JPS6390639A - Fuel injection controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To aim at the promotion of flatness in an air-fuel ratio irrespective of a warm-up state, by detecting both warm-up and load states of an engine, while operating a correction factor on the basis of at least the correction value to which these detected result are given as a parameter, and compensating the transient correction quantity. CONSTITUTION:A balancing quantity of sticking fuel to a suction system and floating fuel is operated by a balancing quantity operational device (c) on the basis of each output of an engine driving state detecting device (a) and a warm-up state detecting device (b), and a differential valve between this balancing quantity and a predictive parameter of these sticking and floating fuel quantities to the suction system at that time is operated by a differential value operational device (d). And, a correction factor is operated by a correction factor operational device (e) in accordance with the correction value to be found out of both warm-up and load states, and the differential value is compensated by this correction factor, then a transient correction quantity is operated by a transient correction quantity operational device (f), while this time predictive parameter is operated by a predictive parameter operational device (g) on the basis of the last transient correction quantity and the last predictive parameter. And, a fundamental supply to be operated on the basis of an engine driving state is compensated on the basis of the transient correction quantity and a final fuel supply is operated by a supply operational device (h), thus a controller is constituted so as to control a fuel supply device (i).

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a fuel injection control device for an internal combustion engine such as an automobile, and particularly to a device that determines an optimal fuel injection amount by correcting the basic injection amount according to the engine operating state during a transient period. (Prior art) In general, the deviation of the air-fuel ratio from the target air-fuel ratio during engine acceleration/deceleration is mostly due to quantitative changes in adhering fuel and floating fuel adhering to the intake manifold and intake ports of the intake system. The amount of adhering and floating fuel varies greatly depending on the operating condition of the engine. Further, the amount of adhering and floating fuel does not change stepwise in response to changes in operating conditions, but changes with a certain delay, and the time constant of this delay is also not constant. Furthermore, changes in adhesion and floating fuel amount are
It depends not only on changes in operating conditions, but also on the magnitude of the difference between the amount at that point and the amount in the equilibrium state (steady state). Therefore, as a conventional example, changes in adhesion and floating fuel are approximately determined from changes in intake pipe pressure and accelerator opening during a transient period, and the fuel injection amount is increased for acceleration and deceleration, and at the same time when the engine is warmed up. In JP-A Nos. 58-144632 and 58-14.46, the correction coefficients for acceleration increase and deceleration decrease are further corrected using a correction factor according to the cooling water temperature.
No. 34, No. 58-144636, No. 58-14463
No. 7 and No. 58-150033, each publication). By the way, the present applicant has developed a system that can be accurately controlled under all acceleration/deceleration conditions, including transient conditions as described above, and can reduce matching time by minimizing complex corrections such as further corrections of various correction coefficients. A device that can do this has already been applied for (Japanese Unexamined Patent Publication No. 6
No. 0-243605). In this earlier application, the transient correction iDM required when calculating the actual injection amount (final injection amount) Ti is calculated by correcting the adhesion of the intake system and the equilibrium amount Mφ corresponding to the equilibrium amount of floating fuel amount and the current fuel injection amount. The calculation is based on a correction coefficient DK indicating the ratio of how much to compensate. Here, the balance amount Mφ and the correction coefficient DK are both correction factors that are functions of the engine temperature Tw, the intake air amount Qa, and the engine rotation speed N, and vary depending on the engine operating state, engine temperature, etc. It shows the quantitative changes in adhesion and floating fuel. (Problems to be Solved by the Invention) However, in the fuel injection control device for an internal combustion engine of the prior application, as shown in FIG. The value DKTW obtained from the table map (see Fig. 17) using the previous transient correction IDM calculated as a parameter, the engine rotation speed N, and the basic injection f indicating the engine load condition.
