Multi-core cable

Abstract

The present disclosure provides a multi-core cable in which the outer diameter is suppressed and the deposition of a coated wire included therein is suppressed. The multi-core cable is provided with: a core formed by twisting a plurality of coated wires; the present invention relates to a coated electric wire including a core, and an outer sheath disposed outside the core, the outer sheath having a thickness of 0.03 mm or less, the coated electric wire having a conductor and an insulator covering the conductor, the insulator having a thickness of 5 [mu] m or less, the insulator containing, as a resin, one or more types selected from among polyimides and polyamideimides.

Description

Technical Field

[0001] The present disclosure relates to multi-core cables. Background Art

[0002] Patent document 1 discloses a multi-core cable comprising: a cable core formed by twisting a plurality of electric wires; a crimping tape wrapped around the cable core; a shielding member provided on the outer periphery of the crimping tape; and a sheath covering the outer side of the shielding member.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-046647

[0006] Conventionally, multi-core cables in which a plurality of electric wires and the like are integrated and assembled have been used for various purposes.

[0007] In recent years, devices and tubes equipped with multi-core cables are inserted into living bodies for the purpose of inspection, surgery, etc. Multi-core cables used in living bodies are required to have a reduced outer diameter in order to reduce the burden on the living body.

[0008] However, if the coating thickness of the covered electric wires included in the multi-core cable is reduced in order to reduce the outer diameter of the multi-core cable, the coating of the covered electric wires included in the multi-core cable may melt due to the heat when the outer sheath of the multi-core cable is formed, and the covered electric wires may be welded to each other. Summary of the invention

[0009] Therefore, an object of the present disclosure is to provide a multi-core cable having a suppressed outer diameter and suppressed welding of the included covered electric wires.

[0010] The multi-core cable disclosed herein comprises: a core formed by twisting a plurality of covered electric wires; and a sheath arranged outside the core, the thickness of the sheath being less than 0.03 mm, the covered electric wire comprising a conductor and an insulator covering the conductor, the thickness of the insulator being less than 5 μm, and the insulator comprising one or more selected from polyimide and polyamide-imide as a resin.

[0011] Effects of the Invention

[0012] According to the present disclosure, it is possible to provide a multi-core cable in which the outer diameter is suppressed and the welding of the included covered electric wires is suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a cross-sectional view of a multi-core cable according to one embodiment of the present disclosure, taken on a plane perpendicular to the longitudinal direction.

[0014] Figure 2This is a cross-sectional view of a multi-core cable according to one embodiment of the present disclosure, taken on a plane perpendicular to the longitudinal direction.

[0015] Figure 3 This is a cross-sectional view of a covered electric wire included in a multi-core cable according to one aspect of the present disclosure, taken on a plane perpendicular to the longitudinal direction.

[0016] Description of reference numerals:

[0017] 10: Multi-core cable;

[0018] D10: outer diameter of multi-core cable;

[0019] 100: core;

[0020] D100: outer diameter of the core;

[0021] 11: covered wire;

[0022] 11A: first covered electric wire;

[0023] 11B: second covered electric wire;

[0024] 11C: Third covered electric wire;

[0025] 111: Conductor;

[0026] 112: Insulator;

[0027] 12: skin;

[0028] T12: thickness of the outer skin;

[0029] 20: Multi-core cable;

[0030] 200: core;

[0031] 110: twisted pair wire;

[0032] 21: Pressing;

[0033] 22: Metal shielding layer;

[0034] 31: center;

[0035] 32: Peripheral part;

[0036] D111: outer diameter of the conductor;

[0037] D11: outer diameter of the coated wire;

[0038] T112: Thickness of the insulation. DETAILED DESCRIPTION

[0039] Hereinafter, specific implementation methods will be described.

[0040] [Description of Embodiments of the Present Disclosure]

[0041] First, the embodiments of the present disclosure are described by way of example. 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.

[0042] (1) A multi-core cable according to one embodiment of the present invention comprises: a core formed by twisting a plurality of covered electric wires; and a sheath arranged outside the core, the thickness of the sheath being 0.03 mm or less, the covered electric wire comprising a conductor and an insulator covering the conductor, the thickness of the insulator being 5 μm or less, and the insulator comprising one or more selected from polyimide and polyamide-imide as a resin.

[0043] By setting the thickness of the outer sheath to 0.03 mm or less, the outer diameter of the multi-core cable can also be suppressed.

[0044] The insulator contains one or more selected from polyimide and polyamide-imide as resin, thereby increasing the melting point of the insulator and preventing the insulator from melting due to the heat of molding the outer sheath. Therefore, the coated wires of the multi-core cable of one embodiment of the present disclosure can be prevented from being welded to each other.

[0045] By setting the thickness of the insulator to 5 μm or less, the outer diameter of the covered electric wire can be suppressed, and the outer diameter of the multi-core cable including the covered electric wire can also be suppressed.

