Fuel cell unit and working machine

Abstract

A fuel cell unit support mechanism (FS) is coupled to a rotating frame (20). A fuel cell stack (22) is attached to the fuel cell unit support mechanism (FS). A hydrogen tank support mechanism (TF) is attached to the fuel cell unit support mechanism (FS). A hydrogen tank (21) supplies hydrogen to the fuel cell stack (22). The hydrogen tank (21) is attached to the hydrogen tank support mechanism (TF).

Description

TECHNICAL AREA The present disclosure relates to a fuel cell unit and a working machine. STATE OF THE ART The development of new energy sources that do not emit greenhouse gases such as carbon dioxide in machinery and similar equipment has been pursued in the prior art. Fuel cells have attracted attention as one such energy source. A fuel cell generates electrical energy through the chemical reaction of hydrogen and oxygen in a fuel cell stack. After electricity generation, the fuel cell releases only water; no carbon dioxide is emitted. A machine equipped with such a fuel cell is described, for example, in WO 2022 / 137688 (Patent Document 1). List of objections Patent literature Patent document 1: WO 2022 / 137688 BRIEF SUMMARY OF THE INVENTION Technical problem In a construction machine like a hydraulic excavator, the shocks and vibrations experienced by the vehicle body are significant compared to a passenger car. Therefore, the displacement of a hydrogen system component, such as a fuel cell, hydrogen tank, or hydrogen line, during an impact is substantial. If the relative displacement between hydrogen system components becomes large, damage occurs in the hydrogen line and any connecting sections, and its lifespan is reduced. One object of the present disclosure is to provide a fuel cell unit and a working machine with good durability. Solution to the problem A fuel cell unit of the present disclosure is a fuel cell unit attached to a vehicle chassis of a working machine and includes a fuel cell unit support mechanism, a fuel cell, a first hydrogen tank support mechanism, and a first hydrogen tank group. The fuel cell unit support mechanism is coupled to the vehicle chassis. The fuel cell is attached to the fuel cell unit support mechanism. The first hydrogen tank support mechanism is attached to the fuel cell unit support mechanism. The first hydrogen tank group is attached to the first hydrogen tank support mechanism and includes one or more hydrogen tanks that supply hydrogen to the fuel cell. Advantageous effects of the invention According to the present disclosure, a fuel cell unit and a working machine with good durability can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side view illustrating the structure of a working machine incorporating a fuel cell in one embodiment of the present disclosure. Fig. 2 is a side view illustrating a first arrangement of fuel cell stacks and hydrogen tanks in the working machine illustrated in Fig. 1. Fig. 3 is a rear view illustrating the first arrangement of the fuel cell stacks and hydrogen tanks in the working machine illustrated in Fig. 1. Fig. 4 is a side view illustrating a second arrangement of the fuel cell stacks and hydrogen tanks. Fig. 5 is a side view illustrating the second arrangement of the fuel cell stacks and hydrogen tanks. Fig. 6 is a side view illustrating a third arrangement of the fuel cell stacks and hydrogen tanks.Figure 7 is a rear view illustrating the third arrangement example of the fuel cell stacks and hydrogen tanks. Figure 8 is a side view illustrating a fourth arrangement example of the fuel cell stacks and hydrogen tanks. Figure 9 is a rear view illustrating the fourth arrangement example of the fuel cell stacks and hydrogen tanks. Figure 10 is a side view illustrating a fifth arrangement example of the fuel cell stacks and hydrogen tanks in a case where two hydrogen tank support mechanisms are provided. Figure 11 is a side view illustrating a sixth arrangement example of the fuel cell stacks and hydrogen tanks in a case where two hydrogen tank support mechanisms are provided.Figure 12 is a side view illustrating a seventh arrangement example of the fuel cell stacks and hydrogen tanks in a case where two hydrogen tank support mechanisms are provided. DESCRIPTION OF EXECUTION FORMS Embodiments of the present disclosure are described below with reference to the drawings. In the description and drawings, identical or corresponding components are designated with the same reference numerals, and their explanations are not repeated. Furthermore, structures are either not provided in the drawings or, in some cases, simplified for the purpose of simplifying the description. In the following description, “top”, “bottom”, “front”, “back”, “left” and “right” are directions with respect to an operator seated in a driver’s seat 14S in a cabin 14 illustrated in Fig. 1. Therefore, in the following description, a forward-backward direction X represents a direction in which, in a plan view, a boom 16 extends between a base end section and an upper end section. A left-right direction Y represents a direction that, in a plan view, is perpendicular to the forward-backward direction X. An up-downward direction Z represents a direction that is perpendicular to a plane that includes the forward-backward direction and the left-right direction Y, which are perpendicular to each other. A forward direction represents a direction from the base end section of the boom 16 to the upper end section. A backward direction represents a direction from the upper end section of the boom 16 to the base end section. A right side and a left side, as viewed from back to front, are a right direction and a left direction, respectively. A side on which the ground is located in the upward-downward direction Z is downward, and a side on which the sky is located is upward. "In a top view" refers to a perspective in which a machine 100 