JP2021055535A - Catch basin - Google Patents

Abstract

To provide a catch basin with a backflow prevention valve that is easy to maintain, capable of reliably preventing only the reverse flow of drainage without causing clogging of drainage by foreign matters, etc.SOLUTION: There is provided a catch basin comprising an inlet, a backflow prevention valve to prevent the backflow of wastewater into the inlet, an outlet, an invert section connecting the inlet and outlet, and an inspection port opening above the invert section. The backflow prevention valve consists of a valve pipe attached to the inner wall surface or the inlet of the catch basin, and a valve body oscillatingly supported at the upper end on the downstream side of the valve pipe. The downstream opening end of the valve pipe 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.SELECTED DRAWING: Figure 1

Description

The present invention relates to a drainage system equipped with a check valve attached to the inlet of the drainage system to prevent the drainage flowing back from the sewer main from flowing back to the indoor drainage facility through the drainage system, and the amount of drainage is small. It also relates to drainage with a check valve that prevents only the flow of drainage (reverse flow drainage) during backflow without causing drainage clogging due to foreign matter.

Generally, drainage discharged from drainage facilities such as toilets in houses is discharged to the sewer by connecting the drainage pipe on the residential land side to the sewer main, but removal and inspection of foreign substances such as dust in the middle of the drainage pipe Drainage is usually installed before connecting the drainage pipe on the building side to the sewer main.

However, the amount of drainage that flows into the sewer main due to abnormal weather in recent years has increased, and if a large amount of rainwater flows into the sewer main in a short time due to a typhoon, etc., it overflows beyond the drainage capacity of the sewer main. There was a problem that the drainage flowed back through the drainage pipe and the drainage flowed back from the indoor drainage facility connected to the drainage pipe spouted into the building.

Therefore, in order to prevent the drainage flowing back from the sewer main from being ejected from the indoor drainage facility through the drainage, for example, Japanese Patent Application Laid-Open No. 2008-261223 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2010-126888. As described in Japanese Patent Application Laid-Open No. 11-241394 (Patent Document 3), a technique of attaching a check valve to an inflow port inside a drainage system is known.

Among these check valve, the check valve described in Patent Documents 1 and 2 is an outlet or flow of drainage so as to incline from the upstream side to the downstream side as the valve body moves from the upper part to the lower part. Since it is rotatably attached to the valve tube connected to the outlet, the valve body usually blocks the outlet or the open end of the valve tube by its own weight. Therefore, when the drainage flows from the indoor drainage facility to the drainage basin, the valve body is lifted by the drainage flow (pressure) to open the outlet or the opening end of the valve pipe. On the other hand, when the drainage flows back from the sewer main to the drainage, the valve body closes the outlet or the opening end of the valve pipe due to its own weight and the flow (pressure) of the drainage, so the drainage of the reverse flow is on the upstream side. Prevent backflow to the drainage pipe.

By the way, in recent years, with the spread of water-saving toilets, the amount of drainage during normal times has decreased significantly. Therefore, in the case of the check valve of the type described in Patent Documents 1 and 2, as described above, the outlet or the open end of the valve tube is normally closed, so that the amount of drainage is reduced in the normal state. If this happens, foreign matter such as dust accumulates around the closed valve body, making it difficult for it to flow, and there is a problem that the flow of normal drainage (forward flow drainage) is clogged.

On the other hand, in contrast to the check valve described in Patent Documents 1 and 2, the check valve described in Patent Document 3 drains the internal inflow port to a larger diameter than the external receiving port. Normally, the valve body opens the open end of the outflow port by providing a step portion at the lower part of the valve body and suspending the valve body to a position away from the inflow port so as to be swingable. Therefore, the check valve described in Patent Document 3 allows the flow of drainage flowing from the indoor drainage facility to the drainage basin, while when the drainage flows back from the sewer main to the drainage basin, the drainage flow ( Since the outlet is closed by pressure), it prevents the reverse flow drainage from flowing back to the drainage pipe on the upstream side.

However, the type of check valve described in Patent Document 3 is usually in a state where the open end of the outflow port is opened as described above, and there is a gap between the valve body and the step portion of the inflow port. A space is formed that allows the drainage that has flowed back into the invert portion of the drainage to go around to the back surface of the valve body before the surface on the downstream side. For this reason, especially when the water level of the drainage flowing back to the drainage rises gradually, the valve body receives the pressure of the drainage from the back surface, and the valve body moves in the direction of opening the outlet more widely. There is a problem that it is not possible to prevent the reverse flow drainage from flowing back to the drainage pipe on the upstream side.

