JP7274098B2 - pipe joint - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pipe joint that uses a lock ring to prevent a pipe from coming off.

FIG. 22 shows a pipe joint 101 described in Patent Document 1. As shown in FIG. The pipe joint 101 includes a joint body 102, a retaining mechanism 103 for holding a resin pipe 151 in the joint body 102, and a synthetic resin cap 104 for attaching the retaining mechanism 103 to the joint body 102. I have. A seal ring 105 is arranged in the joint main body 102 to achieve watertightness with the resin pipe 151 .

The retaining mechanism 103 has a lock ring 106 made of metal. The retaining mechanism 103 includes a synthetic resin lock ring presser 107 for positioning (centering) the lock ring 106 . The cap 104, to which the lock ring 106 and the lock ring retainer 107 are assembled, is fitted onto the joint body 102 and fixed by snap engagement.

As shown in FIGS. 22 and 23, a positioning projection 107a is formed on the outer peripheral portion of the lock ring retainer 107. As shown in FIGS. The positioning protrusions 107a are arcuate and extend along the circumferential direction of the lock ring retainer 107, and a plurality of the positioning protrusions 107a are arranged at predetermined intervals in the circumferential direction of the lock ring retainer 107. As shown in FIG. Lock ring 106 is arranged in a space surrounded by a plurality of positioning protrusions 107a. The lock ring presser 107 abuts against the relative movement of the lock ring 106 in the radial direction by means of the positioning protrusion 107a, thereby centering the lock ring 106. As shown in FIG.

JP 2013-167326 A

However, in the process of snapping the cap 104 onto the joint body 102, the inner diameter of the cap 104 temporarily expands. Relative movement is more likely to occur. When the cap 104 is strongly pushed into the joint main body 102 in a state in which there is radial and axial misalignment between the lock ring 106 and the lock ring retainer 107 , the lock ring 106 is pushed into the lock ring retainer 107 . In particular, the positioning protrusion 107a may be scraped off. When the positioning protrusion 107a is largely scraped off, if the fragment enters between the resin pipe 151 and the seal ring 105, the watertightness of the pipe joint 101 is lowered.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pipe joint that can prevent fragments of positioning projections from adversely affecting watertightness.

In order to achieve the above object, the pipe joint of the first aspect of the invention comprises a retainer mechanism for holding a resin pipe in a joint body, and a retaining mechanism for securing watertightness between the joint body and the resin pipe. The retaining mechanism comprises a metal lock ring and a plurality of positioning protrusions formed on the outer periphery of the pipe joint. In a pipe joint provided with a synthetic resin lock ring retainer for centering a lock ring, the length of the positioning protrusion in the lock ring retainer in the circumferential direction is the axial direction of the seal ring and the resin pipe. It is set to 1.5 times or less of the seal length at .

In order to achieve the above-mentioned object, the pipe joint of the invention of claim 2 comprises: a retainer mechanism for holding a resin pipe in a joint body; and a synthetic resin member for attaching the retainer mechanism to the joint body. A pipe joint comprising a cap and a seal ring for ensuring watertightness between the joint body and the resin pipe, wherein the retaining mechanism includes a metal lock ring and a a lock ring holder made of synthetic resin for centering the lock ring in which the lock ring is arranged in a space surrounded by a plurality of positioning projections formed; and the cap snaps onto the joint body. In a pipe joint that is externally fitted by mating, the circumferential length of the positioning projection in the lock ring retainer is set to be equal to or less than the axial seal length between the seal ring and the resin pipe.

The pipe joint of the invention of claim 3 is characterized in that, in claim 1 or claim 2, the length of the positioning projection in the circumferential direction is 0.9 times or more the length of the seal between the seal ring and the resin pipe. is.

In the lock ring retainer of the present invention, the length of each positioning protrusion in the circumferential direction is set small. Therefore, even if the positioning projection is scraped off by the lock ring, the fragments are small, so even if the fragments enter between the seal ring and the resin pipe, they will not adversely affect the watertightness of the pipe joint. .

