Work vehicle

Abstract

This work vehicle comprises a body, a fuel cell installed in the body, a tank for storing fuel to be supplied to the fuel cell, supply piping that is connected to the tank and that supplies fuel to the tank, and a frame on which the tank and the supply piping are mounted and which can be removed from the body.

Description

Work vehicles

[0001] This disclosure relates to a fuel cell-powered work vehicle. This application claims priority to Japanese Patent Application Nos. 2023-219236 and 2023-219165, filed December 26, 2023, and incorporates by reference all of the contents of those Japanese applications.

[0002] In order to protect the global environment, a work vehicle such as a tractor has been proposed that uses a fuel cell that generates electricity using hydrogen gas instead of an internal combustion engine that uses fossil fuels, and that the traveling device and work device are operated by an electric motor driven by the generated electricity (see Patent Document 1). This work vehicle is equipped with a tank that stores hydrogen gas. The tank is housed inside the ceiling of the cabin that surrounds the driver's seat. The tank is connected to pipes that flow hydrogen gas to the tank and pipes that flow hydrogen gas from the tank to the fuel cell.

[0003] JP 2023-13186 A

[0004] The work vehicle of the present disclosure comprises a vehicle body, a fuel cell mounted on the vehicle body, a tank for storing fuel to be supplied to the fuel cell, a supply pipe connected to the tank and for supplying fuel to the tank, and a frame to which the tank and the supply pipe are attached and which is removable from the vehicle body.

[0005]

[0033] FIG. 1 is a perspective view of a work vehicle according to an embodiment in Chapter 1. FIG. 2 is a front view of the work vehicle. FIG. 3 is a rear view of the work vehicle. FIG. 4 is a right side view of the work vehicle. FIG. 5 is a left side view of the work vehicle. FIG. 6 is a plan view of the work vehicle. FIG. 7 is a perspective view showing an example of the internal structure of a work vehicle. FIG. 8 is a perspective view showing the area around the fill port of the work vehicle. FIG. 9 is a block diagram showing an example of the functional configuration of a work vehicle. FIG. 10 is a left side view showing the tank and fill port removed. FIG. 11 is a left side view showing the tank and fill port removed and placed on a stand. FIG. 12 is a perspective view of a work vehicle according to an embodiment in Chapter 2. FIG. 13 is a right side view of a work vehicle with some exterior parts removed. FIG. 14 is a perspective view showing an example of the internal structure of a work vehicle. FIG. 15 is a left side view of a work vehicle with the rear wheels removed. FIG. 16 is a perspective view of the rear part of the body of a work vehicle with the rear wheels removed. FIG. 17 is an explanatory diagram showing an example of the mechanical characteristics of a support mechanism.

[0006] Preferred embodiments of the present disclosure will be described below in two parts: "Chapter 1" and "Chapter 2." In particular, the embodiment in Chapter 1 will be described with reference to FIGS. 1 to 11, and the embodiment in Chapter 2 will be described with reference to FIGS. 12 to 17.

[0007] <Chapter 1> [Problem to be Solved by the Present Disclosure] A tank that stores hydrogen gas may need to be removed for maintenance or replacement. However, because the tank is connected to auxiliary equipment such as piping, the removal process is complicated.

[0008] The present disclosure in Chapter 1 aims to provide a work vehicle that allows the tank to be easily removed.

[0009] [Advantages of the Present Disclosure] According to the present disclosure in Chapter 1, it is possible to provide a work vehicle that allows the tank to be easily removed.

[0010] [Outline of Embodiments of the Present Disclosure] Below, an outline of the embodiments of the present disclosure will be listed and explained in Chapter 1. (1) A work vehicle according to this embodiment includes a vehicle body, a fuel cell mounted on the vehicle body, a tank that stores fuel to be supplied to the fuel cell, a supply pipe connected to the tank and for supplying fuel to the tank, and a frame to which the tank and the supply pipe are attached and which is removable from the vehicle body.

[0011] According to the above configuration, the tank and the supply pipe can be removed from the vehicle body as a unit by removing the frame from the vehicle body, which makes it easy to remove the tank.

[0012] (2) The work vehicle described in (1) above is provided with a filler port that can be removed from the vehicle body together with the frame. With this configuration, the filler port can be removed from the vehicle body together with the tank.

[0013] (3) The work vehicle described in (1) or (2) above includes a valve connected to the supply pipe or the tank and removable from the vehicle body together with the frame. With this configuration, the valve can be removed from the vehicle body together with the tank.

[0014] (4) The work vehicle according to any one of (1) to (3) above includes a case that houses the tank and that is removable from the vehicle body together with the frame. With this configuration, the case that houses the tank can be removed from the vehicle body.

[0015] (5) The work vehicle according to any one of (1) to (4) above includes a driver's seat on the vehicle body, and the frame positions the tank above the driver's seat. This configuration makes it easy to remove the tank upward together with the frame.

[0016] [Details of the Embodiments of the Present Disclosure] Details of the embodiments of the present disclosure in Chapter 1 will now be described with reference to the drawings. Note that at least some of the embodiments in Chapter 1 described below may be combined in any manner. (Overall Structure of the Work Vehicle) FIG. 1 is a perspective view of a work vehicle according to the embodiment in Chapter 1. FIG. 2 is a front view of the work vehicle. FIG. 3 is a rear view of the work vehicle. FIG. 4 is a right side view of the work vehicle. FIG. 5 is a left side view of the work vehicle. FIG. 6 is a plan view of the work vehicle. Note that in this specification, the direction in which the work vehicle 1 moves forward is defined as "front," the direction in which the work vehicle 1 moves backward is defined as "rear," the left side of the work vehicle 1 when facing forward is defined as "left," and the right side of the work vehicle 1 when facing forward is defined as "right." In FIGS. 2 to 7, the forward, backward, left, right, up, and down directions are indicated by arrows X1, X2, Y1, Y2, Z1, and Z2, respectively.

[0017] 1 to 6, the work vehicle 1 is a vehicle used for agricultural work, specifically a tractor. However, the work vehicle 1 is not limited to a tractor, and may be a mobile body such as agricultural machinery, construction machinery, or a utility vehicle.

[0018] The work vehicle 1 includes a vehicle body 11, a traveling device 12 that supports the vehicle body 11, a driver's seat 15, and a cabin 16. The vehicle body 11 includes a chassis 41, a hood 34, a cover 111, the cabin 16, and a fender 47 for the rear wheel 12B. The hood 34 and the cover 111 are mounted on the chassis 41 of the vehicle body 11, in this order from the front to the rear, and the cabin 16 is disposed behind the cover 111. The hood 34, the cover 111, and the cabin 16 all function as covers that cover the equipment mounted on the vehicle body 11 (such as the fuel cell 24, radiators 48 and 49, and the seat 15A, which will be described later).

[0019] The work vehicle 1 further includes a tank unit 21 having multiple tanks 13 (see FIG. 4) for storing fuel, and a drive unit 14 that is powered by the stored fuel. The tank unit 21 includes a rectangular parallelepiped case 21A whose vertical length (height) is smaller than its longitudinal and transverse lengths, and the multiple tanks 13 are housed side by side within this case 21A. The tank unit 21 includes various valves 75-78 and sensors 81, 82 (see FIG. 9). The tank unit 21 is disposed above the driver's seat 15 and cabin 16 by a mounting frame 17.

[0020] The fuel is liquid or gas, and may be hydrogen, methane, carbon monoxide (CO), or the like. In this embodiment, the tank 13 stores hydrogen gas. Therefore, the work vehicle 1 is a fuel cell vehicle (FCV), and runs on electricity generated by a chemical reaction between hydrogen and oxygen in a fuel cell 24 as an energy source. The fuel cell 24 generates electricity using hydrogen. The fuel cell 24 may also generate electricity using methane or carbon monoxide (CO).

