JP2012221739A - Cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight cable which can suppress high-frequency noise, facilitates connection to an external terminal, has flexibility and sufficiently secures insulation properties between conductors.SOLUTION: A cable includes a plurality of stripes of insulation core wires 10, and a sheath 30 covering them. The insulation core wire 10 includes: a conductor 12; a film 22 (first insulator); a resistor thin film 24 (resistor) disposed via the film 22 in the longitudinal direction of the conductor 12; and a second insulator 14 covering them.

Description

  The present invention relates to a cable used as a drive cable (such as a motor drive cable) that connects an inverter and a load (such as a motor).

  In the motor drive control system in which the drive of the motor is controlled by the inverter, the rise time of the control pulse is recently advanced and the voltage is increased. For this reason, there is a problem that surge noise is generated due to reflection resonance at different impedances, the signal quality in the cable connecting the inverter and the motor is lowered, and the drive control signal is not transmitted accurately. In addition, malfunction of peripheral devices is a problem due to radiation noise generated from the cable due to surge noise.

As motor drive cables in which high-frequency noise such as surge noise and radiation noise is suppressed, for example, the following are proposed.
(1) A reflection type surge suppression cable that combines a main line connected to a motor and an auxiliary line having one end branched from the motor-side main line and the other end opened (Patent Document 1).
(2) A motor drive cable in which a current return line connected to the ground is adjacent to the main line connected to the motor (Patent Document 2).

In the cable (1), in order to suppress a high-frequency noise component, a material having a large resistance and a large complex permeability that increases resistance and / or inductance is plated on the auxiliary wire. And it is supposed that the noise current reflected by the motor is led to an auxiliary line to suppress surge noise.
However, since the noise current generated due to impedance mismatch between the inverter and the motor is reflected also in the auxiliary lines having different impedances, the noise current cannot be sufficiently introduced into the auxiliary line. Therefore, the suppression effect of surge noise is small.

In the cable (2), the cross-sectional area of the current return line is larger than 1/3 of the cross-sectional area of the main line in order to exhibit a function as a sufficient return path. The low loop inductance effectively returns unnecessary high-frequency leakage current to the inverter, thereby preventing malfunction of peripheral devices.
However, even if the return path is formed with a low impedance, reflection occurs as in the case of the cable (1). Therefore, it is difficult to return the high-frequency leakage current to the inverter. Reflected by different inverters. For this reason, there was no sufficient effect for suppressing surge noise.

  In addition, the cable is required to be lightweight and flexible. However, in the cables (1) and (2), since the cross-sectional area of the auxiliary line or the current return line is large, the weight reduction and the flexibility are reduced. Not satisfied. Furthermore, when connecting the cable to a device such as a motor, in addition to connecting the main line to the external terminal, the auxiliary line and the like must also be connected to the external terminal, and the connection work is complicated.

In addition, the following are known as cables / cables other than the motor drive cable, in which radiation noise is suppressed.
(3) An electromagnetic wave shielding material in which a conductive adhesive layer is laminated on one side of a film with a conductive thin film covered with an electric wire or the like (Patent Document 3).
(4) A communication cable in which a core bundle obtained by bundling a plurality of insulated core pairs is covered with a covering material in which a conductor layer and / or a resistor layer and a magnetic layer are laminated (Patent Document 4).

However, when the electromagnetic shielding material (3) is covered with a cable having a plurality of insulated core wires, the electromagnetic shield material has conductivity, so that the conductor of the insulated core wire and the insulating core wire adjacent thereto are Insulation with the conductor cannot be secured sufficiently.
Also in the cable (4), since the covering material in which the conductor layer and / or the resistor layer and the magnetic layer are laminated has conductivity, the conductor of the insulated core pair and the insulation adjacent thereto are provided. It becomes impossible to ensure sufficient insulation between the conductors of the core pair.

Japanese Patent No. 4131686 International Publication No. 2008/041708 Pamphlet JP 2003-258480 A JP 2005-259385 A

  The present invention provides a cable that can sufficiently suppress high-frequency noise, can be easily connected to an external terminal, is lightweight, has flexibility, and has sufficient insulation between conductors.

