JP2014027850A - Charger for working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charger for working vehicle, capable of fully charging a working vehicle using generated power of a vehicular generator.SOLUTION: The charger for working vehicle includes a working battery charging circuit 90 that charges a working battery 70 by supplying, to a working battery 70, surplus power except electric power used to charge a vehicular battery 82, of electric power generated by a vehicular generator 81. The working battery charging circuit 90 includes a first charging circuit 91 that supplies the surplus power as a predetermined voltage generated by the vehicular generator 81, and a second charging circuit 92 that boosts the surplus power to a higher voltage than the predetermined voltage and supplies the voltage to the working battery 70.

Description

The present invention is mounted on a work vehicle including a vehicle battery for electrically driving a starter motor of an engine and a work battery for electrically driving a work device provided on a traveling body. The present invention also relates to a charging device that performs control for charging a working battery.

In a working vehicle such as an aerial work vehicle, as a method of driving a working device provided on the vehicle body, a driving engine of the aerial work vehicle is driven and a PTO mechanism (power It is known that the hydraulic pump is driven by using the engine power taken out by the take-off mechanism to supply the working oil discharged from the hydraulic pump to the working device to drive the working device. Yes. However, when the engine is driven to extract power, noise is generated due to engine driving noise. For this reason, when a work battery is provided on the vehicle body instead of the PTO mechanism and work is performed using the work device, the engine is stopped and the electric power from the work battery is supplied to the electric motor. There is also known one configured to drive a working device by driving a pump.

When driving a working device using such a working battery, it is necessary to charge the working battery in advance, and a charging method using a commercial power source or a vehicle generator (alternator) provided in the engine ) Is known (for example, see Patent Document 1).

Japanese Patent Publication No. 5-73614

By the way, a vehicular generator (alternator) supplies generated power to electrical components such as a headlamp when the engine is running, and the remaining generated power is used as a vehicular battery for electrically driving the starter motor of the engine. The vehicle battery is supplied and charged.
The vehicle battery only needs to be charged with the electric power supplied to the starter motor, and since it is charged by the vehicle generator when the engine is running, it does not need to be fully charged. Due to a problem, the battery is not fully charged. On the other hand, the working battery is required to be fully charged by performing indentation charging with a high voltage at the end of charging in order to extend the driveable time of the working device. Moreover, the effect of being able to activate and suppress deterioration of the battery can be obtained by fully charging in this way. However, if the power generated by the vehicular generator is supplied to the working battery as it is and charged, the power generation voltage of the vehicular generator is low, so push-in charging at the end of charging cannot be performed.
The work battery could not be fully charged. For this reason, there is a problem that the working device cannot be driven for a long time. Moreover, since the battery cannot be fully charged, there is a problem that it is difficult to obtain an effect of activating and suppressing deterioration of the working battery.

The present invention has been made in view of such a problem, and the working battery can be fully charged using the generated power of the vehicular generator, and as a result, the working device can be driven for a long time. An object of the present invention is to provide a charging device for a working vehicle that can activate and suppress deterioration of the working battery.

In order to solve the above problems, a charging device according to the present invention electrically drives a traveling body that travels by driving wheels by an engine, a vehicular generator that is driven by the engine, and a starter motor that starts the engine. A working vehicle (e.g., a working battery (e.g., boom 30 in the embodiment) provided in the traveling body, and a working battery for electrically driving the working device. It is mounted on an aerial work vehicle 1) in the embodiment and performs control for charging the vehicle battery and the work battery. Of the electric power generated by the vehicle generator, the vehicle battery Working battery charging means for charging the working battery by supplying surplus power to the working battery excluding electric power used for charging ( Eg to work battery charging circuit 90 in the embodiment)
Is provided. The working battery charging means supplies a first charging circuit that supplies the surplus power to the working battery with a predetermined voltage generated by the vehicle generator, and the surplus power is higher than the predetermined voltage. And a second charging circuit that boosts the pressure to supply to the working battery.

In the charging device configured as described above, the first charging circuit supplies most of the surplus power to the working battery while maintaining the predetermined voltage, and the second charging circuit is provided in parallel with the first charging circuit. Preferably, the remaining portion of the surplus power is boosted to a voltage higher than the predetermined voltage and supplied to the working battery.

