JP2017128186A - Plug-in hybrid service vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid possibility that a voltage of a first battery becomes lower than a reference voltage value after a second battery is charged by an external power source.SOLUTION: A plug-in hybrid service vehicle comprises: a first battery 27 which is charged by an on-vehicle power generator; a second battery 30 which is charged by an external power source 28; a charge switch 44; a DC-DC converter 39; a voltage judgement part 25D, and a charge control part 25F. The charge control part 25F performs charge control in such a way that the second battery 30 is charged from the external power source 28 when it is judged by the voltage judgement part 25D that a voltage of the first battery 27 exceeds a reference voltage value required for start-up of an engine during charging by the external power source 28, and performs charge control in such a way that the first battery 27 is charged from the external power source 28 via the DC-DC converter 39 and so on prior to charging the second battery 30 when it is judged by the voltage judgement part 25D that a voltage of the first battery 27 is equal to or lower than the reference voltage value.SELECTED DRAWING: Figure 5

Description

  The present invention includes an electronic control unit that controls in-vehicle electrical components, a first battery that is charged with electric power from an in-vehicle generator, and a second battery that is charged from an external power source via a charger. It relates to a plug-in hybrid work vehicle.

  In recent hybrid work vehicles, it is considered to charge a battery that supplies power to a traveling motor or the like with electric power from an external power source (see, for example, Patent Document 1).

JP 2012-232724 A (paragraph numbers 0021 to 0022, FIGS. 1 and 5)

  In the plug-in hybrid work vehicle including the first battery and the second battery described above, when the second battery is charged from an external power source, if the output voltage of the first battery is reduced, the second battery is charged. In some cases, the output voltage of the first battery may fall below a reference voltage value required for starting the engine. When the output voltage of the first battery falls below the reference voltage value, the engine cannot be started with the electric power from the first battery after the second battery is charged by the external power source. Further, when the on-vehicle generator is an alternator that operates with power from the engine, the first battery cannot be charged with electric power from the alternator.

  That is, it is desired to avoid the possibility that the output voltage of the first battery falls below the reference voltage value after the second battery is charged by the external power source.

As means for solving the above problems,
A plug-in hybrid work vehicle according to the present invention is charged via an electronic control unit that controls in-vehicle electrical components, a first battery that is charged with electric power from the in-vehicle generator, and a charger from an external power source. A second battery, a charge switch for instructing the electronic control unit to start charging by the external power source, and an output voltage of the charger is converted into a voltage corresponding to the first battery and output to the first battery A DC-DC converter,
The electronic control unit includes: a voltage determination unit that determines whether an output voltage of the first battery exceeds a reference voltage value necessary for starting the engine; and the first battery and the second battery from the external power source. A charge control unit for controlling charging to
When the voltage determination unit determines that the output voltage of the first battery exceeds the reference voltage value during charging by the external power source, the charging control unit receives the second battery from the external power source. When the output voltage of the first battery is determined to be equal to or lower than the reference voltage value by the voltage determination unit, the first charge control is prioritized, Second charge control is performed for charging the first battery from the external power source via the DC-DC converter.

According to this means, when the start of charging by the external power source is commanded by the charging switch, the charging control unit is based on the determination result of the voltage determining unit when the output voltage of the first battery exceeds the reference voltage value Executes the first charging control to charge the second battery from the external power source, and if the output voltage of the first battery is equal to or lower than the reference voltage value, executes the second charging control to perform the second charging from the external power source. 1 Charge the battery.
Thus, regardless of whether the output voltage of the first battery is below the reference voltage value from before the start of charging by the external power source or when the output voltage of the first battery is reduced to the reference voltage value during charging by the external power source. During charging by the external power source, the second battery can be charged while avoiding the output voltage of the first battery being lower than the reference voltage value.
As a result, it is possible to avoid the possibility that the engine cannot be started due to the output voltage of the first battery being lower than the reference voltage value after the second battery is charged by the external power source.

As one of the means for making the present invention more suitable,
A main switch for intermittently energizing the electrical component including the electronic control unit;
The charge switch intermittently energizes the electronic control unit from the first battery,
The electronic control unit includes an intermittent determination unit that determines an intermittent state of the main switch,
The charge control unit holds the charge switch in a connected state and executes the first charge control or the second charge control when the on / off determination unit determines that the main switch is in a disconnected state. In addition, when the main switch is determined to be in the connected state by the intermittent determination unit, the charge switch is not held in the connected state and the first charging control and the second charging control are not executed.

