Work machine

Abstract

To secure an installation space for a hydrogen tank while considering attachment / detachment workability of a counterweight.SOLUTION: A working machine 1 includes a lower traveling body 10 and an upper turning body 20 turnably provided with respect to the lower traveling body 10, wherein the upper turning body 20 includes a main body part (refer to a range A), a power source 40 using hydrogen as fuel provided in the main body part, a counterweight 23 detachably provided on a rear side of the main body part, and a hydrogen tank unit HTU provided on the main body part and supplying hydrogen to the power source 40, wherein the hydrogen tank unit HTU includes a rear part (refer to a range B) positioned on the counterweight 23, and the counterweight 23 includes a hanging part 23A at a position avoiding the rear part accessible from above.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a work machine. [Background technology]

[0002] BACKGROUND ART A work machine is known in which at least a part of an energy storage system including a fuel cell is installed as part of a counterweight (see Patent Document 1).

[0003] Specifically, an energy storage system including a fuel cell is provided at a counterweight provided on the upper rotating body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-9589 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, when the fuel cell is a hydrogen fuel cell, it is necessary to provide the work machine with a hydrogen tank for storing hydrogen, which is the energy source.

[0006] On the other hand, the counterweight needs to be removed when performing maintenance on the internal equipment. Therefore, if a hydrogen tank or the like is placed as part of the counterweight, the gas piping that supplies hydrogen to the hydrogen fuel cell must be disconnected every time maintenance work is performed on the internal equipment, and there is a risk of leaks occurring during this work.

[0007] Furthermore, when a hydrogen tank or the like is placed as part of the counterweight, the design must take into account the alignment of the piping connections so that the gas piping can be connected properly during the counterweight installation work, which could increase the cost of the aircraft.

[0008] On the other hand, when hydrogen is used as fuel, it is stored in the work machine in the form of a high-pressure gas, and therefore its energy density per volume is lower than that of diesel fuel, etc.

[0009] For this reason, when hydrogen is used as fuel, there is a demand for securing a large storage space.

[0010] The present invention has been made in view of the above circumstances, and has as its object to ensure installation space for a hydrogen tank while taking into consideration the ease of attaching and detaching the counterweight. [Means for solving the problem]

[0011] In order to achieve the above object, the present invention is realized by the following configuration. The work machine of the present invention comprises: a lower running body; an upper rotating body that is rotatably provided with respect to the lower traveling body, The upper rotating body is a main body; a hydrogen-fueled power source provided within the main body; a counterweight detachably provided on the rear side of the main body; a hydrogen tank unit provided on the main body and supplying the hydrogen to the power source, the hydrogen tank unit has a rear portion positioned on the counterweight, The counterweight has a hanging portion at a position that avoids the rear portion, which is accessible from above. [Effects of the Invention]

[0012] According to the present invention, it is possible to ensure installation space for a hydrogen tank while taking into consideration the ease of attaching and detaching the counterweight. [Brief explanation of the drawings]

[0013] [Figure 1]1 is a side view of a work machine according to a first embodiment of the present invention. [Figure 2] FIG. 1 is a rear view of a work machine according to a first embodiment of the present invention. [Figure 3] 1 is a top view of a work machine according to a first embodiment of the present invention. FIG. [Figure 4] FIG. 1 is a block diagram for explaining a drive system of a work machine according to a first embodiment of the present invention. [Figure 5] FIG. 3 is a diagram for explaining the work of attaching and detaching the counterweight of the first embodiment according to the present invention to and from the upper rotating body. [Figure 6] FIG. 4 is a diagram for explaining a work machine according to a second embodiment of the present invention. [Figure 7] FIG. 4 is a diagram for explaining a work machine according to a third embodiment of the present invention. [Figure 8] FIG. 10 is a diagram for explaining a work machine according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, modes for carrying out the present invention (hereinafter also referred to as embodiments) will be described in detail with reference to the accompanying drawings. It should be noted that the same elements are denoted by the same numbers or symbols throughout the description of the embodiments.

[0015] However, please note that in consideration of the ease of viewing the drawings, not all of the same elements are numbered or marked, and some elements are not numbered or marked.

[0016] <<First Embodiment>> A working machine 1 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 5. FIG. In the first embodiment, the work machine 1 is shown as a crawler-type shovel, but the work machine 1 does not have to be limited to a shovel and may be other heavy machinery (for example, a demolition machine, a loading machine, an agricultural machine, etc.).

