JPH03124919A - Part deterioration predicting device in internal combustion engine for vehicle - Google Patents

Abstract

PURPOSE:To maintain only necessary parts before they fall in their unusable state by prediction-calculating a running distance on a running time of a vehicle by which parts of an internal combustion engine may reach their using limit levels so as to display the calculated result. CONSTITUTION:In a control unit 12, every prescribed part of an internal combustion engine 1, for example, a performance reducing level of a fuel injection valve 6 is converted into a numerical value on the basis of the detected value in an operating condition concerning the fuel injection valve 6. The performance reducing level which is converted into the numberical value, is memoried for every part with a vehicle running distance or a vehicle running time serving as a parameter. On the basis of a change rate of the performance reducing level for every memorized part, the vehicle running distance or the vehicle running time until the parts reach their limit levels of performance reduction, is prediction-calculatd. The vehicle running distance or the vehicle running time until the pre-calulated performance reducing limit, is displayed for every part by a display means. It is thus possible to maintain only the necessary parts before they fall in their unusable state.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a component deterioration prediction device for a vehicle internal combustion engine, and more specifically, it is capable of predicting and displaying the performance deterioration of each component of the internal combustion engine until it reaches its limit. Regarding such devices.

<Prior Art> In internal combustion engines for vehicles, various devices have been proposed for diagnosing failures in predetermined parts and control systems, and warning of such failures. If the system no longer operates normally, the system automatically diagnoses the occurrence of the failure, notifies the driver by lighting a warning lamp, etc., and shifts to predetermined fail-safe control.

<Problems to be Solved by the Invention> However, although disconnections in signal lines and power supply lines occur on and off, the detection performance of sensors such as oxygen sensors and air flow meters, and the detection performance of fuel injection valves etc. Operating performance gradually deteriorates, and once a certain level of deterioration is exceeded, it tends to become unusable.However, the progression of deterioration as described above can be easily determined by changes in usage time, mileage, etc. It is not determined by the actual product, and it varies greatly depending on the dispersion of parts prices and the environment in which it is used.

Conventional alarm systems are configured to issue an alarm when a component becomes completely unusable, but do not provide any information if the component has deteriorated within the usable range.
Even if it were configured to notify that it is usable but has deteriorated, it would be difficult to judge or instruct the extent of the deterioration, and if the deterioration progresses, it would be necessary to replace the parts, clean the parts, etc. Although it is possible to predict that maintenance will be required, it is unknown when the maintenance will be required, so in reality, warning of deterioration status during the process is useful as maintenance information. I couldn't.

The present invention was created in view of the above problems, and it is possible to display how long it will take for the deterioration of a part to exceed its limit, so that it can be provided as maintenance information before the part becomes completely unusable. The purpose is to enable maintenance to be performed only on necessary parts before they become inoperable.

Therefore, in the present invention, as shown in FIG. 1, the performance degradation level of each predetermined part of the internal combustion engine is quantified based on the detected value of the engine operating state related to the part. a performance deterioration level quantification means; a storage means for storing the performance deterioration level quantified by the performance deterioration level quantification means as a parameter for each part as a vehicle travel distance or a vehicle travel time; A limit reaching prediction calculation means that predicts and calculates the vehicle travel distance or vehicle travel time until the relevant part reaches the limit level of performance deterioration based on the rate of change in the performance deterioration level of each part, and the limit arrival prediction calculation means predicts. A display means for displaying the calculated vehicle travel distance or vehicle travel time for each component is configured to constitute a component deterioration prediction device for a vehicle internal combustion engine.

Here, as shown by the dotted line in Figure 1, when there are multiple types of performance degradation levels for a given part that are quantified by the performance degradation level quantification means, each numerical value indicating the performance degradation level is expressed in the same unit. After the conversion, it is preferable to provide multi-level processing means for calculating the square root of a value obtained by integrating the square values of each numerical value, and storing the calculation result in the storage means as a numerical value indicating the level of performance degradation of the component.

<Operation> According to this configuration, the performance deterioration level quantification means digitizes the performance deterioration level of each predetermined component of the internal combustion engine based on the detected value of the engine operating state related to that component, and converts the quantified performance into a numerical value. The reduction level is stored by the storage means for each part using vehicle travel distance or vehicle travel time as a parameter.

Then, the limit attainment prediction calculating means calculates, based on the rate of change in the performance deterioration level of each component stored in the storage means,
A prediction calculation is made of the vehicle travel distance or vehicle travel time until the part reaches the limit level of performance deterioration. Here, the predictively calculated vehicle travel distance or vehicle travel time up to the performance degradation limit is displayed for each component by the display means.

In this way, the performance deterioration level of each part is stored in correspondence with the vehicle mileage or vehicle travel time, and based on the current rate of progress of performance deterioration, how much remaining travel distance or travel time does the part have to reach its limit? It predicts whether the target will be reached and displays the prediction result.

Further, the multi-level processing means converts each numerical value indicating a level of performance deterioration into the same unit when there are multiple types of performance deterioration levels quantified by the performance deterioration level quantification means for a predetermined part. , the square root of the value obtained by integrating the square values of each numerical value is calculated, and the calculation result is stored in the storage means as a numerical value indicating the performance deterioration level of the part concerned, and multiple types of performance deterioration levels are calculated for the same part. If there is a numerical value to indicate, one numerical value is specified as the performance degradation level of the component from among these multiple types.

<Example> The present invention will be explained in detail below.

In FIG. 2 showing the system configuration of one embodiment, an internal combustion engine 1 mounted on a vehicle has an air cleaner 2, an intake dug 5, 3. Air is drawn in via the throttle valve 4 and the intake manifold 5. A fuel injection valve 6 is provided in a 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 opens when the solenoid is energized and closes when the energization is stopped. Fuel is injected and supplied from the fuel pump F/P and adjusted to a predetermined pressure by the pressure regulator P/H.

Each combustion chamber of the engine l is provided with a spark plug 7, which ignites a spark to ignite and burn the air-fuel mixture. From engine l, exhaust manifold 8. Exhaust duct9. Exhaust gas is discharged via a three-way catalyst 10 and a muffler 11.

The control unit 12 includes a CPU and a ROM.

Equipped with a microcomputer that includes a RAM, an A/D converter, and an input/output interface, it receives input signals from various sensors, processes them as described below, and calculates the fuel provided for each cylinder. Controls the operation of the injection valve 6.

As the various sensors, an air flow meter 13 such as a hot wire type or a flap type is provided in the intake duct 3. Further, a crank angle sensor 14 is provided, and in the case of a four-cylinder engine, outputs a reference angle signal REF for every 180 degrees of crank angle and a unit angle signal PO3 for every 1 degree or 2 degrees of crank angle. Here, the reference angle signal RE
Unit angle signal PO within the period of F or a predetermined time
By measuring the number of occurrences of 3, the engine rotation speed N can be calculated. Further, a water temperature sensor 15 and the like for detecting the cooling water temperature Tw of the water jacket of the engine 1 are provided.

