JPH10311860A - Vehicular power supply unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular power supply unit which can prevent fuming and firing of a power line by precisely and easily detecting damage to the power line. SOLUTION: A constant voltage application means 53 which applies a constant voltage to an outer conductor 51c, a comparison means 54 which compares the voltage of the outer conductor 51c with a predetermined threshold VTH, and a failure determining means 56 which recognizes failures by monitoring the result of comparison by the comparison means 54 on a time axis are provided, and when the failure determining means 56 has recognized a failure, damage to a power line 51 is reported by a failure reporting means 55. Therefore, a vehicular power supply unit which can precisely and easily detect whether or not the power line 51 has been suffered with such damage as may cause fuming or firing can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for a vehicle, and more particularly to a power supply device for a vehicle designed to prevent smoke from being generated on the power supply line due to, for example, rare shortage of the power supply line. Applicable.

[0002]

2. Description of the Related Art Conventionally, in a vehicle, power generated by a power supply unit such as a battery and an alternator is generally supplied to each load via a wire harness composed of a plurality of electric wires. Among these wires, wires connected to loads that require a particularly large current (basic power supply wires) are connected to fusible links. In this case, it is possible to prevent damage to each load and smoke from electric wires due to excessive current generated at the time of dead short.

As shown in FIG. 5, this type of electric wire generally has a structure in which a large number of core wires 1a are protected by an insulating coating layer 1b of polyvinyl chloride or the like. That is, the trunk power supply line and the branch power supply line are usually bundled and protected by extrapolating a soft vinyl chloride tube or winding the tape.
a can be prevented from leaking.

[0004]

However, in a vehicle, the wire core 1a comes into contact with the body due to deterioration of the insulating coating layer 1b over time, contact with the edge of the vehicle, and wear.
There may be a so-called dead short or rare short state. In the former case, the fusible link is blown and a vehicle fire is prevented. However, if the latter state continues, the heat generated in the core wire 1a causes the insulation coating layer 1 to be blown before the fusible link is blown.
b may melt and burn, causing a vehicle fire.

Conventionally, as shown in FIG. 6, a conductive layer (hereinafter referred to as an external conductor) 10a and a conductive layer (hereinafter referred to as an outer conductor) 10a The electric wire 10 is formed by providing the insulating coating layer 10b, and the lamp 12 is attached to the outer conductor 10a.
There has been proposed a wire harness protection device configured to apply the voltage of the power supply 11 via a power supply (see Japanese Utility Model Publication No. 7-4).
No. 7747).

According to the wire harness protection device, when the insulating coating layer is damaged and the outer conductor 10a comes into contact with the body of the vehicle, a current flows through the lamp 12 and the lamp 12 is turned on, so that the user can use the wire harness. The damage can be notified promptly, and the smoke of the wire harness and the vehicle fire can be prevented.

However, in the conventional configuration as shown in FIG. 6, since the lamp 12 only blinks in response to the external conductor 10a coming into contact with the body, the user observes the degree of the lighting to see if the wire harness is damaged. The degree had to be judged, and there was a very complicated problem.

For example, if the lamp 12 is lit with a small amount of light or is lit only momentarily, the degree of damage does not extend to the insulating film 1b, so it is not necessary to replace the wire harness. No, lamp 12
If the light amount is large or the light is frequently turned on, there is a drawback that the user has to judge that the wire harness needs to be replaced.

The present invention has been made in view of the above points, and proposes a power supply device for a vehicle that can detect damage to a power supply line accurately and easily and avoid smoke and fire on the power supply line. It is assumed that.

[0010]

According to a first aspect of the present invention, there is provided a power supply device for a vehicle, comprising:
In the vehicle power supply device adapted to supply the power from the vehicle to each load 52 via the power line 51, the power line 5
Reference numeral 1 denotes an internal conductor 51a for electrically connecting the power supply unit 50 and each load 52, an internal insulator 51b provided so as to cover an outer periphery of the internal conductor 51a, and an internal insulator 5b.
External conductor 51c provided so as to cover the outer periphery of 1b
And an external insulator 51d provided so as to cover the outer periphery of the external conductor 51c, and the vehicle power supply device is electrically connected to the external conductor 51c and applies a constant voltage to the external conductor 51c. Constant voltage applying means 5 for applying
3, a comparing means 54 for comparing the voltage of the outer conductor 51c with a predetermined threshold VTH, and the comparing means 54
An abnormality notifying unit 55 for notifying that there is an abnormality in the power supply line 51 when a comparison result indicating that the voltage of 1c is smaller than the threshold value VTH is obtained.