Further, in the check valve described in Patent Document 3, it has been proposed to apply buoyancy to the valve body in order to smooth the closing operation of the valve body, but as described above, the valve body once serves the outlet. If it starts to move in the direction of opening larger, the buoyancy of the valve body acts to promote the movement, and it is unstable which movement the buoyancy of the valve body works to help the opening and closing of the valve body. There was also a problem such as.

Further, since the check valve described in Patent Document 3 cannot be basically removed from the inside of the drainage drain, there is a problem that maintainability such as inspection and parts replacement is poor despite the complicated structure. ..

Japanese Unexamined Patent Publication No. 2008-261223 Japanese Unexamined Patent Publication No. 2010-126888 Japanese Unexamined Patent Publication No. 11-241394

Therefore, according to the present invention, even when the amount of drainage is small, the drainage is not clogged by foreign matter or the like, and only the flow of drainage (reverse flow drainage) at the time of backflow can be reliably prevented, and the maintainability is further excellent. It is intended to provide a drainage system with a check valve.

In order to achieve the above object, the present inventors, regarding the check valve attached to the inflow port of the drainage basin, the shape and structure of the valve body and the valve pipe for supporting the valve body, the mounting mode thereof, etc. As a result of diligent studies, the inflow port of the drainage pipe is extended inward by extending the valve pipe, which is separated from the invert part of the drainage pipe and has an opening end that is inclined to recede upstream from the top to the bottom. By suspending a specially shaped valve body with a buoyancy generating part at a specific position to the valve pipe so as to be swingable, drainage during backflow (reverse flow) can be performed without causing drainage clogging due to foreign matter or the like. We have found that it is the most effective in preventing only the flow of wastewater), and have completed the present invention.

To improve the maintainability of the check valve, the flange that fixes the check valve to the inner wall of the drain is separated into a fixed flange and a movable flange that can be detachably attached to the fixed flange, and then to the movable flange. We have found that it is most effective to attach a check valve body such as a valve tube or a valve body, and have completed the present invention.

That is, according to the present invention, an inflow port, a check valve for preventing the backflow of drainage to the inflow port, an inflow port, an invert portion connecting the inflow port and the outflow port, and In a drainage basin provided with an inspection port opened above the invert portion, the check valve is a valve pipe attached to the inner wall surface or the inflow port of the drainage basin and an upper end on the downstream side of the valve pipe. It has a valve body oscillatingly supported in a portion, and the opening end on the downstream side of the valve tube is formed so as to incline from the downstream side to the upstream side from the upper part to the lower part. Drainage is provided, which is characterized by being. Further, it is preferable that the valve pipe is attached so as to project inward from the inner wall surface of the drainage pipe at an upper position away from the invert portion.

More specifically, according to the present invention, an inflow port, a check valve attached to the inflow port, an inflow port, an invert portion connecting the inflow port and the inflow port, and the invert portion. A drainage basin with an inspection port opened above the drainage basin, wherein the check valve has an opening communicating with the inflow port and is attached to the inner wall surface or the inflow port of the drainage basin. A valve pipe that communicates with the opening and is supported by the mounting portion, and the opening end surface on the downstream side of the valve pipe is formed so as to incline from the downstream side to the upstream side from the upper part to the lower part. The drainage drainage is characterized in that the valve pipe is provided with a valve body swingably pivotally supported at the upper end portion of the opening end surface in order to open and close the opening end surface of the valve pipe. Provided. When the inner wall surface of the drainage pipe is curved, it is preferable that the mounting portion forms a curved flange portion.

Further, in the plumb bob of the present invention, the valve body is curved so that the surface on the downstream side of the valve body is recessed from the downstream side to the upstream side, and the valve body is suspended from the upper end of the valve pipe. When the buoyancy is generated, it is located above the position at half the height of the valve body in the vertical direction and upstream of the vertical plane passing through the swing axis of the valve body, which is smaller than the specific weight of water. It is preferable to have.

