Construction machinery

Abstract

To make it possible to improve cooling efficiency of each heat exchanger.SOLUTION: A heat exchange device 14 comprises a radiator 16 as a first heat exchanger arranged while facing a cooling fan 13, an oil cooler 19 as a second heat exchanger arranged in parallel with the radiator 16 across a gap (space part 20) so as to sandwich at least a portion of a boss 13A in a planar view while facing the cooling fan 13, and a condenser 21 as a third heat exchanger arranged in series with the radiator 16 and the oil cooler 19 with respect to the cooling fan 13. In addition, a condenser vent hole 26 and a fuel cooler vent hole 27 are formed between the radiator 16 and the oil cooler 19.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD

[0001] The present invention relates to a construction machine such as a hydraulic excavator provided with a heat exchange device composed of a plurality of heat exchangers.

BACKGROUND ART

[0002] In general, a construction machine such as a hydraulic excavator includes a self-propelled vehicle body, a cooling fan that generates cooling air, and a heat exchange device provided on the vehicle body in a state of facing the cooling fan. The heat exchange device includes a frame body provided so as to surround the cooling fan, and a plurality of heat exchangers provided inside the frame body that cool a temperature-elevated fluid with the cooling air generated by the cooling fan.

[0003] Here, the cooling fan is formed as an axial-flow cooling fan that has a plurality of blades extending radially from a central boss and generates cooling air by being rotated around the boss. On the other hand, as the plurality of heat exchangers provided in the heat exchange device, a radiator that cools cooling water for cooling a prime mover such as an engine or an electric motor, and an oil cooler that cools hydraulic oil for operating a working device and the like are known. The radiator and the oil cooler are generally arranged side by side so as to be continuous at a position facing the cooling fan (Patent Document 1). Further, the heat exchange device may be provided with, as other heat exchangers, a condenser that cools a refrigerant for an air conditioner that adjusts the environment in a cab, a fuel cooler that cools fuel to be supplied to an engine, and the like.

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

[0004]

PATENT DOCUMENT 1

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] Incidentally, in axial-flow cooling fans, more airflow is generated at the tip of the blades (radially outward) than near the central boss, and less airflow is generated near the boss, including the base of the blades. Therefore, when multiple heat exchangers are arranged in a row facing the cooling fan, the heat exchangers located near the boss, including the base of the blades, cannot receive enough cooling air, resulting in a problem of low cooling efficiency for those heat exchangers near the boss.

[0006] The present invention has been made in view of the problems of the prior art described above, and the object of the present invention is to provide a construction machine that can improve the cooling efficiency of individual heat exchangers. [Means for solving the problem]

[0007] The present invention relates to a construction machine comprising: a self-propelled vehicle body; a cooling fan provided on the vehicle body and having a plurality of blades extending radially from a central boss, which generates cooling air; and a heat exchange device provided on the vehicle body and cooled by the cooling air generated by the cooling fan, wherein the heat exchange device comprises: a first heat exchanger positioned facing the cooling fan; a second heat exchanger positioned facing the cooling fan and spaced parallel to the first heat exchanger so as to sandwich at least a portion of the boss in a plan view; and a third heat exchanger positioned in series with the first and second heat exchangers with respect to the cooling fan. The system comprises a cover member provided between the first heat exchanger and the second heat exchanger, having ventilation holes formed therein, and a frame that houses the first heat exchanger and the second heat exchanger, wherein the ventilation holes are part of the cover member Between the first heat exchanger and the second heat exchanger Shape accomplished The cover member, the first heat exchanger, and the second heat exchanger are each attached to the frame. It can be done. Furthermore, the present invention relates to a construction machine comprising: a self-propelled vehicle body; a cooling fan provided on the vehicle body and having a plurality of blades extending radially from a central boss, which generates cooling air; and a heat exchange device provided on the vehicle body and cooled by the cooling air generated by the cooling fan, wherein the heat exchange device comprises: a first heat exchanger positioned facing the cooling fan; a second heat exchanger positioned facing the cooling fan and spaced parallel to the first heat exchanger so as to sandwich at least a portion of the boss in a plan view; and the first heat exchanger in relation to the cooling fan. The heat exchanger also includes a third heat exchanger arranged in series with the second heat exchanger, and a cover member provided between the first heat exchanger and the second heat exchanger, the cover member having ventilation holes formed in it, the ventilation holes being formed between the first heat exchanger and the second heat exchanger, the cover member having a closed surface portion extending across the first heat exchanger and the second heat exchanger, and a pair of side portions bending and extending from the widthwise edge of the closed surface portion, and sealing members to fill the gaps between the pair of side portions and the first heat exchanger and the second heat exchanger, respectively. [Effects of the Invention]

