Electrical Insulation Cable

Abstract

The electrically insulated cable comprises a core electric wire, a tape member covering the core electric wire, and a covering layer covering the tape member. The core electric wire contains a plurality of insulated electric wires, and each of the insulated electric wires comprises a conductor and an insulation layer covering the conductor. The tape member has a transmittance minimum value of 70% or higher with respect to light having a wavelength of between 400 nm and 800 nm inclusive.

Description

[Technical field]

[0001] The present disclosure relates to an electrical insulated cable. This application claims priority to Japanese Patent Application No. 2019-197607, filed on October 30, 2019. The entire contents of the Japanese Patent Application are incorporated herein by reference. [Background technology]

[0002] The electric parking brake (EPB) system installed in a vehicle uses an electrically insulated cable (EPB cable) that electrically connects the caliper inside the wheelhouse to the electronic control unit on the vehicle body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-156386 A [Patent Document 2] JP 2017-162644 A Summary of the Invention

[0004] The electrical insulated cable according to the present disclosure comprises: A core wire, A tape member covering the core wire; and a coating layer coating the tape member, The core wire includes a plurality of insulated wires, The insulated wire includes a conductor and an insulating layer covering the conductor, The tape member has a minimum transmittance of 70% or more for light having a wavelength in the range of 400 nm or more and 800 nm or less. [Brief description of the drawings]

[0005] [Figure 1] FIG. 1 is a cross-sectional view showing a configuration of an embodiment of an insulated electrical cable according to the present disclosure. [Diagram 2] FIG. 2 is a cross-sectional view showing the configuration of another embodiment of the insulated electrical cable of the present disclosure. [Diagram 3] FIG. 3 is a cross-sectional view showing a configuration of still another embodiment of the insulated electric cable of the present disclosure. [Figure 4] FIG. 4 is a schematic diagram showing a manufacturing apparatus for manufacturing an electric insulated cable according to one aspect of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] [Problem that this disclosure aims to solve] Japanese Patent Application Laid-Open No. 2015-156386 (Patent Document 1) describes a core electric wire formed by twisting together a plurality of core materials each including a conductor and an insulating layer formed to cover the conductor, a first covering layer formed to cover the core electric wire, a second covering layer formed to cover the first covering layer, and a tape member disposed between the core electric wire and the first covering layer in a state of being wound around the core electric wire, the second covering layer being formed of a flame-retardant polyurethane resin, and the cross-sectional area of ​​each of the conductors being 0.18 to 3.0 mm 2 An electrically insulated cable is disclosed that falls within the scope of the present invention.

[0007] Japanese Patent Application Laid-Open No. 2017-162644 (Patent Document 2) describes a first twisted pair wire formed by twisting together a pair of first electric wires each having a first central conductor and a first insulator covering the outer periphery of the first central conductor, a second twisted pair wire formed by twisting together a pair of second electric wires each having a second central conductor and a second insulator covering the outer periphery of the second central conductor, and a third central conductor having a cross-sectional area larger than those of the first central conductor and the second central conductor and a third insulator covering the outer periphery of the third central conductor, the third twisted pair wire having a cross-sectional area larger than those of the first electric wires and the second electric wires. the first twisted pair wires, the second twisted pair wires, and the pair of third electric wires are twisted together in a twisted shape in the same direction, the twisting directions of the two twisted pairs are different from the twisting direction of the assembly, and the twisting direction of the assembly is different from the winding direction of the tape member.

[0008] The tape members in Patent Documents 1 and 2 are made of paper, nonwoven fabric, etc. Therefore, when the tape member covers the core electric wire in the manufacturing process, it is not possible to check the state of the core material (insulated electric wire) constituting the core electric wire in the subsequent process (presence or absence of lumps in the insulating layer, presence or absence of foreign matter, disorder of the twist of the assembly, etc.), and further improvement is required from the viewpoint of increasing the yield.

[0009] The present disclosure has been made in consideration of the above circumstances, and has an object to provide an electrical insulated cable that has excellent visibility of the insulated wire inside even when the core wire is covered with a tape member.

[0010] [Effects of this disclosure] According to the present disclosure, it is possible to provide an insulated electric cable that has excellent visibility of the insulated electric wire inside even when the core electric wire is covered with a tape member.

[0011] [Description of the embodiments of the present disclosure] First, the embodiments of the present disclosure will be listed and described. [1] An electrical insulated cable according to one embodiment of the present disclosure comprises: A core wire, A tape member covering the core wire; and a coating layer coating the tape member, The core wire includes a plurality of insulated wires, The insulated wire includes a conductor and an insulating layer covering the conductor, The tape member has a minimum transmittance of 70% or more for light having a wavelength in the range of 400 nm or more and 800 nm or less.

