Electric work machine

Abstract

The invention provides an electric work machine which can efficiently cool equipment in a machine body, and can provide a battery cell as large as possible in a limited space in the machine body, thereby increasing the battery capacity. A hydraulic shovel, which is an electric working machine, is provided with, in a machine body: a battery unit for storing electric power; an electric motor driven by receiving power from the battery unit; a hydraulic pump driven by the electric motor; an oil cooler that cools the hydraulic oil discharged from the hydraulic pump; and the fan is used for obtaining air into the machine body. The machine body is provided with a first opening part and a second opening part, the first opening part is arranged on one side of the machine body, and the second opening part is arranged on the other side of the machine body. The fan is arranged opposite to the first opening part in the machine body, and the oil cooler is arranged opposite to the second opening part in the machine body.

Description

Technical Field

[0001] The present invention relates to an electric working machine. Background Art

[0002] As a conventional technology, an electric construction machine including a battery unit inside the machine body is known (for example, refer to Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2022-97079

[0004] In a small electric working machine, it is desirable to install a large battery unit in a limited space inside the machine body, increase the battery capacity, and extend the operating time. In addition, it is also desirable to efficiently cool the equipment inside the machine body (including the battery unit). In Patent Document 1, consideration is given to ensuring a larger configuration space for the battery unit, but no consideration is given to efficiently cooling the equipment inside the machine body. In this regard, the electric construction machine of Patent Document 1 has room for improvement. Summary of the invention

[0005] The present invention is completed to solve the above-mentioned problems, and its purpose is to provide an electric working machine that can efficiently cool the equipment inside the machine body and set a battery unit as large as possible in the limited space inside the machine body to increase the battery capacity.

[0006] An electric working machine involved in one aspect of the present invention comprises in a machine body: a battery unit for storing electricity; an electric motor for being driven by receiving the electricity supplied from the battery unit; a hydraulic pump driven by the electric motor; an oil cooler for cooling the working oil discharged from the hydraulic pump; and a fan for taking air into the machine body, the machine body having a first opening and a second opening, the first opening being arranged on one side of the machine body, and the second opening being arranged on the other side of the machine body, the fan being arranged in the machine body opposite to the first opening, and the oil cooler being arranged in the machine body opposite to the second opening.

[0007] According to the above structure, the equipment inside the body can be cooled efficiently, and a battery unit as large as possible can be arranged in a limited space inside the body to increase the battery capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a left side view showing a schematic structure of a hydraulic excavator as an example of an electric working machine according to an embodiment of the present invention.

[0009] Figure 2 It is a right side view of the hydraulic excavator.

[0010] Figure 3 It is a block diagram schematically showing the configuration of the electrical system and the hydraulic system of the hydraulic excavator.

[0011] Figure 4 It is a plan view showing the internal structure of the engine room of the hydraulic excavator in a first arrangement example.

[0012] Figure 5 It is a rear view showing the internal structure of the first arrangement example of the engine room.

[0013] Figure 6 It is a left side view showing the internal structure of the first arrangement example of the engine room.

[0014] Figure 7 It is a left side view of the hydraulic excavator in which the internal structure of the engine room is a second arrangement example.

[0015] Figure 8 It is a right side view of the hydraulic excavator.

[0016] Fig. 9 It is a plan view showing the internal structure of the second arrangement example of the engine room.

[0017] Fig.10 It is a rear view showing the internal structure of the second arrangement example of the engine room.

[0018] Fig.11 It is a left side view showing the internal structure of the second arrangement example of the engine room.

[0019] Description of Reference Numerals

[0020] 1…hydraulic excavator (electric working machine); 4…upper rotating body (machine body); 44L1…first opening; 44R1…second opening; 44R2…third opening; 45…fan; 46…oil cooler; 61…hydraulic pump; 62…control valve; 63…hydraulic actuator; 64…working oil tank; BU…battery unit; BU1…front; EM…electric motor; EQ…electric equipment; EQ1…first electrical equipment; EQ2…second electrical equipment; EQ3…third electrical equipment; EQ4…fourth electrical equipment. DETAILED DESCRIPTION

[0021] Embodiments of the present invention are described below based on the drawings.

[0022] 〔1. Electric working machinery〕

[0023] Figure 1It is a left side view showing a schematic structure of a hydraulic excavator 1 (electric excavator) as an example of an electric working machine according to an embodiment of the present invention. Figure 2 It is a right side view of the hydraulic excavator 1. The hydraulic excavator 1 includes a lower traveling body 2, a working machine 3, and an upper swing body 4 (also referred to as a machine body). In this embodiment, the internal structure of the upper swing body 4 (particularly the engine room 44 described later) is described based on two examples (a first configuration example and a second configuration example). Hereinafter, the case where the internal structure of the upper swing body 4 (engine room 44) is the first configuration example is described.

[0024] Here, the directions are defined as follows. The direction in which the operator (operator, driver) sitting on the driver's seat 43a of the operating unit 43 disposed on the upper rotating body 4 faces in the front direction is referred to as "front", and the opposite direction is referred to as "rear". When the upper rotating body 4 is not rotated relative to the lower traveling body 2 (the rotation angle is 0 degrees), the front-to-back direction of the upper rotating body 4 is consistent with the front-to-back direction of the lower traveling body 2. In the accompanying drawings, the hydraulic excavator 1 is shown in a state in which the upper rotating body 4 is not rotated relative to the lower traveling body 2. In addition, as viewed from the operator sitting on the driver's seat 43a, the left side is referred to as "left", and the right side is referred to as "right". In addition, the gravity direction perpendicular to the front-to-back direction and the left-to-right direction is referred to as the up-down direction, the upstream side of the gravity direction is referred to as "up", and the downstream side is referred to as "down". In the drawings, as necessary, the front is indicated by an “F” symbol, the rear is indicated by a “B” symbol, the right is indicated by an “R” symbol, the left is indicated by an “L” symbol, the top is indicated by a “U” symbol, and the bottom is indicated by a “D” symbol.