In the charging device having the above-described configuration, a work battery voltage detector (for example, the voltage detector 75 in the embodiment) that detects the voltage of the work battery, or a work battery current that detects a current of the work battery. Detector (for example, current detector 7 in the embodiment)
6) and when the voltage of the working battery detected by the working battery voltage detector is equal to or lower than a specified voltage, or the current of the working battery detected by the working battery current detector is equal to or higher than a specified current. The working battery is charged using the first charging circuit, and when the voltage of the working battery exceeds the specified voltage, or when the current of the working battery falls below the specified current, the first battery is charged. It is preferable to include charging circuit switching means (for example, the controller 50 and the changeover switch 98 in the embodiment) that switches so as to charge the working battery using a two-charging circuit.

Moreover, the charging device having the above-described configuration preferably includes a working generator that is driven by the engine and supplies generated power to the working battery to charge the working battery.

When the working vehicle charging device according to the present invention is configured as described above, the working battery charging means generates surplus power excluding the power used for charging the vehicle battery among the generated power of the vehicle generator. A first charging circuit that supplies the work battery with a predetermined voltage generated by the vehicle generator, and a second charging circuit that boosts the voltage to a voltage higher than the predetermined voltage and supplies the work battery. Thus, the work battery can be charged using surplus power in the power generated by the vehicular generator. In addition, at the end of charging, surplus power boosted to a high voltage by the second charging circuit can be supplied to the working battery to perform push-in charging, whereby the working battery can be fully charged, As a result, the working device can be driven for a long time. Further, since the battery can be fully charged, the working battery can be activated and the deterioration can be suppressed.

The first charging circuit supplies most of the surplus power to the working battery with the predetermined voltage, and the second charging circuit is provided in parallel with the first charging circuit, and the remaining part of the surplus power If the voltage is raised to a voltage higher than the predetermined voltage and supplied to the work battery, the current flowing through the second charging circuit can be suppressed to a low level, and therefore the second charging circuit can be reduced in size. Thereby, a charging device can be realized at low cost.

In addition, when the voltage of the work battery is equal to or lower than the specified voltage, or when the current of the work battery is equal to or higher than the specified current, the work battery is charged using the first charging circuit, and the voltage of the work battery satisfies the specified voltage. If the charging circuit switching means for switching to charge the working battery using the second charging circuit when the current exceeds the specified current or when the current of the working battery falls below the specified current, the specified voltage is reached, or Until it falls below the specified current, all the surplus power can be supplied to the work battery and charged using the first charging circuit without using the second charging circuit. Then, at the end of charging exceeding the specified voltage or at the end of charging below the specified current, the surplus power boosted to a high voltage using the second charging circuit without using the first charging circuit is used for work. It can be supplied to the battery for indentation charging. Therefore,
Efficient charging according to the state of charge of the work battery can be performed. Further, since the current flowing through the working battery is reduced at the end of charging, the second charging circuit can be reduced in size.

Further, in addition to the vehicular generator, if a working generator driven by the engine to supply the generated power to the working battery and charge the working battery is provided, the surplus power of the vehicular generator and the working power Since the working battery can be charged using the power generated by the generator, the working battery can be rapidly charged in a shorter time.

It is a side view which shows the aerial work vehicle where the charging device which concerns on this invention is mounted. It is a block diagram which shows 1st Embodiment of the charging device which concerns on this invention. It is a block diagram which shows 2nd Embodiment of the charging device which concerns on this invention. It is a graph which shows the charge characteristic at the time of charging a working battery with the charging device which concerns on this invention.

Embodiments of the present invention will be described below with reference to the drawings. As an example of a work vehicle on which a charging device according to the present invention is mounted, an aerial work vehicle 1 having an aerial work device provided on a vehicle body is shown in FIG.

As shown in FIG. 1, the aerial work vehicle 1 has a driving cab 7 in the front part of a vehicle body 2 and is configured based on a truck vehicle that can be driven by wheels 5 disposed on the front, rear, left and right of the chassis frame 3. Has been. A subframe 4 extending in the front-rear direction is attached to the rear side of the driving cab 7 on the chassis frame 3, and the chassis frame 3 and the subframe 4 of the truck vehicle constitute a vehicle body frame. The aerial work vehicle 1 has an engine E (see FIG. 2) inside the vehicle body.
The output of the engine E is transmitted to the rear left and right wheels 5 via the transmission TM and the differential device D so as to be able to travel on the road.