The backflow prevention valve of the drainage pipe of the present invention is provided with a valve pipe having an open end inclined so as to retreat from the upper part to the lower part toward the upstream side, and the valve body swings at the upper end portion of the valve pipe. Can be hung freely. For this reason, the check valve opens the open end of the valve pipe under normal conditions and allows the forward flow of drainage flowing from the indoor drainage facility to the drainage basin, so that foreign matter is allowed even when the amount of drainage is small. There is no clogging of drainage due to such factors.

Further, in the present invention, when the valve pipe is attached to the inside of the drainage pipe, the opening end of the valve pipe is designed to open at an upper position away from the invert portion of the drainage pipe. The drainage that has flowed into the invert part of the valve body does not wrap around to the back surface of the valve body on the downstream side. Therefore, in the present invention, the valve body is prevented from moving in the direction of opening the open end of the valve pipe by receiving the pressure of the drainage from the back surface of the reverse flow of the drainage.

Further, in the present invention, the valve body is curved so that the surface on the downstream side is recessed from the downstream side to the upstream side. For this reason, the valve body receives a greater resistance to the reverse flow drainage flow than the forward flow drainage flow, so that the valve is surely opposed to the drainage flow flowing into the invert portion of the reverse flow drainage drainage. It operates so as to close the open end of the pipe, and is prevented from malfunctioning so as to open the open end of the valve pipe.

Further, in the present invention, when the valve body is suspended from the upper end of the valve tube, the valve body is above the position of half the height of the valve body in the vertical direction and the valve body sways. A buoyancy generating part smaller than the specific weight of water arranged on the upstream side of the vertical plane passing through the moving axis is provided. That is, in the normal state where the valve body is suspended from the valve tube, the center of the buoyancy of the buoyancy generating part is located on the upstream side of the vertical plane passing through the swing axis of the valve body, so that the drainage is drained. When the water flows back to the valve body, a moment that rotates the valve body so as to close the open end of the valve tube acts. Therefore, the valve body can more reliably close the open end of the valve pipe against the backflow of drainage, and it is also prevented from malfunctioning so as to open the open end of the valve pipe.

In addition, since the buoyancy generating part is located above the position of half the height of the valve body in the vertical direction, the water level of the drainage flowing back into the drainage basin is half the height of the valve body. In the following cases, basically no buoyancy is generated in the valve body, and effective buoyancy for rotating the valve body is generated only when the water level of the drainage becomes half or more of the height of the valve body.

For this reason, when the drainage flowing back into the drainage basin has a low water level, the valve body receives a large resistance to the reverse flow of the drainage due to the curved shape of the valve body described above, so that the valve body flows backward. It operates so as to surely close the open end of the valve pipe with respect to the flow of the drainage flowing into the invert portion of the drainage pipe, and also prevents malfunction to open the open end of the valve pipe. On the other hand, when the drainage that flows back into the drainage becomes a high water level, the buoyancy causes a moment to rotate the valve body so as to close the opening end of the valve pipe, so the backflow drainage is at a low water level. Combined with the effect at a certain time, it operates so as to more reliably close the opening end of the valve pipe with respect to the flow of drainage flowing into the invert part of the backflow drainage.

As described above, the check valve attached to the drainage basin of the present invention does not cause drainage clogging due to foreign matter or the like even when the amount of drainage is small due to the synergistic effect of the special valve pipe shape and the special valve body structure. , Only the reverse flow of drainage (backflow) can be reliably prevented.

In the present invention, the buoyancy generating portion can be formed, for example, by forming a hollow portion in the valve body, or by forming the valve body with a resin member smaller than the specific gravity of water. Good.

When the buoyancy generating portion is formed by the hollow portion of the valve body, the hollow portion joins the downstream side wall surface portion forming the downstream surface of the valve body and the upstream side wall surface portion forming the upstream surface at each peripheral edge portion. It is preferable to partition and form the surface. When the valve body is composed of a plurality of parts of the downstream side wall surface portion and the upstream side wall surface portion as described above, the peripheral portion of both is provided by providing a difference between the dented condition of the downstream side wall surface portion and the dented condition of the upstream side wall surface portion. By joining, a hollow portion can be easily formed at an arbitrary position in the valve body.

Further, as described above, when the valve body is composed of a plurality of parts of the downstream side wall surface portion and the upstream side wall surface portion, the specific gravity of the upstream side wall surface portion is made smaller than the specific gravity of the downstream side wall surface portion, and is smaller than the specific gravity of the water. It is also preferable to do so.

