Cable line

Abstract

To provide a cable line that has an excellent heat dissipation, and can distribute a cable in compact.SOLUTION: A cable line of the present disclosure, is a cable line to which a plurality of cables is distributed. The plurality of cables is adjacently arranged each other, the cable comprises one or a plurality of electric wires; and an external coated layer arranged to a circumference of one or the plurality of electric wires. Each electric wire includes: a conductor obtained by twisting a conductor or a plurality of element wires formed by a single wire; and an insulation layer coating an outer periphery of the conductor. At least one cable of the plurality of cables is a heat dissipation cable, and a heat transmission ration under 25°C any one of or both of the insulation layer and the external coating layer in the heat dissipation cable is 0.40 W / m*K or larger.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to cable runs.

[0002] Generally, cross-linked polyethylene insulated vinyl sheath cables (CV cables) that use cross-linked polyethylene as the insulating material are widely used as power cables. Power cables are configured, for example, by covering multiple conductors, insulated electric wires, with an insulating layer covering the periphery of the insulated electric wires.

[0003] In cable lines, when multiple cables are laid in close contact with each other, heat tends to build up, which impairs the heat dissipation of the entire cable line. For this reason, multiple cables are arranged with a gap between them in order to reduce the allowable current or to make it easier to dissipate heat by utilizing air convection. In response to this, a conventional technique has been proposed that proposes a large-capacity cable line in which a two-piece metal case made of a nonmagnetic metal material is attached to a cable assembly formed by closely assembling single-core cables adjacent to each other so as to surround the entire length of the cable assembly, and heat dissipation fins are provided along the entire length of the metal case. This allows the cable line to have a compact configuration that is economical, and reduces the magnetic field that causes communication problems (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Publication No. 61-022441 Summary of the Invention

[0005] The cable line of the present disclosure is a cable line in which a plurality of cables are laid, the plurality of cables being arranged adjacent to one another, the cables comprising one or more electric wires and an outer sheath layer arranged around the one or more electric wires, the electric wires having a conductor consisting of a solid wire or a conductor formed by twisting together a plurality of strands, and an insulating layer covering the outer periphery of the conductor, at least one cable of the plurality of cables is a heat dissipating cable, and either or both of the insulating layer and the outer sheath layer in the heat dissipating cable have a thermal conductivity at 25°C of 0.40 W / m·K or more. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic configuration diagram showing a cable line according to a first embodiment. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing a heat dissipative cable according to the first embodiment. [Diagram 3] FIG. 3 is a schematic configuration diagram showing a cable line according to another embodiment. [Figure 4] FIG. 4 is a schematic configuration diagram showing a cable line according to another embodiment. [Diagram 5] FIG. 5 is a schematic configuration diagram showing a cable line according to another embodiment. [Figure 6] FIG. 6 is a schematic configuration diagram showing a cable line according to another embodiment. [Figure 7] FIG. 7 is a schematic configuration diagram showing a cable line according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] [Problem that this disclosure aims to solve] In recent years, the amount of power consumption has increased with the increase in the amount of information. Therefore, the conductor resistance of the cable line that supplies power increases with the increase in the current flowing through it, and power loss is likely to occur. In the above-mentioned conventional technology, the cables are arranged in close proximity to each other, while the surface area is expanded by providing heat dissipation fins along the entire length of the metal case, making it easy to disperse the trapped heat. However, arranging a metal case with heat dissipation fins along its entire length may not be sufficient to meet the demand for compact cable installation. On the other hand, the conductor resistance can also be reduced by increasing the cross-sectional area of ​​the conductor, but in this case, the volume of the cable line also increases.

[0008] An object of the present disclosure is to provide a cable line that has excellent heat dissipation properties and enables compact cable installation.

[0009] [Effects of this disclosure] According to the present disclosure, it is possible to provide a cable line that has excellent heat dissipation properties and enables compact cable installation.

[0010] [Description of the embodiments of the present disclosure] First, the embodiments of the present disclosure will be listed and described.

[0011] The cable line of the present disclosure includes: (1) A cable line in which a plurality of cables are laid, the plurality of cables being arranged adjacent to one another, the plurality of cables comprising one or more electric wires and an outer sheath layer arranged around the one or more electric wires, the plurality of electric wires comprising a conductor made of a single wire or a conductor made of a plurality of strands twisted together, and an insulating layer covering the outer periphery of the conductor, at least one of the plurality of cables being a heat dissipating cable, and either or both of the insulating layer and the outer sheath layer in the heat dissipating cable having a thermal conductivity of 0.40 W / m·K or more at 25°C.

[0012] The cable line has excellent heat dissipation properties and allows for compact cable installation. The inventors have found that by arranging at least one heat dissipating cable in the cable line and placing the multiple cables adjacent to each other in a state where the cables are in close contact with each other, heat that tends to build up inside is released while being conducted through the heat dissipating cable without arranging any equipment such as fins. The cable line has the above configuration, which suppresses a decrease in allowable current caused by placing multiple cables in close contact, and allows for a compact arrangement by placing the multiple cables adjacent to each other. Therefore, the cable line has excellent heat dissipation properties, can suppress a temperature rise of the conductor, reduce power loss, and allows for compact cable installation. Here, "arranged adjacent to each other" means that each cable is in contact with at least one other cable in the cable line configuration.

[0013] (2) In the above (1), all of the cables may be the heat dissipation cables. When all of the cables in the cable line are the heat dissipation cables, heat dissipation can be further improved.

[0014] (3) In the above (1), the heat dissipative cable may be arranged in a central portion. By arranging the heat dissipative cable in a central portion of the cable line, heat dissipation can be further improved. The "central portion" refers to a region excluding a range of 30% of the entire length in the row direction from both ends in the row direction in a cross-sectional view of the cable line.

