Work machine and work vehicle

Abstract

A work machine comprises: a vehicle body 11; a fuel cell 24; a battery 30; a motor 31; a first power converter (converter 26); and a second power converter (inverter 27). The vehicle body 11 has a vehicle body frame 41 and a support structure 50 for attaching the first power converter and the second power converter to the vehicle body frame 41. The support structure 50 has: a base 53 attached to the vehicle body frame 41; a first support 51 which has a first erected part erected from the base 53 and in which the first power converter is attached to and supported by the first erected part; and a second support 52 which has a second erected part erected from the base 53 and in which the second power converter is attached to and supported by the second erected part.

Description

Work machines and work vehicles

[0001] The present invention relates to a work machine and a work vehicle. This application claims priority to Japanese Application No. 2023-219142, filed December 26, 2023, and incorporates the entire contents of said Japanese application by reference. This application claims priority to Japanese Application No. 2023-219206, filed December 26, 2023, and incorporates the entire contents of said Japanese application by reference. This application claims priority to Japanese Application No. 2023-219315, filed December 26, 2023, and incorporates the entire contents of said Japanese application by reference.

[0002] From the viewpoint of environmental protection, a work machine has been proposed that is equipped with a fuel cell and driven by a motor that rotates using the power generated by the fuel cell (see, for example, Patent Document 1). The work machine disclosed in Patent Document 1 is a tractor. Hydrogen is used as fuel for the fuel cell. The tractor has electrical components such as a battery that stores the power generated by the fuel cell. Patent Document 2 discloses a work vehicle that includes a motor, a battery, and a fuel cell arranged under the hood. The fuel cell uses hydrogen gas to generate power that is stored in the battery. The motor rotates using the power from the battery. The work vehicle travels using the rotational force of the motor as driving force.

[0003] JP 2023-13186 A JP 2023-013188 A

[0004] A work machine according to one embodiment of the present invention has a vehicle body, a fuel cell mounted on the vehicle body, a battery that stores power generated by the fuel cell, a motor that operates using the power as energy, a first power converter, and a second power converter, and the vehicle body has a body frame and a support structure for attaching the first power converter and the second power converter to the body frame, and the support structure has a base portion attached to the body frame, a first support portion which has a first upright portion that stands up from the base portion and to which the first power converter is attached and supported by the first upright portion, and a second support portion which has a second upright portion that stands up from the base portion and to which the second power converter is attached and supported by the second upright portion.

[0005] A work vehicle according to one embodiment of the present invention comprises a body having a motor, a working device operated by power from the motor, a support body supporting a transmission shaft that transmits power from the motor to the working device, and a pair of vertical frames connected to the front side of the support body and arranged spaced apart from each other in the vehicle width direction, electrical equipment including a battery unit that stores power supplied to the motor, a fuel cell provided above the pair of vertical frames and generating power to be stored in the battery unit, auxiliary equipment associated with the fuel cell, and a hood that covers the fuel cell, and at least one of the electrical equipment and the auxiliary equipment is arranged between the pair of vertical frames.

[0006] A work machine according to one embodiment of the present invention has a machine frame, a fuel cell mounted on the machine frame, electrical equipment mounted on the machine frame, and an auxiliary heat exchanger that performs heat exchange between a first heat medium that adjusts the temperature of the fuel cell and a second heat medium that adjusts the temperature of the electrical equipment.

[0007] FIG. 1 is a perspective view showing an example of the overall structure of a work machine in Chapter 1. FIG. 2 is a left side view of the work machine in Chapter 1. FIG. 3 is a bottom view of the work machine in Chapter 1. FIG. 4 is a right side view of the work machine in Chapter 1 with some of the exterior parts removed. FIG. 5 is a perspective view showing an example of the internal structure of a work vehicle in Chapter 1. FIG. 6 is a block diagram showing an example of the functional configuration of a work vehicle in Chapter 1. FIG. 7 is a perspective view of the support structure in Chapter 1 as seen from the outside in the vehicle width direction. FIG. 8 is an exploded view of the support structure in Chapter 1. FIG. 9 is a perspective view of the support structure in Chapter 1 as seen from the inside in the vehicle width direction. FIG. 10 is a perspective view of the support structure in Chapter 1 with the cover removed. FIG. 11 is a perspective view of the support structure in Chapter 1 with the second support section and inverter removed. FIG. 12 is a perspective view showing a first modified example of the support structure in Chapter 1. FIG. 13 is a perspective view showing the support structure in FIG. 12 in an exploded state. FIG. 14 is a perspective view of a second modified example of the support structure in Chapter 1.

[0043] Figure 15 is a perspective view of the support structure of Figure 14 when viewed from a different angle. Figure 16 is a perspective view showing one embodiment of the work vehicle disclosed in Chapter 2. Figure 17 is a front view of the work vehicle shown in Figure 16. Figure 18 is a rear view of the work vehicle shown in Figure 16. Figure 19 is a side view (right side view) of the work vehicle shown in Figure 16. Figure 20 is a side view (left side view) of the work vehicle shown in Figure 16. Figure 21 is a plan view of the work vehicle shown in Figure 16. Figure 22 is a perspective view showing a portion of the work vehicle shown in Figure 16 in an exploded form. Figure 23 is a right side view of the work vehicle shown in Figure 16, with the hood, cover, and part of the tank case removed. Figure 24 is a schematic bottom view of the front part of the work vehicle shown in Figure 16, viewed from below. Figure 25 is a perspective view showing an example of the overall structure of a work machine in Chapter 3. Figure 26 is a right side view of the work vehicle in Chapter 3 with some of the exterior parts removed. Fig. 27 is a perspective view showing an example of the internal structure of a work vehicle in Chapter 3. Fig. 28 is a block diagram showing an example of the functional configuration of a work vehicle in Chapter 3. Fig. 29 is an explanatory diagram showing an example of a temperature control system in Chapter 3. Fig. 30 is an explanatory diagram showing a modified example of the temperature control system in Chapter 3. Fig. 31 is an explanatory diagram of a temperature control system of a work vehicle different from the configuration shown in Figs. 29 and 30.

[0008] <Chapter 1> <Problem to be Solved by the Present Disclosure> In the case of a work machine such as that described above, it is necessary to transform the power obtained by the fuel cell and convert it from direct current to alternating current. To achieve this, the work machine has a power converter. Therefore, an object of the present disclosure is to provide a work machine that has new technical means for mounting a power converter.

[0009] Effect of the Present Disclosure According to the work machine of the present disclosure, the first upright portion supporting the first power converter and the second upright portion supporting the second power converter are in an upright state from a base portion attached to the body frame, making the support structure smaller in the horizontal direction.

[0010] <Outline of Embodiments of the Present Disclosure> An outline of an embodiment of the present disclosure will be described below. (1) A work machine according to an embodiment of the present disclosure includes a vehicle body, a fuel cell mounted on the vehicle body, a battery that stores electric power generated by the fuel cell, a motor that operates using the electric power as energy, a first electric power converter, and a second electric power converter, wherein the vehicle body includes a body frame and a support structure for attaching the first electric power converter and the second electric power converter to the body frame, and the support structure includes a base portion attached to the body frame, a first support portion having a first upright portion that stands up from the base portion and to which the first electric power converter is attached and supported by the first upright portion, and a second support portion having a second upright portion that stands up from the base portion and to which the second electric power converter is attached and supported by the second upright portion.

[0011] In a work machine having the above configuration, the first upright portion supporting the first power converter and the second upright portion supporting the second power converter are in an upright state from a base portion attached to the body frame, and the support structure is small in the horizontal direction (vehicle width direction).

[0012] (2) Preferably, in the work machine of (1), the first power converter is formed in a box shape, and the first upright portion has a first mounting surface that faces one side of the box-shaped first power converter and to which the one side is attached. According to the above configuration, the first power converter and the first upright portion that supports it are installed so as to rise from the base portion.

[0013] (3) Preferably, in the work machine of (2), the second power converter is formed in a box shape, and the second upright portion has a second mounting surface that faces one side of the box-shaped second power converter and to which the one side is attached. According to the above configuration, the second power converter and the second upright portion that supports it are installed so as to rise from the base portion.

[0014] (4) Preferably, in the work machine of (3), the first mounting surface and the second mounting surface are spaced apart in the width direction of the vehicle body. (5) Preferably, in the work machine of (4), the first power converter is disposed between the first mounting surface and the second mounting surface.

[0015] (6) Preferably, in the work machine of any one of (1) to (5), the first support portion and the second support portion are each formed of separate members and can be attached to the base portion individually. With this configuration, the first power converter and the second power converter can be attached and detached individually, which further improves assembly workability and maintainability.

[0016] (7) Preferably, in the working machine of any one of (1) to (5), the first support portion, the second support portion, and a portion of the base portion are configured as a single member. According to this configuration, the first support portion, the second support portion, and a portion of the base portion are integrated, and can be attached to or detached from the vehicle body as a single unit.

[0017] (8) Preferably, in the work machine of any one of (1) to (7), the support structure has a cover that covers a support unit including the first support portion and the second support portion from the side of the vehicle. According to this configuration, even if a foreign object is scattered onto the support unit from outside the vehicle body, the support unit that supports the first power converter and the second power converter is protected from the foreign object by the cover.

[0018] (9) Preferably, in the work machine of (8), the first support portion and the second support portion are arranged side by side in the vehicle width direction, and the cover covers the support unit from the outside in the vehicle width direction. With this configuration, maintenance of one or both of the first power converter and the second power converter can be performed by removing the cover.

[0019] (10) Preferably, in the work machine of (8) or (9), the first power converter and the second power converter are each connected to a harness, and the cover covers a connection portion between the first power converter and the harness and a connection portion between the second power converter and the harness. According to this configuration, the connection portions of the harness are covered by the cover and protected from foreign matter.

[0020] (11) Preferably, in the work machine of any one of (1) to (10), the vehicle body has a cabin, and the first support part and the second support part are located below the cabin. With this configuration, wiring between one or both of the first power converter and the second power converter and electrical equipment installed around the cabin can be shortened.

[0021] (12) Preferably, in the work machine of (11), the vehicle body has rear wheels on both sides of the body frame in the vehicle width direction, and the first support portion and the second support portion are located between one of the pair of rear wheels and the body frame. According to the above configuration, the first power converter and the second power converter are covered from both sides in the vehicle width direction and protected from external damage.

[0022] (13) In the working machine of (6) in which the first support portion and the second support portion are each formed of separate members, the support structure preferably has a first bolt that fixes the first support portion to the base portion, a second bolt that fixes the second support portion to the base portion, and a third bolt that connects the first support portion to the second support portion. According to the above configuration, the first support portion and the second support portion are connected by the third bolt, and the first support portion and the second support portion are stably attached to the base portion.

[0023] (14) Preferably, in the work machine of any one of (1) to (13), the first electric power converter is located more inward in the vehicle width direction than the second electric power converter, the second support portion has a second inner frame as the second upright portion located more inward in the vehicle width direction than the second electric power converter, the outer side of the second support portion in the vehicle width direction is open, and the support structure has a cover that covers the second electric power converter supported by the second support portion from the outer side in the vehicle width direction. According to this configuration, by removing the cover, the second electric power converter can be seen while attached to the base portion via the second support portion. This facilitates maintenance of the second electric power converter.

[0024] (15) Preferably, in the work machine of (14), the first support portion has, as the first upright portion, a first inner frame located on the inside of the first power converter in the vehicle width direction, and the outside in the vehicle width direction is open. With this configuration, by removing the cover and the second support portion that supports the second power converter, the first power converter can be viewed while attached to the base portion via the first support portion. This makes maintenance of the first power converter easier.

[0025] <Details of Embodiments of the Present Disclosure> Hereinafter, details of embodiments of the present disclosure will be described with reference to the drawings. Note that at least some of the embodiments described below may be combined in any manner.

[0026] [Overall structure of work machine] Figure 1 is a perspective view showing an example of the overall structure of a work machine. Figure 2 is a left side view of the work machine shown in Figure 1. Figure 3 is a bottom view of the work machine shown in Figure 1. Figure 4 is a right side view of the work machine with some of the exterior parts (bonnet 34, cover 111, etc.) removed. The work machine of this embodiment is a work vehicle used for agricultural work, and more specifically, a tractor. The work machine is not limited to tractors, and may be a mobile body such as a construction machine or a utility vehicle. Below, a case will be described in which the work machine is a work vehicle (tractor) 10.

[0027] The directions of the work vehicle 10 are defined. The work vehicle 10 has a driver's seat 15. The front-rear, left-right, and up-down directions of the work vehicle 10 are defined based on the driver seated in the driver's seat 15. In other words, the direction forward for the driver is "front," and the direction behind is "rear." The right direction for the driver is "right," and the left direction is "left." The front-rear and left-right directions are parallel to the ground, and are perpendicular to the front-rear and left-right directions. The up-down direction is perpendicular to both the front-rear and left-right directions.

[0028] The left-right direction may be referred to as the "vehicle width direction." The forward direction is the "traveling direction" of the work vehicle 10. If the work vehicle 10 does not have a driver's seat 15, the direction in which work proceeds on the work vehicle 10 is the "forward," and the opposite direction is the "rear." Facing the direction in which work proceeds, the right side of the work vehicle 10 is the "right," and the left side is the "left."

