Method for manufacturing a cable

Abstract

To provide a cable manufacturing method enabling detection of a pinhole of an outer coating in a manufacturing process of the cable.SOLUTION: A cable manufacturing method includes: an outer coating forming step of forming an outer coating on the outer periphery of a temporary line having a dummy line and a shield layer coating the outer surface of the dummy line, thereby obtaining a temporary line with an outer coating; an evaluation step of installing an electrode on the outer surface of the outer coating, measuring current between the electrode and the shield layer while applying voltage to between the electrode and the shield layer, and evaluating withstand voltage characteristics of the outer coating; and a removal step of removing the temporary line.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a cable.

Background Art

[0002] Patent Document 1 discloses a multi-core cable characterized in that a plurality of coaxial cables are arranged within a shield layer, and a sheath is provided on the outer periphery of the shield layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to protect covered electric wires and the like disposed inside, a cable usually has an outer sheath on its outer surface. Since the outer sheath contains a resin component that is an insulator, it also functions to enhance the withstand voltage characteristics of the cable.

[0005] However, if the outer sheath contains holes such as pinholes that penetrate between the inner surface and the outer surface of the outer sheath, there is a risk that the withstand voltage characteristics of the cable cannot be sufficiently enhanced.

[0006] Therefore, an object of the present disclosure is to provide a method for manufacturing a cable capable of detecting pinholes in the outer sheath during the manufacturing process.

Means for Solving the Problems

[0007] The method for manufacturing a cable according to the present disclosure includes an outer sheath forming step of forming an outer sheath on the outer periphery of a dummy wire having a dummy wire and a shield layer covering the outer surface of the dummy wire to obtain a dummy wire with an outer sheath, An evaluation step of installing an electrode on the outer surface of the outer sheath, measuring the current between the electrode and the shield layer while applying a voltage between the electrode and the shield layer, and evaluating the withstand voltage characteristics of the outer sheath; And a removing step of removing the temporary wire.

Advantages of the Invention

[0008] According to the present disclosure, a method for manufacturing a cable capable of detecting pinholes in an outer sheath during the manufacturing process can be provided.

Brief Description of the Drawings

[0009]

Figure 1A

Figure 1B

Figure 2A

Figure 2B

Figure 2C

Figure 2D

Figure 2E

Figure 3A

Figure 3B

Figure 4

Embodiments for Carrying Out the Invention

[0010] Embodiments for carrying out the invention will be described below.

[0011] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described. In the following description, the same or corresponding elements are denoted by the same reference numerals, and the same description thereof will not be repeated.

[0012] (1) A method for manufacturing a cable according to an aspect of the present disclosure includes a step of forming an outer sheath on the outer periphery of a dummy wire having a dummy wire and a shield layer covering the outer surface of the dummy wire to obtain a dummy wire with an outer sheath, a step of installing an electrode on the outer surface of the outer sheath, measuring the current between the electrode and the shield layer while applying a voltage between the electrode and the shield layer, and evaluating the withstand voltage characteristics of the outer sheath, and a step of removing the dummy wire.

[0013] In the method for manufacturing a cable according to an aspect of the present disclosure, since the dummy wire includes a shield layer, a pinhole in the outer sheath can be easily detected by applying a voltage with an electrode installed on the surface of the outer sheath and detecting the current value between the electrode and the shield layer. Therefore, pinholes in the outer sheath can be detected during the manufacturing process.

[0014] (2) The shield layer may have a braided structure.

[0015] When the shield layer has a braided structure, it is difficult for wrinkles or the like to enter the shield layer when removing the dummy wire in the removing step. Therefore, the force required for removing the dummy wire can be suppressed, and workability can be improved. Further, when removing the dummy wire, it is difficult for wrinkles or the like to enter the shield layer, and the shape of the shield layer can be maintained. Therefore, the dummy wire can be repeatedly used, and the manufacturing cost of the cable can be suppressed.

[0016] (3) During the evaluation step, the position where the electrode contacts the outer surface of the outer sheath may be changed along the longitudinal direction of the dummy wire with the outer sheath.

