Backflow prevention fitting

Abstract

To provide a backflow prevention fitting capable of being installed in the middle or end of drainage pipes in a home, and the like, and capable of efficiently preventing backflow in multiple drainage pipes in the home and the like by installing the minimum number of units required, and furthermore, capable of easily performing maintenance inside the joint even in narrow spaces.MEANS FOR SOLVING THE PROBLEM: The backflow prevention fitting includes: a cylindrical fitting body that has an inlet, an outlet, a channel portion connecting the inlet and the outlet, and an inspection port located between the inlet and the outlet and facing the flow path; a lid that can be removably attached to the inspection port; and a valve seat formed on the inner peripheral surface of the fitting body. In the backflow prevention fitting, the valve body is rotatably placed in contact with the upper part of the valve seat, and the central axis of the outlet is arranged at an angle to the central axis of the inlet.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an inclined backflow prevention joint that can be attached to the middle or end of an inclined or upright drainage pipe, and in particular to an inclined backflow prevention joint that can be easily attached to either a drainage pipe with a slope or a drainage pipe arranged vertically by arranging the central axis of the outlet at an incline relative to the central axis of the inlet and arranging the flow path section at an incline relative to the central axis of the inspection hatch. [Background technology]

[0002] Generally, wastewater discharged from drainage facilities such as toilets, bathrooms, and kitchens in houses is collected in a drainage manhole installed on the housing estate via drainage pipes connected to each drainage facility, and the wastewater collected in the drainage manhole is then discharged into the main sewer pipe via a public manhole or manhole.

[0003] In addition, in order to prevent backflow water generated in downstream drainage equipment such as the sewer main pipe from entering the home, backflow prevention devices have been developed that are attached to drainage manholes, etc., as described in Patent Publication No. 2020-153508 (Patent Document 1), and backflow prevention valves that are attached to the middle or end of drainage pipes, etc., as described in Patent Publication No. 2021-169701 (Patent Document 2) and Patent Publication No. 2002-294780 (Patent Document 3).

[0004] On the other hand, due to the recent frequent occurrence of abnormal weather caused by global warming, etc., there are frequent cases where a large amount of rainwater flows into the main sewer pipe in a short period of time, and there is an increasing need to install backflow prevention devices not only in catch basins, but also in upstream drainage pipes inside homes. In addition, drainage pipes inside homes usually have a smaller diameter than downstream drainage pipes, and are prone to clogging with sludge, garbage, etc., so it is also necessary to address this problem.

[0005] For this reason, drainage traps (backflow prevention devices) equipped with inspection hatches have been developed, as described in JP 2010-275763 A (Patent Document 4), for example, so that backflow prevention devices attached to drainage pipes inside the home can be inspected, cleaned, and otherwise maintained.

[0006] However, the backflow prevention devices described in the above Patent Documents 1 to 4 are horizontal type backflow prevention devices that are assumed to be installed horizontally (sideways) on drainage pipes that are arranged approximately horizontally. For this reason, in the case of a multi-story building such as a two- or three-story individual house or apartment building, for example, a horizontal type backflow prevention device must be installed on each of the drainage pipes that are arranged approximately horizontally on each floor (see Fig. 3 in Patent Document 3), which makes the layout of the drainage pipes extremely complicated and increases the likelihood of problems such as clogging.

[0007] Furthermore, although the drain trap described in Patent Document 4 is provided with an inspection hatch for maintenance, the valve body is supported by a mounting seat provided inside the drain trap, making the internal structure extremely complex, and therefore, even if the cap member (inspection cover) is removed, it is actually difficult to easily inspect or clean the inside of the drain trap. In particular, for drain pipes inside homes, the above problem is particularly pronounced because they are installed in small spaces such as under the floors of buildings. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2020-153508 A [Patent Document 2] Patent Publication No. 2021-169701 [Patent Document 3] JP 2002-294780 A [Patent Document 4] JP 2010-275763 A Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, the present invention aims to provide a backflow prevention fitting that can be attached to the middle or end of a drainage pipe inside a home, etc., and that can efficiently prevent backflow in multiple drainage pipes inside a home, etc. with the minimum number of fittings required, and that can easily perform maintenance such as inspection and cleaning of the inside of the fitting even in a small space inside a home, etc. [Means for solving the problem]

[0010] The inventors of the present invention have conducted extensive research into the layout characteristics of drainage pipes and the internal structure of backflow prevention joints in a house. As a result, it has been found that, in general, multiple drainage pipes installed in a building are combined into one drainage pipe (collecting pipe) before passing through the foundation of the building, and then the drainage pipe penetrates the foundation while providing a gradient and is installed outside the building (see FIG. 3 of Patent Document 3). It has also been found that in the case of a multi-story building, the drainage pipes installed on each floor are often combined into a vertical pipe (collecting pipe) of the building, and then installed underground through the vertical pipe. For this reason, if a backflow prevention joint can be installed in the middle or at the end of a drainage pipe with a gradient in a house or a drainage pipe arranged vertically in a building, it is possible to prevent backflow of drainage water by the gradient of the drainage pipe rising diagonally upward or vertically, and further, when backflow of drainage water occurs upstream, it is possible to prevent backflow by the backflow prevention joint, and it has been found that a minimum number of backflow prevention joints are required to efficiently prevent backflow of multiple drainage pipes in a house, etc. First The present invention has been completed to solve the problem.

