Electric construction machine

Abstract

A vehicle body of an electric construction machine equipped with an electric motor (14) and a battery (15) is provided with: a hydraulic device chamber (13) that is disposed on the front side of the vehicle body and houses a hydraulic device including a hydraulic pump (11); an electric device chamber (19) that is disposed on the rear side of the vehicle body and houses the battery (15) and an electric device including the electric motor (14); a partition member (12) serving as a partition between the hydraulic device chamber (13) and the electric device chamber (19); and an exterior cover (25) covering the electric device chamber (19). The exterior cover (25) is provided with an intake port (32) and an exhaust port (34) for circulating cooling air in the electric device chamber (19). The battery (15) is cooled by a water-cooled cooling device and is disposed between the partition member (12) and the intake port (32) in the front-rear direction of the vehicle body.

Description

electric construction machinery

[0001] The present disclosure relates to an electric construction machine such as a hydraulic excavator that is equipped with an electric motor as a power source.

[0002] A hydraulic excavator, a typical example of construction machinery, comprises a self-propelled lower chassis, a rotatable upper rotating chassis mounted on the lower chassis, and a work implement mounted on the front side of the upper rotating chassis. In recent years, as a measure to curb global warming and air pollution, electric hydraulic excavators powered by electric motors have been put into practical use. These electric hydraulic excavators are equipped with electrical and hydraulic equipment.

[0003] The electrical equipment mounted on an electric hydraulic excavator includes an electric motor that drives a hydraulic pump, an inverter that controls the operation of the electric motor, and the like. The hydraulic equipment includes a hydraulic pump that supplies hydraulic oil to a hydraulic actuator. Therefore, an electric hydraulic excavator is equipped with a heat exchanger for cooling the electrical equipment, a heat exchanger for cooling the hydraulic oil supplied to the hydraulic equipment, and a fan for generating cooling air supplied to each heat exchanger, and these multiple heat exchangers are often arranged adjacent to each other. Furthermore, the upper limit of the temperature of the refrigerant required to cool the electrical equipment is generally lower than the upper limit of the temperature of the refrigerant required to cool the hydraulic equipment. Therefore, in order to efficiently cool the electrical equipment, it is necessary to suppress the heat of the high-temperature hydraulic oil from affecting the heat exchanger that cools the electrical equipment.

[0004] In response to this, an electric hydraulic excavator has been proposed in which the cooling efficiency of the electrical equipment is improved by separating a hydraulic equipment room in which hydraulic equipment is located and an electrical equipment room in which electrical equipment is located by a partition member (see Patent Document 1).

[0005] International Publication No. 2021 / 192165

[0006] However, construction machinery may be used for long periods of time in high-temperature environments. In such cases, even if the hydraulic equipment compartment and the electrical equipment compartment are separated by a partition or other member, the ambient temperature in the electrical equipment compartment increases, reducing the temperature difference between the heat exchanger and the cooling air. As a result, the heat exchanger may not be able to sufficiently cool the cooling water supplied to the electrical equipment.

[0007] The present invention has been made in consideration of the above-mentioned problems of the prior art, and an object of the present invention is to provide an electric construction machine that is capable of efficiently cooling electrical equipment.

[0008] The present invention provides an electric construction machine having a vehicle body on which an electric motor is mounted, a hydraulic pump that is driven by the electric motor and supplies hydraulic oil to a hydraulic actuator provided on the vehicle body, and a battery that stores power to be supplied to the electric motor, the electric construction machine further comprising a water-cooled battery cooling device that cools the battery, the vehicle body being provided with a hydraulic equipment compartment located on the front side of the vehicle body in the longitudinal direction and accommodating hydraulic equipment including the hydraulic pump, an electrical equipment compartment located on the rear side of the vehicle body in the longitudinal direction and accommodating electrical equipment including the electric motor and the battery, a partition member that separates the hydraulic equipment compartment from the electrical equipment compartment, and an exterior cover that covers the electrical equipment compartment, the exterior cover having an intake port and an exhaust port that allow outside air to circulate within the electrical equipment compartment as cooling air, and the battery being disposed between the partition member and the intake port in the longitudinal direction of the vehicle body.

[0009] According to the present invention, the influence of heat from the hydraulic equipment chamber can be suppressed and the electric equipment can be cooled efficiently.

[0010] FIG. 4 is a left side view showing an electric hydraulic excavator according to an embodiment of the present invention. FIG. 5 is a plan view showing hydraulic equipment and electrical equipment mounted on an upper rotating body from above with the cab, covers, etc. removed. FIG. 6 is a rear view showing electrical equipment mounted on the upper rotating body from the rear with the cab, covers, etc. removed. FIG. 7 is a rear view showing the upper rotating body from which the cab has been removed from the rear. FIG. 8 is a cross-sectional view of the louver of the air intake port as seen from the direction of arrows V-V in FIG. 4. FIG. 9 is a right side view of the upper rotating body from which the cab has been removed as seen from the direction of arrows VI-VI in FIG. 4. FIG. 10 is a plan view showing the flow of cooling air in an electrical equipment room. FIG. 11 is a configuration diagram showing an electrical equipment cooling device. FIG. 12 is a configuration diagram showing an air conditioning and heating device. FIG. 13 is a configuration diagram showing a battery and an air conditioning and cooling device.

[0011] An embodiment of the present invention will be described in detail below with reference to Fig. 1 to Fig. 10, taking an electric hydraulic excavator as an example. In the embodiment, the traveling direction of the electric hydraulic excavator is defined as the front-rear direction, and the direction perpendicular to this traveling direction is defined as the left-right direction.

[0012] 1, an electric hydraulic excavator 1 includes a self-propelled crawler-type lower traveling body 2 and an upper rotating body 3 rotatably mounted on the lower traveling body 2. The vehicle body of the electric hydraulic excavator 1 is made up of the lower traveling body 2 and the upper rotating body 3. A swing-type working device 4 is provided on the front side of the upper rotating body 3, and this working device 4 is used to perform work such as excavating earth and sand.

