JP2022018078A - Backflow prevention basin - Google Patents

Abstract

To provide a backflow prevention basin that prevents intrusion of drainage flowing back through a drainage pipeline to an upstream side, while suppressing occurrence of drainage clogging due to filth even when an amount of the drainage is small.SOLUTION: A backflow prevention basin 10 is provided in the drainage pipeline connecting an indoor drainage facility and a sewer pipe. The backflow prevention basin 10 comprises: a catch basin body 11; an inflow pipe part 12 and an outflow pipe part 13 for drainage provided on a side wall of the catch basin body 11; and a backflow prevention valve 14 provided in the catch basin body 11. The backflow prevention valve 14 has a valve body 141 configured to be able to close a downstream opening 12b of the inflow pipe part 12. A downstream side pipe bottom of the inflow pipe part 12 is located below an upstream side pipe bottom of the inflow pipe part 12.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a backflow prevention mass provided in a drainage pipe connecting an indoor drainage facility such as a toilet and a sewer pipe to prevent intrusion of drainage flowing back through the drainage pipe to the upstream side.

Generally, drainage discharged from an indoor drainage facility such as a toilet is discharged to a sewer main (hereinafter, simply referred to as a sewer pipe) via a drainage pipe buried in the ground. In addition, in order to remove and inspect filth such as dust in the drainage pipe, a drainage mass is usually installed on the upstream side of the connection point with the sewer pipe in the drainage pipe.

However, when a large amount of rainwater flows into the sewer pipe in a short time due to a typhoon or the like, the drainage that overflows beyond the drainage capacity of the sewer pipe flows back through the drainage mass and is connected to the drainage pipe. There is a problem that the backflow drainage is ejected into the building from the indoor drainage facility, or the sealed water is ejected into the building by the air pumped by the drainage.

On the other hand, in order to prevent the drainage flowing back from the sewer pipe from flowing out from the indoor drainage facility through the drainage mass, Patent Document 1 describes the backflow in which a check valve is attached to the inflow side opening inside the drainage mass. The prevention mass is disclosed.

In the check flow prevention mass described in Patent Document 1, the valve body of the check flow prevention valve is rotatably attached to the inflow side opening so as to incline from the upstream side to the downstream side as the valve body of the check flow prevention valve goes from the upper part to the lower part. Therefore, the valve body of the check valve usually closes the inflow side opening by its own weight. As a result, when the drainage flows from the indoor drainage facility to the drainage mass, the valve body is lifted by the flow of the drainage to open the inflow side opening. On the other hand, when the drainage flows back from the sewer pipe to the drainage mass, the valve body closes the inflow side opening by its own weight and the flow of the drainage, so that the drainage flows back to the drainage pipeline on the upstream side through the drainage mass. Can be prevented.

Japanese Unexamined Patent Publication No. 2010-126888

With the spread of water-saving toilets in recent years, the amount of normal drainage in indoor drainage facilities has decreased significantly. However, in the case of the backflow prevention mass described in Patent Document 1, since the valve body normally blocks the inflow side opening of the drainage mass by its own weight, if the amount of drainage decreases, the valve body becomes difficult to open. There is a problem that dirt such as dust accumulates around the valve body and clogs the flow.

In view of the above, the present disclosure makes it possible to suppress the occurrence of drainage clogging due to filth or the like even when the amount of drainage is small in the backflow prevention mass that prevents the drainage flowing back in the drainage pipe from entering the upstream side. The purpose.

In order to achieve the above object, the first aspect according to the present disclosure is provided in a drainage pipe connecting an indoor drainage facility and a sewage pipe, and intrusion of drainage flowing back through the drainage pipe into the upstream side. It is a backflow prevention mass for preventing the above, and is provided in the drainage mass main body, the inflow pipe portion and the outflow pipe portion of the drainage provided on the side wall of the drainage mass main body, and the inflow pipe portion provided in the drainage mass main body. A check valve having a valve body configured to close the downstream opening is provided, and the downstream pipe bottom of the inflow pipe portion is located below the upstream pipe bottom of the inflow pipe portion to prevent backflow. It is a mass.

According to the first aspect, in the drainage inflow pipe portion provided on the side wall of the drainage mass main body, the downstream side pipe bottom is located below the upstream side pipe bottom. Therefore, when the drainage flows from the upstream side to the downstream side of the inflow pipe portion, the flow velocity of the drainage increases, so that the valve body of the check valve that closes the downstream opening of the inflow pipe portion is easily opened by the flow of the drainage. .. Therefore, even when the amount of drainage is small, it is possible to prevent the backflow prevention mass from being clogged with drainage due to filth or the like.

A second aspect according to the present disclosure is, in the first aspect, the bottom portion of the drainage mass body is a backflow prevention mass located below the bottom of the downstream side pipe portion of the inflow pipe portion.

According to the second aspect, it is possible to avoid a situation in which filth or the like accumulates on the downstream side of the valve body of the check valve in the drainage mass body and hinders the opening of the valve body, so that drainage clogging due to filth or the like occurs. It can be further suppressed.

A third aspect according to the present disclosure is, in the first or second aspect, the height difference between the downstream side pipe bottom and the upstream side pipe bottom in the inflow pipe portion is connected to the inflow pipe portion from the upstream side. It is a backflow prevention mass that is 23% or more of the inner diameter of the pipe to be installed.

According to the third aspect, the flow velocity of the drainage can be sufficiently increased when the drainage flows from the upstream side to the downstream side of the inflow pipe portion. Therefore, since the valve body of the check valve is more easily opened by the flow of drainage, it is possible to further suppress the occurrence of drainage clogging due to filth or the like.