is viewed from top to bottom. "In a side view" refers to a perspective in which a rotating body 13 is viewed in the left-right direction Y. "In a rear view" refers to a perspective in which the rotating body 13 is viewed from back to front. Structure of the working machine A working machine of the present disclosure is described below with reference to Fig. 1, using an excavator incorporating a fuel cell as an example. It should be noted that the working machine of the present disclosure is not limited to an excavator and may be a bulldozer, a wheel loader, a motor grader or the like, which includes a fuel cell. Fig. 1 is a side view schematically illustrating the structure of a working machine in one embodiment of the present disclosure. As illustrated in Fig. 1, the working machine 100 of the present embodiment is, for example, an excavator that includes a fuel cell unit (FCU). A fuel cell enclosed in the fuel cell unit (FCU) generates electrical energy by chemically reacting hydrogen and oxygen. The working machine 100 includes a fuel cell stack 22 as the fuel cell. Within the fuel cell stack 22, a plurality of fuel cells are connected in series and stacked. The working machine 100 includes, for example, two fuel cell stacks 22, but the number of fuel cell stacks 22 with which the working machine 100 is equipped is not limited to two and can be one, three, or more. The working machine 100 includes a hydrogen tank 21 for supplying hydrogen to the fuel cell stack 22. The working machine 100 includes, for example, four hydrogen tanks 21, but the number of hydrogen tanks 21 with which the working machine 100 is equipped is not limited to four and can be one, two, three, five, or more. The working machine 100 includes a main body 11 and a working device 12, which operates with hydraulic pressure. The main body 11 includes the rotating body 13 and a travel body 15. The chassis 15 includes a pair of left and right endless tracks 15Cr and a drive motor 15M. The work machine 100 can move by rotating the endless tracks 15Cr. The drive motor 15M serves as a drive source for the chassis 15. The rotating body 13 is positioned above the transport body 15 and supported by the transport body 15. A rotary motor (not illustrated) enables the rotating body 13 to rotate relative to the transport body 15, with a rotation axis RX forming its center. The rotation axis RX is an imaginary straight line that serves as the center of rotation of the rotating body 13. The rotary motor can be driven hydraulically or electrically. The rotating body 13 encloses a cabin 14. The operator's seat 14S, on which the operator sits, is provided in the cabin 14. The operator sits on the operator's seat 14S and can manipulate the working device 12, manipulate the rotation of the rotating body 13 relative to the travel body 15, and manipulate the movement of the working machine 100 by the travel body 15. The working device 12 is supported by the rotating body 13. The working device 12 includes a boom 16, an arm 17, and a bucket 18. The working device 12 further includes a boom cylinder 19a, an arm cylinder 19b, and a bucket cylinder 19c. The boom 16 is rotatably connected to the main body 11. In particular, the base end section of the boom 16 is rotatably connected to the rotating body 13 by a boom foot bolt BF as a pivot point. The arm 17 is rotatably connected to the boom 16. In particular, a base end section of the arm 17 is rotatably connected to the upper end section of the boom 16 by an upper boom bolt BT as a pivot point. The bucket 18 is rotatably connected to the arm 17. In particular, a base end section of the bucket 18 is rotatably connected to an upper end section of the arm 17 by an upper arm bolt AT as a pivot point. The rotating body 13 encloses an outer casing OP, which surrounds a machine room. The hydrogen tank 21, the fuel cell stack 22, a storage battery 27, a cooling unit CU (Fig. 3), and the like are arranged in the machine room of the rotating body 13. The outer casing OP covers the circumference of the hydrogen tank 21, the fuel cell stack 22, the storage battery 27, the cooling unit CU, and the like. It should be noted that, although the structure in which the operator seat 14S is arranged in the cabin 14 has been described above, the cabin 14 may be omitted and the operator seat 14S may be exposed to the outside. Furthermore, the work machine 100 need not enclose the cabin 14 and can be operated automatically in an unattended manner. The work machine 100 also need not enclose the cabin 14 and can be remotely controlled by a remote control. Arrangement of fuel cell stacks and hydrogen tanks First example of an arrangement Next, a first arrangement example of the fuel cell stacks 22 and the hydrogen tanks 21 in the working machine 100, which is illustrated in Fig. 1, is described with reference to Fig. 2 and Fig. 3. Figures 2 and 3 are a side view and a rear view, respectively, illustrating the first arrangement example of the fuel cell stack and hydrogen tanks in the machine shown in Figure 1. As illustrated in Figure 2, the fuel cell unit (FCU) includes a hydrogen tank group 21A, the fuel cell stack 22, a fuel cell unit support mechanism FS, a hydrogen tank support mechanism TF, and a damping mechanism DM. The fuel cell unit (FCU) is attached to a rotating frame (vehicle body frame) 20 of the machine 100. The fuel cell unit support mechanism FS is coupled to the rotating frame 20, with the damping mechanism DM or the like arranged between them. The damping mechanism DM supports the fuel cell unit support mechanism FS relative to the rotating frame 20. The damping mechanism DM serves to dampen vibrations. The damping mechanism DM can be, for example, a fluid-sealed bearing or a rubber component. The fluid-sealed bearing, as the damping mechanism DM, is designed to achieve a high damping force through a pressure drop when an enclosed viscous