Furthermore, an oxygen sensor 16, which is known as an air-fuel ratio sensor, is provided at the collecting part of the exhaust manifold 8 (the collecting part of the exhaust passages of each cylinder), and detects the air-fuel ratio of the air-fuel mixture taken into the engine 1 via the oxygen concentration in the exhaust gas. Detect.

Further, the throttle valve 4 is provided with a throttle sensor 17 that detects its opening degree TVO using a potentiometer.

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

In this embodiment, the functions as a performance degradation level quantification means, a limit attainment prediction calculation means, and a multi-level processing means are achieved by the programs shown in the flowcharts of FIGS. 3 to 9, and As the means, it is assumed that the RAM of the microcomputer built in the control unit 12 corresponds to t7, and as the display means, for example, a digital display device (not shown) provided near the driver's seat of the vehicle corresponds.

Next, the state of the arithmetic processing of the microcomputer in the control unit 12 will be explained with reference to the flowcharts shown in FIGS. 3 to 9.

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

First, step l (indicated as Sl in the figure).

The same applies below), the detection signal (voltage) output from the oxygen sensor (0□/5) 16 according to the oxygen concentration in the exhaust gas is
/D conversion and input.

In the next step 2, the engine rotation speed N and the basic fuel injection I
For each operating state divided into a plurality of states according to Tp, manipulated variable data is retrieved from a map in which manipulated variables of the air-fuel ratio feedback correction coefficient LMD are stored in advance.

In this embodiment, the correction coefficient LMD is set and controlled by proportional/integral control, and from the map, the rich control ratio PR and the lean control ratio PL are determined.

Each manipulated variable of integral I is searched.

In step 3, the output of the oxygen sensor 16 is compared with a 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.

Here, if it is determined that the air-fuel ratio is rich with respect to the target, the process proceeds to step 4 and the rich initial determination flag fR is determined. The rich initial determination flag fR is set to zero when the air-fuel ratio is lean, so if this is the first rich detection, the rich initial determination flag fR is determined to be zero in step 4.

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

In the next step 6, it is determined whether or not a normal learning counter nl (see FIG. 10), which is set to a predetermined value the first time the transition from transient operation to steady operation, is zero, as will be described later. Normal learning counter n! When is not zero, proceed to step 7 and count down this normal learning counter nl by 1, and in the next step 10 add a set in step 5 to the previous integrated value Σa to update the integrated value Σa. At the same time, the rich initial counter nR is incremented by 1, and the latest value Ti is added to the integrated value ΣTi of the fuel injection fTi to update ΣTi.

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

As will be described later, in the first lean detection, the minimum value of the air-fuel ratio feedback correction coefficient LMD and the fuel injection amount Ti are integrated, and the lean initial counter nL
is now up 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, where the F/I learning flag FIffi for determining the learning period of the fuel injection valve (F/I) 6 is determined. I do.

Here, when the F/I learning flag FIl is O and it is the cylinder-specific learning period of the fuel injector 6, the process advances to step 9, and after the F/I learning flag FI2 becomes 0, the F/I learning (data It is determined whether a timer Tmacc2 (see FIG. 10) for measuring the period during which the sub-ring is prohibited is zero.

When the timer Tmacc2 is not zero, the process jumps to step 10 and proceeds to step 11. However, when the timer Tmacc2 is zero, the process proceeds to step 10, where the LMD maximum value a and the fuel injection amount Ti are integrated, and the rich Increment the initial counter nR by 1.

That is, the normal learning counter n! Until it becomes zero,
F/I learning flag FIj2 is 0 and timer Tmacc
2 is 0, Σa and ΣTi are calculated, and nR is counted up, so that when the normal learning counter n2 is zero and the F/I learning flag FI! is 1, normal learning counter nj2 is zero, and timer T macc
When 2 is not zero, the integration of Σa, ΣTi and nR
The count up is not performed. This is a control that is commonly performed for the integration of Σb and ΣTi and the count-up of nL at the first time of line detection, which will be described later.

In step 11, the lean control ratio PL is subtracted from the previous air-fuel ratio feedback correction coefficient LMD and updated. Next, in step 12, the rich initial determination flag fR is set to 1, while the lean initial determination flag fL set to zero. When the rich state of the air-fuel ratio continues, the rich initial determination flag fR is set in step 4.
When it is determined that is 1, the process proceeds to step 13. In step 13, the air-fuel ratio feedback correction coefficient LMD is updated by subtracting the integral ■ from the previous value.

When the rich state of the air-fuel ratio is eliminated by the reduction of the air-fuel ratio feedback correction coefficient LMD through integral control and the air-fuel ratio is reversed to lean, the process then proceeds to step 14, where the lean initial determination flag fL is determined.

Since the lean first determination flag fL is set to zero in step 12 when the air-fuel ratio is in a rich state, if this is the first lean detection, fL is set to zero in step 14.
A determination is made that L=O. When fL=0, the process 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.

Then, in the next step 16, it is determined whether the normal learning counter nj2 (see FIG. 10) is zero or not in the same manner as in the first rich detection. When the normal learning counter nl is not zero, proceed to step 17 and count down the normal learning counter nl by 1,
In the next step 2o, b set in the step 15
is added to the previous integrated value Σb to update the integrated value Σb, the lean detection counter nL is incremented by 1, and the latest value Ti is added to the integrated value ΣTi of the fuel injection amount Ti to update ΣTi. .

On the other hand, when it is determined in step 16 that the normal learning counter nj2 is zero, the process proceeds to step 18, where the F/I counter nj2 is set to determine the learning period of the fuel injection valve (F/I) 6.
Learning flag FI! Make a determination.

Here, when the F/I learning flag FIj2 is 0 and it is the cylinder-specific learning period of the fuel injection valve 6, step 19
Proceed to F/I learning flag Flf becomes 0, then F/
It is determined whether or not a timer Tmacc2 (see FIG. 1O) for measuring the period during which I learning (data subring) is prohibited is zero.

When the timer Tmacc2 is not zero, the process jumps to step 20 and proceeds to step 21. However, when the timer Tmacc2 is zero, the process proceeds to step 20 to integrate the LMD minimum value and fuel injection lTi, and also Increase the counter nL by 1.

That is, through each of the above calculation processes, the maximum and minimum value data a, 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 reversed when the normal learning counter nl is not zero, Furthermore, even if the normal learning counter n1 is zero, the F/I learning flag Fl
If f is 0 and more than a predetermined time has passed since it became 0, the air-fuel ratio feedback correction coefficient LMD is
The minimum and maximum value data a, b and the fuel injection amount T'i are built up, and the number of rich/lean reversals nR, nL is counted up.