[0013] The upper rotating body 3 is rotatably mounted on the lower traveling body 2 and performs a rotating operation on the lower traveling body 2. The upper rotating body 3 includes a rotating frame 5, a counterweight 6, a cab 7, a hydraulic pump 11, an electric motor 14, a battery 15, and an exterior cover 25.

[0014] The revolving frame 5 constitutes the base of the upper revolving body 3. The revolving frame 5 is attached to the lower traveling body 2 via a revolving device, and the working device 4 is attached to the front side of the revolving frame 5.

[0015] As shown in Figures 2 and 7, the swivel frame 5 includes a bottom plate 5A, a left vertical plate 5B, a right vertical plate 5C, a left side frame 5D, and a right side frame 5E. The bottom plate 5A is located in the center in the left-right direction and extends in the front-to-rear direction. The left vertical plate 5B and the right vertical plate 5C are erected on the bottom plate 5A and extend in the front-to-rear direction while facing each other in the left-to-right direction. The left side frame 5D is fixed to the tip of a left overhanging beam that extends leftward from the bottom plate 5A and the left vertical plate 5B and extends in the front-to-rear direction. The right side frame 5E is fixed to the tip of a right overhanging beam that extends rightward from the bottom plate 5A and the right vertical plate 5C and extends in the front-to-rear direction.

[0016] The counterweight 6 is attached to the rear end of the revolving frame 5. The counterweight 6 balances the weight of the work implement 4 disposed in front of the revolving frame 5. The outer periphery of the counterweight 6 is arc-shaped with the center in the left-right direction protruding rearward. This allows the outer periphery of the counterweight 6 to fit within a certain swing radius when the upper revolving body 3 swings.

[0017] The cab 7 is mounted on the left front side of the revolving frame 5. The cab 7 includes a floor member 7A serving as a base and a cab box 7B disposed on the floor member 7A, forming an operator's cab. The front side of the floor member 7A is attached to the revolving frame 5 via, for example, a tilting support member (not shown) and is tiltable in the front-rear direction about a rotation axis extending in the width direction (left-right direction) of the revolving frame 5. The rear side of the floor member 7A is attached to the left front side of the counterweight 6 via an anti-vibration mount (not shown). A driver's seat 7C for the operator is provided within the cab 7. Travel levers and pedals and work operation levers (neither of which are shown) for operating the electric hydraulic excavator 1 are arranged around the driver's seat 7C. The operator can operate the travel levers and pedals and work operation levers to perform travel operations using the undercarriage 2, swing operations using the upper revolving body 3, excavation work using the work implement 4, and the like by operating the travel levers and pedals and work operation levers.

[0018] The control valve 8 is located below the cab 7 and mounted on the front left side of the revolving frame 5. The control valve 8 is connected via hydraulic lines between a hydraulic power source consisting of a hydraulic oil tank 9 and a hydraulic pump 11 and various hydraulic actuators mounted on the electric hydraulic excavator 1. The control valve 8 selectively supplies hydraulic oil (pressurized oil) discharged from the hydraulic pump 11 to the various hydraulic actuators in response to the operation of the travel lever / pedal operating device and the work lever operating device arranged in the cab 7.

[0019] The hydraulic oil tank 9 is mounted on the front right side of the rotating frame 5. The hydraulic oil tank 9 stores hydraulic oil to be supplied to various hydraulic actuators mounted on the electric hydraulic excavator 1. The oil cooler 10 is disposed adjacent to the right side of the hydraulic oil tank 9. The oil cooler 10 cools the hydraulic oil that is returned to the hydraulic oil tank 9 from the various hydraulic actuators via the control valve 8. An oil cooler fan 10A, which is an electric fan, is disposed between the oil cooler 10 and a right front cover 27, which will be described later. The oil cooler 10 cools the hydraulic oil that is returned to the hydraulic oil tank 9 by means of cooling air generated by the oil cooler fan 10A.

[0020] The hydraulic pump 11 is disposed at a position adjacent to the right side frame 5E behind the hydraulic oil tank 9 and the oil cooler 10. The hydraulic pump 11 is driven by the electric motor 14 to pressurize the hydraulic oil stored in the hydraulic oil tank 9 and discharge it as pressurized oil to various hydraulic actuators mounted on the electric hydraulic excavator 1.

[0021] The partition member 12 is disposed in the front-to-rear center of the revolving frame 5. The partition member 12 rises vertically upward from the bottom plate 5A of the revolving frame 5 and extends laterally between the left side frame 5D and the right side frame 5E. The partition member 12 includes a flat left partition plate 12A disposed between the left side frame 5D and the left vertical plate 5B, a flat intermediate partition plate 12B disposed between the left vertical plate 5B and the right vertical plate 5C, and a flat right partition plate 12C disposed between the right vertical plate 5C and the right side frame 5E. The left partition plate 12A and the intermediate partition plate 12B extend from the bottom plate 5A of the revolving frame 5 to the floor member 7A of the cab 7. The right partition plate 12C is disposed behind the hydraulic pump 11 and extends from the bottom plate 5A to the upper surface of a right front cover 27 (described later).

[0022] The hydraulic equipment room 13 is located in front of the partition member 12 and is formed on the revolving frame 5. The hydraulic equipment room 13 is a space surrounded by the revolving frame 5, the partition member 12, the exterior cover 25, etc. The hydraulic equipment room 13 houses hydraulic equipment including a control valve 8, a hydraulic oil tank 9, an oil cooler 10, a hydraulic pump 11, etc.

[0023] The electric motor 14 is located on the right end side of the right partition plate 12C and is disposed on the rear side of the partition member 12. The electric motor 14 constitutes the power source of the electric hydraulic excavator 1, and is operated by power supplied from the battery 15 to drive the hydraulic pump 11.

[0024] The battery 15 is disposed adjacent to the front side of the counterweight 6 and at the rear end of the revolving frame 5. The battery 15 has multiple battery modules (not shown), for example, consisting of lithium-ion batteries, and supplies power to electrical devices such as the electric motor 14. The battery 15 is formed as a rectangular parallelepiped block extending in the left-right direction by accommodating the multiple battery modules within a housing. Specifically, the battery 15 has a top surface 15A, a front surface 15B, a rear surface 15C, a left side surface 15D, and a right side surface 15E, and the front surface 15B, rear surface 15C, left side surface 15D, and right side surface 15E form peripheral wall surfaces surrounding the top surface 15A. The electric hydraulic excavator 1 is equipped with a battery and air conditioning cooling system 46, which will be described later. During operation of the electric hydraulic excavator 1, the battery 15 is cooled by a water-cooled battery cooling system to maintain a temperature range of, for example, 20°C to 40°C.