  The cable of the present invention is a cable having a plurality of insulating core wires and a sheath covering them, the insulating core wires being along the conductor, the first insulator, and the longitudinal direction of the conductor. It has the resistor arrange | positioned through the said 1st insulator, and the 2nd insulator which covers these, It is characterized by the above-mentioned.

The cross section of the conductor is preferably not a perfect circle.
When the cross section of the conductor is a perfect circle, the resistor preferably has a portion that does not follow the outer periphery of a virtual concentric cylinder that is coaxial with the conductor.

Preferably, the first insulator is a film, and the resistor is a resistor thin film formed on the surface of the film.
The distance from the conductor to the portion of the resistor closest to the conductor is preferably 1 to 100 μm.

The surface resistance of the resistor is preferably 1 to 1000Ω.
The width of the resistor is preferably 0.5 to 4 times the diameter of the conductor.
The thickness of the resistor is preferably 5 to 100 nm.

  The cable of the present invention can sufficiently suppress high-frequency noise, can be easily connected to an external terminal, is lightweight, has flexibility, and has sufficient insulation between conductors.

It is sectional drawing which shows an example of the cable of this invention. It is sectional drawing which shows the other example of the cable of this invention. It is sectional drawing which shows the other example of the cable of this invention. It is sectional drawing which shows the other example of the cable of this invention. It is sectional drawing which shows the other example of the cable of this invention. It is sectional drawing which shows the other example of the cable of this invention. It is sectional drawing which shows an example of the positional relationship of the conductor and resistor in the cable of this invention. It is sectional drawing which shows the other example of the positional relationship of the conductor and resistor in the cable of this invention. It is the schematic which shows an example of the motor drive control system provided with the cable of this invention. It is a figure explaining the evaluation method of a cable. 6 is a graph showing attenuation characteristics of high-frequency energy of the cable of Example 1.

<Cable>
FIG. 1 is a cross-sectional view showing a first embodiment of the cable of the present invention. The cable 1 has four insulating core wires 10 having a substantially circular cross section and a sheath 30 surrounding the insulating core wires 10. The insulation core wire 10 includes a conductor 12 having a true circular cross section; a resistor thin film 24 (resistor) is formed on one surface of the film 22 (first insulator), and the conductor 12 is in contact with the conductor 12 on the film 22 side. A resistor film 20 having a C-shaped cross section disposed along the longitudinal direction; and a resistor film so that the resistor thin film 24 has a portion not along the outer periphery of a virtual concentric cylinder (described later) coaxial with the conductor 12. An inclusion 16 that arranges 20 into a C-shaped section and arranges the insulating core wire 10 into a substantially circular section; and a second insulator 14 that covers these inclusions.

  FIG. 2 is a cross-sectional view showing a second embodiment of the cable of the present invention. The cable 2 includes four insulated core wires 10 having a substantially sectoral cross section disposed so that arc-shaped portions of the cross section form a circle, and a sheath 30 surrounding these insulated core wires 10. The insulation core wire 10 includes a conductor 12 having a true circular cross section; a resistor thin film 24 (resistor) is formed on one surface of the film 22 (first insulator), and the conductor 12 is in contact with the conductor 12 on the film 22 side. A resistor film 20 having an L-shaped cross section disposed along the longitudinal direction; and a resistor film so that the resistor thin film 24 has a portion that does not follow the outer periphery of a virtual concentric cylinder (described later) coaxial with the conductor 12. An inclusion 16 that arranges 20 into an L-shaped section and arranges the insulating core wire 10 into a substantially sectoral shape; and a second insulator 14 that covers these inclusions.