[0015] (4) In the above (1), the cables may be arranged in multiple stages, with the heat dissipative cable being arranged in the top stage. By arranging the heat dissipative cable in the top stage in the cable line, heat dissipation can be further improved. The "multiple stages" means that the cables are arranged in two or more stages in the vertical stage direction.

[0016] (5) In any one of (1) to (4) above, in the heat dissipating cable, either or both of the insulating layer and the outer jacket layer contain a resin component, a first filler, and a second filler, the resin component contains an olefin resin and a resin incompatible with the olefin resin, the olefin resin and the resin incompatible with the olefin resin form a sea-island structure, the first filler is made of graphite, the second filler is made of a metal oxide, a metal hydroxide, or a combination thereof, a mass ratio of the first filler to the resin component is 10 / 100 or more and 80 / 100 or less, and the volume resistivity of either or both of the insulating layer and the outer jacket layer in the heat dissipating cable is 1×10 13 The electrical resistance may be Ω·cm or more. In the cable line, either or both of the insulating layer and the jacket layer in the heat dissipating cable contain an olefin-based resin with a large crystal content as the resin component, thereby improving the tensile strength and oil resistance. Also, either or both of the insulating layer and the jacket layer in the heat dissipating cable contain the first filler made of graphite and the second filler made of a metal oxide, a metal hydroxide or a combination thereof, and the mass ratio of the first filler to the resin component is 10 / 100 or more and 80 / 100 or less, thereby improving thermal conductivity. Therefore, the heat of the conductor is easily released to the outside, and the effect of suppressing the temperature rise of the conductor is high. Also, the volume resistivity of either or both of the insulating layer and the jacket layer in the heat dissipating cable is 1×10 13 By having a resistivity of Ω·cm or more, the insulation and voltage resistance of the cable included in the cable line can be improved. Furthermore, by the resin component including an olefin resin and a resin incompatible with the olefin resin forming a sea-island structure, the first filler, which is difficult to disperse in the olefin resin, can be unevenly distributed in the incompatible resin, thereby further improving the heat dissipation of either or both of the insulating layer and the outer jacket layer in the heat dissipation cable. Therefore, in the cable line, the temperature rise of the conductor can be further suppressed to reduce power loss, and the insulation, mechanical strength, and oil resistance of either or both of the insulating layer and the outer jacket layer in the heat dissipation cable can be improved.

[0017] The above-mentioned "volume resistivity" refers to an electrical resistance value measured by a double ring electrode method based on JIS-K6271:2008. The above-mentioned "resin incompatible with olefin-based resin" refers to a resin incompatible with olefin-based resin, and can be confirmed, for example, by observing a cross section perpendicular to the longitudinal direction of the electric wire in the insulating layer or the outer covering layer using a transmission electron microscope (TEM). The olefin-based resin and the incompatible resin are observed to have a sea-island structure when the cross section is observed with an electron microscope. By adopting such a dispersed state of the sea-island structure, the physical property behaviors originating from both the olefin-based resin and the resin incompatible with this olefin-based resin appear independently, and the mutual incompatibility allows the properties of both resins to be fully exhibited.

[0018] [Details of the embodiment of the present disclosure] Hereinafter, a cable line according to an embodiment of the present disclosure will be described in detail with reference to the drawings as appropriate.

[0019] <Cable line> A plurality of cables are laid in the cable line. For example, a cable rack (horizontal ladder type), a conduit, a trough, a cable pit, a ring metal fitting, or a C-shaped metal fitting can be used as a support for the cable line. The cable includes one or more electric wires and an outer sheath layer arranged around the one or more electric wires. The electric wire includes a conductor and an insulating layer that covers the outer periphery of the conductor. In the cable line, at least one of the plurality of cables is a heat dissipating cable.

[0020] In the cable line, the lower limit of the thermal conductivity at 25°C of either or both of the insulating layer and the outer jacket layer in the heat dissipating cable is 0.40 W / m·K, or may be 0.50 W / m·K or 0.60 W / m·K. By setting the lower limit of the thermal conductivity at 25°C of either or both of the insulating layer and the outer jacket layer in the heat dissipating cable to 0.40 W / m·K, the heat dissipation of the cable line can be improved.

[0021] In the cable line, the lower limit of the volume resistivity of either or both of the insulating layer and the outer jacket layer in the heat dissipating cable is 1×10 13 Ω cm may be 1×10 15 Ω cm may be 2×10 15 The volume resistivity of the insulating layer 3 may be 1×10 13 By setting the resistance to Ω·cm or more, the insulation properties and voltage resistance of the heat dissipating cable provided in the cable line can be improved.

[0022] [First embodiment] FIG. 1 is a schematic diagram showing a cable line according to the first embodiment, showing a cross section of a plurality of cables laid in two rows and three columns. A cable line 10 according to the first embodiment may include a general-purpose cable 8 other than a heat dissipative cable 5. In the cable line 10, one heat dissipative cable 5 and five general-purpose cables 8 are arranged adjacent to each other. The heat dissipative cable 5 includes an electric wire 1 having an insulating layer 3 and an outer jacket layer 4 arranged around the electric wire 1. In the general-purpose cable 8, the insulating layer of the electric wire is not particularly limited and may be made of a known synthetic resin for insulating layers, and the outer jacket layer is also not particularly limited and may be made of a known synthetic resin for outer jacket layers.

[0023] [Heat dissipating cable] In the heat dissipative cable laid in the cable line 10 according to the first embodiment, the insulating layer 3 of the electric wire 1 has a thermal conductivity of 0.40 W / m·K or more at 25°C.

