JP6270701B2 - cable - Google Patents

Description

  The present invention relates to a cable laid on the seabed or waterbed.

  In submarine oil fields and offshore wind power generation facilities, cables that transmit power and signals across the seabed and sea are used. Such cables used in water are provided with iron wire armor on the outer periphery so that they will not be damaged even when subjected to impacts from fishing gear or rods. In general, a strong galvanized iron wire with a diameter of 6 mm or a diameter of 4 mm or more is applied based on the Ministry of Economy, Trade and Industry Ministry Ordinance and electrical equipment technical standards.

  However, in the armoring using a single iron wire, flexibility is inferior and workability at the time of cable laying deteriorates. In order to improve the flexibility of the cable, it has been proposed to use a twisted wire obtained by twisting a plurality of iron wires for armoring (see Patent Document 1).

JP-A-53-146189

  Although the above-mentioned proposal can improve flexibility, in terms of cable protection, the strength is inferior to that of armor using single wires. That is, in the armor of a stranded wire, when a strong object collides, even a relatively small stress is easily crushed and deformed. For this reason, the impact is transmitted to the internal cable core and cannot be protected. As an armor for submarine cables, stranded wires are significantly less robust in terms of robustness than single wires.

  In view of the above problems, an object of the present invention is to provide a cable that can maintain robustness and can improve flexibility.

  According to one aspect of the present invention, the cable is used in water, and includes a cable body and a plurality of corrugated strands that are spirally wound in parallel with each other so as to cover the outer peripheral surface of the cable body. A cable comprising an armor is provided.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the cable which can maintain robustness and can improve flexibility.

It is the schematic which shows an example of the cable which concerns on embodiment of this invention. It is the schematic which shows an example of the strand used for the armor part of the cable which concerns on embodiment of this invention. It is the schematic which shows the other example of the strand used for the armor part of the cable which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  The following embodiments of the present invention exemplify apparatuses and methods for embodying the technical idea of the present invention. The technical idea of the present invention is based on the material and shape of component parts. The structure, arrangement, etc. are not specified below. The technical idea of the present invention can be variously modified within the technical scope described in the claims.

  The cable which concerns on embodiment of this invention is provided with the linear cable main body 2 and the armor part 7 as shown in FIG. The cable body 2 includes a linear core wire 4 and a jacket 6 that covers the core wire 4. The armor portion 7 has a plurality of undulated strands 8. The corrugated strands 8 are spirally wound in parallel with each other so as to cover the outer peripheral surface of the cable body 2.

  The cable body 2 is a linear body such as an electric wire or an optical fiber cable. When the cable body 2 is an electric wire, the core wire 4 is a conductor, and the jacket 6 includes an insulator or the like. When the cable body 2 is an optical fiber cable, the core wire 4 is an optical fiber core wire, and the jacket 6 includes a resin sheath or the like. The cable body 2 may be a single linear body or a plurality of linear bodies. For example, as the cable main body 2, an electric wire operated in a semi-fixed state in water such as undersea exploration, underwater investigation, undersea oil field, and offshore wind power generation, or an electric wire exposed on the surface of a hull that moves in the water Is used.

  For example, an iron wire or a galvanized iron wire can be used as the corrugated wire 8 of the armoring portion 7. As shown in FIG. 2, the corrugated strand 8 has the outer diameter D varied in a wavy manner at a predetermined pitch P in the extending direction of the corrugated strand 8. The outer peripheral surface of the corrugated element wire 8 has a waveform with a fluctuation amplitude V. The corrugated element wire 8 is significantly improved in flexibility as compared with a normal single iron element wire.

  For example, it is desirable that the average value of the outer diameter D is 4 mm to 6 mm, the fluctuation amplitude V on the outer peripheral surface of the corrugated wire 8 is 1 mm to 4 mm, and the pitch P is 2 mm to 180 mm. When the outer diameter D is thinner than 4 mm and the fluctuation amplitude V is larger than 4 mm, the strength of the corrugated element wire 8 is reduced and the robustness of the armored part 7 is impaired. If the pitch P is outside the above range, the flexibility of the corrugated element wire 8 is reduced. Moreover, when the outer diameter D is thicker than 6 mm and the fluctuation amplitude V is smaller than 1 mm, the flexibility of the corrugated element wire 8 is reduced, and the flexibility of the armor portion 7 is also impaired.

  Ordinary submarine cables are basically landed or buried on the seabed. Therefore, it is not necessary to consider the movement of the submarine cable. On the other hand, in floating offshore wind power generation, etc., it is necessary to set up a cable from the sea floor to the sea surface. In such a riser cable rising from the seabed, flexibility is an important factor in addition to robustness in order to cope with fluctuations caused by waves and tidal currents.

  In the embodiment of the present invention, the armored portion 7 is formed by spirally winding a plurality of corrugated strands 8 in parallel with each other so as to cover the outer peripheral surface of the cable body 2. The corrugated element wire 8 is remarkably improved in flexibility even though the strength thereof is almost the same as that of a normal single iron element wire. Therefore, the armoring portion 7 is robust and can realize sufficient flexibility. As a result, it is possible to cope with fluctuations caused by waves and tidal currents when laid in water, and the workability during cable laying can be improved.

  In addition, when the surface of an object such as a linear body is smooth, the boundary layer is separated from the object surface in a viscous fluid, Karman vortices are generated in the flow, and the object receives stress. In the embodiment, a plurality of corrugated strands 8 are wound so as to cover the outer peripheral surface of the cable body 2. As described above, the surface of the corrugated element wire 8 is wavy. Therefore, Karman vortices can be reduced with respect to a water flow coming from a random direction, which is effective in reducing stress caused by the water flow.

  In addition, although the strand which changed the outer diameter to the wave shape is used as the corrugated strand 8, it is not limited. For example, a waved wire 8 whose outer diameter is changed in a triangular wave shape may be used. Alternatively, as shown in FIG. 3, a wavy strand 8 with a wavy bend may be used. In this case, in order to ensure the strength of the armoring portion 7, the outer diameter of the corrugated element wire 8 is preferably about 4 mm to 6 mm. Further, in order to ensure flexibility, it is desirable that the fluctuation amplitude V of the bending of the corrugated element wire 8 is 1 mm to 4 mm and the pitch P is 2 mm to 180 mm.

(Other embodiments)
Although the embodiments of the present invention have been described as described above, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art. Accordingly, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

  The present invention can be applied to a cable laid in water.

2 ... Cable body 4 ... Core wire 6 ... Outer sheath 7 ... Armoring part 8 ... Wire with wave

Claims (3)

A cable used underwater,
A cable body;
A cable comprising: an armoring portion having a plurality of corrugated strands wound spirally in parallel with each other so as to cover an outer peripheral surface of the cable body.   2. The cable according to claim 1, wherein each of the plurality of wavy strands has an outer diameter that is changed in a wavy shape in the extending direction of the wavy strands.   The cable according to claim 1, wherein each of the plurality of corrugated strands is formed by bending the strands into a wave shape.

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