[0025] The lower traveling body 2 includes a pair of left and right crawlers 21, a pair of left and right travel motors 22, and a bulldozer 23. The left and right travel motors 22 drive the left and right crawlers 21, respectively, so that the hydraulic excavator 1 can move forward and backward. The travel motor 22 is composed of a hydraulic motor. The bulldozer 23 for leveling the ground is provided on the front side of the lower traveling body 2. The bulldozer 23 is rotated by a bulldozer cylinder 23a. The bulldozer cylinder 23a is composed of a hydraulic cylinder.

[0026] The working machine 3 includes a boom 31, an arm 32, and a bucket 33. By independently driving the boom 31, the arm 32, and the bucket 33, excavation work of soil and sand can be performed.

[0027] The boom 31 is rotated by the boom cylinder 31a. The boom cylinder 31a is configured so that the base end is supported by the front part of the upper revolving body 4 and is movable in a telescopic manner. In the accompanying drawings, the boom cylinder 31a is configured so that the rod side becomes the base end, but it can also be configured so that the tube side becomes the base end. The boom 32 is rotated by the boom cylinder 32a. The boom cylinder 32a is configured so that the base end is supported by the boom 31 and is movable in a telescopic manner. The bucket 33 is rotated by the bucket cylinder 33a. The bucket cylinder 33a is configured so that the base end is supported by the boom 32 and is movable in a telescopic manner. The boom cylinder 31a, the boom cylinder 32a and the bucket cylinder 33a are respectively composed of hydraulic cylinders.

[0028] The base end of the boom 31 is swingably connected to a front end 41a of a revolving frame 41 described later via a bracket (not shown). That is, the hydraulic excavator 1 of this embodiment has a boom swing function in which the boom 31 swings left and right starting from the front end 41a.

[0029] The upper revolving body 4 is located above the lower traveling body 2 and is rotatably provided relative to the lower traveling body 2 via a revolving bearing (not shown). The upper revolving body 4 includes a revolving frame 41, a revolving motor 42, a control unit 43, and an engine room 44. The upper revolving body 4 is driven by the revolving motor 42 disposed on the revolving frame 41 to revolve relative to the lower traveling body 2. The revolving frame 41 is composed of a plurality of metal parts connected by welding or the like. The revolving motor 42 is composed of a hydraulic motor.

[0030] The engine room 44 is provided with a left engine hood 44L and a right engine hood 44R which serve as left and right side walls. The left engine hood 44L is located on the left side (one side) of the engine room 44, and the right engine hood 44R is located on the right side (the other side) of the engine room 44. The left engine hood 44L and the right engine hood 44R are respectively fixed to the revolving frame 41 via support members (not shown). The first opening 44L1 of the left engine hood 44L and the second opening 44R1 and the third opening 44R2 of the right engine hood 44R will be described later.

[0031] The battery unit BU and the fan 45 are housed in the engine room 44. That is, the hydraulic excavator 1 includes the battery unit BU and the fan 45 in the machine body. The battery unit BU is composed of, for example, a lithium-ion battery, and stores a charge for driving the electric motor EM (see Figure 3 ) of power. The battery unit BU may be composed of a plurality of battery units or a single battery cell. In addition, a power supply port (not shown) is provided on the upper rotating body 4. By connecting the power supply port to an external power source (not shown), the battery unit BU can be charged.

[0032] The fan 45 is composed of an electric fan, and takes air (external air) into the engine room 44. That is, the fan 45 takes air into the body. Thus, a flow of wind is formed in the engine room 44. The fan 45 includes a first fan 45a and a second fan 45b. The first fan 45a is located above the second fan 45b. That is, a plurality of fans 45 are arranged in an up-down direction.

[0033] The engine room 44 also contains a hydraulic pump 61 (see Figure 3 ) and an oil cooler 46. That is, the hydraulic excavator 1 includes a hydraulic pump 61 and an oil cooler 46 in the machine body. The hydraulic pump 61 is driven by the electric motor EM and supplies hydraulic oil (pressure oil) to the hydraulic motors (e.g., the left and right travel motors 22 and the swing motor 42) and the hydraulic cylinders (e.g., the bulldozer cylinder 23a, the boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33a). The hydraulic motors and hydraulic cylinders that are driven by the hydraulic oil supplied from the hydraulic pump 61 are collectively referred to as hydraulic actuators 63 (see Figure 3 ).

[0034] The oil cooler 46 is connected to an oil passage through which the hydraulic oil discharged from the hydraulic pump 61 circulates (see Figure 3 ). In the above oil circuit, the working oil heated by the driving of the hydraulic actuator 63 flows into the oil cooler 46 via the control valve 62. The oil cooler 46 is composed of a heat exchanger that cools the working oil by exchanging heat with wind (air) blown to the oil cooler 46. That is, the oil cooler 46 cools the working oil discharged from the hydraulic pump 61 and heated by the driving of the hydraulic actuator 63.

[0035] The operating unit 43 is provided at the upper part of the upper revolving body 4. A driver's seat 43a is provided at the operating unit 43. A plurality of operating components 43b are provided around the driver's seat 43a. The plurality of operating components 43b are configured to include a lever, a switch, a pedal, etc. An operator sits on the driver's seat 43a and operates the plurality of operating components 43b to drive the hydraulic actuator 63. Thus, the lower traveling body 2 can be driven, the ground leveling operation can be performed using the bulldozer 23, the excavation operation can be performed using the working machine 3, the upper revolving body 4 can be rotated, etc.

[0036] The hydraulic excavator 1 may be configured to use both the hydraulic actuator 63 and an electric actuator driven by electricity as actuators. The electric actuator includes, for example, an electric travel motor, an electric swing motor, and an electric cylinder.

[0037] 〔2. Structure of electrical system and hydraulic system〕

[0038] Figure 3 1 is a block diagram schematically showing the configuration of the electrical system and the hydraulic system of the hydraulic excavator 1. Figure 3In the figure, the solid lines represent the wiring through which the electric signal or current flows, and the dotted lines represent the oil path through which the hydraulic oil flows. The hydraulic excavator 1 includes an electric motor EM, a charger 51, an inverter 52, a PDU (Power Drive Unit) 53, a junction box 54, a DC-DC converter 55, a lead battery 56, and a system controller 57. The charger 51, the inverter 52, the PDU 53, the junction box 54, the DC-DC converter 55, and the lead battery 56 are collectively referred to as electrical equipment EQ. The electrical equipment EQ is housed in the engine room 44 (see Figure 4 ).

