JP7684199B2 - Piping structure and pipe fittings - Google Patents

Description

The present invention relates to a piping structure and a pipe joint.

A siphon drainage system is disclosed that has a temporary storage tank that temporarily stores wastewater discharged from plumbing fixtures, and multiple siphon drainage pipes that are connected to the temporary storage tank and apply siphon force to the wastewater stored in the temporary storage tank to cause it to flow out (see Patent Document 1). The siphon drainage pipes are configured with a horizontal pull pipe that is connected to the temporary storage tank, and a vertical pipe that communicates with the downstream side of the horizontal pull pipe, extends downward, and merges with the drainage vertical pipe.

JP 2011-256557 A

In the conventional example described above, the inner diameter of the siphon drain pipe is made smaller than the 20 to 25 mm inner diameter used in conventional siphon drain systems, allowing full flow to occur quickly at the drop-off point from the horizontal pipe to the vertical pipe, shortening the time until the siphon force is activated (siphon generation time).

However, the amount of wastewater discharged per unit time from plumbing fixtures varies from fixture to fixture. For example, a toilet discharges less than 10 liters at a time, while a bathtub may discharge around 200 liters at a time. When draining such a large amount of wastewater, it may take a long time to drain using a siphon drain pipe with a small inner diameter. Also, if the horizontal pipe is long (for example, 10 m), it takes a long time to obtain the flow rate required for siphoning at the drop-in section, which lengthens the time for siphoning to occur, and wastewater is more likely to stagnate in the temporary storage tank.

The present invention aims to shorten the siphon generation time while ensuring the amount of wastewater treatment in a structure in which multiple siphon drain pipes are installed in a temporary storage tank.

The piping structure according to the first aspect comprises a plurality of horizontal pipes connected via a branch joint to the downstream side of a temporary storage tank provided in a drainage system and discharging wastewater discharged from the temporary storage tank in a horizontal direction, a junction section that merges the plurality of first horizontal pipes into one, and a vertical pipe connected downstream of the junction section that generates a siphon force in the horizontal pipes by causing the wastewater to flow downward, and the branch joint comprises a plurality of piping connection sections to which the upstream ends of the plurality of horizontal pipes are respectively connected, and the plurality of piping connection sections are each positioned differently in the wastewater inflow direction at the branch joint, and adjacent peripheries of the plurality of piping connection sections overlap in the wastewater inflow direction.

In the piping structure according to the first aspect, the temporary storage tank is drained through a plurality of horizontal pipes, which ensures a sufficient amount of wastewater treatment and prevents the wastewater from overflowing into a bathroom or the like located upstream of the temporary storage tank.
In addition, in the piping structure according to the first aspect, since the multiple horizontal pipes merge into one at the junction, the portion between the junction and the vertical pipe can be quickly filled with water, thereby shortening the time it takes for siphoning to occur.
Furthermore, in the piping structure according to the first aspect, the positions of the multiple pipe connections of the branch joint in the wastewater inflow direction are different from each other, and adjacent multiple pipe connections have parts of their outer circumferences overlapping in the wastewater inflow direction. Therefore, for example, adjacent multiple pipe connections do not overlap in the wastewater inflow direction. In other words, the size of the branch joint can be made smaller than in a configuration in which adjacent multiple pipe connections are spaced apart in a direction perpendicular to the wastewater inflow direction.

In the second aspect, in the piping structure according to the first aspect, the junction is a junction joint, and the junction joint has a plurality of piping connections to which the downstream ends of the plurality of horizontal pipes are respectively connected, and the plurality of piping connections are each located at a different position in the wastewater outflow direction at the junction joint, and adjacent peripheries partially overlap in the wastewater inflow direction.

In the piping structure according to the second aspect, the positions of the multiple pipe connections of the junction joint in the drainage outflow direction are different from each other, and adjacent multiple pipe connections have parts of their outer circumferences overlapping in the drainage outflow direction. Therefore, for example, adjacent multiple pipe connections do not overlap in the drainage outflow direction. In other words, the size of the junction joint can be made smaller than in a configuration in which adjacent multiple pipe connections are spaced apart in a direction perpendicular to the drainage outflow direction.
In addition, the distance between the horizontal pipes connected to the multiple pipe connections of the branch joint and the multiple pipe connections of the junction joint can be reduced, thereby narrowing the arrangement pitch of the horizontal pipes when laying them, improving design freedom during construction.

