FAILURE DIAGNOSTIC SYSTEM AND FAILURE DIAGNOSTIC METHOD FOR WORK MACHINE

Abstract

A failure of a component mounted on a work machine is easily identified. A controller acquires time-series data detected in a first period as first snapshot data, and acquires the time-series data detected in a second period after the first period as second snapshot data. A storage unit stores information in which a deviation of a physical quantity from a normal range in order to monitor an operation status of the component, and a failure of the component that is a cause of the deviation are associated with each other. The controller identifies the failure of the component based on the first snapshot data, the second snapshot data, and the information stored in the storage unit.

Description

TECHNICAL FIELD

The present disclosure relates to a failure diagnostic system and a failure diagnostic method for a work machine.

BACKGROUND ART

Japanese Patent Laying-Open No. 2016-151086 (PTL 1) discloses an excavator support apparatus in which time-series data indicating an operation state of a diagnosis target excavator and typical time-series data acquired from a database are compared and displayed on a display apparatus. The above literature describes that it is possible to intuitively confirm abnormality when the abnormality occurs in the diagnosis target excavator by comparing the time-series data of the diagnosis target excavator with the typical time-series data.

CITATION LIST

Patent Literature

• • PTL 1: Japanese Patent Laying-Open No. 2016-151086

SUMMARY OF INVENTION

Technical Problem

Even if one piece of time-series data is acquired and analyzed, it may be difficult to identify a true failure cause.

The present disclosure proposes a failure diagnostic system and a failure diagnostic method for a work machine capable of easily identifying a failure of a component.

Solution to Problem

According to an aspect of the present disclosure, a failure diagnostic system for a work machine is proposed. The failure diagnostic system includes a component mounted on the work machine, a detection unit that detects a predetermined physical quantity in order to monitor an operation status of the component, a controller, and a storage unit. The controller acquires time-series data of the physical quantity detected in a predetermined period as snapshot data. The controller determines whether or not the physical quantity detected by the detection unit is in a normal range. The storage unit stores information in which a deviation of the physical quantity from the normal range and a failure of the component that is a cause of the deviation are associated with each other. The controller acquires, as first snapshot data, the time-series data detected in a first period. The controller acquires, as second snapshot data, the time-series data detected in a second period after the first period. The controller identifies the failure of the component based on the first snapshot data, the second snapshot data, and the information stored in the storage unit.

According to an aspect of the present disclosure, a failure diagnostic method for a work machine is proposed. The work machine includes a component and a detection unit that detects a predetermined physical quantity in order to monitor an operation status of the component. A storage unit stores information in which a deviation of the physical quantity detected by the detection unit from a normal range and a failure of the component that is a cause of the deviation are associated with each other. The failure diagnostic method includes the following steps. A first step is to acquire, as first snapshot data, time-series data of the physical quantity detected in a first period. A second step is to acquire, as second snapshot data, the time-series data of the physical quantity detected in a second period after the first period. A third step is to identify the failure of the component based on the first snapshot data, the second snapshot data, and the information stored in the storage unit.

Advantageous Effects of Invention

According to a failure diagnostic system and a failure diagnostic method for a work machine according to the present disclosure, a failure of a component mounted on the work machine can be easily identified.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view schematically illustrating a configuration of a work machine according to an embodiment of the present disclosure.

FIG. 2 is a system diagram of a cooling system of an engine.

FIG. 3 is a block diagram illustrating a configuration of a system according to the embodiment.

FIG. 4 is a schematic diagram illustrating a first example of a failure cause database.

FIG. 5 is a schematic diagram illustrating a second example of the failure cause database.

FIG. 6 is a diagram of snapshot data when each physical quantity is in a normal range.

FIG. 7 is a diagram of a first example of the snapshot data when the physical quantities deviate from the normal ranges.

FIG. 8 is a diagram of a second example of the snapshot data when the physical quantities deviate from the normal ranges.

FIG. 9 is a diagram of a third example of the snapshot data when the physical quantities deviate from the normal ranges.

FIG. 10 is a diagram of a fourth example of the snapshot data when the physical quantities deviate from the normal ranges.

FIG. 11 is a diagram of a fifth example of the snapshot data when the physical quantities deviate from the normal ranges.

FIG. 12 is a flowchart illustrating a flow of processing for identifying a failure of a component according to the embodiment.

FIG. 13 is a diagram of the snapshot data at a time point when a time has elapsed since occurrence of a failure.

FIG. 14 is a block diagram illustrating a system configuration according to a second embodiment.

FIG. 15 is a block diagram illustrating a system configuration according to a third embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments will be described with reference to the drawings. In the following description, the same components are denoted by the same reference signs. Names and functions thereof are the same. Therefore, detailed descriptions thereof will not be repeated.

First Embodiment

<Overall Configuration of Work Machine>

FIG. 1 is a side view schematically illustrating a configuration of a hydraulic excavator 1 as one example of a work machine according to an embodiment of the present disclosure. As illustrated in FIG. 1, hydraulic excavator 1 mainly includes a traveling body 2, a swing body 3, and a work implement 4. Traveling body 2 and swing body 3 configure a vehicle body of hydraulic excavator 1.

Traveling body 2 has a pair of right and left crawler belts. When the pair of right and left crawler belts are rotationally driven, hydraulic excavator 1 self-travels.

Swing body 3 is installed to be swingable with respect to traveling body 2. Swing body 3 mainly has a cab 7, an engine compartment 5, and a counter weight 6. Cab 7 is disposed, for example, on a front left side of swing body 3. An operator who operates hydraulic excavator 1 boards cab 7. A driver's seat on which the operator sits is disposed inside cab 7. Engine compartment 5 is disposed on a rear side of swing body 3 with respect to cab 7. Engine compartment 5 houses an engine unit (an engine described later, an exhaust treatment structure, and the like). Counter weight 6 is disposed behind engine compartment 5.

Work implement 4 is mounted on a front side of swing body 3. Work implement 4 is disposed, for example, on a right side of cab 7. Work implement 4 can be driven by a hydraulic cylinder. By this driving, work implement 4 is vertically rotatable with respect to swing body 3.

<Configuration of Cooling System>

FIG. 2 is a system diagram of a cooling system of engine 10. Engine 10 is mounted on swing body 3 illustrated in FIG. 1. Engine 10 is housed in engine compartment 5. The cooling system of engine 10 includes a cooling water circulation path 20 through which cooling water circulates. A cooling water pump 22, a water jacket 21A, a thermostat 24, and a radiator 26 are connected in this order through cooling water piping 21. The cooling water pressurized by cooling water pump 22 flows through water jacket 21A, thermostat 24, and radiator 26 in this order. In FIG. 2, arrows along cooling water circulation path 20 indicate a flow direction of the cooling water.

Cooling water pump 22 is driven by a driving force generated by engine 10 to pressure-feed the cooling water. Water jacket 21A is a flow path of the cooling water provided inside engine 10, for example, inside a cylinder block and a cylinder head. Heat generated inside engine 10 is transferred to the cooling water flowing through water jacket 21A, and engine 10 is cooled. The cooling water having received the heat from engine 10 is cooled by heat exchange with air in radiator 26. The cooling water cooled by radiator 26 returns to cooling water pump 22.

Thermostat 24 controls a temperature of the cooling water inside engine 10. When the temperature of the cooling water inside engine 10 is low, thermostat 24 is closed, and the cooling water does not flow to radiator 26. By forming the flow path of the cooling water circulating only inside engine 10, a temperature rise of engine 10 is promoted. When the temperature of the cooling water inside engine 10 increases, thermostat 24 is opened, and the cooling water flows to radiator 26. When the cooling water cooled by radiator 26 circulates to engine 10, engine 10 is cooled by heat radiation to the cooling water.

