Engine abnormality prediction device

Abstract

To more appropriately predict abnormality of an engine.SOLUTION: A use state of a vehicle is determined on the basis of one of an engine speed which is a speed of an engine, an engine load factor which is a load factor of the engine, a vehicle speed, and an on / off state of a brake of the vehicle, and it is determined whether condensate water is generated in the engine or not on the basis of lapse time after stopping of the engine, and at condensate water generation time when the condensate water is generated in the engine or when an amount of the condensate water generated in the engine is equal to or more than a prescribed amount, engine abnormality is predicted on the basis of the determined use state of the vehicle.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an engine abnormality prediction device. [Background technology]

[0002] A conventional engine abnormality prediction device of this type estimates the amount of condensed water that accumulates in the exhaust pipe using the exhaust temperature, gas flow rate, and outside air temperature when the engine is started, and activates a heater to heat the exhaust gas sensor when it determines that the estimated amount of condensed water is equal to or less than a predetermined value (see, for example, Patent Document 1).In this device, when it determines that the amount of condensed water exceeds the predetermined value, the heater that heats the exhaust gas sensor is not activated, thereby suppressing the occurrence of an abnormality in the exhaust gas sensor caused by uneven temperature distribution in the exhaust gas sensor due to the activation of the heater. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-234574 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the engine abnormality prediction device described above does not take into account the vehicle usage conditions. Even if condensed water is generated in the engine, an abnormality may not occur depending on the vehicle usage conditions. Therefore, there is a need for a more accurate prediction of the occurrence of an engine abnormality.

[0005] The main object of the engine abnormality prediction device of the present invention is to more accurately predict the occurrence of an engine abnormality. [Means for solving the problem]

[0006] The engine abnormality prediction device of the present invention employs the following means to achieve the above-mentioned main object.

[0007] The engine abnormality prediction device of the present invention comprises: An engine abnormality prediction device for predicting an engine abnormality as an abnormality of an engine mounted on a vehicle, comprising: determining a usage state of the vehicle based on at least one of an engine rotation speed, which is a rotation speed of the engine, an engine load factor, which is a load factor of the engine, a vehicle speed of the vehicle, and an on / off state of a brake of the vehicle; determining whether condensed water has occurred in the engine based on the elapsed time since the engine was stopped; When condensed water is generated in the engine, or when the amount of condensed water generated in the engine is equal to or greater than a predetermined amount, the engine abnormality is predicted based on the determined usage state of the vehicle. The gist of this is as follows.

[0008] The engine abnormality prediction device of the present invention determines the vehicle usage state based on at least one of the engine speed, engine load factor, vehicle speed, and vehicle brake on / off state. It also determines whether condensed water has formed in the engine based on the time elapsed since the engine was stopped. When condensed water has formed in the engine, or when the amount of condensed water formed in the engine is equal to or greater than a predetermined amount, an engine abnormality is predicted based on the determined vehicle usage state. Because the vehicle usage state is taken into consideration, engine abnormality can be predicted more accurately. Here, the "predetermined amount of water" can be a water amount threshold for determining whether the amount of condensed water is large enough to cause an engine abnormality.

[0009] In the engine abnormality prediction device of the present invention, the operating state of the engine may be determined as the usage state of the vehicle based on operating points consisting of the engine speed and the engine load factor when the engine was operated in the past. In this way, the operating state of the engine is taken into consideration, making it possible to more accurately predict the occurrence of an engine abnormality.