fluid is compressed, for example, by passing through a narrow gap. The viscous fluid used in the fluid-sealed bearing is, for example, silicone oil. The fuel cell unit support mechanism FS includes a lower plate (bearing section) UP, an upper plate (ceiling section) TP, and a column element (side frame section) CM. The lower plate UP is coupled to the rotating frame 20, with the damping mechanism DM and the like arranged between them. It should be noted that the ceiling section TP is located on an upper side of the fuel cell (fuel cell stack 22), protects an upper section of the fuel cell, and is designed to accommodate another component. The bearing section UP is located on a lower side of the fuel cell, protects a lower section of the fuel cell, and is designed to accommodate another component. Each of the ceiling section TP and the bearing section UP is not limited to a single plate and can form a frame. The fuel cell stack 22 is arranged above the rotating frame 20. For example, each of the two fuel cell stacks 22 is attached to the fuel cell unit support mechanism FS by means of, for example, bolting, welding, or the like. Thus, each of the two fuel cell stacks 22 is fixed in such a way that it is not movable relative to the fuel cell unit support mechanism FS. Therefore, each of the two fuel cell stacks 22 and the fuel cell unit support mechanism FS form an identical vibration system in which the vibration patterns relative to the rotating frame 20 are identical to each other. In particular, for example, each of the two fuel cell stacks 22 is arranged above the lower plate UP of the fuel cell unit support mechanism FS. Each of the two fuel cell stacks 22 is attached to the lower plate UP, thereby forming an identical vibration system together with the lower plate UP. The two fuel cell stacks 22 are arranged side by side in the front-back direction X and extend in the left-right direction Y (Fig. 3), so that they are essentially parallel to each other. The upper plate TP is arranged above the fuel cell stack 22 to protect an upper section of the fuel cell stack 22. The upper plate TP is supported by the lower plate UP, with the column element CM, which extends in the up-down direction Z, positioned between them. The column element CM connects the lower plate UP and the upper plate TP. The lower plate UP and the column element CM are fastened to each other by bolting, welding, or similar means. Furthermore, the column element CM and the upper plate TP are fastened to each other by bolting, welding, or similar means. Thus, the lower plate UP, the column element CM, and the upper plate TP are fixed in such a way that they are not movable relative to each other. The lower plate UP, the column element CM, and the upper plate TP form an identical vibration system in which the vibration patterns relative to the rotating frame 20 are identical. The hydrogen tank support mechanism TF is attached to the fuel cell unit support mechanism FS by means of, for example, bolting, welding, or similar methods. Specifically, the hydrogen tank support mechanism TF is located above the upper plate TP of the fuel cell unit support mechanism FS and is attached to the upper plate TP. Thus, the hydrogen tank support mechanism TF is fixed in such a way that it is not movable relative to the fuel cell unit support mechanism FS. Therefore, the hydrogen tank support mechanism TF and the fuel cell unit support mechanism FS form an identical vibration system in which the vibration patterns relative to the rotating frame 20 are identical. The hydrogen tank assembly 21A is arranged above the fuel cell stack 22. The hydrogen tank assembly 21A is attached to the hydrogen tank support mechanism TF, for example, by a strap. Thus, the hydrogen tank assembly 21A is fixed in such a way that it is not movable relative to the hydrogen tank support mechanism TF. Furthermore, the hydrogen tank support mechanism TF is fixed in such a way that it is not movable relative to the fuel cell unit support mechanism FS, as described above. Therefore, the hydrogen tank assembly 21A is fixed in such a way that it is not movable relative to the fuel cell unit support mechanism FS, with the hydrogen tank support mechanism TF positioned between them. As described above, both the hydrogen tank group 21A and the two fuel cell stacks 22 are fixed in such a way that they are not movable relative to the fuel cell unit support mechanism FS and form an identical vibration system in which vibration patterns relative to the rotating frame 20 are identical to each other. The hydrogen tank group 21A includes one or more hydrogen tanks 21. The hydrogen tank group 21A can consist of one hydrogen tank 21 or can consist of a plurality of hydrogen tanks 21. For example, the hydrogen tank group 21A consists of four hydrogen tanks 21 attached to the hydrogen tank support mechanism TF. In a side view, the four hydrogen tanks 21 are arranged in two rows of two columns each. That is, the four hydrogen tanks 21 are arranged such that, in a side view, two hydrogen tanks 21 are oriented in the front-back direction X and two hydrogen tanks 21 are oriented in the up-down direction Z. The respective group of four hydrogen tanks 21 extends in the left-right direction Y such that they are essentially parallel to each other. A pressure reducer 23 is attached to the hydrogen tank support mechanism TF. The pressure reducer 23 reduces the pressure of a high-pressure hydrogen gas supplied from the hydrogen tank 21 to a level at which the high-pressure hydrogen gas can be used in the fuel cell stack 22, which is a power generation device, and includes a pressure reducing valve. The pressure reducer 23 is, for example, located on the front side of an assembly area AR of the four hydrogen tanks 21. The arrangement position of the pressure reducer 23 is not limited to the front side of the assembly area AR and can be