Work machine

Abstract

To provide a useful work machine.SOLUTION: An electric hydraulic excavator 100 (a work machine) includes a first battery pack 510 and a second battery pack 511 (battery packs), an electric fan 520 (a fan) that exhausts air inside a machine body to the outside, an electric motor 512 (an electric motor) that rotates using electric power from the first battery pack 510 and the second battery pack 511, and an oil cooler 550 (a heat exchanger) that cools hydraulic oil pumped by a hydraulic pump 530 driven by the electric motor 512. The oil cooler 550 is located behind the first battery pack 510 and the second battery pack 511 and in front of the electric fan 520.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a work machine powered by battery power. [Background technology]

[0002] An electric work machine having a battery box that houses a plurality of batteries is known (see Patent Document 1).

[0003] In such an electric work machine, a battery fan disposed above the battery box circulates air from bottom to top within the space housing the multiple batteries, thereby cooling the batteries. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-45701 Summary of the Invention [Problem to be solved by the invention]

[0005] However, electric work machines need to cool not only the battery, but also electrical equipment such as the electric motor and inverter, as well as the hydraulic oil that powers the actuator. Therefore, in addition to a fan for the battery, separate fans must be installed to cool the electrical equipment and hydraulic oil.

[0006] In particular, in small work machines such as ultra-mini excavators, where the space for arranging equipment is limited, there is a problem in that it is difficult to separately arrange fans for cooling the electrical equipment and hydraulic oil, and a battery fan, in addition to the electrical equipment and hydraulic equipment.

[0007] The present invention has been made in consideration of the problems of the conventional technology described above, and an object of the present invention is to provide a work machine that is driven by battery power and that allows for the efficient arrangement of equipment in the space within the engine room while still allowing for the cooling of heat-generating equipment. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the present invention provides a work machine comprising a battery pack, a first ventilation opening provided at the rear end of the body, a fan arranged between the first ventilation opening and the battery pack, a second ventilation opening provided in front of and above the battery pack, and an electric motor that rotates using power from the battery pack.

[0009] Another aspect of the present invention is a work machine including a third ventilation opening provided in front of the battery pack and below the second ventilation opening.

[0010] Another aspect of the present invention is a work machine in which the third ventilation opening is provided below the battery pack.

[0011] Another aspect of the present invention is a work machine in which the fan is disposed above the third ventilation opening.

[0012] Another aspect of the present invention is a work machine in which at least a portion of the fan is disposed above the battery pack.

[0013] Another aspect of the present invention is a work machine that includes a heat exchanger that cools hydraulic oil pressurized by a hydraulic pump driven by the electric motor, the heat exchanger being positioned rearward of the battery pack and forward of the fan, and the fan discharging air from inside the machine body to the outside.

[0014] Another aspect of the present invention is a work machine including a fourth ventilation opening provided in front of the fan and on a side surface of the machine body adjacent to the fan.

[0015] Another aspect of the present invention is a work machine including a hydraulic oil tank that stores the hydraulic oil and is arranged below the heat exchanger.

[0016] Another aspect of the present invention is a work machine including an electric device arranged above the electric motor that is mechanically connected to the hydraulic pump, which is arranged inside a cutout portion on the side of the lower part of the hydraulic oil tank.

