JP7751024B2 - Bush and coupling construction - Google Patents

Description

The present invention relates to a bushing and a joint structure.

Fittings such as those described in Patent Document 1 below have been known for some time.

Japanese Patent Application Laid-Open No. 2001-208257

However, it is desirable for this type of joint to have a simpler structure and be easier to manufacture.

The present invention was made in consideration of the above-mentioned circumstances, and aims to simplify the structure and facilitate manufacturing.

In order to solve the above problems, the present invention proposes the following means.
The bushing of the present invention comprises a main tube, a partition wall disposed within the main tube and dividing the interior of the main tube into a first space and a second space in a cross section intersecting the central axis of the main tube, a closing portion that closes the first space, and a protruding portion that protrudes from the partition wall into the second space.

The bushing is disposed, for example, between a first pipe and a second pipe having different diameters, and connects the first pipe and the second pipe after adjusting the difference in diameter between the first pipe and the second pipe (note that the first pipe and the second pipe here include joints). For example, the first pipe and the second pipe can be connected by inserting the main pipe into the first pipe and then inserting a second pipe having a smaller diameter than the first pipe into the second space.
In this bushing, the protruding portion protrudes from the partition wall into the second space, so that a part of the outer circumferential surface of the second pipe inserted into the second space abuts against the protruding portion, thereby holding the second pipe in the second space.
The protruding portion protrudes into the second space. Therefore, by increasing or decreasing the protruding dimension of the protruding portion into the second space, the cross-sectional area (inner diameter) of the second space can be increased or decreased while fixing the position and shape of the partition wall. Therefore, it is possible to form a second space that can accommodate second pipes of various sizes while ensuring design freedom regarding the position and shape of the partition wall.
However, when manufacturing a bushing using a mold, for example, the shape of the first and second spaces (the shape of the partition walls) may restrict the direction in which the mold can be removed from the first and second spaces. Due to this restriction, the position of the closure portion in the central axis direction may be limited depending on the position and shape of the partition walls. In some cases, it may be necessary to form the closure portion as a separate member from the main pipe and attach the closure portion to the main pipe later.
However, this bushing allows for greater design freedom in the partition wall. Therefore, while the closure and the main pipe are integrally molded, the axial position of the closure is less likely to be restricted, increasing the degree of freedom in the axial position of the closure. As a result, for example, the closure can be positioned at the end of the main pipe in the axial direction. This, for example, simplifies manufacturing and prevents fluid from flowing into the first space.

The blocking portion may be provided at the end of the main tube in the central axis direction.

The closure is located at the end of the main tube in the central axis direction. This prevents fluid from flowing into the first space from the side where the closure is located.

The protruding portion may have multiple protrusions.

The overhanging portion has a plurality of protrusions. Therefore, the overhanging portion can be formed by increasing the thickness of the partition wall at the portion where the overhanging portion is provided only in the portion corresponding to the protrusions. Therefore, the thickened portion of the partition wall can be limited to a narrow range.
When a bushing is injection molded using a resin or rubber material, sink marks in the material tend to occur in thicker portions, leading to poor quality. However, by providing a protruding portion (projection) in a portion of the wall while maintaining the thickness of the partition wall, it is possible to prevent sink marks and other issues from occurring during molding. This makes it possible to simplify the manufacture of the bushing.

The protruding portion may be provided only on a portion of the partition wall along the central axis of the main tube.

The protruding portion is provided only on a portion of the main tube in the central axial direction. Therefore, when inserting the end of the second tube into the second space, excessive frictional resistance between the second tube and the protruding portion can be prevented. This makes it easy to insert the second tube into the second space.

The joint structure of the present invention comprises a joint assembly having multiple pipe connection sections to which the ends of pipes are connected, and a bushing such as that described above provided at the pipe connection sections.

