JP7767700B2 - Work machinery - Google Patents

Description

The present invention relates to a work machine.

Construction machinery such as hydraulic excavators, which serve as work machines, generally have a cooling fan that draws in air from the construction machinery's external environment to cool the engine. When the cooling fan draws in air from the external environment, a dust prevention device including a dust net is provided upstream of the engine. This prevents dust from entering the area around the engine (see Patent Document 1).

Japanese Patent Application Laid-Open No. 2017-122319

For example, at industrial waste disposal sites, fine dust often floats in the air. This dust occurs when loads are disassembled at the site or lifted with a hydraulic excavator.

If the cooling fan takes in air from the external environment while dust is floating around, there is a possibility that the dust will adhere to the inside of the shovel. For example, if a dustproof net is installed upstream of the engine, as in Patent Document 1, the dust will adhere to the dustproof net. If dust continues to adhere to the internal components of the shovel, such as the dustproof net, the dust will harden, increasing the burden of cleaning.

One aspect of the present invention provides technology that can reduce the burden of cleaning by suppressing the adhesion of dust (including powder dust) inside work machines.

A work machine according to one aspect of the present invention is a work machine comprising a lower running body and an upper rotating body rotatably mounted on the lower running body, and has an engine mounted on the upper rotating body, a fan mounted on the upper rotating body and sending air to the engine , and a detection unit mounted on the upper rotating body that detects dust in the air near the work machine, and controls the fan in accordance with detection information indicating the detection results by the detection unit.

One aspect of the present invention is that it is possible to prevent dust (including powder dust) from adhering, thereby reducing the burden of cleaning.

FIG. 1 is a side view of a shovel according to an embodiment. FIG. 2 is a plan view schematically showing the inside of a house of an upper rotating body in the excavator according to the first embodiment. FIG. 3 is a block diagram showing peripheral devices connected to the controller of the shovel according to the first embodiment. FIG. 4 is a diagram illustrating the concept of the structure of the dust sensor according to the first embodiment. FIG. 5 is a flowchart showing a procedure for controlling the cooling fan based on detection information from the dust sensor in the controller according to the first embodiment. FIG. 6 is a plan view schematically showing the inside of the house of the upper rotating body in the excavator according to the second embodiment.

Embodiments of the present invention will be described below with reference to the drawings. Furthermore, the embodiments described below are illustrative and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention. Furthermore, identical or corresponding components in each drawing will be designated by identical or corresponding reference numerals, and descriptions thereof may be omitted.

The following embodiment describes an example in which a shovel is used as an example of a work machine. However, the following embodiment does not limit the work machine to a shovel, and may be applied to various work machines, such as a wheel loader.

(First embodiment)
1 shows a left side view of a shovel (excavator) according to a first embodiment. In this embodiment, a hydraulic shovel will be taken as an example of the shovel 100.

The excavator 100 is mainly composed of a lower traveling body 1, an upper rotating body 2, and an attachment 3. The upper rotating body 2 is rotatably mounted on the upper part of the lower traveling body 1, and the attachment 3 is attached to the front side of the upper rotating body 2. The attachment 3 includes an excavation attachment consisting of a boom 4, an arm 5, and a bucket 6. Note that the bucket 6 is an example of an end attachment, and instead of the bucket 6, other end attachments such as a grapple, fork, or a harvester including a chainsaw may be attached to the tip of the arm 5 depending on the work content, etc.

In addition, in this specification, the front side of the upper rotating body 2 refers to the side where the boom 4 is attached when viewed from the center of the upper rotating body 2. The left side refers to the side of the upper rotating body 2 that is located to the left when the operator faces forward (in the X1 direction). The right side refers to the side of the upper rotating body 2 that is located to the right when the operator faces forward (in the X1 direction).

The lower traveling body 1 is mainly composed of a pair of left and right crawlers, and is configured to move the shovel forward or backward.

The upper rotating body 2 is mainly composed of a cab 2a, a rotating frame 2b, a house frame 2c, and a house cover 2d. The cab 2a is installed on the front left side of the upper rotating body 2. The rotating frame 2b forms the bottom of the upper rotating body 2 and supports the cab 2a. The house frame 2c forms the framework of the house (building) located on top of the rotating frame 2b and behind the cab 2a. The house cover 2d forms the outer shell of the top and sides of the house.

A boom 4 is pivotally mounted to the front center of the upper rotating body 2 so that it can be raised and lowered, and an arm 5 is connected to the tip of this boom 4 so that it can rotate up and down. Furthermore, a bucket 6 is attached to the tip of the arm 5 so that it can rotate up and down.

The spatial recognition device 80 recognizes objects present in the three-dimensional space around the shovel 100 and acquires spatial recognition information for measuring (calculating) positional relationships, such as the distance from the spatial recognition device 80 or the shovel 100 to the recognized object. Furthermore, the spatial recognition device 80 may recognize objects around the shovel 100 and measure the positional relationship between the recognized object and the spatial recognition device 80 or the shovel 100 based on the acquired spatial recognition information. The spatial recognition device 80 may include, for example, an ultrasonic sensor, millimeter-wave radar, a monocular camera, a stereo camera, LIDAR (Light Detecting and Ranging), a distance image sensor, an infrared sensor, etc.

