JP2514446B2 - Fuel supply control device for internal combustion engine with knocking control function - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply control device for an internal combustion engine with a knocking control function, and more specifically, an internal combustion engine in which a basic ignition timing is corrected and controlled based on whether or not knocking occurrence is detected. The present invention relates to correction control of a fuel supply amount according to the ignition timing correction in an engine.

<Prior Art> When knocking at a predetermined level or higher occurs in an internal combustion engine, not only the output is reduced, but also shock is absorbed.
Since the exhaust valve and the piston are adversely affected, the ignition timing is corrected by detecting the occurrence of knocking so that the ignition timing can be advanced more while avoiding the knocking occurrence. (JP-A-58-105036
No.

Further, while using gasoline with a high octane number (hereinafter, referred to as high-octane gasoline) as a standard fuel, even when gasoline with an octane number lower than such standard fuel (hereinafter referred to as regular gasoline) is supplied, the optimum ignition timing can be controlled. As described above, by using the difference in the allowable ignition advance value due to the difference in the octane number, the fuel used is discriminated from the result (anti-knock property) of the ignition timing correction depending on the occurrence of knocking as described above, and based on the discrimination result In some cases, the maps of the basic ignition timings set in advance for high-octane gasoline and regular gasoline are switched and used.

<Problems to be Solved by the Invention> However, in the switching control of the basic ignition timing map based on the knocking control result as described above, when the knocking occurrence level changes due to changes in environmental conditions and operating conditions (steady ← → transient), There is a possibility that the used fuel is erroneously determined and the ignition controllability is deteriorated. For this reason, for example, as shown in FIG. 7, the ignition timing control range is between the ignition timing at which the maximum torque is obtained with high-octane gasoline (ignition advance value) and the ignition timing at which knocking can be barely avoided with regular gasoline. The ignition timing correction range is set as narrow as possible to prevent controllability fluctuations by controlling ignition with the maximum advance value that can avoid knocking within this range and without changing the map depending on the fuel used. I took it into consideration.

However, when regular gasoline is used, the ignition timing is retarded compared to when high-octane gasoline is used to avoid knocking, and electronic control of the fuel supply amount is naturally controlled so that the air-heat ratio matches high-octane gasoline. Therefore, there is a possibility that the exhaust temperature shown in FIG. 8 exceeds the allowable value (for example, 850 ° C.) due to the large retard correction and the air-fuel ratio control that does not match this, so that it is inserted in the exhaust system. There is a risk of accelerating the deterioration of the catalyst or causing the catalyst to melt.

The present invention has been made in view of the above problems, and makes it possible to prevent the exhaust temperature from becoming a predetermined high temperature or more even in a state where the ignition timing is largely retarded to avoid knocking. The purpose is to

<Means for Solving the Problems> Therefore, in the present invention, as shown in FIG. 1, a basic operating condition detecting means for detecting an operating condition of the internal combustion engine and a basic operating condition detecting means for detecting the operating condition of the internal combustion engine are provided. Basic ignition timing setting means for setting the ignition timing, knocking detection means for detecting the occurrence of knocking of the internal combustion engine, and ignition for increasing / decreasing the correction value of the basic ignition timing according to the presence / absence of detection of knocking occurrence by the knocking detection means. Timing correction value setting means, ignition timing setting means for correcting the basic ignition timing based on the correction value of the basic ignition timing set thereby, and setting the final ignition timing, and the final ignition timing set by the ignition timing setting means. In an internal combustion engine with a knocking control function configured to include an ignition signal output unit that outputs an ignition signal to an ignition device based on ignition timing, Fuel increase correction means for increasing and correcting the fuel supply amount to the engine according to the retard correction amount by the correction value of the basic ignition timing set by the correction value setting means, and the fuel increase amount when the engine temperature is below a predetermined value. The fuel supply control device is configured to include an increase correction inhibiting unit that inhibits the increase correction of the fuel supply amount by the correcting unit.

