Diameter-expanding joints and drainage pipe structures

Abstract

In drainage pipe structures, the diameter is increased on the downstream side while minimizing the number of parts. [Solution] A diameter-expanding joint 25A used in a drain pipe structure 1A comprises a first connection port 26 connected to the upstream side of the drain pipe structure 1A, a second connection port 27 connected to the downstream side of the drain pipe structure 1A and having a larger diameter than the first connection port 26, and a curved pipe section 28 that connects the first connection port 26 and the second connection port 27 and expands in diameter from the first connection port 26 toward the second connection port 27.

Description

Technical Field

[0001] The present invention relates to a diameter-expanding joint and a drain pipe structure.

Background Art

[0002] Conventionally, a drain pipe structure described in Patent Document 1 below has been known. In this drain pipe structure, by providing an increaser in the vertical pipe, the downstream side of the drain pipe structure is expanded in diameter.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional drain pipe structure, there is room for improvement in reducing the number of parts.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to expand the diameter on the downstream side while suppressing the number of parts in a drain pipe structure.

Means for Solving the Problems

[0006] <1>A diameter-expanding joint according to an aspect of the present invention is a diameter-expanding joint used in a drain pipe structure, including a first connection port connected to the upstream side in the drain pipe structure, a second connection port connected to the downstream side in the drain pipe structure and having a larger diameter than the first connection port, and a curved pipe portion connecting the first connection port and the second connection port and expanding in diameter from the first connection port toward the second connection port.

[0007] The diameter-expanding joint is equipped with a first connection port, a second connection port, and a curved section. Therefore, by using this diameter-expanding joint as the joint to bend in the drain pipe structure, it is possible to expand the diameter of the downstream side of the drain pipe structure without having to use a separate joint solely for expanding the diameter of the piping, thus reducing the number of parts. Furthermore, by reducing the number of parts in this way, the amount of work required when connecting the parts can be reduced.

[0008] <2> the above <1> In the enlarged diameter joints related to this, a configuration made of polyolefin resin may be adopted. <3> the above <2> In the case of the enlarged diameter joint, a configuration that also functions as an electrofusion joint may be adopted.

[0009] When an expanding joint is made of polyolefin resin, it becomes necessary to connect this expanding joint to other components of the drainpipe structure by electrofusion rather than adhesive. Since electrofusion connection is time-consuming, the aforementioned effect of reducing labor costs by minimizing the number of parts is significantly beneficial. Furthermore, electrofusion connection requires electrofusion joints, which tends to increase the number of parts in the overall drainpipe structure. Therefore, the effect of minimizing the number of parts is also significantly beneficial. Moreover, if the expanding joint also functions as an electrofusion joint, this effect is even more pronounced.

[0010] <4> the above <1> from <3> In the diameter-enlarged joint relating to any one of the above, a configuration may be adopted in which a fire-resistant layer is laminated on the outer surface of the first connection port, the outer surface of the second connection port, and the outer surface of the curved pipe section.

[0011] A fire-resistant layer is laminated on the outer surface of the first connection port, the outer surface of the second connection port, and the outer surface of the curved pipe section. In drainage pipe structures that employ this type of diameter-expanding joint, components with a fire-resistant layer laminated on their outer surface are generally used. Connecting components with fire-resistant layers requires peeling off the fire-resistant layer at the connection point, which is time-consuming. Therefore, the aforementioned effect of reducing the number of components and thus reducing man-hours is particularly effective.

[0012] <5> the above <1> from <4> In the case of a diameter-enlarged joint relating to any one of the above, a configuration in which it is positioned downstream of the siphon generating member of the drain pipe structure may be adopted.

[0013] Downstream of the siphon generating component, the inside of the drainpipe structure becomes full of water, resulting in high water pressure. Therefore, for example, it becomes difficult for wastewater from other branch pipes to merge or for wastewater to be drained into the drainage pit. Therefore, the diameter-expanding joint is positioned downstream of the siphon generating member. This allows the water pressure to be reduced downstream of the diameter-expanding joint. As a result, for example, it becomes easier for wastewater to merge from other branch pipes or to drain into drainage pits.