If the spatial recognition device 80 is a monocular camera or a stereo camera, the spatial recognition information may be, for example, image data captured around the shovel 100.

The spatial recognition device 80 is configured to detect a predetermined object within a predetermined area set around the excavator 100. The spatial recognition device 80 includes a forward recognition sensor 80F attached to the front end of the top surface of the cab 2a, a rear recognition sensor 80B attached to the rear end of the top surface of the upper rotating body 2, a left recognition sensor 80L attached to the left end of the top surface of the upper rotating body 2, and a right recognition sensor 80R attached to the right end of the top surface of the upper rotating body 2. In addition, an upward recognition sensor that recognizes objects present in the space above the upper rotating body 2 may be attached to the excavator 100.

The spatial recognition device 80 may be configured to identify at least one of the type, position, and shape of the object as the specified object to be detected. For example, the spatial recognition device 80 may be configured to distinguish between people and non-human objects. The spatial recognition device 80 may also be configured to identify the type of terrain surrounding the shovel 100. Examples of types of terrain include holes, slopes, and rivers. The spatial recognition device 80 may also be configured to identify the type of obstacle. Examples of types of obstacles include power lines, utility poles, people, animals, vehicles, work equipment, construction machinery, buildings, and fences.

The spatial recognition device 80 may also be configured to identify the type or size of the dump truck. The spatial recognition device 80 may also be configured to detect a person by recognizing at least one of a helmet, a safety vest, work clothes, etc. The spatial recognition device 80 may also be configured to detect a person by recognizing predetermined identification information (e.g., a mark, a QR code (registered trademark)) on at least one of a helmet, a safety vest, work clothes, etc.

Four spatial recognition devices 80 are provided to enable recognition of the entire periphery of the excavator 100. In this embodiment, the spatial recognition devices 80 provided for each direction are referred to as the forward recognition sensor 80F, the left recognition sensor 80L, the rear recognition sensor 80B, and the right recognition sensor 80R.

The dust sensor S1 (an example of a detection unit) detects the amount of dust present in the air near the shovel 100. A detailed configuration will be described later.

Four cooling fans 12A, 12B, 12C, and 12D (hereinafter, any cooling fan may be referred to as a cooling fan 12) are provided inside the house on the left side of the upper rotating body 2 of the excavator 100 to cool the engine.

As shown in FIG. 2, cooling fans 12A, 12B, 12C, and 12D are each connected to a fan motor 16A, 16B, 16C, or 16D (hereinafter, any fan motor may be referred to as a fan motor 16) for rotating the fan. Fan motor 16 operates by receiving power from battery 70.

Figure 2 is a plan view showing the interior of the house of the upper rotating body 2. Figure 2 shows the state with the house cover 2d removed.

As shown in FIG. 2, the interior of the upper rotating body 2 is divided into an engine room 7A and an air cleaner room 7B. The engine room 7A houses a diesel engine 11 (hereinafter simply referred to as the engine 11), four cooling fans 12A-12D, four fan motors 16A-16D, a heat exchanger 13, a turbocharger 61, an exhaust gas treatment device 63, a battery 70, and other components. Specifically, the four cooling fans 12A-12D and the fan motors 16A-16D are installed on the left side (Y1 side) of the engine 11, the turbocharger 61 is installed in front (X1 side) of the engine 11, and the exhaust gas treatment device 63 is installed on the right side (Y2 side) of the engine 11. The heat exchanger 13, which includes a radiator 13A, an oil cooler 13B, an intercooler 13C, a fuel cooler 13D, and an air conditioning condenser 13E, is installed on the left side (Y1 side) of the cooling fan 12. Furthermore, a dustproof net N1 is installed on the left side (Y1 side) of the heat exchanger 13.

The air cleaner 9, hydraulic oil tank 18, etc. are installed within the air cleaner room 7B. Furthermore, a cab 2a and a fuel tank 19 are installed in front of the air cleaner room 7B (X1 side), and a storage space 20 capable of storing tools, etc. is installed in front of the fuel tank 19 (X1 side). Furthermore, the cab 2a is installed on the left side (Y1 side) of the boom 4, and the fuel tank 19 and storage space 20 are installed on the right side (Y2 side) of the boom 4.

The air cleaner 9 takes in air through the air inlet 9a formed on its outer periphery. The air taken in forms a spiral flow around the cylindrical filter 9b and moves to the left (Y1 side). During this process, centrifugal force acts on dust (particles, etc.) in the air, separating the air from the dust. Specifically, the dust in the spiral flow is pressed against the inner wall of the air cleaner 9, moves along the inner wall, and is collected in the vacuator valve (described below). When the dust collected in the vacuator valve reaches a predetermined weight and opens, it is discharged downward. Meanwhile, the air in the spiral flow enters the cylindrical filter 9b when it reaches the left end (Y1 side) of the cylindrical filter 9b. The air that has entered the cylindrical filter 9b is then discharged through the air outlet 9c and supplied to the centrifugal compressor of the turbocharger 61.

