JPH0576255B2 - - Google Patents

Description

[Detailed description of the invention] purpose of invention (Industrial application field) This invention relates to a charger.

(Prior art) Conventionally, chargers for charging the batteries of forklifts, etc. can perform normal charging and equal charging, and switching between them is described in, for example, Utility Model Publication No. 53-48241.
As stated in the publication, when the charging switch is turned on, the number of normal charging is counted, and each time the number reaches a set value, equal charging is performed to equalize the voltage between each cell of the battery. was.

(Problem to be solved by the invention) However, since only the number of normal charges is counted, if the battery is used for deep discharge, that is, repeatedly discharged beyond the specified capacity, the cell-to-cell voltage of the battery will increase. Even though the non-uniformity of the battery becomes noticeable, uniform charging is not performed until the number of normal charging times reaches a specified number of times, so there is a problem that the life of the battery is shortened.

The object of the present invention is to solve the above problems and provide a charger that does not shorten the life of the object to be charged (battery) even if the object to be charged (battery) is deeply discharged.

Structure of the Invention (Means for Solving the Problems) In order to achieve the above object, the present invention provides a charging operation switching means for switching between a normal charging operation and an equal charging operation for an object to be charged, and a charging operation switching means for switching between a normal charging operation and an equal charging operation for an object to be charged, and a charging operation switching means that changes the number of normal charging operations. A storage means for storing information and a discharge state detection means for detecting the discharge state of the object to be charged are provided. Furthermore, a rewriting means operates to rewrite the number of times of normal charging stored in the storage means when it is determined that a discharge of a predetermined capacity or more has been performed based on the detection by the discharge state detection means; The gist of the charger is a changing means for causing the charging operation switching means to change the charging operation from the normal charging operation to the equal charging operation when a predetermined number of times has been reached.

(Function) With the above means, when the rewriting means determines that a discharge of a predetermined capacity or more has been performed based on the detection by the discharge state detection means, the rewriting means operates to rewrite the number of normal charging operations stored in the storage means, and the changing means operates to rewrite the number of normal charging operations stored in the storage means. When the number of times in the storage means reaches a predetermined number, the charging operation switching means changes the normal charging operation to the equal charging operation.

(Example) Hereinafter, an example in which the present invention is embodied in an on-vehicle charger for a battery-type forklift will be described with reference to the drawings.

As shown in FIG. 1, the magnetic switch 1 consists of an electromagnetic coil 1a and a contactor 1b for each phase. When the electromagnetic coil 1a is energized, each contactor 1b is closed, and when the electromagnetic coil 1a is de-energized, At this time, each contactor 1b is opened.

In this embodiment, the transformer 2 is a leaky transformer with a voltage fluctuation rate that has the most suitable characteristics for charging, and the three-phase AC power applied from terminals R, S, and T is used as the object to be charged. It converts the voltage into a voltage suitable for charging the battery 3, and outputs the converted voltage to the three-phase diode rectifier circuit 4. This three-phase diode rectifier circuit 4 is composed of six diodes 5, and rectifies three-phase AC voltage using a three-phase full-wave rectification method to output a DC voltage.

A thermal relay 6 provided between the contactor 1b of the magnetic switch 1 and the transformer 2
is a thermal type overcurrent relay, which operates when an abnormally large input current flows, and the contactor 1 of the magnetic switch 1 is activated by opening the contact 6a.
b is designed to protect the charger by opening it.

The microcomputer 7 as a charging operation switching means, rewriting means, and changing means operates based on a control program stored in a storage device 8 as a storage means. Further, this storage device 8 is made of a non-volatile memory or has a backup power source, so that the number of times N of normal charging is stored and the stored contents are retained even if the power supply to the charger is stopped. It's summery. The microcomputer 7 is adapted to rewrite the normal charging number N in the memory device 8 as appropriate.

Further, a series circuit of the electromagnetic coil 1a of the magnetic switch 1 and the contact 6a of the thermal relay 6 is connected to the microcomputer 7 via an interface 9. By energizing or de-energizing the contactor 1b, the contactor 1b can be opened and closed.

Connected to the microcomputer 7 is a capacity meter 10 of the battery 3, which serves as a discharge state detection means provided in the forklift. This capacity meter 10 calculates the capacity of the battery 3 based on the voltage detection of the battery 3 (the percentage value of the discharged capacity with respect to the predetermined specified capacity of the battery 3), and displays it using an LED (light emitting diode) or the like. It is something. The microcomputer 7 is adapted to detect the discharge state of the battery 3 by inputting a capacity display signal from the capacity meter 10.

Further, a charging switch 11 is connected to the microcomputer 7, and a start signal for starting charging is inputted from the switch 11. The microcomputer 7 is configured to start a timer operation by a built-in timer based on the input of the start signal.

Then, during normal charging, the microcomputer 7 rewrites and stores the contents in order to add "1" to the number of normal charging times N stored in the storage device 8. In this embodiment, the normal charging number N is set to an initial value of "0" and is sequentially increased by "1". Further, the microcomputer 7 changes the display content of the capacity meter 10 when the charging switch 11 is operated.
Even in the case of 100% or more, that is, when the battery 3 is deeply discharged beyond the specified discharge amount, the contents are rewritten to add "1" to the normal charging number N stored in the storage device 8.