[0014] <6> the above <1> from <5> In the diameter-enlarged joint relating to any one of the above, the second connection port may be configured to be connected to the upper end of the downpipe in the drainage pipe structure. <7> the above <1> from <5> In the diameter-enlarged joint relating to any one of the above, the first connection port may be configured to be connected to the lower end of the downpipe in the drainage pipe structure. <8> the above <1> from <7> In the case of an enlarged diameter joint relating to any one of the items, an elbow configuration may be adopted. <9> the above <1> from <7> In the expansion joint relating to any one of the items, a tee configuration may be adopted. <10> A drain pipe structure according to one aspect of the present invention is as described above. <1> from <9> It is equipped with an enlarged diameter joint according to any one of the items. [Effects of the Invention]

[0015] According to the present invention, in a drain pipe structure, the diameter on the downstream side can be increased while keeping the number of parts down. [Brief explanation of the drawing]

[0016] [Figure 1] This is a side view showing a drain pipe structure according to the first embodiment of the present invention. [Figure 2]It is a diagram for explaining the outline of the siphon drain member according to the first embodiment, and is a perspective view showing the state where the siphon drain member is attached to the eaves gutter. [Figure 3] It is a diagram for explaining the details of the siphon drain member according to the first embodiment, and is a perspective view including a cross section. [Figure 4] It is a diagram for explaining the outline of the siphon drain member according to the first embodiment, and is a side view seen from a direction orthogonal to the longitudinal direction of the eaves gutter. [Figure 5] It is an exploded side view for explaining the outline of the siphon drain member according to the first embodiment. [Figure 6] It is a longitudinal sectional view of the second elbow shown in FIG. 1. [Figure 7] It is a longitudinal sectional view of an enlarged-diameter cheese which is a first modification example of an enlarged-diameter joint that can be adopted instead of the second elbow shown in FIG. 1. [Figure 8] It is a side view of an enlarged-diameter elbow which is a second modification example of an enlarged-diameter joint that can be adopted instead of the second elbow shown in FIG. 1. [Figure 9] It is a side view of an enlarged-diameter elbow which is a third modification example of an enlarged-diameter joint that can be adopted instead of the second elbow shown in FIG. 1. [Figure 10] It is a side view of an enlarged-diameter elbow which is a fourth modification example of an enlarged-diameter joint that can be adopted instead of the second elbow shown in FIG. 1. [Figure 11] It is a longitudinal sectional view of an enlarged-diameter elbow which is a fifth modification example of an enlarged-diameter joint that can be adopted instead of the second elbow shown in FIG. 1. [Figure 12] It is a side view showing the drain pipe structure according to the second embodiment of the present invention. [Figure 13] It is a longitudinal sectional view of the third elbow shown in FIG. 12.

Embodiments for Carrying out the Invention

[0017] (First Embodiment) Hereinafter, referring to FIGS. 1 to 6, the first embodiment of the present invention will be described. In the embodiments and modifications described below, the numerical ranges indicating various sizes are merely illustrative examples of suitable numerical ranges, and the various sizes in the present invention are not limited to these illustrative numerical ranges.

[0018] As shown in Figure 1, the drainage pipe structure 1A drains rainwater into a rainwater catch basin 160. The drainage pipe structure 1A includes a gutter 10, a siphon drain member 100 (siphon generating member, drain) that penetrates the bottom plate 11 of the gutter 10, a first elbow 20 connected to the downstream side of the siphon drain member 100, a connecting pipe 24 connected to the downstream side of the first elbow 20, a second elbow 25 connected to the downstream side of the connecting pipe 24, a downpipe 30 connected to the downstream side of the second elbow 25, a third elbow 161 connected to the downstream side of the downpipe 30, and a horizontal pipe 162 connected to the downstream side of the third elbow 161. The downstream end of the horizontal pipe 162 is located inside the rainwater catch basin 160. In the illustrated example, the drainage pipe structure 1A is a rain gutter structure that drains rainwater from the gutter 10.

[0019] The gutter 10 is, for example, an extruded product made of synthetic resin such as rigid polyvinyl chloride resin, ABS, or AES. The material used to form the gutter 10 can be arbitrarily chosen and is not limited to synthetic resin; for example, it may be made of extruded metal.

[0020] When forming the gutter 10 from synthetic resin, the coefficient of linear expansion of the gutter 10 should be 2.0 × 10 to prevent thermal expansion and contraction. -5 It is preferable that the temperature is below / ℃. In order to reduce the coefficient of linear expansion, a low-stretch sheet such as a stretched PET resin sheet or an iron sheet can be inserted into the center of the thickness direction of the gutter 10, or low-stretch additives such as wollastonite or carbon fiber can be incorporated into the synthetic resin that makes up the gutter 10.