The house cover 2d also has opening/closing covers 2d1 and 2d2 on its left side. The hatched shapes in Figure 2 represent the opening/closing covers 2d1 and 2d2 in the closed state, while the dashed lines represent the opening/closing covers 2d1 and 2d2 in the open state.

The dustproof net N1 is provided to prevent dust (an example of dust) from entering the space to the right (Y2 side) of the dustproof net N1 in the engine compartment 7A.

When the fan motors 16A-16D connected to the four cooling fans 12A-12D are driven to rotate, the four cooling fans 12A-12D rotate and send air toward the engine 11. The fan motors 16A-16D are driven to rotate in response to signals from the controller 30, which will be described later. Note that while this embodiment describes a case where there are four cooling fans and fan motors, this is not limited to four and may be three or fewer, or five or more.

When the opening/closing cover 2d1 is open, the four cooling fans 12A-12D rotate, causing the air taken in from the opening/closing cover 2d1 side to pass through the dustproof net N1 and reach the engine 11, thereby cooling the engine 11. Dust and dirt contained in the air taken in from the opening/closing cover 2d1 side adheres to the dustproof net N1. As a result, the air, with the dust and dirt removed, is sent to the engine 11.

At industrial waste disposal sites, etc., disassembly work is often carried out on the objects being loaded, and the objects being lifted by the shovel 100 often contain materials that tend to become airborne, such as lumber or wood chips. For this reason, fine dust tends to become airborne while the shovel 100 is working.

If the excavator 100 continues to work in such an environment, a large amount of dust will continue to adhere to the dustproof net N1. As dust continues to adhere to the dustproof net N1, the dust will tend to adhere to the dustproof net N1. When this situation occurs, the burden of cleaning the dustproof net N1 increases. Furthermore, the flow rate of atmospheric air (outside air) passing through the dustproof net N1 and being sent to the engine 11 decreases.

If this situation continues, the dust will adhere and the air permeable area of the dustproof net N1 will decrease significantly. If the air permeable area decreases significantly, the engine 11 (including the radiator 13A) will not be sufficiently cooled, which could cause the engine 11 to overheat. As a specific example, if the air permeable area of the dustproof net N1 decreases, the interior of the engine 11 could become an enclosed space. If the engine compartment becomes an enclosed space, it will become difficult to release gases heated by the engine 11. If heated gases are no longer released in this way, the engine 11 may not be sufficiently cooled. In this way, even if the change in the external environment of the excavator 100 (for example, the generation of fine dust) is temporary, the performance of the engine 11 may become continuously reduced.

In this embodiment, we will explain an example in which the controller 30 adjusts the rotation speed of the cooling fans 12A to 12D depending on the level of dust present in the air.

Figure 3 is a block diagram showing peripheral devices connected to the controller 30 of the excavator 100 according to this embodiment. In this embodiment, the controller 30 is connected to various peripheral devices via a communication network such as a Controller Area Network (hereinafter referred to as CAN) or a Local Interconnect Network (hereinafter referred to as LIN).

For example, the controller 30 is a controller for controlling the entire excavator 100 and controls the connected peripheral devices. The controller 30 is connected to the image display device 40, dust sensor S1, four cooling fans 12, engine control device 74, and control valve 60 via a communication network such as CAN or LIN.

The image display device 40 is connected to the controller 30 via a communication network such as CAN or LIN. The image display device 40 may also be connected to the controller 30 via a dedicated line.

The image display device 40 also includes a conversion processing unit 40a that generates an image to be displayed on the image display unit 41. In this embodiment, the conversion processing unit 40a generates an image to be displayed on the image display unit 41 based on the output of the spatial recognition device 80. Therefore, the spatial recognition device 80 is connected to the image display device 40, for example, via a dedicated line.

Furthermore, the conversion processing unit 40a converts data to be displayed on the image display unit 41, among the data input to the image display device 40, into an image signal. Note that the data input to the image display device 40 includes, for example, spatial recognition information (e.g., image data) output by each of the forward recognition sensor 80F, left recognition sensor 80L, rear recognition sensor 80B, and right recognition sensor 80R.

The conversion processing unit 40a also generates an image to be displayed on the image display unit 41 based on the output of the controller 30. In this embodiment, the conversion processing unit 40a converts data to be displayed on the image display unit 41, among the data input to the controller 30, into an image signal. Note that the data input to the controller 30 includes, for example, data indicating the temperature of the engine coolant, data indicating the temperature of the hydraulic oil, data indicating the remaining amount of urea water, data indicating the remaining amount of fuel, and data indicating the degree of dust (an example of dust) present in the atmosphere.