A vertical cross-sectional view of a pipe joint. FIG. 4 is a vertical cross-sectional view for explaining a pipe joint in the process of being assembled; FIG. 4 is an enlarged cross-sectional view of a main part explaining a state in which the lock ring is misaligned during assembly; The front view of a lock ring retainer (for 16A). The rear view of a lock ring retainer (for 16A). The right side view of a lock ring retainer (for 16A). The left side view of a lock ring retainer (for 16A). The top view of a lock ring retainer (for 16A). The bottom view of a lock ring retainer (for 16A). The front view of a lock ring retainer (for 10A). The front view of a lock ring retainer (for 13A). The front view of a lock ring retainer (for 20A). The front view of a lock ring retainer (for 25A). The front view of the lock ring retainer of another example. The back view of the lock ring retainer of another example. The right side view of the lock ring retainer of another example. The left side view of the lock ring retainer of another example. The top view of the lock ring retainer of example of another. The bottom view of the lock ring retainer of another example. The front view of the lock ring retainer of another example of another example. The front view of the lock ring retainer of another example of another example. FIG. 2 is an enlarged cross-sectional view of a main part of a conventional pipe joint; The front view of the conventional lock ring retainer.

An embodiment embodying the present invention will be described below.
As shown in FIG. 1, the pipe joint 11 includes two cylindrical joint bodies 12 to which resin pipes 51 are connected. Each joint main body 12 is made of synthetic resin such as polyphenylene sulfide resin. The resin pipe 51 is made of synthetic resin such as polyolefin (crosslinked polyethylene, polybutene, etc.).

One joint main body 12 and the other joint main body 12 are arranged so as to face opposite directions by 180 degrees on the same axis. One joint main body 12 and the other joint main body 12 have the same structure, and the one joint main body 12 and the other joint main body 12 are constructed with a one-touch joint having the same structure. Only the joint body 12 will be described, and the description of the other joint body 12 will be omitted.

The joint main body 12 has an inner cylindrical portion 14 and an outer cylindrical portion 15 which protrude from the inner and outer circumferences of the joint body 12 at intervals. The inner space of the inner cylindrical portion 14 forms a flow path 18 through which fluid such as water flows. An insertion space 13 into which the resin pipe 51 is inserted is formed between the inner tubular portion 14 and the outer tubular portion 15 . A step portion 15a is provided on the inner peripheral surface of the outer cylindrical portion 15 on the proximal end side. A locking step 15b is provided on the inner peripheral surface of the outer cylindrical portion 15 on the distal end side of the stepped portion 15a.

A seal ring retainer 16 made of polyacetal resin is engaged with the engaging step 15b. A seal ring 17 made of rubber such as ethylene-propylene-diene copolymer rubber is arranged in the space between the seal ring retainer 16 and the step portion 15a. When the resin pipe 51 is inserted into the insertion space 13, the seal ring 17 is crushed between the outer peripheral surface of the resin pipe 51 and the inner peripheral surface of the outer cylindrical portion 15, so that the two peripheral surfaces are watertight. Secured.

The length in the axial direction of the contact area between the seal ring 17 and the resin pipe 51 when the seal ring 17 is crushed is defined as "seal length S". The seal length S is approximately 2.2 mm for the pipe joint 11 corresponding to the resin pipe 51 with a nominal diameter of "10A", "13A" or "16A". The pipe joint 11 corresponding to the pipe 51 is about 2.5 mm, and the pipe joint 11 corresponding to the resin pipe 51 having a nominal diameter of "25A" is about 2.65 mm.

The wire diameter of the seal ring 17 is 3.6 mm for the pipe joint 11 corresponding to the resin pipe 51 with a nominal diameter of "10A", "13A" or "16A", and the nominal diameter is "20A". is 4.1 mm for the pipe joint 11 corresponding to the resin pipe 51 with a nominal diameter of "25A", and is 5 mm.

The pipe joint 11 includes a retainer mechanism 23 for holding the resin pipe 51 in the joint body 12 and a cap 20 for attaching the retainer mechanism 23 to the joint body 12 . The cap 20 is made of synthetic resin such as polyphenylene sulfide resin. Two locking grooves 21 are formed on the inner peripheral surface of the cap 20 . Two locking protrusions 19 are formed on the outer peripheral surface of the outer cylindrical portion 15 . The cap 20 is fitted onto the outer cylindrical portion 15 and connected to the outer cylindrical portion 15 by engaging the locking grooves 21 with the locking projections 19 of the outer cylindrical portion 15 . . In the cap 20, the inner peripheral surface of the distal end portion is provided with an inclined surface 22 whose diameter decreases toward the distal end side.