A fourth aspect according to the present disclosure is, in any one of the first to third aspects, the inflow pipe portion includes at least a valve pipe attached to the downstream side from the inside of the drainage mass body, and said. A backflow prevention mass provided with a valve seat surface capable of contacting the valve body on the downstream end surface of the valve tube.

According to the fourth aspect, since the valve pipe opened and closed by the valve body is attached from the inside of the drainage mass body, the valve body can be attached integrally with the valve tube, and the backflow prevention mass can be easily assembled.

A fifth aspect according to the present disclosure is, in any one of the first to fourth aspects, the inflow pipe portion is a first horizontal pipe portion which is arranged on the upstream side and whose bottom is horizontal or substantially horizontal. , A backflow prevention mass including at least an inclined pipe portion arranged on the downstream side of the first horizontal pipe portion and having a pipe bottom inclined downward on the downstream side.

According to the fifth aspect, even when the flow gradient of the pipe connected to the inflow pipe portion of the backflow prevention mass from the upstream side is small, the pipe can be easily connected to the first horizontal pipe portion of the inflow pipe portion. can.

In the sixth aspect according to the present disclosure, in the fifth aspect, the first horizontal pipe portion and the inclined pipe portion are integrally molded, and the inflow pipe portion is inserted into the drainage mass main body and the inflow. A backflow prevention mass provided with a valve seat surface capable of contacting the valve body on the downstream end surface of the pipe portion.

According to the sixth aspect, since the number of components of the backflow prevention mass can be reduced, the backflow prevention mass can be easily assembled.

A seventh aspect according to the present disclosure is, in the fifth or sixth aspect, the inflow pipe portion is arranged on the downstream side of the inclined pipe portion, is connected to the drainage mass main body, and the pipe bottom is horizontal. Alternatively, it is a backflow prevention mass including a second horizontal pipe portion that is substantially horizontal.

According to the seventh aspect, the second horizontal pipe portion of the inflow pipe portion can be easily attached to the side wall of the drainage mass main body.

The eighth aspect according to the present disclosure is any one of the fifth to seventh aspects, in which the extension line of the pipe axis of the first horizontal pipe portion does not intersect with the inner wall surface of the inclined pipe portion. It is a backflow prevention mass that passes through the downstream opening of the inflow pipe portion.

According to the eighth aspect, when the drainage flows from the upstream side to the downstream side of the inflow pipe portion, it is possible to avoid a situation in which the drainage collides with the vicinity of the pipe top of the inclined pipe portion and the flow velocity of the drainage decreases. The body can be easily opened by the flow of drainage.

A ninth aspect according to the present disclosure is, in any one of the first to eighth aspects, the downstream side of the inflow pipe portion is inserted into the inside of the drainage mass main body, and the valve body is drainage-free. Occasionally, the downstream opening of the inflow pipe portion is vertically closed, and a valve seat surface configured to be in contact with the valve body when drainage flows back is provided at the peripheral edge portion of the downstream side opening of the inflow pipe portion. , Backflow prevention mass.

According to the ninth aspect, the configuration of the inflow pipe portion is simplified and the backflow prevention mass can be easily assembled. In addition, it is possible to easily open and close the valve body at the time of drainage, prevent the situation where air is pumped to the upstream side when the backflow of drainage occurs, and suppress the occurrence of water sealing breakage in the drainage pipeline.

A tenth aspect according to the present disclosure is, in the ninth aspect, the valve seat surface is a backflow prevention mass provided in a divergent manner in the downstream direction from the inner peripheral surface to the end surface of the inflow pipe portion. ..

According to the tenth aspect, when the backflow of drainage occurs, the water stopping effect by the valve body can be surely obtained even with a weaker force (water pressure).

According to the present disclosure, it is possible to suppress the occurrence of drainage clogging due to filth or the like even when the amount of drainage is small in the backflow prevention mass that prevents the drainage flowing back in the drainage pipe from entering the upstream side.

FIG. 1 is a diagram showing an example of a drainage pipe line provided with a backflow prevention mass according to an embodiment. FIG. 2 is a vertical cross-sectional view of the backflow prevention mass according to the embodiment. FIG. 3 is a cross-sectional view schematically showing a connection point between the drainage mass main body and the inflow pipe portion in the backflow prevention mass shown in FIG. 2 and its vicinity. FIG. 4 shows the height difference between the bottom of the downstream pipe and the bottom of the upstream pipe in the inflow pipe portion and the height of the bottom of the main body of the drainage mass and the bottom of the downstream pipe of the inflow pipe portion in the backflow prevention mass according to the embodiment. It is sectional drawing which shows the difference. FIG. 5 is a vertical cross-sectional view of the backflow prevention mass according to the modified example.

(Embodiment)
Hereinafter, the backflow prevention mass according to the embodiment of the present disclosure will be described in detail with reference to the drawings. The present disclosure is not limited to the embodiments shown below, and various changes can be made without departing from the technical idea of the present disclosure.

<Example of drainage pipeline configuration>
As shown in FIG. 1, for example, the backflow prevention mass 10 of the present embodiment is provided in a drainage pipe 1 connecting an indoor drainage facility 2 such as a toilet and a sewer pipe (not shown), and backflow flows through the drainage pipe 1. Prevent the intrusion of wastewater to the upstream side. In order to remove and inspect filth such as dust in the drainage pipe 1 between the indoor drainage facility 2 and the backflow prevention mass 10 in the drainage pipe 1, for example, other drainage masses 3A, 3B, 3C. May be provided. The pipe constituting the drainage pipe 1 is, for example, a vinyl chloride pipe VU100 having an inner diameter of 107 mm, and the pipe may be provided with a flow gradient of, for example, about 1/200 toward the downstream side.

