Diagnostic device for exhaust gas aftertreatment device, diagnostic method for exhaust gas aftertreatment device, and diagnostic program for exhaust gas aftertreatment device

Abstract

To provide a diagnosis device for an exhaust gas post-treatment device, a diagnosis method for the exhaust gas post-treatment device and a diagnosis program for the exhaust gas post-treatment device which can accurately detect a failure of the exhaust gas post-treatment device.SOLUTION: An exhaust gas post-treatment device includes: a temperature sensor 2 for detecting temperatures of a filter 11 on an inlet side and an outlet side thereof; a pressure difference sensor 3 for detecting a pressure difference between the inlet side and the outlet side of the filter 11; an intake pressure sensor 4 for detecting an intake pressure of an engine 51; and determination means for determining a failure of the exhaust gas post-treatment device 10 on the basis of values detected by the temperature sensor 2, the pressure difference sensor 3 and the intake pressure sensor 4, respectively.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an exhaust gas aftertreatment device diagnostic device, an exhaust gas aftertreatment device diagnostic method, and an exhaust gas aftertreatment device diagnostic program for diagnosing a malfunction in an exhaust gas aftertreatment device provided in a vehicle. [Background technology]

[0002] Patent Document 1 discloses a particulate filter failure diagnosis device that determines whether a particulate filter has failed based on the amount of PM (Particulate Matter) that has accumulated. The PM sensor detects the amount of PM that has accumulated from a change in electrical resistance between a pair of electrodes.

[0003] Furthermore, Patent Document 2 discloses a diagnostic device that provides a PM sensor with at least a pair of electrode members that form a capacitor in a filter member that is located downstream of a DPF (Diesel Particulate Filter), and determines whether the DPF has failed based on the electrostatic capacitance between the electrode members. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-48709 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-70077 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the PM sensor of Patent Document 1, large particles of PM adhere between the pair of electrodes, which inevitably causes a large change in output. Also, with Patent Document 2, a capacitor needs to be added, which requires modification of the DPF.

[0006] An object of the present invention is to provide an exhaust gas aftertreatment device diagnostic device, an exhaust gas aftertreatment device diagnostic method, and an exhaust gas aftertreatment device diagnostic program that are capable of detecting failures in exhaust gas aftertreatment devices with high accuracy. [Means for solving the problem]

[0007] The diagnostic device for exhaust gas aftertreatment devices of the present invention is a diagnostic device for exhaust gas aftertreatment devices that diagnoses failures in exhaust gas aftertreatment devices installed in a vehicle to capture particulates from engine exhaust gases, and is characterized in that the exhaust gas aftertreatment device has a filter that captures the particulates, and has a temperature detection device that detects the temperature on the inlet and outlet sides of the filter, a differential pressure detection device that detects the differential pressure between the inlet and outlet sides of the filter, an intake pressure detection device that detects the intake pressure of the engine, and a determination means that determines a failure of the exhaust gas aftertreatment device based on values ​​detected by each of the temperature detection device, the differential pressure detection device, and the intake pressure detection device.

[0008] In addition, the diagnostic method for an exhaust gas aftertreatment device according to the present invention is a diagnostic method for an exhaust gas aftertreatment device that diagnoses a malfunction of an exhaust gas aftertreatment device installed in a vehicle for collecting particulates from engine exhaust gas, wherein the exhaust gas aftertreatment device has a filter that collects the particulates, and is characterized in that it has a temperature detection step that detects the temperature on the inlet side and outlet side of the filter, a differential pressure detection step that detects the differential pressure between the inlet side and outlet side of the filter, an intake pressure detection step that detects the intake pressure of the engine, and a determination step that determines a malfunction of the exhaust gas aftertreatment device based on the values ​​detected in each of the temperature detection step, the differential pressure detection step, and the intake pressure detection step.

