Drainage system

Abstract

To provide a drainage system that has excellent drainage properties even when the amount of water is relatively small.SOLUTION: A drainage system comprises: a horizontal pipe 200 connected to an inlet 100 provided on a rooftop R; a vertical pipe 400 provided downstream of the horizontal pipe 200; and a first joint 300 connecting the horizontal pipe 200 and the vertical pipe 400. The first joint 300 comprises: a main body 310; an upstream connection portion 321 which is formed upstream of the main body 310 and to which the horizontal pipe 200 is connected; and a downstream connection portion 322 which is formed downstream of the main body 310 and to which the vertical pipe 400 is connected. A cross-sectional area of the main body 310 is 1.0 to 4.0 times a cross-sectional area of the vertical pipe 400.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a drainage system. [Background technology]

[0002] In drainage systems used in buildings, a structure for generating a siphon effect inside the drainage pipes is sometimes adopted to increase the efficiency of drainage. Some buildings have flat roofs with no slope. In these cases, a piping structure is required to drain rainwater that accumulates on the roof. One possible piping structure is one that includes a horizontal pipe connected to a roof drain on the roof, a vertical pipe extending vertically along the building, and a piping manhole member that connects the horizontal pipe and the vertical pipe.

[0003] Patent document 1 discloses a piping structure in which the opening area of the horizontal pipe is 2.0 to 7.0 times the opening area of the vertical pipe as a drainage system that can increase the amount of wastewater treatment without compromising appearance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-152744 Summary of the Invention [Problem to be solved by the invention]

[0005] However, for example, on the rooftop of a small house, the total amount of rainwater that falls on the rooftop is smaller than on the rooftop of a large building because the rooftop area is smaller. If the piping structure described in Patent Document 1 were used on a house with such a small rooftop, it would be impossible to ensure a water volume sufficient to fill the horizontal pipe, which has a large opening area, and there was a risk that the siphon effect would not occur.

[0006] The present invention has been made in consideration of such problems, and has an object to provide a drainage system that has excellent drainage properties even when the amount of water is relatively small. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention proposes the following means. (1) A drainage system for draining water from the roof of a building, comprising: a horizontal pull pipe connected to an inlet located on the roof; a vertical pipe located downstream of the horizontal pull pipe; and a first joint connecting the horizontal pull pipe and the vertical pipe, wherein the first joint comprises a main body, an upstream connection formed upstream of the main body to which the horizontal pull pipe is connected, and a downstream connection formed downstream of the main body to which the vertical pipe is connected, and the cross-sectional area of the main body is 1.0 to 4.0 times the cross-sectional area of the vertical pipe. The drainage system of the present invention includes a horizontal pipe connected to an inlet, a standpipe located downstream of the horizontal pipe, and a first joint connecting the horizontal pipe and the standpipe. Water flowing from the horizontal pipe into the first joint changes its flow direction from horizontal to vertical. This change in water flow direction causes pressure loss due to geometric loss. This makes it difficult for air to enter the rainwater flowing into the first joint, inducing a siphon effect. Furthermore, if the cross-sectional area of the main body is greater than 1.0 times the cross-sectional area of the standpipe, pressure loss can be generated due to the difference between the cross-sectional areas of the first joint and the standpipe. Due to the pressure loss caused by the difference in the cross-sectional areas of the first joint and the standpipe, water accumulates upstream of the connection, i.e., inside the first joint. Furthermore, because the cross-sectional area of the main body is less than 2.0 times the cross-sectional area of the standpipe, the volume of the first joint can be reduced. This allows the area upstream of the connection to be easily filled with water, and when rainwater passes through the downstream connection, a large negative pressure is applied, allowing the rainwater to flow downstream in one go. Therefore, a drainage system with excellent drainage performance can be achieved even when the water volume is small. Furthermore, if the cross-sectional area of the main body is greater than 4.0 times the cross-sectional area of the standpipe, the projection dimension from the building wall may become too large, which may impair the design. If the cross-sectional area of the main body is 4.0 times or less the cross-sectional area of the standpipe, the appearance of the building will not be impaired, and a drainage system with excellent design can be achieved. (2) The downstream connection portion of the first joint may have a first reduced diameter portion that reduces in diameter toward the standpipe. With this configuration, pressure loss can be generated in the first reduced diameter section. Pressure loss in the first reduced diameter section causes water to accumulate upstream of the first reduced diameter section, i.e., inside the first joint. This allows the area upstream of the first reduced diameter section to easily fill with water, and the large negative pressure applied when rainwater passes through the first reduced diameter section allows the rainwater to flow downstream in one go. This results in a drainage system with excellent drainage performance even when the amount of water is small. (3) The cross-sectional area of the main body may be 1.0 times or more and less than 4.0 times the cross-sectional area of the horizontal drawing pipe. For example, if the cross-sectional area of the main body and the cross-sectional area of the horizontal pull-up pipe are equal, the flow rate can be maintained from the horizontal pull-up pipe to the first joint without causing pressure loss. Therefore, water can flow into the first joint while maintaining the flow rate, and the pressure loss allows water to accumulate inside the first joint. Furthermore, for example, if the cross-sectional area of the main body is larger than that of the horizontal pull-up pipe, the cross-sectional area of the horizontal pull-up pipe is small and its volume is relatively small, so even when the water volume is small, the water can easily be filled from the first joint to the inside of the horizontal pull-up pipe. Filling the water volume from the first joint to the inside of the horizontal pull-up pipe creates a large negative pressure as rainwater passes through the first reduced diameter section, allowing the rainwater to flow downstream in one go. This results in a drainage system with excellent drainage performance, even when the water volume is small. (4) The cross-sectional area of the horizontal pipe is 1.0 times or more and less than 4.0 times the cross-sectional area of the vertical pipe. For example, if the cross-sectional area of the horizontal lead pipe is the same as that of the standpipe, a horizontal lead pipe of conventional specifications can be used. Therefore, for example, the size of the penetration through which the horizontal lead pipe passes in a building can be the same as that of a conventional pipe, resulting in a drainage system with excellent cost and ease of construction. Furthermore, for example, if the cross-sectional area of the horizontal lead pipe is larger than that of the standpipe, the flow rate in the horizontal lead pipe can be made larger than that in the standpipe. Therefore, while maintaining the flow rate in the horizontal lead pipe, water can flow into the first fitting, and the pressure loss in the first reduced diameter section makes it easy to accumulate water inside the first fitting. By accumulating water inside the first fitting and applying a large negative pressure as the rainwater passes through the first reduced diameter section, the rainwater can be rapidly flushed downstream. Therefore, a drainage system with excellent drainage performance can be achieved even when the amount of water is small. (5) The length of the horizontal pipe is 600 mm or less. By limiting the length of the horizontal pull-out pipe, the volume of the horizontal pull-out pipe can be reduced, making it easier to fill the horizontal pull-out pipe with water, even when the amount of water is small. By filling the horizontal pull-out pipe with water, a large negative pressure is applied when passing through the first reduced diameter section, allowing more rainwater to flow downstream in one go. This results in a drainage system with excellent drainage performance even when the amount of water is small. (6) A second joint is arranged on the vertical pipe, and the second joint has a second reduced diameter portion, and the length from the lower end of the first reduced diameter portion of the first joint to the upper end of the second reduced diameter portion is greater than 1000 mm. With this configuration, a certain amount of water accumulates upstream of the second joint. Therefore, when rainwater passes through the contracted section of the second joint, a large negative pressure is applied, allowing the rainwater to flow downstream in one go, maintaining a high drainage volume. This results in a drainage system with excellent drainage performance even when the water volume is small. [Effects of the Invention]