[0010] In the engine abnormality prediction device of the present invention, which determines the engine operating state as the vehicle usage state, cylinder corrosion of the engine may be predicted as the engine abnormality when the condensed water is generated and the engine is operating in a high-speed, high-load state where the engine is operated frequently at high speeds and a high load factor. This allows for more accurate prediction of an engine abnormality due to cylinder corrosion. In this case, when the condensed water is generated and the engine is operating in the high-speed, high-load state, and the engine coolant temperature at engine start is below a predetermined water temperature, cylinder corrosion may be predicted as the engine abnormality. This allows for more accurate prediction of an abnormality due to cylinder corrosion when the engine coolant temperature at engine start is equal to or higher than the predetermined water temperature and the condensed water generated in the engine has evaporated. Here, the "predetermined temperature" may be, for example, a temperature threshold value for determining whether the engine has warmed up. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing an outline of the configuration of an automobile 20 equipped with an engine device according to an embodiment of the present invention. [Figure 2] FIG. 10 is an explanatory diagram for explaining an example of regions α, β, γ, and δ. [Figure 3] 4 is a flowchart showing an example of a processing routine executed by an ECU 70. [Figure 4] 3 is an explanatory diagram showing an example of a change in temperature Tp of components constituting the engine 22 over time. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Next, a mode for carrying out the present invention will be described using examples. [Example]

[0013] 1 is a diagram showing an outline of the configuration of an automobile 20 equipped with an engine abnormality prediction device according to one embodiment of the present invention. As shown in the figure, the automobile 20 of the embodiment includes an engine 22, an EGR device 150, a transmission 60 that changes the speed of the power of the engine 22 and transmits it to drive wheels 64a, 64b via a differential gear 62, and an electronic control unit (hereinafter referred to as "ECU") 70. In the embodiment, the ECU 70 corresponds to the "engine abnormality prediction device."

[0014] The engine 22 is an internal combustion engine that uses gasoline as fuel to generate power. The engine 22 draws air through an intake port 52 into an air cleaner 23, then passes the cleaned air through an intake pipe 24. It also injects gasoline through a fuel injection valve 26. The air-fuel mixture is drawn into a combustion chamber via an intake valve 28, where it is explosively combusted by an electric spark from a spark plug 30. The resulting energy pushes down a piston 32, which then converts the reciprocating motion of the piston 32 into rotational motion of a crankshaft 33. Exhaust gas from the combustion chamber is discharged into the outside air via a purification device 34, which includes a purification catalyst (three-way catalyst) that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). In addition to being discharged into the outside air, exhaust gas and unburned gas generated in the combustion chamber also flow into the space within the crankcase 31 through the gap between the piston 32 and the cylinder 37 (hereinafter, the exhaust gas and unburned gas thus discharged are referred to as "blow-by gas"). An oil pan at the bottom of the crankcase 31 stores engine oil.

[0015] The engine 22 is provided with a blow-by gas pipe 90 that connects the intake pipe 24 downstream of the throttle valve 25 with the crankcase 31. A blow-by valve 92 that allows blow-by gas to flow in one direction (from the crankcase 31 toward the intake pipe 24) is attached to the blow-by gas pipe 90, and the blow-by gas passes through the blow-by gas pipe 90 and is returned to the intake pipe 24. The operation of the engine 22 is controlled by the ECU 70.

[0016] The EGR device 150 includes an EGR pipe 152, an EGR valve 154, an EGR cooler 156, and a stepping motor (not shown). The EGR pipe 152 connects the exhaust pipe 35 downstream of the purification device 34 with the intake pipe 24. The EGR valve 154 is provided in the EGR pipe 152 and is driven by a stepping motor (not shown) controlled by the ECU 70. The EGR cooler 156 is provided in the EGR pipe 152 and cools the exhaust gas passing through the EGR pipe 152. The EGR device 150 adjusts the opening of the EGR valve 154 with the stepping motor, thereby adjusting the amount of exhaust gas recirculated from the exhaust pipe 35 and recirculating it to the intake pipe 24.

[0017] The ECU 70 is configured as a microprocessor centered around a CPU 72, and in addition to the CPU 72, includes a ROM 74 that stores processing programs, a RAM 76 that temporarily stores data, a flash memory 78 that stores data, and input / output ports (not shown). Signals from various sensors are input to the ECU 70 via the input ports.

