JPH073250U - Battery charger - Google Patents

Abstract

(57) [Abstract] [Purpose] The batteries used in parallel are charged evenly. [Configuration] Charging power supply circuit 50 for generating charging DC power
A first wiring for connecting the power output terminals 55a and 55b in parallel to the battery group 20, a second wiring for connecting the charging power supply circuit 50 and the battery group 20 in series, and a first wiring
The battery charger 3 is composed of the wiring and the serial / parallel switching means 40 for selecting the second wiring. Serial-parallel switching means 40
Selects the connection according to the connection between the second wiring and the charging power supply circuit 50. When the second wiring and the charging power supply circuit 50 are connected, the charging power supply circuit 5 is connected by the second wiring.
0 and the battery group 20 are connected in series, and when the second wiring is disconnected from the charging power supply circuit, the power extraction terminals 55a and 55b and the battery group 20 are connected in parallel by the first wiring.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a charging device for a plurality of batteries that are connected in parallel to a power output terminal and are used in parallel.

[0002]

[Prior art]

 Conventionally, work vehicles and the like have been known in which work drive power is obtained from an electric motor. In such a work vehicle, a plurality of batteries are mounted on the vehicle body, and these batteries are connected in parallel to be used to increase the battery capacity so that work can be performed for a long time. However, since the amount of charge of the battery decreases as it is used, it is necessary to charge it each time, but in the past, charging was done while the batteries were connected in parallel.

[0003]

[Problems to be solved by the device]

 However, if charging is performed with the batteries connected in parallel in this way, there is a difference in the charging current of each battery due to the difference in the wiring length from the charging power supply to each battery. There is a problem that the charge state varies from one to another. For this reason, some batteries may be overcharged or some may be insufficiently charged, and if these batteries are used as they are, the life of the entire battery may be shortened.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a battery charger having a configuration capable of uniformly charging batteries used in parallel by using one charging power source. And

[0005]

[Means and Actions for Solving the Problems]

 To achieve such an object, in the present invention, charging power supply means for generating charging DC power, first wiring for connecting power extraction terminals to a plurality of batteries in parallel, and charging power supply means A battery charger is composed of a second wiring for connecting the plurality of batteries in series and a serial / parallel switching unit for selecting parallel connection by the first wiring and series connection by the second wiring. The serial / parallel switching means selects the connection in accordance with the connection between the second wiring and the charging power supply means, and when the second wiring and the charging power supply means are connected, charging is performed by the second wiring. The power supply means and a plurality of batteries are connected in series, and when the second wiring is disconnected from the charging power supply means, the power extraction terminal and the battery are connected in parallel by the first wiring.

During normal use, that is, when the second wire is disconnected from the charging power supply means and charging is not performed, the first wire is selected and the power output terminal is connected from the battery connected in parallel to the first wire. Battery power is taken out and used. Therefore, it is possible to increase the battery capacity and use it for a long time. On the other hand, when the second wiring and the charging power supply means are connected for charging, the serial / parallel switching means connects the charging power supply means and the plurality of batteries in series by the second wiring, and the battery is charged in the series connection state. Is done. If they are connected in series, the charging current of each battery will be the same, and the charging state of each battery will be the same at the time of charging, and the problems of overcharge and insufficient charge will not occur.

[0007]

【Example】

 Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows an aerial work vehicle 10 equipped with the battery charger according to the present invention. A swivel base 12 is attached to a rear portion of a vehicle body 11 of the aerial work vehicle 10 so as to be horizontally swiveled with respect to the vehicle body 11. A boom 13 which is telescopically expandable and retractable is attached to the upper part of the swivel base 12 so as to be able to rise and fall. Furthermore, a workbench 14 is attached to the tip of the boom 13, and an operator can board the workbench 14.

