JP2013251101A - Electric wire for high-frequency current - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric wire for a high-frequency current that is low in cost and that has a good connection workability.SOLUTION: An electric wire Pis obtained by rolling a copper tape as a core material 1 in a width direction into a pipe shape, twisting and arranging copper conductors 2 in a spiral shape to an outer periphery of the pipe-like core material 1, and coating the periphery of the respective conductors 2 by an insulator 3 made of vinyl chloride. Since the conductors are provided to the outer periphery of the pipe-like core material in a spiral shape, this electric wire has a large outer peripheral diameter configured by the respective conductors in the spiral shape, a small reactance, and a small impedance. Since a total cross sectional area of the whole conductors is smaller than that of one having a central conductor regardless of such the small impedance, the cost becomes low. In addition, since a work of removing the core material is unnecessary at pressure-bonding, like in the case that a non-conductive material made of a low-softening point resin and the like is used as the core material, a good connection workability can be obtained.

Description

  The present invention relates to a high-frequency current wire such as a lightning surge wire used in a lightning damage countermeasure system.

In recent years, it has become a network society, and many devices such as communication devices are connected to the network. On the other hand, in recent years, lightning strikes frequently occur due to weather changes, and when lightning strikes occur in the network, the devices connected to the network are damaged.
For this reason, conventionally, as shown in FIG. 12, the power circuit from the commercial frequency power supply D to the load device F has a lightning surge wire P having a resistance component R and a reactance component L and a lightning arrester SPD (Surge Protective Device). In many cases, a lightning damage countermeasure system is constructed. In this lightning damage countermeasure system, since lightning surge is high frequency, the lightning surge electric wire P is selected from electric wires having a relatively large conductor outer diameter compared to electric wires used for commercial frequencies. Such a wire is used as a high-frequency current wire.

  As shown in FIG. 13, when power is supplied from the charging coil C to an electric vehicle (EV) (not shown) or the like, a high frequency power source E is used as the power source, and a power supply cable to the charging coil C is used as the power supply cable. Since a high frequency flows, the cable P is expected to use the high-frequency current wire as a wire having a relatively large conductor outer diameter as compared with a wire used for a commercial frequency. In addition, "high frequency" here refers generally to 1 kHz or more.

  By the way, in order to flow a surge current smoothly, the impedance of the electric wire is required to be low. The impedance of the wire at low frequencies is almost determined by the conductor resistance. Therefore, for low frequency applications, the wire used must have a conductor cross-sectional area corresponding to the required impedance (in the case of a single wire, the single-wire cross-sectional area, in the case of a stranded wire, the total cross-sectional area of the entire stranded wire, the same shall apply hereinafter). It is used.

On the other hand, in applications in which high-frequency current flows, such as lightning surge, noise, high-frequency power supply, and inverter power supply, the impedance of the wire is greatly affected by reactance, and decreases as the reactance decreases. This reactance decreases as the conductor outer diameter increases (in the case of a single wire, the outer diameter of the single wire, and in the case of a stranded wire, the outer peripheral diameter of the entire stranded wire, the same applies hereinafter). For this reason, conventionally, electric wires having a large conductor outer diameter (outer diameter) have been selected and used.
At this time, since the cross-sectional area of general conductors such as single wires, concentric stranded wires, and aggregated stranded wires is also increased, the amount of conductors used is increased, and the cost of electric wires is high.

JP 2002-208318 A

Under the above conditions, by inserting a non-conductive core material such as natural fiber, plastic, rubber, etc. at the center, and providing a conductor on the outer circumference (outer periphery), the conductor outer diameter can be increased while suppressing the conductor cross-sectional area. A "diameter conductor" is used (see Patent Document 1 FIGS. 1 and 2).
Since these core materials are different in nature from conductors, crimping (or compression, hereinafter simply referred to as “crimping”) of terminals (or sleeves, hereinafter simply referred to as terminals, or connections) together with conductors. If this is done, the performance of these connections will be degraded during use. Specifically, since the cross-sectional area of the crimped part after crimping is constant and the core occupies a part of the cross-sectional area, when the tensile strength of the core is significantly lower than that of the conductor, the tensile strength of the connecting part is reduced. . In general, when a current flows through the electric wire, conductor heat is generated. When the heat generation temperature exceeds the softening point of the core material, the softened core material expands as the residual stress of conductors and terminals and the self-expansion pressure during softening (many substances change from solid to liquid) ) Partly irreversibly leaches out of the crimping part. Thereafter, when the conductor temperature is lowered, the residual stress at the crimping portion is reduced, and the contact resistance is increased or the tensile strength is lowered.

