JPH06294482A - Pressure tube - Google Patents

Abstract

PURPOSE:To provide a double tube having large strength and small flow resistance and holding large compressive strength by spirally curving a hard hollow pipe, forming a tube main body using the hollow pipe as a tube wall, and integrally connecting and fixing side faces of the hollow pipe. CONSTITUTION:Opposite side faces 2a, 2b of the preceding spiral curve section and the succeeding spiral curve section of a hard hollow pipe 2 having a square cross section and continuously and spirally curved at the same curvature are integrally stuck with a proper adhesive 3 to form a tube main body. Even if the tube wall is large in thickness and the diameter is large, the whole weight is reduced, the handling is made easy, and inner and outer faces of the tube wall formed by the hollow pipe 2 are connected in series in the length direction of a tube to form the structure of the double tube. When a load is applied, the pressure can be distributed in the peripheral direction and the length direction of the tube, and the prescribed compressive strength can be held.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure protection tube suitable for use as a large-diameter wire protection tube requiring pressure resistance and other underground buried tubes.

[0002]

2. Description of the Related Art Conventionally, fume pipes and cast iron pipes have been used because they are required to have pressure resistance as underground buried pipes, but they are heavy due to their diameter and are difficult to handle. It has difficulty in sex. Therefore, for example, as described in Japanese Utility Model Publication No. 61-141889,
A tube body has been developed in which a reinforcing strip made of a thin metal plate having a U-shaped cross section is spirally embedded in a tube wall of a synthetic resin tube formed in a spiral wave shape.

[0003]

However, according to such a tube body, the reinforcing strips, which are spirally wound and buried, have a gap between the opposite edges thereof and have no connectivity with each other. Since it does not have, it is not possible to dispersively support the external pressure in the adjacent portion when the external pressure acts, therefore, the overall pressure resistance is poor, the larger the diameter of the pipe,
There is a problem in that the strength is reduced. The present invention provides a pressure resistant tube intended to solve such problems.

[0004]

In order to achieve the above object, the synthetic resin pipe of the present invention is constructed by bending a rigid hollow pipe 2 in a spiral shape as shown in the drawings corresponding to the embodiments. 2 forms a pipe main body 1 serving as a pipe wall, and opposite side surfaces of the hollow pipe 2 are integrally joined and fixed to each other.

[0005]

Since the pipe wall of the pipe main body 1 is composed of the hard hollow pipe 2 which is curved in a spiral shape, even if the pipe wall has a large thickness and a large diameter, the overall weight is reduced and the handling becomes easy. In addition, the inner and outer surfaces of the pipe wall formed by the hollow pipe 2 are connected in series in the length direction of the pipe to form a double pipe structure of the inner and outer pipes, and the adjacent hollow pipes 2 which are curved in a spiral shape. Since the opposing surfaces of the pipe are integrally joined and fixed, the pressure can be dispersed even in the circumferential and lengthwise portions of the pipe when a load is applied, and the prescribed pressure strength is maintained. is there.

[0006]

Embodiments of the present invention will now be described with reference to the drawings.
Reference numeral 1 is a pipe main body, and a rigid hollow pipe 2 having a rectangular cross section curved in a continuous spiral shape with the same degree of curvature is provided with appropriate side faces 2a and 2b of the preceding spiral curved portion and the succeeding spiral curved portion. It is formed by integrally bonding with the adhesive 3. The hard hollow pipe 2 forming the pipe main body 1 may be made of metal such as iron or steel, or may be made of hard synthetic resin. Further, the adhesive 3 is used. Opposite sides 2 without
Alternatively, the a and 2b may be welded together to be integrally joined and fixed.

Inner and outer surfaces of the hollow pipe 2 forming the pipe main body 1
2c and 2d respectively form inner and outer pipe walls of the pipe main body 1 which are continuous in a lengthwise direction of the pipe to form a smooth surface. FIG. 3 shows another embodiment of the present invention. In the pressure resistant pipe of the above embodiment, the inner and outer peripheral surfaces of the pipe main body 1 are coated with an appropriate adhesive 3 or directly to coat the inside and outside synthetic resins. The layers 4 and 5 are formed.

As described above, by providing the synthetic resin coating layers 4 and 5 on the inner and outer peripheral surfaces of the pipe main body 1, the inner and outer peripheral surfaces of the pipe main body 1 can be finished to be smoother and the pipe main body 1 can be made of metal. In the case of, corrosion can be prevented.