Each operation of the swivel base 12 and the boom 13 is driven by using hydraulic pressure, and the hydraulic pressure is supplied from a hydraulic power unit 15 mounted on the front part of the vehicle body 11. The hydraulic power unit 15 includes a hydraulic pump 16 that generates hydraulic pressure and an electric motor 17 that drives the hydraulic pump 16. Further, an operating device 18 is attached to the workbench 14, and when an operator on the workbench 14 operates this operating device 18, an operation signal is attached to the side surface of the swivel base 12 and a control device 19 is attached. Entered in. The control device 19 supplies the hydraulic pressure generated from the hydraulic power unit 15 to the swivel base 12 and the boom 13 according to the input operation signal, and operates the swivel base 12 and the boom 13. In this way, the operator can move to an arbitrary height through the operation of the boom 13 and the like.

The electric motor 17 and the control device 19 are operated by receiving power supply from a battery group 20 arranged at the bottom of the vehicle body 11. Since each battery constituting the battery group 20 has a reduced charge capacity as it is used, it is necessary to charge the battery each time. The battery charger 3 for this purpose is provided in this aerial work vehicle.

The battery charger 3 will be described with reference to FIG. The battery group 20 is composed of a first row battery group including two batteries 21a and 21b arranged in series and a second row battery group including two batteries 22a and 22b arranged in series. . The configuration of the battery group 20 is not limited to this, and the battery group 20 may have three or more rows of battery groups, and the number of batteries in each row may be one or three or more.

The plus terminals of the first row battery groups 21a and 21b and the second row battery groups 22a and 22b are connected to the wirings 31a and 31b, respectively, and these wirings 31a and 31b are connected to the wiring 32 at the coupling point 32a and the wiring 32. Through the power take-out plus terminal 55a. Similarly, the negative terminals of the first-row battery groups 21a and 21b and the second-row battery groups 22a and 22b are connected to the wiring 34 at the connection point 34a from the wirings 33a and 33b, respectively, and the power extraction minor terminal 55b is connected via the wiring 34. Connected to. By such wiring, the first row battery groups 21a and 21b and the second row battery groups 22a and 22b are connected in parallel to the power output terminals 55a and 55b. That is, this wiring constitutes the first wiring.

The charging device 3 further includes a wiring 35, one end of which is connected to the wiring 31a at the connecting point 35a and the other end of which is connected to the wiring 33b and the connecting point 35b, and one end of which is connected to the connecting point 32a and the other end. It has a wiring 36 connected to the positive terminal of the charging power supply circuit 50 and a wiring 37 having one end connected to the coupling point 34a and the other end connected to the negative terminal of the charging power supply circuit 50. Therefore, the plus terminal of the charging power supply circuit 50 is connected to the positive terminal of the second row battery group 21a, 21b via the wiring 36 and the wiring 31b, and the negative terminal of the second row battery group is connected to the wiring 33b, 35 and. 31a is connected to the positive terminal of the first row battery group, and the negative terminal of the first row battery group is connected to the negative terminal of the charging power supply circuit 50 via wirings 33a and 37. By this wiring, the first column battery groups 21a and 21b and the second battery groups 22a and 22b are connected in series to the charging power supply circuit 50. That is, this wiring forms the second wiring.

The charging power supply circuit 50 has a plug 51. The plug 51 is connected to an outlet 61 of the commercial power supply 60, and an alternating current from the commercial power supply 60 is supplied to the charging power supply circuit 60 at a predetermined voltage. It is designed to be converted to direct current. On the other hand, the power output terminals 55a and 55b are connected to the electric motor 17 and the control circuit 19, and the power of the battery group 20 is supplied from these terminals 55a and 55b.

In this way, the serial / parallel switching means 40 for selecting the power supply from the power output terminals 55a and 55b and the supply of the charging current from the charging power supply circuit 50 is provided in the wiring. The serial-parallel switching means 40 is operated in response to the excitation of the first to fifth coils 41a to 45a provided on the wirings 38 and 39 connecting the wiring 36 and the wiring 37 to each other. 45. As shown in the figure, the first relay 41, the second relay 42, and the third relay 43 are respectively arranged on the wiring 36, the wiring 35, and the wiring 37 to control the connection / disconnection of these wirings. It is a normally open (open when not excited) type relay. The fourth relay 44 and the fifth relay 45 control the connection / disconnection of the wiring 31a between the connection point 35a and the connection point 32a and the disconnection of the wiring 33b between the connection point 35b and the connection point 34a, respectively. It is a normally-closed type relay that controls contact.

