Socket, piping structure, and piping member

Abstract

To provide a socket, a piping structure, and piping members allowing rainwater to be stably confluent to a main pipe from a branch pipe without any change in a diameter of the main pipe.SOLUTION: A socket 6 is provided with: an outer side member 61 in a cylindrical shape having a first opening 611 connected to a confluent part 43 of a main pipe 4 as a passage to discharge rain water from a first discharge opening 31b by using a siphon phenomenon and a second opening 612 connected to a branch pipe 5 as a passage to flow rain water from a second discharge opening 32b through the confluent part 43 to the main pipe 4; an inner side member 64 having an inner side passage 640 connecting the first opening 611 and the second opening 612 inside of the outer side member 61. A size of the inner side passage 640 becomes larger from the first opening 611 toward the second opening 612.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to sockets, piping structures, and piping members.

Background Art

[0002] Patent Document 1 discloses a rainwater drainage piping structure. The rainwater drainage piping structure disclosed in Patent Document 1 includes a siphon type drainage member arranged on an upper floor, a main pipe through which rainwater flowing in from the siphon type drainage member flows downward from the upper floor to a lower floor, and a branch pipe connected to a confluence portion located in the middle in the height direction of the main pipe and allowing drainage to flow in from the outside to the confluence portion. The main pipe includes a first vertical pipe arranged on the upper side and a curing pipe arranged on the lower side of the first vertical pipe and having a larger flow passage area than the first vertical pipe.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Patent Document 1 describes that when applying the siphon phenomenon to drain rainwater, it provides a rainwater drainage piping structure capable of stably merging the drainage from the branch pipe into the main pipe at the confluence portion.

[0005] In the rainwater drainage pipe structure disclosed in Patent Document 1, since the main pipe is arranged below the first vertical pipe and is provided with a curing pipe having a larger flow cross-sectional area than the first vertical pipe, the main pipe becomes thicker on the downstream side. The construction of the rainwater drainage pipe structure disclosed in Patent Document 1 requires the preparation of pipes and related members with different diameters, which is time-consuming. Since it is necessary to use a pipe with a larger diameter on the downstream side of the main pipe than on the upstream side, it costs more than using a pipe with the same diameter as the upstream side on the downstream side of the main pipe, and generally, it is likely to be judged that the aesthetics are poor because the main pipe becomes thicker on the downstream side.

[0006] The present disclosure provides a socket, a pipe structure, and a pipe member that can stably merge rainwater from a branch pipe into the main pipe without changing the diameter of the main pipe.

Means for Solving the Problems

[0007] A socket according to one aspect of the present disclosure includes a cylindrical outer member having a first opening fluidly connected to a confluence portion of a main pipe for draining rainwater by a siphon phenomenon from a first drain opening, and a second opening fluidly connected to a branch pipe for allowing rainwater from a second drain opening to flow into the main pipe from the confluence portion, and an inner member inside the outer member and having an inner flow path connecting the first opening and the second opening. The size of the inner flow path increases from the first opening toward the second opening.

[0008] A pipe structure according to one aspect of the present disclosure includes the above socket, a drain for generating a siphon phenomenon disposed at a first drain opening, a main pipe, and a branch pipe.

[0009] A pipe member according to one aspect of the present disclosure is a pipe member constituting a part of a pipe structure including a main pipe for draining rainwater by a siphon phenomenon from a first drain opening and a branch pipe for allowing rainwater from a second drain opening to flow into the main pipe from a confluence portion of the main pipe, and includes a cylindrical outer member having a first opening facing the downstream side of the branch pipe and a second opening facing the upstream side of the branch pipe, and an inner member inside the outer member and having an inner flow path connecting the first opening and the second opening. The size of the inner flow path increases from the first opening toward the second opening.

Advantages of the Invention

[0010] Aspects of the present disclosure can stably merge rainwater from branch pipes into the main pipe without changing the diameter of the main pipe.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0012] Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, a more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art. Note that the inventors provide the accompanying drawings and the following description so that those skilled in the art can fully understand the present disclosure, and do not intend to limit the subject matter described in the claims thereby.

[0013] Unless otherwise specified, the positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings. Each figure described in the following embodiments is a schematic diagram, and the ratios of the sizes and thicknesses of the respective components in each figure do not necessarily reflect the actual dimensional ratios. Also, the dimensional ratios of the respective elements are not limited to the ratios illustrated in the drawings.

[0014] [1. Embodiment] [1.1 Configuration] FIG. 1 is a schematic diagram of a configuration example of a piping structure 1 according to an embodiment. The piping structure 1 constitutes, for example, a rain gutter system for a building having a plurality of roofs. The rain gutter system receives rainwater from a plurality of roofs of the building and flows it to the sump 21 on the ground 20. The rainwater collected in the sump 21 flows out from the sump 21 through the buried pipe 22 into the rainwater pipe. The building is, for example, a non-residential facility such as a store, office, factory, building, school, welfare facility, or hospital, and a residential facility building such as a detached house, apartment house, or each dwelling unit of a detached house or apartment house. Non-residential facilities also include theaters, cinemas, convention halls, amusement arcades, complex facilities, department stores, hotels, inns, kindergartens, libraries, museums, art galleries, underground shopping streets, stations, and airports, etc. The building may include a plurality of roofs, eaves (small roofs), and a large roof of the building.

[0015] The piping structure 1 in FIG. 1 includes a first eaves gutter 31, a second eaves gutter 32, a main pipe 4, a branch pipe 5, a socket 6, and a connecting pipe 7.

[0016] The first eaves gutter 31 receives, for example, rainwater from the large roof of the building. The first eaves gutter 31 is installed under the large roof of the building. The first eaves gutter 31 has a long barrel shape. The first eaves gutter 31 in FIG. 1 has a bottom wall 31a, and a first drain port 31b is provided in the bottom wall 31a. In FIG. 1, a drain 9 for generating a siphon phenomenon is arranged at the first drain port 31b of the first eaves gutter 31. The drain 9 reduces the generation of vortices and the entrainment of air at the first drain port 31b. The drain 9 has a structure that makes it easier to generate a siphon phenomenon compared to the case where there is no drain 9. Although the drain 9 contributes to the generation of the siphon phenomenon, it is a well-known fact that the generation of the siphon phenomenon is related not only to the drain 9 but also to the structure of the main pipe 4.

[0017] The second eaves gutter 32 receives rainwater from the eaves of the building, for example. The second eaves gutter 32 is installed under the eaves of the building. The second eaves gutter 32 has a long barrel shape. The second eaves gutter 32 in FIG. 1 has a bottom wall 32a, and there is a second drain opening 32b in the bottom wall 32a. In FIG. 1, unlike the first drain opening 31b, a drain 9 for generating a siphon phenomenon is not arranged at the second drain opening 32b of the second eaves gutter 32. However, a drain or the like having a structure that is generally considered not to contribute to the occurrence of the siphon phenomenon may be arranged at the second drain opening 32b.

