JPH0726560B2 - Prediction system for parts deterioration of internal combustion engine for vehicles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a device deterioration prediction device for an internal combustion engine for a vehicle, and more specifically, it can predict and display until performance deterioration of each component of the internal combustion engine reaches a limit. With regard to such a device.

<Prior Art> Conventionally, in an internal combustion engine for a vehicle, various devices have been proposed for diagnosing a failure of a predetermined component or a predetermined control system and issuing a warning of this failure. When the above does not operate normally, the occurrence of such a failure is automatically diagnosed and a warning lamp is turned on to notify the driver, and a predetermined fail-safe control is performed.

<Problems to be Solved by the Invention> However, although the disconnection of the signal line or the power supply line occurs on / off, for example, the detection performance in sensors such as an oxygen sensor and an air flow meter, a fuel injection valve, etc. The operational performance tends to deteriorate gradually, and beyond a certain deterioration level, it tends to become unusable.However, the above-mentioned deterioration progresses simply depending on the usage time and the mileage. It is not decided according to the above, but it will vary greatly depending on the variation of each part and the usage environment.

In the conventional alarm system, a warning is issued when a part becomes completely unusable, and if the parts are deteriorated in the usable range, it does not give any information,
Even if it is configured to notify that it is usable but has deteriorated, it is difficult to judge or give an indication of how much deterioration has occurred. Although it can be predicted that maintenance will be required, it is unclear when the maintenance will be required, so in practice, even if a warning about a deterioration condition is issued, it can be used as maintenance information. I couldn't.

The present invention has been made in view of the above-mentioned problems, and it is possible to display how much deterioration of a part will exceed the limit, and to provide it as maintenance information before the part becomes completely unusable. The purpose is to be able to perform maintenance only on the necessary parts before they are disabled.

<Means for Solving the Problem> Therefore, in the present invention, as shown in FIG. 1, the performance deterioration level is quantified for each predetermined component of the internal combustion engine based on the detected value of the engine operating state related to the component. A performance deterioration level quantifying means, a storage means for storing the performance deterioration level quantified by the performance deterioration level quantifying means for each part as a parameter of a vehicle travel distance or a vehicle travel time, and a storage means stored in the storage means. Based on the change rate of the performance degradation level for each part, the subsequent progress of the performance degradation level is predicted, and based on the prediction result, the vehicle travel distance or vehicle travel time until the relevant component reaches the performance degradation limit level is predicted. A limit reaching prediction calculating means for calculating; and a displaying means for displaying the vehicle travel distance or vehicle running time predicted and calculated by the limit reaching prediction calculating means for each part. A component deterioration prediction device for an internal combustion engine for a vehicle is configured.

Here, as shown by the dotted line in FIG. 1, when there are a plurality of types of performance degradation levels quantified by the performance degradation level quantifying means for a predetermined component, each numerical value indicating the performance degradation level is set in the same unit. After the conversion, it is preferable to provide a multi-level processing means for calculating a square root of a value obtained by adding squared values of the respective numerical values and storing the calculation result as a numerical value indicating a performance deterioration level of the component in the storage means.

<Operation> According to such a configuration, the performance deterioration level quantifying means quantifies the performance deterioration level for each predetermined component of the internal combustion engine based on the detected value of the engine operating state related to the component, and the quantified performance The reduction level is stored by the storage means for each part using the vehicle traveling distance or the vehicle traveling time as a parameter.

Then, the limit arrival prediction calculation means, based on the change rate of the performance deterioration level for each component stored in the storage means,
After that, the progress of the performance deterioration level is predicted, and based on the prediction result, the vehicle travel distance or the vehicle travel time until the component reaches the performance deterioration limit level is predicted and calculated. Here, the vehicle traveled distance or the vehicle traveled time to the performance deterioration limit calculated by prediction is displayed for each part by the display means.

In this way, the performance deterioration level of each part is stored in association with the vehicle mileage or the vehicle travel time, and from the current progress rate of the performance deterioration, how much further mileage or travel time the part will reach the limit. The prediction result is displayed and the prediction result is displayed.

Further, the multi-level processing means converts each numerical value indicating the performance deterioration level into the same unit when there are plural kinds of performance deterioration levels quantified by the performance deterioration level quantifying means for a predetermined component. , A square root of a value obtained by integrating squared values of the respective numerical values is calculated, and the calculation result is stored in the storage means as a numerical value indicating a performance deterioration level of the component, and a plurality of types of performance deterioration levels are indicated for the same component. When there is a numerical value, one numerical value is specified as the performance deterioration level of the part from these plural types.

<Examples> Examples of the present invention will be described below.

In FIG. 2 showing the system configuration of one embodiment, air is sucked into an internal combustion engine 1 mounted on a vehicle from an air cleaner 2 through an intake duct 3, a throttle valve 4 and an intake manifold 5. A fuel injection valve 6 is provided in the branch portion of the intake manifold 5 for each cylinder (four cylinders in this embodiment). The fuel injection valve 6 is an electromagnetic fuel injection valve that is opened by energizing a solenoid, is closed by deenergizing, and is opened by being energized by a drive pulse signal from a control unit 12 described later. No Fuel is pumped from the fuel pump F / P and adjusted to a predetermined pressure by the pressure regulator P / R.

Each combustion chamber of the engine 1 is provided with a spark plug 7, which causes spark ignition to ignite and burn the air-fuel mixture. Exhaust gas is discharged from the engine 1 through the exhaust manifold 8, the exhaust duct 9, the three-way catalyst 10 and the muffler 11.

The control unit 12 includes a CPU, ROM, RAM, a microcomputer including an A / D converter and an input / output interface, receives input signals from various sensors, and performs arithmetic processing as described later, The operation of the fuel injection valve 6 provided for each cylinder is controlled.

As the various sensors, an air flow meter 13 of a hot wire type or a flap type is provided in the intake duct 3. In addition, a crank angle sensor 14 is provided
In the case of a cylinder, a reference angle signal REF for each crank angle of 180 °
And a unit angle signal POS for each crank angle of 1 ° or 2 °. Here, the engine rotation speed N can be calculated by measuring the cycle of the reference angle signal REF or the number of generated unit angle signals POS within a predetermined time.
A water temperature sensor 15 for detecting the cooling water temperature Tw of the water jacket of the engine 1 is also provided.

Further, an oxygen sensor 16, which is known as an air-fuel ratio sensor, is provided in the collecting portion of the exhaust manifold 8 (exhaust passage collecting portion of each cylinder), and the air-fuel ratio of the air-fuel mixture sucked into the engine 1 via the oxygen concentration in the exhaust gas is provided. To detect. Further, the throttle valve 4 is additionally provided with a throttle sensor 17 for detecting the opening TVO by a potentiometer.

Here, the CPU of the microcomputer incorporated in the control unit 12 performs arithmetic processing according to the program on the ROM shown as the flowcharts in FIGS. 3 to 9 to perform the fuel injection control including the air-fuel ratio learning correction. , Self-diagnosis of each part of the fuel supply control system is performed based on the correction state by the air-fuel ratio learning correction, and further, as a function of the component deterioration prediction apparatus according to the present invention, when the component deteriorates to the performance limit based on the self-diagnosis, The predicted travel distance (or travel time) of the vehicle is calculated and displayed.

In this embodiment, the functions as the performance deterioration level digitizing means, the limit reaching prediction calculating means, and the multi-level processing means are achieved by the program shown in the flowcharts of FIGS. The means corresponds to the RAM of the microcomputer built in the control unit 12, and the display means corresponds to, for example, a digital display device (not shown) provided near the driver's seat of the vehicle.

