Piping construction

Abstract

To provide piping structure that enhances effect of cut-off performance against water immersion from an outdoor side.SOLUTION: Piping structure comprises: a sheath pipe 21 that is embedded in a foundation and has both end parts opened to an outdoor-side surface of the foundation and an indoor surface-side of the foundation; a drainage pipe 26 that is disposed inside the sheath pipe 21 and has a socket part 28A at least on an outdoor-side; and a packing 50 that is installed between an outdoor-side opening part 21A of the sheath pipe 21 and an outdoor-side socket part 28A of the drainage pipe 26. The drainage pipe 26 has a protrusion 28a on an outer peripheral surface of the socket part 28A. The packing 50 has an outer surface-side protrusion 53 that protrudes from a packing outer peripheral surface 52a of the packing 50, and a recess part 56 that fits with the protrusion 28a on an inner peripheral surface. The outer surface-side projection 53 is closer to an opening part 21A than the recess part 56 and the protrusion 28a.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a piping structure. [Background technology]

[0002] A conventional foundation penetration pipe is described in Patent Document 1. The foundation penetration pipe includes a sheath pipe that is buried in the foundation and has both ends that open to the outdoor surface of the foundation and the outdoor surface of the foundation, a drain pipe that is placed inside the sheath pipe and has a socket at the outdoor end, and a packing that is provided between the sheath pipe and the socket. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6093808 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional foundation penetration piping has room for improvement in terms of improving the waterproofing effect against water intrusion from the outside.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a piping structure that enhances the waterproofing effect against water intrusion from the outdoors. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention has the following aspects. (1) A piping structure comprising: a sheath pipe buried in a foundation, both ends of which open to the outdoor surface of the foundation and the indoor surface of the foundation, respectively; a drain pipe arranged inside the sheath pipe and having a receiving portion at least on the outdoor side; and a gasket installed between the outdoor opening of the sheath pipe and the outdoor receiving portion of the drain pipe, wherein the drain pipe has a protrusion on the outer surface of the receiving portion, and the gasket has an outer protrusion protruding from the outer surface of the gasket and a recess on the inner surface that fits with the protrusion, and the outer protrusion is located on the opening side of the recess and the protrusion. (2) In the above (1), the packing may have an inner surface side protrusion, and the inner surface side protrusion may be located closer to the opening than the recess and the protrusion. (3) In (1) or (2) above, the outer surface side protrusion includes a first outer surface side protrusion and a second outer surface side protrusion adjacent to the first outer surface side protrusion 53A, and a first corner portion which is the corner between the first outer surface side protrusion and the outer peripheral surface of the packing, and a second corner portion which is the corner between the second outer surface side protrusion and the outer peripheral surface of the packing may be separated. [Effects of the Invention]

[0007] According to the present invention, a piping structure can be provided that enhances the waterproofing effect against water intrusion from the outdoors. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view schematically illustrating a piping structure according to an embodiment of the present invention, taken along the axial direction of a drainage pipe. [Figure 2] 1 is a cross-sectional view along the pipe axis direction of a drainage pipe, schematically showing a packing that constitutes a piping structure according to one embodiment of the present invention. FIG. [Figure 3] FIG. 3 is an enlarged cross-sectional view of a part of FIG. 2. [Figure 4] FIG. 2 is an enlarged view of a region α shown in FIG. [Figure 5] FIG. 10 is a partial cross-sectional view along the axial direction of a drain pipe, schematically illustrating a packing that constitutes a piping structure according to a modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Piping structure] A piping structure according to one embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a cross-sectional view taken along the axial direction of a drainage pipe, schematically showing a piping structure according to one embodiment of the present invention. Fig. 2 is a cross-sectional view taken along the axial direction of a drainage pipe, schematically showing a packing constituting a piping structure according to one embodiment of the present invention. Fig. 3 is a cross-sectional view showing an enlarged portion of Fig. 2. Fig. 4 is an enlarged view of region α shown in Fig. 1.

