JP2002140938A - Shielded wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shielded wire applied, for example, to a wire harness used in an electronic apparatus or an automobile, forming a continuous, even and uniform shielding surface without producing spaces in overlapping parts among shielding tapes, increasing electrical affinity by stably and tightly fitting a drain wire to a conductive surface, thereby exerting an excellent shield function in a high frequency range. SOLUTION: In this shielded wire, the shielding tapes 4 having the conductive surfaces are wound around wires 1. The drain wire 6 is arranged on the circumference of the wires 1 throughout the axial length direction X and bundled along with the wires, and the shielding tapes 4 with the conductive surfaces 5a and 5b formed on the inside and outside surfaces are wound around the wires and the drain wire up to positions nearly coincident with the termination parts of the wires.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shielded electric wire, and is applied to, for example, a wire harness used for an electronic device, a copying machine, a facsimile, an automobile, etc., and is used particularly as a wire having an excellent shielding function.

[0002]

2. Description of the Related Art Conventionally, a wire harness has been used as a wiring for connecting an electric system portion of an automobile. However, in order to suppress the influence of noise generated inside the automobile, this wire harness is used. , Shielded wires are used. Also, for the production of wire harness,
Automatic production methods using automatic machines have been adopted from the viewpoint of responding to high-mix low-volume production, saving labor, and improving quality. Pre-processing was necessary in which the terminal must be punched to attach the terminal to the conductor later. Since the electric wires were then bundled, it did not reach the point of fully automatic production. Conventionally, shielded wires include those shown in FIGS. That is, a shield tape d obtained by laminating a metal foil c such as aluminum or copper as a conductive surface on the lower surface of an insulator b of, for example, PET (polyethylene terephthalate) resin is provided on the outer periphery of the wire bundle obtained by bundling a plurality of wires a. Some were wound. The drain wire e is formed so as to be in contact with the conductive surface in the axial direction X ′ of the wire bundle. f is at the end of the electric wire a,
A terminal crimped after peeling the covering portion, and f 'is a terminal crimped to a terminal portion of the drain wire e.

[0003]

However, as shown in FIGS. 4 and 5, the conventional shielded wire in which the shield tape d is wound around the outer periphery of the wire bundle in which a plurality of wires a are bundled has a sufficient shield. Could not function. When such a shielded wire is used as a wire harness for an automobile or the like, since electronic components for mounting on a vehicle are increasing in recent years, a device malfunctions due to noise generated from these electronic components or external noise, Failure will occur. In particular, good conductivity cannot be ensured in a high frequency range. That is, conductivity is exhibited only in the winding direction of the shield tape d with respect to the electric wire a, which acts as an inductance in a high-frequency range, and may have an adverse effect. For this reason, the terminal portion of the electric wire a required for crimping the terminal f to the electric wire a becomes a non-shielded portion, and it is necessary to provide a shield at this portion. Further, since the conductive surface of the shield tape d is formed by laminating a metal foil c of aluminum, copper or the like on one of the upper surface and the lower surface with respect to the insulator b as a support base made of PET, The shrinkage was poor, and the wire a was not wound at an average elongation or shrinkage. And electric wire a
It is also considered that a gap is easily generated in the overlapped portion g of the shield tape d wound and the magnetic flux leaks, which is a cause that the sufficient shielding function cannot be performed. In addition, the adhesiveness of the drain wire e with the shield tape d is also unstable, and the non-contact state is exhibited, so that it does not work as a good electromagnetic field shield surface.

[0004] The present invention solves the above-mentioned disadvantages of the prior art, and forms a continuous, uniform and identical shield surface even at the end of an electric wire, and stably adheres a drain wire to a conductive surface to provide an electrical affinity. An object of the present invention is to provide a shielded electric wire which is excellent in conductivity even in a high-frequency range due to an increase in performance, and which exhibits a sufficient shielding function without generating a gap between overlapping portions of the shield tape.

[0005]

According to the first aspect of the present invention, there is provided a shielded electric wire wound around a shield tape having a conductive surface on the outer periphery of the electric wire, and a drain is provided around the outer periphery of the electric wire in the axial direction. Route the wires and focus together with the wires,
Means is adopted in which a shield tape having conductive surfaces formed on the inner surface and the outer surface on the outer periphery of the electric wire and the drain wire is wound up to a position substantially corresponding to a terminal portion of the electric wire.

