JPH0155714B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is aimed at improving the sealing properties of pipe joints from inside existing pipes, such as gas pipes and water pipes, which are mainly installed underground. The present invention relates to a method for repairing a pipe joint of an existing pipe to improve its performance.

[Conventional technology]

Conventionally, the method of repairing the above-mentioned pipe joints of existing pipes from within the pipe while still in its installed state was to fill resin into the sealing material interposed between and between the joints of the pipe joints. A method of repairing the seal, and a method of repairing the seal by attaching an annular sealing member to the inner surface of the pipe at the joint to completely seal the space between the joints are known.

The latter repair method can be expected to provide a reliable repair since the inner surface of the pipe joint can be sealed with a sealing member. As shown in the figure, attach an annular elastic ring (sealing member) to the inner surface of the pipe joint via an adhesive-impregnated material, and press it against the inner surface of the pipe with a steel band from the inside. The technology is known.

[Problem to be solved by the invention]

By the way, in the case of the above-mentioned latter repair method, there is an advantage that a reliable repair can be expected, but in the conventional repair method, as seen in the above-mentioned prior art, it is not possible for a worker to enter the pipe and carry out the repair work. There was a problem in that it was applicable only to the repair of relatively large-diameter pipes, and could not be applied to the repair of medium-diameter pipes or small-diameter pipes where workers could not enter the pipes.

In view of the above-mentioned problems, the present invention provides sealing by pasting a sealing member on the inner surface of the pipe joint by thermal means or mechanical means, even in existing pipes with small diameters that do not allow workers to enter the pipes. The purpose of this invention is to provide a method for repairing a pipe joint that can be repaired.

[Means to solve the problem]

The present invention provides, as a means for achieving the above-mentioned objects, (A) a sealing member by attaching an adhesive coating to one surface of a belt-shaped sheet material having a required length, and (B) the sealing member. (C) The above-mentioned repair is carried out by supporting the above-mentioned adhesive film on the outside in a spirally wound state so that the diameter is smaller than the inner diameter of the existing pipe, and inserting the above-mentioned repair tool into the existing pipe via a repair tool that can move inside the pipe. With the sealing member aligned with the inner surface of the pipe joint to be repaired using a tool, the sealing member is unwound and expanded by thermal means or mechanical means so that it is affixed to the inner surface of the pipe with an adhesive coating. It is characterized by the fact that it can be repaired.

The above-mentioned sealing member is a double-layered sheet material with at least different coefficients of thermal expansion, and by setting the repair method on the adhesive coating side to be small, the sealing member can be expanded using heating means. can be done.

Furthermore, the sealing member is constructed such that the coating film itself is made of a material that exhibits adhesive properties when heated, so that when the sealing member is expanded by heating means, the coating film exhibits its adhesive properties at the same time. You can also.

Furthermore, when the above-mentioned sealing member is unfolded and attached, it is conceivable to configure it so that it is unfolded in a spiral shape and attached.

[Effect]

According to the present invention, the sealing member is wound into a spiral shape and inserted into the interior of the existing pipe using a repair tool, and is rewound and expanded by thermal or mechanical means to be affixed to the inner surface of the pipe. Therefore, the sealing member to be pasted inside the pipe is downsized to a diameter corresponding to the inner diameter of the existing pipe and introduced into the pipe with a repair tool, and this is then heated or mechanically heated. Since it can be easily expanded and attached, it is possible to introduce and attach it into a pipe even in a medium-sized or small-diameter pipe where an operator cannot enter the pipe.

In addition, it is possible to thermally develop and attach the sealing material that is inserted into the pipe via the repair tool while being rolled up in a spiral shape, making it much easier to apply the sealing material inside the pipe. It also becomes possible to improve performance.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In the figure, reference numeral 1 denotes a sealing member made of a belt-shaped sheet material of a required length, which includes a sheet layer 1a made of woven fabric impregnated with resin on one side and a synthetic rubber sheet with high elasticity on the other side. It is composed of two layers including layer 1b. An adhesive coating 2 is provided on the outside of the sheet layer 1a.

For example, as shown in FIG. 2, the sealing member 1 may be configured to have a spirally wound shape from the beginning, and when inserted into an existing pipe, mechanical means may be used. Therefore, it may be wound into a spiral shape as shown in the figure. Then, as shown in FIG. 3, the existing pipe A is unwound and unfolded at the pipe joint position.

When the sealing member 1 is wound into a spiral shape from the beginning, the sheet layers 1a and 1b are made of sheet materials having different coefficients of thermal expansion so that the sealing member 1 can be thermally expanded in the existing pipe A. In this case, the sheet layer 1a is composed of the other sheet layer 1.
A material having a smaller coefficient of thermal expansion than b is selected.