  In order to avoid this, it is necessary to unwind the conductor once to expose the core material, cut and remove the conductor, then cut and remove the conductor, and then shape the conductor and connect the terminal. There is. As described above, since handling of the electric wire using the enlarged conductor is troublesome, the electric wire using the enlarged conductor is used only for a very special purpose such as a lightning rod lowering wire or a rock blasting device cable, such as an SPD grounding wire. As usual, IV electric wires (vinyl insulated wires for indoor wiring, see FIG. 14) are used.

  This invention makes it a subject to provide the electric wire for high frequency currents which is cheap and has good workability | operativity under the above actual condition.

In order to achieve the above object, the present invention has a configuration in which a plurality of conductors are arranged on the outer peripheral surface of a cylindrical (pipe-shaped) core material.
Even if the total cross-sectional area of each conductor is the same, the outer diameter formed by each conductor around the core material is increased because the electric wire having this configuration has the same total cross-sectional area. It becomes an electric wire with a small reactance in an application in which a high-frequency current flows such as a high-frequency power source or an inverter power source.

In this configuration, the cylindrical core material is not only a pipe from the beginning, but also a tape is attached vertically and gradually formed into a pipe shape through a forming guide, or a wire or / and tape is a spiral tube. It can be obtained by winding it in a spiral shape into a pipe shape.
Further, a tape or a wire may be further wound in a spiral shape on a pipe-like one gradually passing through the molding guide.
An electric wire for high-frequency current using such a pipe-like core material has a flexibility because the tape can absorb the bending at the overlapping portion of the tape when the tape is vertically attached to form a pipe shape. What is wound in a spiral shape into a pipe shape has flexibility due to a winding spring effect. Further, a pipe or a tape or wire wound in a spiral shape is more resistant to bending.

Various materials such as metals, non-metals, and resins can be adopted as the material of the core material. However, considering the influence of heat generated by the conductor, a metal that is heat resistant and does not soften easily compared to a resin is preferable. If there is, it is not necessary to once untwist the conductor at the time of terminal treatment and then perform the work of shaping the conductor, so that it is not necessary to cut and remove the core material and the processing workability is improved.
As the metal, copper, aluminum, brass, iron, stainless steel and the like can be adopted, but it is preferable to use the same material as the conductor. This is because the same material is unlikely to change in the conductivity of the terminal portion during terminal processing.

The plurality of conductors arranged on the outer peripheral surface of the core material may be one layer, but may be a plurality of layers. At that time, the conductors of the respective layers can be twisted together. Moreover, the outer periphery of the plurality of conductors can be covered with insulation.
Further, a plurality of the insulation-coated wires can be twisted and the outer peripheral surface thereof can be covered to provide a sheath.
These high-frequency current wires can be used in the same manner as in the past. In particular, they can be used for lightning surges or for power supply to electric vehicles (EVs).

  In the present invention, since the core material is formed in a pipe shape as described above, it is possible to provide a high-frequency current electric wire with a small reactance without increasing the cross-sectional area of the conductor, and the terminal processing is easy. Become.

Sectional drawing of one Embodiment of the electric wire for high frequency currents of this invention Sectional view of the other embodiment Sectional view of the other embodiment Sectional view of the other embodiment Sectional view of the other embodiment Sectional view of the other embodiment Sectional view of the other embodiment Sectional view of the other embodiment Sectional view of the other embodiment Sectional view of the other embodiment (A) is a tensile test explanatory diagram, (b) is a resistance value measurement test explanatory diagram Schematic diagram of lightning protection system Schematic diagram of high-frequency power supply circuit Cross section of conventional example Cross-sectional view of another conventional example Cross-sectional view of another conventional example Cross-sectional view of another conventional example Cross-sectional view of another conventional example

It shows the each embodiment of the lightning surge wires P is one of the high frequency current wires _(P 0 to P ₈₎ according to the present invention in FIGS. 1-9, the structure (Example 1 to _{9: P} 0 ~ P ₈ ) is as shown in Table 1.

