Pipe fitting and pipe fitting attachment structure

Abstract

A pipe fitting 10 fixed to an attachment pipe 12 includes: a tubular part 14; and a pair of elastic locking parts 40 locked to the attachment pipe 12. The tubular part 14 has: a first pipe part inserted into the attachment pipe 12; and a second pipe part 32 extending in a direction crossing the central axis of the first pipe part. The pair of elastic locking parts 40 are disposed facing each other on opposite sides of the second pipe part 32 when viewed in the axial direction of the second pipe part 32, and overlap the second pipe part 32 in the axial direction of the first pipe part.

Description

Pipe joint and pipe joint mounting structure

[0001] The present invention relates to a pipe joint to be attached to an attachment pipe and to an attachment structure thereof.

[0002] Patent Document 1 discloses a coupling including a fluid duct having a first opening and a second opening and bending at a right angle, and a locking device provided in the area of ​​the first opening of the fluid duct. The locking device locks onto the coupling portion of the fluid line, thereby attaching the coupling to the fluid line. The locking device is provided on the fluid line side of a receiving structure located in the area of ​​the second opening.

[0003] Special table 2019-530839 publication

[0004] In the technique disclosed in Patent Document 1, the locking device is provided in the region of the first opening, so the region of the first opening in the fluid duct becomes long and the fluid duct becomes large.

[0005] An object of the present invention is to provide a technique that can reduce the size of a pipe joint that is attached to an attachment pipe.

[0006] In order to solve the above problems, one aspect of the present invention is a pipe fitting fixed to an attachment pipe, comprising a tubular portion and a pair of elastic locking portions that lock onto the attachment pipe. The tubular portion has a first pipe portion that is inserted into the attachment pipe and a second pipe portion that extends in a direction intersecting the central axis of the first pipe portion. The pair of elastic locking portions are arranged opposite each other with the second pipe portion therebetween when viewed along the axial direction of the second pipe portion, and are arranged so as to overlap with the second pipe portion in the axial direction of the first pipe portion.

[0007] Another aspect of the present invention is a pipe joint attachment structure. This pipe joint attachment structure includes an attachment pipe and a pipe joint fixed to the attachment pipe. The pipe joint has a tubular portion including a first pipe portion inserted into the attachment pipe and a second pipe portion extending from the first pipe portion in a direction intersecting the central axis of the first pipe portion, and a pair of elastic locking portions that lock onto the attachment pipe. The attachment pipe has a recess formed by cutting out an opening edge and into which a portion of the second pipe portion fits.

[0008] According to the present invention, a technique can be provided that allows the size of a pipe joint attached to an attachment pipe to be reduced.

[0009] 1A is a perspective view of a pipe joint mounting structure according to a first embodiment; FIG. 1B is a perspective view of a pipe joint and an attachment pipe according to a first embodiment; FIG. 3A is a top view of a tubular portion, and FIG. 3B is a side view of the tubular portion; FIG. 4A is a perspective view of a retainer, and FIG. 4B is a front view of the retainer; FIG. 4B is a cross-sectional view of the pipe joint mounting structure along the central axis of the second pipe portion; FIG. 4C is a cross-sectional view of the pipe joint mounting structure as viewed in a direction along the central axis of the second pipe portion; FIG. 5A is a perspective view of a pipe joint according to a second embodiment; FIG. 5B is a top view of a tubular portion according to a second embodiment, and FIG. 5C is a side view of the tubular portion according to a second embodiment; FIG. 5C is a perspective view of a retainer according to a second embodiment; FIG. 5D is a front view of a retainer according to a second embodiment; FIG. 5E is a cross-sectional view of an attachment pipe and a pipe joint, showing a state before the pipe joint is attached to the attachment pipe; and FIG. 5F is a partial cross-sectional view for explaining the operation of the pipe joint.

[0010] Fig. 1 is a perspective view of a pipe joint mounting structure 1 of the first embodiment. Fig. 2 is a perspective view of a pipe joint 10 and an attachment pipe 12 of the first embodiment. The pipe joint mounting structure 1 is composed of the pipe joint 10 and the attachment pipe 12.

[0011] The pipe joint mounting structure 1 is provided in a heat exhaust path of a vehicle and exhausts, for example, high-temperature, high-pressure gas. The heat exhaust path is located under the floor of the vehicle compartment, and is therefore limited in height and size. Note that the pipe joint mounting structure 1 is not limited to use in heat exhaust paths, and may also be used in cooling paths that move cooling fluid.