In the third aspect, in the piping structure according to the first or second aspect, the branch joint has a straight pipe section that is connected to the temporary storage tank and extends in a straight line, and a branch pipe section that branches off from the middle of the straight pipe section and has a portion that extends obliquely with respect to the pipe axis direction of the straight pipe section, and the downstream end of the straight pipe section and the downstream end of the branch pipe section are each provided with the piping connection section.

In the piping structure according to the third aspect, the wastewater in the temporary storage tank flows through the straight pipe section of the branch joint to one of the horizontal pipes, and then flows through the branch pipe section to the other horizontal pipe. Here, in the straight pipe section of the branch joint, the wastewater in the temporary storage tank flows linearly, so there is little drop in flow rate, and the section between the junction and the vertical pipe can be filled up quickly. This shortens the time it takes for siphoning to occur.

The fourth aspect is a piping structure according to the third aspect, which cites the second aspect, in which the downstream end of the horizontal pipe connected to the straight pipe section of the branch joint is connected to the branch pipe section of the junction joint, and the downstream end of the horizontal pipe connected to the branch pipe section of the branch joint is connected to the branch pipe section of the junction joint.

In the piping structure according to the fourth aspect, wastewater flows from the straight pipe section of the branch joint to the branch pipe section of the junction joint through one horizontal pipe. Also, wastewater flows from the branch pipe section of the branch joint to the straight pipe section of the junction joint through the other horizontal pipe. Therefore, the difference in flow rate that occurs at the branch joint is offset by the junction joint. This suppresses flow bias in the multiple horizontal pipes, and allows wastewater to flow quickly to the section between the junction joint and the vertical pipe.

The piping structure according to the fifth aspect includes a plurality of horizontal pipes connected to the downstream side of a temporary storage tank provided in a drainage system and discharging wastewater discharged from the temporary storage tank in a horizontal direction, a junction joint that merges the plurality of first horizontal pipes into one, and a vertical pipe connected to the downstream side of the junction joint and generating a siphon force in the horizontal pipe by causing the wastewater to flow downward, the junction joint includes a plurality of piping connections to which the upstream ends of the plurality of horizontal pipes are respectively connected, and the plurality of piping connections are each positioned differently in the wastewater outflow direction at the junction joint, and adjacent peripheries of the piping connections overlap in the wastewater outflow direction.

In the piping structure according to the fifth aspect, the temporary storage tank is drained through a plurality of horizontal pipes, thereby ensuring a sufficient amount of wastewater treatment and preventing the wastewater from overflowing into a bathroom or the like located upstream of the temporary storage tank.
In the piping structure according to the fifth aspect, since the multiple horizontal pipes are joined together at the joint, the portion between the joint and the vertical pipe can be quickly filled with water, thereby shortening the time it takes for siphoning to occur.
Furthermore, in the piping structure according to the fifth aspect, the positions of the multiple pipe connections of the junction joint in the drainage outflow direction are different from each other, and adjacent multiple pipe connections have parts of their outer circumferences overlapping in the drainage outflow direction. Therefore, for example, adjacent multiple pipe connections do not overlap in the drainage outflow direction. In other words, the size of the junction joint can be made smaller than in a configuration in which adjacent multiple pipe connections are spaced apart in a direction perpendicular to the drainage outflow direction.

The pipe fitting according to the sixth aspect comprises a first pipe connection portion to which a first tubular body is connected, and a plurality of second pipe connection portions to which a plurality of second tubular bodies are respectively connected, and the second pipe connection portions are each located at different positions in the flow direction of the fluid flowing through the first tubular body, and adjacent second pipe connection portions have portions of their outer circumferences overlapping in the flow direction.

In the pipe fitting according to the sixth aspect, the positions of the multiple second pipe connections in the flow direction of the fluid flowing through the first tubular body are different, and adjacent multiple second pipe connections have portions of their outer circumferences overlapping in the fluid flow direction. As a result, for example, adjacent multiple second pipe connections do not overlap in the fluid flow direction. In other words, the fitting size can be made smaller than in a configuration in which adjacent multiple second pipe connections are spaced apart in a direction perpendicular to the fluid flow direction.

