JP2735856B2 - Inner surface lining method of pipe and lining pipe - Google Patents

Description

The present invention relates to an inner surface lining method for pipes, that is, a water pipe,
As a simple repair method for underground pipes such as gas pipes, the present invention relates to a lining method for separately lining a pipe on the inner surface thereof and a lining pipe used therefor.

Conventional technology and its problems Conventionally, as an inner lining method for repairing an existing pipe that has cracks or other damage as described above, a flexible synthetic resin tube is used as a lining material, and this is used in a pipe to be lined. A method is known in which a pressurized fluid is introduced and expanded after being inserted into a target tube via an adhesive.

However, in the case of using this method, it is necessary to apply an adhesive to the outer surface of the tube or the inner surface of the existing target tube, and this operation is not only considerably complicated, but also often causes a poor adhesion part, In addition, there is a great risk that the tube may be peeled off from the inner surface of the tube, and there is an essential and serious problem that the reliability of the lining condition is poor.

In addition, as a conventional proposal for solving such a problem, a synthetic resin pipe having a shape retaining shape having an outer diameter smaller than the inner diameter of the pipe to be lined was used as a lining pipe, and this was inserted into the target pipe. A lining method (Japanese Patent Laid-Open No. 63-162221), in which the pipe is expanded by passing a plug for expansion into the inside in a state where the pipe is heated and softened from the inner side to bring the pipe into close contact with the inner surface of the target pipe, A tube made of a synthetic resin having the same shape-retaining property but having an outer diameter corresponding to the inner diameter of the target pipe is used as the pipe body, and the cross-section is deformed so as to reduce the outer diameter. Then, a lining method has been proposed in which the pipe is heated and pressed from the inner surface side to restore the original shape, so that the pipe is brought into contact with the inner surface of the target pipe (Japanese Patent Laid-Open No. 63-63).
203316) has been proposed.

However, in the case of the method according to the preceding proposal,
There is no problem if the pipe to be lined is of a straight type having a relatively short length and no bent part. If the target pipe is long and has a bent part, the lining pipe Insertion of the body cannot be performed smoothly, making the insertion work difficult and severely impossible to construct, or if the lining pipe is forcibly pulled for insertion, the pipe will be in strong contact with the inner surface of the target pipe. The body is torn, or deeply abraded even if not torn,
As a result, there has been a problem that the lining tube is torn or cracked when the tube is expanded or restored.

The present invention has been made to further solve such a problem.

Means for Solving the Problems The present invention uses a thermoplastic synthetic resin pipe having the same shape preserving property as the above-mentioned conventional construction method as the lining pipe body. By using a buried tube, it is possible to easily insert it into the bent portion of the pipe to be lined by the pulling operation under the heat softened state without hindrance, and to expand the pipe after the above heat softening and insertion. The operation can be easily performed by introducing a high-temperature fluid into the lining pipe.

That is, the present invention comprises, as a lining pipe body to be lined with the inner surface of the target pipe, a thermoplastic resin pipe having an outer diameter smaller than the inner diameter of the target pipe, and the peripheral wall partially extends along the axial direction by one to one. Using a tubular body having a shape-preserving property in which a plurality of tensile reinforcing strips are embedded, pulling the tubular body from one end while heating and softening it by introducing a high-temperature fluid therein, and inserting the tubular body into the target pipe. Then, the pressure of the high-temperature fluid is increased to expand the pipe so that the pipe is brought into close contact with the inner surface of the target pipe, and then cooled and solidified, and the lining pipe having the above structure used in the pipe lining method. Is the gist.

The types of pipes requiring repair to which the lining method of the present invention is applied include, for example, existing fluid transfer pipes such as water and sewage pipes, city gas pipes, exhaust pipes, and storage pipes such as electric wiring, metal pipes, Examples include a fume pipe, an asbestos pipe, and a synthetic resin pipe.

The lining tube to be lined with the inner surface of the target tube by applying the method of the present invention is made of a thermoplastic resin such as polyvinyl chloride, polyethylene, or polypropylene, and has a sufficient shape-retaining property at room temperature, so-called hard tube. A synthetic resin tube is used.