[0010] As shown in Fig. 1, a piping structure 20 of this embodiment is applied to a foundation 12 of a building 11 such as a house. The piping structure 20 connects a drainage fixture arranged inside the building 11 to a drainage basin arranged outside the building 11. The piping structure 20 discharges wastewater from the drainage fixture into the drainage basin. Examples of drainage fixtures include toilets, vanities, and bathrooms.

[0011] The foundation 12 has a pressure-resistant plate 13 provided on the ground G and a rising portion 14 standing upward from the outer edge of the pressure-resistant plate 13. In this example, the outer surface 13a of the pressure-resistant plate 13 and the outer surface 14a of the rising portion 14 are flush with each other. The lower part of the pressure-resistant plate 13 is buried in the ground G. The upper part of the rising part 14 is connected to a wall 15. For example, the pressure-resistant plate 13 and the rising part 14 are integrally formed from reinforced concrete or the like.

[0012] The piping structure 20 includes a sheath pipe (piping material) 21, a drain pipe (inner pipe material) 26, and a packing 50. Hereinafter, the pipe axis direction of the sheath pipe 21 will be simply referred to as the axial direction. The sheath pipe 21 is buried in the foundation 12. Both ends of the sheath pipe 21 open to the outdoor surface of the foundation 12 and the outdoor surface of the foundation 12, respectively. In the example shown in the figure, the sheath pipe 21 opens to the outer surface 13a and the top surface 13b of the pressure-resistant plate 13, respectively.

[0013] The sheath pipe 21 has a first straight pipe portion 22, a curved pipe portion (bent pipe portion) 23, and a second straight pipe portion 24. These straight pipe portions 22, 24 and the curved pipe portion 23 are integrally molded from a resin such as vinyl chloride. The curved pipe section 23 is formed by bending a pipe into a curved shape. The straight pipe sections 22 and 24 are formed into a tubular shape that extends straight. The first straight pipe section 22 is connected to a first end of the curved pipe section 23. The second straight pipe section 24 is connected to a second end of the curved pipe section 23.

[0014] The end of the first straight pipe section 22 that is not connected to the curved pipe section 23 opens to the outer surface 13a of the pressure-resistant plate 13. The end of the second straight pipe section 24 that is not connected to the curved pipe section 23 opens to the upper surface 13b of the pressure-resistant plate 13. It is preferable that anti-termite tape 41 be attached to the outer circumferential surface of sheath pipe 21. For example, anti-termite tape 41 is a thin, plate-shaped, non-vulcanizing adhesive plastic body made of butyl rubber. Anti-termite tape 41 is attached to the end of sheath pipe 21 that is closest to the interior of building 11.

[0015] The drain pipe 26 is disposed inside the sheath pipe 21. The drain pipe 26 includes a pipe body 27 and sockets 28 and 29.

[0016] The pipe body 27 is a flexible pipe having flexibility. The pipe body 27 is deformable in the radial direction of the pipe body 27. The pipe body 27 has both a predetermined bending performance (flexibility) and a predetermined strength performance. The pipe body 27 can be formed, for example, by a structure including a long cylindrical base portion and a plurality of rib portions formed on the outer peripheral surface of the base portion at intervals in the longitudinal direction of the base portion. In this case, it is preferable to form the base portion from a flexible material such as polyethylene resin.

[0017] The sockets 28, 29 are provided at both ends of the pipe body 27. In this embodiment, the sockets 28, 29 include a first socket 28 provided at the outdoor end of the pipe body 27 and a second socket 29 provided at the indoor end of the pipe body 27. The first socket 28 is disposed within the end 22a of the first straight pipe section 22. The second socket 29 is disposed within the end 24a of the second straight pipe section 24. In the illustrated example, a portion of the second socket 29 protrudes from the end 24a to the outside of the sheath pipe 21.

[0018] The first socket 28 and the second socket 29 are both receptacles. A first connecting pipe 31 is connected to the first socket 28. The first connecting pipe 31 is also connected to a catch basin. A second connecting pipe 32 is connected to the second socket 29. The second connecting pipe 32 is also connected to a drain fixture.