[0017] FIG. 1 is a side view of a work machine 1 according to a first embodiment of the present invention. Note that Figure 1 is a right side view of the side of the work machine 1 that is on the right side when looking at the upper rotating body 20 from the rear, with the side where the operator's cab 21 of the upper rotating body 20 is located being the front and the opposite side being the rear.

[0018] In the following description of the upper rotating body 20, the side where the operator's cab 21 is located will be referred to as the front, and the opposite side will be referred to as the rear. When looking at the upper rotating body 20 from the rear, the left side will be referred to as the left, and the right side will be referred to as the right.

[0019] It should be noted that since the upper rotating body 20 rotates relative to the lower traveling body 10, the definition of the direction of the upper rotating body 20 and the definition of the direction of the lower traveling body 10 may not coincide with each other.

[0020] Therefore, in the following description of the lower running structure 10, directions will be explained based on the running direction during normal running operation.

[0021] Specifically, the forward direction during normal running operation of the lower running body 10 will be described as the forward direction (forward direction forward, forward side, etc.), and conversely, the backward direction will be described as the backward direction (backward direction forward, backward side of the forward direction, etc.).

[0022] FIG. 2 is a rear view of the work machine 1 of the first embodiment according to the present invention, as seen from the left side of FIG. In FIG. 2, the working mechanism 30 is not shown.

[0023] FIG. 3 is a top view of the work machine 1 of the first embodiment according to the present invention. In FIG. 3, the top surface of the housing CS of the hydrogen tank unit HTU is not shown, and the hydrogen tank 50 and other components arranged inside the housing CS are shown so as to be clearly visible.

[0024] FIG. 4 is a block diagram for explaining a drive system 40 of the work machine 1 of the first embodiment according to the present invention. Please note that Figure 4 is an illustration for making the hydraulic flow easier to understand, and does not necessarily correspond to the actual arrangement.

[0025] As shown in Figures 1 to 3, the work machine 1 comprises a lower running body 10, an upper rotating body 20 that is rotatably mounted relative to the lower running body 10, and a work mechanism 30 that is mounted on the upper rotating body 20 so as to be capable of raising and lowering, and has an attachment 33 at its tip.

[0026] [Undercarriage 10] In the first embodiment, the lower traveling body 10 is of a crawler type. As shown in FIG. 2, the lower traveling body 10 includes a frame 11 and a traveling mechanism 12 (the mechanism itself is not shown) provided on the frame 11.

[0027] (Frame 11) The frame 11 includes a central frame 11A located in the center and a pair of spaced apart crawler frames 11B arranged in a direction (also referred to as a first direction) perpendicular to the traveling direction of the lower traveling body 10.

[0028] Specifically, the crawler frames 11B are integrally provided on both ends of the central frame 11A in the first direction.

[0029] (Traveling mechanism 12) Although not specifically shown, the traveling mechanism 12 is a mechanism for traveling provided on a general crawler-type lower traveling body 10.

[0030] For example, the running mechanism 12 includes a front idler provided on the front side of the crawler frame 11B in the forward direction, a sprocket provided on the rear side of the crawler frame 11B in the forward direction, an upper roller provided between the front idler and the sprocket on the upper side of the crawler frame 11B, a lower roller provided between the front idler and the sprocket on the lower side of the crawler frame 11B, and a rubber crawler provided to surround the front idler, sprocket, upper roller, and lower roller.

[0031] [Upper rotating body 20] As shown in Figures 1 to 3, the upper rotating body 20 comprises a main body (see Figures 1 and range A in Figure 3), an operator's cab 21 provided in front of the main body of the upper rotating body 20, and a machine room 22 (see Figures 1 and 3) provided behind the operator's cab 21 of the main body.

[0032] The operator's cab 21 is provided with an operation unit (not shown) for an operator to sit in and perform various operations.

[0033] The upper rotating body 20 also includes a power source 41 (see Figure 4) (described later) provided within the main body, an operating pump 42 (see Figure 4) (described later) provided within the main body, a hydraulic oil tank 42A (see Figure 4) (described later) provided within the main body, a control valve 43 (described later) provided within the main body, and a rotating motor 44A (described later) provided within the main body.

