Electric work machine

Abstract

The invention provides an electric working machine which can preferentially cool an electric motor and also cool other equipment arranged in a machine body, and can be provided with a large battery unit to increase the battery capacity. A hydraulic shovel, which is an electric working machine, is provided with a machine body in which a first opening and a second opening are provided in an exterior portion. The interior of the machine body is provided with: a battery unit for storing power; an electric motor driven by power supplied from the battery unit; a hydraulic pump which is driven by the electric motor and discharges hydraulic oil; a heat exchanger for cooling the hydraulic oil; and a fan which sucks air into the machine body from the first opening part and discharges air out of the machine body from the second opening part. A first opening provided in the exterior portion is located below the electric motor.

Description

Technical Field

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

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

[0003] Patent Document 1: International Publication No. 2011 / 102042

[0004] However, in a small electric working machine where the installation space for devices including an electric motor, a hydraulic pump, and an oil cooler is limited, if a cooling water pump is provided to water-cool the electric motor as in Patent Document 1, the installation space for the battery unit that supplies power to the electric motor becomes narrow, and it is difficult to mount a large (high-capacity) battery unit. In addition, since the electric motor is a drive source of the hydraulic excavator and easily generates heat, it needs to be cooled preferentially compared to other devices. Summary of the Invention

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide an electric working machine that can preferentially cool an electric motor, cool other devices arranged inside the machine body, and can mount a large battery unit to increase the battery capacity.

[0006] The electric working machine according to one aspect of the present invention includes a machine body. The machine body has a first opening and a second opening in an exterior portion, and inside the machine body, there are: 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 to discharge working oil; a heat exchanger that cools the working oil; and a fan that sucks air from the first opening into the interior of the machine body and discharges the air from the second opening to the exterior of the machine body. The first opening provided in the exterior portion is located below the electric motor.

[0007] According to the above configuration, it is possible to preferentially cool the electric motor, cool other devices arranged inside the machine body, and can mount a large battery unit to increase the battery capacity. Brief Description of the Drawings

[0008] Figure 1 The left view showing a schematic configuration of a hydraulic excavator which is an example of the electric working machine according to one embodiment of the present invention.

[0009] Figure 2 The bottom view of the upper swing body of the hydraulic excavator.

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

[0011] Figure 4 is a perspective view of the interior structure of the engine room of the above upper swing body, as viewed from the left front.

[0012] Figure 5 is a perspective view of the interior structure of the engine room, as viewed from the left rear.

[0013] Figure 6 is a front view showing the arrangement of the equipment in the above engine room.

[0014] Figure 7 is a left view showing the arrangement of the above equipment.

[0015] Figure 8 is a perspective view of the structure of the air guiding part provided in the above engine room, as viewed from the left front.

[0016] Explanation of reference numerals

[0017] 1... Hydraulic excavator (electric working machine); 4... Upper swing body (machine body); 4a... Bottom; 4b... Side part; 4c... Exterior part; 4e... Interior; 4f... Exterior; 41... Machine body frame; 41a... First opening; 43L... Left engine hood member (engine hood member); 43L2... Second opening; 52... Inverter; 55... DC-DC converter (converter); 56... Low-voltage battery (first electrical equipment); 61... Hydraulic pump; 64... Heat exchanger; 71... Fan; 71a... First fan; 71b... Second fan; 72... Air guiding part; BU... Battery unit; E1... First electrical equipment; E2... Second electrical equipment; EM... Electric motor. Detailed implementation manners

[0018] The implementation manners of the present invention will be described below with reference to the drawings.

[0019] 〔1. Schematic structure of electric working machine〕

[0020] Figure 1 is a left view schematically showing the structure 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 swing body 4 (also referred to as a machine body).

[0021] Here, the directions are defined as follows. The direction facing forward for the operator (operator, driver) sitting on the driver's seat 44a disposed at the operation unit 44 of the upper revolving body 4 is defined as "front", and the opposite direction is defined as "rear". In a state where the upper revolving body 4 is not revolving relative to the lower traveling body 2 (when the revolving angle is 0 degrees), the front-rear direction of the upper revolving body 4 coincides with the front-rear direction of the lower traveling body 2. In the drawings, the hydraulic excavator 1 is shown in a state where the upper revolving body 4 is not revolving relative to the lower traveling body 2. Further, from the perspective of the operator sitting on the driver's seat 44a, the left side is defined as "left" and the right side is defined as "right". Also, the direction of gravity perpendicular to the front-rear direction and the left-right direction (also referred to as the width direction) is defined as the up-down direction, the upstream side of the direction of gravity is defined as "up", and the downstream side is defined as "down". In the drawings, as needed, the symbol "F" represents the front, the symbol "B" represents the rear, the symbol "R" represents the right side, the symbol "L" represents the left side, the symbol "U" represents the upper side, and the symbol "D" represents the lower side.

[0022] The lower traveling body 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 can drive the left and right crawlers 21 respectively to enable the hydraulic excavator 1 to move forward and backward. The traveling motor 22 is constituted by a hydraulic motor. The blade 23 for performing land leveling work is provided on the front side of the lower traveling body 2. The blade 23 is rotated by a blade cylinder 23a. The blade cylinder 23a is constituted by a hydraulic cylinder.

[0023] The working machine 3 includes an arm 31, a boom 32, and a bucket 33. By independently driving the arm 31, the boom 32, and the bucket 33, excavation work such as for sand and soil can be performed.

