JP3398324B2 - Electric wire current detection sensor and current detection system using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current detection sensor for preventing and protecting from abnormal heat generation due to overcurrent of electric wiring, local heat generation due to disconnection, and damage due to short circuit, and a current detection sensor for the same, particularly in a vehicle such as an automobile. The present invention relates to a current detection system.

[0002]

2. Description of the Related Art As a conventional example of this type of device, a vehicle fire prevention device shown in FIG. 7 (Japanese Patent Laid-Open No. 61-139216).
Discloses a system in which a current sensor 2 is provided in a wire harness that connects a power supply battery 1 and a load 7, and the power is turned off or an alarm is issued when an abnormality occurs. In this case, the change in the current flowing through the wire harness is divided into several levels with respect to the current level during normal ON / OFF operation of the load 7, the current level when the load 7 is completely short-circuited, and the current level when the load 7 is intermittently short-circuited. Detected for each current level. When the control means based on the waveform identification circuit 5 or the like judges an abnormality for each of these current levels, the breaker 6 is turned off to turn off the current, and an alarm signal output from the alarm device 8 is used to notify.

[0003]

By the way, in the device described in the publication shown in FIG. 7, the current sensor 2 does not operate unless an intermittent short circuit or a complete short circuit actually occurs beyond the insulation level. It is a system that cannot detect it. As a result, particularly in the case of a completely short-circuited current level, there is a disadvantage that the wire harness is damaged due to abnormal heat generation or the like before detecting the current level and cutting off the flow of the current for turning off the breaker 6.

In addition, as the changing current level, the load 7
Therefore, it is impossible to perform highly accurate detection and determination unless a plurality of current sensors 2 are installed so as to detect the current levels in a plurality of stages. Therefore, if a plurality of current sensors 2 are installed and attempted to correspond to them, there arises a problem that the cost rises by the number of installations.

Further, in the case of the current sensor 2 of such a system, there is a problem that the system is apt to malfunction due to the influence of noise from the load 7 and the electronic central control unit.

Therefore, the object of the present invention is to reduce the manufacturing cost and detect the level of the current flowing through the electric wire in several stages, so that the wiring of a vehicle such as an automobile can be protected from damage due to overcurrent or the like. To provide an electric wire current detection sensor and a current detection system using the same.

[0007]

According to a first aspect of the present invention, a current detecting sensor according to the present invention is formed so that an electric wire to be wired can be covered over a part of its length or its entire length, and it is hardly soluble in heat and can shrink heat. A long strip base material made of a resin film, and one end of a circuit pattern formed in a non-contact state with each other in the longitudinal direction of the surface of the base material serves as terminals electrically connected to the electric wires. A pair of electrode circuits for current detection, which is configured to be capable of outputting a change in current flowing in the electric wire from the terminal as an electric resistance signal between the pair of electrode circuits due to thermal contraction of the base material. ing.

With such a structure, by covering the electric wire with a long strip-shaped current detection sensor made of a resin film on which the electrode circuit is patterned, the cost can be reduced with a minimum number of sensors installed, and the change in the electric current flowing through the electric wire can be reduced. It can be detected by a change in electric resistance of the circuit pattern due to thermal contraction of the resin according to the current level.

Further, the current detection sensor according to claim 3 is configured such that the pair of electrode circuits are patterned in two rows in a non-contact state with each other over the entire length of one surface of the base material.

In this case, since the circuit patterns are formed in two rows on one base material as compared with the current detection sensor in which two sheets are bonded together, as in claim 2, the cost of the member and the manufacturing process are reduced. It is advantageous in terms of reduction.

Further, the current detection sensor according to the fifth aspect can be adopted in a vehicle body for wiring an electric wire, for example.

In this case, the base material heat-shrinks due to current changes at the time of a short circuit due to the interference with the vehicle body, at the time of an overcurrent, and at the time of a complete short circuit due to a disconnection, so that the electrical resistance signal due to contact or disconnection of a pair of electrode circuits Can be output.

On the other hand, according to a sixth aspect of the current detecting system, the electric current is detected in the electric wire based on a detection signal from the electric current detecting sensor and the electric current detecting sensor which detects the electric current flowing through the electric wire at every several levels. A control circuit for monitoring and controlling the flowing current, a power cutoff circuit for turning on / off the power supply to the electric wire according to an operation signal output from the control circuit, and a warning sound or a warning according to an alarm command signal output from the control circuit A display device including an alarm means that lights up and displaying the content of the alarm signal can be configured.

