Work vehicle

Abstract

Provided is a work vehicle capable of having improved vehicular weight balance.　A work vehicle (1) comprises: a vehicle body (2); a left traveling unit (25L) including a left traveling device (3L) disposed on the left side of the vehicle body; a right traveling unit (25R) including a right traveling device (3R) disposed on the right side of the vehicle body; and a plurality of batteries (7) capable of storing electric power for driving the left traveling unit and the right traveling unit. At least one from among the plurality of batteries is disposed on one of the left traveling unit and the right traveling unit.

Description

Work vehicles

[0001] The present invention relates to a work vehicle for performing work such as agricultural work.

[0002] A known work vehicle is disclosed in Patent Document 1. The work vehicle disclosed in Patent Document 1 includes a battery, a transmission device, and a vehicle frame. The battery is supported on a chassis that includes the vehicle frame and the transmission device.

[0003] Japanese Patent Publication No. 2023-66726

[0004] The above-described work vehicle has the battery supported on the chassis, which allows it to firmly support the heavy battery. However, because the weight of the battery is concentrated in the vehicle body (traveling body) including the chassis, there is room for improvement in the vehicle weight balance, including reducing the weight of the vehicle body.

[0005] The present invention has been made in consideration of the above problems, and has an object to provide a work vehicle that can improve the weight balance of the vehicle.

[0006] A work vehicle according to one embodiment of the present invention comprises a vehicle body, a left running section including a left running device arranged on the left side of the vehicle body, a right running section including a right running device arranged on the right side of the vehicle body, and a plurality of batteries capable of storing electricity for driving the left running section and the right running section, at least one of the plurality of batteries being arranged in either the left running section or the right running section.

[0007] The plurality of batteries may include a first battery used when driving or working, and a second battery used when driving or working, the first battery being arranged in the vehicle body, and the second battery having the same function as the first battery and being arranged in at least one of the left running section and the right running section.

[0008] The plurality of batteries may include a first battery used when driving or working, and a second battery used when driving or working, the first battery and the second battery having the same function, the first battery being arranged in the left running section, and the second battery being arranged in the right running section.

[0009] The plurality of batteries may not be disposed on the vehicle body.

[0010] The second battery may be disposed in the left traveling section and the right traveling section.

[0011] The second battery may be disposed below at least one of the left traveling section and the right traveling section.

[0012] The second battery may be disposed below the left traveling section and below the right traveling section.

[0013] The left traveling section may include a left front wheel and a left rear wheel, the right traveling section may include a right front wheel and a right rear wheel, and the second battery may be disposed between the left front wheel and the left rear wheel or between the right front wheel and the right rear wheel.

[0014] The left traveling section may include a left front wheel and a left rear wheel, the right traveling section may include a right front wheel and a right rear wheel, and the second battery may be disposed between the left front wheel and the left rear wheel and between the right front wheel and the right rear wheel.

[0015] The work vehicle may include a lifting mechanism that raises and lowers the vehicle body, and the lifting mechanism may raise and lower the first battery together with the vehicle body.

[0016] The work vehicle may be equipped with a motor that generates power required for traveling or working, and the first battery and the second battery may be batteries that store the power supplied to the motor.

[0017] According to the work vehicle of the present invention, the weight balance of the vehicle can be improved.

[0018] 1 is a left side view showing an embodiment of a work vehicle. FIG. 2 is a right side view showing an embodiment of a work vehicle. FIG. 3 is a front view showing an embodiment of a work vehicle. FIG. 4 is a rear view showing an embodiment of a work vehicle. FIG. 5 is a plan view showing an embodiment of a work vehicle. FIG. 6 is a perspective view showing an embodiment of a work vehicle. FIG. 7 is a block diagram showing an example of the overall configuration of a work vehicle. FIG. 8 is a perspective view showing an example of the overall configuration of a work vehicle. FIG. 9 is a perspective view showing an example of the overall configuration of a work vehicle. FIG. 10 is a perspective view showing an example of the overall configuration of a work vehicle. FIG. 11 is a perspective view showing an example of the overall configuration of a work vehicle. FIG. 12 is a perspective view showing an example of the overall configuration of a work vehicle. FIG. 13 is a perspective view showing an example of the overall configuration of a work vehicle. Fig. 10 is a front view showing the positional relationship between the first battery and the second battery when the vehicle body is at a second height.Fig. 11 is a front view showing an embodiment in which no battery is disposed in the vehicle.

[0019] A preferred embodiment of a work vehicle 1 according to the present invention will now be described. Figures 1 to 7 are diagrams showing one embodiment of the work vehicle 1. Figure 1 is a left side view of the work vehicle 1. Figure 2 is a right side view of the work vehicle 1. Figure 3 is a front view of the work vehicle 1. Figure 4 is a rear view of the work vehicle 1. Figure 5 is a plan view of the work vehicle 1. Figure 6 is a perspective view of the work vehicle 1. Figure 7 is a block diagram showing the overall configuration of the work vehicle 1.

[0020] In the following description, the direction indicated by arrow X1 in the drawings is referred to as the forward direction, the direction indicated by arrow X2 as the backward direction, the direction indicated by arrow Y1 as the left direction, the direction indicated by arrow Y2 as the right direction, the direction indicated by arrow Z1 as the upward direction, and the direction indicated by arrow Z2 as the downward direction. In addition, the direction indicated by arrow X3 is referred to as the forward / backward direction, the direction indicated by arrow Y3 as the left / right direction, and the direction indicated by arrow Z3 as the up / down direction.

[0021] Examples of work performed by the work vehicle 1 include, but are not limited to, agricultural work, industrial (civil engineering, construction, etc.) work, and transportation work. In a preferred embodiment of the present invention, the work performed by the work vehicle 1 is agricultural work (farm work). Below, an example will be described in which the work performed by the work vehicle 1 is farm work. In this case, the work vehicle 1 is an agricultural work vehicle.

[0022] As shown in Figures 1 to 6, the work vehicle 1 includes a vehicle body 2 and a traveling device 3 that supports the vehicle body 2 so that it can travel. In this embodiment, the vehicle body 2 is formed in a substantially rectangular parallelepiped shape with an internal space. However, the shape of the vehicle body 2 is not limited to a substantially rectangular parallelepiped shape. The internal space of the vehicle body 2 houses various devices and equipment.

[0023] As shown in Figures 1 and 2, a power unit 4 for driving the traveling device 3 is mounted (housed) in the interior space of the vehicle body 2. The power unit 4 generates power for driving the traveling device 3, and the power is supplied to the traveling device 3. As shown in Figure 7, the power unit 4 includes a motor 5 and a battery 7. In the present embodiment, the vehicle body 2 mounts (houses) the battery 7 as the power unit 4.

[0024] The work vehicle 1 is equipped with a plurality of batteries 7. The plurality of batteries 7 includes batteries 7 (shown by dashed lines) arranged in the vehicle body 2 and batteries 7 (shown by solid lines) arranged in a position different from the vehicle body 2. The batteries 7 arranged in the vehicle body 2 are an example of a first battery 35, which will be described later. The batteries 7 arranged in a position different from the vehicle body 2 are an example of a second battery 36, which will be described later. The first battery 35 and the second battery 36 will be described in detail later.

[0025] The motor 5 is a traveling system motor that generates power to drive the traveling device 3. The motor 5 is an electric motor that is driven by electricity. An inverter 23 (see FIG. 7) is connected to the motor 5. The inverter 23 controls the rotation of the motor 5 based on a control signal from a control device 15, which will be described later. The battery 7 stores the power supplied to the motor 5. However, the power device 4 may include an engine instead of the motor 5. The power device 4 may also include a fuel cell.

[0026] As shown in FIG. 7 , the work vehicle 1 is equipped with a motor 5, which is a traveling motor, and a motor 6, which is a working motor. The working motor generates power to drive devices and mechanisms other than the traveling device 3. The motor 6 is an electric motor that is driven by power supplied from a battery 7. The rotation of the motor 6 can be controlled by an inverter 23. Hereinafter, the motor 5 may be referred to as the "traveling motor 5," and the motor 6 may be referred to as the "working motor 6."

[0027] The motors (traveling motor 5, working motor 6) can be mounted on the vehicle body 2. The traveling motor 5 and working motor 6 can be driven independently of each other. The working motor 6 is a motor for driving a hydraulic pump that operates a hydraulic cylinder, which will be described later. The working motor 6 also drives the external output shaft 8.

[0028] The work system motor 6 may be a hydraulic motor. The hydraulic motor is driven by hydraulic oil supplied from a hydraulic pump. In this case, for example, the hydraulic pump is driven by the travel system motor 5, the hydraulic oil supplied from the hydraulic pump drives the hydraulic motor (work system motor 6), and the external output shaft is driven by the hydraulic motor. Furthermore, the work vehicle 1 may be equipped with a work system motor 6 that is a hydraulic motor in addition to the work system motor 6 that is an electric motor.

[0029] As described above, the battery 7, which is part of the power unit 4, is housed in the vehicle body 2 (see FIGS. 1 and 2). Although not shown, the vehicle body 2 also houses a cooling system (radiator, fan, water pump, compressor, etc.) that cools the power unit 4 (motor 5, motor 6, battery 7, etc.), and a hydraulic system (control valves, etc.) that actuates hydraulic cylinders (cylinder 62, left cylinder 81L, right cylinder 81R, lift cylinder 91), etc., which will be described later, based on control signals from the control device 15.

[0030] As shown in FIG. 1 , the external output shaft 8 protrudes rearward from the rear of the vehicle body 2. The external output shaft 8 is an output shaft for extracting the power of the work motor 6 to the outside of the vehicle body 2. The external output shaft 8 is, for example, a PTO shaft. The power extracted from the external output shaft 8 is input to a work implement 200 for performing work. This drives the work implement 200 to perform work.

[0031] Examples of the working device 200 include, but are not limited to, devices that perform agricultural work (farm work), devices that perform civil engineering work, devices that perform construction work, devices that perform transportation work, etc. In the embodiment described below, the working device 200 is a device that performs farm work.

[0032] Examples of the working device 200 for performing agricultural work include a spraying device for spreading fertilizer, chemicals, and other spray materials, a sowing device for sowing seeds, a tilling device for tilling the soil, a tilling device (plow) for tilling the soil, a weeding device for weeding, and a soil-piling device for piling up soil. However, the type of working device 200 is not particularly limited as long as it is a device for performing agricultural work. Furthermore, if the working device 200 is an electrically powered working device, it may be driven by power extracted from the battery 7 via a power line to the outside of the vehicle body 2, instead of being driven by power extracted from the external output shaft 8.

[0033] The vehicle body 2 is capable of traveling by being driven by the traveling devices 3. As shown in FIGS. 3 and 4 , the traveling devices 3 include a left traveling device 3L provided on the left side of the vehicle body 2 and a right traveling device 3R provided on the right side of the vehicle body 2. The vehicle body 2 is located between the left traveling device 3L and the right traveling device 3R. As shown in FIG. 1 , the left traveling device 3L includes a left front wheel 3LF and a left rear wheel 3LB. As shown in FIG. 2 , the right traveling device 3R includes a right front wheel 3RF and a right rear wheel 3RB. Hereinafter, for convenience of explanation, the left front wheel 3LF, the right front wheel 3RF, the left rear wheel 3LB, and the right rear wheel 3RB may be collectively referred to as "wheels 30."

[0034] The wheels 30 (left front wheel 3LF, right front wheel 3RF, left rear wheel 3LB, right rear wheel 3RB) are arranged on the sides of the vehicle body 2. The left front wheel 3LF and the left rear wheel 3LB are arranged on the left side of the vehicle body 2. The right front wheel 3RF and the right rear wheel 3RB are arranged on the right side of the vehicle body 2. In the case of the work vehicle 1 of this embodiment, the size (diameter and width) of the rear wheels (left rear wheel 3LB, right rear wheel 3RB) is larger than the size (diameter and width) of the front wheels (left front wheel 3LF, right front wheel 3RF). However, the size of the front wheels (left front wheel 3LF, right front wheel 3RF) and the size of the rear wheels (left rear wheel 3LB, right rear wheel 3RB) may be the same, or the size of the front wheels may be larger than the size of the rear wheels.

[0035] In this embodiment, the traveling device 3 is a wheel-type traveling device in which the front wheels (left front wheel 3LF, right front wheel 3RF) and rear wheels (left rear wheel 3LB, right rear wheel 3RB) are all tires. However, the traveling device 3 may be a crawler-type traveling device in which the left traveling device 3L and the right traveling device 3R are crawlers, or the traveling device 3 may be a traveling device in which one of the front wheels or the rear wheels is a wheel and the other is a crawler.

