JP3047572B2 - Flat circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat circuit body such as a flat cable used for wiring in an automobile or wiring of electronic equipment, and more particularly to an induced voltage caused by a magnetic flux crossing the flat circuit body and the flat circuit body. The present invention relates to a flat circuit body suitable for reducing noise caused by a radiated magnetic field generated by a current flowing through a flat conductor.

[0002]

2. Description of the Related Art Wiring and electronic equipment in a motor vehicle include a digital signal for operating an internal logic circuit and a signal line for input / output signals exchanged between external equipment and the like. A power supply line, a ground line, and the like for supplying power to the power supply are built in. For this reason, various measures have been taken to prevent digital signals and the like from being subjected to noise due to magnetic flux generated by a large current or the like flowing through the power supply line.

As one of such measures, as shown in FIG. 9 , two electric wires 101, 1 called so-called twisted pair wires are used.
There is a method using a cable obtained by twisting 02.

When a twisted pair wire as shown in FIG. 9 is used,
As shown in FIG. 10 , even when a magnetic flux A crossing the twisted pair wire is generated, induced voltages V and V ′ in opposite directions are generated in the same electric wire 101 and electric wire 102 for each adjacent section. Therefore, in the electric wires 101 and 102, the induced voltages V and V 'in the respective sections cancel each other, and a large induced voltage is not generated as a whole. Further, according to the twisted pair line in FIG. 9, arrow C, D in FIG. 11
As shown by, when a current flows in the electric wire 101 and the electric wire 102 in the opposite direction, a magnetic flux in the opposite direction is generated in each of the adjacent sections, and these adjacent magnetic fluxes cancel each other out. No magnetic field is formed outside.

As shown in FIG. 12 , a through hole 202 is provided in the insulating layer 201 of the twisted pair wire, and two flat conductors 203 and 204 are connected to the through hole 20 as shown in FIG.
2 so as to be entangled three-dimensionally while being alternately shifted from one surface to the other surface of the insulating layer 201 via
There are also flexible printed circuit type twisted pair wires.

[0006]

However, since the twisted pair wire as shown in FIG. 9 is formed by tangling two wires, it is difficult to determine which wire is used at the terminal. In addition, the rigidity of the terminal as a whole is extremely low and the terminal is easy to unravel, so that it is difficult to position the terminal. For this reason, the twisted pair wire as shown in FIG. 9 has a problem that it is difficult to automate the work of mounting the connector.

Further, when the twisted pair wire of FIG. 9 is used in combination with a flexible printed circuit or a printed circuit board, the advantage of the flexible printed circuit or the like concerning space saving and simplification of work is diminished. There are also problems.

On the other hand, in a flexible printed circuit type twisted pair wire as shown in FIG. 12 , flat conductors 203 and 204 are transferred from one surface of the insulating layer 201 to the other surface via the through hole 202 in the manufacturing process. because it is difficult task of shifting is required, production cost is costly, product cost as a result there is a problem that you have and rises.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and it is possible to obtain the same noise suppression effect as that of a conventional twisted pair wire, but it is easy to mount a connector. It is another object of the present invention to provide a flat circuit body which can be manufactured at a relatively low cost.

[0010]

A flat circuit body according to the present invention for achieving the above object is a flat circuit body having a pair of flat conductors disposed via an insulating layer, wherein the pair of flat conductors are both provided. It is meandering in a wave shape along the surface of this flat circuit body, and
Flat conductor and the other of the flat conductors is viewed in a direction perpendicular to the surface direction of the flat circuit body, between two points to each other intersect and form a region surrounded by one of the flat conductors and the other flat conductor It is characterized by:

[0011]

According to the flat circuit body of the present invention as described above, when a magnetic flux is generated in a direction intersecting the plane direction of the flat circuit body, one flat conductor is moved from the intersection with the other flat conductor to the next. In the one area reaching the intersection and the next section adjacent to this area, opposite induced voltages are generated, which cancel each other out. Also, when current flows in opposite directions in the two flat conductors,
In two adjacent regions, magnetic fluxes in opposite directions are generated in directions intersecting with the plane of the flat conductor, and these mutually cancel each other, thereby intersecting with the plane of the flat conductor formed outside by the current. The radiation magnetic field in the direction is suppressed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The flat cable according to the invention shown in FIG.
A flat conductor 11 and a flat conductor 12 are provided. An insulating film 13 is interposed between the flat conductor 11 and the flat conductor 12. This insulating film 13
Has the flat conductor 12 interposed between it and the insulating film 14. The insulating film 13 and the insulating film 14 are bonded together with the flat conductor 12 by an adhesive layer 15 interposed between the insulating films 13 and 14.

