JPH08200558A - Structure of double piping - Google Patents

Abstract

PURPOSE: To facilitate piping work in which an inserting pipe is drawn into a sheath pipe, and also to prevent noise by a water hammer. CONSTITUTION: In the structure for a double pipe, a cylindrical inserting pipe 12 is inserted into a cylindrical sheath pipe 11 with a clearance. A tube 14 whose cross sectional outer shape is different is inserted into the clearance, the two or more line parts along in the longitudinal direction of the outer peripheral surface of the tube 14 are brought in contact with the inner peripheral surface of the sheath pipe 11, and the two or more line parts along the longitudinal direction of the inner peripheral surface are brought in contact with the outer peripheral surface of the inserting pipe 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double pipe structure which prevents noise caused by a water hammer in a sheath pipe header construction method.

[0002]

2. Description of the Related Art Conventionally, when a water supply pipe or a hot water supply pipe is installed in a building, a sheath pipe header method has been adopted. The sheath pipe header construction method means that only the sheath pipe is laid in advance on the floor wall of the building, such as the concrete floor wall, from the header of the water supply pipe or hot water supply pipe to the predetermined place such as the kitchen or washroom. It is a construction method in which the water supply pipe and the hot water supply pipe are drawn into the pipe.

In the pipe by the sheath pipe header construction method, when water or hot water in the water supply pipe or the hot water supply pipe is stopped by opening or closing the water supply pipe or the hot water supply pipe, the water supply pipe or the water supply pipe near the water supply pipe or inside the hot water supply pipe is The pressure changes abruptly, and the reaction force causes water or hot water to collide with the water tap or the inner wall of the hot water tap to vibrate, causing the water supply pipe or the hot water supply pipe to flutter and cause noise due to a water hammer.

As a method of preventing noise with a water hammer, for example, as described in JP-A-3-292487 and JP-A-4-316786, a sound deadening tape (a cushioning material) is wound around a fluid pipe to simultaneously form a sheath pipe. A method has been proposed in which the fluid pipe is prevented from fluttering in the sheath pipe by passing through the pipe.

[0005] As another method, the actual Kaihei 2-8719
As described in Japanese Patent Publication No. 5, there is proposed a striking noise generation preventing structure for a liquid-sending pipe in which a shock-damping-preventing cushioning material is provided between a sheath pipe and a liquid-sending pipe inserted therein.

Further, as another method, Japanese Patent Laid-Open No. 6-221
As described in Japanese Patent No. 490, it is formed of a flexible liquid feed pipe inserted into the sheath pipe and at least one flexible tubular or rod-shaped cushioning member inserted into the sheath pipe. A striking noise preventing structure for a sheath pipe liquid feeding pipe has been proposed.

[0007]

However, in the method using the sound deadening tape described in JP-A-3-292487 and JP-A-4-316786, since the thickness of the sound deadening tape is large, the sound deadening tape is used as a fluid pipe. It is difficult to perform the work of winding it around the sheath tube and inserting it in the sheath tube, and the workability is poor. There is a problem that it cannot be pasted.

Further, in the method using the shock-preventing shock-absorbing material disclosed in Japanese Utility Model Laid-Open No. 2-87195, when the shock-preventing shock-absorbing shock-absorbing material has a small inner diameter, the work of inserting the liquid supply pipe is difficult and the workability is poor. However, when the inner diameter of the impact preventing cushioning material is large, the impact noise preventing effect is reduced, and it is difficult to obtain an appropriate inner diameter.

Further, in the method using a flexible tubular or rod-shaped cushioning material described in JP-A-6-221490, when the amount of the cushioning material is large, it is difficult to insert the liquid feed pipe. If the workability is poor and the amount of cushioning material is small,
There is a problem that the effect of preventing impact sound is reduced and it is difficult to obtain an appropriate amount.

The present invention solves the above-mentioned problems of the prior art, and provides a structure of a double pipe in which the work of pulling the insertion pipe into the sheath pipe for piping is easy and the noise due to the water hammer is prevented. It was made for the purpose.

[0011]

DISCLOSURE OF THE INVENTION According to the present invention, in a double pipe in which a cylindrical insertion tube is inserted with a gap in a cylindrical sheath tube, a tube having an irregular cross-sectional outer shape is inserted into the gap. The outer peripheral surface of the tube is abutted on two or more rows along the longitudinal direction of the outer peripheral surface of the tube, and the inner peripheral surface of the sheath tube is contacted with two or more rows on the outer peripheral surface of the insertion tube. This is the structure of the double pipes in contact.

In the present invention, examples of the material of the tube include soft polyvinyl chloride and polyethylene. The wall thickness of the tube is preferably 0.5 mm or more because it plays a role as a cushioning material, and is preferably 3 mm or less in terms of workability when the tube is inserted into the sheath tube.

The shape of the tube is required to have an irregular outer shape in cross section, and examples thereof include an elliptical shape, a triangular shape, a quadrangular shape, a rhombic shape, and other polygonal shapes.
For example, when a tube having an elliptical cross-section is used as the tube, two rows of portions along the longitudinal direction on the major axis side of the outer peripheral surface of the tube are brought into contact with the inner peripheral surface of the sheath tube to form an inner peripheral surface. A double pipe structure is formed in which two rows of portions along the longitudinal direction on the minor axis side of the surface are in contact with the outer peripheral surface of the insertion tube.