The bushing is disposed between the pipe connection part of the manifold and the pipe body, which have different diameters, and connects them after adjusting the difference in diameter between them. For example, the pipe connection part of the manifold can be connected to the pipe body by inserting the main pipe into the pipe connection part of the manifold and connecting the pipe body, which has a smaller diameter than the pipe connection part, to the second space.
In this bushing, the protruding portion protrudes from the partition wall into the second space, so that a part of the outer surface of the pipe inserted into the second space abuts against the protruding portion, thereby holding the pipe in the second space.
The protruding portion protrudes into the second space. Therefore, by increasing or decreasing the protruding dimension of the protruding portion into the second space, the cross-sectional area (inner diameter) of the second space can be increased or decreased while fixing the position and shape of the partition wall. Therefore, it is possible to form a second space that can accommodate pipes of various sizes while ensuring design freedom regarding the position and shape of the partition wall.
However, when manufacturing a bushing using a mold, for example, the shape of the first and second spaces (the shape of the partition walls) may restrict the direction in which the mold can be removed from the first and second spaces. Due to this restriction, the position of the closure portion in the central axis direction may be limited depending on the position and shape of the partition walls. In some cases, it may be necessary to form the closure portion as a separate member from the main pipe and attach the closure portion to the main pipe later.
However, this bushing allows for greater design freedom for the partition wall. Therefore, while the closure and the main pipe are integrally molded, the axial position of the closure is less restricted, increasing the degree of freedom in the axial position of the closure. As a result, for example, the closure can be positioned at the end of the main pipe in the axial direction. This simplifies manufacturing and prevents fluid from flowing into the first space.

This invention simplifies the structure and simplifies manufacturing.

1 is a vertical cross-sectional view showing a joint structure according to an embodiment of the present invention. FIG. 2 is a development view showing the component configuration of the joint structure shown in FIG. 1 . FIG. 2 is a vertical cross-sectional view of a bush used in the joint structure shown in FIG. 1 . FIG. 4 is a front view of the bushing shown in FIG. 3 . 2 is a perspective view of a bush and a second ring of the joint structure shown in FIG. 1, as viewed from below. FIG. FIG. 10 is a vertical cross-sectional view of a bushing according to a first modified example of the present embodiment. FIG. 10 is a vertical cross-sectional view of a bushing according to a second modified example of the present embodiment. FIG. 10 is a front view of a bushing according to a second modified example of the embodiment. FIG. 10 is a front view of a bush according to a third modified example of the embodiment. FIG. 10 is a vertical cross-sectional view of a bushing according to a fourth modified example of the present embodiment. FIG. 10 is a vertical cross-sectional view of a bushing according to a fifth modified example of the present embodiment. FIG. 13 is a front view of a bushing according to a sixth modified example of the embodiment. FIG. 13 is a vertical cross-sectional view of the bushing shown in FIG. 12. FIG. 13 is a vertical cross-sectional view of a bushing according to a seventh modified example of the present embodiment.

Hereinafter, a joint (joint structure) 1 according to one embodiment of the present invention will be described with reference to the drawings. The joint 1 is used, for example, for building drainage, and is disposed in a slab penetration hole formed in a floor slab.
As shown in FIGS. 1 and 2 , the joint portion 1 according to this embodiment includes a multi-joint 10 .

The manifold 10 comprises an upper connecting pipe 11, a lower connecting pipe 12, and an intermediate pipe 15 that connects the upper connecting pipe 11 and the lower connecting pipe 12. The upper connecting pipe 11 has a vertical pipe connecting portion 13 that can be connected to the first vertical pipe P1, and a horizontal pipe connecting portion 14 that protrudes from the side of the vertical pipe connecting portion 13 and can be connected to the horizontal pipe P3.

The vertical pipe connection portion 13 is tubular. The first vertical pipe P1 is connected to the first end (upper end) of the vertical pipe connection portion 13, and the lower connecting pipe 12 is connected to the second end (lower end) via an intermediate pipe 15. In the illustrated example, a retaining plate 13a protrudes from the inner surface of the vertical pipe connection portion 13 at a position that avoids the horizontal pipe connection portion 14, but the retaining plate 13a may be omitted. In the following description, the upper connecting pipe 11 side of the vertical pipe connection portion 13 along the central axis O of the vertical pipe connection portion 13 is referred to as the upper side, and the lower connecting pipe 12 side is referred to as the lower side.

The horizontal pipe connection portions 14 protrude from the outer peripheral surface of the vertical pipe connection portion 13. In the illustrated example, three horizontal pipe connection portions 14 are arranged at intervals around the central axis O. Two of the three horizontal pipe connection portions 14 are arranged separately, with the central axis O sandwiched between them. The remaining horizontal pipe connection portions 14 extend in directions that form 90° angles around the central axis O relative to the two horizontal pipe connection portions 14 when viewed from above. Note that the number and extension direction of the horizontal pipe connection portions 14 are not limited to this embodiment and can be changed as desired.

