Pipe joint and piping system

Abstract

To provide a pipe joint hardly deteriorating heat insulation performance, and a piping system using the pipe joint.SOLUTION: The pipe joint includes a joint body part 10 formed in a pipe shape, and at least two socket parts 11 integrally formed on an 10a of an opening part of the joint body part 10 and capable of connecting by inserting a pipe member 20 being the other pipe, and the socket parts 11 have a pipe abutting surface 11a on which an end surface 21 of the inserted pipe member 20 abuts. This pipe joint X has a swelling part 12 formed to swell from an outer surface 11a, on the outer surface 11a of a joint body part 10 corresponding to an area over a pipe abutting surface 11b and a separate position P2 separated to the side of an end part 10b of a socket part 11 by a predetermined set distance s from the pipe abutting surface 10b, and this piping system uses the pipe joint X.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pipe joint for connecting a plurality of pipe members and a piping system. [Background technology]

[0002] Drain water generated by an air conditioner installed indoors is typically discharged outdoors using a drain piping structure for air conditioning equipment that has anti-condensation measures in place. The drain piping is formed by appropriately connecting a drain pipe (for example, a pipe with a foam layer and a structure that improves thermal insulation performance) and a pipe fitting (such as an elbow or a tee) from the air conditioner to the outlet. For example, when constructing this drain piping structure, in order to connect the air conditioner's drain port to a flexible hose, the upstream side (air conditioner side) of the drain pipe connected to the air conditioner's drain port and the flexible hose are connected using a pipe fitting such as an elbow fitting or a tee fitting.

[0003] Patent Documents 1 and 2 disclose that a pipe joint is provided with a heat insulating layer to prevent drainage from accumulating and forming condensation at the connection portion of the pipe joint.

[0004] That is, Patent Document 1 discloses a joint having a tubular joint body and a connecting part that is integrally formed at the opening of the joint body and is connected to another pipe, the joint body being composed of non-foamed layers on the outer and inner surfaces and a foamed layer (thermal insulating layer) formed between the outer and inner surfaces, and the connecting part being composed without a foamed layer.

[0005] Patent Document 2 discloses a pipe fitting comprising a cylindrically formed fitting body and a socket portion connected to the fitting body, in which the fitting body is provided with a hollow layer (thermal insulating layer). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6953293 [Patent Document 2] Patent No. 7389604 Summary of the Invention [Problem to be solved by the invention]

[0007] When inserting another pipe component into the receiving port of a pipe fitting, there was a risk of a gap occurring between the end face of the pipe component and the pipe abutment surface (stopper) that the end face of the inserted pipe component abuts against due to insufficient insertion of the pipe component or beveling of the end face of the pipe component.

[0008] In addition, the pipe member is inserted into the socket of the pipe fitting and adhesively joined with an adhesive. At this time, if the holding time during bonding is insufficient, the inserted pipe member may slip back out due to the tapered shape of the socket, which is configured with at least the draft angle required for molding, and a gap (for example, about 2 mm) may occur between the pipe abutment surface and the end face of the pipe member.

[0009] The areas where the above-mentioned gaps are likely to occur are near the pipe abutment surface of the socket portion of the pipe fitting, where there is no insulating layer or the thickness is thinner than the fitting body, so the insulating performance is inferior to that of the fitting body. Therefore, when the above-mentioned gaps occur, the insulating performance of the pipe fitting (drain piping) decreases in the gap area (the connection portion of the pipe fitting), and there is a risk of condensation occurring.

[0010] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pipe joint that has a simple structure and is less likely to experience a decrease in heat insulating performance, and a piping system that uses the pipe joint. [Means for solving the problem]

[0011] A first characteristic feature of the pipe fitting of the present invention for achieving the above-mentioned object is that it comprises a tubular fitting main body, and at least two socket portions formed integrally with the opening of the fitting main body and into which other pipe members can be inserted to connect, wherein the socket portions have pipe abutment surfaces against which the end faces of the inserted pipe members abut, and a bulge portion formed to bulge from the outer surface of the fitting main body corresponding to a region spanning the pipe abutment surfaces and a spaced apart position a predetermined set distance from the pipe abutment surface towards the end of the socket portions.