[0008] The present invention can provide a drainage system that has excellent drainage properties even when the amount of water is relatively small. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a partial side view of the drainage system of the present invention. [Figure 2] FIG. 1 is a partial side view of a drainage system of the present invention using a drain at the inlet. [Figure 3] FIG. 2 is a perspective view of an inlet provided in the drainage system of the present invention. [Figure 4] FIG. 10 is a perspective view showing a modified example of an inlet provided in the drainage system of the present invention. [Figure 5] FIG. 10 is a perspective view showing a modified example of an inlet provided in the drainage system of the present invention. [Figure 6] FIG. 2 is a perspective view showing a first joint provided in the drainage system of the present invention. [Figure 7] FIG. 10 is a perspective view showing a drainage system in which a second joint is arranged in a part of the standpipe. DETAILED DESCRIPTION OF THE INVENTION

[0010] A drainage system 1 according to the present invention will be described below with reference to FIGS.

[0011] FIG. 1 shows a side view of a drainage system 1 of the present invention. As shown in Figure 1, the drainage system 1 is installed in a building 2 with a flat roof. A flat roof is a flat roof with a wall (parapet P) rising up around the perimeter of the roof. The drainage system 1 is installed outside the building 2.

[0012] The drainage system 1 moves rainwater that falls on the roof R of the building 2 to the vicinity of the ground and drains it, for example, into a sewer pipe. The number of drainage systems 1 installed in the building 2 may be one or two or more. If the building 2 is equipped with, for example, two drainage systems 1, the two drainage systems 1 may be arranged near opposite sides of the building 2.

[0013] 1, the drainage system 1 includes an inlet 100, a horizontal pipe 200, a first joint 300, and a vertical pipe 400. Specifically, the drainage system 1 includes the inlet 100 disposed on the rooftop R, the horizontal pipe 200 connected to the inlet 100, the vertical pipe 400 disposed downstream of the horizontal pipe 200, and a first joint 300 connecting the horizontal pipe 200 and the vertical pipe 400.

[0014] As shown in Fig. 1, the inlet 100 may have a strainer. As shown in Fig. 2, the strainer may be, for example, a drain. In the drainage system 1 shown in Fig. 1, the inlet 100 opens horizontally from the parapet P toward the rooftop R. In the drainage system 1 shown in Fig. 2, the inlet 100 opens upward from the slab of the rooftop R. In this drainage system, the inlet 100 and the horizontal pipe 200 are connected via a connecting pipe 401 (vertical pipe) and an elbow E.

[0015] 3, 4 and 5 show modified shapes of the inlet 100. These modified shapes are applicable to the drainage system 1 shown in FIG. 3, 4, and 5, the upper side in the vertical direction is the first side D1, and the lower side in the vertical direction is the second side D2.

