Multicore cable

Abstract

To provide a multicore cable capable of preventing an infiltration of water to an inside.SOLUTION: A multicore cable includes; a core having a plurality of coated electric wires twisted together; a tape member disposed outside the core and wound in spiral along a longer direction of the core; and a sheath disposed outside the tape member. In the tape member, an absorption amount of water being a length of a distribution area of water absorbed when an end part along the longer direction is immersed in water is 4 mm / 10 mins. or less.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a multi-core cable.

Background Art

[0002] Patent Document 1 discloses an electrical insulating cable including a core wire, a first covering layer formed to cover the core wire, and a tape member disposed in a wound state around the core wire between the core wire and the first covering layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Depending on the installation environment of the multi-core cable, water may enter from the first end along the longitudinal direction of the multi-core cable and reach the second end located opposite to the first end of the multi-core cable. For electrical equipment connected to the second end, water may cause malfunctions and deterioration, so there has been a demand for a multi-core cable that can suppress the intrusion of water into the multi-core cable.

[0005] Therefore, an object of the present disclosure is to provide a multi-core cable that suppresses the intrusion of water into the interior.

Means for Solving the Problems

[0006] The multi-core cable of the present disclosure includes a core formed by twisting a plurality of covered electric wires, a tape member disposed outside the core and spirally wound along the longitudinal direction of the core, and an outer covering disposed outside the tape member. The tape member has a water uptake amount of 4 mm / 10 minutes or less, which is the length of the region where the water sucked up when the end along the longitudinal direction is immersed in water is distributed.

Advantages of the Invention

[0007] According to the present disclosure, it is possible to provide a multi-core cable that suppresses the intrusion of water into the interior.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0009] The modes for carrying out the invention will be described below.

[0010] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described. In the following description, the same or corresponding elements are denoted by the same reference numerals, and the same description thereof will not be repeated.

[0011] (1) A multi-core cable according to an aspect of the present disclosure includes a core in which a plurality of covered electric wires are twisted together, a tape member disposed outside the core and spirally wound along the longitudinal direction of the core, and an outer covering disposed outside the tape member. The tape member has a water uptake amount of 4 mm / 10 minutes or less, which is the length of the region where the water sucked up when the end along the longitudinal direction is immersed in water is distributed. The tape member has a water uptake amount of 4 mm / 10 minutes or less, which is the length of the region where the water sucked up when the end along the longitudinal direction is immersed in water is distributed.

[0012] By setting the water absorption amount of the tape member to 4 mm / 10 minutes or less, it is possible to make the tape member less likely to absorb water, suppress the intrusion of water into the multi-core cable due to the transmission of the tape member, and form a multi-core cable with suppressed water intrusion into the interior.

[0013] (2) In (1), the core is formed by twisting together two first electric wires and a pair-twisted electric wire. The pair-twisted electric wire is formed by twisting together two second electric wires. The outer diameter of the second electric wire may be smaller than the outer diameter of the first electric wire.

[0014] By twisting together two coated electric wires of the same configuration to form a pair-twisted electric wire, it is possible to make the signal transmitted by the coated electric wire less susceptible to noise.

[0015] By making the outer diameter of the second electric wire smaller than the outer diameter of the first electric wire, the outer diameter of the pair-twisted electric wire can be made closer to the outer diameter of the first electric wire. For this reason, the outer shape in a cross-section perpendicular to the longitudinal direction of the multi-core cable can be made closer to a circular shape.

[0016] [Details of Embodiments of the Present Disclosure] A specific example of a multi-core cable according to an embodiment of the present disclosure (hereinafter referred to as "this embodiment") will be described below with reference to the drawings. Note that the present invention is not limited to these examples, and is indicated by the claims of the patent, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0017] In this specification, when explaining members such as a first electric wire, a second electric wire, a first conductor, a second conductor, a first insulator, and a second insulator, the names of the members may be appended with first, second, etc. The first, second, etc. are merely described for the purpose of identifying each member and preventing confusion during the explanation, and do not represent the arrangement, priority, etc. For this reason, when there is no particular risk of confusion or when explaining collectively, they can be simply referred to as electric wires, conductors, insulators, etc. [Multi-Core Cable] Figures 1 and 2 show a configuration example of a cross-section perpendicular to the longitudinal direction of the multi-core cable of the present embodiment. The Z-axis in FIG. 1 corresponds to the axis along the longitudinal direction of the multi-core cable 10 and the multi-core cable 20. The XY plane is a plane perpendicular to the longitudinal direction of the multi-core cable 10 and the multi-core cable 20.