[0034] More specifically, the upper rotating body 20 has a power source 41 (see Figure 4), an operating pump 42 (see Figure 4), a hydraulic oil tank 42A (see Figure 4), a control valve 43, and a rotating motor 44A inside a machine room 22 provided in the main body (see Figures 1 and range A in Figure 3).

[0035] Furthermore, the upper rotating body 20 is equipped with a counterweight 23 that is detachably mounted on the rear side of the main body (see Figures 1 and range A in Figure 3), and a hydrogen tank unit HTU that is mounted on the main body and supplies hydrogen to the power source 41 (see Figure 4).

[0036] More specifically, the upper rotating body 20 includes a counterweight 23 located rearward of a machine room 22 provided in the main body (see range A in Figures 1 and 3), and a hydrogen tank unit HTU located above the machine room 22 provided in the main body (see range A in Figures 1 and 3). The counterweight 23 and the hydrogen tank unit HTU will be described in detail later.

[0037] [Working mechanism 30] The working mechanism 30 comprises a boom 31 whose base end is capable of being raised and lowered relative to the upper rotating body 20, an arm 32 whose base end is rotatably mounted relative to the tip of the boom 31, and an attachment 33 (in this example, a bucket) whose base end is rotatably mounted to the tip of the arm 32.

[0038] The working mechanism 30 also includes a boom cylinder 31A for raising and lowering the boom 31 relative to the upper rotating body 20, an arm cylinder 32A for rotating the arm 32 relative to the boom 31, and an attachment cylinder 33A for rotating the attachment 33 relative to the arm 32.

[0039] The boom cylinder 31A, the arm cylinder 32A, and the attachment cylinder 33A are all hydraulic cylinders.

[0040] [Drivetrain 40] As shown in FIG. 4, the drive system 40 includes a power source 41, a working pump 42, a control valve 43, and a drive unit 44.

[0041] (Power source 41) The power source 41 is provided in the machine room 22 of the upper rotating body 20 and is a mechanism that generates power for driving the operating pump 42.

[0042] In the first embodiment, the power source 41 includes a hydrogen fuel cell 41A that generates electricity by reacting hydrogen supplied as fuel from a hydrogen tank 50 with oxygen in the air, and an electric motor 41B that is driven by the electricity generated by the hydrogen fuel cell 41A. The power source 41 may further include a secondary cell (a so-called battery) or the like.

[0043] The rotary shaft of the electric motor 41B is connected to the rotary shaft of the working pump 42, and the working pump 42 is driven by the driving of the electric motor 41B.

[0044] The electric motor 41B is, for example, a three-phase motor, and is integrally provided with an inverter that performs current control for rotation control.

[0045] The inverter converts the direct current from the hydrogen fuel cell 41A into three-phase alternating current, which is supplied to the electric motor 41B, causing the electric motor 41B to rotate.

[0046] The power source 41 may be a hydrogen engine or the like that operates as an internal combustion engine that burns hydrogen supplied from a hydrogen tank 50 as fuel, instead of the configuration of the hydrogen fuel cell 41A and the electric motor 41B.

[0047] In this way, the power source 41 does not need to be limited to the configuration of the first embodiment, and may be any mechanism that generates power for driving the actuation pump 42 using hydrogen as fuel.

[0048] (Operating pump 42) The hydraulic pump 42 is provided in the machine room 22 of the upper rotating body 20 and is a hydraulic pump that sends hydraulic oil from a hydraulic oil tank 42A provided in the machine room 22 of the upper rotating body 20 to the control valve 43. In other words, the hydraulic pump 42 is a mechanism that generates hydraulic pressure that is controlled by the control valve 43 .

[0049] (Control valve 43) The control valve 43 is provided in the machine room 22 of the upper rotating body 20, and is a valve that controls the supply of hydraulic oil to the drive unit 44 and the return of hydraulic oil from the drive unit 44 in accordance with the operation (operation by the operator) of an operating unit (not shown) for performing various operations provided in the driver's cab 21.

[0050] (Driver 44) The drive unit 44 includes a swing motor 44A, which is a hydraulic motor provided on the upper swing body 20, a work mechanism cylinder 44B, which is a hydraulic cylinder provided on the work mechanism 30, and a travel motor 44C, which is a hydraulic motor provided on each of the pair of travel mechanisms 12.