[0012] In the electrical insulated cable of the present disclosure, the tape member covering the core electric wire is transparent in a predetermined wavelength range. Therefore, even if the core electric wire is covered with the tape member, it is possible to provide an electrical insulated cable that has excellent visibility of the insulated electric wire inside. Here, "visibility" is not limited to the property of being able to be confirmed with the naked eye, but also includes the property of being able to detect an object with, for example, a camera.

[0013] [2] The tape member preferably contains at least one compound selected from the group consisting of cellulose, polyethylene terephthalate, and polyethylene. By specifying in this manner, the electrical insulated cable has even better visibility.

[0014] [3] The thickness of the tape member is preferably 3 μm or more and 200 μm or less. By specifying the thickness in this way, the insulated cable has excellent stability relative to the outer diameter of the core wire in addition to the above-mentioned visibility.

[0015] [4] The covering layer preferably includes a first sheath layer covering the tape member and a second sheath layer covering the first sheath layer. By specifying in this way, the electrical insulated cable can have excellent impact resistance in addition to the above-mentioned visibility. "Impact resistance" means the resistance of the electrical insulated cable to damage caused by external impact.

[0016] [5] Each of the multiple insulated wires has the same diameter as each other, The cross-sectional area of ​​the conductor in the plurality of insulated wires is 1.5 mm 2 More than 3mm 2 It is preferable that the above-mentioned insulated cable has excellent electrical properties and excellent bending resistance.

[0017] [6] The above-mentioned electrically insulated cable is preferably an electrically insulated cable for use in a vehicle. The above-mentioned electrically insulated cable can be suitably used for use in a vehicle.

[0018] [7] The electrically insulated cable is preferably an electrically insulated cable for an electric parking brake. The electrically insulated cable can be suitably used for an electric parking brake.

[0019] [8] The electrically insulated cable is preferably an electrically insulated cable for an antilock braking system. The electrically insulated cable can be suitably used for an antilock braking system.

[0020] [Details of the embodiment of the present disclosure] Hereinafter, one embodiment of the present disclosure (hereinafter, referred to as "the present embodiment") will be described. However, the present embodiment is not limited thereto. In this specification, the notation in the form of "A to Z" means the upper and lower limits of a range (i.e., A or more and Z or less), and when no unit is stated for A and only a unit is stated for Z, the unit of A and the unit of Z are the same.

[0021] Electrically insulated cables The electrically insulated cable according to the present disclosure (hereinafter, sometimes simply referred to as an "electrically insulated cable") is A core wire, A tape member covering the core wire; and a coating layer coating the tape member, The core wire includes a plurality of insulated wires, The insulated wire includes a conductor and an insulating layer covering the conductor, The tape member has a minimum transmittance of 70% or more for light having a wavelength in the range of 400 nm or more and 800 nm or less.

[0022] FIG. 1 is a cross-sectional view showing a configuration of an embodiment of an electric insulated cable according to the present disclosure. An electric insulated cable 50 shown in FIG. 1 is used, for example, for an electric parking brake. The electric insulated cable 50 includes a core electric wire 14, a tape member 15 covering the core electric wire 14, and a covering layer 18 covering the tape member 15. In FIG. 1, the core electric wire 14 includes two insulated electric wires 13. The two insulated electric wires 13 are bundled together by winding the tape member 15 around the outer periphery of the insulated electric wires 13. The insulated electric wires 13 include a conductor 11 and an insulating layer 12 covering the conductor 11. The covering layer 18 includes a first sheath layer 16 covering the tape member 15 and a second sheath layer 17 covering the first sheath layer 16. Each element constituting the electric insulated cable will be described below.

[0023] <Core wire> The core electric wire includes a plurality of insulated electric wires (also called "insulated wires"). In other words, it can be understood that the core electric wire is an assembly of a plurality of insulated electric wires. The core electric wire may be, for example, a twisted wire formed by twisting a plurality of the insulated electric wires.

[0024] The number of insulated electric wires constituting the core electric wire is not particularly limited, and may be, for example, two, four, or six. The diameters (outer diameters) of the multiple insulated electric wires constituting the core electric wire may be the same as each other or different. For example, the core electric wire may be formed by twisting together two or more insulated electric wires each having approximately the same diameter (for example, FIG. 1). Also, the core electric wire may be formed by twisting together multiple insulated electric wires having different diameters (for example, FIG. 2).

[0025] The core wire may include insulated wires for two or more applications. For example, one core wire may be formed by twisting together two or more insulated wires for EPB having substantially the same diameter and one or more insulated wires for signal or ground use having a smaller diameter than the insulated wires for EPB.

[0026] (Insulated Wire) The insulated wire includes a conductor and an insulating layer covering the conductor. In this embodiment, the "conductor" refers to a wire made of a material having electrical conductivity, ductility, and malleability. The material constituting the conductor is not particularly limited, and examples thereof include copper, aluminum, copper alloy, tin-plated copper, and aluminum alloy. The conductor may be a single strand, or a twisted wire in which a plurality of strands (tens to hundreds) are twisted together. The conductor may also be a twisted twisted wire in which the twisted wire is further twisted together.