[0012] With this configuration, the bulge can increase the thickness of the fitting body corresponding to the pipe-contacting surface of the socket, and can also increase the thickness of the socket corresponding to the spaced apart position, thereby improving the thermal insulation performance of the pipe fitting in the area where the bulge is formed.

[0013] Here, if the predetermined set distance is set to the distance of a gap that may occur between the pipe abutment surface and the end face of the pipe member, even if a gap occurs between the pipe abutment surface and the end face of the pipe member, the heat insulating performance of the pipe fitting is less likely to deteriorate because a bulge with improved heat insulating performance is formed in the area extending from the pipe abutment surface to a position spaced a predetermined set distance (gap distance) toward the end of the socket. Thus, with this configuration, a pipe fitting that is less likely to cause condensation can be provided.

[0014] Furthermore, by providing the bulge portion on the outer surface of the joint body, the strength of the joint body can be improved.

[0015] In addition, by providing a bulge portion on the outer surface of the fitting main body, the position of the pipe abutment surface can be easily recognized, so that the approximate position (position from the end face) of the pipe member to be inserted into the receiving portion can be determined before inserting the pipe member.

[0016] Furthermore, by providing the bulge portion, it becomes easy to distinguish it from other joints for other uses that do not have a bulge portion, and the bulge portion acts as a non-slip barrier for the hand, making handling easier and improving workability.

[0017] In this configuration, the provision of the bulge portion makes it possible to provide a pipe fitting that is less likely to lose its thermal insulation performance, and therefore it is possible to provide a pipe fitting with a simple structure that is less likely to lose its thermal insulation performance.In addition, because the structure is simple, no assembly or other processes are required, and the pipe fitting can be provided at low cost.

[0018] A further characteristic feature of the pipe fitting according to the present invention is that the thickness of the cross section of the bulge portion, i.e., the thickness of the bulge portion wall, is made thicker than the thickness of the receiving portion wall, i.e., the thickness of the cross section of the end of the receiving portion.

[0019] According to this configuration, the thickness of the bulge portion can be set thicker than the thickness of the end of the receiving portion, thereby reliably improving the insulation performance of the bulge portion, and even if a gap occurs between the pipe abutment surface and the pipe member, the insulation performance of the pipe fitting is less likely to deteriorate.

[0020] A further characteristic feature of the pipe fitting according to the present invention is that the cross-sectional shape of the bulge portion has an arc-shaped surface centered at a position corresponding to the outer periphery of the pipe abutment surface and having a radius equal to the thickness of the bulge portion, and also has an arc-shaped surface centered at the separated position and having a radius equal to the thickness of the bulge portion.

[0021] In this configuration, the cross-sectional shape of the bulge portion can be formed by an arc-shaped surface (first arc-shaped surface) centered at a position corresponding to the outer periphery of the pipe abutting surface and having a radius equal to the thickness of the bulge portion, an arc-shaped surface (second arc-shaped surface) centered at the separated position and having a radius equal to the thickness of the bulge portion, and a connecting surface connecting the first arc-shaped surface and the second arc-shaped surface. In this way, in this configuration, the cross-sectional shape of the bulge portion can be suitably defined.

[0022] A further characteristic feature of the pipe joint according to the present invention is that the joint body is formed from polyvinyl chloride.

[0023] According to this configuration, the joint body can be manufactured at low cost.

[0024] A further characteristic feature of the pipe joint according to the present invention is that the joint body is formed from a transparent material.

[0025] This configuration makes it easy to visually check the connection (bonding) state of the pipe members at the receiving port from the outside. In addition, because the pipe fitting has a difference in thickness between the bulge around the pipe contact surface and the receiving port, when molded from a single transparent material, the transparency of these areas varies, creating a gradation. This makes it easy to check installation, for example, whether the insertion length of the pipe member is within the appropriate range.

