JP2000257497A - Internal combustion engine control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control system for an internal combustion engine, capable of preventing deterioration of the exhaust emission by providing abnormality detection means in an engine having an exhaust emission control system for estimating an abnormal portion, so as not only to alarm the driver but also to automatically countermeasure the abnormality for the driver who does not respond to the alarm, thus enabling running of the engine in safe conditions to protect it, while preventing a catalyst of the emission control system from deterioration of the exhaust emission. SOLUTION: A control system 1 for an internal combustion engine is provided with a catalytic device for emission control and an exhaust brake in an exhaust passage. The control system is further configured with abnormality detection means 10, comprising an exhaust emission temperature abnormality detection means 20 and detection means 30 for an exhaust emission temperature abnormality in a catalyst, and an abnormality countermeasure means 40 comprising an injection suppression running means 43 for running the internal combustion engine in a fuel injection suppression running mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an internal combustion engine for a vehicle using an exhaust gas purification device using a catalyst.

More specifically, when the internal combustion engine is in an abnormal state, it can be detected and the catalyst can be prevented from being brought to a high temperature state, prompting a driver to repair the engine early, and effectively using the catalyst and the internal combustion engine. The present invention relates to a control device for an internal combustion engine which can be protected in a safe manner.

[0003]

2. Description of the Related Art In an internal combustion engine for an automobile using a gasoline engine or a diesel engine, various abnormal states occur due to failure of engine parts or control sensors.

The following is an example of this abnormal state. [Abnormal state of gasoline engine] In the case of a gasoline engine, if there is an abnormality in the O ₂ sensor or intake air amount detecting means (air flow sensor, intake negative pressure sensor, etc.) or malfunction of the EGR valve, the exhaust gas temperature will be normal. It changes more greatly.

That is, if the oxygen concentration is detected higher than the actual value or the air amount is detected higher than the actual value, the injection amount is controlled to increase, and the fuel becomes rich, that is, the combustion becomes rich. The exhaust gas temperature decreases.
In this case, the H
An increase in the emission amount of C and CO, an increase in the catalyst temperature due to re-combustion of HC and CO by the catalyst, and a risk of melting damage due to the increase in the temperature occur.

On the contrary, if the oxygen concentration is detected lower than the actual value or the oxygen concentration is detected lower than the actual air amount,
The injection amount is controlled to decrease, and the fuel is burned in a lean state, that is, a lean state, and the exhaust gas temperature rises.
In this case, knocking occurs in some cases, and the knock sensor detects the knocking and delays the ignition timing, so that the output drops. Also, the oxygen concentration in the three-way catalyst becomes excessive and the NOx purification efficiency decreases. I do.

If the EGR valve is kept open, the EGR gas becomes excessive, the oxygen becomes insufficient, the fuel is reduced, and the engine stalls. In addition, the temperature of the exhaust gas decreases due to the endothermic reaction between CO ₂ and H ₂ O. Then, the output decreases due to lack of oxygen, the amount of HC and CO increases, and in some cases, black smoke is emitted.

Conversely, when the EGR valve is kept closed, fresh air increases, fuel consumption deteriorates due to an increase in fuel due to an increase in oxygen, and the temperature in the cylinder rises.
x increases and the exhaust gas temperature increases. [Abnormal state of diesel engine] In the case of a diesel engine, if there is an abnormality in the injection timing or injection pressure, or a malfunction of the EGR valve, etc., the exhaust gas temperature greatly changes compared to the normal operation.

While the delay of the fuel injection timing is small, the exhaust gas temperature rises, NOx decreases, black smoke increases, the output decreases, and fuel efficiency deteriorates. If the delay of the injection timing becomes large, it becomes difficult to ignite, misfires and generates white smoke, and the exhaust gas temperature decreases.In this case, the unburned fuel is recombusted by the catalyst, so that the catalyst temperature rises and the melting loss increases. Fear arises.

Conversely, while the advance of the injection timing is small, the exhaust gas temperature decreases, NOx increases, and the output also increases. However, if the advance of the injection timing increases, knocking occurs and the cylinder internal pressure abnormally increases. As a result, the drivability deteriorates and the engine may be damaged.

When the injection pressure decreases, atomization of the spray is hindered, and the injection period is extended, so that the exhaust gas temperature increases and the amount of black smoke increases. The black smoke deteriorates the catalyst due to the occurrence of clogging of the catalyst and an increase in the catalyst temperature due to reburning.

Conversely, when the injection pressure increases, the combustion time is shortened due to the promotion of atomization of the spray and the shortening of the injection period, resulting in an increase in combustion noise, an increase in NOx, and a decrease in exhaust gas temperature.

If the EGR valve remains open, the EGR gas becomes excessive and burns in a fuel-rich state, so that the exhaust gas temperature rises and black smoke increases.
Further, in some cases, it becomes impossible to ignite, a large amount of unburned components is discharged, and there is a risk that the catalyst is melted due to rapid combustion of the unburned components adsorbed on the catalyst.

Conversely, when the EGR valve is kept closed, fresh air increases and burns in a lean state, so that the exhaust gas temperature decreases. In addition, black smoke decreases because fuel burns at once in a short period of time. However, NOx increases.