[0024] An example of a heat dissipating cable is shown in Fig. 2. Heat dissipating cable 5 includes an electric wire 1 having a conductor 2 and an insulating layer 3 covering the outer periphery of this conductor 2, and an outer jacket layer 4 arranged around the electric wire 1. That is, in a cross-sectional shape, heat dissipating cable 5 has a configuration in which the conductor 2, the insulating layer 3, and the outer jacket layer 4 are laminated concentrically.

[0025] The outer diameter of the heat dissipative cable 5 is appropriately designed depending on the application, but the lower limit of the outer diameter may be 10 mm or 15 mm. On the other hand, the upper limit of the outer diameter of the heat dissipative cable 5 may be 80 mm, 60 mm, or 50 mm.

[0026] (Electric wire) The electric wire 1 includes a conductor 2 and an insulating layer 3 that covers the outer periphery of the conductor 2. The conductor 2 may be a conductor made of a single wire or a conductor made by twisting together a plurality of wires. In the electric wire 1, an additional layer such as a primer treatment layer may be provided between the conductor 2 and the insulating layer 3.

[0027] <conductor> The conductor 2 is a metal linear body that is responsible for the electrical conduction of the electric wire 1. Examples of the conductor 2 include a round wire having a circular cross-sectional shape, a rectangular wire having a rounded square cross-sectional shape, and a rectangular wire having a rounded rectangular cross-sectional shape. The conductor 2 may be a single linear body as shown in Fig. 2, or a twisted wire body in which multiple thin wires are twisted together.

[0028] The material for the conductor 2 may be, for example, a metal such as copper, aluminum, nickel, silver, or iron, or an alloy thereof, but from the viewpoints of electrical conductivity and workability, copper or aluminum may be used. The conductor 2 may also have a multi-layer structure in which a coating made of another metal is laminated on the outer peripheral surface of a metal linear body.

[0029] The lower limit of the average cross-sectional area (including the gaps between the wires) of the conductor 2 is 2 mm 2 may be 8mm 2 It may be 14mm 2 On the other hand, the upper limit of the average cross-sectional area of ​​the conductor 2 is 600 mm 2 may be 500 mm 2 may be 400 mm 2When the average cross-sectional area of ​​the conductor 2 is equal to or greater than the above lower limit, a sufficient current can flow. When the average cross-sectional area of ​​the conductor 2 is equal to or less than the above upper limit, sufficient bending resistance can be obtained. Here, the "average cross-sectional area" refers to the average value of values ​​measured at any ten points on the cross section.

[0030] Insulating layer The insulating layer 3 may contain a resin component, a first filler and a second filler.

[0031] The average thickness of the insulating layer 3 is not particularly limited, but the lower limit of the average thickness may be, for example, 0.8 mm or 1.0 mm. On the other hand, the upper limit of the average thickness of the insulating layer 3 may be 10 mm or 7 mm. When the average thickness of the insulating layer 3 is equal to or greater than the lower limit, the insulating properties of the insulating layer 3 can be improved. When the average thickness of the insulating layer 3 is equal to or less than the upper limit, the flexibility can be improved. Here, the "average thickness" refers to the average value of thicknesses measured at any ten points. Note that the same definition is used hereinafter when referring to "average thickness" for other members, etc.

[0032] The insulating layer 3 may contain an olefin-based resin as a resin component. When the insulating layer 3 contains an olefin-based resin as a resin component, the tensile strength and oil resistance can be improved. Examples of the olefin-based resin include polypropylene (PP) and polyethylene (PE).

[0033] Examples of polypropylene include homopolypropylene, random polypropylene, and block polypropylene. Examples of random polypropylene include propylene-α-olefin copolymers, which are copolymers of propylene and ethylene or α-olefins having 4 to 20 carbon atoms. Block polypropylene is a resin composed of homopolypropylene as a main component, random copolymer elastomer as a copolymer component, and an ethylene polymer as an optional component.

[0034] Examples of polyethylene include high density polyethylene (PE), very low density polyethylene (VLDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and cross-linked polyethylene.

[0035] The olefin resin may be polypropylene, or may be random polypropylene or block polypropylene. When the olefin resin is random polypropylene or block polypropylene, it is possible to improve the tensile strength and oil resistance while suppressing a significant decrease in tensile elongation.

[0036] The resin component may contain, in addition to the olefin resin, a resin incompatible with the olefin resin. By containing the resin incompatible with the olefin resin, the first filler, which is difficult to disperse in the olefin resin, can be unevenly distributed in the resin incompatible with the olefin resin, thereby further improving the heat dissipation property.

[0037] The olefin resin and the resin incompatible with the olefin resin may form a sea-island structure. The resin component includes an olefin resin and a resin incompatible with the olefin resin, and these resins form a sea-island structure, whereby the first filler unevenly distributed in the incompatible resin can be dispersed, thereby further improving heat dissipation.

[0038] Examples of resins that are incompatible with olefin resins include styrene copolymers, polyvinyl chloride, polyurethane, fluororesins, fluororubbers, and silicones. Among these, styrene copolymers that have good dispersibility of the first filler and can improve tensile elongation may be used. The incompatible resins may include one or more types.

[0039] Examples of styrene-based copolymers include styrene-ethylene block copolymers (SE), styrene / ethylene-butylene / ethylene block copolymers (SEBC) or their hydrogenated products, styrene / ethylene-butylene / styrene block copolymers (SEBS) or their hydrogenated products, styrene / ethylene-propylene / styrene block copolymers (SEPS), styrene / ethylene-ethylene-propylene-styrene block copolymers (SEEPS), and hydrogenated styrene butadiene rubber (HSBR).

