Electric work machinery

Abstract

To cool first and second heat exchangers with a compact layout.SOLUTION: A hydraulic excavator as an electrical work machine includes a plurality of electric devices, a first heat exchanger for cooling a refrigerant passing through at least one of the plurality of electric devices, a hydraulic pump driven by any one of the plurality of electric devices to discharge hydraulic oil, a second heat exchanger for cooling the hydraulic oil, and a fan for taking in outside air into a machine body. The first heat exchanger is disposed upstream of the fan in a flow direction of the outside air caused by the fan, and the second heat exchanger is disposed downstream of the fan in the flow direction of the outside air.SELECTED DRAWING: Figure 6

Description

Technical Field

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

Background Art

[0002] Conventionally, various electric working machines such as electric hydraulic excavators have been proposed. For example, in Patent Document 1, an electric hydraulic excavator having a separate fan for cooling a radiator and a separate fan for cooling an oil cooler is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, in a small rear-swing type electric working machine such as a mini excavator, the layout space of each member in the engine room is limited. Therefore, in a small electric working machine, it is usually difficult to provide a cooling fan individually corresponding to a radiator and an oil cooler as in Patent Document 1. Therefore, in a small electric working machine, it is desired to cool a radiator and an oil cooler with a compact layout.

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide an electric working machine capable of cooling a radiator (first heat exchanger) and an oil cooler (second heat exchanger) with a compact layout.

Means for Solving the Problems

[0006] An electric work machine according to one aspect of the present invention comprises a plurality of electrical devices, a first heat exchanger for cooling a refrigerant passing through at least one of the plurality of electrical devices, a hydraulic pump driven by any of the plurality of electrical devices for discharging hydraulic fluid, a second heat exchanger for cooling the hydraulic fluid, and a fan for taking in outside air into the machine body, wherein the first heat exchanger is positioned upstream of the fan in the direction of the outside air flow by the fan, and the second heat exchanger is positioned downstream of the fan in the direction of the outside air flow. [Effects of the Invention]

[0007] With the above configuration, the first and second heat exchangers can be cooled in a compact layout. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view showing the schematic configuration of a hydraulic excavator, which is an example of an electric work machine according to one embodiment of the present invention. [Figure 2] This is a schematic block diagram showing the electrical and hydraulic system configurations of the above-mentioned hydraulic excavator. [Figure 3] This is a plan view showing the internal configuration of the engine room of the hydraulic excavator described above. [Figure 4] This is a right-side view showing the internal layout of the engine room. [Figure 5] This is a cross-sectional view showing the internal configuration of the engine room. [Figure 6] This is a magnified perspective view showing the main components of the interior of the engine room described above. [Figure 7] This is a perspective view of the air duct section of the hydraulic excavator shown above. [Figure 8] This is a perspective view of the above-mentioned air duct section. [Figure 9] This is a perspective view of the above-mentioned air duct section. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the drawings.

[0010] [1. Electric working machines] Figure 1 is a side view showing the schematic configuration of a hydraulic excavator (electric excavator) 1, which is an example of an electric work machine of this embodiment. The hydraulic excavator 1 comprises a lower traveling body 2, a work machine 3, and an upper rotating body 4. In this embodiment, the hydraulic excavator 1 or the upper rotating body 4 (particularly the engine room 44) is also referred to as the "machine body".

[0011] Here, direction is defined as follows: The direction in which the operator (driver, operator) seated in the driver's seat 41a of the upper slewing body 4 faces forward is defined as forward, and the opposite direction is defined as rear. Therefore, when the upper slewing body 4 is not slewing relative to the lower traveling body 2 (slewing angle 0°), the longitudinal direction of the upper slewing body 4 coincides with the direction in which the lower traveling body 2 moves forward and backward. Also, the left side as seen from the perspective of the operator seated in the driver's seat 41a is defined as "left," and the right side as "right." Furthermore, the direction of gravity perpendicular to the longitudinal and left-right directions is defined as the up-down direction, with the upstream side of the direction of gravity being defined as "up," and the downstream side being defined as "down." In the drawing, the hydraulic excavator 1 is shown with the upper slewing body 4 not slewing relative to the lower traveling body 2. Also, in the drawing, the forward direction is indicated by the symbol "F," the rear by "B," the right by "R," the left by "L," the upper by "U," and the lower by "D," as needed.

