JPS6021806Y2 - Battery remaining capacity display device for electric vehicles - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a remaining capacity meter that displays the amount of electricity in a battery of an electric vehicle.

There are various methods for measuring the remaining capacity of the battery of an electric vehicle, such as measuring the specific gravity of the battery's electrolyte, measuring the sulfuric acid concentration, measuring the voltage drop, and measuring the amount of discharged electricity. Although it is known, a method of measuring the amount of discharged electricity is suitable for a residual capacity meter because it is easy to quantitatively measure and the characteristic is a straight line.

On the other hand, since the remaining capacity of the battery varies depending on usage conditions such as battery temperature, it is necessary to correct the measurement results when displaying the remaining capacity measured by the various methods described above.

However, the conventional remaining capacity meter with a correction circuit only displays the capacity after correction, and therefore has the inconvenience of not being able to accurately know the actual battery capacity (capacity before correction).

For example, according to Utility Model Publication No. 53-46497, a hydrometer capable of measuring and displaying the specific gravity of battery fluid and a calculator equipped with a scale plate representing the amount of charge or work of the battery are arranged side by side in a battery container. The scale plate is slid in correspondence with the scale of the hydrometer, and a temperature-sensitive member that expands and contracts according to the temperature change of the battery fluid is attached to the scale plate, so that the scale plate is adjusted to the temperature change of the battery fluid. A device for directly reading the battery charge amount is known, which performs temperature correction by moving the battery charge amount based on the temperature.

However, in this type of conventional direct reading device for the battery charge amount, the scale plate moves according to the temperature change of the battery fluid, so it is not possible to display the actual battery charge amount before temperature correction, and it is difficult to know the correction amount due to temperature. It has the disadvantage of not being possible.

Furthermore, since the battery charge amount is displayed on a scale plate, the battery charge amount cannot be read continuously.

This idea was made to improve the above-mentioned drawbacks of conventional battery remaining capacity meters, and by displaying both the measured battery remaining capacity and the correction amount, the remaining battery capacity (corrected) This makes it possible to accurately read the actual battery capacity (accumulated capacity and actual battery capacity) and take appropriate measures such as raising the battery liquid temperature by supplementary charging, and the remaining capacity can be easily read by displaying a lamp. It is an object of the present invention to provide a remaining capacity meter as described above.

An embodiment of this invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a display section of a remaining capacity meter of a battery of an electric vehicle, indicator lights D1 to D8 for displaying the capacity are green light emitting diodes arranged in a row, and indicator lights D1 for correction. D2' and D3' are red light emitting diodes arranged adjacent to indicator lights D1 to D3 for displaying capacity.

Displays 51TD□, D2. on the left side. D3 corresponds to E (Empty) indicating that the remaining capacity of the battery is low, and indicator light D8 at the right end corresponds to F (Full) indicating that the remaining capacity is full.

In addition, the red indicator light D1' indicates that the battery temperature is 20℃, D2
' is 10℃.

D3' displays the correction for 0°C.

Fig. 2 shows the control circuit of the remaining capacity meter, in which 10 is an on-vehicle battery for driving the running motor of an electric vehicle, and 11 is a battery 1.
By measuring the amount of discharged electricity at 0, the voltage e is proportional to the remaining capacity of this battery.

This is a known remaining capacity detection device that generates 1. Reference numeral 12 denotes a battery temperature detector, which detects a signal from a temperature sensor 13 immersed in the electrolyte of the battery 10 with a temperature detection circuit 14, and generates a voltage e that is inversely proportional to the temperature.

2. 15-1 to 15-8 are comparison circuits, and the positive terminals of the comparison amplifiers 16-1 to 16-8 of each comparison circuit receive an output analog signal of the remaining capacity detection device 11.

1 is applied, and reference voltages Vc1t, Vc2t, .

and voltage e. The comparator amplifiers with i being higher than the reference voltage produce output signals and the respective comparator amplifiers 16-1
The display sections D□ to D8 connected to the terminals D□ to 16-8 are made to emit light.

These comparison circuits 15-1 to 15-8 form an analog-to-digital conversion circuit.

On the other hand, the comparison amplifier 17 of the comparison circuits 15-1 to 15-3
A temperature signal e is sent from the temperature sensor 12 to the positive terminals -1 to 17-3.

2 is applied, and another reference voltage ■ is applied to the negative terminal.

