Construction machine

Abstract

To provide a construction machine capable of sufficiently removing and discharging dust attached on a dust protection net when cleaning by a reverse rotation of a cooling fan.SOLUTION: A hydraulic excavator 1 is provided with: a housing cover 24 covering a machine room 9; a cooling fan 21 placed in the machine room 9; a heat exchanger 20 arranged in the machine room 9 and placed between the housing cover 24 and the cooling fan 21; and a controller 28 capable of driving the cooling fan as selectively switching between normal rotation and reverse rotation of the cooling fan 21, comprising an opening 25 arranged on a left side surface 24A of the housing cover 24, a dust protection net 26 arranged between the left side surface 24A of the housing cover 24 and the heat exchanger 20, and a discharge port 29 positioned between the left side surface 24A of the housing cover 24 and the dust protection net 26 in a lower surface 9A of the machine room 9 and arranged on a specific part outside of the specific area below the cooling fan 21.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a construction machine equipped with a cooling fan in a machine room. [Background technology]

[0002] Patent Document 1 discloses a recycling machine that includes a self-propelled running body, crushing means installed on the running body, loading means for loading materials to be crushed into the crushing means, unloading means for unloading materials crushed by the crushing means, and drive means equipped with a power engine that generates power to drive the running body, crushing means, and unloading means.The recycling machine is characterized by the fact that it is equipped with a cooling fan that draws outside air into an engine compartment that houses the power engine and cools a heat exchanger installed in the engine compartment, a dustproof net that is attached to the heat exchanger and removes dust and other particles that are drawn in along with the outside air, an exhaust outlet that opens below the dustproof net, and a lid that is attached to the exhaust outlet and can be opened and closed freely so that it opens when the air pressure in the engine compartment increases.

[0003] In Patent Document 1, during normal operation, the cooling fan is rotated to draw air from outside the building cover through an opening in the building cover, and the airflow cools the heat exchanger and is then discharged downstream. At this time, a dustproof net is provided upstream of the heat exchanger to prevent the drawn-in dust from adhering to the heat exchanger.

[0004] Dust that has adhered to the dustproof net during the cooling by the airflow can be discharged from the opening in the building cover by rotating the cooling fan in reverse when the normal work is stopped and cleaning is performed. In particular, in Patent Document 1, a lid that opens and closes due to the pressure of the airflow during reverse rotation is provided on a main frame installed at the bottom of the building cover, and when the lid opens during the reverse rotation, dust that has not been discharged from the opening and remains in the space inside the building cover falls and is discharged. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-307464 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when a lid is provided on the main frame as in Patent Document 1, the airflow tends to flow to a portion of the flow path where pressure loss is small, and there is a risk that most of the airflow will escape from the lid. As a result, when the cooling fan rotates in reverse during cleaning, the wind speed above the dustproof net decreases, and there is a concern that dust will not be blown away sufficiently. Patent Document 1 did not necessarily take such points into consideration.

[0007] The present invention has been made in consideration of the above circumstances, and its object is to provide a construction machine that can sufficiently remove and discharge dust adhering to a dustproof net when cleaning is performed by rotating the cooling fan in reverse. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the present invention provides a construction machine comprising a machine room, a building cover covering the machine room, a cooling fan arranged in the machine room, a heat exchanger arranged in the machine room between the building cover and the cooling fan, and a control device capable of selectively switching the cooling fan between forward and reverse rotation, characterized in that the construction machine has an opening provided on a side of the building cover, a dustproof net provided between the side of the building cover and the heat exchanger, and a dust exhaust outlet located on the underside of the machine room, between the side of the building cover and the dustproof net, and provided at a specified location outside a specified area below the cooling fan. [Effects of the Invention]

[0009] According to the present invention, when cleaning is performed by rotating the cooling fan in reverse, dust adhering to the dustproof net can be sufficiently removed and discharged. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a side view showing an example of the overall structure of a hydraulic excavator according to an embodiment of the present invention. [Figure 2] 2 is a schematic perspective view showing an example of an arrangement of equipment on an upper rotating body provided in the hydraulic excavator of FIG. 1, as viewed from above the rotating body. FIG. [Figure 3] FIG. 2 is a horizontal cross-sectional view schematically showing the detailed arrangement of equipment in a machine room. [Figure 4] FIG. 2 is a vertical cross-sectional view schematically showing the detailed arrangement of equipment in a machine room. [Figure 5] FIG. 2 is a block diagram showing an example of a configuration related to control of a cooling fan. [Figure 6] FIG. 4 is an explanatory diagram showing a method for controlling the rotation speed of a cooling fan. [Figure 7] 10 is a schematic diagram showing a detailed configuration of the vicinity of the opening on the left side of the building cover in a comparative example of the present invention. FIG. [Figure 8] FIG. 2 is a vertical cross-sectional view schematically showing the detailed arrangement of equipment in a machine room. [Figure 9] 1 is a schematic diagram showing a detailed configuration of the vicinity of the opening on the left side of the building cover in one embodiment of the present invention. FIG. [Figure 10] FIG. 2 is a vertical cross-sectional view schematically showing the detailed arrangement of equipment in a machine room. [Figure 11] FIG. 10 is a schematic diagram showing the detailed configuration of the vicinity of the opening on the left side of the building cover in a modified example in which multiple cooling fans are provided corresponding to each heat exchanger. [Figure 12] FIG. 2 is a vertical cross-sectional view schematically showing the detailed arrangement of equipment in a machine room. [Figure 13] 10 is a schematic diagram showing a detailed configuration near the opening on the left side of the building cover in a modified example in which only some cooling fans continue to rotate in reverse and the others stop rotating in reverse. FIG. [Figure 14] FIG. 4 is an explanatory diagram showing a method for controlling the rotation speed of a cooling fan. [Figure 15]10 is a schematic diagram showing the behavior of cleaning air in a comparative example in which all cooling fans are driven to rotate in reverse, and illustrating the detailed configuration of the vicinity of the opening on the left side of the building cover. FIG. [Figure 16] 4 is a flowchart showing a cooling fan control procedure executed by a controller. [Figure 17] FIG. 10 is a schematic diagram showing an example of a group that may be collectively controlled among the variations of control combinations for stopping or continuing reverse rotation drive of the cooling fan. [Figure 18] FIG. 10 is a schematic diagram showing an example of a group that may be collectively controlled among the variations of control combinations for stopping or continuing reverse rotation drive of the cooling fan. [Figure 19] FIG. 10 is a schematic diagram showing an example of a group that may be collectively controlled among the variations of control combinations for stopping or continuing reverse rotation drive of the cooling fan. [Figure 20] FIG. 10 is a schematic diagram showing an example of a group that may be collectively controlled among the variations of control combinations for stopping or continuing reverse rotation drive of the cooling fan. [Figure 21] FIG. 10 is a schematic diagram showing an example of a group that may be collectively controlled among the variations of control combinations for stopping or continuing reverse rotation drive of the cooling fan. [Figure 22] FIG. 10 is a schematic diagram showing an example of a group that should not be controlled collectively among the variations of control combinations for stopping and continuing reverse rotation drive of a cooling fan. [Figure 23] FIG. 10 is a schematic diagram showing an example of a group that should not be controlled collectively among the variations of control combinations for stopping and continuing reverse rotation drive of a cooling fan. [Figure 24] FIG. 10 is a schematic diagram showing an example of a group that should not be controlled collectively among the variations of control combinations for stopping and continuing reverse rotation drive of a cooling fan. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] <Overall configuration of hydraulic excavator> In this embodiment, a crawler hydraulic excavator will be described as an example of the construction machine. In the following description, the up-down direction, the front-rear direction, and the left-right direction correspond to the directions of arrows appropriately shown in each drawing such as FIG.

