Pipe joint, pipe connection structure, and pipe connection method

Abstract

To provide a pipe joint, a pipe connecting structure, and a pipe connecting method suitable as a high flow rate pipe joint, capable of suppressing forgetting to mount an in-core, and capable of suppressing cost increase.SOLUTION: The pipe joint includes the seal member 26 and the retaining member 23 that are in contact with the outer peripheral surface of the pipe P, the interior body 27 provided on the inner side of the seal member 26 and the retaining member 23 in the insertion direction of the pipe P, and the in-core 28 including the inner support portion 111 that supports the pipe P from the inner side and the outer disposed portion 112 disposed on the outer side of the distal end of the pipe P. The outside arrangement portion 112 of the in-core 28 is provided with a large diameter portion 121 having an outer diameter larger than an inner diameter of the inside projection 94.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pipe joint, a pipe connection structure, and a pipe connection method. [Background technology]

[0002] For example, in the field of hot and cold water supply, pipe fittings are used to connect pipes. A known pipe fitting structure, as shown in Patent Document 1, houses a seal member in a housing groove provided on the inner circumferential surface of the fitting body, and seals off water by bringing the seal member into contact with the outer surface of the pipe inserted inside the fitting body. Because this type of external watertight fitting seals off water on the outer circumferential surface of the pipe, it is easier to ensure the inner diameter of the pipe and reduce pressure loss due to the connection between the pipe and the pipe fitting, compared to structures that seal off water on the inner surface of the pipe. For this reason, external watertight fittings are in high demand in areas where high flow rates are required, such as in the renovation of apartment buildings.

[0003] This pipe fitting uses a component called an incore, which is inserted inside the pipe as a support member for the pipe to ensure proper insertion. This incore is generally either integrated with the fitting body or molded separately from the fitting body. However, in pipe fittings that require a high flow rate, the inner diameter of the pipe needs to be as large as possible, which requires the incore to be thin-walled. If the incore is made thin-walled, molding it as a single piece increases the difficulty in terms of mold releasability and draft angle, and a certain wall thickness is required, so molding it as a separate component, as shown in Patent Document 1, is desirable.

[0004] Furthermore, since there is a possibility of water leakage due to insufficient insertion of the pipe when connecting the pipes, an inner watertight joint has been developed that makes a sound when the insertion is complete, as shown in Patent Document 2. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-120404 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-075308 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the pipe fitting described in Patent Document 1, the inner core is separate from the fitting body, so there is a possibility that the contractor will forget to attach the inner core when inserting the pipe into the pipe fitting. Also, the pipe fitting described in Patent Document 2 has an inner watertight structure, so it is not suitable for high-flow pipe fittings for renovation fields, which has seen increasing demand in recent years, and two parts are required to produce noise, which increases costs.

[0007] In view of the above-mentioned circumstances, the present invention aims to provide a pipe fitting, a piping connection structure, and a piping connection method that are suitable as a high-flow pipe fitting, can prevent the in-core from being forgotten to be attached, and can prevent costs from increasing. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention proposes the following aspects. <1> A pipe fitting according to one aspect of the present invention comprises: a joint body having an accommodating recess into which a pipe is inserted from one side; a seal member provided in the accommodating recess and in contact with an outer peripheral surface of the pipe to seal between the pipe and the joint body; a retaining member provided in the receiving recess and contacting an outer circumferential surface of the pipe to prevent the pipe from coming out; an inner body provided in the accommodating recess on a deeper side than the sealing member and the retaining member in the insertion direction of the pipe; an in-core having an inner support portion that supports the pipe from the inside and an outer arrangement portion that is arranged axially outward from the tip of the pipe; Equipped with The inner body is provided with an elastically deformable engagement piece having an extension portion extending toward the rear side in the insertion direction and an inner protrusion portion protruding radially inward from an extension tip of the extension portion, The outer placement portion of the in-core is provided with a large diameter portion whose outer diameter is larger than the inner diameter of the inner protrusion and which can be positioned further back in the insertion direction than the inner protrusion.

[0009] <1> This pipe fitting is an external watertight fitting in which a sealing member provided within the accommodating recess of the fitting body contacts the outer surface of the pipe to seal between the pipe and the fitting body, and the inner core that supports the pipe from the inside can be made separate from the fitting body and can be made thin, making it suitable as a high-flow pipe fitting. The inner body is provided on the rear side of the sealing member and the retaining member in the insertion direction of the pipe within the accommodating recess, and is provided with an elastically deformable engaging piece having an extending portion extending rearward in the insertion direction and an inner protruding portion protruding radially inward from the extending tip of the extending portion. The outer arranged portion, which is arranged axially outward of the tip of the pipe of the incore, is provided with a large diameter portion whose outer diameter is larger than the inner diameter of the inner protruding portion and which can be positioned rearward in the insertion direction than the inner protruding portion. Therefore, when a pipe with an incore attached is inserted into the fitting body's recess from one side, the seal member and retaining member contact the outer circumferential surface of the pipe. Further insertion of the pipe causes the large-diameter portion of the incore to push the inner protrusion of the inner body radially outward, elastically deforming the engagement piece radially outward. Further insertion of the pipe causes the large-diameter portion of the incore to be positioned further back in the insertion direction than the inner protrusion, and the inner protrusion of the engagement piece is positioned closer to the inner support portion than the large-diameter portion of the incore. The engagement piece returns from its elastic deformation, and the inner protrusion collides with the incore, generating an installation sound (click). This installation sound lets the installer know that the incore has not been forgotten to be installed. This prevents the incore from being forgotten to be installed. Furthermore, because the incore is used to generate the installation sound, only an additional inner body is required, thereby reducing costs.

[0010] <2> The aforementioned <1> In the pipe joint according to the above aspect, it is preferable that the inner body has a plurality of engaging pieces provided at intervals in the circumferential direction. In this way, since the inner body is provided with a plurality of engaging pieces spaced apart in the circumferential direction, the installation sound can be increased, which further reduces the likelihood of forgetting to install the inner core.

