Working machinery

Abstract

To provide a work machine that can efficiently take in air through a highly durable ventilation section. [Solution] The work machine 100 is equipped with a bonnet 1, a ventilation section 2, and a fan 31. The bonnet 1 surrounds the machine body 404. .Pass The air section 2 is located in the bonnet 1 and connects the inside and outside of the aircraft body 404. The fan 31 is located inside the aircraft body 404 and takes in outside air through the ventilation section 2. The ventilation section 2 has a circular opening 21 and an inner wall section 22. The inner wall section 22 extends from the outer surface of the bonnet 1 toward the outer edge of the opening 21 and surrounds at least a portion of the outer edge of the opening 21.

Description

Technical Field

[0001] The present invention relates to a working machine.

Background Art

[0002] Conventionally, a working machine that air-cools the inside of an engine room is known. For example, in the electric excavator of Patent Document 1, air is taken into the inside of the machine room (that is, the engine room) through a ventilation hole provided in the side portion of the exterior cover by driving a cooling fan disposed inside the machine room (covered by an exterior cover (so-called bonnet)).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a small working machine, since a fan, a heat exchanger, etc. are arranged in the narrow space inside the engine room, it is necessary to efficiently take in external air from the ventilation hole. In particular, in an electric hydraulic excavator, it is necessary to cool the power electronics device that drives the hydraulic pump with cooling water or the like, and at the same time cool the hydraulic oil discharged from the hydraulic pump. Therefore, efficient intake of air at the ventilation hole is significantly important. On the other hand, in a working machine during operation, there is a risk that an obstacle may contact the bonnet including the ventilation hole. At this time, if the ventilation hole is deformed, the air intake efficiency may decrease.

[0005] In view of the above situation, an object of the present invention is to provide a working machine that can efficiently take in air from a highly durable ventilation part.

Means for Solving the Problems

[0006] To achieve the above objective, a working machine according to one aspect of the present invention comprises a bonnet, a ventilation section, and a fan. The bonnet encloses the machine body. The ventilation section is located in the bonnet and connects the inside and outside of the machine body. The fan is located inside the machine body and takes in outside air through the ventilation section. The ventilation section has a circular opening and an inner wall. The inner wall extends from the outer surface of the bonnet toward the outer edge of the opening and encloses at least a portion of the outer edge of the opening.

[0007] Further features and advantages of the present invention will be further revealed by the embodiments described below. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a work machine that can efficiently take in air from a highly durable ventilation section. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic side view showing an example configuration of a hydraulic excavator according to this embodiment. [Figure 2] A schematic block diagram showing the electrical and hydraulic systems of a hydraulic excavator. [Figure 3] Cross-sectional view showing the internal structure of the engine room of a hydraulic excavator. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a schematic side view showing an example of the configuration of a hydraulic excavator 100 according to this embodiment. Figure 2 is a schematic block diagram showing the configuration of the electrical and hydraulic systems of the hydraulic excavator 100. The hydraulic excavator 100 is an example of a "working machine" of the present invention.

[0011] <1. Hydraulic Excavator 100> The hydraulic excavator 100 comprises a lower traveling body 200, a work implement 300, and an upper rotating body 400. In this embodiment, the upper rotating body 400 (particularly the engine room 404 described later) may be collectively referred to as the "machine body".

[0012] In this disclosure, direction is defined as follows. First, in the upper rotating body 400, the direction from one side of the driver's seat 4011 (described later) where the operator (driver, pilot) is seated to the other is defined as the "forward-backward direction." Of the "forward-backward direction," the direction from the rear side of the driver's seat 4011 to the front side is defined as "forward," and the direction from the front side of the driver's seat 4011 to the rear side is defined as "rear." Therefore, when the upper rotating body 400 is not rotating relative to the lower traveling body 200 (rotation angle 0°), the forward-backward direction of the upper rotating body 400 coincides with the direction in which the lower traveling body 200 moves forward and backward. Also, when viewed from the rear to the front, the direction from one side of the driver's seat 4011 to the other is defined as the "left-right direction." Of the left-right direction, the direction to the left of the driver's seat 4011 is defined as "leftward," and the direction to the right of the driver's seat 4011 is defined as "rightward." Furthermore, the direction from one of the lower traveling body 200 and the upper rotating body 400 to the other is defined as the "up and down direction." Of the up and down directions, the direction from the lower traveling body 200 to the upper rotating body 400 is defined as "upward," and the direction from the upper rotating body 400 to the lower traveling body 200 is defined as "to the right." Therefore, when the hydraulic excavator 100 is positioned on a horizontal plane with the vertical direction as the normal direction, the up and down direction of the hydraulic excavator 100 coincides with the vertical direction. Moreover, upward coincides with the vertically upward direction, and downward coincides with the vertically downward direction. The front-to-back direction, left-to-right direction, and up and down direction are perpendicular to each other. Note that these direction definitions are used merely for explanatory purposes and are not intended to limit the actual positional relationships and directions.

[0013] <1-1. Lower running body 200> The lower travel body 200 comprises a pair of left and right crawlers 201 and a pair of left and right travel motors 202. Each of the travel motors 202 is a hydraulic motor. The left and right travel motors 202 drive the left and right crawlers 201 respectively, allowing the hydraulic excavator 100 to move forward and backward.