[0036] 1, 2, and 6, the work vehicle 1 is equipped with a fender 55L that covers the upper and front of the left rear wheel 3LB, and a fender 55R that covers the upper and front of the right rear wheel 3RB. The fender 55L is attached to a first connector 19L3 (see FIG. 8) of the frame structure 18, which will be described later. The fender 55R is attached to a first connector 21R3 (see FIG. 8) of the frame structure 18, which will be described later. Although not shown, the work vehicle 1 may also be equipped with fenders that cover the front wheels (left front wheel 3LF, right front wheel 3RF).

[0037] As shown in Figure 7, the work vehicle 1 is equipped with a transmission 9. The transmission 9 is capable of switching the propulsion force of the traveling device 3 by changing gears. The transmission 9 is also capable of switching between forward and reverse travel of the traveling device 3. The transmission 9 may be equipped with a speed change clutch that can switch between a four-wheel drive state (4WD) in which all four wheels (left front wheel 3LF, right front wheel 3RF, left rear wheel 3LB, right rear wheel 3RB) are driven, and a two-wheel drive state (2WD) in which only the rear wheels (left rear wheel 3LB, right rear wheel 3RB) or only the front wheels (left front wheel 3LF, right front wheel 3RF) are driven.

[0038] As shown in Figures 1, 2, 4, and 5, the work vehicle 1 is equipped with a mounting unit 10 to which a work device 200 for performing the above-mentioned work is attached. The work device 200 is detachably attached to the mounting unit 10. The mounting unit 10 is provided at the rear of the vehicle body 2. Figure 4 is a view of the mounting unit 10 as seen from the rear. However, the mounting unit 10 may also be provided at the front or side (left or right) of the vehicle body 2.

[0039] The mounting part 10 is composed of a three-point link mechanism. Specifically, as shown in FIG. 4, the mounting part 10 has a lift arm 10a, a lower link 10b, a top link 10c, a lift rod 10d, and a lift cylinder 10e. The front end of the lift arm 10a is supported on the upper rear part of the vehicle body 2 so that it can swing upward or downward. The lift arm 10a swings (lifts and lowers) by driving the lift cylinder 10e. The lift cylinder 10e is composed of a hydraulic cylinder. The lift cylinder 10e is connected to a hydraulic pump (not shown) via a control valve (not shown).

[0040] The hydraulic pump is driven by the work system motor 6. The control valve is an electromagnetic valve or the like whose flow path is controlled to open or close by the control device 15. The flow of hydraulic oil discharged from the hydraulic pump is controlled by the control valve, thereby allowing the lift cylinder 10e to extend or retract.

[0041] The front end of the lower link 10b is supported on the rear lower part of the vehicle body 2 so as to be able to swing upward or downward. The front end of the top link 10c is supported on the rear part of the vehicle body 2 above the lower link 10b so as to be able to swing upward or downward. A lift rod 10d connects the lift arm 10a to the lower link 10b. A working device 200 is connected to the rear part of the lower link 10b and the rear part of the top link 10c. When the lift cylinder 10e is driven (extends and retracts), the lift arm 10a rises and falls, and the lower link 10b, which is connected to the lift arm 10a via the lift rod 10d, rises and falls. As a result, the working device 200 swings upward or downward (lifts and falls) around the front part of the lower link 10b as a fulcrum.

[0042] The work device 200 attached to the attachment unit 10 is towed and moved by the work vehicle 1 as the work vehicle 1 travels. Note that instead of the work device 200, a cart or the like for transporting agricultural produce or the like may be attached to the attachment unit 10. The attachment unit 10 may also be provided in a part other than the rear of the vehicle body 2 (for example, the front or side). The work device 200 may be placed on top of the work vehicle 1 instead of being attached to the attachment unit 10. In this case, the work device 200 moves while being placed on top of the work vehicle 1 as the work vehicle 1 travels.

[0043] 7, the work vehicle 1 is equipped with a positioning device 11. The positioning device 11 can detect the position of the vehicle body 2 (positioning information including latitude and longitude) using a satellite positioning system (positioning satellite) such as D-GPS, GPS, GLONASS, Beidou, Galileo, or Michibiki. That is, the positioning device 11 receives satellite signals (position of the positioning satellite, transmission time, correction information, etc.) transmitted from the positioning satellites, and detects the position of the vehicle body 2 (for example, latitude and longitude) based on the satellite signals.

[0044] The positioning device 11 has a receiving device 12 and an inertial measurement unit (IMU) 13. The receiving device 12 has an antenna and the like and is a device that receives satellite signals transmitted from positioning satellites, and is attached to the vehicle body 2. The inertial measurement unit 13 has an acceleration sensor that detects acceleration, a gyro sensor that detects angular velocity, and the like. The inertial measurement unit 13 is attached to the vehicle body 2. The inertial measurement unit 13 can detect the roll angle, pitch angle, yaw angle, etc. of the vehicle body 2. Note that the yaw angle may be detected by installing multiple positioning devices 11.

[0045] As shown in FIG. 7 , the work vehicle 1 is equipped with a communication device 14. The communication device 14 includes a communication circuit for communicating via an on-board network and a wireless communication circuit for wireless communication. The wireless communication circuit can directly or indirectly communicate wirelessly with an external device using communication standards such as IEEE 802.11 series Wi-Fi (Wireless Fidelity, registered trademark), BLE (Bluetooth (registered trademark) Low Energy), LPWA (Low Power Wide Area), and LPWAN (Low-Power Wide-Area Network). As another example, the communication device 14 may be provided with a communication circuit capable of wirelessly communicating with an external device via, for example, a mobile phone communication network or a data communication network. Examples of external devices include a personal computer, a smartphone, a tablet computer, a PDA, or a server. Examples of external devices include an operation device 101, which will be described later.

[0046] As shown in Fig. 7, the work vehicle 1 is equipped with a control device 15. The control device 15 is a device that performs various controls of the work vehicle 1. The control device 15 is equipped with a calculation unit (CPU, etc.) and a storage unit (RAM, ROM, etc.). The storage unit may include an external memory provided outside the control device 15. The control device 15 is connected to the various devices and mechanisms shown in Fig. 7 via an in-vehicle LAN (on-board network) such as a CAN (Controller Area Network) or a communication line.

[0047] The control device 15 controls the operation of various devices and mechanisms communicably connected to the control device 15 by having the calculation unit execute various control programs stored in the memory unit. The functions of each control unit of the control device 15 (autonomous driving control unit 15A, distance change control unit 15B, height change control unit 15C) described below are realized by having the calculation unit execute predetermined control programs stored in the memory unit.

[0048] As shown in Fig. 7, the control device 15 includes an automatic driving control unit 15A. The automatic driving control unit 15A controls the automatic driving of the work vehicle 1. The automatic driving control unit 15A is capable of executing line-type automatic driving control and autonomous-type automatic driving control. In line-type automatic driving control, the automatic driving control unit 15A controls the operation of the steering mechanism 60, transmission 9, motor 5, etc., which will be described later, so that the work vehicle 1 (vehicle body 2) moves along a predetermined planned driving line.

[0049] In autonomous automatic driving control, the automatic driving control unit 15A sets the direction of travel (steering direction) and vehicle speed (velocity) of the vehicle body 2 based on the results of sensing (detecting objects) around the work vehicle 1 (vehicle body 2) using a positioning device 11, etc., and controls the operation of the steering mechanism 60, transmission 9, motor 5, etc. so that the set steering and vehicle speed are achieved.

[0050] Note that the line-type automatic driving control and the autonomous-type automatic driving control may be switchable using a switch or the like. Also, the automatic driving control unit 15A may be configured to be able to execute either the line-type automatic driving control or the autonomous-type automatic driving control. Note that the configuration of the automatic driving control unit 15A is not limited to the configuration described above.

[0051] The work vehicle 1 can perform automatic driving (unmanned driving) without an operator on board because the control device 15 includes the automatic driving control unit 15A. Therefore, the work vehicle 1 in the illustrated embodiment does not have a driver's seat where an operator sits. However, the work vehicle 1 may also be a vehicle that performs automatic driving with an operator on board. Alternatively, the work vehicle 1 may be a vehicle that is driven and driven by an operator on board. When the work vehicle 1 is a vehicle in which an operator rides, a driver's seat is provided in the vehicle body 2.

[0052] As shown in FIG. 7 , the work vehicle 1 is equipped with a lighting device 16. The lighting device 16 is provided on the vehicle body 2. The lighting device 16 includes at least a headlight that illuminates the area ahead of the vehicle body 2. In addition to the headlight, the lighting device 16 may also include a plurality of work lights that illuminate the area around the vehicle body 2. The work lights can, for example, illuminate the sides (left and right) of the vehicle body 2 or the area behind the vehicle body 2. The lighting device 16 may also include status indicator lights, left and right lights, brake lights, etc.

[0053] As shown in Fig. 7, the work vehicle 1 is equipped with an alarm device 17. The alarm device 17 uses sound, light, etc. to alert people around the vehicle body 2 of danger (such as the approach of the vehicle body 2). The alarm device 17 is composed of a speaker, a warning light, etc.

[0054] As shown in Figures 1 to 6, the work vehicle 1 includes a frame structure 18 that is disposed around the vehicle body 2 and attached to the vehicle body 2. As shown in Figure 8 and other figures, the frame structure 18 includes a left frame 18L, a right frame 18R, and a lateral frame 18M. As shown in Figures 3, 6, and other figures, the left frame 18L is provided on the left side of the vehicle body 2. The left frame 18L extends in the up-down direction along the vehicle body 2. The left frame 18L also extends in the front-rear direction along the vehicle body 2. The right frame 18R is provided on the right side of the vehicle body 2. The right frame 18R extends in the up-down direction along the vehicle body 2. The right frame 18R also extends in the front-rear direction along the vehicle body 2.

[0055] The left frame 18L connects the left front wheel 3LF and the left rear wheel 3LB. The right frame 18R connects the right front wheel 3RF and the right rear wheel 3RB. The left frame 18L and the right frame 18R are frames disposed on the sides of the vehicle body 2. For this reason, the left frame 18L and the right frame 18R may be collectively referred to as the "side frame 18LR."

[0056] The horizontal frame 18M connects the left frame 18L and the right frame 18R. More specifically, the horizontal frame 18M connects the upper part of the left frame 18L and the upper part of the right frame 18R. The horizontal frame 18M is a frame disposed above the vehicle body.

[0057] 3, the vehicle body 2 is disposed between the left frame 18L and the right frame 18R in a front view. In other words, the vehicle body 2 is disposed in a position sandwiched between the left frame 18L and the right frame 18R. The vehicle body 2 is also disposed below the lateral frame 18M. Therefore, the vehicle body 2 is disposed in a position surrounded by the left frame 18L, the right frame 18R, and the lateral frame 18M in a front view.

[0058] As shown in FIG. 9 and other figures, the left frame 18L is composed of a first left frame 19L and a second left frame 20L. The first left frame 19L includes a first front support pillar 19L1, a first rear support pillar 19L2, and a first connector 19L3. The first front support pillar 19L1 and the first rear support pillar 19L2 are spaced apart in the front-to-rear direction and extend parallel to each other in the up-down direction. As shown in FIGS. 3 and 6, the first front support pillar 19L1 is located on the left side of the front of the vehicle body 2. As shown in FIG. 4, the first rear support pillar 19L2 is located on the left side of the rear of the vehicle body 2. The first front support pillar 19L1 and the first rear support pillar 19L2 are formed in a cylindrical (rectangular) shape.

[0059] As shown in FIG. 9 , the first connector 19L3 connects the first front support 19L1 and the first rear support 19L2. The first connector 19L3 is composed of frame members 19AL, 19BL, 19CL, 19DL, and 19EL. The frame member 19AL extends in the front-to-rear direction and connects the upper portion of the first front support 19L1 to the upper portion of the first rear support 19L2. The frame member 19BL extends in the front-to-rear direction to the left of the frame member 19AL. The frame member 19CL connects the front portion of the frame member 19AL to the front portion of the frame member 19BL. The frame member 19DL connects the rear portion of the frame member 19AL to the rear portion of the frame member 19BL. The frame member 19EL connects a midpoint in the front-rear direction of the frame member 19AL and a midpoint in the front-rear direction of the frame member 19BL.

[0060] As shown in Figures 8, 9, and 10, the first left frame 19L has a left device support portion 19L4. The left device support portion 19L4 supports a battery (the second battery 36 or the first battery 35) (see Figures 1, 16, and 20). Note that in some figures (such as Figures 6 and 15), the left device support portion 19L4 and the battery supported by the left device support portion 19L4 are omitted.