If the above difference is provided between the specific gravity of the upstream side wall surface and the specific gravity of the downstream side wall surface, when the valve body is immersed in the drainage due to the backflow, the valve body has an upstream side wall having a smaller specific gravity from the downstream side wall surface. Since a moment that rotates toward the surface so as to close the open end of the valve pipe works, it is possible to reliably prevent the backflow of drainage, and the valve body mistakenly opens the open end of the valve pipe. It can also be prevented from operating. Further, if the specific gravity of the upstream side wall surface portion is set to be at least smaller than the specific gravity of water, it is possible to prevent the valve body from losing a predetermined buoyancy even when the hollow portion is destroyed due to damage to the valve body or the like.

The flange portion of the check valve can be composed of a fixed flange attached to the inner wall surface of the drainage pipe and a movable flange to which the valve pipe supporting the valve body is connected and detachably attached to the fixed flange. ..

By dividing the flange into a fixed flange and a movable flange that can be attached to and detached from the fixed flange, the valve pipe connected to the movable flange and the valve body supported by the valve pipe can be easily removed from the drainage. This makes it possible to improve maintainability such as inspection and replacement of the valve pipe and valve body. For this reason, the fixed flange is provided with a pair of vertically extending grooves for receiving both ends of the movable flange, and both ends of the movable flange can be inserted and removed vertically into the pair of grooves of the fixed flange. It is preferable to attach it to.

When the flange is divided into a fixed flange attached to the inner wall surface of the drainage pipe and a movable flange, the fixed flange has a guide pipe inserted into the inflow port of the drainage pipe on the opposite side of the valve pipe. It is preferable to provide it in. Therefore, it is preferable that the guide pipe communicates with the valve pipe and has substantially the same inner diameter as the valve pipe.

If a guide pipe is provided on the fixed flange, the fixed flange can be fixed to the inner wall surface of the drainage pipe with less rattling by inserting the guide pipe into the inflow port of the drainage pipe. Further, in the check valve of the present invention, a second fixing flange is connected to an inflow side connecting pipe having an inner peripheral surface having substantially the same diameter as the outer peripheral surface of the guide pipe, and is attached to the outer wall surface of the drainage pipe. By preparing, the guide pipe of the fixed flange is inserted through the side wall of the drainage pipe and inserted into the inside of the inflow side connection pipe, and the side wall of the drainage pipe is sandwiched between the fixed flange and the second fixed flange. The fixing flange can also be firmly fixed to the inner wall surface of the drain. When the outer wall surface of the drainage pipe is curved, it is preferable that the second fixed flange portion is curved.

Further, since the end of the guide pipe inserted into the inside of the inflow side connecting pipe forms a step portion on the inner peripheral surface of the inflow side connecting pipe, the external connecting pipe inserted into the inside of the inflowing side connecting pipe It can also function as a stopper that comes into contact with the end, which is convenient.

According to the drainage of the present invention, due to the synergistic effect of the special valve pipe shape of the check valve and the special valve body structure, even when the amount of drainage is small, the drainage is not clogged by foreign matter and the like, and the drainage flows back. It is possible to operate the valve pipe so as to surely close the opening end of the valve pipe against the flow of the reverse flow drainage flowing into the invert portion, and the valve body mistakenly opens the opening end of the valve pipe. It can also be reliably prevented from operating.

Further, according to the drainage pipe of the present invention, the flange portion is connected to the movable flange by dividing the flange portion into a fixed flange fixed to the inner wall of the drainage pipe and a movable flange that can be detachably attached to the fixed flange. Since the valve pipe and the valve body supported by the valve pipe are drained, it can be easily removed, and maintainability such as inspection and replacement of the valve pipe and the valve body is improved.

It is a vertical sectional view of the drainage basin of this invention which attached the check valve. It is a side view of the drainage basin shown in FIG. It is a top view of the drainage basin shown in FIG. It is a vertical sectional view of the aspect which removed the check valve shown in FIG. It is a side view of the check valve which is shown in FIG. It is a front view of the check valve which is shown in FIG. It is a top view of the check valve shown in FIG. It is a bottom view of the check valve shown in FIG.

Hereinafter, the drainage basin to which the check valve according to the embodiment of the present invention is attached will be described in detail with reference to the drawings. The present invention is not limited to the examples shown below, and various modifications can be made without departing from the technical idea of the present invention.