[0039] The electric device EQ is directly connected to the battery unit BU or electrically connected to the battery unit BU via other electric devices. For example, the PDU 53 as the electric device EQ is directly connected to the battery unit BU. In addition, the inverter 52 as the electric device EQ is electrically connected to the battery unit BU via the junction box 54 as the other electric device EQ.

[0040] The electric motor EM is driven by electric power supplied from the battery unit BU via the junction box 54 and the inverter 52. The electric motor EM is composed of a synchronous motor or an induction motor, etc. The electric motor EM is accommodated in the engine room 44. That is, the hydraulic excavator 1 includes the electric motor EM driven by receiving electric power supplied from the battery unit BU in the machine body.

[0041] The charger 51 (also referred to as a power supply) converts the AC voltage supplied from the external power supply into a DC voltage. The inverter 52 converts the DC voltage supplied from the battery unit BU into an AC voltage and supplies it to the electric motor EM. As a result, the electric motor EM is driven. The supply of the AC voltage from the inverter 52 to the electric motor EM is performed based on the rotation command output from the system controller 57.

[0042] The PDU 53 is a battery control unit that controls the internal battery relay to control the input and output of the battery unit BU. The junction box 54 is configured to include a charger relay, an inverter relay, a fuse, etc. The voltage output from the charger 51 is supplied to the battery unit BU via the junction box 54 and the PDU 53. In addition, the voltage output from the battery unit BU is supplied to the inverter 52 via the PDU 53 and the junction box 54.

[0043] The DC-DC converter 55 steps down the high voltage (e.g., 300 V) DC voltage supplied from the battery unit BU via the junction box 54 to a low voltage (e.g., 12 V). The lead battery 56 outputs a low voltage DC voltage. The low voltage DC voltage output from the DC-DC converter 55 and the lead battery 56 is supplied to the drive unit of the fan 45 (the first fan 45a and the second fan 45b), the system controller 57, and the like. In the present embodiment, a plurality of DC-DC converters 55 are provided (see Figure 4 ), but it may be one. The system controller 57 is composed of an electronic control unit called an ECU (Electronic Control Unit). The system controller 57 electrically controls each part of the hydraulic excavator 1.

[0044] The plurality of hydraulic pumps 61 are connected to the rotating shaft (output shaft) of the electric motor EM. The plurality of hydraulic pumps 61 include a variable displacement pump and a fixed displacement pump. Figure 3 In the figure, only one hydraulic pump 61 is shown as an example. Each hydraulic pump 61 is connected to a working oil tank 64 storing working oil. When the hydraulic pump 61 is driven by the electric motor EM, the working oil in the working oil tank 64 is supplied to the hydraulic actuator 63 via the control valve 62. As a result, the hydraulic actuator 63 is driven. That is, the hydraulic actuator 63 is driven by the supply of working oil from the hydraulic pump 61. The control valve 62 is a direction switching valve that controls the flow direction and flow rate of the working oil supplied from the hydraulic pump 61 to the hydraulic actuator 63.

[0045] The hydraulic oil discharged from the hydraulic actuator 63 flows into the hydraulic oil tank 64 via the control valve 62 and the oil cooler 46. Therefore, the hydraulic oil generated by the driving of the hydraulic actuator 63 is cooled by the oil cooler 46 and then flows into the hydraulic oil tank 64. In this way, the hydraulic excavator 1 includes the oil cooler 46, the control valve 62, the hydraulic actuator 63, and the hydraulic oil tank 64.

[0046] 〔3.Internal structure of the engine room〕

[0047] based on Figure 4 , Figure 5 as well as Figure 6 The arrangement of each device (for example, the fan 45 , the oil cooler 46 , the battery unit BU, etc.) in the engine room 44 will be described. Figure 4 , Figure 5 as well as Figure 6 4 is a top view, a rear view, and a left side view showing the internal structure of the engine room 44. The various devices arranged in the engine room 44 are supported on the revolving frame 41 via support members such as pillars, but Figures 4 to 6 In order to make the configuration position of each device clear, the supporting components are omitted. Figure 4 and Figure 5 , in order to clarify the arrangement position of the fan 45 relative to the first opening 44L1, the left engine hood 44L is shown cut in the horizontal direction and the vertical direction at the position of the first opening 44L1. Similarly, in order to clarify the arrangement position of the oil cooler 46 relative to the second opening 44R1, the right engine hood 44R is shown cut in the horizontal direction and the vertical direction at the position of the second opening 44R1.

[0048] like Figure 4 and Figure 5 As shown, the left engine hood 44L is located on the left side (one side) of the engine room 44. A first opening portion 44L1 is provided on the left engine hood 44L, which is extended in the left-right direction. Two first opening portions 44L1 are provided corresponding to the first fan 45a and the second fan 45b. The right engine hood 44R is located on the right side (the other side) of the engine room 44. A second opening portion 44R1 and a third opening portion 44R2 are provided on the right engine hood 44R, which are extended in the left-right direction. That is, the machine body (especially the engine room 44 of the upper rotating body 4) has a first opening portion 44L1 provided on one side of the machine body and a second opening portion 44R1 provided on the other side of the machine body.

[0049] The third opening 44R2 is located forward of the second opening 44R1. When the engine room 44 is viewed from the right, the third opening 44R2 is provided at a position overlapping with the front portion BU1 of the battery unit BU. The front portion BU1 of the battery unit BU refers to a portion including the frontmost portion of the battery unit BU. The range of the front portion BU1 in the front-to-back direction is not particularly limited, and may be appropriately set within a range forward of the center in the front-to-back direction of the battery unit BU.

[0050] In the present embodiment, the entire third opening 44R2 is provided so as to overlap with the front portion BU1 of the battery unit BU, but the structure of the third opening 44R2 is not limited to the above structure. For example, only the rear portion of the third opening 44R2 may be provided so as to overlap with the front portion BU1. In this way, the body has the third opening 44R2 provided on the other side and located in front of the second opening 44R1. Moreover, when viewed from the side, at least a portion of the third opening 44R2 is located at a position overlapping with the front portion BU1 of the battery unit BU.