  FIG. 3 is a cross-sectional view showing a third embodiment of the cable of the present invention. The cable 3 includes four insulating core wires 10 having a substantially circular cross section and a sheath 30 surrounding the insulating core wires 10. The insulation core wire 10 includes a star-shaped (cross-shaped) conductor 12 having four protrusions in cross section; a resistor thin film 24 (resistor) formed on one surface of a film 22 (first insulator); A resistor film 20 arranged along the longitudinal direction of the conductor 12 so that the side thereof is in contact with the protrusion of the conductor 12; an inclusion 16 for adjusting the resistor film 20 and the insulating core wire 10 to have a substantially circular cross section; 2 insulators 14.

  FIG. 4 is a cross-sectional view showing a fourth embodiment of the cable of the present invention. The cable 4 includes four insulating core wires 10 having a substantially circular cross section and a sheath 30 surrounding the insulating core wires 10. The insulation core wire 10 includes a conductor 12 having a triangular cross section; a conductor thin film 24 (resistor) formed on one side of the film 22 (first insulator), and the conductor 12 so that the film 22 side is in contact with the corner of the conductor 12. A resistor film 20 disposed along the longitudinal direction of the resistor; an inclusion 16 for adjusting the resistor film 20 and the insulating core wire 10 to have a substantially circular cross section; and a second insulator 14 covering them.

  FIG. 5 is a cross-sectional view showing a fifth embodiment of the cable of the present invention. The cable 5 includes four insulating core wires 10 having a substantially circular cross section and a sheath 30 surrounding the insulating core wires 10. The insulating core wire 10 includes a conductor 12 made of a stranded wire having a substantially circular cross section in which a plurality of strands 18 are bundled; a resistor thin film 24 (resistor) formed on one surface of a film 22 (first insulator); The resistor film 20 is disposed along the longitudinal direction of the conductor 12 so that the film 22 side is in contact with the conductor 12 and covers the conductor 12, and the second insulator 14 covers these.

  FIG. 6 is a sectional view showing a sixth embodiment of the cable of the present invention. The cable 6 has four insulated core wires 10 having a substantially sectoral cross section arranged so that arc-shaped portions of the cross section form a circle, and a sheath 30 surrounding these insulated core wires 10. The insulating core wire 10 includes a conductor 12 made of a stranded wire having a substantially triangular cross section in which a plurality of strands 18 are bundled; a resistor thin film 24 (resistor) formed on one side of a film 22 (first insulator); A resistor film 20 having an L-shaped cross section disposed along the longitudinal direction of the conductor 12 so that the film 22 side is in contact with the conductor 12; the resistor film 20 is arranged in an L-shaped cross section; Inclusions 16 to be arranged; and a second insulator 14 covering them.

(Insulated core)
The insulating core wire 10 is obtained by covering the conductor 12, the resistor film 20, and the inclusion 16 as necessary with the second insulator.
The insulating core wire 10 is manufactured by extruding the conductor 12 and the resistor film 20 together with the material (resin etc.) of the second insulator 14 and the material of the inclusion 16 (resin etc.) as necessary.
In addition, the number of the insulation core wires in the cable is not limited to 4 as illustrated, but may be 2 to 3 or 5 or more.

(conductor)
As the material of the conductor 12, a highly conductive metal (such as copper or aluminum) is preferable. The conductor 12 may be a single wire made by drawing out a die having an opening such as a circle, or may be a stranded wire in which a plurality of strands 18 are bundled and compressed. From this point, a stranded wire is preferable.

The cross-sectional shape of the conductor 12 may be a perfect circle (FIGS. 1 and 2) or a shape other than a perfect circle (FIGS. 3 to 6), and is preferably not a perfect circle for the following reasons. .
Since the high-frequency noise current flows concentrated on the surface of the conductor 12 due to the skin effect, the protrusion of the conductor 12 (for example, a ridge (edge) where two surfaces of the polygon intersect, a protrusion on the uneven surface of the stranded wire) High-frequency noise current flows in a concentrated manner at both ends of the major axis of the ellipse. Therefore, electromagnetic field fluctuations occur around the protrusions. When this electromagnetic field fluctuation, that is, a change in the electromagnetic field vector occurs, an eddy current is generated in the resistor thin film 24 disposed opposite to the conductor 12 so as to prevent the change of the electromagnetic field vector (the principle of electromagnetic induction). It is considered that energy is consumed by the resistance loss due to the resistor thin film 24, and high-frequency noise (surge noise) flowing through the conductor 12 is efficiently attenuated.

