Work vehicle

Abstract

Provided is a work vehicle having excellent travel stability.　A work vehicle (1) comprises: a vehicle body (2) which is capable of traveling and to which a work device (U1) can be mounted; a tank (6) which stores a gas; a fuel cell (7) which generates power with the gas; and an electric motor (5) which is driven with power generated by the fuel cell, wherein the electric motor includes a first motor (5A) that generates a driving force for the vehicle body and a second motor (5B) that generates a driving force for the work device.

Description

Work vehicle

[0001] The present invention relates to a work vehicle equipped with a fuel cell.

[0002] In recent years, in order to achieve decarbonization, the development of work vehicles driven by electric power generated by fuel cells has been progressing. The work vehicle (tractor) disclosed in Patent Document 1 includes a tank for storing hydrogen gas, a fuel cell, and an electric motor, and drives and runs the motor with the electric power generated by the fuel cell. For this type of work vehicle, in order to maintain stable output over a long period of time, it is required to mount multiple tanks or increase the size.

[0003] Japanese Patent Publication "JP-A-2024-095109"

[0004] By the way, when this type of work vehicle is used with a work device such as a cultivator or a mower attached, it requires greater power. However, in order to secure the above power, if the electric motor is enlarged, depending on the layout configuration of the electric motor and other heavy objects such as a hydrogen tank, the weight balance of the entire vehicle may be impaired, leading to a decrease in running stability.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a work vehicle having excellent running stability.

[0006] The present invention employs the following technical means to achieve the above object.

[0007] A work vehicle according to an aspect of the present invention includes a vehicle body capable of traveling and mounting a work device, a tank for storing gas, a fuel cell that generates electricity using the gas, and an electric motor driven by the electric power generated by the fuel cell. The electric motor includes a first motor that generates the driving force of the vehicle body and a second motor that generates the driving force of the work device.

[0008] According to the present invention, since the power required for the vehicle to travel and the power of the work device when used with the work device attached can be secured separately, a work vehicle having excellent running stability can be provided.

[0009] This is a schematic diagram of a positioning support system. This is a perspective view of a work vehicle according to an embodiment of the present invention. This is a top view of a work vehicle according to an embodiment of the present invention. This is a side view of a work vehicle according to an embodiment of the present invention. This is a front view of a work vehicle according to an embodiment of the present invention. This is a rear view of a work vehicle according to an embodiment of the present invention. This is a partially exploded perspective view of a work vehicle according to an embodiment of the present invention. This is a block diagram showing the basic configuration of a work vehicle according to an embodiment of the present invention. This is a perspective view showing the vehicle frame and its surrounding parts. This is a partially exploded perspective view showing the vehicle frame and its surrounding parts. This is a perspective view of the vehicle frame. This is a top view of the vehicle frame. This is a perspective view of the power transmission device. This is a top view of the power transmission device. This is a top view showing the internal structure of the power transmission device. This is a schematic configuration diagram of the power transmission device. This is a schematic configuration diagram of the battery unit. This is a block diagram showing the basic configuration of a work vehicle according to a first modified example. This is a top view of a work vehicle according to a first modified example. This is a perspective view of the power transmission device according to a first modified example. This is a front view of the area around the electric motor according to a first modified example. This is a front view of the area around the electric motor according to a second modified example. This is a front view of the area around the electric motor according to a third modified example. This is a front view of the area around the electric motor according to a fourth modified example. This is a perspective view of the power transmission device according to a fifth modified example. This is a side view of the power transmission device of the fifth modified example. This is a front view of the area around the electric motor of the fifth modified example. This is a top view of the power transmission device of the sixth modified example.

[0010] Embodiments of the present invention will be described with reference to the drawings. The work vehicle 1 of this embodiment is a type of FCV (Fuel Cell Vehicle) driven by electricity generated by a fuel cell, and can be used by connecting work implements U1 such as tillers, mowers, seeders, spreaders, and balers, mainly according to the purpose and use of agricultural work (see Figure 3). However, the work vehicle 1 according to the present invention is not limited to agricultural work vehicles. For example, the work vehicle 1 according to the present invention may be a construction work vehicle, a material transport vehicle, a utility vehicle, etc.

[0011] As shown in Figure 1, the work vehicle 1 of this embodiment is an autonomous vehicle that drives autonomously based on the position information of the work vehicle 1 acquired from the positioning support system S, obstacle detection information from the object sensor 95, etc. In addition to the autonomous driving function described above, or alternatively, the work vehicle 1 may also be equipped with a remote control function that allows it to be driven manually by commands from a remote control device RC.

[0012] The work vehicle 1 of this embodiment includes a control device 90, a positioning device 91, and a work information communication device 93. Based on an operation program set in advance by the user, the control device 90 sets a target travel route from information about the target field, etc., and controls the movement of the vehicle body 2 to follow the target travel route using the position information (positioning information) of the work vehicle 1 acquired from the positioning support system S.

[0013] The positioning support system S comprises a positioning base station S1 and a support device S2. Multiple positioning base stations S1 are installed at predetermined reference points such as building roofs and around fields, and transmit satellite signals received from positioning satellites G to the support device S2 via an external communication network N. The support device S2 is a fixed computer terminal (server) installed at agricultural machinery manufacturers, agricultural cooperatives, positioning support system management companies, etc., and transmits observation information based on satellite signals received from the positioning base stations S1 to the outside via the external communication network N.

[0014] The positioning device 91 acquires position information (positioning information including latitude and longitude) from satellite positioning systems such as GPS (Global Positioning System), GLONASS (Global Navigation Satellite System), Michibiki (QZSS: Quasi-Zenith Satellite System), Galileo, and Beidou. The positioning device 91 receives satellite signals (positioning information such as the position of the positioning satellite G and the transmission time) transmitted from the positioning satellite G, and detects the position of the work vehicle 1 (for example, latitude and longitude) based on the satellite signals.

[0015] The work information communication device 93 is a field management communication device that wirelessly connects to an external communication network N and transmits positioning information (vehicle position), operation information of the work vehicle 1, operation information of the work device U1 connected to the work vehicle 1, etc., to the field management device T. The work information communication device 93 in this embodiment is a communication unit that can wirelessly connect to an external communication network N via a communication base station such as a telephone communication network of a telephone line operator or a data communication network of an internet line operator, and transmits positioning information and operation information to the field management device T via the external communication network N.

[0016] The work vehicle 1 may be equipped with a remote communication device 94. The remote communication device 94 is a communication device for remote operation that receives radio waves emitted from the remote control device RC and acquires operation information (operation command information) for the remote control device RC. The remote communication device 94 is wired to the control device 90 and transmits the operation information to the control device 90.

[0017] The work vehicle 1 is equipped with an object sensor 95. The control device 90 controls the movement of the vehicle body 2 based on the detection information from the object sensor 95. In this embodiment, the object sensor 95 is an imaging device that photographs the area around the work vehicle 1 and transmits the captured image to the control device 90. Based on the image, the control device 90 detects whether or not there are any objects around the work vehicle 1 that would obstruct its movement.