[0009] In addition, the diagnostic program for an exhaust gas aftertreatment device of the present invention is a diagnostic program for an exhaust gas aftertreatment device that causes a computer to function to diagnose a malfunction of an exhaust gas aftertreatment device installed in a vehicle for collecting particulates from engine exhaust gas, wherein the exhaust gas aftertreatment device has a filter for collecting the particulates, and is characterized in that the computer functions as a determination means for determining a malfunction of the exhaust gas aftertreatment device based on values ​​detected by each of the temperature detection means, the differential pressure detection means, and the intake pressure detection means. [Effects of the Invention]

[0010] According to the present invention, a failure of an exhaust gas aftertreatment device is determined based on the temperatures on the inlet and outlet sides of the filter, the differential pressure between the inlet and outlet sides of the filter, and the intake pressure of the engine. The amount of particulate matter accumulated on the filter can be determined from the differential pressure between the inlet and outlet sides of the filter. The temperature state of the filter can be determined from the temperatures on the inlet and outlet sides of the filter. Therefore, by using the differential pressure between the inlet and outlet sides of the filter and the temperatures on the inlet and outlet sides of the filter for determination, a failure of the exhaust gas aftertreatment device can be detected before the filter melts. Furthermore, unlike the PM sensor of Patent Document 1, the temperature detection device, differential pressure detection device, and intake pressure detection device do not change their outputs significantly. Therefore, a failure of the exhaust gas aftertreatment device can be detected with high accuracy. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a side view of a work machine. [Figure 2] FIG. 2 is a configuration diagram showing a hydraulic circuit of the work machine. [Figure 3] FIG. 1 is a configuration diagram of an exhaust gas aftertreatment device. [Figure 4] FIG. 2 is a configuration diagram showing an electrical circuit of the work machine. [Figure 5]10 is a flowchart of a diagnostic process. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0013] (Work machine configuration) A diagnostic device (diagnostic device) for an exhaust gas aftertreatment device according to an embodiment of the present invention diagnoses a malfunction in an exhaust gas aftertreatment device provided on a vehicle. As shown in FIG. 1, which is a side view of a work machine 20, the diagnostic device 1 is provided on the work machine 20. The work machine 20 is an example of a vehicle, such as a hydraulic excavator. The work machine 20 may be operated by an operator in a cab (driver's compartment) 23, may be remotely operated, or may be automatically driven.

[0014] The work machine 20 has a machine body 25 equipped with a lower traveling body 21 and an upper rotating body 22 , an attachment 30 , and a cylinder 40 .

[0015] The lower traveling body 21 is a part that allows the work machine 20 to travel, and is equipped with, for example, left and right crawlers 26. The upper rotating body 22 is attached to the upper part of the lower traveling body 21 so as to be able to rotate via a rotating device 24. A cab (operator's compartment) 23 is provided at the front of the upper rotating body 22.

[0016] The attachment 30 is attached to the upper rotating body 22 so as to be rotatable in the vertical direction. The attachment 30 includes a boom 31, an arm 32, and a bucket 33. The boom 31 is attached to the upper rotating body 22 so as to be rotatable (raised and lowered) in the vertical direction. The arm 32 is attached to the boom 31 so as to be rotatable in the vertical direction. The bucket 33 is attached to the arm 32 so as to be rotatable in the front-to-rear direction. The bucket 33 is a tip attachment that is the tip of the attachment 30, and is a part that performs work such as digging, leveling, and scooping soil and sand. Note that the work object held by the bucket 33 is not limited to soil and sand, and may be stone or waste (industrial waste, etc.). Furthermore, the tip attachment is not limited to the bucket 33, and may be a grapple, a lifting magnet, etc.

[0017] The cylinder 40 is capable of hydraulically rotating the attachment 30. The cylinder 40 is a hydraulic telescopic cylinder. The cylinder 40 includes a boom cylinder 41, an arm cylinder 42, and a bucket cylinder 43.

[0018] The boom cylinder 41 rotates the boom 31 relative to the upper rotating body 22. A base end of the boom cylinder 41 is rotatably attached to the upper rotating body 22. A tip end of the boom cylinder 41 is rotatably attached to the boom 31.

[0019] The arm cylinder 42 rotates the arm 32 relative to the boom 31. A base end of the arm cylinder 42 is rotatably attached to the boom 31. A tip end of the arm cylinder 42 is rotatably attached to the arm 32.

[0020] The bucket cylinder 43 rotates the bucket 33 relative to the arm 32. A base end of the bucket cylinder 43 is rotatably attached to the arm 32. A tip end of the bucket cylinder 43 is rotatably attached to a link member 34 that is rotatably attached to the bucket 33.

