JP2005200845A - Back flow check device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a back flow check device capable of preventing the back flow in piping in case of emergency such as a flood or the like by suppressing the lowering of air-tightness in an inlet by a check valve. <P>SOLUTION: When waste liquid flows backward into a container 2 from a drain outlet 6 through an exhausting pipe 7, the liquid level of reservoir liquid in the container 2 rises to begin floating the check valve 8 by buoyancy of the reservoir liquid. With the floating, an oscillation arm 9 is oscillated toward a closing position side from an opening position of the check valve 8 with an oscillation shaft 10 as the center. Then, when the liquid level in the container 2 further rises, the check valve 8 receives the buoyancy to arrive at the closing position furthermore oscillated by the oscillation arm 9 with the oscillation shaft 10 as the center, the inlet 4 is closed by the check valve 8, and the back flow of the waste liquid toward the exhausting pipe 22 located on an upstream side from the inlet 4 of the container 2 and an indoor drain outlet 21 is prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is disposed in an intermediate portion of a drain pipe for discharging waste liquid from an indoor to a waste water treatment facility such as a sewer pipe. The present invention relates to a backflow prevention device for preventing drainage from flowing back.

  Generally, domestic wastewater from kitchens, toilets, baths, toilets, and other water is discharged through a domestic drainage pipe to a wastewater treatment facility such as a sewer pipe. In addition, rainwater at the time of rain is discharged through a rainwater pipe into a gutter buried along the road and discharged to a river, or discharged into a wastewater treatment facility such as a sewer pipe together with domestic wastewater. Normally, these wastewater treatment facilities are functioning without being disturbed, but once a heavy rain occurs, in a city area where the ground surface is paved, a large amount of rainwater flows into the ditches, and the rainwater overflows or rivers The amount of water will rise rapidly, causing flooding.

  In such a flood, in addition to drainage from the ditches, flooded ground surface water also flows into the sewer pipes through manholes, etc., so a reverse flow occurs from the sewer pipes to the domestic drainage pipes, and the drainage from the indoor drainage outlets. The eruption sometimes flooded the interior. Therefore, in order to prevent such inundation, it is conceivable to provide a backflow prevention device for preventing the backflow of the drainage in the domestic drainage pipe connected to the sewer pipe. Various proposals have been made regarding backflow prevention devices in pipes. For example, Japanese Utility Model Publication No. 6-67588 discloses a drainage backflow prevention device.

The drainage backflow prevention device described in the publication is arranged in the drainage basin, and an elastic floating body having a diameter larger than the opening diameter of the drainage pipe for allowing the drainage to flow into the drainage basin, As the water level rises and falls, the opening of the drain pipe is opened or closed by raising and lowering the float. Here, in the drainage backflow prevention device, a cage-like stationary device capable of accommodating the float is disposed in the opening of the drainage pipe, and the float is always positioned below the opening of the drainage pipe by the placement device. Structure is adopted.
Japanese Utility Model Publication No. 6-67588

  However, according to the drainage backflow prevention device described above, the float that closes the drainage pipe to prevent the backflow to the drainage pipe functions as a check valve. Because it is always located, it will always be exposed to the drainage that flows into the drain. For this reason, the float which is a check valve is liable to adhere to foreign matters contained in the drainage, and there is a concern that the sealing performance when the drainage pipe is blocked by such deposits is deteriorated.

  In addition, since the float is formed of an elastic body, depending on the material, it may continue to be exposed to drainage, which may cause deterioration and decrease in elasticity, thereby reducing the sealing performance when closing the drain pipe. Conceivable.

  The present invention has been made to solve the above-described problems, and it is possible to prevent a back flow in a pipe in an emergency such as a flood by suppressing a decrease in the sealing performance of an inlet by a check valve. The object is to provide a prevention device.

  In order to achieve this object, the backflow prevention device according to claim 1 prevents backflow in the pipe, and includes a container body, a discharge port provided at the bottom of the container body, and a position above the discharge port. An inflow port provided at a side portion of the container body to be separated from the container body, and disposed in the container body in order to close the inflow port, and when the stored liquid is stored at the bottom of the container body, from the stored liquid A check valve that receives buoyancy greater than its own weight, an open position where the check valve is spaced from the inlet, and a closed position where the check valve closes the inlet located above the open position. A swing support that supports the check valve in a swingable manner and supports the check valve at a position that is out of the flow path from the inlet to the discharge port when the check valve is in the open position. And a member.