According to the present invention, in a structure in which multiple siphon drain pipes are provided in a temporary storage tank, it is possible to shorten the time during which siphon force is generated while ensuring the amount of drainage treatment.

FIG. 2 is a side view showing the piping structure according to the embodiment. FIG. 1 is a perspective view showing a piping structure according to an embodiment of the present invention. FIG. 2 is a plan view showing a piping structure according to the embodiment. FIG. 4 is an enlarged view of a portion indicated by an arrow 4 in FIG. 3 . FIG. 4 is an enlarged view of a portion indicated by an arrow 5 in FIG. 3 . FIG. 5 is a cross-sectional view of the portion shown in FIG. 4 . FIG. 6 is a cross-sectional view of the portion shown in FIG. 5 . 4 is an enlarged plan view of a branch joint of a modified example (corresponding to the portion indicated by the arrow 4 in FIG. 3 ). FIG. FIG. 11 is a perspective view showing a piping structure according to another embodiment. FIG. 11 is a plan view showing a piping structure according to another embodiment. FIG. 11 is an enlarged view of a portion indicated by an arrow 11 in FIG. FIG. 12 is a cross-sectional view of the portion shown in FIG.

Below, the embodiment of the present invention will be described with reference to the drawings. Components indicated with the same reference numerals in each drawing are the same or similar components. Note that duplicated explanations and reference numerals in the embodiments described below may be omitted. Furthermore, all drawings used in the following description are schematic, and the dimensional relationships of each element, the ratios of each element, etc. shown in the drawings do not necessarily match the actual ones. Furthermore, the dimensional relationships of each element, the ratios of each element, etc. do not necessarily match between multiple drawings.

Figure 1 shows an outline of the piping structure 20 according to this embodiment. The piping structure 20 is a siphon drainage system structure that uses siphon force to discharge wastewater from a plumbing fixture 12. As an example, the piping structure 20 is used in an apartment building 10 that is formed in multiple layers. As shown in Figure 2, this piping structure 20 includes a plurality (a pair in this embodiment) of first horizontal pipes 31A, 31B, a junction joint 48 as an example of a junction section, a second horizontal pipe 44, and a vertical pipe 46. The portion from the first horizontal pipes 31A, 31B to the vertical pipe 46 can also be called a siphon drainage pipe 40.

The piping structure 20 includes a drainage standpipe 22 that drains wastewater downward. A plurality of drainage standpipes 22 are provided at different locations on the floor of the apartment building 10. For example, the drainage standpipes 22 are housed vertically (in the vertical direction) in a piping space (also called a pipe space, etc.) that is separated by walls from each dwelling unit on each floor of the apartment building 10, and penetrate the slab 14 on each floor of the apartment building 10.

Each dwelling unit in the apartment complex 10 is provided with a plumbing fixture 12. The plumbing fixture 12 is, for example, a bathroom unit, and is formed by integrating a bathtub 12A and a washing area 12B. One end of a drainage inlet pipe 24 is connected to the plumbing fixture 12.

The other end of the wastewater inlet pipe 24 is connected to the temporary storage tank 30. As a result, the wastewater inlet pipe 24 introduces wastewater discharged from the bathtub 12A and the washing area 12B of the plumbing fixtures 12 into the temporary storage tank 30. It is preferable that the wastewater inlet pipe 24 is arranged with a slope so that the temporary storage tank 30 side is lower.

The other end of the wastewater inlet pipe 24 is connected to a temporary storage tank 30, which is described below as an example of a temporary storage tank. As a result, the wastewater inlet pipe 24 introduces wastewater discharged from the bathtub 12A and the washing area 12B of the plumbing fixtures 12 into the temporary storage tank 30. It is preferable that the wastewater inlet pipe 24 is arranged with a slope so that the temporary storage tank 30 side is lower. The wastewater inlet pipe 24 has a nominal diameter of 50A (inner diameter of 50 mm), for example.

As shown in FIG. 3, a branch joint 28 is connected downstream of an outlet 30A, which serves as a drainage outlet of a temporary storage tank 30 provided in the drainage system. The inner diameter of the outlet 30A is, for example, about 53 mm.