A reservoir tank 28 is connected to radiator 26. A part of the cooling water is stored in reservoir tank 28. The cooling water appropriately flows from the radiator 26 to reservoir tank 28 or in an opposite direction, so that an appropriate amount of cooling water can be circulated through cooling water circulation path 20.

FIG. 2 also illustrates a hydraulic oil circulation path 30 through which a hydraulic oil circulates. In the present example, the hydraulic oil refers to an oil supplied to hydraulic actuators 40 in order to operate hydraulic actuators 40. Hydraulic actuators 40 each includes, for example, a hydraulic cylinder for driving work implement 4, a swing motor for swinging swing body 3 with respect to traveling body 2, and a traveling motor for traveling the traveling body 2.

A hydraulic oil pump 32, a main valve 34, an oil cooler 36, and a hydraulic oil tank 38 are connected in this order through hydraulic oil piping 31. The hydraulic oil pressurized by hydraulic oil pump 32 flows through main valve 34, oil cooler 36, and hydraulic oil tank 38 in this order. In FIG. 2, arrows along hydraulic oil circulation path 30 indicate a flow direction of the hydraulic oil.

Hydraulic oil tank 38 stores hydraulic oil. Hydraulic oil pump 32 is connected to an output shaft 12 of engine 10 and receives the driving force generated by engine 10 via output shaft 12. Hydraulic oil pump 32 is driven by the driving force of engine 10 to pressure-feed the hydraulic oil inside hydraulic oil tank 38 to main valve 34.

A spool (not illustrated) is built in main valve 34. Main valve 34 controls a flow rate and a direction of the hydraulic oil supplied to each of hydraulic actuators 40 by the spool moving in an axial direction of the spool. The hydraulic oil returned from hydraulic actuators 40 to main valve 34 is cooled by heat exchange with air in oil cooler 36. The hydraulic oil cooled by oil cooler 36 returns to hydraulic oil tank 38.

A bypass valve 37 is provided in hydraulic oil piping 31 between main valve 34 and oil cooler 36. Bypass valve 37 supplies a part of the hydraulic oil to oil cooler 36 for cooling, and directly returns the remaining hydraulic oil to hydraulic oil tank 38 without supplying the remaining hydraulic oil to oil cooler 36. When a temperature of the hydraulic oil is low, a resistance when the hydraulic oil flows increases, and a fuel efficiency decreases. An amount of the hydraulic oil cooled by oil cooler 36 is adjusted by bypass valve 37, by which the temperature of the hydraulic oil is appropriately controlled.

A cooling fan 16 is connected to an output shaft 11 of engine 10. Cooling fan 16 is rotationally driven by receiving the driving force of engine 10 through output shaft 11, thereby generating a flow of air passing through radiator 26 and oil cooler 36. Radiator 26 cools the cooling water by radiating heat to the air flow generated by cooling fan 16. Oil cooler 36 cools the hydraulic oil by radiating heat to the air flow generated by cooling fan 16. Radiator 26 and oil cooler 36 are disposed adjacent to each other. Radiator 26 and oil cooler 36 may be arranged side by side in the flow direction of the air generated by cooling fan 16.

Output shaft 11 of engine 10 is provided with a fan clutch 18. Cooling fan 16 is connected to engine 10 through fan clutch 18. Fan clutch 18 can adjust a number of rotations of cooling fan 16. When the number of rotations of engine 10, the cooling water temperature, and the hydraulic oil temperature of engine 10 are relatively low, and necessity of cooling the cooling water and the hydraulic oil is small, for example, immediately after start of engine 10, transmission of the driving force from engine 10 to cooling fan 16 is reduced, so that noise can be reduced, and loss for driving cooling fan 16 can be reduced. When the number of rotations of engine 10 increases and the cooling water temperature and the hydraulic oil temperature increase, fan clutch 18 is completely connected, and the driving force is transmitted to cooling fan 16 to increase the number of rotations of cooling fan 16, thereby promoting cooling of the cooling water and the hydraulic oil.

<Detection Units 60>

The cooling system illustrated in FIG. 2 is provided with detection units 60 that detect predetermined physical quantities. Detection units 60 include a water temperature sensor 61, an oil temperature sensor 62, a fan rotational number sensor 63, a water level sensor 64, a fuel injection amount sensor 65, and an engine rotational number sensor 66.

Water temperature sensor 61 detects the temperature of the cooling water. The temperature of the cooling water is used to monitor operation statuses of cooling fan 16, cooling water pump 22, thermostat 24, and radiator 26. Oil temperature sensor 62 detects the temperature of the hydraulic oil. The temperature of the hydraulic oil is used to monitor operation statuses of cooling fan 16, hydraulic oil pump 32, oil cooler 36, and bypass valve 37. Fan rotational number sensor 63 detects the number of rotations of cooling fan 16. The number of rotations of cooling fan 16 is used to monitor an operation status of cooling fan 16. In addition, the number of rotations of cooling fan 16 is controlled by a controller 50 in accordance with each of the temperatures detected by water temperature sensor 61 and oil temperature sensor 62.

Water level sensor 64 detects a water level of the cooling water in reservoir tank 28. The water level of the cooling water in reservoir tank 28 is used to monitor operation status of reservoir tank 28 and each instrument configuring cooling water circulation path 20. Fuel injection amount sensor 65 detects a fuel supply amount of fuel supplied to engine 10. The amount of fuel supplied to engine 10 is used to monitor an operation status of engine 10. Engine rotational number sensor 66 detects the number of rotations of engine 10. The number of rotations of engine 10 is used to monitor the operation status of engine 10.

Detection units 60 also include an outside air temperature sensor 67. Outside air temperature sensor 67 detects an outside air temperature in the vicinity of the cooling system. The temperature of the air to be supplied to radiator 26 and oil cooler 36 is detected by outside air temperature sensor 67.

Engine 10, cooling fan 16, cooling water circulation path 20, cooling water pump 22, thermostat 24, radiator 26, reservoir tank 28, hydraulic oil pump 32, oil cooler 36, and bypass valve 37 described above are included in components mounted on hydraulic excavator 1 as one example of the work machine. Detection units 60 detect the predetermined physical quantities in order to confirm the operation statuses of the components. Detection signals indicating the physical quantities detected by detection units 60 are input to controller 50.

Although water temperature sensor 61 illustrated in FIG. 2 is provided inside engine 10, water temperature sensor 61 may be disposed at any position in cooling water circulation path 20. Although oil temperature sensor 62 illustrated in FIG. 2 is provided in hydraulic oil tank 38, oil temperature sensor 62 may be disposed at any position in hydraulic oil circulation path 30.

<Configuration of Controller 50>

FIG. 3 is a block diagram illustrating a configuration of a system according to the embodiment. As illustrated in FIG. 3, controller 50 includes an operation control unit 50A, a physical quantity acquisition unit 50B, a state determination unit 50C, a snapshot data acquisition unit 50D, an arithmetic processing unit 50E, and a storage unit 50F.

An operation apparatus 52 illustrated in FIG. 3 receives an operation of the operator for starting hydraulic excavator 1. Operation apparatus 52 is disposed inside cab 7, for example. Operation apparatus 52 is, for example, an ignition key switch. Operation control unit 50A receives an input of a detection signal indicating that operation apparatus 52 is operated by the operator from operation apparatus 52, and generates an instruction signal for operating hydraulic excavator 1. When a control signal is output from controller 50 to each of the components, each of the component operates. For example, when the instruction signal is output from operation control unit 50A to engine 10, engine 10 is started.

Physical quantity acquisition unit 50B receives, from detection units 60 described with reference to FIG. 2, an input of the signals indicating the physical quantities detected by detection units 60.