As a method of forming the shape of the tube so that the outer shape of the cross section is irregular, for example, the inner diameter is considerably larger than the outer diameter of the insertion tube, and the outer diameter is smaller than the inner diameter of the sheath tube. Insert the insertion tube into the tube, flatten the tube, contact two or more rows along the longitudinal direction of the inner peripheral surface of the tube with the outer peripheral surface of the insertion tube, and heat to weld the contact portion. Or along the longitudinal direction of the inner surface of the tube 2
A portion of the row or more is brought into contact with the outer peripheral surface of the insertion tube and heated by a heating means such as a heat roller to weld the contact portion, or in the production line of the insertion tube, in the crosshead die,
Examples include a method in which two or more rows of the tube along the longitudinal direction of the inner peripheral surface thereof are fusion-bonded to the outer peripheral surface of the insertion tube and are simultaneously molded so that the cross-sectional outer shape becomes different.

The tube thus obtained, in which two or more rows along the longitudinal direction of the inner peripheral surface of the tube are in contact with the outer peripheral surface of the insertion tube, is inserted into the sheath tube in the longitudinal direction of the outer peripheral surface of the tube. The structure of the double pipe of the present invention can be obtained by drawing two or more rows along the inner pipe so as to contact the inner peripheral surface of the sheath pipe.

[0016]

The structure of the double pipe of the present invention is a double pipe in which a cylindrical insertion pipe is inserted with a gap in a cylindrical sheath pipe, and a tube having a cross-sectional outer shape is inserted in the gap. The outer peripheral surface of the tube is abutted on two or more rows along the longitudinal direction of the outer peripheral surface of the tube, and the inner peripheral surface of the sheath tube is contacted with two or more rows on the outer peripheral surface of the insertion tube. By being in contact with each other, it is easy to pull the insertion tube into the sheath tube through the tube to perform piping, and the tube serves as a cushioning material so that the insertion tube does not flutter in the sheath tube and the Excellent noise prevention by hammer.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view showing an example of the structure of the double pipe of the present invention. Reference numeral 1 denotes a double pipe, in which a cylindrical insertion pipe 12 is inserted into a cylindrical sheath pipe 11 with a gap 13 therebetween. A tube 14 made of soft polyvinyl chloride having an elliptical cross section is inserted into the gap 13. Then, the two rows of the outer peripheral surface of the tube 14 along the longitudinal direction on the major axis side are in contact with the inner peripheral surface of the sheath tube 11, and 2 along the longitudinal direction on the minor axis side of the inner peripheral surface. The row portion is in contact with the outer peripheral surface of the insertion tube, and the contact portion is welded.

To obtain the double pipe structure shown in FIG. 1, for example, the following method is adopted. First, the inner tube 12 is inserted into a tube 14 whose inner diameter is considerably larger than the outer diameter of the inner tube 12 and whose outer diameter is smaller than the inner diameter of the sheath tube 11, and the tube 14 is flattened. The two rows of the inner peripheral surface along the longitudinal direction are brought into contact with the outer peripheral surface of the insertion tube 12, and the contact portion is heated and welded in this state. Next, the obtained product is pulled into the sheath tube 11 so that two or more rows of the outer peripheral surface of the tube 14 along the longitudinal direction are brought into contact with the inner peripheral surface of the sheath tube 11.

FIG. 2 is a sectional view showing another example of the structure of the double pipe of the present invention. Reference numeral 2 denotes a double pipe, in which a cylindrical insertion pipe 22 is inserted into a cylindrical sheath pipe 21 with a gap 23. In the gap 23, a tube 24 having an elliptical cross section and having protrusions 241 and 241 in two rows along the longitudinal direction on the major axis side of the outer peripheral surface thereof is inserted and attached. Then, the two rows of ridges 241,
241 is in contact with the inner peripheral surface of the sheath tube 21, and the two rows of the inner peripheral surface along the longitudinal direction on the shorter diameter side are inserted into the inner tube 2.
3 is abutted on the outer peripheral surface and the abutting portion is fused.

FIG. 3 is a sectional view showing still another example of the structure of the double pipe of the present invention. Reference numeral 3 is a double pipe, which is a cylindrical insertion pipe 3 with a gap 33 formed in a cylindrical sheath pipe 31.
2 is inserted. In the gap 43, the cross-sectional outer shape is a rhombus, and four ridgelines 341 along the longitudinal direction are formed on the outer peripheral surface thereof.
The tube 34 provided with ... Is inserted.

4 along the longitudinal direction of the outer peripheral surface of the tube 34
The ridge lines 341 of the book are in contact with the inner peripheral surface of the sheath tube 31, and the four rows of parts along the longitudinal direction corresponding to the sides of the inner peripheral surface are in contact with the outer peripheral surface of the insertion tube 33. The contact portion is fused.

[0022]

Since the structure of the double pipe of the present invention is constructed as described above, the work of pulling the insertion pipe into the sheath pipe for piping is easy and the noise prevention by the water hammer is improved. Are better.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of the structure of a double pipe of the present invention.

FIG. 2 is a cross-sectional view showing another example of the structure of the double pipe of the present invention.

FIG. 3 is a sectional view showing still another example of the structure of the double pipe of the present invention.

[Description of sign]

 1,2,3 Double pipe 11,21,31 Sheath pipe 12,22,32 Internal pipe 14,24,34 Tube

Claims (1)

[Claims] 1. In a double pipe in which a cylindrical insertion tube is inserted with a gap in a cylindrical sheath tube, a tube having a cross-sectional outer shape is inserted in the gap, and an outer peripheral surface of the tube is attached. Characterized in that two or more rows along the longitudinal direction of the sheath are in contact with the inner peripheral surface of the sheath tube, and two or more rows along the longitudinal direction of the inner peripheral surface are in contact with the outer peripheral surface of the insertion tube. And the structure of double piping.