JPH06242194A - Presuming device for remaining capacity of battery - Google Patents

Abstract

PURPOSE:To presume the remaining capacity of a battery even during the running of a vehicle. CONSTITUTION:After the controller 4 of a battery remaining. capacity presuming device separates the ignition terminal of an alternater 1 from a 12-volt power source line to stop power generation executed by the alternater 1 in a state where electric load is driven and an engine is rotated, the presuming device drives the electric load by single-handed battery 2, and presumes the remaining capacity of the battery 2 on the lowering rate of a battery terminal voltage in driving the electric load by the battery 2, and starts the alternater 1 after presuming the remaining capacity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery remaining capacity estimation device mounted on a vehicle, and more particularly to a battery remaining capacity estimation device suitable for confirming the remaining capacity of a battery even while the vehicle is operating.

[0002]

2. Description of the Related Art Conventionally, as a method for confirming the state of charge of an on-vehicle battery (remaining capacity of battery power), for example, as shown in FIG. 4, a hydrometer 52 is inserted from an electrolyte injection port 51 of an on-vehicle battery 50. There is a method in which the specific gravity of the electrolytic solution is measured, and when the measured specific gravity of the electrolytic solution is large, it is determined that the battery residual capacity is large, and when the measured specific gravity of the electrolytic solution is small, it is determined that the battery residual capacity is small.

Further, as shown in FIG. 5, for example, a resistor R is connected in series to the vehicle-mounted battery 53 in a circuit composed of the vehicle-mounted battery 53, the alternator 54, the load 55, etc.
When the output voltage of the alternator 54 calculated from the engine speed is Vo, the terminal voltage VR of the resistor R (= R × i
There is also a method of confirming the polarity of 3) and determining that the battery is being charged when VR> 0 and determining that the battery is discharging when VR <0.

[0004]

However, among the above-mentioned conventional battery state confirmation methods, in the case of the method for determining the battery residual capacity based on the specific gravity of the electrolytic solution of the vehicle-mounted battery, the electrolytic solution injection of the battery is performed at the time of measuring the specific gravity. Since it is necessary to remove the inlet caps one by one, there is a problem in that the measurement work is complicated and troublesome. Further, in the case of the method of determining the battery state based on the polarity of the terminal voltage of the resistor connected in series to the vehicle-mounted battery, there is a problem that battery power is always consumed by the series resistor.

On the other hand, in a vehicle equipped with an economy running system (a system that stops the engine when the vehicle is idling when the vehicle stops at an intersection or the like and restarts the engine when the vehicle starts), stops the engine when idling. In this case, the battery may rise when the electric load is driving, so it is necessary to check the battery charge status (remaining capacity), but the conventional system has a function to check the battery charge status. There was a problem not to do.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a battery remaining capacity estimating apparatus which improves the above-mentioned disadvantages of the prior art and enables confirmation of the remaining capacity of the battery even during vehicle operation.

[0007]

According to the present invention, there is provided a battery remaining capacity estimation for an engine driven vehicle equipped with a generator connected to a battery and an electric load for charging the battery and supplying electric power to the electric load. A device for causing the battery to stop power generation by the generator at a predetermined time while the engine is being driven; a function for supplying power from the battery to the electric load when the generator stops generating power; The function of monitoring the fluctuation of the terminal voltage of the battery at the time of supplying electric power to the electric load and estimating the remaining capacity of the battery based on the fluctuation of the terminal voltage, and starting the generator after the estimation of the remaining capacity is completed. It has a configuration in which a controller having a function of making it connected is connected. This is intended to achieve the above-mentioned object.

[0008]

According to the present invention, when the remaining capacity of the battery is estimated, for example, when the vehicle is stopped at an intersection or the like because of waiting for a signal and is in an idling state, the generator that is generating power as the engine is driven. Is stopped and electric power is supplied from the battery to the electric load, whereby the electric load is driven by the battery alone. Then, when the electric load is driven by the battery, the fluctuation of the terminal voltage of the battery is monitored, and the remaining capacity of the battery is estimated based on the fluctuation of the battery terminal voltage. As a result, the remaining capacity of the battery can be confirmed even while the vehicle is in operation, without visually observing the battery electrolyte solution or measuring the specific gravity of the battery electrolyte solution as in the conventional case.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment to which the battery remaining capacity estimating device of the present invention is applied will be described below with reference to the drawings.

