Work machinery

Abstract

To provide a work machine capable of properly cooling an electronic component mounted at an upper part of a post-treatment device.SOLUTION: A work machine has: a building having an internal space; an engine stored in the internal space; a cooling fan stored in the internal space on one side in a width direction of the building from the engine, and generating cooling wind directing toward the other side in the width direction; a post-treatment device stored in the internal space on the other side in the width direction from the engine and treating exhaust gas of the engine; and an electronic component mounted at an upper part of the post-treatment device. The building has: a front wall for partitioning a front face of the inner space; a rear wall partitioning a rear face of the internal space; a side wall arranged on the other side in the width direction from the post-treatment device; and an upper face cover partitioning an upper face of the internal space and formed with an exhausting port for exhausting the cooling wind flowing along the front wall and the side wall from the internal space. The exhausting port is positioned at a rear side of the electronic component, with at least a part thereof positioned under an upper end of the electronic component.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a work machine equipped with an aftertreatment device. [Background technology]

[0002] Conventionally, aftertreatment devices for processing exhaust gas from construction machinery engines include EGR (Exhaust Gas Recirculation) devices that recirculate a portion of the exhaust gas to the intake side, DPF (Diesel Particulate Filter) devices that capture particulate matter in the exhaust gas, and NOx catalysts that break down nitrogen oxides (NOx) into water and nitrogen.

[0003] In recent years, as stricter exhaust gas regulations for engines have been applied, aftertreatment devices are equipped with various electronic components, such as various sensors and controllers. However, when these electronic components are housed inside the high-temperature engine building, sufficient heat dissipation measures are required. As a technology for improving the airflow inside the engine room, a configuration in which cooling air generated by a cooling fan is guided from below to above the aftertreatment device is known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-002582 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when electronic components are attached to the top of the post-treatment device, the configuration of Patent Document 1 makes it difficult to supply cooling air to the electronic components hidden behind the post-treatment device, and therefore the heat dissipation measures for the electronic components are not sufficient.

[0006] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a work machine that can appropriately cool electronic components attached to the upper part of an aftertreatment device. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the present invention provides a work machine comprising: a building having an internal space; an engine housed in the internal space; a cooling fan housed in the internal space on one side of the engine in the width direction of the building and generating cooling air flowing toward the other side in the width direction; an aftertreatment device housed in the internal space on the other side of the engine in the width direction and processing exhaust gas from the engine; and electronic components attached to an upper part of the aftertreatment device, wherein the building has a front wall that defines the front side of the internal space, a rear wall that defines the rear side of the internal space, a side wall located on the other side of the aftertreatment device in the width direction, and a top cover that defines the top surface of the internal space and has an exhaust port formed therein that exhausts cooling air flowing along the front wall and the side wall from the internal space, and the exhaust port is located rearward of the electronic component and at least a portion of which is lower than the upper end of the electronic component. [Effects of the Invention]

[0008] According to the present invention, it is possible to obtain a work machine that can appropriately cool electronic components attached to the upper part of the aftertreatment device. Note that problems, configurations, and effects other than those described above will become apparent from the description of the following embodiments. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a side view of a hydraulic excavator, which is a representative example of a work machine according to the present invention. [Figure 2] FIG. 2 is a plan view showing the inside of the engine building. [Figure 3] FIG. 2 is a left side view showing the inside of the engine building. [Figure 4] FIG. 2 is a perspective view of the engine building with the engine compartment cover in the closed position. [Figure 5] FIG. 2 is a perspective view of the engine building with the engine compartment cover in the open position. [Figure 6] 4A and 4B are diagrams illustrating the positional relationship between the electronic components and the exhaust port in the front-rear and left-right directions. [Figure 7] 10A and 10B are diagrams illustrating the positional relationship between the electronic components and the exhaust port in the up-down and left-right directions. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of a work machine according to the present invention will be described with reference to the drawings. Fig. 1 is a side view of a hydraulic excavator 1, which is a representative example of a work machine according to the present invention. In this specification, front, back, left, and right are based on the viewpoint of an operator who is on board and operating the hydraulic excavator 1, unless otherwise specified.