[0013] 1, the hydraulic excavator 1 includes a traveling body 3, a rotating body 4 that is provided on the traveling body 3 so as to be rotatable by a rotating motor (not shown), and a working device 12 attached to the rotating body 4. The working device 12 includes a boom 5 attached to the rotating body 4 so as to be able to move up and down, an arm 6 attached to the tip of the boom 5 so as to be able to move up and down, a bucket 7 attached to the tip of the arm 6 so as to be able to move up and down, a boom cylinder 13 that operates the boom 5, an arm cylinder 15 that operates the arm 6, and a bucket cylinder 16 that operates the bucket 7.

[0014] The traveling body 3 has a pair of left and right crawler tracks 2 and a pair of left and right traveling motors 11 that drive the crawler tracks 2. The rotating body 4 has a main frame 14, a counterweight 10, a cab 8, and a building cover 24. The main frame 14 is the base of the rotating body 4, and is made up of a plurality of steel plates and steel materials joined together to form a support structure extending in the front-rear and left-right directions of the vehicle body. The working device 12 is attached to the front of the main frame 14 so that it can be raised and lowered. The counterweight 10 is installed on the rear of the main frame 14 and serves as a weight to balance the weight of the work implement 12. The operator's cab 8 is mounted on the front left side of the main frame 14.

[0015] As shown in FIG. 2, inside the cab 8, a driver's seat 50 where an operator sits and a controller 28 (control device) are provided. The building cover 24 is a cover that separates the engine 23, heat exchanger 20, and other equipment mounted on the main frame 14, and the machinery room 9 located at the rear of the vehicle body is provided inside the building cover 24. Inside the machinery room 9, the engine 23 is mounted horizontally with the crankshaft oriented in the left-right direction, a hydraulic pump 62 directly connected to the engine 23, the heat exchanger 20, and the like are mounted.

[0016] <Details of the machine room> Fig. 3 is a horizontal cross-sectional view showing a schematic diagram of the detailed arrangement of equipment in the machine room 9, and Fig. 4 is a vertical cross-sectional view. In Figs. 3 and 4, the machine room 9 is equipped with the heat exchanger 20, a cooling fan 21 which is a suction type fan in this example, a casing 22 to which the heat exchanger 20 and the cooling fan 21 are fixed, and the engine 23.

[0017] The heat exchanger 20 includes a plurality of appropriate heat exchangers. These heat exchangers (in this example, an oil cooler 17, a radiator 18, and an intercooler 19) are disposed between the building cover 24 and the cooling fan 21, and are arranged in parallel with the flow of cooling air generated by the cooling fan 21, as shown in FIGS. 3 and 4 . The oil cooler 17 cools the hydraulic oil used to drive the working implement 12. The radiator 18 cools the engine coolant. The intercooler 19 cools the intake air supplied to the engine 23 by a turbocharger (not shown). Temperature sensors 30, 31, and 32 (see FIG. 5 , described later) are also attached to the heat exchangers 20. The cooling fan 21 is driven by a fan drive unit 27, selectively switching between forward and reverse rotation, to generate cooling air that cools the heat exchanger 20. The fan drive unit 27 is controlled based on a rotation speed command from a controller 28.

[0018] An opening 25 is provided on the left side surface 24A of the building cover 24, and a dustproof net 26 is provided between the left side surface of the building cover 24 and the heat exchanger 20. In this example, the openings 25 are provided in the form of horizontal windows arranged in three rows, top and bottom (see FIG. 1 and FIG. 9 described below).

[0019] The machine room 9 has a lower surface 9A, and an exhaust port 29 (dust exhaust port) is provided in a portion (predetermined portion) of the lower surface 9A located between the left side surface 24A of the building cover 24 and the dustproof net 26. The portion of the lower surface 9A other than the exhaust port 29 forms a closed surface 9B without any openings. In other words, the predetermined portion is a portion of the lower surface 9A of the machine room 9 that is outside a projected area A (predetermined area) of the cooling fan 11 projected onto the lower surface 9A of the machine room 9 when the cooling fan 21 is viewed from the opening 25 side (see FIG. 9 described below). In this example, the exhaust ports 29 are arranged at two locations on one side and the other side of the predetermined area (projected area A) of the lower surface 9A of the machine room 9, in other words, at two locations on the front and rear sides of the closed surface 9B.

[0020] <Configuration related to cooling fan control> An example of a configuration related to the control of cooling fan 21 is shown in Fig. 5. In Fig. 5, an oil cooler temperature sensor 30, a radiator temperature sensor 31, and an intercooler temperature sensor 32 are provided in the flow paths of hydraulic oil flowing in oil cooler 17, engine cooling water flowing in radiator 18, and intake air flowing in intercooler 19, respectively.

[0021] The oil cooler temperature sensor 30 detects the temperature of the hydraulic oil and transmits the detected oil cooler temperature To to the controller 28. The radiator temperature sensor 31 detects the temperature of the engine cooling water and transmits the detected radiator temperature Tr to the controller 28. The intercooler temperature sensor 32 detects the temperature of the intake air and transmits the detected intercooler temperature Ti to the controller 28.

[0022] The controller 28 includes a detector 35 that receives each signal, a recorder 36 that stores a correlation table, and a calculator 37 that calculates the target rotation speed of the cooling fan 21 . 6, for an oil cooler temperature To received by a detection unit 35 from an oil cooler temperature sensor 30, a To-No correlation table stored in a recording unit 36 ​​is referenced, and a corresponding target rotation speed No of the cooling fan 21 is determined by a calculation unit 37. Similarly, for a radiator temperature Tr from a radiator temperature sensor 31, a Tr-Nr correlation table is referenced, and a corresponding target rotation speed Nr of the cooling fan 21 is determined by a calculation unit 37. Similarly, for an intercooler temperature Ti from an intercooler temperature sensor 32, a Ti-Ni correlation table is referenced, and a corresponding target rotation speed Ni of the cooling fan 21 is determined by a calculation unit 37. The maximum value of the three target rotation speeds No, Nr, Ni determined as described above is selected by the calculation unit 37 and output from the controller 28 to the fan drive device 27 as the final rotation speed command value N.

