Electric work machine

Abstract

To provide an electric work machine configured to cool an electric motor preferentially, as well as other devices arranged inside the body, and enable installation of a large battery unit, thereby increasing battery capacity.SOLUTION: A hydraulic excavator as an electric work machine has a body with a first opening part and a second opening part equipped in an exterior part. The body includes a battery unit for storing electric power, an electric motor which is driven by the power supplied from the battery unit, a hydraulic pump which is driven by the electric motor to eject hydraulic oil, a heat exchanger for cooling the hydraulic oil, and a fan which takes the air through the first opening part into the body and discharges the air through the second opening part to the outside of the body. The first opening part provided in the exterior part is located below the electric motor.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] For example, in the electric hydraulic excavator disclosed in Patent Document 1, a fan is provided to cool the electric motor, hydraulic pump, and oil cooler with cooling air (air-cooling), and a cooling water pump is further provided to cool the electric motor with cooling water (water-cooling). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2011 / 102042 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a small electric work machine in which the space for arranging the equipment including the electric motor, hydraulic pump, and oil cooler is limited, if a cooling water pump is provided to water-cool the electric motor as in Patent Document 1, the space for arranging the battery unit that supplies power to the electric motor becomes narrow, making it difficult to mount a large (large-capacity) battery unit.In addition, the electric motor is the driving source for the hydraulic excavator and tends to generate heat, so it needs to be cooled with priority over other equipment.

[0005] The present invention has been made to solve the above problems, and its object is to provide an electric work machine that is able to cool the electric motor preferentially while also cooling other equipment placed inside the body, and that enables the installation of a larger battery unit, thereby increasing the battery capacity. [Means for solving the problem]

[0006] An electric working machine according to one aspect of the present invention comprises a body having an exterior portion provided with a first opening and a second opening, and has inside the body a battery unit that stores electric power, an electric motor that is driven by the electric power supplied from the battery unit, a hydraulic pump that is driven by the electric motor and discharges hydraulic oil, a heat exchanger that cools the hydraulic oil, and a fan that draws air into the interior of the body through the first opening and exhausts the air to the outside of the body through the second opening, and the first opening provided in the exterior portion is positioned below the electric motor. Effect of the Invention

[0007] According to the above configuration, the electric motor can be cooled preferentially while also cooling other equipment placed inside the aircraft body, and it is possible to install a larger battery unit, thereby increasing the battery capacity. [Brief description of the drawings]

[0008] [Figure 1] 1 is a left side view showing a schematic configuration of a hydraulic excavator, which is an example of an electric working machine according to an embodiment of the present invention. FIG. [Diagram 2] FIG. 2 is a bottom view of an upper rotating body of the hydraulic excavator. [Diagram 3] FIG. 2 is a block diagram showing a schematic configuration of an electrical system and a hydraulic system of the hydraulic excavator. [Figure 4] FIG. 2 is a perspective view showing the internal configuration of the engine room of the upper rotating body from the left front. [Diagram 5] FIG. 2 is a perspective view showing the internal configuration of the engine room from the left rear. [Figure 6] FIG. 2 is a front view showing the arrangement of equipment in the engine room. [Figure 7] FIG. 2 is a left side view showing the arrangement of the above-mentioned devices. [Figure 8] FIG. 2 is a perspective view showing the configuration of an air guide section provided in the engine room, as viewed from the left front. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The following describes an embodiment of the present invention with reference to the drawings.

[0010] [1. Overview of the Electric Working Machine] 1 is a left side view showing a schematic configuration of a hydraulic excavator 1 (electric excavator) which is an example of an electric working machine according to an embodiment of the present invention. The hydraulic excavator 1 includes a lower traveling body 2, a working machine 3, and an upper rotating body 4 (also called a machine body).

[0011] Here, the directions are defined as follows. The direction in which the operator (operator, driver) seated in the driver's seat 44a arranged in the control section 44 of the upper rotating body 4 faces forward is defined as "forward", and the opposite direction is defined as "rearward". When the upper rotating body 4 is in a state where it is not rotating relative to the lower running body 2 (rotation angle of 0 degrees), the front-to-rear direction of the upper rotating body 4 coincides with the front-to-rear direction of the lower running body 2. In the drawings, the hydraulic excavator 1 is shown in a state where the upper rotating body 4 is not rotating relative to the lower running body 2. Also, the left side as viewed from the operator seated in the driver's seat 44a is defined as "left", and the right side is defined as "right". Furthermore, the direction of gravity perpendicular to the front-to-rear direction and the left-to-right direction (also called the width direction) is defined as the up-down direction, and the upstream side of the direction of gravity is defined as "up" and the downstream side is defined as "down". In the drawings, where necessary, forward is indicated with the symbols "F", rear with "B", right with "R", left with "L", upper with "U", and lower with "D".

[0012] The lower traveling structure 2 includes a pair of left and right crawlers 21, a pair of left and right traveling motors 22, and a blade 23. The left and right traveling motors 22 drive the left and right crawlers 21, respectively, to move the hydraulic excavator 1 forward and backward. The traveling motors 22 are configured as hydraulic motors. The blade 23, which performs ground leveling work, is provided on the front side of the lower traveling structure 2. The blade 23 is rotated by a blade cylinder 23a. The blade cylinder 23a is configured as a hydraulic cylinder.

[0013] The work 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, it is possible to perform work of excavating earth and sand, etc.

