JP2013200024A - Pipe joint structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a connection space for a pipe end part of a pipe to be connected, in a pipe joint structure including a joint pipe structure or a cap structure.SOLUTION: A pipe joint structure 1 connects a joint member 3 including a mechanical joint part 30 at the end of a pipe 2 to be connected, and includes a fall-off prevention member 4 fixed to an inner surface of the end part of the pipe 2 to be connected. The joint member 3 includes a locking part 3A that is inserted into the pipe 2 to be connected and is locked to the fall-off prevention member 4.

Description

  The present invention relates to a pipe end joint structure including a pipe end cap connected to a pipe end and a connection joint.

  Conventionally, a mechanical joint structure as shown in FIG. 1A is known as a joint structure for connecting a polyethylene pipe (PE pipe) and a cast iron pipe. In this joint structure, a joint member or cast iron pipe J2 connected to the end of the PE pipe J1 includes a mechanical joint J20 having a flange fastening part J21. A reinforcing member J10 is driven into the end portion of the PE pipe J1 to increase the rigidity of the end portion, and a retaining ring J11 (lock ring J11a, coloring ring J11b) is attached to the outer periphery of the end portion. . The end portion is inserted into the mechanical joint portion J20 in a state where the presser wheel J15 is passed through the end portion of the PE pipe J1. A sealing member such as a backup ring J22, a rubber ring J23 (round rubber ring J23a, a square rubber ring J23b), a washer J24, or the like is inserted between the inner surface of the mechanical joint J20 and the outer peripheral surface of the PE pipe J1. A bolt J25 is tightened with a nut J26 through a bolt fastening hole J21a of a flange fastening portion J21 and a bolt fastening hole J15a of a press ring J15 so as to push a washer J24 with a rib portion (see Patent Document 1 below).

  Conventionally, a fusion cap structure as shown in FIG. 1B is known as a cap structure for closing the end of the PE pipe J1. This cap structure has a receiving part J30, and uses a cap member J3 having an exothermic wire J32 on the inner surface of the receiving part J30, and inserts the end of the PE pipe J1 into the inside of the receiving part J30 of the cap member J3. The cap member J3 is fused and connected to the end of the PE tube J1 by applying a voltage to the lead wire J32a of the heating wire J32 drawn from the terminal portion J33 of the cap member J3 (see Patent Document 2 below). .

JP-A-10-132168 JP-A-11-210978

  The mechanical joint structure as shown in FIG. 1A includes a space for mounting a retaining ring J11 (lock ring J11a, coloring ring J11b) on the outer periphery of the end of a connection target pipe (for example, PE pipe J1), and a backup ring. A space for providing sealing members such as J22, rubber ring J23 (round rubber ring J23a, square rubber ring J23b), and washer J24 is required. For this reason, a relatively long space required for connection from the pipe end of the pipe to be connected along the pipe axis is required, and in the case of a buried pipe, time and labor are required for excavating the pipe end, and the joint structure itself There is a problem that good workability cannot be obtained due to the increase in size.

  On the other hand, the fusion cap structure as shown in FIG. 1 (b) is used, for example, for temporary closure when performing replacement work from a cast iron pipe to a PE pipe. In this case, replacement work proceeds. Each time the end of the PE tube is cut, the fusion cap portion is discarded. According to this, time and labor are required for the fusion work of the fusion cap part, and the disposal of a large amount of waste generated as the construction progresses becomes a problem.

  This invention makes it an example of a subject to cope with such a problem. In other words, in pipe joint structures including connection joint structures and cap structures, the connection space at the pipe end of the pipe to be connected is shortened, the joint structure is downsized to improve the workability of the connection work, cast iron It is an object of the present invention to improve workability in replacement work from a pipe to a PE pipe, to obtain a reusable cap structure without producing waste during construction.

  In order to achieve such an object, the pipe joint structure according to the present invention has at least the following configuration.