[0019] A protrusion 28a is provided on the outer peripheral surface of the first socket 28. The protrusion 28a abuts against a second base portion 52 (described later) of the packing 50 in the axial direction to restrict movement of the packing 50. The protrusion 28a is provided around the entire circumferential direction of the first socket 28. Only one protrusion 28a is provided in the axial direction. In other words, multiple protrusions 28a are not lined up in the axial direction. When the protrusion 28a is viewed in a cross section passing through the axis of the first socket 28, the protrusion 28a is formed in a rectangular shape. It is preferable that the protrusion 28a be provided on the outer surface of the receiving portion of the first socket 28 to restrict the position of the packing 50.

[0020] The protrusion 28a may extend continuously around the entire circumference in the circumferential direction, or may be arranged discontinuously around the entire circumference in the circumferential direction. There may be only one protrusion 28a in the circumferential direction, or multiple protrusions 28a may be arranged in the circumferential direction. The sockets 28, 29 are formed by, for example, injection molding a resin into a mold.

[0021] As shown in Figure 1, the packing 50 is provided between the outdoor opening 21A of the sheath pipe 21 and the outdoor receiving portion 28A of the first socket 28 that constitutes the drain pipe 26. The packing 50 prevents water from entering between the sheath pipe 21 and the first socket 28 and between the sheath pipe 21 and the drain pipe 26. The packing 50 may also function as an anti-termite packing. The packing 50 is formed, for example, from SBR (styrene butadiene rubber) or the like.

[0022] As shown in FIGS. 2 and 3, the packing 50 includes a first base portion 51, a second base portion 52, an outer surface side projection 53, an inner surface side projection 54, and a stopper 55. The first base portion 51 is fitted between the sheath tube 21 and the first socket 28. The first base portion 51 is cylindrical. The outer peripheral surface of the first base portion 51 contacts (closely contacts) the inner peripheral surface of the sheath tube 21. The inner peripheral surface of the first base portion 51 contacts (closely contacts) the outer peripheral surface of the first socket 28.

[0023] The second base 52 is a portion of the packing 50 that supports the outer projections 53 and the inner projections 54 (a portion that serves as the base for the outer projections 53 and the inner projections 54). The second base 52 is annular. The second base 52 protrudes axially from the first base 51. The second base 52 is located on the indoor side of the first base 51. The second base 52 is disposed between the inner circumferential surface of the sheath tube 21 and the outer circumferential surface of the first socket 28. In this embodiment, the inner circumferential surface 52b of the second base 52 is in contact (close contact) with the outer circumferential surface of the first socket 28. Furthermore, there are portions of the packing outer circumferential surface 52a of the second base 52 that are not in contact with the inner circumferential surface of the sheath tube 21, making it easier to insert the packing 50.

[0024] The outer surface projection 53 is annular. The outer surface projection 53 projects from the second base 52 toward the inner peripheral surface of the sheath tube 21. The outer surface projection 53 is a protrusion that projects radially outward from the packing outer peripheral surface 52a of the second base 52 (the surface facing the inner peripheral surface of the sheath tube 21). In this embodiment, a plurality (two) of the outer surface projections 53 are arranged at intervals in the axial direction of the first socket 28, but this is not limiting and at least one or more projections may be provided. It is preferable that the tip of each outer surface projection 53, which is the end on the outer side in the radial direction (toward the sheath tube 21), is in contact (close contact) with the inner circumferential surface of the sheath tube 21. Each outer surface projection 53 gradually becomes thinner from the inner side toward the outer side in the radial direction of the first socket 28.

[0025] The inner surface side protrusion 54 is annular. The inner surface side protrusion 54 protrudes from the second base 52 toward the outer peripheral surface of the first socket 28. The inner surface side protrusion 54 is a protrusion that protrudes radially inward from the inner peripheral surface 52b of the second base 52 (the inner surface facing the outer peripheral surface of the first socket 28). In the present embodiment, a plurality (two) of the inner surface side protrusions 54 are arranged at intervals in the axial direction of the first socket 28, but this is not limiting and at least one or more protrusions may be provided. It is preferable that the tip of each inner surface protrusion 54, which is the end on the radially inner side (first socket 28 side), is in contact (close contact) with the outer peripheral surface of first socket 28. Each inner surface protrusion 54 gradually becomes thinner from the radially inner side of first socket 28 to the radially outer side. Furthermore, if the watertightness of the inner surfaces of the first socket 28 and the packing 50 is ensured, for example, by making the inner diameter of the second base 52 gradually narrower, the inner surface protrusion 54 does not necessarily have to be provided.

