Work machine

Abstract

Provided is a work machine capable of efficiently replacing a hydrogen tank in a short time. A work machine comprises: a fuel cell module (30) which is a power source using hydrogen; a hydrogen tank (21) from which hydrogen is supplied to the fuel cell module (30); a flow path (40) for hydrogen from the hydrogen tank (21) to the fuel cell module (30); and a joint (50) which is provided to the flow path (40). The joint (50) has a plug (52) and a socket (51), and is configured so that the plug (52) and the socket (51) can be connected by inserting the plug (52) into the socket (51). The work machine further comprises a pressure-reducing valve (60) for reducing the pressure inside the flow path (40).

Description

Working Machine

[0001] The present disclosure relates to a working machine.

[0002] Japanese Unexamined Patent Publication No. 2024-31601 (Patent Document 1) discloses a construction machine including a positioning member that guides a detachable hydrogen tank unit to a predetermined installation position by abutting against the unit when replacing the unit.

[0003] Japanese Unexamined Patent Publication No. 2024-31601

[0004] As a method for replenishing hydrogen to a working machine including a hydrogen power source which is a power source using hydrogen, it is conceivable to remove an empty hydrogen tank and attach a new hydrogen tank. There is a demand for efficient replacement of hydrogen tanks in a short time.

[0005] The present disclosure proposes a working machine capable of efficiently replacing a hydrogen tank in a short time.

[0006] According to the present disclosure, there is proposed a working machine including: a hydrogen power source which is a power source using hydrogen; a hydrogen tank that supplies hydrogen to the hydrogen power source; a hydrogen flow path from the hydrogen tank to the hydrogen power source; and a joint provided in the flow path. The joint includes a plug and a socket, and is configured such that the plug and the socket can be connected by inserting the plug into the socket. The working machine further includes a pressure reducing valve that reduces pressure inside the flow path.

[0007] According to the working machine of the present disclosure, a hydrogen tank can be efficiently replaced in a short time.

[0008] FIG. 1 is a side view schematically showing the configuration of an excavator. FIG. 2 is a first diagram showing the configuration of a hydrogen flow path from a hydrogen tank to a hydrogen power source. FIG. 3 is a second diagram showing the configuration of a hydrogen flow path from a hydrogen tank to a hydrogen power source. FIG. 4 is a third diagram showing the configuration of a hydrogen flow path from a hydrogen tank to a hydrogen power source. FIG. 5 is a fourth diagram showing the configuration of a hydrogen flow path from a hydrogen tank to a hydrogen power source. FIG. 6 is a fifth diagram showing the configuration of a hydrogen flow path from a hydrogen tank to a hydrogen power source. FIG. 7 is a sixth diagram showing the configuration of a hydrogen flow path from a hydrogen tank to a hydrogen power source. FIG. 8 is a seventh diagram showing the configuration of a hydrogen flow path from a hydrogen tank to a hydrogen power source.

[0009] The embodiments will be described below with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions of them will not be repeated. In the drawings, some configurations may be omitted or simplified for the sake of explanation. It is also intended from the outset that any configuration may be extracted from the embodiments and combined in any way.

[0010] <Overall Structure of the Shovel> Figure 1 is a schematic side view showing the configuration of a shovel 1 as an example of a work machine in one embodiment of the present disclosure. The work machine in this embodiment is, for example, a shovel 1 having a fuel cell.

[0011] As shown in Figure 1, the shovel 1 comprises a main body 11 and a hydraulically operated work implement 12. The main body 11 includes a slewing body 13 and a traveling body 15.

[0012] The vehicle 15 has a pair of left and right tracks 15Cr and a drive motor 15M. The shovel 1 can move by the rotation of the tracks 15Cr. The drive motor 15M is provided as the drive source for the vehicle 15.

[0013] The slewing body 13 is positioned on and supported by the traveling body 15. The slewing body 13 is capable of rotating relative to the traveling body 15 about a pivot axis RX by a slewing motor (not shown). The pivot axis RX is a hypothetical straight line that serves as the pivot center of the slewing body 13.

[0014] The slewing body 13 has a cab 14. Inside the cab 14 is a driver's seat 14S where the operator sits. The operator can sit in the driver's seat 14S and operate the work implement 12, rotate the slewing body 13 relative to the traveling body 15, and move the shovel 1 using the traveling body 15.

