JPH10271670A - Power supply for vehicles - Google Patents

Abstract

(57) [Problem] To provide a vehicle power supply capable of reliably driving an important vehicle-mounted load. SOLUTION: When a load driving voltage from a storage battery 2 is reduced due to discharging or the like, a rectifier 4 is turned off and a rectifier 5 is turned on, and a desired load driving voltage is supplied from a generator 3 via a connection point 6. It is supplied to the vehicle-mounted load circuit 10. When the load drive voltage from the generator 3 decreases due to discharge or the like, the rectifier 5 is turned off and the rectifier 4 is turned on, and the desired load drive voltage from the storage battery 2 is applied to the vehicle load via the connection point 6. It is supplied to the circuit 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle power supply capable of reliably driving an important vehicle load.

[0002]

2. Description of the Related Art A conventional vehicle power supply comprises a battery, an alternator (alternating current generator), a relay box, a joint box, a vehicle-mounted load circuit, and the like. Such a vehicle power supply supplies power to the on-vehicle load drive circuit from one battery when the engine is stopped and the engine is stopped. Therefore, when the supply voltage of the battery is reduced due to the discharge due to the dark current or the self-discharge of the battery when the engine is stopped, a sufficient drive voltage cannot be supplied to the on-vehicle load drive circuit. By the way, since a large number of electronic control circuits for controlling the running are incorporated in the on-vehicle load drive circuit, the engine may not even be able to be started unless a sufficient drive voltage is supplied.

In order to solve such a problem, a vehicle power supply having two batteries, a starting battery and a load battery, has been proposed. In this vehicle power supply, the starting battery is connected only to the starter and the ignition circuit, and is not connected to other load circuits. Further, the load battery is connected to all the vehicle-mounted load circuits except the starter and the ignition circuit.

[0004]

However, due to the space in the vehicle, it is necessary to incorporate a vehicle power supply in the same space as one battery conventionally used. Here, the capacity of the battery is largely determined by its size. Therefore, in a vehicle power supply including two batteries, the starting battery and the load battery, the capacity of each battery is about half of the capacity of one conventional battery. As a result, the life of the battery is reduced to half that of the conventional battery, and the battery is susceptible to the discharge caused by dark current and the self-discharge of the battery itself. Also, in the case of the starting battery, when the engine is repeatedly started, the supply voltage may decrease and the battery may rise.

In the conventional vehicle power supply described above, when the supply voltage of the starting battery decreases, the ignition circuit cannot be driven. For example, even if the load battery is normal, the engine cannot be started.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the prior art, and has as its object to provide a vehicle power supply capable of reliably driving an important vehicle-mounted load.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art and to achieve the above-mentioned object, a vehicle power supply according to the present invention drives an AC power generation means and a vehicle-mounted load. A first power supply and a second power supply for supplying a load driving power to be supplied, a first power supply line for supplying the load driving power from the first power supply to a vehicle-mounted load, and a load from the second power supply A second power supply line for supplying drive power to the vehicle-mounted load via a connection point with the first power supply line, and a forward direction from the first power supply toward the connection point, A first rectifier provided on the first power supply line; and a second rectifier provided on the second power supply line so as to be forward from the second power supply toward the connection point. A rectifier.

In the vehicle power supply according to the present invention, for example, when the engine is stopped, the first power is generated by the discharge due to the dark current or the self-discharge.
When the load drive voltage supplied from the power supply of
Rectifier becomes non-conductive, the second rectifier becomes conductive, and a desired load driving voltage supplied from the second power supply is generated at the connection point. Thus, even when the load drive voltage from the first power supply decreases, a desired load drive voltage can be supplied to the on-vehicle load. On the other hand, for example, when the load drive voltage supplied from the second power supply decreases due to discharge or self-discharge due to dark current when the engine is stopped, the second rectifier becomes non-conductive, the first rectifier becomes conductive, A desired load driving voltage supplied from the first power supply is generated at the connection point. Thus, even when the load drive voltage from the second power supply decreases, a desired load drive voltage can be supplied to the on-vehicle load.