[0018] The multi-core cable 20 shown in FIG. 2 is the same as the multi-core cable 10 shown in FIG. 1 except that the configurations of a plurality of covered electric wires are different. Therefore, the description will be mainly made with reference to FIG. 1, and FIG. 2 will be used for description as necessary.

[0019] As shown in FIG. 1, the multi-core cable 10 of the present embodiment includes a core 100 formed by twisting a plurality of covered electric wires 11, a tape member 12 disposed outside the core 100 and spirally wound along the longitudinal direction of the core 100, and an outer sheath 13 disposed outside the tape member 12.

[0020] Each member included in the multi-core cable of the present embodiment will be described. (1) Core (1-1) Regarding the members included in the core The core 100 has a plurality of covered electric wires 11. (1-1-1) Regarding the covered electric wire The configuration and number of the covered electric wires 11 included in the core 100 are not particularly limited and can be selected according to equipment connected to the multi-core cable 10 or the like.

[0021] The plurality of covered electric wires 11 included in the multi-core cable 10 can be twisted to form the core 100. In addition to the covered electric wires 11 described below, the multi-core cable 10 can also include coaxial cables, drain wires, etc. as necessary.

[0022] The core 100 of the multi-core cable 10 shown in FIG. 1 has a configuration in which two first electric wires 11A are twisted together.

[0023] The core 200 of the multi-core cable 20 shown in FIG. 2 has a configuration in which two first electric wires 11A and a pair-twisted electric wire 21 are twisted together.

[0024] The covered wire 11 and the twisted pair wire 21 will be described in order below. (A) Covered wire The covered wire 11 can have a conductor 111 and an insulator 112 that covers the outer surface of the conductor 111.

[0025] The first wire 11A which is the covered wire 11 can have a first conductor 111A and a first insulator 112A that covers the outer surface of the first conductor 111A.

[0026] Regarding the second wire 11B which is the covered wire 11 that the multi-core cable 20 shown in FIG. 2 has, it can also have a second conductor 111B and a second insulator 112B that covers the outer surface of the second conductor 111B.

[0027] The configuration example of each member that the covered wire 11 has will be described. (A-1) Conductor The conductor 111 can have a single wire conductor strand or a plurality of conductor strands. When the conductor has a plurality of conductor strands, the plurality of conductor strands can be twisted together. That is, when the conductor 111 has a plurality of conductor strands, the conductor can also be a stranded wire of the plurality of conductor strands.

[0028] The material of the conductor 111 is not particularly limited, but for example, a copper alloy or copper can be used. As the copper, soft copper or hard copper can also be used. It may also be plated with tin or silver. (A-2) Insulator The material that constitutes the insulator 112 is not particularly limited, but it can include a resin material.

[0029] As the resin material, for example, one or more selected from polyolefin resins such as polyethylene, polypropylene, and polymethylpentene, polyolefin copolymers such as ethylene vinyl acetate, ethylene ethyl acrylate, and ethylene methyl acrylate copolymer, fluororesins such as polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and ethylene-tetrafluoroethylene copolymer (ETFE), polyester resins such as polyethylene terephthalate (PET), etc. can be used. The resin material contained in the insulator may or may not be cross-linked.

[0030] The insulator 112 can be composed only of the above resin material, but the insulator 112 can also contain one or more additives selected from flame retardants, flame retardant aids, antioxidants, lubricants, colorants, reflection imparting agents, concealing agents, processing stabilizers, plasticizers, etc. in addition to the resin material.

[0031] In the first electric wire 11A and the second electric wire 11B of the multi-core cable 20 shown in FIG. 2, the materials and configurations of the conductor 111 and the insulator 112 may be different. The outer diameter D11B of the second electric wire 11B of the multi-core cable 20 shown in FIG. 2 may be smaller than the outer diameter D11A of the first electric wire 11A.