With such a system configuration, the electric current flowing through the electric wire is detected by the electric current detection sensor at each of several levels, and the control circuit monitors the electric current, and the display device displays the content of the alarm signal in response to the detected signal. By displaying and notifying, it is possible to prevent damage due to electric leakage, overcurrent or the like.

According to a seventh aspect of the current detection system, the control circuit includes a first abnormal current level, which is a short-circuit current when the electric wire leaks due to interference between the electric wire and the wiring equipment, and the electric wire. Stores an abnormal current value in three stages including a second abnormal current level which is an overcurrent when abnormal heat generation occurs and a third abnormal current level which is a complete short-circuit current when local heat generation occurs due to disconnection of the electric wire. For the current level storage means to be stored and for each current value of the first to third abnormal current levels stored in the current level storage means,
On the basis of the signal sent from the comparison judgment means, which compares the current value equivalent to the detection signal sent from the current detection sensor and judges whether or not they match,
It can be constituted by a control means or the like that sends an ON / OFF signal to the power cutoff circuit and sends an alarm command signal for displaying the content of the abnormality on the display device.

By configuring the control circuit in this manner, the current level flowing through the electric wire is monitored at each of three stages of the short-circuit current level, the overcurrent level, and the complete short-circuit current level, and displayed for each current level. Can be dealt with through
Not only can electric wires be protected, but wiring equipment such as automobiles can be protected in advance.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a wire current detection sensor and a current detection system using the same according to the present invention will be described in detail below with reference to the drawings.

1 (a) and 1 (b) are a perspective view and a plan view showing a state before and after forming the current detecting sensor 1 according to the first embodiment. The sensor 1 has two base films 2 and 3 on one side and the other side, which are formed by laminating two kinds of resin films having different coefficients of thermal expansion into a long strip shape and pasting them together. A heat shrinkable material such as a silicon resin film is used for the base material 2 on one side. The other base material 3 is made of an insoluble material, such as polyester, having a heat shrinkage ratio different from that of the other base material 2, and any material which is hardly soluble can be used. is there.

Electrode circuits 4 and 5 are pattern-formed on the surfaces of the base materials 2 and 3 facing each other by bonding by etching or printing. After bonding, as shown in FIG. 4, 5 are formed so as not to contact each other. At both ends of the electrode circuits 4 and 5, there are a total of four pairs of terminals 4a, 4b and 5a, 5b adjacent to each other, which have a long forward path and a long path on the strip-shaped long base materials 2 and 3, respectively. It is formed as a terminal.

As described above, the current detecting sensor 1 (hereinafter referred to as the tape sensor 1 for convenience) formed in a tape shape by being stuck together, as shown in FIG. It is used either by the length of the wire or by winding it over the entire length of the wire. An insulating tape 7 is further wound on the tape sensor 1 wound around the electric wire 6, and the covered protective electric wire 6 formed in this way is commonly referred to as an armored electric wire, etc., and is connected to various devices via an electric connector 8 connected at one end. Used by being electrically connected.

A total of four terminals 4a, 4b and 5a, 5b on the reciprocating path side of the electrode circuits 4, 5 in the tape sensor 1 respectively.
Are respectively connected to the electric connector 8 on the side of the electric wire 6 by four lead wires 9.

Incidentally, instead of the structure shown in FIG. 1C in which the tape sensor 1 is spirally wound around the electric wire 6, as shown in FIG.

FIG. 3 shows a current detection system 1 in which the electric wire 6 having the above-described structure is used by wiring it on a vehicle body such as an automobile.
It is a block diagram showing 0.

A control circuit 11 to which a detection signal of a change in electric resistance generated between the electrode circuits 4 and 5 is input, and the control circuit 11 includes a CPU (central control unit), a current level storage means, a comparison means and a control means. Etc.

The current level storage means stores and stores a preset number of abnormal current levels flowing through the electric wire 6.
In the present embodiment, the abnormal current level is, for example, the short-circuit current level (first abnormal current level) due to the interference leakage between the electric wire 6 and the vehicle body side, and the excess current when the overcurrent flows through the electric wire 6 and abnormal heat generation occurs. Current level (second abnormal current level)
And 3 depending on the disconnection resistance current level (third abnormal current level) when local heat generation occurs due to the disconnection of the electric wire 6.
It is in stages.

The comparison means compares the current value equivalent to the detection signal output from the tape sensor 1 with the current values of the first to third abnormal current levels stored in the current level storage means, It is determined whether the detected current value from the tape sensor 1 is one of the first to third abnormal current levels.