Jacks 14 that lift and support the vehicle body 2 are disposed on the left and right sides of the front and rear of the subframe 4, and each jack 14 is moved downward by driving a jack cylinder (not shown) provided therein. The aerial work vehicle 1 can be stably supported by overhanging. A jack operating device (not shown) provided with an operation lever or the like for operating each jack 14 is provided at the rear part of the vehicle body 2.

A swivel base 20 that is driven by a swivel motor 24 and configured to be capable of horizontal swiveling is disposed at the center of the rear side of the subframe 4. A boom 30 is attached to a support column 21 extending upward from the swivel base 20 by a foot pin 22 so that the boom 30 can swing up and down (can be raised and lowered). In the area of the driving cab 7 and the swivel base 20 on the subframe 4, a plurality of tool boxes for storing tools and equipment necessary for work are provided.

The boom 30 is configured by nesting a base end boom 30a, an intermediate boom 30b, and a front end boom 30c attached to the support column 21 by a foot pin 22 so as to be vertically swingable. By driving the telescopic cylinder 31, the entire boom 30 can be expanded and contracted in the longitudinal direction. Further, the boom 30 can be raised and lowered in the vertical plane by driving a raising and lowering cylinder 23 straddled between the proximal boom 30 a and the support column 21.

A boom head 32 is attached to the distal end portion of the distal end boom 30 c, and a lower end portion of a vertical post 34 is attached to the boom head 32 via a swing pin 33. The vertical post 34 is configured so that a vertical posture is always maintained by a leveling device (not shown) provided in the boom 30 regardless of the undulation angle of the boom 30.

A work table 40 is attached to the upper portion of the vertical post 34 via a work table holding bracket 41 so as to be rotatable in a horizontal plane. A swing motor 43 is provided inside the worktable holding bracket 41. By driving the swing motor 43, the entire worktable 40 can be swung around the vertical post 34 (horizontal turning motion). It can be done.
As described above, since the vertical post 34 is always maintained in a vertical posture, the floor surface of the work table 40 is always held horizontally regardless of the boom 30 undulation angle.

In the work table 40, an operation device 45 including an operation lever for operating the swivel table 20, the boom 30, and the work table 40, various operation switches, and the like is provided. For this reason, in the aerial work vehicle 1, an operator who has boarded the work table 40 operates the operation device 45 to turn the swivel base 20, swing the boom 30 up and down, and swing the work table 40. Thus, the work table 40 can be moved to a desired high position.

As shown in FIG. 2, the operating mechanism of an aerial work device (such as the above-described boom 30) provided on the vehicle body 2 receives an operation signal from the operation device 45 or the jack operation device, and so on. Supply hydraulic oil to operate the controller 50 that controls the operation of the motor, the swing motor 24, the hoisting cylinder 23, the telescopic cylinder 31, the swing motor 43, the jack cylinder, etc. (hereinafter collectively referred to as the “actuator 55”). And a work battery 70 for driving the aerial work device (actuator 55). The controller 50 receives operation signals from the operation device 45 and the jack operation device.

The hydraulic unit 60 is provided in each of a pump drive motor 61 driven by receiving power supplied from the work battery 70 via the inverter 71, a hydraulic pump 62 driven by the pump drive motor 61, and the actuator 55. The control valve 63 is configured to control the operation of the actuator 55 by controlling the supply and discharge of the hydraulic oil supplied from the hydraulic pump 62 to the actuator 55 in accordance with a control signal from the controller 50. The hydraulic pump 62 sucks hydraulic oil from the oil tank T and sends it to the control valve 63, and the hydraulic oil is supplied from the control valve 63 to the actuator 55. A control signal is sent from the controller 50 to the control valve 63.

Next, a first embodiment of a charging device for charging the work battery 70 will be described with reference to FIG. The charging device 80 includes a vehicle generator (alternator) 81 driven by the engine E, a vehicle battery 82 for electrically driving a starter motor (not shown) for starting the engine E, and a vehicle generator. Power generated by 81 is used as work battery 70.
And a work battery charging circuit 90 for charging the work battery 70.

The vehicle generator 81 is always driven when the engine E is running to generate electric power, supplies the generated electric power to electrical components such as a headlamp disposed in the vehicle body 2, and the remaining generated electric power is used for the vehicle. The battery 82 is supplied to the battery 82 and charged. The vehicle battery 82 only needs to have power to be supplied to the starter motor when the engine E is started, and is charged by the vehicle generator 81 when the engine E is operating. For this reason,
It is not required until the battery is fully charged by pushing and charging like a work battery 70 described later.

