JP2002267057A - Corrugate pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a corrugate pipe easy to ensure the desired strength and easy to bend with small bend radius. SOLUTION: A corrugate pipe wall part 1 protruded outwardly in the pipe radial direction so as to be continuously curved along the longitudinal direction of the pipe and a trapezoidal pipe wall part 2 protruded outwardly in the pipe radial direction so as to form a largest outside diameter part 3 with the outside diameter substantially constant along the longitudinal direction of the pipe are disposed adjacent to each other in the longitudinal direction of the pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a corrugated pipe.

[0002]

2. Description of the Related Art As a conventional corrugated pipe, as shown in FIG. 10, a corrugated pipe wall portion 1 protruding outward in the pipe radial direction so as to be continuously curved along the pipe longitudinal direction has a pipe length. As shown in FIG. 11, a resin corrugated pipe (hereinafter referred to as a corrugated corrugated pipe) C which is arranged at an interval in the hand direction, and a maximum outer diameter portion 3 whose outer diameter is substantially constant along the longitudinal direction of the pipe as shown in FIG. There is a resin corrugated pipe (hereinafter referred to as a trapezoidal corrugated pipe) D in which trapezoidal pipe wall portions 2 projecting outward in the pipe radial direction are formed at intervals in the longitudinal direction of the pipe so as to form a pipe. .

[0003]

The corrugated corrugated pipe C acts on the corrugated pipe wall 1 as an internal pressure, an external pressure, or a compressive or tensile force in the longitudinal direction of the pipe as an axial force along the pipe wall. Although it is easy to bend and deform, it is easy to secure the desired strength, but it is difficult to expand and contract in the tube longitudinal direction,
There is a disadvantage that it is difficult to bend with a small bending radius. In the trapezoidal corrugated pipe D, the cylindrical pipe wall part 2a forming the maximum outer diameter part 3 and the rising pipe wall part 2b adjacent to the cylindrical pipe wall part 2a are locally affected by the pipe pressure and the pipe pressure. In addition, the cylindrical tube wall portion 2a and the rising tube wall portion 2b are relatively easily displaced in the tube longitudinal direction by a compressive force or a tensile force in the longitudinal direction of the tube, so that it is easy to expand and contract in the longitudinal direction of the tube. Although there is an advantage that it is easy to bend with a small bending radius,
There is a disadvantage that it is difficult to secure a desired strength. The present invention has been made in view of the above circumstances, and has as its object to easily secure a desired strength and facilitate bending with a small bending radius.

[0004]

According to a first aspect of the present invention, there is provided a corrugated pipe having a corrugated pipe wall which protrudes outward in the pipe radial direction so as to be continuously curved along the pipe longitudinal direction. And a trapezoidal tube wall portion protruding outward in the tube radial direction so that the outer diameter forms a substantially constant maximum outer diameter portion along the longitudinal direction of the tube, and disposed adjacent to each other in the longitudinal direction of the tube. It is in the point that has been.

[Operation] Since the corrugated pipe wall and the trapezoidal pipe wall are disposed adjacent to each other in the longitudinal direction of the pipe, the drawback that the corrugated pipe wall is difficult to bend with a small bending radius is the drawback of the trapezoidal pipe wall. The disadvantage that it is easy to bend with a small bending radius and compensated for the difficulty in securing the desired strength of the trapezoidal tube wall can be compensated for by the advantage that the desired strength of the corrugated tube wall can be easily secured.

[Effect] Therefore, it is easy to secure a desired strength and bend easily with a small bending radius.

As shown in FIGS. 3 to 6, a resin corrugated pipe B is inserted into an existing pipe A having a straight pipe section A1 and a bent pipe section A2. In the pipe lining method of lining the inside, the corrugated pipe B is pushed from one end of the existing pipe A to the other end by a pushing operation or the towing wire 7 is used to move the corrugated pipe B from one end of the existing pipe A to the other end. When the corrugated pipe B is inserted into the existing pipe A by the pulling operation to pull the corrugated pipe B, the corrugated pipe B can be efficiently inserted.