[0021] The drive device 14 includes a fuel cell 24, a battery unit 30, and an electric motor 31 (see FIG. 3; hereinafter, also referred to as the "motor 31"). The battery unit 30 incorporates at least one battery pack 30A (see FIG. 9) that stores the output power of the fuel cell 24.

[0022] As shown in FIG. 3 , the work vehicle 1 has a pipe 22 and a filling unit 25. In this embodiment, the pipe 22 allows hydrogen gas to pass through. However, the pipe 22 may also be a pipe allowing methane or carbon monoxide (CO) to pass through. The filling unit 25 has a filling port (receptacle; hereinafter simply referred to as the "filling port") 26 to which a filling nozzle 401 is connected. The filling port 26 is filled with hydrogen gas through the filling nozzle 401. However, the filling port 26 may also be filled with methane or carbon monoxide (CO) through the filling nozzle 401. In this embodiment, the filling port (gas filling port) 26 of the filling unit 25 is filled with hydrogen gas from a hydrogen gas supply machine (fuel supply machine) 400 (see FIG. 9 ) such as a gas station that is separate from the work vehicle 1. The hydrogen gas is supplied to the tank 13 through the pipe 22 (22A). The hydrogen gas in the tank 13 is supplied to the fuel cell 24 through the pipe 22 (22B). The specific configuration of the filling section 25 and the piping 22 will be described later.

[0023] The cabin 16 is a partitioned driver's compartment with front pillars, rear pillars, and a roof, and surrounds the driver's seat 15. The driver's seat 15 includes a seat 15A and a control device 15B. The control device 15B includes a steering wheel, levers, instruments, etc. The front pillars of the cabin 16 are located on the left and right sides in front of the driver's seat 15, and the rear pillars are located on the left and right sides behind the driver's seat 15. The cabin 16 includes a front panel 165 (see FIG. 2) between the left and right front pillars, a rear panel 161 (see FIG. 3) between the left and right rear pillars, and side panels 166 between the front and rear pillars. The side panels 166 include openable and closable doors. The front panel 165, rear panel 161, and side panels 166 are formed of transparent materials such as glass or synthetic resin, allowing the outside of the cabin 16 to be seen from inside and the inside from outside. The work vehicle 1 may include a canopy or roof hood instead of the cabin 16.

[0024] The traveling device 12 is composed of front wheels 12A and rear wheels 12B, both of which are arranged symmetrically on the left and right sides of the vehicle body 11. One or both of the front wheels 12A and the rear wheels 12B rotate by the power of a motor 31. One or both of the wheels 12A, 12B (drive wheels) that rotate by the power of the motor 31 may be crawlers (crawlers). The upper and front sides of the rear wheels 12B are covered by fenders 47.

[0025] 4 and 5, a first radiator 48, a fuel cell 24, and a second radiator 49 are mounted in this order from front to rear on a portion of the chassis 41 corresponding to the front wheels 12A. The first radiator 48 and the fuel cell 24 are covered by a hood (cover) 34, and the second radiator 49 is covered by a cover 111.

[0026] 4, the upper surface 111a of the cover 111 is higher than the top of the hood 34 but lower than the top of the steering wheel 15B of the driver's seat 15. The rear end of the hood 34 is located lower than the cover 111, and the upper surface 34a of the hood 34 is tapered from the rear end to the front end. This structure makes it difficult for the forward visibility of the operator sitting in the driver's seat 15 to be obstructed.

[0027] (Internal Structure of Work Vehicle) Figure 7 is a perspective view showing an example of the internal structure of a work vehicle. As shown in Figure 7, the chassis 41 that constitutes the vehicle body 11 is made of a steel frame that is long in the front-to-rear direction, and has a front frame 32 and a transmission case 33. The transmission case 33 is connected to the rear of the front frame 32, and the transmission case 33 and the front frame 32 form the framework of the vehicle body 11.

[0028] A mounting frame 17 for disposing the tank unit 21 above the cabin 16 is connected to the chassis 41. The mounting frame 17 includes a substantially rectangular ceiling frame 17A that is longer in the front-to-rear direction than in the left-to-right direction, a plurality of pillars 17B1, 17B2 that support the ceiling frame 17A from below, and a pair of left and right reinforcing frames 17C connected to the front end of the ceiling frame 17A. The mounting frame 17 also includes a base frame 17D to which the lower ends of the rear left and right pillars 17B2 are connected, and a pair of left and right lower frames 17E that extend downward from the base frame 17D. The base frame 17D is positioned approximately horizontally and extends in the left-to-right direction.

[0029] 1 , a tank unit 21 is placed on and connected to the ceiling frame 17A. The ceiling frame 17A is located higher than the roof of the cabin 16. Therefore, the tank unit 21 is disposed above the roof of the cabin 16.

[0030] The reinforcing frame 17C is a reinforcing diagonal member that slopes downward from the front end of the ceiling frame 17A to the front frame 32. Therefore, the rigidity of the mounting frame 17 in the front-to-rear direction is strengthened compared to when the ceiling frame 17A and the tank unit 21 are supported only by the pillars 17B1 and 17B2. The detailed structure of the mounting frame 17 will be described later.

[0031] 1 and 7 , a support frame 37 for supporting the battery unit 30 on the vehicle body 11 is connected to the chassis 41 of the work vehicle 1. Specifically, the motor 31 is mounted on the front frame 32 of the chassis 41, and the support frame 37 is attached to a portion of the front frame 32 corresponding to the motor 31. The support frame 37 is made of, for example, a metal frame member, and is attached in a cantilevered state so as to protrude to the right from the front frame 32.

[0032] The transmission case 33, located rearward of the motor 31, has a power transmission mechanism therein. The power transmission mechanism includes a transmission, a clutch, and a differential gear, and transmits the rotation of the output shaft of the motor 31 to the traveling device 12 while slowing or accelerating the rotation. The power transmission mechanism inside the transmission case 33 includes a branching mechanism that outputs a portion of the power of the motor 31 to a PTO shaft 334 (see FIGS. 3 and 9). The PTO shaft 334 is an output shaft that protrudes rearward from the transmission case 33.

[0033] A coupling device 44 (see FIG. 6), which is configured by, for example, a three-point linkage mechanism, is attached to the transmission case 33 to couple a work implement 335 (see FIG. 9, also called an "implement") for performing a desired agricultural task to the rear of the vehicle body 11. The work implement 335 is, for example, a cultivator or a baler.

[0034] For example, while the traveling device 12 is being driven, the rotational motion of the PTO shaft 334 is transmitted to the input shaft of the working device 335 connected to the coupling device 44. Therefore, the work vehicle 1 can drive the working device 335 with the power of the motor 31 while traveling in a field or the like.

[0035] FIG. 8 is a perspective view showing the area around the filling port of the work vehicle. The work vehicle 1 of this embodiment is equipped with a filling unit 25. The filling unit 25 is located on the rear surface of the work vehicle 1 (body 11). The filling unit 25 has a filling port 26 and a housing 28 that houses the filling port 26. The filling port 26 faces rearward, and a filling nozzle 401 of a hydrogen gas supply device 400 is inserted from the rear. The housing 28 has a case 28a and a lid 28b. The case 28a has walls on the top, bottom, left, right, and front, and is open at the rear. The lid 28b is openable and can close the opening of the case 28a. The piping 22 is connected to the filling unit 25 (filling port 26) from the front of the housing 28.

[0036] With this configuration, filling port 26 is protected by housing 28. Pipe 22A is connected to filling section 25 from the space formed between housing 28 and the rear of vehicle body 11. Connection section 29 between pipe 22A and housing 28 is not exposed to the wide space behind the vehicle, and connection section 29 is protected.

[0037] The filling section 25 is located behind the cabin 16 and between the rear wheels 12B on both the left and right sides. The filling section 25 is protected from the left and right sides by the rear wheels 12B and from the front by the cabin 16.