[0024] The arm 31 is rotated by an arm cylinder 31a. The base end portion of the arm cylinder 31a is supported at the front portion of the upper revolving body 4, and the arm cylinder 31a is movable in a telescopic manner. In the drawings, the arm cylinder 31a is arranged such that the piston rod side becomes the base end portion, but it may also be arranged such that the cylinder barrel side becomes the base end portion. The boom 32 is rotated by a boom cylinder 32a. The base end portion of the boom cylinder 32a is supported by the arm 31, and the boom cylinder 32a is movable in a telescopic manner. The bucket 33 is rotated by a bucket cylinder 33a. The base end portion of the bucket cylinder 33a is supported by the boom 32, and the bucket cylinder 33a is movable in a telescopic manner. The arm cylinder 31a, the boom cylinder 32a, and the bucket cylinder 33a are respectively constituted by hydraulic cylinders.

[0025] Refer to Figure 2 The structure of the upper revolving body 4 will be described. Figure 2It is a bottom view of the upper rotating body 4. The upper rotating body 4 is located above the lower traveling body 2 and is configured to be rotatable relative to the lower traveling body 2 via a slewing bearing (not shown). The upper rotating body 4 includes a body frame 41 (also referred to as a slewing frame), a slewing motor 42, an engine room 43, and an operation unit 44. The upper rotating body 4 rotates relative to the lower traveling body 2 by driving the slewing motor 42 disposed on the body frame 41. The slewing motor 42 is constituted by a hydraulic motor.

[0026] The body frame 41 is disposed at the lower part of the upper rotating body 4. The body frame 41 is constituted by a casting member extending in the horizontal direction, but is not limited thereto. For example, it may also be a structure including a plurality of metal members joined by welding or the like. The lower surface 41D (see Figure 2 ) of the body frame 41 is included in the bottom surface portion 4D of the upper rotating body 4. The portion of the upper rotating body 4 including the bottom surface portion 4D is referred to as the bottom portion 4a of the upper rotating body 4. Therefore, the body frame 41 is located at the bottom portion 4a of the upper rotating body 4.

[0027] A first opening 41a penetrating in the vertical direction is provided in the body frame 41 (see Figure 2 ). When observing the upper rotating body 4 from below, the first opening 41a is formed in a rectangular shape, but is not limited thereto. For example, it may also be a square, circular, elliptical, or polygonal shape other than a rectangle. In addition, it may also be a structure in which a plurality of first openings 41a are provided.

[0028] A rear engine hood member 43B, a left engine hood member 43L, a right engine hood member (not shown), and an upper wall portion 45 are provided in the engine room 43. The rear engine hood member 43B constitutes the side wall on the rear side of the engine room 43. The rear engine hood member 43B is constituted by a plate-like member made of metal.

[0029] The left engine hood member 43L and the above-mentioned right engine hood member constitute the left and right side walls of the engine room 43. The left engine hood member 43L is fixed to the body frame 41 and a rear engine hood support portion 103 (see Figure 5 ) described later. The right engine hood member is also fixed to the body frame 41 and the rear engine hood support portion 103. The left engine hood member 43L and the right engine hood member are fixed to the body frame 41 via a support member (not shown). The left engine hood member 43L and the right engine hood member are constituted by plate-like members made of metal.

[0030] The outer surface 43L1 of the left engine hood member 43L is included in the left side surface portion 4L of the upper rotating body 4. The portion of the upper rotating body 4 including the side surface portion (for example, the left side surface portion 4L) is referred to as the side portion 4b of the upper rotating body 4. Therefore, the left engine hood member 43L is located at the side portion 4b of the upper rotating body 4.

[0031] A second opening 43L2 penetrating in the left - right direction is provided in the left engine hood member 43L. When the upper rotating body 4 is viewed from the left, the second opening 43L2 is formed in a rectangular shape, but is not limited thereto. For example, it may also be a square, a circle, an ellipse, or a polygonal shape other than a rectangle. In addition, a structure in which a plurality of second openings 43L2 are provided may also be adopted.

[0032] The upper wall portion 45 constitutes the wall on the upper side of the engine room 43. The upper wall portion 45 is composed of a plate - like member made of metal. The upper wall portion 45 is connected to a front engine hood support portion 102 (refer to Figure 4 ) and a rear engine hood support portion 103 (refer to Figure 5 ).

[0033] The rear engine hood member 43B, the left engine hood member 43L, the right engine hood member, and the upper wall portion 45 constitute the exterior portion 4c of the upper rotating body 4. The exterior portion 4c further includes the body frame 41. The outer peripheral surface of the upper rotating body 4 is constituted by the exterior portion 4c. In the upper rotating body 4, the inner portion separated by the exterior portion 4c is referred to as the interior 4e of the upper rotating body 4 (refer to Figure 4 ). The interior 4e of the upper rotating body 4 includes the space inside the engine room 43. The side opposite to the interior 4e of the upper rotating body 4 with respect to the exterior portion 4c (that is, the outer portion separated by the exterior portion 4c) is referred to as the exterior 4f of the upper rotating body 4 (refer to Figure 6 ).

[0034] Since the exterior portion 4c is configured to include the body frame 41 and the left engine hood member 43L, the first opening 41a of the body frame 41 and the second opening 43L2 of the left engine hood member 43L are also included in the exterior portion 4c. That is, the first opening 41a and the second opening 43L2 are provided in the exterior portion 4c.

[0035] A battery unit BU (also referred to as a high - voltage battery) and a hydraulic pump 61 (refer to Figure 3 ) are housed in the engine room 43. That is, the hydraulic excavator 1 has the battery unit BU and the hydraulic pump 61 in the interior 4e of the upper rotating body 4. The battery unit BU is constituted by, for example, a lithium - ion battery and stores electric power for driving an electric motor EM (refer to Figure 3 ). The battery unit BU may be constituted by combining a plurality of battery units or may be constituted by a single cell. In addition, a power supply port (not shown) is provided in the upper rotating body 4. By connecting the above - mentioned power supply port to an external power source (not shown), the battery unit BU can be charged.