Next, with reference to the flow charts of FIGS. 3 to 9, the operation processing of the microcomputer in the control unit 12 will be described.

The air-fuel ratio feedback control routine shown in the flowchart of FIG. 3 is executed every one revolution (1 rev) of the engine 1.

First, step 1 (denoted as S1 in the figure. The same applies hereinafter)
Then, the detection signal (voltage) output from the oxygen sensor (O ₂ / S) 16 according to the oxygen concentration in the exhaust gas is A / D converted and input.

In the next step 2, the engine speed N and the basic fuel injection amount
The manipulated variable data is searched and obtained from a map in which the manipulated variable of the air-fuel ratio feedback correction coefficient LMD is stored in advance for each operating state divided into a plurality by Tp.

The correction coefficient LMD is set and controlled by the proportional / integral control in this embodiment, and the manipulated variables of the rich control proportional portion PR, the lean control proportional portion PL, and the integral portion I are searched from the map.

In step 3, the output of the oxygen sensor 16 is compared with the slice level corresponding to the target air-fuel ratio to determine whether the actual air-fuel ratio is rich or lean with respect to the target.

If it is determined that the air-fuel ratio is rich with respect to the target, the routine proceeds to step 4 and the rich first-time determination flag fR is determined. Since the rich initial determination flag fR is set to zero in the lean state of the air-fuel ratio, when this time is the first time of rich detection, it is determined in step 4 that the rich initial determination flag fR is zero.

If it is the first time of rich detection, the routine proceeds to step 5, where the value of the air-fuel ratio feedback correction coefficient LMD set up to the previous time is set to the maximum value a.

Then, in the next step 6, it is determined whether or not the normal learning counter nl (see FIG. 10), which is set to a predetermined value at the first transition from the transient operation to the steady operation as described later, is zero. When the normal learning counter nl is not zero,
In step 7, the normal learning counter nl is decremented by 1, and in the next step 10, a set in step 5 is added to the integrated value Σa up to the previous time to update the integrated value Σa and the rich first time The counter nR is incremented by 1 and the latest value Ti is added to the integrated value ΣTi of the fuel injection amount Ti.
Is added to update ΣTi.

That is, the normal learning counter nl is decremented by 1 each time the rich detection is first performed after the predetermined value is set at the first transition from the transient operation to the steady operation, and the maximum value a of the correction coefficient LMD and the fuel injection are performed each time. The rich initial counter nR is incremented by 1 as the amount Ti is integrated, and the data collected while the normal learning counter nl is counted down is compared with the data during the learning period of the fuel injection valve 6. Then, the supply error amount of the fuel injection valve 6 is detected.

As will be described later, in the first lean detection, the minimum value b of the air-fuel ratio feedback correction coefficient LMD and the fuel injection amount Ti are integrated and the lean initial counter nL is incremented by 1.

On the other hand, when it is determined in step 6 that the normal learning counter nl is zero, the process proceeds to step 8 and the F / I learning flag FI for determining the learning period of the fuel injection valve (F / I) 6.
Determine l. Here, when the F / I learning flag FIL is 0 and the cylinder-by-cylinder learning period of the fuel injection valve 6 is reached, the routine proceeds to step 9 and after the F / I learning flag FIL becomes 0, F / I
It is determined whether or not a timer Tmacc2 (see FIG. 10) for measuring the period during which learning (data sampling) is prohibited is zero.

When the timer Tmacc2 is not zero, the step
Jump to step 10 and proceed to step 11. If the timer Tmacc2 is zero, proceed to step 10 to determine the LMD maximum value a.
And the fuel injection amount Ti are integrated and the rich initial counter nR is incremented by 1.

That is, until the normal learning counter nl becomes zero,
When the I learning flag FIL is 0 and the timer Tmacc2 is 0, Σa and ΣTi are calculated and nR is calculated.
Are counted up, when the normal learning counter nl is zero and the F / I learning flag FIl is 1, and when the normal learning counter nl is zero and the timer Tmacc2 is not zero. , Σa, ΣTi integration and nR
However, the count-up of the count-up is not performed. This is a control that is commonly performed in the summation of Σb and ΣTi and the count-up of nL in the lean detection first time, which will be described later.

In step 11, the lean control proportional PL is subtracted from the air-fuel ratio feedback correction coefficient LMD up to the previous time to update, and then in step 12, the rich first-time determination flag fR is set to 1, while the lean first-time determination flag fL is set. Set to zero. Then, when the rich state of the air-fuel ratio is continuing, it is determined in step 4 that the rich first-time determination flag fR is 1, and the process proceeds to step 13. Step 13
Then, the integral I is subtracted from the previous value of the air-fuel ratio feedback correction coefficient LMD to update it.

When the rich state of the air-fuel ratio is eliminated by the decrease of the air-fuel ratio feedback correction coefficient LMD by the integral control and the air-fuel ratio is reversed to lean, the routine proceeds to step 14 and the lean first-time discrimination flag fL is discriminated.

Since the lean first-time determination flag fL is set to zero in step 12 in the air-fuel ratio rich state, if this time is the first time lean detection is performed, a determination of fL = 0 is made in step 14. When fL = 0, the routine proceeds to step 15, where the air-fuel ratio feedback correction coefficient LMD immediately before the air-fuel ratio is reversed from rich to lean is set to the minimum value b.

Then, in the next step 16, the normal learning counter nl
Whether or not (see FIG. 10) is zero is determined in the same manner as in the rich detection first time. When the normal learning counter nl is not zero, the routine proceeds to step 17, where the normal learning counter nl is decremented by 1, and the next step 20
Then, b set in step 15 is added to the accumulated value Σb up to the previous time to update the accumulated value Σb, the lean detection counter nL is incremented by 1, and the accumulated value ΣTi of the fuel injection amount Ti is updated to the latest value. Ti is added and ΣTi is updated.

On the other hand, when it is determined in step 16 that the normal learning counter nl is zero, the process proceeds to step 18 and the F / I learning flag FI for determining the learning period of the fuel injection valve (F / I) 6.
Determine l. Here, when the F / I learning flag FIl is 0 and the cylinder-by-cylinder learning period of the fuel injection valve 6 is reached, the routine proceeds to step 19 and after the F / I learning flag FIl becomes 0, the F / I
It is determined whether or not a timer Tmacc2 (see FIG. 10) for measuring the period during which learning (data sampling) is prohibited is zero.

When the timer Tmacc2 is not zero, the step
Jump to step 20 and proceed to step 21, but if the timer Tmacc2 is zero, proceed to step 20 to set the LMD minimum value b.
And the fuel injection amount Ti are integrated and the lean initial counter nL is incremented by 1.

That is, by the above arithmetic processing, the maximum and minimum value data a and b of the air-fuel ratio feedback correction coefficient LMD and the data of the fuel injection amount Ti are collected every time the air-fuel ratio is inverted when the normal learning counter nl is not zero, Also, the normal learning counter nl
Even if F is zero, if the F / I learning flag FIL is 0 and a predetermined time or more has elapsed since it became 0, the minimum and maximum value data a and b of the air-fuel ratio feedback correction coefficient LMD are similarly obtained. And the data of fuel injection amount Ti are collected,
The rich / lean inversion counts nR and nL are incremented.

Here, the data collected when the normal learning counter nl is not zero is for normal fuel control, and the data collected when the F / I learning flag FIl is zero is the learning for each cylinder of the fuel injection valve 6. (The fuel supply is controlled by correcting only the air-fuel ratio feedback correction coefficient LMD of the specific cylinder by the predetermined value Z).

