Joint

Abstract

To provide a joint which can reduce a risk of the impairment of exterior appearance.SOLUTION: A piping adapter 1 comprises a joint main body 10 which is formed of a resin material, a female screw insert 20 embedded into the joint main body 10 and screwed with a male screw 122 of piping 121, a connection mechanism 30 which can connect a tip part of a water supply pipe 111, and a packing 40. In the joint main body 10, specifically, a flank body part 11 has a coating part 13 for coating a first end face 22 being an end face of the female screw insert 20 at a side facing the piping 121. The coating part 13 has a heavy-thickness part 14, and a thin-thickness part 15 arranged radially inside of the female insert 20 relative to the heavy-thickness part 14.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a joint for connecting, for example, water supply pipes, faucets, etc. [Background technology]

[0002] In joints such as piping adapters for connecting water supply pipes, faucets, etc., there are joints in which a metal female thread insert is embedded in a resin joint body (for example, Patent Document 1). In the joint of Patent Document 1, the female thread insert is embedded in a joint body formed from a resin material. A mating member such as a pipe or a faucet having a male thread formed therein can be screwed into the female thread insert. The joint body is formed with a resin covering portion that covers the radially outer portion of the end face of the female thread insert that faces the mating member. Therefore, even if the pipe is screwed into the female thread insert with a strong force, the pipe and the female thread insert do not come into direct contact with each other, and the covering portion is interposed between them to reduce the torque transmitted from the pipe to the female thread insert, and excessive stress can be prevented from being applied to the female thread insert and the resin material around it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6576731 Summary of the Invention [Problem to be solved by the invention]

[0004] However, burrs sometimes occurred on the inner peripheral edge of the coating. Because the burrs are thin, if burrs occur on a coating that is formed relatively thick, the burrs stand out due to the contrast between the thickness and the thinness, which can mar the appearance. An object of the present invention is to provide a joint that can reduce the risk of impairing the appearance. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, the joint of the invention of claim 1 comprises a joint body formed from a resin material, and a female thread insert embedded in the joint body and capable of screwing into a male thread of a mating member, wherein the joint body has a covering portion that covers an end face of the female thread insert on the side facing the mating member, and the covering portion has a thick-walled portion and a thin-walled portion provided radially inward of the female thread insert relative to the thick-walled portion.

[0006] The invention of claim 2 is the same as claim 1, in which the inner peripheral edge of the thin portion extends to the inner peripheral edge of the end face of the female thread insert.

[0007] The invention of claim 3 is based on claim 1 or 2, and the thickness of the thin portion is equal to or less than half the thickness of the thick portion. [Brief description of the drawings]

[0008] [Figure 1] Cross-sectional view showing the piping adapter. [Diagram 2] 5A to 5C are cross-sectional views for explaining a manufacturing method of the piping adapter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <One embodiment> DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described in which the present invention is embodied in a piping adapter used for routing water supply piping through the floorboards of a building.

[0010] FIG. 1 shows a piping adapter 1 as a joint to be installed in, for example, a floor panel 101. The upper right part of FIG. 1 shows an enlarged view of the part of the piping adapter 1 surrounded by a dashed line. The floor panel 101 is formed with a through hole 101a that communicates between an underfloor space (lower side of FIG. 1) and an above-floor space (upper side of FIG. 1) that becomes the room. The tip of a water supply pipe 111 made of resin such as cross-linked polyethylene is arranged on the underfloor space side of the through hole 101a, and a metal pipe 121 as a mating member is arranged on the above-floor space side of the through hole 101a. A male thread 122 is formed at the tip of the pipe 121.

[0011] The axis L represents the central axis of the piping adapter 1. Hereinafter, in the direction of the axis L of the piping adapter 1, the direction in which the piping adapter 1 faces the piping 121 (the left side in FIG. 1) may be referred to as a first direction Y1, and the direction in which the piping adapter 1 faces the water supply pipe 111 (the right side in FIG. 1) may be referred to as a second direction Y2.

[0012] The piping adapter 1 is inserted into the through hole 101a and connects the water supply pipe 111 and the piping 121 so that water from the water supply pipe 111 in the underfloor space is supplied to the piping 121 in the above-floor space via the piping adapter 1. A male thread 122 of the piping 121 is connected to the end of the piping adapter 1 on the first direction Y1 side, and a tip of the water supply pipe 111 is connected to the end of the piping adapter 1 on the second direction Y2 side.

