JP2021194933A - Construction machine - Google Patents

Abstract

To provide a construction machine capable of improving cleaning workability of heat exchangers.SOLUTION: A construction machine includes: first and second ventilation flues 41, 42 arranged in parallel to each other; first and second heat exchangers 43, 44 disposed in the first and second ventilation flues respectively; first cooling fans 45, 46 and second cooling fans 47, 48 for cooling the first and second heat exchangers respectively; a barrier part 31 disposed at an interval from second openings 41b, 42b of both ventilation flues; and a controller 70 for controlling the drive of the first and second cooling fans. The first and second cooling fans are capable of switching between normal rotation and reverse rotation, and they generate an air stream for which first openings 41a, 42a are inflow ports and the second openings are outflow ports during normal rotation. Under prescribed conditions, the controller switches a first operation of driving the first and second cooling fans in normal rotation to a second operation of driving the first cooling fan in reverse rotation and the second cooling fan in normal rotation.SELECTED DRAWING: Figure 9

Description

The present invention relates to a construction machine, and more particularly to a construction machine that supplies cooling air to a plurality of heat exchangers such as a radiator and an oil cooler by a plurality of cooling fans.

In construction machinery such as hydraulic excavators, hydraulic cranes, and wheel loaders, an engine, a hydraulic pump, a plurality of heat exchangers, and the like are housed in an engine room. In addition, a cooling fan is installed in the engine room to cool those devices. The cooling fan takes in outside air into the engine room and supplies it as cooling air. Multiple cooling fans may be installed to accommodate multiple heat exchangers.

By the way, construction machinery may operate in a harsh environment with a lot of dust. A hydraulic excavator, which is one of construction machines, is not only used for excavating earth and sand, but may also perform various operations at work sites in various environments such as inside a building or inside a waste carrier. For example, at a work site inside a building, metal scrap is dismantled, sorted, and moved. At the work site on board, wood chips and coal are scraped and transported. At such a work site, various small things become dust and scatter in the air.

When the construction machine operates in such an environment, the outside air taken into the engine room by the drive of the cooling fan contains dust. Therefore, when the outside air as the cooling air passes through the heat exchanger, the dust taken into the engine room together with the outside air adheres to the surface of the heat exchanger. If the heat exchanger is clogged with the continuous adhesion of dust, the amount of cooling air passing through the heat exchanger is limited, and the cooling performance of the heat exchanger is deteriorated. As a result, the engine and hydraulic system may overheat.

Therefore, in some construction machines that operate in an environment where dust is scattered, a cooling fan that generates cooling air by driving in the forward rotation is driven in the reverse rotation, so that the air flow for cleaning is in the opposite direction to the cooling air. Is supplied to the heat exchanger, and the dust adhering to the heat exchanger is blown off and removed by the cleaning air flow (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2008-126843

In the cooling device of the work machine described in Patent Document 1, when the heat exchanger is cleaned, the cooling fan located on the heat exchanger side to be cleaned is reversely controlled among the two cooling fans, but the cooling fan is not to be cleaned. The cooling fan located on the heat exchanger side is temporarily stopped. However, there is a limit to the air volume and static pressure that can be generated by one cooling fan for the heat exchanger to be cleaned. If the air volume and static pressure for cleaning the heat exchanger can be increased from the current level, the cleaning workability of the heat exchanger can be further improved. That is, it is considered that there is room for improvement in the efficiency of cleaning workability of the heat exchanger with respect to the cooling device of the working device described in Patent Document 1.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a construction machine capable of improving the cleaning workability of a heat exchanger.

The present application includes a plurality of means for solving the above problems, one of which is formed by being surrounded by a wall portion extending in one direction and having a first opening and a second opening, respectively. The first and second ventilation passages arranged in parallel with each other, the first heat exchanger arranged inside the first ventilation passage, and the inside of the second ventilation passage are arranged. A second heat exchanger, a first cooling fan arranged inside the first air passage, and a first cooling fan for cooling the first heat exchanger, and an arrangement inside the second air passage. Then, a gap is opened between the second cooling fan for cooling the second heat exchanger and the second opening of the first ventilation path in the extending direction of the first ventilation path. A barrier portion arranged with a gap in the extending direction of the second ventilation passage with respect to the second opening of the second ventilation passage, the first cooling fan, and the said. The first cooling fan and the second cooling fan are provided with a controller for controlling the drive of the second cooling fan, and the first cooling fan and the second cooling fan can be switched between forward rotation and reverse rotation, and the first opening during normal rotation. Generates an air flow in which the second opening serves as an inflow port and the second opening serves as an outflow port, and the space between the first ventilation path and the barrier portion, the second ventilation path, and the barrier portion. The controller communicates with the space between them, and when a predetermined condition is satisfied, the controller performs the first operation of driving the first cooling fan and the second cooling fan in a forward rotation. It is characterized in that the cooling fan is driven in the reverse rotation and the second operation is switched to the second operation in which the second cooling fan is driven in the forward rotation.

According to the present invention, a part of the air flow discharged from the second cooling fan that rotates in the forward direction by driving the first cooling fan in the reverse rotation while driving the second cooling fan in the forward rotation. Flows to the suction side of the first cooling fan that rotates in the reverse direction, so that the arrangement relationship between the first cooling fan that rotates in the reverse direction and the second cooling fan that rotates in the forward direction is similar to the arrangement in series. Therefore, it is possible to increase the air volume and static pressure of the air flow flowing through the first heat exchanger as compared with the case where the second cooling fan is stopped. As a result, the dust adhering to the first heat exchanger can be efficiently removed, and the cleaning workability of the first heat exchanger is improved.
Issues, configurations and effects other than the above will be clarified by the following description of the embodiments.

It is a side view which shows the hydraulic excavator to which the 1st Embodiment of the construction machine of this invention is applied. It is a perspective view which shows the upper swing body of the hydraulic excavator shown in FIG. FIG. 2 is a schematic cross-sectional view of the machine room of the upper swing body of the hydraulic excavator shown in FIG. 2 as viewed from the arrow III-III. FIG. 3 is a schematic cross-sectional view of the machine room of the hydraulic excavator shown in FIG. 3 as viewed from the IV-IV arrow. It is a block diagram which shows the hardware composition and the functional composition of the controller which constitutes a part of the 1st Embodiment of the construction machine of this invention. FIG. 5 is a flowchart showing an example of a control procedure for normal operation and cleaning operation of a cooling fan during operation of a construction machine by a controller constituting a part of the first embodiment of the construction machine shown in FIG. FIG. 5 is a flowchart showing an example of a control procedure for cleaning operation of a cooling fan at the end of operation of the construction machine by a controller constituting a part of the first embodiment of the construction machine of the present invention shown in FIG. It is explanatory drawing which shows the flow of the cooling air at the time of execution of the normal operation of the cooling fan in 1st Embodiment of the construction machine of this invention. It is explanatory drawing which shows the flow of the air flow at the time of execution of the cleaning operation which made the 1st heat exchanger a cleaning target in 1st Embodiment of the construction machine of this invention. It is explanatory drawing which shows the flow of the air flow at the time of execution of the cleaning operation for cleaning the 2nd heat exchanger in the 1st Embodiment of the construction machine of this invention. It is a block diagram which shows the hardware composition and the functional composition of the controller which constitutes a part of the 2nd Embodiment of the construction machine of this invention. FIG. 11 is a flowchart showing an example of a control procedure for normal operation and cleaning operation of a cooling fan during operation of a construction machine by a controller constituting a part of a second embodiment of the construction machine of the present invention shown in FIG. FIG. 11 is a flowchart showing an example of a control procedure for cleaning operation of a cooling fan at the end of operation of the construction machine by a controller constituting a part of the second embodiment of the construction machine of the present invention shown in FIG.

Hereinafter, embodiments of the construction machine of the present invention will be described with reference to the drawings. In the present embodiment, a hydraulic excavator will be described as an example of a construction machine. In the following, the front-back and left-right directions will be described with reference to the operator seated in the driver's seat.

[First Embodiment]
First, the configuration of the hydraulic excavator to which the first embodiment of the construction machine of the present invention is applied will be described with reference to FIGS. 1 to 3. FIG. 1 is a side view showing a hydraulic excavator to which the first embodiment of the construction machine of the present invention is applied. FIG. 2 is a perspective view showing an upper swing body of the hydraulic excavator shown in FIG. FIG. 3 is a schematic cross-sectional view of the machine room of the upper swing body of the hydraulic excavator shown in FIG. 2 as viewed from the arrow III-III. The left-right direction in FIG. 1 is the front-rear direction of the hydraulic excavator.

In FIG. 1, the hydraulic excavator 1 is provided on a self-propelled lower traveling body 2, an upper turning body 3 mounted on the lower traveling body 2 so as to be able to turn, and a bobbin on the front portion of the upper turning body 3 so as to be able to move up and down. It is roughly composed of the work front 4 and the work front 4. The lower traveling body 2 is provided with a crawler type traveling device 6 (only one of them is shown) on the left and right sides. The left and right traveling devices 6 are each driven by a traveling motor (not shown) as a hydraulic actuator. The upper swivel body 3 is swiveled relative to the lower traveling body 2 by a swivel motor (not shown) as a hydraulic actuator. The work front 4 is an articulated actuating device for performing excavation work and the like, and includes a boom 7, an arm 8, and a bucket 9 as a work tool. The base end side of the boom 7 is rotatably connected to the front portion of the upper swivel body 3. A base end portion of the arm 8 is rotatably connected to the tip end portion of the boom 7. The base end portion of the bucket 9 is rotatably connected to the tip end portion of the arm 8. The boom 7, arm 8, and bucket 9 are driven by a boom cylinder 7a, an arm cylinder 8a, and a bucket cylinder 9a as hydraulic actuators, respectively.

As shown in FIGS. 1 and 2, the upper swivel body 3 has a swivel frame 11 as a support structure mounted on the lower traveling body 2 so as to be swivel, and a cab installed on the left front side on the swivel frame 11. 12, a fuel tank 13 and a hydraulic oil tank 14 arranged on the right side of the swivel frame 11, a counterweight 15 provided at the rear end of the swivel frame 11, and a counterweight 15 provided between the cab 12 and the counterweight 15. It is configured to include the machine room 20 provided. The cab 12 includes a driver's seat on which an operator sits, various operating devices for operating the lower traveling body 2, the work front 4, and the like (both not shown), and a key switch 12a (see FIGS. 4 and 5) described later. Etc. are arranged. The counterweight 15 is for balancing the weight with the work front 4.

As shown in FIG. 3, the machine room 20 houses the engine 31 as a prime mover. The engine 31 is arranged in a substantially central portion in the machine room 20 in a horizontally placed state in which the output shaft extends in the left-right direction. A hydraulic pump 32 is connected to the engine 31 via a power transmission device 33. The hydraulic pump 32 is arranged, for example, on one side (right side in FIG. 3) of the engine 31 in the axial direction. The hydraulic pump 32 is driven by the engine 31 to suck in the hydraulic oil in the hydraulic oil tank 14 (see FIG. 2), and the cylinders 7a, 8a, 9a (see FIG. 1) of the work front 4 and the lower traveling body. It supplies hydraulic oil to hydraulic actuators such as the traveling motor and the swivel motor (both not shown) of 2.