In other words, when the corrugated corrugated pipe C as shown in FIG. 10 is used in the above-mentioned pipe lining method, it is difficult to expand and contract in the longitudinal direction of the pipe. Although easy to do,
There is a disadvantage that it is difficult to move along the curved tube portion A2. Further, when a trapezoidal corrugated pipe D as illustrated in FIG. 11 is used, it is easy to expand and contract in the pipe longitudinal direction.
However, there is a disadvantage that the trapezoidal corrugated pipe D itself expands and contracts in the existing pipe A due to the pushing operation or the towing operation, and is difficult to move efficiently. On the other hand, in the corrugated pipe B according to the present invention, the corrugated pipe wall 1 that is hardly expanded and contracted in the pipe longitudinal direction and the trapezoidal pipe wall 2 that is easily expanded and contracted in the pipe longitudinal direction are arranged adjacent to each other. It is easy to move along the straight pipe portion A1 by the pulling operation and also along the curved pipe portion A2, and the corrugated pipe B can be efficiently inserted into the existing pipe A.

As illustrated in FIGS. 3 to 6, a resin corrugated pipe B is inserted into an existing pipe A provided with a straight pipe section A1 and a bent pipe section A2, and the existing pipe A is connected. In the piping lining method, the existing piping A
The corrugated pipe B is pushed in from the one end to the other end so that even if the distal end side of the corrugated pipe B is caught on the pipe wall of the bent pipe section A2, the corrugated pipe can be passed through the bent pipe section A2 well. B, the corrugated pipe B is elastically compressed and deformed in the pipe axis direction by the pushing operation of the corrugated pipe B, and the tip side of the corrugated pipe B is pulled by the towing wire 7 to change the direction of the corrugated pipe B as necessary. A pressurized fluid is supplied into B, and the distal end side of the corrugated pipe B is bent by the elastic restoring force of the corrugated pipe B and the fluid pressure against the movement resistance of the corrugated pipe B in the bent pipe A2. A2
When the corrugated pipe B is passed through the curved pipe section A2 while being returned and deformed so as to conform to the shape of the above, the corrugated pipe B can be efficiently inserted along the curved pipe section A2.

That is, in the above-mentioned pipe lining method, when a trapezoidal corrugated pipe D as shown in FIG. 11 is used, it easily expands and contracts in the longitudinal direction of the pipe. Corrugated pipe D
Even if is elastically contracted and deformed by a pushing operation, its elastic restoring force is small, and the distal end side of the trapezoidal corrugated pipe D is bent against the movement resistance of the trapezoidal corrugated pipe D in the bent pipe A2. There is a disadvantage that it is difficult to return and deform along the shape. On the other hand, in the corrugated pipe B according to the present invention, the corrugated pipe wall 1 that is hardly expanded and contracted in the pipe longitudinal direction and the trapezoidal pipe wall 2 that is easily expanded and contracted in the pipe longitudinal direction are arranged adjacent to each other. The corrugated tube wall 1 can be elastically compressed and deformed by the pushing operation of the corrugated tube B to secure a large elastic restoring force, and the corrugated tube wall 1 resists the movement resistance of the corrugated tube B in the bent tube portion A2. The corrugated pipe B can be efficiently inserted along the curved pipe section A2 when passing through the curved pipe section A2 while returning and deforming the distal end side of B so as to follow the shape of the curved pipe section A2.

Note that, for easy understanding, reference numerals are written, but the present invention is not limited to the configuration shown in the attached drawings.

A feature of the invention according to claim 2 is that the corrugated tube wall and the trapezoidal tube wall are alternately arranged along the longitudinal direction of the tube.

[Operation] Since the corrugated tube wall portion and the trapezoidal tube wall portion are alternately arranged along the longitudinal direction of the tube, a portion where bending is easy at a bending radius and a portion where desired strength is easily ensured. They can be arranged substantially uniformly along the longitudinal direction of the tube.