Here, the normal learning counter ni! The data collected when is not zero is during normal fuel control, and F/I
The data collected when the learning flag FIj2 is zero is the data during cylinder-specific learning of the fuel injection valve 6 (fuel supply is controlled by correcting only the air-fuel ratio feedback correction coefficient LMD of a specific cylinder with a predetermined value Z). It is.

In the steering knob 21, the previous air-fuel ratio feedback correction coefficient LMD is updated by adding PR for each rich control ratio, and in the next step 22, the rich initial determination flag fR is set to O.
At the same time, the lean initial determination flag fL is set to 1.

When the air-fuel ratio continues to be lean,
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 previous value of the air-fuel ratio feedback correction coefficient LMD is updated by adding the integral I.

Here, when rich/lean is detected for the first time, calculation processing from step 24 onwards is further performed. In step 24,
Determine the F/I learning flag FIA, and set the F/I learning flag F.
When lf is 1, the process advances to step 25. and,
In step 25, the normal learning counter nf is determined, and if it is not zero, the process is directly terminated, and if it is zero, the process proceeds to step 26.

In step 26, it is determined whether nR and nL, which count the number of rich/lean reversals, are each 8 or not. When it is determined that nR=nL=8, this indicates that the number of air-fuel ratio inversions while the normal learning counter nff1 is counted down from the predetermined value has reached the predetermined number. I Learn the air-fuel ratio feedback correction coefficient LMD before learning.

That is, in this embodiment, when a predetermined time T macc has elapsed after transition from transient operation to steady state, the normal learning counter n! is counted down from a predetermined value until the normal learning counter nl reaches zero, data on the peak values a and b of the air-fuel ratio feedback correction coefficient LMD and the fuel injection amount Ti are collected. The data collected during the next cylinder-specific learning of the fuel injector 6 are compared, and the supply characteristic error of the fuel injector 6 is detected based on the results. =nL=8 indicates that data collection has been completed until the normal learning counter nl reaches zero.

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

Then, in step 29, Σa and Σ sampled until the normal learning counter nl becomes zero
From b, find the average value (Σa/8+Σb/8)/2 of the central value of the air-fuel ratio feedback correction coefficient LMD, and further multiply this average value by the air-fuel ratio learning correction coefficient KBLRC learned for each operating state. The obtained value is set as the initial value ffπφ (value before F/I learning) 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 control related to cylinder-specific learning of the fuel injector 6 is performed. It is learned and memorized 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 are reset to zero, and further, in the next step 31, ΣT
Reset i to zero.

On the other hand, if it is determined in step 26 that nR=nL=8, then step 3
2 and subsequent steps, the learning setting of the air-fuel ratio learning correction coefficient KBLRC is performed.

In step 32, it is determined whether or not nR=nL=O. If it is not zero, this routine is ended as is, and if it is zero, the process proceeds to step 33 and the stored map corresponding to the intake air flow rate Q is From KBL
Search and obtain RC.

In the next step 34, the central value (a + b)/2 of the correction coefficient LMD obtained from the latest values of a and b, which are the upper and lower peak values of the correction coefficient LMD, and the air-fuel ratio learning correction obtained by searching from the map. Based on a predetermined value M, the coefficient KBLRC is weighted averaged according to the following formula, and the air-fuel ratio learning correction coefficient KB is calculated.
Find LRC.

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 a state in which cylinder-by-cylinder learning of the fuel injector 6 is performed, and as will be described later, the fuel injector 6 of a specific cylinder In order to detect the supply characteristic error of , only the air-fuel ratio feedback correction coefficient L MD of the specific cylinder is corrected by a predetermined value Z. Also in this state, data such as Σa, Σb, ΣTi are collected in the same way as when the normal learning counter nj2 is not zero, and nR and nL, which count the reversal of the air-fuel ratio, are counted up from zero.

Therefore, in the next step 38, it is determined whether nR=nL=8, and it is determined whether the air-fuel ratio has been reversed a predetermined number of times or more since learning of the fuel injection valve 6 has started. Here, when it is determined that nR=nL-8 is not the case, the amount of data collected during learning of the fuel injector 6 is small, so the process is terminated. However, when nR-nL=8, the predetermined number of data are collected. To indicate that the information has been collected, the process proceeds to step 39 and subsequent steps.

In step 39, nR and nL, which have been counted up when the F/I learning flag Flff is zero, are reset to zero.

In step 40, the F/I learning flag FII! , is zero and the air-fuel ratio feedback correction coefficient L for a specific cylinder
Correction coefficient Are used to control the actual air-fuel ratio to the target air-fuel ratio when only MD is corrected by the predetermined value Z
g is calculated according to the following formula.

That is, this correction coefficient A reg is the normal learning counter n
! LMDφ used for air-fuel ratio control when not zero
is equivalent to the basic fuel injection amount required to control the average air-fuel ratio of each cylinder to the target air-fuel ratio as a result of correcting only the air-fuel ratio feedback correction coefficient LMD of one specific cylinder with a predetermined value Z. 'rp correction coefficient.

In the next step 41, data Σa and Σb used for the calculation in step 40 at the time of learning of the fuel injection valve 6 are used.
Reset to zero.

In addition, in step 42, the cumulative amount of fuel injection Ti obtained by integrating simultaneously with Σa and Σb is divided by 16, which is the sampling number, and the average value m'r at the time of F/I learning is calculated. 'Set to i.

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

X← ding mφ/ (AregXF/I number - n ding φ (F/I number -
1) 1 That is, in detecting the supply characteristic error of each fuel injection valve 6, calculate the fuel injection 11Ti by multiplying only the air-fuel ratio feedback correction coefficient LMD of one specific cylinder by a predetermined value Z (1, 16), Only one specific cylinder is subjected to fuel control under the fuel injection amount Ti according to the predetermined value Z, and the supply characteristic error of the fuel injection valve 6 is detected based on whether this result appears in the air-fuel ratio feedback correction control as predicted. The arithmetic expression for the above-mentioned X (back-calculated value of the predetermined value Z) is derived as follows.

When correcting the fuel of only one specific cylinder, assuming that air-fuel ratio feedback correction is performed for that cylinder alone, the correction coefficient will be 11ff compared to the air-fuel ratio correction coefficient TTdφ before fuel correction.
When it reaches φ/Z, the correction of the air-fuel ratio feedback correction coefficient LMD based on the predetermined value Z is canceled and the air-fuel ratio should return to the target air-fuel ratio. On the other hand, fuel correction is not performed for other cylinders whose air-fuel ratio feedback correction coefficient LMD is not corrected to the predetermined value Z, so even if feedback correction is performed for each cylinder alone,
The air-fuel ratio correction coefficient ■πdφ does not change. By the way, since the air-fuel ratio feedback correction based on the detection of the oxygen sensor 16 is to control the average air-fuel ratio of all cylinders to the target air-fuel ratio, the air-fuel ratio feedback correction coefficient LMD of only one specific cylinder is corrected. The fuel ratio correction coefficient Tπ■ (the correction coefficient obtained by multiplying the air-fuel ratio feedback correction coefficient LMD and the air-fuel ratio learning correction coefficient KBLRC) should be obtained as the average 1σ 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 T'T required to control the air-fuel ratio to the target air-fuel ratio is as follows.