Both of the flat conductors 11 and 12 meander in a sine wave shape. Each flat conductor 11, 1
2 meanders with the same axis a as a reference line when the flat conductors 11 and 12 are viewed from a direction orthogonal to the plane direction of the flat cable. Further, the sine wave formed by the one flat conductor 11 and the other flat conductor 12 is symmetric with respect to the axis a, as shown in FIG. Therefore, in this flat cable, when viewed from a direction orthogonal to the surface direction, the flat conductor 1
A region T surrounded by the flat conductor 11 and the flat conductor 12 is formed between the intersection points P of 1 and 12.

In the flat cable constructed as described above, as shown in FIGS. 2B and 2C which are sectional views taken along lines IIb-IIb and IIc-IIc in FIG. When a magnetic flux W intersects at an intersection angle θ (see FIG. 2B), the magnetic flux W causes the magnetic flux W shown in FIG.
As shown in (1), induced voltages V1 and V2 whose directions are reversed for each adjacent region T are generated on each flat conductor 11 and each flat conductor 12. As described above, since the induced voltages V1 and V2 in the opposite directions are generated alternately in each of the adjacent regions T, even if the magnetic flux W is generated in a direction intersecting the plane direction of the flat cable, the circuit conductors 11 and 1
2 as a whole, almost no induced voltage, that is, no noise is generated.

As is apparent from the above description, in the flat cable as shown in FIG.
1 and an insulating film 1 interposed between the flat conductors 12
The smaller the thickness of 3 is, the smaller the intersection angle θ at which the induced voltages V1 or V2 in opposite directions that cancel each other out can be generated. That is, as the thickness of the insulating film 13 is reduced, the directivity of the noise suppressing action is reduced, and the noise suppressing effect is improved.

According to the flat cable shown in FIG. 1, when currents I1 and I2 in opposite directions flow through the flat conductor 11 and the flat conductor 12, as shown in FIG.
As shown in FIGS. 3B and 3C, which are sectional views taken along lines IIIb-IIIb and IIIc-IIIc in FIG. Magnetic fluxes W1 and W2 in opposite directions are sequentially generated. Therefore, in this flat cable, even if the currents I1 and I2 flow, the magnetic field extending in the direction intersecting the plane is small, and the induction of noise in other digital signal lines or the like existing in the direction intersecting the plane is suppressed. .

As shown in FIG. 4, the flat cable shown in FIG. 1 is formed by bonding an insulating film 13 provided with a flat conductor 11 on one surface and an insulating film 14 provided with a flat conductor 12 on one surface with an adhesive ( 4 (not shown in FIG. 4).

As shown in FIG. 4, when an insulating film 13 provided with a flat conductor 11 on one surface and an insulating film 14 provided with a flat conductor 12 on one surface are superposed, the insulating films 13 and 14 are used. May be fixed to each other by means other than bonding with an adhesive, for example, heat welding. Also, the insulating films 13, 1
When both of the insulating films 13 and 14 are arranged at locations where little displacement occurs, the insulating films 13 and 14 need not be fixed to each other.

The flat cable shown in FIG. 1 employs an insulating film 13 as an insulating layer interposed between the flat conductor 11 and the flat conductor 12. The insulating layer is made of other material such as insulating paint. An insulating layer formed of the insulating material described above may be used.

In the flat cable shown in FIG. 1, the flat conductor 11 and the flat conductor 12 are connected to one insulating film 13.
In this case, it is easy to reduce the thickness of the insulating film 13 and reduce the directivity of the noise suppressing action. However,
The flat circuit body according to the present invention is not necessarily limited to the configuration shown in FIG. Hereinafter, another flat circuit body according to the present invention having a noise suppression effect substantially similar to that of the flat cable of FIG. 1 will be described.

The flat circuit body shown in FIG. 5 has flat conductors 21 and 22 provided via two insulating films 23a and 23b. The flat conductors 21 and 22
Are the flat conductors 11, 12 of the flat cable of FIG.
Similarly to the above, these flat conductors 21 and 22 meander symmetrically with respect to the same axis when viewed from a direction orthogonal to the plane direction of the flat circuit body. Further, when viewed from a direction orthogonal to the plane direction of the flat circuit body, between the points where the flat conductors 21 and 22 intersect,
The flat conductor 21 and the flat conductor 22 form a region similar to the region T in FIG.

As shown in FIG. 6, a flat cable as shown in FIG.
Sine wave flat conductors 22 and 21 meandering in exactly the same phase are mounted at predetermined intervals, and then the insulating film 23 is attached to the middle of the flat conductors 22 and 21 so that the back surfaces of the insulating films 23 are in close contact with each other. Can be formed by folding back. The back surfaces of the insulating films 23 are bonded together with an adhesive (not shown) or the like. The insulating film 23 on the tip side from the folding line b constitutes the insulating film 23b in FIG.
The insulating film 23 on the back side of the folding line b is shown in FIG.
Needless to say, this constitutes the insulating film 23a.