[0036] The hydraulic pump 61 is driven by the electric motor EM to discharge the working oil. The above-mentioned working oil (pressure oil) is supplied to hydraulic motors (such as the left and right traveling motors 22 and the swing motor 42) and hydraulic cylinders (such as the blade cylinder 23a, the boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33a). The hydraulic motors and hydraulic cylinders that are driven by the working oil supplied from the hydraulic pump 61 are collectively referred to as hydraulic actuators 63 (refer to Figure 3 ).

[0037] The operation unit 44 is provided on the upper part of the upper swing body 4. A driver's seat 44a is arranged in the operation unit 44. The driver's seat 44a is fixed to the upper surface part of the upper wall part 45. A plurality of operation members 44b are arranged around the driver's seat 44a. The plurality of operation members 44b are configured to include levers, switches, pedals, etc. By the operator sitting on the driver's seat 44a and operating the plurality of operation members 44b, the hydraulic actuator 63 is driven. Thereby, the traveling of the lower traveling body 2, the land leveling operation by means of the blade 23, the excavation operation by means of the work machine 3, the swing of the upper swing body 4, etc. can be performed.

[0038] The hydraulic excavator 1 may also have a structure in which the hydraulic actuator 63 and electric actuators driven by electricity are used as actuators. The above-mentioned electric actuators include, for example, electric traveling motors, electric swing motors, and electric cylinders.

[0039] 〔2. Structure of the electrical system and hydraulic system〕

[0040] Figure 3 is a block diagram schematically showing the structure of the electrical system and hydraulic system of the hydraulic excavator 1. In addition, Figure 3 the wirings through which power supply signals or currents flow are shown by solid lines, and the oil paths through which the working oil flows are shown by dashed lines in

[0041] 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 components EP. The electrical components EP are housed in the engine room 43 (refer to Figures 4 to 7 ). That is, the hydraulic excavator 1 has the electrical components EP inside the upper swing body 4 at 4e.

[0042] Each device included in the electrical device EP is directly connected to the battery unit BU, or is electrically connected to the battery unit BU via other devices included in the electrical device EP. For example, the PDU 53 included in the electrical device EP is directly connected to the battery unit BU. In addition, the inverter 52 included in the electrical device EP is electrically connected to the battery unit BU via the junction box 54, which is another device included in the electrical device EP.

[0043] The electric motor EM is driven by electric power supplied from the battery unit BU via the junction box 54 and the inverter 52. The electric motor EM is composed of a synchronous motor, an induction motor, or the like. The electric motor EM is housed in the engine room 43 (see Figures 5 to 7 ). That is, the hydraulic excavator 1 has the electric motor EM inside the upper swing body 4 at 4e.

[0044] The charger 51 (also called a power supply) converts the AC voltage supplied from the external power source described above 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. Thereby, the electric motor EM is driven. The supply of the AC voltage from the inverter 52 to the electric motor EM is performed based on a drive command output from the system controller 57.

[0045] The PDU 53 is a battery control unit that controls the internal battery relay and controls the input and output of the battery unit BU. The junction box 54 is configured to include a charger relay, an inverter relay, a fuse, and the like. The voltage output from the charger 51 is supplied to the battery unit BU via the junction box 54 and the PDU 53. In addition, the voltage output from the battery unit BU is supplied to the inverter 52 via the PDU 53 and the junction box 54.

[0046] The DC-DC converter 55 (also simply referred to as a converter) steps down the high-voltage (e.g., 48V) DC voltage supplied from the battery unit BU via the junction box 54 to a low voltage (e.g., 12V). That is, the DC-DC converter 55 is electrically connected to the battery unit BU. The low-voltage battery 56 is composed of a lead battery, for example. The low-voltage battery 56 is connected to the DC-DC converter 55 and stores the electric power 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.

[0047] The low-voltage DC voltage output from the DC-DC converter 55 and the low-voltage battery 56 is supplied to the system controller 57, the drive unit of the fan 71 described later (see Figure 4 ), and the like. The system controller 57 is composed of an electronic control unit also called an ECU (Electronic Control Unit). The system controller 57 performs electrical control of each part of the hydraulic excavator 1.

[0048] A plurality of hydraulic pumps 61 are connected to the rotating shaft (output shaft) of the electric motor EM. The plurality of hydraulic pumps 61 include a variable displacement pump and a fixed displacement pump. Figure 3 In Figure 3 , only one hydraulic pump 61 is illustrated as an example. Each hydraulic pump 61 is connected to a working oil tank 65 that stores working oil. When the hydraulic pump 61 is driven by the electric motor EM, the working oil in the working oil tank 65 is supplied to the hydraulic actuator 63 via the control valve 62. Thereby, the hydraulic actuator 63 is driven. The control valve 62 is a direction switching valve that controls the flow direction and flow rate of the working oil supplied to the hydraulic actuator 63.

[0049] A heat exchanger 64 (also referred to as an oil cooler) is provided in the oil passage connected to the control valve 62 and the working oil tank 65. The working oil that has become hot along with the driving of the hydraulic actuator 63 flows into the heat exchanger 64 via the control valve 62. The heat exchanger 64 cools the working oil by exchanging heat with the air (wind) blown onto the heat exchanger 64. That is, the heat exchanger 64 cools the working oil discharged from the hydraulic pump 61 and heated due to the driving of the hydraulic actuator 63.

[0050] 〔3. Internal Structure of Engine Compartment〕

[0051] Figure 4 and Figure 5 are a perspective view observed from the left front and a perspective view observed from the left rear showing the internal structure of the engine compartment 43. The engine compartment 43 has an engine hood support portion 101. The engine hood support portion 101 supports the rear engine hood member 43B (refer to Figure 1 ), the left engine hood member 43L (refer to Figure 1 ), and the above-mentioned right engine hood member. The engine hood support portion 101 is configured to include an upper wall portion 45, a front engine hood support portion 102, and a rear engine hood support portion 103.