[0011] <3> The pipe connection structure according to one aspect of the present invention is <1> or the above <2> The pipe is connected to the pipe joint according to the above.

[0012] <3> According to this piping connection structure, the pipe fitting is suitable as a high-flow pipe fitting, and therefore suitable for high-flow piping. Furthermore, when a pipe with an inner core attached is inserted into the accommodation recess of the fitting body from one side, the engaging piece of the inner body collides with the inner core, generating an installation sound, allowing the installer to recognize that the inner core has not been forgotten to be installed. Therefore, forgetting to install the inner core can be prevented. Furthermore, because the inner core is used to generate the installation sound, only an additional inner body is required, and cost increases can be suppressed.

[0013] <4> A method for connecting pipes according to one aspect of the present invention comprises the steps of: <1> or the above <2> A piping connection method for connecting the pipe to the pipe joint according to the present invention, a step of inserting the inner support part into the tip part of the pipe to attach the inner core; a step of inserting the pipe with the in-core attached into the accommodating recess of the joint body from one side to bring the sealing member and the retaining member into contact with an outer peripheral surface of the pipe; Further inserting the pipe, and pushing the inner protruding portion of the inner body radially outward with the large diameter portion of the inner core, thereby elastically deforming the engaging piece portion radially outward; further inserting the pipe to position the large diameter portion of the inner core further in the insertion direction than the inner protrusion, and disposing the inner protrusion at a position closer to the inner support portion than the large diameter portion, thereby returning the engagement piece from elastic deformation and causing the inner protrusion to collide with the inner core; Includes.

[0014] <4> According to this method of connecting piping, the inner support part is inserted into the tip of the pipe and the incore is attached, the pipe is inserted into the accommodating recess of the joint body from one side, the sealing member and the anti-slip member are brought into contact with the outer peripheral surface of the pipe, the pipe is further inserted so that the large diameter part of the incore presses the inner protrusion part of the inner body radially outward, causing the engaging piece part to elastically deform radially outward, the pipe is further inserted so that the large diameter part of the incore is positioned further back in the pipe insertion direction than the inner protrusion part, and the inner protrusion part is positioned closer to the inner support part than the large diameter part, thereby causing the engaging piece part to return from elastic deformation and causing the inner protrusion part to collide with the incore. The pipe fitting is suitable as a high-flow pipe fitting, making it suitable for high-flow piping. Furthermore, when a pipe with an inner core attached is inserted into the fitting body's recess from one side, the engaging piece of the inner body collides with the inner core, generating an installation sound, allowing the installer to recognize that the inner core has not been forgotten to be installed. This makes it possible to prevent the inner core from being forgotten to be installed. Furthermore, because the inner core is used to generate the installation sound, only an additional inner body is required, which helps prevent cost increases. [Effects of the Invention]

[0015] As described above, the present invention is suitable as a high flow rate pipe joint, and has the effect of preventing the in-core from being forgotten to be attached and preventing an increase in costs. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a cross-sectional view showing a pipe connection structure including a pipe fitting according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A pipe joint, a pipe connection structure, and a pipe connection method according to an embodiment of the present invention will be described below with reference to the drawings.

[0018] As shown in Fig. 1, a pipe fitting 11 of this embodiment is connected to a pipe P to form a piping connection structure 12. This piping connection structure 12 forms various piping facilities such as waterworks pipes, drainage pipes (sewer pipes), gas pipes, and air conditioning pipes (not shown).

[0019] Pipe fitting 11 has a joint body 21, a nut member 22, a plurality of, specifically two, retaining members 23, a base member 24, a spacer 25, a seal member 26, an inner body 27, and an incore 28. Joint body 21, nut member 22, a plurality of retaining members 23, base member 24, spacer 25, seal member 26, and inner body 27 form an outer constituent body 30, and pipe fitting 11 is made up of this outer constituent body 30 and an incore 28 that is separate from it.

[0020] The joint body 21, nut member 22, inner body 27, and incore 28 are formed in a cylindrical shape, while the plurality of retaining members 23, base member 24, spacer 25, and seal member 26 are formed in an annular shape. The respective central axes of the joint body 21, nut member 22, plurality of retaining members 23, base member 24, spacer 25, seal member 26, inner body 27, and incore 28 are arranged coaxially with a common axis. Hereinafter, this common axis will be referred to as axis O. The direction along axis O will be referred to as the axial direction. The direction perpendicular to axis O will be referred to as the radial direction, and the direction circumferential around axis O will be referred to as the circumferential direction.

[0021] Here, the pipe fitting 11 includes a fitting body 21, a nut member 22, a plurality of retaining members 23, a base member 24, a spacer 25, a seal member 26, an inner body 27, and an incore 28, which constitute one fitting portion 31. Although not shown, the pipe fitting 11 also includes a second fitting portion having a similar configuration to the first fitting portion 31, which is axially mirror-symmetrical to the first fitting portion 31. The fitting body 21 has a mirror-symmetrical shape in the axial direction, and constitutes the first fitting portion 31 and the second fitting portion (not shown). The first fitting portion 31 is connected to one pipe P, and the second fitting portion (not shown) is connected to the second pipe (not shown). As a result, the pipe fitting 11 communicates a radially inner flow path of the first pipe P with a radially inner flow path of the second pipe (not shown). Here, the description will be given taking one joint portion 31 and one pipe P shown in FIG. 1 as an example.

[0022] At least the tip of the pipe P, which is connected to the pipe fitting 11, is cylindrical. The pipe P is made of, for example, resin, and specifically, a polyolefin water pipe. The pipe P is inserted into the fitting portion 31 from one axial side. In the following description, the front side of the fitting portion 31 in the axial insertion direction when the pipe P is inserted will be referred to as the front side in the pipe insertion direction, and the opposite side, i.e., the rear side in the axial insertion direction when the pipe P is inserted will be referred to as the rear side in the pipe insertion direction.