[0040] The lower limit of the content of the structural unit derived from styrene in the styrene-based copolymer may be 5% by mass or 8% by mass. The upper limit of the content of the structural unit derived from styrene may be 40% by mass or 38% by mass. By setting the content of the structural unit derived from styrene in the above range, the tensile elongation and oil resistance can be further improved.

[0041] When the resin component contains a styrene copolymer as a resin incompatible with the olefin resin, the lower limit of the mass ratio of the styrene copolymer to the olefin resin may be 20 / 80 or 30 / 70. The upper limit of the mass ratio of the styrene copolymer to the olefin resin may be 80 / 20 or less or 70 / 30. By setting the mass ratio of the styrene copolymer to the olefin resin within the above range, the tensile properties, heat dissipation properties and oil resistance can be further improved.

[0042] The insulating layer 3 may contain a resin other than the olefin resin and the resin used as the incompatible resin, such as polyvinyl chloride, polyurethane, fluororesin, fluororubber, silicone, or polyester resin.

[0043] <First filler> The first filler is made of graphite. When the insulating layer contains the first filler made of graphite, electrical conductivity can be increased and heat dissipation can be improved.

[0044] The lower limit of the mass ratio of the first filler to the resin component may be 10 / 100, 20 / 100, or 25 / 100. The upper limit of the mass ratio of the first filler to the resin component may be 80 / 100, 75 / 100, or 70 / 100. By setting the mass ratio of the first filler to the resin component within the above range, it is possible to achieve both heat dissipation and insulation properties and to achieve good compatibility.

[0045] The lower limit of the average particle size of the graphite may be 0.5 μm, 1 μm, or 5 μm. Meanwhile, the upper limit of the average particle size may be 100 μm, 50 μm, or 30 μm. When the average particle size of the graphite is 0.5 μm or more, the thermal conductivity at 25° C. can be improved. Meanwhile, when the average particle size of the graphite is 100 μm or less, the tensile elongation can be improved. When the average particle size of the graphite is within the above range, the heat dissipation can be further improved. The above-mentioned "average particle size" means the median diameter (D50) which is the value at which the volume-based cumulative distribution calculated in accordance with JIS-Z-8819-2:2001 is 50%. Specifically, the median diameter (D50) can be a value measured by the following method. Measurement is performed using a laser diffraction type particle size distribution measuring device as a measuring device. A scattering measurement mode is adopted, and a laser beam is irradiated onto a wet cell in which the dispersion liquid in which the particles of the sample to be measured are dispersed in a dispersion solvent is circulated, and the scattered light distribution is obtained from the measurement sample.Then, the scattered light distribution is approximated by a log-normal distribution, and the particle diameter at the cumulative degree of 50% (D50) is taken as the median diameter.

[0046] The insulating layer 3 contains a second filler made of a metal oxide, a metal hydroxide, or a combination thereof. When the insulating layer 3 contains a second filler made of a metal oxide, a metal hydroxide, or a combination thereof, the heat dissipation property and the insulating property can be improved.

[0047] Examples of the metal oxide include magnesium oxide, zinc oxide, aluminum oxide, titanium oxide, and calcium oxide.

[0048] Examples of the metal hydroxide include magnesium hydroxide, aluminum hydroxide, and calcium hydroxide.

[0049] The lower limit of the mass ratio of the second filler to the resin component may be 30 / 100 or 50 / 100. The upper limit of the mass ratio of the second filler to the resin component may be 200 / 100 or 180 / 100. In the electric wire, when the mass ratio of the second filler to the resin component is within the above range, both the insulation property and the tensile elongation can be well achieved.

[0050] The lower limit of the average particle size ratio of the first filler to the second filler may be 1.1 or 5.0. When the average particle size ratio of the first filler to the second filler is 1.1 or more, the heat dissipation property can be further improved. The upper limit of the average particle size ratio of the first filler to the second filler is not particularly limited, but may be, for example, 100 times or less from the viewpoint that the tensile elongation decreases when the particle size of graphite is too large.

[0051] The insulating layer 3 may contain other additives as necessary. Examples of such additives include a flame retardant, a flame retardant assistant, an antioxidant, a lubricant, a colorant, a reflectivity imparting agent, an opacifying agent, a processing stabilizer, and a plasticizer.

[0052] <Outer coating layer> The main component of the outer layer 4 is not particularly limited as long as it is a synthetic resin having excellent abrasion resistance, and examples thereof include polyvinyl chloride, polyethylene, polyethylene, and chloroprene. The outer layer 4 may be crosslinked.

[0053] The outer covering layer 4 may contain the additives exemplified for the insulating layer 3 .

[0054] The average thickness of the outer covering layer 4 is preferably 0.5 mm or more and 3.0 mm or less.

[0055] [Heat dissipating cable manufacturing method] The heat dissipating cable can be obtained by a manufacturing method including a step of producing an electric wire (electric wire producing step) and a step of covering one or more electric wires with an outer jacket layer (outer jacket layer covering step). In the heat dissipating cable of the cable line in the first embodiment, the thermal conductivity of the insulating layer at 25°C is 0.40 W / m K or more.

[0056] (Process for producing electric wire) The process for producing the electric wire is not particularly limited, but may include, for example, the following steps. (1) A step of preparing an insulating layer-forming composition for forming an insulating layer (an insulating layer-forming composition preparation step) (2) A step of coating a conductor with the insulating layer-forming composition (insulating layer-forming composition coating step)

[0057] (1) Preparation of composition for forming insulating layer In the insulating layer forming composition preparation step, an insulating layer forming composition for forming an insulating layer is prepared. The insulating layer forming composition is prepared by mixing a resin component, a filler, and other additives as necessary, for example, with a melt mixer. As the melt mixer, a known one, for example, an open roll, a Banbury mixer, a pressure kneader, a single-shaft mixer, or a multi-shaft mixer can be used. The insulating layer-forming composition of the present disclosure may be crosslinked by any of chemical crosslinking, silane crosslinking, and radiation crosslinking.

