JP2019134603A - Electric work vehicle - Google Patents

Abstract

To provide an electric work vehicle which can prevent complication of battery energy management, and can easily respond to a request for high safety.SOLUTION: An electric work vehicle 1 which travels by a first motor 26 to which electric power is supplied from a first battery 23, and performs a prescribed work by a second motor 32 to which electric power is supplied from a second battery 30. The electric work vehicle comprises: a vehicle body 2 which includes the first battery 23, the first motor 26 and a power distribution unit 24; an installation body 3 which includes the second battery 30, the second motor 32 and a work device 33, and is installed on the vehicle body 2; a relay circuit 42 which electrically connects the second battery 30 to the power distribution unit 24; and a relay control part 43 which controls connection/disconnection state of the relay circuit 42. The relay control part 43 so makes the power distribution unit 24 and the second battery 30 as to be in an electrical disconnection state during travel of the vehicle body 2.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electric work vehicle.

  Work vehicles equipped with work devices for performing predetermined work such as garbage vehicles, refrigerated vehicles, dump vehicles, mixer vehicles, fire fighting vehicles, etc. generally take out at least a part of the rotational power of the internal combustion engine and hydraulic pumps The working device is driven by a PTO device (Power Take Off) using an operating power source such as a compressor or a compressor.

  In recent years, such work vehicles also employ hybrid vehicles that run on the power of the internal combustion engine and the power of the battery, and electric vehicles that run only on the power of the battery without the internal combustion engine, from the viewpoint of reducing the environmental load. It is being considered. For example, Patent Document 1 discloses a plug-in hybrid tractor including an internal combustion engine and a battery. More specifically, Patent Document 1 discloses a mode in which a PTO motor is driven by the power of an internal combustion engine while driving a traveling motor by battery power, and both a traveling motor and a PTO motor are driven only by battery power. A mode of driving is described.

JP 2012-232724 A

  However, as in the prior art described in Patent Document 1 described above, in an electric vehicle that supplies power from the battery to both the traveling motor and the PTO motor, energy management between the two may be complicated. . More specifically, in such a work vehicle, a control device on the vehicle body side that controls power supplied to the motor for traveling and a control device on the body side that controls power supplied to the PTO motor always communicate with each other. For example, in order to secure the cruising distance, the power supply to the PTO motor is restricted, or the both power demands are adjusted so that they do not overlap.

  In addition, since such a work vehicle supplies high voltage power while traveling from a high voltage battery necessary for traveling to the PTO motor on the body side, high safety requirements are also required on the body side. Need to meet.

  The present invention has been made in view of such a situation, and an object of the present invention is to prevent the complexity of battery energy management and to easily meet the demand for high safety. Is to provide.

<First Aspect of the Present Invention>
The electric work vehicle according to the first aspect of the present invention travels with a first motor supplied with electric power from a first battery, and performs an electric work with a second motor supplied with electric power from a second battery. A vehicle body including a first battery, the first motor, and a power distribution unit that supplies power output from the first battery to the first motor; the second battery; the second motor; A work body driven by the second motor, the body mounted on the vehicle body, a relay circuit for electrically connecting the second battery to the power distribution unit, and connection / disconnection of the relay circuit A relay control unit that controls a state, and the relay control unit electrically disconnects the power distribution unit and the second battery when the vehicle body is running.

  The electric work vehicle according to this aspect supplies electric power necessary for traveling of the vehicle body from the first battery, and also supplies electric power necessary for driving the working device in the bodywork from the second battery. The electrical connection state between the first battery and the second battery is disconnected in the relay circuit. As a result, the electric work vehicle can control the vehicle body and the bodywork with an independent power system during traveling, so that cooperative control between the first battery and the second battery is not necessary.

  Moreover, since the vehicle body and the bodywork are electrically independent from each other when the electric work vehicle according to this aspect is traveling, the high-voltage first battery for traveling is electrically connected to the bodywork. Can be cut. As a result, the electric work vehicle does not require the second battery to have the level of safety required for the high-voltage first battery.

  Therefore, according to the 1st aspect of this invention, the complexity of the energy management of a battery can be prevented, and the electric work vehicle which can respond easily to the request | requirement of high safety can be provided.