The correction coefficient DK is obtained by multiplying by DKN obtained from the table map (see FIG. 18) using f1Tp as a parameter. For this reason, flattening the air-fuel ratio during full-throttle acceleration and partial acceleration when the engine is at high temperature is incompatible, and similarly, flattening the air-fuel ratio when the engine is at low temperature and at full-throttle acceleration and partial acceleration is also incompatible. That is, in either state, the air-fuel ratio may vary with respect to the target air-fuel ratio. For example, as shown by the solid line in FIG. 10 (A), even though the fluctuation of the air-fuel ratio with respect to the target air-fuel ratio is relatively small when the engine is in a high-temperature state of full throttle acceleration, the solid line in FIG. 10 (B) As shown in , the air-fuel ratio fluctuates greatly in the partial acceleration state at high temperatures. Similarly, as shown by the solid line in Figure 11(C), although the fluctuation of the air-fuel ratio with respect to the target air-fuel ratio is relatively small in the partial acceleration state when the engine is at low temperature, As shown by the solid line, the air-fuel ratio fluctuates greatly in the full-throttle acceleration state at low temperatures. In particular, during partial acceleration at high temperatures, as shown by the solid line in Figure 10 (B), the fuel injection amount is under-corrected at the beginning of acceleration, causing the air-fuel ratio to deviate significantly toward the lean side, resulting in a large lean spike. Immediately after that, on the contrary, over-correction occurs and the air-fuel ratio deviates to the rich side.
Becomes rich spike state. In addition, FIG. 10 (A), (B) and FIG. 11 (C),
(D) S indicates the point in time when accelerator operation starts. In this way, even in the fuel injection control device for an internal combustion engine of the prior application, the air-fuel ratio during acceleration of the engine fluctuates with respect to the target air-fuel ratio, which causes a number of problems in terms of vehicle drivability, especially in lean-burn engines. In this case, it is expected that the generated torque will fluctuate, leading to unnatural driving. (Object of the Invention) Therefore, the present invention detects the warm-up state and load state of the engine, calculates a correction coefficient based on a correction value given with at least these warm-up state and load state as parameters, and calculates the transient correction amount. By making appropriate corrections, the air-fuel ratio can be flattened over the entire range from partial acceleration to full-throttle acceleration, regardless of the warm-up state of the engine, further improving engine drivability, especially for lean-burn engines. The objective is to provide an engine that does not cause any unnatural driving. (Means for Solving the Problems) In order to achieve the above object, the fuel injection control device for an internal combustion engine according to the present invention uses engine load and engine speed as parameters, as shown in FIG. The operating state detecting means a detects the operating state of the engine, and the warm-up state detecting means detects the warm-up state of the engine. An equilibrium amount calculation means C that calculates the equilibrium amount of floating fuel, and the difference between the adhesion calculated by the equilibrium amount calculation means C, the equilibrium amount of floating fuel, the adhesion to the intake system at that time, and the predictive variable of the amount of floating fuel. The difference value calculation means d calculates a value, the correction coefficient calculation means e calculates a correction coefficient based on a correction value given as a parameter at least the engine warm-up state and the load state, and the difference value calculation means d calculates the difference value. Transient correction amount calculation means f for correcting the difference value using the correction coefficient calculated by the correction coefficient calculation means e, and calculating a transient correction amount for correcting the final fuel supply amount and the next predicted variable; predictive variable calculation means g for calculating a new predictive variable based on the previous transient correction amount calculated in step f and the previous predictive variable for the amount of adhering and floating fuel; A supply amount calculation means calculates a basic supply amount and corrects the basic supply amount based on the transient correction amount to calculate a final fuel supply amount, and supplies fuel to the engine based on the output of the supply amount calculation means. fuel supply means i
