JPS601178B2 - Pipe lining base material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for repairing pipes mainly buried underground, such as gas pipes, water pipes, or conduits for laying electric wires and telephone lines, as they age. This relates to lining base materials used for repairing.

Traditionally, when gas or water pipes become obsolete and gas or water leaks from the pipes, the road surface is dug up over tens to hundreds of sections to replace the old pipes with new ones. Repair methods such as replacing them were taken.

However, such repair methods require stopping the supply of gas and tap water for a long period of time, and if pipes are buried under the road, traffic on that road may be restricted. This not only caused a great deal of inconvenience, but also a great deal of manpower and expense. Furthermore, depending on the location where the pipe is buried, the above-mentioned construction methods may not be applicable at all, and a new repair method has been desired. Therefore, in recent years, it has been proposed to repair the pipe by inserting a flexible plastic tube into the pipe and gluing it to the inner surface of the pipe while the pipe remains buried.

However, even with this method, the step of inserting the tube into the conduit is extremely difficult, and especially when the tube has many bends, it is almost impossible to do so. In view of this situation, a method that has received particular attention in recent years is
A method has emerged in which the tube is inserted into the tube while being reversed so that the inner and outer surfaces are reversed using a pressure fluid such as compressed air, and at the same time this tube is bonded to the inner surface of the conduit using an adhesive. (For example, Tokuseki Sho 50-Satoshi No. 984, Tokugao Sho 53-1113019, Tokiso Sho 53-141378, etc.).

This method does not require digging the entire length of the pipe,
Because it is sufficient to simply form manholes at intervals of several hundred meters, the period during which gas and water supplies are cut off is shortened, and there is almost no hindrance to road traffic. It is an extremely excellent method, as it can line the pipes and repair even pipes with many bends. In the above-mentioned inverted insertion method, a thin, flexible plastic film is used as the base material lining the conduit.

However, because thin plastic films have low tensile strength, ``In the case of lining large-diameter pipes, the tubes may rupture due to the pressure of the fluid, or the tubes may get caught on protrusions on the inner surface of the pipe. It often breaks,
In particular, it was difficult to line long pipes. In addition to repairing aging sections of conduits, we also create strong rutted plastic pipes with hardened adhesive inside the conduits, so that even if the conduits are damaged due to vibrations, the pipes will not flow. In order to secure the pipes and prevent fluid leakage, reinforcing linings are now being applied even to pipes that have not deteriorated. cannot achieve the goal.

Therefore, as shown in JP-A No. 50-98984, the tube is reinforced with a cylindrical cloth to prevent the tube from bursting or being damaged, and the cylindrical cloth is impregnated with a large amount of adhesive. It was considered to form a strong pipe inside the pipe by adhering it to the inner surface of the pipe and reinforcing it with a cylindrical cloth, but this also caused problems.

FIG. 1 is a drawing schematically showing a state in which a lining base material 1 reinforced with a cylindrical cloth is inverted and inserted into a pend part 3 of a conduit 2.

In this drawing, broken lines 4 are lines drawn at equal intervals in the circumferential direction of the lining base material 1, and are drawn to explain the process of performing reverse insertion. As shown in FIG. 1, the lining base material 1 advances from the right side of the conduit 2 while being inverted so that the inside becomes the outside, and is crimped onto the inner surface of the conduit 2.

At this time, the broken line 4 on the lining base material 1 appears perpendicular to the length direction of the conduit 2 and is shown vertically in the drawing. Since the lining base material 1 is in the direction of moving straight, it comes into contact with the outside of the pend part 3, as shown in FIGS. However, since the lining base material 1 is reinforced with a cylindrical cloth, the above-mentioned tendency to go straight remains, and the direction of the broken line 4 remains the vertical direction, and the lining base material 1 is deformed obliquely.At this time, since the lining base material 1 hardly expands in diameter, the pressure force acting only along the outer part of the bend part 3 and against the inner part of the bend part 3 does not act, and as shown in FIG. As shown in c, a slight gap is generated. However, as the reversal progresses further, a force is generated in the lining base material 1 to try to recover the deformation, and the traveling direction of the lining base material 1 moves upward along the pipe 2. It is bent to