[0018] The main pipe 4 is installed to drain rainwater by the siphon phenomenon from the first drain opening 31b. The main pipe 4 vertically drains the rainwater from the first drain opening 31b. The main pipe 4 has an upstream end 4a and a downstream end 4b. The upstream end 4a is the end (the upper end in FIG. 1) connected to the first drain opening 31b in the main pipe 4. The downstream end 4b is the end (the lower end in FIG. 1) inserted into the spigot part 21 in the main pipe 4. In FIG. 1, a drain pipe cover 40 is arranged so that rainwater does not flow into the spigot part 21 from the gap between the main pipe 4 and the spigot part 21.

[0019] The main pipe 4 in FIG. 1 includes a first vertical pipe 41, a second vertical pipe 42, and a confluence part 43.

[0020] The first vertical pipe 41 is the upstream part of the main pipe 4. The first vertical pipe 41 has a straight tubular shape. The cross-section perpendicular to the pipe axis of the first vertical pipe 41 is circular. The material of the first vertical pipe 41 is rigid polyvinyl chloride. The dimensions of the first vertical pipe 41, for example, the outer shape and thickness, may be set in accordance with the specifications of the rigid polyvinyl chloride pipe (general) in JIS K 6741 "Rigid Polyvinyl Chloride Pipe". The first vertical pipe 41 is fixed to the wall surface of the building so that the direction of the pipe axis of the first vertical pipe 41 coincides with the vertical direction (the vertical direction). The upper end of the first vertical pipe 41 is the upstream end 4a of the main pipe 4.

[0021] The second vertical pipe 42 is a part on the downstream side of the main pipe 4. The second vertical pipe 42 is straight tubular. The cross-section perpendicular to the pipe axis of the second vertical pipe 42 is circular. The material of the second vertical pipe 42 is rigid polyvinyl chloride. The dimensions of the second vertical pipe 42, for example, the outer shape and thickness, may be set in accordance with the standard of the rigid polyvinyl chloride pipe (general) in JIS K 6741 "Rigid Polyvinyl Chloride Pipe". The second vertical pipe 42 is fixed to the wall surface of the building so that the direction of the pipe axis of the second vertical pipe 42 coincides with the vertical direction (vertical direction). The lower end of the second vertical pipe 42 is the end 4b on the downstream side of the main pipe 4.

[0022] The confluence part 43 is a member for connecting the branch pipe 5 to the middle part of the main pipe 4, that is, a so-called T-shaped pipe (cheese pipe). In the main pipe 4 of FIG. 1, the confluence part 43 is between the first vertical pipe 41 and the second vertical pipe 42. The confluence part 43 includes a first receiving port 43a connected to the lower end of the first vertical pipe 41, a second receiving port 43b connected to the upper end of the second vertical pipe 42, and a branch port 43c. The confluence part 43 in FIG. 1 is T-shaped. The material of the confluence part 43 is rigid polyvinyl chloride. The dimensions of the confluence part 43 may be set in accordance with the "Rigid Vinyl Chloride Pipe Fittings for Outdoor Drainage Facilities (VU Fittings)" of the Vinyl Chloride Pipe and Fittings Association Standard. The confluence part 43 is arranged at a predetermined distance from the first drain port 31b so that rainwater can be drained through the main pipe 4 from the first drain port 31b due to the siphon phenomenon. The predetermined distance is appropriately set in consideration of the pipe diameter of the main pipe 4 and the like.

[0023] In the main pipe 4 of FIG. 1, the diameter (inner diameter and outer diameter) of the first vertical pipe 41 is equal to the diameter (inner diameter and outer diameter) of the second vertical pipe 42. That is, pipe materials corresponding to the same nominal diameter can be used for the first vertical pipe 41 and the second vertical pipe 42.

[0024] The branch pipe 5 is installed to allow rainwater from the second drain port 32b to flow into the main pipe 4 from the confluence part 43. The branch pipe 5 allows rainwater from the second drain port 32b to flow through the main pipe 4 and into the overflow part 21. The branch pipe 5 has an upstream end 5a and a downstream end 5b. The upstream end 5a is the end (the upper end in FIG. 1) of the branch pipe 5 that is connected to the second drain port 32b. The downstream end 5b is the end (the left end in FIG. 1) of the branch pipe 5 that is connected to the confluence part 43.

[0025] The branch pipe 5 in FIG. 1 includes a vertical pipe 51, a horizontal pipe 52, and an elbow 53.

[0026] The vertical pipe 51 is the upstream part of the branch pipe 5. The vertical pipe 51 is straight. The cross-section perpendicular to the axis of the vertical pipe 51 is circular. The material of the vertical pipe 51 is rigid polyvinyl chloride. The dimensions of the vertical pipe 51, such as the outer shape and thickness, may be set in accordance with the standards of the rigid polyvinyl chloride pipe (general) in JIS K 6741 "Rigid Polyvinyl Chloride Pipe". The vertical pipe 51 is arranged such that the direction of the axis of the vertical pipe 51 coincides with the vertical direction (the vertical direction). The upstream end 5a of the branch pipe 5 is the upper end of the vertical pipe 51.

[0027] The horizontal pipe 52 is the downstream part of the branch pipe 5. The horizontal pipe 52 is straight. The cross-section perpendicular to the axis of the horizontal pipe 52 is circular. The material of the horizontal pipe 52 is rigid polyvinyl chloride. The dimensions of the horizontal pipe 52, such as the outer shape and thickness, may be set in accordance with the standards of the rigid polyvinyl chloride pipe (general) in JIS K 6741 "Rigid Polyvinyl Chloride Pipe". The horizontal pipe 52 is arranged such that the direction of the axis of the horizontal pipe 52 coincides with the horizontal direction. The first end (the right end in FIG. 1) of the horizontal pipe 52 is connected to the vertical pipe 51 via the elbow 53, and the second end (the left end in FIG. 1) of the horizontal pipe 52 is connected to the main pipe 4 via the socket 6. The downstream end 5b of the branch pipe 5 is the second end of the horizontal pipe 52.

[0028] The elbow 53 is a member for connecting the vertical pipe 51 and the horizontal pipe 52. The elbow 53 includes a first receiving port 53a connected to the lower end of the vertical pipe 51 and a second receiving port 53b connected to the first end of the horizontal pipe 52. The elbow in Fig. 1 is L-shaped. The material of the elbow 53 is rigid polyvinyl chloride. The dimensions of the elbow 53 may be set in accordance with the standards of JIS K 6739 "Rigid Polyvinyl Chloride Pipe Fittings for Drainage". For example, the elbow 53 in Fig. 1 is a 90° bend elbow (so-called, DL) defined in JIS K 6739.

[0029] In the present embodiment, the branch pipe 5 is configured such that no siphon phenomenon occurs in the rainwater from the second drain port 2b. As an example, in the branch pipe 5, the lengths of the vertical pipe 51 and the horizontal pipe 52 are set to lengths that are not suitable for the occurrence of the siphon phenomenon.

[0030] The socket 6 is used for connecting the main pipe 4 and the branch pipe 5. In the piping structure 1 of Fig. 1, the socket 6 is connected to the branch port 43c of the confluence portion 43 of the main pipe 4 via the connecting pipe 7. In particular, in the present embodiment, the socket 6 is configured to reduce the possibility of rainwater entering from the main pipe 4 into the branch pipe 5 while allowing rainwater to enter from the branch pipe 5 into the main pipe 4.

