JP2019157692A - Construction machine - Google Patents

Abstract

To provide a construction machine which improves heat balance related to various types of cooling while preventing cooling air having an increased temperature from being supplied to a heat exchanger again.SOLUTION: A lower surface of a revolving frame 6 is provided with an undercover 15 located below an engine 8. The undercover 15 is provided with a hose insertion opening 17 formed as an opening located at the downstream side of a cooling fan 11 in a cooling air flow direction. Further, the undercover 15 is provided with a wind guide opening 18 which is disposed between the cooling fan 11 and the hose insertion opening 17 and discharges cooling air that has passed through a heat exchanger 10 to the outside in a direction away from the heat exchanger 10.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a construction machine such as a hydraulic excavator configured to discharge cooling air that has passed through a heat exchanger, for example, from an opening of an under cover disposed below a prime mover.

  In general, a hydraulic excavator as a typical example of a construction machine is a self-propelled lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body and forms a vehicle body with the lower traveling body, It is comprised by the front apparatus provided in the front side so that the raising / lowering operation | movement was possible.

  The upper swing body includes a swing frame as a vehicle body frame that has a support structure and a front device attached to the front side, an engine as a prime mover that is provided in a horizontal state extending left and right with respect to the swing frame, and an engine A heat exchanger disposed on one side of the left and right directions, and a suction-type cooling fan provided between the heat exchanger and the engine for circulating cooling air sucked from the outside to the heat exchanger; And a building cover surrounding the engine and the heat exchanger and forming a machine room therein.

  An under cover for closing the machine room from the lower side is provided on the lower surface of the swivel frame. The under cover is provided with an opening for discharging the cooling air whose temperature has risen through the heat exchanger to the outside of the machine room (see, for example, Patent Document 1).

Japanese Utility Model Publication No. 7-30321

  In Patent Document 1, an exhaust opening is provided below the cooling fan. In this case, the exhaust opening can discharge a part of the cooling air immediately after passing through the heat exchanger, but most of the cooling air flows to the engine side. Here, the machine room is divided into an engine room and a pump room by a firewall provided at a boundary position between the engine and the hydraulic pump. Therefore, most of the cooling air is discharged from the engine compartment to the outside, so that the exhaust opening of Patent Document 1 disposed below the cooling fan can efficiently discharge the cooling air. Can not.

  Further, in Patent Document 1, all the cooling air discharge ports are louvers so that the cooling air whose temperature has risen is not sucked into the machine room again, and the louver guides and discharges the cooling air to the side opposite to the suction side. is doing. However, since the louver has a small passage area through which cooling air flows compared to a general opening, it is difficult to distribute the cooling air efficiently. When all the outlets are louvers, the heat balance in the machine room is established. There is no fear.

  Further, the engine is provided with a hose for discharging various drains, and the under cover needs to be provided with an opening for passing the drain hose. In this case, since the louver cannot be provided in the opening for passing the drain hose, there is a possibility that the cooling air discharged from the opening for the drain hose may enter the upstream side of the heat exchanger and be sucked. There is a problem that the cooling efficiency by the exchanger decreases.

  The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to improve the heat balance related to various types of cooling while preventing the cooling air whose temperature has been increased from being supplied to the heat exchanger again. It is to provide a construction machine that can improve reliability.

  The present invention relates to a vehicle body frame, a prime mover provided on the vehicle body frame, a heat exchanger provided on the vehicle body frame, and a suction-type cooling fan that distributes cooling air sucked from the outside to the heat exchanger. And an under cover provided on the lower surface of the vehicle body frame and positioned below the prime mover, wherein the under cover is downstream of the cooling fan in the flow direction of the cooling air. An opening is provided on the side, and the under cover is disposed between the cooling fan and the opening, and the cooling air that has passed through the heat exchanger is directed away from the heat exchanger. It is set as the structure which provides the baffle opening discharged | emitted outside.

  According to the present invention, it is possible to prevent the cooling air whose temperature has risen from being supplied to the heat exchanger again, and to improve the reliability by improving the heat balance related to various types of cooling.