[0052] As Figure 4 shown, the front engine hood support portion 102 is disposed on the front side of the engine compartment 43. The front engine hood support portion 102 has a vertical plate 102a and a mounting plate 102b. The vertical plate 102a is formed by bending the upper end portion of a metal plate-like member extending in the vertical direction obliquely rearward and bending the lower end portion forward. The upper end portion of the vertical plate 102a is joined to the front end portion of the upper wall portion 45 by welding. The lower end portion of the vertical plate 102a is connected to the support column portion 104 by fastening members such as bolts. The lower end portion of the support column portion 104 is connected to the body frame 41. The front engine hood support portion 102 is supported on the body frame 41 via the support column portion 104.

[0053] The mounting plate 102b is formed by bending the left and right end portions of a metal plate-like member extending in the left-right direction forward. Each of the bent end portions is connected to the rear surface portion of the vertical plate 102a. A plurality of mounting holes (not shown) penetrating in the front-rear direction are provided in the mounting plate 102b. The system controller 57 is fixed to the mounting holes by fastening members such as bolts. Further, in the vertical plate 102a, a through-hole portion (not shown) penetrating in the front-rear direction is provided at a position corresponding to the system controller 57.

[0054] As Figure 5 shown, the rear hood support portion 103 is disposed on the rear side of the engine compartment 43. The rear hood support portion 103 has a left side plate portion 103a, a right side plate portion 103b, and a brace 103c. The left side plate portion 103a and the right side plate portion 103b are each formed of a metal plate-like member extending in the up-down direction. The upper end portions of the left side plate portion 103a and the right side plate portion 103b are connected to an upper plate portion (not shown) extending in the left-right direction. The upper plate portion is joined to the upper wall portion 45 by welding. The lower end portions of the left side plate portion 103a and the right side plate portion 103b are connected to the body frame 41.

[0055] The brace 103c is provided on the left surface portion of the left side plate portion 103a. The brace 103c is formed by bending the left end portion of a metal plate-like member extending in the left-right direction forward. The DC-DC converter 55 is disposed in front of the brace 103c. The support bracket 105 is mounted on the rear surface portion of the DC-DC converter 55. The support bracket 105 is formed of a metal plate-like member extending in the up-down direction and is connected to the brace 103c. Accordingly, the rear surface portion of the DC-DC converter 55 is fixed to the brace 103c via the support bracket 105. That is, the DC-DC converter 55 is supported from the rear.

[0056] Next, based on Figure 6 and Figure 7 the internal structure of the engine compartment 43, particularly the arrangement of devices (such as the battery unit BU, the electric motor EM, the electrical device EP, etc.) will be described. Figure 6 and Figure 7 are a front view and a left view showing the arrangement of devices in the engine compartment 43. Each device disposed in the engine compartment 43 is supported on the body frame 41 via support members such as braces (see Figure 4 and Figure 5 ). In Figure 6 and Figure 7 , for the sake of clarity of the arrangement positions of the respective devices, the support members are not shown. Further, in Figure 7 , for convenience, the illustration of the air guide portion 72 described later shown in Figure 6 is omitted. Figure 6 and Figure 7In order to clarify the arrangement position of the electric motor EM relative to the first opening 41a, the body frame 41 cut along the vertical direction ( Figure 6 ) and the front-rear direction ( Figure 7 ) at the position of the first opening 41a is shown. Similarly, Figure 6 In order to clarify the arrangement positions of the heat exchanger 64 and the fan 71 relative to the second opening 43L2, the left engine hood member 43L cut along the vertical direction at the position of the second opening 43L2 is shown.

[0057] As Figure 6 shown, the first opening 41a provided in the body frame 41 is located on the lower side of the engine compartment 43. Inside the engine compartment 43 (i.e., the upper side) relative to the first opening 41a, the electric motor EM is arranged at a position opposite to the first opening 41a. That is, the first opening 41a is located at a position lower than the electric motor EM and is provided opposite to the electric motor EM. The hydraulic pump 61 is arranged on the right side of the electric motor EM.

[0058] The second opening 43L2 provided in the left engine hood member 43L is located on the left side of the engine compartment 43. Inside the engine compartment 43 (i.e., the right side) relative to the second opening 43L2, the heat exchanger 64 and the fan 71 (including the first fan 71a and the second fan 71b described later) are arranged at positions opposite to the second opening 43L2. That is, the hydraulic excavator 1 has the heat exchanger 64 and the fan 71 inside the upper swing body 4 (4e). In addition, the heat exchanger 64 and the fan 71 are arranged to be opposite to the second opening 43L2. The fan 71 is located at a position to the right of the heat exchanger 64.

[0059] The fan 71 is composed of an electric fan and is driven by low-voltage electric power supplied from the DC-DC converter 55 and the low-voltage battery 56. When the fan 71 is driven, air (external air) is sucked into (obtained) the engine compartment 43. Thereby, the flow of air (wind) is formed in the engine compartment 43.

[0060] The fan 71 includes the first fan 71a and the second fan 71b arranged in parallel in the vertical direction (also refer to Figure 7 ). The first fan 71a is arranged opposite to the heat exchanger 64 below the second fan 71b. Therefore, the left engine hood member 43L having the second opening 43L2, the heat exchanger 64, and the first fan 71a are arranged in parallel in sequence from the left. That is, the heat exchanger 64 is located between the first fan 71a and the second opening 43L2.

[0061] The second fan 71b is located above the heat exchanger 64. Thereby, it is possible to avoid arranging the second fan 71b with the heat exchanger 64 disposed to the left of the second fan 71b. Therefore, the second fan 71b directly faces the second opening 43L2.