[0021] (Configuration of hydraulic circuit of work machine) As shown in Figure 2, which is a configuration diagram showing the hydraulic circuit of the work machine 20, the work machine 20 has an engine 51, a hydraulic pump 52, and a control valve group 53. The engine 51 is the power source of the work machine 20. The hydraulic pump 52 is driven by the engine 51. The hydraulic pump 52 has a left hydraulic pump 52L and a right hydraulic pump 52R. The control valve group 53 changes the flow rate of hydraulic oil supplied from the hydraulic pump 52 to the cylinder 40, etc. The control valve group 53 has a left control valve group 53L and a right control valve group 53R.

[0022] The left hydraulic pump 52L supplies hydraulic oil to the left traveling motor 54L, the swing motor 55, and the arm cylinder 42. The right hydraulic pump 52R supplies hydraulic oil to the right traveling motor 54R, the boom cylinder 41, and the bucket cylinder 43. Note that these are merely examples and are not limiting. The left traveling motor 54L drives the left crawler 26 of the lower traveling body 21, and the right traveling motor 54R drives the right crawler 26 of the lower traveling body 21. The swing motor 55 is provided in the swing device 24 and swings the upper swing body 22.

[0023] The left control valve group 53L includes a control valve that changes the flow rate of hydraulic oil supplied to the left traveling motor 54L, a control valve that changes the flow rate of hydraulic oil supplied to the swing motor 55, and a control valve that changes the flow rate of hydraulic oil supplied to the arm cylinder 42. The right control valve group 53R includes a control valve that changes the flow rate of hydraulic oil supplied to the right traveling motor 54R, a control valve that changes the flow rate of hydraulic oil supplied to the boom cylinder 41, and a control valve that changes the flow rate of hydraulic oil supplied to the bucket cylinder 43. These control valves are controlled by an operating lever (operating device) 28 (see FIG. 1) provided inside the cab 23. Note that a plurality of operating levers 28 are provided inside the cab 23.

[0024] The engine 51, the hydraulic pump 52, and the control valve group 53 are controlled by a controller 71, which will be described later.

[0025] As shown in Fig. 1, the left and right crawlers 26, the upper rotating body 22, and the attachment 30 are the moving parts of the work machine 20. The operating lever 28 outputs operation commands for operating the moving parts. As shown in Fig. 2, the engine 51, the hydraulic pump 52, and the control valve group 53 are the power sources that supply power to the moving parts.

[0026] (Configuration of exhaust gas aftertreatment device) As shown in Figure 3, which is a configuration diagram of the exhaust gas after-treatment device 10, the work machine 20 has the exhaust gas after-treatment device 10. The exhaust gas after-treatment device 10 is provided in an exhaust pipe 15 through which exhaust gas from the engine 51 passes, and captures particulates from the exhaust gas. The exhaust gas after-treatment device 10 has a filter 11 that captures particulates, and an oxidation catalyst 12 that is provided upstream of the filter 11 and oxidizes unburned fuel.

[0027] The diagnostic device 1 has a temperature sensor (temperature detection device) 2, a differential pressure sensor (differential pressure detection device) 3, and an intake pressure sensor (intake pressure detection device) 4. The temperature sensor 2 detects the temperatures on the inlet and outlet sides of the filter 11. The differential pressure sensor 3 detects the differential pressure between the inlet and outlet sides of the filter 11. Here, the inlet side of the filter 11 means the inlet of the filter 11, or a position upstream of the inlet of the filter 11 near the inlet, etc. The same applies to the outlet side of the filter 11. The intake pressure sensor 4 is provided in an intake pipe 16 that supplies air to the engine 51, and detects the intake pressure (boost pressure) of the engine 51.

[0028] (Configuration of electrical circuits of work machines) As shown in FIG. 4, which is a configuration diagram of the electrical circuit of the work machine 20, the work machine 20 has a controller 71, a storage device 73, and a communication device 74.

[0029] The controller 71 is a computer that inputs and outputs signals, performs calculations (processing), stores information, etc. For example, the functions of the controller 71 are realized by a calculation unit (not shown) executing a program stored in a memory unit (not shown) of the controller 71. The controller 71 may be provided in only one location, or in multiple locations. The controller 71 may be mounted on the work machine 20, or may be located on a server or the like located outside the work machine 20.