a rear or a lateral side of the assembly area AR. The hydrogen tank 21 and the pressure reducer 23 are connected by a tank hose TH (Fig. 3). The high-pressure hydrogen gas in the hydrogen tank 21 is supplied to the pressure reducer 23 via the tank hose TH. An on / off valve 24 is arranged between the hydrogen tank 21 and the tank hose TH. The opening / closing action of the on / off valve 24 controls the starting and stopping of the supply of the high-pressure hydrogen gas from the hydrogen tank 21 to the pressure reducer 23. The pressure reducer 23 and the fuel cell stack 22 are connected by a stacking hose SH. The hydrogen gas, pressure-reduced by the pressure reducer 23, is supplied to the fuel cell stack 22 via the stacking hose SH. A connecting section P1 between the fuel cell stack 22 and the stack hose SH, a connecting section P2 between the hydrogen tank 21 and the tank hose TH, a connecting section P3 between the stack hose and the pressure reducer 23, and a connecting section P3 between the tank hose TH and the pressure reducer 23 are locations where hydrogen gas is likely to escape. These connecting sections P1, P2, and P3 are arranged on sides identical in the left-right direction Y. For example, connecting section P1 is located at a left end of the fuel cell stack 22, connecting section P2 is located at a left end of the hydrogen tank 21, and connecting section P3 is located at a left end of the pressure reducer 23.It should be noted that the connecting section P1 can be located at a right end of the fuel cell stack 22, the connecting section P2 can be located at a right end of the hydrogen tank 21, and the connecting section P3 can be located at a right end of the pressure reducer 23. As illustrated in Fig. 3, the working machine 100 includes the cooling unit CU. The cooling unit CU includes a radiator 25 and an electric fan (cooling fan) 26. The cooler 25 is a device for radiating heat from a cooling medium (coolant, for example, water) that cools the fuel cell stack 22. The cooler 25 is, for example, a heat exchanger. The cooler 25 is, for example, arranged on a lateral side of the fuel cell stack 22, for example, on a left side of the fuel cell stack 22. It should be noted that the cooler 25 can, for example, be arranged on a right side of the fuel cell stack 22, or on a front or a back side of the fuel cell stack 22. The electric fan 26 operates to dissipate heat radiated by the cooler 25 by directing airflow towards the cooler 25. The electric fan 26 is, for example, positioned between the cooler 25 and the fuel cell stack 22. For example, each of the four hydrogen tanks 21 is arranged such that one longitudinal direction of the hydrogen tank 21 is aligned with the left-right direction Y of the working machine 100. Each of the two hydrogen tanks 21 arranged in the front-back direction X is arranged such that the longitudinal direction of the hydrogen tank 21 lies in a plane that includes the left-right direction Y and the front-back direction X of the working machine 100. Each of the two hydrogen tanks 21 arranged in the up-down direction Z is arranged such that the longitudinal direction of the hydrogen tank 21 lies in a plane that includes the left-right direction Y and the up-down direction Z of the working machine 100. The respective inlet / outlet valves 24 of the four hydrogen tanks 21 are arranged on identical sides along the length of the hydrogen tanks 21. For example, the respective inlet / outlet valves 24 of the four hydrogen tanks 21 are arranged on the left side along the length of the hydrogen tanks 21. The inlet / outlet valve 24 of each of the four hydrogen tanks 21 is located at an end section on one side closer to the cooling unit CU, and is arranged along the length of both end sections of the hydrogen tank 21. The first arrangement example 1 has the structure described above. Second arrangement example Figures 4 and 5 are a side view and a rear view, respectively, illustrating a second arrangement example of the fuel cell stacks and the hydrogen tanks. As illustrated in Figure 4, the second arrangement example differs from the first in the mounting position of the hydrogen tank support mechanism TF, the arrangement of the hydrogen tanks 21, the structure of the fuel cell unit support mechanism FS, the arrangement of the fuel cell stacks 22, and the like. In the second arrangement example, the hydrogen tank support mechanism TF is attached to the lower plate UP of the fuel cell unit support mechanism FS. For example, four hydrogen tanks 21 are attached to the hydrogen tank support mechanism TF as the hydrogen tank group 21A. The four hydrogen tanks 21 are, for example, arranged in a single vertical row so that they are aligned in the up-down direction Z. The four hydrogen tanks 21 are, for example, arranged on a rear side of the fuel cell stack 22. The fuel cell unit support mechanism FS includes the lower plate UP, a middle plate CP, the upper plate TP, and the column element CM. The lower plate UP is coupled to the rotating frame 20, with the damping mechanism DM and the like arranged between them. The middle plate CP is located above the lower plate UP. The upper plate TP is located above the middle plate CP. The column element CM is attached to each of the lower plate UP and the middle plate CP by means of, for example, bolting, welding, or the like. Thus, the lower plate UP, the middle plate CP, and the upper plate TP are fixed so that they are not movable relative to each other. For example, two fuel cell stacks 22 are stacked in the up-down direction Z. The fuel cell stack 22 on one lower side is attached to the lower plate UP, and the fuel cell stack 22 on one upper side is attached to the middle plate CP. The middle plate CP protects an upper section of the fuel cell stack 22 on the lower side and protects a lower section of the fuel cell stack 22 on the upper side. The middle