Here, as shown by the dotted line in FIG. 1, the air-fuel ratio detection means for detecting the air-fuel ratio of the engine intake air-fuel mixture, and the actual air-fuel ratio is the target air-fuel ratio based on the air-fuel ratio detected by this air-fuel ratio detection means. Based on the air-fuel ratio learning correction value which is learned and set by the air-fuel ratio learning correction value setting means for learning and setting the air-fuel ratio learning correction value for correcting the fuel supply amount The air-fuel ratio learning correction means for correcting the amount of fuel supplied to the engine, the learning setting of the air-fuel ratio learning correction value by the air-fuel ratio learning correction value setting means is set at the time of increasing correction by the fuel increase correction means. It is preferable to provide a prohibiting air-fuel ratio learning prohibition means.

<Operation> According to this configuration, the basic ignition timing setting means sets the basic ignition timing based on the operating condition of the internal combustion engine detected by the operating condition detecting means. On the other hand, the ignition timing correction value setting means increases or decreases the correction value of the basic ignition timing according to the presence or absence of knocking detected by the knocking detection means. Then, the ignition timing setting means corrects the basic ignition timing based on the engine operating condition based on the correction value based on the presence or absence of knocking to set the final ignition timing at which the occurrence of knocking can be avoided.

In this way, when the final ignition timing is set according to the presence or absence of knocking, the ignition signal output means outputs an ignition signal to the ignition device based on the final ignition timing, and the ignition timing Ignite.

Such a configuration is the conventional ignition timing control accompanied by knocking avoidance control, but here, the fuel increase correction means is involved in the ignition timing control, and the basic fuel injection timing of the basic ignition timing set by the ignition timing correction value setting means is set. The fuel supply amount to the engine is increased and corrected according to the retard correction amount based on the correction value. That is, if the retardation is greatly corrected, the exhaust temperature rises. Therefore, the amount of fuel is increased by that amount to suppress the rise in the exhaust temperature.

Further, the increase correction prohibiting means prohibits the increase of the fuel supply amount by the fuel increase correcting means when the engine temperature is lower than a predetermined value, and is unnecessary when the engine temperature does not reach the abnormally high exhaust gas temperature below the predetermined temperature. Not be done.

Further, the air-fuel ratio learning correction value setting means sets the air-fuel ratio learning correction value for correcting the fuel supply amount so that the actual air-fuel ratio becomes the target air-fuel ratio based on the air-fuel ratio detected by the air-fuel ratio detecting means. When the learning setting is performed and the air-fuel ratio learning correction means has a so-called air-fuel ratio learning correction function configured to correct the fuel supply amount to the engine based on the air-fuel ratio learning correction value, the air-fuel ratio learning prohibition means Means that learning setting of the air-fuel ratio learning correction value by the air-fuel ratio learning correction value setting means is prohibited during the increase correction by the fuel increase correction means, and the accuracy of the air-fuel ratio learning is deteriorated by the fuel increase for suppressing the exhaust temperature rise. Prevent.

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

In FIG. 2 showing an embodiment, air is taken into the internal combustion engine 1 through an air cleaner 2, an intake duct 3, a throttle chamber 4 and an intake manifold 5.

An air flow meter 6 is provided in the intake duct 3 and detects an intake air flow rate Q. The throttle chamber 4 is provided with a throttle valve 7 interlocking with an accelerator pedal (not shown) to control the intake air flow rate Q.
The throttle valve 7 is provided with a throttle sensor 15 for detecting the opening TVO. Intake manifold 5
Is provided with an electromagnetic fuel injection valve 8 for each cylinder, and injects and supplies to the engine 1 fuel that is pressure-fed from a fuel pump (not shown) and is controlled to a predetermined pressure by a pressure regulator.

The control of the fuel injection amount by the fuel injection valve 8 is adapted to the use of high-octane gasoline which is a standard fuel, and the intake air flow rate Q detected by the air flow meter 6 in the control unit 9 with a built-in microcomputer. , The basic fuel injection amount Tp = K × Q / N (K is a constant) is calculated from the engine speed N calculated based on the signal from the crank angle sensor 10 built in the distributor 13, and the basic fuel The final fuel injection amount Ti is set by making various corrections to the injection amount Tp, and a drive pulse signal having a pulse width corresponding to this fuel injection amount Ti is sent to the fuel injection valve 8 in synchronization with the engine rotation. By outputting, the fuel injection valve 8 is opened for a predetermined time, and a predetermined amount of fuel is injected and supplied to the engine 1.