The lightning surge wire P _{0 in} FIG. 1 is formed into a pipe-shaped core material 1 by gradually adding a copper tape and passing through a forming guide to form a pipe-shaped core material 1 and twisting a copper conductor 2 around the pipe-shaped core material 1. While being densely arranged in the circumferential direction (in a spiral),
A lightning surge electric wire P _{1 in} FIG. 2 is obtained by covering the lightning surge electric wire P ₀ (around each conductor 2) with an insulator 3 made of vinyl chloride (PVC).
Lightning surge wires P ₂ in FIG. 3 is obtained in the insulator 3 of the electric wire P ₁ in place of the PVC adopted flame retardant polyethylene (flame PE).
The lightning surge wire P _{3 in} FIG. 4 uses tin-plated copper wire 2 instead of the conductor of the wire P ₁ , twists 88 wires, and uses rubber for the outer insulator 3. It is a thing.
A lightning surge electric wire P _{4 in} FIG. 5 employs a fluororesin for the insulator 3 of the electric wire P ₁ .
The lightning surge electric wire P _{5 in} FIG. 6 is provided with a brass wire 1 a in a spiral cylindrical shape inside the copper tape core material 1, and a copper conductor 2 is arranged while twisting the outer periphery of the core material 1. The periphery is covered with a urethane insulator 3.
Lightning surge wires P ₆ in FIG. 7, the aluminum tube core 1 adopted (aluminum pipe), that the outer periphery of the core 1 is disposed while twisted aluminum conductors 2, polyamide around its respective conductors 2 The insulator 3 is covered.

The lightning surge wire P _{7 in} FIG. 8 is made of crosslinked polyethylene (XLPE) as the insulator 3 of the lightning surge wire P ₁ , and the two wires P ₁ ′ are twisted to cover the outer periphery of the PVC sheath 4. Cable.
Lightning surge wires P ₈ in FIG. 9, the wire P ₄ for the lightning surge, using aluminum to the conductor 2, twisting the four wires for lightning surge P _{4 ',} the copper tape on the outer periphery thereof This is a cable in which a shielding layer 5 is wound and wound, and then the outer periphery thereof is covered with a urethane sheath 4.

As comparative examples, lightning surge wires P _{12 to} P ₁₆ shown in FIGS. 14 to 18 were manufactured. Its lightning surge wires P ₁₂ in FIG. 14, 'twisted seven, the outer periphery of PVC insulation 3' copper conductor 2 is obtained by coating with.
Lightning surge wires P ₁₃ shown in FIG. 15, twisting 'copper conductor 2 to the outer periphery of the' XLPE string made cylindrical core 1 is obtained by coating the outer periphery with PVC made of insulating material 3 '.

The lightning surge wire P _{14 in} FIG. 16 is made by twisting seven copper conductors 2 ′, twisting two outer wires P ₁₂ ′ covered with an insulator 3 ″ made of XLPE, and forming PVC on the outer periphery. A cable covering a sheath 4 '. It is.
Lightning surge wires P in FIG. _{17. 15,} twisting 'copper conductor 2 to the outer periphery of the' XLPE string made cylindrical core member 1, 2 of the outer periphery of XLPE made of insulating material 3 '' covered with the wire P _{13 '} The book is twisted and the outer periphery thereof is covered with a PVC sheath 4 '.
Lightning surge wires P ₁₆ in FIG. 18, _'twisted four, shielding layer 5 by winding a copper tape on the outer circumference' the wire P ₁₃ after providing the, the PVC-made sheath 4 'on the outer periphery It is a coated cable.

Table 2 shows the results of measuring the “conductor cross-sectional area indicating the material cost” and “workability during terminal processing” of Examples 1 to 9 and Comparative Examples 1 to 5.
The conductor cross-sectional area indicating the material cost is the same as the conductor outer diameter (6.0 mmΦ in Table 1), and the conductor has a small core cross-sectional area. ) ”, And the larger ones were marked with“ × (high material cost) ”.
The workability at the time of terminal processing is that the commercially available crimp terminal 10 shown in FIG. 11 is crimped to the conductors 2 and 2 ′ of each electric wire P, and when the core material 1 ′ is removed in the workability, The workability was set to “× (defect)”, and when the conductor 2 was simply caulked, it was set to “◯ (good)”.
In all the comprehensive evaluations, “◯” is “○”, and even one “×” is “×”. In the tensile test shown in FIG. 11A and the resistance value test between both end terminals 10 and 10 shown in FIG. 11B, there was no difference between each example and the comparative example.