[0011] The hydraulic excavator 1 includes a lower traveling body 2 and an upper rotating body 3 supported by the lower traveling body 2. The lower traveling body 2 and the upper rotating body 3 are an example of a vehicle body. The lower traveling body 2 includes a pair of left and right crawlers. When rotation of a traveling motor (not shown) is transmitted to the pair of left and right crawlers to rotate, the hydraulic excavator 1 travels. However, the lower traveling body 2 may be a wheeled type instead of a crawler type.

[0012] The upper rotating body 3 is rotatably supported on the lower traveling body 2. The driving force of a swing motor (not shown) is transmitted to the upper rotating body 3, causing it to swing relative to the lower traveling body 2. The upper rotating body 3 mainly comprises a swing frame 5 serving as a base, a front working implement 4 attached to the center of the front end of the swing frame 5 so as to be able to swing up and down, a cab (operator's seat) 7 located on the front left side of the swing frame 5, and a counterweight 6 located at the rear end of the swing frame 5.

[0013] The front working implement 4 includes a boom 4a supported on the upper rotating body 3 so that it can be raised and lowered, an arm 4b supported swingably at the tip of the boom 4a, a bucket 4c supported swingably at the tip of the arm 4b, and hydraulic cylinders 4d, 4e, and 4f that drive the boom 4a, arm 4b, and bucket 4c. The counterweight 6 is used to balance the weight of the front working implement 4, and is a heavy object that has an arc shape when viewed from above.

[0014] The cab 7 has an internal space in which an operator who operates the hydraulic excavator 1 sits. A seat on which the operator sits and an operating device operated by the operator seated in the seat are arranged in the internal space of the cab 7. When the operator sitting in the cab 7 operates the operating device, the lower traveling body 2 travels, the upper rotating body 3 rotates, and the front working implement 4 operates.

[0015] The upper rotating body 3 also supports an engine building 10 (building). The engine building 10 is supported by the rotating frame 5 behind the front working implement 4 and the cab 7 and in front of the counterweight 6. The engine building 10 has an internal space that houses components for operating the hydraulic excavator 1 (for example, an engine 21, a cooling fan 22, an aftertreatment device 23, a hydraulic pump 24, etc.).

[0016] Fig. 2 is a plan view showing the interior of the engine building 10. Fig. 3 is a left side view showing the interior of the engine building 10. Note that the left-right direction is an example of the "width direction of the engine building 10", the left side is an example of "one side in the width direction", and the right side is an example of "the other side in the width direction". However, the left and right may be reversed.

[0017] 1 to 3, the internal space of the engine building 10 is defined by a front wall 11, a rear wall 12, a bottom wall 13, a left side wall 14, a right side wall 15, and a top cover 16. More specifically, the front wall 11 defines the front surface of the internal space, the rear wall 12 defines the rear surface of the internal space, the bottom wall 13 defines the bottom surface of the internal space, the left side wall 14 defines the left surface of the internal space, the right side wall 15 defines the right surface of the internal space, and the top cover 16 defines the top surface of the internal space.

[0018] 2, the internal space of the engine building 10 is separated by a partition wall 17 into an engine room 18 and a pump room 19. The engine room 18 and the pump room 19 are adjacent to each other in the left-right direction, with the partition wall 17 sandwiched between them. More specifically, the pump room 19 is located to the right of the engine room 18. The engine room 18 mainly houses an engine 21, a cooling fan 22, a heat exchanger (not shown), and an aftertreatment device 23. The pump room 19 mainly houses a hydraulic pump 24.

[0019] The engine 21 is disposed to the right of the heat exchanger and cooling fan 22 and to the left of the aftertreatment device 23. The engine 21 generates driving force for operating the hydraulic excavator 1 (more specifically, the cooling fan 22 and the hydraulic pump 24) by mixing and burning fuel and air. In addition, the heat generated by the engine 21 causes the temperature inside the engine compartment 18 to rise.

[0020] The cooling fan 22 is disposed to the right of the heat exchanger and to the left of the engine 21. The cooling fan 22 is rotated by the driving force of the engine 21, thereby generating cooling air flowing to the right inside the engine building 10. More specifically, as shown in FIG. 1 , an air intake 14a is formed in the left side wall 14, penetrating through the thickness thereof. As the cooling fan 22 rotates, air that has entered the engine compartment 18 through the air intake 14a flows to the right as cooling air.

