JPS6338649A - Fuel control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve control precision under the transient state of an air-fuel ratio, by a method wherein a fundamental injection amount responding to an air amount is computed from the opening of a throttle valve corrected according to a difference there-between and the number of revolutions, and is corrected by means of a feedback correction amount and a fuel delay correction amount. CONSTITUTION:Detecting values from a throttle valve opening sensor 25, a crank angle sensor 32, a water temperature sensor 33, an O2 sensor 34 are inputted to a control device 35. The control device 35 corrects the opening of a throttle valve in a way to add a value, obtained by multiplying a difference value between a present detecting value and a preceding detecting value from the throttle valve opening sensor 25 by an injection delay factor, responding to a waiting time during a time between weighing of an air amount and injection of fuel and the moving time of injection fuel. From the corrected opening of the throttle valve, table lookup is made on a flow passage area, and the value is divided by the number of revolutions to compute an air amount. A fundamental fuel injection amount responding to the air amount is corrected based on a fluctuation in an mount of fuel adhered to an intake air system and a detecting value from an O2 sensor 34.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a fuel control device for an internal combustion engine.

(Prior Art) Electronically controlled fuel injection engines are actually widely used due to their high fuel metering accuracy, and when controlling the amount of injection supplied from the injector to the engine intake system, the engine load (for example, intake air Basic fuel injection amount (basic pulse width) T p (= K-Q a/N
, where K is a constant. ) is corrected according to other operating variables. Injection + fit (injection pulse width) "i" is calculated based on the following equation (1) (for example, published by Railway Former Head Office, November 1985) “Self! I! JulL Engineering: 1
FI (see Vol. 34, No. 11, f: tS28i, etc.).

Ti=TpXCOEFXLAMBDA+'l's...
(1) However, COE is the sum of various correction coefficients LAMB.
DA: air-fuel ratio correction coefficient 'Fs: invalid pulse width (problem to be solved by the invention) By the way, a device in which one or more fuel injectors are attached to a gathering part of the intake passage far away from the engine shilling force ( In the 1sPI device (hereinafter referred to as "1sPI device"), the injection pulse width control is affected by errors from measuring the intake air amount to fuel injection amount measurement and errors due to the fuel delay 1, and this is due to the control accuracy of the injection pulse 11G. This will reduce the

For example, even if the amount of air QAINJ passing through the fuel injection valve is measured and the injection pulse width is calculated based on this air kIQAINJ, there will be a time delay between the measurement of QAINJ and the time when fuel is injected and supplied. Therefore, when QA I N J increases or decreases as during a transient period, the amount of fuel injected decreases or increases due to the delay.

This time delay is due to the injection wait from the metering of QAINJ until the fuel injector starts injection, due to the injection pulse width, due to movement of the injected fuel, etc. (hereinafter collectively referred to as "injection delay"). Yes, even if the measurement accuracy of QA I N J is increased, it cannot be addressed.

Therefore, for example, acceleration +1. For the FF, the set air-fuel ratio is set to the rich side to increase the amount of fuel, but this will lead to deterioration in fuel consumption and exhaust emissions.

In addition, in the SPI system, some of the injected fuel adheres to the inner wall surface of the intake pipe and intake boat before reaching the shilling, or fuel that is floating in the intake pipe without being sucked (in these intake systems) The behavior of the amount of adhering fuel and floating fuel (hereinafter collectively referred to as the "adhering amount") greatly affects the control accuracy of the air-fuel ratio.

Various correction methods have been proposed for this fuel delay, but none of these directly deals with the amount of fuel adhering to the intake system, but instead detects and corrects factors that affect the amount of adhering fuel. Therefore, there is no choice but to increase the number of conditions for determining whether correction is necessary or not.

Therefore, an attempt is made to eliminate M by matching the error caused by the injection delay and the error caused by the fuel delay, but in the engine for White! Flj 111, which has a wide range of operating conditions, Since it is not possible to determine which error is the cause of the error, an attempt to improve control accuracy will increase the number of matching steps.Furthermore, compromising accuracy to a certain extent will inevitably result in poor drivability.

In order to improve the accuracy of air-fuel ratio control, it is necessary to consider the error due to the injection delay and the error due to the fuel delay separately, and unless they are separated, the correction content will be ambiguous.

