JP2019179594A - cable - Google Patents

Abstract

To provide a cable having less resistance increase and improving inflection resistance.SOLUTION: A cable 1 comprises: a twisted conductor wire 10 having one center conductor wire 11 arranged on a center, six intermediate conductor wires 12 wound to the center conductor wire 11 in a spiral state, twelve outside conductor wires 13 wound to the six intermediate conductor wires 12 in a spiral state; and an insulation coating layer 20 coating the twisted conductor wire 10. Tension strength for a unit area of the intermediate conductor wire 12 is larger than that for a unit area of the outside conductor wire 13.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cable, and more particularly to a cable excellent in bending resistance.

  Cables used in hinge portions of personal computer and mobile phones that can be opened and closed by connecting a drive portion of an industrial robot or a display portion and a keyboard by a hinge are required to have resistance to repeated bending. The twisted conductor for a mobile cable described in Patent Document 1 below has a configuration in which a reinforced stranded wire is arranged at the center and one or more layers of stranded wires are arranged around it. With such a configuration, the twisted conductor for a moving cable is improved in resistance to bending.

Japanese Utility Model Publication No. 57-101418

  However, even when the mobile cable twisted conductor described in Patent Document 1 is used for the cable, it is difficult to obtain sufficient bending resistance. In general, it is effective to use a metal having a high tensile strength in order to improve the bending resistance of the cable. However, generally, a metal having a high tensile strength is an alloy. For this reason, when a metal with high tensile strength is used for the stranded wire, the resistance of the cable tends to increase.

  In view of the above, an object of the present invention is to provide a cable that has little increase in resistance and can improve bending resistance.

  The cable according to the present invention includes one central conductor disposed at the center, six intermediate conductors spirally wound around the central conductor, and twelve outer spirals wound around the six intermediate conductors. A conductive wire, and an insulation coating layer that covers the twisted conductive wire, and the tensile strength per unit area of the intermediate conductive wire is larger than the tensile strength per unit area of the outer conductive wire It is a feature.

  Compared to the case where the tensile strength per unit area of the outer conductor and the tensile strength of the intermediate conductor are the same as each other, the tensile strength of the intermediate conductor is greater than the tensile strength of the outer conductor, thereby improving the bending resistance of the cable. Can be made. In addition, as described above, a metal having a high tensile strength per unit area is generally made of an alloy. Therefore, a metal having a higher tensile strength per unit area tends to have a higher resistance. However, in the cable of the present invention, since the tensile strength per unit area of the intermediate conductor, which is smaller than that of the outer conductor, is large, the increase in the resistance of the cable is small.

  Further, the tensile strength per unit area of the central conductor may be equal to or higher than the tensile strength per unit area of the intermediate conductor.

  By setting the tensile strength per unit area of the central conducting wire to be equal to or higher than the tensile strength per unit area of the intermediate conducting wire, it is possible to further improve the cable bending resistance while suppressing an increase in the resistance of the cable.

  Alternatively, the tensile strength per unit area of the central conducting wire may be smaller than the tensile strength per unit area of the intermediate conducting wire.

  In this case, the tensile strength per unit area of the central conductor may be greater than or equal to the tensile strength per unit area of the outer conductor.

  When the tensile strength per unit area of the central conducting wire is smaller than the tensile strength per unit area of the intermediate conducting wire, the tensile strength per unit area of the central conducting wire is equal to or higher than the tensile strength per unit area of the outer conducting wire, Compared with the case where the tensile strength per unit area of the central conductor is smaller than the tensile strength per unit area of the outer conductor, it is possible to further improve the bending resistance of the cable while suppressing an increase in the resistance of the cable.

Further, the intermediate conducting wire and the outer conducting wire may be spirally wound in opposite rotation directions.

  Compared with the case where the intermediate conductor and the outer conductor are wound in the same direction, the overall undulation is less and a straighter cable can be obtained.

  The cable preferably further includes a shield that surrounds the outer peripheral surface of the insulating coating layer, and an outer insulating coating layer that covers the outer peripheral surface of the shield.

  By adopting such a configuration, it is possible to provide a coaxial cable that has little increase in resistance and can improve bending resistance.

  As described above, according to the present invention, it is possible to provide a cable that has a small increase in resistance and can improve bending resistance.

It is a figure which shows the cable which concerns on embodiment of this invention. It is sectional drawing perpendicular | vertical to the longitudinal direction of the cable shown in FIG. It is a modification of the cable of FIG. It is a figure which shows a coaxial cable. It is a figure which shows the mode of the test of a bending tolerance.