[0051] The fan 45 (the first fan 45a and the second fan 45b) is arranged at a position opposite to the first opening 44L1, on the inner side (i.e., the right side) of the engine room 44. The oil cooler 46 is arranged at a position opposite to the second opening 44R1, on the inner side (i.e., the left side) of the engine room 44. That is, the fan 45 is arranged opposite to the first opening 44L1 in the body, and the oil cooler 46 is arranged opposite to the second opening 44R1 in the body.

[0052] When the engine room 44 is viewed from the rear, the battery unit BU is disposed between the fan 45 and the second opening 44R1 (right engine cover 44R). That is, when viewed from the rear, the battery unit BU is disposed between the fan 45 and the second opening 44R1. Three battery units BU are provided and arranged in a vertical direction.

[0053] An electric motor EM and a hydraulic oil tank 64 are arranged side by side below the battery unit BU. The electric motor EM is provided on the left side (one side) of the engine room 44, and the hydraulic oil tank 64 is provided on the right side (the other side) of the engine room 44.

[0054] An oil cooler 46 and a part of the electric equipment EQ (first electric equipment EQ1) are arranged behind the battery unit BU. The first electric equipment EQ1 includes a charger 51, an inverter 52, a DC-DC converter 55 and a lead battery 56. The inverter 52 and the DC-DC converter 55 are arranged to the right of the fan 45. The inverter 52 is located below the DC-DC converter 55. The charger 51 is arranged to the right of the inverter 52 and the DC-DC converter 55. The lead battery 56 is arranged below the charger 51 and offset to the left relative to the charger 51. The oil cooler 46 is located to the right of the charger 51. Therefore, the first electric equipment EQ1 is arranged between the fan 45 and the oil cooler 46 in the body.

[0055] like Figure 4 and Figure 6 As shown, the remaining part of the electric equipment EQ (second electric equipment EQ2) and the fan 45 are arranged on the left side of the battery unit BU. That is, the second electric equipment EQ2 and the fan 45 are arranged on the side of the battery unit BU. The second electric equipment EQ2 includes a PDU 53 and a junction box 54. The second electric equipment EQ2 is located in front of the fan 45. When the engine room 44 is viewed from the left, the fan 45 is arranged to protrude to the rear of the rear end of the battery unit BU. That is, when viewed from the side, a part of the fan 45 is located on the rear side of the body of the battery unit BU.

[0056] According to the above structure, if the fan 45 is driven, air is taken in (sucked in) into the machine body (especially the engine room 44 of the upper rotating body 4) through the first opening portion 44L1. The taken in air flows from the left side (one side) toward the right side (the other side) in the machine body and is discharged through the second opening portion 44R1. As a result, a flow of wind from the left side toward the right side is formed in the machine body. Then, the above wind is used to cool the various devices arranged in the machine body (for example, the oil cooler 46, the battery unit BU, the electric motor EM, the electrical equipment EQ, etc.). In addition, the above-mentioned taken in air is also discharged through the third opening portion 44R2, but the flow of wind toward the third opening portion 44R2 will be described later.

[0057] As described above, the oil cooler 46 is disposed opposite to the second opening 44R1. Therefore, the wind blows to the oil cooler 46 last among the devices disposed in the machine body. That is, the oil cooler 46 is cooled last among the devices in the machine body. Then, the wind (relatively high temperature wind) cooled by the relatively high temperature oil cooler 46 is directly discharged to the outside of the machine body from the second opening 44R1. Therefore, it is possible to avoid the relatively high temperature wind blowing to the battery unit BU, the electric motor EM and the electric device EQ in the machine body, and to discharge the relatively high temperature wind to the outside of the machine body. Therefore, it is possible to efficiently cool the various devices in the machine body. In addition, the fan 45 is disposed close to the left side of the machine body, and the oil cooler 46 is disposed close to the right side of the machine body. Thus, in the machine body, the configuration space of the battery unit BU can be ensured as large as possible in the left-right direction (the width direction of the machine body), and the remaining parts of the various devices mentioned above can be easily configured. Thus, it is possible to efficiently cool the various devices in the machine body, and to set the battery unit BU as large as possible in the limited space in the machine body, thereby increasing the battery capacity.

[0058] If the battery unit BU is disposed between the fan 45 and the second opening 44R1, it is easier to expand the arrangement space of the battery unit BU in the left-right direction than when the battery unit BU is disposed between the fan 45 and the oil cooler 46. That is, it is easier to expand the arrangement space of the battery unit BU in the left-right direction by at least the width of the oil cooler 46 in the left-right direction. From this viewpoint, it is preferable that the battery unit BU is disposed between the fan 45 and the second opening 44R1 when viewed from the back as in the present embodiment.

[0059] By arranging the first electrical equipment EQ1 (for example, the charger 51) between the fan 45 and the oil cooler 46, it is possible to prevent the wind (relatively high temperature wind) cooled by the relatively high temperature oil cooler 46 from blowing to the first electrical equipment EQ1. As a result, the first electrical equipment EQ1 and the oil cooler 46 in the machine body are efficiently cooled. Therefore, as in the present embodiment, in the hydraulic excavator 1, the electrical equipment EQ connected to the battery unit BU is provided, and in the structure where the electrical equipment EQ includes the first electrical equipment EQ1 located in the machine body at the rear side of the machine body relative to the battery unit BU, the first electrical equipment EQ1 is preferably arranged between the fan 45 and the oil cooler 46 in the machine body.

[0060] By arranging the electric motor EM and the hydraulic oil tank 64 in parallel below the battery unit BU, it is easy to ensure the arrangement space of the battery unit BU in the horizontal direction. Therefore, it is easy to provide a battery unit BU that is larger in the horizontal direction. Therefore, in a structure in which the hydraulic excavator 1 includes the hydraulic oil tank 64 in addition to the electric motor EM as in the present embodiment, it is preferable that the electric motor EM and the hydraulic oil tank 64 are arranged in parallel below the battery unit BU in the machine body.