It is an object of the present invention to solve these problems and provide a fuel control device with improved air-fuel ratio control accuracy.

(Means for Solving the Problems) In the present invention, as shown in FIG. , comprising means 3 for detecting the engine rotation speed, and means 5 for calculating the amount of air passing through the fuel injection valve section from the correction metering valve opening statement and the engine rotation speed, and calculating a target air-fuel ratio. means 8, means 6 for calculating the basic fuel injection amount from the passing air amount and the target air-fuel ratio, means 9 for calculating the feedback correction amount based on the deviation between the target air-fuel ratio and the actual air-fuel ratio, and the operating state. A means 1 () for calculating a fuel delay correction amount based on the feedback correction amount and a fuel delay correction amount, and a means 11 for calculating the fuel injection amount by correcting the basic injection amount based on the feedback correction amount and the fuel delay correction amount.

Note that 1 is a means for detecting operating conditions including 2.3, and 7 is a means for detecting an actual void ratio.

(Function) With this configuration, the amount of air passing through the injection valve part Q
Since AINJ is calculated with high accuracy and the throttle valve opening α is corrected during transient periods, the air M corresponding to the injection delay is
QAIN can be determined and, assuming there is no fuel delay, accurate control to the target air-fuel ratio is possible. However, the target air-fuel ratio is obtained at the injection valve, and the amount of air-fuel deposited may vary by the time it is injected into the engine cylinder. A deviation from the standard air-fuel ratio may occur. The cause of this deviation is fuel delay, and this is corrected by the correction amount K A T I (OS) for the fuel delay.

In other words, in this invention, since the air amount meter is designed to calculate the error associated with fuel injection and the error associated with fuel delay separately, when matching, each of them has to be considered separately. As a result, the matching becomes (￥锇), which increases the accuracy of correcting both the injection delay and the fuel delay, and provides a flat air-fuel ratio characteristic regardless of the transient state.

This will be explained below using examples.

(Example) In FIG. 2, one fuel injection #24 is provided in the intake passage 22 upstream of the intake throttle valve 21 to cover all cylinders (SPI device).
It also shows the mechanical configuration when the present invention is applied to an engine in which the throttle valve opening α (also referred to as TVO) is used as the engine load number instead of the air amount in order to simplify the device.

Therefore, in this example, the injection pulse width is controlled using the throttle valve opening degree α and the engine speed N as basic variables (hereinafter, this will be referred to as the α-N method).

Therefore, an air amount sensor is not provided, and a throttle valve opening sensor 25 is provided instead.

In addition, two idle-up solenoid valves (referred to as S■) 26 and 27 are provided in parallel in the passage 23 that bypasses the throttle 9 valve 21 in order to enhance control at the time of starting. A swirl control valve 28 is provided.

The engine speed N is determined by the crank angle sensor 32 built into the distributor 31, and the cooling water temperature TW is determined by the water temperature sensor 3.
3, there is no difference from the conventional device, such as the provision of an oxygen sensor 34 as a sensor for detecting the actual air-fuel ratio, and these crank angles No. 43 (reference signal and angle signal),
The water temperature signal and the actual air-fuel ratio signal are input to the throttle valve (along with the degree signal) 351: Input 3, and the optimal fuel injection pulse width Ti is calculated in the control unit 35 based on these signals.

In other words, the characteristic part of this invention is this injection pulse width.
This will be explained with reference to FIG. 3 (consisting of FIG. 3(A) to FIG. 7(C)) to FIG. 7. The details of these are as follows: Fig. 3 shows the main routine for calculating the injection pulse width, and Figs. 4 to 7 show the variables used in the main routine (fuel delay correction amount KATHO3).
, feedback correction, ILAMBDA, E[air-fuel ratio T
This is a subroutine for determining the intake air temperature correction coefficient KTA), and the numbers in the figure are process numbers. Such control can be easily performed by configuring the control unit 35 with a microcomputer. In this case, the calculation of each variable is executed in the control cycle shown in the table below.

First, the routine shown in FIG.
This corresponds to the function of 5.6.11.