[0017] By changing (displacing) the position where the electrode contacts on the outer surface of the jacket along the longitudinal direction of the temporary wire with the jacket, the overall withstand voltage characteristics along the longitudinal direction of the jacket can be evaluated. That is, the presence or absence of pinholes can be evaluated for the entire jacket.

[0018] (4) After the removal step, an insertion step of inserting an internal wire into the space inside the jacket formed by removing the temporary wire may be included.

[0019] By performing the insertion step, an internal wire for transmitting signals or the like can be arranged inside the jacket, and a cable with excellent withstand voltage characteristics can be obtained.

[0020] (5) There may be a gap between the internal wire and the inner surface of the jacket.

[0021] By providing a gap between the internal wire and the inner surface of the jacket, in the insertion step, the internal wire can be easily inserted into the space inside the jacket, and the workability can be improved. Also, by providing a gap between the internal wire and the inner surface of the jacket, when the cable is bent, the internal wire can move along the longitudinal direction, and the flexibility of the cable can be improved.

[0022] (6) The internal wire may have a plurality of coated wires.

[0023] By including a plurality of coated wires in the internal wire, the types of corresponding devices can be increased.

[0024] (7) The coated wire may include a coaxial cable.

[0025] By including a coaxial cable in the coated wire, signal leakage to the outside and radio wave intrusion from the outside can be suppressed.

[0026] (8) The internal wire may have an overall shield layer covering the outer surface.

[0027] By having an internal wire with a comprehensive shielding layer, signal leakage to the outside and radio wave intrusion from the outside can be suppressed.

[0028] [Details of Embodiments of the Present Disclosure] A specific example of a method for manufacturing a cable according to an embodiment of the present disclosure (hereinafter referred to as "this embodiment") will be described below with reference to the drawings. It should be noted 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. (Method for Manufacturing Cable) FIG. 1A shows a flowchart 10 of the method for manufacturing the cable of this embodiment.

[0029] As shown in FIG. 1A, the method for manufacturing the cable of this embodiment includes an outer sheath forming step S1, an evaluation step S2, and a removal step S3. Each step will be described below. (1) Outer Sheath Forming Step (S1) In the outer sheath forming step, an outer sheath can be formed on the outer periphery of a dummy wire having a dummy wire and a shielding layer covering the outer surface of the dummy wire to obtain a dummy wire with an outer sheath.

[0030] FIG. 2A shows a cross-sectional view in a plane perpendicular to the longitudinal direction of the dummy wire. FIG. 2B shows an explanatory diagram of the braided structure. Further, FIG. 2C shows a cross-sectional view in a plane perpendicular to the longitudinal direction of the dummy wire with an outer sheath obtained after the outer sheath forming step. In FIG. 2A, FIG. 2C, and FIGS. 2D and 2E described later, the direction perpendicular to the paper surface is the longitudinal direction of the cable, outer sheath, dummy wire, etc. (1-1) Dummy Wire As shown in FIG. 2A, the dummy wire 20 can have a dummy wire 21 and a shielding layer 22 covering the outer surface of the dummy wire 21. The dummy wire 20 is a member for supporting the outer sheath formed in the outer sheath forming step and forming a space into which an internal wire or the like can be inserted after removing the dummy wire in the removal step S3 described later. (Dummy Wire) The material of the dummy wire 21 is not particularly limited, but it is preferably made of resin, and more preferably a resin that does not deform when forming the outer covering. As the material of the dummy wire 21, one or more selected from polypropylene (PP), polyvinyl chloride (PVC), etc. can be preferably used.

[0031] The dummy wire 21 can have a shape corresponding to the inner wire to be covered with the outer covering. For example, as shown in FIG. 2A, the shape in a plane perpendicular to the longitudinal direction can be circular. Note that the above-mentioned circular shape includes various circular shapes such as a perfect circle and an ellipse. (Shield layer) The shield layer 22 can be arranged to cover the outer surface of the dummy wire 21, specifically, the outer surface along the longitudinal direction of the dummy wire 21.

[0032] When performing the evaluation process described later, by applying a voltage between the electrode installed on the outer surface of the outer covering and the shield layer 22 and measuring the current value flowing between the two members, it is possible to evaluate whether the outer covering has pinholes.

