JP2002349408A - Ignition timing control apparatus for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition timing control apparatus for an internal combustion engine that can set the optimum ignition timing even when accelerating the internal combustion engine. SOLUTION: When it is determined that timing delay control on accelerating is for the first time in step S202, timing delay correction amount AACCB for a reference acceleration time is called from a map, in step S203. Then, in step S204, a learning value AKGi of a timing delay amount at the time of normal operation is multiplied by a predetermined coefficient K to obtain a multiplication value, and the multiplication value is reflected on the reference acceleration time timing delay correction amount AACCB called in the step S203 to calculated a final acceleration time correction value AACCG. Since learning value AKGi at the time of normal operation is reflected on the final ignition timing at the time of acceleration, influence of such as change with the lapse of time, octane number, or deposit is taken into consideration, and ignition timing can be accurately set even under an accelerating state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ignition timing control device for an internal combustion engine, and more particularly to an ignition timing control device for an internal combustion engine that controls the ignition timing during transient operation.

[0002]

2. Description of the Related Art As a control parameter affecting the combustion state of an internal combustion engine, there is an ignition timing set for a crank angle position. The ignition timing is determined based on MBT (Minimum Advance for) from the viewpoint of fuel efficiency and torque.
It is known that it is preferable to set the minimum spark advance required to generate the maximum shaft torque, which is referred to as “Best Torque”.

However, in controlling the ignition timing, it is impossible to set the ignition timing to the MBT under all operating conditions. One of the causes is knock. Knock is caused by an abnormality in flame propagation that propagates in the air-fuel mixture.For example, if the pressure in the cylinder becomes abnormally high during flame propagation, the air-fuel mixture self-ignites without waiting for flame propagation. The pressure increase caused by the rapid combustion causes the gas in the combustion chamber to vibrate, producing a tapping sound.

[0004] When knocking occurs, heat transfer is improved by combustion gas vibration. If the knocking state continues, the ignition plug electrode and the piston may be heated and melted, possibly damaging the engine. The ignition timing at which the knock occurs and the ignition timing (MBT) at which the maximum torque of the internal combustion engine is drawn are closely related, and the ignition timing MBT is near the ignition timing (knocking limit) at which knocking starts to occur. If knocking occurs at an ignition timing that is more retarded than MBT, the ignition timing cannot be set to MBT.

[0005] Further, the ignition timing at which knocking occurs varies with the aging of the combustion chamber and the injector, the deposit attached to the spark plug, or the octane number of gasoline. Generally, when the gasoline octane number is low, the knock generation ignition timing is retarded as compared with the case where the octane number is high. When there are many deposits, the ignition timing at which knock occurs is retarded compared to when there is no deposit.

For this reason, in the technology disclosed in Japanese Patent No. 2621396, learning correction is performed in accordance with the octane number in an operation region in which knock occurs due to a difference in octane number, and in a high rotation and high load region, the engine speed is reduced to a high rotation and high load. Knock control is performed by appropriate learning correction.

[0007]

However, in the above-mentioned prior art, accurate ignition timing control can be performed by learning correction in the steady operation state. However, in the acceleration operation state, the learning correction is performed for the following reasons. Can not be implemented.

It is difficult to accurately detect the air-fuel ratio and the ignition timing in the combustion chamber due to the delay in the measurement of the intake air amount by the air flow sensor and the delay in the measurement of the engine rotation speed. Even if accurate measurements can be made, the knocking state is different between the steady state and the transient state due to the difference in the combustion temperature of the combustion performed in the combustion chamber. As a technique, a technique is known in which a predetermined stored value stored in advance in a microcomputer or the like is called to retard the ignition timing. However, even if the ignition timing is retarded by a predetermined stored value, even if the occurrence of knock can be prevented, an appropriate torque may not be output due to excessive ignition timing retardation.

The technique disclosed in Japanese Unexamined Patent Publication No. 4-203266 is a technique for preventing drivability from being deteriorated in a transient state, and compares a change in rotational speed with a drivability constant corresponding to a shift position. Thus, a learning control for retarding / advancing the ignition timing is disclosed. However, in the technology disclosed in Japanese Patent Application Laid-Open No. 4-203266, deterioration of drivability can be prevented by learning control of the ignition timing based on comparison between a change in the rotational speed and a drivability constant corresponding to the shift position. Since no knock countermeasures are taken, knock may occur during transition.