[0023] The joint body 21 is formed in a hollow cylindrical shape extending in the axial direction, with both axial ends open. The joint body 21 is formed so that its inner diameter increases from the axial center of the joint body 21 toward the front side in the pipe insertion direction. The inner circumferential surface of the joint body 21 has a multi-step shape. The joint body 21 has a cylindrical base portion 41 located in the axial center, i.e., the rear side in the pipe insertion direction, and a cylindrical housing portion 42 located on the front side in the pipe insertion direction, which constitutes one of the joint portions 31. The base portion 41 of the joint body 21 has a shape that is mirror-symmetrical in the axial direction, and has an housing portion (not shown) on the opposite side of the housing portion 42 of the base portion 41 that is mirror-symmetrical to the housing portion 42. This housing portion (not shown) constitutes the other joint portion.

[0024] The pipe P is inserted into the radially inner side of the accommodating portion 42 from one axial side, i.e., the front side in the pipe insertion direction. A male thread 45 is formed on the outer periphery of the accommodating portion 42 on the radially outer side. The radially inner side of the accommodating portion 42 forms an accommodating recess 48 that is recessed from the front side in the pipe insertion direction to the rear side in the pipe insertion direction along the axial direction. The accommodating recess 48 has, in order from the front side in the pipe insertion direction to the rear side in the pipe insertion direction, a first inner circumferential surface 51, a first step surface 52, a second inner circumferential surface 53, a second step surface 54, a third inner circumferential surface 55, and a third step surface 56.

[0025] The base portion 41 has, on its radially inner side, a fourth inner circumferential surface 57, a fourth step surface 58, and a fifth inner circumferential surface 59 in this order from the axial housing portion 42 side.

[0026] The first inner circumferential surface 51, the second inner circumferential surface 53, the third inner circumferential surface 55, the fourth inner circumferential surface 57, and the fifth inner circumferential surface 59 all face radially inward. The first step surface 52, the second step surface 54, the third step surface 56, and the fourth step surface 58 all face toward the front in the pipe insertion direction.

[0027] The first inner peripheral surface 51 has a cylindrical surface shape with the axis O as its center. The first step surface 52 has a flat surface extending radially inward so as to widen perpendicularly to the axis O from the rear side of the first inner circumferential surface 51 in the pipe insertion direction. The second inner peripheral surface 53 extends from the radially inner side of the first step surface 52 to the opposite side of the first inner peripheral surface 51 in the axial direction, and has a cylindrical surface shape with the axis O as its center. The first step surface 52 forms a step connecting the first inner circumferential surface 51 and the second inner circumferential surface 53 . The second step surface 54 has a flat surface extending radially inward so as to widen perpendicularly to the axis O from the side of the second inner peripheral surface 53 opposite to the first inner peripheral surface 51 in the axial direction. The third inner peripheral surface 55 extends from the radially inner side of the second step surface 54 to the opposite side of the second inner peripheral surface 53 in the axial direction, and has a cylindrical surface shape with the axis O as its center. The second step surface 54 forms a step connecting the second inner circumferential surface 53 and the third inner circumferential surface 55 . The third step surface 56 has a flat surface extending radially inward so as to widen perpendicularly to the axis O from the side of the third inner circumferential surface 55 opposite to the second inner circumferential surface 53 in the axial direction.

[0028] The fourth inner peripheral surface 57 extends from the radially inner side of the third step surface 56 to the opposite side of the third inner peripheral surface 55 in the axial direction, and has a cylindrical surface shape with the axis O as its center. The third step surface 56 forms a step connecting the third inner circumferential surface 55 and the fourth inner circumferential surface 57 . The fourth step surface 58 has a flat surface extending radially inward so as to widen perpendicularly to the axis O from the side of the fourth inner circumferential surface 57 opposite to the third inner circumferential surface 55 in the axial direction. The fifth inner peripheral surface 59 extends from the radially inner side of the fourth step surface 58 to the axially opposite side of the fourth inner peripheral surface 57, and has a cylindrical surface shape with the axis O as its center. The fourth step surface 58 forms a step connecting the fourth inner circumferential surface 57 and the fifth inner circumferential surface 59 .

[0029] The second inner circumferential surface 53 has a smaller diameter than the first inner circumferential surface 51, the third inner circumferential surface 55 has a smaller diameter than the second inner circumferential surface 53, the fourth inner circumferential surface 57 has a smaller diameter than the third inner circumferential surface 55, and the fifth inner circumferential surface 59 has a smaller diameter than the fourth inner circumferential surface 57. The fifth inner circumferential surface 59 is located in the central portion of the joint body 21 in the axial direction, and is a portion common to one joint portion 31 and the other joint portion (not shown).

[0030] The fourth inner circumferential surface 57 and the fourth step surface 58 form a recess 61. The recess 61 is located on the inner circumferential edge of the third step surface 56. The recess 61 is recessed axially from the third step surface 56 toward the rear in the pipe insertion direction. The recess 61 is provided around the entire circumferential direction of the fitting body 21. The recess 61 is annular. The recess 61 includes the fourth inner circumferential surface 57 and the fourth step surface 58, which are L-shaped in cross section, and a space extending in the axial direction on an axis corresponding to the fourth inner circumferential surface 57 and the fourth step surface 58. Note that the recess 61 may be omitted.

[0031] The joint body 21 is formed, for example, by injection molding of a synthetic resin material, or by cutting, casting, or forging of a metal material.

[0032] The nut member 22 has a cylindrical portion 72 , a stepped portion 73 , and a socket portion 74 . The cylindrical portion 72 is cylindrical and has an axis O as its center, and has an internal thread 71 formed on its inner periphery to be threaded onto the external thread 45 of the joint body 21 . The stepped portion 73 extends radially inward from the front side of the cylindrical portion 72 in the pipe insertion direction. The socket portion 74 is cylindrical and centered on the axis O, and extends from the radially inner side of the stepped portion 73 toward the opposite side of the cylindrical portion 72 in the axial direction, that is, toward the front side in the pipe insertion direction.