Here, in a device in which the injection valve is attached to a suction boat near the engine cylinder, the amount of air passing through the injection valve part QAINJ1. is similar to the SPI device. :On the other hand, there is a time delay associated with fuel injection from the injector, and in the SPI system, there is a supply delay before the fuel injected from the injector reaches the shilling.In this invention, these two points have been taken into account. This is what I did. However, by calculating each separately instead of treating them as one, it is possible to simplify the concept and clarify whether the control error 'N' is due to the injection amount metering delay or the fuel delay. That's what I do.

This greatly improves the accuracy during setting, but if there is a change over time or a difference in fuel properties after the revision, these become factors that reduce accuracy. Therefore, a learning function is added to deal with these factors.

Expressing this mathematically, the effective pulse width 'c is the following formula (
3) (step 73). In addition, assuming that the invalid pulse width is Ts, the sum with Te is Ti (='re+Ts)
, −χ remains the same as before (steps 72 and 73).
).

Te=(TpXKBLRC+KATHO8X K B
T L RC) X L A M 13 D A...
(3) However, Tp: 1 basic pulse K A T H○S: Basic fuel delay correction amount (transient correction amount) LAMBDA: Feedback correction amount (air-fuel ratio correction coefficient) K B L RC: Basic injection amount learning correction coefficient KBTLR
C: Fuel delay learning correction coefficient. Here, T11 is used as the basic pulse width as in the conventional example, but its content is calculated using the following equation (4), unlike the conventional example.

TI）”QA I N J Xi″L” B Y A
X K (4) where QAINJ: Injector air amount (g) TFBYA: [1 to standard air-fuel ratio: constant (ms/g) based on the injector characteristics.

First, the air in the injection valve section is 'ff1QA+NJ, but since it is difficult to directly obtain this in this embodiment which does not have an air amount sensor, it is obtained based on Q c v L. In other words, QAINJ is QCYL and its change ff1
dQcYL/dt (C is a coefficient).

QA I N J =Q cy t, +c-dQ c
y L /dt (5) The second equations equivalent to this equation (5) are the following equation group (6Δ) to (6F).

QA I N J G = QA I N
J (!XKl'A - (68) QA I
NJc=QcyLXVCYL+DCM
...(6B) QCYL=QllXK2 +Q CY L -I X(2 to 1)...(6C) Qo=Q++o XKFLAT -(6D
)DCM=(Qcy L QCYL-1)X K I
X Trcr ・=(61E) K T A
＝ KTA OX KTA Q c Y L・
...(6F) However, QAINJG: Injection valve air amount / Schilling (lbi) QAINJ (!: Injection valve air amount / Schilling (cc) Air amount to QCYL Nijiring, / Schilling volume (%) VCYL Nijiring volume (cc) DCM: Manifold air change amount (cc) KTA: Intake temperature correction coefficient (mg/cc) QH: Equilibrium air amount/Schilling volume (%) QCYL-1: Previous performance f7: QC of L4f
YLK2: Rate of change in QCYL/Equation Q o o: Linearization air volume/Schilling volume (%
) KFLAT Nearat air-fuel ratio coefficient (%) K1: Manifold coefficient Tref: Ref signal period (μ5) KTAO: Basic intake temperature correction coefficient (+ng/cc) KTA
QCYL: Load correction rate (%) for intake temperature correction.

These second groups (6^) to (6F) are double-pressed due to various corrections and standardizations (converted to per shilling, shilling volume of light, etc.), but the basic for,
QAINJC is determined by the sum of a steady term (QCYLXVc y +-) and a transient term (DCM).

However, since this value QAINJC is in volume units, it can change due to one change in intake air temperature, so KTA is converted into units of 10 cm by adding a correction coefficient (steps 64 to 6).
6).

Also, Q c Y L 1. Weighting using tK2 as a smoothing constant, Q+zQcyL-+ as a variable, and K2 as a weight is determined by the average value (steps 57 to 60)
.

Next, the variable (N II O, KL'LAT k!?) is determined from the flow path area of the intake system. Therefore, the flow path area is determined by the following equations (6G) and (611) (steps 41 to 55).