[0016] As shown in FIG. 3 , the inlet 100A of the first embodiment has a lid portion 110. The lid portion 110 of the first embodiment has a semicircular shape whose diameter is the same as the outer diameter of the horizontal drawing tube 200 when viewed in the axial direction of the horizontal drawing tube 200, and covers the first side D1 (upper half) of the end of the horizontal drawing tube 200. Since the semicircular lid portion 110 covers the upper half (first side D1) of the end of the horizontal drawing tube 200, the vertical length B of the opening 140 of the inlet 100A of the first embodiment is half the vertical length A of the opening 140 of the inlet 100 (end of the horizontal drawing tube 200) without the lid portion 110. Note that the size and shape of the lid portion 110 are not limited to those described above. When viewed in the axial direction, the lid portion 110 only needs to cover at least a portion of the first side D1 of the inlet 100A, and may, for example, cover more than half of the inlet 100A. For example, the portion covered by the lid portion 110 may be less than half of the first side D1 of the inlet 100A. In this way, the inlet 100A of the first form has the cover 110, which allows the vertical length B of the opening 140 to be reduced. With this configuration, the vertical length B of the opening 140 of the inlet 100A can be made smaller than the water level on the rooftop R. This makes it possible to prevent air from entering through the inlet 100A, making it easier for the siphoning phenomenon to occur.

[0017] As shown in Fig. 4, the inlet 100B of the second embodiment has a gutter-shaped portion 120 in addition to a lid portion 110. As with the first embodiment, the lid portion 110 of the second embodiment has a semicircular shape whose diameter is the same as the outer diameter of the inlet 100B when viewed in the axial direction, and covers the first side D1 of the inlet 100B. In addition, the second side D2 of the inlet 100B is provided with a gutter-shaped portion 120 having a semicircular cross section. The gutter-shaped portion 120 functions as a receptacle into which rainwater that falls on the rooftop R flows. In this way, inlet 100B of the second form has cover 110, which reduces vertical length B of opening 140, and also has gutter-shaped portion 120 as a rainwater catchment tray. With this configuration, it is easy to ensure the water level at opening 140 by reducing vertical length B of opening 140 of inlet 100B and providing gutter-shaped portion 120. This makes it possible to prevent air from entering through inlet 100B, making it easier for the siphon effect to occur.

[0018] 5, the inlet 100C of the third embodiment has an extension 130. In the extension 130, a portion that contacts the end of the horizontal pull tube 200 is a base 131, and a portion on the opening 140 side is an expanded portion 132. In the extension 130, the vertical length C decreases from the base 131 to the expanded portion 132, and the horizontal length increases. This reduces the vertical length C of the opening 140, and makes it possible to make the opening area of the horizontal pull pipe 200 equivalent to the opening area of the inlet 100C having the extension 130. Because the opening area can be maintained, the vertical length C of the opening 140 of the inlet 100C can be made smaller than the water level on the rooftop R without reducing the amount of water that can flow in per unit time. This makes it possible to prevent air from entering through the inlet 100C while maintaining the amount of water that can flow in, making it easier to prevent the siphon effect from occurring.

[0019] 1, the horizontal pipe 200 is connected to the inlet 100 arranged on the rooftop R. The horizontal pipe 200 connected to the inlet 100 is arranged horizontally and is connected to a first joint 300 described below.

[0020] The material of the horizontal drawing pipe 200 is not particularly limited, and for example, a resin pipe or a metal pipe can be used. The inner diameter L1 of the horizontal drawing pipe 200 is not particularly limited, and may be, for example, 56 mm. The inner diameter L1 of the horizontal drawing pipe 200 is not limited to 56 mm, and may be 54 mm, 58 mm, or the like. In this embodiment, the cross-sectional area of the horizontal drawing pipe 200 is smaller than the cross-sectional area of the main body 310 of the first joint 300. The cross-sectional area of the horizontal drawing pipe 200 may be equal to the cross-sectional area of the main body 310 of the first joint 300. The cross-sectional area of the horizontal drawing pipe 200 is equal to the cross-sectional area of the standpipe 400. The cross-sectional area of the horizontal drawing pipe 200 may be larger than the cross-sectional area of the standpipe 400.

[0021] The horizontal length L4 of the horizontal lead pipe 200 is preferably 600 mm or less. If the horizontal length L4 of the horizontal lead pipe 200 is 600 mm or less, the amount of water required to fill the horizontal lead pipe 200 can be reduced. The horizontal length L4 of the horizontal lead pipe 200 is more preferably 300 mm or less, and even more preferably 200 mm or less. If the horizontal length L4 of the horizontal lead pipe 200 is 300 mm or less, the amount of water required to fill the horizontal lead pipe 200 can be reduced. For example, in the configuration shown in FIG. 1, the horizontal length L4 of the horizontal lead pipe 200 refers to the horizontal length from the end of the horizontal lead pipe 200 connected to the inlet 100 to the central axis of the standpipe 400. For example, in the configuration shown in FIG. 2, the horizontal length L4 of the horizontal lead pipe 200 refers to the horizontal length from the central axis of the connecting pipe 401 to the central axis of the standpipe 400. The horizontal drawing pipe 200 may have a water gradient from the upstream side to the downstream side. If the horizontal drawing pipe 200 has a water gradient from the upstream side to the downstream side, it is possible to prevent water from accumulating inside the horizontal drawing pipe 200.

[0022] 1, the first joint 300 has a main body 310, an upstream connection part 321, a downstream connection part 322, a cleaning port 340, and a lid 330. Note that the cleaning port 340 and the lid 330 do not necessarily have to be provided.