[0023] <Forward and reverse rotation of the cooling fan> Cooling fan 21 is driven by fan drive device 27 as described above (= forward rotation drive; reverse rotation drive will be described later), thereby drawing in outside air into machine room 9 through opening 25 and generating cooling air, as shown by the outline arrow in FIG. 4. The generated cooling air passes through dustproof net 26 and is blown onto heat exchanger 20, cooling it.

[0024] Here, construction machinery such as the hydraulic excavator 1 may operate in a dusty environment, and if cooling air containing dust is sucked into the machine room 9, this may have an adverse effect on the heat exchange performance of the heat exchanger 20. For this reason, the dustproof net 26 is provided upstream of the heat exchanger 20 in the flow of cooling air when the cooling fan 21 is rotating in the forward direction, and the dustproof net 26 captures dust in the cooling air.

[0025] Generally, the dustproof net 26 is designed to be removable and cleanable, but frequent removal and cleaning of the dustproof net 26 places a strain on the worker. Therefore, by rotating the cooling fan 21 in the reverse direction using the fan drive device 27, an airflow from right to left (see Figures 9 and 8, etc., described below; hereinafter referred to as "cleaning airflow") is generated in the opposite direction to the outline arrow in Figure 4, and the dust adhering to the dustproof net 26 is blown away by the cleaning airflow. The cooling fan 21 is driven to rotate in reverse when a reverse rotation execution switch 33 is operated, and the reverse rotation is stopped when a reverse rotation stop switch 34 is operated. These switches 33 and 34 are provided in the driver's cab 8, for example.

[0026] Dust blown off the dustproof net 26 by the cleaning wind is discharged to the outside of the machine room 9 through an opening 25 provided in the left side surface 24A of the building cover 24. At that time, some of the dust collides with a frame portion 24B (= the portion other than the opening 25; see Figures 8 and 10 described below) on the left side surface 24A of the building cover 24 and falls onto the underside 9A of the machine room 9. If left as is, this dust may adhere again to the dustproof net 26 due to the cooling wind generated when the cooling fan 21 is subsequently driven in the forward direction. To prevent this, the above-mentioned exhaust port 29 is provided, which discharges the fallen dust below the machine room 9 as described above.

[0027] <Features of the embodiment> The feature of this embodiment, which has the above-described configuration and basic operation, is the position of the discharge port 29 on the lower surface 9A of the machine chamber 9. The technical significance of this will be described in detail below using a comparative example.

[0028] <Discharge outlet arrangement in comparative example> A comparative example of this embodiment will be described with reference to Figures 7 and 8. Figure 7 is a schematic diagram equivalent to an enlarged view of part P in Figure 1, showing a detailed configuration in the vicinity of opening 25 in this comparative example, and Figure 8 is a vertical cross-sectional view equivalent to the above-mentioned Figure 4, showing the flow behavior of cleaning air in this comparative example.

[0029] 7 and 8, the flow of cleaning air blown out from cooling fan 21 as described above reaches left side surface 24A of building cover 24. At this time, as described above, the flow of cleaning air includes component W1' (see the white arrow pointing left in FIG. 8) that travels substantially horizontally and flows out from opening 25, and component W2' (see the gray arrow pointing left and downward in FIG. 8) that does not flow out from opening 25 but collides with frame portion 24B of left side surface 24A of building cover 24 and bends downward. Component W2' that collides with frame portion 24B and bends flows out from outlet 29 on the underside 9A of machine room 9 to below machine room 9.

[0030] In this comparative example, as shown in Fig. 7, one large exhaust port 29 is arranged on the underside 9A of the machine room 9, inside the range obtained by projecting the cooling fan 21 onto the left side surface 24A (=inside the projected area A). In general, air tends to flow toward a portion of the flow path where pressure loss is small, so there is a risk that most of the cleaning airflow will flow out from the exhaust port 29. As a result, as shown in Fig. 8, for both of the components W1' and W2', the air volume increases toward the lower side in the height direction and decreases toward the upper side, so the air velocity passing over the dustproof net 26 decreases, and there is a concern that dust adhering to the dustproof net 26 may not be sufficiently blown away.

[0031] <Discharge outlet arrangement in the embodiment> 9 and 10, which correspond to FIGS. 7 and 8 of the comparative example, show a detailed configuration near the opening 25 and the flow behavior of the cleaning air in this embodiment. Similar to the comparative example, in FIGS. 9 and 10, the flow of the cleaning air includes a component W1 (see the left-pointing white arrow in FIG. 10) that travels substantially horizontally and flows out of the opening 25, and a component W2 (see the left-pointing and downward-pointing gray arrows in FIGS. 9 and 10) that does not flow out of the opening 25 but collides with the frame portion 24B on the left side surface 24A of the building cover 24 and bends downward. Component W2 that collides with the frame portion 24B and bends flows out from the exhaust port 29 on the underside 9A of the machine room 9 to below the machine room 9.

[0032] 9, in this embodiment, on the underside 9A of the machine room 9, the two exhaust ports 29 are arranged outside the range projected when the cooling fan 21 is viewed from the left side surface 24A (= outside the projected area A of the cooling fan 21 projected onto the underside 9A). In particular, in this example, the exhaust ports 29 are arranged at a position closest to the building cover 24 within the machine room 9. Therefore, even if the component W2 continues to descend after bending downward at the frame portion 24B, it will not reach the exhaust ports 29. In other words, after the component W2 descends and collides with the underside 9A of the machine room 9 as described above, it further bends in a direction approximately parallel to the underside 9A of the machine room 9 and the left side surface 24A of the building cover 24 before reaching the exhaust ports 29. As a result, the flow path of the component W2 has a bent shape, which causes a certain amount of pressure loss. As a result, the airflow during cleaning, both component W1 and component W2, flows in a state where the air volume on the lower side and the air volume on the upper side in the height direction are well balanced.

[0033] <Effects of the embodiment> As described above, in the hydraulic excavator 1 of this embodiment, during cleaning, the cooling fan 21 is driven to rotate in the reverse direction by the controller 28. The airflow generated thereby passes from the cooling fan 21 in a substantially horizontal direction through the dustproof net 26, and then includes two flows (component W1 and component W2). Component W1 is a flow that passes through the dustproof net 26, then continues in a substantially horizontal direction, and flows out of the building cover 24 through the opening 25 provided in the left side surface 24A of the building cover 24. Component W2 is a flow that passes through the dustproof net 26, then collides with a portion of the left side surface 24A of the building cover 24 other than the opening 25 (frame portion 24B), turns downward, and then flows out downward from the discharge port 29 provided in the underside 9A of the machine room 9.