AADNV=AAXTref/VCYL-(6G
) AA=A α + AI+A ノ～C...(
6+1) However, l\ADNV: Channel area/(rotation speed x
Schilling volume) (Cm2/rpmφCC) A i ~: Total flow path area (CI112) Aα: Throttle valve flow path area (Cm2) AI: 5V26 flow path area (Cm2) AAC: 5V27 flow path area (C1112) be.

By the way, the throttle valve flow path area Aα is obtained from a table using the throttle valve opening degree α as a parameter.
) (steps 42 to 44).

Δα=α−α−1...(7A) α,=α+Δα×a...(7B) However, Δα: Difference value of throttle valve opening α α−1: α at previous detection αY: After correction Aperture '#opening a; injection delay coefficient.

This injection delay coefficient a can be determined by experiment and may be a fixed constant, but the injection delay is determined by the waiting time Tt from the measurement of the air to the injection of the fuel, the travel time TV of the injected fuel, and the injection delay. The total pulse width is 1 o'clock ('I' l: + i', 10 i'
, ) by the calculation period r, the injection delay coefficient U
You may also ask for

In this example, the flow path surface IAα is based on the corrected throttle valve 1jH degrees αY (step 45).
, if there is a passage 23 that bypasses the throttle valve 21,
It is necessary to consider these areas AI and AAC,
Therefore, the total flow area AA is the flow area Aα based on the throttle valve opening and the flow area of the bypass passage (AI or AAC).
) (steps 45 to 52). Note that these 5V213 and 27 are two-position valves. This is to reduce costs by performing four-step control instead of using an electromagnetic switch for duty control.

In addition, in actual control, the value AA/
N (corresponding to the AAXTref part in step 55) is adopted. If AA is used as it is, it will have a region that changes suddenly with changes in N, so if this is used as a parameter, the accuracy will decrease in this sudden change. However, for example, increasing the number of grid points in a map in order to improve accuracy also increases the computation time accordingly. Therefore, by adopting AA/N, these control problems were solved.

Therefore, this AADNV(=AAXTrcf/VC
Linearized air ′+1Q110 is determined using (YL) (step 56), and the flat air-fuel ratio coefficient K
F L A T is obtained from the map using QIIO,N as parameters (step 57).

In addition, the basic intake temperature correction factor IKTAO and the intake temperature load correction factor KTAQ CYL are also calculated based on the intake temperature TA.
, Q(:YL) are searched as parameters, and KTA is determined by the product of these (steps 81 to 83 in the tPJ7 diagram).

Since the air amount Qa I N J of the injection valve section has been determined by the above calculation, the next step is to determine the correction amount regarding the fuel delay. This correction amount is KAT HOS used in step 69, and is specifically calculated by the routine shown in FIG. This corresponds to the function of means 10 in FIG.

In this example, it is determined based on the deviation between the adhesion amount M F H of intake system fuel under steady-state operating conditions and the actual adhesion amount MF during transition. Expressing this numerically, the following equation group (8^) ~ (8
E).

K A i' HOS = V MF
X G HE・' ... (88) VMF
=(Mt”H-MF-1)XKMF... (
8B) ML'=ME'-+ 10 VMF...
(8C) K M F = (K M F A 'r +
K MF V MF )X K MF N
K M F D BT...(8D) G [(t' = G H[' Q c
Y L X G HF F B
Y A... (8E) However, K A 'r HOS: JM supplement jTlμ3)
V M l”: Deposition speed (μS/spray) M Fll
: Equilibrium adhesion amount (μS) MF: Adhesion ff1 (μS) M E' -H: +nf calculations, 7) MFK
M l;'' Bi-part ratio (%) K M FA T: Basic ratio (%) K M 11'
V MF: Adhesion speed correction wheel for quantity ratio (%) KMFN: Rotation correction rate for quantity ratio (%) KMFDBT:
Boost correction factor (%) of quantity ratio GHF: correction factor (%) GHFQCYL: deceleration correction factor (%) GHFFBYA: air-fuel ratio correction factor (%).

In other words, the adhesion speed VMF is determined by the difference between the equilibrium adhesion amount M F H and the previously calculated adhesion amount MF-1 (M F H - MF
-1) by a coefficient KMF representing the rate at which MP approaches per unit period (step 103).