[0015] The work implement 12 is supported by a slewing body 13. The work implement 12 has a boom 16, an arm 17, and a bucket 18. The work implement 12 further has a boom cylinder 19a, an arm cylinder 19b, and a bucket cylinder 19c.

[0016] The base end of the boom 16 is rotatably connected to the slewing body 13 with the boom foot pin BF as the pivot point. The base end of the arm 17 is rotatably connected to the tip of the boom 16 with the boom top pin BT as the pivot point. The base end of the bucket 18 is rotatably connected to the tip of the arm 17 with the arm top pin AT as the pivot point.

[0017] The rotating body 13 further comprises an exterior panel OP surrounding the machine room 20, a hydrogen tank 21, and a fuel cell module 30. The hydrogen tank 21, fuel cell module 30, etc., are arranged inside the machine room 20 of the rotating body 13. The hydrogen tank 21, fuel cell module 30, etc., are surrounded by the exterior panel OP. The machine room 20 is partitioned inside the exterior panel OP. The exterior panel OP separates the internal space of the machine room 20 from the outside of the machine room 20.

[0018] The fuel cell module 30 includes a fuel cell stack 31 and auxiliary equipment 32 for the fuel cell stack 31.

[0019] The hydrogen tank 21 stores hydrogen. The hydrogen tank 21 is connected to the fuel cell stack 31. The hydrogen stored in the hydrogen tank 21 is depressurized by a pressure reducer and supplied to the fuel cell stack 31. The excavator 1 has, for example, two hydrogen tanks 21, but the number of hydrogen tanks 21 mounted on the excavator 1 is not limited to two. Each hydrogen tank 21 has a cylindrical outer shape.

[0020] The fuel cell stack 31 is constructed by stacking multiple fuel cell cells connected in series. The fuel cell stack 31 generates electricity (electrical energy) by a chemical reaction between hydrogen and oxygen. The generated electrical energy drives a hydraulic pump (not shown) via an electric motor. The hydraulic fluid discharged from the hydraulic pump, driven by the hydraulic pump, operates each hydraulic actuator (swing motor, travel motor, and each hydraulic cylinder).

[0021] If electric motors are used instead of hydraulic actuators, the generated electrical energy is supplied directly to each electric motor. In this example, the excavator 1 has one fuel cell stack 31, but the number of fuel cell stacks 31 mounted on the excavator 1 is not limited to one, and may be multiple.

[0022] The auxiliary equipment 32 operates the fuel cell stack 31, which acts as the main engine. The auxiliary equipment 32 includes a compressor, piping, a controller, a DC-DC converter, etc. (not shown). The compressor supplies air to the fuel cell stack 31. The controller controls the compressor and communicates with external devices of the fuel cell module 30.

[0023] <Configuration of the hydrogen flow path> Figure 2 is a first diagram showing the configuration of the hydrogen flow path 40 from the hydrogen tank 21 to the hydrogen power source (fuel cell module 30). The high-pressure hydrogen gas filled in the hydrogen tank 21 flows through the flow path 40 and is supplied to the fuel cell module 30. The flow path 40 forms a path through which the hydrogen gas flows. The flow path 40 may include piping. The flow path 40 may include hoses. A joint 50 is provided in the flow path 40. The flow path 40 includes a first flow path section 41 upstream of the joint 50 in the direction of hydrogen gas flow from the hydrogen tank 21 to the fuel cell module 30, and a second flow path section 42 downstream of the joint 50 in the direction of hydrogen gas flow.

[0024] The joint 50 is a component that connects the first flow channel section 41 and the second flow channel section 42. The joint 50 has a socket 51 and a plug 52. The socket 51 is connected to the downstream end of the first flow channel section 41. The plug 52 is connected to the upstream end of the second flow channel section 42. In the joint 50, the plug 52 is the male component, and the socket 51 is the female component. The plug 52 has a convex portion. The socket 51 has a concave portion into which the convex portion of the plug 52 can be inserted.