[0012] The pipe fitting 10 is fixed to an attachment pipe 12. The attachment pipe 12 opens upward. The attachment pipe 12 includes an opening 19, a locking portion 20, an opening edge 22, and a recess 24. A pair of locking portions 20 are formed on the outer circumferential surface of the attachment pipe 12, forming a step that protrudes in the radial direction. This step may be formed so as to protrude from the outer circumferential surface of the attachment pipe 12, or may be formed so as to be recessed from the outer circumferential surface of the attachment pipe 12.

[0013] The opening edge 22 is formed in an arc shape at the upper end of the attachment pipe 12, and a pair of recesses 24 are formed to be spaced apart. The recesses 24 are formed by cutting out the opening edge 22, and a pair of recesses 24 are formed opposite each other. The recesses 24 are recessed further than the opening edge 22 and curved in an arc shape. By fitting the pipe fitting 10 into the recesses 24, the amount by which the pipe fitting 10 protrudes upward from the attachment pipe 12 can be reduced.

[0014] The pipe joint 10 includes a tubular portion 14, a retainer 16, and a sealing member 18. The tubular portion 14 will be described with reference to Fig. 3, and the retainer 16 will be described with reference to Fig. 4.

[0015] 3(a) is a top view of the tubular portion 14, and Fig. 3(b) is a side view of the tubular portion 14. The tubular portion 14 is formed in a T-shape when viewed from the side, and has a first tubular portion 30, a boundary portion 31, a second tubular portion 32, a frame-shaped portion 34, and a flange portion 36.

[0016] The first pipe portion 30 is formed in a cylindrical shape. A groove portion 30a is formed in the outer peripheral surface of the first pipe portion 30 along the circumferential direction. The first pipe portion 30 is inserted into the attachment pipe 12 through the opening 19. A seal member 18 fits into the groove portion 30a. The seal member 18 may be, for example, an O-ring.

[0017] As shown in FIG. 3( b), the boundary portion 31 is located at the upper end of the first pipe portion 30 and is formed in an annular shape. The boundary portion 31 connects the first pipe portion 30 and the second pipe portion 32. The boundary portion 31 is coaxial with the first pipe portion 30. The boundary portion 31 is formed in an annular shape, and although FIG. 3( b) shows an embodiment in which the boundary portion 31 is cylindrical, the boundary portion 31 is not limited to this embodiment and may be bent up and down. The boundary portion 31 is positioned so as not to extend above the central axis of the second pipe portion 32.

[0018] The second pipe portion 32 extends from the boundary portion 31 in a direction intersecting the central axis of the first pipe portion 30. More preferably, the second pipe portion 32 extends in a direction perpendicular to the central axis of the first pipe portion 30. The pipe fitting 10 is configured by connecting a cylindrical first pipe portion 30 and a cylindrical second pipe portion 32 via the boundary portion 31, and the first pipe portion 30 refers to the portion that extends downward from the cylindrical second pipe portion 32.

[0019] A pair of frame-shaped portions 34 are formed to protrude laterally from the second pipe portion 32. The pair of frame-shaped portions 34 protrude in opposite directions to each other and extend in the same direction. The frame-shaped portion 34 includes a pair of column portions extending parallel to each other from the second pipe portion 32 and a suspension portion that suspends the pair of column portions. The frame-shaped portion 34 opens along the axial direction of the first pipe portion 30. Each of the pair of frame-shaped portions 34 has an engaging portion 34a. The engaging portion 34a is located on the suspension portion of the frame-shaped portion 34. The seat portion 34b is formed flat at a position connecting the pair of frame-shaped portions 34, and is capable of seating the retainer 16.

[0020] A pair of flange portions 36 are provided, sandwiching the first pipe portion 30 and the frame-shaped portion 34, and protrude radially outward from the outer circumferential surface of the second pipe portion 32. The flange portions 36 have a flat portion 36a on their upper surfaces. The flat portion 36a is formed so as not to protrude above the retainer 16.

[0021] 4(a) is a perspective view of the retainer 16, and FIG. 4(b) is a front view of the retainer 16. The retainer 16 has an elastic locking portion 40, a connecting portion 42, and an engaged portion 44.