[0031] In the main pipe 4, when draining rainwater by utilizing the siphon phenomenon, the water pressure of the rainwater flowing through the main pipe 4 becomes higher than when the siphon phenomenon does not occur. Due to such water pressure, the pressure below the confluence part 43 of the main pipe 4 (the second downspout 42) becomes high. As a result, there is a possibility that rainwater flows from the confluence part 43 of the main pipe 4 toward the branch pipe 5, i.e., backflow occurs. When backflow occurs, it becomes difficult to stably merge rainwater from the branch pipe 5 into the main pipe 4. As a countermeasure against such backflow, conventionally, it has been known to make the diameter of the second downspout 42 larger than the diameter of the first downspout 41 (see Patent Document 1). However, in this case, it is necessary to prepare pipes with different diameters for the first downspout 41 and the second downspout 42 and members (increasers, etc.) for connecting the pipes to each other. This may cause an increase in the types and numbers of members required for the construction of the piping structure 1. There are also concerns about an increase in the labor for the construction of the piping structure 1 and an increase in troubles at the construction site. Furthermore, if the diameter of the main pipe 4 changes in the middle, it is likely to be judged that the aesthetics are poor.

[0032] In the piping structure 1, by providing the socket 6, rainwater can be stably merged from the branch pipe 5 into the main pipe 4 without changing the diameter of the main pipe 4.

[0033] Hereinafter, the socket 6 will be described in more detail with reference to FIGS. 2 to 6.

[0034] FIG. 2 is a perspective view of a configuration example of the socket 6 of the piping structure 1, and FIG. 3 is a perspective view of the socket 6 from a direction different from that of FIG. 2.

[0035] As shown in FIGS. 2 and 3, the socket 6 includes an outer member 61, a first receiving port 62, a second receiving port 63, an inner member 64, and a plurality of ribs 65. In the present embodiment, the outer member 61, the first receiving port 62, the second receiving port 63, the inner member 64, and the plurality of ribs 65 are integrally formed continuously. The material of the socket 6 is rigid polyvinyl chloride.

[0036] The outer member 61 is cylindrical. In particular, in the present embodiment, the outer member 61 is circular cylindrical. The outer peripheral shape and the inner peripheral shape of the outer member 61 in a plane orthogonal to the central axis A1 of the outer member 61 are circular. The outer peripheral shape and the inner peripheral shape of the outer member 61 in a plane orthogonal to the direction of the central axis A1 do not change from the first opening 611 to the second opening 612. The outer member 61 has a first opening 611 and a second opening 612. The first opening 611 and the second opening 612 are at both ends in the direction of the central axis A1 of the outer member 61.

[0037] The first opening 611 is fluidly connected to the confluence portion 43 of the main pipe 4 for draining rainwater by the siphon phenomenon from the first drain port 31b. Here, "the first opening 611 is fluidly connected to the confluence portion 43 of the main pipe 4" means that the first opening 611 is connected to the confluence portion 43 of the main pipe 4 so that fluid can flow in and out between the confluence portion 43 of the main pipe 4 and the first opening 611. In FIG. 1, the first opening 611 is indirectly connected to the branch port 43c of the confluence portion 43 via the connection pipe 7.

[0038] The second opening 612 is fluidly connected to the branch pipe 5 that allows rainwater from the second drain port 32b to flow into the main pipe 4 from the confluence portion 43. Here, "the second opening 612 is fluidly connected to the branch pipe 5" means that the second opening 612 is connected to the branch pipe 5 so that fluid can flow in and out between the branch pipe 5 and the second opening 612. In FIG. 1, the second opening 612 is directly connected to the branch pipe 5.

[0039] The first receiving port 62 is provided for connecting the socket 6 to the confluence portion 43 of the main pipe 4. The first receiving port 62 is provided at the end of the outer member 61 on the first opening 611 side. FIG. 4 is a plan view of the socket 6 on the first opening 611 side. As shown in FIG. 4, the first receiving port 62 is cylindrical and surrounds the first opening 611 of the outer member 61. In FIG. 4, the outer diameter of the first receiving port 62 is equal to the outer diameter of the outer member 61.

[0040] The second receiving port 63 is provided to connect the socket 6 to the end portion 5b on the downstream side of the branch pipe 5. The second receiving port 63 is provided at the end portion of the outer member 61 on the side of the second opening 612. FIG. 5 is a plan view of the socket 6 on the side of the second opening 612. As shown in FIG. 5, the second receiving port 63 is cylindrical and surrounds the second opening 612 of the outer member 61. In FIG. 5, the outer diameter of the second receiving port 63 is equal to the outer diameter of the outer member 61.

[0041] FIG. 6 is a cross-sectional view taken along the line A-A of FIG. 4. FIG. 6 shows D, d, and l as the dimensions of the first receiving port 62 and the second receiving port 63 of the socket 6. l is the length of the first receiving port 62 and the second receiving port 63. D is the outer diameter [mm] of the first receiving port 62 and the second receiving port 63. d is the inner diameter [mm] of the first receiving port 62 and the second receiving port 63. The dimensions D1, d, and l of the first receiving port 62 and the second receiving port 63 may be set, for example, in accordance with the standards of JIS K 6739 "Rigid Polyvinyl Chloride Pipe Fittings for Drainage".

[0042] As shown in FIG. 6, the inner member 64 is inside the outer member 61 and has an inner flow path 640 connecting the first opening 611 and the second opening 612. The size of the inner flow path 640 increases from the first opening 611 toward the second opening 612. The inner member 64 is inside the outer member 61 such that an outer flow path 660 connecting the first opening 611 and the second opening 612 is formed between the inner member 64 and the outer member 61. The size of the outer flow path 660 decreases from the first opening 611 toward the second opening 612.

[0043] Hereinafter, the inner member 64 and related configurations will be described in more detail.

[0044] As shown in FIGS. 2 and 3, the inner member 64 is inside the outer member 61. In particular, the central axis A2 of the inner member 64 coincides with the central axis A1 of the outer member 61. The inner member 64 is not in contact with the outer member 61. The inner member 64 is fixed to the outer member 61 by a plurality of ribs 65 provided between the inner member 64 and the outer member 61.

[0045] The plurality of ribs 65 includes a pair of ribs 65 arranged in a direction intersecting the central axis A2 of the inner member 64. In the present embodiment, the pair of ribs 65 are arranged in a direction orthogonal to the central axis A2 of the inner member 64. The pair of ribs 65 extends over the entire length of the inner member 64 in the direction of the central axis A2 of the inner member 64.

[0046] In the present embodiment, the inner member 64 has a hollow frustum shape. A frustum is a shape obtained by removing a cone that shares the apex with and is similar and reduced to the original cone from the original cone. In the present embodiment, the inner member 64 has a hollow circular frustum shape. The outer peripheral shape and the inner peripheral shape of the inner member 64 in a plane orthogonal to the central axis A2 of the inner member 64 are circular. The outer peripheral shape and the inner peripheral shape of the inner member 64 in a plane orthogonal to the direction of the central axis A2 become larger from the first opening 611 to the second opening 612.