It is equipped with. (Operation) In the present invention, the warm-up state and load state of the engine are detected, and a correction coefficient is calculated based on a correction value given using at least these warm-up state and load state as parameters, and the transient correction amount is appropriately corrected. be done. therefore,
Regardless of the warm-up state of the engine, the air-fuel ratio is flattened over the entire range from partial acceleration to full-throttle acceleration, further improving engine drivability and reducing unnatural driving, especially in lean-burn engines. It will be resolved. (Example) Hereinafter, the present invention will be explained based on the drawings. 2 to 11 are diagrams showing a first embodiment of the present invention. First, the configuration will be explained. In FIG. 2, 21 is an engine, and intake air is supplied to each cylinder of the engine 21 through an intake pipe 22. A fuel injection valve (fuel supply means) 23 that injects fuel to each cylinder is attached to the intake pipe 22, and the flow rate of intake air supplied to the engine 21 is controlled by a throttle provided at the gathering part of the intake pipe 22. valve 2
4. The throttle valve 24 is linked with the accelerator pedal of the vehicle, and the valve opening degree C of the throttle valve 24 is
V is detected by the throttle opening sensor 25. The intake air flow rate (hereinafter referred to as intake air amount) Qa is detected by the air flow rate sensor 26. Further, the rotation speed N of the engine 21 is detected by a crank angle sensor 27, and the crank angle sensor 27 includes a signal disc plate 27a attached to the crankshaft of the engine 21 and provided with a protrusion on the outer periphery,
It has a magnetic detent 27b for detecting the projection a. Also, the temperature TW of the cooling water flowing through the water jacket
is detected by the water temperature sensor 28. The throttle opening sensor 25, air flow rate sensor 26, and crank angle sensor 27 constitute operating state detection means, and the water temperature sensor 28 constitutes warm-up state detection means, and these signals are sent to the control unit 29. has been entered. The control unit 29 has functions as an equilibrium amount calculation means, a difference value calculation means, a correction coefficient calculation means, a transient correction amount calculation means, a predicted variable calculation means, and a supply amount calculation means, and includes a CPU 30, a ROM 31, a RAM 32, and an I1.
0 port 33. CPU30 is ROM
According to the program written in the I10 port 31, required external data is fetched from the I10 boat 33, and data is transferred to and from the RAM 32 for arithmetic processing, and the processed data is transferred to the I10 boat as necessary. Output to 33. The ROM 31 stores a program that controls the CPU 30, and the RAM 32 is made up of, for example, a non-volatile memory and stores data used in calculations in the form of a map, etc., and retains the stored contents even after the engine 21 is stopped. do. The I10 port 33 receives signals from the throttle opening cm 25, air flow sensor 26, crank angle sensor 27, water temperature sensor 28, as well as signals from an air-fuel ratio sensor (not shown), an ignition switch, etc. The input signal is converted to digital. Further, the I10 boat 33 outputs an injection signal Si to the fuel injection valve 23. Next, the effect will be explained. Generally, the air-fuel ratio of an internal combustion engine using a fuel injection valve is controlled by changing the duty value of an injection signal output to the fuel injection valve to adjust the fuel injection amount. In the case of this embodiment, the duty value of this injection signal Si is calculated by the control unit 29. Hereinafter, this effect will be explained based on FIGS. 3 to 10. FIG. 3 is a flowchart showing a fuel injection control program. This program is executed, for example, in synchronization with the rotation of the engine. First, at P, the basic injection amount (basic supply amount) according to the following formula ■
Calculate Tp. However, K: constant. Next, at P2, the equilibrium amount of adhesion and floating fuel in the intake system under steady conditions (steady IT) Mφ is calculated based on the engine speed N, basic injection amount Tp, and cooling water temperature TW. Note that the calculation of the balance amount Mφ will be explained in detail in the balance amount calculation program shown in FIG. 4, which will be described later. Next, a correction coefficient DK is calculated using P. Here, the correction coefficient DK is a coefficient that indicates how much to compensate for adhesion in the intake system and insufficient or excessive amount of floating fuel by correcting the current fuel injection amount, and this correction coefficient DK is constant. However, in order to perform more accurate correction, in this example, experiments are performed based on the engine rotation speed N, cooling water temperature TV, basic injection amount 'rp, accelerator change rate, and transient correction amount DM, which will be described later. Determine from the value. This calculation based on experimental values will be explained in detail in the correction coefficient calculation program shown in FIG. 5, which will be described later. In P4, according to the following equation