[0023]

FIG. 7 shows an example in which a flat circuit body F according to the present invention is applied to a wiring in a junction box provided for performing electric wiring between an electronic unit and a relay box in an automobile. This figure
The junction box 7 forms an electric wiring portion in a space formed by fitting the upper case U and the lower case L, and the flat circuit body F is disposed in this electric wiring portion. As in the case shown in FIG. 4, the flat circuit body F employed in this junction box has an insulating film 43 on which a circuit conductor 41 is also mounted on an insulating film 43 on which a circuit conductor 42 is mounted. This is a flat circuit body formed by stacking, and the insulating films 43 and 44 are fixed by an adhesive or the like. The circuit conductors 41 and 42 are both branched at one end into two lines, but each of the lines is meandering in a sine wave shape. Further, as shown in FIG. 8, the circuit conductors 41 and 42
Is the same as the flat conductors 11 and 12 shown in FIG.
Meandering symmetrically with respect to. In the junction box shown in FIG. 7 , wiring pins (not shown) designated by the upper case U and the like are connected to terminal portions 41a and 42a provided at ends of the circuit conductors 41 and 42. ing. In the junction box as shown in FIG. 7 , one of the insulating films 43 of the flat circuit body F may be fixed to the inside of the lower case L of the junction box in advance.

The flat circuit member according to the invention as shown in FIG. 1 or the like, not only the junction box shown in FIGS. 7 and 8, for example, as a door harness runs a car door, can not afford to installation space It can also be suitably adopted as a noise countermeasure wiring at a location. That is, in a car equipped with a high-grade audio system, such as a recent car, a speaker may be provided at the door. However, as a wiring connected to such a speaker, the flat cable according to the above-described invention is used. When a circuit body is used, noise due to a power supply line or the like constituting a harness provided in the door can be significantly reduced, and sound quality emitted from a speaker can be improved.
In the case of wiring inside the door of an automobile, the influence of magnetic flux from outside the vehicle body does not cause much problem due to the shielding action of the iron plate forming the door. Therefore, by using a circuit body capable of suppressing noise due to magnetic flux in a direction intersecting with the surface direction, as in the flat circuit body according to the present invention, noise due to magnetic flux generated in the door is suppressed, thereby achieving a sufficient noise suppression effect. Obtainable.

In the flat circuit body shown in FIG. 1 and the like, since each circuit conductor is provided along the surface of the insulating layer, any of the circuit conductors can be easily determined at the terminal portion of the flat circuit body. Can be determined. Further, since the circuit conductors can be easily identified and the circuit conductors are supported by an insulating layer, there is an effect that the work of attaching the connector to the terminal portion is also easy. .

[0027]

According to the flat cable according to the invention,
When a magnetic flux is generated in a direction intersecting with the plane direction of the flat cable, the generation of noise can be suppressed in substantially the same manner as the twisted pair.

Further, since it is what the flat conductor is provided on one surface and the other surface of the flat cable, Fra
The conductor can be easily identified, and the work of mounting the connector is easy.

Further, since there is no structure in which the flat conductor penetrates the insulating layer, there is an effect that the manufacturing cost can be relatively low.

[Brief description of the drawings]

FIG. 1 is a perspective view of a flat cable according to the present invention.

FIG. 2 is an explanatory diagram showing a case where the flat cable of FIG. 1 is viewed from a direction intersecting a surface.

FIG. 3 is an explanatory diagram showing a case where the flat cable of FIG. 1 is viewed from a surface direction.

FIG. 4 is an explanatory view showing a method of manufacturing the flat cable of FIG.

FIG. 5 is a perspective view showing another flat cable according to the invention.

FIG. 6 is an explanatory view showing a method of manufacturing the flat cable of FIG.

FIG. 7 is a perspective view showing an example of use of the flat cable according to the invention.

FIG. 8 is an explanatory diagram showing a state where the flat cable shown in FIG. 7 is viewed from a direction orthogonal to a surface.

FIG. 9 is a diagram showing a conventional twisted pair wire.

FIG. 10 is an explanatory diagram showing a noise suppressing action of the twisted pair wire shown in FIG. 9 ;

FIG. 11 is an explanatory view showing an action of suppressing the generation of magnetic flux of the twisted pair wire shown in FIG. 9 ;

FIG. 12 is a view showing a conventional flat cable type twisted pair wire.

[Explanation of symbols]

11, 12 Flat conductor 13, 14 Insulating film 21, 22 Flat conductor 23a, 23b Insulating film 31, 32 Electric wire 33, 34 Insulating film 41, 42 Circuit conductor 43, 44 Insulating film F Flat circuit body T area

Claims (1)

(57) [Claims] A pair of flashes arranged via an insulating layer.
A flat circuit body provided with bets conductor, the pair of the flat conductor is meandering in a wave shape both along the surface of the flat circuit body, and one of the hula
Tsu DOO conductor and the other of the flat conductors is viewed in a direction perpendicular to the surface direction of the flat circuit body, between two points to each other intersect, forming a region surrounded by one of the flat conductors and the other flat conductor A flat circuit body.