[0023] The material of the first joint 300 is not particularly limited, and for example, a resin pipe or a metal pipe can be used. The main body 310 is a cylindrical body extending in the vertical direction. The upstream connection portion 321 protrudes from the side surface of the main body 310. The cleaning port 340 is at the upper end of the main body 310. The lid 330 is detachably attached to the cleaning port 340. If the cleaning port 340 and the main body 310 are not present, the upper end of the main body 310 may be closed. The downstream connection portion 322 is provided at the lower end of the main body 310. In the illustrated example, the diameter of the downstream connection portion 322 decreases as it extends downward. The cross-sectional area of the main body 310 of the first fitting 300 is equal to or larger than the cross-sectional area of the standpipe 400. Specifically, the cross-sectional area of the main body 310 is 1.0 to 4.0 times the cross-sectional area of the standpipe 400. If the cross-sectional area of the main body 310 is larger than 1.0 times the cross-sectional area of the standpipe 400, pressure loss (pressure loss) occurs in the first reduced diameter section 322a when rainwater attempts to flow from the main body 310 into the standpipe 400. The pressure loss in the first reduced diameter section 322a temporarily blocks the inflow of water from the first fitting 300 to the standpipe 400, causing water to accumulate upstream of the first reduced diameter section 322a, i.e., inside the first fitting 300. This makes it easy to fill the area upstream of the first reduced diameter section 322a, including the horizontal pipe 200, with water. Air is less likely to enter the rainwater, and a large negative pressure is applied when the rainwater passes through the first reduced diameter section 322a, allowing rainwater that has filled the horizontal pipe 200, for example, to be quickly flushed downstream. Furthermore, if the cross-sectional area of the main body 310 is greater than 4.0 times the cross-sectional area of the standpipe 400, the volume of the main body 310 increases, which may make it difficult to fill the inside of the main body 310 with water. Furthermore, if the cross-sectional area of the main body 310 is greater than 4.0 times the cross-sectional area of the standpipe 400, the pressure loss that occurs at the first reduced diameter section 322a becomes too large, which is not preferable. To increase the head difference, the bottom surface of the upstream connecting portion 321 may be spaced a predetermined distance from the reduced diameter portion 322a. The predetermined distance is, for example, 10 mm or more, and more preferably 20 mm or more. Increasing the head difference increases the amount of water upstream of the full-flow point, making it easier for the siphon effect to continue. This further improves drainage performance.

[0024] In this embodiment, the cross-sectional area of the main body 310 of the first joint 300 is larger than the cross-sectional area of the lateral pulling pipe 200. Note that the cross-sectional area of the main body 310 of the first joint 300 may be equal to the cross-sectional area of the lateral pulling pipe 200. Specifically, the cross-sectional area of the main body 310 of the first joint 300 is preferably 1.0 times or more and less than 4.0 times the cross-sectional area of the lateral pulling pipe 200. The inner diameter L2 of the main body 310 of the first joint 300 is not particularly limited to a specific value, but may be, for example, 60 mm. The inner diameter L2 of the main body 310 of the first joint 300 is not limited to 60 mm, and may be 80 mm, 90 mm, 100 mm, or the like.

[0025] The lateral leading pipe 200 is connected to the upstream connecting portion 321 of the first joint 300. The inner diameter of the upstream connecting portion 321 of the first joint 300 is equal to the outer diameter of the lateral leading pipe 200. A standpipe 400 is connected to the downstream connecting portion 322 of the first joint 300. In this embodiment, the cross-sectional area of the main body 310 of the first joint 300 is larger than the cross-sectional area of the standpipe 400, which will be described later. Therefore, the downstream connecting portion 322 of the first joint 300 has a first reduced diameter portion 322a whose diameter decreases toward the standpipe 400. The cross-sectional area of the first reduced diameter portion 322a gradually decreases from the cross-sectional area of the main body 310 to the cross-sectional area of the standpipe 400 as it moves downstream. The cross-sectional shape of the standpipe 400 is not limited to a circular shape. For example, if the cross-sectional shape of the standpipe 400 is rectangular, the main body 310 and the reduced diameter portion 322 may also have rectangular cross sections, but since the horizontal pull pipe 200 and the through hole are circular, it is preferable that the upstream connecting portion 321 have a circular cross section.

[0026] Fig. 6(a) is a schematic diagram of a first joint 300. Figs. 6(b) to 6(e) show modified examples of the first joint 300. The first joint 300 may have a cleaning port 340 and a cover 330, which are not shown. If the first joint 300 has the cleaning port 340, it becomes easier to clean the inside of the piping.

[0027] Fig. 6(a) shows a first embodiment of a first joint 300. In the first joint 300, a first reduced diameter portion 322a is provided coaxially with the axis of the main body portion 310. The drainage system 1 shown in Figs. 1 and 2 uses the first joint 300. As shown in Fig. 6(b), the lower end of the main body 310 may be provided so as to cover part or all of the first vertical side D1 of the first reduced diameter portion 322a. As shown in Fig. 6(c), the upstream connecting portion 321 may have a curved shape in order to suppress the generation of turbulence. In the illustrated example, the upstream connecting portion 321 is curved downward as it approaches the main body 310.

[0028] 6(d) shows a second embodiment of the first joint 300. The first reduced diameter portion 322a of the first joint 300 is provided eccentrically in the horizontal direction toward the side where the upstream connection portion 321 is provided. If the first reduced diameter portion 322a is provided eccentrically in this manner, the standpipe 400 connected to the downstream connection portion 322 can be disposed close to the outer wall of the building 2. By disposing the standpipe 400 close to the outer wall of the building 2, it is possible to provide a drainage system 1 that is less susceptible to the effects of, for example, wind stress.

[0029] FIG. 6( e) shows a third embodiment of the first joint 300. The first joint 300 has a different starting point of the first reduced diameter section 322a on the side where the upstream connection section 321 is provided and the opposite side in the horizontal direction. Specifically, the first reduced diameter section 322a of the first joint 300 starts reducing at a position equal to or lower than the lower end 321b of the upstream connection section 321 on the side where the upstream connection section 321 is provided, while the opposite side starts reducing at a position higher than the lower end 321b of the upstream connection section 321. This allows the first reduced diameter section 322a to form a slope 322b that contacts the water flowing out of the horizontal supply pipe 200. The water flowing out of the horizontal supply pipe 200 hits the slope 322b formed by the first reduced diameter section 322a and is rectified. In this way, it is possible to prevent the water flow from coming into contact with the straight pipe portion 513 and generating turbulence.

