Back-flow prevention joint and back-flow prevention system equipped with the joint

Abstract

To provide a back-flow prevention joint hard to break, etc. even if a large amount of back-flow water occurs at one time and capable of effectively preventing waste water from flowing outside the system and preventing a back-flow, and a back-flow prevention system equipped with the joint.MEANS FOR SOLVING THE PROBLEM: A back-flow prevention joint to be mounted to an inflow port and / or an outflow port of drainage equipment includes: a base part including an inlet opening and an outlet opening that forms valve seat part; and a valve body including a valve body-side hinge part rotatably supported by a first hinge support part disposed near the outlet opening of the base part, where back-flow water passing means is formed in the base part or the valve body. And a back-flow prevention system includes a catch basin equipped with the joint in an inflow port thereof.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a backflow prevention fitting and a backflow prevention system to which the fitting is attached, and in particular to a backflow prevention fitting and a backflow prevention system to which the fitting is attached that prevent wastewater from backflowing into a home, etc. by coordinating a backflow prevention fitting with a drainage manhole having a lid having a pressure release means for backflow water, and a buffer pipe for limiting the head of backflow water. [Background technology]

[0002] Generally, wastewater discharged from drainage facilities such as toilets in houses is collected into drainage manholes within the housing estate via drainage pipes connected to each drainage facility in order to mitigate sudden changes in the amount of wastewater, or for the purpose of removing foreign objects such as garbage and inspecting the drainage pipes. The wastewater collected in the drainage manhole is then discharged into the main sewer pipe via a public manhole or manhole.

[0003] However, due to abnormal weather conditions in recent years, there have been frequent cases of large amounts of rainwater flowing into the main sewer pipe in a short period of time. When a large amount of rainwater flows into the main sewer pipe in a short period of time, the drainage capacity of the main sewer pipe is exceeded, and the overflowing wastewater backs up through catch basins, etc., causing the backflowing wastewater to flow out of indoor drainage equipment connected to the drain pipe.

[0004] Therefore, in order to prevent wastewater that has backflowed from the main sewer pipe from flowing out of the indoor drainage equipment through a drainage manhole, etc., backflow prevention devices (backflow prevention valves) have been developed, such as those described in Patent Publication No. 2020-153508 (Patent Document 1), and pressure relief piping systems, such as those described in Patent Publication No. 2022-109747 (Patent Document 2), which consist of a piping main body extending from the drainage equipment to the sewer, multiple riser pipes provided in the piping main body, and a pressure release means (pressure release lid of a drainage manhole, etc.) that releases the internal pressure in the piping main body to the outside. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-153508 A [Patent Document 2] Patent Publication No. 2022-109747 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the check valve described in Patent Document 1 is a check valve that directly and completely stops the backflow of wastewater that occurs in a drainage basin or piping. Therefore, if a large amount of backflow water occurs all at once, the drainage pressure cannot be released, resulting in high drainage pressure that can damage the valve body or destroy the check valve itself.

[0007] On the other hand, the backflow piping system described in Patent Document 2 does not directly and completely stop the backflow of wastewater upstream, but indirectly prevents backflow of wastewater upstream by releasing backflow water, wastewater pressure, and internal pressure generated within the main piping body to the outside through pressure relief means such as a pressure relief lid installed on a drainage manhole, etc.

[0008] Therefore, in the exhaust pressure piping system described in Patent Document 2, when a large amount of backflow water occurs at once, the backflow water flows out in large quantities onto the ground through the pressure relief means, and since the backflow water cannot be completely stopped, the backflow of wastewater is allowed to flow back into upstream indoor facilities, etc. Furthermore, the exhaust pressure piping system described in Patent Document 2 has the problem that, depending on the level of backflow water, the drainage pressure and internal pressure cannot be sufficiently released, damaging the pressure relief means or causing the pressure relief lid to blow off, creating a danger.

[0009] Therefore, the present invention aims to provide a backflow prevention valve (backflow prevention fitting) that is less likely to be damaged even if a large amount of backflow water occurs at one time, and to provide a backflow pressure piping system (backflow prevention system) that is less likely to be damaged even if a large amount of backflow water occurs at one time and can effectively prevent wastewater from leaking out of the system and backflow of wastewater upstream. [Means for solving the problem]

[0010] As a result of extensive research into the structure of backflow prevention fittings and the system configuration of backflow prevention systems, the inventors have discovered that the above problems can be solved by providing a gap between the lower end of the valve body and the inner surface of the inlet and / or outlet to which the backflow prevention fitting is attached in order to release drainage pressure, etc. in the backflow prevention fitting, and by arranging the system components such as the backflow prevention fitting, drainage manhole, and drain pipe in the backflow prevention system according to their functions, such as preventing backflow of drainage, releasing drainage pressure, etc., and temporarily storing backflow water, and then organically connecting them, thereby completing the present invention.

[0011] That is, according to the present invention, there is provided a backflow prevention joint that is attached to the inlet and / or outlet of a drainage system, comprising a cylindrical base having an inlet opening and an outlet opening forming a valve seat, and a valve body having a valve body-side hinge portion rotatably supported by a first hinge support portion provided near the outlet opening of the base, and the base or valve body is characterized in that a backflow water passage means is formed in the lower part of the valve body that connects the upstream and downstream sides of the valve body when the valve body abuts the valve seat.

[0012] The backflow water passage means may be, for example, a crescent-shaped notch provided in the lower part of the valve body, and defined by the notch and the inner peripheral surface of the inlet and / or outlet of the drainage equipment to which the backflow prevention joint is attached, or the inner peripheral surface of the base. Alternatively, the backflow water passage means may be, for example, a slit provided in the base, and defined by the slit, the inner peripheral surface of the inlet and / or outlet of the drainage equipment to which the backflow prevention joint is attached, and the edge of the valve body. In this case, the slit may extend from the inlet opening to the outlet opening of the base.