[0029] The vehicle body 11 of the work vehicle 10 has a chassis 41, a drive unit 14, a driver's seat 15, a cabin 16, a bonnet 34, a cover 111, a tank unit 21, a first radiator 48, and a second radiator 49. From the front to the rear of the vehicle body 11, the bonnet 34 and the cover 111 are mounted on the chassis 41, and the cabin 16 is disposed behind the cover 111.

[0030] The cabin 16 has front pillars, rear pillars, and a roof, and is a driver's compartment defined by these. The work vehicle 10 may have a canopy or roofing instead of the cabin 16. If the work vehicle 10 does not have a cabin 16, the tank unit 21 is disposed above the driver's seat 15 by the mounting frame 17.

[0031] 4, a first radiator 48, a fuel cell 24, and a second radiator 49 are mounted in this order from front to rear on the front part of the chassis 41. 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 111.

[0032] The tank unit 21 has a tank 13 (see FIG. 4 ) therein that stores fuel. The fuel may be liquid or gas, such as hydrogen, methane, or carbon monoxide (CO). In this embodiment, the tank 13 stores hydrogen gas. The drive unit 14 is driven by the stored fuel. The work vehicle 10 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 its energy source. The fuel cell 24 may also generate electricity using methane or carbon monoxide (CO).

[0033] The drive device 14 (see FIG. 5) has a fuel cell 24, a battery unit 30, and a motor 31. The battery unit 30 has a battery pack (battery) that stores the power generated by the fuel cell 24. The work vehicle 10 has a hydrogen gas pipe 22. Hydrogen gas is supplied from a fill port 42 (see FIG. 6) connected to the end of the pipe 22 and filled into the tank 13. The hydrogen gas in the tank 13 is supplied to the fuel cell 24 through the pipe 22.

[0034] The travelling device 12 of the work vehicle 10 has front wheels 12A and rear wheels 12B. The front wheels 12A and rear wheels 12B are arranged symmetrically on the left and right sides of the vehicle body 11. One or both of the front wheels 12A and 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).

[0035] [Internal Structure of Work Vehicle] Figure 5 is a perspective view showing an example of the internal structure of the work vehicle 10. The chassis 41 is configured with a steel frame that is long in the front-to-rear direction, and has a front frame 32 and a gear case 33. The gear case 33 is connected to the rear of the front frame 32. The gear case 33 and the front frame 32 form the framework of the vehicle body 11. The chassis 41 is a body frame on which the drive unit 14, driver's seat 15, cabin 16, etc. are mounted.

[0036] A mounting frame 17 for the tank unit 21 is connected to the chassis 41. The mounting frame 17 supports the tank unit 21 above the cabin 16. 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 17B that support the ceiling frame 17A from below, and a pair of left and right reinforcing frames 17C that are connected to the front end of the ceiling frame 17A.

[0037] The tank unit 21 is connected to the ceiling frame 17A. 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. The mounting frame 17 has the reinforcing frame 17C, which increases the rigidity of the mounting frame 17 in the front-to-rear direction.

[0038] A support frame 37 is connected to the chassis 41, and the battery unit 30 is supported on the vehicle body 11 by the support frame 37. 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.

[0039] The gear case 33, located behind 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 gear case 33 includes a branching mechanism that outputs a portion of the power of the motor 31 to a PTO shaft 334 (see FIG. 4). The PTO shaft 334 is an output shaft that protrudes from the rear of the gear case 33.

[0040] The work vehicle 10 has a coupling device 43 (see FIGS. 3 and 4) for coupling a work implement 19 (see FIG. 6) for performing a desired agricultural task to the rear of the vehicle body 11. The work implement 19 is also called an implement. Examples of the work implement 19 include a cultivator and a baler. The rotational motion of the PTO shaft 334 is transmitted to the input shaft of the work implement 19, for example, while the work vehicle 10 is traveling. The work vehicle 10 can drive the work implement 19 with the power of the motor 31 while traveling in a field or the like.

[0041] [Functional Configuration of Work Vehicle] Figure 6 is a block diagram showing an example of the functional configuration of the work vehicle 10. As shown in Figure 6, the functional systems of the work vehicle 10 include a fuel system FS, a power system PS, and a temperature control system TS.

[0042] Components of the fuel system FS include the tank 13 and the valve unit 45. Components of the temperature control system TS include a first radiator 48, a second radiator 49, and an air conditioning device 37. Components of the power system PS include the fuel cell 24, a boost circuit 28, a DC / DC converter (first power converter) 26, an inverter (second power converter) 27, a motor 31, a gear case 33, and a battery unit 30. Hereinafter, the DC / DC converter 26 will also be referred to as the "converter 26." In this embodiment, the converter 26 is configured to include a first DC / DC converter 26A (also referred to as the "first converter 26A") and a second DC / DC converter 26B (also referred to as the "second converter 26B").

[0043] The tank 13 is connected to the first pipe 22A and the second pipe 22B via the valve unit 45. The first pipe 22A is a gas pipe that connects the fill port 42 and the valve unit 45, and guides the hydrogen gas introduced into the fill port 42 to the tank 13. The second pipe 22B is a gas pipe that connects the fuel cell 24 and the valve unit 45, and guides the hydrogen gas stored in the tank 13 to the fuel cell 24.

[0044] The valve unit 45 is an assembly of valves including an on-off valve and a pressure reducing valve. The valve unit 45 controls the operation of the internal valves to adjust the flow rate of the hydrogen gas in the tank 13 and output it to the fuel cell 24.

[0045] The motor 31 has a rotor and a stator with multiple coils, and drives the output shaft at a predetermined torque and rotational speed. In the present embodiment, only one motor 31 is mounted on the work vehicle 10, and the rotating shaft of the motor 31 is coupled to the gear case 33. The power transmission mechanism of the gear case 33 outputs a portion of the power of the motor 31 to the traveling device 12, and outputs the remainder of the power of the motor 31 to the PTO shaft 334.

[0046] The fuel cell 24 is, for example, a battery module in which a plurality of unit cells, each having a positive electrode and a negative electrode, are stacked side by side within a casing. The fuel cell 24 aggregates the electric power generated by each unit cell to generate the electric power required to drive the motor 31. The fuel cell 24 is connected to the second radiator 49 through a cooling flow path H2. That is, the fuel cell 24 is adjusted to a predetermined temperature by the coolant circulated from the second radiator 49.

[0047] The fuel cell 24 is electrically connected to a boost circuit 28, which is electrically connected to an inverter 27. The boost circuit 28 boosts the voltage input from the fuel cell 24 and outputs it to the inverter 27. The inverter 27 is electrically connected to a motor 31. The inverter 27 converts the direct current input from the boost circuit 23 into three-phase alternating current and outputs it to the motor 31. The power generated by the fuel cell 24 is boosted and converted into alternating current and transmitted to the motor 31.

[0048] The work vehicle 10 has low-voltage 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. Examples of the low-voltage electrical components include the battery unit 30, the first radiator 48, the second radiator 49, and the air conditioning device 37. The step-down circuit is, for example, a converter 26, and in this embodiment, this is a first converter 26A and a second converter 26B.

[0049] The first converter 26A steps down the DC voltage input from the boost circuit 28 and supplies it to the battery unit 30 and the air conditioner 37. The second converter 26B steps down the DC voltage input from the boost circuit 28 and supplies it to the first radiator 48 and the second radiator 49.

[0050] The inverter 27 and the converter 26 (first converter 26A and second converter 26B) are attached to a chassis 41 (see FIG. 3) that serves as a vehicle body frame by a support structure 50. The inverter 27 and the converter 26 are mounted near the driver's seat 15 (see FIG. 2).

[0051] The battery unit 30 is a power storage device that temporarily stores power to be supplied to the motor 31. The battery unit 30 has a battery pack 30A (see FIG. 6). The battery pack 30A includes at least one battery. The battery is, for example, a rechargeable secondary battery such as a lithium-ion battery or a lead-acid battery.

[0052] As described above (see FIG. 4 ), 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. The first radiator 48 and the second radiator 49 are included in a cooling system that uses a refrigerant (cooling liquid) to cool, in addition to the fuel cell 24, electrical components such as the motor 31, the boost circuit 28, the inverter 27, the first converter 26A, and the second converter 26B, which operate using electric power as energy.

[0053] A cooling flow path H1, through which a refrigerant is circulated by a pump 46, is connected to the first radiator 48, and the refrigerant is cooled by heat exchange with external air. The first radiator 48 has a first fan 35 for promoting heat exchange with external air. The temperature adjustment unit including the first radiator 48 and the cooling flow path H1 cools electrical components (heat-generating components), such as the motor 31, the boost circuit 28, the inverter 27, the first converter 26A, and the second converter 26B.

[0054] A cooling flow path H2, through which a coolant is circulated by a pump 47, 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 temperature adjustment unit including the second radiator 49 and the cooling flow path H2 is the fuel cell 24.

[0055] [Regarding the Support Structure 50] As described above (see FIG. 2 ), the inverter 27 and the converter 26 are mounted near the driver's seat 15. The vehicle body 11 has a support structure 50. The support structure 50 attaches the converter 26 and the inverter 27 to the chassis 41, which is the body frame. In this embodiment, the converter 26 includes a first converter 26A and a second converter 26B.

[0056] Fig. 7 is a perspective view of the support structure 50 as seen from the outside in the vehicle width direction. Fig. 8 is an exploded view of the support structure 50 shown in Fig. 7. Fig. 9 is a perspective view of the support structure 50 as seen from the inside in the vehicle width direction. As shown in Fig. 9, the converter 26 has a plurality of terminals (connecting portions) 28A on its front surface, and a plurality of harnesses 38A are connected to the converter 26. The inverter 27 has a plurality of terminals (connecting portions) 28B on its front surface, and a plurality of harnesses 38B are connected to the inverter 27. In Fig. 9, the harnesses 38A and 38B are indicated by imaginary lines (two-dot chain lines).

[0057] In FIG. 8 , the support structure 50 has a base portion 53 , a first support portion 51 , a second support portion 52 , and a cover 54 .

[0058] The base portion 53 is attached to a part of the chassis 41 (see FIG. 7), which is the body frame. In the present embodiment (see FIG. 3), the base portion 53 is attached to the bottom of the gear case 33 of the chassis 41 with a bolt 90A (see FIG. 7). As shown in FIG. 8, the base portion 53 has a base main body 531 that is long in the front-rear direction and an arm 532 that is long in the vehicle width direction. The arm 532 is a member that connects the base main body 531 to the gear case 33.

[0059] The base portion 53 has a first support pillar 533 and a second support pillar 534. The first support pillar 533 and the second support pillar 534 are provided to stand up from the base main body 531. The first support pillar 533 supports the harness 38A connected to the converter 26 (see FIG. 9 ). The second support pillar 534 supports the harness 38B connected to the inverter 27.

[0060] The first support part 51 is attached to the base part 53 (base main body 531). The first support part 51 supports the converter 26, which is a first power converter. The first support part 51 has a frame structure made of metal plates. As shown in FIG. 8 , the first support part 51 has a first inner frame 511, a first upper frame 512, a first lower frame 513, and a first rear frame 514, each of which has a plate shape.

[0061] The first lower frame 513 is placed on the base main body 531 and fixed with bolts 90C. The space enclosed by the first inner frame 511, the first upper frame 512, the first lower frame 513, and the first rear frame 514 is the storage space for the converter 26. The first support portion 51 has an opening toward the front, and the harness 38A (see FIG. 9) extends from the opening.

[0062] The first support portion 51 supports the first converter 26A and the second converter 26B aligned in the vertical direction. The first converter 26A and the second converter 26B are each fixed to the first support portion 51 with bolts 90B (see FIG. 8 ). The first inner frame 511 has an open window frame 511a and is provided with (a plurality of) holes penetrating in the plate thickness direction to provide a heat dissipation measure for the converter 26.

[0063] In this way, the first support portion 51 has the first inner frame 511 as a first standing portion that stands up from the base main body 531 of the base portion 53. The converter 26 is attached to and supported by the first inner frame 511.

[0064] The second support part 52 is attached to the base part 53 (base main body 531). The second support part 52 supports the inverter 27, which is a second power converter. The second support part 52 has a frame structure made of metal plates. The second support part 52 has a second inner frame 521, a second lower frame 523, and a second rear frame 524, each of which is plate-shaped.

[0065] The second lower frame 523 is placed on the base body 531 and fixed with bolts 90D. The space enclosed by the second inner frame 521, the second lower frame 523, and the second rear frame 524 is the accommodation space for the inverter 27. The second support portion 52 has an opening toward the front, and a harness 38B (see FIG. 9) extends from the opening.

[0066] The second support portion 52 supports the inverter 27. The inverter 27 is fixed to the second support portion 52 with bolts 90E (see FIG. 8 ). The second inner frame 521 has an open window frame 521 a and is provided with (a plurality of) holes penetrating in the plate thickness direction, thereby providing a heat dissipation measure for the inverter 27.

[0067] In this way, the second support portion 52 has the second inner frame 521 as a second standing portion that stands up from the base main body 531 of the base portion 53. The inverter 27 is attached to and supported by the second inner frame 521.

[0068] The work vehicle 10 of this embodiment has two converters 26 and one inverter 27. Note that the converter 26 may be a single converter, and the inverter 27 may be configured as two separate inverters.

