JP2009299308A - Back flow preventing structure and drainage facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a back flow preventing structure for surely cutting off water while suppressing a fall between an inflow port and an outflow port. <P>SOLUTION: The back flow preventing structure for preventing drainage from flowing back to the inflow port 11 is provided at a drainage facility 1 comprising the inflow port 11, the outflow port 12 lower than the inflow port 11, and an invert 22 continuous from the inflow port 11 to the outflow port 12. Guide members 21, 21 are provided above along the invert 22 to form a guide passage 2 surrounded by the upper edge of the invert 22 and the guide members 21, 21, and a spherical float 3 having an outer diameter larger than the inner diameter of the inflow port 11 is movably arranged in the guide passage 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a backflow prevention structure that is provided in a drainage mass and prevents a backflow of drainage to an inflow port, and a drainage facility that includes this backflow prevention structure.

  In recent years, there has been a problem that sewage flows backward due to heavy rain caused by torrential rains or typhoons, resulting in inundation damage in semi-underground houses and basements in residential land.

  In order to solve this problem, for example, Patent Document 1 discloses a configuration including a drain pipe that opens downward and a float that moves up and down by a buoyancy in a lattice-shaped stationary device.

  Therefore, when the water level in the drainage mass rises, the float floats against the drainage pipe and closes the end of the drainage pipe, thereby preventing the backflow of drainage.

Moreover, in patent document 2, by providing the arm which rotates like a pendulum, and the buoy attached to the front-end | tip of an arm, an arm rotates by the water flow of a backflow water or a water level rise, and a buoy is an inflow pipe. Backflow is prevented by blocking.
Japanese Utility Model Publication No. 6-67588 JP 2004-197927 A

  However, in the configuration in which the float is moved up and down as in Patent Document 1, it is necessary to make a large difference between the inlet and the outlet.

  Moreover, in the structure provided with the arm as in Patent Document 2, the movement of the arm is hindered due to dust caught on the arm, and water may not be reliably stopped.

  Therefore, an object of the present invention is to provide a backflow prevention structure that can prevent water drop and an outlet and provide a drainage facility provided with the backflow prevention structure.

  In order to achieve the object, the backflow prevention structure of the present invention is provided in a drainage facility including an outlet lower than an inlet and an invert continuous from the inlet to the outlet, and the inlet is provided. A backflow prevention structure for preventing a backflow of sewage to the top, a guide member is provided above the invert, and a guide passage surrounded by the upper edge of the invert and the guide member is formed, A spherical float having an outer diameter larger than the inner diameter of the inlet is movably disposed in the guide passage.

  And the said guide member can be set as the structure inclined so that the side near the said inflow port may become high.

  Further, the upper edge of the invert may be formed so as to be inclined so that the side close to the inflow port becomes higher.

  Further, the invert may be formed in a U-shaped groove whose depth gradually increases from the inlet to the outlet.

  And it is preferable that the said invert or the said guide member is provided with the movement limitation means which restrict | limits a movement so that the said spherical float may not approach the said outflow port.

  Moreover, it is preferable that the said guide member is formed in rail shape with a pair of bar material.

  As described above, in the backflow prevention structure of the present invention, the guide member is provided above the invert, and a guide passage surrounded by the upper edge of the invert and the guide member is formed. A spherical float having an outer diameter larger than the inner diameter of the inlet is movably disposed.

  For this reason, when the water level inside the drainage facility rises, the spherical float moves to the vicinity of the inflow port in response to the buoyancy and flow inside the guide passage, and the backflow of the drainage can be prevented by coming into contact with the inflow port. In addition, a drop between the inlet and the outlet in the drainage facility can be minimized.

  And since the guide member is inclined so that the side close to the inflow port becomes higher, the spherical float can be moved obliquely upward by buoyancy and moved to the vicinity of the inflow port.

  Also, the upper edge of Invert is formed so as to be inclined so that the side closer to the inlet becomes higher, so that the spherical float is moved obliquely downward by gravity to keep it away from the inlet at normal times. It becomes difficult to hit the float, and the spherical float becomes difficult to get dirty.

  Furthermore, the invert is formed in a U-shaped groove whose depth gradually increases from the inflow port to the outflow port, so that the invert for flowing the waste water is inclined, preventing the waste water from staying in the drainage facility. it can.

  And the invert or the guide member is provided with a movement restricting means for restricting the movement so that the spherical float does not approach the outlet, so that the outflow of drainage is not hindered in normal times.