[0033] The nut member 22 is threaded onto the male thread 45 of the fitting body 21 at the female thread 71 of the tubular portion 72, with the stepped portion 73 abutting against the front end of the accommodation portion 42 in the pipe insertion direction. The inner diameter of the receiving portion 74 is slightly larger than the outer diameter of the pipe P. The nut member 22 is formed, for example, by injection molding of a synthetic resin material, or by cutting, casting, or forging of a metal material.

[0034] The radial inside of the receiving portion 74, on the side opposite the axial cylindrical portion 72, i.e., on the front side in the pipe insertion direction, forms a tapered surface 77 that increases in diameter toward the side opposite the cylindrical portion 72, and the portion on the axial cylindrical portion 72 side forms a cylindrical surface 78. Therefore, the inner circumferential surface of the nut member 22 is formed so that the diameter decreases toward the front side in the pipe insertion direction from the front side in the pipe insertion direction toward the rear side in the pipe insertion direction. This makes it easier to insert the inner core 28 into the nut member 22 and the pipe P into the nut member 22 when connecting pipes.

[0035] The multiple retaining members 23 have the same shape and include a perforated, circular, flat base plate 81 and a tapered locking plate 82 that extends axially while reducing in diameter from the inner periphery of the base plate 81. Each of the multiple retaining members 23 is fitted into the first inner circumferential surface 51 of the accommodating recess 48 with the locking plate 82 extending from the base plate 81 toward the rear in the pipe insertion direction. The inner diameter of the locking plate 82 of each retaining member 23 before the pipe P is inserted is smaller than the outer diameter of the pipe P. The retaining member 23 is a press-molded product made of metal, but may also be formed by injection molding of a synthetic resin material, or by cutting, casting, or forging of a metal material. The retaining member 23 is disposed within the accommodating recess 48. When the pipe P is inserted into the pipe fitting 11, the radially inner end of the locking plate 82 contacts and bites into the outer circumferential surface of the pipe P, preventing the pipe P from slipping out.

[0036] The base member 24 is annular and fits into the first inner circumferential surface 51 of the accommodating recess 48. The inner diameter of the base member 24 is larger than the inner diameter of the base plate portion 81 of the retaining member 23. The base member 24 is formed, for example, by injection molding of a synthetic resin material, or by cutting, casting, or forging of a metal material.

[0037] Spacer 25 is annular, fits over first inner circumferential surface 51 and second inner circumferential surface 53 of installation recess 48, and abuts against first step surface 52. The inner diameter of the portion of spacer 25 that fits into first inner circumferential surface 51 in the axial direction is larger than the inner diameter of base plate portion 81 of retaining member 23, and the inner diameter of the portion that fits into second inner circumferential surface 53 in the axial direction is slightly larger than the outer diameter of pipe P. Spacer 25 is formed, for example, by injection molding of a synthetic resin material, or by cutting, casting, or forging of a metal material.

[0038] One of the retaining members 23, with the locking plate 82 located at the rear side in the pipe insertion direction, abuts at its base plate 81 against the front side of the spacer 25 in the pipe insertion direction when the spacer 25 is fitted into the first inner circumferential surface 51 and the second inner circumferential surface 53 of the installation recess 48 and abuts against the first step surface 52. The base member 24 abuts against the front side of the base plate 81 in the pipe insertion direction, and the other retaining member 23, with the locking plate 82 located at the rear side in the pipe insertion direction, abuts at its base plate 81 against the front side of the base member 24 in the pipe insertion direction. The front side of the retaining member 23 in the pipe insertion direction is covered by the step portion 73 of the nut member 22. Two retaining members 23 are provided in the joint part 31, spaced apart in the axial direction. The retaining members 23 prevent the pipe P placed in the joint body 21 from coming off.

[0039] An annular seal member 26 is fitted into the second inner circumferential surface 53 of the accommodating recess 48, further back in the pipe insertion direction than the spacer 25. The seal member 26 is a rubber O-ring. The outer diameter of the seal member 26 before being placed within the second inner circumferential surface 53 is larger than the inner diameter of the second inner circumferential surface 53. The inner diameter of the seal member 26 before the pipe P is inserted is smaller than the outer diameter of the pipe P. The seal member 26 is provided in the accommodating recess 48, and when the pipe P is inserted into the coupling portion 31 of the pipe coupling 11, it comes into contact with the outer circumferential surface of the pipe P to seal between the pipe P and the coupling body 21.

[0040] An inner body 27 is provided within the second inner circumferential surface 53 and the third inner circumferential surface 55 of the installation recess 48, further rearward in the pipe insertion direction than the seal member 26. Therefore, the inner body 27 is provided further rearward in the installation recess 48 than the seal member 26 and the plurality of retaining members 23 in the pipe P insertion direction. The inner body 27 has an annular fitting portion 91 that fits into the second inner circumferential surface 53 and abuts against the second step surface 54, and an engagement piece 92 that extends rearward in the pipe insertion direction from the inner circumferential portion of the fitting portion 91. The inner diameter of the fitting portion 91 is larger than the outer diameter of the pipe P. The engagement piece 92 has an extension portion 93 that extends rearward in the pipe insertion direction from the inner circumferential portion of the fitting portion 91, and an inner protrusion 94 that protrudes radially inward from the extending tip of the extension portion 93. The inner protrusion 94 has an arc shape centered on the axis O. The engagement piece 92 extends inside the third inner circumferential surface 55 of the installation recess 48 up to just before the third step surface 56, and an axial gap 95 is formed between the inner protrusion 94 and the third step surface 56. The engagement piece 92 is elastically deformable, and the inner body 27 is provided with a plurality of engagement piece portions 92 of the same shape spaced apart in the circumferential direction. The inner body 27 is an injection-molded product made of a synthetic resin material, but may also be formed by cutting, casting, or forging a metal material.