The branch joint 28 has a plurality of (two in this embodiment) pipe connections 29A, 29B to which the upstream ends of the first horizontal pipes 31A, 31B are respectively connected. The pipe connections 29A, 29B are different in position in the wastewater inflow direction (direction indicated by arrow F1 in the figure) in the branch joint 28. Here, the wastewater inflow direction in the branch joint 28 is the direction in which wastewater flows into the branch joint 28, and in this embodiment, it is the direction in which wastewater flows from the outlet 30A of the temporary storage tank 30 to the branch joint 28, which is the same direction as the pipe axis direction (central axis direction) of the outlet 30A. In this embodiment, as shown in FIG. 4, the pipe connection 29A is located downstream of the pipe connection 29B. In addition, parts of the outer peripheries of the pipe connections 29A, 29B overlap each other in the wastewater inflow direction F1. In other words, when viewed from the wastewater inflow direction F1, the piping connections 29A and 29B overlap each other at portions of their outer peripheries in the wastewater inflow direction F1.

The branch joint 28 includes a straight pipe section 28A and a branch pipe section 28B. The straight pipe section 28A is connected to the outlet 30A of the temporary storage tank 30 via a different diameter joint 34. Specifically, the upstream end of the straight pipe section 28A is connected to the outlet 30A of the temporary storage tank 30 via a different diameter joint 34. The branch joint 28 may be directly connected to the outlet 30A without using the different diameter joint 34, or a same diameter joint may be used. The straight pipe section 28A extends linearly along the wastewater inflow direction F1. The branch pipe section 28B branches off from the middle of the straight pipe section 28A and has a branch section 28C that extends obliquely with respect to the pipe axis direction of the straight pipe section 28A.

The straight pipe section 28A and the branch pipe section 28B intersect at an acute angle downstream at the branch point. The branch pipe section 28B is bent midway. This makes the downstream end of the branch pipe section 28B parallel to the downstream end of the straight pipe section 28A.

The downstream end of the straight pipe section 28A is provided with a pipe connection section 29A. Also, the downstream end of the branch pipe section 28B is provided with a pipe connection section 29B.

The upstream end of the first horizontal pipe 31A is connected to the piping connection 29A of the straight pipe section 28A in the branch joint 28. The downstream end of the first horizontal pipe 31A is connected to the piping connection 49B of the branch pipe section 48B in the junction joint 48 described later.

The upstream end of the first horizontal pipe 31B is connected to the piping connection 49B of the branch pipe section 28B in the branch joint 28. The downstream end of the first horizontal pipe 31B is connected to the piping connection 49A of the straight pipe section 48A in the junction joint 48 described later.

2 and 3, the first horizontal pipes 31A and 31B are pipes arranged approximately parallel to each other in the horizontal direction, for example, along the slab 14. The first horizontal pipes 31A and 31B are horizontal pipes connected to the downstream side of the branch joint 28 and discharge wastewater discharged from the temporary storage tank 30 in the horizontal direction. The first horizontal pipes 31A and 31B are formed of polybutene pipes with a nominal diameter of 25J (inner diameter of about 28 mm), for example, and are arranged without gradient along the horizontal direction on the slab 14. Note that without gradient here does not necessarily have to be strictly horizontal, and includes those with some steps or gradients along the slab 14. The upstream end of the first horizontal pipe 31A is connected to the downstream end of the straight pipe section 28A in the branch joint 28. The upstream end of the first horizontal pipe 31B is connected to the downstream end of the branch pipe section 28B in the branch joint 28. The two first horizontal pipes 31A, 31B do not necessarily have to be parallel to each other, depending on the conditions of the location where they are installed.

As shown in Figures 4 and 7, a junction joint 48, which is an example of a junction section, merges the first horizontal pipes 31A and 31B into one.

