is formed such that its end surface (valve seat surface) is inclined from the downstream side to the upstream side as it goes from top to bottom. For this reason, in the backflow prevention joint 1, a gap is formed between the valve body 3 and the outlet 21 of the valve pipe 2 in normal times to ensure a smooth flow of the forward flow drainage, and only when the water level increases, the valve body 3 is closed to the outlet. 21 is closed to prevent backflow of waste water.

However, in the first embodiment, when the drain surface has not reached the buoyancy generating section 4, the valve body 3 is set so that a moment acts on the valve body 3 in the direction of opening the valve body 3 due to the weight of the buoyancy generating section 4. 2 and 3), the end surface (valve seat surface) of the outlet 21 of the valve pipe 2 does not necessarily have to be inclined as described above. The surface may be inclined from the upstream side toward the downstream side.

A fulcrum O for rotatably supporting the valve body 3 is provided above the outlet 21 of the valve tube 2, and a first connecting arm 50 of the link means 5 is provided at a position different from the fulcrum O as viewed from the side. A pair of support arms 22 are formed with a fulcrum P for rotatably supporting the ends 500 of the. The shape and mounting position of the support arm 22 are not particularly limited, but in the first embodiment, since it extends upward from the outer periphery of the valve pipe 2, the valve pipe 2 can be inserted into the inlet 60 of the drain basin 6 or the like. When the backflow prevention joint 1 is attached to the backflow prevention joint 1, not only does the support arm 22 come into contact with the end face of the inflow port 60 and function as a stopper (see FIG. 6), but the fulcrum P is different from the fulcrum O in one member. It is also convenient in that it can be placed at any position.

The structure for rotatably supporting the valve body 3 and the first end portion 500 of the first connecting arm 50 at the fulcrum O and the fulcrum P of the support arm 22 is not particularly limited, but in the first embodiment, The fulcrum O has a structure in which a pivot shaft provided on the upper portion of the valve body 3 is rotatably gripped from both sides by bearings respectively formed on the pair of support arms 22, and the fulcrum P is the first connection. A rotating shaft provided at the first end portion 500 of the arm 50 is rotatably gripped from both sides by bearings formed on each of the pair of support arms 22 .

In addition, for example, when inserting the valve pipe 2 into the inlet 60 of the drain basin 6 and attaching the backflow prevention joint 1 (FIG. 6), the outer circumference of the valve pipe 2 and the inner wall surface of the inlet 60 A ring-shaped rubber valve tube packing 23 is attached to seal the gap between the valve tube 2 and the valve tube packing 23 .

<Valve>
In the backflow prevention joint 1 of the first embodiment, vinyl chloride resin is used as the material of the valve body 3, but the material to be used is not particularly limited, and known materials such as plastic can be mainly used. . The shape of the valve body 3 may be any shape as long as it can abut on the outlet 21 of the valve tube 2 and completely block the outlet 21. In the first embodiment, the outlet 21 of the valve tube 2 is substantially circular. Since it has a shape, it has a substantially circular shape when viewed from the front in accordance with the shape of the outlet 21 . Further, on the contact surface of the valve body 3 that contacts the end surface (valve seat surface) of the outlet 21 of the valve pipe 2, a valve body packing is provided to improve the sealing performance with the outlet 21 when the valve body 3 is closed. The valve body packing 32 is fitted in a fitting groove 33 formed in the upstream surface 30 of the valve body 3 .

As shown in FIGS. 2 and 4, in order to rotatably connect the second connecting arm 51 to the valve body 3 at the fulcrum Q, the valve body 3 has a fulcrum O at which the valve body 3 rotates when viewed from the side. A guide arm 34 extending in a direction different from the direction in which the valve body 3 extends is provided. That is, in the above configuration, the guide arm 34 serves as the point of force or the point of action, and the valve body 3 serves as the point of action or the point of force utilizing the principle of leverage. For this reason, in the backflow prevention joint 1 of the first embodiment, by connecting the second connecting arm 51 to the guide arm 34, the upward and downward movement generated by the buoyancy generating section 4 is converted into the opening and closing operation of the valve body 3. can be converted efficiently.