The tube is usually formed by an extrusion method, and a tube whose outer diameter is reduced to about 95 to 60% of the inner diameter of the target pipe is used. If the outer diameter is more than 95% of the inner diameter of the target pipe, the insertion operation into the target pipe becomes difficult, and if the outer diameter is less than 60%, it is expanded radially after insertion into the existing target pipe. There is a risk that the wall thickness will be significantly uneven and the thinned portion will be cracked. Most preferably, the outer diameter of the tube is about 90 to 70% of the inner diameter of the target tube. The wall thickness of the tube is set to be slightly larger in advance so that the wall thickness required when the tube is finally lined on the inner surface of the target tube is secured. Usually, the required wall thickness after lining is in the range of about 1 to 10 mm.
It is appropriately determined according to the diameter, the expansion rate, and the like.

Further, the lining pipe used is one in which a tensile reinforcing strip is embedded and integrated in the peripheral wall. This makes it possible to smoothly perform the insertion operation by mainly bearing the tensile load applied at the time of insertion of the tube, and preferably further reduces the frictional resistance due to the sliding contact with the inner surface of the target tube to further increase the insertion operation. And protects the surface of the tube to prevent deep abrasions and tears.
Accordingly, as the material of the tensile strength reinforcing strip, any material having a certain degree of tensile strength, heat resistance, and flexibility can be used. Specifically, for example, polyamide, polyester, polyurethane, polypropylene, vinylon, acrylic Or the like, natural fibers such as hemp, cotton, or the like, or yarns made of inorganic fibers, narrow band-shaped woven fabrics, and the like. The tensile reinforcing strip made of these materials may be buried inside the peripheral wall of the tube, but is preferably made of an organic fiber woven cloth widely known as a packing band. It is preferable to embed it in the outer surface layer of the tubular body with one side thereof exposed to the outer surface. In addition, it is generally and preferably arranged about 4 to 10 strips at equal intervals on the outer surface of the peripheral wall of the pipe, but there is a sufficient gap between adjacent reinforcing strips, and It is necessary that free radial expansion is not impeded.
In this sense, a synthetic resin pipe covered or buried with a tensile material over the entire peripheral wall of the pipe body is excluded from the application of the present invention.

However, the tensile reinforcing strips may be disposed so as to be unevenly distributed only on a part of the peripheral wall of the pipe that slides on the inner surface of the target pipe at the time of insertion. Therefore, a plurality of tensile reinforcing strips may be provided only on the peripheral wall portion of the semicircle of the cross section, that is, only on one half.

The embedding of such a tensile reinforcing strip may be performed simultaneously with the extrusion of the tubular body, or a reinforcing strip may be separately attached to the peripheral surface immediately after the extrusion, and only a part of the reinforcing strip may be stuck in the embedded state by pressing means. It may be combined. In this case, an adhesive may be used in combination for sufficient integration.

In addition to using the tubular body with the tensile reinforcing strip embedded in it as a circular cross section, for the sake of convenience in storage or transportation, after extrusion molding, it is heated and softened again so that the cross section becomes flat. In this state, it may be wound up and used by a winding device.

In the lining operation using the lining tube, first, a high-temperature fluid such as high-temperature steam is introduced into the tube from one end thereof, whereby the tube is heated and softened from the inner surface side. Then, while maintaining this softened state, it is pulled into the target pipe by a pulling means such as a wire connected to one end, and the lining pipe is inserted over the entire length of the pipe. At this time, the tensile reinforcing strip softens and acts as a reinforcing agent for the resin pipe having a reduced tensile strength, bears a tensile load, prevents harmful elongation of the pipe, and is exposed to the outer surface. The tension reinforcing strip provided in this state abuts against the inner surface, particularly at the bent portion of the target pipe, and serves as a tension member to enable smooth insertion of the pipe body and to cause deep damage to the pipe. To prevent

Next, after the insertion is completed, one end of the tube is closed, and the pressure of the high-temperature fluid introduced from the other end is increased to expand the tube in the radial direction. Then, after the outer surface of the tube is brought into close contact with the inner surface of the target tube by this inflation operation, the fluid introduced into the inside is replaced with a low-temperature fluid, and the tube is cooled and solidified to complete the desired lining.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 to FIG. 4 show construction examples in which lining is applied to the inner surface of a target pipe (A) having bent portions (A1) and (A2) by the method of the present invention.

Here, the outer diameter (l) of the lining tube (1) is in the range of 95 to 60% with respect to the inner diameter (l1) of the target pipe (A).
2) A tube made of a thermoplastic synthetic resin having a small size, in which narrow strip-shaped tensile reinforcing strips (2) made of a plurality of synthetic fiber woven fabrics are embedded in six rows at predetermined intervals on the outer peripheral surface. It is used in the arrangement. The tube (1) is, for example, extruded into a circular cross section with a vinyl chloride resin, and immediately after this molding, a reinforcing strip (2) is pressed against the outer peripheral surface. It has a sufficient shape-retaining property at room temperature per se.