[0013] The piping adapter 1 comprises a fitting body 10 formed from a resin material, a female thread insert 20 embedded in the end of the fitting body 10 on the first direction Y1 side and capable of screwing into a male thread 122 of a piping 121, a connection mechanism 30 provided at the end on the second direction Y2 side and capable of connecting the tip of a water supply pipe 111, and a gasket 40.

[0014] The joint body 10 is formed from a resin material such as polyphenylene sulfide (PPS) [engineering plastic]. The joint body 10 has a substantially cylindrical body portion 11 and a disk-shaped flange portion 12 extending radially outward from a first end portion (the end portion on the first direction Y1 side) of the body portion 11. The body portion 11 and the flange portion 12 are integrally formed. The flange portion 12 is provided with a plurality of screw holes 12a (three in this embodiment) and is configured so as to be fixed to a floor plate 101 using screws or the like (not shown).

[0015] The female thread insert 20 is generally cylindrical and has a female thread 21, a first end face 22 located on the first direction Y1 side, a second end face 23 located on the opposite side to the first end face 22, and an outer circumferential surface 24. The female thread 21 has a tapered shape that expands in diameter toward the first end side. The first end face 22 has a generally flat annular shape and is the end face of the female thread insert 20 on the side facing the pipe 121, which is the counterpart member.

[0016] A chamfer 22a consisting of a 45° C-chamfer is provided on a radially inner portion of the first end face 22. A chamfer 22b consisting of a R-chamfer is provided on a radially outer portion of the first end face 22.

[0017] A plurality of grooves 24a extending in the circumferential direction are formed on the outer peripheral surface 24 of the female thread insert 20, which restricts the misalignment of the female thread insert 20 in the axial L direction relative to the joint body 10. Furthermore, the outer peripheral surface 24 of the female thread insert 20 is knurled to form uneven portions (not shown) extending in the axial L direction, which restricts the rotation of the female thread insert 20 about the axis L relative to the joint body 10. The female thread insert 20 has an inner circumferential surface 25 adjacent to the first end surface 22 radially inward.

[0018] The connection mechanism 30 includes a lock ring 31 , a lock ring holder 32 , a split ring 33 , two O-rings 34 , an O-ring holder 35 , a spacer 36 , and a cap 37 .

[0019] The lock ring 31 bites into the outer circumferential surface of the water supply pipe 111 to prevent the water supply pipe 111 from coming off from the piping adapter 1 (specifically, the connection mechanism 30). The lock ring holder 32 restricts the movement of the lock ring 31 in the axial direction L to position the lock ring 31. The split ring 33 reduces its diameter when the water supply pipe 111 moves in the second direction Y2 to prevent the water supply pipe 111 from coming off. The O-ring 34 abuts against the outer circumferential surface of the water supply pipe 111 to ensure watertightness of the connection between the piping adapter 1 and the water supply pipe 111. The O-ring holder 35 restricts the O-ring 34 from coming off. The spacer 36 prevents the two O-rings 34 from coming into direct contact with each other. The end of the fitting body 10 is inserted into the open end of the cylindrical cap 37, so that the lock ring 31, the lock ring holder 32, the split ring 33, and the O-ring holder 35 are sandwiched between the fitting body 10.

[0020] The in-core 112 ensures the circularity of the tip of the water supply pipe 111, prevents the water supply pipe 111 from coming loose from the piping adapter 1, and makes the connection between the water supply pipe 111 and the piping adapter 1 more watertight.

[0021] The packing 40 is provided on the second direction Y2 side of the flange portion 12, and is arranged to be interposed between the flange portion 12 and the floor plate 101 when the flange portion 12 is fixed to the floor plate 101.

[0022] Next, the structure in which the first end face 22 of the female thread insert 20 is covered with resin in the joint body 10 will be described in detail.

[0023] The fitting body 10, specifically the body portion 11, has a covering portion 13 that covers a first end face 22, which is an end face of the female thread insert 20 on the side facing the pipe 121. The covering portion 13 has a thick portion 14 and a thin portion 15 that is provided radially inward of the female thread insert 20 relative to the thick portion 14. That is, the radial outer portion of the covering portion 13 is formed of the relatively thick thick portion 14, and the radial inner portion of the covering portion 13 is formed of the relatively thin thin portion 15.

