Piping components and rain gutter systems

Abstract

To provide a piping member, and a rain gutter system capable of stably promoting effect caused by the siphon phenomenon.SOLUTION: A piping members 5 configures a part of a down pipe 3 of a rain gutter system 1 using the siphon phenomenon on drainage of rain water. The piping member 5 is provided with: a straight pipe part 51 forming a part of a passage 30 of the down pipe 3; a diffusion part 52 connected on the straight pipe part 51 and placed in the passage 30. The diffusion part 52 comprises a small opening 521 of which a passage area is smaller than that of the down pipe 51 and a guide surface 522 guiding rain water passing through the opening 521 to a direction separating it apart from a center axis C1 of the down pipe 51.SELECTED DRAWING: Figure 1

Description

Technical Field

[0006]

[0001] The present disclosure relates to a piping member and a rain gutter system.

Background Art

[0002] Patent Document 1 discloses a rain gutter system. The rain gutter system disclosed in Patent Document 1 includes an eaves gutter, a downspout, a connection joint that is disposed downstream of the eaves gutter and is continuous with the upper end of the downspout, and a siphon joint provided in the downspout and having a reduced diameter portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0008] Aspects of this disclosure can stably promote the action due to the siphon phenomenon. [Brief explanation of the drawing]

[0009] [Figure 1] Schematic diagram of an example configuration of a rain gutter system equipped with piping members according to Embodiment 1. [Figure 2] Perspective view of an example of the piping component configuration in Figure 1. [Figure 3] Cross-sectional view of the piping member in Figure 2. [Figure 4] Diagram illustrating the operation of piping components (Figure 2) [Figure 5] Figure 1 is an explanatory diagram of the rain gutter system used for drainage. [Figure 6] Schematic diagram of an example configuration of a rain gutter system equipped with piping members according to Embodiment 2. [Figure 7] Figure 6 is an explanatory diagram of the rain gutter system for drainage. [Figure 8] Cross-sectional view of the configuration example of the piping member in Modification Example 1 [Figure 9] Cross-sectional view of the configuration example of the piping member in modified example 2. [Figure 10] Cross-sectional view of the configuration example of the piping member in modified example 3. [Figure 11] Cross-sectional view of the configuration example of the piping member in modified example 4. [Figure 12] Cross-sectional view of the configuration example of the piping member in modified example 5. [Figure 13] Cross-sectional view of the configuration example of the piping member in modified example 6. [Figure 14] Cross-sectional view of the configuration example of the piping member in modified example 7. [Figure 15] Perspective view of the configuration example of the piping components in modified example 8. [Figure 16] Cross-sectional view of the piping member in Figure 15. [Figure 17] Cross-sectional view of the configuration example of the piping member in modified example 9. [Figure 18] Cross-sectional view of the configuration example of the pipe member of Modification Example 10 [Figure 19] Schematic diagram of the configuration example of the rain gutter system including the pipe member of Modification Example 11 [Figure 20] Cross-sectional view of the configuration example of the pipe member of Modification Example 12 [Embodiments for Carrying Out the Invention]

[0010] Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, a more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art. Note that the inventors provide the accompanying drawings and the following description so that those skilled in the art can fully understand the present disclosure, and do not intend to limit the subject matter described in the claims thereby.

[0011] The positional relationships such as up and down, left and right are based on the positional relationships shown in the drawings unless otherwise specified. Each of the drawings described in the following embodiments is a schematic diagram, and the ratios of the sizes and thicknesses of each component in each drawing do not necessarily reflect the actual dimensional ratios. Also, the dimensional ratios of each element are not limited to the ratios shown in the drawings.

[0012] [1. Embodiment] [1.1 Embodiment 1] [1.1.1 Configuration] Figure 1 is a schematic diagram of an example configuration of a rain gutter system 1 according to Embodiment 1. The rain gutter system 1 receives rainwater from the roof 11a of a building 11 and directs it to a drain section 21 on the ground 20. The rainwater collected in the drain section 21 flows out of the drain section 21 through an underground pipe 22 into a rainwater pipe. The building 11 is, for example, a building of non-residential facilities such as shops, offices, factories, office buildings, schools, welfare facilities or hospitals, and a building of residential facilities such as a detached house, an apartment building, or individual dwelling units in a detached house or an apartment building. Non-residential facilities also include theaters, cinemas, public halls, amusement parks, complexes, department stores, hotels, inns, kindergartens, libraries, museums, art galleries, underground shopping malls, train stations and airports.

[0013] The rain gutter system 1 in Figure 1 comprises a gutter 2, a downpipe 3, and a drain 4.

[0014] The gutter 2 receives rainwater from the roof 11a of the building 11. The gutter 2 is installed beneath the roof 11a of the building 11. The gutter 2 is long and barrel-shaped. The gutter 2 in Figure 1 has a bottom wall 2a. There is a drain outlet 2b in the bottom wall 2a.

[0015] Drain 4 is positioned at the outlet 2b of the gutter 2. Drain 4 reduces the generation of vortices and air entrainment at the outlet 2b. Drain 4 may contribute to the generation of a siphon effect. Drain 4 may have a well-known configuration.

[0016] The downpipe 3 is installed to drain rainwater from the outlet 2b. The downpipe 3 has a channel 30 for vertically draining rainwater from the outlet 2b. In the downpipe 3 shown in Figure 1, no branch pipes from gutters other than the one in the gutter 2 are connected to the channel 30. In other words, the downpipe 3 is configured so that rainwater from outlets other than the one in the gutter 2b does not flow into the channel 30.

[0017] The downpipe 3 has an upstream end 3a and a downstream end 3b. The upstream end 3a is the end of the downpipe 3 that is connected to the outlet 2b (the upper end in Figure 1). In Figure 1, the downpipe 3 is directly connected to the outlet 2b. That is, rainwater falls vertically from the outlet 2b into the flow path 30 of the downpipe 3 and flows into the manhole 21. The downstream end 3b is the end of the downpipe 3 that is inserted into the manhole 21 (the lower end in Figure 1). In Figure 1, a drain pipe cover 34 is positioned to prevent rainwater from flowing into the manhole 21 through the gap between the downpipe 3 and the manhole 21.

[0018] In Figure 1, the downpipe 3 is fixed to the wall surface 11b of the building 11 by bracing brackets 33a, 33b, and 33c. The distance from the ground 20 to the top end of the downpipe 3 [mm], the distance from the top end of the downpipe 3 to the uppermost bracing bracket 33a [mm], and the distance from the ground 20 to the lowermost bracing bracket 33c [mm] are generally between 200 mm and 300 mm. The pitch [mm] between bracing brackets 33a, 33b, and 33c is generally between 800 mm and 1200 mm, and in certain cases, it is 1000 mm or less. The distance between the downpipe 3 and the wall surface 11b is generally between 30 mm and 100 mm.

[0019] The downpipe 3 in Figure 1 comprises a first vertical pipe 31, a second vertical pipe 32, and a piping member 5.

[0020] The first vertical pipe 31 constitutes a part of the flow path 30 of the downpipe 3. In this embodiment, the internal space enclosed by the inner surface 31a of the first vertical pipe 31 becomes a part of the flow path 30 of the downpipe 3. In this embodiment, the first vertical pipe 31 is the upstream part of the downpipe 3. The first vertical pipe 31 is a straight pipe. The cross-section perpendicular to the pipe axis of the first vertical pipe 31 is circular. The material of the first vertical pipe 31 is rigid polyvinyl chloride. The dimensions of the first vertical pipe 31, for example, the outer shape and thickness, may be set in accordance with the standard for rigid polyvinyl chloride pipes (general) of JIS K 6741 "Rigid Polyvinyl Chloride Pipe". The first vertical pipe 31 is fixed to the wall surface 11b of the building 11 so that the direction of the pipe axis of the first vertical pipe 31 coincides with the vertical direction. The upper end of the first vertical pipe 31 is the upstream end 3a of the downpipe 3.

[0021] The second vertical pipe 32 constitutes a part of the flow path 30 of the downpipe 3. In this embodiment, the internal space enclosed by the inner surface 32a of the second vertical pipe 32 becomes a part of the flow path 30 of the downpipe 3. The internal space of the second vertical pipe 32 becomes a part of the flow path 30 of the downpipe 3. The second vertical pipe 32 is the downstream part of the downpipe 3. The second vertical pipe 32 is a straight pipe. The cross-section perpendicular to the pipe axis of the second vertical pipe 32 is circular. The material of the second vertical pipe 32 is rigid polyvinyl chloride. The dimensions of the second vertical pipe 32, for example, the outer shape and thickness, may be set in accordance with the standard for rigid polyvinyl chloride pipes (general) of JIS K 6741 "Rigid Polyvinyl Chloride Pipe". The second vertical pipe 32 is fixed to the wall surface 11b of the building 11 so that the direction of the pipe axis of the second vertical pipe 32 coincides with the vertical direction. The lower end of the second vertical pipe 32 is the downstream end 3b of the downpipe 3. End 3b is also the part of the downpipe 3 that is open to the atmosphere.

[0022] In the downpipe 3 shown in Figure 1, the diameter (inner and outer diameter) of the first vertical pipe 31 is equal to the diameter (inner and outer diameter) of the second vertical pipe 32. In other words, pipe materials corresponding to the same nominal diameter can be used for both the first vertical pipe 31 and the second vertical pipe 32.

[0023] The piping member 5 constitutes part of the downpipe 3 of the rain gutter system 1, which utilizes the siphon effect for rainwater drainage. The piping member 5 is provided in the rain gutter system 1 to stably promote the effect of the siphon effect. In the downpipe 3 shown in Figure 1, the piping member 5 is located between the first vertical pipe 31 and the second vertical pipe 32. The piping member 5 in Figure 1 may be a socket connecting pipes. The position of the piping member 5 in the downpipe 3 is set appropriately considering the degree to which the siphon effect occurs during rainwater drainage.

[0024] The piping member 5 in Figure 1 comprises a straight pipe section 51 and a diffusion section 52. The piping member 5 will be further described below with reference to Figures 2 and 3. Figure 2 is a perspective view of an example configuration of the piping member 5. Figure 3 is a cross-sectional view of the piping member 5.

[0025] The straight pipe section 51 defines at least a portion of the flow path 30 of the downpipe 3. In this embodiment, the internal space of the straight pipe section 51, surrounded by the inner surface 510 of the straight pipe section 51, becomes part of the flow path 30 of the downpipe 3. As is clear from Figure 2, the cross-section perpendicular to the central axis C1 of the straight pipe section 51 is circular. The central axis C1 of the straight pipe section 51 is also the pipe axis of the straight pipe section 51. The material of the straight pipe section 51 is rigid polyvinyl chloride. The dimensions of the straight pipe section 51, for example, the outer shape and thickness, may be set in accordance with the standard for rigid polyvinyl chloride pipes (general) of JIS K 6741 "Rigid Polyvinyl Chloride Pipe". The straight pipe section 51 is arranged such that the direction of the central axis C1 of the straight pipe section 51 coincides with the vertical direction.

[0026] As shown in Figure 3, the straight pipe section 51 has a first end 51a and a second end 51b, and an intermediate section 51c between the first end 51a and the second end 51b, in the direction of the central axis C1.

[0027] The first end portion 51a is directed towards the upstream side of the downpipe 3. As shown in Figure 3, the first end portion 51a is connected to the lower end of the first vertical pipe 31. In this embodiment, the outer dimensions of the first end portion 51a are smaller than those of the intermediate portion 51c, and it is sized to be inserted into the first vertical pipe 31. The length of the first end portion 51a in the direction of the central axis C1 may be set appropriately to ensure a stable connection between the piping member 5 and the first vertical pipe 31. As shown in Figure 3, the second end portion 51b is connected to the upper end of the second vertical pipe 32. In this embodiment, the outer dimensions of the second end portion 51b are smaller than those of the intermediate portion 51c, and it is sized to be inserted into the second vertical pipe 32. In this embodiment, the outer dimensions of the second end portion 51b are equal to those of the first end portion 51a. The length of the second end portion 51b in the direction of the central axis C1 may be set appropriately to ensure a stable connection between the piping member 5 and the second vertical pipe 32. In Figure 3, the internal dimensions of the first end 51a, the second end 51b, and the intermediate section 51c are equal.