[0061] The left device support part 19L4 is connected to the first connector 19L3. The left device support part 19L4 includes a first vertical member 19FL, a second vertical member 19GL, a third vertical member 19HL, a fourth vertical member 19IL, and a support plate 19JL. The first vertical member 19FL, the second vertical member 19GL, the third vertical member 19HL, and the fourth vertical member 19IL extend parallel to each other at intervals in the up-down direction.

[0062] The first and second vertical members 19FL and 19GL are connected at their upper portions to the frame member 19AL and extend downward. The third and fourth vertical members 19HL and 19IL are connected at their upper portions to the frame member 19BL and extend downward. The support plate 19JL is connected to the lower portions of the first, second, third, and fourth vertical members 19FL, 19GL, 19HL, and 19IL so that its upper surface is horizontal. A battery (the second battery 36 or the first battery 35, described later) is placed and supported on the upper surface of the support plate 19JL (see FIGS. 16 and 20). This allows the battery to be supported by the left device support portion 19L4.

[0063] As shown in FIG. 9 , the second left frame 20L is composed of a second front support 20L1, a second rear support 20L2, and a second connector 20L3. The second front support 20L1 and the second rear support 20L2 are spaced apart in the front-to-rear direction and extend parallel to each other in the up-down direction. The second connector 20L3 connects the second front support 20L1 and the second rear support 20L2. The second connector 20L3 is composed of frame members 20FL, 20GL, 20HL, and 20IL. The frame member 20FL extends in the front-to-rear direction and connects the upper portion of the second front support 20L1 to the upper portion of the second rear support 20L2. The frame member 20GL extends rightward from the front portion of the right surface of the frame member 20FL. The frame member 20HL extends rightward from the rear portion of the right surface of the frame member 20FL. The frame member 20IL extends rightward from the middle portion of the right surface of the frame member 20FL in the front-to-rear direction.

[0064] As shown by the downward arrow in Figure 9, the second front support 20L1 is inserted from above into the cylindrical first front support 19L1. The second rear support 20L2 is inserted from above into the cylindrical first rear support 19L2. This combines the first left frame 19L and the second left frame 20L (see Figure 10). The second front support 20L1 can move up and down along the first front support 19L1. The second rear support 20L2 can move up and down along the first rear support 19L2. This allows the second left frame 20L to move up and down relative to the first left frame 19L.

[0065] As shown in FIG. 9 , the right frame 18R is composed of a first right frame 21R and a second right frame 22R. The first right frame 21R includes a first front support pillar 21R1, a first rear support pillar 21R2, and a first connector 21R3. The first front support pillar 21R1 and the first rear support pillar 21R2 are spaced apart in the front-to-rear direction and extend parallel to each other in the up-down direction. As shown in FIGS. 3 and 6 , the first front support pillar 21R1 is located on the right side of the front portion of the vehicle body 2. As shown in FIG. 4 , the first rear support pillar 21R2 is located on the right side of the rear portion of the vehicle body 2. The first front support pillar 21R1 and the first rear support pillar 21R2 are formed in a cylindrical (rectangular) shape.

[0066] The first connector 21R3 connects the first front support 21R1 and the first rear support 21R2. The first connector 21R3 is composed of frame members 21AR, 21BR, 21CR, 21DR, and 21ER. The frame member 21AR extends in the front-to-rear direction and connects the upper part of the first front support 21R1 to the upper part of the first rear support 21R2. The frame member 21BR extends in the front-to-rear direction to the right of the frame member 21AR. The frame member 21CR connects the front part of the frame member 21AR to the front part of the frame member 21BR. The frame member 21DR connects the rear part of the frame member 21AR to the rear part of the frame member 21BR. The frame member 21ER connects the midpoint of the frame member 21AR to the midpoint of the frame member 21BR in the front-to-rear direction.

[0067] As shown in Figures 8, 9, and 10, the first right frame 21R has a right device support part 21R4. The right device support part 21R4 supports a battery (second battery 36) (see Figures 2, 16, and 20). Note that in some figures (such as Figures 6 and 15), the right device support part 21R4 and the battery supported by the right device support part 21R4 are omitted.

[0068] The right device support part 21R4 is connected to the first connector 21R3. The right device support part 21R4 has a first vertical member 21FR, a second vertical member 21GR, a third vertical member 21HR, a fourth vertical member 21IR, and a support plate 21JR. The first vertical member 21FR, the second vertical member 21GR, the third vertical member 21HR, and the fourth vertical member 21IR extend parallel to each other in the up-down direction with a gap between them.

[0069] The first vertical member 21FR and the second vertical member 21GR are connected at their upper parts to the frame member 21AR and extend downward. The third vertical member 21HR and the fourth vertical member 21IR are connected at their upper parts to the frame member 21BR and extend downward. The support plate 21JR is connected to the lower parts of the first vertical member 21FR, the second vertical member 21GR, the third vertical member 21HR, and the fourth vertical member 21IR so that its upper surface is horizontal. A second battery 36 (described later) is placed and supported on the upper surface of the support plate 21JR (see Figures 16 and 20). This allows the second battery 36 to be supported by the right device support section 21R4.

[0070] The second right frame 22R is composed of a second front support 22R1, a second rear support 22R2, and a second connector 22R3. The second front support 22R1 and the second rear support 22R2 are spaced apart in the front-to-rear direction and extend parallel to each other in the up-down direction. The second connector 22R3 connects the second front support 22R1 and the second rear support 22R2. The second connector 22R3 is composed of frame members 22FR, 22GR, 22HR, and 22IR. The frame member 22FR extends in the front-to-rear direction and connects the upper part of the second front support 22R1 to the upper part of the second rear support 22R2. The frame member 22GR extends leftward from the front portion of the left surface of the frame member 22FR. The frame member 22HR extends leftward from the rear portion of the left surface of the frame member 22FR. The frame member 22IR extends leftward from a midpoint in the front-to-rear direction of the left surface of the frame member 22FR.

[0071] As shown by the downward arrow in Figure 9, the second front support 22R1 is inserted from above into the cylindrical first front support 21R1. The second rear support 22R2 is inserted from above into the cylindrical first rear support 21R2. This combines the first right frame 21R and the second right frame 22R (see Figure 10). The second front support 22R1 can move up and down along the first front support 21R1. The second rear support 22R2 can move up and down along the first rear support 21R2. This allows the second right frame 22R to move up and down relative to the first right frame 21R.

[0072] As shown in Figure 10, the horizontal frame 18M is composed of frame members 18MA, 18MB, 18MC, 18MD, and 18ME. The frame member 18MA is located on the left side of the horizontal frame 18M and extends in the front-to-rear direction. The frame member 18MB is located on the right side of the horizontal frame 18M and extends in the front-to-rear direction. The frame members 18MA and 18MB are arranged parallel to each other with a gap in the left-to-right direction.

[0073] Frame members 18MC, 18MD, and 18ME extend parallel to one another in the left-right direction. Frame member 18MC connects the front of frame member 18MA to the front of frame member 18MB. Frame member 18MD connects the rear of frame member 18MA to the rear of frame member 18MB. Frame member 18ME connects the midpoint of frame member 18MA in the front-to-rear direction to the midpoint of frame member 18MB in the front-to-rear direction.

[0074] The frame members 18MC, 18MD, and 18ME are formed in a cylindrical (rectangular) shape. As shown by the arrows in Figure 10, the frame member 20GL is inserted into the frame member 18MC from the left, and the frame member 22GR is inserted from the right. The frame member 20HL is inserted into the frame member 18MD from the left, and the frame member 22HR is inserted from the right. The frame member 20IL is inserted into the frame member 18ME from the left, and the frame member 22IR is inserted from the right. This combines the horizontal frame 18M, the second left frame 20L, and the second right frame 22R (see Figure 10).

[0075] The frame member 20GL inserted into the frame member 18MC from the left can move left and right along the frame member 18MC. The frame member 20HL inserted into the frame member 18MD from the left can move left and right along the frame member 18MD. The frame member 20IL inserted into the frame member 18ME from the left can move left and right along the frame member 18ME. This allows the left frame 18L to move left and right relative to the horizontal frame 18M, to the left of the horizontal frame 18M.

[0076] The frame member 22GR inserted into the frame member 18MC from the right can move left and right along the frame member 18MC. The frame member 22HR inserted into the frame member 18MD from the right can move left and right along the frame member 18MD. The frame member 22IR inserted into the frame member 18ME from the right can move left and right along the frame member 18ME. This allows the right frame 18R to move left and right relative to the horizontal frame 18M, to the right of the horizontal frame 18M.

[0077] As described above, the second left frame 20L can move up and down relative to the first left frame 19L. The second right frame 22R can move up and down relative to the first right frame 21R. Therefore, the horizontal frame 18M (movable frame 32, described later) combined with the second left frame 20L and the second right frame 22R can move up and down relative to the first left frame 19L and the first right frame 21R (fixed frame 31, described later).

[0078] As shown in Figures 3, 4, and 6, the vehicle body 2 is fixed to the lower part of the horizontal frame 18M. Specifically, the vehicle body 2 is fixed to the lower part of the frame members 18MA and 18MB. This allows the vehicle body 2 to move integrally with the horizontal frame 18M. Therefore, when the horizontal frame 18M moves up and down relative to the first left frame 19L and the first right frame 21R, the vehicle body 2 moves up and down together with the horizontal frame 18M.

[0079] The frame structure 18 has a fixed frame 31 to which the traveling device 3 is attached, and a movable frame 32 attached to the vehicle body 2. Of the frame structure 18, the second left frame 20L, the second right frame 22R, and the horizontal frame 18M are movable frames 32 that are vertically movable. The first left frame 19L and the first right frame 21R are fixed frames 31 that do not move vertically. The vehicle body 2 moves vertically together with the movable frame 32 relative to the fixed frame 31, i.e., rises and falls.

[0080] A height change mechanism 90, which will be described later, changes the height of the vehicle body 2 from the ground by raising and lowering the movable frame 32 relative to the fixed frame 31. The traveling devices 3 are attached to the fixed frame 31. More specifically, the left traveling device 3L is attached to the first left frame 19L. The right traveling device 3R is attached to the first right frame 21R. When the movable frame 32 is raised and lowered relative to the fixed frame 31, the vehicle body 2 is raised and lowered relative to the traveling devices 3.

[0081] The left traveling device 3L is attached to the first left frame 19L. The right traveling device 3R is attached to the first right frame 21R. Hereinafter, the first left frame 19L to which the left traveling device 3L is attached will be referred to as the "left traveling section 25L," and the first right frame 21R to which the right traveling device 3R is attached will be referred to as the "right traveling section 25R." The left traveling section 25L includes the left traveling device 3L and the first left frame 19L. The right traveling section 25R includes the right traveling device 3R and the first right frame 21R.

[0082] Therefore, the work vehicle 1 is equipped with a left traveling section 25L including a left traveling device 3L arranged on the left side of the vehicle body 2, and a right traveling section 25R including a right traveling device 3R arranged on the right side of the vehicle body 2. The left traveling section 25L includes a left front wheel 3LF and a left rear wheel 3LB. The right traveling section 25R includes a right front wheel 3RF and a right rear wheel 3RB. When the movable frame 32 is raised or lowered relative to the fixed frame 31, the vehicle body 2 is raised or lowered relative to the left traveling section 25L and the right traveling section 25R.

[0083] As described above, the left frame 18L and the right frame 18R can move left and right relative to the lateral frame 18M. Because the vehicle body 2 is fixed to the lateral frame 18M, the left frame 18L and the right frame 18R can move left and right relative to the vehicle body 2. Specifically, the left frame 18L can move in a direction away from the vehicle body 2 (leftward) and a direction toward the vehicle body 2 (rightward). The right frame 18R can move in a direction away from the vehicle body 2 (rightward) and a direction toward the vehicle body 2 (leftward).

[0084] Because the left traveling unit 3L is attached to the left frame 18L (first left frame 19L), the left traveling unit 3L can move left and right as the left frame 18L moves left and right. Because the right traveling unit 3R is attached to the right frame 18R (first right frame 21R), the right traveling unit 3R can move left and right as the right frame 18R moves left and right. In other words, the left traveling unit 25L and the right traveling unit 25R can move left and right.

[0085] As shown in FIG. 7 , the work vehicle 1 is equipped with a drive unit 40 for driving the wheels (left front wheel 3LF, right front wheel 3RF, left rear wheel 3LB, and right rear wheel 3RB). The drive unit 40 includes a drive device 45 that generates power, a transmission mechanism 50 that transmits the power generated by the drive device 45 to the wheels 30, and a steering mechanism 60 that changes the direction of the wheels (left front wheel 3LF, right front wheel 3RF). In the present embodiment, the steering mechanism 60 is a mechanism that changes the direction of the front wheels (left front wheel 3LF, right front wheel 3RF), but it may also be a mechanism that changes the direction of the rear wheels (left rear wheel 3LB, right rear wheel 3RB). The steering mechanism 60 may also be a mechanism that changes the direction of both the front wheels and the rear wheels. The steering mechanism 60 may also be a mechanism that independently changes the direction of the left front wheel 3LF, right front wheel 3RF, left rear wheel 3LB, and right rear wheel 3RB.