[0032] By making the outer diameter D11B of the second electric wire 11B smaller than the outer diameter D11A of the first electric wire 11A, the outer diameter D21 of the twisted pair wire 21 can be made closer to the outer diameter D11A of the first electric wire 11A. Therefore, the outer shape in the cross section perpendicular to the longitudinal direction of the multi-core cable 20 can be made closer to a circle. When the outer diameter D11B of the second electric wire 11B is about half of the outer diameter D11A of the first electric wire 11A, the outer shape in the above cross section of the multi-core cable 20 can be made particularly close to a circle. (B) Twisted pair wire As in the case of the multi-core cable 20 shown in FIG. 2, for example, some of the covered wires 11 of the core 200 can be pre-twisted in advance to form a pair-twisted wire or the like. The pair-twisted wire 21 included in the multi-core cable 20 shown in FIG. 2 is formed by twisting two second wires 11B together.

[0033] By twisting two covered wires 11 having the same configuration together to form a pair-twisted wire 21, the signal transmitted by the covered wire 11 can be made less susceptible to noise. (2) Tape member The tape member 12 can be wound spirally along the longitudinal direction of the core 100.

[0034] Since the multi-core cable 10 includes the tape member 12, it becomes easier to remove the outer sheath from the multi-core cable 10 and take out the core.

[0035] The inventor of the present invention examined the cause of water entering from the first end of the multi-core cable and reaching the second end.

[0036] Even in conventional multi-core cables, a tape-like member also called a restraining wrap or the like was disposed between the core and the outer sheath. Therefore, the inventor of the present invention examined the entry of water into the multi-core cable due to such a tape-like member.

[0037] Here, the length of the region where the water sucked up when the end along the longitudinal direction of the tape member 12 is immersed in water for 10 minutes is referred to as the "water suction amount of the tape member".

[0038] As a result of the above examination, by setting the water suction amount of the tape member 12 to 4 mm / 10 minutes or less, it is possible to make the tape member 12 less likely to absorb water. Then, by suppressing the entry of water into the multi-core cable 10 through the tape member 12, a multi-core cable 10 with suppressed entry of water into the interior can be obtained. The water suction amount of the tape member 12 may be 3.5 mm / 10 minutes or less.

[0039] The smaller the water absorption amount of the tape member, the more preferable it is. However, if the tape member does not absorb any water at all, it may be difficult to remove the outer covering when taking out the core. Therefore, the water absorption amount of the tape member may be 0.1 mm / 10 minutes or more.

[0040] The tape member 12 is not particularly limited as long as it is a material that satisfies the above range of water absorption amount and can be used. For example, a viscose-containing paper tape can be used. Non-woven fabrics, woven or knitted fibers, or resin thin films can also be used as long as their water absorption amounts are within the above range.

[0041] The winding direction of the tape member 12 may be the same as or opposite to the twisting direction of the covered electric wire 11 that constitutes the core 100. (3) Outer Covering The outer covering 13 can be disposed outside the tape member 12.

[0042] By having the outer covering 13 on the multi-core cable 10, the covered electric wire 11 included in the core 100 can be protected and the durability can be enhanced. (Resin Material) The outer covering 13 can contain a resin material. The resin material is not particularly limited. For example, polyolefin-based resins such as polyethylene, polypropylene, and ethylene-vinyl acetate copolymer (EVA), polyurethane elastomer (polyurethane resin), polyester elastomer, or a composition formed by mixing at least two of these can be used.

[0043] As shown in FIG. 1, the outer covering 13 can also include a plurality of layers, such as a first outer covering 131 and a second outer covering 132, in order from a position close to the core 100. The outer covering 13 is not limited to the form of two layers shown in FIG. 1. It may be a single layer or may include a plurality of layers of three or more layers. The first outer covering 131 and the second outer covering 132 can be made of different materials or the same material.

[0044] The first outer covering 131 can contain, for example, as the resin, one or more selected from polyurethane resin and polyolefin resin.

[0045] The second outer covering 132 can contain, for example, as the resin, a polyurethane resin having excellent abrasion resistance. Since the second outer covering 132 is arranged to cover the outer surface of the multi-core cable 10, by including the polyurethane resin as the resin material, the durability of the multi-core cable 10 can be enhanced.