[0041] The fitting body 21 and the nut member 22 form an inner core accommodating portion 101. The inner core accommodating portion 101 is a space that accommodates the inner core 28. The inner core accommodating portion 101 is a space that is formed by the fitting body 21 and the nut member 22 and is located on the front side of the fifth inner circumferential surface 59 in the pipe insertion direction. A plurality of anti-slip members 23, a base member 24, a spacer 25, and a seal member 26 are arranged approximately in the axial center of the inner core accommodating portion 101. The multiple anti-slip members 23 and the seal member 26 surround the pipe P so as to be in close contact with the pipe P when the pipe P is inserted into the pipe fitting 11. The base member 24 and the spacer 25 surround the pipe P when the pipe P is inserted into the pipe fitting 11. The first inner circumferential surface 51 , the first step surface 52 , the second inner circumferential surface 53 , the second step surface 54 , the third inner circumferential surface 55 , the third step surface 56 and the fourth inner circumferential surface 57 are formed in the inner core accommodating portion 101 .

[0042] The inner core 28 is formed in a hollow cylindrical shape extending in the axial direction, and both axial ends are open. The inner core 28 is an injection-molded product of a synthetic resin material, but may also be formed by cutting, casting, or forging a metal material. The inner core 28 has a cylindrical inner support portion 111 and an outer arrangement portion 112 that is arranged axially outward of the inner support portion 111. The entire inner core 28 is formed seamlessly as a single unit.

[0043] The inner support portion 111 is fitted into the tip portion of the pipe P in the insertion direction into the pipe fitting 11 and supports the tip portion of the pipe P from the radially inside. Therefore, the inner support portion 111 suppresses radial deformation of the tip portion of the pipe P.

[0044] The outer portion 112 is arranged axially outward of the tip face of the pipe P in the insertion direction into the pipe joint 11, that is, the tip face on the far side in the pipe insertion direction, and abuts against this tip face.

[0045] The outer diameter of the inner support portion 111 is smaller than the inner diameter of the in-core accommodating portion 101. The inner support portion 111 can be accommodated in the in-core accommodating portion 101. The inner support portion 111 has a first end portion 115 and a second end portion 116. The first end portion 115 is the end portion of the inner support portion 111 opposite the outer disposed portion 112 in the axial direction. The second end portion 116 is the end portion of the inner support portion 111 on the outer disposed portion 112 side in the axial direction. The inner support portion 111 of the in-core 28 is inserted axially from the first end portion 115 side into the tip portion of the pipe P in the insertion direction into the pipe fitting 11. With the inner support portion 111 positioned inside the pipe P, the pipe P is in close contact with the inner support portion 111 and is surrounded by the pipe P.

[0046] 1 , the incore 28 is arranged in the incore accommodating portion 101 so that the first end 115 is located on the front side in the pipe insertion direction in the axial direction of the fitting body 21. On the other hand, although not shown, when the pipe fitting 11 is stored, the incore 28 is inserted into the incore accommodating portion 101 so that the first end 115 is located on the rear side in the pipe insertion direction in the axial direction of the fitting body 21. The outer diameter of the first end 115 is larger than the inner diameter of the fifth inner circumferential surface 59 and smaller than the inner diameter of the recess 61. As a result, the first end 115 can be arranged in the recess 61 during storage as described above.

[0047] The outer disposed portion 112 is provided on one axial end side of the inner support portion 111 and is formed so as to protrude radially outward beyond the inner support portion 111 over the entire circumferential circumference. The inner circumferential surface of the outer disposed portion 112 is continuous with the inner circumferential surface of the inner support portion 111. The outer disposed portion 112 has, in this order from the axial opposite side to the inner support portion 111, a first large diameter portion 121 (large diameter portion), a small diameter portion 122, and a second large diameter portion 123. Note that the second large diameter portion 123 does not necessarily have to be provided.

[0048] The first large diameter portion 121 is annular and formed around the entire circumferential circumference of the in-core 28. The first large diameter portion 121 is located at the end opposite the inner support portion 111 in the axial direction, and its tip surface facing the opposite side from the inner support portion 111 is flat and extends perpendicular to the axis O. The tip surface of the first large diameter portion 121 is also located at the end of the in-core 28 in the axial direction. The first large diameter portion 121 has an outer peripheral surface on the radially outer side that tapers from the outer edge of the tip surface toward the inner support portion 111 in the axial direction, increasing in diameter as it approaches the inner support portion 111. The first large diameter portion 121 has a back surface located at the end on the inner support portion 111 side in the axial direction, and facing the inner support portion 111 side, which is provided at the end on the inner support portion 111 side in the axial direction, and has a flat surface that extends perpendicular to the axis O.

[0049] The first large diameter portion 121 has an outer diameter D1 that is larger than the inner diameter D2 (diameter of the inscribed circle) of the multiple inward protruding portions 94 of the inner body 27. The axial length of the first large diameter portion 121 is shorter than the axial length of a gap 95 between the inward protruding portions 94 of the engaging piece portions 92 of the inner body 27 and the third step surface 56 of the joint main body 21, and is positionable in the gap 95 on the farther side in the pipe insertion direction than the inward protruding portions 94 of the engaging piece portions 92.

[0050] The small diameter portion 122 is formed around the entire circumferential circumference of the in-core 28, and has a cylindrical outer peripheral surface. The small diameter portion 122 has an outer diameter D3 that is smaller than the outer diameter D1 of the first large diameter portion 121 and slightly smaller than the inner diameter D2 of the inward protrusion 94 of the engagement piece 92 of the inner body 27. The small diameter portion 122 has an outer diameter D3 that is larger than the inner diameter of the pipe P and smaller than the outer diameter of the pipe P. The axial length of the small diameter portion 122 is longer than the axial length of the inward protrusion 94 of the engagement piece 92, and as shown in FIG. 1 , it is possible to align the axial position with the inward protrusion 94 of the inner body 27. The first large diameter portion 121 protrudes radially outward from the small diameter portion 122 around the entire circumference.