In the above configuration, when the external insulator 51d is damaged and the body of the vehicle comes into contact with the external conductor 51c, the voltage of the external conductor 51c becomes lower than the constant voltage applied by the constant voltage applying means 53. It comes down. When the degree of contact between the outer conductor 51c and the body is increased and the voltage is greatly reduced, the voltage of the outer conductor 51c becomes smaller than the threshold value VTH. The indicated abnormal signal is sent to the abnormality notifying unit 55, and the user can know that the power supply line 51 is damaged by the abnormality notifying unit 55. As a result, the user can accurately and easily know the damage of the power supply line 51 without making a judgment by himself / herself.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the vehicle power supply apparatus according to the second aspect of the present invention monitors the result of comparison by the comparing means on a time axis to thereby provide the power supply line. Abnormality determination means 56 for determining whether or not there is an abnormality in the abnormality notification means 55.
Thus, when the determination result indicating that the power supply line 51 is abnormal is obtained, it is notified that the power supply line 51 is abnormal.

In the above configuration, for example, the comparing means 5
4. Only when the comparison result that the voltage of the outer conductor 51c is smaller than the threshold value VTH is obtained for a period longer than a certain period is obtained by the abnormality determination means 56, the abnormality indicating that the power supply line 51 is damaged. Signal is abnormal notification means 5
5 is sent. As a result, the body is securely inserted into the outer conductor 51c.
An abnormality determination is made only when it is attempted to reach 1a, and it can be more accurately detected that the power supply line 51 is damaged to a dangerous state.

Further, according to a third aspect of the present invention, there is provided a vehicle power supply apparatus for supplying power from a power supply unit to each load via a power line. The power supply line is provided so as to cover an outer conductor of the inner conductor, an inner conductor electrically connecting the power supply unit and each load, an inner insulator provided to cover an outer periphery of the inner conductor, and an outer insulator of the inner insulator. And an external insulator provided so as to cover the outer periphery of the external conductor, and the vehicle power supply device is configured to be electrically connected to the external conductor and apply a voltage to the external conductor. A voltage applying means, a comparing means for comparing a current value of the outer conductor with a predetermined threshold value, and an abnormality in the power supply line when a comparison result indicating that the current value of the outer conductor is larger than the threshold value is obtained by the comparing means. Know that there is So as to comprise a that abnormal notification means.

In the above configuration, if the external insulator is damaged and the body of the vehicle comes into contact with the external conductor, the external conductor changes from an electrically open state to a grounded state. It will flow. When the degree of contact between the outer conductor and the body increases, the current value becomes larger than the threshold value. Therefore, an abnormality signal indicating that the power line has been damaged is sent to the abnormality notification means by the comparison means, and the user is notified of the abnormality. It is possible to know that the power supply line is damaged by the means. As a result, the user can accurately and easily know the damage of the power supply line without making a judgment by himself / herself.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 20 denotes a vehicle power supply device according to the embodiment as a whole. The vehicle power supply device 20 supplies power from a power supply unit such as a battery 21 and an alternator 22 to a plurality of loads 27 via power lines 25 and 26.
28.

Further, fusible links 23 and 24 are provided between the power supply unit and the power supply lines 25 and 26, whereby the power supply lines 25 and 26 are damaged, and the loads 27 and 28 fail and the power supply lines 25 and 26 are damaged. When a large current flows through the fusible links 23 and 24, the fusible links 23 and 24 melt.
Smoke of the power supply lines 25 and 26 and damage of the loads 27 and 28 due to overcurrent can be prevented.

The power supply lines 25 and 26 provided between the fusible links 23 and 24 and the loads 27 and 28 shown by dotted lines in FIG. 2 are connected to the power supply section and each load 27 as shown in FIG. , 28, an inner insulator 41 provided to cover the outer periphery of the inner conductor 40, and an outer conductor provided to cover the outer periphery of the inner insulator 41. And an external insulator 43 provided so as to cover the outer periphery of the external conductor.

The constant voltage formed by the constant voltage circuit 29 shown in FIG. 2 is applied to the outer conductor 42. As is clear from the figure, the constant voltage circuit 29 includes a zener diode 30 and resistors R1 and R2, generates a constant voltage from the power supply voltage VCC, and applies this to the external conductor. The constant voltage applied to the outer conductor 42 is selected to be low enough that the insulating film 43 does not emit smoke even when the outer conductor 42 comes into contact with the body.