1 is a front view showing a hydraulic excavator according to a first embodiment of the present invention. It is an expanded sectional view which fractures | ruptures the rear part of an upper revolving body from the arrow II-II direction, and shows the hydraulic shovel of FIG. It is a top view which expands and shows a turning frame and an undercover. It is a top view which expands and shows a single undercover. It is sectional drawing which looked at the undercover from the arrow VV direction in FIG. It is a top view which shows the undercover by the 2nd Embodiment of this invention. It is a top view which shows the undercover by the 3rd Embodiment of this invention.

  Hereinafter, as a typical example of a construction machine according to an embodiment of the present invention, a crawler type hydraulic excavator will be described as an example, and will be described in detail according to the accompanying drawings.

  1 to 5 show a first embodiment of the present invention. In FIG. 1, a hydraulic excavator 1 as a construction machine includes a crawler-type lower traveling body 2 that can be self-propelled, and an upper revolving body 4 that is mounted on the lower traveling body 2 via a swivel device 3 so as to be capable of turning. And a front device 5 provided on the front side of the upper swing body 4 so as to be capable of raising and lowering. The front device 5 performs excavation work of earth and sand.

  The turning frame 6 constitutes a vehicle body frame that forms a support structure of the upper turning body 4. As shown in FIG. 3, the revolving frame 6 includes a flat bottom plate 6A made of a thick steel plate or the like that extends in the front and rear directions, and a left and right that are erected on the bottom plate 6A and intersect the front and rear directions. The left vertical plate 6B and the right vertical plate 6C extending in the front and rear directions with a predetermined interval in the direction and the bottom plate 6A and the respective vertical plates 6B and 6C are projected outward in the left and right directions, and forward and backward. A plurality of overhanging beams 6D provided at intervals, and left side frames 6E and right attached to the front end side of each of the overhanging beams 6D, extending forward and rearward with intervals in the left and right directions of the vertical plates 6B and 6C. The side frame 6F is included.

  As shown in FIG. 2 and FIG. 3, the bottom plate 6A is located on the front side and is formed wide in the left and right directions, and a wide plate portion 6A1 to which the turning device 3 is attached, and from the wide plate portion 6A1 to the rear side. The narrow plate portion 6A2 extends and has the same width as the left and right vertical plates 6B and 6C. The narrow plate portion 6A2 extends to the rear side of the engine 8 described later. In the narrow plate portion 6A2, a maintenance opening 6A3 is formed below the engine 8 (oil pan 8A). The maintenance opening 6A3 is an opening for performing maintenance of the engine 8, for example, and is normally closed by an under cover 15 described later.

  Further, four engine support bases 6G are provided on the rear side of the turning frame 6 so as to surround the maintenance opening 6A3. An engine 8 can be attached to each engine support 6G via an engine mount (not shown). In addition to the under cover 15, another under cover 15 is attached to the revolving frame 6 so as to cover the space between the bottom plate 6 </ b> A and the side frames 6 </ b> E and 6 </ b> F.

  The counterweight 7 is attached to the rear side of the revolving frame 6, that is, the rear portions of the left and right vertical plates 6B and 6C. The counterweight 7 has a weight balance with the front device 5 and is formed as a heavy object having a convex arcuate rear surface.

  The engine 8 constitutes a prime mover, and is provided at a rear position of the revolving frame 6 on the front side of the counterweight 7 in a lateral state extending leftward and rightward with respect to the revolving frame 6. A cooling fan 11 is provided on the left side of the engine 8 for supplying cooling air to a heat exchanger 10 described later. On the other hand, a hydraulic pump 9 described later is attached to the right side of the engine 8.

  Further, the engine 8 is adapted to lubricate and cool each part with engine oil. For this reason, an oil pan 8A for storing engine oil is provided in the lower part of the engine 8. Further, the engine 8 is provided with a drain hose 8B extending downward, for example, for discharging water or the like in the engine 8. The leading end side (lower end side) of the drain hose 8 </ b> B extends to the outside of the machine chamber 13 through the hose insertion opening 17 of the under cover 15.

  The hydraulic pump 9 is provided on the right side of the engine 8. The hydraulic pump 9 is rotationally driven by the engine 8 to discharge hydraulic oil supplied from a hydraulic oil tank (not shown) as pressure oil toward a control valve device (not shown).

  The heat exchanger 10 is disposed on the left side, which is one side in the left and right directions with respect to the engine 8, and is attached to the revolving frame 6. The heat exchanger 10 is configured to include a radiator that cools engine coolant, an oil cooler that cools hydraulic oil, a frame that surrounds these, and the like.