[0025] The plug 52 and socket 51 can be connected by inserting the plug 52 into the socket 51. By simply inserting the plug 52 into the socket 51, the plug 52 and socket 51 are fixed to each other and are airtightly connected. With the plug 52 and socket 51 connected, the first flow path section 41 and the second flow path section 42 are in communication via the joint 50. A path is formed through which hydrogen gas flows from the hydrogen tank 21 to the fuel cell module 30.

[0026] The fitting 50 is configured so that an operator can connect and disconnect the plug 52 and the socket 51 by hand without using tools. In order to enable manual attachment and detachment of the plug 52 and the socket 51, the pressure inside the flow path 40 must be kept below a certain level. If the pressure inside the flow path 40 is high, it will not be possible to remove the plug 52 from the socket 51 by hand.

[0027] Therefore, a pressure reducing valve 60 is provided in the first flow path section 41 between the hydrogen tank 21 and the fitting 50. The pressure reducing valve 60 is located upstream of the fitting 50 in the direction of hydrogen gas flow. The pressure reducing valve 60 reduces the pressure inside the first flow path section 41. The pressure reducing valve 60 may have a known structure in which it has a pressure regulating spring and a valve seat, and the valve seat is activated by the difference between the spring force of the pressure regulating spring and the pressure of the hydrogen gas inside the first flow path section 41 to adjust the pressure of the hydrogen gas.

[0028] A set pressure is set for the pressure reducing valve 60. The set pressure can be set arbitrarily, but it is set to a pressure higher than atmospheric pressure. The pressure reducing valve 60 opens when the hydrogen gas pressure is higher than the set pressure, releasing the hydrogen gas inside the first flow path section 41 into the atmosphere and lowering the hydrogen gas pressure inside the first flow path section 41. When the hydrogen gas pressure drops to the set pressure, the pressure reducing valve 60 closes, stopping the release of hydrogen gas into the atmosphere.

[0029] By installing a pressure reducing valve 60 in the hydrogen gas flow path 40 from the hydrogen tank 21 to the fuel cell module 30, the pressure inside the flow path 40 can be reduced to the point where the plug 52 can be removed from the socket 51 by hand. Since the plug 52 and socket 51 can be separated and the plug 52 can be attached to the socket 51 by hand without the use of tools, the working time can be reduced. When the hydrogen tank 21 is empty, the plug 52 and socket 51 can be separated in a short time, and the empty hydrogen tank 21 can be removed in a short time. Since the plug 52 can be inserted into the socket 51 at the end of the first flow path section 41 which is connected to the new hydrogen tank 21, the new hydrogen tank 21 can be attached in a short time. Therefore, the hydrogen tank 21 can be replaced efficiently in a short time.

[0030] The pressure reducing valve 60 may reduce the pressure inside the flow path 40 to a level higher than atmospheric pressure. If the pressure inside the flow path 40 is reduced to atmospheric pressure, there is a possibility that oxygen-containing air will flow into the flow path 40. By setting the pressure of the pressure reducing valve 60 to a level higher than atmospheric pressure, it is possible to suppress the inflow of oxygen into the flow path 40.

[0031] At least one of the second flow channel section 42, including the portion connected to the plug 52, and at least one of the first flow channel section 41, including the portion connected to the socket 51, may be flexible. For example, the portion of the second flow channel section 42 connected to the plug 52 and the portion of the first flow channel section 41 connected to the socket 51 may be formed from a rubber or resin hose or a flexible tube. This allows the first flow channel section 41 and / or the second flow channel section 42 to bend, making it easier to manually attach and detach the plug 52 and the socket 51.

[0032] Figure 3 is a second diagram showing the configuration of the hydrogen flow path 40 from the hydrogen tank 21 to the hydrogen power source (fuel cell module 30). As shown in Figure 3, the pressure reducing valve 60 may be provided in the second flow path section 42 between the joint 50 and the fuel cell module 30. The pressure reducing valve 60 may be provided downstream of the joint 50 in the direction of hydrogen gas flow. The pressure reducing valve 60 may reduce the pressure inside the second flow path section 42. The pressure reducing valve 60 may release the hydrogen gas inside the second flow path section 42 into the atmosphere to reduce the pressure of the hydrogen gas inside the second flow path section 42.

