JP2785316B2 - Charger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The first invention is intended to be able to perform charging at a time when electric power charges are low, such as at night, and the second invention is to start driving of a device to be charged. By setting the time in advance, the charging is completed in a time zone when the power rate is low and before the driving start time.

[Industrial applications]

The present invention relates to a charger for charging a storage battery such as a battery.

[Conventional technology]

2. Description of the Related Art Conventionally, in a device using a battery as a power source, for example, a battery-type forklift, when the voltage of the battery is reduced, the user charges the battery during lunch hours or after the work is finished, when the user does not use the device. I have.

FIG. 14 is a diagram showing a circuit configuration of a conventional charger. As shown in the figure, a transformer 11 is an electromagnetic switch 1 including an overcurrent relay 12 that is turned off when an overcurrent is detected, and a contact 13b that is turned on and off by an electromagnetic contact coil 13a.
3 and connected to an AC power supply 14.

The charging switch 15 is a switch for instructing the start of charging. When the charging switch 15 is operated, the control unit 16 instructs the coil driving circuit 17 to excite the electromagnetic contact coil 13a.

As a result, the electromagnetic switch 13 is turned on to supply a voltage to the transformer 11, and the transformer 11 reduces the input voltage to a predetermined voltage and outputs the input voltage to the rectifier 18.

The rectifier 18 is, for example, a full-wave rectifier circuit including a plurality of diodes. The DC voltage rectified by the rectifier 18 is supplied to the battery 20 via the fuse 19.

The voltage detection circuit 21 is a circuit that detects the voltage of the battery 20, and the detected voltage is output to the control unit 16 to control charging.

The AC detection circuit 22 is a circuit for detecting a power failure or the like, and when the AC detection circuit 22 detects that the power has been turned off, the control unit 16 stores the charging time up to that time in a built-in memory. Then, after the power failure, charging can be continued.

In the charger configured as described above, the charging switch 15
Is operated, the controller 16 first gives an excitation instruction to the coil drive circuit 17, and the electromagnetic contact coil 13a is excited. This allows the contact of the electromagnetic switch 13
13b is turned on, and an AC voltage is applied to the transformer 11. The voltage stepped down by the transformer 11 is further supplied to the rectifier 18
Is converted to DC and supplied to the battery 20.
Is charged.

[Problems to be solved by the invention]

In the above-described conventional charger, charging is started when the charging switch 15 is operated, and charging cannot be performed by selecting a time when the power rate is low, such as at night.

It is an object of the present invention to control charging so that charging is completed during a time period when the power rate is low. Another object is to enable charging during a time period when the power rate is low and to allow a user to set a time at which charging is completed.

[Means for solving the problem]

According to the first aspect of the present invention, there is provided a clocking means for clocking time.
A storage means 2 for storing a time zone where the power rate is low, a voltage detection means 5 for detecting the voltage of the storage battery, and charging the storage battery for a predetermined time, and then changing from a voltage change detected by the voltage detection means 5 to charging. Calculating means 6 for calculating a required time; time required for charging calculated by the calculating means 6;
The charging start time at which the charging is completed during the time period when the power rate is low is calculated based on the time period when the power rate is low stored in the charging section, and the charging is started when the time measured by the timer 1 reaches the charging start time. And control means for controlling to start.

According to a second aspect of the present invention, there is provided a clocking means for clocking time.
A storage unit 2 for storing a time zone where the power rate is low, a drive time setting unit 4 for setting a drive start time of a load of the storage battery, a voltage detection unit 5 for detecting a voltage of the storage battery, and charging the storage battery for a predetermined time. At that time, a calculating means 6 for calculating a time required for charging from a voltage change detected by the voltage detecting means 5, a time required for charging calculated by the calculating means 6, a time zone where a power rate is low, and a load. The charging start time at which the charging of the electric power is low and the charging is completed by the driving start time of the load is determined based on the driving start time of the charging device, and the time measured by the timer 1 reaches the charging start time. And control means 7 for controlling to start charging when the charging is performed (see the principle explanatory diagram of FIG. 1).