The junction joint 48 has a plurality of (two in this embodiment) pipe connections 49A, 49B to which the upstream ends of the first horizontal pipes 31A, 31B are respectively connected. The positions of the wastewater outflow direction (direction indicated by arrow F2 in the figure) at the junction joint 48 are different for the plurality of pipe connections 49A, 49B. Here, the wastewater outflow direction at the junction joint 48 is the direction in which wastewater flows out to the junction joint 48, and in this embodiment, it is the direction in which wastewater flows out from the junction joint 48 to the second horizontal pipe 44, which is the same direction as the pipe axis direction (central axis direction) of the second horizontal pipe 44. In addition, the wastewater outflow direction F2 in this embodiment is the same direction as the wastewater inflow direction F1 in a plan view, as shown in FIG. 3. Note that this is not limited to this configuration, and the wastewater outflow direction F2 may be slightly inclined with respect to the wastewater inflow direction F1. In this embodiment, as shown in FIG. 5, the pipe connection part 49B is located downstream of the pipe connection part 29A. In addition, parts of the outer circumferences of the pipe connections 49A and 49B overlap with each other in the drainage outflow direction F2. In other words, when viewed from the drainage outflow direction F2, parts of the outer circumferences of the pipe connections 49A and 49B overlap with each other in the drainage outflow direction F2.

The junction joint 48 has a straight pipe section 48A and a branch pipe section 48B. The downstream end of the first horizontal pipe 31A is connected to the straight pipe section 48A by a piping connection section 49A. The upstream end of the second horizontal pipe 44 is connected to the straight pipe section 48A. This straight pipe section 48A extends linearly along the drainage outflow direction F2. The branch pipe section 48B branches off midway through the straight pipe section 48A and has a branch section 48C that extends obliquely with respect to the pipe axis direction of the straight pipe section 48A.

The straight pipe section 48A and the branch pipe section 48B intersect at an acute angle upstream at the branching point. The branch pipe section 48B is bent midway. This makes the upstream end of the branch pipe section 48B parallel to the upstream end of the straight pipe section 48A.

The upstream end of the straight pipe section 48A is provided with a pipe connection section 49A. The upstream end of the branch pipe section 48B is provided with a pipe connection section 49B.

The second horizontal pipe 44 is, for example, a pipe arranged along the slab 14, connected to the downstream side of the junction joint 48, and discharges the combined wastewater laterally. The upstream end of this second horizontal pipe 44 is connected to the piping connection part of the straight pipe section 48A at the junction joint 48. The second horizontal pipe 44 is formed of, for example, a rigid polyvinyl chloride pipe with a nominal diameter of 30A (inner diameter of 30 mm), and is arranged without gradient along the horizontal direction on the slab 14.

The vertical pipe 46 is connected to the downstream side of the second horizontal pipe 44, and generates a siphon force in the first horizontal pipes 31A, 31B and the second horizontal pipe 44 by flowing the wastewater downstream. The vertical pipe 46 is, for example, a hard polyvinyl chloride pipe with a nominal diameter of 25A (inner diameter of 25 mm). The vertical pipe 46 is arranged, for example, in the up-down direction (vertical direction) along the drainage standpipe 22. The downstream end of the vertical pipe 46 reaches the junction joint 26. The junction joint 26 is a pipe joint that merges the wastewater from the vertical pipe 46 into the drainage standpipe 22. The length from the junction joint 48 to the vertical pipe 46 may be, for example, 500 to 1000 mm. The junction joint 48, which is the junction, is not located in a meter box outside the wall 18, but is located, for example, inside the wall 18, that is, on the dwelling unit side.

The drop-in portion located at the boundary between the second horizontal pipe 44 and the vertical pipe 46 is illustrated as a continuous vent pipe, but a pipe fitting such as an elbow may be placed in this vent pipe portion. If a pipe fitting is placed here, an inspection hatch or the like can be appropriately provided in the pipe fitting. The drop-in portion from the second horizontal pipe 44 to the vertical pipe 46 is placed outside the wall 18 of the dwelling unit, for example, inside a meter box.

An air vent pipe 50 is further connected to the temporary storage tank 30, and the air vent pipe 50 reaches the junction joint 26.

If the flow cross-sectional area of the outlet 30A in the temporary storage tank 30 is A1, the sum of the flow cross-sectional areas of the first horizontal pipes 31A and 31B is A2, the flow cross-sectional area of the second horizontal pipe 44 is A3, and the flow cross-sectional area of the vertical pipe 46 is A4, then the relationship A1>A2>A3>A4 is satisfied. Calculating the cross-sectional areas from the inner diameters of the above-mentioned pipes gives A1≈2206 ^mm2 , A2≈1240 ^mm2 , A3≈707 ^mm2 , and A4≈491 ^mm2 , and the above relationship is satisfied.