[0051] The swing motor 44A, the working mechanism cylinder 44B, and the traveling motor 44C are driven in accordance with the state of the hydraulic pressure (working oil) controlled by the control valve 43.

[0052] The swing motor 44A is a motor for swinging the upper swing body 20 relative to the lower traveling body 10, and the working mechanism cylinder 44B is the boom cylinder 31A, arm cylinder 32A, and attachment cylinder 33A shown above. The travel motor 44C is a motor for driving the crawler for travel.

[0053] [Hydrogen Tank Unit HTU] As shown in Figure 3, the hydrogen tank unit HTU comprises a plurality of hydrogen tanks 50, a junction valve 51 that joins hydrogen supplied from the plurality of hydrogen tanks 50, a hydrogen supply line HL1 that connects each hydrogen tank 50 to the junction valve 51, a hydrogen filling port 52 to which hydrogen is supplied from the outside, a hydrogen supply line HL2 that connects the hydrogen filling port 52 to the junction valve 51, a pressure reducing valve 53 that reduces the pressure of hydrogen supplied from the upstream side and passes it to the downstream side, a hydrogen supply line HL3 that connects the pressure reducing valve 53 to the junction valve 51, and a housing CS that houses these components.

[0054] In other words, the housing CS houses multiple hydrogen tanks 50, a junction valve 51, a hydrogen filling port 52, and a pressure reducing valve 53, all of which are connected by hydrogen supply lines (hydrogen supply line HL1, hydrogen supply line HL2, and hydrogen supply line HL3).

[0055] In the first embodiment, the hydrogen tank unit HTU is equipped with a hydrogen detector (not shown) installed at a higher position than the hydrogen tank 50 etc. inside the housing CS, and when the hydrogen detector detects a hydrogen leak, it sounds a buzzer to alert nearby workers and the operator operating the work machine 1 to the hydrogen leak.

[0056] However, the notification does not have to be limited to a buzzer, and a visual method such as a patrol lamp may be used to notify nearby workers or the operator of the work machine 1 of a hydrogen leak.

[0057] On the other hand, high-pressure hydrogen having the same pressure as the hydrogen filling pressure of the hydrogen tank 50 (for example, about 70 MPa) flows through the hydrogen supply line HL1, hydrogen supply line HL2, and hydrogen supply line HL3.

[0058] For this reason, the hydrogen supply line HL1, the hydrogen supply line HL2, and the hydrogen supply line HL3 are required to have high strength (high pressure resistance), and it is also necessary to consider that they will not deform or break when stress, etc. is applied.

[0059] Therefore, it is preferable to use, for example, stainless steel pipes of 3 / 8 inch or more for the gas pipes forming the hydrogen supply line HL1, the hydrogen supply line HL2, and the hydrogen supply line HL3.

[0060] The hydrogen tank unit HTU is also connected to the downstream side of the pressure reducing valve 53 and includes a hydrogen supply line HL4 (see FIG. 1) for supplying hydrogen decompressed by the pressure reducing valve 53 to the inside of the machine room 22.

[0061] The hydrogen supply line HL4 extends outside the casing CS toward the interior of the machine room 22 through a piping outlet provided in the casing CS.

[0062] The machine room 22 is also provided with a piping receiving port for receiving the hydrogen supply line HL4 into the machine room 22.

[0063] The downstream end of the hydrogen supply line HL4 is detachably connected to the hydrogen supply line HL extending from the hydrogen fuel cell 41A at a connection point CP.

[0064] For example, the connection part CP may be a so-called coupler for general hydrogen gas, which comprises a plug and a socket into which the plug is inserted.

[0065] It should be noted that a socket or a plug may be provided at the downstream end of the hydrogen supply line HL4, and a plug or a socket may be provided at the upstream end of the hydrogen supply line HL.

[0066] As a result, when the hydrogen supply line HL4 and the hydrogen supply line HL are disconnected, inserting a plug into the socket will connect the hydrogen supply line HL4 and the hydrogen supply line HL.

[0067] Furthermore, when the hydrogen supply line HL4 and the hydrogen supply line HL are connected, removing the plug inserted into the socket will release the connection between the hydrogen supply line HL4 and the hydrogen supply line HL.