[0028] As shown in Figures 2 and 3, the straight pipe section 51 has an opening 511 at its first end 51a. In this embodiment, the opening 511 defines the inlet of the piping member 5. Therefore, in the downpipe 3, rainwater from the first vertical pipe 31 enters the internal space of the straight pipe section 51 through the opening 511, which is the inlet of the straight pipe section 51.

[0029] As shown in Figure 2, the straight pipe section 51 has a mark 51d. The mark 51d indicates the orientation for installing the piping member 5. The mark 51d in Figure 2 is an arrow, and when installing the piping member 5, the piping member 5 should be installed so that the arrow indicated by the mark 51d points upward. The mark 51d in Figure 2 is located on the outer surface of the first end 51a. When the piping member 5 is connected to the first vertical pipe 31, the mark 51d is hidden by the first vertical pipe 31. The mark 51d may be a letter, figure, symbol, three-dimensional shape, or color, or a combination thereof, that is recognizable by human perception.

[0030] The diffusion section 52 is connected to the straight pipe section 51 and positioned in the flow path 30. In this embodiment, as shown in Figure 3, the diffusion section 52 is located at the second end 51b of the straight pipe section 51. In this embodiment, the diffusion section 52 is formed integrally with the straight pipe section 51 and is therefore connected to the straight pipe section 51. The material of the diffusion section 52 is rigid polyvinyl chloride, the same as that of the straight pipe section 51.

[0031] As shown in Figures 2 and 3, the diffusion section 52 comprises a partition section 53 and a guide section 54.

[0032] The partition wall 53 extends from the inner surface 510 of the straight pipe section 51 toward the central axis C1 of the straight pipe section 51. The partition wall 53 is a plate-like structure with a uniform thickness. The partition wall 53 has an opening 521. As a result, the opening 521 is located inside the straight pipe section 51. In other words, the diffusion section 52 is connected to the straight pipe section 51 such that the opening 521 is located inside the straight pipe section 51.

[0033] In this embodiment, the opening 521 is located in the center of the partition wall 53. Viewed from the direction of the central axis C1 of the straight pipe section 51, the partition wall 53 is annular. The flow area of ​​the opening 521 is smaller than that of the straight pipe section 51. In this embodiment, in a plane perpendicular to the central axis C1 of the straight pipe section 51, both the opening 521 and the internal space of the straight pipe section 51 are circular. In this embodiment, the inner diameter D2 of the opening 521 is smaller than the inner diameter D1 of the straight pipe section 51. As shown in Figure 2, in this embodiment, the center O1 of the opening 521 lies on the central axis C1 of the straight pipe section 51. As shown in Figure 3, in this embodiment, the edge of the opening 521 is rounded (R-shaped).

[0034] The guide portion 54 protrudes from the edge of the opening 521 of the partition wall portion 53 toward the downstream side of the downpipe 3, for example, toward the second end 51b of the straight pipe portion 51 from the first end 51a. The guide portion 54 surrounds the entire circumference of the opening 521. In this embodiment, the guide portion 54 is hollow and frustum-shaped. A frustum is a shape obtained by removing a similarly scaled-down cone that shares a vertex with the cone. In this embodiment, the guide portion 54 is hollow and frustum-shaped. The outer and inner circumferential shapes of the guide portion 54 in the plane perpendicular to the central axis C1 of the straight pipe portion 51 are circular. The outer and inner circumferential shapes of the guide portion 54 in the plane perpendicular to the central axis C1 of the straight pipe portion 51 increase toward the second end 51b of the straight pipe portion 51.

[0035] In this embodiment, the inner circumferential surface of the guide portion 54 functions as a guide surface 522 for rainwater passing through the opening 521. The guide surface 522 faces inward towards the straight pipe portion 51. "Facing inward towards the straight pipe portion 51" means that the guide surface 522 faces the central axis C1 of the straight pipe portion 51. The guide surface 522 guides the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe portion 51. In this embodiment, the guide surface 522 moves further away from the central axis C1 of the straight pipe portion 51 as it moves downstream from the opening 521 towards the downpipe 3. In this embodiment, the inclination of the guide surface 522 is constant. That is, the increment of the distance between the guide surface 522 and the central axis C1 in the plane perpendicular to the central axis C1 of the straight pipe portion 51, relative to the distance from the opening 521, is constant.

[0036] The diffusion section 52 has an opening 523 on the opposite side of the opening 521 in the guide section 54. In this embodiment, the opening 523 defines the outlet of the piping member 5. Therefore, in the downpipe 3, rainwater from the piping member 5 enters the second vertical pipe 32 through the opening 523, which is the outlet of the piping member 5. In this embodiment, the inner diameter D3 of the opening 523 is smaller than the inner diameter D1 of the straight pipe section 51 and larger than the inner diameter D2 of the opening 521.

[0037] Next, the operation of the piping component 5 will be explained. Figure 4 is an explanatory diagram of the operation of the piping component 5. In Figure 4, rainwater W from the outlet 2b is attempting to move through the downpipe 3.

[0038] As described above, the piping member 5 is located between the first vertical pipe 31 and the second vertical pipe 32 of the downpipe 3. The piping member 5 includes a diffusion section 52 which is positioned within the flow path 30 of the downpipe 3. The diffusion section 52 has an opening 521 and a guide surface 522.

[0039] The opening 521 has a smaller flow path area than the straight pipe section 51. A reduction in flow path area can cause an increase in the flow velocity of rainwater W. Therefore, the diffusion section 52 increases the flow velocity of rainwater W at the opening 521 and directs it towards the guide surface 522. The reduction in flow path area at the opening 521 can cause an increase in pressure loss. As a result, rainwater W tends to accumulate upstream of the diffusion section 52 in the downpipe 3.

[0040] The guide surface 522 directs the rainwater W passing through the opening 521 away from the central axis C1 of the straight pipe section 51. Therefore, the diffusion section 52 diffuses the rainwater W that has passed through the opening 521 by the guide surface 522. The rainwater W diffused by the diffusion section 52 hits the inner surface of the downpipe 3. In Figure 4, the rainwater W diffused by the diffusion section 52 hits the inner surface 32a of the second vertical pipe 32 of the downpipe 3. The rainwater W hitting the inner surface of the downpipe 3 can cause an increase in pipeline pressure loss. An increase in pipeline pressure loss promotes a decrease in the flow velocity of the rainwater W, which can be a cause of rainwater W stagnation. As a result, a predetermined area downstream of the diffusion section 52 in the downpipe 3 may become full of water. In Figure 4, the downpipe 3 is full of water up to a predetermined position LP below the diffusion section 52. In other words, the diffusion section 52 can intentionally retain rainwater W by utilizing the friction on the inner surface of the downpipe 3. In particular, the opening 521 increases the flow velocity of rainwater W, which promotes an increase in pipe pressure loss. In this embodiment, the term "full water state" is not used in a strict sense and includes a state that is filled with water to an extent that can be considered equivalent to a full water state (a state close to a full water state).

[0041] The piping member 5 has a diffusion section 52, which allows for the intentional creation of a waterlogged area in the downpipe 3 of the rain gutter system 1. Figure 5 is an explanatory diagram of drainage by the rain gutter system 1. As shown in Figure 5, the piping member 5 can fill the area in the downpipe 3 between the outlet 2b position HP and a predetermined position LP with water.

[0042] One factor contributing to the siphon effect is the difference in potential energy between the upper and lower ends of the water surface as viewed from the vertical. The larger the difference in potential energy, the greater the increase in flow velocity due to the siphon effect, which is thought to increase the flow rate. In the case of Figure 5, the longer the vertical length of the area in the downpipe 3 that is filled with water, that is, the longer the distance H1 between the position HP of the outlet 2b and the predetermined position LP in the vertical direction, the greater the negative pressure at the outlet 2b, and the greater the suction force due to the siphon effect can be. As a result, the piping member 5 can stably promote the effect of the siphon effect.

[0043] In the rain gutter system 1 shown in Figure 1, the downpipe 3 is directly connected to the outlet 2b, so rainwater from the outlet 2b falls freely within the flow path 30 of the downpipe 3. However, the piping member 5 has a diffusion section 52, which allows the velocity of the rainwater falling within the flow path 30 of the downpipe 3 to be controlled. This makes it possible to satisfy the conditions for the siphon effect to occur in the downpipe 3. Because the diffusion section 52 diffuses the rainwater, it is possible to stably create a full-water state downstream of the diffusion section 52, thereby stabilizing the effect of the siphon effect. In particular, by providing the diffusion section 52, it is not necessary to reduce the diameter of the downpipe 3, and the drainage performance of the downpipe 3 itself is not significantly reduced.

[0044] The position of the piping member 5 in the downpipe 3 can be appropriately set according to the pipe diameter of the downpipe 3, the amount of rainwater passing through the downpipe 3, the installation environment of the rain gutter system 1, and various other conditions. For example, the position of the piping member 5 in the downpipe 3 may be set so as to obtain a desired difference in potential energy, taking into account the amount of rainwater expected at the installation site of the rain gutter system 1. For example, the position of the piping member 5 in the downpipe 3 may be set so that the distance H1 is a value that obtains a desired difference in potential energy.

[0045] [1.1.2 Effects, etc.] The piping member 5 described above constitutes a part of the downpipe 3 of the rain gutter system 10 that utilizes the siphon effect for rainwater drainage. The piping member 5 comprises a straight pipe section 51 that defines at least a part of the flow path 30 of the downpipe 3, and a diffusion section 52 that is connected to the straight pipe section 51 and positioned in the flow path 30. The diffusion section 52 has an opening 521 with a flow path area smaller than that of the straight pipe section 51, and a guide surface 522 that guides rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. This configuration can stably promote the effect of the siphon effect.

[0046] In the piping member 5, the guide surface 522 moves further away from the central axis C1 of the straight pipe section 51 as it moves downstream from the opening 521 towards the downpipe 3. This configuration makes it easier to guide rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51, thereby further stably promoting the effect of the siphon phenomenon.

[0047] In the piping member 5, the guide surface 522 faces inward towards the straight pipe section 51. This configuration makes it easier to guide rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51, thereby further stably promoting the siphon effect.

[0048] In the piping member 5, the length of the guide surface 522 in the direction of the central axis C1 of the straight pipe section 51 is set so that a predetermined area downstream of the diffusion section 52 in the downpipe 3 is filled with water. This configuration can stably promote the effect of the siphon phenomenon.

[0049] In the piping member 5, the edge of the opening 521 is rounded (R-shaped). This configuration reduces losses at the edge of the opening 521.

[0050] In the piping member 5, the center O1 of the opening 521 lies on the central axis C1 of the straight pipe section 51. This configuration allows for stable promotion of the siphon effect.

[0051] The rain gutter system 1 described above includes a downpipe 3 having a piping member 5 and connected to a rainwater outlet 2b from the building 11, and a drain 4 located at the outlet 2b. This configuration can stably promote the action due to the siphon effect.

[0052] In the rain gutter system 1, the downpipe 3 is directly connected to the outlet 2b. This configuration can stably promote the action caused by the siphon phenomenon.

[0053] [1.2 Embodiment 2] [1.2.1 Structure] Figure 6 is a schematic diagram of an example configuration of the rain gutter system 10 according to Embodiment 2. The rain gutter system 10 receives rainwater from the roof 11a of the building 110 and directs it to a drain section 21 on the ground 20. The rainwater collected in the drain section 21 flows out of the drain section 21 through the buried pipe 22 into the rainwater pipe. The building 110, like building 11, is a building of non-residential facilities such as shops, offices, factories, office buildings, schools, welfare facilities or hospitals, and residential facilities such as detached houses, apartment buildings, or individual dwelling units in detached houses or apartment buildings. Non-residential facilities also include theaters, cinemas, public halls, amusement parks, complexes, department stores, hotels, inns, kindergartens, libraries, museums, art galleries, underground shopping malls, train stations and airports.