[0033] The configuration of the shield layer 22 is not particularly limited, and for example, it can have a metal foil or a metal wire. Note that the shield layer 22 preferably has a metal foil or a metal wire on the outer surface side, that is, the side in contact with the outer covering.

[0034] When the shield layer 22 has a metal foil, the shield layer 22 can have a configuration including a metal tape having a metal foil wound spirally along the longitudinal direction of the dummy wire 21 on the outer surface of the dummy wire 21, for example. In the above case, the shield layer 22 can also be composed of the above metal tape.

[0035] As described above, when the shield layer 22 contains a metal tape, the configuration of the metal tape is not particularly limited, but the metal tape preferably has a metal foil on at least one surface of the base material. Also, an adhesive may be arranged on the surface of the base material opposite to the surface on which the metal foil is formed so as to fix the shield layer 22 to the outer surface of the dummy wire 21.

[0036] The material of the metal foil included in the shield layer 22 is not particularly limited as long as it is a conductive material from the viewpoint of evaluating the withstand voltage characteristics in the evaluation process described later. For example, it is preferable that the metal foil is copper or aluminum. By using copper or aluminum as the metal foil included in the shield layer 22, a metal foil having uniform and sufficient conductivity can be obtained.

[0037] In addition, the shield layer 22 can also have a metal wire as described above. In this case, the shield layer 22 can have, for example, a structure in which a metal wire is wound around the outer periphery of the dummy wire 21 or arranged in a braided structure. An example of the braided structure 22A is shown in FIG. 2B. As shown in FIG. 2B, the braided structure 22A has a structure in which metal wires 221 are combined and braided. As shown in FIG. 2B, the braided structure 22A can have a structure in which the metal wires 221 are braided so as to cross each other and have knots 222 at the intersections.

[0038] As the material of the metal wire included in the shield layer 22, copper, aluminum, a copper alloy, or the like can be used. The metal wire of the shield layer 22 may be subjected to a silver or tin plating treatment on the surface. Therefore, as the metal wire of the shield layer 22, for example, a silver-plated copper alloy, a tin-plated copper alloy, or the like can also be used.

[0039] Here, the case where the shield layer 22 has the above metal foil is taken as the first configuration example. The case where the shield layer 22 has a metal wire arranged in a wound structure is taken as the second configuration example. The case where the shield layer has a metal wire arranged in a braided structure is taken as the third configuration example.

[0040] According to the study of the inventors of the present invention, in any of the above first configuration example, second configuration example, and third configuration example, the withstand voltage characteristics of the outer sheath can be evaluated in the evaluation process described later. Therefore, as described above, the structure of the outer sheath may be any of the first configuration example to the third configuration example.

[0041] In the removal process described later, the dummy wire 20 will be pulled out from the outer sheath. According to the study by the inventor of the present invention, when the removal process is carried out, except for the case where the shield layer has a braided structure of metal wires in the above-described third configuration example, the shield layer 22 is deformed and wrinkles or the like are inserted. For this reason, when removing the dummy wire in the removal process, a large force is required, workability is deteriorated, and it may be difficult to repeatedly use the dummy wire portion.

[0042] On the other hand, when the shield layer 22 has a braided structure as described above, when removing the dummy wire 20 in the removal process (S3) described later, it is difficult for wrinkles or the like to enter the shield layer 22. Therefore, the force required for removing the dummy wire 20 can be suppressed, and workability can be improved. Further, when removing the dummy wire 20, it is difficult for wrinkles or the like to enter the shield layer 22, and the shape of the shield layer 22 can be maintained. Therefore, the dummy wire 20 can be repeatedly used, and the manufacturing cost of the cable can be suppressed. Therefore, it is preferable that the shield layer has a braided structure, that is, includes a metal wire having a braided structure. (1-2) Outer sheath As shown in FIG. 2C, an outer sheath 23 can be formed on the outer periphery 20A which is the outer surface of the dummy wire 20. By forming the outer sheath 23 on the outer periphery of the dummy wire 20, a dummy wire 200 with an outer sheath is obtained as shown in FIG. 2C.

[0043] The method for forming the outer sheath 23 is not particularly limited. For example, it can be formed by solid extrusion molding or draw-down extrusion molding.