[0014] <1-2. Work Machine 300> The work machine 300 comprises a boom 301, an arm 302, and a bucket 303. By independently driving the boom 301, arm 302, and bucket 303, excavation work such as soil and sand can be performed. The boom 301 is rotated by a boom cylinder 304. The base end of the boom cylinder 304 is supported at the front of the upper slewing body 400 and is movable so as to be able to extend and retract. The arm 302 is rotated by an arm cylinder 305. The base end of the arm cylinder 305 is supported at the boom 301 and is movable so as to be able to extend and retract. The bucket 303 is rotated by a bucket cylinder 306. The base end of the bucket cylinder 306 is supported at the arm 302 and is movable so as to be able to extend and retract. The boom cylinder 304, arm cylinder 305, and bucket cylinder 306 are composed of hydraulic cylinders.

[0015] <1-3. Upper rotating body 400> The upper rotating body 400 is located above the lower traveling body 200 and is mounted to rotate relative to the lower traveling body 200 via a rotating bearing (not shown). The upper rotating body 400 houses a control unit 401, a rotating frame 402, a rotating motor 403, an engine room 404, and the like. The upper rotating body 400 rotates via the rotating bearing, driven by the rotating motor 403, which is a hydraulic motor.

[0016] A hydraulic pump 701 (see Figure 2) is located in the upper slewing body 400. The hydraulic pump 701 is driven by an electric motor 621 (see Figure 2) located inside the engine room 404. The hydraulic pump 701 supplies hydraulic fluid (pressurized oil) to hydraulic motors (for example, the left and right travel motors 202 and the slewing motor 403) and hydraulic cylinders (for example, the boom cylinder 304, the arm cylinder 305, and the bucket cylinder 306). The hydraulic motors and hydraulic cylinders driven by the hydraulic fluid supplied from the hydraulic pump 701 are collectively called hydraulic actuators 703 (see Figure 2).

[0017] In the control unit 401, a driver's seat 4011 is arranged. Around the driver's seat 4011, various levers 4012 are arranged. When the operator sits on the driver's seat 4011 and operates the lever 4012, the hydraulic actuator 703 is driven. Thereby, the lower traveling body 200 can travel, the excavation work by the working machine 300 can be performed, and the upper swing body 400 can swing, etc.

[0018] Also, a battery unit 611 is arranged in the upper swing body 400. The battery unit 611 is composed of, for example, a lithium-ion battery unit and stores electric power for driving the electric motor 621. The battery unit 611 may be composed of a plurality of batteries unitized, or may be composed of a single battery cell.

[0019] A lead battery 628 is further provided in the upper swing body 400. The lead battery 628 outputs a DC voltage of a low voltage (for example, 12V). The output from the lead battery 628 is supplied as a control voltage to, for example, a system controller 627 (see FIG. 2), a drive unit of a fan 31 described later, etc.

[0020] Also, a power supply port (not shown) is provided in the upper swing body 400. The above power supply port and a commercial power supply 500 which is an external power source are connected via a power supply cable 501. Thereby, the hydraulic excavator 100 can charge the battery unit 611 and the lead battery 628.

[0021] The hydraulic excavator 100 may have a configuration that combines hydraulic devices such as the hydraulic actuator 703 and an actuator driven by electric power. Examples of the actuator driven by electric power include an electric traveling motor, an electric cylinder, and an electric swing motor.

[0022] <1-4. Configuration of Electrical System and Hydraulic System> The hydraulic excavator 100 is equipped with a plurality of electrical devices 600. The plurality of electrical devices 600 include a refrigerant cooling device 610 that is cooled by heat exchange with a refrigerant, and an air cooling device 620 that is cooled by airflow. In this embodiment, the refrigerant cooling device 610 includes, for example, a battery unit 611. In this embodiment, the refrigerant is water for cooling, but is not limited to this example and may be a liquid other than water, or a cooling gas such as a non-CFC gas. The air cooling device 620 includes, for example, an electric motor 621, a charger 622, an inverter 623, a PDU (power drive unit) 624, a junction box 625, a DC-DC converter 626, a system controller 627, and a lead-acid battery 628.

[0023] The electric motor 621 is driven by power supplied from the battery unit 611 via the junction box 625 and inverter 623. The electric motor 621 is composed of a permanent magnet motor or an induction motor. The electric motor 621 is mounted on the slewing frame 402. Multiple hydraulic pumps 701 are connected to the rotating shaft (output shaft) of the electric motor 621. The multiple hydraulic pumps 701 include variable displacement pumps and fixed displacement pumps. In Figure 2, the hydraulic pump 701 is shown as a single block. However, the hydraulic pump 701 may be multiple or single, and is not limited to the example in Figure 2. The hydraulic pump 701 is connected to a reservoir 705 via a hydraulic hose 704. The reservoir 705 is a working oil tank that contains (stores) hydraulic fluid. When the hydraulic pump 701 is driven by the electric motor 621, the hydraulic fluid in the reservoir 705 is supplied to the hydraulic actuator 703 via the control valve 702. This drives the hydraulic actuator 703. The control valve 702 is a directional control valve that controls the flow direction and flow rate of the hydraulic fluid supplied to the hydraulic actuator 703. Thus, the hydraulic excavator 100 is equipped with a hydraulic pump 701 that is driven by one of the multiple electrical devices 600 (for example, an electric motor 621) to discharge the hydraulic fluid.

