JP7025518B2 - Check valve - Google Patents

Description

The present invention relates to a drainage backflow prevention valve attached to the inlet of the drainage pipe to prevent the drainage flowing back from the sewer main from flowing back to the indoor drainage facility through the drainage basin, even when the amount of drainage is small. Regarding the backflow prevention valve for drainage, which prevents only the flow of drainage (reverse flow drainage) at the time of 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 foreign matter such as dust in the middle of the drainage pipe is removed and inspected. 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 open 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 foreign matter 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 and has 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 drainage of the reverse flow from flowing back to the drainage pipe on the upstream side.

However, the type of check valve described in Patent Document 3 is normally in a state where the open end of the outlet is opened as described above, and there is a gap between the valve body and the step portion of the inlet. 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 that has flowed back to the drainage gradually rises, the valve body receives the pressure of the drainage from its back surface, and the valve body moves in the direction of opening the outlet more widely. There was a problem that it was not possible to prevent the drainage of the reverse flow from flowing back to the drainage pipe on the upstream side.

Further, in the check valve described in Patent Document 3, it is 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 open and close the valve body. There was also the problem of being.

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 and the like, and only the flow of drainage (reverse flow drainage) at the time of backflow can be reliably prevented. The purpose is to provide.

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 tube for supporting the valve body, the mounting mode thereof, and the like. As a result of diligent studies, the inflow port of the drainage basin is extended inward by extending the valve pipe, which is separated from the invert part of the drainage basin and has an opening end inclined to recede upstream from the top to the bottom. It has been found that it is most effective to suspend a valve body having a special shape having a buoyancy generating portion at a specific position so as to be swingable from the valve tube, and have completed the present invention.

That is, according to the present invention, it is attached to a drainage pipe provided with an inlet, an outlet, an invert portion connecting the inlet and the outlet, and an inspection port opened above the invert portion. It is a check valve to prevent backflow, and has a valve pipe attached to the inner wall surface or the inflow port of the drainage pipe, and a valve body swingably supported at the upper end on the downstream side of the valve pipe. A backflow prevention valve for drainage is provided, characterized in that the downstream opening end 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. ..

More specifically, according to the present invention, a flange portion attached to the inner wall surface of the drainage basin, which has an opening for communicating with the inlet of the drainage basin, and a flange portion which communicates with the opening portion and is supported by the flange portion. The valve tube, the opening end of the valve tube on the downstream side, is formed so as to incline from the downstream side to the upstream side from the upper part to the lower part, and the opening of the valve tube. A valve body swingably pivotally supported at the upper end of the open end in order to open and close the end, and the surface on the downstream side of the valve body is curved so as to be recessed from the downstream side to the upstream side. And, when the valve body is suspended from the upper end portion, the vertical surface is above the position of half the height of the valve body in the vertical direction and passes through the swing axis of the valve body. Provided is a check valve for drainage, characterized by comprising the valve body having a buoyancy generating portion smaller than the specific gravity of water arranged on the upstream side of the water. When the inner wall surface of the drainage pipe is curved, it is preferable that the flange portion is curved.

The check valve of the present invention is provided with a valve tube 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 is swayably suspended at the upper end portion of the valve tube. Can be lowered. Therefore, the check valve of the present invention 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 when the amount of drainage is small. However, there is no clogging of drainage due to foreign matter.

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 go around to the back surface of the valve body before the surface on the downstream side. Therefore, in the present invention, it is prevented that the valve body receives the pressure of the drainage from the back surface and moves in the direction of opening the open end of the valve pipe with respect to the flow of the drainage of the reverse flow.

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 gravity of water is provided on the upstream side of the vertical plane passing through the moving axis. 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 surface 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 is applied. Therefore, the valve body can more reliably close the open end of the valve tube against the backflow of drainage, and is prevented from malfunctioning so as to open the open end of the valve tube.

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, buoyancy is basically not 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 against 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 has flowed back into the drainage basin reaches a high water level, the buoyancy exerts a moment on the valve body that rotates it so as to close the opening end of the valve pipe. Combined with the effect at a certain time, it works to close the opening end of the valve pipe more reliably against the flow of drainage flowing into the invert part of the drainage drainage that flows backward.

As described above, the check valve of the present invention has a synergistic effect of a special valve tube shape and a special valve body structure, so that even when the amount of drainage is small, the drainage is not clogged by foreign matter and the like, and the drainage of the reverse flow is discharged. Only the flow (backflow) can be reliably prevented.

In the present invention, the buoyancy generating portion can be configured, 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. Therefore, it is preferable to partition and form. 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 any 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 portion. Since the moment that rotates toward the surface so as to close the open end of the valve tube works, it is possible to surely prevent the backflow of drainage, and the valve body mistakenly opens the open end of the valve tube. It can also be prevented from operating. Further, if the specific gravity of the upstream side wall surface portion is set to be smaller than at least 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 breakage of 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 valve pipes and valve bodies. 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.

In addition, when the flange is divided into a fixed flange attached to the inner wall surface of the drainage basin and a movable flange, the fixed flange has a guide pipe inserted into the inflow port of the drainage basin 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 guide pipe can be inserted into the inflow port of the drainage pipe, so that the fixed flange can be fixed to the inner wall surface of the drainage pipe with less rattling. 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. It is also possible to firmly fix the fixing flange to the inner wall surface of the drainage 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 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 has a stepped portion. It can also function as a stopper that comes into contact with the end, which is convenient.