[0034] In this embodiment, the exhaust port 29 is located on the underside 9A of the machine room 9, outside the projected area A (predetermined region) as viewed from the left side surface 24A of the cooling fan 21, so that the flow path of the component W2 has a meandering shape, resulting in a certain degree of pressure loss. As a result, the airflow during cleaning is balanced evenly between the lower and upper sides in the vertical direction for both the component W1 and the component W2, so that the upper side airflow is not reduced and the air speed above the dustproof net 26 does not decrease, as in the prior art. Therefore, according to this embodiment, dust adhering to the dustproof net 26 can be sufficiently removed and discharged during cleaning with the cooling fan 21 rotating in reverse.

[0035] In particular, in this embodiment, the portion of the underside 9A located between the left side surface 24A of the building cover 24 and the dustproof net 26 other than the exhaust port 29 is a closed surface 9B without any openings. This ensures that the flow path of the component W2 of the cleaning airflow has a bent shape.

[0036] In particular, in this embodiment, the exhaust ports 29 are provided on one side and the other side of the projected area A, substantially along the left side surface 24A. As a result, the component W2 of the cleaning air that collides with the closing surface 9B of the lower surface 9A of the machine chamber 9 branches into two, one on each side of the closing surface 9B, and reaches each of the two exhaust ports 29 (see FIG. 9). The flow path shape of the branching component W2 in this manner can reliably cause a certain degree of pressure loss.

[0037] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and technical concept of the present invention. Such modifications will be described below in order. The same reference numerals will be used to designate parts equivalent to those in the above-described embodiment, and descriptions will be omitted or simplified as appropriate.

[0038] (1) When multiple cooling fans are provided for each heat exchanger A detailed configuration near the opening 25 and the flow behavior of the cleaning air in this modified example are shown in FIGS. 11 and 12, which correspond to FIGS. 9 and 10 of the above embodiment, respectively.

[0039] 11 and 12, in this modification, a plurality of cooling fans (six cooling fans in this example, 38U, 38L, 39U, 39L, 40U, 40L) are provided in the vertical direction corresponding to each heat exchanger 20. That is, upper and lower two-tiered cooling fans 38U, 38L are provided to cool the oil cooler 17, upper and lower two-tiered cooling fans 39U, 39L are provided to cool the radiator 18, and upper and lower two-tiered cooling fans 40U, 40L are provided to cool the intercooler 19. Also, as shown in FIG. 11, four exhaust ports 29A, 29B, 29C, 29D are provided on a lower surface 9A of the machine chamber 9. As in the above embodiment, a component W2 (see gray arrow in Figure 11) of the cleaning air flow that does not flow out through the opening 25 but collides with the frame portion 24B of the building cover 24 and bends downward flows out from the above-mentioned exhaust ports 29A to 29D on the underside 9A of the machine room 9 to below the machine room 9.

[0040] In this case, the outlets 29A, 29B, 29C, and 29D on the lower surface 9A of the machine chamber 9 are arranged outside the projected area A of the corresponding cooling fans 38U, 38L, 39U, 39L, 40U, and 40L. That is, with regard to the cooling fans 38U, 38L, the aforementioned predetermined portions are portions of the underside 9A of the machine chamber 9 that are outside a projected area A (predetermined region) of the cooling fans 38U, 38L projected onto the underside 9A of the machine chamber 9 when the cooling fans 38U, 38L are viewed from the opening 25 side. The corresponding exhaust ports 29A, 29B are disposed outside the projected area A. As a result, after colliding with the underside 9A, component W2 of the cleaning airflow from the cooling fans 38U, 38L branches in the left and right directions shown in FIG. 11 , turns in directions substantially parallel to the left side surface 24A, and reaches the exhaust ports 29A, 29B. Similarly, with regard to the cooling fans 39U, 39L, the aforementioned predetermined portion is a portion of the underside 9A of the machine chamber 9 that is outside a projected area A (predetermined region) of the cooling fans 39U, 39L projected onto the underside 9A of the machine chamber 9 when the cooling fans 39U, 39L are viewed from the opening 25 side. By arranging the corresponding exhaust ports 29B, 29C outside the projected area A, the component W2 of the cleaning air from the cooling fans 39U, 39L collides with the underside 9A, then branches off in the left and right directions in FIG. 11 and reaches the exhaust ports 29B, 29C. Similarly, with regard to the cooling fans 40U, 40L, the aforementioned predetermined portion is a portion of the underside 9A of the machine chamber 9 that is outside a projected area A (predetermined region) of the cooling fans 40U, 40L projected onto the underside 9A of the machine chamber 9 when the cooling fans 40U, 40L are viewed from the opening 25 side. By arranging the corresponding exhaust ports 29C, 29D outside the projected area A, the component W2 of the cleaning air from the cooling fans 40U, 40L collides with the underside 9A, then branches off in the left and right directions in FIG. 11 and reaches the exhaust ports 29C, 29D.

[0041] In this modification, as in the above embodiment, the flow paths of component W2 of the cleaning air from cooling fans 38U, 38L, 39U, 39L, 40U, and 40L are all bent, resulting in a certain degree of pressure loss. As a result, as in the above embodiment, the airflow during cleaning is balanced evenly between the lower and upper air volumes in the vertical direction for both component W1 and component W2. As a result, as in the above embodiment, dust adhering to dustproof net 26 can be sufficiently removed and discharged during cleaning by reversely rotating cooling fans 38U, 38L, 39U, 39L, 40U, and 40L.

[0042] (2) When only some cooling fans continue to rotate in reverse and the others stop rotating in reverse. A detailed configuration near the opening 25 and the flow behavior of the cleaning air in this modified example are shown in FIG. 13, which corresponds to FIG. 11 of the modified example (1) above.