At this time, since the lining base material 1 is reinforced and cannot expand in the diametrical direction, a chick 5 is generated on the lining base material 1 at a position relatively above the inner portion of the bend portion 3. When the advancing direction of the lining base material 1 is bent upward while forming the lining 5 in this way, the force acting on the entire lining base material 1 will be directed upward, and the lining base material 1 will be bent at the bent portion 3. placed along the inside of the Therefore, the lining base material 1 in the portion along the outside of the bend portion 3 is drawn upward, and as shown in FIG.
A void space 6 is created between the lining base material 1 and the lining base material 1. As the reversal progresses, the void 6 gradually becomes larger (Fig. 1e), and after the tip of the reversal passes the pend portion 3, it becomes a considerably large void as shown in Fig. 1f. 6 is formed. Furthermore, after the reversal insertion is completed, when the fluid pressure inside the lining base material 1 is removed, the elongation that had occurred in the lining base material 1 in the portion in contact with the cavity 6 is removed due to the fluid pressure, and the cavity 6 contracts. In many cases, the area 6 becomes further enlarged and almost completely blocks the fluid passage within the lining base 1, making fluid circulation impossible.

Furthermore, once the void space 6 is formed as described above, since air is sealed in the void space 6, it is necessary to apply high pressure inside the lining base material 1 later to remove the void space 6. Even if the air space 6 is compressed to some extent and becomes smaller, it is impossible to remove the space 6 once created. Therefore, when inserting it in reverse, it is necessary to insert it so as not to create a void 6 from the beginning. In the above-mentioned inversion insertion method, the lining material can be inserted even if there is a bent part in the pipe,
One of its features is that it can be lined with lining, and in fact it can be lined without any problem in parts that curve with a large radius of curvature, but as mentioned above, it is difficult to line it with lining material using cylindrical cloth. Because it has poor elasticity,
If an attempt is made to line a curved portion with a small radius of curvature, such as a bend, the lining material will not be able to follow the bending, resulting in the above-mentioned problem.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a lining base material that can be used in the above-mentioned inverted insertion method to effectively repair and reinforce pipes.

Accordingly, the present invention consists of forming a flexible rubber or plastic film on the outer surface of a cylindrical cloth made of fibers woven into a cylindrical shape. In the base material for lining the inner surface of the pipe by crimping it on the inner surface of the pipe, the cylindrical cloth is pulled in the warp direction after weaving, so that the weft threads are strongly bent, and the outer diameter of the cloth is is smaller than the inner diameter of the pipe, and
When a pressure equal to the minimum fluid pressure at the time of inversion insertion is applied to the base material, its outer diameter expands by 7 to 15%, and the state of the weave corresponds to the rubber or plastic forming the film. It is characterized by being fixed by.

The structure of the lining base material 1 of the present invention will be explained below with reference to FIG. 2. 7 is a cylindrical cloth made of fibers woven into a cylindrical shape, and 8 is a flexible airtight material formed on the outer surface of the cylindrical cloth 7. It is a film of

To give an example of a more specific configuration of the lining base material 1, a cylindrical cloth 7 is used as a lining base material for a willow pipe with an inner diameter of 156 mm.
The warp threads 9 are multifilament threads of 2000 denier made of polyester synthetic fibers, and 480 warp threads are arranged in a ring.

The weft yarn 10 is a yarn made by twisting 10 Z count spun yarns of polyamide synthetic fibers, and is woven into the warp yarn 9 in a spiral manner at a rate of 7 yarns per 10 cm. This cylindrical cloth 7 is woven to have an outer diameter of 170.0 willow, and then by applying a tensile force in the length direction, the outer diameter is 148. The weft threads 10 within this cylindrical cloth 7 are contracted and are severely bent. The film 8 is made of a polyester elastic material, has a thickness of about 0.3 mm, is molded on the outer surface of the cylindrical cloth 7 by extrusion molding, and is bonded together.

The polyester elastic material constituting this film 8 enters between the weaves of the cylindrical cloth 7 during molding, and fixes the weaves of the cylindrical cloth 7 in a stretched state in its length direction. The lining material 1 has a total thickness of about 1.3 ribs and an outer diameter of 148 mm.
．． 6 ribs, flexible and airtight, 0.7
When an internal pressure of k9/ground was applied, the outer diameter expanded to the 164.6 side, and expanded by about 10.8%.

