JP3209227B2 - Automatic charging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic charging device mounted on an electric vehicle such as a forklift operated by a battery and capable of selectively performing normal charging and equal charging.

[0002]

2. Description of the Related Art When a storage battery or the like of an electric vehicle is charged, it is usually called normal charging. When the voltage of the storage battery reaches a predetermined value, charging is performed for a predetermined time and the charging is completed. However, when ordinary charging is repeated, there is a slight difference in performance between the cells of the storage battery.Therefore, in some cases, charging after the voltage of the storage battery reaches a predetermined value is referred to as equal charging. This is performed for a longer time than that of the above, and charging is performed in a slightly overcharged manner to equalize the performance of each cell.

[0003] This uniform charging is determined for a tentative purpose such as executing normal charging every five times, for example.
I was going to judge it appropriately. Or Japanese Patent Publication No. 62-12
As disclosed in Japanese Patent Publication No. 3927, when a charge start switch is controlled, it is determined whether normal charging or uniform charging is to be performed from the count value of a counter that counts the number of times of charging, and charging is automatically performed based on the determination result. There is.

[0004]

In the case where normal charging or equal charging is determined based on the experience and feeling of the user, too much or too little equal charging is likely to occur. Excessive equal charge reduces battery fluid and shortens battery life. On the other hand, when the equal charge is too small, the capacity of the storage battery cannot reach the standard amount, or the specific cell is over-discharged and the life is shortened.

[0005] In the case of electric vehicles, the amount of discharge of the storage battery varies depending on whether it operates all day, half a day, or only 1 to 2 hours. If the storage battery discharges very deeply or has been left for a long period of time, it is better to perform uniform charging earlier, or if the repetition of shallow discharges is large, it is better to delay uniform charging. It is better to change the ratio between the normal charge and the equal charge in accordance with. However, when charging is performed by automatically deciding between normal charging and uniform charging based only on the number of times of charging as described in the above-mentioned publication, it is not possible to increase or decrease the uniform charging according to the use situation, and the uniform charging becomes unnecessary. And vice versa.

[0006]

According to the present invention, the charging time counting means and the idle time counting means are reset each time equal charging is performed, and the time corresponding to the charging time in normal charging is counted by the charging time counting means. In addition, the remaining time of the storage battery is accumulated by the leaving time counting means. At the time of charging, the charging method determining means determines whether the charging is normal charging or equal charging based on the charging time count value and the idle time count value. That is, when the sum of the value corresponding to the charging time count value and the value corresponding to the idle time count value is equal to or less than a predetermined value, it is determined that the battery is normal charging, and when it is equal to or greater than the predetermined value, it is determined that the battery is equal charging. If the determination result is normal charging, normal charging is performed, and if the determination result is equal charging, equal charging is performed.

[0007]

FIG. 1 shows an embodiment of the present invention. The automatic charging device can be connected to an AC power supply 11 such as a commercial power supply from an outlet 12. Outlet 1
2 is connected to a switch 13, and this switch 13 is connected to the transformer 1
4 is connected to the rectifier circuit 15. The AC power of the AC power supply 11 input through the switch 13 is converted into an appropriate voltage by the transformer 14, rectified by the rectifier circuit 15, supplied to the storage battery 16, and charged. An AC detection circuit 17 is connected to the outlet 12 and the outlet 12
Is connected to the AC power supply 11, this is detected by the AC detection circuit 17, and this is notified to the control unit 18 composed of a CPU.

The control unit 18 can control the switch 13 through the interface 19, and can perform normal charging, uniform charging, and the like. Operating power is supplied to each unit from a power supply circuit 21 connected to the storage battery 16. The voltage of the storage battery 16 is detected by the voltage detection circuit 22 and supplied to the control unit 18. The charging start switch 23 is connected to the control unit 18 and the S setting unit 24 is connected. The S setting unit 24 includes, for example, a dip switch, and can set a desired numerical value S. Further, the control unit 18 controls the equal charge display element 26 through the interface 25,
The lighting control of the normal charge display element 27 and the completion display element 28 can be performed. As the display elements 26 to 28, for example, light emitting diodes are used.

Next, an example of the operation of the embodiment of the apparatus according to the present invention will be described with reference to the flowcharts shown in FIGS. When the operation of the automatic charging apparatus is started, first, the count value T of the idle time counting means 31 provided in the control unit 18 is reset (S
1) The count value N of the charging time counting means 32 is reset (S2). After the initial reset as described above, the accumulation of the idle time is performed by the idle time counting means 31 (S3). Therefore, in this example, the timer T1 is set (S3a), and it is checked whether or not the timer T1 has expired (S3b). If the timer has expired, that is, if the set time T1 has elapsed, the idle time counting means 31 increments by +1. And returns to step S3a (S3
c). If the timer T1 has not expired in step S3b, the AC power supply 11 is connected, and it is checked whether the AC power has changed from the cut-off state to the input state (S3).
d) If there is no change from the cut-off state to the input state, it is checked whether the AC power has changed from the input state to the cut-off state (S3e). If the AC power has not changed from the input state to the cut-off state, the process returns to step S3b. .

When the AC power supply 11 is connected to the AC power supply 11 by the outlet 12 and the AC detection circuit 17 detects this and notifies the control unit 18, that is, when the AC power changes from the cut-off state to the input state in step S 3 d, it is left unattended. The count value T of the time counting means 31 and the count value N of the charging time counting means 32
And the set value S of the S setting unit 24 are read (S
4) Then, the calculation of aN + bT = Y (a, b: constant) is performed from these (S5). It is determined whether or not the calculation result Y is smaller than the set value S.
If S <Y, it is determined that the charging is equal (S6).

