Rainwater pipe groove system and siphon inducing component

Abstract

The invention provides a rainwater pipe groove system and a siphon inducing component, which can reduce the influence on the appearance and improve the drainage capacity at the same time. The rainwater pipe groove system (1) constitutes a rainwater flow path (1a), and is provided with: a downpipe (3); a connecting part (9) for connecting a drain opening (2d) of the cornice (2) and an upstream end (3a) of the downpipe (3); and a siphon inducing member (5). The flow path cross-sectional area of the cornice (2) is 11000 mm2 or more. The inner diameter of the downpipe (3) is 67.0 mm or more. The wall thickness of the downpipe (3) is 2.2 mm or more. The siphon inducing member (5) has a cylindrical shape and has a reduced diameter section (52) having a flow path cross-sectional area smaller than that of the connection section (9). The siphon inducing member (5) is located immediately below the connecting part (9) in the flow path (1a).

Description

Technical Field

[0001] The invention relates to a rainwater pipe trough system and a siphon inducing component. Background Art

[0002] Patent document 1 discloses a rainwater trough system that can more reliably generate a siphon phenomenon even in a large rainwater trough system having a reduced diameter portion and stably transmit the generated siphon phenomenon to the upstream portion. The rainwater trough system disclosed in patent document 1 includes an eaves, a downpipe, a connecting joint that is arranged at a position downstream of the eaves and connected to the upper end of the downpipe, and a siphon joint that has a reduced diameter portion and is provided on the downpipe. The flow path cross-sectional area of ​​the eaves is 11000mm 2 In the above, the inner diameter of the downpipe is greater than 65 mm, and the length of the downpipe between the connecting joint and the siphon joint is greater than 1 m.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6835995 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In Patent Document 1, the siphon joint needs to be arranged at a position more than 1 meter below the connection joint. For example, when the rainwater pipe trough system described in Patent Document 1 is applied to a building with an eaves height of 2 meters, the siphon joint is likely to be located at the height of people's sight. That is, the arrangement of the siphon joint can improve the drainage capacity, but there is a concern that the appearance of the rainwater pipe trough system will be negatively affected.

[0008] The present invention provides a rainwater trough system and a siphon inducing member capable of improving drainage capacity while reducing the impact on the appearance.

[0009] Solutions to Solve Problems

[0010] A rainwater pipe trough system according to one embodiment of the present invention is a rainwater pipe trough system that constitutes a flow path for rainwater, wherein the rainwater pipe trough system comprises: a downpipe; a connecting portion that connects a downspout of an eave to an end on the upstream side of the downpipe; and a siphon inducing member, wherein the flow path cross-sectional area of ​​the eave is 11000mm 2 In the above, the inner diameter of the downpipe is greater than 67.0 mm, the wall thickness of the downpipe is greater than 2.2 mm, the siphon inducing component is cylindrical and has a reduced diameter portion, the reduced diameter portion has a flow path cross-sectional area smaller than the flow path cross-sectional area of ​​the connecting portion, and the siphon inducing component is located immediately below the connecting portion in the flow path.

[0011] The siphon inducing member of one embodiment of the present invention constitutes a part of a rainwater pipe trough system, wherein the rainwater pipe trough system comprises: a downpipe; and a connecting portion, which connects the downspout of the eaves with the end on the upstream side of the downpipe, and the cross-sectional area of ​​the flow path of the eaves is 11000mm 2 In the above, the inner diameter of the downpipe is greater than 67.0 mm, the wall thickness of the downpipe is greater than 2.2 mm, the siphon inducing component is cylindrical and can be arranged in the flow path just below the connecting part, and has a reduced diameter part, and the reduced diameter part has a flow path cross-sectional area smaller than the flow path cross-sectional area of ​​the connecting part.

[0012] A siphon inducing member of one embodiment of the present invention constitutes a part of a piping system, and the piping system constitutes a flow path. The siphon inducing member has a first end and a second end facing the upstream side and the downstream side of the piping system, respectively, and is in a cylindrical shape having an inner peripheral surface that defines a cross-sectional area of ​​the flow path. The siphon inducing member includes: a reduced diameter portion whose cross-sectional area of ​​the flow path decreases as it moves from the first end to the second end; and an expanded diameter portion whose cross-sectional area of ​​the flow path increases as it moves from the reduced diameter portion to the second end.

[0013] Effects of the Invention

[0014] The solution of the present invention can improve the drainage capacity while reducing the impact on the appearance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of a configuration example of a rainwater pipe system according to the first embodiment.

[0016] Figure 2 This is a partial appearance diagram of the rainwater pipe trough system of implementation mode 1.

[0017] Figure 3 It is a partial cross-sectional view of the rainwater pipe trough system of embodiment 1.

[0018] Figure 4 It is an explanatory diagram of the siphon inducing member and the second connection joint of the rainwater pipe trough system according to the first embodiment.

[0019] Figure 5 It is a side view of the siphon inducing member of the rainwater pipe trough system of embodiment 1.

[0020] Figure 6 It is a top view of the siphon inducing member of the rainwater pipe trough system of embodiment 1.

[0021] Figure 7 It is a cross-sectional view of the siphon inducing member of the rainwater pipe trough system according to the first embodiment.

[0022] Figure 8 This is a schematic diagram of a configuration example of a rainwater pipe system according to the second embodiment.

[0023] Fig. 9 This is a partial appearance diagram of the rainwater pipe trough system of implementation mode 2.

[0024] Fig.10 This is a partial cross-sectional view of the rainwater pipe trough system of embodiment 2.

[0025] Fig.11 This is an explanatory diagram of a siphon inducing member and a connecting joint of a rainwater pipe trough system according to a second embodiment.

[0026] Fig.12 This is a perspective view of a piping system according to a third embodiment.

[0027] Fig.13 This is a side view of the piping system of Embodiment 3 with part omitted.

[0028] Fig.14 This is a partially omitted cross-sectional view of the piping system according to the third embodiment.

[0029] Fig.15 This is an exploded perspective view of a piping system according to Embodiment 3 with a portion omitted.

[0030] Fig.16 This is an exploded perspective view of a piping member of a piping system according to a third embodiment.

[0031] Fig.17 This is an exploded perspective view of the siphon inducing member of the piping member according to the third embodiment when viewed from above.

[0032] Fig.18 This is an exploded perspective view of the siphon inducing member according to Embodiment 3 when viewed from below.

[0033] Fig.19 This is a top view of the siphon inducing member according to the third embodiment.

[0034] Fig. 20 This is a bottom view of the siphon inducing member of the third embodiment.

[0035] Fig.21 It is a bottom view of the reduced diameter portion of the siphon inducing member according to the third embodiment.

[0036] Fig. 22 It is a top view of the expanded diameter portion of the siphon inducing member according to the third embodiment.

[0037] Fig.23 This is a cross-sectional view of a siphon inducing member according to a third embodiment.

[0038] Fig.24 It is a top view of the joint member of the piping member according to the third embodiment.

[0039] Fig.25 It is a bottom view of the joint member of Embodiment 3.

[0040] Fig.26 It is a cross-sectional view of the joint member according to the third embodiment.

[0041] Fig. 27 This is a side view of a structural example of a siphon inducing member according to Modification 1.

[0042] Fig.28 This is a top view of the siphon inducing member of Modification 1.

[0043] Fig.29 This is a cross-sectional view of a siphon inducing member according to Modification 1.

[0044] Fig.30 It is a side view of a structural example of a siphon inducing member according to Modification Example 2.

[0045] Fig.31 It is a top view of the siphon inducing member of Modification Example 2.

[0046] Fig.32 It is a cross-sectional view of a siphon inducing member according to Modification 2.

[0047] Fig.33 It is a side view of a structural example of a siphon inducing member according to Modification Example 3.

[0048] Fig.34 It is a top view of the siphon inducing member of Modification Example 3.

[0049] Fig.35 It is a cross-sectional view of a siphon inducing member according to Modification 3.

[0050] Fig.36 It is a side view of a structural example of a siphon inducing member according to Modification Example 4.

[0051] Fig.37 It is a top view of the siphon inducing member of Modification Example 4.

[0052] Fig.38 It is a cross-sectional view of a siphon inducing member according to Modification 4.

[0053] Fig.39 It is a side view of a structural example of a siphon inducing member according to Modification Example 5.

[0054] Fig.40 It is a top view of the siphon inducing member of Modification Example 5.

[0055] Fig.41 It is a cross-sectional view of a siphon inducing member according to Modification 5.

[0056] Fig.42It is a side view of a structural example of a siphon inducing member according to Modification Example 6.

[0057] Fig.43 It is a top view of the siphon inducing member of the modification example 6.

[0058] Fig.44 It is a cross-sectional view of a siphon inducing member of Modification Example 6.

[0059] Fig.45 It is an explanatory diagram of a structural example of a siphon inducing member of Modification Example 7 and a second connection joint.

[0060] Fig.46 It is a cross-sectional view of a siphon inducing member of Modification Example 7. DETAILED DESCRIPTION

[0061] The following describes the implementation mode in detail with appropriate reference to the drawings. However, sometimes the necessary detailed description is omitted. For example, a detailed description of known matters, repeated description of substantially the same structure, etc. This is to avoid the following description from becoming unnecessarily lengthy and to make it easy for those skilled in the art to understand. It should be noted that the inventor (s) provides the drawings and the following description in order to enable those skilled in the art to fully understand the present invention, and does not intend to limit the subject matter recorded in the patent technical solution.

[0062] Unless otherwise specified, the positional relationship of up, down, left, and right is based on the positional relationship shown in the drawings. The figures described in the following embodiments are schematic diagrams, and the size and thickness ratios of the components in the figures do not necessarily reflect the actual size ratios. In addition, the size ratios of the components are not limited to the ratios shown in the drawings.

[0063] It should be noted that in the following description, when it is necessary to distinguish multiple components from each other, connectors such as "first" and "second" are attached to the names of the components. However, when the components can be distinguished from each other by using the figure marks attached to the components, connectors such as "first" and "second" are sometimes omitted in consideration of the readability of the article.

[0064] [1. Implementation Method]

[0065] [1.1 Implementation Method 1]

[0066] [1.1.1 Structure]

[0067] Figure 11 is a schematic diagram of a structural example of a rainwater pipe trough system 1 of the present embodiment. The rainwater pipe trough system 1 receives rainwater from a roof 11a of a building 11 and flows it toward a box 21 on the ground 20. The rainwater pipe trough system 1 constitutes a flow path 1a of rainwater. The rainwater collected in the box 21 flows out from the box 21 to the rainwater pipe through a buried pipe 22. The building 11 is a non-residential facility such as a store, office, factory, building, school, welfare facility, or hospital, and a residential facility such as a single-family detached house, a collective house, or each resident of a single-family detached house or a collective house. Non-residential facilities also include theaters, movie theaters, auditoriums, amusement parks, complex facilities, department stores, Western-style hotels, Japanese-style hotels, kindergartens, libraries, museums, art galleries, underground shopping streets, stations, and airports.

[0068] Figure 1 The rainwater pipe trough system 1 includes an eave 2, a downpipe 3, a discharge pipe 4, a siphon inducing component 5, a lateral branch pipe 6, a first connecting joint 7a, a second connecting joint 7b and an auxiliary downpipe 8.

[0069] The eaves gutter 2 receives rainwater from the roof 11a of the building 11. The eaves gutter 2 is provided under the roof 11a of the building 11. As an example, the eaves gutter 2 is arranged at the eaves of the roof 11a. In particular, the eaves gutter 2 is arranged so as to extend along the eaves of the roof 11a. Figure 1 The eaves 2 are in the shape of long barrels. Figure 1 The eaves 2 includes a bottom wall 2a, a first side wall 2b, and a second side wall 2c. The first side wall 2b and the second side wall 2c are also referred to as standing walls.

[0070] The bottom wall 2a is in the shape of a plate having a length, a width and a thickness. For example, the bottom wall 2a is in the shape of a rectangular plate. In the length direction of the bottom wall 2a, the width and thickness of the bottom wall 2a are substantially constant. A water outlet 2d is formed on the bottom wall 2a in accordance with the overall design of the rainwater pipe trough system 1. The water outlet 2d is, for example, a circular opening.

[0071] The first side wall 2b and the second side wall 2c extend upward from both sides of the bottom wall 2a in the width direction. In particular, the second side wall 2c extends upward from the end of the bottom wall 2a on the building 11 side in the width direction, and the first side wall 2b extends upward from the end of the bottom wall 2a on the side opposite to the building 11 in the width direction. The first side wall 2b and the second side wall 2c are plate-shaped with length, width and thickness. The first side wall 2b and the second side wall 2c are rectangular plate-shaped. In the length direction of the first side wall 2b, the width and thickness of the first side wall 2b are approximately constant. In the length direction of the second side wall 2c, the width and thickness of the second side wall 2c are approximately constant.

[0072] As an example, the eave 2 can be formed by extrusion molding of a resin material. The eave 2 can have a core material for reinforcing the strength of the eave 2 as a whole. The core material can be made of metal, for example. As another example, the eave 2 can also be formed of a metal plate, such as a steel plate (also called a steel coil).

[0073] The gutter 2 has a flow path cross-sectional area S. The flow path cross-sectional area S is determined, for example, according to the scale of the building 11. The flow path cross-sectional area S means the cross-sectional area in which rainwater can flow in the gutter 2 when viewed along the length direction of the gutter 2. The flow path cross-sectional area S is the area of ​​the region surrounded by the bottom wall 2a, the first side wall 2b, the second side wall 2c, and the reference line 2e. The reference line 2e is the highest water surface at which rainwater does not overflow from the gutter 2. That is, when the water surface exceeds the reference line 2e, rainwater overflows from the gutter 2. The reference line 2e is a line that passes through the lower of the upper end of the first side wall 2b and the upper end of the second side wall 2c and is along the horizontal plane. Figure 1 In the embodiment, the upper end of the first side wall 2b and the upper end of the second side wall 2c are at the same position, so the reference line 2e passes through the upper end of the first side wall 2b and the upper end of the second side wall 2c. In this embodiment, the flow path cross-sectional area S is 11000mm 2 The flow path cross-sectional area S can be 29000mm 2 The flow path cross-sectional area S can be 40000mm 2 above.

[0074] The discharge pipe 4 is arranged at the water outlet 2d of the eave 2. The discharge pipe 4 reduces the generation of vortex at the water collection port 2b and the entrainment of air. The discharge pipe 4 can help the generation of siphon phenomenon. The discharge pipe 4 can be a known structure.

[0075] The downpipe 3 is provided to discharge rainwater from the downpipe 2d. The downpipe 3 allows rainwater from the downpipe 2d to flow vertically. Figure 1 The eaves of the building 11 are relatively long. In the building 11, when the downpipe 3 is directly connected to the downspout 2d, the distance between the downpipe 3 and the wall 11b of the building 11 becomes larger, and the construction standard of the downpipe 3 is not satisfied. Therefore, in the rainwater pipe trough system 1, the downpipe 3 is not directly connected to the downspout 2d, but is connected to the downspout 2d via the lateral branch pipe 6, the first connection joint 7a, and the second connection joint 7b. In this way, the rainwater pipe trough system 1 has a structure suitable for the building 11 with a long eaves.

[0076] The downpipe 3 has an upstream end 3a and a downstream end 3b. The upstream end 3a is the end of the downpipe 3 connected to the downspout 2d ( Figure 1 The downstream end 3b is the end of the downpipe 3 that is inserted into the tank section 21 ( Figure 1In this embodiment, the downstream end 3b is the open end at the lowest point on the ground plane. Figure 1 In the embodiment, the drain pipe cover 34 is arranged so that rainwater does not flow into the box portion 21 from the gap between the downpipe 3 and the box portion 21 .

[0077] exist Figure 1 In the embodiment, the downpipe 3 is fixed to the wall 11b of the building 11 by fixing fittings 33a, 33b, and 33c. It should be noted that the distance [mm] from the ground 20 to the upper end of the downpipe 3, the distance [mm] from the upper end of the downpipe 3 to the uppermost fixing fitting 33a, and the distance [mm] from the ground 20 to the lowermost fixing fitting 33c are generally 200 mm or more and 300 mm or less. The spacing [mm] between the fixing fittings 33a, 33b, and 33c is generally 800 mm or more and 1200 mm or less, and in certain cases is 1000 mm or less. The distance between the downpipe 3 and the wall 11b is generally 30 mm or more and 100 mm or less.

[0078] In this embodiment, the lateral branch pipe 6, the first connection joint 7a, the second connection joint 7b and the auxiliary downpipe 8 constitute a connection portion 9. The connection portion 9 connects the downspout 2d of the eave 2 and the upstream end 3a of the downpipe 3.

[0079] The lateral branch pipe 6 is a portion for allowing rainwater from the building 11 to flow from the downspout 2d to the downspout 3. The lateral branch pipe 6 is located between the downspout 2d of rainwater from the building 11 and the downspout 3. The lateral branch pipe 6 is a straight pipe. The cross section of the lateral branch pipe 6 perpendicular to the pipe axis is circular. Figure 1 The lateral branch pipe 6 is fixed so that the direction of the pipe axis of the lateral branch pipe 6 is inclined with respect to the up-down direction (vertical direction).

[0080] The lateral branch pipe 6 has an upstream end 6a and a downstream end 6b. The upstream end 6a is the end of the lateral branch pipe 6 connected to the water outlet 2d ( Figure 1 The downstream end 6b is the end of the horizontal branch pipe 6 connected to the downpipe 3 ( Figure 1 ).

[0081] As an example, the material of the lateral branch pipe 6 is rigid polyvinyl chloride. The dimensions, such as the outer shape and thickness of the lateral branch pipe 6 can be set in accordance with the standard of rigid polyvinyl chloride pipe (general) of JIS K 6741 "Rigid polyvinyl chloride pipe".

[0082] The first connection joint 7a connects the upstream end 6a of the lateral branch pipe 6 to the water outlet 2d. The first connection joint 7a does not have to be a member that directly connects the upstream end 6a of the lateral branch pipe 6 to the water outlet 2d, and may be a member that indirectly connects the upstream end 6a of the lateral branch pipe 6 to the water outlet 2d via another member. The material of the first connection joint 7a is, for example, hard polyvinyl chloride.

[0083] The first connection joint 7a has a first and second sockets 71a and 72a for connecting pipes such as the downpipe 3 and the lateral branch pipe 6 to the first connection joint 7a, and a bent portion 73a connecting the first and second sockets 71a and 72a. Figure 1 In the figure, the first socket 71a receives the auxiliary downpipe 8, and the second socket 72a receives the lateral branch pipe 6. The angle between the center axes of the first and second sockets 71a, 72a is, for example, 91.17° as specified by JIS K 6739 "Rigid polyvinyl chloride pipe fittings for drainage". The corners on the inner and outer sides of the first connection joint 7a in the plane including the pipe axis of the first connection joint 7a are not rounded, but are roughly right-angled. The size of the first connection joint 7a can be set, for example, according to the standard of JIS K 6739 "Rigid polyvinyl chloride pipe fittings for drainage". The first connection joint 7a can be a 90° bend elbow specified by JIS K 6739.

[0084] The auxiliary downpipe 8 is a portion for allowing rainwater from the building 11 to flow vertically from the downpipe 2d to the first connection joint 7a. The auxiliary downpipe 8 is located between the downpipe 2d and the first connection joint 7a. The auxiliary downpipe 8 is in the shape of a straight pipe. The cross section of the auxiliary downpipe 8 perpendicular to the pipe axis is in a circular shape. The material of the auxiliary downpipe 8 is rigid polyvinyl chloride. The dimensions, such as the shape and thickness of the auxiliary downpipe 8 can be set according to the standard of rigid polyvinyl chloride pipe (general) of JIS K 6741 "Rigid polyvinyl chloride pipe". Figure 1 The auxiliary downpipe 8 is disposed between the downpipe 2d and the first connection joint 7a so that the direction of the pipe axis of the auxiliary downpipe 8 coincides with the up-and-down direction (vertical direction).

[0085] The auxiliary downpipe 8 has an upstream end 8a and a downstream end 8b. The upstream end 8a is the end of the auxiliary downpipe 8 connected to the downspout 2d ( Figure 1 The downstream end 8b is the end of the auxiliary downpipe 8 connected to the first connection joint 7a ( Figure 1 ).

[0086] The second connection joint 7b connects the downstream end 6b of the lateral branch pipe 6 to the upstream end 3a of the downpipe 3. The second connection joint 7b does not need to be a member that directly connects the downstream end 6b of the lateral branch pipe 6 to the upstream end 3a of the downpipe 3, but may be a member that indirectly connects the downstream end 6b of the lateral branch pipe 6 to the upstream end 3a of the downpipe 3 via another member. The material of the second connection joint 7b is, for example, hard polyvinyl chloride.

[0087] Figure 2 This is a partial appearance diagram of the rainwater pipe trough system 1. Figure 3 is a partial cross-sectional view of the rainwater pipe trough system 1. It should be noted that Figure 2 as well as Figure 3 In order to simplify the illustration, the downpipe 3 and the lateral branch pipe 6 are partially omitted. Figure 4 It is an explanatory diagram of the siphon inducing member 5 and the second connection joint 7b.

[0088] like Figure 2 as well as Figure 3 As shown, the second connection joint 7b has a first and second sockets 71b and 72b for connecting the downpipe 3 and the lateral branch pipe 6 and other pipes to the second connection joint 7b, and a bent portion 73b connecting the first and second sockets 71b and 72b. Figure 4 As shown, the first socket 71b has an opening 711b for receiving the lateral branch pipe 6. The second socket 72b has an opening 721b for receiving the downpipe 3. In the present embodiment, the inner diameter D71 of the opening 711b is equal to the inner diameter D72 of the opening 721b. The angle θ1 between the center axes L71 and L72 of the first and second sockets 71b and 72b is, for example, 91.17° as specified by JIS K 6739 "Rigid polyvinyl chloride pipe joint for drainage". θ1 is not limited thereto and may be greater than 91°. The corners of the inner circumference and the outer circumference of the second connection joint 7b in the plane including the pipe axis of the second connection joint 7b are not rounded but are substantially right-angled. The size of the second connection joint 7b can be set, for example, in accordance with the standard of JIS K 6739 "Rigid polyvinyl chloride pipe joint for drainage". At least one of the second connection joints 7b is a 90° bend elbow as specified by JIS K 6739.

