JP2002125310A - Discharge monitoring device - Google Patents

Abstract

(57) [Problem] To prevent continuous occurrence of arc discharge for a long time due to disconnection of a harness in a power supply circuit. SOLUTION: A discharge monitoring device constantly detects a current value or a voltage value supplied to a load, and sends a current value signal or a voltage value signal of the detected current value. When it is determined whether the current value or the voltage value is abnormal based on the current / voltage detecting means 11 and the current value signal or the voltage value signal sent from the current / voltage detecting means 11, and it is determined that the current value or the voltage value is abnormal. Determining means 1 that determines that arc discharge has occurred and controls switch means 3 to stop the supply of power from the power supply to the load.
3 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge monitoring device for monitoring occurrence of arc discharge due to disconnection or short circuit of a harness (electric wire) in a power supply circuit.

[0002]

2. Description of the Related Art FIG. 6 is a circuit diagram showing an example of a wiring structure of a general automobile power supply circuit. In FIG.
The power supply 1 is a battery that supplies power (direct current) to the load 5. The fuse 2 is used to prevent external devices and harnesses from being destroyed by overcurrent by being blown by heat when an overcurrent flows, and is connected between the power supply 1 and the switching device 3. I have.

Switching device (switch means) 3
Is a transistor that performs a switching operation (on / off operation) in accordance with a control signal, and is connected between the fuse 2 and the load 5. The switching device 3 may be configured by a power MOSFET, a mechanical switch, or the like in addition to the transistor.

The load control means 4 controls the switching operation of the switching device 3 by supplying a control signal to the switching device 3 to control the supply of a direct current from the power supply 1 to the load 5. The load 5 includes, for example, a lamp, a motor, a solenoid, a heater, and the like in an automobile.

In the above-described power supply circuit for an automobile, the load 5
Is operated, the load control means 4 supplies a control signal to the switching device 3 to turn on the switching device 3, thereby causing the load 5 to supply power (DC current) from the power supply 1. Conversely, when the load 5 is not operated, the load control unit 4 stops supplying the control signal to the switching device 3 and turns off the switching device 3, thereby supplying power (DC current) to the load 5. Cut off.

In the above-mentioned power supply circuit for a vehicle,
When the harness (electric wire) on the upstream side (power supply 1 side) of the load 5 is short-circuited, an overcurrent flows from the short-circuited portion to the outside without a DC current flowing through the load 5. In this case, it is prevented that the fuse 2 is blown and the overcurrent continuously flows.
This prevents breakage of the harness and external devices due to the overcurrent.

[0007]

However, in the above-described circuit, when the harness on the upstream side of the load 5 is short-circuited, the fuse 2 is blown and the overcurrent is stopped. As shown in FIG. 7B, when the harness on the upstream side (power supply 1 side) or downstream side (ground side) of the load 5 is disconnected, or as shown in FIG. If the harness on the side ()) breaks and the broken harness contacts the steel plate 7 of the body ground and short-circuits,
An arc discharge 6 occurs at the broken or short-circuited portion, and a current having a value lower than that in the normal operation of the load 5 flows (because no overcurrent flows), so that the fuse 2 does not blow.

Further, if a portion where the harness is broken or the like intermittently repeats contact and non-contact (referred to as an intermittent short),
The arc discharge 6 generated at that point continues for a long time. As described above, when the arc discharge 6 is continuously generated for a long time, there is a risk that a vehicle fire may occur due to the arc heat of the arc discharge 6 or the device may be destroyed.

In particular, due to recent environmental problems and demands for improved fuel efficiency, automobile equipment is changing from mechanical control to electric control (for example, power steering does not generate power at the engine speed, but Under such circumstances, the electric load of at most several hundred watts will reach 5 to 6 kilowatts (kW) in the future under these circumstances. Is expected. At the same time, from the viewpoint of increasing the efficiency of power supply, the voltage of the power supply 1 of the vehicle is changed from the current 14V to 42.
There is a movement to increase the voltage to about V.

During the operation of such a large power load, FIG.
When the harness is disconnected as shown in (c), the possibility of the arc discharge 6 is further increased, and the risk of a vehicle fire or the like is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and monitors the occurrence of arc discharge due to disconnection or short circuit of a harness in a power supply circuit to thereby prevent vehicle fire or equipment caused by arc discharge. It is an object of the present invention to obtain a discharge monitoring device capable of preventing the destruction of a battery.