According to this means, the connection state of the main switch that is energized to each electrical component is the driveable state of the electric motor for driving, the operating state of the engine, or the startable state of the engine. Alternatively, the work vehicle can be shifted to a travelable state. Therefore, even if the switching operation to the connection state of the charge switch is performed, the charge control unit switches the charge switch to the cut-off state by not holding the charge switch in the connection state, and starts from the first battery via the charge switch Turn off the power to the electronic control unit. And a charge control part prevents charge of the 1st battery and the 2nd battery by an external power supply by not performing the 1st charge control and the 2nd charge control.
On the other hand, the shut-off state of the main switch in which each electrical component is not energized is a state in which the electric motor for driving cannot be driven, a state in which the engine cannot be started, and a state in which the work vehicle cannot travel. Therefore, when the switching operation to the connection state of the charge switch is performed, the charge control unit maintains the energization from the first battery to the electronic control unit via the charge switch by holding the charge switch in the connection state. . And a charge control part performs charge of the 1st battery or the 2nd battery by an external power supply by performing the 1st charge control or the 2nd charge control.
As a result, it is possible to avoid the possibility that the driver erroneously drives the work vehicle while the first battery or the second battery is being charged by the external power source.

As one of the means for making the present invention more suitable,
It has a connector for external charging,
The connector and the charging switch are arranged in a storage part that is opened and closed by a bonnet.

According to this means, charging by an external power source is always performed with the hood open. Therefore, when the driver tries to drive the work vehicle, if the work vehicle is being charged by an external power source, the bonnet is open, so whether the work vehicle is being charged by an external power source. It becomes easier for the driver to recognize whether or not.
As a result, it is possible to more reliably avoid the possibility that the driver erroneously travels the work vehicle while the first battery or the second battery is being charged by the external power source.

As one of the means for making the present invention more suitable,
The bonnet is a swing opening and closing type,
The connector and the charging switch are arranged at a position on the swing fulcrum side of the bonnet in the storage portion.

According to this means, the open bonnet can function as a rain shield for the connector and the charging switch during charging by the external power source.
Accordingly, it is possible to prevent the connector and the charging switch from getting wet in the rain during charging by the external power source with the hood opened without providing a dedicated rain guard.

It is a left view of a multipurpose work vehicle. It is a top view of a multipurpose work vehicle. It is a rear view of the boarding part which shows arrangement | positioning, such as a transmission lever and a switch. It is a block diagram which shows a part of control structure of a multipurpose work vehicle. It is a circuit diagram which shows schematic structure of the charging circuit for external power supplies. It is a flowchart of external charge control. It is a perspective view of the principal part which shows arrangement | positioning etc. of a connector and a charge switch.

  Hereinafter, as an example of an embodiment for carrying out the present invention, an embodiment in which the present invention is applied to a multipurpose work vehicle of a plug-in hybrid specification that is an example of a plug-in hybrid work vehicle will be described with reference to the drawings.

The direction indicated by the arrow F in FIG. 1 is the front side of the multipurpose work vehicle, and the direction indicated by the arrow U is the upper side of the multipurpose work vehicle.
Further, the direction indicated by the arrow F shown in FIG. 2 is the front side of the multipurpose work vehicle, and the direction indicated by the arrow R is the right side of the multipurpose work vehicle.

  As shown in FIGS. 1 and 2, the multipurpose work vehicle exemplified in this embodiment includes a body frame 1 that forms a framework of a vehicle body, a driving unit 2 that is disposed on the front and rear center side of the vehicle body, and a two-seater boarding. Part 3, steerable left and right front wheels 4 driven by power from driving part 2, left and right rear wheels 5 driven by power from driving part 2, loading platform 6 connected to the rear part of the vehicle body so as to be able to swing up and down , And a swingable bonnet 7.