Further, the external conductor 42 is connected to the comparison circuit 31, and the comparison circuit 31 compares the voltage of the external conductor 42 with a predetermined threshold. Specifically, the comparison circuit 31 inputs the voltage of the external conductor 42 to one input terminal of the comparator 32, and supplies the power supply voltage to the other input terminals of the resistors R3 and R3.
By inputting the reference voltage obtained by dividing the voltage in step 4, the voltage of the external conductor 42 is compared with the reference voltage, and a logical value corresponding to the comparison result is output.

The output logic value from the comparator 32 is sent to the judgment section 33. The determination unit 33 has a microprocessor configuration, and determines whether there is any abnormality in the power supply lines 25 and 26 by monitoring the output logical value from the comparator 32 on a time axis. Specifically, the determination unit 33 determines that the output of the comparator 32 is abnormal when a logical value indicating that the voltage value of the external conductor 42 is lower than the reference voltage value is continuously output for a certain period or more. Then, an abnormal signal is sent to a warning lamp 35 provided in the meter 34 to turn on the warning lamp 35.

Here, the determination process of the determination unit 33 will be described with reference to FIG. That is, when the insulating coating 43 of the power supply lines 25 and 26 is worn due to contact with the body of the vehicle or the like, the outer conductor 42 comes into contact with the body as shown by a dashed line in FIG. Is lower than the constant voltage value in accordance with the contact time and the degree of contact with the body (FIG. 4A).

The comparator 32 operates from the time point t1 to the time point t2.
The positive logic signal is output only when the voltage value VA of the outer conductor 42 becomes smaller than the threshold voltage VTH, as in the period from the time point t4 to the time point t5 (see FIG. 4).
(B)).

The determination unit 33 ignores the output of the positive logic from the comparator 32 for a short time, and outputs a positive logic error signal only when the output period of the positive logic is longer than a certain time. Output. Specifically, at time t1
Since the period from the time t2 to the time t2 is very short, this is not judged to be abnormal.
The power supply lines 25 and 26 are the first
It is determined that it is worthwhile to determine that there has been damage, and an abnormal signal of positive logic is output (FIG. 4C).

In the above configuration, when the insulating coating layer 43 is damaged and the body of the vehicle comes into contact with the outer conductor 42, the voltage of the outer conductor 42 becomes lower than the constant voltage applied by the constant voltage circuit 32. Become like When the degree of contact between the outer conductor 42 and the body increases and the voltage decreases, the voltage of the outer conductor 42 becomes smaller than the threshold value, so that the comparator 32 outputs a positive logic signal.

When the positive logic output from the comparator 32 is obtained for a period longer than a certain period, the judging section 33 sends an abnormal signal to the warning lamp 35 to turn on the warning lamp 35. As a result, the body is securely inserted into the outer conductor 42, and the next time an attempt is made to reach the inner conductor 40, an abnormality is determined only for the first time.
It is possible to accurately detect that 5, 26 has been damaged to a dangerous state, and notify the user of this.

Thus, the user can accurately and easily know the damage of the power supply line 51 without making a judgment by himself / herself.

According to the above configuration, the constant voltage circuit 29 for applying a constant voltage to the external conductor 42, the comparison circuit 31 for comparing the voltage VA of the external conductor 42 with the predetermined threshold VTH, and the comparison result of the comparison circuit 31 Is provided on the time axis to determine the abnormality, and when the determination unit 33 obtains the abnormality determination result, the warning lamp 35 is turned on. It is possible to realize the vehicle power supply device 20 that can accurately and easily detect whether or not the vehicle is damaged so as to cause smoke or fire.

Since a stable voltage is applied to the outer conductor 42 from the constant voltage circuit 29, the inner conductor 4
It is possible to prevent the emission of noise from 0 to the outside and the entry of noise from the outside to the internal conductor 40.

Further, since the stable voltage generated by the constant voltage circuit 29 is applied to the external conductor 42, for example, the voltage of the battery 21 is directly applied to the external conductor 42.
, The comparator 32 can perform a comparison process that is not affected by the voltage change by the alternator 22 or the like.