Calculate M. DM=DK (Mφ-M) ・・・・・・■However, Mφ
: Equilibrium amount M of adhesion and floating fuel amount obtained in P2 Predictor variable of adhesion and floating fuel amount obtained in the previous step P8 Here, the predictor variable M is P, as will be described later in the previous process. This is a predictive variable for the amount of adhesion and floating fuel obtained, and this predictive variable M has a meaning as a predicted value of the amount of adhesion and floating fuel in the intake system at that time. Therefore, Mφ−
M means a deficit or excess amount of adhering or floating fuel compared to the equilibrium state. Then P, ~P
In steps , the actual fuel injection amount (final injection amount) Ti is determined. That is, at P, fuel injection is performed at 1T according to the following formula (■)
pF is calculated, and then, in P6, the final injection amount Ti is calculated according to the following equation. TpF=Tp+DM ・・・・・・■ However, T p : The value obtained from P + 'ri='rp
FxαXC0EF+Ts ・・・・・・■However, T
pF: Value obtained from Ps α: Air-fuel ratio feed bank correction coefficient C0EF: Increase correction coefficient TS: Voltage correction Note that the above-mentioned air-fuel ratio feedback correction coefficient α is a correction coefficient that is increased or decreased based on the output of the oxygen sensor. The increase correction coefficient C0EF is a correction coefficient for providing an air-fuel ratio that produces the maximum output when the engine is fully opened, the increase correction at startup, and the increase correction at low water temperature.
is the voltage correction amount, and both are correction coefficients that have been used in the past. Furthermore, in P7, the final injection amount Ti is stored in the output register of the I10 boat 33 as a voltage pulse width having a predetermined duty value, and an injection signal Si having a fuel injection pulse width corresponding to this Ti is sent to the output register of the I10 boat 33. Output to the injection valve 23. As a result, a predetermined amount of fuel is injected from the fuel injection valve 23. Next, P calculates the current predictive variable M according to the following equation (2), and this routine ends. M = M' + DM ・・・・・・■ However, M': Previous value Therefore, here, we use the predictive variable M, which means the amount of adhesion and floating fuel, as the transient value corresponding to the amount of change in adhesion and floating fuel. The predictive variable M to be used in the next P4 is calculated by correcting with correction+i1DM. FIG. 4 is a flowchart showing a program for calculating the balance amount, and this process corresponds to step P2 described in FIG. 3 above. This program uses cooling water temperature stage T.
The balance amount Mφ is calculated according to wO to TW4. First, it is determined based on the pH whether the cooling water temperature TW is larger than the first predetermined value TW1 (Tw≧Twl or not), and Tw≧
When Twl, use PI□ to change engine speed N and basic injection f.
The equilibrium IMφO is looked up from the table map corresponding to the cooling water temperature Two using fTp as a parameter. Next, in PI3, the engine speed N and basic injection iTp
The equilibrium iMφ1 is looked up from the table map corresponding to the cooling water temperature Twl using as a parameter (see FIG. 6), and the equilibrium iMφ is calculated in accordance with the following linear approximation interpolation calculation formula (2) at P14, and this routine ends.・・・・・・■ On the other hand, if the pH is not Tw2TW1, use pus to determine whether the cooling water temperature Tw is within a predetermined range (TWI>Tw≧TW2), and if Twl>Tw≧Tw2, the above PI6 to PI in the same way as steps p+z to P14 of
When the cooling water temperature Tw is Twl≧TW≧Tw2 at l+, the equilibrium amount Mφ is calculated according to the following equation (2), and this routine ends.・・・・・・■ In addition, when Tw 1 >TW≧TW2 is not determined in Pl5, the cooling water temperature Tw is within the predetermined range (7w2>Tw≧
7w2>Tw≧Tw3
When , the cooling water temperature Tw is Tw 2 > Tw □ at P2゜ to P2□ in the same way as the steps p+z to PI4 described above.