[Abnormal condition of engine with turbocharger]
In the case of a turbocharged engine, when boost pressure etc. does not increase due to boost leakage etc., since the boost limit injection amount is set in the gasoline engine, the injection amount is limited and the output clearly decreases . In the case of a diesel engine, if the boost limit injection amount is not set, a large amount of black smoke is emitted and the output is reduced.

In the case of a turbo with a waste gate and a variable air ratio (A / R), if a boost pressure higher than a set boost pressure is applied due to a failure of a boost sensor or sticking of a diaphragm, a link or the like, a surge region occurs. Since the turbocharger is operated, there is a possibility that the turbo itself may be damaged or the engine may be damaged. In addition, although the amount of fresh air increases, the black smoke is improved and the output also increases, but in some cases, the spraying deteriorates, leading to an increase in HC.

[Catalyst] On the other hand, in a gasoline engine and a diesel engine, a catalyst is used to purify exhaust gas discharged from these engines.
While maintaining this catalyst in the catalyst activation temperature range, NOx components, unburned HC components, CO components, and the like in the exhaust gas are reduced to N ₂ or CO _2.
Or H ₂ O to purify the exhaust gas. This catalyst has a property that, when exposed to a high temperature, the catalyst is overheated, the catalyst function is deteriorated, and the exhaust gas cannot be purified.

On the other hand, when there is an abnormal injection of the injector or a misfired cylinder, etc., a large amount of unburned components in the exhaust gas is contained, and the unburned HC is abnormally burned by the catalyst. Is significantly higher than the exhaust gas temperature. The state in which the temperature of the catalyst has risen significantly is the state in which the catalyst is most likely to be damaged. If this state continues for a long time, the catalyst will be deteriorated.

[Countermeasures against abnormal situations] In response to these abnormal situations, in the engine of the prior art, when the exhaust gas temperature sensor detects that the exhaust gas temperature has risen abnormally, the driver or the maintenance person A warning light is turned on to notify the user of the abnormality and call attention to encourage repair.

[0020]

However, in the control device for an internal combustion engine according to the prior art, only a warning is issued. It is up to the driver himself to respond.

Particularly in the case of a car, there are various drivers, and some drivers immediately stop driving the engine, that is, the car, and request repairs. There are.

[0022] Therefore, in the case of a driver who does not go to repair even after receiving a warning, the engine is operated in a state of having an abnormality. In addition to this, there is a problem that a further secondary failure occurs from this failure, which leads to a major engine trouble.

Further, at the time of these abnormalities, an appropriate exhaust gas temperature is not maintained and the exhaust gas temperature in the catalyst rises abnormally, so that the exhaust gas is not properly purified and the vehicle runs in an insufficient state. Therefore, there is a problem that pollution occurs and the catalyst is deteriorated.

Therefore, measures to be taken when the engine is abnormal are as follows:
It is important not only in terms of exhaust gas purification but also in terms of engine protection.How to make the driver aware of the rank and severity of the abnormality and repair it before further trouble occurs Is a big issue.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a control device for an internal combustion engine having an exhaust gas purifying device provided with an abnormality detecting means to estimate an abnormal location. In addition to issuing a warning to the driver, the driver who does not respond to the warning is automatically dealt with abnormalities, operating the engine in a safe state, protecting the engine, and repairing the driver And promptly go to repairs.
An object of the present invention is to provide a control device for an internal combustion engine that can protect a catalyst of an exhaust gas purification device from deterioration and prevent deterioration of exhaust gas.

[0026]

A control apparatus for an internal combustion engine for achieving the above object is configured as follows. 1) In the exhaust passage of the internal combustion engine, a catalyst device for purifying exhaust gas, an exhaust brake, and abnormality detection means for detecting an abnormality of the engine, and when the abnormality detection means detects an abnormality, a measure for dealing with the abnormality. Means for controlling the internal combustion engine, wherein the abnormality detecting means calculates a model exhaust gas temperature, which is an exhaust gas temperature in a normal operating state, from the operating state of the internal combustion engine, An exhaust gas temperature abnormality detecting means for determining a temperature deviation from an actually measured exhaust gas temperature, comparing the temperature deviation with a predetermined first threshold value, and detecting an abnormal state of the exhaust gas temperature; A temperature difference between a temperature and an actually measured temperature of the exhaust gas in the catalyst of the catalyst device is compared with a predetermined second threshold value to detect an abnormal state of the temperature of the exhaust gas in the catalyst. Abnormal gas temperature Together they are formed and means output, the abnormality coping means, characterized in that it is formed with an injection amount control operation means.

2) After the abnormality countermeasure suppresses the injection amount, it detects that no effective abnormal state recovery processing has been performed even if the vehicle has traveled a predetermined allowable traveling distance or passed a predetermined allowable time. In this case, the system further comprises a repair urging means for generating an operating state which is a bodily sensation signal for urging the driver of the internal combustion engine to perform a recovery process of the detected abnormal state.