  In addition, since the guide member is formed in a rail shape by a pair of rods, impurities and the like can be removed from above the drainage facility, so that the maintainability is significantly improved.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  First, the whole structure of the drainage system S provided with the drainage mass 1 of this invention is demonstrated using FIG.

  As shown in FIG. 2, the drainage system S according to the present embodiment includes a toilet 62 and a bath 63 in a semi-underground portion 61 of a building 6, and masses 51 and 52 in residential land are provided in the toilet 62 and the bath 63. Connected to the sewage main pipe 54 through the public mass 55 by drain pipes 531, 532, 533 and 534.

  And in the drainage system S of this Embodiment, the drainage mass 1 is arrange | positioned between the mass 51,52 in residential land, and the sewer main 54 which is a public facility. That is, the inflow port 11 (see FIG. 1) is connected to the drain pipe 532 on the downstream side of the residential land mass 51, and the outflow port 12 is connected to the drain pipe 533 on the upstream side of the public mass 55.

  As shown in FIG. 1, the drainage mass 1 includes a cylindrical container-shaped main body cylinder 10, an inspection lid 13 that closes the upper end of the main body cylinder 10, an inflow port 11 provided in the middle of the main body cylinder 10, An outlet 12 provided at a position lower than the inlet 11 in the main body cylinder 10. In FIG. 1, for convenience of explanation, a part of the main body cylinder 10 is broken and described.

  The inflow port 11 is formed in a cylindrical shape by a resin such as vinyl chloride, and is installed in the middle of the side surface of the resin main body cylinder 10 so as to communicate the inside and the outside of the main body cylinder 10. . Further, an annular packing 14 made of rubber or the like is attached to the inflow port 11.

  The outflow port 12 is formed in a cylindrical shape by a resin such as vinyl chloride in the same manner as the inflow port 11 described above, and communicates the inside and outside of the main body cylinder 10 in the middle of the side surface of the main body cylinder 10. It is installed to do.

  Further, the outflow port 12 is arranged at a height such that the tube bottom is lower than the tube bottom of the inflow port 11 described above, and is positioned so as to face the inflow port 11 in the circumferential direction.

  The height difference between the inflow port 11 and the outflow port 12 suffices if the spherical float 3 can be lifted and moved to the vicinity of the inflow port 11 during heavy rain, as will be described later, but if the height difference is too small, the spherical float 3 Therefore, the lower end of the inner peripheral surface of the inlet 11 is preferably higher than the upper end of the inner peripheral surface of the outlet 12.

  In addition, the diameter of the outlet 12 is formed to be substantially the same as the diameter of the inlet 11 described above so that the same amount of drainage can flow. The diameter of the outlet 12 is not limited to be substantially the same as the diameter of the inlet 11, but can be set according to the number and diameter of the inlets 11 and outlets 12 provided in the drainage facility. it can.

  And the drainage mass 1 of this Embodiment is equipped with the backflow prevention structure C inside the cylindrical container-shaped main body cylinder 10. FIG.

  This backflow prevention structure C is mainly configured by a pair of guide bars 21 and 21 as parallel bars, an invert 22, and a spherical float 3.

  The guide rod 21 as the guide member is formed in a columnar shape with resin or the like, and spans between the upper part of the inlet 11 and the upper part of the outlet 12 as shown in FIGS. 3 (a) and 3 (b). It is attached to the inner peripheral surface of the main body cylinder 10 with an adhesive or the like so as to pass.

  The guide rod 21 is attached so as to be inclined so that the side close to the inlet 11 becomes higher so that the spherical float 3 can receive buoyancy and move in the direction of the inlet 11.

  By setting the inclination angle to a gentle angle of 30 degrees or less from the horizontal plane, the spherical float 3 can be moved by buoyancy during heavy rain without increasing the height difference between the inlet 11 and the outlet 12. .

  Further, the guide bar 21 is formed so that the spherical float 3 does not deviate from the guide passage 2. That is, two guide rods 21 are provided in parallel above the invert 22 at intervals that are narrower than the diameter of the spherical float 3 and at a height lower than the diameter of the spherical float 3 from the upper surface of the bottom plate 24. Yes.

  The invert 22 is formed in a substantially U-shaped groove continuous in the diametrical direction at the center of the bottom plate 24 that closes the lower end surface of the main body cylinder 10. As shown in FIG. On the side close to the outlet 12 of the guide surfaces 22a and 22a, the guide surfaces 22a and 22a in which the vicinity of the upper edges 22d and 22d is inclined obliquely to hold the spherical float 3 Stopper surfaces 22c and 22c as movement limiting means formed.