[0038] The filling sections 25 are disposed below the base frame 17D of the mounting frame 17. Each filling section 25 is supported on the base frame 17D via a bracket (mounting member) 27. The bracket is a plate-shaped member that extends downward from the base frame 17D. The filling sections 25 are protected from above by the base frame 17D. The filling sections 25 are disposed between the left and right lower frames 17E.

[0039] (Functional Configuration of Work Vehicle) Fig. 9 is a block diagram showing an example of the functional configuration of a work vehicle. As shown in Fig. 9, the functional systems of the work vehicle 1 include a fuel system FS, a power system PS, and a temperature control system TS.

[0040] Components of the fuel system FS include a tank unit 21. The tank unit 21 has at least one tank (hydrogen tank) 13, valves 75-78, and sensors 81, 82. Components of the temperature control system TS include a plurality of radiators 48, 49, and an air conditioner 50. Components of the power system PS include a fuel cell 24, a boost circuit 61, an inverter 62, a motor 31, a transmission case 33, DC / DC converters 64, 65, and a battery unit 30.

[0041] The work vehicle 1 of this embodiment is equipped with a plurality of tanks 13, for example, three tanks 13. Each tank 13 is connected to pipes 22A and 22B. Pipe (supply pipe) 22A is a gas pipe connecting a fill port 26 to each tank 13. Hydrogen gas is introduced into fill port 26 from a hydrogen gas supply device 400 at a gas station or the like. Pipe 22A guides the hydrogen gas introduced into fill port 26 to each tank 13.

[0042] A filling port 26 is connected to one end (upstream end) of the pipe 22A. The other end (downstream end) of the pipe 22A branches into multiple parts. The number of these branch sections 22A1 is the same as the number of tanks 13 (three in the illustrated example). The other end (downstream end) of each branch section 22A1 is connected to a tank 13. Therefore, hydrogen gas introduced from the filling port 26 flows through the pipe 22A, is branched at the branch sections 22A1, and then filled into each tank 13.

[0043] The branch portion 22A1 is provided with a check valve 75. The check valve 75 prevents hydrogen gas in the tank 13 from flowing back into the pipe 22A via the branch portion 22A1.

[0044] The pipe 22B is a gas pipe connecting the fuel cell 24 and the tank 13. The pipe 22B guides hydrogen gas stored in each tank 13 to the fuel cell 24. The pipe 22B has multiple branch portions 22B1 and a junction portion 22B2. The branch portion 22B1 is provided at one end (upstream end) of the pipe 22B. The number of branch portions 22B1 is the same as the number of tanks 13 (three in the illustrated example). One end (upstream end) of the branch portion 22B1 is connected to the tank 13. The other end (downstream end) of the branch portion 22B1 is connected to one end (upstream end) of the junction portion 22B2. The other end (downstream end) of the junction portion 22B2 is connected to the fuel cell 24. Therefore, hydrogen gas released from each tank 13 flows through the branch portion 22B1, is joined at the junction portion 22B2, and then is guided to the fuel cell 24.

[0045] An on-off valve 76 is provided at each branch 22B1 of the pipe 22B. Each on-off valve 76 switches between releasing and stopping (shutting off) the hydrogen gas release from each tank 13. The pipe 22B is provided with a pressure reducing valve 77 and a main on-off valve 78. The pressure reducing valve 77 reduces the pressure of the hydrogen gas released from the tank 13. The pressure of the hydrogen gas in the tank 13 is, for example, 35 megapascals or more, while the pressure of the hydrogen gas after being reduced by the pressure reducing valve 77 is, for example, about 2 atmospheres. The main on-off valve 78 switches between supplying the hydrogen gas reduced by the pressure reducing valve 77 to the fuel cell 24 and stopping (shutting off) the supply. The on-off valves 76, 78 are configured as electromagnetic valves operated by solenoids, electric valves operated by motors, or the like.

[0046] A pressure sensor 81 is provided between the multiple on-off valves 76 and the pressure reducing valve 77. The pressure sensor 81 detects the pressure of hydrogen gas released from the multiple tanks 13. The pressure detected by the pressure sensor 81 corresponds to the pressure of hydrogen gas inside the tanks 13 that are releasing hydrogen gas through the on-off valves 76. In addition, each tank 13 is provided with a temperature sensor 82. The temperature sensor 82 detects the temperature of the hydrogen gas inside the tank 13.

[0047] The pipe 22B (junction 22B2) is provided with a connector (joint) 22C. The pipe 22B has a portion on the tank unit 21 side and a portion on the fuel cell 24 side, and the two portions are connected by the connector 22C. In other words, the pipe 22B can be separated into the tank unit 21 side and the fuel cell 24 side via the connector 22C.

[0048] The hydrogen gas released from the tank 13 and flowing through the pipe 22B is supplied to the fuel cell 24. The fuel cell 24 is, for example, a battery module configured by stacking a plurality of unit cells each having a positive electrode and a negative electrode side by side. The fuel cell 24 aggregates the electric power generated by each unit cell to generate the electric power required to drive the electric motor 31.

[0049] The fuel cell 24 is connected to the second radiator 49 through a cooling flow path H2. The electrodes of the fuel cell 24 are adjusted to a predetermined temperature by the coolant circulated from the second radiator 49. This allows the fuel cell 24 to maintain high power generation efficiency.

[0050] The fuel cell 24 is electrically connected to the input side of a boost circuit 61, and the output side of the boost circuit 61 is electrically connected to the DC side of an inverter 62. The boost circuit 61 increases the voltage input from the fuel cell 24 and outputs it to the inverter 62 and the battery unit 30.

[0051] The inverter 62 is electrically connected to the motor 31. The inverter 62 converts the direct current input from the boost circuit 61 into three-phase alternating current and outputs it to the motor 31. Therefore, the power generated by the fuel cell 24 is boosted and converted into alternating current and transmitted to the motor 31.

[0052] The motor 31 has a rotor and a stator with multiple coils, and drives an output shaft at a predetermined torque and rotational speed. For example, the work vehicle 1 is equipped with only one motor 31, and the output shaft of the motor 31 is coupled to the transmission case 33. A plurality of motors 31 may be equipped. For example, if two types of motors 31 are provided, one for the front wheels 12A and one for the rear wheels 12B, the power of each motor 31 can be output to the front wheels 12A and the rear wheels 12B, respectively.

[0053] The power transmission mechanism of the transmission case 33 outputs all or part of the power of the motor 31 to the traveling device 12. When operating the working device 335, the power transmission mechanism also outputs the power of the motor 31 to the PTO shaft 334.

[0054] The battery unit 30 is a power storage device that absorbs load fluctuations of the fuel cell 24. Specifically, the battery unit 30 temporarily charges with power supplied from the boost circuit 61, and discharges it under high load to supply drive power for the motor 31 to the inverter 62. The battery unit 30 includes a battery pack 30A and a monitoring unit 30B. The battery pack 30A includes at least one cell. The cell is, for example, a charge-discharge type cell such as a lithium-ion battery cell. The output voltage of the battery unit 30 is, for example, 24 V.

[0055] The monitoring unit 30B includes a processor that controls switching of the operation (charging or discharging) of the battery pack 30A and measures the state of charge (for example, SOC).

[0056] The work vehicle 1 has a plurality of electrical components that operate at a lower voltage than the motor 31. These electrical components are supplied with DC power that has been stepped down by a step-down circuit. The plurality of electrical components includes, for example, an auxiliary battery 63, radiators 48, 49, and an air conditioning unit 50. The step-down circuit is, for example, a plurality of DC / DC converters 64, 65 (hereinafter also referred to as a "first converter 64" and a "second converter 65") that have different output voltages.