[0030] The temperature value detected by the temperature sensor 2 is input to the controller 71. The temperature value is treated as an absolute temperature in the controller 71. The differential pressure value detected by the differential pressure sensor 3 is also input to the controller 71. The pressure value detected by the intake pressure sensor 4 is also input to the controller 71. The controller 71 periodically acquires the temperature value detected by the temperature sensor 2, the differential pressure value detected by the differential pressure sensor 3, and the pressure value detected by the intake pressure sensor 4.

[0031] Furthermore, the controller 71 receives an operation command from the operation lever 28 .

[0032] The communication device 74 communicates with a server or the like external to the work machine 20 .

[0033] The controller (determination means) 71 determines whether the exhaust gas aftertreatment device 10 has failed based on the values ​​detected by the temperature sensor 2, the differential pressure sensor 3, and the intake pressure sensor 4. Specifically, an index is set based on a value that is based on the ratio of the temperature on the inlet side of the filter 11 to the temperature on the outlet side of the filter 11, and the ratio of the differential pressure between the inlet side and the outlet side of the filter 11 to the intake pressure of the engine 51. If this index exceeds a threshold value, the controller determines that the exhaust gas aftertreatment device 10 has failed.

[0034] Here, the index can be expressed as a / b, where a is the temperature on the outlet side of the filter 11 divided by the temperature on the inlet side of the filter 11, and b is the pressure difference between the inlet and outlet sides of the filter 11 divided by the intake pressure of the engine 51.

[0035] When the filter 11 becomes clogged, the ratio of the differential pressure to the intake pressure of the engine 51 in the exhaust gas aftertreatment device 10 becomes larger than that in normal times, and the value of b becomes larger. When the filter 11 becomes clogged, a large amount of particulate matter accumulates on the filter 11, and burning the particulate matter in this state may cause the filter 11 to melt. On the other hand, when the value of b becomes large, the index a / b falls below the lower limit (threshold value) in normal times. Therefore, the controller 71 (notification means) can detect a malfunction of the exhaust gas aftertreatment device 10 before the filter 11 melts by detecting that the index falls below the lower limit.

[0036] Furthermore, the higher the temperature of the filter 11, the larger the value of a, which is the ratio between the temperature on the inlet side of the filter 11 and the temperature on the outlet side of the filter 11. If the temperature of the filter 11 becomes too high, there is a risk that the filter 11 will melt. On the other hand, if the value of a becomes large, the index a / b will exceed the upper limit (threshold) under normal conditions. Therefore, the controller 71 (notification means) can detect a malfunction of the exhaust gas aftertreatment device 10 before the filter 11 melts by detecting that the index exceeds the upper limit.

[0037] The index may be multiplied by a coefficient learned from past data. For example, the index may be obtained by multiplying a coefficient f(t) that changes with time t by a numerical value g(a / b) that includes a / b. f(t)=t, g(a / b)=(a / b) 2 If so, the index will grow over time.

[0038] The values ​​a and b in the index may be weighted. For example, the value a may be weighted more heavily than the value b. The product a*b of a and b may also be used as the index. In this case, an upper limit (threshold) of the index under normal conditions is set taking into consideration that the value b increases when the filter 11 is clogged and the value a increases when the filter 11 is at a high temperature. Then, the controller 71 (notification means) can detect a malfunction of the exhaust gas aftertreatment device 10 by detecting that the index exceeds the upper limit (threshold) before the filter 11 melts.

[0039] As described above, a failure of the exhaust gas aftertreatment device 10 is determined based on the temperatures of the inlet and outlet sides of the filter 11, the differential pressure between the inlet and outlet sides of the filter 11, and the intake pressure of the engine 51. The amount of particulate matter accumulated on the filter 11 can be determined from the differential pressure between the inlet and outlet sides of the filter 11. The temperature state of the filter 11 can be determined from the temperatures of the inlet and outlet sides of the filter 11. Therefore, by using the differential pressure between the inlet and outlet sides of the filter 11 and the temperatures of the inlet and outlet sides of the filter 11 for determination, a failure of the exhaust gas aftertreatment device 10 can be detected before the filter 11 melts. Furthermore, unlike the PM sensor of Patent Document 1, the outputs of the temperature sensor 2, the differential pressure sensor 3, and the intake pressure sensor 4 do not change significantly. Therefore, a failure of the exhaust gas aftertreatment device 10 can be detected with high accuracy.