<Second Aspect of the Present Invention>
In the electric work vehicle according to the second aspect of the present invention, in the first aspect of the present invention described above, a work control unit for controlling the body is provided in the body, and the relay circuit and A relay control unit may be provided in the vehicle body.

  In the electric work vehicle according to this aspect, the work control unit that controls the bodywork is provided in the bodywork, and the relay circuit and the relay control unit are provided in the vehicle body. The vehicle body and the bodywork can be configured independently. Therefore, according to the second aspect of the present invention, it is possible to provide a simple configuration in which the traveling components are gathered in the vehicle body and the working components are gathered in the bodywork, thereby simplifying the design of the electric work vehicle. As a result, the manufacturing cost can be reduced.

<Third Aspect of the Present Invention>
The electric work vehicle according to a third aspect of the present invention further includes a charge control unit that controls charging of the first battery and the second battery in the first or second aspect of the present invention described above, The charging control unit may control the relay circuit to supply charging power from the external power feeding device to the second battery when the external power feeding device is connected to the vehicle body.

  In the electric work vehicle according to this aspect, when the external power feeding device is connected to the vehicle body, the charging control unit can control the relay circuit so that the charging power can be supplied to the second battery. Thus, according to the third aspect of the present invention, when the external battery is connected to the vehicle body while the first battery and the second battery are independent power supply sources, the first battery and / or the first battery 2 The battery can be charged.

<Fourth aspect of the present invention>
In the electric work vehicle according to the fourth aspect of the present invention, in the third aspect of the present invention described above, the charge control unit is configured to supply a voltage when there is a voltage difference between the first battery and the second battery. You may charge from the thing with low.

  When there is a voltage difference between the first battery and the second battery at the start of charging of the first battery and the second battery, the electric work vehicle according to this aspect can equalize both voltages by charging from the lowest voltage. Thereby, according to the 4th aspect of this invention, after making the voltage of a 1st battery and a 2nd battery equal, both batteries can be charged simultaneously in parallel.

<Fifth aspect of the present invention>
In the electric work vehicle according to the fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention described above, when the SOC of the first battery is equal to or lower than a predetermined first threshold value, The relay circuit may be connected and power may be supplied from the second battery to the first battery.

  The electric work vehicle according to this aspect charges the first battery with the electric power supplied from the second battery by controlling the relay circuit when the SOC of the first battery becomes equal to or lower than a predetermined first threshold value. Thus, according to the fifth aspect of the present invention, even if the SOC of the first battery is depleted, if the SOC of the second battery has a margin, the electric work vehicle continues to travel by power interchange control. can do.

<Sixth aspect of the present invention>
In the electric work vehicle according to the sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention described above, when the SOC of the second battery is equal to or lower than a predetermined second threshold value, The relay circuit may be connected and power may be supplied from the first battery to the second battery.

  When the SOC of the second battery becomes equal to or lower than the predetermined second threshold value, the electric work vehicle according to this aspect controls the relay circuit to charge the second battery with the power supplied by the first battery. Thus, according to the sixth aspect of the present invention, even when the SOC of the second battery is depleted, if the SOC of the first battery is sufficient, the driving of the work device is continued by the power interchange control. be able to.

<Seventh aspect of the present invention>
In the electrically powered work vehicle according to a seventh aspect of the present invention, in any one of the first to sixth aspects of the present invention described above, the bodywork is separated from the second battery even when the vehicle body is keyed off. Electric power may be supplied to the second motor to continue driving the working device.

  The electric work vehicle according to this aspect can supply electric power to the second motor by the second battery as an electric power supply source independent of the vehicle body. Thus, according to the seventh aspect of the present invention, it is possible to continue driving the working device even when the vehicle body is key-off.

<Eighth aspect of the present invention>
In the electric work vehicle according to an eighth aspect of the present invention, in any one of the first to seventh aspects of the present invention described above, the relay control unit is connected to the relay circuit when the vehicle body is stopped. In addition, power may be supplied from the first battery to the second battery.

