JP2019061776A - Multicore cable - Google Patents

Abstract

To provide a thin multicore cable excellent in twisting resistance.SOLUTION: A multicore cable includes: an aggregate 2 in which a plurality of wires 10, 30 are twisted together; shield layers (inner shield layer 4, outer shield layer 5) in which a plurality of metal strands 4a, 5a are spirally wound in two layers on an outer side of the aggregate 2; and a sheath 6 covering respective outer sides of the shield layers (inner shield layer 4, outer shield layer 5). The metal strands 4a, 5a are each a copper alloy wire with a tensile strength of 320-450 MPa, and breaking elongation of 10-15%.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a multicore cable.

  Patent Document 1 discloses a multicore cable in which a plurality of coaxial cables are bundled and a shield layer is formed around the bundle, and it is described that the shield layer may be double-folded sideways. There is.

JP 2011-228298 A

  Furthermore, a multi-core cable of small diameter with excellent torsional resistance is desired.

  An object of the present invention is to provide a small diameter multi-core cable excellent in torsion resistance.

The multicore cable according to one aspect of the present invention is
An assembly in which a plurality of electric wires are twisted together, a shield layer in which a plurality of metal wires are spirally wound in two layers outside the assembly, and a jacket covering the outside of the shield layer,
The metal wire is
It is a copper alloy wire having a tensile strength of 320 MPa to 450 MPa and a breaking elongation of 10% to 15%.

  According to the above-described invention, it is possible to provide a small diameter multi-core cable excellent in torsion resistance.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the structure of the multicore cable which concerns on this embodiment. It is a schematic diagram of a torsion test.

Description of an embodiment of the present invention
First, the embodiments of the present invention will be listed and described.
The multicore cable according to one aspect of the present invention is
(1) An assembly in which a plurality of electric wires are twisted together, a shield layer in which a plurality of metal wires are spirally wound in two layers outside the assembly, and an outer covering which covers the outside of the shield layer Equipped
The metal wire is
It is a copper alloy wire having a tensile strength of 320 MPa to 450 MPa and a breaking elongation of 10% to 15%.
According to the above-mentioned configuration, the thin metal wire of the shield layer is a thin copper wire having a tensile strength of 320 MPa or more and 450 MPa or less and an elongation at break of 10% or more and 15% or less. It can be a multicore cable of diameter.

(2) The metal layer-coated resin tape may be wound around the outer periphery of the assembly between the assembly and the shield layer.
According to the above configuration, the shielding effect is further improved by winding the resin tape with a metal layer around the outer periphery of the assembly.

(Details of the embodiment of the present invention)
Specific examples of multi-core cables according to embodiments of the present invention will be described below with reference to the drawings.
The present invention is not limited to these exemplifications, but is shown by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

  FIG. 1 shows a cross-sectional view perpendicular to the longitudinal direction of the multicore cable. As shown in FIG. 1, the multicore cable 1 includes an assembly 2 in which a plurality of electric wires are twisted, a restraining winding 3 covering the outer periphery of the assembly 2, and an inner shield layer 4 covering the outer periphery of the restraining winding 3. And an outer shield layer 5 covering the outer periphery of the inner shield layer 4 and an outer sheath 6 covering the outer periphery of the outer shield layer 5.

  The assembly 2 includes a plurality of wires (insulated wires 10 and coaxial wires 30). In the assembly 2 of this example, six insulated wires 10 are disposed inside the assembly 2, and eight coaxial wires 30 are disposed on the same circumference around the insulated wires 10. Furthermore, a filler 20 or the like is disposed at the center of the assembly 2 inside the six insulated wires 10. The insulated wire 10 can be used, for example, as a wire for supplying power or for low speed signals, and the coaxial wire 30 can be used, for example, as a wire for high speed transmission.

  The insulated wire 10 is, for example, a wire equivalent to # 22 to 26 to 30 of the AWG (American Wire Gauge) standard, in which the conductor 11 is covered with the jacket 12. The conductor 11 is made of, for example, a plurality of soft copper wires or copper alloy wires. The jacket 12 is made of, for example, a fluorine-based resin such as FEP, PFA, or ETFE (tetrafluoroethylene-ethylene copolymer).