[0010] The present invention has been made in view of the above-mentioned problems, and knocks are generated even when the internal combustion engine is in a transient state due to the effects of aging of the internal combustion engine and the like, octane number, deposits attached to a spark plug, and the like. It is an object of the present invention to provide an ignition timing control device for an internal combustion engine that can set an optimal ignition timing even when the ignition timing changes.

[0011]

According to the first aspect of the present invention, a basic ignition timing setting means for setting a basic basic ignition timing according to an operating state of an internal combustion engine, and whether or not knock has occurred is determined. A knock detecting means for detecting, and when a knock is detected by the knock detecting means, a retard amount for retarding a basic ignition timing set by the basic ignition timing setting means in accordance with an operating condition is calculated. In an ignition timing control apparatus for an internal combustion engine, comprising: a retard amount calculating means; and a learning value calculating means for storing a learning value of the retard amount based on the retard amount, wherein the operating state of the internal combustion engine is accelerating. When this is detected, the basic retard correction amount calculated by the acceleration basic retard correction amount calculating means is corrected based on the learned value of the learned retard amount. Then, the ignition timing at the time of acceleration operation of the internal combustion engine is calculated based on the corrected basic retard correction amount and the basic ignition timing set by the basic ignition timing setting means.

Thus, even if the ignition timing at which knock occurs during acceleration operation changes, the learned value of the retard amount with respect to the change in the knock point is reflected in the correction of the basic retard correction amount during acceleration operation. be able to. That is, a change in ignition timing at which knock occurs is caused by an octane number, a deposit adhering to a spark plug, a temporal change of a combustion chamber, an injector, and the like, and therefore, a learning value in a steady operation is updated by these effects. Becomes Therefore, by reflecting the learned value of the retard amount during the steady operation to the basic ignition retard correction amount during the acceleration operation, the optimal ignition timing is set for the change in the ignition timing even during the acceleration operation. can do. Therefore, it is possible to prevent the occurrence of knocking during the acceleration operation, and to prevent the ignition timing from being excessively retarded, thereby performing the optimum ignition timing control.

It is preferable that the value learned as the retard amount is stored for each operating region.

Thus, the learning value set for every operation region can be reflected in the correction of the basic retard correction amount during the acceleration operation, so that the basic ignition retard amount during the acceleration operation can be corrected more accurately. Can be implemented. Also, considering the learning frequency and the like, the learning frequency is higher in the load of the internal combustion engine or in the operating region where the engine rotation speed is low. good.

According to the third aspect of the present invention, it is preferable that the ignition timing correction period in the acceleration state is set based on the learned value of the retard amount to be learned.

By the way, the change in the ignition timing at which the knock occurs when returning from the acceleration operation to the steady operation gradually returns to the knock generation ignition timing in the steady operation state on the advance side due to the influence of the acceleration operation. For this reason, when returning from the acceleration operation to the steady operation, if the ignition timing is switched to the ignition timing control for the steady operation including the basic ignition timing and the retard correction for the basic ignition timing immediately after the return, knock occurs. Since the ignition timing is on the retard side from the knock point in the steady state, there is a possibility that knock may occur.

Therefore, it is preferable to set the return speed of the ignition timing correction in the acceleration state based on the learned value of the retard amount learned as in the invention of claim 4.

Further, in the case where a value on the advance side is set as an initial value of the learning value of the retard amount, the ignition timing control apparatus for an internal combustion engine according to any one of claims 1 to 3. In this case, if the initial value of the learning value is reflected in the basic ignition retard amount during the acceleration operation, knock may occur because the initial value of the learning value is a value on the advance side.

Therefore, in the ignition timing control apparatus for an internal combustion engine in which the advance value is set as the initial value of the learning value, the learning value of the retard amount is not learned. In some cases, a value corresponding to the maximum retard amount of the learning value is set, and the learning value that does not reliably generate knock is reflected in the basic retard correction amount during acceleration operation, thereby preventing knock from occurring. be able to.

It is preferable that the term "during acceleration operation" as in the invention of claim 6 includes the period from the beginning of acceleration.