[0025] The inverter 16 is disposed on the right side of an upper surface 15A of the battery 15. The inverter 16 controls the drive voltage supplied from the battery 15 to the electric motor 14, thereby controlling the operation of the electric motor 14.

[0026] The charger 17 is disposed on the upper surface 15A of the battery 15 adjacent to the left side of the inverter 16. The charger 17 is electrically connected to a power supply inlet 18 disposed on the rear side (rear surface 15C side) of the battery 15. By connecting an external power supply (not shown) to the power supply inlet 18, power from the external power supply is supplied to the charger 17. The charger 17 supplies power from the external power supply to the inverter 16 and charges the battery 15 with any surplus power.

[0027] The electrical equipment compartment 19 is located on the revolving frame 5 behind the partition member 12. The electrical equipment compartment 19 is a space surrounded by the revolving frame 5, the counterweight 6, the partition member 12, the exterior cover 25, etc. The electrical equipment compartment 19 accommodates electrical equipment including the electric motor 14, the inverter 16, the charger 17, etc., as well as the battery 15.

[0028] The radiator 20 is disposed in the electrical equipment compartment 19 adjacent to the right side of the battery 15. The radiator 20 constitutes part of an electrical equipment cooling device 36 (described later) and cools the coolant supplied to electrical equipment such as the inverter 16 and the charger 17. The radiator 20 faces a right side surface 15E of the battery 15 and a right rear door 30 and a right side cover 31 (described later) in the left-right direction. A radiator fan 21, which is an electric fan, is disposed between the right rear door 30, the right side cover 31, and the radiator 20. An exhaust port 34 (described later) is provided in a portion of the right rear door 30 facing the radiator fan 21. Rotation of the radiator fan 21 generates cooling air within the electrical equipment compartment 19. This cooling air passes through the radiator 20 and is discharged to the outside through the exhaust port 34, thereby cooling the coolant supplied to the electrical equipment.

[0029] The condenser 22 is located in front of the radiator 20 and is disposed within the electrical equipment compartment 19. The compressor 23 is located adjacent to the rear side of the left partition plate 12A and is also disposed within the electrical equipment compartment 19. The condenser 22 and the compressor 23 constitute part of the battery and air conditioning cooling system 46. The condenser 22 cools the refrigerant gas compressed by the compressor 23 using cooling air generated within the electrical equipment compartment 19, converting it into liquid refrigerant. The condenser 22 faces the right side cover 31 at a fixed distance in the left-right direction. A condenser fan 22A, which is an electric fan, is disposed between the condenser 22 and the right side cover 31. A second exhaust port 35, described below, is provided in the right side cover 31 at a location facing the condenser fan 22A. Rotation of the condenser fan 22A generates cooling air within the electrical equipment compartment 19. When the cooling air passes through the condenser 22 and is discharged to the outside through the second exhaust port 35, it exchanges heat with the refrigerant gas supplied to the condenser 22.

[0030] 2 , the condenser 22 is disposed between the partition member 12 and the radiator 20 in the front-to-rear direction. In other words, the radiator 20 is disposed behind the revolving frame 5 so that the condenser 22 is sandwiched between the radiator 20 and the partition member 12 in the front-to-rear direction of the upper revolving body 3. As a result, the radiator 20, which cools the cooling water supplied to electrical equipment such as the electric motor 14, inverter 16, and charger 17, is separated as far as possible from the hydraulic equipment room 13, which becomes hot when the electric hydraulic excavator 1 is in operation.

[0031] In this case, it is known that the cooling efficiency of a heat exchanger increases as the temperature difference between the refrigerant and the outside air temperature increases. Generally, the refrigerant gas supplied to the condenser 22 becomes much hotter than the coolant supplied to the radiator 20 due to compression by the compressor 23. By locating the condenser 22 closer to the hydraulic equipment compartment 13 than the radiator 20, the cooling air supplied to the condenser 22 is warmed by the heat from the hydraulic equipment compartment 13. However, the temperature difference between the refrigerant gas supplied to the condenser 22 and the cooling air is sufficiently larger than the temperature difference between the coolant supplied to the radiator 20 and the cooling air, so the refrigerant cooling efficiency of the condenser 22 can be maintained at a good level.

[0032] The second partition member 24 is disposed in the electrical equipment compartment 19, positioned between the radiator 20 and the condenser 22. The second partition member 24 extends in the left-right direction between the right side surface 15E of the battery 15 and the right side cover 31, separating the radiator 20 and the condenser 22. In this manner, the radiator 20 and the condenser 22 are separated by the second partition member 24 extending from the right side surface 15E of the battery 15. This prevents the cooling air that has flowed into the electrical equipment compartment 19 from the air intake 32 from flowing forward (toward the condenser 22) along the right side surface 15E of the battery 15.

[0033] The exterior cover 25 is disposed on the revolving frame 5 and, together with the revolving frame 5, the counterweight 6, the cab 7, the partition member 12, etc., forms the hydraulic equipment compartment 13 and the electrical equipment compartment 19. The hydraulic equipment compartment 13 and the electrical equipment compartment 19 are covered by the exterior cover 25. As shown in FIGS. 1, 4, and 6, the exterior cover 25 is configured to include a left front cover 26, a right front cover 27, a left rear cover 28, a rear cover 29, a right rear door 30, and a right side cover 31.

[0034] The hydraulic equipment chamber 13 is formed as a space surrounded by the cab 7, partition member 12, left front cover 26, right front cover 27, etc. The left front cover 26 is disposed between the left side frame 5D and the cab 7 and extends in the front-to-rear direction. The left front cover 26 covers the control valve 8 and other components disposed in the hydraulic equipment chamber 13 from the left side. The right front cover 27 is disposed on the right side of the cab 7 and rises upward from the front portion of the right side frame 5E. The right front cover 27 covers the hydraulic oil tank 9, oil cooler 10, hydraulic pump 11, etc. from above and on the right side.