[0024] The charger 622, also called a power supply unit, converts the AC voltage supplied from the commercial power supply 500 (see Figure 1) via the power supply cable 501 into a DC voltage. The inverter 623 converts the DC voltage supplied from the battery unit 611 into an AC voltage and supplies it to the electric motor 621. This causes the electric motor 621 to rotate. The supply of AC voltage (current) from the inverter 623 to the electric motor 621 is performed based on a rotation command output from the system controller 627.

[0025] The PDU624 is a battery control unit that controls the input and output of the battery unit 611 by controlling the internal battery relay.

[0026] The junction box 625 includes a charger relay, an inverter relay, a fuse, and the like. The voltage output from the charger 622 is supplied to the battery unit 611 via the junction box 625 and the PDU 624. The voltage output from the battery unit 611 is supplied to the inverter 623 via the PDU 624 and the junction box 625.

[0027] The DC-DC converter 626 steps down the high-voltage (e.g., 300V) DC voltage supplied from the battery unit 611 via the junction box 625 to a low voltage (e.g., 12V). The voltage output from the DC-DC converter 626 is supplied to the system controller 627, the drive unit of the fan 31, and other components, similar to the output from the lead-acid battery 628.

[0028] The system controller 627 consists of an electronic control unit, also known as an ECU (electronic control unit), and performs electrical control of various parts of the hydraulic excavator 100.

[0029] <1-5. Internal configuration of engine room 404> Figure 3 is a cross-sectional view showing the internal structure of the engine room 404 of the hydraulic excavator 100. Figure 3 shows the cross-sectional structure of the engine room 404 virtually cut by a plane perpendicular to the vertical direction, including the dashed line III-III in Figure 1.

[0030] The hydraulic excavator 100 further comprises a bonnet 1, a ventilation section 2, a duct 4, a fan 31, a radiator 32, and an oil cooler 33. The duct 4, fan 31, radiator 32, and oil cooler 33 are housed in the engine room 404, as shown in Figure 3.

[0031] The bonnet 1, along with the footrest 4013 and side walls 4014, 4015 of the control unit 401, the slewing frame 402, etc., is a housing that covers the engine room 404. In other words, the bonnet 1 is the outer wall of the engine room 404.

[0032] The bonnet 1 has an exhaust port 11. The exhaust port 11 is an opening formed on the front and right side of the bonnet 1, connecting the inside and outside of the engine room 404. In this embodiment, a portion of the outside air taken into the engine room 404 from the ventilation section 2 through the duct 4 is discharged to the outside through the exhaust port 11.

[0033] The ventilation section 2 is located on the bonnet 1 and connects the inside and outside of the engine room 404. The rotation of the fan 31 draws outside air into the engine room 404 through the ventilation section 2. The ventilation section 2 is a circular recess located on the bonnet 1, recessed from the outer surface of the bonnet 1 toward the interior of the engine room 404. At least a portion of the bottom surface of this recess (i.e., the ventilation section 2) is configured to allow ventilation. In this embodiment, the ventilation section 2 is located on the right side of the bonnet 1. However, this example does not exclude configurations where the ventilation section 2 is located in a position other than the right side of the bonnet 1.

[0034] In this way, the ventilation section 2 can have a large surface area for taking in outside air, while also improving the strength of the ventilation section 2 itself through the inner circumference portion of the recess that is recessed from the outer surface of the bonnet 1 (the inner wall portion 22 described later). For example, even if a strong force acts on the ventilation section 2 when the bonnet 1 collides with an obstacle, the deformation of the ventilation section 2 is suppressed or prevented, thereby suppressing or preventing the impact on the intake of outside air. Therefore, the hydraulic excavator 100 can efficiently take in air from the highly durable ventilation section 2.

[0035] Duct 4 is a flow path through which outside air taken in by the ventilation section 2 flows. Duct 4 has a frame shape with openings at both ends in the left and right directions and extends in the left and right directions. One end of duct 4 is connected to the ventilation section 2. The other end of duct 4 (for example, the second opening 422 and the fourth opening 432 described later) opens into the engine room 404. The fan 31, radiator 32, and oil cooler 33 are located inside duct 4. More specifically, these are located in the middle of the outside air flow path inside duct 4. In addition, an inverter 623 and the like are installed in the part of duct 4 to the left of the fan 31 (i.e., downstream of the outside air) (for example, the second flow path section 42 described later). Below duct 4, part of the electric motor 621 and the hydraulic pump 701 are located. In addition, as shown in Figure 34, the charger 622 is located behind duct 4 and the hydraulic pump 701.

[0036] The fan 31 is located inside the engine room 404 and takes in outside air through the ventilation section 2. The fan 31 is rotatably supported inside the duct 4 around a rotation axis CA that extends in the left-right direction. The fan 31 in this embodiment is a suction type. Therefore, when the fan 31 is rotated, outside air passing through the ventilation section 2 is drawn into the duct 4 and flows into the engine room 404.