[0027] When the above-mentioned electrically insulated cable is used for power supply purposes (for example, when it is used as an EPB cable), the cross-sectional area of ​​the above-mentioned conductor (the total cross-sectional area when it is composed of multiple wires) is 1.5 mm 2 More than 3mm 2 Preferably, it is 1.6 mm or less. 2 More than 2.5mm 2 It is more preferable that: When the electrically insulated cable is used for signal lines (for example, when used as an ABS cable), the cross-sectional area of ​​the conductor is 0.13 mm 2 More than 0.5mm 2 Preferably, it is 0.18 mm or less. 2 More than 0.35mm 2It is more preferable that the cross-sectional area of ​​the conductor is equal to or less than this. The cross-sectional area of ​​the conductor can be calculated by the following procedure. First, the diameter of each wire (approximately five wires) is calculated using a micrometer or the like, and the diameters calculated for each wire are averaged to calculate the "average diameter of the wires". Next, the cross-sectional area of ​​each wire is calculated from the calculated average diameter of the wires. At this time, the cross-section of the wires perpendicular to the longitudinal direction is regarded as a circle and its cross-sectional area is calculated. The cross-sectional area of ​​the conductor is calculated by multiplying the calculated cross-sectional area by the number of wires that make up the conductor.

[0028] In one aspect of the present embodiment, the plurality of insulated electric wires each have the same diameter, and the cross-sectional area of ​​the conductor in the plurality of insulated electric wires is 1.5 mm 2 More than 3mm 2 It is preferable that the following conditions are met: Here, the term "same" is not limited to being completely same, but also includes being approximately same.

[0029] Examples of materials constituting the insulating layer include polyolefin resins. The polyolefin resin is preferably a flame-retardant polyolefin resin. The flame-retardant polyolefin resin can be produced, for example, by blending a flame retardant with a normal polyolefin resin. By making the insulating layer out of a flame-retardant polyolefin resin, the flame retardancy and insulation of the core wire (insulated wire) can be ensured even if the coating layer or tape member is removed and a part of the core wire (insulated wire) is exposed.

[0030] Examples of the polyolefin resin include, but are not limited to, high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), very low density polyethylene (VLDPE), ethylene-vinyl acetate copolymer resin (EVA), ethylene-methyl acrylate copolymer resin (EMA), ethylene-ethyl acrylate copolymer resin (EEA), etc. Examples of materials constituting the insulating layer include other materials such as fluorine-based resins.

[0031] In the case of an insulated wire used in an EPB cable, the thickness of the insulating layer is preferably 0.2 mm or more and 0.8 mm or less, and more preferably 0.25 mm or more and 0.7 mm or less. Here, "thickness of the insulating layer" means the shortest distance from the inner wall of the insulating layer to the outer wall of the insulating layer. The thickness of the insulating layer can be determined as follows. First, the thickness of each of 10 arbitrarily selected points on the insulating layer is measured using a vernier caliper or a micrometer. Next, the thicknesses measured at each point are averaged to obtain the thickness of the insulating layer.

[0032] The outer diameter of the insulated wire is preferably 2.5 mm or more and 4 mm or less, and more preferably 2.5 mm or more and 3.8 mm or less. The outer diameter of the insulated wire can be measured, for example, with a vernier caliper.

[0033] <Tape material> The tape member covers the core electric wire. In one aspect of the present embodiment, the tape member can be understood as being disposed between the core electric wire and a covering layer to be described later. The tape member can also be understood as being wound around the outer periphery of the core electric wire (the outer periphery of the assembly of insulated electric wires).

[0034] The tape member has a minimum transmittance of 70% or more in the wavelength range of 400 nm or more and 800 nm or less. In one aspect of this embodiment, it can also be understood that the tape member has a minimum transmittance of 70% or more for light in the wavelength range of 400 nm or more and 800 nm or less. In this way, the tape member transmits light in a predetermined wavelength range. As a result, even if the core electric wire is covered with the tape member, the state of the insulated electric wire (core electric wire) inside can be visually confirmed.

[0035] The minimum transmittance of the tape member in the above wavelength range is preferably 70% or more and 100% or less, and more preferably 80% or more and 100% or less. The transmittance can be calculated by measuring the transmission spectrum in the above-mentioned predetermined wavelength range. For example, a UV-2450 (product name) manufactured by Shimadzu Corporation is used as a device for measuring the transmission spectrum.

[0036] The tape member is desired to have a strength sufficient to prevent breakage due to repeated bending. The tape member is usually wound around the outer periphery of the core wire, so in this case ease of winding is desired. The thickness, shape (width, etc.) and forming material of the tape member are preferably selected taking into consideration strength and ease of winding.