[0017] Another aspect of the present invention is a work machine in which a plurality of the battery packs are arranged in rows at intervals from each other in the front-rear direction. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a work machine that is driven by battery power and that allows for the efficient arrangement of equipment in the space within the engine room while still allowing the heat-generating equipment to be cooled. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a left side view of an electric hydraulic excavator according to an embodiment of the present invention. [Figure 2] FIG. 1 is a rear view of an electric hydraulic excavator according to an embodiment of the present invention. [Figure 3] FIG. 1 is a front view of an upper rotating body from which a driver's seat and a lever stand have been removed of an electric hydraulic excavator according to an embodiment of the present invention. [Figure 4] FIG. 1 is a plan view of an upper rotating body of an electric hydraulic excavator according to an embodiment of the present invention. [Figure 5] FIG. 1 is a left side view of an upper rotating body of an electric hydraulic excavator according to an embodiment of the present invention. [Figure 6] 2 is a cross-sectional view taken along line AA of an upper rotating body of the electric hydraulic excavator according to one embodiment of the present invention. FIG. [Figure 7] FIG. 1 is a BB cross-sectional view of an upper rotating body of an electric hydraulic excavator according to an embodiment of the present invention. [Figure 8]FIG. 2 is a CC sectional view of an upper rotating body of the electric hydraulic excavator according to one embodiment of the present invention. [Figure 9] FIG. 2 is a DD cross-sectional view of an upper rotating body of the electric hydraulic excavator according to one embodiment of the present invention. [Figure 10] FIG. 2 is a schematic diagram showing air flowing through the cross section AA of the upper rotating body of the electric hydraulic excavator according to one embodiment of the present invention. [Figure 11] FIG. 3 is a schematic diagram showing air flowing through a DD cross section of an upper rotating body of an electric hydraulic excavator according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] An electric hydraulic excavator 100 will be described below as a representative example of a work machine according to the present invention, with reference to Figure 1. The direction in which the work implement 400 is arranged on the upper rotating body 300 is the front, and the opposite direction is the rear.

[0021] The electric hydraulic excavator 100 is configured with a self-propelled lower running body 200, an upper rotating body 300 rotatably supported on the lower running body 200, and a working device 400 supported in front of the upper rotating body 300 so as to be rotatable up and down.

[0022] The working device 400 is composed of a swing post 410 supported at the tip of the upper rotating body 300 so as to be able to rotate horizontally, a boom 420 supported on the swing post 410 so as to be able to rotate up and down, an arm 430 attached to the tip of the boom 420 so as to be able to rotate up and down, a bucket 450 attached to the tip of the arm 430 so as to be able to rotate, a swing cylinder 460 installed below the upper rotating body 300 and which rotates the swing post 410 horizontally, a boom cylinder 470 installed below the boom 420 and which moves the boom 420, an arm cylinder 480 installed above the boom 420 and which moves the arm 430, and a bucket cylinder 490 installed above the arm 430 and which moves the bucket 450 via a bucket link 440.

[0023] The lower traveling body 200 has a center frame (not shown) and side frames 210 (only one side is shown) that are paired symmetrically with the center frame and extend in the front-to-rear direction, and the side frames 210 have drive wheels 211 (only one side is shown) driven by a travel motor (not shown) attached to one rear end thereof, and a plurality of idler wheels 212 (only one side is shown) arranged toward one front end thereof. Tracks 213 (only one side is shown) are wound around the drive wheels 211 and the idler wheels 212, and an earth removal device 220 is attached to the front of the center frame.

[0024] The upper rotating body 300 rotates by a swing motor (not shown) via a swing bearing (not shown), and an operator's seat 310 is located from the center to the rear of the upper rotating body 300. Below the operator's seat 310 is located an engine room 350 that is covered from above by a hood 340 that rises from the rear end of the floor 320 and extends to a counterweight 330 that forms the rear end of the upper rotating body 300. In front of the floor 320 is located a lever stand 360 on which various operating devices for operating the electric hydraulic excavator 100 are attached, and the lever stand 360 is formed from a swing frame 370 that supports the floor 320 from below and is formed integrally with the counterweight 330 and supports the structure.

[0025] Next, the ventilation openings for taking in outside air into the engine room 350 will be described with reference to FIGS.

[0026] At the center of the rear surface of the hood 340, a first ventilation opening 380 is formed, which is made up of four openings provided symmetrically on the left and right sides, one above the other.

[0027] At the upper center of the front of the hood 340, second ventilation openings 381 are formed, each consisting of an opening bored so as to extend to both ends of the cockpit 310 on the left and right.

[0028] Below the right side of floor 320, the rod end of swing cylinder 460 is pivotally connected to swing post 410, which is pivotally connected to the tip of revolving frame 370 so as to rotate horizontally, and the bottom side of swing cylinder 460 is pivotally connected to the front bottom surface of the inside side of counterweight 330, with the tube of swing cylinder 460 installed so as to overlap the side bottom surface of revolving frame 370. Side cover 390 is attached, covering the bottom and side of the tube of swing cylinder 460 and extending from the front to counterweight 330, forming a duct that communicates with the inside of engine room 350. Below the front end of side cover 390, a third ventilation port 382 is formed, through which the cylinder rod extends.