  The driving unit 2 includes a traveling electric motor 8 (an example of the electrical component A) that supplies power to the left and right front wheels 4, and a gasoline engine (hereinafter referred to as an engine) 9 that supplies power to the left and right rear wheels 5. It is equipped with. The power from the electric motor 8 is transmitted to the left and right front wheels 4 through a gear-type reduction gear 10, a first transmission shaft 11, a differential device 12, a left and right second transmission shaft 13, and the like. The power from the engine 9 is transmitted to the left and right rear wheels 5 through the centrifugal clutch 14, the belt-type continuously variable transmission 15, the gear-type transmission 16, the left and right third transmission shafts 17, and the like. Yes.

  Although not shown, the transmission 16 includes a transmission mechanism, a differential mechanism, left and right brakes, and the like in its casing. The speed change mechanism switches the power from the engine 9 between forward power and reverse power, and switches the forward power between high and low two stages.

  As shown in FIGS. 1 to 3, the riding section 3 includes a liquid crystal display panel 18 (an example of the electrical component A), a steering wheel 19 for front wheel steering, a forward / backward swinging shift lever 20, and an operation located on the left side. A seat 21, a passenger seat 22 on the right side, left and right doors 23, a protective frame 24, and the like are provided. The shift lever 20 includes a neutral position N, a low speed forward position L on the front side of the vehicle body relative to the neutral position N, a high speed forward position H on the front side of the vehicle body relative to the low speed forward position L, and a reverse position R on the rear side of the vehicle body relative to the neutral position N. , And can be switched and held. The transmission lever 20 is operatively linked to a transmission mechanism via a control cable (not shown).

  As shown in FIGS. 1, 2, and 4, this multipurpose work vehicle includes an electronic control unit (hereinafter referred to as an ECU) 25 that controls an in-vehicle electrical component A, an in-vehicle generator 26 (an example of the electrical component A). ) From the first battery 27 (an example of the electrical component A) and the second battery 30 (an example of the electrical component A) charged from the external power source 28, which is a commercial power source, via the charger 29. , Etc.

  The ECU 25 is configured by a microcomputer including a CPU, an EEPROM, and the like. The ECU 25 and each electrical component A are connected so as to be communicable or capable of transmitting power via in-vehicle communication such as CAN (Controller Area Network) or a power line. The generator 26 is an alternator that generates AC electricity using the power from the engine 9 and converts it into DC using a rectifier. The first battery 27 is a 12-volt lead-acid battery that supplies power to each 12-volt electrical component A including the ECU 25. The second battery 30 is a 48-volt lithium ion battery that supplies electric power to the electric motor 8 that is a 48-volt electrical component A. The second battery 30 includes a management system that monitors the voltage, current, temperature, and the like, and controls the second battery 30 by limiting or stopping charging / discharging when an abnormality is detected. The electric motor 8 is an AC motor that operates with AC power from the second battery 30 via the inverter 31 (an example of the electrical component A).

  As shown in FIGS. 3 and 4, the multipurpose work vehicle includes a key switch 32 (an example of the electrical component A) as a main switch for intermittently energizing each electrical component A including the ECU 25. The key switch 32 can be switched between an “OFF” position, an “ON” position, and a “START” position, and can be held between the “OFF” position and the “ON” position. It is urged to return to the “ON” position. When the key switch 32 is artificially operated to the “OFF” position, the key switch 32 is switched to a cut-off state in which the power supply from the batteries 27 and 30 to the electric components A is cut off. When the key switch 32 is manually operated to the “ON” position, the key switch 32 is switched to a connection state in which the electric components A are energized from the batteries 27 and 30. When the key switch 32 is manually operated to the “START” position, it instructs the ECU 25 to start the engine 9 while maintaining the connection state.

  Although not shown, the ECU 25 transmits an engine start command from the key switch 32 to an engine control electronic control unit (hereinafter referred to as E-ECU). The E-ECU performs engine start control for starting the engine 9 by operating a starter motor (an example of the electrical component A) based on the engine start command. The E-ECU is configured by a microcomputer including a CPU, an EEPROM, and the like.

  As shown in FIGS. 3 and 4, the ECU 25 controls the operation of the determination unit 25 </ b> A that determines the operation position of the key switch 32, the travel mode switching unit 25 </ b> B that switches the drive mode for travel, and the electric motor 8. And a driving control unit 25C for traveling. The ECU 25, as a driving mode for traveling, is an electric two-wheel drive mode that drives the left and right front wheels 4 with power from the electric motor 8, an engine two-wheel drive mode that drives the left and right rear wheels 5 with power from the engine 9, and A hybrid four-wheel drive mode for driving the left and right front wheels 4 and the left and right rear wheels 5 is provided.