As a result, the ignition timing according to the operating state can be set immediately when the acceleration operation is detected, so that accurate ignition timing control during the acceleration operation can be performed.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> A schematic configuration diagram to which an embodiment of the present invention is applied will be described below with reference to FIG. FIG. 1 shows an overall configuration diagram of an internal combustion engine 10 including a knock suppression control device. In the intake passage 12 of the internal combustion engine 10,
Intake pressure sensor 1 for detecting the air pressure flowing through the inside
4. an intake air temperature sensor 16, which detects the temperature of the flowing air;
A throttle valve 18 for controlling the amount of flowing air and an injector 20 for supplying fuel into the intake passage 12 are provided.

The throttle valve 18 is a valve element that operates in conjunction with an accelerator pedal (not shown), and an idle switch 22 for detecting a fully closed state of the throttle valve 18 is provided near the throttle valve 18. In addition, a bypass passage 24 that bypasses the throttle valve 18 is provided in the intake passage 12. The bypass passage 24 is provided to flow air that can maintain the internal combustion engine 10 in an idle state when the throttle valve 18 is fully closed, and uses, for example, a step motor or the like as a drive source. Idle speed control valve (ISC
V) 26 controls its conduction state.

A water jacket 30 is provided in the cylinder block 28 of the internal combustion engine 10 in order to cool the engine by flowing cooling water. And
A water temperature sensor 32 is provided on the side wall of the water jacket 30 to detect the temperature of the cooling water flowing inside the water jacket 30.

Above the piston 31 which slides up and down in the cylinder block 28, there is formed a combustion chamber 36 in which a spark plug 34 protrudes. This combustion chamber 36
Communicates with the above-described intake passage 12 via an intake valve 38 and communicates with an exhaust passage 42 via an exhaust valve 40.

The exhaust passage 42 has an oxygen concentration sensor 44 for detecting the concentration of oxygen contained in the exhaust gas flowing therethrough, and a catalytic device 46 for purifying unburned components in the exhaust gas.
Is provided. The catalyst device 46 is provided with a catalyst bed temperature sensor 48 for detecting the internal temperature.

The igniter 50 shown in FIG. 1 cuts off the current supplied to the primary winding of the ignition coil 51 installed on the upper part based on a drive signal supplied from an electronic control unit (ECU) 60. . As a result, the ignition coil 5
In the secondary winding of No. 1, in synchronization with the drive signal of the ECU 60,
High voltage back electromotive force is generated. Then, the high voltage signal generated in the ignition coil 51 in this way is supplied to the distributor 52 as an ignition signal.

The distributor 52 operates in synchronization with a crankshaft (not shown), and
The ignition signal supplied from 1 is distributed to the ignition plug 34 of a specific cylinder according to the rotation angle. Therefore, the ignition signal generated by the ignition coil 51 is supplied only to the ignition plug 34 of the cylinder to be ignited according to the crank angle of the internal combustion engine 10.

By the way, the distributor 52 includes:
A cylinder discrimination sensor 54 for generating a reference position detection signal for the crankshaft, and an internal combustion engine rotation speed signal of, for example, 30 ° C.
A rotation angle sensor 56 that is generated every time is provided. Then, the ECU 60 determines the igniter 5 based on the cylinder discrimination signal ignition signal and the rotation angle signal supplied from these.
A drive signal is issued at an appropriate timing to 0.

In this embodiment, a vehicle speed sensor 62 for generating a pulse signal having a cycle corresponding to the vehicle speed, a neutral switch 64 for detecting that a transmission (including an automatic transmission) is in a neutral state, and an air conditioner ( An AC switch 66 that indicates the operating state of an air conditioner, a brake switch 67 that detects the operation state of a brake pedal,
An AC pressure sensor 68 for detecting a compressor pressure of the air conditioner is connected to the ECU 60.

FIG. 2 is a block diagram showing a hardware configuration around the ECU 60. As shown in FIG. As shown in FIG.
The CU 60 converts an output signal of the various sensors into a predetermined digital signal and takes in the digital signal, an output port 70 for issuing a control signal to the injector 20, the ISCV 26, and the igniter 50, a CPU 72, a RAM 74, and an RO.
An M76, a backup RAM 78, and a common bus 80 connecting these to each other so as to be able to communicate with each other.

The ignition timing control of the present embodiment in the internal combustion engine 10 configured as described above will be described. The ROM 76 stores the basic ignition timing ABSEI shown in FIG.
An H map, a control routine program described below, and the like are stored in advance.

