JPS6335408B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method for coating the inner surface of a small diameter pipe including a bent portion.

Technical background of the invention and its problems Conventionally, gas leakage from pipe joints has been prevented by inserting and lining flexible hoses made of synthetic resin into pipes such as aging city gas pipes. A method of coating the inner surface of pipes has been proposed. According to this inner surface coating method, the labor and time required for repair can be reduced compared to the conventional repair method in which repairs are performed at each leaking point in the pipe. However, this inner coating method cannot be applied to pipelines that have a relatively small diameter (about 20 to 60 mm in diameter) and include bent parts consisting of elbows (or bends) in the middle, such as city gas supply light pipes. When attempting to apply this method, the flexible hose gets stuck in the bent portion of the conduit, making subsequent insertion difficult, and thus cannot be implemented at all. Therefore, in such small-diameter pipes, it is necessary to repair leakage points individually as before, which requires a great deal of labor and time. In this case, it is possible to apply the inversion lining method using fluid pressure to line the pipeline with flexible hose, but the hoses used in the inversion method are expected to be flexible and retain their shape due to the necessity of inversion. For example, unlike a main pipe, the pipe thickness is small, such as a gas supply light pipe, and there is a risk of perforation or earth pressure collapse due to corrosion. It is unsuitable for coating the inner surface of pipes.

OBJECT OF THE INVENTION The present invention has been made for the purpose of providing a method for coating the inner surface of a pipe with a flexible hose, which can be applied to a small-diameter pipe line including a bent portion.

Composition of the Invention The present invention is an internal coating method in which a lining material is inserted and lined into a small-diameter pipe including a bent portion, and the lining material is a protective material in which a protrusion is formed in a spiral shape on the outer circumferential surface. A flexible hose with a shape is used, and the flexible hose is rotated in the same direction as the spiral of the protrusion from both the starting end opening side and the terminal opening side of the small diameter pipe line. The present invention relates to a method for coating the inner surface of a small-diameter pipe including a bent portion, which is characterized by inserting a hose into the small-diameter pipe from a starting end opening toward a terminal opening.

Embodiment of the Invention An embodiment of the present invention will be described below with reference to the accompanying drawings.

The drawing shows an example of the case where the construction method of the present invention is applied to a city gas supply light pipe.This supply light pipe usually has a diameter of 25 to 60 mmφ, a pipe length of about 5 to 10 m, and an elbow in the middle of the pipe. (Or it has about 5 to 10 bent parts consisting of bends 5.

Figure 1 shows the situation before construction; 1 is the gas main;
2 is a gas supply lamp tube, a is a gas meter, b is an iron kettle, and c is a bent portion consisting of an elbow (or bend), which are schematically shown in the figure.

Figures 2 to 4 show the state of the preparation process during construction. In this preparation process, first, as shown in Figure 2, the joint 21 of the supply light pipe 2 with the main pipe 1 is excavated. Once exposed, a sealing plug 22 is applied to the proximal end of the connecting portion 21 using conventional means, and the supply of gas to the outer tube 2 is cut off. Next, both ends of the togai tube 2 are cut to form working openings 23 and 24.
A terminal connection fitting 25 is attached to the work opening 23 on the starting end side by a pipe joint 26. In the figure, 27 is a drilled hole.

Next, as shown in FIG. 3, the flexible shaft 3 is inserted through the lamp tube 2 from the starting end working port 23 side toward the terminal end working port 24 side. The tip of the shaft 3 inserted into the tube is wound up on a winding drum (not shown) of a rotary winding device 4 installed in the excavated hole 27. This device 4 is configured so that winding (pulling) and rotation (twisting) of the shaft 3 can be performed individually. Rotation can be applied by using the operation handle 41 to control the casing 42 and the casing 42. Winding is carried out by rotating a winding drum (not shown) rotatably supported within the shaft 3 in a direction that imparts twist to the shaft 3. The configuration is such that each can be performed by rotating in the winding direction. This device 4
The relationship between the casing 42 and the winding drum is substantially the same as the hose rotation and pushing device described below. As the flexible shaft 3, various shafts with spring performance that have been conventionally used for cleaning piping etc. can be used.
Flexible shafts can be advantageously used, for example those constructed from multiple layers of coiled springs.
Since the shaft 3 has flexibility,
For example, by inserting the shaft 3 while giving it a torsional rotation, it is possible to easily pass through the bent part c of the lamp tube 2. In this case, in order to easily pass through the bent part c, the tip of the shaft 3 is may be provided with suitable guide fittings.