In the machine room 20, a cooling device 40 is arranged on the opposite side (left side in FIG. 3) of the hydraulic pump 32 with the engine 31 interposed therebetween. The cooling device 40 discharges heat generated by driving a hydraulic system including a hydraulic pump 32, hydraulic actuators 7a, 8a, 9a, etc., heat generated by driving an engine 31, and the like to the outside of the hydraulic excavator 1. The detailed configuration of the cooling device 40 will be described later.

The outer shell of the machine room 20 is formed by a cover 21 that surrounds various devices such as an engine 31, a hydraulic pump 32, and a cooling device 40. As shown in FIGS. 2 and 3, the cover 21 is erected on the lower cover 22, the left side cover 23 erected on the left end side of the lower cover 22, and the right end side of the lower cover 22. The right side cover 24 and the front side cover 25 which is erected on the front end side of the lower cover 22 and extends over the front end portion of the left side cover 23 and the front end portion of the right side cover 24, and the lower side. The rear side cover 26 which is erected on the rear end side of the cover 22 and extends over the rear end portion of the left side cover 23 and the rear end portion of the right side cover 24, and the left and right side covers 23 and 24. , The front cover 25 and the upper cover 27 covering the upper opening formed by the rear cover 26. The left side cover 23 faces the cooling device 40, and the right side cover 24 faces the hydraulic pump 32. The left side cover 23 is provided with a suction port 23a for taking in outside air in the machine room 20. The upper cover 27 is provided with a plurality of exhaust portions 27a (two in FIG. 2) in the left-right direction of the upper swivel body 3. The exhaust unit 27a is for discharging the cooling air generated by the cooling fans 45, 46, 47, 48, which will be described later, constituting the cooling device 40, to the outside of the machine room 20. The upper cover 27 is provided with an exhaust pipe 23b for discharging the exhaust gas of the engine 31 so as to project upward.

Next, the configuration of the cooling device according to the first embodiment of the construction machine of the present invention will be described with reference to FIGS. 3 and 4. FIG. 4 is a schematic cross-sectional view of the machine room of the hydraulic excavator shown in FIG. 3 as viewed from the IV-IV arrow.

In the machine room 20, a first ventilation passage 41 and a second ventilation passage 42 extending in one direction (horizontal direction in FIG. 3 and orthogonal direction on the paper surface in FIG. 4) are formed so as to be parallel to each other. There is. Specifically, a part of the internal space of the machine room 20 is divided by a partition wall 29 extending in one direction, and the partition wall 29 extends from the left side cover 23 to a position where a gap is provided with respect to the engine 31. ing. The first ventilation passage 41 is formed by the lower cover 22, the front cover 25, the upper cover 27 as the wall portion constituting the cover 21 of the machine room 20, and the partition wall 29 as the wall portion. The second ventilation passage 42 is formed by the lower cover 22, the rear cover 26, the upper cover 27, and the partition wall 29 as the wall portion constituting the cover 21. That is, the first ventilation passage 41 and the second ventilation passage 42 extend in the left-right direction of the upper swivel body 3 (see FIGS. 1 and 2) and are arranged side by side in the front-rear direction of the upper swivel body 3. It is formed. The first ventilation passage 41 and the second ventilation passage 42 have the first openings 41a and 42a on one side (left side in FIG. 3) and the other side (right side in FIG. 3), respectively. It has second openings 41b and 42b. The first openings 41a and 42a serve as inlets for the air flow generated by the cooling fans 45, 46, 47 and 48 described later during normal rotation, and the second openings 41b and 42b are the cooling fans 45, 46, 47, described later. 48 serves as an outlet for the air flow generated during normal rotation.

The engine 31 is arranged with a gap in the extending direction of the first and second ventilation passages 41 and 42 with respect to the second openings 41b and 42b of the first and second ventilation passages 41 and 42. .. The wall surface of the engine 31 forms a communication passage 35 connected to the second opening 41b of the first ventilation passage 41 and the second opening 42b of the second ventilation passage 42. That is, the space between the first ventilation passage 41 and the engine 31 and the space between the second ventilation passage 42 and the engine 31 communicate with each other. The engine 31 allows the air flow flowing out from the second opening 41b of the first ventilation passage 41 or the second opening 42b of the second ventilation passage 42 to flow to the second of the second ventilation passage 42 on the adjacent other side. It functions as a barrier portion for turning to the second opening 41b side of the opening 42b or the first ventilation passage 41.

The cooling device 40 includes a first heat exchanger 43 and a second heat exchanger 44, one of which is respectively arranged inside the first ventilation passage 41 and one of the second ventilation passages 42, and a first. Cooling fan 45 and cooling fan 46 arranged in the first ventilation passage 41 so as to face one side (right side in FIG. 3) of the heat exchanger 43, and one side of the second heat exchanger 44. It includes a cooling fan 47 and a cooling fan 48 arranged in the second ventilation passage 42 so as to face (on the right side in FIG. 3).

The first heat exchanger 43 is, for example, a radiator that cools a cooling medium (cooling water) for cooling the heat generated in the engine 31. The second heat exchanger 44 circulates a hydraulic system including, for example, a hydraulic pump 32, cylinders 7a, 8a, 9a of the work front 4 (see FIG. 1), a traveling motor, and a swivel motor (both not shown). An oil cooler that cools hydraulic oil.

The two cooling fans, the cooling fan 45 and the cooling fan 46, constitute a first cooling fan for cooling the first heat exchanger 43, for example, in the shape of the first heat exchanger 43. They are arranged side by side in the vertical direction accordingly. One cooling fan 45 of the first cooling fan is arranged corresponding to the first region above the first heat exchanger 43, and the other cooling fan 46 of the first cooling fan is the first heat exchanger. It is arranged corresponding to the second region on the lower side of 43. The two cooling fans, the cooling fan 47 and the cooling fan 48, constitute a second cooling fan for cooling the second heat exchanger 44, for example, in the shape of the second heat exchanger 44. They are arranged side by side in the vertical direction accordingly. One cooling fan 47 of the second cooling fan is arranged corresponding to the first region above the second heat exchanger 44, and the other cooling fan 48 of the second cooling fan is the second heat exchanger. It is arranged corresponding to the second region below the 44.

Each of the cooling fans 45, 46, 47, 48 has, for example, a rotary shaft portion 51 and a plurality of (four in FIG. 4) wing portions 52 arranged in the circumferential direction with respect to the outer peripheral portion of the rotary shaft portion 51. have. Each of the cooling fans 45, 46, 47, 48 is rotationally driven by an electric motor 53 as a drive device connected to the rotary shaft portion 51, and rotates in a forward rotation in a certain direction and in the opposite direction to the forward rotation. It is possible to switch between reverse rotation and reverse rotation. Each of the cooling fans 45, 46, 47, 48 has a second opening 41b from the first opening 41a, 42a side (left side in FIG. 3) of the first or second ventilation passage 41, 42 during normal rotation. It is configured to generate an air flow flowing toward the 42b side (right side in FIG. 3). The cooling fan 45 and the cooling fan 46 (first cooling fan) take outside air into the first ventilation passage 41 and supply it to the first heat exchanger 43 as cooling air. The cooling fan 47 and the cooling fan 48 (second cooling fan) take outside air into the second ventilation passage 42 and supply it to the second heat exchanger 44 as cooling air.

As shown in FIG. 4, a first temperature sensor 61 and a second temperature sensor 62 are arranged in the first heat exchanger 43. The first temperature sensor 61 detects the temperature in the first region (the region where one of the cooling fans 45 of the first cooling fan faces) on the upper side of the first heat exchanger 43. The second temperature sensor 62 detects the temperature in the second region (the region facing the other cooling fan 46 of the first cooling fan) below the first heat exchanger 43. A third temperature sensor 63 and a fourth temperature sensor 64 are arranged in the second heat exchanger 44. The third temperature sensor 63 detects the temperature of the first region (the region facing one of the cooling fans 47 of the second cooling fan) on the upper side of the second heat exchanger 44. The fourth temperature sensor 64 detects the temperature in the second region (the region of the second cooling fan facing the other cooling fan 48) below the second heat exchanger 44. The temperature detected by each of the temperature sensors 61, 62, 63, 64 is, for example, the surface temperature of the core in each region of each heat exchanger 43, 44 or the ambient temperature around each region of each heat exchanger 43, 44. be. Each of the temperature sensors 61, 62, 63, 64 is electrically connected to the controller 70, and outputs a detection signal corresponding to the detected temperature (detection value) to the controller 70.

A key switch 12a for instructing the start and stop of the hydraulic excavator 1 (see FIG. 1) is electrically connected to the controller 70. The key switch 12a outputs an on signal (starting instruction signal) instructing the start of the hydraulic excavator 1 or an off signal (operation stop instruction signal) instructing the operation stop of the hydraulic excavator 1 to the controller 70.

The controller 70 is electrically connected to an electric motor 53 as a driving device for each of the cooling fans 45, 46, 47, 48, and each cooling fan 45, 46, 47, 48 is electrically connected to the electric motor 53 via control over the electric motor 53. It controls the drive of. The controller 70 cleans the normal operation (first operation) of the cooling fan for cooling the first heat exchanger 43 and the second heat exchanger 44, the first heat exchanger 43, or the second heat exchanger 44. The drive of each cooling fan 45, 46, 47, 48 is controlled according to the cleaning operation (second operation or third operation of the cooling fan).

Next, the hardware configuration and the functional configuration of the controller constituting a part of the first embodiment of the construction machine of the present invention will be described with reference to FIG. FIG. 5 is a block diagram showing a hardware configuration and a functional configuration of a controller constituting a part of the first embodiment of the construction machine of the present invention.

In FIG. 5, the controller 70 includes a storage device 71 composed of a ROM, a RAM, or the like, and a processing device 72 composed of a CPU, an MPU, or the like, as a hardware configuration. The storage device 71 stores in advance programs and various information necessary for executing normal operation and cleaning operation. The processing device 72 realizes various functions by appropriately reading a predetermined program and various information from the storage device 71 and executing processing according to the program.

The controller 70 includes, for example, a storage unit 81 as a function of the storage device 71, an operation switching determination unit 82 and a fan control unit 83 as functions executed by the processing device 72.

The storage unit 81 stores in advance a first threshold value S1, a second threshold value S2, a third threshold value S3, and a fourth threshold value S4 used for the determination of the operation switching determination unit 82. The first to fourth thresholds S1, S2, S3, and S4 are comparison targets of the detection values T1, T2, T3, and T4 output from the first to fourth temperature sensors 61, 62, 63, and 64, respectively. .. The first to second threshold values S1 and S2 are values that the first heat exchanger 43 is considered to be in an abnormal state due to an excessive temperature rise. The third to fourth threshold values S3 and S4 are values that consider the second heat exchanger 44 to be in an abnormal state due to an excessive temperature rise.