[0047] The inner flow path 640 is defined in the internal space of the inner member 64. The inner flow path 640 has an opening 641 on the first opening 611 side of the outer member 61 and an opening 642 on the second opening 612 side of the outer member 61. In the present embodiment, the inner member 64 has a hollow circular frustum shape. Therefore, the inner flow path 640 is a frustum-shaped space. As understood from FIGS. 4 and 5, the shape of the inner flow path 640 in a plane orthogonal to the central axis A2 of the inner member 64 is circular. The size of the inner flow path 640 in a plane orthogonal to the direction of the central axis A2 of the inner member 64 becomes larger from the first opening 611 to the second opening 612. In the present embodiment, the increment of the size of the inner flow path 640 with respect to the distance from the opening 641 on the first opening 611 side of the inner flow path 640 is constant.

[0048] The outer flow path 660 is defined by the gap between the inner member 64 and the outer member 61. More specifically, the outer flow path 660 is defined by the gap between the outer peripheral surface of the inner member 64 and the inner peripheral surface of the outer member 61. The outer peripheral shape in the plane orthogonal to the direction of the central axis A2 of the inner member 64 increases from the first opening 611 toward the second opening 612. The inner peripheral shape in the plane orthogonal to the direction of the central axis A1 of the outer member 61 does not change from the first opening 611 toward the second opening 612. Therefore, the size of the outer flow path 660 in the plane orthogonal to the direction of the central axis A2 of the inner member 64 becomes smaller from the first opening 611 toward the second opening 612.

[0049] As shown in FIGS. 4 and 5, in the present embodiment, the inner member 64 is fixed to the outer member 61 by a pair of ribs 65 provided between the inner member 64 and the outer member 61. The outer flow path 660 is divided by the pair of ribs 65. In the present embodiment, the outer flow path 660 includes a lower flow path 661 and an upper flow path 662.

[0050] The lower flow path 661 is located below the inner member 64 when the central axis A2 of the inner member 64 is along the horizontal direction. As understood from FIGS. 4 and 5, the shape of the lower flow path 661 in the plane orthogonal to the central axis A2 of the inner member 64 is arc-shaped. The size of the lower flow path 661 in the plane orthogonal to the direction of the central axis A2 of the inner member 64 becomes smaller from the first opening 611 toward the second opening 612. As shown in FIG. 6, the lower flow path 661 has an opening 661a on the first opening 611 side of the outer member 61 and an opening 661b on the second opening 612 side of the outer member 61. In the present embodiment, the increment of the size of the lower flow path 661 with respect to the distance from the opening 661b on the first opening 611 side of the lower flow path 661 is constant.

[0051] The upper flow path 662 is located above the inner member 64 when the central axis A2 of the inner member 64 is aligned horizontally. As can be understood from FIGS. 4 and 5, the shape of the upper flow path 662 in a plane orthogonal to the central axis A2 of the inner member 64 is arc-shaped. The size of the upper flow path 662 in a plane orthogonal to the direction of the central axis A2 of the inner member 64 decreases from the first opening 611 toward the second opening 612. As shown in FIG. 6, the upper flow path 662 has an opening 662a on the first opening 611 side of the outer member 61 and an opening 662b on the second opening 612 side of the outer member 61. In the present embodiment, the increment of the size of the upper flow path 662 with respect to the distance from the opening 662b on the first opening 611 side of the upper flow path 662 is constant.

[0052] The inner member 64 is configured to cause a pressure loss at the opening 641 on the first opening 611 side of the inner flow path 640 so that rainwater flowing from the confluence portion 43 through the first opening 611 into the outer member 61 due to the siphon phenomenon does not pass through the opening 641 on the first opening 611 side of the inner flow path 640. In particular, the inner member 64 is configured to cause a pressure loss by generating a vortex in the rainwater flowing from the confluence portion 43 through the first opening 611 into the outer member 61 due to the siphon phenomenon at the opening 641 on the first opening 611 side of the inner flow path 640. As a result, the possibility that rainwater flowing from the confluence portion 43 through the first opening 611 into the outer member 61 due to the siphon phenomenon enters the branch pipe 5 side through the inner flow path 640 of the socket 6 or the amount of rainwater entering the branch pipe 5 side through the inner flow path 640 of the socket 6 is reduced. That is, the possibility of backflow of rainwater from the main pipe 4 to the branch pipe 5 can be reduced, and rainwater can be stably joined from the branch pipe 5 to the main pipe 4 without changing the diameter of the main pipe 4.

[0053] The inner member 64 is configured to cause a pressure loss at the openings 661b and 662b on the second opening 612 side of the outer flow path 660 so that rainwater flowing from the confluence portion 43 through the first opening 611 into the outer member 61 due to the siphon phenomenon does not pass through the openings 661b and 662b on the second opening 612 side of the outer flow path 660. In particular, the inner member 64 is configured to cause a pressure loss by generating a vortex in the rainwater flowing from the confluence portion 43 through the first opening 611 into the outer member 61 due to the siphon phenomenon at the openings 661b and 662b on the second opening 612 side of the outer flow path 660. As a result, the possibility that rainwater flowing from the confluence portion 43 through the first opening 611 into the outer member 61 due to the siphon phenomenon passes through the inner flow path 640 of the socket 6 and enters the branch pipe 5 side or the amount of rainwater passing through the inner flow path 640 of the socket 6 and entering the branch pipe 5 side is reduced. That is, the possibility of reverse flow of rainwater from the main pipe 4 to the branch pipe 5 can be reduced, and rainwater can be stably joined from the branch pipe 5 to the main pipe 4 without changing the diameter of the main pipe 4.

[0054] FIG. 6 shows d1, d2, and t as the dimensions of the inner member 64. d1 is the diameter [mm] of the opening 641 of the inner flow path 640. d2 is the diameter [mm] of the opening 642 of the inner flow path 640. t is the thickness [mm] of the inner member 64. The thickness [mm] of the inner member 64 is also the distance between the inner peripheral surface and the outer peripheral surface of the inner member 64 in a plane orthogonal to the central axis A2 of the inner member 64. In FIG. 6, d3 is the inner diameter [mm] of the outer member 61. g is the distance [mm] between the end portion of the inner member 64 on the second opening 612 side of the outer member 61 and the outer member 61. As an example, by appropriately setting d1, d2, and t in consideration of the diameter of the main pipe 4, the diameter of the branch pipe 5, the installation environment of the piping structure 1, and the properties of the material of the piping structure 1, etc., it is possible to configure the inner member 64 so as to generate a vortex at the opening 641 on the first opening 611 side of the inner flow path 640 and the openings 661b and 662b on the second opening 612 side of the outer flow path 660.

[0055] Next, the operation of the socket 6 will be described with reference to FIGS. 7 to 10.

[0056] FIG. 7 is an explanatory diagram of a first example of the operation of the socket 6. In the first example, rainwater from the first drain port 31b flows through the main pipe 4 due to the siphon phenomenon, and rainwater W1 branched from the rainwater flowing through the main pipe 4 is about to proceed from the connecting pipe 7 connected to the branch port 43c of the confluence 43 toward the horizontal pipe 52 of the branch pipe 5.

[0057] The socket 6 restricts the flow path of the rainwater W1 that proceeds into the outer member 61 from the first opening 611 of the outer member 61 by means of the inner flow path 640 and the outer flow path 660 (the lower flow path 661 and the upper flow path 662).