  This flow path surface 22b is formed in a substantially U-shaped groove shape and is provided with a downward slope from the inflow port 11 toward the outflow port 12, so that the waste water flowing in from the inflow port 11 flows smoothly to the outflow port 12. Can be done.

  Further, the guide surfaces 22a and 22a protect the spherical float 3 from being scratched when moving the upper edge 22d and 22d of the invert 22, and stopper surfaces 22c and 22c are provided at the ends so that the spherical float is provided. 3 movement is restricted.

  In addition, the end of the substantially U-shaped invert 22 on the outlet 12 side has a diameter that is larger by the thickness of the pipe of the outlet 12, so that the outlet 12 can be fitted and fixed. ing.

  Further, the upper surface of the bottom plate 24 is inclined so that the vicinity of the center where the invert 22 is provided is lowered in order to prevent dust from staying when drainage overflows from the invert 22.

  In this embodiment, the guide passage 2 is formed by being surrounded by the upper edges 22d and 22d of the invert 22 and the guide rods 21 and 21.

  The guide passage 2 is formed to be slightly larger than the spherical float 3 so that the spherical float 3 can move.

  That is, since the invert 22 is below the guide passage 2, the spherical float 3 is restricted from moving downward, and since there is a pair of guide rods 21, 21 whose intervals are adjusted above, the spherical float 3 is upward. Further, since the height of the pair of guide bars 21 and 21 from the bottom plate 24 is adjusted, the movement to the side is restricted.

  The spherical float 3 is formed in a spherical shape having an outer diameter larger than the inner diameter of the inflow port 11 by resin or the like, and can move in the direction connecting the inflow port 11 and the outflow port 12 to the guide passage 2 described above. Is arranged.

  In addition, the spherical float 3 is adjusted to have a specific gravity in the range of 0.9 to 1.0 in consideration of the size of buoyancy and gravity acting during heavy rain. The specific gravity is preferably 0.95.

  Accordingly, the spherical float 3 is placed on the upper edges 22d and 22d of the invert 22 and the guide surfaces 22a and 22a under normal gravity and moved so as to be pushed and rolled by the domestic waste water flowing in from the inflow port 11. Then, it stops at the positions of the stopper surfaces 22c and 22c.

  On the other hand, when the water level in the mass rises during heavy rain, the spherical float 3 receives buoyancy and moves obliquely upward along the guide rods 21 and 21, and flows into the inlet 11 by the flow flowing into the inlet 11. It sucks and touches.

  Next, the effect | action of the backflow prevention structure C of this Embodiment is demonstrated.

  Conventionally, in the building 6 having the semi-underground portion 61 lower than the ground surface 56, sewage exceeding the capacity of the sewage main pipe 54 flows backward during heavy rain, and the sewage overflows into the semi-underground portion 61 or air flows backward together with the sewage. Sometimes happened.

  That is, if the drainage cannot flow into the sewage main pipe 54 during heavy rain, it will overflow from the public mass 55 and the like to the surface 56. However, if there is a semi-underground portion 61 having a lower head than the surface 56, first this half It will flow backward so as to overflow the underground part 61.

  Here, if the drainage mass 1 having the backflow prevention structure C is disposed between the sewage main pipe 54 and the residential land mass 51, the backflow of sewage can be prevented.

  That is, the backflow prevention structure C of the present embodiment is provided with guide rods 21 and 21 as guide members inclined so that the side close to the inflow port 11 becomes higher along the invert 22, and the upper edge 22 d, A guide passage 2 surrounded by 22d and guide rods 21 and 21 is formed, and a spherical float 3 having an outer diameter larger than the inner diameter of the inflow port 11 is movably disposed in the guide passage 2.

  For this reason, when the water level inside the drainage mass 1 rises, the spherical float 3 that has received buoyancy and flow moves obliquely upward along the guide rods 21 and 21 in the guide passage 2 and hits the inlet 11. The backflow of sewage can be prevented by closing the inlet 11 in contact.

  That is, as shown in FIG. 4A, when sewage flows backward from the downstream outlet 12 and is stored in the drainage mass 1, the water level inside the drainage mass 1 rises and eventually flows back to the inlet 11. To do.

  Then, since the specific gravity of the spherical float 3 is smaller than 1.0, the spherical float 3 is lifted by receiving buoyancy and rises until it comes into contact with the guide rods 21 and 21 serving as guide members. By receiving, it moves obliquely upward along the guide rods 21 and 21.