[Action]

According to the first aspect of the present invention, the time required to charge the storage battery is calculated, and the charging is performed so that the charging is completed in a time period when the power rate is low. , It is possible to automatically charge the battery at a time when the power charge is low without having to consider when to start charging.

According to the second aspect of the present invention, when charging is instructed, the storage battery is first charged for a predetermined time, and the discharge state of the storage battery is checked from the voltage change of the storage battery at that time, and the time required for charging is determined. calculate. The control means 7 determines the charging start time at which the power rate is low and the charging is completed by the driving start time from the charging time calculated by the calculating means 6 as described above and the set driving start time. Then, the time measured by the timer 1 is compared with the above-described charging start time, and charging is started when the current time reaches the charging start time.

Therefore, charging can be performed by selecting a time zone in which the power rate is low, such as at night, and charging can be completed by the time when the load is used by setting the driving start time of the load in advance. .

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 2 to 13.

FIG. 2 is a circuit configuration diagram of the charger according to the embodiment of the first invention.

14, the same circuit blocks as those of the conventional charger shown in FIG. 14 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 2, the time zone storage unit 31 stores a power rate for each time zone and a time at which the time zone starts. For example, if the time zone with the lowest power rate is one type from 0:00 to 6:00. , 0:00 are output to the comparison circuit 34 as charging start times.

The clock circuit 33 is a circuit that measures the current time, and outputs the measured time to the comparison circuit 34.

The comparison circuit 34 compares the time measured by the clock circuit 33 with the charging start time from the time zone storage unit 31, and outputs a match signal to the control unit 32 when they match.

The control unit 32 receives the coincidence signal from the comparison circuit 34, instructs the coil driving unit 17 to excite the electromagnetic contact coil 13a, closes the electromagnetic switch 13, and starts charging.

In the charger having the above configuration, when the charging switch 15 is operated, the time at which the time zone where the power rate is low starts from the time zone storage unit 31 as the charging start time. At this time,
The electromagnetic switch 13 remains open and charging has not started yet.

Then, the charge start time is compared with the current time measured by the clock circuit 33 in the comparison circuit 34, and a match signal is output to the control unit 32 when the current time reaches the charge start time. The control unit 32 closes the electromagnetic switch 13 based on the coincidence signal and starts charging the battery 20.

FIG. 3 shows a comparison between the operation of the conventional charger and the operation of the charger of this embodiment when the charging switch 15 is operated at the same time. In the case of the conventional example, the charging is started when the charging switch 15 is operated, whereas in the case of the embodiment, even if the charging switch 15 is operated, the charging is not performed immediately and the power charge is not performed. Charging has started after a cheap time.

FIG. 4 is a circuit configuration diagram of a second embodiment of the present invention in which a switch 35 for starting charging immediately upon operation is provided in addition to charging during a time period when the power rate is low as described above. .

The operation signal of the switch 35 is input to the control unit 32, and the other circuit configuration is the same as that of FIG.

According to the above circuit, besides charging at a time when the power rate is low, when it is necessary to charge the battery urgently, the switch 35
Can also be charged immediately by operating.

FIG. 5 is a circuit diagram of a third embodiment of the present invention in which the charging start time can be set arbitrarily.

The switch 36 is a switch for switching between setting the time for the time zone storage unit 31 and the time counting circuit 33.The switch 37 stores the charge start time or the corrected time in the circuit selected by the switch 36. This is a switch for setting.

For example, when the switch 36 is switched to the time zone storage unit 31 side, the switch 37 is operated to operate the time zone storage unit.
An arbitrary charging start time can be set in 31, and the set time is displayed on the display unit 38.

Therefore, since the switches 36 and 37 can be operated to set an arbitrary time as the charging start time separately from the time zone in which the power rate is low, the charging can be performed by selecting those times.

Next, FIG. 6 is a diagram showing a circuit configuration of a charger according to an embodiment of the second invention.

6, the same circuit blocks as those in FIGS. 2, 4 and 5 are given the same reference numerals and described.

In FIG. 6, a drive start time storage section 41 is a circuit for storing the drive start time of the forklift set by operating the setting switch 42, and the set time is displayed on the display section 38.