As shown in FIGS. 3 and 5, the valve body 3 is formed such that the downstream surface 31 is curved so as to be recessed from the downstream side to the upstream side. Therefore, the valve body 3 is subjected to a larger force (resistance) by the reverse flow of water that collides with the downstream surface 31 than by the forward flow of water that collides with the upstream surface 30 . For this reason, the valve body 3 operates to reliably close the outlet 21 of the valve pipe 2 when there is a flow of waste water flowing back upstream through the backflow prevention joint 1, It is also possible to prevent an erroneous operation to open the outlet 21 of the valve tube 2 due to the difference in resistance generated between the front and back surfaces 30 and 31 .

Although not shown, in the first embodiment, the valve body 3 may have buoyancy. In the backflow prevention joint 1 of the first embodiment, the outlet 21 of the valve pipe 2 is formed so as to incline from the downstream side to the upstream side as it goes from the upper part to the lower part. When backflow occurs, the valve body 3 operates to more easily and reliably close the outlet 21 of the valve pipe 2. - 特許庁

The means for imparting buoyancy to the valve body 3 is not particularly limited, but as a structure for imparting buoyancy, for example, a closed space is provided between the upstream surface and the downstream surface of the valve body, and the valve body has a hollow structure. and a method of providing a second buoyant force generator having a specific gravity smaller than that of water on the downstream surface 31 of the valve body 3 .

<Link Means>
In the backflow prevention joint 1 of the first embodiment, the link means 5 includes a first connecting arm 50 having a first end 500 rotatably attached to the support arm 22 of the valve tube 2 at the fulcrum P; a second connecting arm 51 rotatably connected to the first connecting arm 50 at a fulcrum R and having a second end 510 rotatably attached to the guide arm 34 of the valve body 3 at a fulcrum Q; consists of That is, one end of the link means 5 is rotatably attached to the valve tube 2 at the fulcrum P, and the other end is rotatably attached to the valve body 3 at the fulcrum Q.

The shape and configuration of the first connecting arm 50 and the second connecting arm 51 are not particularly limited as long as they do not interfere with each other's operations. In the first embodiment, the first connecting arm 50 has a rod-like shape with rotation shafts formed at both ends (fulcrums P, R), and the second connecting arm 51 is the first connecting arm. It is composed of a pair of rod-like sub-arms 511 and 512 so that the rotation axis at the fulcrum R of the arm 50 and the rotation axis at the fulcrum Q of the valve body 3 can be gripped from both sides by a pair of bearings.

In the first embodiment, vinyl chloride resin is used as the material for the first connecting arm 50 and the pair of rod-shaped sub-arms 511 and 512, but the material to be used is not particularly limited, and is mainly made of plastic or the like. A known material can be used. In the specification of the present application, "one end", "other end" and "end portion" of the link means 5 do not strictly mean the end faces of the ends of the arms 50, 511 and 512. means "one end", "other end" and "end" of the link means 5, which may be provided with pivots or bearings.

<Buoyancy generator>
In the backflow prevention joint 1 of the first embodiment, the buoyancy generating part 4 assists and ensures the opening and closing operation of the valve body 3 so that the valve body 3 does not malfunction in normal times and in abnormal cases. 5 is non-rotatably attached to the second connecting arm 51 . Further, in the first embodiment, the force generated by the upward and downward movement of the buoyant force generator 4 is increased and transmitted to the valve body 3 via the second connecting arm 51 and the second connecting arm 51. , the buoyancy generator 4 is attached to a second connecting arm 51 via a round bar-shaped extension arm 40 .

The buoyancy generator 4 may have a specific gravity smaller than that of water so as to generate buoyancy against backflow water, and its shape, structure, material, and the like are not particularly limited. In the first embodiment, the buoyancy generating part 4 is made of a plastic hollow structure because it has low resistance to backflow water and is easy to manufacture. The structure is preferably a hollow sphere. In addition, the buoyancy generator 4 is positioned at the fulcrum O of the valve pipe 2 that supports the valve body 3 in order to ensure that the valve body 3 opens the outlet 21 of the valve pipe 2 in a normal state. The weight of the buoyancy generating section 4 is set so that the moment acting in the direction of opening the valve body 3 due to its own weight is greater than the moment acting in the direction of closing the valve body 3 due to its own weight.