[0086] 1 and 2, the drive unit 40 includes a first drive unit 41 for driving the left front wheel 3LF, a second drive unit 42 for driving the right front wheel 3RF, a third drive unit 43 for driving the left rear wheel 3LB, and a fourth drive unit 44 for driving the right rear wheel 3RB. The first drive unit 41, the second drive unit 42, the third drive unit 43, and the fourth drive unit 44 each have a drive device 45 and a transmission mechanism 50, which will be described later. The first drive unit 41 and the second drive unit 42 each have a steering mechanism 60, which will be described later. Each drive unit is attached to the frame structure 18.

[0087] In this embodiment, the drive device 45 is a motor. More specifically, the drive device 45 is the traveling motor 5 described above. In other words, the motor that constitutes the drive device 45 is the same as the motor included in the power unit 4 described above. As will be described below, the motors 5 that constitute the drive device 45 of the drive unit 40 include a motor 5LF, a motor 5RF, a motor 5LB, and a motor 5RB.

[0088] 1, the first drive unit 41 includes a motor 5LF and a transmission mechanism 50LF that transmits the power of the motor 5LF to the left front wheel 3LF. The transmission mechanism 50LF is configured with a gear mechanism including multiple gears. When the first drive unit 41 drives the motor 5LF, the power of the motor 5LF is transmitted to the left front wheel 3LF via the transmission mechanism 50LF.

[0089] 2, the second drive unit 42 includes a motor 5RF and a transmission mechanism 50RF that transmits the power of the motor 5RF to the right front wheel 3RF. The transmission mechanism 50RF is composed of a gear mechanism including multiple gears. When the second drive unit 42 drives the motor 5RF, the power of the motor 5RF is transmitted to the right front wheel 3RF via the transmission mechanism 50RF.

[0090] 1, the third drive unit 43 includes a motor 5LB and a transmission mechanism 50LB that transmits the power of the motor 5LB to the left rear wheel 3LB. The transmission mechanism 50LB is composed of a gear mechanism including multiple gears. When the third drive unit 43 drives the motor 5LB, the power of the motor 5LB is transmitted to the left rear wheel 3LB via the transmission mechanism 50LB.

[0091] 2, the fourth drive unit 44 has a motor 5RB and a transmission mechanism 50RB that transmits the power of the motor 5RB to the right rear wheel 3RB. The transmission mechanism 50RB is composed of a gear mechanism including a plurality of gears. When the fourth drive unit 44 drives the motor 5RB, the power of the motor 5RB is transmitted to the right rear wheel 3RB via the transmission mechanism 50RB.

[0092] As shown in Fig. 7, the drive unit 40 has a steering mechanism 60 that changes the direction of the wheels 30. In the present embodiment, the steering mechanism 60 is a mechanism that changes the direction of the front wheels (left front wheel 3LF and right front wheel 3RF) among the wheels 30. As shown in Figs. 1 and 2, the steering mechanism 60 includes a left steering mechanism 60L that changes the direction of the left front wheel 3LF and a right steering mechanism 60R that changes the direction of the right front wheel 3RF.

[0093] As shown in FIG. 1, the first drive unit 41 includes a left steering mechanism 60L. As shown in FIG. 2, the second drive unit 42 includes a right steering mechanism 60R. The left steering mechanism 60L drives the cylinder 62 to extend and retract the rod 62a, thereby rotating the left front wheel 3LF about the axis AX1. Similarly, the right steering mechanism 60R drives the cylinder 62 to extend and retract the rod 62a, thereby rotating the right front wheel 3RF about the axis AX2. In this way, by driving the steering mechanism 60 to change the orientation of the left front wheel 3LF and the right front wheel 3RF, the traveling direction of the traveling vehicle body 100 can be changed.

[0094] The left traveling section 25L includes a first drive unit 41 and a third drive unit 43. Therefore, the left traveling section 25L includes a motor 5LF and a transmission mechanism 50LF, a motor 5LB and a transmission mechanism 50LB, and a left steering mechanism 60L. The right traveling section 25R includes a second drive unit 42 and a fourth drive unit 44. Therefore, the right traveling section 25R includes a motor 5RF and a transmission mechanism 50RF, a motor 5RB and a transmission mechanism 50RB, and a right steering mechanism 60R.

[0095] As another embodiment of the drive unit 45, the motor of the drive unit 45 may be an in-wheel motor. In this case, all of the left front wheel 3LF, the right front wheel 3RF, the left rear wheel 3LB, and the right rear wheel 3RB may be driven by the in-wheel motor, or only some of the wheels (for example, the left front wheel 3LF and the right front wheel 3RF, or the left rear wheel 3LB and the right rear wheel 3RB) may be driven by the in-wheel motor.

[0096] As shown in FIG. 7 , the work vehicle 1 is equipped with a first detection device 70. The first detection device 70 detects the conditions around the vehicle body 2. The first detection device 70 detects, for example, the width of the travel path as the conditions around the vehicle body 2. The width of the travel path detected by the first detection device 70 is the width of an object that the work vehicle 1 is attempting to straddle between the left traveling device 3L and the right traveling device 3R. The first detection device 70 detects, for example, the width of a ridge on the ground or the width of an obstacle on the ground that obstructs travel, as the width of the travel path. Examples of obstacles that obstruct travel include grooves or holes formed in the ground, crops planted on the ground, and obstacles on the ground (for example, stones or artificial installations).

[0097] 7, the first detection device 70 includes a camera (image capture device) 71, a sensor 72, and a calculation unit 73. In the present embodiment, the first detection device 70 includes both the camera 71 and the sensor 72, but may include only one of them.

[0098] The camera 71 is composed of a CCD camera equipped with a CCD (Charge Coupled Devices) image sensor, a CMOS camera equipped with a CMOS (Complementary Metal Oxide Semiconductor) image sensor, or the like. The camera 71 is mounted on the vehicle body 2 and captures images of the surroundings of the vehicle body 2. The camera 71 may be capable of capturing images in at least one direction among the front, rear, left, and right of the vehicle body 2, including at least the traveling direction of the vehicle body 2. Preferably, the camera 71 is positioned so as to capture images in the front, rear, and sides (left and right) of the vehicle body 2. The camera 71 may also be positioned so as to capture images in directions other than the front, rear, and sides (left and right) of the vehicle body 2 (for example, the right front, left front, front-downward, rear-downward, etc.).

[0099] The camera 71 captures images of the surroundings of the vehicle body 2 and generates an image signal. The calculation unit 73 is composed of a computer or the like including a signal processing circuit that processes the generated image signal. The signal processing circuit detects the state of the object (presence or absence of the object, the position of the object, the type of the object, the size of the object, etc.) based on the image signal output from the camera 71. The object includes the aforementioned ridges, obstacles, etc.

[0100] The sensor 72 is an optical sensor, and is configured, for example, by a LiDAR (Light Detection And Ranging) sensor. The sensor 72 may also be an acoustic sensor. The acoustic sensor is configured, for example, by an airborne ultrasonic sensor such as a sonar. The sensor 72 preferably includes both an optical sensor and an acoustic sensor, but may also include either one of them.

[0101] The sensor 72 described above is mounted on the vehicle body 2 and detects objects around the vehicle body 2. The sensor 72 only needs to be able to detect objects in at least one direction, including the traveling direction of the vehicle body 2, among the front, rear, left, and right of the vehicle body 2. Preferably, the sensor 72 is arranged to detect objects in the front, rear, and sides (left and right) of the vehicle body 2. The sensor 72 may also be arranged to detect objects in directions other than the front, rear, and sides (left and right) of the vehicle body 2 (for example, in the front right, front left, front-downward, rear-downward, etc.).

[0102] As shown in Fig. 7, the work vehicle 1 is equipped with a second detection device 75. The second detection device 75 detects the distance between the left traveling device 3L and the right traveling device 3R. Hereinafter, the second detection device 75 may be referred to as the "distance detection device." As the second detection device (distance detection device) 75, for example, the optical sensor or sonic sensor described above can be used.

[0103] The distance between the left traveling unit 3L and the right traveling unit 3R detected by the second detection device 75 is the distance between the inner surface of the left traveling unit 3L and the inner surface of the right traveling unit 3R. Specifically, it is the smaller of the distance between the inner surface of the left front wheel 3LF and the inner surface of the right front wheel 3RF, and the distance between the inner surface of the left rear wheel 3LB and the inner surface of the right rear wheel 3RB.

[0104] 5, if the distance DB between the inner surface of the left rear wheel 3LB and the inner surface of the right rear wheel 3RB is smaller than the distance DF between the inner surface of the left front wheel 3LF and the inner surface of the right front wheel 3RF (DB<DF), the second detection device 75 detects the distance DB between the inner surface of the left rear wheel 3LB and the inner surface of the right rear wheel 3RB as the distance between the left traveling device 3L and the right traveling device 3R. If the distance DF between the inner surface of the left front wheel 3LF and the inner surface of the right front wheel 3RF and the distance DB between the inner surface of the left rear wheel 3LB and the inner surface of the right rear wheel 3RB are the same (DB=DF), the second detection device 75 detects either the distance DF or the distance DB as the distance between the left traveling device 3L and the right traveling device 3R. If the distance DF between the inner surface of the left front wheel 3LF and the inner surface of the right front wheel 3RF is smaller than the distance DB between the inner surface of the left rear wheel 3LB and the inner surface of the right rear wheel 3RB (DB > DF), the second detection device 75 detects the distance DF between the inner surface of the left front wheel 3LF and the inner surface of the right front wheel 3RF as the distance between the left running device 3L and the right running device 3R.

[0105] As shown in Fig. 7, the work vehicle 1 is equipped with a distance change mechanism 80. The distance change mechanism 80 changes the distance between the left traveling device 3L and the right traveling device 3R. As shown in Figs. 5 and 11, the distance change mechanism 80 includes a left change mechanism 80L that changes the left-right position of the left traveling device 3L, and a right change mechanism 80R that changes the left-right position of the right traveling device 3R. Note that Fig. 11 is a simplified view of Fig. 5.

[0106] As shown in Figures 5 and 11, the left changing mechanism 80L has a left cylinder 81L that moves the left traveling device 3L left or right. The left cylinder 81L moves the left front wheel 3LF and the left rear wheel 3LB left or right. The left front wheel 3LF and the left rear wheel 3LB are connected by a left connector 82L. As a result, the left cylinder 81L can move the left connector 82L left or right, thereby moving the left front wheel 3LF and the left rear wheel 3LB together left or right.

[0107] As shown in Figures 5 and 11, the right change mechanism 80R has a right cylinder 81R that moves the right traveling device 3R left or right. The right cylinder 81R moves the right front wheel 3RF and the right rear wheel 3RB left or right. The right front wheel 3RF and the right rear wheel 3RB are connected by a right connector 82R. As a result, the right cylinder 81R can move the right connector 82R left or right, thereby moving the right front wheel 3RF and the right rear wheel 3RB together left or right.

[0108] The lower end of the left connector 82L is located higher than the lower end of the left traveling unit 3L. The lower end of the right connector 82R is located higher than the lower end of the right traveling unit 3R. Therefore, the left connector 82L and the right connector 82R do not come into contact with the ground like the left traveling unit 3L and the right traveling unit 3R. The left connector 82L and the right connector 82R are positioned at a predetermined height so as not to come into contact with ridges, crops, etc.

[0109] In this embodiment, the left coupling part 82L is the left frame 18L of the frame structure 18. The right coupling part 82R is the right frame 18R of the frame structure 18. The left front wheel 3LF is rotatably attached to the first left frame 19L (see FIG. 9 ) of the left frame 18L via the above-mentioned first drive unit 41 and the like. The left rear wheel 3LB is rotatably attached to the first left frame 19L of the left frame 18L via the above-mentioned third drive unit 43 and the like during traveling.

[0110] The right front wheel 3RF is rotatably attached to the first right frame 21R of the right frame 18R (see FIG. 9) via the above-mentioned second drive unit 42, etc. The right rear wheel 3RB is rotatably attached to the first right frame 21R of the right frame 18R via the above-mentioned fourth drive unit 44, etc. during traveling.

[0111] This allows the left front wheel 3LF and the left rear wheel 3LB (i.e., the left traveling device 3L) to move left and right together with the left frame 18L. Also, the right front wheel 3RF and the right rear wheel 3RB (i.e., the right traveling device 3R) to move left and right together with the right frame 18R.

