JP2024050499A - Rainwater drainage piping structure - Google Patents

Abstract

[Problem] The object of the present invention is to provide a rainwater drainage piping structure. [Solution] The rainwater drainage piping structure of the present invention is a rainwater drainage piping structure comprising a drainage member into which rainwater is introduced, a nominal pipe connected to the drainage member, a downpipe connected to the nominal pipe, and a finned joint incorporated between the nominal pipe and the downpipe or into the downpipe, and is characterized in that the length of the nominal pipe is 1000 mm or less. In the rainwater drainage piping structure of the present invention, it is preferable that the inner diameter of the nominal pipe is larger than the inner diameter of the downpipe. [Selected Figure] Figure 4

Description

The present invention relates to a storm water drainage piping structure.

Siphon drain members with high drainage capabilities are widely used in large eaves gutters that are installed under the eaves of large buildings in large facilities such as factories, warehouses, and shopping centers (see, for example, Patent Document 1).

This siphon drain member is generally configured with a lower drain member that is placed on the underside of the bottom plate of the eaves gutter, and an upper drain member that is placed on the upper side and has a siphon section.

Patent No. 6784708

Since eaves gutters are hung from the eaves tip of the roof and installed away from the wall of the building, in order to connect drainage components such as drain members attached to the eaves gutters to the downspout supported along the wall, it is necessary to construct a joint in the rainwater drainage piping structure via an elbow pipe with a large curvature or a horizontal pipe combined with an elbow pipe called a call gutter.
In large buildings such as factories and warehouses, the eaves are often short, so elbow pipes with a small radius of curvature that fit snugly in an S-shape must be connected to shorten the drain pipe. Also, to ensure the siphon effect, it is necessary to take measures such as keeping the drain pipe to 2m or less.
However, when the above-mentioned structure is adopted, the drainage member attached to the eaves gutter moves relative to the downspout due to thermal expansion and contraction of the roof material, and the stress caused by the relative movement is concentrated at the joint of the rainwater drainage pipe. The relative movement between the drainage member and the downspout can also occur due to wind pressure during strong winds.
If the amount of relative movement is large, cracks may occur in the joint. Also, if a short lead pipe is used to ensure a good fit and an elbow pipe with a small radius of curvature is used, the lead pipe may bend due to the relative movement, which may cause cracks in the joint.

The present invention was made in consideration of the above-mentioned circumstances, and aims to provide a drainage member that employs a structure that alleviates stress concentration that occurs at the connection between the drain member and the downspout due to thermal contraction, wind force during strong winds, etc.

In order to solve the above problems, the present invention proposes the following aspects.
"1" The rainwater drainage piping structure of this embodiment is a rainwater drainage piping structure comprising a drainage member into which rainwater is introduced, a nominal gutter connected to the drainage member, a downpipe connected to the nominal gutter, and a finned joint incorporated between the nominal gutter and the downpipe or into the downpipe, and is characterized in that the length of the nominal gutter is 1000 mm or less.

In the rainwater drainage piping structure described above, the use of a finned joint makes it easier to temporarily form a rainwater puddle on the upstream side of the finned joint. This temporary rainwater puddle can suppress the intake of air on the upstream side of the finned joint and suppress the generation of vortexes. This effectively creates a siphon effect in the pipe, improving drainage performance.
Rainwater passing through the flow path of a finned joint attempts to swirl as it passes, but this is straightened by the fins extending along the pipe axis, so that it is drained smoothly after passing through the fins.
In addition, the improved drainage performance allows the length of the drain to be shortened to 1,000 mm or less.
By shortening the length of the nominal gutter, the amount of resin that makes up the nominal gutter can be reduced, and the stress generated in the nominal gutter and the stress generated in the nominal gutter and its connection part can also be reduced.
The above-mentioned structure can reduce stress concentration on the lower gutter and its connection when the drainage member and the downspout move relative to each other due to thermal expansion of the roof or wind pressure during strong winds, thus eliminating the risk of cracks occurring in the lower gutter and its connection.

"2" In the rainwater drainage piping structure of this embodiment, a configuration can be adopted in which the inner diameter of the pipe of the downspout is larger than the inner diameter of the pipe of the downspout.

If the inner diameter of the downspout pipe is made larger than that of the upright pipe, and a siphon effect is induced in the upright pipe downstream of the finned joint to improve drainage, a large amount of rainwater flowing through the downspout pipe with its larger inner diameter can be efficiently discharged to the upright pipe. This makes it possible to drain large amounts of rainwater during heavy rains.

"3" In the rainwater drainage piping structure according to this embodiment, the call pipe can be provided with a pair of upper and lower elbow pipes, and the finned joint can be connected directly below the elbow pipe located below.

The lower gutter can be connected to the downspout by combining upper and lower elbow pipes. The lower gutter can be shortened to less than 1m, and the stress generated in the lower gutter can be reduced, so stress concentration in the elbow pipes that make up the lower gutter can be mitigated. This makes it possible to avoid problems such as cracks in the elbow pipes caused by relative movement between the eaves gutter and the downspout due to thermal expansion of the roof or wind pressure during strong winds.

"4" In the rainwater drainage piping structure of this embodiment, it is preferable that the downspout connected below the finned joint has a length of 2000 mm or more.

If the length of the downspout downstream of the finned joint is 2000 mm or more, when a large amount of rainwater drainage flows into the downspout downstream of the finned joint, the weight of the rainwater flowing in the downspout creates a greater force sucking the rainwater upstream of the finned joint into the downspout. This makes it easier to induce the siphon phenomenon. Therefore, a rainwater drainage piping structure that can improve the amount of rainwater drained can be provided.
As mentioned above, by making the length of the nominal gutter 1000 mm or less, the installation position of the finned joint can be raised, making it easier to ensure that the length of the downpipe downstream of the finned joint is 2000 mm or more.
With the above-mentioned configuration, smooth drainage can be achieved without causing excessive pressure loss in the piping.

[5], [6] In the rainwater drainage piping structure according to this embodiment, a configuration having a first pipe between the drainage member and the call gutter described in any one of [1] to [3] can be adopted.

By bending the first pipe, the stress concentration occurring between the first pipe and the pipe can be alleviated, and the stress concentration occurring at the connection between the pipe and the downpipe can also be alleviated. This reduces the risk of cracks occurring at both the connection with the drainage member and the connection with the downpipe.

[7], [8] In the rainwater drainage piping structure of this embodiment, a configuration having an extension tube portion at the bottom of the drainage member described in any one of [1] to [3] can be adopted.

By bending the extension tube, stress concentration occurring between the extension tube and the gate can be alleviated, and stress concentration occurring at the connection between the gate and the downpipe can also be alleviated. This reduces the risk of cracks occurring at both the connection with the drainage member and the connection with the downpipe.

In the rainwater drainage piping structure according to the present invention, the use of a finned joint makes it easier to temporarily form a rainwater puddle on the upstream side of the finned joint. This temporary rainwater puddle can suppress the intake of air at the opening side of the drainage member and suppress the generation of vortexes. This effectively induces a siphon effect in the pipe, improving the drainage performance.
In addition, rainwater passing through the flow path of the finned joint attempts to swirl as it passes, but this is straightened by the fins extending along the pipe axis, so that it is drained smoothly after passing through the fins.
In addition, the improved drainage performance allows the length of the drain to be shortened to 1,000 mm or less.
By shortening the length of the nominal gutter, the amount of resin that makes up the nominal gutter can be reduced, and the stress generated in the nominal gutter and the stress generated in the nominal gutter and its connection part can also be reduced.
The above-mentioned structure can reduce stress concentration on the lower gutter and its connection when the drainage member and the downspout move relative to each other due to thermal expansion of the roof or wind pressure during strong winds, thus eliminating the risk of cracks occurring in the lower gutter and its connection.

1 is a partial cross-sectional view showing a rainwater drainage piping structure provided with a drainage member according to a first embodiment of the present invention. FIG. 2 is an exploded view of the drainage member according to the first embodiment. FIG. 4 is a cross-sectional view showing a portion of the drainage member according to the first embodiment. FIG. 2 is a partial cross-sectional perspective view showing a finned joint that can be applied to the rainwater drainage piping structure according to the first embodiment. FIG. 11 is a partial cross-sectional view showing a first example of a conventional drainage member and rainwater drainage piping structure. FIG. 11 is a partial cross-sectional view showing a second example of a conventional drainage member and rainwater drainage piping structure. FIG. 11 is a partial cross-sectional view showing a third example of a conventional drainage member and rainwater drainage piping structure. FIG. 11 is a partial cross-sectional view showing a fourth example of a conventional drainage member and rainwater drainage piping structure. FIG. 6 is a partial cross-sectional view showing a rainwater drainage piping structure provided with a drainage member according to a second embodiment of the present invention. FIG. 6 is a cross-sectional view showing a main part of the rainwater drainage piping structure of the second embodiment. FIG. 11 is a partial cross-sectional view showing a rainwater drainage piping structure provided with a drainage member according to a third embodiment of the present invention. FIG. 11 is a cross-sectional view showing a main part of the rainwater drainage piping structure of the third embodiment. FIG. 11 is a partial cross-sectional view showing a rainwater drainage piping structure provided with a drainage member according to a fourth embodiment of the present invention. FIG. 4 is a cross-sectional view showing a first modified example of an elbow pipe that can be used as the drainage member according to the present invention. FIG. 11 is a cross-sectional view showing a second modified example of an elbow pipe that can be used as the drainage member according to the present invention. FIG. 13 is a cross-sectional view showing a third modified example of an elbow pipe that can be applied to the drainage member according to the present invention. FIG. 13 is a cross-sectional view showing a fourth modified example of an elbow pipe that can be applied to the drainage member according to the present invention. FIG. 11 is a cross-sectional view showing a first modified example of a drain member applicable to the drainage member according to the present invention. FIG. 11 is a cross-sectional view showing a second modified example of a drain member applicable to the drainage member according to the present invention. FIG. 11 is a cross-sectional view showing a third modified example of a drain member applicable to the drainage member according to the present invention. FIG. 13 is a perspective view showing a fourth modified example of a drain member applicable to the drainage member according to the present invention. 1 is a partial cross-sectional view showing a rainwater drainage piping structure provided with a drainage member of a first embodiment according to the present invention and provided with an expansion joint between the drain member and an elbow pipe. 1 is a partial cross-sectional view showing a rainwater drainage piping structure provided with a drainage member according to a first embodiment of the present invention and an expansion joint at a lower portion of an elbow pipe. FIG. 13 is a partial cross-sectional view showing a rainwater drainage piping structure provided with a drainage member according to a fifth embodiment of the present invention. 13A and 13B show a fifth modified example of a drain member applicable to the drainage member according to the present invention, in which FIG. 13A and 13B show a sixth modified example of a drain member applicable to the drainage member according to the present invention, in which (A) is a cross-sectional view and (B) is a plan view. 11A and 11B show other modified examples of the drain member applicable to the drainage member of the present invention, where (A) is a plan view of the seventh modified example, (B) is a plan view of the eighth modified example, (C) is a plan view of the ninth modified example, (D) is a plan view of the tenth modified example, and (E) is a plan view of the eleventh modified example.