<Example of configuration of backflow prevention mass>
As shown in FIGS. 2 and 3, the backflow prevention mass 10 includes the drainage mass main body 11, the drainage inflow pipe portion 12 and the outflow pipe portion 13 provided on the side wall of the drainage mass main body 11, and the inside of the drainage mass main body 11. The check valve 14 provided in the above is provided. The backflow prevention mass 10 may be made of, for example, a synthetic resin such as polyvinyl chloride.

An opening 11a for inserting an adjuster for height adjustment and a lid (not shown) is provided in the upper part of the drainage mass main body 11. The opening 11a has, for example, a circular shape having a diameter of about 50 to 300 mm. By inserting an adjuster or a lid into the opening 11a, the backflow prevention mass 10 can be faced to the ground surface for inspection and maintenance of the backflow prevention mass 10.

An opening 11b is provided on the side wall of the drainage mass main body 11, and the downstream side of the inflow pipe portion 12 is inserted into the inside of the drainage mass main body 11 through the opening 11b, whereby the drainage mass main body 11 and the inflow pipe portion 12 are inserted. Is connected to. That is, in the present embodiment, the drainage mass main body 11 and the inflow pipe portion 12 are configured as separate bodies, and the inflow pipe portion 12 is inserted from the outside to the inside of the drainage mass main body 11.

The inflow pipe portion 12 is arranged on the first horizontal pipe portion 121 arranged on the upstream side, the inclined pipe portion 122 arranged on the downstream side of the horizontal pipe portion 121, and the inclined pipe portion 122 on the downstream side of the inclined pipe portion 122. Includes the second horizontal pipe portion 123. The first horizontal pipe portion 121, the inclined pipe portion 122, and the second horizontal pipe portion 123 may be integrally molded. The bottom of each of the first horizontal pipe portion 121 and the second horizontal pipe portion 123 (the bottom of the inner wall of the pipe) is horizontal or substantially horizontal. The pipe bottom of the inclined pipe portion 122 is inclined downward to the downstream side. Therefore, each pipe bottom of the inclined pipe portion 122 and the second horizontal pipe portion 123 is located below the pipe bottom of the first horizontal pipe portion 121. In other words, the downstream pipe bottom of the inflow pipe portion 12 is located below the upstream pipe bottom of the inflow pipe portion 12.

Although not shown, a pipe (upstream pipe on the indoor drainage facility 2 side) constituting the drainage pipe 1 is connected to the upstream opening 12a of the inflow pipe portion 12 (first horizontal pipe portion 121). .. Specifically, the outer diameter of the upstream pipe is substantially equal to the inner diameter of the first horizontal pipe portion 121, and the downstream end portion of the upstream pipe is inserted into the first horizontal pipe portion 121. A step 121a is provided along the inner circumference of the pipe at the boundary of the first horizontal pipe portion 121 with the inclined pipe portion 122. The inner peripheral surface of the inclined pipe portion 122 may have a curved surface that bulges outward when viewed from the pipe axis of the inclined pipe portion 122. This curved surface makes it possible to smooth the flow of drainage. The inner diameter of each of the inclined pipe portion 122 and the second horizontal pipe portion 123 may be substantially equal to the inner diameter of the upstream pipe inserted into the first horizontal pipe portion 121. The tip of the upstream pipe inserted into the first horizontal pipe portion 121 abuts on the step 121a, whereby positioning of the upstream pipe in the insertion direction is performed.

The outer diameter of the second horizontal pipe portion 123 is substantially equal to the diameter of the opening 11b of the drainage mass main body 11, and the second horizontal pipe portion 123 is inserted into the inside of the drainage mass main body 11 from the opening 11b. That is, the downstream opening 12b of the inflow pipe portion 12 (second horizontal pipe portion 123) is located on the inner side of the drainage mass main body 11 with respect to the opening 11b of the drainage mass main body 11. A protruding portion 123a is provided along the outer periphery of the pipe at the boundary of the second horizontal pipe portion 123 with the inclined pipe portion 122. When the second horizontal pipe portion 123 is inserted into the drainage mass main body 11, the protruding portion 123a of the second horizontal pipe portion 123 abuts on the side wall around the opening 11b in the drainage mass main body 11, whereby the second horizontal pipe portion 123 is in contact with the side wall. Positioning of the pipe portion 123 in the insertion direction is performed.

On the side wall around the opening 11b in the drainage mass main body 11, a projecting portion 11c protruding outward from the drainage mass main body 11 may be provided. In this case, the protruding portion 11c of the drainage mass main body 11 may be arranged in a cylindrical shape so as to surround the opening 11b, and the tip surface of the protruding portion 11c may be flush with each other. By doing so, the tip surface of the protruding portion 11c of the drainage mass main body 11 and the side surface (downstream side) of the protruding portion 123a of the second horizontal pipe portion 123 can be brought into surface contact with each other without using packing or the like. , The inflow pipe portion 12 and the drainage mass main body 11 can be satisfactorily connected.

In the present embodiment, in order to facilitate the flow of filth and the like that have passed through the downstream opening 12b of the second horizontal pipe portion 123 to the downstream side together with the drainage, the bottom of the drainage mass main body 11 is set to the bottom of the second horizontal pipe portion 123. That is, it may be located further below the bottom of the inflow pipe portion 12 on the downstream side. In this case, the drainage mass main body 11 may be provided with an inclined portion that inclines downward from the lower end of the downstream side opening 12b of the second horizontal pipe portion 123 to the bottom of the drainage mass main body 11. Further, a horizontal portion connected to the inclined portion and supporting the second horizontal pipe portion 123, and a support portion supporting the horizontal portion and located below the opening 11b of the drainage mass main body 11, respectively, are drainage masses. It may be provided on the main body 11.