[0054] Building 110 has a longer eaves than building 11 described in Embodiment 1. In building 110, if the downpipe 3 is directly connected to the drain outlet 2b, the distance between the downpipe 3 and the wall surface 11b of building 110 becomes large, and the construction standards for the downpipe 3 are no longer met. The rain gutter system 10 of this embodiment has a structure suitable for building 110 with long eaves. The rain gutter system 10 in Figure 6 comprises an eaves gutter 2, a downpipe 3, a drain 4, a connecting downpipe 6, a first elbow 7a, a second elbow 7b, and an auxiliary downpipe 8.

[0055] The eaves gutter 2, downpipe 3, and drain 4 of the rain gutter system 10 in Figure 6 are the same as the eaves gutter 2, downpipe 3, and drain 4 of the rain gutter system 1 in Figure 1.

[0056] In the rain gutter system 10, the downpipe 3 is not directly connected to the outlet 2b. In the rain gutter system 10, the downpipe 3 is connected to the outlet 2b via the connecting pipe 6, the first elbow 7a, and the second elbow 7b.

[0057] The downpipe 6 is the section that directs rainwater from the building 110 from the outlet 2b to the downpipe 3. The downpipe 6 is located between the rainwater outlet 2b and the downpipe 3. The downpipe 6 is a straight pipe. The cross-section of the downpipe 6 perpendicular to its axis is circular. The material of the downpipe 6 is rigid polyvinyl chloride. In Figure 6, the downpipe 6 is fixed so that the direction of its axis is inclined with respect to the vertical direction.

[0058] The downpipe 6 has an upstream end 6a and a downstream end 6b. The upstream end 6a is the end of the downpipe 6 that connects to the outlet 2b (the upper end in Figure 6). The downstream end 6b is the end of the downpipe 6 that connects to the downpipe 3 (the lower end in Figure 6). The downpipe 6 is cylindrical. The material of the downpipe 6 is rigid polyvinyl chloride. The dimensions of the downpipe 6, for example, the outer diameter and thickness, may be set in accordance with the standard for rigid polyvinyl chloride pipes (general) of JIS K 6741 "Rigid Polyvinyl Chloride Pipes".

[0059] The first elbow 7a connects the upstream end 6a of the downpipe 6 to the outlet 2b. The first elbow 7a is not necessarily a member that directly connects the upstream end 6a of the downpipe 6 to the outlet 2b, but may be a member that indirectly connects the upstream end 6a of the downpipe 6 to the outlet 2b via another member. The material of the first elbow 7a is, for example, rigid polyvinyl chloride. The first elbow 7a has sockets 71a and 72a for connecting pipe materials such as the downpipe 3 and the downpipe 6 to the first elbow 7a. The angle between the central axes of the sockets 71a and 72a is, for example, 91.17° as specified in JIS K 6739 "Rigid polyvinyl chloride pipe fittings for drainage". The inner and outer corners of the first elbow 7a in the plane containing the pipe axis of the first elbow 7a are approximately right angles, not R-shaped.

[0060] The second elbow 7b connects the downstream end 6b of the downpipe 6 to the upstream end 3a of the downpipe 3. The second elbow 7b is not necessarily a member that directly connects the downstream end 6b of the downpipe 6 to the upstream end 3a of the downpipe 3, but may be a member that indirectly connects the downstream end 6b of the downpipe 6 to the upstream end 3a of the downpipe 3 via another member. The material of the second elbow 7b is, for example, rigid polyvinyl chloride. The second elbow 7b has sockets 71b and 72b for connecting pipe materials such as the downpipe 3 and the downpipe 6 to the second elbow 7b. The angle between the central axes of the sockets 71b and 72b is, for example, 91.17° as specified in JIS K 6739 "Rigid polyvinyl chloride pipe fittings for drainage". The inner and outer corners of the second elbow 7b in the plane containing the pipe axis of the second elbow 7b are approximately right angles, not R-shaped.

[0061] The dimensions of the first elbow 7a and the second elbow 7b may be set in accordance with, for example, the JIS K 6739 standard for rigid polyvinyl chloride pipe fittings for drainage. At least one of the first elbow 7a and the second elbow 7b may be a 90° bend elbow as defined in JIS K 6739.

[0062] The auxiliary downpipe 8 is the section that allows rainwater from the building 110 to flow vertically from the outlet 2b to the first elbow 7a. The auxiliary downpipe 8 is located between the outlet 2b and the first elbow 7a. The auxiliary downpipe 8 is a straight pipe. The cross-section of the auxiliary downpipe 8 perpendicular to its pipe axis is circular. The material of the auxiliary downpipe 8 is rigid polyvinyl chloride. The dimensions of the auxiliary downpipe 8, for example, its outer shape and thickness, may be set in accordance with the standard for rigid polyvinyl chloride pipes (general) of JIS K 6741 "Rigid Polyvinyl Chloride Pipe". In Figure 6, the auxiliary downpipe 8 is positioned between the outlet 2b and the first elbow 7a so that the direction of the pipe axis of the auxiliary downpipe 8 coincides with the vertical direction.

[0063] 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 that is connected to the outlet 2b (the upper end in Figure 6). The downstream end 8b is the end of the auxiliary downpipe 8 that is connected to the first elbow 7a (the lower end in Figure 6).

[0064] In the rain gutter system 10 shown in Figure 6, the downpipe 3 comprises a first vertical pipe 31, a second vertical pipe 32, and a piping member 5. The piping member 5 comprises a straight pipe section 51 and a diffusion section 52, similar to Embodiment 1. The presence of the diffusion section 52 in the piping member 5 makes it possible to intentionally create a region in the downpipe 3 of the rain gutter system 10 that is filled with water.

[0065] In the rain gutter system 10 shown in Figure 6, a gap is likely to occur at the location indicated by A1 in the second elbow 7b. In other words, it is difficult for the second elbow 7b to become completely filled with water. However, the piping member 5 has an opening 521 with a smaller flow path area than the straight pipe section 51. The reduction in the flow path area at the opening 521 can cause an increase in pressure loss. As a result, rainwater W is more likely to accumulate upstream of the diffusion section 52 in the downpipe 3. The presence of the piping member 5 in the downpipe 3 can reduce the occurrence of a gap at the location indicated by A1 in the second elbow 7b.

[0066] Figure 7 is an explanatory diagram of drainage by the rain gutter system 10. In Figure 7, HP is the position of the upper end of the portion extending downward at the second elbow 7b. When the water level rises above position HP, rainwater will also accumulate in the downspout 6. The piping member 5 can fill the area between position HP and the predetermined position LP with water.

[0067] One factor contributing to the siphon effect is the difference in potential energy between the upper and lower ends of the water surface as viewed from the vertical. The larger the difference in potential energy, the greater the increase in flow velocity due to the siphon effect, which is thought to increase the flow rate. In the case of Figure 7, the longer the vertical length of the area filled with water in the downpipe 3 and the second elbow 7b, that is, the longer the distance H1 between the vertical position HP and the predetermined position LP, the greater the suction force due to the siphon effect can be increased. As a result, the piping member 5 can stably promote the effect of the siphon effect.

[0068] The position of the piping member 5 in the downpipe 3 can be appropriately set according to the pipe diameter of the downpipe 3, the amount of rainwater passing through the downpipe 3, the installation environment of the rain gutter system 1, and various other conditions. For example, the position of the piping member 5 in the downpipe 3 may be set so as to obtain a desired difference in potential energy, taking into account the amount of rainwater expected at the installation site of the rain gutter system 1. For example, the position of the piping member 5 in the downpipe 3 may be set so that the distance H1 is a value that obtains a desired difference in potential energy.

[0069] [1.2.2 Effects, etc.] The piping member 5 described above constitutes a part of the downpipe 3 of the rain gutter system 10 that utilizes the siphon effect for rainwater drainage. The piping member 5 comprises a straight pipe section 51 that defines at least a part of the flow path 30 of the downpipe 3, and a diffusion section 52 that is connected to the straight pipe section 51 and positioned in the flow path 30. The diffusion section 52 has an opening 521 with a flow path area smaller than that of the straight pipe section 51, and a guide surface 522 that guides rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. This configuration can stably promote the effect of the siphon effect.

[0070] In the piping member 5, the guide surface 522 moves further away from the central axis C1 of the straight pipe section 51 as it moves downstream from the opening 521 towards the downpipe 3. This configuration makes it easier to guide rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51, thereby further stably promoting the effect of the siphon phenomenon.

[0071] In the piping member 5, the guide surface 522 faces inward towards the straight pipe section 51. This configuration makes it easier to guide rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51, thereby further stably promoting the siphon effect.

[0072] In the piping member 5, the length of the guide surface 522 in the direction of the central axis C1 of the straight pipe section 51 is set so that a predetermined area downstream of the diffusion section 52 in the downpipe 3 is filled with water. This configuration can stably promote the effect of the siphon phenomenon.

[0073] In the piping member 5, the edge of the opening 521 is rounded (R-shaped). This configuration reduces losses at the edge of the opening 521.

[0074] In the piping member 5, the center O1 of the opening 521 lies on the central axis C1 of the straight pipe section 51. This configuration allows for stable promotion of the siphon effect.

[0075] The rain gutter system 10 described above includes a downpipe 3 having a piping member 5 and connected to a rainwater outlet 2b from the building 110, and a drain 4 located at the outlet 2b. This configuration can stably promote the action due to the siphon phenomenon.

[0076] The rain gutter system 10 further comprises a connecting pipe 6 located between the downspout 2b and the downpipe 3, a first elbow 7a connecting the upstream end 6a of the connecting pipe 6 to the downspout 2b, and a second elbow 7b connecting the downstream end 6b of the connecting pipe 6 to the upstream end 3a of the downpipe 3. This configuration can stably promote the action due to the siphon phenomenon.

[0077] [2. Variant] The embodiments of this disclosure are not limited to those described above. The embodiments can be modified in various ways depending on the design, etc., as long as the objectives of this disclosure can be achieved. The following lists some modifications of the embodiments. The modifications described below can be combined and applied as appropriate.

[0078] [2.1 Variation 1] Figure 8 is a cross-sectional view of an example configuration of the piping member 5A of modified example 1. The piping member 5A in Figure 8 comprises a straight pipe section 51 and a diffusion section 52A. The diffusion section 52A has a partition wall section 53A and a guide section 54.

[0079] The partition wall 53A extends from the inner surface 510 of the straight pipe section 51 toward the central axis C1 of the straight pipe section 51. The partition wall 53A has an opening 521. In this modified example, the opening 521 is located in the center of the partition wall 53A. Viewed from the direction of the central axis C1 of the straight pipe section 51, the partition wall 53A is annular. The dimensions of the partition wall 53A in the direction of the central axis C1 of the straight pipe section 51 decrease as it moves from the inner surface 510 toward the central axis C1 of the straight pipe section 51. In Figure 8, the surface of the partition wall 53A on the side of the first end 51a of the straight pipe section 51 is a tapered surface 524 inclined with respect to the central axis C1 of the straight pipe section 51. That is, the tapered surface 524 extends from the inner surface 510 of the straight pipe section 51 toward the opening 521 in a direction that intersects the central axis C1 of the straight pipe section 51 without being perpendicular to it. In Figure 8, the surface of the second end 51b of the straight pipe section 51 in the partition wall section 53A is a plane perpendicular to the central axis C1 of the straight pipe section 51.

[0080] Thus, in the piping member 5A of Figure 8, the diffusion section 52A further has a tapered surface 524 that extends from the inner surface 510 of the straight pipe section 51 toward the opening 521 in a direction that intersects but is not perpendicular to the central axis C1 of the straight pipe section 51. The tapered surface 524 can reduce the pressure loss due to the opening 521 of the diffusion section 52A. If the pressure loss due to the opening 521 is too large in the piping member 5 of Figure 3, it is possible to reduce the pressure loss to a desired level by providing a tapered surface 524 as in the piping member 5A of Figure 8. In other words, the pressure loss due to the opening 521 of the diffusion section 52A can be adjusted by appropriately setting the angle of the tapered surface 524 with respect to the central axis C1 and the shape of the tapered surface 524.