[0026] A further characteristic feature of the pipe joint according to the present invention is that the outer surface of the joint body is provided with a textured surface.

[0027] By providing a textured surface as in this configuration, even if condensation occurs on the outer surface of the joint body, the condensation is less likely to drip.

[0028] A further characteristic feature of the pipe joint according to the present invention is that the resin material that is the main material constituting the joint body is blended with a material that has a lower thermal conductivity than the resin material.

[0029] According to this configuration, the thermal conductivity of the joint body can be reduced, thereby improving the heat insulating performance of the pipe joint.

[0030] A further characteristic feature of the pipe joint according to the present invention is that the pipe member is a drainage pipe for an air conditioner.

[0031] According to this configuration, the drainage pipe constituting the drain piping structure of the air conditioner can be used as the pipe member. Therefore, by connecting such a pipe member to the pipe joint of this configuration, It is possible to provide a drain piping structure in which the heat insulating performance is less likely to deteriorate and condensation is less likely to occur.

[0032] A characteristic configuration of the piping system according to the present invention is that it uses the above-described pipe joint.

[0033] According to this configuration, a piping system in which condensation is unlikely to occur can be provided by using pipe joints whose heat insulating performance is unlikely to deteriorate. [Brief explanation of the drawings]

[0034] [Figure 1] 1 is a cross-sectional view showing a pipe joint (elbow joint) of an embodiment. [Figure 2] 1A to 1C are plan views (front view, right side view, left side view, top view, and bottom view) showing a pipe joint (elbow joint) of an embodiment. [Figure 3] FIG. 4 is a cross-sectional view showing a pipe joint (tee joint) of another embodiment 1. [Figure 4] 10A to 10C are plan views (front view, right side view, left side view, top view, and bottom view) showing a pipe joint (tee joint) of Alternative Example 1. [Figure 5] FIG. 10 is a cross-sectional view showing a pipe joint (Y-joint) according to a second modified embodiment. [Figure 6] 10A to 10C are plan views (front view, right side view, left side view, top view, and bottom view) showing a pipe joint (Y-shaped joint) of another embodiment 2. [Figure 7] FIG. 10 is a cross-sectional view showing a pipe joint (socket joint) according to a third modified embodiment. [Figure 8] 10A to 10C are plan views (front view, right side view, left side view, top view, and bottom view) showing a pipe joint (socket-type joint) of Alternative Example 3. [Figure 9] FIG. 10 is a cross-sectional view showing a pipe joint (socket joint) according to a fourth modified embodiment. [Figure 10] 10A to 10C are plan views (front view, right side view, left side view, top view, and bottom view) showing a pipe joint (socket-type joint) of Alternative Example 4. [Figure 11] FIG. 10 is a cross-sectional view showing a pipe joint (elbow joint) according to a fifth modified embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0035] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in Figures 1 and 2, the pipe fitting X of the present invention comprises a tubular fitting body 10 and at least two socket portions 11 formed integrally with an opening 10a of the fitting body 10, into which another pipe member 20 can be inserted for connection. The socket portions 11 have a pipe abutment surface 11a against which an end face 21 of the inserted pipe member 20 abuts, and are provided with a bulge portion 12 formed to bulge from the outer surface 10b of the fitting body 10, corresponding to a region spanning the pipe abutment surface 11a and a separation position P2 spaced a predetermined set distance s from the pipe abutment surface 11a toward the end 11b of the socket portions 11.

[0036] The thickness of the cross section of the bulge 12, that is, the bulge thickness t2, is thicker than the socket thickness t1, that is, the thickness of the cross section of the end 11b of the socket 11. The cross section is a cut surface of a plane parallel to the axis O of the socket 11.