[0068] In the first embodiment, a gas blocking coupler that blocks gas from being ejected when the connection is released (when the plug is removed from the socket) is used as the connection part CP.

[0069] Therefore, even when the connection is released, hydrogen does not leak from the position of the connection part CP.

[0070] However, if the coupler is not a gas-blocking type that blocks the gas from being ejected, a sealing plug may be provided, for example, when the connection is released.

[0071] (50 hydrogen tanks) The hydrogen tank 50 is a cylindrical tank for storing hydrogen to be supplied to the power source 41 .

[0072] Since it is necessary to store as much hydrogen as possible in the hydrogen tank 50, the hydrogen is filled and stored under high pressure. Therefore, the hydrogen tank 50 is a hydrogen tank that can store hydrogen at high pressure. For example, it is preferable to use a lightweight hydrogen tank made of carbon fiber reinforced plastic and glass fiber reinforced plastic as the hydrogen tank 50.

[0073] In the first embodiment, as shown in FIG. 3, the hydrogen tank 50 is arranged inside the housing CS so that the length direction of the hydrogen tank 50 faces in the left-right direction perpendicular to the front-to-rear direction of the upper rotating body 20.

[0074] (Confluence valve 51) The junction valve 51 is a mechanism for merging hydrogen from each hydrogen tank 50, and may be configured as a multi-branch pipe. In the first embodiment, the hydrogen supplied from each of the multiple hydrogen supply lines HL1 and HL2 is joined by a single joining valve 51, but this is not limited to this, and the hydrogen tank unit HTU may be configured so that the hydrogen supplied from each of the multiple hydrogen supply lines HL1 and HL2 is joined by a plurality of joining valves 51. Alternatively, the hydrogen tank unit HT may be configured so that the junction valve 51 is not provided, and the hydrogen supply lines HL1 and HL2 are directly connected to each other.

[0075] (Hydrogen filling port 52) The hydrogen filling port 52 is a receptacle that receives the nozzle of a hydrogen dispenser installed at a hydrogen filling station.

[0076] The hydrogen supplied from the hydrogen dispenser to the hydrogen filling port 52 is then supplied to the junction valve 51 via a hydrogen supply line HL2 that supplies hydrogen from the hydrogen filling port 52 to the junction valve 51.

[0077] The hydrogen supplied to the junction valve 51 is supplied to each hydrogen tank 50 through a hydrogen supply line HL1 connecting the junction valve 51 to each hydrogen tank 50, and the hydrogen is filled into the hydrogen tank 50.

[0078] (Reducing valve 53) The pressure reducing valve 53 is a regulator that reduces the pressure of hydrogen supplied from the hydrogen tank 50 upstream of the pressure reducing valve 53 via the junction valve 51 through the hydrogen supply line HL3 to the pressure used in the hydrogen fuel cell 41A located downstream of the pressure reducing valve 53.

[0079] The hydrogen is then decompressed by the pressure reducing valve 53 and supplied to the power source 41 side through the hydrogen supply line HL4.

[0080] In addition, since hydrogen that has been depressurized by the pressure reducing valve 53 flows through the hydrogen supply line HL4, hydrogen at high pressure does not flow. Therefore, the gas pipe forming the hydrogen supply line HL4 does not need to have high pressure resistance.

[0081] For this reason, it is possible to use flexible gas piping (for example, a hose compatible with hydrogen gas) that is pliable and can be bent freely for the gas piping that forms the hydrogen supply line HL4, which makes it easier to handle.

[0082] As shown in FIGS. 1 to 3, the hydrogen tank unit HTU has a rear portion (see range B) located on the counterweight 23.

[0083] As shown in Figures 1 to 3, the counterweights 23 are provided in pairs in the left-right direction perpendicular to the fore-and-aft direction of the upper rotating body 20, and are provided with a hanging portion 23A on the upper surface of the counterweight 23 at a position that avoids the rear portion (see range B) of the hydrogen tank unit HTU and allows access from above without being obstructed (interfered with) by the rear portion (see range B) of the hydrogen tank unit HTU. The suspending portion 23A is configured with a metal fitting having a loop to which a wire rope or the like can be connected.