[0014] The boom 31 is rotated by a boom cylinder 31a. The boom cylinder 31a has a base end supported on the front part of the upper rotating body 4 and is movable so as to be telescopic. In the drawings, the boom cylinder 31a is arranged so that the rod side is the base end, but it may be arranged so that the tube side is the base end. The arm 32 is rotated by an arm cylinder 32a. The arm cylinder 32a has a base end supported by the boom 31 and is movable so as to be telescopic. The bucket 33 is rotated by a bucket cylinder 33a. The bucket cylinder 33a has a base end supported by the arm 32 and is movable so as to be telescopic. The boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33a are each composed of a hydraulic cylinder.

[0015] The configuration of the upper rotating body 4 will be described with reference to Fig. 2. Fig. 2 is a bottom view of the upper rotating body 4. The upper rotating body 4 is located above the lower running body 2, and is provided so as to be rotatable relative to the lower running body 2 via a slewing bearing (not shown). The upper rotating body 4 includes a machine body frame 41 (also called a slewing frame), a slewing motor 42, an engine room 43, and a control section 44. The upper rotating body 4 rotates relative to the lower running body 2 by being driven by the slewing motor 42 arranged on the machine body frame 41. The slewing motor 42 is composed of a hydraulic motor.

[0016] The machine body frame 41 is provided at the bottom of the upper rotating body 4. The machine body frame 41 is composed of cast members extending in the horizontal direction, but is not limited to this and may be composed of, for example, a plurality of metal members joined by welding or the like. The lower surface 41D (see FIG. 2) of the machine body frame 41 is included in the bottom surface portion 4D of the upper rotating body 4. In the upper rotating body 4, the portion including the bottom surface portion 4D is called the bottom portion 4a of the upper rotating body 4. Therefore, the machine body frame 41 is located at the bottom portion 4a of the upper rotating body 4.

[0017] The machine frame 41 is provided with a first opening 41a (see FIG. 2) that penetrates in the vertical direction. The first opening 41a is formed in a rectangular shape when the upper rotating body 4 is viewed from below, but is not limited thereto, and may be, for example, a square, a circle, an ellipse, or a polygonal shape other than a rectangle. Furthermore, a configuration in which a plurality of first openings 41a are provided may be used.

[0018] The engine room 43 is provided with a rear bonnet member 43B, a left bonnet member 43L, a right bonnet member (not shown), and an upper wall portion 45. The rear bonnet member 43B forms a side wall on the rear side of the engine room 43. The rear bonnet member 43B is formed of a metal plate-shaped member.

[0019] The left bonnet member 43L and the right bonnet member described above constitute the left and right side walls of the engine room 43. The left bonnet member 43L is fixed to the aircraft frame 41 and a rear bonnet support part 103 (see FIG. 5), which will be described later. The right bonnet member is also fixed to the aircraft frame 41 and the rear bonnet support part 103. The left bonnet member 43L and the right bonnet member are fixed to the aircraft frame 41 via a support member (not shown). The left bonnet member 43L and the right bonnet member are made of a metal plate-shaped member.

[0020] An outer surface 43L1 of the left bonnet member 43L is included in the left side surface portion 4L of the upper rotating body 4. In the upper rotating body 4, a portion including a side surface portion (e.g., the left side surface portion 4L) is referred to as a side portion 4b of the upper rotating body 4. Therefore, the left bonnet member 43L is located in the side portion 4b of the upper rotating body 4.

[0021] The left bonnet member 43L is provided with a second opening 43L2 penetrating in the left-right direction. The second opening 43L2 is formed in a rectangular shape when the upper rotating body 4 is viewed from the left, but is not limited thereto, and may be, for example, a square, a circle, an ellipse, or a polygonal shape other than a rectangle. Also, a configuration in which a plurality of second openings 43L2 are provided may be provided.

[0022] The upper wall portion 45 constitutes an upper wall of the engine room 43. The upper wall portion 45 is made of a metal plate-shaped member. The upper wall portion 45 is connected to a front bonnet support portion 102 (see FIG. 4) and a rear bonnet support portion 103 (see FIG. 5), which will be described later.

[0023] The rear bonnet member 43B, the left bonnet member 43L, the right bonnet member, and the upper wall portion 45 constitute the exterior portion 4c of the upper rotating body 4. The exterior portion 4c also includes the aircraft frame 41. The exterior portion 4c constitutes the outer peripheral surface of the upper rotating body 4. In the upper rotating body 4, the inner portion separated by the exterior portion 4c is called the interior 4e of the upper rotating body 4 (see Figure 4). The interior 4e of the upper rotating body 4 includes the space inside the engine room 43. The side of the exterior portion 4c opposite the interior 4e of the upper rotating body 4 (i.e., the outer portion separated by the exterior portion 4c) is called the exterior 4f of the upper rotating body 4 (see Figure 6).

[0024] Since the exterior part 4c is configured to include the vehicle body frame 41 and the left bonnet member 43L, the first opening 41a of the vehicle body frame 41 and the second opening 43L2 of the left bonnet member 43L are also included in the exterior part 4c. In other words, the first opening 41a and the second opening 43L2 are provided in the exterior part 4c.

[0025] A battery unit BU (also referred to as a high-voltage battery) and a hydraulic pump 61 (see FIG. 3) are housed in the engine room 43. That is, the hydraulic excavator 1 has the battery unit BU and the hydraulic pump 61 inside 4e of the upper rotating body 4. The battery unit BU is formed of, for example, a lithium-ion battery, and stores power for driving the electric motor EM (see FIG. 3). The battery unit BU may be formed by unitizing a plurality of batteries, or may be formed of a single battery cell. In addition, a power feed port (not shown) is provided on the upper rotating body 4. The battery unit BU can be charged by connecting the power feed port to an external power source (not shown).