  Hereinafter, the form for carrying out the cable concerning the present invention is illustrated with an accompanying drawing. The embodiments exemplified below are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. The present invention can be modified and improved from the following embodiments without departing from the spirit of the present invention.

  FIG. 1 is a diagram showing a cable according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view perpendicular to the longitudinal direction of the cable shown in FIG.

  As shown in FIGS. 1 and 2, the cable 1 of the present embodiment includes a stranded conductor 10 and an insulating coating layer 20 that covers the outer peripheral surface of the stranded conductor 10.

  The stranded conductor 10 includes one central conductor 11, six intermediate conductors 12, and twelve outer conductors 13. The center conducting wire 11 is disposed along the longitudinal direction of the cable 1. Each intermediate conducting wire 12 is arranged in parallel with each other, and is wound spirally around the outer peripheral surface of the central conducting wire 11. The outer conductors 13 are arranged in parallel with each other, and are spirally wound around the outer peripheral surfaces of the six intermediate conductors 12 wound around the outer peripheral surface of the central conductor 11. In this embodiment, the intermediate conducting wire 12 and the outer conducting wire 13 are reversely twisted and wound spirally in mutually opposite rotation directions. In addition, the twist pitch of the intermediate conductor 12 is preferably smaller than the twist pitch of the outer conductor 13.

  Moreover, in this embodiment, the center conducting wire 11, each intermediate conducting wire 12, and each outer conducting wire 13 are formed of metal wires having the same thickness. The central conducting wire 11, each intermediate conducting wire 12, and each outer conducting wire 13 may have different thicknesses.

  As a metal which forms each wire of these center conducting wire 11, each intermediate conducting wire 12, and each outside conducting wire 13, copper and a copper alloy can be mentioned, for example. Examples of the copper alloy include copper added with about 0.5% to 8% silver.

  Further, the tensile strength per unit area of the intermediate conducting wire 12 is larger than the tensile strength per unit area of the outer conducting wire 13. In the following description, when simply referred to as tensile strength, it means tensile strength per unit area. In order to obtain such a configuration, for example, the main component of the metal constituting the intermediate conductor 12 and the main component of the metal constituting the outer conductor 13 are the same, and the metal constituting the intermediate conductor 12 is It is mentioned that more metal additives are added than the metal which comprises the outer side conducting wire 13. FIG. In this case, the metal additive is preferably a material having a higher tensile strength than the main component of the metal. An example of the main component of the metal is copper, and an example of the metal additive is silver. In this case, an example in which the intermediate conducting wire 12 is made of an alloy of 97% copper and 3% silver and the outer conducting wire 13 is made of an alloy of 99% copper and 1% silver can be given.

  Further, the tensile strength of the central conducting wire 11 may be the same as the tensile strength per unit area of the intermediate conducting wire 12. In this case, the center conductor 11 and the intermediate conductor 12 may be made of the same metal.

  Alternatively, the tensile strength of the central conducting wire 11 may be made smaller than the tensile strength of the intermediate conducting wire 12. In order to achieve such a configuration, for example, the main component of the metal constituting the intermediate conductor 12 and the main component of the metal constituting the central conductor 11 are the same as each other, It is mentioned that more metal additives are added than the metal which comprises the center conducting wire 11. FIG. In this case, the tensile strength of the central conductor 11 may be equal to or higher than the tensile strength per unit area of the outer conductor 13. In order to achieve such a configuration, for example, the main component of the metal constituting the central conductor 11, the main component of the metal constituting the intermediate conductor 12, and the main component of the metal constituting the outer conductor 13 are made the same. The metal constituting the central conductor 11 has a metal addition greater than the amount of metal additive added to the metal constituting the outer conductor 13 and less than the amount of metal additive added to the metal constituting the intermediate conductor 12. The thing is added. In addition, when the tensile strength of the center conducting wire 11 is made smaller than the tensile strength of the intermediate conducting wire 12 as described above, the tensile strength of the center conducting wire 11 may be made smaller than the tensile strength per unit area of the outer conducting wire 13. . In order to obtain such a configuration, for example, the main component of the metal that constitutes the central conductor 11 and the main component of the metal that constitutes the outer conductor 13 are mutually the same, It is mentioned that a metal additive less than the metal which comprises the outer side conducting wire 13 is added.

  Alternatively, the tensile strength of the central conducting wire 11 may be made larger than the tensile strength per unit area of the intermediate conducting wire 12. In order to achieve such a configuration, for example, the main component of the metal that constitutes the central conductor 11 and the main component of the metal that constitutes the intermediate conductor 12 are the same as each other, It may be mentioned that more metal additives are added than the metal constituting the intermediate conductor 12.

