JP2005063765A - Electric wire for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric wire for an automobile using carbon fibers having a specific gravity smaller than that of metal such as copper, having smaller electric resistance while taking advantage of lightness. <P>SOLUTION: The electric wire for an automobile is composed of a conductor made of metal wires, a conductor made of carbon fibers, and an insulation body covering those conductors. Especially, the conductor made of the metal wires is arranged inside the conductor made of the carbon fiber, and an outer periphery of the conductor made of the carbon fiber is covered by the insulation body. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an automobile electric wire. More specifically, the present invention relates to an automobile electric wire that has a conductor made of carbon fiber, is light in weight, and has a high electrical conductivity and is suitable for automobile wiring.

  Conventionally, as an electric wire for automobiles used for the supply of electricity to electrical components in automobiles, communication, sensing, etc., a conductor made of a metal such as copper is often coated with an insulator (for example, Non-Patent Document 1).

  However, such a conventional automobile electric wire is heavy because a metal having a large specific gravity such as copper is mainly used as a conductor. Moreover, in recent years, various information-related sensors have increased, and the number of electric wires for supplying electricity to sensors and related parts has increased, so the influence of the weight of the wires on the weight of the entire vehicle has also increased. ing. When the weight of the entire vehicle increases, the fuel consumption and the like also decrease, which is not preferable from the viewpoint of environmental problems. Therefore, there has been a demand for lighter automotive electric wires that can replace conventional copper wires.

  Therefore, as a result of repeated studies, the present inventors have provided a conductor made of carbon fiber and an insulator covering the outer periphery of the conductor as a lighter automotive electric wire that replaces the conventional copper wire. The characteristic electric wire for automobiles was invented and a patent application was filed as Japanese Patent Application No. 2002-306310.

The present invention is characterized in that a carbon fiber having a specific gravity smaller than that of a metal such as copper is used as a conductor. Accordingly, since it is lighter than conventional electric wires for automobiles, the use of this electric wire makes it possible to reduce the weight of the vehicle and improve the fuel efficiency.
Hitachi Cable, Ltd. website, “Transport aircraft wires, automotive wires, ultra-thin low-voltage wires for automobiles” [online], [October 21, 2002 search], Internet <http: // www. Hitachi-cable. co. jp / insulated / 05. pdf>

  However, since carbon fiber has a larger electric resistance than metals such as copper, an electric wire characterized by using carbon fiber has a large electric resistance. For example, an electric wire obtained by bundling 3000 PAN-based carbon fibers, which are fine filaments having a diameter of about 7 μm, has an electric resistance of 150 Ω / m.

  An electric wire having such a large resistance is used on the input side of the switch element or the like, but in many other applications as an electric wire for an automobile, an electric wire having no resistance is preferable. Therefore, the electric wire characterized by using the above carbon fiber has a narrow range of use as an automobile electric wire. Therefore, there has been a demand for an automobile electric wire with lower electric resistance while maintaining the advantages of a light-weight carbon fiber electric wire.

  An object of the present invention is to provide an automobile electric wire with lower electrical resistance while maintaining the advantages of an electric wire using carbon fiber such as lightweight. The present inventor has found that this object can be achieved by using a conductor made of a metal wire together with a conductor made of carbon fiber, and has completed the present invention.

  That is, this invention provides the electric wire for motor vehicles characterized by having the conductor which consists of metal wires, the conductor which consists of carbon fibers, and the insulator which coat | covers these conductors.

Hereinafter, the present invention will be described in more detail.
Examples of the metal constituting the conductor made of the metal wire include metals having high conductivity, such as copper, silver, and aluminum. Usually, inexpensive copper is used.

  The number of metal wires with respect to the conducting wire made of one carbon fiber may be one or plural. In the case of a plurality of wires, they may be bundled by a method such as twisting them, or each may be separated and provided in a conductor made of carbon fiber or in an insulator.

  As the shape of the metal wire, a linear one that is continuous over the entire length of the electric wire is usually used. However, when a conductor made of a metal wire is provided in a conductor made of carbon fiber, a short fiber-like metal wire A material in which (for example, a filament) is dispersed in a conductor made of carbon fiber can be used, and such a form is also included in the conductor made of the metal wire of the present invention.

A metal wire has the thickness which can ensure the electrical conductivity calculated | required by an electric wire. Since the electrical conductivity is also affected by the material, number, shape, etc. of the metal wire, the preferred thickness of the metal wire varies depending on the material, number, shape, etc. of the metal wire.
As long as the required conductivity can be ensured, in order to reduce the weight of the electric wire, the number of metal wires is small and the thickness is preferably thin.

  A conductor made of carbon fibers is preferably used by concentrating a plurality of carbon fibers in order to improve the flexibility. The number and the thickness of the conductor are appropriately adjusted according to the material so that the required mechanical strength can be obtained. In the electric wire for automobiles of the present invention, conductivity is obtained not only by a metal wire but also by carbon fiber. Therefore, if a certain degree of conductivity is obtained by the carbon fiber, the number of metal wires can be reduced and the thickness can be reduced. Thus, in adjusting the number of carbon fibers and the thickness and number of conductors made of carbon fibers, conductivity is taken into consideration.