When the mode switching unit 25B detects that the key switch 32 is switched from the “OFF” position to the “ON” position based on the information from the determination unit 25A, the mode switching unit 25B switches the driving mode for traveling to the electric two-wheel drive mode.
When the mode switching unit 25B detects the switching of the key switch 32 from the “ON” position to the “START” position based on the information from the determination unit 25A, the selection switch 33 for driving mode selection provided in the riding unit 3 is used. Switch to the drive mode selected by the artificial operation of (an example of electrical component A). The selection switch 33 can be switched between a first state in which the engine 2WD mode is selected and a second state in which the hybrid 4WD mode is selected. When the selection switch 33 is in the first state, the mode switching unit 25B switches the driving mode for traveling to the engine 2WD mode. The mode switching unit 25B switches the driving mode for traveling to the hybrid 4WD mode when the selection switch 33 is in the second state.
Thus, the driver can select the electric two-wheel drive mode as the driving mode for traveling by operating the key switch 32 from the “OFF” position to the “ON” position, and without operating the engine 9. The vehicle body can be driven. Then, in a state where the engine 9 is operated by operating the key switch 32 from the “ON” position to the “START” position, the driver switches the driving mode for traveling to the engine two-wheel drive mode by operating the selection switch 33. You can switch to hybrid 4WD mode.

In the electric two-wheel drive mode, the drive control unit 25C operates the changeover switch 34 (an example of the electrical component A) for forward / reverse switching provided in the riding unit 3 and the depression operation of the accelerator pedal 35 provided in the riding unit 3. The operation of the inverter 31 is controlled based on the output of the pedal sensor 36 (an example of the electrical component A) that detects the amount. The inverter 31 rotates the electric motor 8 in the rotation direction according to the operation state of the changeover switch 34 based on the control operation of the drive control unit 25C. Further, the inverter 31 outputs a drive control current (for example, a PWM signal) corresponding to the depression amount of the accelerator pedal 35 to the electric motor 8 based on the control operation of the drive control unit 25C.
Thus, in the electric two-wheel drive mode, the driver can switch forward and backward by operating the changeover switch 34 and can adjust the vehicle speed by depressing the accelerator pedal 35.

In the engine two-wheel drive mode, the drive control unit 25C invalidates the operation of the changeover switch 34 and transmits the output of the pedal sensor 36 to the E-ECU. The E-ECU controls the output rotational speed of the engine 9 based on the output of the pedal sensor 36. The operating state of the speed change mechanism is switched according to the operation position of the speed change lever 20.
Thus, in the engine two-wheel drive mode, the driver can perform forward / reverse switching and two-step switching of the forward power by operating the speed change lever 20, and by depressing the accelerator pedal 35. The vehicle speed can be adjusted.

In the hybrid 4WD mode, the drive control unit 25C invalidates the operation of the changeover switch 34 and transmits the output of the pedal sensor 36 to the E-ECU. The drive control unit 25C also outputs an output of a lever sensor 37 (an example of the electrical component A) that detects the operation position of the transmission lever 20, and a rotation sensor 38 (an example of the electrical component A) that detects the output rotational speed of the transmission mechanism. ) To control the operation of the inverter 31. The inverter 31 rotates the electric motor 8 in the rotation direction corresponding to the operation position of the shift lever 20 based on the control operation of the drive control unit 25C. Further, the inverter 31 outputs a drive control current (for example, a PWM signal) corresponding to the output rotation speed of the transmission mechanism to the electric motor 8 based on the control operation of the drive control unit 25C.
Thus, in the hybrid four-wheel drive mode, the driver can perform forward / reverse switching and two-level switching of the forward power for the rear wheels by operating the speed change lever 20, and the accelerator pedal 35. The vehicle speed can be adjusted in a state in which the peripheral speed of the front wheel 4 is matched with the peripheral speed of the rear wheel 5 by the stepping-in operation.