Further, the microcomputer 7 changes the normal charging operation to the equal charging operation when the normal charging number N reaches a predetermined normal charging number No (for example, 10 times). Then, in the case of equal charging, the microcomputer 7 clears the count number of the normal charging number N, that is, "0".
The number of times of charging is rewritten and stored in the storage device 8. Incidentally, a series of these timer operations, counting operations of the normal charging number N, and clearing operations of the microcomputer 7 are performed based on program data stored in the storage device 8.

Next, we will explain the operation of the charger configured in this way in a second way.
This will be explained based on the diagram.

First, connect three-phase AC power terminals to terminals R, S, and T. When the microcomputer 7 inputs a start signal accompanying the ON operation of the charging switch 11, it excites the electromagnetic coil 1a of the magnetic switch 1, closes each contactor 1b, and starts supplying power to the battery 3 (the magnetic switch 1).

The microcomputer 7 detects the displayed value of the capacitance meter 10 and determines whether or not the displayed capacity is greater than or equal to the specified capacity of the battery 3, that is, greater than or equal to 100% or less. When it is 100% or more, it is determined that a deep discharge has been performed, the normal charging number data stored in the storage device 8 is read out, "1" is added to the number N, and the number is written in the storage device 8.

Then, when the display value of the capacitance meter 10 is less than 100% or more than 100% and the rewriting operation of the normal charging number N is completed, the microcomputer 7 reads the normal charging number data from the storage device 8 and reads the number N of normal charging. When N is less than the set value No, the normal charging mode is set, and when the normal charging number N is equal to the set value No, the equal charging mode is set.

If the normal charging mode is selected, the microcomputer 7 adds "1" to the normal charging number N and writes the number into the storage device 8. Thereafter, the microcomputer 7 counts the charging time, and when the predetermined charging time for normal charging has elapsed, the excitation coil 1 of the magnetic switch 1 is turned off.
a to a de-energized state and contactor 1b is opened to terminate charging (turning off operation of magnetic switch 1).

Further, when the charging mode is equal, the microcomputer 7 clears the number of normal charging times (N=O) and writes the number of times into the storage device 8.
Furthermore, the microcomputer 7 counts the charging time, and when a predetermined charging time for equal charging (time longer than the normal charging time) has elapsed, the electromagnetic coil 1a of the magnetic switch 1 is de-energized, and the contactor 1b is opened to start charging. (turn off magnetic switch 1).

In this way, the charger of this embodiment detects deep discharge when a normal charging operation is performed and based on the display contents of the capacity meter 10, and adds "1" to the number of normal charging times N each time. The frequency of charging increases. Therefore, battery 3 due to deep discharge
Even if the voltage of each cell becomes non-uniform, it can be quickly dealt with, and the life of the battery 3 can be prevented from becoming short.

The present invention is not limited to the above-mentioned embodiment. For example, in the above-mentioned embodiment, a capacitance meter 10 mounted on a forklift is used as the discharge state detection means. A voltmeter or the like may be provided to detect the state.

Furthermore, in the above embodiment, when the discharge rate of the battery 3 with respect to the specified capacity is 100% or more, the normal charging number N is added by 1, but when the discharge rate is 100% or more or 100% or less, it is added. Furthermore, the added value may be "1", "2" or more depending on the discharge state.

Further, in the above embodiment, when the charging switch 11 is turned on, a deep discharge exceeding the specified capacity is detected, and based on this detection, the normal charging number N is incremented by 1. When the displayed content is detected and a deep discharge exceeding the specified capacity is performed, the number of normal charging times N is determined regardless of whether the charging switch 11 is turned on.
The addition operation may also be performed. In this case, in the above embodiment (deep discharge detection based on the ON operation of the charging switch 11), due to the recovery of the battery capacity after the battery 3 is used (discharged), when the charging switch 11 is turned ON, the battery 3
If the discharge rate with respect to the specified capacity of the battery recovers to less than 100%, the counting operation will not be performed, but this will not happen and deep discharge can be reliably detected and counted.

Effects of the Invention As detailed above, the present invention prevents the life of the charged object from being shortened due to the discharge by changing the frequency of equal charging based on the detection of discharge of the charged object beyond a predetermined level. It can exhibit excellent effects.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram of a charger embodying the present invention, and FIG. 2 is a flow chart for explaining the operation of the charger. Battery...3. Microcomputer...
7. Storage device...8. Capacity meter...10.

Claims (1)

[Scope of Claims] 1. Charging operation switching means for switching between normal charging operation and equal charging operation for the object to be charged, storage means for storing the number of normal charging operations, and discharging means for detecting the discharge state of the object to be charged. a state detecting means; a rewriting means that rewrites the number of normal charges stored in the memory means when it is determined that a discharge of a predetermined capacity or more has been performed based on the detection by the discharge state detecting means; and the memory means. changing means for causing the charging operation switching means to change from normal charging operation to equal charging operation when the number of times has reached a predetermined number.