[0011] On the other hand, it was discovered that by supporting the parts inside the joint, such as the valve body, on the cover of the inspection hatch, it would be possible to easily attach and detach the internal parts, and by simplifying the inside of the joint after the inspection hatch is opened, it would be possible to easily maintain the inside of the joint even in a small space. other The present invention has been completed by solving one of the problems.

[0012] That is, according to the present invention, a cylindrical joint body having an inlet, an outlet, a flow path portion connecting the inlet and the outlet, and an inspection port disposed at a position facing the flow path portion between the inlet and the outlet, A cover that can be detachably attached to the inspection hatch; A backflow prevention joint having a valve seat portion formed on an inner circumferential surface of a joint body, The valve disc is rotatably disposed at a position where it contacts the upper part of the valve seat, The backflow prevention joint is characterized in that the central axis of the outflow outlet is disposed at an incline with respect to the central axis of the inflow inlet. In addition, in the backflow prevention joint of the present invention, the flow path portion or the bottom surface portion of the flow path portion may be disposed at an incline with respect to the central axis of the inspection hatch.

[0013] Therefore, the backflow prevention joint of the present invention can be arranged so that the flow path of the joint body is diagonally or vertically, and as a result, it can be attached to drainage pipes that have a slope or are arranged vertically. In particular, the backflow prevention joint of the present invention can be attached to the middle or end of a collector pipe that has a slope that penetrates the foundation of a building or a collector pipe that is arranged vertically in a multi-story building, so that it can efficiently prevent backflow in multiple drainage pipes inside a house, etc., with the minimum number of attachments required.

[0014] In the backflow prevention joint of the present invention, the flow path portion of the joint body is arranged in an oblique or vertical direction, so that under normal circumstances the check valve (valve body) is in an open state (suspended state) due to its own weight, and it is preferable that the valve seat portion is arranged on the inner surface of the joint body at an angle to the central axis of the inspection hatch so that the check valve can be easily closed by backflow water in the event of an abnormality.

[0015] In the backflow prevention joint of the present invention, the flow path of the joint body is arranged in an oblique or vertical direction, so that backflow water does not flow back in a substantially horizontal direction from downstream to upstream, but rather flows back upward from bottom to top within the joint body. Therefore, in order to ensure that the valve body (check valve) closes reliably even against the backflow water flow that rises from bottom to top, which is unique to backflow prevention joints arranged in an oblique or vertical direction, it is preferable to provide the valve body with a rotation trigger means that rotates the valve body toward the valve seat side due to the rise of backflow water within the joint body.

[0016] The pivot trigger means may be, for example, an inclined portion formed in the lower region of the valve body, and the inclined portion may be configured as an inclined surface formed so as to incline from a vertical plane passing through the rotation axis of the valve body toward the valve seat portion as it moves away from the rotation axis of the valve body under normal conditions. The inclined portion may also be connected to a portion of the valve body other than the inclined portion in a bendable manner.

[0017] If the inclined portion is positioned so that it is inclined from a vertical plane passing through the rotation axis of the valve body toward the valve seat, backflow water rising from bottom to top will collide diagonally with the inclined portion, generating a force that rotates the valve body toward the valve seat.

[0018] In addition, the rotation trigger means can be configured as a buoyancy generating part with a specific gravity smaller than that of water attached to the valve body, and under normal conditions, the buoyancy generating part can be positioned closer to the valve seat than a vertical plane passing through the rotation axis of the valve body.

[0019] If the buoyancy generating part is positioned eccentrically toward the valve seat side relative to the vertical plane passing through the rotation axis of the valve body, the backflow of water rising from bottom to top can raise the buoyancy generating part as if it were pulling up the valve body, in other words, rotating the valve body toward the valve seat side.

[0020] In the backflow prevention joint of the present invention, the valve body may be rotatably supported on the lid portion.

[0021] In the backflow prevention fitting of the present invention, when the valve body is attached to the lid of the inspection hatch, the valve body can be removed by removing the lid, and after the valve body is removed, the inside of the fitting can be left in a substantially hollow state with no walls or other parts that form unevenness, making it easy to perform maintenance such as inspection and cleaning of the inside of the fitting even in a small space.

[0022] In addition, if the valve is attached to the lid, and the lid becomes detached from the inspection hatch for some reason, the valve will come off with it, making it impossible to prevent backflow. For this reason, the backflow prevention joint of the present invention preferably has a locking means to prevent the lid from becoming detached from the inspection hatch due to an increase in water or air pressure inside the joint body.

[0023] It is also preferable that the lid portion is composed of a lid portion main body for opening and closing the inspection hatch and a cap portion for supporting the valve body, and it is more preferable that the lid portion main body is rotatable circumferentially relative to the cap portion.

[0024] When the lid is composed of a lid body and a cap as described above, in order to make it easy to set the valve body in the specified position, it is preferable to provide a first fitting portion on the inner peripheral surface of the inspection hatch that supports the cap from below so that it cannot rotate in the circumferential direction, and to provide a second fitting portion on the cap that fits with the first fitting portion. In this case, it is preferable that the locking means is a bayonet mechanism that prevents the lid from coming off the inspection hatch by rotating the lid body in the circumferential direction relative to the inspection hatch.