  As the pedal sensor 36, a rotary potentiometer or the like can be employed. As the lever sensor 37, a rotary potentiometer, a multi-contact switch, or the like can be employed. As the rotation sensor 38, an electromagnetic pickup type or the like can be adopted.

As shown in FIGS. 4 and 5, the multipurpose work vehicle includes a DC-DC converter 39 (an example of the electrical component A) that converts the output voltage of the second battery 30 into a voltage corresponding to the first battery 27. Yes. The ECU 25 determines whether or not the output voltage of the first battery 27 exceeds a reference voltage value necessary for starting the engine 9, and each electrical component A of 12 volt system from the second battery 30. The power supply control part 25E which controls the electric power feeding to is provided. Between the 2nd battery 30 and the DC-DC converter 39, the normally open 1st relay switch 40 (an example of the electrical equipment A) which interrupts the electricity supply from the 2nd battery 30 to the DC-DC converter 39 is interposed. It is disguised. When it is determined by the voltage determination unit 25D that the output voltage of the first battery 27 exceeds the reference voltage value, the power supply control unit 25E uses a 12 volt system from the second battery 30 via the DC-DC converter 39. Power supply stop control for stopping power supply to each electrical component A is executed. In addition, when the voltage determination unit 25D determines that the output voltage of the first battery 27 is equal to or lower than the reference voltage value, the power supply control unit 25E receives 12 volts from the second battery 30 via the DC-DC converter 39. Power supply control for supplying power to each electrical component A of the system is executed.
In the power supply control, the power supply control unit 25E switches the first relay switch 40 to a closed state in which the first relay switch 40 can be energized by energizing a relay coil (not shown) of the first relay switch 40 and energizing the relay coil. . Further, the power supply control unit 25E operates the DC-DC converter 39 to convert the output voltage of the second battery 30 into a voltage corresponding to each electrical component A of 12 volt system.
In the power supply stop control, the power supply control unit 25E cannot supply power to the first relay switch 40 by stopping the power supply to the relay coil (not shown) of the first relay switch 40 and deactivating the relay coil. Switch to the open state. The power supply control unit 25E stops the operation of the DC-DC converter 39.
Thereby, for example, even when the first battery 27 continues to be discharged in a state where charging from the generator 26 is not performed by running the vehicle body in the electric two-wheel drive mode for a long time. The possibility that the output voltage of the first battery 27 becomes lower than the reference voltage value and the engine 9 cannot be started can be avoided.

  As shown in FIGS. 4 and 5, the multipurpose work vehicle includes a plug-in charging system 41 that enables charging from the external power supply 28 to the batteries 27 and 30. The charging system 41 includes an external charging connector 42 (an example of the electrical component A) connected to the external power source 28 via the DC-DC converter 39, the first relay switch 40, and the charger 29 described above. (2) A normally open second relay switch 43 (an example of the electrical component A) for intermittently energizing the battery 30 and a charging switch 44 for instructing the ECU 25 to start charging by the external power source 28 are provided. The DC-DC converter 39 can convert the output voltage of the charger 29 into a voltage corresponding to the first battery 27 and output it to the first battery 27 during charging by the external power supply 28.

  Although not shown, the charger 29 includes an AC-DC converter, a DC-DC converter, an information management unit that acquires and manages information related to charging, and the like. As a result, the charger 29 converts the power from the external power supply 28 from AC to DC, and then converts it to a voltage according to the specifications of the second battery 30 and supplies it to the charging system 41. The information management unit is configured to be able to communicate with the ECU 25. The charging switch 44 commands the start of charging by the external power supply 28 by energizing the ECU 25 from the first battery 27. The charging switch 44 is an artificially operated momentary switch that returns to a cut-off state in which the energization from the first battery 27 to the ECU 25 is cut off. The charging switch 44 includes a self-holding circuit 44 </ b> A that enables holding in a connected state that enables energization from the first battery 27 to the ECU 25.