[0057] The first converter 64 steps down the DC voltage input from the boost circuit 61 to a first voltage (e.g., 12 volts) and supplies it to the auxiliary battery 63, the air conditioning device 50, etc. The second converter 65 steps down the DC voltage input from the boost circuit 61 to a second voltage (e.g., 24 volts) and supplies it to the radiators 48, 49. The inverter 62 and both converters 64, 65 are disposed in a portion of the chassis 41 corresponding to the driver's seat 15. The second voltage of the second converter 65 may be supplied to the battery unit 30.

[0058] As described above, the first radiator 48 is disposed in front of the fuel cell 24, and the second radiator 49 is disposed behind the fuel cell 24 (see FIG. 2). These radiators 48, 49 constitute a cooling system that uses a coolant (refrigerant) to cool electrical components such as the fuel cell 24, boost circuit 61, inverter 62, motor 31, and first and second converters 64, 65.

[0059] A cooling flow path H1, through which coolant is circulated by a pump 66, is connected to the first radiator 48, and the coolant is cooled by heat exchange with the external air. The first radiator 48 has a first fan 35 for promoting heat exchange with the external air. The cooling flow path H1 of the first radiator 48 cools electrical components (heat-generating components), such as the boost circuit 61, the inverter 62, the motor 31, and the first and second converters 64, 65.

[0060] A cooling flow path H2, through which coolant is circulated by a pump 67, is connected to the second radiator 49, and the coolant is cooled by heat exchange with the outside air. The second radiator 49 has a second fan 36 for promoting heat exchange with the outside air. The object to be cooled by the cooling flow path H2 of the second radiator 49 is, for example, an electrical component such as the fuel cell 24.

[0061] The auxiliary battery 63 is a power storage device that supplies power to the display, communication devices, and the like mounted in the driver's seat 15. The auxiliary battery 63 is, for example, a charge-discharge type lead-acid battery. The output voltage of the auxiliary battery (second battery) 63 is, for example, 12 V, which is lower than the output voltage (for example, 24 V) of the battery unit (first battery) 30. The auxiliary battery 63 can also be used as an auxiliary power source that supplies power to the control device 70 (described later) when the fuel cell 24 is stopped.

[0062] As shown in FIG. 9 , the work vehicle 1 further includes a control device 70. The control device 70 may be configured, for example, with an ECU (Electronic Control Unit) that communicates with various electrical components using a communication protocol such as CAN (Controller Area Network). For example, the control device 70 includes an ECU that controls the overall operation of the system, from power generation by the fuel cell 24 to power output, and an ECU that is involved in individual control of the tank unit 21, which includes the tank 13, valves 75-78, and sensors 81 and 82. Therefore, the control device 70 controls the opening and closing of the valves 76-78 included in the tank unit 21, acquires detection values ​​from the pressure sensor 81 and temperature sensor 82, and processes the acquired detection values.

[0063] (Specific Configuration of Mounting Frame 17) The mounting frame 17 (see FIG. 7) is a member for mounting the tank 13 that stores hydrogen gas on the vehicle body 11. The mounting frame 17 is fixed to the vehicle body 11. To this end, the vehicle body 11 has a first front support portion 51, a second front support portion 53, and a rear support portion 52 (see FIG. 3) as support portions for the mounting frame 17.

[0064] The first front support portions 51 (see FIG. 7 ) are located on both left-right sides in front of the vehicle body 11. The second front support portions 53 are located in front of the first front support portion 51 and on both left-right sides of the vehicle body 11. The first front support portion 51 and the second front support portion 53 are beam-shaped members that protrude on both left-right sides from the front frame 32. The first front support portion 51 is located behind the front wheel 12A, and the second front support portion 53 is located in front of the front wheel 12A. The first front support portion 51 and the second front support portion 53 are located below the upper end of the front wheel 12A.

[0065] The transmission case 33 of the vehicle body 11 has axle cases 33A for the rear wheels 12B on both the left and right sides of the rear portion. The rear support parts 52 (see FIG. 3) are formed by plate-shaped brackets fixed onto the left and right axle cases 33A.

[0066] As shown in FIG. 7, the mounting frame 17 includes a ceiling frame 17A, a pair of left and right front pillars 17B1, a pair of left and right rear pillars 17B2, a pair of left and right reinforcing frames 17C, a base frame 17D, and a pair of left and right lower frames 17E.

[0067] The ceiling frame 17A is a rectangular frame made up of four straight members on the front, back, left, and right sides. The ceiling frame 17A supports the tank 13. In this embodiment, a case 21A for the tank 13 is attached to the ceiling frame 17A, and the tank 13 is housed inside the case 21A.

[0068] The front pillars 17B1 are formed of straight members. The lower ends of the left and right front pillars 17B1 are connected to the first front support portions 51 on the respective left and right sides and extend upward from the first front support portions 51. The upper ends of the left and right front pillars 17B1 are connected to both left and right sides of the front portion of the ceiling frame 17A. The front pillars 17B1 support the front portion of the ceiling frame 17A from below on both left and right sides.

[0069] The front pillar 17B1 has a connecting plate (connecting member) 18a at its upper end, and the ceiling frame 17A has a connecting plate (connecting member) 18b on the underside of its front portion. Both connecting plates 18a, 18b are formed in a flat plate shape and are stacked on top of each other. Both connecting plates 18a, 18b are detachably connected by a connector 20 consisting of a bolt 20a that passes through them and a nut 20b that is fastened to the bolt 20a. However, both connecting plates 18a, 18b may also be detachably connected by known connecting means such as a connecting pin that passes through them or a locking metal fitting.

[0070] The pair of rear pillars 17B2 are formed of straight members. The lower ends of the rear pillars 17B2 are connected to the base frame 17D. The rear pillars 17B2 extend upward from the base frame 17D. The upper ends of the rear pillars 17B2 are connected to both left and right sides of the rear portion of the ceiling frame 17A. The rear pillars 17B2 support the rear portion of the ceiling frame 17A from below on both the left and right sides. The rear pillars 17B2 and the ceiling frame 17A are connected by fasteners such as bolts and nuts, or by welding.

[0071] As shown in Figure 8, the base frame 17D is a straight member extending in the left-right direction. The base frame 17D is supported from below by left and right lower frames 17E. The lower frames 17E are also straight members. The lower ends of the left and right lower frames 17E are connected to the rear support parts 52 on the same left and right sides and extend upward from the rear support parts 52.

[0072] The lower frame 17E has a connecting plate (connecting member) 18f at its upper end, and the base frame 17D has a connecting plate (connecting member) 18e on its lower surface. Both connecting plates 18f, 18e are formed in a flat plate shape and are stacked on top of each other. Both connecting plates 18f, 18e are detachably connected by a connector 20 consisting of a bolt 20a that passes through them and a nut 20b that is fastened to the bolt 20a. However, both connecting plates 18f, 18e may also be detachably connected by known connecting means such as a connecting pin that passes through them or a locking metal fitting.

[0073] 7, the reinforcing frame 17C extends obliquely from the front end of the ceiling frame 17A to the front end of the front frame 32 of the vehicle body 11. The front end (lower end) of the reinforcing frame 17C is connected to the second front support portion 53. The rear end (upper end) of the reinforcing frame 17C is connected to both left and right sides of the front part of the ceiling frame 17A.

[0074] The reinforcing frame 17C has a connecting plate (connecting member) 18d at its rear end, and the ceiling frame 17A also has a connecting plate (connecting member) 18c at its front end. Both connecting plates 18d, 18c are formed in flat plates and are stacked on top of each other. Both connecting plates 18d, 18c are detachably connected by a connector 20 consisting of a bolt 20a that passes through them and a nut 20b that is fastened to the bolt 20a. However, both connecting plates 18d, 18c may also be detachably connected by known connecting means such as a connecting pin that passes through them or a locking metal fitting.