  The cooling fan 11 is provided between the heat exchanger 10 and the engine 8 and is rotated by, for example, the engine 8. This cooling fan 11 is arranged on a straight line with the heat exchanger 10 and the engine 8 in the left and right directions, and draws in cooling air sucked from the outside of the building cover 12 described later to the heat exchanger 10. It is configured as. The cooling fan 11 supplies the cooling air to the heat exchanger 10 by sucking the cooling air from the outside. Further, the cooling air whose temperature has risen after passing through the heat exchanger 10 flows around the engine 8, and is discharged to the outside from the exhaust port (not shown) of the building cover 12 and the air guide opening 18 of the under cover 15. . The cooling fan 11 may be separated from the engine 8 and rotated using an electric motor or a hydraulic motor.

  The building cover 12 is provided on the revolving frame 6 so as to be positioned between a cab 22 and a counterweight 7 which will be described later. The building cover 12 covers equipment mounted on the revolving frame 6 including the engine 8, the hydraulic pump 9, and the heat exchanger 10. Specifically, the building cover 12 is positioned on the upper side of each of the cover portions 12A and 12B, the left surface cover portion 12A covering the left side of the heat exchanger 10, the right surface cover portion 12B covering the right side of the hydraulic pump 9 and the like. The engine 8, the hydraulic pump 9, and the upper surface cover portion 12 </ b> C covering the upper side of the heat exchanger 10 are configured.

  Here, an intake port 12A1 for sucking outside air is provided at an upper position of the left surface cover portion 12A on the upstream side in the flow direction of the cooling air. On the other hand, an exhaust port (not shown) for discharging the cooling air whose temperature has increased is provided on the right side portion of the upper surface cover portion 12C, which is on the downstream side in the flow direction of the cooling air.

  A machine room 13 that covers the engine 8, the hydraulic pump 9, and the heat exchanger 10 is formed inside the building cover 12. The machine room 13 is formed as a long space in the left and right directions covered by the left side cover part 12A, the right side cover part 12B, the upper surface cover part 12C, the revolving frame 6 and the under cover 15 described later. ing. On the other hand, the machine chamber 13 is divided into a suction chamber 13A located upstream in the flow direction of the cooling air, an engine chamber 13B in which the engine 8 is disposed, and a pump chamber 13C in which the hydraulic pump 9 is disposed. Yes. The suction chamber 13A and the engine chamber 13B are partitioned by the heat exchanger 10, and the engine chamber 13B and the pump chamber 13C are partitioned by a firewall 14 described later.

  The firewall 14 is disposed at a boundary position between the engine 8 and the hydraulic pump 9 and extends upward and downward across the revolving frame 6 and the upper surface cover portion 12C of the building cover 12. The firewall 14 blocks between the engine 8 and the hydraulic pump 9. Accordingly, the firewall 14 can prevent the leaked hydraulic oil from scattering to the engine 8 side even when the hydraulic oil leaks around the hydraulic pump 9.

  Here, since the firewall 14 blocks the cooling air flowing around the engine 8 by the cooling fan 11, the cooling air whose flow is blocked is discharged from the engine chamber 13B to the outside. At this time, the cooling air is exhausted through an exhaust port of the upper surface cover portion 12C and an air guide opening 18 of the under cover 15 described later.

  Next, the configuration of the under cover 15 which is a characteristic part of the present embodiment and the cooling air discharge direction will be described in detail.

  As shown in FIGS. 2 and 3, the under cover 15 is provided on the lower surface of the bottom plate 6 </ b> A that constitutes the revolving frame 6 that is positioned below the engine 8. The under cover 15 closes the machine room 13 from the lower side in cooperation with the other under covers 20 and 21. The under cover 15 covers the maintenance opening 6A3 of the bottom plate 6A. The under cover 15 is attached to the narrow plate portion 6A2 of the bottom plate 6A from below using a plurality of screw members 16 so as to be removable.

  As shown in FIGS. 4 and 5, the under cover 15 is formed as a rectangular plate so as to extend along the engine 8. Around the under cover 15, a plurality of, for example, five screw insertion holes 15A through which the screw members 16 are inserted are provided. The under cover 15 is formed with an air guide opening 18, a hose insertion opening 17, and another air guide opening 19 from the upstream side in the flow direction of the cooling air when attached to the bottom plate 6 </ b> A.