At the time of lining, first, the above-mentioned tube (1) is heated from the inner surface side by introducing a high-temperature fluid such as steam from one end thereof to a temperature slightly exceeding the softening temperature of the resin of the tube.
For example, in the case of vinyl chloride, it is heated to a temperature of about 80 to 95 ° C. Therefore, the tube (1) is softened by this heating. Therefore, while maintaining the heat-softened state, the tube (1) is lined by pulling it with a wire connected to one end thereof via a connection fitting (3) or with a rope (4) such as a rope. It is drawn into the target tube (A) to be inserted and inserted over its entire length. During this insertion process, in order to maintain the softened state of the tube (1), a connecting fitting (3) attached to one end of the tube (1) has a through hole (5), or communicates with the outside at the tube end. It is necessary to maintain the circulation of the high-temperature fluid (G) introduced from the other end as a through hole. In addition, the connecting fitting (3) grips the pipe (1) in a state including the tensile reinforcing strip (2), and directly applies the traction force of the cable (4) to the reinforcing strip (2). It is necessary to tighten. By such an operation, even if the target pipe (A) has a long length, and also has a bent portion (A1) (A2), the pipe (1) almost undergoes elongation deformation. Instead, it can be smoothly pulled into the target pipe (A) and inserted. In the tube (1), the outer surface is strongly slid on the inner surface at the bends (A1) and (A2) of the target tube (A), but the slip resistance is improved by the tensile reinforcing strip (2). As a result, the pipe (1) is relatively smoothly moved and inserted into the target pipe (A), and at the same time, the protective action of the reinforcing strip (2) prevents the outer peripheral surface from being significantly scratched. Is done.

When the insertion of the tube (1) is completed, the distal end is expanded in advance, and a plug (6) is attached to the expanded end, or one end is hermetically closed by any other method. And the high temperature fluid (G) supplied from the fluid supply mouthpiece (7) at the other end.
Pipe (1) by increasing the internal pressure
Is expanded in the radial direction, and is brought into close contact with the inner surface of the target pipe (A). The pressure applied here should be approximately 0.4 to 2.0 kg / cm ² .

Thereafter, the plug (6) is removed, and a low-temperature fluid such as cooling air is supplied from the fluid supply port (7) to cool and solidify the pipe (1) and to remove excess portions at both pipe ends. Resection to complete the desired lining.

In practice, such a lining method is often performed not only for short pipes, but also for long pipes of more than 10 m and 20 to 30 m. In a long lining tube corresponding to such a long target tube, it is often difficult to handle the lining tube in a straight tube form in terms of transportation and storage. Therefore, in such a case, the tube (1) is manufactured to have a slightly flat cross section, which is wound up by a winding device, transported to the site, and heated and softened as it is. It is desirable to insert the tube into the target tube so that the tube can be restored to its original circular shape during the inflation operation.

5 and 6 show modified examples of the lining tube.

The pipe (11) shown in FIG. 5 has a plurality of tensile reinforcing strips (2) embedded at predetermined intervals only in one half of a cross section corresponding to the semicircle. . This tube (11)
In the case where the target pipe (A) has a bent portion in only one direction, and only one side of the pipe body is strongly slid on the inner surface of the target pipe, the reinforcing strip (2) is arranged. It is necessary and sufficient. In addition, the effect of the condensed water (W) in the steam used as a high-temperature fluid for heating and expanding the pipe by using the part where the tensile strength reinforcing strip (2) exists in the upper half part when the lining is being used. From the above, when the internal pressure is increased to expand the pipe, the expansion of the upper part of the pipe is suppressed to some extent by the reinforcing strip (2), and the degree of expansion of the lower part and the upper part, which are relatively difficult to sufficiently rise in temperature, are averaged with those of the upper part. Therefore, it is also useful in that a significant uneven thickness state can be prevented from occurring.

The pipe (21) shown in FIG. 6 has a plurality of reinforcing fibers composed of a large number of organic fibers or inorganic fibers as tensile strength reinforcing strips (12) at equal intervals and at a position near the outer peripheral surface inside the peripheral wall. It is buried in the direction of the plug. The production of such a hard synthetic resin tube containing a reinforcing thread can be easily performed, for example, according to the technique disclosed in Japanese Patent Application Laid-Open No. 63-260421. In the case of the lining pipe (21), the reinforcing strip (12) regulates the extension of the pipe (21) when drawing into the target pipe (A), and enables a smooth insertion operation. Further, the presence of the reinforcing strip (12) near the outer peripheral surface is also useful in that harmful deep damage to the pipe (21) can be prevented.