  In the electric work vehicle according to this aspect, the relay control unit controls the relay circuit so that the first battery and the second battery are electrically connected when the vehicle body is stopped. Thereby, according to the 8th aspect of this invention, the 2nd battery can be charged with the electric power which a 1st battery supplies, and in electric work vehicle, 2nd size reduction and space saving with little charge capacity were carried out. A battery can be employed.

1 is an overall configuration diagram schematically showing an electric work vehicle according to the present invention. It is a block diagram of the vehicle body and bodywork with which an electric work vehicle is provided. It is a block diagram which shows the electric power path | route at the time of driving | running | working of an electrically-driven work vehicle. It is a block diagram which shows the electric power path | route at the time of charge of an electrically-driven work vehicle. It is a block diagram which shows the electric power path | route at the time of the electric power accommodation of an electrically-driven work vehicle. It is a block diagram which shows the electric power path | route at the time of key-off of an electrically-driven work vehicle.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the content demonstrated below, In the range which does not change the summary, it can change arbitrarily and can implement. In addition, the drawings used for the description of the embodiments schematically show constituent members, and are partially emphasized, enlarged, reduced, or omitted to deepen the understanding. In some cases, the scale, shape, and the like are not accurately represented.

  FIG. 1 is an overall configuration diagram schematically showing an electric work vehicle 1 according to the present invention. The electric work vehicle 1 is an electric vehicle including a vehicle body 2 as a traveling component and a body 3 mounted on the vehicle body 2, and is a work vehicle that performs a predetermined work. Here, although the electric work vehicle 1 will be described as a refrigerated vehicle in the present embodiment, it is another work vehicle such as a garbage vehicle, a dump vehicle, a mixer vehicle, a fire fighting vehicle, a crane vehicle, or a garbage truck. There may be.

  The vehicle body 2 includes a chassis frame 20, a cab 21, wheels 22, a first battery 23, a power distribution unit 24, a first inverter 25, and a first motor 26.

  The chassis frame 20 is a frame that supports other heavy objects mounted on the vehicle body 2 in addition to the bodywork 3 and the cab 21. The cab 21 is a structure including a driver's seat and the like, and is provided at the front of the chassis frame 20 in the vehicle length direction. The wheel 22 is a traveling wheel of the electric work vehicle 1 and includes two front wheels and two rear wheels as drive wheels in the present embodiment.

  The first battery 23 is a high-voltage battery that supplies electric power as travel energy of the electric work vehicle 1. In addition to supplying the electric power output from the first battery 23 to the first motor 26 via the first inverter 25, the power distribution unit 24, as will be described in detail later, when the power feeding device is connected to the vehicle body 2, 1 Charging power is supplied to the battery 23.

  The first inverter 25 is a power converter that converts DC power input from the first battery 23 via the power distribution unit 24 into AC power and outputs the AC power to the first motor 26. The first motor 26 is a traveling motor that causes the electric work vehicle 1 to travel by rotating the driving wheels of the wheels 22 in accordance with the AC power input from the first inverter 25.

  The electric work vehicle 1 can travel with the electric power of the first battery 23 as an electric vehicle without an internal combustion engine due to the basic configuration of the vehicle body 2 as described above. The electric work vehicle 1 may include a mechanism that collects regenerative energy from the wheels 22 during deceleration and performs regenerative charging of the first battery 23. The electric work vehicle 1 may be a so-called range extender vehicle including a power generation internal combustion engine that can drive the first motor 26 to generate power.

  The mounting body 3 mounted on the vehicle body 2 at the rear portion in the vehicle length direction of the chassis frame 20 includes a second battery 30, a second inverter 31, a second motor 32, and a work device 33.

  The second battery 30 is a battery that supplies electric power necessary for performing a predetermined work in the bodywork 3. The second inverter 31 is a power conversion device that converts DC power input from the second battery 30 into AC power and outputs the AC power to the second motor 32. Although not shown, when the second motor 32 is a DC motor, the second inverter 31 is not necessary, and the DC power from the second battery 30 is directly supplied to the second motor 32.

  The second motor 32 is a working motor that rotates according to the AC power input from the second inverter 31, and is an operating power source such as a hydraulic pump and a compressor included in the working device 33. In the present embodiment, the working device 33 is a refrigeration device including a compressor driven by the second motor 32, for example.

