JPH05187187A - Fiber-reinforced resin composite pipe for propulsion pipe and manufacture thereof - Google Patents

Abstract

PURPOSE:To form a step section for connecting a pipe joint at a pipe end section with no grinding. CONSTITUTION:A step section 2 to be inserted with a short tubular pipe joint 8 is formed on the inner peripheral wall of a pipe end section 1, and the whole pipe wall 3 including the pipe end section 1 is formed into a three-layer structure having a resin mortar layer 5 between two fiber-reinforced resin layers 4, 6. A step section forming spacer 11 is fitted to a core die 9, three layers 4, 5, 6 are formed on them, they are cut at the center section in the axial direction of the spacer 11, then the spacer 11 is extracted to form the step section 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber-reinforced resin composite pipe (hereinafter simply referred to as a composite pipe) suitable as a propulsion pipe in a propulsion method among various construction methods for forming a conduit in the ground. The manufacturing method is related.

[0002]

2. Description of the Related Art The propulsion method is a method of forming a pipeline by pushing a standard length propulsion pipe in a horizontal direction into the ground by sequentially abutting the end faces of each other with a propulsion device installed in a vertical shaft. It is often used for construction.

As a propulsion pipe used in this propulsion method, a composite pipe is now widely used in place of the concrete pipe or cast iron pipe.

FIG. 9 shows a manufacturing process of a conventional composite pipe. First, three layers of a fiber reinforced resin layer a, a resin mortar layer b and a fiber reinforced resin layer c are sequentially formed by filament winding on a core die (not shown). (See FIG. 9 (a)). A tube having a constant wall thickness is formed over the entire length. Next, FIG.
As shown in (b) and FIG. 10 (enlarged view of part A in FIG. 9 (b)), a part of the fiber-reinforced resin layer c and the resin mortar layer b on the outer peripheral side at the pipe end is ground to connect the pipe joint. To form a step d. Subsequently, FIG. 9C and FIG.
As shown in (c) enlarged view of portion B), the fiber reinforced resin layer e is formed again on the surface of the resin mortar layer b exposed by this grinding, and the fiber reinforced resin layer c on the outer peripheral side is formed by the load applied during propulsion. The exposed portion is protected so that peeling or cracking does not occur at the boundary portion of the resin mortar layer b. And finally, FIG. 9 (d) and FIG. 12 (FIG. 9 (d)
As shown in (enlarged view of C portion), the surface of the fiber reinforced resin layer e formed on the step d is ground again to adjust the outer diameter of this portion, and the whole process is completed. The conventional composite pipe manufactured in this manner has a step portion on the outer peripheral surface of the pipe end portion.
As shown in FIG. 3, in the propulsion method, the pipe joint f is fitted to the step portion d so as to be connected to the subsequent one by a short tubular pipe joint f.

In addition to the above-mentioned composite pipes, for example, the composite pipe disclosed in Japanese Utility Model Publication No. 2-4308 is known. In this composite pipe, the pipe end where the step is formed is composed only of the fiber reinforced resin layer, and other parts have a resin mortar layer between the two fiber reinforced resin layers as in the above-mentioned composite pipe. The three-layer structure is provided.

[0006]

However, in any of the above composite pipes, a step for connecting a pipe joint is secondarily formed by grinding on the outer peripheral surface of the pipe end.
Therefore, there is a disadvantage that it takes a lot of time and cost for manufacturing.

Particularly, in the former composite pipe, since the formation of the fiber reinforced resin layer and the grinding are alternately repeated at the end of the pipe, the above-mentioned problem is further serious.

The present invention has been made in view of the above-mentioned problems of the prior art, and it is possible to form the pipe body portion and the step portion for connecting the pipe joint at one time, and in the pipe end portion which has been conventionally required. The present invention provides a fiber-reinforced resin composite pipe for a propulsion pipe without any grinding process and a method for producing the same.

[0009]

A fiber-reinforced resin composite pipe for a propulsion pipe according to the present invention is provided with a step portion into which a short tubular pipe joint is fitted, on the inner peripheral wall of the pipe end portion, and the pipe end portion is formed. The entire tube wall including the one is a three-layer structure in which a resin mortar layer is present between two fiber reinforced resin layers.

Further, in the method for producing a fiber-reinforced resin composite pipe according to the present invention, the step-forming spacer of the same size as the pipe joint is mounted on the core type which moves in the axial direction while rotating in the circumferential direction, Three layers of a fiber-reinforced resin layer, a resin mortar layer, and a fiber-reinforced resin layer are sequentially wound and laminated on a core type and cured, and then this is cut at the axial center of the spacer, and then the spacer is removed. It is a thing.