[0044] The material of the outer sheath 23 can be selected according to the characteristics required for the cable to be manufactured. The outer sheath 23 can contain one or more selected from, for example, vinyl chloride and polyurethane as resin components.

[0045] The resin component of the outer sheath 23 may or may not be crosslinked.

[0046] The outer sheath 23 can also contain additives such as a flame retardant, a flame retardant aid, an antioxidant, a lubricant, a coloring agent, a reflection imparting agent, a concealing agent, a processing stabilizer, and a plasticizer in addition to the above resin component. (2) Evaluation Process (S2) In the evaluation process, an electrode is installed on the outer surface of the jacket, and while applying a voltage between the electrode and the shield layer, the current between the electrode and the shield layer is measured, and the withstand voltage characteristics of the jacket can be evaluated.

[0047] FIG. 3A and FIG. 3B show explanatory diagrams of the evaluation method in the evaluation process.

[0048] FIG. 3A is a diagram schematically showing a state in which the withstand voltage characteristics of the jacket 23 are being evaluated for the dummy wire 200 with a jacket. FIG. 3B is an enlarged cross-sectional view taken along line B-B' of FIG. 3A and is schematically shown.

[0049] As shown in FIG. 3A, an electrode 31 can be installed on the outer surface of the jacket 23 so as to be in contact with the jacket 23 of the dummy wire 200 with a jacket. Although the form of the electrode 31 is not limited, as shown in FIG. 3B, it is preferable that the electrode 31 follows the shape of the outer surface of the dummy wire 200 with a jacket and is configured to be able to contact the outer surface. For this reason, the electrode 31 preferably has, for example, a bead-like form in which spherical conductors are connected.

[0050] Then, by applying a voltage between the electrode 31 and the shield layer 22 of the dummy wire 200 with a jacket by an inspection device 32, while applying a voltage to the outer surface of the jacket 23 of the dummy wire 200 with a jacket, the current between the jacket 23 and the shield layer 22 can be measured and the withstand voltage characteristics can be evaluated.

[0051] For example, as shown in FIG. 3B, when the jacket 23 has a pinhole 33, a current flows between the electrode 31 and the shield layer 22, and the measured current value increases. Therefore, it can be detected that the jacket 23 has a pinhole. Also, when the jacket 23 does not have a pinhole 33, no current flows or is suppressed between the electrode 31 and the shield layer 22, so it can be detected that the jacket 23 does not have a pinhole.

[0052] When it is detected that the jacket 23 has a pinhole, the jacket 23 can be excluded from the production line so as not to be used as the material for the cable to be manufactured. At this time, only the portion of the jacket 23 including the pinhole may be cut and excluded, or the entire jacket 23 may be excluded. The exclusion of the jacket including the pinhole may be performed within the evaluation process, or separately, an exclusion process for excluding the jacket including the pinhole from the production line may be provided.

[0053] In the evaluation process, the magnitude of the voltage applied between the electrode 31 and the shield layer 22 and the criteria for determining that the jacket 23 has a pinhole can be set according to the cable to be manufactured because they depend on the material, thickness of the jacket 23, the size of the pinhole to be detected, etc.

[0054] During the evaluation process, the position on the outer surface of the jacket 23 where the electrode 31 contacts can also be changed along the longitudinal direction of the temporary wire 200 with the jacket. Specifically, for example, as shown in FIG. 3A, the temporary wire 200 with the jacket including the jacket 23 for evaluating the withstand voltage characteristics can be conveyed along the arrow A along its longitudinal direction.

[0055] In this way, by changing (displacing) the position on the outer surface of the jacket 23 where the electrode 31 contacts along the longitudinal direction of the temporary wire 200 with the jacket, the overall withstand voltage characteristics along the longitudinal direction of the jacket 23 can be evaluated. That is, the presence or absence of pinholes in the entire jacket 23 can be evaluated.

[0056] Although the electrode 31 side can also be moved, usually, since the temporary wire 200 with the jacket is long, it is preferable to convey the temporary wire 200 with the jacket.

