JPH06150726A - High pressure flat cable - Google Patents

Abstract

PURPOSE:To prevent affecting to the shielding copper tape of a shielding layer by readily absorbing expansion and contraction of an insulating material layer due to a heat cycle when a flat cable is used to transmit power at high voltages. CONSTITUTION:A flat cable 1 comprises a plurality of aligned cable conductors 2 covered with a relatively thick inner semiconducting layer 3, with an insulating material layer 4 molded around the outer periphery of the layer 3 by extrusion or the like. The internal semiconductor layer 3 and the insulating material layer 4 are both of approximately elliptic cross-section and a shielding copper tape 7 serving as a shielding layer and a holding tape layer 8 are formed along the outer periphery of the insulating material layer and the outermost periphery is covered with a sheath 9 so as to form the cable of approximately rectangular outer form. Even while expansion and contraction of the insulating material layer are caused by the heat cycle of the flat cable, the expansion and contraction have no effect on the shielding copper tape and so no gap is formed in the shielding copper tape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a structure in which a plurality of conductors are arranged adjacent to each other in parallel,
The present invention relates to a flat cable which is covered with an insulating layer and a shielding layer and has a rectangular outer peripheral shape.
The present invention relates to a high-voltage flat cable provided with an insulating layer having a substantially elliptical cross section so as not to be affected by a heat cycle when a high-voltage current is passed.

[0002]

CV used as a cable for electric power
In the case of cables and the like, for example, Shoukai 60-1360
As disclosed in Japanese Patent Publication No. 08, etc., an insulator layer is arranged around a stranded wire of a copper wire having a circular cross section with an internal semiconductive layer interposed therebetween, and a sheath is provided on the outer periphery thereof with a shielding layer interposed therebetween. Things are used. As shown in the conventional example, the cable having a circular cross section is arranged in a cavern or other power feeding path provided in the underground, and the voltage and the power feeding capacity, depending on the diameter of the conductor, The thickness of the insulating coating and the like are set.

However, the cable having a round cross section as shown in the above-mentioned conventional example is difficult to be used because it is difficult to bend it with a small curvature when it is used for a power feeding path inside a building, for example. There is a problem. Therefore,
As a means for forming a power feeding path inside a building, it has been practiced to use a flat cable as disclosed in Japanese Patent Laid-Open No. 23016/1990. In the conventional flat cable, a plurality of conductors are arranged adjacent to each other in parallel, the plurality of conductors are covered with an inner semiconductive layer, and an insulator layer and a shielding layer are provided on the outer periphery of the inner semiconductive layer. And are arranged and covered with a sheath,
Generally, the structure shown in FIG. 4 is used.

The flat cable 1a shown in FIG.
In the above, the cable conductors 2 arranged in parallel are covered with a thin inner semiconductive layer 3, and an outer circumference thereof is covered with an insulating layer having an oval cross section. The conductive layer 5 and the shielding layer 6 are arranged and covered with a sheath 9 having a rectangular cross section. The cable conductor 2 is made by arranging four or six copper wires made of twisted wires in parallel, and thinly winding an inner semiconductive layer 3 made of a carbon material on the surface of the cable conductor 2. There is. The insulating layer 4 covering the outer peripheral portion of the cable conductor 2 is made of a material such as polyethylene, and the outer semiconductive layer 5 made of a carbon material is formed on the outer peripheral portion of the insulating layer 4. Is placed, and the outermost part is
The sheath 9 made of vinyl chloride or the like is covered.

With the flat cable constructed as described above, it is possible to construct a power feeding system utilizing the characteristics of low impedance. For example, by constructing the system with a thickness of about 20 mm and a width of about 60 mm, 600
It can pass a large current of about A and is used as a power supply line inside a building instead of a cable with a round cross section. Furthermore, since the cable 1a can be easily bent in the thickness direction, it can be applied to a complicated bending portion in a building or a power feeding system of a plant, and the power feeding system can be easily configured. It is possible to exhibit the advantages such as being possible, and in particular, the low-voltage power supply system tends to be frequently used instead of the bus duct.