The conversion processing unit 40a then outputs the converted image signal to the image display unit 41, causing the corresponding image to be displayed on the image display unit 41.

The conversion processing unit 40a may be realized as a function of the controller 30, rather than as a function of the image display device 40. In this case, the spatial recognition device 80 is connected to the controller 30, not the image display device 40.

The image display device 40 also includes a switch panel 42 as an input unit 42. The switch panel 42 is a panel that includes various hardware switches. In this embodiment, the switch panel 42 includes a light switch 42a, a wiper switch 42b, and a window washer switch 42c as hardware buttons. The light switch 42a is a switch for switching the lights attached to the exterior of the cabin 10 on and off. The wiper switch 42b is a switch for switching the wipers on and off. The window washer switch 42c is a switch for spraying window washer fluid.

The image display device 40 operates by receiving power from a battery 70. The battery 70 is charged with power generated by the alternator 11a (generator) of the engine 11. The power of the battery 70 is also supplied to electrical components 72 of the excavator 100 other than the controller 30 and the image display device 40. The starter 11b of the engine 11 is driven by power from the battery 70 to start the engine 11.

The engine 11 is controlled by an engine control unit (ECU) 74. The ECU 74 constantly transmits various data indicating the state of the engine 11 (for example, data indicating the coolant temperature (physical quantity) detected by the water temperature sensor 11c) to the controller 30. Therefore, the controller 30 stores this data in a temporary storage unit (memory) 30a and can transmit it to the image display device 40 when necessary.

In addition to data indicating the cooling water temperature (physical quantity) detected by the water temperature sensor 11c, various other data are supplied to the controller 30 and stored in the temporary memory unit 30a of the controller 30.

For example, data indicating the swash plate angle is supplied to the controller 30 from the regulator 14a of the main pump 14, which is a variable displacement hydraulic pump. Data indicating the discharge pressure of the main pump 14 is also sent to the controller 30 from the discharge pressure sensor 14b. These data (data representing physical quantities) are stored in the temporary memory unit 30a. An oil temperature sensor 14c is also provided in the pipeline between the main pump 14 and the hydraulic oil tank 18, which stores the hydraulic oil drawn by the main pump 14, and data indicating the temperature of the hydraulic oil flowing through this pipeline is supplied from the oil temperature sensor 14c to the controller 30.

The operating device 26 is a device used by an operator to operate the actuator. The actuator includes at least one of a hydraulic actuator and an electric actuator. In this embodiment, the operating device 26 is a hydraulic operating device that supplies hydraulic oil discharged from the pilot pump 15 to the pilot port of the corresponding spool valve in the control valve unit 17 via a pilot line. The pressure of the hydraulic oil supplied to each pilot port (pilot pressure) corresponds to the operation direction and operation amount of the operating device 26 corresponding to each hydraulic actuator. The operating device 26 includes, for example, a left operating lever, a right operating lever, and a travel operating device. The travel operating device includes, for example, a travel lever and a travel pedal. The operating device 26 may also be an electric operating device.

The operating pressure sensor 29 detects the operation of the operating device 26 by the operator. In this embodiment, the operating pressure sensor 29 detects the operation direction and operation amount of the operating device 26 corresponding to each actuator in the form of pressure (operating pressure), and outputs the detected value to the controller 30. The operation of the operating device 26 may also be detected using a sensor other than the operating pressure sensor.

The engine speed adjustment dial 75 is a dial for adjusting the engine speed of the engine 11. The engine speed adjustment dial 75 outputs data regarding the engine speed setting to the controller 30. The engine speed adjustment dial 75 is configured to switch the engine speed among four modes: SP mode, H mode, A mode, and idling mode. SP mode is a speed mode selected when prioritizing work volume and uses the highest engine speed. H mode is a speed mode selected when prioritizing work volume and fuel efficiency and uses the second highest engine speed. A mode is a speed mode selected when prioritizing fuel efficiency and operating the excavator 100 with low noise and uses the third highest engine speed. Idling mode is a speed mode selected when idling the engine 11 and uses the lowest engine speed. The engine 11 is controlled to maintain a constant engine speed corresponding to the speed mode set by the engine speed adjustment dial 75.

The control valve 60 is configured to switch the operating device 26 between an enabled state and an disabled state. The enabled state of the operating device 26 is a state in which the operator can use the operating device 26 to operate the hydraulic actuator. The disabled state of the operating device 26 is a state in which the operator cannot use the operating device 26 to operate the hydraulic actuator. In this embodiment, the control valve 60 is a gate lock valve configured to operate in response to commands from the controller 30. Specifically, the control valve 60 is disposed in a pilot line connecting the pilot pump 15 and the operating device 26, and is configured to switch between open and closed states of the pilot line in response to commands from the controller 30. The operating device 26 is enabled, for example, when a gate lock lever (not shown) is pulled up to open the gate lock valve, and is disabled when the gate lock lever is pushed down to close the gate lock valve.