[0057] In the method for manufacturing a cable according to the present embodiment, since the temporary wire 20 includes the shield layer 22, a voltage is applied by the electrode 31 in contact with the surface of the outer sheath 23, and the current value between the electrode 31 and the shield layer 22 is detected, so that the pinholes in the outer sheath 23 can be easily detected. Therefore, according to the method for manufacturing a cable of the present embodiment, the pinholes in the outer sheath 23 can be detected during the manufacturing process. Further, according to the method for manufacturing a cable of the present embodiment, the outer sheath 23 including pinholes can be removed, and a cable excellent in withstand voltage characteristics can be manufactured. (3) Removal step (S3) In the removal step, the temporary wire 20 can be removed from the temporary wire 200 with the outer sheath.

[0058] FIG. 2D shows a cross-sectional view of the outer sheath obtained after the removal step in a plane perpendicular to the longitudinal direction of the outer sheath. By removing the temporary wire 20 from the temporary wire 200 with the outer sheath, as shown in FIG. 2D, only the outer sheath 23 can be obtained. By removing the temporary wire 20, the outer sheath 23 will have a space 24 inside.

[0059] For example, while gripping the outer sheath 23 with a first gripper, gripping the end of the temporary wire 20 with a second gripper such as pliers, and pulling it along the longitudinal direction, the temporary wire 20 can be pulled out from the temporary wire 200 with the outer sheath. The pulled-out temporary wire 20 can also be reused in the outer sheath forming step (S1).

[0060] By performing the above-described outer sheath forming step (S1), evaluation step (S2), and removal step (S3), the presence or absence of pinholes in the outer sheath can be evaluated. Therefore, pinholes in the outer sheath 23 can be detected during the manufacturing process, and an outer sheath with suppressed pinholes or a cable including the outer sheath can be manufactured. (4) Insertion step (S4) As shown in the flowchart 11 shown in FIG. 1B, the method for manufacturing a cable according to the present embodiment can also include an insertion step (S4) in addition to the above-described outer sheath forming step (S1), evaluation step (S2), and removal step (S3).

[0061] In the insertion step (S4), after the removal step (S3), the internal wire 25 (see FIG. 2E) can be inserted into the space 24 within the jacket 23 formed by removing the phantom line 20.

[0062] By performing the insertion step (S4), an internal wire for transmitting signals or the like can be disposed within the jacket 23, thereby obtaining a cable having excellent withstand voltage characteristics.

[0063] FIG. 2E shows a cross-sectional view taken in a plane perpendicular to the longitudinal direction of the cable obtained after the insertion step. As shown in FIG. 2E, in the insertion step (S4), the internal wire 25 can be inserted into the space within the jacket 23 to form the cable 210.

[0064] The configuration of the internal wire 25 can be selected according to the performance requirements of the cable to be manufactured.

[0065] For example, the internal wire 25 can also have a plurality of coated wires. By including a plurality of coated wires in the internal wire 25, the types of corresponding devices can be increased.

[0066] When the internal wire 25 has a plurality of coated wires, the plurality of coated wires can be twisted together. Without being limited to the above form, the internal wire 25 can also have only one coated wire.

[0067] The type of coated wire included in the internal wire 25 is not particularly limited. For example, the coated wire can also include a coaxial cable. By including a coaxial cable in the coated wire, signal leakage to the outside and radio wave intrusion from the outside can be suppressed.

[0068] Also, the internal wire 25 can have an overall shield layer covering the outer surface of the coated wire. By having an overall shield layer in the internal wire 25, signal leakage to the outside and radio wave intrusion from the outside can be suppressed. When the internal wire 25 has a plurality of coated wires, the overall shield layer can be arranged to cover the plurality of coated wires together. The overall shield layer can have, for example, a metal foil or a metal wire.

[0069] When the comprehensive shielding layer has a metal foil, the comprehensive shielding layer can be configured to include, for example, a metal tape having a metal foil wound along the longitudinal direction of the inner wire around the outer circumference of the inner wire. In the above case, the comprehensive shielding layer can also be composed of the above metal tape.

[0070] As described above, when the comprehensive shielding layer contains a metal tape, the configuration of the metal tape is not particularly limited, but the metal tape preferably has a metal foil on at least one surface of the base material. Also, an adhesive may be disposed on the surface of the base material opposite to the surface on which the metal foil is formed, and the comprehensive shielding layer may be configured to be fixed to the outer surface of the inner wire.