[0008] According to the present invention, the cooling efficiency of individual heat exchangers can be improved. [Brief explanation of the drawing]

[0009] [Figure 1] This is a left side view showing a hydraulic excavator according to an embodiment of the present invention. [Figure 2] This is a plan view showing the rear portion of the upper rotating body with the building cover omitted. [Figure 3] This is a left side view showing the cooling fan and heat exchanger in Figure 2. [Figure 4] This is a perspective view showing the cooling fan and heat exchanger from the engine side. [Figure 5] This is a left side view showing the heat exchanger and cooling fan with the condenser and fuel cooler removed. [Figure 6] This is a perspective view showing the cover component. [Modes for carrying out the invention]

[0010] Hereinafter, a crawler-type hydraulic excavator will be used as a representative example of a construction machine according to the embodiment of the present invention and will be described in detail with reference to Figures 1 to 6. In this embodiment, the horizontal direction perpendicular to the front-rear direction of the upper rotating body will be defined as the left-right direction, and the configuration and arrangement of each piece of equipment and component will be described accordingly.

[0011] In Figure 1, the hydraulic excavator 1, as a construction machine, comprises a self-propelled crawler-type lower vehicle 2, an upper slewing body 3 rotatably mounted on the lower vehicle 2, and a work device 4 rotatably mounted on the front of the upper slewing body 3 for performing earth excavation work, etc. The lower vehicle 2 and the upper slewing body 3 constitute the vehicle body.

[0012] The upper rotating body 3 comprises a rotating frame 5 that forms a support structure, a cab 6 provided on the left front side of the rotating frame 5, a counterweight 7 provided at the rear of the rotating frame 5, and an exterior cover 8 provided on the rotating frame 5. The cab 6 is where the operator sits, and inside it are a driver's seat where the operator sits, a control lever for driving, a control lever for work, etc. (none of which are shown).

[0013] Further, the outer cover 8 is provided with a left side cover 8A that covers the left side of a cooling chamber 10 described later. As shown in Figure 2, the left side cover 8A is provided with an inflow port 8B that allows external air to flow toward a heat exchange device 14, which will be described later and is arranged in the cooling chamber 10.

[0014] Further, at the rear side of the upper revolving structure 3, there are provided an engine compartment 9 located between the cab 6 and the counterweight 7 and covered by the outer cover 8, and a cooling chamber 10 (see Figure 2) on the left side of the engine compartment 9. The engine compartment 9 and the cooling chamber 10 are partitioned by a partition plate 11.

[0015] The engine 12 is located inside the engine compartment 9 and provided on the rear side of the revolving frame 5. The engine 12 is provided in a horizontally placed state extending in the left-right direction. An output shaft 12A protrudes from the left side of the engine 12, and a cooling fan 13, which will be described later, is attached to the output shaft 12A. On the other hand, a hydraulic pump (not shown) is provided on the right side of the engine 12. This hydraulic pump is driven by the engine 12 to pressurize hydraulic oil and supply it to various actuators and the like provided on the lower traveling structure 2 and the working device 4.

[0016] Here, the engine 12 can be replaced with a prime mover such as an electric motor or a hybrid engine equipped with an electric motor. In the case of an electric motor, the fuel cooler described later becomes unnecessary.

[0017] The cooling fan 13 is attached to the output shaft 12A of the engine 12. The cooling fan 13 is configured as a suction-type cooling fan that draws in external air as cooling air from the inflow port 8B of the outer cover 8 by being driven by the engine 12. The cooling fan 13 also has a boss 13A located at the center and attached to the output shaft 12A of the engine 12, and a plurality of, for example, four blades 13B (see FIG. 4) extending radially from the boss 13A. The cooling fan 13 is formed as an axial-flow cooling fan that generates cooling air with the four blades 13B by rotating around the boss 13A. The cooling fan 13 may be driven by an electric motor or a hydraulic motor instead of the engine 12. Further, the number of blades is not limited to four.