In step 21, the air-fuel ratio feedback correction coefficient LMD up to the previous time is updated by adding the PR proportional to the rich control, and in next step 22, the rich first-time determination flag fR is set to 0, while the lean first-time determination flag fL is set to 1 Set.

Then, when the lean state of the air-fuel ratio is continuing,
When it is determined in step 14 that the lean initial determination flag fL is 1, the process proceeds to step 23. In step 23, the integral I is added to the previous value of the air-fuel ratio feedback correction coefficient LMD to update it.

Here, in the rich-lean detection for the first time, the arithmetic processing after step 24 is further performed. In step 24, F / I
The learning flag FIl is discriminated. When the F / I learning flag FIl is 1, the process proceeds to step 25. And in step 25,
The normal learning counter nl is discriminated, and when it is not zero, it is terminated as it is, and when it is zero, the routine proceeds to step 26.

In step 26, it is determined whether or not nR and nL for counting the number of times of rich / lean inversion are 8 respectively. nR ＝ n
When it is determined that L = 8, the normal learning counter n
In order to show that the air-fuel ratio inversion circuit has reached the specified number while l is being counted down from the specified value,
After 27, learn the air-fuel ratio feedback correction coefficient LMD before F / I learning.

That is, in the present embodiment, when a predetermined time Tmacc elapses after the transition from the transient operation to the steady state, the normal learning counter nl is counted down from the predetermined value from that time point, until the normal learning counter nl becomes zero, The data of the peak values a and b of the air-fuel ratio feedback correction coefficient LMD and the fuel injection amount Ti are collected, and the data collected here and the data collected during the next cylinder-by-cylinder learning of the fuel injection valve 6 are performed. Are compared with each other, and the supply characteristic error of the fuel injection valve 6 is detected based on the result, and nR = nL = 8 indicates that the data collection until the normal learning counter nl becomes zero. Indicates that it is finished.

In step 27, the F / I learning flag FIl is set to zero,
At the next step 28, nR and nL counted up until the normal learning counter nl becomes zero are reset to zero.

Then, in step 29, the average value (Σa / 8 + Σb / 8) / 2 of the center value of the air-fuel ratio feedback correction coefficient LMD is obtained from Σa and Σb sampled until the normal learning counter nl becomes zero. Furthermore, the value obtained by multiplying this average value by the air-fuel ratio learning correction coefficient KBLRC learned for each operating state is taken as the initial value ▲ ▼ φ (value before learning F / I) of the air-fuel ratio feedback correction coefficient LMD. .

The air-fuel ratio learning correction coefficient KBLRC is set so that the base air-fuel ratio obtained without the air-fuel ratio feedback correction coefficient LMD becomes the target air-fuel ratio except when the control related to the cylinder-by-cylinder learning of the fuel injection valve 6 is being performed. It is learned and is learned and stored for each operating condition classified by the intake air flow rate Q.

In the next step 30, Σa and Σb sampled until the normal learning counter nl becomes zero is reset to zero, and in the next step 31, ΣTi is reset to zero.

On the other hand, when it is determined in step 26 that nR = nL = 8 is not established, it is a normal control state in which the arithmetic processing related to the cylinder-by-cylinder learning of the fuel injection valve 6 is not performed. Make learning settings.

In step 32, it is determined whether or not nR = nL = 0. If it is not zero, this routine is ended as it is, and if it is zero, the routine proceeds to step 33, where the map stored corresponding to the intake air flow rate Q is read. Search for KBLRC and ask for it.

In the next step 34, there are upper and lower peaks of the correction coefficient LMD.
Center value of correction coefficient LMD (a +
b) / 2 and the air-fuel ratio learning correction coefficient KBLRC obtained by searching from the map are weighted averaged according to the following formula based on the predetermined value M to obtain the air-fuel ratio learning correction coefficient KBLRC.

Then, in step 35, the KBLRC map data is rewritten.

On the other hand, when it is determined in step 24 that the F / I learning flag FIl is zero, it is in the state where the cylinder-by-cylinder learning of the fuel injection valve 6 is performed, and the fuel injection valve 6 of the specific one cylinder is In order to detect the supply characteristic error, only the air-fuel ratio feedback correction coefficient LMD of the specific one cylinder is corrected by the predetermined value Z. Also in this state, data such as Σa, Σb, and ΣTi are collected in the same manner as when the normal learning counter nl is not zero, and nR and nL that count the inversion of the air-fuel ratio are counted up from zero.

Therefore, in the next step 38, it is determined whether or not nR = nL = 8, and it is determined whether or not the air-fuel ratio has been inverted a predetermined number of times or more after the learning of the fuel injection valve 6 is started. here,
When it is determined that nR = nL = 8 is not satisfied, the fuel injection valve 6
Since the number of data collected in the learning is small, the process is ended as it is, but when nR = nL = 8, it indicates that a predetermined number of data has been collected, and therefore the process proceeds to step 39 and thereafter.

In step 39, nR and nL counted up with the F / I learning flag FIl being zero are reset to zero.

In step 40, when the F / I learning flag FIl is zero and only the air-fuel ratio feedback correction coefficient LMD of the specific one cylinder is corrected by the predetermined value Z, it is used to control to the target air-fuel ratio of the actual air-fuel ratio. The obtained correction coefficient Areg is calculated according to the following formula.

That is, the correction coefficient Areg is equivalent to ▲ ▼ φ used for the air-fuel ratio control when the normal learning counter nl is not zero, and only the air-fuel ratio feedback correction coefficient LMD of the specific one cylinder is set to the predetermined value Z. As a result of the correction, it is a correction coefficient of the basic fuel injection amount Tp required to control the average air-fuel ratio of each cylinder to the target air-fuel ratio.

In the next step 41, Σa and Σb, which are the data when learning the fuel injection valve 6 used in the calculation in step 40, are reset to zero.

Further, in step 42, the integrated value ΣTi of the fuel injection amount Ti obtained by integrating simultaneously with the integration of Σa and Σb is divided by 16 which is the number of samplings, and is set to the average value mTi during F / I learning. .

Then, in the next step 43, the predetermined value Z is calculated back from the result of the air-fuel ratio feedback correction when only the air-fuel ratio feedback correction coefficient LMD of the specific one cylinder is corrected by the predetermined value Z according to the following equation. .

X ← ▲ ▼ φ / {Areg × F / I number- ▲ ▼ φ (F / I number-
1)} That is, in detecting the supply characteristic error of each fuel injection valve 6, the air-fuel ratio feedback correction coefficient LMD of the specific one cylinder is detected.
Is calculated by multiplying a predetermined value Z (1.16) to calculate the fuel injection amount Ti, and only one specific cylinder is injected with the predetermined value Z.
Fuel control is performed under Ti, and the supply characteristic error of the fuel injection valve 6 is detected depending on whether or not this result appears in the air-fuel ratio feedback correction control as expected.
The calculation formula of (the back calculation value of the predetermined value Z) is derived as follows.

If the fuel of only one specific cylinder is corrected, it is assumed that the air-fuel ratio feedback correction is performed for that cylinder alone.
When φ / Z is reached, the correction of the air-fuel ratio feedback correction coefficient LMD by the predetermined value Z should be canceled and the air-fuel ratio should return to the target air-fuel ratio. On the other hand, since the fuel is not corrected for the other cylinders whose air-fuel ratio feedback correction coefficient LMD is not corrected by the predetermined value Z, the air-fuel ratio correction coefficient ▲ ▼ φ is It does not change. By the way, the air-fuel ratio feedback correction based on the detection of the oxygen sensor 16 is
Since the average air-fuel ratio of all cylinders is controlled to the target air-fuel ratio, the air-fuel ratio feedback correction coefficient for only one specific cylinder
Air-fuel ratio correction coefficient when LMD is corrected ▲ ▼ (Air-fuel ratio feedback correction coefficient LMD and air-fuel ratio learning correction coefficient KBL
The correction coefficient multiplied by RC) should be obtained as the average value of each cylinder.

