JPH0223673Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a propulsion force transmission ring for pipe-in-pipe construction in which a new pipe is inserted into an existing pipe.

In the pipe-in-pipe construction method, a pipe joint is used in which the outside diameter of the socket is as small as possible compared to the diameter in order to prevent the capacity of the pipe from decreasing as much as possible. An example of such a pipe joint is a push-on type pipe joint, which creates a seal between the socket and the socket by compressing the sealing material attached to the annular recess on the inner periphery of the socket with the outer periphery of the socket inserted into the socket. However, it is preferable because the structure is simple and the outer diameter of the socket can be made small. by the way,
When inserting a new pipe using the pipe-in-pipe construction method, the step surface at the far end of the socket of the leading pipe is pushed by the tip of the socket of the succeeding pipe, but if the pipe becomes bent, the socket and socket are sealed with sealing material. Because it bends considerably around the position of
The contact point between the stepped surface at the back of the receptacle and the tip of the receptacle is concentrated in one point, which not only makes it impossible to reliably transmit thrust, but also causes stress concentration and the resulting distortion, which causes the mortar lining on the inner surface of the tube to peel off. There is also the problem that when the bending is excessive, the tip of the socket comes into direct contact with the mortar lining, damaging it.

In order to solve this problem, for example,
−157416 has been proposed, but in this one,
When the ring body is placed inside the cylindrical inner surface of the socket, the ring body may fall down due to its own weight, causing the bottom of the ring body to come into contact with the bottom of the cylindrical inner surface and creating an excessive gap between the tops of both. . Therefore, there still remains the problem that the propulsion force is insufficiently transmitted at the top, or that the edge of the ring body comes into contact with the mortar lining and damages it.

Therefore, the present invention aims to solve this problem by centering and holding the ring body.

In order to achieve this object, the present invention is formed in a continuous ring shape over the entire circumference, and is fitted inside the inner peripheral bottom surface portion formed in the socket portion near the stepped surface at the far end of the socket, and A ring body is provided which is sandwiched between the tip of the socket inserted into the socket and the step surface at the back end, and transmits the propulsive force from the socket to the step surface at the back end. A set bolt is provided which is screwed into each female screw hole and abuts the inner circumferential bottom surface to center and hold the ring body.

Therefore, since the ring body can be centered and held securely, it is possible to prevent the ring body from moving in the radial direction, and the propulsion force can be sufficiently transmitted, and damage to the mortar lining can be prevented. First, since the ring body is formed in a continuous annular shape over the entire circumference, if rolling, that is, deviation in the circumferential direction occurs between the socket and the socket during construction of the pipe-in-pipe method, Also, it is possible to prevent the propulsion force from being transmitted or the tip of the socket to come into direct contact with the stepped surface at the far end of the socket.

Hereinafter, embodiments of the present invention will be described based on the drawings. In Fig. 1, 1a and 1b are pipes for use in the pipe-in-pipe construction method, each having a mortar lining 2 on the inner surface, each having a socket 3 at one end and an inlet 4 at the other end. The socket 4 of the subsequent pipe 1b is inserted into the socket 3 of the pipe 1b, and the pipes are connected to each other.

The socket 3 has an annular recess 5 formed on its inner periphery near its opening end, and then a cylindrical inner surface 6 having a diameter smaller than the circumferential bottom surface of the annular recess 5 and a considerable length.
An inner circumferential bottom surface 7 having a slightly smaller diameter than this cylindrical inner surface 6 is formed, and immediately behind this inner circumferential bottom surface 7,
A rear end step surface 8 extending radially inward is formed. An annular sealing material 9 is attached to the annular recess 5 of this socket 3 . Into the socket 3 with the sealing material 9 mounted in this manner, the insertion port 4 is inserted with its outer periphery compressing the sealing material 9 in the radial direction and receiving sealing surface pressure.