FIG. 6 shows a cross-sectional view of the drain basin 6 showing how the backflow prevention joint 1 shown in FIG. 1 is attached to the drain basin 6 .

The drainage basin 6 shown in FIG. 6 is a partially enlarged lower portion of a general drainage basin 6, and includes an inlet 60, an outlet 61, and an invert connecting the inlet 60 and the outlet 61. and above the inverted section 62 has an opening 63 for connecting a riser (not shown) having an access port. In addition, in the first embodiment, the drainage basin 6 is entirely made of vinyl chloride resin, but it may be made of other known plastic resin, concrete material, or a combination of plastic resin and concrete material.

In the backflow prevention joint 1 of the first embodiment, as shown in FIGS. 2 to 5, the buoyancy generator 4 is arranged downstream of the fulcrum O at which the valve body 3 rotates. For this reason, the backflow prevention joint 1 of the first embodiment must provide an operating space for the buoyancy generating part 4 on the downstream side of the valve body 3. It is suitable for installation on the inlet 60 side of a waterway or the outlet (not shown) of a waterway.

In the specification of the present application, the expression that the buoyant force generating portion 4 is arranged downstream of the fulcrum O at which the valve body 3 rotates means that the buoyant force generating portion 4 generates buoyancy at the positions where the buoyant force generating portion 4 is raised and lowered. The "center" means an aspect arranged downstream of a vertical plane passing through the rotation axis of the fulcrum O at which the valve body 3 rotates. Therefore, in the first embodiment, the link means 5 that is connected to the buoyancy generating portion 4 is also arranged downstream of the fulcrum O at which the valve element 3 rotates.

<Operation Mode of Buoyancy Generating Part and Valve>
As shown in FIGS. 2 and 3, when the liquid level in the vicinity of the backflow prevention joint 1 is normally lowered, the buoyancy generator 4 also descends due to its own weight as the liquid level lowers. Since the second connecting means 51 is connected to the first connecting means 50 rotatably connected to the fulcrum P of the valve tube 2 at the fulcrum R, the downward movement of the buoyant force generator 4 is The coupling means 51 is rotated counterclockwise around the fulcrum R in FIGS. Therefore, the counterclockwise rotational movement of the second coupling means 51 about the fulcrum R results in the guide arm 34 rotating clockwise about the fulcrum O via the fulcrum Q. , the clockwise rotational motion of the guide arm 34 rotates the valve body 3, which extends in a direction different from the direction in which the guide arm 34 extends across the fulcrum O, clockwise in FIGS. That is, the valve tube 2 is rotated so as to open the outlet 21 .

As shown in FIGS. 4 and 5, when backflow water occurs in the vicinity of the backflow prevention joint 1 and the liquid level rises, the buoyancy generator 4 also rises as the liquid level rises. Since the second connecting means 51 is connected to the first connecting means 50 rotatably connected to the fulcrum P of the valve tube 2 at the fulcrum R, the upward movement of the buoyant force generator 4 is The connecting means 51 is rotated clockwise around the fulcrum R in FIGS. Therefore, the clockwise rotational movement of the second coupling means 51 about the fulcrum R results in the counterclockwise rotation of the guide arm 34 about the fulcrum O via the fulcrum Q. , the counterclockwise rotational motion of the guide arm 34 causes the valve body 3 extending in a direction different from the direction in which the guide arm 34 extends across the fulcrum O to move counterclockwise around the fulcrum O in FIGS. It is rotated around, that is, to close the outlet 21 of the valve tube 2 .