Here, since MFH depends not only on the basic operating variables QA+NJyN but also on the cooling water temperature 'r..., there are a total of three parameters, and since there is one parameter too many, it cannot be used as a three-dimensional map as it is. Therefore, in this example, this problem is solved by a combination of three-dimensional map search and linear approximation interpolation calculation. That is, there are n (=4 or 5) different reference temperatures Tlll set in advance within the range of temperature changes that can actually be detected by the cooling water temperature Tw.
0~'1゛Taguchi (Tso.〉...〉]゛QAI to Taden n
Using NJ and N as parameters, n pieces of adhesion amount data are prepared by actual measurement to which the adhesion amount MFHTwo at the base temperature Twn is attached. Then, the reference temperature 1'wk (k is an integer from O to 11) above and below the actual water temperature TIII, Tw
Attachment fifM F HTWk, M F at k+1
Using H'f''wk+1, Tub.

M F H is finally determined using an interpolator using 'I' uhk and i' uhk + 1 (step 101).

Note that high accuracy can be obtained with the method using maps and interpolation calculations, but if you want to increase the calculation speed even if the accuracy is moderate, there is also a method that uses two tables.
This is shown in the following equation (8F).

M F' HTu+n=M F HQnXM
F HNn... (8F) However, M F H
Qll: Coefficient M i′:′H based on QA I N J
N++: Coefficient based on N, M F HQ n
is determined by table search using QAINJG, M F HN, and N as a parameter.

Note that interpolation calculation cannot be performed when Tub>Two and Tw<Tub mouth, so MFH=
Let MFHTwo. Also, during fuel cut, MF
H= F CM F I ((constant value).

On the other hand, the MF used this time is a value obtained by adding the VMF obtained this time to the previous MF (MP-1) (step 104).

Next, the quantity ratio KMF may be a constant value, but in this example, the basic value K M F A 'r is determined by map search using AADNV and Tw as parameters, and then ■MF, N
, the amount of change in boost pressure is corrected based on the bypass value DBO8T (step 102).

That is, there are three correction coefficients KMFVMF, KMFN for the basic value KMFAT.
, KMFDBT, and these are introduced so that the air-fuel ratio at the initial stage of the transient has a flat characteristic. In other words, there is a slight lack of correction during slow acceleration, and slight deviations occur when conducting experiments, such as l) errors due to differences in rotation speed, and we are trying to eliminate these individually. be.

In addition, the bypass value DBO3T is calculated using the following formula (8G) to (8I)
The content is a value that gradually decreases in synchronization with the Ref signal.

(1) When setting (first time) D 130 S T = D B OS T -10 (B
OO8T-BOO3TO) ... (8G) (2) At decay (DBO8'r≧0) (second time onwards) DB
O8T=DBO3T-l
O3"f'=DBO3T-I
S T-1: +if times operation operation BO3T TGEN: addition J! ! Attenuation coefficient (constant) TGENG:
Damping coefficient (constant) during deceleration (nao, 7'-s) ffE
BOOS T HA A A D N V wo, and the adhesion speed correction factor of the quantity ratio KMFVMF is VMF-,
The rotation correction factor KMFN of the portion ratio is N, and the boost correction factor of the portion ratio K M F D B T +, t 1DBO
It can be found by table search using 6T+ as a parameter.

Next, the correction factor GHF is a value that eliminates differences in fuel properties, etc. (step 105). This is due to the fact that highly volatile fuel rapidly vaporizes and is inhaled into the engine due to the development of suction negative pressure during deceleration. becomes less.

Therefore, during deceleration, it is necessary to estimate the amount of addition 'Xi to a smaller value, and conversely, it is sufficient to assign a smaller value to the correction coefficient (Gl (FQcYL). In other words, during acceleration (when VMF is positive) is not corrected (G
HF Q c Y L = 1.0), during deceleration (V
If MF is negative), a value of 1 or less is used. Note that the correction is also made according to the target air-fuel ratio TFBYA, and the deceleration correction factor GHFQCYL is Qc
Y L is the air-fuel ratio correction factor G) (FFBYA is T E”
It is determined by table search using B Y A as a parameter.

Using the VMF and GHF thus obtained, the transient correction amount K A T HOS is finally obtained (step 10G).