The electrical configuration of the main part of a vehicle equipped with the battery remaining capacity estimating device of this embodiment will be described with reference to FIG. 1. The battery terminal B of the alternator 1 for supplying electric power to the electric load and charging the battery is as follows. The positive terminal of the battery 2 (for example, the capacity is 12V) and the movable contact and the fixed contact of the ignition switch 3 are connected to the movable contact, respectively, and the ignition terminal IG of the alternator 1 (for operating the alternator exciting coil) The terminal) and the terminal L are connected to a battery charge state estimation controller 4 (hereinafter, abbreviated as a controller) that constitutes a main part of the battery remaining capacity estimation device.

A positive terminal and a negative terminal of the battery 2, a fixed contact of the ignition switch 3 and a charge lamp 5 are connected to the controller 4, and inside the controller 4, the ignition terminal of the alternator 1 is connected. A power generation stop switch 6 for connecting or disconnecting the IG to or from the 12V power supply line is incorporated. In this case, when the alternator 1 stops generating power for the purpose of diagnosing the battery remaining capacity, the charge lamp 5 is turned off, but when the alternator 1 is out of order, the charge lamp 5 is turned on. .

The controller 4 receives the load information, in other words, the battery terminal voltage VB, which varies depending on the charging state of the battery 2 and the number of electric loads and driving states of the electric loads installed in the vehicle. The remaining capacity of the battery 2 is diagnosed, and the result of the diagnosis is displayed on, for example, a display unit or the like arranged on an instrument panel or the like.

That is, in the battery remaining capacity estimating apparatus according to the present embodiment, the controller 4 is operated when a plurality of electric loads mounted on the vehicle are driving and the engine is rotating.
Turns off the built-in power generation stop switch 6 to turn on the ignition terminal IG of the alternator 1.
The power generation of the alternator 1 is temporarily stopped by disconnecting from the 2V power supply line (section from time t1 to t2 in FIG. 2), the battery 2 alone drives a plurality of electric loads, and the terminal voltage VB of the battery 2 at the time of driving the electric loads. The remaining capacity of the battery 2 is estimated by observing the fluctuation (section between the curves L1 and L2 in FIG. 2). In this case, when the battery 2 is sufficiently charged, the battery terminal voltage VB drops as shown by the curve L1 in FIG. 2, and when the battery 2 is insufficiently charged, the battery terminal voltage VB shows the curve in FIG. It descends like L2.

Next, the operation of this embodiment constructed as described above will be described with reference to FIG.

The controller 4, which constitutes the main part of the battery remaining capacity estimating apparatus, operates when a plurality of electric loads mounted on the vehicle are driving (step S1) and the vehicle engine is rotating (step S2). The built-in power generation stop switch 6 is turned off to disconnect the ignition terminal IG of the alternator 1 from the 12V power supply line, thereby stopping the power generation by the alternator 1 (step S3). As the alternator 1 stops generating electricity, the plurality of electric loads are driven by the battery 2 alone (step S4).

The controller 4 drives the plurality of electric loads by the battery 2 alone (time t1 to time t2 in FIG. 2).
(Section), the terminal voltage VB of the battery 2 is estimated (step S5). Then, how the battery terminal voltage VB fluctuates in the section from time t1 to t2 in FIG.
That is, it is monitored whether it is close to the curve L1 (the state where the battery 2 is sufficiently charged) or the curve L2 (the state where the battery 2 is insufficiently charged) in FIG. 2 to estimate the remaining capacity of the battery 2 ( Step S6).