[Effect] A desired strength can be easily secured along the longitudinal direction of the pipe, and a desired portion can be easily bent with a small bending radius. Also, in a pipe lining method in which a resin corrugated pipe is inserted into an existing pipe having a straight pipe section and a bent pipe section to line the existing pipe, the corrugated pipe is smoothly bent along the bent pipe section. It can be moved efficiently while moving.

A feature of the invention according to claim 3 is that the maximum outer diameter of the corrugated tube wall and the maximum outer diameter of the trapezoidal tube wall are substantially the same.

[Operation] When a portion where the corrugated tube wall portion and the trapezoidal tube wall portion are arranged adjacent to each other is bent, the inner peripheral side outer surface of the bent portion is formed by the corrugated tube wall portion and the trapezoidal tube wall portion. It can be bent so as to have a smooth shape with less entry and exit in the radial direction.

[Effect] In a pipe lining method for inserting a resin corrugated pipe into an existing pipe provided with a straight pipe section and a bent pipe section and lining the existing pipe,
When the corrugated pipe is moved while being bent along the curved pipe section, the corrugated pipe can be moved smoothly in a state where the inner peripheral side outer surface of the bent portion is hardly caught on the pipe wall of the bent pipe section.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, portions denoted by the same reference numerals as those of the conventional example indicate the same or corresponding portions. FIGS. 1 and 2 show an existing gas pipe of city gas, propane gas, etc. (an example of an existing pipe). Next, a resin-made cylindrical corrugated pipe (corrugated pipe) B according to the present invention used for lining the inside of the gas pipe A is shown.

The corrugated pipe B has a corrugated pipe wall portion 1 protruding outward in the pipe radial direction so as to be continuously curved along the pipe longitudinal direction, and has an outer diameter substantially along the pipe longitudinal direction. The trapezoidal tube wall portions 2 projecting outward in the tube radial direction so as to form a constant maximum outer diameter portion 3 are arranged alternately adjacent to each other along the longitudinal direction of the tube.

The trapezoidal tube wall portion 2 includes a cylindrical tube wall portion 2a forming a maximum outer diameter portion 3, and a rising tube wall portion 2b adjacent to the cylindrical tube wall portion 2a. Both the wall portion 2a and the rising pipe wall portion 2b are formed such that the cross section along the pipe longitudinal direction is substantially straight.

The maximum outer diameter of the corrugated tube wall 1 and the maximum outer diameter of the trapezoidal tube wall 2 are made substantially the same, and the minimum inner diameter of the corrugated tube wall 1 and the minimum inner diameter of the trapezoidal tube wall 2 are set. Are substantially the same inner diameter, and the corrugated pipe wall 1 and the trapezoidal pipe wall 2 which are adjacent in the pipe longitudinal direction are connected by a connecting pipe wall 5 whose inner diameter is substantially constant along the pipe longitudinal direction.

As described above, the corrugated tube wall 1 and the trapezoidal tube wall 2
Are connected by the connecting pipe wall portion 5 whose inner diameter is substantially constant along the longitudinal direction of the pipe, so that the inner peripheral side inner surface of the bent portion is bent so as to have a smooth shape with less entry and exit in the pipe radial direction. This makes it easier for the fluid in the pipe to smoothly flow along the inner surface on the inner peripheral side of the bent portion, so that the pressure loss of gas (fluid) can be reduced.

The corrugated pipe B can be formed of various synthetic resins such as polyolefin, nylon, polyethylene terephthalate, polypropylene, polybutylene, vinyl chloride and the like. In particular, the corrugated pipe B formed of nylon 12 is preferable. The corrugated pipe B made of polyethylene has excellent rigidity and strength.
It has good long-term strength characteristics, ground fluctuation followability, and joinability, and has excellent characteristics as a gas conduit.