[0035] An opening 27A is formed in the right front cover 27 at a location facing the oil cooler fan 10A. When the oil cooler fan 10A of the oil cooler 10 rotates, outside air (cooling air) flows into the hydraulic equipment chamber 13 from an opening (not shown) formed on the lower side of the revolving frame 5, and this cooling air is discharged to the outside through the opening 27A. When this cooling air passes through the oil cooler 10, heat from the hydraulic oil is dissipated into the cooling air, thereby cooling the hydraulic oil returning to the hydraulic oil tank 9.

[0036] The electrical equipment compartment 19 is formed as a space surrounded by the counterweight 6, cab 7, partition member 12, left rear cover 28, rear cover 29, right rear door 30, right side cover 31, etc. The left rear cover 28 is located to the left rear of the cab 7 and rises upward from the rear portion of the left side frame 5D. The left rear cover 28 covers the battery 15 and other components from the left side and above. The rear cover 29 rises upward from the upper surface 6A of the counterweight 6 and extends in the left-right direction along this upper surface 6A. The upper end of the rear cover 29 bends forward, and the rear cover 29 covers the counterweight 6 and the battery 15 from the rear and above.

[0037] A power feed opening 29A is formed in the center of the rear cover 29 in the left-right direction. The power feed opening 29A is formed in a position of the rear cover 29 corresponding to the power feed inlet 18, and is closed by a power feed door 29B in an openable and closable manner. When using an external power source, the power feed door 29B is opened, and a connection cable (not shown) extending from the external power source is connected to the power feed inlet 18 through the power feed opening 29A. An air intake 32, which will be described later, is formed on the left side of the rear cover 29.

[0038] The right rear door 30 is disposed at the right rear of the cab 7 and rises upward from the rear portion of the right side frame 5E. The right rear door 30 covers the battery 15, the radiator 20, etc. and is openable and closable from the rear, right side, and above. An exhaust port 34, which will be described later, is formed in the right rear door 30.

[0039] The right side cover 31 is disposed between the right rear door 30 and the right front cover 27 and rises upward from the middle of the right side frame 5E in the fore-and-aft direction. The right side cover 31 is disposed between the partition member 12 and the second partition member 24 and covers the electric motor 14, the capacitor 22, etc. from the right side and above. A second exhaust port 35, which will be described later, is formed in the right side cover 31.

[0040] The air intake 32 is formed in the rear cover 29. The air intake 32 is located to the left of the power supply opening 29A and is disposed on the lower left side of the rear cover 29. As shown in Figures 3 and 4 , the air intake 32 is formed as a rectangular opening, and as the radiator fan 21 and the condenser fan 22A rotate, cooling air (outside air) flows into the electrical equipment compartment 19 through the air intake 32.

[0041] The battery 15 is disposed between the air intake 32 and the partition member 12, which separates the hydraulic equipment compartment 13 from the electrical equipment compartment 19. In other words, the battery 15 is disposed between the partition member 12 and the air intake 32 in the front-to-rear direction of the upper rotating body 3. This prevents the cooling air flowing into the electrical equipment compartment 19 through the air intake 32 from being exposed to high temperatures generated in the hydraulic equipment compartment 13 formed in front of the partition member 12. Furthermore, during operation of the electric hydraulic excavator 1, the battery 15 is maintained within a predetermined temperature range (e.g., 20°C to 40°C) by the battery and the water-cooled battery cooling device of the air conditioning cooling device 46. Therefore, the cooling air flowing into the electrical equipment compartment 19 through the air intake 32 is cooled by the battery 15 and then supplied to the radiator 20, thereby improving the cooling efficiency of the radiator 20.

[0042] 3, the intake port 32 is positioned below the upper surface 15A of the battery 15. This allows most of the outside air that flows into the electrical equipment compartment 19 from the intake port 32 to be used as cooling air and guided along the rear surface 15C of the battery 15 to the exhaust port 34. Furthermore, if rainwater or the like gets mixed in the cooling air flowing into the electrical equipment compartment 19, it is possible to prevent the moisture from adhering to the inverter 16, charger 17, and the like that are attached to the upper surface 15A of the battery 15.

[0043] As shown in Figure 5, the air intake 32 is provided with a louver 33 as an air guide member. The louver 33 has multiple plates 33A that are inclined diagonally rightward (toward the exhaust port 34) with respect to the front-to-rear direction. As a result, the cooling air that flows into the electrical equipment compartment 19 through the air intake 32 is guided by the louver 33 toward the exhaust port 34.

[0044] The exhaust port 34 is formed in the right rear door 30. The exhaust port 34 is composed of two rectangular openings, one above the other, located in the right rear door 30 at a height corresponding to the height of the radiator fan 21. When the radiator fan 21 rotates, cooling air flows into the electrical equipment compartment 19 through the intake port 32. Most of this cooling air is discharged to the outside through the exhaust port 34, and as this cooling air passes through the radiator 20, the electrical equipment, such as the electric motor 14, the inverter 16, and the charger 17, is cooled by the electrical equipment cooling device 36.

[0045] Here, focusing on the positional relationship between the intake port 32 and the exhaust port 34, as shown by the two-dot chain line in FIG. 7 , the intake port 32 and the exhaust port 34 are arranged in a position sandwiching a portion of the battery 15 in the left-right direction of the upper rotating body 3, specifically, the rear surface 15C and the right side surface 15E of the battery 15. This allows the cooling air flowing into the electrical equipment compartment 19 from the intake port 32 to be guided along the rear surface 15C and the right side surface 15E of the battery 15 to the exhaust port 34. The battery 15 is cooled to a temperature range of, for example, 20°C to 40°C by the battery and air conditioning cooling system 46. Therefore, the cooling air flowing along the rear surface 15C and the right side surface 15E of the battery 15 passes through the radiator 20 while being cooled by the battery 15, and is then discharged to the outside of the electrical equipment compartment 19 through the exhaust port 34. In this way, the temperature of the refrigerant supplied to the radiator 20 can be lowered by using the water-cooled battery 15.