[0058] (2) Insulating layer forming composition coating process The insulating layer-forming composition coating step can be performed, for example, by a method of extruding the insulating layer-forming composition onto the conductor using a melt extruder, whereby the insulating layer, which is an extrusion molded body, is coated onto the conductor.

[0059] (Outer layer coating process) In the outer jacket layer covering step, for example, a melt extruder is used to extrude an insulating layer forming composition for forming an outer jacket layer onto the outside of one or more electric wires obtained in the electric wire manufacturing step, thereby covering the outside of one or more electric wires with an outer jacket layer.

[0060] After coating with the jacket layer, the wire or wires are cooled to harden the jacket layer and obtain a heat dissipating cable, which is then wound and collected.

[0061] The method for producing a heat dissipating cable may further include a step of crosslinking the resin component of the jacket layer (crosslinking step). This crosslinking step may be performed before or after coating the composition forming the jacket layer on the outside of one or more electric wires (after the jacket layer is formed).

[0062] [How to make cable lines] A method for producing the cable line includes, for example, a step of preparing a plurality of cables including at least one heat dissipating cable, and a step of laying the plurality of cables in multiple rows and columns so that they are arranged adjacent to each other as shown in Fig. 1. A general-purpose cable can also be laid in the cable line. In addition, the insulation layer of the heat dissipating cable has a thermal conductivity of 0.40 W / m K or more at 25°C.

[0063] This cable line has excellent heat dissipation properties and allows for compact cable installation.

[0064] [Second embodiment] 3 is a schematic diagram showing a cable line according to a second embodiment. In the cable line 20, a plurality of cables are arranged adjacent to each other in multiple stages, and a heat dissipative cable 5 is arranged in the center. In the cable line 20, the heat dissipative cable 5 is arranged in the center, thereby further improving heat dissipation. When a plurality of cables are arranged adjacent to each other in multiple stages, the heat dissipative cable 5 may be arranged in all the centers of each stage, or the heat dissipative cable 5 may be arranged only in the centers of some stages.

[0065] [Third embodiment] 4 is a schematic diagram showing a cable line according to a third embodiment. In the cable line 30, a plurality of cables are arranged adjacent to each other in multiple stages, and a heat dissipative cable 5 is arranged in the entire uppermost stage. In the cable line 30, by arranging the heat dissipative cable 5 in the entire uppermost stage, it is possible to further improve heat dissipation.

[0066] [Fourth embodiment] 5 is a schematic diagram showing a cable line according to a fourth embodiment. In the cable line 40, a plurality of cables are arranged in multiple stages, and the heat dissipative cable 5 is arranged in the entire lowest stage. In the cable line 40, the heat dissipation performance can be further improved by arranging the heat dissipative cable 5 in the entire lowest stage.

[0067] [Fifth embodiment] 6 is a schematic diagram showing a cable line according to a fifth embodiment. In the cable line 50, a plurality of cables are arranged adjacent to each other in multiple stages, and all of the cables are made of heat dissipative cables 5. In the cable line 50, all of the cables are made of heat dissipative cables 5 and are arranged adjacent to each other, thereby further improving heat dissipation.

[0068] [Sixth embodiment] 7 is a schematic diagram showing a cable line according to a sixth embodiment. In the cable line 60, a plurality of cables are laid in parallel. In the cable line 60, a plurality of cables are arranged adjacent to each other in one row, and all of the cables are composed of heat dissipative cables 5. Even when a plurality of cables are laid in parallel in one row in this way, by arranging the heat dissipative cables 5 adjacent to each other, it is possible to have excellent heat dissipation properties, suppress the temperature rise of the conductor, reduce power loss, and enable compact cable laying.

[0069] [Other embodiments] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is not limited to the configurations of the above-described embodiments, but is indicated by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0070] The heat dissipating cable included in the cable line of the above embodiment is not particularly limited as long as the insulation layer of the electric wire has a thermal conductivity of 0.40 W / m·K or more at 25°C and the main component of the coating layer is a synthetic resin with excellent abrasion resistance, but the heat dissipating cable included in the cable line is not limited thereto. The heat dissipating cable included in the cable line may have an outer coating layer with a thermal conductivity of 0.40 W / m·K or more at 25°C and the insulation layer of the electric wire may be made of a known synthetic resin for insulation layers. Moreover, the heat dissipating cable included in the cable line may have both the insulation layer and the outer coating layer of the electric wire with a thermal conductivity of 0.40 W / m·K or more at 25°C.

[0071] When the thermal conductivity of the jacket layer of the heat dissipative cable included in the cable line at 25°C is 0.40 W / m·K or more, the jacket layer may have the same configuration as the insulating layer having a thermal conductivity of 0.40 W / m·K or more at 25°C. For example, the jacket layer of the heat dissipative cable may contain a resin component, a first filler, and a second filler, the resin component may include an olefin resin and a resin incompatible with the olefin resin, the olefin resin and the resin incompatible with the olefin resin form a sea-island structure, the first filler may be made of graphite, the second filler may be made of a metal oxide, a metal hydroxide, or a combination thereof, and the mass ratio of the first filler to the resin component may be 10 / 100 or more and 80 / 100 or less. This makes it possible to further suppress a temperature rise in the conductor in the cable line, reduce power loss, and improve the insulation, mechanical strength, and oil resistance of the jacket layer in the heat dissipative cable.