[0021] The heat exchanger is disposed to the left of the cooling fan 22. The heat exchanger includes a radiator that exchanges heat between the cooling water that has cooled the engine 21 and the cooling air generated by the cooling fan 22 and supplies the heat to the engine 21 again. The heat exchanger may also include an intercooler that cools the air compressed by a supercharger (turbocharger), a hydraulic oil cooler that cools the hydraulic oil stored in a hydraulic oil tank, and the like.

[0022] The aftertreatment device 23 is disposed to the right of the engine 21. The aftertreatment device 23 purifies the exhaust gas emitted from the engine 21. The aftertreatment device 23 includes, for example, an EGR (Exhaust Gas Recirculation) device that recirculates part of the exhaust gas to the intake side, a DPF (Diesel particulate filter) that collects particulate matter in the exhaust gas, and a NOx catalyst that decomposes nitrogen oxides (NOx) into water and nitrogen.

[0023] The post-processing device 23 includes electronic components 25. The electronic components 25 are mounted on, for example, a board attached to the post-processing device 23. The electronic components 25 include, for example, a sensor that detects the state of the post-processing device 23, a controller that controls the operation of the post-processing device 23, and the like.

[0024] The electronic component 25 is attached to the upper part of the after-treatment device 23. That is, the electronic component 25 faces the top cover 16 (engine compartment cover 16a, described later) at a predetermined interval in the vertical direction. In other words, the electronic component 25 is disposed between the after-treatment device 23 and the top cover 16 in the vertical direction. The electronic component 25 is attached to the right side of the after-treatment device 23. That is, the electronic component 25 faces the partition wall 17 at a predetermined interval in the horizontal direction. In other words, the electronic component 25 is disposed between the after-treatment device 23 and the partition wall 17 in the horizontal direction.

[0025] The hydraulic pump 24 supplies hydraulic oil stored in a hydraulic oil tank (not shown) to the hydraulic actuators (travel motor, swing motor, hydraulic cylinders 4d, 4e, 4f) by transmitting the driving force of the engine 21. This causes the lower traveling body 2 to travel, the upper swing body 3 to swing, and the front working implement 4 to operate.

[0026] Fig. 4 is a perspective view of the engine building 10 with the engine room cover 16a in the closed position. Fig. 5 is a perspective view of the engine building 10 with the engine room cover 16a in the open position. As shown in Figs. 4 and 5, the top cover 16 includes an engine room cover 16a and a pump room cover 16b.

[0027] The engine compartment cover 16a defines the upper surface of the engine compartment 18. The engine compartment cover 16a according to this embodiment is attached so as to be openable and closable by a hinge (not shown) provided at the rear end. As shown in FIG. 4, when the engine compartment cover 16a is in the closed position, the upper surface of the engine compartment 18 is closed. As shown in FIG. 5, when the engine compartment cover 16a is in the open position, the upper surface of the engine compartment 18 is exposed. Note that the engine compartment cover 16a shown in FIGS. 4 and 5 has a separate cover located directly above the engine 21 and a separate cover located directly above the aftertreatment device 23, but these may also be integrated.

[0028] The pump chamber cover 16b defines the upper surface of the pump chamber 19. That is, the pump chamber cover 16b is disposed adjacent to the right side of the engine chamber cover 16a, which is located immediately above the aftertreatment device 23. Note that the pump chamber cover 16b according to this embodiment is configured to be unable to be opened or closed, but it may be openable or closed like the engine chamber cover 16a.

[0029] The engine compartment cover 16a is made up of a top wall 26 and a peripheral wall 27. The top wall 26 is a portion that defines the upper surface of the engine compartment 18. The peripheral wall 27 protrudes from the outer periphery of the top wall 26 in a direction perpendicular to the top wall 26 and is continuous along the outer periphery of the top wall 26. When the pump compartment cover 16b is in the closed position, the top wall 26 is located above the pump compartment cover 16b, and the peripheral wall 27 protrudes downward from the outer periphery of the top wall 26. In other words, the right portion of the peripheral wall 27 (the portion adjacent to the pump compartment cover 16b) is located above the pump compartment cover 16b. In other words, the right portion of the peripheral wall 27 is exposed to the outside of the hydraulic excavator 1.