[0069] The first support portion 51 and the second support portion 52 mounted on the base portion 53 are called a support unit 50U (see FIG. 9 ). That is, the support unit 50U includes the first support portion 51 and the second support portion 52. On the base portion 53, the first support portion 51 and the second support portion 52 are arranged side by side in the vehicle width direction. The cover 54 covers the support unit 50U from the side of the vehicle.

[0070] 2, the vehicle body 11 has a cabin 16. The support unit 50U (first support portion 51 and second support portion 52) is located below the cabin 16. This shortens the wiring between the converter 26 and the inverter 27 supported by the first support portion 51 and the second support portion 52 and electrical components (e.g., the air conditioning unit 37) installed around the cabin 16.

[0071] The vehicle body 11 has rear wheels 12B on both sides in the vehicle width direction of a chassis 41, which is a body frame (see FIG. 3). The first support portion 51 and the second support portion 52 are located between one of the pair of rear wheels 12B (the left rear wheel 12B) and the chassis 41, which is a body frame (gear case 33). With this configuration, the converter 26 and the inverter 27 are covered from both sides in the vehicle width direction and protected from external damage.

[0072] To further explain the configuration of each part of the support structure 50, the shapes of the converter 26 and the inverter 27 will be described. As shown in Fig. 8 , the converter 26 (first converter 26A, second converter 26B) and the inverter 27 of this embodiment are each formed in a box shape. The converter 26 (first converter 26A, second converter 26B) has a shape that fits within a flattened imaginary rectangular parallelepiped Q1. The inverter 27 has a shape that fits within a flattened imaginary rectangular parallelepiped Q2.

[0073] The first support portion 51 supports the converter 26 such that the surface q1 having the largest area in the rectangular parallelepiped Q1 of the converter 26 is the side surface facing horizontally. To this end, the first inner frame 511, which is the first upright portion, faces one surface of the box-shaped converter 26 and has a first mounting surface 511b to which the one surface side is attached.

[0074] The second support portion 52 supports the inverter 27 such that the surface q2 having the largest area in the rectangular parallelepiped Q2 of the inverter 27 is the side surface facing horizontally. To this end, the second inner frame 521 serving as the second upright portion faces one surface of the box-shaped inverter 27 and has a second mounting surface 521b to which the one surface side is attached.

[0075] The first support portion 51 (first inner frame 511 as a first upright portion) that supports the converter 26 is installed so as to rise from the base portion 53. Together with the first support portion 51, the second support portion 52 (second inner frame 521 as a second upright portion) that supports the inverter 27 is installed so as to rise from the base portion 53. Due to this arrangement of the first support portion 51 and the second support portion 52, as shown in FIG. 9 , the support structure 50 (support unit 50U) becomes smaller in the horizontal direction (vehicle width direction).

[0076] In this embodiment (see FIG. 8 ), the first support portion 51 and the second support portion 52 are each formed of separate members. The first support portion 51 and the second support portion 52 can be attached separately to the base portion 53. The first support portion 51 is fixed to the base portion 53 by a bolt 90C. The second support portion 52 is fixed to the base portion 53 by a bolt 90D. In other words, the support structure 50 has a first bolt 90C that fixes the first support portion 51 to the base portion 53 and a second bolt 90D that fixes the second support portion 52 to the base portion 53.

[0077] The first support portion 51 supporting the converter 26 is installed to stand up from the base portion 53, and the second support portion 52 supporting the inverter 27 is installed to stand up from the base portion 53. The first support portion 51 and the second support portion 52 are narrow and vertically long. The first support portion 51 has a first flange plate 515, and the second support portion 52 has a second flange plate 525. The support structure 50 has a third bolt 90F that connects the first support portion 51 and the second support portion 52 (see FIG. 7 ). The first flange plate 515 and the second flange plate 525 are connected by the third bolt 90F. Therefore, although the first support portion 51 and the second support portion 52 are narrow and vertically long, they are stably attached to the base portion 53.

[0078] The cover 54 covers the support unit 50U from the side of the vehicle. More specifically, the cover 54 covers the support unit 50U from the outside in the vehicle width direction. Even if a foreign object is scattered onto the support unit 50U from outside the vehicle body 11, the cover 54 protects the support unit 50U from the foreign object.

[0079] The cover 54 has a side wall 541 and an upper wall 542. The side wall 541 covers the support unit 50U from the outside in the vehicle width direction. The upper wall 542 covers the support unit 50U from above. The cover 54 is made of metal and is formed by bending a plate material. The upper wall 542 and the side wall 541 are integral with each other. The front of the cover 54 is open.

[0080] 9, harnesses 38A and 38B extend from a front opening of cover 54. Cover 54 covers the connection portion (terminal 28A) between converter 26 and harness 38A, and the connection portion (terminal 28B) between inverter 27 and harness 38B. The connection portions of harnesses 38A and 38B are covered by cover 54 and are protected from foreign matter.

[0081] The first mounting surface 511b of the first inner frame 511 and the second mounting surface 521b of the second inner frame 521 are disposed apart from each other in the width direction of the vehicle body 11. The converter 26 is disposed between the first mounting surface 511b and the second mounting surface 521b.

[0082] In this embodiment (see FIG. 9 ), the converter 26 is located more inward in the vehicle width direction than the inverter 27. FIG. 10 is a perspective view of the support structure 50 with the cover 54 removed. FIG. 11 is a perspective view of the support structure 50 with the second support portion 52 and the inverter 27 removed. The second support portion 52 has a second inner frame 521 located inward in the vehicle width direction of the inverter 27. The inverter 27 is provided along the second inner frame 521. The second support portion 52 does not have a frame located outward in the vehicle width direction of the inverter 27. In other words, when the second support portion 52 is attached to the base portion 53, the outer side of the second support portion 52 in the vehicle width direction is open.

[0083] The cover 54 covers the inverter 27 supported by the second support portion 52 from the outer side in the vehicle width direction (see FIG. 7). With this configuration, by removing the cover 54, the inverter 27 can be seen in a state where the inverter 27 is attached to the base portion 53 via the second support portion 52, as shown in FIG. 10. This makes maintenance of the inverter 27 easier.

[0084] The first support portion 51 has a first inner frame 511 located on the inner side of the converter 26 in the vehicle width direction (see FIGS. 9 and 11). The two converters 26 are provided along the first inner frame 511. As shown in FIG. 11, the first support portion 51 does not have a frame located on the outer side of the converter 26 in the vehicle width direction. In other words, when the first support portion 51 is attached to the base portion 53, the outer side of the first support portion 51 in the vehicle width direction is open.

[0085] According to this configuration, by removing the cover 54 and the second support portion 52 supporting the inverter 27, the converter 26 can be seen while attached to the base portion 53 via the first support portion 51. This facilitates maintenance of the converter 26. The first support portion 51 and the second support portion 52 are arranged side by side in the vehicle width direction. Therefore, the second support portion 52 supporting the inverter 27 covers the converter 26 from the outside in the vehicle width direction.

[0086] As described above (see FIG. 2 ), the vehicle body 11 that is capable of traveling has the chassis 41 that serves as a body frame, and a support structure 50 for attaching the converter 26 and the inverter 27 to the chassis 41. The support structure 50 (see FIGS. 7 and 8 ) has a base portion 53 attached to the chassis 41, a first support portion 51 attached to the base portion 53 and supporting the converter 26, and a second support portion 52 attached to the base portion 53 and supporting the inverter 27. The first support portion 51 that supports the converter 26 and the second support portion 52 that supports the inverter 27 are attached by being placed on the base portion 53 that is attached to the inverter 27. The converter 26 and the inverter 27 can be easily assembled and maintained.

[0087] 8 and 9, as described above, the first support portion 51 and the second support portion 52 are formed of separate members. This configuration allows the converter 26 and the inverter 27 to be attached and detached separately.

[0088] Fig. 12 is a perspective view showing a first modified example of the support structure 50. Fig. 13 is a perspective view showing the support structure 50 of Fig. 12 in an exploded state. In the first modified example, the first support portion 51, the second support portion 52, and a base main body 531 that is part of the base portion 53 are configured as a single member. The second inner frame 521 of the second support portion 52 is fixed to the base main body 531 by welding, for example, and stands upright from the base main body 531. The first inner frame 511 of the first support portion 51 is fixed to the base main body 531 by welding, for example, and stands upright from the base main body 531.

[0089] The first support portion 51, the second support portion 52, and the base main body 531 are integrated, and can be attached and detached as a unit from the vehicle main body 11 (arm 532). In the first modified example shown in Figures 12 and 13, the same components as those shown in Figures 7 and 8 are denoted by the same reference numerals.

[0090] 14 and 15 are perspective views showing yet another modified example (second modified example) of the support structure 50. In the second modified example, as in the first modified example, the first support portion 51, the second support portion 52, and a base main body 531 that is part of the base portion 53 are configured as a single member. The second inner frame 521 of the second support portion 52 is fixed to the base main body 531 by welding, for example, and stands upright from the base main body 531. The first inner frame 511 of the first support portion 51 is fixed to the base main body 531 by welding, for example, and stands upright from the base main body 531.

[0091] In the second modified example shown in Figures 14 and 15, the same components as those in the embodiment shown in Figures 7 and 8 are denoted by the same reference numerals. In the second modified example, the number of converters 26 is one.

[0092] In the first modified example ( FIGS. 12 and 13 ) and the second modified example ( FIGS. 14 and 15 ), similar to the embodiment shown in FIGS. 7 and 8 , the support structure 50 has a base portion 53, a first support portion 51, and a second support portion 52. The base portion 53 is a portion that is attached to the chassis (body frame) 41. The base portion 53 has a base main body 531 and an arm 532.

[0093] The first support part 51 has a first inner frame 511 as a first upright part that stands up from the base main body 531. The converter 26 is attached to and supported by the first inner frame 511. The second support part 52 has a second inner frame 521 as a second upright part that stands up from the base main body 531. The inverter 27 is attached to and supported by the second inner frame 521.

[0094] In the first modified example ( FIGS. 12 and 13 ) and the second modified example ( FIGS. 14 and 15 ), the converter 26 and the inverter 27 are each formed in a box shape, similar to the embodiments shown in FIGS. 7 and 8 . The first inner frame 511 faces one side of the box-shaped converter 26 and has a first mounting surface 511b to which one side is attached. The second inner frame 521 faces one side of the box-shaped inverter 27 and has a second mounting surface 521b to which one side is attached. The first mounting surface 511b and the second mounting surface 521b are spaced apart in the width direction of the vehicle main body 11. The converter 26 is disposed between the first mounting surface 511b and the second mounting surface 521b. The inverter 27 is disposed on the outer side of the second mounting surface 512b in the vehicle width direction.

[0095] [Others] The above-described embodiments are illustrative in all respects and are not limiting. The scope of the present invention is indicated by the claims, not by the above-described embodiments, and includes all modifications within the scope equivalent to the configurations described in the claims. The symbols used in Chapter 1 are used only in this Chapter and are unrelated to the symbols in other chapters.

[0096] [Explanation of symbols] 10 Work vehicle (work machine) 11 Vehicle body 12B Rear wheel 16 Cabin 24 Fuel cell 26 Converter (first power converter) 26A First converter (first power converter) 26B Second converter (first power converter) 27 Inverter (second power converter) 28A Terminal (connecting portion) 28B Terminal (connecting portion) 30A Battery pack (battery) 31 Motor 38A Harness 38B Harness 41 Chassis (vehicle body frame) 50 Support structure 50U Support unit 51 First support portion 52 Second support portion 53 Base portion 54 Cover 90C Bolt (first bolt) 90D Bolt (second bolt) 90F Third bolt 511 First inner frame (first standing portion) 511b First mounting surface 521 Second inner frame (second standing portion) 521b second mounting surface

[0097] <Chapter 2> <Problem to be Solved by the Present Disclosure> Conventional work vehicles are equipped with numerous devices, including auxiliary devices associated with fuel cells. Therefore, there is a problem that the overall size of the work vehicle increases when these devices are installed on the vehicle. An object of the present disclosure is to prevent the size of work vehicles equipped with fuel cells from increasing.

[0098] <Effects of the Present Disclosure> According to the present disclosure, it is possible to prevent a work vehicle equipped with a fuel cell from becoming larger in size.

[0099] <Outline of Embodiments of the Present Disclosure> An outline of embodiments of the present disclosure will be listed and described below. <Outline of Embodiments of the Present Disclosure> An outline of embodiments of the present disclosure will be listed and described below. (1) A work vehicle of this embodiment includes a vehicle body having a motor, a working device operated by power of the motor, a support body supporting a transmission shaft that transmits power from the motor to the working device, and a pair of vertical frames connected to a front side of the support body and arranged spaced apart from each other in the vehicle width direction, electrical equipment including a battery unit that stores power supplied to the motor, a fuel cell provided above the pair of vertical frames and generating power to be stored in the battery unit, auxiliary equipment associated with the fuel cell, and a hood that covers the fuel cell, and at least one of the electrical equipment and the auxiliary equipment is arranged between the pair of vertical frames.

[0100] With the above-described work vehicle, the space between the pair of vertical frames on which the fuel cell is mounted on the upper side of the vehicle body can be effectively used as a space for arranging at least one of the electrical equipment and auxiliary equipment, thereby preventing the work vehicle equipped with a fuel cell from becoming larger.