[0037] The pipe joint X is a joint for connecting different pipe members 20, which are other pipes. The pipe member 20 can be, for example, a drain drainage pipe constituting the drain piping structure of an air conditioner, but is not limited thereto. Such a pipe member 20 can be, for example, a drain pipe connected to the drain port of an air conditioner or a flexible hose, but is not limited thereto. The drain pipe is not particularly limited as long as it is a pipe through which a fluid can flow, but for example, a multi-layer pipe made of polyvinyl chloride resin can be used. When connecting pipe members 20, the upstream sides (air conditioner side) of the drain pipe and flexible hose are connected by the pipe joint X. These pipe joints X may connect pipe members 20 of the same diameter or pipe members 20 of different diameters.

[0038] The pipe joint X may be in any form as long as it can connect different pipe members 20 together, such as, but not limited to, an L-shaped elbow joint, a T-shaped tee joint, a Y-shaped Y joint, or a socket-type joint. In this embodiment, the pipe joint X is an elbow joint, and the pipe member 20, which is another pipe, is used as a drainage pipe. The elbow joint is L-shaped and changes the direction of the flow path by approximately 90°. The angle of change may be an inclination angle (e.g., 1.17 degrees) relative to the axis O of the receiving portion 11. In this case, the angle of change α is 91.17°, but the angle is not limited to this value.

[0039] The fitting body 10 has a tubular exterior and is configured so that drainage generated by an air conditioner flows down through a tubular flow path 15 formed inside. The material constituting the fitting body 10 is not particularly limited, but a synthetic resin composition, for example, is preferable. Examples of the synthetic resin composition include, but are not limited to, polyvinyl chloride resin (PVC), polypropylene resin (PP), polyethylene resin (PE), and acrylonitrile-butadiene-styrene resin (ABS). The synthetic resin composition can be selected appropriately depending on required performance, such as thermal insulation performance and cost. For example, molding the fitting body 10 from a single material, polyvinyl chloride resin, is preferable because it eliminates the need for disassembly and separation during recycling. Furthermore, if the drain pipe is made of polyvinyl chloride resin, there is no need to disassemble the pipe fitting X and the drain pipe during recycling, and therefore there is no need to remove the joint between them.

[0040] The synthetic resin composition can contain a material having a lower thermal conductivity than the resin material that is the main component.

[0041] Examples of low thermal conductivity materials include, but are not limited to, rubbers such as styrene-butadiene rubber (SBR), known foaming agents, rubber, and charcoal. When blending SBR with PVC, taking recyclability into consideration, it is preferable to use 1 to 10 parts of SBR per 100 parts of PVC, but this is not a limitation. It is recommended to blend these materials at a ratio of, for example, 1 to 10 parts per 100 parts of the main resin material.

[0042] This configuration can reduce the thermal conductivity of the joint body 10, thereby improving the heat insulating performance of the pipe joint X.

[0043] The joint body 10 can be formed from a transparent synthetic resin composition. In this specification, "transparency" means that the synthetic resin composition, which is the material of the joint body 10, has a transparency that allows viewing from one side to the other, and means that the synthetic resin composition has a visible light transmittance of, for example, 30% or more, and more preferably 70% or more. The visible light transmittance can be measured in a conventional manner using a known spectrophotometer.

[0044] If the synthetic resin composition is transparent as in this configuration, the connection state (bonding state) of the pipe member 20 in the receiving portion 11 can be easily visually confirmed from the outside by adhesively joining it with, for example, a colored adhesive.

[0045] The fitting body 10 may have a foamed layer (insulating layer) formed thereon (not shown). The foamed layer may be formed over the entire pipe fitting, or the outer and / or inner surfaces may be non-foamed layers. In this case, the fitting body 10 may be configured with non-foamed layers on the outer and inner surfaces and a foamed layer formed between the outer and inner surfaces. The foamed layer may be formed by adding a known foaming material (such as microcapsules) to the main material, or may be a foamable resin.