[0026] 2 and 3, the outer projection 53 is closer to the drain pipe 26 in the axial direction than the inner projection 54. Specifically, the first outer projection 53A is closer to the indoor side than the inner projection 54A, and the second outer projection 53B is closer to the indoor side than the inner projection 54B. By providing the inner projections 54A and 54B, contact pressure is generated from the inner projections 54A and 54B to the first socket 28, so that the watertightness of the gasket 50 can be ensured more than when only the first outer projection 53A and the second outer projection 53B are provided. Furthermore, by providing the first outer projection 53A indoors relative to the inner projection 54A, a pressure caused by contact of the first outer projection 53A with the inner circumferential surface of the sheath tube 21 is applied to the inner projection 54A located outdoors, generating a frictional force between the first socket 28 and the inner projection 54A, thereby stabilizing the contact pressure from the inner projection 54A to the first socket 28 and the contact pressure from the first outer projection 53A to the sheath tube 21. Similarly, by providing the second outer projection 53B indoors relative to the inner projection 54B, a pressure caused by contact of the second outer projection 53B with the inner circumferential surface of the sheath tube 21 is applied to the inner projection 54B located outdoors, generating a frictional force between the first socket 28 and the inner projection 54B, thereby stabilizing the contact pressure from the inner projection 54B to the first socket 28 and the contact pressure from the second outer projection 53B to the sheath tube 21. Here, the packing 50 has an outer projection 53 protruding from the outer surface of the packing 50 and a recess 56 on the inner circumferential surface that fits with the projection 28a. The outer projection 53 is located closer to the opening 21A (in the direction of arrow β) than the recess 56 and the projection 28a. This prevents the rear side 50i of the packing 50 from touching the inner surface of the sheath pipe 21 and from being dragged by the inner surface of the sheath pipe 21, mainly during installation. Therefore, the packing 50 is prevented from deforming in a direction that would cause the projection 28a to move out of the recess 56 so that the diameter of the rear side 50i of the packing 50 would expand, and the rear side 50i of the packing 50 is less likely to curl up. This ensures that the packing 50 is properly positioned and its watertightness is ensured. This allows for a piping structure 20 with improved watertightness against water seepage from the outdoors. 3, the inner surface projection 54 is closer to the outdoor opening 21A of the sheath tube 21 (in the direction of the arrow β) than the recess 56 and the projection 28a. This allows the inner surface projection 54 to be positioned in a portion of the packing 50 that has a relatively high rigidity, in the axial direction, where the outer surface projection 53 is located. This improves the watertightness of the inner surface of the packing 50.

[0027] FIG. 4 is an enlarged view of region α shown in FIG. 1. As shown in FIG. 4, a protrusion 28a is provided on the outer peripheral surface of the outdoor-side receptacle 28A of the first socket 28. The packing 50 also has a recess 56 on the inner peripheral surface 52b of the second base 52 that fits with the protrusion 28a. The recess 56 is recessed from the inner peripheral surface 52b of the second base 52 toward the radially outward direction of the second base 52. The indoor-side inner wall surface and the outdoor-side inner wall surface of the recess 56 extend perpendicular to the axial direction of the packing 50. Because the protrusion 28a on the outer peripheral surface of the receptacle 28A fits into the recess 56 on the inner peripheral surface 52b of the second base 52, the position at which the packing 50 fits relative to the drain pipe 26 is clearly defined. Furthermore, because the protrusion 28a abuts against the second base 52 in the axial direction, movement of the packing 50 is restricted, preventing the packing 50 from shifting relative to the drain pipe 26. If the recess 56 is not provided, the packing 50 will be misaligned with respect to the drain pipe 26, and the water blocking effect of the packing 50 cannot be ensured. It is not necessary to provide a recess 56 on the inner surface 52b of the second base portion 52 of the packing 50. In this case, the protrusion 28a on the outer surface of the receiving portion 28A is positioned so as to abut against the indoor tip of the packing 50.