[0021] The bottom width of the gutter 10 may be between 100 mm and 200 mm. The height of the gutter 10 may be between 90 mm and 150 mm. The gutter 10 may be applied to a large-diameter downpipe capable of carrying rainwater at a flow rate of 4 liters / sec to 20 liters / sec, for example.

[0022] As shown in Figures 2 to 5, the siphon drain member 100 comprises a lower drain member 110, an upper drain member 120, and a siphon section 150. The lower drain member 110 includes, for example, a lower flange portion 111 positioned on the lower surface 11B of the gutter 10, an outer cylinder portion 112 formed below the lower flange portion 111 and extending downward, an outer cylinder reduced diameter portion 113 connecting the lower flange portion 111 and the outer cylinder portion 112, and an inner circumferential thread portion (not shown) formed on the inner circumferential surface of the outer cylinder portion 112.

[0023] The upper drain member 120 includes, for example, an upper flange portion 121 positioned on the upper surface 11A of the bottom plate 11 and having a drain opening portion 121H formed on its inner circumference, an inner cylinder portion 122 formed below the upper flange portion 121 and extending downward, an inner cylinder diameter reduction portion 123 connecting the upper flange portion 121 and the upper end of the inner cylinder portion 122 and decreasing in diameter as it extends downward, and an outer circumference threaded portion 125 formed on the outer circumference surface of the inner cylinder portion 122.

[0024] The lower drain member 110 and the upper drain member 120 are assembled to each other with the bottom plate 11 of the gutter 10 sandwiched between them, and the bottom plate 11 is sandwiched in the vertical direction. At this time, the inner circumferential threaded portion and the outer circumferential threaded portion 125 are screwed together.

[0025] The siphon section 150 is provided on the upper drain member 120. Rainwater from the eaves gutter 10 flows into the siphon section 150. The rainwater that flows into the siphon section 150 is drained downstream of the siphon generating member 100. The siphon section 150 drains the rainwater downstream without drawing in air, even when a large amount of rainwater flows in during heavy rain. As a result, downstream of the siphon generating member 100, for example, the inside of the downpipe 30 becomes full of water and a water seal is formed, causing the siphon phenomenon to occur. Such a siphon drain member 100 is suitably used in drainage pipe structures 1A installed in buildings of large facilities such as factories and shopping centers.

[0026] The siphon section 150 includes, for example, a lid member 151, a vertical rib 155 connecting the upper drain member 120 and the lid member 151, a gripping rib 156, and a guide 157. As shown in Figures 2 and 3, the lid member 151 is, for example, a circular disc-shaped member in plan view, positioned above the upper drain member 120. Furthermore, the lid member 151 is coaxial with the pipe axis of the upper drain member 120. The portion formed between the outer peripheral edge 151A of the lid member 151 and the outer peripheral edge 121C of the upper drain member 120 constitutes the inlet opening 100A through which rainwater W accumulated in the eaves gutter 10 flows into the outlet portion 121H.

[0027] The inlet opening 100A is located in a direction perpendicular to the horizontal plane and refers to the space between the outer edge 151A of the cover member 151 and the upper surface 11A of the gutter 10, or the space between the upper flange portion 121 of the upper drain member 120. For example, if the outer edge 151A of the lid member 151 is larger than the outer edge 121C of the upper flange portion 121, the inlet opening 100A will be the portion formed between the outer edge 151A of the lid member 151 and the upper surface 11A of the gutter 10. If the outer edge 151A of the lid member 151 is smaller than the outer edge 121C of the upper flange portion 121, the inlet opening 100A will be the portion formed between the outer edge 151A of the lid member 151 and the upper surface 121A of the upper flange portion 121.

[0028] The size, height, and shape of the lid member 151, described later, are adjusted so that the area of ​​the inlet opening 100A is larger than the opening area A1 of the drop-off section 121H described above. In this embodiment, the area of ​​the inlet opening 100A can be determined by multiplying the circumference of the circular lid member 151, i.e., the length of the outer edge 151A, by the height H of the lid member 151.

[0029] The lid member 151 is supported from below by a plurality of vertical ribs 155 and is supported by the upper drain member 120. Furthermore, as described above, the cover member 151 is positioned inside the gutter 10, spaced upward from the outlet portion 121H, and has an inlet opening 100A on the upper surface 11A of the gutter 10 below the cover member 151, allowing rainwater W to flow into the outlet portion 121H. Preferably, the cover member 151 is set at a height H of 10 to 60 mm upward from the upper surface 11A of the gutter 10.