Sealing member 1 for the inside of the existing pipe A
Various methods can be considered for insertion. An example is shown in FIG. In this example, a large number of support ribs 4 are provided on the outer peripheral surface of a cylindrical repair tool 3 with conical ends, protruding in the axial direction of the repair tool 3 at required intervals. The spirally wound sealing member 1 is supported through the support. The repair tool 3 is provided with traction wires 5 and 6 at its front and rear ends, and has casters 5a and 6a so that when the existing pipe A is inserted into the pipe, the outside of the sealing member 1 is attached to the inner wall of the existing pipe A. Insert into the pipe in a reduced size so that the sides (adhesive coating) do not touch.

When the repair tool 3 is moved to the position of the pipe joint part B by the pulling wires 5 and 6, the existing pipe A is
When heated air is sent into the pipe, when this heated air passes around the repair tool 3, it has a thermal effect on the sealing member 1, causing the sheet layer 1b to expand more than the sheet layer 1a, thereby causing the sealing member to 1
As shown in Fig. 5, it is unfolded in the direction of unwinding and attached to the inner wall of the pipe, and the position of the pipe joint part B is changed to the sixth position.
It can be pasted to cover it from the inside as shown in the picture.

In the above embodiment, a method was used in which the sealing member 1 is rolled up in a spiral shape and inserted into the existing pipe A, and then expanded by thermal means at the position of the pipe joint B. Of course, it is also possible to adopt a method in which the tube 1 is mechanically wound and released at the pipe joint B to be attached to the inner surface of the tube.

Further, as shown in FIG. 7, the sealing member 1 is made into a long tape-like member, which is wound into a spiral shape and introduced into the pipe, and is expanded into a spiral shape at the position of the pipe joint B for sealing. Other methods are also possible. In this case as well, various methods can be considered, such as a thermal development method and a mechanical development method.

Furthermore, it is preferable that the coating film exhibits adhesiveness under the influence of heat so that it does not unduly adhere to the inner wall of the pipe when it is inserted into an existing pipe.

〔Effect of the invention〕

As explained above, the present invention involves rolling a sealing member into a spiral shape and inserting it into an existing pipe via a repair tool, and then unwinding and expanding it by thermal means or mechanical means to seal the inner surface of the pipe. Since it is a type of sealing material that can be attached to the inside of a pipe, it is possible to reduce the size of the sealing member that is pasted inside the pipe to a diameter that corresponds to the inner diameter of the existing pipe and introduce it into the pipe. Easily expand using means,
Since it can be pasted, it can be used even in medium and small diameter pipes where workers cannot enter the pipe.
The sealing member can be introduced into the pipe and pasted, and the sealing of existing pipes of various pipe diameters can be repaired so as to cover the pipe joints from the inside.

In addition, the sealing member inserted into the pipe via the repair tool in a spiral shape can be thermally expanded and attached, making it much easier to apply the sealing member inside the pipe. It is also possible to improve the workability of repairs.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a part of a sealing member according to an embodiment of the present invention, Fig. 2 is a perspective view showing the state of the sealing member before it is inserted into an existing pipe, and Fig. 3 is a sectional view of a part of the sealing member in an embodiment of the present invention. 4 is a vertical sectional view showing how the repair tool is used in sealing, FIG. 5 is an end view of the same, and FIG. FIG. 7 is a vertical side view showing the sealing method of another embodiment. DESCRIPTION OF SYMBOLS 1... Sealing member, 1a, 1b... Seal layer, 2... Paint film, 3... Repair tool, 4... Support rib, 5, 6... Traction wire.

Claims (1)

[Claims] 1. A sealing member is constructed by attaching an adhesive coating to one side of a belt-shaped sheet material having a required length, and the sealing member is attached to the inside diameter of an existing pipe with the adhesive coating outside. Support it in a spirally wound state to make it smaller in diameter and insert it into the existing pipe via a repair tool that can move inside the pipe, and use the repair tool to apply the sealing member to the inner surface of the pipe joint to be repaired. A method for repairing a pipe joint of an existing pipe, the method comprising: unwinding and expanding the sealing member by thermal means or mechanical means in such a state that the sealing member is attached to the inner surface of the pipe with an adhesive coating. . 2. The sealing member is made of a double-layered sheet material having at least different coefficients of thermal expansion, and the coefficient of thermal expansion on the adhesive coating side is set to be small, and the sealing member is expanded on the inner surface of the pipe joint portion. A method for repairing a pipe joint portion of an existing pipe according to claim 1, characterized in that the pipe joint portion of an existing pipe is expanded by heating means. 3. The above-mentioned sealing member is composed of a double-layered sheet material having at least different coefficients of thermal expansion, and the coefficient of thermal expansion of the adhesive coating side is set to be small, and the adhesiveness of the coating film is exhibited by heating. Claims 1 or 2, characterized in that the sealing member is made of a material that is made of a material such that when the sealing member is expanded by a heating means, the adhesiveness of the coating film is exhibited at the same time. Repair method for the pipe joint of the existing pipe described. 4. Any one of claims 1 to 3, characterized in that the sealing member is wound in a spiral/volute shape, unrolled and expanded in a spiral shape, and then affixed to the inner surface of the pipe joint portion. Repair method for pipe joints of existing pipes as described in section.