[0046] The resin material of the outer covering 13 may or may not be cross-linked. (Additive) In addition to the above resin material, the outer covering 13 can also contain one or more additives selected from flame retardants, antioxidants, deterioration inhibitors, acid acceptors, colorants, cross-linking agents, cross-linking aids, processing aids, fillers, lubricants, etc.

Example

[0047] Specific examples will be given below for explanation, but the present invention is not limited to these examples. (Evaluation method) First, the evaluation method of the multi-core cable manufactured in the following experimental examples will be described. (1) Water absorption amount of the tape member On the bottom surface 32A of the water tank 32 filled with water 33, the end portion 31A along the longitudinal direction of the tape member which is the test body 31 used when manufacturing the multi-core cable was brought into contact, and the tape member which is the test body 31 was installed in a state of being stretched along the longitudinal direction. Then, after 10 minutes from the installation, the length L from the water surface 33A of the region 34 where water is distributed and sucked up by the tape member which is the test body 31 was measured, and it was used as the water absorption amount of the tape member. (2) Water absorption amount of the multi-core cable As the test body 31, instead of the tape member, the multi-core cable manufactured in each experimental example was used, and the evaluation of the water absorption amount of the multi-core cable was performed under the same conditions as the water absorption amount of the tape member except that the test time was changed.

[0048] After 3 hours had elapsed since the multi-core cable, which is the test specimen 31, was placed in the water tank 32, the multi-core cable, which is the test specimen 31, was taken out and its outer covering was removed. Then, in the tape member of the multi-core cable, which is the test specimen 31, the length L from the water surface 33A of the region 34 where the sucked-up water is distributed was measured and taken as the water suction amount of the multi-core cable. (Experimental conditions, results) The multi-core cables manufactured in each experimental example will be described below.

[0049] The multi-core cables of Experimental Example 1 to Experimental Example 4 below were produced. Experimental Example 1, Experimental Example 2, and Experimental Example 3 are examples, and Experimental Example 4 is a comparative example. [From Experimental Example 1 to Experimental Example 4] A multi-core cable 20 having a structure of a cross-section perpendicular to the longitudinal direction shown in FIG. 2 was produced, and the water suction amount of the multi-core cable was evaluated. Note that the outer diameter D11B of the second electric wire 11B is smaller than the outer diameter D11A of the first electric wire 11A.

[0050] A viscose-containing paper tape was used as the tape member of the multi-core cable 20. Viscose-containing paper tapes with different viscose contents were used in Experimental Example 1 to Experimental Example 3. Experimental Example 4 uses a paper tape that does not contain viscose.

[0051] The water suction amount was evaluated for the tape member used when manufacturing the multi-core cable and the manufactured multi-core cable.

[0052] The evaluation results are shown in Table 1. When tested with the multi-core cable, if the water suction amount is 200 mm / 3 hours or more, it was judged that the water suction amount is too much and the intrusion of water into the cable could not be suppressed.

[0053]

Table 1

Explanation of symbols

[0054] 10 Multi-core cable 20 multi-core cable 100 cores 200 cores 11 coated electric wires 111 conductors 112 insulators 11A first electric wire D11A outer diameter of the first electric wire 111A first conductor 112A first insulator 11B second electric wire D11B outer diameter of the second electric wire 111B second conductor 112B second insulator 21 twisted pair wires D21 outer diameter of the twisted pair wires 12 tape members 13 outer sheath 131 first outer sheath 132 second outer sheath 31 test specimen 31A end 32 water tank 32A bottom surface 33 water 33A water surface 34 region where water is distributed L length

Claims

1. a core formed by twisting a plurality of covered electric wires; a tape member disposed outside the core and spirally wound along the longitudinal direction of the core; an outer covering disposed outside the tape member, and having: a multi-core cable, wherein the tape member has a water uptake amount of 4 mm / 10 minutes or less, which is the length of a region where water sucked up when an end portion along the longitudinal direction is immersed in water is distributed.

2. the core is formed by twisting two first electric wires and a pair-twisted electric wire; the pair-twisted electric wire is formed by twisting two second electric wires; the multi-core cable according to claim 1, wherein an outer diameter of the second electric wire is smaller than an outer diameter of the first electric wire.

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