A pipe lining method in which the corrugated pipe B is inserted into a gas pipe A provided with a straight pipe section A1 and a bent pipe section A2 having an elbow or the like, and the inside of the gas pipe A is lined. Will be described with reference to FIGS.

The corrugated pipe B having the towing jig 6 fixed therein is inserted into one end of the gas pipe A, and the corrugating pipe 7 connected to the towing jig 6 is pulled without loosening. The gas pipe A is moved by a pushing operation of pushing the pipe B toward the other end side, and as shown in FIG. When the corrugated pipe B cannot be moved on the distal end side of the corrugated pipe B by being hooked on the pipe wall of the bent pipe portion A2, the corrugated pipe B is elastically compressed and deformed by the pushing operation.

The towing jig 6 is fitted and fixed to one end of the corrugated pipe B so that one end of the corrugated pipe B can be sealed.
A substantially hemispherical guide member 8 having a diameter larger than the maximum outer diameter of the corrugated pipe B is provided so that the distal end side of the corrugated pipe B can pass smoothly.

Next, as shown in FIG.
Pressurized air (an example of a pressurized fluid) from the pipe end of the corrugated pipe B into the corrugated pipe B so that the pipe expands and returns.
Is supplied, and by the pressure of the pressurized air and the elastic restoring force of the corrugated pipe B, the corrugated pipe B is returned and deformed along the shape of the bent pipe A2 against the movement resistance of the corrugated pipe B in the bent pipe A2. Then, the front end side of the corrugated pipe B is bent into the inside of the pipe section A2.

At this time, the movement resistance of the corrugated pipe B in the bent pipe section A2 is large, and the tip side of the corrugated pipe B does not enter the bent pipe section A2 only by the pressure of the pressurized air and the elastic restoring force of the corrugated pipe B. In such a case, by pulling the corrugated pipe B with the towing wire 7, the direction of the distal end side is changed, and the corrugated pipe B is returned and deformed so as to conform to the shape of the bent pipe portion A2. Bent tube section A2
Let go.

The front end of the corrugated pipe B has a bent pipe section A.
When the tow jig 6 is caught on the pipe wall of the bent pipe portion A2 and cannot move on the distal end side of the corrugated pipe B as shown in FIG. Tube B is elastically compressed and deformed, and FIG.
As shown in FIG. 7, the corrugated pipe B is pulled by the pulling wire 7 to change the direction of the distal end of the corrugated pipe B, and the bent pipe section is formed by the pressure of the pressurized air and the elastic restoring force of the corrugated pipe B. Against the movement resistance of the corrugated tube B in A2,
It is returned and deformed so as to conform to the shape of the straight pipe portion A1, and enters the inside thereof.

The distal end of the corrugated pipe B has a bent pipe section A.
When the gas exits from 2 to the straight pipe section A1, the corrugated pipe B is moved toward the other end of the gas pipe A by a pushing operation.

At this time, the corrugated pipe B is bent at the bent pipe section A2.
While moving while bending and deforming along the pipe, the corrugated pipe wall 1 and the trapezoidal pipe wall 2 are alternately arranged along the pipe longitudinal direction, and the maximum of the corrugated pipe wall 1 and the trapezoidal pipe wall 2 Since the outer diameters are substantially the same, as shown in FIG. 7, the inner peripheral side of the bent portion has a smooth shape with little ingress and egress of the corrugated tube wall 1 and the trapezoidal tube wall 2, and is small. It can be bent at a bending radius, and can be moved smoothly in a state where the inner peripheral side outer surface of the bent portion is hardly caught by the bent pipe portion A2.