[0051] The second large diameter portion 123 is formed around the entire circumferential circumference of the in-core 28. As described above, the second large diameter portion 123 may not be provided. In the illustrated example, the second large diameter portion 123 has a tapered outer peripheral surface that expands radially outward from the axially inner support portion 111-side edge of the outer peripheral surface of the small diameter portion 122 toward the inner support portion 111. The second large diameter portion 123 has a back surface at the axially inner support portion 111-side end of the outer peripheral surface facing the inner support portion 111 that expands radially inward from the axially inner support portion 111-side edge of the outer peripheral surface, forming a flat surface that expands perpendicular to the axis O. The back surface of the second large diameter portion 123 is provided at the axially inner support portion 111-side end of the outer arrangement portion 112. When the pipe P is connected to the in-core 28 as shown in FIG. 1, the back surface of the second large diameter portion 123 abuts against the tip surface of the pipe P at the rear end in the pipe insertion direction. The second large diameter portion 123 protrudes radially outward beyond the small diameter portion 122 over the entire circumference.

[0052] Although not shown in the drawings, when the pipe fitting 11 is stored, the outer placement portion 112 may be inserted into the inner core accommodating portion 101 so as to be positioned on the front side in the pipe insertion direction in the axial direction of the fitting body 21. In this case, it is preferable that the outer placement portion 112 does not protrude outward in the axial direction from the inner core accommodating portion 101 (nut member 22).

[0053] 1 , even if the outer placement portion 112 is positioned at the rear in the pipe insertion direction, the outer placement portion 112 is not positioned within the recess 61. At this time, the first large diameter portion 121 of the outer placement portion 112 is positioned in the gap 95 between the inward protrusion 94 of the engagement piece 92 of the inner body 27 and the third step surface 56 of the fitting main body 21. In this state, when the first large diameter portion 121 abuts against the third step surface 56 at the tip surface on the opposite side of the inner support portion 111 in the axial direction, further movement of the outer placement portion 112 toward the rear in the pipe insertion direction is restricted. Also, in this state, when the first large diameter portion 121 abuts against the inward protrusion 94 of the engagement piece 92 at the back surface on the inner support portion 111 side, further movement of the outer placement portion 112 toward the front in the pipe insertion direction is restricted, so that the outer placement portion 112 does not easily come out of the outer component 30.

[0054] In addition, the outer peripheral surface of the first large diameter portion 121 on the radially outer side is formed so that when the pipe P is connected to the pipe fitting 11, the diameter decreases as it moves toward the rear in the pipe insertion direction. Therefore, when connecting the pipes, the inner core 28 can be easily inserted from the first large diameter portion 121 into the outer component 30 including the nut member 22, the anti-slip member 23, the spacer 25, the seal member 26, and the inner body 27.

[0055] The synthetic resin material applicable to the joint body 21, nut member 22, base member 24, spacer 25, inner body 27, and incore 28 can be selected arbitrarily based on the quality design appropriate for the application, such as cross-linked polyethylene, polybutene, polyvinyl chloride (PVC), polysulfone resin (PSU), polycarbonate resin (PC), polyamide resin (PA), polyacetal resin (POM), polyphenylsulfone resin (PPSU), polyphenylene sulfide resin (PPS), glass fiber reinforced PPS, polyvinylidene fluoride (PVDF), etc. Other processing methods such as cutting and welding may also be used.

[0056] The metal materials applicable to the joint body 21, the nut member 22, the retaining member 23, the base member 24, the spacer 25, the inner body 27, and the incore 28 can be arbitrarily selected based on quality design according to the application, including stainless steel, low-alloy steel, carbon steel, low-temperature carbon steel, low-temperature alloy steel, brass, gunmetal, aluminum alloy, magnesium alloy, etc.

[0057] The material of the sealing member 26 may be rubber material such as ethylene propylene diene rubber (EPDM), fluororubber (FKM), vinyl methyl silicone rubber (VMQ), acrylonitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), or chloroprene rubber (CR).

[0058] (Pipe connection method) Next, a piping connection method for connecting the pipe P to the pipe joint 11 will be described. During storage of the pipe fitting 11 before the pipe P is connected, the incore 28 is accommodated in the incore accommodating portion 101 of the outer constituent body 30. Although not shown in the figures, specifically, the outer arrangement portion 112 of the incore 28 is positioned on the front side in the pipe insertion direction relative to the inner support portion 111 and is fitted into the socket portion 74 of the nut member 22, and the first end portion 115 of the inner support portion 111 is accommodated in the recess 61 of the fitting body 21. The installer removes the incore 28 in this state by pulling it out toward the front side in the pipe insertion direction from the incore accommodating portion 101 of the outer constituent body 30, and then performs an incore attachment step in which the inner support portion 111 is inserted into the tip of the pipe P on the connection side to the pipe fitting 11, and attaches the incore 28 to the pipe P.

[0059] By performing this incore attachment process, the pipe P with the incore 28 attached is inserted into the outer component 30 from the front side in the pipe insertion direction, with the outer disposed portion 112 of the incore 28 leading the way, into the socket portion 74 of the nut member 22, and into the installation recess 48 of the fitting body 21, in that order. Then, the outer disposed portion 112 of the incore 28 passes through the socket portion 74 of the nut member 22, and then through the retaining member 23, the base member 24, the retaining member 23, the spacer 25, and the sealing member 26. This brings the multiple retaining members 23 and the sealing member 26 into contact with the outer peripheral surface of the pipe P. In other words, this process is an insertion process in which the sealing member 26 and multiple retaining members 23 come into contact with the outer peripheral surface of the pipe P.