[0061] The electric motor EM is arranged on the same side as the fan 45 (one side of the machine body), and the working oil tank 64 is arranged on the same side as the oil cooler 46 (the other side of the machine body). In this case, the electric motor EM is arranged on the upstream side of the wind flowing from the first opening 44L1 toward the second opening 44R1 below the battery unit BU, and the working oil tank 64 is arranged on the downstream side. In this configuration, the wind after cooling the electric motor EM blows to the working oil tank 64, cooling the working oil tank 64. Then, the wind after cooling the working oil tank 64 (relatively high temperature wind) is discharged to the outside of the machine body from the second opening 44R1. That is, it is avoided that the relatively high temperature wind blows to the electric motor EM. Therefore, the electric motor EM and the working oil tank 64 are efficiently cooled. From the above viewpoint, it is preferred that the electric motor EM is arranged on one side of the machine body, and the working oil tank 64 is arranged on the other side of the machine body.

[0062] By arranging a plurality of fans 45 (a first fan 45a and a second fan 45b) in the up-down direction, the range of the air flow in the machine body can be expanded in the up-down direction. Thus, it is possible to realize a layout in which the electrical equipment EQ that needs to be cooled is arranged in the up-down direction in the machine body, and the degree of freedom in the configuration of the electrical equipment EQ is improved. In addition, by arranging a plurality of fans 45 in the up-down direction, the diameter of each fan 45 becomes smaller compared to a structure in which one fan is arranged in the same range in the up-down direction. Thus, the first opening portion 44L1 opposite to the fan 45 is formed with the minimum required size, thereby avoiding a reduction in the strength of the machine body (especially the left engine hood 44L). From such a viewpoint, it is preferred that a plurality of fans 45 are arranged in the up-down direction as in the present embodiment.

[0063] By arranging the fan 45 on the side of the battery unit BU (on the left side in this embodiment), the wind flowing from the fan 45 is efficiently blown to the battery unit BU. As a result, the battery unit BU is efficiently cooled. From this point of view, it is preferable that the fan 45 is arranged on the side of the battery unit BU as in this embodiment.

[0064] If part of the wind from the fan 45 flows behind the battery unit BU, the first electric device EQ1 arranged behind the battery unit BU is efficiently cooled. From this point of view, it is preferable that part of the fan 45 is located behind the battery unit BU in the machine body in side view.

[0065] By arranging the oil cooler 46 behind the battery unit BU, it is easy to install a battery unit BU that is larger in the left-right direction. In addition, the wind flowing from the fan 45 is efficiently blown to the oil cooler 46 behind the battery unit BU. As a result, the cooling efficiency of the oil cooler 46 is improved. From such a viewpoint, it is preferable that the oil cooler 46 is arranged on the rear side of the machine body than the battery unit BU as in the present embodiment.

[0066] Here, based on Figure 4 The flow of wind toward the third opening 44R2 is described. The air taken into the engine room 44 from the first opening 44L1 by the fan 45 passes through the interior of the engine room 44, is discharged through the second opening 44R1, and is also discharged through the third opening 44R2. As described above, the third opening 44R2 is located in front of the second opening 44R1. Therefore, the air from the first opening 44L1 toward the third opening 44R2 flows from the left side to the right side in the body along the side of the battery unit BU (when a plurality of battery units BU are stacked, through the gap between the upper and lower battery units BU), and flows from the rear side to the front side. As a result, a flow of wind from the left side to the right side and from the rear side to the front side is formed in the body.

[0067] As described above, at least a portion of the third opening 44R2 is located at a position overlapping with the front portion BU1 of the battery unit BU when viewed from the side. In this case, the wind taken in from the first opening 44L1 flows through the vicinity of the front portion BU1 of the battery unit BU and is discharged from the third opening 44R2. Therefore, the wind can be blown to the front portion BU1 of the battery unit BU to cool the battery unit BU. Therefore, from the viewpoint of improving the cooling efficiency of the battery unit BU, it is preferable that the body has the third opening 44R2 provided on the other side and located forward of the second opening 44R1, and at least a portion of the third opening 44R2 is located at a position overlapping with the front portion BU1 of the battery unit BU when viewed from the side.

[0068] By arranging the second electrical device EQ2 (e.g., PDU53) in front of the fan 45 and on the side of the battery unit BU (on the left in this embodiment), the wind flowing from the fan 45 toward the third opening 44R2 is efficiently blown to the second electrical device EQ2 on the side of the battery unit BU. As a result, the second electrical device EQ2 is efficiently cooled. From the viewpoint of efficiently cooling the second electrical device EQ2 and effectively utilizing the free space on the side of the battery unit BU, it is preferred that the electrical device EQ includes the second electrical device EQ2 located on the front side of the body than the fan 45 in the body, as in this embodiment, and the second electrical device EQ2 is arranged on the side of the battery unit BU and on one side of the body.

[0069] [4. Other internal structures of the engine room]

[0070] A case where the internal structure of the engine room 44 is the second arrangement example will be described. Figure 7 and Figure 8 These are a left side view and a right side view of the hydraulic excavator 1 in the above-mentioned case. Fig. 9 , Fig.10 as well as Fig.11 1 and 2 are a top view, a rear view, and a left side view showing the internal structure of the engine room 44 in a second configuration example. Figures 9 to 11 In, with Figures 4 to 6 Similarly, in order to make the arrangement position of each device (for example, the fan 45, the oil cooler 46, the battery unit BU, etc.) clear, the illustration of supporting components such as pillars is omitted. Fig. 9 and Fig.10 In, with Figure 4 and Figure 5 Similarly, in order to clarify the arrangement position of the fan 45 relative to the first opening 44L1, the left engine cover 44L is shown cut in the horizontal direction and the vertical direction at the position of the first opening 44L1. Similarly, in order to clarify the arrangement position of the oil cooler 46 relative to the second opening 44R1, the right engine cover 44R is shown cut in the horizontal direction and the vertical direction at the position of the second opening 44R1.