FIG. 1 shows a vertical cross-sectional view cut along the central axis of the drainage basin 1 of the present invention to which the check valve 2 is attached. Further, FIG. 2 shows a side view of the drainage basin 1 shown in FIG. 1, and FIG. 3 shows a top view of the drainage basin 1 shown in FIG.

As shown in FIGS. 1 to 3, the drainage basin 1 to which the check valve 2 of the present embodiment is attached connects the inflow port 11, the outflow port 12, and the inflow port 11 and the outflow port 12. It includes an invert portion 13 and a riser pipe 15 having an inspection port 14 opened above the invert portion, all of which are molded of synthetic resin. Further, the drainage main body may be made of concrete or a combination of a concrete material and a synthetic resin material.

The check valve 2 is attached to the inner side of the inflow port 11 of the drainage pipe 1, and the backflow prevention valve 2 has an opening 31 communicating with the inflow port 11 and the flow of the inner wall surface 16 of the drainage pipe 1. A curved flange portion 3 attached to the inlet 11 and a valve pipe 4 communicating with the opening 31 and supported by the flange portion 3, as the opening end surface 41 on the downstream side of the valve pipe 4 moves from the upper part to the lower part. The valve pipe 4 is formed so as to incline from the downstream side to the upstream side, and is swingably supported by the upper end portion 42 of the opening end surface 41 in order to open and close the opening end surface 41 of the valve pipe 4. It is provided with a valve body 5.

The valve pipe 4 has an open end (face) 41 inclined so as to recede from the upper portion to the lower portion toward the upstream side, and the upper end portion 42 of the valve pipe 4 has a valve body 5 having a special shape. Is swayably suspended. Therefore, in the normal state, the check valve 2 of the present embodiment opens the open end (face) 41 of the valve pipe 4 as shown in FIG. 1 from the indoor drainage facility (not shown). Since the normal flow of drainage (forward flow drainage) that flows into the drainage 1 is allowed, even when the amount of drainage is small, the drainage is not clogged by foreign matter.

Further, the valve pipe 4 protrudes inward from the inner wall surface 16 of the drainage pipe 1, and the opening end (face) 41 of the valve pipe 4 is drained so as to open at an upper position away from the invert portion 13. It is installed inside the. Therefore, the drainage flowing back from the outlet 12 of the drainage basin 1 to the invert portion 13 is obstructed by the lower part of the valve pipe 4 protruding into the inside of the drainage basin 1, and is more than the surface 51 on the downstream side of the valve body 5. It is not possible to go around to the back surface (upstream surface 52) first. Therefore, in the check valve 2 of the present embodiment, the valve body 5 receives the pressure of drainage from the back surface (surface 52 on the upstream side) of the flow of drainage (drainage of reverse flow) at the time of backflow. It is prevented from moving in the direction of opening the open end (face) 41 of the pipe 4.

In FIG. 4, among the check valve 2 shown in FIG. 1, the check valve 2 including the valve body 5, the valve pipe 4, and a part 33 of the flange portion 3 is removed from the inner wall surface 16 of the drainage 1. In this aspect, a vertical cross-sectional view of the check valve 2 cut along the central axis thereof is shown.

As will be understood with reference to FIGS. 1 and 4, the valve body 5 of the check valve 2 is curved so that the surface 51 on the downstream side of the valve body 5 is recessed from the downstream side to the upstream side. Then, when the valve body 5 is suspended from the upper end portion 42 of the valve tube 4, it passes above the position at a height of half the height of the valve body 5 in the vertical direction and passes through the swing shaft 53 of the valve body 5. It has a buoyancy generating portion 54 smaller than the specific gravity of water arranged on the upstream side of the vertical plane. It is not necessary that all of the buoyancy generating unit 54 is arranged in the above-mentioned region of the valve body 5, and if a part of the buoyancy generating unit 54 is arranged in the above-mentioned region of the valve body 5. Good.