[0112] The right cylinder 81R and the left cylinder 81L are hydraulic cylinders that are operated (extended and retracted) by hydraulic oil supplied from a hydraulic pump driven by the working motor 6 described above.

[0113] As shown in Figures 5 and 11, the left cylinder 81L has a cylinder tube 81La attached to the vehicle body 2 and a rod 81Lb that protrudes from the cylinder tube 81La and extends to the left. A left coupling part 82L is connected to the tip of the rod 81Lb of the left cylinder 81L. When the rod 81Lb of the left cylinder 81L extends to the left, the left coupling part 82L moves to the left, and the left front wheel 3LF and the left rear wheel 3LB move together to the left. When the rod 81Lb of the left cylinder 81L contracts to the right, the left coupling part 82L moves to the right, and the left front wheel 3LF and the left rear wheel 3LB move together to the right.

[0114] As shown in Figures 5 and 11, the right cylinder 81R has a cylinder tube 81Ra attached to the vehicle body 2 and a rod 81Rb that protrudes from the cylinder tube 81Ra and extends to the right. A right coupling 82R is connected to the tip of the rod 81Rb of the right cylinder 81R. When the rod 81Rb of the right cylinder 81R extends to the right, the right coupling 82R moves to the right, and the right front wheel 3RF and the right rear wheel 3RB move together to the right. When the rod 81Rb of the right cylinder 81R contracts to the left, the right coupling 82R moves to the left, and the right front wheel 3RF and the right rear wheel 3RB move together to the left.

[0115] As described above, the left front wheel 3LF and the left rear wheel 3LB (i.e., the left traveling device 3L) can be changed in lateral position by operating (extending and retracting) the left cylinder 81L. Also, the right front wheel 3RF and the right rear wheel 3RB (i.e., the right traveling device 3R) can be changed in lateral position by operating (extending and retracting) the right cylinder 81R. Therefore, the distance between the left traveling device 3L and the right traveling device 3R can be changed by operating one or both of the left cylinder 81L and the right cylinder 81R.

[0116] When changing the distance between the left traveling device 3L and the right traveling device 3R, it is preferable to move (extend or shorten) the rods of the left cylinder 81L and the right cylinder 81R the same distance in opposite directions. However, when changing the distance between the left traveling device 3L and the right traveling device 3R, it is also possible to move the rods of the left cylinder 81L and the right cylinder 81R by different distances in opposite directions, or to move the rods of the left cylinder 81L and the right cylinder 81R by different distances in the same direction.

[0117] 5 and 11 show a state in which the rods of the left cylinder 81L and the right cylinder 81R are retracted. In this state, the distance DB (see FIG. 5) between the left traveling unit 3L and the right traveling unit 3R is short. By extending the rods of the left cylinder 81L and the right cylinder 81R from this state (see arrows YL and YR in FIG. 12), the left traveling unit 3L (left front wheel 3LF, left rear wheel 3LB) and the right traveling unit 3R (right front wheel 3RF, right rear wheel 3RB) move in opposite directions (see arrows in FIG. 11). This allows the distance DB (see FIG. 5) between the left traveling unit 3L and the right traveling unit 3R to be increased, as shown in FIG. 12.

[0118] The operation of the distance change mechanism 80 is controlled by the control device 15. As shown in FIG. 7 , the control device 15 includes a distance change control unit 15B. The distance change mechanism 80 changes the distance between the left traveling device 3L and the right traveling device 3R so that the distance between the left traveling device 3L and the right traveling device 3R corresponds to the detection result of the first detection device 70. In this embodiment, the distance change control unit 15B operates the distance change mechanism 80 based on the detection results of the first detection device 70 and the second detection device 75 to change the distance between the left traveling device 3L and the right traveling device 3R.

[0119] The distance change operation by the distance change mechanism 80 is performed by the distance change control unit 15B controlling the distance change mechanism 80. An example of the operation of the distance change mechanism 80 will be described below, and the operation of the distance change mechanism 80 in the following description is performed by the distance change control unit 15B controlling the distance change mechanism 80 based on the detection results of the first detection device 70 and / or the second detection device 75. In other words, the operation of the distance change mechanism 80 described below is controlled by the distance change control unit 15B.

[0120] For example, when the first detection device 70 detects the width of the traveling path, the distance change mechanism 80 changes the distance between the left traveling device 3L and the right traveling device 3R so that the distance between them corresponds to the width of the traveling path. More specifically, when the first detection device 70 detects the width of the traveling path, the distance change mechanism 80 changes the distance between the left traveling device 3L and the right traveling device 3R so that the distance between them is the width of the traveling path or wider than the width of the traveling path (i.e., equal to or greater than the width of the traveling path).

[0121] As a specific example, when the first detection device 70 detects the width of a ridge path, the distance change mechanism 80 changes the distance between the left traveling device 3L and the right traveling device 3R so that the distance between them corresponds to the width of the ridge. More specifically, while the vehicle body 2 is traveling, the distance change mechanism 80 changes the distance between the left traveling device 3L and the right traveling device 3R so that the traveling device 3 can straddle the detected ridge. In other words, the distance change mechanism 80 changes the distance between the left traveling device 3L and the right traveling device 3R so that the distance between them is the same as or wider than the width of the ridge (i.e., greater than or equal to the width of the ridge).

[0122] Furthermore, when the first detection device 70 detects the width of an obstacle, the distance change mechanism 80 changes the distance between the left traveling device 3L and the right traveling device 3R so that the traveling device 3 can straddle the detected obstacle while the vehicle body 2 is traveling. In other words, the distance change mechanism 80 changes the distance between the left traveling device 3L and the right traveling device 3R so that the distance between the left traveling device 3L and the right traveling device 3R is the same as or wider than the width of the obstacle (i.e., so that it is equal to or greater than the width of the obstacle).

[0123] The distance change mechanism 80 can individually operate the left change mechanism 80L and the right change mechanism 80R based on the detection results of the first detection device 70. In the present embodiment, the distance change mechanism 80 can individually operate the left change mechanism 80L and the right change mechanism 80R based on the detection results of the first detection device 70 and the detection results of the second detection device 75. As a result, the distance change mechanism 80 can operate only the left change mechanism 80L, can operate only the right change mechanism 80R, or can operate both the left change mechanism 80L and the right change mechanism 80R.

[0124] The distance change mechanism 80 changes the distance between the left traveling device 3L and the right traveling device 3R by operating both or one of the left change mechanism 80L and the right change mechanism 80R of the distance change mechanism 80. When the left change mechanism 80L is operated, the rod of the left cylinder 81L extends or retracts, changing the left-right position of the left traveling device 3L. When the right change mechanism 80R is operated, the rod of the right cylinder 81R extends or retracts, changing the left-right position of the right traveling device 3R. By changing the left-right positions of both or one of the left traveling devices 3L and the right traveling device 3R, the distance between the left traveling device 3L and the right traveling device 3R is changed. Preferably, the distance change control unit 15B changes the left-right positions of both the left traveling device 3L and the right traveling device 3R by the same distance in opposite directions.

[0125] The second detection device 75 can detect the distance between the left traveling device 3L and the right traveling device 3R by detecting the amount of extension and contraction of each of the left change mechanism 80L and the right change mechanism 80R. Specifically, the second detection device 75 can detect the distance between the left traveling device 3L and the right traveling device 3R by detecting the amount of extension and contraction of the rod of the left cylinder 81L of the left change mechanism 80L and the amount of extension and contraction of the rod of the right cylinder 81R of the right change mechanism 80R.

[0126] In this case, information such as the relationship between the extension and contraction amount of the rod of the left cylinder 81L and the position of the left traveling unit 3L, the relationship between the extension and contraction amount of the rod of the right cylinder 81R and the position of the right traveling unit 3R, and the relationship between "the positions of the left traveling unit 3L and the right traveling unit 3R" and "the distance between the left traveling unit 3L and the right traveling unit 3R" is stored in advance in the memory unit of the control unit 15. The second detection device 75 detects the extension and contraction amount of the rods of the left cylinder 81L and the right cylinder 81R, and detects the distance between the left traveling unit 3L and the right traveling unit 3R based on the detection result and the information stored in the memory unit.

[0127] As shown in Figure 7, the work vehicle 1 is equipped with a height change mechanism 90. The height change mechanism 90 changes the height of the vehicle body 2 from the ground. The height change mechanism 90 raises and lowers the vehicle body 2 on which the battery 7 is mounted (housed). The height change mechanism 90 raises and lowers the vehicle body 2 at a position between the left traveling unit 3L and the right traveling unit 3R in the width direction (left-right direction) of the vehicle body 2. The height change mechanism 90 changes the height of the vehicle body 2 from the ground by raising and lowering a frame structure 18 attached to the vehicle body 2.

[0128] As shown in Figures 2, 3, 6, etc., the height change mechanism 90 has a lifting cylinder 91. The lifting cylinder 91 raises and lowers the movable frames 32 (second left frame 20L, second right frame 22R, and lateral frame 18M) of the frame structure 18. The vehicle body 2 is raised and lowered by raising and lowering the movable frames 32. Therefore, the vehicle body 2 can be raised and lowered by driving the lifting cylinder 91. In this way, the height change mechanism 90 is a mechanism that can raise and lower the vehicle body 2. Hereinafter, the height change mechanism 90 may be referred to as the "lifting mechanism 90."

[0129] The lift cylinder 91 is composed of a hydraulic cylinder. The lift cylinder 91 has a rod 91a that extends and retracts in the vertical direction and a cylinder tube 91b to which hydraulic oil is supplied to drive the rod 91a (see FIG. 1, etc.). The tip of the rod 91a is connected to the frame structure 18. The lift cylinder 91 includes a left lift cylinder 91L and a right lift cylinder 91R. The left lift cylinder 91L is disposed on the left side of the vehicle body 2. The right lift cylinder 91R is disposed on the right side of the vehicle body 2.

[0130] 1 and 6, the rod 91La of the left lifting cylinder 91L is connected to the second left frame 20L of the frame structure 18. More specifically, the rod 91La of the left lifting cylinder 91L is connected to a left plate 99L fixed to the second left frame 20L. This allows the left lifting cylinder 91L to lift and lower the second left frame 20L, which is a movable frame of the left frame 18L, by extension and contraction of the rod 91La.

[0131] 2 and 6, the rod 91Ra of the right lift cylinder 91R is connected to the second right frame 22R of the frame structure 18. More specifically, the rod 91Ra of the right lift cylinder 91R is connected to a right plate 99R fixed to the second right frame 22R. This allows the right lift cylinder 91R to lift and lower the second right frame 22R, which is a movable frame of the right frame 18R, by extension and contraction of the rod 91Ra.

[0132] The cylinder tube 91Lb of the left lift cylinder 91L is attached to a bracket (not shown) fixed to the first left frame 19L. The cylinder tube 91Rb of the right lift cylinder 91R is attached to a bracket (not shown) fixed to the first right frame 21R. As shown in FIGS. 1 and 2 , the lower ends (lower ends of the cylinder tubes 91Lb, 91Rb) of the lift cylinders (left lift cylinder 91L, right lift cylinder 91R) are located at the same or approximately the same height from the ground as the vehicle body 2 when the vehicle body 2 is at a height (a first height described below) between the left traveling unit 3L and the right traveling unit 3R.

[0133] However, the lower ends of the lifting cylinders (left lifting cylinder 91L, right lifting cylinder 91R) do not have to be positioned at the same or approximately the same height from the ground as the vehicle body 2 when it is at a height between the left running device 3L and the right running device 3R (the first height described later).

[0134] In this embodiment, the lower ends (lower ends of the cylinder tubes 91Lb, 91Rb) of the lifting cylinders (left lifting cylinder 91L, right lifting cylinder 91R) are located at a height slightly higher than the height HA of the vehicle body 2 from the ground when the vehicle body 2 is at a height located between the left running unit 3L and the right running unit 3R (see Figure 1).

[0135] When the rod 91La of the left lift cylinder 91L extends and retracts, the second left frame 20L rises and lowers. When the rod 91Ra of the right lift cylinder 91R extends and retracts, the second right frame 22R rises and lowers. This allows the frame structure 18 to rise and lower as the rods 91a of the lift cylinders 91 (left lift cylinder 91L, right lift cylinder 91R) extend and retract. Because the vehicle body 2 is attached to the frame structure 18, the vehicle body 2 can be raised and lowered as the rods 91a of the lift cylinders 91 extend and retract. By raising and lowering the vehicle body 2, the height of the vehicle body 2 from the ground can be changed.

[0136] 13, 14, and 15 show a state in which the rod 91a of the lifting cylinder 91 is extended to raise the vehicle body 2. As the vehicle body 2 rises, the mounting part 10 provided on the vehicle body 2 also rises. Therefore, by raising the vehicle body 2, the working device mounted on the mounting part 10 can also be raised.