[0071] like Figure 7 to Figure 11 As shown, the left engine hood 44L is provided with a first opening 44L1 extending in the left-right direction. A fan 45 is arranged in the engine room 44 at a position opposite to the first opening 44L1. Here, one fan 45 is arranged. The right engine hood 44R is provided with a second opening 44R1 extending in the left-right direction. An oil cooler 46 is arranged in the engine room 44 at a position opposite to the second opening 44R1. A battery unit BU and a third electric device EQ3 as a part of the electric device EQ are arranged between the fan 45 and the oil cooler 46. Four battery units BU are arranged in a row in the front-rear direction.

[0072] The third electrical equipment EQ3 includes a charger 51, an inverter 52, a PDU 53, and a DC-DC converter 55. The inverter 52 is arranged on the right side of the fan 45. The PDU 53 is arranged on the right side of the inverter 52. The charger 51 is arranged in front of the PDU 53. The charger 51, the inverter 52, and the PDU 53 are located above the battery unit BU. The DC-DC converter 55 is arranged behind the PDU 53 and on the rear side of the battery unit BU. The oil cooler 46 is located on the right side of the charger 51, the PDU 53, and the DC-DC converter 55. In more detail, the oil cooler 46 is located on the right side of the battery unit BU.

[0073] The space below the floor portion 43c provided in front of the battery unit BU and below the operating unit 43 is included in the interior of the engine room 44. The hydraulic oil tank 64 is accommodated in the above space. That is, the hydraulic oil tank 64 is arranged in the body on the front side of the body than the battery unit BU. In addition, when viewed from the rear side of the body, the hydraulic oil tank 64 is located at a position offset to the left relative to the battery unit BU.

[0074] A support portion 43b1 of the operating member 43b extending upward from the floor portion 43c is provided on the front side of the floor portion 43c. Parts of a plurality of operating members 43b are provided on the support portion 43b1. The control valve 62 is accommodated in the support portion 43b1. Therefore, the control valve 62 is located above the hydraulic oil tank 64.

[0075] The remaining part of the electric device EQ (fourth electric device EQ4) is arranged at a position behind the hydraulic oil tank 64 and in front of the fan 45. The fourth electric device EQ4 includes a junction box 54 and a lead battery 56. The junction box 54 and the lead battery 56 are arranged side by side on the left side of the battery unit BU. The lead battery 56 is located on the left side of the junction box 54. The electric motor EM is arranged at a position behind the hydraulic oil tank 64 and below the fan 45.

[0076] As described above, even in the second configuration example, as in the first configuration example, a first opening portion 44L1 is provided on the left side (one side) of the machine body (especially the engine room 44 of the upper rotating body 4), and a second opening portion 44R1 is provided on the right side (the other side). In addition, the fan 45 is arranged opposite to the first opening portion 44L1 in the machine body, and the oil cooler 46 is arranged opposite to the second opening portion 44R1 in the machine body. Therefore, even in the second configuration example, the same effect as the first configuration example can be obtained. In more detail, it is possible to efficiently cool various devices in the machine body (for example, the oil cooler 46, the battery unit BU, the electric motor EM, the electrical equipment EQ, etc.), and ensure that the configuration space of the battery unit BU is as large as possible.

[0077] By arranging the battery unit BU between the fan 45 and the oil cooler 46, it is possible to prevent the relatively high temperature wind after cooling the oil cooler 46 from blowing onto the battery unit BU. As a result, the battery unit BU and the oil cooler 46 in the body are efficiently cooled. Therefore, as in the second arrangement example, the battery unit BU may also be arranged between the fan 45 and the oil cooler 46.

[0078] By arranging the third electric device EQ3 (for example, the charger 51) between the fan 45 and the oil cooler 46, it is possible to prevent the relatively high temperature wind after cooling the oil cooler 46 from blowing to the third electric device EQ3. As a result, the third electric device EQ3 and the oil cooler 46 in the machine body are efficiently cooled. Therefore, in the structure in which the hydraulic excavator 1 includes the electric device EQ, as in the second arrangement example, a part of the electric device EQ (the third electric device EQ3) may also be arranged between the fan 45 and the oil cooler 46 in the machine body.

[0079] By arranging the hydraulic oil tank 64 in front of the battery unit BU, it is easier to secure the arrangement space of the battery unit BU in the vertical direction, compared with the first arrangement example in which the hydraulic oil tank 64 is arranged below the battery unit BU. Therefore, it is easier to set a battery unit BU that is larger in the vertical direction. In addition, the empty space in the body in front of the battery unit BU is effectively used as the arrangement space of the hydraulic oil tank 64. From this point of view, in the structure in which the hydraulic excavator 1 includes the hydraulic oil tank 64, the hydraulic oil tank 64 may be arranged in the body in front of the battery unit BU as in the second arrangement example.

[0080] At this time, if the hydraulic oil tank 64 is arranged in a staggered manner in a left-right direction relative to the battery unit BU, the arrangement space of the battery unit BU can be extended forward, and the capacity of the battery unit BU can be further increased. In addition, instead of expanding the arrangement space of the battery unit BU forward, other components can be arranged in the space in front of the battery unit BU. For example, the boom 31 (see Figure 7 , Figure 8 ) is swung by a swing cylinder (not shown). In this way, in order to increase the capacity of the battery unit BU or to effectively utilize the configuration space of other components, as in the second configuration example, the hydraulic oil tank 64 is preferably configured to be offset to either the left or right side (the left side in the second configuration example) relative to the battery unit BU.

[0081] From the viewpoint of effectively utilizing the free space in the body behind the hydraulic oil tank 64 and below the fan 45 , the electric motor EM is preferably arranged behind the hydraulic oil tank 64 and below the fan 45 as in the second arrangement example.

[0082] From the perspective of effectively utilizing the free space within the machine body located behind the working oil tank 64 and in front of the fan 45, it is preferred that the fourth electrical equipment EQ4 (for example, the junction box 54) be arranged on the rear side of the machine body relative to the working oil tank 64 and on the front side of the machine body relative to the fan 45, as in the second arrangement example.