As described above, in the backflow prevention joint 1 of the first embodiment, the valve body 3 rotates the link means 5 connected to the valve body 3 at the fulcrum Q in order to assist the opening/closing operation of the valve body 3. Since the fulcrum P is connected to the valve tube 2 at the fulcrum P which is different from the fulcrum O, the upward and downward movement of the buoyancy generator 4 attached to the link means 5 can be efficiently converted into the opening and closing operation of the valve body 3 . . Further, in the backflow prevention joint 1 of the first embodiment, for example, by adjusting the length of the guide arm 34 of the valve body 3 and the length of the extension arm 40 of the buoyancy generation section 4, the up-and-down movement of the buoyancy generation section 4 is controlled. The force generated by this can be converted into a force of a desired magnitude and easily transmitted to the valve body 3 so as to assist the opening/closing operation.

Therefore, in the backflow prevention joint 1 of the first embodiment, the valve body 3 is positively opened by the self-weight of the buoyancy generating part 4 in normal times to ensure a smooth flow of waste water in the forward flow. , the valve body 3 is positively closed by the buoyancy of the buoyancy generator 4, so that the reverse flow of waste water can be blocked reliably.

<Second embodiment>
FIG. 7 shows a perspective view showing the entire backflow prevention joint 1a according to the second embodiment of the present invention.

As shown in FIG. 7, the backflow prevention joint 1a of the second embodiment includes a valve tube 2a having an inlet 20a and an outlet 21a, and a valve tube 2a pivoted to open and close the outlet 21a of the valve tube 2a. It is provided with a valve element 3a that can be attached and a buoyancy generator 4a that ascends and descends according to the height of the liquid surface. Between the valve pipe 2a and the valve body 3a, a first connecting arm 50a having a first end portion 500a rotatably attached to the valve pipe 2a and a first connecting arm 50a which rotates around the first connecting arm 50a are provided. A linking means 5a is mounted which consists of a second connecting arm 51a which is movably connected and whose second end 510a is rotatably attached to the valve body 3a.

In the backflow prevention joint 1a of the second embodiment, the link means 5a consisting of the first connecting arm 50a and the second connecting arm 51a is configured such that the valve body 3a moves toward the outlet of the valve pipe 2a as the buoyancy generating portion 4a rises. 21a is rotated to close, and as the buoyancy generating portion 4a descends, the valve body 3a rotates to open the outlet 21a of the valve pipe 2a.

FIG. 8 shows a side view of the backflow prevention joint 1a shown in FIG. 7 with the valve body 3a opening the valve pipe 2a, and FIG. 9 shows the backflow prevention joint shown in FIG. A cross-sectional view obtained by cutting 1a along the central axis of the valve tube 2a is shown. 10 shows a side view of the backflow prevention joint 1a shown in FIG. 7 in which the valve body 3a closes the valve tube 2a, and FIG. 11 shows the backflow prevention joint 1a shown in FIG. A cross-sectional view of the joint 1a cut along the central axis of the valve tube 2a is shown.

<Valve>
In the backflow prevention joint 1a of the second embodiment, vinyl chloride resin is used as the material of the valve pipe 2a, but the material to be used is not particularly limited, and known materials such as plastic can be mainly used. . The valve pipe 2a is composed of a short straight pipe with a circular cross section other than the outlet 21a. Also, the diameter of the valve pipe 2a does not necessarily have to be uniform, and for example, the inlet 20a and the outlet 21a may be configured as different diameter pipe joints having different diameters.

In the second embodiment, the outlet 21a of the valve pipe 2a is formed such that its end surface (valve seat surface) is inclined from the upstream side to the downstream side as it goes from top to bottom. However, in the second embodiment, when the drain surface has not reached the buoyancy generating portion 4a, the weight of the buoyancy generating portion 4a is set to act on the valve body 3a in the direction of opening the valve body 3a. 8 and 9), the end surface (valve seat surface) of the outlet 21a of the valve pipe 2a does not necessarily have to be inclined as described above. The surface may be inclined from the downstream side toward the upstream side.