[0013] In the backflow prevention joint of the present invention, even when the valve body is completely closed, a backflow water passage means is formed between the edge of the valve body and the inner peripheral surface of the inlet or outlet of the drainage equipment to which the backflow prevention joint is attached, or the inner peripheral surface of the base, by the crescent-shaped notch on the valve body or the slit on the base. Therefore, although the backflow prevention joint of the present invention cannot completely stop the backflow of wastewater that occurs in the drainage basin or piping, it can release a certain amount of drainage pressure that the valve body etc. receives to the upstream side of the valve body through the backflow water passage means, so that damage to the backflow prevention joint due to pressure can be effectively prevented, and the flow rate of backflow water passing through the backflow water passage means can be controlled, so that the amount of wastewater that flows back upstream can be significantly reduced.

[0014] The backflow prevention fitting of the present invention may further be provided with a floater having a buoyancy generating portion and a floater side hinge portion rotatably supported by a second hinge support portion provided near the outlet opening of the base, in which case one or more valve body side engaging teeth may be provided on the valve body side hinge portion and one or more floater side engaging teeth may be provided on the floater side hinge portion, so that when a downward force is generated on the floater, the downward force causes the floater side engaging teeth to press the valve body side engaging teeth in the direction of opening the valve body.

[0015] In addition, by providing two or more valve body side engagement teeth on the outer periphery of the valve body side hinge part and two or more floater side engagement teeth on the outer periphery of the floater side hinge part, when an upward force is generated on the floater, the upward force causes the floater side engagement teeth to press the valve body side engagement teeth in the direction of closing the valve body.

[0016] In the backflow prevention joint of the present invention, if one or more engagement teeth are provided on the outer periphery of the hinge part on the valve body side and the outer periphery of the hinge part on the floater side, the valve body can be held open under normal circumstances by the weight of the floater, ensuring a smooth forward flow of drainage even when the forward flow drainage is small, and preventing clogging due to foreign matter contained in the drainage in combination with the effect of the slits provided in the base. Also, if two or more engagement teeth are provided on the outer periphery of the hinge part on the valve body side and the outer periphery of the hinge part on the floater side, when the blocked backflow water accumulates downstream of the valve body, the valve body can be reliably operated to the closed state and maintained in that state without malfunction.

[0017] Furthermore, in the backflow prevention joint of the present invention, in order to increase the blocking ability of the valve body when backflow occurs, the outlet opening of the base may be inclined so as to progress from the upstream side to the downstream side as it moves vertically or from top to bottom.

[0018] According to the present invention, there is provided a backflow prevention system in which the first inlet is attached to the above-mentioned backflow prevention joint in a bottomed first catchment tank having a first inlet opening horizontally, a first outlet opening horizontally, and a first overflow port opening upward. It is also preferable that the first overflow port of the first catchment tank is provided with a first lid portion having a first pressure release means for releasing the pressure and / or backflow water in the first catchment tank to the outside, and it is more preferable that the first inlet of the first catchment tank is connected to a first buffer pipe having a bottom at a position higher than the opening level of the first overflow port.

[0019] In the backflow prevention system of the present invention, the backflow prevention joint is attached to the first inlet of the first catch basin, so the backflow water stopped by the backflow prevention joint flows (rises) through the riser pipe of the first catch basin to the first overflow port, but the first lid having the first pressure release means is attached to the first overflow port, so the generation of high drainage pressure in the first catch basin is suppressed. Also, in the backflow prevention system of the present invention, the constant drainage pressure received by the backflow prevention joint itself can be released to the upstream side of the valve body, so damage due to drainage pressure generated by backflow water can be prevented.

[0020] In addition, in the backflow prevention system of the present invention, a first buffer pipe having a bottom at a position higher than the opening level of the first overflow port is provided upstream of the first inlet of the first drainage manhole, so that wastewater that has flowed back to the upstream side of the valve body through the backflow water passing means of the backflow prevention fitting can be temporarily stored in the first buffer pipe, effectively preventing the backflow water from flowing out of the system or flowing back further upstream of the first buffer pipe.

[0021] It is preferable that the backflow prevention system of the present invention further comprises a second catch basin with a bottom, the second catch basin having a second inlet opening horizontally, a second outlet opening horizontally, and a second overflow port opening upward, and the second outlet of the second catch basin is directly or indirectly connected to the first inlet of the first catch basin.

[0022] In the backflow prevention system of the present invention, when the second outlet of the second drainage manhole is connected to the first inlet of the first drainage manhole, the wastewater that flows back to the upstream side of the valve body through the backflow water passing means of the backflow prevention joint of the first drainage manhole can be stored (dispersed) in the second drainage manhole, thereby more effectively preventing backflow water from flowing out of the system than when only the first drainage manhole is provided.

[0023] Specifically, for example, it is possible to increase the opening cross-sectional area of ​​the backflow water passage means of the backflow prevention fitting of the first drainage manhole compared to when the second drainage manhole is not connected.As a result, the drainage pressure caused by backflow water in the first drainage manhole is reduced, thereby protecting the backflow prevention system, and the backflow water flowing into the first overflow port of the first drainage manhole is also reduced.In addition, the backflow water that has passed through the first drainage manhole is stored (dispersed) in the second drainage manhole, thereby more effectively preventing the outflow of backflow water outside the system.

[0024] Furthermore, in order to more effectively prevent backflow water from flowing out of the system, it is preferable to make the flow rate that can be discharged by the second pressure release means greater than the flow rate that can be backflowed by the backflow water passing means of the backflow prevention fitting attached to the first drainage manhole.

[0025] In addition, in the backflow prevention system of the present invention, it is preferable that the second overflow port is equipped with a second lid portion having a second pressure release means for releasing the pressure and / or backflow water in the second drainage manhole to the outside, and it is more preferable that the second inlet of the second drainage manhole is connected to a second buffer pipe having a bottom at a position higher than the opening level of the first overflow port and the opening level of the second overflow port.