First, a routine for calculating the effective ignition timing θ will be described with reference to FIG. In step S101, it is determined whether or not the current operation region is a region where knocking occurs. For example, as a determination condition, the condition that the operation region is where knocking occurs is the idle switch 2
2 is off, the target engine speed Ne is high,
Alternatively, at a low rotation speed, the cooling water temperature Thw detected by the water temperature sensor 32 satisfies that the water temperature is equal to or lower than a predetermined water temperature and the battery voltage is equal to or lower than a predetermined value.

If it is determined in step S101 that the vehicle is in the operating range where knocking occurs, step S102 is performed.
The process proceeds to the subsequent processing to execute knock control. On the other hand, if it is determined in step S101 that it is not in the knock control region, the process proceeds to step S106, where the basic ignition timing ABSE is input as the effective ignition timing θ, and this routine ends. Here, as the basic ignition timing ABSE, the basic ignition timing ABSEIH called by the basic ignition timing map of FIG. 4 is set as the ignition timing according to the operating state.

If it is determined in step S101 that the operation region is the knock control region, the process proceeds to step S102. In the processing after step S102, as a method of knock control, the basic ignition timing ABSE described above is
The effective ignition timing θ is calculated using a learning value AKGi and a corrected retardation amount AKCS described later. First, in step S102, it is determined whether or not knock has occurred by comparing the peak value of the frequency band unique to knock with the determined level. The knock determination method may be a conventionally known method, and will not be described in detail here.

Here, when the peak value is larger than the determination level, it is determined that knock has occurred, and step S105 is performed.
And the correction retard amount AKCS is set to a predetermined value (for example, 1 [°
CA]). On the other hand, when it is determined that the peak value is equal to or less than the determination level, it is determined that knock has not occurred, and the process proceeds to step S103. Step S103
Then, it is determined whether or not a predetermined number of ignitions (for example, 10 ignitions) or a predetermined time has elapsed. If the predetermined number of ignitions has elapsed, the process proceeds to step S104, and the correction retard amount AKCS is set to a predetermined value (for example, 1 [° CA])
Proceed to 107. On the other hand, if the predetermined number of ignitions has not elapsed, step S104 is bypassed and step S107 is performed.
Proceed to. As described above, the correction retard amount AKCS is set so as to advance or retard the correction amount for the basic ignition timing ABSEIH according to whether or not knock has occurred.

Next, in step S107, based on the load of the internal combustion engine 10 (for example, the intake air amount Q [Q / Ne] with respect to the engine rotation speed Ne) and the engine rotation speed Ne, the current operation region becomes the learning region. It is determined to which region it belongs. As shown in FIG. 5, this learning region is a region where the load [Q / Ne] of the internal combustion engine 10 is equal to or more than a predetermined value, and is divided into, for example, six for each engine rotation speed Ne. AKG1, AKG2, ... AK
Gi,... AKG6 are defined respectively, and a value corresponding to the maximum retard amount is stored as an initial value in each learning value AKGi in order to prevent knocking. When the learning region is determined from the driving region in this way, step S1
Proceed to 08.

In step S108, step S107
It is determined whether or not the driving area has entered the learning area for the first time, and if it is determined that the driving area has entered for the first time, step S10
Go to 9. In step S109, a value obtained by subtracting a predetermined value (for example, 2 [° CA]) from the initial value of the learning value AKGi corresponding to the learning area determined in step S107,
A comparison is made with the corrected retard amount AKCS set in step S104 or step S105. As a result of this comparison, if the retardation correction amount obtained by subtracting a predetermined value from the initial value of the learning value AKGi is larger than the correction retardation amount AKCS, the process proceeds to step S112.

In step S112, a large value as a correction amount of the retard amount, that is, a retard correction amount obtained by subtracting a predetermined value from the initial value of the learning value AKGi is input to the corrected retard amount AKCS and updated. On the other hand, in step S109, the learning value A
If it is determined that the retard correction amount obtained by subtracting the predetermined value from the initial value of KGi is smaller than the correction retard amount AKCS set in step S104 or step S105, step S112 is bypassed and step S11 is performed.
Proceed to 3.

In step S113, the learning value and AKGi
And the retardation correction amount obtained by subtracting a predetermined value from the initial value of
04 or the corrected retard amount AKCS set in step S105 is selected as the larger retard amount, the selected retard amount is stored in the learning value AKGi, and the process proceeds to step S114.