[0040] Furthermore, a failure of the exhaust gas aftertreatment device 10 is determined based on an index that is a value obtained by multiplying the ratio of the temperature on the inlet side of the filter 11 to the temperature on the outlet side of the filter 11 by the ratio of the differential pressure between the inlet and outlet sides of the filter 11 to the intake pressure of the engine 51. Because such an index is dimensionless, failure of the exhaust gas aftertreatment device 10 can be detected with high accuracy by using this index, regardless of the type of work machine 20.

[0041] Here, when the controller (notification means) 71 determines that the exhaust gas aftertreatment device 10 has failed, it notifies that fact. When a notification to that effect is sent inside the work machine 20 by an alarm device provided in the work machine 20, the operator operating the work machine 20 can be notified that the exhaust gas aftertreatment device 10 has failed. The alarm device is, for example, a speaker or display provided in the cab 23 of the work machine 20. Also, a message that the exhaust gas aftertreatment device 10 has failed may be sent via the communication device 74 to a server or the like located outside the work machine 20. In this case, it is possible to notify a person outside the work machine 20 that the exhaust gas aftertreatment device 10 has failed. Therefore, for example, when the work machine 20 is operating automatically, it is possible to operate the work machine 20 to stop operation. Also, a message that the exhaust gas aftertreatment device 10 has failed may be sent to a terminal device for remotely operating the work machine 20. In this case, it is possible to notify a remote operator operating the work machine remotely that the exhaust gas aftertreatment device 10 has failed. In this way, it is possible to prevent the work machine 20 from continuing to operate in a situation where the filter 11 is likely to melt and be damaged.

[0042] Furthermore, when the controller (limiting means) 71 determines that the exhaust gas aftertreatment device 10 has failed, it limits the output of the power source within a predetermined range. Specifically, it limits the output of one or more of the engine 51, the hydraulic pump 52, and the control valve group 53 within the predetermined range.

[0043] When the upper limit of the output of the power source is limited, it is possible to suppress melting damage to the filter 11. Furthermore, when the lower limit of the output of the power source is limited and the load on the engine 51 is increased, it is possible to assist the regeneration process of the exhaust gas aftertreatment device 10. Here, the regeneration process is a process in which the load on the engine 51 is increased to heat the filter 11, thereby burning the particulates deposited on the filter 11.

[0044] Furthermore, the controller (accumulated time calculation means) 71 calculates the accumulated time during which the operating lever 28 has output an operation command while the controller itself is limiting the output of the power source. The controller 71 stores this accumulated time in the memory device 73. This makes it possible to determine how long the moving parts have been operating while the exhaust gas aftertreatment device 10 has been determined to have failed and the output of the power source is limited. Then, for example, when the engine 51 is stopped, the controller 71 transmits the accumulated time stored in the memory device 73 to the outside via the communication device 74.

[0045] Furthermore, the controller (security processing means) 71 performs information security processing on at least one of the values ​​detected by the temperature sensor 2, the differential pressure sensor 3, and the intake pressure sensor 4. Specifically, at least one of the temperature sensor 2, the differential pressure sensor 3, and the intake pressure sensor 4 attaches a signature to the detected value transmitted to the controller 71. The controller 71 verifies the signature, and if the verification is successful, calculates an index based on the detected value to which the signature is attached. By having the controller 71 verify the signature attached to the detected value transmitted to the controller 71, it is possible to detect tampering with the detected value, confirm the sender, and prevent spoofing. This ensures the security of the detected value. Note that a server or the like external to the work machine 20 may verify the signature. Furthermore, it is desirable that the controller 71 itself be implemented in a tamper-resistant area. For example, it is desirable that the controller 71 be housed in a housing to make it difficult to remove unauthorizedly, or that unauthorized removal of the controller 71 from the housing be detectable.

[0046] At least one of the temperature sensor 2, the differential pressure sensor 3, and the intake pressure sensor 4 may encrypt the detection value to be transmitted to the controller 71. The encryption may be performed using either a public key cryptosystem or a common key cryptosystem. The controller 71 decrypts the encrypted detection value, and if the decryption is successful, calculates an index based on the decrypted detection value. By having the controller 71 decrypt the encrypted detection value transmitted to the controller 71, a high level of confidentiality can be maintained. This ensures the security of the detection value. A server or the like external to the work machine 20 may decrypt the detection value. It is also desirable for the controller 71 to store the encrypted detection value in a tamper-resistant area (such as a chip that is tamper-resistant to unauthorized access).