  A pipe joint structure for connecting a joint member having a mechanical joint portion to an end of a connection target pipe, comprising a retaining member that is fixed to an inner surface of the end of the connection target pipe, and the joint member is provided in the connection target pipe. A pipe joint structure comprising a locking portion that is inserted into the locking member and locked to the retaining member.

  In the pipe joint structure having such a feature, the retaining member is fixed to the inner surface of the end portion of the connection target pipe, thereby fixing the sealing member of the mechanical joint portion disposed on the outer peripheral surface of the connection target pipe to the retaining member. Can be deployed over the location. Thereby, the connection space required at the pipe end of the connection target pipe can be shortened as compared with the conventional joint structure in which the retaining member and the sealing member of the mechanical joint portion are arranged side by side on the outer peripheral surface of the connection target pipe.

  In addition, as described above, since it is not necessary to arrange the retaining member and the sealing member of the mechanical joint portion side by side on the outer peripheral surface of the connection target pipe, the joint member should be configured to be short along the tube axis of the connection target pipe. Thus, a small and lightweight joint member can be obtained. Thereby, the workability of the pipe joint connection work can be improved.

  In addition, when the cap member having the structure of the joint member described above is used to close the pipe end in the replacement work from the cast iron pipe to the PE pipe, the cap can be reused without generating waste during construction. A structure can be obtained.

It is explanatory drawing of a prior art. It is explanatory drawing which showed the pipe joint structure which concerns on one Embodiment of this invention. It is explanatory drawing which showed the pipe joint structure which concerns on one Embodiment of this invention. It is explanatory drawing which showed the pipe joint structure which concerns on other embodiment of this invention. It is explanatory drawing which showed the pipe joint structure which concerns on other embodiment of this invention. It is explanatory drawing which showed the structural example of the retaining member in embodiment of this invention. It is explanatory drawing which showed the modification of the retaining member in embodiment of this invention. It is explanatory drawing which showed the other example of the pipe joint structure which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 2 and 3 are explanatory views showing a pipe joint structure according to an embodiment of the present invention. The pipe joint structure 1 connects a connection target pipe (for example, a polyethylene pipe) 2 and a joint member 3 including a mechanical joint portion 30. The joint structure 1 includes a retaining member 4 that is fixed to the inner surface of the end of the connection target pipe 2, and includes a locking portion 3 </ b> A that the joint member 3 is inserted into the connection target pipe 2 and is locked to the retaining member 4. I have.

  The retaining member 4 is expanded in diameter by inserting the members 4-1 and 4-2 on the half ring into the connection target pipe 2 from the end, connecting them with the fastener 5, for example, and rotating the fastener 5. Thus, it is fixed to the inner surface of the connection target pipe 2. The retaining member 4 includes an insertion portion 4a through which a locking portion 3A extending along the tube axis direction of the connection target pipe 2 is inserted and a locked portion 4b into which the locking portion 3A is locked. Yes.

  The joint member 3 is integrally provided with a plurality of claw-shaped locking portions 3A on the inner surface. The coupling member 3 is rotated around the tube axis of the connection target pipe 2 in a state in which the locking portion 3A is passed through the insertion portion 4a of the locking member 4 so that the locking portion 3A is locked by the locking member 4 It can be locked to the portion 4b.

  The mechanical joint portion 30 has a well-known structure, and a sealing member 31 (31A, 31B, 31C) is provided between the inner surface of the mechanical joint portion 30 and the outer peripheral surface of the connection target pipe 2, and the connection target pipe 2 A push ring 32 for pressing the sealing member 31 is provided on the outer periphery. By fastening the flange portion 3B of the mechanical joint portion 30 and the flange portion 32A of the press ring 32 with bolts and nuts 33, the press ring 32 presses the sealing member 31 and the inner surface of the mechanical joint portion 30 and the connection target pipe 2 The space between the outer peripheral surfaces is hermetically sealed.