"First embodiment"
Hereinafter, with reference to Figs. 1 to 3, an example in which a drainage member according to a first embodiment of the present invention is applied to a rainwater drainage piping structure for an eaves gutter will be described.
The drainage member according to this embodiment is applied to a rainwater drainage piping structure of an eaves gutter attached to the eaves of a folded-plate roof.
As shown in Figure 1, the folded plate roof 1 is formed on the upper end of the wall 2 of a building and has a structure in which the peaks 3 and valleys 4 made of metal plates are alternately formed in a corrugated shape. Figure 1 is a partial cross-sectional view of the eaves end part and wall 2 of the folded plate roof 1, and a rectangular frame-shaped eaves gutter support 6 is fixed by a plurality of mounting bolts 5 that penetrate the metal plate that constitutes the peaks 3 of the eaves in the vertical direction.
The eaves gutter 7 is suspended and supported by the eaves gutter support 6, and a drain member (drainage member) 8 for guiding rainwater is attached to the bottom of the eaves gutter 7. A downspout 12 is connected to the lower part of this drainage member 8 via a first pipe (connecting pipe) 9 and two upper and lower elbow pipes 10, 11.
The elbow pipes 10, 11 are connected via a pipe 14. A general joint as specified in JIS K6739 or the like can be suitably used for the elbow pipes 10, 11. The portion connecting the upper and lower elbow pipes 10, 11 via the pipe 14 can be called a call pipe YT.
The eaves gutter 7 is supported below the eaves of the folded-plate roof 1, so it can catch rainwater that flows down from the eaves. The downspout 12 is supported vertically by a number of mounting brackets (not shown) attached at several points above and below along the wall 2, and is connected to a drainage channel (not shown) buried in the ground near the building so that rainwater can be drained.
The elbow pipes 10 and 11 used in this embodiment may have an inner wall surface and an outer wall surface with a radius of curvature of 64 mm or less when viewed in a cross section in a plane including the pipe axis. The smaller the radius of curvature of the elbow pipes 10 and 11, the more likely stress is to concentrate, and therefore the effect described later in this embodiment can be easily obtained.

The eaves gutter 7 is supported by the eaves gutter support 6, but the longitudinal ends of the eaves gutter 7 are covered with stoppers, and the eaves gutter system is made up of various parts such as joints and supports that connect the eaves gutter 7 to each other. The eaves gutter support 6 shown in Figure 1 adopts a structure that supports the bottom surface of the eaves gutter 7, but a structure that suspends the side panel 7B of the eaves gutter 7 may also be adopted. The eaves gutter 7 also includes a valley gutter. A drainage system equipped with a downpipe 12 is made up of parts such as joints and supports that connect the downpipes 12 to each other.

The folded plate roof 1 shown in Figure 1 has a slight downward roof slope from right to left, with the left end of the folded plate roof 1 being the eaves edge. The eaves edge extends in the front-to-back direction of the paper in Figure 1, and multiple eaves gutter supports 6 are fixed at predetermined intervals along the extended eaves edge, and these multiple eaves gutter supports 6 support eaves gutters 7. Figure 1 is a partial cross-sectional view showing only a portion of the eaves edge, so only one eaves gutter support 6 and one eaves gutter 7 are drawn.
The eaves gutter 7 is supported by the eaves gutter support 6 and suspended almost horizontally. The eaves gutter 7 is composed of a bottom plate 7A and side plates 7B, 7B formed to rise upward from the left and right ends of the bottom plate 7A shown in Figure 1. The front-to-back direction of the paper in Figure 1 is the length direction of the eaves gutter 7, and the left-to-right direction of the paper in Figure 1 is the width direction of the eaves gutter 7. A through hole 7H for attaching a drainage member 8 is formed in the center of the width direction of the bottom plate 7A. In this embodiment, a drainage channel R is formed inside the eaves gutter 7, defined by the bottom plate 7A and the side plates 7B, 7B. The eaves gutter 7 is formed to run along the eaves edge of the building, so that a drainage channel R running along the eaves edge of the building is formed along the eaves gutter 7.

In this embodiment, the eaves gutter 7 is an extrusion molded product made of synthetic resin such as rigid polyvinyl chloride resin, ABS, AES, etc. The material for forming the eaves gutter 7 can be set arbitrarily and is not limited to synthetic resin, and may be, for example, a metal extrusion molded product.
More specifically, the eaves gutter 7 may be formed of, for example, an olefin resin such as a polyethylene resin or a polypropylene resin, or a thermoplastic polyester resin having excellent heat durability, etc. The eaves gutter 7 may also be configured of a metal plate, and may be formed of, for example, a hot-dip galvanized steel plate, a painted hot-dip galvanized steel plate, a hot-dip zinc or aluminum alloy plated steel plate, a painted hot-dip zinc or aluminum alloy plated steel plate, a hot-dip aluminum plated steel plate, a polyvinyl chloride coated metal plate, a cold-rolled stainless steel plate, a painted stainless steel plate, a titanium plate or titanium alloy plate, a highly weather-resistant rolled steel plate, an asphalt or resin coated steel plate, an aluminum alloy plate, or the like.
The eaves gutter support 6 has, for example, a bottom piece 6A that supports the bottom plate 7A of the eaves gutter 7, side pieces 6B, 6C that extend upward from both ends of the bottom piece 6A, and an upper piece 6D that connects the upper ends of the side pieces 6B, 6C. The eaves gutter support 6 is formed in a frame shape, and is suspended from the folded plate roof 1 by fixing a part of the upper piece 6D to a part of the roof plate with a mounting bolt 5, thereby suspending and supporting the eaves gutter 7.

Furthermore, when the eaves gutter 7 is made of synthetic resin, it is preferable that the linear expansion coefficient is 2.0×10 ^-5 /° C. or less to prevent expansion and contraction due to heat, etc. It is also preferable to reduce the linear expansion coefficient by inserting a low-elasticity sheet such as a stretched PET resin sheet or an iron sheet into the center of the thickness direction of the eaves gutter 7, or by blending a low-elasticity additive such as wollastonite or carbon fiber into the synthetic resin itself that constitutes the eaves gutter 7.
The eaves gutter 7 has a bottom width of 100 mm or more and 300 mm or less, and a height of 90 mm or more and 400 mm or less, and may be applied to a large-diameter eaves gutter that can carry rainwater at a flow rate of, for example, 4 liters/sec or more and 20 liters/sec or less.

As shown in Figures 1 and 2, the drain member (drainage member) 8 includes, for example, a lower drain member 15, an upper drain member 16, and a siphon portion 17 disposed on the upper portion of the upper drain member 16, and is attached to the eaves gutter 7. Specifically, as shown in Figure 2, the lower drain member 15 is disposed on the lower surface 7D side of the bottom plate 7A of the eaves gutter 7, and the upper drain member 16 is disposed on the upper surface 7E side of the bottom plate 7A.

The material for forming the drainage member 8 can be arbitrarily selected.
In this embodiment, the drainage member 8 is an injection molded product made of synthetic resin such as rigid polyvinyl chloride resin, polycarbonate, ABS, AES, etc. The material is not limited to synthetic resin, and the drainage member 8 may be formed by casting cast iron, stainless steel, or aluminum. The drainage member 8 may also be a fireproof double-layer pipe in which an inner pipe of a rigid polyvinyl chloride pipe is covered with an outer pipe of fiber mortar. This fireproof double-layer pipe may also be applied to the downpipe 12 and the call pipe YT.

In this embodiment, a configuration including the drainage member 8 is illustrated, but a configuration may be adopted in which the drainage member 8 is not provided, but instead a connection joint that improves drainage performance in the same way as the drainage member 8, for example a finned joint having a configuration described later, is provided. Specifically, the rainwater drainage piping structure may be configured to include an eaves gutter, a call gutter, a finned joint, and piping.
The finned joint is preferably connected downstream of the elbow pipe 11. It is preferable to attach it within 1000 mm from the elbow pipe 11. The finned joint can improve drainage performance. The connection position of the finned joint may be within 800 mm, 600 mm, 400 mm, 200 mm, etc. from the elbow pipe 11, or it may be directly connected to the elbow pipe 11.

Furthermore, although the present embodiment illustrates a configuration including an eaves gutter 7, a configuration may be adopted in which an eaves gutter 7 is not included and a drainage basin is required.
Specifically, the rainwater drainage piping structure may include a catch basin, a drainage member and/or a finned joint, and a piping. Here, the catch basin is not limited to being made of resin, but may be made of cast iron using a mold or made of SUS (stainless steel plate).

The detailed structures of the lower drain member 15 and the upper drain member 16 will be described later, and the siphon portion 17 will be described first.
2, the siphon portion 17 includes, for example, a cover member 18, a vertical rib 19 connecting the upper drain member 16 and the cover member 18, a gripping rib 20, and an induction guide 21. The siphon portion 17 is integrated with the upper portion of the upper drain member 16.

The cover member 18 is formed, for example, in the shape of a circular disk in a plan view and is disposed above the upper drain member 16. The cover member 18 is also formed in a position coaxial with the tube axis O1 of the upper drain member 16.

Although a disk shape is exemplified for the cover member 18 here, the shape is not limited to this, and a funnel shape such as a funnel-shaped inlet portion 60 in Fig. 19 described later may be used instead. In any case, any shape can be appropriately used as long as it covers part or all of the drop opening portion 22, which is a drainage port, from above.
The lid member 18 can be omitted, but having it installed makes it easier to seal the basin when draining water and makes it easier to induce the siphon effect, thereby improving drainage performance.

As shown in FIG. 2, the portion formed between the outer peripheral edge 18A of the cover member 18 and the outer peripheral edge 31C of the upper flange portion 31 provided on the upper drain member 16 constitutes the inflow opening 23. The inflow opening 23 constitutes an opening through which rainwater accumulated in the eaves gutter 7 flows into the drop opening portion 22 of the upper drain member 16, which will be described later.

The size, height, and shape of the lid member 18 are adjusted so that the area of the inflow opening 23 is larger than the opening area of the drop opening portion 22, which will be described later. In this embodiment, the area of the inflow opening 23 can be calculated by multiplying the circumference of the circular lid member 18, i.e., the length of the outer circumferential edge 18A, by the height H of the lid member 18.
The cover member 18 is supported by the upper drain member 16 while being supported from below by a plurality of vertical ribs 19. As a result, the vertical ribs 19 that are spaced apart from one another are connected by the cover member 18, so that the stress that is unevenly applied to the upper drain member 16 is distributed to the vertical ribs 19 connected to the cover member 18, and the stress that is applied to the inner tube portion 32 and the inner tube reduced diameter portion 33 can be distributed.