The work battery charging circuit 90 supplies the generated voltage of the vehicle generator 81 to the work battery 70 while maintaining the predetermined voltage generated by the vehicle generator 81 to charge the work battery 70. And a second charging circuit 92 that charges the work battery 70 by boosting the power generation voltage of the vehicle generator 81 to a voltage higher than the predetermined voltage and supplying the work battery 70. The work battery charging circuit 90 is configured to charge the work battery 70 using surplus power excluding the power used for charging the vehicle battery 82 from the power generated by the vehicle generator 81. The work battery charging circuit 90 includes a vehicle battery 82.
When the battery voltage exceeds a specified voltage, the work battery 70 may be charged using the generated power (surplus power) of the vehicular generator 81.

As shown in FIG. 2, the first charging circuit 91 includes a resistor 93, a diode 94, an operational amplifier 95, and a transistor 96. The surplus power is used for work while maintaining a predetermined voltage generated by the vehicle generator 81. The battery 70 is configured to be supplied. The second charging circuit 92 is provided in parallel with the first charging circuit 91, and is configured to boost the surplus power to a voltage higher than a predetermined voltage generated by the vehicle generator 81 and supply it to the work battery 70. Has been. In the first and second charging circuits 91 and 92, most of the surplus power (most current) of the vehicle generator 81 is supplied to the first charging circuit 91, and the remaining surplus power (slight current) is supplied. ) Are supplied to the second charging circuit 92, each circuit is configured.

The charging device 80 includes a working generator 85 driven by the engine E. The working generator 85 is always driven when the engine E is running to generate electric power, and the generated power is supplied to the working battery 70 to charge the working battery 70.

In the charging device 80 configured as described above, when the engine E is moving (when the aerial work vehicle 1 is traveling), the vehicle generator 81 is driven by the engine E, and the vehicle generator 81 is driven. The electric power generated by is supplied to the vehicle battery 82 and the vehicle battery 82 is charged. Since the vehicle battery 82 is not required to be fully charged as described above, surplus power excluding the power used for charging the vehicle battery 82 out of the generated power of the vehicle generator 81 is used. The battery charging circuit 90 is supplied. The working generator 85 is driven by the engine E.

Most of the generated power (surplus power) of the vehicular generator 81 supplied to the work battery charging circuit 90 is supplied to the first charging circuit 91, and the surplus power is supplied to the vehicular generator 81 by the first charging circuit 91. Is supplied to the working battery 70 with the predetermined voltage generated by the power. On the other hand, the remaining portion of the surplus power is supplied to the second charging circuit 92, and the surplus power is boosted to a voltage higher than the predetermined voltage by the second charging circuit 92 and supplied to the work battery 70. And
Until the charging voltage of the work battery 70 becomes the power generation voltage of the vehicle generator 81 (the predetermined voltage), the work battery is used using the surplus power supplied by the first charging circuit 91 and the second charging circuit 92. 70 is charged. When the charging voltage of the work battery 70 exceeds the power generation voltage of the vehicle generator 81 (the predetermined voltage), the second charging circuit 92 works using the surplus power boosted to a voltage higher than the predetermined voltage. The work battery 70 is pushed and charged, and the work battery 70 can be fully charged. The work battery 70 is also charged using the power generated by the work generator 85 driven by the engine E.

As shown in FIG. 4, if the generated voltage of the vehicle generator 81 is 29 V (volts), for example, the first charging circuit 91 and the second charging circuit 92 until the charging voltage of the work battery 70 reaches 29 V. The working battery 70 is charged using the surplus power supplied by the power supply. When the charging voltage of the working battery 70 exceeds 29V, the voltage supplied by the first charging circuit 91 becomes lower than the voltage for pushing and charging, so that the working battery 70 is connected via the first charging circuit 91. It can no longer be charged. However, the second charging circuit 9
2, the electric power boosted to a voltage (for example, 30 V) higher than the power generation voltage of the vehicle generator 81 is supplied to the work battery 70. Therefore, the work battery 70 is pushed and charged, and the work battery 70 can be fully charged.