[0081] In the diffusion section 52A shown in Figure 8, the guide surface 522 directs the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. Therefore, the diffusion section 52A diffuses the rainwater that has passed through the opening 521 by the guide surface 522. The rainwater diffused by the diffusion section 52A hits the inner surface of the downpipe 3. In Figure 8, the rainwater diffused by the diffusion section 52A hits the inner surface 32a of the second downpipe 32. Rainwater hitting the inner surface of the downpipe 3 can cause an increase in pipeline pressure loss.

[0082] The piping member 5A described above constitutes a part of the downpipe of a rain gutter system that utilizes the siphon effect for rainwater drainage. The piping member 5A comprises a straight pipe section 51 that defines at least a part of the flow path of the downpipe, and a diffusion section 52A that is connected to the straight pipe section 51 and positioned in the flow path. The diffusion section 52A has an opening 521 with a flow path area smaller than that of the straight pipe section 51, and a guide surface 522 that guides rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. This configuration can stably promote the effect of the siphon effect.

[0083] In the piping member 5A, the diffusion section 52A further has a tapered surface 524 that extends from the inner surface 510 of the straight pipe section 51 toward the opening 521 in a direction that intersects but is not perpendicular to the central axis C1 of the straight pipe section 51. This configuration can reduce pressure loss due to the opening 521.

[0084] Piping member 5A can be applied in place of piping member 5 to the rain gutter system 1 in Figure 1 or the rain gutter system 10 in Figure 6.

[0085] [2.2 Variation 2] Figure 9 is a cross-sectional view of an example configuration of the piping member 5B of modified example 2. The piping member 5B in Figure 9 comprises a straight pipe section 51 and a diffusion section 52B. The diffusion section 52B has a partition wall section 53 and a guide section 54, similar to the diffusion section 52, but its position relative to the straight pipe section 51 is different from that of the diffusion section 52.

[0086] In Figure 9, the diffusion section 52B is connected to the straight pipe section 51 and positioned in the flow path 30. In this modified example, as shown in Figure 9, the diffusion section 52B is located in the intermediate section 51c of the straight pipe section 51. In this modified example, the diffusion section 52B is formed integrally with the straight pipe section 51 and is therefore connected to the straight pipe section 51.

[0087] In the piping member 5B shown in Figure 9, the straight pipe section 51 has an opening 511 at the first end 51a and an opening 512 at the second end 51b. In this modified example, the opening 511 defines the inlet of the piping member 5B. In this modified example, the opening 512 of the straight pipe section 51, rather than the opening 523 of the diffusion section 52B, defines the outlet of the piping member 5B.

[0088] In the diffusion section 52B shown in Figure 9, the guide surface 522 directs the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. Therefore, the diffusion section 52B diffuses the rainwater that has passed through the opening 521 by the guide surface 522. The rainwater diffused by the diffusion section 52B hits the inner surface of the downpipe 3. In Figure 9, the rainwater diffused by the diffusion section 52B hits the inner surface 510 of the straight pipe section 51 downstream of the diffusion section 52B. Rainwater hitting the inner surface of the downpipe 3 can cause an increase in pipeline pressure loss.

[0089] The piping member 5B described above constitutes a part of the downpipe of a rain gutter system that utilizes the siphon effect for rainwater drainage. The piping member 5B comprises a straight pipe section 51 that defines at least a part of the flow path of the downpipe, and a diffusion section 52B that is connected to the straight pipe section 51 and positioned in the flow path. The diffusion section 52B has an opening 521 with a flow path area smaller than that of the straight pipe section 51, and a guide surface 522 that guides rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. This configuration can stably promote the effect of the siphon effect.

[0090] Piping member 5B can be applied in place of piping member 5 to the rain gutter system 1 in Figure 1 or the rain gutter system 10 in Figure 6.

[0091] [2.3 Variation 3] Figure 10 is a cross-sectional view of an example configuration of the piping member 5C of modified example 3. The piping member 5C in Figure 10 comprises a straight pipe section 51 and a diffusion section 52C. The diffusion section 52C is located in the middle section 51c of the straight pipe section 51, similar to the diffusion section 52B, but its shape is different from that of the diffusion section 52B.

[0092] The diffusion section 52C is connected to the straight pipe section 51 and positioned in the flow path 30. As shown in Figure 10, the diffusion section 52C is located in the middle section 51c of the straight pipe section 51. The diffusion section 52C is formed integrally with the straight pipe section 51 and is therefore connected to the straight pipe section 51.

[0093] The diffusion section 52C extends from the inner surface 510 of the straight pipe section 51 toward the central axis C1 of the straight pipe section 51. The diffusion section 52C is a plate-like structure with a uniform thickness. The diffusion section 52C has a through hole 525. The through hole 525 has an opening 521 on the first end 51a side of the straight pipe section 51 and an opening 523 on the second end 51b side of the straight pipe section 51. The inner circumferential shape of the through hole 525 in a plane perpendicular to the central axis C1 of the straight pipe section 51 increases from the opening 521 toward the opening 523. As a result, the inner surface of the through hole 525 includes a guide surface 522 that guides rainwater passing through the opening 521 toward the central axis C1 of the straight pipe section 51.

[0094] In this modified example, the through-hole 525 is located in the center of the diffusion section 52C. The through-hole 525 is circular when viewed from the direction of the central axis C1 of the straight pipe section 51. The through-hole 525 includes a portion where the inner diameter increases from the opening 521 to the opening 523. As a result, the inner surface of the through-hole 525 includes the guide surface 522. In this modified example, the inner diameter D2 of the opening 521 is smaller than the inner diameter D1 of the straight pipe section 51. The inner diameter D3 of the opening 523 is smaller than the inner diameter D1 of the straight pipe section 51 and larger than the inner diameter D2 of the opening 521. In this modified example, the edge of the opening 521 is rounded (R-shaped).

[0095] Furthermore, the diffusion section 52C of the piping member 5C in Figure 10 can be described as having a shape in which the gap between the guide section 54 and the inner surface 510 of the straight pipe section 51 is filled, compared to the diffusion section 52B of the piping member 5B in Figure 9.

[0096] In the piping member 5C of Figure 10, the straight pipe section 51 has an opening 511 at the first end 51a and an opening 512 at the second end 51b. In this modified example, the opening 511 defines the inlet of the piping member 5C, and the opening 512 defines the outlet of the piping member 5C.

[0097] In the diffusion section 52C shown in Figure 10, the guide surface 522 directs the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. Therefore, the diffusion section 52C diffuses the rainwater that has passed through the opening 521 by the guide surface 522. The rainwater diffused by the diffusion section 52C hits the inner surface of the downpipe 3. In Figure 10, the rainwater diffused by the diffusion section 52C hits the inner surface 510 of the straight pipe section 51. Rainwater hitting the inner surface of the downpipe 3 can cause an increase in pipeline pressure loss.

[0098] The piping member 5C described above constitutes a part of the downpipe of a rain gutter system that utilizes the siphon effect for rainwater drainage. The piping member 5C comprises a straight pipe section 51 that defines at least a part of the flow path of the downpipe, and a diffusion section 52C that is connected to the straight pipe section 51 and positioned in the flow path. The diffusion section 52C has an opening 521 with a flow path area smaller than that of the straight pipe section 51, and a guide surface 522 that guides rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. This configuration can stably promote the effect of the siphon effect.

[0099] Piping member 5C can be applied in place of piping member 5 to the rain gutter system 1 in Figure 1 or the rain gutter system 10 in Figure 6.

[0100] [2.4 Modification 4] Figure 11 is a cross-sectional view of an example configuration of the piping member 5D of modified example 4. The piping member 5D in Figure 11 comprises a straight pipe section 51 and a diffusion section 52D. The diffusion section 52D has a partition wall section 53 and a guide section 54, similar to the diffusion section 52, but its position relative to the straight pipe section 51 is different from that of the diffusion section 52.

[0101] In Figure 11, the diffusion section 52D is connected to the straight pipe section 51 and positioned in the flow path 30. In this modified example, as shown in Figure 11, the diffusion section 52D is located at the first end 51a of the straight pipe section 51. In this modified example, the diffusion section 52D is formed integrally with the straight pipe section 51 and is therefore connected to the straight pipe section 51.

[0102] In the piping member 5D shown in Figure 11, the opening 521 of the diffusion section 52B defines the inlet of the piping member 5D. In the piping member 5D shown in Figure 11, the straight pipe section 51 has an opening 512 at the second end 51b. In this modified example, the opening 512 of the straight pipe section 51, rather than the opening 523 of the diffusion section 52B, defines the outlet of the piping member 5B.

[0103] In the diffusion section 52D shown in Figure 11, the guide surface 522 directs the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. Therefore, the diffusion section 52D diffuses the rainwater that has passed through the opening 521 by the guide surface 522. The rainwater diffused by the diffusion section 52D hits the inner surface of the downpipe 3. In Figure 11, the rainwater diffused by the diffusion section 52D hits the inner surface 510 of the straight pipe section 51. Rainwater hitting the inner surface of the downpipe 3 can cause an increase in pipeline pressure loss.

[0104] The piping member 5D described above constitutes a part of the downpipe of a rain gutter system that utilizes the siphon effect for rainwater drainage. The piping member 5D comprises a straight pipe section 51 that defines at least a portion of the flow path of the downpipe, and a diffusion section 52D that is connected to the straight pipe section 51 and positioned in the flow path. The diffusion section 52D has an opening 521 with a flow path area smaller than that of the straight pipe section 51, and a guide surface 522 that guides rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. This configuration can stably promote the effect of the siphon effect.

[0105] Piping member 5D can be applied in place of piping member 5 to the rain gutter system 1 in Figure 1 or the rain gutter system 10 in Figure 6.

[0106] [2.5 Variation 5] Figure 12 is a cross-sectional view of an example configuration of the piping member 5E of modified example 5. The piping member 5E in Figure 12 comprises a straight pipe section 51 and a diffusion section 52E.

[0107] The diffusion section 52E is connected to the straight pipe section 51 and positioned in the flow path 30. As shown in Figure 12, the diffusion section 52E is located at the second end 51b of the straight pipe section 51. The diffusion section 52E is formed integrally with the straight pipe section 51 and is therefore connected to the straight pipe section 51.

[0108] As shown in Figure 12, the diffusion section 52E comprises a partition section 53E and a guide section 54E.

[0109] The partition wall 53E extends from the inner surface 510 of the straight pipe section 51 toward the central axis C1 of the straight pipe section 51. The partition wall 53E is a plate-like structure with a uniform thickness. The partition wall 53E has an opening 523. As a result, the opening 523 is located inside the straight pipe section 51. In other words, the diffusion section 52E is connected to the straight pipe section 51 such that the opening 523 is located inside the straight pipe section 51. The opening 523 is in the center of the partition wall 53E. Viewed from the direction of the central axis C1 of the straight pipe section 51, the partition wall 53E is annular. The flow area of ​​the opening 523 is smaller than that of the straight pipe section 51. In a plane perpendicular to the central axis C1 of the straight pipe section 51, the opening 523 is circular. The inner diameter D3 of the opening 523 is smaller than the inner diameter D1 of the straight pipe section 51.

[0110] The guide portion 54E protrudes from the edge of the opening 523 of the partition wall portion 53E toward the upstream side of the downpipe 3, for example, toward the second end 51b of the straight pipe portion 51 toward the first end 51a. The guide portion 54E surrounds the entire circumference of the opening 523. The guide portion 54E has an opening 521 on the opposite side of the guide portion 54E from the opening 523. The inner diameter D2 of the opening 521 is smaller than the inner diameter D1 of the straight pipe portion 51 and the inner diameter D3 of the opening 523.