[0089] Figure 1 The siphon inducing member 5 constitutes a part of the rainwater trough system 1, and the rainwater trough system 1 constitutes the flow path 1a of rainwater. The siphon inducing member 5 partially reduces the flow path cross-sectional area of ​​the flow path 1a of the rainwater trough system 1. Thus, the siphon inducing member 5 can play an effect of inducing the siphon phenomenon in the rainwater trough system 1 or stably promoting the effect brought about by the siphon phenomenon in the rainwater trough system 1.

[0090] Below, refer to Figure 5 to Figure 7 The siphon inducing member 5 will be further described. Figure 5 It is a side view of the siphon inducing member 5 . Figure 6 It is a top view of the siphon inducing member 5 . Figure 7 It is a cross-sectional view of the siphon inducing member 5 .

[0091] like Figure 5 to Figure 7 As shown in FIG. 1 , the siphon inducing member 5 is tubular. In particular, the siphon inducing member 5 is cylindrical. The siphon inducing member 5 includes a straight tube portion 51 and a reduced diameter portion 52 .

[0092] The straight pipe portion 51 defines at least a portion of the flow path 1a of the rainwater pipe system 1. Figure 6 as well as Figure 7 As shown, in this embodiment, the inner space of the straight pipe portion 51 surrounded by the inner peripheral surface 510 of the straight pipe portion 51 becomes a part of the flow path 1a of the rainwater pipe system 1. Figure 6 As is apparent from the figure, the cross section of the straight tube portion 51 perpendicular to the central axis C1 is circular. The central axis C1 of the straight tube portion 51 is also the tube axis of the straight tube portion 51. The material of the straight tube portion 51 is hard polyvinyl chloride. The dimensions, such as the outer shape and thickness of the straight tube portion 51 can be set in accordance with the standard of hard polyvinyl chloride tube (general) of JIS K 6741 "Hard polyvinyl chloride tube". The straight tube portion 51 is arranged so that the direction of the central axis C1 of the straight tube portion 51 coincides with the up-down direction (vertical direction).

[0093] The straight pipe portion 51 includes a main body portion 51a, a flange portion 51b, and a connecting portion 51c. The flange portion 51b and the connecting portion 51c are located at both ends of the main body portion 51a in the direction of the central axis C1. The flange portion 51b faces the upstream side of the flow path 1a of the straight pipe portion 51, and the connecting portion 51c faces the downstream side of the flow path 1a of the straight pipe portion 51. The flange portion 51b defines an end 511 on the upstream side of the straight pipe portion 51. In the present embodiment, the end 511 on the upstream side of the straight pipe portion 51 is also the end on the upstream side of the siphon inducing member 5. The connecting portion 51c defines an end 512 on the downstream side of the straight pipe portion 51.

[0094] The reduced diameter portion 52 is combined with the straight pipe portion 51 and is arranged in the flow path 1a. The reduced diameter portion 52 has a flow path cross-sectional area that is smaller than the flow path cross-sectional area of ​​the connecting portion 9. In particular, the reduced diameter portion 52 has a flow path cross-sectional area that is smaller than the flow path cross-sectional area of ​​the second connecting joint 7b. The flow path cross-sectional area of ​​the second connecting joint 7b mentioned here may be the minimum value of the flow path cross-sectional area of ​​the second connecting joint 7b observed from the vertical direction. In this embodiment, as Figure 7As shown, the reduced diameter portion 52 is connected to the connecting portion 51c of the straight pipe portion 51. The reduced diameter portion 52 has an upstream end 52a and a downstream end 52b. In the present embodiment, the upstream end 52a of the reduced diameter portion 52 coincides with the downstream end 512 of the straight pipe portion 51. In the present embodiment, the downstream end 52b of the reduced diameter portion 52 is also the downstream end of the siphon inducing member 5. In the present embodiment, the reduced diameter portion 52 is formed integrally with the straight pipe portion 51, thereby being combined with the straight pipe portion 51. The material of the reduced diameter portion 52 is hard polyvinyl chloride, the same as the straight pipe portion 51.

[0095] In the siphon inducing member 5, the inner diameter D1 of the reduced diameter portion 52 is smaller than the inner diameter D2 of the main body portion 51a. The flange portion 51b has the largest inner diameter D3 in the siphon inducing member 5. The inner diameter of the flange portion 51b is reduced from D3 to D2 at the end portion on the main body portion 51a side. The connecting portion 51c has an inner diameter reduced from D2 to D1 from the main body portion 51a toward the reduced diameter portion 52 so as to connect the main body portion 51a having different inner diameters to the reduced diameter portion 52. The inner peripheral surface 513 of the connecting portion 51c is an inclined surface approaching the central axis C1 from the main body portion 51a toward the reduced diameter portion 52.

[0096] according to Figure 6 as well as Figure 7 , the outer diameter of the siphon inducing member 5 becomes the largest in the flange portion 51b. On the contrary, the outer diameter of the siphon inducing member 5 becomes the smallest in the reduced diameter portion 52. The flange portion 51b defines the maximum value (maximum outer diameter D4) of the outer dimensions of the siphon inducing member 5. The maximum outer diameter D4 is larger than the outer diameter D5 of the main body portion 51a. Figure 3 as well as Figure 4 As shown, the flange portion 51b is used for connection with the second socket 72b of the second connection joint 7b. In this embodiment, the flange portion 51b is larger than the outer dimensions of the main body portion 51a and the connecting portion 51c, but is of a size that can be inserted into the second socket 72b of the second connection joint 7b. Figure 4 In the embodiment, the maximum outer diameter D4 is smaller than the inner diameter D72 of the opening 721b of the second bell mouth 72b of the second connection joint 7b. That is, the siphon inducing member 5 is a cylindrical shape that can be arranged just below the second connection joint 7b in the flow path 1a. In the present embodiment, the flange portion 51b is of a size that does not enter the curved portion 73b from the second bell mouth 72b. The insertion degree of the siphon inducing member 5 into the second connection joint 7b can be adjusted by the size and position of the flange portion 51b.

[0097] As described above, the siphon inducing member 5 has the upstream end 511 and the downstream end 52b of the flow path 1a. In the siphon inducing member 5, the downstream end 52b has a smaller flow path cross-sectional area than the upstream end 511.

[0098] Next, the function of the siphon inducing member 5 will be described. As described above, the siphon inducing member 5 has the reduced diameter portion 52, and partially reduces the flow path cross-sectional area of ​​the flow path 1a of the rainwater pipe trough system 1. Therefore, the flow rate of rainwater flowing into the reduced diameter portion 52 from the upstream side of the flow path 1a tends to be larger than the flow rate of rainwater flowing out from the reduced diameter portion 52 to the downstream side of the flow path 1a. Therefore, rainwater tends to accumulate in the reduced diameter portion 52. When rainwater accumulates in the reduced diameter portion 52, the position on the downstream side of the flow path 1a relative to the reduced diameter portion 52 tends to be full of water. Therefore, it is considered that the rainwater in the reduced diameter portion 52 is led away by the rainwater on the downstream side of the flow path 1a relative to the reduced diameter portion 52, and the siphon phenomenon occurs, and the rainwater in the rainwater pipe trough system 1 flows violently to the downstream side. It should be noted that the full water state is not used in a strict sense, and also includes a state that is filled with water to a degree that can be regarded as the full water state (a state close to the full water state).

[0099] Next, the configuration of the siphon inducing member 5 in the rainwater pipe trough system 1 will be described. Figure 1 In the rainwater gutter system 1, the siphon inducing member 5 is located just below the connection portion 9 in the flow path 1a. In particular, the siphon inducing member 5 is located just below the second connection joint 7b in the flow path 1a. In the design of the rainwater gutter system 1, the second connection joint 7b is often located above the head of a person. Therefore, the siphon inducing member 5 just below the second connection joint 7b is also located above the head of a person. That is, compared with the case where the siphon inducing member 5 is arranged separately from the second connection joint 7b downward, the siphon inducing member 5 can be made less conspicuous in the appearance of the rainwater gutter system 1. As a result, the drainage capacity can be improved while reducing the impact on the appearance. In the present invention, "the siphon inducing member 5 is located just below the connection portion 9 or the second connection joint 7b in the flow path 1a" does not exclude the presence of a component that does not substantially affect the structure of the flow path 1a between the connection portion 9 or the second connection joint 7b and the siphon inducing member 5. The components that do not substantially affect the structure of the flow path 1a include connecting components such as adhesives, sealing components such as gaskets, etc. In other words, the components that do not substantially affect the structure of the flow path 1a do not include piping components that can constitute a part of the flow path 1a. In other words, the siphon inducing component 5 can also be said to be directly connected to the connecting portion 9 or the second connecting joint 7b without interposing other piping components.

[0100] like Figure 4 As shown in FIG. 1 , the maximum outer diameter D4 of the siphon inducing member 5 is smaller than the inner diameter D72 of the opening 721b of the second socket 72b of the second connecting joint 7b. Figure 3 As shown, the flange portion 51b of the siphon inducing member 5 can be inserted into the second connecting joint 7b from the opening 721b of the second socket 72b of the second connecting joint 7b.

[0101] In the present embodiment, the length of the flange portion 51b in the direction of the central axis C1 is set so that at least a portion of the main body portion 51a is located in the second socket 72b. Figure 3 In the embodiment, the flange portion 51b and a part of the main body 51a of the siphon inducing member 5 are located in the second connection joint 7b, but the remaining part of the main body 51a of the siphon inducing member 5 and the reduced diameter portion 52 protrude outward from the second socket 72b of the second connection joint 7b. The outer diameter D5 of the main body 51a is smaller than the maximum outer diameter D4, and therefore is naturally smaller than the inner diameter D72 of the opening 721b of the second socket 72b of the second connection joint 7b. Therefore, a gap is generated between the inner circumference of the second socket 72b and the outer circumference of the main body 51a. This gap can be used for connecting the downpipe 3 to the second connection joint 7b.

[0102] like Figure 3 As shown, the downpipe 3 has an outer diameter D3a, an inner diameter D3b and a wall thickness D3c. As an example, the wall thickness D3c is D3c=(D3a-D3b) / 2. In the present embodiment, the inner diameter D3b of the downpipe 3 is 67.0 mm or more. The wall thickness D3c of the downpipe 3 is 2.2 mm or more. From another point of view, the downpipe 3 may have a nominal diameter of 65 or more in a hard polyvinyl chloride pipe of VU or VP in the standard of hard polyvinyl chloride pipe (general) of JIS K 6741 "Hard polyvinyl chloride pipe".

[0103] according to Figure 3 , the outer diameter D3a of the downpipe 3 is smaller than the inner diameter D72 of the opening 721b of the second socket 72b of the second connection joint 7b. Figure 3 The inner diameter D3b of the downpipe 3 is smaller than the maximum outer diameter D4 of the siphon inducing member 5, but larger than the outer diameter D5 of the main body 51a of the siphon inducing member 5. That is, in the siphon inducing member 5, the main body 51a can be inserted into the downpipe 3, but the flange 51b cannot be inserted into the downpipe 3.

[0104] like Figure 3 As shown, the downpipe 3 can be inserted into the gap between the inner circumference of the second socket 72b and the outer circumference of the main body 51a. That is, the downpipe 3 can be connected to the second connection joint 7b even when the siphon inducing member 5 is connected to the second connection joint 7b. Figure 3In the embodiment, the connection portion 9 is directly coupled to the end 3a on the upstream side of the downpipe 3. In particular, the second connection joint 7b is directly coupled to the end 3a on the upstream side of the downpipe 3. As a result, the portion of the siphon inducing member 5 that protrudes outward from the second socket 72b of the second connection joint 7b (a portion of the main body 51a and the reduced diameter portion 52) is located inside the downpipe 3. In this way, in the present embodiment, the siphon inducing member 5 is blocked by the second connection joint 7b and the downpipe 3. Therefore, the siphon inducing member 5 cannot be directly visually confirmed from the appearance of the rainwater pipe trough system 1. Therefore, even if the siphon inducing member 5 is provided, it does not substantially affect the appearance of the rainwater pipe trough system 1. That is, it is possible to improve the drainage capacity while reducing the impact on the appearance.

[0105] There is a view that when the siphon inducing member 5 is not arranged immediately below the second connection joint 7b, but is arranged downwardly from the second connection joint 7b, the greater the distance between the siphon inducing member 5 and the second connection joint 7b, the more noticeable the improvement in drainage capacity. However, if the siphon inducing member 5 is moved downward from the second connection joint 7b, the siphon inducing member 5 is easily noticeable, which is not preferred in terms of the appearance of the rainwater pipe trough system 1. Even in the case where the siphon inducing member 5 is located immediately below the second connection joint 7b, it can be confirmed through experiments that the drainage capacity is expected to be improved by about 2 times compared to the case where the siphon inducing member 5 does not exist. For example, in the case where the building 11 is a relatively small-scale building, it is believed that it can be adequately dealt with by increasing the drainage capacity by about 2 times. As the conditions of a relatively small-scale building referred to in the present invention, a building with a roof area of ​​200m 2 Above and 700m 2 The length of the downpipe 3 is at least one of 2m or more and 3m or less. When considering the drainage capacity required for such a relatively small-scale building, the flow path cross-sectional area S of the eaves 2 is 11000mm 2 As mentioned above, the inner diameter D3b of the downpipe 3 is greater than 67.0 mm, and the wall thickness D3c of the downpipe 3 is preferably greater than 2.2 mm. Here, the wall thickness D3c of the downpipe 3 may be less than 7.6 mm. In such a relatively small-scale building, when the siphon inducing component 5 is located just below the second connection joint 7b, the siphon inducing component 5 is located at a height of about 2m to 3m from the ground. Therefore, it is difficult to attract attention. In this way, the rainwater trough system 1 of this embodiment does not hinder the appearance in a small-scale object, and can obtain drainage capacity while alleviating construction restrictions. That is, according to the rainwater trough system 1, both the appearance improvement and the drainage capacity improvement can be obtained.

[0106] In the present embodiment, the siphon inducing member 5 is hidden by the connecting portion 9 and the downpipe 3. In particular, the siphon inducing member 5 is hidden by the second connecting joint 7b and the downpipe 3. That is, the siphon inducing member 5 cannot be visually confirmed from the outside. During the construction of the rainwater pipe trough system 1, it is convenient to confirm whether the siphon inducing member 5 exists. Therefore, it is preferred that the connecting portion 9 has a mark on the outer surface of the connecting portion 9 for indicating the existence of the siphon inducing member 5. In the present embodiment, as shown in FIG. Figure 2 As shown, the second connection joint 7b has a mark 74 for indicating the presence of the siphon inducing member 5. The mark 74 may be a text, a figure, a symbol, a three-dimensional shape or a color that can be recognized by human sense, or a combination of these. The mark 74 is located on the outer surface of the second connection joint 7b. That is, the mark 74 can be confirmed from the outside. Therefore, the presence or absence of the siphon inducing member 5 can be determined based on the presence or absence of the mark 74. For example, when an overflow occurs after the construction of the rainwater pipe trough system 1 (a state in which rainwater overflows from the eaves 2), it can be easily confirmed whether there is a construction error such as forgetting to install the siphon inducing member 5. The mark 74 can be visually confirmed under visible light. Thus, the presence or absence of the siphon inducing member 5 can be more easily determined. The mark 74 may not be visually confirmed under visible light, but can be visually confirmed only under special circumstances. The special environment can be, for example, under ultraviolet light. That is, the mark 74 may be visually confirmed by irradiating ultraviolet light to the second connection joint 7b using invisible light or the like. Such a mark 74 can be formed with invisible ink or the like.

[0107] Next, various dimensions in the rainwater pipe trough system 1 are further described.

[0108] [Ratio of the inner diameter of the reduced diameter portion to the inner diameter of the downpipe]

[0109] In the present embodiment, the inner diameter D3b of the downpipe 3 is larger than the outer diameter D5 of the main body 51a of the siphon inducing member 5. The inner diameter D1 of the reduced diameter portion 52 is smaller than the outer diameter D5 of the main body 51a of the siphon inducing member 5. Therefore, D1<D3b is satisfied between the inner diameter D3b of the downpipe 3 and the inner diameter D1 of the reduced diameter portion 52. Here, the ratio of the inner diameter of the reduced diameter portion 52 to the inner diameter D3b of the downpipe 3 is set to R1 (=D1 / D3b). The drainage capacity (drainage property, drainage performance) of the rainwater gutter system 1 when R1 was changed was evaluated through drainage experiments, and the results shown in Table 1 below were obtained. In Table 1 below, the drainage capacity was evaluated in three levels of "0", "△", and "×". "0" means that no overflow occurs. "△" means that overflow sometimes occurs. "×" means that overflow occurs with a high probability.

[0110] [Table 1]

[0111]

[0112] According to Table 1, R1 is preferably greater than 0.50 and less than 0.70. Thus, the drainage capacity of the rainwater pipe trough system 1 can be further improved. In addition, R1 can be greater than 0.50 and less than 0.67. Thus, the drainage capacity of the rainwater pipe trough system 1 can be further improved. In addition, R1 can be greater than 0.55 and less than 0.70. Thus, the drainage capacity of the rainwater pipe trough system 1 can be further improved. In addition, R1 can be greater than 0.55 and less than 0.67. Thus, the drainage capacity of the rainwater pipe trough system 1 can be further improved.

[0113] [Ratio of the length of the straight tube portion of the siphon inducing member to the inner diameter of the reduced diameter portion]

[0114] In the present embodiment, the siphon inducing member 5 has a straight tube portion 51 in addition to the reduced diameter portion 52 . Figure 7 The length L1 of the straight pipe portion 51 shown corresponds to the length from the upstream end 511 of the siphon inducing member 5 to the upstream end 52a of the reduced diameter portion 52. When the length L1 changes, the vertical position of the reduced diameter portion 52 relative to the second connection joint 7b also changes. That is, when the length L1 changes, the distance from an arbitrary reference point of the second connection joint 7b to the reduced diameter portion 52 changes. Therefore, the drainage capacity of the rainwater pipe trough system 1 when the ratio R2 (= L1 / D1) of the length L1 of the straight pipe portion 51 of the siphon inducing member 5 to the inner diameter D1 of the reduced diameter portion 52 is changed is evaluated through a drainage experiment. As a result, when R2 is less than 1, the occurrence of overflow is found, but when R2 is 1 or more, the occurrence of overflow cannot be confirmed. Therefore, it is preferable that R2 is 1 or more. In other words, in the siphon inducing member 5, the length L1 from the upstream end 511 of the siphon inducing member 5 to the upstream end 52a of the reduced diameter portion 52 is preferably at least 1 times the inner diameter D1 of the reduced diameter portion 52. This can further improve the drainage capacity of the rainwater gutter system 1.

[0115] [Distance from the downstream end of the reduced diameter portion to the downstream end of the downpipe]

[0116] In this embodiment, the siphon inducing member 5 and the downpipe 3 are connected to the second connection joint 7b. Therefore, the position of the downstream end 52b of the reduced diameter portion 52 and the position of the downstream end 3b of the downpipe 3 can be set independently. Therefore, regarding the positional relationship between the downstream end 52b of the reduced diameter portion 52 and the downstream end 3b of the downpipe 3, the drainage performance of the rainwater pipe trough system 1 was evaluated through a drainage test. Specifically, the drainage test was used to evaluate the drainage performance of the rainwater pipe trough system 1. Figure 1The drainage capacity of the rainwater pipe trough system 1 was evaluated when the distance L2 [m] from the downstream end 52b of the reduced diameter portion 52 to the downstream end 3b of the downpipe 3 was changed, and the results of Table 2 below were obtained. In Table 2 below, the drainage capacity was evaluated in three levels: "0", "△", and "×". "0" means that overflow does not occur. "△" means that overflow sometimes occurs. "×" means that overflow occurs with a high probability.

[0117] [Table 2]

[0118]

[0119] According to Table 2, L2 is preferably greater than 1.0 m. Thus, the drainage capacity of the rainwater pipe trough system 1 can be further improved. In addition, L2 can be greater than 1.1 m. Thus, the drainage capacity of the rainwater pipe trough system 1 can be further improved. In addition, L2 can be greater than 1.2 m. Thus, the drainage capacity of the rainwater pipe trough system 1 can be further improved.

[0120] [1.1.2 Effects, etc.]

[0121] The rainwater pipe trough system 1 described above is a rainwater pipe trough system that constitutes a flow path 1a of rainwater, and includes a downpipe 3, a connection portion 9 that connects the downspout 2d of the eaves 2 to the upstream end 3a of the downpipe 3, and a siphon inducing member 5. The flow path cross-sectional area of ​​the eaves 2 is 11000mm 2 The inner diameter of the downpipe 3 is 67.0 mm or more. The wall thickness of the downpipe 3 is 2.2 mm or more. The siphon inducing member 5 is cylindrical and has a reduced diameter portion 52, and the reduced diameter portion 52 has a flow path cross-sectional area smaller than the flow path cross-sectional area of ​​the connecting portion 9. The siphon inducing member 5 is located immediately below the connecting portion 9 in the flow path 1a. This structure can improve the drainage capacity while reducing the impact on the appearance.

[0122] In the rainwater gutter system 1, the connection portion 9 is directly connected to the upstream end 3a of the downpipe 3. The siphon inducing member 5 is hidden by the connection portion 9 and the downpipe 3. This structure can further reduce the impact on the appearance.

[0123] In the rainwater gutter system 1, the connection part 9 has a mark 74 indicating the presence of the siphon inducing member 5 on the outer surface of the connection part 9. This structure enables the presence of the siphon inducing member 5 to be determined by the presence or absence of the mark 74.