  Examples of shapes other than a perfect circle include polygons (triangles, quadrilaterals, pentagons, hexagons, stars, crosses, etc.), ellipses, and cross sections of stranded wires. In the case of a stranded wire that has been compressed into a substantially circular cross section, the cross section can be regarded as a perfect circle, but in the present invention, it is regarded as having an unevenness on the outer periphery (not a perfect circle).

(Resistor film)
The resistor film 20 is obtained by forming a resistor thin film 24 on one side (both sides if necessary) of a film 22.

The resistor film 20 physically deposits the material of the resistor thin film 24 (metal, conductive ceramics, carbon, etc.) on the surface of the film 22, or contains metal, conductive ceramics, carbon, etc. on the surface of the film 22. Manufactured by applying paste.
The resistor film is not limited to the resistor film 20 in the illustrated example, and is a molded sheet obtained by molding a material in which metal, conductive ceramics, carbon, etc. are dispersed in an insulator, that is, the resistor film itself. It may constitute a thin film.

  The thickness of the resistor film 20 is preferably 10 to 500 μm. When the thickness of the resistor film is 10 μm or more, the durability of the resistor film is good. If the thickness of the resistor film is 500 μm or less, the flexibility of the cable is good.

(the film)
Examples of the material of the film 22 include polyimide, liquid crystal polymer, polyaramid, polyphenylene sulfide, polyamideimide, polyetherimide, polyethylene naphthalate, and polyethylene terephthalate.
The thickness of the film 22 is preferably 3 to 25 μm from the viewpoint of flexibility.
The volume resistance of the film 22 is preferably 1 × 10 ⁶ Ω or more.

(Resistor thin film)
Examples of the material of the resistor thin film 24 include metals, conductive ceramics, and carbon. When the specific resistance of the material is low, the surface resistance can be adjusted to be high by reducing the thickness of the resistor thin film 24. However, since it is difficult to control the thickness, the material of the resistor thin film 24 is relatively A material having a high resistivity is preferred.

Examples of the metal include a ferromagnetic metal and a paramagnetic metal.
Ferromagnetic metals include iron, carbonyl iron, iron alloys (Fe—Ni, Fe—Co, Fe—Cr, Fe—Si, Fe—Al, Fe—Cr—Si, Fe—Cr—Al, Fe—Al—). Si, Fe-Pt, etc.), cobalt, nickel, and alloys thereof.
Examples of the paramagnetic metal include gold, silver, copper, tin, lead, tungsten, silicon, aluminum, titanium, chromium, tantalum, molybdenum, alloys thereof, amorphous alloys, and alloys with ferromagnetic metals.
As the metal, nickel, iron-chromium alloy, tungsten, chromium, and tantalum are preferable from the viewpoint of resistance to oxidation. More preferred is nickel or a nickel alloy.

Conductive ceramics are preferable as a material for the resistor thin film 24 because they are stable without chemical alteration such as oxidation compared to metals.
Examples of the conductive ceramic include an alloy, an intermetallic compound, a solid solution, and the like including a metal and one or more elements selected from the group consisting of boron, carbon, nitrogen, silicon, phosphorus, and sulfur. Specifically, nickel nitride, titanium nitride, tantalum nitride, chromium nitride, titanium carbide, silicon carbide, chromium carbide, vanadium carbide, zirconium carbide, molybdenum carbide, tungsten carbide, chromium boride, molybdenum boride, chromium silicide, Examples thereof include zirconium silicide.
The conductive ceramic can be easily obtained by using a gas containing one or more elements selected from the group consisting of nitrogen, carbon, silicon, boron, phosphorus, and sulfur as a reactive gas in the physical vapor deposition method.