[0060] After this insertion step, as the pipe P with the attached incore 28 continues to be inserted deeper into the outer constituent body 30 in the pipe insertion direction, the first large diameter portion 121 of the outer arrangement portion 112 of the incore 28 presses the inner protruding portion 94 of the inner body 27 of the outer constituent body 30 radially outward with its tapered outer peripheral surface, elastically deforming the engaging piece portion 92 radially outward. In other words, this step becomes a pressing step in which insertion of the pipe P is further advanced from the insertion step, and the first large diameter portion 121 of the incore 28 presses the inner protruding portion 94 of the inner body 27 radially outward, elastically deforming the engaging piece portion 92 radially outward.

[0061] After this pressing step, as the pipe P with the attached incore 28 continues to be inserted further into the outer constituent body 30 in the pipe insertion direction, the first large diameter portion 121 of the incore 28 is positioned further back in the insertion direction than the inner protruding portion 94 of the inner body 27, the inner protruding portion 94 is positioned at the position of the small diameter portion 122 of the incore 28, and the engagement piece 92 is released from being pressed radially outward. Then, the engagement piece 92 returns from elastic deformation and collides with the small diameter portion 122. In other words, this step is an engagement step in which the pipe P is inserted further from the pressing step, the first large diameter portion 121 of the incore 28 is positioned further back in the insertion direction than the inner protruding portion 94, and the inner protruding portion 94 is positioned at the position of the small diameter portion 122 of the incore 28, and the engagement piece 92 returns from elastic deformation and the inner protruding portion 94 abuts against the small diameter portion 122. At the end of this engagement process, the engagement piece 92 returns from its elastic deformation and causes the inner protrusion 94 to collide with the small diameter portion 122 of the in-core 28, generating an attachment sound (click sound).

[0062] After the engaging step, even if an attempt is made to further insert the pipe P, to which the inner core 28 is attached, into the outer constituent body 30 toward the rear in the pipe insertion direction, the first large diameter portion 121 abuts against the third step surface 56 of the fitting body 21 at the tip surface on the side opposite the inner support portion 111 in the axial direction, restricting further insertion. Furthermore, even if an attempt is made to move the inner core 28 in the removal direction relative to the outer constituent body 30, the first large diameter portion 121 abuts against the inner protruding portion 94 of the inner body 27 at the back surface on the inner support portion 111 side in the axial direction, restricting movement.

[0063] The pipe fitting 11 of the present embodiment described above is an external watertight fitting in which the seal member 26 provided in the installation recess 48 of the fitting body 21 contacts the outer circumferential surface of the pipe P to seal between the pipe P and the fitting body 21. Furthermore, the incore 28, which supports the pipe P from the inside, is separate from the fitting body 21 and can be thinned, making it suitable as a high-flow pipe fitting. Specifically, forming the fitting body 21 and the incore 28 separately eliminates molding constraints that are present in an integrated incore. This improves molding stability and flexibility, making it easy to thin the incore 28, for example. Furthermore, thinning the incore 28 increases the flow path diameter, thereby improving flow rate. Furthermore, thinning the incore 28 ensures sufficient clearance for removing the core pin from the inner circumferential surface of the incore 28. This ensures a sufficient draft angle, facilitating injection molding. Since the incore 28 is made of resin, the incore 28 can be easily inserted into the outer structural body 30 due to the deformability of the resin.

[0064] Furthermore, an elastically deformable engaging piece 92 is provided on inner body 27, which is provided further back in the insertion direction of pipe P than sealing member 26 and retaining member 23 within accommodating recess 48, and which has an extending portion 93 extending toward the back in the insertion direction and an inner protruding portion 94 protruding radially inward from the extending tip of extending portion 93. An outer disposed portion 112, which is disposed axially outward of the tip of pipe P of incore 28, is provided with a first large diameter portion 121 whose outer diameter is larger than the inner diameter of inner protruding portion 94 and which can be positioned further back in the insertion direction than the inner protruding portion. Thus, the pipe P with the incore 28 attached is inserted into the accommodation recess 48 of the fitting body 21 from one side, bringing the seal member 26 and the retaining member 23 into contact with the outer circumferential surface of the pipe P. As the pipe P is further inserted, the first large diameter portion 121 of the incore 28 presses the inner protrusion 94 of the inner body 27 radially outward, elastically deforming the engagement piece 92 radially outward. As the pipe P is further inserted and the first large diameter portion 121 of the incore 28 is positioned further back in the insertion direction than the inner protrusion 94, the inner protrusion 94 of the engagement piece 92 is positioned at the position of the small diameter portion 122 of the incore 28, which is closer to the inner support portion 111 than the first large diameter portion 121, and the engagement piece 92 returns from elastic deformation. At this time, the inner protrusion 94 collides with the small diameter portion 122 of the incore 28, generating an attachment sound (click sound). This attachment sound lets the installer know that the incore 28 has not been forgotten to be attached. This makes it possible to prevent forgetting to attach the inner core 28. Furthermore, since the inner core 28 is used to prevent the generation of attachment noise, it is only necessary to add the inner body 27, and it is possible to prevent an increase in costs.

[0065] Furthermore, the pipe fitting 11 has a plurality of engaging pieces 92 spaced apart in the circumferential direction on the inner body 27, which can increase the sound produced by the fitting. This further reduces the likelihood of forgetting to fit the inner core 28.