Snapshot data acquisition unit 50D generates the time-series data of the physical quantities based on the physical quantities detected by detection units 60 and input to physical quantity acquisition unit 50B. Snapshot data acquisition unit 50D acquires, as snapshot data, data obtained by collecting the time-series data of a plurality of physical quantities detected in a predetermined period. Note that the acquired snapshot data is stored in storage unit 50F, and is erased or updated to newly acquired snapshot data when a predetermined time elapses. Details of the snapshot data will be described later.

State determination unit 50C determines whether each of the physical quantities detected by detection units 60 and input to physical quantity acquisition unit 50B is in a normal range or deviates from the normal range. State determination unit 50C may determine whether or not each of the physical quantities is in the normal range based on the snapshot data.

Snapshot data acquisition unit 50D acquires, as initial snapshot data, time-series data of the physical quantities detected in a predetermined period going back from a time point when state determination unit 50C first determines that any of the physical quantities deviates from the normal range after operation control unit 50A generates the instruction signal. The initial snapshot data is stored in storage unit 50F.

When state determination unit 50C determines that any of the physical quantities deviates from the normal range, arithmetic processing unit 50E identifies a failure of the component that is a cause of the deviation of the physical quantity from the normal range based on the snapshot data acquired by snapshot data acquisition unit 50D. Storage unit 50F stores a failure cause database 50FDB. Failure cause database 50FDB includes information in which the deviation of the physical quantity from the normal range and a failure of the component that is the cause of the deviation are associated with each other. Arithmetic processing unit 50E reads failure cause database 50FDB from storage unit 50F, and identifies one or a plurality of failures of components that cause the deviation when the specific physical quantity deviates from the normal range.

Failure cause database 50FDB further includes information in which the failure of the component and a countermeasure against the failure are associated with each other. Arithmetic processing unit 50E outputs the countermeasure against the failure of the component identified as the cause of the deviation of the physical quantity from the normal range. For example, arithmetic processing unit 50E displays the countermeasure against the failure of the component, for example, on a monitor 54. Monitor 54 is disposed inside cab 7, for example. Monitor 54 is disposed in front of the driver's seat, for example. The operator who boards cab 7 and operates hydraulic excavator 1 can recognize the failure of the component and the countermeasure against the failure by viewing the display of monitor 54.

Each functional block of controller 50 illustrated in FIG. 3 is not necessarily realized by one controller. Controller 50 illustrated in FIG. 3 may be realized by a combination of a plurality of controllers including a part of the functional blocks. For example, physical quantity acquisition unit 50B and arithmetic processing unit 50E may be configured by separate hardware.

<Failure Cause Database 50FDB>

FIG. 4 is a schematic diagram illustrating a first example of failure cause database 50FDB. FIG. 4 illustrates a fault tree. In FIG. 4, an event targeted by the fault tree is overheating of the cooling water of engine 10. The overheating of the cooling water of engine 10 corresponds to an example of the deviation from the normal range of the physical quantity described above.

Occurrence of the overheating of the cooling water of engine 10 is determined by the temperature of the cooling water detected by water temperature sensor 61 deviating from the normal range. A fact that the number of rotations of engine 10 detected by engine rotational number sensor 66 deviates from the normal range and an output of engine 10 decreases may be supplementarily used for determining the occurrence of the overheating.

The overheating of the cooling water occurs due to insufficient heat dissipation of the cooling water or excessive heat generation of engine 10.

The insufficient heat dissipation of the cooling water occurs due to an insufficient amount of cooling water, a circulation defect of the cooling water, an insufficient amount of air blown onto radiator 26 for dissipating the heat from the cooling water, or a high temperature of the air blown onto radiator 26 for dissipating the heat from the cooling water.

The insufficient amount of cooling water is determined by a fact that the water level of the cooling water inside reservoir tank 28 detected by water level sensor 64 deviates from the normal range.

The insufficient amount of cooling water occurs due to leakage of the cooling water or evaporation of the cooling water. The leakage of the cooling water may occur in cooling water piping 21, reservoir tank 28, or radiator 26. The evaporation of the cooling water may occur in radiator 26. Therefore, in this case, the component in which the failure has occurred is identified as any of cooling water piping 21, reservoir tank 28, and radiator 26. A failure event such as the leakage or the evaporation of the cooling water in cooling water piping 21, reservoir tank 28, or radiator 26 and visual inspection as the countermeasure against the failure are associated with each other and stored in storage unit 50F.

The circulation defect of the cooling water occurs due to a defect of cooling water pump 22 or a defect of thermostat 24.

The defect of cooling water pump 22 occurs in cooling water pump 22, and in this case, the component in which the failure has occurred is identified as cooling water pump 22. A failure event such as the defect of cooling water pump 22 and replacement and effect confirmation after the replacement of cooling water pump 22 as the countermeasure against the failure are associated with each other and stored in storage unit 50F.

The defect of thermostat 24 occurs at thermostat 24, and in this case, the component in which the failure has occurred is identified as thermostat 24. A failure event such as the defect of thermostat 24 and the replacement and the effect confirmation after the replacement of thermostat 24 as the countermeasure against the failure are associated with each other and stored in storage unit 50F.

The insufficient amount of air for dissipating the heat from the cooling water occurs due to an insufficient number of rotations of cooling fan 16 or clogging of a heat radiation surface of radiator 26. Hereinafter, the clogging of radiator 26 indicates that the clogging occurs on the heat dissipation surface of radiator 26.

The insufficient amount of air caused by cooling fan 16 is determined by a fact that the number of rotations of cooling fan 16 detected by fan rotational number sensor 63 deviates from the normal range. A fact that the temperature of the hydraulic oil detected by oil temperature sensor 62 deviates from the normal range and the overheating of the cooling water and the overheating of the hydraulic oil occur at the same time may be supplementarily used for determining the occurrence of the insufficient amount of air.

The insufficient number of rotations of cooling fan 16 occurs due to an operation defect of cooling fan 16 or an operation defect of fan clutch 18. In this case, the component in which the failure has occurred is identified as cooling fan 16 or fan clutch 18. A failure event such as the operation defect of cooling fan 16 and inspection, replacement and effect confirmation after the replacement of cooling fan 16 as the countermeasure against the failure are associated with each other and stored in storage unit 50F. A failure event such as the operation defect of fan clutch 18 and inspection, replacement and effect confirmation after repairing of fan clutch 18 as the countermeasure against the failure are associated with each other and stored in storage unit 50F.

The clogging of radiator 26 occurs in radiator 26, and in this case, the component in which the failure has occurred is identified as radiator 26. A failure event such as the clogging of radiator 26, and visual inspection and cleaning of radiator 26 as the countermeasure against the failure are associated with each other and stored in storage unit 50F.

A fact that the temperature of the air blown onto radiator 26 for dissipating the heat from the cooling water is high relates to a fact that the outside air temperature is high. The high outside air temperature is determined by the outside air temperature detected by outside air temperature sensor 67 deviating from the normal range. By visually observing the outside air temperature displayed on monitor 54, the operator can confirm the cause of the problem that the outside air temperature is high.

The excessive heat generation of engine 10 is caused by excessive fuel injection amount to engine 10 or a large resistance or load generated in engine 10.

The excessive fuel injection amount to engine 10 is determined by a fact that the amount of fuel supplied to engine 10 detected by fuel injection amount sensor 65 deviates from the normal range.

The excessive fuel injection amount to engine 10 is caused by an operation defect of an injection pump 14 provided in the fuel supply system to engine 10, and in this case, the component in which the failure has occurred is identified as injection pump 14. A failure event such as the operation defect of injection pump 14, and inspection, replacement and effect confirmation after the replacement of injection pump 14 as the countermeasure against the failure are associated with each other and stored in storage unit 50F.