[0030] Furthermore, while the size of the lid member 151 when viewed from above can be arbitrarily set, it is preferable that it be positioned to cover the opening of the drain portion 121H and that it be set to be larger than the opening area of ​​the drain portion 121H. It may also be set to be equal to or smaller than the opening area of ​​the drain portion 121H. Furthermore, for example, the lid member 151 may have a through hole formed in the vertical direction that penetrates from the top surface to the drop-off opening 121H.

[0031] Furthermore, it is more preferable that the height H of the cover member 151 is set 30 to 40 mm above the bottom surface 10a of the gutter 10, and that the diameter of the cover member 151 is set to 150 to 200% of the outer diameter R1 of the opening of the downspout 121H. If the diameter of the cover member 151 is less than 150% of the outer diameter R1 of the outlet portion 121H, the water level in the gutter 10 will be lower than the cover member 151, and there is a risk that the cover member 151 will not come into contact with the incoming water. Also, if the diameter of the cover member 151 exceeds 200%, the proportion of the water flow entering from the inlet opening 100A that collides with the cover member 151 will increase, and the water level in the gutter 10 may become too high above the cover member 151, potentially reducing the siphon performance.

[0032] Furthermore, for the siphon effect to occur, the water level in the gutter 10 must be higher than the inlet opening 100A, and the height H of the cover member 151 must be lower than the maximum water level in the gutter 10. For stable siphon effect generation, the height H of the cover member 151 is preferably 0.1 to 0.5 times the maximum water level in the gutter 10, and more preferably 0.2 to 0.45 times. The maximum water level inside the gutter 10 refers to the lowest height of the side plate 12 of the gutter 10 from the bottom plate 11.

[0033] Furthermore, the inner diameter (outer diameter of the opening) R1 of the inner circumferential hole 122H of the inner cylinder portion 122, which is suitable for providing the lid member 151 set in the above position, is preferably 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 outer diameter of the opening R1 of the outlet portion 121H to the lower limit of 50 mm or more, the large flow rate of wastewater generated in the siphon portion (siphon drain member 100) 50 can be drained smoothly. Furthermore, by limiting the upper limit to 170mm or less, the overall size is reduced, preventing the need for larger joints and support fixtures.

[0034] Furthermore, as shown in Figures 2 to 5, the lid member 151 is provided with gripping ribs 156 that protrude upward from the upper surface 151B and are spaced apart in the circumferential direction. By gripping these gripping ribs 156, the rotational operation when tightening the siphon drain member 100 can be easily performed.

[0035] Furthermore, the gripping rib 156 consists of a rib body 156A that extends in the circumferential direction and extensions 156B that protrude outward from both ends of the rib body 156A. Between adjacent gripping ribs 156, 156 in the circumferential direction, for example, when attaching the siphon drain member 100 to the first elbow 20, a rod-shaped member can be engaged and tightened by rotating the rod-shaped member. Furthermore, since gaps are formed between the gripping ribs 156, 156, fallen leaves and other debris inside the gutter 10 can pass through more easily, preventing them from getting tangled.

[0036] As shown in Figures 3 to 5, the guide guides 157 are provided radially from the drain axis O at the center of the lower surface 151C of the lid member 151 in a plan view, with multiple guide guides 157 having a curve that gradually extends downward toward the drain axis O (center of the lid). The guide guides 157 are for guiding rainwater W in the eaves gutter 10 from the inlet opening 100A to the outlet (opening of the outlet 121H). The guidance guide 157 may also be formed by a funnel-shaped or cylindrical wall portion with holes formed at its upper and lower ends.

[0037] As shown in Figure 3, the vertical ribs 155 connect the upper surface 121A of the upper drain member 120 to the outer periphery of the lower surface 151C of the cover member 151. That is, the cover member 151 is supported from below by multiple vertical ribs 155 and held at a position that secures a predetermined height H from the upper surface 11A of the gutter 10. These vertical ribs 155 are provided in the inlet opening 100A and are formed to intersect with respect to the radial direction in a plan view and are curved. In other words, the vertical ribs 155 have the function of straightening the flow of rainwater W that flows from the inlet opening 100A to the outlet 121H.

[0038] In the siphon section 150, the inner diameter of the inner circumferential hole 122H of the inner cylinder section 122 and the upper surface 123A (upper surface of the inner cylinder reduced diameter section 123) on the inner side to which the upper flange section 121 is connected have a bell mouth shape formed as a tapered or curved surface. When this upper surface (connecting section) 123A on the inner side is curved, the radius of curvature of the cross-section in the direction parallel to the drain axis O is preferably 5 mm to 20 mm.

