JP2016110936A - Wire harness for transistor input/output circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire harness for transistor input/output circuit which has an excellent noise reduction effect against digital signals, which has a smaller sectional shape, which has a reduced weight per a unit length, and which may realize downsizing in an electronic unit.SOLUTION: The wire harness comprises: covered electrical line 2 in which a conductor 2a transmitting digital signals is covered with conductor covering material 2b; an inner metal thin membrane 3 formed to cover peripheral part of the covered electrical line 2; middle synthetic resin coat 4 formed to cover peripheral part of the inner metal thin membrane 3; an outer metal thin membrane 5 formed to cover peripheral part of the middle synthetic resin coat 4: and a cable covering material 6 covering the outer metal thin membrane 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wire harness for a transistor input / output circuit.

  Conventionally, a wire harness is known in which a plurality of shielded covered electric wires are bundled and one of them is used as a grounding electric wire to reduce signal noise (see, for example, Patent Document 1).

  As shown in FIG. 2 and FIG. 3, the wire harness 51 described in Patent Document 1 is an aluminum foil polyester laminate in which a conductor 52a is covered with a covering material 52b and an aluminum foil 53a is laminated with a polyester tape 53b. It has a configuration in which a plurality of shielded covered electric wires 54 covered with the tape 53 so that the aluminum foil 53a is exposed, the shielded covered electric wires 54 are bundled, and an adhesive tape 55 is wound around and fixed to each other. doing.

  In the wire harness 51, one aluminum foil 53a in the shielded covered electric wire 54 described above is electrically connected to a ground circuit (not shown) so as to function as a grounding electric wire 54A, and other plural shielded covered wires are provided. The conductor 52a of the electric wire 54 is connected to a device (not shown) to function as the signal electric wire 54B.

  In the wire harness 51, the shielded covered electric wire 54 is bundled, whereby the aluminum foil 53a of the signal wire 54B is electrically connected to the aluminum foil 53a of the ground wire 54A, and the conductor 52a of the signal wire 54B is connected to the conductor 52a. It exhibits an electrostatic shielding effect.

  When the wire harness 51 described above is used in a transistor input / output circuit that connects a microcomputer and an electronic unit, the electrostatic shielding effect of the aluminum foil 53a causes a ripple that is superimposed on a digital signal and causes noise. The voltage cannot be removed.

  For this reason, for example, a noise filter (not shown) such as a coil or a ferrite is attached to an intermediate portion of the wire harness 51 to remove the above-described ripple voltage and reduce the noise of the digital signal.

  Alternatively, it is necessary to reduce the noise of the digital signal by installing a plurality of noise removing capacitors on the substrate of the electronic unit to which the wire harness 51 is connected and storing the ripple voltage described above as electric charges.

Japanese Patent Laid-Open No. 06-124608

  However, since the above-described wire harness 51 has one of the shielded covered electric wires 54 functioning as the grounding electric wire 54A, there is a problem that the cross-sectional shape becomes large and the weight per unit length becomes heavy. It was.

  Further, when a noise filter is attached to the middle part of the wire harness 51 for the transistor input / output circuit, there is a problem that the sectional shape becomes larger and the weight per unit length becomes heavier.

  When a plurality of noise removing capacitors are installed on the substrate of the electronic unit to which the wire harness 51 is connected, there is a problem that the electronic unit becomes large.

  The present invention has been made in order to solve the above-described problems, has a high noise reduction effect on digital signals, can reduce the cross-sectional shape, and can reduce the weight per unit length. An object of the present invention is to provide a wire harness for a transistor input / output circuit capable of downsizing an electronic unit.

  In order to achieve the above object, a wire harness for a transistor input / output circuit according to the present invention includes a covered electric wire in which a conductor carrying a digital signal is covered with a conductor covering material, and an inner metal formed so as to cover the outer periphery of the covered electric wire. A thin film, an intermediate synthetic resin film formed so as to cover the outer peripheral part of the inner metal thin film, an outer metal thin film formed so as to cover the outer peripheral part of the intermediate synthetic resin film, and the outer metal thin film are covered And a cable covering material.

