JPS61214731A - Power source unit for automobile - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a power source device for an automobile that uses a separately excited generator and a battery to supply power to various electrical components, and in particular, to a power source device for electrical components. The present invention relates to a power supply system for an automobile that includes a battery for starting the vehicle and a battery for starting the vehicle.

[Background of the invention]

As the performance and functionality of automobiles improve, the types and number of electrical components continue to increase, and despite energy savings at the level of each electrical component, the demand for electricity within automobiles continues to increase.

By the way, electricity in a car is generally provided by a generator driven by the engine and a battery (generally a lead-acid battery is used) that is charged by the generator. ing.

Therefore, even if the power demand increases by 5Kt as mentioned above, it would be better to increase the capacity of the generator described above, although this is within the range allowed by the engine output and space.

- On the other hand, automobiles are generally used in a wide variety of ways; for example, in the current state of urban transportation, automobiles are forced to drive at low speeds for considerable periods of time when driving around town.

Generally, in order for a generator to generate its rated power, there is a lower limit to its driving rotational speed, and on the other hand, there is an upper limit to this driving rotational speed, which is determined by the model of the generator.

As a result, when a car is used at low speeds as mentioned above, even if the capacity of the generator is sufficient, the amount of power generated is insufficient, and over a long period of time, the battery can become over-discharged, so-called This will cause the battery to run out, making it difficult to use the car.

On the other hand, in order to avoid such troubles, the engine should provide sufficient rotational speed to drive the generator even when driving at low speeds, so that a sufficient amount of engine power can be obtained even when driving at low speeds. Otherwise, when the car moves from cruising speed to high speed, the generator will overspeed and exceed the above-mentioned upper limit.

Therefore, the conventional power supply device for an automobile has a problem in that the battery tends to run out of power when the automobile is traveling at low speed.

By the way, apart from this problem of battery draining while the car is running, there is also the problem of battery draining due to incorrect switch operation of electrical components when the car is parked. Showa 59-13
There is also a so-called two-battery power system, as disclosed in Notice No. 9887, in which a starting battery is provided in addition to the normal power battery, making it possible to start the engine even when the battery is dead. ing.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to obtain sufficient electric power from the generator even at a rotation speed lower than the rated drive rotation speed, so that the automobile can be driven at low speed. To provide a power supply device for an automobile that is free from the risk of battery failure even if the battery becomes exhausted.

[Summary of the invention]

To achieve this objective, the present invention provides two batch IJ-[
In the power supply system, a voltage higher than the rated output voltage of the generator is obtained from a series circuit of two batteries, and the excitation current is supplied to the field coil of the generator under this voltage. shall be.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The automotive power supply device according to the present invention will be described in detail below with reference to illustrated embodiments.

FIG. 1 shows an embodiment of the present invention. In the figure, 1.2 is a car-mounted 12V battery, which is connected in series with the engine starting motor 3. Starter switches 4 are connected in series.

5 is a charging generator and has an armature winding 51. and a rectifier 52 for converting it into DC output. It is composed of a field coil 53,
The output terminal of the rectifier 52 is connected to the first battery 1, and the field coil 53 is connected to the first and second patch! J-1,
2 are connected in series, and is connected to a terminal corresponding to the accounting voltage value.

6 is a charging control device that excites the field coil 53.
A power transistor 61 for controlling the power transistor 61 on and off; a control means 62 for controlling the output voltage of the generator to a constant level by controlling the power transistor 61 on and off; The control means (for example, a DCDC converter) 63 has an output terminal for charging the second battery 2 as an input.

Note that 64 is a flywheel diode.

Next, the operation of this embodiment will be explained.

First, when the key switch 7 is turned on, the transistor 61
is turned on and excitation t[ is supplied to the field coil 53. Next, when the starter switch 4 is turned on and the engine starting motor 3 is driven to start the engine, the charging generator 5 starts charging the first battery 1.

On the other hand, due to this, the limiting means 63 for charging the second battery 2 also operates and starts charging the second battery 2.

Note that in this embodiment, the first
The second battery 2 is configured to supply current only to the starting motor 3 and the field coil 53 of the charging generator.

Therefore, according to this embodiment, a voltage twice the rated voltage of this generator can be used as the excitation voltage of the charging generator 5, and therefore, even during low speed rotation, a sufficient voltage can be used. Opening operation is now possible, and even when the vehicle is driving at low speed, sufficient power can be supplied to the electrical load, eliminating the risk of the battery dying.

Also, according to this embodiment, in the unlikely event that general electricity is used.

Even if the load is used too much, only the #E1 battery will run out of battery.

Since the second battery 2 remains fully charged, it can be used in any situation! However, the engine can be started and powered, and it can provide sufficient reliability.゛Furthermore,
In this embodiment, power is normally supplied to the starting monitor 3 from the series circuit of the first and second batteries, so that the terminal voltage can be maintained above the rated value even during starting.
Since a large starting torque can be obtained, extremely good starting performance can be provided.

Next, another embodiment of the present invention is shown in FIG.

In FIG. 2, charging control device 8 includes limiting means 81. which controls the output of power transistor 61 to be constant. Excitation current limiting means 82 which connects this control means 81 to control the excitation current. It consists of a regulating means 63 having an output terminal for inputting the first battery voltage from the key switch 7 and charging the second battery 2 . Further, 9 is an input means for operating the excitation fa flow side means, and the rest is the same as the embodiment shown in FIG.

The operation of this embodiment will be explained below.The input means 9 gives the voltage control means 82 a temporary voltage when a load such as an on-vehicle cooler or a lamp is applied. Magnetic≠I,
Normally, the control means 82 acts to limit the excitation tffl of the field coil 53 by giving a signal to the voltage control means. .

According to this embodiment, the output of the generator is increased for a short period of time only when the general electrical load such as a cooler or rung increases, and normally the output is suppressed and the drive torque of the generator is low. 5, thereby improving the fuel efficiency of automobiles.

〔Effect of the invention〕

As explained above, according to the present invention, sufficient power generation capacity can be obtained even during low speed rotation, which eliminates the problems of the conventional technology (in addition, there is no fear that the engine will not be able to start due to a dead battery, and Accordingly, it is possible to easily provide a power supply device for a vehicle that can greatly improve the startability of an engine when the vehicle is in use.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing one embodiment of an automobile power supply device according to the present invention, and FIG. 2 is a circuit diagram showing another embodiment.

Claims (2)

[Claims] 1. A power supply battery that is directly charged by a separately excited generator driven by the automobile engine, and a starter that is charged from the separately excited generator via a step-up circuit and supplies power to the starter motor in series with the power supply battery. A power supply device for an automobile equipped with a power supply battery, wherein a voltage control circuit is provided for supplying excitation current to the field coil of the separately excited generator from a series circuit of the power supply battery and the starting battery,
A power supply device for an automobile, characterized in that it is configured to increase the amount of power generated when the engine rotates at low speed. 2. Claim 1: The automotive vehicle according to claim 1, wherein the voltage control circuit is configured such that the control voltage setting value is controlled depending on the on/off state of a load on the power supply battery. power supply.