[0006]

However, although the flat cable as shown in FIG. 4 has been used in a low voltage power supply system of 600V or the like in many cases, it is not used in a high voltage power transmission system. However, flat cables that can exhibit the bending characteristics described above are expected to be used in high-voltage power transmission systems in the future. ,
It is required to change the constituent materials such as the inner semiconductive layer, the outer semiconductive layer, and the shielding layer. Further, when a high voltage current of several thousand V is applied to the flat cable, it is necessary to form the shielding layer using a shielding copper tape and a pressing tape layer, and the shielding copper tape is wound around to form the shielding layer. If so, the heat cycle is expected to have a different effect than in the case of a cable with a round cross section.

That is, when the flat cable is used for high-voltage power transmission, the heat cycle of the flat cable increases the degree of expansion and contraction of the insulating layer in the flat portion of the cable, and the insulating layer expands and contracts. As a result, the action of expanding and contracting the shielding copper tape is added, and a problem occurs that a gap is formed between the shielding copper tape and the outer peripheral portion of the insulating layer. The above-mentioned problems do not appear remarkably in round cables, but in flat cables, it can be considered that the influence of expansion and contraction appears particularly in the central part of the flat part, and the insulation The expansion of the layer has a greater effect on the shielding copper tape. When a gap is formed in the shielding copper tape portion, corona discharge or the like occurs, which causes a problem that the electrical characteristics of the flat cable are impaired.

In addition to the above problems, the conventional inner semiconductive layer is formed by coating the surface of the cable conductor with a thin carbon layer. There is a problem that the conductive layer is damaged and the flatness of the cable conductor is impaired. In the high voltage power transmission system, if the parallelism of the cable conductors is disturbed, there is a problem that the low impedance characteristics cannot be exhibited well, and the electrical characteristics of the flat cable are also hindered. Therefore, in order to solve the above-mentioned problems, for example, as shown in Japanese Utility Model Application Laid-Open No. 60-136008, a semi-conductive tape material forming an external semi-conductive layer is used which has high strength. It is conceivable to use it to configure. In the above-mentioned conventional example, the tightening action of the tape with respect to the insulating layer is favorably maintained, and the holding force that opposes the expansion and contraction action of the insulating layer due to the heat cycle can be exhibited. However, the use of the structure of the external semiconductive layer as described above can be easily applied to a cable having a circular cross section, but cannot be easily applied to a flat cable. There is.

[0009]

An object of the present invention is to solve the problem in constructing a high voltage power transmission system using a flat cable, and to provide an inner semiconductive layer for covering a cable conductor, an insulating layer and a covering member for the outer peripheral portion thereof. , With an elliptical cross section,
When the insulator layer expands and contracts due to the effect of heat cycle,
It is an object of the present invention to provide a high-voltage flat cable capable of preventing a gap or the like from being formed around the shielding copper tape.

[0010]

According to the present invention, a plurality of conductors are arranged adjacent to each other in parallel, the plurality of conductors are covered with an inner semiconductive layer, and the outer periphery of the inner semiconductive layer is covered. The present invention relates to a flat cable in which an insulating layer, an outer semiconductive layer and a shielding layer are arranged and covered with a sheath. In the flat cable of the present invention, an insulating layer that covers the outer peripheral portion of the inner semiconductive layer, an outer semiconductive layer, and a shielding layer constituted by a shielding copper tape and a pressing tape layer have a substantially elliptical cross section. It has a rectangular cross section and is covered with a sheath having a rectangular cross section. Further, in the high-voltage flat cable of the present invention, the insulating layer and the shielding layer formed on the outer periphery of the inner semiconductive layer are configured to have a cross-sectional shape similar to the outer peripheral shape of the inner semiconductive layer, It is also possible to provide by coating with a sheath having a contoured outer shape.

As described above, a plurality of conductors arranged in parallel are covered with an insulating layer having an elliptical cross section so that the insulating layer expands under the influence of heat cycles. Even when the insulating layer shrinks, the shielding copper tape wrapped around the insulating layer can easily follow the expansion and contraction action of the insulating layer. Then, a gap or the like is not formed between the insulating layer and the shielding copper tape, corona discharge does not occur inside the cable, and the electrical characteristics of the flat cable may be impaired. To be prevented. Further, the flat cable of the present invention can exhibit bending characteristics similar to those of the low-voltage flat cable, and wiring can be easily performed according to an arbitrary power feeding system. It can be simplified.