[0012] The lower travel body 2 comprises a pair of left and right crawlers 21 and a pair of left and right travel motors 22. Each travel motor 22 is a hydraulic motor. The left and right travel motors 22 drive the left and right crawlers 21 respectively, allowing the hydraulic excavator 1 to move forward and backward. The lower travel body 2 is equipped with a blade 23 for leveling work and a blade cylinder 23a. The blade cylinder 23a is a hydraulic cylinder that rotates the blade 23 in the vertical direction.

[0013] The work machine 3 comprises a boom 31, an arm 32, and a bucket 33. By independently driving the boom 31, arm 32, and bucket 33, excavation work such as soil and sand can be performed.

[0014] The boom 31 is rotated by the boom cylinder 31a. The base end portion of the boom cylinder 31a is supported by the front portion of the upper swing body 4 and is movably extendable and retractable. The arm 32 is rotated by the arm cylinder 32a. The base end portion of the arm cylinder 32a is supported by the boom 31 and is movably extendable and retractable. The bucket 33 is rotated by the bucket cylinder 33a. The base end portion of the bucket cylinder 33a is supported by the arm 32 and is movably extendable and retractable. The boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33a are constituted by hydraulic cylinders.

[0015] The upper swing body 4 is located above the lower traveling body 2 and is provided so as to be rotatable with respect to the lower traveling body 2 via a swing bearing (not shown). A cab 41, a swing frame 42, a swing motor 43, an engine room 44, etc. are arranged on the upper swing body 4. The upper swing body 4 rotates via the swing bearing by the drive of the swing motor 43 which is a hydraulic motor.

[0016] A hydraulic pump 71 (see FIG. 2) is arranged on the upper swing body 4. The hydraulic pump 71 is driven by an electric motor 61 (see FIG. 2) inside the engine room 44. The hydraulic pump 71 supplies hydraulic oil (pressure oil) to hydraulic motors (for example, left and right traveling motors 22, swing motor 43), and hydraulic cylinders (for example, blade cylinder 23a, boom cylinder 31a, arm cylinder 32a, bucket cylinder 33a). The hydraulic motors and hydraulic cylinders driven by the supply of hydraulic oil from the hydraulic pump 71 are collectively called a hydraulic actuator 73 (see FIG. 2).

[0017] A driver's seat 41a is arranged in the cab 41. Various levers 41b are arranged around the driver's seat 41a. When the operator sits on the driver's seat 41a and operates the lever 41b, the hydraulic actuator 73 is driven. Thereby, traveling of the lower traveling body 2, land leveling work by the blade 23, excavation work by the work implement 3, turning of the upper swing body 4, etc. can be performed.

[0018] In the upper revolving body 4, a battery unit 53 is arranged. The battery unit 53 is composed of, for example, a lithium-ion battery unit and stores electric power for driving the electric motor 61. The battery unit 53 may be composed of a plurality of batteries unitized or may be composed of a single battery cell. Also, in the upper revolving body 4, a power supply port (not shown) is provided. The above power supply port and a commercial power supply 51 which is an external power source are connected via a power supply cable 52. Thereby, the battery unit 53 can be charged.

[0019] In the upper revolving body 4, a lead battery 54 is further provided. The lead battery 54 outputs a DC voltage of a low voltage (for example, 12V). The output from the lead battery 54 is supplied as a control voltage to, for example, a drive unit of a system controller 67 (see FIG. 2), a fan 91 (see FIG. 6, etc.).

[0020] The hydraulic excavator 1 may have a configuration in which hydraulic devices such as a hydraulic actuator 73 and an actuator driven by electric power are used in combination. Examples of the actuator driven by electric power include an electric travel motor, an electric cylinder, and an electric swing motor.

[0021] 〔2. Configuration of Electrical System and Hydraulic System〕 FIG. 2 is a block diagram schematically showing the configuration of the electrical system and the hydraulic system of the hydraulic excavator 1. The hydraulic excavator1 includes an electric motor 61, a charger 62, an inverter 63, a PDU (Power Drive Unit) 64, a junction box 65, a DC-DC converter 66, and a system controller 67.