[0037] The radiator 32 is an example of the "first heat exchanger" of the present invention, and is positioned between the vent 2 and the fan 31. It cools the refrigerant by heat exchange with the outside air (air) taken in by the vent 2. The refrigerant to be cooled is for the electrical equipment 600 in the engine room 404. For example, the refrigerant is supplied from the radiator 32 to refrigerant cooling equipment 610 such as the battery unit 611, and cools the refrigerant cooling equipment 610.

[0038] As shown in Figure 3, the radiator 32 is positioned to the right of the fan 31 (i.e., on the side of the ventilation section 2). In other words, the radiator 32 is positioned upstream of the fan 31 in the direction of the airflow drawn in from the ventilation section 2 by the rotation of the fan 31. Furthermore, when viewed from the left and right, the radiator 32 covers one side of the fan 31 (for example, the rear side).

[0039] For example, in this embodiment, upstream of the fan 31 from the outside air, the rear portion of the fan 31 directly faces the radiator 32 in the left-right direction. The front portion of the fan 31 directly faces the vent 2 in the left-right direction. The "rear portion" of the fan 31 is an example of the "first portion (of the fan)" of the present invention. The "front portion" of the fan 31 is an example of the "second portion (of the fan)" of the present invention. In other words, the radiator 32 faces the rear portion of the fan 31 in the left-right direction, while not facing at least a part of the front portion of the fan 31 in the left-right direction. With the arrangement of the radiator 32 as described above, only a portion of the outside air taken in from the vent 2 can be used for heat exchange in the radiator 32.

[0040] The oil cooler 33 is an example of the "second heat exchanger" of the present invention and is connected to the circulating oil passage via the hydraulic pump 701 and the hydraulic actuator 703 (see Figure 2). The oil cooler 33 cools the hydraulic fluid flowing through the aforementioned oil passage by exchanging heat with the outside air (air) taken in at the ventilation section 2.

[0041] As shown in Figure 3, the oil cooler 33 is positioned to the left of the fan 31 (i.e., on the opposite side from the vent 2). In other words, the oil cooler 33 is positioned downstream of the fan 31 in the direction of the airflow from the vent 2. Furthermore, when viewed from the left-right direction, the oil cooler 33 is covered by the other side of the fan 31 (for example, the front side).

[0042] The oil cooler 33 is positioned between the portion of the fan 31 that directly faces the ventilation section 2 (the front portion) and the inlet for outside air in the third flow path section 43 of the duct 4 (the third opening 431, described later). For example, in this embodiment, downstream of the fan 31, the front portion of the fan 31 directly faces the oil cooler 33 in the left-right direction. The rear portion of the fan 31 directly faces the first opening 421 of the second flow path section 42, described later, in the left-right direction. In other words, the oil cooler 33 faces the front portion of the fan 31 in the left-right direction, while not facing at least a portion of the rear portion of the fan 31 in the left-right direction. With the oil cooler 33 positioned as described above, the remaining portion of the outside air taken in from the ventilation section 2 can be used for heat exchange in the oil cooler 33.

[0043] Furthermore, with the arrangement of the radiator 32 and oil cooler 33 relative to the fan 31 as described above, the hydraulic excavator 100 can divide the outside air taken into the engine room 404 by the rotation of a single fan 31 into two airflows.

[0044] One airflow, after hitting the radiator 32, flows through the rear portion of the fan 31 to the second flow path 42 of the duct 4, which will be described later. Therefore, the radiator 32 can cool the refrigerant supplied to the refrigerant cooling equipment 610 through heat exchange with the aforementioned one airflow.

[0045] The other airflow passes through the front portion of the fan 31 and hits the oil cooler 33, and then flows into the third flow path section 43 of the duct 4, which will be described later. Therefore, the oil cooler 33 can cool the working oil circulating through the oil passages via the hydraulic pump 701 and hydraulic actuator 703 (see Figure 2) by heat exchange with the other airflow mentioned above.

[0046] Thus, in this embodiment, the outside air taken in by the ventilation section 2 can cool the radiator 32 and the oil cooler 33 individually and flow through different passages (i.e., the second passage section 42 and the third passage section 43). This suppresses or prevents one of the airflows from passing through the radiator 32 from the outside air taken in from the ventilation section 2 from hitting the oil cooler 33. Therefore, it is possible to suppress or prevent the airflow whose temperature has risen due to heat exchange in the radiator 32 from hitting the oil cooler 33. Furthermore, the other airflow hits the oil cooler 33 without passing through the radiator 32. Therefore, an airflow with a temperature similar to that of the outside air can be directed to the oil cooler 33. Consequently, the oil cooler 33 can cool the working oil more effectively, that is, the temperature of the working oil can be lowered through heat exchange with the airflow as described above. Furthermore, compared to a configuration in which cooling fans are individually placed on the radiator 32 and oil cooler 33, the cooling structure of the radiator 32 and oil cooler 33 can be realized in a more compact layout suitable for a small hydraulic excavator 100.