  According to the backflow prevention device of the first aspect, if the inflow port is open, the drainage liquid from the indoor flows into the container body from the inflow port through the drainage pipe, flows down to the bottom of the container body, and is discharged. It is discharged out of the container body from the outlet. On the other hand, when the drainage flows backward from the discharge port into the container body, the backflowed drainage liquid is stored at the bottom of the container body and raises the liquid level of the stored liquid. As the liquid level rises in the container, the check valve receives buoyancy from the stored liquid and is pushed upward, and is swung from the open position to the closed position via the swing support member.

  When the liquid level of the stored liquid further rises due to the back flow into the container, the check valve is further swung to reach the closed position and close the inflow port. Occlusion of the inflow port by the check valve prevents the backflow of drainage from the container body to the inflow port. After that, the backflow of drainage into the container body is stopped, the stored liquid in the container body is discharged from the discharge port, and when the liquid level of the stored liquid is lowered and the buoyancy acting on the check valve is reduced, the check valve is It is swung from the closed position to the open position via the swing support member, and the inflow port is opened again.

  The backflow prevention device according to claim 2 is the backflow prevention device according to claim 1, wherein the swing support member includes a swing shaft provided at a position above the inflow port in the container body, and the swing shaft. The check is pivotally supported so as to extend from the swing shaft toward the bottom side of the container body in the direction from the inflow port, and at the leading end of the extending direction in the open position. And a swing arm to which the valve is attached.

  According to the backflow prevention device according to the second aspect, in addition to acting in the same manner as the backflow prevention device according to the first aspect, when a backflow occurs to the container body through the discharge port, the liquid level of the stored liquid in the container body rises. The check valve is pushed upward in response to the buoyancy caused by the stored liquid. By this pushing up, the check valve is swung around the swinging shaft with the swinging arm and moved toward the inlet.

  The backflow prevention device according to claim 3 is the backflow prevention device according to claim 1 or 2, wherein the container body is provided with a space in which stored liquid can be stored above the upper edge of the inlet. Yes.

  The backflow prevention device according to a fourth aspect is the backflow prevention device according to any one of the first to third aspects, wherein the inflow port has a substantially tapered valve seat surface on the entire circumference of the opening edge of the inflow port. The check valve includes a substantially weight-shaped seating surface that can come into surface contact with the valve seat surface.

  The backflow prevention device according to claim 5 is the backflow prevention device according to claim 4, wherein an elastically compressible deformation member is laid on the seating surface of the check valve.

  According to the backflow prevention device according to claim 1, for example, a container body is installed in an intermediate portion of a drainage pipe that discharges drainage to a wastewater treatment facility such as a sewer pipe, and the upstream side of the drainage pipe is used as an inlet. If the downstream side of the drain pipe is connected to the discharge port, drainage can be prevented from flowing backward from the waste water treatment facility such as a sewer pipe to the upstream side of the container body. Therefore, for example, there is an effect that indoor inundation caused by backflow from a wastewater treatment facility such as a sewer pipe during flooding can be prevented.

  Further, when the check valve is supported at the open position by the swing support member, that is, when the liquid level of the liquid stored in the bottom of the container body is below the check valve, the swing support member Therefore, it is supported at a position outside the flow path from the inlet to the outlet in the container. Therefore, the check valve in the open position has an effect of reducing the chance of being directly exposed to the flow of drainage from the inlet to the outlet and suppressing the check valve from being contaminated.

  In other words, it is possible to prevent foreign matter mixed in the drainage flowing in from the inlet from adhering to the check valve or entanglement of foreign matter mixed in the drainage into the check valve. It is possible to suppress a decrease in the sealing degree at the time of closing the inlet due to the adhering matter, and it is possible to prevent the backflow by blocking the inlet with a check valve more reliably.