[0075] The connecting plate 18d of the reinforcing frame 17C and the connecting plate 18a of the front pillar 17B1 may be connected to each other or may be integral. The rear end of the reinforcing frame 17C may be connected to the upper part of the front pillar 17B1 instead of the ceiling frame 17A. In this case, the rear end of the reinforcing frame 17C may be fixed to the upper part of the front pillar 17B1 by welding or the like, rather than being detachable therefrom.

[0076] The front pillar 17B1 and the reinforcing frame 17C are fixed to a front frame 32, which is part of the chassis 41, via a first front support portion 51 and a second front support portion 53. In contrast, the rear pillar 17B2, the base frame 17D, and the lower frame 17E are fixed to an axle case 33A of a transmission case 33, which is another part of the chassis 41, via rear support portions 52 (brackets).

[0077] The chassis 41 forms a framework for mounting the hood 34, drive unit 14, etc., and has a strong structure with high rigidity. The tank 13 is supported by the chassis 41 via the mounting frame 17, allowing the work vehicle 1 to travel stably.

[0078] As shown in Figure 7, the mounting frame 17 has a pair of inclined frames 17F. The inclined frames 17F are made of straight members. The inclined frames 17F extend obliquely rearward and upward from the front pillars 17B1 and are connected to the ceiling frame 17A. The inclined frames 17F increase the rigidity of the mounting frame 17 in the longitudinal direction of the vehicle.

[0079] The inclined frame 17F has a connecting plate 18g at its upper end, and the ceiling frame 17A has a connecting plate 18h on its underside. Both connecting plates 18g, 18h are formed in flat plates and are stacked on top of each other. Both connecting plates 18g, 18h are detachably connected by a connector consisting of a bolt passing through them and a nut fastened to the bolt. However, both connecting plates 18g, 18h may also be detachably connected by known connecting means such as a connecting pin passing through them or a locking metal fitting.

[0080] As shown in FIG. 1 , the ceiling frame 17A is located above the hood 34 and cover 111 of the vehicle body 11. The ceiling frame 17A is located above the driver's seat 15 and cabin 16 mounted on the vehicle body 11. The front end of the ceiling frame 17A is located forward of the driver's seat 15 (cabin 16). The front end of the ceiling frame 17A is located above the cover 111. The front end of the ceiling frame 17A is located behind the hood 34. The connecting portions (connecting plates 18a to 18d) between the ceiling frame 17A and the front pillars 17B1 and the reinforcing frame 17C are located above the hood 34, cover 111, driver's seat 15, and cabin 16, and in front of the driver's seat 15 and cabin 16. Furthermore, the connecting portions 18a to 18d are located above the cover 111 and behind the hood 34.

[0081] As shown in Figures 1 and 4, the base frame 17D is located behind the driver's seat 15 (cabin 16). The base frame 17D is located above the fender 47 and the rear wheel 12B. The base frame 17D is located behind the axle of the rear wheel 12B and in front of the rear end of the rear wheel 12B. The connecting portion (connecting plates 18e, 18f) between the base frame 17D and the lower frame 17E is located behind the driver's seat 15 (cabin 16) and above the fender 47 and the rear wheel 12B. The connecting portion (connecting plates 18e, 18f) between the base frame 17D and the lower frame 17E is located behind the axle of the rear wheel 12B and in front of the rear end of the rear wheel 12B.

[0082] 5 and 9, the piping 22 includes a piping 22B (hereinafter also referred to as the "front piping") that connects the tank 13 and the fuel cell 24, and a piping 22A (hereinafter also referred to as the "rear piping") that connects the tank 13 and the filling port 26. The front piping 22B is drawn out from the bottom surface on the front side of the case 21A in the tank unit 21 and connected to the fuel cell 24. The rear piping 22A is drawn out from the rear surface of the case 21A and connected to the filling port 26 (see FIG. 8).

[0083] As shown in Figures 1 and 5, the front piping 22B is arranged along one of the left and right (left) front pillars 17B1 and one of the left and right (left) inclined frames 17F of the mounting frame 17, and is attached to the front pillar 17B1 and the inclined frame 17F using attachment devices such as clamps or bands. As shown in Figures 1 and 4, the rear piping 22A is arranged along one of the (right) rear pillars 17B2 and is attached to the rear pillar 17B2 using attachment devices such as clamps or bands. Therefore, the ceiling frame 17A of the mounting frame 17 is used as a member for attaching the tank unit 21, the front pillars 17B1 and the inclined frame 17F of the mounting frame 17 are used as members for attaching the front piping 22B, and the rear pillar 17B2 of the mounting frame 17 is used as a member for attaching the rear piping 22A.

[0084] Each member constituting the mounting frame 17 is a hollow tubular member, and therefore, the piping 22 may be attached to the mounting frame 17 by passing all or part of it through the interior of the tubular member.

[0085] The base frame 17D of the mounting frame 17 is used as a member for mounting the filling section 25 (filling port 26). Therefore, the ceiling frame 17A, rear pillar 17B2, and base frame 17D of the mounting frame 17 constitute a mounting frame 19 for mounting the tank unit 21, rear piping 22A, and filling section 25.

[0086] As shown in Fig. 7, the connecting plates 18b, 18c, 18e, and 18h ​​of the mounting frame 19 (17A, 17B2, and 17D) can be attached to and detached from the connecting plates 18a, 18d, 18f, and 18g of the other members 17B1, 17C, and 17E of the mounting frame 17. Therefore, the mounting frame 19 can be removed from the vehicle body 11, as shown in Fig. 10. In addition, the tank unit 21, rear piping (supply piping) 22B, and filling port 26 mounted on the mounting frame 19 can also be removed from the vehicle body 11 together with the mounting frame 19.

[0087] The tank 13 of the tank unit 21 requires periodic inspection and maintenance, and may need to be replaced due to malfunction or deterioration over time. Therefore, the tank 13 may be removed from or attached to the vehicle body 11 of the work vehicle 1. However, the tank 13 is connected to ancillary equipment such as the piping 22 and valves 75-78. Therefore, when removing or attaching only the tank 13 from the vehicle body 11, these ancillary equipment must be detached from or attached to the tank 13, which makes the work extremely complicated. In particular, because high-pressure hydrogen gas flows from the fill port 26 through the rear piping 22A toward the tank 13, when the rear piping 22A that has been removed from the tank 13 is reattached to the tank 13, it is necessary to provide a sufficient seal to prevent leakage.

[0088] In this embodiment, the tank unit 21, rear piping 22A, and filling section 25 (filling port) 26 are mounted on the mounting frame 19, and these components can be removed from the vehicle body 11 together with the mounting frame 19. This makes the work easier than removing only the tank 13 from the vehicle body 11.

[0089] The front pipe 22B of the pipe 22 can be separated into the fuel cell 24 side and the tank unit 21 side by the connector 22C. Therefore, even if the mounting frame 19 is removed from the vehicle body 11, the front pipe 22B attached to the front pillar 17B1 and the oblique frame 17F can remain on the vehicle body 11. Furthermore, because hydrogen gas flows through the front pipe 22B after being depressurized by the pressure reducing valve 77, there is a lower possibility of hydrogen gas leakage compared to the rear pipe 22A. Therefore, there are few problems even if the front pipe 22B is configured to be detachable from the tank unit 21 via the connector 22C.

[0090] In the mounting frame 17, the attachment frame 19 and other members (front pillars 17B1, reinforcing frame 17C, inclined frame 17F, lower frame 17E) remaining on the vehicle body 11 side are connected in front of or behind the driver's seat 15 (cabin 16). In other words, the front part of the attachment frame 19 is connected to the vehicle body 11 side in front of the driver's seat 15 (cabin 16), and the rear part of the attachment frame 19 is connected to the vehicle body 11 side behind the driver's seat 15 (cabin 16).

