JP2002170444A - Short-circuit alarm device for electric wires - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a short-circuit alarm device that is possible to prevent in advance electric wire shorting in wire harness. SOLUTION: Insulated electric wires 8, 9 and 10 to supply electricity from a power source 1 to circuits, and the wires are covered with coverings 11, 12 and 13 surrounding inside of electric conductors. A short-circuit alarm device 15 is connected between the electric conductor inside the electric wire coverings 11, 12 and 13 and a positive terminal of the power source 1. The short-circuit alarm device 15 issues an alarm for shorting prediction when the device detects electric currents which flows in the electric conductor. According to this alarm, it is possible to prevent short-circuit accident on the electric wires 8, 9 and 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for a short circuit of an electric wire such as a wire harness (assembled electric wire) in a power supply circuit, and more particularly to a short circuit alarm device for an electric wire which predicts a short circuit of an electric wire and issues an alarm. Things.

[0002]

2. Description of the Related Art For example, a grounding circuit of an automobile has a structure in which the body is grounded. Therefore, when a conductor of a wire harness that supplies power from a power source to each auxiliary machine comes into contact with the body, a short circuit is formed. It is formed and an overcurrent flows. For this reason, this kind of power supply circuit for automobiles is provided with a cutoff circuit for cutting off the circuit when such a short circuit is formed.

FIG. 6 is a circuit diagram showing an example of a wiring structure of a conventional general automobile power supply circuit. In FIG. 6, the power supply 1 is connected to each of the circuits (auxiliary devices 5a to 5c) in the automobile.
Is a battery that supplies electric power (DC current) to the battery.
The negative terminal of the power supply 1 is grounded (grounded) to the body via a ground line 8, and the positive terminal is connected to each circuit via a power supply line 9, a large-capacity fuse 2, and a wire harness 10 for supplying power. ing. The large-capacity fuse 2 is intended to prevent the wire harness 10 from being burned or a vehicle fire from being caused by the overcurrent flowing by fusing with heat when the overcurrent flows.

[0004] Each circuit in an automobile is formed by connecting fuses 3a to 3c, switches 4a to 4c, and auxiliary devices 5a to 5c in this order in series from the power supply side to the ground side. The fuses 3a to 3c of each circuit are blown by heat when an overcurrent flows, thereby preventing the wire harness 10 from burning. The switches 4a to 4c are connected to the power supply 1
To turn on / off the supply of power to the auxiliary devices 5a to 5c of each circuit. The auxiliary devices 5a to 5c are, for example, devices such as a lamp, a motor, and a heater in an automobile.

In the above-described power supply circuit, a wire harness 10 connecting the power supply 1 and each circuit includes a metal part,
For example, when the coating of the wire harness 10 is broken by vibrations while the vehicle is running in contact with the placket or the body, as shown in FIG. 7, the conductor portion of the wire harness 10 comes into contact with the metal portion of the ground potential, A short circuit may occur at this contact portion. In this case, in the above-described power supply circuit, depending on the large-capacity fuse 2 or the location of the short circuit, the fuses 3a to 3c cut the short circuit and open the circuit, so that the overcurrent from the power supply 1 is stopped. As a result, the wire harness 10
Is prevented from being burned.

[0006]

However, in the above-described conventional power supply circuit, when a short-circuit accident occurs and the large-capacity fuse 2 or the fuses 3a to 3c are blown, the circuit is cut and opened. In addition, there is a problem that a circuit in which a failure or the like has not occurred cannot be used. Therefore, it is desirable to predict in advance the short-circuit of the wire harness 10 in order to prevent the circuit from being opened and becoming unusable.

If a short circuit occurs intermittently in a part of the wire harness 10 due to vibration during driving of the automobile, etc., the large capacity fuse 2 and the fuse 3
In some cases, the circuit cannot be cut by the large-capacity fuse 2 and the fuses 3a to 3c without an overcurrent sufficient to cut the a to 3c. In this case, the electric current flowing through the wire harness 10 may cause the wire harness 10 to burn out.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an electric wire short-circuit alarm device capable of preventing the occurrence of an electric short circuit in a wire harness or the like. I do.

[0009]

According to the present invention, there is provided an electric wire short-circuit alarm device, comprising: an insulated wire for supplying power from a power source to a circuit; and a conductor disposed inside the wire so as to surround the wire. Wire covering, which is connected between the conductor inside the wire covering and the positive terminal of the power supply,
A short-circuit warning unit that detects a current flowing through the conductor and issues a warning for short-circuit forecast.

According to the electric wire short-circuit alarm device of the present invention, when the electric wire covering the electric wire is broken by the influence of the vibration of the automobile, etc., before the conductor portion in the electric wire comes into contact with the metal portion, The conductor inside the electric wire covering provided so as to surround the electric wire comes into contact with the metal part, and the current flowing through the conductor is detected by the short-circuit alarm unit, and an alarm is issued from the short-circuit alarm unit. As a result, it is possible to predict the occurrence of a short circuit before the fuse is blown and the circuit is opened, and by taking measures against it, it is possible to prevent a short circuit accident, Can be prevented from burning.