[0018] In this embodiment, the work vehicle 1 uses imaging devices such as a CCD (Charge Coupled Devices) camera, a CMOS (Complementary Metal Oxide Semiconductor) camera, or an infrared camera as the object sensor 95. However, the object sensor 95 is not limited to imaging devices as long as it can accurately detect the presence or absence of objects around the work vehicle 1.

[0019] For example, the object sensor 95 may be a laser sensor (LiDAR: Light Detection And Ranging) that irradiates laser light around the work vehicle 1 and measures the distance and position of an object based on the detection information of the reflected light. Alternatively, the object sensor 95 may be a millimeter-wave radar that irradiates radio waves around the work vehicle 1 and measures the distance and position of an object based on the detection information of the reflected waves.

[0020] The work vehicle 1 may be equipped with two or more sensors as object sensors 95, selected from an imaging device, a laser sensor, and a millimeter-wave radar, and may be configured to detect objects around the work vehicle 1 in combination with these multiple types of sensors.

[0021] The control device 90 is an ECU (Electronic Control Unit) and controls the running gear 3, power supply device 4, electric motor 5, etc. The control device 90 controls the movement of the vehicle body 2 based on information from the positioning device 91, work information communication device 93, object sensor 95, etc.

[0022] In more detail, the control device 90 sets a target travel path for the work vehicle 1 based on positioning information acquired by the positioning device 91. The control device 90 controls the steering direction of the travel device 3, the output of the electric motor 5, etc., according to the target travel path. In this way, the control device 90 autonomously controls the movement of the vehicle body 2.

[0023] The control device 90 may control the steering direction of the driving device 3, the output of the electric motor 5, the operation of the braking device 2E, etc., based on the operation information acquired by the remote communication device 94. In other words, the control device 90 may control the movement of the vehicle body 2 by command (remote control) from the remote control device RC. This allows the operator to remotely control the movement of the vehicle body 2 using the remote control device RC.

[0024] The control device 90 of this embodiment combines an autonomous driving function that controls the movement of the vehicle body 2 autonomously and a remote control function that controls the movement of the vehicle body 2 remotely. However, the control device 90 is not limited to having both the autonomous driving function and the remote control function. For example, the control device 90 may have only one of the autonomous driving function or the remote control function.

[0025] The control device 90 analyzes whether or not there are obstacles around the work vehicle 1 based on the detection information (image information) from the object sensor 95. The control device 90 restricts the operation of the work vehicle 1 according to the results of the image information analysis.

[0026] For example, if the control device 90 detects a person or an obstacle (object) that would hinder movement on the target driving path using the object sensor 95 during autonomous driving, and the distance from the obstacle to the work vehicle 1 is below a predetermined value, the control device 90 reduces the output of the electric motor 5 and activates the braking device 2E mounted on the vehicle body 2 to stop the work vehicle 1.

[0027] Furthermore, if the object sensor 95 is a laser sensor or millimeter-wave radar, the control device 90 analyzes whether or not there are obstacles around the work vehicle 1 based on the detection information (input information) from the laser sensor or millimeter-wave radar, instead of image information. The control device 90 then performs the same stopping operation on the work vehicle 1 as described above, according to the results of the analysis of the input information.

[0028] In the following explanation, the longitudinal direction of the vehicle body 2, which is the direction of straight-line travel of the work vehicle 1 (indicated by arrows X1 and X2 in Figures 2 to 4), will be referred to as the front-rear direction, the width direction of the vehicle body 2 (indicated by arrows Y1 and Y2 in Figures 2, 3, 5, and 6), will be referred to as the left-right direction, and the height direction of the vehicle body 2 (indicated by arrows Z1 and Z2 in Figures 2, 4 to 6), will be referred to as the up-down direction. Furthermore, in each figure, the direction indicated by arrow X1 will be referred to as the front, the direction indicated by arrow X2 as the rear, the direction indicated by arrow Y1 as the left, the direction indicated by arrow Y2 as the right, the direction indicated by arrow Z1 as the up, and the direction indicated by arrow Z2 as the down.

[0029] As shown in Figures 2 to 6, the work vehicle 1 comprises a vehicle body 2 and a running gear 3. The running gear 3 supports the vehicle body 2 so that it can move. That is, the work vehicle 1 has a vehicle body 2 that can move. The running gear 3 in this embodiment includes front wheels 3F as a front running gear that supports the front of the vehicle body 2, and rear wheels 3R ​​as a rear running gear that supports the rear of the vehicle body 2.

[0030] Furthermore, the running gear 3 is not limited to wheels. For example, the running gear 3 may be a crawler. Also, of the running gear 3 that supports the front and rear of the vehicle body 2, one may be wheels and the other may be a crawler.

[0031] As shown in Figures 4, 7, and 8, the work vehicle 1 is equipped with a power supply device 4, an electric motor 5, and a power transmission device 20. The power supply device 4 includes a hydrogen tank (tank) 6, a fuel cell stack (fuel cell) 7, and a battery unit (battery) 8. In other words, the power supply device 4 is a device for supplying power to the electric motor 5 and the like.

[0032] The hydrogen tank 6 stores hydrogen gas. The fuel cell stack 7 generates electricity using the hydrogen gas supplied from the hydrogen tank 6 and supplies it to the electric motor 5. The battery unit 8 stores the electricity generated by the fuel cell stack 7 and supplies it to the electric motor 5 as needed. The electric motor 5 is driven by the electricity supplied from the fuel cell stack 7 and the battery unit 8. The power transmission device 20 transmits the power from the electric motor 5 to the traction device 3.

[0033] As shown in Figure 8, the work vehicle 1 is equipped with a hydraulic pump 9. The work vehicle 1 may also be equipped with a radiator device 61. The work vehicle 1 may further be equipped with an inverter 62 and a DC / DC converter 63.

[0034] The radiator system 61 is a cooler that cools the coolant (refrigerant) circulated to equipment such as the electric motor 5, fuel cell stack 7, inverter 62, and DC / DC converter 63 by heat exchange with the outside air. The radiator system 61 includes a first radiator system 66 and a second radiator system 67.

[0035] The first radiator unit 66 is connected to the electric motor 5, inverter 62, DC / DC converter 63, and boost circuit BC via a first coolant flow path FP1, and cools the coolant circulating through the first coolant flow path FP1 by heat exchange with the outside air. As a result, the electric motor 5, inverter 62, DC / DC converter 63, and boost circuit BC are maintained at a predetermined temperature or below.

[0036] The first radiator unit 66 is housed inside the rear bonnet 15B. The fuel cell stack 7, inverter 62, DC / DC converter 63, and boost circuit BC are also housed inside the rear bonnet 15B, similar to the first radiator unit 66.