  Then, as shown in FIG. 4B, when the spherical float 3 moves to the vicinity of the inflow port 11, it is sucked to the inflow port 11 by the flow of sewage flowing into the inflow port 11, and reaches the end of the inflow port 11. It contacts the attached packing 14.

  Furthermore, when the water level inside the drainage mass 1 rises, the spherical float 3 is pressed against the inlet 11 by water pressure, so that complete water stoppage is achieved.

  Further, when the water level is lowered, the spherical float 3 is separated from the inlet 11 by gravity and is placed on the invert 22, and drainage flows from the inlet 11, so that the outlet 12 side. Move to.

  In the initial case of FIG. 4A, the sewage flows backward through the inflow port 11, but the inflow port 11 is a mass within the residential land installed under the semi-underground portion 61 as shown in FIG. Since it is connected to 51 and 52, the semi-underground part 61 is not flooded.

  In addition, in the backflow prevention structure C of the present embodiment, a drop between the inlet 11 and the outlet 12 in the drainage mass 1 can be minimized.

  That is, since the spherical float 3 moves obliquely along the guide rods 21 and 21 instead of in the vertical direction, the vertical movement distance becomes small. Therefore, the height difference between the inlet 11 and the outlet 12 is increased. Can be reduced.

  For this reason, the backflow prevention structure C can be installed even when the depth in which the drain pipes 531, 532, 533, 534, the public mass 55, the sewage main pipe 54, etc. are buried is shallow.

  Here, the guide rods 21 and 21 as the guide members are inclined so that the side close to the inflow port 11 becomes higher, so that the spherical float 3 is inclined upward by the component in the direction along the guide rods 21 and 21 of buoyancy. To the vicinity of the inlet 11.

  Further, since the spherical float 3 is arranged at a certain distance from the guide passage 2 in normal times, it is possible to prevent the foreign matter from being caught and to be easily removed when the foreign matter is caught. It has a structure.

  In particular, in the present embodiment, the guide rods 21 and 21 as the guide members are formed in a rail shape by a pair of parallel rod members, so that impurities and the like can be removed from above the drainage mass 1. Maintenance workability is greatly improved.

  In addition, the spherical float 3 is moved by gravity and the flow of house drainage during normal times, and is moved by the flow of buoyancy and sewage backflow in heavy rain, so that it can be reliably stopped by a simple structure without using a mechanical structure. Can be water.

  And the backflow prevention structure C of this Embodiment has a simpler structure by forming the guide channel | path 2 using the invert 22 with which the drainage mass 1 is originally provided.

  Further, the invert 22 is provided with stopper surfaces 22c and 22c as movement restricting means for restricting movement so that the spherical float 3 does not approach the outflow port 12, thereby preventing the outflow of the house drainage in normal times. Absent.

  That is, when the drainage flow rate is high under normal circumstances, the spherical float 3 may approach the outlet 12 and impinge on the inner air cross section of the outlet 12 to obstruct the flow. If it does, it will not interfere with the flow of domestic wastewater.

  Further, since the specific gravity of the spherical float 3 is adjusted to 0.9 or more and less than 1.0, the spherical float 3 is affected by the flow even when the guide members 21 and 21 are not inclined. Since it becomes easy to move to 11 side, it becomes easy to stop water, and when it falls, it will fall easily by gravity.

  That is, when the specific gravity exceeds 1.0, the spherical float 3 does not float up, and when the specific gravity is small, when the water level falls, the spherical float 3 is adjusted to the above range so that it does not fall due to gravity.

  And the drainage mass 1 as a drainage facility of this Embodiment becomes a drainage facility which can prevent the backflow of drainage by providing the above-mentioned backflow prevention structure C. FIG.

  Thus, if the backflow can be prevented, even if the sewage overflowing from the sewage main pipe 54 flows back and reaches the drainage mass 1, the backflow can be prevented at this position, so that the semi-underground portion 61 of the building 6 may be submerged. Disappear.

  Hereinafter, with reference to FIGS. 5, 6, and 7, a drainage mass 1 </ b> A as a drainage facility including a backflow prevention structure C <b> 1 of a form different from the above embodiment will be described.

  The description of the same or equivalent parts as those described in the above embodiment will be given the same reference numerals.

  First, in terms of configuration, the drainage mass 1A of the present embodiment includes a backflow prevention structure C1 inside a cylindrical container body 10 as shown in FIG. In FIG. 5, for convenience of explanation, a part of the main body cylinder 10 is broken and described.