As the electric wire covering, for example, an electric conductor formed of a braided wire can be used. With this configuration, when a short circuit occurs, the current reliably flows through the braided wire, and the current can be reliably detected by the short-circuit alarm unit.

Further, the electric wire coating may be formed with an adhesive tape on the inner surface, and a metal foil adhered to the inner surface of the adhesive tape may be used as a conductor. In this case, the wire covering can be easily formed simply by winding the tape around the wire.

Further, as the short-circuit warning unit, a unit configured to emit a warning by lighting a lamp can be used. As a result, it is possible to reliably notify the user of a sign of the occurrence of a short circuit.

[0014]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG.
It is a circuit diagram showing the composition of the electric power supply circuit for vehicles provided with the electric wire short circuit warning device concerning a 1st embodiment of the present invention.

In FIG. 1, a power supply 1, a large-capacity fuse 2, fuses 3a to 3c, switches 4a to 4c, and accessories 5a to 5c are the same as those shown in FIGS. Also, a point at which the ground wire 8 connects the negative terminal of the power supply 1 to the ground, a point at which the power supply line 9 connects the positive terminal of the power supply 1 and the large-capacity fuse 2, and a wiring harness 10 via the large-capacity fuse 2 Fuses 3a-3 from power supply 1
6B and 7C, power is supplied to each circuit including the switches 4a to 4c and the auxiliary devices 5a to 5c.

In the power supply circuit for an automobile according to the present embodiment, a ground line 8, a power line 9 and a wire harness 10 are provided.
Are covered with a ground wire cover 11, a power supply wire cover 12, and a harness cover 13, respectively. These coatings 1
Nos. 1 to 13 are formed by arranging a braided wire made of a metal such as copper, which is a conductor, so as to surround each electric wire. For example, FIG. 3 shows a wire harness 10 and a harness coating 13.
2 shows a cross section of FIG. Each electric wire constituting the wire harness 10 includes an electric wire portion 10A and an insulating coating 10 covering the electric wire portion 10A.
B. The harness coating 13 surrounds the wire harness 10 and includes an inner braided wire 13A and an outer insulating coating 13B. Braided wire 1
3A is made of a braided wire of a metal such as copper. The ground wire cover 11 and the power supply wire cover 12 have basically the same configuration.

The braided wires 12A (not shown) and 13A inside the power supply wire coating 12 and the harness coating 13 are connected to each other by a joint wire 14, and these are connected to the ground wire coating 11.
Together with the braided wire 11A (not shown). The other terminal of the short-circuit alarm 15 is connected to the positive terminal of the power supply 1 directly or via the power supply line 9. The short-circuit alarm 15 is, for example, a lamp,
It is composed of a buzzer or the like, and emits an alarm by light, sound, or the like when conducting. The ground wire cover 11, the power supply wire cover 12, the harness cover 13, the joint wire 14, and the short-circuit alarm 15 constitute an electric wire short-circuit alarm device according to the present invention.

Next, the operation of the electric wire short-circuit alarm device configured as described above will be described with reference to FIG. FIG.
As shown in FIG. 5, the ground wire 8, the power supply wire 9 and the wire harness 10 come into contact with a metal part such as a body due to vibrations during driving of the automobile, etc., and any one of the insulating coatings 11 to 13;
For example, in the example of FIG. 2, when the insulating coating 13B is torn and the braided wire 13A at the broken portion of the insulating coating 13B comes into contact with the body, the power supply 1 to the power supply line 9, the short-circuit alarm 15, and the power supply line cover 12 are braided. A circuit is formed which is grounded to the body through the wire 12A, the joint wire 14 and the braided wire 13A of the harness coating 13, and a DC current from the power supply 1 flows through this circuit. When detecting the direct current, the short-circuit alarm 15 turns on a lamp in the apparatus as shown in FIG. 2 to warn the user to urge the user to repair. Therefore, the user can know the possibility of disconnection of the ground wire 8 and the possibility of short-circuit to the body ground of the power supply line 9 and the wire harness 10 by turning on the lamp of the short-circuit alarm 15. . As a result, the ground wire 8
Disconnection or short circuit of the power supply line 9 and the wire harness 10 can be prevented beforehand.

As described above, according to this embodiment,
The surroundings of the ground wire 8, the power supply wire 9, and the wire harness 10 are covered with a ground wire cover 11, a power supply wire cover 12, and a harness cover 13 in which braided wires are disposed inside, and the braided wires on the inner side serve as a body ground. Since the short-circuit alarm 15 detects the short-circuit and gives an alarm, it is possible to foresee before the electric wire such as the wire harness 10 is short-circuited to the body ground, and to detect the short-circuit.
Are short-circuited, and the large-capacity fuse 2 or the fuses 3a to 3c
It can be prevented before the circuit breaks and the circuit becomes open.