[0072] In the cable line of the above embodiment, a heat dissipating cable including one electric wire is laid, but the shape of the heat dissipating cable is not particularly limited. For example, the heat dissipating cable may include a core wire formed by twisting together a plurality of electric wires having the same diameter, an inner coating layer disposed around the core wire, and an outer coating layer disposed around the inner coating layer. In this case, the manufacturing method of the heat dissipating cable may include a step of twisting together a plurality of electric wires, a step of forming the inner coating layer, and a step of winding a tape member. EXAMPLES

[0073] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0074] <Wire No.K1~No.K9> Single-layer insulating layers No. K1 to No. K9 were produced by the following procedure.

[0075] [Resin component] 1. Olefin resin The following components were used as the olefin-based resin in the resin component. (1) Random polypropylene (random PP) MFR 1.3 (g / 10 min), flexural modulus 950MPa (2) Very low density polyethylene (VLDPE) (3) Cross-linked polyethylene (cross-linked PE) The melt flow rate (MFR) is a value measured using a melt indexer at a measurement temperature of 230° C. and a load of 2.16 kg according to a method in accordance with JIS-K7210-1:2014 (Method A: Mass Measurement Method). The flexural modulus is a value measured according to a method in accordance with JIS-K7171:2016. 2. Styrene copolymer The following styrene-based copolymer was used as a resin incompatible with the olefin-based resin in the resin component. (1) Styrene / ethylene-butylene / styrene block copolymer (SEBS) (styrene structural unit content: 12% by mass) Shore A hardness 42 (2) SEBS (styrene structural unit content: 18% by mass) Shore A hardness 67 The term "Shore A hardness" refers to the hardness measured by a type A durometer based on JIS-K6253: 2012. The term "content of styrene structural units" refers to the content of structural units derived from styrene in the styrene-based copolymer.

[0076] [First filler] As the first filler, the following two types of graphite were used. (1) Thin graphite (average particle size 22 μm) (2) Spherical graphite (average particle size 20 μm)

[0077] [Second filler] As the second filler, the following two types of filler were used. (1) Magnesium hydroxide (average particle size 0.8 μm) (2) Zinc oxide type 1 (average particle size 0.75 μm)

[0078] Using the above resin component, first filler and second filler, compositions for forming insulating layers No. K1 to No. K9 were prepared. The composition and content of the insulating layer are shown in Table 1. "-" indicates that the corresponding component was not used.

[0079] [Creating the insulating layer] The insulating layers No. K1 to No. K9 were produced by extrusion molding using the insulating layer-forming composition. An extrusion die was used for the extrusion molding. The extrusion molding was performed at a die temperature of 180° C. and a linear speed of 5 m / min, and insulating layers No. K1 to No. K9 with an average thickness of 2.7 mm were obtained.

[0080] <Wire No.K1~No.K9> Electric wires No. K1 to No. K9 were produced according to the following procedure. Conductor cross-sectional area is 38 mm2 The electric wires No. K1 to No. K9 were produced with an outer diameter of 9.4 mm and a length of 3 m, in which the outer circumference of the conductor was covered with an insulating layer No. K1 to No. K9 with an average thickness of 1.2 mm. Of the electric wires No. K1 to No. K9, No. K1 to No. K7 are electric wires for heat dissipation cables, and No. K8 and No. K9 are electric wires for general-purpose cables.

[0081] [Insulation layer and wire evaluation] The insulation layers and electric wires of No. K1 to No. K9 were evaluated for thermal conductivity, volume resistivity, tensile strength, tensile elongation, tensile strength and tensile elongation after oil resistance tests, conductor temperature when current is applied, withstand voltage, and the presence or absence of a sea-island structure in the cross section of the insulation layer.

[0082] (Thermal Conductivity) A press sheet measuring φ150 mm x thickness 0.5 mm was prepared as a test sample from the composition for forming an insulating layer using a heat press machine, and the thermal conductivity at 25°C was measured in accordance with ISO-22007-3 (temperature wave method). A higher thermal conductivity [W / m K] indicates a higher heat dissipation property of the insulating layer. A thermal conductivity of 0.40 W / m K or higher at 25°C can be said to have excellent heat dissipation properties.

[0083] (Volume resistivity (insulation)) A press sheet measuring φ150 mm and thickness 1 mm was prepared as a test sample from the composition for forming an insulating layer using a heat press machine, and electrical resistance was measured using the double ring electrode method defined in JIS-K6271:2008. The volume resistivity was calculated from the measured value. A higher volume resistivity [Ω·cm] value indicates higher insulating properties of the insulating layer. The volume resistivity is expressed as a value of 1×10 13 When the resistance is Ω·cm or more, the insulating layer has excellent insulating properties.

[0084] (tensile strength and tensile elongation) The tensile strength [MPa] and tensile elongation [%] of each insulating layer were measured in accordance with JIS-K7162: 1994. When the tensile strength is 10 MPa or more and the tensile elongation is 200% or more, the mechanical strength of the insulating layer can be said to be excellent.

[0085] (Tensile strength and tensile elongation after oil resistance test) Based on JIS-C3005:2014, the specimens were immersed in JIS No. 2 test oil at 70℃ for 4 hours, after which the retention rate [%] of tensile strength [MPa] and tensile elongation [%] was measured to evaluate the oil resistance. The tensile strength [MPa] and tensile elongation [%] of the insulating layer were measured in accordance with JIS-K7162:1994. The retention rate Y of each of the tensile strength and tensile elongation was calculated by the following formula. Remaining rate Y[%]=C 3 / C 2 In the above formula, C 2 is the tensile strength or tensile elongation before immersion, and C 3 is the tensile strength or tensile elongation after immersion. The greater the tensile strength retention and tensile elongation retention after the oil resistance test, the better the oil resistance. When the tensile strength retention is 80% or more and the elongation retention is 60% or more, the oil resistance of the insulating layer can be said to be good.