[0046] The socket portion 11 is formed integrally with the opening 10a of the joint body 10, and its structure is not particularly limited as long as it allows the tubular member 20 to be inserted and connected. In this embodiment, the socket portion 11 is described as being cylindrical so that the tubular member 20 can be inserted. The inner diameter of the socket portion 11 is set to be larger than the outer diameter of the tubular member 20 so that the tubular member 20 can be inserted. In this case, it is preferable that the inner diameter of the socket portion 11 is large enough to hold the inserted tubular member 20 without rattle.

[0047] In this embodiment, the pipe fitting X (elbow fitting) will be described as having two sockets 11. The inner diameters of the two sockets 11 may be the same or different. In this embodiment, the case where the inner diameters of the two sockets 11 are the same will be described.

[0048] The receiving portion 11 has a pipe abutment surface 11a against which the end face 21 of the inserted pipe member 20 abuts. That is, the pipe abutment surface 11a is formed at the innermost part of the cylindrical receiving portion 11 so that the entire or almost the entire end face 21 can abut against it. The surface shape of the pipe abutment surface 11a (the shape as seen from the opening 10a side) may be configured to match or approximately match the surface shape of the end face 21 of the abutting pipe member 20. The inner diameter d1 of the receiving portion 11 is set larger than the diameter d (inner diameter) of the flow path 15 by the amount corresponding to the formation of the pipe abutment surface 11a in the receiving portion 11.

[0049] The end 11b of the socket portion 11 forms the outer periphery of the opening 10a of the joint body 10. The socket portion thickness t1, which is the cross-sectional thickness of the end 11b of the socket portion 11, is set to be smaller than the joint body thickness t, which is the thickness of the joint body 10. The outer diameter D of the socket portion 11 is the sum of the inner diameter d1 of the socket portion 11 and the socket portion thickness t1 (D = d1 + 2t1).

[0050] The bulge 12 is formed to bulge from the outer surface 10b of the joint body 10. The bulge 12 is formed on the outer surface 10b of the joint body 10 corresponding to a region spanning from the pipe abutting surface 11a to a separation position P2 that is separated from the pipe abutting surface 11a by a predetermined set distance s toward the end 11b of the socket portion 11. It is sufficient that the bulge 12 is formed at least at a position on the outer surface 10b that corresponds to this region.

[0051] The shape of the bulge 12 is not particularly limited as long as it is formed to bulge from the outer surface 10b of the joint body 10, and it may be in a form that protrudes convexly from the outer surface 10b. The bulge 12 may also be formed up to the end 11b of the socket portion 11.

[0052] In this embodiment, the bulge 12 is described as having a portion that gradually protrudes outward from the outer surface 10b of the joint body 10 and a portion that gradually becomes equal in thickness to the end 11b of the socket 11 toward the end 11b. However, the shape of the bulge 12 is not limited to this. Specific shapes will be described later.

[0053] With this configuration, the bulge 12 can increase the thickness of the fitting body 10 corresponding to the pipe abutment surface 11a of the socket 11, and can also increase the thickness of the socket 11 corresponding to the separation position P2. This improves the heat insulating performance of the pipe fitting X in the area where the bulge 12 with increased thickness is formed.

[0054] In this specification, the "wall thickness" (bulge wall thickness t2) refers to the distance (thickness) from position P1 (or spaced position P2) corresponding to the outer periphery of the pipe abutment surface 11a to the outer surface of the bulge 12 in the cross-sectional shape of the bulge 12.

[0055] As described above, when inserting the pipe member 29 into the socket portion 11 of the pipe fitting X, there is a risk of a gap occurring between the pipe abutment surface 11a and the end face 21 of the pipe member 20. Therefore, the predetermined set distance s should be set to the distance of a gap that may occur between the pipe abutment surface 11a and the end face 21 of the pipe member 20.

[0056] As a result, even if a gap occurs between the pipe abutment surface 11a and the end face 21 of the pipe member 20, the bulge 12 with improved thermal insulation performance is formed in the region extending from the pipe abutment surface 11a to the separation position P2, which is separated by the predetermined set distance s (gap distance) toward the end 11b of the socket portion 11, so that the thermal insulation performance of the pipe fitting X is unlikely to deteriorate. Therefore, with this configuration, it is possible to provide a pipe fitting X that is resistant to condensation.