□' or VC3'(Vo1'<Vo2'<Vo3'
) is applied, and one of the comparison amplifiers 17-1 to 17-3 produces an output depending on the battery temperature.

The output terminals of the comparison amplifiers 16-1 to 16-3 are connected to indicator lights D1 to D3 via transistors 18-1 to 18-3, respectively, and the output terminals of the comparison amplifiers 17-1 to 17-3 are connected to display lights D1 to D3 through transistors 18-1 to 18-3, respectively. Light D□' to D3'
are connected and the transistors 18-1 to 18
-3 is connected to the base.

With this configuration, for example, when the comparator amplifier 16-1 is producing an output, when the comparator amplifier 17-1 produces an output of "1", the transistor 18-1 is cut off and the green indicator lamp D□ goes out.

Note that the red display section D□' is lit.

Next, the operation will be explained.

The remaining capacity of the battery 10 is now full, and the output voltage e of the remaining capacity detection device 11.

Which standard value is 1■?

1 to vc8, all comparison amplifiers 16
The outputs of -1 to 16-8 become "1", and each indicator light to D8 lights up.

On the other hand, when the battery temperature is, for example, between 15°C and 25°C, the output voltage e of the temperature detector 12.

2 is ■. 2′ and ■.

1', and the comparison amplifier 17-1 outputs the output 6419.
9, the red indicator lamp D□' for correction lights up, and the transistor 18-1 is cut off, so that the indicator lamp D□ does not light up.

In this state, ■.

□'<e02<V. Since 2'<Vc3', the output of the comparator amplifier 16-2, 16-3 is 0'', and the transistor 1
8-2.18-3 is conductive and the green indicator light D2. D
3 is lit.

The lighting state at this time is shown in FIG. When the remaining capacity of the battery 10 decreases, the voltage eO1 becomes low. For example, when it becomes lower than the reference voltage VC5, the comparator amplifier 16-8.1
6-7. The output of 16-6゜16-5 becomes 0゛, while the output of comparison amplifiers 16-1 to 16-4 becomes ``41 u''.
becomes.

Therefore, the display illusions D5 to D8 are off, D, to D
2 lights up.

Thereafter, the output voltage e01 of the remaining amount detection device 11 is set to the reference value V in the same manner.

4 or less, the outputs of the comparison amplifiers 16-4 to 16-8 are "0" and the indicator lights D4 to D8 are turned off.

On the other hand, the outputs of comparison amplifiers 16-1 to 16-3 are 1.

In this state, if the battery temperature is between 5℃ and 15℃,
Output weight of temperature sensor 12.

2 is ■. 3'>202>VC2'>VCI', the output of the comparator amplifier 17-3 is 0', and the output of the comparator 17-2.17-1 is '1'.

Therefore, the red indicator lights D1' and D2' for correction are lit, while the transistors 18-1, 18-2 are cut off,
Green indicator light D1. D2 does not light up.

This state is shown in FIG.

If the battery temperature is between 0°C and 5°C, the temperature detector 12
The output voltage e.

2 is e. 2>V-3'>V, 2'>Vo1', and the outputs of the comparison amplifiers 17-1 to 17-3 become 1', and the red indicator lamps D1', D2', and D3' light up.

At this time, all transistors 18-1 to 18-3 are cut off and the green indicator light does not light up.

This state is shown in FIG. As can be seen from Figures 5 to 7, E indicates the limit of remaining capacity depending on battery temperature.
The dot appears to move left and right, and the remaining capacity is corrected.

Figures 3 and 4 are examples in which temperature correction is performed on the full side.

In each figure, parts that are equivalent to those in the embodiment shown in FIGS. 1 and 2 are given the same reference numerals, and explanations of those parts will be omitted.

In this embodiment, the four indicators on the Full side are green indicator lights D5 to D8 and red indicator lights D5' to D8'.

In FIG. 4, 19 is a subtraction circuit, and the positive input terminal receives the output e of the remaining capacity detection device 11.

□ is applied and the output of the temperature detector 12 is also applied to the negative terminal.

is applied, and e03 is applied to the output terminal of this subtraction circuit 19.
” The output of eol e02 is generated.

Note that among the comparison circuits, the circuits 15-1 to 15-1 corresponding to the indicator lights D to D4 also have the output voltage of the subtraction circuit 19.

Comparing amplifiers 16-1 to 16-4 each compare the voltage and the reference voltage.