The operation switching determination unit 82 either executes a normal operation (first operation) for cooling the first and second heat exchangers 43 and 44, or either the first and second heat exchangers 43 and 44. It is for determining whether to execute the cleaning operation (second operation or third operation). Specifically, the operation switching determination unit 82 determines to execute the cleaning operation (second operation and third operation) when the off signal (operation stop instruction signal) of the key switch 12a is input. Further, the operation switching determination unit 82 stores the detection values T1, T2, T3, and T4 from the first to fourth temperature sensors 61, 62, 63, and 64 in the storage unit 81 in advance. By comparing with the threshold values S1, S2, S3, and S4 of 4, it is determined to execute either the normal operation or the cleaning operation.

The fan control unit 83 drives each cooling fan 45, 46, 47, 48 in a forward rotation according to a normal operation (first operation) or a cleaning operation (second operation or a third operation), or a forward rotation command or a reverse rotation command. A reverse rotation command to be driven by rotation is output to the electric motor 53 as a drive device for each of the cooling fans 45, 46, 47, 48. In normal operation, the fan control unit 83 determines, for example, the rotation speeds of the cooling fans 45, 46, 47, and 48 by detecting values T1, T2, and T3 of the first to fourth temperature sensors 61, 62, 63, and 64, respectively. , It is possible to control to change according to T4. Further, in the cleaning operation, for example, it is possible to temporarily control the rotation speed of each of the cooling fans 45, 46, 47, 48 to be constant.

Next, the control procedure of the normal operation and the cleaning operation of the cooling fan by the controller constituting a part of the first embodiment of the construction machine of the present invention will be described with reference to FIGS. 5 to 7. FIG. 6 is a flowchart showing an example of a control procedure for normal operation and cleaning operation of a cooling fan during operation of a construction machine by a controller constituting a part of the first embodiment of the construction machine of the present invention shown in FIG. be. FIG. 7 is a flowchart showing an example of a control procedure for cleaning operation of the cooling fan at the end of operation of the construction machine by the controller constituting a part of the first embodiment of the construction machine of the present invention shown in FIG.

First, as shown in FIG. 6, the controller 70 is in normal operation (first cooling fan) for cooling the first and second heat exchangers 43 and 44 while the hydraulic excavator 1 (see FIG. 1) is in operation. Operation) is executed, and when it is determined that an abnormality has occurred in any of the first and second heat exchangers 43 and 44 during the execution of the normal operation, the heat exchanger determined to have an abnormality is targeted for cleaning. Switch to the cleaning operation (second operation or third operation of the cooling fan).

Specifically, when the ON signal (starting instruction signal) of the key switch 12a shown in FIG. 5 is input, the controller 70 starts controlling each of the cooling fans 45, 46, 47, 48 (shown in FIG. 6). Start of flowchart). First, the operation switching determination unit 82 of the controller 70 determines that normal operation (first operation of the cooling fan) is executed, and the fan control unit 83 of the controller 70 determines that the electric motor corresponding to each of the cooling fans 45, 46, 47, 48. A forward rotation command for driving the 53 in a forward rotation is output (step S10 shown in FIG. 6).

Next, the operation switching determination unit 82 determines whether or not a temperature abnormality has occurred in the first heat exchanger 43 (step S20 shown in FIG. 6). Specifically, the operation switching determination unit 82 compares the detection value T1 from the first temperature sensor 61 with the first threshold value S1 stored in advance in the storage unit 81, and also from the second temperature sensor 62. The detected value T2 of the above is compared with the second threshold value S2 stored in advance in the storage unit 81. When the detected value T1 is larger than the first threshold value S1 or the detected value T2 is larger than the second threshold value S2, the temperature abnormality has occurred in the first heat exchanger 43 (YES). judge. In other cases, that is, when the detected value T1 is equal to or less than the first threshold value S1 and the detected value T2 is equal to or less than the second threshold value S2, the first heat exchanger 43 is normal (NO). ).

If it is determined in step S20 that YES (the first heat exchanger 43 has an abnormal temperature), the controller 70 performs a cleaning operation (second operation of the cooling fan) for the first heat exchanger 43 as a cleaning target. Execute (step S30 shown in FIG. 6). Specifically, the fan control unit 83 outputs a reverse rotation command for driving the cooling fan 45 and the electric motor 53 corresponding to the cooling fan 46 (first cooling fan) in reverse rotation for a predetermined time, and outputs the reverse rotation command. A forward rotation command is output to the electric motor 53 corresponding to the cooling fan 47 and the cooling fan 48 (second cooling fan) for a predetermined time, respectively. As a result, the cooling fan 45 and the cooling fan 46 (first cooling fan) located on the first heat exchanger 43 side are driven in reverse rotation, and the cooling fan 47 and the cooling fan located on the second heat exchanger 44 side are driven in reverse. The forward rotation drive of 48 (second cooling fan) is continued for a predetermined time at the same time.

On the other hand, when it is determined as NO (the first heat exchanger 43 is normal) in step S20, the controller 70 determines whether or not a temperature abnormality has occurred in the second heat exchanger 44 (FIG. 6). Step S40 shown in. Specifically, the operation switching determination unit 82 compares the detection value T3 from the third temperature sensor 63 with the third threshold value S3 stored in advance in the storage unit 81, and also from the fourth temperature sensor 64. The detected value T4 of the above is compared with the fourth threshold value S4 stored in advance in the storage unit 81. When the detected value T3 is larger than the third threshold value S3, or when the detected value T4 is larger than the fourth threshold value S4, the temperature abnormality has occurred in the second heat exchanger 44 (YES). judge. In other cases, that is, when the detected value T3 is equal to or less than the third threshold value S3 and the detected value T4 is equal to or less than the fourth threshold value S4, the second heat exchanger 44 is normal (NO). ).

If YES (the second heat exchanger 44 has an abnormal temperature) is determined in step S40, the controller 70 performs a cleaning operation (third operation of the cooling fan) for the second heat exchanger 44 as a cleaning target. Execute (step S50 shown in FIG. 6). Specifically, the fan control unit 83 outputs a forward rotation command to the cooling fan 45 and the electric motor 53 corresponding to the cooling fan 46 (first cooling fan) for a predetermined time, and also outputs the cooling fan 47 and cooling. A reverse rotation command is output to the electric motor 53 corresponding to the fan 48 (second cooling fan) for a predetermined time. As a result, the cooling fan 45 and the cooling fan 46 (first cooling fan) located on the first heat exchanger 43 side are driven in the forward rotation, and the cooling fan 47 and the cooling fan located on the second heat exchanger 44 side are driven in the forward rotation. The reverse rotation drive of 48 (second cooling fan) continues at the same time for a predetermined time.

On the other hand, if NO (the second heat exchanger 44 is normal) is determined in step S40, the controller 70 returns to the start and repeats a series of control procedures (steps S10 to 50).

Secondly, as shown in FIG. 7, when the operation of the hydraulic excavator 1 is terminated, the controller 70 first cleans the object to be cleaned regardless of the presence or absence of abnormalities in the first and second heat exchangers 43 and 44. The cleaning operation (second operation and third operation) of sequentially changing from the heat exchanger 43 to the second heat exchanger 44 is executed.

Specifically, when the off signal of the key switch 12a shown in FIG. 5 is input, the controller 70 first performs a cleaning operation (second operation of the cooling fan) for the first heat exchanger 43 as a cleaning target. It is executed (step S110 shown in FIG. 7). Specifically, the fan control unit 83 outputs a reverse rotation command to the electric motors 53 corresponding to the cooling fans 45 and 46 (first cooling fan) for a predetermined time, respectively, as in step S30 shown in FIG. At the same time, a forward rotation command is output to the electric motors 53 corresponding to the cooling fans 47 and 48 (second cooling fan) for a predetermined time, respectively.

Next, the controller 70 executes a cleaning operation (third operation of the cooling fan) for the second heat exchanger 44 as a cleaning target (step S120 shown in FIG. 7). Specifically, the fan control unit 83 outputs a forward rotation command to the electric motors 53 corresponding to the cooling fans 45 and 46 (first cooling fan) for a predetermined time, respectively, as in step S50 shown in FIG. At the same time, a reverse rotation command is output to the electric motors 53 corresponding to the cooling fans 47 and 48 (second cooling fan) for a predetermined time, respectively.

Next, the fan control unit 83 outputs a stop command to the electric motors 53 corresponding to the cooling fans 45, 46, 47, and 48 (step S130 shown in FIG. 7), and ends a series of control procedures. As a result, the cooling fans 45, 46, 47, 48 are all stopped.

Next, the operation of the first embodiment of the construction machine of the present invention will be described with reference to FIGS. 3, 4, 6 to 10. FIG. 8 is an explanatory diagram showing the flow of cooling air during normal operation of the cooling fan according to the first embodiment of the construction machine of the present invention. FIG. 9 is an explanatory diagram showing the flow of air flow during a cleaning operation for cleaning the first heat exchanger in the first embodiment of the construction machine of the present invention. FIG. 10 is an explanatory diagram showing the flow of air flow during a cleaning operation for cleaning the second heat exchanger in the first embodiment of the construction machine of the present invention. In FIGS. 8 to 10, the white arrows indicate the flow and direction of the cooling air or air flow.

In the hydraulic excavator 1 according to the present embodiment, the heat generated by the operation of the engine 31 shown in FIG. 3 is cooled by the cooling water, and the cooling water whose temperature has risen flows into the radiator as the first heat exchanger 43. Further, the hydraulic pump 32 is driven by the engine 31 and the hydraulic oil circulates in the hydraulic system to generate heat, and the hydraulic oil whose temperature has risen flows into the oil cooler as the second heat exchanger 44. While the hydraulic excavator 1 is in operation, the cooling fans 45, 46, 47, and 48 are rotationally driven, so that outside air is sucked into the machine room 20 from the suction port 23a of the left side cover 23 of the machine room 20 shown in FIG. It is supplied to the radiator 43 and the oil cooler 44 as cooling air.

Specifically, the controller 70 shown in FIG. 4 executes normal operation and outputs a forward rotation command to the electric motors 53 of the cooling fans 45, 46, 47, and 48 (step S10 shown in FIG. 6). .. As a result, the cooling fans 45, 46, 47, and 48 are all driven in the forward rotation. As shown in FIG. 8, the outside air is taken into the first ventilation passage 41 from the first opening 41a side by the forward rotation of the cooling fans 45 and 46 (first cooling fan), and the radiator 43 is used as the cooling air C1. Is supplied to. Further, by the forward rotation of the cooling fans 47 and 48 (second cooling fan), the outside air is taken into the second ventilation passage 42 from the first opening 42a side and supplied to the oil cooler 44 as the cooling air C2. ..