When it is determined that the battery is charged normally (S> Y), FIG.
The normal charge display element 27 blinks as shown in FIG.
7) Wait for the charge start switch 23 to be operated (S)
8). When the charge start switch 23 is operated, the normal charge display element 27 is turned on (S9), and the switch 13 is turned on (S10). Next, normal charging is started (S11), and the completion of normal charging is waited (S12).

Normal charging is performed, for example, as shown in FIG. 4A. First, counting of the timer T2 is started (S1).
2a), the voltage of the storage battery 16 is monitored by the output of the voltage detection circuit 22, and the system waits until the voltage reaches the inflection point (S).
12b) When the charging voltage reaches the inflection point, the counting of the timer T2 is stopped, and the counted value at that time, that is, the time t2 from the start of charging to the point of inflection is obtained (S12).
c). Until now, constant current charging has been used. Next, time T3 = d × t2 is set in the timer T3 (d: constant).
(S12d), final charging (usually constant voltage charging) is performed, and when the timer T3 times out, charging is completed (S12e).

When normal charging is completed in this way, FIG.
As shown in (5), the switch 13 is turned off (S13), the normal charge display element 27 is turned off (S14), and the completion display element 28 is turned on (S15). Next, in this example, c (t2) ² (c is a constant) is calculated using the initial charging time t2 as a value corresponding to the charging time in normal charging, and this value is used as the count value N of the charging time counting means 32. And the process returns to step S3a in FIG. 2 (S16).

If it is determined in step S6 that the charge is equal (S <Y), the equal charge display element 26 flashes as shown in FIG. 3 (S17), and the operation of the charge start switch 23 is awaited (S18). When the charge start switch 23 is operated,
The equal charge display element 26 is turned on (S19), and the switch 13 is turned on.
Is turned on (S20). After that, equal charging starts (S
21), and wait for the completion of the uniform charging (S22). The equal charging is performed, for example, as shown in FIG. 4B. As a procedure, steps S22a to S22e similar to steps S12a to S12e for normal charging are taken. However, in step S22d, T3 = d × t2 + e (e: constant) is set to the timer T3.
Set to. That is, the period of the final charging in the normal charging is lengthened by e.

When the uniform charging is completed as shown in FIG.
The switch 13 is turned off (S23), the uniform charge display element 26 is turned off (S24), the completion display element 28 is turned on, and the process returns to step S1 in FIG. 2 (S25). FIG.
When the AC power changes from the input state to the cut-off state in step S3e, that is, when the AC power is disconnected from the AC power supply 11 by the outlet 12, the completion display element 28 is turned off and the process returns to step S3b (S3f).

[0016] In this way, each time the battery is uniformly charged, the time during which the battery is left unattended is accumulated, and the time corresponding to the charging time in the ordinary charging is accumulated. These two accumulated values are each multiplied by a constant. Whether the normal charge or the equal charge is determined depending on whether the sum Y is smaller or larger than the set value S, there is no need for the user to determine whether the normal charge or the equal charge, and the user can determine the number of times of the normal charge. There is no need to memorize it, and it is not necessary to pay attention to the usage status of whether deep discharge has been performed, shallow discharge has been repeated, or the state of leaving has been long.

In addition, for example, if the standing state is long, T becomes large, and even if the number of times of ordinary charging is small, uniform charging is quickly performed. Similarly, if deep discharging is performed, the charging time of ordinary charging becomes longer. Even if the number of times of charging is small, uniform charging is performed.Conversely, if the frequency of shallow discharge is large, even if the number of times of normal charging is large, equal charging will be delayed, and even when charging is always preferable in consideration of usage conditions, uniform charging will be performed. Done.

In the above description, when the charging start switch 23 is omitted and the AC power supply 11 is connected to the outlet 12, it is automatically determined whether the charging is normal charging or equal charging, and the result may be immediately executed. . The charging time of the normal charging may be counted from the start to the completion thereof, and a value related thereto may be cumulatively added to N.

[0019]

As described above, according to the present invention, the accumulated value of the idle time since the previous equal charge and the accumulated value of the value corresponding to the charge time of the ordinary charge are measured, and these values are considered. It is determined whether normal charging or equal charging is performed, and the result of the determination is executed.Equal charging is appropriately performed according to usage conditions, and equal charging is not too slow or too fast. In addition, the service life of the storage battery is prolonged, and the user does not need to memorize the number of times of normal charging and the usage status, and the operation is simple.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing a part of the operation example of FIG. 1;

FIG. 3 is a flowchart showing a continuation of FIG. 2;

FIG. 4 is a flowchart showing an operation example of normal charging and uniform charging.

Claims (1)

(57) [Claims] 1. A charging time counting means for cumulatively counting a time corresponding to a charging time of ordinary charging, which is reset by equal charging, and a leaving time counting for cumulatively counting a time when a storage battery is left being reset by uniform charging. Means, and a first weight for the count value of the charging time counting means during charging.
A value obtained by multiplying the coefficients, the count value of the standing time counting means
Charging method determining means for determining whether to perform normal charging or equal charging based on a value obtained by adding a value obtained by multiplying the second weighting coefficient; and normal charging when the determination result is normal charging; An automatic charging device comprising: charging executing means for executing equal charging in the case.