Here, as the correction value for correcting the basic fuel injection amount Tp, various correction coefficients COEF including the startup increase correction based on the cooling water temperature Tw representing the engine temperature, the actual air-fuel ratio to the target air-fuel ratio (for example, The air-fuel ratio feedback correction coefficient α for feedback correction to the theoretical air-fuel ratio), and the air-fuel ratio learning correction coefficient (air-fuel ratio learning correction value set by learning the deviation of this air-fuel ratio feedback correction coefficient α from the reference value for each operating condition. ) KBLRC and a correction amount for correcting the change in the effective injection time of the fuel injection valve 8 due to the battery voltage.
There is Ts etc.

The air-fuel ratio feedback correction coefficient α is based on the oxygen concentration in the exhaust gas detected by the oxygen sensor 16 serving as the air-fuel ratio detection means interposed in the exhaust system, and is rich with respect to the target air-fuel ratio of the actual engine intake air-fuel mixture. Distinguish lean,
The setting is controlled by, for example, proportional-plus-integral control so that the actual air-fuel ratio approaches the target air-fuel ratio. Further, the air-fuel ratio learning correction coefficient KBLRC learns the deviation of the air-fuel ratio feedback correction coefficient α from the reference value (1.0) for each operating region divided into a plurality of areas, for example, the basic fuel injection amount Tp and the engine speed N. The air-fuel ratio learning correction coefficient KB
By using LRC, the base air-fuel ratio obtained without correction by the correction coefficient α is made approximately the target air-fuel ratio in response to the required value change of the air-fuel ratio feedback correction coefficient α due to the difference in operating conditions.

As described above, in this embodiment, the control unit 9 has a function as an air-fuel ratio learning correction value setting means and an air-fuel ratio learning correction means.

In the downstream side of the oxygen sensor 16, CO, HC, NOx in the exhaust gas
A three-way catalyst 17 for oxidizing / reducing and purifying is provided, and a muffler 18 is provided on the downstream side of the three-way catalyst 17.

Further, each cylinder of the engine 1 is provided with a spark plug 11, to which high voltage generated in an ignition coil 12 is sequentially applied via a distributor 13, whereby spark ignition is performed to ignite an air-fuel mixture. To burn. Here, the ignition coil 12 has its high voltage generation timing controlled via a power transistor 12a attached thereto. Therefore, the ignition timing (ignition advance value) ADV is controlled by turning on the power transistor 12a.
The off-timing is controlled by controlling the ignition signal from the control unit 9. In the present embodiment, the ignition device is composed of the above-mentioned spark plug 11, ignition coil 12, power transistor 12a and distributor 13. The ignition device may be one in which each cylinder is provided with an ignition coil 12 and a power transistor 12a, and the distributor 13 does not perform power distribution.

In the control unit 9 having the functions of the basic ignition timing setting means, the ignition timing correction value setting means, the ignition timing setting means, and the ignition signal output means, the optimum ignition timing (ignition advance) is calculated based on various input signals. Angle value) AD
V is determined and an ignition signal is output to the ignition coil 12 so that ignition is performed at the ignition timing ADV.
Send to

Specifically, from the map of basic ignition timing ADV _B suitable for high-octane gasoline which is set in advance according to the operating conditions of the engine speed N and the basic fuel injection amount Tp representing the engine load, the basic of the corresponding operating conditions While the ignition timing ADV _B is searched and obtained, a correction value for the basic ignition timing ADV _B is obtained based on a signal from a knocking sensor 14 which is attached to a cylinder block of the engine 1 and detects a vibration caused by knocking. ADV _HOS is increased / decreased, and the basic ignition timing ADV _B is corrected with this correction value ADV _HOS to set the final ignition timing ADV. Since the basic ignition timing ADV _B is set on the basis of the engine speed N and the basic fuel injection amount Tp as described above, the operating condition detecting means in this embodiment includes the crank angle sensor 10 and the air flow meter 6. Equivalent to.

Then, energization of the primary side of the ignition coil 12 is started so that sufficient ignition energy is obtained by the ignition timing ADV, and the ignition timing is determined based on the detection signal of the crank angle sensor 10.
When ADV is detected, the energization is cut off to generate a high voltage on the secondary side, and the spark plug 11 is supplied with the high voltage for spark ignition.

The correction value ADV _HOS is a correction term added to the basic ignition timing ADV _B with an initial value of zero, and the knocking sensor 14
If the knocking occurrence is not detected by, the setting is increased by a predetermined value (advanced angle correction), and conversely, if the knocking occurrence is detected, the setting is decreased by a predetermined value (retarded angle correction), and as far as knocking does not occur Ignition is performed at an angular value.