[0022] The electric motor 61, charger 62, inverter 63, PDU 64, junction box 65, DC-DC converter 66, battery unit 53, and lead-acid battery 54 constitute the electrical equipment EL. In other words, the hydraulic excavator 1 is equipped with multiple electrical equipment ELs. The multiple electrical equipment ELs include water-cooled electrical equipment EL-W and air-cooled electrical equipment EL-A, details of which will be described later. The system controller 67 is composed of an electronic control unit also called an ECU (Electronic Control Unit) and performs electrical control of each part of the hydraulic excavator 1.

[0023] The electric motor 61 is driven by power supplied from the battery unit 53 via the junction box 65 and inverter 63. The electric motor 61 consists of a permanent magnet motor or an induction motor. The electric motor 61 is mounted on the slewing frame 42.

[0024] The charger 62 (also called a power supply) converts the AC voltage supplied from the commercial power supply 51 shown in Figure 1 via the power supply cable 52 into a DC voltage. The inverter 63 converts the DC voltage supplied from the battery unit 53 into an AC voltage and supplies it to the electric motor 61. This causes the electric motor 61 to rotate. The supply of AC voltage (current) from the inverter 63 to the electric motor 61 is performed based on a rotation command output from the system controller 67.

[0025] The PDU64 is a battery control unit that controls the input and output of the battery unit 53 by controlling an internal battery relay. The junction box 65 is composed of a charger relay, an inverter relay, a fuse, etc. The voltage output from the charger 62 is supplied to the battery unit 53 via the junction box 65 and the PDU64. The voltage output from the battery unit 53 is supplied to the inverter 63 via the PDU64 and the junction box 65.

[0026] The DC-DC converter 66 steps down the high-voltage (e.g., 300V) DC voltage supplied from the battery unit 53 via the junction box 65 to a low voltage (e.g., 12V). The voltage output from the DC-DC converter 66 is supplied to the system controller 67, the drive unit of the fan 91, and the like, similar to the output from the lead-acid battery 54.

[0027] Multiple hydraulic pumps 71 are connected to the rotating shaft (output shaft) of the electric motor 61. The multiple hydraulic pumps 71 include variable displacement pumps and fixed displacement pumps. In Figure 2, only one hydraulic pump 71 is shown as an example. Each hydraulic pump 71 is connected to a hydraulic fluid tank 74 that contains (stores) hydraulic fluid. When the electric motor 61 drives the hydraulic pumps 71, the hydraulic fluid in the hydraulic fluid tank 74 is supplied to the hydraulic actuator 73 via a control valve 72. This drives the hydraulic actuator 73. The control valve 72 is a directional valve that controls the flow direction and flow rate of the hydraulic fluid supplied to the hydraulic actuator 73. Thus, the hydraulic excavator 1 is equipped with hydraulic pumps 71 that discharge hydraulic fluid when driven by one of the multiple electrical devices EL (e.g., the electric motor 61).

[0028] [3. Internal layout of the engine room] Figures 3 and 4 are a plan view and a right side view, respectively, showing the internal configuration of the engine room 44 of the hydraulic excavator 1. Figure 5 is a cross-sectional view of the engine room 44 shown in Figure 3, taken vertically through the line A-A'. Figure 6 is an enlarged perspective view showing the main configuration of the engine room 44. Note that in Figures 3 and 6, the top surface 90a of the housing 90 (see Figures 4 and 5) and the top surface 100a of the air duct 100 (see Figure 5) are omitted from the illustration in order to clarify the internal configuration of the housing 90 and the air duct 100.

[0029] As shown in Figure 3, in this embodiment, four battery units 53 are arranged in a front-to-back direction on the slewing frame 42 via vibration-damping members 80 (see Figure 5), etc. The rearmost battery unit 53 is located in the center in the left-to-right direction on the slewing frame 42. The remaining three battery units 53 are positioned offset to the left of the rearmost battery unit 53. This allows multiple battery units 53 to be efficiently arranged in the limited narrow space near the rear edge of the slewing frame 42, which is formed in a semicircular shape in plan view. Note that the number and arrangement of the battery units 53 are not limited to the example of this embodiment.

[0030] As shown in Figure 5, the electric motor 61, hydraulic pump 71, etc., are arranged on the right side of the multiple battery units 53 on the slewing frame 42. The following describes the detailed configuration of the inside of the engine room 44.

