Multicore cable

Abstract

To provide a multicore cable in which the outer diameter is reduced and the welding of the coated electric wires included therein is suppressed.SOLUTION: A multicore cable includes a core formed by twisting a plurality of coated electric wires; and an outer sheath disposed outside the core. The thickness of the outer sheath is 0.03 mm or less. Each of the plurality of coated electric wires includes a conductor and an insulator covering the conductor. The thickness of the insulator is 5 μm or less. The insulator contains one or more selected from polyimide and polyamide-imide as a resin material.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to multi-conductor cables. [Background technology]

[0002] Patent Document 1 discloses a multi-core cable including a cable core formed by twisting together a number of electric wires, a pressure winding tape wound around the cable core, a shielding member provided on the outer periphery of the pressure winding tape, and a jacket covering the outside of the shielding member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-046647 A Summary of the Invention [Problem to be solved by the invention]

[0004] 2. Description of the Related Art Multi-core cables in which a plurality of electric wires or the like are integrated have conventionally been used for various purposes.

[0005] In recent years, devices or tubes equipped with multi-core cables are being inserted into living bodies for the purpose of examination, treatment, etc. Multi-core cables used in living bodies are required to have a small outer diameter in order to reduce the load on the living body.

[0006] However, if the thickness of the coating of the insulated electric wires included in the multi-core cable is reduced in order to reduce the outer diameter of the multi-core cable, the heat generated when forming the outer sheath of the multi-core cable can melt the coating of the insulated electric wires included in the multi-core cable, causing the insulated electric wires to weld together.

[0007] Therefore, an object of the present disclosure is to provide a multi-core cable that has a reduced outer diameter and suppresses welding of the contained covered electric wires. [Means for solving the problem]

[0008] The multi-core cable of the present disclosure includes a core formed by twisting together a plurality of covered electric wires; and an outer jacket disposed outside the core. The thickness of the outer jacket is 0.03 mm or less, The coated electric wire has a conductor and an insulator covering the conductor, The thickness of the insulator is 5 μm or less, The insulator contains at least one type of resin selected from polyimide and polyamideimide. Effect of the Invention

[0009] According to the present disclosure, it is possible to provide a multi-core cable having a reduced outer diameter and suppressing welding of the contained covered electric wires. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view of a multi-core cable according to one embodiment of the present disclosure taken along a plane perpendicular to the longitudinal direction. [Diagram 2] FIG. 2 is a cross-sectional view of a multi-core cable according to one embodiment of the present disclosure taken along a plane perpendicular to the longitudinal direction. [Diagram 3] FIG. 3 is a cross-sectional view of a covered electric wire in a multi-core cable according to one embodiment of the present disclosure, taken along a plane perpendicular to the longitudinal direction thereof. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The embodiments for carrying out the invention are described below.

[0012] [Description of the embodiments of the present disclosure] First, the embodiments of the present disclosure will be described. In the following description, the same or corresponding elements are denoted by the same reference numerals, and the same description thereof will not be repeated.

[0013] (1) A multi-core cable according to one embodiment of the present disclosure includes: a core formed by twisting together a plurality of covered electric wires; and an outer jacket disposed outside the core. The thickness of the outer jacket is 0.03 mm or less, The coated electric wire has a conductor and an insulator covering the conductor, The thickness of the insulator is 5 μm or less, The insulator contains at least one type of resin selected from polyimide and polyamideimide.

[0014] By keeping the thickness of the outer sheath to 0.03 mm or less, the outer diameter of the multi-core cable can also be reduced.

[0015] By including at least one resin selected from polyimide and polyamide-imide in the insulator, the melting point of the insulator can be increased, and the insulator can be prevented from melting due to the heat generated when forming the jacket, thereby preventing the coated electric wires of the multi-core cable according to one embodiment of the present disclosure from welding to each other.