In the radiator 43, the cooling water is cooled by heat exchange between the cooling water and the cooling air C1 flowing through the first ventilation passage 41. The cooling water is maintained at a temperature below a predetermined temperature by circulating between the engine 31 and the radiator 43. In the oil cooler 44, the hydraulic oil is cooled by heat exchange between the hydraulic oil and the cooling air C2 flowing through the second ventilation passage 42. The hydraulic oil is maintained at a temperature below a predetermined temperature by circulating in the hydraulic system via the oil cooler 44.

The cooling air C1 whose temperature has risen due to heat exchange with the cooling water and the cooling air C2 whose temperature has risen due to heat exchange with the hydraulic oil flow through the gap between the cover 21 of the machine room 20 and the engine 31, and finally the upper cover. It is discharged to the outside of the machine room 20 from the exhaust portion 27a (see FIG. 2) of 27. In this way, by releasing the heat generated in the engine 31 and the heat generated in the hydraulic oil to the outside of the hydraulic excavator 1, overheating of the engine 31 and the hydraulic system is prevented.

The hydraulic excavator 1 may operate in a harsh environment with a lot of dust. In this case, dust is contained in the outside air as the cooling air C1 and C2 sucked into the inside of the machine room 20 by driving the cooling fans 45, 46, 47, and 48. Therefore, when the cooling air C1 and C2 containing dust pass through the radiator 43 and the oil cooler 44, the dust adheres to the surface of the radiator 43 and the oil cooler 44. If the surface of the radiator 43 or the oil cooler 44 is covered by the continuous adhesion of dust or the radiator 43 or the oil cooler 44 is clogged, the heat exchange amount of the radiator 43 or the oil cooler 44 may decrease or the radiator may be clogged. The air volume of the cooling air C1 and C2 passing through the 43 and the oil cooler 44 may decrease. As a result, the cooling performance of the radiator 43 and the oil cooler 44 may deteriorate, causing the engine 31 and the hydraulic system to overheat.

Therefore, in the present embodiment, by switching from the normal operation to the predetermined cleaning operation when the controller 70 is in a predetermined condition, the dust adhering to the radiator 43 and the oil cooler 44 is automatically and efficiently removed, and the engine is used. This is to prevent overheating of 31 and the hydraulic system.

Specifically, the controller 70 shown in FIG. 4 compares the detection value T1 from the first temperature sensor 61 with the first threshold value S1 and from the second temperature sensor 62 during the execution of the above-mentioned normal operation. By comparing the detected value T2 of the above with the second threshold value S2, it is determined whether or not a temperature abnormality has occurred in the radiator 43 (step S20 shown in FIG. 6). When the cumulative operating time of the hydraulic excavator 1 is short, even if dust adheres to the surface of the radiator 43 or the oil cooler 44, the cooling performance of the radiator 43 or the oil cooler 44 does not significantly deteriorate. In this case, since the detected value T1 is equal to or less than the first threshold value S1 and the detected value T2 is equal to or less than the second threshold value S2, the controller 70 determines that the radiator 43 is normal (NO).

Next, the controller 70 compares the detected value T3 from the third temperature sensor 63 with the third threshold value S3, and compares the detected value T4 from the fourth temperature sensor 64 with the fourth threshold value S4. , It is determined whether or not an abnormality has occurred in the oil cooler 44 (step S40 shown in FIG. 6). The detection value T3 is equal to or less than the third threshold value S3, and the detection value T4 is equal to or less than the fourth threshold value S4, and the controller 70 determines that the oil cooler 44 is normal (NO).

When the controller 70 determines that the radiator 43 and the oil cooler 44 are normal, the controller 70 returns to the start and continues the normal operation (step S10 shown in FIG. 6). While the normal operation is being continued, the controller 70 repeats steps S10, S20, and S40 shown in FIG. 6 in order until the temperature abnormality of the radiator 43 and the oil cooler 44 is determined.

When the cumulative operating time of the hydraulic excavator 1 becomes long, dust may cover the surface of the radiator 43 or the radiator 43 may be clogged. In this case, the amount of heat exchanged by the radiator 43 and the amount of air passing through the radiator 43 are reduced, and the detected value T1 from the first temperature sensor 61 and the detected value T2 from the second temperature sensor 62 indicating the temperature of the radiator 43. At least one is greater than the corresponding first threshold S1 or second threshold S2.

In this case, the controller 70 determines that the temperature of the radiator 43 is abnormal (YES) in step S20 shown in FIG. 6, and executes a cleaning operation (second operation of the cooling fan) targeting the radiator 43 for cleaning (FIG. 6). Step S30) shown. As a result, the cooling fans 45 and 46 (first cooling fan) are driven in reverse rotation for a predetermined time, and at the same time, the cooling fans 47 and 48 (second cooling fan) are driven in forward rotation for a predetermined time.

As shown in FIG. 9, due to the forward rotation of the cooling fans 47 and 48 (second cooling fan) located on the side of the oil cooler 44 that is not the object of cleaning, the second ventilation passage 42 is similar to that during normal operation. The outside air taken in from the side of the first opening 42a is supplied to the oil cooler 44 as cooling air C2. A part of the cooling air C2 discharged from the cooling fans 47 and 48 (second cooling fan) passing through the oil cooler 44 is turned by the engine 31 as a barrier portion, and is a continuous passage formed by the engine 31. It goes to the second opening 41b side of the first ventilation passage 41 through 35. The rest of the cooling air C2 that has passed through the oil cooler 44 flows through the gap between the cover 21 of the machine room 20 and the engine 31 and is discharged to the outside of the machine room 20.

On the other hand, due to the reverse rotation of the cooling fans 45 and 46 (first cooling fan) located on the radiator 43 side to be cleaned, the air in the space on the engine 31 side of the machine room 20 is brought into the first ventilation passage 41. Cooling air C2 sucked from the 2 opening 41b side and discharged from the cooling fans 47 and 48 (second cooling fan) and turned by the engine 31 enters the first ventilation passage 41 from the second opening 41b side. It is sucked in and supplied to the radiator 43 as an air flow F1. Since this air flow F1 flows in the direction opposite to the cooling air C1 (see FIG. 8) that cools the radiator 43 during normal operation, dust is blown off from the surface of the radiator 43 when passing through the radiator 43. , Is discharged to the outside of the machine room 20 through the suction port 23a. At this time, the partition wall 29 prevents the dust blown from the radiator 43 to the left side cover 23 side from being sucked into the suction side of the cooling fans 47 and 48 (second cooling fan) that rotate in the normal direction.

In the present embodiment, the cooling fans 45, 46 (first cooling fan) located on the radiator 43 side to be cleaned are rotated in the reverse direction, and the cooling fans 47, 48 located on the oil cooler 44 side, which is not the cleaning target, are rotated in the reverse direction. By rotating the (second cooling fan) in the forward direction without stopping, a part of the cooling air C2 discharged from the cooling fans 47, 48 (second cooling fan) is part of the cooling fans 45, 46 (first cooling fan). It flows to the suction side of the cooling fan). That is, the arrangement relationship between the reverse rotation cooling fans 45, 46 (first cooling fan) and the forward rotation cooling fans 47, 48 (second cooling fan) is such that the second ventilation passage 42, the communication passage 35, and the second. It is similar to the state where the ventilation passage 41 of 1 is arranged in series on the connected flow path. Therefore, the cooling fans 45, 46 (first) of reverse rotation, which are arranged in series, are more than when the cooling fans 47, 48 (second cooling fan) located on the side of the oil cooler 44, which is not the object of cleaning, are stopped. The operating points of the cooling fan () and the cooling fans 47, 48 (second cooling fan) that rotate in the forward direction move to the high static pressure side, so that the air volume also increases. That is, the air volume and static pressure of the cleaning air flow F1 supplied to the radiator 43 increase. Therefore, the dust adhering to the radiator 43 can be efficiently removed in a short time.

In addition, dust may cover the surface of the oil cooler 44 or the oil cooler 44 may be clogged. In this case, at least one of the detection value T3 from the third temperature sensor 63 indicating the temperature of the oil cooler 44 and the detection value T4 from the fourth temperature sensor 64 corresponds to the third threshold value S3 or the fourth threshold value S4. Will be larger than.

In this case, the controller 70 determines that the temperature of the oil cooler 44 is abnormal (YES) in step S40 shown in FIG. 6, and executes a cleaning operation (third operation of the cooling fan) for the oil cooler 44 as a cleaning target (FIG. 6). Step S50 shown in 6. As a result, the cooling fans 45 and 46 (first cooling fan) are driven in the forward rotation for a predetermined time, and at the same time, the cooling fans 47 and 48 (second cooling fan) are driven in the reverse rotation for a predetermined time.

As shown in FIG. 10, due to the positive rotation of the cooling fans 45 and 46 (first cooling fan) located on the radiator 43 side that is not the object of cleaning, the inside of the first ventilation passage 41 is the same as during normal operation. The outside air taken in from the first opening 41a side is supplied to the radiator 43 as cooling air C1. A part of the cooling air C1 that has passed through the radiator 43 and is discharged from the cooling fans 45 and 46 (first cooling fan) is turned by the engine 31 and passed through the communication passage 35 to the second ventilation path 42. 2 Toward the opening 42b side. The rest of the cooling air C1 that has passed through the radiator 43 flows through the gap between the cover 21 of the machine room 20 and the engine 31 and is discharged to the outside of the machine room 20.

On the other hand, due to the reverse rotation of the cooling fans 47 and 48 (second cooling fan) located on the oil cooler 44 side to be cleaned, the air in the space on the engine 31 side of the machine room 20 enters the second ventilation passage 42. The cooling air C1 that is sucked in from the second opening 42b side and discharged from the cooling fans 47 and 48 (second cooling fan) and turned by the engine 31 is in the second ventilation passage 42 on the second opening 42b side. Is sucked in and supplied to the oil cooler 44 as an air flow F2. Since this air flow F2 flows in the direction opposite to the cooling air C2 (see FIG. 8) that cools the oil cooler 44 during normal operation, it is seen from the surface of the oil cooler 44 when passing through the oil cooler 44. The dust is blown off and discharged to the outside of the machine room 20 through the suction port 23a. At this time, the partition wall 29 prevents the dust blown from the oil cooler 44 to the left side cover 23 side from being sucked into the suction side of the cooling fans 45 and 46 (first cooling fan) that rotate in the normal direction.