The inclination of the inclined pipe portion 122 is such that the height difference between the pipe bottom of the first horizontal pipe portion 121 and the pipe bottom of the second horizontal pipe portion 123 is the upstream pipe (the pipe connected to the inflow pipe portion 12 from the upstream side). It may be set so as to be 23% or more of the inner diameter. Further, the inclination of the inclined pipe portion 122 is such that the extension line (broken line in FIG. 2) of the pipe axis (central axis) of the first horizontal pipe portion 121 does not intersect with the inner wall surface of the inclined pipe portion 122. It may be set to pass through the downstream opening 12b of the. In other words, the height difference between the bottom of the first horizontal pipe portion 121 and the bottom of the second horizontal pipe portion 123 may be set to less than 50% of the inner diameter of the inclined pipe portion 122 (inner diameter of the upstream pipe). ..

The outflow pipe portion 13 may be integrally molded with the drainage mass main body 11. The bottom of the drainage mass main body 11 and the pipe bottom of the outflow pipe portion 13 may be located at substantially the same height. Although not shown, a pipe (downstream pipe on the sewer pipe side) constituting the drainage pipe 1 is connected to the opening (downstream side opening) of the outflow pipe portion 13. Specifically, the outer diameter of the downstream pipe is substantially equal to the inner diameter of the opening side of the outflow pipe portion 13, and the upstream end portion of the downstream pipe is inserted into the outflow pipe portion 13. A step 13a is provided inside the outflow pipe portion 13 along the inner circumference of the pipe, and the inner diameter of the outflow pipe portion 13 on the upstream side of the step 13a is the inner diameter on the opening side of the outflow pipe portion 13, that is, the outer diameter of the downstream pipe. Is smaller than. As a result, the tip of the downstream pipe inserted into the outflow pipe portion 13 comes into contact with the step 13a, whereby positioning of the downstream pipe in the insertion direction is performed.

The check valve 14 has a substantially disk-shaped valve body 141 configured so that the downstream opening 12b of the inflow pipe portion 12 can be closed. The check valve 14 includes a support portion 142 that rotatably supports the valve body 141, a rotation shaft 143 provided on the opposite side of the valve body 141 in the support portion 142, and a bearing member 15 that pivotally supports the rotation shaft 143. And further. On the upper side of the opening 11b in the inner wall of the drainage mass main body 11, an extension portion 111 extending inward of the drainage mass main body 11 is provided along the outer peripheral top of the second horizontal pipe portion 123, and the bearing member 15 extends. It is fixed on the setting portion 111 by a method such as adhesion, screwing, or welding. Further, the bearing member 15 may be detachably fixed by being fitted to the extending portion 111 or the like. By making it removable, when the bearing member 15 is damaged, it can be easily replaced. The rotating shaft 143 pivotally supported by the bearing member 15 is arranged on the upstream side of the position of the center of gravity of the valve body 141. The extension portion 111 may be integrally molded with the drainage mass main body 11.

The opening surface of the downstream opening 12b of the inflow pipe portion 12 (second horizontal pipe portion 123) is substantially vertical facing, and the valve body 141 substantially extends the downstream opening 12b along this vertical facing when no drainage is performed. Close vertically. That is, the angle formed by the disk shape of the valve body 141 with respect to the vertical surface when the downstream opening 12b is closed is substantially 0 °. A valve seat surface 12c that can come into contact with the valve body 141 is provided on the downstream end surface of the inflow pipe portion 12, that is, the peripheral edge portion of the downstream opening 12b in the inflow pipe portion 12. The valve seat surface 12c is configured to be able to come into contact with the valve body 141 when drainage flows back. The valve seat surface 12c may be provided in a divergent manner in the downstream direction from the inner peripheral surface of the inflow pipe portion 12 (second horizontal pipe portion 123) to the end surface. That is, the valve seat surface 12c may be a tapered surface (inclined surface). An annular packing 16 that can be in close contact with the valve seat surface 12c of the inflow pipe portion 12 is provided on the outer peripheral surface of the valve body 141.

In the present embodiment, for example, an invert portion 11d having a semicircular cross section may be provided at the bottom of the drainage mass main body 11. The bottom of the invert portion 11d and the bottom of the outflow pipe portion 13 may be located at substantially the same height. The invert portion 11d may be provided so as to extend from the bottom portion of the drainage mass main body 11 to the inclined portion from the downstream side opening 12b of the second horizontal pipe portion 123. By doing so, since the inflow pipe portion 12 and the outflow pipe portion 13 are connected by the invert 11d, it is possible to prevent the filth and the like in the drainage from staying.

<Operation example of backflow prevention mass>
When there is no drainage, the valve body 141 of the check valve 14 comes into contact with the valve seat surface 12c of the inflow pipe portion 12 and closes the downstream opening 12b of the inflow pipe portion 12. If drainage flows out from the indoor drainage facility 2 while the valve body 141 closes the downstream opening 12b, the drainage flowing into the inflow pipe portion 12 through the drainage pipe passage 1 will be the valve seat of the inflow pipe portion 12. The valve body 141 in contact with the surface 12c is pushed open by water pressure. As a result, the drainage flows from the inflow pipe portion 12 to the drainage mass main body 11, and the drainage flows out from the backflow prevention mass 10 through the outflow pipe portion 13. Further, since the center of gravity of the valve body 141 is located on the downstream side of the rotation shaft 143, when the drainage flows away from the inflow pipe portion 12, the valve body 141 closes the downstream opening 12b again by its own weight.