[Other Embodiments] The corrugated pipe according to the present invention, as shown in FIG.
A corrugated portion 9 in which a plurality of corrugated tube walls 1 are arranged adjacent to each other in the longitudinal direction of the tube and a trapezoidal portion 10 in which a plurality of trapezoidal tube walls 2 are arranged adjacent to each other in the longitudinal direction of the tube. May be arranged alternately next to each other. 2. Although not shown, the corrugated pipe according to the present invention includes a portion in which a plurality of corrugated pipe walls are arranged adjacent to each other in the pipe longitudinal direction, and one trapezoidal pipe wall section, which is alternately adjacent to each other along the pipe longitudinal direction. It may be arranged. 3. Although not shown, the corrugated pipe according to the present invention is configured such that a portion in which a plurality of trapezoidal pipe walls are arranged adjacent to each other in the pipe longitudinal direction and one corrugated pipe wall are alternately adjacent to each other along the pipe longitudinal direction. It may be arranged. 4. The corrugated pipe according to the present invention, as shown in FIG.
Even if the corrugated pipe wall 1 and the trapezoidal pipe wall 2 are connected by the connecting pipe wall 4 projecting inward in the pipe radial direction so as to be continuously curved along the pipe longitudinal direction. good. 5. In the corrugated pipe according to the present invention, a half-split cylindrical corrugated pipe wall having a substantially constant curvature may be arranged along the pipe longitudinal direction. 6. The corrugated pipe according to the present invention may have a trapezoidal pipe wall in which a rising pipe wall portion adjacent to the maximum outer diameter portion has a curvature along the pipe longitudinal direction. 7. The corrugated pipe according to the present invention may be formed of various metals such as stainless steel. 8. The corrugated pipe according to the present invention may be spirally continuous with the corrugated pipe wall and the trapezoidal pipe wall adjacent to each other in the pipe longitudinal direction. 9. The corrugated pipe according to the present invention may be a pipe that is inserted into an existing pipe only by a pulling operation. 10. The corrugated pipe according to the present invention is not limited to a pipe that is inserted into an existing pipe, and may be used alone for a pipe. 11. The corrugated pipe according to the present invention is not limited to a pipe through which a gas flows, and may be a pipe such as a water pipe through which a liquid flows.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional side view of a corrugated pipe.

FIG. 2 is an enlarged sectional view of a main part of a corrugated pipe.

FIG. 3 is an explanatory view of a method of inserting a corrugated pipe into an existing pipe.

FIG. 4 is an explanatory view of a method of inserting a corrugated pipe into an existing pipe.

FIG. 5 is an explanatory view of a method of inserting a corrugated pipe into an existing pipe.

FIG. 6 is an explanatory view of a method of inserting a corrugated pipe into an existing pipe.

FIG. 7 is an enlarged sectional view of a main part.

FIG. 8 is a partial cross-sectional side view showing another embodiment.

FIG. 9 is a partial cross-sectional side view showing another embodiment.

FIG. 10 is a partial cross-sectional side view of a conventional corrugated pipe.

FIG. 11 is a partial cross-sectional side view of a conventional corrugated pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Corrugated pipe wall 2 Trapezoid pipe wall 3 Maximum outer diameter part 5 Connecting pipe wall

Continuation of the front page (72) Inventor Toshimichi Kitaoka 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka F-term in Osaka Gas Co., Ltd. (reference) 3H111 AA02 BA35 CA42 CB23 DA20 DB11

Claims (3)

[Claims] 1. A corrugated pipe wall projecting outward in the pipe radial direction so as to be curved continuously along the pipe longitudinal direction;
A trapezoidal pipe wall projecting outward in the pipe radial direction so that the outer diameter forms a substantially constant maximum outer diameter section along the pipe longitudinal direction is disposed adjacent to the pipe longitudinal direction. Corrugated pipe. 2. The method according to claim 1, wherein the corrugated tube wall and the trapezoidal tube wall are
The corrugated pipe according to claim 1, wherein the corrugated pipes are alternately arranged along a longitudinal direction of the pipe. 3. The corrugated pipe according to claim 1, wherein a maximum outer diameter of the corrugated pipe wall and a maximum outer diameter of the trapezoidal pipe wall are substantially the same.