  The wire harness for a transistor input / output circuit according to the present invention has a configuration in which the inner metal thin film and the outer metal thin film are electrically insulated by the intermediate synthetic resin film and formed coaxially on the covered electric wire. When the transistor input / output circuit connecting the microcomputer and the electronic unit is used, the inner metal thin film is connected as a plus applied voltage circuit between the microcomputer and the electronic unit, and the outer metal thin film is connected to the microcomputer. When a negative applied voltage circuit is connected between the electronic unit and the electronic unit, the intermediate synthetic resin film, which is a dielectric, and the inner metal thin film and the outer metal thin film separated by the intermediate synthetic resin film function as a capacitor.

  For this reason, in the transistor input / output circuit wire harness according to the present invention, the ripple voltage that causes noise superimposed on the digital signal carried by the conductor can be stored as an electric charge in the intermediate synthetic resin film, Noise of the digital signal can be reduced.

  The wire harness for a transistor input / output circuit according to the present invention has an inner metal thin film formed on the outer peripheral portion of the covered electric wire, an intermediate synthetic resin coating formed on the outer peripheral portion of the inner metal thin film, and an outer peripheral portion of the intermediate synthetic resin coating. Since the outer metal thin film is formed on the wire harness, the cross-sectional shape is smaller than the conventional wire harness that allows one of the plurality of shielded covered wires to function as a grounding wire. Weight can be reduced.

  In the wire harness for a transistor input / output circuit according to the present invention, the inner metal thin film, the intermediate synthetic resin film, and the outer metal thin film function as a capacitor, so that the noise filter conventionally attached to the intermediate part of the wire harness is eliminated. In addition, the number of noise removing capacitors and the electrostatic capacity installed on the substrate of the electronic unit can be reduced, and the electronic unit can be downsized.

  According to the present invention, a transistor input / output that has a high noise reduction effect on a digital signal, can reduce the cross-sectional shape, can reduce the weight per unit length, and can downsize an electronic unit. A circuit wiring harness can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the manufacturing process of the wire harness for transistor input / output circuits which concerns on embodiment of this invention, (a) shows the state which formed the inner side metal thin film in the outer peripheral part of a covered electric wire, (b) is inner side (C) shows a state in which an intermediate synthetic resin film is formed on the outer peripheral part of the metal thin film. The completed state of the output circuit wire harness is shown. It is a longitudinal section of the conventional wire harness. It is AA sectional drawing of FIG.

  Hereinafter, a wire harness for a transistor input / output circuit according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a transistor input / output circuit wire harness 1 according to an embodiment of the present invention includes a covered electric wire 2 in which a conductor 2a carrying a digital signal is covered with a conductor covering material 2b, and an outer periphery of the covered electric wire 2. The inner metal thin film 3 formed so as to cover the inner part, the intermediate synthetic resin film 4 formed so as to cover the outer peripheral part of the inner metal thin film 3, and the outer formed so as to cover the outer peripheral part of the intermediate synthetic resin film 4 A metal thin film 5 and a cable covering material 6 that covers the outer metal thin film 5 are provided. The inner metal thin film 3, the intermediate synthetic resin film 4, the outer metal thin film 5, and the cable covering material 6 are formed coaxially on the covered electric wire 2.

  The conductor 2a constituting the covered electric wire 2 is formed of a metal having excellent conductivity such as aluminum or copper, for example. Moreover, the conductor coating | covering material 2b which comprises the covered electric wire 2 is formed with the synthetic resin excellent in electrical insulation, such as polyvinyl chloride and polyethylene.

  The inner metal thin film 3 is made of, for example, a metal having excellent conductivity such as aluminum or copper, and is formed on the outer periphery of the conductor coating material 2b by a known method such as a sputtering method or a high-frequency ion plating method. 2 is surrounded in the circumferential direction.

