JP6709597B2 - Pipe fitting - Google Patents

Description

The present invention relates to a pipe joint used for piping a fluid such as gas.

In the field of gas and water pipes, steel pipes (white gas pipes) are used for main pipes buried in the ground and supply pipes branched therefrom, and thermoplastic resin (for example, polyethylene) is used on the outer surface to improve corrosion resistance. ) Lined steel pipes (hereinafter collectively referred to simply as "steel pipes") are used. Moreover, in recent years, polyethylene pipes, which are thermoplastic resin pipes having further excellent corrosion resistance and earthquake resistance, have been widely used.

When a polyethylene pipe is newly installed, the pipe must be converted by connecting the existing steel pipe main pipe or supply pipe to the polyethylene pipe. Therefore, Patent Document 1 proposes and puts into practical use a relay joint (see FIG. 4) for converting a steel pipe into a polyethylene pipe. The relay joint 32 described in Patent Document 1 includes a steel pipe connecting portion connected to an end of an existing steel pipe M, and a polyethylene short pipe (outer body 40) at the opposite end. Here, description will be given using the reference numerals used in Patent Document 1. According to the relay joint described in Patent Document 1, by connecting the steel pipe connecting portion to the end of the existing steel pipe M, the end of the steel pipe M is converted into the short pipe 40 made of polyethylene, and the converted polyethylene pipe is made. The short pipe 40 and the new polyethylene pipe P are connected by the electric fusion joint 4. The steel pipe connecting portion of the relay joint 32 includes a nut member 36 for passing the steel pipe M to the inner diameter side, an inner body 38 into which the nut member 36 is screwed, and an outer surface of the steel pipe M as the nut member 36 is screwed into the inner body 38. It is provided with a fixing means 56 (lock ring) for preventing the steel pipe from slipping off and a sealing means 60. In the relay joint 32, the end portion of the steel pipe M is inserted by a predetermined length and the nut member 36 is screwed in, so that the fixing means 56 is reduced in diameter and bites the outer surface of the steel pipe M, so that the steel pipe M is securely prevented from coming off. . At this time, the fixing means 56 that bites on the outer surface of the steel pipe M is pushed by the nut member 36 and moves while drawing the steel pipe M into the inner side of the inner body 38. Further, along with this movement, the sealing means 60 is compressed between the inner main body 38 and the fixing means 56 to reliably seal the space between the steel pipe M and the inner main body 38.

JP 2004-183793 A

In the relay joint 32 described in Patent Document 1, the inner diameter of the inner main body 38 forming the steel pipe connecting portion to which the steel pipe M is connected is provided over the entire length larger than the outer diameter of the steel pipe, and the nut member 36 is provided in the inner main body 38. Since there is no factor that hinders the movement of the steel pipe M inside the inner body 38 when screwed in, the steel pipe M can be drawn toward the inner side of the inner body 38. On the other hand, the one with a positioning step that regulates the insertion amount of the steel pipe at the steel pipe connection part of the relay joint, and the mechanical connection structure similar to the steel pipe connection part on both sides of the relay joint, and the end of the pipe inserted from both sides. In the case of parts abutting each other, the movement of the steel pipe due to the screwing of the nut member is hindered, so the compression of the sealing means due to the movement of the fixing means may be insufficient and the connection of the steel pipe may be incomplete. . Therefore, at the time of the piping work, it is necessary to manage the insertion length of the steel pipe by marking the inserted steel pipe with a marked line indicating the insertion amount and the like, which makes the piping work complicated.

The present invention has been made in view of the above-mentioned problems of the prior art, and it is possible to make the insertion amount of the pipe constant without writing a marked line indicating the insertion amount of the pipe in advance, and the joint accompanying the connection work. An object of the present invention is to provide a pipe joint that can pull a pipe to the inner side and can reliably connect the pipe.