[0084] As can be seen from Figure 3, a hydrogen tank 50 that is shorter in length than the hydrogen tanks 50 located outside the rear portion (see range B) of the hydrogen tank unit HTU is located in the rear portion (see range B). In more detail, the short hydrogen tank 50 is positioned so that one end of the short hydrogen tank 50 in the longitudinal direction and the other end opposite the one end are spaced apart from the left and right edges, respectively, of the main body of the upper rotating body 20 (see range A in Figures 1 and 3). Therefore, spaces where no hydrogen tank 50 is disposed are secured to the left and right of the short hydrogen tank 50 . The pair of left and right hanging portions 23A are provided on the upper surface of the counterweight 23 so as to be located in the space where the hydrogen tank 50 is not placed.

[0085] However, whether or not to install a hydrogen tank 50 in the rear portion (see range B) of the hydrogen tank unit HTU that is shorter in length than the hydrogen tanks 50 installed elsewhere in the rear portion (see range B) is determined based on the size of the rear portion (see range B) of the hydrogen tank unit HTU.

[0086] Therefore, the length of the hydrogen tank 50 provided in the rear portion (see range B) of the hydrogen tank unit HTU is not limited to being shorter than the length of the hydrogen tank 50 provided in a location other than the rear portion (see range B).

[0087] FIG. 5 is a diagram illustrating the work of attaching and detaching the counterweight 23 of the first embodiment according to the present invention to and from the upper rotating body 20, and corresponds to FIG.

[0088] For example, as shown in FIG. 5, a pair of left and right suspension bolts HB1 of a hoisting balance HB and a pair of left and right suspension parts 23A of a counterweight 23 are connected by wire ropes or the like.

[0089] A wire rope or the like connected to a crane or the like is connected to a hanging bolt HB2 provided at the center of the hanging balance HB and on the opposite side of the pair of hanging bolts HB1, to prevent the counterweight 23 from falling off the upper rotating body 20.

[0090] The counterweight 23 in the first embodiment extends rearward from the main body of the upper rotating body 20 (see Figures 1 and range A in Figure 3), is supported by a support part (not shown) that receives the lower part of the counterweight 23, and is attached to the upper rotating body 20 by being bolted to the rear side of the machine room 22.

[0091] Therefore, first, the bolts (not shown) that fasten the counterweight 23 to the rear side of the machine room 22 are removed, and then the hoisting balance HB is pulled slightly upward (for example, by a few mm) to place the counterweight 23 in a spaced-apart state in which it is spaced upward from the support part (not shown).While maintaining this spaced state, the hoisting balance HB is moved toward the rear side of the upper rotating body 20, and the counterweight 23 is removed by moving it rearward together with the hoisting balance HB.

[0092] The work of attaching the counterweight 23 to the upper rotating body 20 is simply the reverse of the removal work, so a description thereof will be omitted.

[0093] In this way, in the first embodiment, the hydrogen tank 50 is not positioned as part of the counterweight 23, but is positioned by utilizing the space above the counterweight 23, and further, the hanging portion 23A of the counterweight 23 is provided in a position that avoids the rear part (see range B) of the hydrogen tank unit HTU in which the hydrogen tank 50 is positioned, so that it can be accessed from above.

[0094] Therefore, as described above, when attaching or detaching the counterweight 23 to the rear side of the main body of the upper rotating body 20 (see range A in Figures 1 and 3), there is no need to disconnect the hydrogen supply line, etc.

[0095] <<Second embodiment>> Next, a working machine 1 according to a second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a diagram for explaining a work machine 1 according to a second embodiment of the present invention, and corresponds to FIG.

[0096] The basic configuration of the work machine 1 of the second embodiment is similar to that of the first embodiment, and the following mainly describes the differences from the first embodiment, and explanations of the similarities with the first embodiment may be omitted.

[0097] As shown in FIG. 6, in the second embodiment, a gap C is provided between the underside of the rear part (see range B) of the hydrogen tank unit HTU and the upper surface of the counterweight 23 in consideration of workability.

[0098] As explained in the first embodiment, when the bolts (not shown) that secure the counterweight 23 to the rear side of the machine room 22 are removed, the lower part of the counterweight 23 is simply supported by a support part that extends rearward from the main body of the upper rotating body 20 (see range A in Figures 1 and 3).

[0099] Therefore, by sliding the counterweight 23 rearward in a state in which the counterweight 23 is spaced upward from a support portion (not shown), the counterweight 23 can be removed from the upper rotating body 20. In addition, the lifting of the counterweight 23 by the lifting balance HB, which is necessary to place the counterweight 23 in the separated state, is sufficient if it is lifted upward by only a few millimeters.