  The hose insertion opening 17 constitutes an opening, and one hose insertion opening 17 is disposed between the air guide opening 18 and the other air guide opening 19. The hose insertion opening 17 is formed as a square-shaped opening that is located on the downstream side of the cooling air with respect to the lengthwise intermediate portion of the under cover 15 and penetrates upward and downward. The hose insertion opening 17 is for inserting the drain hose 8B of the engine 8 described above. In addition, since the hose insertion opening 17 is an opening through which the drain hose 8B is inserted, the hose insertion opening 17 can have other shapes such as a rectangle and a circle in addition to the square shape.

  Here, the hose insertion opening 17 is an opening that penetrates upward and downward. Accordingly, the cooling air whose temperature has risen discharged from the machine room 13 (engine room 13B) through the hose insertion opening 17 is discharged in various directions, for example, a heat exchanger, as shown by an imaginary line arrow A. 10 side, lower side, hydraulic pump 9 side. In this case, when the cooling air whose temperature has risen flows back to the heat exchanger 10 side, it may be sucked into the suction chamber 13A of the machine room 13 again, and when it is supplied to the heat exchanger 10, the cooling performance is lowered. I will invite you.

  Therefore, in this embodiment, the under cover 15 is provided with the air guide opening 18 to prevent the cooling air whose temperature has risen from flowing back to the heat exchanger 10 side.

  The air guide opening 18 is provided in the under cover 15 and discharges cooling air whose temperature has increased in the engine compartment 13B. At this time, the air guide opening 18 discharges the cooling air in the machine room 13 to the outside in a direction away from the heat exchanger 10. The air guide opening 18 is disposed between the cooling fan 11 and the hose insertion opening 17 with the under cover 15 attached to the bottom plate 6A. As shown in FIGS. 4 and 5, the air guide opening 18 includes a plurality of slit portions 18A and louver portions 18B provided in the respective slit portions 18A.

  The slit portion 18A extends in the direction intersecting with the flow direction of the cooling air, that is, in the front and rear directions when the under cover 15 is attached to the bottom plate 6A, and is provided, for example, with nine spaces in the left and right directions. . Each slit portion 18A is formed as a vertically long D-shaped opening by forming a straight portion 18A1 on the upstream side in the flow direction of the cooling air and a curved portion 18A2 on the downstream side.

  Louver portion 18B is provided so as to cover the upper side (engine chamber 13B side) of each slit portion 18A. Each louver portion 18B opens the slit portion 18A on the heat exchanger 10 side, that is, the straight portion 18A1 side, and closes the side away from the heat exchanger 10, that is, the curved portion 18A2 side. It covers the top. Here, since the louver part 18B covers the upper side of the slit part 18A, it is possible to prevent the noise of the engine 8 from leaking to the outside and to prevent external foreign matter from entering.

  As shown in FIG. 5, the air guide opening 18 can guide the cooling air flowing through the engine chamber 13 </ b> B by each louver portion 18 </ b> B and discharge the cooling air to the outside from each slit portion 18 </ b> A. In this case, the air guide opening 18 causes the cooling air to flow along the louver portions 18B, thereby causing the direction indicated by the solid arrow B, that is, the direction away from the heat exchanger 10 (the downstream side of the cooling air flow direction). ) Can be discharged to the outside. Therefore, the cooling air discharged from the air guide opening 18 can be separated from the heat exchanger 10 by pressing the cooling air discharged from the hose insertion opening 17 in the direction indicated by the arrow C shown in white.

  The other air guide opening 19 is provided in the under cover 15 separately from the air guide opening 18. The other air guide opening 19 is disposed downstream of the hose insertion opening 17 in the flow direction of the cooling air. The other air guide openings 19 are provided with, for example, three slit portions 19A and louver portions 19B similar to the slit portions 18A and louver portions 18B of the air guide opening 18 in the left and right directions. Thereby, the other air guide openings 19 can discharge the cooling air to the outside in the direction indicated by the arrow B, similarly to the air guide openings 18.

  The revolving frame 6 is provided with other under covers 20 and 21 that cover the machine room 13 from below. The undercover 20 on the heat exchanger 10 side is provided with a wind guide opening 20A similar to the wind guide openings 18 and 19. On the other hand, the under cover 21 located under the hydraulic pump 9 is provided with an exhaust heat opening 21A composed of a plurality of round holes for discharging heat generated by the hydraulic pump 9.