[0124] In the rainwater pipe trough system 1, the connection part 9 includes a lateral branch pipe 6 located between the eave 2 and the downpipe 3, a first connection joint 7a connecting the upstream end 6a of the lateral branch pipe 6 to the downpipe 2d, and a second connection joint 7b connecting the downstream end 6b of the lateral branch pipe 6 to the upstream end 3a of the downpipe 3. The flow path cross-sectional area of ​​the reduced diameter portion 52 is smaller than the flow path cross-sectional area of ​​the second connection joint 7b. The siphon inducing member 5 is located immediately below the second connection joint 7b in the flow path 1a. This structure can improve the drainage capacity while reducing the impact on the appearance.

[0125] The rainwater pipe trough system 1 described above is a rainwater pipe trough system constituting a flow path 1a of rainwater, and is provided with a downpipe 3 connected to a downspout 2d of an eave 2, a lateral branch pipe 6 located between the eave 2 and the downpipe 3, a first connection joint 7a connecting an upstream end 6a of the lateral branch pipe 6 to the downspout 2d, a second connection joint 7b connecting a downstream end 6b of the lateral branch pipe 6 to an upstream end 3a of the downpipe 3, and a siphon inducing member 5. The flow path cross-sectional area S of the eave 2 is 11000 mm 2 The inner diameter D3b of the downpipe 3 is 67.0 mm or more. The wall thickness D3c of the downpipe 3 is 2.2 mm or more. The siphon inducing member 5 is cylindrical and has a reduced diameter portion 52, and the reduced diameter portion 52 has a flow path cross-sectional area smaller than the flow path cross-sectional area of ​​the second connection joint 7b. The siphon inducing member 5 is located immediately below the second connection joint 7b in the flow path 1a. This structure can improve the drainage capacity while reducing the impact on the appearance.

[0126] In the rainwater gutter system 1, the second connection joint 7b is directly connected to the upstream end 3a of the downpipe 3. The siphon inducing member 5 is hidden by the second connection joint 7b and the downpipe 3. This structure can further reduce the impact on the appearance.

[0127] In the rainwater gutter system 1, the second connection joint 7b has a mark 74 on the outer surface of the second connection joint 7b for indicating the presence of the siphon inducing member 5. This structure can determine the presence of the siphon inducing member 5 by the presence or absence of the mark 74.

[0128] In the rainwater pipe trough system 1, the mark 74 can be visually confirmed under visible light. This structure can more easily determine the presence or absence of the mark 74, and thus can more easily determine the presence or absence of the siphon inducing member 5.

[0129] In the rainwater gutter system 1 , the ratio R1 of the inner diameter D1 of the reduced diameter portion 52 to the inner diameter D3b of the downpipe 3 may be greater than 0.50 and less than 0.70. This structure can further improve the drainage capacity of the rainwater gutter system 1 .

[0130] In the rainwater gutter system 1, in the siphon inducing member 5, the length L1 from the upstream end 511 of the siphon inducing member 5 to the upstream end 52a of the reduced diameter portion 52 is at least 1 times the inner diameter D1 of the reduced diameter portion 52. This structure can further improve the drainage capacity of the rainwater gutter system 1.

[0131] In the rainwater gutter system 1, the distance L2 from the downstream end 52b of the reduced diameter portion 52 to the downstream end 3b of the downpipe 3 is 1.0 m or more. This structure can further improve the drainage capacity of the rainwater gutter system 1.

[0132] The siphon inducing member 5 described above is a siphon inducing member constituting a part of the rainwater pipe trough system 1, and the rainwater pipe trough system 1 constitutes a flow path 1a of rainwater. The rainwater pipe trough system 1 includes a downpipe 3 and a connecting portion 9 connecting the downspout 2d of the eave 2 and the upstream end 3a of the downpipe 3. The flow path cross-sectional area of ​​the eave 2 is 11000mm 2 The inner diameter of the downpipe 3 is 67.0 mm or more. The wall thickness of the downpipe 3 is 2.2 mm or more. The siphon inducing member 5 is a cylindrical shape that can be arranged just below the connecting portion 9 in the flow path 1a, and has a reduced diameter portion 52, and the reduced diameter portion 52 has a flow path cross-sectional area that is smaller than the flow path cross-sectional area of ​​the connecting portion 9. This structure can improve the drainage capacity while reducing the impact on the appearance.

[0133] The siphon inducing component 5 described above is a siphon inducing component that constitutes a part of the rainwater pipe trough system 1, and the rainwater pipe trough system 1 constitutes the flow path 1a of rainwater. The rainwater pipe trough system 1 has a downpipe 3 connected to the downspout 2d of the eaves 2, a horizontal branch pipe 6 located between the eaves 2 and the downpipe 3, a first connection joint 7a that connects the upstream end 6a of the horizontal branch pipe 6 to the downspout 2d, and a second connection joint 7b that connects the downstream end 6b of the horizontal branch pipe 6 to the upstream end 3a of the downpipe 3. The flow path cross-sectional area of ​​the eaves 2 is 11000mm 2 The inner diameter of the downpipe 3 is 67.0 mm or more. The wall thickness of the downpipe 3 is 2.2 mm or more. The siphon inducing member 5 is a cylindrical shape that can be arranged immediately below the second connection joint 7b in the flow path 1a, and has a reduced diameter portion 52, and the reduced diameter portion 52 has a flow path cross-sectional area that is smaller than the flow path cross-sectional area of ​​the second connection joint 7b. This structure can improve the drainage capacity while reducing the impact on the appearance.

[0134] [1.2 Implementation Method 2]

[0135] [1.2.1 Structure]

[0136] Figure 81 is a schematic diagram of a configuration example of a rainwater pipe system 10 according to the present embodiment. The rainwater pipe system 10 receives rainwater from a roof 11a of a building 11 and flows the rainwater to a tank 21 on the ground 20. The rainwater pipe system 10 forms a flow path 1a for rainwater.

[0137] Figure 8 The rainwater pipe trough system 10 includes an eave 2, a downpipe 3, a discharge pipe 4, a siphon inducing component 5, an auxiliary downpipe 60 and a connecting joint 7.

[0138] The downpipe 3 is provided to discharge rainwater from the downpipe 2d. The downpipe 3 allows rainwater from the downpipe 2d to flow vertically. The downpipe 3 has an upstream end 3a and a downstream end 3b. The upstream end 3a is the end of the downpipe 3 connected to the downpipe 2d ( Figure 8 ). Figure 8 In the embodiment, the downpipe 3 is connected to the downspout 2d in the vertical direction. That is, rainwater falls vertically from the downspout 2d into the downpipe 3 and flows into the box bucket 21. The downstream end 3b is the end of the downpipe 3 inserted into the box bucket 21 ( Figure 8 In this embodiment, the downstream end 3b is the open end at the lowest end of the ground plane.

[0139] In the present embodiment, the auxiliary downpipe 60 and the connection joint 70 constitute a connection portion 90. The connection portion 90 connects the downpipe 2d of the eave 2 and the upstream end 3a of the downpipe 3.

[0140] The auxiliary downpipe 60 is a portion for allowing rainwater from the building 11 to flow vertically from the downpipe 2d to the downpipe 3. The auxiliary downpipe 60 is located between the downpipe 2d and the downpipe 3. The auxiliary downpipe 60 is in a straight pipe shape. The cross section of the auxiliary downpipe 60 perpendicular to the pipe axis is in a circular shape. The material of the auxiliary downpipe 60 is hard polyvinyl chloride. The dimensions, such as the shape and thickness of the auxiliary downpipe 60 can be set according to the standard of hard polyvinyl chloride pipe (general) of JIS K 6741 "Hard polyvinyl chloride pipe". Figure 8 The auxiliary downpipe 60 is disposed between the downpipe 3 and the drain port 2 d so that the direction of the pipe axis of the auxiliary downpipe 60 coincides with the up-down direction (vertical direction).

[0141] The auxiliary downpipe 60 has an upstream end 60a and a downstream end 60b. The upstream end 60a is the end of the auxiliary downpipe 60 connected to the downspout 2d ( Figure 8 The downstream end 60b is the end of the auxiliary downpipe 60 connected to the downpipe 3 ( Figure 8 ).

[0142] The connection joint 7 linearly connects the pipe members such as the downpipe 3 , the drain pipe 4 , and the auxiliary downpipe 60 . Figure 1 The connection joint 7 connects the downstream end 60b of the auxiliary downpipe 60 to the upstream end 3a of the downpipe 3 along the vertical direction. The connection joint 7 does not have to be a member that directly connects the downstream end 60b of the auxiliary downpipe 60 to the upstream end 3a of the downpipe 3, and may be a member that indirectly connects the downstream end 60b of the auxiliary downpipe 60 to the upstream end 3a of the downpipe 3 via other members. The material of the connection joint 7 is, for example, hard polyvinyl chloride.

[0143] Fig. 9 is a partial appearance diagram of the rainwater pipe trough system 10, Fig.10 is a partial cross-sectional view of the rainwater pipe trough system 10. It should be noted that Fig. 9 as well as Fig.10 In order to simplify the illustration, the downpipe 3 and the auxiliary downpipe 60 are partially omitted. Fig.11 It is an explanatory diagram of the siphon inducing member 5 and the connecting joint 7 .

[0144] like Fig. 9 as well as Fig.10 As shown, the connection joint 7 has a first socket 71 and a second socket 72 in the direction of the central axis C2 and an intermediate portion 73 between the first socket 71 and the second socket 72. The first socket 71 and the second socket 72 are used to connect the pipe components such as the downpipe 3, the discharge pipe 4 and the auxiliary downpipe 60 to the connection joint 7. Fig.11 As shown, the first socket 71 has an opening 711 for receiving the auxiliary downpipe 60. The second socket 72 has an opening 721 for receiving the downpipe 3. The inner diameter of the first socket 71 becomes maximum at the opening 711 and becomes minimum at the boundary portion with the middle portion 73. The inner diameter of the second socket 72 becomes maximum at the opening 722 and becomes minimum at the boundary portion with the middle portion 73. In this embodiment, the minimum inner diameter D71a of the first socket 71 is equal to the minimum inner diameter D72a of the second socket 72. The inner diameter D73a of the middle portion 73 is smaller than the minimum inner diameters D71a and D72a. The outer diameters of the first socket 71, the second socket 72 and the middle portion 73 are equal. The connecting joint 7 can be a socket specified by JIS K 6739.

[0145] Figure 8 The siphon inducing member 5 constitutes a part of the rainwater trough system 10, and the rainwater trough system 10 constitutes the flow path 1a of rainwater. The siphon inducing member 5 partially reduces the flow path cross-sectional area of ​​the flow path 1a of the rainwater trough system 10. Thus, the siphon inducing member 5 can play an effect of inducing the siphon phenomenon in the rainwater trough system 10 or stably promoting the effect brought about by the siphon phenomenon in the rainwater trough system 10.

[0146] The siphon inducing member 5 of this embodiment has the same structure as the siphon inducing member 5 of Embodiment 1, but the connecting portion 90 of this embodiment is different from the connecting portion 9 of Embodiment 1. In order to avoid redundant description, the relationship between the connecting portion 90 and the siphon inducing member 5 will be described below.

[0147] The reduced diameter portion 52 has a flow path cross-sectional area smaller than that of the connection portion 90. In particular, the reduced diameter portion 52 has a flow path cross-sectional area smaller than that of the connection joint 7. The flow path cross-sectional area of ​​the connection joint 7 referred to here may be the minimum value of the flow path cross-sectional area of ​​the connection joint 7 as viewed in the vertical direction.

[0148] like Fig.10 as well as Fig.11 As shown, the flange portion 51b is used for connection with the second socket 72 of the connection joint 7. In this embodiment, the flange portion 51b is larger than the outer dimensions of the main body portion 51a and the connecting portion 51c, but is of a size that can be inserted into the second socket 72 of the connection joint 7. Fig.11 In the embodiment, the maximum outer diameter D4 is smaller than the minimum inner diameter D72a of the second bell mouth 72 of the connection joint 7. That is, the siphon inducing member 5 is a cylindrical shape that can be arranged just below the connection joint 7 in the flow path 1a. In the present embodiment, the flange portion 51b is of a size that does not enter the middle portion 73 from the second bell mouth 72. That is, the maximum outer diameter D4 is larger than the inner diameter D73a of the middle portion 73. The insertion degree of the siphon inducing member 5 into the connection joint 7 can be adjusted according to the size and position of the flange portion 51b.

[0149] Next, the configuration of the siphon inducing member 5 in the rainwater pipe trough system 10 will be described. Figure 8 In the rainwater gutter system 10, the siphon inducing member 5 is located just below the connection portion 90 in the flow path 1a. In particular, the siphon inducing member 5 is located just below the connection joint 7 in the flow path 1a. In the design of the rainwater gutter system 10, the connection joint 7 is often located above the head of a person. Therefore, the siphon inducing member 5 just below the connection joint 7 is also located above the head of a person. That is, compared with the case where the siphon inducing member 5 is arranged separately from the connection joint 7 downward, the siphon inducing member 5 can be made less conspicuous in the appearance of the rainwater gutter system 10. As a result, the drainage capacity can be improved while reducing the impact on the appearance. In the present invention, "the siphon inducing member 5 is located just below the connection portion 90 or the connection joint 7 in the flow path 1a" does not exclude the presence of a component that does not substantially affect the structure of the flow path 1a between the connection portion 90 or the connection joint 7 and the siphon inducing member 5. In other words, it can be said that the siphon inducing member 5 is directly connected to the connection portion 90 or the connection joint 7 without interposing any other piping member.

[0150] like Fig.11 As shown in FIG. 1 , the maximum outer diameter D4 of the siphon inducing member 5 is smaller than the minimum inner diameter D72a of the second socket 72 of the connecting joint 7. Fig.10 As shown, the flange portion 51 b of the siphon inducing member 5 can be inserted into the connecting joint 7 from the opening 721 of the second socket 72 of the connecting joint 7 .

[0151] In the present embodiment, the length of the flange portion 51b in the direction of the central axis C1 is set so that at least a portion of the main body portion 51a is located in the second socket 72. Fig.10 In the embodiment, the flange portion 51b and a part of the main body 51a of the siphon inducing member 5 are located in the connection joint 7, but the remaining part of the main body 51a of the siphon inducing member 5 and the reduced diameter portion 52 protrude outward from the second bell mouth 72 of the connection joint 7. The outer diameter D5 of the main body 51a is smaller than the maximum outer diameter D4, and therefore is naturally smaller than the minimum inner diameter D72a of the second bell mouth 72 of the connection joint 7. Therefore, a gap is generated between the inner peripheral surface of the second bell mouth 72 and the outer peripheral surface of the main body 51a. This gap can be used for connecting the downpipe 3 to the connection joint 7.

[0152] according to Fig.10 , the outer diameter D3a of the downpipe 3 is smaller than the minimum inner diameter D72a of the second socket 72 of the connecting joint 7. Fig.10 The inner diameter D3b of the downpipe 3 is smaller than the maximum outer diameter D4 of the siphon inducing member 5, but larger than the outer diameter D5 of the main body 51a of the siphon inducing member 5. That is, in the siphon inducing member 5, the main body 51a can be inserted into the downpipe 3, but the flange 51b cannot be inserted into the downpipe 3.

[0153] like Fig.10 As shown, the downpipe 3 can be inserted into the gap between the inner circumference of the second socket 72 and the outer circumference of the main body 51a. That is, the downpipe 3 can be connected to the connection joint 7 even when the siphon inducing member 5 is connected to the connection joint 7. Fig.10 In the embodiment, the connection portion 90 is directly coupled to the end 3a on the upstream side of the downpipe 3. In particular, the connection joint 7 is directly coupled to the end 3a on the upstream side of the downpipe 3. As a result, the portion of the siphon inducing member 5 that protrudes outward from the second socket 72 of the connection joint 7 (a portion of the main body 51a and the reduced diameter portion 52) is located inside the downpipe 3. In this way, in the present embodiment, the siphon inducing member 5 is blocked by the connection joint 7 and the downpipe 3. Therefore, the siphon inducing member 5 cannot be directly visually confirmed from the appearance of the rainwater pipe trough system 10. Therefore, even if the siphon inducing member 5 is provided, it does not substantially affect the appearance of the rainwater pipe trough system 10. That is, it is possible to improve the drainage capacity while reducing the impact on the appearance.

[0154] There is a view that when the siphon inducing member 5 is not arranged immediately below the connection joint 7 but is arranged downwardly from the connection joint 7, the greater the distance between the siphon inducing member 5 and the connection joint 7, the more noticeable the improvement in drainage capacity. However, if the siphon inducing member 5 is moved downward from the connection joint 7, the siphon inducing member 5 is easily noticeable, which is not preferred in terms of the appearance of the rainwater pipe trough system 10. Even in the case where the siphon inducing member 5 is located immediately below the connection joint 7, it can be confirmed through experiments that the drainage capacity is expected to be improved by about 2 times compared to the case where the siphon inducing member 5 does not exist. For example, in the case where the building 11 is a relatively small-scale building, it is believed that the drainage capacity can be adequately dealt with by increasing the drainage capacity by about 2 times. In such a relatively small-scale building, when the siphon inducing member 5 is located immediately below the connection joint 7, the siphon inducing member 5 is located at a height of about 2m to 3m above the ground. Therefore, it is difficult to be noticeable. Thus, the rainwater gutter system 10 of this embodiment can obtain drainage capacity while alleviating construction restrictions without affecting the appearance in a small-scale object. That is, according to the rainwater gutter system 10, both the appearance and drainage capacity can be improved.

[0155] In the present embodiment, the siphon inducing member 5 is hidden by the connection portion 90 and the downpipe 3. In particular, the siphon inducing member 5 is hidden by the connection joint 7 and the downpipe 3. That is, the siphon inducing member 5 cannot be visually confirmed from the outside. During the construction of the rainwater pipe trough system 1, it is convenient to confirm whether the siphon inducing member 5 exists. Therefore, it is preferred that the connection portion 90 has a mark on the outer surface of the connection portion 90 for indicating the existence of the siphon inducing member 5. In the present embodiment, as shown in FIG. Fig. 9 As shown, the connection connector 7 has a marking 74 for indicating the presence of the siphon inducing member 5 .

[0156] Next, various dimensions in the rainwater pipe trough system 10 are further described.

[0157] [Ratio of the inner diameter of the reduced diameter portion to the inner diameter of the downpipe]

[0158] In the present embodiment, the inner diameter D3b of the downpipe 3 is larger than the outer diameter D5 of the main body 51a of the siphon inducing member 5. The inner diameter D1 of the reduced diameter portion 52 is smaller than the outer diameter D5 of the main body 51a of the siphon inducing member 5. Therefore, D1<D3b is satisfied between the inner diameter D3b of the downpipe 3 and the inner diameter D1 of the reduced diameter portion 52. Here, the ratio of the inner diameter of the reduced diameter portion 52 to the inner diameter D3b of the downpipe 3 is set to R1 (=D1 / D3b). The drainage capacity (drainage property, drainage performance) of the rainwater gutter system 10 when R1 was changed was evaluated through a drainage experiment, and the same results as those in Table 1 above were obtained.

[0159] According to Table 1, R1 is preferably greater than 0.50 and less than 0.70. Thus, the drainage capacity of the rainwater pipe trough system 10 can be further improved. In addition, R1 can be greater than 0.50 and less than 0.67. Thus, the drainage capacity of the rainwater pipe trough system 10 can be further improved. In addition, R1 can be greater than 0.55 and less than 0.70. Thus, the drainage capacity of the rainwater pipe trough system 10 can be further improved. In addition, R1 can be greater than 0.55 and less than 0.67. Thus, the drainage capacity of the rainwater pipe trough system 10 can be further improved.

[0160] [Ratio of the length of the straight tube portion of the siphon inducing member to the inner diameter of the reduced diameter portion]

[0161] In the present embodiment, when the length L1 of the straight pipe portion 51 changes, the position of the reduced diameter portion 52 in the vertical direction relative to the connection joint 7 also changes. That is, when the length L1 changes, the distance from an arbitrary reference point of the connection joint 7 to the reduced diameter portion 52 changes. Therefore, the drainage capacity of the rainwater pipe trough system 10 when the ratio R2 (=L1 / D1) of the length L1 of the straight pipe portion 51 of the siphon inducing member 5 to the inner diameter D1 of the reduced diameter portion 52 is changed was evaluated through a drainage experiment. As a result, when R2 is less than 1, the occurrence of overflow is found, but when R2 is 1 or more, the occurrence of overflow is not confirmed. Therefore, it is preferable that R2 is 1 or more. In other words, in the siphon inducing member 5, it is preferable that the length L1 from the upstream end 511 of the siphon inducing member 5 to the upstream end 52a of the reduced diameter portion 52 is 1 times or more of the inner diameter D1 of the reduced diameter portion 52. As a result, the drainage capacity of the rainwater pipe trough system 10 can be further improved.

[0162] [Distance from the downstream end of the reduced diameter portion to the downstream end of the downpipe]

[0163] In this embodiment, the siphon inducing member 5 and the downpipe 3 are connected to the connection joint 7. Therefore, the position of the downstream end 52b of the reduced diameter portion 52 and the position of the downstream end 3b of the downpipe 3 can be set independently. Therefore, the drainage performance of the rainwater pipe trough system 10 was evaluated through a drainage test with respect to the positional relationship between the downstream end 52b of the reduced diameter portion 52 and the downstream end 3b of the downpipe 3. Specifically, the drainage test was performed to evaluate the drainage performance of the rainwater pipe trough system 10. Figure 8 The drainage capacity of the rainwater gutter system 10 was evaluated when the distance L2 [m] from the downstream end 52b of the reduced diameter portion 52 to the downstream end 3b of the downpipe 3 was changed as shown, and the same results as those in Table 2 above were obtained.

[0164] According to Table 2, L2 is preferably greater than 1.0 m. Thus, the drainage capacity of the rainwater pipe trough system 10 can be further improved. In addition, L2 can be greater than 1.1 m. Thus, the drainage capacity of the rainwater pipe trough system 10 can be further improved. In addition, L2 can be greater than 1.2 m. Thus, the drainage capacity of the rainwater pipe trough system 10 can be further improved.