[0037] The first radiator device 66 includes a first heat exchange section 71 and a first fan 72. The first heat exchange section 71 is a gas-liquid heat exchanger composed of a plurality of heat transfer fins and heat transfer tubes, and is connected to a first coolant flow path FP1. The first fan 72 circulates air over the surface of the first heat exchange section 71, promoting heat exchange between the air and the coolant flowing inside the first heat exchange section 71. The first radiator device 66 may have only one first fan 72, or it may have two or more first fans 72.

[0038] The first fan 72, when driven, draws air from outside the rear bonnet 15B into the rear bonnet 15B. The air drawn into the rear bonnet 15B by the first fan 72, as described above, passes through the first heat exchange unit 71, then passes around the fuel cell stack 7, inverter 62, and DC / DC converter 63, and is discharged to the outside of the rear bonnet 15B. As a result, the coolant flowing through the first heat exchange unit 71 is cooled efficiently. The air that has passed through the first heat exchange unit 71 also promotes the cooling of the fuel cell stack 7, inverter 62, and DC / DC converter 63.

[0039] The second radiator device 67 is connected to the fuel cell stack 7 via a second coolant flow path FP2, and cools the coolant circulating through the second coolant flow path FP2 by heat exchange with the outside air. As a result, the internal electrodes of the fuel cell stack 7 are maintained at a predetermined temperature or below. Consequently, the fuel cell stack 7 maintains a high power generation efficiency.

[0040] The second radiator unit 67 is housed inside the front bonnet 15A. The hydrogen tank 6 and battery unit 8 are also housed inside the front bonnet 15A, similar to the second radiator unit 67.

[0041] The second radiator device 67 includes a second heat exchange section 73 and a second fan 74. The second heat exchange section 73 is a gas-liquid heat exchanger composed of a plurality of heat transfer fins and heat transfer tubes, and is connected to the second coolant flow path FP2. The second fan 74 circulates air over the surface of the second heat exchange section 73, promoting heat exchange between the air and the coolant flowing inside the second heat exchange section 73. The second radiator device 67 may have only one second fan 74, or it may have two or more second fans 74.

[0042] The second fan 74, when driven, draws air from outside the front bonnet 15A into the front bonnet 15A. The air drawn into the front bonnet 15A by the second fan 74, as described above, passes through the second heat exchange section 73, then passes around the hydrogen tank 6 and battery unit 8, and is discharged to the outside of the front bonnet 15A. As a result, the coolant flowing through the second heat exchange section 73 is cooled efficiently. The air that has passed through the second heat exchange section 73 also promotes the cooling of the hydrogen tank 6 and battery unit 8.

[0043] As shown in Figures 3, 4, and 6, the work vehicle 1 is equipped with a coupling device 60. The coupling device 60 is located at the rear of the vehicle body 2 and connects to and supports the work device U1. That is, the work vehicle 1 is equipped with a vehicle body 2 that is drivable and capable of mounting the work device U1. In this embodiment, the coupling device 60 is a three-point linkage mechanism that connects to and raises the work device U1. The coupling device 60 has a hydraulic cylinder for raising and lowering the work device U1.

[0044] As shown in Figures 9 to 11, the vehicle body 2 has a vehicle body frame 10. The vehicle body frame 10 includes a front frame 11 and a transmission case 12. As shown in Figures 11 and 12, the vehicle body frame 10 may further include a central frame 13. The front frame 11 constitutes the front part of the vehicle body frame 10. The transmission case 12 constitutes the rear part of the vehicle body 2. The central frame 13 is provided between the front and rear of the front frame 11 and the transmission case 12, and connects the front frame 11 and the transmission case 12. That is, the central frame 13 constitutes the base frame in the center between the front and rear of the vehicle body 2.

[0045] As shown in FIGS. 9 to 12, the front frame 11 has a left frame 11L and a right frame 11R. The left frame 11L constitutes the left side portion of the front frame 11. The right frame 11R constitutes the right side portion of the front frame 11.

[0046] Both the left frame 11L and the right frame 11R are plate-shaped frames that are long in the front-rear direction, and are arranged side by side facing each other in the left-right direction. A predetermined interval H1 is defined between the left and right of the left frame 11L and the right frame 11R. That is, the left frame 11L and the right frame 11R are arranged side by side with a predetermined interval H1 in the left-right direction. The battery unit 8 is accommodated in the interval H1. That is, the battery unit 8 is provided at the front portion of the vehicle body 2. Details of the battery unit 8 will be described later.

[0047] As shown in FIG. 12, the front frame 11 has a front axle case 11C. The front axle case 11C houses the front axle 3FD. The front axle 3FD is connected to the left and right front wheels 3F and transmits the power of the electric motor 5 to the front wheels 3F. As shown in FIGS. 5 and 10 to 12, the front axle case 11C is continuously provided at the lower portion of the front frame 11. The front frame 11 is supported from below by the front wheels 3F via the front axle case 11C. Thus, the front wheels 3F are supported by the front frame 11.

[0048] As shown in FIGS. 12 to 14, the power transmission device 20 has a transmission case 12 and a drive train 21. The transmission case 12 is the housing of the power transmission device 20. As shown in FIG. 14, the drive train 21 is accommodated inside the transmission case 12. Details of the drive train 21 will be described later.

[0049] As shown in Figures 13 to 15, the transmission case 12 may be configured by dividing it into multiple parts. The transmission case 12 in this embodiment includes a rear case 12A and a mid case 12B. The mid case 12B is formed in an irregularly shaped cylindrical form that opens in the front-to-rear direction. The rear case 12A is connected to the rear of the mid case 12B. The internal space of the mid case 12B is in communication with the internal space of the rear case 12A.

[0050] The transmission case 12 may include a rear axle case 12C. The rear axle case 12C extends outward from the side of the transmission case 12 and houses the rear axle 3RD. The rear axle 3RD is connected to the left and right rear wheels 3R ​​and transmits power from the electric motor 5 to the rear wheels 3R. As shown in Figure 12, the transmission case 12 is supported laterally by the rear wheels 3R ​​via the rear axle case 12C. In this way, the rear wheels 3R ​​are supported by the transmission case 12.

[0051] As shown in Figures 11 and 12, the central frame 13 has a rectangular box-shaped frame structure. The electric motor 5 is incorporated into the space inside the central frame 13. The central frame 13 has a connecting bracket 13B. The central frame 13 is connected to the front of the mid-case 12B via the connecting bracket 13B. The electric motor 5 is connected to the front of the connecting bracket 13B. The electric motor 5 is connected to the front of the transmission case 12 via the connecting bracket 13B. Details of the electric motor 5 will be described later.

[0052] As shown in Figures 9 and 10, the vehicle body 2 may have a support frame 14. The support frame 14 in this embodiment has a frame structure that is long in the front-rear direction. The support frame 14 is provided on the upper part of the vehicle body frame 10. The support frame 14 in this embodiment extends from the front part of the front frame 11 to the rear part of the transmission case 12.