[0046] Moreover, because the exhaust port 34 is formed in the right rear door 30, a large distance can be secured between the exhaust port 34 and the intake port 32 formed in the rear cover 29. As a result, even if the cooling air heated by heat exchange with the radiator 20 is discharged from the exhaust port 34 to the outside of the electrical equipment compartment 19, the heated cooling air can be prevented from flowing back into the electrical equipment compartment 19 through the intake port 32.

[0047] The second exhaust port 35 is formed in the right side cover 31. The second exhaust port 35 is composed of two rectangular openings, one above the other, located on the right side cover 31 at a height corresponding to the height of the condenser fan 22A. When the radiator fan 21 rotates, cooling air flows into the electrical equipment compartment 19 through the air intake 32, and a portion of this cooling air is discharged to the outside through the second exhaust port 35. When this cooling air passes through the condenser 22, the heat of the refrigerant gas supplied to the condenser 22 is dissipated into the cooling air, thereby cooling the battery 15 by the battery and air conditioning cooling device 46.

[0048] As described above, the right rear door 30 has an exhaust port 34 formed at a position corresponding to the radiator fan 21, and the right side cover 31 has a second exhaust port 35 formed at a position corresponding to the condenser fan 22A. As a result, as shown in Fig. 7 , a first cooling air path (arrow F1 in Fig. 7 ) that flows from the intake port 32, passes along the rear surface 15C of the battery 15, passes through the radiator 20, and reaches the exhaust port 34, and a second cooling air path (arrow F2 in Fig. 7 ) that flows from the intake port 32, passes along the front surface 15B of the battery 15, passes through the condenser 22, and reaches the second exhaust port 35 are formed within the electrical equipment compartment 19. The cooling air flowing through the first cooling air path F1 is cooled by the rear surface 15C and right surface 15E of the battery 15, and the cooling air flowing through the second cooling air path F2 is cooled by the left surface 15D and front surface 15B of the battery 15. In this way, the cooling air flowing through the first cooling air path F1 and the cooling air flowing through the second cooling air path F2 flow along different surfaces of the battery 15, thereby efficiently cooling each of them.

[0049] As shown in FIGS. 8 to 10, the electric hydraulic excavator 1 is equipped with an electric equipment cooling device 36, an air conditioning and heating device 41, and a battery and air conditioning and cooling device 46.

[0050] The electric equipment cooling device 36 cools the electric equipment housed in the electric equipment compartment 19, such as the electric motor 14, inverter 16, and charger 17. As shown in FIG. 8 , the electric equipment cooling device 36 has a radiator pipe 37 that circulates cooling water through the radiator 20, and a motor cooling pipe 38 and an inverter cooling pipe 39 that are connected in parallel to the radiator pipe 37. The motor cooling pipe 38 is connected to a water jacket (not shown) of the electric motor 14, and a pump 38A is used to circulate the cooling water. The inverter cooling pipe 39 is connected to water jackets (not shown) of the inverter 16 and charger 17, and a pump 39A is used to circulate the cooling water.

[0051] The coolant whose temperature has increased after cooling the electric motor 14 and the coolant whose temperature has increased after cooling the inverter 16 and the charger 17 is cooled by the radiator 20 and circulates through the radiator line 37. In this way, the electric equipment cooling device 36 maintains the coolant cooled by the radiator 20 at a temperature of, for example, about 60°C. A reserve tank 40 is connected to the radiator line 37, and coolant is exchanged between the radiator line 37 and the reserve tank 40 in accordance with changes in pressure in the radiator line 37 that occur due to changes in the coolant temperature. This allows for the replenishment of insufficient coolant, bleeding of air from the coolant, and the like.

[0052] The air conditioning and heating system 41 performs the heating function of an air conditioner (not shown) in the cab 7. As shown in FIG. 9 , the air conditioning and heating system 41 includes a heater core 42 disposed in the air conditioning unit, an electric heater 43 for heating the coolant, a heating pipe 44 connecting the heater core 42 and the electric heater 43, and a pump 44A for circulating the coolant through the heating pipe 44. The coolant flowing through the heating pipe 44 is heated by the electric heater 43 and supplied to the heater core 42. The heater core 42 exchanges heat with the air in the cab 7, thereby heating the interior of the cab 7. A reserve tank 45 is connected to the heating pipe 44, and the pump 44A exchanges coolant between the heating pipe 44 and the reserve tank 45 in response to temperature changes in the coolant circulating through the heating pipe 44, thereby performing operations such as replenishment of the coolant and bleeding of the coolant.

[0053] As shown in FIG. 10 , the battery and air conditioning cooling system 46 includes a water-cooled cooling (temperature control) system for the battery 15 and a cooling system for the air conditioner in the cab 7. In FIG. 10 , the thick solid lines indicate the flow of coolant, and the thick dashed lines indicate the flow of refrigerant gas. The cooling system for the battery 15 includes a battery line 47 connected to the battery 15 and supplying coolant, a pump 47A, an electric heater 48, and a chiller 49. The pump 47A circulates coolant through the battery line 47. The electric heater 48 is connected to the battery line 47 and heats the coolant. The chiller 49 is connected to the battery line 47 and cools the coolant. The coolant flowing through the battery line 47 is heated by the electric heater 48 or cooled by the chiller 49, thereby cooling the battery 15 at a temperature adjusted to maintain a predetermined temperature range (e.g., 20°C to 40°C).

[0054] The temperature of the battery 15 is constantly detected by a temperature sensor or the like (not shown). The battery and air conditioning cooling system 46 selects either a mode in which the coolant is heated by an electric heater 48 or a mode in which the coolant is cooled by a chiller 49, depending on the temperature of the battery 15 detected by the temperature sensor. A reserve tank 50 is connected to the battery conduit 47, and coolant is exchanged between the battery conduit 47 and the reserve tank 50 depending on changes in the temperature of the coolant circulating through the battery conduit 47, thereby performing operations such as replenishing the coolant and bleeding the air out of the coolant.