[0101] (2) In the work vehicle described in (1) above, it is preferable that the at least one device is disposed between the pair of vertical frames and below the fuel cell. In this case, the space between the pair of vertical frames and below the fuel cell can be effectively used as a space for disposing at least one device selected from the electrical equipment and auxiliary equipment.

[0102] (3) In the work vehicle described in (1) or (2), the electrical equipment includes the battery unit, an inverter that converts DC power into AC power and outputs it to the motor, and a voltage converter that reduces the voltage of the power input from the battery unit, and it is preferable that the at least one device arranged between the pair of vertical frames is any one of the battery unit, the inverter, and the voltage converter.

[0103] In this case, the electrical equipment (battery unit, inverter, or voltage converter) is disposed between the pair of vertical frames, so the space between the pair of vertical frames can be effectively used as a space for arranging the electrical equipment. Furthermore, when the inverter is disposed between the pair of vertical frames, the wiring length between the fuel cell and the inverter can be shortened. Furthermore, when the battery unit and the voltage converter are disposed between the pair of vertical frames, the wiring length between the battery unit and the voltage converter can be shortened.

[0104] (4) In the work vehicle described in (1) or (2), the auxiliary equipment includes a radiator that cools the coolant, a fan that supplies airflow to the radiator, an air cleaner that purifies the air supplied to the fuel cell, an ion exchanger that removes ions from the coolant, and a hydrogen detector that detects hydrogen leaked from the hydrogen supply path to the fuel cell, and it is preferable that the at least one device arranged between the pair of vertical frames is any one of the radiator, fan, air cleaner, ion exchanger, and hydrogen detector.

[0105] In this case, any of the auxiliary equipment, such as the radiator, fan, air cleaner, ion exchanger, or hydrogen detector, is disposed between the pair of vertical frames, so the space between the pair of vertical frames can be effectively used as space for arranging the auxiliary equipment. Furthermore, if the air cleaner is disposed between the pair of vertical frames, the length of the air flow path between the air cleaner and the fuel cell can be shortened. Furthermore, if the ion exchanger is disposed between the pair of vertical frames 321, the length of the coolant flow path between the ion exchanger and the fuel cell can be shortened.

[0106] <Details of Embodiments of the Present Disclosure> Hereinafter, details of embodiments of the present disclosure will be described with reference to the drawings. Note that at least some of the embodiments described below may be combined in any manner.

[0107] [Overall Configuration of Work Vehicle] Figure 16 is a perspective view showing one embodiment of a work vehicle according to the present disclosure. Figures 17 to 21 are a front view, a rear view, a side view (right side view), a side view (left side view), and a plan view of the work vehicle shown in Figure 16. The work vehicle 10 of this embodiment is a vehicle that can be used for agricultural work, and the work vehicle 10 shown in Figure 16 is a tractor. The work vehicle is not limited to a tractor. For example, the work vehicle according to the present disclosure may be an agricultural machine, a construction machine, a utility vehicle, or the like other than a tractor.

[0108] The directions of the work vehicle 10 of the present disclosure are defined below. The direction in which the work vehicle 10 moves forward is defined as "front," the direction in which the work vehicle 10 moves backward is defined as "rear," the left side of the work vehicle 10 facing forward is defined as "left," and the right side of the work vehicle 10 facing forward is defined as "right." The front-to-rear direction of the work vehicle 10 is defined as the vehicle front-to-rear direction. The left-to-right direction perpendicular to the vehicle front-to-rear direction is defined as the vehicle width direction. The direction perpendicular to both the vehicle front-to-rear direction and the vehicle width direction is defined as the up-to-down direction. The up-to-down direction is also called the height direction. In each figure, orthogonal three-dimensional coordinates are shown, with the front direction indicated by arrow X1 and the rear direction indicated by arrow X2. The left direction is indicated by arrow Y1 and the right direction is indicated by arrow Y2. The up direction is indicated by arrow Z1 and the down direction is indicated by arrow Z2.

[0109] 16 includes a vehicle body 11, a traveling device 12 that supports the vehicle body 11 so that it can travel, a driver's seat 15, a cabin 16, a tank unit 21, a fuel cell (fuel cell module) 24, a battery unit 30, and an electric motor 31. The tank unit 21 has a tank 13 that stores fuel. The fuel is a liquid or gas, such as hydrogen, methane, or carbon monoxide (CO). In this embodiment, the tank 13 stores hydrogen gas.

[0110] The work vehicle 10 of this embodiment is a fuel cell vehicle (FCV) that runs on electricity generated by a fuel cell 24 using hydrogen and oxygen. The fuel cell 24 generates electricity that is stored in a battery unit 30. The fuel cell 24 may generate electricity using methane or carbon monoxide (CO) as fuel. The electricity stored in the battery unit 30 is supplied to a motor 31.

[0111] The work vehicle 10 is equipped with piping for hydrogen gas (hydrogen piping) 22 and a filling unit 25 (see FIG. 18 ). The filling unit 25 has a filling port (receptacle) 26 to which a filling nozzle of a hydrogen gas supply device (not shown) that is separate from the work vehicle 10 is connected. Hydrogen gas is supplied from the filling port 26 and supplied to the tank 13 through piping 22 (rear piping 22r). The hydrogen gas in the tank 13 is supplied to the fuel cell 24 through piping 22 (front piping 22f).

[0112] The work vehicle 10 (see FIG. 16 ) includes a mounting frame 17. The mounting frame 17 is a frame for mounting a tank unit 21 (tank 13) on the vehicle body 11. The specific configuration of the mounting frame 17 will be described later.

[0113] [Vehicle Body] The vehicle body 11 has a chassis 41, a hood 34, a cover 111, and a fender 47. The fender 47 covers the rear wheel 122 from above. The chassis 41 supports the traveling device 12, the cabin 16, the fuel cell 24, the battery unit 30, and the motor 31. Figure 22 is an exploded perspective view of a portion of the work vehicle 10 shown in Figure 16. The chassis 41 is located in the center in the vehicle width direction and has a shape that is long in the vehicle front-to-rear direction. The chassis 41 has a front frame 32 that forms the front part of the chassis 41, and a transmission case (support body) 33 that forms the rear part of the chassis 41.

[0114] The front frame 32 is formed by combining metal frame materials and the like. In this embodiment, the front frame 32 has a pair of vertical frames 321, a first horizontal frame 322, a second horizontal frame 323, and a third horizontal frame 324. The pair of vertical frames 321 are connected to the front side of the transmission case 33. The pair of vertical frames 321 are disposed spaced apart from each other in the vehicle width direction and extend in the vehicle front-rear direction.

[0115] The first horizontal frame 322 is fixed to the rear portions of the pair of vertical frames 321 behind the front wheels 121. A motor 31 is mounted on the rear portions of the pair of vertical frames 321 and on the first horizontal frame 322. The second horizontal frame 323 is fixed to the front portions of the pair of vertical frames 321 in front of the front wheels 121. Both ends of the first horizontal frame 322 and the second horizontal frame 323 in the vehicle width direction extend outward in the vehicle width direction beyond the pair of vertical frames 321. The third horizontal frame 324 connects the front ends of the pair of vertical frames 321 to each other. The dimension of the third horizontal frame 324 in the vehicle width direction is the same as the dimension of the pair of vertical frames 321 in the vehicle width direction.

[0116] The transmission case 33 has a metal box body. The transmission case 33 is connected to the rear side of the front frame 32, and the transmission case 33 and the front frame 32 form the framework of the vehicle body 11. The transmission case 33 has a power transmission mechanism therein, such as a transmission, a clutch, and a differential gear. The power transmission mechanism reduces or increases the rotation of the output shaft of the motor 31 and outputs the rotation to the traveling device 12 (either or both of the front wheels 121 and the rear wheels 122).

[0117] The power transmission mechanism outputs a portion of the power of the motor 31 to a PTO shaft (transmission shaft) 334 (see FIG. 18 ). The PTO shaft 334 is an output shaft supported at the rear of the transmission case 33. The work vehicle 10 is equipped with a working device 340 (see FIG. 20 ) and a coupling device 43 for coupling the working device 340 to the rear of the vehicle body 11. The PTO shaft 334 transmits the power of the motor 31 to the working device 340 coupled to the coupling device 43. The working device 340 operates using the power of the motor 31. The working device 340 is, for example, a tiller. The working device 340 is not shown in FIGS. 16 to 19 and 21 to 23 .

[0118] Figure 23 is a right side view of the work vehicle 10, showing the hood 34, cover 111, and a portion of the tank case 211 of the tank unit 21 removed. Starting from the front of the vehicle, the first radiator 48, fuel cell 24, and second radiator 49 are mounted in this order on the front frame 32 of the chassis 41. As shown in Figures 19 and 23, the hood 34 and cover 111 cover the mounted components located near the front of the vehicle body 11. The hood 34 covers the fuel cell 24 and first radiator 48 from above and on both sides in the vehicle width direction. The cover 111 covers the second radiator 49 located behind the fuel cell 24 from above and on both sides in the vehicle width direction.

[0119] The upper surface 111a of the cover 111 is higher than the upper surface 34a of the hood 34, but lower than the upper end of the steering wheel 151 that is operated for steering by an operator sitting in the driver's seat 15. The upper surface 34a of the hood 34 becomes lower toward the front. This makes it less likely that the field of view of the operator sitting in the driver's seat 15 will be obstructed.

[0120] [Driver's Seat and Cabin] The driver's seat 15 and the cabin 16 are provided on the chassis 41 at a rearward position (see FIG. 16 ). The cabin 16 has the driver's seat 15 and a steering wheel 151 inside. The cabin 16 has front pillars 162 located in front of the driver's seat 15, rear pillars 163 located behind the driver's seat 15, and a roof 164 located above the driver's seat 15. The front pillars 162 are provided on the left front and right front of the driver's seat 15. The rear pillars 163 are provided on the left rear and right rear of the driver's seat 15. The roof 164 is supported by the front pillars 162 and the rear pillars 163.

[0121] The cabin 16 has a transparent windshield 165 located in front of the driver's seat 15 and transparent side windows 166 located on both the left and right sides of the driver's seat 15. The windshield 165 is provided between the left and right front pillars 162. The side windows 166 are provided between the front pillar 162 and the rear pillar 163. The side windows 166 can be opened and closed, and function as doors for the operator to enter and exit the cabin 16.

[0122] A step 167 is provided on one side (left side) of the cabin 16 in the vehicle width direction (see FIG. 20 ). The step 167 is a member on which an operator places their feet when getting in and out of the cabin 16. A cover 111 and a bonnet 34 are provided in front of the cabin 16. As shown in FIGS. 17 and 21 , the dimensions of the cover 111 and the bonnet 34 in the vehicle width direction are each smaller than the dimension of the cabin 16 in the vehicle width direction. The dimension of the bonnet 34 in the vehicle width direction is smaller than the dimension of the cover 111 in the vehicle width direction.

[0123] The work vehicle 10 of this embodiment is equipped with a cabin 16, but it does not have to be equipped with the cabin 16. The work vehicle 10 may be equipped with a canopy or ropes instead of the cabin 16. If the work vehicle 10 does not have a cabin 16, the tank unit 21 is mounted on the mounting frame 17 and positioned above the driver's seat 15.

[0124] [Traveling Device] As shown in Figures 21 and 22, the traveling device 12 has front wheels 121 and rear wheels 122. The front wheels 121 are provided on the left and right sides of the front part of the vehicle body 11. The left and right front wheels 121 are rotatably supported at both ends of an axle 123 extending in the vehicle width direction. The axle 123 is disposed below a pair of vertical frames 321 of the vehicle body 11 and is supported by the pair of vertical frames 321. The rear wheels 122 are provided on the left and right sides of the rear part of the vehicle body 11. The maximum dimension in the vehicle width direction of the left and right rear wheels 122 is larger than the maximum dimension in the vehicle width direction of the left and right front wheels 121. The maximum dimension in the vehicle width direction of the left and right rear wheels 122 defines the maximum vehicle width dimension of the work vehicle 10. One or both of the front wheels 121 and the rear wheels 122 rotate by the power of the motor 31. One or both of the front wheels 121 and the rear wheels 122 (drive wheels) that rotate by the power of the motor 31 may be crawlers (crawlers).

[0125] As shown in Figure 23, the fuel cell 24 is provided on the front frame 32 of the chassis 41, above a pair of vertical frames 321 between a first horizontal frame 322 and a second horizontal frame 323. The motor 31 is located behind the fuel cell 24 and below the second radiator 49. The motor 31 has a rotating rotor and a stator having multiple coils. The output shaft of the motor 31 is connected to a power transmission mechanism inside the transmission case 33 (see Figure 22). The battery unit 30 is located below the fuel cell 24. Details of this will be described later.

[0126] The fuel cell 24 generates electricity using hydrogen gas supplied from the battery unit 30 as fuel, and obtains the power to rotate the motor 31. The fuel cell 24 has a battery casing 241 in the shape of a substantially rectangular box, and a fuel cell stack 242 provided inside the battery casing 241. The fuel cell stack 242 has multiple battery cells. Each battery cell has a positive electrode and a negative electrode. The multiple battery cells are stacked. The power generated by each battery cell is collected and output to the battery unit 30.