3) The repair urging means is an exhaust brake intermittent operation means for intermittently operating the exhaust brake after a predetermined time. 4) The abnormality detecting means includes an abnormal part estimating means for estimating an abnormal part. 5) The abnormal location estimating means includes: first abnormal location estimating means for estimating an abnormal location related to an abnormal state of the exhaust gas temperature determined from the exhaust gas temperature deviation; and a temperature of the measured exhaust gas temperature and the measured exhaust gas temperature in the catalyst. A second abnormal portion estimating means for detecting an abnormal state of the exhaust gas temperature in the catalyst determined from the difference.

6) When the internal combustion engine is a diesel engine, the first abnormal part estimating means relating to the abnormal state of the exhaust gas temperature determines whether the EGR valve, the boost pressure, and the fuel injection timing are abnormal. It is characterized in that it includes means for estimating whether or not it is not. 7) The second abnormal portion estimating means relating to the abnormal state of the exhaust gas temperature in the catalyst judges whether the amount of unburned HC in the exhaust gas is abnormal or normal.

That is, in an internal combustion engine provided with an exhaust gas purifier in the exhaust passage of the internal combustion engine, the exhaust gas temperature is estimated from the operating conditions of the engine, the deviation from the measured exhaust gas temperature, the measured exhaust gas temperature and the catalyst Determine the temperature difference from the measured temperature in the layer, compare each with a predetermined threshold,
Detects engine malfunction.

The principle of this engine abnormality detection is as follows. Since the fuel injection amount is substantially determined by the engine speed and the accelerator opening, the exhaust gas temperature becomes almost constant depending on the operating conditions unless some abnormality occurs other than the outside air condition. By comparing the calculated value of the gas temperature with the actually measured value, the occurrence of an abnormality in the engine can be detected.

When a large amount of unburned HC is contained,
Since these unburned HCs burn by touching the catalyst and the catalyst layer temperature rises, the temperature difference between the measured value of the exhaust gas temperature and the measured value of the catalyst layer temperature is compared with a predetermined temperature difference. The occurrence of abnormality can be detected.

When an abnormal state is detected based on a comparison between the deviation and the temperature difference and each threshold value, the driver is informed
In addition to notifying the occurrence of an abnormal condition by turning on or blinking the indicator light or issuing an alarm such as an electronic sound or a voice message, estimating the abnormal location in more detail, notifying the abnormal location by displaying the indicator light or voice message, The fuel injection amount is automatically suppressed, and the operation shifts to the injection amount suppression operation for protecting the engine and the catalyst, thereby protecting the engine and the catalyst.

This injection amount suppression operation automatically performs an engine operation operation of reducing the fuel injection amount of the engine or changing the intake throttle and the injection timing. Further, it is possible to prevent the temperature of the exhaust gas from further increasing and the catalyst of the catalyst device from being deteriorated due to the high temperature. In other words, it performs emergency processing.

Further, when the driver does not stop or repair the engine even if the driver exceeds the predetermined allowable traveling distance or allowable time, a signal for prompting early repair is provided by a repair prompting means for intermittently operating the exhaust brake. When the driver emits and sends the driver to repair, the catalyst of the exhaust gas purification device is prevented from deteriorating, and further, a traffic accident caused by driving a troubled vehicle is prevented.

The repair reminder means, which is capable of driving the automobile itself, but gives the driver discomfort or anxiety during driving and urges the driver to repair the vehicle. Besides the intermittent operation of the exhaust brake, a method of preventing the parking brake from being released for a certain period of time, a method of repeatedly sounding a buzzer or voice message at a predetermined time interval, and a method of applying the engine. Can be intentionally made worse.

Further, when the driver does not stop or repair the engine, the exhaust brake is intermittently operated to continuously inform the driver of the occurrence of an abnormality as a bodily sensation, thereby prompting early repair. As a result, it is possible to prevent the deterioration of the catalyst of the exhaust gas purifying device and to prevent a traffic accident due to the driving of the troubled vehicle by prompting the driver to repair the vehicle.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a control device for an internal combustion engine according to the present invention will be described below with reference to the drawings. [Structure] As shown in FIG. 1, in a control device 1 for an internal combustion engine according to an embodiment of the present invention, a catalyst device 3 for purifying exhaust gas is disposed in an exhaust passage 2 of the engine. An exhaust gas temperature sensor 4 for detecting the temperature of the exhaust gas and an in-catalyst exhaust gas temperature sensor 5 for detecting the temperature of the catalyst layer are arranged on the upstream side of the catalyst device 3, respectively. Shutters 6 and 7 are provided.

Then, a controller 8 called an engine control unit (ECU) receives a rotation speed Ne, a load Acc, a rotation speed sensor, an acceleration sensor, a cooling water temperature sensor, and the like for detecting an operation state of the engine.
The cooling water temperature Tw and the like are input to control the overall operation of the engine and to control the exhaust brake shutters 6 and 7.

[Control Device 1] Further, as shown in FIG. 2, the control device 1 for the internal combustion engine detects an abnormality in the engine, and the abnormality detection device 10 detects the abnormality. Occasionally, the system is provided with an abnormality coping unit 40 for coping with the abnormality and a repair prompting unit 50. The calculation portion and the input / output portion of the signal of the control device 1 are generally incorporated in the controller 8 to monitor and control the engine in parallel with the normal engine operation control.

