JP2003194272A - Aseismic joint for existing pipe regenerating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aseismic joint preventing drastically decreasing the diameter of a pipe, and sufficiently showing aseismic performance, when a new pipe is inserted in a dilapidated pipe. <P>SOLUTION: This aseismic joint prevents coming off by engaging a lock ring 3 stored in a socket 1 inner surface with an engaging groove 6 formed on an outer surface of an insertion port 5. The lock ring 3 stored in a lock ring storing groove 2 is composed of a plurality of divided pieces 31 forming an annular element by ranging in a circumferential direction, and an opening portion 14 connecting to the lock ring storing groove 2 and having circumferential length capable of storing the divided pieces 31 is provided on an outer peripheral surface of the receiving part 1. The divided pieces 31 are successively inserted from the opening portion 14 and moved in the circumferential direction, thereby inserting the lock ring 3 all around the joint along the lock ring storing groove 2. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earthquake-resistant joint for an existing pipe rehabilitation method. [0002] As a means of rehabilitating an old pipe, an existing pipe rehabilitation method is known in which an old pipe is used as a sheath pipe, and new pipes are sequentially inserted and laid in the pipe by a propulsion method. [0003] As a pipe joint in such a rehabilitation pipeline, for example, a lock ring is attached to an inner periphery of a receiving port, and a circumferential engaging groove having a constant axial width is formed on an outer periphery of the insertion port. There is one in which a lock ring is positioned in this engagement groove. [0004] With such a configuration, the insertion hole can be inserted to a position where the lock ring abuts on the inner wall of the engagement groove on the opening side of the receiving opening, and the lock ring engages with the inner wall on the back side of the receiving groove. The insertion opening can be pulled out of the receiving opening, the expansion and contraction of the engagement groove in the axial width range can be performed, and seismic performance can be provided. When a new pipe is inserted into an existing pipe to regenerate a pipe, it is necessary to increase the inner diameter of the new pipe as much as possible in order to prevent the existing flow rate from being reduced by the new pipe. There is a demand that the pipe wall thickness must be as thin as possible. On the other hand, in the above-mentioned seismic joint, the escape prevention force due to the engagement between the insertion projection and the lock ring needs to be more than a certain value.
mm, a separation prevention force of 2.9 DkN (0.3 Dt) or more is required. In this case, as shown in FIG. 5, when the earthquake-resistant joint 10 having a reduced thickness is used, the strength of the opening end of the receiving port 1 is insufficient, and there is a possibility that sufficient earthquake resistance cannot be obtained. That is, in the earthquake-resistant joint 10 shown in FIG. 5, for example, a lock ring housing groove 2 is formed on the inner surface of the opening end of the receiving port 1 of one of the tubes 11 in which a lining layer 11a is provided on the inner surface of a metal tube 11 such as a ductile cast iron tube. A lock ring 3 which is provided in the lock ring storage groove 2 and is a C-shaped split ring which can be opened.
Then, the insertion hole 5, which is the insertion hole 5 of the other tube 11, which has the circumferential engagement groove 6 formed on the outer surface thereof, is inserted into the engagement hole 6 having the width S in the axial direction. After the insertion hole 5 is inserted until the ring 3 corresponds, the set bolt 8 is tightened from the outer surface of the socket 1 to reduce the diameter of the lock ring 3 so that the lock ring 3 engages with the engagement groove 6 to prevent the lock ring 3 from coming off. In this earthquake-resistant joint 10, in order to allow the insertion opening 5 to be inserted in a state where the lock ring 3 is stored in the lock ring storage groove 2, the depth d of the storage groove 2 is required.
It is necessary to increase the depth of the lock ring 3 so that the diameter of the lock ring 3 can be expanded. In this case, the wall thickness t of the pipe in the lock ring storage groove 2 portion is locally thinned, and the bending strength of this portion decreases. A large bending stress is generated in this part by bending to a strong force applied from the lock ring 3 at the time of a large earthquake or the like, and the opening end of the receiving port is deformed into a trumpet shape as shown in an exaggerated dotted line in FIG. 5, for example. There is a possibility that the engagement with the lock ring 3 is reduced and the detachment prevention force is reduced. In FIG. 5, reference numeral 4 denotes a sealing rubber ring, which is disposed in the storage groove 1a on the inner surface of the receiving port 1 and is provided with
By fitting the concave portion 4a of the sealing rubber ring 4 into the projection 1b formed in the above, it is held so as not to be pushed into the receiving port 1 deep when the insertion port 5 is inserted. To solve the above problems, FIG.
