Synthetic resin pipe

Abstract

The present invention provides a synthetic resin pipe with smooth inner and outer surfaces, which can reliably cut off water by flattening the portion of the outer pipe connected with peaks without impairing flexibility. A synthetic resin tube, characterized in that it has: an inner tube (2) formed by winding a strip-shaped synthetic resin into a helical shape; The material is formed by spirally winding the outer wall of the inner tube (2) with the peak of the protruding strip (3) as the outer side; the outer tube (5) made of strip-shaped synthetic resin is arranged along the direction of the tube axis. A part or all of the protruding strips are arranged to connect with the peaks (3a) of the above-mentioned protruding strips along the tube axis direction; the shape-retaining component (10) for the outer tube is embedded in the outer tube (5) or attached to the inner surface side of the outer tube, The outer tube (5) is conformed to make it flat, and is formed of a strip-shaped metal sheet; the outer tube uses a shape-preserving member (10) in a state where a predetermined interval is separated from the peak (3a) of the protrusion (3). winding, and erected on the peak (3a) of the adjacent protrusion.

Description

technical field [0001] The present invention mainly relates to a synthetic resin pipe buried underground, and in particular to a synthetic resin pipe with smooth inner and outer surfaces, which passes through cables for communication and electricity or is used as a pipe for sewage. Background technique [0002] In order to be able to withstand strong internal and external pressures, conventionally used synthetic resin bellows have a smooth inner surface and alternate peaks and valleys on the outer surface in the tube axial direction. [0003] Since such corrugated pipes have irregularities on the outer surface, it is difficult to construct smoothly when installing the pipes, and a special joint structure is required to bury the irregularities and ensure water-cutting performance when the pipes are connected. [0004] Therefore, there has been proposed a synthetic resin in which an outer tube is attached by winding a synthetic resin tape in a state where the crests of the bel...

AI Technical Summary

Problems solved by technology

[0006] However, in the above-mentioned conventional synthetic resin tube, since the synthetic resin tube shrinks in the tube axis direction when the synthetic resin tube is hardened, it cannot be avoided that the part of the outer tube connected to the peak is deformed into a curved state.

If the degree of curvature is large, the purpose of smoothing the outer surface of the synthetic resin tube cannot be achieved.

[0007] In order to prevent the deformation of the outer tube, it is also considered to thicken the outer tube wall, but this will increase the weight of the synthetic resin tube and reduce the flexibility

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