[0111] The guide portion 54E is hollow and frustoconical. In this modified example, the guide portion 54E is hollow and frustoconical. The outer and inner circumferential shapes of the guide portion 54E in the plane perpendicular to the central axis C1 of the straight pipe portion 51 are circular. The outer and inner circumferential shapes of the guide portion 54E in the plane perpendicular to the central axis C1 of the straight pipe portion 51 become smaller from the second end 51b to the first end 51a of the straight pipe portion 51.

[0112] In this modified example, the inner circumferential surface of the guide portion 54E functions as a guide surface 522 for rainwater passing through the opening 521. The guide surface 522 faces inward towards the straight pipe portion 51. The guide surface 522 guides the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe portion 51. The guide surface 522 moves further away from the central axis C1 of the straight pipe portion 51 as it moves downstream from the opening 521 towards the downpipe 3. In this modified example, the inclination of the guide surface 522 is constant. That is, the increment of the distance between the guide surface 522 and the central axis C1 in the plane perpendicular to the central axis C1 of the straight pipe portion 51, relative to the distance from the opening 521, is constant.

[0113] In the piping member 5E shown in Figure 12, the opening 511 of the straight pipe section 51 defines the inlet of the piping member 5E. In the piping member 5E shown in Figure 12, the opening 523 of the diffusion section 52E defines the outlet of the piping member 5E.

[0114] In the diffusion section 52E shown in Figure 12, the guide surface 522 directs the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. Therefore, the diffusion section 52E diffuses the rainwater that has passed through the opening 521 by the guide surface 522. The rainwater diffused by the diffusion section 52E hits the inner surface of the downpipe 3. In Figure 12, the rainwater diffused by the diffusion section 52E hits the inner surface 32a of the second downpipe 32. Rainwater hitting the inner surface of the downpipe 3 can cause an increase in pipeline pressure loss.

[0115] The piping member 5E described above constitutes a part of the downpipe of a rain gutter system that utilizes the siphon effect for rainwater drainage. The piping member 5E comprises a straight pipe section 51 that defines at least a part of the flow path of the downpipe, and a diffusion section 52E that is connected to the straight pipe section 51 and positioned in the flow path. The diffusion section 52E has an opening 521 with a flow path area smaller than that of the straight pipe section 51, and a guide surface 522 that guides rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. This configuration can stably promote the effect of the siphon effect.

[0116] Piping member 5E can be applied in place of piping member 5 to the rain gutter system 1 in Figure 1 or the rain gutter system 10 in Figure 6.

[0117] [2.6 Variation 6] Figure 13 is a cross-sectional view of an example configuration of the piping member 5F of modified example 6. The piping member 5F in Figure 13 comprises a straight pipe section 51 and a diffusion section 52F.

[0118] The diffusion section 52F is connected to the straight pipe section 51 and positioned in the flow path 30. As shown in Figure 13, the diffusion section 52F extends across the intermediate section 51c and the second end section 51b of the straight pipe section 51. The diffusion section 52F is formed integrally with the straight pipe section 51 and is therefore connected to the straight pipe section 51.

[0119] The diffusion section 52F in Figure 13 defines an internal flow path 526 that connects to the space enclosed by the inner surface 510 of the straight pipe section 51. The internal flow path 526 includes a narrowing flow path 526a and an expanding flow path 526b. The narrowing flow path 526a and the expanding flow path 526b are arranged in this order in the direction from the first end 51a to the second end 51b of the straight pipe section 51. The boundary between the narrowing flow path 526a and the expanding flow path 526b defines an opening 521 with a flow path area smaller than that of the straight pipe section 51.

[0120] The flow area of ​​the narrowing channel 526a decreases from the first end 51a to the second end 51b of the straight pipe section 51. In other words, the inner circumferential shape of the narrowing channel 526a in the plane perpendicular to the central axis C1 of the straight pipe section 51 decreases from the first end 51a to the opening 521. As a result, the inner surface of the narrowing channel 526a defines a tapered surface 524 that extends from the inner surface 510 of the straight pipe section 51 toward the opening 521 in a direction that does not perpendicular to the central axis C1 of the straight pipe section 51 but intersects it. The narrowing channel 526a connects to the space enclosed by the inner surface 510 of the straight pipe section 51 on the opposite side of the opening 521.

[0121] The flow area of ​​the expanded channel 526b increases from the first end 51a to the second end 51b of the straight pipe section 51. In other words, the inner circumferential shape of the expanded channel 526b in a plane perpendicular to the central axis C1 of the straight pipe section 51 increases from the opening 521 to the second end 51b. As a result, the inner surface of the expanded channel 526b defines a guide surface 522 that directs rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. The expanded channel 526b has an opening 523 on the opposite side of the opening 521.

[0122] In this modified example, the central axis C2 of the internal flow path 526 coincides with the central axis C1 of the straight pipe section 51. The internal flow path 526 is circular when viewed from the direction of the central axis C1 of the straight pipe section 51. In this modified example, the inner diameter D2 of the opening 521 is smaller than the inner diameter D1 of the straight pipe section 51. The inner diameter D3 of the opening 523 is smaller than the inner diameter D1 of the straight pipe section 51 and larger than the inner diameter D2 of the opening 521.

[0123] In the piping member 5F shown in Figure 13, the straight pipe section 51 has an opening 511 at its first end 51a, and the diffusion section 52F has an opening 523. In this modified example, the opening 511 defines the inlet of the piping member 5F. In this modified example, the opening 523 of the diffusion section 52F defines the outlet of the piping member 5F.

[0124] In the diffusion section 52F shown in Figure 13, the guide surface 522 directs the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. Therefore, the diffusion section 52F diffuses the rainwater that has passed through the opening 521 by the guide surface 522. The rainwater diffused by the diffusion section 52F hits the inner surface of the downpipe 3. In Figure 13, the rainwater diffused by the diffusion section 52F hits the inner surface 32a of the second downpipe 32. Rainwater hitting the inner surface of the downpipe 3 can cause an increase in pipeline pressure loss.

[0125] The piping member 5F described above constitutes a part of the downpipe of a rain gutter system that utilizes the siphon effect for rainwater drainage. The piping member 5F comprises a straight pipe section 51 that defines at least a part of the flow path of the downpipe, and a diffusion section 52F that is connected to the straight pipe section 51 and positioned in the flow path. The diffusion section 52F has an opening 521 with a flow path area smaller than that of the straight pipe section 51, and a guide surface 522 that guides rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. This configuration can stably promote the effect of the siphon effect.

[0126] In the piping member 5F, the diffusion section 52F further has a tapered surface 524 that extends from the inner surface 510 of the straight pipe section 51 toward the opening 521 in a direction that intersects but is not perpendicular to the central axis C1 of the straight pipe section 51. This configuration can reduce pressure loss due to the opening 521.

[0127] The piping member 5F can be applied to the rain gutter system 1 in Figure 1 or the rain gutter system 10 in Figure 6, instead of the piping member 5.

[0128] [2.7 Variation 7] Figure 14 is a cross-sectional view of an example configuration of the piping member 5G in modified example 7. The piping member 5G in Figure 13 comprises a straight pipe section 51 and a diffusion section 52G.

[0129] The diffusion section 52G is connected to the straight pipe section 51 and positioned in the flow path 30. As shown in Figure 14, the diffusion section 52G extends across the intermediate section 51c and the second end section 51b of the straight pipe section 51. The diffusion section 52G is formed integrally with the straight pipe section 51 and is therefore connected to the straight pipe section 51.

[0130] The diffusion section 52G in Figure 14 defines an internal flow path 526, similar to the diffusion section 52F in Figure 13. As described above, the internal flow path 526 defines an opening 521, a guide surface 522, and a tapered surface 524.

[0131] In the diffusion section 52G, the corner B1 between the inner surface 510 of the straight pipe section 51 and the tapered surface 524 is rounded (R-shaped). This reduces the generation of turbulence at the corner B1 between the inner surface 510 of the straight pipe section 51 and the tapered surface 524. The degree of the rounded shape of corner B1 can be appropriately set according to the pipe diameter of the downpipe 3, the amount of rainwater passing through the downpipe 3, the installation environment of the rain gutter system 1, and various other conditions.

[0132] In the diffusion section 52G, the corner B2 between the tapered surface 524 and the guide surface 522 is rounded (R-shaped). Corner B2 corresponds to the edge of the opening 521. In other words, in the diffusion section 52G, the edge of the opening 521 is rounded (R-shaped). This reduces losses at the edge of the opening 521. The degree of the rounded shape of corner B2 can be appropriately set according to the pipe diameter of the downpipe 3, the amount of rainwater passing through the downpipe 3, the installation environment of the rain gutter system 1, and various other conditions.

[0133] In the piping member 5G shown in Figure 14, the straight pipe section 51 has an opening 511 at its first end 51a, and the diffusion section 52G has an opening 523. In this modified example, the opening 511 defines the inlet of the piping member 5G. In this modified example, the opening 523 of the diffusion section 52F defines the outlet of the piping member 5G.

[0134] In the diffusion section 52G shown in Figure 14, the guide surface 522 directs the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. Therefore, the diffusion section 52G diffuses the rainwater that has passed through the opening 521 by the guide surface 522. The rainwater diffused by the diffusion section 52G hits the inner surface of the downpipe 3. In Figure 14, the rainwater diffused by the diffusion section 52G hits the inner surface 32a of the second downpipe 32. Rainwater hitting the inner surface of the downpipe 3 can cause an increase in pipeline pressure loss.

[0135] The piping member 5G described above constitutes a part of the downpipe of a rain gutter system that utilizes the siphon effect for rainwater drainage. The piping member 5G comprises a straight pipe section 51 that defines at least a part of the flow path of the downpipe, and a diffusion section 52G that is connected to the straight pipe section 51 and positioned in the flow path. The diffusion section 52G has an opening 521 with a flow path area smaller than that of the straight pipe section 51, and a guide surface 522 that guides rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. This configuration can stably promote the effect of the siphon effect.

[0136] In the piping member 5G, the diffusion section 52G further has a tapered surface 524 that extends from the inner surface 510 of the straight pipe section 51 toward the opening 521 in a direction that intersects but is not perpendicular to the central axis C1 of the straight pipe section 51. This configuration can reduce pressure loss due to the opening 521.

[0137] In the piping member 5G, the corner B1 between the inner surface 510 of the straight pipe section 51 and the tapered surface 524 is rounded (R-shaped). This configuration reduces the generation of turbulence at the corner B1 between the inner surface 510 of the straight pipe section 51 and the tapered surface 524.

[0138] In the piping member 5G, the edge of the opening 521 (the corner B2 between the tapered surface 524 and the guide surface 522) is rounded (R-shaped). This configuration reduces losses at the edge of the opening 521.

[0139] Piping member 5G can be applied in place of piping member 5 to the rain gutter system 1 in Figure 1 or the rain gutter system 10 in Figure 6.

[0140] [2.8 Variation 8] Figure 15 is a perspective view of an example configuration of the piping member 5H of modified example 8. Figure 16 is a cross-sectional view of the piping member 5H of Figure 15. As shown in Figures 15 and 16, the piping member 5H comprises a straight pipe section 51 and a diffusion section 52H.

[0141] The diffusion section 52H is connected to the straight pipe section 51 and positioned in the flow path 30. In this modified example, the diffusion section 52H is located at the second end 51b of the straight pipe section 51. In this modified example, the diffusion section 52H is formed integrally with the straight pipe section 51 and is therefore connected to the straight pipe section 51.

[0142] The diffusion section 52H comprises a partition wall section 53, a guide section 54, a guide section 55, and a plurality of support sections 56. In the following text, to make it easier to distinguish between the guide section 54 and the guide section 55, the guide section 54 may be referred to as the first guide section 54, and the guide section 55 as the second guide section 55.