  The insulating coating layer 20 is formed by extruding a thermoplastic resin. Examples of such thermoplastic resins include fluorine such as polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and tetrafluoroethylene-ethylene copolymer (ETFE). Resins can be mentioned.

  As described above, the cable 1 of the present embodiment includes one central conducting wire 11 disposed at the center, six intermediate conducting wires 12 spirally wound around the central conducting wire 11, and six intermediate conducting wires. A twisted conductor 10 having twelve outer conductors 13 wound spirally, and an insulating coating layer 20 that covers the twisted conductor 10 are provided. Further, the tensile strength per unit area of the intermediate conducting wire 12 is larger than the tensile strength per unit area of the outer conducting wire 13. For this reason, compared with the case where the tensile strength of the outer conducting wire 13 and the tensile strength of the intermediate conducting wire 12 are the same as each other, the bending strength of the cable 1 is increased because the tensile strength of the intermediate conducting wire 12 is larger than the tensile strength of the outer conducting wire 13. Resistance can be improved. Further, since a metal having a high tensile strength is generally made of an alloy, the metal having a higher tensile strength tends to have a higher resistance. However, in the cable 1 of the present invention, since the tensile strength of the intermediate conductor 12 having a smaller number than that of the outer conductor 13 is large, the resistance of the cable 1 is not increased.

  As mentioned above, although this invention was demonstrated to the example for embodiment, this invention is not limited to these.

  For example, in the said embodiment, the intermediate | middle conducting wire 12 and the outer side conducting wire 13 are made into the reverse twist wound helically by the mutually opposite rotation direction. However, the present invention is not limited to this. FIG. 3 is a modification of the cable of FIG. In the description of FIG. 3, the same or equivalent components as those of the above-described embodiment will be omitted unless otherwise described with the same reference numerals. As shown in FIG. 3, in the cable 1 of the present invention, the intermediate conductor 12 and the outer conductor 13 may be forward twisted spirally wound in the same rotational direction.

  Moreover, although the cable 1 which consists of the twisted conducting wire 10 and the insulation coating layer 20 was demonstrated in the said embodiment, this invention is applicable not only to this but the coaxial cable which is an example of a cable, for example. . FIG. 4 is a diagram illustrating a coaxial cable. In the description of FIG. 4, the same or equivalent components as those in the above embodiment are denoted by the same reference numerals, and redundant description is omitted unless specifically described. As shown in FIG. 4, the coaxial cable 2 includes the stranded conductor 10 and the insulating coating layer 20 described in the above embodiment, a shield 30 disposed around the outer peripheral surface of the insulating coating layer 20, and the outer peripheral surface of the shield 30. And an outer insulating coating layer 40 for coating.

  The shield 30 includes, for example, a braid in which conductive wires such as copper and tin-plated copper are knitted, a laterally wound shield in which the conductive wires are spirally wound, a metal foil made of metal such as aluminum, and a braid and metal foil. And a laminated body of a horizontally wound shield and a metal foil. In FIG. 5, a braid is illustrated as the shield 30.

  The outer insulating coating layer 40 is also called a sheath and is made of a thermoplastic resin. Examples of such thermoplastic resins include fluorine such as polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PTA), and tetrafluoroethylene-ethylene copolymer (ETFE). Resins can be mentioned.

  In such a coaxial cable 2, the stranded conductor 10 is generally used as a signal line, an electric signal is transmitted to the stranded conductor 10, and the shield 30 is grounded. Further, in such a coaxial cable 2, it can be understood that the same cable 1 as that of the above embodiment is disposed inside the shield 30. Therefore, the coaxial cable 2 has little increase in resistance and can improve bending resistance.

  Hereinafter, the content of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

(Comparative Example 1)
A cable having the same structure as the cable 1 shown in FIGS. 1 and 2 was prepared. The central conductor, the intermediate conductor, and the outer conductor of this cable were made of an alloy of 99% copper and 1% silver, the tensile strength per unit area was approximately 600 MPa, and the diameter was 20 μm. The covering layer was made of PFA, and the outer diameter of the cable was 0.15 mm.

(Comparative Example 2)
A cable similar to the cable of Comparative Example 1 was prepared except that the central conductor was made of an alloy of 97% copper and 3% silver and the tensile strength per unit area was approximately 900 MPa.

(Comparative Example 3)
A cable similar to the cable of Comparative Example 1 except that the center conductor, the intermediate conductor, and the outer conductor are made of an alloy of 97% copper and 3% silver, respectively, and the tensile strength per unit area is approximately 900 MPa, respectively. Prepared.