[0091] In the mounting frame 17, the attachment frame 19 and other components remaining on the front side of the vehicle body 11 (front pillars 17B1, reinforcing frames 17C, and inclined frames 17F) are connected above the driver's seat 15 (cabin 16), and the attachment frame 19 and other components remaining on the rear side of the vehicle body 11 (lower frame 17E) are connected above the fender 47 and rear wheel 12B. In other words, the front part of the attachment frame 19 is connected to the vehicle body 11 above the driver's seat 15 (cabin 16), and the rear part of the attachment frame 19 is connected to the vehicle body 11 above the fender 47 and rear wheel 12B. As described above, the attachment frame 19 can be easily removed and attached without being obstructed by the driver's seat 15 (cabin 16), fender 47, rear wheel 12B, etc.

[0092] The mounting frame 19 can be lifted and removed from the vehicle body 11 using a moving device such as a crane. The mounting frame 19 may be provided with hanging hardware 102 (see FIG. 10 ), such as eye bolts or eye nuts, for connecting a moving device. Furthermore, the mounting frame 19 removed from the vehicle body 11 may be transferred to a platform 100 that supports the ceiling frame 17A and the base frame 17D from below, as shown in FIG. 11 . Using such a platform 100 makes it possible to support the mounting frame 19 while maintaining its posture, and to move the mounting frame 19 via wheels 101.

[0093] The mounting frame 19 is disposed above and behind the driver's seat 15 (cabin 16), and the tank 13 (tank unit 21), rear piping 22A, and filling port 26 (filling section 25) are disposed above or behind the driver's seat 15 (cabin 16). Therefore, the mounting frame 19 can be removed from the vehicle body 11 toward above or behind the driver's seat 15 (cabin 16), where a relatively large attachment and detachment space can be secured, and conversely, the mounting frame 19 can be attached to the vehicle body 11 from above or behind the driver's seat 15 (cabin 16).

[0094] (Other Modifications) The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present disclosure is not limited to the above-described embodiments, but includes all modifications within the scope of equivalents to the configurations described in the claims.

[0095] In the above embodiment, the tank unit 21, the rear piping 22A, and the filling section 25 are configured to be removable from the vehicle body 11 together with the mounting frame 19, but the front piping 22B may also be configured to be removable together with the mounting frame 19. In this case, the front pillars 17B1 and the inclined frames 17F of the mounting frame 17, to which the front piping 22B is attached, can also be configured to be removable from the vehicle body 11 (particularly the first front support section 51) together with the ceiling frame 17A, the rear pillars 17B2, and the base frame 17D. Alternatively, the entire mounting frame 17, including the reinforcing frames 17C and the lower frames 17E, can be configured to be removable from the vehicle body 11.

[0096] In another embodiment, the fuel cell 24 can be mounted on a frame that is integrally connected to the mounting frame 17, and the fuel cell 24 can be configured to be removable from the vehicle body 11 along with the tank 13, piping 22, and filling section 25.

[0097] The symbols used in this Chapter 1 are used only in this Chapter 1 and are not related to the symbols in other chapters.

[0098] [Explanation of symbols] 1: Work vehicle 11: Vehicle body 13: Tank 15: Driver's seat 19: Mounting frame 21A: Case 22A: Rear piping (supply piping) 24: Fuel cell 26: Filling port 75: Check valve 76: On-off valve 77: Pressure reducing valve 78: Main on-off valve

[0099] <Chapter 2> Next, a preferred embodiment of the present disclosure will be described in Chapter 2.

[0100] [Background Art] The aforementioned Patent Document 1 (JP 2023-13186 A) describes a work vehicle (e.g., an agricultural tractor) that has a tank for storing hydrogen gas, a fuel cell, and a motor. The fuel cell generates electricity from the hydrogen gas supplied from the tank, and the motor rotates using the electricity supplied from the fuel cell. Therefore, the work vehicle can travel by using the rotation of the motor as a driving force to rotate the drive wheels.

[0101] [Problem to be Solved by the Present Disclosure] The agricultural tractor exemplified in Patent Document 1 employs a mounting structure in which the tank is located above the interior space of the cabin. Therefore, Patent Document 1 does not consider, for example, how to support the mounting frame on the vehicle body in an appropriate manner in terms of manufacturing costs, when a mounting frame for mounting the tank on the exterior side of the cabin is employed.

[0102] In view of these conventional problems, the present disclosure in Chapter 2 aims to provide a work vehicle that can properly support a tank mounting frame on the vehicle body.

[0103] [Outline of Embodiments of the Present Disclosure] Below, an outline of the embodiments of the present disclosure will be listed and explained in Chapter 2. (1) A work vehicle according to this embodiment includes a vehicle body, a fuel cell attached to the vehicle body, a tank that supplies hydrogen to the fuel cell, a mounting frame that supports the tank, a cabin that forms a partitioned operator's compartment, and a support mechanism for supporting the cabin on the vehicle body, and the support mechanism further supports the mounting frame.

[0104] According to the work vehicle of this embodiment, the support mechanism for supporting the cabin on the vehicle body also supports the mounting frame, eliminating the need to provide a separate support mechanism for supporting only the mounting frame on the vehicle, thereby reducing the number of parts and manufacturing effort. Therefore, according to the work vehicle of this embodiment, the tank mounting frame can be supported on the vehicle body in a manner appropriate from the viewpoint of manufacturing costs.

[0105] (2) In the work vehicle described in (1) above, the mounting frame may support the tank above the cabin. This allows for a sufficient space to accommodate a tank of sufficient volume in a location that does not interfere with workers getting in and out of the vehicle.

[0106] (3) In the work vehicle of (1) or (2) described above, the support mechanism may include a support member having a first support portion that supports the cabin and a second support portion that supports the mounting frame at a position spaced apart from the first support portion, and a reinforcing member that strengthens the bending moment resistance of the second support portion.

[0107] In this case, since the first support portion and the second support portion are positioned apart, a sufficient area can be secured to support both the cabin and the mounting frame. Furthermore, since the reinforcing member strengthens the bending moment resistance of the second support portion, even if the area of ​​the support member is expanded by providing the second support portion, the support force of the support member for the mounting frame can be strengthened.

[0108] (4) In the work vehicle of (3) above, the vehicle body may have a wheel support (for example, a support cylinder protruding from a transmission case) that supports a wheel, and the first support part may be attached to the wheel support. In this way, the first support part is attached to the wheel support, which is a frame element of the vehicle body, and therefore the first support part can be firmly fixed to the vehicle body.

[0109] (5) In the work vehicle of (4) above, the reinforcing member may include a first reinforcing portion attached to the underside of the second support portion, a second reinforcing portion extending downward from the underside or side of the wheel support, and a connecting portion connecting the first reinforcing portion and the second reinforcing portion to each other. In this way, the bending moment generated in the second support portion can be offset by the first reinforcing portion and the second reinforcing portion, thereby effectively ensuring the supporting force of the second support portion.

[0110] (6) In the work vehicle of (4) above, the work vehicle may further include a coupling device for coupling a work implement, and the second reinforcement portion may be capable of attaching a tension member for pulling the coupling device. In this way, a component of the pulling force from the tension member is added to the reaction force of the first reinforcement portion, increasing the bending moment that offsets the bending moment of the second support portion. Therefore, the support force of the second support portion can be more effectively ensured.

[0111] [Details of Embodiments of the Present Disclosure] Hereinafter, with reference to the drawings, details of embodiments of the present disclosure will be described in Chapter 2. Note that at least some of the embodiments in Chapter 2 described below may be combined in any manner.

[0112] (Overall Structure of Work Vehicle) Figure 12 is a perspective view showing an example of the overall structure of the work vehicle 1 in Chapter 2. Figure 13 is a right side view of the work vehicle 1 with some of the exterior parts (such as the hood 34 and cover 51) removed. As shown in Figures 12 and 13, the work vehicle 1 is a vehicle used for agricultural work, specifically a tractor. However, the work vehicle 1 is not limited to a tractor, and may be a mobile body such as agricultural machinery, construction machinery, or a utility vehicle.