[0022] The elastic locking portions 40 are formed as a pair facing each other. The connecting portion 42 connects the base ends of the pair of elastic locking portions 40. The portion of the elastic locking portion 40 that connects to the connecting portion 42 is referred to as the base end, and the lower end of the elastic locking portion 40 in FIG. 4(b) is referred to as the tip. The elastic locking portion 40 has a claw portion 40a and a thin portion 40b. The claw portion 40a is formed so as to protrude inward from the inner surface of the elastic locking portion 40. The inner surface of the elastic locking portion 40 is the surface where the pair of elastic locking portions 40 face each other. The thin portion 40b is located closer to the base end than the claw portion 40a and is easily flexible so as to spread the claw portion 40a.

[0023] The engaged portion 44 is formed to protrude from the outer surface of the elastic locking portion 40. The engaged portion 44 is located closer to the base end of the elastic locking portion 40 than the thin-walled portion 40b, i.e., closer to the connecting portion 42 of the elastic locking portion 40 than the thin-walled portion 40b. The portion of the elastic locking portion 40 where the engaged portion 44 is formed is thicker than the thin-walled portion 40b, making it less likely to deform and expand. The engagement position between the tubular portion 14 and the retainer 16 can be adjusted so that the engaged portion 44 does not protrude above the connecting portion 42. Furthermore, by locating the engaged portion 44 on the connecting portion 42 side of the elastic locking portion 40, the expanding movement of the elastic locking portion 40 when the claw portion 40a engages is less likely to be obstructed. The engaged portion 44 is located closer to the first pipe portion 30 than the connecting portion 42 and lower than the upper end of the second pipe portion 32.

[0024] The connecting portion 42 has a protruding portion 42a and an arc-shaped portion 42b. The protruding portion 42a protrudes to widen the central portion of the connecting portion 42. The outer surface, i.e., the surface, of the connecting portion 42 is formed flat. The protruding portion 42a increases the area of ​​the connecting portion 42, making it easier for an operator to press the connecting portion 42 when installing the pipe fitting 10. The arc-shaped portion 42b recesses the inner surface of the connecting portion 42. The arc-shaped portion 42b is formed to a shape that matches the central portion 38 of the second pipe portion 32. The arc-shaped portion 42b rests on the central portion 38.

[0025] 5 is a cross-sectional view of the pipe joint mounting structure 1 taken along the central axis C2 of the second pipe portion 32. The central axis C2 of the second pipe portion 32 is perpendicular to the central axis C1 of the first pipe portion 30. The first pipe portion 30 and the second pipe portion 32 are in communication with each other. The connecting portion 42 and the recessed portion 24 are located between the pair of flange portions 36. The protruding portion 42a protrudes so as to be close to the flange portions 36.

[0026] The flange portion 36 and the connecting portion 42 are at approximately the same height, and the connecting portion 42 does not protrude above the flange portion 36. This allows the height of the pipe joint 10 to be reduced.

[0027] 6 is a cross-sectional view of the pipe joint mounting structure 1 as viewed in a direction along the central axis C2 of the second pipe portion 32. The elastic locking portion 40 is inserted into the frame-shaped portion 34, and the engaged portion 44 is engaged with the engaging portion 34a. The engaging portion 34a prevents the retainer 16 from coming off the tubular portion 14. As a result, even when the elastic locking portion 40 expands, the frame-shaped portion 34 presses the engaged portion 44 from the outside, making it difficult for the engaged portion 44 and the engaging portion 34a to come off engagement with each other.

[0028] The arc-shaped portion 42b of the connecting portion 42 rests on the central portion 38 of the second pipe portion 32. The pair of elastic locking portions 40 are arranged opposite each other across the second pipe portion 32 when viewed along the axial direction of the second pipe portion 32, and extend from the second pipe portion 32 side across the boundary portion 31 to the first pipe portion 30 side. In other words, the elastic locking portion 40 extends from the second pipe portion 32 above the first pipe portion 30 and is arranged so as to overlap with the second pipe portion 32 in the axial direction of the first pipe portion 30. The elastic locking portion 40 hangs down from a position above the central axis C2 of the second pipe portion 32 and is spaced apart from the first pipe portion 30. This ensures a sufficient length of the elastic locking portion 40, making the elastic locking portion 40 more flexible and reducing the force required to attach it to the mounting pipe 12. Furthermore, since the elastic locking portion 40 is positioned radially outward from the first pipe portion 30, the entire first pipe portion 30 can be inserted into the mounting pipe 12, making it possible to set the axial length of the first pipe portion 30 to be short.