[0030] It should be noted that the embodiments of the first joint 300 are not limited to those described above. The embodiments of the first joint 300 also include combinations of the above-described configurations.

[0031] 1, the standpipe 400 is connected to the downstream connecting portion 322 of the first joint 300. The standpipe 400 connected to the downstream connecting portion 322 of the first joint 300 is arranged along the vertical direction.

[0032] The material of the standpipe 400 is not particularly limited, and for example, a resin pipe or a metal pipe can be used. As described above, the cross-sectional area of the standpipe 400 is equal to or smaller than the cross-sectional area of the main body 310 of the first joint 300. The specific value of the inner diameter L3 of the standpipe 400 is not particularly limited, and may be, for example, 40 mm. The inner diameter L3 of the standpipe 400 is not limited to 40 mm, and may be 50 mm, 55 mm, 60 mm, or the like. In this embodiment, the cross-sectional area of the riser pipe 400 is equal to the cross-sectional area of the lateral drawing pipe 200. Note that the cross-sectional area of the riser pipe 400 may be smaller than the cross-sectional area of the lateral drawing pipe 200.

[0033] In this embodiment, a second joint 500 is disposed on the standpipe 400. The number of second joints 500 disposed on the standpipe 400 is not limited, and can be set appropriately depending on, for example, the length of the standpipe. FIG. 7 shows a schematic diagram of the drainage system 1 including a second joint 500 (finned joint). As shown in FIG. 7, the second joint 500 has a joint body 510 and a plurality of fins 520. The fitting body 510 is a cylindrical pipe having a central axis along the vertical direction, and has an inlet side joint portion 511 formed at the upper end, an outlet side joint portion 512 formed at the lower end, and a straight pipe portion 513 formed between them. The inlet-side joint 511 has a ring shape and is fixed by being coaxially fitted onto the lower end of the upstream standpipe 400. The inner peripheral surface of the inlet-side joint 511 is slightly larger than the outer diameter of the lower end of the upstream standpipe 400, and is watertightly connected to the lower end of the standpipe 400 via a sealing material (not shown). The outlet-side joint 512 also has a ring shape, and is fixed by being coaxially fitted onto the upper end of the downstream-side standpipe 400. The inner peripheral surface of the outlet-side joint 512 is slightly larger than the outer diameter of the upper end of the downstream-side standpipe 400, and is watertightly connected to the upper end of the downstream-side standpipe 400 via a sealing material (not shown). Note that although the case of external fitting has been exemplified in this embodiment, it is not limited to external fitting, and internal fitting may also be used. In the case of internal fitting, an external shape can be obtained in which the outer diameter at this connection position does not change in the pipe axial direction (there is no step), so that a drainage system 1 with excellent aesthetics can be obtained.

[0034] The straight pipe section 513 is a cylindrical pipe that is disposed between the inlet side joint 511 and the outlet side joint 512 and is coaxial with the inlet side joint 511 and the outlet side joint 512. The nominal diameters of the upstream standpipe 400, the second joint 500, and the downstream standpipe 400 may be the same. In this case, the external appearance when viewed from the outside is unified, resulting in a drainage system 1 that is aesthetically pleasing. The inner diameter dimension of the straight pipe portion 513 is also equal to the inner diameter L3 of the upstream standpipe 400 and the inner diameter L3 of the downstream standpipe 400. Therefore, the flow path extending vertically through the interiors of the upstream standpipe 400, the second joint 500, and the downstream standpipe 400 forms a cylindrical internal space having the same inner diameter at each position in the vertical direction, except for the portion where the fins 520 are arranged. In other words, the flow path from the upstream standpipe 400 via the second joint 500 to the downstream standpipe 400 is connected smoothly without any steps at both the connection point between the upstream standpipe 400 and the second joint 500 and the connection point between the second joint 500 and the upstream standpipe 400.

[0035] The fins 520 are a plurality of blades formed integrally with the inner wall surface of the straight pipe portion 513 of the second joint 500. In the case of this embodiment, four fins 520 are arranged at equal angular intervals (90° intervals) in the circumferential direction around the central axis of the straight pipe portion 513. The number of fins 520 is not limited to four, and may be two, three, five or more, or even ten or more. Each fin 520 has the same shape and dimensions, and is also positioned in the same position along the pipe axis direction. That is, as shown in FIG. 5, all fins 520 are isosceles triangular in longitudinal cross section or side view, and their bases are connected to the inner wall surface of straight pipe section 513 so as to be integral with the wall surface. Therefore, each fin 520 is formed to protrude from the inner wall surface toward the pipe axis (central axis). One of the equal sides of the isosceles triangle that forms these fins 520, i.e., a straight upper side 521, is located on the upstream side (vertically upper side) of the flow path, and the other straight lower side 522 is located on the downstream side (vertically lower side) of the flow path. The upper side 521 and the lower side 522 are connected at connection point 523. The shape of fin 520 is not limited to the isosceles triangle shown in FIG. 7, but may be, for example, a right-angled triangle or a trapezoid. Second joint 500 is not limited to a configuration having fins 520. For example, a ring-shaped protrusion that narrows the inner diameter of the joint, or the inner diameter of the joint itself may be reduced, may be used.