[0026] By connecting a second buffer pipe having a bottom at a position higher than the opening level of the first overflow port and the opening level of the second overflow port to the upstream side of the second inlet of the second catchment, it becomes possible to temporarily store the wastewater that has backflowed into the second catchment in the second buffer pipe, so that it is possible to more effectively prevent the backflow water from flowing out of the system or backflowing further upstream of the second buffer pipe. Also, by attaching a second lid part equipped with a second pressure release means to the second overflow port of the second catchment, it is possible to further strengthen the protection of the backflow prevention system by suppressing the increase in wastewater pressure caused by backflow water. Effect of the Invention

[0027] According to the backflow prevention joint of the present invention, even when the valve body is completely closed, the crescent-shaped notch on the valve body or the slit on the base form a backflow water passage means between the edge of the valve body and the inner peripheral surface of the inlet or outlet of the drainage equipment to which the backflow prevention joint is attached, or the inner peripheral surface of the base. Therefore, although the backflow prevention joint of the present invention cannot completely stop the backflow of wastewater that occurs in the drainage basin or piping, it can release a certain amount of drainage pressure that the valve body etc. receives to the upstream side of the valve body through the backflow water passage means, so that it is possible to effectively prevent damage to the backflow prevention joint due to pressure, and since the flow rate of backflow water passing through the backflow water passage means is also controlled, the amount of wastewater that flows back upstream can be significantly reduced.

[0028] According to the backflow prevention system of the present invention, since the backflow prevention joint is attached to the first inlet of the first catch basin, the backflow water stopped by the backflow prevention joint flows (rises) through the riser pipe of the first catch basin to the first overflow port, but since the first lid part having the first pressure release means is attached to the first overflow port, the generation of high drainage pressure in the first catch basin is suppressed. Also, in the backflow prevention system of the present invention, the constant drainage pressure received by the backflow prevention joint itself can be released to the upstream side of the valve body, so damage due to the drainage pressure generated by the backflow water can be prevented.

[0029] In addition, according to the backflow prevention system of the present invention, a first buffer pipe having a bottom at a position higher than the opening level of the first overflow port is connected to the upstream side of the first inlet of the first drainage manhole, so that wastewater that has flowed back to the upstream side of the valve body through the backflow water passing means of the backflow prevention joint can be temporarily stored in the first buffer pipe, effectively preventing the backflow water from flowing out of the system or flowing back further upstream of the first buffer pipe. [Brief description of the drawings]

[0030] [Figure 1] 1 is a perspective view showing an entire backflow prevention joint of the present invention, one of the components used in the backflow prevention system of the present invention. FIG. [Diagram 2] FIG. 2 is a perspective view showing the entire catch basin (partially transparent) to which the backflow prevention joint shown in FIG. 1 is attached. [Diagram 3] 3 is a cross-sectional view taken along line AA of the catch basin fitted with the backflow prevention fitting shown in FIG. 2. [Figure 4] 1 is a schematic diagram showing an entire backflow prevention system according to a first embodiment of the present invention. [Diagram 5] 1 is a vertical cross-sectional view of a lid having a pressure release means attached to a catch basin, among the components used in the backflow prevention system of the present invention. FIG. [Figure 6] FIG. 5 is a schematic diagram showing the entire backflow prevention system according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Hereinafter, a backflow prevention joint according to an embodiment of the present invention and a backflow prevention system to which the joint is attached 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. EXAMPLES

[0032] 1. Backflow prevention fitting <Backflow prevention joint> Fig. 1 shows a perspective view of the entire backflow prevention joint 2 according to this embodiment, which is one of the components used in the backflow prevention system 1, 1a of the present invention. Fig. 2 shows a perspective view of the entire catch basin 5 (partially transparent, riser pipe omitted) to which the backflow prevention joint 2 shown in Fig. 1 is attached, and Fig. 3 shows an AA cross-sectional view of the catch basin 5 to which the backflow prevention joint 2 shown in Fig. 2 is attached.

[0033] As shown in Figure 1, the backflow prevention fitting 2 of this embodiment comprises a cylindrical base 20 having an inlet opening 200, an outlet opening 201 having a valve seat portion 202, and a slit 21 extending along a central axis, a valve body 22 rotatably supported near the outlet opening 201 of the base 20, and a floater 23 having a buoyancy generating portion 232 and rotatably supported on the base 20 in the same manner as the valve body 22.

[0034] In this embodiment, the slit 21 extends from the inlet opening 200 of the base 20 to the outlet opening 201, and when the valve element 22 abuts against the valve seat portion 202, a backflow water passing means 210 that communicates between the upstream side and the downstream side of the valve element 22 is formed in the lower part of the valve element 22. However, the slit 21 does not need to extend from the inlet opening 200 to the outlet opening 201 as long as the backflow water passing means 210 can be formed in the lower part of the valve element 22 when the valve element 22 is closed. In addition, the backflow water passing means 210 formed in the lower part of the valve element 22 may have its flow path cross section enlarged by, for example, cutting out a part of the lower part on the valve element 22 side in a crescent shape.

[0035] Specifically, when the backflow water passing means 210 is formed using a slit 21, it is defined by the slit 21, the inner peripheral surface of the inlet 50 and / or outlet 51 of the drainage equipment to which the backflow prevention fitting 2 is attached, and the edge of the valve body 22. Also, although not shown, when the backflow water passing means is formed using a crescent-shaped notch provided in the lower part of the valve body, it is defined by the notch and the inner peripheral surface of the inlet 50 and / or outlet 51 of the drainage equipment to which the backflow prevention fitting 2 is attached, or the inner peripheral surface of the base 20.

[0036] In this embodiment, even when the valve body 22 is completely closed, the slits 21 provided in the base 20 form a backflow water passage means 210 between the edge of the valve body 22 and the inner peripheral surface of the first inlet 50 of the first drainage manhole 5. Therefore, the backflow prevention joint 2 of this embodiment cannot completely stop the backflow of wastewater generated in the first drainage manhole 5, but the backflow prevention joint 2 can release a certain amount of wastewater pressure received by the backflow prevention joint 2 to the upstream side of the valve body 22 through the backflow water passage means 210, so that damage to the valve body 22, etc. due to pressure can be effectively prevented, and the flow rate of the backflow water passing through the backflow water passage means 210 is also controlled, so that the amount of wastewater flowing back to the upstream side can be significantly reduced.