Further, 15-5 to 15-7 are comparison amplifiers 16-8, 17-8 and transistors 18-8 in the comparison circuit 15-8.
It is composed of a circuit similar to 8.

In this embodiment, for example, if the battery temperature is 20'
When the remaining capacity is full at C, each comparison amplifier 16-
Output e of the subtractor from 1 to 16-8.

3” eol e02 is applied, and at this time V c7<
Since e03 < V cs, the output of the comparator amplifiers 16-1 to 16-8 becomes "1", and the green indicator light D
□ or D7 lights up.

On the other hand, the output voltage e of the temperature detector 12.

2 is 4゛〈ece<V, 7'(VC?' is comparison circuit 1
5-7 (reference voltage of amplifier 17-7), and the output of comparison amplifier 17-8 becomes 1p, red indicator light D8'.
lights up.

If the battery temperature is in the range of 10°C, the output voltage e of the temperature detector 2.

2 goes high and comparator amplifier 17-8 . 17-7 (1
7-7 (not shown) becomes "1", and the red indicator light D8'*D?' lights up.

In this case, the green indicator lights D□ to D6 are lit.

When the battery temperature is 20°C, if the remaining capacity of the battery has decreased to such an extent that indicator lights D□ and D2 are lit, and if the battery temperature reaches 10°C, the output voltage ea2 of the temperature detector 12 increases, and the output voltage width of the subtraction circuit decreases.

Therefore■.

t<eo3<vc2, the output of the comparator amplifier 16-2 becomes "0", the output of the comparator 16-1 becomes 1', and only the indicator lamp D□ lights up.

In this case, the voltage e.

2 is high, the outputs of the comparison amplifiers 17-8 and 17-7 are 1, and the red indicator lights D7' and D8' are lit.

As detailed above, this invention converts the analog output of the remaining capacity detection device of the battery of an electric vehicle into a digital value and lights up a number of indicator lights corresponding to this digital amount. You can tell the remaining capacity just by looking at the light.

Also, depending on the usage conditions such as the signal of the battery temperature detection means,
By lighting up another indicator light arranged adjacent to the above-mentioned light, it is possible to know the accurate remaining capacity of the battery, which compensates for fluctuations in the remaining capacity of the battery caused by usage conditions, and in turn accurately predict the possible driving distance. You will be able to do this.

In addition, since the temperature of the battery can be determined from the lighting position of this correction indicator light, it is easy to know when the battery is fully charged by looking at the lighting status of the indicator light that does not require a table of remaining capacity. .

[Brief explanation of drawings]

Fig. 1 is a front view of a display section used in one embodiment of this invention, Fig. 2 is a circuit diagram showing a control circuit for driving the display section of Fig. 1, and Fig. 3 is another embodiment of this invention. 4 is a circuit diagram showing a control circuit for driving the display section shown in FIG. 3, and FIGS. 5 to 7 are diagrams showing an example of the operation of the display section shown in FIG. 2. It is. Dl to D8... Indicator light for capacity display (green)
, D□', D2', D3'... Indicator light (red) for correction, D5'. D6', D,', D8'...Indicator light for correction (red), 1o...Battery, 11...
・Remaining capacity detection device, 12...Temperature detector, 1
3...Temperature sensor, 14...Temperature detection circuit, 15-1 to 15-8...Comparison circuit (
analog-to-digital conversion circuit).

Claims (2)

[Scope of utility model registration request] (1) Consists of a remaining capacity detection unit that detects the remaining capacity of the battery, a battery liquid temperature detection sensor, and a temperature detection circuit that generates an output corresponding to the liquid temperature, and detects and corrects the usage state of the battery. A plurality of capacitance display light emitters with the same emission color are arranged in a line, and a plurality of correction amount display light emitters with a different emission color are arranged in a line for the capacity display. Display units arranged side by side from one end of the light emitter array, a remaining capacity display control unit that converts the output of the remaining capacity detection unit into a digital signal and causes the capacity display light emitters to sequentially emit light, and a usage status detection unit. A remaining battery capacity display device for an electric vehicle, comprising: a correction amount display control section that converts the output of the above into a digital signal and sequentially causes the correction amount display light emitter to emit light. (2) The correction amount display control unit suppresses the light emission of the capacitance display light emitting body corresponding to the correction amount display light emitting body when the correction amount display light emitting body emits light. Battery remaining capacity display control for electric vehicles.