[0039] The siphon drain member 100 described above is merely an example, and the siphon drain member 100 is not limited to the above configuration. The siphon drain member 100 can be appropriately modified to have other configurations that straighten the water flowing into the siphon drain member 100 and generate a siphon effect in the piping downstream of the siphon drain member 100. For example, the gripping rib 156 and the guide 157 may be omitted.

[0040] Furthermore, the material used to form the siphon drain member 100 can be arbitrarily selected. The siphon drain member 100 is, for example, an injection-molded product made from synthetic resins such as rigid polyvinyl chloride resin, polycarbonate, ABS, or AES. However, it is not limited to synthetic resins; it may also be formed by casting cast iron, stainless steel, or aluminum.

[0041] As shown in Figure 1, the first elbow (elbow member, joint member) 20 is a joint installed downstream of the siphon drain member (drain member) 100. The first elbow 20 is connected to the lower side of the siphon drain member 100. The first elbow 20 comprises a first socket (one end) 21, a second socket (the other end) 22, and a curved pipe section 23 that curves approximately 90° in a side view. The first socket 21 is connected to the lower drain member 110 of the siphon drain member 100. The second socket 22 is connected to the upstream end of the downpipe 24.

[0042] In order to allow rainwater W to flow smoothly without reducing the flow velocity of rainwater W flowing in from the first socket 21, it is preferable that the curved pipe section 23 is formed such that, when viewed in a cross-section including the pipe axis (along the pipe axis), the radius of curvature of the outer wall section (the side with less curvature) and the inner wall section is at least greater than 64 mm and less than 125 mm.

[0043] The connecting pipe 24 is a component that horizontally guides rainwater W flowing down from the first elbow 20, and horizontally directs rainwater W flowing down from the siphon drain component 100. It is a straight pipe that extends horizontally. The downstream side is connected to the upper end 30A of the downpipe 30 by the second elbow 25.

[0044] Furthermore, it is more preferable that the length of the connecting pipe 24 from its upstream end to its downstream end 24B (connecting pipe length) be 0.6m or more and 1.5m or less, and more preferable that it be 0.6m or more and 1.0m or less. By setting the length of the downpipe within the aforementioned range, rainwater W flowing down from the first elbow 20 can be smoothly drained when the pipe is full. The downstream end 24B of the downpipe 24 is connected to the first connection port 26 of the second elbow 25. The upper end 30A of the downpipe 30 is connected to the second connection port 27 of the second elbow 25.

[0045] The downpipe 30 is a component that allows rainwater W flowing down the second elbow 25 to flow vertically, and is a straight pipe that extends along the vertical direction. The downpipe 30 is a straight pipe that is installed vertically along the exterior wall of the building, and is a component that allows rainwater W flowing down from the second elbow 25 to flow downward.

[0046] The height from the upper end to the lower end of the downpipe 30 is, for example, 2.0 m or more, preferably 3.0 m or more, and more preferably 4.0 m or more. By keeping the length (height dimension) of the downpipe within the above range, the siphon effect in the downpipe 30 can be generated and maintained effectively. As the length of the downpipe increases, the amount of rainwater W flowing down to the lower end increases, and the rainwater W flows vigorously into the rainwater catch basin 160.

[0047] Rainwater flowing through the downpipe 30 is drained into the rainwater catch basin 160. The downpipe 30 and the rainwater catch basin 160 are connected via a third elbow 161 and a horizontal pipe 162. The lower end of the downpipe 30 is buried underground. The third elbow 161 is connected to the lower end of the downpipe 30. The first end of the horizontal pipe 162 is connected to the third elbow 161. The second end of the horizontal pipe 162 is located inside the rainwater catch basin 160. The third elbow 161 and the horizontal pipe 162 constitute a drainage pipe buried underground.

[0048] In the drainage pipe structure 1A assembled in this manner, rainwater that falls on the roof flows into the siphon drain member 100 provided in the gutter 10 through the inlet opening 100A, passes through the outlet section 121H, flows through the first elbow 20, the downpipe 24, and the second elbow 25, and flows down into the downpipe 30. Then, the rainwater W that flows from the downpipe 24 into the downpipe 30 is drained into the rainwater basin 160 through the third elbow 161 and the horizontal pipe 162, which are drainage pipes buried underground. At this time, the downstream side of the siphon drain member 100 is sealed with water when full, so the downpipe 30 is filled with water as it flows down, causing a siphon effect to occur in the outlet section 121H, the downpipe 24, and the downpipe 30, and the water is forcefully drained from the downpipe 30 to the drainage pipe side.