In the present embodiment, the cooling fans 47, 48 (second cooling fan) located on the oil cooler 44 side to be cleaned are rotated in the reverse direction, and the cooling fans 45, 46 located on the radiator 43 side, which is not the cleaning target, are rotated in the reverse direction. By rotating the (first cooling fan) in the forward direction without stopping, a part of the cooling air C1 discharged from the cooling fans 45, 46 (first cooling fan) is part of the cooling fans 47, 48 (second cooling fan). It flows to the suction side of the cooling fan). That is, the arrangement relationship between the reverse rotation cooling fans 47, 48 (second cooling fan) and the forward rotation cooling fans 45, 46 (first cooling fan) is such that the first ventilation passage 41, the communication passage 35, and the second. It is similar to the state where the ventilation passage 42 is arranged in series on the flow path connected to the above. Therefore, the cooling fans 47, 48 (second cooling fan) of reverse rotation, which are arranged in series, are more than when the cooling fans 45, 46 (first cooling fan) located on the radiator 43 side, which is not the object of cleaning, are stopped. The air volume also increases as the operating points of the cooling fan) and the forward-rotating cooling fans 45 and 46 (first cooling fan) move to the high static pressure side. That is, the air volume and static pressure of the cleaning air flow F2 supplied to the oil cooler 44 increase. Therefore, the dust adhering to the oil cooler 44 can be efficiently removed in a short time.

In this way, when it is determined that a temperature abnormality has occurred in the radiator 43 as the first heat exchanger or the oil cooler 44 as the second heat exchanger, the normal operation (step S10 shown in FIG. 6) is performed. By automatically switching to the cleaning operation for the heat exchangers 43 and 44 in which the temperature abnormality has occurred, the dust adhering to the heat exchangers 43 and 44 to be cleaned is removed. When the cleaning operation is completed, the operation is switched to the normal operation again (step S10 shown in FIG. 6).

Further, when the operation of the hydraulic excavator 1 is terminated, the cleaning operation is executed with the radiator 43 and the oil cooler 44 as cleaning targets in order regardless of the presence or absence of abnormalities in the radiator 43 and the oil cooler 44 (step shown in FIG. 7). S110-130). Since the cleaning operation at the end of the operation of the hydraulic excavator 1 is the same as the control procedure of the cleaning operation when the temperature of the heat exchanger is abnormal described above, the description thereof is omitted here. In this way, even when the hydraulic excavator 1 operates in a harsh environment with a lot of dust, the radiator 43 and the oil cooler 44 are automatically cleaned every time the operation of the hydraulic excavator 1 ends, so that the radiator 43 and the oil The cooling performance of the cooler 44 can be easily and surely maintained.

As described above, the hydraulic excavator 1 as a construction machine according to the first embodiment of the present invention is formed by being surrounded by the cover 21 and the partition wall 29 (wall portion) of the machine room 21 extending in one direction. , A first ventilator 41 and a second ventilator 42 having first openings 41a, 42a and second openings 41b, 42b, respectively, arranged in parallel with each other, and the inside of the first ventilator 41. A first heat exchanger 43 arranged in, a second heat exchanger 44 arranged inside the second ventilation passage 42, and a first heat arranged inside the first ventilation passage 41. First cooling fans 45, 46 for cooling the exchanger 43 and second cooling fans 47, 48 for cooling the second heat exchanger 44, which are arranged inside the second ventilation passage 42. And, it is arranged with a gap in the extending direction of the first ventilation passage 41 with respect to the second opening 41b of the first ventilation passage 41, and with respect to the second opening 42b of the second ventilation passage 42. A controller that controls the drive of the engine 31 (barrier portion) arranged with a gap in the extending direction of the second ventilation passage 42, and the first cooling fans 45, 46 and the second cooling fans 47, 48. It is equipped with 70. The first cooling fans 45, 46 and the second cooling fans 47, 48 can be switched between forward rotation and reverse rotation, and the first openings 41a and 42a serve as inflow ports and the second openings during normal rotation. The portions 41b and 42b generate an air flow that serves as an outlet. The space between the first ventilation passage 41 and the engine 31 (barrier portion) and the space between the second ventilation passage 42 and the engine 31 (barrier portion) communicate with each other. When the controller 70 satisfies a predetermined condition, the first cooling fan 45 performs a normal operation (first operation) in which the first cooling fans 45, 46 and the second cooling fans 47, 48 are driven in a forward rotation. , 46 is driven in the reverse rotation, and the second cooling fans 47 and 48 are switched to the cleaning operation (second operation) in which the second cooling fans 47 and 48 are driven in the forward rotation.

According to this configuration, the first cooling fans 45 and 46 are driven in the reverse rotation, while the second cooling fans 47 and 48 are driven in the forward rotation to drive the second cooling fans 47 and 48 in the forward rotation. Since a part of the air flow discharged from the above flows to the suction side of the first cooling fan 45, 46 that rotates in the reverse direction, the first cooling fan 45, 46 that rotates in the reverse direction and the second cooling fan 47, which rotates in the forward direction. The arrangement relationship of 48 is similar to the arrangement in series. Therefore, the air volume and static pressure of the air flow flowing through the first heat exchanger 43 can be increased as compared with the case where the second cooling fans 47 and 48 are stopped. As a result, dust can be efficiently removed from the first heat exchanger 43, and the cleaning workability of the first heat exchanger 43 is improved.

Further, in the present embodiment, the first cooling fan is composed of a plurality of cooling fans 45, 46. Further, in the cleaning operation (second operation), the controller 70 drives the cooling fan 45 and the cooling fan 46 (a plurality of cooling fans) constituting the first cooling fan in reverse rotation. According to this configuration, the entire area of the first heat exchanger 43 can be cleaned at one time.

Further, the hydraulic excavator 1 according to the present embodiment further includes first and second temperature sensors 61 and 62 (temperature detectors) that detect the temperature of the first heat exchanger 43. Further, the above-mentioned predetermined condition is when the temperatures T1 and T2 detected by the first and second temperature sensors 61 and 62 (temperature detectors) exceed the preset threshold values S1 and S2. According to this configuration, the cleaning time of the first heat exchanger 43 can be determined based on the presence or absence of the temperature abnormality of the first heat exchanger 4, so that the first heat exchanger 43 is unnecessarily cleaned. The work can be avoided, and the cleaning work of the first heat exchanger 43 can be efficiently operated.

Further, the hydraulic excavator 1 according to the present embodiment further includes third and fourth temperature sensors 63 and 64 (temperature detectors) that detect the temperature of the second heat exchanger 44. Further, the above-mentioned predetermined condition is when the temperatures T3 and T4 detected by the third and fourth temperature sensors 63 and 64 (temperature detector) exceed the preset threshold values S3 and S4. According to this configuration, the cleaning time of the second heat exchanger 44 can be determined based on the presence or absence of the temperature abnormality of the second heat exchanger 44, so that the second heat exchanger 44 is wastedly cleaned. The work can be avoided, and the cleaning work of the second heat exchanger 44 can be efficiently operated.

Further, in the present embodiment, when the controller 70 inputs an off signal (operation stop instruction signal) of the key switch 12a instructing the operation stop of the hydraulic excavator 1 (construction machine), the heat exchanger to be cleaned Is configured to perform a cleaning operation that changes in sequence. That is, the predetermined condition for the cleaning operation by the controller 70 is the input of the off signal (operation stop instruction signal) of the key switch 12a. According to this configuration, both the first heat exchanger 43 and the second heat exchanger 44 (plural heat exchangers) are automatically cleaned every time the operation of the hydraulic excavator 1 (construction machine) is completed. Preventing deterioration of the cooling performance of the first and second heat exchangers 43 and 44 (plural heat exchangers), and preventing deterioration of the cooling performance of the first and second heat exchangers 43 and 44 (plural heat exchangers) Cooling performance can be easily and reliably maintained.

Next, a second embodiment of the construction machine of the present invention will be described with reference to the drawings. First, the configuration of the second embodiment of the construction machine of the present invention will be described with reference to FIG. FIG. 11 is a block diagram showing a hardware configuration and a functional configuration of a controller constituting a part of the second embodiment of the construction machine of the present invention. In FIG. 11, those having the same reference numerals as those shown in FIGS. 1 to 10 have the same reference numerals, and therefore detailed description thereof will be omitted.

The difference between the second embodiment of the construction machine of the present invention and the first embodiment is the determination method and cleaning of the cleaning operation (second operation and third operation) of the controller 70A shown in FIG. The control method of the cooling fan during operation (second operation and third operation) is different. The controller 70A drives the cooling fans 45, 46, 47, and 48 for cleaning only the region where the temperature abnormality is detected among the plurality of regions of the first heat exchanger 43 and the second heat exchanger 44. Control. Other configurations are the same as in the case of the first embodiment.

Specifically, in the operation switching determination unit 82A of the controller 70A according to the second embodiment, the operation switching determination unit 82 of the first embodiment is any of the first and second heat exchangers 43 and 44. While it is determined whether to execute the cleaning operation (see FIG. 6), the first region or the second region of the first heat exchanger 43 or the second heat exchanger 44 It is for determining whether to execute the cleaning operation for cleaning either the first region or the second region. More specifically, the operation switching determination unit 82A targets the first region of the first heat exchanger 43 by comparing the detection value T1 from the first temperature sensor 61 with the first threshold value S1. Determine if the cleaning operation is to be performed. By comparing the value T2 detected from the second temperature sensor 62 with the second threshold value S2, it is determined whether or not the cleaning operation for the second region of the first heat exchanger 43 is executed. Further, by comparing the detection value T3 from the third temperature sensor 63 with the third threshold value S3, it is determined whether or not the cleaning operation for the first region of the second heat exchanger 44 is executed. By comparing the value T4 detected from the fourth temperature sensor 64 with the fourth threshold value S4, it is determined whether or not the cleaning operation for the second region of the second heat exchanger 44 is executed.

The fan control unit 83A according to the second embodiment is cleaned so that the fan control unit 83 according to the first embodiment drives both of the two cooling fans corresponding to the heat exchangers to be cleaned in reverse rotation. While the operation is performed (see FIGS. 6 and 7), of the two cooling fans corresponding to the heat exchanger to be cleaned, one side of the cooling fan is driven in reverse rotation while the other side is cooled. The cleaning operation is performed so as to stop the fan without rotating it in the reverse direction. The control of the cooling fans 45, 46, 47, 48 in the normal operation is the same as in the case of the first embodiment.

Next, the control procedure of the cleaning operation of the cooling fan by the controller constituting a part of the second embodiment of the construction machine of the present invention will be described with reference to FIGS. 11 to 13. FIG. 12 is a flowchart showing an example of a control procedure of the normal operation and the cleaning operation of the cooling fan during the operation of the construction machine by the controller constituting a part of the second embodiment of the construction machine of the present invention shown in FIG. be. FIG. 13 is a flowchart showing an example of a control procedure for cleaning operation of the cooling fan at the end of operation of the construction machine by the controller constituting a part of the second embodiment of the construction machine of the present invention shown in FIG. In addition, in FIGS. 12 and 13, those having the same reference numerals as those shown in FIGS. 1 to 10 have the same reference numerals, and therefore detailed description thereof will be omitted.

First, as shown in FIG. 12, the controller 70A shown in FIG. 11 executes a normal operation for cooling the first and second heat exchangers 43 and 44 while the hydraulic excavator 1 is in operation (step S10). It was determined that a temperature abnormality occurred in either the first region or the second region of the first heat exchanger 43 or the first region or the second region of the second heat exchanger 44 during the execution of the normal operation. At this time, the area of the heat exchanger having an abnormal temperature is switched to the cleaning operation for cleaning (steps S220 to S290).