Therefore, when the fuel of only one specific cylinder is corrected by the predetermined value Z, the air-fuel ratio correction coefficient ▲ ▼ necessary for controlling the air-fuel ratio to the target air-fuel ratio is Becomes

Here, when the air-fuel ratio feedback correction coefficient LMD of only one specific cylinder is corrected by the predetermined value Z, the air-fuel ratio correction coefficient Areg necessary for controlling the air-fuel ratio to the target air-fuel ratio is obtained in step 40. , This Areg in the above formula ▲
The predetermined value Z can be inversely calculated by substituting for ▼, and this back calculation formula is the above-described calculation formula of X, and if the fuel injection valve 6 of the cylinder corrected by the predetermined value Z is normal, the predetermined value Z is obtained. The predetermined value Z should be substantially the same as X, which is the value obtained by back-calculating the predetermined value Z in the above equation. However, when there is a difference between the two, the predetermined value Z in the fuel injection valve 6 of the fuel-corrected cylinder. It shows that the fuel commensurate with the correction by
The supply characteristic error amount in the cylinder is detected according to the difference.

Therefore, in the next step 44, the difference Y (← 1.16 (Z) −X) between the X calculated in step 43 and the predetermined value Z (1.16 in this embodiment) actually used to correct the fuel injection amount Ti. )
Is calculated. This Y corresponds to the learned supply characteristic error rate of the fuel injection valve 6 of the cylinder, and when the fuel injection valve 6 does not inject less fuel than the desired amount, X becomes smaller than the predetermined value Z. In this case, Y is a positive value,
Although Y is an error rate, it can be regarded as a value to be corrected in that cylinder.

Since Y corresponding to the fuel supply characteristic error of the fuel corrected this time is calculated in step 44, the F / I learning flag FIl is set to 1 in the next step 45, and ΣTi is reset to zero in the next step 46.

Further, in step 47, it is determined whether or not the air-fuel ratio correction coefficient Areg obtained in step 40 is substantially equal to the initial value ▲ ▼ φ obtained in the normal fuel control state before learning of the fuel injection valve 6. Since the air-fuel ratio correction coefficient Areg is the data when the fuel of one specific cylinder is corrected, the initial value ▲ ▼
It is normal to change with respect to φ, and when the fuel of the specific one cylinder is corrected but the air-fuel ratio correction coefficient does not change,
It is presumed that the drive control of the fuel injection valve 6 of the cylinder is impossible due to the disconnection or short circuit of the circuit.

Therefore, when it is determined in step 47 that ▲ ▼ φ = Areg, the fuel injection valve 6 of the cylinder in which the fuel has been corrected is abnormal. The number ncyl is determined, and it is determined that the fuel injection valve 6 of the cylinder corrected in steps 49 to 52 is abnormal (NG),
For example, it is displayed on the dashboard of the vehicle.

On the other hand, when it is determined in step 47 that ▲ ▼ φ is not Areg, it is not possible to immediately determine the abnormality of the fuel injection valve 6 although there is a supply characteristic error.
In 53 to step 59, the supply characteristic error rate Y detected this time is stored for each cylinder in association with the fuel injection amount mTi.

In step 53, it is judged whether or not uncyl, in which the number of the cylinder for correcting the fuel for F / I learning is set, is 1. When ncyl is 1, the error rate Y obtained in step 44 is The error rate Y1 of the # 1 cylinder corresponding to the average fuel injection amount mTi obtained in step 42 is stored as data of a map.

If it is determined in step 53 that ncyl is not 1, step
At 55, it is determined whether or not ncyl is 2, and when ncyl = 2, the routine proceeds to step 56, where the error rate Y2 of the # 2 cylinder corresponding to the average fuel injection amount mTi is stored in step 44 as map data. The error rate Y obtained in step S1 is stored.

Further, if it is determined in step 55 that ncyl is not 2, it is determined in step 57 whether ncyl is 3 or 4, and
Is 3, the Y is stored in the error rate Y3 map of the # 3 cylinder in step 58, and when the ncyl is 4, the Y is stored in the error rate Y4 map of the # 4 cylinder in step 59.

In this way, if the error rate Y detected for each cylinder is stored in association with the fuel injection amount mTi for each cylinder, the error rates Y1 to Y4 of the fuel injection valves 6 of the respective cylinders are changed. It is possible to determine how it is changing with respect to, and to make the desired fuel supply control in each cylinder based on this,
It can be determined what kind of correction should be applied to the calculation of the fuel injection amount Ti of each cylinder, and it can also be used as a material for diagnosing abnormality (deterioration degree) of the fuel injection valve 6 of each cylinder.

The routine shown in the flowchart of FIG. 4 is a fuel injection amount calculation routine, which is executed every 10 ms. First, at step 61, the opening TVO of the throttle valve 4, the engine speed N,
Input the intake air flow rate Q, etc.

In the next step 62, the engine speed N and the intake air flow rate Q
Further, based on the air leakage correction value ΔQ set in the flowchart of FIG. 7 which will be described later, the basic fuel injection amount Tp {← K × (Q + ΔQ) Q / N; K is a constant} is common to each cylinder. Calculate The air leak correction value ΔQ is for correcting the amount of leaked air that has leaked into the engine intake system due to downstream measurement of the air flow meter 13 and is not detected by the air flow meter 13.

In step 63, the opening change rate ΔTVO per unit time
, Is determined to be substantially zero. When ΔTVO is substantially zero and the opening is substantially constant, it is determined in step 64 whether or not the rate of change ΔN of the engine rotation speed N obtained in the same manner as ΔTVO is substantially zero.

When it is determined in step 64 that the change rate ΔN is substantially zero, it is considered that the engine 1 is in the steady operation state, and the process proceeds to step 65.

On the other hand, when at least one of ΔTVO and ΔN is not substantially zero and fluctuates, it is considered that the engine 1 is in the transient operation state, and the routine proceeds to step 67.

In step 67, a predetermined value is set in the timer Tmacc that measures the elapsed time after the transition from the transient operation to the steady operation. Then, when transitioning from the transient operation to the steady operation, it is determined in step 65 whether or not the timer Tmacc is zero, and when it is not zero, the routine proceeds to step 66 and the timer is started.
Tmacc is counted down by 1.

Therefore, the timer Tmacc becomes zero only after the predetermined time set in step 67 and the predetermined period according to the execution cycle of this routine have elapsed since the steady operation of the engine 1 was discriminated. Even if the steady operation of the engine 1 is discriminated, the air-fuel ratio fluctuation during the transient operation affects until the timer Tmacc becomes zero. Therefore, a predetermined time or more elapses from the transient operation when the timer Tmacc becomes zero. F / I learning is performed only during the stable steady operation described above (step 69).

In the next step 68, the effective injection amount Te common to each cylinder for normal injection control and the effective injection amount Tedmy for learning (for error detection) of the fuel injection valve 6 are calculated according to the following equations.

Te ← 2 × Tp × LMD × COEF × KBLRC × PRFP Tedmy ← 2 × Tp × (LMD × 1.16) × COEF × KBLRC × PRFP where Tp is the basic fuel injection amount calculated in step 62 of this routine, and LMD is The air-fuel ratio feedback correction coefficient, KBLRC, calculated in the flowchart of FIG. 3, is an air-fuel ratio learning correction coefficient learned for each operating condition in the routine shown in FIG. Further, PRFP is a fuel supply system correction value set in the flowchart of FIG. 7 which will be described later, and the pressure of the fuel pumped to the fuel injection valve 6 due to an abnormality in the fuel pump F / P or the pressure regulator PR is a desired value. When this is no longer the case, this pressure abnormality can be compensated. Further, COEF is various correction coefficients set based on the engine operating state mainly based on the cooling water temperature Tw detected by the water temperature sensor 15.