[0053] The support frame 14 includes a front support frame 14A and a rear support frame 14B. The front support frame 14A is connected and supported to the upper part of the front frame 11. The rear support frame 14B is connected and supported to the upper part of the transmission case 12.

[0054] The rear support frame 14B may have a support base portion 14C. The support base portion 14C has a rectangular box-shaped frame structure. As shown in Figure 4, the fuel cell stack 7 is supported on the upper part of the support base portion 14C. The fuel cell stack 7 is supported on the upper part of the transmission case 12 via the support frame 14. That is, the fuel cell stack 7 is located at the rear of the vehicle body 2. Details of the fuel cell stack 7 will be described later.

[0055] As shown in Figures 2 to 7, the vehicle body 2 has a bonnet 15. The bonnet 15 is a cover member that covers the equipment mounted on the upper part of the vehicle body 2. The bonnet 15 may be composed of multiple parts. In this embodiment, the bonnet 15 includes a front bonnet 15A and a rear bonnet 15B. The front bonnet 15A is provided on the upper part of the front frame 11. The rear bonnet 15B is provided on the upper part of the transmission case 12.

[0056] As shown in Figures 2 to 4 and Figure 7, the vehicle body 2 has a tank frame 16. The tank frame 16 is formed in a roughly rectangular box shape by a plurality of frames and plate materials. The tank frame 16 is connected and supported to the upper part of the front support frame 14A. The hydrogen tank 6 is housed inside the tank frame 16 and is supported to the upper part of the front frame 11 via the tank frame 16. In other words, the hydrogen tank 6 is located at the front of the vehicle body 2. Details of the hydrogen tank 6 will be described later.

[0057] As shown in Figures 8 and 15, the hydraulic pump 9 is connected to the power transmission device 20. The hydraulic pump 9 is connected to the rear of the mid-case 12B and is rotationally driven by the power of the electric motor 5 transmitted from the power transmission device 20. The hydraulic drive system, which includes the hydraulic cylinder for steering the running gear 3 and the hydraulic cylinder for driving the coupling device 60, is connected to the hydraulic pump 9 through a hydraulic circuit and is driven by the hydraulic fluid (pressurized oil) discharged from the hydraulic pump 9.

[0058] As shown in Figures 6, 8, 14, and 15, the vehicle body 2 has a PTO shaft (power take-off shaft) 2D. The PTO shaft 2D is located at the rear of the power transmission device 20 and is rotationally driven by the power of the electric motor 5 transmitted from the power transmission device 20. When the working device U1 is connected to the coupling device 60 (see Figure 6), the PTO shaft 2D is connected to the passive shaft of the working device U1 via a universal joint. The power of the electric motor 5 is transmitted from the PTO shaft 2D to the passive shaft of the working device U1 via the universal joint. In other words, the working device U1 is driven by the power of the electric motor 5.

[0059] The electric motor 5 is, for example, a three-phase AC synchronous motor with embedded permanent magnets. However, the electric motor 5 is not limited to a three-phase AC synchronous motor. For example, the electric motor 5 may be a synchronous motor in which coils are wound around a rotor and laminated steel plates are fitted to it. The electric motor 5 is not limited to an AC motor, but may also be a DC motor.

[0060] As shown in Figures 2 to 4 and Figures 8 to 15, the electric motor 5 includes a first motor 5A and a second motor 5B. The first motor 5A is a drive system motor that drives the travel device 3. That is, the first motor 5A generates the driving force for the vehicle body 2. The second motor 5B is a work system motor that drives the PTO shaft 2D. That is, the second motor 5B generates the driving force for the work device U1. The power transmission device 20 is configured to transmit the power of the second motor 5B to the PTO shaft 2D and also to the hydraulic pump 9.

[0061] As shown in Figures 3 and 4, both the first motor 5A and the second motor 5B are positioned in the center between the front and rear of the vehicle body 2. In this embodiment, both the first motor 5A and the second motor 5B are positioned in the center between the front and rear of the front wheel 3F and the rear wheel 3R.

[0062] The hydrogen tank 6 is located above the first motor 5A and the second motor 5B. That is, the first motor 5A and the second motor 5B are located below the hydrogen tank 6. The fuel cell stack 7 is located above and behind the first motor 5A and the second motor 5B. That is, the first motor 5A and the second motor 5B are located below and in front of the fuel cell stack 7. The battery unit 8 is located in front of the first motor 5A and the second motor 5B. That is, the first motor 5A and the second motor 5B are located behind the battery unit 8.

[0063] As shown in Figure 14, the first motor 5A and the second motor 5B are arranged side by side at the front of the transmission case 12. More specifically, the first motor 5A and the second motor 5B are arranged side by side on either side of the X-axis centerline CL1, which passes through the center between the left and right sides of the vehicle body 2 when viewed from above.

[0064] In this embodiment, the first motor 5A and the second motor 5B use the same motor. The first motor 5A and the second motor 5B are positioned at equal distances from the X-axis centerline CL1 in the left-right direction. As a result, the weights of the first motor 5A and the second motor 5B are added equally to the vehicle body 2 on both sides of the X-axis centerline CL1. Thus, the overall weight balance of the work vehicle 1 is stabilized.

[0065] The power transmission device 20 is a device that reduces or increases the speed of the electric motor 5 and transmits it to the running gear 3. The power transmission device 20 is configured to transmit power not only to the running gear 3 but also to the hydraulic pump 9 and the PTO shaft 2D.

[0066] The power transmission device 20 of this embodiment is configured to be switchable between a two-wheel drive state in which the power of the electric motor 5 is transmitted only to the rear wheels 3R ​​of the running gear 3, and a four-wheel drive state in which the power of the electric motor 5 is transmitted to both the front wheels 3F and the rear wheels 3R. That is, the work vehicle 1 of this embodiment is a four-wheel drive vehicle capable of running with both the front wheels 3F and the rear wheels 3R ​​as drive wheels, and is configured to be able to be arbitrarily switched to a two-wheel drive vehicle state in which only the rear wheels 3R ​​are driven wheels, in response to an operation program set in advance by the user or a command from the remote control device RC. Note that the work vehicle 1 may be a two-wheel drive vehicle that runs with only the front wheels 3F as drive wheels, or a two-wheel drive vehicle that runs with only the rear wheels 3R ​​as drive wheels.

[0067] As shown in Figure 15, the power transmission device 20 comprises a transmission case 12 and a drivetrain 21. The transmission case 12 is a housing that accommodates the drivetrain 21, as described above. As shown in Figure 16, the drivetrain 21 includes a power transmission shaft 22, a gear device 23, a clutch device 24, and a differential 25.

[0068] The power transmission shaft 22 connects the output shaft of the electric motor 5 to the rear axle 3RD, the PTO shaft 2D, the input shaft of the hydraulic pump 9, etc. The gear device 23 transmits power between two shafts, such as the power transmission shaft 22. The clutch device 24 connects and disconnects two shafts, such as the power transmission shaft 22. The differential device 25 distributes and transmits the power of the electric motor 5 to the left and right sides of the axle 3D. As shown in Figures 12 and 16, the axle 3D includes the rear axle 3RD and the front axle 3FD.