As shown in FIGS. 4 and 5, the ECU 25 includes a charge control unit 25 </ b> F that controls charging from the external power supply 28 to the first battery 27 and the second battery 30.
When the voltage determination unit 25D determines that the output voltage of the first battery 27 exceeds the above-described reference voltage value during charging by the external power source 28, the charging control unit 25F receives the second battery from the external power source 28. 1st charge control which charges 30 is performed.
The charging control unit 25F gives priority to the first charging control when the voltage determination unit 25D determines that the output voltage of the first battery 27 is equal to or lower than the reference voltage value during charging by the external power source 28. Second charging control for charging the first battery 27 from the external power supply 28 via the DC-DC converter 39 is executed.
That is, when the charging control unit 25F is instructed to start charging by the external power supply 28 by an artificial operation of the charging switch 44, the output voltage of the first battery 27 is set to the reference voltage value based on the determination result of the voltage determination unit 25D. Is exceeded, the first charging control is executed to charge the second battery 30 from the external power supply 28. In addition, when the output voltage of the first battery 27 is equal to or lower than the reference voltage value, the charging control unit 25F executes the second charging control and charges the first battery 27 from the external power source 28.
Thereby, the case where the output voltage of the first battery 27 is below the reference voltage value before the start of charging by the external power source 28, and the case where the output voltage of the first battery 27 drops to the reference voltage value during charging by the external power source 28 Regardless, during charging by the external power supply 28, the second battery 30 can be charged while avoiding that the output voltage of the first battery 27 falls below the reference voltage value.
As a result, after the second battery 30 is charged by the external power source 28, the possibility that the engine 9 cannot be started due to the output voltage of the first battery 27 being lower than the reference voltage value can be avoided. it can.

  In the second charge control, the DC-DC converter 39 converts the output voltage of the charger 29 into a voltage corresponding to the first battery 27 and outputs the voltage to the first battery 27.

As shown in FIGS. 4 and 5, the charging switch 44 intermittently energizes the first battery 27 to the ECU 25 only. The determination unit 25A of the ECU 25 functions as an intermittent determination unit that determines the intermittent state of the key switch (main switch) 31.
When the determination unit 25A determines that the key switch 32 is in the “OFF” position (cut-off state), the charging control unit 25F energizes the self-holding circuit 44A of the charging switch 44 to connect the charging switch 44. And the first charge control or the second charge control is executed. In addition, when the determination unit 25A determines that the key switch 32 is in the “ON” position (connected state) or the “START” position (connected state), the charging control unit 25F does not energize the self-holding circuit 44A. Thus, the charge switch 44 is not held in the connected state, and the first charge control and the second charge control are not executed.
That is, the “ON” position (connected state) or “START” position (connected state) of the key switch 32 that is energized to each electrical component A is the drivable state of the electric motor 8, the operating state of the engine 9, or the engine 9 is a startable state, and is a state in which the vehicle body can be traveled or a transition to the vehicle body travelable state is possible. For this reason, the charging control unit 25F allows the charging switch 44 to return to the cutoff state without energizing the self-holding circuit 44A even if the switching operation of the charging switch 44 to the connected state is performed. As a result, the charging switch 44 returns to the cutoff state, and the power supply from the first battery 27 to the ECU 25 via the charging switch 44 is cut off. Then, the charging control unit 25F prevents the first battery 27 and the second battery 30 from being charged by the external power source 28 by not performing the first charging control and the second charging control.
On the other hand, the “OFF” position (cut-off state) of the key switch 32 that is not energized to each electrical component A is a state in which the electric motor 8 cannot be driven and a state in which the engine 9 cannot be started, and the vehicle body cannot travel. For this reason, when the switching operation of the charging switch 44 to the connected state is performed, the charging control unit 25F energizes the self-holding circuit 44A and holds the charging switch 44 in the connected state. 1 Energization from the battery 27 to the ECU 25 is maintained. Then, the charging control unit 25F performs the first charging control or the second charging control to charge the first battery 27 or the second battery 30 by the external power source 28.
As a result, it is possible to avoid the possibility that the driver accidentally travels the vehicle body while the first battery 27 or the second battery 30 is being charged by the external power source 28.

  Hereinafter, based on the flowchart of FIG. 6, the control operation of the ECU 25 in the external charging control for charging by the external power supply 28 will be described.

