JPH02305622A - Tube body for lining of inner surface of existing pipe - Google Patents

Abstract

PURPOSE:To easily perform the inserting operation of cables in a pipe body by forming a large number of ridges continued in an axial direction to at least a part of the inner surface of the pipe body in a knurling state. CONSTITUTION:A lining pipe body 2 is composed of a thermoplastic resin and a large number of ridges 4 continued in an axial direction are formed to the inner surface thereof in a knurling state and a large number of ridges 5 are also formed to the outer peripheral surface thereof. The lining pipe body 2 has an outer diameter L2 almost equal to the inner diameter L1 of an existing pipe 1 and folded in a mode contracted in its cross sectional area in a heated and softened state to be inserted in the existing pipe 1 and one end of the pipe body 2 is hermetically closed and high temp. steam is sent in the pipe body 2 from the other end thereof to apply internal pressure to the pipe body 2 and the cross-sectional shape thereof is restored to closely bring the pipe body 2 into contact with the inner surface of the existing pipe 1 to complete lining. A cable 3 is drawn from one end of the lining pipe body 2 by a traction means 6 such as a wire to be arranged but, at this time, the ridges 4 on the inner peripheral surface reduces the friction resistance of the cable 3 and the pipe body 2 to facilitate laying work.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to pipe bodies for inner lining of existing pipes, and more specifically, to underground or This invention relates to a lining pipe body that is later inserted into the inner surface of an existing pipe buried within a building frame or the like and installed as a lining for the purpose of repairing the pipe.

BACKGROUND OF THE INVENTION Existing pipes as described above may suffer from cracks and damage due to corrosion over many years or external pressure from the surrounding area. And when these damages occur,
For example, in the case of underground pipes, there is a risk that underground water infiltration may cause accidents such as short circuits, electric leaks, and disconnections in internal power wiring, communication wiring, etc. However, in practice, it may be difficult to replace existing pipes of this kind, such as those buried underground in above-ground structures or within the framework of the building itself. many.

For this reason, in recent years, repair lining methods have been increasingly used to repair damage to existing pipes, in which a synthetic resin pipe is subsequently inserted inside the pipe and the inner surface is lined.

Problem to be Solved by the Invention However, in the above-mentioned repair lining method, after inserting and installing the lining pipe, when inserting cables such as power wiring, communication wiring, etc. into the pipe, the cable and the lining may be damaged. Since the frictional force caused by the sliding contact with the inner surface of the tube is large, the cable must be pulled in with a considerable traction force, and the insertion operation is often accompanied by great difficulty. This is especially true when the cable is laid over a long distance or when the pipe is bent in the middle, and the forceful pulling of the cable may cause abrasions on the pipe wall of the lining pipe, or it may be seriously damaged. Not only can tearing occur, but problems can also arise in the cable itself, such as damage to its protective covering.

In view of these problems, the present invention aims to make it possible to easily insert cables into a lining pipe inserted into an existing target pipe without causing the above-mentioned troubles. This is intended to be a technical issue to be determined.

Means for Solving the Problems In view of the above-mentioned technical problems, the present invention provides a group of protrusions on the inner surface of a lining pipe body, which reduces the frictional force of cables when they are pulled in and performs a guiding action. It is characterized by the formation of

That is, the present invention provides a lining pipe made of thermoplastic synthetic resin that is inserted into an existing pipe and installed in close contact with the inner surface of the target pipe by applying internal pressure under a heated and softened state, The object of the present invention is to provide a tube body for lining the inner surface of an existing tube, characterized in that a large number of axially continuous protrusions are formed in a knurling shape on at least a part of the inner surface of the tube body.

Embodiment In the embodiment shown in Figs. 1 to 3, (1) is an existing cable that is partially buried underground (G) by making a bend (1a) in the middle of the conduit. Pipe (2) indicates a lining pipe installed inside the existing pipe (1) for repair or the like.

The existing pipe (1) is generally a steel pipe with a diameter of about 50 to 150 layers, into which cables (3) consisting of power wiring, communication wiring, etc. are initially inserted directly. However, if it becomes damaged over the years, a lining tube (2) is later inserted and installed as a lining for repair.

The lining tube (2) is made of a hard or semi-hard thermoplastic resin such as vinyl chloride resin or polyethylene, and it is necessary to have a large number of convex stripes continuous in the axial direction at least on the inner circumferential surface. (4) is formed in a knurling shape, and preferably, a large number of convex ridges (5) that are continuous in the axial direction are also formed on the outer peripheral surface.