[0025] If the locking means of the lid portion is a bayonet mechanism, not only can the lid portion be easily prevented from coming off the inspection hatch by coordinating the lid portion main body with the inspection hatch, but the second fitting portion of the cap portion can be clamped between the lid portion main body and the first fitting portion of the inspection hatch without causing rattling or rotation, so that the valve body supported by the cap portion can be set accurately in a predetermined position and accurately abutted against the valve seat portion. Effect of the Invention

[0026] According to the present invention, a cylindrical joint body having an inlet, an outlet, a flow path portion connecting the inlet and the outlet, and an inspection port arranged at a position facing the flow path portion between the inlet and the outlet, A cover that can be detachably attached to the inspection hatch; A backflow prevention joint having a valve seat portion formed on an inner circumferential surface of a joint body, The valve disc is rotatably disposed at a position where it contacts the upper part of the valve seat, The backflow prevention joint is characterized in that the central axis of the outflow outlet is arranged at an angle to the central axis of the inflow inlet. In addition, in the backflow prevention joint of the present invention, the flow path portion may be arranged at an angle to the central axis of the access hatch.

[0027] Therefore, in the present invention, the flow path of the joint body can be arranged in an oblique or vertical direction, and as a result, it can be attached to drainage pipes that have a slope or are arranged vertically. In particular, the backflow prevention joint of the present invention can be attached to the middle or end of a collector pipe with a slope that penetrates the foundation of a building or a collector pipe arranged vertically in a multi-story building, so that not only can the backflow of drainage water be prevented by the slope of the drainage pipe that rises obliquely upward or vertically, but also, when backflow of drainage water to the upstream side occurs, the backflow can be prevented by the backflow prevention joint, and the backflow of multiple drainage pipes in a house, etc. can be efficiently prevented with the minimum number of installations required.

[0028] Furthermore, according to the present invention, it is possible to provide a backflow prevention joint in which the valve body is rotatably supported in the lid portion.

[0029] In the present invention, when the valve body is attached to the lid of the inspection hatch as described above, the valve body can be removed by removing the lid, and the inside of the fitting after the valve body is removed can be made substantially hollow with no other parts that form walls or unevenness, making it easy to perform maintenance such as inspection and cleaning of the inside of the fitting even in a small space.

[0030] In addition, the lid portion can be configured separately from a lid portion main body for opening and closing the inspection hatch and a cap portion for supporting the valve body, and the lid portion main body can be made circumferentially rotatable relative to the cap portion.

[0031] In this case, a first fitting portion is provided on the inner surface of the inspection hatch which supports the cap portion from below to prevent it from rotating circumferentially, and a second fitting portion which fits with the first fitting portion is provided on the cap portion.By doing so, the second fitting portion of the cap portion can be clamped between the lid body and the first fitting portion of the inspection hatch without any rattling or rotation, so that the valve body supported by the cap portion can be set accurately in a predetermined position and accurately abutted against the valve seat portion. [Brief description of the drawings]

[0032] [Figure 1] 1 is a perspective view showing an entire backflow prevention joint according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a side view of the backflow prevention fitting shown in FIG. 1. [Diagram 3] FIG. 2 is a front view of the backflow prevention joint shown in FIG. 1. [Figure 4] FIG. 2 is a plan view of the backflow prevention joint shown in FIG. 1. [Diagram 5] 5 is a cross-sectional view of the backflow prevention joint shown in FIG. 4 taken along the line AA. [Figure 6] 1 is a perspective view showing an entire cover and valve body of a backflow prevention joint according to a first embodiment of the present invention. FIG. [Figure 7] FIG. 7 is a front view of the lid and the valve body shown in FIG. 6. [Figure 8] FIG. 7 is a side view of the lid and the valve body shown in FIG. 6. [Figure 9] FIG. 7 is an exploded view of the lid and the valve body shown in FIG. [Figure 10] 10 is a perspective view showing the entire cover and valve body of a backflow prevention joint according to a second embodiment of the present invention. FIG. [Figure 11] 11 is a front view of the lid and the valve body shown in FIG. 10. FIG. [Figure 12]FIG. 11 is a side view of the lid and valve body shown in FIG. [Figure 13] 1 is a cross-sectional view showing a state in which the backflow prevention joint according to the first embodiment is connected to an external drain pipe arranged in an oblique direction. [Figure 14] 1 is a cross-sectional view showing a state in which the backflow prevention joint according to the first embodiment is connected to an external drain pipe arranged in a vertical direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, a backflow prevention joint according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the following examples, and various modifications are possible within the scope of the technical concept of the present invention.

[0034] [First embodiment] <Coupling body> Fig. 1 shows a perspective view of the entire backflow prevention joint 1 according to the first embodiment of the present invention. Fig. 2 shows a side view of the backflow prevention joint 1 shown in Fig. 1, Fig. 3 shows a front view of the backflow prevention joint 1 shown in Fig. 1, and Fig. 4 shows a plan view of the backflow prevention joint 1 shown in Fig. 1. Fig. 5 shows a cross-sectional view of the backflow prevention joint 1 shown in Fig. 4 taken along the line AA.