As described above, the charging device 80 operates the surplus power, excluding the power used for charging the vehicle battery 82, out of the generated power of the vehicle generator 81 while maintaining the predetermined voltage generated by the vehicle generator 81. The first charging circuit 91 for supplying to the battery for battery 70 and the second charging circuit 92 for boosting the voltage to a voltage higher than the predetermined voltage and supplying it to the working battery 70 are provided, thereby The work battery 70 can be charged using surplus power in the generated power. In addition, at the end of charging, surplus power boosted to a high voltage by the second charging circuit 92 can be supplied to the working battery 70 for indentation charging, whereby the working battery 70 is fully charged. As a result, an aerial work device (such as the boom 30 described above) can be driven for a long time. Further, since the battery can be fully charged, the working battery 70 can be activated and the deterioration can be suppressed.

The first charging circuit 91 supplies most of the generated power (surplus power) of the vehicular generator 81 to the work battery 70 with the predetermined voltage, and the second charging circuit 92 is the first charging circuit 91. The remaining portion of the surplus power is boosted to a voltage higher than the predetermined voltage and supplied to the work battery 70. Accordingly, since the current flowing through the second charging circuit 92 can be reduced, the second charging circuit can be reduced in size, thereby realizing a charging device at low cost.

Further, in addition to the vehicle generator 81, a work generator 85 that is driven by the engine E and supplies the generated power to the work battery 70 to charge the work battery 70 is provided. Therefore, the work battery 70 can be charged using the surplus power of the vehicle generator 81 and the generated power of the work generator 85, and the work battery 70 can be charged rapidly in a shorter time. .

Next, 2nd Embodiment of the charging device for charging the working battery 70 is described using FIG. In the charging device 80 ′, the working battery 70 is charged by switching between the first charging circuit 91 and the second charging circuit 92 according to the charging voltage of the working battery 70. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

In addition to the configuration of the charging device 80 according to the first embodiment, the charging device 80 ′ includes a voltage detector 75 that detects the charging voltage of the work battery 70, and the generated power (surplus power) of the vehicle generator 81.
And a changeover switch 98 for switching which of the first charging circuit 91 and the second charging circuit 92 is supplied.

The detected value of the charging voltage of the work battery 70 detected by the voltage detector 75 is sent to the controller 50. The controller 50 sends a changeover signal to the changeover switch 98 according to the charging voltage of the work battery 70. Specifically, when the charging voltage of the work battery 70 is equal to or lower than the power generation voltage of the vehicular generator 81 (the predetermined voltage), the generated power (surplus power) of the vehicular generator 81 is supplied to the first charging circuit 91. Thus, the changeover switch 98 is changed over. Then, the surplus power is supplied to the work battery 70 by the first charging circuit 91 with the predetermined voltage generated by the vehicle generator 81, and the work battery 70 is charged. When the charging voltage of the work battery 70 exceeds the power generation voltage of the vehicle generator 81 (the predetermined voltage), the changeover switch 98 is switched so that the surplus power is supplied to the second charging circuit 92. The surplus power is boosted to a voltage higher than the predetermined voltage by the second charging circuit 92 and supplied to the work battery 70, the work battery 70 is pushed in and charged, and the work battery 70 is fully charged. it can.

As shown in FIG. 4, if the generated voltage of the vehicle generator 81 is 29 V (volts), for example, when the charging voltage of the work battery 70 is 29 V or less, the generated power (surplus power) of the vehicle generator 81 is Is switched to be supplied to the first charging circuit 91. Then, the first charging circuit 91 supplies the surplus power to the work battery 70 with the generated voltage 29V as it is, and the work battery 70 is charged. When the charging voltage of the work battery 70 exceeds 29V, the changeover switch 98 is switched so that the surplus power is supplied to the second charging circuit 92. Then, the electric power boosted to a voltage (for example, 30 V) higher than the generated voltage by the second charging circuit 92 is supplied to the work battery 70. Therefore, the work battery 70 is pushed and charged, and the work battery 70 can be fully charged.

In this way, the charging device 80 'charges the work battery 70 using the first charging circuit 91 when the charge voltage of the work battery 70 is equal to or lower than the power generation voltage of the vehicle generator 81 (the predetermined voltage). When the charging voltage of the battery 70 exceeds the predetermined voltage, the second charging circuit 9
2 is provided with a changeover switch 98 for switching so as to charge the work battery 70. Therefore, until the charging voltage of the working battery 70 reaches the predetermined voltage, all the surplus power of the vehicle generator 81 is used by the first charging circuit 91 without using the second charging circuit 92. 70 can be charged. Then, at the end of charging exceeding the predetermined voltage, the surplus power boosted to a high voltage using the second charging circuit 92 without using the first charging circuit 91 is supplied to the work battery 70 and pushed in. Charging can be performed. Therefore, efficient charging according to the state of charge of the work battery 70 can be performed. Further, since the current flowing through the work battery 70 is reduced at the end of charging, the second charging circuit 92 can be downsized. In the charging device 80 ′, such an effect can be obtained in addition to the effect obtained by the charging device 80 according to the first embodiment.