[0086] (Whether or not the insulating layer has an island structure) The presence or absence of a sea-island structure in the cross section of the insulation layer was determined by preparing thin-film sections from the insulation layers taken from wires No. K1 to No. K9 using the freezing microtome method, staining the samples with ruthenium tetroxide, osmium tetroxide, tungsten phosphate, etc., and observing them under a transmission electron microscope and visually judging.

[0087] (Conductor temperature when current is applied) The conductor temperature during current flow was measured by passing a current of 230 A through the electric wires No. K1 to No. K9 and measuring the temperature of the conductor surface at the center of the electric wires.

[0088] (Voltage resistance) In accordance with JIS-C3605:2002, the electric wires No. K1 to No. K9 were charged with 2000V and evaluated for the presence or absence of dielectric breakdown. The evaluation was made according to the following two stages. When the evaluation was A, the effect was good. A: No insulation breakdown has occurred. B: Dielectric breakdown occurred.

[0089] The evaluation results of the insulating layers and electric wires of Nos. K1 to K9 are shown in Table 1.

[0090] [Table 1]

[0091] The results in Table 1 show that the insulation layers of Tests No. K1 to No. K7, in which the thermal conductivity of the insulation layer at 25°C was 0.40 W / m K or more, had a lower conductor temperature when current was applied, compared to the insulation layers of Tests No. K8 and K9, in which the thermal conductivity was less than 0.40 W / m K. Volume resistivity is 1×10 13 The insulating layers of Test No. K1 to Test No. K9, which had a resistance of Ω·cm or more, showed good results in the withstand voltage test. In addition, the insulating layers of Test Nos. K1 to K7, in which the insulating layers contain an olefin-based resin and a resin incompatible with the olefin-based resin as resin components, the olefin-based resin and the incompatible resin forming a sea-island structure, the first filler is graphite, and the second filler is a metal oxide or metal hydroxide, and the mass ratio of the first filler to the resin component is 10 / 100 or more and 80 / 100 or less, had excellent heat dissipation properties, oil resistance, and mechanical strength.

[0092] <Cable No.K1, No.K7, No.K8 and No.K9> Cables No. K1, No. K7, No. K8 and No. K9 were produced according to the following procedure.

[0093] First, the outer jacket layers No. S1 and No. S2 were manufactured by extrusion molding using the composition for forming the outer jacket layer shown in Table 2. No. S1 is a heat-dissipating outer jacket layer (thermal conductivity 0.65 W / m K) and has the same composition as the heat-dissipating insulating layer K1. No. S2 is a general-purpose outer jacket layer (thermal conductivity 0.25 W / m K) made of polyvinyl chloride.

[0094] Cables No. K1, No. K7, No. K8 and No. K9 were made by covering the electric wires No. K1, No. K7, No. K8 and No. K9 with a polyvinyl chloride outer sheath layer S2 having an average thickness of 1.5 mm. Cables No. K1 and No. K7 are heat dissipating cables, and cables No. K8 and No. K9 are general-purpose cables.

[0095] [Table 2]

[0096] <Cable line evaluation> (Conductor temperature when heat dissipating cable and general-purpose cable are combined) Using heat-dissipating cables and general-purpose cables, cable lines No. 1 to No. 8 were fabricated, in which six cables were laid in two rows and three columns as shown in Table 3. The six cables were laid adjacent to each other using cable ties. Three types of heat-dissipating cables were used: a cable combining a heat-dissipating insulation layer No. K1 (thermal conductivity 0.65 W / m·K) and a general-purpose outer jacket layer S2 (thermal conductivity 0.25 W / m·K), a cable combining a general-purpose insulation layer No. K9 (thermal conductivity 0.28 W / m·K) and a heat-dissipating outer jacket layer S1 (thermal conductivity 0.65 W / m·K), and a cable combining a heat-dissipating insulation layer No. K1 and a heat-dissipating outer jacket layer S1. The general-purpose cable used was a cable combining a general-purpose insulation layer No. K9 and a general-purpose outer jacket layer S2.

[0097] The arrangement of the heat dissipating cables and general-purpose cables in No. 1 to No. 8 is as follows: No.1: All six cables are heat dissipating cables (combination of heat dissipating insulation layer No. K1 and general-purpose outer layer S2) No.2: The two cables in the center of the upper and lower rows are heat dissipating cables (a combination of heat dissipating insulation layer No. K1 and general-purpose outer layer S2) No.3: The cable in the center of the top row is a heat dissipating cable (a combination of heat dissipating insulation layer No. K1 and general-purpose outer layer S2). No.4: The top three cables are heat dissipating cables (a combination of heat dissipating insulation layer No. K1 and general-purpose outer sheath layer S2) No.5: One of the cables at the top end is a heat dissipating cable (a combination of heat dissipating insulation layer No. K1 and general-purpose outer layer S2) No.6: One of the upper end cables is a heat dissipating cable (combination of general-purpose insulation layer No. K9 and heat dissipating outer layer S1) No.7: One of the upper end cables is a heat dissipating cable (a combination of heat dissipating insulation layer No. K1 and heat dissipating outer sheath layer S1) No.8: All six cables are general-purpose cables (combination of general-purpose insulation layer No. K9 and general-purpose outer sheath layer S2)

[0098] Next, a current of 140A was applied, which brings the conductor temperature to around 90°C, and the temperature of the conductor surface in the center of each cable was measured to evaluate the temperature rise when a current was applied when a heat-dissipating cable was combined with a general-purpose cable. The cable conductor temperatures [°C] at each installation position in cable lines No. 1 to No. 8 are shown in Table 3. In addition, in the cable line layout format in Table 3, black circles indicate heat-dissipating cables and white circles indicate general-purpose cables.