In the vehicle power supply according to the present invention, for example, the first power supply is a starting battery, and the second power supply is a load battery.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle power supply according to an embodiment of the present invention will be described below. First Embodiment FIG. 1 is a configuration diagram of a vehicle power supply 11 according to the present embodiment. As shown in FIG. 1, a vehicle power supply 1 includes a storage battery 2,
A storage battery 13, rectifiers 4 and 5 and an alternator 9 are provided. The storage battery 2 is, for example, a lead storage battery and has a positive electrode 2a
Supplies a load driving voltage of about 12V or 24V. The storage battery 13 is, for example, a lead storage battery, and has a positive electrode 13a.
Supplies a load driving voltage of about 12V or 24V. Here, the rectifiers 4 and 5 are, for example, diodes having a rectifying function.

In the vehicle power supply 11, the positive electrode 2 of the storage battery 2
a is connected to the connection point 6 via the rectifier 4.
The rectifier 4 is connected such that the direction from the positive electrode 2a toward the connection point 16 is the forward direction. The storage battery 13
Is connected to a connection point 16 via the rectifier 5. The rectifier 5 is connected from the positive electrode 13a to the connection point 1
They are connected so that the direction toward 6 is the forward direction.
The connection point 16 is connected to the on-vehicle load circuit 10, and the connection point 16
Is supplied to the vehicle-mounted load circuit 10.

The on-vehicle load circuit 10 is a circuit for driving important on-vehicle loads related to vehicle running and safety, such as an engine control drive unit, an airbag operation drive unit, a suspension control drive unit, and an ABS drive unit. The alternator 9 is an AC generator that rotates an excited magnetic pole to generate a three-phase AC current in a fixed coil, rectifies the AC current with a rectifier, and extracts the DC current.

The function of the vehicle power supply 11 will be described below. In the vehicle power supply 11, the rectifiers 4 and 5 cause the voltage at the connection point 16 to be the higher one of the load driving voltages supplied from the + electrode 2a and the + electrode 13a, respectively. Specifically, for example, when the load driving voltage supplied from the + electrode 2a is higher than the load driving voltage supplied from the + electrode 13a, the rectifier 4 is turned on and the rectifier 5 is turned off. , And the connection point 16 becomes the load driving voltage supplied from the + electrode 2a. On the other hand, for example, when the load driving voltage supplied from the + electrode 13a is higher than the load driving voltage supplied from the + electrode 2a, the rectifier 5 becomes conductive and the rectifier 4
Are turned off, and the connection point 16 is at the load drive voltage supplied from the + electrode 13a.

Therefore, in the vehicle power supply 11, for example, when the engine is stopped, discharge by dark current or self-discharge causes
When the load driving voltage supplied from the storage battery 2 decreases, the rectifier 4 becomes non-conductive and the rectifier 5 becomes conductive, and a desired load driving voltage supplied from the storage battery 13 is generated at the connection point 16. As a result, even when the load drive voltage from the storage battery 2 decreases, a desired load drive voltage can be supplied to the on-vehicle load circuit 10. On the other hand, for example, when the load drive voltage supplied from the storage battery 13 is reduced due to dark current discharge or self-discharge when the engine is stopped, the rectifier 5 is turned off and the rectifier 4 is turned on. 2 results in the desired load drive voltage.
As a result, even when the load drive voltage from the storage battery 13 decreases, a desired load drive voltage can be supplied to the on-vehicle load circuit 10.

As described above, according to the vehicle power supply 11, even when one of the load driving voltages supplied from the storage battery 2 and the storage battery 13 is reduced by the discharge due to the dark current or the self-discharge, the desired one is obtained from the other. The load drive voltage can be supplied to the on-vehicle load circuit 10, and an important on-vehicle load can be reliably operated.

In the above-described power supply 11 for a vehicle, lead-acid batteries have been exemplified as the storage batteries 2 and 13.
A hydrogen battery, a lithium ion battery, or the like may be used.