[0083] If the control valve 62 is arranged above the hydraulic oil tank 64, even if the hydraulic oil leaks from the control valve 62, the leaked hydraulic oil can be prevented from adhering to the battery unit BU. Figure 7 and Figure 8 As shown in the figure, in the structure where the support part 43b1 is located above the hydraulic oil tank 64 via the floor part 43c, it is possible to realize a layout in which the control valve 62 is arranged in the support part 43b1. In this case, it is easy to effectively utilize the space in the support part 43b1, and realize a small hydraulic excavator 1 of an ultra-small swing type. Therefore, in the structure in which the hydraulic excavator 1 is provided with the control valve 62 in addition to the hydraulic oil tank 64, the control valve 62 may also be arranged above the hydraulic oil tank 64 as in the second arrangement example.

[0084] [5. Supplement]

[0085] In this embodiment, a configuration including three (first arrangement example) or four (second arrangement example) battery units BU is described, but the configuration of the battery unit BU is not limited thereto. The battery unit BU may be configured as large as possible according to the arrangement space of the battery unit BU that is ensured.

[0086] In the present embodiment, the configuration of having two (first configuration example) or one (second configuration example) fans 45 is described, but the configuration of the fans 45 is not limited to the above. As long as the wind (air volume) required for cooling the various devices (e.g., oil cooler 46, battery unit BU, etc.) in the engine room 44 can be ensured, the size and number of the fans 45 can be selected according to the required air volume.

[0087] exist Figure 1 and Figure 7 , the first opening 44L1 is shown to be smaller than the outer diameter of the fan 45 (the first fan 45a and the second fan 45b), but it may be formed to be larger than the outer diameter of the fan 45. Figure 2 and Figure 8 In the figure, the second opening 44R1 is shown to be smaller than the outer diameter of the oil cooler 46, but it can also be formed larger than the outer diameter of the oil cooler 46. In addition, protective components (such as shutters, mesh, etc.) can also be installed in the first opening 44L1, the second opening 44R1, and the third opening 44R2. When the above-mentioned protective components are installed, part of the opening is blocked by the protective components, so the size of the opening is preferably selected taking the protective components into consideration.

[0088] In the present embodiment, the structure in which the machine body (right engine hood 44R) has the third opening portion 44R2 is described, but the third opening portion 44R2 is not necessarily required. Even if the third opening portion 44R2 is not provided, the air taken into the machine body from the first opening portion 44L1 is discharged to the outside of the machine body from the second opening portion 44R1. Therefore, the fact that the wind flows from the left side to the right side in the machine body remains unchanged. Moreover, the fact that the various devices in the machine body (such as the oil cooler 46, the battery unit BU, etc.) are cooled by the above-mentioned wind remains unchanged. That is, even in this case, the effect of efficiently cooling the various devices in the machine body and setting the battery unit BU as large as possible in the limited space in the machine body can be obtained.

[0089] In the present embodiment, the first opening 44L1, the second opening 44R1, and the third opening 44R2 are provided in the engine room 44 so that the wind flows from the left side to the right side inside the engine room 44, and the fan 45 is provided at a position opposite to the first opening 44L1 inside the engine room 44, but the present invention is not limited to this configuration. For example, the openings and the fan 45 may be arranged so that the wind flows from the right side to the left side inside the engine room 44. In this case, the arrangement of the devices (parts) in the engine room 44 in the left-right direction is opposite to that of the present embodiment.

[0090] In this embodiment, the hydraulic excavator 1 as a construction machine is taken as an example of the electric working machine, but the electric working machine is not limited to the hydraulic excavator 1, and may be a construction machine such as a wheel loader. In addition, the electric working machine may be an agricultural machine such as a combine harvester or a tractor.

[0091] [6. Notes]

[0092] The hydraulic excavator 1 described in the present embodiment can also be expressed as an electric working machine as shown in the following additional description.

[0093] The electric working machine of supplementary note (1) has in the machine body:

[0094] Battery cells, which store electricity;

[0095] an electric motor driven by receiving the electric power from the battery unit;

[0096] a hydraulic pump driven by the electric motor;

[0097] an oil cooler for cooling the hydraulic oil discharged from the hydraulic pump; and

[0098] A fan is used to obtain air into the above-mentioned machine body.

[0099] The body has a first opening and a second opening.

[0100] The first opening is disposed on one side of the housing.

[0101] The second opening is arranged on the other side of the body.

[0102] The fan is disposed in the housing opposite to the first opening.

[0103] The oil cooler is disposed in the body so as to face the second opening.

[0104] The electric working machine of Supplement (2) is configured as follows: based on the electric working machine described in Supplement (1),

[0105] The battery unit is disposed between the fan and the second opening when viewed from the rear side.

[0106] The electric working machine of Supplement (3) is configured as follows: based on the electric working machine described in Supplement (2),

[0107] An electrical device connected to the battery unit,

[0108] The electrical device includes a first electrical device located in the body at a position closer to the rear side of the body than the battery unit.

[0109] The first electrical device is disposed in the machine body between the fan and the oil cooler.

[0110] The electric working machine of Supplement (4) is configured as follows: based on the electric working machine described in Supplement (3),

[0111] A working oil tank storing the working oil is provided.

[0112] The electric motor and the working oil tank are arranged in parallel below the battery unit in the body.

[0113] The electric motor is disposed on one side of the machine body.

[0114] The hydraulic oil tank is provided on the other side of the machine body.

[0115] The electric working machine of Supplement (5) is configured as follows: based on the electric working machine described in Supplement (3) or (4),

[0116] The fan is arranged on the side of the battery unit.

[0117] The electric working machine of Supplement (6) is configured as follows: based on the electric working machine described in Supplement (5),

[0118] When viewed from the side, a portion of the fan is located on the rear side of the body relative to the battery unit.

[0119] The electric working machine of Supplement (7) is configured as follows: based on the electric working machine described in any one of Supplements (3) to (6),

[0120] The oil cooler is disposed on the rear side of the body relative to the battery unit.

[0121] The electric working machine of Supplement (8) is configured as follows: based on the electric working machine described in any one of Supplements (3) to (7),

[0122] The body has a third opening, which is disposed on the other side and is located forward of the second opening.

[0123] At least a portion of the third opening is located at a position overlapping with a front portion of the battery cell when viewed from the side.