According to a second aspect of the present invention, an insulating tape is wound around the outer circumference of the shield tape wound around the outer circumference of the electric wire as required, or a sleeve,
A means of coating with an exterior protective body made of a resin mold or the like is employed.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of the present invention. Reference numeral 1 denotes an electric wire. As the electric wire 1, a core electric wire in which an outer periphery of a conductor portion 2 is covered with a covering portion 3 is used in the drawing. In this embodiment, FIGS.
As shown in FIG. 2, a plurality of electric wires 1 are used as a bundle of bundled electric wires. The point that the shield tape 4 having a conductive surface is wound around the outer periphery of the wire bundle is the same as the conventional shielded wire shown in FIGS. 4 and 5.

However, in this embodiment, the electric wires 1, 1
Measures the length of each wire 1 before focusing, strips the insulator at the end of wires 1, 1,... From the conductor 2, and applies the terminal T to the stripped conductor 2. After the tightening, the drain wires 6 are routed around the outer circumferences of the electric wires 1, 1... In the axial direction X as shown in FIG. 1 to be bundled together with the electric wires 1, 1. The shield tape 4 can also be wound up.

The shield tape 4 used in this embodiment is made of, for example, PET (polyethylene terephthalate).
A material in which conductive surfaces 5a and 5b made of metal foil such as aluminum or copper are formed on the lower and upper surfaces of an insulator 4a made of resin is used. And this shield tape 4
Are spirally wound around the outer circumference of the electric wires 1, 1.
The conductive surfaces 5a and 5b formed on the lower surface and the upper surface of
The spirally overlapped portion is wound so as to oppose and closely contact with each other, so that the shielding function becomes dense. At this time, the wires 1, 1...
Until the end of the shield tape 4 substantially matches the end of the wire 1,
1 and the drain wire 6 are completely wound until the non-winding area is minimized. The shield tape 4 has conductive surfaces 5a and 5b formed on the upper and lower surfaces of an insulator 4a. Since it is a tape, the inner conductive surface 5a
Is tightly contacted with the drain line 6 at every corner, and the conductive surface 5a on the inner surface side and the conductive surface 5b on the outer surface side of the shield tape 4 are in close contact with each other at the overlapping portion of the shield tape 4, thereby forming a gap. It can be wound so that there is no leakage magnetic flux. And this shield tape 4
The winding direction of the spiral may be wound in either a clockwise direction or a counterclockwise direction, and is not limited to the winding direction, and is not limited to a single layer and may be wound in a plurality of layers. The number of windings is not limited.

Although not shown in the figure, an insulating tape is wound around the outer periphery of the shield tape 4 wound around the outer periphery of the electric wires 1, 1. By being covered with an exterior protective body,
The shielded electric wire is protected, watertightness can be ensured, and intrusion of dust and the like can be prevented.

The drain wire 6 is routed around the outer circumference of the electric wires 1, 1... In the axial direction X, and is bundled with the electric wires 1, 1,. By contacting with, the electrical affinity can be increased as compared with the related art, and the shielding function can be enhanced.

One embodiment of the present invention has the above-mentioned configuration,
When the drain wire 6 is routed around the outer circumference in the axial direction X and the shield tape 4 is wound around the outer circumference of the bundled electric wires 1, 1,..., The shield tape 4 is made of aluminum or copper on the upper and lower surfaces of the insulator 4a. Conductive surface 5 made of metal foil such as
Since a double-sided conductive member formed with a and 5b is used, the spiral overlapping portions of the shield tape 4 are
Since the conductive surfaces 5a and 5b face each other and are in close contact with each other, no gap is opened and the amount of leakage magnetic flux can be reduced. Moreover,
Until the terminals T, T 'are substantially coincident with the ends of the wires 1, 1... And the drain wire 6 to be crimped, the non-winding area is minimized with respect to the wires 1, 1,. When it is completely wound, the shield tape 4
Is a double-sided conductive tape in which conductive surfaces 5a and 5b are formed on the upper and lower surfaces of the insulator 4a, so that the conductive surface 5a disposed on the inner surface side is in close contact with the drain line 6 to every corner. In addition, since the conductive surface 5a on the inner surface side and the conductive surface 5b on the outer surface side of the shield tape 4 are in close contact with each other in the overlapping portion of the shield tape 4, the leakage magnetic flux can be eliminated without a gap. In this way, a relatively uniform and identical electromagnetic field shielding surface is formed by the conductive surfaces 5a and 5b on both surfaces, and a sufficient and reliable shielding function can be exhibited.

The winding of the shield tape 4 can be performed even when the bundled electric wires 1 are branched.
.., And even the terminal portion can be easily wound so that the conductive surfaces 5a and 5b can exert a sufficient and reliable shielding function.