A valve body 3a is rotatably supported at a fulcrum _O1 above the outlet 21a of the valve pipe 2a. On the other hand, the inlet 20a of the valve pipe 2a is provided with a pair of stoppers 22a extending upward from the upper end surface _{. 1} , a first end 500a of a first connecting arm 50a of the link means 5a is rotatably supported. When the valve pipe 2a is inserted into the outflow port 61 of the drainage basin 6 and the backflow prevention joint 1a is attached, the stopper 22a comes into contact with the end face of the outflow port 61 and functions as a stopper, which is convenient ( See Figure 12).

The structure for rotatably supporting the valve body _3a and the first end 500a of the first connecting arm 50a at the fulcrum O1 and the fulcrum _P1 is not particularly limited, but in the second embodiment, the fulcrum _P1 has a structure in which a rotation shaft provided at the first end portion 500a of the first connecting arm 50a is rotatably gripped from both sides by bearings formed on each of the pair of stoppers 22a.

In addition, for example, when inserting the valve pipe 2a into the outflow port 61 of the drain basin 6 and attaching the backflow prevention joint 1a to the outer periphery of the valve pipe 2a (Fig. 12), the outer periphery of the valve pipe 2a and the inner wall surface of the outflow port 61 A ring-shaped rubber valve pipe packing 23a is attached to seal the gap between the valve pipe 2a and the valve pipe packing 23a.

<Valve>
In the backflow prevention joint 1a of the second embodiment, vinyl chloride resin is used as the material of the valve body 3a, but the material to be used is not particularly limited, and known materials such as plastics can be mainly used. . The shape of the valve body 3a may be any shape as long as it can abut against the outlet 21a of the valve pipe 2a and completely block the outlet 21a. In the second embodiment, the outlet 21a of the valve pipe 2a Since it has a substantially circular shape with a chipped shape, it has a substantially circular shape with a linearly chipped upper part in a front view in accordance with the shape of the outlet 21a.

As shown in FIGS. 9 and 10, the second connecting arm 51a is rotatably connected to the valve body 3a at a fulcrum _Q1 located at a position different from the fulcrum _O1 at which the valve body 3a rotates in a side view. ing. That is, in the above configuration, the fulcrum _Q1 serves as a point of force or a point of action for opening and closing the valve body 3a. 2 connecting arms 51a can be efficiently converted into opening and closing operations of the valve body 3a.

As shown in FIG. 7, the valve body 3a of the second embodiment has a central split valve body 35a attached to the outlet 21a of the valve pipe 2a at the fulcrum _O1 , and left and right ends of the central split valve body 35a. It is divided into three divided valves including a pair of left and right divided valve bodies 36a which are connected so as to be bendable. Therefore, the normal valve body 3a has a shape in which the pair of left and right split valve bodies 36a are slightly bent toward the rear side with respect to the central split valve body 35a (FIGS. 7 and 8).

Even when the valve body 3a is lightly abutted against the outlet 21a of the valve pipe 2a, the bent shape is maintained. Alternatively, a gap is formed between both ends of the left and right split valve body 36a and the outlet 21 to ensure a smooth flow of forward flow drainage. On the other hand, when backflow water occurs, the central split valve body 35a and the pair of left and right split valve bodies 36a are strongly moved toward the outlet 21a of the valve pipe 2a via the link means 5a by the upward movement of the buoyancy generating section 4a, which will be described later. Since it is drawn and deformed into a planar shape so as to match the shape of the end surface of the outlet 21a (Figs. 10 and 11), the valve body 3a completely blocks the outlet 21a of the valve pipe 2a, effectively preventing backflow of waste water. can be prevented.

Means for imparting buoyancy to the valve body 3a are not particularly limited, but as a configuration for imparting buoyancy, for example, a method of providing a sealed space between the upstream surface and the downstream surface of the valve body and making the valve body a hollow structure. and a method of providing a second buoyant force generator having a specific gravity smaller than that of water on the downstream surface 31 of the valve body 3 .