[0037] From the above viewpoints, examples of materials constituting the tape member include cellulose, polyethylene terephthalate, and polyethylene. That is, the tape member preferably contains at least one compound selected from the group consisting of cellulose, polyethylene terephthalate, and polyethylene. Among them, the tape member more preferably contains polyethylene terephthalate. Examples of tape members made of cellulose include cellophane.

[0038] In one aspect of this embodiment, it is preferable that the tape member has a minimum transmittance of 70% or more for light in the wavelength range of 400 nm or more and 800 nm or less, and that the tape member contains at least one compound selected from the group consisting of cellulose, polyethylene terephthalate, and polyethylene. Conventionally, the tape member has generally been made of paper, nonwoven fabric, or the like. When an electrical insulated cable is exposed to severe vibration conditions, the electrical insulated cable is required to have excellent bending resistance. However, when paper or nonwoven fabric is used as the tape member, the tape member tends to be easily damaged by repeatedly bending the electrical insulated cable. In the electrical insulated cable according to the present embodiment, by using a tape member having the above-mentioned configuration, it is possible to achieve both excellent visibility and strength that can suppress damage due to repeated bending. The above-mentioned electrical insulated cable having the above-mentioned tape member is preferably used as an in-vehicle electrical insulated cable exposed to severe vibration conditions, particularly as an electrical insulated cable for an electric parking brake or an electrical insulated cable for an anti-lock brake system.

[0039] The thickness of the tape member is preferably 3 μm or more and 200 μm or less. If the thickness is less than 3 μm, the tape member tends to stretch when wound around the outer periphery of the core wire. If the thickness is more than 200 μm, the rigidity of the tape member is high and the tape tends to spread even when wound, and the outer diameter of the coating layer coated after winding tends to become unstable. The thickness of the tape member can be measured, for example, by a micrometer having a cylindrical spindle with a flat tip and a diameter of 10 mm. At this time, the thickness is first measured at 10 arbitrarily selected points on the tape member, and the average value of the thicknesses obtained at each of the selected 10 points is taken as the thickness of the tape member.

[0040] In addition, when the core wire is covered with the tape member and then the covering layer is formed on the outer periphery of the tape member by melt extrusion of the resin that is the material of the covering layer, it is desirable that the tape member does not soften due to the heat of the melt extrusion. Therefore, it is preferable that the tape member is made of a material having a higher melting point than the melting point of the material that constitutes the covering layer. Specifically, it is preferable that the tape member is made of a material having a melting point of 160°C or higher, such as polyethylene terephthalate. If the melting point is lower than 160°C, the tape member may melt or deform during the process of forming the covering layer on the outer periphery of the tape member.

[0041] <Coating layer> The covering layer of the present disclosure covers the tape member. In one aspect of this embodiment, the covering layer can also be understood as covering the outer periphery of the core electric wires bundled by the tape member. The covering layer protects the core electric wires. That is, the covering layer is required to have resistance (impact resistance) against stone chipping and the like while the automobile is traveling, and flexibility to ensure the flexibility of the electrical insulated cable. The covering layer is also required to have excellent bending resistance and the like that does not cause deterioration such as breakage of the conductor and increase in resistance due to repeated bending during traveling. In one aspect of this embodiment, the covering layer may or may not be transparent to visible light.

[0042] The covering layer may be composed of a single layer (see, for example, FIG. 3). In this case, the material constituting the covering layer may be either the material constituting the first sheath layer described below or the material constituting the second sheath layer described below.

[0043] The covering layer may be composed of two or more layers. That is, the covering layer preferably includes a first sheath layer covering the tape member and a second sheath layer covering the first sheath layer. For example, an electrically insulated cable mounted on a vehicle, such as an EPB cable or an ABS cable, may have a two-layer structure in which the covering layer is composed of a first sheath layer covering the tape member (core wire) and a second sheath layer covering the first sheath layer (see Figs. 1 and 2).

[0044] (First sheath layer) In order to improve the flexibility of the electrical insulated cable, a material having excellent flexibility is preferable as a material constituting the first sheath layer. In particular, when the first sheath layer has a large elastic modulus in a low-temperature environment, the bending resistance of the electrical insulated cable in a low-temperature environment tends to decrease. Therefore, in order to improve the bending resistance of the electrical insulated cable in a low-temperature environment, a material that is flexible in a low-temperature environment is preferably used as the material of the first sheath layer. In the case of an electrical insulated cable to be mounted on a vehicle, the material of the first sheath layer is also desired to have excellent abrasion resistance, excellent heat resistance, etc., and in many cases, flame retardancy is also desired.