In step S108, step S107
If it is determined that the driving area is not the first time in the learning area determined in the above, the process proceeds to step S110, and step S1 is performed.
04 or the corrected retardation amount AKCS set in step S105 is compared with the learned value AKGi. here,
When the corrected retard amount AKCS is larger than the learned value AKGi, in step S111, the corrected retard amount AKCS is input to the learned value AKGi, the learned value is updated, and the process proceeds to step S114. On the other hand, if it is determined in step S110 that the learning value AKGi is large, the process proceeds to step S114.

In step S114, the effective ignition timing θ is calculated by subtracting the retardation correction amount AKCS from the basic ignition timing ABSE described above, and this routine ends. In this manner, when the knock occurs, the retard amount is set to be larger by 1 [° CA], and when the knock does not occur, the corrected retard amount AKCS is set to be smaller by 1 [° CA]. Further, in the setting of the learning value AKGi, the learning value A
By comparing KGi with the corrected retard amount AKCS, the larger retard correction amount is always updated as the learning value AKGi. Also, when the value of the correction retardation amount AKCS is a value on the advance side, a large advance value is set as the learning value.

Next, the ignition timing calculation program during the acceleration operation will be described with reference to the routine of FIG. This routine is a routine showing a characteristic portion of the present invention, and the learning value AK for each set operation region is set in the flowchart of FIG.
It is characterized in that the ignition timing retard amount during transition is set based on Gi. The details will be described below with reference to FIG. First, in step S201, a condition for executing retard control during acceleration is determined. The retard control at the time of acceleration is performed when all of the following execution conditions are satisfied. When the execution conditions are not satisfied, the routine is terminated as it is.

(1) Not during a shift change (2) After or during execution of rapid acceleration control (3) During acceleration When all of the above execution conditions are satisfied, the process proceeds to step S202, and the acceleration is delayed. It is determined whether or not the angle control is being executed. Then, when the retard control during acceleration is not being executed, that is, in the first time of the retard control during acceleration, the process proceeds to step S203 and thereafter to calculate the retard amount of the ignition timing. In step S203, the basic ignition retard amount A during the acceleration operation is determined from the engine speed Ne and the change amount ΔTh of the throttle opening from the map shown in FIG.
Call ACCB. Then, the process proceeds to step S204 to calculate the final acceleration correction amount AACCG. The final acceleration correction amount AACCG is calculated based on the ignition timing correction amount storage value AKGi stored by the program of FIG. The calculation method is, for example, a value obtained by adding or subtracting a value obtained by multiplying the learning value AKGi by a predetermined coefficient K to or from the basic ignition timing retard correction amount AACCB, and calculating a final acceleration correction amount AACC.
G may be used, or calculation may be performed by multiplication.

Next, at step S205, the learning value A
A predetermined value CONST1 is set based on KGi. Here, the predetermined value CONST1 corresponds to a period during which the ignition timing retard control performed during the acceleration operation is performed. This predetermined value C
After setting DLY, the process proceeds to step S206. In this manner, at the first time of the acceleration retard control, the basic acceleration retard correction amount AACCB is corrected based on the learning value learned in the steady operation state, so that the final correction amount during the acceleration operation is obtained. Calculate AACCG.

The processing after the first time of the retard control at the time of acceleration is performed by the processing after step S207 in which it is determined in step S200 that the retard control at the time of acceleration is being executed. In step S207, the counter CDLY counts the predetermined value C
It is determined whether or not ONST1 has been exceeded. Here, if it is determined that it has not exceeded, the process proceeds to the process of step S209.

In step S209, the correction amount AACCG at the time of the last final acceleration is changed to the correction amount AACCG at the time of the current final acceleration.
And Then, the process proceeds to step S210, where the counter C
DLY is incremented, and the process proceeds to step S206.
That is, the predetermined value CONST1 set based on the learning value AKGi sets a period during which the final acceleration correction amount AACCG is held at the final final acceleration correction amount AACCG, and returns from the acceleration operation to the steady operation. In this case, knocking is prevented.

On the other hand, at step S207, the counter CD
If it is determined that LY has exceeded the predetermined value CONST, the process proceeds to step S207, and a smoothing process for returning the ignition timing based on the learned value AKGi is performed. That is, in order to return from the final acceleration correction amount AACCG set at the time of acceleration to the basic ignition timing in a steady state, a smoothing process (return control) is performed on the final acceleration correction amount AACCG during acceleration operation. Thus, when returning from the acceleration operation to the steady operation, it is possible to prevent occurrence of knock due to switching to the ignition timing control based on the basic ignition timing and the ignition timing correction based on the retard correction for the basic ignition timing immediately after the return.