[0026] The hydraulic pump 61 is driven by an electric motor EM and discharges hydraulic oil. The hydraulic oil (pressurized oil) is supplied to hydraulic motors (e.g., the left and right travel motors 22, the swing motor 42) and hydraulic cylinders (e.g., the blade cylinder 23a, the boom cylinder 31a, the arm cylinder 32a, the bucket cylinder 33a). The hydraulic motors and hydraulic cylinders that are driven by the supply of hydraulic oil from the hydraulic pump 61 are collectively referred to as hydraulic actuators 63 (see FIG. 3).

[0027] The control unit 44 is provided on the upper part of the upper rotating body 4. A driver's seat 44a is arranged in the control unit 44. The driver's seat 44a is fixed to the upper surface of the upper wall portion 45. A plurality of control members 44b are arranged around the driver's seat 44a. The plurality of control members 44b include levers, switches, pedals, etc. An operator sits on the driver's seat 44a and operates the plurality of control members 44b to drive the hydraulic actuator 63. This allows the lower traveling body 2 to travel, the blade 23 to perform ground leveling work, the work machine 3 to perform excavation work, the upper rotating body 4 to rotate, etc.

[0028] The hydraulic excavator 1 may be configured to use, as the actuator, a hydraulic actuator 63 in combination with an electric actuator driven by electricity. The electric actuator includes, for example, an electric travel motor, an electric swing motor, and an electric cylinder.

[0029] [2. Electrical and hydraulic system configuration] Fig. 3 is a block diagram showing a schematic configuration of an electrical system and a hydraulic system of the hydraulic excavator 1. In Fig. 3, wiring through which an electrical signal or current flows is shown by solid lines, and oil paths through which hydraulic oil flows are shown by dashed lines.

[0030] 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 low-voltage 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, the low-voltage battery 56, and the system controller 57 are collectively referred to as electrical equipment EP. The electrical equipment EP is accommodated in the engine room 43 (see FIGS. 4 to 7). That is, the hydraulic excavator 1 has the electrical equipment EP in the interior 4e of the upper rotating body 4.

[0031] Each device included in the electrical equipment EP is directly connected to the battery unit BU, or is electrically connected to the battery unit BU via another device included in the electrical equipment EP. For example, the PDU 53 included in the electrical equipment EP is directly connected to the battery unit BU. Also, the inverter 52 included in the electrical equipment EP is electrically connected to the battery unit BU via a junction box 54, which is another device included in the electrical equipment EP.

[0032] The electric motor EM is driven by power supplied from the battery unit BU via a junction box 54 and an inverter 52. The electric motor EM is configured as a synchronous motor, an induction motor, or the like. The electric motor EM is housed in the engine room 43 (see Figs. 5 to 7). That is, the hydraulic excavator 1 has the electric motor EM in the interior 4e of the upper rotating body 4.

[0033] The charger 51 (also called a power supply device) converts the AC voltage supplied from the external power source 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. This drives the electric motor EM. The supply of the AC voltage from the inverter 52 to the electric motor EM is performed based on a drive command output from a system controller 57.

[0034] The PDU 53 is a battery control unit that controls an internal battery relay to control input and output of the battery unit BU. The junction box 54 includes 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. The voltage output from the battery unit BU is supplied to the inverter 52 via the PDU 53 and the junction box 54.

[0035] The DC-DC converter 55 (also simply called a converter) steps down a high voltage (e.g., 48 V) direct current voltage supplied from the battery unit BU via the junction box 54 to a low voltage (e.g., 12 V). That is, the DC-DC converter 55 is electrically connected to the battery unit BU. The low-voltage battery 56 is formed of, for example, a lead battery. The low-voltage battery 56 is connected to the DC-DC converter 55 and stores the power that is stepped down and output by the DC-DC converter 55. Therefore, the low-voltage battery 56 outputs a voltage lower than that of the battery unit BU.

[0036] The low DC voltage output from the DC-DC converter 55 and the low-voltage battery 56 is supplied to a system controller 57, a drive section for a fan 71 (see FIG. 4 ) described later, etc. The system controller 57 is configured as an electronic control unit also called an ECU (Electronic Control Unit). The system controller 57 electrically controls each section of the hydraulic excavator 1.

[0037] A plurality of hydraulic pumps 61 are connected to a 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. In FIG. 3, only one hydraulic pump 61 is illustrated as an example. Each hydraulic pump 61 is connected to a hydraulic oil tank 65 that stores hydraulic oil. When the hydraulic pump 61 is driven by the electric motor EM, the hydraulic oil in the hydraulic oil tank 65 is supplied to the hydraulic actuator 63 via the control valve 62. This drives the hydraulic actuator 63. The control valve 62 is a directional switching valve that controls the flow direction and flow rate of the hydraulic oil supplied to the hydraulic actuator 63.

[0038] A heat exchanger 64 (also called an oil cooler) is provided in an oil passage connecting the control valve 62 and the hydraulic oil tank 65. Hydraulic oil that has generated heat as the hydraulic actuator 63 is driven flows into the heat exchanger 64 via the control valve 62. The heat exchanger 64 cools the hydraulic oil by exchanging heat with air (wind) that hits the heat exchanger 64. In other words, the heat exchanger 64 cools the hydraulic oil that is discharged from the hydraulic pump 61 and generates heat as the hydraulic actuator 63 is driven.

[0039] [3. Internal structure of engine room] 4 and 5 are perspective views from the left front and left rear showing the internal configuration of the engine room 43. The engine room 43 has a bonnet support part 101. The bonnet support part 101 supports the rear bonnet member 43B (see FIG. 1), the left bonnet member 43L (see FIG. 1), and the right bonnet member. The bonnet support part 101 is configured to include an upper wall part 45, a front bonnet support part 102, and a rear bonnet support part 103.