The equilibrium mMφ at Tw3 is calculated according to the following equation (2), and this routine is ended. ......■ On the other hand, when 7w2>Tw≧TW3 at Pl, the cooling water temperature TW is smaller than the predetermined value TW3 (Tw < T
w3) and perform P2. in the same manner as steps P12 to PI4 above. ~Push the cooling water temperature TW
The equilibrium iMφ when < T w 3 is calculated according to the following equation (2), and this routine is ended.・・・・・・■ In this way, the different cooling water temperatures TwO to Tw4
The balance amount Mφ0-Mφ4 obtained as an experimental value using the rotational speed N and basic injection ff1Tp as parameters is looked up, and the balance IMφ of the adhesion of the intake system and the floating fuel under steady conditions is calculated by interpolation calculation of linear approximation. You can ask for it. FIG. 5 is a flowchart showing a program for calculating correction coefficients, and corresponds to step P described in FIG. First, in P41, look up the correction value DKTwTp from the table map shown in FIG. 7, which uses the cooling water temperature (signal indicating the warm-up state of the engine) Tw and the basic injection amount (signal indicating the engine load state) Tp as parameters. Up, P
In step 4□, a correction value DKDM is looked up from a table map having the characteristics shown in FIG. 8 based on the transient correction amount DM calculated in the previous routine. Next, in P43, a rotation speed correction coefficient DKN is look-amplified based on the engine rotation speed N from the table map shown in FIG.
A correction value DKAC is calculated based on the rate of change of the accelerator. Furthermore, in P4S, according to the following formula [phase], the correction coefficient D
K is calculated and the process ends. DK= (DKTwTp +DKDM)xDKNXD)
<AC...[Phase] Here, as shown in FIG. 7, if the cooling water temperature Tw is large and the basic injection amount 'rp is not relatively large, the correction value DKTwTp is set large, The air-fuel ratio is flattened during partial acceleration at high temperatures. Also,
In the earlier application (Japanese Patent Application No. 60-243605), the cooling water temperature TW and the previous transient correction iDM are used as parameters in the planar table map shown in FIG.
Flatness of the air-fuel ratio can be ensured at intermediate or high temperatures without necessarily performing correction using the transient correction IDM. However, at low temperatures, the flatness of the air-fuel ratio worsens (the air-fuel ratio becomes lean at the beginning of acceleration), so in this embodiment, as shown in FIG. The correction value DKTwTp is obtained from the table map shown in FIG. 8, the correction value DKDM is obtained from the previous transient correction value DM based on the table map shown in FIG. There is. This ensures the same flatness of the air-fuel ratio at low temperatures as in the previous application, and compared to the conventional example, it is possible to make the steady-state air-fuel ratio leaner at low or intermediate temperatures, reducing engine fuel consumption. Also, it is possible to prevent the plug from smoldering. Further, the correction value DKAC compensates for insufficient correction at the initial stage of acceleration. Note that in this embodiment, the rotation speed N, basic injection ftTp, and cooling water temperature Tw are used to obtain the equilibrium amount Mφ and the correction coefficient DK, but the present invention is not limited to this. For example, instead of the basic injection ff1Tp, Therefore, the intake air amount Qa
, the intake pipe internal pressure, the throttle valve opening Cv, etc., or the intake pipe internal pressure temperature, etc. may be used instead of the cooling water temperature Tw. In this way, in this embodiment, the transient correction amount DM can be obtained with high accuracy under all acceleration/deceleration conditions including transient times, as in the case of the earlier application (Japanese Patent Application No. 60-243605) mentioned above. However, in this embodiment, the correction coefficient D is calculated based on the correction value DKTwTp which is given using at least the engine cooling water temperature Tw and the basic injection t2tTp, that is, at least the warm-up state and load state of the engine.