[0113] The work vehicle 1 includes a vehicle body 11, a running device 12 that supports the vehicle body 11, a driver's seat 15, and a cabin 16. The vehicle body 11 includes a chassis 41, a hood 34, a cover 51, the cabin 16, and fenders for the rear wheels 12B. Specifically, the hood 34 and the cover 51 are mounted on the chassis 41 of the vehicle body 11 in this order from the front to the rear, and the cabin 16 is disposed behind the cover 51.

[0114] The work vehicle 1 further includes a tank unit 21 having multiple tanks 13 (see FIG. 13 ) therein for storing fuel, and a drive unit 14 that is powered by the stored fuel. The fuel is liquid or gas, such as hydrogen, methane, or carbon monoxide (CO). In this embodiment, the tank 13 stores hydrogen gas. Therefore, the work vehicle 1 is a fuel cell vehicle (FCV), and runs on power generated by a chemical reaction between hydrogen and oxygen in a fuel cell 24. The fuel cell 24 generates power using hydrogen. The fuel cell 24 may also generate power using methane or carbon monoxide (CO).

[0115] The drive device 14 includes a fuel cell 24, a battery unit 30, and an electric motor 31 (see FIG. 14 ; hereinafter also referred to as the "motor 31"). The battery unit 30 incorporates at least one battery pack 30A (see FIG. 15 ) that stores the output power of the fuel cell 24. The work vehicle 1 has a hydrogen gas pipe 22. Hydrogen gas is supplied from a gas fill port (not shown) connected to the end of the pipe 22 and filled into each tank 13. The hydrogen gas in the tank 13 is supplied to the fuel cell 24 through the pipe 22.

[0116] The cabin 16 is a box structure that forms a partitioned driver's cab and has front pillars, rear pillars, and a roof. The front pillars are located on the left and right sides in front of the driver's seat 15, and the rear pillars are located on the left and right sides behind the driver's seat 15. The work vehicle 1 may have a canopy or ropes instead of the cabin 16. When the work vehicle 1 is not equipped with the cabin 16, the tank unit 21 is disposed above the driver's seat 15 by a mounting frame 17, which will be described later.

[0117] The traveling device 12 is composed of front wheels 12A and rear wheels 12B, both of which are arranged symmetrically on the left and right sides of the vehicle body 11. One or both of the front wheels 12A and the rear wheels 12B rotate by the power of a motor 31. One or both of the wheels 12A, 12B (drive wheels) that rotate by the power of the motor 31 may be crawlers (crawlers).

[0118] 13, a first radiator 48, a fuel cell 24, and a second radiator 49 are mounted in this order from front to rear on a portion of the chassis 41 corresponding to the front wheels 12A. The first radiator 48 and the fuel cell 24 are covered by the hood 34, and the second radiator 49 is covered by a cover 51.

[0119] 12, the top surface of the cover 51 is higher than the top edge of the hood 34 but lower than the top edge of the steering wheel of the driver's seat 15. The rear end of the hood 34 is located lower than the cover 51, and the top surface of the hood 34 is tapered from the rear end to the front end. This structure makes it difficult for the forward visibility of the operator sitting in the driver's seat 15 to be obstructed.

[0120] (Internal Structure of Work Vehicle) Figure 14 is a perspective view showing an example of the internal structure of the work vehicle 1. As shown in Figure 14, the chassis 41 that constitutes the vehicle body 11 is made of a steel frame that is long in the front-to-rear direction, and has a front frame 32 and a transmission case 33. The transmission case 33 is connected to the rear of the front frame 32, and the framework of the vehicle body 11 is formed by the transmission case 33 and the front frame 32.

[0121] A mounting frame 17 for disposing the tank unit 21 above the cabin 16 is connected to the chassis 41 of the vehicle body 11. The mounting frame 17 includes a substantially rectangular ceiling frame 17A that is long in the front-to-rear direction, a rear frame 17B that supports the rear end of the ceiling frame 17A, a front pillar 17C that supports the front end of the ceiling frame 17A, and a rear pillar 17D that supports the rear frame 17B. The tank unit 21 is connected to the ceiling frame 17A in a horizontally placed state.

[0122] As shown in Figure 13, the ceiling frame 17A is located higher than the roof of the cabin 16. Therefore, the tank unit 21 is disposed above the roof of the cabin 16. The mounting frame 17 further has a reinforcing frame 17E. The reinforcing frame 17E is a reinforcing diagonal member that slopes downward toward the front. The upper end of the reinforcing frame 17E is connected to the front end of the ceiling frame 17A, and the lower end of the reinforcing frame 17E is connected to the front end of the chassis 41. A more detailed support structure for the mounting frame 17 will be described later.

[0123] A support frame 37 for supporting the battery unit 30 is connected to the chassis 41 of the vehicle body 11. Specifically, the motor 31 is mounted on the front frame 32 of the chassis 41, and the support frame 37 is attached to a portion of the front frame 32 corresponding to the motor 31. The support frame 37 is made of, for example, a metal frame member, and is attached in a cantilevered state so as to protrude to the right from the front frame 32.

[0124] The transmission case 33, located rearward of the motor 31, has a power transmission mechanism therein. The power transmission mechanism includes a transmission, a clutch, and a differential gear, and transmits the rotation of the output shaft of the motor 31 to the traveling device 12 while slowing or accelerating the rotation. The power transmission mechanism inside the transmission case 33 includes a branching mechanism that outputs a portion of the power of the motor 31 to a PTO shaft 52 (see FIG. 15). The PTO shaft 52 is an output shaft that protrudes rearward from the transmission case 33.

[0125] A coupling device 44 (see FIG. 15 ), for example, configured by a three-point linkage mechanism, is attached to the transmission case 33 for coupling a work implement (also referred to as an "implement") for performing a desired agricultural task to the rear of the vehicle body 11. The coupling device 44, which is configured by a three-point linkage mechanism, may be configured, for example, by an upper arm 44A that protrudes rearward from the transmission case 33 and a pair of lower arms 44B on the left and right. The work implement may be, for example, a cultivator or a baler.

[0126] For example, while the traveling device 12 is being driven, the rotational motion of the PTO shaft 52 is transmitted to the input shaft of the work device connected to the coupling device 44. Therefore, the work vehicle 1 can drive the work device with the power of the motor 31 while traveling in a field or the like.

[0127] (Support structure of the mounting frame) Figure 15 is a left side view of the work vehicle 1 with the rear wheel 12B removed. As shown in Figure 15, the mounting frame 17 that supports the tank unit 21 is connected to the chassis 41 at the following three types of connecting positions in the front-to-rear direction, and each connecting position is symmetrical on the left and right. Therefore, the mounting frame 17 is supported by the chassis 41 of the vehicle body 11 at a total of six points.

[0128] First position P1: A position where the reinforcing frame 17E of the mounting frame 17 is connected to the front end of the chassis 41 (for example, the front part of the front frame 32). Second position P2: A position where the front pillar 17C of the mounting frame 17 is connected to the middle part of the chassis 41 (for example, the rear part of the front frame 32). Third position P3: A position where the rear pillar 17D of the mounting frame 17 is connected to the rear end of the chassis 41 (for example, the wheel support 101 of the transmission case 33).

[0129] Specifically, a front bracket 53 protrudes from the front frame 32 at a first position P1, and a lower end flange of the reinforcing frame 17E is fastened with bolts to the front bracket 53. An intermediate bracket 54 protrudes from the front frame 32 at a second position P2, and a lower end flange of the front pillar 17C is fastened with bolts to the intermediate bracket 54.

[0130] Meanwhile, a support mechanism 100 for supporting the cabin 16 on the chassis 41 of the vehicle body 11 is configured in the transmission case 33. The support mechanism 100 is structured to support both the cabin 16 and the mounting frame 17, and the lower end flanges of the rear pillars 17D of the mounting frame 17 are fastened with bolts to components of the support mechanism 100. A specific example of the support mechanism 100 will be described below with reference to FIG. 16 .