[0062] The battery unit BU is arranged at a position to the right of the first fan 71a and the second fan 71b. In addition, a wind guide portion 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 arranged within the wind guide portion 72 (also refer to Figure 8 ). In addition, the structure of the wind guide portion 72 will be described later.

[0063] Below the battery unit BU, an electric motor EM is arranged at a position juxtaposed with the battery unit BU in the vertical direction. That is, the battery unit BU and the electric motor EM are arranged opposite to each other. In addition, a system controller 57 is arranged in front of the battery unit BU. As described above, the system controller 57 is fixed to the front hood support portion 102.

[0064] As Figure 7 shown, a first electrical device E1 is arranged at a position to the left (one side in the width direction) of the battery unit BU and opposite to the battery unit BU. That is, the first electrical device E1 and the battery unit BU are arranged opposite to each other. 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 (refer to Figure 3 ).

[0065] A DC-DC converter 55 is arranged at a position 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 vertical direction with respect to the first electrical device E1 (low-voltage battery 56).

[0066] A charger 51 is arranged at a position behind the battery unit BU. Below the charger 51, a second electrical device E2 is arranged at a position opposite to the battery unit BU. That is, the second electrical device E2 and the battery unit BU are arranged opposite to each other. The second electrical device E2 includes a junction box 54. Therefore, the second electrical device E2 is electrically connected to the inverter 52 (refer to Figure 3 ).

[0067] An inverter 52 is arranged below the second electrical device E2 and opposite to the electric motor EM. That is, the second electrical device E2 is located above the inverter 52, and the inverter 52 and the electric motor EM are arranged opposite to each other.

[0068] In the above structure, if the driving fan 71 (the first fan 71a and the second fan 71b) is driven, air is inhaled from the first opening 41a into the interior 4e of the body (especially into the engine room 43). The inhaled air rises and flows inside the body 4e and is discharged to the outside 4f of the body from the second opening 43L2.

[0069] That is, in this structure, by driving the fan 71, the air inhaled from the first opening 41a can be made to rise and blown to the electric motor EM preferentially over other devices (the battery unit BU, the hydraulic pump 61, and the heat exchanger 64). In addition, the air (wind) flowing from the first opening 41a toward the second opening 43L2 inside the body 4e can also be blown to other devices. Therefore, the electric motor EM can be preferentially cooled (air-cooled), and other devices arranged inside the body 4e can also be cooled (air-cooled).

[0070] If the electric motor EM and other devices can be air-cooled, components (such as a cooling water pump) required for water-cooling these devices are not needed. Therefore, for example, if the body size is the same, the arrangement space of the battery unit BU can be expanded by an amount corresponding to the arrangement space of the above components. Therefore, a larger battery unit BU can be provided to increase the battery capacity. Thus, the electric motor EM can be preferentially cooled and other devices arranged inside the body 4e can also be cooled, and a larger battery unit BU can be provided to increase the battery capacity.

[0071] From the viewpoint of first blowing the air inhaled from the first opening 41a to the electric motor EM to preferentially cool the electric motor EM, it is preferably as shown in Figure 6 that the first opening 41a is arranged to face the electric motor EM.

[0072] From the viewpoint of also efficiently blowing the air that cools the electric motor EM to the battery unit BU to efficiently cool the battery unit BU, it is preferably as shown in Figure 6 that the battery unit BU is arranged to face the electric motor EM.

[0073] If the electric motor EM is arranged closer to the first opening 41a than the battery unit BU, the air inhaled from the first opening 41a is blown to the electric motor EM preferentially over the battery unit BU. Therefore, from the viewpoint of preferentially cooling the electric motor EM over the battery unit BU, it is preferably as shown in Figure 6 that the electric motor EM is arranged below the battery unit BU.

[0074] From the viewpoint of reliably implementing a structure in which the first opening 41a provided in the exterior portion 4c is located below the electric motor EM, the following structure is preferred. That is, it is preferred that the exterior portion 4c includes a body frame 41 located at the bottom 4a of the body, and the first opening 41a is provided in the body frame 41.

[0075] Inside the body 4e, if the range of air flow expands in the vertical direction, a layout in which devices to be cooled (such as the electric motor EM and the battery unit BU) are arranged in parallel in the vertical direction can be achieved, and the degree of freedom in the layout of the devices is increased. From this viewpoint, it is preferred that, as shown in Figure 6 and Figure 7 in the structure where the fan 71 includes a first fan 71a and a second fan 71b, the first fan 71a and the second fan 71b are arranged in parallel in the vertical direction.

[0076] If the air just before being discharged from the second opening 43L2 is blown onto the heat exchanger 64 for cooling, the air (relatively high-temperature air) after cooling the relatively high-temperature heat exchanger 64 is immediately discharged to the outside 4f of the body from the second opening 43L2. Thus, it is possible to prevent the relatively high-temperature air from flowing inside the body 4e and reducing the cooling efficiency of the devices arranged inside the body 4e. Therefore, it is preferred that, as shown in Figure 6 the heat exchanger 64 is arranged between the first fan 71a and the second opening 43L2.

[0077] The air rising inside the body 4e becomes high-temperature as it cools the devices. That is, inside the body 4e, the temperature of the air on the upper side (i.e., the downstream side compared to the upstream side) is higher than that on the lower side. Therefore, from the viewpoint of efficiently cooling the heat exchanger 64 by blowing relatively low-temperature air, it is preferred that, as shown in Figure 6 the first fan 71a that mainly supplies air to the heat exchanger 64 is arranged below the second fan 71b.

[0078] For example, it is preferred that even if the heat exchanger 64 is arranged and the discharge of air promoted by the first fan 71a becomes weak, air can be reliably discharged from the second opening 43L2 through the second fan 71b. From this viewpoint, it is preferred that, as shown in Figure 6 the second fan 71b is arranged directly opposite the second opening 43L2.