The vertical ribs 19 are plate materials fixed at equal angular intervals around the tube axis O1 on the underside of the cover member 18. Although a plate material is exemplified as the vertical ribs 19 here, the present invention is not limited to this, and rod materials (support legs) having a rectangular or circular cross section perpendicular to the longitudinal direction may also be used.
In any case, by providing a plurality of vertical ribs 19, it is possible to remove foreign matter from rainwater that is larger than the interval between adjacent vertical ribs 19. It is also possible to straighten the flow of rainwater that tends to swirl when drained.
2, six vertical ribs 19 are provided, and these six vertical ribs 19 are provided at intervals of about 60 degrees around the tube axis O1. However, the number and arrangement intervals of the vertical ribs 19 are not limited to this example.

The cover member 18 is positioned inside the eaves gutter 7, positioned above and spaced apart from the drop mouth portion 22, and forms an inflow opening 23 that allows rainwater to flow from the upper surface 7E of the eaves gutter 7 into the drop mouth portion 22.
The cover member 18 is preferably set at a height H, for example, of 10 to 60 mm upward from the upper surface 7E of the eaves gutter 7.

The size of the lid member 18 in a plan view can be set arbitrarily, but it is preferable that the lid member 18 is disposed so as to cover the opening of the drop mouth portion 22 in a plan view and is set to be larger than the opening area of the drop mouth portion 22. The size of the lid member 18 may be set to be equal to the opening area of the drop mouth portion 22 or smaller than the opening area.
Furthermore, a through hole may be formed in the cover member 18 in the vertical direction, penetrating from the top surface to the drop opening portion 22 .
The illustrated lid member 18 is positioned so as to completely or partially cover the opening of the drop-off portion 22, but if it is set larger than the opening area of the drop-off portion 22, it will be easier to seal in water, which will more easily induce a siphon effect and is expected to improve drainage performance.

It is preferable that the height H of the cover member 18 is set at a position, for example, 30 to 40 mm above the bottom plate 7A of the eaves gutter 7, and the diameter of the cover member 18 is set to 150 to 200% of the opening outer diameter R1 of the drop-off portion 22.
In order for a stable siphon action to occur, the height of the cover member 18 is preferably 0.1 to 0.5 times the maximum water level in the eaves gutter 7, and more preferably 0.2 to 0.45 times the height.
The maximum water level in the eaves gutter 7 refers to the lowest height from the bottom plate 7A to the side plate 7B of the eaves gutter 7.

The inner diameter of the drop opening 22 for providing the lid member 18 is preferably, for example, 50 mm or more and 170 mm or less, and more preferably 70 mm or more and 170 mm or less. In other words, by setting the inner diameter of the drop opening 22 to the lower limit of 50 mm or more, a large amount of wastewater generated in the siphon portion 17 can be smoothly discharged.
By making the inner diameter of the drop opening portion 22 170 mm or less, the fit is small, preventing the joints and supports from becoming larger.

As shown in FIG. 2, the cover member 18 is provided with gripping ribs 20 that protrude upward from the upper surface 18B and are spaced apart in the circumferential direction. By gripping the gripping ribs 20, it is easy to rotate the drainage member 8 when tightening it.

An induction guide 21 is provided at the center of the underside of the lid member 18. As shown in Fig. 2, the induction guide 21 is provided in the center of the underside of the lid member 18 so that a plurality of induction guides 21 having curves that gradually extend downward toward the drain axis O (the center of the lid) are provided so as to extend radially in the radial direction from the drain axis O.
The guide 21 guides rainwater in the eaves gutter 7 from the inlet opening 23 to the drop opening (the opening of the drop opening 22). In the illustrated example, the guide 21 is integrated with the cover member 18 and constitutes a part of the cover member 18.
In addition, the induction guide 21 may be formed by a funnel-shaped or cylindrical wall portion with holes at the upper and lower ends, and may be provided as a member that constitutes part of the cover member 18 that covers the opening of the drop portion 22.

The siphon section 17 closes the opening of the downspout section 22 when viewed from above, and when a large amount of rainwater flows in from the inlet opening 23 during heavy rain, it does not suck in air and fills the downspout 12 with water to seal it off. As a result, a siphon effect occurs downstream, providing a high drainage function.
Such a drainage member 8 is provided, for example, on the inside of the eaves gutter 7 of a rainwater drainage piping structure installed in a building of a large facility such as a factory or shopping center, and exhibits high drainage performance.

2 and 3, the upper drain member 16 has an upper flange portion 31 disposed on the upper surface of the bottom plate 7A of the eaves gutter 7 and having a drop opening portion 22 formed on its inner periphery, and an inner cylinder portion 32 formed below the upper flange portion 31. The upper drain member 16 further has an inner cylinder reduced diameter portion 33 that connects the upper flange portion 31 and the inner cylinder portion 32 and reduces in diameter downward, and an outer peripheral thread portion 35 formed on the outer periphery of the inner cylinder portion 32.
The inner cylinder portion 32 is inserted into an outer cylinder portion 42 of the lower drain member 15, which will be described later, and the outer peripheral thread portion 35 is screwed into an inner peripheral thread portion 44, which will be described later. By this screwing, the upper drain member 16 and the lower drain member 15 are integrated, and the drainage member 8 is formed.
In the upper drain member 16, the inner surface of the inner cylinder portion 32 and the upper surface of the portion where the upper flange portion 31 is connected are formed into a tapered surface or a curved surface, forming a bell-mouth shape.

The upper flange portion 31 is formed in a ring shape in a plan view.
The lower surface 31B of the upper flange portion 31 is positioned on the upper surface of the bottom plate 7A of the eaves gutter 7.
A flat surface is formed on the outer circumferential side of the lower surface 31B of the upper flange portion 31, and a positioning step portion 36 made of a cylindrical portion protruding downward is formed on the inner circumferential side of the flat surface.
The positioning step portion 36 comes into contact with the inner periphery of the through hole 7H of the eaves gutter 7, so that the upper drain member 16 is positioned relative to the through hole 7H.

As shown in FIG. 3, the lower drain member 15 includes a lower flange portion 41 that is disposed on the lower surface 7D side of the eaves gutter 7, and an outer tube portion 42 that is integrally formed below the lower flange portion 41 and extends downward. The lower drain member 15 further includes an outer tube reduced diameter portion 43 that connects the lower flange portion 41 and the outer tube portion 42, and an inner thread portion 44 formed on the inner surface of the outer tube portion 42.

The length of the outer cylinder portion 42 is, for example, about 40 to 65 mm.
The lower flange portion 41 is formed in a ring shape in a plan view, and has a receiving opening 41H that is circular in a plan view formed on the inner side.
In the lower flange portion 41, a flat surface is formed on an upper surface 41A on the outer circumferential side, and the inner circumferential side is recessed downward from the flat surface.
The upper surface 41A of the lower flange portion 41 is arranged on the lower surface 7D side of the bottom plate 7A of the eaves gutter 7.

The outer tube portion 42 is formed, for example, in a cylindrical shape centered on the tube axis O2, and extends in the vertical direction when attached to the eaves gutter 7.
An outer cylinder inner peripheral hole 42H is formed in the inner side of the outer cylinder portion 42, extending in the vertical direction.
An inner peripheral thread portion 44 is formed on the inner surface of the outer tube portion 42 slightly below the outer tube reduced diameter portion 43 .
An inner peripheral convex stopper 42E is formed on the inner surface of the outer cylindrical portion 42 slightly below the position where the inner peripheral thread portion 44 is formed, and a socket portion 42F is formed on the lower end side of the outer cylindrical portion 42. This socket portion 42F is formed to a size that allows the short tube-shaped first tube 9 provided below the outer cylindrical portion 42 to be inserted therein. The length of the socket portion 42F in the tube axis direction is, for example, about 40 to 65 mm.

The first pipe 9 is, for example, a short tubular injection molded or extrusion molded product made of synthetic resin such as rigid polyvinyl chloride resin, polycarbonate, ABS, AES, etc. The first pipe 9 and the pipe constituting the nominal gutter YT can be appropriately selected from nominal diameters of 75A to 150A as specified in JIS K 6741. The outer diameter is 89.0 mm to 165.0 mm, the inner diameter is 78.0 mm to 154.8 mm, and the opening area is 47.78 ^cm2 to 188.21 ^cm2 .
The length of the first pipe 9 can be, for example, 2000 mm or less, and is preferably 1000 mm or less or less than 600 mm. Also, it is preferably 70 mm or more, and is preferably a length that does not allow the lower end of the outer tube portion 42 to come into contact with the upper end of the receiving portion 10B between the elbows 0, and is more preferably 100 mm or more, and may be 500 mm or more. However, in order to facilitate the occurrence of a siphon phenomenon on the downstream side, the downspout 12 needs to be 2000 mm or more in length, and it is preferable to appropriately cut and adjust the length of the first pipe 9 so that the downspout 12 can be 2000 mm or more.

As shown in Fig. 1, elbow pipes 10 and 11 provided below the first pipe 9 each have a curved pipe and cylindrical sockets formed integrally on both ends of the curved pipe. For example, the elbow pipe 10 has a curved pipe 10A and sockets 10B and 10B. The elbow pipe 11 has a curved pipe 11A and sockets 11B and 11B.
The length of the nominal downpipe YT, which connects the elbow pipes 10 and 11 with the pipe 14, is preferably 1000 mm or less, more preferably 500 mm or less. In this specification, the length of the nominal downpipe YT is defined as the horizontal distance L between the central axis of the first pipe 9 and the central axis of the downpipe 12. This definition is the same in each embodiment described later. If the length of the nominal downpipe YT is 500 mm or less, there is a high possibility that stress concentration on the elbow pipes 10 and 11 will be significant, so this is effective for nominal downpipes YT of 500 mm or less. In that case, stress concentration can be alleviated, and cracks can be better prevented from occurring in the drain members 15 and 16 and the elbow pipes 10 and 11.
The first pipe 9 is short in shape, and its upper end forms a spigot portion 9A that is connected to the socket portion 42F of the outer tube portion 42, and its lower end forms a spigot portion 9B that is connected to the socket portion 10B of the elbow pipe 10.

The depth (depth) of the receiving portions 10B, 11B is, for example, about 40 to 65 mm. In the example shown in Fig. 1, the bending angle of the curved tubes 10A, 11A is 45°. A bending angle of 45° means that the angle between the central axes of the cylindrical receiving portions 10B, 10B is 45°, and that the angle between the central axes of the cylindrical receiving portions 11B, 11B is 45°.
In addition, the elbow pipe 10 is made compact by making the length of the curved pipe as short as possible. For this reason, the end 10B' of one socket 10B located on the inside of the bent portion of the curved pipe 10A and the end 10B' of the other socket 10B are arranged close to each other. Similarly, in the elbow pipe 11, the end 11B' of one socket 11B located on the inside of the bent portion of the curved pipe 11A and the end 11B' of the other socket 11B are arranged close to each other.