[0030] Furthermore, exhaust ports 28 are formed in the peripheral wall 27, penetrating the wall in the thickness direction. The exhaust ports 28 are openings through which cooling air generated by the cooling fan 22 is exhausted from the engine compartment 18. The exhaust ports 28 are formed in the right portion (the portion adjacent to the pump chamber cover 16b) of the peripheral wall 27, which is formed to surround the top wall 26. That is, the exhaust ports 28 are formed on the right side surface of the engine compartment cover 16a, above the pump chamber cover 16b. Note that, although the exhaust ports 28 according to this embodiment are composed of two exhaust ports 28a, 28b adjacent to each other in the front-rear direction, the number of exhaust ports 28 is not limited to this.

[0031] Fig. 6 is a diagram showing the positional relationship between the electronic component 25 and the exhaust ports 28a, 28b in the front-rear and left-right directions. Fig. 7 is a diagram showing the positional relationship between the electronic component 25 and the exhaust ports 28a, 28b in the up-down and left-right directions.

[0032] 6, at least a portion of each of the exhaust ports 28a and 28b is located rearward of the electronic component 25. More specifically, the rear end B1 of the exhaust port 28a is located rearward of the rear end B2 of the electronic component 25. Furthermore, the front end F1 of the exhaust port 28b is located rearward of the front end F2 of the electronic component 25.

[0033] 7, at least a portion of the exhaust ports 28a, 28b is located below the upper end of the electronic component 25. More specifically, the lower ends L1 of the exhaust ports 28a, 28b are located below the upper end U2 of the electronic component 25 and above the lower end L2 of the electronic component 25. The upper ends U1 of the exhaust ports 28a, 28b are located above the upper end U2 of the electronic component 25.

[0034] 6 and 7, the exhaust ports 28a and 28b are located to the right of the electronic component 25. That is, gaps are formed in the left-right direction between the electronic component 25 and the exhaust ports 28a and 28b.

[0035] Next, the flow of cooling air within the engine compartment 18 will be described in detail with reference to Figures 2, 3, 6, and 7. In Figures 2, 3, 6, and 7, the main flow of cooling air is indicated by dashed arrows.

[0036] Note that the members 11-17 that define the engine compartment 18 have openings and gaps other than the exhaust ports 28a and 28b. However, the exhaust ports 28a and 28b have a larger opening area than the other openings and gaps. Therefore, most of the cooling air that enters the engine compartment 18 through the intake port 14a is exhausted from the exhaust ports 28a and 28b. The main flow paths of the cooling air from the cooling fan 22 to the exhaust ports 28a and 28b are as follows:

[0037] First, the cooling airflow generated by the cooling fan 22 hits the left side of the engine 21. Then, the cooling airflow that hits the left side of the engine 21 splits into the front and rear of the engine 21, passes through the space between the front wall 11 and the engine 21, and the space between the rear wall 12 and the engine 21, and flows to the right (i.e., toward the partition wall 17).

[0038] 3, when the inside of the engine compartment 18 is viewed from the left side, the rear end P1 of the cooling fan 22 is located forward of the rear end P2 of the engine 21. The upper end of the cooling fan 22 is located below the upper end of the engine 21. Furthermore, the gap between the front wall 11 and the engine 21 in the front-to-rear direction (more specifically, the area of ​​the space through which the cooling air can pass) is wider than the gap between the rear wall 12 and the engine 21 in the front-to-rear direction.

[0039] As a result, most of the cooling air that hits the left side of the engine 21 flows around to the front of the engine 21 and flows to the right along the front wall 11. The cooling air flowing along the front wall 11 hits the partition wall 17 and changes direction rearward. Furthermore, the cooling air is heated by the heat of the engine 21, generating an updraft. The cooling air flowing rearward along the partition wall 17 is then exhausted from the engine compartment 18 through the exhaust ports 28a and 28b.

[0040] According to the above embodiment, for example, the following advantageous effects are achieved.

[0041] According to the above embodiment, by arranging the exhaust ports 28a, 28b behind the electronic components 25, the cooling air flowing rearward along the partition wall 17 passes around the electronic components 25 before being exhausted from the exhaust ports 28a, 28b. Furthermore, by arranging at least a portion of the exhaust ports 28a, 28b below the upper end of the electronic components 25, the cooling air rising inside the engine compartment 18 can be prevented from passing above the electronic components 25 and being exhausted from the exhaust ports 28a, 28b. As a result, the electronic components 25 attached to the upper part of the aftertreatment device 23 can be appropriately cooled.