[Abnormality detecting means 10]
Means for detecting exhaust gas temperature deviation related to exhaust gas temperature
21, exhaust gas temperature determination means 22, first abnormal point estimation means 23
Exhaust gas temperature abnormality detecting means 20 comprising: an exhaust gas / intracatalyst exhaust gas temperature difference detecting means 31 relating to the exhaust gas temperature in the catalyst; an exhaust gas temperature in the catalyst determining means 32; The catalyst exhaust gas temperature abnormality detecting means 30 is formed.

[Exhaust Gas Temperature Abnormality Detection Means 20] First, the exhaust gas temperature abnormality detection means 20 will be described. The exhaust gas temperature deviation detection means 21 includes an engine speed Ne indicating the operating state of the internal combustion engine (E). From the accelerator opening Acc corresponding to the engine load, a model exhaust gas temperature Tmc, which is an exhaust gas temperature in a normal operating state, calculated by a previously input calculation map or the like is calculated. Temperature deviation (| Tmc-Tre |), which is the absolute value of the difference from the measured exhaust gas temperature Tre measured in step (1), is obtained.

More specifically, the accelerator opening Acc, shown in FIG.
The reference exhaust gas temperature Tb is obtained from a lever schedule showing the relationship between the rotation speed Ne and the fuel injection amount Q and an exhaust temperature map showing the relationship between the rotation speed Ne, the fuel injection amount Q and the reference exhaust gas temperature Tb shown in FIG. Calculated, and this reference exhaust gas temperature T
b is corrected by the outside air temperature Ta or the cooling water temperature Tw.
The model exhaust gas temperature Tmc is obtained by correcting with β.

In this correction, since the outside air temperature Ta is expected to change from 50 ° C. to 60 ° C. throughout the year, a correction amount Tα due to a change in the intake air temperature is calculated. The correction value Tβ of the exhaust gas temperature is calculated based on the difference between the injection timing and the ignition timing that differs depending on the operating state of the engine, and the calculated value of the reference exhaust gas temperature Tb is corrected to perform the model exhaust gas temperature correction. Find Tmc. The temperature deviation ΔT between the model exhaust gas temperature Tmc and the reference exhaust gas temperature Tb is substantially at most about 30 ° C.

Then, the exhaust gas temperature determining means 22 calculates the exhaust gas temperature deviation (| Tmc-Tre) which is the absolute value of the difference between the model exhaust gas temperature Tmc and the actually measured exhaust gas temperature Tre.
If |) is equal to or greater than a predetermined threshold Tg0, for example, it is determined that the exhaust gas temperature is abnormal.

The threshold value Tg0 varies depending on the type of engine, but is usually between 40 ° C. and 200 ° C. When this exhaust gas temperature abnormal state occurs, the first
The abnormal location estimating means 23 performs the following abnormal location estimation.

In the gasoline engine, it is estimated that the fuel is thin, that is, the fuel is lean, and it is determined that the O ₂ sensor or the air flow sensor is abnormal or the EGR valve is not operating, and the EGR mark is turned on. Notify the driver of the abnormality. Further, in the case of a diesel engine, it is determined that there is excessive EGR due to excessive delay of the fuel injection timing, excessive extension of the injection period (lower injection pressure), no opening or closing of the EGR valve, and the EGR mark is turned on. Notify the driver of the abnormality.

In the case of a turbo-equipped engine, it is detected whether or not the boost map and the boost pressure Pb correspond to each other.
The URBO mark is turned on, and if it is supported, the timing check mark is turned on to notify the driver of the abnormality.

[Exhaust Gas Temperature In-Catalyst Abnormality Detecting Means 30] Next, the means for detecting abnormalities in exhaust gas temperature in the catalysts 30 will be described.
The measured exhaust gas temperature T measured by the exhaust gas temperature sensor 4
A temperature difference (Tc−Tre) between re and the measured exhaust gas temperature Tc in the catalyst measured by the exhaust gas temperature sensor 5 in the catalyst is calculated.

Then, the temperature difference (Tc-Tre) and the predetermined threshold value Δ
Compared with Tc0, the temperature difference (Tc−Tre) is, for example, 40 ° C.
If it is equal to or more than (threshold value ΔTc0), it is determined that the state is the second abnormal state.

When the abnormal state of the exhaust gas temperature in the catalyst occurs, the second abnormal part estimating means 33 estimates that a large amount of unburned fuel is contained in the exhaust gas. It is determined that an abnormality such as injection or a misfired cylinder is most likely to damage the catalyst. [Abnormality coping means 40] In order to cope with these abnormalities, there is provided an abnormality coping means 40 provided with an alarm generating means 41, an injection amount suppressing operation means 42, and an exhaust brake operating means 46 after engine stop.

The alarm generating means 41 emits a visual alarm by turning on or blinking a display lamp for a portion estimated and determined to be abnormal, or generates an audible alarm such as an electronic sound or a voice message.