In the above calculation formula, in comparison with the normal effective injection amount Te, the effective injection amount Tedmy for learning of the fuel injection valve (F / I) 6 is calculated as follows: the air-fuel ratio feedback correction coefficient LMD has a predetermined value Z = 1.1.
By applying this effective injection amount Tedmy to only one specific cylinder during the learning period of the fuel injection valve 6 in which the F / I learning flag FIL is zero, the fuel of one cylinder is forcibly fueled. By changing the injection amount Ti and monitoring the change in the air-fuel ratio feedback correction coefficient LMD, which shows the effect,
The supply characteristic error of the fuel injection valve 6 of the cylinder to which the effective injection amount Tedmy is applied is detected.

In step 69, it is determined whether or not the timer Tmacc is zero. When this timer Tmacc is not zero,
Since the engine 1 is in the transient operation state or is not in the stable steady operation state, the routine proceeds to step 70.

In step 70, the transient flag Facc for determining the transient operation of the engine 1 is set to 1. In the next step 71,
The F / I learning flag FIl is set to 1 to prohibit F / I learning.

Further, in step 72, the normal learning counter nl is set to a predetermined value 16
Is set, nR and nL that count the number of rich / lean inversions are reset to zero, and Σa and Σb that accumulate the peak value of the air-fuel ratio feedback correction coefficient LMD and ΣTi that accumulates the fuel injection amount Ti are set to zero. Reset.

On the other hand, when it is determined at step 69 that the timer Tmacc is zero, the routine proceeds to step 73, where the transient flag Facc
Is determined. Since the transient flag Facc is set to 1 when Tmacc ≠ 0, at the first time when Tmacc = 0, it is determined in this step 73 that Facc = 1 and the process proceeds to step 74. Become.

In step 74, the normal learning counter nl is set to the predetermined value 16 again, and in the next step 75, the transient flag Facc is set to zero.

Then, in the next step 76, it is determined whether or not ncyl for designating the cylinder number to be learned is 4, and when ncyl is 4, ncyl is set in step 77 and the fuel injection valve for the # 1 cylinder is set. 6 is performed, and when ncyl is not 4, the ncyl is increased by 1 in step 78 and the fuel injection valve 6 of any one of the # 2, # 3, and # 4 cylinders is
Let's learn about. Therefore, the cylinder in which the fuel injection valve 6 is learned is sequentially switched every time the timer Tmacc becomes zero, that is, every time the stable steady operation is detected.

In the next step 79, it is determined whether or not the normal learning counter nl is zero. When the normal learning counter nl is not zero, a predetermined value 200 is set in the timer Tmacc2 in step 80, and when the normal learning counter nl is zero, it is determined in step 81 whether or not the timer Tmacc2 is zero. If it is not zero, the routine proceeds to step 82, where the timer Tmacc2 is decremented by 1.

Data such as Σa and Σb in the normal fuel control state based on the effective injection amount Te are obtained until the normal learning counter nl is counted down from a predetermined value to zero.
Next, only the fuel injection valve 6 of the specific one cylinder has the effective injection amount Te.
Controlled based on dmy, new data such as Σa and Σb is obtained during this F / I learning period, but the air-fuel ratio feedback correction coefficient LMD is stable in the intended state where the effective injection amount Tedmy is used. So the timer Tmacc2
Σa during the F / I learning period,
Collection of data such as Σb is prohibited (No.
(See Figure 10).

Next, the cylinder-by-cylinder learning correction of the fuel injection amount performed according to the routine shown in the flowchart of FIG. 5 will be described.

This routine is executed as a background job (BGJ). First, at step 101, the supply characteristic error rates Y1 to Y4 of the fuel injection valve 6 stored for each cylinder corresponding to the fuel injection amount mTi. (Step 53 ~ Step
The absolute value of (see 59) is reset to zero for f plus and f minus, which are flags for determining whether the absolute value of the fuel injection amount Ti is monotonically decreasing with respect to an increase change, and error rates Y1 to Y4. I that specifies the map address of is reset to zero.

Then, in the next step 102, it is determined whether or not the address i is 7 or less, and if i <7, the step i
Continue to 103.

In step 103, the error rate Y1 when the fuel injection valve 6 of the # 1 cylinder is learned is stored from the map stored in correspondence with the fuel injection amount mTi.
The data stored in is read and its value is y1 (i)
Set to.

Also, in step 104, in step 1 in the map of Y1
The data stored in the address i + 1 next to the address i in 03 is read out, and the value is set to y1 (i + 1).

In the next step 105, it is determined whether or not the address i is zero. If the address i is zero at the first time when the process proceeds from step 101 to step 102, the process proceeds to step 106. In step 106, the address i obtained in step 103
Y1 which is the error rate of the fuel injection valve 6 of the # 1 cylinder at = 0
(0) is compared with y (1) at the next address i = 1.

When y1 (0) is large, the routine proceeds to step 107, where f plus 1 which is zero-reset at step 101.
Is set, and when y1 (1) is large, step 108
Proceed to step 101 and zero is reset in step 101. Set 1 to f minus.

Y1 represented by f plus and f minus set here
The factor of the error Y1 is discriminated as described later depending on whether the state of the change of No. 2 continues even when the address i is increased, and the correction term corresponding to it is set.

In the next step 113, the address i is incremented by 1. Therefore, when the process proceeds to step 106 with the address i being zero, the address i is set to 1 here.

When the address i is incremented by 1 in step 113, the process returns to step 102 again, and since the address i is less than 7, the arithmetic processing in steps 103 and 104 is repeated, but in step 105 it is determined that the address i is not zero. By doing so, the process proceeds to step 109 this time.

In step 109, it is determined whether the fplus set when the address i is zero is 1 or zero. When the fplus is 1, the process proceeds to step 110 and y1 (i)- Set y1 (i + 1) to Breg. Also,
When f plus is 0 and f minus is 1,
Proceed to step 111 and set y1 (i + 1) -y1 (i) to Breg
Set to.

Then, in step 112, whether the Breg is positive or negative is determined, and the Bre
When g is positive, the routine proceeds to step 113, the address i is incremented by 1, and the arithmetic processing at steps 102 to 104 is repeated.

That is, when the absolute value of the error rate y1 (i) monotonically decreases in response to the increase change of the fuel injection amount Ti, for example, if f plus 1 is satisfied, then y1 (i) -y1 (i + 1) is always positive. , F
If negative is 1, y1 (i + 1) -y1 (i) should always be positive. Therefore, when it is determined in step 112 that Breg is positive, it indicates that the absolute value of the error rate y1 (i) is monotonically decreasing corresponding to the increase change of the fuel injection amount Ti.

If Breg is positive, the address i is incremented by 1 in step 113, the process returns to step 102, and it is confirmed that Breg is positive until the address i is incremented to 7.

When it is continuously determined that the absolute value of the error rate y1 (i) monotonously decreases in response to the increase change of the fuel injection amount Ti until the address i reaches 7, this time from step 102 to step Proceed to 115.

In step 115, the correction amount Ts based on the battery voltage used when calculating the fuel injection amount Ti is calculated according to the following equation to correct the correction amount n1 for the # 1 cylinder by a fixed amount.