[0033] By providing the pressure reducing valve 60 in the second flow path section 42, which is closer to the fuel cell module 30 than the joint 50, one pressure reducing valve 60 is always installed on the shovel 1. This eliminates the need to provide a pressure reducing valve in the first flow path section 41, which is replaced integrally with the hydrogen tank 21. This eliminates the need to provide one pressure reducing valve for each hydrogen tank 21, thus reducing the number of pressure reducing valves, simplifying the configuration, and lowering the cost of the hydrogen tanks 21.

[0034] Figure 4 is a third diagram showing the configuration of the hydrogen flow path 40 from the hydrogen tank 21 to the hydrogen power source (fuel cell module 30). In the example shown in Figure 4, in addition to the configuration shown in Figure 2, a first gate valve 71 is provided in the first flow path section 41 between the joint 50 and the hydrogen tank 21 to partition the first flow path section 41. A second gate valve 72 is provided in the second flow path section 42 between the joint 50 and the fuel cell module 30 to partition the second flow path section 42. The first gate valve 71 and the second gate valve 72 may be any type of valve, such as a globe valve, ball valve, gate valve, or butterfly valve. The first gate valve 71 and the second gate valve 72 may be manually operated valves that can be opened and closed by hand, or they may be solenoid valves or electric valves.

[0035] The pressure reducing valve 60 is installed in the first flow path section 41 between the joint 50 and the first gate valve 71. The pressure reducing valve 60 reduces the pressure inside the first flow path section 41 between the joint 50 and the first gate valve 71. The pressure reducing valve 60 releases the hydrogen gas inside the first flow path section 41 between the joint 50 and the first gate valve 71 into the atmosphere, thereby lowering the pressure of the hydrogen gas inside the first flow path section 41 between the joint 50 and the first gate valve 71.

[0036] When attaching or detaching the plug 52 and socket 51, the first gate valve 71 is closed, and the hydrogen tank 21 and the fitting 50 are disconnected. In this state, the pressure inside the first flow path section 41 between the fitting 50 and the first gate valve 71 is reduced. Since the hydrogen tank 21 no longer affects the pressure reduction inside the first flow path section 41 by the pressure reducing valve 60, the pressure inside the first flow path section 41 can be reliably reduced to a level where the plug 52 and socket 51 can be attached and detached manually. In this state, the plug 52 and socket 51 can be attached and detached without using tools, allowing the hydrogen tank 21 to be replaced efficiently in a short amount of time.

[0037] Figure 5 is a fourth diagram showing the configuration of the hydrogen flow path 40 from the hydrogen tank 21 to the hydrogen power source (fuel cell module 30). As shown in Figure 5, the pressure reducing valve 60 may be provided in the second flow path section 42 between the joint 50 and the second gate valve 72. The pressure reducing valve 60 may reduce the pressure inside the second flow path section 42 between the joint 50 and the second gate valve 72. The pressure reducing valve 60 may release the hydrogen gas inside the second flow path section 42 between the joint 50 and the second gate valve 72 into the atmosphere, thereby reducing the pressure of the hydrogen gas inside the second flow path section 42 between the joint 50 and the second gate valve 72.

[0038] When attaching or detaching the plug 52 and socket 51, the second gate valve 72 is closed, and the fuel cell module 30 and the fitting 50 are disconnected. In this state, the pressure inside the second flow path section 42 between the fitting 50 and the second gate valve 72 is reduced. Since the fuel cell module 30 no longer affects the pressure reduction inside the second flow path section 42 by the pressure reducing valve 60, the pressure inside the second flow path section 42 can be reliably reduced to a level where the plug 52 and socket 51 can be attached and detached manually. In this state, the hydrogen tank 21 can be replaced efficiently in a short time by attaching and detaching the plug 52 and socket 51 without using tools.

[0039] Figure 6 is a fifth diagram showing the configuration of the hydrogen flow path 40 from the hydrogen tank 21 to the hydrogen power source (fuel cell module 30). In the example shown in Figure 6, in addition to the configuration shown in Figure 4, a second pressure reducing valve 80 is provided in the first flow path section 41 between the joint 50 and the hydrogen tank 21. Specifically, the second pressure reducing valve 80 is provided in the first flow path section 41 between the first gate valve 71 and the hydrogen tank 21. A third gate valve 73 is provided in the first flow path section 41 between the second pressure reducing valve 80 and the hydrogen tank 21 to partition the first flow path section 41. The third gate valve 73 may be any type of valve. The third gate valve 73 may be a manual valve, a solenoid valve, or an electric valve.