When the flow path cross-sectional area is not constant, the flow path cross-sectional area refers to the average flow path cross-sectional area. The flow path cross-sectional area A1 of the outlet 30A refers to the average flow path cross-sectional area of the outlet portion where the cross-sectional area is approximately constant. In Figures 6 and 7, the flow path cross-sectional areas A1 to A4 are illustrated at the position of the inner diameter, but the size of the inner diameter of each tube in the drawings does not necessarily correspond to the size of the inner diameter dimension of each tube described above.

The branch joint 28 and the junction joint 48 of this embodiment are each an example of a pipe joint in the present invention. That is, the pipe connection parts 29A and 49A of this embodiment are each an example of a first pipe connection part in the present invention, and the pipe connection parts 29B and 49B of this embodiment are each an example of a second pipe connection part in the present invention. In addition, the different diameter joint 34 and the second horizontal pipe 44 of this embodiment are each an example of a first tubular body in the present invention, and the first horizontal pipes 42A and 42B are each an example of a second tubular body in the present invention. In addition, when the different diameter joint 34 is not used, the cylindrical part constituting the outlet 30A is an example of a first tubular body. Furthermore, the flow direction of the fluid (wastewater) in this invention is the wastewater inflow direction F1 in the case of the branch joint 28, and the wastewater outflow direction F2 in the case of the junction joint 48.

(effect)
The present embodiment is configured as described above, and its operation will be described below. In the piping structure 20 according to the present embodiment, by draining water from the temporary storage tank 30 through the first horizontal pipes 31A and 31B, a larger amount of wastewater can be treated compared to a configuration in which only one horizontal pipe is connected. This makes it possible to prevent wastewater from overflowing the plumbing fixture 12 located upstream of the temporary storage tank 30. Even if a large amount of wastewater is discharged from the bathtub 12A at once, the wastewater is quickly discharged because it is treated by the first horizontal pipes 31A and 31B.

The wastewater flowing through the first horizontal pipes 31A and 31B merges into one at the junction joint 48, increasing the flow rate of the second horizontal pipe 44 and quickly filling the drop-down section from the second horizontal pipe 44 to the vertical pipe 46. This shortens the siphoning time.
In particular, since the flow passage cross-sectional area of each part of the piping structure 20 is set to A1>A2>A3>A4, the flow rate of the second horizontal pipe 44 can be increased to quickly cause the drop-down part from the second horizontal pipe 44 to the vertical pipe 46 to be filled with water, thereby further shortening the siphoning time.

In addition, even if dirt accumulates or foreign matter accumulates in one of the first horizontal pipes, 31A or 31B, the wastewater can be discharged from the other horizontal pipe, 31A or 31B, reducing the risk of being unable to drain the water.

Furthermore, by using a pipe body with a nominal diameter of 25J, which is a common size, for the first horizontal pipes 31A and 31B, conventional products can be used as piping fixing devices, etc.

In addition, when the second horizontal pipe 44 and the vertical pipe 46 are rigid polyvinyl chloride pipes, the piping structure can be constructed more inexpensively than when the second horizontal pipe 44 and the vertical pipe 46 are made of polybutene pipes.

In the piping structure 20, the temporary storage tank 30 and the first horizontal pipes 31A and 31B are connected via a branch joint 28, so that the structure around the outlet 30A of the temporary storage tank 30 can be simplified compared to, for example, a configuration in which the first horizontal pipes 31A and 31B are directly connected to the temporary storage tank 30. Specifically, since there is no need to provide an outlet for the first horizontal pipes 31A and 31B in the temporary storage tank 30, the structure around the outlet 30A of the temporary storage tank 30 is simplified, and further, the formability of the temporary storage tank 30 is improved.