Since K is calculated and the transient correction amount DM is appropriately corrected, the air-fuel ratio can be flattened over the entire range from partial acceleration to full-throttle acceleration, regardless of the warm-up state of the engine. That is, as shown by the broken lines in FIGS. 10(A) and 10(B), the waveforms of the air-fuel ratio during full-throttle acceleration and partial acceleration when the engine is at high temperature can be flattened, and similarly, the waveforms of the air-fuel ratio in FIG. 11(C) can be flattened. ) and (D), the waveforms of the air-fuel ratio during full-throttle acceleration and partial acceleration when the engine is at low temperature can be flattened. In particular, as shown in FIG. 10(B), during partial acceleration at high temperatures of the engine, the air-fuel ratio waveform of this example is flattened compared to the air-fuel ratio waveform of the prior application shown by the solid line in the figure. , it is possible to eliminate the phenomenon that the lean spike becomes large at the beginning and then becomes the rich spike immediately after, which was pointed out in the problem section above. As a result, the drivability of the engine can be further improved, and in particular, in a lean burn engine, unnatural driving can be eliminated. In addition, the dashed-dotted line in FIG. 10.11 shows the waveform of the air-fuel ratio without acceleration correction. FIG. 12.13 is a diagram showing a second embodiment of the present invention,
This is an example in which the control of the transient correction amount DM described above is similarly applied to correction during fuel cut and recovery. In explaining this embodiment, steps that perform the same processing as in the first embodiment will be given the same numbers and their explanations will be omitted, and steps that are different will be given step numbers circled and their contents will be explained. . In the program shown in Fig. 12, after completing the processing of Pl, it is determined whether fuel is being cut using PSI, and if fuel is being cut, the equilibrium f1Mφ is set to a predetermined value MFCO value using psz, and the process proceeds to P, and the fuel is being cut. If it is not inside, proceed directly to P2. Here, when the predetermined value MFC is set to (0) or a value much smaller than the normal equilibrium IMφ, the air-fuel ratio normally shifts toward the lean direction during fuel cut and recovery. This is because floating fuel adhering to the intake system is sucked into the engine 21 during fuel cut, and at the time of recovery, the amount of fuel injected to match the intake air amount Qa is insufficient to compensate for the fuel adhering to the intake system again.However, In this embodiment, as shown in FIG.
During fuel cut, the equilibrium IMφ is set to zero, for example, so the variable M gradually decreases and gradually approaches the equilibrium amount Mφ. Therefore, when the equilibrium iMφ reaches a predetermined value during recovery, Mφ−M>O, and an appropriate increase correction is made. Note that when the fuel cut time is short, that is, when fuel cut and recovery are started when Mφ-M has not yet reached a large value, Mφ-M at the time of recovery does not become a very large value, and the transient correction iD
Although M also becomes a small value, in this case, the adhesion to the intake system and the amount of floating fuel have not decreased so much, so an optimal correction can be made taking this into account. Further, the increase correction at the time of starting the engine can be performed in the same way. In this case, by setting the variable M to zero in a separately provided initialization routine when the ignition switch is turned on, it is possible to appropriately perform the increase correction according to the operating state at the time of starting cranking. Furthermore, appropriate correction can be made in the same way even after the complete explosion. However, in this case, during a cold start, some of the fuel adheres to the cylinder wall and is discharged without being burned, so it is preferable to increase the amount by that amount. In this way, in this embodiment, what used to be various corrections can be done with a minimum amount of correction.