[0127] [Tank Unit] The tank unit 21 (see FIG. 23 ) includes the tank 13, a tank case 211 that houses the tank 13, and a valve unit 212. The tank 13 is a substantially cylindrical high-pressure container. The tank 13 is made of fiber-reinforced resin reinforced with carbon fiber or glass fiber, or the like. In this embodiment, three tanks 13 are fixed to the tank case 211 with the axial direction of their cylindrical portions parallel to the vehicle width direction. The number of tanks 13 is not limited to three.

[0128] The tank case 211 is a box that can house one or more tanks 13. The tank case 211 has an opening / closing door 213 (see FIG. 16 ) on one or both sides in the vehicle width direction, and is open in the vehicle width direction. The tank case 211 is installed above the roof 164 with a gap between it and the roof 164 in the vertical direction. The tank case 211 is fixed to the upper frame portion 171 of the mounting frame 17. The tank case 211 is made of metal such as aluminum or steel, and protects the tanks 13 from external thermal and physical influences.

[0129] The tank 13 is located above the cabin 16 (driver's seat 15). This allows for a high degree of freedom in the placement of the fuel cell 24, filling section 25, motor 31, and battery unit 30 in the vehicle body 11. When a conventional work vehicle with an internal combustion engine is modified to have a work vehicle 10 equipped with a fuel cell 24 and motor 31 as in this embodiment, there is no need to significantly change the placement and configuration of the various devices.

[0130] The tank 13 is connected to a rear pipe 22r and a front pipe 22f via a valve unit 212 (see FIG. 23). The rear pipe 22r (see FIG. 18) is a gas inlet pipe connecting the hydrogen gas fill port 26 and the valve unit 212, and guides hydrogen gas introduced into the fill port 26 to the tank 13. The front pipe 22f (see FIG. 16) is a gas outlet pipe connecting the fuel cell 24 and the valve unit 212, and guides hydrogen gas stored in the tank 13 to the fuel cell 24. The tank 13 stores hydrogen gas introduced into the fill port 26 from outside the vehicle and supplies it to the fuel cell 24. The valve unit 212 has an on-off valve, a pressure reducing valve, etc., and adjusts the hydrogen gas stored in the tank 13 to a predetermined flow rate and guides it to the fuel cell 24 through the front pipe 22f.

[0131] 16 and 22 , the mounting frame 17 is a frame structure for mounting the tank 13 on the vehicle body 11. The mounting frame 17 in this embodiment has an upper frame portion 171, a pair of front frame portions 172, a rear frame portion 173, and a pair of reinforcing frame portions 175. The upper frame portion 171 is formed in a rectangular frame shape and is located above the cabin 16. A tank case 211 is attached to the upper frame portion 171. In other words, the upper frame portion 171 supports the tank 13 via the tank case 211. The upper frame portion 171 is supported by the front frame portion 172, the rear frame portion 173, and the reinforcing frame portion 175.

[0132] The pair of front frame portions 172 extend in the vertical direction in front of the cabin 16 and on the outer sides of the vehicle body 11 in the vehicle width direction. The upper ends of the pair of front frame portions 172 are fixed to the front left and right corners of the upper frame portion 171, respectively. The lower ends of the pair of front frame portions 172 are fixed to both ends of the first horizontal frame 322 of the chassis 41 in the vehicle width direction, respectively. The rear frame portion 173 is located behind the cabin 16. The rear frame portion 173 is configured in a lattice shape using a plurality of frame members. The upper ends of the rear frame portion 173 are fixed to the rear left and right corners of the upper frame portion 171, respectively. The lower end of the rear frame portion 173 is fixed to the chassis 41. A filling portion 25 is provided in the rear frame portion 173 (see FIG. 18 ).

[0133] The pair of reinforcing frame portions 175 are reinforcing members that absorb the inertial force that causes the upper frame portion 171 and the tank case 211 to move forward when the work vehicle 10 stops while in motion. The pair of reinforcing frame portions 175 are located in front of the front frame portion 172 and on both sides of the hood 34 in the vehicle width direction. The upper ends of the pair of reinforcing frame portions 175 are fixed to the left and right corners on the front side of the upper frame portion 171, respectively. The lower ends of the pair of reinforcing frame portions 175 are fixed to both ends in the vehicle width direction of the second horizontal frame 323 of the chassis 41, respectively (see FIG. 17 ).

[0134] [Electrical Equipment] Figure 24 is a schematic bottom view of the front portion of the work vehicle 10 shown in Figure 16, viewed from below. The hood 34 and cover 111 are not shown in Figure 24. The work vehicle 10 is equipped with electrical equipment 80 that is disposed on the front frame 32 of the chassis 41. The electrical equipment 80 includes a battery unit 30, an inverter 81, a first voltage converter 82, and a second voltage converter 83. Each of these devices 30, 81 to 83 is attached to a pair of vertical frames 321 of the front frame 32.

[0135] The battery unit 30 stores the power supplied to the motor 31. The battery unit 30 has a battery (battery pack) 300 and a battery housing 301 that houses the battery 300. The battery 300 temporarily stores the power generated by the fuel cell 24 and outputs the stored power to electrical devices such as the motor 31. The battery 300 is composed of multiple battery cells. The battery 300 is a charge-discharge type secondary battery such as a lithium-ion battery or a lead-acid battery. The battery housing 301 has a rectangular parallelepiped shape that is long in the front-to-rear direction of the vehicle.

[0136] The inverter 81 is connected to the battery unit 30 via a junction box (not shown). The inverter 81 is also connected to the fuel cell 24 via a boost circuit (not shown). The inverter 81 is electrically connected to the motor 31. The inverter 81 converts the DC power output from the boost circuit into AC power and outputs the AC power to the motor 31.

[0137] The first voltage converter 82 and the second voltage converter 83 constitute a step-down circuit that steps down the power input from the battery unit 30. The first voltage converter 82 is, for example, a 12 V DC / DC converter. The second voltage converter 83 is, for example, a 24 V DC / DC converter. The battery unit 30 is connected to the first voltage converter 82 and the second voltage converter 83 via the junction box.

[0138] The work vehicle 10 is equipped with low-voltage electrical equipment that operates at a lower voltage than the motor 31. In the present embodiment, the low-voltage electrical equipment includes radiators 48, 49, which will be described later, and an air conditioning system (not shown). The low-voltage electrical equipment is supplied with power that has been stepped down by a step-down circuit (voltage converters 82, 83 or a 12V battery) through the junction box.

[0139] Auxiliary Equipment The work vehicle 10 is equipped with auxiliary equipment 90 associated with the fuel cell 24. The auxiliary equipment 90 is disposed on the front frame 32 of the chassis 41. The auxiliary equipment 90 includes a first radiator 48, a second radiator 49, a first fan 51, a second fan 52, an air cleaner 91, an ion exchanger 92, and a hydrogen sensor (hydrogen detection unit) 93. The air cleaner 91, the ion exchanger 92, and the hydrogen sensor 93 are attached to the underside of the battery housing 301 of the battery unit 30.

[0140] The first radiator 48 and the second radiator 49 are configured as part of a cooling system that uses coolant to cool the fuel cell 24, the motor 31, the inverter 81, and the voltage converters 82, 83, etc. As shown in Figures 23 and 24, the first radiator 48 is located in front of the fuel cell 24. The second radiator 49 is located behind the fuel cell 24.

[0141] The first radiator 48 is attached to the pair of vertical frames 321 with most of the first radiator 48, excluding its lower end 48a, being positioned above the pair of vertical frames 321 of the front frame 32. The first radiator 48 is a radiator for cooling devices other than the fuel cell 24. The first radiator 48 is connected to electrical components (heat-generating components) that require cooling, such as the motor 31, the inverter 81, and the voltage converters 82 and 83, via a first cooling flow path (not shown) that has a circulation pump. The first radiator 48 cools the coolant supplied through the first cooling flow path by heat exchange with external air.

[0142] The second radiator 49 is attached to the pair of vertical frames 321 with its entirety positioned above the pair of vertical frames 321. The second radiator 49 is a radiator for cooling the fuel cell 24. The second radiator 49 is connected to the fuel cell 24 via a second cooling flow path (not shown) having a circulation pump. The second radiator 49 cools the coolant supplied through the second cooling flow path by heat exchange with external air. Note that the first radiator 48 may cool the fuel cell 24, and the second radiator 49 may cool devices other than the fuel cell 24.

[0143] The first fan 51 is located in front of the first radiator 48 and attached to the first radiator 48. Most of the first fan 51, excluding a lower end 51a, is disposed above the pair of vertical frames 321 of the front frame 32. The first fan 51 rotates to supply airflow to the first radiator 48 and promote heat exchange with the coolant.

[0144] The second fan 52 is located behind the second radiator 49 and attached to the second radiator 49. The entire second fan 52 is disposed above the pair of vertical frames 321 of the front frame 32. The second fan 52 rotates to supply airflow to the second radiator 49 and promote heat exchange with the coolant.

[0145] The air cleaner 91 purifies the air to be supplied to the fuel cell 24. Although not shown, the air cleaner 91 has an intake port for taking in outside air and an exhaust port for discharging the air that has been purified inside. The exhaust port of the air cleaner 91 is connected to the fuel cell 24 via a piping such as a hose (not shown).

[0146] The ion exchanger 92 is provided midway through the second cooling flow path connecting the fuel cell 24 and the second radiator 49. The ion exchanger 92 is configured with a filter or the like. The ion exchanger 92 removes ions from the coolant flowing through the second cooling flow path. The ions are, for example, ions that have eluted from the piping of the second cooling flow path. By removing ions from the coolant using the ion exchanger 92, the work vehicle 10 can ensure the insulation of the coolant flowing through the second cooling flow path. Note that the ion exchanger 92 may also remove ions from the coolant in the first cooling flow path.

[0147] The hydrogen sensor 93 detects hydrogen leaking from the supply flow path that supplies hydrogen from the tank 13 to the fuel cell 24. In the present embodiment, the supply flow path is the front pipe 22f described above (see also FIG. 16 ). The hydrogen sensor 93 is disposed, for example, near the connection between the front pipe 22f and the fuel cell 24. The work vehicle 10 can use the hydrogen sensor 93 to detect hydrogen leaking from the front pipe 22f.

[0148] 23 and 24 , most of the electrical equipment 80 and auxiliary equipment 90 are arranged between a pair of vertical frames 321 in the front frame 32. In this embodiment, equipment 30, 81 to 83 of the electrical equipment 80 and equipment 48, 51, 91 to 93 of the auxiliary equipment 90 are arranged between the pair of vertical frames 321. Here, "arranged between the vertical frames 321" means not only when the entirety of one equipment is arranged, but also when a part of one equipment is arranged.

[0149] Of the above-mentioned devices arranged between the pair of vertical frames 321, the entirety of each of the devices 30, 81 to 83 of the electrical equipment 80 and the entirety of each of the devices 91 to 93 of the auxiliary equipment 90 are arranged in a lower space 35 formed below the fuel cell 24 between the pair of vertical frames 321. In this embodiment, the battery unit 30 is arranged in the lower space 35, straddling the axle 123 from above, and is arranged biased toward the front.

[0150] The first voltage converter 82 and the second voltage converter 83 are disposed in close proximity to the rear of the battery unit 30 in the lower space 35, and are arranged side by side in the vehicle width direction. The inverter 81 is disposed in close proximity to the rear of the first voltage converter 82 and the second voltage converter 83 in the lower space 35. The inverter 81, the first voltage converter 82, and the second voltage converter 83 each extend in the vehicle width direction.

[0151] The arrangement of the devices 30, 81 to 83 of the electrical equipment 80 is not limited to this embodiment. For example, some or all of the devices 30, 81 to 83 may be arranged in another space 36 (described later) behind the lower space 35 between the pair of vertical frames 321, or may be arranged in another space 36 in front of the lower space 35. Furthermore, it is sufficient that at least one of the devices 30, 81, 82, 83 of the electrical equipment 80 is arranged between the pair of vertical frames 321.

[0152] The first radiator 48 and the first fan 51 of the auxiliary equipment 90 are disposed in the other space 36 between the pair of vertical frames 321, other than below the fuel cell 24. In this embodiment, the lower end portions 48a, 51a of the first radiator 48 and the first fan 51, which are parts of each, are disposed in the other space 36 between the fuel cell 24 and the second horizontal frame 323. The upper sides of the lower end portions 48a, 51a of the first radiator 48 and the first fan 51 protrude upward beyond the pair of vertical frames 321.

[0153] The air cleaner 91 is disposed in the lower space 35 near and to the rear right of the inverter 81. The ion exchanger 92 is disposed in the lower space 35 near and to the rear left of the inverter 81. The hydrogen sensor 93 is disposed in the lower space 35 between the air cleaner 91 and the ion exchanger 92.

[0154] The arrangement of the devices 48, 51, 91 to 93 of the auxiliary device 90 is not limited to this embodiment. For example, the lower ends 48a, 51a of the first radiator 48 and the first fan 51 may be arranged in the other space 36 between the second horizontal frame 323 and the third horizontal frame 324 between the pair of vertical frames 321. A part or all of the devices 91 to 93 may be arranged in the other space 36 behind the lower space 35 between the pair of vertical frames 321, or in the other space 36 in front of the lower space 35. The lower ends of the second radiator 49 and the second fan 52 may be arranged between the pair of vertical frames 321. It is sufficient that at least one of the devices 48, 49, 51, 52, 91, 92, and 93 of the auxiliary device 90 is arranged between the pair of vertical frames 321.