[0037] In addition, the bottom of the base 20 is flush with the inner surface of the first inlet 50 due to the slits 21 provided in the base 20, eliminating any steps. Therefore, even if the amount of forward flow wastewater is small, foreign matter contained in the wastewater will not accumulate in the steps and cause clogging.

[0038] The floater 23 is configured separately and independently from the valve body 22 so that the gravity generated in the floater 23 and the buoyancy generated in the buoyancy generating section 232 can function efficiently, and the buoyancy generating section 232 is positioned so that it can rotate away from the valve body 22 in a region downstream of the valve body 22 and / or in a region above the valve body 22.

[0039] In this embodiment, the backflow prevention joint 2 is made of polyvinyl chloride resin, but there is no particular limitation on the material used, and known materials such as plastics can be used.

[0040] <Valve body> The backflow prevention joint 2 of this embodiment includes a valve body 22 for opening and closing a valve seat portion 202 formed in an outlet opening 201 of a base portion 20, which will be described later. The valve body 22 is not particularly limited in shape as long as it can abut against and close the valve seat portion 202, and in this embodiment, the downstream surface of the valve body 22 has a shape that is concave from the downstream side to the upstream side (the upstream back surface has a shape that bulges from the downstream side to the upstream side) so as to reliably stop the backflow of wastewater.

[0041] A valve body side hinge portion 220 extending in the radial direction is formed on the upper peripheral edge portion of the valve body 22, and a gear-shaped valve body side engagement tooth 221 consisting of two or more teeth protruding in the radial direction from the outer peripheral surface is formed on the outer periphery of the rotation axis of the valve body side hinge portion 220. The shape and number of the valve body side engagement tooth 221 are not particularly limited, but in this embodiment, one tooth of the valve body side engagement tooth 221 is a convex portion having a smooth triangular cross section, and may be formed from a convex portion and / or a concave portion as long as it forms the teeth of a gear. In addition, the valve body side engagement tooth 221 may be one or two or more as long as the number can engage with the floater side engagement tooth 231 when the floater 23 rises and falls. For example, one floater side engagement tooth 231 is formed on the outer peripheral surface of the floater side hinge portion 230, and two or more valve body side engagement teeth 221 are formed on the outer peripheral surface of the valve body side hinge portion 220 so as to sandwich the floater side engagement tooth 231 from the front and rear.

[0042] <Floater> The backflow prevention joint 2 is provided with a floater 23 to assist the movement of the valve body 22. The floater 23 has a buoyancy generating part 232, and is not particularly limited as long as it generates a force to rotate the valve body 22 in the opening direction by the weight of the buoyancy generating part 232 and has a shape, structure, and material that can generate buoyancy against the weight of the buoyancy generating part 232 in water. In this embodiment, the buoyancy generating part 232 is set so that the rotational moment generated by the weight of the buoyancy generating part 232 on the rotational axis of the floater 23 is larger than the rotational moment generated by the weight of the valve body 22 on the rotational axis of the valve body 22, and the rotational moment due to buoyancy generated in the buoyancy generating part 232 on the rotational axis of the floater 23 is set so that it is larger than the rotational moment generated by the weight of the buoyancy generating part 232.

[0043] In this embodiment, the buoyancy generating part 232 is formed as a hollow plastic structure having a spherical shape, taking into consideration the strength and ease of manufacture, etc. The buoyancy generating part 232 is connected to the floater side hinge part 230 via a round bar-shaped rod 233, and by adjusting the size of the buoyancy generating part 232 and the length of the rod 233, the magnitude of the rotation moment generated on the rotation axis by the buoyancy of the buoyancy generating part 232 can be adjusted.

[0044] In this embodiment, the floater side engagement teeth 231 are formed on the outer periphery of the rotation shaft of the floater side hinge part 230 in a gear shape consisting of two or more teeth protruding in the radial direction from the outer periphery. The shape and number of the floater side engagement teeth 231 are not particularly limited, but in this embodiment, one tooth of the floater side engagement teeth 231 is a convex part having a smooth triangular cross section like the valve body side engagement teeth 221, and may be formed from a convex part and / or a concave part as long as it forms the teeth of a gear. In addition, the floater side engagement teeth 231 may be one or two or more as long as the number of teeth can engage with the valve body side engagement teeth 221 when the floater 23 rises and falls. For example, there may be a case where one valve body side engagement tooth 221 is formed on the outer periphery of the valve body side hinge part 220, and two or more floater side engagement teeth 231 are formed on the outer periphery of the floater side hinge part 230 so as to sandwich the valve body side engagement teeth 221 from the front and rear.

[0045] In this embodiment, by dividing the floater side engagement teeth 231 into first and second rows of floater side engagement teeth and arranging them in a staggered manner, it is possible to make the pitch of the first and second rows of floater side engagement teeth twice the pitch of the valve body side engagement teeth 221, resulting in a structure that makes it difficult for dirt and other debris to adhere or become caught between the first and second rows of floater side engagement teeth.

[0046] Although not shown, the backflow prevention fitting 2 of this embodiment may be configured such that one valve body side engaging tooth is provided on the valve body side hinge portion, and one floater side engaging tooth is provided on the floater side hinge portion, so that only when a downward force is generated on the floater, the floater side engaging tooth presses the valve body side engaging tooth in the direction of opening the valve body due to the downward force.

[0047] <Base> The base 20 has a substantially circular inlet opening 200 for attachment to an inlet or outlet of a drainage basin, pipe or the like, a substantially circular outlet opening 201 that communicates with the inlet opening 200 and forms a valve seat portion 202 that abuts against the valve body 22, and a slit 21 that extends parallel to the central axis.

[0048] In this embodiment, the base 20 is configured as a short straight pipe having a downward C-shaped cross section, but it does not necessarily have to be entirely straight and may include a curved pipe section. The diameter of the base 20 does not necessarily have to be uniform, and as long as it has the slit 21, it may be configured like a differential diameter pipe joint in which the diameters of the inlet opening 200 and the outlet opening 201 are different.