Furthermore, fuel injection can be controlled with high precision. In other words, starting increase correction, simplification of start increase correction (only correction for unburned emissions), abolishing increase correction after idling,
In addition, it becomes unnecessary to separately perform correction after fuel cut, and there is no need to perform correction separately for acceleration and deceleration. Furthermore, since the correction coefficient DK is calculated in the same manner as in the first embodiment, the same effects as in the first embodiment can be obtained. Figures 14 and 15 are diagrams showing a third embodiment of the present invention,
This is an example in which learning control is performed not only during steady operation but also during transient correction. FIG. 14 is a flowchart showing the learning control feedback routine, and shows P61 to P? 4 indicates each step. First, Pal determines whether the feedback condition is satisfied based on the operating conditions, and if it is satisfied, P
At 62, the output 02 of the oxygen sensor is compared with the comparison reference value S/L. When 0□<S/L, it is determined that the air-fuel ratio is leaner than the stoichiometric air-fuel ratio, and an increase correction amount is calculated by PI (proportional, integral) control at P and 3. Also, when 0□><S/L, it is determined that the air-fuel ratio is richer than the stoichiometric air-fuel ratio,
At P64, a weight loss correction amount is calculated by PI control. Next, in P6S, the air-fuel ratio feedback correction coefficient α is corrected according to the following equation 0. α=α'+p+l ・・・・・・■ However, α': Previous air-fuel ratio feedback correction coefficient P+1: Increase/decrease correction amount pbb, the absolute value IDMI of the transient correction amount DM is compared with the comparison reference value LGDM, l DM When l > LGDM, it is determined that a transition is occurring, and the cumulative number n is compared with the learning determination number LGn in P6□. When n>LGn, P61
1, calculate the average value α according to the following equation [phase], and proceed to Pb0. Σα α=□ ......O In Pb9, the addresses of the RAM 32 corresponding to the transient learning coefficients GMφ1 to CAMφn are rewritten using the average feedback correction coefficient α. The address of RAM M32 has transient learning coefficients CMφ1 to GMφ depending on the cooling water temperature Tw.
n is assigned to each address, and the content of the address is rewritten according to the cooling water temperature Tw. That is, RAM3 corresponding to the average feedback correction coefficient α and the cooling water temperature Tw
2 and the difference is added to the value in RAM. When the rewriting of RAM32 is completed, the integrated value Σ is set at P7゜.
α and the cumulative number n

Substitute [0] and proceed to Pal. Next, at P7+, a steady learning calculation is performed and the current processing is ended. On the other hand, when n < L G N in P6'l, it is determined that the number of samples is small and the accuracy is poor, and P. The integrated value Σα
and the product γ number n.

Substitute [0] and proceed to PH1. Also, in P66, if l DM l <LGDM, it is determined that it is not a transient state (it is in a steady state), and P? At Z, calculate the integrated value of α (Σα=Σα+α) and the integrated value of α (n=n+1), and proceed directly to P7□, P7. I will omit the details below, but after determining that it is in a steady state,
Similarly to the transient case, the value in the RAM 32 is rewritten using the average feedback correction coefficient α. In the steady state, the transient learning coefficient GMφ1 to GMφn is determined according to the cooling water temperature TW.
It is preferable to allocate them according to the engine speed N and the basic injection amount Tp, rather than allocating them according to the engine speed N and the basic injection amount Tp. On the other hand, when the feedback condition is not satisfied at Pb0, the steady learning result is referred to from the address of the RAM 32 stored according to the operating condition at P'J3 to calculate the feedback correction coefficient α, and at P'+4, α The current process is completed by substituting (0) for the integrated value Σα of The only difference from the calculation program shown in FIG.
At at, the transient correction amount DM is calculated according to the following equation. DM=DKX (MφXGMφ−M) ・・・・・・＠
Note that the transient learning coefficient GMφ is referred to by retrieving the value learned for the cooling water temperature TW in the feedback routine from the address of the RAM 32 corresponding to the current cooling water temperature Tw. This type of transient learning control is effective because the adhesion of the intake system and the amount of floating fuel may change depending on the nature of the fuel.
Furthermore, since this changes economically depending on the amount of deposits attached to the intake system, the purpose is to correct this change. Here, if inferior fuel is used, the air-fuel ratio shifts toward lean during acceleration. Therefore, in this embodiment, the average feedback correction coefficient α, which becomes a large value during a transition during feedback control, is used to rewrite the transient learning coefficient GMφ to a larger value. Therefore, the transient correction iDM also increases, so that the lean air-fuel ratio during acceleration is corrected. Furthermore, the accuracy of the transient correction IDM can be improved little by little each time learning is repeated. In this way, in this embodiment, the learning control uses the transient learning coefficient GMφ to determine the optimal transient correction amount even when using inferior fuel or when deposits are attached to the intake system. DM can be given. Therefore, the accuracy of air-fuel ratio control can be improved. Furthermore, in this embodiment as well, since the correction coefficient DK is calculated in the same manner as in the first embodiment, the same effects as in the first embodiment can be obtained. (Effects) According to the present invention, the warm-up state and load state of the engine are detected, a correction coefficient is calculated based on a correction value given at least with these warm-up state and load state as parameters, and the transient correction amount is appropriately adjusted. Since it is corrected, the air-fuel ratio can be adjusted to a flat rate over the entire range from partial acceleration to full-throttle acceleration, regardless of the warm-up state of the engine.