[0058] When rainwater from the first drain port 31b flows through the main pipe 4 due to the siphon phenomenon, the inside of the main pipe 4 is filled with the rainwater W1. A part of the rainwater W1 flowing into the outer member 61 from the confluence 43 through the first opening 611 due to the siphon phenomenon heads toward the opening 641 of the inner flow path 640, and the rest heads toward the opening 661a of the lower flow path 661 and the opening 662a of the upper flow path 662 of the outer flow path 640.

[0059] Regarding the rainwater heading toward the inner flow path 640, the cross-section of the flow path of the socket 6 decreases from the first opening 611 of the outer member 61 to the opening 641 of the inner flow path 640. It is generally known as a principle that a sudden change in the cross-section of the flow path causes a vortex. The pressure loss factors in a fluid are roughly classified into vortices and turbulent flows. In the socket 6, the cross-section of the flow path decreases near the opening 641 of the inner flow path 640, so that a vortex E1 is generated in the rainwater W1, and due to the influence of the pressure loss caused thereby, the possibility that the rainwater W1 passes through the opening 641 of the inner flow path 640 or the amount of the rainwater W1 passing through the opening 641 of the inner flow path 640 is reduced. As a result, the possibility of the backflow of rainwater from the main pipe 4 to the branch pipe 5 is reduced. In particular, since the rainwater W1 flows through the main pipe 4 at a relatively high speed due to the influence of the siphon phenomenon, the pressure of the rainwater W1 is high, and a sudden change in the cross-section of the flow path occurs in a short time by the inner flow path 640, so that the vortex E1 that inhibits the flow of the rainwater W1 is likely to be generated.

[0060] Regarding the rainwater flowing toward the outer channel 660, the cross-section of the channel of the socket 6 decreases from the first opening 611 of the outer member 61 to the openings 661b and 662b of the lower channel 661 and the upper channel 662 of the outer channel 660. In the socket 6, the cross-section of the channel decreases in the vicinity of the openings 661b and 662b of the lower channel 661 and the upper channel 662 of the outer channel 660, so that vortices E2 and E3 are generated in the rainwater W1. Due to the influence of the pressure loss caused thereby, the possibility that the rainwater W1 passes through the opening 641 of the inner channel 640 or the amount of the rainwater W1 passing through the opening 641 of the inner channel 640 is reduced. As a result, the possibility of the backflow of the rainwater from the main pipe 4 to the branch pipe 5 is reduced.

[0061] FIG. 8 is an explanatory diagram of a second example of the operation of the socket 6. In the second example, the rainwater W2 from the second drain port 32b is flowing in the branch pipe 5 and is about to proceed from the horizontal pipe 52 of the branch pipe 5 toward the connecting pipe 7. In the second example shown in FIG. 8, the amount of the rainwater W2 is so small that the water level of the rainwater W2 does not reach the inner channel 640. Since the rainwater W2 flows through the lower channel 661 of the socket 6, the cross-section of the channel of the socket 6 hardly changes from the opening 661b of the lower channel 661. Therefore, no vortex that inhibits the flow is generated in the rainwater W2. The rainwater W2 can pass through the lower channel 661 of the socket 6 and reach the confluence 43 of the main pipe 4 through the connecting pipe 7 from the branch pipe 5. The socket 6 can allow the rainwater flowing through the branch pipe 5 to flow into the main pipe 4 from the confluence 43.

[0062] FIG. 9 is an explanatory diagram of a third example of the operation of the socket 6. In the third example, rainwater W3 from the second drain port 32b flows through the branch pipe 5 and is about to proceed from the horizontal pipe 52 of the branch pipe 5 toward the connecting pipe 7. In the third example shown in FIG. 9, the amount of rainwater W3 is larger than the amount of rainwater W2 in FIG. 8. The water level of the rainwater W3 reaches the inner flow path 640 but does not reach the upper flow path 662. The rainwater W3 flows through the lower flow path 661 and the inner flow path 640 of the socket 6. The size of the inner flow path 640 is larger on the side of the second opening 612 than on the side of the first opening 611 of the outer member 61. At the water level of the rainwater W3, the cross section of the flow path of the socket 6 hardly changes. Therefore, no vortex that obstructs the flow is generated in the rainwater W3. The rainwater W3 can pass through the lower flow path 661 and the inner flow path 640 of the socket 6 and reach the confluence 43 of the main pipe 4 through the connecting pipe 7 from the branch pipe 5. The socket 6 can cause the rainwater W3 flowing through the branch pipe 5 to flow into the main pipe 4 from the confluence 43.

[0063] FIG. 10 is an explanatory diagram of a fourth example of the operation of the socket 6. In the fourth example, rainwater W4 from the second drain port 32b flows through the branch pipe 5 and is about to proceed from the horizontal pipe 52 of the branch pipe 5 toward the connecting pipe 7. In the fourth example shown in FIG. 10, the amount of rainwater W4 is larger than the amount of rainwater W3 in FIG. 9. The water level of the rainwater W4 reaches the upper flow path 662. The rainwater W4 flows through the lower flow path 661, the inner flow path 640, and the upper flow path 662 of the socket 6. At the water level of the rainwater W4, the cross section of the flow path of the socket 6 hardly changes. Therefore, no vortex that obstructs the flow is generated in the rainwater W4. The rainwater W4 can pass through the lower flow path 661, the inner flow path 640, and the upper flow path 662 of the socket 6 and reach the confluence 43 of the main pipe 4 through the connecting pipe 7 from the branch pipe 5. The socket 6 can cause the rainwater W4 flowing through the branch pipe 5 to flow into the main pipe 4 from the confluence 43.

[0064] Regarding the second to fourth examples in FIGS. 8 to 10, in the branch pipe 5, no siphon phenomenon occurs, so the pressures of the rainwaters W2, W3, and W4 are low, and the socket 6 prevents a sudden change in the cross section of the flow path in a short time. Therefore, no vortex that obstructs the flow of the rainwaters W2, W3, and W4 is generated.

[0065] In this way, by providing the socket 6 with the inner member 64, while allowing the rainwater flowing through the branch pipe 5 to flow into the main pipe 4 from the confluence part 43, the possibility that the rainwater flowing through the main pipe 4 flows into the branch pipe 5 from the confluence part 43 due to the siphon phenomenon is reduced.

[0066] The connecting pipe 7 is used for connecting the main pipe 4 and the socket 6. The connecting pipe 7 in Fig. 1 is arranged between the branch port 43c of the confluence part 43 of the main pipe 4 and the first receiving port 62 of the socket 6. The connecting pipe 7 is straight tubular. The cross-section orthogonal to the pipe axis of the connecting pipe 7 is circular. The material of the connecting pipe 7 is rigid polyvinyl chloride. The dimensions of the connecting pipe 7, for example, the outer shape and the thickness, may be set in accordance with the standards of the rigid polyvinyl chloride pipe (general) of JIS K 6741 "Rigid Polyvinyl Chloride Pipe". The connecting pipe 7 is arranged such that the direction of the pipe axis of the connecting pipe 7 coincides with the horizontal direction.