The resistor thin film 24 is formed by, for example, physically depositing the material of the resistor thin film 24 on the surface of the film 22 by physical vapor deposition (EB vapor deposition, ion beam vapor deposition, sputtering, or the like). It is formed by applying a paste containing metal, conductive ceramics, carbon or the like on the surface.
In the resistor thin film, the resistor thin film material is physically vapor-deposited or paste is applied to the surface of the coated wire produced by coextruding the conductor with the first insulator material (resin etc.). May be formed.

When the cross-sectional shape of the conductor 12 is a perfect circle, the resistor thin film 24 has a portion that does not follow the outer periphery of the virtual concentric cylinder V that is coaxial with the conductor 12 as shown in FIGS. It is preferable.
The high-frequency noise current flowing through the conductor 12 flows while causing electromagnetic field fluctuations around the conductor 12. At this time, an electromagnetic field fluctuation, that is, a change in the electromagnetic field vector occurs due to the high frequency noise current, an eddy current is generated in the resistor thin film 24 from the principle of electromagnetic induction, and energy is consumed by the resistance loss due to the resistor thin film 24. In this way, it is considered that high-frequency noise (surge noise) flowing through the conductor 12 is efficiently attenuated. Therefore, in order to easily generate an eddy current in the resistor thin film 24 by electromagnetic induction, the resistor thin film 24 is formed so that a portion not along the outer periphery of the virtual concentric cylinder V coaxial with the conductor 12 is formed. The body thin film 24 is preferably disposed.

  In addition, the resistive thin film 24 is preferably disposed in the vicinity of the conductor 12 because eddy current is likely to be generated in the resistive thin film 24 due to electromagnetic induction. Specifically, the distance D from the surface of the conductor 12 to the portion closest to the conductor 12 in the resistor thin film 24 (hereinafter referred to as the shortest distance D) is preferably 1 to 100 μm, more preferably 10 to 50 μm. preferable. If the shortest distance D is 1 μm or more, the insulation between the conductor 12 and the resistor thin film 24 can be sufficiently maintained. When the shortest distance D is 100 μm or less, a sufficient high frequency noise suppressing effect is exhibited.

  The resistor thin film 24 is normally continuously arranged along the longitudinal direction of the conductor 12. However, as will be described later, the resistor thin film 24 is connected to any conductive material (including an external conductor). Instead, since it is electrically completely floating, it may be intermittently disposed along the longitudinal direction of the conductor 12.

  The surface resistance of the resistor thin film 24 is preferably 1 to 1000Ω, and more preferably 10 to 500Ω. If the surface resistance of the resistor thin film 24 is within this range, a sufficient high frequency noise suppressing effect is exhibited. That is, if the surface resistance of the resistor thin film 24 is too low, it acts as a shield and reflects high frequency noise. If the surface resistance of the resistor thin film 24 is too high, the high frequency noise is not captured by the resistor thin film 24 and is transmitted. Therefore, high frequency noise cannot be suppressed.

  When the resistor thin film 24 is in direct contact with a conductive material such as the conductor 12 or a shield material (metal mesh assembly, aluminum thin film, etc.), the surface resistance is lowered, so that the noise suppressing effect may be lowered. Therefore, it is preferable that the resistor thin film 24 is in an electrically floating state without contacting any conductive material (conductor 12, shield material, external conductor, etc.).

  The width of the resistor thin film 24 in the direction orthogonal to the longitudinal direction of the conductor 12 is preferably 0.5 to 4 times, more preferably 1 to 3 times, the diameter of the conductor 12 per strip of the conductor 12. When the width of the resistor thin film 24 is 0.5 times or more the diameter of the conductor 12, a sufficient high frequency noise suppressing effect is exhibited. If the width of the resistor thin film 24 is not more than 4 times the diameter of the conductor 12, an excess volume is not occupied in the insulating core wire 10, and the flexibility of the cable is not impaired.