A lock ring 24 that constitutes the retainer mechanism 23 is made of a thin metal plate such as stainless steel and has an annular shape. A plurality of retainer pieces 24a are formed on the inner peripheral portion of the lock ring 24 so as to protrude toward the inner end side. Between the lock ring 24 and the cap 20, a split ring 26 is interposed that constitutes the retaining mechanism 23. As shown in FIG. The split ring 26 is made of synthetic resin such as polyphenylene sulfide resin. The split ring 26 backs up the inclination angle of the retaining piece 24 a of the lock ring 24 .

A lock ring retainer 25 constituting a retaining mechanism 23 is sandwiched between the seal ring retainer 16 and the cap 20 . A lock ring 24 is sandwiched between the lock ring retainer 25 and the split ring 26 . Assume that a pullout force is applied to the resin pipe 51 which is inserted into the insertion space 13 and passed through the split ring 26 and the lock ring 24 . In this case, the retaining pieces 24 a of the lock ring 24 bite into the outer peripheral surface of the resin pipe 51 , thereby preventing the resin pipe 51 from coming off from the pipe joint 11 . Further, in this case, the split ring 26 is guided by the inclined surface 22 of the cap 20 to reduce its diameter and tighten the outer peripheral surface of the resin pipe 51 , thereby preventing the resin pipe 51 from slipping out of the pipe joint 11 .

An insertion guide 29 made of synthetic resin such as polypropylene resin is arranged in the insertion space 13 . The insertion guide 29 is pushed by the tip of the resin pipe 51 and precedes the resin pipe 51 . Therefore, the insertion guide 29 allows the tip of the resin pipe 51 to smoothly pass through the split ring 26 , the lock ring 24 and the seal ring 17 .

A mounting groove 20a is annularly formed in the circumferential direction on the outer peripheral surface of the cap 20 . A cylindrical tightening cover 30 is engaged with the mounting groove 20 a of the cap 20 . The tightening cover 30 is made of metal such as stainless steel, and tightens the cap 20 to prevent the cap 20 from coming off from the joint main body 12 by making it difficult to expand the diameter.

Next, the lock ring retainer 25 will be described.
The lock ring retainer 25 is made of synthetic resin such as acetal resin and has an annular shape. The lock ring presser 25 positions (centers) the lock ring 24 .

A plurality of positioning protrusions 25a are formed on the front and rear outer peripheral portions of the lock ring retainer 25, respectively. The reason why the positioning protrusions 25a are provided on the front and rear surfaces of the lock ring retainer 25 is to eliminate the directionality of the front and back when the lock ring retainer 25 is assembled to the cap 20 . The lock ring 24 is arranged in a space surrounded by a plurality of positioning projections 25a on one of the front side and the back side of the lock ring retainer 25. As shown in FIG. The lock ring presser 25 abuts against relative movement of the lock ring 24 in the radial direction with the positioning protrusion 25 a to center the lock ring 24 . The length of each positioning protrusion 25a in the axial direction is about the same as the plate thickness of the lock ring 24, which is approximately 0.5 mm.

The lock ring retainer 25-16A shown in FIGS. 4 to 9 is for the pipe joint 11 corresponding to the resin pipe 51 having a nominal diameter of "16A". A crushing margin 25b is formed on the outer peripheral surface of the lock ring retainer 25-16A when it is press-fitted into the cap 20 and fixed. The outer peripheral side of each positioning protrusion 25a in the lock ring retainer 25-16A forms a convex curved surface smoothly connected to the outer peripheral surface of the lock ring retainer 25-16A.

The positioning projections 25a extend by a length X along the circumferential direction of the lock ring retainer 25-16A, and 10 of each on the front and back sides are spaced apart by a predetermined interval Y (main) in the circumferential direction of the lock ring retainer 25-16A. 7.78 mm in the embodiment).

The length X of each positioning protrusion 25a in the lock ring retainer 25-16A is set to be equal to or less than the seal length S (see FIG. 1, approximately 2.2 mm) between the seal ring 17 and the resin pipe 51. For example, 2 mm to It is set at 2.2 mm.