[0067] [1.2 Effects, etc.] The socket 6 described above includes a cylindrical outer member 61 having a first opening 611 that is fluidly connected to the confluence part 43 of the main pipe 4 for draining rainwater by the siphon phenomenon from the first drain port 31b, and a second opening 612 that is fluidly connected to the branch pipe 5 for allowing the rainwater from the second drain port 32b to flow into the main pipe 4 from the confluence part 43, and an inner member 64 inside the outer member 61 and having an inner flow path 640 connecting the first opening 611 and the second opening 612. The size of the inner flow path 640 increases from the first opening 611 toward the second opening 612. This configuration can stably merge rainwater from the branch pipe 5 into the main pipe 4 without changing the diameter of the main pipe 4.

[0068] In the socket 6, the inner member 64 is inside the outer member 61 such that an outer flow path 660 connecting the first opening 611 and the second opening 612 is formed between the inner member 64 and the outer member 61. The size of the outer flow path 660 decreases from the first opening 611 toward the second opening 612. This configuration can more stably merge rainwater from the branch pipe 5 into the main pipe 4 without changing the diameter of the main pipe 4.

[0069] In socket 6, the inner member 64 has a hollow frustum shape. The inner flow path 640 is defined by the internal space of the inner member 64. The outer flow path 660 is defined by the gap between the inner member 64 and the outer member 61. With this configuration, rainwater can be made to merge more stably from the branch pipe 5 into the main pipe 4 without changing the diameter of the main pipe 4.

[0070] In socket 6, the outer flow path 660 includes a lower flow path 661 that is located below the inner member 64 when the central axis A2 of the inner member 64 is aligned along the horizontal direction. With this configuration, rainwater can be stably merged from the branch pipe 5 into the main pipe 4 even when the amount of rainwater flowing through the branch pipe 5 is small.

[0071] In socket 6, the outer flow path 660 includes an upper flow path 662 that is located above the inner member 64 when the central axis A2 of the inner member 64 is aligned along the horizontal direction. With this configuration, the possibility of rainwater overflowing from the branch pipe 5 can be reduced even when the amount of rainwater flowing through the branch pipe 5 increases.

[0072] In socket 6, the inner member 64 is configured to cause a pressure loss at the openings 661b, 662b on the second opening 612 side of the outer flow path 660 so that rainwater flowing from the confluence part 43 through the first opening 611 into the outer member 61 does not pass through the openings 661b, 662b on the second opening 612 side of the outer flow path 660 due to the siphon phenomenon. With this configuration, the possibility of rainwater flowing back from the main pipe 4 into the branch pipe 5 can be reduced, and rainwater can be stably merged from the branch pipe 5 into the main pipe 4 without changing the diameter of the main pipe 4.

[0073] In socket 6, the inner member 64 is configured to cause a pressure loss by generating a vortex in the rainwater flowing from the confluence part 43 through the first opening 611 into the outer member 61 at the openings 661b, 662b on the second opening 612 side of the outer flow path 660 due to the siphon phenomenon. With this configuration, the possibility of rainwater flowing back from the main pipe 4 into the branch pipe 5 can be reduced, and rainwater can be stably merged from the branch pipe 5 into the main pipe 4 without changing the diameter of the main pipe 4.

[0074] In socket 6, the inner member 64 is configured to cause a pressure loss at the opening 641 on the first opening 611 side of the inner flow path 640 so that rainwater flowing from the confluence part 43 to the outer member 61 through the first opening 611 due to the siphon phenomenon does not pass through the opening 641 on the first opening 611 side of the inner flow path 640. This configuration can reduce the possibility of rainwater flowing back from the main pipe 4 to the branch pipe 5, and rainwater can be stably joined from the branch pipe 5 to the main pipe 4 without changing the diameter of the main pipe 4.

[0075] In socket 6, the inner member 64 is configured to cause a pressure loss by generating a vortex in the rainwater flowing from the confluence part 43 to the outer member 61 through the first opening 611 due to the siphon phenomenon at the opening 641 on the first opening 611 side of the inner flow path 640. This configuration can reduce the possibility of rainwater flowing back from the main pipe 4 to the branch pipe 5, and rainwater can be stably joined from the branch pipe 5 to the main pipe 4 without changing the diameter of the main pipe 4.

[0076] Socket 6 further includes a plurality of ribs 65 that fix the inner member 64 to the outer member 61 with respect to the outer member 61. This configuration can reduce the possibility of the inner member 64 being damaged when rainwater passes through the outer member 61.

[0077] In socket 6, the plurality of ribs 65 includes a pair of ribs 65 arranged in a direction intersecting the central axis A2 of the inner member 64. This configuration can reduce the possibility of the inner member 64 being damaged when rainwater passes through the outer member 61.

[0078] The above-described piping structure 1 includes the above-described socket 6, a drain 9 for generating a siphon phenomenon disposed at the first drain port 31b, a main pipe 4, and a branch pipe 5. This configuration can stably join rainwater from the branch pipe 5 to the main pipe 4 without changing the diameter of the main pipe 4.

[0079] [2. Modification Example] Embodiments of the present disclosure are not limited to the above embodiments. The above embodiments can be variously modified according to design and the like as long as the problems of the present disclosure can be achieved. Below, modification examples of the above embodiments are listed. The modification examples described below can be applied in appropriate combinations.

[0080] In one modification example, the shape and size of the inner member 64 may be different from those of the above embodiment. For example, unlike the above embodiment, the inner member 64 may be in the shape of a hollow frustum of a pyramid. The shape of the inner member 64 or the inner flow path 640 in a plane orthogonal to the central axis A2 of the inner member 64 may be polygonal instead of circular. In the above embodiment, in the cross section of the inner member 64 in a plane including the central axis A2 of the inner member 64, the outer surface and the inner surface of the inner member 64 are linear, but in the modification example, they may be curved or polygonal.

[0081] In one modification example, the outer flow path 660 is not limited to the lower flow path 661 or the upper flow path 662. The outer flow path 660 only needs to be configured to connect the first opening 611 and the second opening 612 between the inner member 64 and the outer member 61. The outer flow path 660 does not necessarily have to include both the lower flow path 661 and the upper flow path 662. The outer flow path 660 may be composed of only the lower flow path 661. The outer flow path 660 is not essential. For example, the inner member 64 may be inside the outer member 61 so that an outer flow path 660 connecting the first opening 611 and the second opening 612 is not formed between the inner member 64 and the outer member 61. As an example, the inner member 64 may be provided so as to protrude from the inner peripheral surface of the outer member 61.

[0082] In one modification example, the plurality of ribs 65 are not limited to a pair of a plurality of ribs 65 as shown in FIGS. 4 and 5. The number, shape, and arrangement of the plurality of ribs 65 are not particularly limited as long as the inner member 64 can be fixed to the outer member 61 between the outer member 61 and the inner member 64. The socket 6 may include a single rib 65 instead of the plurality of ribs 65.

[0083] In a modified example, the inner member 64 may include a plurality of inner flow paths 640. In a modified example, the socket 6 may include a plurality of inner members 64. The socket 6 may include one or more inner members 64 having one or more inner flow paths 640. The socket 6 may be configured by the inner member 64 to reduce the possibility that rainwater flowing through the main pipe 4 flows from the confluence portion 43 into the branch pipe 5 due to the siphon phenomenon while allowing the rainwater flowing through the branch pipe 5 to flow into the main pipe 4 from the confluence portion 43.