Second Embodiment FIG. 2 is a configuration diagram of a vehicle power supply 1 according to this embodiment. As shown in FIG. 2, the vehicle power supply 1 includes a storage battery 2, a generator 3, rectifiers 4 and 5, and an alternator 9. The storage battery 2 is, for example, a lead storage battery, and supplies a load driving voltage of about 12 V or 24 V from the + electrode 2 a.
The generator 3 is, for example, a thermoelectric generator. A load driving voltage of about 12 V or 24 V obtained by converting thermal energy into electric energy (DC voltage) using a temperature difference between inside and outside of the vehicle is supplied from the + electrode 3 a. Supply.

In the vehicle power supply 1, the positive electrode 2a of the storage battery 2
Are connected to a connection point 6 via a rectifier 4. The rectifier 4 is connected such that the direction from the positive electrode 2a toward the connection point 6 is the forward direction.

The positive electrode 3a of the generator 3 is connected to the rectifier 5
Is connected to the connection point 6 via Rectifier 4 is +
The connection is made such that the direction from the electrode 3a toward the connection point 6 is the forward direction. The connection point 6 is connected to the on-vehicle load circuit 10, and the load driving voltage generated at the connection point 6 is applied to the on-vehicle load circuit 1.
0 is supplied.

Hereinafter, the function of the vehicle power supply 1 will be described. In the vehicle power supply 1, the rectifiers 4 and 5 cause the voltage at the connection point 6 to be the higher one of the load driving voltages supplied from the + electrode 2a and the + electrode 3a. Specifically, for example, when the load driving voltage supplied from the + electrode 2a is higher than the load driving voltage supplied from the + electrode 3a, the rectifier 4 becomes conductive,
The rectifier 5 becomes non-conductive, and the connection point 6 becomes the load driving voltage supplied from the + electrode 2a. On the other hand, for example, when the load driving voltage supplied from the + electrode 3a is higher than the load driving voltage supplied from the + electrode 2a, the rectifier 5 is turned on and the rectifier 4 is turned off. And the connection point 6 becomes the load drive voltage supplied from the + electrode 3a.

Therefore, in the vehicle power supply 1, when the load drive voltage supplied from the storage battery 2 is reduced due to, for example, discharge due to dark current or self-discharge when the engine is stopped, the rectifier 4 is turned off and the rectifier 5 is turned on. In this state, a desired load driving voltage supplied from the generator 3 is generated at the connection point 6. As a result, even when the load drive voltage from the storage battery 2 decreases, the desired load drive
0 can be supplied.

On the other hand, for example, when the load drive voltage supplied from the generator 3 decreases due to discharge due to dark current or self-discharge when the engine is stopped, the rectifier 5 becomes non-conductive, the rectifier 4 becomes conductive, and the connection point In 6, a desired load driving voltage supplied from the storage battery 2 is generated. by this,
Even when the load drive voltage from the generator 3 drops, a desired load drive voltage can be supplied to the on-vehicle load circuit 10.

As described above, according to the vehicle power supply 1, even if one of the load driving voltages supplied from the storage battery 2 and the generator 3 is reduced by the discharge due to the dark current or the self-discharge, the desired voltage is obtained from the other. Can be supplied to the on-vehicle load circuit 10, and an important on-vehicle load can be reliably operated.

Third Embodiment FIG. 3 is a configuration diagram of a vehicle power supply 21 according to this embodiment. As shown in FIG. 3, the vehicle power supply 21 includes a storage battery 2, a button-type battery 23, rectifiers 4 and 5, and an alternator 9. In the vehicle power supply 21 shown in FIG. 3, the storage battery 2, the rectifier 4,
5. The vehicle-mounted load circuit 10 and the alternator 9 are the same as those described in the first embodiment. That is,
The vehicle power supply 21 has a configuration using a button-type battery 23 instead of the generator 3 shown in FIG.

As the button-type battery 23, for example, a button-type air-zinc battery is used.
A 2V or 24V load drive voltage is supplied.