Here, since the basic ignition timing ADV _B on the map is adapted to high-octane gasoline as described above, when using regular gasoline that is more prone to knocking, the ignition timing ADV adapted to high-octane gasoline is Since knocking occurs, the correction value ADV _HOS is set to decrease in response to the detection result of the knocking occurrence, and the correction value
ADV _HOS becomes a negative value and the basic ignition timing ADV _B is retarded. Therefore, when the delay correction amounts by the correction value ADV _HOS are large, it can be estimated that regular gasoline with a lower octane number is used as fuel instead of standard high-octane gasoline, in other words,
Decrease in octane number (decrease in antiknock property) can be indirectly detected in accordance with the increase in the retard correction amount.

Here, the ignition timing control and the fuel supply control by the control unit 9 will be described according to the programs respectively shown in the flowcharts of FIGS.

The program shown in the flow chart of FIG. 3 is a control program for the ignition timing ADV. First, in step 1 (denoted as S1 in the figure. The same applies hereinafter), the basic ignition timing ADV _B corresponding to high-octane gasoline is set to the basic ignition timing ADV _B in advance. Fuel injection amount
The basic ignition timing ADV _B matching the current operating conditions is searched for and obtained from the map stored for each operating region divided by Tp and the engine speed N.

In the next step 2, it is determined whether knocking occurs based on the signal from the knocking sensor 14,
When knocking has not occurred, the lead angle can be advanced more, so the routine proceeds to step 3, where a predetermined value is added to the correction value ADV _HOS so that the lead angle is corrected more. On the other hand, when the occurrence of knocking is detected, it is necessary to retard the knocking so as to eliminate such knocking promptly. Therefore, the _routine proceeds to step 4, where a predetermined value is subtracted from the correction value ADV _HOS and the current ignition timing ADV is exceeded. Make sure that the delay angle is corrected.

In this way, if the correction value ADV _HOS is increased or decreased depending on whether knocking occurs or not, in the next step 5, the correction value ADV _HOS is added to the basic ignition timing ADV _B obtained by searching from the map in step 1 to correct And the final ignition timing AD
Set V. Here, if the correction value ADV _HOS is positive, the basic ignition timing ADV _B is advanced, and if it is negative, the basic ignition timing ADV _B is retarded.

In step 6, the ignition timing AD set in step 5
It is determined whether V is smaller than a preset minimum advance value ADV _MIN , and the ignition timing ADV is smaller than the minimum advance value ADV _MIN due to excessive retard correction by the correction value ADV _HOS . At step S7, the minimum advance value ADV _MIN is set as the final ignition timing ADV so that ignition is not performed with an advance value smaller than the minimum advance value ADV _MIN .

The ignition timing ADV finally set in this way is set in step 8 for use in actual ignition control, and the energization of the ignition coil 12 is controlled based on this ignition timing ADV.

The program shown in the flowchart of FIG. 4 is a program for correcting the fuel supply amount according to the correction value ADV _HOS . First, at step 11, whether the correction value ADV _HOS is a negative value or not. To determine. The correction value ADV _HOS being a negative value means that the ignition timing ADV is retarded at the basic ignition timing ADV _B corresponding to high-octane gasoline, so the ignition timing ADV is retarded. It can be estimated that regular gasoline is used when the amount is more than a predetermined amount.

If it is determined in step 11 that the correction value ADV _HOS is negative, in the next step 12, it is determined whether the engine rotation speed N is equal to or higher than a predetermined speed Ns, and the exhaust temperature may exceed the allowable level. Determine if there is. When the engine rotation speed N is equal to or higher than the predetermined speed Ns and the rotation speed condition is such that the exhaust gas temperature rises, it is determined in the next step 13 whether the cooling water temperature Tw representing the engine temperature is equal to or higher than the predetermined temperature Tws.

Under the condition that the cooling water temperature Tw is equal to or higher than the predetermined temperature Tws and the engine speed N is high, if there is a possibility that the exhaust temperature may exceed the allowable level, the routine proceeds to step 14, and the correction value AD
A correction coefficient KRET for the fuel injection amount is searched for from a preset map based on V _HOS .