Engine drivability can be further improved. Especially in lean burn engines, unnatural driving can be eliminated.

[Brief explanation of the drawing]

FIG. 1 is a basic conceptual diagram of the present invention, FIGS. 2 to 11 are diagrams showing a first embodiment of the present invention, and FIG. 2 is an overall configuration diagram thereof,
FIG. 3 is a flowchart showing the fuel injection control program, FIG. 4 is a flowchart showing the program for calculating the equilibrium ■Mφ, FIG. 5 is a flowchart showing the program for calculating the correction coefficient DK, and FIG. A table map showing an example of the balance amount, FIG. 7 is a table map of the correction value DKTwTp, FIG. 8 is a table map of the correction value DKDM, FIG. 9 is a table map of the rotation speed correction value DKN, and FIG. Figures (A) and (B) are graphs showing the waveforms of the air-fuel ratio in the full-throttle acceleration and partial acceleration states at high temperatures, and Figures 11 (C) and (D) are graphs showing the waveforms of the air-fuel ratio in the full-throttle acceleration and partial acceleration states at low temperatures. Graphs showing the waveform of the air-fuel ratio, Figures 12 and 13 are diagrams showing the second embodiment of the present invention, Figure 12 is a flowchart showing the fuel injection control program at the time of fuel cut recovery, and Figure 13 is a flowchart showing the fuel injection control program at the time of fuel cut recovery. 14 and 15 are graphs showing the waveforms of each signal during the fuel cut recovery, and FIG. 14 is a flowchart showing the feed bank routine of the learning control, and FIG. Figure 16 is a flowchart showing a program for fuel injection control using learning control, Figures 16 to 18 are diagrams showing a fuel injection control device for an internal combustion engine according to the prior application, and Figure 16 is a flowchart showing a program for calculating the correction coefficient DK. FIG. 17 is a table map of the correction value DKTW, and FIG. 18 is a table map of the rotation speed correction value DKN. 21...engine, 23...fuel injection valve (fuel supply means), 28...
...Water temperature sensor (warm-up state detection means), 29...
...Control unit (flat f%i W performance W-
means, difference value calculation means, correction coefficient calculation means, transient correction amount calculation means, predictive variable calculation means, supply amount calculation means).

Claims (1)

[Scope of Claims] a) Operating state detection means for detecting the operating state of the engine using engine load and rotation speed as parameters; b) Warm-up state detection means for detecting the warm-up state of the engine; c) Engine d) an equilibrium amount calculation means for calculating an equilibrium amount of adhering and floating fuel to the intake system in a steady state based on the operating state and warm-up condition of the; and d) an equilibrium amount of adhering and floating fuel calculated by the equilibrium amount calculating means. and e) a difference value calculation means for calculating a difference value between the amount of fuel adhering to the intake system at that time and a predictive variable of the amount of floating fuel; f) correcting the difference value calculated by the difference value calculating means using the correction coefficient calculated by the correction coefficient calculating means, and correcting the final fuel supply amount and the next predicted variable; a transient correction amount calculating means for calculating a transient correction amount of g;
) predictive variable calculating means for calculating a new predictive variable based on the previous transient correction amount calculated by the transient correction amount calculating means and the previous predictive variable of the adhering and floating fuel amount; h) engine operation; a supply amount calculation means for calculating a basic supply amount of fuel based on the state and correcting this basic supply amount based on the transient correction amount to calculate a final fuel supply amount; i) based on the output of the supply amount calculation means; 1. A fuel injection control device for an internal combustion engine, comprising: a fuel supply means for supplying fuel to the engine.