Next, each parameter for determining the ignition timing according to the present embodiment will be described with reference to a time chart of FIG. 9 for each parameter. In FIG. 9A, at the point A in the figure, the operation state of the internal combustion engine shifts to the acceleration operation, and it is determined that the internal combustion engine is not performing a shift change or that the rapid acceleration control is being performed. This indicates that the condition is satisfied. When the above condition is satisfied at the point A, the ignition timing retard control during the acceleration operation is performed.

FIG. 9B shows the final ignition timing. The ignition timing retard control during the acceleration operation is performed from the point A in FIG. 9A. Thereafter, at point A in FIG.
The ignition timing retard control during the acceleration operation is performed until the counter CDLY shown in (c) is set and the counter CDLY becomes 0. When the ignition timing retard control ends, a return control for returning the ignition timing according to the operating state to the normal ignition timing is performed.

The ignition timing during such final acceleration operation includes a basic ignition timing during normal operation and a final acceleration correction amount A
ACCG, and the final acceleration correction amount AACCG is
The basic acceleration correction amount AACCB shown in FIG.
It is calculated by the correction amount obtained by multiplying the learning value AKGi in the steady operation shown in (d) by a predetermined coefficient.

In the time chart of FIG. 9, although the end points of the acceleration judgment and the ignition timing retard control during acceleration coincide, the ignition timing retard control is performed by the counter C corresponding to the learning value.
This is not the case because it is set by DLY. The value may be set by a predetermined value other than the counter CDLY.

As described above, in this embodiment, the correction amount AACCG at the time of final acceleration is calculated based on the learning value AKGi set at the time of steady operation, so that the change over time of the internal combustion engine, the octane number of the fuel, and the injector It is possible to accurately set the final acceleration correction amount AACCG even when the ignition timing changes due to the occurrence of knocking during acceleration operation due to the adhesion of the deposit, to reliably prevent knocking and to set the accurate ignition timing. Can be implemented.

In the present embodiment, the basic ignition timing setting means is shown in the map of FIG. 4, and the basic retard amount calculating means for acceleration is shown in the map of FIG. 7 and step S of the flowchart of FIG.
205 and the final ignition timing correction amount calculating means correspond to step S206 in the flowchart of FIG.

<Second Embodiment> In the first embodiment, as the initial value of the learning value AKGi shown in FIG. 5, the ignition timing retard amount corresponding to the maximum retard amount so that knock does not occur. Was set. In the present embodiment, the advance-side correction amount is set as the initial value of the learning value AKGi. Thus, the learning value AKG learned in the steady operation state
If the initial value of i is set to a value on the advance side, the learning value AKG is used for correcting the basic retard correction amount during acceleration operation.
Knock may occur due to the reflection of the initial value of 1. Therefore, the present embodiment aims at preventing the occurrence of knock during acceleration operation in an ignition timing control device for an internal combustion engine in which the initial value of the learning value AKGi is set to a value on the advanced side as shown in FIG. This will be described with reference to the flowchart shown in FIG. The same steps as those in the flowchart of FIG. 6 are denoted by the same reference numerals, and description thereof will be omitted.

If it is determined in step S201 that the condition for executing the retard control during acceleration is satisfied, the process proceeds to step S301, in which the engine speed Ne becomes the learning value AKG1 on the low rotation side.
It is determined whether or not has already been learned. If the learning has been completed, the process proceeds to step S202, and it is determined whether the acceleration retard control is being executed. Subsequent processing is the same as in the first embodiment, and a description thereof will not be repeated.

On the other hand, if it is determined in step S301 that the learned value AKG1 has not been learned, the process proceeds to step S301.
Go to 302. In step S302, the learning value AKG1
The maximum value of the retard amount is input as the value corresponding to the maximum retard amount, and the process proceeds to step S202.

As described above, even when the initial value on the advance side is set as the learning value AKG1, the learning value AKG1
By inputting the maximum value on the retard side to the initial value of, the ignition timing can be corrected so that knock does not occur even during acceleration operation.