The control means performs processing on the basis of the determination signal output from the comparison means, and sends the control signal V1 as the processing result to the power cutoff circuit (breaker) 12 for on / off operation. When the off signal is sent to the power cutoff circuit 12, the power supply from the power battery (not shown) to the electric wire 6 is stopped.

Further, the current detection system 10 has a display device 13 such as an LCD (liquid crystal display device) for displaying an abnormality content, and can be equipped with an alarm device by a lamp lighting blinking system or an alarm warning sound system. .

Next, the operation of the tape sensor winding wire 6 of the first embodiment having the above structure will be described with reference to the block diagram showing the current detection system 10 of FIG.

The electric wire 6 is connected to a device or device of the vehicle body through an electric connector 8 at one end thereof and wired. The tape sensor 1 is electrically connected to the electric wire 6 through the four lead wires 9 by its four terminals 4a, 4b and 5a, 5b, and is constantly detected by the overcurrent detection system 10 through the electric connector 8. The signal is ready to be sent.

When the load due to the vehicle body side device is normally on / off during mounting and use, the rated current flows through the electric wire 6, and the tape sensor 1 detects it and controls the overcurrent detection system 10 at all times. It is sent to the circuit 11. Control circuit 11
Then, it receives the detection signal v from the tape sensor 1 and functions to constantly monitor the level of the current flowing through the electric wire 6.

Therefore, when the electric leakage occurs due to the interference between the electric wire 6 and the vehicle body side, the tape sensor 1 detects this by the change of the electric resistance value between the current circuits 4 and 5, and the detection signal of the control circuit 11 is detected. Send to voltage level storage means. The comparison means
The short-circuit current level stored in this voltage level storage means is compared with whether or not the current value equivalent to the detection signal sent from the tape sensor 1 matches. When it is determined that they match, it is determined that the first abnormal current level has occurred.

The control means of the control circuit 11 sends off signal V1 to the power cutoff circuit 12 based on the signal of the first abnormal current level output from the comparison means to stop the power supply to the electric wire 6. Take. Further, the display device 13 is supplied with a display command signal V2 for displaying the details of the abnormality that the leakage due to the first abnormal current level has occurred, and the warning device is issued with a warning means to prevent each of them. Can be encouraged.

When an overcurrent flows through the electric wire 6 and abnormal heat is generated, in the tape sensor 1, the electrode circuit 3 is caused by the difference in thermal contraction rate between the base materials 4 and 5, that is, the contraction difference in thermal strain. , 4 are close to each other even if they do not come into contact with each other. As a result, the electric resistance value between the electrode circuits 3 and 4 changes. The tape sensor 1 detects the change in the resistance value as a signal, outputs it, and sends it to the voltage level storage means of the control circuit 11. The comparing means compares the overcurrent level stored in the voltage level storage means with a current value equivalent to the detection signal sent from the tape sensor 1 to determine whether or not the current value is equivalent. When it is determined that they match, it is determined that the second abnormal current level has occurred.

The control means of the control circuit 11 sends off signal V1 to the power cutoff circuit 12 based on the signal of the second abnormal current level output from the comparison means to stop the power supply to the electric wire 6. Take. Further, the display device 13 is supplied with a display command signal V2 for displaying the abnormal heat generation of the electric wire 6 due to the second abnormal current level, and the warning device is issued with warning means to prompt preventive measures.

Further, when the electric wire 6 is broken, the electric wire 6 is locally heated. In that case, FIG.
As shown in FIG. 5, in the tape sensor 1, the patterns of the electrode circuits 4 and 5 are completely in contact with each other due to the difference in contraction of the thermal strain of the base materials 2 and 3 (the contraction part is shown by reference numeral 2A in the figure). (In the figure, the contact portion is indicated by reference numeral 4A). As a result, the electric resistance value between the electrode circuits 4 and 5 changes. Tape sensor 1
Detects and outputs the change in resistance value as a signal, and sends it to the voltage level storage means of the control circuit 11. The comparison means
It is compared whether or not the current level equivalent to the detection signal sent from the tape sensor 1 matches the disconnection current level stored in the voltage level storage means. When it is determined that they match, it is determined that the third abnormal current level has occurred.

The control means of the control circuit 11 provides means for sending an off signal to the power cutoff circuit to stop energization of the electric wire 6 based on the signal of the third abnormal current level output from the comparison means. Further, a display command signal indicating abnormal heat generation of the electric wire 6 due to the third abnormal current level is sent to the display device, and warning means is issued to the alarm device to prompt preventive measures.