[0012]

In order to achieve the above object, a first discharge starting device according to the present invention comprises a switch means for controlling the supply of power from a power supply to a load by performing a switching operation; Current detecting means for constantly detecting the supplied current value and outputting a current value signal of the detected current value; and determining whether the current value is abnormal based on the current value signal output from the current detecting means. Determining, when determining that there is an abnormality, determining that arc discharge has occurred, and determining means for controlling the switch means to stop the supply of power from the power supply to the load, and I do.

Further, the second discharge start device according to the present invention performs a switching operation to switch the power supply from the power supply to the load, and constantly detects the voltage value on the upstream side or the downstream side of the load. Then, based on the voltage value signal output from the voltage detection means and a voltage detection means for outputting a voltage value signal of the detected voltage value, it is determined whether the voltage value is abnormal, if it is abnormal When the determination is made, it is determined that an arc discharge has occurred, and a determination unit that controls the switch unit so as to stop the supply of power from the power supply to the load is provided.

Further, the third discharge start device according to the present invention performs a switching operation to switch the power supply from the power supply to the load, and to constantly detect the value of the current supplied to the load. Current / voltage detecting means for constantly detecting the voltage value on the upstream side or the downstream side of the load and outputting a current value signal of the detected current value and a voltage value signal of the voltage value, and output from the current / voltage detecting means. Based on the current value signal and the voltage value signal, it is determined whether or not the current value and the voltage value are abnormal. And determination means for controlling the switch means so as to stop the supply of power to the power supply.

According to the discharge monitoring device of the present invention, the occurrence of arc discharge caused by the disconnection or short circuit of the harness can be immediately detected by monitoring the current value and / or the voltage value. Fire and destruction of equipment can be prevented.

The arc discharge is generated, for example, when the current value signal is in a range of about 20% to 70% of the normal load current, or when the voltage value signal is about 30% of the normal power supply voltage. In many cases, this occurs when the current value signal and / or the voltage signal signal indicate such a value. Can be configured.

Further, the determination means is configured to determine whether or not the duration of the abnormal current or the abnormal voltage is equal to or longer than the switching time of the switch means. Can be prevented.

Further, when the determination means determines that an arc discharge has occurred, the display means displays a warning so that the power supply to the load is stopped because the arc discharge has occurred. Can be notified to the user, and as a result, the user can immediately notice the abnormal state and take a countermeasure at an early stage.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a block diagram showing a configuration of the discharge monitoring device according to the first embodiment of the present invention. The discharge monitoring device according to the first embodiment includes a current monitoring device 10 and a display unit 20.

Here, the current monitoring device 10 is a device that shuts down the current by detecting an abnormal current when the arc discharge 6 occurs, thereby preventing the arc discharge 6 from continuing. 11, a power supply unit 12, a determination unit 13, and a switching device 3.

The current detecting means 11 is connected between the fuse 2 and the switching device 3 and constantly detects the current value of the current flowing through the load 5 and outputs the detected current value signal (1) to the judging means 13 Circuit. The current detecting means 11 is constituted by, for example, a circuit for detecting a current value by detecting a potential difference generated by a current passing through the shunt resistor. The power supply unit 12 is a circuit that guides a current from the upstream side (the power supply 1 side) of the current detection unit 11 and supplies a current (power) for operating the determination unit 13 to the determination unit 13.

The determining means 13 determines whether or not the load 5 is operating, based on a control signal (2) for controlling the switching operation of the switching device 3 sent from the load controlling means 4, It is determined based on the current value signal (1) sent from 11 whether or not the arc discharge 6 is occurring. When it is determined that the arc discharge 6 is occurring, a control signal is sent to the switching device 3. To turn off the switching device 3,
A warning signal (3) is displayed on the display means 20 to display a warning.
Is a circuit that outputs.

When the warning signal (3) is input from the judging means 13, the display means 20 informs the user of the automobile that the power supply from the power supply 1 to the load 5 has been stopped due to the occurrence of arc discharge. Therefore, a warning display is performed.

The other configurations (power supply 1, fuse 2, load control means 4, and load 5) are described in FIG.
Since the configuration is the same as that of the power supply circuit shown in FIG.

Next, the operation will be described. FIG. 2 is a flowchart for explaining the operation of the discharge monitoring device according to the first embodiment of the present invention. It is assumed that the arc discharge 6 is generated on the downstream side (ground side) of the load 5 as shown in FIG. The load 5 is 1.5 kilowatts (kW), and the voltage of the power supply 1 is 42V.

The determining means 13 first determines whether or not the control signal (2) sent from the load control means 4 is a signal for turning on the switching device 3 (step ST).
1). Here, when the determination unit 13 determines that the control signal (2) is not a signal for turning on the switching device 3 (that is, a signal for turning off the switching device 3) (No in step ST1), the timer is reset. At the same time (step ST2), the switching device 3 is turned off (step ST3) so as not to supply power to the load 5 (to turn it off).