[0031] As shown in Figure 6, the hydraulic excavator 1 is equipped with a fan 91. The fan 91 is rotatably supported inside the housing 90 and draws outside air into the machine body by rotating. That is, the fan 91 in this embodiment is a suction type. The housing 90 is frame-shaped and has openings at both ends in the left-right direction. The rotation axis CA of the fan 91 extends in the left-right direction. Below the fan 91 (housing 90) is a hydraulic pump 71. The hydraulic pump 71 is connected to a hydraulic oil tank 74 via a hydraulic hose H (see Figure 4).

[0032] An air duct 100 is positioned on the left side of the housing 90, that is, between the housing 90 and the battery unit 53 (especially the battery unit 53 located furthest forward). Details of the air duct 100 will be described later. The electrical equipment EL, such as the inverter 63 and DC-DC converter 66 mentioned above, is attached to the air duct 100 (especially the second flow path section 120, which will be described later).

[0033] As shown in Figures 3 and 4, the charger 62 described above is positioned behind the fan 91 (housing 90) and the hydraulic pump 71.

[0034] The hydraulic excavator 1 further comprises a radiator 92 and an oil cooler 93. The radiator 92 is a first heat exchanger that cools the refrigerant passing through at least one of the multiple electrical devices EL shown in Figure 3, etc. (for example, a battery unit 53). By cooling the refrigerant through heat exchange in the radiator 92 and supplying the refrigerant from the radiator 92 to the battery unit 53, the battery unit 53 can be cooled (water-cooled). The refrigerant is, for example, cooling water.

[0035] The oil cooler 93 is a second heat exchanger connected to an oil passage that circulates via a hydraulic pump 71 and a hydraulic actuator 73 (see Figure 2), etc. The oil cooler 93 cools the hydraulic fluid flowing through the oil passage by heat exchange when driven by the hydraulic pump 71.

[0036] As shown in Figure 6, the radiator 92 is located to the right of the fan 91. In other words, the radiator 92 is located outside the aircraft body in the left-right direction compared to the fan 91. As mentioned above, the fan 91 is a suction type, so when the fan 91 rotates, outside air is drawn into the aircraft body from the outside. This outside air then flows through the inside of the aircraft body from right to left. In other words, the outside air flows from the radiator 92 towards the fan 91. From this, it can be said that the radiator 92 is positioned upstream of the fan 91 in the direction of outside air flow caused by the fan 91.

[0037] On the other hand, the oil cooler 93 is located to the left of the fan 91. In other words, the oil cooler 93 is located inside the aircraft in the left-right direction compared to the fan 91. Therefore, when the fan 91 rotates, the outside air drawn into the aircraft from the outside flows from the right side (radiator 92 side) through the fan 91 to the left side (oil cooler 93 side). From this, it can be said that the oil cooler 93 is positioned downstream of the fan 91 in the direction of the outside air flow.

[0038] In this configuration, the radiator 92 and oil cooler 93 are positioned on opposite sides of the fan 91 in the left-right direction. This allows a single fan 91 to draw in outside air from the outside of the machine into the machine body, directing it to the radiator 92 and then the oil cooler 93, thereby cooling both the radiator 92 and the oil cooler 93. This enables a more compact layout, which is advantageous for a small hydraulic excavator 1, compared to a configuration where a separate cooling fan is provided for each of the radiator 92 and the oil cooler 93. In other words, both the radiator 92 and the oil cooler 93 can be cooled in a compact layout.

[0039] Furthermore, since the outside air directed at the radiator 92 can also be directed at the oil cooler 93, it can be said that the outside air used to cool the radiator 92 can be effectively utilized to cool the oil cooler 93. In addition, since the radiator 92 is positioned upstream of the direction of outside air flow from the fan 91, the radiator 92 can prevent foreign objects such as dirt and sand, as well as human hands (for example, maintenance personnel) from accidentally entering from the outside of the machine toward the fan 91. This makes it possible to easily prevent the entry of foreign objects without installing special components (for example, a mesh fence) to block the entry of foreign objects.