[0043] In this modification, similar to the modification (1) described above with reference to FIG. 12, multiple cooling fans (six in this example, 38U, 38L, 39U, 39L, 40U, 40L) are provided in the vertical direction corresponding to each heat exchanger 20. That is, multiple cooling fans (three in this example) are arranged in a row along a direction (predetermined direction) substantially parallel to the left side surface 24A, and the multiple cooling fans arranged in a row are arranged in multiple tiers (three in this example) in the vertical direction. Furthermore, the cooling fans 38L, 38U, the cooling fans 39L, 39U, and the cooling fans 40L, 40U are aligned in a vertical row with their positions aligned along the predetermined direction. However, unlike the modification (1), in this modification, only two cooling fans, a front exhaust port 29L and a rear exhaust port 29R, are arranged at the end of the bottom surface 9A of the machine chamber 9 on the left side surface 24A side, as shown in FIG. 13. This is because the more the number of exhaust ports 29 increases, the more noise is emitted from the machine room 9 and the strength of the bottom surface of the machine room 9 decreases. Specifically, the projected area A of cooling fans 38U and 38L, the projected area A of cooling fans 39U and 39L, and the projected area A of cooling fans 40U and 40L are aligned in the front-to-rear direction. Exhaust openings 29L and 29R are located outside these three projected areas A so as not to overlap in the vertical direction with any of these three projected areas A. Exhaust opening 29L is located further forward than the front end of the projected area A of cooling fans 38U and 38L, and exhaust opening 29R is located further rearward than the rear end of the projected area A of cooling fans 40U and 40L. In particular, in this case, cooling fans 38U, 38L, cooling fans 39U, 39L, and cooling fans 40U, 40L can be viewed as a single cooling fan group. In this case, it can also be considered that outlets 29L, 29R are disposed in positions (predetermined positions) further outward than the outermost projected areas (projected areas A of cooling fans 38U, 38L and projected areas A of cooling fans 40U, 40L) of the three projected areas A (predetermined regions) of the six cooling fans that make up the group. Alternatively, the entire cooling fan group can be considered to have a projection area Ao (predetermined area) that includes the gap area between the projection area A of cooling fan 38U, 38L and the projection area A of cooling fan 39U, 39L, and the gap area between the projection area A of cooling fan 39U, 39L and the projection area A of cooling fan 40U, 40L. In this case, exhaust ports 29L, 29R can be considered to be located in a portion (predetermined portion) outside the projection area Ao.

[0044] As described above, a component W2 (see gray arrow in Figure 13) of the cleaning air flow that does not flow out through the opening 25 but collides with the frame portion 24B of the building cover 24 and bends downward flows out from the above-mentioned exhaust ports 29L, 29R on the underside 9A of the machine room 9 to below the machine room 9. The opening area of ​​rear outlet 29R (outlet on one side) is smaller than the opening area of ​​front outlet 29L (outlet on the other side). Cooling fans 40U and 40L are arranged in a position (first position) corresponding to outlet 29R with a smaller opening area, while cooling fans 38U, 38L, 39U, and 39L are arranged in a position (second position) not corresponding to outlet 29R with a smaller opening area.

[0045] 14 , in this modification as well, the To-No correlation table, the Tr-Nr correlation table, and the Ti-Ni correlation table are referenced for the oil cooler temperature To from the oil cooler temperature sensor 30, the radiator temperature Tr from the radiator temperature sensor 31, and the intercooler temperature Ti from the intercooler temperature sensor 32, and the corresponding target rotation speeds No, Nr, and Ni of the cooling fan 21 are determined by the calculation unit 37. The determined three target rotation speeds No, Nr, and Ni are output from the controller 28 to the fan drive device 27 as final rotation speed command values. That is, the target rotation speed No is output to the fan drive device 27 of the cooling fans 38U and 38L that cool the oil cooler 17, the target rotation speed Nr is output to the fan drive device 27 of the cooling fans 39U and 39L that cool the radiator 18, and the target rotation speed Ni is output to the fan drive device 27 of the cooling fans 40U and 40L that cool the intercooler 19.

[0046] 15 as a comparative example, cleaning air component W2 blown from cooling fans 38U, 38L, 39U, 39L, 40U, 40L collide with undersurface 9A and branch off to the right in the figure, and cleaning air component W2 blown from cooling fans 39U, 39L collide with undersurface 9A and branch off to the left in the figure collide with cleaning air component W2 blown from cooling fans 39U, 39L collide with undersurface 9A and branch off to the right in the figure, and cleaning air component W2 blown from cooling fans 40U, 40L collide with undersurface 9A and branch off to the left in the figure collide with cleaning air component W2 blown from cooling fans 40U, 40L collide with undersurface 9A and branch off to the left in the figure. As a result, dust carried by the two colliding components W2, W2 accumulates on undersurface 9A near the point of collision.

[0047] Therefore, in this modified example, to avoid the above, drive control is performed by controller 28 so that only some of the six cooling fans 38U, 38L, 39U, 39L, 40U, and 40L continue to rotate in reverse and the others stop rotating in reverse. The control of cooling fans 38U, 38L, 39U, 39L, 40U, and 40L executed by controller 28 will be described with reference to the flowchart of FIG.

[0048] 16, first, in S101, as described above with reference to Fig. 14, all of the cooling fans 38U, 38L, 39U, 39L, 40U, and 40L are driven to rotate in the forward direction based on the temperatures To, Tr, and Ti detected by the corresponding temperature sensors 30, 31, and 32. This generates cooling air that takes in outside air, as described above with reference to Fig. 4, etc., and performs normal cooling of the heat exchanger 20.

[0049] Thereafter, in S102, it is determined whether or not the reverse rotation execution switch 33 provided in the driver's cab 8 has been operated. If the reverse rotation execution switch 33 has not been operated, a No determination is made and the process returns to S101 to repeat the same procedure, whereas if the reverse rotation execution switch 33 has been operated, a Yes determination is made and the process proceeds to S103.

[0050] In S103, cooling fans 38U, 38L (abbreviated as "oil cooler fans 38" in the drawing), cooling fans 39U, 39L (abbreviated as "radiator fans 39" in the drawing), and cooling fans 40U, 40L (abbreviated as "radiator fans 39" in the drawing), which are respectively aligned in the vertical direction, are all driven to rotate in reverse. As a result, a cleaning wind is generated, which includes a component W1 that flows out from the cooling fans through the opening 25 and a component W2 that collides with the frame portion 24B of the building cover 24 and bends downward, as described above with reference to FIG. 10 etc., and blows away dust adhering to the dustproof net 26.

[0051] Thereafter, in S104, it is determined whether or not the reverse rotation stop switch 34 provided in the driver's cab 8 has been operated. If the reverse rotation stop switch 34 has not been operated, a No determination is made and the process returns to S103 to repeat the same procedure, whereas if the reverse rotation stop switch 34 has been operated, a Yes determination is made and the process moves to S105.

[0052] In S105, among the cooling fans 38U, 38L, 39U, 39L, 40U, 40L whose reverse rotation drive was started in S103, the second control group consisting of cooling fans 38U, 38L, 39U, 39L (second cooling fans) is stopped, and only the first control group consisting of cooling fans 40U, 40L (first cooling fans) lined up vertically continues to be driven in reverse rotation. As a result, the blowing of cleaning air from cooling fans 38U, 38L, 39U, 39L stops, and only cleaning air is blown from cooling fans 40U, 40L.