[0069] As shown in Figure 15, the power transmission shaft 22 includes a first input shaft 31, a second input shaft 32, a rear wheel drive shaft 33, and a PTO connecting shaft 34. The power transmission shaft 22 may also include a propeller shaft 35 and a front wheel drive shaft 36.

[0070] The first input shaft 31 connects the output shaft of the first motor 5A to the rear wheel drive shaft 33. The second input shaft 32 connects the output shaft of the second motor 5B to the input shaft of the hydraulic pump 9. The rear wheel drive shaft 33 connects the first input shaft 31 to the rear axle 3RD. The PTO connecting shaft 34 connects the second input shaft 32 to the PTO shaft 2D.

[0071] The gear device 23 includes a first link gear 41 and a speed change gear 42. The gear device 23 may also include a branch gear 43. The gear device 23 may also include a second link gear 44. The gear device 23 may also include a third link gear 45.

[0072] The first link gear 41 transmits the rotation of the output shaft of the first motor 5A to the first input shaft 31. The speed change gear 42 reduces or increases the rotation of the first input shaft 31 and transmits it to the rear wheel drive shaft 33. The branch gear 43 transmits the rotation of the second input shaft 32, which is connected to the output shaft of the second motor 5B, to the PTO connecting shaft 34. The second link gear 44 transmits the rotation of the PTO connecting shaft 34 to the PTO shaft 2D. The third link gear 45 transmits the rotation of the rear wheel drive shaft 33 to the propeller shaft 35.

[0073] The clutch device 24 may be, for example, a meshing clutch. However, the clutch device 24 is not limited to a meshing clutch. For example, the clutch device 24 may be a friction clutch. The clutch device 24 may include a speed switching clutch 46. The clutch device 24 may also include an output switching clutch 47. The clutch device 24 may also include a drive switching clutch 48.

[0074] The rear wheel drive shaft 33, PTO connecting shaft 34, second link gear 44, and speed switching clutch 46 are housed inside the rear case 12A. The first input shaft 31, second input shaft 32, transmission gear 42, branch gear 43, and third link gear 45 are housed inside the mid case 12B.

[0075] The speed switching clutch 46 is incorporated into the transmission gear 42 and switches the rotational speed of the rear wheel drive shaft 33 between high speed and low speed. Therefore, by switching the speed switching clutch 46 to high speed, the work vehicle 1 can run in a high-speed mode in which the rotation of the first motor 5A is transmitted to the rear wheel 3R at a high speed. Also, by switching the speed switching clutch 46 to low speed, the work vehicle 1 can run in a low-speed mode in which the rotation of the first motor 5A is transmitted to the rear wheel 3R at a low speed.

[0076] The output switching clutch 47 is interposed between the branching gear 43 and the PTO connecting shaft 34, and connects or disconnects the second input shaft 32 to the PTO connecting shaft 34. Therefore, the work vehicle 1 transmits power from the second motor 5B to the PTO shaft 2D by engaging the output switching clutch 47, thereby operating the PTO shaft 2D. Conversely, the work vehicle 1 cuts off the transmission of power from the second motor 5B to the PTO shaft 2D by disengaging the output switching clutch 47, thereby stopping the PTO shaft 2D.

[0077] The drive switching clutch 48 is interposed between the propeller shaft 35 and the front wheel drive shaft 36, and connects or disconnects the propeller shaft 35 from the front wheel drive shaft 36. Therefore, by engaging the drive switching clutch 48, the work vehicle 1 becomes capable of driving in four-wheel drive mode. Conversely, by disengaging the drive switching clutch 48, the work vehicle 1 becomes capable of driving in rear-wheel drive (two-wheel drive) mode.

[0078] The differential gear 25 includes a rear differential gear 49R. The differential gear 25 may also include a front differential gear 49F. The rear differential gear 49R is interposed between the rear drive shaft 33 and the rear axle 3RD, and distributes the power of the electric motor 5 to the left and right of the rear axle 3RD and transmits it to the rear wheels 3R. The front differential gear 49F is interposed between the front drive shaft 36 and the front axle 3FD, and when the drive switching clutch 48 is engaged, distributes the power of the electric motor 5 to the left and right of the front axle 3FD and transmits it to the front wheels 3F.

[0079] As described above, the first motor 5A is connected to the first input shaft 31 of the power transmission device 20 and rotates the rear wheel drive shaft 33. The first motor 5A also rotates the front wheel drive shaft 36 when the drive switching clutch 48 is engaged. On the other hand, the second motor 5B is connected to the second input shaft 32 of the power transmission device 20 and rotates the hydraulic pump 9. The second motor 5B also rotates the PTO shaft 2D when the output switching clutch 47 is engaged.

[0080] As shown in Figures 2 to 5, the hydrogen tank 6 is a roughly cylindrical container that stores hydrogen gas under high pressure. The hydrogen tank 6 is made of, for example, a rigid synthetic resin reinforced with carbon fiber or glass fiber. As shown in Figure 8, the work vehicle 1 is equipped with a gas filling port (receptacle) 2G and a valve device V1.

[0081] The hydrogen tank 6 is connected to a gas supply unit installed at a hydrogen gas station via a gas filling port 2G, and hydrogen gas is filled into the hydrogen tank 6 through a valve device V1 via the gas filling port 2G and stored in the hydrogen tank 6. The valve device V1 consists of an on-off valve, a pressure reducing valve, a check valve, etc., and introduces the hydrogen gas injected into the gas filling port 2G into the hydrogen tank 6. The valve device V1 adjusts the hydrogen gas in the hydrogen tank 6 to a predetermined flow rate and then leads it out to the fuel cell stack 7. In addition, the hydrogen tank 6 may be configured to be replaced with another hydrogen tank 6 that is pre-filled with hydrogen gas when the amount of hydrogen gas stored becomes low, rather than being replenished with hydrogen gas from the gas filling port 2G as described above.

[0082] As shown in Figures 2 to 5, the hydrogen tank 6 is located at the front of the vehicle body 2. The hydrogen tank 6 is positioned on top of the front frame 11 and is covered by the front bonnet 15A together with the tank frame 16. In other words, the hydrogen tank 6 is housed inside the front bonnet 15A.

[0083] The work vehicle 1 of this embodiment is equipped with two hydrogen tanks 6. These two hydrogen tanks 6 are installed side by side on the front of the vehicle body 2. Note that more than two hydrogen tanks 6 may be mounted on the vehicle body 2. For example, three hydrogen tanks 6 may be installed side by side on the front of the vehicle body 2, or four hydrogen tanks 6 may be installed in a 2x2 arrangement vertically and horizontally on the front of the vehicle body 2.