[0155] [Operation and Effect of the Embodiment] According to the work vehicle 10 of this embodiment, the devices 30, 81 to 83 of the electrical equipment 80 and the devices 48, 51, 91 to 93 of the auxiliary equipment 90 are arranged between a pair of vertical frames 321 on the chassis 41, on which the fuel cell 24 is provided on the upper side. This makes it possible to effectively use the space between the pair of vertical frames 321 as a space for arranging the electrical equipment 80 and the auxiliary equipment 90. As a result, it is possible to prevent the work vehicle 10 equipped with the fuel cell 24 from becoming larger.

[0156] The devices 30, 81 to 83 of the electrical device 80 and the devices 91 to 93 of the auxiliary device 90 are arranged in a lower space 35 below the fuel cell 24 between the pair of vertical frames 321. This allows the lower space 35 to be effectively used as a space for arranging the electrical device 80 and the auxiliary device 90.

[0157] The inverter 81 is disposed between a pair of vertical frames 321 on which the fuel cell 24 is mounted, thereby shortening the wiring length between the fuel cell 24 and the inverter 81. Furthermore, the battery unit 30 and the voltage converters 82, 83 are disposed between a pair of vertical frames 321, thereby shortening the wiring length between the battery unit 30 and each of the voltage converters 82, 83.

[0158] The air cleaner 91 is disposed between the pair of vertical frames 321 on which the fuel cell 24 is mounted, thereby shortening the length of the air flow path between the air cleaner 91 and the fuel cell 24. The ion exchanger 92 is disposed between the pair of vertical frames 321 on which the fuel cell 24 is mounted, thereby shortening the length of the coolant flow path between the ion exchanger 92 and the fuel cell 24.

[0159] [Others] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is not limited to the above-described embodiments, but includes all modifications within the scope of equivalents to the configurations described in the claims. The symbols used in Chapter 2 are used only in this Chapter and are unrelated to the symbols in other chapters. The configurations disclosed in Chapter 1 are applicable to the inventions disclosed in Chapter 2, and vice versa.

[0160] [Explanation of symbols] 10 Work vehicle 11 Body 12 Traveling device 13 Tank 15 Driver's seat 16 Cabin 17 Mounting frame 21 Tank unit 22 Pipe 22f Front pipe 22r Rear pipe 24 Fuel cell 25 Filling section 26 Filling port 30 Battery unit 31 Motor 32 Front frame 33 Transmission case (support) 34 Bonnet 34a Top surface 35 Underspace 36 Other space 41 Chassis 43 Connecting device 47 Fender 48 First radiator 48a Lower end 49 Second radiator 51 First fan 51a Lower end 52 Second fan 80 Electrical equipment 81 Inverter 82 First voltage converter 83 Second voltage converter 90 Auxiliary equipment 91 Air cleaner 92 Ion exchanger 93 Hydrogen sensor (hydrogen detection unit) 111 Cover 111a Upper surface 121 Front wheel 122 Rear wheel 123 Axle 151 Steering 162 Front pillar 163 Rear pillar 164 Roof 165 Windshield 166 Side glass 167 Step 171 Upper frame portion 172 Front frame portion 173 Rear frame portion 175 Reinforcement frame portion 211 Tank case 212 Valve unit 213 Openable door 241 Battery casing 242 Fuel cell stack 300 Battery 301 Battery housing 321 Vertical frame 322 First horizontal frame 323 Second horizontal frame 324 Third horizontal frame 334 PTO shaft (transmission shaft) 340 Work device

[0161] <Chapter 3> <Problem to be Solved by the Present Disclosure> A tractor has a heat exchanger (radiator), which exchanges heat with the outside air to cool a heat medium passing through electrical components such as a fuel cell and a battery. Increasing the capacity of the heat exchanger improves its performance. However, there is a limit to how large a heat exchanger can be made due to the installation space. Therefore, an object of the present disclosure is to improve the heat exchange efficiency of a work machine having a heat exchanger.

[0162] <Effects of the Present Disclosure> According to the work machine of the present disclosure, it is possible to improve the heat exchange efficiency of the heat exchanger.

[0163] <Outline of Embodiments of the Present Disclosure> An outline of embodiments of the present disclosure will be listed and described below. (1) A work machine according to an embodiment of the present disclosure includes a machine frame, a fuel cell mounted on the machine frame, electrical equipment mounted on the machine frame, and an auxiliary heat exchanger that performs heat exchange between a first heat medium that adjusts the temperature of the fuel cell and a second heat medium that adjusts the temperature of the electrical equipment.

[0164] In a work machine having the above configuration, for example, when the temperature of the first heat medium that regulates the temperature of the fuel cell is higher than the temperature of the second heat medium that regulates the temperature of the electrical components, the temperature of the first heat medium is lowered by the second heat medium in the auxiliary heat exchanger. The first heat medium, whose temperature has been lowered by the second heat medium, is used to cool the fuel cell. This improves the heat exchange efficiency of the work machine as a whole.

[0165] (2) The working machine of (1) has a first flow path through which the first heat medium passes to regulate the temperature of the fuel cell, and a second flow path through which the second heat medium passes to regulate the temperature of the electrical components, and the auxiliary heat exchanger is connected to the first flow path and the second flow path. With this configuration, heat exchange between the first heat medium and the second heat medium is performed by the auxiliary heat exchanger.

[0166] (3) The working machine of (2) has a first heat exchanger provided in the first flow path that adjusts the temperature of the first heat medium that has passed through the fuel cell, and a second heat exchanger provided in the second flow path that adjusts the temperature of the second heat medium that has passed through the electrical equipment. With this configuration, the first heat exchanger can lower the temperature of the first heat medium that has passed through the fuel cell, and the second heat exchanger can lower the temperature of the second heat medium that has passed through the electrical equipment.

[0167] (4) In the work machine of (3), the temperature of the first heat medium that has passed through the first heat exchanger is higher than the temperature of the second heat medium that has passed through the second heat exchanger. In this configuration, an auxiliary heat exchanger performs heat exchange between the high-temperature first heat medium and the low-temperature second heat medium. The first heat medium whose temperature has been lowered by the second heat medium is used to cool the fuel cell.

[0168] (5) In the work machine of (4), the first heat exchanger and the second heat exchanger have a difference in capacity with respect to the extent of temperature drop due to heat exchange. For example, if the extent of temperature drop of the first heat medium in the first heat exchanger is smaller than the extent of temperature drop of the second heat medium in the second heat exchanger, the second heat exchanger may have a relatively large capacity margin. In this case, the cooling of the fuel cell by the first heat medium is supplemented by the second heat medium.

[0169] (6) The working machine of any one of (1) to (5) above has a bypass flow path through which the second heat medium flows, the auxiliary heat exchanger being connected in parallel to the flow path through which the second heat medium passes. According to this configuration, a portion of the second heat medium passes through the auxiliary heat exchanger and heat is exchanged between the second heat medium and the first heat medium. Another portion of the second heat medium passes through the bypass flow path without passing through the auxiliary heat exchanger. In other words, the configuration is effective when it is not necessary to exchange heat between all of the second heat medium and the first heat medium in the auxiliary heat exchanger.

[0170] (7) The work machine according to (6) above further includes a bypass valve that adjusts the proportion of the second heat medium flowing through the bypass passage. According to this configuration, the amount of the second heat medium used for heat exchange in the auxiliary heat exchanger is adjusted.

[0171] (8) In the work machine of any one of (1) to (3), the electrical equipment includes a battery that stores the power generated by the fuel cell and a motor that generates running power. When starting operation of the work machine, it is preferable that warm-up operation be performed for the rolling bearings of the battery and motor, which are the electrical equipment. To warm up the battery and motor, an auxiliary heat exchanger utilizes the exhaust heat of the first heat exchanger (first heat medium), making it possible to shorten the time required for warming up the electrical equipment.

[0172] (9) The working machine according to (3) above further includes an air conditioning system having a compressor, an expansion valve, an evaporator, and a condenser, and having a cooling function using a third heat medium, and the evaporator exchanges heat between the first heat medium or the second heat medium and the third heat medium. According to this configuration, the first heat medium or the second heat medium, the temperature of which has been lowered by the third heat medium, is used to cool the fuel cell or the electrical equipment.

[0173] (10) The work machine according to (9) further includes a battery and a heating unit that uses a fourth heat medium to heat the battery, and the condenser exchanges heat between the fourth heat medium and the third heat medium. When the battery temperature is low, the condenser's performance decreases. This configuration allows the fourth heat medium to be heated by exhaust heat from an air conditioner (third heat medium), and the fourth heat medium can be used to efficiently raise the temperature of the battery.

[0174] (11) The work machine according to (9) or (10) further includes a first valve that adjusts the flow rate of the first heat medium or the second heat medium passing through the evaporator. According to this configuration, the opening of the first valve can be feedback-controlled, for example, to adjust the level of assistance by the third heat medium for the air conditioning unit.

[0175] (12) The work machine according to (10) further includes a second valve that adjusts the flow rate of the fourth heat medium passing through the battery. According to this configuration, the opening degree of the second valve can be feedback-controlled, for example, to adjust the level of assistance for raising the temperature of the battery by the third heat medium for the air conditioning device.

[0176] (13) In the work machine according to (10), the heating unit has an electric heater that heats the fourth heat medium. With this configuration, it is possible to quickly raise the temperature of the battery.

[0177] (14) A work machine according to an embodiment of the present disclosure includes a machine frame, a fuel cell mounted on the machine frame, electrical equipment mounted on the machine frame, a heat exchanger for adjusting the temperature of one or both of the fuel cell and the electrical equipment using a heat medium, and an air conditioning device having a compressor, an expansion valve, an evaporator, and a condenser and equipped with a cooling function using a third heat medium, and the evaporator exchanges heat between the heat medium and the third heat medium.

[0178] In a work machine having the above configuration, for example, when the temperature of the heat medium that regulates the temperature of one or both of the fuel cell and the electrical equipment is higher than the temperature of the third heat medium for the air conditioning device, the temperature of the heat medium is lowered by the third heat medium in the auxiliary heat exchanger, and the heat medium whose temperature has been lowered by the third heat medium is used to cool one or both of the fuel cell and the electrical equipment.

[0179] (15) The work machine of (14) has a battery and a heating unit that uses a fourth heat medium to heat the battery, and the condenser exchanges heat between the fourth heat medium and the third heat medium. When the temperature of the battery is low, the condenser's performance decreases. With this configuration, the fourth heat medium is heated by exhaust heat from an air conditioner (third heat medium), and the fourth heat medium can be used to efficiently raise the temperature of the battery. In other words, the fourth heat medium whose temperature has been raised by the third heat medium can be used to heat the battery.

[0180] <Details of Embodiments of the Present Disclosure> Hereinafter, details of embodiments of the present disclosure will be described with reference to the drawings. Note that at least some of the embodiments described below may be combined in any manner.

[0181] [Overall structure of work machine] Figure 25 is a perspective view showing an example of the overall structure of a work machine. The work machine of this embodiment is a work vehicle used for agricultural work, and more specifically, a tractor. The work machine is not limited to tractors, and may be a mobile body such as a construction machine or a utility vehicle. Below, a case will be described in which the work machine is a work vehicle 10. Figure 26 is a right side view of the work vehicle 10 with some of the exterior parts (bonnet 34, cover 111, etc.) removed.

[0182] The work vehicle 10 has a chassis 41, a drive unit 14, a driver's seat 15, a cabin 16, a bonnet 34, a cover 111, a tank unit 21, a first radiator 48, a second radiator 49, and a traveling unit 12. From the front to the rear of the work vehicle 10, the bonnet 34 and the cover 111 are mounted on the chassis 41, and the cabin 16 is disposed behind the cover 111.

[0183] The cabin 16 has front pillars, rear pillars, and a roof, and is a driver's compartment defined by these. The work vehicle 10 may have a canopy or roofing instead of the cabin 16. If the work vehicle 10 does not have a cabin 16, the tank unit 21 is disposed above the driver's seat 15 by the mounting frame 17.

[0184] 26 , a second radiator 49, a fuel cell 24, and a first radiator 48 are mounted in this order from the front to the rear in the front part of the chassis 41. The second radiator 49 and the fuel cell 24 are covered by a hood 43, and the first radiator 48 is covered by a cover 111.

[0185] The tank unit 21 has a tank 13 therein for storing fuel. The fuel may be liquid or gas, such as hydrogen, methane, or carbon monoxide (CO). In this embodiment, the tank 13 stores hydrogen gas. The drive unit 14 is driven by the stored fuel. The work vehicle 10 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 its energy source. The fuel cell 24 may generate electricity using methane or carbon monoxide (CO).

[0186] The drive device 14 has a fuel cell 24, a battery 30, and an electric motor 31 (see FIG. 27). FIG. 27 is a perspective view showing an example of the internal structure of the work vehicle 10. The battery 30 has a battery pack 30A (see FIG. 28) that stores the output power of the fuel cell 24. FIG. 28 is a block diagram showing an example of the functional configuration of the work vehicle 10. The work vehicle 10 has a hydrogen gas pipe 22. Hydrogen gas is supplied from a fill port 52 (see FIG. 28) connected to the end of the pipe 22 and filled into the tank 13. The hydrogen gas in the tank 13 is supplied to the fuel cell 24 through the pipe 22.