The elbow pipes 10, 11 are joined in an S-shape in side view as shown in Figure 1, with the lower end of the first pipe 9 being inserted into the socket 10B of the upper elbow pipe 10. The upper end of the downspout 12 is inserted into the socket 11B of the lower elbow pipe 11. In the structure of this embodiment, gaps are filled in at the connections between the pipes by applying an adhesive or the like.
Since the elbow pipes 10, 11 are joined in an S-shape, the upper end of the downspout 12 supported at a position closer to the wall section 2 can be connected to the first pipe 9 located directly below the eaves gutter 7, thereby forming a compact rainwater drainage piping structure.

In the rainwater drainage piping structure shown in FIG. 1, even if the eaves gutter 7 moves slightly in the left-right direction in FIG. 1 due to thermal contraction of the folded-plate roof 1 or wind pressure during strong winds, the load acting on the joints of the elbow pipes 10 and 11 can be reduced because the first pipe 9 is provided as a separate member from the lower drain member 15 and the downspout 12. By providing the first pipe 9 as a separate member, the number of places where stress is concentrated can be increased, thereby dispersing stress. In addition, the stress concentration is also reduced by the deformation of the first pipe 9 itself. Therefore, the configuration provided with the first pipe 9 can reduce the load acting on the connection parts of the elbow pipes 10 and 11, and has the effect of preventing cracks from occurring at the receiving portions 10B and 11B of the elbow pipes 10 and 11.
Furthermore, the receiving portion 42F of the lower drain member 15 and the receiving portions 10B, 11B of the elbow pipes 10, 11 do not have a special receiving structure, but can have a general receiving structure as appropriate, and there is no need to design and manufacture them as dedicated parts, so the storm water drainage piping structure shown in Figure 1 can be provided at low cost.

In addition, in the rainwater drainage piping structure shown in Figure 1, regarding the relationship between the inner diameter of the nominal pipe including the elbow pipes 10, 11 and pipe 14 and the inner diameter of the downpipe 12, it is preferable that the inner diameter of the nominal pipe is larger than the inner diameter of the downpipe 12.
As an example, the cross-sectional area (opening area) of the downpipe is preferably 2.0 times or more and 7.0 times or less than the cross-sectional area (opening area) of the downpipe 12. In this way, by making the inner diameter of the downpipe 12 smaller than the inner diameter of the downpipe, it is possible to easily fill the inside of the downpipe 12 with wastewater when the wastewater flows down from the downpipe to the downpipe 12. This makes it easier to generate a siphon phenomenon inside the downpipe 12. Therefore, it is possible to increase the amount of wastewater treatment. As a result, it is possible to ensure sufficient drainage capacity even if the downpipe 12 is made thin, and it is possible to prevent a decrease in the appearance of a building equipped with the downpipe 12.

So far, we have used Figures 1 to 3 to explain the rainwater drainage piping structure in which the drainage member is the drainage member 8. However, rather than promoting the occurrence of the siphoning phenomenon in the drainage member 8, it is also possible to adopt a structure in which the drainage member 8 is structured simply for the purpose of preventing the intrusion of foreign matter, etc., and a drainage member that promotes the occurrence of the siphoning phenomenon is placed on the downspout 12 side.

Fig. 4 shows a finned joint as a suitable drainage member for installation on the upright pipe side. When this finned joint is installed, the drainage member 8 installed on the eaves gutter side may be omitted, or the drainage member 8 may be installed on top of the finned joint.
The finned joint (first joint) 70E has a joint body 80E and a plurality of fins 90E.
The fitting body 80E has a straight pipe section 83 which is a cylindrical pipe having a pipe axis along the vertical direction, an inlet side joint section 81 formed integrally with the upper end of the straight pipe section 83, and an outlet side joint section 82E which is coaxially connected to the lower end of the straight pipe section 83.
As an example, when the downspout 12 is formed by joining a plurality of pipes, the finned joint 70E is incorporated into a pipe midway through the downspout 12 by utilizing the inlet side joint 81 and the outlet side joint 82E. Alternatively, the finned joint 70E is incorporated directly below the elbow pipe 11, between the elbow pipe 11 and the downspout 12.

A finned ring 90E1 having a plurality of fins 90E formed on its inner circumferential surface is integrally connected to the outlet side mating portion 82E via a connecting portion 90E2.
The finned ring 90E1 has an upstream edge 90E1a located relatively upstream, a downstream edge 90E1b located relatively downstream, a contraction section 90E1c connecting the upstream edge 90E1a and the downstream edge 90E1b, and a plurality of fins 90E arranged at equal angular intervals circumferentially around the pipe axis on the inner surface of the contraction section 90E1c.

The upstream edge 90E1a and the downstream edge 90E1b are both annular flange portions, and have an outer diameter close to the inner diameter of the inner circumferential surface of the straight pipe section 83. Therefore, the upstream edge 90E1a and the downstream edge 90E1b can contact the inner wall surface 83a of the straight pipe section 83 without leaving a gap. When viewed in a cross section including the pipe axis, the inner circumferential surface of the upstream edge 90E1a is gradually thicker from the upstream side toward the downstream side. Therefore, although the upstream edge 90E1a is inserted into the inner wall surface 83a, it does not create an excessively large step with respect to the inner circumferential surface of the straight pipe section 83, allowing the flow of rainwater passing through here to pass smoothly without disturbance.

The downstream edge 90E1b is smoothly connected to the upper end of the connection portion 90E2 without creating an excessively large step. Therefore, the downstream edge 90E1b rectifies the flow of rainwater by allowing it to pass through smoothly without disturbing the flow of rainwater passing through it. In addition, the downstream edge 90E1b forms an annular gap with the inner peripheral surface of the outlet side fitting portion 82E, and the lower end of the straight pipe portion 83 is fitted watertightly into this annular gap.

The contraction section 90E1c has an arch-like shape when viewed in a cross section including the tube axis, with the upper half from the upstream side to a midway point in the tube axis direction forming a contraction flow path, and the lower half from the midway point toward the downstream side in the tube axis direction forming an expansion flow path. That is, in the upper half, the inner diameter of the circular opening viewed from the direction along the tube axis gradually decreases from the upstream side to the downstream side, and reaches a minimum inner diameter at the boundary with the lower half. Then, in the subsequent lower half, the inner diameter of the circular opening viewed from the direction along the tube axis gradually increases from the minimum inner diameter as it moves from the upstream side to the downstream side, and becomes equal to the inner diameter of the connection section 90E2 at the boundary with the connection section 90E2.

Each fin 90E is a substantially linear projection having an upper end 90Ea located at the most upstream side in the tube axis direction and a lower end 90Eb located at the most downstream side in the tube axis direction. In this example, when viewed along the tube axis direction, the lower end 90Eb is located at a position slightly shifted laterally from directly below the upper end 90Ea. Therefore, each fin 90E is tilted so that a straight line connecting the upper end 90Ea and the lower end 90Eb intersects with the tube axis when it is superimposed. Then, between adjacent fins 90E, a tilted flow path is formed along a direction that intersects with the tube axis when it is superimposed.

When viewed in a cross section perpendicular to a line connecting the upper end 90Ea and the lower end 90Eb, each fin 90E has a substantially triangular cross-sectional shape at each position on the line. The height of the triangular cross section gradually increases from the upper end 90Ea to the center of the line, and then gradually decreases from the center of the line to the lower end 90Eb. In addition, the width dimension when these fins 90E are viewed opposite each other gradually increases from the upper end 90Ea to the center of the line, and then gradually narrows from the center of the line to the lower end 90Eb. In other words, each fin 90E is thickest at the center in the tube axis direction, and gradually becomes thinner from this center toward the upper end 90Ea. Similarly, each fin 90E gradually becomes thinner from the center toward the lower end 90Eb. Furthermore, when each fin 90E is viewed in a cross section including a straight line connecting the upper end 90Ea and the lower end 90Eb and along the thickness direction of the wall portion of the contraction section 90E1c, it forms a convex arch shape that conforms to the inner surface of the contraction section 90E1c.
Since each fin 90E has the above-mentioned shape, it is possible to gradually increase the flow resistance applied to rainwater along the tube axis direction.

According to the configuration described above, when rainwater passes through each of the fins 90E and the finned ring 90E1, both flow contraction and flow straightening occur simultaneously, and the rainwater is smoothly drained away.
In addition, it is preferable that each fin 90E is arranged so that the upper end 90Ea of each fin 90E is located within 1000 mm vertically downward from the lower end of the receiving portion 11B of the elbow pipe 11. As a result, rainwater flowing into the finned joint 70E begins to experience flow resistance caused by hitting each fin 90E and resistance caused by the contraction formed by the inner circumferential surface of the contraction portion 90E1c. This flow resistance creates a braking effect that reduces the flow speed of the rainwater that has flowed in, as in the first embodiment. Also, each fin 90E similarly provides a straightening effect.

Therefore, according to the configuration of this example, rainwater with a reduced flow rate temporarily accumulates in the flow path between the upper side of each fin 90E and the elbow pipe 11, making it difficult for air to enter the rainwater flowing from the drainage member 8 into the elbow pipe 11, making it possible to reliably induce the siphon effect. Moreover, since the rainwater has already been straightened after passing through each fin 90E, it is drained smoothly without swirling.

In addition, the finned ring 90E1 on which each fin 90E is formed is integrated with the outlet side fitting portion 82E and a socket-type structure is adopted in which it is coaxially fitted into the lower end of the straight pipe portion 83, making it possible to easily install and replace each fin 90E, as well as to perform maintenance such as cleaning.
The socket-type configuration including the fins 90E and the finned ring 90E1 according to this modified example may be applied to each of the embodiments described below.
In the first embodiment described based on Figures 1 to 3, a rainwater drainage piping structure including the eaves gutter 7 has been described, but a rainwater drainage piping structure that does not include the eaves gutter 7 but requires a drain basin may also be used. Specifically, a rainwater drainage piping structure including a drain basin, a finned joint 70E, a referral gutter, and a downspout 12 may also be used.

The rainwater drainage piping structure equipped with the finned joint 70E shown in Fig. 4 can easily form a temporary rainwater puddle upstream of the finned joint 70E. This temporary rainwater puddle can suppress the intake of air upstream of the finned joint 70E and suppress the generation of vortexes. This effectively creates a siphon effect in the pipe, improving drainage performance.
Rainwater passing through the flow path of the finned fitting 70E attempts to swirl as it passes through, but this is straightened by multiple fins 90E extending along the pipe axis, and is then drained smoothly after passing through the position of the fins 90E.