<Link Means>
In the backflow prevention joint 1a of the second embodiment, the link means 5a is a first connecting arm 50a having a first end 500a rotatably attached to the base of the stopper 22a of the valve pipe _2a at the fulcrum P1. and a second connecting arm 51a rotatably connected to the first connecting arm 50a at a fulcrum _R1 , and having a second end 510a rotatably attached to the valve body 3a at a fulcrum _Q1. consists of That is, one end of the link means 5a is rotatably attached to the inlet 20a of the valve pipe 2 at the fulcrum _P1 , and the other end is rotatably attached to the valve body 3a at the fulcrum _Q1 . there is

The shape and configuration of the first connecting arm 50a and the second connecting arm 51a are not particularly limited as long as they do not interfere with each other's operations. In the second embodiment, the first connecting arm 50a is formed integrally with an extension arm 40a of the buoyancy generating portion 4a, which will be described later, and the second connecting arm 51a is formed at both ends (fulcrums _Q1 , _R1 ) has a rod-like shape in which a shaft hole (rotating shaft) is formed.

In the second embodiment, vinyl chloride resin is used as the material of the first connecting arm 50a and the second connecting arm 51a. materials can be used. In the specification of the present application, "one end", "other end" and "end portion" of the link means 5a strictly mean the end faces of the ends of the first and second connecting arms 50a and 51a. It does not mean "one end", "other end" and "end" of the linking means 5a which may be provided with pivots or bearings.

<Buoyancy generator>
In the backflow prevention joint 1a of the second embodiment, the buoyancy generating portion 4a assists and ensures the opening and closing operation of the valve body 3a so that the valve body 3a does not malfunction in normal and abnormal conditions. 5a is non-rotatably attached to the first connecting arm 50a. Further, in the second embodiment, the force generated by the upward and downward movement of the buoyancy generating portion 4a is increased and transmitted to the valve body 3a via the first connecting arm 50a and the second connecting arm 51a. , the buoyancy generator 4a is attached to the first connecting arm 50a via a thick block-shaped extension arm 40a.

The buoyancy generator 4a may have a specific gravity smaller than that of water so as to generate buoyancy against backflow water, and its shape, structure, material, and the like are not particularly limited. In the second embodiment, the buoyancy generator 4a is made of a hollow cylindrical body made of vinyl chloride resin because it has low resistance to backflow water and is easy to operate manually. In addition, the buoyancy generator 4a is arranged at the fulcrum _O1 of the valve pipe 2a that supports the valve body 3a in order to ensure that the valve body 3a opens the outlet 21a of the valve pipe 2a during normal operation. The weights of the buoyancy generating portion 4a and the extension arm 40a are set so that the moment acting in the direction of opening the valve body 3a due to the weight of the valve body 4a is greater than the moment acting in the direction of closing the valve body 3a due to the weight of the valve body 3a. there is

FIG. 12 shows a cross-sectional view of the drain basin 6 showing the manner in which the backflow prevention joint 1a shown in FIG.

The drainage basin 6 shown in FIG. 12 is a partially enlarged lower portion of a general drainage basin 6 similar to the first embodiment, and has an inlet 60, an outlet 61, and an inlet 60. and an inverted section 62 connected to the outlet port 61, and the upper side of the inverted section 62 has an opening 63 for connecting a riser pipe (not shown) having an inspection port. Also, in the second embodiment, the drainage basin 6 is entirely made of vinyl chloride resin, but it may be made of other known plastic resin, concrete material, or a combination of plastic resin and concrete material.

In the backflow prevention joint 1a of the second embodiment, as shown in FIGS. 8 to 11, the buoyancy generating portion 4a is arranged upstream of the inlet _20a of the valve pipe 2a with respect to the fulcrum O1 at which the valve body 3a rotates. be done. Therefore, in the backflow prevention joint 1a of the second embodiment, the working space for the buoyancy generating portion 4a must be provided upstream of the valve body 3a or upstream of the inlet 20a of the valve pipe 2a. It is suitable for attachment to the outlet 61 side of a drainage system such as the basin 6 as shown.