In the vehicle power supply 1, the positive electrode 2a of the storage battery 2
Is connected to the connection point 26 via the rectifier 4.
The rectifier 4 is connected such that the direction from the positive electrode 2a toward the connection point 26 is the forward direction. The + electrode 23 a of the button type battery 23 is connected to the connection point 2 via the rectifier 5.
6 is connected. The rectifier 4 is connected such that the direction from the positive electrode 23a toward the connection point 6 is the forward direction. The connection point 26 is connected to the vehicle-mounted load circuit 10, and the load driving voltage generated at the connection point 26 is supplied to the vehicle-mounted load circuit 10.

The function of the vehicle power supply 21 will be described below. In the vehicle power supply 21, the rectifiers 4 and 5 cause the voltage at the connection point 26 to be the higher one of the load driving voltages supplied from the + electrode 2a and the + electrode 23a. Specifically, for example, when the load driving voltage supplied from the + electrode 2a is higher than the load driving voltage supplied from the + electrode 23a, the rectifier 4 is turned on and the rectifier 5 is turned off. , And the connection point 26 becomes the load driving voltage supplied from the + electrode 2a. On the other hand, for example, when the load driving voltage supplied from the + electrode 23a is higher than the load driving voltage supplied from the + electrode 2a, the rectifier 5 becomes conductive and the rectifier 4
Are turned off, and the connection point 26 is at the load driving voltage supplied from the + electrode 23a.

Therefore, in the vehicle power supply 21, for example, when the engine is stopped, discharge by dark current or self-discharge causes
When the load driving voltage supplied from the storage battery 2 decreases, the rectifier 4 becomes non-conductive and the rectifier 5 becomes conductive, and a desired load driving voltage supplied from the button type battery 23 is generated at the connection point 26. As a result, even when the load drive voltage from the storage battery 2 decreases, a desired load drive voltage can be supplied to the on-vehicle load circuit 10. On the other hand, for example, when the engine is stopped, if the load drive voltage supplied from the button-type battery 23 decreases due to discharge due to dark current or self-discharge,
The rectifier 5 is turned off and the rectifier 4 is turned on, and a desired load driving voltage supplied from the storage battery 2 is generated at the connection point 6. As a result, even when the load drive voltage from the button-type battery 23 decreases, a desired load drive voltage can be supplied to the on-vehicle load circuit 10.

As described above, according to the vehicle power supply 21, even when one of the load driving voltages supplied from the storage battery 2 and the button-type battery 23 is reduced by the discharge due to the dark current or the self-discharge, the load drive voltage is not changed from the other. A desired load drive voltage can be supplied to the on-vehicle load circuit 10, and an important on-vehicle load can be reliably operated.

In the above-described vehicle power supply, a button battery is exemplified, but a primary battery such as a dry battery, or an energy conversion battery such as a solar battery or a fuel cell may be used.

Fourth Embodiment FIG. 4 is a configuration diagram of a vehicle power supply 31 according to the present embodiment. As shown in FIG. 4, the vehicle power supply 31 includes a starting battery 32, a load battery 33, rectifiers 4 and 5, and the alternator 9. Starting battery 3
2 is connected to the starter 50. In the vehicle power supply 31 shown in FIG. 4, the rectifiers 4, 5, the on-vehicle load circuit 10, and the alternator 9 denoted by the same reference numerals as those in FIG. 2 are the same as those described in the first embodiment. That is, the vehicle power supply 21 has a configuration in which a starting battery 32 is provided instead of the storage battery 2 shown in FIG. 2 and a load battery 33 is provided instead of the generator 3.

The starting battery 32 is, for example, a lead storage battery, and supplies a load driving voltage of about 12 V or 24 V from the + electrode 32a. The load battery 33 is also a lead storage battery, for example, about 12 V or 2 V from the + electrode 33a.
A load driving voltage of 4 V is supplied.

In the vehicle power supply 31, the starting battery 3
The second positive electrode 32a is connected to the connection point 36 via the rectifier 4. The rectifier 4 is connected such that the direction from the positive electrode 32a toward the connection point 36 is the forward direction. The positive electrode 33a of the load battery 33 is connected to the connection point 36 via the rectifier 5. The rectifier 4 is connected such that the direction from the + electrode 33a toward the connection point 36 is the forward direction. The connection point 36 is connected to the on-vehicle load circuit 10, and the load driving voltage generated at the connection point 36 is supplied to the on-vehicle load circuit 10.