  The electric work vehicle 1 drives the work device 33 with the electric power of the second battery 30 independent of the first battery 23, depending on the use state of the first battery 23, with the basic configuration as described above of the bodywork 3. First, a predetermined work, that is, in the present embodiment, the load can be frozen.

  Next, a more detailed configuration of the vehicle body 2 and the bodywork 3 of the electric work vehicle 1 will be described. FIG. 2 is a block diagram of the vehicle body 2 and the bodywork 3 provided in the electric work vehicle 1.

  The vehicle body 2 includes a VCU 27 and an ignition key 28 in addition to the configuration described above. The VCU 27 includes an input / output device (not shown), a storage device (ROM, RAM, etc.) used for storing control programs, a central processing unit (CPU), a timer counter, and the like, a travel mechanism, a communication device, and various electrical components. It is a vehicle control unit (Vehicle Control Unit) which carries out the integrated control of the controlled object in the vehicle bodies 2, such as. The ignition key 28 is a switch operated by the driver of the electric work vehicle 1 in order to switch between the traveling mode and the standby mode of the electric work vehicle 1, and can control ON / OFF of the VCU 27 in conjunction with this.

  The power distribution unit 24 of the vehicle body 2 further includes a socket 40, a charging port 41, a relay circuit 42, a relay control unit 43, and a charging control unit 44.

  The socket 40 is a connecting portion provided in the vehicle body 2 so that electric power can be exchanged between the vehicle body 2 and the bodywork 3. The charging port 41 is a connecting portion provided in the vehicle body 2 so as to be connected to the external power feeding device 5 as a so-called charging stand when the first battery 23 and the second battery 30 are charged.

  The relay circuit 42 relays power transmission / reception between the first battery 23 and the first inverter 25, and is electrically connected to the bodywork 3 via the socket 40, so that the relay circuit 42 is externally connected via the charging port 41. The charging power supplied from the power supply device 5 is supplied to the first inverter 25 and the second battery 30. Here, the relay circuit 42 is configured to be electrically connectable and disconnectable in each of the conductive path with the first battery 23 and the conductive path with the second battery 30.

  The relay control unit 43 controls the connection / disconnection state of the relay circuit 42 in accordance with the operation state of the electric work vehicle 1 and manages the electric power exchanged via the relay circuit 42. Here, although the relay control part 43 is arrange | positioned inside the power distribution unit 24 in this embodiment, you may comprise as one module of VCU27.

  The charging control unit 44 controls the connection / disconnection state of the relay circuit 42 via the relay control unit 43 when the external power feeding device 5 is connected to the charging port 41 of the vehicle body 2, and the first battery 23 and the second battery 30 is charged. At this time, the charge control unit 44 monitors the SOC (State Of Charge), which is the ratio of the charge amount to the charge capacity of the first battery 23 and the second battery 30, and performs charge according to the procedure according to the SOC described later in detail. Execute control. Here, the charging control unit 44 is disposed inside the power distribution unit 24 in the present embodiment, but may be configured as one module of the VCU 27.

  The bodywork 3 includes a plug 34 and a work control unit 35 in addition to the configuration described above. The plug 34 is a connecting portion provided on the body 3 so that it can be connected to the socket 40 when power is exchanged between the vehicle body 2 and the body 3. The work control unit 35 includes, for example, a known microcomputer control circuit. In the present embodiment, the operation of the second motor 32 is performed by monitoring the temperature of the refrigerator in the work device 33 and sending a control signal to the second inverter 31. It is a controller that controls and adjusts the temperature of the refrigerator.

  Next, energy management of the electric work vehicle 1 will be described. FIG. 3 is a block diagram showing a power path when the electric work vehicle 1 is traveling.

  The VCU 27 performs driving control of the electric work vehicle 1 by controlling each component of the vehicle body 2 by processing a driving operation by the driver and various information of the vehicle body 2. For example, the VCU 27 outputs a control signal to the relay control unit 43 so that the relay circuit 42 electrically connects the first battery 23 and the first inverter 25. As a result, the vehicle body 2 can travel when electric power is supplied from the first battery 23 to the first motor 26, as indicated by a dashed arrow P1 in FIG.