[0036] Each fin 520 is arranged so as to face another fin 520 at a circumferential position on the opposite side across the tube axis. In the present embodiment, as described above, the four fins 520 are arranged at equal angular intervals when viewed along the tube axis, so that two pairs of fins 520 are arranged facing each other across the tube axis. Each upper edge 521 of these fins 520 forms a thin, inclined surface that protrudes into the flow path. These inclined surfaces connect to the inner wall surface at the uppermost position of the upper edge 521, and the height that they protrude from the inner wall surface gradually increases from this uppermost position toward the downstream side, until they reach their highest point at connection point 523. The thin inclined surface formed by the upper edges 521 arranged in this manner faces rainwater flowing down from the upstream side, and as this rainwater hits the inclined surface, it creates flow path resistance.

[0037] Each lower edge 522 of each fin 520 also forms a thin inclined surface that protrudes into the flow path. These inclined surfaces connect to the inner wall surface at the lowest end position of the lower edge 522, and the height that protrudes from the inner wall surface gradually increases from this lowest end position toward the upstream side, until the height that protrudes from the inner wall surface is greatest at the connection point 523. In other words, the inclined surface formed on each upper edge 521 and the inclined surface formed on each lower edge 522 have the same shape and dimensions, but the inclination directions are opposite in the vertical direction, with the connection point 523 as the boundary.

[0038] In this way, the portion where fin 520 protrudes and the water passage area is smaller than inner wall portion 513a is defined as second reduced diameter portion 530.

[0039] The left side surface 524 and the right side surface 525 of each fin 520 are flat surfaces each having an isosceles triangle shape and are parallel to each other. Therefore, each fin 520 has a constant thickness from its upper end to its lower end. Because the left side surface 524 and the right side surface 525 extend into the flow path, viscous resistance is applied to the rainwater as it passes through each fin 520 by contacting the left side surface 524 and the right side surface 525. Therefore, the rainwater is subjected to both resistance due to contact with the inclined surface formed by the upper edge 521 and viscous resistance due to contact with the left side surface 524 and the right side surface 525.

[0040] As shown in FIG. 7, the second reduced diameter portion 530 is preferably disposed so that the length L4 between its upper end and the lower end of the first reduced diameter portion 322a is greater than 1000 mm.

[0041] The drainage system 1 of this embodiment moves rainwater to the vicinity of the ground, for example, as follows. Rainwater falling on the roof R of the building 2 is collected by the water gradient of the roof R and enters the inlet 100 through a strainer. The rainwater that enters the inlet 100 flows into the main body 310 of the first fitting 300 via the horizontal pipe 200 and the upstream connection portion 321. Here, the water flowing from the horizontal pipe 200 into the first fitting 300 changes its flow direction from horizontal to vertical. This change in the water flow direction causes pressure loss due to geometric loss. This makes it difficult for air to enter the rainwater flowing into the first fitting, potentially inducing a siphon effect. Next, the rainwater that flows into the main body 310 passes through the downstream connection portion 322 and attempts to flow into the standpipe 400. Here, the downstream connection portion 322 of the main body 310 has a first reduced diameter portion 322a that reduces in diameter toward the standpipe 400. Therefore, when rainwater attempts to flow from the main body 310 into the standpipe 400, a pressure loss occurs at the first reduced diameter section 322a. The pressure loss at the first reduced diameter section 322a temporarily blocks the flow of water from the first fitting 300 into the standpipe 400, causing water to accumulate upstream of the first reduced diameter section 322a, i.e., inside the first fitting 300. This makes it easy to fill the area upstream of the first reduced diameter section 322a, including the horizontal lead pipe 200, with water. Air is less likely to enter the rainwater, and a large negative pressure is applied as the rainwater passes through the first reduced diameter section 322a, allowing rainwater that has filled the horizontal lead pipe 200, for example, to flow downstream in one go. The rainwater that flows downstream in one go again experiences a pressure loss in the second reduced diameter section 530 of the second fitting 500. The pressure loss in the second reduced diameter section 530 of the second fitting 500 causes the rainwater, whose flow rate has been reduced, to temporarily accumulate upstream of the second reduced diameter section 530, making it difficult for air to enter the rainwater flowing into the second fitting 500, which can induce a siphon effect.

[0042] As described above, the drainage system 1 comprises a horizontal pull pipe 200 connected to an inlet 100 located on the rooftop R, a vertical pipe 400 located downstream of the horizontal pull pipe 200, and a first joint 300 connecting the horizontal pull pipe 200 and the vertical pipe 400, and the first joint 300 comprises a main body 310, an upstream connection portion 321 formed upstream of the main body 310 and to which the horizontal pull pipe 200 is connected, and a downstream connection portion 322 formed downstream of the main body 310 and to which the vertical pipe 400 is connected, and the cross-sectional area of the main body 310 is 1.0 to 4.0 times the cross-sectional area of the vertical pipe 400. The drainage system 1 includes a horizontal pipe 200 connected to the inlet 100, a standpipe 400 located downstream of the horizontal pipe 200, and a first joint 300 connecting the horizontal pipe 200 and the standpipe 400. Water flowing from the horizontal pipe 200 into the first joint 300 changes its flow direction from horizontal to vertical. This change in the direction of the water flow causes pressure loss due to shape loss. This makes it difficult for air to enter the rainwater flowing into the first joint, potentially inducing a siphon effect. Furthermore, if the cross-sectional area of the main body 310 is greater than 1.0 times the cross-sectional area of the standpipe 400, pressure loss can be generated due to the difference between the cross-sectional areas of the first joint 300 and the standpipe 400. Due to pressure loss caused by the difference in cross-sectional area between the first fitting 300 and the standpipe 400, water accumulates upstream of the connection, i.e., inside the first fitting 300. Furthermore, because the cross-sectional area of the main body 310 is 4.0 times or less that of the standpipe 400, the volume of the first fitting 300 can be reduced. This allows the area upstream of the connection to be easily filled with water, and the large negative pressure applied when rainwater passes through the downstream connection 322 allows the rainwater to flow downstream in one go. Therefore, the drainage system 1 has excellent drainage performance even when the water volume is small. Furthermore, if the cross-sectional area of the main body 310 is more than 4.0 times that of the standpipe 400, the projection dimension from the wall of the building 2 may become too large, which may impair the design. If the cross-sectional area of the main body 310 is 4.0 times or less that of the standpipe 400, the drainage system can be designed to have excellent design without impairing the appearance of the building.