[0187] The traveling device 12 is mounted on a chassis 41 and has front wheels 12A and rear wheels 12B. 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).

[0188] [Internal Structure of Work Vehicle] The chassis 41 (see Figure 27) is configured to have a steel frame that is long in the front-to-rear direction, and has a front frame 32 and a gear case 33. The gear case 33 is connected to the rear of the front frame 32. The gear case 33 and the front frame 32 form the skeleton of the work vehicle 10. The chassis 41, which has the front frame 32 and gear case 33, serves as a body frame (machine frame) on which the drive unit 14, driver's seat 15, cabin 16, etc. are mounted.

[0189] A mounting frame 17 for the tank unit 21 is connected to the chassis 41. The mounting frame 17 supports the tank unit 21 above the cabin 16. 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 17B that support the ceiling frame 17A from below, and a pair of left and right reinforcing frames 17C that are connected to the front end of the ceiling frame 17A. The tank unit 21 is connected to the ceiling frame 17A. The reinforcing frames 17C are reinforcing diagonal members that slope downward from the front end of the ceiling frame 17A to the front frame 32.

[0190] A support frame 37 is connected to the chassis 41, and the battery 30 is supported by the support frame 37. 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.

[0191] The gear case 33, located behind 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 gear case 33 includes a branching mechanism that outputs a portion of the power of the motor 31 to a PTO shaft 334 (see FIG. 26 ). The PTO shaft 334 is an output shaft that protrudes from the rear of the gear case 33.

[0192] The work vehicle 10 has a coupling device 43 (see FIG. 26) for coupling a work implement 19 (see FIG. 28) for performing the desired agricultural work to the rear of the work vehicle 10. The work implement 19 is also called an implement. Examples of the work implement 19 include a cultivator and a baler. The rotational motion of the PTO shaft 334 is transmitted to the input shaft of the work implement 19, for example, while the work vehicle 10 is traveling. The work vehicle 10 can drive the work implement 19 with the power of the motor 31 while traveling in a field or the like.

[0193] [Functional Configuration of Work Vehicle] As shown in FIG. 28, the functional systems of the work vehicle 10 include a fuel system FS, a power system PS, and a temperature regulation system TS.

[0194] Components of the fuel system FS include the tank 13 and the valve unit 45. Components of the temperature control system TS include a first radiator 48, a second radiator 49, and an air conditioning device (air conditioner) 80. Components of the power system PS include the fuel cell 24, a boost circuit 28, a DC / DC converter 26, an inverter 27, a battery 30, a motor 31, and a gear case 33. Hereinafter, the DC / DC converter 26 will also be referred to as the "converter 26." In this embodiment, the converter 26 has a first DC / DC converter 26A (also referred to as the "first converter 26A") and a second DC / DC converter 26B (also referred to as the "second converter 26B").

[0195] The tank 13 is connected to the first pipe 22A and the second pipe 22B via the valve unit 45. The first pipe 22A is a gas pipe that connects the fill port 52 and the valve unit 45, and guides the hydrogen gas introduced into the fill port 52 to the tank 13. The second pipe 22B is a gas pipe that connects the fuel cell 24 and the valve unit 45, and guides the hydrogen gas stored in the tank 13 to the fuel cell 24.

[0196] The valve unit 45 is an assembly of valves including an on-off valve and a pressure reducing valve. The valve unit 45 controls the operation of the internal valves to adjust the flow rate of the hydrogen gas in the tank 13 and output it to the fuel cell 24.

[0197] The motor 31 has a rotor and a stator with multiple coils, and drives the output shaft at a predetermined torque and rotational speed. In the present embodiment, only one motor 31 is mounted on the work vehicle 10, and the rotating shaft of the motor 31 is coupled to the gear case 33. The power transmission mechanism of the gear case 33 outputs a portion of the power of the motor 31 to the traveling device 12, and outputs the remainder of the power of the motor 31 to the PTO shaft 334.

[0198] The fuel cell 24 is, for example, a battery module in which a plurality of unit cells, each having a positive electrode and a negative electrode, are stacked side by side in a casing. 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. The fuel cell 24 is electrically connected to a boost circuit 28, which is electrically connected to an inverter 27.

[0199] The boost circuit 28 boosts the voltage input from the fuel cell 24 and outputs it to the inverter 27. The inverter 27 is electrically connected to the motor 31. The inverter 27 converts the direct current input from the boost circuit 23 into three-phase alternating current and outputs it to the motor 31. The power generated by the fuel cell 24 is boosted and converted into alternating current and transmitted to the motor 31.

[0200] The work vehicle 10 has low-voltage 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. Examples of the low-voltage electrical components include the battery 30, the first fan 35 of the first radiator 48, the second fan 36 of the second radiator 49, and the air conditioning device 80. The step-down circuit is a converter 26, which in this embodiment is a first converter 26A and a second converter 26B.

[0201] The first converter 26A steps down the DC voltage input from the boost circuit 28 and supplies it to the battery 30 and the air conditioner 80. The second converter 26B steps down the DC voltage input from the boost circuit 28 and supplies it to the first fan 35 of the first radiator 48 and the second fan 36 of the second radiator 49.

[0202] The inverter 27 and the converter 26 (the first converter 26A and the second converter 26B) are attached to a chassis 41 that serves as a vehicle body frame. The inverter 27 and the converter 26 are mounted near the driver's seat 15.

[0203] The battery 30 is a power storage device that temporarily stores power to be supplied to the motor 31. The battery 30 includes a battery pack 30A. The battery pack 30A includes at least one battery. The battery is, for example, a rechargeable battery such as a lithium-ion battery or a lead-acid battery.

[0204] [Regarding the Temperature Regulation System TS] Fig. 29 is an explanatory diagram showing an example of the temperature regulation system TS. The temperature regulation system TS will be described with reference to Fig. 28 and Fig. 29. The temperature regulation system TS has a first radiator 48, a second radiator 49, and an air conditioner 80.

[0205] The first radiator 48 is a first heat exchanger included in the first cooling unit U1 for cooling the fuel cell 24 with a first heat medium (first coolant) C1. The second radiator 49 is a second heat exchanger included in the second cooling unit U2 for cooling the electrical components E including the motor 31 with a second heat medium (second coolant) C2.

[0206] A first flow path (first pipe) H1 is connected to the first radiator 48. The first flow path H1 is a circulation flow path, and the first heat medium C1 is circulated through the first flow path H1 by the pump 47. The first flow path H1 passes through the first radiator 48. The first radiator 48 exchanges heat between the first heat medium C1 and the outside air to cool the first heat medium C1. The first radiator 48 has a first fan 35 for promoting heat exchange. The object to be cooled by the first cooling unit U1 including the first radiator 48 and the flow path H1 is the fuel cell 24.

[0207] A second flow path (second piping) H2 is connected to the second radiator 49. The second flow path H2 is a circulation flow path, and the second heat medium C2 is circulated through the second flow path H2 by the pump 46. The second flow path H2 passes through the second radiator 49. The second radiator 49 exchanges heat between the second heat medium C2 and the outside air to cool the second heat medium C2. The second radiator 49 has a second fan 36 for promoting heat exchange. The objects to be cooled by the second cooling unit U2 including the second radiator 49 and the flow path H2 are the electrical equipment E, which is a heat-generating item, such as the first converter 26A, the second converter 26B, the battery 30, the motor 31, the inverter 27, and the boost circuit 28.

[0208] As described above, the temperature adjustment system TS has a first flow path H1 through which the first heat medium C1 passes to adjust the temperature of the fuel cell 24, and a second flow path H2 through which the second heat medium C2 passes to adjust the temperature of the electrical equipment E. The first radiator 48 is provided in the first flow path H1 and adjusts (cools) the temperature of the first heat medium C1 that has passed through the fuel cell 24. The second radiator 49 is provided in the second flow path H2 and adjusts (cools) the temperature of the second heat medium C2 that has passed through the electrical equipment E.

[0209] The temperature adjustment system TS further includes an auxiliary radiator as an auxiliary heat exchanger 60. The auxiliary heat exchanger 60 is connected to the first flow path H1 and the second flow path H2. That is, the first flow path H1 and the second flow path H2 pass through the auxiliary heat exchanger 60. The auxiliary heat exchanger 60 exchanges heat between the first heat medium C1 in the first flow path H1 and the second heat medium C2 in the second flow path H2.

[0210] In this embodiment, the flow rate of the first heat medium C1 flowing through the first flow path H1 is greater than the flow rate of the second heat medium C2 flowing through the second flow path H2. The first radiator 48 and the second radiator 49 have different capabilities in terms of the amount of temperature decrease due to heat exchange. In this embodiment, as shown in FIG. 29 , the amount of temperature decrease ΔT1 of the first heat medium C1 in the first radiator 48 is smaller than the amount of temperature decrease ΔT2 of the second heat medium C2 in the second radiator 49.

[0211] The temperature t11 of the first heat medium C1 that has passed through the first radiator 48 is higher than the temperature t21 of the second heat medium C2 that has passed through the second radiator 49. The auxiliary heat exchanger 60 performs heat exchange between the high-temperature first heat medium C1 and the low-temperature second heat medium C2. Note that in Fig. 29, the temperature t13 of the first heat medium C1 after passing through the fuel cell 24 but before passing through the first radiator 48 is illustrated as being the same as the temperature t23 of the second heat medium C2 after passing through all the electrical components E but before passing through the second radiator 49.

[0212] Due to heat exchange between the first heat medium C1 and the second heat medium C2 in the auxiliary heat exchanger 60, the temperature t22 of the second heat medium C2 after passing through the auxiliary heat exchanger 60 becomes higher than the temperature t21 of the second heat medium C2 before passing through the auxiliary heat exchanger 60. In contrast, the temperature t12 of the first heat medium C1 after passing through the auxiliary heat exchanger 60 becomes lower than the temperature t11 of the first heat medium C1 before passing through the auxiliary heat exchanger 60.

[0213] The first heat medium C1, whose temperature has been lowered by the auxiliary heat exchanger 60, passes through the fuel cell 24. The first heat medium C1, whose temperature has been lowered by the second heat medium C2, is used to cool the fuel cell 24. In other words, the cooling of the fuel cell 24 is supplemented by the second heat medium C2.

[0214] The second flow path H2 has a flow path 62 through which the second heat medium C2 passes through the auxiliary heat exchanger 60. A bypass flow path 61 is provided in the second flow path H2. In other words, the temperature adjustment system TS has the bypass flow path 61 that is connected in parallel to the flow path 62 and through which the second heat medium C2 flows. A portion of the second heat medium C2 in the second flow path H2 passes through the auxiliary heat exchanger 60 (flow path 62) and undergoes heat exchange between the second heat medium C2 and the first heat medium C1. Another portion of the second heat medium C2 can circulate through the bypass flow path 61 without passing through the auxiliary heat exchanger 60 (flow path 62).

[0215] The temperature adjustment system TS has a bypass valve 63. In the configuration shown in Fig. 29 , the bypass valve 63 is provided midway along the bypass flow path 61. The opening degree of the bypass valve 63 is adjusted and controlled by a control device 70 (see Fig. 28 ) provided in the work vehicle 10. The bypass valve 63 may be provided at a branch point 64 between the second flow path H2 and the bypass flow path 61. In this case, the bypass valve 63 is a three-way valve.

[0216] The bypass flow path 61 is effective when it is not necessary to exchange heat between all of the second heat medium C2 and the first heat medium C1 in the auxiliary heat exchanger 60. Furthermore, the bypass valve 63 adjusts the amount (flow rate) of the second heat medium C2 used for heat exchange in the auxiliary heat exchanger 60. The bypass valve 63 can be opened fully open, fully closed, or at an intermediate opening. By adjusting the opening degree of the bypass valve 63, the flow rate of the second heat medium C2 flowing through the bypass flow path 61 is adjusted.

[0217] As will be explained later, when starting operation of the work vehicle 10, it is preferable to perform a warm-up operation for the battery 30, which is the electrical equipment E, and the rolling bearings (not shown) of the motor 31. For the warm-up operation, the opening of the bypass valve 63 is reduced, and a relatively large amount of the second heat medium C2 flows through the auxiliary heat exchanger 60 (flow path 62). If warm-up is no longer required, or if the assistance of the first radiator 48 is not required, the opening of the bypass valve 63 is increased, and a relatively large amount of the second heat medium C2 flows through the bypass flow path 61.

[0218] As described above, the bypass flow path 61 distributes the second heat medium C2 to the flow path 62 that passes through the auxiliary heat exchanger 60 and the bypass flow path 61. The proportion of the second heat medium C2 flowing through the bypass flow path 61 is adjusted by adjusting the opening degree of the bypass valve 63. The bypass valve 63 also makes it possible to reduce the amount of second heat medium C2 flowing through the bypass flow path 61 to zero. When the bypass valve 63 is provided at the branching portion 64, it is also possible to reduce the amount of second heat medium C2 flowing through the auxiliary heat exchanger 60 (flow path 62) to zero.

[0219] Although not shown, a valve may be provided in the flow path from the branching portion 64 to the auxiliary heat exchanger 60. By adjusting the opening degree of the valve, the flow rate of the second heat medium C2 flowing through the auxiliary heat exchanger 60 (flow path 62) can be adjusted, and the flow rate can also be set to zero.