  In addition, insulated wire 10 comrades may be twisted together, and may be gathered. The outer periphery of the twisted insulated wire 10 may be covered with a resin tape or the like. The insulated wire may be a mixture of wires of different thicknesses.

  The coaxial cable 30 has a coaxial structure in which the central conductor 31 is covered with the insulating layer 32, the outer conductor 33 is disposed on the outer periphery of the insulating layer 32, and the outer conductor 33 is covered with the outer sheath 34.

The central conductor 31 is formed by, for example, twisting a plurality of (seven in this example) soft copper wires. The cross-sectional area of the center conductor 31 is, for example, 0.01mm ² ~0.05mm ^2.
The insulating layer 32 is formed of, for example, a fluorine-based resin such as FEP (tetrafluoroethylene-hexafluoropropylene copolymer), PFA, or ETFE. The outer conductor 33 is configured such that, for example, a plurality of thin metal wires having an outer diameter of 0.03 mm to 0.05 mm are spirally wound (also referred to as horizontal winding) to the outside of the insulating layer 32. The jacket 34 is formed of, for example, a fluorine resin or a polyester tape.

  In a gap between the insulated wire 10 and the coaxial wire 30, for example, a tensile fiber 40 made of aramid fiber may be provided. The coaxial wire 30 and the insulated wire 10 may be collectively twisted together helically together with the tensile strength fiber 40. The central insulated wires may be twisted and assembled, and the outer layer coaxial wires may be twisted and assembled thereon.

  The holding winding 3 is formed of, for example, a resin tape such as a polyester tape such as PET or polyethylene tape, or a resin tape with a metal layer in which a metal layer such as copper or aluminum is adhered to or vapor deposited on a resin tape such as PET (polyethylene terephthalate). ing. For example, the thickness of the resin tape is about 2 μm to 10 μm, and the thickness of the metal layer is about 0.1 μm to 10 μm. The pressing winding 3 is wound around the outer periphery of the coaxial wire 30 so as to cover the assembled insulated wire 10 and the coaxial wire 30.

  The inner shield layer 4 is a shield layer disposed on the inner side of the two shield layers formed on the outer side of the holding winding 3 in order to shield the insulated wire 10 and the coaxial wire 30. The inner shield layer 4 is composed of a plurality of metal wires 4a.

  The plurality of metal wires 4a are wound around (in parallel with) the periphery of the pressure winding 3, for example, in a state of parallel winding (helical winding). The outer diameter of each metal wire 4a is 0.03 mm to 0.09 mm or less.

  The outer shield layer 5 is a shield layer disposed on the outside of the two shield layers formed on the outer side of the holding winding 3 in order to shield the insulated wire 10 and the coaxial wire 30. The outer shield layer 5 is composed of a plurality of metal wires 5a.

  The plurality of metal wires 5 a are, similarly to the metal wires 4 a of the inner shield layer 4, laterally wound (helically wound) in a state of being in parallel contact, for example. Moreover, the outer diameter of the metal wire 5a is the same as that of the metal wire 4a.

  In the present embodiment, in view of the results of the twisting test and the evaluation of the change in the outer diameter of the multicore cable in the examples described later, the metal wires 4a and 5a have a tensile strength of 320 MPa or more and 450 MPa or less, and a break. The copper alloy wire has an elongation of 10% to 15%.

  The direction of the lateral winding of the inner shield layer 4 and the direction of the lateral winding of the outer shield layer 5 may be the same direction or the opposite direction, but it is advantageous to set the same direction in the twisting test. is there.

  The jacket 6 is formed by extrusion-coating, for example, polyvinyl chloride or a polyolefin resin. The jacket 6 may be formed by laterally winding a resin tape such as PET. The outer diameter of the jacket 6 is, for example, 3.5 mm to 6 mm.

  The multicore cable 1 having such a configuration is suitable, for example, as a cable for USB interface.