Specifically, the operation switching determination unit 82A of the controller 70A compares the detection value T1 from the first temperature sensor 61 with the first threshold value S1 during the execution of the normal operation, thereby exchanging the first heat. It is determined whether or not a temperature abnormality has occurred in the first region of the vessel 43 (step S220). When the detected value T1 is larger than the first threshold value S1, it is determined that the first region of the first heat exchanger 43 has a temperature abnormality (YES). In other cases, that is, when the detected value T1 is equal to or less than the first threshold value S1, it is determined that the first region of the first heat exchanger 43 is normal (NO).

If YES is determined in step S220, the controller 70A executes a cleaning operation targeting the first region of the first heat exchanger 43 for cleaning (step S230 shown in FIG. 12). Specifically, the fan control unit 83A outputs a reverse rotation command to the electric motor 53 corresponding to one cooling fan 45 of the first cooling fan for a predetermined time, and the other cooling fan of the first cooling fan. A stop command is output to the electric motor 53 corresponding to 46 for a predetermined time, and a forward rotation command is output to the electric motor 53 corresponding to the cooling fans 47 and 48 (second cooling fan) for a predetermined time, respectively. As a result, of the cooling fan 45 and the cooling fan 46 (first cooling fan) located on the first heat exchanger 43 side, the cooling fan 45 on the first region side is driven in reverse rotation, and the cooling fan on the second region side is driven. The stop of 46 and the forward rotation drive of the cooling fans 47 and 48 (second cooling fan) located on the side of the second heat exchanger 44 are simultaneously continued for a predetermined time.

On the other hand, when NO is determined in step S220, the controller 70A compares the detection value T2 from the second temperature sensor 62 with the second threshold value S2 to obtain the second region of the first heat exchanger 43. It is determined whether or not a temperature abnormality has occurred (step S240). When the detected value T2 is larger than the second threshold value S2, it is determined that the second region of the first heat exchanger 43 has a temperature abnormality (YES). In other cases, that is, when the detected value T2 is equal to or less than the second threshold value S2, it is determined that the second region of the first heat exchanger 43 is normal (NO).

If YES is determined in step S240, the controller 70A executes a cleaning operation targeting the second region of the first heat exchanger 43 for cleaning (step S250 shown in FIG. 12). Specifically, the fan control unit 83A outputs a stop command to the electric motor 53 corresponding to one cooling fan 45 of the first cooling fan for a predetermined time, and outputs a stop command to the other cooling fan 46 of the first cooling fan. The reverse rotation command is output to the electric motor 53 corresponding to the above for a predetermined time, and the forward rotation command is output to the electric motor 53 corresponding to the cooling fans 47 and 48 (second cooling fan) for a predetermined time, respectively. As a result, of the cooling fan 45 and the cooling fan 46 (first cooling fan) located on the first heat exchanger 43 side, the cooling fan 46 on the second region side is driven in reverse rotation, and the cooling fan on the first region side is driven. The stop of 45 and the positive rotation drive of the cooling fans 47 and 48 (second cooling fan) located on the side of the second heat exchanger 44 are simultaneously continued for a predetermined time.

On the other hand, when NO is determined in step S240, the controller 70A compares the detection value T3 from the third temperature sensor 63 with the third threshold value S3 to obtain the first region of the second heat exchanger 44. It is determined whether or not a temperature abnormality has occurred (step S260). When the detected value T3 is larger than the third threshold value S3, it is determined that a temperature abnormality has occurred in the first region of the second heat exchanger 44 (YES). In other cases, that is, when the detected value T3 is equal to or less than the third threshold value S3, it is determined that the first region of the second heat exchanger 44 is normal (NO).

If YES is determined in step S260, the controller 70A executes a cleaning operation targeting the first region of the second heat exchanger 44 as a cleaning target (step S270 shown in FIG. 12). Specifically, the fan control unit 83A outputs a forward rotation command to the electric motors 53 corresponding to the cooling fans 45 and 46 (first cooling fan) for a predetermined time, and one of the second cooling fans. A reverse rotation command is output to the electric motor 53 corresponding to the cooling fan 47 for a predetermined time, and a stop command is output to the electric motor 53 corresponding to the other cooling fan 48 of the second cooling fan for a predetermined time. As a result, of the cooling fan 47 and the cooling fan 48 (second cooling fan) located on the side of the second heat exchanger 44, the cooling fan 47 on the first region side is driven in reverse rotation, and the cooling on the second region side is cooled. The fan 48 is stopped, and the cooling fans 45 and 46 (first cooling fan) located on the side of the first heat exchanger 43 are continuously driven in the forward rotation for a predetermined time at the same time.

On the other hand, when NO is determined in step S260, the controller 70A compares the detection value T4 from the fourth temperature sensor 64 with the fourth threshold value S4 to obtain the second region of the second heat exchanger 44. It is determined whether or not a temperature abnormality has occurred (step S280). When the detected value T4 is larger than the fourth threshold value S4, it is determined that a temperature abnormality has occurred in the second region of the second heat exchanger 44 (YES). In other cases, that is, when the detected value T4 is equal to or less than the fourth threshold value S4, it is determined that the second region of the second heat exchanger 44 is normal (NO).

If YES is determined in step S280, the controller 70A executes a cleaning operation targeting the second region of the second heat exchanger 44 as a cleaning target (step S290 shown in FIG. 12). Specifically, the fan control unit 83A outputs a forward rotation command to the electric motors 53 corresponding to the cooling fans 45 and 46 (first cooling fan) for a predetermined time, and one of the second cooling fans. A stop command is output to the electric motor 53 corresponding to the cooling fan 47 for a predetermined time, and a reverse rotation command is output to the electric motor 53 corresponding to the other cooling fan 48 of the second cooling fan for a predetermined time. As a result, of the cooling fan 47 and the cooling fan 48 (second cooling fan) located on the second heat exchanger 44 side, the cooling fan 48 on the second region side is driven in reverse rotation, and the cooling fan on the first region side is driven. The stop of 47 and the positive rotation drive of the cooling fans 45 and 46 (first cooling fan) located on the side of the first heat exchanger 43 are simultaneously continued for a predetermined time.

On the other hand, if NO is determined in step S280, the controller 70A returns to the start and repeats a series of control procedures (steps S10, S220 to S290).

Secondly, as shown in FIG. 13, when the operation of the hydraulic excavator 1 is terminated, the controller 70A sequentially cleans the objects to be cleaned regardless of the presence or absence of temperature abnormality of the first and second heat exchangers 43 and 44. A cleaning operation is executed in which each region of the first heat exchanger 43 is changed to each region of the second heat exchanger 44.

Specifically, when the off signal of the key switch 12a shown in FIG. 11 is input, the controller 70A first executes a cleaning operation targeting the first region of the first heat exchanger 43 (FIG. 11). Step S310 shown in 13. Specifically, the fan control unit 83A outputs a reverse rotation command to the electric motor 53 corresponding to one of the cooling fans 45 of the first cooling fan for a predetermined time, as in step S230 shown in FIG. A stop command is output to the electric motor 53 corresponding to the other cooling fan 46 of the cooling fan 1 for a predetermined time, and the electric motor 53 corresponding to the cooling fans 47 and 48 (second cooling fan) is output, respectively. A forward rotation command is output for a predetermined time.

Next, the controller 70A executes a cleaning operation targeting the second region of the first heat exchanger 43 as a cleaning target (step S320 shown in FIG. 13). Similar to step S250 shown in FIG. 12, the fan control unit 83A outputs a stop command to the electric motor 53 corresponding to one of the cooling fans 45 of the first cooling fan for a predetermined time, and outputs a stop command to the first cooling fan. A reverse rotation command is output to the electric motor 53 corresponding to the other cooling fan 46 for a predetermined time, and a forward rotation command is issued to the electric motor 53 corresponding to the cooling fans 47 and 48 (second cooling fan), respectively. Output for a specified time.

Next, the controller 70A executes a cleaning operation targeting the first region of the second heat exchanger 44 as a cleaning target (step S330 shown in FIG. 13). Similar to step S270 shown in FIG. 12, the fan control unit 83A outputs a forward rotation command to the electric motors 53 corresponding to the cooling fans 45 and 46 (first cooling fan) for a predetermined time, and second. A reverse rotation command is output to the electric motor 53 corresponding to one cooling fan 47 of the cooling fan for a predetermined time, and a stop command is issued to the electric motor 53 corresponding to the other cooling fan 48 of the second cooling fan. Output for a specified time.

Further, the controller 70A executes a cleaning operation targeting the second region of the second heat exchanger 44 as a cleaning target (step S340 shown in FIG. 13). Similar to step S290 shown in FIG. 12, the fan control unit 83A outputs a forward rotation command to the electric motors 53 corresponding to the cooling fans 45 and 46 (first cooling fan) for a predetermined time, and second. A reverse rotation command is output to the electric motor 53 corresponding to the other cooling fan 48 of the cooling fan for a predetermined time, and a stop command is issued to the electric motor 53 corresponding to the one cooling fan 47 of the second cooling fan. Output for a specified time.

Finally, the controller 70A outputs a stop command to the electric motor 53 corresponding to each of the cooling fans 45, 46, 47, 48 (step S350 shown in FIG. 13), and ends a series of control procedures. As a result, the cooling fans 45, 46, 47, 48 are all stopped.

Next, the operation of the second embodiment of the construction machine of the present invention will be described with reference to FIGS. 9 to 13. The controller 70A shown in FIG. 11 executes a normal operation similar to that of the first embodiment while the hydraulic excavator 1 is in operation (step S10 shown in FIG. 12). This prevents the engine 31 and the hydraulic system from overheating.

During the execution of this normal operation, the controller 70A sets the detection values T1, T2, T3, and T4 from the first to fourth temperature sensors 61, 62, 63, and 64, respectively, with the corresponding first to fourth threshold values S1. , S2, S3, S4, it is determined whether or not there is an abnormality in the first region or the second region of the first heat exchanger 43 or the first region or the second region of the second heat exchanger 44. (Steps S220, S240, S260, S280 shown in FIG. 12). When the cumulative operating time of the hydraulic excavator 1 is short, the cooling performance of the first heat exchanger 43 and the second heat exchanger 44 does not significantly deteriorate. In this case, since the detected value T1 is equal to or less than the first threshold value S1, the controller 70A determines that the first region of the first heat exchanger 43 is normal (NO in step S220 shown in FIG. 12). Next, since the detected value T2 is equal to or less than the second threshold value S2, it is determined that the second region of the first heat exchanger 43 is normal (NO in step S240 shown in FIG. 12). Next, since the detected value T3 is equal to or less than the third threshold value S3, it is determined that the first region of the second heat exchanger 44 is normal (NO in step S260 shown in FIG. 12). Further, since the detected value T4 is equal to or less than the fourth threshold value S4, it is determined that the second region of the second heat exchanger 44 is normal (NO in step S280 shown in FIG. 12).