[0018] Examples of signals input to ECU 70 include crank angle θcr from crank position sensor 40 that detects the rotational position of crankshaft 33, in-cylinder pressure from pressure sensor 43 attached to the combustion chamber, cam position from cam position sensor 44 that detects the rotational position of a camshaft that opens and closes intake valve 28 and exhaust valves that intake and exhaust air to and from the combustion chamber, and throttle opening TH from throttle valve position sensor 46 that detects the position of throttle valve 25. Other examples include air-fuel ratio AF from air-fuel ratio sensor 35a, an oxygen signal from oxygen sensor 35b, coolant temperature Tw from water temperature sensor 42 that detects the temperature of coolant for engine 22, intake air amount Qa from air flow meter 48 attached to intake pipe 24, intake air temperature from temperature sensor 49 attached to intake pipe 24, and intake port opening from a valve sensor that detects the opening of valve 56. Further examples include an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operating position of a shift lever 81, an accelerator opening Acc from an accelerator pedal position sensor 84 that detects the amount of depression of an accelerator pedal 83, a brake pedal position BP from a brake pedal position sensor 86 that detects the amount of depression of a brake pedal 85, and a vehicle speed V from a vehicle speed sensor 88.

[0019] The ECU 70 outputs, via an output port, various control signals for controlling the operation of the engine 22. Examples of signals output from the ECU 70 include a drive signal to the fuel injection valve 26, a drive signal to the throttle motor 36 that adjusts the position of the throttle valve 25, a control signal to the ignition coil 38 integrated with the igniter, and a control signal to the valve motor that adjusts the opening of the valve 56. The ECU 70 also outputs, via the output port, a control signal to the stepping motor of the EGR device 150 and a control signal to the transmission 60.

[0020] The ECU 70 calculates the rotation speed of the crankshaft 33, i.e., the rotation speed (engine rotation speed) Ne of the engine 22 at predetermined time intervals (for example, every few msec) based on the crank angle θcr from the crank position sensor 40. The ECU 70 also calculates a load factor KL (the ratio of the volume of air actually taken in one cycle to the stroke volume per cycle of the engine 22, i.e., the engine load factor) based on the calculated rotation speed Ne of the engine 22 and the intake air amount Qa from the air flow meter 48.

[0021] The ECU 70 stores the engine speed Ne and load factor KL of the engine 22 calculated at predetermined time intervals in the RAM 76. When the ignition switch 80 is turned off, the ECU 70 uses the engine speed Ne and load factor KL of the engine 22 for one trip (the period from when the ignition switch 80 is turned on to when it is turned off) stored in the RAM 76 to determine whether the driving point indicated by the engine speed Ne and load factor KL is within a high-speed, high-load region α, a low-speed, low-load region β, a low-speed, high-load region γ, or a high-speed, low-load region δ. FIG. 2 is an explanatory diagram illustrating an example of the regions α, β, γ, and δ. As shown in the figure, the regions α, β, γ, and δ are set so that they do not overlap each other on a map defined by the engine speed Ne and load factor KL of the engine 22. The ECU 70 calculates the proportions of driving points within the regions α, β, γ, and δ out of all driving points for one trip. When the proportion of driving points included in region α among all driving points of the trip is equal to or greater than a predetermined proportion Rαref, the type of the trip is set to a "region α heavy-use trip," and the total number of trips previously set to the "region α heavy-use trip" is stored in flash memory 78. When the proportion of driving points included in region β among all driving points of the trip is equal to or greater than a predetermined proportion Rβref, the type of the trip is set to a "region β heavy-use trip," and the total number of trips previously set to the "region β heavy-use trip" is stored in flash memory 78. When the proportion of driving points included in region γ among all driving points of the trip is equal to or greater than a predetermined proportion Rγref, the type of the trip is set to a "region γ heavy-use trip," and the total number of trips previously set to the "region γ heavy-use trip" is stored in flash memory 78. When the proportion of driving points included in region δ among all driving points of the trip is equal to or greater than a predetermined proportion Rδref, the type of the trip is set to "region δ-frequent trip," and the total number of trips previously set to "region δ-frequent trip" is stored in flash memory 78. The predetermined proportions Rαref, Rβref, Rγref, and Rδref may be the same or different proportions.

[0022] The ECU 70 stores the coolant temperature Tw detected by the water temperature sensor 42 when the ignition switch 80 is turned off as the off-time water temperature Twoff in the flash memory 78. The ECU 70 stores the date and time when the ignition switch 80 is turned off, which is set in the CPU 72, in the flash memory 78 as the off-time date and time Toff.