[0045] Examples of materials constituting the first sheath layer include polyolefin-based resins such as polyethylene and ethylene-vinyl acetate copolymer (EVA), polyurethane elastomers, polyester elastomers, and resins made by mixing these. By forming the first sheath layer from a polyolefin-based resin, the flexibility of the electrical insulated cable in a low-temperature environment can be improved, and bending resistance can be improved. By forming the first sheath layer from a polyurethane elastomer, the abrasion resistance of the electrical insulated cable can be improved. Furthermore, by forming the first sheath layer from a polyester elastomer, the heat resistance of the electrical insulated cable can be improved. Among the above-mentioned resins, polyethylene-based resins are particularly preferable from the viewpoint of manufacturing costs, etc.

[0046] The material constituting the first sheath layer may be a resin mainly composed of very low density polyethylene (VLDPE) and having a small ratio of elastic modulus in a low temperature environment to that in a high temperature environment. By using such a resin, an electrical insulated cable having excellent bending resistance in a wide temperature range from room temperature to low temperatures can be manufactured. The resin mainly composed of VLDPE may be blended with other resins such as EVA, ethylene-ethyl acrylate copolymer resin (EEA), and acid-modified VLDPE, as long as the effects of the present disclosure are achieved. As long as the effects of the present disclosure are achieved, the material forming the first sheath layer may contain various additives such as an antioxidant, a colorant, and a flame retardant.

[0047] When the electrically insulated cable is a power line used for power supply (e.g., a cable for EPB), the thickness of the first sheath layer is usually preferably 0.3 mm or more and 1.5 mm or less, and more preferably 0.45 mm or more and 1.2 mm or less. Here, the "thickness of the first sheath layer" means the shortest distance from the inner wall of the first sheath layer to the outer wall of the first sheath layer. The thickness of the first sheath layer can be measured using a caliper or a micrometer in the same manner as described above (average value of 10 points).

[0048] (Second sheath layer) The second sheath layer covers the first sheath layer. In one aspect of this embodiment, the second sheath layer can be understood as the outermost sheath layer of the electrical insulated cable. An electrical insulated cable (such as an EPB cable) mounted on a vehicle is susceptible to damage caused by stones flying while the vehicle is traveling. In order to suppress such damage, a resin having excellent resistance to external damage and abrasion is desired as the material constituting the second sheath layer. In addition, in order to make the electrical insulated cable flexible, a material having excellent flexibility is desired as the material for the second sheath layer. Furthermore, when flame retardancy is desired for the electrical insulated cable, high flame retardancy is desired for the second sheath layer. Therefore, from the viewpoints of resistance to external damage, flexibility, etc., polyurethane-based resins are preferably used as materials for forming the second sheath layer, and for example, flame-retardant polyurethane resins are preferably used.

[0049] When the electrically insulated cable is a power line used for power supply (e.g., a cable for EPB), the thickness of the second sheath layer is usually preferably 0.3 mm or more and 0.7 mm or less. Here, the "thickness of the second sheath layer" means the shortest distance from the inner wall of the second sheath layer to the outer wall of the second sheath layer. The thickness of the second sheath layer can be measured using a caliper or a micrometer in the same manner as described above (average value of 10 points).

[0050] <Embodiment of Electrically Insulated Cable of the Present Disclosure> More specific embodiments of the above-mentioned electrical insulated cable will be described below. (Embodiment 1) Fig. 1 is a cross-sectional view of a first embodiment of an electrically insulated cable according to the present disclosure. An electrically insulated cable 50 shown in Fig. 1 is an electrically insulated cable used as an EPB cable. The electrically insulated cable 50 has a core electric wire 14 formed by twisting together two insulated electric wires 13. The covering layer 18 covering the core electric wire 14 is made up of a first sheath layer 16 and a second sheath layer 17.

[0051] In FIG. 1, the insulated wire 13 is composed of a conductor 11 and an insulating layer 12 covering the conductor 11. The conductor 11 is made of a copper alloy, and is a twisted wire (total of 504 wires) made by twisting 72 strands of wires each having an outer diameter of 0.08 mm together and twisting these strands together. The outer diameter of the conductor 11 is about 2.4 mm. The outer circumference of the conductor 11 is covered with an insulating layer 12 made of flame-retardant polyethylene. The insulating layer 12 is about 0.5 mm thick. Two insulated wires 13 thus formed are twisted together to form a core wire 14.

[0052] The tape member 15 is wound in a spiral shape around the outer periphery of the core electric wire 14, covering the entire outer periphery of the core electric wire 14. The tape member 15 has a minimum transmittance of 70% or more for light having a wavelength in the range of 400 nm to 800 nm. The tape member 15 is a transparent tape having a width of about 5 mm and a thickness of about 0.033 mm. Polyethylene terephthalate is used as the tape member 15. The tape member 15 has flexibility that allows easy winding, and has strength that makes it difficult to break due to bending of the electrical insulation cable, etc. In addition, the tape member 15 is preferably made of a material that does not soften due to heat when forming the coating layer 18 (melt extrusion of resin).