[0137] The operation of the height change mechanism 90 is controlled by the control device 15. As shown in Fig. 7 , the control device 15 includes a height change control unit 15C. The height change control unit 15C transmits a control signal to the height change mechanism 90 by causing the calculation unit of the control device 15 to execute a program stored in the storage unit. The height change mechanism 90 is driven based on the control signal transmitted from the height change control unit 15C. In other words, the height change mechanism 90 changes the height of the vehicle body 2 by being driven based on the control of the control device 15.

[0138] The height change mechanism 90 can change the height of the car body 2 to any height within a preset height range. Specifically, the height change mechanism 90 can change the height of the car body 2 to any height between a first height HA (see FIGS. 1 and 3) and a second height HB (see FIGS. 13 and 14) that is higher than the first height HA. In other words, the preset height range is the range between the first height HA and the second height HB. In this embodiment, the height of the car body 2 when the rod of the lift cylinder 91 is at its shortest is the first height HA, and the height of the car body 2 when the rod of the lift cylinder 91 is at its longest is the second height HB.

[0139] The first height HA is the lowest height (lower limit height) of the height of the vehicle body 2 that can be changed by the height change mechanism 90. The second height HB is the highest height (upper limit height) of the height of the vehicle body 2 that can be changed by the height change mechanism 90. The height change mechanism 90 can change the height of the vehicle body 2 to the first height HA, which is the lower limit height, the second height HB, which is the upper limit height, or any height (intermediate height) between the upper limit height and the lower limit height.

[0140] The height change mechanism 90 can change the height of the vehicle body 2 in response to a height specification made by an operation device 101 (see FIG. 7 ). The operation device 101 is a device that can perform an operation to specify the height of the vehicle body 2. The operation device 101 is a device (external device) that is located outside the work vehicle 1, and is configured to be able to communicate with the control device 15 wirelessly or via a wire. The operation device 101 is, for example, a portable device such as a remote control device, a tablet, a smartphone, or a PDA.

[0141] The operation device 101 is equipped with an input unit for inputting the desired height of the vehicle body 2. The input unit is, for example, a push button, a rotary dial, a touch panel, etc. When the operator inputs the desired height from the input unit of the operation device 101, the input specified height is sent to the control device 15. The control device 15 sends a control signal to drive the lifting cylinder 91 of the height change mechanism 90 so that the height of the vehicle body 2 becomes the specified height. As a result, the height of the vehicle body 2 is changed to the height specified by the operation device 101.

[0142] The height change mechanism 90 can change the height of the vehicle body 2 in accordance with the height of crops planted on the ground on which the work vehicle 1 travels. In this case, the height of the crops planted on the ground can be detected by the first detection device 70 described above. The height of the crops detected by the first detection device 70 is sent to the control device 15. The control device 15 sends a control signal to drive the lifting cylinder 91 of the height change mechanism 90 so that the height of the vehicle body 2 is higher than the height of the crops. In this way, the height change mechanism 90 can change the height of the vehicle body 2 in accordance with the height of the crops detected by the first detection device 70.

[0143] As described above, the vehicle body 2 is disposed between the left traveling unit 3L and the right traveling unit 3R. The height change mechanism 90 raises and lowers the vehicle body 2 between the left traveling unit 3L and the right traveling unit 3R to change the height of the vehicle body 2. In other words, the vehicle body 2 moves up and down through the space formed between the left traveling unit 3L and the right traveling unit 3R.

[0144] The work vehicle 1 is equipped with a plurality of batteries capable of storing power for driving the left traveling section 25L and the right traveling section 25R (more specifically, the left traveling device 3L and the right traveling device 3R). At least one of the plurality of batteries is disposed in either the left traveling section 25L or the right traveling section 25R. The plurality of batteries includes a first battery 35 used during traveling or work, and a second battery 36 used during traveling or work. The first battery 35 and the second battery 36 will be described below with reference to the drawings.

[0145] 1 to 5 and 16, the work vehicle 1 is equipped with a first battery 35 that is used when traveling or working, and a second battery 36 that is used when traveling or working. In Fig. 16, the second battery 36 is hatched to clarify its position. Fig. 16 is a diagram for explaining the arrangement of the first battery 35 and the second battery 36, and configuration that is not relevant to the explanation is omitted.

[0146] In this embodiment, the first battery 35 is a battery that stores power supplied to a motor that generates the power required for traveling or working. The motor that generates the power required for traveling is the traveling motor 5 described above. The motor that generates the power required for working is the work motor 6 described above. The first battery 35 is battery 7 that stores power supplied to the traveling motor 5 or the work motor 6.

[0147] The second battery 36 is a battery having the same function as the first battery 35. In the present embodiment, since the first battery 35 is the battery 7 that stores the electric power supplied to the motor that generates the power required for traveling or working, the second battery 36 is also the battery 7 that stores the electric power supplied to the motor that generates the power required for traveling or working.

[0148] For example, if the first battery 35 is a battery 7 that stores power supplied to the traveling motor 5, then the second battery 36 is also a battery 7 that stores power supplied to the traveling motor 5. If the first battery 35 is a battery 7 that stores power supplied to the work motor 6, then the second battery 36 is also a battery 7 that stores power supplied to the work motor 6. If the first battery 35 is a battery 7 that stores power supplied to the traveling motor 5 and the work motor 6, then the second battery 36 is also a battery 7 that stores power supplied to the traveling motor 5 and the work motor 6.

[0149] The first battery 35 and the second battery 36 are devices used when the work vehicle 1 is traveling or working, and are batteries that perform the same function when traveling or working. The first battery 35 and the second battery 36 may be different in shape and size.

[0150] The first battery 35 and the second battery 36 have the same function and have the same structure or operating principle for performing that function. Therefore, the first battery 35 and the second battery 36 have the same structure or operating principle for performing the function of storing electricity.

[0151] For example, if the first battery 35 is a lithium ion battery, the second battery 36 is also a lithium ion battery. For example, if the first battery 35 is a lithium ion battery, the second battery 36 does not include a lead battery. This is because a lead battery stores electricity using a different structure or operating principle than a lithium ion battery.

[0152] As can be seen from the above example, the second battery 36 can also be said to be a device obtained by dividing a part of the first battery 35. In other words, the first battery 35, which was previously one battery (or one group of batteries), can also be said to have been divided into the first battery 35 and the second battery 36. In other words, the first battery 35, which was previously one battery, can be said to have been divided into two or more batteries (the first battery 35 and the second battery 36).

[0153] 1 to 5 and 16, the first battery 35 is disposed in the vehicle body 2. Specifically, the first battery 35 is housed in the interior space of the vehicle body 2. The second battery 36 is disposed in at least one of the left traveling section 25L and the right traveling section 25R. In other words, the second battery 36 may be disposed in both the left traveling section 25L and the right traveling section 25R, or in only one of the left traveling section 25L and the right traveling section 25R.

[0154] As shown in Figures 1 and 18, the second battery 36 disposed on the left traveling section 25L is disposed between the left front wheel 3LF and the left rear wheel 3LB. As shown in Figures 2 and 18, the second battery 36 disposed on the right traveling section 25R is disposed between the right front wheel 3RF and the right rear wheel 3RB. Since the second battery 36 is disposed on at least one of the left traveling section 25L and the right traveling section 25R, the second battery 36 is disposed at least one of between the left front wheel 3LF and the left rear wheel 3LB and between the right front wheel 3RF and the right rear wheel 3RB. Preferably, the second battery 36 is disposed both between the left front wheel 3LF and the left rear wheel 3LB and between the right front wheel 3RF and the right rear wheel 3RB.

[0155] 1 and 2, the second battery 36 is disposed below the traveling motor 5. The second battery 36 and the traveling motor 5 are both disposed on the side (left or right) of the vehicle body 2, and are disposed one above the other on the side of the vehicle body 2. The second battery 36 is disposed in front of the fenders 55L, 55R on the side of the vehicle body 2. The second battery 36 is also disposed behind the lifting cylinder 91 on the side of the vehicle body 2.

[0156] As described above, in the work vehicle 1, multiple batteries (the first battery 35 and the second battery 36) having the same function are distributed among the vehicle body 2 and the left traveling section 25L and / or the right traveling section 25R. This reduces the weight of the vehicle body 2. Therefore, it is possible to prevent the weight of the batteries (the first battery 35 and the second battery 36) having the same function from being concentrated in the vehicle body 2.

[0157] 16, the second battery 36 is disposed in both the left traveling section 25L and the right traveling section 25R. Therefore, batteries having the same function (the first battery 35 and the second battery 36) are dispersed and disposed in three locations: the vehicle body 2, the left traveling section 25L, and the right traveling section 25R. This allows the weight balance of the work vehicle 1 (particularly the weight balance in the left-right direction) to be improved.

[0158] In the present embodiment shown in FIG. 17 , the second battery 36 is disposed in only one of the left traveling section 25L and the right traveling section 25R. Specifically, the second battery 36 is disposed only in the left traveling section 25L of the left traveling section 25L and the right traveling section 25R. In this case, it is preferable that a device 37 other than a battery (first battery 35, second battery 36) is disposed in the right traveling section 25R. By disposing a device 37 other than a battery in the right traveling section 25R, the left-right weight balance can be optimized. Although not shown, the second battery 36 may be disposed only in the right traveling section 25R of the left traveling section 25L and the right traveling section 25R, and the device 37 may be disposed in the left traveling section 25L.

[0159] In this way, when the second battery 36 is placed in only one of the left and right running sections 25L and 25R (for example, the left running section 25L), it is preferable to place a device 37 different from the battery (first battery 35, second battery 36) in the other running section (for example, the right running section 25R).

[0160] For example, if the second battery 36 is placed in only one of the left and right running sections 25L and 25R, the other running section can be placed with one or more pieces of equipment 37 selected from a running motor 5, a working motor 6, an engine, a fuel cell, a hydraulic pump, a hydraulic oil tank, a spray tank, a hydrogen tank, etc.

[0161] The weight of the first battery 35 arranged in the vehicle body 2 and the weight of the second battery 36 arranged in the left traveling section 25L and / or the right traveling section 25R may be the same as or different from each other. If they are different, the weight of the first battery 35 arranged in the vehicle body 2 may be heavier or lighter than the weight of the second battery 36 arranged in the left traveling section 25L and / or the right traveling section 25R.

[0162] For example, if a first battery 35 is disposed on the vehicle body 2 and a second battery 36 is disposed on the left traveling section 25L and the right traveling section 25R, the second battery 36 disposed on the left traveling section 25L and the second battery 36 disposed on the right traveling section 25R can be made the same weight. Furthermore, the first battery 35 disposed on the vehicle body 2, the second battery 36 disposed on the left traveling section 25L, and the second battery 36 disposed on the right traveling section 25R can be made the same weight. Furthermore, the weight of the first battery 35 disposed on the vehicle body 2 can be the combined weight of the second battery 36 disposed on the left traveling section 25L and the second battery 36 disposed on the right traveling section 25R. Furthermore, the second battery 36 disposed on the left traveling section 25L and the second battery 36 disposed on the right traveling section 25R can be made the same size (same height, width, and depth).

[0163] Furthermore, when the second battery 36 is disposed only in one of the traveling sections (for example, the left traveling section 25L) and the equipment 37 is disposed in the other traveling section (for example, the right traveling section 25R), it is preferable that the weight of the equipment 37 be the same as or close to the weight of the second battery 36. It is also preferable that the second battery 36 and the equipment 37 have the same size (same height, width, and depth).

[0164] As shown in FIGS. 1 and 16 , the second battery 36 disposed in the left running section 25L is disposed on the left frame 18L of the left running section 25L. More specifically, the second battery 36 disposed in the left running section 25L is disposed on the first left frame 19L. Specifically, the second battery 36 disposed in the left running section 25L is supported by the left device support section 19L4 of the first left frame 19L. More specifically, the second battery 36 disposed in the left running section 25L is supported on the support plate 19JL of the left device support section 19L4.

[0165] As shown in Figures 2 and 16, the second battery 36 disposed on the right running section 25R is disposed on the right frame 18R of the right running section 25R. More specifically, the second battery 36 disposed on the right running section 25R is disposed on the first right frame 21R. Specifically, the second battery 36 disposed on the right running section 25R is supported by the right device support section 21R4 of the first right frame 21R. More specifically, the second battery 36 disposed on the right running section 25R is supported on the support plate 21JR of the right device support section 21R4.