  10-500 nm is preferable and, as for the thickness of the resistor thin film 24, 20-100 nm is more preferable. When the thickness of the resistor thin film 24 is 10 nm or more, a sufficient high frequency noise suppressing effect is exhibited. If the thickness of the resistor thin film 24 is 500 nm or less, the surface resistance can be sufficiently increased.

(Inclusions)
When the cross section of the conductor 12 is not a perfect circle, the inclusion 16 is disposed inside the second insulator 14 in order to adjust the shape of the insulating core wire 10 and the resistor film 20, When the cross section of the conductor 12 is a perfect circle, the resistor thin film 24 is disposed inside the second insulator 14 so as to have a portion that does not follow the outer periphery of a virtual concentric cylinder that is coaxial with the conductor 12. It is what is done.

The material of the inclusion 16 is usually a resin or a rubber elastic body. Specific examples of the material of the inclusion 16 include polyethylene, polyvinyl chloride, polyphenylene ether, polyethylene terephthalate, polyamide, fluororesin, thermoplastic elastomer, and silicone resin.
The volume resistance of the inclusions 16 is preferably 1 × 10 ⁶ Ω or more.

(Second insulator)
The material of the second insulator 14 is usually a resin or a rubber elastic body. Specific examples of the material for the second insulator 14 include polyethylene, polyvinyl chloride, polyphenylene ether, polyethylene terephthalate, polyamide, fluororesin, thermoplastic elastomer, and silicone resin.
The volume resistance of the second insulator 14 is preferably 1 × 10 ⁶ Ω or more.

(Cable manufacturing)
The cable can be manufactured, for example, by co-extruding the insulation core wire 10 prepared in advance simultaneously with the extrusion of the material of the sheath 30. At this time, the inclusions filling the gaps between the insulation cores 10 or between the insulation cores 10 and the sheath 30 may be coextruded at the same time, and a shield material is provided between the insulation cores 10 and the sheath 30. You may arrange.

(Function and effect)
Since the cable of the present invention described above has the resistor thin film 24 (resistor) disposed through the film 22 (first insulator) along the longitudinal direction of the conductor 12, high-frequency noise is prevented. It can be suppressed sufficiently.
Further, in the cable of the present invention, the resistor thin film 24 does not need to be contacted (connected) to any conductive material including the external conductor (external terminal), so connection to the external terminal is not complicated.
Moreover, in the cable of this invention, since the cross-sectional area of the resistor thin film 24 which occupies in a cable is small, it is lightweight and has flexibility.
Moreover, in the cable of this invention, since the resistive thin film 24 is arrange | positioned in each insulation core wire 10, the insulation between conductors is fully ensured.

<Cable connection structure>
In the cable connection structure in the present invention, the conductor 12 is connected to the external terminal, and the resistor thin film 24 is not connected to the external conductor including the external terminal. That is, the resistor thin film 24 is made of any conductive material (external conductor). In other words, it is electrically completely floating without being connected.

In such a cable connection structure, since the resistor thin film 24 is not connected to any external conductor, high-frequency noise can be sufficiently suppressed.
Further, in such a cable connection structure, it is not necessary to connect the resistor thin film 24 to the external conductor, so that the connection of the cable to the external terminal is not complicated.
Further, in such a cable connection structure, since the cross-sectional area of the resistor thin film 24 occupying in the cable is small, the cable is light and flexible.

<Motor drive control system>
In the motor drive control system of the present invention, an inverter and a motor whose drive is controlled by the inverter are connected by a cable connection structure using the cable of the present invention.

  FIG. 9 is a schematic diagram showing an example of a motor drive control system provided with the cable of the present invention. The motor drive control system 40 includes an inverter (not shown), a motor 60 whose drive is controlled by the inverter, and the cable 1. One end of the conductor 12 is connected to a terminal 52 of the inverter, and the conductor 12 The other end is connected to the terminal 62 of the motor 60, and the resistor thin film 24 is not connected to any external conductor including the terminal 52 and the terminal 62.