[0023] In the embodiment of the automobile 20 configured in this manner, the engine 22 and the transmission 60 are basically controlled so that the automobile travels while outputting from the engine 22 a required torque Te* (required power Pe*) that corresponds to the accelerator opening Acc from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88.

[0024] The operation control of the engine 22 includes intake air amount control, which controls the opening of the throttle valve 25, fuel injection control, which controls the amount of fuel injected from the fuel injection valve 26, and ignition control, which controls the ignition timing of the spark plug 30. In intake air amount control, the ECU 70 sets a target air amount Qa* based on the required torque Te* of the engine 22, sets a target throttle opening TH* so that the intake air amount Qa becomes the target air amount Qa*, and controls the throttle motor 36 so that the throttle opening TH of the throttle valve 25 becomes the target throttle opening TH*. In fuel injection control, the ECU 70 sets a target fuel injection amount Qf* based on the intake air amount Qa so that the air-fuel ratio AF becomes the target air-fuel ratio AF*, and controls the fuel injection valve 26 so that fuel is injected from the fuel injection valve 26 in the target fuel injection amount Qf*. In the ignition control, the ECU 70 sets a target ignition timing Tf* based on the rotation speed Ne and the load factor KL of the engine 22, and controls the spark plug 30 so that ignition occurs at the target ignition timing Tf*.

[0025] Next, the operation of the abnormality prediction device for the engine 22 mounted on the automobile 20 of this embodiment configured as described above will be described, particularly the operation when predicting an abnormality occurring on the inner surface of the cylinder 37. Figure 3 is a flowchart showing an example of a processing routine executed by the ECU 70. This routine is repeatedly executed after the ignition switch 80 is turned on.

[0026] 3 is executed, the CPU 72 of the ECU 70 first inputs data such as the engine speed Ne, load factor KL, off-time water temperature Twoff, and start-up water temperature Twst of the engine 22 (step S100). Here, the engine speed Ne is input as a value calculated based on the crank angle θcr from the crank position sensor 40. The load factor KL of the engine 22 is input as a value calculated based on the intake air amount Qa from the air flow meter 48 and the engine speed Ne of the engine 22. The off-time water temperature Twoff is input as stored in the flash memory 78. The start-up water temperature Twst is input as the cooling water temperature Tw detected by the water temperature sensor 42 when the engine 22 is started for the first time after the ignition switch 80 is turned on.

[0027] Next, the operating state Ste of the engine 22 is set based on the trip type (region α heavy use trip, region β heavy use trip, etc.) stored in the flash memory 78 that has the largest total number of trips (step S110). Here, when the number of region α heavy use trips is the largest, the operating state Ste of the engine 22 is set to the region α heavy use state (high rotation, high load heavy use state). When the number of region β heavy use trips is the largest, the operating state Ste of the engine 22 is set to the region β heavy use state (low rotation, low load heavy use state). When the number of region γ heavy use trips is the largest, the operating state Ste of the engine 22 is set to the region γ heavy use state (low rotation, high load heavy use state). When the number of region δ heavy use trips is the largest, the operating state Ste of the engine 22 is set to the region δ heavy use state (high rotation, high load heavy use state). The operating state Ste of the engine 22 thus set reflects the user's use of the automobile 20. For example, if the user frequently drives the automobile 20 in a sporty manner, the engine 22 will be operated at high speed and high load more frequently, which is considered to be a state in which the region α is frequently used.