[0143] The second guide portion 55 is positioned within the opening 521 of the partition wall portion 53 when viewed from the direction of the central axis C1 of the straight pipe portion 51. In this modified example, the second guide portion 55 is solid and frustoconical. In this modified example, the second guide portion 55 is solid and frustoconical. The outer circumference shape of the second guide portion 55 in the plane perpendicular to the central axis C1 of the straight pipe portion 51 is circular. The outer circumference shape of the second guide portion 55 in the plane perpendicular to the central axis C1 of the straight pipe portion 51 increases from the first end 51a to the second end 51b of the straight pipe portion 51.

[0144] In this modified example, the outer circumferential surface of the second guide portion 55 functions as a guide surface 527 for rainwater passing through the opening 521. In the following, to make it easier to distinguish between the guide surface 522 of the first guide portion 54 and the guide surface 527 of the second guide portion 55, the guide surface 522 may be referred to as the first guide surface 522 and the guide surface 527 as the second guide surface 527.

[0145] The second guide surface 527 faces outward from the straight pipe section 51, not inward from the straight pipe section 51. "Facing outward from the straight pipe section 51" means that the second guide surface 527 is not facing the central axis C1 of the straight pipe section 51. The second guide surface 527 guides rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. In this modified example, the second guide surface 527 moves further away from the central axis C1 of the straight pipe section 51 as it moves downstream from the opening 521 of the downpipe 3. In this modified example, the inclination of the second guide surface 527 is constant. That is, the increment of the distance between the second guide surface 527 and the central axis C1 in a plane perpendicular to the central axis C1 of the straight pipe section 51, relative to the distance from the opening 521, is constant.

[0146] Multiple support sections 56 support the second guide section 55. In this modified example, the multiple support sections 56 connect the second guide section 55 to the first guide section 54. Figure 15 shows four support sections 56. The number of support sections 56 is not particularly limited, but it is desirable that they be able to support the second guide section 55 during rainwater drainage and not excessively obstruct rainwater drainage.

[0147] In the diffusion section 52H shown in Figures 15 and 16, the guide surface includes a first guide surface 522 and a second guide surface 527. Each of the first guide surface 522 and the second guide surface 527 guides the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. Therefore, the diffusion section 52H diffuses the rainwater that has passed through the opening 521 by the guide surfaces (first guide surface 522 and second guide surface 527). The rainwater diffused by the diffusion section 52H hits the inner surface of the downpipe 3. In Figure 16, the rainwater diffused by the diffusion section 52H hits the inner surface 32a of the second downpipe 32. The rainwater hitting the inner surface of the downpipe 3 can cause an increase in pipeline pressure loss. In particular, since the guide surface in the diffusion section 52H includes a first guide surface 522 and a second guide surface 527, it becomes easier to guide rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51, thereby further stably promoting the effect of the siphon phenomenon.

[0148] The piping member 5H described above constitutes a part of the downpipe of a rain gutter system that utilizes the siphon effect for rainwater drainage. The piping member 5H comprises a straight pipe section 51 that defines at least a part of the flow path of the downpipe, and a diffusion section 52H that is connected to the straight pipe section 51 and positioned in the flow path. The diffusion section 52H has an opening 521 with a flow path area smaller than that of the straight pipe section 51, and guide surfaces 522, 527 that guide rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. This configuration can stably promote the effect of the siphon effect.

[0149] In the piping member 5H, the guide surfaces 522 and 527 move further away from the central axis C1 of the straight pipe section 51 as they move downstream from the opening 521 towards the downpipe 3. This configuration makes it easier to guide rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51, thereby further stably promoting the effect of the siphon phenomenon.

[0150] In the piping member 5H, the guide surfaces 522 and 527 include a first guide surface 522 facing inward from the straight pipe section 51 and a second guide surface 527 facing outward from the straight pipe section 51. This configuration makes it easier to guide rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51, thereby further stably promoting the effect of the siphon phenomenon.

[0151] The piping member 5H can be applied in place of piping member 5 to the rain gutter system 1 in Figure 1 or the rain gutter system 10 in Figure 6.

[0152] [2.9 Modification 9] Figure 17 is a cross-sectional view of an example configuration of the piping member 5I in modified example 9. The piping member 5I in Figure 17 can be applied to the rain gutter system 1 in Figure 1 instead of the piping member 5.

[0153] The piping member 5I in Figure 17 comprises a straight pipe section 51 and a diffusion section 52I.

[0154] The diffusion section 52I is connected to the straight pipe section 51 and positioned in the flow path 30. As shown in Figure 17, the diffusion section 52I is located at the second end 51b of the straight pipe section 51. The diffusion section 52I is formed integrally with the straight pipe section 51 and is therefore connected to the straight pipe section 51.

[0155] The diffusion section 52I extends from the inner surface 510 of the straight pipe section 51 toward the central axis C1 of the straight pipe section 51. The diffusion section 52I is a plate-like structure with a uniform thickness. The diffusion section 52I has a through hole 528. The through hole 528 has an opening 521 on the first end 51a side of the straight pipe section 51 and an opening 523 on the second end 51b side of the straight pipe section 51. The inner circumferential shape of the through hole 528 in the plane perpendicular to the central axis C1 of the straight pipe section 51 increases from the opening 521 toward the opening 523.

[0156] In the diffusion section 52I, the length of the through-hole 528 is set such that the inner surface of the through-hole 528 functions as a guide surface 522, relative to the flow path area of ​​the through-hole 528. Here, the flow path area of ​​the through-hole 528 is the cross-sectional area of ​​the through-hole in a plane perpendicular to the central axis C1 of the straight pipe section 51. The flow path area of ​​the through-hole 528 is equal to the flow path area of ​​the opening 521. The length of the through-hole 528 is the dimension of the through-hole 528 in the direction of the central axis C1 of the straight pipe section 51. In particular, if the effect of turbulence is small in the rainwater flowing through the flow path 30 of the downpipe 3, the length of the through-hole 528 can be shortened. In Figure 17, the length of the guide surface 522 in the direction of the central axis C1 of the straight pipe section 51 can be made to match the thickness of the diffusion section 52I. The diffusion section 52I in Figure 17 can be formed by providing a through-hole in a plate-like portion, and has a simpler shape than, for example, the diffusion section 52 in Figure 3. Therefore, the manufacturing of the piping member 5I becomes easier.

[0157] In this modified example, the through-hole 528 is located in the center of the diffusion section 52I. The through-hole 528 is circular when viewed from the direction of the central axis C1 of the straight pipe section 51. In this modified example, the inner diameter D2 of the opening 521 is smaller than the inner diameter D1 of the straight pipe section 51. The inner diameter D3 of the opening 523 is larger than the inner diameter D2 of the opening 521 and smaller than the inner diameter D1 of the straight pipe section 51.

[0158] In the piping member 5I shown in Figure 17, the straight pipe section 51 has an opening 511 at its first end 51a, and the diffusion section 52I has an opening 523. In this modified example, the opening 511 defines the inlet of the piping member 5I, and the opening 523 defines the outlet of the piping member 5I.

[0159] In the diffusion section 52I shown in Figure 17, the guide surface 522 directs the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. Therefore, the diffusion section 52I diffuses the rainwater that has passed through the opening 521 via the guide surface 522. The rainwater diffused by the diffusion section 52I hits the inner surface of the downpipe 3. In Figure 17, the rainwater diffused by the diffusion section 52I hits the inner surface 510 of the straight pipe section 51. Rainwater hitting the inner surface of the downpipe 3 can cause an increase in pipeline pressure loss.

[0160] In particular, the piping member 5I is applied to the rain gutter system 1 in Figure 1 instead of the piping member 5. In the rain gutter system 1 in Figure 1, unlike the rain gutter system 10 in Figure 6, when the siphon effect is not occurring, the flow of rainwater generally falls from the outlet 2b along the pipe wall of the downpipe 3 and reaches the diffusion section 52I of the piping member 5I. As the amount of rainfall increases, rainwater accumulates above the diffusion section 52I of the piping member 5I, and the rainwater above the diffusion section 52I increases in flow velocity at the opening 521, which has a smaller flow path area than the straight pipe section 51, and is discharged downward from the diffusion section 52I along the guide surface 522. Therefore, the guide surface 522 of the diffusion section 52I can use the energy of the rainwater itself to guide the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51.

[0161] The piping member 5I described above constitutes a part of the downpipe of a rain gutter system that utilizes the siphon effect for rainwater drainage. The piping member 5I comprises a straight pipe section 51 that defines at least a portion of the flow path of the downpipe, and a diffusion section 52I that is connected to the straight pipe section 51 and positioned in the flow path. The diffusion section 52I has an opening 521 with a flow path area smaller than that of the straight pipe section 51, and a guide surface 522 that guides rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. This configuration can stably promote the effect of the siphon effect.

[0162] [2.10 Variation 10] Figure 18 is a cross-sectional view of an example configuration of the piping member 5J in modified example 10. The piping member 5J in Figure 18 can be applied to the rain gutter system 1 in Figure 1 instead of the piping member 5.

[0163] The piping member 5J in Figure 18 comprises a straight pipe section 51 and a diffusion section 52J.

[0164] The diffusion section 52J is connected to the straight pipe section 51 and positioned in the flow path 30. As shown in Figure 18, the diffusion section 52J extends across the intermediate section 51c and the second end section 51b of the straight pipe section 51. The diffusion section 52J is formed integrally with the straight pipe section 51 and is therefore connected to the straight pipe section 51.

[0165] The diffusion section 52J in Figure 18 defines an internal flow path 57 that connects to the space enclosed by the inner surface 510 of the straight pipe section 51. The internal flow path 57 includes a narrowing flow path 57a, a connecting flow path 57b, and an expanding flow path 57c. The narrowing flow path 57a, the connecting flow path 57b, and the expanding flow path 57c are arranged in this order in the direction from the first end 51a to the second end 51b of the straight pipe section 51.

[0166] The flow area of ​​the narrowing channel 57a decreases from the first end 51a to the second end 51b of the straight pipe section 51. In other words, the inner circumferential shape of the narrowing channel 57a in a plane perpendicular to the central axis C1 of the straight pipe section 51 decreases from the first end 51a to the second end 51b. As a result, the inner surface of the narrowing channel 57a defines a tapered surface 524 that extends from the inner surface 510 of the straight pipe section 51 toward the opening 521 in a direction that does not perpendicular to the central axis C1 of the straight pipe section 51 but intersects it. The narrowing channel 57a connects to the space enclosed by the inner surface 510 of the straight pipe section 51 on the opposite side of the opening 521.

[0167] The flow area of ​​the connecting channel 57b does not change from the first end 51a to the second end 51b of the straight pipe section 51. In other words, the inner circumferential shape of the connecting channel 57b in a plane perpendicular to the central axis C1 of the straight pipe section 51 is constant. In the diffusion section 52J, the connecting channel 57b is the part with the smallest cross-sectional area in the internal flow channel 57. The connecting channel 57b defines an opening 521 with a smaller flow area than the straight pipe section 51.

[0168] The flow area of ​​the expanded channel 57c increases from the first end 51a to the second end 51b of the straight pipe section 51. In other words, the inner circumferential shape of the expanded channel 57c in a plane perpendicular to the central axis C1 of the straight pipe section 51 increases from the first end 51a to the second end 51b. The inner surface of the expanded channel 57c defines a guide surface 522 that directs rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. The expanded channel 57c has an opening 523 on the opposite side of the opening 521.

[0169] In this modified example, the central axis C3 of the internal flow path 57 coincides with the central axis C1 of the straight pipe section 51. The internal flow path 57 is circular when viewed from the direction of the central axis C1 of the straight pipe section 51. In this modified example, the inner diameter D2 of the opening 521 is smaller than the inner diameter D1 of the straight pipe section 51. The inner diameter D3 of the opening 523 is smaller than the inner diameter D1 of the straight pipe section 51 and larger than the inner diameter D2 of the opening 521.

[0170] In the piping member 5J shown in Figure 18, the straight pipe section 51 has an opening 511 at its first end 51a, and the diffusion section 52J has an opening 523. In this modified example, the opening 511 defines the inlet of the piping member 5J. In this modified example, the opening 523 of the diffusion section 52J defines the outlet of the piping member 5J.