  According to such a pipe joint structure 1, by fixing the retaining member 4 to the inner surface of the connection target pipe 2, the space where the retaining member 4 is disposed and the mechanical joint portion 30 at the end of the connection target pipe 2. Spaces for disposing the sealing member 31 can be overlapped, and the end length L of the connection target pipe 2 required for connection can be shortened. Moreover, since the length of the whole joint member 3 in the pipe joint structure 1 can be shortened, the joint member 3 reduced in size and weight can be used. Thereby, the handleability of the joint member 3 is improved, and the workability of the pipe joint work can be improved.

  In such a pipe joint structure 1, the joint member 3 is a connection joint member that connects the end of the connection target pipe 2 and the end of the connection target pipe, the connection target pipe 2 is a polyethylene pipe, and the connection target The target pipe can be a cast iron pipe. In addition, the joint member 3 itself can be formed at the end of a pipe to be connected (for example, a cast iron pipe).

  4 and 5 are explanatory views showing a pipe joint structure according to another embodiment of the present invention. The pipe joint structure 1 </ b> A connects the connection target pipe 2 and the joint member 3 including the mechanical joint part 30, as in the above-described embodiment. The pipe joint structure 1 </ b> A is connected to the inner surface of the end of the connection target pipe 2. The locking member 4 is provided, and the coupling member 3 is inserted into the connection target pipe 2 and includes a locking portion 3 </ b> A that locks the locking member 4. The same parts as those in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.

  In this pipe joint structure 1 </ b> A, the retaining member 4 is a plate-like member that can be bent along the inner periphery of the connection target pipe 2, and the locked portion 4 b is intermittent along the inner periphery of the connection target pipe 2. The insertion portion 4a is formed between the locked portions 4b. Further, the retaining member 4 has a biting portion 4 c that is bent along the inner circumference of the connection target pipe 2 so as to be enlarged or reduced in diameter and that bites into the inner surface of the connection target pipe 2.

  FIG. 6 is an explanatory view showing a partial configuration of the retaining member 4 formed by a plate-like member. In this example, the locked portion 4b is formed by partially cutting and bending the side portion of the plate-like member. Further, the retaining member 4 forms a biting portion 4c by bending a triangular notch portion to the opposite side to the locked portion 4b.

  FIG. 7 shows a modification of the retaining member 4 formed by the plate-like member described above. According to this, as shown in FIG. 7A, the retaining member 4 is provided with a positioning bent portion 4d on the side edge. The positioning bent portion 4d can position the fixing portion of the retaining member 4 by contacting the end edge 2E of the connection target pipe 2. As shown in the figure, the retaining member 4 is disposed in the connection target pipe 2, the fastener 5 is rotated to increase the diameter of the retaining member 4, and the biting portion 4 c is bitten into the inner surface of the connection target pipe 2.

  Further, as shown in FIG. 7B, a rotation stopper 4 b 1 may be provided on the locked part 4 b of the retaining member 4. When this rotation stopper 4b1 is provided, when the locking member 3A of the joint member 3 is passed through the insertion part 4a and the joint member 3 is rotated, the locking part 3A stops when it hits the rotation stopper 4b1. The locking portion 3A can be reliably locked to the locked portion 4b.

  FIG. 8 is an explanatory view showing another example of the pipe joint structure according to the embodiment of the present invention. In the example of the pipe joint structure 1 </ b> B, the joint member 3 is a cap member that closes the end of the connection target pipe 2. According to the joint member 3 constituting such a cap member, the length L1 of the joint member 3 can be shortened, whereby the joint member 3 can be reduced in size and weight. By using such a joint member 3, the connection target pipe 2 can be closed with good workability.

  The pipe joint structure 1B according to the embodiment shown in FIG. 8 can be effectively used in replacement work for replacing an existing cast iron pipe with a PE pipe. In this case, the pipe to be connected 2 becomes a PE pipe, and this pipe joint structure 1B is used when the end of the PE pipe is closed at the end of one day of replacement work. The retaining member 4 is attached to the end of the PE pipe newly installed by replacement, and the joint member 3 is attached to close the end of the PE pipe. Since the retaining member 4 and the joint member 3 are detachable from the PE pipe, they can be reused. Thereby, the problem of waste disposal caused by cutting the fusion cap portion in the prior art can be solved.