The upper connecting pipe 11 is obtained by injecting and filling a polyvinyl chloride resin composition containing, for example, 100 parts by weight of polyvinyl chloride resin and 0.1 to 1.0 parts by weight of non-expandable graphite into the cavity.

The intermediate pipe 15 is connected to the lower end of the upper connecting pipe 11. In the illustrated example, the upper end of the intermediate pipe 15 is fitted into the lower end of the vertical pipe connecting part 13. The intermediate pipe 15 preferably satisfies the performance requirements set forth in JIS K6741.
The intermediate tube 15 contains a resin composition containing a polyvinyl chloride resin and thermally expandable graphite, and is manufactured by, for example, extrusion molding the resin composition.

The intermediate tube 15 may have a single-layer structure in which the entire intermediate tube 15 is made of a resin composition, or may have a multi-layer structure made of multiple layers. In the case of a multi-layer structure, any one of the layers may be formed from a resin composition.
For example, when the intermediate pipe 15 has a three-layer structure consisting of a surface layer, a middle layer, and an inner layer, the intermediate pipe 15 may have a configuration in which the middle layer is formed from a resin composition.

Furthermore, for example, if the intermediate pipe 15 has a three-layer structure, the surface layer, intermediate layer, and inner layer may contain a heat-absorbing agent. The intermediate layer may contain thermally expandable graphite and therefore be black in color. In this case, it is preferable that the surface layer and inner layer contain a colorant other than black so that they can be distinguished from the intermediate layer. Note that if the intermediate pipe does not contain thermally expandable graphite, a sheet-like fire-resistant material containing thermally expandable graphite may be wrapped around the outer surface of the intermediate pipe 15 or the outer surface of the sound-proofing material covering the intermediate pipe 15, as described below, and the fire-resistant material may be embedded in the slab penetration portion.

The lower connecting pipe 12 is tubular, with a diameter that is smaller at the bottom than at the top. The lower connecting pipe 12 comprises a connecting pipe section 16 that connects to the intermediate pipe 15, an inclined pipe section 17 that extends downward from the connecting pipe section 16 and gradually reduces in diameter as it extends downward, and a lower pipe section 18 that is provided at the lower end of the inclined pipe section 17 and to which the second vertical pipe P2 is connected. The intermediate pipe 15 is fitted into the connecting pipe section 16. The second vertical pipe P2 is fitted into the lower pipe section 18. The connecting pipe section 16, inclined pipe section 17, and lower pipe section 18 are integrally formed, for example, by injection molding of a synthetic resin material.

The upper connecting pipe 11 and the lower connecting pipe 12 may be made transparent, allowing the connection state of the upper connecting pipe 11 and the lower connecting pipe 12 to be visually confirmed. The upper connecting pipe 11 and the lower connecting pipe 12 may also be compounded with a flame retardant such as non-thermally expandable graphite or magnesium hydroxide.

A first bushing 21, a first packing 22, and a first ring 23 are provided at the upper end of the upper connecting pipe 11 (the upper end of the vertical pipe connecting portion 13).
The first bushing 21 includes a fitting portion 21a, a support portion 21c, and a swirl vane 21b. The fitting portion 21a is formed in a tubular shape that fits into the vertical pipe connection portion 13. The support portion 21c extends downward from the fitting portion 21a. The swirl vane 21b is provided at the lower end of the support portion 21c. The swirl vane 21b extends around the central axis O.

The first packing 22 is fitted into the first bushing 21. The upper end of the first packing 22 is provided with a lip portion 22a that fits tightly against the outer peripheral surface of the first vertical pipe P1. The lower end of the first packing 22 is formed with an upward-facing step 22b. The end of the first vertical pipe P1 abuts against this step 22b.

The first ring 23 is fitted from the outside onto the upper end of the first bushing 21. A flange portion 23a is provided on the upper end of the first ring 23. The flange portion 23a prevents the first packing 22 from coming off the first bushing 21.
The first bushing 21 , the first packing 22 and the first ring 23 can be pre-assembled and integrated before being attached (bonded) to the upper connecting pipe 11 .

The first packing 22 and a second packing 32 (described later) are made of a rubber material that is generally used in drainage facilities, such as ethylene-propylene-diene rubber (EPDM).
The first bushing 21, the first ring 23, and the second bushing 31 and the second ring 33 described below are each obtained by injection molding a polyvinyl chloride resin composition containing 0.1 to 1.0 parts by weight of non-expandable graphite per 100 parts by weight of polyvinyl chloride resin. The first bushing 21 and the second bushing 31 may be made transparent.