[0040] In this embodiment, as shown in Figures 3 and 6, the oil cooler 93 is positioned opposite a portion of the fan 91 (in a stationary state). That is, in the front-to-back direction, the length (width) occupied by the oil cooler 93 is shorter than the length (width) occupied by the fan 91. As described above, the fan 91 is a suction type, so when the fan 91 is rotated, some of the outside air taken into the machine flows toward the oil cooler 93, and the rest flows away from the oil cooler 93. The outside air flowing toward the oil cooler 93 from the fan 91 cools the high-temperature oil cooler 93. On the other hand, the outside air flowing away from the oil cooler 93 from the fan 91 does not come into contact with the high-temperature oil cooler 93, and is therefore relatively cooler than the outside air that comes into contact with the oil cooler 93 (the outside air used to cool the oil cooler 93). From the viewpoint of effectively utilizing this relatively low-temperature outside air for cooling electrical equipment EL (e.g., electric motor 61), it is desirable that the oil cooler 93 be positioned opposite a part of the fan 91, as in this embodiment.

[0041] Next, we will describe the details of the air duct 100 located inside the engine room 44. Figures 7 to 9 are perspective views of the air duct 100 from different directions.

[0042] The air guide section 100 has a first flow path section 110 and a second flow path section 120. That is, the hydraulic excavator 1 has a first flow path section 110 and a second flow path section 120. The first flow path section 110 and the second flow path section 120 are separated by a partition plate 130. In other words, the first flow path section 110 and the second flow path section 120 share the same partition plate 130.

[0043] As shown in Figure 6, the air guide section 100 is located to the left of the housing 90, which has the fan 91, that is, inside the machine. Therefore, outside air that has passed through the inside of the housing 90 by the fan 91 is guided to the air guide section 100 through the outlet opening 90b of the housing 90 and flows through either the first flow path section 110 or the second flow path section 120 of the air guide section 100.

[0044] The first flow path section 110 has a first opening 111 at its upstream end in the direction of outside air flow and a second opening 112 at its downstream end. That is, the first flow path section 110 has a first opening 111 at one end and a second opening 112 at the other end. The first opening 111 is located on the opposite side of the oil cooler 93 from the outlet opening 90b of the housing 90 and opens toward the right in the left-right direction. The flow path of the first flow path section 110 is bent from the left-right direction to the front-rear direction by the partition plate 130. As a result, the second opening 112 of the first flow path section 110 opens toward the front in the front-rear direction (see Figures 6, 8, and 9). Note that the shape of the first flow path section 110 is not limited to the bent shape described above.

[0045] In this configuration, the outside air flowed by the fan 91 towards the oil cooler 93 within the housing 90 cools the oil cooler 93, and then becomes a relatively hot air that flows into the first flow path section 110 through the first opening 111. The relatively hot air that has flowed inside the first flow path section 110 is then discharged through the second opening 112. Therefore, in order to smoothly discharge the relatively hot air that has cooled the oil cooler 93 to the outside of the machine through the second opening 112, it is desirable that the first opening 111 be located on the opposite side of the oil cooler 93 from the fan 91, as shown in Figure 6.

[0046] The second flow path section 120 has a third opening 121 at its upstream end in the direction of outside air flow and a fourth opening 122 at its downstream end. That is, the second flow path section 120 has a third opening 121 at one end and a fourth opening 122 at the other end. The third opening 121 is located on the opposite side of the fan 91 from the outlet opening 90b of the housing 90 and opens toward the right in the left-right direction. The flow path of the second flow path section 120 is bent from the left-right direction to the up-down direction by an inclined surface 100b that slopes downward from the left end of the upper surface 100a toward the inside of the machine (left side in the left-right direction). As a result, the fourth opening 122 of the second flow path section 120 opens toward the downward direction. Note that the shape of the second flow path section 120 is not limited to the bent shape described above.

[0047] Furthermore, the third opening 121 of the second flow path section 120 is positioned alongside the first opening 111 of the first flow path section 110 (in the FB direction in Figure 7, etc.) when viewed from the direction of the rotation axis CA of the fan 91, and is connected to the first opening 111. As a result, one large opening is formed on the housing 90 side of the air guide section 100. Moreover, as shown in Figure 6, the third opening 121 is positioned offset from the oil cooler 93 (in the FB direction) when viewed from the direction of the rotation axis CA of the fan 91. Therefore, the third opening 121 does not overlap with the oil cooler 93 when viewed from the direction of the rotation axis CA of the fan 91.