From these experimental results, each of Examples 1 to 9 (electric wires P _{0 to} P ₈ ) obtained “◯” in both tests, while Comparative Examples 1 to 5 (electric wires P _{12 to} P ₁₆ ) It becomes "x" in either one of the experiments, and it can be understood that the electric wire according to the present invention is excellent.

In addition, each of the electric wires P (P _{0 to} P ₈ ) is individually easy to manufacture and inexpensive because the electric wires P ₀ and P ₁ of Examples 1 and 2 have a general configuration. Thus, the electric wire P _{2 of} Example 3 is able to secure insulation with a thin thickness compared to PVC, so that the flame-resistant PE forming the insulator 3 can reduce the thickness of the insulator 3, and the entire wire P ₂ The diameter can be reduced.
The wire P ₃ of Example 4, as with the P _2, on which can thin the diameter of the electric wire, it is assumed rich in flexibility, the wire P ₄ of Example 5, the fluororesin constituting the insulator 3 because it can ensure insulation with a thin thickness in comparison with the rubber, and can reduce the thickness of the insulator 3 can further reduce the diameter of the entire cable P _4.
Since the wire P ₅ of Example 6, it is assumed that hardly deformed by urethane insulator 3 with a spiral brass wire 1a and mechanical strength, wire P ₆ of Example 7, the conductor 3 is aluminum The weight is reduced, and the polyamide insulator 3 has high mechanical strength.
Since the electric wire (cable) P ₇ of the eighth embodiment has a general configuration like the electric wire P ₁ , the electric wire (cable) P ₈ of the ninth embodiment is easy to manufacture and inexpensive. The effect of the conductor material of the electric wire P _{6 and} the insulating material of the electric wire P ₄ , that is, the advantage of being lightweight and having a small diameter.

Each wire P ₀ to P ₈ has been a wire for lightning surge, the power supply cable P to an electric vehicle (EV) or the like as shown in FIG. 13, FIG. 8, it can be employed such as those shown in FIG. 9 Of course.

In addition, each embodiment shown in FIGS. 1-9 is an illustration, and as long as the effect of this invention is exhibited, for example, the conductor 2 does not need to be densely arranged in the electric wire circumferential direction, Materials such as the core material 1, the conductor 2, the insulator 3, and the sheath 4 are arbitrary. Furthermore, the pipe-shaped core material 1 can be formed in various ways. For example, a tape or wire is spirally wound like a spiral tube to form a pipe, or both the tape and the wire are spiraled together. It can be wound into a spiral like a tube to form a pipe. In these cases, a tape or a wire can be wound in a spiral shape around the circular pipe shape (see FIG. 6). At this time, the pipe shape and the spiral shape may be either inside or outside (in FIG. 6, the spiral shape is located inside the pipe shape).
A plurality of conductors 2 arranged in the outer circumferential surface of the core member 1 may be a single layer, but plural layers, for example, can be a wire P ₉ or the like of two layers shown in FIG. 10, and more than three layers.
Thus, it is needless to say that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined not by the above-mentioned meaning but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

1,1 'core 2, 2' conductors 3, 3 'insulators 4, 4' sheaths _P, electric wire P 0 to P ₉ lightning surge (cable)

Claims (9)

  An electric wire for high-frequency current, wherein a plurality of conductors (2) are disposed on the outer peripheral surface of a cylindrical core material (1).   The electric wire for high-frequency current according to claim 1, wherein the core material (1) is a tape-shaped member formed into a pipe shape.   The high-frequency current wire according to claim 1 or 2, wherein the core material (1) is a metal.   The high-frequency current wire according to claim 1 or 2, wherein the core material (1) and the conductor (2) are made of the same material.   The plurality of conductors (2) disposed on the outer peripheral surface of the cylindrical core material (1) have a plurality of layers in the radial direction of the core material (1). Or a high-frequency current wire according to any one of the above.   The high-frequency current wire according to any one of claims 1 to 5, wherein an outer periphery of the plurality of conductors (2) is covered with an insulating coating (3).   A high-frequency current wire, wherein a plurality of high-frequency current wires according to claim 6 are twisted together and a sheath (4) is provided covering the outer peripheral surface thereof.   The electric wire for high-frequency current according to any one of claims 1 to 7, wherein the electric wire is for lightning surge.   The high-frequency current wire according to claim 7, wherein the high-frequency current wire is for power feeding.

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