[0084] In a modified example, the outer member 61, the first receiving port 62, the second receiving port 63, the inner member 64, and the plurality of ribs 65 may not be formed continuously and integrally. In particular, the outer member 61 and the inner member 64 may be separate bodies. The outer member 61 and the inner member 64 may be mechanically coupled by assembly or the like. The material of the outer member 61 and the material of the inner member 64 may be different.

[0085] In a modified example, at least one of the materials of the main pipe 4, the branch pipe 5, the socket 6, and the connecting pipe 7 does not necessarily have to be rigid polyvinyl chloride. The materials of the main pipe 4, the branch pipe 5, the socket 6, and the connecting pipe 7 may be determined according to the requirements for the piping structure 1. For example, they may be synthetic resins such as polyethylene.

[0086] In a modified example, d, D, and l of the socket 6 do not necessarily have to be set in accordance with the provisions of JIS K 6741.

[0087] In a modified example, the piping structure 1 does not necessarily have to include the first eaves trough 31. For example, when the building 10 has a structure with a drop opening such as a balcony, the main pipe 4 may be connected to the drop opening of the building 10.

[0088] In a modified example, the piping structure 1 does not necessarily have to include the second eaves gutter 32. For example, when the building 10 has a structure with a drop opening such as a balcony, the branch pipe 5 may be connected to the drop opening of the building 10. The piping structure 1 may correspond to a plurality of second drop openings 2b. In the piping structure 1, a plurality of branch pipes may be connected to one or more confluence parts of the main pipe. In this case, a socket 6 may be arranged between at least one of the plurality of branch pipes and the main pipe.

[0089] In a modified example, the main pipe 4 may have a configuration different from that in the example of the above-described embodiment. In addition to the first vertical gutter 41, the second vertical gutter 42, and the confluence part 43, the main pipe 4 may have other piping members such as other downspouts. In the main pipe 4, the number of the first vertical gutters 41, the number of the second vertical gutters 42, and the number of the confluence parts 43 are not particularly limited either.

[0090] In a modified example, the branch pipe 5 may have a configuration different from that in the example of the above-described embodiment. In addition to the vertical pipe 51, the horizontal pipe 52, and the elbow 53, the branch pipe 5 may have other piping members. In the branch pipe 5, the number of the vertical pipes 51, the number of the horizontal pipes 52, and the number of the elbows 53 are not particularly limited either.

[0091] In a modified example, the connecting pipe 7 may have a configuration different from that in the example of the above-described embodiment. In some cases, the connecting pipe 7 may be omitted.

[0092] In a modified example, the piping structure 1 can include, in addition to or instead of the socket 6, a piping member having the same function as the socket 6. Such a piping member constitutes a part of the piping structure 1 including the main pipe 4 for draining rainwater by the siphon phenomenon from the first drain port 31b and the branch pipe 5 for allowing rainwater from the second drain port 32b to flow into the main pipe 4 from the confluence portion 43 of the main pipe 4. The piping member includes a cylindrical outer member having a first opening facing the downstream side of the branch pipe 5 and a second opening facing the upstream side of the branch pipe 5, and an inner member inside the outer member and having an inner flow path connecting the first opening and the second opening. The size of the inner flow path increases from the first opening toward the second opening. The configurations of the outer member and the inner member of the piping member may be the same as those of the outer member 61 and the inner member 64 of the socket 6. For example, the piping member may be a cheese pipe such as the confluence portion 43. In this case, the outer member of the piping member is a part of the cheese pipe, particularly, a portion corresponding to the horizontal pipe branched from the vertical pipe in the cheese pipe. For example, the piping member may be the connecting pipe 7 or the horizontal pipe 52. In this case, the outer member of the piping member may be a part of the connecting pipe 7 or the horizontal pipe 52. By using such a piping member, rainwater can be stably joined from the branch pipe 5 to the main pipe 4 without changing the diameter of the main pipe 4.

[0093] [3. Aspect] As is clear from the above-described embodiments and modified examples, the present disclosure includes the following aspects. Hereinafter, for the sole purpose of clarifying the correspondence with the embodiments, reference numerals are given in parentheses. Note that, for the sake of readability of the text, the description of the reference numerals in parentheses may be omitted after the first time.

[0094] The first aspect is a socket (6), which includes a first opening (611) fluidly connected to a confluence part (43) of a main pipe (4) for draining rainwater by siphon phenomenon from a first drain opening (31b), and a second opening (612) fluidly connected to a branch pipe (5) for allowing rainwater from a second drain opening (32b) to flow into the main pipe (4) from the confluence part (43). The socket also includes a cylindrical outer member (61) having these openings, and an inner member (64) inside the outer member (61) and having an inner flow path (640) connecting the first opening (611) and the second opening (612). The size of the inner flow path (640) increases from the first opening (611) toward the second opening (612). This aspect enables rainwater to stably merge from the branch pipe (5) into the main pipe (4) without changing the diameter of the main pipe (4).

[0095] The second aspect is a socket (6) based on the first aspect. In the second aspect, the inner member (64) is inside the outer member (61) such that an outer flow path (660) connecting the first opening (611) and the second opening (612) is formed between the inner member (64) and the outer member (61). The size of the outer flow path (660) decreases from the first opening (611) toward the second opening (612). This aspect enables rainwater to more stably merge from the branch pipe (5) into the main pipe (4) without changing the diameter of the main pipe (4).

[0096] The third aspect is a socket (6) based on the second aspect. In the third aspect, the inner member (64) is in a hollow frustum shape. The inner flow path (640) is defined by the internal space of the inner member (64). The outer flow path (660) is defined by the gap between the inner member (64) and the outer member (61). This aspect enables rainwater to more stably merge from the branch pipe (5) into the main pipe (4) without changing the diameter of the main pipe (4).

[0097] The fourth aspect is the socket (6) based on the second or third aspect. In the fourth aspect, the outer flow path (660) includes a lower flow path (661) located below the inner member (64) when the central axis (A2) of the inner member (64) is along the horizontal direction. This aspect can stably merge rainwater from the branch pipe (5) into the main pipe (4) even when the amount of rainwater flowing through the branch pipe (5) is small.

[0098] The fifth aspect is the socket (6) based on the fourth aspect. In the fifth aspect, the outer flow path (660) includes an upper flow path (662) located above the inner member (64) when the central axis (A2) of the inner member (64) is along the horizontal direction. This aspect can reduce the possibility of rainwater overflowing from the branch pipe (5) even when the amount of rainwater flowing through the branch pipe (5) increases.

[0099] The sixth aspect is the socket (6) based on any one of the second to fifth aspects. In the sixth aspect, the inner member (64) causes a pressure loss at the openings (661b, 662b) on the second opening (612) side of the outer flow path (660) so that rainwater flowing from the confluence part (43) through the first opening (611) into the outer member (61) does not pass through the openings (661b, 662b) on the second opening (612) side of the outer flow path (660) due to the siphon phenomenon. This aspect can reduce the possibility of rainwater flowing back from the main pipe (4) to the branch pipe (5), and can stably merge rainwater from the branch pipe (5) into the main pipe (4) without changing the diameter of the main pipe (4).