  In addition, since the check valve itself receives buoyancy and moves up and down according to the liquid level, there is no need to separately provide a float to operate the check valve, reducing the number of parts as a whole device and simplifying the structure Therefore, there is an effect that a failure is hardly caused. Furthermore, the check valve opens or closes the inlet by the buoyancy of the drainage according to the rise in the liquid level of the drainage that flows back into the container through the outlet, so that the electrical valve that detects the backflow from the outlet There is no need to provide a separate sensor or the like, and the manufacturing cost and installation cost can be reduced. In addition, there is no need to separately provide a power source for opening or closing the check valve. For example, there is an effect that the power cost is unnecessary.

  According to the backflow prevention device of the second aspect, in addition to the effect of the backflow prevention device of the first aspect, the swing shaft of the swing support member is pivotally supported by the container body at a position above the inlet. Therefore, it is possible to prevent the swinging shaft, which is the movable part of the swinging arm, from being exposed to the flow of drainage from the inlet to the outlet. For this reason, foreign matters mixed in the flow from the inlet to the outlet are unlikely to be entangled around the swinging shaft, so that it is difficult to cause a check valve malfunction due to the entanglement of foreign matters in an emergency such as a flood.

  In addition, the swing arm to which the check valve in the open position is attached is extended from the swing shaft toward the bottom side of the container body, and the extending direction is inclined toward the inflow port. When receiving the buoyancy acting on the check valve, there is an effect that it becomes easier to swing to the inlet.

  According to the backflow prevention device according to claim 3, in addition to the effect of the backflow prevention device according to claim 1 or 2, the liquid level of the stored liquid in the container body rises and the check valve receives buoyancy. After closing the inlet, if the drainage continues to flow back into the container from the outlet, the drainage will enter the space of the container provided above the upper edge of the inlet closed by the check valve. Stored. As a result, since the check valve is sunk in the stored liquid in the container body, the check valve is strongly pressed against the inflow port by the water pressure accompanying the sunk, and there is an effect that the sealing performance when the inflow port is closed can be improved.

  According to the backflow prevention device of the fourth aspect, in addition to the effect of the backflow prevention device according to any one of the first to third aspects, when the inflow port is blocked by the check valve, Since the planar seating surface is in surface contact with the substantially tapered valve seat surface of the inlet, there is an effect that the sealing performance of the inlet at the time of closing can be further improved.

  According to the backflow prevention device of the fifth aspect, in addition to the effect of the backflow prevention device of the fourth aspect, when the inlet is closed by the check valve, the seating surface of the check valve and the valve seat of the inlet Since the sealing member which can be elastically compressed and deformed is interposed between the surfaces, there is an effect that the sealing property of the inlet port by the check valve can be further improved.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view showing the internal structure of a backflow prevention unit 1 which is an embodiment of the backflow prevention device of the present invention. As shown in FIG. 1, the backflow prevention unit 1 is comprised as one unit, and is provided with the container body 2 formed in the hollow cylindrical body.

  The container body 2 is formed with a space capable of storing the drained liquid flowing backward therein, and an upper end portion thereof is opened upward. A flange 2a is extended from the peripheral edge of the upper end of the container body 2 toward the substantially horizontal outside, and the canopy 3 is detachably fastened through the flange 2a. The top cover 3 closes the upper end opening of the container body 2. In addition, on the side surface of the container body 2, an inflow port 4 through which drainage liquid flows into the container body 2 is provided.

  The inflow port 4 is an opening formed through the side surface of the container body 2, and is provided so that the lower end of the opening edge is located at a predetermined height from the bottom surface of the container body 2. A hollow tubular inflow pipe 5 extends from the opening edge of the inflow port 4 toward the outside of the container body 2 (left side in FIG. 1). The inflow pipe 5 communicates with the inflow port 4. The inflow pipe 5 is for connecting a drain pipe connected to an indoor drain port provided around a water such as a kitchen, a washroom, a bathroom, and a toilet in a building to the inlet 4 of the container body 2. (See FIG. 2).

  The drain pipe connected to the indoor drain port of the building has a slope that is inclined downward from the upstream side to the downstream side when buried in the ground in order to promote the drainage of the drainage. For this reason, the inflow pipe 5 is attached to the outer peripheral surface of the container body 2 in a state of being slightly inclined upward from the base side with the container body 2 toward the outside (left side in FIG. 1). In addition, a discharge port 6 for discharging the drainage liquid from the container body 2 is provided at the bottom of the container body 2.