[0055] The cooling system of the air conditioner includes a refrigerant gas pipe 51 through which refrigerant gas flows, a condenser 22, a compressor 23, a receiver-drier 52, expansion valves 53 and 54, an evaporator 55, and a chiller 49. The chiller 49 is also used as the cooling system for the battery 15. The refrigerant gas flowing through the refrigerant gas pipe 51 is compressed by the compressor 23 and supplied to the condenser 22. The refrigerant is converted into a low-temperature, high-pressure liquid refrigerant through heat exchange with cooling air generated in the electrical equipment compartment 19 by the condenser fan 22A. The liquid refrigerant cooled by the condenser 22 has moisture removed by the receiver-drier 52 and is then decompressed by the expansion valves 53 and 54 to a state where it can evaporate easily. The liquid refrigerant decompressed by the expansion valve 53 is vaporized by the evaporator 55, and the air in the cab 7 is cooled by the evaporative cooling that occurs at this time.

[0056] The liquid refrigerant decompressed by the other expansion valve 54 is vaporized by an evaporator in chiller 49, which constitutes the cooling device for battery 15. The cooling water circulating in battery pipe 47 is cooled by the vaporization cooling that occurs when the liquid refrigerant is vaporized by the evaporator in chiller 49. In this way, condenser 22 constitutes part of battery and air conditioning cooling device 46, and contributes to the cooling function of the air conditioning device as well as the cooling function of battery 15.

[0057] The electric hydraulic excavator 1 according to this embodiment has the configuration as described above. When performing excavation work or the like using the electric hydraulic excavator 1, the operator sits in the cab 7 and operates the electric motor 14 to drive the hydraulic pump 11. In this state, the operator operates the travel levers and pedals (not shown) inside the cab 7 to travel the electric hydraulic excavator 1 to the work site. In addition, the operator can operate the work operation levers (not shown) to perform excavation work of earth and sand or the like using the work device 4 while rotating the upper rotating body 3.

[0058] During operation of the electric hydraulic excavator 1, the oil cooler fan 10A, the radiator fan 21, and the condenser fan 22A are driven to rotate. When the oil cooler fan 10A rotates, outside air (cooling air) flows into the hydraulic equipment room 13 from an opening (not shown) formed on the lower side of the revolving frame 5. This cooling air passes through the oil cooler 10 and is then discharged to the outside of the hydraulic equipment room 13 through an opening 27A in the right front cover 27. The oil cooler 10 dissipates heat from the return oil (hydraulic oil) returning from the hydraulic actuator to the hydraulic oil tank 9 into the cooling air passing through the oil cooler 10. This allows the hydraulic oil returning to the hydraulic oil tank 9 to be cooled. The hydraulic equipment room 13 is separated from the electric equipment room 19 by the partition member 12. Therefore, even if heat is generated in the hydraulic equipment room 13 during operation of the electric hydraulic excavator 1, the transfer of this heat to the electric equipment room 19 can be suppressed.

[0059] Meanwhile, when the radiator fan 21 and the condenser fan 22A rotate, cooling air flows into the electric equipment compartment 19 through an air intake 32 formed in the rear cover 29. In this case, the battery 15 is disposed between the air intake 32 and the partition member 12 that separates the electric equipment compartment 19 and the hydraulic equipment compartment 13. The air intake 32 is disposed below the upper surface 15A of the battery 15. As a result, as shown in FIG. 7 , a first cooling air path F1 that flows along the rear surface 15C of the battery 15 and a second cooling air path F2 that flows along the front surface 15B of the battery 15 are formed in the electric equipment compartment 19.

[0060] The cooling air flowing through the first cooling air path F1 is guided from the intake port 32 along the rear surface 15C and right side surface 15E of the battery 15 to the radiator 20, passes through the radiator 20, and is then discharged to the outside of the electrical equipment compartment 19 through an exhaust port 34 formed in the right rear door 30. The radiator 20 dissipates heat from the coolant, which has been heated by the electrical equipment cooling device 36 cooling the electrical equipment (electric motor 14, inverter 16, charger 17, etc.), into the cooling air passing through the radiator 20. In this case, the cooling air flowing through the first cooling air path F1 is separated from the partition member 12 by the battery 15, and is therefore not heated by the heat generated by the hydraulic equipment compartment 13. As a result, even if the ambient temperature in the electrical equipment compartment 19 becomes high, for example, when the electric hydraulic excavator 1 operates for a long period of time in a high-temperature environment, the coolant is cooled by the radiator 20 of the electrical equipment cooling device 36. Therefore, the electric devices such as the electric motor 14, the inverter 16, the charger 17, etc. can be properly cooled by the cooling water.

[0061] The cooling air flowing through the second cooling air path F2 is guided from the intake port 32 along the left side surface 15D and front surface 15B of the battery 15 to the condenser 22, passes through the condenser 22, and is then discharged to the outside of the electrical equipment compartment 19 through the second exhaust port 35 formed in the right side cover 31. The condenser 22 dissipates heat from the refrigerant gas supplied to the battery and the chiller 49 of the air conditioning cooling device 46 into the cooling air passing through the condenser 22. In this way, the battery 15 can be cooled so as to maintain a predetermined temperature range (e.g., 20°C to 40°C) that is the appropriate operating temperature.

[0062] Therefore, the cooling air flowing through the first cooling air path F1 is cooled by the battery 15 while being guided to the radiator 20 along the rear surface 15C and right side surface 15E of the battery 15. As a result, the temperature of the cooling air supplied to the radiator 20 can be lowered by utilizing the battery 15, and the cooling efficiency of the electric equipment cooling device 36 for the electric motor 14 and other electric equipment can be further improved.

[0063] As described above, in the electric hydraulic excavator 1 according to this embodiment, even if the space for mounting equipment formed on the upper rotating body 3 is narrow and it is not possible to mount a large heat exchanger, the temperature of the cooling air supplied to the radiator 20 can be lowered by utilizing the water-cooled battery 15. As a result, the cooling efficiency of the radiator 20 can be improved, and electrical equipment such as the electric motor 14, inverter 16, and charger 17 can be appropriately cooled.