In the specification of the present application, the expression that the buoyant force generating portion 4a is arranged upstream of the fulcrum _O1 or upstream of the inlet 20a of the valve pipe 2a at which the valve body 3a rotates means that the buoyant force generating portion 4a In the raised and lowered positions, the "center" that generates the buoyancy is upstream of the vertical plane passing through the rotation axis of the fulcrum _O1 at which the valve body 3a rotates, or from the opening surface of the inlet 20a of the valve pipe 2a. It means an aspect arranged on the upstream side. For this reason, in the second embodiment, the link means 5a connected to the buoyancy generating portion 4a is also arranged at least upstream of the fulcrum O1 around which the valve body _3a rotates.

<Operation Mode of Buoyancy Generating Part and Valve>
As shown in FIGS. 8 and 9, under normal conditions, when the liquid level near the backflow prevention joint 1a drops, the buoyancy generator 4a also descends due to its own weight as the liquid level drops. Since the first connecting means 50a is connected to the valve pipe 2a at the fulcrum _P1 , the downward movement of the buoyancy generating portion _4a is as shown in FIGS. Rotate clockwise. Therefore, the clockwise rotational movement of the first connecting means 50a about the fulcrum _P1 causes the second connecting arm 51a to move from the upstream side to the downstream side via the fulcrum _R1 , resulting in the second The above movement of the connecting arm 51a rotates the valve body 3a through the fulcrum _Q1 clockwise around the fulcrum _O1 in FIGS. .

As shown in FIGS. 10 and 11, when backflow water occurs in the vicinity of the backflow prevention joint 1a and the liquid level rises, the buoyancy generating portion 4a also rises as the liquid level rises. Since the first connecting means 50a is connected to the valve pipe 2a at the fulcrum _P1 , the downward movement of the buoyancy generating portion _4a is as shown in FIGS. Rotate counterclockwise. Therefore, the counterclockwise rotational movement of the first connecting means 50a about the fulcrum _P1 causes the second connecting arm 51a to move from the downstream side to the upstream side via the fulcrum _R1 . The movement of the connecting arm 51a rotates the valve body 3a through the fulcrum _Q1 counterclockwise around the fulcrum _O1 in FIGS. move.

As described above, in the backflow prevention joint 1a of the second embodiment, in order to assist the opening/closing operation of the valve body 3a, the valve body 3a rotates the link means 5a connected to the valve body 3a at the fulcrum _Q1 . Since the valve pipe _2a is connected to the valve pipe 2a at the fulcrum _P1 at a position different from the fulcrum O1 where the be able to. Further, in the backflow prevention joint 1a of the second embodiment, for example, by adjusting the distance between the fulcrum O1 and the fulcrum _Q1 in the valve body _3a and the length of the extension arm 40a of the buoyancy generation section 4a, the buoyancy generation section The force generated by the upward and downward movement of 4a can be converted into force of desired magnitude and easily transmitted to valve body 3a so as to assist the opening and closing operation.

Therefore, in the backflow prevention joint 1a of the second embodiment, the valve body 3a is positively opened by the self-weight of the buoyancy generating part 4a in normal times to ensure a smooth flow of waste water in the forward flow. The valve body 3a is positively closed by the buoyancy of the buoyancy generator 4a, so that the reverse flow of waste water can be blocked reliably.

As described above, in the backflow prevention joints 1 and 1a of the first and second embodiments, the buoyancy generators 4 and 4a provided separately from the valve bodies 3 and 3a of the check valves reduce the liquid level of the wastewater flowing backward. rises and falls depending on the height of the Between the valve pipes 2, 2a and the valve bodies 3, 3a, the valve bodies 3, 3a rotate so as to close the outlets 21, 21a of the valve pipes 2, 2a as the buoyancy generating parts 4, 4a rise. In addition, link means 5, 5a are connected so that the valve bodies 3, 3a rotate to open the outlets 21, 21a of the valve pipes 2, 2a as the buoyancy generating portions 4, 4a descend.