[0048] In this configuration, the fan 91 draws in outside air into the housing 90 via the radiator 92, and the outside air that flows away from the oil cooler 93 is guided into the second flow path section 120 through the third opening 121. The outside air that flows through the second flow path section 120 is then discharged from the fourth opening 122. The outside air that flows away from the oil cooler 93 does not come into contact with the high-temperature oil cooler 93, and is therefore relatively cooler than the outside air that does come into contact with the oil cooler 93 (the outside air used to cool the oil cooler 93). From the viewpoint of effectively utilizing this relatively cool outside air for cooling electrical equipment EL (e.g., electric motor 61), it is desirable that the third opening 121, which serves as the inlet for guiding the relatively cool outside air into the second flow path section 120, be positioned offset from the oil cooler 93 when viewed from the direction of the rotation axis CA of the fan 91, as in this embodiment.

[0049] As shown in Figure 2, the multiple electrical devices EL provided by the hydraulic excavator 1 include a water-cooled device EL-W through which the refrigerant described above flows, and an air-cooled device EL-A. The water-cooled device EL-W is, for example, a battery unit 53. In other words, the multiple electrical devices EL include a battery unit 53 through which the refrigerant flows.

[0050] The air-cooled equipment EL-A includes, for example, an electric motor 61, a charger 62, an inverter 63, a PDU 64, a junction box 65, a DC-DC converter 66, and a lead-acid battery 54. In other words, multiple air-cooled equipment EL-A include an electric motor 61 that drives a hydraulic pump 71.

[0051] If the relatively cool air that flows after the fan 91 has cooled the radiator 92, then bypasses the oil cooler 93 (passing outside the oil cooler 93), enters the second flow path section 120 through the third opening 121, and is discharged from the fourth opening 122 can be directed directly onto the air-cooled equipment EL-A, then the air-cooled equipment EL-A can be efficiently cooled (air-cooled). Therefore, from the viewpoint of improving the cooling efficiency of the air-cooled equipment EL-A, it is desirable that one of the multiple air-cooled equipment EL-A be positioned at the fourth opening 122 of the second flow path section 120.

[0052] In this embodiment, the electric motor 61, which is the air-cooled device EL-A, is positioned in the fourth opening 122. In this case, the relatively low-temperature air discharged from the fourth opening 122 directly hits the electric motor 61, thereby improving the cooling efficiency of the electric motor 61.

[0053] Furthermore, from the viewpoint of achieving a compact layout by fitting the air-cooling equipment EL-A (e.g., electric motor 61) into the fourth opening 122 of the second flow channel section 120 from below, it is desirable that the fourth opening 122 opens downward, as in this embodiment.

[0054] From the viewpoint of efficiently cooling other air-cooled equipment EL-A (other than the electric motor 61) with the relatively low-temperature air flowing inside the second flow channel 120, it is desirable that one of the other air-cooled equipment EL-A be placed on the wall surface 120W of the second flow channel 120 (see Figures 7 and 9).

[0055] In this embodiment, the inverter 63 is positioned on the rear side surface 120W1 (see Figure 7) of the second flow channel section 120. Furthermore, the DC-DC converter 66 is positioned on the rear surface 120W2 (see Figure 9) of the inclined surface 100b of the air guide section 100, which constitutes the second flow channel section 120. In this case, relatively low-temperature air flows through the inside of the second flow channel section 120, efficiently cooling the inverter 63, which is an air-cooled device EL-A positioned on the side surface 120W1, and also efficiently cooling the DC-DC converter 66, which is an air-cooled device EL-A positioned on the rear surface 120W2.

[0056] Furthermore, the air-cooled device EL-A, which is positioned on the wall surface 120W of the second flow channel 120, may have heat dissipation parts such as fins. In addition, the heat dissipation parts may be positioned to protrude into the interior of the second flow channel 120. In this case, the cooling efficiency of the air-cooled device EL-A positioned on the wall surface 120W is further improved as the relatively low-temperature air flowing inside the second flow channel 120 hits the heat dissipation parts.

[0057] From the viewpoint of using the relatively low-temperature air discharged from the fourth opening 122 of the second flow channel 120 to cool other air-cooled equipment EL-A, any of the other air-cooled equipment EL-A may be located outside the second flow channel 120.