[0064] Furthermore, the cooling air flowing through the second cooling air path F2 can be cooled by the battery 15 while being guided to the condenser 22 along the left side surface 15D and front surface 15B of the battery 15. As a result, the temperature of the cooling air supplied to the condenser 22 can be lowered by utilizing the battery 15, and the cooling efficiency of the battery and air conditioning cooling device 46 for the battery 15 can also be improved.

[0065] Moreover, the intake port 32 and the exhaust port 34 are arranged at positions sandwiching the rear surface 15C and the right side surface 15E of the battery 15 in the left-right direction of the upper rotating body 3, so that a large gap can be secured between the intake port 32 and the exhaust port 34. As a result, even if the cooling air heated by heat exchange with the radiator 20 is discharged to the outside of the electrical equipment compartment 19 through the exhaust port 34, the heated cooling air is prevented from flowing back into the electrical equipment compartment 19 through the intake port 32, and the temperature rise of the cooling air flowing into the electrical equipment compartment 19 can be suppressed.

[0066] The radiator 20 is disposed behind the revolving frame 5 so as to sandwich the condenser 22 between itself and the partition member 12 in the front-to-rear direction of the upper revolving body 3. This allows the radiator 20, which cools the cooling water supplied to the electric motor 14 and other electrical equipment, to be separated as far as possible from the hydraulic equipment room 13, which becomes hot when the electric hydraulic excavator 1 is in operation, and the efficiency with which the radiator 20 cools the electrical equipment can be improved.

[0067] Furthermore, the intake port 32 is positioned below the upper surface 15A of the battery 15, and the intake port 32 is provided with a louver 33 having multiple plates 33A inclined toward the exhaust port 34. This prevents the cooling air flowing into the electrical equipment compartment 19 through the intake port 32 from flowing over the upper surface 15A of the battery 15 toward the partition member 12. The louver 33 also restricts the direction of the cooling air flowing into the electrical equipment compartment 19 through the intake port 32, allowing most of the cooling air to be guided along the rear surface 15C of the battery 15 to the exhaust port 34. As a result, by directing most of the cooling air flowing into the electrical equipment compartment 19 along the rear surface 15C and right side surface 15E of the battery 15, the temperature of the cooling air can be lowered, and the cooling efficiency of the electrical equipment by the radiator 20 can be further improved.

[0068] Furthermore, a second partition member 24 extending in the left-right direction between the right side surface 15E of the battery 15 and the right side cover 31 is disposed between the radiator 20 and the condenser 22. This prevents the cooling air that has flowed into the electrical equipment compartment 19 from flowing along the rear surface 15C and right side surface 15E of the battery 15 toward the condenser 22. As a result, a large amount of cooling air cooled by the battery 15 can be supplied to the radiator 20, further improving the efficiency with which the radiator 20 cools the electrical equipment.

[0069] Thus, the electric hydraulic excavator 1 according to this embodiment comprises a vehicle body on which an electric motor 14 is mounted, a hydraulic pump 11 that is driven by the electric motor 14 and supplies hydraulic oil to a hydraulic actuator provided on the vehicle body, and a battery 15 that stores the electricity supplied to the electric motor 14, and a water-cooled battery cooling device that cools the battery 15. The vehicle body is provided with a hydraulic equipment compartment 13 that is arranged on the front side of the vehicle body in the longitudinal direction and accommodates hydraulic equipment including the hydraulic pump 11, an electric equipment compartment 19 that is arranged on the rear side of the vehicle body in the longitudinal direction and accommodates the battery 15 and electric equipment including the electric motor 14, a partition member 12 that separates the hydraulic equipment compartment 13 from the electric equipment compartment 19, and an exterior cover 25 that covers the electric equipment compartment 19. The exterior cover 25 has an intake port 32 and an exhaust port 34 that allow outside air to circulate inside the electric equipment compartment 19 as cooling air, and the battery 15 is arranged between the partition member 12 and the intake port 32 in the longitudinal direction of the vehicle body.

[0070] According to this configuration, the battery 15 can separate the air intake 32 from the partition member 12. This prevents the cooling air that flows into the electric equipment compartment 19 from the air intake 32 from being heated by heat from the hydraulic equipment compartment 13, and also makes it possible to lower the temperature of the cooling air by utilizing the water-cooled battery 15. As a result, even if the ambient temperature in the electric equipment compartment 19 becomes high due to, for example, the electric hydraulic excavator 1 performing work for a long period of time in a high-temperature environment, the electric equipment can be efficiently cooled using the cooling air.

[0071] In this embodiment, the intake port 32 and the exhaust port 34 are disposed in positions in the left-right direction of the vehicle body so as to sandwich a part of the battery 15. With this configuration, the cooling air that flows into the electrical equipment compartment 19 from the intake port 32 is guided along the water-cooled battery 15 to the exhaust port 34, thereby lowering the temperature of the cooling air.

[0072] In this embodiment, the battery cooling device includes a radiator fan 21 provided in the electrical equipment compartment 19 for discharging air from the electrical equipment compartment 19 to the outside through an exhaust port 34, and a radiator 20 provided in the electrical equipment compartment 19 for cooling the coolant supplied to the electrical equipment with cooling air generated by the radiator fan 21, and the battery cooling device has a condenser 22 used to cool the battery 15, the condenser 22 being provided in the electrical equipment compartment 19 and disposed between the partition member 12 and the radiator 20 in the fore-and-aft direction of the vehicle body. With this configuration, the radiator 20 for cooling the coolant supplied to the electrical equipment can be separated as far as possible from the hydraulic equipment compartment 13 which generates heat, thereby improving the efficiency of cooling the electrical equipment by the radiator 20.

[0073] In this embodiment, the air intake 32 is located on the exterior cover 25 (rear cover 29) below the upper surface 15A of the battery 15. This configuration prevents the cooling air flowing into the electrical equipment compartment 19 through the air intake 32 from flowing over the upper surface 15A of the battery 15 toward the partition member 12, and the temperature of the cooling air flowing into the electrical equipment compartment 19 can be lowered by using the battery 15, further improving the efficiency of cooling the electrical equipment by the radiator 20.