[0016] By setting the thickness of the insulation to 5 μm or less, the outer diameter of the insulated wire can be reduced, and the outer diameter of the multi-core cable including the insulated wire can also be reduced.

[0017] (2) In (1), the outer diameter of the conductor may be 0.032 mm or less.

[0018] By setting the outer diameter of the conductor to 0.032 mm or less, the outer diameter of the multi-core cable can be particularly reduced.

[0019] (3) In (1) or (2), the conductor may have a central portion containing iron and an outer periphery containing copper arranged outside the central portion.

[0020] By having a central portion containing iron, the strength of the conductor can be increased, the outer diameter of the conductor can be reduced, and breakage can be suppressed even when the conductor is repeatedly bent.

[0021] Furthermore, by having a conductor with an outer periphery containing copper, the electrical characteristics of the conductor can be improved.

[0022] (4) In any of (1) to (3), a metal shield layer may be provided between the core and the jacket.

[0023] The metal shield layer can suppress noise from being carried on the signal transmitted through the covered electric wire, and can also suppress the influence of noise on external devices.

[0024] [Details of the embodiment of the present disclosure] Specific examples of a multi-core cable according to an embodiment of the present disclosure (hereinafter, referred to as the present embodiment) will be described below with reference to the drawings. Note that the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0025] In this specification, there are cases where the names of components are described with suffixes such as first, second, third, etc., added to the names, such as a first covered electric wire, a second covered electric wire, and a third covered electric wire. The suffixes such as first, second, third, etc., are merely used to distinguish the components and to prevent confusion during description, and do not represent arrangement, priority, etc. For this reason, when there is no particular risk of confusion or when the components are described together, they may simply be written as covered electric wires. [Multi-core cable] Fig. 1 shows an example of the configuration of a cross section perpendicular to the longitudinal direction of a multi-core cable 10 of this embodiment. Fig. 2 shows another example of the configuration of a cross section perpendicular to the longitudinal direction of a multi-core cable 20 of this embodiment. Fig. 3 shows an example of the configuration of a cross section perpendicular to the longitudinal direction of a covered electric wire 11.

[0026] Since FIG. 2 corresponds to a modified example of the multi-core cable of the present embodiment, the following description will be given mainly with reference to FIG. 1 and FIG. 3, and with reference to FIG. 2 as necessary.

[0027] As shown in FIG. 1, a multi-core cable 10 of this embodiment has a core 100 in which a plurality of covered electric wires 11 are twisted together, and an outer sheath 12 disposed on the outside of the core 100.

[0028] Each member contained in the multi-core cable of this embodiment will be described below. (1) Core (1-1) Configuration of the coated wire in the core The configuration of the covered electric wire 11 in the core 100 is not particularly limited.

[0029] For example, as shown in FIG. 1, the core 100 may have a configuration in which a plurality of first coated electric wires 11A having the same outer diameter and made of the same material are twisted together.

[0030] 2, the core 200 may have a configuration in which a plurality of covered electric wires having different configurations such as outer diameters are twisted together, such as a first covered electric wire 11A, a second covered electric wire 11B, and a third covered electric wire 11C. As in the third covered electric wire 11C in the core 200 shown in FIG. 2, two covered electric wires may be twisted together to form a twisted pair electric wire 110, and then twisted with another covered electric wire 11 to form the core 200.

[0031] The configurations of the core and the covered electric wires of the multi-core cable of the present embodiment are not limited to those shown in Fig. 1 and Fig. 2. The core of the covered electric wire of the present embodiment can be configured by combining and twisting any number of covered electric wires selected according to the application.