The outer diameter of the lining base material 1 when not pressurized is preferably smaller than the inner diameter of the pipe line 2, and is usually 2 to 5 mm.
Approximately 4% is appropriate. Note that the change in length of the lining base material 1 during the pressurization is small;
It was practically negligible. This seems to be due to the fact that the elongation in the length direction due to pressure is offset by the contraction in the length direction that occurs due to the expansion in the diametrical direction due to pressure, so that there is almost no apparent change in length. . When the lining base material 1 was inserted into the conduit 2 having an inner diameter of 156 ribs while being inverted with a fluid pressure of 0.7 to 1.0 k9/ground, the pendant portion 3 of the conduit 2 also had the following properties. The lining base material 1 was well adhered to the inner surface of the conduit 2, and no voids 6 as described above were formed.

The situation when the lining base material 1 of the present invention is inverted and inserted into the pend part 3 of the conduit 2 will be explained with reference to FIG. As in the case of the conventional example, the lining base material 1 of the present invention is turned over so that the inside becomes the outside as shown in FIG.
The lining base material 1 that advances from the right side of the conduit 2 and is inverted,
It is usually crimped onto the inner surface of the conduit 2.

Next, when the tip of the lining base material 1 enters the bent part 3 of the conduit 2, it is pressed against the outer part of the bent part 3 and bent upward along this, as in the case of the conventional example described above. (Figure 3 b, c). However, in the lining base material 1 of the present invention, it expands in the diametrical direction due to the fluid pressure at the time of inversion, so even when it is pressed against the outside part of the bend part 3, it does not adhere to the inside part of the bend part 3. , there are no gaps here.

In other words, if the conventional lining base material 1 is used, it will not be expanded in the diametrical direction by the fluid pressure at the time of reversal, so the length of the broken line 4 in the drawing cannot change, and the lining base material 1 will not be expanded in the outer part of the pend part 3. When the inner part of the lining base material 1 of the present invention rises up from the pipe wall surface as described above, this part does not rise up and the lining base material 1 itself slightly rises. Even though it is deformed, it can be properly adhered to the inner surface of the pipe. Furthermore, as the diameter of the lining base 1 expands, the direction of the broken line 4 in the drawing gradually becomes oblique and oblique.

As the reversal progresses further, the direction of movement of the reversed portion changes upward.

At this time, chicks 5 are formed on the lining base material 1 at the part in contact with the inner part of the pend part 3 in the same machine as the conventional example, but the extent of this rock 5 is slight compared to the case of the conventional example, and the fluid It doesn't obstruct the flow. Further, at this time, no space is created between the lining base material 1 and the conduit 2 in the outer portion of the bend portion 3, and the crimped state is maintained throughout. (Fig. 3 d, e). The reversal progresses further, and the tip of the lining base material 1 enters the upper straight pipe part, but the lining base material 1 is distorted below the straight pipe part, and the broken line 4 in the drawing is diagonal. appears.

However, this distortion is then naturally resolved over a long distance as the inversion progresses. For conventional lining base materials,
Since it does not expand in the diametrical direction due to the fluid pressure during reverse insertion, it cannot maintain a state where it is crimped to the inner surface of the pipe line even though it is distorted, and the broken line 4 in the drawing is oblique to the diametrical direction of the pipe line 2. If this happens, it will no longer be able to be adhered to the inner surface of the conduit 2, and parts of it will inevitably peel off.

On the other hand, since the lining base material of the present invention can expand in the light direction, even if the direction of the broken line 4 is oblique to the diameter direction of the pipe line 2, it will not be crimped onto the entire inner surface of the pipe line 2. It can be glued.

If the outer diameter of the lining base material 1 expands by 10%, even if the angle between the diameter direction of the pipe line 2 and the broken line 4 in the drawing becomes 25 to 30 degrees, the entire inner surface of the pipe line 2 will be properly crimped. Problems like those in the conventional example do not occur at all.Also,
Once the lining base material 1 is completely reversed and adhered to the conduit 2, it will no longer separate even when fluid pressure is removed, and a sufficient flow path can be ensured. In the present invention, the lining base material 1 only needs to be able to expand in the diameter direction by fluid pressure, and expansion and contraction in the length direction is hardly a problem.

