JPH05220876A - Pressure-resistant synthetic resin pipe - Google Patents

Abstract

PURPOSE:To provide a synthetic resin pipe composed of a metal resin composite and excellent in pressure-resistant strength and durability. CONSTITUTION:A reinforcing strip plate made of a thin metal plate is wound in a spiral and corrugated shape to be unified with the inner surface of a resin pipe 1 formed into a spiral and corrugated shape and, by welding and unifying the mutual end edges adjacent in the pipe axial direction of the reinforcing plate 2, pressure-resistant strength is imparted and a synthetic resin film 3 is laminated on the inner surface of the reinforcing plate 2 to prevent the corrosion of the reinforcing plate 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin pipe having a high pressure resistance, which is mainly used by being laid in the ground such as a sewer pipe, a drain pipe, a protective pipe for electric wires and telephone lines. Is.

[0002]

2. Description of the Related Art Generally, a pressure-resistant synthetic resin pipe of this type is made of a thin metal plate having a U-shaped cross section, which is substantially similar to the convex or concave portion of the pipe in the wall thickness of the resin pipe formed in a spiral wave shape. By embedding the reinforcing strip in a spiral shape, the reinforcing strip strongly resists external pressure from the vertical direction or diagonal direction to the pipe axis such as earth pressure, and exerts a great pressure resistance as a whole pipe. Along with
Since the entire outer surface of this reinforcing strip is covered with a resin material, corrosion of the reinforcing strip due to the influence of groundwater, etc. can be suppressed and the desired compressive strength can be maintained even when used for many years. Was there.

[0003]

However, in the pressure-resistant synthetic resin pipe having the above-mentioned structure, the edge portions of the strips adjacent to each other in the pipe axial direction of the spiral reinforcing strip that bears the compressive strength are completely absent. Since it is not physically connected but is simply embedded in the wound state while the end edges are abutted or separated from each other, the structure is not integrated in terms of strength and, for example, when the external pressure acting on the pipe is not uniform, Not only does the reinforcing strip of the pipe part where external pressure acts locally deforms, impairing the original function of the pipe and lowers the pressure resistance of the entire pipe, but it also adjoins in the pipe axis direction during pipe manufacturing. The butt edge or the separated edge of the reinforcing strips is easily deformed by distortion.

As a result, it becomes difficult to manufacture a pipe having a predetermined shape, and in addition, it is necessary to form and embed the reinforcing strip.
The extrusion molding of the outer resin wall and the inner resin wall must be performed at the same time, and there is a problem that the manufacturing is complicated and laborious. The present invention has been made in view of the above-mentioned circumstances, and the structure and the manufacturing thereof are extremely simple and easy, and while the manufacturing cost is reduced, the spiral reinforcing strips are forcibly integrated into an integrated structure and exhibit a predetermined compressive strength. An object of the present invention is to provide a pressure resistant synthetic resin pipe that can be manufactured.

[0005]

In order to achieve the above object, a pressure-resistant synthetic resin pipe according to the present invention is provided with a pressure-resistant synthetic resin pipe which is wound along the inner surface of a spiral-wave resin pipe. A synthetic resin film is laminated on the inner exposed surface of a reinforcing strip made of a thin metal plate having a substantially U-shaped cross section so as to be substantially similar to a convex or concave portion, and an edge portion of the reinforcing strip adjacent to each other in the pipe axis direction. The resin pipe is characterized in that it is welded and fixed locally or over the entire area along the spiral direction at the wave-shaped peaks or valleys of the resin pipe.

[0006]

According to the pressure-resistant synthetic resin pipe of the present invention having the above-mentioned structure, when the resin pipe is buried in the ground and used, the spiral-shaped resin pipe and its inner surface are protected against external pressure such as earth pressure. The reinforcing strips made of thin metal plates that are wound and cooperate to oppose each other, but in this case, the edge portions of the reinforcing strips that are adjacent to each other in the pipe axis direction are locally or entirely. Since it is integrally welded together, the spiral reinforcement strip becomes a strong integrated structure, and when external pressure is concentrated on the local part of the pipe, the stress is widely dispersed in the spiral reinforcement strip. The local deformation of the reinforcing strips is prevented, and strong pressure resistance is achieved while using a thin metal plate.