[0049] There are no particular restrictions on the width dimension or cross-sectional shape of slit 21, so long as it connects the upstream and downstream sides of the lower part of valve body 22 when valve body 22 is closed, and can define (form) backflow water passage means 210 by the edge of valve body 22, the inner surface of the inlet or outlet to which backflow prevention fitting 2 is attached, and the inner wall of slit 21.

[0050] In this embodiment, the outlet opening 201 of the base 20 is formed in a vertical direction, but may be inclined so as to advance from the upstream side to the downstream side as it goes from top to bottom (not shown). By forming the outlet opening 201 in the above-mentioned shape, the rotation angle required for the valve body 22 to close the outlet opening 201 can be reduced, and the closure of the outlet opening 201 by the valve body 22 can be improved.

[0051] Provided on the upper portion of the base 20 are a first hinge support portion 203 for rotatably supporting the valve body side hinge portion 220 of the valve body 22, and a second hinge support portion 204 for rotatably supporting the floater side hinge portion 230 of the floater 23. The first and second hinge support portions 203, 204 do not need to be formed separately, and there are no particular limitations on their shapes or numbers, so in this embodiment, the first and second hinge support portions 203, 204 are integrally formed to form a single hinge support portion.

[0052] The first hinge support part 203 is disposed on the side of the valve body side hinge part 220 so that its shaft hole aligns with the shaft hole of the valve body side hinge part 220, and rotatably supports the valve body 22 by inserting a pin through each shaft hole. The second hinge support part 204 is disposed above the first hinge support part 203 on the side of the floater side hinge part 230 so that its shaft hole aligns with the shaft hole of the floater side hinge part 230, and rotatably supports the floater 23 by inserting a pin through each shaft hole.

[0053] The first hinge support part 203 and the second hinge support part 204 may be provided on the base part 20 so as to sandwich the valve body side hinge part 220 and the floater side hinge part 230 from both sides as in this embodiment, or conversely, a pair of valve body side hinge parts and a pair of floater side hinge parts may be provided on the valve body and the floater so as to sandwich the first hinge support part and the second hinge support part provided on the base from both sides. In order to distribute the force acting on the pin as evenly as possible, it is preferable to provide at least two or more of either the valve body side and floater side hinge parts 220, 230 or the first and second hinge support parts 203, 204.

[0054] 2. Backflow prevention system [First embodiment] <Backflow prevention system> FIG. 4 is a schematic diagram showing the overall configuration of a backflow prevention system 1 according to a first embodiment of the present invention.

[0055] 4, the backflow prevention system 1 of the first embodiment is typically installed outdoors, and includes a first drainage manhole 5 connected to a sewer main (not shown) via a drainage pipe 7, and a first buffer pipe 6 connected to the upstream side of the first drainage manhole 5. There are no particular limitations on the piping layout upstream of the first buffer pipe 6, but it is typically connected to an indoor drainage facility 8 via the drainage pipe 7.

[0056] <Drainage Manhole> As shown in Figures 2 and 3, the first drainage manhole 5 has a first inlet 50 that opens horizontally, a first outlet 51 that opens horizontally and is connected via the bottom or an invert, and a first overflow port 53 that opens upward via a first riser pipe 52, and the first inlet 50 is equipped with the above-mentioned backflow prevention fitting 2, and the first lid portion 3 equipped with a first pressure release means 4 is attached to the first overflow port 53.

[0057] In the first embodiment of the backflow prevention system 1, the first drain manhole 5, the first buffer pipe 6, and the backflow prevention fitting 2, first lid portion 3, and first pressure release means 4 attached to the first drain manhole 5 are formed from polyvinyl chloride resin, but there is no particular limitation on the materials used, and known materials such as plastics can be used.

[0058] <Backflow prevention joint> In the backflow prevention system 1 of the first embodiment, the backflow prevention joint 2 attached to the first inlet 50 of the first drainage manhole 5 basically functions to prevent wastewater that has flowed back into the first drainage manhole 5 from flowing further upstream of the first inlet 50. Therefore, the wastewater whose backflow is prevented by the backflow prevention joint 2 flows back (upwards) through the first riser pipe 52 toward the first overflow port 53, and the buoyancy generated in the buoyancy generating section 232 is transmitted to the valve body 22 via the floater side engaging teeth 231 and the valve body side engaging teeth 221 as a force pressing in the direction of closing the outlet opening 201.

[0059] At that time, the upward movement of the floater 23 is not hindered by interference with the inner wall of the first catch basin 5, because the first catch basin 5 has spaces formed by the first riser pipe 52 and the first overflow port 53 above the first inlet 50 and the first outlet 51. In this way, the backflow prevention system 1 of the first embodiment can reliably close the outlet opening 201 without malfunctioning the valve body 22 when backflow water occurs, thereby preventing the backflow of wastewater.

[0060] In addition, under normal circumstances, when a downward force is generated on the floater 23 due to gravity, the downward force rotates and holds the valve body 22 in the direction of opening the outlet opening 201 via the floater side engagement teeth 231 and the valve body side engagement teeth 221.Therefore, in the first embodiment of the backflow prevention system 1, a smooth flow of wastewater is ensured even if the amount of forward flow wastewater is small, and together with the step-eliminating effect of the slits 21 formed in the base 20, clogging due to foreign matter contained in the wastewater can also be prevented.

[0061] <Pressure release means, lid> Figure 5 shows a longitudinal cross-sectional view of a first lid portion 3 having a first pressure release means 4 attached to a first catch basin 5, which is one of the components used in the backflow prevention system 1 of the first embodiment.

[0062] In the first embodiment of the backflow prevention system 1, the first drainage manhole 5 is provided with a first lid portion 3 having a first pressure release means 4 at the first overflow port 53, so that the increase in pressure in the first drainage manhole 5 caused by the drainage water flowing back (upward) toward the first overflow port 53 can be suppressed, and the backflow prevention system 1 is protected.