[0029] The engaged portion 44 is formed on the outer surface of the base end side of the elastic locking portion 40, but is not limited to this. For example, it may be formed on the outer surface of the connecting portion 42. In either case, the engaged portion 44 is formed on the outer surface of the retainer 16 so as not to protrude above the surface of the connecting portion 42.

[0030] The retainer 16 is formed separately from the tubular portion 14, and the elastic locking portion 40 is formed separately from the tubular portion 14. This allows the elastic locking portion 40 to bend from the position of the connecting portion 42, ensuring the length of the elastic locking portion 40 and making it easy to bend.

[0031] The installation procedure for the pipe fitting 10 and the attachment pipe 12 will now be described. As shown in Figure 2, the worker aligns the first pipe section 30 of the pipe fitting 10 with the opening 19 of the attachment pipe 12 and pushes the connecting section 42 toward the attachment pipe 12. This inserts the first pipe section 30 into the attachment pipe 12 until a portion of the second pipe section 32 enters the recess 24, and the claw section 40a of the elastic locking section 40 locks with the locked section 20. This attaches the pipe fitting 10 to the attachment pipe 12. The worker can easily install the pipe fitting 10 by simply pushing the connecting section 42. Furthermore, because the second pipe section 32 enters the recess 24 in the attached state, the amount by which the pipe fitting 10 protrudes from the attachment pipe 12 is reduced, allowing the pipe fitting installation structure 1 to be made more compact.

[0032] 7 is a perspective view of a pipe joint 110 of the second embodiment. The pipe joint 110 of the second embodiment differs from the pipe joint 10 shown in FIG.

[0033] The pipe joint 110 includes a tubular portion 114, a retainer 116, and a seal member 18. While the tubular portion 14 shown in Fig. 1 is T-shaped, the tubular portion 114 is formed in an L-shape.

[0034] 8(a) is a top view of the tubular portion 114, and Fig. 8(b) is a side view of the tubular portion 114. The tubular portion 114 has a first tubular portion 130, a second tubular portion 132, a frame-shaped portion 134, a circumferential protrusion 135, a flange portion 136, a support portion 137, a central portion 138, and an abutment surface 139.

[0035] The first pipe portion 130 is formed in a cylindrical shape and is inserted into the attachment pipe. A groove portion 130a is formed on the outer peripheral surface of the first pipe portion 130. The seal member 18 is fitted in the groove portion 130a. The boundary portion 31 shown in FIG. 8(b) is located at the upper end of the first pipe portion 130 and is formed in an annular shape. The boundary portion 31 connects the first pipe portion 130 and the second pipe portion 132. The boundary portion 31 is coaxial with the first pipe portion 130.

[0036] The second pipe portion 132 extends from the boundary portion 31 in a direction intersecting the central axis of the first pipe portion 130. A pair of frame-shaped portions 134 are formed so as to protrude laterally from the second pipe portion 132. The pair of frame-shaped portions 134 protrude in opposite directions to each other.

[0037] The frame-shaped portion 134 has an engaging portion 134a and a slit 134b. The engaging portion 134a prevents the retainer 116 from coming off the tubular portion 114. The slit 134b penetrates the center of the engaging portion 134a. The slit 134b allows the frame-shaped portion 134 to be expandable, making it easier to assemble the retainer 116.

[0038] The support portion 137 forms a seat surface that is flush with the upper end surface of the flange portion 136 and supports the protruding portion 152 of the retainer 116. The central portion 138 is located at the center inside the frame-shaped portion 134 and is lower than the frame-shaped portion 134.

[0039] The pair of circumferential protrusions 135 are formed to protrude in the circumferential direction on the outer circumferential surface of the second tubular portion 132. The circumferential protrusions 135 are in close proximity to or in contact with the inner surface of the attachment pipe, thereby suppressing rattling of the tubular portion 114 relative to the attachment pipe.