[0018] Here, the axial-flow cooling fan 13 generates cooling air by the four radially extending blades 13B by rotating around the boss 13A. Accordingly, no cooling air is generated at the position of the central boss 13A, the air volume of the cooling air is small on the proximal end side (radially inner side) of the blades 13B due to the low peripheral speed during rotation, and the air volume of the cooling air is large on the distal end side (radially outer side) of the blades 13B due to the high peripheral speed. That is, the axial-flow cooling fan 13 can generate a larger air volume on the distal end side of the blades 13B than in the vicinity of the central boss 13A.

[0019] Next, the configuration of the heat exchange device 14 according to the present embodiment, which cools engine cooling water, working oil, refrigerant and fuel as fluids with cooling air, will be described. Here, since the heat exchange device 14 is arranged on the left side of the suction-type cooling fan 13, the left side is the upstream side in the flow direction of the cooling air, and the right side is the downstream side in the flow direction of the cooling air.

[0020] The heat exchanger 14 is installed on the upper rotating body 3, which constitutes the vehicle body, adjacent to the cooling fan 13. The heat exchanger 14 cools the fluid whose temperature has risen by being cooled by the cooling air generated by the cooling fan 13. The heat exchanger 14 is installed on the rotating frame 5 facing the cooling fan 13. The heat exchanger 14 also works in cooperation with the partition plate 11 to separate the engine compartment 9 from the cooling compartment 10.

[0021] As shown in Figures 2 to 4, the heat exchanger 14 is composed of a frame 15, a radiator 16, an oil cooler 19, a condenser 21, a fuel cooler 22, and a cover member 23, which will be described later.

[0022] As shown in Figure 2, the frame 15 is located to the left of the cooling fan 13 and mounted on the slewing frame 5. The frame 15 is formed as a rectangular frame that penetrates in the left-right direction, surrounding the cooling fan 13. Furthermore, in a structure where the engine 12 is mounted in a transverse position with the engine extending in the left-right direction, the frame 15 is positioned so that the front-rear direction of the upper slewing body 3 is the width direction. That is, the frame 15 is a rectangular frame formed by a front frame 15A, a rear frame 15B, an upper frame 15C, and a lower frame 15D. The radiator 16, oil cooler 19, and condenser 21 are housed inside the frame 15.

[0023] Furthermore, as shown in Figure 4, the frame 15 has a fan shroud 15E on the right side of the front frame 15A, rear frame 15B, upper frame 15C, and lower frame 15D. The fan shroud 15E surrounds the cooling fan 13 and covers the right side of the frame 15, which is on the engine 12 side. This prevents backflow of cooling air from occurring around the cooling fan 13, and ensures that the cooling air flows efficiently from left to right.

[0024] Next, the configuration of the first row of radiators 16 and oil coolers 19, and the second row of condensers 21 and fuel coolers 22, which are installed in the heat exchanger 14, will be described. Note that if a supercharger is installed on the engine, an intercooler that cools the engine intake air whose temperature has risen due to the supercharger can be used as the first or second row of heat exchangers. Also, the positions of the radiators 16 and oil coolers 19 can be reversed.

[0025] The radiator 16, which serves as the first heat exchanger in the first row, is installed inside the frame 15 facing the cooling fan 13, and cools the engine coolant, which is a fluid whose temperature has risen, with the cooling air generated by the cooling fan 13. The radiator 16 has a long, rectangular shape in the vertical direction and is equipped with pipes through which the engine coolant flows and fins for heat dissipation. The upper part of the radiator 16 is attached to the upper frame 15C of the frame 15, and the lower part is attached to the lower frame 15D.

[0026] The radiator 16 has its upper side as the engine coolant inlet and its lower side as the engine coolant outlet. The upper side of the radiator 16 is connected to the outlet side of the engine 12's water jacket (not shown) via an outlet hose 17, and the lower side is connected to the inlet side of the engine 12's water jacket (not shown) via an inlet hose 18. This allows the radiator 16 to cool the heated engine coolant flowing in from the top while efficiently discharging the engine coolant from the bottom by utilizing the characteristic that coolant flows downwards as its temperature decreases.