[0047] <1-6. Configuration of Ventilation Section 2> Next, the structure of the ventilation section 2 will be described. The ventilation section 2 has an opening 21, an inner wall section 22, a plate section 23, and a ventilation member 24.

[0048] The opening 21 is the outer end of the recess (i.e., the ventilation section 2) described above, and opens outwards from the engine room 404. More specifically, the opening 21 is formed on the outer surface of the bonnet 1, and in this embodiment is located on the right side of the bonnet 1. When viewed from the left-right direction, the opening 21 is circular, and in this embodiment is a perfect circle.

[0049] Preferably, the outer diameter of the opening 21 is greater than or equal to the outer diameter of the fan 31. This allows the fan 31 to smoothly draw a large amount of outside air into the engine room 404 through its rotation. However, this example does not exclude configurations in which the outer diameter of the opening 21 is less than the outer diameter of the fan 31.

[0050] Furthermore, the opening 21 preferably overlaps with the fan 31 when viewed from the left or right direction, and more preferably is circular in shape centered on the rotation axis CA of the fan 31. This allows the fan 31 to draw in outside air more smoothly.

[0051] The inner wall portion 22 is the inner wall portion of the recess (ventilation portion 2) described above. The outer end of the inner wall portion 22 (right end in Figure 3) corresponds to the outer end of the recess (ventilation portion 2) described above, as well as the outer edge of the opening 21. The inner end of the inner wall portion 22 (left end in Figure 3) corresponds to the outer edge of the bottom surface of the recess (ventilation portion 2) described above.

[0052] The inner wall portion 22 extends from the outer surface of the bonnet 1 toward the outer edge of the opening 21, enclosing at least a portion of the outer edge of the opening 21. The inner wall portion 22 improves the strength of the ventilation portion 2 itself. Therefore, even if a strong force is applied to the ventilation portion 2, deformation of the ventilation portion 2 can be suppressed or prevented.

[0053] In detail, the inner wall portion 22 extends to the left (into the engine room 404) from the edge of the bonnet 1 along the outer edge of the opening 21. In this embodiment, the inner wall portion 22 is a concentric plate member that extends inward towards the opening 21 as it widens to the left, and is arranged seamlessly around the entire circumference of the outer edge of the opening 21. However, it is not limited to this example, and the inner wall portion 22 may be cylindrical, extending to the left. Also, the inner wall portion 22 may be arranged with one or more cuts in a part of the entire circumference of the outer edge of the opening 21, for example, it may be C-shaped when viewed from the left or right direction.

[0054] Furthermore, the inner end (left end in Figure 3) and outer end (right end in Figure 3) of the inner wall portion 22 are circular in shape. Preferably, at least one end of the inner wall portion 22 in the left-right direction is perfectly circular. More preferably, as shown in Figure 3, both ends of the inner wall portion 22 in the left-right direction are perfectly circular. However, this example does not exclude configurations where both ends of the inner wall portion 22 in the left-right direction are not perfectly circular.

[0055] The plate portion 23 and the ventilation member 24 constitute the bottom surface of the recess (ventilation portion 2) described above.

[0056] In detail, the plate portion 23 is a member that covers a part of the opening 21, extending inward from at least a part of the inner end of the inner wall portion 22 (the inner side of the engine room 404) toward the opening 21. By arranging the plate portion 23, the rigidity of the ventilation portion 2 (especially the inner wall portion 22) can be improved. For example, even if a force is applied to the ventilation portion 2, the inner surface (i.e., the inner wall portion 22) and bottom surface (i.e., the ventilation member 24 and the plate portion 23) of the recess (ventilation portion 2) will be less likely to deform. Therefore, deformation of the ventilation portion 2 can be suppressed or prevented.

[0057] In this embodiment, the plate portion 23 includes a pair of plate pieces 230 that are arranged opposite each other in the vertical direction. Hereinafter, the upper plate piece 230 may be referred to as the "upper plate portion 231" and the lower plate piece 230 as the "lower plate portion 232". In other words, the plate portion 23 includes the upper plate portion 231 and the lower plate portion 232. The upper plate portion 231 extends downward from the upper part of the outer circumference of the inner end of the inner wall portion 22. The lower plate portion 232 extends upward from the lower part of the outer circumference of the inner end of the inner wall portion. The inner edges of each plate piece 230 (upper plate portion 231, lower plate portion 232) are aligned in the vertical direction and extend parallel to each other in the left-right direction.

[0058] However, the examples are not limited to this, and the pair of plate pieces 230 may be arranged opposite each other in the left-right direction. In this case, the inner edges of each plate piece 230 are aligned in the left-right direction and extend parallel to each other in the up-down direction in this embodiment.

[0059] Since the inner edges of each plate piece 230 extend parallel to each other, the rectangular ends of the duct 4 (the first flow path section 41 described later) can be easily connected. In addition, outside air flowing in near the inner edges of the plate pieces 230 can flow smoothly to the inner wall surface of the duct 4.