The dust sensor S1 is located on the top surface of the upper rotating body 2 and detects the amount of dust present in the air near the shovel. Note that the location of the dust sensor S1 in this embodiment is shown as an example, and it may be located in any position where it can detect dust present in the air, such as inside the upper rotating body 2.

Figure 4 is a diagram illustrating the conceptual structure of the dust sensor S1 according to this embodiment. As shown in Figure 4, the dust sensor S1 has an inlet S1F for taking in air and an outlet S1H for discharging air. The dust sensor S1 also has a flow path S1G that connects the inlet S1F and the outlet S1H. The dust sensor S1 according to this embodiment detects the level of dust contained in the air passing through the flow path S1G.

The dust sensor S1 is equipped with a fan S1C. As the fan S1C exhausts air in the direction of arrow 401, air and dust particles in the air continuously flow in from the inlet S1F as shown by arrow 402, and air and dust particles in the air continuously flow out from the outlet S1H as shown by arrow 403.

The dust sensor S1 is equipped with a light-emitting diode (LED) S1A and a photodiode S1B.

A flow path S1G exists between the photodiode S1B and the light-emitting diode S1A. A dustproof net S1D is provided between the light-emitting diode S1A and the flow path S1G, and a dustproof net S1E is provided between the photodiode S1B and the flow path S1G. This prevents dust from adhering to the photodiode S1B and the light-emitting diode S1A.

Dust particles contained in the air also pass through flow path S1G along with the air. As a result, the light output from light-emitting diode (LED) S1A is reflected by dust particles present in flow path S1G and becomes scattered light. The degree to which the light becomes scattered light increases depending on the amount of dust particles present in flow path S1G.

The photodiode S1B receives the light output by the light-emitting diode (LED) S1A via the flow path S1G. As described above, if dust is present in the flow path S1G, the light output by the light-emitting diode (LED) S1A becomes scattered light, and the light received by the photodiode S1B is attenuated compared to the light output by the light-emitting diode (LED) S1A. The rate of light attenuation changes depending on the amount of dust present in the flow path S1G.

The dust sensor S1 of this embodiment therefore outputs information based on the attenuation rate between the light output by the light-emitting diode (LED) S1A and the light received by the photodiode S1B to the controller 30 as detection information indicating the degree of dust presence.

As a result, the controller 30 can recognize the level of dust present in the air by receiving detection information from the dust sensor S1.

In this embodiment, a method for recognizing the level of dust presence based on the light attenuation rate of the dust sensor S1 has been described, but this method is not limited to this, and any method that can recognize the level of dust presence may be used.

For example, the controller may recognize the level of dust presence based on image data captured by the spatial recognition device 80. One method for recognizing the level of dust presence based on image data captured by the spatial recognition device 80 is to create a learning model in advance for determining whether or not dust is present, and store the created learning model in the controller. The controller then inputs image data obtained from the spatial recognition device 80 into the learning model to determine the level of dust presence. The learning model may have learned judgment conditions for determining the presence or absence of dust based on a dataset including the presence or absence of dust itself, information indicating dust present in the atmosphere, and image data of the atmosphere. Another learning model may have learned judgment conditions for determining the presence or absence of dust based on a dataset including the presence or absence of dust in the work environment, image data of the work environment, and the clarity of the imaged work environment.

Returning to this embodiment, the controller 30 outputs rotation control signals to the four fan motors 16 in accordance with the detection information indicating the detection results from the dust sensor S1. In this way, the controller 30 controls the rotation speeds of the four cooling fans 12.

When the degree of dust presence in the atmosphere (e.g., the rate of light attenuation) calculated based on the detection information is equal to or less than a first threshold, the controller 30 outputs rotation control signals to the four fan motors 16 to rotate the four cooling fans 12 at a predetermined rotation speed. Note that the predetermined rotation speed at which the cooling fans 12 rotate is a value determined depending on the embodiment, and therefore its explanation is omitted. The first threshold is a threshold determined depending on the embodiment as a criterion for dust adhesion to the dustproof net, and therefore its explanation is omitted.

On the other hand, the controller 30 stops the rotation of the four cooling fans 12 when the degree of dust presence in the atmosphere indicated by the detection information (e.g., the rate of light attenuation) is greater than a first threshold. Note that this embodiment describes an example of stopping rotation, but this is not limited to a method of stopping rotation, and it is sufficient if the rotation speed can be reduced compared to a predetermined rotation speed.

Next, the control procedure for the cooling fan 12 in the controller 30 according to the first embodiment will be described. Figure 5 is a flowchart showing the control procedure for the cooling fan 12 in the controller 30 according to the first embodiment based on detection information from the dust sensor S1.

First, the controller 30 outputs a rotation control signal to the fan motor 16, thereby starting rotation control of the cooling fan 12 at a predetermined rotation speed (S501).

Next, the controller 30 acquires detection information indicating the detection results of dust contained in the air from the dust sensor S1 (S502).

The controller 30 determines whether the degree of dust presence in the atmosphere (e.g., the rate of light attenuation) indicated in the acquired detection information is greater than a first threshold (S503).