  Further, in the bodywork 3 mounted on the vehicle body 2, the work control unit 35 controls the second inverter 31 according to the electric power necessary for the management of the refrigerator in the work device 33, whereby the broken line in FIG. 3. As indicated by the arrow P2, power is supplied from the second battery 30 to the second motor 32.

  At this time, the relay control unit 43 controls the relay circuit 42 so that the first battery 23 of the vehicle body 2 and the second battery 30 of the bodywork 3 are in an electrically disconnected state. That is, the first battery 23 and the second battery 30 are electrically disconnected from each other when the electric work vehicle 1 travels, and become independent power supply sources in the vehicle body 2 and the bodywork 3 respectively. . Therefore, the electric work vehicle 1 does not require coordinated control of the electric power of the first battery 23 and the second battery 30 during traveling, and can simplify energy management.

  Next, charging control of each battery will be described as one of energy management of the electric work vehicle 1. FIG. 4 is a block diagram showing a power path during charging of the electric work vehicle 1.

  When the charging control unit 44 detects that the external power supply device 5 is connected to the charging port 41, the charging control unit 44 starts charging control of the first battery 23 and the second battery 30. When the charge control is started, the charge control unit 44 acquires the voltages of the first battery 23 and the second battery 30, and when there is a voltage difference between the two, the low voltage battery and the relay circuit 42 Are electrically connected, and the battery having a high voltage and the relay circuit 42 are electrically disconnected. Thereby, the charge control unit 44 starts charging from a battery having a low voltage.

  Further, when the voltages of the first battery 23 and the second battery 30 become equal, the charging control unit 44 electrically connects each battery and the relay circuit 42, and the broken line arrows P3 and P4 in FIG. As shown in the diagram, both batteries are charged in parallel. Thus, the electric work vehicle 1 can collectively charge the work second battery 30 together with the traveling first battery 23 when charging. In addition, the charge control part 44 electrically disconnects the 2nd battery 30 and the relay circuit 42, when it detects the full charge state of the 2nd battery 30, and charges until the 1st battery 23 will be in a full charge state. continue.

  Next, power interchange control of each battery will be described as one of energy management of the electric work vehicle 1. FIG. 5 is a block diagram showing a power path when the electric work vehicle 1 is powered. Here, the power interchange control is executed in an emergency such as when the electric work vehicle 1 cannot travel due to a decrease in the SOC of the first battery 23 or when the work device 33 cannot be driven due to a decrease in the SOC of the second battery 30. Control.

  As described above, the electric work vehicle 1 functions as a power supply source independent of each other when the first battery 23 and the second battery 30 are electrically disconnected during traveling. Here, the VCU 27 performs power interchange control when the electric work vehicle 1 is stopped when the SOC of the first battery 23 is equal to or lower than a predetermined first threshold value, as indicated by a broken line arrow P5 in FIG. In addition, control for accommodating power from the second battery 30 to the first battery 23 is performed.

  More specifically, when the VCU 27 detects that the SOC of the first battery 23 has become equal to or lower than the first threshold value, the VCU 27 confirms that the electric work vehicle 1 is stopped, and the first through the relay circuit 42. A control signal is output to the relay control unit 43 so that the battery 23 and the second battery 30 are electrically connected. As a result, a conductive path is formed between the first battery 23 and the second battery 30, and power is supplied from the second battery 30. As a result, even if the SOC of the first battery 23 is exhausted, the electric work vehicle 1 can continue traveling by the power interchange control if the SOC of the second battery 30 is sufficient.

  The first threshold value of the first battery 23 can be set as the lower limit value of the SOC at which the electric work vehicle 1 cannot travel. The first threshold value may be arbitrarily set as the SOC required for traveling a predetermined distance.

  Further, the VCU 27 performs power interchange control when the electric work vehicle 1 is stopped when the SOC of the second battery 30 is equal to or lower than a predetermined second threshold, as indicated by a broken line arrow P6 in FIG. Then, control is performed so that power is interchanged from the first battery 23 to the second battery 30.