[0099] [Table 3]

[0100] As shown in Table 3, in cable lines with six cables laid in two rows and three columns, cable lines No. 1 to No. 7, which include heat-dissipating cables with a thermal conductivity of 0.40 W / m·K or more at 25°C for either or both of the insulation layer and the jacket layer, had a lower maximum conductor temperature than cable line No. 8, which consists of all six general-purpose cables, even though the six cables were laid in close contact with each other. Among them, No. 1, in which all six cables are heat-dissipating cables, and No. 4, in which the three cables in the upper row are heat-dissipating cables, showed particularly good heat dissipation. In addition, a comparison of No. 3, which has one heat-dissipating cable in the center of the upper row, with No. 5 to No. 7, which have one heat-dissipating cable at the end of the upper row, shows that arranging the heat-dissipating cable in the center can reduce the maximum conductor temperature.

[0101] (Conductor temperature when cables with different thermal conductivities are installed for each cable line) Using heat-dissipating cables and general-purpose cables, cable lines No. 9 to No. 12 were fabricated, in which six cables were laid in two rows and three columns as shown in Table 4. The six cables were laid adjacent to each other using cable ties. The heat-dissipating cables used were two types: a cable combining a heat-dissipating insulation layer No. K1 (thermal conductivity 0.65 W / m·K) and a general-purpose outer layer S2 (thermal conductivity 0.25 W / m·K), and a cable combining a heat-dissipating insulation layer No. K7 (thermal conductivity 0.40 W / m·K) and a general-purpose outer layer S2 (thermal conductivity 0.25 W / m·K). The general-purpose cables used were two types: a cable combining a general-purpose insulation layer No. K8 (thermal conductivity 0.25 W / m·K) and a general-purpose outer layer S2, and a cable combining a general-purpose insulation layer No. K9 (thermal conductivity 0.28 W / m·K) and a general-purpose outer layer S2.

[0102] The arrangement of the heat dissipating cables and general-purpose cables in No. 9 to No. 12 is as follows. No.9: All six cables are heat dissipating cables (combination of heat dissipating insulation layer No. K1 and general-purpose outer layer S2) No.10: All six cables are heat dissipating cables (combination of heat dissipating insulation layer No.K7 and general-purpose outer layer S2) No.11: All six are general-purpose cables (combination of general-purpose insulation layer No. K9 and general-purpose outer sheath layer S2) No.12: All six cables are general-purpose cables (combination of general-purpose insulation layer No. K8 and general-purpose outer sheath layer S2)

[0103] Next, a current of 140A was applied and the temperature of the conductor surface in the center of each cable was measured to evaluate the temperature rise when a current was applied when cables with different thermal conductivities were installed for each cable line. The cable conductor temperatures [°C] at each installation position for cable lines No. 9 to No. 12 are shown in Table 4. Note that in the cable line layout format in Table 4, black circles indicate heat dissipating cables and white circles indicate general-purpose cables.

[0104] [Table 4]

[0105] As shown in Table 4, cable lines No. 9 and No. 10, which are made up of heat-dissipating cables with insulating wires with a thermal conductivity of 0.40 W / m K or more at 25°C, had better heat dissipation than cable lines No. 11 and No. 12, which are made up of general-purpose cables, even though all six cables were laid in close contact with each other. Among them, cable line No. 9, whose heat-dissipating cable has a thermal conductivity of 0.65 W / m K, had particularly good heat dissipation.

[0106] The above results demonstrate that the cable line has excellent heat dissipation properties and allows for compact cable installation. [Explanation of symbols]

[0107] 1 electric wire 2 Conductors 3. Insulation layer 4 Outer layer 5. Heat dissipating cable 8 Other general-purpose cables 10, 20, 30, 40, 50, 60 Cable track

Claims

1. A cable line in which a plurality of cables are laid, the plurality of cables are disposed adjacent to one another; the cable comprises one or more electric wires and a jacket layer disposed around the one or more electric wires; The electric wire has a conductor made of a single wire or a conductor made of a plurality of stranded wires, and an insulating layer that covers the outer periphery of the conductor, At least one cable of the plurality of cables is a heat dissipating cable; A cable line in which either or both of the insulating layer and the outer jacket layer in the above heat dissipating cable have a thermal conductivity of 0.40 W / m·K or more at 25° C.

2. 2. The cable run of claim 1, wherein all of said cables are said heat dissipating cables.

3. The cable line according to claim 1 , wherein the heat dissipating cable is disposed in a central portion.

4. The plurality of cables are arranged in multiple stages, The cable line according to claim 1 , wherein the heat dissipating cable is arranged in the uppermost stage.

5. Either or both of the insulating layer and the outer jacket layer in the heat dissipating cable contain a resin component, a first filler, and a second filler; the resin component includes an olefin-based resin and a resin incompatible with the olefin-based resin, the olefin-based resin and a resin incompatible with the olefin-based resin form a sea-island structure, The first filler is made of graphite, The second filler is made of a metal oxide, a metal hydroxide, or a combination thereof; a mass ratio of the first filler to the resin component is 10 / 100 or more and 80 / 100 or less; The volume resistivity of either or both of the insulating layer and the outer jacket layer of the heat dissipating cable is 1×10 １３ The cable line according to any one of claims 1 to 4, wherein the resistance is Ω·cm or more.

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