[0046] (2) In (1), the outer diameter of the conductor may be 0.032 mm or less.

[0047] 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 suppressed.

[0048] (3) In (1) or (2), the conductor may include a central portion made of iron and a peripheral portion arranged outside the central portion and made of copper.

[0049] The conductor has a central portion containing iron, thereby increasing the strength of the conductor and reducing the outer diameter of the conductor, thereby preventing the covered electric wire from being broken even when the multi-core cable is repeatedly bent.

[0050] Furthermore, the conductor has an outer peripheral portion containing copper, whereby the electrical characteristics of the conductor can be improved.

[0051] (4) In any one of (1) to (3), a metal shield layer may be provided between the core and the sheath.

[0052] The metal shield layer can suppress the superposition of noise on the signal transmitted by the coated wire. In addition, the metal shield layer can suppress the influence of noise on external devices.

[0053] [Details of the embodiments of the present disclosure]

[0054] Hereinafter, a specific example of a multi-core cable of an embodiment of the present disclosure (hereinafter referred to as "this embodiment") is described with reference to the accompanying drawings. It should be noted that the present invention is not limited to these examples, but is shown by the claims, and is intended to include all changes within the meaning and scope equivalent to the claims.

[0055] In this specification, the names of components may be described by adding first, second, third, etc., such as first covered electric wire, second covered electric wire, and third covered electric wire. First, second, third, etc. are only recorded to distinguish each component and prevent confusion during description, and do not indicate arrangement, priority, etc. Therefore, when there is no particular concern about confusion or when a summary description is required, it can be simply described as a covered electric wire.

[0056] [Multi-core cable]

[0057] exist Figure 1 , a configuration example of a cross section perpendicular to the longitudinal direction of the multi-core cable 10 of the present embodiment is shown. Figure 2 2 shows another example of the cross section perpendicular to the longitudinal direction of the multi-core cable 20 of the present embodiment. Figure 3 2 shows a configuration example of a cross section of the covered electric wire 11 perpendicular to the longitudinal direction.

[0058] Figure 2 This is a modified example of the multi-core cable of the present embodiment, and therefore, the main Figure 1 , Figure 3 To illustrate, use as needed Figure 2 to explain.

[0059] like Figure 1 As shown, the multi-core cable 10 of the present embodiment includes a core 100 formed by twisting a plurality of coated electric wires 11 , and a sheath 12 disposed outside the core 100 .

[0060] Each member included in the multi-core cable of this embodiment will be described.

[0061] (1) core

[0062] (1-1) Regarding the structure of the coated electric wire having the core

[0063] The structure of the covered electric wire 11 included in the core 100 is not particularly limited.

[0064] For example, Figure 1 As shown, the core 100 may have a structure in which a plurality of first covered electric wires 11A having the same outer diameter and material are twisted together.

[0065] In addition, if Figure 2 As in the multi-core cable 20 shown in FIG. 1 , the core 200 may have a structure in which a plurality of covered electric wires having different outer diameters and the like are twisted together, such as the first covered electric wire 11A, the second covered electric wire 11B, and the third covered electric wire 11C. Figure 2 Like the third covered electric wire 11C in the core 200 shown in the figure, two covered electric wires are twisted together to form a twisted pair electric wire 110 , and then the twisted pair electric wire 110 is twisted together with other covered electric wires 11 to form the core 200 .

[0066] The structure of the core and the covered electric wire of the multi-core cable of this embodiment is not limited to Figure 1 , Figure 2 The core of the multi-core cable of the present embodiment may be a structure in which an arbitrary number of covered electric wires selected in accordance with the application are combined and twisted.

[0067] The core 100 may be configured such that the covered electric wires 11 are twisted together. That is, the core 100 may be configured such that the covered electric wires 11 are arranged in multiple layers from the center of the core 100, and the covered electric wires 11 are twisted together at the same twisting pitch, rather than twisting the covered electric wires 11 in each layer. By twisting the covered electric wires 11 together, the covered electric wires 11 included in the multi-core cable 10 are less likely to break even when the multi-core cable 10 is repeatedly bent.

[0068] (1-2) Regarding covered electric wires

[0069] like Figure 1 , Figure 3 As shown, the covered electric wire 11 has a conductor 111 and an insulator 112 covering the conductor 111 .

[0070] (conductor)

[0071] The outer diameter D111 of the conductor 111 (see Figure 3 ) can be selected according to the application and is not particularly limited. However, from the viewpoint of suppressing the outer diameter D10 of the multi-core cable 10, the outer diameter D111 of the conductor 111 may also be suppressed.

[0072] 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 suppressed.