Advantageous Effects of the Invention The present invention is to perform traction insertion into a target pipe in a state in which a lining pipe is heated and softened by introducing a high-temperature fluid into the lining pipe, and the pipe has a relatively free flexible property. In addition to having a tensile strength reinforcing strip embedded in itself, the tensile strength reinforcing strip receives a tensile load applied to the pipe at the time of insertion, and Harmful elongation or deformation is prevented, and smooth retraction and insertion into the target tube is enabled. In particular, even when the target pipe has a bent portion, it can be smoothly inserted along the pipe without any trouble. And, after this insertion, the pressure of the heating fluid is increased to expand the softened lining pipe, and the solidified pipe is cooled and solidified after being brought into close contact with the inner surface of the target pipe, so that the target pipe is a curved pipe or a different diameter pipe. Alternatively, even in the case where the inner surface has some irregularities or steps, the desired lining can be applied without any trouble. Further, the above-mentioned tensile reinforcing strip provided in the tubular body plays a role of protection at the time of insertion of the tubular body, and is useful in that damage such as breakage or damage to the tubular body can be prevented from occurring.

In particular, as in claims (2), (4) and (5), the tensile reinforcing strip is preferably formed in a narrow band shape made of an organic fiber woven fabric, and provided on the outer surface of the tubular body in an exposed state. Thereby, the sliding property with respect to the inner surface of the target pipe can be improved with the reinforcing strip when the pipe body is inserted, and the insertion property can be further improved. Further, as described in claim (6), by providing a plurality of tensile reinforcing strips on the outer peripheral surface of the pipe at equal intervals, the above-described various effects can be further ensured, and the penetrability into a curved pipe is further improved. Can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing a step of inserting a lining tube into a target tube having a bent portion, FIG. 2 is a perspective view of the lining tube, and FIG. 3 is inflated to bring the tube into close contact with the target tube. FIG. 4 is a schematic explanatory view of the inflation process, FIG. 4 is a cross-sectional view of a pipe line after lining work, and FIGS. 5 and 6 are a perspective view and a cross-sectional view showing a modified example of the lining pipe. (A) ... target pipe, (1) (11) (21) ... lining pipe, (2) (12) ... tensile strength reinforcing strip, (3) ... connecting bracket, (4) ... … Tow rope, (5)… through hole,
(6) ... stopper, (G) ... high temperature fluid.

Claims (6)

(57) [Claims] 1. A lining pipe to be lined with an inner surface of a target pipe is made of a thermoplastic resin pipe having an outer diameter smaller than an inner diameter of the target pipe, and one or a plurality of pipes are formed on a peripheral wall along an axial direction partially. Using a tubular body having a shape-retaining property in which the tensile strength reinforcing strip of the strip is buried, the tubular body is inserted into the target pipe by being pulled from one end while being softened by heating by introducing a high-temperature fluid into the inside, Then, the pressure of the high-temperature fluid is increased to expand the tube so that the tube is brought into close contact with the inner surface of the target tube, and then cooled and solidified. 2. The inner surface of a pipe according to claim 1, wherein the tensile reinforcing strip is formed of a narrow band made of woven organic fiber, and one side thereof is exposed to the outer peripheral surface of the tube. Lining method. 3. A lining tube which is inserted into a target tube and then expanded to be brought into close contact with the inner surface of the target tube. The lining tube is made of a thermoplastic synthetic resin tube having a shape-retaining property, and is partially formed along a peripheral wall along an axial direction. A tube for inner lining of a pipe, wherein one or more tensile reinforcing strips are embedded. 4. The inner surface lining method and lining method of a pipe according to claim 3, wherein the tensile reinforcing strip is formed of a narrow band-shaped body, and is buried in the pipe with one surface exposed to the outer peripheral surface. Tube. 5. The tube for lining the inner surface of a tube according to claim 4, wherein the tensile reinforcing strip is made of an organic fiber woven fabric. 6. A pipe for lining the inner surface of a pipe according to claim 4, wherein a plurality of the tensile reinforcing strips are buried on the outer peripheral surface of the pipe at equal intervals.