A second bushing 31 , a second packing 32 , and a second ring 33 are provided at the tip of the horizontal pipe connection portion 14 .
The second bushing 31 is fitted into the horizontal pipe connecting portion 14 and is bonded to the horizontal pipe connecting portion 14. The tip of the second bushing 31 protrudes from the horizontal pipe connecting portion 14.

The second packing 32 is fitted into the second bushing 31 and is in close contact with the outer peripheral surface of the horizontal pipe P3. The second ring 33 is fitted onto the tip of the second bushing 31 from the outside. The second ring 33 has a flange portion 33a. The flange portion 33a prevents the second packing 32 from coming off the second bushing 31.

At least one horizontal pipe connection portion (pipe connection portion) 14</b>A among the plurality of horizontal pipe connection portions 14 uses a bush 50 as the second bush 31 as shown below.
As shown in FIGS. 3 and 4 , the bushing 50 includes a main pipe 51 , a partition wall 52 , a closing portion 53 , and a protruding portion 55 .

The main body tube 51 has a circular tubular shape. The first end 51a of the main body tube 51 is fitted into the horizontal pipe connection portion 14A. The second end 51b of the main body tube 51 protrudes to the outside from the horizontal pipe connection portion 14A. Hereinafter, the side of the first end 51a along the central axis C1 of the main body tube 51 will be referred to as the first side D1, and the side of the second end 51b will be referred to as the second side D2.

The partition wall 52 is provided inside the main body pipe 51. The partition wall 52 divides the inside of the main body pipe 51 into a first space S1 and a second space S2 in a cross section intersecting with the central axis C1.
4, the partition wall 52 is formed in an arc shape with a center of curvature at the central axis C2 in a front view seen from the direction of the central axis C1. The central axis C2 is parallel to the central axis C1 and offset from the central axis C1. The radius of curvature r2 of the partition wall 52 with the central axis C2 as the center of curvature is smaller than the radius of curvature r1 of the main pipe 51 with the central axis C1 as the center of curvature.

3, the partition wall 52 extends continuously along the central axis C1. The partition wall 52 has a constant thickness T in a direction intersecting the central axis C2 over a predetermined length from the first end 51a to the second end 51b of the main tube 51.
Hereinafter, a portion of the surface of the partition wall 52 that faces the direction in which the partition wall 52 curves and protrudes will be referred to as a first surface 52f of the partition wall 52. A portion of the surface of the partition wall 52 that is located on the opposite side of the first surface 52f across the partition wall 52 will be referred to as a second surface 52g. The first surface 52f forms a first space S1, and the second surface 52g forms a second space S2.

4, the first space S1 is formed between a first surface 52f of the partition wall 52 and an inner circumferential surface 51f of the main tube 51 facing the first surface 52f. The first space S1 has a crescent shape in a cross section intersecting with the central axis C1.
The second space S2 is formed between a second surface 52g of the partition wall 52 and an inner circumferential surface 51g of the main tube 51 facing the second surface 52g. The second space S2 has a substantially circular cross section perpendicular to the central axis C1. The central axis C2 is the central axis of the second space S2.

As shown in FIG. 1, a horizontal pipe P31 is inserted into the second space S2. The second gasket 32 described above is disposed within the end of the second side D2 of the second space S2. In the illustrated example, the horizontal pipe P31 inserted into the second space S2 has a smaller diameter than the horizontal pipe P3 connected to the other horizontal pipe connection portion 14.

As shown in FIG. 3, the blocking portion 53 blocks the first space S1. The blocking portion 53 is provided integrally with the main tube 51 at the first end 51a of the main tube 51. The blocking portion 53 is also provided integrally with the first end 52a of the partition wall 52. The blocking portion 53 is formed in a plate shape facing the central axis C1 (in the illustrated example, a plate shape perpendicular to the central axis C1). The outer peripheral edge of the blocking portion 53 is connected to the first surface 52f of the partition wall 52 and the inner peripheral surface 51f of the main tube 51.

As shown in FIG. 4, the first space S1 is provided with a reinforcing rib 56 that connects the first surface 52f of the partition wall 52 and the inner circumferential surface 51f of the main tube 51. Multiple reinforcing ribs 56 (three in the illustrated example) are provided at intervals in the circumferential direction around the central axis C2. A first end of the reinforcing rib 56, located on the first side D1 in the direction of the central axis C1, is connected to the blocking portion 53.