[0043] Furthermore, the downstream connecting portion 322 of the first joint 300 may have a first reduced diameter portion 322 a that reduces in diameter toward the standpipe 400 . With this configuration, pressure loss can be generated in the first reduced diameter section 322a. The pressure loss in the first reduced diameter section 322a causes water to accumulate upstream of the first reduced diameter section 322a, i.e., inside the first fitting 300. This allows the upstream of the first reduced diameter section 322a to easily fill with water, and the large negative pressure applied when rainwater passes through the first reduced diameter section 322a allows the rainwater to flow downstream in one go. This allows the drainage system 1 to have excellent drainage performance even when the amount of water is small.

[0044] The cross-sectional area of the main body 310 may be 1.0 times or more and less than 4.0 times the cross-sectional area of the horizontal pulling tube 200 . For example, if the cross-sectional area of the main body 310 and the cross-sectional area of the horizontal lead pipe 200 are equal, water can flow into the first joint 300 while maintaining the flow rate from the horizontal lead pipe 200 to the first joint 300, and water can accumulate inside the first joint 300 due to pressure loss. Furthermore, for example, if the cross-sectional area of the main body 310 is larger than that of the horizontal lead pipe 200, the cross-sectional area of the horizontal lead pipe 200 is small and the volume of the horizontal lead pipe 200 is relatively small. Therefore, even when the amount of water is small, the area from the first joint 300 to the horizontal lead pipe 200 can be easily filled with water, even when the amount of water is small. Filling the area from the first joint 300 to the horizontal lead pipe 200 with water creates a large negative pressure as rainwater passes through the first reduced diameter section 322a, allowing the rainwater to flow downstream in one go. Therefore, the drainage system 1 has excellent drainage performance even when the amount of water is small.

[0045] The cross-sectional area of the horizontal drawing pipe 200 is 1.0 times or more and may be less than 4.0 times the cross-sectional area of the vertical pipe 400 . For example, if the cross-sectional area of the horizontal lead pipe 200 and the cross-sectional area of the standpipe 400 are the same, a horizontal lead pipe 200 conforming to a conventional standard can be used. Therefore, for example, the size of the penetration through which the horizontal lead pipe 200 passes in the building 2 can be the same as that of a conventional pipe, resulting in a drainage system 1 with excellent cost and ease of construction. Furthermore, for example, if the cross-sectional area of the horizontal lead pipe 200 is larger than that of the standpipe 400, the flow rate through the horizontal lead pipe 200 can be made larger than that through the standpipe 400. Therefore, while maintaining the flow rate through the horizontal lead pipe 200, water can flow into the first fitting 300. Due to the pressure loss at the first reduced diameter section 322a, water can easily accumulate inside the first fitting 300. Water can be accumulated inside the first fitting 300, and when rainwater passes through the first reduced diameter section 322a, a large negative pressure is applied, allowing the rainwater to flow downstream in one go. Therefore, the drainage system 1 has excellent drainage performance even when the amount of water is small.

[0046] The length of the horizontal pipe 200 may be 600 mm or less. By limiting the length of the horizontal supply pipe 200, the volume of the horizontal supply pipe 200 can be reduced, making it easier to fill the horizontal supply pipe 200 with water, even when the amount of water is small. By filling the horizontal supply pipe 200 with water, a large negative pressure is applied when the rainwater passes through the first reduced diameter section 322a, allowing more rainwater to flow downstream at once. Therefore, the drainage system 1 has excellent drainage performance even when the amount of water is small.

[0047] A second fitting 500 is arranged in the vertical pipe 400, and the second fitting 500 has a second reduced diameter portion 530, and the length from the lower end of the first reduced diameter portion 322a of the first fitting 300 to the upper end of the second reduced diameter portion 530 may be greater than 1000 mm. With this configuration, a certain amount of water accumulates upstream of the second joint 500. Therefore, when rainwater passes through the contracted section of the second joint 500, a large negative pressure is applied, allowing the rainwater to flow downstream in one go, maintaining a higher drainage volume. Therefore, the drainage system 1 has excellent drainage performance even when the amount of water is small. [Example]

[0048] A drainage system 1 having the position of the inlet 100, the cross-sectional area of the horizontal pipe 200, the cross-sectional area of the upright pipe 400, and the cross-sectional area of the first joint 300 shown in Table 1 was connected to a water tank, and a drainage experiment was conducted.

[0049] Example 1 In Example 1, the inlet 100 is connected to the bottom of the water tank. The cross-sectional areas of the horizontal pipe 200, the vertical pipe 400, and the first joint 300 are all the same. Connecting the inlet 100 to the bottom of the water tank refers to a state in which the bottom surface of the water tank and the inlet 100 are connected in a positional relationship similar to that of the top surface of the roof R and the inlet 100 shown in Figure 2.