[0032] The core 100 can also be formed by twisting a plurality of covered electric wires 11 together. That is, the core 100 can be formed by arranging the covered electric wires 11 in a plurality of layers from the center of the core 100, and twisting the covered electric wires 11 together at the same twisting pitch, instead of twisting the covered electric wires 11 in each layer. By twisting a plurality of covered electric wires 11 together, the multi-core cable 10 can make the covered electric wires 11 contained therein less likely to break even when the multi-core cable 10 is repeatedly bent. (1-2) Insulated wires As shown in FIG. 1 and FIG. 3, the coated electric wire 11 has a conductor 111 and an insulator 112 that covers the conductor 111 . (conductor) The outer diameter D111 of the conductor 111 (see FIG. 3) can be selected according to the application and is not particularly limited. However, from the viewpoint of particularly reducing the outer diameter D10 of the multi-core cable 10, the outer diameter D111 of the conductor 111 can also be reduced.

[0033] Therefore, for example, the outer diameter D111 of the conductor 111 can be set to 0.060 mm or less. By setting the outer diameter D111 of the conductor 111 to 0.060 mm or less, the outer diameter D10 of the multi-core cable 10 can also be reduced.

[0034] The outer diameter D111 of the conductor 111 may be equal to or less than 0.032 mm. By setting the outer diameter D111 of the conductor 111 to equal to or less than 0.032 mm, the outer diameter D10 of the multi-core cable 10 can be particularly suppressed.

[0035] The lower limit of the outer diameter D111 of the conductor 111 is not particularly limited, but may be, for example, 0.02 mm or more. That is, the outer diameter D111 of the conductor 111 may be, for example, 0.02 mm or more and 0.060 mm or less, or 0.02 mm or more and 0.032 mm or less.

[0036] The outer diameter D111 of the conductor 111 can be calculated by measuring two perpendicular diameters in a cross section perpendicular to the longitudinal direction of the covered electric wire 11 and averaging the measured diameters. The outer diameter D11 of the covered electric wire 11, the outer diameter D10 of the multi-core cable 10, and the outer diameter D100 of the core 100 can also be measured and calculated in the same manner, except that the evaluation targets are changed to the covered electric wire 11, the multi-core cable 10, and the core 100.

[0037] 2, when the covered electric wire 11 includes conductors 111 of different sizes, for example, the outer diameters D111 of the conductors 111 of at least some of the covered electric wires 11 may be configured to satisfy the above range. The outer diameters D111 of the conductors 111 of all of the covered electric wires 11 may be configured to satisfy the above range.

[0038] The conductor 111 may be a single conductor wire or may have multiple conductor wires. When the conductor has multiple conductor wires, the multiple conductor wires may be twisted together. In other words, when the conductor has multiple conductor wires, the conductor may be a twisted wire of multiple conductor wires.

[0039] The material of the conductor 111 is not particularly limited, but may be, for example, a copper alloy or copper. As the copper, for example, soft copper may be used. The copper may be plated with tin or silver. In terms of electrical conductivity and tensile strength, a silver-copper alloy may also be used.

[0040] In the coated electric wire 11 included in the multi-core cable 10 of the present embodiment, the outer diameter D111 of the conductor 111 can be reduced. However, if the outer diameter D111 of the conductor 111 is reduced, the conductor 111 becomes more susceptible to breakage when repeatedly bent.

[0041] Therefore, as shown in FIG. 3, when a strength greater than that of a copper alloy wire is required, the conductor 111 of the coated electric wire 11 can have a central portion 31 containing iron and an outer peripheral portion 32 containing copper and arranged outside the central portion 31.

[0042] Conductor 111 has core 31 containing iron, which increases the strength of conductor 111, reduces the outer diameter D111 of conductor 111, and prevents breakage even when conductor 111 is repeatedly bent.

[0043] Furthermore, since the conductor 111 has the outer periphery 32 containing copper, the electrical characteristics of the conductor 111 can be maintained excellent.

[0044] The iron-containing material used for the central portion 31 may be, for example, stainless steel such as SUS316L.

[0045] Examples of the copper-containing material used for the outer periphery 32 include soft copper and copper alloys.