On the other hand, even if the drainage overflowing beyond the drainage capacity of the sewer pipe due to heavy rain or the like flows back through the drainage pipe line 1, the valve body 141 of the backflow prevention valve 14 blocks the downstream opening 12b of the inflow pipe portion 12. Therefore, the drainage does not enter the drainage pipe 1 on the upstream side of the check valve 14. Therefore, it is possible to prevent the backflow drainage and the air pumped by the drainage from being ejected from the indoor drainage facility 2.

<Effect of embodiment>
According to the backflow prevention mass 10 of the present embodiment described above, the downstream side pipe bottom is located below the upstream side pipe bottom in the drainage inflow pipe portion 12 provided on the side wall of the drainage mass main body 11. Therefore, when the drainage flows from the upstream side to the downstream side of the inflow pipe portion 12, the flow velocity of the drainage increases. The flow makes it easier to open. Therefore, even when the amount of drainage is small, it is possible to prevent the backflow prevention mass 10 from being clogged with drainage due to filth or the like. In particular, when the flow gradient of the pipe connected to the inflow pipe portion 12 from the upstream side is small and the flow velocity of the drainage in the pipe is small, the backflow prevention mass 10 of the present embodiment is useful.

Further, in the backflow prevention mass 10 of the present embodiment, the bottom portion of the drainage mass main body 11 may be located below the bottom of the downstream pipe portion of the inflow pipe portion 12. By doing so, it is possible to avoid a situation in which filth or the like accumulates on the downstream side of the valve body 141 of the check valve 14 in the drainage mass main body 11 and hinders the opening of the valve body 141. Therefore, it is possible to further suppress the occurrence of drainage clogging due to filth or the like in the backflow prevention mass 10.

Further, in the backflow prevention mass 10 of the present embodiment, the height difference between the downstream pipe bottom and the upstream pipe bottom in the inflow pipe portion 12 is 23% or more of the inner diameter of the pipe connected to the inflow pipe portion 12 from the upstream side. May be. By doing so, the flow velocity of the drainage can be sufficiently increased when the drainage flows from the upstream side to the downstream side of the inflow pipe portion 12, so that the valve body 141 of the check valve 14 is more easily opened by the flow of the drainage. Become. Therefore, it is possible to further suppress the occurrence of drainage clogging due to filth or the like in the backflow prevention mass 10.

Further, in the backflow prevention mass 10 of the present embodiment, the inflow pipe portion 12 is arranged on the upstream side and the pipe bottom is horizontal or substantially horizontal, and the first horizontal pipe portion 121 and the downstream side of the first horizontal pipe portion 121. It may include an inclined pipe portion 122 which is arranged in a pipe and whose bottom is inclined downward to the downstream side. By doing so, the pipe connected to the inflow pipe portion 12 from the upstream side can be easily connected to the first horizontal pipe portion 121 of the inflow pipe portion 12.

Further, in the backflow prevention mass 10 of the present embodiment, the inflow pipe portion 12 is arranged on the downstream side of the inclined pipe portion 122 and is connected to the drainage mass main body 11, and the pipe bottom is horizontal or substantially horizontal second horizontal. The pipe portion 123 may be further included. In this way, the second horizontal pipe portion 123 of the inflow pipe portion 12 can be easily attached to the side wall of the drainage mass main body 11.

Further, in the backflow prevention mass 10 of the present embodiment, the extension line of the pipe axis of the first horizontal pipe portion 121 passes through the downstream opening 12b of the inflow pipe portion 12 without intersecting the inner wall surface of the inclined pipe portion 122. You may. By doing so, it is possible to avoid a situation in which when the drainage flows from the upstream side to the downstream side of the inflow pipe portion 12, it collides with the vicinity of the pipe top (top of the inner wall of the pipe) of the inclined pipe portion 122 and the flow velocity of the drainage decreases. Therefore, it is possible to realize a state in which the valve body 141 of the check valve 14 is easily opened by the flow of drainage.

Further, in the backflow prevention mass 10 of the present embodiment, the first horizontal pipe portion 121, the inclined pipe portion 122, and the second horizontal pipe portion 123 may be integrally molded. By doing so, the number of components of the backflow prevention mass 10 can be reduced, so that the backflow prevention mass 10 can be easily assembled.

Further, in the backflow prevention mass 10 of the present embodiment, the downstream side of the inflow pipe portion 12 may be inserted into the inside of the drainage mass main body 11. By doing so, the configuration of the inflow pipe portion 12 becomes simple and the backflow prevention mass 11 can be easily assembled. Specifically, if the downstream end of the inflow pipe portion 12 is not inserted into the drainage mass main body 11 and is to be brought into direct contact with the cylindrical side wall of the drainage mass main body 11, the drainage mass main body 11 in the inflow pipe portion 12 is to be brought into direct contact with the cylindrical side wall. The connection with and must be formed into a complex shape. On the other hand, in the present embodiment, as described above, the inflow pipe portion 12 and the drainage mass main body 11 can be satisfactorily connected without using packing or the like.