[0040] The pair of abutment surfaces 139 are located above the circumferential protrusion 135 at a height overlapping with the frame-shaped portion 134, and are formed on the outer surface of the second pipe portion 132. The abutment surfaces 139 form flat side surfaces on the curved outer surface of the second pipe portion 132.

[0041] Fig. 9 is a perspective view of the retainer 116. Fig. 10 is a front view of the retainer 116. The retainer 116 has elastic locking portions 140, connecting portions 142, engaged portions 144, wall portions 146, recessed portions 148, downward protrusions 150, and overhanging portions 152. The connecting portions 142 connect the base ends of the pair of elastic locking portions 140. The connecting portions 142 are connected to the overhanging portions 152.

[0042] The engaged portion 144 is formed to protrude from the outer surface of the elastic locking portion 140. The engaged portion 144 is located closer to the base end of the elastic locking portion 140 than the thin portion 140b. The engaged portion 144 is formed in a shape that tapers downward.

[0043] The wall portion 146 stands upright from the recessed portion 148 along the outer surface of the elastic locking portion 140. The wall portion 146 abuts against the frame-shaped portion 134 to prevent rattle. The recessed portion 148 is recessed further than the wall portion 146. The recessed portion 148 makes the connecting portion 142 more flexible.

[0044] The downward protrusions 150 are formed to protrude from the lower surface of the connecting portion 142. The pair of downward protrusions 150 are positioned opposite each other and each have a flat opposing surface. The overhanging portion 152 is formed in a flat plate shape and is provided on the connecting portion 142.

[0045] The elastic locking portions 140 are formed as a pair facing each other. The elastic locking portions 140 have a locking portion 140a, a thin portion 140b, a contact surface 140c, and a fulcrum portion 140d. The fulcrum portion 140d is located at the base end of the elastic locking portion 140 and below the protruding portion 152. The connecting portion 142 is connected to the protruding portion 152, so it has high rigidity, and the elastic locking portions 140 bend with the fulcrum portion 140d as a base point. In other words, the fulcrum portion 140d serves as a fulcrum when the pair of elastic locking portions 140 expand.

[0046] The locking portion 140a is formed in a claw shape at a position extending from the fulcrum portion 140d and closer to the tip of the fulcrum portion 140d. The locking portion 140a locks onto the attachment tube. The abutment surface 140c is located between the locking portion 140a and the fulcrum portion 140d and is formed on the inner surface of the downward protrusion 150. The abutment surface 140c abuts against the abutted surface 139 formed on the tubular portion 114.

[0047] 11 is a cross-sectional view of the attachment pipe 112 and the pipe joint 110, showing the state before the pipe joint 110 is attached to the attachment pipe 112. The attachment pipe 112 has a locking portion 20, an opening edge 22, a recess 24, and an inclined surface 126. The locking portions 20 are formed as a pair on the outer circumferential surface of the attachment pipe 112 and protrude radially outward.

[0048] The inclined surface 126 is formed around the circumferential direction on the inner surface of the attachment pipe 112, and constitutes a step that is inclined so as to increase in diameter toward the opening edge 22. The inclined surface 126 makes the opening side of the attachment pipe 112 larger in diameter, making it easier to insert the pipe fitting 110.

[0049] The pair of elastic locking portions 140 are arranged opposite each other across the second pipe portion 132 when viewed along the axial direction of the second pipe portion 132, and are arranged so as to overlap with the second pipe portion 132 in the axial direction of the first pipe portion 130.

[0050] The engaging portion 134a of the frame-shaped portion 134 engages with the engaged portion 144, restricting the movement of the retainer 116 toward release. The wall portion 146 is formed so that the engaging portion 134a does not protrude above the frame-shaped portion 134 when it abuts against the engaged portion 144, and is in contact with or close to the frame-shaped portion 134.

[0051] The pair of abutting surfaces 140c abut against the pair of abutted surfaces 139 so as to sandwich them. In other words, the retainer 116 is held by the tubular portion 114 in a state in which the frame-shaped portion 134 and the elastic locking portions 140 are in contact with each other. This makes it possible to prevent the retainer 116 from moving in the opposing direction of the elastic locking portions 140.

[0052] 11 , the pipe fitting 110 is being attached to the attachment pipe 112, with the upper end of the attachment pipe 112 positioned inside the pair of elastic locking portions 140. The pair of elastic locking portions 140 abut against the outer surface of the attachment pipe 112. Because the inner surface of the upper portion of the attachment pipe 112 has a larger diameter due to the inclined surface 126, the first pipe portion 130 and the seal member 18 can be smoothly inserted into the attachment pipe 112.