The charging characteristic memory 43 reaches the inversion point voltage after starting charging when the battery is charged based on the time-based power rate, the battery's inversion point voltage at various ambient temperatures, and the respective ambient temperatures. And the change of the battery voltage during the period.

FIG. 7 is a diagram showing a part of the configuration of the charge characteristic memory 43. From the dress 1 to the address n in the memory area, the voltage change from the start of charging to the inversion point voltage is 10 minutes. Data measured at intervals is stored. The voltage detected by the AC detection circuit 22 is stored in the address n + 1, and the ambient temperature at that time is stored in the address n + 2. In the charging characteristic memory 43, voltage data measured under a predetermined ambient temperature may be stored in advance, or the voltage data may be collected when the battery is first charged, and the surrounding data at that time may be collected. The voltage data at the temperature may be stored in the memory area.

The control unit 45 controls charging of the battery 20 based on operation signals of various switches. Control unit
45, when the charge switch 15 is operated and a charge instruction is given, the electromagnetic switch 13 is closed for a certain period of time to perform charging, voltage data of the battery 20 is collected during that time, and then the electromagnetic switch 13 is opened to stop charging .

FIG. 8 is a block diagram of the RAM of the control unit 45.
The voltage data of the battery 20 when the battery 20 is charged for a predetermined time from the address k is stored.
The AC voltage detected at 22 and the ambient temperature at that time are stored in the address k + 2.

The control unit 45 calculates the time until the voltage of the battery 20 reaches the inflection point voltage based on the ambient temperature at that time from the voltage data stored in the RAM and the voltage data in the charging characteristic memory 43. Then, the overall time required for charging is obtained from the calculated time, and further, a charging start time at which charging is completed by the driving start time set by the user in a time zone where the electric power rate is low is obtained.

The charging start time memory 44 stores the control unit 45 as described above.
Is a memory that stores the charging start time calculated by

Next, the operation of the above circuit will be described with reference to the flowchart of FIG.

After setting the driving start time of the forklift in advance by setting switch 42, and operates the charging switch 15, the switch operation is detected in step S _1. Then, charging is energized electromagnetic coil 13a is several tens of minutes in the next step S ₂ is performed, detected by the voltage variation the voltage detection circuit 21 in between the battery 20, the detected voltage is incorporated in the control unit 45 Stored in RAM.

Then in step S _3, the data indicating the voltage change of the battery 20 stored in the RAM of the control unit 45, the charging characteristics memory 43
The time required to charge the battery 20 to be charged to the inversion point voltage is calculated from the data indicating the voltage change during the period from the start of charging stored until the battery reaches the predetermined inversion point voltage to the predetermined inversion point voltage. I do.

For example, data obtained by charging the battery 20 to be charged for a certain period of time becomes a curve shown by a broken line a in FIG. 10, and voltage data stored in the charging characteristic memory 43 is shown in FIG. when a curve, the difference data at a certain point of the voltage data D, which from the data of the difference after the time t _a and D 'alpha, beta, when the γ constant constant, indicated by a curve a the time T _a to the battery voltage reaches the rolling pole voltage expressed by the following equation.

T _a = {(turning point voltage −D) / (D′−D) / t _a } × α +
(Difference in ambient temperature) × β + (difference in AC voltage during charging) × γ Based on the above equation, it is possible to calculate the time until the inversion point voltage is reached at the ambient temperature at that time.

Then, in step S _4, ambient temperature, type of a given charge (charge equalization, normal charging, etc.) and from time to reach the rolling pole voltage obtained in step S _3, the time until the charging is completed calculate. Moreover, several tens of minutes in advance charged for the calculation of the charging time at the next step S _5, and subtracted from the total charging time obtained in step S ₄ obtains the charging time required.

In step S _6, from such a charging time calculated in the the data of low time period when the power rate being charged characteristics memory 43 storing a driving start time set in the driving start time storage unit 41 Then, the charging start time at which the charging is completed in the time zone where the power rate is low and before the set driving start time is completed is calculated and written to the charging start time memory 44.

Thereafter, at step S _7, compares the time measured by the timer circuit 33, and a charging start time stored in the charge starting time memory 44, the current time starts charging when it reaches the charging start time .