  More specifically, when the VCU 27 detects that the SOC of the second battery 30 is equal to or lower than the second threshold value via the charge control unit 44, the VCU 27 confirms that the electric work vehicle 1 is stopped, and the relay A control signal is output to the relay control unit 43 so that the first battery 23 and the second battery 30 are electrically connected via the circuit 42. As a result, a conductive path is formed between the second battery 30 and the first battery 23, and power is supplied from the first battery 23. Thus, even when the SOC of the second battery 30 is exhausted, the electric work vehicle 1 can continue to drive the work device 33 by the power interchange control if the SOC of the first battery 23 is sufficient. .

  Note that the second threshold value of the second battery 30 can be set as the lower limit value of the SOC at which the working device 33 cannot be driven. Further, the second threshold value may be arbitrarily set as the SOC required for continuing to drive the work device 33 for a predetermined duration.

  Next, power control at the time of key-off will be described as one of energy management of the electric work vehicle 1. FIG. 6 is a block diagram showing a power path when the electric work vehicle 1 is keyed off.

  The electric work vehicle 1 turns off the VCU 27 and stops the operation of the vehicle body 2 when the ignition key 28 is switched off by the driver during parking. On the other hand, the bodywork 3 can supply power to the second motor 32 by a second battery as a power supply source independent of the vehicle body 2 as indicated by a broken line arrow P7 in FIG. For this reason, the working device 33 can continue the temperature adjustment of the refrigerator even when the vehicle body 2 is keyed off.

  In addition, when the ignition key 28 is switched off when the electric work vehicle 1 is parked, the electric work vehicle 1 temporarily maintains a part of the components of the vehicle body 2 in an exceptionally on state so that the first battery 23 You may perform control which accommodates electric power to the 2nd battery 30. FIG. More specifically, in the electric work vehicle 1, when the ignition key 28 is switched off, the relay control unit 43 is connected to the relay circuit 42 so that the first battery 23 and the second battery 30 are electrically connected. To control. And the charging control part 44 charges the 2nd battery 30 by performing control which supplies electric power from the 1st battery 23 to the 2nd battery 30, as shown by the broken line arrow P8 of FIG. Thereby, since the electric work vehicle 1 can suppress the charging capacity required for the second battery 30, the second battery 30 can be reduced in size and space.

  As described above, the electric work vehicle 1 according to the present invention supplies the electric power necessary for traveling of the vehicle body 2 from the first battery 23 and also supplies the electric power necessary for driving the work device 33 in the body 3 to the second. The battery 30 is supplied from the battery 30 and the relay circuit 42 disconnects the electrical connection between the first battery 23 and the second battery 30 during traveling. As a result, the electric work vehicle 1 can control the vehicle body 2 and the bodywork 3 with independent power systems when traveling, so that cooperative control between the first battery 23 and the second battery 30 is unnecessary. It becomes. In addition, since the vehicle body 2 and the bodywork 3 are electrically independent from each other when the electric work vehicle 1 is traveling, the high-voltage first battery 23 for traveling is electrically connected to the bodywork 3 from the body 3. Can be cut into pieces. As a result, the electric work vehicle 1 does not require the second battery 30 to have the level of safety required for the high-voltage first battery 23. Therefore, according to the electric work vehicle 1 according to the present invention, it is possible to prevent the energy management of the battery from becoming complicated and to easily respond to a high safety requirement.

  In the electric work vehicle 1 according to the present invention, the work control unit 35 is provided in the bodywork 3 and the relay circuit 42 and the relay control unit 43 are provided in the vehicle body 2. The vehicle body 2 and the bodywork 3 can be configured independently on the surface. Therefore, according to the electric work vehicle 1 according to the present invention, it is possible to have a simple configuration in which the components for traveling are gathered in the vehicle body 2 and the components for work are gathered in the body 3. Manufacturing costs can be reduced by simplifying the design.

  Further, in the electric work vehicle 1 according to the present invention, when the external power feeding device 5 is connected to the vehicle body 2 at the charging port 41, the charging control unit 44 controls the relay circuit 42, so that the external power feeding device 5 Charging power is supplied to both the first battery 23 and the second battery 30. Therefore, according to the electric work vehicle 1 according to the present invention, the first battery 23 and the second battery 30 are independent power supply sources, but the first battery 23 for traveling is charged together with this. The working second battery 30 can be charged together.