  Specifically, the discharge port 6 is an opening formed through substantially the center of the bottom surface of the container body 2, and a hollow tubular discharge pipe 7 extends from the opening edge toward the lower outside of the container body 2. ing. The discharge pipe 7 communicates with the discharge port 6 and connects a drain pipe connected to a waste water treatment facility such as a sewer pipe to the discharge port 6 of the container body 2. The bottom surface of the container body 2 provided with the discharge port 6 is inclined downward toward the discharge port 6, and the drainage liquid remaining on the bottom surface of the container body 2 is easy to flow down to the drain port 6. A check valve 8 that closes the inflow port 4 is disposed above the drain port 6.

  The check valve 8 is disposed above the drain port 6, that is, at a position spaced a predetermined distance from the substantially central portion of the bottom surface of the container body 2. The check valve 8 is formed in a hollow shape so as to reduce the weight so that when the drainage liquid is stored in the container body 2, the check valve 8 receives the buoyancy from the drainage and floats in the drainage. . Therefore, the check valve 8 can float in the container body 2 by receiving buoyancy larger than its own weight from the drainage. The check valve 8 that can be lifted by receiving buoyancy in this way is attached to one end side (lower end side) in the longitudinal direction of the long bar-like swing arm 9 and is suspended in the container body 2.

  The swing arm 9 supports the check valve 8 as described above, and the swing shaft 10 is provided through the other end (upper end) in the longitudinal direction. The swinging shaft 10 supports the swinging arm 9 so as to be swingable, and its axial direction is oriented in a direction substantially equal to the direction substantially perpendicular to the paper surface of FIG. Further, both axial ends of the swing shaft 10 are constructed on the side wall surface of the container body 2.

  By the pivotal support of the swing shaft 10, the swing arm 9 has an open position in which the check valve 8 is separated from both the inlet 4 and the outlet 6 and is above the outlet 6 (FIGS. 1 and 3 ( between the position shown in a) and the closed position (position shown in FIG. 3B) where the check valve 8 is inserted into the opening of the inlet 4 to close the inlet 4. The stop valve 8 can be swingably supported.

  As described above, the check valve 8 in the open position is positioned above the bottom surface of the container body 2 by the swing arm 9 and the swing shaft 10, but when the check valve 8 is in the open position, the check valve 8 The stop valve 8 is positioned outside the region of the flow path 11 through which the drainage flows from the inlet 4 toward the outlet 6. As a result, the check valve 8 is not directly exposed to the drainage flowing through the flow path 11 unless a large amount of drainage flows from the inlet 4 vigorously, and foreign matter contained in the drainage is not checked. Adhering to or tangling with the valve 8 can be greatly suppressed.

  Further, when the check arm 8 is supported in the open position, the swing arm 9 has a virtual center line L (1 in FIG. 1) connecting the axis of the swing shaft 10 and the attachment portion of the check valve 8. (Dotted line) extends substantially vertically downward, but strictly speaking, it is pushed by the tip of the stopper member 12 protruding from the side surface facing the inflow port 4 of the container body 2, as described above. The imaginary center line L is inclined slightly from the inlet 4 side as it goes from the axial center of the swing shaft 10 to the attachment portion of the check valve 8. As a result, when the check valve 8 receives buoyancy from the drainage, the check valve 8 easily swings to the closed position on the inlet 4 side via the swing arm 9 and the swing shaft 10.

  Further, the check valve 8 has a substantially conical seating surface 8a formed on the front end side (left side in FIG. 1) in the swing direction when the check arm 8 is swung from the open position side to the closed position side by the swing arm 9. The seating surface 8a is provided with a substantially sheet-like sealing member 13 that can be elastically compressed and deformed. On the other hand, the inflow port 4 is provided with a valve seat member 14 for receiving the check valve 8 described above. The valve seat member 14 includes a valve seat surface 14 a provided over the entire circumference of the opening edge of the inlet 4. The valve seat surface 14 a is formed in a substantially tapered shape whose inner diameter gradually decreases toward the outside of the container body 2, and can come into surface contact with the seating surface 8 a of the check valve 8.