  Examples of the carbon fiber constituting the conductor made of carbon fiber include pitch-based carbon fiber made from petroleum or coal pitch and PAN-based carbon fiber made from polyacrylonitrile, and any of them may be used in the present invention. A commercially available filament may be used. In general, pitch-based carbon fibers tend to have good conductivity but lower strength (particularly tensile strength) than PAN-based carbon fibers. Therefore, when considering strength, PAN-based carbon fibers are preferable.

  Examples of the carbon fiber bundling method include vertical attachment. However, as a filament made of carbon fiber, when a generally known diameter of about φ10 μm or less, particularly about 6 to 7 μm, is added in a plurality of lengths to make a circular cross section, for example, the filament slips in the radial direction. , Easy to flatten. Therefore, vertical attachment is preferable when the cross section of a conductor such as a flat cable is elliptical or flat.

  On the other hand, when a conductor made of carbon fibers is desired to have a circular cross section, it is preferable to twist a plurality of carbon fibers. By twisting together, it is easy not only to keep the cross section in a circular shape, but also to make the cross section of the conductor close to a perfect circle, the cross section can be made smaller and the storage capacity in the vehicle can be reduced. The twist may be S twist or Z twist, or SZ twist in which S twist and Z twist are alternately performed. Since the SZ twist can be manufactured by alternately rotating the twisting dies, the manufacturing equipment can be simplified and the productivity is excellent.

  As an insulator covering a conductor made of a metal wire and a conductor made of carbon fiber, the same conductor as that used as an insulator in a general electric wire made of a metal such as copper can be used. Examples thereof include resins having insulating properties, and specific examples include polyethylene such as low density polyethylene and high density polyethylene, ethylene vinyl acetate copolymer (EVA resin), polyvinyl chloride (PVC), and the like.

The insulation is coated by extruding resin with an extruder. For example, a conductor made of a metal wire and a conductor made of carbon fiber, or a conductor made of carbon fiber containing a conductor made of metal wire is inserted into a die through a guide hole of the nipple and supplied from a resin hole formed by the nipple and the die. And a method of extruding the resin while covering the conductor with the formed resin.
In order to reduce the problem that the carbon fiber is cut by the force from the resin at the nipple-die portion, one in which one end of the nipple protrudes from the die hole may be used.

  As a more specific aspect of the present invention, a conductor made of a metal wire is provided in a conductor made of carbon fiber, and the outer periphery of the conductor made of carbon fiber is covered with an insulator. An electric wire for automobiles to be used. The electric wire configured as described above is preferable as an automobile electric wire using a large power while being lightweight.

  As another more specific aspect of the present invention, the outer periphery of a conductor made of a metal wire is covered with an insulator, and a conductor made of carbon fiber is provided inside the insulator. In addition, a conductor made of a metal wire is provided in a conductor made of carbon fiber, and an outer periphery of the conductor made of carbon fiber is covered with an insulator. In addition, an automobile electric wire characterized in that a conductor made of carbon fiber is further provided.

  Such electric wires for automobiles can be used for large currents by passing the same current through a conductor made of metal wire and a conductor made of carbon fiber. In addition, as will be described later, a different current is passed for each different conductor. It can be used for many purposes at the same time.

  As described above, automobile wires are used in various applications such as supplying electricity to electrical components, communication, and sensing, and the required conductivity differs depending on the application. For example, when it is used for supplying electricity to an electrical component, a relatively large conductivity is required, but when it is used for a weak electric signal such as communication and sensing, a large conductivity is not required.

  Moreover, if such electric wires for various applications can be accommodated in one electric wire, the number of electric wires for automobiles, that is, the weight can be reduced, and as a result, reduction of vehicle weight, reduction of fuel consumption, etc. are achieved. be able to.

  An electric wire for an automobile, wherein a conductor made of a metal wire is covered with an insulator, and a conductor made of carbon fiber is provided inside the insulator, and a conductor made of a metal wire is carbon fiber An automobile characterized in that the outer periphery of the conductor made of carbon fiber is covered with an insulator, and the conductor made of carbon fiber is further provided inside the insulator. The electric wire achieves the purpose of accommodating electric wires for various uses in one electric wire.

  That is, a conductor made of a metal wire or a conductor made of carbon fiber in which a conductor made of a metal wire is provided has a relatively large electric conductivity. A conductor made of carbon fiber provided in an insulator is used for applications where high conductivity is not required, such as for weak electric signals.