As described above, in the check valve 2 of the present embodiment, the surface 51 on the downstream side of the valve body 5 is curved so as to be recessed from the downstream side to the upstream side, so that the valve body 5 is the surface on the upstream side. A greater resistance force is generated to the reverse flow drainage flow received on the downstream surface 51 than the forward flow drainage flow received at 52. Therefore, the valve body 5 operates so as to surely close the open end (face) 41 of the valve pipe 4 against the flow of the drainage flowing back from the outlet 12 of the drainage pipe 1 to the invert portion 13, and the valve body. Due to the difference in resistance between the front and back surfaces 51 and 52 of No. 5, it is also prevented from malfunctioning so as to open the open end (face) 41 of the valve pipe 4.

Further, in the check valve 2 of the present embodiment, the valve body 5 is provided with a buoyancy generating portion 54, and in a normal state in which the valve body 5 is suspended from the valve pipe 4, the center of the buoyancy of the buoyancy generating portion 54. Since the 55 (see FIG. 4) is arranged on the upstream side of the vertical plane passing through the swing shaft 53 of the valve body 5, when the drainage flows back into the drainage 1, the valve body 5 is connected to the valve pipe 4. A moment of rotation that closes the open end (face) 41 comes into play. Therefore, the valve body 5 can more reliably close the open end (face) 41 of the valve pipe 4 with respect to the flow of the drainage flowing back from the outlet 12 of the drainage pipe 1 to the invert portion 13. It is also prevented from malfunctioning so as to open the open end (face) 41 of the valve pipe 4.

Further, since the buoyancy generating portion 54 is arranged above the position at a height of half the height of the valve body 5 in the vertical direction, the drainage flowing back from the outlet 12 of the drainage basin 1 to the invert portion 13 When the water level is less than half the height of the valve body 5, buoyancy is basically not generated in the valve body 5, and the valve body 5 is rotated only when the water level of the drainage exceeds half the height of the valve body 5. An effective buoyancy is generated to move it.

Therefore, when the drainage flowing back into the drainage 1 is at a low water level, the valve body 5 receives a large resistance to the reverse flow of the drainage due to the curved shape of the valve body 5 described above. It operates so as to surely close the opening end (surface) 41 of the valve pipe 4 against the flow of the drainage flowing back from the outlet 12 of the drainage basin 1 to the invert portion 13. On the other hand, when the drainage that has flowed back into the drainage 1 becomes a high water level, a moment that rotates the valve body 5 so as to close the opening end (face) 41 of the valve pipe 4 acts due to the buoyancy. Combined with the effect when the backflow drainage is at a low water level, the valve body 5 ensures that the open end of the valve pipe 4 is against the flow of the backflow drainage from the outlet 12 of the drainage 1 to the invert portion 13. (Surface) Operates so as to close 41.

As described above, the check valve 2 of the present embodiment is suspended from the tip of the valve pipe 4 having the open end surface 41 inclined so as to retreat from the upper part to the lower part toward the upstream side even when the amount of drainage is small. Since the valve body 5 has the opening end (face) 41 open, drainage clogging due to foreign matter or the like does not occur, and the reverse flow of drainage flowing from the outlet 12 of the drainage 1 to the invert portion 13 can be used. Only in response to this, the valve body 5 operates so as to close the open end (face) 41 of the valve tube 4 due to the effect of the recessed shape of the valve body 5 and the buoyancy generating portion 54 provided at a specific position.

As is well shown in FIG. 4, in the present embodiment, the buoyancy generating portion 54 is formed by providing the hollow portion 56 in the valve body 5. Although not shown, the buoyancy generating portion is also formed by making the valve body itself from a resin material having a specific gravity smaller than that of water, or by attaching a resin member smaller than the specific gravity of water to the surface on the upstream side of the valve body. can do.

Explaining the buoyancy generating portion 54 of the present embodiment in detail, the hollow portion 56 forming the buoyancy generating portion 54 is curved so as to be recessed from the downstream side to the upstream side, and the surface on the downstream side of the valve body 5 is formed. By joining the downstream side wall surface portion 51 to be formed and the upstream side wall surface portion 52 that is recessed larger than the downstream side wall surface portion 51 from the downstream side to the upstream side and forms the surface on the upstream side at each peripheral edge portion 57. It is partitioned and formed. When the valve body 5 is composed of the downstream side wall surface portion 51 and the upstream side wall surface portion 52 having different degrees of dents in this way, the peripheral portions 57 of both can be easily joined to a desired position in the valve body 5. The hollow portion 56 can be formed.