As a result, for example, when the charge amount of the battery 20 is large as shown in FIG. Can be completed.

At this time, if the charging is completed at a time significantly earlier than the driving start time set by the user, the battery voltage may drop due to the self-discharge of the battery 20, so that the driving start time and the overall charging The charging start time is appropriately changed based on time or the like.

For example, as shown in FIG. 12, when the charging time is relatively short, the charging time is set by setting the end time of the time zone in which the power rate is low as the charging end time, and subtracting the necessary charging time from the end time. Calculate the time.

Also, if the time required for charging is longer than the length of the time zone where the power rate is low, first, when the time when the time zone where the power rate is low starts is set as the charging start time, the charging is completed by the driving start time. The charging start time is calculated by determining whether or not the charging is started. That is, when the charging is completed by the driving start time when the above time is set as the charging starting time, the time is set in the charging starting time memory 44 as the charging starting time, and the charging is completed by the driving starting time. If not,
A time close to the drive start time is defined as a charge end time, and a required charge time is subtracted from the time to determine a charge start time.

Also, when the time when you want to drive the forklift is far away from the end time of the cheap electricity time zone,
A time close to the drive start time is defined as a charge end time, and a required charge time is subtracted from the time to determine a charge start time.

FIG. 13 shows a modification of the embodiment of the second invention. FIG. 11 shows a circuit configuration of a charger in which a plurality of types of characteristic data are stored in the charging characteristic memory 43 and the switch 46 can be operated to select the characteristic data during charging.

If you try to charge multiple types of batteries with one charger, the charging characteristics differ depending on the type of battery. Therefore, using only one type of charging characteristics data, the charging time obtained by calculation and the actual required charging time Large errors may occur.

Therefore, by storing characteristic data of various types of batteries in the charging characteristic memory 43 and selecting data corresponding to the battery to be charged from the characteristic data, it is possible to select and charge an optimal charging time. .

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to this invention, charging can be performed by selecting a time zone with a low power rate, and charging can be completed by the time when it is desired to drive the load.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 (a) and 1 (b) are diagrams for explaining the principle of the present invention, FIG. 2 is a circuit configuration diagram of a charger according to an embodiment of the first invention, and FIG. FIGS. 4 and 5 are diagrams showing another embodiment of the first invention, FIG. 6 is a circuit configuration diagram of an embodiment of the second invention, FIG. 7 is a memory of a charging characteristic memory FIG. 8 is a configuration diagram of a memory of a RAM incorporated in the control unit, FIG. 9 is a flowchart for explaining the operation of FIG. 6, FIG. 10 is a table for explaining charging characteristics, FIG. FIG. 12 is an explanatory diagram of a charging time, FIG. 13 is a diagram showing a modification of the embodiment of the second invention, and FIG. 14 is a circuit configuration diagram of a conventional charger. DESCRIPTION OF SYMBOLS 1 ... Time measuring means 2 ... Storage means 3 ... Control means 4 ... Driving time setting means 5 ... Voltage detecting means 6 ... Calculating means 7 ... Control means

Claims (2)

(57) [Claims] 1. Time measuring means for measuring the time, storing means for storing a time zone when the power rate is low, voltage detecting means for detecting the voltage of a storage battery, charging the storage battery for a predetermined time, and then detecting the voltage Calculating means for calculating a time required for charging from a voltage change detected by the means; a time required for charging calculated by the calculating means; and a time zone in which the power rate stored in the storage means is low. Control means for determining a charging start time at which charging is completed during a time period when the power rate is low, and controlling to start charging when the time measured by the time measuring means reaches the charging start time. A charger. 2. A time measuring means for measuring time, a storing means for storing a time zone in which a power rate is low, a driving time setting means for setting a driving start time of a load of a storage battery, and a voltage for detecting a voltage of the storage battery. Detecting means, charging the storage battery for a predetermined time, calculating means for calculating a time required for charging from a voltage change detected by the voltage detecting means at that time, and a time required for charging calculated by the calculating means Determining a charge start time at which the charge for charging is low and charging is completed by the start time of the load on the basis of the time period when the power charge is low and the drive start time of the load; Control means for controlling charging to be started when the time measured in step (a) reaches the charging start time.