[0073] The outer diameter D111 of the conductor 111 may be set to 0.032 mm or less. By setting the outer diameter D111 of the conductor 111 to 0.032 mm or less, the outer diameter D10 of the multi-core cable 10 can be particularly suppressed.

[0074] 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.

[0075] The outer diameter D111 of the conductor 111 can be obtained by measuring two orthogonal diameters on a cross section perpendicular to the longitudinal direction of the covered electric wire 11 and setting the average value thereof. 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 be measured and calculated in the same manner except that the evaluation objects are changed to the covered electric wire 11, the multi-core cable 10, and the core 100.

[0076] like Figure 2 In the case of a covered electric wire 11 including conductors 111 of different sizes, as in the multi-core cable 20 shown in the figure, for example, the outer diameter D111 of the conductor 111 of at least a part of the covered electric wire 11 may be arranged to satisfy the above range. Alternatively, the outer diameter D111 of the conductor 111 of all the covered electric wires 11 may satisfy the above range.

[0077] The conductor 111 may include a single conductor wire or a plurality of conductor wires. When the conductor includes a plurality of conductor wires, the plurality of conductor wires may be twisted in advance. That is, when the conductor includes a plurality of conductor wires, the conductor may also be a twisted wire of the plurality of conductor wires.

[0078] The material of the conductor 111 is not particularly limited, but for example, a copper alloy or copper can be used. As copper, for example, soft copper can be used. Tin or silver plating can also be performed. In view of electrical conductivity and tensile strength, a silver-copper alloy can also be used.

[0079] The covered electric wire 11 included in the multicore cable 10 of this embodiment may have a smaller outer diameter D111 of the conductor 111. However, if the outer diameter D111 of the conductor 111 is reduced, the covered electric wire 11 is easily broken when the multicore cable 10 is repeatedly bent.

[0080] Therefore, if Figure 3 As shown, when strength exceeding that of a copper alloy wire is required, the conductor 111 of the covered electric wire 11 may include a central portion 31 made of iron and a peripheral portion 32 disposed outside the central portion 31 and made of copper.

[0081] The conductor 111 has the central portion 31 made of iron, thereby increasing the strength of the conductor 111 and reducing the outer diameter D111 of the conductor 111 , thereby preventing the covered electric wire 11 from breaking even when the multi-core cable 10 is repeatedly bent.

[0082] Furthermore, since the conductor 111 has the outer peripheral portion 32 made of copper, the electrical characteristics of the conductor 111 can be maintained well.

[0083] As a material containing iron used for the center portion 31, stainless steel such as SUS316L is mentioned, for example.

[0084] Examples of the material containing copper used for the outer peripheral portion 32 include soft copper and copper alloys.

[0085] The conductor 111 having the central portion 31 and the outer peripheral portion 32 can be manufactured by, for example, drawing a base material obtained by copper plating on the surface of stainless steel. Figure 3 Schematically shown in FIG. 1 , an example is shown in which the center portion 31 and the outer peripheral portion 32 are arranged in concentric circles, but the present invention is not limited to this form.

[0086] (Insulator)

[0087] The insulator 112 may include one or more selected from polyimide and polyamide-imide as resin.

[0088] The insulator 112 contains one or more selected from polyimide and polyamide-imide as resin, thereby increasing the melting point of the insulator 112 and preventing the insulator 112 from melting due to the heat when the outer sheath 12 is molded. Therefore, the covered electric wires 11 of the multi-core cable 10 of this embodiment can be prevented from being welded to each other.

[0089] The insulator 112 can be manufactured, for example, by baking and curing the above-mentioned resin on the surface of the conductor 111. Therefore, the insulator 112 may be composed only of the above-mentioned resin.

[0090] The thickness T112 of the insulator 112 is not particularly limited, but can be set to 5 μm or less, for example. By setting the thickness T112 of the insulator 112 to 5 μm or less, the outer diameter D11 of the covered wire 11 can be suppressed, and the outer diameter D10 of the multi-core cable 10 including the covered wire 11 can also be suppressed.

[0091] 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.

[0092] The thickness T112 of the insulator 112 can be set to a value obtained by subtracting the outer diameter D111 of the conductor 111 from the outer diameter D11 of the covered electric wire 11 and dividing the value by 2.

[0093] (2) Skin

[0094] The sheath 12 may be disposed outside the core 100 .

[0095] Since the multi-core cable 10 has the outer sheath 12 , the covered electric wires 11 and the like arranged inside can be protected.

[0096] The outer skin 12 may contain fluororesin as a resin material.

[0097] Since the outer skin 12 includes fluororesin as the resin material, sufficient strength can be ensured even when the thickness T12 of the outer skin 12 is suppressed.

[0098] As the fluororesin, for example, one or more selected from polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer (ETFE), etc. can be used.

[0099] The resin material contained in the outer skin 12 may or may not be cross-linked.