[0053] The flow behavior of the cleaning air at this time is shown in Figure 13 mentioned above. As shown in the figure, in this state, component W2 of the cleaning air blown out from cooling fans 40U, 40L collides with underside 9A and branches to the left and right in the figure. Of these, component W2 of the cleaning air that travels to the right in the figure flows downward from rear exhaust port 29R, thereby discharging the dust that has been blown off and carried by dustproof net 26 downward in machine room 9. On the other hand, the cleaning air component W2 that has advanced to the left side in the figure flows out from the front exhaust port 29L to below the machine room 9. At that time, the cleaning air component W2 advances approximately horizontally on the underside 9A of the machine room 9 directly below the cooling fans 38U, 38L, 39U, and 39L that are not driven, and therefore the dust that has been blown off the dustproof net 26 and carried thereby can be smoothly guided to the exhaust port 29L and discharged below the machine room 9. In addition, if there is dust that has accumulated on the underside 9A near the point of impact as described above, the accumulated dust can be swept out and guided to the exhaust port 29L to be discharged below the machine room 9.

[0054] 16, after S105, in S106, it is determined whether a predetermined time (for example, several minutes) has elapsed. Until the predetermined time has elapsed, the determination is No and the process returns to S105 to repeat the same procedure, and once the predetermined time has elapsed, the determination is Yes and the process proceeds to S107.

[0055] In S107, the cooling fans 40U and 40L, which continue to rotate in the reverse direction, are stopped, thereby completely stopping the cleaning airflow.

[0056] Thereafter, in S108, similar to S101, all of the cooling fans 38U, 38L, 39U, 39L, 40U, and 40L are driven to rotate in the forward direction, thereby generating cooling air by taking in outside air, similar to the above, and normal cooling of the heat exchanger 20 is resumed.

[0057] In this modified example configured as described above, as described above with reference to FIG. 13, only some of the cooling fans (cooling fans 40U and 40L in the above example) continue to rotate in reverse, while the other cooling fans (cooling fans 38U, 38L, 39U, and 39L in the above example) are stopped. This prevents the cleaning air components W2 from cooling fans 38U and 38L, cooling fans 39U and 39L, and cooling fans 40U and 40L from interfering with or colliding with each other, and allows dust to be smoothly pushed out to the exhaust port 29. In other words, when multiple cooling fans are driven to rotate in reverse, the number of exhaust ports 29 can be reduced while preventing dust from remaining in the machine chamber 9.

[0058] In the above description, cooling fans 38U, 38L, 39U, and 39L are stopped while only cooling fan 40U and 40L are driven to rotate in reverse. However, this is not limited to this. Alternatively, only the first control group consisting of cooling fans 38U and 38L (first cooling fans) may be driven to rotate in reverse while the second control group consisting of cooling fans 39U, 39L, 40U, and 40L (second cooling fans) is stopped. Furthermore, only the first control group consisting of cooling fans 39U and 39L (first cooling fans) may be driven to rotate in reverse while the second control group consisting of cooling fans 38U, 38L, 40U, and 40L (second cooling fans) is stopped. In either case, the same effect as described above can be obtained.

[0059] In this modification, as described above with reference to FIG. 13 , the cooling fans 40U and 40L corresponding to the rear exhaust port 29R continue to rotate in the reverse direction, while the cooling fans 38U, 38L, 39U, and 39L corresponding to the front exhaust port 29L are stopped. At this time, because the opening area of ​​the rear exhaust port 29R is smaller than the opening area of ​​the front exhaust port 29L, the flow path resistance toward the rear exhaust port 29R is large and the flow path resistance toward the front exhaust port 29L is small. This makes it possible to equalize the flow of cleaning air component W2 from the cooling fans 40U and 40L toward the rear exhaust port 29R, which is closer to the fan (see the gray arrow pointing right in FIG. 13 ), and the flow toward the front exhaust port 29L, which is farther from the fan (see the gray arrow pointing left in FIG. 13 ), thereby enabling smoother and more effective dust discharge.

[0060] (3) Reverse rotation drive stop / continue control combination variations In the above-mentioned modified example (2), in order to prevent collision or interference of the cleaning air component W2 when they are driven in reverse rotation simultaneously, the cooling fans 38U, 38L (for cooling the oil cooler 17), the cooling fans 39U, 39L (for cooling the radiator 18), and the cooling fans 40U, 40L (for cooling the intercooler 19), which are respectively arranged in two rows, upper and lower, in the machine room 9, are treated as one set (one group). Then, for each group, the controller 28 divides the groups into one group for which reverse rotation driving is stopped and one group for which reverse rotation driving is continued, and performs drive control by dividing the groups into two groups.

[0061] This modified example is an extension of the previous example, and illustrates a control variation of cooling fans that may be collectively controlled as the "first control group that continues reverse rotation drive," including not only an arrangement in which the cooling fans are arranged in two rows, one above the other, but also an arrangement in which the cooling fans are not arranged in two rows. As a prerequisite for this case, a configuration in which the number of exhaust ports 29 is not sufficiently large compared to the number of "groups" of cooling fans, as shown in FIG. 11, but is small compared to the number of "groups" of cooling fans (at least two groups share one exhaust port 29), as shown in FIG. 13, will be described below with reference to FIGS. 17 to 24. In the following, FIGS. 17 to 24 illustrate an example in which multiple cooling fans are arranged in a row along a direction (predetermined direction) substantially parallel to the left side surface 24A, and the multiple cooling fans arranged in a row are arranged in multiple rows in the vertical direction.

[0062] <Examples of groups that may be controlled collectively> The examples shown in Figures 17(a), 17(b), and 17(c) are the groupings described in the aforementioned variation (2) and related examples. The cooling fans 38U and 38L, or cooling fans 39U and 39L, or cooling fans 40U and 40L, shown within the bold dashed lines, are collectively controlled as a "first control group that continues reverse rotation drive." In each case, the projected areas A of the two cooling fans in the upper and lower rows overlap vertically. As a result, even if these two cooling fans (first cooling fans) are driven simultaneously, the flow of cleaning air components W2 along the underside 9A of the machine room 9 and the left side surface 24A of the building cover 24 does not collide with each other, as described in the comparative example of Figure 15, provided that all other cooling fans (second control group consisting of second cooling fans) are stopped.

[0063] The examples shown within the thick dashed lines in Figures 18(a), 18(b), and 18(c) are cases where the bottom-most cooling fan 38L, cooling fan 39L, or cooling fan 40L in the examples shown in Figures 17(a), 17(b), and 17(c) above is controlled as "the first control group that continues to drive in reverse rotation (but is actually a single cooling fan as the first cooling fan)." Because it is driven alone, collision of the cleaning air component W2 does not occur in any case under conditions where all other cooling fans (the second control group consisting of the second cooling fan) are stopped.