Next, as shown in FIG. 4, the tip of the flexible hose 6 let out from the hose rotating and pushing device 5 installed on the ground is connected to the base end of the flexible shaft 3, and then the guide duct 51 of the device 5 and the light are connected. The preparatory work is completed by connecting the terminal fitting 25 on the outer tube 2 side.

Similar to the device 4 described above, the hose rotation pushing device 5 is configured so that the hose 6 can be pushed in (feeding out) and rotated (twisted) individually. By operating the handle 52 and rotating the casing 53 and, in turn, the hose winding drum 54 rotatably supported within the casing 53 in a direction that gives twist to the hose 6, the pushing is performed using a pair of upper and lower rollers installed inside the casing 53. By actively driving the feed rolls 55, 55, the structure is such that each can be performed. The outlet 531 of the casing 53 is connected to the joint pipe 5
6 to the base end of the guide duct 51. The joint pipe 56 has a hopper 57 for throwing balls.
and an adhesive supply hopper 58.

FIG. 5 shows an example of a flexible lining hose 6 used in the construction method of the present invention. The flexible hose 6 is made of rubber or plastic, and is given strength and shape retention by a spiral protrusion 61 formed on its outer circumferential surface, and this protrusion 61 also protrudes toward the inner surface. You can leave it there. The protrusion 61 has
A hard wire material 62 made of hard plastic, iron, copper, or copper alloy is used for the purpose of improving shape retention and reinforcing effect.
can be buried. The pitch of the spiral protrusions 61 formed on the outer peripheral surface of the flexible hose 6 is not particularly limited, but if the pitch is too small, the spiral feeding effect described below will be inefficient, and if it is too large, the reinforcing effect and spiral Since there is a risk of reducing the feeding effect, the width of one pitch of the spiral is preferably about 1 to 1/4, particularly about 1/2 to 1/3, of the diameter of the hose 6. The outer diameter of the flexible hose 6 (the outer diameter of the projection 61) is slightly smaller than the inner diameter of the lantern tube 2, and is usually about 1 to 3 mm (diameter) smaller.
In addition, in order to increase the strength of the flexible hose, especially the torsional rigidity in the same direction as the spiral on the outer circumferential surface, metal fibers or synthetic fibers that do not have substantially elasticity can be embedded in the membrane layer of the hose 6. .

FIG. 6 shows an example of a means for connecting the flexible shaft 3 and the hose 6. According to this connection means, there is a threaded portion 3 on the outer peripheral surface at the base end of the shaft 3.
A fixed metal fitting 31 having a fixed metal fitting 31 is fixedly installed, and this fixed metal fitting 31 is screwed into the hose 6, and this screwed joint is integrated by adhesion with an adhesive 33 and binding with a wire 34 so as not to rotate. has been done. A guide ball 35 is attached to the base end of the shaft 3 for the purpose of guiding the hose into the pipe.
The figure shows a case in which three balls 35 are provided, the diameters of which are successively made smaller from the hose 6 side. It is preferable that the maximum diameter of the ball 35 is approximately equal to the outer diameter of the hose 6 or slightly smaller than this.

During construction, in the state shown in Fig. 4, the hose 6 is inserted into the light tube 2, and from the starting end of the tube 2, the device 5 is used to apply rotation and pushing force in the same direction as the spiral, while from the terminal end. Then, insert the device 4 and the flexible shaft 3 while applying the same rotation and tensile force. In this insertion operation, the hose 6 progresses very smoothly until the distal end reaches the first bending part c, so it may be omitted to apply rotation to the hose 6.

As shown in FIG. 7, the bent part c of the lamp tube 2 is
Generally, it is composed of a screw-in type elbow (or bend) 8, and recessed step portions 81, 81 based on the elbow 8 are formed at the inlet and outlet portions thereof.

When the hose 6 is inserted up to the bent part c, the spiral groove 611 on the outer circumferential surface of its tip engages first with the recessed step 81 on the inlet side and then with the recessed step 81 on the outlet side. Therefore, the spiral groove 611 in this engaging portion exerts a screw feeding effect every time it rotates, and as it rotates, the hose 6 is fed into the lamp tube 2.

The more the hose 6 is inserted into the light tube 2, the more the frictional force between the hose 6 and the inner wall of the tube 2 increases. In this case, a sufficient torque transmission distance cannot be obtained, and the number of bends c passing through is limited to about 3 to 5. However, when the rotation imparting operation is performed from both sides as in the present invention, the transmission distance and the number of bent portions c to be passed are dramatically improved.
can be passed.