When the controller 70A determines that the first region and the second region of the first and second heat exchangers 43 and 44 are normal, the controller 70A returns to the start and continues the normal operation (step S10 shown in FIG. 12). While the normal operation is being continued, the controller 70A determines that there is an abnormality in any of the first region and the second region of the first and second heat exchangers 43 and 44, and the controllers 70A have steps S10 and S220 shown in FIG. , S240, S260, S280 are repeated in order.

When the cumulative operating time of the hydraulic excavator 1 becomes long, the temperature of any of the first region and the second region of the first and second heat exchangers 43 and 44 may rise due to the adhesion of dust.

For example, when the detected value T1 becomes larger than the first threshold value S1, the controller 70A switches to the cleaning operation in which the first region of the first heat exchanger 43 is targeted for cleaning (step S230 shown in FIG. 12). .. As a result, one cooling fan 45 of the first cooling fan rotates in the reverse direction for a predetermined time, the other cooling fan 46 of the first cooling fan is stopped for a predetermined time, and the cooling fans 47, 48 (second cooling fan). Rotates forward for a predetermined time.

As shown in FIG. 9, a part of the cooling air C2 discharged by the positive rotation of the second cooling fans 47 and 48 (see FIG. 4) located on the side of the second heat exchanger 44 that is not the object of cleaning is an engine. It is turned by 31 and heads toward the second opening 41b side of the first ventilation passage 41 through the communication passage 35.

In the first embodiment, the flow of the cooling air discharged from the second cooling fans 47 and 48 and sucked into the second opening 41b of the first ventilation passage 41 is the first cooling fan that rotates in the reverse direction. It was dispersed into two, 45 and 46 (see FIG. 4).

On the other hand, in the present embodiment, of the cooling fans 45 and 46 (first cooling fan) located on the side of the first heat exchanger 43 to be cleaned, the side of the first region where the temperature abnormality is detected. By rotating only the cooling fan 45 in the reverse direction and stopping the cooling fan 46 on the second region side where no abnormality is detected, the cooling fans 47 and 48 (second cooling fan) are discharged from the cooling fan 47 and the first ventilation. The flow of the cooling air sucked into the second opening 41b of the road 41 is concentrated on the cooling fan 45. Therefore, the air flow F1 discharged from the cooling fan 45 has a larger air volume than in the case of the first embodiment and passes through the first region of the first heat exchanger 43 intensively, so that the air flow F1 adheres to the air flow F1. Dust can be efficiently removed from the first region of the first heat exchanger 43 in a short time.

Further, when the cleaning operation (step S250 shown in FIG. 12) in which the second region of the first heat exchanger 43 is targeted for cleaning is executed, only the cooling fan 46 on the second region side where the temperature abnormality is detected is executed. To stop the cooling fan 45 on the first region side where no abnormality is detected, the second opening of the first ventilation path 41 is discharged from the cooling fans 47 and 48 (second cooling fan). The flow of the cooling air sucked into the portion 41b concentrates on the cooling fan 46. Therefore, the air flow discharged from the cooling fan 46 has a larger air volume than in the case of the first embodiment, and intensively passes through the second region of the first heat exchanger 43, so that the attached dust has adhered. Can be efficiently removed from the second region of the first heat exchanger 43 in a short time.

The case where the first region and the second region of the second heat exchanger 44 are targeted for cleaning is the same as the case where the above-mentioned first heat exchanger 43 is targeted for cleaning. That is, when the cleaning operation (step S270 shown in FIG. 12) in which the first region of the second heat exchanger 44 is targeted for cleaning is executed, only the cooling fan 47 on the first region side where the temperature abnormality is detected is executed. Is rotated in the reverse direction to stop the cooling fan 48 on the second region side where no abnormality is detected, so that the second cooling fan 48 is discharged from the cooling fans 45 and 46 (first cooling fan) as shown in FIG. The flow of the cooling air sucked into the second opening 42b of the ventilation passage 42 is concentrated on the cooling fan 47. Therefore, the air flow F2 discharged from the cooling fan 47 has a larger air volume than in the case of the first embodiment, and intensively passes through the first region of the second heat exchanger 44, so that the attached dust Can be efficiently removed from the first region of the second heat exchanger 44 in a short time.

Further, when the cleaning operation (step S290 shown in FIG. 12) in which the second region of the second heat exchanger 44 is targeted for cleaning is executed, the cooling fan 48 on the second region side in which the temperature abnormality is detected is used. By rotating in the reverse direction and stopping the cooling fan 47 on the first region side where no abnormality is detected, the cooling fans 45 and 46 (first cooling fan) are discharged from the second opening of the second ventilation passage 42. The flow of the cooling air sucked into the portion 42b concentrates on the cooling fan 48. Therefore, the air flow discharged from the cooling fan 48 has a larger air volume than in the case of the first embodiment, and intensively passes through the second region of the second heat exchanger 44, so that the attached dust has adhered. Can be efficiently removed from the second region of the second heat exchanger 44 in a short time.

Further, when the operation of the hydraulic excavator 1 is terminated, a cleaning operation for cleaning the first heat exchanger 43 is executed regardless of the presence or absence of temperature abnormality of the first and second heat exchangers 43 and 44. (Steps S310 to 320 shown in FIG. 13), and a cleaning operation for cleaning the second heat exchanger 44 is executed (steps S330 to 340 shown in FIG. 13).

In the cleaning operation (second operation) in which the first heat exchanger 43 is targeted for cleaning, first, the cooling fan 45 located on the first region side of the first heat exchanger 43 is rotated in the reverse direction, and the second region is formed. By stopping the cooling fan 46 located on the side, the air volume of the cooling air C2 discharged from the cooling fans 47 and 48 (second cooling fan) that rotate in the forward direction is concentrated on the cooling fan 45 that rotates in the reverse direction. There is. Next, by stopping the cooling fan 45 on the first region side of the first heat exchanger 43 and rotating the cooling fan 46 located on the second region side in the reverse direction, the cooling fan 46 rotates in the reverse direction. The flow of the cooling air discharged from the cooling fans 47 and 48 (second cooling fan) is concentrated. Therefore, since the air volume of the air flow discharged from the cooling fans 45 and 46 (first cooling fan) to clean the first heat exchanger 43 increases, dust can be removed from the first heat exchanger 43 in a short time. It can be removed efficiently.

Even in the cleaning operation in which the second heat exchanger 44 is targeted for cleaning, first, the cooling fan 47 located on the first region side of the second heat exchanger 44 is rotated in the reverse direction, and the cooling fan 48 on the second region side is rotated. By stopping the cooling fan 47, the flow of the cooling air discharged from the cooling fans 45 and 46 (first cooling fan) rotating in the forward direction is concentrated on the cooling fan 47 rotating in the reverse direction. Next, by stopping the cooling fan 47 on the first region side of the second heat exchanger 44 and rotating the cooling fan 48 located on the second region side in the reverse direction, the cooling fan 48 rotates in the reverse direction. The flow of the cooling air discharged from the cooling fans 45 and 46 (first cooling fan) is concentrated. Therefore, since the air volume of the air flow discharged from the cooling fans 47 and 48 (second cooling fan) to clean the second heat exchanger 44 increases, dust can be removed from the second heat exchanger 44 in a short time. It can be removed efficiently.

In this way, even when the hydraulic excavator 1 operates in a harsh environment with a lot of dust, the first and second heat exchangers 43 and 44 are cleaned every time the operation of the hydraulic excavator 1 is completed. It automatically switches to driving. Thereby, the cooling performance of the first and second heat exchangers 43 and 44 can be easily and surely maintained.

Further, in the cleaning operation (second operation) in which the first heat exchanger 43 according to the embodiment of the present embodiment is to be cleaned, first, the cooling fans 45, 46 (the first) corresponding to the first heat exchanger 43 are used. Of the cooling fans in 1), one is driven in the reverse rotation and the other is stopped, and then the cooling fan that is driven in the reverse rotation is changed to be stopped and the cooling fan that is stopped is rotated in the reverse direction. The cooling fans 45 and 46 (first cooling fan) corresponding to the first heat exchanger 43 are once driven in the reverse rotation by controlling the change so as to be driven by. As a result, the entire first heat exchanger 43 can be cleaned and the air volume of the air flow can be increased.

Further, in the cleaning operation (third operation) in which the second heat exchanger 44 is to be cleaned, first, as in the case of the first heat exchanger 43, cooling is performed corresponding to the second heat exchanger 44. Of the fans 47 and 48 (second cooling fan), one is driven in the reverse rotation and the other is stopped, and then the cooling fan driven in the reverse rotation is changed to be stopped and stopped. By controlling the cooling fan to be driven in the reverse rotation, the cooling fans 47 and 48 (second cooling fan) corresponding to the second heat exchanger 44 are once driven in the reverse rotation. As a result, the entire second heat exchanger 44 can be cleaned and the air volume of the air flow can be increased.

According to the second embodiment of the construction machine of the present invention described above, the first cooling fans 45, 46 of reverse rotation and the second cooling fan of forward rotation are similar to the first embodiment described above. Since the arrangement of 47 and 48 is similar to the arrangement in series, the air flow F1 for cleaning the first heat exchanger 43 is more than when the second cooling fans 47 and 48 are stopped. Air volume increases. Therefore, the dust adhering to the first heat exchanger 43 can be efficiently removed, and the cleaning workability of the first heat exchanger 43 is improved.

Further, in the present embodiment, the first cooling fan is composed of a plurality of cooling fans 45, 46. Further, in the cleaning operation (second operation), the controller 70A rotates one of the cooling fans 45 and the cooling fans 46 (a plurality of cooling fans) constituting the first cooling fan in the reverse rotation. While driving, stop the remaining cooling fans. According to this configuration, the air flow discharged from the second cooling fans 47, 48 that rotate in the forward direction is not dispersed in the cooling fan that stops among the first cooling fans 45, 46, and the cooling rotates in the reverse direction. Focus on the fans. Therefore, as compared with the case of the first embodiment, the air volume of the air flow discharged from the cooling fan that rotates in the reverse direction and passing through the first heat exchanger 43 is larger, so that dust is collected from the first heat exchanger 43. Can be removed more efficiently.

Further, the controller 70A according to the present embodiment is driven by reverse rotation among the cooling fan 45 and the cooling fan 46 (a plurality of cooling fans) constituting the first cooling fan in the cleaning operation (second operation). Control is performed to change the cooling fan to be stopped and to drive one of the stopped cooling fans in the reverse rotation, and the control is repeated to form the first cooling fan. The cooling fans 45 and 46 of the above are driven by reverse rotation. According to this configuration, the cleaning operation (second operation) can surely provide the air flow for cleaning to the entire first heat exchanger 43 to be cleaned.

The present invention is not limited to the present embodiment, and includes various modifications. The above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. It is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

For example, in the first and second embodiments of the construction machine of the present invention described above, an example in which the construction machine of the present invention is applied to the hydraulic excavator 1 is shown, but the present invention describes a hydraulic crane, a wheel loader, or the like. It can be widely applied to various construction machines.