[0100] However, as in the second embodiment, if a gap C is provided between the underside of the rear part (see range B) of the hydrogen tank unit HTU and the upper surface of the counterweight 23, it is possible to effectively prevent the upper surface of the counterweight 23 from hitting the underside of the rear part (see range B) of the hydrogen tank unit HTU when the counterweight 23 is lifted by the lifting balance HB.

[0101] Therefore, the workability when removing the counterweight 23 from the work machine 1 can be improved.

[0102] <<Third Embodiment>> Next, a working machine 1 according to a third embodiment of the present invention will be described with reference to FIG. FIG. 7 is a diagram for explaining a work machine 1 according to a third embodiment of the present invention, and corresponds to FIG.

[0103] The basic configuration of the work machine 1 of the third embodiment is similar to that of the first embodiment, and the following mainly describes the differences from the first embodiment, and explanations of the similarities with the first embodiment may be omitted.

[0104] As shown in Figure 7, in the third embodiment, the upper rotating body 20 is provided on the main body (see range A) so as to be positioned between the rear part (see range B) of the hydrogen tank unit HTU and the counterweight 23, and is equipped with a protective part 24 that prevents the counterweight 23 from directly colliding with the rear part (see range B).

[0105] For example, the protective part 24 includes a metal plate 24A (e.g., a stainless steel plate) arranged between the rear part of the hydrogen tank unit HTU (see range B) and the counterweight 23, a pair of first mounting legs 24B provided on the front side of the metal plate 24A and extending from the metal plate 24A so as to be fixed to the left and right side walls inside the machine room 22, and a second mounting leg 24C extending from the metal plate 24A so as to be fixed to the rear side wall inside the machine room 22.

[0106] It should be noted that the attachment of the metal plate 24A does not have to be limited to the first attachment leg 24B and the second attachment leg 24C as described above, but rather the metal plate 24A needs to be fixed to the machine room 22, etc., firmly enough to avoid the counterweight 23 directly colliding with the rear part of the hydrogen tank unit HTU (see range B) when attaching or detaching the counterweight 23.

[0107] Furthermore, in the third embodiment, even if the counterweight 23 is lifted too high during installation or removal, the rear part of the hydrogen tank unit HTU (see range B) is protected by the protective part 24, so it is possible to avoid the counterweight 23 directly colliding with the rear part of the hydrogen tank unit HTU (see range B).

[0108] <<Fourth Embodiment>> Next, a working machine 1 according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 8 is a diagram for explaining a work machine 1 according to a fourth embodiment of the present invention, and corresponds to FIG.

[0109] In Figure 8, the hydrogen supply line HL1 connecting the multiple hydrogen tanks 50 and the junction valves 51 appears to be one line, but the hydrogen tanks 50 and the junction valves 51 are actually connected to each other by hydrogen supply lines HL1 that are spaced apart toward the back of the page, and they only appear to overlap because Figure 8 is a top view from above.

[0110] The basic configuration of the work machine 1 of the fourth embodiment is similar to that of the first embodiment, and the following mainly describes the differences from the first embodiment, and explanations of the similarities with the first embodiment may be omitted.

[0111] As shown in FIG. 8, in the fourth embodiment, a plurality of rear portions (see range B) of the hydrogen tank units HTU are provided spaced apart in the left-right direction of the upper swing structure 20.

[0112] The counterweight 23 is provided in a pair in the left-right direction perpendicular to the fore-and-aft direction of the upper rotating body 20, and is located between the rear part (see range B) of the hydrogen tank unit HTU, avoiding the rear part (see range B) of the hydrogen tank unit HTU, which can be accessed from above without being obstructed (interfered with), and is provided with a pair of left and right hanging parts 23A at the position on the upper surface of the counterweight 23.

[0113] Each hydrogen tank 50 is arranged inside the housing CS so that the length direction of the hydrogen tank 50 faces in the front-to-rear direction of the upper rotating body 20.