[0060] Preferably, the maximum vertical width of the upper plate portion 231 is smaller than the maximum vertical width of the lower plate portion 232. This allows the center of the end of the duct 4 on the opening 21 side to be positioned above the center of the opening 21 in a plan view of the ventilation portion 2. In other words, the duct 4 can be positioned higher. Therefore, other components (for example, the hydraulic pump 701) can be positioned below the duct. Thus, the hydraulic excavator 100 can make effective use of the space in the engine room 404 and compactly arrange the components housed in the engine room 404. However, this example does not exclude a configuration in which the maximum vertical width of the upper plate portion 231 is greater than or equal to the maximum vertical width of the lower plate portion 232.

[0061] The ventilation member 24 is breathable and covers the remaining portion of the opening 21. In this embodiment, the ventilation member 24 is positioned in the central part of the bottom surface of the recess (ventilation section 2) in the vertical direction. However, the arrangement of the ventilation member 24 is not limited to this example. Also, in this embodiment, the ventilation member 24 is a mesh member, but is not limited to this example. For example, the ventilation member 24 may be a member having multiple slits, multiple through holes, or a porous body.

[0062] In this embodiment, the plate portion 23 includes two plate pieces 230 (upper plate portion 231, lower plate portion 232). However, the number and arrangement of the plate pieces 230 are not limited to the examples given above. The number of plate pieces 230 may be one or more. Also, the plate pieces 230 only need to be arranged on at least a part of the inner end of the inner wall portion 22. Alternatively, the plate portion 23 may be arranged around the entire circumference of the inner end of the inner wall portion 22. In this case, the ventilation member 24 is arranged inside the annular inner wall portion 22 in a plan view of the ventilation portion 2 described above.

[0063] Furthermore, the examples in this embodiment do not exclude configurations in which the ventilation section 2 does not have at least one of the plate section 23 and the ventilation member 24. In other words, at least one of the plate section 23 and the ventilation member 24 may be omitted.

[0064] <1-7. Duct 4> Next, an example of the configuration of the duct 4 will be described. As shown in Figure 3, the duct 4 of the hydraulic excavator 100 has a first flow path section 41, a second flow path section 42, and a third flow path section 43. In the first flow path section 41, outside air taken in from the ventilation section 2 flows toward the fan 31. One end of the first flow path section 41 is connected to the ventilation section 2 and is connected to the outside of the hydraulic excavator 100 (particularly the engine room 404) through the opening 21. The fan 31 is located at the other end of the first flow path section 41.

[0065] Of the duct 4, the flow path to the left of the fan 31 (opposite the ventilation section 2) is separated by a partition plate 44. This results in two flow paths aligned in the front-to-back direction. The second flow path 42 is the rear of the two flow paths, and airflow passes through the rear part of the fan 31. The third flow path 43 is the front of the two flow paths, and airflow passes through the front part of the fan 31.

[0066] The second flow path section 42 guides relatively low-temperature outside air (airflow) that has undergone heat exchange in the radiator 32 to air-cooled equipment 620 such as the electric motor 621. The second flow path section 42 has a first opening 421 and a second opening 422. The first opening 421 is the upstream end of the outside air in the second flow path section 42 and opens to the right. The first opening 421 connects to the other end of the first flow path section 41 and faces the rear portion of the fan 31 in the left-right direction. The second opening 422 is the downstream end of the outside air in the second flow path section 42. The upper surface of the second flow path section 42 slopes downward as it moves to the left. Therefore, the left portion of the second flow path section 42 curves downward. As a result, the second opening 422 opens downward and faces the electric motor 621 in the vertical direction. This allows the electric motor 621 to be cooled in a compact layout. However, the shape of the second flow channel 42 is not limited to the shape described above.

[0067] In this way, some of the outside air taken in through the opening 21 comes into contact with the radiator 32, which cools the refrigerant such as water. This outside air becomes a relatively cool airflow through heat exchange with the radiator 32, passes through the rear part of the fan 31, and flows into the first opening 421 of the second flow path section 42. In other words, this outside air bypasses the oil cooler 33 (i.e., passes outside the oil cooler 33) and flows into the interior of the second flow path section 42.

[0068] In this embodiment, the front portion of the inverter 623 is positioned on the rear side of the second flow path section 42. This allows the inverter 623 to be efficiently air-cooled by the relatively low-temperature airflow circulating inside the second flow path section 42.

[0069] Furthermore, in this embodiment, the second opening 422 faces the electric motor 621 in the vertical direction. Therefore, the relatively low-temperature airflow circulating inside the second flow path 42 is sent out from the second opening 422 toward the electric motor 621 and directly hits the electric motor 621. This improves the cooling efficiency of the electric motor 621.

[0070] Furthermore, in this embodiment, some air-cooled equipment 620, such as the charger 622, are arranged around the second flow path 42. The second opening 422 opens toward the space where the electrical equipment 600 is arranged, and is connected to that space. Therefore, the relatively low-temperature airflow discharged from the second opening 422 can air-cool not only the electric motor 621 but also other air-cooled equipment 620 (charger 622, the rear part of the inverter 623, PDU 624, junction box 625, DC-DC converter 626, system controller 627, etc.) and refrigerant-cooled equipment 610 such as the battery unit 611. Consequently, the cooling efficiency of the electrical equipment 600 is further improved.