[0029] A fourth ventilation port 383 is formed on the front left side of the hood 340 and is made up of four openings that are bored vertically and symmetrically from above.

[0030] The first ventilation port 380 is an exhaust port that exhausts air inside the engine room 350 to the outside, and the second ventilation port 381, the third ventilation port 382, ​​and the fourth ventilation port 383 are suction ports that take in outside air into the engine room 350.

[0031] That is, the first ventilation opening 380 and the second ventilation opening 381 can form a longitudinal air flow in the upper interior of the engine room 350, and outside air can be efficiently taken into the engine room 350.

[0032] The first ventilation port 380 and the third ventilation port 382 can form a longitudinal air flow within the duct formed by the side cover 390 and a longitudinal air flow below the engine room 350, thereby allowing outside air to be efficiently taken into the engine room 350.

[0033] Furthermore, the first ventilation opening 380 and the fourth ventilation opening 383 can form a longitudinal air flow on the right side of the engine room 350, allowing outside air to be efficiently taken into the engine room.

[0034] Next, the inside of the engine room 350 and the inside of the duct formed by the side cover 390 communicating with the engine room 350 will be described with reference to FIGS.

[0035] Inside the engine room 350, there are arranged a first battery pack 510 that is supported in a vibration-isolating manner on the bottom surface of the revolving frame 370 so as to face the front inner wall of the hood 340, and a second battery pack 511 that is supported in a vibration-isolating manner on the bottom surface of the revolving frame 370 behind the first battery pack 510 and forward of the center of the engine room 350.

[0036] Here, since the first battery pack 510 and the second battery pack 511 are positioned forward of the center of the engine room 350, the possibility of damage to the battery packs is reduced even if an obstacle collides with the rear end or front end of the upper rotating body 300.

[0037] In addition, the first battery pack 510 and the second battery pack 511 are extended to the vicinity of the left and right side walls of the engine room 350, and the upper ends of the first battery pack 510 and the second battery pack 511 are positioned below the second ventilation opening 281, so that an upper flow path through which air flows can be formed between the ceiling of the engine room 350 and the upper ends of the first battery pack 510 and the second battery pack 511.

[0038] Furthermore, a space is provided between the side of the first battery pack 510 and the side of the second battery pack 511, and this space can form an ascending flow path through which air flows from below to above due to heat generated by the first battery pack 510 and the second battery pack 511, and the upper flow path and the ascending flow path are connected.

[0039] Counterweight 330 has a recess in rear view that fits into a protrusion at the rear end of bonnet 340, and electric fan 520, which is supported in a vibration-isolating manner in the center of the recess of counterweight 330, is positioned so as to face the inner wall at the rear end of bonnet 340.

[0040] The electric fan 520 faces the first ventilation opening 380, and by rotating the fan to expel outside air from the first ventilation opening 380 to the outside of the engine room 350, the air taken in from the second ventilation opening 381, the third ventilation opening 382, ​​and the fourth ventilation opening 383 can be expelled from the first ventilation opening 380.

[0041] Between the counterweight 330 and the second battery pack 511, there are arranged: an electric motor 512 that is supported in a vibration-isolating manner on the bottom surface of the revolving frame 370 so that one end faces the side wall of the engine room 350 and that rotates using power from the first battery pack 510 and the second battery pack 511; a hydraulic pump 530 that is attached to the other end of the electric motor 512 and is driven by the electric motor 512 to pump hydraulic oil to operate each actuator; and a hydraulic oil tank 540 that is disposed next to the hydraulic pump 530 and faces the side wall of the engine room 350 and stores hydraulic oil.