[0071] The material of the metal foil included in the comprehensive shielding layer is preferably, for example, that the metal foil is copper or aluminum. By using copper or aluminum as the metal foil included in the comprehensive shielding layer, a metal foil having uniform and sufficient conductivity can be obtained.

[0072] Also, the comprehensive shielding layer can also have a metal wire as described above. In this case, the comprehensive shielding layer can have a structure in which, for example, the metal wire is wound horizontally or arranged in a braided structure around the outer circumference of the inner wire. As the material of the metal wire included in the comprehensive shielding layer, copper, aluminum, copper alloy, etc. can be used. The metal wire of the comprehensive shielding layer may be subjected to a silver or tin plating treatment on the surface. Therefore, as the metal wire of the comprehensive shielding layer, for example, a silver-plated copper alloy, a tin-plated copper alloy, etc. can also be used.

[0073] A gap 26 can also be provided between the inner wire 25 and the inner surface 23A of the outer sheath 23. That is, the outer diameter D25 of the inner wire 25 can be made smaller than the inner diameter D23 of the outer sheath 23.

[0074] By providing a gap between the internal wire 25 and the inner surface 23A of the outer sheath 23, in the insertion step S4, the internal wire 25 can be easily inserted into the space 24 within the outer sheath 23, enhancing workability. Also, by providing a gap between the internal wire 25 and the inner surface 23A of the outer sheath 23, when the cable 210 is bent, the internal wire 25 can move along the longitudinal direction, enhancing the flexibility of the cable 210. (Configuration example of cable) FIG. 4 shows an explanatory diagram of a configuration example of a cable obtained by the manufacturing method of the cable of the present embodiment. Also in FIG. 4, the direction perpendicular to the plane of the paper is the longitudinal direction of the cable.

[0075] As shown in FIG. 4, the cable 40 can have a configuration in which the internal wire 25 is disposed in the space within the outer sheath 23. At this time, as described above, it is preferable to have a gap 26 between the internal wire 25 and the inner surface 23A of the outer sheath 23. (Covered wire) In the cable 40 shown in FIG. 4, the internal wire 25 shows an example of having a coaxial cable 41 as a covered wire.

[0076] The coaxial cable 41 has, in a cross-section perpendicular to the longitudinal direction, an internal conductor 411, an insulator 412, a shield conductor 413, and an outer peripheral covering 414 in order from the center side.

[0077] Examples of the material of the internal conductor 411 include copper, aluminum, copper alloys, etc. The internal conductor may be subjected to a plating treatment of silver or tin on the surface. For this reason, as the internal conductor 411, for example, a silver-plated copper alloy or a tin-plated copper alloy can also be used. The internal conductor 411 may be a single wire (element wire) or a stranded wire formed by twisting a plurality of element wires.

[0078] The material constituting the insulator 412 is not particularly limited, and resins such as fluororesins like polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer (ETFE), and polyester resins such as polyethylene terephthalate (PET) can be used as the resin component.

[0079] The shield conductor 413 can have a structure in which a metal wire is wound horizontally or arranged in a braided structure around the outer periphery of the insulator 412. As the material of the metal wire of the shield conductor 413, copper, aluminum, copper alloy, etc. can be used. The metal wire of the shield conductor may be subjected to a silver or tin plating treatment on the surface. Therefore, as the metal wire of the shield conductor, for example, silver-plated copper alloy, tin-plated copper alloy, etc. can also be used.

[0080] The material constituting the outer coating 414 is not particularly limited, and as the resin component, the fluororesins and polyester resins, etc. of the insulator 412 described above can be used.

[0081] The insulator 412 and the outer coating 414 can also contain additives such as flame retardants, flame retardant aids, antioxidants, lubricants, colorants, reflection imparting agents, concealing agents, processing stabilizers, plasticizers, etc. in addition to the above resin components as necessary.