[0042] Furthermore, according to the above embodiment, by laying out the front wall 11, the rear wall 12, the engine 21, and the cooling fan 22 as shown in Fig. 3, the flow rate of the cooling air flowing into the space between the front wall 11 and the engine 21 is increased. This cooling air cools the electronic components 25 before being exhausted from the exhaust ports 28a, 28b, and therefore the electronic components 25 can be cooled more appropriately.

[0043] Furthermore, according to the above embodiment, by providing the exhaust ports 28a, 28b on the side surface of the engine compartment cover 16a (i.e., the peripheral wall 27), it is possible to prevent rainwater and the like from entering the engine compartment 18. This makes it possible to prevent the electronic components 25 from becoming wet. Note that the exhaust ports 28a, 28b may be fitted with louvers to prevent the intrusion of rainwater, nets to prevent the intrusion of dust, or the like.

[0044] In the above-described embodiment, the hydraulic excavator 1 equipped with a crawler-type undercarriage 2 has been described as an example of a work machine. However, the present invention is not limited to this, and may be applied to, for example, a hydraulic excavator equipped with a wheel-type undercarriage. In addition, the present invention can be widely applied to other work machines such as wheel loaders, dump trucks, and hydraulic cranes.

[0045] The above-described embodiments are merely illustrative examples of the present invention, and are not intended to limit the scope of the present invention to these embodiments. Those skilled in the art can implement the present invention in various other forms without departing from the spirit of the present invention. [Explanation of symbols]

[0046] 1 Hydraulic excavator (work machine) 2 Undercarriage 3 Upper rotating body 4 Front work equipment 4a Boom 4b Arm 4c Bucket 4d, 4e, 4f hydraulic cylinders 5 Swivel frame 6 Counterweight 7 Cab 10 Engine Building 11 Front wall 12 Back wall 13 Bottom wall 14 Left side wall 14a Air intake 15 Right side wall 16 Top cover 16a Engine compartment cover 16b Pump chamber cover 17 Bulkhead 18 Engine room (internal space) 19 Pump room (internal space) 21 Engine 22 Cooling fan 23 Aftertreatment device 24 Hydraulic pump 25 Electronic Components 26 Ceiling wall 27 Peripheral wall 28, 28a, 28b Exhaust port

Claims

1. a building having an interior space; an engine housed in the interior space; a cooling fan that is housed in the internal space on one side of the building in a width direction relative to the engine and generates cooling airflow toward the other side in the width direction; an aftertreatment device that is accommodated in the internal space on the other side of the engine in the width direction and treats exhaust gas from the engine; and an electronic component attached to an upper portion of the aftertreatment device. The building is: a front wall defining a front surface of the interior space; a rear wall defining a rear surface of the interior space; a side wall disposed on the other side of the post-processing device in the width direction; a top cover that defines an upper surface of the interior space and has an exhaust port formed therein through which cooling air flowing along the front wall and the side wall is exhausted from the interior space, The work machine is characterized in that the exhaust port is located rearward of the electronic component and at least a portion of the exhaust port is located below an upper end of the electronic component.

2. 2. The work machine according to claim 1, a hydraulic pump operated by the driving force of the engine; the side wall is a partition wall that separates the internal space into an engine compartment that houses the engine, the cooling fan, and the aftertreatment device, and a pump compartment that houses the hydraulic pump on the other side of the engine compartment in the width direction, The top cover is an engine compartment cover that defines an upper surface of the engine compartment directly above the aftertreatment device; a pump chamber cover defining an upper surface of the pump chamber; The work machine is characterized in that the exhaust port is formed on a side surface of the engine chamber cover above the pump chamber cover.

3. 3. The work machine according to claim 2, A work machine, wherein a gap between the front wall and the engine in the front-to-rear direction is wider than a gap between the rear wall and the engine in the front-to-rear direction.

4. 4. The work machine according to claim 3, A work machine characterized in that a rear end of the cooling fan is located forward of a rear end of the engine.

5. 4. The work machine according to claim 3, A work machine characterized in that an upper end of the cooling fan is located lower than an upper end of the engine.

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