The large resistance generated in engine 10 is caused by a resistance or a load generated in a component of engine 10, such as a piston or a piston ring, due to a defect such as, for example, wear or damage, and in this case, the component in which the failure has occurred is identified as the piston or the piston ring. A failure event such as the defect of the piston or the piston ring, and inspection, replacement and effect confirmation after the replacement of the piston and the piston ring as the countermeasure for the failure are associated with each other and stored in storage unit 50F.

As described above, by analyzing the detection results of detection units 60 related to the failure of the component, it is possible to easily identify the failure of the component that is the cause of the overheating of the cooling water of engine 10, and in addition, it is possible to easily grasp the countermeasure against the failure.

FIG. 5 is a schematic diagram illustrating a second example of failure cause database 50FDB. FIG. 5 illustrates a fault tree similarly to FIG. 4. In FIG. 5, an event targeted by the fault tree is overheating of the hydraulic oil. The overheating of the hydraulic oil corresponds to one example of the deviation from the normal range of the physical quantity described above. The occurrence of the overheating of the hydraulic oil is determined by the temperature of the hydraulic oil detected by oil temperature sensor 62 deviating from the normal range.

The overheating of the hydraulic oil occurs due to an insufficient amount of air blown onto oil cooler 36 for dissipating the heat from the hydraulic oil, a high temperature of the air blown onto oil cooler 36 for dissipating the heat from the hydraulic oil, or a circulation defect of the hydraulic oil.

The insufficient amount of air for dissipating the heat from the hydraulic oil occurs due to an insufficient number of rotations of cooling fan 16 or clogging of a heat radiation surface of oil cooler 36. Hereinafter, the clogging of oil cooler 36 indicates that the clogging occurs on the heat dissipation surface of oil cooler 36.

The insufficient amount of air caused by cooling fan 16 is determined by a fact that the number of rotations of cooling fan 16 detected by fan rotational number sensor 63 deviates from the normal range. The insufficient number of rotations of cooling fan 16 occurs due to an operation defect of cooling fan 16 or an operation defect of fan clutch 18. In this case, the component in which the failure has occurred is identified as cooling fan 16 or fan clutch 18. A failure event such as the operation defect of cooling fan 16, and inspection, replacement and effect confirmation after the replacement of cooling fan 16 as the countermeasure against the failure are associated with each other and stored in storage unit 50F. A failure event such as the operation defect of fan clutch 18, and inspection, replacement and effect confirmation after the replacement of fan clutch 18 as the countermeasure against the failure are associated with each other and stored in storage unit 50F.

The clogging of oil cooler 36 occurs in oil cooler 36, and in this case, the component in which the failure has occurred is identified as oil cooler 36. A failure event such as the clogging of oil cooler 36, and visual inspection and cleaning of oil cooler 36 as the countermeasure against the failure are associated with each other, and stored in storage unit 50F.

A fact that the temperature of the air blown onto oil cooler 36 for dissipating the heat from the hydraulic oil is high relates to a fact that the outside air temperature is high. The high outside air temperature is determined by the outside air temperature detected by outside air temperature sensor 67 deviating from the normal range. By visually observing the outside air temperature displayed on monitor 54, the operator can confirm the cause of the problem that the outside air temperature is high.

The circulation defect of the hydraulic oil occurs due to a defect of hydraulic oil pump 32 or a defect of bypass valve 37.

The defect of hydraulic oil pump 32 occurs in hydraulic oil pump 32, and in this case, the component in which the failure has occurred is identified as hydraulic oil pump 32. A failure event such as the defect of hydraulic oil pump 32, and inspection, replacement and effect confirmation after the replacement of hydraulic oil pump 32 as the countermeasure against the failure are associated with each other and stored in storage unit 50F.

The defect of bypass valve 37 occurs in bypass valve 37, and in this case, the component in which the failure has occurred is identified as bypass valve 37. A failure event such as the defect of bypass valve 37, and replacement and effect confirmation after the replacement of bypass valve 37 as the countermeasure against the failure are associated with each other and stored in storage unit 50F.

As described above, by analyzing the detection results of detection units 60 related to the failure of the component, it is possible to easily identify the failure of the component that is the cause of the overheating of the hydraulic oil, and in addition, it is possible to easily grasp the countermeasure against the failure.

<Snapshot Data>

Next, data obtained by collecting the time-series data of the plurality of physical quantities detected in the predetermined period, that is, the snapshot data will be described. FIG. 6 is a diagram of the snapshot data when each of the physical quantities is in the normal range.

In FIG. 6 and the drawings illustrating the snapshot data described later, a graph of time-series data of the cooling water temperature with a horizontal axis as time and a vertical axis as temperature, a graph of time-series data of the hydraulic oil temperature with a horizontal axis as time and a vertical axis as temperature, a graph of time-series data of the outside air temperature with a horizontal axis as time and a vertical axis as temperature, a graph of time-series data of the number of rotations of cooling fan 16 with a horizontal axis as time and a vertical axis as the number of rotations, a graph of time-series data of a number of rotations of engine 10 with a horizontal axis as time and a vertical axis as the number of rotations, a graph of time-series data of the water level of the cooling water inside reservoir tank 28 with a horizontal axis as time and a vertical axis as a water level, and a graph of time-series data of the amount of fuel supplied to engine 10 with a horizontal axis as time and a vertical axis as a fuel injection amount are illustrated. The time-series data illustrated in each of the drawings, that is, included in each piece of the snapshot data, indicates a time transition of each of the physical quantities in the same period.

FIG. 6 illustrates the snapshot data when each of the physical quantities is in the normal range. Specifically, in the predetermined period, the cooling water temperature is maintained in a range higher than a threshold at which thermostat 24 is opened, and lower than a threshold at which the cooling water overheats. In the predetermined period, the hydraulic oil temperature is maintained in a range lower than a threshold at which the hydraulic oil overheats, more specifically, in a range lower than a threshold at which the number of rotations of cooling fan 16 is maximized. In the predetermined period, the outside air temperature is maintained in a range lower than a use environment limit temperature, for example, 45° C.

In the predetermined period, the number of rotations of cooling fan 16 is maintained at a substantially maximum number of rotations. In the predetermined period, the number of rotations of engine 10 is substantially maintained at a rated number of rotations at which the driving force generated by engine 10 is maximized. In the predetermined period, the water level of the cooling water inside reservoir tank 28 is substantially maintained at a water level lower than a threshold at which the water level becomes high, and higher than a threshold at which the water level becomes low, more specifically, a water level slightly lower than the threshold at which the water level becomes high. The fuel injection amount to engine 10 is substantially maintained at an injection amount corresponding to a rated number of rotations at which the driving force generated by engine 10 is maximized.

FIG. 7 is a diagram of a first example of the snapshot data when the physical quantities deviate from the normal ranges. FIG. 7 illustrates the snapshot data when the cooling water temperature and the hydraulic oil temperature deviate from the normal ranges. Specifically, the cooling water temperature increases with the lapse of time in the predetermined period, and exceeds the threshold at which the cooling water overheats. The hydraulic oil temperature increases with the lapse of time in the predetermined period, exceeds the threshold at which the number of rotations of cooling fan 16 is maximized, and reaches the threshold at which the hydraulic oil overheats.

The outside air temperature gradually increases with the lapse of time in the predetermined period. It is considered that the temperature of the air that has passed through radiator 26 and oil cooler 36 and been discharged increases as the cooling water temperature and the hydraulic oil temperature reach the thresholds at which the cooling water temperature and the hydraulic oil temperature overheat, and thus outside air temperature sensor 67 detects that the outside air temperature in the vicinity of the cooling system increases.