[0049] Furthermore, the components downstream of the siphon drain component 100 (first elbow 20, downpipe 24, second elbow 25, downpipe 30, third elbow 161, horizontal pipe 162) are formed from, for example, synthetic resin. Examples of synthetic resins include those that can bond each component to one another. Examples of synthetic resins include rigid polyvinyl chloride resin, polycarbonate, ABS, AES, etc.

[0050] In this embodiment, the drainpipe structure 1A is provided with a junction joint 31 (junction) in the downpipe 30. The junction joint 31 is located at an intermediate position in the height direction of the downpipe 30. The junction joint 31 is, for example, a tee. At the junction joint 31, rainwater flowing down the downpipe 30 is joined by rainwater from another downpipe 10A. In the illustrated example, the other downpipe 10A is not provided with a siphon drain member 100, but it may be provided.

[0051] In this embodiment, a second elbow 25A, as shown in Figure 6, is used as the second elbow 25. The second elbow 25A is an enlarged diameter joint (enlarged diameter elbow). The second elbow 25A includes a first connection port 26 connected to the upstream side of the drain pipe structure 1A, a second connection port 27 connected to the downstream side of the drain pipe structure 1A and having a larger diameter than the first connection port 26, and a curved pipe section 28 that connects the first connection port 26 and the second connection port 27 and expands in diameter from the first connection port 26 toward the second connection port 27. Both the first connection port 26 and the second connection port 27 are receiving ports. When the curved pipe section 28 is viewed in cross-section in a plane including the pipe axis of the curved pipe section 28, the curvature of the inner circumference portion of the curved pipe section 28 and the curvature of the outer circumference portion gradually change and become smaller. At this time, the radius of curvature of the inner circumference portion and the radius of curvature of the outer circumference portion of the curved pipe section 28 gradually increase. The second elbow, 25A, widens in diameter from upstream to downstream.

[0052] It is preferable that the nominal diameter of the second connection port 27 (large diameter socket, downstream socket) of the second elbow 25A is at least one size larger than the nominal diameter of the first connection port 26 (small diameter socket, upstream socket). For example, the nominal diameter of the first connection port 26 may be 75 (outer diameter 89 mm) or 100 (outer diameter 114 mm). The nominal diameter of the second connection port 27 may be 100 (outer diameter 114 mm) or 125 (outer diameter 140 mm). The second elbow 25A is positioned downstream of the siphon drain member 100. In the second elbow 25A, the first connection port 26 is connected to the downpipe 24, and the second connection port 27 is connected to the upper end of the downpipe 30.

[0053] As described above, according to the drain pipe structure 1A of this embodiment, the second elbow 25A is equipped with a first connection port 26, a second connection port 27, and a curved pipe section 28. Therefore, by adopting this second elbow 25A as the joint used in the curved section of the drain pipe structure 1A, it is possible to enlarge the downstream side of the drain pipe structure 1A without separately adopting a joint solely for the purpose of enlarging the diameter of the piping, that is, while keeping the number of parts down. Furthermore, by keeping the number of parts down in this way, the amount of work required when connecting the parts can be reduced.

[0054] Downstream of the siphon generating member 100, the inside of the drain pipe structure 1A becomes full of water, resulting in high water pressure. Therefore, for example, it becomes difficult for drainage from other rain gutters 10A to merge, or for the water to be drained into the rainwater catch basin 160. Therefore, the second elbow 25A is positioned downstream of the siphon generating member 100. This allows the water pressure to be reduced downstream of the second elbow 25A. As a result, for example, it becomes easier for drainage from other downpipes 10A to merge or to drain into the rainwater catch basin 160.

[0055] For example, in the drainage pipe structure 1A of this embodiment, if rainwater from another downspout 10A merges with the downspout 30 at an intermediate position, if the capacity of the downspout 30 is small, it is likely to become full, and there is a risk that the rainwater will not be able to merge at the merging joint 31. Therefore, as mentioned above, by adopting the second elbow 25A and increasing the capacity of the downspout 30 (by widening the diameter of the downspout 30), a margin is created in the allowable flow rate of the downspout 30, and the merging of rainwater is reliably achieved.

[0056] (Modification of the first embodiment) As a joint connecting the downpipe 24 and the downpipe 30 according to this embodiment, the following modified examples can be used.