[0165] [1.2.2 Effects, etc.]

[0166] The rainwater pipe trough system 10 described above is a rainwater pipe trough system that constitutes a flow path 1a of rainwater, and includes a downpipe 3, a connection portion 90 that connects the downspout 2d of the eaves 2 to the upstream end 3a of the downpipe 3, and a siphon inducing member 5. The flow path cross-sectional area of ​​the eaves 2 is 11000mm 2 The inner diameter of the downpipe 3 is 67.0 mm or more. The wall thickness of the downpipe 3 is 2.2 mm or more. The siphon inducing member 5 is cylindrical and has a reduced diameter portion 52 having a flow path cross-sectional area smaller than the flow path cross-sectional area of ​​the connecting portion 90. The siphon inducing member 5 is located immediately below the connecting portion 90 in the flow path 1a. This structure can improve the drainage capacity while reducing the impact on the appearance.

[0167] In the rain gutter system 10, the connection portion 90 is directly connected to the upstream end 3a of the downpipe 3. The siphon inducing member 5 is hidden by the connection portion 90 and the downpipe 3. This structure can further reduce the impact on the appearance.

[0168] In the rainwater gutter system 10, the connection part 90 has a mark 74 indicating the presence of the siphon inducing member 5 on the outer surface of the connection part 90. This structure enables the presence of the siphon inducing member 5 to be determined by the presence or absence of the mark 74.

[0169] In the rainwater gutter system 10, the connection portion 90 includes a connection joint 7 that connects the upstream end 3a of the downpipe 3 to the downspout 2d in the vertical direction. The flow path cross-sectional area of ​​the reduced diameter portion 52 is smaller than the flow path cross-sectional area of ​​the connection joint 7. The siphon inducing member 5 is located immediately below the connection joint 7 in the flow path 1a. This structure can improve the drainage capacity while reducing the impact on the appearance.

[0170] The rainwater pipe trough system 10 described above is a rainwater pipe trough system that constitutes a flow path 1a of rainwater, and includes a downpipe 3 connected to the downspout 2d of the eaves 2, a connection joint 7 that connects the upstream end 3a of the downpipe 3 to the downspout 2d, and a siphon inducing member 5. The flow path cross-sectional area S of the eaves 2 is 11000mm 2The inner diameter D3b of the downpipe 3 is 67.0 mm or more. The wall thickness D3c of the downpipe 3 is 2.2 mm or more. The siphon inducing member 5 is cylindrical and has a reduced diameter portion 52, and the reduced diameter portion 52 has a flow path cross-sectional area smaller than the flow path cross-sectional area of ​​the connecting joint 7. The siphon inducing member 5 is located immediately below the connecting joint 7 in the flow path 1a. This structure can improve the drainage capacity while reducing the impact on the appearance.

[0171] In the rainwater gutter system 10, the connection joint 7 is directly connected to the upstream end 3a of the downpipe 3. The siphon inducing member 5 is hidden by the connection joint 7 and the downpipe 3. This structure can further reduce the impact on the appearance.

[0172] In the rainwater gutter system 10, the connection joint 7 has a mark 74 indicating the presence of the siphon inducing member 5 on the outer surface of the connection joint 7. This structure enables the presence of the siphon inducing member 5 to be determined by the presence or absence of the mark 74.

[0173] In the rainwater pipe trough system 10, the mark 74 can be visually confirmed under visible light. This structure can more easily determine the presence of the mark 74, and thus the presence of the siphon inducing member 5 can be more easily determined.

[0174] In the rainwater gutter system 10 , the ratio R1 of the inner diameter D1 of the reduced diameter portion 52 to the inner diameter D3b of the downpipe 3 is greater than or equal to 0.50 and less than or equal to 0.70. This structure can further improve the drainage capacity of the rainwater gutter system 10 .

[0175] In the rainwater gutter system 10, in the siphon inducing member 5, the length L1 from the upstream end 511 of the siphon inducing member 5 to the upstream end 52a of the reduced diameter portion 52 is at least 1 times the inner diameter D1 of the reduced diameter portion 52. This structure can further improve the drainage capacity of the rainwater gutter system 10.

[0176] In the rainwater gutter system 10, the distance L2 from the downstream end 52b of the reduced diameter portion 52 to the downstream end 3b of the downpipe 3 is 1.0 m or more. This structure can further improve the drainage capacity of the rainwater gutter system 10.

[0177] The siphon inducing member 5 described above is a siphon inducing member constituting a part of the rainwater pipe trough system 10, and the rainwater pipe trough system 10 constitutes the flow path 1a of rainwater. The rainwater pipe trough system 10 includes a downpipe 3 and a connecting portion 90 connecting the downspout 2d of the eave 2 and the upstream end 3a of the downpipe 3. The flow path cross-sectional area of ​​the eave 2 is 11000mm 2The inner diameter of the downpipe 3 is 67.0 mm or more. The wall thickness of the downpipe 3 is 2.2 mm or more. The siphon inducing member 5 is a cylindrical shape that can be arranged immediately below the connecting portion 90 in the flow path 1a, and has a reduced diameter portion 52 having a flow path cross-sectional area that is smaller than the flow path cross-sectional area of ​​the connecting portion 90. This structure can improve the drainage capacity while reducing the impact on the appearance.

[0178] The siphon inducing member 5 described above is a siphon inducing member constituting a part of the rainwater pipe trough system 10, and the rainwater pipe trough system 10 constitutes the flow path 1a of rainwater. The rainwater pipe trough system 10 includes a downpipe 3 connected to the downspout 2d of the eaves 2 and a connection joint 7 connecting the upstream end 3a of the downpipe 3 to the downspout 2d. The flow path cross-sectional area of ​​the eaves 2 is 11000mm 2 The inner diameter of the downpipe 3 is 67.0 mm or more. The wall thickness of the downpipe 3 is 2.2 mm or more. The siphon inducing member 5 is a cylindrical shape that can be arranged immediately below the connection joint 7 in the flow path 1a, and has a reduced diameter portion 52, and the reduced diameter portion 52 has a flow path cross-sectional area that is smaller than the flow path cross-sectional area of ​​the connection joint 7. This structure can improve the drainage capacity while reducing the impact on the appearance.

[0179] [1.3 Implementation method 3]

[0180] The present embodiment relates to a siphon inducing member, a piping member, and a piping system.

[0181] Japanese Patent Application Laid-Open No. 2021-124005 discloses a rainwater trough system, which includes an eaves, a downpipe, a connecting joint arranged downstream of the eaves and connected to the upper end of the downpipe, and a siphon joint having a reduced diameter and provided on the downpipe.

[0182] In this rainwater pipe trough system, the structure is as follows: the reduced diameter portion causes pressure loss and generates turbulence just below the reduced diameter portion, so that the siphon phenomenon is interrupted at the siphon joint.

[0183] The present embodiment provides a siphon inducing member, a piping member, and a piping system that can stably promote the action of the siphon phenomenon.

[0184] [1.3.1 Structure]

[0185] Fig.12 1 is a perspective view of a piping system 100 according to the present embodiment. The piping system 100 is used as a drainage system. The piping system 100 is a rainwater pipe system that receives rainwater from the roof of a building and flows it to a tank on the ground. The piping system 100 forms a flow path 100a of rainwater (see FIG. Fig.13 ).

[0186] The piping system 100 includes a gutter 102 , a vertical pipe 103 , a horizontal pipe 104 , bent pipes 105 - 1 and 105 - 2 , a piping member 106 , and a discharge pipe 110 .

[0187] The eaves 102 receives rainwater from the roof of the building. The eaves 102 is provided under the roof of the building. As an example, the eaves 102 is arranged at the eaves of the roof. In particular, the eaves 102 is arranged in a manner extending along the eaves of the roof. The eaves 102 is in the shape of an elongated barrel. The eaves 102 has a bottom wall 102a. On the bottom wall 102a, a water collection port 102b is formed in accordance with the overall design of the piping system 100. The water collection port 102b is, for example, a circular opening. The water collection port 102b is also referred to as a drain port or a downspout. As an example, the eaves 102 can be formed by extrusion molding of a resin material. The eaves 102 can have a core material for reinforcing the overall strength of the eaves 102. The core material can be made of metal, for example. As another example, the eaves 102 can also be formed by a metal plate, such as a steel plate (also referred to as a steel coil).

[0188] The discharge pipe 110 is disposed at the water collection port 102b of the eave 102. The discharge pipe 110 reduces the generation of vortices and the entrainment of air at the water collection port 102b. The discharge pipe 110 can help to generate a siphon phenomenon. The discharge pipe 110 can be a known structure.

[0189] The vertical pipe 103 defines a flow path in the vertical direction. The vertical pipe 103 is also called a downpipe in the rainwater pipe trough system. The vertical pipe 103 is provided to discharge rainwater from the water collection port 102b. The vertical pipe 103 allows rainwater from the water collection port 102b to flow vertically. The vertical pipe 103 is in the shape of a straight pipe. The cross section of the vertical pipe 103 that is perpendicular to the central axis is in a circular shape. The vertical pipe 103 is arranged in such a way that the direction of the central axis of the vertical pipe 103 is consistent with the up and down direction (vertical direction). The vertical pipe 103 is fixed to the wall of the building. The vertical pipe 103 has an upstream end 103a and a downstream end 103b. The upstream end 103a is the end of the vertical pipe 103 that is connected to the water collection port 102b ( Fig.12 The downstream end 103b is the end of the vertical pipe 103 inserted into the box bucket ( Fig.12 As an example, the material of the vertical pipe 103 is hard polyvinyl chloride. The dimensions, such as the shape and thickness of the vertical pipe 103, can be set according to the standard of hard polyvinyl chloride pipe (general) of JIS K 6741 "Hard polyvinyl chloride pipe".

[0190] Fig.13 is a side view of the piping system 100 with a portion omitted. Fig.14It is a partially omitted cross-sectional view of the piping system 100. In the piping system 100, the vertical pipe 103 is not directly connected to the water collection port 102b, but is connected to the water collection port 102b via the horizontal pipe 104 and the bent pipes 105-1 and 105-2.

[0191] In the present embodiment, the horizontal pipe 104 and the bent pipes 105 - 1 and 105 - 2 constitute a connection portion 101 . The connection portion 101 connects the water collection port 102 b of the gutter 102 and the upstream end 103 a of the vertical pipe 103 .

[0192] The horizontal pipe 104 defines a flow path in a direction intersecting the vertical direction. The horizontal pipe 104 is also called a horizontal branch pipe in the rainwater pipe trough system. The horizontal pipe 104 is a portion for allowing rainwater to flow from the water collection port 102b to the vertical pipe 103. The horizontal pipe 104 is located between the water collection port 102b and the vertical pipe 103. The horizontal pipe 104 is in the shape of a straight pipe. The cross section of the horizontal pipe 104 that is perpendicular to the central axis is circular. The horizontal pipe 104 is fixed in such a manner that the direction of the central axis of the horizontal pipe 104 is inclined relative to the up and down direction (vertical direction). The horizontal pipe 104 has an upstream end 104a and a downstream end 104b. The upstream end 104a is the end of the horizontal pipe 104 that is connected to the water collection port 102b ( Fig.12 The downstream end 104b is the end of the horizontal pipe 104 connected to the vertical pipe 103 ( Fig.12 As an example, the material of the horizontal pipe 104 is hard polyvinyl chloride. The dimensions, such as the shape and thickness of the horizontal pipe 104 can be set according to the standard of hard polyvinyl chloride pipe (general) of JIS K 6741 "Hard polyvinyl chloride pipe".

[0193] The bent pipes 105-1 and 105-2 change the direction of the flow path. The bent pipes 105-1 and 105-2 are, for example, connection joints that connect flow paths in different directions such as a vertical pipe and a horizontal pipe. The bent pipes 105-1 and 105-2 each have a socket 151 and 152 that connect the pipes on the upstream side and the downstream side, respectively, and a bent portion 150 that connects the sockets 151 and 152 to each other. The angle between the central axes of the sockets 151 and 152 is, for example, 91.17° as specified by JIS K 6739 "Hard polyvinyl chloride pipe joint for drainage". The corners of the inner and outer peripheral sides of the bent pipes 105-1 and 105-2 in the plane including the pipe axis are not rounded, but are approximately right-angled. As an example, the material of the bent pipes 105-1 and 105-2 is, for example, hard polyvinyl chloride. The dimensions of the bent pipes 105 - 1 and 105 - 2 may be set according to, for example, JIS K 6739 “Hard polyvinyl chloride pipe joint for drainage.” The bent pipes 105 - 1 and 105 - 2 may be 90° bend elbows (so-called DL) specified in JIS K 6739.

[0194] The bent pipe 105-1 is a first bent pipe that connects the vertical pipe 103 and the horizontal pipe 104. The bent pipe 105-1 connects the upstream end 103a of the vertical pipe 103 and the downstream end 104b of the horizontal pipe 104. In the bent pipe 105-1, the downstream end 104b of the horizontal pipe 104 is connected to the socket 151, and the upstream end 103a of the vertical pipe 103 is connected to the socket 152. The bent pipe 105-1 does not necessarily need to be a member that directly connects the upstream end 103a of the vertical pipe 103 and the downstream end 104b of the horizontal pipe 104, and may be a member that indirectly connects the upstream end 103a of the vertical pipe 103 and the downstream end 104b of the horizontal pipe 104 via other members.

[0195] The curved pipe 105-2 is a second curved pipe that connects the water collection port 102b to the transverse pipe 104. The curved pipe 105-2 connects the upstream end 104a of the transverse pipe 104 to the water collection port 102b. In the curved pipe 105-2, the water collection port 102b is connected to the socket 151 via the discharge pipe 110, and the upstream end 104a of the transverse pipe 104 is connected to the socket 152. The curved pipe 105-2 does not have to be a component that directly connects the upstream end 104a of the transverse pipe 104 to the water collection port 102b, and may be a component that indirectly connects the upstream end 104a of the transverse pipe 104 to the water collection port 102b via other components.

[0196] Fig.15 It is an exploded perspective view with a portion omitted of the piping system 100 . The piping member 106 is connected between the socket 152 of the bent pipe 105 - 1 and the end 103 a on the upstream side of the riser 103 .

[0197] Fig.16 It is an exploded perspective view of the piping member 106. The piping member 106 includes a siphon inducing member 107, a straight pipe member 108, and a joint member 109.

[0198] The straight pipe member 108 is in a straight pipe shape. The cross section of the straight pipe member 108 perpendicular to the central axis is circular. The straight pipe member 108 has an upstream end 108a and a downstream end 108b. The upstream end 108a is the end of the straight pipe member 108 connected to the socket 152 of the curved pipe 105-1 ( Fig.15 The downstream end 108b is the end of the straight pipe member 108 into which the joint member 109 is inserted ( Fig.16As an example, the material of the straight pipe member 108 is hard polyvinyl chloride. The straight pipe member 108 is a shape and size that can be connected to the socket 151 of the curved pipe 105-1 instead of the vertical pipe 103. The size of the straight pipe member 108, such as the outer shape and thickness, can be set according to the standard of hard polyvinyl chloride pipe (general) of JIS K 6741 "Hard polyvinyl chloride pipe". In this embodiment, the outer diameter of the straight pipe member 108 is equal to the outer diameter of the vertical pipe 103. The inner diameter of the straight pipe member 108 is equal to the inner diameter of the vertical pipe 103.

[0199] Reference Fig.14 as well as Fig.16 In particular, the siphon inducing member 107 constitutes a part of the piping system 100, and the piping system 100 constitutes the flow path 100a. The siphon inducing member 107 has a first end 107a and a second end 107b facing the upstream side and the downstream side of the piping system 100, respectively, and is in a cylindrical shape having an inner peripheral surface 170 that defines the cross-sectional area of ​​the flow path. The siphon inducing member 107 includes a reduced diameter portion 171, an expanded diameter portion 172, and a protrusion 173.

[0200] Reference Figure 17 to Figure 23 The siphon inducing member 107 will be further described. Fig.17 It is an exploded perspective view of the siphon inducing member 107 when viewed from above. Fig.18 This is an exploded perspective view of the siphon inducing member 107 when viewed from below. Fig.19 107 is a top view of the siphon inducing member 107 . Fig. 20 107 is a bottom view of the siphon inducing member 107 . Fig.21 It is a bottom view of the reduced diameter portion 171 of the siphon inducing member 107 . Fig. 22 It is a top view of the enlarged diameter portion 172 of the siphon inducing member 107 . Fig.23 is a cross-sectional view of the siphon inducing member 107 .

[0201] Reference Fig.23 In particular, the cross-sectional area of ​​the flow path of the reduced diameter portion 171 decreases as it moves from the first end 107a to the second end 107b. The cross-sectional area of ​​the flow path of the expanded diameter portion 172 increases as it moves from the reduced diameter portion 171 to the second end 107b. Thus, the siphon inducing member 107 has the effect of inducing the siphon phenomenon in the piping system 100 or stably promoting the effect brought about by the siphon phenomenon in the piping system 100.

[0202] In this embodiment, the reduced diameter portion 171 and the enlarged diameter portion 172 are separate components. The reduced diameter portion 171 constitutes the upstream portion of the siphon inducing member 107. The enlarged diameter portion 172 constitutes the downstream portion of the siphon inducing member 107. The reduced diameter portion 171 and the enlarged diameter portion 172 are made of, for example, hard polyvinyl chloride.

[0203] Reference Fig.17 as well as Fig.18 Specifically, the reduced diameter portion 171 includes a first flange portion 171 a and a first cylindrical portion 171 b .

[0204] The first flange portion 171a is annular and defines the first end 107a.

[0205] The first cylindrical portion 171b extends from the inner circumference of the first flange portion 171a toward the second end 107b. The first cylindrical portion 171b defines the third end 107c on the opposite side of the first end 107a. The first cylindrical portion 171b is cylindrical and has a first inner circumferential surface 170a defining the cross-sectional area of ​​the flow path. The first inner circumferential surface 170a is a portion on the upstream side of the inner circumferential surface 170 of the siphon inducing member 107. The first cylindrical portion 171b decreases in inner diameter and outer diameter in a manner that the cross-sectional area of ​​the flow path decreases from the first end 107a toward the third end 107c. The first protrusion 173a of the protrusion 173 is formed on the first cylindrical portion 171b, and the details thereof will be described later. The inner diameter of the first cylindrical portion 171b is the diameter of the inscribed circle of the portion of the first inner circumferential surface 170a of the first cylindrical portion 171b where the first protrusion 173a does not exist. The outer diameter of the first cylindrical portion 171 b is the diameter of a circumscribed circle of a portion of the outer peripheral surface of the first cylindrical portion 171 b where the first protrusion 173 a does not exist.

[0206] The outer diameter of the first flange portion 171 a is the maximum value of the outer diameter of the reduced diameter portion 171 . The minimum value of the inner diameter of the first cylindrical portion 171 b (corresponding to the inner diameter at the third end 107 c ) is the minimum value of the inner diameter of the reduced diameter portion 171 .

[0207] Reference Fig.19 as well as Fig.21 The reduced diameter portion 171 has a first through hole 174a. The first through hole 174a penetrates the first flange portion 171a. In this embodiment, there are four first through holes 174a. The four first through holes 174a are arranged at equal intervals around the central axis C10 when viewed from the direction of the central axis C10 of the siphon inducing member 107.

[0208] Reference Fig.19 as well as Fig.21In terms of the reduced diameter portion 171, there are first concave-convex portions for coupling with the expanded diameter portion 172. In the present embodiment, there are four first concave-convex portions 1751a to 1751d. The four first concave-convex portions 1751a to 1751d are located at the third end 107c on the opposite side of the first end 107a. The four first concave-convex portions 1751a to 1751d are arranged at equal intervals around the central axis C10 when viewed from the direction of the central axis C10 of the siphon inducing member 107. In the present embodiment, the first concave-convex portions 1751a and 1751b are circular holes, and the first concave-convex portions 1751c and 1751d are circular protrusions.

[0209] Reference Fig.17 as well as Fig.18 Specifically, the enlarged diameter portion 172 includes a second flange portion 172 a and a second cylinder portion 172 b .

[0210] The second flange portion 172a is annular and defines the second end 107b.

[0211] The second cylinder portion 172b extends from the inner circumference of the second flange portion 172a toward the first end 107a. The second cylinder portion 172b defines the fourth end 107d on the opposite side of the second end 107b. The second cylinder portion 172b is cylindrical and has a second inner circumferential surface 170b defining the flow path cross-sectional area of ​​the expanded diameter portion 172. The second inner circumferential surface 170b is a portion on the downstream side of the inner circumferential surface 170 of the siphon inducing member 107. The inner circumferential surface 170 is formed by the first inner circumferential surface 170a and the second inner circumferential surface 170b. The second cylinder portion 172b increases in inner diameter and outer diameter as the flow path cross-sectional area increases from the fourth end 107d toward the second end 107b. A second protrusion 173b of the protrusion 173 is formed on the second cylinder portion 172b, and details will be described later. The inner diameter of the second cylinder 172b is the diameter of the inscribed circle of the portion of the second inner circumferential surface 170b of the second cylinder 172b where the second protrusion 173b does not exist. The outer diameter of the second cylinder 172b is the diameter of the circumscribed circle of the portion of the outer circumferential surface of the second cylinder 172b where the second protrusion 173b does not exist.

[0212] The outer diameter of the second flange portion 172 a is the maximum value of the outer diameter of the diameter-enlarged portion 172 . The minimum value of the inner diameter of the second cylindrical portion 172 b (corresponding to the inner diameter at the fourth end 107 d ) is the minimum value of the inner diameter of the diameter-enlarged portion 172 .

[0213] Reference Fig. 20 as well as Fig. 22The enlarged diameter portion 172 has a second through hole 174b. The second through hole 174b penetrates the second flange portion 172a. In this embodiment, there are four second through holes 174b. The four second through holes 174b are arranged at equal intervals around the central axis C10 when viewed from the direction of the central axis C10 of the siphon inducing member 107.