[0057] Furthermore, by providing the bulging portion 12 on the outer surface 10b of the joint body 10, the strength of the joint body 10 can be improved.

[0058] Furthermore, by providing the bulge portion 12 on the outer surface 10b of the fitting main body portion 10, the position of the pipe abutment surface 11a can be easily recognized, and therefore, before inserting the pipe member 20, it is possible to determine the approximate position (position from the end face 21) of the pipe member 20 to be inserted into the receiving portion 11.

[0059] Since the pipe joint X of this embodiment has two socket portions 11, it is preferable to provide each of the socket portions 11 (11A, 11B) with a bulge portion 12 (12A, 12B).

[0060] By providing a plurality of (two) bulging portions 12 (12A, 12B) in this manner, the strength of the hand main body portion 10 can be further improved.

[0061] The wall 13 between the two bulges 12 has a uniform thickness (wall thickness t of the fitting body). The pipe fitting X (elbow fitting) of this embodiment is L-shaped, and the inner peripheral wall 14 located at the inner corner of the L shape is configured so that the two bulges 12 (12A, 12B) are close to each other. This improves the strength of the inner peripheral wall 14, which is known to be easily cracked.

[0062] The thickness of the cross section of the bulging portion 12, ie, the bulging portion thickness t2, is preferably set to be thicker than the thickness of the cross section of the end portion 11b of the socket portion 11, ie, the socket portion thickness t1.

[0063] This allows the thickness of the bulge portion 12 to be set thicker than the thickness of the end portion 11b of the receiving portion 11, thereby reliably improving the insulating performance of the bulge portion 12. For example, even if a gap occurs between the pipe abutment surface 11a and the pipe member 20, the insulating performance of the pipe fitting X is less likely to deteriorate.

[0064] In this embodiment, the sizes of the above-mentioned components are set as follows, but are not limited to these dimensions. Diameter d of flow path 15: 19 to 100 mm Fitting body thickness t 5.5~20mm Socket wall thickness t1 2.5~5.0mm Bulging part thickness t2 5.5~20mm (set so that t2>t1) Inner diameter d1 of socket 11: 32 to 115 mm Outer diameter D of socket 11: 39~125mm Setting distance s 0.1~3.0mm Depth L of socket 11: 15 to 50 mm Thickness T of the pipe member 20: 5.5 to 15 mm

[0065] It is preferable that the thickness t2 of the bulge portion is set to be equal to the thickness t of the joint body portion. This allows the heat insulating performance of the bulge portion 12 to be equal to the heat insulating performance of the joint body portion 10.

[0066] In this embodiment, the cross-sectional shape of the bulge portion 12 is described as having an arc-shaped surface (first arc surface) 121 centered at position P1 corresponding to the outer periphery of the pipe abutment surface 11a and having a radius equal to the bulge portion thickness t2, and also having an arc-shaped surface (second arc surface) 122 centered at the separation position P2 and having a radius equal to the bulge portion thickness t2 (Figure 1).

[0067] In this configuration, the cross-sectional shape of the bulge portion 12 can be formed by a first arcuate surface 121, a second arcuate surface 122, and a connecting surface 123 connecting the first arcuate surface 121 and the second arcuate surface 122. The first arcuate surface 121 gradually protrudes outward from the outer surface 10b of the fitting body 10, and the second arcuate surface 122 gradually becomes equal in thickness to the end 11b of the socket portion 11 toward the end 11b. The cross-sectional shape of the connecting surface 123 can be linear or arcuate, but is not limited to these. By making the cross-sectional shape of the connecting surface 123 linear, the bulge portion thickness t2 in this portion can be uniform.

[0068] This configuration allows the cross-sectional shape of the bulging portion 12 to be defined.