According to the check valve of the present invention, due to the synergistic effect of the special valve pipe shape and the special valve body structure, even when the amount of drainage is small, the drainage is not clogged by foreign matter, etc. It is possible to operate so as to surely close the open end of the valve pipe against the flow of the reverse flow drainage flowing into the portion, and at the same time, the valve body malfunctions so as to open the open end of the valve pipe. Can be reliably prevented.

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

Hereinafter, the check valve for drainage according to the embodiment of the present invention 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 to which the check valve 2 of the present invention 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 portion 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 pivotally 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 equipped with a valve body 5.

The valve pipe 4 has an open end (face) 41 inclined so as to recede upstream from the upper part to the lower part, and the upper end portion 42 of the valve pipe 4 has a valve body 5 having a special shape. Is suspended so that it can swing freely. 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 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 drainage (reverse flow drainage) flow at the time of backflow, and the valve is valved. It is prevented from moving in the direction of opening the open end (face) 41 of the tube 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 drained from the inner wall surface 16 of the drainage 1. In this aspect, a vertical 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 is 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 portion 54 is arranged in the above-mentioned region of the valve body 5, and if a part of the buoyancy generating portion 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 has a surface on the upstream side. A larger resistance force is generated to the reverse flow drainage flow received at the surface 51 on the downstream side 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 generated between the front and back surfaces 51 and 52 of 5, it is also prevented from malfunctioning so as to open the open end (face) 41 of the valve tube 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 where the valve body 5 is suspended from the valve pipe 4, the center of the buoyancy of the buoyancy generating portion 54. Since 55 (see FIG. 4) is arranged on the upstream side of the vertical surface passing through the swing shaft 53 of the valve body 5, when the drainage flows back into the drainage 1, the valve body 5 has 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 against 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 generation 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 stack 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 when the water level of the drainage exceeds half the height of the valve body 5, the valve body 5 is turned only. 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 open end (face) 41 of the valve pipe 4 against the flow of the drainage flowing back from the outlet 12 of the drainage 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, the buoyancy causes a moment to rotate the valve body 5 so as to close the open end (face) 41 of the valve pipe 4. Coupled 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 drainage backflow 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 on the other hand, the concave shape of the valve body 5 and the effect of the buoyancy generating portion 54 provided at a specific position operate so as to close the open end (face) 41 of the valve tube 4.

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 formed by making the valve body itself from a resin material smaller than the specific gravity 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 smaller than the specific gravity 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 is backflowed from the outlet 12 to the invert portion 13. The open end (face) 41 of the valve pipe 4 can be reliably closed against 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. When 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 so as to close the open end (face) 41 toward the upstream side wall surface portion 52 having a smaller specific gravity, 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 tube 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 surface of the opening 31 of the movable flange 33 so that water leakage does not occur between the end surface of the opening 31 of the movable flange 33 connected to each other and the end surface 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 portion 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 is pulled out. 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 vessel 1 by inserting the guide pipe 6 into the inflow port (opening of the wall surface) 11 of the drainage vessel 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 a diameter substantially the same as the outer peripheral surface of the guide pipe 6 and a 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 into the fixed flange 32 and the second fixed flange. By sandwiching the side wall of the drainage basin 1 with the drainage basin 1, it can be firmly fixed to the inner wall surface 16 of the drainage basin 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 integrally and easily removed from the drainage 1 together with the movable flange 33. 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 51 ... Downstream side wall surface (downstream surface)
52 ... upstream side wall surface (upstream surface)
53 ... Swing shaft (rotating means)
54 ... Buoyancy generating part 55 ... Buoyancy center 56 ... Hollow part 6 ... Guide pipe 61 ... Step part 7 ... Second flange 8 ... Inflow side connection tube

Claims (7)

A check valve attached to a drainage system having an inlet, an outlet, an invert portion connecting the inlet and the outlet, and an inspection port opened above the invert portion.
A valve pipe attached to the inner wall surface or inlet of the drainage pipe,
It has a valve body swingably pivotally supported at the downstream upper end of the valve tube, and the downstream opening end of the valve tube is downstream to upstream as it goes from top to bottom. A check valve for drainage, which is characterized by being formed so as to incline toward the side. The drainage according to claim 1, wherein the opening end opens at an upper position away from the invert portion connected to the inlet of the drainage basin when the valve pipe is attached to the drainage basin. Backflow prevention valve for Masu. The check valve for 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. 1 Backflow prevention valve for drainage described in the section. 4. The flange portion is characterized by comprising a fixed flange attached to the inner wall surface of the drainage pipe and a movable flange to which the valve pipe is connected and detachably attached to the fixed flange. Backflow prevention valve for drainage described in. The check valve for drainage according to claim 5, wherein the fixed flange has a groove portion extending in a vertically direction for accepting both ends of the movable flange so as to be removable. The backflow prevention for drainage according to claim 5 or 6, wherein the fixed flange has a guide pipe connected to the fixed flange and inserted into the inlet of the drainage basin. valve.

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