Next, step 71. of fjS3 diagram (C). ．． The feedback correction amount LAMBDA and the target air-fuel ratio 1'' FBYA used in step 67 are also calculated in the conventional example, and their routines are shown in FIGS. They respectively correspond to the functions of means 8 and 9 in the figure.

That is, LAMBDA is a correction coefficient in air-fuel ratio feedback control. Figure fj55 is an example of PID control, in which the deviation between the actual air-fuel ratio (specifically, the oxygen sensor output Ip) and the single value of the air-fuel ratio (specifically, the sensor output equivalent of the target value is T r P) The following formula (
LAMBDA is obtained in steps 9^) to (9D) (steps 111 to 118).

LAMBDA=P+I+D・(9A)P
=KP-ER...(9B) ■Two I -+ + K+ ・ER...(9C)
D=Kl)・(IER-ER-1)...(9
D) However, KP: Proportional gain, 1: Integral gain, KD: Differential gain, -1: ■ at the time of song repetition, and ER-+: ER of Moe repetition calculation.

Note that the deviation ER is given by the following formula (north) (step 1
14).

ER=rp TIF-(mouth+1)
...(9E) However, n is the Qi f2 number.

Here, the second term of the opening formula (9E) is R
The sensor output ■p when the ef signal is input is shown. This is done in consideration of the fact that there is a time delay before the result of the air-fuel ratio set in the intake system is detected by the sensor 34 provided in the exhaust system, and the phases must be matched.

Further, the target air-fuel ratio TFBYA is calculated using Tu++QcyLtN as a parameter (step 9 in the fjS6 diagram).
1-95). Note that step 95 in the same figure is TF[3YA
It has an upper limit value and a lower limit value, and is given the function of a 7-else 7.

Next, in step 68.70 of FIG. 3(C), Sarel'T: Xi correction staff IKBLRC, KBTLRC,
In this example, since the air M (QA I N J ) and the fuel delay correction amount (K A THOS ”) are calculated separately, the learning correction can also be performed separately and independently. In other words, the basic injection amount learning correction coefficient KBLRC is calculated using the feedback correction ILAMBDΔ calculation routine, and the fuel delay learning correction coefficient KBTLRC is calculated using the transient correction amount K.
Calculated by the AT HOS calculation routine (5th
Steps 119 and 120 in the diagram, step 10 in the vJ4 diagram
7-110).

Learning correction basically adds a control term based on the deviation from the target value in advance to prevent deviation from occurring during the next calculation.KBL RCif LA
M B D A, K I3 T L RC is this L
AMBDA, actual air-fuel ratio AFBYA, and target air-fuel ratio T
is calculated based on the deviation B of FBYA (step 1
19, 120.107-110).

In addition, by comparing the adhesion speed VMF with the reference value L1, it is determined that the steady state (VMF<Ig) is the transient state (MF≧L+)
Then, learning is performed for KBL RC only during steady state and for KBTLRC only during transient state (steps 119, 107).

Next, to explain the operation of this embodiment, errors in injection pulse width control include errors associated with injection amount metering delays and errors associated with fuel delays, and especially in SP■, unless these are taken into account, high accuracy is required. can't get it. In this example, the amount of air in the injector is calculated accurately based on the opening of the throttle valve, and the amount of air corresponding to the injection delay is determined during transient periods, so the air-fuel ratio is accurate even if there is no fuel delay. Determined by Since a deviation actually occurs due to fuel delay, this deviation is corrected by fuel delay correction. That is, in this embodiment, there is no impact on the injection flow.
f
In order to distinguish between Q and Q, we decided to treat these separately, and as a result, it is only necessary to consider each separately when matching, making it easier to match and allowing each to be matched with high accuracy. As a whole, it is possible to maintain high air-fuel ratio control regardless of the position of the injection valve or operating conditions.

For example, the amount of air in the injection valve QA I N J calculated based on the throttle valve opening α is calculated by the amount of air QA I N J increases or decreases.

Therefore, the throttle opening α is corrected by the difference value Δα and the injection delay coefficient a, and QAINJ is calculated based on the corrected throttle valve IJ11 degrees αY.