When the finned joint 70E shown in FIG. 4 is provided, it is preferable that the downspout 12 below the position where the finned joint 70E is provided has a length of 3000 mm or more.
If the downspout 12 downstream of the finned joint 70E has a length of 3000 mm or more, when a large amount of rainwater drainage flows into the downspout 12 downstream of the finned joint 70E, the weight of the rainwater flowing in the downspout 12 creates a greater force sucking the rainwater upstream of the finned joint 70E into the downspout. This makes it easier to induce the siphon phenomenon. Therefore, a rainwater drainage piping structure that can improve the amount of rainwater drained can be provided.
As mentioned above, by setting the length of the first pipe 9 to, for example, 2000 mm or less, 1000 mm or less, or less than 600 mm, the installation position of the finned joint 70E can be raised, making it easier to ensure that the length of the downspout 12 downstream of the finned joint 70E is 3000 mm or more.
The distance between the elbow pipe 11 and the finned joint 70E is preferably within 1000 mm from the lower end of the elbow pipe 11. The finned joint can improve drainage performance. The position of the finned joint may be within 800 mm, 600 mm, 400 mm, 200 mm, etc. from the lower end of the elbow pipe 11. The distance between the elbow pipe 11 and the finned joint 70E is preferably 70 mm or more, and is preferably a distance that does not allow the lower end of the outer tube portion 42 and the upper end of the receiving portion 10B of the elbow pipe 10 to come into contact with each other, more preferably 100 mm or more, and may be 500 mm or more.
With the above-mentioned configuration, smooth drainage can be achieved without causing excessive pressure loss in the piping.

"Conventional storm water drainage piping structure"
FIG. 5 shows a conventional rainwater drainage piping structure in which a spigot 8A is formed at the lower end of a drainage member 8 attached to an eaves gutter 7, this spigot 8A is directly connected to an elbow pipe 50, the other end of which is connected to a call pipe 34 consisting of a horizontal pipe, and the other end of the call pipe 34 is connected to a downpipe 12 via an elbow pipe 51.
The elbow pipe 50 has a curved pipe 50A and sockets 50B, 50B provided on both ends thereof, and the elbow pipe 51 has a curved pipe 51A and sockets 51B, 51B provided on both ends thereof. In the elbow pipe 50, the inclination angle between the central axis of one socket 50B and the central axis of the other socket 50B is set to 90°. In the elbow pipe 51, the inclination angle between the central axis of one socket 51B and the central axis of the other socket 51B is set to 90°. The elbow pipes 50, 51 are long elbow type elbow pipes in which the curved pipes 50A, 51A are slightly longer than the previous elbow pipes 10, 11.
In the case of the rainwater drainage piping structure shown in FIG. 5, the eaves gutter 7 cannot be connected unless it is spaced from the wall by the length of the call gutter 34, and there is a problem in that the piping does not fit snugly.

In a structure in which an eaves gutter 7 is provided on a folded plate roof 1, in order to attach a drainage member 8 having a spigot portion 8A to the eaves gutter 7 and connect the drainage member 8 to a downspout 12, it is possible to adopt, as another example, the rainwater drainage piping structure shown in Figure 6.
In the rainwater drainage piping structure shown in FIG. 6, long elbow type elbow pipes 50, 51 connected in an S-shape are connected to a spigot 8A, and the upper end of a downspout 12 is connected to a receiving portion 51B of the elbow pipe 51.

In the rainwater drainage piping structure shown in Figure 6, the arc length of the central axis of the elbow pipes 50, 51 is set to be larger than that of the elbow pipes 10, 11 described previously. Therefore, even if there is some movement of the eaves gutter 7 due to thermal expansion of the corrugated roof 1 or wind pressure, stress can be dispersed, and the elbow pipes 50, 51 can be made less susceptible to cracking.
However, in the configuration of Figure 6, the horizontal dimension a of the rainwater drainage piping structure from the drainage member 8 to the downspout 12 becomes large by the amount of the elbow pipes 50, 51 that are formed to be long, which causes a problem of poor fit as a rainwater drainage piping structure.

In a structure in which a eaves gutter 7 is provided on a folded-plate roof 1, a drainage member 8 with a spigot 8A is attached to the eaves gutter 7, and the drainage member 8 is connected to a downpipe 12. As another example, the rainwater drainage piping structure shown in FIG. 7 can be used.

Figure 7 shows a rainwater drainage piping structure in which a spigot 8A is formed at the lower end of a drainage member 8 attached to an eaves gutter 7, this spigot 8A is directly connected to an elbow pipe 10, a call pipe 52 consisting of a short pipe arranged diagonally is connected to the other end of the elbow pipe 10, and the other end of the call pipe 52 is connected to a downpipe 12 via an elbow pipe 11.
In the rainwater drainage piping structure shown in Figure 7, a call gutter 52 is provided, so even if there is some movement of the eaves gutter 7 due to thermal expansion of the corrugated roof 1 or wind pressure during strong winds, it is expected that stress can be dispersed, and the structure can be made less likely to crack the elbow pipes 10 and 11.
However, in the configuration of Figure 7, the horizontal dimension b of the rainwater drainage piping structure from the drainage member 8 to the downspout 12 becomes larger by the amount of the lead pipe 52 provided, which causes a problem of poor fit as a rainwater drainage piping structure.

Figure 8 shows a rainwater drainage piping structure in which a spigot 8A is formed at the lower end of a drainage member 8 attached to an eaves gutter 7, this spigot 8A is directly connected to an elbow pipe 10, and the other end of the elbow pipe 10 is connected to a downspout 12 via an elbow pipe 11.
In the rainwater drainage piping structure shown in Figure 8, the elbow pipes 10, 11, which have a small radius of curvature, are directly connected, so that the horizontal dimension c of the rainwater drainage piping structure can be made small. However, if the eaves gutter 7 moves due to thermal expansion of the folded-plate roof 1 or wind pressure during strong winds, stress cannot be dispersed, and there is a risk of cracks occurring at the connection between the elbow pipes 10, 11.
In contrast, the rainwater drainage piping structure shown in Figures 1 to 3 described above has a compact configuration in which the piping connections fit snugly, and it is possible to provide a rainwater drainage piping structure in which no cracks occur in the elbow pipes 10, 11 even if the eaves gutter 7 moves slightly due to thermal expansion or wind pressure during strong winds.

Second Embodiment
FIG. 9 is an overall configuration diagram showing a rainwater drainage piping structure for an eaves gutter equipped with a drainage member according to a second embodiment of the present invention, and FIG. 10 is a cross-sectional view of a main portion.
In the second embodiment, the configuration in which the eaves gutter 7 is supported by the eaves gutter support 6 on the folded plate roof 1 is equivalent to the configuration in the first embodiment, and the configuration in which the upper drain member 16 and the lower drain member 15 are attached to the eaves gutter 7 is also equivalent to the configuration in the first embodiment. The configuration in which the downspout 12 is connected to the lower drain member 15 via the first pipe 45, elbow pipes 10, 11, and pipe 14 is also equivalent. In this embodiment, a drainage channel R defined by the bottom plate 7A and the side plates 7B, 7B is formed inside the eaves gutter 7. The eaves gutter 7 is formed to follow the eaves of the building, so that the drainage channel R along the eaves of the building is formed along the eaves gutter 7.
The configuration of the second embodiment differs from that of the first embodiment mainly in that a spigot portion is formed at the lower end of the outer tube portion 42 provided on the lower drain member 15, and in that the configuration of the first pipe 45 interposed between the lower drain member 15 and the elbow pipe 10 is different.

The upper drain member 16 of this embodiment has a plurality of vertical ribs 48 formed around the inner periphery on the upper inner surface side of the drop opening portion 22 .
In the lower drain member 15 of this embodiment, the outer tubular portion 42 is formed to a length that extends slightly downward beyond the inner tubular portion 32 of the upper drain member 16, and the outer diameter of the outer tubular portion 42 is slightly narrowed from the lower end of the outer tubular reduced diameter portion 43 via a peripheral step portion 46 slightly below the outer tubular portion 43. The outer tubular portion 42 of this embodiment also serves as a spigot portion 47.

The first pipe 45 of this embodiment has a cylindrical socket portion 45A at its upper side to which the spigot portion 47 of the outer tube portion 42 can be connected, and a cylindrical socket portion 45B at its lower side to which the spigot portion 10B of the elbow pipe 10 can be connected. The length of the spigot portion 45B in the pipe axial direction is slightly longer than the length of the spigot portion 45A in the pipe axial direction. A peripheral step portion 45C is formed at the boundary between the socket portion 45A and the spigot portion 45B.
The length (depth in the tube axis direction) of the outer cylinder portion 42 (spigot portion 47) is, for example, about 40 to 65 mm.
The length of the spigot 45B is slightly longer than the axial length (40 to 65 mm) of the socket 10B of the elbow pipe 10. The length of the spigot 45B may be 100 mm or more. The other configurations are the same as those of the first embodiment.

In the structure of the second embodiment, the outer tube portion 42 (spout portion 47) of the lower drain member 15 is connected to the receiving portion 45A of the first pipe 45, and the spout portion 47 of the first pipe 45 is connected to the receiving portion 10B of the elbow pipe 10.
The configuration in which the elbow pipe 11 and the downspout 12 are connected to the elbow pipe 10 is the same as the configuration in the first embodiment.

The length of the first pipe 45 (effectively the length of the spigot 45B in the structure shown in FIG. 10) can be, for example, 2000 mm or less, and is preferably 1000 mm or less or less than 600 mm. It is also preferably 70 mm or more, and is preferably at least a length that does not allow the lower end of the outer tube 42 and the upper end of the receiving portion 10B of the elbow pipe 10 to come into contact with each other, more preferably 100 mm or more, and may be 500 mm or more. However, in order to facilitate the occurrence of a siphon phenomenon on the downstream side, the downspout 12 needs to be at least 2000 mm long, more preferably at least 3000 mm long, and it is preferable to adjust the length of the first pipe 45 by cutting it appropriately so that the downspout 12 can be at least 2000 mm long.

The rainwater drainage piping structure for an eaves gutter according to the second embodiment shown in Figs. 9 and 10 can obtain the same effects as those of the first embodiment.
For example, since the elbow pipes 10, 11, which are shortened versions of the curved pipes 10A, 11A, are joined in an S-shape, the upper end of the downspout 12, which is supported at a position close to the wall section 2, can be connected to the first pipe 45 located directly below the eaves gutter 7, thereby forming a compact rainwater drainage piping structure.

9 and 10, even if the eaves gutter 7 moves slightly in the left-right direction in FIG. 8 due to thermal contraction of the folded-plate roof 1 or wind pressure during strong winds, the first pipe 45 is provided as a separate member for the lower drain member 15 and the downspout 12, so the load acting on the joints of the elbow pipes 10, 11 can be reduced. Therefore, the configuration provided with the first pipe 45 can reduce the load acting on the connection parts of the elbow pipes 10, 11, and has the effect of preventing cracks from occurring in the receiving portions 10B, 11B of the elbow pipes 10, 11.
In addition, since the first tube 45 has a receiving portion 45A on the upper side and a spigot portion 45B on the lower side, it is a dedicated part. However, since the structure is simple, the increase in parts costs can be suppressed as much as possible.