[0166] The configurations of the left device support portion 19L4 and the right device support portion 21R4 are as shown in Figures 8 to 10, etc. However, the configurations of the left device support portion 19L4 and the right device support portion 21R4 are not limited to the configurations shown in Figures 8 to 10, etc. The left device support portion 19L4 may be configured in any way as long as it can place (support) the second battery 36 (or the first battery 35) on the first left frame 19L. The right device support portion 21R4 may be configured in any way as long as it can place (support) the second battery 36 (or the first battery 35) on the first right frame 21R.

[0167] If the second battery 36 is disposed on only one of the left traveling section 25L and the right traveling section 25R, the device support section on which the second battery 36 is not disposed may be omitted. For example, if the second battery 36 is disposed on only the left traveling section 25L, the right device support section 21R4 on which the second battery 36 is not disposed may be omitted. If the second battery 36 is disposed on only the right traveling section 25R, the left device support section 19L4 on which the second battery 36 is not disposed may be omitted.

[0168] As described above, the first left frame 19L and the first right frame 21R are fixed frames 31 that do not move in the vertical direction. Therefore, the frames included in the left running section 25L and the right running section 25R (first left frame 19L, first right frame 21R) are frames (fixed frames 31) that do not move in the vertical direction. Therefore, the second battery 36 is disposed in a frame that does not move in the vertical direction (does not rise and fall).

[0169] As described above, the left traveling device 3L can move left and right together with the left frame 18L, which includes the first left frame 19L. Therefore, the left traveling section 25L can move left and right. Furthermore, the right traveling device 3R can move left and right together with the right frame 18R, which includes the first right frame 21R. Therefore, the right traveling section 25R can move left and right. Therefore, the second battery 36 is disposed on the frames (first left frame 19L, first right frame 21R) that can move left and right.

[0170] As described above, in the work vehicle 1, of the multiple batteries (first battery 35 and second battery 36) having the same function, some of the batteries (first battery 35) are arranged in the vehicle body 2 which can be raised and lowered, and the remaining batteries (second battery 36) are arranged in frames which do not rise and lower (first left frame 19L, first right frame 21R). Also, in the work vehicle 1, of the multiple batteries (first battery 35 and second battery 36) having the same function, some of the batteries (first battery 35) are arranged in the vehicle body 2 which does not move in the left-right direction, and the remaining devices (second battery 36) are arranged in frames which can move in the left-right direction (first left frame 19L, first right frame 21R).

[0171] The second battery 36 is preferably disposed below at least one of the left traveling section 25L and the right traveling section 25R. In the present embodiment, as shown in FIG. 16 , the second battery 36 is disposed below the left traveling section 25L and the right traveling section 25R. By disposing the second battery 36 below the left traveling section 25L and / or the right traveling section 25R, the center of gravity of the work vehicle 1 can be lowered. This allows the work vehicle 1 to be stabilized while traveling and during work.

[0172] In this embodiment, as shown in FIG. 16 , the second battery 36 is disposed below the vertical center C1 of the first left frame 19L or the first right frame 21R. The vertical center C4 of the second battery 36 is located below the vertical center C2 of the left traveling section 25L or the right traveling section 25R. The vertical center C4 of the second battery 36 is located below the vertical center C3 of the rear wheels (left rear wheel 3LB, right rear wheel 3RB). The upper end of the second battery 36 is located above the vertical center C3 of the rear wheels (left rear wheel 3LB, right rear wheel 3RB). The upper end of the second battery 36 is located above the vertical center C2 of the left traveling section 25L or the right traveling section 25R. Furthermore, as shown in FIGS. 1 and 2 , the upper end of the second battery 36 is located below the upper ends of the front wheels (left front wheel 3LF, right front wheel 3RF).

[0173] 1, 2, and 16, in this embodiment, the height of the lower end of the second battery 36 is the same as or approximately the same as the height of the lower end of the vehicle body 2. Furthermore, the height of the upper end of the second battery 36 is lower than the height of the upper end of the first battery 35. However, the height of the lower end of the second battery 36 may be lower or higher than the height of the lower end of the vehicle body 2. Furthermore, the height of the upper end of the second battery 36 may be the same as or approximately the same as the height of the upper end of the first battery 35, or may be higher than the height of the upper end of the first battery 35.

[0174] The first battery 35 is preferably disposed in the lower part of the vehicle body 2. In this embodiment, as shown in FIG. 16 , the vertical center C6 of the first battery 35 is disposed below the vertical center C5 of the vehicle body 2. The upper end of the first battery 35 is disposed below the vertical center C5 of the vehicle body 2. However, the upper end of the first battery 35 may be disposed above the vertical center C5 of the vehicle body 2. The first battery 35 may also be disposed at a position other than the lower part of the vehicle body 2 (for example, at the upper part). Although the upper end of the first battery 35 is disposed below the vertical center C1 of the first left frame 19L or the first right frame 21R in FIG. 16 , it may be disposed above the vertical center C1.

[0175] 16, by arranging the first battery 35 in the lower part of the vehicle body 2, it is possible to lower the center of gravity of the vehicle body 2. This makes it possible to stabilize the work vehicle 1 while traveling or during work.

[0176] Furthermore, in the work vehicle 1, batteries (first battery 35 and second battery 36) having the same functions are disposed not only in the vehicle body 2 but also dispersedly in the left traveling section 25L and / or the right traveling section 25R. This makes it possible to reduce the size of the first battery 35 disposed in the vehicle body 2, and to keep the height of the first battery 35 low. This also makes it possible to lower the center of gravity of the vehicle body 2.

[0177] 16 , when the vehicle body 2 is lowered (at the first height), the vertical positions of the first battery 35 and the second battery 36 at least partially overlap. This allows the vertical centers of gravity of the vehicle body 2, the left traveling section 25L, and the right traveling section 25R to be close to each other (at similar heights). This results in a good vertical weight balance of the work vehicle 1.

[0178] 18 , the longitudinal positions of the first battery 35 and the second battery 36 at least partially overlap. In this case, the longitudinal centers of gravity of the vehicle body 2, the left traveling section 25L, and the right traveling section 25R can be positioned close to each other. This improves the longitudinal weight balance of the work vehicle 1. However, the longitudinal positions of the first battery 35 and the second battery 36 do not have to overlap. That is, the longitudinal position of the first battery 35 may be forward of the longitudinal position of the second battery 36, or the longitudinal position of the first battery 35 may be rearward of the longitudinal position of the second battery 36.

[0179] Preferably, the front-rear position of the first battery 35 is the same as the front-rear position of the second battery 36. Furthermore, it is also preferable that the front-rear position of the second battery 36 arranged in the left traveling section 25L is the same as the front-rear position of the second battery 36 arranged in the right traveling section 25R. By arranging the first battery 35 and the second battery 36 in this manner, the front-rear weight balance of the work vehicle 1 is further improved.

[0180] 18 , the outer ends of the second batteries 36 disposed on the left traveling section 25L and / or the right traveling section 25R are located inward (closer to the vehicle body 2) than the outer ends of the wheels 30. Specifically, the left end of the second battery 36 disposed on the left traveling section 25L is located to the right of the left ends of the left front wheel 3LF and the left rear wheel 3LB. The right end of the second battery 36 disposed on the right traveling section 25R is located to the left of the right ends of the right front wheel 3RF and the right rear wheel 3RB.

[0181] Furthermore, the outer end of the second battery 36 disposed on the left traveling section 25L and / or the right traveling section 25R is located inward (closer to the vehicle body 2) than the outer end of the side frame 18LR. Specifically, the left end of the second battery 36 disposed on the left traveling section 25L is located to the right of the left end of the left frame 18L. The right end of the second battery 36 disposed on the right traveling section 25R is located to the left of the right end of the right frame 18R.

[0182] In this way, by positioning the outer end of the second battery 36 arranged on the left running section 25L and / or the right running section 25R further inward than the outer end of the wheel 30 or the side frame 18LR, it is possible to prevent the width of the work vehicle 1 from increasing due to the positioning of the second battery 36.

[0183] As described above, the vehicle body 2 is raised and lowered by the height change mechanism (lifting mechanism) 90. Fig. 19 shows a state in which the vehicle body 2 has been raised to the second height by the height change mechanism (lifting mechanism) 90. Note that Fig. 19 is a diagram for explaining the arrangement of the first battery 35 and the second battery 36 when the vehicle body 2 is raised, and configurations that are not relevant to the explanation are omitted.

[0184] The height change mechanism 90 raises and lowers the first battery 35 together with the vehicle body 2. At this time, the second battery 36 does not raise or lower. In other words, the height change mechanism 90 raises and lowers only the first battery 35 of the first battery 35 and the second battery 36. Therefore, when the height change mechanism 90 raises the vehicle body 2, only the first battery 35 of the first battery 35 and the second battery 36 rises. In other words, only a part (the first battery 35) of the multiple batteries (the first battery 35 and the second battery 36) having the same function rises.

[0185] As shown in Fig. 19 , when the vehicle body 2 is raised (at the second height), the second battery 36 is located lower than the vehicle body 2 and the first battery 35. On the other hand, as shown in Fig. 16 , when the vehicle body 2 is lowered (at the first height), the vertical position of the second battery 36 overlaps with the vertical positions of the vehicle body 2 and the first battery 35. In this way, as the vehicle body 2 is raised or lowered, the vertical positional relationship between the first battery 35 and the second battery 36 changes between a state in which the vertical positions overlap (see Fig. 16 ) and a state in which the vertical positions do not overlap (see Fig. 19 ).

[0186] In this way, by changing the vertical positional relationship between the first battery 35 and the second battery 36, it is possible to arrange the first battery 35 and the second battery 36 apart in the vertical direction. This makes it possible to prevent heat generated from one of the first battery 35 and the second battery 36 from affecting the other battery.

[0187] As described above, in the work vehicle 1, multiple batteries (first battery 35 and second battery 36) having the same function are distributed among the vehicle body 2 and the left traveling section 25L and / or the right traveling section 25R, thereby reducing the weight of the vehicle body 2. In other words, the vehicle body 2 can be made lighter than when multiple batteries having the same function are all disposed in the vehicle body 2. As a result, the force required to raise the vehicle body 2 using the height change mechanism 90 can be reduced.

[0188] This makes it possible to reduce the size and weight of the lift cylinder 91 of the height change mechanism 90 and the hydraulic pump that supplies hydraulic oil to the lift cylinder 91. Because the hydraulic pump is mounted on the vehicle body 2, reducing the weight of the hydraulic pump also makes it possible to reduce the weight of the vehicle body 2. As a result, the weight of the work vehicle 1 can be reduced.

[0189] As described above, the second battery 36 is disposed on frames (first left frame 19L, first right frame 21R) that are movable in the left-right direction. Therefore, the positional relationship between the first battery 35 and the second battery 36 in the left-right direction can be changed by moving the frames (first left frame 19L, first right frame 21R). Therefore, the work vehicle 1 can not only change the positional relationship between the first battery 35 and the second battery 36 in the up-down direction, but also change their positional relationship in the left-right direction. In other words, the work vehicle 1 can move the first battery 35 and the second battery 36 in directions that are perpendicular to each other (up-down direction and left-right direction). In other words, the work vehicle 1 is equipped with mechanisms (height change mechanism 90, distance change mechanism 80) that can change the relative positional relationship between the first battery 35 and the second battery 36.

[0190] The second battery 36 is disposed on frames (first left frame 19L, first right frame 21R) that are movable in the left-right direction, and by moving the frames (first left frame 19L, first right frame 21R), the distance (left-right distance) between the second battery 36 and the vehicle body 2 can be changed. Therefore, it is possible to dispose the second battery 36 away from the vehicle body 2 to the side (left or right).

[0191] By locating the second battery 36 away from the vehicle body 2 to the side, access to the second battery 36 is facilitated, improving the ease of maintenance of the second battery 36. Furthermore, when the second battery 36 is located away from the vehicle body 2, the weight of the work vehicle 1 is distributed widely in the left-right direction, improving stability in the left-right direction. Therefore, for example, it is possible to reliably prevent the vehicle body 2 from tipping over when the vehicle body 2 is raised.

[0192] Furthermore, because the first battery 35 and the second battery 36 are heat-generating devices, distributing the first battery 35 and the second battery 36 among the vehicle body 2 and the left traveling section 25L and / or the right traveling section 25R can prevent the generated heat from concentrating (accumulating) locally. For example, if the first battery 35 and the second battery 36 that generate heat are both disposed in the vehicle body 2, or if the first battery 35 and the second battery 36 that generate heat are disposed as a single unit in the vehicle body 2, heat may concentrate locally inside the vehicle body 2. However, by distributing the second battery 36 among the left traveling section 25L and / or the right traveling section 25R rather than distributing it only in the vehicle body 2, heat concentration can be suppressed.

[0193] Furthermore, because the distance (left-right distance) between the first battery 35 and the second battery 36 can be changed, it is possible to position the second battery 36 at a distance to the side of the first battery 35. This makes it possible to prevent heat generated from one of the first battery 35 and the second battery 36 from affecting the other battery.