[0027] As shown in Figure 5, the radiator 16 is positioned on the rear side inside the frame 15, facing the left side of the cooling fan 13. In this case, the radiator 16 is positioned behind the center O of the boss 13A of the cooling fan 13, while being separated from the oil cooler 19 (described later) in the front-rear direction. As a result, the radiator 16 avoids the base end of the boss 13A and the blades 13B, and a large portion of it faces the tip end of the blades 13B.

[0028] The oil cooler 19, which serves as the second heat exchanger in the first row, is installed inside the frame 15, facing the cooling fan 13. In the plan view shown in Figure 2, the oil cooler 19 is arranged in parallel with the radiator 16, spaced apart so as to sandwich at least a portion of the boss 13A. The oil cooler 19 cools the hydraulic fluid, which has become hotter, with the cooling air generated by the cooling fan 13. The oil cooler 19 has a long, rectangular appearance in the vertical direction and is equipped with a pipeline through which the hydraulic fluid flows and fins for heat dissipation. The upper side of the oil cooler 19 is attached to the upper frame 15C of the frame 15, and the lower side is attached to the lower frame 15D.

[0029] The oil cooler 19 has its upper side as the hydraulic fluid inlet and its lower side as the hydraulic fluid outlet. The upper side of the oil cooler 19 is connected to a pipe that returns hydraulic fluid from the actuator, and the lower side is connected to a pipe (neither shown) that returns hydraulic fluid to the hydraulic fluid tank. As a result, the oil cooler 19 can cool the heated hydraulic fluid flowing in from the top, and efficiently discharge the hydraulic fluid from the bottom by utilizing the characteristic that the fluid flows downwards as its temperature decreases.

[0030] The oil cooler 19 is positioned facing the left side of the cooling fan 13, on the front side inside the frame 15, so as to be in almost the same plane as the radiator 16. In this case, the oil cooler 19 is positioned in front of the center O (see Figure 5) of the boss 13A of the cooling fan 13, while being separated from the radiator 16 in the front-rear direction. As a result, the oil cooler 19 avoids the base end of the boss 13A and the blades 13B, and a large portion of it faces the tip end of the blades 13B.

[0031] Here, the radiator 16, which constitutes the first heat exchanger in the first row, and the oil cooler 19, which constitutes the second heat exchanger, are arranged side by side with a space 20 between them, in a plan view as shown in Figure 2, at a position flanking the boss 13A of the cooling fan 13. In this case, the area of ​​boss 13A flanked by the radiator 16 and the oil cooler 19 may be all or part of it, and it is sufficient that at least the vicinity of the center O is flanked. Therefore, the radiator 16 and the oil cooler 19 are positioned in the area of ​​high airflow on the tip side (radially outward) of the blades 13B, avoiding the area of ​​low airflow near boss 13A. This allows the cooling air from the cooling fan 13 to be directed over a large area of ​​the radiator 16 and the oil cooler 19.

[0032] The condenser 21, which serves as the third heat exchanger in the second row, is located inside the frame 15. The condenser 21 is arranged in series with the radiator 16 and the oil cooler 19 relative to the cooling fan 13. Specifically, the condenser 21 is positioned on the left side, opposite the cooling fan 13, so as to overlap with the radiator 16 and the oil cooler 19 in the direction of the cooling airflow. The condenser 21 releases heat (cools) from the vaporized (temperature rise) refrigerant supplied from the indoor unit (not shown) in the cab 6, returning it to a liquid state, and constitutes the outdoor unit of the air conditioning system. The condenser 21 has a long rectangular shape in the left-right direction and is equipped with piping through which the refrigerant flows and fins for heat dissipation. The front of the condenser 21 is attached to the front frame 15A of the frame 15, and the rear of the condenser 21 is attached to the rear frame 15B.

[0033] The condenser 21 is located on the upper side inside the frame 15, facing the radiator 16 and oil cooler 19 to the left. In this case, the condenser 21 is positioned above the fuel cooler 22, separated from it in the vertical direction.

[0034] The fuel cooler 22, which serves as the fourth heat exchanger in the second row, is located inside the frame 15. Like the condenser 21, the fuel cooler 22 is positioned on the left side, opposite the cooling fan 13, so as to overlap the radiator 16 and the oil cooler 19 in the direction of cooling airflow. The fuel cooler 22 cools the fuel, which has risen in temperature as a fluid, with the cooling air generated by the cooling fan 13. The fuel cooler 22 has a long rectangular shape in the left-right direction and is equipped with a pipeline through which fuel flows and fins for heat dissipation. The fuel cooler 22 is attached to the lower frame 15D via a bracket 22A.