In this case, when the remaining capacity of the battery 2 is sufficient, the battery terminal voltage VB falls relatively gently as shown by the curve L1 in the section from time t1 to t2, but the remaining capacity of the battery 2 is reduced. When there is not much, the battery terminal voltage VB is the curve L2 in the section from time t1 to t2.
It drops sharply as shown by. The degree of decrease in the battery terminal voltage VB changes depending on the driving state (whether or not to drive) and the number of electric loads, but if the type and the number of electric loads are known in advance, the battery terminal voltage VB decreases. Since the degree of can be predicted, the remaining capacity of the battery 2 can be estimated by taking that amount into consideration.

After that, the controller 4 switches the built-in power generation stop switch 6 from the off state to the on state, and connects the ignition terminal IG of the alternator 1 to the 12V power supply line to restart the power generation by the alternator 1 ( Step S7). In this case, after the power generation of the alternator 1 is stopped, the remaining capacity diagnosis of the battery 2 described above is finished in a short time, the power generation of the alternator 1 is restarted, and the normal state is restored.

As described above, according to the battery remaining capacity estimating apparatus of the present embodiment, the power generation of the alternator 1 is temporarily stopped while a plurality of electric loads mounted on the vehicle are driving and the engine is rotating. Then, the battery 2 alone drives a plurality of electric loads, and the remaining capacity of the battery 2 is estimated by monitoring the variation of the terminal voltage VB of the battery 2 when the electric load is driven. It is possible to confirm the state of charge of the battery 2 (size of remaining capacity) even while the vehicle is operating, without visually observing the battery electrolyte or measuring the specific gravity of the battery electrolyte.

Further, according to the battery remaining capacity measuring apparatus of this embodiment, since the battery charge state measuring controller only needs to be incorporated into the existing circuit including the alternator, the battery, the ignition switch, etc., the apparatus can be manufactured at low cost. Can be realized.

In this embodiment, the battery remaining capacity is estimated based on the battery terminal voltage, but it is 12V.
It is also possible to estimate the battery remaining capacity based on the voltage of the power supply line.

In this embodiment, if the number of electric loads being driven is small when the alternator 1 stops generating electricity, the battery 2 is used as a dummy electric load prepared in advance.
It is also possible to estimate the battery remaining capacity based on the fluctuation of the battery terminal voltage at that time.

[0023]

As described above, according to the battery state of charge estimation apparatus of the present invention, the power generation by the generator is stopped at a predetermined time while the engine is being driven, and when the power generation of the generator is stopped, electric power is supplied from the battery to the electric load. To estimate the remaining capacity of the battery by monitoring the fluctuation of the terminal voltage of the battery at the time of power supply from the battery to the electric load, and to perform control to start the generator after the estimation of the remaining capacity is completed. The remarkable effect that the remaining capacity of the battery can be accurately confirmed even while the vehicle is operating without visually observing the battery electrolyte or measuring the specific gravity of the battery electrolyte as in the conventional case can be achieved.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an electrical configuration of a main part of a vehicle equipped with a battery state-of-charge estimating device of the present embodiment to which the present invention is applied.

FIG. 2 is an explanatory diagram showing changes with time of a battery terminal voltage and an ignition voltage in the present embodiment.

FIG. 3 is a flow chart of a battery remaining capacity estimation operation in the present embodiment.

FIG. 4 is a schematic diagram showing an estimated state of specific gravity of a battery electrolyte in a conventional example.

FIG. 5 is a circuit diagram showing an electrical configuration of a vehicle main part in a conventional example.

[Explanation of symbols]

 1 Alternator as a generator 2 Battery 4 Controller 6 Power generation stop switch

Claims (1)

[Claims] 1. A battery remaining capacity estimation device that is installed in an engine-driven vehicle equipped with a generator that is connected to a battery and an electric load and that charges the battery and supplies power to the electric load. A function of stopping power generation by the generator at a predetermined time while the engine is being driven, a function of supplying electric power from the battery to the electric load when the power generation of the generator is stopped, and a power supply from the battery to the electric load A controller provided with a function of occasionally monitoring a variation in the terminal voltage of the battery and estimating the remaining capacity of the battery based on the variation of the terminal voltage, and a function of starting the generator after the estimation of the remaining capacity is completed. A battery remaining capacity estimation device characterized by being connected.