JP3949028B2 - Battery forklift charger - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a charger for charging a battery mounted on a battery forklift.
[0002]
[Prior art]
Conventionally, some battery forklifts are equipped with a charger for charging a battery mounted on the vehicle body with an external power source. As this charger, a quasi-constant voltage charger or a constant current charger is adopted. Has been.
[0003]
FIG. 6 is a functional block diagram showing an example of a quasi-constant voltage system charger. This quasi-constant voltage system charger includes a magnet switch 102 for turning on / off the external AC power supply 101, a quasi-constant voltage transformer 103, and a rectifier. 104 and a charge controller 105. The charging controller 105 detects the charging voltage applied to the battery 106 from the rectifier 104, and determines the remaining charging time until the end of charging according to the charging characteristics represented by the relationship between the charging elapsed time and the charging voltage shown in FIG. Calculate. Then, the charging is continued by turning on the magnet switch 102 from the start of charging until the remaining charging time becomes 0, and when the remaining charging time becomes 0, the magnet switch 102 is turned off to end the charging.
[0004]
According to this quasi-constant voltage system charger, the battery 106 can be charged with the current density kept below a certain level in order to reduce the decrease in battery capacity, but the battery 106 is charged over a long period of time (for example, 8 to 10 hours). Must.
[0005]
On the other hand, FIG. 8 is a functional block diagram showing an example of a constant current system charger. This constant current system charger includes a magnet switch 202 for turning on / off the external AC power supply 201, the magnet switch 202 and the battery 205. A switching regulator 203 and a charge controller 204 connected to each other. The charging controller 204 detects the charging voltage applied to the battery 205 from the switching regulator 203, and for example, according to the charging characteristics represented by the relationship between the elapsed charging time and the charging voltage shown in FIG. Calculate time. Then, from the start of charging, the magnet switch 202 is turned on until the remaining charging time becomes zero, and charging is continued. When the remaining charging time becomes zero, the magnet switch 202 is turned off to end the charging.
[0006]
According to this constant current system charger, the battery 205 can be charged with a constant current regardless of the progress of charging, so that so-called rapid charging can be performed in which charging is completed in a short time.
[0007]
[Problems to be solved by the invention]
Since the quasi-constant voltage system charger and the constant current system charger described above have different configurations, conventionally, a charger of any one of the charging systems is selected and mounted on the battery forklift. Therefore, if a quasi-constant voltage method charger is installed, rapid charging like the constant current method cannot be performed, and if a constant current method charger is installed, charging cannot be performed while suppressing a decrease in battery capacity as in the quasi-constant voltage method. It was.
[0008]
Therefore, for example, if a battery forklift that already has a quasi-constant voltage system charger is changed from a quasi-constant voltage system to a constant current system so that rapid charging can be performed, a quasi-low voltage transformer 103 and a rectifier 104 are used. In order to avoid overcharging, it is necessary to replace the charging controller from the quasi-constant voltage charging controller 105 with the constant current charging controller 204 in order to avoid overcharging. There was a problem that the cost for the change was large.
[0009]
An object of the present invention is to solve the problems of the prior art and to provide a battery forklift charger capable of changing the charging method at low cost.
[0010]
[Means for Solving the Problems]
To achieve this object, a magnet switch connected to an external power source, a switching regulator that adjusts power from the external power source and supplies the battery to the battery when the magnet switch is on, and on / off of the magnet switch A charge controller for controlling the charging, and the switching regulator detects an actual charging voltage applied to the battery by the switching regulator, and completes charging when performing constant current charging based on the actual charging voltage The remaining charging time is calculated, and when performing semi-constant voltage charging, the charging is performed by calculating an assumed charging voltage applied to the battery at a time point that is the same as the remaining charging time from the end of charging. Voltage application means for outputting to the controller is provided, and the charge controller is connected to the front of the voltage application means. Based on the assumed charging voltage, the remaining charging time until the end of charging in the case of performing quasi-constant voltage charging is calculated, the magnet switch is held on until this remaining charging time becomes zero, and this remaining charging time is The technical means is characterized in that the magnet switch is turned off when zero is reached.