In the second embodiment described based on Figures 9 and 10, a configuration including the drainage member 8 is exemplified, but a configuration not including the drainage member 8 but including the finned joint 70E shown in Figure 4 may be adopted. Specifically, the rainwater drainage piping structure may include the eaves gutter 7, the finned joint 70E, a lower gutter, and a downpipe 12. It is preferable to provide a drainage member at the position where the drainage member 8 is provided in the eaves gutter 7 for the sole purpose of preventing the intrusion of foreign matter.
In the second embodiment described based on Fig. 9 and Fig. 10, a rainwater drainage piping structure including the eaves gutter 7 has been described, but a rainwater drainage piping structure that does not include the eaves gutter 7 but requires a drain basin may also be used. Specifically, a configuration including a drain basin, a finned joint 70E, a lower gutter, and a downspout 12 may also be used. The drain basin is not limited to being made of resin, but may be made of cast iron using a mold or SUS.

"Third embodiment"
FIG. 11 is an overall configuration diagram showing a rainwater drainage piping structure for an eaves gutter equipped with a drainage member according to a third embodiment of the present invention, and FIG. 12 is a partial cross-sectional view.
In the third embodiment, the configuration in which the eaves gutter 7 is supported by the eaves gutter support 6 on the folded plate roof 1 is equivalent to the configuration in the first embodiment, and the configuration in which the upper drain member 16 and the lower drain member 15 are attached to the eaves gutter 7 is also equivalent to the configuration in the first embodiment. Also, the configuration in which the downspout 12 is connected to the lower drain member 15 via the first pipe and elbow pipes 10 and 11 is also equivalent. In this embodiment, a drainage channel R defined by the bottom plate 7A and the side plates 7B and 7B is formed inside the eaves gutter 7. The eaves gutter 7 is formed so as to follow the eaves edge of the building, so that the drainage channel R along the eaves edge of the building is formed along the eaves gutter 7.
The configuration of the third embodiment differs from that of the first embodiment mainly in that a spigot portion is formed at the lower end of the outer tube portion 42 provided on the lower drain member 15, and that a coupling pipe 53 and a first pipe 54 are provided between the lower drain member 15 and the elbow pipe 10.

As shown in FIG. 12 , the upper drain member 16 of this embodiment has a plurality of vertical ribs 48 formed around the inner periphery on the inner surface side of the upper portion of the drop opening portion 22 .
In the lower drain member 15 of this embodiment, the outer tubular portion 42 is formed to a length that extends slightly downward beyond the inner tubular portion 32 of the upper drain member 16, and the outer diameter of the outer tubular portion 42 is slightly narrowed from the lower end of the outer tubular reduced diameter portion 43 via a peripheral step portion 46 slightly below the outer tubular portion 43. The outer tubular portion 42 of this embodiment also serves as a spigot portion 47.

The joint pipe 53 according to this embodiment has a socket portion (outer tube socket portion) 53A on the upper side to which the spigot portion 47 of the outer tube portion 42 can be connected, and a socket portion (first pipe socket portion) 53B on the lower side to which a short-tube-shaped first pipe 54 can be connected. The length of the socket portions 53A and 53B in the pipe axial direction is, for example, about 45 to 60 mm.
The upper end of a short-tube-shaped first pipe 54 is connected to the socket portion 53B of the joint pipe 53, and the lower end of the first pipe 54 is connected to the socket portion 10B of the elbow pipe 10 below it.
The length of the first tube 54 in the tube axis direction is, for example, about 80 to 105 mm, but may be 105 mm or more.
The length of the first pipe 54 in the pipe axis direction can be, for example, 2000 mm or less, and is preferably 1000 mm or less or less than 600 mm. Also, it is preferably 70 mm or more, and is preferably a length that does not allow the lower end of the outer tube portion 42 and the upper end of the receiving portion 10B of the elbow pipe 10 to come into contact with each other, more preferably 100 mm or more, and may be 500 mm or more. However, in order to easily generate a siphon phenomenon on the downstream side, the downspout 12 needs to be 2000 mm or more in length, more preferably 3000 mm or more in length, and it is preferable to appropriately cut and adjust the length of the first pipe 54 so that the downspout 12 can be 2000 mm or more.
The length in the pipe axial direction of the socket 10B of the elbow pipe 10 is, for example, about 40 to 65 mm. The length of the upper side of the first pipe 54 protruding upward from the socket 10B of the elbow pipe 10 is preferably 40 mm or more.
The configuration in which the elbow pipe 11 and the downspout 12 are connected to the elbow pipe 10 is the same as the configuration in the first embodiment.

The rainwater drainage piping structure shown in Figs. 11 and 12 can obtain the same effects as those of the first embodiment.
For example, since the short elbow pipes 10, 11 are joined in an S-shape, the upper end of the downspout 12 supported at a position close to the wall portion 2 can be connected to the joint pipe 53 and the first pipe 54 located directly below the eaves gutter 7, thereby forming a compact rainwater drainage piping structure.

11 and 12, even if the eaves gutter 7 moves slightly in the left-right direction in FIG. 11 due to thermal contraction of the folded-plate roof 1 or wind pressure during strong winds, the joint pipe 53 and the first pipe 54 are provided as separate members for the lower drain member 15 and the downspout 12, so the load acting on the joint of the elbow pipes 10, 11 can be reduced. Therefore, the configuration provided with the joint pipe 53 and the first pipe 54 can reduce the load acting on the connection part of the elbow pipes 10, 11, and has the effect of preventing cracks from occurring in the receiving portions 10B, 11B of the elbow pipes 10, 11.
Furthermore, since the joint pipe 53 and the first pipe 54 have a simple structure, increases in parts costs can be suppressed as much as possible.

In the third embodiment described based on Figures 11 and 12, a configuration including the drainage member 8 is exemplified, but a configuration not including the drainage member 8 but including the finned joint 70E shown in Figure 4 may be adopted. Specifically, the rainwater drainage piping structure may include the eaves gutter 7, the finned joint 70E, a lower gutter, and a downpipe 12. It is preferable to provide a drainage member at the position where the drainage member 8 is provided in the eaves gutter 7 for the sole purpose of preventing the intrusion of foreign matter.
In the third embodiment described based on Fig. 11 and Fig. 12, a rainwater drainage piping structure including the eaves gutter 7 has been described, but a rainwater drainage piping structure that does not include the eaves gutter 7 but requires a drainage basin may also be used. Specifically, a configuration including a drainage basin, a finned joint 70E, a lower gutter, and a downspout 12 may also be used. The drainage basin is not limited to being made of resin, but may be made of cast iron using a mold or SUS.

"Fourth embodiment"
FIG. 13 is an overall configuration diagram showing a rainwater drainage piping structure for an eaves gutter equipped with a drainage member according to a fourth embodiment of the present invention.
In the fourth embodiment, the configuration in which the eaves gutter 7 is supported by the eaves gutter support 6 on the folded plate roof 1 is equivalent to the configuration in the first embodiment, and the configuration in which the upper drain member 16 and the lower drain member 15 are attached to the eaves gutter 7 is also equivalent to the configuration in the first embodiment. Also, the configuration in which the downspout 12 is connected to the lower drain member 15 via the first pipe and elbow pipes 10 and 11 is also equivalent. In this embodiment, a drainage channel R defined by the bottom plate 7A and the side plates 7B and 7B is formed inside the eaves gutter 7. The eaves gutter 7 is formed to follow the eaves of the building, so that the drainage channel R along the eaves of the building is formed along the eaves gutter 7.

The configuration of the fourth embodiment differs from that of the first embodiment mainly in that an extension tube portion 55 constituting a spigot portion is integrally formed at the lower end of the outer tube portion 42 provided on the lower drain member 15.
The extension tube portion 55 has a length of, for example, about 80 to 120 mm. The extension tube portion 55 has a spigot portion at its tip, which is directly connected to the socket portion 10B of the elbow pipe 10.
The length of the extension tube portion 55 in the pipe axis direction can be, for example, 2000 mm or less, and is preferably 1000 mm or less or less than 600 mm. Also, it is preferably 70 mm or more, and is preferably a length that does not allow the lower end of the outer tube portion 42 and the upper end of the receiving portion 10B of the elbow pipe 10 to come into contact with each other, more preferably 100 mm or more, and may be 500 mm or more. However, in order to easily generate a siphon phenomenon on the downstream side, the downspout 12 needs to be 2000 mm or more in length, more preferably 3000 mm or more in length, and it is preferable to adjust the length of the extension tube portion 55 by appropriately cutting it so that the downspout 12 can be 2000 mm or more.

In the structure of the fourth embodiment, since the extension tubular portion 55 is provided at the lower end of the lower drain member 15, the presence of the extension tubular portion 55 provides the same effects as those of the structure of the first embodiment.
For example, since the short elbow pipes 10, 11 are joined in an S-shape, the upper end of the downspout 12 supported at a position close to the wall section 2 can be connected to the extension tube section 55 located directly below the eaves gutter 7, thereby forming a compact rainwater drainage piping structure.

In the rainwater drainage piping structure shown in Fig. 13, even if the eaves gutter 7 moves slightly to the left and right in Fig. 13 due to thermal contraction of the folded-plate roof 1 or wind pressure during strong winds, the extension tube portion 55 that is long relative to the lower drain member 15 and the downpipe 12 can reduce the load acting on the joints of the elbow pipes 10, 11. Therefore, the configuration that includes the extension tube portion 55 can reduce the load acting on the connection parts of the elbow pipes 10, 11, and has the effect of preventing cracks from occurring in the receiving portions 10B, 11B of the elbow pipes 10, 11.
Although the lower drain member 15 provided with the extension tubular portion 55 is a dedicated part, the structure is simple, and therefore an increase in parts costs can be suppressed.

In the fourth embodiment described based on Fig. 13, a configuration including the drainage member 8 is exemplified, but a configuration not including the drainage member 8 but including the finned joint 70E shown in Fig. 4 may be adopted. Specifically, the rainwater drainage piping structure may include the eaves gutter 7, the finned joint 70E, a lower gutter, and a downpipe 12. It is preferable to provide a drainage member at the position where the drainage member 8 is provided in the eaves gutter 7 for the sole purpose of preventing the intrusion of foreign matter.
In the second embodiment described based on Fig. 9 and Fig. 10, a rainwater drainage piping structure including the eaves gutter 7 has been described, but a rainwater drainage piping structure that does not include the eaves gutter 7 but requires a drain basin may also be used. Specifically, a configuration including a drain basin, a finned joint 70E, a lower gutter, and a downspout 12 may also be used. The drain basin is not limited to being made of resin, but may be made of cast iron using a mold or SUS.