  The number of conductors made of metal wires and the number of conductors made of carbon fibers in which the conductors made of metal wires are provided in one electric wire are not particularly limited, and may be one or more. Similarly, the number of conductors made of carbon fibers provided in the insulator is not limited. The conductor made of carbon fiber provided inside the insulator is not normally used for a large current application, and therefore may be relatively thin. As a result, a large number of conductors can be accommodated in one electric wire. Often possible. By storing a large number of wires in one electric wire, the number of electric wires for automobiles can be reduced, and as a result, reduction in vehicle weight, reduction in fuel consumption, and the like can be achieved.

  The electric wire for automobiles of the present invention having a conductor made of metal wire, a conductor made of carbon fiber, and an insulator covering these conductors has low electric resistance while maintaining the advantages of a wire using carbon fiber such as light weight. It is preferably used for applications that require high conductivity, such as supplying electricity to electrical components.

  In particular, when the outer periphery of a conductor made of a metal wire is covered with an insulator and a conductor made of carbon fiber is provided inside the insulator, a large electrical conductivity such as supply of electricity to electrical components is required. Can be handled with a single electric wire, and the number of electric wires for automobiles can be reduced, resulting in the weight of the vehicle. Can be further reduced, and fuel consumption can be reduced.

Hereinafter, although the more concrete form of implementation of this invention is demonstrated using drawing, the scope of the present invention is not limited by this form.
FIG. 1 is a cross-sectional view of an automobile electric wire perpendicular to the length direction of the electric wire, showing an example of the present invention. In this example, one copper wire is provided as a conductor 1 made of a metal wire in a conductor 2 made of carbon fiber. The outer periphery of the conductor 2 made of carbon fiber is covered with an insulator 3.

The cross-sectional shape of the electric wire in this example is circular, and as the conductor 2 made of carbon fiber, a plurality of carbon fibers that are bundled by SZ twisting are used.
Further, as in this example, it is preferable that the conductor 1 made of a metal wire is positioned at the center of the conductor 2 made of carbon fiber in order to allow a current to flow in a balanced manner with respect to the cross section of the wire. It is not limited to such a structure.

  FIG. 3 is a cross-sectional view perpendicular to the length direction of the electric wire, showing an example of the terminal end of the automobile electric wire in the example of FIG. As shown in FIG. 3, the end of the conductor 2 made of carbon fiber having the conductor 1 made of a metal wire at the center is inserted into the connector pin 7 and wired to the electrical component through the connector pin 7. The connection between the connector pin 7 and the end of the conductor 2 made of carbon fiber is performed using the reaction force of the conductor 2 made of carbon fiber and the conductor 1 made of metal wire.

  FIG. 2 is a cross-sectional view of an automobile electric wire perpendicular to the length direction of the electric wire, showing another example of the present invention. In this example, a conductor 4 made of a metal wire is provided at the center of the electric wire, and the outer periphery thereof is covered with an insulator 6. Five conductors 5 made of carbon fiber are provided inside the insulator 6. The cross-sectional shape of the electric wire in this example is circular, and the cross-sectional shape of the conductor 5 made of carbon fiber is also circular, and the conductor 5 made of carbon fiber is obtained by concentrating a plurality of carbon fibers by SZ twisting. It is used.

  In the electric wire of this example, the conductor 4 made of a metal wire is used for power supply and the like, while the conductor 5 made of carbon fiber is used for transmission for a weak electric signal. From the viewpoint of reliability, the same signal can be supplied to the conductor 5 made of five carbon fibers, or different signals can be supplied to meet various purposes. In addition, as long as desired electrical conductivity is obtained, it is also possible to use the conductor consisting of carbon fiber which has the conductor consisting of a metal wire inside instead of the conductor 4 consisting of a metal wire.

  In the example of FIG. 1, only one conductor 2 made of carbon fiber is provided inside the insulator 3. In the example of FIG. 2, the conductor 4 made of metal wire is placed inside the insulator 6. Is provided, but a plurality of conductors made of carbon fiber or metal wires may be provided inside the insulator. For example, a plurality of conductors made of carbon fiber or metal wires may be arranged in parallel in an insulator having a flat cross section.

It is sectional drawing of the electric wire for motor vehicles of the orthogonal | vertical direction with respect to the length direction of an electric wire which shows an example of this invention. It is sectional drawing of the electric wire for motor vehicles of the orthogonal | vertical direction with respect to the length direction of an electric wire which shows the other example of this invention. It is sectional drawing of a perpendicular | vertical direction with respect to the length direction of an electric wire which shows an example of the terminal of the electric wire for motor vehicles of the example of FIG.

Explanation of symbols

1, 4 Conductor made of metal wire 2, 5 Conductor made of carbon fiber 3, 6 Insulator 7 Connector pin

Claims (2)

An automobile electric wire comprising a conductor made of a metal wire, a conductor made of carbon fiber, and an insulator covering these conductors. The electric wire for automobiles according to claim 1, wherein a conductor made of a metal wire is provided in a conductor made of carbon fiber, and an outer periphery of the conductor made of carbon fiber is covered with an insulator.

Images