[0040] As shown in FIG. 4, the front bonnet support part 102 is disposed on the front side of the engine room 43. The front bonnet support part 102 has a vertical plate 102a and a mounting plate 102b. The vertical plate 102a is formed by bending an upper end of a metal plate-shaped member extending in the vertical direction obliquely backward and a lower end forward. The upper end of the vertical plate 102a is joined to the front end of the upper wall part 45 by welding. The lower end of the vertical plate 102a is connected to a support pillar part 104 by a fastening member such as a bolt. The lower end of the support pillar part 104 is connected to the aircraft frame 41. The front bonnet support part 102 is supported on the aircraft frame 41 by the support pillar part 104.

[0041] The mounting plate 102b is formed by bending forward the left and right ends of a metal plate-shaped member extending in the left-right direction. Each bent end is connected to the rear surface of the vertical plate 102a. The mounting plate 102b is provided with a plurality of mounting holes (not shown) penetrating in the front-rear direction. The system controller 57 is fixed to the above mounting holes with fastening members such as bolts. The vertical plate 102a is provided with a through-hole portion (not shown) penetrating in the front-rear direction at a position corresponding to the system controller 57.

[0042] As shown in FIG. 5, the rear bonnet support part 103 is disposed on the rear side of the engine room 43. The rear bonnet support part 103 has a left side plate part 103a, a right side plate part 103b, and a stay 103c. The left side plate part 103a and the right side plate part 103b are each formed of a metal plate-like member extending in the vertical direction. The left side plate part 103a and the right side plate part 103b have their upper ends connected to an upper plate part (not shown) extending in the horizontal direction. The upper plate part is joined to the upper wall part 45 by welding. The left side plate part 103a and the right side plate part 103b have their lower ends connected to the aircraft frame 41.

[0043] A stay 103c is provided on the left side surface of the left side plate portion 103a. The stay 103c is configured by bending forward the left end of a metallic plate-like member extending in the left-right direction. The DC-DC converter 55 is located in front of the stay 103c. A support bracket 105 is attached to the rear surface of the DC-DC converter 55. The support bracket 105 is configured of a metallic plate-like member extending in the up-down direction, and is connected to the stay 103c. Therefore, the rear surface of the DC-DC converter 55 is fixed to the stay 103c via the support bracket 105. In other words, the DC-DC converter 55 is supported from the rear.

[0044] Next, the arrangement of the internal configuration of the engine room 43, particularly the equipment (e.g., the battery unit BU, the electric motor EM, the electrical equipment EP, etc.), will be described with reference to Figs. 6 and 7. Figs. 6 and 7 are a front view and a left side view showing the arrangement of the equipment in the engine room 43. Each equipment arranged in the engine room 43 is supported on the vehicle frame 41 via a support member such as a stay (see Figs. 4 and 5), but in Figs. 6 and 7, the support member is omitted in order to clarify the arrangement position of each equipment. In addition, in Fig. 7, for convenience, the air guide section 72, which is shown in Fig. 6 and will be described later, is omitted. In Figs. 6 and 7, the vehicle frame 41 is shown cut in the up-down direction (Fig. 6) and the front-rear direction (Fig. 7) at the position of the first opening 41a in order to clarify the arrangement position of the electric motor EM relative to the first opening 41a. Similarly, FIG. 6 illustrates the left bonnet member 43L cut in the vertical direction at the position of the second opening 43L2 in order to clearly show the positions of the heat exchanger 64 and the fan 71 relative to the second opening 43L2.

[0045] As shown in Fig. 6, a first opening 41a provided in the aircraft frame 41 is located below the engine room 43. An electric motor EM is disposed inside (i.e., above) the engine room 43 relative to the first opening 41a and facing the first opening 41a. That is, the first opening 41a is located below the electric motor EM and is disposed opposite the electric motor EM. A hydraulic pump 61 is disposed to the right of the electric motor EM.

[0046] A second opening 43L2 provided in the left bonnet member 43L is located on the left side of the engine room 43. A heat exchanger 64 and a fan 71 (including a first fan 71a and a second fan 71b described below) are arranged inside the engine room 43 (i.e., on the right side) of the second opening 43L2 and facing the second opening 43L2. That is, the hydraulic excavator 1 has the heat exchanger 64 and the fan 71 in the interior 4e of the upper rotating body 4. The heat exchanger 64 and the fan 71 are arranged facing the second opening 43L2. The fan 71 is located to the right of the heat exchanger 64.

[0047] The fan 71 is configured as an electric fan, and is driven by low-voltage power supplied from the DC-DC converter 55 and the low-voltage battery 56. When the fan 71 is driven, air (outside air) is sucked (taken in) into the engine room 43. This creates a flow of air (wind) in the engine room 43.

[0048] The fans 71 include a first fan 71a and a second fan 71b arranged next to each other in the vertical direction (see also FIG. 7). The first fan 71a is arranged below the second fan 71b and facing the heat exchanger 64. Therefore, from the left, the left bonnet member 43L having the second opening 43L2, the heat exchanger 64, and the first fan 71a are arranged next to each other. In other words, the heat exchanger 64 is located between the first fan 71a and the second opening 43L2.

[0049] The second fan 71b is located above the heat exchanger 64. This allows the second fan 71b to be placed while avoiding the heat exchanger 64 being placed to the left of the second fan 71b. Therefore, the second fan 71b directly faces the second opening 43L2.