[0035] As shown in Figures 1 to 4 and 5, the backflow prevention joint 1 of the first embodiment is mainly composed of a substantially cylindrical joint body 2, a cover portion 3, and a valve body 4 (see Figure 5) attached to the cover portion 3. The joint body 2 has an inlet 20, an outlet 21, a flow path portion 22 connecting the inlet 20 and the outlet 21, and an inspection port 23 arranged at a position facing the flow path portion 22 between the inlet 20 and the outlet 21, and is integrally molded. Although polyvinyl chloride resin is used as the material of the joint body 2, there is no particular limitation on the material used, and known materials such as plastics can be mainly used.

[0036] 5, the inlet 20 and the outlet 21 of the joint body 2 have a socket shape, and therefore, steps 200, 210 that function as stoppers when the tip of the connected drain pipe abuts against them are formed inside the inlet 20 and the outlet 21. In addition, in this embodiment, the inlet 20 and the outlet 21 have a socket shape, but the inlet 20 and / or the outlet 21 may have a spigot shape (not shown).

[0037] The inspection hatch 23 of the joint body 2 has a trunk portion 230 that rises upward with approximately the same width as the flow passage portion 22, and a cylindrical receiving portion 231 having an internal step 232 for detachably supporting the lid portion 3 is formed continuously with the upper portion of the trunk portion 230. Therefore, even if the diameter of the receiving portion 231 is different from the width of the flow passage portion 22, the inspection hatch 23 (receiving portion 231) can ensure an opening diameter necessary for inspecting the inside of the joint body 2 regardless of the width of the flow passage portion 22 by expanding or contracting the diameter at the boundary between the receiving portion 231 and the trunk portion 230. Also, a recess 233 is formed on the inner peripheral surface of the inspection hatch 23 as a first fitting portion for supporting the lid portion 3 from below so that it cannot rotate in the circumferential direction (see Figs. 1 to 3).

[0038] The flow passage portion 22 of the joint body 2 has an inner peripheral surface provided with a valve body. 4 When the valve body comes into contact with the 4 In this embodiment, a ceiling portion 25 is provided in the upper half of the inside of the flow passage portion 22 so as to form a ceiling of a part of the elbow pipe bent downward, and the valve seat portion 24 is provided so as to form a substantially circular abutment surface by an end of the ceiling portion 25 and a step portion 240 provided in the lower half of the inner circumferential surface of the flow passage portion 22, continuing from the end of the ceiling portion 25.

[0039] For this reason, in this embodiment, when the flow path section 22 is disposed at an angle (see FIG. 13), it is possible to easily form the valve seat section 24 inclined from the downstream side to the upstream side as it moves from the top to the bottom inside the flow path section 22. Furthermore, when the valve seat section 24 is inclined as described above, the valve element 4, which is suspended by its own weight, normally forms a gap between it and the valve seat section 24, thereby ensuring a smooth flow of forward flow drainage, and only in the event of an abnormality (when the water level rises) does the valve element 4 come into contact with the valve seat section 24, thereby effectively preventing backflow water.

[0040] Furthermore, by providing a ceiling portion 25 inside the flow path portion 22, not only can the wastewater flowing into the fitting from the inlet 20 be smoothly deflected downward, but the shape of the valve body 4 can also be simplified to an approximately circular shape to match the shape of the valve seat portion 24.

[0041] In this embodiment, the ceiling portion 25 is integrally formed as a part of the flow path portion 22 of the joint body 2, but may be configured as a separate, independent part separated from the flow path portion 22. For example, the ceiling portion 25 may be supported by the cover portion 3, and the valve body 4 may be rotatably supported on the upper part of the end portion (valve seat portion 24) of the ceiling portion 25. Although not shown, in this embodiment, it is not necessarily necessary to provide the ceiling portion 25 inside the flow path portion 22, and the valve seat portion (e.g., a step portion) may be provided directly on the inner circumferential surface of the joint body 2 by matching the shape of the valve body to the shape of the valve seat portion.

[0042] In the backflow prevention joint 1 of this embodiment, the central axis b of the outlet 21 is arranged at an incline with respect to the central axis a of the inlet 20. Therefore, if the flow path section 22 of the joint body 2 is arranged at an incline to have a certain gradient, the outlet 21 can be connected to a drain pipe 6 having approximately the same gradient as the gradient of the flow path section 22, and the inlet 20 can be connected to a drain pipe 5 arranged approximately horizontally (see FIG. 13). In addition, the flow path section 22 and the bottom surface section of the flow path section 22 are arranged at an incline with respect to the central axis c of the inspection hatch 23, so that the inspection hatch 23 is arranged approximately horizontally. Unlike conventional horizontal backflow prevention devices, the drainage water inside the joint does not easily overflow even if the lid section 3 is opened, and the inside of the joint body 2 can be easily inspected by removing the lid section 3.