In order to achieve the above object, the pipe joint of the present invention includes a joint body into which a pipe is inserted, a push ring attached to an end of the joint body, and the pipe by pushing the push ring into the joint body. A retaining member having a tooth portion that digs into the outer surface of the joint body to prevent the pipe from coming out of the joint body, a seal member that seals between the inner surface of the joint body and the outer surface of the pipe, and the joint body. In a pipe joint comprising a stopper member for positioning the pipe inserted into the joint body before pushing the push ring,
The stopper member is an annular plate-like member, and is formed on an outer periphery of the annular positioning portion and an annular positioning portion with which the end of the pipe abuts when the pipe is inserted into the joint body . Equipped with convex parts ,
The joint body includes stopper fixing means formed of an annular stopper mounting groove in which the stopper member is mounted in the joint body by fitting the convex portion,
The stopper member is
Before the push ring is pushed into the joint body, the convex portion is fitted and fixed in the annular stopper mounting groove,
Wherein when the the joint body pressing ring is pushed, the positioning portion of the annular is pushed to the end of the tube, by the convex portion is disengaged from the stopper attachment groove of the annular, inner part of the joint body and it is characterized in movable der Rukoto the side.

According to the pipe joint of the present invention, the push ring is pushed into the joint body with the pipe inserted, so that the retaining member bites into the outer surface of the pipe to connect the pipe and the pipe joint. The pipe inserted into the pipe joint before the push ring is pushed is positioned with the pipe end in contact with the stopper member, and is inserted into the pipe joint by a predetermined insertion amount. When the push ring is pushed into the joint body, the positioning portion is pushed by the end portion of the pipe and moves to the inner side of the joint body. The term "movement" in the present invention excludes the form in which the stopper member is deformed .

According to the pipe joint of the present invention, since the stopper member having the positioning portion with which the end of the pipe abuts is provided, the inserted pipe can be inserted into the pipe joint by a predetermined length without marking lines or the like. Positioned. Further, the stopper member is provided such that when the push ring is pushed into the joint body, the positioning portion is pushed by the end portion of the pipe so as to be movable to the inner side of the joint body, and the movement of the pipe is restrained to seal the pipe. Since it can be prevented from becoming insufficient, a reliable pipe connection is possible.

It is a front view which shows the pipe joint of 1st Embodiment. It is an AA sectional view of the pipe joint of FIG. It is a front view and BB sectional drawing of a stopper member used for the pipe joint of FIG. It is a sectional view showing a relay joint concerning conventional technology.

Embodiments for carrying out the present invention will be described in detail below with reference to the drawings. The embodiments described here are merely examples, and the embodiments of the present invention are not limited to the embodiments described here.

(First embodiment)
FIG. 1 is a front view showing a pipe joint according to an embodiment of the present invention. FIG. 2 is a sectional view showing an AA section of the pipe joint of FIG.

In the pipe joint 1 shown in FIGS. 1 and 2, an existing steel pipe (pipe P1) is connected on the left side, and a new polyethylene pipe (not shown) is connected on the right side by a connecting means such as an electric fusion joint.

The pipe joint 1 includes a joint body 2 into which an existing steel pipe P1 (pipe P1) is inserted from the left side of the figure, a push ring 3 attached to an end of the joint body, and an outer surface of the pipe by pushing the push ring into the joint body. A retaining member 4 for preventing the bite pipe from coming off, a seal member 5 for sealing between the outer surface of the pipe and the inner surface of the joint body, and a stopper member for positioning the pipe inserted before pushing the push ring into the joint body. 6 and.

The joint body 2 is a hollow member into which the pipe P1 is inserted, and on the side to which the left steel pipe is connected, the stopper mounting groove 21 into which the stopper member 6 is mounted from the back side, and the seal in which the seal member is housed. A concave portion 23 into which the convex portion of the member receiving portion 22 and the push wheel 3 is pushed is formed, and a joint flange portion 24 for fastening the push wheel 3 is formed on the outer peripheral portion of the concave portion 23. On the other hand, a polyethylene short pipe 25 for connecting a polyethylene pipe P2 (not shown) is attached to the right end of the joint body. The short pipe 25 made of polyethylene is inserted into the end portion of the joint body with the metal stiffener 26 mounted inside, and the stiffener 26 is expanded by hydraulic bulge processing or rubber bulge processing, so that the inner surface of the joint body 2 is expanded. It is pressed against and firmly fixed.