[0057] (First variation) The joint connecting the downpipe 24 and the downpipe 30 is not limited to an elbow. For example, a tee 25B, as shown in Figure 7, may connect the downpipe 24 and the downpipe 30. The tee 25B has a first connection port 26, a second connection port 27, and a third connection port 29. The second connection port 27 and the third connection port 29 are connected through a straight pipe 29a. The curved pipe section 28 extends laterally from the straight pipe 29a. In the tee 25B, it is preferable to provide a cover (not shown) on the third connection port 29. The cover is detachable from the third connection port 29. The third connection port 29 functions as a cleanout. Alternatively, a downpipe for draining rainwater from a higher position may be connected without a cover.

[0058] (2nd variation to 4th variation) Various components constituting the drainpipe structure 1A may be formed from polyolefin resins. Examples of polyolefin resins include polyethylene (PE), polypropylene (PP), and polybutene (PB). Components formed from polyolefin resins are difficult to bond with adhesives. Therefore, so-called electrofusion is used to join the components. Such a drainpipe structure 1A formed from polyolefin resin is also suitably used, for example, in a configuration for draining rainwater from a roof drain (for example, a roof drain equipped with a siphon drain component 100) installed on the roof of a building or apartment complex. In this case, the second elbow 25 is suitably used, for example, at a position where the flow path is bent in the drainpipe structure. In this case, for example, drainage from an intermediate floor is drained from the horizontal pipe at the junction joint 31 in the downpipe 30 (vertical pipe).

[0059] Therefore, the second elbow 25C in the second modified example shown in Figure 8, and the second elbow 25D in the third modified example shown in Figure 9, both serve as electrofusion joints. These second elbows 25C and 25D are equipped with terminals 28a for electrofusion. The terminals 28a are used when voltage is applied. In the illustrated example, two terminals 28a are provided on the curved pipe section 28. However, two terminals 28a may be provided at each of the first connection port 26 and the second connection port 27. That is, the heating wire for electrofusion may be completed at each of the first connection port 26 and the second connection port 27. When the diameters of the first connection port 26 and the second connection port 27 are different, as in the second elbows 25C and 25D, the heating conditions (e.g., heating time and temperature) during electrofusion differ at the first connection port 26 and the second connection port 27, respectively. Therefore, it is preferable that the heating wire for electrofusion is completed at each of the first connection port 26 and the second connection port 27. In the second elbow 25C relating to the second modified example, the first connection port 26 and the second connection port 27 are receiving ports with a fixed inner diameter. On the other hand, in the second elbow 25D according to the third modified example, the first connection port 26 and the second connection port 27 are receiving ports with a variable inner diameter. In the second elbow 25D, the receiving ports of the first connection port 26 and the second connection port 27 are narrowed by tightening the bolts 26a and 27a provided in each connection port.

[0060] Note that, as shown in the fourth modified example in Figure 10, the second elbow 25E does not necessarily have to also function as an electrofusion joint. In this case, the first connection port 26 and the second connection port 27 become the sockets into which the electrofusion joint E is inserted. The electrofusion joint E connects the first connection port 26 to the downpipe 24. The electrofusion joint E also connects the second connection port 27 to the downpipe 30.

[0061] If the second elbow 25 is made of polyolefin resin, it will be necessary to connect this second elbow 25 to other components of the drain pipe structure 1A by electrofusion rather than adhesive. Since electrofusion connection is time-consuming, the aforementioned effect of reducing labor costs by minimizing the number of parts will be significantly effective. Furthermore, electrofusion connection requires electrofusion joints, which tends to increase the number of parts in the drain pipe structure 1A as a whole. Therefore, the effect of minimizing the number of parts will also be significantly effective. Moreover, if the second elbow 25 also serves as an electrofusion joint, as in the case of the second elbow 25C and 25D, this effect will be even more pronounced.

[0062] (Fifth variation) Various components constituting the drainpipe structure 1A may be covered with a fire-resistant layer. In this case, the second elbow 25F according to the fifth modified example shown in Figure 11 is also covered with a fire-resistant layer 40. The fire-resistant layer 40 is laminated on the outer surface of the first connection port 26, the outer surface of the second connection port 27, and the outer surface of the curved pipe section 28. A mortar layer is an example of the fire-resistant layer 40.