[0028] 4, the height h1 of protrusion 28a of socket 28A, measured from the outer surface of socket 28A, is greater than the depth h2 of recess 56. As a result, when protrusion 28a of socket 28A is fitted into recess 56, protrusion 28a is elastically deformed in the height direction, and the force of protrusion 28a attempting to restore its shape causes protrusion 28a to adhere tightly to the inner surface of recess 56. This makes it possible to stabilize the contact pressure from protrusion 28a to recess 56.

[0029] 4, the width w1 of protrusion 28a of receiving portion 28A in the axial direction of first socket 28 is smaller than the width w2 of first socket 28 in the pipe axial direction of recess 56. This allows protrusion 28a of receiving portion 28A to be easily fitted into recess 56.

[0030] Protrusion 28a of receiving portion 28A is provided continuously or discontinuously in the circumferential direction on the outer peripheral surface of receiving portion 28A, and there is only one protrusion when viewed in a cross section along the tube axis direction of first socket 28. If protrusion 28a is provided continuously in the circumferential direction on the outer peripheral surface of receiving portion 28A, the contact pressure from protrusion 28a to recess 56 can be stabilized when protrusion 28a is fitted into recess 56. Furthermore, if protrusion 28a is provided discontinuously in the circumferential direction on the outer peripheral surface of receiving portion 28A, protrusion 28a of receiving portion 28A can be easily fitted into recess 56. Furthermore, if there is only one protrusion 28a of receiving portion 28A when viewed in a cross section along the tube axis direction of first socket 28, protrusion 28a of receiving portion 28A can be easily fitted into recess 56.

[0031] The length of protrusion 28a of receiving portion 28A in the circumferential direction of first socket 28 is longer than the length in the axial direction of first socket 28. This makes it difficult for protrusion 28a to fall out of recess 56 when protrusion 28a is fitted into recess 56 along the axial direction of first socket 28, ensuring that packing 50 can stop water.

[0032] 2 and 3, the indoor-side tip 52A of the second base 52 of the packing 50 has a cross-sectional shape along the pipe axis direction of the first socket 28 that gradually widens from the indoor side toward the outdoor side. As a result, even if the drain pipe 26 is eccentric and comes into contact with the packing 50 when inserting the packing 50 into the drain pipe 26, frictional resistance is less likely to occur between the drain pipe 26 and the packing 50, and the packing 50 can be prevented from shifting position relative to the drain pipe 26.

[0033] As shown in Figures 2 and 3, the packing 50 has a plurality of outer projections 53 (two in Figures 2 and 3) along the pipe axis direction of the first socket 28, and an inner projection 54 located outside of the outer projection 53 that is located furthest outside of the plurality of outer projections 53. By having a plurality of outer projections 53, the contact area between the packing 50 and the inner surface of the sheath pipe 21 is increased, making the packing 50 less likely to fall off from the drain pipe 26 and ensuring the watertightness of the packing 50. In addition, by having the inner projection 54 located outside of the outer projection 53 that is furthest outside of the plurality of outer projections 53, the contact pressure from the outer projection 53 against the sheath pipe 21 is supplemented by the contact pressure from the inner projection 54 against the first socket 28, allowing the packing 50 to be more stably fixed to the drain pipe 26. Here, the outer projection 53 includes a first outer projection 53A and a second outer projection 53B adjacent to the first outer projection 53A. As shown in FIG. 3, a first corner 53Ae, which is the corner between the first outer projection 53A and the outer peripheral surface (outer surface) 52a of the packing 50 and is the end on the second outer projection 53B side, is separated from a second corner 53Be, which is the corner between the second outer projection 53B and the outer peripheral surface (outer surface) 52a of the packing 50 and is the end on the first outer projection 53A side. This ensures a deformation margin for the outer projection 53, making the packing 50 less likely to roll up. This ensures that the packing 50 can effectively seal off the water between the sheath pipe 21 and the drain pipe 26.