As shown in FIG. 3, the partition wall 52 has a protruding wall 54 at its first end 52a, which is located on the first side D1 in the direction of the central axis C1, that protrudes into the second space S2. The protruding wall 54 is located on the opposite side of the partition wall 52 from the blocking portion 53. The tip of the horizontal tube P31 inserted into the second space S2 abuts against the protruding wall 54.

The protruding portion 55 protrudes from the second surface 52g of the partition wall 52 into the second space S2. The protruding portion 55 has a plurality of protrusions 55A. Each protrusion 55A is provided at intervals in the circumferential direction (three in the illustrated example). Each protrusion 55A is not formed over the entire length of the main tube 51 in the direction of the central axis C1, but is formed only on a portion of the main tube 51 in the direction of the central axis C1. In the illustrated example, the protrusion 55A is formed so as to be eccentric to the first side D1 of the main tube 51. The protrusion 55A extends continuously from the protruding wall 54 in the direction of the central axis C1.

At the tip 55s of the protrusion 55A located on the second side D2, the protrusion height (overhang height) from the second surface 52g of the partition wall 52 gradually decreases from the first side D1 toward the second side D2. The end face of the tip 55s is inclined with respect to the central axis C2 in a vertical cross section including the central axis C2. As a result, when the horizontal tube P31 is inserted into the second space S2, the protrusion 55A (overhang 55) guides the horizontal tube P31 toward the central axis C2.

As shown in FIG. 3, the second end 51b of the main tube 51 is an expanded diameter section 59. The expanded diameter section 59 is larger than the portion of the main tube 51 located on the first side D1 than the expanded diameter section 59. As shown in FIG. 4, a flat surface 60 is formed on the expanded diameter section 59 at a portion facing the partition wall 52 across the central axis C2.

As shown in Figure 5, the flat surface 60 is formed by cutting out a portion of the outer peripheral surface of the expanded diameter portion 59 (main tube 51). The flat surface 60 is formed by making a portion of the main tube 51 around the central axis C1 thinner than the other portions. Note that the flat surface 60 is not limited to a structure in which a portion of the main tube 51 is actually cut out; it may be formed by designing a mold so that the flat surface 60 is formed during injection molding.

Convex portions 57 and 58 are formed on the outer circumferential surface of the main body pipe 51. The convex portions 57 and 58 are located closer to the first side D1 than the expanded diameter portion 59.
The protrusion 57 engages with a recess (not shown) formed in the horizontal pipe connecting portion 14A. By engaging with the recess, the protrusion 57 determines the position of the bushing 50 around the central axis C1 relative to the horizontal pipe connecting portion 14A.
The protrusion 58 engages with a recess 73 of the eccentric ring 70, which will be described later. By engaging with the recess, the protrusion 58 determines the position of the eccentric ring 70 relative to the bush 50 around the central axis C1.

As shown in FIGS. 1 and 5, the bush 50 uses an eccentric ring 70 as the second ring 33, as will be described below.
The eccentric ring 70 integrally includes a main ring 72 and an eccentric flange 71 .
The second end 51b of the main tube 51 is inserted into the main ring 72. A recess 73 that opens toward the first side D1 is formed in a part of the circumferential direction of the main ring 72.

The eccentric flange 71 is formed in an annular shape and protrudes from the inner circumferential surface at the end of the second side D2 of the main ring 72. The eccentric flange 71 abuts against the second end 51b of the main tube 51 and presses against the second gasket 32. The outer circumferential surface of the eccentric flange 71 is coaxial with the central axis C1. The inner circumferential surface of the eccentric flange 71 is coaxial with the central axis C2 and is eccentric with respect to the central axis C1.

The eccentric ring 70 has a flat portion 74 formed at a position corresponding to the flat surface 60 when the eccentric ring 70 is attached to the bush 50 (when the eccentric ring 70 is positioned around the central axis C1 by the convex portion 58).
The flat portion 74 is formed by cutting out a portion of the main ring 72. The portion of the main ring 72 where the flat portion 74 is formed is missing, and an opening 74a is formed in this portion. The flat surface 60 is exposed to the outside from the flat portion 74. Note that the flat portion 74 is not limited to a structure in which it is actually formed by cutting out a portion of the eccentric ring 70, and may be formed by designing a mold so that the flat portion 74 is formed during injection molding.