The length X of each positioning protrusion 25a in the lock ring retainer 25-16A is set smaller than the predetermined interval Y between the plurality of positioning protrusions 25a. The group of positioning protrusions 25a on the front and the group of positioning protrusions 25a on the back are arranged out of phase in the circumferential direction so that they do not overlap when viewed in the axial direction (see FIGS. 4 and 5 in particular). By doing so, it is possible to prevent the axial thickness of the lock ring retainer 25-16A from becoming excessively large at the portion of the positioning projection 25a. Therefore, during injection molding of the lock ring retainer 25-16A, for example, the flow of the resin material in the circumferential direction can be made smooth, and the occurrence of molding defects (for example, sink marks) can be prevented.

Next, lock ring holders 25-10A, 25-13A, 25-20A, and 25-25A of the pipe joint 11 corresponding to the resin pipes 51 with nominal diameters of "10A", "13A", "20A", and "25A" , differences from the lock ring retainer 25-16A described above will be described. Of course, the inner and outer diameters of the lock ring presser 25 increase in the order of 25-10A, 25-13A, 25-16A, 25-20A, and 25-25A.

As shown in FIG. 10, the lock ring retainer 25-10A has eight positioning projections 25a on the front and back. The length X of each positioning protrusion 25a is set to be equal to or less than the sealing length S (see FIG. 1, approximately 2.2 mm) between the seal ring 17 and the resin pipe 51, and is set to 2 mm to 2.2 mm, for example. there is A predetermined interval Y between the plurality of positioning protrusions 25a is 6.31 mm.

As shown in FIG. 11, the lock ring retainer 25-13A has eight positioning projections 25a on the front and back. The length X of each positioning protrusion 25a is set to be equal to or less than the sealing length S (see FIG. 1, approximately 2.2 mm) between the seal ring 17 and the resin pipe 51, and is set to 2 mm to 2.2 mm, for example. there is A predetermined interval Y between the plurality of positioning protrusions 25a is 7.88 mm.

As shown in FIG. 12, the lock ring retainer 25-20A has 12 positioning projections 25a on each of its front and rear surfaces. The length X of each positioning projection 25a is set smaller than the sealing length S (see FIG. 1, approximately 2.5 mm) between the seal ring 17 and the resin pipe 51, for example, 2.3 mm to 2.5 mm. is set. A predetermined interval Y between the plurality of positioning protrusions 25a is 7.22 mm.

As shown in FIG. 13, the lock ring holder 25-25A has 12 positioning projections 25a on each of the front and rear surfaces. The length X of each positioning protrusion 25a is set to be smaller than the sealing length S (see FIG. 1, approximately 2.65 mm) between the seal ring 17 and the resin pipe 51, for example 2.45 mm to 2.65 mm. is set. A predetermined interval Y between the plurality of positioning protrusions 25a is 8.01 mm.

Next, assembly of the pipe joint 11 will be described.
FIG. 2 shows a state before the cap 20 is attached to the joint body 12. FIG. In this state, the seal ring 17 is arranged in the insertion space 13 of the joint main body 12, and the seal ring retainer 16 is press-fitted into the outer cylindrical portion 15, so that the seal ring retainer 16 abuts the seal ring 17 when it comes out. Regulated. Further, in the cap 20, the lock ring 24 and the split ring 26 are arranged inside, and the lock ring retainer 25 is press-fitted into the inner peripheral surface of the cap 20, so that the lock ring 24 and the split ring 26 can be pulled out. are regulated by the lock ring retainer 25.

The sub-assembly consisting of the joint main body 12, the seal ring retainer 16, the seal ring 17 and the insertion guide 29, and the sub-assembly consisting of the cap 20, the lock ring 24, the lock ring retainer 25 and the split ring 26 are pressed through a pressing process. be integrated. In the pressing process, the joint body 12 is pressed against the cap 20 , thereby snap-engaging the cap 20 with the outer cylindrical portion 15 of the joint body 12 . After the pressing process, a tightening cover 30 (see FIG. 1) is attached to the cap 20. As shown in FIG.

Here, in the process of snap-engaging the cap 20 with the joint body 12 in the pressing process, the inner diameter of the cap 20 is temporarily expanded. Therefore, relative movement between the lock ring 24 and the lock ring retainer 25 in the radial direction and the axial direction is likely to occur.