[0058] In this embodiment, other air-cooled equipment EL-A, such as a charger 62 and a junction box 65, are arranged outside the second flow path section 120, as shown in Figure 3. In this case, the relatively low-temperature air discharged from the fourth opening 122 of the second flow path section 120 hits the charger 62 and other equipment around the second flow path section 120, cooling the charger 62 and other equipment. In other words, the relatively low-temperature air discharged from the fourth opening 122 is effectively utilized to cool the charger 62 and other equipment.

[0059] From the perspective of effectively utilizing the limited space in the engine room 44 while individually cooling the air-cooled electric motor 61 (EL-A) and the water-cooled battery unit 53 (EL-W), it is desirable to position the electric motor 61 near the water-cooled EL-W within the engine room 44. In this respect, it is desirable to position the electric motor 61 alongside the water-cooled EL-W.

[0060] Furthermore, in order to effectively utilize the limited space in the engine room 44 while cooling the water-cooled equipment EL-W and the multiple air-cooled equipment EL-A separately, it is desirable that the battery unit 53, which is the water-cooled equipment EL-W, be located near the second flow path section 120 (where the multiple air-cooled equipment EL-A are arranged on the wall surface 120W) within the engine room 44. In this regard, as shown in Figure 5, it is desirable that the battery unit 53 be located alongside the second flow path section 120.

[0061] [4. Supplement] In this embodiment, as shown in Figure 6, an example has been described in which the oil cooler 93 is positioned to overlap with a part of the radiator 92 when viewed from the direction of the rotation axis CA of the fan 91. However, the oil cooler 93 may be positioned so as not to overlap with the radiator 92. For example, when viewed from the direction of the rotation axis CA, the radiator 92 may be positioned to overlap with the left half of the fan 91, and the oil cooler 93 may be positioned to overlap with the right half of the fan 91. Even in this case, both the radiator 92 and the oil cooler 93 can be cooled by driving a single fan 91, and the fact that the radiator 92 and the oil cooler 93 can be cooled in a compact layout remains unchanged.

[0062] In the above explanation, a hydraulic excavator 1, a type of construction machinery, was used as an example of an electric powered work machine. However, electric powered work machines are not limited to hydraulic excavators 1; other construction machinery such as wheel loaders may also be used. Furthermore, electric powered work machines may also be agricultural machinery such as combine harvesters or tractors.

[0063] [5. Addendum] The hydraulic excavator 1 described in this embodiment can also be described as an electric work machine as shown in the following appendix.

[0064] The electric work machines mentioned in Appendix (1) are: Multiple electrical devices, A first heat exchanger that cools the refrigerant passing through at least one of the aforementioned plurality of electrical devices, A hydraulic pump that is driven by one of the aforementioned multiple electrical devices to discharge hydraulic fluid, A second heat exchanger for cooling the aforementioned hydraulic fluid, The aircraft is equipped with a fan that takes in outside air, The first heat exchanger is positioned upstream of the fan in the direction of the outside air flow by the fan. The second heat exchanger is positioned downstream of the fan in the direction of the outside air flow.

[0065] The electric work machine in Appendix (2) is the same as the electric work machine described in Appendix (1), The second heat exchanger is positioned opposite a portion of the fan.

[0066] The electric work machines in Appendix (3) are the electric work machines described in Appendix (2), The device further comprises a first flow channel having a first opening at one end and a second opening at the other end. The first opening of the first flow channel is located on the opposite side of the second heat exchanger from the fan.

[0067] The electric work machines in Appendix (4) are the electric work machines described in Appendix (3), The system further comprises a second flow channel having a third opening at one end and a fourth opening at the other end. The third opening of the second flow channel is positioned parallel to the first opening of the first flow channel when viewed from the direction of the rotation axis of the fan, and is offset from the second heat exchanger.

[0068] The electric work machines in Appendix (5) are the electric work machines described in Appendix (4), The aforementioned plurality of electrical devices include a water-cooled device through which the refrigerant flows, and a plurality of air-cooled devices. Any of the above-mentioned air-cooling devices is placed in the fourth opening of the second flow channel.

[0069] The electric work machines in Appendix (6) are the electric work machines described in Appendix (5), Any of the other of the aforementioned air-cooling devices is positioned on the wall surface of the second flow channel.