Further, in the backflow prevention mass 10 of the present embodiment, the valve body 141 substantially vertically closes the downstream opening 12b of the inflow pipe portion 12 when no drainage is performed, and forms a peripheral edge of the downstream opening 12 of the inflow pipe portion 12. A valve seat surface 12c configured to be in contact with the valve body 141 when the drainage flows back may be provided. By doing so, it becomes easy to open and close the valve body 141 at the time of drainage, and when the backflow of drainage occurs, the situation where the air is pumped to the upstream side is prevented and the drainage pipeline is destroyed. Can be suppressed. In this case, if the valve seat surface is provided in a divergent manner in the downstream direction from the inner peripheral surface of the inflow pipe portion 12 to the end surface, the valve body is provided with a weaker force (water pressure) when the backflow of drainage occurs. The water blocking effect of 141 can be surely obtained.

<Example>
Hereinafter, examples will be described. In this embodiment, "the height difference between the downstream side pipe bottom of the inflow pipe portion 12 and the upstream side pipe bottom" and "the bottom of the drainage mass main body 11 and the downstream side pipe bottom of the inflow pipe portion 12" in the backflow prevention mass 10. The sweepability test of the backflow prevention mass 10 was performed while changing the combination of "height difference".

Specifically, as shown in FIG. 4, in the backflow prevention mass 10, there are four patterns of 0 mm, 10 mm, 20 mm, and 30 mm as "height difference between the downstream side pipe bottom and the upstream side pipe bottom of the inflow pipe portion 12". Was set, and 5 patterns of 0 mm, 10 mm, 20 mm, 30 mm, and 40 mm were set as the "height difference between the bottom of the drainage mass main body 11 and the bottom of the downstream pipe of the inflow pipe portion 12". In FIG. 4, the same components as those of the backflow prevention mass 10 shown in FIG. 2 are designated by the same reference numerals. Further, due to the upstream pipe (not shown) inserted into the first horizontal pipe portion 121, the substantial pipe bottom of the first horizontal pipe portion 121 (substantially upstream side pipe bottom of the inflow pipe portion 12) is an upstream pipe. However, the dimensions shown in FIG. 4 take this wall thickness into consideration.

In the drainage test, in the drainage pipe 1 shown in FIG. 1, flowing down objects (pseudo-dirt, etc.) are flushed together with drainage from the water-saving toilet which is the indoor drainage facility 2, and swept depending on whether or not the backflow prevention mass 10 can be passed. The flowability was evaluated.

The drainage pipe line 1 was composed of an indoor pipe made of a vinyl chloride pipe VU75 having an extension distance of 1800 mm and an outdoor pipe made of a vinyl chloride pipe VU100 having an extension distance of 11700 mm. The backflow prevention mass 10 and the other drainage masses 3A, 3B, and 3C were arranged in the outdoor piping portion of the drainage pipe line 1. Specifically, the drainage mass 3A is arranged at a point 1300 mm downstream from the connection point between the indoor pipe and the outdoor pipe, and the drainage mass 3B is arranged at a point 4400 mm downstream from the drainage mass 3A to drain the water. The mass 3C was arranged at a point 1500 mm downstream from the drainage mass 3B, and the backflow prevention mass 10 was arranged at a point 4500 mm downstream from the drainage mass 3C. Further, the flow gradient of the indoor pipe is set to 1/100, a head of 500 mm is provided between the indoor pipe and the outdoor pipe, the flow gradient of the outdoor pipe to the drainage mass 3C is set to 2/100, and the backflow from the drainage mass 3C is set. The flow gradient up to the prevention mass 10 was set to 1/200.

In addition, in the sweepability test, in principle, a large drainage of a water-saving toilet is performed once, and if the flow-down material does not reach the backflow prevention mass 10 and stays in the middle, the place where the flow-down material stays is from the drainage mass 3B. If it is on the upstream side, a large drainage of the water-saving toilet is performed once more, and if the place where the flowing material stays is the drainage mass 3B or the downstream side, the flowing material reaches the backflow prevention mass 10. We added a small amount of drainage to the water-saving toilet. PVA (polyvinyl alcohol) sponge pseudo filth (φ25, length 80 mm, specific gravity about 1.05) (hereinafter referred to as PVA pseudo filth) and single toilet paper (90 cm 3 folds as one unit) As a "normal" amount, 4 1/2 cut products of PVA pseudo filth and 2 sheets of single toilet paper are poured down, and as a "large amount" amount, 1/2 cut product of PVA pseudo filth. Six pieces, eight 1/4 cut products of PVA pseudo-filth, and eight pieces of single toilet paper were poured down.

Various "height difference between the downstream pipe bottom of the inflow pipe portion 12 and the upstream pipe bottom" and "height difference between the bottom of the drainage mass main body 11 and the downstream pipe bottom of the inflow pipe portion 12" in the backflow prevention mass 10. Table 1 below shows the results of the sweepability test for each of these combinations as "(number of times the flow-down object passed through the valve body 141 of the check valve 14) / (number of tests)".

As shown in Table 1, by locating the downstream pipe bottom in the inflow pipe portion 12 below the upstream pipe bottom, the sweepability of the backflow prevention mass 10 is improved. Further, when the "height difference between the downstream pipe bottom of the inflow pipe portion 12 and the upstream pipe bottom" is the same, the bottom of the drainage mass main body 11 is positioned below the downstream pipe bottom of the inflow pipe portion 12. Thereby, the sweepability of the backflow prevention mass 10 is further improved. In particular, by setting the "height difference between the downstream pipe bottom and the upstream pipe bottom of the inflow pipe portion 12" to about 25 mm or more, more preferably 30 mm or more, sufficient sweeping can be performed even for a "large amount" of flowing objects. Flowability can be obtained. In this embodiment, the inner diameter of the pipe (vinyl chloride pipe VU100) connected to the inflow pipe portion 12 from the upstream side is 107 mm, so that “the height difference between the downstream side pipe bottom and the upstream side pipe bottom of the inflow pipe portion 12”. However, it can be seen that particularly excellent sweepability can be obtained by setting the inner diameter of the pipe connected to the inflow pipe portion 12 from the upstream side to about 23% or more.