FIG. 4 shows still another embodiment of the present invention. In each of the embodiments, one hollow pipe 2 is continuously curved in a spiral shape so that its inner and outer surfaces 2a and 2b are in the longitudinal direction. Although it is formed as a double pipe connected in series, it is formed as a multiple pipe in this embodiment.

That is, similar to the above-mentioned embodiment, a hard hollow pipe 2 having a rectangular cross-section curved in a continuous spiral shape is provided with a side surface 2a opposed to a preceding spiral curved portion and a succeeding spiral curved portion.
The inner double pipe B having a small diameter is formed by sequentially joining and fixing 2b with an appropriate adhesive 3 or by welding.
And a large-diameter double pipe A whose inner diameter fits to the outer periphery of the double pipe B is wound around the small-diameter double pipe B while being similarly formed by the hard hollow pipe 2. Tube A
Adhesive to the inner peripheral surface of the outer double pipe A in a state where the joint side faces 2a, 2b of the hollow pipe 2 are positioned at an intermediate portion between adjacent joint side faces of the hollow pipe 2 forming the other double pipe B. The outer peripheral surface of the inner double pipe B is joined via 3 or by welding,
It is one that is integrated.

FIG. 5 shows a pressure resistant tube in which synthetic resin coating layers 4 and 5 are applied to the inner and outer peripheral surfaces of the multiplex tube. The pressure resistant tube constructed in this way exhibits extremely high pressure resistant strength.

As shown in FIG. 6, the pipe main body 1 described above is
When the hollow pipe 2 is made of metal, after the adhesive 3 is applied to the outer peripheral surface of the hollow pipe 2 by the adhesive extrusion device 6 while being conveyed in the length direction, a plurality of forming rolls 7, 8 and 9 are formed. It is fed and is spirally curved and formed by these forming rolls, and it is continuously formed by adhering the opposing side surfaces 2a and 2b of the preceding spiral curved portion and the succeeding spiral curved portion while pressing them. While forming the pipe main body 1, synthetic resin coating layers 4 and 5 are applied to the inner and outer peripheral surfaces of the pipe main body 1 as necessary.

When the hollow pipe 2 is made of a hard synthetic resin, while the hollow pipe 2 is extruded and formed, the opposing side faces 2a and 2b are welded and integrated with each other by the uncured resin portion while forming the curve. It is a thing. In each of the above embodiments, the rigid hollow pipe 2 has a rectangular cross section, but a circular or other irregular cross section may be used.

[0014]

As described above, according to the pressure resistant tube of the present invention,
Since the rigid hollow pipe is bent in a spiral shape to form a pipe main body having the hollow pipe as a pipe wall, and the opposite side faces of the hollow pipe are integrally joined and fixed to each other, the pipe wall has a spiral shape. Since it consists of a hollow pipe curved in a shape, even if the pipe wall has a large thickness and a large diameter, the overall weight is lighter than that of a fume pipe and the handling is easy. The inner and outer surfaces of the tube wall formed by the hollow pipe 2 can be connected in series in the length direction of the tube to form a structure of an inner-outer double tube having high strength.

When the hollow pipe has a rectangular cross section,
The inner and outer peripheral surfaces of the pipe body are smooth double pipes to reduce the flow resistance in the pipe, and the opposing faces of adjacent hollow pipes that are curved in a spiral shape are integrally joined, so that the load When receiving the pressure, it is possible to disperse the pressure also in the circumferential and lengthwise portions of the pipe, and therefore, it is possible to maintain strong pressure resistance even when formed into a large diameter pipe,
It has uniform and large tensile strength and compressive strength over the entire length.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view,

FIG. 2 is a partially enlarged vertical side view,

FIG. 3 is a vertical sectional side view showing another embodiment of the present invention,

FIG. 4 is a vertical sectional side view showing still another embodiment of the present invention,

5 is a vertical cross-sectional side view of a pressure resistant tube shown in FIG.

FIG. 6 is a simplified diagram showing a manufacturing method.

[Explanation of symbols]

 1 Main pipe 2 Hollow pipe 3 Adhesive

Claims (4)

[Claims] 1. A pressure resistant pipe formed by bending a rigid hollow pipe in a spiral shape to form a pipe main body having the hollow pipe as a pipe wall, and integrally joining and fixing opposite side surfaces of the hollow pipe. 2. The rigid hollow pipe is made of metal.
Pressure tube described. 3. The pressure resistant pipe according to claim 1, wherein the hard hollow pipe is made of a hard synthetic resin. 4. The pressure resistant pipe according to claim 1, wherein at least one of the inner peripheral surface and the outer peripheral surface of the pipe main body is coated with a resin.