[0050] The battery unit BU is disposed to the right of the first fan 71a and the second fan 71b. An air guide section 72 is provided between the battery unit BU and the second opening 43L2. The heat exchanger 64, the first fan 71a, and the second fan 71b are disposed in the air guide section 72 (see also FIG. 8). The configuration of the air guide section 72 will be described later.

[0051] The electric motor EM is located below the battery unit BU and aligned vertically with the battery unit BU. In other words, the battery unit BU is disposed facing the electric motor EM. In addition, the system controller 57 is disposed in front of the battery unit BU. As described above, the system controller 57 is fixed to the front bonnet support portion 102.

[0052] As shown in Fig. 7, the first electrical device E1 is disposed to the left of the battery unit BU (one side in the width direction) and facing the battery unit BU. That is, the first electrical device E1 is disposed facing the battery unit BU. The first electrical device E1 includes a low-voltage battery 56. Therefore, the first electrical device E1 is electrically connected to the battery unit BU (see Fig. 3).

[0053] The DC-DC converter 55 is disposed to the left of the battery unit BU and above the first electrical device E1. That is, the DC-DC converter 55 is located on one side in the up-down direction with respect to the first electrical device E1 (low-voltage battery 56).

[0054] A charger 51 is disposed behind the battery unit BU. A second electrical device E2 is disposed below the charger 51 at a position facing the battery unit BU. That is, the second electrical device E2 is disposed facing the battery unit BU. The second electrical device E2 includes a junction box 54. Therefore, the second electrical device E2 is electrically connected to the inverter 52 (see FIG. 3).

[0055] An inverter 52 is disposed below the second electrical device E2 and facing the electric motor EM. That is, the second electrical device E2 is located above the inverter 52, and the inverter 52 is disposed facing the electric motor EM.

[0056] In the above configuration, when the fans 71 (first fan 71a, second fan 71b) are driven, air is drawn into the interior 4e of the aircraft (particularly, into the engine room 43) from the first opening 41a. The drawn air flows upward through the interior 4e of the aircraft, and is discharged to the outside 4f of the aircraft from the second opening 43L2.

[0057] That is, in this configuration, by driving the fan 71, the air sucked in from the first opening 41a can be raised and applied to the electric motor EM with priority over other devices (battery unit BU, hydraulic pump 61, heat exchanger 64). In addition, the air (wind) flowing from the first opening 41a to the second opening 43L2 inside the machine body 4e can also be applied to the other devices. Therefore, while the electric motor EM is cooled (air-cooled) with priority, the other devices arranged inside the machine body 4e can also be cooled (air-cooled).

[0058] If the electric motor EM and other devices can be air-cooled, the components (e.g., a cooling water pump) that would be required to water-cool them are not required. Therefore, for example, if the size of the machine body is the same, the arrangement space for the battery unit BU can be expanded by the amount of the arrangement space for the above-mentioned components. This makes it possible to install a larger battery unit BU, thereby increasing the battery capacity. As described above, while preferentially cooling the electric motor EM, it is possible to cool other devices arranged inside the machine body 4e as well, and it is possible to install a larger battery unit BU, thereby increasing the battery capacity.

[0059] From the viewpoint of directing the air drawn in through the first opening 41a to the electric motor EM first and cooling the electric motor EM preferentially, it is desirable that the first opening 41a be provided opposite the electric motor EM, as shown in FIG. 6.

[0060] From the viewpoint of efficiently applying the air that cools the electric motor EM to the battery unit BU as well, and efficiently cooling the battery unit BU, it is desirable to arrange the battery unit BU opposite the electric motor EM, as shown in FIG.

[0061] When the electric motor EM is disposed closer to the first opening 41a than the battery unit BU, the air drawn in through the first opening 41a hits the electric motor EM with priority over the battery unit BU. Therefore, from the viewpoint of cooling the electric motor EM with priority over the battery unit BU, it is desirable to dispose the electric motor EM below the battery unit BU as shown in FIG.

[0062] From the viewpoint of reliably realizing a configuration in which the first opening 41a provided in the exterior part 4c is located below the electric motor EM, the following configuration is preferable. That is, it is preferable that the exterior part 4c includes a machine body frame 41 located in the bottom part 4a of the machine body, and that the first opening 41a is provided in the machine body frame 41.

[0063] When the range through which air flows in the vertical direction inside the machine body 4e is expanded, it becomes possible to arrange devices that require cooling (e.g., electric motor EM, battery unit BU) side by side in the vertical direction, improving the degree of freedom in the layout of the devices. From this viewpoint, in a configuration in which the fan 71 includes a first fan 71a and a second fan 71b as shown in Fig. 6 and Fig. 7, it is desirable that the first fan 71a and the second fan 71b are arranged side by side in the vertical direction.

[0064] When the air immediately before being discharged from the second opening 43L2 hits the heat exchanger 64 and is cooled, the air (relatively high temperature air) after cooling the relatively high temperature heat exchanger 64 is directly discharged from the second opening 43L2 to the outside 4f of the machine body. This prevents the relatively high temperature air from flowing inside the machine body 4e, which would reduce the cooling efficiency of the equipment arranged inside the machine body 4e. Therefore, as shown in FIG. 6, it is desirable to place the heat exchanger 64 between the first fan 71a and the second opening 43L2.

[0065] The air flowing upward inside the machine body 4e becomes hotter as it cools the equipment. That is, inside the machine body 4e, the air is hotter on the upper side than on the lower side (i.e., downstream than upstream). Therefore, from the viewpoint of efficiently cooling the heat exchanger 64 by blowing relatively low-temperature air against it, it is desirable to dispose the first fan 71a, which mainly sends air to the heat exchanger 64, below the second fan 71b, as shown in FIG. 6.