The function of the vehicle power supply 31 will be described below. In the vehicle power supply 31, the rectifiers 4 and 5 cause the voltage at the connection point 36 to be the higher one of the load drive voltages supplied from the + electrode 32a and the + electrode 33a, respectively. Specifically, for example, when the load driving voltage supplied from the + electrode 32a is higher than the load driving voltage supplied from the + electrode 33a, the rectifier 4 is turned on and the rectifier 5 is turned off. And connection point 3
Reference numeral 6 denotes a load driving voltage supplied from the + electrode 32a.
On the other hand, for example, when the load drive voltage supplied from the + electrode 33a is higher than the load drive voltage supplied from the + electrode 32a, the rectifier 5 becomes conductive,
The rectifier 4 is turned off, and the connection point 36 is connected to the positive electrode 33.
It becomes the load drive voltage supplied from a.

Accordingly, in the vehicle power supply 21, for example, when the engine is stopped, discharge by dark current or self-discharge causes
When the load driving voltage supplied from the starting battery 32 decreases, the rectifier 4 becomes non-conductive and the rectifier 5 becomes conductive, and a desired load driving voltage supplied from the load battery 33 is generated at the connection point 36. As a result, even when the load drive voltage from the starting battery 32 decreases, a desired load drive voltage can be supplied to the on-vehicle load circuit 10. On the other hand, when the load drive voltage supplied from the load battery 33 is reduced due to, for example, discharge due to dark current or self-discharge when the engine is stopped, the rectifier 5 is turned off, the rectifier 4 is turned on, and the connection point 36 Generates a desired load driving voltage supplied from the starting battery 32. Thus, even when the load driving voltage from the load battery 33 decreases, a desired load driving voltage can be supplied to the on-vehicle load circuit 10.

As described above, according to the vehicle power supply 31, the starting battery 32 and the load battery 3
Even if one of the load driving voltages supplied from 3 drops due to dark current discharge or self-discharge, a desired load driving voltage can be supplied from the other to the on-vehicle load circuit 10 and the important on-vehicle load is reliably operated. be able to.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the connection points 6, 26,
Although the case where one vehicle-mounted load circuit 10 is connected to 36 is illustrated, a plurality of vehicle-mounted load circuits may be connected to the connection points 6, 26, and 36. Further, in the above-described embodiment, the case where power is supplied from two power supplies except the alternator to the on-vehicle load circuit has been described.
Power may be supplied to the vehicle-mounted load circuit from more than two power sources.

[0038]

As described above, according to the power supply for a vehicle of the present invention, even if one of the first power supply and the second power supply is reduced by discharge due to dark current or self-discharge, the other power supply is used. Thus, a desired load driving voltage can be supplied to the on-vehicle load, and the important on-vehicle load can be reliably operated.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a vehicle power supply according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a vehicle power supply according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a vehicle power supply according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a vehicle power supply according to a fourth embodiment of the present invention.

[Explanation of symbols]

1, 11, 21, 31 ... power supply for vehicles, 2, 3 ... storage battery,
3 ... Generator, 4,5 ... Rectifier, 6,16,26,36 ...
Connection point, 9: Alternator, 10: In-vehicle load circuit 10,
23 ... button type battery, 32 ... starting battery, 33 ...
Battery for load

Claims (2)

[Claims] 1. An AC power generating means, a first power supply and a second power supply for supplying load driving power for driving a vehicle-mounted load, and a load driving power from the first power supply is supplied to a vehicle-mounted load. A first power supply line, a second power supply line that supplies load drive power from the second power supply to the vehicle-mounted load via a connection point with the first power supply line, A first rectifier provided on the first power supply line so as to be forward from the power supply toward the connection point; and a forward rectifier provided from the second power supply toward the connection point. And a second rectifier provided on the second power supply line. 2. The vehicle power supply according to claim 1, wherein the first power supply is a starting battery, and the second power supply is a load battery.