[0171] In the diffusion section 52J shown in Figure 18, the guide surface 522 directs the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. Therefore, the diffusion section 52J diffuses the rainwater that has passed through the opening 521 by the guide surface 522. The rainwater diffused by the diffusion section 52J hits the inner surface of the downpipe 3. In Figure 18, the rainwater diffused by the diffusion section 52J hits the inner surface 32a of the second downpipe 32. Rainwater hitting the inner surface of the downpipe 3 can cause an increase in pipeline pressure loss.

[0172] In particular, the piping member 5J is applied to the rain gutter system 1 in Figure 1 instead of the piping member 5. In the rain gutter system 1 in Figure 1, unlike the rain gutter system 10 in Figure 6, when the siphon effect is not occurring, the flow of rainwater generally falls from the outlet 2b along the pipe wall of the downpipe 3 and reaches the diffusion section 52J of the piping member 5J. As the amount of rainfall increases, rainwater accumulates above the diffusion section 52J of the piping member 5J, and the rainwater above the diffusion section 52J increases in flow velocity at the opening 521, which has a smaller flow path area than the straight pipe section 51, and is discharged downward from the diffusion section 52J along the guide surface 522. Therefore, the guide surface 522 of the diffusion section 52J can utilize the energy of the rainwater itself to guide the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51.

[0173] The piping member 5J described above constitutes a part of the downpipe of a rain gutter system that utilizes the siphon effect for rainwater drainage. The piping member 5J comprises a straight pipe section 51 that defines at least a part of the flow path of the downpipe, and a diffusion section 52J that is connected to the straight pipe section 51 and positioned in the flow path. The diffusion section 52J has an opening 521 with a flow path area smaller than that of the straight pipe section 51, and a guide surface 522 that guides rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. This configuration can stably promote the effect of the siphon effect.

[0174] In the piping member 5J, the guide surface 522 moves further away from the central axis C1 of the straight pipe section 51 as it moves downstream from the opening 521 towards the downpipe 3. This configuration makes it easier to guide rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51, thereby further stably promoting the effect of the siphon phenomenon.

[0175] In the piping member 5J, the diffusion section 52J further has a tapered surface 524 that extends from the inner surface 510 of the straight pipe section 51 toward the opening 521 in a direction that intersects but is not perpendicular to the central axis C1 of the straight pipe section 51. This configuration can reduce pressure loss due to the opening 521.

[0176] [2.11 Variation 11] Figure 19 is a schematic diagram of an example configuration of a rain gutter system 1K equipped with a piping member 5K of modification 11. The rain gutter system 1 in Figure 19 includes a gutter 2, a downpipe 3K, and a drain 4.

[0177] The downpipe 3K in Figure 19 comprises a first vertical pipe 31, a second vertical pipe 32, a piping member 5K, a first socket 35a, and a second socket 35b.

[0178] The piping component 5K constitutes part of the downpipe 3K of the rain gutter system 1K, which utilizes the siphon effect for rainwater drainage. The piping component 5K is installed in the rain gutter system 1K to stably promote the action of the siphon effect. In the downpipe 3K shown in Figure 19, the piping component 5K is located between the first vertical pipe 31 and the second vertical pipe 32. The piping component 5K in Figure 19 may be a vertical pipe similar to the first vertical pipe 31 and the second vertical pipe 32. The position of the piping component 5K in the downpipe 3K is set appropriately considering the degree to which the siphon effect occurs during rainwater drainage.

[0179] The piping member 5K comprises a straight pipe section 51K and a diffusion section 52.

[0180] The straight pipe section 51K defines at least a portion of the flow path 30 of the downpipe 3K. In this modified example, the internal space of the straight pipe section 51K, enclosed by the inner surface 510 of the straight pipe section 51K, becomes part of the flow path 30 of the downpipe 3K. The cross-section of the straight pipe section 51K perpendicular to the central axis C1 is circular. The central axis C1 of the straight pipe section 51K is also the pipe axis of the straight pipe section 51K. The material of the straight pipe section 51K is rigid polyvinyl chloride. The dimensions of the straight pipe section 51K, for example, the outer shape and thickness, may be set in accordance with the standard for rigid polyvinyl chloride pipes (general) of JIS K 6741 "Rigid Polyvinyl Chloride Pipe". The straight pipe section 51K is positioned such that the direction of the central axis C1 of the straight pipe section 51K coincides with the vertical direction.

[0181] In this modified example, the dimensions of the straight pipe section 51K are the same as at least one of the first vertical pipe 31 and the second vertical pipe 32 used in the downpipe 3K. Therefore, the straight pipe section 51K has a mark 51e on its outer surface to distinguish it from the vertical pipes (first vertical pipe 31 and / or the second vertical pipe 32) used in the downpipe 3K that have the same dimensions as the straight pipe section 51K. This allows the piping member 5K to be distinguished from the first vertical pipe 31 or the second vertical pipe 32, thereby improving the workability of the downpipe 3K. The mark 51e may be a letter, figure, symbol, three-dimensional shape, or color, or a combination thereof, that is recognizable by human perception.

[0182] In Figure 19, mark 51e has the function of indicating the orientation of the piping member 5K during installation. Mark 51e in Figure 19 is an arrow, and when installing the piping member 5K, the piping member 5K should be installed so that the arrow indicated by mark 51e points upward. In Figure 19, mark 51e is exposed in the downpipe 3K, but mark 51e may be placed on the outer surface of the first end 51a or the second end 51b of the straight pipe section 51K, and after construction, mark 51e may be hidden by other members.

[0183] The first socket 35a connects the first vertical pipe 31 to the piping member 5K. In Figure 19, the first socket 35a connects the downstream end of the first vertical pipe 31 to the upstream end (first end 51a) of the piping member 5K. The second socket 35b connects the second vertical pipe 32 to the piping member 5K. In Figure 19, the second socket 35b connects the upstream end of the second vertical pipe 32 to the downstream end (second end 51b) of the piping member 5K. The dimensions of the first socket 35a and the second socket 35b may be set in accordance with, for example, the JIS K 6739 standard "Rigid polyvinyl chloride pipe fittings for drainage".

[0184] As described above, the piping member 5K has a diffusion section 52, and the guide surface 522 of the diffusion section 52 guides the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. Therefore, the diffusion section 52 diffuses the rainwater that has passed through the opening 521 by the guide surface 522. The rainwater diffused by the diffusion section 52 hits the inner surface of the downpipe 3K. In Figure 19, the rainwater diffused by the diffusion section 52 hits the inner surface 510 of the straight pipe section 51K. The rainwater hitting the inner surface of the downpipe 3K can cause an increase in pipeline pressure loss.

[0185] The piping member 5K described above constitutes a part of the downpipe 3K of the rain gutter system 1K that utilizes the siphon effect for rainwater drainage. The piping member 5K comprises a straight pipe section 51K that defines at least a part of the flow path 30 of the downpipe 3K, and a diffusion section 52 that is connected to the straight pipe section 51K and positioned in the flow path. The diffusion section 52 has an opening 521 with a flow path area smaller than that of the straight pipe section 51K, and a guide surface 522 that guides rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51K. This configuration can stably promote the effect of the siphon effect.

[0186] [2.12 Variation 12] Figure 20 is a cross-sectional view of an example configuration of the piping member 5L of modified example 12. The piping member 5L in Figure 20 comprises a straight pipe section 51 and a diffusion section 52L.

[0187] The diffusion section 52L is connected to the straight pipe section 51 and positioned in the flow path 30. As shown in Figure 20, the diffusion section 52L is located at the second end 51b of the straight pipe section 51. The diffusion section 52L is formed integrally with the straight pipe section 51 and is therefore connected to the straight pipe section 51.

[0188] The diffusion section 52L comprises a partition section 53 and a guide section 54L.

[0189] The guide portion 54L protrudes from the edge of the opening 521 of the partition wall portion 53 toward the downstream side of the downpipe 3, for example, toward the second end 51b of the straight pipe portion 51 from the first end 51a. The guide portion 54L surrounds the entire circumference of the opening 521. In this modified example, the guide portion 54 is cylindrical. In particular, the guide portion 54L is cylindrical. The outer and inner circumferential shapes of the guide portion 54L in a plane perpendicular to the central axis C1 of the straight pipe portion 51 are circular. The outer and inner circumferential shapes of the guide portion 54 in a plane perpendicular to the central axis C1 of the straight pipe portion 51 do not change toward the second end 51b of the straight pipe portion 51 from the first end 51a.

[0190] In this modified example, the inner circumferential surface of the guide section 54L functions as a guide surface 522 for rainwater passing through the opening 521. The guide surface 522 faces inward towards the straight pipe section 51. The guide surface 522 guides the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. In this modified example, the distance between the guide surface 522 and the central axis C1 of the straight pipe section 51 does not change in the direction of the central axis C1 of the straight pipe section 51. The diffusion section 52L in Figure 20 differs from the diffusion section 52 in Figure 3 in that the guide surface 522 is not inclined with respect to the central axis C1 of the straight pipe section 51. In the diffusion section 52 of Figure 3, even when the amount of rainfall is relatively small and the space between the piping member 5 and the outlet 2b is not full of water, the guide surface 522 can guide the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. In contrast, in the diffusion section 52L of Figure 20, when the amount of rainfall is relatively large and the space between the piping member 5 and the outlet 2b is full or nearly full (even if air bubbles are mixed in), the guide surface 522 can guide the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. In other words, when the space between the piping member 5 and the outlet 2b is full or nearly full, the opening 521 increases the flow velocity of the rainwater, so even if the guide surface 522 is not inclined with respect to the central axis C1 of the straight pipe section 51, the guide surface 522 can still diffuse the rainwater. The guide surface 522 only needs to be able to guide the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51 when the space between the piping member 5 and the outlet 2b is full or nearly full.

[0191] The diffusion section 52L has an opening 523 on the opposite side of the opening 521 in the guide section 54L. The opening 523 defines the outlet of the piping member 5L. Therefore, in the downpipe 3, rainwater from the piping member 5L enters the second vertical pipe 32 through the opening 523, which is the outlet of the piping member 5L. In this modified example, the inner diameter of the opening 523 is equal to the inner diameter D2 of the opening 521, and is therefore smaller than the inner diameter D1 of the straight pipe section 51.

[0192] In the diffusion section 52L shown in Figure 20, the guide surface 522 directs the rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. Therefore, the diffusion section 52L diffuses the rainwater that has passed through the opening 521 by the guide surface 522. The rainwater diffused by the diffusion section 52L hits the inner surface of the downpipe 3. In Figure 20, the rainwater diffused by the diffusion section 52L hits the inner surface 32a of the second downpipe 32. Rainwater hitting the inner surface of the downpipe 3 can cause an increase in pipeline pressure loss.

[0193] The piping member 5L described above constitutes a part of the downpipe of a rain gutter system that utilizes the siphon effect for rainwater drainage. The piping member 5L comprises a straight pipe section 51 that defines at least a part of the flow path of the downpipe, and a diffusion section 52L that is connected to the straight pipe section 51 and positioned in the flow path. The diffusion section 52L has an opening 521 with a flow path area smaller than that of the straight pipe section 51, and a guide surface 522 that guides rainwater passing through the opening 521 away from the central axis C1 of the straight pipe section 51. This configuration can stably promote the effect of the siphon effect.

[0194] The piping component 5L can be applied in place of piping component 5 to the rain gutter system 1 in Figure 1 or the rain gutter system 10 in Figure 6.

[0195] [2.13 Other variations] In one modified example, the shape and size of part or all of the diffusion section may differ from those of the above embodiment and modified example. For example, unlike the above embodiment, the guide section of the diffusion section may be a hollow truncated pyramidal shape. The shapes of the straight pipe section and the diffusion section in a plane perpendicular to the central axis of the straight pipe section may be polygonal rather than circular. In the above embodiment, the guide surface is linear in the cross-section of the diffusion section in a plane containing the central axis of the straight pipe section, but in the modified example, it may be curved or folded.