[0079] If 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 enabling smooth air flow, the following structure is preferred. That is, it is preferred that, as shown in Figure 1As shown, in the structure where the exterior part 4c includes a hood member (the left hood member 43L in this embodiment) located on the side part 4b of the machine body, a second opening 43L2 is provided in the hood member.

[0080] Devices (such as the DC-DC converter 55) that output a voltage (e.g., 12V) lower than the voltage (e.g., 48V) output from the battery unit BU, and devices (such as the low-voltage battery 56) that are input with the above low voltage are collectively referred to as low-voltage devices (not shown). If the above low-voltage devices are centrally arranged (in one place), then for example, during the maintenance operation of the low-voltage devices, the operation can be carried out by approaching one place, and the operation time is shortened. In addition, as long as the low-voltage devices can be centrally arranged in the free space in the vertical direction within the machine body, the above free space can also be effectively utilized. In this regard, it is preferably as Figure 7 As shown, in the structure where the DC-DC converter 55 and the first electrical device E1 including the low-voltage battery 56 are provided in the interior 4e of the machine body, the DC-DC converter 55 is arranged on one side (the upper side in this embodiment) in the vertical direction with respect to the low-voltage battery 56 (the first electrical device E1).

[0081] From the perspective of effectively using the free space in the left-right direction (width direction) of the battery unit BU as the arrangement space for the DC-DC converter 55, it is preferably as Figure 7 As shown, the DC-DC converter 55 is arranged on one side (the left side in this embodiment) in the width direction of the machine body with respect to the battery unit BU. In addition, from the perspective of effectively using the free space behind the machine body of the DC-DC converter 55, it is preferably as Figure 5 As shown, the DC-DC converter 55 is supported from the rear of the machine body.

[0082] If devices (high-voltage devices) that are input and output with the power stored in the battery unit BU can be centrally arranged with each other, then the high-voltage devices can be connected to each other with a simple structure, which is preferable in terms of being able to efficiently (in a short time) assemble the machine body. For example, it is preferably to centrally arrange the battery unit BU, the electric motor EM, the inverter 52, and the second electrical device E2 (the junction box 54 in this embodiment) that constitute the high-voltage devices in the interior 4e of the machine body. Specifically, it is preferably as Figure 7 As shown, the inverter 52 is arranged to face the electric motor EM, and the second electrical device E2 is arranged above the inverter 52 and arranged to face the battery unit BU.

[0083] Here, based on Figure 8 The structure of the air guide part 72 will be described. Figure 8It is a perspective view of the structure of the air guide part 72 as viewed from the left front. The air guide part 72 has a front wall part 72a, a rear wall part 72b, and a right side wall part 72c.

[0084] The front wall part 72a is formed by bending the upper part 72a1 of a plate-like member made of metal extending in the vertical direction backward. The rear end part 72a2 (the upper end part before bending) of the bent upper part 72a1 is connected to the rear wall part 72b.

[0085] The rear wall part 72b is formed by bending the lower part so as to be in a position offset backward with respect to the upper part. The lower end part of the rear wall part 72b is connected to the support table part 73. On the support table part 73, the first electrical equipment E1 including the low-voltage battery 56 is arranged in parallel behind the air guide part 72. That is, the first electrical equipment E1 is arranged to face the air guide part 72.

[0086] The right side wall part 72c is configured to extend in the front-rear direction and the vertical direction, and is connected to the right end part 72a3 of the front wall part 72a and the right end part 72b1 of the rear wall part 72b. Therefore, the right side wall part 72c is located on the right side of the air guide part 72. Therefore, the right side wall part 72c is arranged to face the left side surface of the battery unit BU (see Figure 6 ). When the right side wall part 72c (the air guide part 72) is viewed from the right, a plurality of circularly opened inlet parts (not shown) are provided on the right side wall part 72c. The shape of the above inlet part is not limited to a circle, and may be, for example, an ellipse, a rectangle, or a polygonal shape other than a rectangle.

[0087] On the left side of the right side wall part 72c, the first fan 71a and the second fan 71b are installed at positions corresponding to the above inlet parts. Thus, the first fan 71a and the second fan 71b are arranged at positions facing the left side surface of the battery unit BU (via the inlet parts) (see Figure 6 ). That is, the first fan 71a and the second fan 71b are arranged to face the left side surface of the battery unit BU.

[0088] A heat exchanger 64 is arranged 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 fan 71 (especially to the left of the first fan 71a). In the air guide part 72, an outlet part 72d is provided on the side opposite to the inlet part with respect to the heat exchanger 64 and the fan 71 (the first fan 71a, the second fan 71b) (that is, on the left side of the air guide part 72). The outlet part 72d is configured to include the left end part 72a4 of the front wall part 72a and the left end part 72b2 of the rear wall part 72b.

[0089] A plurality of first fixing parts 72e are provided on the right front side of the air guide part 72. The first fixing parts 72e are supported by bolts and other fastening parts with respect to the front engine hood support part 102 (seeFigure 4 ) Fixed. In addition, a second fixing portion 73a is provided on the rear side of the support table portion 73. The second fixing portion 73a is fixed to the machine body frame 41 (refer to Figure 5 ) by fastening members such as bolts.