The correction coefficient KRET is for increasing the fuel injection amount as it increases, and is a negative correction value.
The larger the absolute value of ADV _HOS, the larger the correction coefficient KRET is set, and the larger the ignition timing ADV is greatly retarded, the larger the ratio (However, when the retard correction amount is small, the correction coefficient KRET is zero. The fuel amount increase correction is performed.

That is, when the retard angle is largely corrected by the correction value ADV _HOS, it is presumed that regular gasoline having an octane number lower than that of the high-octane gasoline to which the basic ignition timing ADV _B is adapted is used. Exhaust temperature rises due to retard correction for avoidance (see Fig. 8), but fuel supply control adapted to high-octane gasoline is applied as is, so fuel control can follow the rise in exhaust temperature due to retard. Instead, the exhaust temperature rises abnormally.

In order to suppress such an increase in exhaust temperature, in this embodiment,
When the retard correction amount by the correction value ADV _HOS is large, especially when the exhaust gas temperature is expected to rise, the fuel supply amount is increased and corrected to correct the air-fuel ratio to the rich side to raise the exhaust temperature. To prevent deterioration and melting loss of the three-way catalyst 17 due to an abnormal exhaust gas temperature.

On the other hand, at the time of non-retardation correction in which it is determined that the correction value ADV _HOS is not less than zero in step 11, or even in the state of being retarded by the correction value ADV _HOS , the engine speed N or the cooling water temperature Tw When the exhaust gas temperature is below the predetermined level and is not under the condition that the exhaust temperature exceeds the allowable level and rises, the routine proceeds to step 15, where the correction coefficient KRET is set to zero, and the correction by the correction coefficient KRET is canceled. The above control contents correspond to the fuel increase correction means and the increase correction prohibition means in this embodiment.

Next, the setting control of the fuel injection amount Ti will be described according to the program shown in the flowchart of FIG. This program is executed every predetermined minute time. First, in step 21, the basic fuel injection amount Tp that is suitable when using high-octane gasoline is used.
Is calculated using the intake air flow rate Q, the engine rotation speed N, and a constant K that matches the fuel property of high-octane gasoline and the injection characteristic of the fuel injection valve 8 (Tp ← K × Q / N).

In the next step 22, various correction coefficients COEF are set including the correction coefficient KRET set in the flowchart of FIG. The various correction coefficients COEF include the basic increase coefficient KTw based on the cooling water temperature Tw, the air-fuel ratio correction coefficient KMR for correcting the air-fuel ratio for each operating condition, and the correction coefficient KRET.
It is set by adding 1 to the result of adding, and when it becomes larger than 1, the basic fuel injection amount Tp is increased and corrected.

In the next step 23, the setting control is performed based on the detection result of the oxygen sensor 16 as described above, and the air-fuel ratio feedback correction coefficient α for feedback-correcting the actual air-fuel ratio to the target air-fuel ratio is set by another program (not shown). Read as the result set in.

In the next step 24, the air-fuel ratio learning correction coefficient KBLRC obtained by learning the deviation of the air-fuel ratio feedback correction coefficient α with respect to the reference value for each operating condition by another program (not shown) is read.

In step 25, the correction amount Ts for correcting the change in the effective injection time of the fuel injection valve 8 due to the battery voltage is set.

Then, in step 26, the final fuel injection amount Ti is
Calculate according to the following formula.

Ti ← Tp × COEF × α × KBLRC + Ts Here, the calculated fuel injection amount Ti is
The drive pulse signal having the pulse width corresponding to the fuel injection amount Ti is output to the fuel injection valve 8 at a predetermined timing.

By the way, as mentioned above, ignition timing ADV is retarded due to knocking caused by using regular gasoline with a lower octane number than high-octane gasoline, which is the standard fuel, and fuel injection is performed to suppress the rise in exhaust temperature accompanying this. When the air-fuel ratio learning is executed while the amount Ti is being increased and corrected by the correction coefficient KRET, learning that cannot be applied when using high-octane gasoline, which is the standard fuel, is performed, so as shown in the flowchart of FIG. It is preferable to prohibit the air-fuel ratio learning.

That is, in the program shown in the flowchart of FIG. 6, first, in step 31, it is determined whether or not the operating conditions for performing the air-fuel ratio learning are complete, and when the learning conditions are satisfied, the correction coefficient KRET is zero in the next step 32. Or not.