[0070] The electric work machine in Appendix (7) is an electric work machine described in Appendix (5) or (6), Any of the other of the aforementioned air-cooling devices is positioned outside the second flow path.

[0071] The electric work machine in Appendix (8) is an electric work machine described in any of Appendix (5) to (7), The fourth opening is open downwards.

[0072] The electric work machine in Appendix (9) is an electric work machine described in any of Appendix (5) to (8), The aforementioned plurality of air-cooling devices include an electric motor that drives the hydraulic pump, The electric motor is positioned alongside the water cooling equipment.

[0073] The electric work machine in Appendix (10) is an electric work machine described in any of Appendix (4) to (9), The aforementioned plurality of electrical devices include a battery unit through which the refrigerant flows, The battery unit is arranged alongside the second flow path section.

[0074] Although embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and it can be expanded or modified without departing from the spirit of the invention. [Industrial applicability]

[0075] This invention can be used, for example, in work machinery such as construction machinery and agricultural machinery. [Explanation of symbols]

[0076] 1. Hydraulic excavator (electric work machine) 44. Engine room (aircraft) 53. Battery Units (Electrical Equipment, Water Cooling Equipment) 54. Lead-acid batteries (electrical equipment, air-cooling equipment) 61. Electric motors (electrical equipment, air-cooled equipment) 62 Chargers (Electrical equipment, air-cooling equipment) 63. Inverters (electrical equipment, air-cooling equipment) 65 Junction Box (Electrical Equipment, Air-Cooled Equipment) 66 DC-DC converters (electrical equipment, air-cooled equipment) 71 Hydraulic pump 91 Fans 92 Radiator (First Heat Exchanger) 93 Oil cooler (second heat exchanger) 110 First channel section 111 First opening 112 Second opening 120 Second channel section 120W Wall Mount 120W1 Side (wall) 120W2 Rear (Wall) 121 Third opening 122 Fourth opening CA Rotation Axis EL Electrical Equipment EL-W water cooling equipment EL-A Air cooling equipment

Claims

1. Multiple electrical devices, A first heat exchanger that cools the refrigerant passing through at least one of the aforementioned plurality of electrical devices, A hydraulic pump that is driven by one of the aforementioned multiple electrical devices to discharge hydraulic fluid, A second heat exchanger for cooling the aforementioned hydraulic fluid, The aircraft is equipped with a fan that takes in outside air, The first heat exchanger is positioned upstream of the fan in the direction of the outside air flow by the fan. The second heat exchanger is positioned downstream of the fan in the direction of the outside air flow, The second heat exchanger is positioned opposite a part of the fan, The first flow channel portion further comprises a first opening at one end and a second opening at the other end. The first opening of the first flow channel is located downstream of the second heat exchanger, and is an electrically operated work machine.

2. Further comprising a second flow channel having a third opening at one end and a fourth opening at the other end, The electric work machine according to claim 1, wherein the third opening of the second flow path is positioned in the front-to-back direction alongside the first opening of the first flow path, when viewed from the direction of the rotation axis of the fan, and is offset in the front-to-back direction from the second heat exchanger.

3. The plurality of electrical devices include a water-cooled device through which the refrigerant flows, and a plurality of air-cooled devices, The electric work machine according to claim 2, wherein any of the plurality of air-cooling devices is arranged in the fourth opening of the second flow path.

4. The electric work machine according to claim 3, wherein the second flow channel section has a wall surface on which any other of the plurality of air-cooling devices is arranged.

5. The plurality of air-cooling devices include an electric motor that drives the hydraulic pump, The electric motor is positioned in the fourth opening, as described in claim 3.

6. The electric work machine according to claim 3, wherein the fourth opening is open downward.

7. The plurality of air-cooling devices include an electric motor that drives the hydraulic pump, The electric motor is arranged alongside the water cooling equipment, as described in claim 3, for the electric work machine.

8. The plurality of electrical devices include a battery unit through which the refrigerant flows, The electric work machine according to any one of claims 2 to 7, wherein the battery unit is arranged alongside the second flow path.

9. The plurality of electrical devices are A battery unit is positioned on a rotating frame through which the refrigerant flows, The system includes an electric motor that drives the hydraulic pump, The electric motor and the hydraulic pump are arranged on the slewing frame on one side in the left-right direction relative to the battery unit, as described in any one of claims 1 to 7.

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