Here, when the air-fuel ratio feed fluctuation correction coefficient LMD of only one specific cylinder is corrected by the predetermined value Z, the air-fuel ratio correction coefficient required to control the air-fuel ratio to the target air-fuel ratio is Ar.
Since this A r is found in step 40 as eg,
The predetermined value Z can be calculated backwards by substituting eg into rVd in the above formula, and this backward calculation formula is the calculation formula for X described above. For example, there should be a difference between the predetermined value Z and the value X, which is the value obtained by back calculating the predetermined value Z using the above formula, but if there is a difference between the two, the fuel injection of the cylinder with fuel correction This indicates that the valve 6 does not accurately inject fuel commensurate with the correction by the predetermined value Z, and the amount of supply characteristic error in the relevant cylinder is detected according to the difference.

Therefore, in the next step 44, the difference Y (←1.
16(Z)-X). 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 expected amount, X becomes 2 smaller than the predetermined value Z. Therefore, in this case, Y is a positive value, and although Y is an error rate, it can be regarded as a value that should be corrected for that cylinder.

In step 44, Y corresponding to the fuel supply characteristic error of the cylinder corrected this time was calculated, so in the next step 45, F/
Set the I learning flag FIE to 1 and proceed to the next step 46.
Now reset ΣTi to zero.

Furthermore, in step 4'7, it is determined whether the air-fuel ratio correction coefficient A reg obtained in step 40 and the initial value φriφ obtained in the normal fuel control state before learning of the fuel injection valve 6 are substantially equal. . Since the air-fuel ratio correction coefficient Areg is the data when the fuel of one specific cylinder is corrected, it is normal for it to change from the initial value of 11mmφ, and even though the fuel of one specific cylinder is corrected, the air-fuel ratio If the correction coefficient does not change, it is presumed that the drive control of the fuel injection valve 6 for that cylinder is impossible due to a circuit break or short circuit.

For this reason, when it is determined in step 47 that τ■dφ=A reg, there is an abnormality in the fuel injector 6 of the cylinder for which the fuel correction was performed, so the correction for which F/I learning was performed in step 48 is determined. Cylinder number ncy! The fuel injection valve 6 of the cylinder corrected in steps 49 to 52 is abnormal (
NG) is displayed on the dash board of the vehicle, for example.

On the other hand, when it is determined in step 47 that LMDφ = Areg, although there is a supply characteristic error, it is not possible to immediately determine whether there is an abnormality in the fuel injection valve 6. Therefore, in steps 53 to 59, the currently detected supply characteristic error rate is determined. Y is made to correspond to the fuel injection amount mTi and stored for each cylinder.

In step 53, it is determined whether ncyffi, in which the number of the cylinder whose fuel is to be corrected for F/I learning, is set, is 1, and nc>! ! is 1, the error rate Y obtained in step 44 is calculated as the error rate Y1 of the #1 cylinder corresponding to the average fuel injection amount mTi obtained in step 42.
is stored as map data.

If it is determined in step 53 that ncyn is not 1, it is determined in step 55 whether or not ncyj2 is 2, and ncyj2 is determined to be 2.
When cyl=2, the process proceeds to step 56, and the error rate Y obtained in step 44 is stored as map data for storing the error rate Y2 of the #2 cylinder in correspondence with the average fuel injection amount mTi.

Furthermore, if it is determined in step 55 that ncyl=2, it is determined in step 57 whether ncyf is 3 or 4, and if ncyl is 3, step 5
At step 8, store Y in the error rate ¥3 map for #3 cylinder.
ncyl! When is 4, Y is stored in the error rate Y4 map for the #4 cylinder in step 59.

In this way, if the error rate Y detected for each cylinder is stored in correspondence with the fuel injection amount mTi for each cylinder, the error rate ¥1 to Y4 of the fuel injection valve 6 of each cylinder will be the same as that of the fuel injection amount Ti. In order to be able to determine how the change is occurring and to perform the desired fuel supply control in each cylinder based on this, what kind of correction should be made to the calculation of the fuel injection amount Ti for each cylinder? It can be determined whether or not to apply the same treatment, and it can also be used as a material for diagnosing abnormality (degree of deterioration) 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, and is executed every 10 m5. first,
In step 61, the opening degree TVO of the throttle valve 4, the engine rotation speed N, the intake air flow rate Q, etc. are input.

In the next step 62, the engine rotation speed N and the intake air flow f
The basic fuel injection amount Tp (←KX(Q+ΔQ)Q/N; K
is a constant). Note that the air leak correction value ΔQ is
This is to correct the amount of leaked air that leaks into the engine intake system downstream of the air flow meter 13 and is not detected by the air flow meter 13.

In step 63, the opening degree change rate ΔTV per unit time is
It is determined whether O is substantially zero. When ΔTVO is approximately zero and the opening degree is approximately constant, step 6
In step 4, it is determined whether the rate of change ΔN of the engine rotational speed N, which is obtained in the same manner as ΔTVO, is approximately zero.

When it is determined in step 64 that the rate of change ΔN is approximately zero, it is assumed that the engine 1 is in a steady operating state and the process proceeds to step 65.

On the other hand, if at least one of ΔTVO and ΔN is approximately zero (or is fluctuating), the engine 1 is assumed to be in a transient operating state and the process proceeds to step 67.

At step 67, a predetermined value is set in a timer Tmacc that measures the time elapsed since transition from transient operation to steady operation. When transitioning from transient operation to steady operation, it is determined in step 65 whether or not the timer Tmacc is zero, and if it is not zero, step 6
The process advances to 6 and the timer Tmacc is counted down by 1.

Therefore, the timer Tmacc becomes zero after a predetermined time period corresponding to the predetermined value set in step 677 and the execution cycle of this routine has elapsed after it is determined that the engine 1 is in steady operation. , even if the steady operation of the engine l is determined, until the timer Tmacc reaches zero, air-fuel ratio fluctuations during transient operation will have an effect. F/I learning is performed only during stable steady operation that has elapsed (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 (error detection) of the fuel injection valve 6 are calculated according to the following 2.