If the controller 30 determines that the degree of dust present in the atmosphere (e.g., the rate of light attenuation) is greater than the first threshold (S503: Yes), it outputs a stop control signal to the fan motor 16, thereby controlling the cooling fan 12 to stop (S504).

Furthermore, in accordance with instructions from the controller 30, the image display device 40 displays a message that the cooling fan 12 has been stopped, as well as the temperature of the coolant that cools the engine 11 (S506), and then proceeds to processing in S507. The controller 30 obtains the coolant temperature from the water temperature sensor 11c, which detects the temperature of the coolant.

On the other hand, if the controller 30 determines that the level of dust in the air (e.g., the light attenuation rate) is equal to or lower than the first threshold (S503: No), it controls the rotation of the cooling fan 12 by outputting a rotation control signal to the fan motor 16 (S505), and proceeds to processing in S507. Specifically, if the cooling fan 12 is stopped, the controller 30 outputs a control signal to the fan motor 16 to start rotation at a predetermined rotation speed. If the cooling fan 12 is rotating, the controller 30 outputs a control signal to the fan motor 16 to continue rotation control. Furthermore, the controller 30 may rotate the cooling fan 12 during the next period in which the operation of the shovel 100 is stopped after dust detection. Immediately after the operation of the shovel 100 is stopped, it is highly likely that work was being carried out immediately before, resulting in a dusty state. For this reason, it is preferable that the controller 30 rotate the cooling fan 12 a predetermined time after the operation of the shovel 100 has stopped, in other words, after the dust in the air has settled.

The controller 30 then determines whether control of the shovel 100 has ended (S507). If it determines that control has not ended (S507: No), processing is resumed from S502. Control of the shovel 100 may end, for example, when the operator controls to stop the engine 11.

On the other hand, if the controller 30 determines that control of the shovel 100 has ended (S507: Yes), it ends all control.

As described above, the controller 30 according to this embodiment controls the rotation of the cooling fan 12 via the fan motor 16 depending on the level of dust present in the atmosphere. For example, when the level of dust present in the atmosphere is high, stopping the rotation of the cooling fan 12 can prevent dust from adhering to the dustproof net N1. This reduces the burden of cleaning the dustproof net N1 and prevents a decrease in cooling performance for the engine 11 due to clogging of the dustproof net N1.

Furthermore, although an example in which a dustproof net N1 is provided has been described in this embodiment, the dustproof net N1 does not have to be provided. In other words, even if the dustproof net N1 is not provided, if there is a high level of dust in the atmosphere, the adhesion of dust to the periphery of the engine 11 can be suppressed by stopping the rotation of the cooling fan 12. This reduces the cleaning burden. In particular, when performing work that places a low load on the engine 11, continued operation is possible even with the rotation of the cooling fan 12 stopped, simply by the natural release of heated gas within the engine compartment. Therefore, continued operation is sufficient even if the cooling performance for the engine 11 is low.

(Modification 1 of the First Embodiment)
In the above-described embodiment, the rotation control of the cooling fan 12 is described while the shovel 100 is working. However, the rotation control of the cooling fan 12 is not limited to when the shovel 100 is working.

For example, when the control device 26 is disabled by the control valve (gate lock valve) 60, reverse rotation of the cooling fan 12 (rotating in the opposite direction to the normal rotation that cools the engine 11) may be permitted. In other words, when the control device 26 is disabled by the control valve (gate lock valve) 60, no work is being performed by the excavator 100, and therefore no dust is being scattered. In such a situation, the controller 30 outputs a control signal for reverse rotation of the fan motor 16 so that the cooling fan 12 rotates in the reverse direction, thereby removing dust adhering to the dustproof net N1. This is because the direction of the wind passing through the dustproof net N1 is reversed. When the control device 26 is disabled, any condition may be met for reverse rotation of the cooling fan 12. For example, the operator may set reverse rotation, or the controller 30 may periodically control reverse rotation. Note that similar control may be performed in subsequent embodiments.

(Modification 2 of the First Embodiment)
Furthermore, in the above-described embodiment, an example has been described in which whether or not to rotate the cooling fan 12 is switched depending on whether or not the level of dust in the atmosphere is equal to or lower than the first threshold. However, the present invention is not limited to the method of setting only one threshold as in the above-described embodiment, and multiple thresholds may be set.

For example, if the controller 30 determines that the level of dust in the air has exceeded the smaller of two thresholds, it outputs a control signal to the fan motor 16 to reduce the rotation speed of the cooling fan 12. If the level of dust in the air subsequently increases and the controller 30 determines that this level has exceeded the larger of the two thresholds, it outputs a control signal to the fan motor 16 to stop the rotation of the cooling fan 12. Furthermore, the number of thresholds is not limited to two, and three or more may be provided.

By performing the above-described control, the controller 30 of this modified example is able to simultaneously cool the engine 11 and prevent dust from adhering to the dustproof net N1.