As will be understood from the above, in the first embodiment according to the present invention, the electric wire 6 has the first abnormal current level at the time of occurrence of leakage, the second abnormal current level at the time of abnormal heat generation due to overcurrent, For example, the third abnormal current level at the time of local heat generation due to disconnection can be detected for each current level in three stages. Thereby, it is effective to prevent damage to the electric wire 6 due to abnormal heat generation by appropriately responding to the current level at each stage, and particularly to enhance safety in vehicle body wiring and the like.

On the other hand, FIGS. 5 and 6 show a current detecting sensor according to a second embodiment of the present invention.

In this case, as shown in FIG. 5, the long strip tape sensor 20 is composed of one long strip base material 21 of one kind having a required coefficient of thermal expansion made of a silicon resin film or the like. ing. On one surface side of the base material 21, two electrode circuits 22 and 2 are arranged in two rows in the tape length direction.
The pattern 3 is formed by etching or printing so that the 3 does not come into contact with each other. One ends of the electrode circuits 22 and 23 are formed as two adjacent terminals 22a and 23a, and the other ends are in contact with each other as indicated by reference numeral 24.

The tape sensor 20 formed in this way
As shown in FIG. 1C of the first embodiment, is used by winding only the length of the main part of the electric wire 6 or the entire length of the electric wire. An insulating tape 7 is further wound on the tape sensor 20 wound around the electric wire 6, and the covered protective electric wire 6 thus formed is electrically used as armor electric wire for various devices through an electric connector 8 connected at one end. Used by connecting.

The electrode circuit 22 in the tape sensor 20,
Two adjacent terminals 22a, 23a on one end side of 23 are 2
The lead wire 9 of the book is connected to the electric connector 8 on the side of the electric wire 6. The electric wire 6 having such a structure is used as a current detection system 10 shown in FIG.

The tape sensor 20 according to the second embodiment also has substantially the same operation as the tape sensor 1 according to the first embodiment. This will be described below with reference to the block diagram of the current detection system 10 of FIG.

The electric wire 6 is connected to an apparatus or device of the vehicle body via an electric connector 8 at one end thereof and wired. The tape sensor 20 is electrically connected to the electric wire 6 through the two lead wires 9 by the two terminals 22a and 23a on one end side of the electrode circuits 22 and 23, and is electrically connected to the electric current detection system 10 through the electric connector 8. Also becomes a state in which the detection signal can be transmitted at all times.

When the load due to the vehicle body side device is normally turned on / off during mounting and use, a rated current flows through the electric wire 6, and the tape sensor 20 detects it and constantly controls the overcurrent detection system 10. It is sent to the circuit 11. Control circuit 1
1 receives the detection signal from the tape sensor 1 and functions to constantly monitor the level of the current flowing through the electric wire 6.

Also in the second embodiment, the countermeasure when the short-circuit current level due to the leakage due to the interference between the electric wire 6 and the vehicle body side, that is, the first abnormal current level occurs is as described in the first embodiment. .

Next, when an overcurrent flows through the electric wire 6 and abnormal heat is generated, in the tape sensor 20, the base material 21 is thermally contracted, and the patterns of the upper and lower two rows of electrode circuits 22 and 23 come into contact with each other. Proximity, if not all. As a result, the electric resistance value between the electrode circuits 22 and 23 changes. Tape sensor 2
0 detects the resistance value change as a signal and outputs it,
As in the case of the embodiment, the control circuit 11 determines that this is an overcurrent level, that is, a second abnormal current level, and responds.

On the other hand, as shown in FIG. 6, when the electric wire 6 is broken, the base material 21 of the tape sensor 20 is thermally shrunk due to local heat generation in the electric wire 6, and the electrode circuit 22 corresponding to the shrunk portion 21a. , 23 patterns are completely broken. Based on, for example, no signal from the tape sensor 20 by the pattern circuit disconnection portions 22bd and 23b, the control circuit 1
In No. 1, the complete short-circuit current level at which the electric wire 6 is broken, that is, the third
Respond by judging that an abnormal current level has occurred.

[0049]

As described above, in the current detection sensor according to the present invention, the number of sensors installed is minimized by simply covering the electric wire with a long strip made of the resin film having the electrode circuit patterned. It is effective in detecting the change in the current flowing in the electric wire by the change in the electric resistance value of the circuit pattern due to the thermal contraction of the resin according to the current level.