[0063] The first lid part 3 having the first pressure release means 4 is not particularly limited in structure or shape as long as it can release pressure so that the lid part does not come off from an opening such as a drainage basin when excessive pressure is applied to the lid part, and any lid part equipped with a known pressure release means can be used.

[0064] 5, the first lid 3 having the first pressure release means 4 is mainly composed of a lid frame 31 fitted into the first overflow port 53, and a substantially disk-shaped lid body 30 detachably attached to the lid frame 31. The lid body 30 includes a guide member 300 extending substantially vertically from the rear surface of the lid body 30, and a locking member 301 for restricting the up and down movement of the lid body 30. Meanwhile, the lid frame 31 includes a receiving port 310 for detachably receiving the lid body 30, a skirt portion 311 extending downward from the receiving port 310, and a flange portion 312 provided on the inner peripheral surface of the skirt portion 311 below the receiving port and engageable with a hook of the locking member 301 of the lid body 30.

[0065] When the lid body 30 is attached to the lid frame 31, the guide member 300 is positioned so as to leave a predetermined gap between it and all or part of the inner surface of the skirt portion 311, and the engagement surface of the hook of the locking member 301 of the lid body 30 is positioned so as to be a predetermined height (distance) away from the engagement surface of the flange portion 312 of the lid frame 31.Therefore, the lid body 30 is able to move up and down to a predetermined height (distance) from the receiving port 310 of the lid frame 31, and at this time, a pressure release portion 313 is formed between the outer periphery of the lid body 30 and the receiving port 31, connecting the inside and outside of the lid body 30.

[0066] Therefore, in this embodiment, when the first lid part 3 is locked, the lid main body 30 cannot be removed from the lid frame 31 due to the engagement between the locking member 301 and the flange portion 312. However, when high pressure is generated on the back surface of the lid main body 30, the hook of the locking member 301 is pushed up in response to that pressure until it engages with the flange portion 312 of the lid frame 31, releasing the internal pressure through the pressure release portion 313 formed between the outer periphery of the lid main body 30 and the receiving port 310 (Figure 5(b)), and after the pressure is released, it returns to its original position in the lid frame 31 (Figure 5(a)).

[0067] As such, the first pressure release means 4 in this embodiment is integrated with the first lid portion 3 and is composed of a lid frame 31 having a flange portion 312, and a lid main body 30 having a guide member 300 and a locking member 301, and being movable up and down relative to the lid frame 31.

[0068] <Buffer tube> In the first embodiment of the backflow prevention system 1, as shown in FIG. 4, a first buffer pipe 6 having a bottom 60 at a position higher than the opening level 530 of the first overflow port is connected to the first inlet 50 of the first drainage basin 5.

[0069] More specifically, the first buffer pipe 6 is composed of, from downstream to upstream, a first straight pipe section 61 connected to the first inlet 50 of the first drainage manhole 5 and extending approximately horizontally so as to penetrate the foundation 9 of the building, a first curved pipe section 62 connected to the first straight pipe section 61 and converting a horizontal opening into a vertical opening, a second straight pipe section 63 connected to the first curved pipe section 62 and extending approximately vertically, a second curved pipe section 64 connected to the second straight pipe section 63 and converting a vertical opening into a horizontal opening, and a third straight pipe section 65 connected to the second curved pipe section 64 and extending approximately horizontally so that its bottom 60 is positioned at a position higher than the opening level 530 of the first overflow outlet.

[0070] However, in the first buffer pipe 6, the bottom 60 located at a position higher than the opening level 530 of the first overflow port does not necessarily have to be formed in the straight pipe section, and may be formed, for example, in the middle of the bottom of the first curved pipe section 62 or in the middle of the bottom of the second curved pipe section 64, or the upward opening of the second straight pipe section 63 may be configured to correspond to the bottom 60 of the first buffer pipe 6 and be located at a position higher than the opening level 530 of the first overflow port.

[0071] In the backflow prevention system 1 of the first embodiment, in order to prevent the backflow prevention joint 2 and the like from being destroyed by an increase in pressure caused by backflowing wastewater, a backflow water passage means 210 is provided at the bottom of the valve body 22 to allow a certain amount of drainage pressure and backflow water to escape upstream. However, in the first embodiment, as described above, the first buffer pipe 6 is connected to the upstream side of the first drainage manhole 5, so that the wastewater that has backflowed upstream of the backflow prevention joint 2 is temporarily stored in the first buffer pipe 6, and is prevented from immediately flowing out of the backflow prevention system 1 or from backflowing further upstream of the first buffer pipe 6.

[0072] The first buffer pipe 6 can be made of any commercially available piping made of resin, metal, etc., without any particular limitation. The first buffer pipe 6 may be made of a straight pipe, a curved pipe, a flexible pipe, or a combination of a plurality of pipes, so long as, after being laid out, a part of the bottom 60 of the first buffer pipe 6, more preferably a bottom 60 near the upstream end, is laid out at a position higher than the opening level 530 of the first overflow port.

[0073] As described above, in the backflow prevention system 1 of the first embodiment, when wastewater flows back into the first drainage inlet 5, most of the backflow water is prevented from flowing back upstream by the backflow prevention fitting 2, and the wastewater whose backflow is prevented is temporarily stored in the first drainage inlet 5. In addition, when the wastewater flows back (upward) toward the first overflow port 52, the first pressure release means 4 of the first lid portion 3 attached to the first overflow port 52 suppresses the rise in pressure inside the first drainage inlet 5, thereby protecting the backflow prevention system 1.

[0074] In addition, in order to prevent excessive load from being placed on the backflow prevention joint 2 or the first drainage manhole 5, the wastewater that is released upstream of the backflow prevention joint 2 through the backflow water passing means 210 is temporarily stored in the first buffer pipe 6 or the first drainage manhole 5, thereby preventing it from immediately flowing out of the backflow prevention system 1 or flowing back further upstream of the first buffer pipe 6.

[0075] Furthermore, in the first embodiment of the backflow prevention system 1, the first drainage manhole 5 is equipped with a first pressure release means 4 on the first lid portion 3 attached to the first overflow port 52, so that when the wastewater flows back (upwards) toward the first overflow port 52, the increase in pressure within the first drainage manhole 5 can be suppressed, and the backflow prevention system 1 is protected.