On the other hand, if the judging means 13 judges that the control signal (2) is a signal for turning on the switching device 3 (Yes in step ST1), then the current value signal sent from the current detecting means 11 It is determined whether (1) is normal or abnormal (step ST4).

The judging means 13 knows the current value of the normal load current flowing through the load 5 from the load 5 (1.5 kilowatts) and the voltage value of the power supply 1 (42 V). When it is determined that the current value signal (1) obtained is the current value of the load current in the normal state (step ST4).
No), the timer is reset (step ST5), and the switching device 3 is turned on to supply power to the load 5 (to turn it on) (step ST6).

On the other hand, when the arc discharge 6 occurs, as shown in FIG. 3, the current value of the current in the arc discharge 6 decreases to about 20% to 70% of the normal load current. When the arc discharge 6 ends completely, the current value of the current naturally becomes 0 A. Therefore, when the arc discharge 6 is occurring, the current detecting means 11 outputs about 20% to 70% of the normal load current.
% Of the current value signal (1) of the current value reduced to
Will be sent to

If the current value signal (1) sent from the current detecting means 11 is within the range of about 20% to 70% of the normal load current known in advance, the judging means 13 outputs the current value signal (1). ) Is determined to be abnormal (Ye in step ST4).
s), counting the timer, the duration T of the abnormal current
Is equal to or longer than the switching time t1 of the switching device 3 (step ST7).

Here, the switching time t1 of the switching device 3 refers to a transient time required for the switching device 3 to be switched from on to off or from off to on. This switching device 3
The switching time t1 is also stored in the determination means 13 in advance.

As described above, by judging whether or not the duration T of the abnormal current is equal to or longer than the switching time t1 of the switching device 3, the judging means 13 erroneously determines that the arc discharge has not occurred. It is possible to prevent the determination that the discharge has occurred.

The determination means 13 determines that the duration T of the abnormal current is longer than the switching time t1 of the switching device 3 (the duration T of the abnormal current is intermittently longer than the switching time t1 of the switching device 3). (Including the case), it is determined that the arc discharge 6 is occurring, and the switching device 3 is turned off to shut down the current (step ST
8) Send a warning signal (3) to the display means 20 to cause the display means 20 to display a warning to the user (step ST9).

In this case, the object can be achieved if the arc discharge 6 can be prevented. Therefore, the judging means 13 does not shut down the current completely but reduces the current value so that the arc discharge 6 does not occur. You may comprise so that it may control.

On the other hand, the determination means 13 determines that the duration T of the abnormal current is the switching time t1 of the switching device 3.
If it is determined that the following conditions are satisfied, it is determined that the arc discharge 6 has not occurred, and as described above, the switching device 3 is turned on to supply power to the load 5 (to turn it on). (Step ST6).

As described above, according to the first embodiment, the determining means 13 determines whether or not the arc discharge 6 has occurred based on the current value signal (1) from the current detecting means 11. When it is determined that the arc discharge 6 is occurring, the switching device 3 is turned off to stop the current flow or to reduce the current flow. Can be detected immediately to prevent a vehicle fire or destruction of equipment due to the arc discharge 6.

The determining means 13 outputs the current value signal (1)
Is in the range of about 20% to 70% of the normal load current, it is determined that the current value signal (1) is abnormal and the arc discharge 6 is occurring, so that the current value signal (1) is reliable and easy. The arc discharge 6 can be detected.

The determining means 13 determines that the duration T of the abnormal current is equal to the switching time t1 of the switching device 3.
Since it is determined whether or not the above condition is satisfied, the arc discharge 6 is erroneously performed.
Can be prevented from being determined to have occurred.

Embodiment 2 In the first embodiment, the occurrence of the arc discharge 6 is detected by detecting the current value of the abnormal current at the time of the arc discharge 6. However, in the second embodiment, the abnormal voltage at the time of the arc discharge 6 is detected. The generation of the arc discharge 6 is detected by detecting the voltage value.

FIG. 4 shows such a second embodiment of the present invention.
1 is a block diagram showing a configuration of a discharge monitoring device according to the first embodiment. The discharge monitoring device according to the second embodiment includes a voltage monitoring device 3
0 and display means 20.

The voltage monitoring device 30 is a device that shuts down the current supplied to the load 5 by detecting an abnormal voltage at the time of the arc discharge 6 to prevent the arc discharge 6 from continuing. , Voltage detecting means 32 and determining means 33.