[0196] In one modified example, the position of the diffusion section in the straight pipe section is not particularly limited.

[0197] In one modified example, the diffusion section may be provided with multiple openings and multiple guide surfaces.

[0198] In one modified example, the straight pipe section and the diffusion section do not have to be formed as a continuous, integrated unit. The straight pipe section and the diffusion section may be separate parts. The straight pipe section and the diffusion section may be mechanically joined by assembly or the like. The materials of the straight pipe section and the diffusion section may be different.

[0199] In one modified example, the material of the piping component does not necessarily have to be rigid polyvinyl chloride. The material of the piping component may be determined according to the requirements of the rain gutter system, and may be, for example, a synthetic resin such as polyethylene.

[0200] In one variation, the rain gutter system 1 does not necessarily have to include a gutter 2. For example, if the building 11 has a structure that includes a drain opening such as a balcony, the downpipe 3 may be connected to the drain opening of the building 11. The same applies to the rain gutter system 10.

[0201] In one modified example, the downpipe 3 may have a different configuration from the example of the above embodiment. The downpipe 3 may have other members in addition to the first vertical pipe 31, the second vertical pipe 32, and the piping member 5. In another example, the downpipe 3 may have the piping member as the upstream end of the downpipe 3. For example, in Figure 1, the piping member 5 may be directly connected to the outlet 2b. For example, in Figure 6, the piping member 5 may be directly connected to the second elbow 7b. The downpipe 3 may consist only of the piping member 5. That is, the piping member 5 may constitute the entire flow path 30 of the downpipe 3.

[0202] [3. Appearance] As is clear from the above embodiments and modifications, this disclosure includes the following aspects. In the following, reference numerals are enclosed in parentheses solely to indicate their correspondence with the embodiments. Note that, for the sake of readability, the notation of reference numerals enclosed in parentheses may be omitted after the first occurrence.

[0203] The first embodiment is a piping member (5;5A;5B;5C;5D;5E;5F;5G;5H;5I;5J;5K;5L) that constitutes part of a downpipe (3) of a rain gutter system (1;1K;10) that utilizes the siphon effect for draining rainwater, comprising a straight pipe section (51;51K) that defines at least part of the flow path (30) of the downpipe (3;3K), and a diffusion section (52;52A;52B;52C;52D;52E;52F;52G;52H;52I;52J;52L) that is connected to the straight pipe section (51;51K) and arranged in the flow path (30). The diffusion section has an opening (521) with a smaller flow area than the straight pipe section, and guide surfaces (522, 527) that guide rainwater passing through the opening (521) away from the central axis (C1) of the straight pipe section (51). This configuration can stably promote the effect of the siphon phenomenon.

[0204] The second embodiment is a piping member (5; 5A; 5B; 5C; 5D; 5E; 5F; 5G; 5H; 5J; 5K) based on the first embodiment. In the second embodiment, the guide surface (522) moves further away from the central axis (C1) of the straight pipe section (51) as it moves downstream from the opening (521) towards the downpipe (3; 3K). This embodiment makes it easier to guide rainwater passing through the opening (521) away from the central axis (C1) of the straight pipe section (51; 51K), thereby further stably promoting the effect of the siphon phenomenon.

[0205] A third embodiment is a piping member (5; 5A; 5B; 5C; 5D; 5E; 5F; 5G; 5H; 5J; 5K) based on the first or second embodiment. In the third embodiment, the guide surface includes at least one of a first guide surface (522) facing inward of the straight pipe section (51; 51K) and a second guide surface (527) facing outward of the straight pipe section. This embodiment makes it easier to guide rainwater passing through the opening (521) away from the central axis (C1) of the straight pipe section (51; 51K), thereby further stably promoting the effect of the siphon phenomenon.

[0206] The fourth embodiment is a piping member (5; 5A; 5B; 5C; 5D; 5E; 5F; 5G; 5H; 5J; 5K; 5L) based on any one of the first to third embodiments. In the fourth embodiment, the length of the guide surface (522, 527) in the direction of the central axis (C1) of the straight pipe section (51; 51K) is set such that a predetermined area downstream of the diffusion section (52; 52A; 52B; 52C; 52D; 52E; 52F; 52G; 52H; 52J; 52L) in the downpipe (3) is filled with water. This embodiment can stably promote the effect of the siphon phenomenon.

[0207] The fifth embodiment is a piping member (5A; 5F; 5G; 5J; 5K) based on any one of the first to fourth embodiments. In the fifth embodiment, the diffusion portion (52A) further has a tapered surface (524) extending from the inner surface (510) of the straight pipe portion (51; 51K) toward the opening (521) in a direction that does not perpendicular to but intersects the central axis (C1) of the straight pipe portion (51). This embodiment can reduce pressure loss due to the opening (521).

[0208] The sixth embodiment is a piping member (5G) based on the fifth embodiment. In the sixth embodiment, the corner (B1) between the inner surface (510) of the straight pipe section (51) and the tapered surface (524) is rounded in shape. This embodiment can reduce the generation of turbulence at the corner (B1) between the inner surface (510) of the straight pipe section (51) and the tapered surface (524).

[0209] The seventh embodiment is a piping member (5; 5B; 5C; 5D; 5F; 5G; 5H; 5J; 5K; 5L) based on any one of the first to sixth embodiments. In the seventh embodiment, the edge of the opening (521) is rounded. This embodiment can reduce losses at the edge of the opening (521).

[0210] The eighth embodiment is a piping member (5; 5A; 5B; 5C; 5D; 5E; 5F; 5G; 5H; 5I; 5J; 5K; 5L) based on any one of the first to seventh embodiments. In the eighth embodiment, the center (O1) of the opening (521) lies on the central axis (C1) of the straight pipe section (51; 51K). This embodiment can stably promote the action due to the siphon phenomenon.

[0211] The ninth embodiment is a piping member (5K) based on any one of the first to eighth embodiments. In the ninth embodiment, the straight pipe section (51K) has a mark (51e) on its outer surface to distinguish it from the vertical pipes (first vertical pipe 31, second vertical pipe 32) used in the downpipe (3K) that have the same dimensions as the straight pipe section (51K). This embodiment can improve the workability of the downpipe (3K).

[0212] The tenth embodiment is a rain gutter system (1;1K;10). The rain gutter system (1;1K;10) has piping members (5;5A;5B;5C;5D;5E;5F;5G;5H;5I;5J;5K;5L) in any one of the first to ninth embodiments and comprises a downpipe (3;3K) connected to a rainwater outlet (2b) from a building (11;110), and a drain (4) positioned at the outlet (2b). This embodiment can stably promote the action due to the siphon effect.

[0213] The eleventh embodiment is a rain gutter system (1;1K) based on the tenth embodiment. In the eleventh embodiment, the downpipe (3;3K) is directly connected to the downspout (2b). This embodiment can stably promote the action due to the siphon effect.

[0214] A twelfth embodiment is a rain gutter system (10) based on the tenth embodiment. In the twelfth embodiment, the rain gutter system (10) further comprises a connecting pipe (6) between the downspout (2b) and the downpipe (3), a first elbow (7a) connecting the upstream end (6a) of the connecting pipe (6) to the downspout (2b), and a second elbow (7b) connecting the downstream end (6b) of the connecting pipe (6) to the upstream end (3a) of the downpipe (3). This embodiment can stably promote the action due to the siphon effect.

[0215] The second to ninth aspects described above are optional elements. [Industrial applicability]

[0216] This disclosure is applicable to piping components and rain gutter systems. Specifically, this disclosure is applicable to piping components that constitute part of the downpipe of a rain gutter system that utilizes the siphon effect for rainwater drainage, and to rain gutter systems that utilize the siphon effect for rainwater drainage. [Explanation of Symbols]

[0217] 1.1K.10 ​​Rain Gutter System 2b Drop-off 3,3K Downpipe 30 flow channels 4 Drain 5.5A~5L Piping Components 51,51K straight pipe section 51e Mark 52, 52A~52J, 52L Diffusion section 521 Aperture 522 Guide surface (first guide surface) 524 Tapered surface 527 Guide surface (second guide surface) 6. Gutter 7a First Elbow 7b Second Elbow B1 Corner (the corner between the inner surface of the straight pipe section and the tapered surface) C1 Center axis C1 O1 center 11,110 buildings

Claims

1. A piping component that constitutes part of the downpipe of a rain gutter system that utilizes the siphon effect for rainwater drainage, A straight pipe section defining at least a portion of the flow path of the downpipe, A diffusion section is connected to the straight pipe section and placed in the flow path, Equipped with, The aforementioned diffusion section is An opening with a smaller flow area than the aforementioned straight pipe section, A guide surface that directs rainwater passing through the opening away from the central axis of the straight pipe section, It has, If the inner diameter of the straight pipe section is D1, the inner diameter of the opening is D2, and the inner diameter of the opening on the opposite side of the opening in the diffusion section is D3, then D2 ≤ D3 < D1 satisfies the following conditions. Piping components.

2. A piping component that constitutes part of the downpipe of a rain gutter system that utilizes the siphon effect for rainwater drainage, A straight pipe section defining at least a portion of the flow path of the downpipe, A diffusion section is connected to the straight pipe section and placed in the flow path, Equipped with, The aforementioned diffusion section is An opening with a smaller flow area than the aforementioned straight pipe section, A guide surface that directs rainwater passing through the opening away from the central axis of the straight pipe section, It has, The guide surface faces outward from the straight pipe section. Piping components.

3. A piping component that constitutes part of the downpipe of a rain gutter system that utilizes the siphon effect for rainwater drainage, A straight pipe section defining at least a portion of the flow path of the downpipe, A diffusion section is connected to the straight pipe section and placed in the flow path, Equipped with, The aforementioned diffusion section is An opening with a smaller flow area than the aforementioned straight pipe section, A guide surface that directs rainwater passing through the opening away from the central axis of the straight pipe section, A tapered surface extending from the inner surface of the straight pipe section toward the opening in a direction that does not intersect the central axis of the straight pipe section but does not perpendicular to it, It has, The angle between the inner surface of the straight pipe section and the tapered surface is rounded (R-shaped). Piping components.

4. The guide surface moves further away from the central axis of the straight pipe section as it moves downstream from the opening of the downpipe. The piping member according to claim 1.

5. The guide surface includes at least one of a first guide surface facing inward towards the straight pipe section and a second guide surface facing outward towards the straight pipe section. The piping member according to claim 1.

6. The length of the guide surface in the direction of the central axis of the straight pipe section is set such that a predetermined area downstream of the diffusion section in the downpipe is filled with water. A piping member according to any one of claims 1 to 5.

7. The diffusion portion further has a tapered surface extending from the inner surface of the straight pipe portion toward the opening in a direction that does not intersect the central axis of the straight pipe portion but does not perpendicular to it. The piping member according to claim 1 or 2.

8. The angle between the inner surface of the straight pipe section and the tapered surface is rounded (R-shaped). The piping member according to claim 7.

9. The edge of the opening is rounded (R-shaped). A piping member according to any one of claims 1 to 8.

10. The center of the opening is on the central axis of the straight pipe section, A piping member according to any one of claims 1 to 9.

11. The straight pipe section has a mark on its outer surface to distinguish it from straight pipes of the same dimensions as the straight pipe section used in the downpipe. A piping member according to any one of claims 1 to 10.

12. A downpipe having a piping member according to any one of claims 1 to 11, and connected to a rainwater outlet from a building, A drain placed at the aforementioned outlet, Equipped with, Rain gutter system.

13. The downpipe is directly connected to the outlet. The rain gutter system according to claim 12.

14. A connecting pipe located between the aforementioned drain outlet and the aforementioned downpipe, A first elbow connects the upstream end of the aforementioned drainpipe to the aforementioned outlet, A second elbow connects the downstream end of the aforementioned downpipe to the upstream end of the aforementioned downpipe, It also has, The rain gutter system according to claim 12.

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