[0047] (Operation of diagnostic equipment) Next, the operation of the diagnostic device 1 will be described with reference to FIG. 5, which is a flowchart of the diagnostic process.

[0048] First, the controller 71 activates the temperature sensor 2, the differential pressure sensor 3, and the intake pressure sensor 4 (step S1). Next, the controller 71 calculates an index based on the respective detected values ​​of the temperature sensor 2, the differential pressure sensor 3, and the intake pressure sensor 4 (step S2). Specifically, the controller 71 detects the temperatures of the inlet and outlet sides of the filter 11 based on the value detected by the temperature sensor 2 (temperature detection step), detects the differential pressure between the inlet and outlet sides of the filter 11 based on the value detected by the differential pressure sensor 3 (differential pressure detection step), and detects the intake pressure of the engine 51 based on the value detected by the intake pressure sensor 4 (intake pressure detection step), thereby calculating the index.

[0049] Next, the controller 71 determines whether the exhaust gas aftertreatment device 10 is in a malfunctioning state (abnormal state) (step S3) (determination step). If it is determined in step S3 that the exhaust gas aftertreatment device 10 is not in an abnormal state (S3: NO), the controller 71 returns to step S2. On the other hand, if it is determined in step S3 that the exhaust gas aftertreatment device 10 is in an abnormal state (S3: YES), the controller 71 notifies the user of this fact (step S4). Then, the controller 71 limits the output of the power source to within a predetermined range (step S5), and ends this flow.

[0050] (effect) As described above, the diagnostic device 1 according to this embodiment determines whether or not the exhaust gas aftertreatment device 10 has malfunctioned based on the temperatures of the inlet and outlet sides of the filter 11, the pressure difference between the inlet and outlet sides of the filter 11, and the intake pressure of the engine 51. The amount of particulate matter accumulated on the filter 11 can be determined from the pressure difference between the inlet and outlet sides of the filter 11. The temperature state of the filter 11 can be determined from the temperatures of the inlet and outlet sides of the filter 11. Therefore, by using the pressure difference between the inlet and outlet sides of the filter 11 and the temperatures of the inlet and outlet sides of the filter 11 for determination, it is possible to detect a malfunction of the exhaust gas aftertreatment device 10 before the filter 11 melts. Furthermore, unlike the PM sensor of Patent Document 1, the outputs of the temperature sensor 2, the differential pressure sensor 3, and the intake pressure sensor 4 do not change significantly. Therefore, it is possible to detect a malfunction of the exhaust gas aftertreatment device 10 with high accuracy.

[0051] Furthermore, a failure of the exhaust gas aftertreatment device 10 is determined based on an index that is a value obtained by multiplying the ratio of the temperature on the inlet side of the filter 11 to the temperature on the outlet side of the filter 11 by the ratio of the differential pressure between the inlet and outlet sides of the filter 11 to the intake pressure of the engine 51. Because such an index is dimensionless, failure of the exhaust gas aftertreatment device 10 can be detected with high accuracy by using this index, regardless of the type of work machine 20.

[0052] Furthermore, if it is determined that the exhaust gas aftertreatment device 10 has failed, a notification to that effect is sent. For example, if a notification is sent inside the work machine 20, the operator operating the work machine 20 can be notified that the exhaust gas aftertreatment device 10 has failed. Furthermore, if a notification is sent outside the work machine 20 via the communication device 74, a person outside the work machine 20 can be notified that the exhaust gas aftertreatment device 10 has failed. Therefore, for example, if the work machine 20 is operating automatically, the work machine 20 can be operated to stop operation. Furthermore, if a notification that the exhaust gas aftertreatment device 10 has failed is sent to a terminal device for remotely operating the work machine 20, the remote operator operating the work machine can be notified that the exhaust gas aftertreatment device 10 has failed. Therefore, it is possible to prevent the work machine 20 from continuing to operate in a situation where the filter 11 is likely to melt.

[0053] Furthermore, if it is determined that the exhaust gas aftertreatment device 10 has failed, the output of the power source is limited within a predetermined range. If the upper limit of the output of the power source is limited, it is possible to suppress melting damage to the filter 11. Furthermore, if the lower limit of the output of the power source is limited and the load on the engine 51 is increased, it is possible to assist the regeneration process of the exhaust gas aftertreatment device 10.

