JP2004234870A - Electromagnetic shield cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic shield cable capable of obtaining an excellent electromagnetic shielding property up to a high-voltage area with an induction voltage per unit length of 300V/km or higher, with excellent workability, aiming at cost reduction. <P>SOLUTION: Of the electromagnetic shielding cable made by forming a conductive layer 4 and an electromagnetic shielding layer 8 in turn on cable core wires 2, the electromagnetic shielding layer 8 is constituted by combining tape materials 10a, 10b of directional silicon steel and tape materials 12a, 12b of electromagnetic iron, with widths 10a, 10b of the tape materials of the directional silicon steel at 0.29 mm or more and 0.31 mm or less. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electromagnetic shielding cable.
[0002]
[Prior art]
In general, an electromagnetic shielding cable is conventionally used for a communication cable or the like laid in the vicinity of a power transmission line or the like because it is necessary to prevent the cable from being affected by an electromagnetic field from the power transmission line.
[0003]
A conventional electromagnetic shielding cable is configured such that a conductive layer and an electromagnetic shielding layer are sequentially formed on a cable core. As the conductive layer, a corrugated tube or the like made of low-resistance Al, Cu, or the like is used. As the electromagnetic shielding layer, a tape material made of directional silicon steel, which is a high magnetic permeability material, An iron tape material is used alone, and the tape material is wound around the conductive layer.
[0004]
By the way, there is a tendency that the voltage applied to the transmission line is increased more than before because the power transmission efficiency of the transmission line needs to be increased due to an increase in power demand in recent years. Accordingly, accordingly, there is a demand for a cable having high electromagnetic shielding characteristics even in an induced voltage per unit length of, for example, a high induced voltage region of 300 V / km or more.
[0005]
However, when the tape material made of directional silicon steel is used alone as the electromagnetic shielding layer, or when the tape material made of electromagnetic iron is used alone, the induced voltage per unit length is reduced. For example, in a high voltage range of 300 V / km or more, the electromagnetic shielding characteristics deteriorate.
[0006]
For this reason, an electromagnetic shielding cable in which a shielding layer is formed by combining tape materials of directional silicon steel and electromagnetic iron has been proposed (for example, see Patent Document 1).
[0007]
[Patent Document 1]
JP-A-6-187846 (page 2, FIG. 1)
[0008]
[Problems to be solved by the invention]
However, in an electromagnetic shielding cable in which a shielding layer is formed by combining tape materials of directional silicon steel and electromagnetic iron, if the thickness of the tape material of directional silicon steel is too large, a low-temperature manufacturing environment such as in winter. Then, during the winding work, the tape material cracks and it becomes difficult to work.On the other hand, if it is too thin, it must be wound around multiple layers to obtain a sufficient electromagnetic shielding effect, and the number of steps increases Become. In addition, since a rolling step is required to form a thin tape material of directional silicon steel, there is also a disadvantage that the unit price increases accordingly.
[0009]
In addition, there are many types of directional silicon steel, and in order to obtain good electromagnetic shielding characteristics in a wide induction voltage range, its selection is important.
[0010]
The present invention has been made in view of the above points, and provides good electromagnetic shielding characteristics up to a high voltage range of 300 V / km or more in an induced voltage per unit length, and has high workability. Another object of the present invention is to provide an electromagnetically shielded cable which is excellent in cost and reduces cost, and further provides an electromagnetically shielded cable using an optimal directional silicon steel.
[0011]
[Means for Solving the Problems]
The present invention is configured as follows to achieve the above object.
[0012]
That is, in the electromagnetic shielded cable according to the present invention, the conductive layer is provided on the outer periphery of the cable core wire, and the electromagnetic shield layer is provided on the outer periphery of the conductive layer. A tape material made of steel and a tape material made of electromagnetic iron are concentrically wound around the outer periphery of the conductive layer, and the thickness of the tape material made of directional silicon steel is set to 0.29 mm or more and 0.31 mm or less. Have been.
[0013]
According to the present invention, by forming the electromagnetic shielding layer by combining each tape material of directional silicon steel and electromagnetic iron, compared with the case of using each tape material alone, in a wide induction voltage range, The electromagnetic shielding properties have been greatly improved, and the thickness of the directional silicon steel tape material has been set to 0.29 mm or more and 0.31 mm or less. Even in a low-temperature manufacturing environment, the workability is improved without cracking of the tape material, and without having to be wound around a plurality of layers in order to obtain a sufficient electromagnetic shielding effect.
[0014]
In a preferred embodiment of the present invention, the tape material of the directional silicon steel has an iron loss (W _17/50 ) of 1.00 (W / kg) or less and a magnetic flux density (B ₈ ) of 1 or less. .80 (T) or more.
[0015]
_{Here, W 17/50} indicates that the frequency 50 Hz, a core loss at the maximum magnetic flux density 17T, _{B 8} shows that a magnetic flux density at a magnetizing force 800A / m.
[0016]
According to the present invention, there is provided a directional silicon steel having an iron loss (W _17/50 ) of 1.00 (W / kg) or less and a magnetic flux density (B ₈ ) of 1.80 (T) or more. By using a tape material, good electromagnetic shielding characteristics can be obtained over a wide voltage range from a low voltage range to a high voltage range.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0018]
(Embodiment 1)