[0035] The cover member 23 is provided on the frame 15. The cover member 23 is provided between the radiator 16 and the oil cooler 19. The cover member 23 covers the space 20 and is attached to the frame 15. The cover member 23 has a closed surface portion 23A which is a vertically elongated rectangular plate that extends between the radiator 16 and the oil cooler 19, a front side portion 23B which is bent and extends from the front end edge in the width direction (front-rear direction) of the closed surface portion 23A toward the cooling fan 13, and a rear side portion 23C which is bent and extends from the rear end edge in the width direction (front-rear direction) of the closed surface portion 23A toward the cooling fan 13. As a result, the cover member 23 is formed with a U-shaped cross-section.

[0036] A sealing member 24 is provided between the front side portion 23B, which is one side portion, and the rear end of the oil cooler 19, to fill the gap between the cover member 23 and the oil cooler 19. A sealing member 25 is provided between the rear side portion 23C, which is the other side portion, and the front end of the radiator 16, to fill the gap between the cover member 23 and the radiator 16. As a result, the sealing members 24 and 25 prevent the cooling air flowing toward the radiator 16 and oil cooler 19 from flowing toward the cooling fan 13 side through the gap between the cover member 23 and the radiator 16 and oil cooler 19, where the flow resistance is small.

[0037] As shown in Figure 6, multiple condenser vents 26 and multiple fuel cooler vents 27 are provided in the cover member 23. The multiple condenser vents 26 are positioned facing the condenser 21, which is the second row of third heat exchangers. Specifically, the multiple condenser vents 26 are located in the area from the middle to the upper part of the closed surface portion 23A.

[0038] The multiple condenser vents 26 are configured with opening areas and spacing such that they produce a resistance similar to the flow resistance when cooling air passes through the radiator 16 and oil cooler 19. In other words, the multiple condenser vents 26 are formed with similar opening areas and similar spacing so as not to differ significantly in area.

[0039] On the other hand, the multiple fuel cooler vents 27 are located at the bottom of the closed surface portion 23A. Similar to the multiple condenser vents 26, the opening area and spacing of the multiple fuel cooler vents 27 are set to produce a resistance similar to the flow resistance when cooling air passes through the radiator 16 and oil cooler 19. Furthermore, the multiple fuel cooler vents 27 are formed with similar opening areas and similar spacing that do not differ significantly in size.

[0040] The hydraulic excavator 1 according to this embodiment has the configuration described above, and its operation will now be explained.

[0041] The operator of the hydraulic excavator 1 boards the cab 6 of the upper rotating body 3 and starts the engine 12 to drive the hydraulic pump. This causes pressurized oil to be discharged from the hydraulic pump, and this pressurized oil is supplied to various actuators via a control valve device (not shown).

[0042] The operator in the cab 6 can move the vehicle forward or backward using the lower travel body 2 by operating a travel control lever (not shown). On the other hand, by operating a work control lever (not shown), the operator can rotate the work device 4 to perform earth excavation work, etc.

[0043] When the hydraulic excavator 1 is in operation, the cooling fan 13 draws in outside air through the inlet 8B of the outer cover 8, and this air is supplied as cooling air to the radiator 16, oil cooler 19, condenser 21, and fuel cooler 22 of the heat exchanger 14, thereby cooling the fluids flowing through each of them.

[0044] Thus, according to this embodiment, the heat exchange device 14 consists of a radiator 16 as a first heat exchanger positioned facing the cooling fan 13, an oil cooler 19 as a second heat exchanger positioned in parallel with the radiator 16, with a gap (space 20) between them, and facing the cooling fan 13, so as to sandwich at least a part of the boss 13A in a plan view, and a condenser 21 as a third heat exchanger positioned in series with the radiator 16 and the oil cooler 19 relative to the cooling fan 13. Furthermore, a vent hole 26 for the condenser and a vent hole 27 for the fuel cooler are formed between the radiator 16 and the oil cooler 19.