[0214] Reference Fig. 20 as well as Fig. 22 In terms of the expansion portion 172, the expansion portion 172 has a second concave-convex portion for combining with the reduction portion 171. In the present embodiment, there are four second concave-convex portions 1752a to 1752d. The four second concave-convex portions 1752a to 1752d are located at the fourth end 107d on the opposite side of the second end 107b. The four second concave-convex portions 1752a to 1752d are arranged at equal intervals around the central axis C10 when viewed from the direction of the central axis C10 of the siphon inducing member 107. In the present embodiment, the second concave-convex portions 1752a and 1752b are circular protrusions, and the second concave-convex portions 1752c and 1752d are circular holes. The four second concave-convex portions 1752a to 1752d are mechanically combined with the four first concave-convex portions 1751a to 1751d, respectively. That is, the second concave-convex part 1752a is inserted into the first concave-convex part 1751a, the second concave-convex part 1752b is inserted into the first concave-convex part 1751b, the first concave-convex part 1751c is inserted into the second concave-convex part 1752c, and the first concave-convex part 1751d is inserted into the second concave-convex part 1752d. The first concave-convex parts 1751a to 1751d and the second concave-convex parts 1752a to 1752d can realize the combination and alignment of the reduced diameter part 171 and the expanded diameter part 172.

[0215] Reference Fig.19 as well as Fig. 20 In particular, the protrusions 173 are located on the inner circumferential surface 170 of the siphon inducing member 107. In the present embodiment, the siphon inducing member 107 includes a plurality of (12 in the illustrated example) protrusions 173. The plurality of protrusions 173 are arranged at equal intervals around the central axis C10 when viewed from the direction of the central axis C10 of the siphon inducing member 107. In other words, the plurality of protrusions 173 are located on the inner circumferential surface 170 at positions that are rotationally symmetrical with respect to the central axis C10 when viewed from the direction of the central axis C10.

[0216] The plurality of protrusions 173 are used to rectify the flow of fluid (rainwater in the rainwater pipe system). That is, the plurality of protrusions 173 function as rectifying members that rectify the flow of the fluid flowing into the siphon inducing member 107. In this embodiment, the plurality of protrusions 173 have the same shape and size.

[0217] Reference Fig.23In terms of the protrusion 173, the protrusion 173 is not in the shape of a plate extending along the central axis C10 of the siphon inducing member 107. The protrusion 173 has a first front end 1731 located at the reduced diameter portion 171 and a second front end 1732 located at the expanded diameter portion 172. The straight line C20 connecting the first front end 1731 and the second front end 1732 is inclined relative to the central axis C10 of the siphon inducing member 107. Thus, the protrusion 173 can be expected to have the effect of causing the fluid to revolve around the central axis C10 of the siphon inducing member 107. Therefore, the protrusion 173 can be expected to have the effect of increasing or maintaining the flow velocity of the fluid. Thus, the drainage capacity can be improved.

[0218] Reference Fig.19 as well as Fig. 20 In terms of the protrusion 173, the protrusion 173 is not a plate-shaped with uniform width. In the reduced diameter portion 171, the width of the protrusion 173 becomes wider as it goes from the first end 107a to the second end 107b. In the expanded diameter portion 172, the width of the protrusion 173 becomes narrower as it goes from the first end 107a to the second end 107b. Thus, the protrusion 173 can easily make the fluid rotate around the central axis C10 of the siphon inducing member 107 compared with the case where the width is uniform. Therefore, the protrusion 173 can be expected to increase or maintain the flow velocity of the fluid. Thus, the drainage capacity can be improved.

[0219] Reference Fig.19 as well as Fig. 20 In the reduced diameter portion 171, the height of the protrusion 173 increases as it moves from the first end 107a to the second end 107b. In the expanded diameter portion 172, the height of the protrusion 173 decreases as it moves from the first end 107a to the second end 107b. Thus, the protrusion 173 can reduce the resistance to the flow of the fluid compared to the case where the height is uniform. Therefore, the protrusion 173 can be expected to increase or maintain the flow velocity of the fluid. Thus, the drainage capacity can be improved.

[0220] In the present embodiment, the protrusion 173 is composed of a first protrusion portion 173 a and a second protrusion portion 173 b .

[0221] Reference Fig.17 , Fig.18 , Fig.19 as well as Fig.21 In particular, the first protrusion 173a is located on the first inner peripheral surface 170a of the reduced diameter portion 171. The first protrusion 173a corresponds to the upstream side of the protrusion 173. The first protrusion 173a is integrally formed on the first inner peripheral surface 170a of the reduced diameter portion 171. In the present embodiment, the first protrusion 173a is integrally formed on the first inner peripheral surface 170a in such a manner that the first cylindrical portion 171b of the reduced diameter portion 171 partially protrudes.

[0222] Reference Fig.17 , Fig.18 , Fig. 20 as well as Fig. 22 In particular, the second protrusion 173b is located on the second inner peripheral surface 170b of the enlarged diameter portion 172. The second protrusion 173b corresponds to the downstream side of the protrusion 173. The second protrusion 173b is integrally formed on the second inner peripheral surface 170b of the enlarged diameter portion 172. In the present embodiment, the second protrusion 173b is integrally formed on the second inner peripheral surface 170b in such a manner that the second cylinder portion 172b of the enlarged diameter portion 172 partially protrudes.

[0223] In the present embodiment, the first protrusion 173 a and the second protrusion 173 b have the same shape.

[0224] The siphon inducing member 107 is assembled by combining the reduced diameter portion 171 with the expanded diameter portion 172. More specifically, the third end 107c of the reduced diameter portion 171 and the fourth end 107d of the expanded diameter portion 172 are placed opposite to each other, and the first concave-convex portions 1751a to 1751d and the second concave-convex portions 1752a to 1752d are mechanically combined with each other. Fig.16 Siphon inducing member 107 is obtained as shown. In siphon inducing member 107, inner peripheral surface 170 is formed by first inner peripheral surface 170a of reduced diameter portion 171 and second inner peripheral surface 170b of expanded diameter portion 172. In siphon inducing member 107, protrusion 173 is formed by first protrusion 173a of reduced diameter portion 171 and second protrusion 173b of expanded diameter portion 172.

[0225] In the present embodiment, the reduced diameter portion 171 and the expanded diameter portion 172 are configured as components of the same shape and size. In the siphon inducing member 107, one of the two components of the same shape and size is used as the reduced diameter portion 171, and the other is used as the expanded diameter portion 172. The shape of the reduced diameter portion 171 can be consistent with the shape of the expanded diameter portion 172 when rotated 180 degrees relative to a rotation axis orthogonal to the central axis C10 of the siphon inducing member 107. More specifically, the first flange portion 171a, the first cylinder portion 171b, the first protrusion 173a and the first through hole 174a of the reduced diameter portion 171 and the second flange portion 172a, the second cylinder portion 172b, the second protrusion 173b and the second through hole 174b of the expanded diameter portion 172 are respectively of the same shape and size. Regarding the first concave-convex parts 1751a to 1751d and the second concave-convex parts 1752a to 1752d, the first concave-convex parts 1751a and 1751b and the second concave-convex parts 1752c and 1752d have the same shape and size, and the first concave-convex parts 1751c and 1751d and the second concave-convex parts 1752a and 1752b have the same shape and size. The two holes of the first concave-convex parts 1751a and 1751b are shaped so that the two protrusions of the first concave-convex parts 1751c and 1751d can be inserted. Similarly, the two holes of the second concave-convex parts 1752c and 1752d are shaped so that the two protrusions of the second concave-convex parts 1752a and 1752b can be inserted. As a result, it is not necessary to prepare two parts of different shapes for the reduced diameter part 171 and the expanded diameter part 172, and the siphon inducing member 107 can be formed by using two parts of the same shape and size. Therefore, for example, it is expected that the cost required for preparing the mold can be significantly reduced. Therefore, it is expected that the assembly of the siphon inducing member 107 can be simplified and the manufacturing cost can be reduced. Therefore, this structure can facilitate the manufacturing of the siphon inducing member 107.

[0226] The siphon inducing member 107 has a maximum outer diameter at the first end 107a and the second end 107b. The outer diameter of the first flange portion 171a and the outer diameter of the second flange portion 172a are less than the inner diameter of the straight tube member 108. The inner diameter of the siphon inducing member 107 is maximum at the first end 107a and the second end 107b, and is minimum at the third end 107c and the fourth end 107d.

[0227] When the siphon inducing member 107 is located in the straight tube member 108, a space can be formed between the first flange portion 171a, the first cylinder portion 171b, the second flange portion 172a, and the second cylinder portion 172b of the siphon inducing member 107 and the straight tube member 108. Sometimes, a fluid enters the space from the gap between the straight tube member 108 and the first flange portion 171a. When the fluid is water, it sometimes freezes due to a drop in temperature. In this case, the water expands as ice, and thus, there is a possibility that the siphon inducing member 107 or the straight tube member 108 is damaged. However, in the present embodiment, the siphon inducing member 107 is provided with a second through hole 174b that penetrates the second flange portion 172a. Therefore, the water that has entered the above-mentioned space can be discharged from the second through hole 174b. As a result, the possibility of damage to the siphon inducing member 107 or the straight tube member 108 caused by water accumulation in the above-mentioned space can be reduced. That is, the second through hole 174b functions as a drain hole.

[0228] Reference Fig.15 In particular, the joint member 109 has a first socket 191 and a second socket 192. The first socket 191 is a socket facing the upstream side of the piping system 100 and connected to the straight pipe member 108. The second socket 192 is a socket that can connect a piping element having the same outer diameter as the straight pipe member 108. In the present embodiment, the piping element having the same outer diameter as the straight pipe member 108 is the riser 103.

[0229] Fig.24 109 is a top view of the joint member 109 . Fig.25 It is a bottom view of the joint member 109 . Fig.26 is a cross-sectional view of the joint member 109 .

[0230] The joint member 109 includes a main body portion 190, a partition wall portion 193, and a peripheral wall portion 194. The material of the joint member 109 is, for example, hard polyvinyl chloride.

[0231] The main body 190 is in the shape of a straight tube. The cross section of the main body 190 perpendicular to the central axis is circular. The main body 190 has an upstream end 109a and a downstream end 109b. The dimensions of the main body 190, such as the outer shape and thickness, can be set according to the standard of the socket of JIS K 6739 "Hard polyvinyl chloride pipe joint for drainage". In this embodiment, the inner diameter of the main body 190 is greater than the outer diameter of the straight pipe member 108.

[0232] Reference Fig.24 as well as Fig.26In particular, the partition wall 193 extends from the inner peripheral surface 190a of the main body 190 toward the central axis side of the main body 190. The partition wall 193 is a plate-shaped body with a uniform thickness. The partition wall 193 has an opening 193a. The opening 193a is located at the center of the partition wall 193. Fig.24 as well as Fig.25 In particular, when viewed from the central axis of the main body 190 , the opening 193a is circular and the partition wall 193 is annular. The inner diameter of the opening 193a is equal to the inner diameters of the first end 107a and the second end 107b of the siphon inducing member 107 .

[0233] Reference Fig.26 In particular, the peripheral wall portion 194 protrudes from the edge of the opening 193a of the partition wall portion 193 toward the downstream end portion 109b. Fig.25 In other words, the peripheral wall portion 194 surrounds the entire circumference of the opening 193a. In the present embodiment, the peripheral wall portion 194 is cylindrical. The outer diameter of the peripheral wall portion 194 is smaller than the inner diameter of the main body portion 190. Thus, an annular gap 195 exists between the inner peripheral surface 190a of the main body portion 190 and the peripheral wall portion 194. The upstream end portion 103a of the vertical pipe 103 is inserted into the gap 195.

[0234] Reference Fig.26 In the joint member 109, the portion of the partition wall portion 193 and the main body portion 190 on the side of the end 109a which is closer to the upstream side than the partition wall portion 193 constitutes a first socket 191, and the portion of the partition wall portion 193 and the main body portion 190 on the side of the end 109b which is closer to the downstream side than the partition wall portion 193 constitutes a second socket 192.

[0235] As described above, the pipe member 106 includes the siphon inducing member 107, the straight pipe member 108, and the joint member 109. Fig.14 In the piping member 106, the siphon inducing member 107 is located inside the straight pipe member 108. For example, the siphon inducing member 107 can be fixed by applying an adhesive between the outer peripheral portion of the first flange portion 171a and the second flange portion 172a and the inner peripheral surface of the straight pipe member 108. The end portion 108b on the downstream side of the straight pipe member 108 is inserted into the first socket 191 of the joint member 109. The straight pipe member 108 can be fixed by applying an adhesive between the outer peripheral portion of the end portion 108b on the downstream side and the inner peripheral surface of the first socket 191.

[0236] The pipe member 106 is located between the first curved pipe 105-1 and the vertical pipe 103 in the piping system 100 in such a manner that the straight pipe member 108 is connected to the first curved pipe 105-1 and the vertical pipe 103 is connected to the second socket 192 of the joint member 109. The straight pipe member 108 can be fixed by applying an adhesive between the outer peripheral portion of the upstream end portion 108a and the inner peripheral surface of the socket 152 of the first curved pipe 105-1. The joint member 109 can be fixed by applying an adhesive between the inner peripheral surface of the second socket 192 and the outer peripheral portion of the upstream end portion 103a of the vertical pipe 103.

[0237] Next, the function of the siphon inducing member 107 will be described. As described above, the siphon inducing member 107 has the reduced diameter portion 171, and partially reduces the flow path cross-sectional area of ​​the flow path 100a of the piping system 100. Therefore, the flow rate of rainwater flowing into the reduced diameter portion 171 from the upstream side of the flow path 100a tends to be larger than the flow rate of rainwater flowing out from the reduced diameter portion 171 to the downstream side of the flow path 100a. Therefore, rainwater tends to accumulate in the reduced diameter portion 171. When rainwater accumulates in the reduced diameter portion 171, the position on the downstream side of the flow path 100a relative to the reduced diameter portion 171 tends to become full of water. Therefore, it is considered that the rainwater in the reduced diameter portion 171 is led away by the rainwater on the downstream side of the flow path 100a relative to the reduced diameter portion 171, and the siphon phenomenon occurs, and the rainwater in the piping system 100 flows violently toward the downstream side. It should be noted that the full water state is not used in a strict sense, and also includes a state that is filled with water to a degree that can be regarded as the full water state (a state close to the full water state). The siphon inducing member 107 has an expanded diameter portion 172 downstream of the reduced diameter portion 171, and increases the flow path cross-sectional area of ​​the flow path 100a of the piping system 100 after partially reducing it. It is easy to guide rainwater passing through the reduced diameter portion 171 in a direction away from the central axis C10 of the siphon inducing member 107, and further stably promote the effect brought about by the siphon phenomenon.

[0238] Next, the arrangement of the siphon inducing member 107 in the piping system 100 will be described. In the piping system 100, the piping member 106 is located between the first curved pipe 105-1 and the vertical pipe 103 in such a manner that the straight pipe member 108 is connected to the first curved pipe 105-1 and the vertical pipe 103 is connected to the second socket 192 of the joint member 109. The siphon inducing member 107 is located inside the straight pipe member 108 of the piping member 106. Thus, the siphon inducing member 107 is located inside the straight pipe member 108 located immediately below the first curved pipe 105-1 in the flow path 100a of the piping system 100. That is, the siphon inducing member 107 is located immediately below the connection portion 101 in the flow path 100a of the piping system 100. In the design of the piping system 100, the first curved pipe 105-1 is often located above the head of a person. Therefore, the siphon inducing member 107 is also located above the head of a person. That is, compared with the case where the siphon inducing member 107 is arranged separately from the first curved pipe 105-1 downward, the siphon inducing member 107 can be made less conspicuous in the appearance of the piping system 100. As a result, the drainage capacity can be improved while reducing the impact on the appearance. In the present invention, "the straight pipe member 108 is located immediately below the first curved pipe 105-1 in the flow path" does not exclude the presence of a member that does not substantially affect the structure of the flow path between the first curved pipe 105-1 and the straight pipe member 108. In other words, it can also be said that the straight pipe member 108 is directly connected to the first curved pipe 105-1 without sandwiching other piping elements.

[0239] In the present embodiment, the siphon inducing member 107 is hidden by the straight pipe member 108. Therefore, the siphon inducing member 107 cannot be directly visually confirmed from the appearance of the piping system 100. Therefore, even if the siphon inducing member 107 is arranged, it does not substantially affect the appearance of the piping system 100. That is, the drainage capacity can be improved while reducing the impact on the appearance.

[0240] Next, various dimensions in the piping system 100 will be further described.

[0241] [Reduction ratio]

[0242] In this embodiment, the outer diameter of the siphon inducing member 107 corresponds to the inner diameter of the straight pipe member 108. The inner diameter of the straight pipe member 108 corresponds to the inner diameter of the riser pipe 103. The outer diameter of the siphon inducing member 107 corresponds to the inner diameter of the flow path of the piping system 100. Figure 19 to Figure 22Here, the outer diameter of the siphon inducing member 107 is set to P, and the inner diameter of the siphon inducing member 107 where the flow path cross-sectional area becomes the smallest is set to P1. The inner diameter where the flow path cross-sectional area becomes the smallest in the siphon inducing member 107 is the inner diameter at the third end 107c or the fourth end 107d. When the reduction ratio is set to R, it is R=P1 / P. After evaluating the drainage capacity (drainage, drainage performance) of the piping system 100 when R is changed through a drainage experiment, the results of Table 3 below were obtained. In Table 3 below, the drainage capacity is evaluated in three levels of "0", "△", and "×". "0" means that no overflow occurs. "△" means that overflow sometimes occurs. "×" means that overflow occurs with a high probability.

[0243] [Table 3]

[0244]

[0245] According to Table 3, R is preferably greater than or equal to 0.50 and less than or equal to 0.75. Thus, the drainage capacity of the piping system 100 can be further improved. In addition, R may be greater than or equal to 0.50 and less than or equal to 0.67. Thus, the drainage capacity of the piping system 100 can be further improved. In addition, R may be greater than or equal to 0.55 and less than or equal to 0.70. Thus, the drainage capacity of the piping system 100 can be further improved. In addition, R may be greater than or equal to 0.55 and less than or equal to 0.67. Thus, the drainage capacity of the piping system 100 can be further improved.

[0246] [Ratio of the length of the siphon inducing member to the inner diameter]

[0247] Reference Fig.23 In particular, the siphon inducing member 107 has an expanded diameter portion 172 in addition to the reduced diameter portion 171. When the length of the siphon inducing member 107 is set to H, the length of the reduced diameter portion 171 is set to H1, and the length of the expanded diameter portion 172 is set to H2, H=H1+H2. In the present embodiment, H1=H2. The length referred to here is the dimension in the direction of the central axis C10 of the siphon inducing member 107. The drainage capacity of the piping system 100 was evaluated by changing the ratio (=H / P1) of the length H of the siphon inducing member 107 to the inner diameter P1 of the siphon inducing member 107 where the flow path cross-sectional area is the smallest through a drainage experiment. As a result, when H / P1 is less than 1, overflow is found, but when H / P1 is greater than 1, overflow cannot be confirmed. Therefore, it is better that H / P1 is greater than 1. In other words, when the length of the siphon inducing member 107 is H and the inner diameter of the siphon inducing member 107 where the flow path cross-sectional area is the smallest is P1, H≥P1 is preferably satisfied. This structure can improve the drainage capacity.

[0248] [Distance between the upstream end of the straight pipe member and the first socket]

[0249] There is a view that when the siphon inducing member 107 is not disposed immediately below the first curved pipe 105-1 but is disposed downwardly away from the first curved pipe 105-1, the drainage capacity is improved more significantly as the distance between the siphon inducing member 107 and the first curved pipe 105-1 increases. Fig.15 In terms of the distance between the siphon inducing member 107 and the first curved pipe 105-1, the distance L between the upstream end 108a of the straight pipe member 108 and the first bellmouth 191 is limited. Even in the case where the siphon inducing member 107 is located immediately below the first curved pipe 105-1, it can be confirmed through experiments that the drainage capacity is expected to be improved by about 2 times compared to the case where the siphon inducing member 107 does not exist. For example, in the case of a relatively small-scale building, it is believed that the drainage capacity is improved by about 2 times. When considering the drainage capacity required for such a relatively small-scale building, the distance L between the upstream end 108a of the straight pipe member 108 and the first bellmouth 191 is preferably 50 mm or more. On the other hand, when the distance L is increased, the joint member 109 is easily noticeable, which is not preferred in terms of the appearance of the piping system 100. Therefore, the distance L between the upstream end 108a of the straight pipe member 108 and the first socket 191 is preferably 1000 mm or less, and more preferably 200 mm or less. In this way, the piping system 100 does not affect the appearance in a small-scale object, and can obtain drainage capacity while easing construction restrictions. That is, according to the piping system 100, both the appearance and the drainage capacity can be improved.

[0250] [Length of vertical pipe]

[0251] In the piping system 100, a piping member 106 having a siphon inducing member 107 is arranged between the first curved pipe 105-1 and the vertical pipe 103. The height of the siphon inducing member 107 is limited by the length of the vertical pipe 103. Therefore, the drainage capacity of the piping system 100 was evaluated with respect to the length of the vertical pipe 103 through a drainage experiment. Through this evaluation, the results of Table 4 below were obtained. In Table 4 below, the drainage capacity was evaluated in three levels: "0", "△", and "×". "0" means that no overflow occurs. "△" means that overflow sometimes occurs. "×" means that overflow occurs with a high probability.

[0252] [Table 4]

[0253]

[0254] According to Table 4, the length of the vertical pipe 103 is preferably 1.0 m or more. Thus, the drainage capacity of the piping system 100 can be further improved. In addition, the length of the vertical pipe 103 can be 1.1 m or more. Thus, the drainage capacity of the piping system 100 can be further improved. In addition, the length of the vertical pipe 103 can be 1.2 m or more. Thus, the drainage capacity of the piping system 100 can be further improved.

[0255] [1.3.2 Effects, etc.]