The voltage detecting means 3 in the voltage monitoring means 30
Reference numeral 2 denotes a circuit that constantly detects the voltage V1 or V2 of the harness on the upstream side (power supply 1 side) or downstream side (ground side) of the load 5 and sends the detected voltage value signal (4) to the determination unit 33. . The other components of the voltage monitoring means 30, that is, the power supply unit 31 and the determination means 33 are the same as those shown in FIG.
Since the configuration is substantially the same as that of the power supply unit 12 and the determination unit 13 shown in FIG.

The power supply 1, the fuse 2, the load control means 4 and the load 5 are the same as those of the power supply circuit shown in FIG.

Next, the operation will be described. The operation of the discharge monitoring device according to the second embodiment is substantially the same as the operation of the discharge monitoring device according to the first embodiment described with reference to FIG. The difference from the operation of the discharge monitoring device according to the first embodiment is that, in step ST4 of FIG. 2, in the first embodiment, the determination unit 13 determines that the current value signal (1) sent from the current detection unit 11 is normal. Although it is determined whether the voltage value signal (4) sent from the voltage detecting means 32 is normal or abnormal, it is determined whether the voltage value signal (4) is normal or abnormal.

Here, when the arc discharge 6 does not occur, no voltage drop occurs in the harness on the upstream side or the downstream side of the load 5 as shown in FIG. Both the voltage values V1 and V2 are 0V. Therefore, if the voltage value signal (4) sent from the voltage detecting means 32 is 0 V, the determining means 33 determines that the voltage values V1 and V2 on the upstream and downstream sides of the load 5 are normal and the arc discharge 6 It can be determined that no occurrence has occurred.

On the other hand, when the arc discharge 6 is generated, as shown in FIG.
Rises from the normal voltage value 0V to about 30% to 80% of the voltage value 42V of the power supply 1. Therefore, the judgment means 33
Means that the voltage value V1 on the upstream side of the load 5 or the voltage value V2 on the downstream side is about 30% or less of the voltage value (42V) of the power supply 1 by the voltage value signal (4) sent from the voltage detecting means 32.
When it is in the range of 80%, it can be determined that the voltage value V1 or V2 is abnormal and the arc discharge 6 is occurring. When the arc discharge 6 is completely terminated and the harness on the upstream or downstream side of the load 5 is opened, the voltage value V on the upstream or downstream side of the load 5 as shown in FIG.
1, V2 becomes the voltage value 42V of the power supply 1.

As described above, according to the second embodiment, the determining means 13 determines whether or not the arc discharge 6 has occurred based on the voltage value signal (4) from the voltage detecting means 32. When it is determined that the arc discharge 6 is occurring, the switching device 3 is turned off to stop the current flow or reduce the current flow. Generation of arc discharge 6 due to disconnection or short circuit of
Thus, it is possible to prevent a vehicle fire, destruction of equipment, and the like from occurring.

The current monitoring device 10 and the voltage monitoring means 30 in the first and second embodiments are configured so as to be incorporated in the fuse block, so that the fuse 2 and the current monitoring device 10 and the voltage monitoring means 30 are integrated. Between the current monitoring device 10 and the voltage monitoring means 30 can be eliminated even if the current monitoring device 10 and the voltage monitoring means 30 are added to the power supply circuit. No loss of quality.

Also, in the first embodiment, the current monitoring device 10 detects an abnormality in the electric current, so that the arc discharge 6
In the second embodiment, the arc discharge 6 is detected by detecting the voltage abnormality by the voltage monitoring means 30. However, these are combined, that is, the current abnormality is detected by the current monitoring device 10. Detecting and monitoring the voltage
By configuring to detect the voltage abnormality at 0 and to detect the arc discharge 6, it is possible to more reliably detect the arc discharge, and as a result, the destruction of the harness by the arc discharge 6 is further improved. Can be prevented beforehand.

[0050]

As described above, according to the present invention, the determination means determines whether or not arc discharge has occurred based on the current value signal or the voltage value signal from the current detection means or the voltage detection means. However, when it is determined that an arc discharge has occurred, the switching device is turned off to stop the flow of current.Therefore, the occurrence of the arc discharge due to the disconnection or short circuit of the harness is immediately detected, and the arc discharge is performed. Thus, it is possible to prevent a vehicle fire, destruction of equipment, and the like from occurring.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a discharge monitoring device according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation of the discharge monitoring device according to the first embodiment of the present invention.

FIG. 3 is a waveform chart showing current characteristics when an arc discharge occurs.