[0066] For example, even if the heat exchanger 64 is disposed and the air discharged by the first fan 71a is weakened, it is desirable that the second fan 71b reliably discharges air from the second opening 43L2. From this viewpoint, it is desirable that the second fan 71b is disposed directly opposite the second opening 43L2, as shown in FIG.

[0067] When the air flowing inside the body 4e flows smoothly from the first opening 41a toward the second opening 43L2, the devices arranged inside the body 4e are efficiently cooled. Therefore, from the viewpoint of allowing the air to flow smoothly, the following configuration is desirable. That is, as shown in FIG. 1, in a configuration in which the exterior part 4c includes a bonnet member (the left bonnet member 43L in this embodiment) located on the side part 4b of the body, it is desirable that the second opening 43L2 is provided in the bonnet member.

[0068] A device (e.g., DC-DC converter 55) that outputs a voltage (e.g., 12 V) lower than the voltage (e.g., 48 V) output from the battery unit BU and a device (e.g., low-voltage battery 56) to which the above-mentioned low voltage is input are collectively called low-voltage devices (not shown). When the above-mentioned low-voltage devices are arranged together (in one place), for example, in maintenance work on the low-voltage devices, work can be performed by accessing one place, and the work time can be shortened. In addition, if the low-voltage devices can be arranged together in an empty space in the vertical direction inside the machine body, the above-mentioned empty space can be effectively utilized. In this regard, as shown in FIG. 7, in a configuration in which the DC-DC converter 55 and the first electrical device E1 including the low-voltage battery 56 are included in the inside 4e of the machine body, it is desirable to arrange the DC-DC converter 55 on one side in the vertical direction (upper in this embodiment) of the low-voltage battery 56 (first electrical device E1).

[0069] From the viewpoint of effectively utilizing the empty space in the left-right direction (width direction) of the battery unit BU as an arrangement space for the DC-DC converter 55, it is desirable to arrange the DC-DC converter 55 on one side in the width direction of the vehicle body (the left side in this embodiment) with respect to the battery unit BU as shown in Fig. 7. Also, from the viewpoint of effectively utilizing the empty space behind the DC-DC converter 55, it is desirable to support the DC-DC converter 55 from the rear of the vehicle body as shown in Fig. 5.

[0070] If the devices (high-voltage devices) that input and output the electric power stored in the battery unit BU can be arranged together, it is possible to connect the high-voltage devices together with a simple configuration, which is desirable in that the machine can be assembled efficiently (in a short time). For example, it is desirable to arrange the battery unit BU, electric motor EM, inverter 52, and second electrical equipment E2 (junction box 54 in this embodiment) that constitute the high-voltage equipment together inside 4e of the machine. Specifically, as shown in FIG. 7, it is desirable to arrange the inverter 52 facing the electric motor EM, and the second electrical equipment E2 facing the battery unit BU above the inverter 52.

[0071] Here, the configuration of the air guide section 72 will be described with reference to Fig. 8. Fig. 8 is a perspective view from the left front showing the configuration of the air guide section 72. The air guide section 72 has a front wall section 72a, a rear wall section 72b, and a right side wall section 72c.

[0072] The front wall 72a is formed by bending backward an upper portion 72a1 of a metal plate-like member extending in the vertical direction. A rear end 72a2 (the upper end before bending) of the curved upper portion 72a1 is connected to the rear wall 72b.

[0073] The rear wall 72b is bent so that its lower portion is shifted rearward relative to its upper portion. The lower end of the rear wall 72b is connected to the support base 73. On the support base 73, the first electrical equipment E1 including the low-voltage battery 56 is arranged behind the air guide section 72. That is, the first electrical equipment E1 is arranged opposite the air guide section 72.

[0074] The right side wall portion 72c is configured to extend in the front-rear direction and the up-down direction, and is connected to a right end portion 72a3 of the front wall portion 72a and a right end portion 72b1 of the rear wall portion 72b. Therefore, the right side wall portion 72c is located on the right side of the air guide portion 72. Therefore, the right side wall portion 72c is disposed facing the left side surface of the battery unit BU (see FIG. 6). The right side wall portion 72c is provided with a plurality of inlets (not shown) that open in a circular shape when the right side wall portion 72c (air guide portion 72) is viewed from the right. The shape of the inlets is not limited to a circle, and may be, for example, an ellipse, a rectangle, or a polygonal shape other than a rectangle.

[0075] The first fan 71a and the second fan 71b are attached to the left side of the right side wall 72c at a position corresponding to the inlet. As a result, the first fan 71a and the second fan 71b are disposed (through the inlet) at a position facing the left side surface of the battery unit BU (see FIG. 6). In other words, the first fan 71a and the second fan 71b are disposed facing the left side surface of the battery unit BU.

[0076] A heat exchanger 64 is disposed between the lower part of the front wall part 72a and the lower part of the rear wall part 72b in the front-rear direction. The heat exchanger 64 is located to the left of the fans 71 (particularly to the left of the first fan 71a). In the air guide part 72, an outlet part 72d is provided on the opposite side of the inlet part (i.e., the left side of the air guide part 72) with respect to the heat exchanger 64 and the fans 71 (the first fan 71a and the second fan 71b). The outlet part 72d is configured to include a left end part 72a4 of the front wall part 72a and a left end part 72b2 of the rear wall part 72b.