  As described above, according to the multi-core cable 1, the metal wires 4a and 5a constituting the inner shield layer 4 and the outer shield layer 5 have tensile strength of 320 MPa to 450 MPa, and elongation at break of 10% to 15%. It is formed of the following copper alloy wire. Therefore, the inner shield layer 4 and the outer shield layer 5 can each be a shield layer having a good balance between tensile strength and breaking elongation, and the multi-core cable 1 excellent in torsion resistance even with a small diameter. You can get it.

  In addition, since the breaking elongation of the metal wires 4a and 5a is 10% or more and 15% or less, the problem that the metal wires 4a and 5a spirally wound around the outer periphery of the hold-down winding 3 is suppressed can be prevented can do. For this reason, it can be set as the multicore cable 1 which does not have variation in an outer diameter.

  In addition, by forming the shield layer into two layers of the inner shield layer 4 and the outer shield layer 5, the shield characteristics of the multicore cable 1 can be improved. The shielding effect can be further improved if the holding winding 3 made of resin tape with a metal layer is wound around the outer periphery of the assembly 2.

(Screw test and evaluation of outer diameter change)
The twist test of the multicore cable and the evaluation of the outer diameter change of the multicore cable in Examples and Comparative Examples will be described.
Similar to the multi-core cable 1 of the above-described embodiment, the winding is held around an assembly in which a plurality of (16) electric wires are collected, the two shield layers (inner shield layer and outer shield layer), and the outer No. 1 shown in Table 1 was obtained by sequentially stacking the objects 1 to No. A multicore cable satisfying the configuration 4 is produced. No. shown in Table 1 1 to No. In the multicore cable of 4, the material and characteristics (tensile strength, elongation at break) of the metal wire constituting the shield layer are changed. And the twist test was done on the following conditions about each produced multicore cable. Moreover, the outer diameter change of the jacket was evaluated on the following conditions about each multicore cable. No. 1 shows Example 1 of a multi-core cable, and No. 1 shows. 2-No. 4 shows comparative examples 1 to 3 of the multicore cable.

As shown in Table 1, no. In the multicore cable of 1, a tin-plated tin-copper alloy wire having a tensile strength of 400 MPa and an elongation at break of 12% was used as the metal wire constituting the shield layer.
No. In the multicore cable of 2, a tin-plated soft copper wire having a tensile strength of 250 MPa and an elongation at break of 15% was used as the metal wire constituting the shield layer.
No. In the multicore cable of 3, a silver-copper alloy wire having a tensile strength of 1000 MPa and an elongation at break of 3% was used as the metal wire constituting the shield layer.
No. In the multicore cable of 4, a tin-copper alloy wire (without softening treatment) having a tensile strength of 750 MPa and an elongation at break of 3% was used as the metal wire constituting the shield layer.
No. 1 to No. The lateral winding direction of the inner shield layer and the lateral winding direction of the outer shield layer were the same direction in all of No. 4 and the outer diameter of the metal wire was 0.05 mm.

(Twist test)
As shown in FIG. 2, the multicore cable C having a length of 2 m was vertically hung down, and the upper end and the lower end of the multicore cable C were gripped by the chucks 51, respectively. With the chuck 51 at the lower end fixed, the chuck 51 at the upper end was twisted at a speed of 30 rotations / minute from -360 ° to + 360 ° around the axis A of the multi-core cable C. After twisting 10,000 times, check the presence or absence of disconnection of all the coaxial wires that make up the multi-core cable C, pass if none of the center conductors are disconnected, or fail if any of the center conductors are disconnected And Each coaxial wire is a wire of the configuration described in the above embodiment.

(Evaluation of outer diameter change)
The manufactured No. 1 to No. The outer diameter of the jacket of 4 multicore cables was measured. The outer diameter of the jacket was 4.45 mm as a design value. In a 2 m long multi-core cable,
When there was a place where the outer diameter of the jacket increased by 1% or more from the design value (more than 4.49 mm), the evaluation of the outer diameter change was rejected.

