JPH0134779B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of lining underground pipes such as gas pipes and water pipes for repair or reinforcement, and particularly relates to a method for lining pipes buried underground, such as gas pipes and water pipes, for the purpose of repair or reinforcement. This provides a method for lining the

Generally, the method of lining underground pipelines is to apply an adhesive (usually a reaction-curing adhesive) to the inner surface of a flexible cylindrical lining material. One end of the material is fixedly supported in an annular shape, fluid pressure is applied to the rear part of the annular fixed part, and while the lining material is turned over so that the inside becomes the outside at the folded part formed there, the folded part is There is a known method in which the lining material is advanced into the pipe, and the turned-over lining material is inserted into the pipe, and at the same time, it is pressed against the inner surface of the pipe via the adhesive by the fluid pressure, and the adhesive is solidified and bonded. ing. This method has many advantages, such as not having to dig the entire length of the pipe, but only at both ends of a predetermined section, and can be completed in a short period of time, and has been attracting particular attention in recent years. It is.

However, when the pipe is lined with this method, the lining material covers the entire inner surface of the pipe, so if the pipe has a branch pipe, the branch pipe will be blocked. For example, in gas pipelines, there are almost no branches in the main high-pressure or medium-pressure pipes.
At the end of the low-pressure pipe, many supply pipes branch off to supply gas to each household. Therefore, blocking these supply pipes is inconvenient because it means stopping the gas supply to each household. After lining the pipe, it is possible to dig up and perforate the branched part, but if the branched part was dug up for each supply pipe, it would be no different from digging the entire length, and the greatest advantage of the above-mentioned lining method would be lost. I'll get lost.

Furthermore, as a method for drilling a hole in the lining material at a branch point without digging up the pipe after affixing the lining material to the pipe, for example, the method disclosed in Japanese Patent Application Laid-open No. 55-41274 is known. However, when attaching the lining material to the pipe, internal pressure is applied to the lining material, so if a large amount of adhesive is used, some of the adhesive will flow into the branch pipe, and the part near the branch point of the branch pipe will It is often clogged with several centimeters of hardened adhesive, and drilling through this thick adhesive layer is extremely difficult.

The present invention has been developed in view of the above circumstances, and is capable of perforating the lining material at the branch point of a pipe without digging up the pipe, and in which the perforation is prevented by the adhesive flowing into the branch pipe. The aim is to provide an unobstructed drilling method.

Accordingly, the present invention prevents the adhesive from flowing into the branch pipe by pasting a lining material on the pipe with the branch point of the branch pipe closed with a stopper, and then the stopper is heated to generate heat. Then, the lining material and adhesive at the branch point are melted or decomposed to form a hole, and the branch pipe and the pipe line are made to communicate with each other.

The present invention will be described below with reference to the drawings. FIG. 1 shows the steps of the present invention, in which 1 is a lined pipe line, and 2 is a branch pipe branched from the pipe line 1. Since a branch pipe usually rises above the ground midway to supply gas or tap water into a house, the joint at the rising part is removed and the tip of the branch pipe 2 is opened. Then, the plug 3 is inserted into the branch pipe 2 from the open end. This stopper 3
is as shown in FIG. 2, and has an electric heater 4 in its center.
The periphery thereof is covered with an elastic thermoplastic synthetic resin 5 such as polyurethane resin or soft polyvinyl chloride resin. Further, 6 is an electric wire for supplying electricity to the electric heater.

After inserting this stopper 3 from the tip of the branch pipe 2, the branch pipe 2 is covered with a lid 7. This lid 7 is provided with a through hole 8 for leading out the electric wire 6 and a pressure fluid inlet 9. This situation is shown in Figure 1a.

Next, when a pressurized fluid such as compressed air is fed from the pressure fluid inlet 9, the plug 3 moves inside the branch pipe 2 toward the branch point, and finally the plug 3 moves as shown in FIG. 1b.
is located at the branch point of the branch pipe in the pipe line 1. In order to correctly position the plug 3 at the branch point, measure the exact length of the branch pipe in advance using an appropriate length measuring method, and then make sure that the electric wire 6 or the cord connected to the plug 3 is pulled in. The position of the plug 3 is measured from the length of the plug 3, and when the plug 3 is correctly located at the branch point, the advance of the plug 3 is stopped by stopping the electric wire 6 or the string from entering, and the plug 3 is correctly positioned at the branch point. Bye. Alternatively, the plug 3 can be moved beyond the branching point into the pipe 1, and then the electric wire 6 or string can be pulled to slightly pull it into the branch pipe 2 again, thereby positioning the plug 3 at the branching point. You can also do it.

After closing the branch point with the stopper 3 in this way, a lining material 10 is placed on the inner surface of the pipe line 1 as shown in FIG. 1c.
Paste and line the inside. At this time, the adhesive used for the lining cannot flow into the branch pipe 2 because the branch point of the branch pipe 2 is closed. Also, some adhesive may enter between the stopper 3 and the pipe wall of the branch pipe 2, but this is not a problem.