If the exhaust gas temperature abnormality detecting means 20 determines that an abnormality has occurred, the injection amount suppression operation means 42 automatically reduces the fuel injection amount of the engine or adjusts the intake throttle and injection timing. By changing the engine operation to change the exhaust gas temperature, the exhaust gas temperature is further increased to prevent the catalyst of the catalyst device 3 from being deteriorated due to the high temperature. In other words, it corresponds to emergency processing.

During the injection amount suppression operation, the driver is informed that the injection amount suppression operation is being performed by turning on an indicator light or the like. In addition, during the injection amount suppression operation, the driver feels a lack of power, so that the driver is strongly conscious of the necessity of repair.

The catalyst exhaust gas temperature abnormality detecting means 30
When an abnormal state is detected by the injection amount suppression operation means 42, the engine operation operation of the injection amount suppression operation mode is automatically performed to lower the exhaust gas temperature, and the engine of the engine where the catalyst is most susceptible to damage. In this state, the driver is instructed to stop the engine. If the driver stops as instructed, the exhaust brake shutters 6, 7 around the catalyst device 3 are fully closed, and the supply of oxygen to the catalyst device 3 is stopped. Suppresses the rapid oxidation reaction of unburned HC.

The unburned HC continues to burn in the catalyst device 3 when the supply of oxygen is not interrupted even after the engine is stopped, and the resulting overheating and deterioration of the catalyst are prevented. Avoid dangers. [Repair urging means 50] Then, when the operation is continued irrespective of these abnormalities, the repair urging means 50 operates. As a specific means of the repair urging means 50, there is an exhaust brake intermittent operation means 51.

The exhaust brake intermittent operation means 51 is used when the driver does not stop the vehicle irrespective of whether the engine is in an abnormal state, that is, after a warning of the abnormality is issued, the abnormality is repaired within a predetermined time. When it is detected that the operation is continued without performing the operation, the exhaust brake is intermittently operated with a predetermined time interval, and the signal from the ECU is transmitted to the electromagnetic valve EV.
And close the exhaust brake shutter 6 or 7. As a result, the driver is in a state of urgency to repair the vehicle, taking into account a state of being extremely uncomfortable or uneasy.
That is, this is a means for taking the direction of stopping by taking a method that exaggerates the abnormality of the engine itself. [Operation: Flow] Next, the operation of the control device for an internal combustion engine according to this embodiment will be described with reference to the flowchart of FIG.

First, when the engine is operated and this flow is started, the rotational speed Ne, the accelerator opening Acc, and the outside air temperature T detected and measured by various sensors in step S10.
a, input various data such as the cooling water temperature Tw.

Whether the operating state of the engine is a steady operation or not is determined by determining whether the change amount Ne of the rotational speed Ne is equal to or less than a predetermined change threshold value Ne0 and the change amount ΔA of the accelerator opening Acc.
It is determined whether or not cc is equal to or less than a predetermined change threshold Acc0. When it is determined that the vehicle is not in a steady operation (NO), the flow returns to the flow, returns to the flow again, and returns to the first step S
Repeat from the input of 10 data. [Detection of Exhaust Gas Temperature Abnormality] When it is determined that the operation is steady (YES), the exhaust gas temperature abnormality detecting means 20 detects an exhaust gas temperature abnormality in step S20.

In this step S20, as shown in a detailed flow chart in FIG. 6, first, the exhaust gas temperature deviation detecting means 21 calculates the reference exhaust gas temperature Tb.
The corrected exhaust gas temperature Tmc is calculated by the correction, and a deviation (| Tmc-Tre |) which is the absolute value of the difference from the actually measured exhaust gas temperature is detected.

Then, in step S21, the exhaust gas temperature deviation means (| Tmc-
Tre |) is equal to or greater than a predetermined threshold Tg0,
Hereinafter, if not (NO), it is determined that the exhaust gas temperature is normal, and the process goes to step S30.

If so (YES), it is determined that the exhaust gas temperature is abnormal, and in step S23, the first abnormal location estimating means 23 performs the following first abnormal location estimation and display. That is, in step S23a, the EGR
The operation state of the valve is checked, and it is detected whether or not the actual lift amount Legr follows the command value LEGR of the lift amount of the EGR valve due to the change in the accelerator opening Acc. Is determined, and the EGR mark is turned on in step S23b.

In the case of a turbo-charged diesel engine, it is further detected in step S23c whether or not the boost map value Pb0 and the boost pressure Pb correspond to each other, and if they correspond to each other (YES). , Step S23d
To turn on the timing check mark. If the timing check mark is not supported (NO), it is determined that the turbo is defective, and T is determined in step S23e.
Turn on the URBO mark. [Handling of Exhaust Gas Temperature Abnormal State] In this step S20, when it is determined that the exhaust gas temperature is abnormal, the procedure goes to step S40A to deal with the abnormal exhaust gas temperature state.

In step S40A. In step S41A, a first alarm, such as turning on the warning light WL, is generated by the alarm generating means 41, and the injection amount suppressing operation by the injection amount suppressing operation means 42 is started in step S42A. In the injection amount suppression operation, while decreasing the injection amount, retarding the injection timing or retarding the injection timing, or injecting the injection amount according to the injection amount control map LM for performing intake throttle while turning on the lamp LIM indicating that this operation state has been entered. Start the operation of the engine in the suppressed operation mode.