Example 1
A cable similar to the cable of Comparative Example 1 was prepared except that the center conductor and the intermediate conductor were made of an alloy of 97% copper and 3% silver, and the tensile strength per unit area was approximately 900 MPa.

(Example 2)
A cable similar to the cable of Comparative Example 1 was prepared except that the intermediate conductor was composed of an alloy of 97% copper and 3% silver and the tensile strength per unit area was approximately 900 MPa.

  Next, the bending resistance of these cables was tested. FIG. 5 is a diagram showing a state of a bending resistance test. As shown in FIG. 5, the test apparatus 50 includes a flat plate 51 and a pair of rod bodies 52 erected vertically on the flat plate 51. The diameter of each rod 52 was 4 mm, and the interval between each rod 52 was slightly wider than 0.15 mm, which is the outer diameter of the prepared cable.

  In FIG. 5, the cable prepared in the comparative example and the example is a cable 1. The cable 1 is fixed between a pair of rod bodies 52, bent 90 degrees in one direction along one rod body 52, and then along the other rod body 52, as indicated by a broken line in FIG. And bent 90 degrees in the other direction. This bending was repeated until it was disconnected. The disconnection here refers to a state where the cable becomes non-conductive.

  Moreover, the electrical resistance in 20 degreeC of each cable was measured.

Table 1 shows the number of bends until the cables of the comparative examples and examples are disconnected, and the electrical resistance of the cables.

  In Example 1, the tensile strength per unit area of the central conductor and the intermediate conductor is larger than that of Comparative Example 1, and the tensile strength per unit area of the intermediate conductor is larger than that of Comparative Example 2, and On the other hand, the tensile strength of the outer conductor is small. Further, Example 2 has a higher tensile strength per unit area of the intermediate conductor than that of Comparative Example 1, and has a lower tensile strength per unit area of the center conductor than that of Comparative Example 2, and has a unit area of the intermediate conductor. The tensile strength per hit is large, and the tensile strength of the central conductor and the outer conductor is small compared to Comparative Example 3. As is apparent from Table 1, the cables of Example 1 and Example 2 were found to have higher bending resistance than the cables of Comparative Example 1, Comparative Example 2, and Comparative Example 3. Moreover, when Example 1 and Example 2 were compared, the result of Example 1 was higher in flexibility. Furthermore, when Comparative Example 1 and Comparative Example 2 were compared, Comparative Example 2 was higher in flexibility. Therefore, it is considered that the bending resistance of the cable can be further improved while suppressing an increase in the resistance of the cable by setting the tensile strength per unit area of the central conductor to be equal to or higher than the tensile strength per unit area of the intermediate conductor. .

  Moreover, although the electric resistance of the cables of Example 1 and Example 2 increased compared with the cables of Comparative Example 1 and Comparative Example 2, there was no problem as a cable as long as it increased to this extent. It was found that the cable No. 2 showed little increase in resistance. Therefore, according to the cable of the present invention, the resistance increase is small and the bending resistance can be improved.

  According to the present invention, a cable that can increase resistance to bending with little increase in resistance is provided, and a drive part of an industrial robot, a personal computer or a mobile phone that can be opened and closed by connecting a display part and a keyboard with a hinge. It can be used in the field of

DESCRIPTION OF SYMBOLS 1 ... Cable 2 ... Coaxial cable 10 ... Twist lead 11 ... Center lead 12 ... Intermediate lead 13 ... Outer lead 20 ... Insulation coating layer 30 ... Shield 40 ...・ Outer insulation coating layer

Claims (6)

A twisted wire comprising one central conductor wire arranged in the center, six intermediate conductor wires spirally wound around the central conductor wire, and twelve outer conductor wires spirally wound around the six intermediate conductor wires. Lead wires,
An insulating coating layer covering the twisted conductor;
With
The cable according to claim 1, wherein a tensile strength per unit area of the intermediate conducting wire is larger than a tensile strength per unit area of the outer conducting wire. The cable according to claim 1, wherein a tensile strength per unit area of the central conductor is equal to or higher than a tensile strength per unit area of the intermediate conductor. The cable according to claim 1, wherein the tensile strength per unit area of the central conductor is smaller than the tensile strength per unit area of the intermediate conductor. The cable according to claim 3, wherein a tensile strength per unit area of the central conductor is equal to or higher than a tensile strength per unit area of the outer conductor. The cable according to any one of claims 1 to 4, wherein the intermediate conducting wire and the outer conducting wire are spirally wound in opposite directions of rotation. A shield surrounding the outer peripheral surface of the insulating coating layer;
An outer insulating coating layer covering the outer peripheral surface of the shield;
The cable according to any one of claims 1 to 5, further comprising:

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