The convex strip (4) on the inner surface side acts as an anti-friction and guiding member for pulling in and inserting the cable (3),
The protruding stripes (5) on the outer surface function as anti-friction and guiding members for inserting and installing the lining tube (2) itself into the existing tube (1).

The lining method for lining the lining pipe (2) inside the existing pipe (1) is not particularly limited, but a suitable example thereof is as follows.

That is, the lining pipe body (2) has the inner diameter (Ll) of the existing pipe.
As shown in Fig. 3, it is folded into a state in which the cross-sectional area is reduced in a heat-softened state, and then pulled into the existing pipe (1) from one end. and insert it. This type of insertion operation is
As shown in Japanese Patent No. 3-162221, this is carried out by connecting a tow rope to one end of the lining tube (2) and pulling it into the existing tube (1) by pulling it with a winch. After the above-mentioned insertion, one end of the lining tube (2) is sealed, and high-temperature steam is introduced from the other end to apply internal pressure to the tube (2) while maintaining it in a heated and softened state. Restore the shape and replace the existing pipe (1
) to complete the lining.

The protrusions (5) on the outer peripheral surface of the lining pipe (2) reduce frictional resistance due to sliding contact with the inner surface of the existing pipe during insertion into the existing pipe (1), and also serve as a guide. This makes it easy to insert into the existing pipe (1), especially through the bent part (1a), and protects the surface of the pipe body (2) from deep scratches or tears. This is to prevent

After the above-mentioned installation of the lining tube (2), the cable (3) is drawn into the tube by being pulled by a cable (6) such as a wire or lobe from one end thereof. During this retraction, the protrusions (4) on the inner circumferential surface of the lining tube (2) reduce the frictional resistance between the cable (3) and the tube (2), which in turn reduces the traction force. In addition to making the installation work easier, the pipe body (2) and cable (
3) It is useful for preventing scratches or tears on the protective coating of the product itself.

Therefore, the protrusions (4) on the inner peripheral surface of the lining pipe (2)
The convex stripes (5) on the outer circumferential surface may be formed over the entire inner and outer circumferential surfaces of the tube body (2) as shown in FIG. A group of convex stripes (4
A) (5A) may be set as one unit, and these may be separately provided at multiple locations in the circumferential direction at equal intervals. For example, about 4 to 10 protruding strip groups (4A) (5A) may be arranged at equal intervals at four locations in the circumferential direction, and in such a manner that the inner and outer protruding strip groups do not overlap.

Note that the cross-sectional shape of the protrusions (4) and (5) is not particularly limited, but may be triangular as shown in the figure, or may be trapezoidal, semicircular, or the like. Moreover, the height is generally about 1 to 5 meters.

Effects of the Invention As described above, the present invention provides a lining made of heat-resistant plastic synthetic resin that is inserted into an existing pipe, heated and softened, and then applied with internal pressure to bring it into close contact with the inner surface of the target pipe. A pipe for use, at least a part of the inner surface of the pipe,
Since a large number of continuous protrusions in the axial direction are formed in a knurled shape, after lining the pipe body within the existing pipe, when cables, etc. are drawn and laid inside the pipe, the above protrusions are The anti-friction and guiding effects of the cable make it easy to pull in the cable. Therefore, even in the case of long pipes or pipes with bends,
By reducing the required traction force, cable installation work can be carried out easily and without any hindrance, and it also prevents harmful abrasions and splits not only on the lining tube itself but also on the protective coating of the inserted cable. prevention and enable safe cable installation.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention. Figure 1 is a sectional view showing the state after construction, Figure 2 is a sectional view of the lining tube, and Figure 3 is the state of the lining tube when it is inserted. FIG. 4 is a perspective view of a modification of the lining tube. (1)... Existing pipe, (2)... Lining pipe,
(3)...cable, (4)...convex strip. Figure 2 above

Claims (1)

[Claims] A lining pipe made of thermoplastic synthetic resin that is inserted into an existing pipe and placed in close contact with the inner surface of the target pipe by applying internal pressure under a heated and softened state. A pipe body for inner lining of an existing pipe, characterized in that at least a portion thereof is formed with a large number of continuous protrusions in the axial direction in a knurled shape.