As shown in FIG. 3, when the cap 20 is strongly pushed into the joint main body 12 in a state where the lock ring 24 and the lock ring retainer 25 are displaced in the radial direction and the axial direction, the lock ring 24 is released. In some cases, the inner edge 25a-1 at the tip of the positioning projection 25a of the lock ring retainer 25 is scraped off. Fragments of the scraped positioning projection 25a may enter between the resin pipe 51 and the seal ring 17 when the resin pipe 51 is inserted into the pipe joint 11 .

However, in the lock ring retainer 25 of this embodiment, the length X of each positioning protrusion 25a is set to be equal to or less than the seal length S between the seal ring 17 and the resin pipe 51. As shown in FIG. Therefore, for example, even if the tip inner edge 25a-1 of the positioning projection 25a is scraped off by the length X in the circumferential direction by the lock ring 24 and the fragment enters between the seal ring 17 and the resin pipe 51, the fragment will not be removed. At the portion where the pipe joint 11 enters, the water passage is not opened in the longitudinal direction of the seal ring 17, and thus the watertightness of the pipe joint 11 can be prevented from deteriorating.

In addition, if the length X of the positioning projection 25a is the same as the sealing length S between the seal ring 17 and the resin pipe 51, theoretically, the length X of the piece of the positioning projection 25a defines the sealing length S. If you enter the area exactly where the debris enters, there is a high possibility that the waterway will open at the part where the fragment entered. However, it is unlikely that the positioning protrusion 25a will be scraped off by the length X, and much less likely that the fragment will fit into the range that defines the seal length S, so there is no problem in actual use. can be said to be in In this sense, the length X of the positioning projection 25a should be 1.5 times or less the length S of the seal between the seal ring 17 and the resin pipe 51 .

In addition, if the length X of the positioning projection 25a is small, the fragments of the positioning projection 25a tend to be small, so that the deterioration of the watertightness caused by the fragments can be prevented more effectively. However, if the length X of the positioning protrusion 25a is too small, the durability of the positioning protrusion 25a is reduced, or the positioning protrusion 25a is likely to be scraped off by the lock ring 24 . In consideration of these considerations, the length X of the positioning projection 25a is preferably 0.9 times or more the seal length S between the seal ring 17 and the resin pipe 51 .

(Another example)
The above embodiment can be modified, for example, as follows.
○ As shown in FIGS. 14 to 19, three positioning protrusions 25a are arranged continuously in the circumferential direction. In this case, the tip inner edge 25a-1 of each of the three positioning protrusions 25a should not be continuous with the tip inner edge 25a-1 of the other adjacent positioning protrusion 25a in the circumferential direction.

In this way, the circumferential length (=X+X+X) of the three positioning protrusions 25a as a whole is set to greatly exceed 1.5 times the seal length S (see FIG. 1) and locked. The ring 24 (see FIG. 1) can be stably centered, and the length X' (<X) of the tip inner edge 25a-1 of each positioning projection 25a, which is particularly likely to be scraped off, should be 1.5 times or less than the seal length S. , it is also possible to prevent the watertightness from deteriorating as described above.

The number of positioning projections 25a that are continuous in the circumferential direction may be a plurality other than three, for example, two as shown in FIG. 20 or four as shown in FIG. There may be 5, 6, 7, 8, 9 or 10.

○ As shown in FIGS. 14 to 21, the lock ring 24 (see FIG. 1) has a circumferential length of the outer circumference of the lock ring 24 (see FIG. 1) for a predetermined circumferential interval Y between adjacent and discontinuous positioning protrusions 25a. The length should be less than the length divided by the number of retaining pieces 24a. In this way, for example, when the lock ring 24 is broken in the radial direction and each of the retaining pieces 24a becomes a single fragment, the length of the outer peripheral edge of the fragment in the circumferential direction is the predetermined interval Y will exceed Therefore, it is possible to prevent the fragment from slipping out of the predetermined space Y in the radial direction, and the fragment can be held inside the positioning protrusion 25a of the lock ring retainer 25 (25-16A), and eventually escape. The function of the stopper piece 24a can be maintained, and the resin pipe 51 (see FIG. 1) can be prevented from coming off.