The fuel injection amount Ti is set as the valve opening time ms of the fuel injection valve 6, and in the map of the error rates Yφ, Y1 to Y4, the fuel injection amount Ti when the address i is zero is 0.5 ms, and thereafter the address i It is set to increase by 0.5 ms each time 1 increases. Therefore, (i + 1) × 0.5 ms is the fuel injection amount Ti corresponding to the address i, and corresponds to the error rate y1 (i) in the fuel injection valve 6 of the # 1 cylinder corresponding to this fuel injection amount Ti.

Further, if the fuel for the # 1 cylinder is corrected by a fixed amount, the effect of this correction does not appear when the fuel injection amount Ti is large,
This correction effect becomes more apparent when the fuel injection amount Ti is small, and if there is an excess or deficiency in the correction of a fixed amount, the fuel control error increases as the fuel injection amount Ti decreases. In the normal calculation of the fuel injection amount Ti, the correction amount Ts for correcting the change of the effective valve opening time (opening / closing valve delay time) of the fuel injection valve 6 due to the voltage change of the battery as the driving power source is calculated by the effective injection amount Te. However, when the fuel injection valve 6 deteriorates and the correction amount Ts, which is the constant correction amount, becomes excessive or insufficient, the fuel supply error rate increases as the fuel injection amount Ti decreases as described above. Therefore, the error rate y1
When the absolute value of (i) monotonically decreases in accordance with the increase change of the fuel injection amount Ti, it can be considered that the excess or deficiency of the correction amount Ts is the cause.

Here, the error rate y1 (i) x fuel injection amount Ti is
This corresponds to the excess / deficiency of Ts, and the excess / deficiency of Ts calculated at each address i is averaged in the arithmetic expression of n1.

On the other hand, if it is determined in step 112 that Breg is negative, it indicates that the address i has changed with respect to the changing direction when it is zero, and the absolute value of the error rate y1 (i) monotonically decreases. Since it cannot be said that it shows a change, the process proceeds to step 114 without checking the change tendency until the address i reaches 7.

In step 114, when calculating the fuel injection amount Ti for the # 1 cylinder, a correction coefficient m1 for correcting the effective injection amount Te (basic fuel injection amount Tp) at a constant rate is calculated according to the following formula.

When the absolute value of the error rate y1 (i) does not monotonically decrease in accordance with the increase change of the fuel injection amount Ti and is substantially constant, the effective injection amount
This error rate can be eliminated by correcting Te (basic fuel injection amount p) at a fixed rate.

That is, for example, when one of the plurality of injection holes of the fuel injection valve 6 is clogged, the error rate y1 (i) is substantially constant as the fuel injection amount Ti increases, and the fuel injection amount Ti (valve opening time The actual injection amount for) changes as shown in FIG.
In order to compensate the supply characteristic error due to the clogging of the injection hole, the effective injection amount Te is multiplied by the correction coefficient, and the inclination of the actual injection amount with respect to the fuel injection amount Ti (pulse width) in FIG. 12 is apparently corrected. Just do it.

By the way, the error rate y1 (i) is equal to the effective injection amount Te of the # 1 cylinder.
Is multiplied by a predetermined value Z, but actually, the predetermined value Z-error rate
This shows that the result is the same as when multiplied by y1 (i). Therefore, to actually obtain the desired fuel amount, 1
It suffices to multiply the effective injection amount Te by the error rate y1 (i), add 1 to the average value of y1 (i) at each address i, and add 1 to the effective injection amount Te (basic fuel injection amount Tp The correction coefficient m1 for correcting (1) is set.

In this way, the correction amount n1 for correcting the fuel injection amount Ti of the # 1 cylinder by a constant amount based on the supply characteristic error rate Y1 obtained when the fuel injection valve 6 of the # 1 cylinder is learned, When the correction coefficient m1 for correcting the fuel injection amount Tp at a constant rate is learned, similarly, the correction term n2 for the # 2, # 3, and # 4 cylinders
The learning settings of n4 and m2 to m4 are the same as those in steps 101 to 11 above.
Similar to step 4, each is executed in steps 116 to 118.

Here, the correction terms n1 to n4, m1 to m4 (correction values for each cylinder) that have been learned and set are used for calculating the fuel injection amount Ti for each cylinder in the fuel supply control routine shown in the flowchart of FIG. The fuel injection supply is controlled according to the fuel injection amount Ti learned and corrected according to the supply characteristic errors Y1 to Y4 of the fuel injection valve 6.

The routine shown in the flow chart of FIG. 6 is executed each time the crank angle sensor 14 outputs four reference angle REF signals every 180 ° in the case of four cylinders.

First, in step 131, the reference angle signal REF of this time is # 1.
It is determined whether or not it corresponds to the fuel supply start timing of the cylinder, and if it is for # 1 cylinder, step 13
Go to 2.

In step 132, the F / 1 learning flag FIl is discriminated, and when the F / 1 learning flag FIl is 1 and the learning of the fuel injection valve 6 is not to be performed, the routine proceeds to step 135, where the calculation is made in step 68. Effective injection amount common to each cylinder for normal injection
Te (= 2 x Tp x LMD x COEF x KBLRC x PRFP), the correction terms m1 and n1 learned and set for the # 1 cylinder, and the correction amount Ts set commonly for all cylinders based on the battery voltage The fuel injection amount (fuel supply amount) Ti for the # 1 cylinder is calculated in accordance with the above equation.

Ti ← Te × m1 + Ts + n1 On the other hand, when it is determined in step 132 that the F / I learning flag FIL is zero, the effective injection amount Tedmy (= 2 × Tp × LMD × 1.16) is calculated for the fuel injection amount Ti of the specific one cylinder. ) × COEF × KB
It is time to detect the supply characteristic error of the fuel injection valve 6 of this cylinder by using (LRC × PRFP), so proceed to step 133 and determine whether ncyl is 1 or not, and this time F / I learning It is determined whether it is the turn to learn the fuel injection valve 6 of the # 1 cylinder.

Here, if ncyl is 1, the effective injection amount Tedmy is used to calculate the fuel injection amount Ti of the # 1 cylinder, and the air-fuel ratio of the # 1 cylinder is forcibly displaced, and the result is corrected as expected by the air-fuel ratio feedback correction. Since it is monitored whether the change appears in the coefficient LMD, in step 134, the effective injection amount Tedmy is used to calculate the fuel injection amount Ti for the # 1 cylinder in accordance with the following equation.

Ti ← Tedmy × m1 + Ts + n1 In this way, the fuel injection amount Ti for the # 1 cylinder is set in step 134 or step 135 depending on whether it is the learning period of F / I and whether # 1 cylinder is designated by such learning. When calculated, in step 136, the fuel injection amount T calculated above is calculated.
A drive pulse signal having a pulse width corresponding to i is output to the fuel injection valve 6 of the # 1 cylinder to inject and supply fuel to the # 1 cylinder.

In step 131, the reference angle signal REF of this time is # 1.
If it is determined that it does not correspond to the injection start timing of the cylinder, the routine proceeds to step 137, where the current reference angle signal REF
Is determined to correspond to the injection start timing of the # 2 cylinder.

When the reference angle signal REF this time corresponds to the injection start timing of the # 2 cylinder, is it the learning time of F / I at the same time as the injection start timing of the # 1 cylinder?
Depending on whether the # 2 cylinder is designated by such learning (steps 138 and 139), the fuel injection amount Ti for the # 2 cylinder is calculated in step 140 or step 141, and the calculated fuel injection amount is calculated.
Step drive pulse signal with pulse width equivalent to Ti
At 142, the fuel is output to the fuel injection valve 6 of the # 2 cylinder.

