JPH07329181A - Tubular path - Google Patents

Abstract

PURPOSE:To obtain a tubular path consisting of a rigid sleeve and an inner tube containing a cylindrical fabric integrally embedded in the wall of a thermoplastic resin tube, arranged in the interior of the sleeve without adhering both. CONSTITUTION:Both a thermoplastic resin tube 4 and a cylindrical fabric 5 support a tensile strength collectively when an inner tube 3 expands, and the inner tube 3 expands enough to absorb the displacement of a sleeve 2 due to its breakdown. Consequently, the inner tube 3 remains unfractured, if the sleeve 2 is broken down and thus an inner flow path is secured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conduit mainly buried in the ground such as a gas conduit, a water pipe, a sewer pipe, and a laid conduit for a communication line, a power line, etc. The present invention relates to a structure of a pipe line in which a tough inner pipe made of plastic or the like is formed inside the outer pipe for the purpose of reinforcement and earthquake resistance.

[0002]

2. Description of the Related Art Heretofore, as a double-structured pipe line in which an inner pipe is formed in an outer pipe of this type, the one described in Japanese Patent Publication No. 60-32074 is known. This is one in which a reaction-curing adhesive is impregnated into a fiber lining material and cured, and this is used as an inner tube and bonded to the inner surface of a metal outer tube.

[0003]

However, in the pipeline having such a structure, when the outer pipe is destroyed by the action of a large external force due to an earthquake or the like, and the destroyed portion is opened, the inner pipe is firmly fixed to the outer pipe. Since it is glued and bound to
The inner pipe cannot follow the displacement of the outer pipe at the breakage point and may be broken.

Further, Japanese Patent Application No. 4-32 filed by the applicant earlier
In the specification of the 1295 application, an airtight tube is arranged between the outer tube and the inner tube in the conduit to prevent the inner tube and the outer tube from adhering to each other.

However, even in this case, since the inner pipe is made by impregnating the fiber lining material with the reaction-curing adhesive to cure it, the behavior of the lining material and the reaction-curing adhesive at the time of pulling is increased. Different.

That is, when the outer pipe is broken and a tensile force is applied to the inner pipe, the adhesive is first broken and collapsed to expose the lining material, and the fractured surface of the destroyed outer pipe is exposed to damage the lining material. , The strength may be reduced and it may break.

The present invention has been made in view of the above circumstances. Even when the outer pipe is broken due to an external force acting due to an earthquake or the like, the inner pipe expands following the displacement of the outer pipe. It is an object of the present invention to provide a structure of a pipeline that can secure an internal flow path.

[0008]

According to the present invention, an inner tube formed by embedding a tubular woven cloth in a wall thickness of a thermoplastic resin tube and integrating the inner tube is bonded to the inside of a rigid outer tube. It is characterized by being arranged without any.

In the present invention, the elongation at break of the inner pipe in the pipe axis direction is preferably 10% or more.

Further, it is preferable that the melting point of the fibers forming the tubular woven fabric is higher than the melting point of the resin forming the thermoplastic resin tube.

Further, as a concrete numerical value of the melting point of the fiber and the resin, the melting point of the fiber constituting the tubular woven cloth is 22.
It is suitable that the temperature is 0 ° C. or higher and the melting point of the resin forming the thermoplastic resin tube is 200 ° C. or lower.

The pipeline 1 of the present invention will be described below with reference to the drawings. FIG. 1 shows a pipeline 1 of the present invention. The pipe line 1 is composed of a rigid outer pipe 2 and an inner pipe 3 arranged inside the outer pipe 2.

As the outer tube 2, a metal tube such as steel, a ceramic tube, a concrete tube or the like is used depending on the type of the conduit.

The inner tube 3 is formed by arranging a tubular woven cloth 5 within the thickness of the thermoplastic resin tube 4 and integrating the tubular woven cloth 5 with the thermoplastic resin tube 4. The inner tube 3 is inserted into the outer tube 2 and extends along the inner surface of the outer tube 2, but the outer tube 2 and the inner tube 3 are not bonded.

As the thermoplastic resin tube 4 in the present invention, hard polyethylene, hard polyvinyl chloride or the like can be used. Further, as the tubular woven fabric 5, a woven fabric of natural or synthetic fibers is suitable.

In the pipe 1 of the present invention, it is preferable that the elongation at break of the inner pipe 3 in the pipe axial direction is 10% or more. If the elongation at break of the inner tube 3 is less than 10%, the outer tube 2
When the inner pipe 3 is broken, the displacement cannot be followed by the inner pipe 3, and the inner pipe 3 may be broken and the fluid may leak.

Further, it is preferable that the melting point of the fibers forming the tubular woven cloth 5 is higher than the melting point of the resin forming the thermoplastic resin tube 4. As a specific numerical value of the melting point, the melting point of the fibers forming the tubular woven cloth 5 is 220 ° C. or higher, and the melting point of the resin forming the thermoplastic resin tube 4 is 2.
Suitably it is below 00 ° C.

When the melting point of the fibers forming the tubular woven cloth 5 is lower than the melting point of the resin forming the thermoplastic resin tube 4, when the thermoplastic resin tube 4 is molded and integrated with the tubular woven cloth 5. However, the tubular woven fabric 5 may melt and the strength may be reduced.