At the same time, a running distance check in step S43A is performed. That is, in step S43Aa, the counting of the travel distance is started to check the travel distance DIS after the warning, and the travel distance is determined in step S43Ab. Specifically, for example, the determination is made based on whether or not a predetermined allowable traveling distance DIS0, which is required to reach the nearest maintenance shop, for example, exceeds 200 km.

If it is within this distance (YES), it is determined in step S44A whether or not repair has been performed. This determination is made based on whether or not a reset code indicating that the engine failure location has been repaired has been input to the controller ECU.

If the vehicle has been repaired (YES), the flow goes to step S46A. In step S46A, the first alarm lamp LIM is turned off, the injection amount suppression operation is canceled, and the normal injection amount control map LM is used. Return to the injection amount map and return.

If not repaired (NO), step S
When the vehicle goes to 43Ab and exceeds the allowable traveling distance DIS0 without being repaired (NO), the process proceeds to the repair urging operation in step S50.

[Repair prompting operation] In this step S50, a repair prompting operation is performed.
CU) to the solenoid valve to start the intermittent operation of the exhaust brake for intermittently operating the exhaust brake shutter 6 or 7. By the operation of this exhaust brake,
Taste the driver in a very urgent and uneasy condition and make repairs urgent.

Then, the operation is managed while determining whether or not there is a repair in step S52. If the repair is not performed, the process returns to step S51 to continue the intermittent operation of the exhaust brake. If the repair is performed, the intermittent operation of the exhaust brake is performed in step S53. Cancel driving and return.

[Detection of Abnormality in Exhaust Gas Temperature in Catalyst] Next, in step S20, the exhaust gas temperature deviation (| Tmc-Tr
If |) is smaller than the predetermined threshold value Tg0, it is determined that the exhaust gas temperature is not abnormal, and the process proceeds to step S30, where the in-catalyst exhaust gas temperature abnormality detecting means 30 indicates that the in-catalyst exhaust gas temperature is abnormal. Or normal.

In step S30, first, in step S31, the exhaust gas / intra-catalyst exhaust gas temperature difference detecting means 31
As a result, the difference between the measured exhaust gas temperature Tre and the measured exhaust gas temperature Tc in the exhaust gas / exhaust gas in the catalyst (Tc−T
re) is detected.

In step S32, the catalyst exhaust gas temperature determination means 32 compares the exhaust gas / catalyst exhaust gas temperature difference (Tc-Tre) with a predetermined threshold value .DELTA.Tc0. Internal exhaust gas temperature difference (Tc-Tr
If e) is equal to or smaller than the predetermined threshold value ΔTc0, the routine returns as there is no abnormality.

If the difference between the exhaust gas and the temperature of the exhaust gas in the catalyst (Tc−Tre) is equal to or larger than a predetermined threshold value ΔTc0, it is determined that the temperature of the exhaust gas in the catalyst is abnormal, and step S
In 33, the second abnormal point estimating means 33 estimates the point where the abnormal state of the exhaust gas temperature in the catalyst has occurred.

In the second abnormal portion estimation, it is estimated that a large amount of unburned gas is contained in the exhaust gas, and the catalyst is most damaged by abnormal injection of the injector or a misfired cylinder. It is determined that a prone abnormality has occurred, and in step S33a, the injector mark of the warning light flashes to call attention. [Countermeasures for abnormal state of exhaust gas temperature in catalyst] Then, in step S40B, the means for coping with abnormal temperature of exhaust gas in catalyst 40 copes with the abnormal state of temperature of exhaust gas in the catalyst.

First, in step S41B, the emergency warning light (STOP!) Is turned on by the second warning means so as to stop the engine (vehicle), and in step S42B,
While the lamp LIM indicating that the injection amount suppression operation mode has been entered is turned on by the injection amount suppression operation means 42,
The injection amount suppression operation is started on the injection amount control map LM.

In step S43B, the engine operating time after the start of the injection amount suppression operation is checked. That is, counting of the engine operation time is started in step S43Ba, and it is determined in step S43Bb whether the engine operation time TIME has exceeded a predetermined allowable time TIME0 (for example, 10 minutes).

If it is within the predetermined allowable time (YES), it is determined in step S43C whether or not the engine has been stopped.
This determination can be made from the position of the engine start key, but other methods may be used. When the engine is not stopped (NO), the process returns to step S43B, and the engine operating time is checked.

Then, when the engine is stopped (YES)
In step S47B, the exhaust brake is operated by the exhaust brake operating means 46 after the engine is stopped. In this step S47B, the exhaust brake shutters 6, 7 before and after the catalyst device 3 are closed, and the supply of oxygen to the catalyst is stopped. Accordingly, since the exhaust brake shutters 6 and 7 located before and after the catalyst are fully closed, the supply of oxygen is stopped and a rapid oxidation reaction of unburned (residual) HC can be prevented and the catalyst can be protected from deterioration. .

When the engine stops, step S48B
To determine if there is any repair. This determination is made based on whether or not a reset code indicating that the engine failure location has been repaired has been input to the controller ECU.