In the rainwater drainage piping structures of the first to third embodiments explained based on Figs. 1 to 12, elbow pipes 10, 11 each having a curved pipe 10A with a bend angle of 45° are used.
The elbow pipe applied to the storm water drainage piping structure of the present invention is not limited to an elbow pipe with a bend angle of 45°. It is also possible to use an elbow pipe 56 having a curved pipe 56A with a bend angle of 11° and receiving portions 56B, 56B on both ends as shown in FIG. 14, or an elbow pipe 57 having a curved pipe 57A with a bend angle of 22° and receiving portions 57B, 57B on both ends as shown in FIG. 15.
As an elbow pipe to be applied to the rainwater drainage piping structure of the present invention, an elbow pipe 58 having a curved pipe 58A with a bend angle of 30° and receiving portions 58B, 58B on both ends as shown in Figure 16 may be used, or an elbow pipe 59 having a curved pipe 59A with a bend angle of 60° and receiving portions 59B, 59B on both ends as shown in Figure 17 may be used.
When an elbow pipe is applied to the present invention, if the elbow pipe has a small bend angle, the rainwater drainage piping structure will fit well.

In the rainwater drainage piping structures of the first to third embodiments described based on Figures 1 to 11, a lower drain member 15 is provided to which a siphon portion 17 of the same shape is applied, but the configuration of the siphon portion is not particularly limited.
Figure 18 shows a siphon section 62 in which an inlet section 60 that spreads upward in a funnel shape is provided on the upper inner side of the lower drain member 15, which has a vertical rib 48, and this inlet section 60 is suspended and supported above the upper flange section 31 by a plurality of support ribs 61.
Such a funnel-shaped inlet portion 60 has the same effect as the cover member 18 of the above-mentioned embodiment, that is, it makes it difficult for air to be sucked in and distributes stress to each vertical rib 19 (support rib 61).
FIG. 19 shows the configuration of a siphon portion 63 in which the vertical rib 48 provided in the siphon portion 62 shown in FIG. 18 is omitted.
The siphon section may adopt the configurations shown in Figures 18 and 19, and these configurations may be used to exert a siphon effect and add high drainage function to the rainwater drainage piping structure.

"Other embodiments"
For example, like the upper drain member 16 shown in FIGS. 20 and 21, the cover member 18 may be omitted.
In this case, a cylindrical or solid vertical rib connecting member 64 may be provided near the center of the upper drain member 16 (in the illustrated example, the vertical rib connecting member 64 is cylindrical). In addition, the vertical ribs 19 may be directly connected to each other (without the vertical rib connecting member 64) near the central axis of the upper drain member 16, for example, by integrating a part or the entire surface of a side surface of a vertical rib on the central axis side with a part or the entire surface of a side surface of another vertical rib on the central axis side. Furthermore, the upper ends of the vertical ribs 19 may be connected by an annular ring, for example, by integrating the upper end surfaces of the vertical ribs with the lower surface of an annular ring having an opening in the center.
This provides the same effect as the cover member 18 of the above embodiment, that is, the stress is dispersed among the vertical ribs 19.

Also, as shown in Figures 22 and 23, an expansion joint 70 having a rubber ring inside and a receiving port through which the spigot of an inserted pipe or joint can slide may be provided between the drainage member 8 and the elbow pipe 10 (Figure 22) or at the bottom of the elbow pipe 11 (Figure 23).
As a result, even if the drainage member 8 and the elbow pipes 10, 11 move relatively apart or close together as the corrugated roof 1 expands and contracts, the pipe and spigot at the lower part of the drainage member 8 inserted into the expansion joint 70, or the pipe and spigot at the lower part of the elbow pipe 11, slide within the receiving port of the expansion joint 70, thereby reducing the stress applied to the elbow pipes 10, 11 and the drainage member 8.

Fifth embodiment
FIG. 24 is an overall configuration diagram showing a rainwater drainage piping structure for an eaves gutter equipped with a drainage member according to the fifth embodiment of the present invention.
The piping structure of the fifth embodiment is an embodiment in which the structures of the lower drain member 15, the upper drain member 16, the first pipe 9, the elbow pipes 10 and 11, the call pipe YT, the down pipe 12, etc., which are previously described based on Figure 1, are applied to the rooftop drainage section of a building, condominium, etc.
The structure of the fifth embodiment is provided on the outside of a connection between a rooftop floor (a floor constituting the rooftop) 101 of a building 100 and a waist wall 102 erected at a corner portion of the rooftop floor 101. The waist wall 102 is a waist wall of the rooftop floor of the building 100.

A frame-shaped roof drain 105 is provided inside the joint between the roof floor 101 and the waist wall 102. A horizontal pipe 106 that penetrates horizontally through the waist wall 102 is connected to this roof drain 105. A joint body 103 is connected to the outer end side of the horizontal pipe 106. A downspout 12 is connected to the lower part of the joint body 103.
In the fifth embodiment, the rainwater drainage piping structure S100 is constituted by a roof drain 105, a horizontal pipe 106, a joint body 103, a downspout 12, a pipe body portion 122 described later, and a cover member 128.
The downspout 12 extends downward along the exterior wall 108 of the building. The downspout 12 is connected to a drainage facility such as a catch basin or other drain pipe (not shown) provided on the ground near the building 100.

The roof drain 105 has an L-shaped frame 112 consisting of a bottom plate 110 and a side plate 111. A tubular member 113 for connecting piping is integrated into the frame 112. A through hole 111a is formed on the bottom side of the side plate 111. The tubular member 113 extends outward from the side plate 111 so as to extend outward from this through hole 111a.
The bottom plate 110 is installed in a corner portion of the rooftop floor 101, and the side plate 111 is in close contact with the bottom portion of the waist wall 102. The roof drain 105 is installed in the corner portion of the rooftop floor 101. The tubular member 113 is inserted into a through hole 102a formed in the bottom portion of the waist wall 102.
An L-shaped frame-shaped strainer 117 having a plurality of water passage holes is detachably attached to the inside of the frame 112 by bolts 118 and nuts 119. The frame 112 and the strainer 117 form the roof drain 105.

The end of the waterproof sheet 115 on the roof floor 101 side is sandwiched and held down by the bottom plate 110 of the roof drain 105 and the bottom of the strainer 117. Similarly, the end of the waterproof sheet 116 on the waist wall 102 side may be sandwiched and held down by the side plate 111 and the upper part of the strainer 117.
The roof drain 105 used in this embodiment is just one example. The structure of the roof drain applied to the present invention may be any roof drain of a general structure, such as a general frame type or box type, as appropriate.

The horizontal pipe 106 is for drainage. The horizontal pipe 106 extends along a horizontal plane with an appropriate water gradient. A longitudinal portion of the horizontal pipe 106 is disposed within the through hole 102a of the waist wall 102. A first end of the horizontal pipe 106 is connected to the tubular member 113 of the roof drain 105. A second end of the horizontal pipe 106 opposite the first end protrudes outside the through hole 102a. The horizontal pipe 106 penetrates the waist wall 102. The horizontal pipe 106 is formed of polyvinyl chloride resin or the like.

The joint body 103 includes a pipe body 122, a horizontal pipe connection part 123, a vertical pipe connection part 124, and a drainage member (drain member) 8. The pipe body 122, the horizontal pipe connection part 123, and the vertical pipe connection part 124 constitute the joint body 103. The joint body 103 may be a piping box member.
The pipe main body 122 may be a so-called Tee pipe having a T-shape. The pipe main body 122 is configured by providing a connection part, which is an opening part that communicates with the inside of the straight pipe part, on the side of the straight pipe part having a circular tube shape. The pipe main body 122 is installed on the outside of the waist wall 102 so that the central axis of the straight pipe part is along the vertical direction. When installing the pipe main body 122, it is acceptable to install the central axis of the straight pipe part so that it is slightly inclined from the vertical direction.
A bottom plate 122a is formed on the inner bottom of the pipe main body 122, and a through hole 122b is formed in the center of this bottom plate 122a. A removable lid member 125 may be provided at the upper end opening of the pipe main body 122. The lid member 125 may be attached to the pipe main body 122 by a fitting method such as a screw or engagement. By providing the lid member 125, if foreign matter accumulates inside the pipe main body 122, the foreign matter can be removed as appropriate. By removing the lid member 125, the upper end opening of the pipe main body 122 can be used as a cleaning port.

The horizontal pipe connection portion 123 and the vertical pipe connection portion 124 are each cylindrical.
The horizontal pipe connecting portion 123 is formed coaxially with the connecting portion of the pipe main body portion 122. A second end of the horizontal pipe 106 is disposed within the horizontal pipe connecting portion 123.
The upright pipe connection part 124 is formed coaxially with the straight pipe part at a lower part of the straight pipe part of the pipe main body part 122. The inner diameter of the upright pipe connection part 124 is the same as the inner diameter of the straight pipe part.

The pipe body 122, horizontal pipe connection part 123, and vertical pipe connection part 124 that constitute the fitting body 103 are integrally formed by injection molding resins such as olefin resins such as PE (polyethylene), PP (polypropylene), or PB (polybutene), rigid polyvinyl chloride resin, ABS (acrylonitrile butadiene styrene copolymer resin), and AES (acrylonitrile ethylene styrene copolymer resin).

In this embodiment, the drainage channel R' is formed by the horizontal pipe 106 and the joint body 103. The lower drain member 15 and the upper drain member 16 used in the first embodiment are attached to the bottom plate 122a of the pipe body 122, which also serves as the bottom of the drainage channel R'.
As shown in Fig. 24, the lower drain member 15 is disposed below the bottom plate 122a, and the upper drain member 16 is disposed above the bottom plate 122a. Thereafter, the outer peripheral thread portion 35 of the upper drain member 16 is screwed into the inner peripheral thread portion 44 of the lower drain member 15, as in the first embodiment shown in Fig. 3, thereby integrating the drain members 15, 16.

The rainwater drainage piping structure shown in FIG. 24 can provide the same effects as those of the structure of the first embodiment.
For example, even if the joint body 103 moves slightly in the left-right direction in FIG. 24 due to thermal contraction or wind pressure during strong winds, the load acting on the joint between the elbow pipes 10, 11 can be reduced because the first pipe 9 is provided as a separate member from the lower drain member 15 and the downspout 12. By providing the first pipe 9 as a separate member, the number of places where stress is concentrated can be increased, thereby dispersing the stress. In addition, the deformation of the first pipe 9 itself also reduces the stress concentration. Therefore, the configuration provided with the first pipe 9 can reduce the load acting on the connection portion of the elbow pipes 10, 11, and has the effect of preventing cracks from occurring in the sockets 10B, 11B of the elbow pipes 10, 11.
Moreover, each of the structures shown in the second to fourth embodiments may be applied to the joint body 103 shown in FIG.