As a method of manufacturing the inner tube 3, a tubular woven cloth 5 is passed through the head of an extruder, a synthetic resin is extruded from the outer surface of the tubular woven cloth 5, and the synthetic resin is extruded into a cylinder. The inner tube 3 in which the tubular woven cloth 5 is embedded in the thermoplastic resin tube 4 is formed by pushing the tubular woven cloth 5 through the mesh to the inside and covering the inner and outer surfaces of the tubular woven cloth 5 with a synthetic resin to integrate them. Can be formed.

As a method of arranging the inner tube 3 in the outer tube 2, the thermoplastic resin tube 4 in which the tubular woven cloth 5 is embedded is heated to be softened, which is flattened and further approximately U-shaped. The outer tube 2 is inserted into the outer tube 2 in a curved shape to a V shape, and a heating fluid such as pressurized steam is inserted into the inner tube 3 to inflate the outer tube 2
Along the inside of.

[0021]

EXAMPLE As an example of the inner tube 3 of the present invention, a tubular woven cloth 5 made of polyester fibers is tubularly embedded in the wall thickness of the inner tube 3 made of low density polyethylene, I made 3.

As a comparative example, a tubular woven cloth 5 made of the above polyester fiber was impregnated with an epoxy resin and cured to produce a product.

For both this example and the comparative example, tensile tests were performed on the tubular woven fabric, the resin and the composites produced. The stress-strain curve as a result of the tensile test is shown in FIGS. 2 and 3.

[0024]

In the present invention, when the outer tube 2 is destroyed and the destroyed portion is opened, the inner tube 3 is replaced by the outer tube 2.
Since it is not adhered to the inner pipe 3, the inner pipe 3 can extend over a wide range near the broken portion.

The inner pipe 3 of the present invention is a thermoplastic resin pipe 4.
And the tubular woven cloth 5 are integrated, and the thermoplastic resin pipe 4 can be stretched to some extent when a tensile force acts, so that when the tensile force acts on the inner pipe 3, the thermoplastic resin pipe 4 is The tubular woven fabric 5 and the tubular woven fabric 5 extend together and bear a tensile force.

The behavior during tension in the embodiment of the present invention will be described with reference to FIG. 2. The tubular woven fabric 5 stretches while the stress increases due to the tension, and stretches by about 25%. Further, the stress of the thermoplastic resin tube 4 increases until it expands by about 5%, but thereafter, it expands by 30% or more with almost no increase in stress due to slippage of molecules inside.

Then, the thermoplastic resin tube 4 and the tubular woven cloth 5
The inner tube 3 that is a composite of a thermoplastic resin tube 4 and a tubular woven cloth 5
Drawing a stress-strain curve with and, the elongation at break is about 22%
It shows the value of the degree.

On the other hand, in the comparative example using the reaction-curable resin as the resin component, as shown in FIG. 3, the tubular woven fabric 5 alone shows a curve almost the same as that in FIG. Although the mold resin has a sufficiently high strength at break, it has a low elongation at break and breaks at about 5%.

In the composite of the reaction-curable resin and the tubular woven cloth 5, the reaction-curable resin is destroyed at the stage of stretching up to about 3% and the stress is sharply reduced. After that, the tubular woven fabric 5 extends along the stress-strain curve of the single body, but since the fibers of the tubular woven fabric 5 decrease in strength, 1
The tubular woven fabric 5 is also broken at the stage of stretching by about 2%, and the entire composite body is broken.

When the reaction-curable resin is destroyed,
The tubular woven cloth 5 has not been destroyed yet, but since the destroyed resin is no longer airtight, the function of retaining the fluid inside is lost.

[0031]

Therefore, according to the present invention, when the inner tube 3 is extended, the thermoplastic resin tube 4 and the tubular woven cloth 5 cooperate to support the tensile force and absorb the displacement due to the breakage of the outer tube 2. Therefore, even if the outer pipe 2 is broken, the inner pipe 3 is not broken and the internal flow path can be secured.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which an inner pipe 3 of the present invention is inserted into a pipe line 2.

FIG. 2 is a graph of a stress-strain curve in an example of the present invention.

FIG. 3 is a graph of a stress-strain curve in a comparative example.

[Explanation of symbols]

 1 Pipeline 2 Outer pipe 3 Inner pipe 4 Thermoplastic resin pipe 5 Tubular woven cloth

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hitoshi Saito 1-24-24 Kaminita, Toyonaka-shi, Osaka E-604 (72) Inventor Shinichi Takebe 1-4-1 Kishibekita, Suita-shi, Osaka Dorifudo Dormitory

Claims (4)

[Claims] 1. An inner tube (3), which is formed by embedding a tubular woven cloth (5) within the thickness of a thermoplastic resin tube (4) inside a rigid outer tube (2) to integrate the tubular woven cloth (5). , A pipe line characterized by being arranged without adhering 2. The pipe line according to claim 1, wherein the elongation at break of the inner pipe (3) in the pipe axis direction is 10% or more. 3. The pipe line according to claim 1, wherein the melting point of the fiber forming the tubular woven fabric (5) is higher than the melting point of the resin forming the thermoplastic resin pipe (4). 4. The melting point of the fibers constituting the tubular woven fabric (5) is 220 ° C. or higher, and the melting point of the resin constituting the thermoplastic resin pipe (4) is 200 ° C. or lower. , Pipeline of claim 3