JPH0343506Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to improvements in flexible tubes used to transport high-pressure fluids such as oil, gas, water, and the like.

(Prior Art) This type of flexible tube generally consists of a plastic tube, a first metal reinforcing layer with a small winding pitch provided on the plastic tube, and a first metal reinforcing layer provided on the first metal reinforcing layer. and a second metal reinforcing layer with a large winding pitch. The first metal reinforcing layer is formed by spirally winding a metal strip having a U-shaped or Z-shaped cross section. However, the pressure of the high pressure fluid flowing through the flexible tube causes some of the material of the plastic tube to become loose between adjacent turns of the first metal reinforcement layer and between the inner and outer layers of the first metal reinforcement layer. This has the drawback that the metal reinforcing layer loses its flexibility and the wall thickness of the plastic tube becomes extremely small, making the plastic tube more susceptible to breakage.

(Purpose of the invention) The purpose of the invention is to prevent a part of the plastic pipe from flowing into the gap in the first metal reinforcing layer due to the pressure of high-pressure fluid, thereby reducing the flexibility and wall thickness of the plastic pipe. An object of the present invention is to provide a flexible tube that is not too small.

(Structure of the invention) The flexible tube of the invention comprises a plastic tube, a first metal reinforcing layer with a small winding pitch provided on the plastic tube, and a winding provided on the first metal reinforcing layer. It is characterized by having a tape reinforcing layer which is provided between the plastic tube and the first metal reinforcing layer and is spirally wound in an overlapping manner.

According to this structure, even if a part of the material of the plastic tube tries to flow into the gap between the first metal reinforcing layer due to the high pressure fluid inside the plastic tube, it is blocked by the tape reinforcing layer and the material of the plastic tube is blocked by the first metal reinforcing layer. The plastic tube will not flow into the gaps between the plastic tubes and therefore will not lose its flexibility or thin the plastic tube.

(Embodiment) An embodiment of the present invention will be described in detail with reference to the drawings. The drawings show a flexible tube 10 according to the present invention, and the flexible tube 10 includes a plastic tube 12 and a plastic tube 12 on the plastic tube 12. A first metal reinforcing layer 14 with a small winding pitch is provided, a second metal reinforcing layer 16 with a large winding pitch is provided on the first metal reinforcing layer, and a second metal reinforcing layer 16 with a large winding pitch is provided on the first metal reinforcing layer 14. A plastic sheath 18 is provided. In the illustrated embodiment, the first metal reinforcing layer 14 consists of two inner and outer layer parts 14A and 14B formed by spirally winding a metal strip 15 having a U-shaped cross section, and the outer layer part 14B is an inner layer part. It is wound across adjacent turns of 14A. Further, the second metal reinforcing layer 16 is formed by spirally winding a metal strip 17 having a rectangular cross section.

The flexible tube 10 of the present invention further includes a tape reinforcing layer 20 disposed between the plastic tube 12 and the first metal reinforcing layer 14 and spirally wound in an overlapping manner. The tape reinforcing layer 20 only needs to have enough strength to prevent the material of the plastic tube 12 from flowing into the first metal reinforcing layer 14. For example, a metal tape such as steel, iron, or copper is preferable, and the tape width and thickness For example, the thickness is 0.5 to 3 mm and the width is 30 to 100 mm so as not to lose the flexibility of the tube.
is preferred.

(Effect of the invention) According to the invention, as described above, even if high-pressure fluid flows inside the flexible tube, the material of the plastic tube is blocked by the tape reinforcing layer and flows into the gap in the first metal reinforcing layer. This has the practical benefit of eliminating loss of flexibility and thinning of the plastic tube.

[Brief explanation of drawings]

The drawing is a vertical sectional view showing the upper half of the flexible tube according to the present invention. 10...Flexible tube, 12...Plastic tube, 1
4...First metal reinforcing layer, 16...Second metal reinforcing layer, 20...Tape reinforcing layer.

Claims (1)

[Scope of utility model registration request] A plastic pipe comprising a plastic tube, a first metal reinforcing layer with a small winding pitch provided on the plastic tube, and a second metal reinforcing layer with a large winding pitch provided on the first metal reinforcing layer. A flexible tube, characterized in that the flexible tube has a tape reinforcing layer that is provided between the plastic tube and the first metal reinforcing layer and is spirally wound in an overlapping manner.