[0114] In addition, three long hydrogen tanks 50 are arranged in the rear part of the hydrogen tank unit HTU (see range B). One of the long hydrogen tanks 50 is located in the center of the main body (see range A) in the left-right direction, and the remaining two are located at one end and the other end of the main body (see range A) in the left-right direction. Furthermore, two short hydrogen tanks 50 are provided between the long hydrogen tanks 50, in a location where the rear portion of the hydrogen tank unit HTU (see range B) is not provided.

[0115] Specifically, short hydrogen tanks 50 are provided so as to be spaced apart from the rear edge of the counterweight 23 between the long hydrogen tank 50 located in the left-right center of the main body portion (see range A) and the long hydrogen tank 50 located at one left-right end of the main body portion (see range A), and between the long hydrogen tank 50 located in the left-right center of the main body portion (see range A) and the long hydrogen tank 50 located at the other left-right end of the main body portion (see range A). Therefore, a space where no hydrogen tank 50 is disposed is secured behind each of the two short hydrogen tanks 50. The pair of left and right hanging portions 23A are provided on the upper surface of the counterweight 23 so as to be located in the space where the hydrogen tank 50 is not placed.

[0116] As described above, in the first to fourth embodiments, in order to make effective use of space and to arrange many hydrogen tanks 50, the hydrogen tank unit HTU has a rear portion (see range B) located on the counterweight 23, and the counterweight 23 is provided in pairs in the left-right direction perpendicular to the fore-and-aft direction of the upper rotating body 20, and has a hanging portion 23A located on the upper surface of the counterweight 23 avoiding the rear portion (see range B) of the hydrogen tank unit HTU, which can be accessed from above without being obstructed (interfered with) by the rear portion (see range B) of the hydrogen tank unit HTU.

[0117] Therefore, when attaching or detaching the counterweight 23 to or from the rear side of the main body of the upper rotating body 20 (see range A in FIGS. 1 and 3), there is no need to disconnect the hydrogen supply line.

[0118] Although the present invention has been described above based on specific embodiments, the present invention is not limited to the above embodiments.

[0119] For example, the number of suspending portions 23A provided on the counterweight 23 does not need to be limited to two as shown in the first to fourth embodiments, and may be three or more.

[0120] However, if the number of hanging parts 23A increases, it becomes difficult to find a position where the hanging parts 23A and the rear part of the hydrogen tank unit HTU (see range B) do not interfere with each other, so from this point of view, the fewer the number, the better. Also, taking into consideration the need to stably support the hanging balance HB, two hanging parts 23A are preferable.

[0121] As described above, the present invention also includes modifications and improvements to the above-described embodiments within the technical scope of the invention, and this will be apparent to those skilled in the art from the description of the claims. [Explanation of symbols]

[0122] 1 working machine, 10 undercarriage, 11 frame, 11A central frame, 11B crawler frame, 12 traveling mechanism, 20 upper rotating body, 21 operator's cab, 22 machine room, 23 counterweight, 23A lifting section, 30 working mechanism, 31 boom, 32 arm, 33 attachment, 31A boom cylinder, 32A arm cylinder, 33A attachment cylinder, 40 drive system, 4 1 Power source, 41A Hydrogen fuel cell, 41B Electric motor, 42 Operating pump, 42A Hydraulic oil tank, 43 Control valve, 44 Drive unit, 44A Swing motor, 44B Working mechanism cylinder, 44C Travel motor, 50 Hydrogen tank, 51 Merging valve, 52 Hydrogen filling port, 53 Pressure reducing valve, CP Connection part, CS Housing, HL, HL1, HL2, HL3, HL4 Hydrogen supply line, HTU Hydrogen tank unit

Claims

1. A work machine, The work machine includes: a lower running body; an upper rotating body that is rotatably provided with respect to the lower traveling body, The upper rotating body is a main body; a hydrogen-fueled power source provided within the main body; a counterweight detachably provided on the rear side of the main body; a hydrogen tank unit provided on the main body and supplying the hydrogen to the power source, the hydrogen tank unit has a rear portion positioned on the counterweight, The counterweight has a hanging part at a position that avoids the rear part, which is accessible from above.

2. 2. The work machine according to claim 1, wherein a gap is provided between the lower surface of the rear portion and the upper surface of the counterweight.

3. 3. The work machine according to claim 1 or 2, wherein the upper rotating body is provided on the main body portion so as to be positioned between the rear portion and the counterweight, and includes a protection portion that prevents the counterweight from directly colliding with the rear portion.

Images