FIG. 4 is a block diagram illustrating a configuration of a discharge monitoring device according to a second embodiment of the present invention.

FIG. 5 is a waveform chart showing voltage characteristics when an arc discharge occurs.

FIG. 6 is a circuit diagram showing an example of a wiring structure of a general automotive power supply circuit.

FIG. 7 is a circuit diagram showing a state in which arc discharge has occurred due to disconnection or short circuit of the harness in the power supply circuit for a vehicle.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Power supply, 3 ... Switching device (switch means), 5 ... Load, 6 ... Arc discharge, 10 ... Current monitoring device, 11 ... Current detection means (Current / voltage detection means), 1
3, 33: determination means, 30: voltage monitoring device, 32: voltage detection means (current / voltage detection means).

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] October 23, 2000 (2000.10.
23)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

[0012]

In order to achieve the above object, a first discharge monitoring apparatus according to the present invention comprises a switch means for controlling the supply of power from a power supply to a load by performing a switching operation, Current detecting means for constantly detecting the supplied current value and outputting a current value signal of the detected current value; and determining whether the current value is abnormal based on the current value signal output from the current detecting means. Determining, when determining that there is an abnormality, determining that arc discharge has occurred, and determining means for controlling the switch means to stop the supply of power from the power supply to the load, and I do.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

Further, the second discharge monitoring device according to the present invention performs a switching operation to switch the power supply from the power supply to the load, and constantly detects a voltage value on the upstream or downstream side of the load. Then, based on the voltage value signal output from the voltage detection means and a voltage detection means for outputting a voltage value signal of the detected voltage value, it is determined whether the voltage value is abnormal, if it is abnormal When the determination is made, it is determined that an arc discharge has occurred, and a determination unit that controls the switch unit so as to stop the supply of power from the power supply to the load is provided.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

Further, the third discharge monitoring apparatus according to the present invention performs a switching operation to switch the power supply from the power supply to the load, and to constantly detect the value of the current supplied to the load. Current / voltage detecting means for constantly detecting the voltage value on the upstream side or the downstream side of the load and outputting a current value signal of the detected current value and a voltage value signal of the voltage value, and output from the current / voltage detecting means. Based on the current value signal and the voltage value signal, it is determined whether or not the current value and the voltage value are abnormal. And determination means for controlling the switch means so as to stop the supply of power to the power supply.

Claims (7)

[Claims] 1. A switching means for controlling the supply of power from a power supply to a load by performing a switching operation, and constantly detecting a current value supplied to the load, and outputting a current value signal of the detected current value. Based on the current value signal output from the current detecting means, determines whether or not the current value is abnormal, and when it is determined that the current value is abnormal, an arc discharge occurs. And a determination unit for controlling the switch unit to stop supplying power from the power supply to the load. 2. A switch means for controlling supply of power from a power supply to a load by performing a switching operation, and constantly detecting a voltage value on an upstream side or a downstream side of the load, and a voltage value of the detected voltage value A voltage detecting means for outputting a signal; and determining whether or not the voltage value is abnormal based on the voltage value signal output from the voltage detecting means. A discharge monitoring device comprising: a determination unit configured to determine that a power supply has occurred and control the switching unit so as to stop supplying power from the power supply to the load. 3. A switching means for controlling supply of power from a power supply to a load by performing a switching operation, and a current value supplied to the load is always detected, and
Current / voltage detecting means for constantly detecting a voltage value on the upstream side or downstream side of the load, and outputting a current value signal of the detected current value and a voltage value signal of the voltage value; Based on the current value signal and the voltage value signal output from the, it is determined whether the current value and the voltage value is abnormal, if it is determined to be abnormal, that arc discharge has occurred A discharge control device for controlling the switching means so as to stop the supply of power from the power supply to the load. 4. The apparatus according to claim 1, wherein said judging means judges that the current value is abnormal when said current value signal falls within a range of about 20% to 70% of a normal load current. Item 4. The discharge monitoring device according to item 1 or 3. 5. The apparatus according to claim 1, wherein said judging means judges that the voltage value is abnormal when the voltage value signal is within a range of about 30% to 80% of the normal power supply voltage. 2
Or the discharge monitoring device according to 3. 6. The determining means controls the switching means so as to stop the supply of power from the power supply to the load when the duration of the abnormal current or the abnormal voltage exceeds the switching time of the switching means. The discharge monitoring device according to any one of claims 1 to 5, wherein: 7. The discharge monitoring apparatus according to claim 1, wherein the determination means causes the display means to display a warning when it is determined that an arc discharge has occurred. apparatus.