[0194] Furthermore, when the second battery 36 is disposed on both the left traveling section 25L and the right traveling section 25R, the distance (distance in the left-right direction) between the second battery 36 disposed on the left traveling section 25L and the second battery 36 disposed on the right traveling section 25R can be changed. This makes it possible to adjust the weight balance and center of gravity position of the work vehicle 1 in the left-right direction.

[0195] Furthermore, the frame structure 18 (see FIG. 8 , etc.) in which the second battery 36 is disposed has a framework structure made up of a combination of multiple frame members, etc., ensuring good ventilation. Therefore, by disposing the second battery 36 in the frame structure 18, the second battery 36 can be cooled (air-cooled) by the air passing through the frame structure 18. However, a configuration in which a cover is provided to cover the outside of the frame structure 18 can also be adopted.

[0196] In the case of the work vehicle 1 of the embodiment described above, some of the multiple batteries (first battery 35) were disposed in the vehicle body 2, but the work vehicle 1 can also employ an embodiment in which no battery is disposed in the vehicle body 2. Below, a work vehicle 1 of an embodiment in which no battery is disposed in the vehicle body 2 (referred to as the "second embodiment") will be described. In the description of the second embodiment, description of configurations common to the work vehicle 1 of the embodiment described above will be omitted.

[0197] 20 is a front view showing an example of a work vehicle 1 according to the second embodiment. In the work vehicle 1 according to the second embodiment, multiple batteries (a first battery 35, a second battery 36) having the same functions are arranged in the travel sections (the left travel section 25L and the right travel section 25R). Specifically, the first battery 35 is arranged in the left travel section 25L, and the second battery 36 is arranged in the right travel section 25R.

[0198] No battery is disposed in the vehicle body 2. That is, in the case of the work vehicle 1 of the second embodiment, multiple batteries (first battery 35, second battery 36) are disposed in the traveling sections (left traveling section 25L, right traveling section 25R), and are not disposed in the vehicle body 2.

[0199] The first battery 35 stores power for driving the left traveling unit 25L (more specifically, the left traveling device 3L). By disposing the first battery 35 in the left traveling unit 25L, it is possible to easily supply power from the first battery 35 to drive the left traveling device 3L. The second battery 36 stores power for driving the right traveling unit 25R (more specifically, the right traveling device 3R). By disposing the second battery 36 in the right traveling unit 25R, it is possible to easily supply power from the second battery 36 to drive the right traveling device 3R.

[0200] In the case of the work vehicle 1 of the second embodiment, multiple batteries (first battery 35 and second battery 36) are not arranged on the vehicle body 2, which allows for a reduction in the weight of the vehicle body 2. This prevents the weight of the multiple batteries (first battery 35 and second battery 36) from being concentrated on the vehicle body 2. Furthermore, by reducing the weight of the vehicle body 2, it is possible to reduce the force required to raise the vehicle body 2 using the height change mechanism 90.

[0201] Furthermore, in the case of the work vehicle 1 of the second embodiment, the multiple batteries (first battery 35 and second battery 36) are distributed between the left traveling section 25L and the right traveling section 25R, which improves the weight balance (particularly the weight balance in the left-right direction) of the work vehicle 1. Furthermore, it is possible to prevent heat generated by the batteries from accumulating in the vehicle body 2.

[0202] A preferred embodiment of the present invention provides a work vehicle 1 as described in the following items.

[0203] (Item 1) A vehicle comprising a vehicle body 2, a left running section 25L including a left running device 3L arranged on the left side of the vehicle body 2, a right running section 25R including a right running device 3R arranged on the right side of the vehicle body 2, and a plurality of batteries capable of storing electricity for driving the left running section 25L and the right running section 25R, at least one of the plurality of batteries being arranged on either the left running section 25L or the right running section 25R.

[0204] The weight balance of the vehicle can be improved with the work vehicle 1 according to this item 1. Specifically, since at least one of the multiple batteries is disposed on either the left traveling section 25L or the right traveling section 25R, it is possible to prevent the weight of the batteries from concentrating on the vehicle body 2, and it is possible to improve the weight balance of the work vehicle 1.

[0205] (Item 2) The work vehicle 1 described in Item 1, wherein the plurality of batteries include a first battery 35 used when driving or working, and a second battery 36 used when driving or working, the first battery 35 being disposed in the vehicle body 2, and the second battery 36 having the same function as the first battery 35 and disposed in at least one of the left traveling section 25L and the right traveling section 25R.

[0206] According to the work vehicle 1 relating to this item 2, the first battery 35 and the second battery 36, which have the same functions, are distributed across the vehicle body 2 and the running parts (at least one of the left running part 25L and the right running part 25R), which prevents the weight of the batteries from concentrating on the vehicle body 2 and enables the weight balance (left-right weight balance) of the work vehicle 1 to be improved.

[0207] (Item 3) The plurality of batteries include a first battery 35 used when driving or working, and a second battery 36 used when driving or working, the first battery 35 and the second battery 36 having the same function, the first battery 35 being disposed in the left traveling section 25L, and the second battery 36 being disposed in the right traveling section 25R, in the work vehicle 1 described in Item 1.

[0208] According to the work vehicle 1 relating to this item 3, the first battery 35 and the second battery 36, which have the same functions, are distributed across the left running section 25L and the right running section 25R, thereby preventing the weight of the batteries from concentrating on the vehicle body 2 and enabling the weight balance (left-right weight balance) of the work vehicle 1 to be better improved.

[0209] (Item 4) The work vehicle 1 according to Item 3, wherein the vehicle body 2 does not have the plurality of batteries disposed thereon.

[0210] According to the work vehicle 1 according to this item 4, the weight of the vehicle body 2 can be reduced by not disposing a battery in the vehicle body 2. Therefore, it is possible to prevent the weight from being concentrated on the vehicle body 2.

[0211] (Item 5) The work vehicle 1 according to Item 2, wherein the second battery 36 is disposed in the left traveling section 25L and the right traveling section 25R.

[0212] According to the work vehicle 1 relating to this item 5, the second battery 36 is distributed among the vehicle body 2, the left running section 25L, and the right running section 25R, which prevents the weight of the battery from concentrating on the vehicle body 2 and effectively improves the weight balance (left-right weight balance) of the work vehicle 1.

[0213] (Item 6) The work vehicle 1 according to Item 2, wherein the second battery 36 is disposed below at least one of the left traveling section 25L and the right traveling section 25R.

[0214] According to the work vehicle 1 relating to item 6, the center of gravity of at least one of the left running section 25L and the right running section 25R can be lowered, thereby lowering the center of gravity of the work vehicle 1, thereby enabling the work vehicle 1 to travel and work stably.

[0215] (Item 7) The work vehicle 1 according to Item 2, wherein the second battery 36 is disposed below the left traveling section 25L and below the right traveling section 25R.

[0216] According to the work vehicle 1 relating to item 7, the center of gravity of the left running section 25L and the right running section 25R is lowered, thereby lowering the center of gravity of the work vehicle 1, thereby enabling the work vehicle 1 to travel and work stably.

[0217] (Item 8) The left running section 25L includes a left front wheel 3LF and a left rear wheel 3LB, the right running section 25R includes a right front wheel 3RF and a right rear wheel 3RB, and the second battery 36 is disposed at least one of between the left front wheel 3LF and the left rear wheel 3LB and between the right front wheel 3RF and the right rear wheel 3RB in the work vehicle 1 described in Item 2.

[0218] According to the work vehicle 1 according to this item 8, the second battery 36 can be disposed by utilizing the space between the left front wheel 3LF and the left rear wheel 3LB, and / or the space between the right front wheel 3RF and the right rear wheel 3RB. Therefore, it is possible to prevent the width of the work vehicle 1 from increasing due to the disposition of the second battery 36. Furthermore, because wheels are located in front of and behind the second battery 36, the wheels can prevent foreign objects from colliding with the second battery 36 from the front or rear.

[0219] (Item 9) The left running section 25L includes a left front wheel 3LF and a left rear wheel 3LB, the right running section 25R includes a right front wheel 3RF and a right rear wheel 3RB, and the second battery 36 is disposed between the left front wheel 3LF and the left rear wheel 3LB, and between the right front wheel 3RF and the right rear wheel 3RB. This is the work vehicle 1 described in Item 2.

[0220] According to the work vehicle 1 according to this item 9, the space between the left front wheel 3LF and the left rear wheel 3LB, and the space between the right front wheel 3RF and the right rear wheel 3RB, can be utilized to place the second batteries 36 on the left and right sides of the vehicle body 2. Therefore, it is possible to place multiple second batteries 36 on the sides of the vehicle body 2 while preventing the arrangement of the second batteries 36 from causing the work vehicle 1 to expand in length in the width direction.

[0221] (Item 10) The work vehicle 1 according to any one of items 2 and 5 to 9, further comprising a lifting mechanism 90 that raises and lowers the vehicle body 2, and the lifting mechanism 90 raises and lowers the first battery 35 together with the vehicle body 2.

[0222] According to the work vehicle 1 according to this item 10, with the second battery 36 disposed on at least one of the left traveling section 25L and the right traveling section 25R, the first battery 35 moves up and down together with the vehicle body 2, thereby reducing the force required to raise and lower the vehicle body 2. As a result, the equipment required to raise and lower the vehicle body 2 can be made smaller and lighter.

[0223] (Item 11) A work vehicle 1 according to any one of items 1 to 10, comprising motors 5, 6 that generate the power required for traveling or working, and the first battery 35 and the second battery 36 being batteries 7 that store the power supplied to the motors 5, 6.

[0224] According to the work vehicle 1 according to this item 11, the battery 7, which is a heavy object, can be distributed among the vehicle body 2 and at least one of the left traveling section 25L and the right traveling section 25R. This prevents the weight of the battery, which is a heavy object, from concentrating on the vehicle body 2, and improves the weight balance of the work vehicle 1.

[0225] Although the embodiments of the present invention have been described above, the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0226] REFERENCE SIGNS LIST 1 Work vehicle 2 Vehicle body 3L Left traveling device 3LF Left front wheel 3LB Left rear wheel 3R Right traveling device 3RF Right front wheel 3RB Right rear wheel 5 Motor (travel system motor) 6 Motor (work system motor) 7 Battery 25L Left traveling section 25R Right traveling section 35 First battery 36 Second battery 90 Lifting mechanism

Claims

1. A work vehicle comprising a vehicle body, a left traveling unit including a left traveling device disposed on the left side of the vehicle body, a right traveling unit including a right traveling device disposed on the right side of the vehicle body, and a plurality of batteries capable of storing electric power for driving the left traveling unit and the right traveling unit, wherein at least one of the plurality of batteries is disposed in either the left traveling unit or the right traveling unit.

2. The work vehicle according to claim 1, wherein the plurality of batteries include a first battery used during traveling or working and a second battery used during traveling or working, the first battery is disposed on the vehicle body, and the second battery has the same function as the first battery and is disposed in at least one of the left traveling unit and the right traveling unit.

3. The work vehicle according to claim 1, wherein the plurality of batteries include a first battery used during traveling or working and a second battery used during traveling or working, the first battery and the second battery have the same function, the first battery is disposed in the left traveling unit, and the second battery is disposed in the right traveling unit.

4. The work vehicle according to claim 3, wherein the plurality of batteries are not disposed on the vehicle body.

5. The work vehicle according to claim 2, wherein the second battery is disposed in the left traveling unit and the right traveling unit.

6. The work vehicle according to claim 2, wherein the second battery is disposed in at least one of the lower part of the left traveling unit and the lower part of the right traveling unit.

7. The work vehicle according to claim 2, wherein the second battery is disposed in the lower part of the left traveling unit and the lower part of the right traveling unit.

8. The work vehicle according to claim 2, wherein the left traveling unit includes a left front wheel and a left rear wheel, the right traveling unit includes a right front wheel and a right rear wheel, and the second battery is disposed in at least one of the space between the left front wheel and the left rear wheel and the space between the right front wheel and the right rear wheel.

9. The work vehicle according to claim 2, wherein the left traveling unit includes a left front wheel and a left rear wheel, the right traveling unit includes a right front wheel and a right rear wheel, and the second battery is disposed between the left front wheel and the left rear wheel and between the right front wheel and the right rear wheel.

10. The work vehicle according to claim 2, further comprising a lifting mechanism for lifting and lowering the vehicle body, wherein the lifting mechanism lifts and lowers the first battery together with the vehicle body.

11. The work vehicle according to any one of claims 1 to 10, comprising a motor that generates power required during traveling or work, wherein the first battery and the second battery are batteries that store electric power supplied to the motor.

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