Further, in the above-described embodiment, an example in which the electric motor 53 is used as the drive device for the cooling fans 45, 46, 47, 48 is shown, but a hydraulic motor can also be used.

Further, in the above-described embodiment, an example of the cooling device 40 including the two heat exchangers of the first heat exchanger 43 and the second heat exchanger 44 has been described. However, the cooling device can also be configured to include three or more heat exchangers. The cooling device may further include, for example, a heat exchanger such as an intercooler for cooling the intake air of the engine 31 and a condenser for cooling the air conditioner.

Further, in the above-described embodiment, an example is shown in which two ventilation passages, a first ventilation passage 41 and a second ventilation passage 42, are formed in the machine room 20. However, it is also possible to form three or more ventilation passages according to the number of heat exchangers. Further, an example is shown in which the first ventilation passage 41 and the second ventilation passage 42 are formed by a part of the cover 21 of the machine room 20 and the partition wall 29. However, it is also possible to form the plurality of ventilation passages by arranging a plurality of cylindrical members composed of wall portions in parallel without using the cover 21 of the machine room 20.

Further, in the above-described embodiment, when the off signal (operation stop instruction signal) of the key switch 12a is input, the normal operation (first operation) is switched to the cleaning operation (second operation and third operation). An example in which the controllers 70 and 70A are configured is shown in the above. However, the controller can also be configured to switch from normal operation (first operation) to cleaning operation (second operation and third operation) when the engine 31 as a prime mover is stopped. In this case, in the flowcharts shown in FIGS. 7 and 13, the stop of the engine 31 is used as the trigger for the start.

That is, the predetermined condition of the cleaning operation (second operation) by the controllers 70 and 70A is when the engine 31 (motor) is stopped, and the controllers 70 and 70A are the cooling fan 45 and the cooling fan 46 (first cooling fan). After performing a cleaning operation (second operation) for a predetermined time to drive the cooling fan 47 and the cooling fan 48 (second cooling fan) in the forward rotation while driving the cooling fan 47 and the cooling fan 48 in the reverse rotation, the cooling fan 47 and the cooling fan 48 are driven. The (second cooling fan) is driven in the reverse rotation, and the cooling fan 45 and the cooling fan 46 (the first cooling fan) are switched to the cleaning operation (third operation) in which the cooling fan 46 is driven in the forward rotation. Even in such a configuration, the first heat exchanger 43 and the second heat exchanger 44 are automatically and sequentially cleaned each time the operation of the hydraulic excavator 1 is completed, so that the first and second heat exchangers are cleaned. It is possible to prevent deterioration of the cooling performance of the first and second heat exchangers 43 and 44 in advance, and to easily and surely maintain the cooling performance of the first and second heat exchangers 43 and 44.

Further, in the first embodiment described above, the first cooling fan for cooling the first heat exchanger 43 is composed of two cooling fans, a cooling fan 45 and a cooling fan 46, and a second cooling fan. An example of a cooling device 40 in which a second cooling fan for cooling the heat exchanger 44 of 2 is composed of two cooling fans, a cooling fan 47 and a cooling fan 48, has been described. However, the cooling device can be configured to install at least one cooling fan for each of the first heat exchanger 43 and the second heat exchanger 44.

Further, in the first embodiment described above, two sensors, a first temperature sensor 61 and a second temperature sensor 62, are arranged in the first heat exchanger 43, and the second heat exchanger 44 is arranged. An example of a configuration in which two sensors, a third temperature sensor 63 and a fourth temperature sensor 64, are arranged is shown. However, it is possible to install at least one temperature sensor for each of the first heat exchanger 43 and the second heat exchanger 44.

Further, in the first embodiment described above, as shown in FIG. 6, after determining the presence / absence of an abnormality in the first heat exchanger 43, the presence / absence of an abnormality in the second heat exchanger 44 is determined. An example was explained. However, it is also possible to determine the presence or absence of an abnormality in the first heat exchanger 43 after determining the presence or absence of an abnormality in the second heat exchanger 44. That is, the order of determining the presence or absence of abnormality in the plurality of heat exchangers is arbitrary.

Further, in the first embodiment described above, as shown in FIG. 7, when the operation of the hydraulic excavator 1 is terminated, after the cleaning operation for the first heat exchanger 43 to be cleaned is executed, the second is performed. An example of executing a cleaning operation in which the heat exchanger 44 of the above is to be cleaned has been described. However, it is also possible to execute the cleaning operation with the first heat exchanger 43 as the cleaning target after the cleaning operation with the second heat exchanger 44 as the cleaning target is executed. That is, the order of the cleaning targets in the cleaning operation at the end of the operation of the hydraulic excavator 1 is arbitrary.

Further, in the second embodiment described above, as shown in FIG. 12, after determining the presence or absence of abnormalities in the first region and the second region of the first heat exchanger 43 in order, the second heat exchange is performed. An example of determining the presence or absence of an abnormality in the first region and the second region of the vessel 44 in order has been described. However, the order of determining the presence or absence of an abnormality in any region of the first heat exchanger 43 and the second heat exchanger 44 is interchangeable and arbitrary.

Further, in the second embodiment described above, as shown in FIG. 13, when the operation of the hydraulic excavator 1 is terminated, the first region and the second region of the first heat exchanger 43 are sequentially targeted for cleaning. An example of executing a cleaning operation in which the first region and the second region of the second heat exchanger 44 are sequentially targeted for cleaning has been described. However, the order of execution of the cleaning operation to be cleaned in any region of the first heat exchanger 43 and the second heat exchanger 44 at the end of the operation of the hydraulic excavator 1 is interchangeable and arbitrary.

In the above-described embodiment, an example of the configuration in which the cover 21 of the machine room 20 includes the rear cover 26 is shown. However, the rear cover 26 can be configured by substituting the wall surface of the counterweight 15.

In the above-described embodiment, the partition wall 29 extends from the left side cover 23 to the engine 31 side. However, the partition wall 29 forms the first and second heat exchangers 43, 44 and the first and second ventilation passages 41, 42 in which the plurality of cooling fans 45, 46, 47, 48 can be arranged. , The configuration may be such that the dust blown from the first and second heat exchangers 43 and 44 to the left side cover 23 side can be prevented from being sucked into the cooling fan of forward rotation.

In the above-described embodiment, an example of a configuration in which the engine 31 functions as a barrier portion is shown. However, the barrier portion is not limited to the engine 31, and the air flow flowing out from the second openings 41b, 42b of the first and second ventilation passages 41, 42 is adjacent to the second and first ventilation passages 42, 41. It can be configured to be able to be turned to the second opening 42b, 41b side of the above, and the shape and number of the barrier portions are arbitrary.

In the above-described embodiment, the temperature sensors 61, 62, 63, 64 are the surface temperature of the core in each region of each heat exchanger 43, 44 or the atmosphere around each region of each heat exchanger 43, 44. An example of the configuration for detecting the temperature is shown. However, each temperature sensor 61, 62, 63, 64 can also be configured to detect the temperature of the fluid flowing in each of the heat exchangers 43, 44.

1 ... Hydraulic excavator (construction machine), 21 ... Cover (wall), 22 ... Lower cover (wall), 25 ... Front cover (wall), 26 ... Rear cover (wall), 27 ... Upper cover (Wall part), 29 ... partition wall (wall part), 31 ... engine (barrier part; prime mover), 35 ... communication passage, 41 ... first ventilation path, 41a ... first opening, 41b ... second opening, 42 ... 2nd ventilation path, 42a ... 1st opening, 42b ... 2nd opening, 43 ... 1st heat exchanger, 44 ... 2nd heat exchanger, 45 ... Cooling fan (1st cooling fan) ), 46 ... Cooling fan (first cooling fan), 47 ... Cooling fan (second cooling fan), 48 ... Cooling fan (second cooling fan), 61 ... First temperature sensor (temperature detector) , 61 ... 1st temperature sensor (temperature detector), 62 ... 2nd temperature sensor (temperature detector), 63 ... 3rd temperature sensor (temperature detector), 64 ... 4th temperature sensor (temperature detection) Vessel), 70, 70A ... Controller

Claims (6)

A first vent and a second vent, which are formed by being surrounded by a wall extending in one direction, have a first opening and a second opening, respectively, and are arranged in parallel with each other.
With the first heat exchanger arranged inside the first ventilation passage,
With the second heat exchanger arranged inside the second ventilation passage,
A first cooling fan, which is arranged inside the first ventilation passage and for cooling the first heat exchanger,
A second cooling fan, which is arranged inside the second ventilation passage and for cooling the second heat exchanger,
The first ventilation passage is arranged with a gap in the extending direction of the first ventilation passage with respect to the second opening, and the second opening of the second ventilation passage is said to have a gap. Barriers arranged with a gap in the extending direction of the second ventilation path,
A controller for controlling the drive of the first cooling fan and the second cooling fan is provided.
The first cooling fan and the second cooling fan can be switched between forward rotation and reverse rotation, and the first opening serves as an inlet and the second opening serves as an outlet during forward rotation. Creates an air flow that
The space between the first ventilation passage and the barrier portion and the space between the second ventilation passage and the barrier portion communicate with each other.
When the predetermined condition is satisfied, the controller drives the first operation of driving the first cooling fan and the second cooling fan in the forward rotation, and drives the first cooling fan in the reverse rotation, and also drives the first cooling fan in the reverse rotation. A construction machine characterized by switching to a second operation in which the second cooling fan is driven in a forward rotation. In the construction machine according to claim 1,
The first cooling fan is composed of a plurality of cooling fans.
The controller is a construction machine characterized in that, in the second operation, all of the plurality of cooling fans of the first cooling fan are driven by reverse rotation. In the construction machine according to claim 1,
The first cooling fan is composed of a plurality of cooling fans.
The controller is characterized in that, in the second operation, one of the plurality of cooling fans of the first cooling fan is driven in reverse rotation, while the remaining cooling fans are stopped. Construction machinery. In the construction machine according to claim 3,
In the second operation, the controller is changed so as to stop the fan driven by the reverse rotation among the plurality of cooling fans of the first cooling fan, and any of the fans that are stopped. A construction machine characterized in that a control is performed to change the fan so that the fan is driven in the reverse rotation, and the control is repeated to drive all the cooling fans constituting the first cooling fan in the reverse rotation. In the construction machine according to claim 1,
Further provided, a temperature detector for detecting the temperature of the first heat exchanger or the temperature of the fluid flowing in the first heat exchanger is provided.
The predetermined condition is a construction machine characterized in that the temperature detected by the temperature detector exceeds any of preset threshold values. In the construction machine according to claim 1,
With more prime movers
The predetermined condition is when the prime mover is stopped.
The controller is characterized in that after performing the second operation for a predetermined time, the second cooling fan is driven in a reverse rotation and the first operation is switched to a third operation in which the first cooling fan is driven in a forward rotation. Construction machinery.

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