[0050] Example 2 In Example 2, the inlet 100 is connected to the bottom of the water tank. The cross-sectional area of the horizontal pipe 200 and the cross-sectional area of the upright pipe 400 are the same, and the cross-sectional area of the main body 310 (mass) of the first joint 300 is 2.19 times the cross-sectional area of the upright pipe 400.

[0051] Example 3 In Example 3, the inlet 100 is connected to the side of the water tank. The cross-sectional area of the horizontal pull pipe 200 and the cross-sectional area of the standpipe 400 are the same, and the cross-sectional area of the main body 310 (mass) of the first joint 300 is 2.19 times the cross-sectional area of the standpipe 400. Connecting the inlet 100 to the side of the water tank refers to a state in which the side of the water tank and the inlet 100 are connected in a positional relationship similar to that of the parapet P of the rooftop R and the inlet 100 shown in Figure 1.

[0052] Example 4 In Example 4, the inlet 100 is connected to the bottom of the water tank. The cross-sectional area of the horizontal pipe 200 and the cross-sectional area of the upright pipe 400 are the same, and the cross-sectional area of the main body 310 (mass) of the first joint 300 is 3.65 times the cross-sectional area of the upright pipe 400.

[0053] (Comparative Example 1) In Comparative Example 1, the inlet 100 is connected to the bottom of the water tank. The cross-sectional area of the horizontal pipe 200 and the cross-sectional area of the standpipe 400 are the same, and the cross-sectional area of the main body 310 (mass) of the first joint 300 is 0.62 times the cross-sectional area of the standpipe 400.

[0054] (Comparative Example 2) In Comparative Example 2, the inlet 100 is connected to the bottom of the water tank. The cross-sectional area of the horizontal pipe 200 and the cross-sectional area of the upright pipe 400 are the same, and the cross-sectional area of the main body 310 (mass) of the first joint 300 is 5.47 times the cross-sectional area of the upright pipe 400.

[0055] In the drainage experiment, water was flowed into the tanks connected to each of the drainage systems 1 described above at flow rates of 77 L / min, 130 L / min, 160 L / min, 195 L / min, and 240 L / min, and the water level in the tanks was measured after the flow rate had stabilized. The results are shown in Table 1.

[0056] [Table 1]

[0057] As can be seen from the above results, in Examples 1 to 4, no matter what flow rate the water was let in, the water did not overflow from the water tank, and good results were obtained. In Comparative Example 1, where the cross-sectional area of the main body 310 of the first fitting 300 was 0.62 times that of the standpipe 400, and Comparative Example 2, where the cross-sectional area of the main body 310 of the first fitting 300 was 5.47 times that of the standpipe 400, water overflowed from the tank when water was flowing at a flow rate of 160 L / min or more, making measurement impossible. In Comparative Example 1, where the cross-sectional area of the main body 310 of the first fitting 300 was 0.62 times that of the standpipe 400, a full flow state could not be maintained when water flowed from the first fitting 300 to the standpipe 400. As a result, a siphon phenomenon occurred when water flowed from the first fitting 300 to the standpipe 400, and the drainage volume was lower than the flow rate. On the other hand, in comparison example 2, in which the cross-sectional area of the main body 310 of the first fitting 300 is 5.47 times the cross-sectional area of the standpipe 400, the pressure loss that occurs when water flows from the first fitting 300 to the standpipe 400 is too large, resulting in the discharged amount being lower than the flow rate when water is flowed at a flow rate of 160 L / min or more.

[0058] Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and configuration changes, combinations, deletions, etc. are also included within the scope that does not deviate from the gist of the present invention.

[0059] For example, the drainage system 1 does not have to have the second joint 500. [Explanation of symbols]

[0060] 1. Drainage system 100 Inlet 200 Horizontal draw pipe 300 First joint 310 Main body 321 Upstream Connection 322 Downstream Connection 322a 1st reduced diameter section 400 vertical pipe 500 Second joint 530 Second reduced diameter section R Rooftop 2. Building

Claims

1. A drainage system that drains water from the roof of a building, A horizontal pipe connected to the inlet located on the roof; a vertical pipe disposed downstream of the horizontal pipe; a first joint connecting the horizontal pipe and the vertical pipe; Equipped with The first joint is a main body; an upstream connection portion formed on the upstream side of the main body portion and to which the horizontal drawing pipe is connected; a downstream connection portion formed downstream of the main body portion and to which the upright pipe is connected; Equipped with The cross-sectional area of the main body is 1.0 to 4.0 times the cross-sectional area of the vertical pipe. Drainage system.

2. The downstream connection portion of the first joint has a first reduced diameter portion that reduces in diameter toward the standpipe. The drainage system of claim 1 .

3. The cross-sectional area of the main body is 1.0 times or more and less than 4.0 times the cross-sectional area of the horizontal pull tube. The drainage system of claim 2.

4. The cross-sectional area of the horizontal pipe is 1.0 times or more and less than 4.0 times the cross-sectional area of the vertical pipe. The drainage system of claim 2.

5. The length of the horizontal pipe is 600 mm or less. The drainage system of claim 2.

6. a second joint is disposed on the upright pipe; the second joint has a second reduced diameter portion, The length from the lower end of the first reduced diameter portion to the upper end of the second reduced diameter portion of the first joint is greater than 1000 mm. A drainage system according to any one of claims 2 to 5.

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