[0053] Figure 12 is a partial cross-sectional view illustrating the operation of the pipe fitting 110. Note that the seal member 18 is omitted from Figure 12. Figure 12(a) is a view showing the pipe fitting 110 in the middle of being attached to the attachment pipe 112, with the first pipe section 130 slightly inserted inside the attachment pipe 112 and the elastic locking section 140 abutting against the outer surface of the attachment pipe 112.

[0054] 12(b) shows the state in which the pipe fitting 110 has been pushed into the attachment pipe 112 and the elastic locking portion 140 has been expanded to its maximum extent. The elastic locking portion 140 expands from the fulcrum portion 140d as a base point in order to pass over the locked portion 20. At this time, the abutting surface 140c moves away from the abutting surface 139 when the pipe fitting 110 is attached to the attachment pipe 112. Therefore, the elastic locking portion 140 expands from the fulcrum portion 140d, making it more flexible, and the insertion force required when attaching the pipe fitting 110 can be reduced.

[0055] 12(c) shows the state in which the pipe fitting 110 in the attached state is subjected to a force to be removed from the attachment pipe 112. The tubular portion 114 receives a force F1 in the removal direction due to the fluid pressure inside the attachment pipe 112, and pushes up the connecting portion 142 of the retainer 116.

[0056] As the connecting portion 142 is pushed up, the locking portion 140a attempts to disengage from the locked portion 20, but as the fulcrum portion 140d is pushed upward, a torque acting inward in the opposing direction is generated at the tip of the elastic locking portion 140. Furthermore, the frame-shaped portion 134 restricts the expansion of the elastic locking portion 140, so that the elastic locking portion 140 receives an inward force F2 acting in the opposing direction from the frame-shaped portion 134. As a result, the abutting surface 140c is pressed against the abutted surface 139. When the pipe fitting 110 receives a force F1 in the direction of removal from the attachment pipe 112, the abutting surface 140c abuts against the abutted surface 139. As a result, the elastic locking portion 140 attempts to bend in a short portion, starting from the abutting surface 140c, making it difficult to bend. This increases the removal force of the pipe fitting 110. In this way, the pipe fitting 110 can reduce the insertion force and increase the removal force by switching between contact and non-contact between the abutting surface 140c and the abutted surface 139 during insertion and removal.

[0057] 11 , the pair of contact surfaces 140c are provided at a distance greater than the inner diameter of the second tube portion 132 when viewed in the direction of the central axis of the second tube portion 132. The inner diameter of the second tube portion 132 is the diameter of the inner surface 132a of the second tube portion 132. This allows the contact surfaces 140c to be positioned sufficiently far from the fulcrum portion 140d, making it difficult for the elastic locking portion 140 to bend when removed.

[0058] The abutting surface 140c is positioned so as to overlap the engaged portion 144 when viewed in the opposing direction of the pair of elastic locking portions 140. The abutting surface 140c is positioned so as to overlap the inner surface 132a of the second tube portion 132 when viewed in the opposing direction of the pair of elastic locking portions 140. This allows the abutting surface 140c to be positioned farther away from the fulcrum portion 140d than when the abutting surface 140c is positioned above the inner surface 132a, making it possible to make the elastic locking portion 140 less likely to bend when removed.

[0059] The present invention is not limited to the above-described embodiments, and various modifications such as design changes may be made to the embodiments based on the knowledge of those skilled in the art, and such modified embodiments may also be included within the scope of the present invention.

[0060] In the embodiment, the tubular portion 14 is formed in a T-shape, but this is not limiting. For example, the tubular portion 14 may be formed in an L-shape and there may be one second tubular portion 32. In either case, the tubular portion 14 has a first tubular portion 30 and a second tubular portion 32 extending in a direction intersecting the central axis of the first tubular portion 30. When the tubular portion 14 is L-shaped, there may be one recess 24 formed in the attachment tube 12. Alternatively, the tubular portion 114 may be formed in a T-shape.