[0054] In addition, the accumulated time during which the operating lever 28 has output an operation command while the output of the power source is limited is calculated. This allows the system to determine how long the moving parts have been operating while the exhaust gas aftertreatment device 10 has been determined to have failed and the output of the power source is limited.

[0055] Furthermore, information security processing is performed on at least one of the values ​​detected by the temperature sensor 2, the differential pressure sensor 3, and the intake pressure sensor 4. For example, information security can be ensured by detecting tampering with the detected value or encrypting the detected value.

[0056] Although the embodiments of the present invention have been described above, they are merely illustrative examples and do not limit the present invention, and the specific configurations and other aspects can be appropriately modified in design. Furthermore, the actions and effects described in the embodiments of the invention are merely a list of the most preferred actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to those described in the embodiments of the present invention. [Explanation of symbols]

[0057] 1 Diagnostic equipment 2 Temperature sensor (temperature detection device) 3 Differential pressure sensor (differential pressure detection device) 4. Intake pressure sensor (intake pressure detection device) 10 Exhaust gas aftertreatment device 11 Filters 12 Oxidation catalyst 15 exhaust pipe 16 Intake pipe 20 Work Machinery 21 Undercarriage 22 Upper rotating body (movable part) 23 Cab 24 Swivel 25 Machine body 26 Crawler (moving part) 28 Operating lever (operating device) 30 Attachment (movable part) 31 Boom 32 Arm 33 Bucket 34 Link member 40 cylinders 41 Boom cylinder 42 Arm cylinder 43 Bucket cylinder 51 Engine (power source) 52 Hydraulic pump (power source) 53 Control valve group (power source) 54L Left drive motor 54R Right travel motor 55 Swing motor 71 Controller (determination means, notification means, restriction means, cumulative time calculation means, security processing means) 73 Storage device 74 Communication Equipment

Claims

1. 1. A diagnostic device for an exhaust gas aftertreatment device that diagnoses a malfunction of an exhaust gas aftertreatment device provided in a vehicle for capturing particulates from engine exhaust gas, comprising: the exhaust gas aftertreatment device has a filter that collects the particulates, a temperature detection device for detecting the temperatures of the inlet and outlet sides of the filter; a differential pressure detection device for detecting a differential pressure between an inlet side and an outlet side of the filter; an intake pressure detection device for detecting an intake pressure of the engine; a determination means for calculating an index that can be expressed using the temperatures of the inlet side and the outlet side of the filter detected by the temperature detection device, the differential pressure detected by the differential pressure detection device, and the intake pressure detected by the intake pressure detection device, and determining a failure of the exhaust gas aftertreatment device based on the index; A diagnostic device for an exhaust gas aftertreatment device, comprising:

2. A diagnostic device for an exhaust gas aftertreatment device that diagnoses a malfunction of an exhaust gas aftertreatment device provided on a vehicle to capture particulates from engine exhaust gas, comprising: the exhaust gas aftertreatment device has a filter that collects the particulates, a temperature detection device for detecting the temperatures of the inlet and outlet sides of the filter; a differential pressure detection device for detecting a differential pressure between an inlet side and an outlet side of the filter; an intake pressure detection device for detecting an intake pressure of the engine; a determination means for determining a failure of the exhaust gas aftertreatment device based on values ​​detected by the temperature detection device, the differential pressure detection device, and the intake pressure detection device; and The determination means determines a failure of the exhaust gas aftertreatment device based on the index, A diagnostic device for an exhaust gas aftertreatment device, characterized in that the index is a value based on the ratio of the temperature on the inlet side of the filter to the temperature on the outlet side of the filter, and the ratio of the differential pressure between the inlet side and the outlet side of the filter to the intake pressure of the engine.

3. 3. The diagnostic device for an exhaust gas aftertreatment device according to claim 1, further comprising a notification means for notifying the user when the determination means determines that the exhaust gas aftertreatment device has failed.

4. the vehicle is a work machine, The work machine includes: A plurality of moving parts; a power source that supplies power to the movable part; and A diagnostic device for an exhaust gas aftertreatment device as described in any one of claims 1 to 3, characterized in that it has a limiting means for limiting the output of the power source within a predetermined range when the determining means determines that the exhaust gas aftertreatment device has failed.