[0040] The second pressure reducing valve 80 reduces the pressure of the hydrogen gas supplied from the hydrogen tank 21 to the fuel cell module 30. The hydrogen tank 21 is filled with compressed, high-pressure hydrogen gas to allow for a larger volume of hydrogen gas to be supplied. The second pressure reducing valve 80 reduces the pressure of the high-pressure hydrogen gas in the hydrogen tank 21 to a level that can be handled by the fuel cell module 30. This ensures that hydrogen gas with the appropriate pressure is reliably supplied to the fuel cell module 30.

[0041] The first gate valve 71, which partitions the first flow path section 41, is installed between the second pressure reducing valve 80 and the fitting 50. The pressure reducing valve 60 is installed in the first flow path section 41 between the fitting 50 and the first gate valve 71, and reduces the pressure inside the first flow path section 41 between the fitting 50 and the first gate valve 71. When attaching or detaching the plug 52 and the socket 51, at least one of the first gate valve 71 and the third gate valve 73 is closed, and in that state, the pressure reducing valve 60 reduces the pressure inside the first flow path section 41. Since the hydrogen tank 21 no longer affects the pressure reduction inside the first flow path section 41 by the pressure reducing valve 60, the pressure inside the first flow path section 41 can be reliably reduced to a level where the plug 52 and the socket 51 can be attached and detached manually.

[0042] Fig. 7 is a sixth diagram showing the configuration of a hydrogen flow path 40 from a hydrogen tank 21 to a hydrogen power source (fuel cell module 30). As shown in Fig. 7, the pressure reducing valve 60 may be provided in the second flow path section 42 between the joint 50 and the second gate valve 72. The pressure reducing valve 60 may depressurize the interior of the second flow path section 42 between the joint 50 and the second gate valve 72. The pressure reducing valve 60 may release hydrogen gas inside the second flow path section 42 between the joint 50 and the second gate valve 72 to the atmosphere, thereby reducing the pressure of the hydrogen gas inside the second flow path section 42 between the joint 50 and the second gate valve 72.

[0043] Fig. 8 is a seventh diagram showing the configuration of a hydrogen flow path 40 from a hydrogen tank 21 to a hydrogen power source (fuel cell module 30). As shown in Fig. 8, the pressure reducing valve 60 may be provided in the first flow path section 41 between the second pressure reducing valve 80 and the first gate valve 71. The pressure reducing valve 60 may depressurize the interior of the first flow path section 41 between the second pressure reducing valve 80 and the first gate valve 71. The pressure reducing valve 60 may release hydrogen gas inside the first flow path section 41 between the second pressure reducing valve 80 and the first gate valve 71 to the atmosphere, thereby reducing the pressure of the hydrogen gas inside the first flow path section 41 between the second pressure reducing valve 80 and the first gate valve 71.

[0044] When attaching and detaching the plug 52 and the socket 51, the first gate valve 71 is opened and the third gate valve 73 is closed, and in this state, the interior of the first flow path section 41 is depressurized by the pressure reducing valve 60. Since the hydrogen tank 21 no longer affects the depressurization of the interior of the first flow path section 41 performed by the pressure reducing valve 60, the interior of the first flow path section 41 can be reliably depressurized to a degree that allows manual attachment and detachment of the plug 52 and the socket 51.

[0045] The working machine to which the present disclosure is applied is not limited to excavators, and may be other types of working machines including bulldozers, wheel loaders, motor graders, dump trucks and forklifts having a fuel cell. Further, the working machine to which the present disclosure is applied is not limited to those including a fuel cell, as long as it has a hydrogen power source that is a power source using hydrogen. In addition to fuel cells, the hydrogen power source may be, for example, a hydrogen co-firing engine that burns hydrogen by mixing it with fossil fuel, or may be a hydrogen exclusive combustion engine that burns only hydrogen without using fossil fuel.

[0046] In the embodiment, a working machine including a hydrogen power source and a hydrogen tank has been described, but the working machine does not necessarily have to include a hydrogen power source and a hydrogen tank. The idea of the present disclosure may be applied to a working machine including a container filled with compressed gas and a flow passage through which gas flowing out from the container passes, the working machine being configured such that the flow passage can be connected and disconnected in the middle or at an end of the flow passage, for example, for replacing the container.