[0084] The fuel cell stack 7 generates electricity using hydrogen gas supplied from the hydrogen tank 6 and supplies power to the electric motor 5. The fuel cell stack 7 is composed of multiple single cells, each equipped with two types of electrodes, a positive electrode and a negative electrode, arranged in a stacked configuration inside a casing. By aggregating the electricity generated by each single cell, it generates the voltage and current power required to drive the electric motor 5.

[0085] As shown in Figure 8, the fuel cell stack 7 is connected to the inverter 62 and battery unit 8 via a boost circuit BC. The boost circuit BC increases the voltage of the power generated by the fuel cell stack 7. That is, the fuel cell stack 7 supplies the power increased by the boost circuit BC to the inverter 62 and battery unit 8. The inverter 62 is connected to the electric motor 5 and converts the DC power input from the boost circuit BC into three-phase AC power, which is then output to the electric motor 5. In this way, the fuel cell stack 7 drives the electric motor 5 with the power increased by the boost circuit BC.

[0086] The fuel cell stack 7 is connected to low-voltage devices that operate at a lower voltage than the electric motor 5 via a step-down circuit. The step-down circuit is a DC / DC converter 63. In this embodiment, the low-voltage devices include a first fan 72, a second fan 74 of the radiator device 61, and a battery unit 8. The DC / DC converter 63 converts the voltage of the DC power input from the fuel cell stack 7 to an even lower voltage and outputs it to each of the low-voltage devices. In this way, the fuel cell stack 7 supplies power stepped down by the DC / DC converter 63 to each of the low-voltage devices.

[0087] The battery unit 8 is a rechargeable secondary battery that stores power supplied from the fuel cell stack 7 and outputs the stored power to the inverter 62 or the like as needed. As shown in Figure 17, the battery unit 8 has a plurality of battery modules 8A and a battery case 80.

[0088] The battery module 8A is composed of lithium-ion batteries, lead-acid batteries, etc. The battery case 80 houses multiple battery modules 8A arranged in the front-to-back, left-to-right, and up-to-down directions. Thus, the battery unit 8 is a battery pack that is integrally constructed by housing multiple battery modules 8A inside the battery case 80.

[0089] As shown in Figures 11, 12, and 17, the front frame 11 of the vehicle body frame 10 has a mounting flange 11T and a bottom frame 11U. The mounting flange 11T is provided along the upper left edge of the left frame 11L and the upper right edge of the right frame 11R, respectively. The bottom frame 11U extends between the lower edges of the left frame 11L and the right frame 11R. Multiple bottom frames 11U are arranged side by side at intervals in the front-rear direction at the lower part of the front frame 11.

[0090] The battery unit 8 is embedded in the space H1 inside the front frame 11, which is defined by the left frame 11L and the right frame 11R, and is connected and fixed to the mounting flange 11T and the bottom frame 11U.

[0091] As shown in Figure 17, in this embodiment, the battery unit 8 is fixed to the upper part of the front frame 11 such that the center of gravity of the battery unit 8 (for example, the center position between the left and right sides of the battery unit 8) coincides with the Z-axis centerline CL3 that passes through the center between the left and right sides of the vehicle frame 10 when viewed from the front and rear directions. As a result, the weight of the battery unit 8 is added to the center between the left and right sides of the vehicle frame 10, thus stabilizing the overall weight balance of the work vehicle 1.

[0092] <Modification> In the work vehicle 1 of the above embodiment, the electric motor 5 is configured to drive the travel device 3, the PTO shaft 2D, and the hydraulic pump 9 with two motors 5A and 5B. However, the electric motor 5 may be configured to drive the travel device 3, the PTO shaft 2D, and the hydraulic pump 9 individually with three motors 5A, 5B, and 5C.

[0093] For example, as a first modification, as shown in Figures 18 to 21, the electric motor 5 includes a third motor 5C in addition to the first motor 5A and the second motor 5B. In the following description of the first modification, the same configuration as the work vehicle 1 of the above embodiment will not be described.

[0094] The third motor 5C drives the hydraulic pump 9. The second motor 5B drives the PTO shaft 2D. That is, in this first modified example, the hydraulic pump 9 is driven by the power of the third motor 5C, and the PTO shaft 2D is driven by the power of the second motor 5B. The power transmission device 20 in this first modified example is configured to transmit the power of the second motor 5B to the PTO shaft 2D and the power of the third motor 5C to the hydraulic pump 9.

[0095] As described above, the third motor 5C is a pump that drives the hydraulic pump 9. On the other hand, the first motor 5A is a drive system motor responsible for the movement of the vehicle body 2, and the second motor 5B is a work system motor responsible for driving the work device U1. Therefore, the third motor 5C may be a motor with lower output than the first motor 5A and the second motor 5B.

[0096] As shown in Figure 19, the power transmission shaft 22 of the power transmission device 20 includes a first input shaft 31, a second input shaft 32, a rear wheel drive shaft 33, a PTO connecting shaft 34, a propeller shaft 35, and a front wheel drive shaft 36, in addition to a third input shaft 37.

[0097] In this first modified example, the second input shaft 32 connects the output shaft of the second motor 5B to the PTO connecting shaft 34. The PTO connecting shaft 34 connects the second input shaft 32 to the PTO shaft 2D. The third input shaft 37 connects the output shaft of the third motor 5C to the input shaft of the hydraulic pump 9.

[0098] The gear device 23 of this first modified example includes a fourth link gear 43E instead of the branch gear 43 of the above embodiment. The fourth link gear 43E transmits the rotation of the second input shaft 32 to the PTO connecting shaft 34. The second link gear 44 transmits the rotation of the PTO connecting shaft 34 to the PTO shaft 2D.

[0099] Thus, in this first modified example, the power transmission device 20 transmits the power of the second motor 5B only to the PTO shaft 2D, and transmits the power of the third motor 5C to the hydraulic pump 9. Therefore, in the case of the work vehicle 1 of this first modified example, the power transmission device 20 does not need to be equipped with an output switching clutch 47. In this case, the work vehicle 1 can switch the rotation and stopping of the PTO shaft 2D by controlling the operation of the second motor 5B.

[0100] As shown in Figures 20 and 21, the third motor 5C is installed at the front of the transmission case 12, alongside the first motor 5A and the second motor 5B. More specifically, the third motor 5C is positioned above and in the center between the left and right first motors 5A and the second motors 5B, which are arranged side by side at the front of the transmission case 12.

[0101] As shown in Figure 21, in this first modified example, the third motor 5C is located on the Z-axis centerline CL3, which passes through the center between the left and right sides of the vehicle body 2 when viewed from the front and rear directions. As a result, the weight of the third motor 5C is added to the center between the left and right sides of the vehicle body 2, making the overall weight balance of the work vehicle 1 more stable.

[0102] Furthermore, the placement of the third motor 5C is not limited to the upper center between the left and right-side-right positions of the first motor 5A and the second motor 5B. For example, as a second modification, as shown in Figure 22, the third motor 5C may be provided below the center between the left and right-side-right positions of the first motor 5A and the second motor 5B. Alternatively, as a third modification, as shown in Figure 23, the third motor 5C may be provided vertically aligned with the first motor 5A or the second motor 5B. That is, the third motor 5C may be provided at a position offset to the left or right of the Z-axis centerline CL3.