[0063] In this case, connecting parts equipped with the fire-resistant layer 40 requires peeling off the fire-resistant layer 40 at the connection point, which is time-consuming. Therefore, the aforementioned effect of reducing the number of parts to lower labor costs is particularly effective. Furthermore, this type of drainage pipe structure 1A, with its laminated fire-resistant layer, is also suitably used, similar to drainage pipe structures formed from polyolefin resins, for example, in configurations for draining rainwater from roof drains (for example, roof drains equipped with a siphon drain member 100) installed on the roofs of buildings and condominiums. In this case, the second elbow 25 is suitably used, for example, at a position where the flow path is bent in the drainage pipe structure. Also in this case, at the junction joint 31 in the downpipe 30 (vertical pipe), for example, drainage from an intermediate floor is discharged from the horizontal pipe.

[0064] (Second Embodiment) Next, a drain pipe structure 1B of the second embodiment of the present invention will be described with reference to Figures 12 and 13. In this second embodiment, the same reference numerals are used for parts that are the same as those in the first embodiment, and their descriptions are omitted. Only the differences will be described.

[0065] As shown in Figure 12, in the drain pipe structure 1B according to this embodiment, the second elbow 25 is a joint in which the first connection port 26 and the second connection port 27 have the same diameter. The downpipe 30 is not provided with a junction joint 31. In this embodiment, the third elbow 161 is the third elbow 161A as shown in Figure 13. The third elbow 161A is an enlarged diameter joint. Like the second elbow 25A in the first embodiment, the third elbow 161A is equipped with a first connection port 26, a second connection port 27, and a curved pipe section 28. The first connection port 26 is connected to the lower end of the downpipe 30. The second connection port 27 is connected to the first end of the horizontal pipe 162. In this case, the flow velocity inside the third elbow 161A is reduced. Therefore, splashing of water from the rainwater catch basin 160 can be prevented.

[0066] Here, as a modification of the third elbow 161A shown in the second embodiment, a configuration similar to the various modifications of the second elbow 25A shown in the first embodiment may be adopted. For example, the drain pipe structure 1B including the third elbow 161A may be made of a polyolefin resin and may be covered with a fire-resistant layer.

[0067] It should be noted that the technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention.

[0068] In drainage pipe structures 1A and 1B, both the second elbow 25A and the third elbow 161 may be expansion joints. The applications of the drainage pipe structure are not limited to draining rainwater from gutters. For example, it can also be used to drain rainwater from roof drains (for example, roof drains equipped with a siphon drain component 100) installed on the roofs of buildings and condominiums. In this case, the positions where expansion joints (elbows and tees) are installed can be set as appropriate.

[0069] Furthermore, without departing from the spirit of the present invention, the components in the above embodiments may be replaced with well-known components as appropriate, and the above-described modifications may be combined as appropriate. [Explanation of symbols]

[0070] 1A, 1B drain pipe structure 25A, 25C, 25D, 25E, 25F, 161A Elbow (Expanding Joint) 25B Tee (Expanding Joint) 26. First connection port 27 Second connection port 28 Bent pipe section 30 Downpipe 40 Fireproof layer 100 Siphon drain component (siphon generating component)

Claims

1. A diameter-enhancing joint used in drainage pipe structures, A first connection port connected to the upstream side of the drain pipe structure, A second connection port, which is larger in diameter than the first connection port, is connected to the downstream side of the drainage pipe structure. A diameter-expanding joint comprising a curved pipe section that connects the first connection port and the second connection port, and whose diameter expands as it moves from the first connection port toward the second connection port.

2. The diameter-expanding joint according to claim 1, which is formed of a polyolefin resin.

3. The diameter-enlarged joint according to claim 2, which also functions as an electrofusion joint.

4. The diameter-enlarging joint according to any one of claims 1 to 3, wherein a fire-resistant layer is laminated on the outer surface of the first connection port, the outer surface of the second connection port, and the outer surface of the curved pipe portion.

5. The diameter-enhancing joint according to any one of claims 1 to 4, which is positioned downstream of the siphon generating member of the drain pipe structure.

6. The diameter-enhancing joint according to any one of claims 1 to 5, wherein the second connection port is connected to the upper end of the downpipe in the drainage pipe structure.

7. The diameter-enhancing joint according to any one of claims 1 to 5, wherein the first connection port is connected to the lower end of a downpipe in the drainage pipe structure.

8. An elbow, an enlarged diameter joint according to any one of claims 1 to 7.

9. A cheese-type expanding joint according to any one of claims 1 to 7.

10. A drain pipe structure comprising an expanding joint according to any one of claims 1 to 9.

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