[0011]
According to this, since the battery is charged by the switching regulator, it can be quickly charged by the constant current method, and the actual charging voltage actually applied to the battery by the voltage applying means is quasi-constant voltage charging. Since it is applied to the charge controller after being converted to a charge voltage (assumed charge voltage) that is assumed to be performed, the battery is overcharged even if a charge controller used for a semi-constant voltage method is used. Things will disappear.
[0012]
In addition, when changing the charging method, it is only necessary to replace the quasi-constant voltage transformer and rectifier and the switching regulator. For example, a battery forklift that already has a quasi-constant voltage method charger can be quickly charged. Can be modified to have
[0013]
In the present invention, the voltage applying means includes, for example, a voltage detecting means for detecting an actual charging voltage applied to the battery by the switching regulator, and the actual charging voltage detected by the voltage detecting means is a predetermined inversion point. Voltage determination means for determining whether or not the voltage is exceeded, charging characteristic data when performing constant current charging expressed by the relationship between the charging elapsed time and the charging voltage, and the relationship between the charging elapsed time and the charging voltage Storage means for storing charging characteristic data in the case of performing the quasi-low voltage system charging, and constant current system charging stored in the storage means when the actual charging voltage exceeds the inversion voltage A remaining charge time calculation means for obtaining a remaining charge time until the end of charging based on the actual charge voltage according to the charge characteristic data, and when the actual charge voltage exceeds the inversion point voltage. In the case of performing quasi-constant voltage charging in accordance with the charging characteristic data of quasi-constant voltage charging stored in the storage means, a time equal to the remaining charge time obtained by the remaining charge time calculation means from the end of charging. When the actual charging voltage is equal to or lower than the repolarization point voltage, an assumed charging voltage calculation means that sets the assumed charging voltage to a predetermined value, and this assumed charging voltage calculation means A configuration may be adopted in which output means for applying the obtained assumed charging voltage to the charging controller is provided.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
A battery forklift charger according to an embodiment of the present invention will be described in detail with reference to the drawings.
[0015]
FIG. 1 is a functional block diagram of a battery forklift charger according to an embodiment of the present invention. This charger includes a magnet switch 2 connected to an external AC power source 1 and a magnet switch 2 connected to the external AC power source 1. A switching regulator 3 that adjusts the electric power from the external power source 1 to supply the battery 5 when the magnet switch 2 is in an on state, and a charge controller 4 that controls the on / off of the magnet switch 2. In addition, the battery 5 is charged with charging characteristics of a constant current method as shown in FIG.
[0016]
The switching regulator 3 is composed of a switching regulator body 6 that applies a voltage to the battery 5 after adjusting the electric power from the external AC power source 1, and a voltage applying means 7 that applies a predetermined voltage to the charging controller 4. Yes. Here, as shown in FIG. 2, the voltage applying means 7 is a constant-current charging characteristic data (see FIG. 9) expressed by the relationship between the elapsed charging time and the charging voltage, the elapsed charging time and the charging voltage. Storage means 71 storing the charge characteristic data (see FIG. 7) of the quasi-low voltage method expressed by the relationship of the above, the actual charging voltage V applied to the battery 5 from the switching regulator body 6 (between the terminals of the battery 5) Voltage detection means 72 for detecting the voltage), and voltage determination means 73 for determining whether or not the actual charging voltage V detected by the voltage detection means 72 exceeds a predetermined inversion point voltage Vp. Further, when the actual charging voltage V exceeds the inversion point voltage Vp, the voltage applying unit 7 performs the remaining charge until the end of charging based on the actual charging voltage V according to the constant current charging characteristics data stored in the storage unit 71. The remaining charge time calculation means 74 for obtaining the time Tr, and when the actual charge voltage V exceeds the reversal point voltage Vp, quasi-constant voltage charging is performed according to the quasi-constant voltage charging characteristic data stored in the storage means 71. In this case, an assumed charging voltage V ′ at a time point that is equal to the remaining charging time Tr obtained by the remaining charging time calculation means 74 from the charging end time is obtained, and the actual charging voltage V is less than or equal to the inversion point voltage Vp. Includes an assumed charge voltage calculation means 75 that makes the assumed charge voltage V ′ a predetermined value, and an output means 76 that applies the assumed charge voltage V ′ obtained by the assumed charge voltage calculation means 75 to the charge controller 4. , Comprising a.