Te”2XTpXLMDXCOEFXXBLRCXPR
FPTedmy← 2X T p X (LMDXl, 16) XC0EF
X KBLRC This is the air-fuel ratio learning correction coefficient. Moreover, PRFP is a fuel supply system correction value set in the flowchart of FIG. 7, which will be described later.
When the pressure of the fuel pumped to is no longer the initial value,
This pressure abnormality can be compensated for. Furthermore, C0EF
are 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, for the normal effective injection fTe, the learning effective injection 1iTedm of the fuel injection valve (F/I) 6
In the calculation formula for y, the air-fuel ratio feedback correction coefficient LMD
is multiplied by a predetermined value Z=1.16, and by applying this effective injection amount Tedmy only to one specific cylinder during the learning period of the fuel injection valve 6 where the F/I learning flag Flf is zero, By forcibly changing the fuel injection amount Ti of one cylinder and monitoring the change in the air-fuel ratio feedback correction coefficient LMD, which shows the effect of the change, the effective injection tTedm
This is to detect the supply characteristic error of the fuel injection valve 6 of the cylinder to which y is applied.

In step 69, it is determined whether the timer T macc is zero. If the timer T macc is not zero, the engine 1 is in a transient operating state or not in a stable steady operating state, so the process proceeds to step 70 .

In step 70, a transient flag F acc for determining transient operation of the engine 1 is set to 1. In the next step 71, the F/I learning flag FII2 is set to 1 to prohibit F/[learning.

Further, in step 72, the normal learning counter n1 is set to a predetermined value 16, nR and nL that count the number of rich/lean reversals are reset to zero, and the peak value of the air-fuel ratio feedback correction coefficient LMD is integrated. ΣTi, which integrates Σa, Σb, and fuel injection ITi, is reset to zero.

On the other hand, when it is determined in step 69 that the timer T macc is zero, the process proceeds to step 73 where the transient flag F acc is determined. The transient flag F a
Since cc is set to 1 when Tvaacc≠0, the first time when Tmacc=0,
At this step 73, it is determined that Facc=1, and the process proceeds to step 74.

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

Then, in the next step 76, it is determined whether or not ncyf, which specifies the cylinder number to be learned, is 4, and the ncyf
When yi is 4, in step 77 ncyI! , is set to 1 so that the learning for the fuel injector 6 of the #1 cylinder is performed, and when ncyl is not 4, ncyl is increased by 1 in step 78 and the learning is performed for the fuel injector 6 of the #1 cylinder.
#3. Learning is performed for any fuel injector 6 of the #4 cylinder. Therefore, the cylinder in which the fuel injection valve 6 is to be learned is
That is, the switching is made sequentially each time stable steady-state operation is detected for the first time.

In the next step 79, it is determined whether the normal learning counter n2 is zero. When the normal learning counter nl is not zero, a predetermined value 200 is set in the timer Tmacc2 at step 80, and when the normal learning counter n1 is zero, step 80 is performed.

At step 81, it is determined whether or not the timer Tmacc2 is zero, and if it is not zero, the process proceeds to step 82, where the timer 'f' macc2 is decreased by one.

The normal learning counter n! Σa in the normal fuel control state based on the effective injection amount Te while counting down from a predetermined value to zero.

Data such as Σb is obtained, and then only the fuel injector 6 of one specific cylinder is controlled based on the effective injection iiTedmy, and new data such as Σa and Σb are obtained during the 20F/I learning period.
The effective injection amount Tedmy
Since the air-fuel ratio feedback correction coefficient LMD is not stable in the initial state when the timer Tmacc2 is used,
Σ in the F/I learning state in the time measured by
Collection of data such as a, Σb, etc. is prohibited (see FIG. 10).

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

This routine is executed as a background job (BGJ), and first, in step 101, the supply characteristic error rate Yl-Y4 of the fuel injection valve 6 stored for each cylinder corresponding to the fuel injection amount mTi is calculated. (Step 5
3 to step 59) is less than tMN with respect to the increase in the fuel injection amount Ti, and resets the flags f plus and f minus to zero, and Reset i, which specifies the map addresses of Y1 to Y4, to zero.

Then, in the next step 102, it is determined whether the address i is 7 or less, and if it is 1-7, the process proceeds to step 103.

In step 103, the error rate Yl when learning the fuel injector 6 of the #1 cylinder is stored in the address i of the fuel injection tmTi grid from the map stored corresponding to the fuel injection amount mTi. Read the data and set the value to yl (i).

Further, in step 104, the data stored in the address i+1 next to the address i in step 103 in the map of Yl is read out, and the value is set as yl (
i+1).

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

Then, when yl(0) is large, ste, yb10
Proceed to step 7 and set 1 to f plus which has been reset to zero in step 101. If yl(1) is large, proceed to step 108 and set 1 to f minus which has been reset to zero in step 101. do.

y expressed as f plus and f minus set here
Depending on whether the change in l continues even when the address i is increased, the cause of the error Y1 is determined as described later, and a corresponding correction term is set.

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

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

In step 109, it is determined whether f plus set when address i is zero is 1 or zero, and when f plus is 1, the process advances to step 110 and yl (i) yl (i-1-1) B re
Set to g. Further, when f plus is 0 and f minus is 1, the process advances to step 111 and yl
Set (i+1)-yl (i) to B reg.

Then, in step 112, it is determined whether the B reg is positive or negative, and if B reg is positive, the process proceeds to step 113, where the address i is incremented by 1, and again in step 102.
- Repeat the arithmetic processing in step 104.

That is, when the absolute value of the error rate yl (i) monotonically decreases in response to an increasing change in the fuel injection amount Ti, for example, if r plus is 1, yl (i) yl (i+1) is a constant pressure, If f minus is 1, yl (i+1
) yl (i) should be the constant pressure. Therefore, when it is determined in step 112 that B reg is positive, this indicates that the absolute value of the error rate yl(i) is monotonically decreasing in response to an increasing change in the fuel injection amount Ti.

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

When it is determined that the absolute value of the error rate yl(i) monotonically decreases in response to the increase in the fuel injection amount Ti until the address i reaches 7, the process proceeds to step 102.
The process then proceeds to step 115.

In step 115, a correction amount n1 for correcting the correction numerator s based on the battery voltage used when calculating the fuel injection -1iTi by a certain amount for the #1 cylinder is calculated according to the following formula.

Σ (i+1) Xo, 5ms Xy 1 (i
) nl= The fuel injection amount Ti is set as the valve opening time ms of the fuel injection valve 6, and in the error rate Yφ and the map of Yl to Y4, the fuel injection lTi when the address i is zero is 0.5 m.
s, and from then on, every time address i increases by 1, it increases by 0.5 ms. Therefore, (i +1) Xo,
5 ms is the fuel injection amount T1 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.