[0064] 19 to 21, the cooling fans 38L, 39L, and 40L in the lower tier are the same as those in the previously described examples, but the arrangement of the cooling fans in the upper tier is different from those in the previously described examples. That is, the upper tier is provided with a cooling fan 38U for cooling the oil cooler 17, as in the previously described examples, and a cooling fan 41U shared by both the radiator 18 and the intercooler 19 (in other words, a cooling fan arranged corresponding to an adjacent heat exchanger). Since the cooling fan 41U is shared by the two heat exchangers as described above, it is arranged above the midpoint between the cooling fans 39L and 40L in the lower tier.

[0065] 17(a), the example shown in Fig. 19(a) is a case where cooling fans 38U, 38L shown in the thick dashed line frame are collectively controlled as one group, "first control group that continues reverse rotation drive." Because the projected areas A of the two upper and lower cooling fans 38U, 38L (first cooling fans) overlap each other in the vertical direction, the aforementioned collision does not occur under the condition that all other cooling fans (second control group consisting of second cooling fans) are stopped from being driven.

[0066] 19(b) shows an example in which the two lower cooling fans 39L, 40L and the upper cooling fan 41U (in other words, a specific plurality of cooling fans that are arranged to partially overlap in the vertical direction) are grouped together and controlled as a "first control group that continues reverse rotation drive," as shown in the thick dashed line frame. In this case, as shown in the figure, the projected areas A of the three cooling fans 39L, 40L, 41U (first cooling fans) partially overlap each other in the vertical direction, so that the three cooling fans 39L, 40L, 41U as a whole generally generate one large cleaning air component W2, and the above-mentioned collision does not occur under the condition that the drive of all other cooling fans (second control group consisting of second cooling fans) is stopped.

[0067] 20(a) shows an example in which one lower cooling fan 39L and one upper cooling fan 41U (in other words, a specific plurality of cooling fans that are arranged to partially overlap in the vertical direction) are grouped together and controlled as a "first control group that continues reverse rotation driving," as shown in the thick dashed line frame. As above, because the projected areas A of the two cooling fans 39L, 41U (first cooling fans) partially overlap each other in the vertical direction, the collision described above does not occur under the condition that all other cooling fans (second control group consisting of second cooling fans) are stopped from driving. 20(b) shows an example in which one cooling fan 40L on the lower row and one cooling fan 41U on the upper row (in other words, a specific plurality of cooling fans that are arranged to partially overlap in the vertical direction) are grouped together and controlled as a "first control group that continues reverse rotation driving," as shown in the thick dashed line frame. As above, because the projected areas A of the two cooling fans 40L, 41U (first cooling fans) partially overlap each other in the vertical direction, the collision described above does not occur under the condition that all other cooling fans (second control group consisting of second cooling fans) are stopped from driving.

[0068] The examples shown within the thick dashed lines in Figures 21(a), 21(b), and 21(c) are cases where the bottom-most cooling fan 38L, cooling fan 39L, or cooling fan 40L in each of the examples shown in Figures 19 and 20 is controlled as "the first control group that continues to drive in reverse rotation (but is actually a single cooling fan as the first cooling fan)." Because it is a single drive, collision of the cleaning air component W2 does not occur in any case under the condition that all other cooling fans (the second control group consisting of the second cooling fan)) are stopped.

[0069] <Examples of groups that should not be controlled collectively> Next, FIGS. 22 and 23 show an example in which cooling fans 38U, 38L, cooling fans 39U, 39L, and cooling fans 40U, 40L are arranged in two rows, upper and lower, as shown in FIG. 13 above, and they should not be controlled collectively as the "group that continues reverse rotation driving."

[0070] 22(a) shows an example in which, in the above arrangement, the lower cooling fan 39L and the upper cooling fan 40U shown in the thick dashed line frame are grouped together as a "group that continues to be driven in reverse rotation" and are controlled collectively. In this case, the projected areas A of the two upper and lower cooling fans 39L, 40U do not overlap at all in the vertical direction. 22(b) shows an example in which, in the same arrangement as above, the lower cooling fan 38L and the upper cooling fan 39U shown in the thick dashed line frame are grouped together as a "group that continues to be driven in reverse rotation" and are to be controlled collectively. In this case as well, as above, the projected areas A of the two upper and lower cooling fans 38L, 39U do not overlap at all in the vertical direction. 22(c) shows an example in which, in the same arrangement as above, the lower cooling fan 38L and the upper cooling fan 40U shown in the thick dashed line frame are grouped together and controlled as a "group that continues to be driven in reverse rotation." In this case, as in the above, the projected areas A of the two upper and lower cooling fans 38L, 40U do not overlap at all in the vertical direction.

[0071] 23(a) shows an example in which, in the above arrangement, the lower cooling fan 40L and the upper cooling fan 38U shown in the thick dashed line frame are grouped together and controlled as a "group that continues to be driven in reverse rotation." In this case as well, the projected areas A of the two upper and lower cooling fans 40L, 38U do not overlap at all in the vertical direction. 23(b) shows an example in which, in the same arrangement as above, the lower cooling fan 39L and the upper cooling fan 38U shown in the thick dashed line frame are grouped together as a "group that continues to be driven in reverse rotation" and are to be controlled collectively. In this case as well, as above, the projected areas A of the two upper and lower cooling fans 39L, 38U do not overlap at all in the vertical direction. 23(c) shows an example in which, in the same arrangement as above, the lower cooling fan 40L and the upper cooling fan 38U shown in the thick dashed line frame are grouped together and controlled as a "group that continues to be driven in reverse rotation." In this case, as in the above, the projected areas A of the two upper and lower cooling fans 40L, 38U do not overlap at all in the vertical direction.

[0072] 22(a) to 22(c) and 23(a) to 23(c) above, if the two cooling fans within the bold dashed lines are driven to rotate in reverse simultaneously, the flows of the cleaning air component W2 along the underside 9A of the machine room 9 and the left side surface 24A of the building cover 24 may collide with each other, as explained in the comparative example of Fig. 15. Therefore, at least the two cooling fans within the bold dashed lines must be divided into separate groups and controlled for drive.

[0073] Furthermore, Figures 24(a) to (c) show an example in which the cooling fan 41U is positioned above the intermediate position between the lower cooling fans 39L and 40L as shown in Figures 19 to 21 above, and the cooling fans 41U and 40L should not be controlled collectively as the "group that continues reverse rotation driving."