As described above, if the flow gradient of the pipe connected to the inflow pipe portion 12 from the upstream side (1/200 in this embodiment) is small, the flow velocity of the drainage in the pipe becomes small and the flow-down material stays. Although it is likely to occur, the sweepability of the backflow prevention mass 10 can be improved by the "height difference between the downstream side pipe bottom and the upstream side pipe bottom of the inflow pipe portion 12".

If the "height difference between the downstream side pipe bottom and the upstream side pipe bottom of the inflow pipe part 12" is set to about 50% or less of the outer diameter of the pipe connected to the inflow pipe part 12 from the upstream side, the inflow pipe part Since a general-purpose size joint can be used as 12, there is a cost advantage. Further, if the "height difference between the downstream pipe bottom and the upstream pipe bottom of the inflow pipe portion 12" is set to about 100% or less of the outer diameter of the pipe connected to the inflow pipe portion 12 from the upstream side, the backflow prevention mass is set. Since it is possible to suppress an increase in the depth of burying 10 in the ground, there is an advantage that workability is improved.

In this embodiment, apart from the sweepability test described above, when a small amount of water is flowed through the drainage pipe line 1, whether or not the water stays on the upstream side of the valve body 141 of the backflow prevention valve 14. A retention test was performed to evaluate (whether the valve body 141 can be pushed open). Specifically, 100 cc of water was flowed from the drainage mass 3B, and it was evaluated whether the total amount of 100 cc of water could pass through the downstream opening 12b of the inflow pipe portion 12 without staying in front of the valve body 141. The retention test was performed three times each for two patterns: a state in which the valve body 141 was naturally closed after normal drainage, and a state in which the valve body 141 was pressed and closed by a human hand simulating the backflow of drainage. Carried out.

As a result of the retention test, in normal drainage, when the "height difference between the downstream pipe bottom and the upstream pipe bottom of the inflow pipe portion 12" is 10 mm, 20 mm, or 30 mm, the total amount of water of 100 cc is the inflow pipe portion 12. Passed through the downstream opening 12b of. On the other hand, when simulating after the backflow of drainage, if the "height difference between the downstream side pipe bottom and the upstream side pipe bottom of the inflow pipe portion 12" is 20 mm or more, the total amount of 100 cc of water is on the downstream side of the inflow pipe portion 12. It passed through the opening 12b.

Further, in the case of a small amount of water, the valve body 141 does not open due to the drainage speed given by the "height difference between the downstream side pipe bottom and the upstream side pipe bottom of the inflow pipe portion 12," but is in front of the valve body 141. It was confirmed that a small amount of water temporarily stagnated in the valve body 141 due to the head pressure generated by the temporary retention, and the water passed through the valve body 141. From this, it is sufficient that the "height difference between the downstream side pipe bottom and the upstream side pipe bottom of the inflow pipe portion 12" is a height difference that causes a water depth sufficient to give a sufficient head pressure to the valve body 141. found. Further, in order to prevent the retention of a small amount of water, the downstream opening 12b in the inflow pipe portion 12 is larger than the size of the “height difference between the downstream side pipe bottom and the upstream side pipe bottom of the inflow pipe portion 12” itself. It was found that it is effective to shorten the length of the horizontal pipe portion (second horizontal pipe portion 123) in front of the above as much as possible.

(Other embodiments)
In the above embodiment (including an embodiment, the same applies hereinafter), a backflow prevention mass 10 is provided in the drainage pipe line 1 configured in series. However, the present invention is not limited to this, and a backflow prevention mass 10 may be provided in a drainage pipeline including a plurality of pipes configured in parallel using, for example, a drainage header or the like.

Further, in the above embodiment, one drainage inflow pipe portion 12 and one drainage pipe portion 13 are provided on the side wall of the drainage mass main body 11. However, the present invention is not limited to this, and a plurality of inflow pipe portions 12 may be provided on the side wall of the drainage mass main body 11, or a plurality of outflow pipe portions 13 may be provided.

Further, in the above-described embodiment, the inflow pipe portion 12 is composed of a first horizontal pipe portion 121, an inclined pipe portion 122, and a second horizontal pipe portion 123. However, if the downstream pipe bottom is located below the upstream pipe bottom in the inflow pipe portion 12, in other words, the lower end of the downstream opening 12b in the inflow pipe portion 12 is lower than the lower end of the upstream opening 12a. The configuration of the inflow pipe portion 12 is not particularly limited as long as it is located at. For example, the first horizontal pipe portion and / or the second horizontal pipe portion 123 may not be provided. Alternatively, a third horizontal pipe portion may be provided in the middle of the inclined pipe portion 122.

Further, in the above embodiment, the inflow pipe portion 12 and the drainage mass main body 11 are separated, and the downstream side of the inflow pipe portion 12 is inserted into the drainage mass main body 11, but instead of this, the inflow pipe portion 12 The downstream end portion of the drainage mass may be attached to the side wall of the drainage mass main body 11, or the inflow pipe portion 12 and the drainage mass main body 11 may be integrally molded.