(Result of twisting test)
No. 1, No. 3, No. In the multicore cable of 4, no breakage occurred in any of the center conductors after the twisting test. On the other hand, no. In the multicore cable of 2, a break occurred in the center conductor and the outer conductor after the twisting test. This is no. It is considered that the tensile strength (250 MPa) of the metal wire (tin-plated soft copper wire) constituting the shield layer 2 is weak. It is considered that the tin-plated soft copper wire of the shield layer is broken by the twisting test, and the outer conductor and the center conductor are broken by the twisting force applied to the coaxial wire. No. By setting the tensile strength of the metal wire forming the shield layer to 400 MPa as in 1, it has been confirmed that excellent resistance to twistability can be realized.

(Evaluation result of outer diameter change)
No. 1, No. In the multicore cable of No. 2, the outer diameter of the jacket was 4.49 mm or less, which was within the allowable range of the outer diameter change. On the other hand, no. 3, No. In the multicore cable of 4, the outer diameter of the jacket occurred at a location exceeding 4.49 mm. No. 3, No. In the multicore cable of 4, the outer diameter of the jacket was increased because the elongation of the metal wire forming the shield layer was small (the elongation at break was 3% in all cases). It is thought that it occurred. The term "lifting of metal wire" means that the metal wire of the inner shield layer spirally wound around the outer periphery of the holding winding or the metal wire of the outer shield layer spirally wound around the outer periphery of the inner shield layer is straight It means a phenomenon where it is stretched out in order to get back to the restraining winding or the inner shield layer. For this reason, even if the outer sheath of the shield layer is covered, the outer diameter of the outer sheath is considered to be increased by the amount of the floating because the outer sheath of the shield layer is covered on the floating metal wire. No. It was confirmed that the change in outer diameter of the jacket can be suppressed within the allowable range by setting the breaking elongation of the metal wire forming the shield layer to 15% or less as in 1.

  As shown in Table 1, the tensile strength and the elongation at break are in a contradictory relationship. 3, No. If it is increased as shown in 4, the elongation at break will be small, so the change in outer diameter will be rejected. On the other hand, the breaking elongation was No. If it is increased to 2 as the tensile strength decreases, the torsion test will fail.

  Based on the above-described results of the twisting test and the evaluation of the change in outer diameter, the metal wire constituting the shield layer is No. 1 A multicore cable (No. 5, No. 6) using a copper alloy wire having properties close to 1 (tensile strength, elongation at break) was produced. No. No. 5 (Example 2), no. No. 6 using the multicore cable of Example 6 (Example 3). 1 to No. The same twisting test as in 4 and the change in outer diameter were evaluated. The results are shown in Table 2.

  As shown in Table 2, no. 5, no. The multicore cable of 6 passed both the torsion test and the evaluation of the outer diameter change.

  From the above results, a copper alloy wire is used as the metal wire forming the shield layer, and the tensile strength of the copper alloy wire is 320 MPa or more and 450 MPa or less, and the breaking elongation is 10% or more and 15% or less. It has been confirmed that excellent torsional resistance can be obtained even with a small diameter. It has also been confirmed that the change in the outer diameter of the jacket can be reduced.

  While the invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. Further, the number, the position, the shape, and the like of the component members described above are not limited to the above embodiment, and can be changed to the number, the position, the shape, and the like suitable for practicing the present invention.

1: Multi-core cable 2: Assembly 3: Retaining winding 4: Inner shield layer 4a, 5a: Metal wire 5: Outer shield layer 6: Outer sheath 10: Insulated electric wire 11, 21: Conductor 12, 22: Outer sheath 20 : Filler 30: Coaxial electric wire 31: Center conductor 32: Insulating layer 33: Outer conductor 34: Outer sheath 40: Tensile fiber

Claims (2)

An assembly in which a plurality of electric wires are twisted together, a shield layer in which a plurality of metal wires are spirally wound in two layers outside the assembly, and a jacket covering the outside of the shield layer,
The metal wire is
Copper alloy wire with a tensile strength of 320 MPa or more and 450 MPa or less, and an elongation at break of 10% or more and 15% or less,
Multicore cable. Between the assembly and the shield layer, a resin tape with a metal layer wound around the periphery of the assembly,
A multicore cable according to claim 1.

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