The time transition of the number of rotations of engine 10, the time transition of the water level of the cooling water inside reservoir tank 28, and the time transition of the fuel injection amount to engine 10 are similar to those in the normal ranges illustrated in FIG. 6.

In the first example illustrated in FIG. 7, both the cooling water temperature and the hydraulic oil temperature have reached the thresholds at which overheating occurs. A common cause between the causes of overheating of the cooling water illustrated in FIG. 4 and the causes of overheating of the hydraulic oil illustrated in FIG. 5 is estimated to be overheating of both the cooling water temperature and the hydraulic oil temperature. That is, it is estimated that the insufficient amount of air for dissipating the heat from the cooling water and the hydraulic oil is a cause of the overheating.

Therefore, referring to the time transition of the number of rotations of cooling fan 16, it is recognized that the number of rotations rapidly increases at a time T when the cooling water temperature reaches the threshold at which thermostat 24 is opened, and is maintained at the substantially maximum number of rotations in a latter half of the predetermined period. It is estimated that the insufficient number of rotations of cooling fan 16 is not the cause among the causes of the insufficient amount of the air illustrated in FIGS. 4, 5. Therefore, the failure event is identified as occurrence of the clogging of radiator 26 and oil cooler 36.

In this manner, arithmetic processing unit 50E (FIG. 3) identifies the failure of the component. Arithmetic processing unit 50E further outputs the countermeasure against the failure of the component. In this case, arithmetic processing unit 50E performs an output for notifying the operator of cleaning for eliminating the clogging of radiator 26 and oil cooler 36. For example, arithmetic processing unit 50E performs, on monitor 54, a display for prompting cleaning for eliminating the clogging of radiator 26 and oil cooler 36.

FIG. 8 is a diagram of a second example of the snapshot data when the physical quantities deviate from the normal ranges. FIG. 8 also illustrates the snapshot data when the cooling water temperature and the hydraulic oil temperature deviate from the normal ranges. Specifically, the cooling water temperature increases with the lapse of time in the predetermined period, and exceeds the threshold at which the cooling water overheats. The hydraulic oil temperature increases with the lapse of time in the predetermined period, and reaches the threshold at which the hydraulic oil overheats.

The outside air temperature is balanced over the predetermined period, but is higher than when it is in the normal range illustrated in FIG. 6. The time transition of the number of rotations of engine 10, the time transition of the water level of the cooling water inside reservoir tank 28, and the time transition of the fuel injection amount to engine 10 are similar to those in the normal ranges illustrated in FIG. 6.

Also in the second example illustrated in FIG. 8, similarly to the first example illustrated in FIG. 7, it is estimated that the insufficient amount of the air for dissipating the heat from the cooling water and the hydraulic oil is a cause of overheating of both the cooling water temperature and the hydraulic oil temperature.

Therefore, referring to the time transition of the number of rotations of cooling fan 16, it is recognized that the number of rotations increases at the time T when the cooling water temperature reaches the threshold at which thermostat 24 is opened, but does not increase up to the maximum number of rotations. The number of rotations of cooling fan 16 takes a value between a middle number of rotations and the maximum number of rotations over the latter half of the predetermined period. It is estimated that the insufficient number of rotations of cooling fan 16 is a cause among the causes of the insufficient amount of the air illustrated in FIGS. 4, 5. Therefore, the failure event is identified as occurrence of the operation defect of cooling fan 16 or fan clutch 18.

In this manner, arithmetic processing unit 50E identifies the failure of the component. Arithmetic processing unit 50E further outputs the countermeasure against the failure of the component. In this case, arithmetic processing unit 50E performs an output for notifying the operator of the inspection, the replacement and the effect confirmation after the replacement of cooling fan 16 and fan clutch 18. For example, arithmetic processing unit 50E performs, on monitor 54, a display for prompting inspection, repair, replacement and subsequent effect confirmation of cooling fan 16 and fan clutch 18.

FIG. 9 is a diagram of a third example of the snapshot data when the physical quantities deviate from the normal ranges. FIG. 9 illustrates the snapshot data when the cooling water temperature deviates from the normal range, while the hydraulic oil temperature is balanced. Specifically, the cooling water temperature increases with the lapse of time in the predetermined period, and exceeds the threshold at which the cooling water overheats. In the predetermined period, the hydraulic oil temperature is maintained in a range lower than the threshold at which the number of rotations of cooling fan 16 is maximized.

The outside air temperature is balanced over the predetermined period. The number of rotations of cooling fan 16 rapidly increases at the time T when the cooling water temperature reaches the threshold at which thermostat 24 is opened, and is maintained at a substantially maximum number of rotations in the latter half of the predetermined period. The time transition of the number of rotations of engine 10, the time transition of the water level of the cooling water inside reservoir tank 28, and the time transition of the fuel injection amount to engine 10 are similar to those in the normal ranges illustrated in FIG. 6.

In the third example illustrated in FIG. 9, it is estimated that the cause of increasing only the cooling water temperature while maintaining the hydraulic oil temperature balanced is a specific cause of causing the overheating of the cooling water that is included in the causes of the overheating of the cooling water illustrated in FIG. 4 and is not included in the causes of the overheating of the hydraulic oil illustrated in FIG. 5. That is, it is estimated that the insufficient amount of air and the high temperature of the air are not causes of the overheating of the cooling water. Since the water level of the cooling water inside reservoir tank 28 is not lowered, it is estimated that the insufficient amount of the cooling water is also not a cause. Since the fuel injection amount is balanced, it is estimated that the excessive fuel injection amount is also not the cause. From these, the failure event is identified as occurrence of a circulation defect of the cooling water.

In this manner, arithmetic processing unit 50E identifies the failure of the component. Arithmetic processing unit 50E further outputs the countermeasure against the failure of the component. In this case, arithmetic processing unit 50E performs an output for notifying the operator of the replacement and the effect confirmation after the replacement of cooling water pump 22 and thermostat 24. For example, arithmetic processing unit 50E performs, on monitor 54, a display for prompting replacement and subsequent effect confirmation of cooling water pump 22 and thermostat 24.

FIG. 10 is a diagram of a fourth example of the snapshot data when the physical quantities deviate from the normal ranges. FIG. 10 also illustrated the snapshot data when the cooling water temperature deviate from the normal range, while the hydraulic oil temperature is balanced. Specifically, the cooling water temperature increases with the lapse of time in the predetermined period, and exceeds the threshold at which the cooling water overheats. In the predetermined period, the hydraulic oil temperature is maintained in a range lower than the threshold at which the number of rotations of cooling fan 16 is maximized.

The outside air temperature is balanced over the predetermined period. The number of rotations of cooling fan 16 rapidly increases at the time T when the cooling water temperature reaches the threshold at which thermostat 24 is opened, and is maintained at a substantially maximum number of rotations in the latter half of the predetermined period. The time transition of the number of rotations of engine 10, and the time transition of the fuel injection amount to engine 10 are similar to those in the normal ranges illustrated in FIG. 6.

Referring to the time transition of the water level of the cooling water inside reservoir tank 28, the water level of the cooling water decreases with the lapse of time in the predetermined period, and is further lower than the threshold at which the water level becomes low.

In the fourth example illustrated in FIG. 10, since the water level of the cooling water inside reservoir tank 28 is lowered, it is estimated that the insufficient amount of the cooling water is a cause of the overheating of the cooling water. Therefore, the failure event is identified as occurrence of leakage of the cooling water in cooling water piping 21, reservoir tank 28, or radiator 26, or evaporation of the cooling water in radiator 26.