[0082] As described above, the configuration of the internal wire of the cable manufactured by the cable manufacturing method of the present embodiment can be arbitrarily selected. Therefore, the cable manufactured by the cable manufacturing method of the present embodiment can include insulated wires having an internal conductor 411 and an insulator 412, and various other wires, together with or in place of the above coaxial cable. (Tension member) As shown in the cable 40 shown in FIG. 4, the internal wire 25 can also have a tension member 42 (tensile strength member). The tension member 42 can be configured to bear the tension and temperature expansion and contraction forces applied to the cable during cable manufacturing, laying, and after laying, so that no strain stress is applied to the covered wire or the like. (Suppressing wrap) As in the case of the cable 40 shown in FIG. 4, when the internal wire 25 has a plurality of covered wires, it can also have a suppressing wrap 43 that covers the plurality of covered wires.

[0083] The suppressing wrap 43 can cover the outer surfaces of the plurality of covered wires that the internal wire 25 has. By arranging the suppressing wrap 43, the twisted shape of the covered wires or the like constituting the internal wire 25 can be stably maintained.

[0084] As the suppressing wrap 43, for example, a paper tape, a non-woven fabric, or a resin tape such as polyester can be used. Also, the suppressing wrap 43 may be wound spirally along the longitudinal direction of the internal wire, or may be arranged longitudinally, that is, with the longitudinal direction of the suppressing paper along the longitudinal direction of the core. Also, the winding direction can be either Z-winding or S-winding. (Integrated shield layer) The cable 40 can also have an integrated shield layer 44. Since the integrated shield layer 44 has already been described, the description is omitted here. (Gap) The cable 40 can also have a gap 26 between the outer sheath 23 and the internal wire 25. Since the gap 26 has already been described, the description is omitted here.

[0085] According to the method for manufacturing the cable of the present embodiment described above, in the outer sheath forming step, an outer sheath is formed on the outer periphery of the temporary wire provided with the shield layer, and in the evaluation step, it can be evaluated whether the outer sheath has pinholes. Therefore, an outer sheath with suppressed pinholes and a cable including the outer sheath can be manufactured. As a result, a cable with excellent withstand voltage characteristics can be manufactured.

Explanation of reference numerals

[0086] 10, 11 Flowcharts S1 Outer Cover Formation Process S2 Evaluation Process S3 Removal Process S4 Insertion Process 20 Dashed Line 20A Outer Periphery of Dashed Line 21 Dummy Line 22 Shield Layer 22A Braided Structure 221 Metal Wire 222 Knot 200 Dashed Line with Outer Cover 23 Outer Cover 23A Inner Surface of Outer Cover D23 Inner Diameter of Outer Cover 24 Space 210, 40 Cable 25 Inner Wire D25 Outer Diameter of Inner Wire 26 Gap 31 Electrode 32 Inspection Device 33 Pinhole A Arrow 41 Coaxial Cable (Covered Wire) 411 Inner Conductor 412 Insulator 413 Shield Conductor 414 Outer Peripheral Cover 42 Tension Member 43 Restraining Coil 44 Comprehensive Shield Layer

Claims

1. An outer sheath forming step of forming an outer sheath on the outer periphery of a dummy wire having a dummy wire and a shield layer covering the outer surface of the dummy wire to obtain a dummy wire with an outer sheath; An evaluation step of installing an electrode on the outer surface of the outer sheath, measuring the current between the electrode and the shield layer while applying a voltage between the electrode and the shield layer, and evaluating the withstand voltage characteristics of the outer sheath; A manufacturing method of a cable having a removing step of removing the dummy wire.

2. The manufacturing method of the cable according to Claim 1, wherein the shield layer has a braided structure.

3. The manufacturing method of the cable according to Claim 1 or Claim 2, wherein during the evaluation step, the position on the outer surface of the outer sheath where the electrode contacts is changed along the longitudinal direction of the dummy wire with the outer sheath.

4. The manufacturing method of the cable according to any one of Claims 1 to 3, having an inserting step of inserting an internal wire into the space inside the outer sheath formed by removing the dummy wire after the removing step.

5. The manufacturing method of the cable according to Claim 4, having a gap between the internal wire and the inner surface of the outer sheath.

6. The manufacturing method of the cable according to Claim 4 or Claim 5, wherein the internal wire has a plurality of coated wires.

7. The manufacturing method of the cable according to Claim 6, wherein the coated wire includes a coaxial cable.

8. The manufacturing method of the cable according to any one of Claims 4 to 7, wherein the internal wire has an overall shield layer covering the outer surface.

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