In the second embodiment described above, instead of the voltage detector 75, a current detector 76 for detecting the charging current of the work battery 70 may be provided. In that case, the detected value of the charging current of the work battery 70 detected by the current detector 76 is sent to the controller 50. The controller 50 switches the changeover switch 98 according to the charging current of the work battery 70.
Send a switching signal to. Specifically, when the charging current of the work battery 70 is equal to or higher than a specified current, the changeover switch 98 is switched so that the generated power (surplus power) of the vehicle generator 81 is supplied to the first charging circuit 91. Then, the surplus power is supplied to the work battery 70 by the first charging circuit 91 with the predetermined voltage generated by the vehicle generator 81, and the work battery 70 is charged. When the charging current of the work battery 70 falls below the specified current, the changeover switch 98 is switched so that the surplus power is supplied to the second charging circuit 92. The surplus power is boosted to a voltage higher than the predetermined voltage by the second charging circuit 92 and supplied to the work battery 70, the work battery 70 is pushed in and charged, and the work battery 70 is fully charged. it can.

Although the embodiment according to the present invention has been described so far, the scope of the present invention is not limited to that shown in the above-described embodiment. For example, in the above-described embodiment, the working generator 85 is provided, but the working generator 85 may not be provided. Moreover, it may replace with the working generator 85, and may comprise the charger which charges the working battery 70 using a commercial power source. In addition, the working device provided on the vehicle body is not limited to the above-described boom type aerial work device, but a vertical lift type aerial work device, a crane device, a digging pillar device, a dump device (loading by tilting the loading platform) Or the like).

1 Aerial work vehicle (work vehicle)
30 Boom (Working device)
50 controller (charging circuit switching means)
70 Working Battery 75 Voltage Detector (Working Battery Voltage Detector)
76 Current detector (working battery current detector)
80 Charging Device 81 Vehicle Generator 82 Vehicle Battery 85 Working Generator 90 Working Battery Charging Circuit (Working Battery Charging Means)
91 1st charging circuit 92 2nd charging circuit 98 changeover switch (charging circuit switching means)

Claims (4)

A traveling body that travels by driving wheels by an engine, a vehicular generator that is driven by the engine, a vehicle battery that electrically drives a starter motor that starts the engine, and the traveling body. A charging device mounted on a work vehicle including a work device and a work battery for electrically driving the work device, and performing control for charging the vehicle battery and the work battery,
Working battery charging means for charging the working battery by supplying surplus power to the working battery excluding electric power used for charging the vehicle battery among the electric power generated by the vehicle generator. Prepared,
The working battery charging means is
A first charging circuit for supplying the surplus power to the working battery with a predetermined voltage generated by the vehicle generator;
The surplus power is boosted to a voltage higher than the predetermined voltage and supplied to the work battery.
A charging device for a working vehicle comprising a charging circuit. The first charging circuit supplies most of the surplus power to the working battery while maintaining the predetermined voltage,
The second charging circuit is provided in parallel with the first charging circuit, and is configured to boost the remaining portion of the surplus power to a voltage higher than the predetermined voltage and supply the boosted battery to the working battery. The charging device for a working vehicle according to claim 1, wherein the charging device is a work vehicle. A working battery voltage detector for detecting a voltage of the working battery, or a working battery current detector for detecting a current of the working battery;
When the voltage of the working battery detected by the working battery voltage detector is lower than a specified voltage, or when the current of the working battery detected by the working battery current detector is higher than a specified current, the first The working battery is charged using one charging circuit, and when the voltage of the working battery exceeds the specified voltage, or when the current of the working battery falls below the specified current, the second charging circuit is The charging device for a working vehicle according to claim 1, further comprising a charging circuit switching unit that switches so as to charge the working battery. The working vehicle according to any one of claims 1 to 3, further comprising a working generator that is driven by the engine to supply generated power to the working battery to charge the working battery. Charging device.

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