  FIG. 2 is a diagram illustrating an installation example of the backflow prevention unit 1. As shown in FIG. 2, the backflow prevention unit 1 is embedded in the ground. Here, an indoor drainage port 21 for discharging wastewater such as domestic wastewater generated from the surroundings of kitchens, washrooms, bathrooms, toilets, and the like is provided in the floor of the building 20. A drain pipe 22 is connected to the drain port 21.

  The drain pipe 22 is buried in the ground, and is in a state of being slightly inclined downward from the upstream side toward the downstream side. The inflow pipe 5 of the backflow prevention unit 1 is connected to the downstream end of the drainage pipe 22, and the drainage pipe 22 is also connected to the rainwater pipe 23 at a position upstream of the backflow prevention unit 1. Yes. For this reason, rainwater also flows into the backflow prevention unit 1 together with wastewater such as domestic wastewater.

  The upstream end of the drain pipe 24 is connected to the discharge pipe 7 of the backflow prevention unit 1, and the drain pipe 24 is also embedded in the ground with a slight downward inclination from the upstream side to the downstream side. The downstream end of the drain pipe 24 is connected to the sewer pipe 25. As a result, the drainage or rainwater flowing into the backflow prevention unit 1 is discharged to the sewer pipe 25 through the drain pipe 24 and transferred to a waste water treatment facility having the sewer pipe 25 as a pipe line. The rainwater on the ground surface is drained to the river and the sewer pipe 25 through the drainage groove 26.

  Next, the operation of the backflow prevention unit 1 configured as above will be described with reference to FIGS. Here, FIG. 3A is a longitudinal sectional view of the check valve 8 with the check valve 8 in the open position, and FIG. 3B shows the check valve unit 1 with the check valve 8 in the closed position. FIG.

  When the backflow prevention unit 1 is embedded as shown in FIG. 2 as described above, the drainage such as domestic wastewater generated in the building 20 is normally discharged from the indoor drain 21 and the rainwater is discharged from the rainwater pipe 23 and the drainage pipe 22 respectively. And flows into the backflow prevention unit 1 through the inflow pipe 5. As shown in FIG. 3A, the drainage and rainwater flowing into the inflow pipe 5 flows through the flow path 11 from the inlet 4 toward the outlet 6 along the bottom surface of the container body 2. It is discharged to the sewer pipe 25 through the discharge pipe 7 and the drain pipe 24.

  On the other hand, when the water level outside the building 20 or the drainage liquid level in the sewer pipe 25 rises due to the occurrence of a flood or the like, a reverse flow of the drainage flowing in the sewer pipe 25 occurs, and this backflow drainage liquid Flows backward from the discharge port 6 into the container body 2 through the drain pipe 24 and the discharge pipe 7. As a result of this backflow, drainage is stored at the bottom of the container body 2, the level of the stored liquid rises, and the stored liquid reaches the check valve 8 in the open position (position shown in FIG. 3A). After that, when the liquid level of the stored liquid further rises, the check valve 8 starts to rise due to the buoyancy caused by the stored liquid.

  As this floats, the swing arm 9 moves from the open position of the check valve 8 toward the closed position (position shown in FIG. 3B) around the swing shaft 10, that is, FIG. ) In the clockwise direction. Thereafter, when the liquid level in the container body 2 further rises, the check valve 8 receives buoyancy and is further swung around the swing shaft 10 with the swing arm 9 to reach the closed position. The seating surface 8a is in surface contact with the valve seat surface 14a of the valve seat member 14 with the sealing member 13 interposed therebetween. As a result, the inflow port 4 is blocked by the check valve 8, and the backflow of the drainage toward the drain pipe 22 and the indoor drain port 21 located upstream from the inflow port 4 of the container body 2 is prevented.

  After that, when the liquid level in the container body 2 further rises from the position of the inlet 4 and the check valve 8 and the drainage liquid is stored on the upper side of the container body 2, the check is put into the drainage liquid. Since the valve 8 sinks, the hydraulic pressure of the drainage acts in the direction of pressing the check valve 8 toward the inlet 4, the seating surface 8 a is pressed against the valve seat surface 14 a, and the inlet 4 is in the closed state. The sealing performance is further improved.