Further, in the present embodiment, the valve body 5 itself may be made of a resin material having a specific gravity smaller than that of water to form a second buoyancy generating portion in addition to the hollow portion 56. In this case, even if the hollow portion 56 is destroyed due to damage to the valve body 5, the valve body 5 does not lose a predetermined buoyancy, so that the drainage 1 flows back from the outlet 12 to the invert portion 13. The open end (face) 41 of the valve pipe 4 can be reliably closed with respect to the flow of drainage.

Further, when the valve body 5 is made of a resin material smaller than the specific gravity of water, it is preferable that the specific gravity of the upstream side wall surface portion 52 is smaller than the specific gravity of the downstream side wall surface portion 51. If the above difference is provided between the specific gravity of the upstream side wall surface portion 52 and the specific gravity of the downstream side wall surface portion 51, when the valve body 5 is immersed in the drainage flowing back to the invert 13, the valve body 5 has the downstream side wall surface portion 51. Since a moment is applied to rotate the valve pipe 4 toward the upstream side wall surface portion 52 having a smaller specific gravity so as to close the open end (surface) 41 of the valve pipe 4, it is possible to reliably prevent the backflow of drainage, and the valve body. It is also possible to prevent the 5 from malfunctioning so as to open the open end (face) 41 of the valve pipe 4.

5 shows a side view of the check valve 2 shown in FIG. 4, FIG. 6 shows a front view of the check valve 2 shown in FIGS. 4 and 5, and FIG. 7 shows a front view of the check valve 2. Shows a top view of the check valve 2 shown in FIGS. 4 and 6, and FIG. 8 shows a bottom view of the check valve 2 shown in FIGS. 4 and 7.

As shown in FIGS. 1, 3, 5, and 6, in the check valve 2 of the present embodiment, in order to improve the maintainability, the flange portion 3 is attached to the inner wall surface 16 of the drainage pipe 1. By dividing the 32 into a movable flange 33 that can be detachably attached to the fixed flange 32, the valve pipe 4 attached to the movable flange 33 and the valve body 5 supported by the valve pipe 4 can be integrated and easily integrated. It is designed so that it can be removed from the drainage flange 1.

Therefore, the fixed flange 32 is provided with a handle 34 and a pair of vertically extending groove portions 36 for receiving both end portions 35 of the movable flange 33, and the movable flange 33 fixes both end portions 35 thereof. By inserting it into a pair of grooves 36 of the flange, it can be inserted and removed in the vertical direction.

That is, when the check valve 2 is attached to the drainage 1 in the present embodiment, the movable flange 33 is inserted into the groove portion 36 of the fixed flange from top to bottom via the handle 34, and the movable flange 33 and the fixed flange 32 are formed. The opening 31 may be set so as to communicate with each other. At this time, rubber is provided on the end face of the opening 31 of the movable flange 33 so that water does not leak between the end face of the opening 31 of the movable flange 33 connected to each other and the end face of the guide pipe 6 of the fixed flange 32. Packing made of is arranged.

On the other hand, when the check valve 2 is removed from the drainage 1, the movable flange 33 is pulled out from the groove 36 of the fixed flange upward through the handle 34, and the valve pipe 4 attached to the movable flange 33 and the movable flange 33. And the valve body 5 may be pulled up together from the inspection port 14 of the drainage 1.

Further, the fixed flange 32 has substantially the same inner diameter as the valve pipe 4, and a guide pipe 6 (see FIG. 1) inserted into the inflow port 11 of the drainage pipe 1 is provided on the opposite side of the valve pipe 4. ing. The guide pipe 6 communicates with the valve pipe 4 and forms a part of the inflow port 11 of the drainage pipe 1. Therefore, the fixed flange 32 of the present embodiment is fixed to the inner wall surface 16 of the drainage pipe 1 by inserting the guide pipe 6 into the inflow port (opening of the wall surface) 11 of the drainage pipe 1 while suppressing rattling. be able to.