[0043] Furthermore, by arranging the flow path section 22 of the joint body 2 vertically, the outlet 21 can be connected to the drain pipe 6a arranged vertically, and the inlet 20 can be connected to the drain pipe 5a having a certain gradient (see FIG. 14). Furthermore, since the flow path section 22 is arranged at an incline with respect to the central axis c of the inspection hatch 23, the inspection hatch 23 is arranged at an incline at least facing upward, and unlike conventional horizontal backflow prevention devices, the drainage water inside the joint does not easily overflow even when the lid section 3 is opened, and the inside of the joint body 2 can be easily inspected by removing the lid section 3.

[0044] In the backflow prevention joint 1 of this embodiment, the flow path section 22 is disposed at an incline with respect to the central axis c of the inspection hatch 23. For this reason, if the flow path section 22 of the joint body 2 is disposed in an oblique direction to have a certain gradient, the inspection hatch 23 is disposed approximately horizontally (see FIG. 13), and if the flow path section 22 of the joint body 2 is disposed in the vertical direction, the inspection hatch 23 is disposed at an angle facing upward (see FIG. 14), making it easy to attach and detach the cover section 3 and the valve body 4 and to inspect the inside of the joint body 2.

[0045] <Lid> Fig. 6 shows a perspective view of the entire cover 3 and valve body 4 of the backflow prevention joint 1 according to the first embodiment of the present invention. Fig. 7 shows a front view of the cover 3 and valve body 4 shown in Fig. 6, Fig. 8 shows a side view of the cover 3 and valve body 4 shown in Fig. 6, and Fig. 9 shows an exploded view of the cover 3 and valve body 4 shown in Fig. 6. Note that Figs. 6 to 9 show a state in which the valve body 4 is intentionally tilted to facilitate understanding, but in reality, when there is no load, the valve body 4 is suspended in a substantially vertical direction due to its own weight.

[0046] As shown in Figures 5 and 6 to 9, the cover 3 has a thick, generally disk-like shape, and the valve body 4 is rotatably supported on its underside via a support arm 32 extending downward. In addition, a pair of protrusions 300 are formed on the upper surface of the cover 3 for gripping and rotating the cover 3. Although polyvinyl chloride resin is used as the material for both the cover 3 and the valve body 4, there are no particular limitations on the material used, and known materials such as plastics can be used.

[0047] More specifically, as shown in Figure 9, the lid portion 3 has a convex portion 300 formed on its upper surface, and is composed of a lid portion main body 30 for opening and closing the inspection hatch 23, a cap 31 that is fitted into the lower part of the lid portion main body 30, and a support arm 32 that is integrally molded with the cap 31 and extends downward from the underside of the cap 31.

[0048] Further, a cylindrical ring 311 is provided on the upper surface of the cap 31 to make it easier to grip the cap 31, and a pair of legs 310 are provided on the periphery of the lower surface of the cap 31 as second fitting portions arranged at positions facing each other and capable of fitting with the recessed first fitting portion 233 provided on the inner peripheral surface of the above-mentioned inspection hatch 23. That is, in this embodiment, the lid body 30 and the cap 31 are configured as separate and independent parts, and the lid body 30 is rotatable in the circumferential direction relative to the cap portion 31.

[0049] Furthermore, a groove 301 is formed on the side surface (circumferential surface) of the lid body 30, and a packing 33 made of an elastomer material is fitted into the groove 301 to improve the sealing performance with the inspection hatch 23 (see FIG. 5). In this embodiment, the lid 3 is composed of the lid body 30 and the cap 31 with the support arm 32 as separate independent parts, but they may also be molded integrally.

[0050] For this reason, in the backflow prevention joint 1 of this embodiment, when the inspection hatch 23 is closed, first, the pair of legs 310 of the cap 31 are fitted into the pair of recesses 233 provided inside the inspection hatch 23. By fitting the legs 310 into the recesses 233, the cap 31 supporting the valve body 4 is supported from below by the fitting of the recesses 233 and is set so as not to rotate in the circumferential direction. Furthermore, after the cap 31 is set inside the inspection hatch 23, the lid part 3 is placed on the step 232 of the receiving part 231 of the inspection hatch 23, whereby the cap part 31 is sandwiched between the lid part main body 30 and the recesses 233 of the inspection hatch without rattling or rotating, so that the valve body 4 supported by the cap part 31 is set accurately in a predetermined position and can be accurately abutted against the valve seat part 24.

[0051] When opening the inspection hatch 23, the valve body 4 can be easily removed by removing the lid body 30 and the cap 31 from the inspection hatch 23 in the reverse order to the above. If the lid body 30 and the cap 31 are integrally formed, the valve body 4 can be removed together with the lid 3 by removing it from the inspection hatch 23.

[0052] 1, 2, 4, and 6, the backflow prevention joint 1 of this embodiment is provided with a locking means 7 for preventing the lid 3 from being suddenly detached from the inspection hatch 23 due to an increase in water or air pressure in the joint body 2. In this embodiment, the locking means 7 is preferably a bayonet mechanism that prevents the lid 3 from being detached from the inspection hatch by rotating the lid body 30 in a circumferential direction relative to the inspection hatch 23. More specifically, the locking means 7 can be composed of a pair of crank-shaped protrusions 70 provided at opposing positions that are 180° apart on the side surface (circumferential surface) of the lid body 30 of the lid 3, and a pair of crank-shaped cutouts 71 provided at opposing positions that are 180° apart on the receiving portion 231 of the inspection hatch 23.