The tip 10 of the socket 4 is located on the inner bottom surface 7 of the socket 3.
A ring body 11 which is sandwiched between the inner step surface 8 and the inner step surface 8 is fitted inside. As shown in FIG. 3, this ring body 11 is formed continuously into an annular shape, and has radial female threaded holes 12 bored at positions equally divided into three in the circumferential direction. The ring body 11 may be divided into one piece in the circumferential direction, and its material may be FCD40,
FCD45, SS41, etc. are suitable. Further, the number of female screw holes 12 can be selected as appropriate. A set bolt 13 is screwed into each female threaded hole 12, and when this set bolt 13 comes into contact with the inner circumferential bottom surface 7,
The ring body 11 is centered and held.

Note that FIG. 1 above shows a tube with a diameter of about 300 to 600 mm, and in the case of a large diameter tube of about 700 to 1,500 mm, the tube shown in FIG. 2 is used. That is, by using the bolt 14 and a press ring 15 into which the bolt 14 is screwed at an appropriate position in the circumferential direction, the bolt 14 is rotated and the seal material 9 is compressed by the press ring 15, thereby increasing the seal surface pressure.

Explain the promotion work. First, the ring body 11 is fitted into the inner peripheral bottom surface 7 of the socket 3, and is centered and held by the set bolts 13. Next, a sealing material 9 is attached to the annular recess 5, and the socket 4 is inserted. During this insertion, the ring material 11 is held by the set bolt 13 and will not fall due to its own weight, so there is no need for a person to enter the pipes 1a, 1b to support them. This makes it possible to improve safety.

After the insertion port 4 is inserted, the leading pipe 1a and the succeeding pipe 1b are fitted with each other in a sealed manner since the respective sockets 3 and the socket 4 are fitted with the sealing material 9 interposed therebetween, and the succeeding pipe 1b The propulsive force to be transmitted from the tip to the leading pipe 1a is transmitted from the tip 10 of the socket 4 through the ring body 11 to the step surface 8 at the far end of the socket 3. If the pipe line bends during this propulsion, or the leading pipe 1a and the trailing pipe 1b undergo an angular displacement, the insertion tip 10 will take a posture such that it hits the back end stepped surface 8 at one point in the circumferential direction. The ring body 11 between the socket tip 10 and the back end step surface 8 acts as a buffer, thereby distributing the concentrated load and relieving stress concentration at the socket tip 10 and the back end of the socket. . Furthermore, direct contact of the tip 10 of the insertion port with the mortar lining 2 is also prevented.

Furthermore, since the ring body 11 is held centered, not only during insertion but also during propulsion,
Displacement of the ring body 11 in the radial direction due to its own weight or external force can be prevented, and as a result, peeling and damage of the mortar lining 2 can be reliably prevented.

As described above, according to the present invention, since the ring body can be centered and held securely, movement of the ring body in the radial direction can be prevented, sufficient propulsion force can be transmitted, and damage to the mortar lining can be prevented. Not only that, but the ring body is formed in a continuous annular shape over the entire circumference, which prevents rolling or circumferential misalignment between the socket and the socket during construction of the pipe-in-pipe construction method. Even if this occurs, it is possible to prevent the propulsion force from being transmitted or the tip of the socket to come into direct contact with the step surface at the far end of the socket.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIGS. 1 and 2 are views showing how the ring body is installed between sockets and sockets, and FIG. 3 is a cross-sectional view of the ring body. 3...Socket, 4...Socket, 7...Inner circumference bottom, 8
...Back end stepped surface, 10...Tip, 11...Ring body, 12...Female threaded hole, 13...Set bolt.

Claims (1)

[Scope of utility model registration request] It is formed in a continuous annular shape around the entire circumference, and is fitted into the inner circumferential bottom surface portion formed in the socket portion near the stepped surface at the far end of the socket, and is connected to the tip of the socket inserted into the socket. Sandwiched between the rear end stepped surface,
A ring body is provided that transmits the propulsive force from the insertion port to the step surface at the rear end, and female threaded holes in the radial direction are bored at multiple positions in the circumferential direction of this ring body, and screwed into each female threaded hole. A propulsion force transmission ring for a pipe-in-pipe construction method, characterized in that a set bolt is provided which abuts on a circumferential bottom surface and holds the ring body centered.