plate CP is not limited to a single plate and can form a frame. The four hydrogen tanks 21 and the two fuel cell stacks 22 are fixed in such a way that they are not movable relative to the fuel cell unit support mechanism FS and form an identical vibration system in which vibration patterns relative to the rotating frame 20 are identical to each other. As illustrated in Fig. 5, the four hydrogen tanks 21 extend in the left-right direction Y such that they are essentially parallel to each other. Each of the four hydrogen tanks 21 is arranged such that its longitudinal direction is aligned with the left-right direction Y of the working machine 100. Each of the four hydrogen tanks 21 is arranged such that its longitudinal direction lies in the plane that includes the left-right direction Y and the up-down direction Z of the working machine 100. The respective inlet / outlet valves 24 of the four hydrogen tanks 21 are arranged on identical sides along the length of the hydrogen tanks 21. For example, the respective inlet / outlet valves 24 of the four hydrogen tanks 21 are arranged on a left side along the length of the hydrogen tanks 21. It should be noted that, since the structure of the second arrangement example is essentially the same as the structure of the first arrangement example, apart from the above, the same components or corresponding components in the second arrangement example are given the same reference numerals as those in the first arrangement example, and their description is not repeated. Third example of an arrangement Figures 6 and 7 are a side view and a rear view, respectively, illustrating a third arrangement example of the fuel cell stacks and the hydrogen tanks. As illustrated in Figure 6, the third arrangement example differs from the second arrangement example in the arrangement of the hydrogen tanks 21. In the third arrangement example, four hydrogen tanks 21 are arranged as the hydrogen tank group 21A in a side view in two rows of two columns each. That is, the four hydrogen tanks 21 are arranged such that in a side view two hydrogen tanks 21 are arranged in the front-back direction X and two hydrogen tanks 21 are arranged in the up-down direction Z. As illustrated in Fig. 7, the four hydrogen tanks 21 extend in the left-right direction Y such that they are substantially parallel to each other. Each of the four hydrogen tanks 21 is arranged such that its longitudinal direction is aligned with the left-right direction Y of the working machine 100. Each of the two hydrogen tanks 21 arranged in the front-back direction X is arranged such that its longitudinal direction lies in a plane that includes both the left-right direction Y and the front-back direction X of the working machine 100. Each of the two hydrogen tanks 21 arranged in the up-down direction Z is arranged such that its longitudinal direction lies in a plane that includes both the left-right direction Y and the up-down direction Z of the working machine 100. The respective inlet / outlet valves 24 of the four hydrogen tanks 21 are arranged on identical sides along the length of the hydrogen tanks 21. For example, the respective inlet / outlet valves 24 of the four hydrogen tanks 21 are arranged on a left side along the length of the hydrogen tanks 21. It should be noted that, since the structure of the third arrangement example is essentially the same as the structure of the second arrangement example, apart from the above, the same components or corresponding components in the third arrangement example are given the same reference numerals as those in the second arrangement example, and their description is not repeated. Fourth arrangement example Figures 8 and 9 are a side view and a rear view, respectively, illustrating a fourth arrangement example of the fuel cell stacks and hydrogen tanks. As illustrated in Figure 8, the fourth arrangement example differs from the second arrangement example in the arrangement of the hydrogen tanks 21. In the fourth arrangement example, each of the four hydrogen tanks 21 is arranged as the hydrogen tank group 21A such that the longitudinal direction of the hydrogen tank 21 is aligned with the up-down direction Z. As illustrated in Fig. 9, the four hydrogen tanks 21 are arranged side by side in the left-right direction Y such that they form a single horizontal row in a rear view. Each of the four hydrogen tanks 21 is arranged such that the longitudinal direction of the four hydrogen tanks 21 lies in the plane that includes the left-right direction Y and the up-down direction Z of the working machine 100. The respective inlet / outlet valves 24 of the four hydrogen tanks 21 are arranged on identical sides along the longitudinal direction of the hydrogen tanks 21. For example, the inlet / outlet valve 24 of each of the four hydrogen tanks 21 is arranged on an upper side along the longitudinal direction of the hydrogen tanks 21. It should be noted that, since the structure of the fourth arrangement example is essentially the same as the structure of the second arrangement example, apart from the above, the same components or corresponding components in the fourth arrangement example are given the same reference numerals as those in the second arrangement example, and their description is not repeated. In the preceding first to fourth arrangement examples, the structure described includes one hydrogen tank support mechanism (TF), but the FCU can include a variety of hydrogen tank support mechanisms (TF). A structure in which the FCU includes, for example, two hydrogen tank support mechanisms (TF) is described below as the fifth to seventh arrangement examples. Fifth arrangement example Fig. 10 is a side view illustrating a fifth arrangement example of the fuel cell stacks and hydrogen tanks in a case where two hydrogen tank support mechanisms are provided. As illustrated in Fig. 10, the fuel cell unit (FCU) includes