[0053] Therefore, the lid 3 is easily locked without rotating the cap 31 by rotating the cap 31 to a position where the protrusion 70 and the notch 71 engage after the cap body 30 is set inside the inspection hatch 23 and the cap body 30 is fitted into the receiving portion 231 of the inspection hatch 23, and the cap 31 is held down to prevent rattling and prevented from being accidentally removed from the inspection hatch 23. In the above-mentioned bayonet mechanism, the notch 71 does not have to be a crank-shaped protrusion, and may simply be a rod-shaped protrusion. The locking means 7 does not necessarily have to be a bayonet mechanism, and a known engagement means using a hook or the like that engages the lid 3 from above can be used, especially when the lid body 30 and the cap 31 are integrally formed.

[0054] <Valve body> 5 to 8, in this embodiment, the valve element 4 has a flat disk shape, and is rotatably supported by the support arm 32 of the cover part 3. The valve element 4 is rotatably disposed at a position where it contacts the upper part of the end part of the ceiling part 25 provided inside the flow path part 22, i.e., at a position where it contacts the upper part of the valve seat part 24.

[0055] Although not shown, it is preferable that the fulcrum of the valve disc 4 is provided with a stopper that normally holds the valve disc 4 in a position where it is suspended in the vertical direction (FIG. 5) or in a position tilted from the vertical direction toward the valve seat 24, and at least restricts the valve disc 4 from rotating in a direction away from the valve seat 24. In addition, in an embodiment in which the flow path 22 of the joint body 2 is disposed in the vertical direction, a protrusion such as a stopper that abuts against the surface of the valve disc 4 may be provided inside the flow path 22 in order to normally hold the valve disc 4 in a position tilted from the vertical direction toward the valve seat 24.

[0056] As described above, if a stopper is provided at the fulcrum of the valve disc 4, in the event of an abnormality (when the water level rises), the valve disc cannot rotate from the vertical direction in a direction away from the valve seat 24, making it possible to reliably rotate the valve disc 4 toward the valve seat 24 against backflow water rising from bottom to top. Also, if the valve disc is held in a position tilted from the vertical direction toward the valve seat 24 by the stopper at the fulcrum or a protrusion inside the flow path 22, backflow water rising from bottom to top will collide diagonally against the tilted valve disc 4, making it possible to reliably rotate the valve disc 4 toward the valve seat 24 in this case as well.

[0057] [Second embodiment] <Valve body> In the backflow prevention joint 1a according to the second embodiment of the present invention, the configurations of the joint body and the cover portion other than the valve body 4a and the effects achieved thereby are all the same as the configurations of the joint body 2 and the cover portion 3 of the backflow prevention joint 1 according to the first embodiment described above and the effects achieved thereby, so detailed explanations will be omitted here. Therefore, the reference numerals in the drawings relating to the joint body 2 and the cover portion 3 of the backflow prevention joint 1a are the same as the reference numerals in the drawings relating to the backflow prevention joint 1.

[0058] Fig. 10 shows a perspective view of the entire cover 3 and valve body 4a of the backflow prevention joint 1a according to the second embodiment of the present invention. Fig. 11 shows a front view of the cover 3 and valve body 4a shown in Fig. 10, and Fig. 12 shows a side view of the cover 3 and valve body 4a shown in Fig. 10. Note that Figs. 10 to 12 show a state in which the valve body 4a is intentionally tilted to facilitate understanding, but in reality, when there is no load, the valve body 4a is suspended in a substantially vertical direction due to its own weight.

[0059] In this embodiment, in order to ensure that the valve body 4a (check valve) closes reliably even against the backflow water flow that is unique to backflow prevention fittings arranged in an oblique or vertical direction, where backflow water rises from bottom to top, the valve body 4a is provided with a rotation trigger means 8a that rotates the valve body 4a toward the valve seat portion 24 when backflow water rises within the fitting body 2.

[0060] In this embodiment, the rotating trigger means 8a is configured as an inclined portion 80a formed in the lower region of the valve body 4a by bending the flat disc-shaped valve body 4a in the middle into a "dogleg" shape in a side view (FIG. 12). More specifically, the inclined portion 80a is configured as an inclined surface formed so as to incline from a vertical plane passing through the rotation axis (fulcrum 40a) of the valve body 4a toward the valve seat portion 24 as it moves away from the rotation axis (fulcrum 40a) of the valve body 4a under normal conditions.

[0061] In addition, the inclined portion 80a may be fixedly connected or integrally formed with the portion of the valve body 4a other than the inclined portion 80a (the upper region of the valve body 4a) so as to maintain the entire valve body 4a in a certain "L-shaped" form, or may be connected to the portion other than the inclined portion 80a so as to be bendable (rotatable). When the valve body 4a is bendable as described above, the movable range of the inclined portion 80a with respect to the portion other than the inclined portion 80a is set so that the inclined portion 80a can be bent from a state in which the valve body 4a is opened 180° to form the same plane as the upper region of the valve body 4a (see FIG. 8, for example), to a certain bending angle in which the valve body 4a is bent in a "L-shaped" form (FIG. 12), and it is preferable to restrict the inclined portion 80a so as not to be bent to an angle smaller than the certain bending angle.