[0046] The conductor 111 having the central portion 31 and the outer peripheral portion 32 can be manufactured by wiredrawing a base material, for example, stainless steel with a copper-plated surface. Fig. 3 shows a schematic example in which the central portion 31 and the outer peripheral portion 32 are arranged concentrically, but the present invention is not limited to this form. (Insulator) The insulator 112 may contain, as a resin, one or more selected from polyimide and polyamideimide.

[0047] By including one or more resins selected from polyimide and polyamide-imide in insulator 112, the melting point of insulator 112 can be increased, and insulator 112 can be prevented from melting due to heat generated when molding jacket 12. This makes it possible to prevent coated electric wires 11 of multi-core cable 10 of the present embodiment from welding to each other.

[0048] The insulator 112 can be manufactured, for example, by baking the above-mentioned resin onto the surface of the conductor 111. Therefore, the insulator 112 can be made only of the above-mentioned resin.

[0049] The thickness T112 of the insulator 112 is not particularly limited, but may be, for example, 5 μm or less. By setting the thickness T112 of the insulator 112 to 5 μm or less, the outer diameter D11 of the coated electric wire 11 can be reduced, and the outer diameter D10 of the multi-core cable 10 including the coated electric wire 11 can also be reduced.

[0050] The lower limit of the thickness T112 of the insulator 112 is not particularly limited, but may be, for example, 2 μm or more. That is, the thickness T112 of the insulator 112 may be, for example, 2 μm or more and 5 μm or less.

[0051] The thickness T112 of the insulator 112 can be calculated by subtracting the outer diameter D111 of the conductor 111 from the outer diameter D11 of the coated wire 11 and dividing the result by two. (2) Outer covering The jacket 12 may be disposed over the core 100 .

[0052] The multi-core cable 10 has an outer sheath 12, which can protect the covered electric wires 11 and the like arranged inside.

[0053] The outer cover 12 may contain fluororesin as the resin material.

[0054] By including fluororesin as the resin material in the outer jacket 12, sufficient strength can be ensured even if the thickness T12 of the outer jacket 12 is reduced.

[0055] As the fluororesin, for example, one or more types selected from polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer (ETFE), etc. can be used.

[0056] The resin material contained in the jacket 12 may be crosslinked or may not be crosslinked.

[0057] The outer jacket 12 can be composed only of the above-mentioned resin material, but the outer jacket 12 can also contain, in addition to the resin material, one or more additives selected from a flame retardant, a flame retardant assistant, an antioxidant, a lubricant, a colorant, a reflectivity imparting agent, a masking agent, a processing stabilizer, a plasticizer, and the like.

[0058] The thickness T12 of the outer sheath 12 can be set to 0.03 mm or less. By setting the thickness T12 of the outer sheath 12 to 0.03 mm or less, the outer diameter D10 of the multi-core cable 10 can also be reduced.

[0059] The lower limit of the thickness T12 of the outer jacket 12 is not particularly limited, but may be, for example, 0.01 mm or more. That is, the thickness T12 of the outer jacket 12 may be, for example, 0.01 mm or more and 0.03 mm or less.

[0060] The thickness T12 of the jacket 12 can be calculated by subtracting the outer diameter D100 of the core 100 from the outer diameter D10 of the multi-core cable 10 and dividing the result by two. (3) Other materials The multi-core cable of this embodiment may have any optional members other than the core 100 and the jacket 12 .

[0061] For example, as shown in FIG. 2, the multi-conductor cable 20 may include a metallic shield layer 22 between the core 100 and the jacket 12 . (3-1) Metal shield layer The metal shield layer 22 can suppress noise from being carried in a signal propagated through the covered electric wire 11. In addition, the metal shield layer 22 can suppress the influence of noise on external devices.

[0062] The metal shield layer 22 may include a conductive material.

[0063] For example, the metal shield layer 22 may be formed by spirally wrapping a conductive tape including a conductive layer along the length of the core 200 .

[0064] In this case, the conductive tape may be composed of only a conductive layer, or may have a conductive layer disposed on one or more surfaces selected from the upper and lower surfaces of a substrate.