The vertical ribs provided on the drain member in the previous embodiment may be provided at other positions as shown in the following example.
FIG. 25 shows a fifth modified example of a drain member applicable to the drainage member of the present invention, and shows an upper drain member 126 that can be applied in place of the upper drain member 16 shown in FIG. 3 in the first embodiment.
The upper drain member 126 has an upper flange portion 31 equivalent to the upper flange portion 31 provided on the upper drain member 16 of the first embodiment, an inner cylinder portion 32, an inner cylinder reduced diameter portion 33, and an outer peripheral thread portion 35. The inner cylinder portion 32 is inserted into and integrated with the outer cylinder portion 42 of the lower drain member 15, as in the first embodiment.

Two vertical ribs 127 are integrated with the upper surface of the upper flange portion 31. When the inner tube portion 32 and the upper flange portion 31 are viewed in plan, these two vertical ribs 127 are formed so as to be located parallel to each other and spaced apart from each other across the center of the inner tube portion 32. The two vertical ribs 127 may be formed at positions deviated from the center of the inner tube portion 32.
When providing the upper drain member 126, it is also possible to provide the finned joint 70E shown in Figure 4 on the downspout 12 without providing a siphon section on the inside of the eaves gutter 7. The finned joint 70E is configured to induce the siphon effect, and the upper drain member 126 is configured to prevent foreign matter and the like from flowing in.

FIG. 26 shows a sixth modified example of a drain member applicable to the drainage member of the present invention, and shows an upper drain member 136 that can be applied in place of the upper drain member 16 shown in FIG. 3 in the first embodiment.
The upper drain member 136 has an upper flange portion 31 equivalent to the upper flange portion 31 provided on the upper drain member 16 of the first embodiment, an inner cylindrical portion 32, an inner cylindrical reduced diameter portion 33, and an outer peripheral threaded portion 35. The inner cylindrical portion 32 is inserted into and integrated with the outer cylindrical portion 42 of the lower drain member 15, as in the first embodiment.

A vertical rib construct 138 is integrated with the upper surface of the upper flange portion 31, and is formed by integrating four vertical ribs 137 in a crisscross pattern in a plan view. These four vertical ribs 137 are formed in positions surrounding the center of the inner cylinder portion 32 when the inner cylinder portion 32 and the upper flange portion 31 are viewed in a plan view. The four vertical ribs 137 may be formed in positions offset from the center of the inner cylinder portion 32.
When the upper drain member 136 is provided, it is also possible to provide a finned joint 70E shown in Fig. 4 on the downpipe 12 without providing a siphon section on the inside of the eaves gutter 7. The finned joint 70E is configured to induce the siphon phenomenon, and the upper drain member 136 is configured to prevent foreign matter and the like from flowing in.
As shown in Figures 25 and 26, the vertical ribs 127, 137 provided on the upper flange portion 31 can have various shapes, but it is also possible to adopt a shape as seen in plan view shown in Figure 27 as an example.

FIG. 27A shows a seventh modified example of a drain member that can be applied to the drainage member according to the present invention.
In this modified example, two curved plates 147, each of which is hyperbolic in plan view, are arranged on the upper flange portion 31 so as to form an X-shape in plan view, and so that the intersection point e of the two curved plates 147 is located at the center of the inner cylinder portion 32. The curved plates 147 are arranged in an X-shape in plan view to form a vertical rib 148. Each of the two curved plates 147 is integrated with the upper surface of the upper flange portion 31 and the upper surface of the inner cylinder reduced diameter portion 33 so as to stand upright from these.
The upper flange portion 31 having the vertical rib 148 having the configuration shown in FIG. 27(A) can be applied to any of the previous embodiments.

FIG. 27(B) shows an eighth modified example of the drain member which can be applied to the drainage member according to the present invention.
This modified example is an example in which two curved plates 149, which are curved in a hyperbolic shape in plan view, are arranged on the upper flange portion 31. The two curved plates 149 are arranged such that their widthwise center portions in plan view (the position where the curvature rate of the curved plates is maximum) f face the center of the inner cylinder portion 32, and the concave sides of the curved plates 149 face the radially outer side of the inner cylinder portion 32. The curved plates 149, 149 are formed at symmetrical positions sandwiching the center of the inner cylinder portion 32 in plan view, and are integrated with the upper surface of the upper flange portion 31 and the upper surface of the inner cylinder reduced diameter portion 33 so as to stand upright from these. In this example, a vertical rib 150 is formed from the two curved plates 149.
The upper flange portion 31 having the vertical rib 150 having the configuration shown in FIG. 27(B) can be applied to any of the previous embodiments.
As shown in Figures 27 (A) and (B) , the vertical ribs 148, 150 may be formed so as to pass through the center of the inner tube portion 32 when viewed in a plan view, or may be formed so as not to pass through it.

FIG. 27C shows a ninth modified example of the drain member which can be applied to the drainage member according to the present invention.
In this modified example, three flat plate-like vertical ribs 151 are integrally formed with the upper surface of the upper flange portion 31 and the upper surface of the inner cylinder reduced diameter portion 33 so as to stand on these surfaces.
When each vertical rib 151 is viewed in plan, its one side end 151a is disposed at a circumferential position of the upper flange portion 31. The one side end 151a of each vertical rib 151 is disposed at a position spaced at 120° intervals in the circumferential direction of the circle drawn by the upper flange portion 31 shown in FIG. 27(C). Each vertical rib 151 extends from the position where the one side end 151a is disposed toward the inside of the inner tube portion 32. The other end 151b of the vertical rib 151 is disposed at a position slightly shifted from the center of the inner tube portion 32. The positions where the three ends 151b of the three vertical ribs 151 are disposed are the apexes of an equilateral triangle drawn by a chain line in FIG. 27(C) with the center position O32 of the inner tube portion 32 as the center position. When viewed in plan as shown in FIG. 27(C), the vertical rib 151 may be provided at a position shifted from the radial position of the inner tube portion 32.
The upper flange portion 31 having the vertical rib 151 configured as shown in FIG. 27(C) can be applied to any of the previous embodiments.

FIG. 27(D) shows a tenth modified example of the drain member which can be applied to the drainage member according to the present invention.
In this modified example, four flat vertical ribs 152 are integrally formed with the upper surface of the upper flange portion 31 and the upper surface of the inner cylinder reduced diameter portion 33 so as to stand on these surfaces.
When each vertical rib 152 is viewed in plan, its one side end 152a is disposed at a circumferential position of the upper flange portion 31. The one side end 152a of each vertical rib 152 is disposed at a position spaced at 90° intervals in the circumferential direction of the circle drawn by the upper flange portion 31 shown in FIG. 27(D). Each vertical rib 152 extends from the position where the one side end 152a is disposed toward the inside of the inner tube portion 32. The other end 152b of the vertical rib 152 is disposed at a position slightly shifted from the center of the inner tube portion 32. The positions where the four ends 152b of the four vertical ribs 152 are disposed are the apexes of a square drawn by a chain line in FIG. 27(D) with the center position O32 of the inner tube portion 32 as the center position. When viewed in plan as shown in FIG. 27(D), the vertical ribs 152 may be provided at a position shifted from the radial position of the inner tube portion 32.
The upper flange portion 31 having the vertical rib 152 configured as shown in FIG. 27(D) can be applied to any of the previous embodiments.

FIG. 27(E) shows an eleventh modified example of a drain member that can be applied to the drainage member according to the present invention.
In this modified example, five flat vertical ribs 153 are provided upright on the upper surface of the upper flange portion 31 and the upper surface of the inner cylinder reduced diameter portion 33 and are integrated therewith.
When each vertical rib 153 is viewed in plan, its one side end 153a is disposed at a circumferential position of the upper flange portion 31. The one side end 153a of each vertical rib 153 is disposed at a position spaced at 72° intervals in the circumferential direction of the circle drawn by the upper flange portion 31 shown in FIG. 27(E). Each vertical rib 153 extends from the position where the one side end 153a is disposed toward the inside of the inner tube portion 32. The other end 153b of the vertical rib 153 is disposed at a position slightly shifted from the center of the inner tube portion 32. The positions where the five ends 153b of the five vertical ribs 153 are disposed are the vertices of a regular pentagon drawn by a chain line in FIG. 27(E) with the center position O32 of the inner tube portion 32 as the center position. When viewed in plan as shown in FIG. 27(E), the vertical rib 153 may be provided at a position shifted from the radial position of the inner tube portion 32.

The upper flange portion 31 having the vertical rib 153 configured as shown in FIG. 27(E) can be applied to any of the previous embodiments.
As described above, various shapes can be adopted for the vertical ribs.

R: drainage channel, 1: folded plate roof, 2: wall portion, 7: eaves gutter, 7A: bottom plate, 7B: side plate,
7H: through hole; 8: drain member; 9: first pipe; 9A, 9B: spigot portion;
10, 11... elbow pipe, 12... downpipe, 15... lower drain member, 16... upper drain member,
17: siphon portion, 18: lid member, 18A: outer periphery, 22: drop opening portion,
31: upper flange portion; 32: inner cylinder portion; 41: lower flange portion; 41H: receiving port;
42: outer cylinder portion; 42F: socket portion; 45: first tube; 45A: socket portion; 45B: spigot portion;
53: coupling pipe; 53A: socket portion (for outer tube portion);
53B: Socket portion (first pipe socket portion), 54: First pipe, 55: Extension tube portion,
70E... finned joint, 103... joint body, 122a... bottom plate, 122b... through hole,
105...roof drain, 106...horizontal pipe.

Claims (8)

A rainwater drainage piping structure including a drainage member into which rainwater is introduced, a call pipe connected to the drainage member, a downpipe connected to the call pipe, and a finned joint installed between the call pipe and the downpipe or installed in the downpipe,
The rainwater drainage piping structure, wherein the length of the call gutter is 1000 mm or less. The inner diameter of the pipe of the downpipe is larger than the inner diameter of the pipe of the downpipe.
The rainwater drainage piping structure according to claim 1. The call pipe is provided with a pair of upper and lower elbow pipes, and the finned joint is connected directly below the elbow pipe located below.
The rainwater drainage piping structure according to claim 1 or 2. The downspout connected below the finned joint has a length of 2000 mm or more.
The rainwater drainage piping structure according to claim 1 or 2. A first pipe is provided between the drainage member and the outlet gutter.
The rainwater drainage piping structure according to claim 1 or 2. A first pipe is provided between the drainage member and the outlet gutter.
The rainwater drainage piping structure according to claim 3. The drainage member has an extension tube portion at a lower portion thereof.
The rainwater drainage piping structure according to claim 1 or 2. The drainage member has an extension tube portion at a lower portion thereof.
The rainwater drainage piping structure according to claim 3.

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