[0077] A plurality of first fixing portions 72e are provided on the right front side of the air guide portion 72. The first fixing portions 72e are fixed to the front bonnet support portion 102 (see FIG. 4) by fastening members such as bolts. Further, second fixing portions 73a are provided on the rear side of the support base portion 73. The second fixing portions 73a are fixed to the aircraft frame 41 (see FIG. 5) by fastening members such as bolts.

[0078] As shown in FIG. 6, air rising in the interior 4e of the vehicle body by driving the fans 71 (first fan 71a, second fan 71b) hits the electric motor EM and then flows near the side surface (particularly the left side surface in this embodiment) of the battery unit BU. As described above, the air guide section 72 is disposed between the second opening 43L2 and the battery unit BU, so that the air flowing near the side surface of the battery unit BU flows into the air guide section 72 from the inlet portion of the air guide section 72. The air that flows in flows from the inlet portion to the outlet portion 72d (that is, from the right to the left) in the air guide section 72. At this time, a part of the air flowing in the air guide section 72 (particularly the air flowing through the lower portion of the air guide section 72) hits the heat exchanger 64 and cools the heat exchanger 64. The air that flows out from the outlet portion 72d flows toward the second opening 43L2 and is discharged from the second opening 43L2 to the outside 4f of the vehicle body. In this way, the air guide section 72 forms a flow path through which the air flowing inside the body 4e flows from near the side surface of the battery unit BU toward the second opening 43L2.

[0079] The battery unit BU is reliably cooled when the air flowing near the battery unit BU is reliably exhausted to the outside 4f of the vehicle body by the fan 71. From the viewpoint of easily generating such an air flow, it is desirable that the fan 71 be disposed opposite to the side surface of the battery unit BU (the left side surface in this embodiment).

[0080] When the air flowing near the battery unit BU (particularly near the left side surface) is easily allowed to flow toward the second opening 43L2, the air drawn in from the first opening 41a is easily allowed to flow toward the battery unit BU, and the battery unit BU is efficiently cooled. In order to make it easier for the air flowing near the battery unit BU to flow toward the second opening 43L2, it is desirable to provide an air guide section 72 between the second opening 43L2 and the battery unit BU, as in this embodiment. In other words, it is desirable to provide the air guide section 72, which is disposed between the second opening 43L2 and the battery unit BU, in the interior 4e of the body.

[0081] If the first electrical device E1 (the low-voltage battery 56 in this embodiment) can be arranged in the empty space behind the air guide section 72 and to the left of the battery unit BU, this is desirable because the empty space can be effectively used as an arrangement space for the first electrical device E1. In this respect, as in this embodiment, it is desirable that the first electrical device E1 is arranged opposite the air guide section 72 in the front-rear direction of the vehicle body and opposite the battery unit BU in the left-right direction of the vehicle body. In other words, it is desirable that the first electrical device E1 is arranged opposite the battery unit BU and the air guide section 72.

[0082] [4. Supplementary Information] In this embodiment, the configuration in which the first opening 41a is provided directly below (completely below) the electric motor EM has been described, but the position of the first opening 41a is not limited to the above. For example, even if the first opening 41a is provided shifted forward from the position shown in Fig. 7, the effect of this embodiment can be obtained as long as the first opening 41a is located below the electric motor EM.

[0083] In this embodiment, the second opening 43L2 is provided in the left bonnet member 43L, but the second opening 43L2 may be provided in the right bonnet member. In this case, the arrangement of the devices (e.g., the heat exchanger 64, the fan 71) in the engine room 43 is reversed in the left-right direction from that of this embodiment.

[0084] As a safety measure, a protective member (e.g., a mesh) may be attached to the first opening 41a and the second opening 43L2. The protective member is provided to prevent a human hand or finger from accidentally entering the body of the machine from the outside.

[0085] In this embodiment, a configuration including two fans 71 has been described, but the configuration of the fans 71 is not limited to the above. It is sufficient that the air (air volume) required for cooling each piece of equipment (e.g., the heat exchanger 64, the electric motor EM) in the engine room 43 is secured, and the size and number of the fans 71 may be set according to the required air volume.

[0086] In this embodiment, the first electrical device E1 includes the low-voltage battery 56. However, the first electrical device E1 may include a system controller 57.

[0087] In the present embodiment, the configuration in which the second electrical device E2 includes the junction box 54 has been described. However, the second electrical device E2 may include the charger 51 or the PDU 53.

[0088] In this embodiment, the electric work machine has been described taking a hydraulic excavator 1, which is a construction machine, as an example, but the electric work machine is not limited to the hydraulic excavator 1 and may be a construction machine such as a wheel loader. Furthermore, the electric work machine may be an agricultural machine such as a combine harvester or a tractor.

[0089] [5. Notes] The hydraulic excavator 1 described in this embodiment can also be expressed as an electrically powered working machine as described in the following supplementary notes.

[0090] The motorized working machine referred to in Appendix (1) is A fuselage having a first opening and a second opening provided in an exterior portion, Inside the aircraft, A battery unit for storing power; an electric motor driven by the power supplied from the battery unit; a hydraulic pump driven by the electric motor to discharge hydraulic oil; A heat exchanger for cooling the hydraulic oil; a fan that draws air into the interior of the airframe through the first opening and exhausts the air to the exterior of the airframe through the second opening; The first opening provided in the exterior portion is located below the electric motor.

[0091] The electric working machine of appendix (2) is the electric working machine according to appendix (1), The first opening is provided opposite the electric motor.

[0092] The electric working machine of appendix (3) is an electric working machine according to appendix (1) or (2), The battery unit is disposed opposite the electric motor.