In such a motor drive control system, since the resistor thin film 24 is not connected to any external conductor, surge noise can be sufficiently suppressed in the cable 1. In addition, radiation noise generated from the cable 1 due to surge noise can be suppressed.
Further, in such a motor drive control system, it is not necessary to connect the resistor thin film 24 to the external conductor, so that the connection of the cable 1 to the external terminal is not complicated.
Moreover, in such a motor drive control system, since the cross-sectional area of the resistor thin film 24 occupying in the cable 1 is small, the cable 1 is lightweight and flexible.

  Examples are shown below. The present invention is not limited to these examples.

(Thickness of resistor thin film)
The cross section of the sample was observed using a transmission electron microscope (H9000NAR, manufactured by Hitachi, Ltd.), and the thicknesses of five locations of the resistor thin film were measured and averaged.

(Surface resistance)
Using two thin-film metal electrodes (length: 10 mm, width: 5 mm, distance between electrodes: 10 mm) formed by depositing gold on quartz glass, an object to be measured was placed on the electrodes, and from above the object to be measured, A 10 mm × 20 mm region of the object to be measured was pressed with a load of 50 g, the resistance between the electrodes was measured with a measurement current of 1 mA or less, and this value was defined as the surface resistance.

(High-frequency noise suppression effect)
As shown in FIG. 10, both ends of the conductor of the cable 1 and the terminal of the network analyzer 70 (Anritsu Corporation, 37247D) were connected with a connection cable, and the attenuation characteristic of the high frequency energy of the cable was measured. At this time, the connecting cable was not connected to the resistor thin film of the cable 1.

[Example 1]
Nickel is physically deposited on the entire surface of the polyimide film (length: 1 m, width: 4.5 mm, thickness: 10 μm) under a nitrogen gas flow by a magnetron sputtering method. A resistor thin film 24 (surface resistance: 25Ω) was formed to obtain a resistor film 20.

  A conductor 12 made of copper wire (length: 1 m, diameter: 2 mm) and resistor film 20 are coextruded with the material of the second insulator 14 (polyurethane resin) and the material of inclusions (polyethylene). As a result, an insulation core wire 10 (length: 1 m) as shown in FIG.

Four insulation cores 10 were coextruded with the material of the sheath 30 (polyvinyl chloride) to obtain a cable 1 (length: 1 m) as shown in FIG.
The cable 1 was measured for attenuation characteristics of high frequency energy. The results are shown in FIG. High frequency components of surge noise can be attenuated sufficiently.

  The cable of the present invention is useful as a drive cable (such as a motor drive cable) that connects an inverter and a load (such as a motor).

DESCRIPTION OF SYMBOLS 1 Cable 2 Cable 3 Cable 4 Cable 5 Cable 6 Cable 10 Insulation core wire 12 Conductor 14 2nd insulator 16 Inclusion 18 Wire 20 Resistor film 22 Film (1st insulator)
24 Resistor thin film (resistor)
30 sheath 40 motor drive control system 52 terminal 60 motor 62 terminal 70 network analyzer

Claims (8)

A cable having a plurality of insulated core wires and a sheath covering them,
The insulating core includes a conductor, a first insulator, a resistor disposed through the first insulator along a longitudinal direction of the conductor, and a second insulator covering the conductor. Have a cable.   The cable according to claim 1, wherein a cross section of the conductor is not a perfect circle. A cross section of the conductor is a perfect circle;
The cable according to claim 1, wherein the resistor has a portion that does not follow an outer periphery of a virtual concentric cylinder that is coaxial with the conductor. The first insulator is a film;
The cable according to claim 1, wherein the resistor is a resistor thin film formed on a surface of the film.   The cable according to any one of claims 1 to 4, wherein a distance from the conductor to a portion of the resistor closest to the conductor is 1 to 100 µm.   The cable according to claim 1, wherein the resistor has a surface resistance of 1 to 1000Ω.   The cable according to any one of claims 1 to 6, wherein a width of the resistor is 0.5 to 4 times a diameter of the conductor.   The cable according to claim 1, wherein the resistor has a thickness of 5 to 100 nm.

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