[0100] The seventh aspect is the socket (6) based on the sixth aspect. In the seventh aspect, the inner member (64) is configured to cause a pressure loss by generating a vortex in the rainwater flowing from the confluence part (43) through the first opening (611) to the outer member (61) at the openings (661b, 662b) on the second opening (612) side of the outer flow path (660) due to the siphon phenomenon. This aspect can reduce the possibility of rainwater flowing backward from the main pipe (4) to the branch pipe (5), and rainwater can be stably joined from the branch pipe (5) to the main pipe (4) without changing the diameter of the main pipe (4).

[0101] The eighth aspect is the socket (6) based on any one of the first to seventh aspects. In the eighth aspect, the inner member (64) is configured to cause a pressure loss in the rainwater flowing from the confluence part (43) through the first opening (611) to the outer member (61) due to the siphon phenomenon, so that the rainwater does not pass through the opening (641) on the first opening (611) side of the inner flow path (640). This aspect can reduce the possibility of rainwater flowing backward from the main pipe (4) to the branch pipe (5), and rainwater can be stably joined from the branch pipe (5) to the main pipe (4) without changing the diameter of the main pipe (4).

[0102] The ninth aspect is the socket (6) based on the eighth aspect. In the ninth aspect, the inner member (64) is configured to cause a pressure loss by generating a vortex in the rainwater flowing from the confluence part (43) through the first opening (611) to the outer member (61) at the opening (641) on the first opening (611) side of the inner flow path (640) due to the siphon phenomenon. This aspect can reduce the possibility of rainwater flowing backward from the main pipe (4) to the branch pipe (5), and rainwater can be stably joined from the branch pipe (5) to the main pipe (4) without changing the diameter of the main pipe (4).

[0103] Aspect 10 is a socket (6) based on any one of Aspects 1 to 9. In Aspect 10, a plurality of ribs (65) for fixing the inner member (64) to the outer member (61) are further provided between the outer member (61) and the inner member (64). This aspect can reduce the possibility of the inner member (64) being damaged when rainwater passes through the outer member (61).

[0104] Aspect 11 is a socket (6) based on Aspect 10. In Aspect 11, the plurality of ribs (65) include a pair of ribs (65) arranged in a direction intersecting the central axis (A2) of the inner member (64). This aspect can reduce the possibility of the inner member (64) being damaged when rainwater passes through the outer member (61).

[0105] Aspect 12 is a piping structure (1), comprising a socket (6) based on any one of Aspects 1 to 11, a drain (9) for generating a siphon phenomenon disposed at the first drain opening (31b), the main pipe (4), and the branch pipe (5). This aspect can stably merge rainwater from the branch pipe (5) into the main pipe (4) without changing the diameter of the main pipe (4).

[0106] Aspect 13 is a piping member (6), which forms a part of a piping structure (1) comprising a main pipe (4) for draining rainwater by siphon phenomenon from a first drain opening (31b), and a branch pipe (5) for allowing rainwater from a second drain opening (32b) to flow into the main pipe (4) from a confluence portion (43) of the main pipe (4). The piping member (6) includes a cylindrical outer member (61) having a first opening (611) facing the downstream side of the branch pipe (5) and a second opening (612) facing the upstream side of the branch pipe (5), and an inner member (64) inside the outer member (61) and having an inner flow path (640) connecting the first opening (611) and the second opening (612). The size of the inner flow path (640) increases from the first opening (611) toward the second opening (612). This aspect can stably merge rainwater from the branch pipe (5) into the main pipe (4) without changing the diameter of the main pipe (4).

[0107] The second to eleventh aspects described above may be combined with the thirteenth aspect. The second to eleventh aspects described above are optional elements.

Industrial Applicability

[0108] The present disclosure is applicable to sockets, piping structures, and piping members. Specifically, the present disclosure is applicable to sockets for connecting branch pipes to a main pipe, piping structures including the main pipe and the branch pipe, and piping members used in the piping structures including the main pipe and the branch pipe.

Explanation of Signs

[0109] 1 Piping structure 31b First drain port 32b Second drain port 4 Main pipe 43 Confluence section 5 Branch pipe 6 Socket 61 Outer member 611 First opening 612 Second opening 64 Inner member 640 Inner flow path 641 Opening 65 Rib 660 Outer flow path 661 Lower flow path 661b Opening 662 Upper flow path 662b Opening A2 Central axis

Claims

1. A cylindrical outer member having a first opening fluidly connected to a junction of a main pipe for draining rainwater by siphon action from a first drain opening, and a second opening fluidly connected to a branch pipe for allowing rainwater from a second drain opening to flow into the main pipe from the junction, an inner member inside the outer member and having an inner flow path connecting the first opening and the second opening, comprising: the size of the inner flow path increasing from the first opening toward the second opening, a socket.

2. The inner member is inside the outer member such that an outer flow path connecting the first opening and the second opening is formed between the inner member and the outer member, the size of the outer flow path decreasing from the first opening toward the second opening, The socket according to claim 1.

3. The inner member is a hollow frustum shape, the inner flow path is defined by an internal space of the inner member, the outer flow path is defined by a gap between the inner member and the outer member, The socket according to claim 2.

4. The outer flow path includes a lower flow path located below the inner member when the central axis of the inner member is along the horizontal direction, The socket according to claim 2 or 3.

5. The outer flow path includes an upper flow path located above the inner member when the central axis of the inner member is along the horizontal direction, The socket according to claim 4.

6. The inner member is configured to cause a pressure loss at an opening on the second opening side of the outer flow path so that rainwater flowing into the outer member from the junction through the first opening due to siphon action does not pass through the opening on the second opening side of the outer flow path, The socket according to any one of claims 2 to 5.

7. The inner member is configured to cause a pressure loss at an opening on the second opening side of the outer flow path by generating a vortex in rainwater flowing into the outer member from the junction through the first opening due to siphon action, The socket according to claim 6.

8. The inner member is configured to cause a pressure loss at an opening on the first opening side of the inner flow path so that rainwater flowing into the outer member from the junction through the first opening due to siphon action does not pass through the opening on the first opening side of the inner flow path, The socket according to any one of claims 1 to 7.

9. The inner member is configured to cause a pressure loss by generating a vortex in the rainwater flowing from the confluence portion through the first opening to the outer member at the opening on the first opening side of the inner flow path due to a siphon phenomenon. The socket according to claim 8.

10. Further comprising a plurality of ribs for fixing the inner member to the outer member between the outer member and the inner member. The socket according to any one of claims 1 to 9.

11. The plurality of ribs include a pair of ribs arranged in a direction intersecting the central axis of the inner member. The socket according to claim 10.

12. The socket according to any one of claims 1 to 11, a drain for generating a siphon phenomenon disposed at the first drain opening, the main pipe, the branch pipe, comprising: a piping structure.

13. A piping member constituting a part of a piping structure including a main pipe for draining rainwater by a siphon phenomenon from a first drain opening and a branch pipe for allowing rainwater from a second drain opening to flow into the main pipe from a confluence portion of the main pipe, a cylindrical outer member having a first opening facing the downstream side of the branch pipe and a second opening facing the upstream side of the branch pipe, an inner member disposed inside the outer member and having an inner flow path connecting the first opening and the second opening, wherein the size of the inner flow path increases from the first opening toward the second opening. A piping member.

Images