FIG. 1 is a side view showing a configuration of an electromagnetic shielded cable according to one embodiment of the present invention.
[0019]
In the figure, 1 is an entire electromagnetic shielded cable, 2 is a cable core, 4 is a conductive layer made of a corrugated tube made of Al, 6 is a holding layer made of polyethylene tape, and 8 is an electromagnetic shielding layer. is there.
[0020]
The electromagnetic shielding layer 8 includes two tapes 10 a and 10 b made of directional silicon steel, which is a high magnetic permeability material, and two tapes 12 a and 12 b made of electromagnetic iron, on the outer periphery of the conductive layer 4. Are wound concentrically in this order.
[0021]
In this embodiment, in order to improve the winding workability of the two tape materials 10a and 10b made of directional silicon steel and reduce the cost, the thickness of these tape materials 10a and 10b is set to 0.28 mm or more. 0.32 mm or less, preferably 0.29 mm or more and 0.31 mm or less, specifically 0.30 mm, and the width is 33 mm.
[0022]
Furthermore, in this embodiment, the iron loss of the two tape materials 10a and 10b made of directional silicon steel is 1.00 (W / kg) or less at a frequency of 50 Hz and a maximum magnetic flux density of 17T, for example, 0. 95 (W / kg), and the magnetic flux density is 1.80 (T) or more, for example, 1.88 (T) at a magnetization force of 800 A / m.
[0023]
The two tape materials 10a and 10b made of the directional silicon steel are first wound in a gap on the press-winding layer 6, and then further formed of an electromagnetic iron having a thickness of 0.6 mm and a width of 33 mm. The two tape materials 12a and 12b are wound by a gap.
[0024]
Numeral 14 denotes a holding layer made of a non-woven tape, and numeral 16 denotes an anticorrosion layer made of polyethylene.
[0025]
The result of examining the relationship between the induced voltage V / km and the shielding coefficient λ for the electromagnetic shielding cable 1 having the above configuration is shown by the solid line in FIG. 2 (curve A in FIG. 2). In this case, the ground resistance is 4Ω / km, and the signal frequency is 50 Hz.
[0026]
When a tape material made of directional silicon steel, which is a high magnetic permeability material, is used alone as the electromagnetic shielding layer (the curve indicated by the broken line B in the drawing), the induced voltage per unit length is 300 V / km. In the low and medium voltage range to the extent, a relatively good shielding coefficient λ (= V ₀ / V) [where V ₀ is the voltage induced in the cable core of the electromagnetic shielding cable, and V is the unit length In the high voltage range where the induced voltage is 300 V / km or more, the shielding coefficient λ sharply increases, and the electromagnetic shielding characteristics deteriorate.
[0027]
In addition, when an electromagnetic iron tape material is used alone as the electromagnetic shielding layer (the curve indicated by the dashed-dotted line of the symbol C in the figure), the induced voltage per unit length is about 100 to 300 V / km. In the voltage range, a relatively good shielding coefficient λ is shown, but in the low voltage range where the induced voltage is 100 V / km or less and in the high voltage range where the induced voltage is 300 V / km or more, the shielding factor λ increases, and the electromagnetic shielding factor deteriorates. .
[0028]
On the other hand, in the present embodiment, as shown by the solid line A, the shielding coefficient λ is suppressed low over the entire region from the low voltage region to the high voltage region in the induced voltage per unit length. Thus, it is understood that the electromagnetic shielding characteristics are greatly improved.
[0029]
It is considered that this is not merely an additive effect of the characteristics of the directional silicon steel and the electromagnetic iron, but an electromagnetic region where the magnetic saturation is high while maintaining high magnetic permeability due to a synergistic effect of the two.
[0030]
Further, in this embodiment, since the thickness of the two tape materials 10a and 10b made of directional silicon steel is set to 0.30 mm, the winding of the tape materials 10a and 10b is performed in a low-temperature manufacturing environment such as winter. There is no occurrence of cracks during the operation, and it is not thin enough to require a rolling step. Therefore, the cost is relatively low, and the required electromagnetic shielding characteristics can be obtained without winding a plurality of layers.
[0031]
【The invention's effect】
As described above, according to the present invention, good electromagnetic shielding characteristics can be obtained over a wide voltage range where the induced voltage per unit length is from a low voltage range to a high voltage range. Therefore, in order to obtain the same electromagnetic shielding characteristics, a relatively large value of the grounding resistance is permissible, so that the cost for grounding work can be reduced as compared with the related art.
[0032]
Moreover, since the thickness of the tape material of the directional silicon steel is set to 0.29 to 0.31 mm, the workability is excellent and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a side view showing a structure of an electromagnetic shielded cable according to one embodiment of the present invention.
FIG. 2 is a characteristic diagram showing a relationship between an induced voltage per unit length and a shielding coefficient.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electromagnetic shielding cable 2 Cable core 4 Conductive layer 8 Electromagnetic shielding layers 10a, 10b Tape materials 12a, 12b made of directional silicon steel Tape materials made of electromagnetic iron

Claims (2)

A conductive layer is provided on the outer periphery of the cable core, and an electromagnetic shield layer is provided on the outer periphery of the conductive layer,
The electromagnetic shielding layer is formed by winding a tape material made of directional silicon steel and a tape material made of electromagnetic iron concentrically around the outer periphery of the conductive layer, and the thickness of the tape material made of directional silicon steel is 0. An electromagnetically shielded cable, which is set to be from 29 mm to 0.31 mm. The iron loss (W _17/50 ) of the tape material of the directional silicon steel is 1.00 (W / kg) or less, and the magnetic flux density (B ₈ ) is 1.80 (T) or more. Item 7. The electromagnetically shielded cable according to Item 1.

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