The depth d of the lock ring storage groove 2 formed on the inner surface of the receiving port 1 is formed so as to be shallow so that the inner diameter r can be smaller than the outer diameter R of the insertion port when the lock ring 3 is stored, as shown in FIG. It has been considered that the thickness of the lock ring storage portion is increased to increase the strength. However, in this case, since the lock ring housing groove 2 has a small depth, the outer diameter R of the insertion hole 5 is larger than the inner diameter r of the lock ring 3 when the lock ring 3 is fitted. It becomes possible. Therefore, a through-hole 7 communicating from the outer surface of the receptacle 1 to the lock ring housing groove 2 is provided along the tangential direction of the receptacle 1 so that the insertion port 5 can be inserted without the lock ring 3. After the insertion into the socket 1, the through hole 7 is inserted from the outer surface of the socket 1.
Through which the lock ring component 3 can be inserted into the lock ring storage groove 2 facing the engagement groove 6 of the insertion opening 5,
The lock ring component 3 inserted from here is finally tightened with set bolts 8.
There has been proposed an earthquake-resistant joint for an existing pipe rehabilitation method capable of exerting a detachment prevention force of 3Dtf, D: nominal diameter. [0012] However, since the lock ring is usually made of steel, the lock ring storage groove 2 is used.
It takes a great deal of force to insert along the
A lock ring insertion device using a hydraulic device or the like is required, and there has been a problem that pipe connection work is troublesome. Accordingly, the present invention solves such a problem, and a lock ring for preventing slippage is easily accommodated in a receptacle into which an insertion port is inserted without a lock ring without using a large-scale device. It was done with the task of doing. According to the present invention, there is provided an earthquake-resistant joint for an existing pipe rehabilitation method according to the present invention, wherein an insertion hole formed at an end of one pipe is inserted into a socket formed at an end of the other pipe. A pipe for inserting and connecting a mouth, wherein a lock ring housed in a lock ring housing groove formed on the inner surface of the socket is engaged with an engagement groove formed on the outer surface of the insertion hole to prevent the ring from coming off. In the anti-seismic joint, the lock ring housed in the lock ring housing groove is constituted by a plurality of divided pieces that can form an annular body by being continuous in the circumferential direction, and the outer peripheral surface of the receiving port is An opening having a circumferential length capable of receiving the divided piece is provided to communicate with the storage groove of the lock ring, and the divided pieces are sequentially inserted from the opening and moved in the circumferential direction, whereby the lock ring storage groove is provided. Along the entire circumference It is designed so that a cling can be inserted. Therefore, according to the seismic joint for the existing pipe rehabilitation method of the present invention, even if the lock ring storage groove on the inner surface of the socket is made shallow, after the connection is made without the lock ring in the socket,
It is sufficient to insert the divided pieces of the lock ring divided into a plurality from the opening on the outer surface of the receiving port and move it in the circumferential direction,
The lock ring can be inserted after the pipe connection without using a large-scale insertion device. Next, an embodiment of an earthquake-resistant joint for an existing pipe rehabilitation method according to the present invention will be described. FIG. 1 is a side view of an earthquake-resistant joint for an existing pipe rehabilitation method according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view taken along line XX of FIG. 1, and FIG. 3 is a front view of a lock ring. 1 and 2, a tube 11 is a ductile metal tube having a lining layer 11a formed on an inner surface thereof.
One end of this tube 11 is used as an insertion port 5 and is inserted into a receiving port 1 formed at the other end of another tube 11. In addition, the same reference numerals are given to the same parts as those in the related art in the structure of the other joint parts, and the detailed description is omitted. An opening 14 is provided on the outer surface of the receiving port 1 so that the lock ring divided piece 31 can be inserted along the lock ring storage groove 2 in a posture along the circumferential direction. As shown in FIG. 1, the opening 14 is formed as an opening having a slot longer than the length of the divided piece 31 on the outer surface of the receiving port 1, and the divided piece 31 is oriented in a circumferential direction. Being able to be inserted. Further, the depth d and width of the lock ring housing groove 2 formed on the inner surface on the opening end side of the receiving port 1 are greater than those formed on the inner surface of the conventional receiving port shown in FIG. Is made shallower, and the strength of the receptacle is increased by the shallower depth. That is, when the insertion opening 5 is about to come out due to ground fluctuation during an earthquake, the lock ring 3 is engaged with the engagement groove 6 of the insertion opening 5 and the lock ring storage groove 2 is disengaged in the axial direction. When an ejection force acts, the bending strength is exerted so that the receiving end face 1c does not expand in a trumpet shape due to bending stress, for example. A screw hole 9 for a set bolt 8 is provided on the outer periphery of the receiving port along the lock ring housing groove. FIG. 3 is a front view of the lock ring 3 housed in the lock ring housing groove 2 and shows a state where the lock ring 3 is divided into a plurality in the circumferential direction. FIG. 3A shows a case where the lock ring 3 is simply divided into eight equal parts in the circumferential direction. In the case of the divided piece 31, after being inserted into the lock ring storage groove 2, the divided surfaces 32a are formed into an annular shape by abutting each other. In this case, a set bolt 8 is provided for each divided piece 31. In the case of the example shown in FIG.
The case where the joining step portion 32b is provided at the end of the equally divided piece 31 is shown. In this case, the divided pieces 31 are firmly engaged with each other. Also in this case, a set bolt 8 is provided for each divided piece 31. In the case of the example shown in FIG.