[0034] As shown in Figures 2 and 3, the packing 50 has a plurality of outer projections 53 (two in Figures 2 and 3) along the pipe axis direction of the first socket 28, and an inner projection 54A between two adjacent first and second outer projections 53A and 53B of the plurality of outer projections 53. The presence of the plurality of outer projections 53 increases the contact area between the packing 50 and the inner surface of the sheath pipe 21, making the packing 50 less likely to fall off the drain pipe 26 and ensuring the watertightness of the packing 50. Furthermore, the presence of the inner projection 54A between two adjacent first and second outer projections 53A and 53B of the plurality of outer projections 53 makes it possible to supplement the contact pressure from the outer projections 53 against the sheath pipe 21 with the contact pressure from the inner projection 54B against the first socket 28, thereby more stably fixing the packing 50 to the drain pipe 26.

[0035] When the packing 50 has a plurality of outer surface side projections 53 (two in FIGS. 2 and 3) along the pipe axis direction of the first socket 28, it is preferable that the height d2 from the packing outer peripheral surface (outer surface) 52a of the packing 50 to the tip of the outer surface side projection 53 is greater than the distance between two adjacent first outer surface side projections 53A and second outer surface side projections 53B. Note that the distance between two adjacent first outer surface side projections 53A and second outer surface side projections 53B refers to the distance d1 between the first outer surface side projections 53A and second outer surface side projections 53B on the packing outer peripheral surface 52a of the packing 50. By making the height d2 greater than the distance d1, when inserting the packing 50 into the drain pipe 26, the tip of the first outer surface side projection 53A comes into contact with the second outer surface side projection 53B, preventing the packing 50 from falling toward the packing outer peripheral surface 52a, and preventing a loss of pressing force from the first outer surface side projection 53A to the inner peripheral surface of the sheath pipe 21. Note that the height from the packing outer peripheral surface (outer surface) 52a of the packing 50 to the tip of the outer surface side projection 53 may be smaller than the distance between the two adjacent first outer surface side projections 53A and second outer surface side projections 53B, but if the distance between the two adjacent first outer surface side projections 53A and second outer surface side projections 53B is too short, the outer surface side projections 53 cannot be provided.

[0036] Furthermore, since the packing 50 has a stopper 55 at the outdoor end of the second base 52 that protrudes from the packing outer surface 52a of the second base 52 toward the outside in the radial direction of the second base 52, by inserting the packing 50 into the sheath pipe 21 until the stopper 55 contacts the outdoor end of the sheath pipe 21, it is possible to clearly determine the insertion position of the packing 50 relative to the drain pipe 26. It is also possible to prevent the packing 50 from shifting position relative to the drain pipe 26 due to water pressure.

[0037] According to the piping structure 20 of this embodiment, it comprises a sheath pipe 21, a drain pipe 26 arranged inside the sheath pipe 21, and a gasket 50 installed between the outdoor opening 21A of the sheath pipe 21 and the outdoor receiving portion of the drain pipe 26, and the gasket 50 has an outer surface protrusion 53 and an inner surface protrusion 54, the outer surface protrusion 53 is a protrusion that protrudes from the outer surface (outer surface) 52a of the gasket of the second base 52 of the gasket 50, and the inner surface protrusion 54 is a protrusion that protrudes from the inner surface (inner surface) 52b of the second base 52 of the gasket 50, and since the outer surface protrusion 53 is closer to the receiving portion 28A of the first socket 28 that constitutes the drain pipe 26 than the inner surface protrusion 54, the water-stopping effect against water seepage from the outdoor side can be enhanced. The piping structure 20 of this embodiment includes a sheath pipe 21 buried in a foundation, with both ends opening to the outdoor and indoor surfaces of the foundation, a drain pipe 26 disposed inside the sheath pipe 21 and having a receptacle 28A at least on the outdoor side, and a gasket 50 installed between the outdoor opening 21A of the sheath pipe 21 and the outdoor receptacle 28A of the drain pipe 26. The drain pipe 26 has a protrusion 28a on the outer surface of the receptacle 28A. The gasket 50 has an outer protrusion 53 protruding from the outer surface 52a of the gasket 50 and a recess 56 on the inner surface that fits with the protrusion 28a. The outer protrusion 53 is located closer to the opening 21A than the recess 56 and the protrusion 28a. This prevents the back side 50i of the gasket 50 from touching the inner surface of the sheath pipe 21, preventing it from being dragged by the inner surface of the sheath pipe 21, mainly during installation. Therefore, the packing 50 can be prevented from deforming in the direction in which the projection 28a comes out of the recess 56 so as to expand the diameter of the back side 50i of the packing 50, and the back side 50i of the packing 50 is less likely to be turned up. This makes it possible to reliably position the packing 50 and ensure the watertightness of the packing 50. As a result, it is possible to provide a piping structure 20 that has an improved watertightness effect against water seeping in from the outdoors.