According to the present invention, it is possible to coat the inner surface of a lamp tube 2 having about 10 bent portions without any problem by inserting a flexible hose.

In the present invention, the passage through the bent portion c of the hose 6 is achieved by introducing a small diameter ball 571 into the spiral groove 611 of the hose 6 from the hopper 57 as the hose 6 is inserted, thereby exerting a ball screw effect. In addition, the adhesive 58 is also removed from the hopper 58.
1 (for example, a reaction-curing epoxy adhesive) into the spiral groove 611 to exhibit a lubricating effect, further improvement can be achieved. Moreover, this passing property can also be improved by providing the flexible shaft 3 with guide balls 35 as shown in FIG.

8 to 11 show how the end of the hose 6 inserted into the lantern tube 2 is treated.

When processing the end, a joint fitting 91 is first attached to the end of the outer lamp tube 2, as shown in FIG. In the figure, 911 is a rubber ring, 912 is a rubber ring 9
11 with the joint fitting 91. The end of the hose 6 inserted into the pipe 2 is cut to exactly match the outer end of the joint fitting 91.

Next, as shown in FIG.
1 is screwed into a threaded portion formed on its inner circumferential surface and integrated with the hose 6 by applying appropriate means such as adhesive or welding.

Next, as shown in FIG. 10, the terminal ring 92 is pushed into the joint fitting 91, and the flange portion 921 of the ring 92 is attached to the outer end of the joint fitting 91 by applying a packing 922. Terminal fitting 9 screwed into and connected to the outer end of
By sandwiching it between the concave stepped portion 931 of No. 3,
The ends of the hose 6 may be sealed. In order to improve this sealing performance, an injection port 94 is formed in the joint fitting 91 as shown in FIG.
Therefore, the gap between the hose 6 and the pipe 2 or the joint fitting 91 can be filled with the adhesive 95. If the adhesive is filled over the entire length of the hose 6, the strength of the conduit will be significantly increased.

In this way, both ends of the togai tube 2 are terminal-treated,
Then, by repairing the tube cut in the usual manner,
It is possible to restore the status quo.

Effects of the Invention In the construction method of the present invention, a flexible hose can be inserted to cover the inside of a small-diameter pipe line with a bent part in the same way as in the case of repairing a conventional gas main pipe. The measures required to repair the diameter pipe can be largely eliminated, and since the flexible hose has strength and shape retention due to the spiral protrusion, the hose can function as a pipe by itself, and the gas It has the feature that it can be applied without any problem even to pipes with a small pipe thickness and a high degree of corrosion, such as a branch pipe of a pipe (for example, the gas supply lamp outer pipe 2).

[Brief explanation of the drawing]

The drawings show a state in which the construction method of the present invention is implemented, and FIG. 1 is a longitudinal sectional view showing the situation before construction, and FIGS.
The figure is a longitudinal sectional view showing the preparation process for work in order of process, Figure 5 is a partially cutaway front view showing an example of a flexible hose used in the construction method of the present invention, and Figure 6 is a connection situation between the hose and the flexible shaft. FIG. 7 is an enlarged vertical cross-sectional view showing the state of screw feeding at the bent portion, and FIGS. 8 to 11 are vertical cross-sectional views of main parts showing the terminal processing state in process order. In the figure, 1 is the gas main pipe, 2 is the gas supply light tube, 21 is the connection part, 22 is the seal, 23, 24
1 is a working opening, 25 is a terminal connection fitting, 3 is a flexible shaft, 31 is a fixed hardware, 4 is a rotating winding device, 41 is its handle, 42 is its casing, 5 is a rotating pushing device, 51 is its guide duct, 52 53 is its handle, 53 is its casing, 54 is its hose winding drum, 55 is its feed roll, 56 is its joint pipe, 57 and 58 are its hoppers, 6 is its flexible hose, and 61 is its spiral protrusion. , 8 is the bend, 81 is the concave step, 91
92 is a joint metal fitting, 92 is a terminal ring, and 93 is a terminal metal fitting.

Claims (1)

[Claims] 1 In an internal coating method in which a lining material is inserted and lined into a small-diameter pipe including bent portions, a flexible shape-retaining material with a spiral protrusion formed on the outer circumferential surface is used as the lining material. Using a flexible hose, the flexible hose is rotated in the same direction as the spiral of the protrusion from both the starting end opening side and the terminal opening side of the small diameter pipe, and the flexible hose is connected to the small diameter pipe. A method for coating the inner surface of a small-diameter pipe including a bent part, characterized by inserting the pipe from the starting end toward the terminal opening.