Further, when it is determined in step 137 that the reference angle signal REF this time does not correspond to the injection start timing of the # 2 cylinder,
The routine proceeds to step 143, where it is judged whether or not this corresponds to the injection start timing of the # 3 cylinder.

If this time is the injection start timing of the # 3 cylinder, it is similarly determined whether it is the learning period of F / I and whether the # 3 cylinder is designated by such learning (steps 144, 145), and step 146 or In step 147, the fuel injection amount Ti for the # 3 cylinder is calculated, and in step 148, a drive pulse signal having a pulse width corresponding to the fuel injection amount Ti is output to the fuel injection valve 6 of the # 3 cylinder.

If it is determined in step 143 that it is not the injection start timing of the # 3 cylinder, the injection start timing of this time is the remaining # 4 cylinder. Therefore, is it the learning period of F / I as well?
By this learning, it is determined whether the # 4 cylinder is designated (steps 149 and 150), the fuel injection amount Ti for the # 4 cylinder is calculated in step 151 or step 152, and in step 153 #
A drive pulse signal having a pulse width corresponding to the fuel injection amount Ti is output to the fuel injection valve 6 of four cylinders.

Thus, the supply characteristic error rate of the fuel injection valve 6 for each cylinder
Y1 to Y4 are detected, correction terms n1 to n4, m1 to m4 (correction values for each cylinder) are set so that these error rates Y1 to Y4 are eliminated, and the supply error rates Y1 to Y4 of each cylinder are set. Since the fuel injection amount Ti for each cylinder is controlled on the basis of the fuel injection amount Ti, even if the fuel injection valve 6 of each cylinder has a variation in the supply characteristic, the air-fuel ratio of each cylinder is made to be close to the target air-fuel ratio. It is possible to control, and it is possible to avoid the deterioration of the exhaust property due to the variation of the air-fuel ratio between the cylinders, the occurrence of misfire in a specific cylinder, and the like.

Next, according to the routine shown in the flowchart of FIG. 7, the basic fuel injection amount Tp is corrected by adding the air leakage correction value ΔQ to the intake air flow rate Q, and the effective injection amount Te is calculated by correcting the basic fuel injection amount Tp. The setting control of the fuel supply system correction value PRFP used as the coefficient will be described.

This routine is executed every time the engine 1 makes one revolution. First, in step 181, it is determined whether or not the timer Tmacc is zero. In the routine shown in the flowchart of FIG. 4, the timer Tmacc is set to a predetermined value during transient operation, and when it is zero, it indicates a stable steady operation state.

If it is determined that the timer Tmacc is not zero, then the routine proceeds to step 182, where the steady first time determination flag Ftrm is set to 1
Is set, and this routine is finished as it is.

On the other hand, when it is determined that the timer Tmacc is zero, the routine proceeds to step 183, where the steady-state initial determination flag Ftrm is
Is determined. The flag Ftrm is the timer as described above.
When Tmacc is not zero, 1 is set, so if this determination is the first time, this step 18
If the flag Ftrm is 1 in 3 and proceed to the next step 184.

In step 184, the flag Ftrm is set to zero,
When it is determined in step 183 that the flag Ftrm is zero, this routine is ended as it is, so that the processing from step 184 is performed only at the first time when the timer Tmacc is determined to be zero.

When the flag Ftrm is set to zero in step 184, the fuel injection amount Ti calculated most recently is read in together with the calculation element in step 185. Here, the read fuel injection amount Ti is the correction value m1 to m4, n1 to n4 corresponding to which cylinder.
May be used.

Then, in the next step 186, the air leakage correction is performed in each of the calculation formula of the fuel injection amount Ti read in the current step 185 and the calculation formula of the fuel injection amount Ti read in the previous time (in an operating condition different from this time) in step 185. Only the value ΔQ and the fuel supply system correction system PRFP are unknowns, the air-fuel ratio feedback correction coefficient LMD is assumed to be the reference value 1, and the cylinder-by-cylinder correction values m1 to m4, n1 to n4 are set as correction values for each cylinder. Instead, each average value FIn ← (m1 ＋ m2 ＋ m3 ＋ m4) / 4, Tsln
← (n1 ＋ n2 ＋ n3 ＋ n4) / 4 is substituted and the air leak correction value ΔQ
And two equations with only the fuel supply system correction value PRFP as unknowns are created.

Here, the two equations are set as simultaneous equations so that the two equations can be commonly applied, in other words, the air leak correction value ΔQ and the fuel supply system correction value PRFP that are respectively adapted to two different operating conditions are obtained. .

Therefore, when the basic fuel injection amount Tp is corrected by the air-fuel ratio feedback correction coefficient LMD, the correction by the air-fuel ratio feedback correction coefficient LMD is shared by the air leak correction value ΔQ and the fuel supply system correction value PRFP, The target air-fuel ratio was obtained by the air-fuel ratio feedback correction coefficient LMD until then, so that the target air-fuel ratio can be obtained without the correction coefficient LMD.
And the fuel supply system correction value PRFP are set. The tendency of the air-fuel ratio difference between when an air leak occurs and when the fuel pressure is abnormal is different as shown in FIGS. 13 and 14, one is an addition correction term for the intake air flow rate Q, and the other is a multiplication correction term for it. Therefore, if the simultaneous equations are set under the two different operating conditions as described above, the correction values respectively corresponding to the air leakage and the fuel pressure abnormality can be uniformly set regardless of the operating conditions. Specifically, when air leakage occurs, a fixed amount of correction value ΔQ is required regardless of the operating conditions, and if there is a fuel pressure abnormality, it is necessary to correct the basic fuel injection amount Tp by a fixed rate. Therefore, if simultaneous equations are established under different operating conditions, the correction values ΔQ and PRFP corresponding to these correction demands are set.

As described above, if the arithmetic expression of the fuel injection amount Ti for obtaining the air leakage correction value ΔQ and the fuel supply system correction value PRFP is read only at the first time of the steady operation detection, it is possible to obtain substantially the same operating conditions. It is possible to avoid simultaneous equations being established based on the fuel injection amount Ti below.

In the next step 187, the air leak correction value ΔQ and the fuel supply system correction value PRFP obtained by solving the simultaneous equations in step 186 this time are weighted averaged with the values up to the previous time, and the result of the fuel injection amount Ti is calculated. Set as the final data used in the calculation.

The weighted average calculation of the air leakage correction value ΔQ and the fuel supply system correction value PRFP is performed, for example, according to the following equation, and the weighting weight (weighting for the present data) X used here is used.
Is preferably set to be relatively small so that the air leak correction value ΔQ and the fuel supply system correction value PRFP are updated slowly.

ΔQ ← ΔQ _OLD (1.0-X) + ΔQ new · X PRFP ← PRFP _OLD (1.0-X) + PRFP new · X This is the air leak correction value ΔQ and the fuel supply system correction value PRFP
However, if the change of the air-fuel ratio feedback correction coefficient LMD is followed with good responsiveness, the learning opportunity of the learning correction coefficient KBLRC is lost, and the correction value for obtaining the target air-fuel ratio differs according to the change of the intake air flow rate Q, etc. In addition, the air leak correction value ΔQ and the fuel supply system correction value PRFP change greatly, which lacks control stability, and these correction values are not used only for the intended correction. This is because the accuracy of self-diagnosis based on the value deteriorates.

If the air leak correction value ΔQ and the fuel supply system correction value PRFP are properly learned and set as described above, even if there is leak air that cannot be detected by the air flow meter 13, the amount is corrected by adding a certain amount. In addition, when the fuel having a pressure higher than the intended pressure is supplied to the fuel injection valve 6 due to a failure of the pressure regulator, the basic fuel injection amount Tp is decreased by a predetermined ratio. It is possible to give a desired pulse to the fuel injection valve 6 by giving a drive pulse commensurate with the pressure increase.