[0103] Furthermore, the third motor 5C may be arranged in a line from left to right together with the first motor 5A and the second motor 5B. For example, as a fourth modification, as shown in Figure 24, the third motor 5C is located in the center between the left and right sides of the first motor 5A and the second motor 5B.

[0104] In the work vehicle 1 of the above embodiment, the first motor 5A and the second motor 5B are arranged side by side, but the first motor 5A and the second motor 5B may also be arranged side by side vertically, or they may be arranged in a positional relationship that is offset in the front-rear direction of the vehicle body 2.

[0105] For example, in a fifth modified example, as shown in Figures 25 to 27, the first motor 5A and the second motor 5B are arranged vertically at the front of the transmission case 12. In the following description of the work vehicle 1 of the second modified example, the same configuration as the work vehicle 1 of the above embodiment will not be described.

[0106] As shown in Figure 27, the first motor 5A and the second motor 5B are arranged vertically on the Z-axis centerline CL3, which passes through the center between the left and right sides of the vehicle body 2 when viewed from the front and rear directions. As a result, the weights of both the first motor 5A and the second motor 5B are added to the center between the left and right sides of the vehicle body 2, thus stabilizing the overall weight balance of the work vehicle 1.

[0107] For example, as a sixth modification, as shown in Figure 28, the first motor 5A and the second motor 5B may be arranged in a positional relationship where they are offset from each other in the front-rear direction of the vehicle body 2. In the following description of the work vehicle 1 of the third modification, the same configuration as the work vehicle 1 of the above embodiment will not be described.

[0108] In this sixth modification, the first motor 5A and the second motor 5B are arranged vertically at the front of the transmission case 12, similar to the work vehicle 1 in the fifth modification described above. More specifically, the first motor 5A and the second motor 5B are arranged vertically on the Z-axis centerline CL3, which passes through the center between the left and right sides of the vehicle body 2. As a result, the weights of both the first motor 5A and the second motor 5B are added to the center between the left and right sides of the vehicle body 2, thus stabilizing the overall weight balance of the work vehicle 1.

[0109] The first motor 5A and the second motor 5B are positioned so that they are offset from each other in the front-to-back direction when viewed from the left-to-right direction. In this sixth modified example, the first motor 5A is located below and in front of the second motor 5B. In other words, the second motor 5B is located above and behind the first motor 5A.

[0110] Furthermore, the relative positions of the first motor 5A and the second motor 5B are not limited to the first motor 5A being in front of the second motor 5B. For example, the first motor 5A may be behind the second motor 5B. Also, if the first motor 5A and the second motor 5B are offset from each other in the front-rear direction as described above, the first motor 5A is not limited to being below the second motor 5B. For example, the first motor 5A may be above the second motor 5B.

[0111] The transmission case 12 of this sixth modification includes an extension case 12E in addition to the rear case 12A and mid case 12B. The extension case 12E is formed in a cylindrical shape that opens in the front-rear direction. The first motor 5A is connected to the front of the extension case 12E. The extension case 12E is connected to the front of the mid case 12B. The internal space of the extension case 12E is in communication with the internal space of the mid case 12B. The extension case 12E may be integrally formed with the mid case 12B.

[0112] The present invention provides a work vehicle 1 as described in the following items.

[0113] (Item 1) A work vehicle 1 comprising a vehicle body 2 that is drivable and can be fitted with a work device U1, a tank 6 for storing gas, a fuel cell 7 that generates electricity from the gas, and an electric motor 5 that is driven by the electricity generated by the fuel cell 7, wherein the electric motor 5 includes a first motor 5A that generates driving force for the vehicle body 2 and a second motor 5B that generates driving force for the work device U1.

[0114] According to the work vehicle 1 described in item 1, the vehicle body 2 and the work device U1 can be driven by independent electric motors 5. Therefore, the first motor 5A can be driven without being affected by the load applied to the second motor 5B when driving the work device U1. This enables highly stable driving.

[0115] Furthermore, in this design, the driving force of the vehicle body 2 and the work device U1 can be shared by two electric motors 5, making it possible to use small motors for each of these electric motors 5. This increases the degree of freedom in the arrangement of the electric motors 5 with other heavy components such as the tank 6 and fuel cell 7, making it easier to stabilize the overall weight balance of the vehicle. As a result, driving stability is further improved.

[0116] (Item 2) The work vehicle 1 according to Item 1, wherein the fuel cell 7 is provided at the rear of the vehicle body 2, and the first motor 5A and the second motor 5B are provided in the vehicle body 2 in front of and below the fuel cell 7.

[0117] In the work vehicle 1 related to item 2, the first motor 5A and the second motor 5B and the heavy fuel cell 7 are positioned on the vehicle body 2 in a front-to-rear position relative to each other, thus further stabilizing the overall weight balance of the vehicle. Moreover, in this design, since both the first motor 5A and the second motor 5B are located below and in front of the fuel cell 7, the center of gravity of the vehicle body 2 can be lowered, and the bias of the center of gravity in the front-to-rear direction of the vehicle body 2 can also be suppressed. Therefore, driving stability is further improved.

[0118] (Item 3) The work vehicle 1 according to Item 1 or Item 2, wherein the tank 6 is provided at the front of the vehicle body 2, and the first motor 5A and the second motor 5B are provided below the tank 6 on the vehicle body 2.

[0119] The gas storage tank 6 has a relatively large volume and tends to have a high center of gravity, which can cause the vehicle body 2 to sway while driving. However, with the work vehicle 1 described in item 3, the first motor 5A and the second motor 5B, which are positioned below the tank 6, can lower the center of gravity of the entire vehicle, thus further improving driving stability.

[0120] (Item 4) A work vehicle 1 according to any one of items 1 to 3, comprising a battery 8 that stores the electricity generated by the fuel cell 7 and supplies it to the electric motor 5, wherein the battery 8 is located at the front of the vehicle body 2, and the first motor 5A and the second motor 5B are located at the rear of the battery 8 in the vehicle body 2.

[0121] According to the work vehicle 1 described in item 4, the weight of the electric motor 5 and the weight of the battery 8 are distributed in the front-rear direction of the vehicle body 2, thus suppressing the bias of the vehicle's center of gravity in the front-rear direction. Therefore, driving stability is further improved.

[0122] (Item 5) The first motor 5A and the second motor 5B are arranged side by side in the left-right direction of the vehicle body 2 in the work vehicle 1 according to any one of Items 1 to 4.

[0123] According to the work vehicle 1 related to item 5, both the first motor 5A and the second motor 5B can be positioned at a low position on the vehicle body 2, thus lowering the overall center of gravity of the vehicle. This further improves driving stability.

[0124] (Item 6) The first motor 5A and the second motor 5B are arranged side by side in the vertical direction of the vehicle body 2 in the work vehicle 1 according to any one of items 1 to 4.