When the correction coefficient KRET is not zero, the amount of fuel has been increased and corrected to prevent the exhaust gas temperature from rising due to the use of regular gasoline.In such a state, the air-fuel ratio learning is not performed and the learning condition is ended. The learning correction coefficient KBLRC is learned and updated in step 33 only when the correction coefficient KRET is zero even when the condition is satisfied (when high-octane gasoline is used). Such control corresponds to the air-fuel ratio learning prohibition means in this embodiment.

<Effects of the Invention> As described above, according to the present invention, for example, when regular gasoline is used in an engine that uses high-octane gasoline as the standard fuel, the ignition timing is corrected to avoid knocking, and the standard fuel is still used. When the air-fuel ratio becomes lean due to the fuel supply control that conforms to the above, and the exhaust temperature tends to rise due to the retarded ignition timing and the lean air-fuel ratio, the above tendency is delayed to avoid knocking. Since the angle correction amount is indirectly known, and the fuel supply amount is increased according to the retard correction amount, the air-fuel ratio can be corrected to the rich side to prevent the exhaust temperature from rising, and the exhaust temperature It is possible to prevent melting loss of the three-way catalyst due to an abnormal rise and to prohibit the increase correction when the engine temperature is below a predetermined value, so that unnecessary increase correction is not performed. There is an effect. Further, there is an effect that it is possible to prevent the air-fuel ratio learning from being deteriorated at the time of the increase correction, and to prevent the accuracy of the air-fuel ratio learning from being deteriorated.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention, FIG. 2 is a system schematic diagram showing an embodiment of the present invention, and FIGS. 3 to 6 are respectively for ignition timing control and fuel supply control in the same embodiment. FIG. 7 is a flowchart showing related control contents, FIG. 7 is a diagram showing a conventional ignition timing control characteristic, and FIG. 8 is a diagram showing a relationship between ignition timing and exhaust temperature. 1 ... Engine, 6 ... Air flow meter, 8 ... Fuel injection valve, 9 ... Control unit, 10 ... Crank angle sensor, 11 ... Spark plug, 12 ... Ignition coil, 12a ... Power transistor, 13 …… Distributor, 14 …… Knocking sensor, 16 …… Oxygen sensor, 17 …… Three-way catalyst

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display F02P 5/153

Claims (2)

(57) [Claims] 1. An operating condition detecting means for detecting an operating condition of an internal combustion engine, a basic ignition timing setting means for setting a basic ignition timing based on the detected operating condition of the internal combustion engine, and a knocking occurrence of the internal combustion engine. Knocking detection means for detecting, ignition timing correction value setting means for increasing or decreasing the correction value of the basic ignition timing according to the presence or absence of detection of knocking occurrence by the knocking detection means, and the correction value of the set basic ignition timing Ignition timing setting means for correcting the set basic ignition timing based on the set ignition timing setting means, and an ignition signal output for outputting an ignition signal to an ignition device based on the set final ignition timing. In the internal combustion engine with a knocking control function, the delay time according to the correction value of the basic ignition timing set by the ignition timing correction value setting means is provided. Fuel increase correction means for increasing and correcting the fuel supply amount to the engine according to the angle correction amount, and increase correction prohibiting means for prohibiting the increase correction of the fuel supply amount by the fuel increase correction means when the engine temperature is below a predetermined value. A fuel supply control device for an internal combustion engine with a knocking control function, comprising: 2. An air-fuel ratio detecting means for detecting an air-fuel ratio of an engine intake air-fuel mixture, and a fuel supply amount so that an actual air-fuel ratio becomes a target air-fuel ratio based on the air-fuel ratio detected by the air-fuel ratio detecting means. Air-fuel ratio learning correction value setting means for learning and setting an air-fuel ratio learning correction value for correcting the air-fuel ratio learning correction value, and fuel supply amount to the engine based on the air-fuel ratio learning correction value learned and set by the air-fuel ratio learning correction value setting means. And an air-fuel ratio learning correction means for correcting the air-fuel ratio learning correction value, which prohibits learning setting of the air-fuel ratio learning correction value by the air-fuel ratio learning correction value setting means at the time of increasing correction by the fuel increase correction means. The fuel supply control device for an internal combustion engine with a knocking control function according to claim 1, further comprising means.