  This backflow prevention structure C1 is mainly configured by a guide rod 23 as a guide member, an invert 22, and a spherical float 3.

  The guide rod 23 as the guide member is formed in a circular arc shape with resin or the like, and as shown in FIGS. 6 (a) and 6 (b), the upper portion of the inlet 11 on the inner peripheral surface of the main body cylinder 10. Further, it is attached to the inner peripheral surface of the main body cylinder 10 with an adhesive or the like.

  The guide rod 23 is attached so as to be inclined so that the side close to the inlet 11 becomes higher so that the spherical float 3 can receive buoyancy and move in the direction of the inlet.

  Further, the guide rod 23 is formed so that the spherical float 3 does not deviate from the guide passage 2A. That is, the guide rod 23 is provided above the invert 22 and both ends of the arc are provided at positions lower than the diameter of the spherical float 3 from the upper surface of the bottom plate 24.

  The invert 22 is formed in a U-shaped groove continuous in the diametrical direction at the center of the bottom plate 24 that closes the lower end surface of the main body cylinder 10, and as shown in FIG. The flow path surface 22b for flowing is provided.

  In addition, in this embodiment, as shown in FIG. 6B, the upper surface of the bottom plate 24 is inclined so that the vicinity of the center where the invert 22 is provided is lowered, and the side closer to the inlet 11 is higher. It is inclined to become.

  Furthermore, since the invert 22 is formed in a substantially U-shaped groove whose depth gradually increases from the inlet 11 toward the outlet 12, the flow path surface 22b is inclined so that the side close to the inlet 11 becomes higher. ing.

  As described above, in this embodiment, the guide passage 2A is formed by being surrounded by the upper edges 22d and 22d of the invert 22 and the guide rod 23.

  Next, the operation will be described. The backflow prevention structure C1 of the present embodiment is provided with a guide rod 23 as a guide member that is inclined so that the side close to the inflow port 11 is raised along the invert 22, and the upper edge of the invert 22 is provided. A guide passage 2A surrounded by 22d, 22d and a guide rod 23 is formed, and a spherical float 3 having an outer diameter larger than the inner diameter of the inflow port 11 is movably disposed in the guide passage 2A.

  For this reason, when the water level in the drainage mass 1A as the drainage facility rises, the spherical float 3 receiving the buoyancy moves obliquely upward along the guide rod 23 in the guide passage 2A and hits the inlet 11. The backflow of sewage can be prevented by closing the inlet 11 in contact.

  That is, as shown in FIG. 7A, when the sewage flows backward from the downstream outlet 12 and is stored in the drainage mass 1, the water level inside the drainage mass 1 rises and eventually flows back to the inlet 11. To do.

  Then, since the specific gravity of the spherical float 3 is smaller than 1.0, the spherical float 3 floats by receiving buoyancy, and moves up obliquely along the guide rod 23 when it rises to contact with the guide rod 23 as a guide member.

  Next, as shown in FIG. 7B, when the spherical float 3 moves to the vicinity of the inflow port 11, it is sucked by the inflow port 11 by the flow of sewage flowing into the inflow port 11, and the end portion of the inflow port 11. It abuts on the packing 14 attached to.

  Furthermore, when the water level inside the drainage mass 1 rises, the spherical float 3 is pressed against the inlet 11 by water pressure, so that complete water stoppage is achieved.

  When the water level drops, the spherical float 3 falls away from the inlet 11 due to gravity and is placed on the invert 22, and flows toward the outlet 12 due to the flow of drainage from the inlet 11 and gravity. Moving.

  Further, in this embodiment, since the upper surface of the bottom plate 24 is inclined so that the side close to the inlet 11 is higher, the upper edges 22d and 22d of the invert 22 are also inclined so that the side closer to the inlet 11 is higher. ing.

  For this reason, the spherical float 3 can be moved obliquely downward by gravity in a normal state, and can be moved away from the inflow port 11. Accordingly, the wastewater does not collide with the spherical float 3, and the impurities contained in the wastewater do not accumulate on the flow path surface 22b in the vicinity of the spherical float 3 to obstruct the flow of the wastewater.

  Furthermore, since the invert 22 is formed in a substantially U-shaped groove whose depth gradually increases from the inflow port 11 toward the outflow port 12, the flow path surface 22b of the invert 22 through which drainage flows is inclined. It is possible to prevent drainage from staying in the drainage mass 1.

  By preventing the wastewater from staying in this way, it is possible to prevent the staying wastewater from being spoiled and generating odors or causing microorganisms to propagate.