[0125] According to the work vehicle 1 related to item 6, even with a work vehicle 1 having a small tread, the vehicle body 2 and the work device U1 can be driven independently by the two electric motors 5 as described above, thus further improving driving stability.

[0126] (Item 7) The work vehicle 1 according to any one of Items 1 to 4, wherein the first motor and the second motor are arranged in a positional relationship that is offset in the front-rear direction of the vehicle body.

[0127] According to the work vehicle 1 related to item 7, the weights of the first motor 5A and the second motor 5B are distributed in the longitudinal direction of the vehicle body 2, so that the bias of the vehicle's center of gravity in the longitudinal direction can be suppressed. Therefore, driving stability is further improved.

[0128] (Item 8) A work vehicle 1 according to any one of items 1 to 4, comprising a hydraulic system 9, wherein the second motor 5B generates the driving force of the hydraulic system 9.

[0129] According to the work vehicle 1 related to item 8, there is no need to separately install an independent motor on the vehicle body 2 to drive the hydraulic system 9, thus the overall weight of the vehicle can be reduced. Therefore, driving stability is further improved.

[0130] (Item 9) A work vehicle 1 according to any one of items 1 to 4, comprising the hydraulic system 9, wherein the electric motor 5 includes a third motor 5C that generates the driving force of the hydraulic system 9.

[0131] According to the work vehicle 1 related to item 9, the work device U1 and the hydraulic system 9 can be driven by independent electric motors 5, thus increasing the flexibility of the arrangement of the hydraulic system 9 and other components. This makes it easier to stabilize the overall weight balance of the vehicle, further improving driving stability.

[0132] (Item 10) The work vehicle 1 according to Item 9, wherein the first motor 5A and the second motor 5B are provided side by side in the left-right direction of the vehicle body 2, and the third motor 5C is located in the center between the left and right sides of the first motor 5A and the second motor 5B.

[0133] In the work vehicle 1 related to item 10, both the first motor 5A and the second motor 5B can be positioned low on the vehicle body 2, thus lowering the overall center of gravity of the vehicle. Moreover, in this design, the third motor 5C is positioned between the first motor 5A and the second motor 5B, making it easier to stabilize the overall weight balance of the vehicle. Therefore, driving stability is further improved.

[0134] (Item 11) A work vehicle 1 according to any one of items 1 to 4, comprising a running device 3 that supports the vehicle body 2 so as to be able to move, and a power transmission device 20 that transmits the power of the first motor 5A to the running device 3, wherein the first motor 5A and the second motor 5B are connected to the casing 12 of the power transmission device 20.

[0135] According to the work vehicle 1 related to item 11, since both the first motor 5A and the second motor 5B are stably supported by the casing 12 of the power transmission device 20, the driving stability is further improved.

[0136] (Item 12) A work vehicle 1 according to any one of items 1 to 4, comprising a running device 3 that supports the vehicle body 2 so as to be able to move, wherein the running device 3 includes a front running device 3F provided at the front of the vehicle body 2 and a rear running device 3R provided at the rear of the vehicle body 2, and the first motor 5A and the second motor 5B are located in the center between the front and rear of the front running device 3F and the rear running device 3R.

[0137] In the work vehicle 1 relating to item 12, the weights of both the first motor 5A and the second motor 5B are added to the center between the front and rear of the front running gear 3F and the rear running gear 3R, thus suppressing the bias of the vehicle body 2's center of gravity in the front-rear direction. Therefore, driving stability is further improved.

[0138] (Item 13) A work vehicle 1 according to one aspect of the present invention is a work vehicle 1 according to any one of items 1 to 4, which is equipped with a control device 90 that controls the movement of the vehicle body 2 autonomously or by remote control.

[0139] According to the work vehicle 1 related to item 13, it is possible to realize a work vehicle 1 that enables highly stable autonomous driving or remotely controlled driving.

[0140] Having described the present invention above, the embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope of equivalents of the claims are intended to be included.

[0141] 1. Work vehicle 2. Body 3. Running gear 3F Front wheels (front running gear) 3R Rear wheels (rear running gear) 5. Electric motor 5A First motor 5B Second motor 5C Third motor 6. Hydrogen tank (tank) 7. Fuel cell unit (fuel cell) 8. Battery unit (battery) 9. Hydraulic pump (hydraulic system) 12. Transmission case (casing) 20. Power transmission device 90. Control device U1. Work device

Claims

1. A work vehicle comprising: a vehicle body that is drivable and can be fitted with work equipment; a tank for storing gas; a fuel cell for generating electricity from the gas; and an electric motor driven by the electricity generated by the fuel cell, wherein the electric motor includes a first motor for generating driving force for the vehicle body and a second motor for generating driving force for the work equipment.

2. The work vehicle according to claim 1, wherein the fuel cell is provided at the rear of the vehicle body, and the first motor and the second motor are provided in front of and below the fuel cell on the vehicle body.

3. The work vehicle according to claim 1, wherein the tank is provided at the front of the vehicle body, and the first motor and the second motor are provided below the tank on the vehicle body.

4. The work vehicle according to claim 1, comprising a battery that stores electricity generated by the fuel cell and supplies it to the electric motor, wherein the battery is located at the front of the vehicle body, and the first motor and the second motor are located behind the battery in the vehicle body.

5. The work vehicle according to any one of claims 1 to 4, wherein the first motor and the second motor are arranged side by side in the left-right direction of the vehicle body.

6. The work vehicle according to any one of claims 1 to 4, wherein the first motor and the second motor are arranged side by side in the vertical direction of the vehicle body.

7. The work vehicle according to any one of claims 1 to 4, wherein the first motor and the second motor are arranged in a positional relationship that is offset in the front-rear direction of the vehicle body.

8. A work vehicle according to any one of claims 1 to 4, comprising a hydraulic system, wherein the second motor generates the driving force for the hydraulic system.

9. A work vehicle according to any one of claims 1 to 4, comprising a hydraulic system, wherein the electric motor includes a third motor that generates the driving force for the hydraulic system.

10. The work vehicle according to claim 9, wherein the first motor and the second motor are provided side by side in the left-right direction of the vehicle body, and the third motor is located in the center between the left and right sides of the first motor and the second motor.

11. A work vehicle according to any one of claims 1 to 4, comprising: a running device that supports the vehicle body so as to be able to move; and a power transmission device that transmits power from the first motor to the running device, wherein the first motor and the second motor are connected to the casing of the power transmission device.

12. A work vehicle according to any one of claims 1 to 4, comprising a running device that supports the vehicle body so as to be able to move, wherein the running device includes a front running device provided at the front of the vehicle body and a rear running device provided at the rear of the vehicle body, and the first motor and the second motor are located centered between the front and rear of the front running device and the rear running device.

13. A work vehicle according to any one of claims 1 to 4, comprising a control device that controls the movement of the vehicle body autonomously or remotely.

Images