a first hydrogen tank support mechanism (TF1) and a second hydrogen tank support mechanism (TF2). For example, four hydrogen tanks 21 are attached to the first hydrogen tank support mechanism TF1 as the first hydrogen tank group 21A. In a side view, the four hydrogen tanks 21, as the first hydrogen tank group 21A, are arranged in two rows of two columns each. That is, the four hydrogen tanks 21 are arranged such that, in a side view, two hydrogen tanks 21 are arranged in the front-back direction X and two hydrogen tanks 21 are arranged in the up-down direction Z. The respective four hydrogen tanks 21 extend in the left-right direction Y such that they are essentially parallel to each other. For example, four hydrogen tanks 21 are attached to the second hydrogen tank support mechanism TF2 as a second hydrogen tank group 21B. In a side view, the four hydrogen tanks 21, as the second hydrogen tank group 21B, are arranged in two rows of two columns each. That is, the four hydrogen tanks 21 are arranged such that, in a side view, two hydrogen tanks 21 are arranged in the front-back direction X and two hydrogen tanks 21 are arranged in the up-down direction Z. The respective four hydrogen tanks 21 extend in the left-right direction Y such that they are essentially parallel to each other. Each of the first hydrogen tank support mechanism TF1 and the second hydrogen tank support mechanism TF2 is attached to the upper plate TP of the fuel cell unit support mechanism FS. Thus, the fuel cell stack 22, the first hydrogen tank group 21A, and the second hydrogen tank group 21B are fixed in such a way that they are not movable relative to the fuel cell unit support mechanism FS and form an identical vibration system in which vibration patterns relative to the rotating frame 20 are identical to each other. Sixth arrangement example Fig. 11 is a side view illustrating a sixth arrangement example of the fuel cell stacks and hydrogen tanks in a case where two hydrogen tank support mechanisms are provided. As illustrated in Fig. 11, the sixth arrangement example differs from the fifth arrangement example in that the second hydrogen tank support mechanism TF2 is attached to the lower plate UP of the fuel cell unit support mechanism FS. Seventh change example Fig. 12 is a side view illustrating a seventh arrangement example of the fuel cell stacks and hydrogen tanks in a case where two hydrogen tank support mechanisms are provided. As illustrated in Fig. 12, the seventh arrangement example differs from the sixth arrangement example in that four hydrogen tanks 21 of the second hydrogen tank group 21B, which are attached to the second hydrogen tank support mechanism TF2, are aligned in a single row in the up-down direction Z. It should be noted that in the first to seventh arrangement examples, the case was described in which the hydrogen tank 21 has a cylindrical shape, but the hydrogen tank 21 can also have a prismatic shape. Additionally, in the fifth to seventh arrangement examples, if one of the first hydrogen tank support mechanism TF1 and the second hydrogen tank support mechanism TF2 is attached to the fuel cell unit support mechanism FS, the other of the first hydrogen tank support mechanism TF1 and the second hydrogen tank support mechanism TF2 need not be directly attached to the fuel cell unit support mechanism FS, as long as the other is attached to the first one. Effects Next, the effects of this revelation will be described. According to the present embodiment, as illustrated in Fig. 2, the fuel cell stack 22 is attached to the fuel cell unit support mechanism FS. Additionally, the hydrogen tank support mechanism TF is attached to the fuel cell unit support mechanism FS, and the hydrogen tank 21 is attached to the hydrogen tank support mechanism TF. Therefore, both the fuel cell stack 22 and the hydrogen tank 21 are fixed such that they are not movable relative to the fuel cell unit support mechanism FS and form an identical vibration system in which the vibration patterns relative to the rotating frame 20 are identical.Accordingly, if the working machine 100 oscillates due to normal driving, lifting and turning, or if the working machine 100 receives shocks, the relative displacement amounts of the fuel cell stack 22 and the hydrogen tank 21 are reduced, and thus the hydrogen lines (the tank hose TH and the stack hose SH) and the connecting sections P1, P2 and P3 thereof are less likely to be damaged, and durability is improved. According to the present embodiment, the damping mechanism DM, as illustrated in Fig. 2, supports the fuel cell unit support mechanism FS relative to the rotating frame 20. Thus, the vibration transmitted from the rotating frame 20 to the fuel cell unit support mechanism FS is damped by the damping mechanism DM. Therefore, the relative displacements of the fuel cell stack 22 and the hydrogen tank 21 when the working machine 100 receives a shock are further reduced, and durability is further improved. According to the present embodiment, as illustrated in Fig. 2, the hydrogen tank support mechanism TF is attached to the upper plate (ceiling section) TP of the fuel cell unit support mechanism FS. This increases the installation height of the hydrogen tank 21, which improves access to the on / off valve 24 of the hydrogen tank 21 and facilitates maintenance of the hydrogen tank 21. Furthermore, because the installation height of the hydrogen tank 21 is increased, the hydrogen tank 21 can be easily installed and removed. According to the present embodiment, as illustrated in Figs. 4, 6 and 8, the hydrogen tank support mechanism TF is attached to the lower plate (bearing section) UP of the fuel cell unit support mechanism FS. This improves access to the fuel cell stack 22 and facilitates maintenance of the fuel cell stack 22. According to the present embodiment, as illustrated in Figs. 3, 5, 7 and 9, the