In the above embodiment, the judgment unit 3
3 is provided, and the abnormality determination is performed only when the comparison result that the voltage VA of the outer conductor 42 is smaller than the threshold value VTH is obtained by the comparator 32 for a period longer than a certain period is described. However, the present invention is not limited to this.
Alternatively, the warning lamp 35 may be turned on directly based on the logical value from 2. Even in this case, since the threshold value is determined by the comparator 32, abnormality detection is much more accurate and easy than in the conventional case where the lamp is lit according to the current flowing through the external conductor. It can be carried out.

In the above embodiment, the constant voltage circuit 29 for applying a constant voltage to the external conductor 42 and the comparison circuit 3 for comparing the voltage VA of the external conductor 42 with a predetermined threshold value VTH.
1 and a determination unit 33 for monitoring the comparison result of the comparison circuit 31 on the time axis and performing abnormality determination is provided, and the warning lamp 35 is turned on when the determination unit 33 obtains an abnormality determination result. Although the case has been described, the present invention is not limited to this, and a constant voltage applying unit that is electrically connected to the external conductor 42 and applies a voltage to the external conductor 42 is compared with a current value of the external conductor 42 and a predetermined threshold. A comparison means and an abnormality notification means for notifying that there is an abnormality in the power supply lines 25 and 26 when a comparison result indicating that the current value of the outer conductor 42 is larger than the threshold value is obtained by the comparison means. In this case, substantially the same effects as those of the above embodiment can be obtained.

[0034]

As described above, according to the present invention, it is determined that the power supply line is abnormal only when the body is securely inserted into the outer conductor and then tries to reach the inner conductor. By being able to be notified, it becomes possible to realize a vehicle power supply device capable of accurately and easily detecting damage to the power supply line and avoiding smoke or fire on the power supply line.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a vehicle power supply device according to the present invention.

FIG. 2 is a connection diagram showing an embodiment of a vehicle power supply device according to the present invention.

FIG. 3 is a schematic sectional view showing a configuration of a power supply line.

FIG. 4 is a timing chart for explaining an abnormality determination process;

FIG. 5 is a perspective view showing a configuration of a general power supply line.

FIG. 6 is a schematic connection diagram illustrating a configuration of a conventional wire harness protection device.

[Explanation of symbols]

50 (21, 22) Power supply unit (battery, alternator) 51 (25, 26) Power line 51a (40) Internal conductor 51b (41) Internal insulator 51c (42) External conductor 51d (43) External insulator 52 (27) , 28) Load 53 (29) Constant voltage application means (constant voltage circuit) 54 (31) Comparison means (comparison circuit) 55 (35) Abnormality notification means (warning lamp) 56 (33) Abnormality determination means (determination unit)

Claims (3)

[Claims] 1. A vehicle power supply device configured to supply power from a power supply unit to each load via a power supply line, wherein the power supply line electrically connects the power supply unit and the loads. An inner conductor, an inner insulator provided to cover the outer periphery of the inner conductor, an outer conductor provided to cover the outer periphery of the inner insulator, and an outer conductor provided to cover the outer periphery of the outer conductor. The vehicle power supply device is electrically connected to the external conductor and applies a constant voltage to the external conductor; and Comparing means for comparing a voltage with a predetermined threshold value; and an abnormality notifying that there is an abnormality in the power supply line when a comparison result indicating that the voltage of the outer conductor is smaller than the threshold value is obtained by the comparing means. Notice A power supply device for a vehicle, comprising: an informing means. 2. The vehicle power supply device further comprises abnormality determination means for determining whether or not there is an abnormality in the power supply line by monitoring a comparison result by the comparison means on a time axis. 2. The vehicle power supply according to claim 1, wherein the notifying unit notifies the abnormality of the power supply line when the abnormality determination unit obtains a determination result indicating that the power supply line is abnormal. Feeding device. 3. A vehicle power supply device configured to supply power from a power supply unit to each load via a power supply line, wherein the power supply line electrically connects the power supply unit and each load. An inner conductor, an inner insulator provided to cover the outer periphery of the inner conductor, an outer conductor provided to cover the outer periphery of the inner insulator, and an outer conductor provided to cover the outer periphery of the outer conductor. The vehicle power supply device is electrically connected to the external conductor, and applies a voltage to the external conductor; anda current value of the external conductor. Comparing means for comparing with a predetermined threshold value; and, when the comparing means obtains a comparison result indicating that the current value of the outer conductor is larger than the threshold value, an abnormality notification notifying that there is an abnormality in the power supply line. hand Preparative vehicle power supply apparatus characterized by comprising a.