In addition, if the fuel for the #1 cylinder is corrected by a certain amount, the effect of this correction will not be apparent when the fuel injection amount Ti is large, but the effect of this correction will become more apparent when the fuel injection amount Ti is small. If there is an excess or deficiency in the amount correction, the smaller the fuel injection amount Ti is, the larger the fuel control error will be. In the normal calculation of the fuel injection amount Ti, the correction numerator s to correct the change in the effective valve opening time (opening/closing valve delay time) of the fuel injection valve 6 due to the voltage change of the battery, which is the driving power source, is set to the effective injection iTe. I am trying to add it, but
When an excess or deficiency occurs in the correction numerator s, which is the lever constant correction amount, due to deterioration of the fuel injection valve 6, the fuel injection N
Since the fuel supply error rate increases as Ti decreases, if the absolute value of error rate > +1 (i) monotonically decreases in response to increasing changes in the fuel injection amount Ti, it is determined whether the correction numerator s is excessive or insufficient. can be considered to be the cause.

Here, the error rate yl (i)
The excess or deficiency of the TS calculated at each address i is averaged.

On the other hand, if it is determined in step 112 that B reg is negative, this indicates that the address i has changed from the direction of change when it is zero, and the absolute value of the error rate y1 (i) is simple. Since it cannot be said that ff1il shows a small change,
The process proceeds to step 114 without checking the change trend until address i reaches 7.

In step 114, when calculating the fuel injection flTi for the #l cylinder, the effective injection amount Te (basic fuel injection 1T
A correction coefficient ml for correcting p) at a constant rate is calculated according to the following 2.

m1=1+ When the absolute value of the error rate yl(i) does not monotonically decrease as the fuel injection amount Ti increases and is substantially constant, the effective injection 1Te (basic fuel injection ip) is corrected at a constant rate. This error rate can be eliminated.

That is, for example, if one of the plurality of injection holes of the fuel injection valve 6 is clogged, the error rate yl(i) is approximately constant as the fuel injection amount Ti increases, and the error rate yl(i) is approximately constant as the fuel injection amount Ti (valve opening time )
The actual injection amount changes as shown in FIG. 12, so in order to compensate for the supply characteristic error due to the clogging of the nozzle hole, the effective injection amount Te is multiplied by a correction coefficient to change the amount shown in FIG. 12. The apparent slope of the actual injection amount relative to the fuel injection amount Ti (pulse width) may be corrected upward.

By the way, the error rate yl(i) is the effective injection i of #1 cylinder
This shows that even though Te is multiplied by the predetermined value Z, the result is actually the same as when multiplied by the predetermined value Z - error rate yl (i), so the desired fuel amount is actually obtained. To do this, it is sufficient to multiply the effective injection lTe by 1 + error rate y1(i), and add 1 to the average value of yl(i) at each address i to calculate the effective injection lTe of #1 cylinder (basic fuel injection ff1Tp). ) to set a correction coefficient ml.

In this way, based on the supply characteristic error rate Y1 obtained when learning the fuel injection valve 6 of the #l cylinder, the correction bone n1 that corrects the fuel injection NTi of the #1 cylinder by a constant amount and the basic fuel Once the correction coefficient ml for correcting the injection amount Tp at a constant rate is learned, #2. #3. #4 cylinder correction terms n2 to n4. Learning settings m2 to m4 are executed in steps 116 to 118, respectively, in the same manner as steps 101 to 114.

Here, the learning set correction terms n1 to n4. m1~m4
(Cylinder-specific correction value) is used to calculate the cylinder-specific fuel injection amount Ti in the fuel supply control routine shown in the flowchart of FIG.
The fuel injection supply is controlled in accordance with the fuel injection amount Ti that has been learned and corrected according to No. 4.

The routine shown in the flowchart of FIG.
This is executed every time the F signal is output.

First, in step 131, the current reference angle signal REF
It is determined whether or not the timing corresponds to the fuel supply start timing for the #1 cylinder. If it is for the #1 cylinder, the process advances to step 132.

In step 132, the F/I learning flag Fil is determined, and if the F/I learning flag Fl is 1 and it is time not to perform learning of the fuel injection valve 6, the process proceeds to step 135, and in step 68, the F/I learning flag Fil is determined. The calculated effective injection common to each cylinder for normal injection lTe (=2xTpXLMDXCOE
FXKBLRCxPRFP), the correction terms m and n1 learned and set for the #1 cylinder, and the correction numerator s that is set commonly for all cylinders based on the battery voltage, according to the following formula, the fuel injection amount for the #1 cylinder ( Calculate Ti (fuel supply amount).

Ti+-TeXml+Ts+n 1 On the other hand, when it is determined in step 132 that the F/I learning flag Fll is zero, effective injection amount Tedmy (=2xTpx
LMDxl, 16)XCOEFXKBLRCXPRFP
) to detect the supply characteristic error of the fuel injection valve 6 of this cylinder, the process advances to step 133 and the nc
Determine whether yl is 1 or not, and in this F/I learning #
It is determined whether it is the order to learn the fuel injection valve 6 of one cylinder.

Here, if ncyl is 1, the effective injection ilTedmy is used to calculate the fuel injection amount Ti for the #1 cylinder, and the air-fuel ratio of the #1 cylinder is forcibly shifted, and this result is predicted to be the air-fuel ratio feedback correction coefficient. Since it is monitored whether or not it appears in the change in LMD, in step 134, the effective injection amount T
Using edmy, calculate the fuel injection amount T i for #1 engine according to the following formula.

Ti4-TedmyXml+Ts+nl Thus, F
/I learning period, and depending on whether the #1 cylinder is specified in such learning, the fuel injection amount Ti for the #1 cylinder is calculated in step 134 or step 135. In step 136, the above calculation is performed. fuel injection
A drive pulse signal having a pulse width corresponding to i is outputted to the fuel injection valve 6 of the #1 cylinder to inject and supply fuel to the #1 cylinder.

Further, if it is determined in step 131 that the current reference angle signal REF does not correspond to the injection start timing of the #1 cylinder, the process proceeds to step 137 and the current reference angle signal REF is determined to be the one that does not correspond to the injection start timing of the #2 cylinder. Determine whether it corresponds to the period.

Then, when the current reference angle signal REF corresponds to the injection start timing of the #2 cylinder, it is determined whether it is the F/I learning period, as in the case of the injection start timing of the #1 cylinder, and whether such learning Depending on whether #2 cylinder is specified (steps 138 and 139), fuel injection f for #2 cylinder
ilTi is calculated in step 140 or step 141, and a drive pulse signal having a pulse width corresponding to the calculated fuel injection amount Ti is outputted to the fuel injection valve 6 of the #2 cylinder in step 142.

Furthermore, in step 137, the current reference angle signal REF is #
If it is determined that the timing does not correspond to the injection start timing for the second cylinder, the process proceeds to step 143, where it is determined whether the timing corresponds to the injection start timing for the #3 cylinder.

If this is the time to start injection for #3 cylinder, the F/I
It is determined whether it is the learning period and whether the #3 cylinder is specified in such learning (steps 144 and 145).
In step 146 or 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 NTi is output to the fuel injection valve 6 of the #3 cylinder. .