[0124] The electric working machine of Supplement (9) is configured as follows: based on the electric working machine described in Supplement (8),

[0125] The electrical device includes a second electrical device located in the machine body at a position closer to the front side of the machine body than the fan.

[0126] The second electrical device is disposed on the side of the battery unit and on the side of the body.

[0127] The electric working machine of Supplement (10) is configured as follows: based on the electric working machine described in any one of Supplements (1) to (9),

[0128] A plurality of the fans are arranged in an up-and-down direction.

[0129] The electric working machine of Supplement (11) is configured as follows: based on the electric working machine described in Supplement (1),

[0130] The battery unit is arranged between the fan and the oil cooler.

[0131] The electric working machine of Supplement (12) is configured as follows: based on the electric working machine described in Supplement (11),

[0132] An electrical device connected to the battery unit,

[0133] The electrical device includes a third electrical device located between the fan and the oil cooler in the machine body.

[0134] The electric working machine of Supplement (13) is configured as follows: based on the electric working machine described in Supplement (12),

[0135] A working oil tank storing the working oil is provided.

[0136] The hydraulic oil tank is disposed in the body at a position closer to the front side of the body than the battery unit.

[0137] The electric working machine of Supplementary Note (14) is configured as follows: based on the electric working machine described in Supplementary Note (13),

[0138] The hydraulic oil tank is disposed so as to be offset to either the left or the right with respect to the battery unit.

[0139] The electric working machine of Supplement (15) is configured as follows: based on the electric working machine described in Supplement (13) or (14),

[0140] The electric motor is arranged below the fan on the rear side of the machine body relative to the hydraulic oil tank.

[0141] The electric working machine of Supplement (16) is configured as follows: based on the electric working machine described in any one of Supplements (13) to (15),

[0142] The electrical device includes a fourth electrical device disposed in the body.

[0143] The fourth electrical device is located on the rear side of the machine body relative to the hydraulic oil tank and on the front side of the machine body relative to the fan.

[0144] The electric working machine of Supplement (17) is configured as the electric working machine according to any one of Supplements (13) to (16), further comprising:

[0145] a hydraulic actuator driven by the above-mentioned working oil; and

[0146] a control valve for controlling the flow direction and flow rate of the hydraulic oil supplied from the hydraulic pump to the hydraulic actuator,

[0147] The control valve is arranged above the hydraulic oil tank.

[0148] As mentioned above, although embodiment of this invention was described, the scope of this invention is not limited to this, It can implement expanding or changing within the range which does not deviate from the summary of this invention.

[0149] Industrial Applicability

[0150] The present invention can be used in electric working machines such as construction machines and agricultural machines, for example.

Claims

1. An electric working machine, characterized in that: In the body, there are: Battery cells, which store electricity; an electric motor driven by receiving the electric power supplied from the battery unit; a hydraulic pump driven by the electric motor; an oil cooler for cooling the working oil discharged from the hydraulic pump; as well as A fan is used to draw air into the machine body. The body has a first opening and a second opening. The first opening is disposed on one side of the housing. The second opening is arranged on the other side of the body. The fan is disposed within the housing opposite to the first opening. The oil cooler is arranged in the body so as to face the second opening.

2. The electric working machine according to claim 1, characterized in that: The battery unit is arranged between the fan and the second opening when viewed from the back.

3. The electric working machine according to claim 2, characterized in that: An electrical device connected to the battery unit is provided, The electrical device includes a first electrical device, the first electrical device being located within the body at a position closer to the rear side of the body than the battery unit. The first electrical device is arranged between the fan and the oil cooler in the machine body.

4. The electric working machine according to claim 3, characterized in that: A working oil tank storing the working oil is provided, The electric motor and the hydraulic oil tank are arranged in parallel in the body below the battery unit. The electric motor is disposed on one side of the machine body. The hydraulic oil tank is provided on the other side of the machine body.

5. The electric working machine according to claim 3, characterized in that: The fan is arranged on the side of the battery unit.

6. The electric working machine according to claim 5, characterized in that: When viewed from the side, a portion of the fan is located on the rear side of the body relative to the battery unit.

7. The electric working machine according to claim 3, characterized in that: The oil cooler is arranged on the rear side of the machine body relative to the battery unit.

8. The electric working machine according to claim 3, characterized in that: The housing has a third opening, the third opening being disposed on the other side and located forward of the second opening. When viewed from the side, at least a portion of the third opening is located at a position overlapping with a front portion of the battery cell.

9. The electric working machine according to claim 8, characterized in that: The electrical device includes a second electrical device, the second electrical device being located in the machine body at a position closer to the front side of the machine body than the fan, The second electrical device is disposed on the side of the battery unit and on the side of the body.

10. The electric working machine according to any one of claims 1 to 9, characterized in that: A plurality of fans are arranged in an up-and-down direction.

11. The electric working machine according to claim 1, characterized in that: The battery unit is arranged between the fan and the oil cooler.

12. The electric working machine according to claim 11, characterized in that: An electrical device connected to the battery unit is provided, The electrical equipment includes a third electrical equipment located between the fan and the oil cooler in the machine body.

13. The electric working machine according to claim 12, characterized in that: A working oil tank storing the working oil is provided, The hydraulic oil tank is arranged in the body at a front side of the body relative to the battery unit.

14. The electric working machine according to claim 13, characterized in that: The hydraulic oil tank is disposed so as to be offset to either the left or the right with respect to the battery unit.

15. The electric working machine according to claim 13, characterized in that: The electric motor is arranged below the fan on the rear side of the machine body relative to the hydraulic oil tank.

16. The electric working machine according to claim 13, characterized in that: The electrical device includes a fourth electrical device disposed in the body, The fourth electrical device is located on the rear side of the machine body relative to the hydraulic oil tank and on the front side of the machine body relative to the fan.

17. The electric working machine according to any one of claims 13 to 16, characterized in that: Also available: a hydraulic actuator driven by the working oil; and a control valve for controlling a flow direction and a flow rate of the hydraulic oil supplied from the hydraulic pump to the hydraulic actuator, The control valve is arranged above the hydraulic oil tank.

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