Further, the shielded electric wire of the present embodiment is the electric wire 1
Is measured by a single wire and cut, and thereafter, the covering portion 3 is peeled, the terminals are caulked to the conductor portion 2 and then bundled, and then the shield tape 4 is automatically wound by an automatic tape winding machine. It can be applied to automatic machine production when manufacturing wire harnesses, improving productivity,
Quality and cost can be improved. Alternatively, the shield tape 4 can be manually wound around the outer periphery of the wire bundle.

In the drawing, the shield tape 4 is
1 shows a state in which one winding is wound around the outer circumference, but if the number of windings is increased by winding the shield tape 4 several times, both surfaces formed on the outer surface and the inner surface of the shield tape 4 will be described. The conductive surfaces 5a and 5b face each other and the thickness of the shield layer increases, so that the electromagnetic field shielding function is more reliably exhibited. This is because the electromagnetic field shielding function may be, for example, reflected on the surface of the shield member 10 and absorbed inside as shown in FIG.
It is determined by the magnetic permeability μ and the thickness t of the shield member 10, and when the shield tape 4 is wound as the shield member 10, the number of reflections at the boundary surface with respect to the shield layers S, S is increased as compared with the case of a single layer. Since the transmittance (leakage amount) is reduced and the total thickness is increased to 2 × t by the two shield layers S, S, the absorption of electromagnetic waves inside the shield layers S, S is increased to attenuate. As a result, the electromagnetic field shielding function can be reliably exhibited.

Also, as described above, the drain wire 6 is connected to the conductive surface 5a formed on the inner surface of the shield tape 4 wound around the outer circumference of the electric wires 1, 1. So that the drain line 6
And the conductive surface 5a surely adhere to each other to increase the stability, thereby increasing the electric affinity.

In addition, since the conductive surface 5a and the drain wire 6 routed in the axial direction X of the electric wires 1, 1... Since the shielded electromagnetic field is formed, good conductivity can be ensured especially in a high frequency range, and no adverse effect is caused by acting as an inductance as in the related art.

[0018]

According to the first aspect of the present invention, there is provided a shielded wire for winding a shield tape having a conductive surface on the outer periphery of an electric wire, and a drain wire is routed around the outer periphery of the electric wire in the axial direction. Then, the wire is bundled together with the electric wire, and a shield tape having conductive surfaces formed on the inner surface and the outer surface on the outer periphery of the electric wire and the drain wire is wound up to a position substantially corresponding to a terminal portion of the electric wire, so that it is continuous and uniform. The shield surface of the wire is formed even at the end of the electric wire, so it exhibits an excellent shield function especially in the high frequency range, and it can also exhibit an excellent shield function without creating a gap at the overlapping part of the shield tape, electronic equipment etc. Therefore, it is possible to reliably shut off noise generated from the device and external noise, and to operate the device accurately without malfunction, and to prevent trouble.

According to a second aspect of the present invention, as described in the first aspect, an insulating tape is wound around the outer periphery of the shield tape wound around the outer periphery of the electric wire, if necessary, or a sleeve or resin is used. Since it is covered with an exterior protective body made of a mold or the like, it protects the shielded electric wire to prevent intrusion of dust and the like, and has excellent electrical insulation properties and high watertightness.

[Brief description of the drawings]

FIG. 1 is a partially enlarged sectional view in a longitudinal direction showing an embodiment of a shielded electric wire of the present invention.

FIG. 2 is a longitudinal sectional view of the same.

FIG. 3 is an enlarged cross-sectional view for explaining a shielding effect of two shield layers constituting the embodiment.

FIG. 4 is a perspective view showing a conventional shielded electric wire.

FIG. 5 is a partial enlarged sectional view of the shielded electric wire in the longitudinal direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric wire 2 Conductor part 3 Coating part 4 Shield tape 5a Conductive surface 5b Conductive surface 6 Drain wire T terminal T 'terminal

Claims (2)

[Claims] 1. A shielded electric wire wound around a shield tape having a conductive surface on an outer periphery of an electric wire, a drain wire is routed around the outer periphery of the electric wire in an axial direction and bundled together with the electric wire. What is claimed is: 1. A shielded electric wire, wherein a shield tape having a conductive surface formed on an inner surface and an outer surface on a periphery of a drain wire is wound up to a position substantially corresponding to a terminal portion of the electric wire. 2. An outer periphery of a shield tape wound around an outer periphery of an electric wire, if necessary, may be wound with an insulating tape or covered with an outer protective body made of a sleeve, a resin mold or the like. The shielded electric wire according to claim 1.