Second Embodiment
The first embodiment does not take into consideration what happens after dust adheres to the dustproof net N1. Therefore, the second embodiment will describe a case where control is performed to remove dust that has adhered to the dustproof net.

Figure 6 is a plan view that shows the interior of the house of the upper rotating body 2 in an excavator according to the second embodiment. Figure 6 shows the state with the house cover 2d removed. Note that the same reference numerals are assigned to components similar to those in the first embodiment, and descriptions thereof will be omitted.

In this embodiment, as shown in FIG. 6, the dustproof net N2 is provided upstream (on the left side) of the battery 70 and inside the opening/closing cover 2d1. In other words, when the opening/closing cover 2d1 is open, the dustproof net N2 forms part of the left side of the upper rotating body 2. Note that for clarity, in FIG. 6, the dustproof net N2 is shown on the outside (left side) of the opening/closing cover 2d1 in the closed state, but in reality, the dustproof net N2 is located inside (right side) of the opening/closing cover 2d1 in the closed state.

The four cooling fans 12A-12D rotate, allowing the air (cooling air) to reach the engine 11 through the dustproof net N2. This allows the engine 11 to be cooled.

Furthermore, in this embodiment, vibration members V1 and V2 are provided on the dustproof net N2.

Vibration members V1 and V2 are, for example, vibration motors, and function as vibration sources in response to instructions from controller 30.

In other words, the vibrating members V1 and V2 can vibrate in response to instructions from the controller 30. When the vibrating members V1 and V2 vibrate, dust adhering to the dustproof net N2 can be dropped. In this embodiment, the dustproof net N2 forms part of the left side of the upper rotating body 2, so dust adhering to the dustproof net N2 falls to the ground.

If a dustproof net is installed inside the upper rotating body 2, dust will fall from the dustproof net due to a vibration source, and the dust will accumulate on the floor of the upper rotating body 2. In this situation, when the cooling fan 12 is rotated, the dust that has accumulated on the floor may adhere to the dustproof net again. In other words, the same dust will adhere to the dustproof net again.

In contrast, the excavator 100 according to this embodiment is provided with a dustproof net N2 that forms part of the left side of the upper rotating body 2, thereby preventing the same dust particles from adhering to the dustproof net N2 again.

In this embodiment, the controller 30 instructs the vibrating members V1 and V2 whether to vibrate based on the detection information from the dust sensor S1. For example, when the level of dust present in the air (e.g., the light attenuation rate) indicated by the detection information from the dust sensor S1 is greater than a first threshold, the controller 30 outputs an instruction to the vibrating members V1 and V2 to vibrate. As a result, when the level of dust present in the air increases, the vibrating members V1 and V2 vibrate, thereby preventing dust from adhering to the dustproof net N2.

Note that this embodiment does not limit the timing at which the vibrating members V1 and V2 are vibrated; for example, the vibrating members V1 and V2 may be vibrated constantly.

Also, in this embodiment, as in the first embodiment, the controller 30 controls the rotation of the cooling fan 12 based on detection information from the dust sensor S1.

In other words, in this embodiment, when the level of dust in the air increases, the cooling fan 12 stops rotating and the vibration members V1 and V2 are vibrated, thereby preventing dust from adhering to the dustproof net N2. Because no dust is adhering to the dustproof net N2, the air can reach the engine 11 through the dustproof net N2. This allows the engine 11 to be cooled.

In this embodiment, an example has been described in which the rotation of the cooling fan 12 is suppressed and the vibrating members V1 and V2 are vibrated when the level of dust in the air increases, but this combination of controls is not limited to this, and other controls may also be combined. Furthermore, when the level of dust in the air increases, the controller 30 may only control the vibrating members V1 and V2 to vibrate without stopping the rotation of the cooling fan 12.

(Third embodiment)
In the second embodiment, an example in which the dustproof net N2 is vibrated to remove dust adhering to the dustproof net N2 has been described. However, the method for removing dust adhering to the dustproof net N2 is not limited to the method of vibrating the dustproof net N2. Therefore, in the third embodiment, a method for removing dust adhering to the dustproof net N2 by controlling the rotation of the cooling fan 12 will be described.

In this embodiment, as with the second embodiment, the dustproof net N2 is provided to form part of the left side of the upper rotating body 2. In this embodiment, the vibration members V1 and V2 do not necessarily have to be provided on the dustproof net N2.

As in the above-described embodiment, the controller 30 according to this embodiment determines whether the degree of dust present in the atmosphere (e.g., the rate of light attenuation) is greater than a first threshold value based on the detection information. If it is determined that the degree of dust present in the atmosphere (e.g., the rate of light attenuation) is greater than the first threshold value, the controller 30 stops the rotation of the four cooling fans 12 or reduces the rotation speed.

Then, after stopping the rotation of the four cooling fans 12 or reducing their rotation speed, the controller 30 determines whether the degree of dust presence in the atmosphere (e.g., the rate of light attenuation) in the detection information has become smaller than a second threshold value. The second threshold value is a value smaller than the first threshold value and is set as a criterion for determining that the atmosphere does not contain dust.