[0017]
FIG. 3 is a flowchart of the control program of the voltage application means 7. In this voltage application means 7, first, the voltage detection means 72 detects the actual charge voltage V (S1), and this actual charge voltage V is the voltage determination means. If it is determined at 73 that it is equal to or less than the reversal point voltage Vp (No in S2), the assumed charging voltage calculation means 75 sets the assumed charging voltage V ′ to a constant value, for example, the reversing point voltage Vp (S3). The voltage V ′ is applied from the output means 76 to the charge controller 4 (S4).
[0018]
On the other hand, when the voltage determination means 73 determines that the actual charge voltage V exceeds the reversal point voltage Vp (Yes in S2), the charge characteristic data of the constant current method stored in the storage means 71 in the remaining charge time calculation means 74 Accordingly, based on the actual charging voltage V, the remaining charging time Tr from the charging voltage detection time to the end of charging is obtained (S5). The storage unit 71 stores charging characteristic data of the constant current method shown in FIG. 9, and the remaining charge time calculation unit 74 stores the elapsed charging time at the time of detection of the charging voltage corresponding to the actual charging voltage V from the storage unit 71. While reading t, the charging elapsed time T at the end of charging is read. Then, the remaining charging time Tr is obtained by performing an operation of subtracting the charging elapsed time t at the charging voltage detection time from the charging elapsed time T at the charging end time.
[0019]
Further, in the assumed charging voltage calculation means 75, the remaining charge time calculation means 74 obtains from the end of charging when performing quasi-constant voltage charging in accordance with the quasi-constant voltage charging characteristic data stored in the storage means 71. An assumed charging voltage V ′ at a time point that is the same as the remaining charging time Tr is obtained (S6). The storage means 71 stores the charge characteristic data of the quasi-constant voltage method shown in FIG. 7, and the assumed charge voltage calculation means 75 reads the elapsed charging time T ′ at the end of charging from the storage means 71. Then, the charging elapsed time t ′ is obtained by performing a calculation of subtracting the remaining charging time Tr obtained by the remaining charging time calculating means 74 from the charging elapsed time T ′ at the end of charging. Then, the assumed charging voltage V ′ is obtained by reading the charging voltage V ′ corresponding to the elapsed charging time t ′ from the storage means 71. The assumed charging voltage V ′ thus obtained by the assumed charging voltage calculation means 75 is applied from the output means 76 to the charging controller 4 (S4).
[0020]
FIG. 4 is a functional block diagram of the charging controller 4. The charging controller 4 stores the charge characteristic data of the quasi-constant voltage method represented by the relationship between the elapsed charging time and the charging voltage shown in FIG. The storage means 41, the voltage detection means 42 for detecting the voltage V ′ applied from the voltage application means 7, and the remaining voltage based on the voltage V ′ detected by the voltage detection means 42 according to the charging characteristic data of the storage means 41. According to the determination result of the remaining charge time calculating means 43 for determining the charge time Tr ′, the remaining charge time determining means 44 for determining whether or not the remaining charge time Tr ′ is greater than 0, and the determination result of the remaining charge time determining means 44. Switch driving means 45 for turning the magnet switch 2 on and off.