[0090] As Figure 6 shown, the air rising inside the machine body 4e by the drive of the fan 71 (the first fan 71a and the second fan 71b) is blown onto the electric motor EM and then flows near the side surface of the battery unit BU (specifically, the left side surface in this embodiment). As described above, since the air guiding portion 72 is disposed between the second opening 43L2 and the battery unit BU, the air flowing near the side surface of the battery unit BU flows into the air guiding portion 72 from the inlet portion of the air guiding portion 72. The inflowed air flows from the inlet portion toward the outlet portion 72d (that is, from the right side toward the left side) inside the air guiding portion 72. At this time, a part of the air flowing inside the air guiding portion 72 (specifically, the air flowing in the lower portion of the air guiding portion 72) blows onto the heat exchanger 64 to cool the heat exchanger 64. The air flowing out from the outlet portion 72d flows toward the second opening 43L2 and is discharged to the outside 4f of the machine body from the second opening 43L2. In this way, the air guiding portion 72 constitutes a flow path for the air flowing inside the machine body 4e to flow from near the side surface of the battery unit BU toward the second opening 43L2.

[0091] If the air flowing near the battery unit BU is reliably discharged to the outside 4f of the machine body by the fan 71, the battery unit BU is reliably cooled. From the viewpoint of easily generating such an air flow, it is preferable that the fan 71 is arranged to face the side surface of the battery unit BU (the left side surface in this embodiment).

[0092] If the air flowing near the battery unit BU (especially near the left side surface) easily flows toward the second opening 43L2, the air inhaled from the first opening 41a easily flows toward the battery unit BU, and the battery unit BU is efficiently cooled. In order to make the air flowing near the battery unit BU easily flow toward the second opening 43L2, it is preferable to provide the air guiding portion 72 between the second opening 43L2 and the battery unit BU as in this embodiment. That is, it is preferable to provide the air guiding portion 72 disposed between the second opening 43L2 and the battery unit BU inside the machine body 4e.

[0093] If it is possible to arrange the first electrical device E1 (in this embodiment, the low-voltage battery 56) in the free space behind the air guide portion 72 and to the left of the battery unit BU, it is preferable in that the above free space can be effectively used as the arrangement space for the first electrical device E1. In this regard, it is preferable that, as in this embodiment, the first electrical device E1 is arranged to face the air guide portion 72 in the front-rear direction of the machine body and is arranged to face the battery unit BU in the left-right direction of the machine body. That is, it is preferable that the first electrical device E1 is arranged to face the battery unit BU and the air guide portion 72.

[0094] 〔4. Supplementary〕

[0095] In this embodiment, the structure 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 when the first opening 41a is arranged to be offset forward from the position shown Figure 7 as long as the first opening 41a is located below the electric motor EM, the effects of this embodiment can be obtained.

[0096] In this embodiment, the structure in which the second opening 43L2 is provided in the left engine hood member 43L has been described, but the second opening 43L2 may also be provided in the right engine hood member. In this case, the arrangement of each device (e.g., the heat exchanger 64, the fan 71) in the engine room 43 is the arrangement opposite to that in this embodiment in the left-right direction.

[0097] As a safety measure, a protection member (e.g., a net) may also be installed in the first opening 41a and the second opening 43L2. The above protection member is provided to prevent a person's hand or finger from mistakenly reaching into the machine body from the outside.

[0098] In this embodiment, the structure having two fans 71 has been described, but the structure of the fan 71 is not limited to the above. As long as the air (air volume) required for cooling each device (e.g., the heat exchanger 64, the electric motor EM) in the engine room 43 is ensured, the size and number of the fans 71 can be set according to the required air volume.

[0099] In this embodiment, the structure in which the first electrical device E1 includes the low-voltage battery 56 has been described, but the first electrical device E1 may also include the system controller 57.

[0100] In this embodiment, the structure in which the second electrical device E2 includes the junction box 54 has been described, but the second electrical device E2 may also include the charger 51 or may include the PDU 53.

[0101] In the present embodiment, as an electric working machine, a hydraulic excavator 1 as a construction machine is taken as an example for explanation. However, the electric working machine is not limited to the hydraulic excavator 1, and may also be a construction machine such as a wheel loader. In addition, the electric working machine may also be an agricultural machine such as a combine harvester or a tractor.

[0102] [5. Supplementary Note]

[0103] The hydraulic excavator 1 described in the present embodiment can also be expressed as an electric working machine shown in the following supplementary note.

[0104] The electric working machine of Supplementary Note (1) includes a machine body.

[0105] A first opening and a second opening are provided in the exterior portion of the machine body.

[0106] Inside the machine body, there are:

[0107] A battery unit that stores electric power;

[0108] An electric motor that is driven by the electric power supplied from the battery unit;

[0109] A hydraulic pump that is driven by the electric motor to discharge working oil;

[0110] A heat exchanger that cools the working oil; and

[0111] A fan that sucks air from the first opening into the interior of the machine body and discharges the air from the second opening to the exterior of the machine body.

[0112] The first opening provided in the exterior portion is located below the electric motor.

[0113] The electric working machine of Supplementary Note (2) is configured based on the electric working machine described in Supplementary Note (1),

[0114] The first opening is provided to face the electric motor.

[0115] The electric working machine of Supplementary Note (3) is configured based on the electric working machine described in Supplementary Note (1) or (2).

[0116] The battery unit is arranged to face the electric motor.

[0117] The electric working machine of Supplementary Note (4) is configured based on the electric working machine described in any one of Supplementary Notes (1) to (3).

[0118] The fan is arranged to face the side surface of the battery unit.

[0119] The electric working machine in Note (5) is configured based on the electric working machine described in any one of Notes (1) to (4),

[0120] The above-mentioned fan includes a first fan and a second fan,

[0121] The above-mentioned first fan and the above-mentioned second fan are arranged side by side in the vertical direction,

[0122] The above-mentioned heat exchanger is arranged between the above-mentioned first fan and the above-mentioned second opening.

[0123] The electric working machine in Note (6) is configured based on the electric working machine described in Note (5),

[0124] The above-mentioned second fan is arranged to face the above-mentioned second opening.