  As shown in FIGS. 1 and 2, the cab 22 is provided on the left front side of the revolving frame 6. The cab 22 is used by an operator, and a driver's seat on which the operator is seated, an operation lever for traveling, an operation lever for work, and the like (all not shown) are arranged.

  The hydraulic excavator 1 according to the present embodiment has the above-described configuration, and the operation thereof will be described next.

  The operator of the excavator 1 gets on the cab 22 of the upper swing body 4 and starts the engine 8 to drive the hydraulic pump 9. Thereby, pressure oil is discharged from the hydraulic pump 9, and this pressure oil is supplied to the various hydraulic actuators of the lower traveling body 2 and the front device 5 via a control valve device (not shown).

  When an operator who has boarded the cab 22 operates an operation lever (not shown) for traveling, the vehicle can be moved forward or backward by the lower traveling body 2. On the other hand, when an operator in the cab 22 operates an operation lever (not shown) for work, the front device 5 can be moved up and down to perform excavation work of earth and sand.

  When the hydraulic excavator 1 is in operation, the cooling fan 11 is driven to rotate, thereby sucking outside air into the suction chamber 13A of the machine room 13 from the air inlet 12A1 provided in the left surface cover portion 12A of the building cover 12. The cooling air is supplied to the heat exchanger 10. Thereby, in the heat exchanger 10, an engine cooling water and hydraulic fluid can be cooled.

  On the other hand, the cooling air whose temperature has risen after passing through the heat exchanger 10 flows toward the firewall 14 in the engine room 13B. A part of the cooling air is discharged to the outside through a hose insertion opening 17, an air guide opening 18 and another air guide opening 19 provided in the under cover 15. At this time, since the hose insertion opening 17 is an opening penetrating upward and downward to allow the drain hose 8B to be inserted, the cooling air whose temperature has been exhausted from the engine chamber 13B through the hose insertion opening 17 is reduced. , It may flow backward to the heat exchanger 10 side.

  However, according to the present embodiment, the lower surface of the revolving frame 6 is provided with the under cover 15 that is located on the lower side of the engine 8 and closes the machine room 13 formed by the building cover 12 from the lower side. Yes. The under cover 15 is provided with a hose insertion opening 17 as an opening located downstream of the cooling fan 11 in the flow direction of the cooling air. Further, the under cover 15 is disposed between the cooling fan 11 and the hose insertion opening 17 and discharges the cooling air that has passed through the heat exchanger 10 to the outside in a direction away from the heat exchanger 10. 18 is provided.

  Accordingly, the air guide opening 18 discharges the cooling air that has passed through the heat exchanger 10 to the outside in a direction away from the heat exchanger 10, thereby increasing the temperature of the cooling air discharged from the hose insertion opening 17. The heat exchanger 10 can be guided away. As a result, it is possible to prevent a situation in which the cooling air whose temperature has risen is sucked again, so that the cooling efficiency of various fluids by the heat exchanger 10 can be improved.

  Since the hose insertion opening 17 and the air guide opening 18 are provided in the under cover 15 located on the lower side of the engine 8, not only the slit-like air introduction opening 18 but also the hose insertion opening 17 which is opened widely is cooled. Wind can be discharged. Thereby, the heat balance in the machine room 13 can be made favorable and reliability can be improved.

  The air guide opening 18 has a plurality of slit portions 18A extending in a direction intersecting with the flow direction of the cooling air, and opens the heat exchanger 10 side of each slit portion 18A, and the side away from the heat exchanger 10 And a plurality of louver portions 18B respectively provided so as to cover the slit portion 18A. By allowing the cooling air flowing around the engine 8 along the louver portions 18B, the cooling air can be discharged from the slit portions 18A so as to be separated from the heat exchanger 10.

  Further, in addition to the air guide opening 18, the under cover 15 is provided with another air guide opening 19 that is located downstream of the hose insertion opening 17 in the flow direction of the cooling air. Thereby, the discharge amount of the cooling air whose temperature has increased can be increased, and the heat balance in the machine room 13 can be further improved.