Further, since the outer side of the above-mentioned spiral reinforcing strip is covered with a spiral resin tube and the inside is laminated with a synthetic resin film, the reinforcement strip is prevented from corrosion and is caused by the corrosion. It is also possible to sufficiently suppress the decrease in pressure strength, and yet it is possible to form the spiral corrugated tube by using a reinforcing strip made of a thin metal plate in advance, and wind the strip-shaped resin strip material on it. However, the structure and the manufacturing thereof are extremely simple, and the cost can be reduced.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a partially cutaway front view of a pressure resistant synthetic resin pipe, FIG.
1 is an enlarged vertical sectional view of the main part of FIG. 1, in which FIG.
Is a resin strip material 1A having an arc-shaped cross section and having projecting edges 1a and 1b projecting laterally outward from both open ends thereof.
Is a spiral-wave-shaped resin tube formed by sequentially winding spirally in a state where adjacent projecting edges 1a and 1b are superposed and fused to each other.

Reference numeral 2 is a reinforcing strip plate spirally wound along the inner surface of the resin pipe 1, and the reinforcing strip plate 2 is, for example, 0.3 mm.
It is made by bending a thin metal plate such as a thin iron plate or a steel plate of about 1.0 mm into a substantially U-shaped cross section that is substantially similar to the convex or concave portion of the resin pipe 1, and the synthetic resin film 3 is formed on the inner surface thereof.
Are laminated.

In actual manufacturing, the reinforcing strips 2 are spirally wound, and the end edges of the reinforcing strips 2 adjacent to each other in the pipe axis direction are spirally wound at the peaks of the corrugations. A spiral reinforcing tube body 2A having a strong integrated structure is produced by locally welding and integrating 4 in a point shape or in a linear shape over the entire area along the direction, and on the outer surface of the spiral reinforcing tube body 2A. The above-described resin strip material 1A is spirally wound.

3 and 4 respectively show another embodiment of the present invention. In the embodiment shown in FIG. 3, the end portions of the reinforcing strips 2 adjacent to each other in the tube axis direction are corrugated. It is the one that is locally welded and fixed in the valley portion. In comparison between the embodiment shown in FIG. 3 and the embodiment shown in FIGS. 1 and 2,
For example, when used as a protective tube for electric wires / telephone wires, it is more advantageous to weld at the crests of the corrugations as shown in FIGS. 1 and 2 in order to prevent frictional wear of the welded portion 4 when inserting the electric wires or telephone wires. Is.

In the embodiment shown in FIG. 4, both the resin pipe wall 1 and the reinforcing strip 2 are formed in a spiral corrugation having a rectangular cross section.

[0013]

As described above, according to the present invention, there is provided a metal-resin composite structure including a spirally-shaped resin tube and a reinforcing strip made of a thin metal plate having a substantially U-shaped cross section which is substantially similar to the corrugated shape. Although it is a heavy pipe, it is possible to obtain a pipe excellent in pressure resistance while reducing the wall thickness of the resin pipe portion by the thin metal plate reinforcing strip to increase the effective diameter relative to the pipe diameter (outer diameter). In particular, according to the present invention, the reinforcement wound in a spiral shape by locally welding and fixing the edge portions of the reinforcing strips to be installed which are adjacent to each other in the pipe axis direction along the spiral direction locally. By making the band plate an integral structure in terms of strength, it is possible to further increase the pressure resistance relative to the wall thickness of the reinforcing band plate, and surely prevent strain deformation of the reinforcing band plate during pipe manufacturing as required. Tubes in the form of can be manufactured.

In addition, since the resin film is laminated on the inner surface of the reinforcing strip, the reinforcing strip made of a thin metal plate is prevented from being corroded and the above-mentioned decrease in pressure resistance is suppressed. This has the effect of maintaining a strong compressive strength.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view,

FIG. 2 is an enlarged vertical sectional view of a main part,

FIG. 3 is an enlarged vertical cross-sectional view of a main part showing another embodiment,

FIG. 4 is an enlarged vertical cross-sectional side view of a main part showing still another embodiment.

[Explanation of symbols]

 1 Resin tube 2 Reinforcement strip 3 Synthetic resin film 4 Welded part.

Claims (1)

[Claims] 1. A reinforcing strip made of a thin metal plate having a substantially U-shaped cross section, which is substantially similar to the convex or concave portion of the pipe, is spirally wound along the inner surface of the resin pipe formed in the spiral wave shape. A synthetic resin film is laminated on the inner exposed surface of the reinforcing strip, and the end portions of the reinforcing strips adjacent to each other in the axial direction of the reinforcing strip are made of resin. A pressure-resistant synthetic resin pipe characterized by being integrally welded along the spiral direction at the wave-shaped peaks or valleys of the above.