  According to the pipe joint structure according to the embodiment of the present invention having such a feature, the mechanical joint provided on the outer peripheral surface of the connection target pipe 2 by fixing the retaining member 4 to the inner surface of the end part of the connection target pipe 2. The sealing member 31 of the portion 30 can be disposed so as to overlap the fixing position of the retaining member 4. This shortens the connection space required at the pipe end of the connection target pipe 2 as compared with the conventional joint structure in which the retaining member 4 and the sealing member 31 of the mechanical joint portion 30 are arranged side by side on the outer peripheral surface of the connection target pipe 2. can do.

  Moreover, since it is not necessary to arrange the retaining member 4 and the sealing member 31 of the mechanical joint portion 30 side by side on the outer peripheral surface of the connection target pipe 2, the joint member 3 is configured to be short along the tube axis of the connection target pipe 2. Thus, the small and lightweight joint member 3 can be obtained. Thereby, the workability of the pipe joint connection work can be improved.

  In addition, when the cap member having the structure of the joint member 3 is used to close the pipe end in the replacement work from the cast iron pipe to the PE pipe, the cap structure can be reused without generating waste during construction. Can be obtained.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention. In addition, the above-described embodiments can be combined by utilizing each other's technology as long as there is no particular contradiction or problem in the purpose and configuration.

1, 1A, 1B: pipe joint structure, 2: connection target pipe,
3: joint member, 3A: locking portion, 30: mechanical joint portion, 31: sealing member,
4: retaining member, 4a: insertion part, 4b: locked part, 4c: biting part,
5: Fastener

Claims (10)

A pipe joint structure for connecting a joint member having a mechanical joint part to an end of a connection target pipe,
A retaining member that is fixed to the inner surface of the end of the pipe to be connected is provided,
The said joint member is equipped with the latching | locking part inserted in the said connection object pipe | tube, and latches to the said retaining member, The pipe joint structure characterized by the above-mentioned. The retaining member includes an insertion portion through which the locking portion extending along the tube axis direction of the connection target pipe is inserted and a locked portion to which the locking portion is locked,
By rotating the joint member around the tube axis of the connection target pipe with the locking portion being passed through the insertion portion, the locking portion is locked to the locked portion of the retaining member. The pipe joint structure according to claim 1.   A sealing member is disposed between the inner surface of the mechanical joint portion and the outer peripheral surface of the connection target pipe, and a push ring that presses the sealing member is disposed on the outer periphery of the connection target pipe. The pipe joint structure according to claim 1 or 2, wherein the flange portion of the push ring and the flange portion of the push ring are fastened with bolts and nuts.   The retaining member is a plate-like member that can be bent along the inner periphery of the connection target tube, and the locked portion is intermittently formed along the inner periphery of the connection target tube. The pipe joint structure according to any one of claims 1 to 3, wherein a space between the stop portions is the insertion portion.   5. The pipe joint according to claim 4, wherein the retaining member has a biting portion that is curved so as to be freely expanded or contracted along an inner periphery of the connection target pipe and that bites into an inner surface of the connection target pipe. Construction.   6. The pipe joint structure according to claim 5, wherein the locked portion and the biting portion are formed by bent portions that are bent in opposite directions.   The said joint member is a cap member which obstruct | occludes the edge part of the said connection object pipe, The pipe joint structure described in any one of Claims 1-6 characterized by the above-mentioned.   The pipe joint structure according to claim 1, wherein the joint member is a connection joint member that connects an end of the connection target pipe and an end of the connection target pipe.   The pipe joint structure according to claim 8, wherein the pipe to be connected is a cast iron pipe.   The pipe joint structure according to claim 1, wherein the connection target pipe is a polyethylene pipe.

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