Next, if the correction value is set for each factor (for each part) as described above, the fuel injection valve 6 provided for each cylinder,
Since the degree of deterioration of the pressure regulator or the fuel pump, and the degree of increase of the amount of air leaking into the intake system can be specified numerically from the correction degree by the various correction values, the performance shown in the flowchart of FIG. The degree of level reduction is set for each part.

The routine shown in the flow chart of FIG. 8 is executed as a background job (BGL). First, at step 191, the fuel supply system correction value relating to the components of the fuel pressure control system such as the pressure regulator and the fuel pump.
The reference value of 1.0 is subtracted from PRFP, and the correction degree by PRFP is set such that the larger the absolute value is, the larger the correction degree becomes. The degree of correction is expressed in such a manner that the performance level in a fuel pressure control system such as a pressure regulator or a fuel pump is set to zero in a desired state, and its absolute value increases as the deterioration progresses.

In the next step 192, the air leak correction value ΔQ
Is divided by the intake air flow rate Q during idle operation, so that the performance level of the wetting Q is set to zero when there is no air leakage, and the absolute value thereof increases as the leakage amount increases, like the performance level of the fuel pressure control system. Set it so that it becomes larger.

Further, in steps 193-196, each cylinder (# 1 cylinder- #
(4 cylinders), the performance level of the fuel injection valve 6 of each cylinder is set based on the cylinder-specific correction values m1 to m4 and n1 to n4 set to correct the change in the injection characteristic of the fuel injection valve 6. Here, the correction values m1 to m4 are 1 as in the fuel supply system correction value PRFP.
While the correction values n1 to n4 are based on zero, the correction values m1 to m4 are used to convert these to the same unit and make them equivalent. Is set to a performance level based on the correction values m1 to m4, and 1 is subtracted from the value obtained by dividing the correction values n1 to n4 by the complementary voltage component Ts and based on the correction values n1 to n4. Set the performance level.

As a result, the performance level based on the correction values m1 to m4 and the performance level based on the correction values n1 to n4 are set for each cylinder, and one performance level of each fuel injection valve 6 is set. Since it cannot be specified as a numerical value, the square root of the sum of the squared values representing the respective performance levels is calculated, and the result of this calculation is the performance level of the cylinder ← {(m1 ~ m4-1) ² + (n1 ~ n4
/ Ts-1) ² } ^1/2 .

When a plurality of performance levels are set for one component (the fuel injection valve 6 in this embodiment), if a plurality of performance levels are averaged, one deterioration factor may cause the use permission. Even if it progresses to the extent that it exceeds, if other deterioration factors have not progressed, it will be quantified that there is no deterioration that exceeds the usage limit for that part. The sum of the values is calculated, and the square root of the sum represents the performance level of the component, and the performance degradation of the component is determined to be at least the performance degradation due to the factor of the fastest progress of deterioration.

When the performance level (deterioration degree) of each component is specified as described above, the routine shown in the flowchart of FIG. 9 predicts and calculates the travel distance or travel time until the component reaches the usage limit. To display.

In the routine shown in the flowchart of FIG. 9 executed as a background job, first, step 201
Then, the traveling distance 1 (or traveling time) of the vehicle in which the internal combustion engine 1 is mounted is calculated.

Then, in the next step 202, each performance level set in the flowchart of FIG. 8 is stored using the traveling distance 1 (or traveling time) as a parameter (see FIG. 11).

In step 203, the change amount C of each performance level in the latest unit traveling distance (unit traveling time) is calculated.

In step 204, the change amount C calculated in step 203 is calculated.
Then, the travel distance L (or travel time) predicted to be required until each performance level exceeds a preset usable level (deterioration limit level) is calculated. That is, the running distance L (or running time) until the performance level of the part reaches the usage limit is predicted from the recent tendency of change in the performance level. Instead of predicting the subsequent change from the change between the two points as described above, the subsequent change in the performance level may be predicted by curve approximation from the information of three or more points.

In this way, when the travel distance L (or travel time) until the usage limit is reached is calculated for each part, the result is displayed for each part, for example, on the dashboard of the vehicle in the next step 205. However, it should be possible to clearly determine whether the time when maintenance is required for each part is approaching, or whether performance is maintained almost unchanged from the expected state and maintenance is not required for a long time in the future. . In this way, if the travel distance L (or travel time) that can be normally used for each component is displayed, it can be predicted before the component is completely broken down, and the occurrence of inadvertent breakdown can be avoided. Maintenance can be performed only on the parts that really need maintenance.

The display in step 205 does not always have to be performed. For example, it is possible to read it arbitrarily by the driver's switch operation, or a predetermined traveling distance 1 (or traveling time).
You may make it display every. Further, in quantifying the performance deterioration level for each component, it is not limited to the one using the correction value shown in the present embodiment, for example, a correction value for correcting the deterioration of the oxygen sensor 16 is set. However, it is possible to quantify the performance deterioration level using this correction value, and even if the performance deterioration level is not necessarily specified using the correction value, the degree of deterioration of the relevant part ( If it is possible to quantify (detection error, operation error, etc.), it is possible to predict and calculate the travel distance and travel time until the usage limit is reached in the same manner as in the present embodiment.

<Effects of the Invention> As described above, according to the present invention, the vehicle mileage or the traveling time predicted to reach the usage limit of the internal combustion engine component is displayed by predictive calculation based on the change prediction of the performance deterioration. Therefore, it is possible to grasp the deterioration status (performance deterioration level) of each part based on this display and perform accurate maintenance, and prevent the deterioration of drivability due to the occurrence of easy failures. There is.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention, FIG. 2 is a system schematic diagram showing an embodiment of the present invention, and FIGS. 3 to 9 are flowcharts showing control contents in the same embodiment, respectively. The figure is a time chart for explaining the control characteristics in the above-mentioned embodiment, FIG. 11 is a diagram showing a map of the performance deterioration level provided for each part, and FIGS. 12 to 14 are air-fuel ratio deviations by factors. It is a diagram showing a state. 1 ... Engine, 6 ... Fuel injection valve, 12 ... Control unit, 13 ... Air flow meter, 14 ... Crank angle sensor, 16 ... Oxygen sensor

Claims (2)

[Claims] 1. A performance degradation level digitizing means for digitizing a performance degradation level for each predetermined component of an internal combustion engine based on a detected value of an engine operating state related to the component, and the performance degradation level digitizing means. Storage means for storing the digitized performance deterioration level for each part as a parameter of vehicle travel distance or vehicle travel time, and subsequent performance deterioration based on the change rate of the performance deterioration level for each part stored in the storage means A limit arrival prediction calculation means for predicting the progress of a level and predicting and calculating a vehicle travel distance or a vehicle travel time until the part reaches a limit level of performance deterioration based on the prediction result, and the limit arrival prediction calculation means. A component deterioration prediction device for an internal combustion engine for a vehicle, comprising: a display unit that displays the predicted vehicle travel distance or vehicle travel time for each component. 2. When there are a plurality of performance deterioration levels quantified by the performance deterioration level quantifying means for a predetermined component, each numerical value indicating the performance deterioration level is converted into the same unit, and then each numerical value is converted. Calculate the square root of the squared value of
2. A component deterioration predicting apparatus for a vehicle internal combustion engine according to claim 1, further comprising a multi-level processing means for storing the calculation result in the storage means as a numerical value indicating a performance deterioration level of the component.