For this reason, even in a situation where a large amount of rainwater flows back at once and flows around to the opening side (upstream side) of the valve bodies 3, 3a, the buoyancy generating portions 4, 4a that have risen due to the backflow of water flow through the link means 5, 5a. Since the valve bodies 3 and 3a are reliably actuated in the direction of closing the valve bodies 3 and 3a, it is possible to reliably prevent backflow water from flowing further upstream. In normal times, the weight of the buoyancy generators 4 and 4a exerts a moment in the direction of opening the valve bodies 3 and 3a at the fulcrums O and _O1 of the valve pipes 2 and 2a that support the valve bodies 3 and 3a. It is possible to ensure a smooth forward flow of waste water without being obstructed by the valve bodies 3 and 3a.

Reference Signs List 1, 1a Backflow prevention joint 2, 2a Valve tube 20, 20a Inlet 21, 21a Outlet 22 Support arm 22a Stopper 23, 23a Valve pipe packing 24, 24a Circumferential groove 3, 3a Valve element 30 Upstream surface 31.....Downstream surface 32...Valve packing 33...Fitting groove 34...Guide arm 35a... Central split valve body 36a Left and right split valve bodies 4, 4a Buoyancy generators 40, 40a Extension arms 5, 5a Link means 50, 50a First connecting arm 500, 500a First end 51, 51a Second connecting arm 510, 510a Second end 511, 512 Sub-arm 6 Drain 60 Inlet 61 Outlet 62 Invert section 63... Openings O, _O1 , P, _P1 , Q, _Q1 , R, _R1 ... Fulcrum

Claims (13)

a valve tube having an inlet and an outlet;
a valve body rotatably attached to the valve tube so as to open and close an outlet of the valve tube;
link means having one end rotatably attached to the valve tube and the other end rotatably attached to the valve body; A backflow prevention joint comprising a buoyancy generating part that rises and falls according to height,
The link means rotates the valve body so as to close the outlet of the valve tube as the buoyancy generating section rises, and the valve body opens the outlet of the valve tube as the buoyancy generating section descends. A backflow prevention joint characterized in that it is rotated in such a way as to 2. The backflow prevention according to claim 1, wherein the one end of the link means is rotatably attached to the valve pipe at a fulcrum at a position different from the fulcrum at which the valve body rotates. fittings. Said link means comprises a first connecting arm having said one end and a second connecting arm pivotally connected to said first connecting arm and having said other end. The backflow prevention joint according to claim 1 or 2, characterized in that The valve body includes a guide arm extending in a direction different from the direction in which the valve body extends across a fulcrum at which the valve body rotates, and the second connecting arm is connected to the guide arm. 4. The backflow prevention joint according to claim 3, wherein the joint is rotatably connected. 5. The backflow prevention joint according to claim 4, wherein the buoyancy generator has an extension arm, and the buoyancy generator is attached to the second connecting arm via the extension arm. 6. The backflow prevention joint according to claim 5, wherein the buoyancy generating portion is arranged downstream of a fulcrum at which the valve body rotates. 4. The backflow prevention joint according to claim 3, wherein the second connecting arm is rotatably connected to the valve body at a fulcrum at a position different from the fulcrum at which the valve body rotates. 8. The backflow prevention joint according to claim 7, wherein the buoyancy generator has an extension arm, and the buoyancy generator is attached to the first connecting arm via the extension arm. 9. The backflow prevention joint according to claim 8, wherein the buoyancy generating portion is arranged upstream of a fulcrum at which the valve body rotates. The backflow prevention joint according to any one of claims 1 to 9, wherein the buoyancy generating portion has a specific gravity smaller than that of water. 11. Any one of claims 1 to 10, wherein a moment generated by the weight of the buoyancy generating portion at a fulcrum of the valve pipe supporting the valve body is larger than a moment generated by the weight of the valve body. The backflow prevention joint described in the paragraph. 12. The backflow prevention according to any one of claims 1 to 11, wherein the outlet of the valve pipe is inclined from the downstream side to the upstream side as the end face of the outlet goes from the top to the bottom. fittings. A drainage facility having an inlet or an outlet, wherein the backflow prevention joint according to any one of claims 1 to 12 is provided at the inlet or the outlet.

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