[0028] Once the operating state Ste has been set in this manner, it is determined whether a large amount of condensed water is occurring in the engine 22 based on the off-state water temperature Twoff (step 120). FIG. 4 is an explanatory diagram showing an example of the change over time in the temperature Tp of a component constituting the engine 22. In the diagram, the solid line indicates the change over time in the temperature Tp of a component constituting the engine 22, and the dashed-dotted line indicates an example of the change over time in the outside air temperature. When the ignition switch 80 is turned on and the engine 22 starts operating (time t0), the temperature Tp rises. Then, when the warm-up of the engine 22 is completed (time t1), the components are cooled by a cooling system (not shown) of the engine 22, and the temperature Tp is maintained. When the ignition switch 80 is turned off (time t2), the temperature Tp gradually decreases, and when the temperature Tp falls below the dew-point temperature Ta, the gas in the cylinder 37 condenses, generating condensed water (time t3). The amount of condensed water increases when the temperature Tp remains below the dew-point temperature Ta for a long period of time compared to when it remains below the dew-point temperature Ta for a short period of time. In step S120, if the temperature Tp becomes equal to or lower than the dew-point temperature Ta after the ignition switch 80 is turned off and the time from when the temperature Tp becomes equal to or lower than the dew-point temperature Ta until the ignition switch 80 is turned on (at time t4) (the time from time t3 to time t4 in FIG. 4 ) is equal to or higher than a predetermined time tref, it is determined that a large amount of condensed water has formed in the cylinder 37. In this embodiment, since the detection value from the water temperature sensor 42 cannot be input to the ECU 70 when the ignition switch 80 is off, the temperature Tp is set using the off-state water temperature Twoff, the elapsed time toff since the ignition switch 80 was turned off, and the following equation (1). In equation (1), “a” and “n” are constants determined for each component through experiment, analysis, machine learning, or the like. The predetermined time tref is the time determined in advance through experiment, analysis, machine learning, or the like as the time at which the amount of condensed water exceeds a predetermined amount of water for determining whether corrosion of the cylinder 37 will occur.

[0029]

number

[0030] If it is determined in step S120 that a large amount of condensed water has not occurred in the engine 22, this routine is terminated. If it is determined in step S120 that a large amount of condensed water has occurred in the engine 22, it is then determined whether the operating state Ste is in the region α-frequent use state (step S130). When the operating state Ste is in the region α-frequent use state, that is, when the engine 22 is frequently operated at high speed and high load, operation with a high concentration of nitrogen oxides (NOx) is frequently performed. Therefore, when a large amount of condensed water has occurred in the engine 22, it is considered that the cylinder 37 is prone to corrosion. Therefore, step S130 is a process for determining whether the cylinder 37 is in a state in which it is prone to corrosion.

[0031] If the operating state Ste is not in the region α heavy use state in step S130, this routine is terminated. If the operating state Ste is in the region α heavy use state in step S130, it is determined whether the start-up water temperature Twst is equal to or lower than a predetermined water temperature Twref (step S140). The predetermined water temperature Twref is a threshold value for determining whether warming up of the engine 22 has been completed. Even if a large amount of condensed water is generated when the ignition switch 80 is off, it is considered that once warming up of the engine 22 is completed, the condensed water evaporates and the situation in which the inner surface of the cylinder 37 is susceptible to corrosion is resolved. Therefore, step S140 is a process for determining whether the situation in which the cylinder 37 is susceptible to corrosion has been resolved.

[0032] If it is determined in step S140 that the water temperature at startup Twst exceeds the predetermined water temperature Twref, the routine is terminated. If it is determined in step S140 that the water temperature at startup Twst is equal to or lower than the predetermined water temperature Twref, a prediction is made that an abnormality such as corrosion will occur on the inner surface of the cylinder 37 (step S140), and the routine is terminated. This processing makes it possible to predict the occurrence of an abnormality such as corrosion on the inner surface of the cylinder 37, i.e., an abnormality in the engine 22. When an abnormality such as corrosion on the inner surface of the cylinder 37 is predicted in this way, an alarm device that notifies information, such as a display in the vehicle cabin (not shown), may alert the user by displaying content such as "When you remove the spark flag when bringing the engine into warehousing, check the inner surface of the cylinder with a scope" or "Check for a sudden deterioration in the LOC."

[0033] According to the automobile 20 equipped with the abnormality prediction device for the engine 22 of the embodiment described above, the operating state Ste of the engine 22 (the usage state of the automobile 20) is determined based on the rotation speed Ne and the load factor KL of the engine 22, Elapsed time toff Whether or not condensed water is occurring in the engine 22 is determined based on the above, and when the amount of condensed water occurring in the engine 22 is equal to or greater than a predetermined amount (when condensed water is occurring), and when the starting water temperature Twst is equal to or lower than a predetermined water temperature Twref, an abnormality in the cylinder 37 (abnormality in the engine 22) is predicted, thereby making it possible to more accurately predict an abnormality in the engine 22.