  The intermediate synthetic resin coating 4 is made of a synthetic resin such as polyethylene having excellent electrical insulation and large capacitance, and is formed so as to be in close contact with the outer peripheral portion of the inner metal thin film 3 in a thin film shape. 3 is surrounded in the circumferential direction.

  The outer metal thin film 5 is made of, for example, a metal having excellent conductivity such as aluminum or copper, and is formed on the outer peripheral portion of the intermediate synthetic resin coating 4 by a known method such as a sputtering method or a high-frequency ion plating method, The intermediate synthetic resin coating 4 is surrounded in the circumferential direction.

  The cable covering material 6 is formed of a synthetic resin excellent in electrical insulation, such as polyvinyl chloride or polyethylene, and surrounds the outer metal thin film 5 in the circumferential direction.

  The wire harness 1 for transistor input / output circuit according to the present embodiment is coaxial with the covered electric wire 2 in a state where the inner metal thin film 3 and the outer metal thin film 5 are electrically insulated by the intermediate synthetic resin coating 4. Since it is formed, when used in a transistor input / output circuit connecting a microcomputer and an electronic unit, the inner metal thin film 3 is connected as a plus applied voltage circuit between the microcomputer and the electronic unit. At the same time, when the outer metal thin film 5 is connected as a negative applied voltage circuit between the microcomputer and the electronic unit, the intermediate synthetic resin film 4 and the inner metal thin film 3 separated by the intermediate synthetic resin film 4 are dielectrics. The outer metal thin film 5 functions as a capacitor.

  For this reason, in the transistor input / output circuit wire harness 1 according to the present embodiment, the ripple voltage that causes noise superimposed on the digital signal conveyed by the conductor 2a is applied to the intermediate synthetic resin coating 4 as a charge. It can be stored and noise of the digital signal can be reduced.

  In the wire harness 1 for transistor input / output circuit according to the present embodiment, an inner metal thin film 3 is formed on the outer peripheral portion of the covered electric wire 2, and an intermediate synthetic resin coating 4 is formed on the outer peripheral portion of the inner metal thin film 3. Since the outer metal thin film 5 is formed on the outer peripheral portion of the synthetic resin coating 4, the cross-sectional shape is larger than that of a conventional wire harness in which one of the plurality of shielded covered wires functions as a grounding wire. Can be reduced and the weight per unit length can be reduced.

  In the transistor input / output circuit wire harness 1 according to the present embodiment, the inner metal thin film 3, the intermediate synthetic resin film 4 and the outer metal thin film 5 function as a capacitor, and thus are conventionally attached to the intermediate part of the wire harness. The noise filter can be eliminated, and the electronic unit can be downsized by reducing the number and capacitance of noise removing capacitors installed on the substrate of the electronic unit.

  As described above, the transistor input / output circuit wire harness according to the present invention has a high noise reduction effect on digital signals, can reduce the cross-sectional shape, and can reduce the weight per unit length. Therefore, it is possible to provide a wire harness for a transistor input / output circuit that can reduce the size of the electronic unit, and is useful for all wire harnesses for a transistor input / output circuit.

DESCRIPTION OF SYMBOLS 1 Wire harness for transistor input / output circuits 2 Covered electric wire 2a Conductor 2b Conductor coating material 3 Inner metal thin film 4 Middle synthetic resin film 5 Outer metal thin film 6 Cable coating material

Claims (1)

A covered electric wire in which a conductor carrying a digital signal is covered with a conductor covering material;
An inner metal thin film formed so as to cover the outer periphery of the covered electric wire;
An intermediate synthetic resin film formed so as to cover the outer periphery of the inner metal thin film;
An outer metal thin film formed to cover the outer periphery of the intermediate synthetic resin coating;
A wire harness for a transistor input / output circuit, comprising: a cable covering material that covers the outer metal thin film.

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