5. an operating device that outputs an operation command to operate the movable part; an accumulated time calculation means for calculating an accumulated time during which the operation device has output the operation command in a state in which the limiting means limits the output of the power source; 5. The diagnostic device for an exhaust gas aftertreatment device according to claim 4, further comprising:

6. The diagnostic device for an exhaust gas aftertreatment device according to any one of claims 1 to 5, further comprising a security processing means for performing information security processing on at least one of the values ​​detected by the temperature detection device, the differential pressure detection device, and the intake pressure detection device.

7. 1. A diagnostic method for an exhaust gas aftertreatment device for diagnosing a failure in an exhaust gas aftertreatment device provided in a vehicle for capturing particulates from exhaust gas of an engine, comprising: the exhaust gas aftertreatment device has a filter that collects the particulates, a temperature detection step of detecting temperatures on the inlet side and the outlet side of the filter; a differential pressure detection step of detecting a differential pressure between an inlet side and an outlet side of the filter; an intake pressure detecting step of detecting an intake pressure of the engine; a determination step of calculating an index that can be expressed using the temperatures of the inlet side and the outlet side of the filter detected in the temperature detection step, the differential pressure detected in the differential pressure detection step, and the intake pressure detected in the intake pressure detection step, and determining a failure of the exhaust gas aftertreatment device based on the index; A diagnostic method for an exhaust gas aftertreatment device, comprising:

8. A diagnostic program for an exhaust gas aftertreatment device that causes a computer to function to diagnose a failure of an exhaust gas aftertreatment device provided in a vehicle for collecting particulate matter from engine exhaust gas, comprising: the exhaust gas aftertreatment device has a filter that collects the particulates, a temperature detection means for detecting the temperatures of the inlet and outlet sides of the filter; a differential pressure detection means for detecting a differential pressure between an inlet side and an outlet side of the filter; an intake pressure detecting means for detecting an intake pressure of the engine; A diagnostic program for an exhaust gas aftertreatment device, characterized in that it calculates an index that can be expressed using the temperatures on the inlet and outlet sides of the filter detected by the temperature detection means, the differential pressure detected by the differential pressure detection means, and the intake pressure detected by the intake pressure detection means, and causes a computer to function as a judgment means for judging a malfunction of the exhaust gas aftertreatment device based on the index.

9. A diagnostic method for an exhaust gas aftertreatment device, which diagnoses a malfunction of an exhaust gas aftertreatment device provided on a vehicle for capturing particulates from engine exhaust gas, comprising: the exhaust gas aftertreatment device has a filter that collects the particulates, a temperature detection step of detecting temperatures on the inlet side and the outlet side of the filter; a differential pressure detection step of detecting a differential pressure between an inlet side and an outlet side of the filter; an intake pressure detecting step of detecting an intake pressure of the engine; a determination step of determining whether the exhaust gas aftertreatment device has failed based on the values ​​detected in the temperature detection step, the differential pressure detection step, and the intake pressure detection step; and The determination step determines a failure of the exhaust gas aftertreatment device based on an index, A diagnostic method for an exhaust gas aftertreatment device, characterized in that the index is a value based on the ratio of the temperature on the inlet side of the filter to the temperature on the outlet side of the filter, and the ratio of the pressure difference between the inlet side and the outlet side of the filter to the intake pressure of the engine.

10. A diagnostic program for an exhaust gas aftertreatment device that causes a computer to function to diagnose a failure of an exhaust gas aftertreatment device provided on a vehicle for capturing particulates from engine exhaust gas, comprising: the exhaust gas aftertreatment device has a filter that collects the particulates, a temperature detection means for detecting the temperatures of the inlet and outlet sides of the filter; a differential pressure detection means for detecting a differential pressure between an inlet side and an outlet side of the filter; an intake pressure detecting means for detecting an intake pressure of the engine; causing a computer to function as a determination means for determining a failure of the exhaust gas aftertreatment device based on values ​​detected by the temperature detection means, the differential pressure detection means, and the intake pressure detection means; The determination means determines a failure of the exhaust gas aftertreatment device based on the index, A diagnostic program for an exhaust gas aftertreatment device, characterized in that the index is a value based on the ratio of the temperature on the inlet side of the filter to the temperature on the outlet side of the filter, and the ratio of the differential pressure between the inlet side and the outlet side of the filter to the intake pressure of the engine.

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