The push ring 3 is a hollow member through which the pipe P1 passes, and has a convex portion 31 that is pushed into the concave portion 23 of the joint body 2. A taper portion 32 is formed on the inner side of the convex portion 31 so as to increase in diameter toward the end. When the push ring 3 is pushed into the joint body 2, the taper portion 32 reduces the diameter of a retaining member 4 described below to bite into the outer surface of the pipe P1. A push ring flange portion 33 that faces the joint flange portion 24 of the joint body 2 is formed on the outer peripheral portion of the push ring 3. The joint flange portion 24 and the push ring flange portion 33 are provided with bolts (not shown) for tightening. A bolt hole is formed through which the push ring 3 is pushed into the joint body 2 by tightening a fastening bolt (not shown) and a nut 34 with the joint flange portion 24 and the push wheel flange portion 33 interposed therebetween. A watertight packing 7 is attached to the outer end of the push ring 3 to prevent water from entering the joint from the outside.

The retaining member 4 is composed of a ring-shaped member 41 having teeth formed on the outer surface of the pipe P1 and a holding member 42 for holding the ring-shaped member. When the push ring 3 is pushed into the joint body 2, the ring-shaped member 41 is reduced in diameter by the tapered portion 32, and the tooth portion bites into the outer surface of the pipe P1. The outer diameter dimension of the ring-shaped member 41 is set larger than the inner diameter dimension of the tapered portion 32, and even if a force acts on the pipe P1 in the direction of pulling out from the pipe joint 1, the pipe P1 does not come out of the pipe joint 1. Absent.

The seal member 5 is attached so as to be in close contact with the outer surface of the pipe P1, and is attached to the seal member accommodating portion 22 of the joint body 2. The seal member 5 is compressed between the retaining member 4 and the joint body 2 by pushing the push ring 3 into the joint body 2, and seals between the inner surface of the joint body and the outer surface of the pipe P1.

As shown in FIGS. 2 and 3, the stopper member 6 is an annular plate-shaped member including a positioning portion 61 with which the end of the pipe P1 abuts when the pipe P1 is inserted before the push wheel 3 is pushed in. Is. A plurality of convex portions 62 are formed on the outer circumference of the stopper member 6. The stopper member 6 is mounted and fixed at a predetermined position inside the joint body 2 where the end of the inserted pipe P1 reaches before the push ring 3 is pushed into the joint body 2. The stopper member 6 is fixed at a predetermined position inside the joint body 2 by fitting at least a part of the outer periphery of the stopper member 6 into a stopper fixing means formed of an annular stopper mounting groove 21 formed in the joint body. To be done. The stopper member 6 can position the end portion of the pipe P1 when the pipe P1 is inserted, and allows the pipe to be pulled in when the pipe is pulled in at the time of connecting the pipe P1. Is movably provided when pushed at the end of the pipe P1 and can be made of a synthetic resin material such as polyethylene.

The stopper fixing means is not limited to the embodiment shown in FIGS. 2 and 3, and any means capable of fixing the position of the stopper member 6 in the joint body 2 in a state before the push ring 3 is inserted into the joint body 2. Can be adopted. For example, a step having an inner diameter smaller than the outer diameter of the stopper member 6 may be provided at the position where the stopper member 6 is mounted inside the joint body 2 to serve as a stopper fixing means, or the outer diameter of the stopper member 6 and the joint body. The stopper fixing means may be provided by fitting the stopper member 6 so that the stopper member 6 does not move easily.

In the pipe joint 1 of the present embodiment, the outer surfaces of the joint body 2 and the push ring 3 are formed of a metal material such as black-core malleable cast iron with a synthetic resin coating 27 for preventing corrosion.

Next, a procedure for connecting the pipe P1 to the pipe joint 1 will be described.
(1) Attachment of stopper member to joint body The stopper body 6 is attached so that the convex portion 62 of the stopper member 6 fits in the stopper attachment groove 21 inside the joint body 2. The stopper member 6 may be attached in advance.

(2) Insertion of pipe into push ring The pipe P1 is passed through the push ring 3 on the inner diameter side, and the retaining member 4 and the seal member 5 are fitted on the outer periphery of the pipe P1. In this state, the pipe P1 is inserted until the end of the pipe hits the stopper member 6. At this time, the seal member 5 fits in the seal member housing portion 22 of the joint body 2.