If the vehicle has been repaired (YES), the flow goes to step S49B. In step S49B, the emergency warning lamp (STOP!) Lamp of the second warning and the lamp LIM for the injection amount suppression operation are turned off. The suppression operation is released, the injection amount control map LM is returned to the normal injection amount map, and the process returns.

If not repaired (NO), step S
When the time goes to 43Bb and the time exceeds the allowable time TIME0 without being repaired (NO), the process proceeds to the repair urging operation in step S50. [Repair reminder operation] In this step S50, a repair reminder operation is performed in the same manner as described above, and due to the intermittent operation of the exhaust brake, the driver is urged to repair the vehicle due to a very uncomfortable and uneasy state. To

Then, in the same manner as described above, the operation is managed while determining whether or not there is a repair in step S52. If the repair is not performed, the process returns to step S51 to continue the intermittent operation of the exhaust brake, and if the repair is performed, the process proceeds to step S53. To release the intermittent operation of the exhaust brake and return.

[Effect] The present apparatus is configured as described above.
In addition, the operation is performed according to the flow as described above, and by performing the detection, comparison, determination, and control as described above, estimation and display of a portion considered to be a source of abnormality are automatically performed, and the injection amount suppression operation is automatically performed. In addition, it is possible to quickly take a measure that is determined to be optimal according to the driver's response. Therefore, according to the engine control device 1 described above, the following effects can be obtained.

[Exhaust Gas Temperature Abnormal State] In the case of a gasoline engine, an abnormality of the O ₂
When the fuel is thin, that is, lean due to the inactivation of the GR valve, or in a diesel engine,
In the case of excessive delay of injection timing, extension of injection period (lower injection pressure), excessive EGR (no opening 等, etc.), or boost leakage with turbocharger, etc., the measured exhaust gas temperature is Since it greatly differs from the model exhaust gas temperature, this abnormal state of the exhaust gas temperature can be detected by comparing the calculated value of the model exhaust gas temperature with an exhaust temperature map or the like and the actually measured value.

When it is detected that the exhaust gas temperature is in an abnormal state, the point considered to be abnormal at this time is notified to the driver, and the injection amount and the injection timing are controlled so as not to reach the temperature at which the deterioration of the catalyst starts. Automatically performs the injection amount suppression operation with control of. At the same time, a sign indicating that the injection amount suppression operation is being performed is issued, and this sign and the lack of engine power due to the reduced injection amount allow the driver to feel the need for quick repairs. So you can
Repairs can be made reliably, resulting in protection of the engine and catalyst.

Further, if the driver does not repair the vehicle even if he or she moves beyond a predetermined driving distance despite warning of the abnormal state of the exhaust gas temperature, the exhaust brake is intermittently provided after a certain period of time. By operating the driver, the driver can experience the abnormality of the engine itself, that is, by the repair urging operation,
It can be a feeling of repair. [Abnormal temperature of exhaust gas in catalyst]

In a state where the injector is abnormally injected or there is a misfired cylinder, a large amount of unburned fuel in the exhaust gas is contained, and the catalyst is most susceptible to damage, the temperature of the exhaust gas in the catalyst becomes the expected value. Since the measured value differs from the measured value of the exhaust gas temperature upstream of the catalyst and the measured value of the catalyst layer, the abnormal state of the exhaust gas temperature in the catalyst is detected. When it is determined, the driver is instructed to stop the engine, and if it stops as instructed, fully close the exhaust brakes before and after the catalyst,
Since the supply of oxygen to the catalyst can be stopped and the rapid oxidation reaction of unburned HC can be suppressed, the progress of combustion, overheating, and deterioration of the catalyst can be prevented.

If the driver does not stop the vehicle irrespective of the abnormal state of the exhaust gas temperature in the catalyst, the exhaust brake is intermittently operated after a certain period of time to repair the driver. By taking a method that exaggerates the abnormality of the engine itself by the dunning operation, the engine can be stopped and taken in the direction of repair.

[0090]

As described above, according to the control apparatus for an internal combustion engine according to the present invention, the following effects can be obtained.

When the temperature of the exhaust gas of the engine greatly deviates from the normal temperature of the exhaust gas or when the temperature of the catalyst layer rises significantly more than the temperature of the exhaust gas, an alarm is issued and the injection amount suppressing operation is automatically performed. In addition, abnormal combustion of the engine can be prevented, and generation of an abnormally high temperature or sulfate, an increase in the temperature of exhaust gas in the catalyst, and the like can be prevented. Therefore, deterioration of the catalyst can be prevented and the life of the catalyst can be extended. Since the catalyst can be prevented from deteriorating, a reduction in exhaust gas purification capacity can be prevented, and a deterioration in fuel efficiency can be prevented. As a result, the engine itself is taken care of,
It can greatly contribute to the reduction of exhaust gas.

[0092] For the driver who does not care anything only with the abnormality warning light, the intermittent use of the exhaust brake causes the driver to experience the abnormal state by the prompting for repair without damaging the engine. So that they can be taken in a direction that can be repaired before causing catastrophic damage to the engine or catalyst.

Therefore, since the driver does not drive the faulty vehicle, accidents caused by these can be prevented, and the safety of the user and the pedestrian can be ensured. In addition, since repairs can be made before a major trouble occurs, repair costs can be reduced.