[0053] The first sheath layer 16 is made of polyethylene. The first sheath layer 16 has a thickness of about 0.6 mm. The second sheath layer 17 is made of polyurethane. The second sheath layer 17 has a thickness of about 0.5 mm. The material constituting the first sheath layer 16 is not limited to polyethylene, but a resin that improves the flame retardancy, abrasion resistance, and bending resistance (flexibility) of the electrical insulated cable is preferably used. The material constituting the second sheath layer 17 is not limited to polyurethane, but a resin that is excellent in flame retardancy, external damage resistance, and bending resistance (flexibility) is preferably used. The outer diameter of the electrical insulated cable 50 is about 8 mm to 9 mm.

[0054] (Embodiment 2) Fig. 2 is a cross-sectional view of another example of an embodiment of an electrically insulated cable according to the present disclosure. An electrically insulated cable 60 shown in Fig. 2 is an electrically insulated cable used for EPB and ABS. The electrically insulated cable 60 has a core wire 24 formed by twisting together four insulated wires (two insulated wires 23a and two insulated wires 23b). The covering layer 28 covering the core wire 24 is made up of a first sheath layer 26 and a second sheath layer 27.

[0055] In FIG. 2, the insulated wire 23a is composed of a conductor 21a and an insulating layer 22a that covers the conductor 21a. The conductor 21a is made of a copper alloy, and is a stranded wire formed by twisting 72 strands of wires each having an outer diameter of 0.08 mm, and twisting these strands together to form a twisted wire (a total of 504 strands). The outer diameter of the conductor 21a is about 2.4 mm. The outer circumference of the conductor 21a is covered with an insulating layer 22a made of flame-retardant polyethylene and having a thickness of about 0.5 mm. The insulated wire 23a transmits power for the EPB. On the other hand, the insulated wire 23b is composed of a conductor 21b and an insulating layer 22b that covers the conductor 21b. The conductor 21b is a stranded wire formed by twisting 48 strands of wires each having an outer diameter of about 0.08 mm, each made of a copper alloy. The outer diameter of the conductor 21b is about 0.7 mm. The outer circumference of the conductor 21b is covered with an insulating layer 22b made of flame-retardant polyethylene and having a thickness of about 0.4 mm. The insulated electric wire 23b transmits power for the ABS. The two insulated electric wires 23a and the two insulated electric wires 23b thus formed are twisted together to form the core electric wire 24.

[0056] The tape member 25 is wound in a spiral shape around the outer periphery of the core electric wire 24, covering the entire outer periphery of the core electric wire 24. The tape member 25 has a minimum transmittance of 70% or more for light with a wavelength in the range of 400 nm to 800 nm. The tape member 25 can be a tape with the same width and thickness as the tape member 15 in the first embodiment. The tape member 25 can also be made of the same material as the tape member 15.

[0057] The first sheath layer 26 may have a thickness similar to that of the first sheath layer 16 in the first embodiment. The first sheath layer 26 may be made of a material similar to that of the first sheath layer 16. The second sheath layer 27 may have a thickness similar to that of the second sheath layer 17 in the first embodiment. The second sheath layer 27 may be made of a material similar to that of the second sheath layer 17. The outer diameter of the insulated cable 60 is about 8 mm to 9 mm.

[0058] The electrically insulated cable according to the present embodiment has been described above in detail. The electrically insulated cable is used as a member for making electrical connections in various devices. The electrically insulated cable is suitably used as an electrically insulated cable for vehicles, particularly as a cable used for applications such as an electric parking brake (EPB) mechanism and an antilock braking system (ABS) of a vehicle. That is, the electrically insulated cable is preferably an electrically insulated cable for an electric parking brake. Furthermore, the electrically insulated cable is preferably an electrically insulated cable for an antilock braking system.

[0059] Furthermore, by forming a covering layer of a transparent resin, the above-mentioned electrically insulated cable is also suitable as a model cable for evaluating characteristics to be used in the development stage. By using the electrically insulated cable according to the present disclosure as a model cable, it becomes easy to observe the behavior and state of the inside of the cable when it is bent or stretched.

[0060] <Manufacturing method of electrical insulated cable> Next, a method for manufacturing the electrical insulated cable of the present disclosure will be described. Fig. 4 is a schematic diagram showing a manufacturing apparatus for manufacturing the electrical insulated cable according to one aspect of the present embodiment. As shown in Fig. 4, the manufacturing apparatus 111 includes two insulated wire supply reels 112, a twisting unit 113, a tape member supply reel 114, a tape member winding unit 115, a first sheath layer covering unit 116, a second sheath layer covering unit 117, a cooling unit 118, and an electrical insulated cable winding reel 119.