[0125] The electric working machine in Note (7) is configured based on the electric working machine described in Note (5) or (6),

[0126] The above-mentioned first fan is arranged below the above-mentioned second fan.

[0127] The electric working machine in Note (8) is configured based on the electric working machine described in any one of Notes (1) to (7),

[0128] A wind guiding part is provided inside the above-mentioned body,

[0129] The above-mentioned wind guiding part is arranged between the above-mentioned second opening and the above-mentioned battery unit.

[0130] The electric working machine in Note (9) is configured based on the electric working machine described in Note (8),

[0131] A first electrical device is provided inside the above-mentioned body,

[0132] The above-mentioned first electrical device is electrically connected to the above-mentioned battery unit,

[0133] The above-mentioned first electrical device is arranged to face the above-mentioned battery unit and the above-mentioned wind guiding part.

[0134] The electric working machine in Note (10) is configured based on the electric working machine described in Note (9),

[0135] A converter is provided inside the above-mentioned body,

[0136] The above-mentioned converter is electrically connected to the above-mentioned battery unit,

[0137] The above-mentioned first electrical device includes a low-voltage battery,

[0138] The above-mentioned low-voltage battery is electrically connected to the above-mentioned converter.

[0139] The above-mentioned converter is arranged on one side in the up-down direction with respect to the above-mentioned low-voltage battery.

[0140] The electric working machine according to Note (11) is configured based on the electric working machine described in Note (10),

[0141] The above-mentioned converter is located on one side in the width direction of the above-mentioned body with respect to the above-mentioned battery unit and is supported from the rear of the above-mentioned body.

[0142] The electric working machine according to Note (12) is configured based on the electric working machine described in any one of Notes (1) to (11),

[0143] The above-mentioned electric motor is arranged below the above-mentioned battery unit.

[0144] The electric working machine according to Note (13) is configured based on the electric working machine described in Note (12),

[0145] Inside the above-mentioned body, there are:

[0146] An inverter, arranged to face the above-mentioned electric motor; and

[0147] A second electrical device, electrically connected to the above-mentioned inverter,

[0148] The above-mentioned second electrical device is above the above-mentioned inverter and is arranged to face the above-mentioned battery unit.

[0149] The electric working machine according to Note (14) is configured based on the electric working machine described in any one of Notes (1) to (13),

[0150] The above-mentioned exterior part includes a body frame, and the body frame is located at the bottom of the above-mentioned body,

[0151] The above-mentioned first opening is provided on the above-mentioned body frame.

[0152] The electric working machine according to Note (15) is configured based on the electric working machine described in any one of Notes (1) to (14),

[0153] The above-mentioned exterior part includes an engine hood component, and the engine hood component is located on the side of the above-mentioned body,

[0154] The above-mentioned second opening is provided on the above-mentioned engine hood component.

[0155] As described above, the embodiments of the present invention have been described, but the scope of the present invention is not limited thereto, and it can be implemented with expansion or modification within the scope not departing from the gist of the invention.

[0156] Industrial applicability

[0157] The present invention can be used, for example, in electric working machines such as construction machinery and agricultural machinery.

Claims

1. An electric working machine, characterized in that: it includes a machine body, and the machine body is provided with a first opening and a second opening in the exterior part; inside the machine body, there are: a battery unit for storing electric power; an electric motor driven by the electric power supplied from the battery unit; a hydraulic pump driven by the electric motor to discharge working oil; a heat exchanger for cooling the working oil; and a fan that sucks air from the first opening into the interior of the machine body and discharges the air from the second opening to the exterior of the machine body, the first opening provided in the exterior part is located at a position lower than the electric motor.

2. The electric working machine according to claim 1, characterized in that: the first opening is provided to face the electric motor.

3. The electric working machine according to claim 1, characterized in that: the battery unit is arranged to face the electric motor.

4. The electric working machine according to claim 1, characterized in that: the fan is arranged to face the side surface of the battery unit.

5. The electric working machine according to claim 1, characterized in that: the fan includes a first fan and a second fan, the first fan and the second fan are arranged in parallel in the vertical direction, the heat exchanger is arranged between the first fan and the second opening.

6. The electric working machine according to claim 5, characterized in that: the second fan is arranged to face the second opening.

7. The electric working machine according to claim 5, characterized in that: the first fan is arranged below the second fan.

8. The electric working machine according to claim 1, characterized in that: a wind guiding part is provided inside the machine body, the wind guiding part is arranged between the second opening and the battery unit.

9. The electric working machine according to claim 8, characterized in that: a first electrical device is provided inside the machine body, the first electrical device is electrically connected to the battery unit, the first electrical device is arranged to face the battery unit and the wind guiding part.

10. The electric working machine according to claim 9, characterized in that: a converter is provided inside the machine body, the converter is electrically connected to the battery unit, the first electrical device includes a low-voltage battery, the low-voltage battery is electrically connected to the converter, the converter is arranged on one side in the vertical direction with respect to the low-voltage battery.

11. The electric working machine according to claim 10, characterized in that: the converter is located on one side in the width direction of the machine body with respect to the battery unit and is supported from the rear of the machine body.

12. The electric working machine according to claim 1, characterized in that: the electric motor is arranged below the battery unit.

13. The electric working machine according to claim 12, characterized in that: inside the machine body, there are: an inverter arranged to face the electric motor; and a second electrical device electrically connected to the inverter, The second electrical device is above the inverter and configured to face the battery unit.

14. The electric working machine according to claim 1, wherein the exterior part includes a body frame, and the body frame is located at the bottom of the body, the first opening is provided in the body frame.

15. The electric working machine according to any one of claims 1 to 14, wherein the exterior part includes an engine hood member, and the engine hood member is located at a side of the body, the second opening is provided in the engine hood member.

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