[0045] Therefore, the radiator 16 and oil cooler 19 can be positioned to avoid the area near boss 13A where the airflow from the cooling fan 13 is low, and instead be placed in the area with a high airflow on the tip side (radially outward) of the blades 13B. This allows a large amount of cooling air to be directed onto the entire surface of both the radiator 16 and the oil cooler 19. As a result, the cooling efficiency of the radiator 16 and oil cooler 19 can be improved.

[0046] In this configuration, if the radiator 16 and the oil cooler 19 are positioned side-by-side with a space 20 in between the boss 13A of the cooling fan 13, the cooling air will flow through the space 20, which has low flow resistance, reducing the amount of cooling air that flows towards the radiator 16 and the oil cooler 19. However, in this embodiment, a condenser vent 26 and a fuel cooler vent 27 are formed between the radiator 16 and the oil cooler 19, so the amount of air passing through the space 20 can be limited by the condenser vent 26 and the fuel cooler vent 27. As a result, more cooling air can be directed to the entire surface of the radiator 16 and the oil cooler 19, thereby improving the cooling efficiency of the radiator 16 and the oil cooler 19.

[0047] Furthermore, by ensuring that cooling air hits the entire surface of the radiator 16 and the entire surface of the oil cooler 19, it is possible to prevent the cooling air from concentrating around the space 20 where it can easily flow. This allows cooling air to be evenly distributed to the entire surface of the second row of condensers 21 and the entire surface of the fuel cooler 22, thereby improving the cooling efficiency of the condensers 21 and the fuel cooler 22.

[0048] Furthermore, the condenser vents 26 consist of multiple holes positioned facing the condenser 21, and the fuel cooler vents 27 consist of multiple holes positioned facing the fuel cooler 22. As a result, cooling air can circulate through the condenser vents 26 and the fuel cooler vents 27, allowing cooling air to be directed at the entire surface of the stacked condenser 21 and the entire surface of the fuel cooler 22.

[0049] Furthermore, the multiple condenser vents 26 of the cover member 23 are positioned facing the condenser 21, and the multiple fuel cooler vents 27 are positioned facing the fuel cooler 22. As a result, the cover member 23 only needs to have condenser vents 26 and fuel cooler vents 27 formed in the necessary positions, thus reducing manufacturing costs.

[0050] The heat exchanger 14 is provided between the radiator 16 and the oil cooler 19 and includes a cover member 23 with condenser vents 26 and fuel cooler vents 27, and a frame 15 that houses the radiator 16 and the oil cooler 19. The cover member 23, the radiator 16, and the oil cooler 19 are each attached to the frame 15. As a result, the heat exchanger 14 can be easily assembled as a single structure using the frame 15.

[0051] The radiator 16 and oil cooler 19 are the radiator 16 for cooling the engine's coolant and the oil cooler 19 for cooling the hydraulic oil. Here, since the radiator 16 and oil cooler 19 generate a relatively large amount of heat, their surface area is also relatively large in order to obtain the necessary cooling performance. In this structure, where the large-area radiator 16 and oil cooler 19 are arranged side by side with the cover member 23, the inside of the frame 15 can be covered, and a smooth flow of cooling air can be created inside the frame 15. In addition, with the large-area radiator 16 and oil cooler 19, it is possible to prevent the cover member 23 from having a complex shape or requiring a large number of cover members 23 in order to cover one side.

[0052] On the other hand, the heat exchanger 14 is provided between the radiator 16 and the oil cooler 19 and has a cover member 23 in which condenser vents 26 and fuel cooler vents 27 are formed. The cover member 23 has a closed surface portion 23A that extends between the radiator 16 and the oil cooler 19, and a front side portion 23B and a rear side portion 23C that bend and extend from the widthwise edge of the closed surface portion 23A. Furthermore, a sealing member 24 is provided between the front side portion 23B and the oil cooler 19 to fill the gap, and a sealing member 25 is provided between the rear side portion 23C and the radiator 16 to fill the gap. As a result, the sealing members 24 and 25 prevent the cooling air flowing toward the radiator 16 and the oil cooler 19 from flowing toward the cooling fan 13 side through the gap between the cover member 23 and the radiator 16 and the oil cooler 19, which has low flow resistance, thus preventing a decrease in cooling efficiency.