As shown in FIG. 1, the bushing 50 is inserted into the horizontal pipe connection portion 14A with the first space S1 positioned above and the second space S2 positioned below. That is, with the bushing 50 positioned around the central axis C1 relative to the horizontal pipe connection portion 14A by the protrusion 57, the first space S1 is positioned above the second space S2. With the bushing 50 inserted into the horizontal pipe connection portion 14A (with the bushing 50 positioned around the central axis C1 by the protrusion 57), the flat surface 60 and flat portion 74 are positioned at their lowest ends.

In the above-mentioned bushing 50, the horizontal pipe P31 is inserted into the second space S2 from the second side D2 in the direction of the central axis C1. Here, the protruding portion 55 is provided only on the first end 52a of the partition wall 52. Therefore, on the second side D2, which is closer to the protruding portion 55, the inner diameter (cross-sectional area) of the second space S2 is larger than the outer diameter of the horizontal pipe P31. Therefore, when starting to insert the horizontal pipe P31 into the second space S2, the horizontal pipe P31 can be easily inserted into the bushing 50.

When the horizontal tube P31 is inserted into the second space S2 toward the first side D1 and reaches the tip 55s of the protrusion 55A, the tip of the horizontal tube P31 is guided by the inclined tip 55s between the multiple protrusions 55A and the inner surface 51g of the main tube 51. When the tip of the horizontal tube P31 abuts against the protruding wall 54, the horizontal tube P31 is sandwiched and held between the multiple protrusions 55A (extending portions 55) and the inner surface 51g of the main tube 51.

Here, the second space S2 is offset downward with respect to the central axis C2 of the horizontal pipe connection portion 14A. Therefore, the position of the horizontal pipe P31 can be lowered to a position closer to the floor slab S. This makes it easier to ensure, for example, a water gradient in the horizontal pipe P31.
Furthermore, the eccentric ring 70 and the bushing 50 are formed with a flat portion 74 and a flat surface 60. This allows the eccentric ring 70 and the bushing 50 to be lowered to a position close to the floor slab S. This makes it easier to ensure a water gradient in the horizontal pipe P31, for example.

As explained above, the bushing 50 according to this embodiment is placed between the horizontal pipe connection portion 14A of the manifold 10 and the horizontal pipe P31, which have different diameters, and connects them after adjusting the difference in diameter between them. The horizontal pipe connection portion 14A of the manifold 10 can be connected to the horizontal pipe P31 by inserting the main pipe 51 into the horizontal pipe connection portion 14A and inserting the horizontal pipe P31, which has a smaller diameter than the horizontal pipe connection portion 14A, into the second space S2.

The protruding portion 55 protrudes into the second space S2. Therefore, by increasing or decreasing the protruding dimension of the protruding portion 55 into the second space S2, the cross-sectional area (inner diameter) of the second space S2 can be increased or decreased while fixing the position and shape of the partition wall 52. This allows for design freedom regarding the position and shape of the partition wall 52, while also allowing for the formation of a second space S2 that can accommodate horizontal pipes P31 of various sizes.

However, for example, when manufacturing the bushing 50 using a mold, the shape of the first space S1 or the second space S2 (the shape of the partition wall 52) may restrict the direction in which the mold can be removed from the first space S1 or the second space S2. Due to this restriction, the position of the closure portion 53 in the direction of the central axis C1 may be limited depending on the position and shape of the partition wall 52. In some cases, it may be necessary to form the closure portion 53 as a separate member from the main tube 51 and attach the closure portion 53 to the main tube 51 later.

However, this bushing 50 allows for greater freedom in the design of the partition wall 52. Therefore, even while the closure portion 53 and the main tube 51 are integrally molded, the position of the closure portion 53 in the direction of the central axis C1 is less likely to be restricted, allowing for greater freedom in the position of the closure portion 53 in the direction of the central axis C1. As a result, the closure portion 53 can be positioned at the end of the main tube 51 in the direction of the central axis C1. This, for example, simplifies manufacturing while restricting the inflow of external fluid into the first space S1.

A blocking portion 53 is provided at the first end 51a of the main tube 51. This prevents fluid from flowing into the first space S1 from the first side D1.