(3) Pushing the push ring into the joint body The protrusion 31 of the push ring 3 is mounted so as to fit in the recess 23 of the joint body 2, and a bolt (not shown) and a nut 34 are tightened. By tightening the bolts and nuts 34, the push ring 3 is pushed into the joint body 2, and the tapered portion 32 reduces the diameter of the retaining member 4, so that the tooth portion formed on the inner diameter side of the retaining member 4 has the tooth portion of the pipe P1. Bite outside. When the bolts and nuts 34 are tightened further, the seal member 5 is compressed in the seal member accommodating portion 22 as the push wheel 3 moves.

In the work of connecting the pipe P1 to the pipe joint 1, when the push ring 3 moves with respect to the joint body 2, the pipe P1 also receives a force that is pulled toward the rear side of the joint body 2. In the pipe joint 1, since the stopper member 6 is movably provided by being pushed by the end portion of the pipe, the pipe P1 can move toward the inner side of the joint body. Further, the retaining member 4 moves together with the pipe P1, and the retaining member 4 can sufficiently compress the seal member 5, so that the pipe P1 can be completely connected. Thus, by providing the stopper member 6 so as to be movable, even if it is a pipe joint for connecting pipes whose ends are opposed to each other, the seal member can be compressed sufficiently without considering the pulling margin of the pipe. It is possible to obtain a reliable seal.

Further, according to the pipe joint 1 of the present embodiment, the joint body 2 and the push ring 3 have a flange structure, so that the pipes can be connected without using a pipe wrench, and the work space is small. Suitable for connecting pipes in narrow spaces. Furthermore, it is preferable to have a general-purpose tool for tightening the bolts and nuts so that the pipes can be connected.

(Second embodiment)
Pushing the push ring into the joint body may be performed by a screw formed on the joint body and a male screw formed on the push ring, as in the relay joint described in Patent Document 1 shown in FIG.

P1: Steel pipe (pipe), P2: Polyethylene pipe 1: Pipe joint,
2: Joint body, 21: Stopper mounting groove, 22: Seal member accommodating portion 23: Recessed portion, 24: Joint flange portion, 25: Short pipe, 26: Stiffener 27: Synthetic resin coating 3, 3A: Push ring, 31: Convex portion , 32: taper portion, 33: push ring flange portion 34: nut, 35: synthetic resin coating 4: retaining member, 41: ring-shaped member, 42: holding member 5, sealing member 6: stopper member, 61 positioning portion, 62 : Convex 7: Watertight packing

Claims (3)

The pipe from the joint body having a joint body into which a pipe is inserted, a push ring attached to an end portion of the joint body, and a tooth portion that bites into the outer surface of the pipe by pushing the push ring into the joint body. A retaining member for preventing the slip-off, a sealing member for sealing between the inner surface of the joint body and the outer surface of the pipe, and the pipe inserted into the joint body before pushing the push ring into the joint body. In a pipe joint including a stopper member for positioning,
The stopper member is an annular plate-like member, and is formed on an outer periphery of the annular positioning portion and an annular positioning portion with which the end of the pipe abuts when the pipe is inserted into the joint body . Equipped with convex parts ,
The joint body includes stopper fixing means formed of an annular stopper mounting groove in which the stopper member is mounted in the joint body by fitting the convex portion,
The stopper member is
Before the push ring is pushed into the joint body, the convex portion is fitted and fixed in the annular stopper mounting groove,
Wherein when the the joint body pressing ring is pushed, the positioning portion of the annular is pushed to the end of the tube, by the convex portion is disengaged from the stopper attachment groove of the annular, inner part of the joint body pipe joint characterized by movable der Rukoto the side. A joint flange is formed on the outer periphery of the end of the joint body,
A push ring flange portion is formed on the outer periphery of the push ring,
The joint flange portion and the push ring flange portion are formed with bolt holes through which fastening bolts pass,
The pipe joint according to claim 1, wherein the push ring is pushed into the joint body by tightening the bolt and the nut passed through the flange portion. The joint body and the push ring are provided so that they can be screwed into each other,
The pipe fitting according to claim 1 or 2 , wherein the push ring is pushed into the joint body by being screwed into the joint body.

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