[0034] In the automobile 20 equipped with the abnormality prediction device for the engine 22 of the embodiment, it is determined in step S120 whether the amount of condensed water is large, but it may be determined whether condensed water has been generated. Also, step S140 does not have to be executed.

[0035] In the automobile 20 equipped with the engine 22 abnormality prediction device of the embodiment, an example is shown in which an abnormality in which corrosion occurs on the inner surface of the cylinder 37 is predicted. However, examples of abnormalities that can be predicted include an abnormality in which engine oil deteriorates due to accumulation of condensed water in the oil pan, an abnormality in the oil pump that pumps the engine oil, an abnormality in which the engine 22 misfires due to accumulation of condensed water in the EGR pipe 152 of the EGR device 150 or in the intake pipe 24, and an abnormality caused by deposits building up in the EGR pipe 152 of the EGR device 150, the intake pipe 24, or the blow-by gas pipe 90.

[0036] When predicting an abnormality in which engine oil deteriorates due to condensed water accumulating in the oil pan, instead of step S130, a determination is made as to whether the operating state Ste is in the region β heavy use state, and step S140 is not executed. Condensed water generated in the cylinder 37 travels to the oil pan and mixes with the engine oil, but evaporates when the engine 22 is fully warmed up. When the operating state Ste is in the region β heavy use state, that is, when the engine 22 is frequently operated at low speeds and low loads, i.e., when there are many short trips, it is thought that the condensed water mixed in the engine oil cannot evaporate and remains, causing the engine oil to emulsify and otherwise deteriorate. Therefore, by determining whether the operating state Ste is in the region β heavy use state instead of step S130, an abnormality in which engine oil deteriorates can be predicted appropriately.

[0037] When predicting an abnormality in the oil pump that pumps engine oil, instead of step S130, the system determines whether the operating state Ste is in the region β heavy use state, and instead of step S140, determines whether the outside air temperature is below zero degrees Celsius, whether the engine oil temperature at the time of starting the engine 22 is below zero degrees Celsius, and whether the vehicle 20 has been parked for a long time. Condensed water generated in the cylinder 37 and the crankcase 31 accumulates at the bottom of the oil pan and freezes below zero degrees Celsius. Freezing of condensed water is likely to cause an abnormality in the oil pump that pumps engine oil. Condensed water mixed in the engine oil is likely to remain without evaporating when the operating state Ste is in the region β heavy use state, i.e., when the engine 22 is frequently operated at low speeds and low loads, i.e., when there are many short trips. It is believed that condensed water mixed in engine oil is likely to freeze when the outside air temperature is below zero degrees Celsius, the engine oil temperature is below zero degrees Celsius, and the vehicle 20 has been parked for a long time. Therefore, instead of step S130, it is determined whether the operating state Ste is in the region β heavy use state, and instead of step S140, it is determined whether the outside air temperature is below zero degrees Celsius, whether the engine oil temperature at the start of the engine 22 is below zero degrees Celsius, and whether the vehicle 20 has been parked for a long time, thereby making it possible to properly predict an abnormality in the oil pump.

[0038] When predicting an abnormality in which the engine 22 misfires due to accumulation of condensed water in the EGR pipe 152 of the EGR device 150 or in the intake pipe 24, instead of step S130, it is determined whether the operating state Ste is in a region β heavy use state, and the processing routine is executed once per trip without executing step S140. It is believed that condensed water accumulated in the EGR pipe 152 of the EGR device 150 or in the intake pipe 24 evaporates when the engine 22 is under high load. Therefore, when the operating state Ste is in a region β heavy use state, that is, when the engine 22 is frequently operated at low speeds and low loads, the condensed water in the EGR pipe 152 or in the intake pipe 24 is unlikely to evaporate. Furthermore, when the engine 22 is next started, the condensed water accumulated in the intake pipe 24 moves toward the combustion chamber along with the intake air, and therefore, by executing this processing routine once per trip, it is possible to predict an abnormality in which the engine 22 misfires due to condensed water accumulating in the EGR pipe 152 of the EGR device 150 or in the intake pipe 24. Therefore, by determining whether the operating state Ste is in the region β heavy use state instead of step S130 and executing the processing routine once per trip without executing step S140, it is possible to properly predict an abnormality in which the engine 22 misfires.