[0074] In this embodiment, the air intake 32 provided in the exterior cover 25 is provided with a louver 33 that guides the cooling air that flows into the electrical equipment compartment 19 through the air intake 32 toward the exhaust port 34. With this configuration, the louver 33 regulates the direction of the cooling air that flows into the electrical equipment compartment 19 through the air intake 32, and most of the cooling air can be guided toward the exhaust port 34 along the battery 15.

[0075] In this embodiment, the battery cooling device includes a condenser fan 22A, and the exterior cover 25 has a second exhaust port 35 that discharges cooling air generated by the condenser fan 22A to the outside of the electric equipment compartment 19. Within the electric equipment compartment 19, a first cooling air path is formed that flows from the intake port 32 to the rear of the battery 15, passes through the radiator 20, and to the exhaust port 34, and a second cooling air path is formed that flows from the intake port 32 to the front of the battery 15, passes through the condenser 22, and to the second exhaust port 35. With this configuration, the cooling air that flows into the electric equipment compartment 19 from the intake port 32 can be divided into cooling air that is supplied to the radiator 20 through the first cooling air path and cooling air that is supplied to the condenser 22 through the second cooling air path. As a result, sufficient cooling air can be supplied to the radiator 20 through the first cooling air path, and sufficient cooling air can be supplied to the condenser 22 through the second cooling air path.

[0076] In this embodiment, the battery 15 is formed in a block shape having a top surface 15A and peripheral wall surfaces (front surface 15B, rear surface 15C, left side surface 15D, right side surface 15E) surrounding the periphery of the top surface 15A, and the cooling air that flows into the electrical equipment compartment 19 through the air intake 32 is guided to the air exhaust 34 along the peripheral wall surfaces of the battery 15. With this configuration, the temperature of the cooling air that flows into the electrical equipment compartment 19 can be lowered by the battery 15 while it flows along the peripheral wall surfaces of the battery 15.

[0077] In the embodiment, the battery 15 is illustrated as being formed in a block shape with a top surface 15A and peripheral wall surfaces having a rectangular cross section, which are made up of a front surface 15B, a rear surface 15C, a left side surface 15D, and a right side surface 15E. However, the present invention is not limited to this, and may be configured to use a battery formed in a block shape with a top surface and peripheral wall surfaces having a cross section of a polygon with pentagons or more sides, or a battery formed in a block shape with a top surface and peripheral wall surfaces having an elliptical cross section.

[0078] Furthermore, in the embodiment, an electric hydraulic excavator 1 equipped with a crawler-type undercarriage 2 is exemplified. However, the present invention is not limited to this, and can be widely applied to other electric construction machines, such as an electric hydraulic excavator equipped with a wheel-type undercarriage.

[0079] DESCRIPTION OF SYMBOLS 2 Lower traveling body (vehicle body) 3 Upper rotating body (vehicle body) 11 Hydraulic pump 12 Partition member 13 Hydraulic equipment room 14 Electric motor 15 Battery 15A Upper surface 15B Front surface (peripheral wall surface) 15C Rear surface (peripheral wall surface) 15D Left side surface (peripheral wall surface) 15E Right side surface (peripheral wall surface) 19 Electric equipment room 20 Radiator 21 Radiator fan 22 Condenser 22A Condenser fan 25 Exterior cover 32 Air intake 33 Louver (air guide member) 34 Exhaust outlet 35 Second exhaust outlet 46 Battery and air conditioning cooling device

Claims

1. An electric construction machine comprising: a vehicle body on which an electric motor is mounted; a hydraulic pump driven by the electric motor and supplying hydraulic oil to a hydraulic actuator provided on the vehicle body; and a battery for storing power to be supplied to the electric motor; the electric construction machine further comprising: a water-cooled battery cooling device for cooling the battery; and the vehicle body is provided with: a hydraulic equipment compartment located on the front side of the vehicle body in the longitudinal direction and accommodating hydraulic equipment including the hydraulic pump; an electric equipment compartment located on the rear side of the vehicle body in the longitudinal direction and accommodating electric equipment including the electric motor and the battery; a partition member separating the hydraulic equipment compartment from the electric equipment compartment; and an exterior cover that covers the electric equipment compartment; the exterior cover has an intake port and an exhaust port that allow outside air to circulate within the electric equipment compartment as cooling air; and the battery is disposed between the partition member and the intake port in the longitudinal direction of the vehicle body.

2. An electric construction machine as described in claim 1, characterized in that the intake port and the exhaust port are arranged in positions sandwiching a part of the battery in the left-right direction of the vehicle body.

3. An electric construction machine as described in claim 1, further comprising: a fan provided within the electrical equipment compartment for discharging air within the electrical equipment compartment to the outside through the exhaust port; and a radiator provided within the electrical equipment compartment for cooling the cooling water supplied to the electrical equipment with cooling air generated by the fan; wherein the battery cooling device has a capacitor used to cool the battery, and the capacitor is provided within the electrical equipment compartment and is positioned between the partition member and the radiator in the fore-and-aft direction of the vehicle body.

4. The electric construction machine according to claim 1, wherein the air intake is located on the exterior cover below the upper surface of the battery.

5. An electric construction machine as described in claim 4, characterized in that the air intake provided in the exterior cover is provided with an air guide member that guides the cooling air that flows into the electrical equipment compartment through the air intake toward the exhaust port.

6. The electric construction machine described in claim 3, characterized in that the battery cooling device is equipped with a condenser fan, the exterior cover has a second exhaust port that discharges cooling air generated by the condenser fan to the outside of the electrical equipment compartment, and within the electrical equipment compartment, a first cooling air path is formed that flows from the intake port to the rear of the battery, passing through the radiator and to the exhaust port, and a second cooling air path is formed that flows from the intake port to the front of the battery, passing through the condenser and to the second exhaust port.

7. The electric construction machine described in claim 1, characterized in that the battery is formed in a block shape having an upper surface and a peripheral wall surface surrounding the periphery of the upper surface, and the cooling air that flows into the electrical equipment compartment through the air intake is led to the exhaust port along the peripheral wall surface of the battery.

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