[0061] Furthermore, in the embodiment, the tubular portion 14 and the retainer 16 that constitute the pipe joint 10 are separate bodies, but this is not limiting. For example, if a pair of elastic locking portions 40 are provided on the tubular portion 14, they can be formed as a single unit. The pair of elastic locking portions 40 extend from the second pipe portion 32 toward the first pipe portion 30. The pair of elastic locking portions 40 are arranged opposite each other with the second pipe portion 32 therebetween when viewed along the axial direction of the second pipe portion 32, and extend from the second pipe portion 32 side to the first pipe portion 30 side.

[0062] The present invention relates to a pipe joint to be attached to an attachment pipe and to an attachment structure thereof.

[0063] REFERENCE SIGNS LIST 1 Pipe joint mounting structure, 10 Pipe joint, 12 Mounting pipe, 14 Tubular portion, 16 Retainer, 18 Sealing member, 19 Opening, 20 Locked portion, 22 Opening edge, 24 Recess, 30 First pipe portion, 30a Groove portion, 31 Boundary portion, 32 Second pipe portion, 34 Frame-shaped portion, 34a Engaging portion, 34b Seat portion, 36 Flange portion, 36a Flat portion, 38 Central portion, 40 Elastically locking portion, 42 Connecting portion, 44 Engaged portion.

Claims

1. A pipe fitting fixed to an attachment pipe, comprising: a tubular portion; and a pair of elastic locking portions that lock onto said attachment pipe, wherein said tubular portion has a first pipe portion that is inserted into said attachment pipe; and a second pipe portion that extends in a direction that intersects with the central axis of said first pipe portion, and wherein the pair of elastic locking portions are arranged opposite each other with said second pipe portion therebetween when viewed along the axial direction of said second pipe portion, and are arranged so as to overlap with said second pipe portion in the axial direction of said first pipe portion.

2. A pipe fitting as described in claim 1, further comprising a retainer formed separately from the tubular portion and having a pair of the elastic locking portions, the tubular portion having an engaging portion that prevents the retainer from coming off the tubular portion, the retainer having a connecting portion that connects the pair of elastic locking portions and is placed on the second pipe portion, and an engaged portion that engages with the engaging portion.

3. A pipe fitting as described in claim 2, characterized in that the engaged portion is formed on the outer surface of the elastic locking portion or on the outer surface of the connecting portion at a position on the connecting portion side of the elastic locking portion, the tubular portion has a pair of frame-shaped portions each having the engaging portion, the frame-shaped portions protrude from the second pipe portion so as to open in the axial direction of the first pipe portion, and the elastic locking portion is inserted into the frame-shaped portions.

4. The pair of elastic locking portions each have a fulcrum portion that serves as a fulcrum when the pair of elastic locking portions expand, a locking portion that is formed further towards the tip than the fulcrum portion and locks onto the attachment pipe, and an abutment surface that is located between the locking portion and the fulcrum portion and abuts against an abutment surface formed on the tubular portion, and the abutment surface moves away from the abutment surface when the pipe fitting is attached to the attachment pipe, and abuts against the abutment surface when the pipe fitting is subjected to a force that removes it from the attachment pipe.

5. A pipe fitting as described in claim 4, characterized in that the pair of abutment surfaces are located farther apart than the inner diameter of the second pipe portion when viewed in the direction of the central axis of the second pipe portion.

6. A pipe joint as set forth in claim 4 or 5, characterized in that the abutment surface is positioned so as to overlap the inner surface of the second pipe portion when viewed in the opposing direction of the pair of elastic locking portions.

7. A pipe fitting as claimed in claim 4 or 5, further comprising a retainer formed separately from the tubular portion and having a pair of the elastic locking portions, the tubular portion having a frame-like portion including an engaging portion that prevents the retainer from coming off the tubular portion, the frame-like portion having a slit so that it can be expanded.

8. A pipe joint according to claim 7, wherein the retainer is held on the tubular portion with the frame portion and the elastic engaging portion in contact with each other.

9. A pipe fitting mounting structure comprising: an attachment pipe; and a pipe fitting fixed to said attachment pipe, wherein said pipe fitting has a tubular portion including a first pipe section inserted into said attachment pipe and a second pipe section extending from said first pipe section in a direction intersecting the central axis of said first pipe section; and a pair of elastic locking sections that lock onto said attachment pipe, wherein said attachment pipe has a recess formed by cutting out an opening edge and into which a portion of said second pipe section fits.

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