[0065] The material of the conductive layer is not particularly limited, but may include, for example, a metal, such as a metal foil. When the conductive layer includes a metal, the metal material is not particularly limited, but may include, for example, copper, a copper alloy, aluminum, an aluminum alloy, etc.

[0066] The material of the substrate is not particularly limited, and may be, for example, an insulating material such as an organic polymer material or a nonwoven fabric. Examples of the organic polymer material include polyester resins such as polyethylene terephthalate (PET), polyolefin resins such as polypropylene, and vinyl resins such as polyvinyl chloride. The substrate may contain an insulating material, or may be made of only an insulating material.

[0067] When the metal shield layer 22 is formed by winding a conductive tape, the winding direction of the conductive tape can be selected arbitrarily. For example, the winding direction may be the same as the twisting direction of the core 200, or may be a different direction.

[0068] The metal shield layer 22 can also be formed of metal wires. In this case, the metal shield layer 22 can be formed by arranging the metal wires in a braided structure or a spirally wound structure.

[0069] The material of the metal wire may be copper, aluminum, a copper alloy, etc. The surface of the metal wire may be plated with silver or tin. Therefore, the metal wire may be made of, for example, a silver-plated copper alloy or a tin-plated copper alloy. (3-2) Holder roll As shown in FIG. 2, the multi-core cable 20 may also have a pressure wrap 21 covering the outer surface of the core 200 .

[0070] The pressure winding 21 can stabilize the arrangement of the covered electric wires 11 of the multi-core cable 20 and bundle them.

[0071] The retainer roll 21 may be, for example, a resin tape.

[0072] Examples of resins used in the resin tape include one or more types selected from fluororesins such as polytetrafluoroethylene (PTFE) resin, which have excellent heat resistance and abrasion resistance, polyester resins such as polyethylene terephthalate (PET) resin, and polyethylene (PE).

[0073] The resin tape used as the pressure roll 21 may contain a conductive material such as carbon to provide electrical conductivity. The conductive material may be added so as to be dispersed in the resin constituting the resin tape. Alternatively, a metal tape may be used in which, for example, copper foil or aluminum foil is disposed on the surface of the resin tape.

[0074] The winding direction of the pressure winding 21 may be the same as or different from the twisting direction of the coated electric wires 11 constituting the core 200. Note that, instead of the resin tape, a metal tape made of copper foil, aluminum foil, or the like may be used as the pressure winding 21.

[0075] When the multi-core cable 20 has the pressure winding 21 and the metal shielding layer 22 as shown in FIG. 2, the pressure winding 21 and the metal shielding layer 22 may be arranged in that order from the position closest to the core 200. [Explanation of symbols]

[0076] 10 Multi-core cable D10 Outer diameter of multi-core cable 100 cores D100 Core outer diameter 11 Covered wire 11A First coated wire 11B Second covered wire 11C Third coated wire 111 Conductor 112 Insulators 12 Outer cover T12 Jacket thickness 20 Multi-core cable 200 cores 110 Twisted pair wire 21 Retainer 22 Metal shield layer 31 Center 32 Outer periphery D111 Conductor outer diameter D11 Outside diameter of insulated wire T112 Insulation thickness

Claims

1. A core in which a plurality of coated electric wires are twisted together; and an outer jacket disposed outside the core. The thickness of the outer jacket is 0.03 mm or less, The coated electric wire has a conductor and an insulator covering the conductor, The thickness of the insulator is 5 μm or less, The insulator comprises at least one resin selected from the group consisting of polyimide and polyamideimide.

2. 2. The multi-conductor cable according to claim 1, wherein the outer diameter of the conductor is 0.032 mm or less.

3. 3. The multi-core cable according to claim 1, wherein the conductor has a core portion including iron and an outer periphery including copper disposed outside the core portion.

4. 3. The multi-core cable according to claim 1, further comprising a metal shield layer between the core and the jacket.

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