The external charging control is executed when the start of charging by the external power source 28 is instructed by an artificial operation of the charging switch 44.
In the external charging control, first, the determination unit 25A determines the operation position of the key switch 32 (step # 1).
When the key switch 32 is in the “ON” position (connected state) or the “START” position (connected state), the charging control unit 25F operates an alarm device (not shown) such as an in-vehicle buzzer for a predetermined time. The key switch 32 is notified that it is in the “ON” position or the “START” position (step # 2). Further, the charging control unit 25F does not energize the self-holding circuit 44A of the charging switch 44, thereby returning the charging switch 44 to the cutoff state and terminating the external charging control (Step # 3).
When the key switch 32 is in the “OFF” position (blocking state), the charging control unit 25F energizes the self-holding circuit 44A and holds the charging switch 44 in the connected state (step # 4). In addition, the charging control unit 25F switches the second relay switch 43 to a closed state in which the second relay switch 43 can be energized by energizing the relay coil (not shown) of the second relay switch 43 and energizing the relay coil. Charging by the external power supply 28 is started (step # 5).
After the start of charging by the external power supply 28, the voltage determination unit 25D determines whether or not the output voltage of the first battery 27 exceeds the reference voltage value described above (step # 6).
When the output voltage of the first battery 27 exceeds the reference voltage value, the charging control unit 25F executes the first charging control for charging the second battery 30 from the external power supply 28 (steps # 7 to 11).
When the output voltage of the first battery 27 is equal to or lower than the reference voltage value, the charging control unit 25F executes the second charging control in preference to the first charging control (steps # 12 to 13).
In the first charge control, the charge control unit 25F maintains the first relay switch 40 in an open state by maintaining the relay coil in a non-excited state without energizing the relay coil of the first relay switch 40 (step S1). # 7). Further, the charging control unit 25F maintains the DC-DC converter 39 in a stopped state (step # 8).
Thereafter, the charging control unit 25F determines whether or not the charging state of the second battery 30 is a fully charged state based on the information from the information management unit of the charger 29 and the information from the management system of the second battery 30. (Step # 9).
If the 2nd battery 30 is not a full charge state, it will return to step # 1.
If the 2nd battery 30 is a full charge state, the charge control part 25F will alert | report that charge of the 2nd battery 30 was completed by operating alarm devices (not shown), such as a vehicle-mounted buzzer, for a predetermined time ( Step # 10) After that, energization to the self-holding circuit 44A is stopped, the charging switch 44 is returned to the cutoff state, and the external charging control is ended (step # 11).
In the second charge control, the charge control unit 25F switches the first relay switch 40 to the closed state and holds it by energizing the relay coil of the first relay switch 40 to bring the relay coil into an excited state (step #). 12). Further, the charging control unit 25F operates the DC-DC converter 39 to convert the output voltage of the charger 29 into a voltage corresponding to the first battery 27 (step # 13). Thereafter, the process returns to step # 1.

As shown in FIG. 7, the connector 42 and the charging switch 44 are arranged in a storage portion 45 that is opened and closed by the bonnet 7.
As a result, charging by the external power supply 28 is always performed with the hood 7 open. Therefore, when the driver tries to drive the multipurpose work vehicle, if the vehicle body is being charged by the external power supply 28, the bonnet 7 is in an open state, and therefore the vehicle body is being charged by the external power supply 28. It becomes easier for the driver to recognize whether or not there is.
As a result, it is possible to more reliably avoid the possibility that the driver accidentally travels the vehicle body while the first battery 27 or the second battery 30 is being charged by the external power source 28.

The connector 42 and the charging switch 44 are arranged at a position on the swing fulcrum side of the bonnet 7 in the storage portion 45.
Thereby, during charging by the external power supply 28, the opened hood 7 can function as a rain shield for the connector 42 and the charging switch 44.
As a result, the connector 42 and the charging switch 44 can be prevented from getting wet during charging by the external power supply 28 with the hood 7 opened without providing a dedicated rain guard.

  The bonnet 7 is provided with a swing fulcrum at the rear end thereof, whereby the connector 42 and the charging switch 44 are arranged at the rear end portion of the storage portion 45.

[Another embodiment]
The present invention is not limited to the configuration exemplified in the above embodiment, and a typical alternative embodiment of the present invention will be exemplified below.

[1] The plug-in hybrid work vehicle may include left and right in-wheel motors as the electric motor 8 for traveling.

[2] The engine 9 may be a diesel engine equipped with a common rail system.