[0256] The rainwater pipe trough system (piping system 100) described above is a rainwater pipe trough system that constitutes a flow path 100a of rainwater, and includes a downpipe (vertical pipe 103), a connection portion 101 that connects the downspout (water collection port 102b) of the eave 102 to the upstream end (end 103a) of the downpipe (vertical pipe 103), and a siphon inducing member 107. The flow path cross-sectional area of ​​the eave 102 is 11000mm 2 The inner diameter of the downpipe (vertical pipe 103) is 67.0 mm or more. The wall thickness of the downpipe (vertical pipe 103) is 2.2 mm or more. The siphon inducing member 107 is cylindrical and has a reduced diameter portion 171, and the reduced diameter portion 171 has a flow path cross-sectional area smaller than the flow path cross-sectional area of ​​the connecting portion 101. The siphon inducing member 107 is located immediately below the connecting portion 101 in the flow path 100a. This structure can improve the drainage capacity while reducing the impact on the appearance.

[0257] The siphon inducing member 107 described above is a siphon inducing member that constitutes a part of the rainwater pipe trough system (piping system 100), and the rainwater pipe trough system (piping system 100) constitutes the flow path 100a of rainwater. The rainwater pipe trough system (piping system 100) includes a downpipe (vertical pipe 103) and a connecting portion 101 that connects the downspout (water collection port 102b) of the eave 102 to the upstream end (end 103a) of the downspout (vertical pipe 103). The flow path cross-sectional area of ​​the eave 102 is 11000mm 2 The inner diameter of the downpipe (vertical pipe 103) is 67.0 mm or more. The wall thickness of the downpipe (vertical pipe 103) is 2.2 mm or more. The siphon inducing member 107 is a cylindrical shape that can be arranged immediately below the connecting portion 101 in the flow path 100a, and has a reduced diameter portion 171, and the reduced diameter portion 171 has a flow path cross-sectional area that is smaller than the flow path cross-sectional area of ​​the connecting portion 101. This structure can improve the drainage capacity while reducing the impact on the appearance.

[0258] In the present embodiment, the siphon inducing member 107 has a first end 107a and a second end 107b facing the upstream side and the downstream side of the rainwater pipe trough system (piping system 100), respectively, and is cylindrical with an inner peripheral surface 170 that defines the flow path cross-sectional area. The siphon inducing member 107 also has an expanded diameter portion 172. The flow path cross-sectional area of ​​the reduced diameter portion 171 decreases as it moves from the first end 107a toward the second end 107b. The flow path cross-sectional area of ​​the expanded diameter portion 172 increases as it moves from the reduced diameter portion 171 toward the second end 107b. This structure can stably promote the effect brought about by the siphon phenomenon.

[0259] The siphon inducing member 107 described above constitutes a part of the piping system 100, and the piping system 100 constitutes the flow path 100a. The siphon inducing member 107 has a first end 107a and a second end 107b facing the upstream side and the downstream side of the piping system 100, respectively, and is in a cylindrical shape having an inner peripheral surface 170 that defines the cross-sectional area of ​​the flow path. The siphon inducing member 107 has a reduced diameter portion 171 whose cross-sectional area of ​​the flow path decreases as it moves from the first end 107a to the second end 107b, and an expanded diameter portion 172 whose cross-sectional area of ​​the flow path increases as it moves from the reduced diameter portion 171 to the second end 107b. This structure can stably promote the effect brought about by the siphon phenomenon.

[0260] In the siphon inducing member 107, when the outer diameter of the siphon inducing member 107 is P and the inner diameter of the siphon inducing member 107 where the flow path cross-sectional area is the smallest is P1, 0.50<P1 / P<0.75. This structure can further improve the drainage capacity.

[0261] The siphon inducing member 107 includes a protrusion 173 located on the inner peripheral surface 170. The protrusion 173 has a first front end 1731 located at the reduced diameter portion 171 and a second front end 1732 located at the expanded diameter portion 172. A straight line C20 connecting the first front end 1731 and the second front end 1732 is inclined relative to the central axis C10 of the siphon inducing member 107. This structure can further improve the drainage capability.

[0262] In the siphon inducing member 107, the width of the protrusion 173 increases from the first end 107a to the second end 107b in the reduced diameter portion 171. The width of the protrusion 173 decreases from the first end 107a to the second end 107b in the expanded diameter portion 172. This structure can further improve the drainage capability.

[0263] In the siphon inducing member 107, the height of the protrusion 173 increases from the first end 107a to the second end 107b in the reduced diameter portion 171. The height of the protrusion 173 decreases from the first end 107a to the second end 107b in the expanded diameter portion 172. This structure can further improve the drainage capability.

[0264] The siphon inducing member 107 includes a plurality of protrusions 173. The plurality of protrusions 173 are arranged at equal intervals around the central axis C10 when viewed from the direction of the central axis C10 of the siphon inducing member 107. This structure can further improve the drainage capability.

[0265] The siphon inducing member 107 has the largest outer diameter at the first end 107a and the second end 107b. This structure can facilitate the manufacture of the siphon inducing member 107.

[0266] In the siphon inducing member 107, the length of the reduced diameter portion 171 is equal to the length of the expanded diameter portion 172. This structure can facilitate the manufacture of the siphon inducing member 107.

[0267] In the siphon inducing member 107, the reduced diameter portion 171 and the expanded diameter portion 172 are independent components. The reduced diameter portion 171 has first concave-convex portions 1751a to 1751d at the third end 107c on the side opposite to the first end 107a. The expanded diameter portion 172 has second concave-convex portions 752a to 752d mechanically coupled to the first concave-convex portions 1751a to 1751d at the fourth end 107d on the side opposite to the second end 107b. The reduced diameter portion 171 and the expanded diameter portion 172 are coupled to each other by mechanically coupling the first concave-convex portions 1751a to 1751d and the second concave-convex portions 1752a to 1752d. This structure can facilitate the manufacture of the siphon inducing member 107.

[0268] In the siphon inducing member 107 , the reduced diameter portion 171 and the expanded diameter portion 172 are formed of members of the same shape. This structure can facilitate the manufacture of the siphon inducing member 107 .

[0269] In the siphon inducing member 107 , when the length of the siphon inducing member 107 is H and the inner diameter of the siphon inducing member 107 where the flow path cross-sectional area is minimized is P1 , H≥P1 . This structure can further improve the drainage capability.

[0270] The piping member 106 described above includes: a siphon inducing member 107; a straight pipe member 108, inside which the siphon inducing member 107 is arranged; and a joint member 109, which has a first socket 191 facing the upstream side of the piping system 100 and connected to the straight pipe member 108, and a second socket 192 facing the downstream side of the piping system 100 and capable of connecting a piping element (vertical pipe 103) having the same outer diameter as the straight pipe member 108. This structure can stably promote the effect brought about by the siphon phenomenon while reducing the influence on the appearance, and can improve the drainage capacity.

[0271] In the pipe member 106, the distance between the upstream end 108a of the straight pipe member 108 and the first bellmouth 191 is 50 mm or more and 1000 mm or less. This structure can improve the drainage capacity.

[0272] The piping system 100 described above includes a vertical pipe 103 fixed to the wall surface of a building, a horizontal pipe 104 located between a water collection port 102b of rainwater from the building and the vertical pipe 103, a first curved pipe 105-1 located between the horizontal pipe 104 and the vertical pipe 103, a second curved pipe 105-2 located between the water collection port 102b and the horizontal pipe 104, and a piping member 106. The piping member 106 is located between the first curved pipe 105-1 and the vertical pipe 103 in such a manner that a straight pipe member 108 is connected to the first curved pipe 105-1 and the vertical pipe 103 is connected to the second socket 192 of the joint member 109. This structure can stably promote the effect of the siphon phenomenon while reducing the influence on the appearance, and can improve the drainage capacity.

[0273] In the piping system 100, the length of the vertical pipe 103 is 1.0 m or more. This structure can improve the drainage capacity.

[0274] [2. Modification example]

[0275] The embodiment of the present invention is not limited to the above-mentioned embodiment. The above-mentioned embodiment can be variously modified according to design etc. as long as the subject of the present invention can be achieved. The following lists the modified examples of the above-mentioned embodiment. The modified examples described below can be appropriately combined and applied.

[0276] It should be noted that, below, reference to reference numerals used in Embodiment 1 is only for the purpose of simplifying the description even if they are applicable to any of Embodiments 1 to 3 described above, and is not intended to exclude application to Embodiments 2 and 3.

[0277] [2.1 Modification 1]

[0278] Figure 27 to Figure 29 The following is a structural example of the siphon inducing member 5A according to the modification 1. In particular, Fig. 27 It is a side view of the siphon inducing member 5A. Fig.28 It is a top view of the siphon inducing member 5A. Fig.29 It is a cross-sectional view of the siphon inducing member 5A.

[0279] The siphon inducing member 5A can be used in the rainwater pipe system 1 , 10 instead of the siphon inducing member 5 .

[0280] like Fig. 27 As shown in FIG. 1 , the siphon inducing member 5A includes a straight tube portion 51A and a reduced diameter portion 52. Fig.28 as well as Fig.29 As shown, the siphon inducing member 5A further includes a plurality of ribs 53A.

[0281] The straight pipe portion 51A has a main body portion 51a, a flange portion 51b, and a connecting portion 51c. The flange portion 51b and the connecting portion 51c are located at both ends of the main body portion 51a in the direction of the central axis C1. The flange portion 51b faces the upstream side of the flow path 1a of the straight pipe portion 51A, and the connecting portion 51c faces the downstream side of the flow path 1a of the straight pipe portion 51A. The flange portion 51b defines an end 511 on the upstream side of the straight pipe portion 51A. In this modified example, the end 511 on the upstream side of the straight pipe portion 51A is also the end on the upstream side of the siphon inducing member 5A. The connecting portion 51c defines an end 512 on the downstream side of the straight pipe portion 51A.

[0282] In the siphon inducing member 5 of the above embodiment, the normal line of the boundary surface between the main body 51a and the connecting portion 51c coincides with the central axis C1. That is, the position of the boundary between the main body 51a and the connecting portion 51c is the same in the circumferential direction of the straight tube portion 51. In this modification, Fig. 27 As shown, the normal line N1 of the boundary surface between the main body 51a and the connecting portion 51c and the central axis C1 do not coincide but intersect. That is, the position of the boundary between the main body 51a and the connecting portion 51c is different in the circumferential direction of the straight tube portion 51A. Therefore, the inclination angle (slope) of the inner peripheral surface 513 of the connecting portion 51c varies depending on the location.

[0283] In the case of the rainwater gutter system 1, the siphon inducing member 5A is arranged so that the boundary between the main body 51a and the connecting portion 51c is located at the uppermost position ( Fig. 27 The siphon inducing member 5A is installed on the second connecting joint 7b in such a manner that the siphon inducing member 5A faces the first socket 71b side of the second connecting joint 7b (i.e., the inner peripheral side of the bent portion 73b). In other words, the siphon inducing member 5A is installed so that the boundary between the main body portion 51a and the connecting portion 51c is located at the lowest position ( Fig. 27 The connecting portion 51a is installed on the second connecting joint 7b in such a manner that the connecting portion 51c (the right side of the connecting portion 51c) faces the side of the second connecting joint 7b opposite to the first socket 71b side (i.e., the outer peripheral side of the curved portion 73b). In this case, the inclination angle of the inner peripheral surface 513 of the connecting portion 51c is smallest on the inner peripheral side of the curved portion 73b and largest on the outer peripheral side of the curved portion 73b. In addition, the length of the inner peripheral surface 510 of the main body 51a in the direction of the central axis C1 is shortest on the inner peripheral side of the curved portion 73b and longest on the outer peripheral side of the curved portion 73b. With this structure, the siphon inducing member 5A can reduce the difference in flow velocity between rainwater passing through the inner peripheral side of the curved portion 73b of the second connecting joint 7b and rainwater passing through the outer peripheral side of the curved portion 73b of the second connecting joint 7b. As a result, the speed of rainwater passing through the curved portion 73b of the second connecting joint 7b is made uniform, and the effect of inducing the siphon phenomenon can be further improved.

[0284] In the case of the rainwater pipe system 10, the inclination angle (slope) of the inner peripheral surface 513 of the connection portion 51c is different, so that the flow rate of rainwater passing through the connection joint 7 can be controlled. Therefore, when it is necessary to control the flow rate of rainwater passing through the connection joint 7, the desired flow rate can be achieved by appropriately setting the inclination angle (slope) of the inner peripheral surface 513 of the connection portion 51c of the siphon inducing member 5A. As an example, the siphon inducing member 5A can reduce Fig.29 The difference in flow velocity of rainwater passing through the connection joint 7 in the left and right directions. Thus, the velocity of rainwater passing through the connection joint 7 is made uniform, and the effect of inducing the siphon phenomenon can be further improved.

[0285] The plurality of ribs 53A are used for rectifying the flow of rainwater. That is, the plurality of ribs 53A function as rectifying plates for rectifying the flow of rainwater flowing into the straight pipe portion 51A. Fig.28 As shown, the plurality of ribs 53A are located on the inner peripheral surface 510 of the straight tube portion 51A at positions that are rotationally symmetrical with respect to the center axis C1 of the straight tube portion 51A when viewed from the direction of the center axis C1 of the straight tube portion 51A. Fig.28 In the embodiment, the number of ribs 53A is 13. The plurality of ribs 53A are arranged at equal intervals around the center axis C1 of the straight tube portion 51A when viewed from the direction of the center axis C1 of the straight tube portion 51A. Fig.29 As shown, the plurality of ribs 53A are located at the same position in the direction of the central axis C1 of the straight tube portion 51A.

[0286] Each of the plurality of ribs 53A is plate-shaped. Each of the plurality of ribs 53A has a constant distance from the center axis C1 of the straight tube portion 51A in the direction of the center axis C1 of the straight tube portion 51A. In the present modification, the plurality of ribs 53A have the same shape and size.

[0287] like Fig.29 As shown, each of the plurality of ribs 53A extends from the boundary portion between the flange portion 51b and the main body portion 51a to the downstream end 512 of the straight pipe portion 51A. That is, the upstream end 530 of each of the plurality of ribs 53A is located at the boundary portion between the flange portion 51b and the main body portion 51a. When the siphon inducing member 5A is connected to the second connection joint 7b, similarly to the siphon inducing member 5, the flange portion 51b and a portion of the main body portion 51a of the siphon inducing member 5A are located in the second connection joint 7b, but the remaining portion of the main body portion 51a of the siphon inducing member 5A and the reduced diameter portion 52 protrude outward from the second socket 72b of the second connection joint 7b (see FIG. 2 ). Figure 3). Therefore, the upstream ends 530 of the plurality of ribs 53A are located between the downstream inlet 731 along the horizontal plane from the corner portion 730 on the inner circumference of the curved portion 73b to the opening 721 of the second socket 72b. As a result, the drainage capacity of the rainwater pipe trough system 1 can be further improved. When the upstream end 530 of the rib 53A is located above the downstream inlet 731, the rib 53A often functions as a resistance component that hinders the flow of rainwater rather than a component that straightens the flow of rainwater. On the other hand, when the upstream end 530 of the rib 53A is located below the opening 721, the straightening effect brought about by the rib 53A is reduced, and sometimes it is impossible to expect an improvement in the drainage capacity of the rainwater pipe trough system 1.

[0288] As described above, the siphon inducing member 5A has a plurality of ribs 53A for rectifying flow, unlike the siphon inducing member 5. In the siphon inducing member 5 having only the reduced diameter portion 52, it is sometimes difficult to generate the siphon phenomenon, and it is difficult to improve the drainage capacity. In particular, in the rainwater pipe trough system 1, when the angle θ1 of the second connection joint 7b is close to 90°, the pressure loss generated by the second connection joint 7b during drainage is large, and in the siphon inducing member 5 having only the reduced diameter portion 52, it is sometimes difficult to generate the siphon phenomenon, and it is difficult to improve the drainage capacity. The siphon inducing member 5A has a plurality of ribs 53A for rectifying flow in addition to the reduced diameter portion 52, so that during drainage, the flow velocity can be suppressed from decreasing due to the pressure loss and maintained, and the siphon phenomenon can be easily generated. That is, the siphon inducing member 5A can continuously generate the siphon phenomenon, and the stability of the siphon phenomenon is improved, compared with the siphon inducing member 5. As a result, the drainage capacity of the rainwater pipe trough system 1 can be further improved.

[0289] The siphon inducing member 5A described above has a plurality of ribs 53A for rectifying flow on the inner peripheral surface 510 of the siphon inducing member 5A. This structure can further improve the drainage capacity of the rainwater gutter system 1.

[0290] In the rainwater pipe trough system 1 having the siphon inducing member 5A, the second connection joint 7b has: a first bell 71b having an opening 711 for receiving the lateral branch pipe 6; a second bell 72b having an opening 721 for receiving the downpipe 3; and a curved portion 73b connecting the first bell 71b and the second bell 72b. The upstream end 530 of the plurality of ribs 53A is located between the downstream inlet 731 and the opening 721 of the second bell 72b, and the downstream inlet 731 passes through the corner 730 on the inner circumference of the curved portion 73b and is along the horizontal plane. This structure can further improve the drainage capacity of the rainwater pipe trough system 1.

[0291] [2.2 Modification 2]

[0292] Figure 30 to Figure 32The following is a structural example of the siphon inducing member 5B according to the modification 2. In particular, Fig.30 It is a side view of the siphon inducing member 5B. Fig.31 It is a top view of the siphon inducing member 5B. Fig.32 It is a cross-sectional view of the siphon inducing member 5B.

[0293] The siphon inducing member 5B can be used in the rainwater pipe system 1 , 10 instead of the siphon inducing member 5 .

[0294] like Fig.30 As shown in FIG. 1 , the siphon inducing member 5B includes a straight tube portion 51B and a reduced diameter portion 52. Fig.31 as well as Fig.32 As shown, the siphon inducing member 5B further includes a plurality of ribs 53A.

[0295] The straight pipe portion 51B has a main body portion 51a, a flange portion 51b, and a connecting portion 51c. The flange portion 51b and the connecting portion 51c are located at both ends of the main body portion 51a in the direction of the central axis C1. The flange portion 51b faces the upstream side of the flow path 1a of the straight pipe portion 51B, and the connecting portion 51c faces the downstream side of the flow path 1a of the straight pipe portion 51B. The flange portion 51b defines an end 511 on the upstream side of the straight pipe portion 51B. In this modified example, the end 511 on the upstream side of the straight pipe portion 51B is also the end on the upstream side of the siphon inducing member 5B. The connecting portion 51c defines an end 512 on the downstream side of the straight pipe portion 51B.

[0296] In the siphon inducing member 5 of the above embodiment, the inner diameter and the outer diameter of the main body 51a are constant in the direction of the central axis C1. Fig.30 as well as Fig.32 As shown, the inner diameter and the outer diameter of the main body 51a decrease along the central axis C1 as it moves from the upstream side to the downstream side. Fig.30 The outer diameter D5 of the main body portion 51 a shown shows the maximum value of the outer diameter of the main body portion 51 a.

[0297] like Fig.31 As shown, the plurality of ribs 53A are located on the inner peripheral surface 510 of the straight tube portion 51B at positions that are rotationally symmetrical with respect to the center axis C1 of the straight tube portion 51B when viewed from the direction of the center axis C1 of the straight tube portion 51B. Fig.31 In the embodiment, the number of ribs 53A is 7. The plurality of ribs 53A are arranged at equal intervals around the center axis C1 of the straight tube portion 51B when viewed from the direction of the center axis C1 of the straight tube portion 51B. Fig.32 As shown, the plurality of ribs 53A are located at the same position in the direction of the central axis C1 of the straight tube portion 51B.

[0298] The siphon inducing member 5B described above has a plurality of ribs 53A for rectifying flow on the inner peripheral surface 510 of the siphon inducing member 5B. This structure can further improve the drainage capacity of the rainwater gutter system 1.

[0299] In the rainwater pipe trough system 1 having the siphon inducing member 5B, the second connection joint 7b has: a first bell 71b having an opening 711 for receiving the lateral branch pipe 6; a second bell 72b having an opening 721 for receiving the downpipe 3; and a curved portion 73b connecting the first bell 71b and the second bell 72b. The upstream end 530 of the plurality of ribs 53A is located between the downstream inlet 731 and the opening 721 of the second bell 72b, and the downstream inlet 731 passes through the corner 730 on the inner circumference of the curved portion 73b and is along the horizontal plane. This structure can further improve the drainage capacity of the rainwater pipe trough system 1.

[0300] [2.3 Modification 3]

[0301] Figure 33 to Figure 35 The following is a structural example of a siphon inducing member 5C according to a modification example 3. In particular, Fig.33 It is a side view of the siphon inducing member 5C. Fig.34 It is a top view of the siphon inducing member 5C. Fig.35 It is a cross-sectional view of the siphon inducing member 5C.

[0302] The siphon inducing member 5C can be used in the rainwater pipe system 1 , 10 instead of the siphon inducing member 5 .

[0303] like Fig.33 As shown in FIG. 5 , the siphon inducing member 5C includes a straight tube portion 51B and a reduced diameter portion 52. Fig.34 as well as Fig.35 As shown, the siphon inducing member 5C further includes a plurality of ribs 53A.

[0304] The siphon inducing member 5C is different from the siphon inducing member 5B in the number of the plurality of ribs 53A. That is, in the siphon inducing member 5C, the number of the ribs 53A is not particularly limited, and the siphon inducing member 5C may have one or more ribs 53A for rectifying.

[0305] [2.4 Modification 4]

[0306] Figure 36 to Figure 38 The following is a structural example of a siphon inducing member 5D according to a modification example 4. In particular, Fig.36 4 is a side view of the siphon inducing member 5D. Fig.37 It is a top view of the siphon inducing member 5D. Fig.38 It is a cross-sectional view of the siphon inducing member 5D.

[0307] The siphon inducing member 5D can be used in the rainwater pipe system 1 , 10 instead of the siphon inducing member 5 .