In addition, when it is determined in step 143 that it is not the injection start time for the #3 cylinder, the current injection start time is the remaining #4 cylinder.
Since it is a cylinder, it is similarly determined whether it is the F/I learning period and whether the #4 cylinder is specified in such learning (steps 149 and 150), and in step 151 or step 152, it is determined whether the #4 cylinder is specified. Calculate the fuel injection amount Ti for
In step 153, a drive pulse signal having a pulse corresponding to the fuel injection NTi is outputted to the fuel injection valve 6 of the #4 cylinder.

In this way, the supply characteristic error rates Y1 to Y4 of the fuel injection valve 6 are detected for each cylinder, and the correction terms n1 to n4 are set so that the error rates Y1 to Y4 are eliminated. ml-m4 (correction value for each cylinder) is set, and the fuel injection amount Ti for each cylinder is controlled based on the fuel injection amount Ti corresponding to the supply error rate Y1 to Y4 of each cylinder. Even if there are variations in the supply characteristics of the injection valves 6, the air-fuel ratio of each cylinder can be controlled to be close to the target air-fuel ratio, and variations in the air-fuel ratio between cylinders can cause deterioration in exhaust properties and misfires in specific cylinders. etc. can be avoided.

Next, according to the routine shown in the flowchart of FIG. 7, the air leak correction value ΔQ, which is added and corrected to the intake air flow IQ in calculating the basic fuel injection amount Tp, and the effective injection amount Te are used to calculate the basic fuel injection amount 'rp. Setting control of the fuel supply system correction value PRFP used as a correction coefficient will be explained.

This routine is executed every time the engine 1 rotates once. First, in step 181, the timer T ma
It is determined whether cc is zero or not. Said timer T
In the routine shown in the flowchart of FIG. 4, macc is set to a predetermined value during transient operation, and when it is zero, it indicates a stable steady operation state.

Here, if it is determined that the timer Tmacc is not zero, the process proceeds to step 182 and the steady initial determination flag F
Set trm to 1 and end this routine.

On the other hand, when it is determined that the timer T macc is zero, the process proceeds to step 183 and the steady initial determination flag F trm is determined. The flag F trm is
As mentioned above, when the timer T macc is not zero, ■ is set, so if this determination is the first time, the flag F trm is set to 1 in step 183.
If so, proceed to the next step 184.

In step 184, the flag F trm is set to zero, and when it is determined in step 183 that the flag F trm is zero, this routine is immediately terminated, so that the processing from step 184 onwards is performed as follows.
This is only the first time that the timer T_macc is determined to be zero.

When the flag F trm is set to zero in step 184, the most recently calculated fuel injection lTi is read together with its calculation element in the next step 185. Here, the fuel injection amount Ti to be read is the correction 4 corresponding to which cylinder.
im 1~m4. It may be possible to use n 1 to n 4.

Then, in the next step 186, this time step 185
In each of the calculation formula for the fuel injection amount Ti read in step 185 and the calculation formula for the fuel injection ITi read in last time (under operating conditions different from this time) in step 185, only the air leak correction value ΔQ and the fuel supply system correction value PRFP are unknown. In addition, the air-fuel ratio feedback correction coefficient LMD is assumed to be the standard (li!1), and the cylinder-specific correction values m1 to m4 are
．． Instead of nl to n4 being correction values for each cylinder, the respective average values Fln←(ml+m2+m3+m4)/4. Tsln
By substituting ←(nl+n2+n3+n4)/4, two equations are created in which only the air leakage correction value ΔQ and the fuel supply system correction (ii P RF P are unknowns).

Here, the two equations are set as simultaneous equations, and the air leak correction value ΔQ and the fuel supply system correction value PRFP are determined so as to be commonly compatible with the two equations, in other words, to be compatible with the two different operating conditions. .

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
The air leakage correction value ΔQ and the fuel supply system correction value PRF
P, and the target air-fuel ratio was previously obtained by the air-fuel ratio feedback correction coefficient LMD, but now the air leak correction value ΔQ and the fuel supply system correction value are changed so that the target air-fuel ratio can be obtained even without the correction coefficient LMD. PRFP is configured. The tendency of air-fuel ratio deviation is different when an air leak occurs and when fuel pressure is abnormal, as shown in FIGS. 13 and 14. One is an additive correction term for the intake air flow rate Q, and the other is a multiplication correction term for this. Therefore, by setting simultaneous equations under two different operating conditions as described above, correction values corresponding to air leakage and fuel pressure abnormality can be uniformly set regardless of the operating conditions. Specifically, when an air leak 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 ITp by a fixed percentage. Therefore, if simultaneous equations are set up under different operating conditions, correction values ΔQ and PRFP that meet these correction requests can be calculated.
is set.

In addition, if the calculation formula for the fuel injection amount Ti for determining the air leak correction value ΔQ and the fuel supply system correction value PRFP is read only at the first time of steady operation detection as described above, the road-to-road driving conditions can be adjusted. It is possible to avoid creating simultaneous equations based on the fuel injection amount Ti under .

In the next step 187, the air leak correction value ΔQ obtained by solving the simultaneous equations in the above step 186 is calculated.
and the fuel supply system correction value PRFP are each weighted averaged with the previous value, and the result is set as the final data used in the calculation of fuel injection 4]Ti.

The weighted average calculation of the air leak correction value ΔQ and the fuel supply system correction value PRFP is performed, for example, according to the formula shown below, and the weighting weight (weighting for this data) used here is made relatively small, and the air leak correction is performed. It is preferable that the value ΔQ and the fuel supply system correction 4fiP RFP be updated slowly.

ΔQ←ΔQota(1,0−X')+ΔQ,,,w・X
PRFP=PRFPo+, ++(1,OX)+PRFP
,,, ・X This means that the air leakage correction value ΔQ and the fuel supply system correction value PRFP are equal to the air-fuel ratio feedback correction coefficient L.
If the change in MD is followed with good response, the learning correction coefficient KB
When the LRC learning opportunity is lost and the correction value for obtaining the target air-fuel ratio differs depending on changes in the intake air flow itQ, etc., the air leakage correction value ΔQ and the fuel supply system correction value PRFP change significantly. This is because the accuracy of self-diagnosis based on these correction values deteriorates because these correction values are not used only for the intended correction, and the stability of control is lost.

The air leak correction value ΔQ and the fuel supply system correction value PRFP
If the learning settings are properly set as described above, even if there is leakage air that cannot be detected by the air flow meter 13, it will be possible to correct it by adding a certain amount of air leakage, and also to compensate for the leakage air that cannot be detected by the airflow meter 13. When fuel with a pressure higher than the pressure is supplied to the fuel injection valve 6, the basic fuel injection 1tTp is reduced by a predetermined ratio and a driving pulse commensurate with the pressure increase is given to the fuel injection valve 6. Desired fuel can be injected.