[0012]

The high-voltage flat cable of the present invention will be described with reference to the examples shown in the drawings. The flat cable 1 shown in FIG. 1 is a conductor 2 in which four copper wires are put together.
Are arranged in parallel in a state of being adjacent to each other, and the inner semiconductive layer 3 is formed by extrusion or the like around the cable conductor 2. The inner semiconductive layer 3 has an oval cross section, and is formed by integrally covering a plurality of cable conductors with the inner semiconductive layer so that the planarity of the plurality of cable conductors can be maintained. ing. As shown in the figure, the insulator layer 4 covering the inner semiconductive layer has a substantially elliptical outer shape,
A material obtained by extruding a material such as polyethylene is used. Further, an outer semiconductive layer 5 is arranged on the outer peripheral portion of the insulator layer 4, and the outer semiconductive layer 5 is made of a resin material mixed with carbon, like the inner semiconductive layer 3. The inner semiconductive layer 3, the insulator layer 4, and the outer semiconductive layer 5 can be integrally formed by extrusion molding.

Further, the shielding layer 6 arranged on the outer peripheral portion of the outer semiconductive layer 5 is the same as in the case of a general high voltage cable.
The shielding copper tape 7 and the pressing tape layer 8 are stacked and wound. Further, the outer periphery of the flat cable is covered with a sheath 9 such as vinyl chloride by extrusion or the like so that the flat cable has a substantially rectangular outer shape. In the flat cable of the present invention, the two semiconducting layers, the inner semiconducting layer 3 and the outer semiconducting layer 5, may be formed by winding a cloth tape or the like having conductivity.

In the flat cable 1 of the present invention constructed as described above, when the bending action is applied to the cable, the inner semiconductive layer 3 formed thickly around the cable conductor is It exerts the effect of holding the cable conductor in a state where it can maintain its flatness. Further, the elliptical insulator layer 4 tries to deform in a state in which the bending action is applied to the cable, but the pressure at which the insulator layer deforms is due to the pressure in the center portion in the width direction of the insulator layer. Since it is absorbed in the large diameter portion, it does not have a great influence on the shielding layer arranged on the outer peripheral portion. Since the outer peripheral shape of the insulating layer does not change significantly, the shielding copper tape 7 or the like forming the shielding layer is not deformed, and a gap is formed between the shielding copper tape and the insulating layer. It will not happen. In addition to the bending action applied to the flat cable, even if the expansion and contraction action of the insulating layer is given by the heat cycle when the flat cable is energized, the insulating layer has a thermal expansion and contraction action due to the shape of the insulating layer. It is prevented from being absorbed inside the body layer and affecting the shielding layer.

In addition to constructing the flat cable having the cross-sectional shape as shown in FIG. 1, in the present invention, as shown in FIG. 2, the cross-sectional shape of the inner semiconductive layer is made substantially elliptical. You can also do it. In the flat cable 1 shown in FIG. 2, the three layers of the inner semiconductive layer 3, the insulator layer 4 and the outer semiconductive layer 5 are integrally formed by extrusion molding with respect to the state where the cable conductors 2 are arranged. By forming the outer shape of each layer into an elliptical shape, it is possible to easily perform integral molding. Further, also in the flat cable 1 shown in FIG. 2, as in the case of the flat cable of FIG. 1, the shielding layer disposed on the outer peripheral portion of the outer semiconductive layer 5 is the shielding copper tape 7 and the pressing tape layer 8. Can be formed in a rolled state. Then, the outermost peripheral portion thereof is covered with a sheath 9 made of vinyl chloride or the like by extrusion molding or the like to form a flat cable having a substantially rectangular outer peripheral shape.

Apart from the flat cable 1 shown in FIG. 2, the flat cable 1 of the present invention can also be constructed as shown in FIG. In the cable 1 shown in FIG. 3, the shielding layer arranged on the outer peripheral portion of the outer semiconductive layer 5 is wound around the shielding copper tape 7 and the pressing tape layer 8 in the same manner as in each of the embodiments. State and configure.
Then, a sheath 9 made of vinyl chloride or the like is provided on the outermost periphery thereof.
Can be coated by extrusion molding or the like to form a flat cable having a substantially oval outer peripheral shape. Also,
In the cable 1 shown in FIG. 3, the shielding layer 6 is covered with a sheath 9 having a uniform thickness so that the entire cross-sectional shape is elliptical. The outer shape of the sheath can be configured to be an arbitrary shape so that the cable can be easily handled. The outer thickness of the entire cable is set by arbitrarily setting the thickness of the sheath. It is also possible.