[0042] The hydraulic oil tank 540 has a cutout portion formed by cutting out a portion of the lower part of the side surface adjacent to the hydraulic pump 530 from below, and by placing the hydraulic pump 530 inside the cutout portion, the electric motor 512, hydraulic pump 530, and hydraulic oil tank 540 can be efficiently accommodated within the engine room 350.

[0043] Between the electric fan 520 and the second battery pack 511, there is an oil cooler 550 for cooling the hydraulic oil, which is arranged above the hydraulic oil tank 540, and a junction box 515 that connects the power of the first battery pack 510 and the second battery pack 511 to an inverter 513, a converter 514, and a charging device (not shown), and is supported in a vibration-isolating manner on a base 560 installed on the bottom surface of the upper rotating body 300 so as to straddle the electric motor 512 from above.

[0044] That is, behind the second battery pack 511, hydraulic equipment such as a hydraulic pump 530, a hydraulic oil tank 540, and an oil cooler 550 are arranged on one side of the engine room 350, and electrical equipment such as an electric motor 512 and a junction box 515 are arranged on the other side of the engine room 350.

[0045] Additionally, a fourth ventilation opening 383 is disposed above the side of the engine room 350 facing the hydraulic oil tank 540 and in front of the oil cooler 550. As a result, it is possible to efficiently cool the hydraulic equipment that generates high temperatures and is disposed on one side of the aircraft rearward of the second battery pack 511. It is possible to arrange the hydraulic equipment and electrical equipment in the engine room 350 without impeding cooling efficiency and storage efficiency.

[0046] Between the floor 320 and the tube of the swing cylinder 460, an inverter 513 is positioned in front of the first battery pack 510 and is supported in a vibration-isolating manner by a base 570 installed on the bottom surface of the upper rotating body 300 so as to straddle the tube of the swing cylinder 460 from above, and controls the power supplied to the electric motor 512 from the first battery pack 510 and the second battery pack 511.

[0047] Furthermore, a converter 512 is disposed in front of the inverter 513, between the floor 320 and the tube of the swing cylinder 460, and is supported in a vibration-isolating manner by a base 580 installed on the bottom surface of the upper rotating body 300 so as to straddle the tube of the swing cylinder 460 from above. The converter 512 converts the voltage of the electricity from the first battery pack 510 and the second battery pack 511 to supply power to a controller (not shown) that performs integrated control of the electric hydraulic excavator 100 and a low-voltage battery (not shown) that supplies power to the electric fan 520.

[0048] The duct formed by the floor 320 and the side cover 390 forms a flow path for air to flow along the swing cylinder 460, communicates with the engine room 350, and forms a lower flow path that flows along the bottom surface of the upper rotating body 300. The duct also communicates with the ascending flow path formed between the first battery pack 510 and the second battery pack 511.

[0049] Next, the flow of air flowing into and out of the engine room 350 will be described with reference to Figures 10 and 11. Here, the arrows in the figures schematically represent the direction of air flow.

[0050] The upper flow path leading to the first ventilation opening 380 passes from the second ventilation opening 381, above the first battery pack 510 and the second battery pack 511, further above the junction box 515 and the oil cooler 550, and passes through the cooling fan 520, which is installed so that a portion of it protrudes upward from the upper ends of the first battery pack 510, the second battery pack 511, the junction box 515, and the oil cooler 550.The cooling fan 520 forms an air flow that flows from the front to the rear of the aircraft above the inside of the engine room 350.

[0051] The air flowing from the front to the rear of the aircraft above the engine room 350 is heated by the electrical and hydraulic equipment installed in the engine room 350, and the air rising toward the top of the engine room 350 can be efficiently discharged through the first ventilation opening 381.

[0052] Furthermore, by providing a space between the side of the first battery pack 510 and the side of the second battery pack 511, the air flowing from below to above due to heat generated by the first battery pack 510 and the second battery pack 511 can be merged with the air flowing from the front to the rear of the aircraft above the engine room 350.