[0011]

[Function] The entire pipe wall including the pipe end has a three-layer structure in which the resin mortar layer is present between the two fiber reinforced resin layers, and the fiber reinforced resin layer on the inner peripheral side extends from the main portion of the pipe to the step portion. The strength is high at the boundary portion between the main body portion and the stepped portion because of the integral structure.

Further, since the step portion is formed on the inner peripheral wall of the pipe end portion and the pipe joint is fitted into the step portion when the pipes are connected to each other, the surface of the connecting portion between the pipes becomes smooth and the pipe is fitted to the outside. The resistance at the time of propulsion is smaller than that in the case of the conventional composite pipe (see FIG. 13) in which unevenness is generated in the connection portion due to the pipe joint.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.

In the composite pipe of the present invention, as shown in FIG. 1, a step portion 2 into which a short tubular pipe joint 8 (see FIG. 5) is fitted is formed on an inner peripheral wall of a pipe end portion 1, Pipe wall 3 including pipe end 1
The entire structure is a three-layer structure in which the resin mortar layer 5 is present between the two fiber reinforced resin layers 4 and 6.

The fiber-reinforced resin layers 4 and 6 are made of, for example, a thermosetting resin reinforced by glass fibers, as in the conventional composite pipe.

The depth of the stepped portion 2 (length along the axial direction of the pipe) is set to be slightly longer than half the length of the pipe joint 8. Further, the innermost portion 21 of the step portion 2 need not be at a right angle to the inner peripheral wall surface as shown in the drawing, but may be an inclined surface or a curved surface.

The wall thickness of the tube end portion 1 is set to a thickness that can withstand the load during propulsion according to the length and diameter of the tube. Also,
The tube end surface 7 is a smooth surface perpendicular to the outer peripheral wall surface.

Next, a method for manufacturing the composite pipe will be described with reference to FIG.
A description will be given with reference to the following.

The core die 9 used here is a type in which an endless steel belt spirally wound around the outer peripheral surface of the core moves in the axial direction, and the width of the steel belt rotates while rotating in the axial direction. Move axially by minutes.

First, a release material 10 such as cellophane or polyester film is spirally wound around the outer peripheral surface of the core die 9,
The stepped portion forming spacers 11 are sequentially mounted thereon at intervals according to the length of the composite pipe to be manufactured.

As shown in FIG. 7, the step portion forming spacer 11 is composed of a pair of split molds 11a and 11b, and is integrated into a short tubular shape by engaging the locking portions 11c and 11d with each other. It is a thing. The outer diameter of the step forming spacer 11 is equal to the inner diameter of the step 2, and the length thereof is slightly longer than the length of the pipe joint 8. Also,
Examples of the material of the step forming spacer 11 include light urethane foam, phenol resin, acrylic resin, polyethylene, polypropylene, ABS resin, or other lightweight foam, or glass other than such organic materials.
An inorganic material such as foam such as mortar is used.

The outer shape of the step-forming spacer 11 does not need to have a right peripheral edge as shown in FIG. 2. For example, as shown in FIGS. As shown, the outer peripheral edge portion may be an inclined surface or a curved surface. Rather, it is preferable to use a spacer whose outer peripheral edge portion is an inclined surface or a curved surface because it is easy to uniformly form the fiber reinforced resin layer 4 on the inner peripheral side from the core mold 9 to the spacer.

Next, as shown in FIG. 3 (a), the core mold 9 having the step forming spacer 11 mounted thereon is attached as described above.
Three layers of the fiber reinforced resin layer 4, the resin mortar layer 5, and the fiber reinforced resin layer 6 are sequentially wound and laminated. Fiber reinforced resin layers 4, 6
Is formed by spirally winding glass rovings impregnated with thermosetting resin at a pitch corresponding to the moving speed of the core die 9. Further, since the resin mortar layer 5 is always supplied in a constant amount, excess resin mortar is scraped off at the portion where the step forming spacer 11 is present so that the surface is always smooth. FIG. 3B is a partial enlarged cross-sectional view showing the stepped portion forming spacer 11 portion after the above-mentioned three layers 4, 5, 6 are formed. As shown in this figure, the fiber reinforced resin layer 6 on the inner peripheral side is uniformly formed from the core die 9 to the step portion forming spacer 11,
The spacer 11 has a three-layer structure in which the thicknesses of the resin mortar layer 5 are different and the thicknesses of the fiber-reinforced resin layers 4 and 6 on the outer peripheral side and the inner peripheral side are constant as in the other portions.

Thereafter, after passing through a curing furnace (not shown) to cure the three layers 4, 5 and 6, as shown by a vertical broken line X in FIG. Then, the spacer 11 is removed at the axially central part of FIG. It should be noted that this cutting may be performed only on the above-mentioned three layers 4, 5, and 6, or in some cases, the spacer 11 for forming the step portion. When only the three layers 4, 5 and 6 are cut, the spacer 11 for forming the step portion remains as it is and can be reused.