[0062] In addition, when the valve body 4a is bent into a "dog-like" shape as described above, the valve body 4a is bent into a dog-like shape. Department When the valve body 4a abuts against the valve seat 24, the valve body 4a has a flat disk shape like the valve body 4 of the first embodiment. Department The shape of the valve seat 24 can be made approximately circular to match the outer shape of the valve body 4a. Department The shape of 24 must also be bent in a dogleg shape to match the dogleg shape of the valve body 4a.

[0063] In this embodiment, the inclined portion 80a does not necessarily have to be an inclined plane, but may be, for example, an inclined surface (not shown) formed in the lower region of the valve body 4a that bulges conically from the downstream side to the upstream side, as long as it is formed so as to incline from a vertical plane passing through the rotation axis (fulcrum 40a) of the valve body 4a toward the valve seat portion 24 as it moves away from the rotation axis (fulcrum 40a) of the valve body 4a under normal conditions.

[0064] In this embodiment, the valve body 4a is provided with the inclined portion 80a as the rotation trigger means 8a of the valve body 4a as described above. 2 By arranging the joints diagonally or vertically, backflow water is prevented from 2 Even if the backflow water rises from bottom to top within the valve, it will collide diagonally against the inclined portion 80a, thereby reliably generating a force that rotates the valve body 4a toward the valve seat portion 24, thereby preventing malfunction of the backflow check valve (valve body 4a).

[0065] Also, although not shown, in this embodiment, the pivoting trigger means 8a can be configured as a buoyancy generating part having a specific gravity smaller than that of water attached to the valve body 4, 4a, and under normal circumstances, the buoyancy generating part can be positioned on the valve seat portion 24 side of the vertical plane passing through the rotation axis (fulcrum 40, 40a) of the valve body 4, 4a.

[0066] If the buoyancy generating portion is positioned eccentrically toward the valve seat portion relative to the vertical plane passing through the rotation axis (fulcrum 40, 40a) of the valve body 4, 4a as described above, the backflow water rising from bottom to top can raise the buoyancy generating portion while rotating the valve body 4, 4a toward the valve seat portion 24.

[0067] [Example of installation of backflow prevention joint] Fig. 13 shows a cross-sectional view of the backflow prevention joint 1 according to the first embodiment connected to drain pipes 5 and 6 arranged at an angle, and Fig. 14 shows a cross-sectional view of the backflow prevention joint 1 according to the first embodiment connected to drain pipes 5a and 6a arranged vertically. Note that even if the backflow prevention joint 1 according to the first embodiment is replaced with the backflow prevention joint 1a according to the second embodiment in Figs. 13 and 14, the connection mode and effect are the same as when the backflow prevention joint 1 according to the first embodiment is used, so detailed description here is omitted.

[0068] As shown in Fig. 13, in this embodiment, a sleeve bend pipe (sheath pipe) 9 in the shape of a pipe that is smoothly bent midway is embedded in a concrete foundation 10 of a building. Inside the sleeve bend pipe 9, as drainage pipes that constitute the downstream drainage pipe 6, from the downstream side, a first receiving socket 60, a flexible pipe 61 connected to the first receiving socket 60 and smoothly bent along the sleeve bend pipe 9, a second receiving socket 60 connected to the flexible pipe 61, and a short straight pipe 62 connected to the second receiving socket 60 and forming an inclined spigot are arranged.

[0069] In the backflow prevention fitting 1 of this embodiment, the central axis b of the outlet 21 is arranged at an angle relative to the central axis a of the inlet 20 (see Figure 5), and by arranging the flow path section 22 of the fitting body 2 at an angle to match the gradient of the straight pipe 62, the outlet 21 can be connected to the downstream drain pipe 6, and the inlet 20 can be connected to the upstream drain pipe 5 arranged approximately horizontally.

[0070] As shown in Fig. 14, in this embodiment, a sleeve bent pipe (sheath pipe) 9a bent at approximately 90° is embedded in a concrete foundation 10a of a building. In the sleeve bent pipe 9a, as drainage pipes constituting the downstream drainage pipe 6a, from the downstream side, a first socket 60a, a flexible pipe 61a that can be connected to the first socket 60a and is bent at approximately 90° along the sleeve bent pipe 9a, a second socket 60a connected to the flexible pipe 61a, and a short straight pipe 62a that is connected to the second socket 60a and forms a vertically standing spigot are arranged.

[0071] In the backflow prevention fitting 1 of this embodiment, the central axis b of the outlet 21 is arranged at an angle relative to the central axis a of the inlet 20 (see Figure 5), and therefore, by arranging the flow path section 22 of the fitting body 2 in a vertical direction in accordance with the orientation of the straight pipe 62, the outlet 21 can be connected to the downstream drain pipe 6a, and the inlet 20 can be connected to the upstream drain pipe 5a which is arranged at an angle.

[0072] As a result of the above, in the backflow prevention fitting 1 of this embodiment, regardless of whether the flow path section 22 of the fitting body 2 is positioned at an angle or vertically, under normal circumstances the valve body 4 (check valve) is in an open state (suspended state) due to its own weight, and in the event of an abnormality, the valve body 4 (check valve) can be operated to reliably close due to the rising and collision of backflowing water.