[0053] In the embodiment, the case in which the condenser ventilation holes 26 and the fuel cooler ventilation holes 27 are directly provided in the closed surface portion 23A of the cover member 23 was described as an example. However, the present invention is not limited to this, and for example, a large opening may be formed in the closed surface portion, and a punching plate may be fixed to cover this opening to provide ventilation holes in the closed surface portion.

[0054] Furthermore, in the embodiment, a cover member 23 is provided between the radiator 16 and the oil cooler 19, and a condenser vent 26 and a fuel cooler vent 27 are formed in the cover member 23. However, the present invention is not limited to this, and for example, an extension portion extending from the end of the radiator to the oil cooler side may be provided, or an extension portion extending from the end of the oil cooler to the radiator side may be provided, or extension portions may be provided so that the end of the radiator and the end of the oil cooler are close to each other. And the aforementioned extension portions may be configured to have vents.

[0055] Furthermore, in this embodiment, a condenser 21 is exemplified as the third heat exchanger. However, the present invention is not limited to this, and for example, a fuel cooler, an intercooler, or the like may be used as the third heat exchanger.

[0056] Furthermore, although the embodiment described an example of a crawler-type hydraulic excavator 1 as a construction machine, the present invention is not limited to this and can be broadly applied to other construction machines such as wheel-type hydraulic excavators, hydraulic cranes, and wheel loaders. [Explanation of Symbols]

[0057] 1. Hydraulic excavator (construction machinery) 2. Lower running body (vehicle body) 3. Upper rotating body (vehicle body) 13 Cooling fan 13A Boss 13B Feather 14 Heat exchange equipment 15 Frame 16. Radiator (First Heat Exchanger) 19. Oil cooler (second heat exchanger) 20 Space section 21. Capacitor (Third Heat Exchanger) 22 Fuel cooler 23 Cover component 23A Closed surface part 23B Front side part (side part) 23C Rear side part (side part) 24,25 Sealing member 26. Ventilation holes for capacitors (ventilation holes) 27. Ventilation holes for fuel cooler (ventilation holes)

Claims

1. A self-propelled vehicle, A cooling fan is provided on the vehicle body and has multiple blades extending radially from a central boss, which generates cooling air. In a construction machine comprising a heat exchange device provided on the vehicle body and cooled by the cooling air generated by the cooling fan, The heat exchanger described above is A first heat exchanger is positioned facing the cooling fan, A second heat exchanger is positioned in parallel with the first heat exchanger, with a gap between them, facing the cooling fan, and positioned so as to sandwich at least a portion of the boss in a plan view. A third heat exchanger is arranged in series with the first heat exchanger and the second heat exchanger relative to the cooling fan, A cover member provided between the first heat exchanger and the second heat exchanger, having ventilation holes formed therein, A frame housing the first heat exchanger and the second heat exchanger, It has, The ventilation holes are formed between the first heat exchanger and the second heat exchanger in the cover member. A construction machine characterized in that the cover member, the first heat exchanger, and the second heat exchanger are each attached to the frame.

2. In the construction machine described in claim 1, The construction machine is characterized in that the ventilation holes consist of a plurality of holes positioned facing the third heat exchanger.

3. In the construction machine described in claim 1, A construction machine characterized in that the first heat exchanger and the second heat exchanger are a radiator for cooling the coolant of the prime mover and an oil cooler for cooling the hydraulic oil.

4. A vehicle body capable of self-propulsion, A cooling fan is provided on the vehicle body and has multiple blades extending radially from a central boss, which generates cooling air. In a construction machine comprising a heat exchange device provided on the vehicle body and cooled by the cooling air generated by the cooling fan, The heat exchanger described above is A first heat exchanger is positioned facing the cooling fan, A second heat exchanger is positioned in parallel with the first heat exchanger, with a gap between them, facing the cooling fan, and positioned so as to sandwich at least a portion of the boss in a plan view. A third heat exchanger is arranged in series with the first heat exchanger and the second heat exchanger relative to the cooling fan, It includes a cover member provided between the first heat exchanger and the second heat exchanger, having ventilation holes formed therein, The ventilation holes are formed between the first heat exchanger and the second heat exchanger in the cover member. The cover member has a closing surface portion extending between the first heat exchanger and the second heat exchanger, and a pair of side portions that are bent and extend from the widthwise edge of the closing surface portion. A construction machine characterized in that a sealing member is provided between the pair of side portions and the first heat exchanger and the second heat exchanger to fill the gap.

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