αY=α+Δσ×a...(7B) Therefore, since the fuel injection and the air fittingQA+NJ passing through the injection valve part match, there is no need to set the set air-fuel ratio to the rich side during acceleration, for example, and the target air-fuel ratio is adjusted to the target air-fuel ratio. It becomes possible to control accurately.

In addition, in the SPI device, there is a problem of fuel delay during transient periods, but this is due to the amount of adhesion of intake system fuel (MI'H, MF
) by directly specifying the transient fuel lag correction IK.
Since ATHO8 is calculated, it is not the adhesion amount itself (compared to indirect correction based on factors that affect the adhesion amount, matching is easier, and various I
I! It is possible to prevent the complexity of control caused by

Control speed is also an issue, especially during transient times, and the more complex the control, the lower the speed, so this has important implications as it relates to cost.

In this way, this embodiment simplifies the approach by separating the injection amount metering delay and the fuel delay.
Since the matching has become easier than in the second example, it is possible to obtain each of them more precisely, and as a result, it is possible to improve the control accuracy of the air-fuel ratio. Here, improved accuracy leads to improved drivability, and there is no need to provide a large margin as in the conventional example, so it is possible to improve fuel efficiency and exhaust emissions.

However, no matter how accurate the settings may be, it is impossible to deal with error factors (changes over time, differences in fuel properties, etc.) after the revision.

Therefore, the learning function is activated for error factors after the initial revision. That is, since the error from the target air-fuel ratio TFBYA is eliminated each time learning is performed, control to the target air-fuel ratio can always be performed in the same state as initially set, and control accuracy after the initial revision can be maintained at a high level. Can be done.

Note that this invention allows the SPI device and the EGI device to be used in common, and has the effect that the number of development steps can be reduced.

(Effects of the Invention) As explained above, in this invention, the air-fuel ratio can be accurately determined when there is no fuel delay by correcting the throttle valve opening according to the difference value and determining the amount of air in the injector. Set the air-fuel ratio properly, and then adjust the air-fuel ratio by the difference due to the fuel delay.
4. Since the correction is based on the delay, it is possible to clearly distinguish whether the error in control accuracy is due to the delay in injection amount metering or the delay in fuel flow, making it easier to match. Therefore, it is possible to improve accuracy and improve drivability.

[Brief explanation of drawings]

Figure 1 is a conceptual configuration diagram of this invention, Figure fjfj2 is SP■
A schematic diagram showing the mechanical configuration of an embodiment of the present invention applied to a device, FIG. 3 (!@3 (A) to Pt53 (C)
Consisting of ) to FIG. 7 are flowcharts illustrating the contents of operations executed within the control unit in FIG. 2. DESCRIPTION OF SYMBOLS 1... Operating state detection means, 2... Throttle valve [■ degree detection means, 3... Engine rotation speed detection means, 4... Throttle valve opening correction means, 5... Injection valve air Quantity calculation means, 6...
- Basic injection amount calculation means, 7...Actual air-fuel ratio detection means, 8
. . . Target air-fuel ratio calculation means, 9 . . . Feedback correction amount calculation means, 10 . . . Fuel delay correction amount calculation means, 1
1... Injection amount calculation means, 21... Intake throttle valve, 22
...Intake passage, 23...Bypass passage, 24...
Fuel injection valve, 25... Throttle valve opening sensor, 26.27
...Solenoid valve for idle up, 34...Oxygen sensor, 35...Control unit. (Masu Juru) Figure 6 Figure 7

Claims (1)

[Claims] means for detecting the throttle valve opening, means for correcting the throttle valve opening according to the difference value, means for detecting the engine speed, and a fuel injection valve based on the corrected metering valve opening and the engine speed. means for calculating the amount of air passing through the section;
means for calculating a target air-fuel ratio; means for calculating a basic fuel injection amount from the amount of passing air and the target air-fuel ratio; and means for calculating a feedback correction amount based on a deviation between the target air-fuel ratio and the actual air-fuel ratio. , comprising a means for calculating a fuel delay correction amount based on the operating state, and a means for determining the fuel injection amount by correcting the basic injection amount based on the feedback correction amount and the fuel delay correction amount. Fuel control device for internal combustion engines.