[0024] In detail, the end face 14a of the thick-walled portion 14 on the first direction Y1 side has a flat annular shape, and is continuously connected to the end faces of the body portion 11 and the flange portion 12 on the first direction Y1 side and located on the same plane. That is, the end face 14a of the thick-walled portion 14 forms a part of the end face on the first direction Y1 side of the piping adaptor 1. On the other hand, the end face 15a of the thin-walled portion 15 on the first direction Y1 side has a flat annular shape, and is closer to the first end face 22 of the female thread insert 20 in the axial L direction than the end faces of the body portion 11 and the flange portion 12 on the first direction Y1 side. That is, in the axial L direction, the end face 15a of the thin-walled portion 15 is closer to the end face 22 of the female thread insert 20 than the end face 14a of the thick-walled portion 14.

[0025] The inner peripheral edge of the thin-walled portion 15 extends to the inner peripheral edge of the first end face 22 of the female thread insert 20. That is, the thin-walled portion 15 is provided from the inner peripheral edge of the thick-walled portion 14 to the inner peripheral edge of the first end face 22 of the female thread insert 20. As a result, the covering portion 13 covers the entire first end face 22 of the female thread insert 20. In detail, the thick-walled portion 14 and the thin-walled portion 15 each have an annular shape, and the boundary between the thick-walled portion 14 and the thin-walled portion 15 is circular. The thick-walled portion 14 covers the radially outer portion of the first end face 22 of the female thread insert 20 over the entire circumferential direction. The thin-walled portion 15 covers the radially inner portion of the first end face 22 over the entire circumferential direction.

[0026] The inner circumferential surface 15b of the thin-walled portion 15 and the inner circumferential surface 25 adjacent to the first end face 22 of the female thread insert 20 are continuous and are located on the same cylindrical surface with the axis L as the central axis. The thickness T2 of the thin portion 15 is equal to or less than half the thickness T1 of the thick portion 14. Preferably, the thickness T2 of the thin portion 15 is equal to or less than 1 / 3 the thickness T1 of the thick portion 14. For example, the thickness T1 of the thick portion 14 can be set to 1.7 mm, and the thickness T2 of the thin portion 15 can be set to 0.5 mm.

[0027] Next, a method for manufacturing the piping adapter 1 configured as above will be described. As shown in Fig. 2, the piping adaptor 1 can be manufactured by insert molding using a female thread insert 20, using a mold 50 having a core pin 60, a movable mold 70, and a slide 80. The upper side of Fig. 2 corresponds to the upper side in the actual manufacturing process.

[0028] In the insert molding, first, the female thread insert 20 is mounted on the core pin 60 from the first end face 22 side so that the core pin 60 passes through the female thread 21 of the female thread insert 20. At this time, the female thread insert 20 is held by the core pin 60 with the inner peripheral surface of the female thread insert 20 abutting against the outer peripheral surface of the core pin 60.

[0029] Next, the core pin 60, the movable die 70, and the slide 80 are appropriately fixed or moved, and the mold 50 is clamped as shown in Fig. 2. Molten resin is injected into the cavity C of the mold 50, and the resin is solidified around the female thread insert 20 and the core pin 60 to form the joint body 10. Then, the mold 50 is opened, and the female thread insert 20 and the joint body 10 are pulled out from the core pin 60.

[0030] Thereafter, the connection mechanism 30 and the packing 40 are attached to the joint body 10, and the piping adapter 1 is manufactured.

[0031] Next, the effects of the piping adapter 1 of this embodiment will be described. (1) As shown in Fig. 1, covering portion 13 has thin-walled portion 15 provided radially inward of thick-walled portion 14. Even if resin burrs occur in covering portion 13, the burrs will be adjacent to thin-walled portion 15. Because the burrs are adjacent to thin-walled portion 15 rather than thick-walled portion 14, they are less noticeable in terms of thickness contrast, and the risk of the appearance of the piping adapter 1 being marred can be reduced.

[0032] (2) The inner peripheral edge of the thin-walled portion 15 extends to the inner peripheral edge of the first end face 22 of the female thread insert 20. If burrs are generated on the first end face 22 of the female thread insert 20, the burrs are easily noticeable when the piping adapter 1 is visually observed from the first end face 22 side, but since the first end face 22 of the female thread insert 20 is not exposed radially inward of the thin-walled portion 15, no burrs are generated on the first end face 22. This further reduces the risk of impairing the appearance.

[0033] (3) The thickness T2 of the thin portion 15 is equal to or less than half, and preferably equal to or less than one-third, of the thickness T1 of the thick portion 14. In other words, the thickness T2 of the thin portion 15 is made sufficiently thinner than the thickness T1 of the thick portion 14. Therefore, even if a burr occurs adjacent to the thin portion 15, the burr becomes even less noticeable, and the risk of impairing the appearance can be further reduced.