The overhanging portion 55 has a plurality of protrusions 55A. Therefore, the overhanging portion 55 can be formed by increasing the thickness of the portion of the partition wall 52 where the overhanging portion 55 is provided only in the portion corresponding to the protrusions 55A. Therefore, the portion of the partition wall 52 that is to be thickened can be limited to a narrow range.
When the bushing 50 is injection molded using a resin or rubber material, sink marks in the material tend to occur in thicker portions, which can lead to poor quality. However, by partially providing the protruding portions 55 (protrusions 55A) while maintaining the thickness of the partition wall 52, for example, it is possible to prevent sink marks and other problems from occurring during molding. As a result, the bushing 50 can be manufactured more easily.

The protruding portion 55 is provided only on a portion of the main tube 51 in the direction of the central axis C1. Therefore, when inserting the end of the horizontal tube P31 into the second space S2, excessive frictional resistance generated at the contact point between the horizontal tube P31 and the protruding portion 55 can be prevented. This makes it easy to connect the horizontal tube P31 to the second space S2.

(First Modification of the Embodiment)
In the above embodiment, only the tip 55s of the protrusion 55A in the direction of the central axis C2 is inclined, and in other parts, the protrusion dimension of the protrusion 55A from the second surface 52g of the partition wall 52 is constant, but the present invention is not limited to this.
As shown in Figure 6, the protrusion 55B constituting the protrusion portion 55 of the bushing 50B of this modified example may be formed so that the protrusion dimension from the second surface 52g of the partition wall 52 gradually increases along the direction of the central axis C2 from the second side D2 of the main tube 51 toward the first side D1.

(Second Modification of the Embodiment)
In the above embodiment, the reinforcing ribs 56 are provided on the opposite sides of the partition wall 52 from the plurality of protrusions 55A, but the present invention is not limited to this.
7 and 8, the inner diameter of the second space S2 of the bushing 50C of this modified example is larger than that of the bushing 50 of the above embodiment. A protrusion 55C is provided on the circumferential end 52e of the partition wall 52C (the portion where the partition wall 52C joins with the main pipe 51).

(Third Modification of the Embodiment)
In the above embodiment, the bushing 50 is provided with three protrusions 55A, but the number of protrusions is not limited thereto.
For example, like a bushing 50D of this modified example shown in FIG. 9, two protrusions 55D may be provided spaced apart in the circumferential direction.

(Fourth Modification of the Embodiment)
In the above embodiment, the blocking portion 53 is provided integrally with the main body tube 51 at the first end 51a of the main body tube 51, but the present invention is not limited to this.
10 , the upper end of the blocking portion 53 may be provided in the center of the main tube 51 in the direction of the central axis C1. In this bushing 50E, the blocking portion 53 extends downward toward the first side D1 and is inclined with respect to the direction of the central axis C1. The lower end of the blocking portion 53 is connected to the first end 52 a of the partition wall 52.
Because the blocking portion 53 is inclined as described above, even if sewage or the like enters the first space S1 from the first side D1, the sewage will not remain in the first space S1 but will be discharged from the first space S1 to the first side D1.
In this modification, the blocking portion 53 does not protrude outward along the central axis C1 from the main pipe 51 or the partition wall 52. Therefore, even if the blocking portion 53 is inclined as described above, the size of the bushing 50E can be reduced.

(Fifth Modification of the Embodiment)
Furthermore, for example, like a bushing 50F of this modified example shown in FIG. 11, the blocking portion 53 may extend downward toward the second side D2.

(Sixth Modification of the Embodiment)
In the above embodiment, the protruding portion 55 includes a plurality of protrusions 55A, but the present invention is not limited to this.
For example, as in a bushing 50G of this modified example shown in Figures 12 and 13, the protruding portion 55 may be formed by a single protrusion 55G. The circumferential size of the protrusion 55G is smaller than the circumferential size of the above-mentioned protrusion 55A, and is, for example, about half the circumferential size of the entire partition wall 52.

(Seventh Modification of the Embodiment)
Furthermore, for example, as in a bushing 50H of this modified example shown in FIG. 14 , a lightening portion S3 may be formed in the partition wall 52. The lightening portion S3 is provided in the circumferential portion of the partition wall 52 where the protrusion 55G (protruding portion 55) is provided. The lightening portion S3 opens toward the first side D1 along the central axis C1. In the lightening portion S3, the radial size, which is a direction perpendicular to the central axis C2, gradually increases toward the first side D1. In other words, in this modified example, the partition wall 52 is divided into two portions in the radial direction from the center portion along the central axis C1 toward the first side D1. Of the two divided portions of the partition wall 52, the outer portion located on the radially outer side forms the first space S1, and the inner portion located on the radially inner side forms the second space S2. The inner portion protrudes radially inward compared to the other circumferential portion that forms the second space S2.