  In addition, the upper surface of the bottom plate 24 is inclined so that the vicinity of the center where the invert 22 is provided is lowered, and the drainage overflowing from the channel surface 22b returns to the channel surface 22b again. It can prevent staying.

  Further, the guide rod 23 as a guide member is provided with a bent portion 231 as movement restriction means for restricting movement so that the spherical float 3 does not approach the outflow port 12, thereby preventing drainage from flowing out under normal conditions. There is no hindrance.

  Other configurations and operational effects are substantially the same as those in the above-described embodiment, and thus the description thereof is omitted.

  The preferred embodiments and examples of the present invention have been described in detail with reference to the drawings, but the specific configuration is not limited to the embodiments or examples, and does not depart from the gist of the present invention. A degree of design change is included in the present invention.

  For example, in this Embodiment and the Example, although the drainage mass 1 and 1A demonstrated the case where it was formed with resin, it is not limited to this, You may form with concrete etc.

  Further, in the present embodiment and examples, the case where the stopper surfaces 22c and 22c and the bent portion 231 are provided as the movement restricting means of the spherical float 3 is described, but the present invention is not limited to this, and the movement restricting means is not limited thereto. May not be provided.

  Furthermore, in this Embodiment and an Example, although the specific gravity of the spherical float 3 is adjusted to 0.9 or more and less than 1.0, it is not limited to this, Depending on the structure of the packing 14, etc., this A spherical float 3 having a specific gravity below the range can also be used.

  In the present embodiment and examples, the case where the drainage masses 1 and 1A as the drainage facilities provided with the backflow prevention structures C and C1 are provided separately from the residential land masses 51 and 52 is described. However, a backflow prevention structure may be provided in the housing area mass.

  In the present embodiment and examples, the case where the guide rods 21 and 21 and the guide rod 23 as the guide members are inclined has been described. However, the present invention is not limited to this and is not inclined at all. It may be a guide member installed horizontally.

It is a perspective view explaining the composition of the drainage facility provided with the backflow prevention structure of the best embodiment of the present invention. It is explanatory drawing explaining the structure of a drainage system provided with the drainage facility of the best embodiment of this invention. It is sectional drawing explaining the structure of the backflow prevention structure of the best embodiment of this invention. (A) is a longitudinal cross-sectional view, (b) is a cross-sectional view. It is explanatory drawing explaining an effect | action of the backflow prevention structure of the best embodiment of this invention. (A) is the state which the spherical float floated, (b) is the state which the spherical float contact | abutted to the inflow port. It is a perspective view explaining the structure of the drainage facility provided with the backflow prevention structure of an Example. It is sectional drawing explaining the structure of the backflow prevention structure of an Example. (A) is a longitudinal cross-sectional view, (b) is a cross-sectional view. It is explanatory drawing explaining the effect | action of the backflow prevention structure of an Example. (A) is the state which the spherical float floated, (b) is the state which the spherical float contact | abutted to the inflow port.

Explanation of symbols

1,1A Drainage mass (drainage facility)
C, C1 Backflow prevention structure 11 Inlet 12 Outlet 2, 2A Guide passage 21 Guide rod (guide member)
22 Invert 22c Stopper surface (movement restriction means)
22d Upper edge 23 Guide rod (guide member)
231 Bent part (movement restriction means)
3 Spherical float

Claims (6)

A reverse flow prevention structure provided in a drainage facility comprising an outlet lower than an inlet and an invert continuous from the inlet to the outlet, and preventing a reverse flow of sewage to the inlet;
A guide member is provided above the invert, and a guide passage surrounded by the upper edge of the invert and the guide member is formed.
A backflow prevention structure, wherein a spherical float having an outer diameter larger than the inner diameter of the inlet is movably disposed in the guide passage.   The backflow prevention structure according to claim 1, wherein the guide member is inclined so that a side close to the inflow port becomes higher.   3. The backflow prevention structure according to claim 1, wherein an upper edge of the invert is formed so as to be inclined so that a side close to the inflow port is raised. 4.   4. The backflow prevention structure according to claim 1, wherein the invert is formed in a U-shaped groove whose depth gradually increases from the inflow port toward the outflow port. 5. .   The reverse flow according to any one of claims 1 to 4, wherein the invert or the guide member includes a movement restricting unit that restricts movement so that the spherical float does not approach the outlet. Prevention structure. The backflow prevention structure according to any one of claims 1 to 5, wherein the guide member is formed in a rail shape by a pair of bar members.

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