[0066] Furthermore, because the pipe fitting 11 is formed such that the fitting body 21 and the incore 28 are molded separately, at the time of shipment, the incore 28 is in a state in which, for example, the first end 115 of the inner support portion 111 is disposed in the recess 61 of the fitting body 21 and the outer disposed portion 112 is disposed in the socket portion 74 of the nut member 22. If the assembly process of assembling the incore 28 to the fitting body 21 and the nut member 22 is performed using an automatic assembly machine, the automatic assembly machine will, for example, grasp the first large diameter portion 121 of the incore 28 from the radially outer side and insert the incore 28 into the incore accommodating portion 101 with the first end 115 of the inner support portion 111 leading, thereby disposing the first end 115 of the inner support portion 111 in the recess 61 of the fitting body 21 and disposing the second large diameter portion 123 of the outer disposed portion 112 in the socket portion 74 of the nut member 22. At this time, because the outer placement portion 112 of the incore 28 has an uneven shape having the first large diameter portion 121 and the small diameter portion 122, when the outer placement portion 112 is gripped to mount the incore 28 into the incore accommodating portion 101, it is easy to position the assembly jig that grips the incore 28, and the incore 28 can be assembled into the incore accommodating portion 101 without axial wobble. This improves the ease of assembly of the pipe fitting 11.

[0067] Furthermore, according to the piping connection structure 12 in which the pipe P is connected to the pipe fitting 11, as described above, the pipe fitting 11 is suitable as a high-flow pipe fitting, and therefore suitable for high-flow piping. Furthermore, when the pipe P with the incore 28 attached is inserted from one side into the installation recess 48 of the fitting body 21, the engaging piece portion 92 of the inner body 27 collides with the small diameter portion 122 of the incore 28, generating an installation sound, allowing the installer to recognize that the incore 28 has not been forgotten to be attached. This makes it possible to prevent the incore 28 from being forgotten to be attached. Furthermore, because the incore 28 is used to generate the installation sound, only an additional inner body 27 is required, thereby suppressing cost increases.

[0068] Furthermore, according to the piping connection method for connecting a pipe P to a pipe fitting 11, the inner support portion 111 is inserted into the tip portion of the pipe P to attach the incore 28, the pipe P is inserted into the accommodating recess 48 of the fitting body 21 from one side, and the sealing member 26 and the retaining member 23 are brought into contact with the outer peripheral surface of the pipe P, the insertion of the pipe P is further advanced so that the first large diameter portion 121 of the incore 28 presses the inner protruding portion 94 of the inner body 27 radially outward, causing the engaging piece portion 92 to elastically deform radially outward, the insertion of the pipe P is further advanced so that the first large diameter portion 121 of the incore 28 is positioned further back in the pipe insertion direction than the inner protruding portion 94, and the inner protruding portion 94 is positioned at the position of the small diameter portion 122 on the inner support portion 111 side of the first large diameter portion 121 of the incore 28, thereby returning the engaging piece portion 92 from elastic deformation and causing the inner protruding portion 94 to collide with the small diameter portion 122 of the incore 28.

[0069] This piping connection method makes the pipe fitting 11 suitable as a high-flow pipe fitting, and therefore suitable for high-flow piping. Furthermore, by inserting the pipe P with the incore 28 attached into the installation recess 48 of the fitting body 21 from one side, the engaging piece portion 92 of the inner body 27 collides with the small diameter portion 122 of the incore 28, generating an attachment sound, allowing the installer to recognize that the incore 28 has not been forgotten to be attached. This makes it possible to prevent the incore 28 from being forgotten to be attached. Furthermore, because the incore 28 is used to generate the attachment sound, only an additional inner body 27 is required, and increases in costs can be suppressed.

[0070] Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configurations are not limited to these embodiments, and the present invention also includes modifications, combinations, deletions, etc. of the configurations within the scope of the gist of the present invention. Furthermore, it goes without saying that the configurations shown in each embodiment can be used in appropriate combinations. [Explanation of symbols]

[0071] 11...pipe fitting, 12...piping connection structure, 21...fitting body, 23...anti-pullout member, 26...sealing member, 27...inner body, 28...incore, 48...accommodating recess, 92...engaging piece portion, 93...extension portion, 94...inner protrusion portion, 111...inner support portion, 112...outer arrangement portion, 121...first large diameter portion (large diameter portion), 122...small diameter portion, P...pipe.

Claims

1. a joint body having an accommodating recess into which a pipe is inserted from one side; a seal member provided in the accommodating recess and in contact with an outer peripheral surface of the pipe to seal between the pipe and the joint body; a retaining member provided in the receiving recess and contacting an outer circumferential surface of the pipe to prevent the pipe from coming out; an inner body provided in the accommodating recess on a deeper side than the sealing member and the retaining member in the insertion direction of the pipe; an in-core having an inner support portion that supports the pipe from the inside and an outer arrangement portion that is arranged axially outward from the tip of the pipe; Equipped with The inner body is provided with an elastically deformable engagement piece having an extension portion extending toward the rear side in the insertion direction and an inner protrusion portion protruding radially inward from an extension tip of the extension portion, A pipe fitting in which the outer positioned portion of the inner core is provided with a large diameter portion whose outer diameter is larger than the inner diameter of the inner protrusion and which can be positioned further back in the insertion direction than the inner protrusion.

2. 2. The pipe joint according to claim 1, wherein the inner body has a plurality of engaging pieces provided at intervals in the circumferential direction.

3. A piping connection structure in which the pipe is connected to the pipe joint according to claim 1 or 2.

4. A piping connection method for connecting the pipe to the pipe joint according to claim 1 or 2, comprising: a step of inserting the inner support part into the tip part of the pipe to attach the inner core; a step of inserting the pipe with the in-core attached into the accommodating recess of the joint body from one side to bring the sealing member and the retaining member into contact with an outer peripheral surface of the pipe; Further inserting the pipe, and pushing the inner protruding portion of the inner body radially outward with the large diameter portion of the inner core, thereby elastically deforming the engaging piece portion radially outward; further inserting the pipe to position the large diameter portion of the inner core further in the insertion direction than the inner protrusion, and position the inner protrusion closer to the inner support portion than the large diameter portion, thereby returning the engagement piece from elastic deformation and causing the inner protrusion to collide with the inner core; Methods for connecting piping, including:

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