respective inlet / outlet valves 24 of the plurality of hydrogen tanks 21, which are attached to the hydrogen tank support mechanism TF, are arranged on identical sides in the longitudinal direction of the hydrogen tanks 21. This shortens the hydrogen lines (the tank hose TH and the stacking hose SH) and simplifies the arrangement of the hydrogen lines. Therefore, it is possible to suppress stresses on the hydrogen lines and their connecting sections. According to the present embodiment, as illustrated in Figs. 10, 11 to 12, the first hydrogen tank support mechanism TF1 and the second hydrogen tank support mechanism TF2, which are different from each other and support the hydrogen tanks 21, are installed. This makes it possible to attach and detach the hydrogen tank support mechanisms TF1 and TF2 separately, which facilitates maintenance. According to the present embodiment, as illustrated in Figs. 3, 5 and 7, the hydrogen tank 21 is arranged such that its longitudinal direction is aligned with the left-right direction Y of the working machine 100. This makes it difficult for the hydrogen tank 21 to be displaced in any direction of rotation against, for example, a vibration of the rotating body 13. Furthermore, since a dimension of the working machine 100 in the front-back direction X can be reduced, the turning radius of the rotating body 13 can be kept small. According to the present embodiment, as illustrated in Figs. 3, 5 and 7, the hydrogen tank 21 is arranged such that its longitudinal direction lies in the plane that includes the left-right direction Y and the front-back direction X of the working machine 100. This reduces the installation height of the hydrogen tank 21 in the up-down direction Z and improves the rearward visibility for the operator of the working machine 100. According to the present embodiment, as illustrated in Fig. 9, the hydrogen tank 21 is arranged such that its longitudinal direction is aligned with the up-down direction Z of the working machine 100, and the on / off valve 24 of the hydrogen tank 21 is located on the upper side of the hydrogen tank 21. This improves access to the on / off valve 24 and facilitates maintenance of the hydrogen tank 21. According to the present embodiment, as illustrated in Figs. 4, 6 and 8, the hydrogen tank 21 is arranged on the rear side of the fuel cell stack 22. Typically, a hydraulically pressurized device, such as a rotating hydraulic motor, is arranged on the front side of the fuel cell stack 22. Therefore, by arranging the hydrogen tank 21 on the rear side of the fuel cell stack 22, it can be located in a position where the ambient temperature is low. Additions As described above, the embodiment includes the following technical ideas. Supplement 1 A fuel cell unit attached to a vehicle body frame of a working machine, wherein the fuel cell unit includes a fuel cell unit support mechanism coupled to the vehicle body frame, a fuel cell attached to the fuel cell unit support mechanism, a first hydrogen tank support mechanism attached to the fuel cell unit support mechanism, and a first hydrogen tank group attached to the first hydrogen tank support mechanism and including one or more hydrogen tanks that supply hydrogen to the fuel cell. Supplement 2 The fuel cell unit according to Supplement 1, further including a damping mechanism, wherein the fuel cell unit support mechanism and the vehicle body frame are coupled to each other via the damping mechanism. Supplement 3 The fuel cell unit according to Supplement 2, wherein the fuel cell unit support mechanism includes a bearing section coupled to the vehicle body frame, the damping mechanism being arranged between them, a ceiling section protecting an upper section of the fuel cell, and a side frame section connecting the bearing section and the ceiling section, and the first hydrogen tank support mechanism is attached to the ceiling section. Supplement 4 The fuel cell unit according to Supplement 2, wherein the fuel cell unit support mechanism includes a bearing section coupled to the vehicle body frame, the damping mechanism being arranged between them, a ceiling section protecting an upper section of the fuel cell, and a side frame section connecting the bearing section and the ceiling section, and the first hydrogen tank support mechanism is attached to the bearing section. Supplement 5 The fuel cell unit according to one of the amendments 1 to 4, wherein a plurality of the hydrogen tanks enclosed in the first hydrogen tank group is attached to the first hydrogen tank support mechanism and corresponding on / off valves of the plurality of hydrogen tanks attached to the first hydrogen tank support mechanism are arranged on identical sides in a longitudinal direction of the hydrogen tanks. Supplement 6 The fuel cell unit according to any of Supplements 1 to 5, further comprising a second hydrogen tank group which is different from the first hydrogen tank group and includes one or more hydrogen tanks, and a second hydrogen tank support mechanism to which the second hydrogen tank group is attached, wherein the second hydrogen tank support mechanism is attached to the fuel cell unit support mechanism or the first hydrogen tank support mechanism. Supplement 7 The fuel cell unit according to Supplement 6, wherein a plurality of the hydrogen tanks enclosed in the second hydrogen tank group are attached to the second hydrogen tank support mechanism and corresponding on / off valves of the plurality of hydrogen tanks attached to the second hydrogen tank support mechanism are arranged on identical sides in the longitudinal direction of the hydrogen tanks. Supplement 8 The fuel cell unit according to one of the amendments 1 to 7, wherein the longitudinal direction of the hydrogen tanks enclosed in the first hydrogen tank group is aligned with a left-right direction of the working machine. Supplement 9 The fuel cell unit