[0073] In addition, the backflow prevention joint 1 of this embodiment can be installed on both sloped drainage pipes 6 and vertically arranged drainage pipes 6a, so it can be installed, for example, in the middle or at the end of a sloped collector pipe that penetrates the foundation 10 of a building or a collector pipe that is arranged vertically in a multi-story building. Not only can the backflow of wastewater be prevented by the slope of the drainage pipe that rises diagonally upward or vertically, but if backflow of wastewater occurs upstream, the backflow can be prevented by the backflow prevention joint, and backflow in multiple drainage pipes within a home, etc. can be efficiently prevented with the minimum number of installations required.

[0074] Furthermore, in the backflow prevention fitting 1 of this embodiment, the valve body 4 is attached to the cap portion 31 of the lid portion 3, so that if the cap portion 31 is removed, the valve body 4 is also removed.Furthermore, if the valve body 4 is attached to the lid portion 3 which is formed integrally with the lid portion main body 30 and the cap 31, the valve body 4 is also removed if the lid portion 3 is removed.Therefore, after the valve body 4 is removed, the inside of the fitting can be made substantially hollow with no other parts that form walls or unevenness, so that maintenance such as inspection and cleaning of the inside of the fitting can be easily performed even in a small space. [Explanation of symbols]

[0075] 1,1a···Backflow prevention joint 2. Fitting body 20...Inlet 200...Stepped section 21... Outlet 210... Step 22... Flow path section 23... Inspection hatch 230...Torso 231 Receiving part 232... Step 233: First fitting portion (recess) 24...Valve seat 240... Step 25 Ceiling section 3...Lid part 30 Lid body 300...Convex part 301 Groove 31. Cap 310: Second fitting portion (leg portion) 311: Cylindrical ring 32 Support arm 33... Packing 4, 4a... Valve body 40,40a····Fulcrum 5,5a...Upstream drain pipe 6,6a...Downstream drain pipe 60,60a··· Socket 61,61a...Flexible tube 62,62a...Straight pipe 7. Locking means 70...Protrusion 71...Notch 8a... Rotating trigger means 80a...Slope part 9,9a···Sleeve bent pipe (sheath pipe) 10...Basics a,b,c...center axis

Claims

1. a cylindrical joint body having an inlet, an outlet, a flow path portion connecting the inlet and the outlet, a body portion standing upward with approximately the same width as the flow path portion, and an inspection port opening at an upper portion of the body portion and positioned between the inlet and the outlet at a position facing the flow path portion; A cover portion that is detachably attached to the inspection hatch; A valve seat portion formed on an inner peripheral surface of the inlet side of the joint body; and A backflow prevention joint including a valve body rotatably supported on the lid portion above the valve seat, A backflow prevention joint, characterized in that the central axis of the outlet is arranged at an angle to the central axis of the inlet.

2. The backflow prevention joint according to claim 1, characterized in that the flow path portion is arranged at an angle with respect to the central axis of the inspection hatch.

3. 3. A backflow prevention joint as described in claim 1 or 2, characterized in that the valve seat portion is arranged on the inner surface of the joint body at an angle with respect to the central axis of the inspection hatch.

4. A backflow prevention joint as described in any one of claims 1 to 3, characterized in that the valve body has a rotation trigger means for rotating the valve body toward the valve seat portion when backflow water rises within the joint body.

5. The backflow prevention joint described in claim 4, characterized in that the rotation trigger means is an inclined portion formed in the lower region of the valve body, and the inclined portion is formed so that under normal conditions, it inclines from a vertical plane passing through the rotation axis of the valve body toward the valve seat portion as it moves away from the rotation axis of the valve body.

6. 6. The backflow prevention joint according to claim 5, wherein the inclined portion of the valve body is connected to a portion other than the inclined portion in a manner that allows the valve body to be bent.

7. A backflow prevention fitting as described in claim 4, characterized in that the rotation trigger means is a buoyancy generating part attached to the valve body and having a specific gravity lower than that of water, and under normal conditions, the buoyancy generating part is positioned on the valve seat side of a vertical plane passing through the rotation axis of the valve body.

8. The lid portion is composed of a lid portion main body for opening and closing the inspection hatch and a cap portion for supporting the valve body, and The backflow prevention joint according to claim 1, wherein the lid body is rotatable in a circumferential direction relative to the cap portion.

9. A first fitting portion is provided on an inner peripheral surface of the access hole, the first fitting portion supporting the cap portion from below so as not to be rotatable in a circumferential direction, and 9. The backflow prevention joint according to claim 8, wherein the cap portion is provided with a second fitting portion that fits with the first fitting portion.

10. A backflow prevention joint as described in claim 8 or 9, characterized in that it is provided with a locking means for preventing the lid portion from coming off the inspection hatch due to an increase in water or air pressure within the joint body.

11. The backflow prevention joint according to claim 10, characterized in that the locking means is a bayonet mechanism that prevents the lid from coming off the inspection hatch by rotating the lid body circumferentially relative to the inspection hatch.

Images