When the lining material 10 is completely adhered to the inner surface of the conduit 1, current is passed through the electric heater 4 through the electric wire 6 to generate heat. The temperature of the electric heater 4 at this time is preferably several hundred degrees Celsius, preferably 400 to
Approximately 700℃ is appropriate. Then, the thermoplastic synthetic resin covering the electric heater 4 is melted by this heat, and the lining material 10 and adhesive at the branch point are melted or decomposed by the heat of the melted thermoplastic synthetic resin, and the branching point is melted. A hole is created in the lining material that was blocking the point. Then, the molten thermoplastic synthetic resin, the molten material and the decomposed material of the lining material and the adhesive drip into the pipe line 1 from the hole, and the electric heater 4 also falls into the pipe line 1, as shown in Fig. 1d. It is suspended by an electric wire 6 or a string. Then, a hole is completely made at the branch point, and pipe line 1 and branch pipe 2
This means that it can be distributed.

The remaining electric heater 4 can be taken out from the open end of the branch pipe 2 by pulling the electric wire 6 or string. In this method, the molten thermoplastic resin, melted or decomposed lining material, and adhesive are dripped into the pipe while still at high temperatures, and the lining material 1 on the bottom of the pipe is dropped.
Since water may burn out, it is better to heat the stopper 3 while water is present at the bottom of the pipe. This not only prevents damage to the bottom of the lining material, but also prevents dripped molten resin from sticking to the bottom and allows it to be easily washed away.
Since no unevenness occurs on the inner surface of the pipe, it also has the effect of reducing pressure loss.

The plug 3 used in the present invention is not limited to the shape shown in FIG. 2. FIG. 3 shows another example of the stopper 3, in which a flange portion 12 larger than the inner diameter of the branch pipe 2 is formed at the lower part of a cylindrical portion 11 having a diameter comparable to the inner diameter of the branch pipe 2. . When the stopper 3 is pushed into the branch pipe 2, the flange 12 is deformed as shown in FIG. 4a, and the stopper 3 is easily moved forward due to the fluid pressure, so that no fluid leaks. Then stopper 3
When the plug crosses the branch point and enters the pipe 1, the elasticity of the synthetic resin 5 causes the collar 12 to expand laterally, and when the plug 3 is drawn into the branch pipe 2 by pulling the electric wire 6 again,
As shown in FIG. 4B, the flange 12 is hooked to ensure that the stopper 3 is located at the branch point, and the flange 12 prevents the adhesive 13 from flowing into the branch pipe 2.

According to the present invention, a branch pipe in a conduit is sealed with a stopper at the branch point, and a lining material is attached to the pipe to line the pipe, and then the stopper is made to generate heat to perforate the lining material. , the lining work can be done without regard to the number and position of branch pipes in the pipeline, making the work easy, and because the branch points are filled with plugs, the adhesive used when attaching the lining material is easy. This allows the lining material to be easily perforated in an extremely short period of time without any flow into the branch pipe. Also, when drilling holes in the lining material,
Since it is not necessary to melt or decompose a large amount of adhesive, the amount of molten material or decomposed product produced by melting or decomposition is small, and damage to the lining material other than the perforated area is less likely.

Furthermore, the electric heater generates heat to melt the thermoplastic synthetic resin covering the electric heater, and the lining material is melted or decomposed by the molten thermoplastic synthetic resin and perforated, so that a clean hole that matches the inner diameter of the branch pipe is formed. Since the holes can be drilled and the molten thermoplastic synthetic resin covers the edges of the holes in the lining, the edges of the holes are protected and the lining does not peel off from the hole.

Further, according to the present invention, since the plug 3 is made by covering the outer surface of the electric heater 4 with the flexible thermoplastic synthetic resin 5, the thermoplastic synthetic resin 5 is in close contact with the inner surface of the branch pipe 2, and the plug 3 and Pressure fluid does not leak from between the branch pipe 2 and the pressure fluid can be easily pumped through the branch pipe. Furthermore, since the thermoplastic synthetic resin 5 is melted by generating heat from the electric heater 4, the adhesive and the lining material are melted or decomposed by the molten thermoplastic resin, and the hole is formed, thereby changing the inner shape of the branch pipe. In addition, the thermoplastic synthetic resin 5 is removed and only the electric heater 4 remains, which can be easily recovered from the branch pipe 2.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing the steps of the method of the present invention. FIG. 2 is a longitudinal sectional view showing an example of a stopper used in the present invention. FIG. 3 shows another example of the stopper, and FIG. 4 shows the state in which the stopper is used. 1... Pipeline, 2... Branch pipe, 3... Stopper, 4...
Electric heater, 5...Thermoplastic synthetic resin, 10...
... Lining material, 11 ... Cylindrical part, 12 ... Flange part.

Claims (1)

[Scope of Claims] 1. A stopper whose outer surface of an electric heater is covered with an elastic thermoplastic synthetic resin and whose maximum diameter is approximately equal to or slightly larger than the inner diameter of a branch pipe in the conduit, as described above. The branch pipe is inserted from the end of the branch pipe into the branch pipe, placed at the branch point of the branch pipe in the pipeline, and the branch pipe is occluded.The flexible cylindrical lining material coated with adhesive on the inner surface is turned inside out by fluid pressure and the pipe is closed. The lining material inserted into the channel and turned over is adhered to the inner surface of the pipe via the adhesive, and then the thermoplastic synthetic resin is melted by generating heat from the electric heater of the stopper, and the lining material is turned over at the branch point. 1. A method for lining a pipe line having a branch pipe, the method comprising: melting or decomposing the adhesive and lining material in the above to make a hole, and passing the branch pipe through the pipe line. 2. The method for lining a conduit having a branch pipe according to claim 1, characterized in that the electric heater is made to generate heat in a state where water is present at the bottom of the conduit.