FIG. 5 shows a vertical cross-sectional view of a modified example of the backflow prevention mass 10. In FIG. 5, the same components as those of the backflow prevention mass 10 shown in FIG. 2 are designated by the same reference numerals. The modification shown in FIG. 5 differs from the backflow prevention mass 10 shown in FIG. 2 in that the inflow pipe portion 12 has a valve pipe 124 attached from the inside of the drainage mass main body 11 on the downstream side, and the valve pipe 124. A valve seat surface 12c that can come into contact with the valve body 141 is provided on the end surface on the downstream side of the valve body 141. According to this modification, since the valve pipe 124 opened and closed by the valve body 141 is attached from the inside of the drainage mass main body 11, the valve body 141 can be attached integrally with the valve tube 124, and the backflow prevention mass can be easily assembled. become.

In the modification shown in FIG. 5, the second horizontal pipe portion 123 is arranged on the upstream side as compared with the backflow prevention mass 10 shown in FIG. 2, and the valve pipe 124 is horizontally connected to the second horizontal pipe portion 123 from the downstream side. However, the valve pipe 124 may be configured as a part of the second horizontal pipe portion 123. An extension portion 111 extending inward of the drainage mass main body 11 may be provided on the inner side wall around the opening 11b in the drainage mass main body 11, and the valve pipe 124 may be supported by the extension portion 111. The valve pipe 124 may be adhered to the extension portion 111 in a state of being inserted into the cylindrical extension portion 111. The check valve 14 (bearing member 15) may be attached to the top of the valve tube 124. A recess 141a may be provided on the outer peripheral surface of the valve body 141, and a packing 16 such as a V packing may be attached to the recess 141a. In this way, since the valve seat surface 12c is a tapered surface (inclined surface), the adhesion of the packing 16 to the valve seat surface 12c is improved, and the water stopping effect of the valve body 141 at the time of backflow of drainage is further increased. ..

Although the embodiments have been described above, it will be understood that various modifications of the embodiments and details are possible without departing from the spirit and scope of the claims. Further, the above embodiments may be appropriately combined or replaced as long as the functions of the subject of the present disclosure are not impaired. Furthermore, the above-mentioned descriptions of "first", "second", ... Are used to distinguish the words and phrases to which these descriptions are given, and also limit the number and order of the words and phrases. is not it.

1 Drainage pipe 2 Indoor drainage equipment 3A, 3B, 3C Drainage mass 10 Backflow prevention mass 11 Drainage mass body 11a, 11b Opening 11c Protruding part 11d Invert part 111 Extension part 12 Inflow pipe part 12a Upstream side opening 12b Downstream side opening 12c Valve seat surface 121 1st horizontal pipe part 121a Step 122 Inclined pipe part 123 2nd horizontal pipe part 123a Protruding part 124 Valve pipe 13 Outflow pipe part 13a Step 14 Backflow prevention valve 141 Valve body 141a Recess 142 Support part 143 Rotating shaft 15 Bearing member 16 Packing

Claims (10)

It is a backflow prevention mass that is installed in the drainage pipe that connects the indoor drainage facility and the sewer pipe and prevents the intrusion of the drainage that flows back through the drainage pipe to the upstream side.
Drainage mass body and
The inflow pipe portion and the outflow pipe portion of the drainage provided on the side wall of the drainage mass main body,
A check valve provided in the drainage mass main body and having a valve body configured to close the downstream opening of the inflow pipe portion is provided.
The downstream pipe bottom of the inflow pipe portion is located below the upstream pipe bottom of the inflow pipe portion.
Backflow prevention mass. The bottom of the drainage mass body is located below the bottom of the downstream pipe of the inflow pipe.
The backflow prevention mass according to claim 1. The height difference between the downstream side pipe bottom and the upstream side pipe bottom in the inflow pipe portion is 23% or more of the inner diameter of the pipe connected to the inflow pipe portion from the upstream side.
The backflow prevention mass according to claim 1 or 2. The inflow pipe portion includes at least a valve pipe attached to the downstream side from the inside of the drainage mass main body.
A valve seat surface capable of contacting the valve body is provided on the downstream end surface of the valve tube.
The backflow prevention mass according to any one of claims 1 to 3. The inflow pipe portion is arranged on the upstream side and the pipe bottom is horizontal or substantially horizontal, and the first horizontal pipe portion is arranged on the downstream side of the first horizontal pipe portion and the pipe bottom is downward on the downstream side. Including at least an inclined pipe portion that is inclined,
The backflow prevention mass according to any one of claims 1 to 4. The first horizontal pipe portion and the inclined pipe portion are integrally molded.
The inflow pipe portion is inserted into the drainage mass main body, and the inflow pipe portion is inserted into the drainage mass body.
A valve seat surface capable of contacting the valve body is provided on the downstream end surface of the inflow pipe portion.
The backflow prevention mass according to claim 5. The inflow pipe portion is arranged downstream from the inclined pipe portion and further includes a second horizontal pipe portion connected to the drainage mass main body and having a horizontal or substantially horizontal pipe bottom.
The backflow prevention mass according to claim 5 or 6. The extension line of the pipe axis of the first horizontal pipe portion passes through the downstream opening of the inflow pipe portion without intersecting the inner wall surface of the inclined pipe portion.
The backflow prevention mass according to any one of claims 5 to 7. The downstream side of the inflow pipe portion is inserted into the inside of the drainage mass main body.
When there is no drainage, the valve body vertically closes the downstream opening of the inflow pipe portion.
A valve seat surface configured to be in contact with the valve body when drainage flows back is provided on the peripheral edge of the downstream opening in the inflow pipe portion.
The backflow prevention mass according to any one of claims 1 to 8. The valve seat surface is provided in a divergent manner in the downstream direction from the inner peripheral surface to the end surface of the inflow pipe portion.
The backflow prevention mass according to claim 9.

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