[0308] like Fig.36 As shown in FIG. 5 , the siphon inducing member 5D includes a straight tube portion 51A and a reduced diameter portion 52. Fig.37 as well as Fig.38 As shown, the siphon inducing member 5D further includes a plurality of ribs 53D.

[0309] The plurality of ribs 53D are used for rectifying the flow of rainwater. That is, the plurality of ribs 53D function as rectifying plates for rectifying the flow of rainwater flowing into the straight pipe portion 51A. Fig.37 As shown, the plurality of ribs 53D are located on the inner peripheral surface 510 of the straight tube portion 51A at positions that are rotationally symmetrical with respect to the center axis C1 of the straight tube portion 51A when viewed from the direction of the center axis C1 of the straight tube portion 51A. Fig.37 In the embodiment, the number of ribs 53D is 13. The plurality of ribs 53D are arranged at equal intervals around the center axis C1 of the straight tube portion 51A when viewed from the direction of the center axis C1 of the straight tube portion 51A. Fig.38 As shown, the plurality of ribs 53D are located at the same position in the direction of the central axis C1 of the straight tube portion 51A.

[0310] Each of the plurality of ribs 53D is plate-shaped. The distance between each of the plurality of ribs 53D and the center axis C1 of the straight tube portion 51A in the direction of the center axis C1 of the straight tube portion 51A changes. More specifically, the distance between each of the plurality of ribs 53D and the center axis C1 of the straight tube portion 51A decreases as it moves from the upstream side to the downstream side in the direction of the center axis C1 of the straight tube portion 51A. That is, when viewed from the direction of the center axis C1 of the straight tube portion 51A, the area of ​​the circle centered on the center axis C1 of the straight tube portion 51A and in contact with the plurality of ribs 53D decreases as it moves from the upstream side to the downstream side in the direction of the center axis C1 of the straight tube portion 51A. Thus, the plurality of ribs 53D can reduce the resistance to the flow of rainwater compared to the plurality of ribs 53A. Therefore, the plurality of ribs 53D can be expected to increase or maintain the flow rate of rainwater compared to the plurality of ribs 53A. In this modified example, the plurality of ribs 53D have the same shape and size.

[0311] like Fig.38 As shown, each of the plurality of ribs 53D extends from the boundary portion between the flange portion 51b and the main body portion 51a to the downstream end 512 of the straight pipe portion 51A. That is, the upstream end 530 of each of the plurality of ribs 53D is located at the boundary portion between the flange portion 51b and the main body portion 51a. Therefore, in the rainwater pipe trough system 1, the upstream end 530 of the plurality of ribs 53D is located between the downstream inlet 731 along the horizontal plane passing through the corner portion 730 on the inner circumference of the curved portion 73b to the opening 721 of the second socket 72b. As a result, the drainage capacity of the rainwater pipe trough system 1 can be further improved.

[0312] The siphon inducing member 5D described above has a plurality of ribs 53D for rectifying flow on the inner peripheral surface 510 of the siphon inducing member 5D. This structure can further improve the drainage capacity of the rainwater gutter system 1.

[0313] In the rainwater pipe trough system 1 having the siphon inducing member 5D, the second connection joint 7b has: a first bell 71b having an opening 711 for receiving the lateral branch pipe 6; a second bell 72b having an opening 721 for receiving the downpipe 3; and a curved portion 73b connecting the first bell 71b and the second bell 72b. The upstream end 530 of the plurality of ribs 53D is located between the downstream inlet 731 and the opening 721 of the second bell 72b, and the downstream inlet 731 passes through the corner 730 on the inner circumference of the curved portion 73b and is along the horizontal plane. This structure can further improve the drainage capacity of the rainwater pipe trough system 1.

[0314] It should be noted that, in the siphon inducing member 5D, the number of the ribs 53D is not particularly limited, and the siphon inducing member 5D may have one or more ribs 53D for rectifying.

[0315] [2.5 Modification 5]

[0316] Figure 39 to Figure 41 The following is a structural example of a siphon inducing member 5E according to a modification example 5. In particular, Fig.39 It is a side view of the siphon inducing member 5E. Fig.40 It is a top view of the siphon inducing member 5E. Fig.41 It is a cross-sectional view of the siphon inducing member 5E.

[0317] The siphon inducing member 5E can be used in the rainwater pipe system 1 , 10 instead of the siphon inducing member 5 .

[0318] like Fig.39 As shown in FIG. 5 , the siphon inducing member 5E includes a straight tube portion 51 and a reduced diameter portion 52. Fig.40 as well as Fig.41 As shown, the siphon inducing member 5E further includes a reduced diameter portion 54 different from the reduced diameter portion 52. Hereinafter, in order to easily distinguish the reduced diameter portions 52 and 54 from each other, the reduced diameter portion 52 may be referred to as a first reduced diameter portion 52 and the reduced diameter portion 54 may be referred to as a second reduced diameter portion 54.

[0319] like Fig.41 As shown in FIG. 5 , the second reduced diameter portion 54 is located on the side of the main body portion 51 a opposite to the first reduced diameter portion 52 . Fig.41 In the embodiment, the second reduced diameter portion 54 is located at a boundary between the flange portion 51 b and the main body portion 51 a. Fig.41The second reduced diameter portion 54 extends from the inner peripheral surface 510 of the main body portion 51a toward the central axis C1 side of the straight tube portion 51. The second reduced diameter portion 54 is in the shape of a plate with uniform thickness. The second reduced diameter portion 54 has an opening 540. The opening 540 defines the flow path cross-sectional area of ​​the second reduced diameter portion 54. Fig. 22 In the embodiment, the inner diameter D6 of the opening 540 is equal to the inner diameter D1 of the first reduced diameter portion 52. That is, the first reduced diameter portion 52 and the second reduced diameter portion 54 have the same flow path cross-sectional area. However, in the direction of the central axis C1 of the straight tube portion 51, the second reduced diameter portion 54 is shorter than the first reduced diameter portion 52.

[0320] The siphon inducing member 5E has a second diameter-reduced portion 54 in addition to the first diameter-reduced portion 52. Thus, the siphon inducing member 5E can enhance the effect of inducing the siphon phenomenon in the rainwater pipe trough system 1 or stably promote the effect of the siphon phenomenon in the rainwater pipe trough system 1. That is, the siphon inducing member 5E can achieve an improvement in drainage capacity.

[0321] It should be noted that the siphon inducing member 5E may include two or more second reduced diameter portions 54 .

[0322] [2.6 Modification 6]

[0323] Figure 42 to Figure 44 The following is a structural example of a siphon inducing member 5F according to a modification example 6. In particular, Fig.42 It is a side view of the siphon inducing member 5F. Fig.43 It is a top view of the siphon inducing member 5F. Fig.44 It is a cross-sectional view of the siphon inducing member 5F.

[0324] The siphon inducing member 5F can be used in the rainwater pipe system 1 , 10 instead of the siphon inducing member 5 .

[0325] like Figure 42 to Figure 44 As shown, the siphon inducing member 5F includes a straight tube portion 51 and a reduced diameter portion 52F.

[0326] In the direction of the center axis C1 of the straight tube portion 51, the reduced diameter portion 52F of the siphon inducing member 5F is longer than the reduced diameter portion 52 of the siphon inducing member 5. That is, in the siphon inducing member 5F, the length of the reduced diameter portion 52F (the dimension in the direction of the center axis C1 of the straight tube portion 51) is not particularly limited. The length of the reduced diameter portion 52F can be determined based on the positional relationship with the downpipe 3, in particular, the distance from the downstream end 52b of the reduced diameter portion 52F to the downstream end 3b of the downpipe 3 shown in Table 2 (see Figure 1 The range of L2) should be appropriately set.

[0327] [2.7 Modification 7]

[0328] Fig.45 as well as Fig.46 The following is a structural example of a siphon inducing member 5G according to a modification example 7. In particular, Fig.45 It is an explanatory diagram of a structural example of the siphon inducing member 5G and the second connection joint 7b. Fig.46 It is a cross-sectional view of the siphon inducing member 5G.

[0329] The siphon inducing member 5G can be used in the rainwater pipe system 1 instead of the siphon inducing member 5 .

[0330] like Fig.45 As shown, the siphon inducing member 5G includes a straight tube portion 51G, a reduced diameter portion 52, and a plurality of ribs 53D.

[0331] The straight pipe portion 51G includes a main body portion 51 a , a flange portion 51 b , and a connecting portion 51 c .

[0332] The flange portion 51b defines the maximum value (maximum outer diameter D4) of the outer dimensions of the siphon inducing member 5G. The maximum outer diameter D4 is larger than the outer diameter D5 of the main body portion 51a. The flange portion 51b is used for connection with the second socket 72b of the second connection joint 7b. The flange portion 51b is larger than the outer dimensions of the main body portion 51a and the connecting portion 51c, but is large enough to be inserted into the second socket 72b of the second connection joint 7b. Fig.45 The maximum outer diameter D4 is smaller than the inner diameter D72 of the opening 721b of the second socket 72b of the second connection joint 7b. The flange portion 51b is sized so as not to enter the curved portion 73b from the second socket 72b. The insertion degree of the siphon inducing member 5G into the second connection joint 7b can be adjusted by the size and position of the flange portion 51b.

[0333] In the siphon inducing member 5G, the flange portion 51b is not located at the upstream end of the main body portion 51a in the direction of the central axis C1, but is located on the outer surface of the main body portion 51a. In the siphon inducing member 5G, the upstream end of the main body portion 51a defines the upstream end 511 of the straight tube portion 51G. Here, the upstream end 511 of the straight tube portion 51G is also the upstream end of the siphon inducing member 5G.

[0334] And, if Fig.46 As shown, the flange portion 51b is located on the outer surface of the main body portion 51a a predetermined distance below the upstream end 511 of the straight pipe portion 51G in such a way that the upstream end 511 of the straight pipe portion 51G is located at the downstream inlet 731 when the siphon inducing member 5G is connected to the second connecting joint 7b.

[0335] Here, each of the plurality of ribs 53D extends from the upstream end 511 of the straight pipe portion 51G to the downstream end 512 of the straight pipe portion 51G. That is, the upstream end 530 of each of the plurality of ribs 53D is located at the upstream end 511 of the straight pipe portion 51G. Furthermore, when the siphon inducing member 5G is connected to the second connection joint 7b, the upstream end 511 of the straight pipe portion 51G is located at the downstream inlet 731, and therefore, the upstream end 530 of each of the plurality of ribs 53D is also located at the downstream inlet 731. Thus, the drainage capacity of the rainwater gutter system 1 can be further improved.

[0336] It should be noted that the main body portion 51 a and the connecting portion 51 c of the straight pipe portion 51G have the same structure as the main body portion 51 a and the connecting portion 51 c of the straight pipe portion 51A.

[0337] In the rainwater gutter system 1 including the siphon inducing member 5G, the upstream end 530 of the plurality of ribs 53D is located at the downstream inlet 731. This structure can further improve the drainage capacity of the rainwater gutter system 1.

[0338] [2.8 Other Modifications]

[0339] In a modified example, the shape and size of part or all of the siphon inducing components 5, 5A to 5G may be different from those in embodiments 1, 2 and modifications 1 to 7. For example, unlike embodiments 1 and 2, in the siphon inducing component 5, the shape of the straight tube portion 51 and the reduced diameter portion 52 in a plane orthogonal to the central axis C1 of the straight tube portion 51 may not be a circular shape, but a polygonal shape. In embodiments 1 and 2, in the cross section of the straight tube portion 51 in the plane including the central axis C1 of the straight tube portion 51, the inner peripheral surface 510 is a straight line, but in the modified example, it may be a curved line or a broken line. The siphon inducing components 5, 5A to 5G may be different from those in embodiments 1 and 2 and modifications 1 to 7. Fig.12 It can be used in place of the siphon inducing member 107 in the piping system 100.

[0340] In a modified example, the shape and size of a part or all of the siphon inducing member 107 may be different. For example, unlike the third embodiment, in the siphon inducing member 107, the shapes of the reduced diameter portion 171 and the expanded diameter portion 172 in the plane orthogonal to the central axis C10 may not be circular, but polygonal. In the third embodiment, in the cross section in the plane including the central axis C10, the first inner circumferential surface 170a of the reduced diameter portion 171 and the second inner circumferential surface 170b of the expanded diameter portion 172 are curved, but in the modified example, they may be straight or broken line-shaped.

[0341] In a modified example, the straight tube portion 51 and the reduced diameter portion 52 of the siphon inducing member 5 may also be formed discontinuously and integrally. The straight tube portion 51 and the reduced diameter portion 52 may be independent. The straight tube portion 51 and the reduced diameter portion 52 may be mechanically combined by assembly or the like. The straight tube portion 51 and the reduced diameter portion 52 may also be made of different materials. This point is also the same in the siphon inducing members 5A to 5G. In addition, this point is also the same in the straight tube portion 51 and the second reduced diameter portion 54 of the siphon inducing member 5E.

[0342] In a modified example, the siphon inducing member 5A may not include the rib 53A. Similarly, the siphon inducing member 5G may not include the rib 53D.

[0343] In a modified example, the material of the siphon inducing member 5, 5A to 5G, 107 does not need to be rigid polyvinyl chloride. The material of the siphon inducing member 5, 5A to 5G, 107 can be determined according to the necessary conditions required by the rainwater pipe trough system 1, 10 or the piping system 100, for example, it can be a synthetic resin such as polyethylene, or it can be a metal instead of a synthetic resin.

[0344] In a modified example, the material of the downpipe 3, siphon inducing components 5, 5A to 5G, the lateral branch pipe 6, the first and second connecting joints 7a, 7b, the auxiliary downpipe 8, the connecting joint 7, the auxiliary downpipe 60, the vertical pipe 103, the horizontal pipe 104, the bent pipes 105-1, 105-2, the siphon inducing component 107, the straight pipe component 108 and the joint component 109 may be metal instead of synthetic resin.

[0345] In a modified example, the discharge pipe 4, 110 may be a discharge pipe of a structure generally considered not to be helpful for the generation of the siphon phenomenon. In a modified example, the discharge pipe 4, 110 is not necessary.

[0346] In a modified example, the first connection joint 7a and the second connection joint 7b and the first curved tube 105-1 and the second curved tube 105-2 are not limited to 90° elbows, and may be 45° elbows (45L), for example.

[0347] In a modified example, the second connection joint 7 b may not have the mark 74 .

[0348] In a modified example, the auxiliary downpipes 8, 60 are not necessary.

[0349] In a modified example, the siphon inducing members 5, 5A to 5G and other siphon inducing members and the first and second connecting joints 7a, 7b and the connecting joint 7 and other connecting joints may not be independent members but may be formed integrally.

[0350] In a modified example, the reduced diameter portion 171 and the expanded diameter portion 172 of the siphon inducing member 107 may also be continuously and integrally formed.

[0351] In a modified example, the reduced diameter portion 171 and the expanded diameter portion 172 of the siphon inducing member 107 may have different shapes. For example, the length H1 of the reduced diameter portion 171 and the length H2 of the expanded diameter portion 172 may also be different.

[0352] In a modified example, the shape, number, and arrangement of the protrusions 173 are not particularly limited. The siphon inducing member 107 may not include the protrusions 173 .

[0353] In a modified example, the shape, number and arrangement of the first through-holes 174a are not particularly limited. The siphon inducing member 107 may not include the first through-holes 174a. The number of the second through-holes 174b is not particularly limited. The siphon inducing member 107 may not include the second through-holes 174b.

[0354] In a modified example, the shape, number and arrangement of the first concave-convex parts 1751a to 1751d and the second concave-convex parts 1752a to 1752d are not particularly limited. The siphon inducing member 107 may not include the first concave-convex parts 1751a to 1751d and the second concave-convex parts 1752a to 1752d.

[0355] In a modified example, the siphon inducing member 107 may not be a separate member from the straight pipe member 108 but may be formed integrally. The straight pipe member 108 may not be a separate member from the joint member 109 but may be formed integrally.

[0356] In a modified example, the connection portion 101 may include a mark 74 similar to the connection portions 9 and 90. The position of the mark 74 is not particularly limited, but the mark 74 may be located on the straight pipe member 108.

[0357] [3. Plan]

[0358] As is apparent from the embodiment and the modified examples, the present invention includes the following aspects.

[0359] [Solution 1]

[0360] A rainwater pipe trough system is a rainwater pipe trough system constituting a flow path of rainwater, wherein:

[0361] The rainwater pipe trough system has:

[0362] Downspouts;

[0363] a connecting portion connecting the downspout of the eave to the end on the upstream side of the downspout; and

[0364] Siphon inducing component,

[0365] The cross-sectional area of ​​the eaves is 11000 mm 2 above,

[0366] The inner diameter of the downpipe is greater than 67.0 mm.

[0367] The wall thickness of the downpipe is 2.2 mm or more.

[0368] The siphon inducing member is cylindrical and has a reduced diameter portion, wherein the reduced diameter portion has a flow path cross-sectional area smaller than a flow path cross-sectional area of ​​the connecting portion.

[0369] The siphon inducing member is located immediately below the connecting portion in the flow path.

[0370] [Solution 2]

[0371] A stormwater pipe trough system according to Scheme 1, wherein:

[0372] A ratio of an inner diameter of the reduced diameter portion to an inner diameter of the downpipe is greater than or equal to 0.50 and less than or equal to 0.70.

[0373] [Solution 3]

[0374] A stormwater trough system according to Option 1 or 2, wherein:

[0375] In the siphon inducing member, a length from an upstream end of the siphon inducing member to an upstream end of the reduced diameter portion is equal to or greater than 1 time an inner diameter of the reduced diameter portion.

[0376] [Solution 4]

[0377] According to any one of the rainwater pipe trough systems in Schemes 1 to 3,

[0378] A distance from the downstream end of the reduced diameter portion to the downstream end of the downpipe is 1.0 m or more.

[0379] [Solution 5]

[0380] According to any one of the stormwater pipe trough systems in Schemes 1 to 4,

[0381] The siphon inducing member has one or more ribs for flow rectification on an inner peripheral surface of the siphon inducing member.

[0382] [Solution 6]

[0383] According to any one of the stormwater pipe trough systems in Schemes 1 to 5,

[0384] The connecting portion is directly connected to the upstream end of the downpipe.

[0385] The siphon inducing member is shielded by the connecting portion and the downpipe.

[0386] [Solution 7]

[0387] A stormwater trough system according to Scheme 6, wherein:

[0388] The connecting portion has a mark indicating the presence of the siphon inducing member on an outer surface of the connecting portion.

[0389] [Scheme 8]

[0390] According to any one of the stormwater pipe trough systems in Schemes 1 to 7,

[0391] The siphon inducing member has a first end and a second end facing the upstream side and the downstream side of the rainwater pipe system, respectively, and is in a cylindrical shape having an inner peripheral surface that defines a flow path cross-sectional area.

[0392] The siphon inducing member further comprises an expanded diameter portion.

[0393] The flow path cross-sectional area of ​​the reduced diameter portion decreases from the first end toward the second end.

[0394] A flow path cross-sectional area of ​​the expanded diameter portion increases from the reduced diameter portion toward the second end.

[0395] [Solution 9]

[0396] A stormwater trough system according to Scheme 8, wherein:

[0397] The siphon inducing member includes a protrusion located on the inner peripheral surface,

[0398] The protrusion has a first front end located at the reduced diameter portion and a second front end located at the expanded diameter portion,

[0399] A straight line connecting the first front end and the second front end is inclined with respect to a central axis of the siphon inducing member.

[0400] [Scheme 10]

[0401] A stormwater trough system according to Scheme 9, wherein:

[0402] In the reduced diameter portion, the width of the protrusion increases as it moves from the first end toward the second end.

[0403] In the expanded diameter portion, a width of the protrusion becomes narrower as it goes from the first end to the second end.

[0404] [Scheme 11]

[0405] A storm sewer system according to Option 9 or 10, wherein:

[0406] In the reduced diameter portion, the height of the protrusion increases as it goes from the first end to the second end.

[0407] In the expanded diameter portion, the height of the protrusion decreases from the first end toward the second end.

[0408] [Scheme 12]

[0409] According to any one of the stormwater pipe trough systems in Schemes 1 to 11,

[0410] The connecting portion comprises:

[0411] A horizontal branch pipe, which is located between the eaves and the downpipe;

[0412] A first connecting joint, which connects the upstream end of the lateral branch pipe to the downspout; and

[0413] a second connecting joint, which connects the downstream end of the lateral branch pipe to the upstream end of the downpipe,

[0414] The flow path cross-sectional area of ​​the reduced diameter portion is smaller than the flow path cross-sectional area of ​​the second connection joint,

[0415] The siphon inducing member is located immediately below the second connection joint in the flow path.

[0416] [Scheme 13]

[0417] According to any one of the stormwater pipe trough systems in Schemes 1 to 11,

[0418] The connection portion includes a connection joint for connecting the upstream end of the downpipe to the downspout in a vertical direction.

[0419] The cross-sectional area of ​​the flow path of the reduced diameter portion is smaller than the cross-sectional area of ​​the flow path of the connecting joint.

[0420] The siphon inducing member is located immediately below the connection joint in the flow path.

[0421] [Scheme 14]

[0422] A siphon inducing component constitutes a part of a rainwater pipe trough system, wherein the rainwater pipe trough system constitutes a flow path of rainwater, wherein:

[0423] The rainwater pipe trough system has:

[0424] downspouts; and

[0425] A connecting portion that connects the downspout of the eaves to the upstream end of the downspout,

[0426] The cross-sectional area of ​​the eaves is 11000 mm 2 above,

[0427] The inner diameter of the downpipe is greater than 67.0 mm.

[0428] The wall thickness of the downpipe is 2.2 mm or more.

[0429] The siphon inducing member is in a cylindrical shape that can be arranged immediately below the connecting portion in the flow path, and has a reduced diameter portion having a flow path cross-sectional area smaller than that of the connecting portion.

[0430] [Scheme 15]

[0431] A siphon inducing member constitutes a part of a piping system, wherein the piping system constitutes a flow path, wherein:

[0432] The siphon inducing member has a first end and a second end facing the upstream side and the downstream side of the piping system, respectively, and is in a cylindrical shape having an inner peripheral surface defining a flow path cross-sectional area.