The composite pipe of the present invention is completed as described above.

To connect the composite pipes thus formed,
A pipe joint 8 made of synthetic resin as shown in FIG. 5 is used. The pipe joint 8 has a short tubular shape, and has saw-tooth portions 81 for preventing slipping off at both edges of the outer peripheral surface. Further, the length of the pipe joint 8 is set to be slightly shorter than twice the depth of the step portion 2 of the composite pipe, and the outer diameter (outer diameter of the sawtooth portion 81) is equal to that of the step portion 2. It is made almost equal to the inner diameter.

FIG. 6 is a cutaway sectional view showing a state in which the composite pipes are connected to each other by the pipe joint 8. The composite pipes are in contact with each other only at their pipe end faces 7, and the propulsive force is exerted through this portion. Is transmitted.

[0028]

In the composite pipe of the present invention, the entire pipe wall including the step portion has a three-layer structure in which the resin mortar layer is present between the two fiber reinforced resin layers, and therefore the pipe end portion is formed. The strength is high and there is no risk of peeling or cracking at this portion during propulsion. Therefore, it is possible to construct a pipe line without any fear in the connecting portion.

Moreover, since the step portion is formed on the inner peripheral wall of the pipe end portion and the pipe joint is fitted into the step portion when the pipes are connected to each other, the surface of the connecting portion of the pipes becomes smooth and the pipe is externally fitted. The resistance at the time of propulsion is smaller than that in the case of the conventional composite pipe in which unevenness occurs in the connection part due to the pipe joint. Therefore, workability is also excellent.

Further, in the manufacturing method of the present invention, since the step portion is formed at the pipe end portion by using the step portion forming spacer, the grinding process for forming the step portion, which has been conventionally required, is completely eliminated. Therefore, it is possible to significantly improve the productivity and reduce the cost. Moreover, the dimensional accuracy of the stepped portion is higher than that of the conventional grinding method.

[Brief description of drawings]

FIG. 1 is a broken sectional view showing an embodiment of a fiber-reinforced resin composite pipe for a propulsion pipe according to the present invention, with an intermediate portion omitted.

FIG. 2 is a process drawing showing the method for producing a fiber-reinforced resin composite pipe for a propulsion pipe according to the present invention.

FIG. 3 is a process drawing showing a method for manufacturing a fiber-reinforced resin composite pipe for a propulsion pipe according to the present invention.

FIG. 4 is a process drawing showing the method for producing a fiber-reinforced resin composite pipe for a propulsion pipe according to the present invention.

FIG. 5 is a cutaway sectional view showing an example of a pipe joint used for connecting the fiber-reinforced resin composite pipe for a propulsion pipe of the present invention.

FIG. 6 is a broken sectional view showing a connected state of the fiber-reinforced resin composite pipe for a propulsion pipe of the present invention.

FIG. 7 is an exploded front view showing an example of a step portion forming spacer used in the method for producing a fiber-reinforced resin composite pipe for a propulsion pipe according to the present invention.

FIG. 8 is a partially cutaway front view showing another example of the stepped portion forming spacer used in the method for producing a fiber-reinforced resin composite pipe for a propulsion pipe according to the present invention.

FIG. 9 is a process chart showing a conventional method for manufacturing a fiber-reinforced resin composite pipe for a propulsion pipe.

FIG. 10 is a partial enlarged view of a portion A in FIG.

FIG. 11 is an enlarged view of each part of a B part in FIG.

FIG. 12 is an enlarged view of portions of a C section in FIG.

FIG. 13 is a broken sectional view showing a connected state of a conventional fiber-reinforced resin composite pipe for a propulsion pipe.

[Explanation of symbols]

 1 Pipe End 2 Steps 3 Pipe Wall 4 Fiber Reinforced Resin Layer 5 Resin Mortar Layer 6 Fiber Reinforced Resin Layer 8 Pipe Joint 9 Core Type 11 Stepped Spacer

Claims (2)

[Claims] 1. A step portion into which a short tubular pipe joint is fitted is formed on an inner peripheral wall of a pipe end portion, and the entire pipe wall including the pipe end portion is between two fiber reinforced resin layers. A fiber-reinforced resin composite pipe for a propulsion pipe, which has a three-layer structure in which a resin mortar layer is present. 2. A core type, which rotates in the circumferential direction and moves in the axial direction, is provided with a step forming spacer slightly larger than a pipe joint, and then the fiber type reinforced resin layer, resin mortar layer, and fiber are attached to the core type. A fiber-reinforced resin composite pipe for a propulsion pipe, characterized in that three layers of a reinforced resin layer are sequentially wound and laminated and cured, and then this is cut at a central portion in the axial direction of the spacer, and then the spacer is removed. Production method.