In this manner, arithmetic processing unit 50E identifies the failure of the component. Arithmetic processing unit 50E further outputs the countermeasure against the failure of the component. In this case, arithmetic processing unit 50E performs an output for notifying the operator of visual inspection of cooling water piping 21, reservoir tank 28, and radiator 26. For example, arithmetic processing unit 50E performs, on monitor 54, a display for prompting visual inspection of cooling water piping 21, reservoir tank 28, and radiator 26.

FIG. 11 is a diagram of a fifth example of the snapshot data when the physical quantities deviate from the normal ranges. FIG. 11 also illustrates the snapshot data when the cooling water temperature deviates from the normal range, but the hydraulic oil temperature is balanced. Specifically, the cooling water temperature increases with the lapse of time in the predetermined period, and exceeds the threshold at which the cooling water overheats. In the predetermined period, the hydraulic oil temperature is maintained in a range lower than the threshold at which the number of rotations of cooling fan 16 is maximized.

The outside air temperature is balanced over the predetermined period. The number of rotations of cooling fan 16 rapidly increases at the time T when the cooling water temperature reaches the threshold at which thermostat 24 is opened, and is maintained at a substantially maximum number of rotations in the latter half of the predetermined period. The time transition of the number of rotations of engine 10 and the time transition of the water level of the cooling water inside reservoir tank 28 are similar to those in the normal ranges illustrated in FIG. 6.

Referring to the time transition of the fuel injection amount to engine 10, the fuel injection amount exceeds the rated injection amount at which the driving force generated by engine 10 is maximized. The actual fuel injection amount is larger than a target value, and thus fuel efficiency is reduced.

In the fifth example illustrated in FIG. 11, since the fuel injection amount to engine 10 is larger than an injection amount corresponding to rated rotation, it is estimated that the excessive fuel injection amount is a cause of the overheating of the cooling water. Therefore, the failure event is identified as occurrence of an operation defect of injection pump 14.

In this manner, arithmetic processing unit 50E identifies the failure of the component. Arithmetic processing unit 50E further outputs the countermeasure against the failure of the component. In this case, arithmetic processing unit 50E performs an output for notifying the operator of inspection, repair, and replacement and the sequent effect confirmation of injection pump 14. For example, arithmetic processing unit 50E performs, on monitor 54, a display for prompting the inspection and the replacement and visual inspection for effect confirmation after the replacement of injection pump 14.

As described above, controller 50 (arithmetic processing unit 50E) analyzes the snapshot data in which the plurality of the time-series data of physical quantities are arranged, and thus, it is possible to identify, at an early stage, which component among the components of hydraulic excavator 1 is in a failure state.

Arithmetic processing unit 50E may identify the failure of the component based on the snapshot data by using mathematical processing such as smoothing processing. Alternatively, arithmetic processing unit 50E may have an artificial intelligence model for identifying the failure of the component from the snapshot data. The artificial intelligence model may be an artificial intelligence model learned based on learning data including a failure of a certain component and the snapshot data acquired when the failure occurs.

Storage unit 50F (FIG. 3) may previously store typical snapshot data when a failure of a specific component occurs as reference snapshot data. Storage unit 50F may store a plurality of pieces of the reference snapshot data corresponding to various failures. Arithmetic processing unit 50E that has acquired the snapshot data during the operation of hydraulic excavator 1 identifies the reference snapshot data similar to the acquired snapshot data, and reads out a failure corresponding to the identified reference snapshot data, thereby quickly identifying the failure of the component.

Information in which a failure state of the component and the countermeasure against the cause of the failure are associated with each other is stored in the storage unit 50F, by which the information can be read from storage unit 50F when the failure of the component is identified. Based on the information, the countermeasure against the failure can be executed at an early stage, and recovery from the failure can be accelerated.

<Identification of Component Failure>

Next, characteristic processing for identifying a failure of a component based on the embodiment of the present disclosure will be described. FIG. 12 is a flowchart illustrating a flow of processing for identifying the failure of the component according to the embodiment.

As illustrated in FIG. 12, first, preparation for storing the reference snapshot data in storage unit 50F in advance is performed (step S1). The reference snapshot data includes the snapshot data illustrated in FIG. 6 when each of the physical quantities is in the normal range, and also includes the typical snapshot data when the failure of the specific component occurs as illustrated in FIGS. 7 to 11.

The operator performs an operation for starting hydraulic excavator 1 using operation apparatus 52 (FIG. 3). Controller 50 (operation control unit 50A) receives an input of the detection signal indicating that operation apparatus 52 is operated by the operator from operation apparatus 52, and generates the instruction signal for operating hydraulic excavator 1 (step S2).

Detection units 60 detect the predetermined physical quantities in order to confirm the operation statuses of the components mounted on hydraulic excavator 1. Controller 50 (physical quantity acquisition unit 50B) acquires the physical quantity detected by each of detection units 60 from detection unit 60 (step S3).

Controller 50 (state determination unit 50C) determines whether each of the physical quantities detected by detection units 60 and input to physical quantity acquisition unit 50B is in the normal range, or whether the physical quantity deviates from the normal range and the component of which the physical quantity is detected is in a failure state (step S4). When it is determined that the component is not in a failure state (NO in step S4), subsequent processing for identifying a failure is not executed, and the processing returns to the processing for acquiring the physical quantity in step S3.

When it is determined that any of the components is in a failure state (YES in step S4), controller 50 (snapshot data acquisition unit 50D) generates the time-series data of each of the physical quantities input to physical quantity acquisition unit 50B, and acquires, as the snapshot data, the data acquired by collecting the time-series data of the plurality of physical quantities detected in the predetermined period. The snapshot data acquired at this time is time-series data of the physical quantities detected in the predetermined period going back from a time point when it is first determined that the physical quantity deviates from the normal range, and this is referred to as the initial snapshot data (step S5). In this case, the initial snapshot data is time-series data of the physical quantities detected in a period from a time point going back in the predetermined period from the time point when it is first determined that the physical quantity deviates from the normal range to the time point when it is first determined that the physical quantity deviates from the normal range.

Alternatively, the time-series data of the physical quantities detected until a time equivalent to the predetermined period elapses from the time point when it is first determined that the physical quantity deviates from the normal range may be set as the initial snapshot data. The time-series data of the physical quantities detected in the predetermined period including the time point when it is first determined that the physical quantity deviates from the normal range may be set as the initial snapshot data. The initial snapshot data corresponds to first snapshot data of the embodiment. A period in which the time-series data of the physical quantities included in the initial snapshot data is detected corresponds to a first period of the embodiment.

Controller 50 stores the initial snapshot data acquired in step S5 in storage unit 50F (step S6).

Data obtained by collecting the time-series data of the physical quantities in a period after the period in which the initial snapshot data is acquired is acquired as running snapshot data (step S7). For example, when the operator or a repair worker who knows that the component is in a failure state inputs a signal instructing to acquire the snapshot data to controller 50 by operating operation apparatus 52 or the like, controller 50 (snapshot data acquisition unit 50D) may acquire, as the running snapshot data, the snapshot data in the predetermined period going back from a time point when the input is received. In this case, the running snapshot data is time-series data of the physical quantities detected in the period from the time point going back from the time point when controller 50 receives the input for a time equivalent to the predetermined period to the time point when controller 50 receives the input.

Alternatively, the time-series data of the physical quantities detected until the time equivalent to the predetermined period elapses from the time point when controller 50 receives the input may be set as the running snapshot data. The time-series data of the physical quantities detected in the predetermined period including the time point when controller 50 receives the input may be set as the running snapshot data. The running snapshot data corresponds to second snapshot data of the embodiment. The period in which the time-series data of the physical quantities included in the running snapshot data is detected corresponds to a second period of the embodiment.