[0047] <Supplementary Note> The above description includes the features set forth in the following supplementary notes.

[0048] (Supplementary Note 1) A working machine, comprising: a hydrogen power source that is a power source using hydrogen; a hydrogen tank configured to supply hydrogen to the hydrogen power source; a hydrogen flow passage from the hydrogen tank to the hydrogen power source; a joint provided in the flow passage, the joint including a plug and a socket, the plug and the socket being connectable by inserting the plug into the socket; and a pressure reducing valve configured to reduce pressure inside the flow passage.

[0049] (Supplementary Note 2) The working machine according to Supplementary Note 1, further comprising a gate valve provided in at least one of the flow passage between the joint and the hydrogen power source and the flow passage between the joint and the hydrogen tank, the gate valve partitioning the flow passage.

[0050] (Supplementary Note 3) The working machine according to Supplementary Note 2, wherein the pressure reducing valve reduces pressure inside the flow passage between the joint and the gate valve.

[0051] (Supplementary Note 4) The working machine according to any one of Supplementary Notes 1 to 3, further comprising a second pressure reducing valve provided in the flow passage between the joint and the hydrogen tank, the second pressure reducing valve reducing pressure of hydrogen supplied to the hydrogen power source.

[0052] (Supplementary Note 5) The working machine according to Supplementary Note 4, further comprising a gate valve provided in the flow passage between the second pressure reducing valve and the joint, the gate valve partitioning the flow passage.

[0053] (Supplementary Note 6) The working machine according to Supplementary Note 5, wherein the pressure reducing valve reduces pressure inside the flow passage between the second pressure reducing valve and the gate valve.

[0054] (Note 7) The pressure reducing valve is a working machine according to any one of Notes 1 to 6, which reduces the pressure inside the flow path to a pressure higher than atmospheric pressure.

[0055] (Note 8) The working machine according to any one of Notes 1 to 7, wherein the flow path has a first flow path section connected to the socket and a second flow path section connected to the plug, and at least one of the first flow path section and the second flow path section is flexible.

[0056] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope of equivalents of the claims are intended.

[0057] 1 Shovel, 11 Main body, 12 Working equipment, 13 Slewing body, 20 Machine room, 21 Hydrogen tank, 30 Fuel cell module, 31 Fuel cell stack, 32 Auxiliary equipment, 40 Flow path, 41 First flow path section, 42 Second flow path section, 50 Fittings, 51 Socket, 52 Plug, 60 Pressure reducing valve, 71 First gate valve, 72 Second gate valve, 73 Third gate valve, 80 Second pressure reducing valve.

Claims

1. A work machine comprising: a hydrogen power source which is a power source that utilizes hydrogen; a hydrogen tank which supplies hydrogen to the hydrogen power source; a hydrogen flow path from the hydrogen tank to the hydrogen power source; a coupling provided in the flow path which has a plug and a socket and which can connect the plug and the socket by inserting the plug into the socket; and a pressure reducing valve which reduces the pressure inside the flow path.

2. The work machine according to claim 1, further comprising a gate valve provided in at least one of the flow path between the joint and the hydrogen power source and the flow path between the joint and the hydrogen tank, for partitioning the flow path.

3. The working machine according to claim 2, wherein the pressure reducing valve reduces the pressure inside the flow path between the joint and the gate valve.

4. The working machine according to claim 1, further comprising a second pressure reducing valve provided in the flow path between the joint and the hydrogen tank for reducing the pressure of hydrogen supplied to the hydrogen power source.

5. The work machine according to claim 4, further comprising a gate valve provided in the flow path between the second pressure reducing valve and the fitting, for partitioning the flow path.

6. The working machine according to claim 5, wherein the pressure reducing valve reduces the pressure inside the flow path between the second pressure reducing valve and the gate valve.

7. The working machine according to claim 1, wherein the pressure reducing valve reduces the pressure inside the flow path to a pressure higher than atmospheric pressure.

8. The working machine according to claim 1, wherein the flow path has a first flow path section connected to the socket and a second flow path section connected to the plug, and at least one of the first flow path section and the second flow path section is flexible.

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