In the flat cable of the present invention, by constituting each layer as described above, the action of expansion and contraction of the insulating layer due to heat cycle is absorbed by the expansion and contraction of the insulating layer itself and the internal semiconductive layer. You can And
It is possible to prevent a minute gap or the like from being formed between the insulating layer and the shielding copper tape due to the effect of heat cycle on the shielding layer covering the outside of the insulating layer. Therefore, when using the high-voltage flat cable of the present invention, corona discharge or the like occurs in the insulating layer portion,
It is possible to use the high-voltage flat cable in a stable state without causing insulation failure.

In the flat cable 1 shown in the embodiment of the present invention, the thickness of the conductors forming the cable conductor, the number of the cable conductors, etc. can be arbitrarily set as in the case of a general cable. Is. The thicknesses of the inner semiconductive layer and the insulating layer formed around the cable conductor can be set arbitrarily according to the current carrying capacity.
Further, as the material forming the inner semiconductive layer, the insulating layer, and the sheath, the same materials as in the case of the conventional round cable for high voltage power transmission can be used, and those materials are extruded and molded. Can cover the cable conductor. Further, the inner semiconductive layer and the outer semiconductive layer used in the high-voltage flat cable can also be configured by winding a conductive tape,
It is naturally possible to form them together with the insulating layer by extrusion.

[0019]

As described above, the high-voltage flat cable of the present invention has a structure in which a plurality of conductors are arranged in parallel, and the periphery thereof is covered with an insulating layer having an elliptical cross section. Even if the insulating layer expands and contracts due to the effect of heat cycles, the shielding copper tape wrapped around the insulating layer can easily follow the expansion and contraction action of the insulating layer. Then, a gap or the like is not formed between the insulating layer and the shielding copper tape, corona discharge does not occur inside the cable, and the electrical characteristics of the flat cable may be impaired. To be prevented. Further, the flat cable of the present invention can exhibit bending characteristics similar to those of the low-voltage flat cable, and wiring can be easily performed according to an arbitrary power feeding system. It can be simplified.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of a flat cable of the present invention.

FIG. 2 is a cross-sectional view showing the configuration of another embodiment of the flat cable of the present invention.

FIG. 3 is a cross-sectional view when the outer shape of the cable of the present invention is formed into an elliptical shape.

FIG. 4 is a cross-sectional view showing a configuration of a conventional flat cable.

[Explanation of symbols] 1 flat cable, 2 cable conductor, 3
Inner semiconductive layer, 4 Insulator layer, 5 Outer semiconductive layer, 6 Shielding layer, 7 Shielding copper tape, 8
Holding tape layer, 9 sheath.

Claims (2)

[Claims] 1. A plurality of conductors are arranged adjacent to each other in parallel, the plurality of conductors are covered with an inner semiconductive layer, and an insulator layer and an outer semiconductive layer are formed on the outer periphery of the inner semiconductive layer. In a flat cable formed by disposing a shielding layer and covering with a sheath, an insulating layer covering the outer peripheral portion of the inner semiconductive layer, a shielding layer composed of a shielding copper tape and a pressing tape layer, A high-voltage flat cable comprising a member having an elliptical cross section and provided with a sheath having a rectangular cross section. 2. A plurality of conductors are arranged adjacent to each other in parallel, the plurality of conductors are covered with an inner semiconductive layer, and the inner semiconductive layer covering the plurality of conductors arranged in parallel is substantially It is configured as a member having an elliptical cross section, and the insulating layer and the outer semiconductive layer and the shielding layer formed on the outer periphery of the inner semiconductive layer have a cross sectional shape similar to the outer peripheral shape of the inner semiconductive layer. A high-voltage flat cable characterized in that it is provided with a sheathed sheath having an elliptical outer shape.