In step S304, of the learning value AKGi, the final acceleration correction amount AAC is calculated using the learning value AKG1 of the engine rotation speed Ne in the low rotation speed region.
Calculate CG. This is because, in consideration of the learning frequency of the learning value AKGi and the like, the frequency of updating the learning value is higher in the operating region where the engine speed of the internal combustion engine is lower, so that the learning value in the operating region at the lower rotation speed is AKG1 or AACCG at the time of final acceleration using only AKG2
Is calculated.

That is, since the maximum retardation amount is set as the initial value for the learning value AKGi, the learning value AKGi in the operating region of the high engine rotation speed Ne often remains at the initial value. If this value is used as the retard correction amount during the acceleration operation, an unnecessarily large retard amount is set, which may cause unstable combustion or a significant decrease in torque. On the other hand, the learning value AKG1 is set to a retard amount that reflects the secular change of the internal combustion engine, the octane value of the fuel, the adhesion of the deposit to the injector, and the like. Even if the learning value AKG1 is used as a correction value for the previous operation region, knock control during acceleration operation can be performed without losing accuracy.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of the present invention.

FIG. 2 is a block diagram of an electronic control unit (ECU) of the present invention.

FIG. 3 is a main flowchart of the first embodiment.

FIG. 4 is a map for setting a basic ignition timing.

FIG. 5 is a learning value AKG of a retard amount learned for each driving region.
i-map

FIG. 6 is a flowchart of retard control during acceleration operation according to the first embodiment;

FIG. 7 is a map for setting a basic ignition timing retard amount during an acceleration operation based on a change amount of a throttle opening and an engine speed in the first embodiment.

FIG. 8 is a flowchart of retard control during acceleration operation according to the second embodiment.

FIG. 9 is a time chart of the ignition timing in the first embodiment.

[Explanation of symbols]

 Reference Signs List 10: internal combustion engine, 12: intake passage, 16: intake temperature sensor, 26: ISCV, 32: water temperature sensor, 34: spark plug, 36: combustion chamber, 60: electronic control unit (ECU)

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hideki Yukimoto 1-1-1, Showa-cho, Kariya-shi, Aichi Pref. F term in DENSO Corporation (reference) 3G022 CA04 DA02 EA02 FA00 GA01 GA05 GA09 GA10 GA13 GA18 GA20 3G084 BA06 BA17 CA04 DA38 EA07 EA11 EB00 EB08 EB24 FA03 FA06 FA18 FA20 FA25 FA27 FA33 FA38

Claims (6)

[Claims] 1. A basic ignition timing setting means for setting a basic basic ignition timing according to an operation state of an internal combustion engine, a knock detection means for detecting whether or not knock has occurred, and a knock by the knock detection means. Is detected, a retard amount calculating means for calculating a retard amount for retarding the basic ignition timing set by the basic ignition timing setting means in accordance with the operating condition; and An ignition timing control device for an internal combustion engine, comprising: a learning value calculating means for storing a learning value of a retardation amount when detecting that the operating state of the internal combustion engine is accelerating. An acceleration basic retard correction amount calculating means for calculating a correction amount; and a basic retard correction amount calculated by the acceleration basic retard correction amount calculating means, the basic retard correction amount calculated by the learning value calculating means. Based on learning value And a basic ignition timing set by the basic ignition timing setting means. An ignition timing control device for an internal combustion engine, which calculates an ignition timing during an acceleration operation of the engine. 2. The ignition timing control device for an internal combustion engine according to claim 1, wherein the learning value of the retard amount stored by the learning value calculation means is learned for each operation region. 3. The internal combustion engine according to claim 1, wherein an ignition timing correction period in an acceleration state is set based on the learned value of the learned retard amount. Ignition timing control device. 4. The return speed of ignition timing correction in an accelerated state is set based on a learned value of a retard amount learned for each operation region. An ignition timing control device for an internal combustion engine according to one of the aspects. 5. An ignition timing control device for an internal combustion engine in which an advanced value is set as an initial value of the learning value, wherein a maximum retardation of the learning value is provided when the learning value of the retard amount has not been learned. The ignition timing control device for an internal combustion engine according to any one of claims 1 to 5, wherein a value corresponding to the amount is set. 6. The ignition timing control device for an internal combustion engine according to claim 1, wherein the term “in acceleration operation” includes a period from an initial stage of acceleration.