Next, if correction values are set for each factor (for each part) as described above, the fuel injection valve 6 provided for each cylinder,
The degree of deterioration of the pressure regulator or fuel pump, as well as the degree of increase in the amount of air leaking into the intake system, can be quantified and identified from the degree of correction by the various correction values described above. Set the level reduction degree for each part.

The routine shown in the flowchart of FIG. 8 is executed as a background job (BGL),
First, in step 191, a reference value of 180 is subtracted from the fuel supply system correction value PRFP related to fuel pressure control system components such as pressure regulators and fuel pumps, and PR
The degree of correction by FP is set with zero as a reference, and as the absolute value increases, the degree of correction increases.

The degree of correction is expressed by setting the performance level of a fuel pressure control system such as a pressure regulator or a fuel pump to zero in the initial state, and increasing its absolute value as deterioration progresses.

In addition, in the next step 192, by dividing the air leakage 2 correction value ΔQ by the intake air flow rate Q during idling operation, the performance level of the leakage Q is determined by dividing the air leakage 2 correction value ΔQ by the intake air flow rate Q during idling operation. When there is no leakage, it is set to zero, and the absolute value is set to increase as the leakage amount increases.

Further, in steps 193 to 196, based on cylinder-specific correction values m1 to m4 and nl-n4 set for each cylinder (#1 cylinder to #4 cylinder) to correct changes in injection characteristics of the fuel injection valve 6, The performance level of the fuel injection valve 6 of each cylinder is set. Here, the correction values m1-m4 are correction values having a reference value of 1 like the fuel supply system correction value PRFP, whereas the correction values n1-n4 are correction values having a reference value of zero. , In order to convert these into the same unit and make them equivalent values, a reference value 1 is subtracted from the correction values m1 to m4 to set a performance level based on the correction values m1 to m4, and the correction value n1xn4 is converted to a voltage. 1 from the value divided by the correction numerator S
A performance level based on the correction value n1xn4 is set by subtracting .

As a result, a performance level based on the correction values m1 to m4 and a performance level based on the correction values n1 to n4 are set for each air conditioning, respectively, and the performance level of each fuel injector 6 is set as one. Since it cannot be specified numerically, find the square root of the sum of the squared values of the numerical values representing each performance level, and use this calculation result as the performance level of the cylinder ← ((m1 to m4-1)
2+(nl-n4/Ts 1)”) ”” and Zr
.

When multiple performance levels are set for one component (in this example, the fuel injector 6), for example, if the multiple performance levels are averaged, one deterioration factor may cause the permissible use. Even if the deterioration has progressed to the extent that it exceeds the usage limit, if other deterioration factors have not progressed, it will be quantified that there is no deterioration that exceeds the usage limit for that part, so as mentioned above, the square of each performance level The sum of the values is calculated, and the square root of the sum represents the performance level of the part, so that the deterioration of the performance of the part is determined to be at least greater than the deterioration caused by the factor whose deterioration progresses most rapidly.

Once the performance level (degree of progress of deterioration) of each part is specified as described above, the routine shown in flowchart 1 in Figure 9 determines the distance or time required for that part to reach its usage limit. Perform predictive calculations and display.

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

Then, in the next step 202, the distance traveled is determined! Each performance level set in the flowchart of FIG. 8 is stored using (or running time) as a parameter (see FIG. 11).

In step 203, a change meter C of each performance level in the recent unit traveling route F4 (unit traveling time) is calculated.

In step 204, 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 from the change 1c calculated in step 203. . That is,
Based on recent trends in performance level changes, it is possible to predict the mileage or travel time until the performance level of the component reaches its service limit. Note that instead of predicting subsequent changes from changes between two points as described above, subsequent changes in performance level may be predicted by curve approximation from information on three or more points.

In this way, when the travel distance L (or travel time) until the usage limit is reached for each part is predicted and calculated, in the next step 205, the results are displayed for each part on the dashboard of the vehicle, for example. , it is possible to clearly determine whether each part is nearing its time to require maintenance, or whether the performance remains almost the same as the initial state and no maintenance will be required for a long time in the future. Make it. In this way, if the mileage L (or mileage) that can be normally used for each part is displayed, it is possible to predict the failure of that part before it occurs, and avoid the occurrence of unexpected failures. Maintenance can only be performed on parts that truly require maintenance.

Note that the display in step 205 does not need to be performed all the time; for example, it may be read out at any time by the driver's switch operation, or it may be displayed every predetermined travel distance (or travel time). Furthermore, in quantifying the level of performance degradation for each component, the correction value is not limited to that shown in this embodiment, and for example, a correction value for correcting deterioration of the oxygen sensor 16 may be set. In a motor vehicle, the level of performance degradation can be quantified using this correction value, and the degree of deterioration of the relevant part ( If the detection error, operation error, etc.) can be quantified, 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 this embodiment.

<Effects of the Invention> As explained above, according to the present invention, the vehicle travel distance or travel time at which the parts of the internal combustion engine are predicted to reach their usage limit is calculated and displayed. Understand the deterioration status of parts (performance decreases and bells),
This has the effect of making it possible to perform accurate maintenance and preventing deterioration of drivability due to the occurrence of difficult failures.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a system schematic diagram showing an embodiment of the present invention, FIGS. 3 to 9 are flowcharts showing control details in the above embodiment, and FIG. The figure is a time chart for explaining the control characteristics in the same embodiment as above, Figure 11 is a line diagram showing a map of performance deterioration levels provided for each component, and Figures
FIG. 4 is a diagram showing the state of air-fuel ratio deviation depending on each factor.

Claims (2)

[Claims] (1) A performance deterioration level quantification means for quantifying the performance deterioration level of each predetermined part of the internal combustion engine based on the detected value of the engine operating state related to the part; storage means for storing the performance deterioration level for each part as a parameter of vehicle mileage or vehicle travel time; and a storage means for storing the performance deterioration level of the part concerned based on the rate of change in the performance deterioration level for each part stored in the storage means. A limit attainment prediction calculation means for predicting and calculating the vehicle travel distance or vehicle travel time until reaching the level, and a display means for displaying the vehicle travel distance or vehicle travel time predicted and calculated by the limit arrival prediction calculation means for each part. A component deterioration prediction device for a vehicle internal combustion engine, characterized in that it is configured to include the following. (2) When there are multiple types of performance degradation levels for a given part that are quantified by the performance degradation level quantification means, after converting each numerical value indicating the performance degradation level into the same unit,
Claim 1, further comprising a multi-level processing means for calculating the square root of a value obtained by integrating the square values of each numerical value, and storing the result of the calculation in the storage means as a numerical value indicating a level of performance degradation of the component. The component deterioration prediction device for a vehicle internal combustion engine described above.