[0061] An insulated wire 13 is wound around each of the two insulated wire supply reels 112, and the two insulated wires 13 are supplied to the twisting section 113. Here, the insulated wire 13 can be manufactured by covering the outer periphery of the conductor 11 as described above with an insulating resin (hereinafter sometimes referred to as "insulating resin") which is a material constituting the insulating layer 12. Covering with insulating resin can be performed by the same method as in the case of manufacturing known insulated wires, for example, melt extrusion of insulating resin. After the insulating layer is formed, the resin forming the insulating layer may be crosslinked by irradiation with ionizing radiation or the like in order to improve the heat resistance of the insulating layer.

[0062] In the twisting section 113, the two insulated electric wires 13 that have been supplied are twisted together to form a core electric wire 14. This core electric wire 14 is sent to a tape member winding section 115.

[0063] In the tape member winding section 115, the core electric wire 14 sent from the twisting section 113 and the tape member 15 supplied from the tape member supply reel 114 join together, and the tape member 15 is spirally wound around the outer periphery of the core electric wire 14 to form a tape-attached core electric wire 34. This tape-attached core electric wire 34 is sent to the first sheath layer covering section 116. Here, an imaging device 200 may be disposed between the tape member winding section 115 and the first sheath layer covering section 116. Since the tape member 15 is transparent to light of a predetermined wavelength, it becomes possible to observe the state of the insulated electric wire 13 in the tape-attached core electric wire 34 by the imaging device 200.

[0064] The first sheath layer covering section 116 is connected to a storage section 116a in which a resin material such as a polyolefin resin is stored. In the first sheath layer covering section 116, the resin material supplied from the storage section 116a is extruded onto the outer periphery of the tape-attached core electric wire 34 to cover it. In this manner, the first sheath layer 16 is formed so as to cover the outer periphery of the tape-attached core electric wire 34. The tape-attached core electric wire 35 covered with the first sheath layer 16 is sent to the second sheath layer covering section 117.

[0065] The second sheath layer covering portion 117 is connected to a storage portion 117a in which a resin material such as a polyurethane resin is stored. In the second sheath layer covering portion 117, the resin material supplied from the storage portion 117a is extruded and coated on the outer periphery of the first sheath layer 16 formed by the first sheath layer covering portion 116. In this manner, the second sheath layer 17 is formed so as to cover the outer periphery of the first sheath layer 16, and an electrically insulated cable 50 is formed in which a two-layered covering layer 18 consisting of the first sheath layer 16 and the second sheath layer 17 is covered. After the second sheath layer 17 is formed, the electrically insulated cable 50 may be irradiated with an electron beam or the like in order to crosslink the resin of the covering layer 18 and improve scratch resistance or the like. The electrically insulated cable 50 is sent to a cooling portion 118 where the covering layer 18 is cooled and hardened, and then sent to a cable winding reel 119 and wound.

[0066] The above description includes the following additional features. (Appendix 1) A core wire, A tape member covering the core wire; and a coating layer coating the tape member, The core wire includes a plurality of insulated wires, The insulated wire includes a conductor and an insulating layer covering the conductor, The tape member is an insulated cable, the minimum transmittance of which is 70% or more in a wavelength range of 400 nm or more and 800 nm or less. (Appendix 2) 2. The electrical insulated cable of claim 1, wherein the tape member contains at least one compound selected from the group consisting of cellulose, polyethylene terephthalate, and polyethylene. (Appendix 3) 3. The electrical insulated cable according to claim 1 or 2, wherein the tape member has a thickness of 3 μm or more and 200 μm or less. (Appendix 4) 4. The electric insulated cable according to any one of Appendix 1 to Appendix 3, wherein the covering layer includes a first sheath layer covering the tape member and a second sheath layer covering the first sheath layer. (Appendix 5) Each of the insulated wires has the same diameter as the others, The cross-sectional area of ​​the conductor in the plurality of insulated wires is 1.5 mm 2 More than 3mm 2 5. An electrical insulated cable according to any one of Supplementary Note 1 to Supplementary Note 4, wherein: EXAMPLES

[0067] The present disclosure will be specifically described below based on examples, but the present invention is not limited to the following examples.

[0068] <Manufacturing of electrical insulated cables> <Material preparation> To prepare an insulated electrical cable, the following materials were prepared: 1) Insulation layer material: flame-retardant polyethylene resin (manufactured by Riken Technos Corporation, product name: ANQ9729T) 2) Material forming the first sheath layer: non-flame retardant polyethylene resin (manufactured by Mitsui DuPont Polychemicals Co., Ltd., product name: Evaflex EV360) 3) Material for forming the second sheath layer: non-flame retardant polyurethane resin (manufactured by BASF, product name: Elastollan ET385) 4) Tape member forming material Cellophane: 20μm thick (manufactured by Rengo Co., Ltd.) PET tape: 14μm or 30μm thick (Lumirror, manufactured by Toray Industries, Inc.) PE tape: 50μm thick (manufactured by Futamura Chemical Co., Ltd.) Tape A: Polyester paper 9g / m made by Daio Paper Co., Ltd. 2 Tape B: Daio Paper Corporation Rayon paper 11g / m 2 Tape C: Daio Paper Co., Ltd. Rayon paper 25g / m 2

[0069] <Measurement of transmittance of tape material> The transmission spectrum of the above-mentioned tape member was measured in the wavelength range of 400 nm or more and 800 nm or less using UV-2450 manufactured by Shimadzu Corporation, and the minimum value of the transmittance was determined.