[0021]
FIG. 5 is a flowchart of the control program of the charge controller 4. In the charge controller 4, first, the voltage detecting means 42 detects the voltage V 'applied from the voltage applying means 7 (S11), and the remaining charge is detected. In accordance with the quasi-constant voltage charging characteristic data stored in the storage means 41 by the time calculating means 43, the remaining charging time Tr 'until the end of charging is obtained based on this voltage V' (S12). The storage means 41 stores the charge characteristic data of the quasi-constant voltage method shown in FIG. 7, and the remaining charge time calculation means 43 reads the elapsed charge time t ′ corresponding to the voltage V ′ from the storage means 41, and The charging elapsed time T ′ at the end of charging is read. Then, a remaining charging time Tr ′ is obtained by performing a calculation of subtracting the charging elapsed time t ′ from the charging elapsed time T ′ at the end of charging. The remaining charging time Tr ′ is equal to the remaining charging time Tr obtained by the remaining charging time calculating unit 74 of the voltage applying unit 7.
[0022]
Then, the remaining charge time determination means 44 determines whether or not the remaining charge time Tr ′ is greater than 0 (S13). If it is determined that the remaining charge time Tr ′ is greater than 0 (Yes in S13), the switch drive means 45 is magnetized. The switch 2 is turned on (S14), and if it is 0 or less (No in S13), the switch driving means 45 turns off the magnet switch 2 (S15).
[0023]
Thus, while using the charge controller 4 that is originally used only for quasi-constant voltage charging, the battery 5 can be rapidly charged by the constant current method using the switching regulator 3, and the battery 5 is overcharged. There is no fear of being done.
[0024]
In addition, quick charging can be achieved by a very simple modification in which the quasi-constant voltage transformer and rectifier of the conventional quasi-constant voltage charger already mounted on the battery forklift are replaced with the switching regulator 3 incorporating the voltage applying means 7. Since there is no need to replace the charge controller, it can be modified inexpensively.
[0025]
【The invention's effect】
As described above, according to the present invention, the quasi-constant voltage transformer and the rectifier can be changed from the quasi-constant voltage system to the constant current system with a simple modification by replacing the quasi-constant voltage transformer and rectifier with a switching regulator having a voltage applying means. The effect of being able to be obtained can be obtained. Further, since it is not necessary to replace the charge controller when changing the charging method, it can be performed at a low cost.
[Brief description of the drawings]
FIG. 1 is a functional block diagram showing a charger according to the present invention.
FIG. 2 is a functional block diagram showing in detail a switching regulator provided in the charger of the present invention.
FIG. 3 is a flowchart of a switching regulator control program.
FIG. 4 is a functional block diagram showing in detail a charge controller provided in the charger of the present invention.
FIG. 5 is a flowchart of a control program of the charge controller.
FIG. 6 is a functional block diagram showing an example of a conventional quasi-constant voltage system charger.
FIG. 7 is a charge characteristic diagram of a quasi-constant voltage method.
FIG. 8 is a functional block diagram showing an example of a conventional constant current system charger.
FIG. 9 is a charge characteristic diagram of a constant current method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 External AC power supply 2 Magnet switch 3 Switching regulator 4 Charge controller 5 Battery 7 Voltage application means 71 Memory | storage means 72 Voltage detection means 73 Voltage determination means 74 Remaining charge time calculation means 75 Assumption charge voltage calculation means 76 Output means

Claims (1)

  A magnet switch connected to an external power source; a switching regulator that adjusts power from the external power source to supply the battery when the magnet switch is in an on state; and a charge controller that controls on / off of the magnet switch; The switching regulator detects an actual charging voltage applied to the battery by the switching regulator, and obtains a remaining charging time until the end of charging when performing constant current charging based on the actual charging voltage. In the case of performing quasi-constant voltage charging, voltage applying means for obtaining an assumed charging voltage applied to the battery at a time that is a time that is equal to the remaining charging time from the end of charging is applied to the charging controller. And the charging controller is quasi-constant based on the assumed charging voltage from the voltage applying means. The remaining charge time until the end of charging in the case of pressure-type charging is obtained, the magnet switch is kept on until the remaining charge time becomes zero, and when the remaining charge time becomes zero, the magnet switch Battery forklift charger characterized by turning off.

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