[0034] (4) The inner circumferential surface 15b of the thin portion 15 and the inner circumferential surface 25 adjacent to the first end face 22 of the female thread insert 20 are continuous. Therefore, even if burrs are generated, they will be generated on the inner circumferential surface 25 of the female thread insert 20. However, it is relatively easy to design so that no gap is generated between the inner circumferential surface 25 of the female thread insert 20 and the outer circumferential surface of the core pin 60, making it possible to prevent burrs from being generated and further reducing the risk of impairing the appearance.

[0035] <Another example> The above embodiment can be modified, for example, as follows. The covering portion 13 may be configured to cover only a part of the first end face 22 of the female thread insert 20 instead of the entirety. For example, a part of the thin-walled portion 15 may be cut out to expose a part of the first end face 22. Alternatively, the thin-walled portion 15 may be formed as an annular shape extending from the thick-walled portion 14 to a midpoint between the inner peripheral edge of the thick-walled portion 14 and the inner peripheral edge of the first end face 22, to expose a radially inner portion of the first end face 22.

[0036] The boundary between the thick portion 14 and the thin portion 15 does not have to be circular. For example, the boundary between the thick portion 14 and the thin portion 15 may be polygonal.

[0037] The thick-walled portion 14 may be configured to cover a portion of the circumferential direction of the radially outer portion of the first end face 22 of the female thread insert 20. In other words, the thick-walled portion 14 may be configured to cover at least a portion of the circumferential direction of the radially outer portion of the first end face 22.

[0038] The thick-walled portion 14 does not have to form the end face on the first direction Y1 side of the piping adapter 1. For example, the thickness T1 of the thick-walled portion 14 may be slightly thinner, and only the end faces on the first direction Y1 side of the body portion 11 and the flange portion 12 may form the end faces on the first direction Y1 side of the piping adapter 1.

[0039] The end surface 15a of the thin portion 15 on the first direction Y1 side does not have to be flat, and may have an uneven shape. A transition portion may be provided between the thick portion 14 and the thin portion 15, in which the thickness gradually changes from thickness T1 to thickness T2 radially inward.

[0040] The thickness T2 of the thin portion 15 may be thinner than the thickness T1 of the thick portion 14, and may be thicker than half the thickness T1. The resin constituting the joint body 10 does not have to be polyphenylene sulfide. For example, polyamide (nylon) resin, polyacetal resin, polyester resin, polycarbonate resin, polysulfone resin, polyimide resin, etc. may be used.

[0041] The configuration of the connection mechanism 30 is not limited to the above. For example, it may be a structure in which the connection is screwed together with a screw, or a structure in which the connection is made by electrical fusion. The fitting is not limited to a piping adapter, but may be a different type of fitting such as an elbow with a seat. [Explanation of symbols]

[0042] 1...piping adapter, 10...joint body, 11...body portion, 12...flange portion, 13...covering portion, 14...thick portion, 14a...end face, 15...thin portion, 15a...end face, 15b...inner peripheral surface, 20...female thread insert, 21...female thread, 22...first end face, 22a, 22b...chamfer, 23...second end face, 24...outer peripheral surface, 24a...groove, 25...inner peripheral surface, 30...connection mechanism, 31...lock ring, 32...lock ring pressed E, 33...split ring, 34...O-ring, 35...O-ring retainer, 36...spacer, 37...cap, 40...packing, 50...mold, 60...core pin, 70...movable mold, 80...slide, 101...floor plate, 101a...through hole, 111...water supply pipe, 112...in-core, 121...piping, 122...male thread, C...cavity, L...shaft, T1...thickness, T2...thickness, Y1...first direction, Y2...second direction.

Claims

1. a joint body formed from a resin material; A female thread insert is embedded in the joint body and is capable of screwing into a male thread of a mating member; Equipped with The joint body has a covering portion that covers an end face of the female thread insert on a side facing the mating member, The covering portion is a joint having a thick portion and a thin portion provided radially inward of the female thread insert relative to the thick portion.

2. 2. The joint of claim 1, wherein an inner periphery of said thinned portion extends to an inner periphery of an end face of said female threaded insert.

3. 3. A joint according to claim 1 or 2, wherein the thickness of the thin-walled portion is equal to or less than half the thickness of the thick-walled portion.

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