Then, when the controller 30 determines that the degree of dust present in the atmosphere (e.g., the rate of light attenuation) has become smaller than the second threshold, it begins controlling the rotation of the four cooling fans 12 in the reverse direction compared to before the determination based on the first threshold.

When the controller 30 determines that the difference is smaller than the second threshold, it begins controlling the rotation of the four cooling fans 12 so that air flows from the engine 11 to the dustproof net N2. In other words, it controls the rotation of the cooling fans 12 so that the air pushes dust adhering to the dustproof net N2 outward (to the left).

In this embodiment, when the level of dust in the air exceeds the first threshold, dust is floating in the air, and the controller 30 stops the cooling fans 12 to prevent clogging of the dustproof net N2. If the level of dust in the air subsequently falls below the second threshold, the controller 30 determines that there is less dust floating in the air, and controls the four cooling fans 12 to rotate in the reverse direction to remove dust adhering to the dustproof net N2. After a predetermined time has elapsed, the controller 30 again controls the rotation of the cooling fans 12, allowing air to flow from the dustproof net N2 to the engine 11.

In this embodiment, the controller 30 performs the above-described control to prevent dust from adhering to the dustproof net N2 and causing clogging.

(Modification of the third embodiment)
In the third embodiment described above, in a situation where the engine 11 is cooled, the dustproof net N2 is provided at a position upstream of the engine 11. However, the position at which the dustproof net is provided is not limited.

In a modified example of the third embodiment, an example will be described in which a second dustproof net is provided downstream of the engine 11 when cooling the engine 11.

The second dustproof net can be located downstream of the engine 11 so as to form part of the right side of the upper rotating body 2. As with the second embodiment, the first dustproof net N2 is located upstream of the engine 11.

As usual, when the cooling fan 12 blows air onto the engine 11, dust adheres to the first dustproof net N2, preventing dust from entering the engine compartment 7A.

As in the third embodiment, after the level of dust in the air increases and the rotation of the four cooling fans 12 is stopped or the rotation speed is reduced, the controller 30 determines whether the level of dust in the air (e.g., the rate of light attenuation) has become smaller than the second threshold value.

Then, when the controller 30 determines that the degree of dust present in the atmosphere (e.g., the rate of light attenuation) has become smaller than the second threshold, it begins controlling the rotation of the four cooling fans 12 while rotating them in reverse. This allows dust adhering to the first dustproof net N2 to be removed.

In this case, the airflow is reversed. In this situation, the second dustproof net is located upstream of the engine 11. In other words, because the second dustproof net is located upstream of the engine 11, dust can be prevented from reaching the engine 11 or the cooling fan 12 even when the cooling fan 12 is rotated in the reverse direction.

In the above-described embodiment and modified examples, it is possible to prevent dust from adhering to the dustproof net provided upstream of the engine 11. This reduces the burden of cleaning the dustproof net. Furthermore, clogging of the dustproof net can be prevented, thereby preventing a decrease in the cooling efficiency of the engine 11.

Even if a dustproof net is not installed, the rotation of the cooling fan 12 can be controlled according to the level of dust present in the air, thereby preventing dust from adhering to the engine 11, etc., thereby reducing the cleaning burden.

The above describes an embodiment of a work machine according to the present invention, but the present invention is not limited to the above embodiment. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. Naturally, these also fall within the technical scope of the present invention.

REFERENCE SIGNS LIST 100 Excavator 1 Lower traveling body 2 Upper rotating body 3 Attachment 4 Boom 5 Arm 6 Bucket 11 Diesel engine 12A, 12B, 12C, 12D Cooling fan 16A, 16B, 16C, 16D Fan motor 30 Controller 80 Space recognition device S1 Dust sensor N1, N2 Dustproof net

Claims (6)

A work machine comprising: a lower traveling body; and an upper rotating body rotatably mounted on the lower traveling body,
an engine provided on the upper rotating body ;
a fan provided on the upper rotating body and configured to send air to the engine ;
a detection unit provided on the upper rotating body that detects dust in the air near the work machine;
and
controlling the fan in accordance with detection information indicating the detection result by the detection unit;
Work machinery. When it is determined that the degree of dust present in the air indicated by the detection information is greater than a first threshold, the rotation speed of the fan is reduced or the fan is stopped.
2. The work machine according to claim 1. A dustproof net is attached to the upper rotating body and is provided on the upstream side of the fan.
2. The work machine according to claim 1 . The dustproof net is attached to a side surface of the upper rotating body of the work machine.
4. The work machine according to claim 3. Further, a vibration source is attached to the dustproof net and vibrates the dustproof net,
controlling the vibration source in response to the detection information;
A work machine according to claim 3 or 4. when it is determined that the degree of dust present in the air detected by the detection information is smaller than a second threshold, switching the rotation control of the fan so as to send air from the engine to the dustproof net side;
A work machine according to any one of claims 3 to 5.