[0069] The outer surface 10b of the joint body 10 may be textured. The textured surface may be formed by a known process, such as a chemical process such as etching or a physical process such as sandblasting. The textured surface may be formed on the entire outer surface 10b or only on a portion thereof.

[0070] By providing a textured surface as in this configuration, even if condensation occurs on the outer surface 10b of the joint body 10, it is possible to make it difficult for the condensation to drip.

[0071] For example, a (drain) piping system (not shown) for an air conditioning system can be provided using the above-described pipe joint X. The piping system can be constructed in such a way that condensation is unlikely to occur by using the above-described pipe joint X, which is unlikely to deteriorate in heat insulation performance.

[0072] [Another Example 1] In the above-described embodiment, the pipe joint X is an elbow joint, but the invention is not limited to this, and the pipe joint X may be a T-shaped tee joint (FIGS. 3 and 4).

[0073] A tee joint is a pipe joint that joins or branches flow paths, and in this embodiment, a case will be described in which it has three sockets 11 (11A1, 11B1, 11C1). In this case, sockets 11A1, 11B1, 11C1 each have a bulge 12A1, 12B1, 12C1, respectively.

[0074] The tubular inner flow path 15 branches into two flow paths 15A1 and 15B1. Two bulging portions 12 (12A1 and 12C1) are adjacent to each other on the inner circumferential wall portion 14A1, and two bulging portions 12 (12B1 and 12C1) are adjacent to each other on the inner circumferential wall portion 14B1.

[0075] In this embodiment, the angle at which the flow paths merge or branch may be an angle (e.g., 1.17 degrees) for gradient with respect to the axis O of the receiving port 11. For example, when drain flows from the top to the bottom of the paper, the two flow paths 15A1 and 15B1 can be configured to intersect at an angle β (91.17 degrees). The angle is not limited to this value.

[0076] [Another Example 2] In the above-described embodiment, the pipe joint X is described as being in the form of an elbow joint or a tee joint, but this is not limiting, and the pipe joint X can also be a Y-shaped joint (FIGS. 5 and 6).

[0077] The Y-joint is a pipe joint that joins or branches flow paths, and in this embodiment, a case will be described in which it has three sockets 11 (11A2, 11B2, 11C2). In this case, sockets 11A2, 11B2, 11C2 each have a bulge 12A2, 12B2, 12C2, respectively.

[0078] The tubular internal flow path 15 branches into two flow paths 15A2 and 15B2. In this embodiment, the angle γ at which the flow paths merge or branch is 45° relative to the axis O of the receiving portion 11, but the angle is not limited to this.

[0079] [Another Example 3] In the above-described embodiment, the pipe joint X is described as an elbow joint, a tee joint, or a Y-joint, but is not limited thereto, and the pipe joint X can also be a socket-type socket joint (FIGS. 7 and 8).

[0080] A socket-type joint is a pipe joint that connects flow paths in a straight line, and in this embodiment, a case where it is used to connect pipe members 20 of the same diameter will be described.

[0081] In this embodiment, a case will be described in which two sockets 11 (11A3, 11B3) are provided. In this case, sockets 11A3, 11B3 are provided with bulging portions 12A3, 12B3, respectively. In this case, bulging portions 12A3, 12B3 can be formed as an integrated unit.

[0082] The tubular inner flow path 15 is a linear flow path formed by connecting two flow paths 15A3 and 15B3.

[0083] [Another Example 4] In the above-described third alternative embodiment, the pipe joint X may be a socket joint that connects pipe members 20 of different diameters (FIGS. 9 and 10).

[0084] In this embodiment, the inner diameter of socket portion 11A3 in Alternative Embodiment 3 is smaller than the inner diameter of socket portion 11B3, and accordingly, the outer diameter of bulging portion 12A3 is set smaller than the outer diameter of bulging portion 12B3.

[0085] [Alternative Example 5] As shown in FIG. 11, a low-conductivity portion 16 having a lower thermal conductivity than the resin material may be provided at a location on the side of the socket portion 11 of the joint body 10 having the bulge portion 12.