[0433] The siphon inducing component comprises:

[0434] a reduced diameter portion, wherein the flow path cross-sectional area decreases as it moves from the first end toward the second end; and

[0435] The expanded diameter portion has the flow path cross-sectional area increasing as it goes from the reduced diameter portion toward the second end.

[0436] Means 2 to 13 are arbitrary elements. The above-mentioned means 2 to 13 can also be combined with means 14 or 15 as appropriate.

[0437] [Scheme 21]

[0438] A rainwater pipe trough system is a rainwater pipe trough system constituting a flow path of rainwater, wherein:

[0439] The rainwater pipe trough system has:

[0440] A downpipe connected to the downspout of the eaves;

[0441] A horizontal branch pipe, which is located between the eaves and the downpipe;

[0442] A first connecting joint, which connects the upstream end of the horizontal branch pipe to the downspout;

[0443] a second connection joint connecting the downstream end of the lateral branch pipe to the upstream end of the downpipe; and

[0444] Siphon inducing component,

[0445] The cross-sectional area of ​​the eaves is 11000 mm 2 above,

[0446] The inner diameter of the downpipe is greater than 67.0 mm.

[0447] The wall thickness of the downpipe is 2.2 mm or more.

[0448] The siphon inducing member is cylindrical and has a reduced diameter portion, wherein the reduced diameter portion has a flow path cross-sectional area smaller than a flow path cross-sectional area of ​​the second connection joint.

[0449] The siphon inducing member is located immediately below the second connection joint in the flow path.

[0450] [Scheme 22]

[0451] A stormwater trough system according to Scheme 21, wherein:

[0452] The second connection joint is directly connected to the upstream end of the downpipe.

[0453] The siphon inducing member is shielded by the second connection joint and the downpipe.

[0454] [Scheme 23]

[0455] A storm sewer system according to Option 21 or 22, wherein:

[0456] The second connection joint has a mark indicating the presence of the siphon inducing member on an outer surface of the second connection joint.

[0457] [Scheme 24]

[0458] A stormwater trough system according to Scheme 23, wherein:

[0459] The marking can be visually confirmed under visible light.

[0460] [Scheme 25]

[0461] According to any one of the stormwater pipe trough systems in Schemes 21 to 24,

[0462] The siphon inducing member has one or more ribs for flow rectification on an inner peripheral surface of the siphon inducing member.

[0463] [Scheme 26]

[0464] A stormwater trough system according to Scheme 25, wherein:

[0465] The second connection joint has:

[0466] A first socket having an opening for receiving the lateral branch pipe;

[0467] A second socket having an opening for receiving the downpipe; and

[0468] a bent portion connecting the first socket and the second socket,

[0469] The upstream end of the one or more ribs is located between the opening from the downstream inlet to the second bellmouth, and the downstream inlet passes through the corner of the inner peripheral side of the curved portion and is along the horizontal plane.

[0470] [Scheme 27]

[0471] A stormwater trough system according to Scheme 26, wherein:

[0472] An upstream end of the one or more ribs is located at the downstream inlet.

[0473] [Scheme 28]

[0474] According to any one of the stormwater pipe trough systems in Schemes 21 to 27,

[0475] A ratio of an inner diameter of the reduced diameter portion to an inner diameter of the downpipe is greater than or equal to 0.50 and less than or equal to 0.70.

[0476] [Scheme 29]

[0477] According to any one of the stormwater pipe trough systems in Schemes 21 to 28,

[0478] In the siphon inducing member, a length from an upstream end of the siphon inducing member to an upstream end of the reduced diameter portion is equal to or greater than 1 time an inner diameter of the reduced diameter portion.

[0479] [Scheme 30]

[0480] According to any one of the stormwater pipe trough systems in Schemes 21 to 29,

[0481] A distance from the downstream end of the reduced diameter portion to the downstream end of the downpipe is 1.0 m or more.

[0482] [Scheme 31]

[0483] A siphon inducing component, constituting a part of a rainwater pipe trough system, wherein the rainwater pipe trough system constitutes a flow path of rainwater,

[0484] The rainwater pipe trough system has:

[0485] A downpipe connected to the downspout of the eaves;

[0486] A horizontal branch pipe, which is located between the eaves and the downpipe;

[0487] A first connecting joint, which connects the upstream end of the lateral branch pipe to the downspout; and

[0488] a second connecting joint, which connects the downstream end of the lateral branch pipe to the upstream end of the downpipe,

[0489] The cross-sectional area of ​​the eaves is 11000 mm 2 above,

[0490] The inner diameter of the downpipe is greater than 67.0 mm.

[0491] The wall thickness of the downpipe is 2.2 mm or more.

[0492] The siphon inducing member is in a cylindrical shape that can be arranged immediately below the second connection joint in the flow path, and has a reduced diameter portion having a flow path cross-sectional area smaller than a flow path cross-sectional area of ​​the second connection joint.

[0493] [Scheme 32]

[0494] A rainwater pipe trough system is a rainwater pipe trough system constituting a flow path of rainwater, wherein:

[0495] The rainwater pipe trough system has:

[0496] A downpipe connected to the downspout of the eaves;

[0497] A horizontal branch pipe, which is located between the eaves and the downpipe;

[0498] A first connecting joint, which connects the upstream end of the horizontal branch pipe to the downspout;

[0499] a second connection joint connecting the downstream end of the lateral branch pipe to the upstream end of the downpipe; and

[0500] Siphon inducing component,

[0501] The siphon inducing member is cylindrical and has a reduced diameter portion, wherein the reduced diameter portion has a flow path cross-sectional area smaller than a flow path cross-sectional area of ​​the second connection joint.

[0502] The siphon inducing member is located immediately below the second connection joint in the flow path.

[0503] Means 22 to 30 are arbitrary elements. The above-mentioned means 22 to 30 can also be combined with the means 31 or 32 as appropriate.

[0504] [Scheme 41]

[0505] A rainwater pipe trough system is a rainwater pipe trough system constituting a flow path of rainwater, wherein:

[0506] The rainwater pipe trough system has:

[0507] A downpipe connected to the downspout of the eaves; and

[0508] A connecting joint that connects the upstream end of the downpipe to the downspout in a vertical direction; and

[0509] Siphon inducing component,

[0510] The cross-sectional area of ​​the eaves is 11000 mm 2 above,

[0511] The inner diameter of the downpipe is greater than 67.0 mm.

[0512] The wall thickness of the downpipe is 2.2 mm or more.

[0513] The siphon inducing member is cylindrical and has a reduced diameter portion, wherein the reduced diameter portion has a flow path cross-sectional area smaller than a flow path cross-sectional area of ​​the connecting joint.

[0514] The siphon inducing member is located immediately below the connection joint in the flow path.

[0515] [Scheme 42]

[0516] A stormwater trough system according to Scheme 41, wherein:

[0517] The connection joint is directly connected to the upstream end of the downpipe.

[0518] The siphon inducing member is concealed by the connecting joint and the downpipe.

[0519] [Scheme 43]

[0520] A storm sewer system according to plan 41 or 42, wherein:

[0521] The connection joint has a mark indicating the presence of the siphon inducing member on an outer surface of the connection joint.

[0522] [Scheme 44]

[0523] A stormwater trough system according to Scheme 43, wherein:

[0524] The marking can be visually confirmed under visible light.

[0525] [Scheme 45]

[0526] According to any one of the stormwater pipe trough systems in Schemes 41 to 44,

[0527] The siphon inducing member has one or more ribs for flow rectification on an inner peripheral surface of the siphon inducing member.

[0528] [Scheme 46]

[0529] According to any one of the stormwater pipe trough systems in Schemes 41 to 45,

[0530] A ratio of an inner diameter of the reduced diameter portion to an inner diameter of the downpipe is greater than or equal to 0.50 and less than or equal to 0.70.

[0531] [Scheme 47]

[0532] According to any one of the stormwater pipe trough systems in Schemes 41 to 46,

[0533] In the siphon inducing member, a length from an upstream end of the siphon inducing member to an upstream end of the reduced diameter portion is equal to or greater than 1 time an inner diameter of the reduced diameter portion.

[0534] [Scheme 48]

[0535] According to any one of the stormwater pipe trough systems in Schemes 41 to 47,

[0536] A distance from the downstream end of the reduced diameter portion to the downstream end of the downpipe is 1.0 m or more.

[0537] [Scheme 49]

[0538] A siphon inducing component constitutes a part of a rainwater pipe trough system, wherein the rainwater pipe trough system constitutes a flow path of rainwater, wherein:

[0539] The rainwater pipe trough system has:

[0540] A downpipe connected to the downspout of the eaves; and

[0541] a connecting joint that connects the upstream end of the downpipe to the downspout,

[0542] The cross-sectional area of ​​the eaves is 11000 mm 2 above,

[0543] The inner diameter of the downpipe is greater than 67.0 mm.

[0544] The wall thickness of the downpipe is 2.2 mm or more.

[0545] The siphon inducing member is in a cylindrical shape that can be arranged immediately below the connection joint in the flow path, and has a reduced diameter portion having a flow path cross-sectional area that is smaller than a flow path cross-sectional area of ​​the connection joint.

[0546] [Scheme 50]

[0547] A rainwater pipe trough system is a rainwater pipe trough system constituting a flow path of rainwater, wherein:

[0548] The rainwater pipe trough system has:

[0549] A downpipe connected to the downspout of the eaves;

[0550] A connecting joint that connects the upstream end of the downpipe to the downspout in a vertical direction; and

[0551] Siphon inducing component,

[0552] The siphon inducing member is cylindrical and has a reduced diameter portion, wherein the reduced diameter portion has a flow path cross-sectional area smaller than a flow path cross-sectional area of ​​the connecting joint.

[0553] The siphon inducing member is located immediately below the connection joint in the flow path.

[0554] The above-mentioned means 42 to 48 are arbitrary elements. The above-mentioned means 42 to 48 can be combined with the means 49 or 50 as appropriate.

[0555] [Scheme 61]

[0556] A siphon inducing member constitutes a part of a piping system, wherein the piping system constitutes a flow path, wherein:

[0557] The siphon inducing member has a first end and a second end facing the upstream side and the downstream side of the piping system, respectively, and is in a cylindrical shape having an inner peripheral surface defining a flow path cross-sectional area.

[0558] The siphon inducing component comprises:

[0559] a reduced diameter portion, wherein the flow path cross-sectional area decreases as it moves from the first end toward the second end; and

[0560] The expanded diameter portion has the flow path cross-sectional area increasing as it goes from the reduced diameter portion toward the second end.

[0561] [Scheme 62]

[0562] A siphon inducing member according to claim 61, wherein:

[0563] When the outer diameter of the siphon inducing member is represented by P, and the inner diameter of the siphon inducing member where the flow path cross-sectional area becomes the smallest is represented by P1, 0.50≤P1 / P≤0.75.

[0564] [Scheme 63]

[0565] A siphon inducing member according to claim 61 or 62, wherein:

[0566] The siphon inducing member includes a protrusion located on the inner peripheral surface,

[0567] The protrusion has a first front end located at the reduced diameter portion and a second front end located at the expanded diameter portion,

[0568] A straight line connecting the first front end and the second front end is inclined with respect to a central axis of the siphon inducing member.

[0569] [Scheme 64]

[0570] A siphon inducing member according to claim 63, wherein:

[0571] In the reduced diameter portion, the width of the protrusion increases as it moves from the first end toward the second end.

[0572] In the expanded diameter portion, a width of the protrusion becomes narrower as it goes from the first end to the second end.

[0573] [Scheme 65]

[0574] A siphon inducing member according to claim 63 or 64, wherein:

[0575] In the reduced diameter portion, the height of the protrusion increases as it goes from the first end to the second end.

[0576] In the expanded diameter portion, the height of the protrusion decreases from the first end toward the second end.

[0577] [Scheme 66]

[0578] According to any one of schemes 63 to 65, the siphon inducing component,

[0579] The siphon inducing member includes a plurality of protrusions.

[0580] The plurality of protrusions are arranged at equal intervals around the central axis when viewed from the direction of the central axis of the siphon inducing member.

[0581] [Scheme 67]

[0582] According to any one of schemes 61 to 66, the siphon inducing component,

[0583] The siphon inducing member has a maximum outer diameter at the first end and the second end.

[0584] [Scheme 68]

[0585] According to any one of schemes 61 to 67, the siphon inducing component,

[0586] The length of the reduced diameter portion is equal to the length of the expanded diameter portion.

[0587] [Scheme 69]

[0588] According to any one of schemes 61 to 68, the siphon inducing component,

[0589] The reduced diameter portion and the expanded diameter portion are independent components.

[0590] The reduced diameter portion has a first concave-convex portion at a third end opposite to the first end.

[0591] The enlarged diameter portion has a second concave-convex portion mechanically coupled to the first concave-convex portion at a fourth end opposite to the second end.

[0592] The reduced diameter portion and the expanded diameter portion are coupled to each other by mechanically coupling the first concavo-convex portion and the second concavo-convex portion.

[0593] [Scheme 70]

[0594] According to any one of schemes 61 to 69, the siphon inducing component,

[0595] The reduced diameter portion and the expanded diameter portion are configured as components having the same shape and size.

[0596] [Scheme 71]

[0597] According to any one of schemes 61 to 70, the siphon inducing component,

[0598] When the length of the siphon inducing member is denoted as H, and the inner diameter of the siphon inducing member at which the flow path cross-sectional area becomes the smallest is denoted as P1, H≥P1.

[0599] [Scheme 72]

[0600] A piping component, wherein:

[0601] The piping member comprises:

[0602] Any siphon inducing component of schemes 61 to 71;

[0603] a straight pipe member, inside which the siphon inducing member is disposed; and

[0604] The joint member has a first socket facing the upstream side of the piping system and connected to the straight pipe member, and a second socket facing the downstream side of the piping system and capable of connecting to a piping element having the same outer diameter as the straight pipe member.

[0605] [Scheme 73]

[0606] A piping component according to claim 72, wherein:

[0607] The distance between the upstream end of the straight pipe member and the first socket is greater than or equal to 50 mm and less than or equal to 1000 mm.

[0608] [Scheme 74]

[0609] A piping system, wherein:

[0610] The piping system comprises:

[0611] Standpipes, which are fixed to the walls of buildings;

[0612] a horizontal pipe located between the water collection port for rainwater from the building and the vertical pipe;

[0613] A first curved tube, located between the horizontal tube and the vertical tube;

[0614] A second curved pipe, located between the water collection port and the cross pipe; and

[0615] The piping components of Plan 72 or 73,

[0616] The pipe member is located between the first bent pipe and the vertical pipe in such a manner that the straight pipe member is connected to the first bent pipe and the vertical pipe is connected to the second socket of the joint member.

[0617] [Scheme 75]

[0618] A piping system according to claim 74, wherein:

[0619] The length of the vertical pipe is more than 1.0 m.

[0620] Schemes 62 to 71, 73 and 75 are optional elements and are not essential.

[0621] Industrial Applicability

[0622] The present invention can be applied to a rainwater trough system and a siphon inducing member. Specifically, the present invention can be applied to a rainwater trough system that utilizes the siphon phenomenon in the discharge of rainwater and a siphon inducing member assembled in the rainwater trough system to induce the siphon phenomenon in the rainwater trough system.

[0623] The present invention can be applied to a siphon inducing member, a piping member, and a piping system. Specifically, the present invention can be applied to a siphon inducing member for inducing a siphon phenomenon, a piping member including the siphon inducing member, and a piping system including the piping member.

[0624] Description of Reference Numerals

[0625] 1, 10: Rainwater pipe trough system, 1a: Flow path, 2: Eaves, 2d: Downspout, 3: Downspout, 3a: End on the upstream side, 3b: End on the downstream side, 5, 5A to 5G: Siphon inducing member, 511: End on the upstream side, 52, 52F: Reduced diameter portion, 52a: End on the upstream side, 52b: End on the downstream side, 53A, 53D: Rib, 530: End on the upstream side, 6: Transverse branch pipe, 6a: End on the upstream side, 6b: End on the downstream side, 7: Connecting joint, 7a: First connecting joint, 7b: Second connecting joint, 71b: First socket, 711: Opening, 72b: Second socket, 721: Opening, 73b: Bend, 730: Corner, 731: Downstream inflow port, 74: Mark, 100: Piping system, 1 00a: flow path, 101: connecting portion, 102b: water collection port, 103: vertical pipe, 104: horizontal pipe, 105-1: first bent pipe, 105-2: second bent pipe, 106: piping member, 107: siphon inducing member, 107a: first end, 107b: second end, 170: inner circumferential surface, 171: reduced diameter portion, 172: expanded diameter portion, 173: protrusion, 1731: first front end, 1732: second front end, 1751a~1751d: first concave-convex portion, 1752a~1752d: second concave-convex portion, 108: straight pipe member, 109: joint member, 191: first socket, 192: second socket, C10: center axis, C20: straight line (a straight line connecting the first front end and the second front end).

Claims

1. A rainwater pipe trough system is a rainwater pipe trough system constituting a flow path of rainwater, wherein: The rainwater pipe trough system has: Downspouts; A connecting portion connecting the downspout of the eave to the upstream end of the downspout; and Siphon inducing component, The cross-sectional area of ​​the eaves is 11000mm 2 above, The inner diameter of the downpipe is 67.0 mm or more. The wall thickness of the downpipe is 2.2 mm or more. The siphon inducing member is cylindrical and has a reduced diameter portion, wherein the reduced diameter portion has a flow path cross-sectional area smaller than a flow path cross-sectional area of ​​the connecting portion. The siphon inducing member is located immediately below the connecting portion in the flow path.

2. The rainwater pipe trough system according to claim 1, wherein: A ratio of an inner diameter of the reduced diameter portion to an inner diameter of the downpipe is greater than or equal to 0.50 and less than or equal to 0.

70.

3. The rainwater pipe trough system according to claim 1, wherein: In the siphon inducing member, a length from an upstream end of the siphon inducing member to an upstream end of the reduced diameter portion is equal to or greater than 1 time an inner diameter of the reduced diameter portion.

4. The rainwater trough system according to claim 1, wherein: A distance from the downstream end of the reduced diameter portion to the downstream end of the downpipe is 1.0 m or more.

5. The rainwater pipe trough system according to claim 1, wherein: The siphon inducing member has one or more ribs for flow rectification on an inner peripheral surface of the siphon inducing member.

6. The rainwater trough system according to claim 1, wherein: The connecting portion is directly connected to the upstream end of the downpipe. The siphon inducing member is shielded by the connecting portion and the downpipe.

7. The rainwater trough system according to claim 6, wherein: The connecting portion has a mark indicating the presence of the siphon inducing member on an outer surface of the connecting portion.

8. The rainwater trough system according to claim 1, wherein: The siphon inducing member has a first end and a second end facing the upstream side and the downstream side of the rainwater pipe system, respectively, and is in a cylindrical shape having an inner peripheral surface that defines a flow path cross-sectional area. The siphon inducing member further comprises an expanded diameter portion. The flow path cross-sectional area of ​​the reduced diameter portion decreases from the first end toward the second end. A flow path cross-sectional area of ​​the expanded diameter portion increases from the reduced diameter portion toward the second end.

9. The rainwater trough system according to claim 8, wherein: The siphon inducing member includes a protrusion located on the inner peripheral surface, The protrusion has a first front end located at the reduced diameter portion and a second front end located at the expanded diameter portion, A straight line connecting the first front end and the second front end is inclined with respect to a central axis of the siphon inducing member.

10. The storm sewer system according to claim 9, wherein: In the reduced diameter portion, the width of the protrusion increases as it moves from the first end toward the second end. In the expanded diameter portion, a width of the protrusion becomes narrower as it goes from the first end to the second end.

11. The storm sewer system according to claim 9, wherein: In the reduced diameter portion, the height of the protrusion increases as it moves from the first end to the second end. In the expanded diameter portion, the height of the protrusion decreases as it goes from the first end to the second end.

12. The storm sewer system according to claim 1, wherein: The connecting portion comprises: A horizontal branch pipe, which is located between the eaves and the downpipe; A first connecting joint, which connects the upstream end of the lateral branch pipe to the downspout; and a second connecting joint, which connects the downstream end of the lateral branch pipe to the upstream end of the downpipe, The flow path cross-sectional area of ​​the reduced diameter portion is smaller than the flow path cross-sectional area of ​​the second connection joint, The siphon inducing member is located immediately below the second connection joint in the flow path.

13. The storm sewer system according to claim 1, wherein: The connection portion includes a connection joint for connecting the upstream end of the downpipe to the downspout in a vertical direction. The cross-sectional area of ​​the flow path of the reduced diameter portion is smaller than the cross-sectional area of ​​the flow path of the connecting joint. The siphon inducing member is located immediately below the connection joint in the flow path.

14. A siphon inducing member, constituting a part of a rainwater pipe trough system, wherein the rainwater pipe trough system constitutes a flow path for rainwater, wherein: The rainwater pipe trough system has: downspouts; and A connecting portion that connects the downspout of the eaves to the upstream end of the downspout, The cross-sectional area of ​​the eaves is 11000mm 2 above, The inner diameter of the downpipe is 67.0 mm or more. The wall thickness of the downpipe is 2.2 mm or more. The siphon inducing member is in a cylindrical shape that can be arranged immediately below the connecting portion in the flow path, and has a reduced diameter portion having a flow path cross-sectional area smaller than that of the connecting portion.

15. A siphon inducing member constituting a part of a piping system, wherein the piping system constitutes a flow path, wherein: The siphon inducing member has a first end and a second end facing the upstream side and the downstream side of the piping system, respectively, and is in a cylindrical shape having an inner peripheral surface defining a flow path cross-sectional area. The siphon inducing component comprises: a reduced diameter portion, wherein the flow path cross-sectional area decreases as it moves from the first end toward the second end; and The expanded diameter portion has the flow path cross-sectional area increasing as it goes from the reduced diameter portion toward the second end.

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