In the piping structure 20, the positions of the pipe connections 29A, 29B of the branch joint 28 in the wastewater inflow direction F1 are different from each other, and parts of the outer peripheries of the pipe connections 29A, 29B overlap with each other in the wastewater inflow direction F1. Therefore, for example, the pipe connections 29A, 29B do not overlap with each other in the wastewater inflow direction F1. In other words, the size of the branch joint 28 can be made smaller than in a configuration in which the pipe connections 29A, 29B are spaced apart in a direction perpendicular to the wastewater inflow direction F1.
In addition, the positions of the pipe connections 49A, 49B of the junction joint 48 in the drainage outflow direction F2 are different, and parts of the outer peripheries of the pipe connections 49A, 49B overlap with each other in the drainage outflow direction F2. For this reason, for example, the pipe connections 49A, 49B do not overlap with each other in the drainage outflow direction F2. In other words, the size of the junction joint 48 can be made smaller than in a configuration in which the pipe connections 49A, 49B are spaced apart in a direction perpendicular to the drainage outflow direction F2.

In addition, the distance between the first horizontal pipes 31A, 31B connected to the piping connections 29A, 29B of the branch joint 28 and the piping connections 49A, 49B of the junction joint 48, respectively, can be reduced. This allows the arrangement pitch of the first horizontal pipes 31A, 31B to be narrowed when laying them, improving design freedom during construction.

In addition, the wastewater in the temporary storage tank 30 flows through the straight pipe section 28A of the branch joint 28 to the first horizontal pipe 31A, and then through the branch pipe section 28B to the first horizontal pipe 31B. Here, in the straight pipe section 28A of the branch joint 28, the wastewater in the temporary storage tank 30 flows linearly, so there is little decrease in flow rate, and the part between the junction joint 48 and the vertical pipe 46, where the second horizontal pipe 44 drops into the vertical pipe 46, can be filled up quickly. This shortens the siphoning time.

In the piping structure 20, wastewater flows from the straight pipe section 28A of the branch joint 28 to the branch pipe section 48B of the junction joint 48 through the first horizontal pipe 31A. Also, wastewater flows from the branch pipe section 28B of the branch joint 28 to the straight pipe section 48A of the junction joint 48 through the first horizontal pipe 31B. Therefore, the difference in flow rate that occurs at the branch joint 28 is offset at the junction joint 48. This suppresses flow bias in the first horizontal pipes 31A and 31B, and allows the wastewater to quickly flow from the second horizontal pipe 44 to the drop section into the vertical pipe 46.

In the piping structure 20, parts of the outer periphery of the piping connection parts 29A and 29B overlap each other in the drainage inflow direction F1, so the angle between the pipe axis direction of the straight pipe section 28A and the pipe axis direction of the branch pipe section 28B can be made small, and the drainage resistance in the branch pipe section 28B can be reduced. In addition, parts of the outer periphery of the piping connection parts 49A and 49B overlap each other in the drainage outflow direction F2, so the angle between the pipe axis direction of the straight pipe section 48A and the pipe axis direction of the branch pipe section 48B can be made small, and the drainage resistance in the branch pipe section 48B can be reduced.

As described above, according to this embodiment, in a structure in which multiple siphon drain pipes are provided in the temporary storage tank 30, it is possible to shorten the siphon force generation time while ensuring the amount of drainage treatment.

[Other embodiments]
An example of an embodiment of the present invention has been described above, but the embodiment of the present invention is not limited to the above, and it goes without saying that various modifications can be made without departing from the spirit and scope of the present invention.

In the above embodiment, as shown in FIG. 4, pipe connection portion 29A is located downstream of pipe connection portion 29B, but the present invention is not limited to this configuration. As shown in FIG. 8, pipe connection portion 29B may be located downstream of pipe connection portion 29A. Similarly, for junction joint 48, pipe connection portion 49B may be located upstream of pipe connection portion 49A.