The drainage basin 1 of the present embodiment has a curved second fixed flange 7 attached to the outer wall surface 17 of the drainage basin 1 and an inner peripheral surface having substantially the same diameter as the outer peripheral surface of the guide pipe 6, and is the second. The inflow side connecting pipe 8 connected to the fixed flange 7 of the above is provided. Therefore, the check valve 2 of the present embodiment inserts the guide pipe 6 of the fixed flange 32 into the inside of the inflow side connecting pipe 8 by inserting the side wall of the drainage pipe 1 and inserts the fixed flange 32 and the second fixed flange. By sandwiching the side wall of the drainage pipe 1 with 7, it can be firmly fixed to the inner wall surface 16 of the drainage pipe 1. Further, the valve pipe 4 detachably attached to the fixed flange 32 via the movable flange 33 and the valve body 5 supported by the valve pipe 4 can be removed from the drainage drainage 1 integrally and easily together with the movable flange 33. it can.

Further, as will be understood with reference to FIG. 1, since the tip portion of the guide pipe 6 inserted into the inside of the inflow side connecting pipe 8 forms a step portion 61 on the inner peripheral surface of the inflow side connecting pipe 8. When an external connection pipe (not shown) is inserted into the inflow side connection pipe 8, it can also function as a stopper that comes into contact with the tip of the external connection pipe, which is convenient.

1 ... Drainage 11 ... Inflow port 12 ... Outlet 13 ... Invert part 14 ... Inspection port 15 ... Rising pipe 16 ... Inner wall surface 17 ... Outer wall surface 2・ ・ ・ ・ Backflow prevention valve 3 ・ ・ ・ ・ Flange 31 ・ ・ ・ Opening 32 ・ ・ ・ Fixed flange 33 ・ ・ ・ Movable flange 34 ・ ・ ・ Handle 35 ・ ・ ・ End 36 ・ ・ ・ Groove 37 ・・ ・ Packing 4 ・ ・ ・ ・ Valve pipe 41 ・ ・ ・ Open end (face)
42 ・ ・ ・ Upper end 5 ・ ・ ・ ・ Valve body 51 ・ ・ ・ Downstream side wall surface (downstream surface)
52 ... Upstream side wall surface (upstream surface)
53 ... Swing shaft (rotating means)
54 ・ ・ ・ Buoyancy generating part 55 ・ ・ ・ Center of buoyancy 56 ・ ・ ・ Hollow part 6 ・ ・ ・ ・ Guide pipe 61 ・ ・ ・ Step part 7 ・ ・ ・ ・ Second flange 8 ・ ・ ・ ・ Inflow side connection tube

Claims (8)

Opened at the inflow port, a check valve for preventing the backflow of drainage to the inflow port, an outflow port, an invert portion connecting the inflow port and the outflow port, and above the invert portion. In the drainage system equipped with an inspection port, the check valve is
With the valve pipe attached to the inner wall surface or the inflow port of the drainage pipe,
It has a valve body swingably pivotally supported at the upper end on the downstream side of the valve tube, and the downstream opening end of the valve tube is from the downstream side to the upstream as it goes from the upper part to the lower part. Drainage characterized by being formed to incline towards the side. The drainage pipe according to claim 1, wherein the valve pipe is attached so as to project inward from the inner wall surface of the drainage pipe at an upper position away from the invert portion. The drainage according to claim 1 or 2, wherein the surface of the valve body on the downstream side is curved so as to be recessed from the downstream side to the upstream side. The check valve has a mounting portion attached to the inner wall surface or inlet of the drainage flange to support the valve body, and the mounting portion is attached to the inner wall surface of the drainage flange. The drainage according to any one of claims 1 to 3, wherein the fixed flange and the valve pipe are connected to each other and the movable flange is detachably attached to the fixed flange. .. The drainage according to claim 4, wherein the fixed flange has a groove portion extending in the vertical direction for accepting both ends of the movable flange so that it can be inserted and removed. The drainage according to claim 4 or 5, wherein the fixing flange has a guide pipe to which the fixing flange is connected and is inserted into the inflow port of the drainage basin. A curved second fixing flange attached to the outer wall surface of the drainage pipe, to which an inflow side connecting pipe having an inner peripheral surface having substantially the same diameter as the outer peripheral surface of the guide pipe is connected, is provided. Is fixed to the inner wall surface of the drainage pipe by inserting the guide pipe into the inside of the inflow side connection pipe and sandwiching the side wall of the drainage pipe between the fixing flange and the second fixing flange. The drainage according to claim 6, characterized in that. The claim is characterized in that the end portion of the guide pipe inserted into the inside of the inflow side connecting pipe functions as a stopper that comes into contact with the end portion of the external connecting pipe inserted into the inside of the inflow side connecting pipe. Drain as described in 7.

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