In the charging device 3 having the above configuration, the plug 51 is in a removed state during normal work, and the output of the charging power supply circuit 50 is zero. Therefore, the first to fifth coils 41a to 45a are all non-excited, the first to third relays 41 to 43 are open, and the fourth and fifth relays 44 and 45 are closed. As a result, the second wiring is disconnected by the first to third relays 41 to 43, and only the first wiring is connected by the connection of the fourth and fifth relays 44 and 45. Therefore, the first-row battery groups 21a and 21b and the second-row battery groups 22a and 22b are connected in parallel to the power output terminals 55a and 55b via the first wiring, and these batteries are used in a parallel state. .

On the other hand, the plug 51 is connected to the outlet 61 when the battery is charged, for example, when the charge amount of the battery decreases. As a result, the alternating power from the commercial power supply 60 is converted into a direct current in the charging power supply circuit 50 and supplied to the wirings 36 and 37. Therefore, the first to fifth coils 41a to 45a are all energized and excited, the first to third relays 41a to 43a are closed, and the fourth and fifth relays 44 and 45 are opened. Then, contrary to the above, the first wiring is disconnected and only the second wiring is connected. Therefore, the first battery groups 21a and 21b and the second battery groups 22a and 22b are connected to the charging power supply circuit 50 in series via the second wiring. Therefore, the charging current from the charging power supply circuit 50 flows in series in each battery, and the same current flows in all the batteries, so that charging is always performed at the same level. As a result, some batteries will not be overcharged or insufficiently charged.

In the above description, an aerial work vehicle in which a boom having a workbench is arranged on the body of a truck, that is, a so-called truck-mounted aerial work vehicle has been described. The work vehicle equipped with the battery charger is not limited to this, and it goes without saying that it may be a self-propelled aerial work vehicle or another work vehicle. Further, an example in which the serial / parallel switching means is configured by using a relay has been shown, but the present invention is not limited to this, and for example, the serial / parallel switching means may be configured by using a transistor.

[0018]

[Effect of device]

 As described above, the serial / parallel switching means selects the connection in accordance with the connection between the second wiring and the charging power supply means (charging power supply circuit). , When the second wire is disconnected from the charging power supply means, the first wire is selected and battery power is taken out from the battery connected in parallel to the first wire via the power output terminal and used to reduce the battery capacity. It can be made larger and used for a long time. On the other hand, when the second wiring and the charging power supply means are connected for charging, the serial / parallel switching means connects the charging power supply means and the plurality of batteries in series by the second wiring, and the batteries are charged in the series connection state. Since it is performed, the charging current of each battery becomes equal, the charging states of each battery at the time of charging become equal, and it is possible to prevent overcharging and insufficient charging.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram showing a battery charger according to the present invention.

FIG. 2 is a front view showing an aerial work vehicle equipped with this battery charging device.

[Explanation of symbols]

 3 Battery Charging Device 17 Electric Motor 20 Battery Group 40 Serial / Parallel Switching Means 41-45 Relay 50 Charging Power Supply Circuit 55a, 55b Power Extraction Terminal 60 Commercial Power Supply

Claims (1)

[Scope of utility model registration request] 1. A charging power supply means for supplying charging DC power; a first wire having one end connected to a power output terminal and the other end branched into a plurality of wires to be connected in parallel to the plurality of batteries; A second wire that is connectable to the charging power supply means and has the other end connected in series to the plurality of batteries, and the first wire depending on the connection between one end of the second wire and the charging power supply means. Battery charging, comprising parallel connection between the power output terminal and the plurality of batteries, and serial / parallel switching means for selecting series connection between the charging power supply means by the second wiring and the plurality of batteries. apparatus.