In the above embodiment, the branch joint 28 has a straight pipe section 28A and a branch pipe section 28B, but the branch type of the branch joint 28 is not limited to this and can be any type. For example, as shown in Figures 9 to 12, a Y-shaped branch joint 68 may be used. This branch joint 68 has an upstream main pipe section 68A and branch pipe sections 68B and 68C that branch into two branches. The main pipe section 68A is connected to the outlet 30A. The downstream ends of the branch pipe sections 68B and 68C are connected to the pipe connection sections 69A and 69B, respectively. The pipe connection sections 69A and 69B are located at different positions in the wastewater inflow direction F1. Specifically, the pipe connection section 69B is located downstream of the pipe connection section 69A. The upstream end of the first horizontal pipe 31A is connected to the pipe connection section 69A, and the upstream end of the first horizontal pipe 31B is connected to the pipe connection section 69B. The junction joint 78 also includes a downstream main pipe 78A and two branch pipes 78B and 78C. The second horizontal pipe 44 is connected to the main pipe 78A. The upstream ends of the branch pipes 78B and 78C are connected to the pipe connections 79B and 79A, respectively. The pipe connections 79A and 79B are located at different positions in the drainage outflow direction F2. Specifically, the pipe connection 79B is located downstream of the pipe connection 79A. The downstream end of the first horizontal pipe 31A is connected to the pipe connection 79A, and the downstream end of the first horizontal pipe 31B is connected to the pipe connection 79B. Even if the shapes of the branch joint and the junction joint are changed in this way, the same effect as in the above embodiment can be obtained.

In addition, in the above-mentioned embodiment, the first horizontal pipes 31A and 31B are connected to the outlet 30A via the different diameter joint 34 and the branch joint 28, but the present invention is not limited to this configuration. The first horizontal pipes 31A and 31B may be directly connected to the temporary storage tank 30 without providing the different diameter joint 34 and the branch joint 28.

20...piping structure, 22...drainage vertical pipe, 28...branch joint, 30...temporary storage tank, 30A...outlet, 31A...first horizontal pipe, 31B...first horizontal pipe, 44...second horizontal pipe, 46...vertical pipe, 48...junction joint (junction), 50...vent pipe

Claims (4)

A plurality of first horizontal pipes connected via a branch joint to the downstream side of a temporary storage tank provided in the drainage system for discharging wastewater discharged from the temporary storage tank in a horizontal direction;
A junction portion that merges the plurality of first horizontal pipes into one;
A second horizontal pipe connected to the downstream side of the confluence and discharging the combined wastewater in a horizontal direction;
A vertical pipe connected to the downstream side of the second horizontal pipe and causing the wastewater to flow downward to generate a siphon force in the first horizontal pipe and the second horizontal pipe ;
Equipped with
The branch joint includes a plurality of pipe connection portions to which the upstream ends of the plurality of first horizontal pipes are respectively connected,
The plurality of pipe connection portions are located at different positions in the wastewater inflow direction in the branch joint, and adjacent pipe connection portions have portions of their outer circumferences overlapping each other in the wastewater inflow direction,
The inner diameter of the first horizontal pipe is smaller than the inner diameter of the second horizontal pipe,
A piping structure in which the flow path cross-sectional area of the outlet of the temporary storage tank is A1, the sum of the flow path cross-sectional areas of the multiple first horizontal pipes is A2, the flow path cross-sectional area of the second horizontal pipe is A3, and the flow path cross-sectional area of the vertical pipe is A4, satisfying the relationship A1>A2>A3>A4 . The junction is a junction joint,
The junction joint includes a plurality of pipe connection portions to which downstream ends of the plurality of first horizontal pipes are respectively connected,
The piping structure according to claim 1 , wherein the plurality of pipe connections are located at different positions in the wastewater outflow direction at the junction joint, and adjacent pipe connections have portions of their outer peripheries overlapping in the wastewater inflow direction. the branch joint includes a straight pipe section connected to the temporary storage tank and extending straight, and a branch pipe section branching from the middle of the straight pipe section and having a portion extending obliquely with respect to a pipe axis direction of the straight pipe section,
The piping structure according to claim 1 or 2, further comprising the piping connection portion provided at a downstream end of the straight pipe portion and a downstream end of the branch pipe portion, respectively. the junction joint has a straight pipe section extending straight and a branch pipe section branching from the middle of the straight pipe section and having a portion extending obliquely with respect to a pipe axis direction of the straight pipe section,
The pipe connection portion is provided at an upstream end of the straight pipe portion and an upstream end of the branch pipe portion,
The piping structure according to claim 3 , wherein a downstream end of the first horizontal pipe connected to the straight pipe section of the branch joint is connected to the straight pipe section of the junction joint.