This is because fluid pressure is always acting on the inside of the lining base material 1 at the time of proper inversion, and the inversion progresses in the lining base material 1 in an expanded/contracted state corresponding to the fluid pressure in the length direction. Therefore, since there is no other force acting to help or prevent expansion and contraction in the length direction, the state of compression to the inner surface of the pipe is not influenced by the elasticity in the length direction. The inner lining material of the present invention has a structure in which the weft threads 10 are bent sharply by applying a tensile force to the cylindrical cloth 7 in its length direction, and the cylindrical cloth 7 is contracted in the diametrical direction. It must be able to expand diametrically under appropriate fluid pressure.

Normally, the fluid pressure applied to the lining base material 1 during reverse insertion is 0.5 to 1.5 k9/m, and the pressure may fluctuate somewhat even during one reverse insertion process, but the Suitably, the lining substrate expands by about 7-15% at the minimum fluid pressure during the insertion process. If the degree of expansion is smaller than this value, the effects of the present invention cannot be fully exerted, and conversely, if it is too large,
If the strain that occurs at the bend is large and it takes an excessively long distance to be resolved in the straight pipe section, and during that time the pipe reaches the next bend, there is a risk that the pipe will not function properly at that bend. be.

In the cylindrical cloth 7 used for the lining base material 1 of the present invention, as shown in the previous example, it is preferable to use threads that are relatively easy to stretch as the weft threads 10.

In addition, it is preferable that the yarn has low elasticity and is difficult to return to its original state once it has been stretched. In addition to the spun yarn of polyamide synthetic fiber described in the previous example, examples of such yarn include B.
There is a spun-like filament yarn of polyamide synthetic fiber commonly called CF. It is also possible to use undrawn yarns or low-drawn yarns of synthetic fibers such as polyamide and polyester fibers. Further, in addition to imparting extensibility to the weft yarn 10, it is preferable that the cylindrical cloth 7 also has a structure that is easily expanded. Furthermore, by performing an extrusion molding method when molding the film 8 on the cylindrical cloth 7, the rubber or plastic forming the film 8 penetrates into the weave of the cylindrical cloth 7 in a contracted state and is fixed. Therefore, it is possible to obtain a lining base material 1 which has good dimensional stability before use and which expands in diameter to an appropriate extent when it is reversely inserted. The film 8 is not limited to the polyester elastic material described in the examples, but can be made of general rubber or plastic that is flexible and has excellent airtightness.

Further, the cylindrical cloth 7 and the membrane 8 may be bonded together to such an extent that there is no problem in the reversal insertion operation. This is because the cylindrical cloth 7 and the membrane 8 are bonded together at the same time with the adhesive used to bond the lining base material 1 and the tube 2 together.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the process of inverting and inserting a conventional lining base material into a pend part of a conduit. FIG. 2 is a perspective view of the lining base material of the present invention, and FIG. 3 is a schematic view showing the process of inverting and inserting the lining base material of the present invention into the pend part of the pipe. DESCRIPTION OF SYMBOLS 1... Lining base material, 2... Conduit, 3... Bend part, 7...
......Tubular cloth, 8...Membrane, 9...Warp, 10...Weft. Tsutomu 2, lagoon, Q, hair figure, figure c, Tsutomu figure 4, bag figure e, first figure, closing figure 4, Aoi figure, many figures C, hair figure 4, smiling figure e, figure 3 A

Claims (1)

[Claims] 1. A flexible rubber or plastic film is formed on the outer surface of a cylindrical cloth made by weaving fibers into a cylindrical shape, and this is inserted into a pipe while being inverted by fluid pressure so that the inside becomes the outside. In the base material for lining the inner surface of the pipe by being crimped onto the inner surface of the pipe, the cylindrical cloth is stretched in the warp direction after weaving, so that the weft threads are strongly bent so that the outer diameter thereof is larger than the inner diameter of the pipe. When a pressure equal to the minimum fluid pressure at the time of reverse insertion is applied to the base material, the outer diameter expands by 7 to 15%, and the state of the weave is similar to that of the film. A lining base material for a conduit, characterized in that it is fixed by rubber or plastic constituting the base material.