[0039] When predicting an abnormality due to deposits building up in the EGR pipe 152 of the EGR device 150, the intake pipe 24, or the blow-by gas pipe 90, a determination is made as to whether the operating state Ste is in a region β-frequent use state instead of step S130, and step S140 is not executed. Deposits in the EGR pipe 152, the intake pipe 24, or the blow-by gas pipe 90 often build up when the engine 22 is operated at low speed and low load. Therefore, by determining whether the operating state Ste is in a region β-frequent use state instead of step S130, and not executing step S140, an abnormality due to deposits building up in the EGR pipe 152, the intake pipe 24, or the blow-by gas pipe 90 can be properly predicted.

[0040] In an automobile 20 equipped with an abnormality prediction device for an engine 22 according to the embodiment, the type of trip is set to a "region α heavy use trip," a "region β heavy use trip," or the like using the rotation speed Ne and load factor KL of the engine 22. However, instead of the rotation speed Ne and the load factor KL, the type of trip, i.e., the operating state Ste of the engine 22 and, ultimately, the usage state of the vehicle, may be set using at least one of the maximum or average value of the rotation speed Ne in one trip, the maximum or average value of the vehicle speed V, the average value of the load factor KL, the duration of one trip, the on / off state of the brake pedal 85, and the like.

[0041] The correspondence between the main elements of the Examples and the main elements of the invention described in the "Means for Solving the Problem" section does not limit the elements of the invention described in the "Means for Solving the Problem" section, since the Examples are examples for specifically explaining the mode for implementing the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the Examples are merely specific examples of the invention described in the "Means for Solving the Problem" section. [Industrial Applicability]

[0042] The present invention can be used in industries such as the manufacturing industry of engine abnormality prediction devices. [Explanation of symbols]

[0043] 20 automobile, 22 engine, 23 air cleaner, 24 intake pipe, 25 throttle valve, 26 fuel injection valve, 28 intake valve, 30 spark plug, 31 crankcase, 32 piston, 33 crankshaft, 34 purification device, 35 exhaust pipe, 36 throttle motor, 37 cylinder, 38 ignition coil, 40 crank position sensor, 42 water temperature sensor, 43 pressure sensor, 44 cam position sensor, 46 throttle valve position sensor, 48 air flow meter, 49 temperature sensor, 50 cylinder head cover, 52 intake port, 56 valve, 60 transmission, 62 differential gear, 64a, 64b drive wheels, 70 electronic control unit, 72 CPU, 74 ROM, 76 RAM, 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 Accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, 90 blow-by gas pipe.

Claims

1. An engine abnormality prediction device that predicts an engine abnormality that is an abnormality in an engine mounted on a vehicle, determining an operating state of the engine based on an operating point consisting of an engine rotation speed, which is the rotation speed of the engine, and an engine load factor, which is the load factor of the engine, when the engine was operated in the past; determining whether condensation has occurred in the engine based on the temperatures of components constituting the engine and a dew point temperature; When condensed water is generated in the engine, or when the amount of condensed water generated in the engine is equal to or greater than a predetermined amount, and the engine is in a high-speed, high-load, heavy-use state where the engine is frequently operated at high speed and a high load rate, corrosion of the engine cylinder is predicted as an engine abnormality. Engine abnormality prediction device.

2. 2. The engine abnormality prediction device according to claim 1, When the condensed water is generated and the engine is in the high-speed, high-load operating state, if the engine cooling water temperature is equal to or lower than a predetermined water temperature when the engine is started, corrosion of the cylinder is predicted as an engine abnormality. Engine abnormality prediction device.

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