according to one of the amendments 1 to 7, wherein the longitudinal direction of the hydrogen tanks enclosed in the first hydrogen tank group is arranged in a plane that includes a left-right direction and a front-back direction of the working machine. Supplement 10 The fuel cell unit according to one of the amendments 1 to 7, wherein the longitudinal direction of the hydrogen tanks enclosed in the first hydrogen tank group is aligned with an up-down direction of the working machine and the on-off valves of the hydrogen tanks enclosed in the first hydrogen tank group are arranged on an upper side of the hydrogen tanks. Supplement 11 The fuel cell unit according to one of the supplements 1 to 10, wherein the first hydrogen tank group is arranged at a rear of the fuel cell. Supplement 12 A work machine equipped with the fuel cell unit according to one of the amendments 1 to 11. It is understood that the embodiment disclosed herein is in every respect exemplary and not limiting. The scope of protection of the present invention is defined by the claims and not by the preceding description and is intended to include all modifications within the scope and meaning that are equivalent to the content of the claims. Reference symbol list 11 Main body, 12 Working unit, 13 Rotating unit, 14 Cab, 14S Operator seat, 15 Travel body, 15Cr Endless track, 15M Travel motor, 16 Boom, 17 Arm, 18 Bucket, 19a Boom cylinder, 19b Arm cylinder, 19c Bucket cylinder, 20 Rotating frame, 21 Hydrogen tank, 21A, 21B Hydrogen tank assembly, 22 Fuel cell stack, 23 Pressure reducer, 24 On / off valve, 25 Radiator, 26 Electric fan, 100 Working unit, AR Arrangement area, AT Upper arm bolt, BF Boom foot bolt, BT Upper boom bolt, CM Column element, CU Cooling unit, DM Damping mechanism, FCU Fuel cell unit, FS Fuel cell unit support mechanism, OP Outer cladding, P1, P2, P3 Connecting section, RX Slewing axis, SH Stacking hose, TF Hydrogen tank support mechanism TF1 First hydrogen tank support mechanism, TF2 Second hydrogen tank support mechanism, TH Tank hose, TP Upper plate, UP Lower plate QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature WO 2022 / 137688 [0002, 0003]

Claims

Fuel cell unit attached to a vehicle body frame of a work machine, the fuel cell unit comprising: a fuel cell unit support mechanism coupled to the vehicle body frame; a fuel cell attached to the fuel cell unit support mechanism; a first hydrogen tank support mechanism attached to the fuel cell unit support mechanism; and a first hydrogen tank group attached to the first hydrogen tank support mechanism and including one or more hydrogen tanks that supply hydrogen to the fuel cell. Fuel cell unit according to claim 1, further comprising a damping mechanism, wherein the fuel cell unit support mechanism and the vehicle body frame are coupled to each other via the damping mechanism. Fuel cell unit according to claim 2, wherein the fuel cell unit support mechanism includes a bearing section coupled to the vehicle body frame, wherein the damping mechanism is arranged between them, a ceiling section protecting an upper section of the fuel cell, and a side frame section connecting the bearing section and the ceiling section, and the first hydrogen tank support mechanism is attached to the ceiling section. Fuel cell unit according to claim 2, wherein the fuel cell unit support mechanism includes a bearing section coupled to the vehicle body frame, wherein the damping mechanism is arranged between them, a ceiling section protecting an upper section of the fuel cell, and a side frame section connecting the bearing section and the ceiling section, and the first hydrogen tank support mechanism is attached to the bearing section. Fuel cell unit according to claim 1, wherein a plurality of the hydrogen tanks enclosed in the first hydrogen tank group is attached to the first hydrogen tank support mechanism and corresponding on / off valves of the plurality of hydrogen tanks attached to the first hydrogen tank support mechanism are arranged on identical sides in a longitudinal direction of the hydrogen tanks. Fuel cell unit according to claim 1, further comprising: a second hydrogen tank group which differs from the first hydrogen tank group and includes one or more hydrogen tanks; and a second hydrogen tank support mechanism to which the second hydrogen tank group is attached, wherein the second hydrogen tank support mechanism is attached to the fuel cell unit support mechanism or the first hydrogen tank support mechanism. Fuel cell unit according to claim 6, wherein a plurality of the hydrogen tanks enclosed in the second hydrogen tank group are attached to the second hydrogen tank support mechanism and corresponding on / off valves of the plurality of hydrogen tanks attached to the second hydrogen tank support mechanism are arranged on identical sides in a longitudinal direction of the hydrogen tanks. Fuel cell unit according to claim 1, wherein a longitudinal direction of the hydrogen tanks enclosed in the first hydrogen tank group is aligned with a left-right direction of the working machine. Fuel cell unit according to claim 1, wherein a longitudinal direction of the hydrogen tanks enclosed in the first hydrogen tank group is arranged in a plane which includes a left-right direction and a front-back direction of the working machine. Fuel cell unit according to claim 1, wherein a longitudinal direction of the hydrogen tanks enclosed in the first hydrogen tank group is aligned with an up-down direction of the working machine and on-off valves of the hydrogen tanks enclosed in the first hydrogen tank group are arranged on an upper side of the hydrogen tanks. Fuel cell unit according to claim 1, wherein the first hydrogen tank group is arranged at a rear side of the fuel cell. Working machine equipped with the fuel cell unit according to claim 1.

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