[0076] 2. Backflow prevention system [Second embodiment] <Backflow prevention system> FIG. 6 is a schematic diagram showing the overall configuration of a backflow prevention system 1a according to a second embodiment of the present invention.

[0077] 6, the backflow prevention system 1a of the second embodiment is usually installed outdoors and includes a first drainage inlet 5 connected to a sewer main (not shown) via a drainage pipe 7a, a second drainage inlet 5a connected to the upstream side of the first drainage inlet 5 via the drainage pipe 7a, and a second buffer pipe 6a connected to the upstream side of the second drainage inlet 5a. There are no particular limitations on the piping layout on the upstream side of the second buffer pipe 6a, but it is usually connected to an indoor drainage facility 8a via another drainage pipe 7a.

[0078] In this way, the backflow prevention system 1a of the second embodiment has basically the same system configuration as the backflow prevention system 1 of the first embodiment, except that a second drainage inlet 5a without a backflow prevention joint 2 is connected instead of the first buffer pipe 6 connected to the upstream side of the first drainage inlet 5, and a second buffer pipe 6a is connected to the upstream side of the second drainage inlet 5a. Therefore, in the backflow prevention system 1a of the second embodiment, some of the components having the same configuration as the backflow prevention system 1 of the first embodiment will be described using the same reference numerals as in the first embodiment.

[0079] <Drainage Manhole> The first catch basin 5 used in the second embodiment is the same as the first catch basin 5 used in the first embodiment, and the second catch basin 5a has the same configuration as the first catch basin 5 used in the first embodiment. Therefore, like the first catch basin 5, the second catch basin 5a has a second inlet 50 opening in the horizontal direction, a second outlet 51 opening in the horizontal direction connected via the bottom or invert, and a second overflow port 53a opening upward via a second riser pipe 52, and the second outlet 51 of the second catch basin 5a is connected to the first inlet 50 of the first catch basin 5 via a drain pipe 7a, and a second lid portion 3a having a second pressure release means 4a is attached to the second overflow port 53a (see Figs. 2 and 3).

[0080] In the backflow prevention system 1a of the second embodiment, the first and second drainage manholes 5, 5a, the first and second lid portions 3, 3a, the first and second pressure release means 4, 4a, the drainage pipe 7a, the second buffer pipe 6a and the backflow prevention fitting 2 attached to the first drainage manhole 5 are also formed from polyvinyl chloride resin, but there are no particular limitations on the materials used, and known materials such as plastic can be used.

[0081] <Backflow prevention joint> In the backflow prevention system 1a of the second embodiment, the backflow prevention joint 2 attached to the first drainage manhole 5 and its first inlet 50 has the same configuration as that used in the first embodiment (see FIG. 1). Therefore, the backflow prevention joint 2 functions to prevent wastewater that has flowed back into the first drainage manhole 5 from flowing further upstream of the first inlet 50, as in the first embodiment, and other functions and configurations are also the same as those used in the first embodiment, so a detailed description of the backflow prevention joint 2 will be omitted here.

[0082] <Pressure release means, lid> In the second embodiment of the backflow prevention system 1a, the first drainage manhole 5 is provided with a first lid portion 3 having a first pressure release means 4 at the first overflow port 53, and the second drainage manhole 5a is provided with a second lid portion 3a having a second pressure release means 4a at the second overflow port 53a, so that the increase in pressure in the first and second drainage manholes 5, 5a caused by wastewater flowing back (upward) toward the first and second overflow ports 53, 53a can be suppressed, and the backflow prevention system 1a is protected.

[0083] The second lid part 3a equipped with the second pressure release means 4a attached to the second drainage manhole 5a has the same configuration and function as the first lid part 3 equipped with the first pressure release means 4 attached to the first drainage manhole 5 (see Figure 5), so a detailed explanation of the second pressure release means 4a and the second lid part 3a will be omitted here.

[0084] <Buffer tube> In the second embodiment of the backflow prevention system 1a, as shown in FIG. 6, a second buffer pipe 6a having a bottom 60 at a position higher than the opening level 530 of the first overflow port of the first drainage manhole 5 and the opening level 530a of the second overflow port of the second drainage manhole 5a is connected to the second inlet 50 of the second drainage manhole 5a, and the second buffer pipe 6a basically has the same configuration and function as the first buffer pipe 6.

[0085] More specifically, the second buffer pipe 6a is composed of, from downstream to upstream, a first straight pipe section 61 connected to the second inlet 50 in the same manner as the first drainage manhole 5 and extending approximately horizontally so as to penetrate the foundation 9a of the building, a first curved pipe section 62 connected to the first straight pipe section 61 and converting the horizontal opening into a vertical opening, a second straight pipe section 63 connected to the first curved pipe section 62 and extending approximately vertically, a second curved pipe section 64 connected to the second straight pipe section 63 and converting the vertical opening into a horizontal opening, and a third straight pipe section 65 connected to the second curved pipe section 64 and extending approximately horizontally so that its bottom 60 is positioned at a position higher than the opening level 530 of the first overflow port of the first drainage manhole 5 and the opening level 530a of the second overflow port of the second drainage manhole 5a.

[0086] However, in the second buffer pipe 6a, the bottom 60 located at a position higher than the opening levels 530, 530a of the first and second overflow ports does not necessarily have to be formed in the straight pipe section, and may be formed, for example, in the middle of the bottom of the first curved pipe section 62 or in the middle of the bottom of the second curved pipe section 64, or the upward opening of the second straight pipe section 63 may correspond to the bottom 60 of the second buffer pipe 6a and be configured to be located at a position higher than the opening level 530 of the first overflow port of the first drainage manhole 5 and the opening level 530a of the overflow port of the second drainage manhole 5a.

[0087] In the second embodiment of the backflow prevention system 1a, a second buffer pipe 6a is connected upstream of the second drainage manhole 5a, so that wastewater that passes through the backflow prevention fitting 2 attached to the first drainage manhole 5 and flows back upstream is temporarily stored in the second buffer pipe 6a, preventing it from immediately flowing out of the backflow prevention system 1a or flowing back further upstream of the second buffer pipe 6a.