[0071] Furthermore, in this embodiment, the refrigerant cooling equipment 610 (particularly the battery unit 611) is positioned near the second flow path section 42 (particularly the second opening 422). This allows the hydraulic excavator 100 to cool both the refrigerant cooling equipment 610 and the multiple air-cooled equipment 620 while arranging them compactly. Consequently, the hydraulic excavator 100 can efficiently cool the electrical equipment 600 while making effective use of the limited space in the engine room 404.

[0072] The third flow path section 43 guides the relatively high-temperature outside air (airflow) that has undergone heat exchange in the oil cooler 33 to the exhaust port 11 located on the bonnet 1. The third flow path section 43 has a third opening 431 and a fourth opening 432. The third opening 431 is the upstream end of the outside air in the third flow path section 43, and is aligned in the front-to-back direction with the first opening 421 of the second flow path section 42, separated by a partition plate 44, and opens to the right. The third opening 431 is connected to the other end of the first flow path section 41 and faces the front part of the fan 31 in the left-to-right direction. The fourth opening 432 is the downstream end of the outside air in the third flow path section 43. The rear side of the third flow path section 43 (i.e., the partition plate 44) slopes forward as it moves to the left. Therefore, the left side of the third flow path section 43 curves forward. As a result, the fourth opening 432 opens forward. However, the shape of the third flow channel 43 is not limited to the shape described above.

[0073] Furthermore, an oil cooler 33 is positioned in the third flow path section 43. In this embodiment, as shown in Figure 3, at least a portion of the oil cooler 33 is positioned within the third opening 431 (i.e., the upstream end of the third flow path section 43) and covers the third opening 431.

[0074] In this way, some of the remaining outside air taken in through the opening 21 bypasses the radiator 32 (i.e., passes outside the radiator 32), goes from the opening 21 through the front side of the fan 31, and hits the oil cooler 33 that cools the working oil. This outside air becomes a relatively hot airflow due to heat exchange in the oil cooler 33, flows inside the third flow path section 43, and is discharged forward through the fourth opening 432.

[0075] Furthermore, the airflow discharged forward from the fourth opening 432 does not circulate within the engine compartment 404, but is instead discharged to the outside, for example, from the exhaust port 11 located on the front part of the bonnet 1. This suppresses the rise in internal temperature of the engine compartment 404 and prevents or inhibits the relatively high-temperature airflow from hitting the electrical equipment 600.

[0076] However, the oil cooler 33 may be located inside the third flow path section 43, away from the third opening 431, although it is not limited to the examples given above. Alternatively, the oil cooler 33 may cover either the third opening 431 or the fourth opening 432 outside the third flow path section 43, or it may be located outside the third flow path section 43, near either the third opening 431 or the fourth opening 432.

[0077] <2. Remarks> The embodiments of the present invention have been described above. It should be noted that the embodiments described above are illustrative, and various modifications are possible in the combination of each component and each process, and this will be understood by those skilled in the art as being within the scope of the present invention.

[0078] For example, in the embodiments described above, a hydraulic excavator 100, which is a construction machine, was used as an example of the "working machine" of the present invention. However, this example does not exclude configurations in which the present invention can be applied to working machines other than the hydraulic excavator 100. For example, the "working machine" of the present invention may be other construction machines such as a wheel loader, or agricultural machines such as a combine harvester or tractor.

[0079] <3. Summary> The embodiments described so far will be summarized below.

[0080] For example, the work machine 100 disclosed herein is The bonnet 1 surrounding the aircraft 404, A ventilation section 2 is located on the bonnet 1 and connects the inside and outside of the aircraft body 404, A fan 31 is positioned inside the aircraft body 404 and takes in outside air through the ventilation section 2, Equipped with, The ventilation portion 2 is a circular recess located on the bonnet 1, which is recessed from the outer surface of the bonnet 1 toward the interior of the aircraft body 404. At least a portion of the bottom surface of the ventilation section 2 is configured to allow ventilation (first configuration).

[0081] The work machine 100 with the above first configuration is The aforementioned ventilation section 2 is A circular opening 21, An inner wall portion 22 extends from the outer surface of the bonnet 1 toward the outer edge of the opening 21 and surrounds at least a part of the outer edge of the opening 21, This also refers to a configuration having (the second configuration).

[0082] The work machine 100 with the second configuration described above is The ventilation portion 2 further includes a plate portion 23 that covers a part of the opening 21, The plate portion 23 may also be configured to extend inward toward the opening 21 from at least a part of the inner end of the inner wall portion 22 (third configuration).

[0083] Furthermore, the work machine 100 with the second configuration described above is The plate portion 23 includes a pair of opposing plate pieces 230. The inner edges of each plate piece 230 may be configured to extend parallel in either the front-to-back direction or the up-and-down direction (fourth configuration).

[0084] Furthermore, the work machine 100 having the third or fourth configuration described above, The aforementioned plate portion 23 is The upper plate portion 231 extends from the upper part of the outer circumference of the inner end of the inner wall portion 22, The lower plate portion 232, which extends from the lower part of the outer circumference of the inner end of the inner wall portion 22, Includes, The maximum vertical width of the upper plate portion 231 may be smaller than the maximum vertical width of the lower plate portion 232 (fifth configuration).