[0053] In addition, the duct formed by the floor 320 and the side cover 390, with the third ventilation port as its suction port, creates an air flow in which air flows from front to rear along the swing cylinder 460 by the cooling fan 520, and the air that has cooled the converter 514 and inverter 513 arranged above the swing cylinder flows into the center of the engine room 350, where it is heated by the electrical and hydraulic equipment installed in the engine room 350, generating an updraft, forming an air flow that flows in the front-to-back direction along the bottom of the upper rotating body 300, and rises while cooling the electric motor 512, hydraulic pump 530, and hydraulic oil tank 550, and the heated air is then discharged from the first ventilation port 380.

[0054] The rising air currents generated by heating by the electrical and hydraulic equipment merge with the air flowing from the front to the rear of the aircraft above the engine room 350, and are discharged from the first ventilation opening 380 without the heated air remaining inside the engine room 350.

[0055] Furthermore, because the third ventilation opening 382 is disposed at a position lower than the first ventilation opening 380 and the third ventilation opening 381 is disposed at a position further lower than the cooling fan, the flow velocity of the air flowing from the front to the rear of the upper interior of the engine room 350 is faster than the flow velocity of the air flowing in the fore-and-aft direction on the bottom surface of the upper rotating body 300. As a result, a larger amount of air flowing from below to above can be merged with the flow of air flowing from the front to the rear of the upper interior of the engine room 350, and heated air inside the engine room 350 can be efficiently discharged from the first ventilation opening 380.

[0056] Furthermore, the air flowing in the forward / backward direction along the bottom surface of the upper rotating body 300 can form an air flow that flows below the first battery pack 510 and the second battery pack 511, and since the air flows from bottom to top along the sides of the first battery pack 510 and the sides of the second battery pack 511, the first battery pack 510 and the second battery pack 511 can be cooled more efficiently.

[0057] In addition, the upper flow path from the second ventilation port 381 to the first ventilation port 380 has a fourth ventilation port 383 on the side wall of the engine room 350 on the hydraulic oil tank 540 and oil cooler 550 side, and by generating an air flow from the fourth ventilation port 383 toward the hydraulic oil tank 540 and oil cooler 550, the hydraulic equipment that generates heat from the electrical equipment can be efficiently cooled.

[0058] In the above, as another embodiment, another ventilation opening may be provided near floor 320 in front of engine room 350, in which case first battery pack 510 can be cooled more efficiently from the front.

[0059] As a further modification, air may be taken into the engine room 350 through the first ventilation port 380, and the air may be exhausted from the engine room 350 through the second ventilation port, the third ventilation port, and the fourth ventilation port.

[0060] The various configurations described in the other embodiments, modifications, or embodiments described above can be adopted in appropriate combination.

[0061] Although the above description has been given using a hydraulic excavator as an example of a work machine, the work machine is not limited to a hydraulic excavator and may be other work machines such as a wheel loader or a compact track loader.

[0062] Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these, and the invention can be expanded or modified within the scope that does not deviate from the spirit of the invention. [Industrial Applicability]

[0063] The present invention relates to a work machine and has industrial applicability. [Explanation of symbols]

[0064] 380 First ventilation opening 381 Second ventilation opening 382 Third ventilation opening 510 First battery pack 512 Electric motor 520 Electric fan (fan)

Claims

1. A battery pack; A fan that exhausts the air inside the aircraft to the outside, an electric motor that rotates using the power of the battery pack; a heat exchanger that cools hydraulic oil pumped by the hydraulic pump driven by the electric motor; A work machine comprising: The work machine, wherein the heat exchanger is disposed rearward of the battery pack and forward of the fan.

2. The battery pack and the heat exchanger are arranged in a position where they overlap in a rear view.

2. The work machine according to claim 1.

3. 3. The work machine according to claim 1, further comprising a hydraulic oil tank that stores the hydraulic oil and is disposed below the heat exchanger.

4. 4. The construction machine according to claim 3, further comprising an electric device disposed above the electric motor that is mechanically coupled to the hydraulic pump disposed inside a cutout portion on a side of a lower portion of the hydraulic oil tank.

5. A first ventilation port is provided at the rear end of the aircraft body, The fan is disposed between the first ventilation opening and the battery pack. A work machine according to any one of claims 1 to 3.

6. a second ventilation port provided in front of and above the battery pack; 6. A work machine according to claim 5.

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