[0070] <Production of Electrically Insulated Cable> A wire made of a copper alloy and having an outer diameter of 0.08 mm was prepared. 52 of the wires were twisted together to prepare a stranded wire. Seven of the twisted wires were twisted together to prepare a conductor (stranded wire). The outer diameter of the conductor was 2.0 mm. A flame-retardant polyethylene resin was melt-extruded around the outer circumference of the conductor to form an insulating layer having a thickness of 0.4 mm to prepare an insulated wire.

[0071] Two of the prepared insulated electric wires were twisted together to prepare a core electric wire. Each of the tape members shown in Table 1 was wound in a spiral shape in one layer with a winding width of 3 mm around the outer periphery of the prepared core electric wire, and the outer periphery of the core electric wire was covered with the tape member. A non-flame retardant polyethylene-based resin was melt-extruded to cover the outer periphery of the core electric wire around which the tape member was wound, to form a first sheath layer having a thickness of 0.5 mm. Then, a non-flame retardant polyurethane-based resin was melt-extruded to cover the outer periphery of the first sheath layer, to form a second sheath layer having a thickness of 0.5 mm. Samples of electrical insulated cables having sample numbers 1 to 7 were prepared by the above procedure. Here, sample numbers 1 to 4 correspond to examples. Sample numbers 5 to 7 correspond to comparative examples.

[0072] <Visibility test> A visibility test was carried out for sample numbers 1 to 7 in the following manner. That is, using an assembly wire covered with a tape member, it was confirmed whether the state of the internal insulation (presence or absence of lumps in the insulating layer, presence or absence of foreign matter, disorder of the assembly twist, etc.) could be visually confirmed. When the internal insulation state could be visually confirmed, it was given an A rating, and when it could not be visually confirmed, it was given a B rating. The results are shown in Table 1.

[0073] [Table 1]

[0074] The results in Table 1 show that the insulated cables of sample numbers 1 to 4 have excellent visibility of the insulated electric wire inside even when the core electric wire is covered with a tape member.

[0075] The embodiments and examples disclosed herein are illustrative in all respects and should not be considered as limiting. The scope of the present invention is indicated by the claims, not by the embodiments and examples described above, and is intended to include the meaning equivalent to the claims and all modifications within the scope. [Explanation of symbols]

[0076] 11, 21a, 21b conductor, 12, 22a, 22b insulating layer, 13, 23a, 23b insulated electric wire, 14, 24 core electric wire, 15, 25 tape member, 16, 26 first sheath layer, 17, 27 second sheath layer, 18, 28 coating layer, 34 core electric wire with tape, 35 core electric wire with tape coated with first sheath layer, 50, 60 electric insulated cable, 111 manufacturing device, 112 insulated electric wire supply reel, 113 twisting unit, 114 tape member supply reel, 115 tape member winding unit, 116 first sheath layer coating unit, 117 second sheath layer coating unit, 116a, 117a storage unit, 118 cooling unit, 119 electric insulated cable winding reel, 200 imaging device

Claims

1. A core wire, A tape member covering the core wire; and a coating layer coating the tape member, The core wire includes a plurality of insulated wires, The insulated wire includes a conductor and an insulating layer covering the conductor, the electrically insulated cable does not include optical fibers; The insulated wires each have the same diameter as each other, The cross-sectional area of ​​the conductor in the plurality of insulated wires is 1.5 mm ２ 3mm or more ２ is as follows: The tape member has a minimum transmittance of 70% or more for light having a wavelength in the range of 400 nm or more and 800 nm or less.

2. 2. The electrical insulated cable of claim 1, wherein the tape member comprises at least one compound selected from the group consisting of cellulose, polyethylene terephthalate, and polyethylene.

3. 3. The electrical insulated cable according to claim 1, wherein the tape member has a thickness of 3 μm or more and 200 μm or less.

4. 4. The electric insulated cable according to claim 1, wherein the covering layer includes a first sheath layer covering the tape member and a second sheath layer covering the first sheath layer.

5. The electric insulated cable according to claim 1 , which is an electric insulated cable for use in a vehicle.

6. 6. The electrically insulated cable according to claim 5, which is an electrically insulated cable for an electric parking brake.

7. 6. The electrically insulated cable of claim 5, which is an electrically insulated cable for an anti-lock braking system.

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