[0074] 24(a) shows an example in which, in the above arrangement, the lower cooling fan 39L and the upper cooling fan 38U shown in the thick dashed line frame are grouped together and controlled as a "group that continues to be driven in reverse rotation." In this case as well, the projected areas A of the two upper and lower cooling fans 39L, 38U do not overlap at all in the vertical direction. 24(b) shows an example in which, in the same arrangement as above, the lower cooling fan 38L and the upper cooling fan 41U shown in the thick dashed line frame are grouped together and controlled as a "group that continues to be driven in reverse rotation." In this case, as in the above, the projected areas A of the two upper and lower cooling fans 38L, 41U do not overlap at all in the vertical direction. 24(c) shows an example in which, in the same arrangement as above, the lower cooling fan 40L and the upper cooling fan 38U shown in the thick dashed line frame are grouped together as a "group that continues to be driven in reverse rotation" and are to be controlled collectively. In this case, as in the above, the projected areas A of the two upper and lower cooling fans 40L, 38U do not overlap at all in the vertical direction.

[0075] 24(a) to 24(c), if the two cooling fans within the bold dashed lines are driven to rotate in reverse simultaneously, the flows of the cleaning airflow components W2 along the underside 9A of the machine room 9 and the left side surface 24A of the building cover 24 may collide with each other, as explained in the comparative example of Fig. 15. Therefore, at least the two cooling fans within the bold dashed lines must be divided into separate groups and controlled for drive.

[0076] As discussed above for each example, when attempting to perform reverse rotation driving in a configuration in which multiple cooling fans are arranged, for example, as shown in Figures 23(a) to (c) and 24(a) to (c), in the case of cooling fans arranged so that they are separated into one side and the other along the left side surface 24A of the building cover, there is a risk that the components W2 of those cooling fans will collide or interfere with each other, as mentioned above, and effective dust discharge will not be possible. 17(a)-(c), 19(a), (b), and 20(a), (b), for example, by driving the cooling fans in the reverse direction only when the projected areas A of the cooling fans are overlapped when viewed from the opening 25 side, the components W2 from the cooling fans can be made to combine to form a single component W2. As a result, collisions and interference between the cleaning air components W2 from the cooling fans can be prevented, and dust can be effectively and reliably discharged.

[0077] (4) Other Although the above description has been given using a crawler hydraulic excavator 1 as an example of construction machinery, the application of the present invention is not limited to this. For example, the present invention can be widely applied to other construction machinery, such as hydraulic cranes and wheel loaders, in which the rotation speed of the cooling fan can be determined regardless of the rotation speed of the engine.

[0078] In addition to the above, the methods according to the above embodiments and modifications may be used in appropriate combination. Although not specifically illustrated, the present invention can be implemented with various modifications within the scope of the invention.

[0079] Furthermore, the problems to be solved by the invention and the effects of the invention are not limited to those described above. That is, the present invention may solve problems or achieve effects not described above, or may solve only some of the problems or achieve only some of the effects described. [Explanation of symbols]

[0080] 1. Hydraulic excavator (construction machinery) 9 Machine room 9A Bottom 9B Closing surface 17 Oil cooler 18 Radiator 19 Intercooler 20 Heat exchanger 21 Cooling fan 24 Building cover 24A Left side (side) 24B frame part 25 Opening 26 Dustproof net 28 Controller 29 Discharge port (dust discharge port) 29A, 29B Discharge port (dust discharge port) 29B, 29C Discharge port (dust discharge port) 29L outlet (dust outlet) 29R Discharge port (dust discharge port) 38L cooling fan 38U Cooling Fan 39L cooling fan 39U Cooling Fan 40L cooling fan 40U Cooling Fan 41U Cooling Fan A Projected area Ao Projected area W1 Cleaning Wind Ingredients W2 Cleaning Wind Ingredients

Claims

1. The machine room and a building cover that covers the machine room; a cooling fan disposed in the machine room; a heat exchanger disposed in the machine room and between the building cover and the cooling fan; a control device that can selectively switch the cooling fan between forward rotation and reverse rotation; In a construction machine equipped with an opening provided on a side surface of the building cover; a dustproof net provided between the side surface of the building cover and the heat exchanger; a dust exhaust port provided at a predetermined portion of the underside of the machine room, the dust exhaust port being located between the side surface of the building cover and the dustproof net and outside a predetermined region below the cooling fan; A construction machine characterized by having:

2. 2. The construction machine according to claim 1, The lower surface located between the side surface of the building cover and the dustproof net has a closed surface with no openings other than the dust outlet. Construction machinery characterized by:

3. 3. The construction machine according to claim 2, The dust outlet is The predetermined area is sandwiched between the two adjacent areas. Construction machinery characterized by:

4. 4. The construction machine according to claim 3, a plurality of the heat exchangers are provided in parallel with respect to the flow of cooling air generated by the cooling fan; a plurality of cooling fans are provided in a vertical direction corresponding to each of the plurality of heat exchangers; The control device A plurality of first cooling fans included in a specific row of a plurality of rows of cooling fans aligned in a vertical direction are grouped as a first control group, and a plurality of other second cooling fans are grouped as a second control group, and after all the cooling fans are rotated in reverse, only the first control group continues to rotate in reverse while the second control group stops rotating. Construction machinery characterized by:

5. 5. The construction machine according to claim 4, The opening area of ​​the dust discharge port on one side is formed smaller than the opening area of ​​the dust discharge port on the other side, The plurality of first cooling fans of the first control group are The dust discharge port is disposed in a first portion corresponding to the dust discharge port on the one side, The plurality of second cooling fans of the second control group are The dust discharge port is disposed in a second portion not corresponding to the dust discharge port on the one side. Construction machinery characterized by:

6. 4. The construction machine according to claim 3, a plurality of the heat exchangers are arranged in parallel with the flow of cooling air generated by the cooling fan; a plurality of the cooling fans are arranged in the vertical direction, some of the plurality of cooling fans are arranged corresponding to each of the heat exchangers, and the remaining cooling fans are arranged corresponding to adjacent heat exchangers; The control device A specific plurality of first cooling fans that are arranged to overlap each other in the vertical direction are grouped as a first control group, and the other plurality of second cooling fans are grouped as a second control group. After all of the cooling fans are rotated in reverse, only the first control group continues to rotate in reverse while the second control group stops rotating. Construction machinery characterized by:

7. 4. The construction machine according to claim 3, a plurality of the heat exchangers are provided in parallel with respect to the flow of cooling air generated by the cooling fan; a plurality of cooling fans are provided in the vertical direction corresponding to each of the heat exchangers or to adjacent heat exchangers; The control device A specific one of the first cooling fans included in the plurality of cooling fans arranged in the bottom row is grouped as a first control group, and the other plurality of second cooling fans are grouped as a second control group, and after all of the cooling fans are rotated in reverse, only the first control group continues to rotate in reverse while the second control group stops rotating. Construction machinery characterized by:

8. 2. The construction machine according to claim 1, A construction machine characterized in that the specified area is the area of ​​the underside of the machinery room where the cooling fan is projected onto the underside of the machinery room when the cooling fan is viewed from the opening side.

Images