  Moreover, the electric work vehicle 1 which concerns on this invention is charged from the thing with a low voltage, when there exists a voltage difference in both at the time of the charge start of the 1st battery 23 and the 2nd battery 30. FIG. Therefore, according to the electric work vehicle 1 according to the present invention, both batteries can be simultaneously charged in parallel after the voltages of the first battery 23 and the second battery 30 become equal.

  The electric work vehicle 1 according to the present invention controls the relay circuit 42 to supply power from the second battery 30 to the first battery 23 when the SOC of the first battery 23 is equal to or lower than the predetermined first threshold value. Supply. Therefore, according to the electric work vehicle 1 according to the present invention, even when the SOC of the first battery 23 is depleted, if the SOC of the second battery 30 has a margin, the traveling is continued by the power interchange control. Can do.

  Further, the electric work vehicle 1 according to the present invention controls the relay circuit 42 to supply power from the first battery 23 to the second battery 30 when the SOC of the second battery 30 is equal to or lower than a predetermined second threshold value. Supply. Therefore, according to the electric work vehicle 1 according to the present invention, even if the SOC of the second battery 30 is depleted, if the SOC of the first battery 23 is sufficient, the drive of the work device 33 is performed by power interchange control. Can continue.

  In addition, since the electric work vehicle 1 according to the present invention can supply power to the second motor 32 by the second battery 30 as an independent power supply source for the vehicle body 2, even when the vehicle body 2 is keyed off. The drive of the working device 33 can be continued.

  In addition, the electric work vehicle 1 according to the present invention controls the relay circuit 42 so that the first battery 23 and the second battery 30 are electrically connected when the vehicle body 2 is keyed off, thereby the first battery 23. The second battery 30 can be charged with the electric power supplied by the second battery 30, and the second battery 30 with a small charge capacity and a reduced size and space can be employed.

DESCRIPTION OF SYMBOLS 1 Electric work vehicle 2 Car body 3 Bodywork 23 1st battery 24 Power distribution unit 26 1st motor 30 2nd battery 32 2nd motor 33 Work apparatus 42 Relay circuit 43 Relay control part

Claims (8)

An electric work vehicle that travels with a first motor supplied with electric power from a first battery and performs a predetermined work with a second motor supplied with electric power from a second battery,
A vehicle body including a power distribution unit that supplies the first motor with electric power output from the first battery, the first motor, and the first battery;
A work body driven by the second battery, the second motor, and the second motor, and a body mounted on the vehicle body;
A relay circuit for electrically connecting the second battery to the power distribution unit;
A relay control unit for controlling the connection / disconnection state of the relay circuit,
The relay control unit electrically cuts off the power distribution unit and the second battery during travel of the vehicle body.   The electric work vehicle according to claim 1, wherein a work control unit that controls the bodywork is provided in the bodywork, and the relay circuit and the relay control unit are provided in the vehicle body. A charge control unit for controlling charging of the first battery and the second battery;
The charging control unit controls the relay circuit to supply charging power from the external power supply device to the first battery and the second battery when the external power supply device is connected to the vehicle body. The electric work vehicle according to 1 or 2.   The electric work vehicle according to claim 3, wherein the charge control unit charges the battery from a low voltage when there is a voltage difference between the first battery and the second battery.   5. The device according to claim 1, wherein when the SOC of the first battery becomes equal to or lower than a predetermined first threshold value, the relay circuit is set in a connected state and power is supplied from the second battery to the first battery. The electric work vehicle described in 1.   6. The device according to claim 1, wherein when the SOC of the second battery becomes equal to or lower than a predetermined second threshold value, the relay circuit is set in a connected state and power is supplied from the first battery to the second battery. The electric work vehicle described in 1.   The electric body according to any one of claims 1 to 6, wherein the body continues to drive the work device by supplying electric power from the second battery to the second motor even when the vehicle body is keyed off. Work vehicle.   The electric work vehicle according to claim 1, wherein the relay control unit sets the relay circuit in a connected state when the vehicle body is stopped, and supplies electric power from the first battery to the second battery. .

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