[0086] The low-conductivity portion 16 may be made of a material having a lower thermal conductivity than, for example, a resin material, such as, but not limited to, sponge or foam rubber.

[0087] Figure 11 shows a case where the low-conductivity portion 16 has a low-conductivity portion 16A on the side of the socket portion 11 of the joint main body 10 having the bulge portion 12A, and a low-conductivity portion 16B on the side of the socket portion 11 of the joint main body 10 having the bulge portion 12B.

[0088] The low conductive portion 16 can be formed by removing a region of the joint body 10 corresponding to the location where the low conductive portion 16 is to be formed, and then disposing the above-mentioned material in the removed region.

[0089] If the above-mentioned material is not placed in the removed area, when the pipe member 20 is inserted into the socket 11, the low-conductivity portion 16B can become an air layer.

[0090] The low-conductivity portion 16 may be formed inside the joint body 10 (between the outer surface of the bulge 12 and the inner wall of the socket 11).

[0091] By providing the low conductive portion 16, the heat insulating performance of the pipe joint X is less likely to deteriorate, and a pipe joint that is less likely to cause condensation can be provided.

[0092] If the low-conductivity portion 16 is made of, for example, foam rubber, when the pipe member 20 is inserted into the socket 11, the frictional force between the outer surface of the pipe member 20 and the foam rubber at the contact point makes it difficult for the pipe member 20 to come out of the socket 11. In this case, there is no need to use an adhesive to bond the pipe member 20 in the socket 11, which reduces the cost of using adhesive and eliminates the step of bonding using an adhesive.

[0093] The above-described embodiment is an example, and the present invention is not limited to this, and can be arbitrarily modified in accordance with the spirit of the present invention. [Industrial Applicability]

[0094] INDUSTRIAL APPLICABILITY The present invention can be used in a pipe joint that connects a plurality of pipe members in a drain piping structure, and in a piping system that uses the pipe joint. [Explanation of symbols]

[0095] X fitting s Setting distance P2 Separate position t1 Socket wall thickness t2 Thickness of bulging part 10. Joint body 10a opening 10b Outer surface 11 Socket 11a Pipe contact surface 11b End 12 Bulge 20 Pipe members 21 End face

Claims

1. The coupling includes a tubular body and at least two sockets formed integrally with an opening of the coupling body, into which other pipe members can be inserted for connection; the receiving portion has a pipe abutment surface against which an end face of the inserted pipe member abuts, A pipe fitting comprising a bulge formed on the outer surface of the fitting body corresponding to a region spanning the pipe abutment surface and a spaced apart position spaced a predetermined set distance from the pipe abutment surface toward the end of the receiving portion, the bulge being formed so as to bulge from the outer surface.

2. 2. A pipe joint according to claim 1, wherein a thickness of the cross section of said bulging portion, that is, a thickness of said bulging portion, is greater than a thickness of the cross section of the end of said socket portion, that is, a thickness of the socket portion.

3. 3. The pipe fitting according to claim 2, wherein the cross-sectional shape of the bulge portion has an arc-shaped surface centered at a position corresponding to the outer periphery of the pipe abutment surface and having a radius equal to the thickness of the bulge portion, and also has an arc-shaped surface centered at the separated position and having a radius equal to the thickness of the bulge portion.

4. 3. A pipe joint according to claim 1, wherein the joint body is made of polyvinyl chloride.

5. 3. A pipe joint according to claim 1, wherein the joint body is made of a transparent material.

6. 3. A pipe joint according to claim 1, wherein the outer surface of the joint body is provided with a textured surface.

7. 3. A pipe joint according to claim 1, wherein the resin material that is the main material constituting the joint body contains a material having a lower thermal conductivity than the resin material.

8. 3. A pipe joint according to claim 1, wherein the pipe member is a drainage pipe for an air conditioner.

9. A piping system using the pipe joint according to claim 1.

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