The joining step portions 32c at the ends of the equally-divided divided pieces 31 are opposite to each other, and the divided pieces 31 are firmly engaged with each other. Further, in this case, the set bolts 8 may be provided on the divided piece 31 on the holding side, so that the number of the set bolts 8 can be reduced. Further, as shown in FIG. 4, each of the divided pieces 31 may be connected by a pin 33 so as to be freely bent at the connected portion. Next, connection of the earthquake-resistant joint will be described. After the sealing rubber ring 4 is installed in the rubber ring storage groove 4a on the inner surface of the receiving port 1, a lubricating material (not shown) is provided if necessary.
Is applied, and the insertion opening 5 is inserted such that the notch 15 on the outer surface of the insertion opening corresponds to the notch 14 on the inner surface of the receiving opening. Then, the divided pieces 31 of the lock ring 3...
Is inserted into the elongated opening 14 on the outer surface of the receiving port 1 for each of the divided pieces 31 in the case of the divided piece 31 shown in FIG. 2, and then sliding in the circumferential direction along the lock ring storage groove 2 is repeated. The lock ring storage groove 2 is stored over the entire circumference. Further, in the case of the divided piece 31 having the connecting structure shown in FIG. 4, it is inserted while being bent at the opening. Then, the lock ring divided pieces 31 are fixed along the periphery of the lock ring storage groove 2 by the tightening force of the set bolt 8 which is finally tightened from the outer periphery of the receiving port 1 to prevent detachment. When there is a large change in the ground due to a large earthquake or the like, when the escape force acts on the insertion opening 5 and the rear end wall 6b of the engagement groove 6 engages with the lock ring 3, the lock ring storage groove 2 The escape force is also transmitted to the inner wall, and the receiving port 1 open end 1c
Strong force is applied to the side. However, since the thickness of the lock ring housing groove 2 is thick, the bending strength is high, and the opening of the receiving opening does not deform. In the above-described embodiment, the case where the shape of the opening 14 on the outer surface of the receiving port 1 is larger than the length of the divided piece 31 has been described. However, as shown in FIG. The opening may be as short as possible in the circumferential direction as long as it can be inserted into the hole. In this case, the opening area of the outer surface of the receiving port 1 can be reduced, so that the labor of perforation can be reduced, and the strength of the outer surface of the receiving port can be reduced. As described above, according to the seismic joint for the existing pipe rehabilitation method of the present invention, by setting the minimum thickness of the receiving port necessary for obtaining the seismic performance of the pipe joint, The inner diameter of the new pipe can be maximized, and the lock ring is inserted or inserted along the circumferential direction from the opening on the outer surface of the receiving port into the lock ring storage groove. Since the connection is made along the circumference while being revolved, the trouble of forcibly inserting a long lock ring as in the related art is completely omitted, and the pipe connection work is facilitated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of an earthquake-resistant joint for an existing pipe rehabilitation method according to an embodiment of the present invention. FIG. 2 is an enlarged sectional view taken along line XX of FIG. FIGS. 3A and 3B are front views of a lock ring of the earthquake-resistant joint according to the embodiment of the present invention, in which FIG. 7 shows a case where the joining steps are turned in opposite directions to each other. FIG. 4 is a cross-sectional view of a main part showing another configuration example of the lock ring according to the embodiment of the present invention. FIG. 5 is a fragmentary side view of a conventional example. FIG. 6 is a cutaway side view of a main part of another conventional example. DESCRIPTION OF SYMBOLS 1 Receiving port 2 Lock ring storage groove 3 Lock ring 4 Rubber ring for sealing 5 Insertion opening 6 Engagement groove having axial width 8 Set bolt 11 Pipe 14 Dividing piece opening 31 Lock ring dividing piece

Continuation of front page    (72) Inventor Akira Yamashita             2-26 Ohama-cho, Amagasaki-shi, Hyogo Pref.             Kubota Mukogawa Works F term (reference) 2D063 BA02 BA26 BA32                 3H015 FA04                 3H104 JA08 JB02 KA01 KB02 KB07

Claims (1)

Claims: 1. A pipe for inserting and connecting an insertion hole formed at an end of another pipe into a receptacle formed at an end of one pipe, wherein A lock ring housed in a lock ring housing groove formed on an inner surface of a receiving port is engaged with an engagement groove formed on the outer surface of the insertion opening to prevent the lock ring from coming off. The stored lock ring is constituted by a plurality of divided pieces that become an annular body by being continuous in the circumferential direction, and the outer peripheral surface of the receiving port receives the divided piece that communicates with the storage groove of the lock ring. An opening having a circumferential length capable of being provided is provided, and by sequentially inserting the divided pieces from the opening and moving in the circumferential direction, the lock ring can be inserted over the entire circumference along the lock ring storage groove. Existing seismic connection for existing pipe rehabilitation method .