○ Although the pipe joint 11 is a so-called outer diameter seal joint, it may be embodied as an inner diameter seal joint.
◯ The group of positioning projections 25a on the front and the group of positioning projections 25a on the back are arranged so that the corresponding positioning projections 25a partly or wholly overlap each other when viewed in the axial direction.

○ The pipe joint 11 was constructed by integrating two subassemblies in a press process (see Fig. 2). By changing this, for example, the seal ring 17, the seal ring retainer 16, the lock ring retainer 25, the lock ring 24, and the split ring 26 are assembled in the same order to the joint body 12, and then the cap 20 alone is attached to the joint body 12. shall be configured so that they are assembled together. In this case, it is not necessary to hold the lock ring 24 and the split ring 26 in the cap 20 alone. The ring retainer 16 may also serve as a "lock ring retainer".

(Appendix)
A technical idea that can be grasped from the above embodiment will be described.
(1) A plurality of positioning projections are formed on the front and back outer peripheral portions of the lock ring retainer, respectively, and the lock ring is surrounded by the plurality of positioning projections on one of the front and the back. The group of positioning projections on the front surface and the group of positioning projections on the back surface are arranged with a phase shift in the circumferential direction so that they do not overlap when viewed in the axial direction. The pipe joint according to any one of claims 1 to 3.

(2) A pipe joint comprising a retaining mechanism for holding a resin pipe in a joint body and a seal ring for ensuring watertightness between the joint body and the resin pipe, The retaining mechanism consists of a metal lock ring and a synthetic resin lock ring retainer that centers the lock ring by placing the lock ring in a space surrounded by a plurality of positioning projections formed on the outer periphery. , the length in the circumferential direction of the tip inner edge of the positioning projection in the lock ring retainer is 1.5 times or less the seal length in the axial direction between the seal ring and the resin pipe. Fittings that are set to

(3) between the retaining mechanism for retaining the resin pipe in the joint body, the synthetic resin cap for attaching the retaining mechanism to the joint body, and the joint body and the resin pipe; and a seal ring for ensuring the watertightness of the pipe joint, wherein the retaining mechanism is located in a space surrounded by a metal lock ring and a plurality of positioning projections formed on the outer periphery of the A pipe joint in which a lock ring is disposed and a synthetic resin lock ring retainer for centering the lock ring is provided, and the cap is externally fitted to the joint body by snap engagement, wherein the lock ring retainer wherein the length in the circumferential direction of the tip inner edge of the positioning projection is set to be equal to or less than the seal length in the axial direction between the seal ring and the resin pipe.

DESCRIPTION OF SYMBOLS 11... Pipe joint, 12... Joint main body, 17... Seal ring, 20... Cap, 23... Retaining mechanism, 24... Lock ring, 25... Lock ring holder, 25a... Positioning projection, 51... Resin pipe.

Claims (3)

A pipe joint comprising a retaining mechanism for retaining a resin pipe in a joint body and a seal ring for ensuring watertightness between the joint body and the resin pipe, wherein the retaining mechanism has a metal lock ring and a synthetic resin lock ring retainer for centering the lock ring by placing the lock ring in a space surrounded by a plurality of positioning projections formed on the outer periphery. In pipe joints with
A pipe joint according to claim 1, wherein the length of the positioning protrusion in the lock ring retainer in the circumferential direction is set to 1.5 times or less of the seal length in the axial direction between the seal ring and the resin pipe. A retention mechanism for holding a resin pipe in a joint body, a synthetic resin cap for attaching the retention mechanism to the joint body, and watertightness between the joint body and the resin pipe The retaining mechanism includes a metal lock ring and a plurality of positioning protrusions formed on the outer periphery of the pipe joint. A pipe joint comprising a synthetic resin lock ring retainer arranged to center the lock ring, wherein the cap is externally fitted to the joint body by snap engagement,
A pipe joint, wherein a length in a circumferential direction of the positioning projection in the lock ring retainer is set to be equal to or less than a sealing length in an axial direction between the seal ring and the resin pipe. 3. The pipe joint according to claim 1, wherein the length of the positioning protrusion in the circumferential direction is 0.9 times or more the seal length between the seal ring and the resin pipe.

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