(Eighth Modification of the Embodiment)
The upper connecting pipe 11 and the lower connecting pipe 12 may be fitted with sound insulating covers (not shown) that cover the outer circumferential surfaces of each pipe.

For example, a sheet (not shown) may be wrapped around the upper connecting pipe 11 as a sound-insulating cover. Such a sheet may be made of a sheet of elastic material such as modified asphalt, elastomer, rubber, polyolefin resin, or soft polyvinyl chloride resin. The sheet may also contain inorganic materials such as calcium carbonate or barium sulfate, metal sheets such as iron or lead, or metal powder.

Furthermore, for example, the lower connecting pipe 12 may be provided with a pipe body made of sound-insulating material as a sound-insulating cover (not shown). The sheet body is integrally molded, for example, by injection molding, pressure molding, blow molding, vacuum forming, or the like. The sheet body is formed from an elastic resin material such as an olefin-based material (a resin composition containing 300 to 600 parts by weight of inorganic filler per 100 parts by weight of olefin-based resin).

The inorganic filler is not particularly limited, but examples include silica, diatomaceous earth, alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, ferrites, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dawnnite, hydrotalcite, calcium sulfate, barium sulfate, gypsum fiber, calcium silicate, talc, clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber, glass beads, silica-based balun, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon balun, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, zinc borate, various magnetic powders, slag fiber, fly ash, and dewatered sludge. Of these, calcium carbonate is preferably used as the inorganic filler from the perspective of balancing weight and cost. These may be used alone or in combination of two or more.

The olefin-based resin is not particularly limited, but examples include low-density polyethylene, high-density polyethylene, linear low-density polyethylene, atactic polypropylene, isotactic polypropylene, syndiotactic polypropylene, and poly-α-olefin. Among these, polyethylene with a density of 0.87 to 0.93 g/cm ³ is preferred as the olefin-based resin. If the density is less than 0.87 g/cm ³ , the strength of the tube is insufficient. If the density exceeds 0.93 g/cm ³ , the tube may buckle when flattened (when an axial force is applied to the tube). Furthermore, if the flexural modulus of the olefin-based resin is 100 to 3,000 kg/cm ² , the strength and windability are sufficient. The tube may be formed from a material other than the olefin-based material, such as polyvinyl chloride resin, polystyrene resin, ABS resin, AS resin, or an elastomer material.

The technical scope of the present invention is not limited to the above-described embodiment and its variations, and various modifications can be made without departing from the spirit of the present invention.

The protruding portion 55 is provided only at the first end portion 52 a of the partition wall 52. However, for example, the protruding portion 55 may be provided only at the central portion along the central axis C1 of the partition wall 52. For example, the protruding portion 55 may be provided over the entire length of the partition wall 52.
The flat surface 60 and the flat portion 74 may be omitted.

The bushing 50 may be provided at other pipe connection parts such as the vertical pipe connection part 13 .
The bushing 50 may be provided at a plurality of horizontal pipe connection portions 14 .

In addition, 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, without departing from the spirit of the present invention.

1 Joint section (joint structure)
10. Collective joint 14A: Horizontal pipe connection part (pipe connection part)
50A, 50B, 50C, 50D, 50E, 50F, 50G, 50H Bush 51 Main tube 52, 52C Partition wall 55 Protruding portion 55A, 55B, 55C, 55D, 55G Projection C1 Central axis P31 Horizontal tube (tube body)
S1 First space S2 Second space

Claims (4)

a main body pipe having an expanded diameter portion and a flat surface on the outer surface of the expanded diameter portion facing the floor slab ;
a partition wall provided within the main body pipe, the partition wall dividing the inside of the main body pipe into a first space and a second space in a cross section intersecting a central axis of the main body pipe;
a closing portion that closes the first space;
a protruding portion protruding from the partition wall into the second space ,
The protruding portion is a bush having a plurality of protrusions . The bushing described in claim 1, wherein the blocking portion is provided at the end of the main tube in the central axis direction. 3. The bushing according to claim 1, wherein the protruding portion is provided only in a portion of the partition wall along the central axis of the main pipe. a joint assembly having a pipe connection portion to which an end of a pipe body is connected;
A joint structure comprising: the bushing according to any one of claims 1 to 3 , which is provided in the pipe connection portion.