Note that, after step S6, in a case where none of the physical quantities deviates from the normal range, and in a case where the operator or the repair worker does not perform any operation of inputting the signal instructing to acquire the snapshot data to controller 50 by operating operation apparatus 52 or the like, the processing of step S7 may be skipped.

While the failure of the component determined to be in the failure state in step S4 is not eliminated and the component continues to be in the failure state, controller 50 may continuously or intermittently acquire the snapshot data. Controller 50 may store the latest acquired snapshot data in the storage unit 50F as the running snapshot data and continue updating the running snapshot data. Upon receiving the instruction from the operator or the repair worker, controller 50 may read and output the latest running snapshot data stored in storage unit 50F.

It is determined whether or not the failure of the component can be identified based on the running snapshot data (step S8).

FIG. 13 is a diagram of the snapshot data at a time point when a time has elapsed since the occurrence of the failure. In FIG. 13, the cooling water temperature increases with the lapse of time in the predetermined period, and exceeds the threshold at which the cooling water overheats. The hydraulic oil temperature increases with the lapse of time in the predetermined period, and reaches the threshold at which the hydraulic oil overheats.

The outside air temperature gradually increases with the lapse of time in the predetermined period. The number of rotations of cooling fan 16 rapidly increases at the time T when the cooling water temperature reaches the threshold at which thermostat 24 is opened, and is maintained at a substantially maximum number of rotations in the latter half of the predetermined period. The time transition of the number of rotations of engine 10, and the time transition of the fuel injection amount to engine 10 are similar to those in the normal ranges illustrated in FIG. 6. Referring to the time transition of the water level of the cooling water inside reservoir tank 28, the water level of the cooling water is lower than the threshold at which the water level becomes low over the predetermined period.

The running snapshot data illustrated in FIG. 13 has a waveform different from the typical snapshot data of the failure occurrence included in the reference snapshot data, and it is difficult to identify the failure of the component based on only the running snapshot data.

When it is determined that the failure of the component cannot be identified based on the running snapshot data (NO in step S8), the processing proceeds to step S9, and controller 50 (arithmetic processing unit 50E) reads the initial snapshot data from storage unit 50F (step S9). Controller 50 (arithmetic processing unit 50E) identifies the failure of the component based on the initial snapshot data (step S10).

For example, when the initial snapshot data stored in storage unit 50F is the same as the snapshot data illustrated in FIG. 9, as described with reference to FIG. 9, the failure event is identified as the occurrence of the circulation defect of the cooling water. In this case, at a time point when the failure occurs, the water level of the cooling water inside reservoir tank 28 is slightly lower than the threshold at which the water level becomes high, and there is a sufficient amount of cooling water (FIG. 9). It is estimated that as the overheating of the cooling water continues, the cooling water evaporates and the amount of cooling water decreases, and as a result, the water level of the cooling water in reservoir tank 28 is lowered (FIG. 13). Thereafter, it is estimated that an increase in the outside air temperature has led to the overheating of the hydraulic oil.

In addition, for example, when the initial snapshot data stored in storage unit 50F is the same as the snapshot data illustrated in FIG. 10, as described with reference to FIG. 10, it is estimated that the insufficient amount of cooling water is a cause of the overheating of the cooling water, and the failure event is identified as the occurrence of the leakage or evaporation of the cooling water. Thereafter, it is estimated that an increase in the outside air temperature has led to the overheating of the hydraulic oil.

When the failure of the component can be identified based on the running snapshot data (YES in step S8), the processing in steps S9 and S10 is not performed.

Subsequently, it is determined whether or not there are a plurality of countermeasures against the failure (step S11). For example, when the failure event is identified as occurrence of a circulation defect of the cooling water based on the snapshot data illustrated in FIG. 9, two failure causes of a defect of cooling water pump 22 and a defect of thermostat 24 are estimated. As the countermeasures against the failure, the replacement and the effect confirmation after the replacement of cooling water pump 22, and the replacement and the effect confirmation after the replacement of thermostat 24 are estimated. In such a case, it is determined that there are a plurality of countermeasures against the failure.

When it is determined that there are a plurality of countermeasures against the failure (YES in step S11), the countermeasures are prioritized (step S12). For example, in the case of the circulation defect of the cooling water described above, a history of the failure and repair of cooling water pump 22 and a history of the failure and repair of thermostat 24 are stored in advance in storage unit 50F as maintenance history information, and by reading the maintenance history information, it is possible to determine which component of cooling water pump 22 and thermostat 24 has a high possibility of the failure. As a result of the determination, a countermeasure against the failure corresponding to the component having a high possibility of the failure is output (step S13). This output is performed, for example by controller 50 (arithmetic processing unit 50E) displaying the countermeasure against the failure of the component on the monitor 54.

When it is determined that there is only one countermeasure against the failure (NO in step S11), the processing in step S12 is not performed, and the countermeasure against the identified failure is output in step S13. Then, the processing ends (END in FIG. 12).

<Functions and Effects>

Although there is a description partially overlapping with the above description, the characteristic configurations and effects of the present embodiment will be collectively described as follows.

In the failure diagnostic system according to the embodiment, as illustrated in FIG. 12, the failure of the component is identified based on the initial snapshot data and the running snapshot data acquired after the initial snapshot data. In a case where it is difficult to identify the failure of the component based on only the running snapshot data at the time point when the time has elapsed from the occurrence of the failure, the failure of the component can be identified based on the initial snapshot data. In this way, it is possible to easily identify the failure of the component mounted on hydraulic excavator 1. It is possible to quickly recover from the failure by accurately grasping the cause of the failure of the component and the countermeasure against the cause of the failure and quickly executing the countermeasure. Therefore, a stop time of hydraulic excavator 1 can be shortened, and work efficiency can be improved.

As illustrated in FIG. 12, the failure of the component can be more accurately identified by setting previous snapshot data among the two pieces of snapshot data separated in time series as the initial snapshot data immediately after the failure occurs. Since controller 50 generates the instruction signal for operating hydraulic excavator 1, it is possible to reliably acquire the initial snapshot data when a failure first occurs after the start of hydraulic excavator 1.

As illustrated in FIG. 12, the initial snapshot data is stored in storage unit 50F, by which when it is difficult to identify the failure of the component based on only the running snapshot data, it is possible to read the stored initial snapshot data and identify the failure of the component based on the initial snapshot data.

As illustrated in FIG. 12, since the countermeasure against the identified failure is output, the operator, the repair worker, or the like can quickly execute the countermeasure against the failure with reference to the output.

As illustrated in FIG. 12, in a case where there is a plurality of countermeasures against a failure, the countermeasures are output with priority, so that the operator, the repair worker, or the like can efficiently execute the countermeasures against the failure with reference to the output.

Second Embodiment

In the first embodiment, the example has been described in which controller 50 mounted on the work machine identifies the failure of the component based on the snapshot data. The present invention is not limited to this example, but a controller outside the work machine may identify a failure of a component. FIG. 14 is a block diagram illustrating a system configuration according to a second embodiment.

As illustrated in FIG. 14, detection units 60 described in the first embodiment are mounted on hydraulic excavator 1. Controller 50 acquires the physical quantities detected by detection units 60. Excavator 1 includes a communication unit 56. Communication unit 56 has a communication function such as, for example, wireless communication.

A remote operation apparatus 70 is installed outside hydraulic excavator 1. Remote operation apparatus 70 has an operation apparatus (not illustrated) operated by the operator to operate hydraulic excavator 1. At a remote place away from a site where hydraulic excavator 1 works, the operator operates remote operation apparatus 70 to perform work using hydraulic excavator 1.