[0220] [Modification of Temperature Regulation System TS] Figure 30 is an explanatory diagram showing a modification of the temperature regulation system TS. The temperature regulation system TS shown in Figure 30 has the configuration of the temperature regulation system TS shown in Figure 29, and also has an air conditioner 80 and a heating unit 72. The heating unit 72 is a device that raises the temperature of the battery 30 using the fourth heat medium C4. Note that the configuration of the temperature regulation system TS shown in Figure 29 is omitted in Figure 30.

[0221] The air conditioning device 80 has a compressor 81, an expansion valve 82, an evaporator 83, and a condenser 84, and has a cooling function using a third heat medium C3. The air conditioning device 80, for example, adjusts (cools) the temperature inside the cabin 16 and cools devices (e.g., heat-generating components such as the control device 70) included in the work vehicle 10. The air conditioning device 80 has a circulation pipe 85 through which the third heat medium C3 passes. The compressor 81, the expansion valve 82, the evaporator 83, and the condenser 84 are provided in various parts of the circulation pipe 85. The third heat medium C3 in the evaporator 83 has a lower temperature than one or both of the first heat medium C1 and the second heat medium C2.

[0222] The evaporator 83 performs heat exchange between the third heat medium C3 and the first heat medium C1 or the second heat medium C2. That is, the first flow path H1 through which the first heat medium C1 flows passes through the evaporator 83, and heat exchange between the first heat medium C1 and the third heat medium C3 occurs in the evaporator 83. Alternatively, the second flow path H2 through which the second heat medium C2 flows passes through the evaporator 83, and heat exchange between the second heat medium C2 and the third heat medium C3 occurs in the evaporator 83. Alternatively, both the first flow path H1 and the second flow path H2 may pass through the evaporator 83, and heat exchange between the first heat medium C1 and the third heat medium C3 and heat exchange between the second heat medium C2 and the third heat medium C3 may occur in the evaporator 83.

[0223] In the evaporator 83, the temperature of the first heat medium C1 or the second heat medium C2 is lowered by the third heat medium C3. The lowered temperature first heat medium C1 cools the fuel cell 24, and the lowered temperature second heat medium C2 cools the electrical equipment E. In other words, according to the temperature regulation system TS shown in Fig. 30 , the third heat medium C3 supplements the cooling of the fuel cell 24 or the electrical equipment E.

[0224] The temperature adjustment system TS shown in Fig. 30 has a valve (first valve) 87 provided in the first flow path H1 or the second flow path H2. The valve 87 can arbitrarily change the opening degree of its valve element to adjust the flow rate of the first heat medium C1 or the second heat medium C2 passing through the evaporator 83. The opening degree of the valve 87 is controlled by the control device 70. The opening degree of the valve 87 is feedback-controlled, for example, based on the temperature of the first heat medium C1 or the temperature of the second heat medium C2. This makes it possible to adjust the auxiliary level of the third heat medium C3 for the first radiator 48 side or the second radiator 49 side.

[0225] 30 includes a heating unit 72 that uses the fourth heat medium C4 to heat the battery 30, as described above. The heating unit 72 includes a circulation flow path 88 that circulates the fourth heat medium C4, and a valve (second valve) 89. The heating unit 72 includes an electric heater 90 that heats the fourth heat medium C4. The electric heater 90 enables the battery 30 to be quickly heated.

[0226] The fourth heat medium C4 in the condenser 84 may have a lower temperature than the third heat medium C3. In this case, the condenser 84 exchanges heat between the fourth heat medium C4 and the third heat medium C3. Here, when the temperature of the battery 30 is low, the condenser 84's performance decreases. By exchanging heat between the fourth heat medium C4 and the third heat medium C3 in the condenser 84, it becomes possible to raise the temperature of the fourth heat medium C4 using the exhaust heat of the air conditioning device 80 (the third heat medium C3). It becomes possible to efficiently raise the temperature of the battery 30 by using the fourth heat medium C4.

[0227] The valve 89 is provided midway through the circulation flow path 88. The valve 89 adjusts the flow rate of the fourth heat medium C4 passing through the battery 30. The opening degree of the valve 89 is controlled by the control device 70. The opening degree of the valve 89 is feedback-controlled based on, for example, the temperature of the battery 30. This configuration makes it possible to adjust the level of assistance provided by the third heat medium C3 to the heating unit 72.

[0228] Work vehicle 10 of this embodiment As described above, the work vehicle 10 of this embodiment (see FIG. 29 ) has the fuel cell 24, electrical components E such as the motor 31, and the auxiliary heat exchanger 60. The auxiliary heat exchanger 60 exchanges heat between the first heat medium C1 that regulates (cools) the temperature of the fuel cell 24 and the second heat medium C2 that regulates (cools) the temperature of the electrical components E. In this embodiment, the temperature t11 of the first heat medium C1 that passes through the first radiator 48 after cooling the fuel cell 24 is higher than the temperature t21 of the second heat medium C2 that passes through the second radiator 49 after cooling the electrical components E (t11>t21).

[0229] The auxiliary heat exchanger 60 performs heat exchange between the first heat medium C1 and the second heat medium C2. That is, the high-temperature first heat medium C1 is cooled by the low-temperature second heat medium C2. The first heat medium C1 cooled in this manner cools the fuel cell 24. That is, the cooling of the fuel cell 24 is supplemented by the second heat medium C2. As a result, the heat exchange efficiency of the work vehicle 10 as a whole is improved. In particular, there is a possibility of reducing the size of the first radiator 48.

[0230] In the case of the work vehicle 10 of this embodiment, the electrical equipment E includes a battery 30 that stores the power generated by the fuel cell 24, and a motor 31 that generates driving power. When starting to operate the work vehicle 10, it is preferable to perform warm-up operation for the rolling bearings (not shown) of the battery 30 and motor 31, which are the electrical equipment E. To warm up the battery 30 and motor 31, the auxiliary heat exchanger 60 utilizes the exhaust heat of the first radiator 48 (first heat medium C1), making it possible to shorten the time required for warm-up operation of the electrical equipment E.

[0231] [Work vehicle 10 having a different temperature control system TS] Figure 31 is an explanatory diagram of a temperature control system TS of a work vehicle 10 different from the configuration shown in Figures 29 and 30. The work vehicle 10 having the configuration shown in Figure 31 is the same as the work vehicle 10 shown in Figure 25 except for the temperature control system TS. In other words, the work vehicle 10 has a chassis 41 which is a machine frame, a fuel cell 24 mounted on the chassis 41, and electrical equipment E mounted on the chassis 41.

[0232] The temperature adjustment system TS shown in Fig. 31 has a radiator 91 as a heat exchanger. The radiator 91 uses a heat medium C5 to adjust the temperature of one or both of the fuel cell 24 and the electrical equipment E. In the configuration shown in Fig. 31, the temperature adjustment system TS has a circulation flow path 92 that passes through the radiator 91, and the heat medium C5 that flows through the circulation flow path 92 passes through both the fuel cell 24 and the electrical equipment E and is used to adjust (cool) the temperatures of the fuel cell 24 and the electrical equipment E.

[0233] The temperature adjustment system TS shown in Fig. 31 includes an air conditioner 80 and a heating unit 72 that uses a fourth heat medium C4 to raise the temperature of the battery 30. The air conditioner 80 includes a compressor 81, an expansion valve 82, an evaporator 83, and a condenser 84, and has a cooling function that uses the third heat medium C3. The heating unit 72 raises the temperature of the battery 30 using the fourth heat medium C4. The air conditioner 80 and the heating unit 72 are the same as the air conditioner 80 and the heating unit 72 shown in Fig. 30.

[0234] The circulation flow path 92 has a bypass flow path 95. A valve 87 is provided in the bypass flow path 95. The valve 87 has a valve element whose opening degree can be changed as desired to adjust the flow rate of the heat medium C5 passing through the evaporator 83. The function of the valve 87 is the same as that of the valve 87 of the temperature adjustment system TS shown in FIG. 30. The heating unit 72 has an electric heater 90 that heats the fourth heat medium C4. The electric heater 90 makes it possible to quickly raise the temperature of the battery 30.

[0235] When the temperature of the heat medium C5 is higher than that of the third heat medium C3 for the air conditioning device 80, the evaporator 83 exchanges heat between the heat medium C5 flowing through the bypass flow path 95 and the third heat medium C3. The temperature of the heat medium C5 is lowered by the third heat medium C3. The heat medium C5, whose temperature has been lowered by the third heat medium C3, is used to cool the fuel cell 24 and the electrical equipment E. In other words, the third heat medium C3 supplements the cooling of the fuel cell 24 and the electrical equipment E.

[0236] The condenser 84 exchanges heat between the fourth heat medium C4 and the third heat medium C3. When the temperature of the battery 30 is low, the condenser's performance decreases. By exchanging heat between the fourth heat medium C4 and the third heat medium C3 in the condenser 84, the temperature of the fourth heat medium C4 is increased by the exhaust heat of the air conditioning device 80 (the third heat medium C3). The fourth heat medium C4 can be used to efficiently increase the temperature of the battery 30.

[0237] [Others] The above-described embodiments are illustrative in all respects and are not limiting. The scope of the present invention is defined by the claims, not by the above-described embodiments, and includes all modifications within the scope equivalent to the structures described in the claims. The symbols used in Chapter 3 are used only in this Chapter and are unrelated to the symbols in other chapters. The structures disclosed in Chapter 3 are applicable to the inventions disclosed in Chapter 1 or Chapter 2, and vice versa.

[0238] [Explanation of symbols] 10 Work vehicle (work machine) 24 Fuel cell 30 Battery 31 Motor 41 Chassis (machine frame) 48 First radiator (first heat exchanger) 49 Second radiator (first heat exchanger) 60 Auxiliary heat exchanger 61 Bypass flow path 62 Flow path 63 Bypass valve 72 Heating unit 80 Air conditioning device 81 Compressor 82 Expansion valve 83 Evaporator 84 Condenser 87 Valve (first valve) 89 Valve (second valve) 90 Electric heater 91 Radiator (heat exchanger) C1 First heat medium C2 Second heat medium C3 Third heat medium C4 Fourth heat medium C5 Heat medium E Electrical equipment H1 First flow path H2 Second flow path

Claims

1. A work machine having a vehicle body, a fuel cell mounted on the vehicle body, a battery for storing electric power generated by the fuel cell, a motor operating using electric power as energy, a first power converter, and a second power converter, wherein the vehicle body has a vehicle body frame and a support structure for attaching the first power converter and the second power converter to the vehicle body frame, and the support structure has: a base portion attached to the vehicle body frame; a first support portion having a first upright portion rising from the base portion and to which the first power converter is attached and supported; a second support portion having a second upright portion rising from the base portion and to which the second power converter is attached and supported.

2. The work machine according to claim 1, wherein the first power converter is formed in a box shape, and the first upright portion faces one surface of the first power converter formed in the box shape and has a first attachment surface to which the one surface side is attached.

3. The work machine according to claim 2, wherein the second power converter is formed in a box shape, and the second upright portion faces one surface of the second power converter formed in the box shape and has a second attachment surface to which the one surface side is attached.

4. The work machine according to claim 3, wherein the first attachment surface and the second attachment surface are arranged to be spaced apart in the width direction of the vehicle body.

5. The work machine according to claim 4, wherein the first power converter is arranged between the first attachment surface and the second attachment surface.

6. The work machine according to any one of claims 1 to 5, wherein the first support portion and the second support portion are each constituted by a separate member and can be individually attached to the base portion.

7. The work machine according to any one of claims 1 to 5, wherein the first support portion, the second support portion, and a part of the base portion are constituted by one member.

8. The work machine according to any one of claims 1 to 7, wherein the support structure has a cover that covers a support unit including the first support portion and the second support portion from the side of the vehicle.

9. The work machine according to claim 8, wherein the first support portion and the second support portion are arranged side by side in the vehicle width direction, and the cover covers the support unit from the outside in the vehicle width direction.

10. Each of the first power converter and the second power converter is connected to a harness, and the cover covers a connection portion between the first power converter and the harness and a connection portion between the second power converter and the harness. The working machine according to claim 8 or claim 9.

11. The vehicle body has a cabin, and the first support portion and the second support portion are located below the cabin. The working machine according to any one of claims 1 to 10.

12. The vehicle body has rear wheels on both sides in the vehicle width direction of the vehicle body frame, and the first support portion and the second support portion are located between one of the pair of rear wheels and the vehicle body frame. The working machine according to claim 11.

13. The support structure has a first bolt that fixes the first support portion to the base portion, a second bolt that fixes the second support portion to the base portion, and a third bolt that connects the first support portion and the second support portion. The working machine according to claim 6.

14. The first power converter is located closer to the inner side in the vehicle width direction than the second power converter. The second support portion has a second inner frame located on the inner side in the vehicle width direction of the second power converter as the second upright portion, and the outer side in the vehicle width direction of the second support portion is open. The support structure has a cover that covers the second power converter supported by the second support portion from the outer side in the vehicle width direction. The working machine according to any one of claims 1 to 13.

15. The first support portion has a first inner frame located on the inner side in the vehicle width direction of the first power converter as the first upright portion, and the outer side in the vehicle width direction is open. The working machine according to claim 14.

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