[0038] <Other embodiments> It should be noted that the present invention is not limited to the above-described embodiment.

[0039] For example, a packing 100 according to a modified example as shown in Fig. 5 may be employed. In the packing 100 according to the modified example, the same components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof will be omitted, with only the differences being described.

[0040] FIG. 5 is a partial cross-sectional view taken along the pipe axis direction of the drain pipe 26, schematically showing a packing 100 constituting a piping structure 20 according to a modified example of the present invention. 5 differs from the packing 50 shown in FIGS. 2 and 3 in that the indoor-side inner wall surface of the recess 56 is perpendicular to the axial direction of the packing 100, and the outdoor-side inner wall surface of the recess 56 is shaped to become more distant from the indoor-side inner wall surface as it moves away from the axis of the packing 100. That is, the recess 56 of the packing 100 is narrowed on the inlet side. This makes it difficult for the protrusion 28a of the first socket 28 fitted into the recess 56 to come out. In the packing 100 according to this modification, the outer surface projection 53 is also located closer to the opening 21A than the recess 56 and the projection 28a. This makes it difficult for the inner side 50i of the packing 50 to be turned up. This ensures that the packing 50 is positioned properly and that the packing 50 can stop water.

[0041] Furthermore, in the above embodiment, the recess 56 is provided on the inner peripheral surface 52b of the second base 52, but it may be provided on the inner peripheral surface of the first base 51. In this case, the protrusion 28a on the outer peripheral surface of the first socket 28 is provided at or near the outdoor end of the first socket 28, and the protrusion 28a is provided at the same position as the end of the sheath tube 21 or the same position as the stopper 55 of the packing 50. Note that even in this case, only one protrusion 28a is provided when viewed in a cross section along the axial direction of the first socket 28.

[0042] The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0043] In addition, within the scope of the spirit of the present invention, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described modified examples may be combined as appropriate. [Explanation of symbols]

[0044] 20 Piping structure 21 Sheath 26 Drain pipe 28 1st Socket (Socket) 28a protrusion 28A socket part 50 packing 53 External protrusion 54 Inner surface protrusion 56 Recess

Claims

1. a sheath pipe that is buried in a foundation and has both ends that open to an outdoor surface of the foundation and an indoor surface of the foundation, respectively; A drain pipe disposed inside the sheath pipe and having a receiving portion at least on the outdoor side; A gasket is provided between the outdoor opening of the sheath pipe and the outdoor receiving port of the drain pipe, The drain pipe has a protrusion on the outer peripheral surface of the receiving portion, The packing has an outer surface side protrusion protruding from an outer peripheral surface of the packing, and a recess on an inner peripheral surface that fits with the protrusion, The outer surface side protrusion is located closer to the opening than the recess and the protrusion. Piping structure.

2. The packing has an inner surface side protrusion, The inner surface side protrusion is located closer to the opening than the recess and the protrusion. The piping structure according to claim 1 .

3. the outer surface side protrusions include a first outer surface side protrusion and a second outer surface side protrusion adjacent to the first outer surface side protrusion, A first corner, which is a corner between the first outer surface side projection and the outer peripheral surface of the packing, and a second corner, which is a corner between the second outer surface side projection and the outer peripheral surface of the packing, are spaced apart from each other. The piping structure according to claim 1 or 2.

Images