[3] The electronic control unit 25 monitors the voltage, current, temperature, and the like of the first battery 27, the battery monitoring unit for the first battery that monitors the voltage, current, temperature, and the like of the first battery 27. You may provide at least any one of the battery monitoring part for 2nd batteries.

[4] The electronic control unit 25 may be integrated with an electronic control unit for engine control.

[5] The charger 29 may be fixed to the vehicle body.

[6] The second battery 30 may be a nickel metal hydride battery.

[7] The main switch 32 may be a key switch having an operation position for external charging at a position opposite to the operation direction from the “OFF” position to the “ON” position and the “START” position.
In this configuration, while the main switch 32 is also used as the charging switch 44, the driver turns the main switch 32 “ON” when the main switch 32 is charged by the external power supply 28 located at the external charging operation position (blocking state). ”Position (connected state) and“ START ”position (connected state) cannot be operated, so the driver accidentally travels the vehicle body while charging the first battery 27 or the second battery 30 by the external power source 28. It is possible to surely avoid the risk of causing it.

[8] The external charging connector 42 and the charging switch 44 may be provided in a storage portion that is opened and closed by swinging displacement of the driver seat 21 or the passenger seat 22.
In this configuration, charging by the external power source 28 is always performed in a state where the driver's seat 21 or the passenger seat 22 is swung and displaced so as not to be seated. Therefore, when the driver tries to drive the vehicle body, if the vehicle body is being charged by the external power supply 28, the driver seat 21 or the passenger seat 22 is in a state of swinging and displaceable so that the vehicle body cannot be seated. Is easily recognized by the driver as to whether or not charging by the external power source 28 is in progress.
As a result, it is possible to more reliably avoid the possibility that the driver accidentally travels the vehicle body while the first battery 27 or the second battery 30 is being charged by the external power source 28.

  The present invention includes an electronic control unit that controls in-vehicle electrical components, a first battery that is charged with electric power from an in-vehicle generator, and a second battery that is charged from an external power source via a charger. For example, the present invention can be applied to a plug-in hybrid work vehicle such as a multipurpose work vehicle, a tractor, and a mower.

7 Bonnet 9 Engine 25 Electronic control unit 25A Intermittent determination unit 25D Voltage determination unit 25F Charge control unit 26 Generator 27 First battery 28 External power supply 29 Charger 30 Second battery 32 Main switch 39 DC-DC converter 42 Connector 44 Charge switch 45 Storage A A Electrical component

Claims (4)

An electronic control unit for controlling an on-vehicle electrical component, a first battery charged with electric power from an on-vehicle generator, a second battery charged via a charger from an external power source, and the electronic control unit A charge switch that commands the start of charging by an external power supply; and a DC-DC converter that converts the output voltage of the charger into a voltage corresponding to the first battery and outputs the voltage to the first battery,
The electronic control unit includes: a voltage determination unit that determines whether an output voltage of the first battery exceeds a reference voltage value necessary for starting the engine; and the first battery and the second battery from the external power source. A charge control unit for controlling charging to
When the voltage determination unit determines that the output voltage of the first battery exceeds the reference voltage value during charging by the external power source, the charging control unit receives the second battery from the external power source. When the output voltage of the first battery is determined to be equal to or lower than the reference voltage value by the voltage determination unit, the first charge control is prioritized, A plug-in hybrid work vehicle that executes second charge control for charging the first battery from the external power source via the DC-DC converter. A main switch for intermittently energizing the electrical component including the electronic control unit;
The charge switch intermittently energizes the electronic control unit from the first battery,
The electronic control unit includes an intermittent determination unit that determines an intermittent state of the main switch,
The charge control unit holds the charge switch in a connected state and executes the first charge control or the second charge control when the on / off determination unit determines that the main switch is in a disconnected state. If the main switch is determined to be in the connected state by the intermittent determination unit, the charge switch is not held in the connected state and the first charge control and the second charge control are not executed. Item 2. The plug-in hybrid work vehicle according to item 1. It has a connector for external charging,
The plug-in hybrid work vehicle according to claim 1, wherein the connector and the charging switch are arranged in a storage portion that is opened and closed by a bonnet. The bonnet is a swing opening and closing type,
4. The plug-in hybrid work vehicle according to claim 3, wherein the connector and the charging switch are arranged in a portion of the storage portion on the swing fulcrum side of the bonnet.

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