Further, if such a current detection sensor is mounted on a wiring wire in a vehicle body of an automobile or the like and adopted as a current detection system for monitoring the control circuit for changes in the level of the current flowing through this wire, leakage short-circuiting due to interference with the vehicle body will occur. Time,
It is possible to accurately grasp the current change at overcurrent and at the time of complete short circuit due to disconnection, and by displaying the alarm content on the display device each time the current level is detected, it is possible to prompt an appropriate response. It is very effective not only for preventing damage but also for protecting wiring equipment bodies such as vehicle bodies.

[Brief description of drawings]

FIG. 1A to FIG. 1C are perspective views showing respective modes of mounting a current detection sensor of a first embodiment according to the present invention before, after, and after formation and winding around an electric wire. It is a figure, an assembly drawing, and an electric wire installation explanatory view.

FIG. 2 is a perspective view showing another embodiment in which a current detection sensor is covered with an electric wire.

FIG. 3 is a block diagram showing a current detection system using the current detection sensor-attached electric wire according to the first embodiment.

FIG. 4 is an explanatory view schematically showing a state in which a pair of electrode circuits are in contact with each other when the film base substrate is thermally contracted in the current detection sensor according to the first embodiment.

FIG. 5 is a plan view showing a current detection sensor according to a second embodiment of the present invention.

FIG. 6 is an explanatory view schematically showing a state in which a pair of electrode circuits are torn due to thermal contraction of a film base material at the time of wire breakage in the current detection sensor of the second embodiment.

FIG. 7 is a block diagram showing a conventional device.

[Explanation of symbols]

1 Tape sensor (current detection sensor) 2,3 Laminated film base 4, 5 patterned electrode circuit 4a-5a terminals 6 electric wires 7 insulating tape 8 electrical connectors 9 terminal lead wire 10 Current detection system 11 Control circuit 12 Power shutdown circuit 13 Display

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H02H 3/08-3/10 H02H 5/04 G01K 7/16-7/18

Claims (7)

(57) [Claims] 1. A long strip base material made of a resin film which is sparingly heat-resistant and heat-shrinkable and which is formed so as to cover an electric wire to be wired over a part or the entire length, and a base material for the base material. One end of the circuit pattern formed in a non-contact state with each other in the longitudinal direction of the surface includes a pair of electrode circuits for current detection which are terminals electrically connected to the electric wire, and the electric wire A current detection sensor, wherein a change in a flowing current can be output from the terminal as an electric resistance signal between the pair of electrode circuits due to thermal contraction of the base material. 2. The base material is composed of two adhered over the entire length, and one of the pair of electrode circuits is patterned on the adhesive surface of the base material on one side, and the base material on the other side. The current detecting sensor according to claim 1, wherein the other side of the electrode circuit is patterned on the adhesive surface of the material in a non-contact state with the other side. 3. The table base according to claim 1, wherein the pair of electrode circuits are patterned in two rows in a non-contact state over the entire length of one surface of the table base. Current detection sensor. 4. The pair of electrode circuits is electrically connected to the electric wire by connecting each terminal of the pair of electrode circuits to an electric connector to which one end of the electric wire is connected via a lead wire. Claim 1 characterized by the above.
The electric current detection sensor in any one of -3. 5. The base material heat-shrinks due to current changes during a short circuit due to an interference of the electric wire with a wiring device body, an overcurrent, and a complete short circuit due to a disconnection, so that the pair of electrode circuits come into contact with each other. Alternatively, the current detection sensor according to any one of claims 1 to 4, which outputs an electric resistance signal due to disconnection. 6. The current detection sensor according to claim 1, and a current flowing through the wire based on a detection signal from the current detection sensor that detects a current flowing through the wire at each of several levels. A control circuit for monitoring and controlling the current, a power cutoff circuit for turning on / off the power supply to the electric wire according to an operation signal output from the control circuit, and a warning sound or a warning lighting depending on an alarm command signal output from the control circuit And a display device for displaying the content of the alarm signal, the current detection system comprising: 7. The control circuit includes a first abnormal current level that is a short-circuit current when a leakage occurs due to interference between the electric wire and the wiring device body, and an overcurrent when an abnormal heat generation occurs in the electric wire. 2 current level storage means for storing and storing an abnormal current value at three stages including an abnormal current level and a third abnormal current level which is a complete short-circuit current when local heat generation occurs due to disconnection of the electric wire; For each current value of the first to third abnormal current levels stored in the storage means, a current value equivalent to the detection signal sent from the current detection sensor is compared to determine whether they match. Based on the comparison / determination means and the signal sent from the comparison / determination means, an ON / OFF signal is sent to the power cutoff circuit, and an alarm command signal for displaying the abnormality content is displayed on the display device. 7. The current detection system according to claim 6, further comprising: sending control means.