  After that, when the outdoor water level and the liquid level in the sewer pipe 25 are lowered and the backflow of the drainage from the sewer pipe 25 toward the backflow prevention unit 1 is stopped, the drainage stored in the container body 2 is also drained. It is gradually discharged from the outlet 6 through the discharge pipe 7 and the drain pipe 24. When the liquid level of the stored liquid in the container body 2 is lowered with this discharge and the buoyancy acting on the check valve 8 is weakened, the check valve 8 is centered on the swing shaft 10 via the swing arm 9. It is swung from the closed position toward the open position, that is, counterclockwise in FIG.

  By this swinging, the inlet 4 is opened, so that the drainage from the indoor drain 21 and the drain pipe 22 can flow into the container body 2. When the liquid level of the stored liquid in the container body 2 is lowered below the check valve 8, the swing of the swing arm 8 is restricted by the tip of the stopper member 12, and the check valve 8 is positioned at the open position. Thus, the backflow prevention unit 1 returns to the original normal state shown in FIG.

  The present invention has been described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be easily made without departing from the spirit of the present invention. It can be guessed.

  For example, in the present embodiment, the discharge port 6 is provided at substantially the center of the bottom surface of the container body 2, but the position of the drain port is not necessarily limited to this, and the position of the container body 2 is lower than the inflow port 4. Any other position may be used as long as it is the bottom. Further, in this embodiment, the swing arm 9 is pivotably supported via the swing shaft 10 penetrating the swing arm 9, but the swing arm 9 is pivotably supported. For example, the swing arm and the swing shaft may be integrated, and the swing shaft may be swingably mounted on the container body.

  Moreover, although the present Example demonstrated using the backflow prevention unit 1 which unitized the backflow prevention apparatus of this invention, embodiment of this invention is not necessarily limited to what was unitized, for example, The members in the backflow prevention unit 1 may be assembled on site.

It is a longitudinal cross-sectional view which shows the internal structure of the backflow prevention unit which is one Example of this invention. It is a figure which shows the example of installation of a backflow prevention unit. (A) is a longitudinal cross-sectional view of the backflow prevention unit with the check valve in the open position, and (b) is a longitudinal cross-sectional view of the backflow prevention unit with the check valve in the closed position.

Explanation of symbols

1 Backflow prevention unit (backflow prevention device)
2 Container body (part of the container body)
3 Canopy (part of the container)
4 inflow port 6 discharge port 8 check valve 8a seating surface 9 swing arm (swing arm, part of swing support member)
10 Oscillation shaft (Oscillation shaft, part of the oscillation support member)
11 Flow path 12 Stopper member 13 Sealing member 14 Valve seat member 14a Valve seat surface

Claims (5)

In the backflow prevention device that prevents backflow in the piping,
A container body;
An outlet provided at the bottom of the container body;
An inlet provided in a side portion of the container body spaced apart from the discharge port;
A check valve that is disposed within the container body to close the inlet and receives buoyancy greater than its own weight from the stored liquid when the stored liquid is stored at the bottom of the container body;
The check valve is swingably supported between an open position where the check valve is separated from the inlet and a closed position where the check valve closes the inlet located above the open position. And a swing support member that supports the check valve at a position deviated from the flow path from the inlet to the discharge port when the check valve is in the open position. Backflow prevention device. The swing support member is swingably supported by a swing shaft provided at a position above the inflow port in the container body, and swingable by the swing shaft, and from the swing shaft to the bottom of the container body And a swing arm that extends in a direction from the inflow port and is attached to the check valve in the open position at a distal end portion in the extending direction. Item 2. A backflow prevention device according to item 1. 3. The backflow prevention device according to claim 1, wherein the container body is provided with a space in which stored liquid can be stored above the upper edge of the inflow port. The inflow port includes a substantially tapered valve seat surface on the entire periphery of the opening edge of the inflow port, and the check valve has a substantially weight surface seating surface that can come into surface contact with the valve seat surface. The backflow prevention device according to any one of claims 1 to 3, further comprising: The backflow prevention device according to claim 4, wherein a sealing member elastically compressible and deformable is laid on the seating surface of the check valve.

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