Communication unit 56 of hydraulic excavator 1 transmits the physical quantities detected by detection units 60 to remote operation apparatus 70. Controller 50 mounted on hydraulic excavator 1 may generate the time-series data of the physical quantities, that is, the snapshot data, and in this case, communication unit 56 transmits the snapshot data to remote operation apparatus 70.

Remote operation apparatus 70 includes a failure diagnostic controller 71, a failure cause database 72, a monitor 74, and a communication unit 76. Communication unit 76 receives the information transmitted by communication unit 56 of hydraulic excavator 1. Communication unit 76 inputs the received information on the physical quantities to failure diagnostic controller 71.

Similarly to failure cause database 50FDB described in the first embodiment, failure cause database 72 illustrated in FIG. 14 includes information in which a deviation of the physical quantity from the normal range and a failure of a component that is a cause of the deviation are associated with each other.

Failure diagnostic controller 71 receives the input of the physical quantities received by communication unit 76 and generates the snapshot data of the physical quantities. When the snapshot data generated by controller 50 of hydraulic excavator 1 is transmitted to communication unit 76, failure diagnostic controller 71 receives the input of the snapshot data. Failure diagnostic controller 71 reads failure cause database 72, and identifies one or a plurality of failures of the components that cause deviation of a specific physical quantity when the specific physical quantity deviates from the normal range based on the snapshot data and failure cause database 72 as in the first embodiment.

Failure diagnostic controller 71 transmits a signal for displaying the identified failure of the component and the countermeasure against the failure to monitor 74. The operator operating remote operation apparatus 70 can recognize the failure of the component and the countermeasure against the failure by viewing display on monitor 74. Since the failure of the component and the countermeasure against the failure can be accurately grasped at a remote place away from a site where hydraulic excavator 1 works, it is possible to quickly recover from the failure by quickly executing the countermeasure.

Third Embodiment

FIG. 15 is a block diagram illustrating a system configuration according to a third embodiment. Similarly to the first embodiment, hydraulic excavator 1 according to the third embodiment is designed to be operated by the operator who has boarded in cab 7, and includes operation apparatus 52, controller 50, and detection units 60. Controller 50 generates the snapshot data and identifies a failure of a component based on the initial snapshot data. Excavator 1 also includes communication unit 56 described in the second embodiment.

Excavator 1 is connected to a remote monitoring apparatus 90 and a mobile terminal 100 via a network 80.

Remote monitoring apparatus 90 is installed outside hydraulic excavator 1, and monitors an operation status of hydraulic excavator 1, a work status by hydraulic excavator 1, and the like from a remote place. Remote monitoring apparatus 90 includes a server 91, a monitor 94, and a communication unit 96. An inspector or the repair worker of hydraulic excavator 1 possesses mobile terminal 100. Mobile terminal 100 may be, for example, a smartphone, a tablet PC, or the like.

Communication unit 56 of hydraulic excavator 1 transmits an identified failure of a component and a countermeasure against the failure to remote monitoring apparatus 90 and mobile terminal 100 via network 80. Remote monitoring apparatus 90 causes server 91 to process the failure of the component and the countermeasure against the failure of the component received by communication unit 96, and displays the processed failure of the component and the countermeasure on monitor 94. Mobile terminal 100 displays the received failure of the component and the countermeasure on a screen.

The operator who monitors the operation status of hydraulic excavator 1 with reference to remote monitoring apparatus 90 at a remote place can recognize the failure of the component and the countermeasure against the failure by viewing the display of monitor 74. Each of the inspector and the repair worker who possess mobile terminal 100 can recognize the failure of the component and the countermeasure against the failure by viewing the display of the screen of mobile terminal 100. It is possible to quickly recover from the failure by accurately grasping the failure of the component and the countermeasure against the failure and quickly executing the countermeasure.

In the description of the embodiments so far, hydraulic excavator 1 has been described as one example of the work machine, but the idea of the present disclosure may be applied to other types of work machines, for example, a crawler dozer, a wheel loader, a dump truck, and the like.

It should be considered that the embodiments disclosed this time are examples in all respects and are not restrictive. The scope of the present invention is defined not by the description above but by the claims, and it is intended that all modifications within meaning and scope equivalent to the claims are included.

REFERENCE SIGNS LIST

• • 1: hydraulic excavator, 2: traveling body, 3: swing body, 4: work implement, 5: engine compartment, 7: cab, 10: engine, 11, 12: output shaft, 14: injection pump, 16: cooling fan, 18: fan clutch, 20: cooling water circulation path, 21: cooling water piping, 21A: water jacket, 22: cooling water pump, 24: thermostat, 26: radiator, 28: reservoir tank, 30: hydraulic oil circulation path, 31: hydraulic oil piping, 32: hydraulic oil pump, 34: main valve, 36: oil cooler, 37: bypass valve, 38: hydraulic oil tank, 40: hydraulic actuator, 50: controller, 50A: operation control unit, 50B: physical quantity acquisition unit, 50C: state determination unit, 50D: snapshot data acquisition unit, 50E: arithmetic processing unit, 50F: storage unit, 50FDB, 72: failure cause database, 52: operation apparatus, 54, 74, 94: monitor, 56, 76, 96: communication unit, 60: detection unit, 61: water temperature sensor, 62: oil temperature sensor, 63: fan rotational number sensor, 64: water level sensor, 65: fuel injection amount sensor, 66: engine rotational number sensor, 67: outside air temperature sensor, 70: remote operation apparatus, 71: failure diagnostic controller, 80: network, 90: remote monitoring apparatus, 91: server, 100: mobile terminal

Claims

1. A failure diagnostic system for a work machine, comprising:

a component mounted on a work machine;

a detection unit that detects a predetermined physical quantity in order to monitor an operation status of the component;

a controller that acquires time-series data of the physical quantity detected in a predetermined period as snapshot data and determines whether or not the physical quantity detected by the detection unit is in a normal range; and

a storage unit that stores information in which a deviation of the physical quantity from the normal range and a failure of the component that is a cause of the deviation are associated with each other, wherein

the controller

acquires, as first snapshot data, the time-series data detected in a first period,

acquires, as second snapshot data, the time-series data detected in a second period after the first period, and

identifies the failure of the component based on the first snapshot data, the second snapshot data, and the information stored in the storage unit.

2. The failure diagnostic system for a work machine according to claim 1, wherein the controller

generates an instruction signal for operating the work machine, and

acquires time-series data of the physical quantity as the first snapshot data after the instruction signal is generated, the time-series data being detected in the predetermined period going back from a time point when it is first determined that the physical quantity deviates from the normal range.

3. The failure diagnostic system for a work machine according to claim 1, wherein the controller stores the first snapshot data in the storage unit.

4. The failure diagnostic system for a work machine according to claim 1, wherein

the information stored in the storage unit includes information in which the failure of the component and a countermeasure against the failure are associated with each other, and

the controller outputs the countermeasure against the failure identified based on the information stored in the storage unit.

5. The failure diagnostic system for a work machine according to claim 4, wherein when there is a plurality of countermeasures against the failure, the controller gives priority to the countermeasures and outputs the countermeasures.

6. A failure diagnostic method for a work machine, the work machine including a component, and a detection unit that detects a predetermined physical quantity in order to monitor an operation status of the component, wherein information in which a deviation of the physical quantity detected by the detection unit from a normal range and a failure of the component that is a cause of the deviation are associated with each other is stored in a storage unit, the failure diagnostic method including:

acquiring, as first snapshot data, time-series data of the physical quantity detected in a first period;

acquiring, as second snapshot data, the time-series data of the physical quantity detected in a second period after the first period; and

identifying the failure of the component based on the first snapshot data, the second snapshot data, and the information stored in the storage unit.