[0131] (Specific Example of Support Mechanism) Figure 16 is a perspective view of the rear body of the work vehicle 1 with the rear wheel 12B removed. As shown in Figure 16, the support mechanism 100 includes a wheel support 101, which is a component of the chassis 41, and a support member 102 attached to the wheel support 101. The wheel support 101 is, for example, a support cylinder formed integrally with the transmission case 33. The drive shaft of the rear wheel 12B is rotatably housed inside the support cylinder.

[0132] The support member 102 is, for example, a steel mounting bracket that is longer in the front-to-rear direction than the wheel support 101, and the cabin 16 and the mounting frame 17 are both supported on the chassis 41 via the support member 102. That is, the support member 102 has a first support portion 103 that is a portion that supports the cabin 16, and a second support portion 104 that is a portion that supports the mounting frame 17.

[0133] Of the two support portions 103, 104, the first support portion 103 is attached to the wheel support body 101 by bolting or the like. A support bracket 105 having a U-shaped cross section is fixed to the upper surface of the first support portion 103 by welding or the like, and a mounting stay 106 protruding from the lower back surface of the cabin 16 is bolted to the upper surface of the support bracket 105. In this way, the cabin 16 is supported on the wheel support body 101 via the mounting stay 106, the support bracket 105, and the first support portion 103.

[0134] Of the two support portions 103, 104, the second support portion 104 is formed of a plate member that protrudes rearward in a cantilevered manner from the first support portion 103. A rear pillar 17D of the mounting frame 17 is fixed to the upper surface of the second support portion 104. This fixing is performed, for example, by fastening the lower end flange of the rear pillar 17D to the second support portion 104 with a bolt.

[0135] As described above, the second support portion 104 is made of a plate member that protrudes rearward in a cantilevered manner from the first support portion 103. Therefore, a downward bending moment based on the axial force of the rear pillar 17D is constantly generated at the base of the second support portion 104. Therefore, there is a concern that the second support portion 104 may bend downward due to vertical vibrations during field work or may break due to deterioration over time. Therefore, the support mechanism 100 has a reinforcing member 107 that strengthens the bending moment resistance of the second support portion 104.

[0136] 16 , the reinforcing member 107 is a member that also functions to connect the second support portion 104 to the wheel support 101. Specifically, the reinforcing member 107 includes a first reinforcing portion 108 attached to the lower surface of the second support portion 104, a second reinforcing portion 109 extending downward from the lower surface of the wheel support 101, and a connecting portion 110 that connects the first reinforcing portion 108 and the second reinforcing portion 109 to each other. Note that the second reinforcing portion 109 may be a member that extends downward from the side surface of the wheel support 101.

[0137] The first reinforcing portion 108 is made of a steel plate that protrudes downward from the lower surface of the second support portion 104 at a forward incline. The protruding direction of the first reinforcing portion 108 is, for example, a direction that is substantially parallel to the rear pillar 17D. The second reinforcing portion 109 is made of a steel plate that protrudes downward from the lower surface or side surface of the wheel support body 101 at a rearward incline. The inclination of the second reinforcing portion 109 is set to an extent that an overlapping portion with the tip of the first reinforcing portion 108 can be created.

[0138] The connecting portion 110 is a member that connects the overlapping portions of the first reinforcing portion 108 and the second reinforcing portion 109, and is composed of, for example, a bolt and nut that passes through the overlapping portion and fastens the bolt. However, the connecting portion 110 is not limited to the bolt and nut described above, and may be a portion that connects the overlapping portions using other fastening methods such as arc welding or welding. Furthermore, the first reinforcing portion 108 and the second reinforcing portion 109 may be composed of a single steel plate material formed into a substantially V-shape. In this case, the bent portion of the V-shaped steel member corresponds to the connecting portion 110.

[0139] The connecting device (three-point link mechanism) 44 further includes a length-adjustable tension member 44C that applies tension to the lower arm 44B. The tension member 44C is, for example, a turnbuckle. The front end of the tension member 44C is connected to the rear end of the second reinforcing part 109, and the rear end of the tension member 44C is connected to the middle part of the lower arm 44B. Therefore, the second reinforcing part 109 also functions as an attachment part for the tension member 44C of the connecting device 44.

[0140] (Dynamic Characteristics of Support Mechanism) Fig. 17 is an explanatory diagram showing an example of the dynamic characteristics of the support mechanism 100. The meanings of the parameters shown in Fig. 17 are as follows: N: Axial force applied from the rear pillar 17D to the second support portion 104 R: Reaction force applied from the first reinforcing portion 108 to the second support portion 104 F: Traction force acting from the tension member 44C to the second reinforcing portion 109

[0141] Mn: bending moment (downward) generated in the second support portion 104 due to the axial force N Mr: bending moment (upward) generated in the second support portion 104 due to the reaction force R As shown in Figure 17, when the second support portion 104 is a cantilever member that protrudes rearward, a downward bending moment Mn caused by the axial force N is generated in the second support portion 104, but this bending moment Mn is offset by an upward bending moment Mr caused by the reaction force R.

[0142] Therefore, even though the second support portion 104 that supports the rear pillar 17D is configured as a cantilever member, it is possible to effectively ensure the support force of the second support portion 104. Furthermore, when the second support portion 104 receives a tractive force F from the tension member 44C, a component force of the tractive force F is added to the reaction force R, and the upward bending moment Mr that offsets the bending moment Mn increases. Therefore, it is possible to more effectively ensure the support force of the second support portion 104.

[0143] (Other Modifications) The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present disclosure is not limited to the above-described embodiments, and includes all modifications within the scope equivalent to the configurations described in the claims. For example, while the above-described embodiments illustrate the case where the tank unit 21 is mounted on the mounting frame 17, the mounting frame 17 may also be configured to mount at least one tank (hydrogen tank) 13 that is not unitized.

[0144] [Explanation of symbols] 1 Work vehicle 11 Vehicle body 12 Traveling device 12A Front wheels 12B Rear wheels 13 Tank (hydrogen tank) 14 Drive device 15 Driver's seat 16 Cabin 17 Mounting frame 17A Ceiling frame 17B Rear frame 17C Front pillar 17D Rear pillar 17E Reinforcement frame 21 Tank unit 22 Piping 24 Fuel cell 30 Battery unit 30A Battery pack 31 Motor (electric motor) 32 Front frame 33 Transmission case 34 Bonnet 37 Support frame 41 Chassis 44 Coupling device 44A Upper arm 44B Lower arm 44C Tension member 48 First radiator 49 Second radiator 51 Cover 53 Front bracket 54 Intermediate bracket 100 Support mechanism 101 Wheel support 102 Support member 103 First support portion 104 Second support portion 105 Support metal fitting 106 Mounting stay 107 Reinforcing member 108 First reinforcing portion 109 Second reinforcing portion 110 Connecting portion

Claims

1. A work vehicle comprising a vehicle body, a fuel cell mounted on the vehicle body, a tank for storing fuel to be supplied to the fuel cell, a supply pipe connected to the tank and for supplying fuel to the tank, and a frame to which the tank and the supply pipe are attached and which is removable from the vehicle body.

2. The work vehicle according to claim 1, comprising a filling port removable from the vehicle body together with the frame.

3. The work vehicle according to claim 1 or 2, comprising a valve connected to the supply pipe or the tank and removable from the vehicle body together with the frame.

4. The work vehicle according to any one of claims 1 to 3, comprising a case in which the tank is accommodated and which is removable from the vehicle body together with the frame.

5. The work vehicle according to any one of claims 1 to 4, comprising a driver's seat on the vehicle body, and the frame disposing the tank above the driver's seat.

Images