  Next, FIG. 6 shows a second embodiment of the present invention. The feature of this embodiment is that only the opening and the air guide opening are provided in the under cover. In the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 6, the under cover 31 according to the second embodiment is formed of a rectangular plate, like the under cover 15 according to the first embodiment, and includes the hose insertion opening 17 and the air guide opening 18 described above. Is provided. However, the under cover 31 according to the second embodiment is different from the first embodiment in that the other air guide opening 19 provided in the first embodiment is abolished. .

  Thus, also in the second embodiment configured as described above, substantially the same operations and effects as those of the first embodiment described above can be obtained. In particular, the second embodiment is suitable for a model that generates a small amount of heat in the machine room 13, for example.

  Next, FIG. 7 shows a third embodiment of the present invention. The present embodiment is characterized in that only an opening and a wind guide opening are provided in the under cover, and the opening is formed from a plurality of holes. Note that in the third embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 7, the under cover 41 according to the third embodiment is formed of a rectangular plate, like the under cover 15 according to the first embodiment, and the hose insertion opening 42 as the opening and the above-described wind guide. An opening 18 is provided. However, in the under cover 41 according to the third embodiment, the other air guide opening 19 provided in the first embodiment is eliminated, and the hose insertion opening 42 has a plurality of round holes 42A. This is different from the first embodiment in that it is formed by.

  Thus, also in the second embodiment configured as described above, substantially the same operations and effects as those of the first embodiment described above can be obtained. In particular, in the second embodiment, the hose insertion opening 42 is formed by a plurality of round holes 42A, so that foreign substances such as stones and wood chips from the outside can be prevented from entering the machine from each round hole 42A. The cooling air in the chamber 13 can be discharged efficiently.

  In the first embodiment, a case where one hose insertion opening 17 is provided in the under cover 15 is illustrated. However, the present invention is not limited to this, and two or more hose insertion openings 17 may be provided in the under cover 15.

  In the first embodiment, nine slit portions 18A and nine louver portions 18B forming the air guide opening 18 are described as an example. However, the present invention is not limited to this, and may have a configuration in which 1 to 8 or 10 or more slit portions 18A and louver portions 18B are provided. This configuration can be similarly applied to other embodiments. Further, the other air guide openings 19 may be configured such that one, two, or four or more slit portions 19A and louver portions 19B are provided.

  In the third embodiment, the case where the hose insertion opening 42 is formed by a plurality of round holes 42A is described as an example. However, the present invention is not limited to this. For example, the hose insertion opening can be formed by a plurality of holes having other shapes such as a plurality of square holes and triangular holes.

  Furthermore, in each embodiment, the crawler type hydraulic excavator 1 has been described as an example of the construction machine. However, the present invention is not limited to this, and other examples such as a wheel type hydraulic excavator, a hydraulic crane, a wheel loader, and the like. It can be widely applied to construction machines.

1 Excavator (construction machine)
2 Lower traveling body (car body)
4 Upper swing body (car body)
6 Turning frame (body frame)
8 engine (motor)
10 Heat exchanger 11 Cooling fan 15, 31, 41 Under cover 17, 42 Hose insertion opening (opening)
18 Air guide opening 18A Slit part 18B Louver part 19 Other air guide opening

Claims (4)

Body frame,
A prime mover provided in the body frame;
A heat exchanger provided on the vehicle body frame;
A suction-type cooling fan that circulates cooling air sucked from outside through the heat exchanger;
In a construction machine comprising an under cover provided on a lower surface of the vehicle body frame, located below the prime mover,
The under cover is provided with an opening located downstream of the cooling fan in the flow direction of the cooling air,
The under cover is provided with an air guide opening that is disposed between the cooling fan and the opening and exhausts the cooling air that has passed through the heat exchanger to the outside in a direction away from the heat exchanger. Construction machinery characterized by that.   The construction machine according to claim 1, wherein the cooling fan is disposed between the heat exchanger and the prime mover.   The air guide opening has a plurality of slit portions extending in a direction crossing the flow direction of the cooling air, and opens the heat exchanger side of each slit portion and closes the side away from the heat exchanger. The construction machine according to claim 1, further comprising a plurality of louver portions provided so as to cover the slit portion.   2. The undercover is provided with another air guide opening located on the downstream side of the opening in the flow direction of the cooling air separately from the air guide opening. Construction machinery.

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