[0100] The outer skin 12 may also be composed only of the above-mentioned resin material, but in addition to the resin material, the outer skin 12 may also contain one or more additives selected from flame retardants, flame retardant aids, antioxidants, lubricants, colorants, reflectivity imparting agents, masking agents, processing stabilizers, plasticizers, etc.

[0101] 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 suppressed.

[0102] The lower limit of the thickness T12 of the outer skin 12 is not particularly limited, but may be, for example, 0.01 mm or more. That is, the thickness T12 of the outer skin 12 may be, for example, 0.01 mm or more and 0.03 mm or less.

[0103] The thickness T12 of the outer sheath 12 can be set to a value obtained 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 2.

[0104] (3) About other components

[0105] The multi-core cable of the present embodiment may have any other members in addition to the core 100 and the sheath 12 .

[0106] For example, Figure 2 As shown, the multi-core cable 20 may also have a metallic shield 22 between the core 200 and the outer sheath 12 .

[0107] (3-1) Metal shielding layer

[0108] The metal shield layer 22 can suppress the superposition of noise on the signal transmitted by the covered electric wire 11. In addition, the metal shield layer 22 can suppress the influence of noise on external equipment.

[0109] The metal shielding layer 22 may include a conductive material.

[0110] For example, the metal shielding layer 22 may be formed by winding a conductive tape including a conductive layer into a spiral shape along the length direction of the core 200 .

[0111] In this case, the conductive tape may be composed of only a conductive layer, or may be configured such that the conductive layer is disposed on one or more surfaces selected from the upper surface and the lower surface of the base member.

[0112] The material of the conductive layer is not particularly limited, and may include metal, such as metal foil. When the conductive layer includes metal, the material of the metal is not particularly limited, and may include copper, copper alloy, aluminum, aluminum alloy, etc.

[0113] The material of the base member is not particularly limited, and may be composed of insulating materials such as organic polymer materials and nonwoven fabrics. Examples of organic polymer materials include polyester resins such as polyethylene terephthalate (PET), polyolefin resins such as polypropylene, and vinyl resins such as polyvinyl chloride. The base member may be a base member including an insulating material or a base member formed only of an insulating material.

[0114] When the metal shielding layer 22 is formed by winding a conductive tape, the winding direction of the conductive tape may be arbitrarily selected, for example, it may be the same direction as the twisting direction of the core 200 or a direction different from the twisting direction of the core 200 .

[0115] The metal shield layer 22 may be formed of metal wires. In this case, the metal shield layer 22 may be formed by arranging the metal wires in any one structure selected from a braided structure and a transversely wound structure.

[0116] Copper, aluminum, copper alloy, etc. can be used as the material of the metal wire. As for the metal wire, silver or tin plating treatment can also be implemented on the surface. Therefore, for example, silver-plated copper alloy, tin-plated copper alloy, etc. can also be used as the metal wire.

[0117] (3-2) Rolling

[0118] like Figure 2 As shown, the multi-core cable 20 may also have a crimp 21 covering the outer surface of the core 200 .

[0119] The crimp 21 can stabilize the arrangement of the coated electric wires 11 included in the multi-core cable 20 and can bundle them.

[0120] As the press roll 21 , for example, a resin tape may be used.

[0121] Examples of the resin used for the resin belt include one or more selected from fluororesins such as polytetrafluoroethylene (PTFE) resin, polyester resins such as polyethylene terephthalate (PET) resin, and polyethylene (PE) that are excellent in heat resistance and abrasion resistance.

[0122] The resin tape used as the roll 21 may contain a conductive material such as carbon for conductivity. Alternatively, the conductive material may be added in a dispersed manner in the resin constituting the resin tape. In addition, for example, a metal tape obtained by placing copper foil or aluminum foil on the surface of the resin tape may also be used.

[0123] The winding direction of the roll 21 may be the same as or different from the twisting direction of the covered electric wires 11 constituting the core 200. It should be noted that as the roll 21, a metal tape formed of copper foil, aluminum foil, etc. may be used instead of the resin tape.

[0124] like Figure 2 When the multi-core cable 20 shown in the figure has the crimp 21 and the metal shield 22 , the crimp 21 and the metal shield 22 may be arranged in this order from the position close to the core 200 .

Claims

1. A multi-core cable having: A core formed by twisting a plurality of coated wires; and a skin, arranged outside the core, The thickness of the outer skin is less than 0.03 mm, The covered electric wire has a conductor and an insulator covering the conductor. The thickness of the insulator is less than 5 μm, The insulator includes one or more selected from polyimide and polyamideimide as a resin.

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

3. The multi-core cable according to claim 1 or 2, wherein: The conductor includes a central portion including iron and a peripheral portion disposed outside the central portion including copper.

4. The multi-core cable according to claim 1 or 2, wherein: There is a metal shielding layer between the core and the sheath.

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