[0093] The electric working machine of appendix (4) is an electric working machine according to any one of appendix (1) to (3), The fan is disposed opposite a side surface of the battery unit.

[0094] The electric working machine of appendix (5) is an electric working machine according to any one of appendix (1) to (4), The fan includes a first fan and a second fan, The first fan and the second fan are arranged side by side in a vertical direction, The heat exchanger is disposed between the first fan and the second opening.

[0095] The electric working machine of appendix (6) is the electric working machine according to appendix (5), The second fan is disposed opposite the second opening.

[0096] The electric working machine of appendix (7) is an electric working machine according to appendix (5) or (6), The first fan is disposed below the second fan.

[0097] The electric working machine of appendix (8) is an electric working machine according to any one of appendix (1) to (7), In the interior of the airframe, The air guide portion is disposed between the second opening and the battery unit.

[0098] The electric working machine of appendix (9) is the electric working machine according to appendix (8), In the interior of the airframe, a first electrical device electrically connected to the battery unit; The first electrical device is disposed opposite the battery unit and the air guide portion.

[0099] The electric working machine of appendix (10) is the electric working machine according to appendix (9), In the interior of the airframe, a converter electrically connected to the battery unit; The first electrical device is a low voltage battery electrically connected to the converter; The converter is disposed on one side in the up-down direction with respect to the low-voltage battery.

[0100] The electric working machine of appendix (11) is the electric working machine according to appendix (10), The converter is supported from the rear of the airframe on one side in a width direction of the airframe relative to the battery unit.

[0101] The electric working machine of appendix (12) is the electric working machine according to any one of appendix (1) to (11), The electric motor is disposed below the battery unit.

[0102] The electric working machine of appendix (13) is the electric working machine according to appendix (12), In the interior of the airframe, an inverter disposed opposite the electric motor; a second electrical device electrically connected to the inverter, The second electrical device is disposed above the inverter and facing the battery unit.

[0103] The electric working machine of appendix (14) is an electric working machine according to any one of appendixes (1) to (13), the exterior portion includes an airframe frame located at a bottom of the airframe, The first opening is provided in the aircraft frame.

[0104] The electric working machine of appendix (15) is an electric working machine according to any one of appendixes (1) to (14), the exterior portion includes a bonnet member located on a side portion of the airframe, The second opening is provided in the bonnet member.

[0105] Although the embodiment of the present invention has been described above, the scope of the present invention is not limited to this, and the invention can be expanded or modified without departing from the spirit of the invention. [Industrial Applicability]

[0106] The present invention can be used in electric work machines such as construction machines and agricultural machines. [Explanation of symbols]

[0107] 1. Hydraulic excavator (electric work machine) 4. Upper rotating body (aircraft) 4a bottom 4b Side 4c Exterior part 4e internal 4f External 41 Aircraft frame 41a 1st opening 43L Left bonnet part (bonnet part) 43L2 2nd opening 52 Inverter 55 DC-DC converter (converter) 56 Low voltage battery (first electrical equipment) 61 Hydraulic Pump 64 Heat exchanger 71 Fans 71a 1st Fan 71b 2nd Fan 72 Air guide section BU Battery Unit E1 First Electrical Equipment E2 2nd electrical equipment EM Electric Motor

Claims

1. a fuselage having a first opening and a second opening provided in an exterior portion, Inside the aircraft, A battery unit for storing power; an electric motor driven by the power supplied from the battery unit; a hydraulic pump driven by the electric motor to discharge hydraulic oil; A heat exchanger for cooling the hydraulic oil; a fan that draws air into the interior of the airframe through the first opening and exhausts the air to the outside of the airframe through the second opening, The first opening provided in the exterior portion is located below the electric motor.

2. The electric work machine according to claim 1 , wherein the first opening is provided opposite the electric motor.

3. The electric work machine according to claim 1 , wherein the battery unit is disposed opposite the electric motor.

4. The electric work machine according to claim 1 , wherein the fan is disposed opposite a side surface of the battery unit.

5. The fan includes a first fan and a second fan, The first fan and the second fan are arranged next to each other in a vertical direction, The electric work machine according to claim 1 , wherein the heat exchanger is disposed between the first fan and the second opening.

6. The electric working machine according to claim 5 , wherein the second fan is disposed opposite the second opening.

7. The electric work machine according to claim 5 , wherein the first fan is disposed below the second fan.

8. In the interior of the airframe, The electric working machine according to claim 1 , further comprising an air guide portion disposed between the second opening and the battery unit.

9. In the interior of the airframe, a first electrical device electrically connected to the battery unit; The electric working machine according to claim 8 , wherein the first electrical device is disposed opposite the battery unit and the air guide portion.

10. In the interior of the airframe, a converter electrically connected to the battery unit; The first electrical device is a low voltage battery electrically connected to the converter; The electric working machine according to claim 9 , wherein the converter is disposed on one side in a vertical direction with respect to the low-voltage battery.

11. The electric work machine according to claim 10 , wherein the converter is supported from a rear of the body on one side in a width direction of the body relative to the battery unit.

12. The electric work machine according to claim 1 , wherein the electric motor is disposed below the battery unit.

13. In the interior of the airframe, an inverter disposed opposite the electric motor; a second electrical device electrically connected to the inverter, The electric working machine according to claim 12 , wherein the second electrical device is disposed above the inverter and facing the battery unit.

14. the exterior portion includes an airframe frame located at a bottom of the airframe, The electric work machine according to claim 1 , wherein the first opening is provided in the machine body frame.

15. the exterior portion includes a bonnet member located on a side portion of the airframe, The electric working machine according to claim 1 , wherein the second opening is provided in the bonnet member.

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