In this case, even if the ground wire 8, the power supply wire 9 and the braided wire of the wire harness 10 are intermittently short-circuited, a current flows intermittently through the short-circuit alarm 15,
Since the alarm is issued, the possibility of the intermittent short-circuit of the wire harness 10 or the like can also be notified to the user, and the intermittent short-circuit of the wire harness 10 or the like can be prevented, and as a result, Burnout of the wire harness 10 and the like due to intermittent short circuits can be prevented.

In the above embodiment, the ground wire coating 1
1, a braided wire was used as a conductor inside the power supply wire coating 12 and the harness coating 13, but the conductor is not limited to such a configuration. Instead of the braided wire, a copper foil or the like is used for the wire harness 10 or the like. You may comprise so that it may wind around and cover.

FIG. 4 is a view showing an adhesive tape wound around a wire harness 10 which can be used as another embodiment of the present invention. FIG. FIG. 4 is a view showing a step of forming a slab. As shown in FIG. 4, a copper foil 2 as a conductor is provided at the center of the adhesive surface of the vinyl adhesive tape 21B.
1A is attached.

The harness coating 21 is formed by winding the adhesive tape 21B with the copper foil 21A around the wire harness 10. Thereby, the periphery of the wire harness 10 is covered with the copper foil 21A,
The periphery of 1A is covered with the adhesive tape 21B. In such a configuration of the harness coating 21, as described in the above embodiment, when a short circuit occurs, a current flows through the copper foil 21A, and the short circuit can be detected and an alarm can be issued.

In FIGS. 4 and 5, the adhesive tape 21B is used.
Although the copper foil 21A is stuck on the inner surface of the above, another metal foil other than the copper foil 21A may be used.

As described above, according to this embodiment, the adhesive tape 21 with the copper foil 21A is attached to the wire harness 10.
Simply by winding B, the electric wire cover 21 can be easily formed.

In the present invention, a single-core or multi-core shielded wire may be used as a configuration in which the insulated wire is further covered with the wire coating.

[0027]

As described above, according to the present invention, when the electric wire covering the electric wire is broken due to the vibration of an automobile or the like, the conductor portion in the electric wire comes into contact with the metal portion before contacting the metal portion. The electric conductor inside the electric wire covering provided so as to surround the electric wire comes into contact with the metal part. As a result, the current flowing through the electric conductor is detected by the short-circuit alarm unit, and an alarm is issued from the short-circuit alarm unit. As a result, it is possible to predict the occurrence of a short circuit before the fuse is blown and the circuit is opened, and by taking measures against it, it is possible to prevent a short circuit accident, Can be prevented from burning.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a normal configuration of an automobile power supply circuit including an electric wire short-circuit alarm device according to an embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram of the same circuit at the time of a short circuit alarm.

FIG. 3 is a sectional view showing a structure of a wire harness and a harness covering.

FIG. 4 is a diagram showing an adhesive tape wound around a wire harness.

FIG. 5 is a diagram showing a step of winding an adhesive tape around a wire harness to form a harness coating.

FIG. 6 is a circuit diagram showing an example of a normal wiring structure of a conventional power supply circuit for a vehicle.

FIG. 7 is an equivalent circuit diagram when a short circuit occurs in the circuit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Power supply 2 ... Large capacity fuse 3a-3c ... Fuse 4a-4c ... Switch 5a-5c ... Auxiliary equipment, 8 ... Ground wire, 9 ... Power supply wire, 10 ... Wire harness, 11 ...
Ground wire coating, 12 power supply wire coating, 13, 21 harness coating, 13A braided wire, 13B insulating coating, 14 joint wire, 21A copper foil, 21B adhesive tape.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // H01B 7/00 301 H02G 3/28 F (72) Inventor 1440 Address Fujikura Co., Ltd. Sakura Office F-term (reference) 2G014 AA03 AA04 AB24 AB31 AB38 AC15 5G309 AA11 5G315 BA02 5G363 AA09 BA02 DC02

Claims (4)

[Claims] An electric wire covering for covering an insulated electric wire for supplying electric power from a power source to a circuit and arranging a conductor inside so as to surround the electric wire, and a conductor inside the electric wire cover. A short-circuit alarm unit, which is connected between a positive terminal of the power supply and detects a current flowing through the conductor and issues an alarm for short-circuit forecast. 2. The electric wire short-circuit alarm device according to claim 1, wherein the electric wire covering is formed by braiding the conductor. 3. The electric wire short-circuit alarm device according to claim 1, wherein the electric wire covering is made of an adhesive tape, and the conductor is a metal foil attached to an inner surface of the adhesive tape. 4. The electric wire short-circuit alarm device according to claim 1, wherein the short-circuit alarm section turns on a lamp to issue an alarm.