[0088] In the backflow prevention system 1a of the second embodiment, in order to more effectively prevent backflow water from flowing out of the system, the flow rate Q that can be discharged by the second pressure release means 4a is set to 1000 s. 1(l / min) is the flow rate Q that can be backflowed by the backflow water passage means 210 of the backflow prevention joint 2 attached to the first drainage inlet 5. 2 It is preferable to set the flow rate to be greater than 1 / min.

[0089] As described above, in the backflow prevention system 1a of the second embodiment, when wastewater flows back into the first drainage inlet 5, most of the backflow water is prevented from flowing back upstream by the backflow prevention fitting 2, and the wastewater whose backflow is prevented is temporarily stored in the first drainage inlet 5. In addition, when the wastewater flows back (upward) toward the first overflow port 53, the first pressure release means 4 of the first lid portion 3 attached to the first overflow port 53 suppresses the rise in pressure inside the first drainage inlet 5, thereby protecting the backflow prevention system 1a.

[0090] In addition, the wastewater that is released to the upstream side of the backflow prevention joint 2 through the backflow water passing means 210 so as not to place an excessive load on the backflow prevention joint 2 or the first drainage inlet 5 will temporarily backflow into the second drainage inlet 5a. However, in the backflow prevention system 1a of the second embodiment, the second buffer pipe 6a, whose bottom 60 is located at a position higher than the opening level 530 of the first overflow port of the first drainage inlet 5 and the opening level 530a of the second overflow port of the second drainage inlet 5a, is connected to the upstream side of the second drainage inlet 5a, so that the wastewater that attempts to backflow further upstream than the second drainage inlet 5a is temporarily stored in the second buffer pipe 6a or the drainage inlet 5a, and is prevented from immediately flowing out of the backflow prevention system 1a or from backflowing further upstream of the second buffer pipe 6a.

[0091] Furthermore, in the second embodiment of the backflow prevention system 1a, the second drainage manhole 5a is equipped with a second pressure release means 4a on the second lid portion 3a attached to the second overflow port 53a, so that when the wastewater flows back (upwards) toward the second overflow port 53a, the increase in pressure in the second drainage manhole 5a is suppressed, and the backflow prevention system 1a is protected. [Explanation of symbols]

[0092] 1,1a Backflow prevention system 2. Backflow prevention joint 20...Base 200....Inlet opening 201...Exit opening 202 Valve seat part 203... First hinge support portion 204... Second hinge support 21...Slit 210... Backflow water passage means 22... Valve body 220: Valve body side hinge 221... Valve body side engaging teeth 23. Floater 230 Floater side hinge part 231... Floater side engaging teeth 232 Buoyancy generating section 233 Rod 3, 3a: First and second lids 30 Lid body 300 Guide member 301... Locking member 31...Lid frame 310...Socket 311... Skirt section 312 Flange part 313 Pressure relief section 4, 4a: First and second pressure release means 5, 5a: First and second drainage manholes 50...Inlet 51... Outlet 52....Rise pipe 53, 53a: First and second overflow ports 530, 530a: First and second overflow opening levels 6, 6a...First and second buffer tubes 60...Bottom 61...First straight pipe section 62... First bend 63...Second straight pipe section 64...Second bend 65...Third straight pipe section 7,7a...Drain pipe 8,8a...Drainage equipment 9,9a...Foundation part

Claims

1. A backflow prevention joint to be attached to an inlet and / or an outlet of a drainage system, a base having an inlet opening and an outlet opening forming a valve seat; a valve body having a valve body side hinge portion rotatably supported by a first hinge support portion provided in the vicinity of the outlet opening of the base, A backflow prevention joint characterized in that a backflow water passage means is formed in the base or the valve body.

2. The valve body is provided with a notch, A backflow prevention joint as described in claim 1, characterized in that the backflow water passage means is defined by the notch and the inner circumferential surface of the inlet and / or outlet of the drainage equipment, or the inner circumferential surface of the base.

3. The base portion is provided with a slit, A backflow prevention joint as described in claim 1, characterized in that the backflow water passage means is defined by the slit, the inner surface of the inlet and / or outlet of the drainage equipment, and the edge of the valve body.

4. 4. The backflow prevention joint of claim 3, wherein the slit extends along a central axis of the base.

5. 5. The backflow prevention fitting of claim 4, wherein the slit extends from the inlet opening to the outlet opening of the base.

6. A first catch basin having a bottom, the catch basin having a first inlet opening in a horizontal direction, a first outlet opening in a horizontal direction, and a first overflow port opening upward, A backflow prevention system, comprising: a backflow prevention joint according to claim 1 attached to the first inlet.

7. The backflow prevention system described in claim 6, characterized in that the first overflow port has a first lid portion equipped with a first pressure release means for releasing pressure and / or backflow water in the first catch basin to the outside.

8. The backflow prevention system according to claim 7, characterized in that a first buffer pipe having a bottom at a position higher than the opening level of the first overflow port is connected to the first inlet of the first catch basin.

9. a second catch basin having a bottom and including a second inlet opening horizontally, a second outlet opening horizontally, and a second overflow port opening upward; and The backflow prevention system according to claim 7, characterized in that the first inlet of the first catch basin is directly or indirectly connected to the second outlet of the second catch basin.

10. The backflow prevention system described in claim 9, characterized in that the second overflow port has a second lid portion equipped with a second pressure release means for releasing pressure and / or backflow water in the second catch basin to the outside.

11. The backflow prevention system of claim 10, wherein the flow rate that can be discharged by the second pressure release means is greater than the flow rate that can be backflowed by the backflow water passage means of the backflow prevention fitting attached to the first catch basin.

12. The backflow prevention system according to claim 10, characterized in that a second buffer pipe having a bottom at a position higher than the opening level of the first overflow port and the opening level of the second overflow port is connected to the second inlet of the second catch basin.

Images