[0085] Furthermore, the work machine 100 having any of the above configurations 1 to 5 is, The system further comprises a first heat exchanger 32 positioned between the ventilation section 2 and the fan 31. The first portion of the fan 31 faces the first heat exchanger 32 directly, The second portion of the fan 31 may be configured to directly face the ventilation portion 2 (sixth configuration).

[0086] Furthermore, the work machine 100 of the sixth configuration described above is The first heat exchanger 32 may be configured to cool the refrigerant for the electrical equipment 600 inside the machine body 404 with the outside air (seventh configuration).

[0087] Furthermore, the work machine 100 having any of the above configurations 1 to 7 is, A second heat exchanger 33 is located downstream of the fan 31 from the outside air, A flow path section 43 guides the outside air, whose heat has been exchanged in the second heat exchanger 33, to the exhaust port 11 located in the bonnet 1, Furthermore, The second heat exchanger may be configured to be positioned between the portion of the fan that directly faces the ventilation portion and the inlet of the outside air in the flow path (the eighth configuration).

[0088] Furthermore, the work machine 100 of the eighth configuration described above is The second heat exchanger 33 may be configured to cool the working oil with the outside air (the ninth configuration). [Industrial applicability]

[0089] This invention can be used, for example, in work machinery such as construction machinery and agricultural machinery. [Explanation of Symbols]

[0090] 100... Hydraulic excavator (working machine), 200... Lower travel body, 201... Crawler, 202... Travel motor, 230... Plate section, 231... Upper plate section, 232... Lower plate section, 300... Working machine, 301... Boom, 302... Arm, 303... Bucket, 304... Boom cylinder, 305... Arm cylinder, 306... Bucket cylinder, 400... Upper slewing body, 401... Steering Section, 4011... Driver's seat, 4012... Lever, 4013... Step stool, 4014, 4015... Side wall section, 402... Swing frame, 403... Swing motor, 404... Engine room (airframe), 500... Commercial power supply, 501... Power supply cable, 600... Electrical equipment, 610... Refrigerant cooling equipment, 611... Battery unit, 620... Air cooling equipment, 621... Electric motor, 622... Charger, 6 23...Inverter, 624...PDU, 625...Junction box, 626...DC-DC converter, 627...System controller, 628...Lead-acid battery, 701...Hydraulic pump, 702...Control valve, 703...Hydraulic actuator, 704...Hydraulic hose, 705...Reservoir, 1...Bonnet, 11...Exhaust port, 2...Ventilation port, 21...Opening 22...Inner wall section, 23...Plate section, 24...Ventilation member, 31...Fan, 32...Radiator (first heat exchanger), 33...Oil cooler (second heat exchanger), 4...Duct, 41...First flow path section, 42...Second flow path section, 421...First opening, 422...Second opening, 43...Third flow path section (flow path section), 431...Third opening, 432...Fourth opening, 44...Partition plate, CA...Rotating shaft

Claims

1. The bonnet surrounding the aircraft, A ventilation section is located on the bonnet and connects the inside and outside of the aircraft body, A fan is positioned inside the aircraft and takes in outside air through the ventilation section, Equipped with, The aforementioned ventilation section is a circular recess located in the hood, which is recessed from the outer surface of the hood toward the interior of the aircraft body. A working machine in which at least a portion of the bottom surface of the ventilation section is configured to allow ventilation.

2. The aforementioned ventilation section is, A circular opening, An inner wall portion extending from the outer surface of the bonnet toward the outer edge of the opening, and surrounding at least a part of the outer edge of the opening, The work machine according to claim 1, having the following features.

3. The ventilation portion further includes a plate portion that covers a part of the opening, The work machine according to claim 2, wherein the plate portion extends inward from at least a part of the inner end of the inner wall portion toward the opening.

4. The plate portion includes a pair of opposing plate pieces. The working machine according to claim 3, wherein the inner edges of each plate piece extend parallel in either the front-to-back direction or the up-and-down direction.

5. The aforementioned plate portion is The upper plate portion extends from the upper part of the outer circumference of the inner end of the inner wall portion, The lower plate portion, which extends from the lower part of the outer circumference of the inner end of the inner wall portion, Includes, The work machine according to claim 3, wherein the maximum vertical width of the upper plate portion is smaller than the maximum vertical width of the lower plate portion.

6. The system further comprises a first heat exchanger positioned between the ventilation section and the fan, The first part of the fan faces directly opposite the first heat exchanger, The second part of the fan is directly opposite the ventilation section, the working machine according to any one of claims 1 to 5.

7. The working machine according to claim 6, wherein the first heat exchanger cools the refrigerant for electrical equipment inside the machine body with the outside air.

8. A second heat exchanger is positioned downstream of the fan from the outside air, A flow path section that guides the outside air, whose heat has been exchanged in the second heat exchanger, to an exhaust port located on the bonnet, Furthermore, The working machine according to any one of claims 1 to 5, wherein the second heat exchanger is disposed between the portion of the fan that directly faces the vent portion and the inlet of the outside air in the flow path portion.

9. The working machine according to claim 8, wherein the second heat exchanger cools the working oil with the outside air.

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