That is, in the engine having the exhaust gas purifying device, not only the abnormal part is estimated and a warning is issued to the driver, but also the driver who does not deal with the warning is automatically dealt with the abnormality. In a safe condition to protect the engine, and by prompting the driver for repair, a driving condition prompting the driver's repair can be generated to promptly go to repair. This protects against deterioration and prevents deterioration of exhaust gas.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an internal combustion engine according to the present invention.

FIG. 2 is a configuration diagram of a control device for an internal combustion engine according to the present invention.

FIG. 3 is a diagram of a lever schedule showing a relationship among an engine speed, a fuel injection amount, and an accelerator opening.

FIG. 4 is an exhaust temperature map showing a relationship among an engine speed, a fuel injection amount, and an exhaust temperature.

FIG. 5 is a diagram showing a flow of a control device according to the present invention.

FIG. 6 is a diagram showing a flow of a part for detecting an exhaust gas temperature abnormality in FIG. 5;

FIG. 7 is a diagram showing a flow of a portion for detecting abnormalities in exhaust gas temperature in the catalyst in FIG. 5;

8 is a diagram showing a flow of a part for dealing with an abnormal state of exhaust gas temperature in FIG.

9 is a diagram showing a flow of dealing with an abnormal state of exhaust gas temperature in the catalyst of FIG. 5;

FIG. 10 is a diagram showing a flow of the repair urging operation of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control device of internal combustion engine E Engine 2 Exhaust passage 3 Catalyst device 4 Exhaust gas temperature sensor 4 5 Exhaust gas temperature sensor in catalyst 6, 7 Exhaust brake shutter 8 Controller (ECU) 10 Abnormality detection means 20 Exhaust gas temperature abnormality detection means 21 Exhaust gas temperature deviation detecting means 22 Exhaust gas temperature determining means 23 First abnormal part estimating means 30 Exhaust gas temperature abnormal detecting means in catalyst 31 Exhaust gas / exhaust gas temperature difference detecting means in catalyst 32 Exhaust gas temperature determining means in catalyst 33 2 Abnormal location estimation means 40 Abnormal response means 41 Alarm generation means 42 Injection amount suppression operation means 46 Exhaust brake activation means after engine stop 50 Repair prompting means 51 Exhaust brake intermittent operation means

Claims (7)

[Claims] An exhaust gas purifying catalyst device, an exhaust brake and an abnormality detecting means for detecting an abnormality of the engine are provided in an exhaust passage of an internal combustion engine. When the abnormality detecting means detects an abnormality, the abnormality is dealt with. An abnormality detecting means for calculating a model exhaust gas temperature, which is an exhaust gas temperature in a normal operating state, from the operating state of the internal combustion engine. An exhaust gas temperature abnormality detecting means for determining a temperature deviation between the gas temperature and the actually measured exhaust gas temperature, comparing the temperature deviation with a predetermined first threshold value, and detecting an abnormal state of the exhaust gas temperature; Determine the temperature difference between the measured exhaust gas temperature and the measured exhaust gas temperature in the catalyst of the catalyst device,
A catalyst exhaust gas temperature abnormality detecting means for detecting an abnormal state of the catalyst exhaust gas temperature by comparing the temperature difference with a predetermined second threshold value; A control device for an internal combustion engine, characterized in that it is provided with an injection amount suppressing operation means. 2. After the abnormality countermeasure suppresses the injection amount, it detects that the vehicle has not traveled a predetermined allowable traveling distance or passed a predetermined allowable time, and that no effective abnormal state recovery processing has been performed. The system further comprises a repair prompting means for generating an operating state serving as a bodily sensation signal for prompting the driver of the internal combustion engine to perform a recovery process of the detected abnormal state. Item 2. The control device for an internal combustion engine according to Item 1. 3. The control device for an internal combustion engine according to claim 2, wherein said repair urging means is an exhaust brake intermittent operation means for intermittently operating an exhaust brake after a predetermined time. 4. The apparatus according to claim 1, wherein said abnormality detecting means includes an abnormal part estimating means for estimating an abnormal part.
3. The control device for an internal combustion engine according to any one of 3. 5. An abnormal point estimating means for estimating an abnormal point relating to an abnormal state of the exhaust gas temperature determined from the exhaust gas temperature deviation, an actual abnormal exhaust gas temperature and an actual exhaust gas in the catalyst. 5. The control device for an internal combustion engine according to claim 4, further comprising a second abnormal portion estimating means for detecting an abnormal state of the exhaust gas temperature in the catalyst determined from the temperature difference. 6. The engine according to claim 1, wherein the internal combustion engine is a diesel engine, and the first abnormal portion estimating means related to the abnormal state of the exhaust gas temperature determines whether the EGR valve, the boost pressure, and the fuel injection timing are abnormal. 6. The control device for an internal combustion engine according to claim 5, further comprising: means for estimating the following. 7. The system according to claim 5, wherein the second abnormal portion estimating means relating to the abnormal state of the exhaust gas temperature in the catalyst determines whether the unburned HC amount in the exhaust gas is abnormal or normal. Control device for internal combustion engine.