JPS61229959A - Control device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To enhance the operability by interrupting the correction control of ignition timing due to the position of crank angle during the transient period after the load change of an engine has exceeded a prescribed value and carrying out the correction control of air-fuel ratio so that the position of crank angle may coincide with a target value. CONSTITUTION:When the air-fuel ratio is lean, the combustion speed becomes slow and thetapmax (the position of crank angle in which the pressure in the cylinder is maximum) becomes large, and on the contrary, when this is rich, thetapmax becomes small. Now, when the load change exceeding a prescribed value occurs, the prescribed period during which the change is anticipated to continue starting from the beginning is made a transient period. And during the time the correction control of ignition timing by an ignition timing control means C is interrupted, and the correction control of air-fuel ratio by an air-fuel ratio correction means F is carried out. By this means thetapmax is made to coincide with a target value thetapmaxo. Thus, the variation of air-fuel ratio during a transient period can be reduced, and consequently the torque fluctuation can be reduced.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a control device for an internal combustion engine, and in particular to a control device for controlling an internal combustion engine so that the maximum crank angle position of the cylinder pressure generated in each combustion cycle of the engine always becomes the best fuel efficiency point. The present invention relates to a device for controlling ignition timing and air-fuel ratio.

[Conventional technology]

Various studies have been conducted to improve fuel efficiency by controlling the ignition timing of internal combustion engines. A specific angle after dead center (approximately 10
It is known that the output of one engine can be maximized by controlling the ignition timing so that the engine speed is between 20 and 20 ATDC, thereby minimizing the fuel consumption rate.

Regarding this technology, for example, 1. “Power system, measurement.

and control journal J (Journal of D
dynamicSystem, Measurmen
t, and Control )1 9 7
6 December issue P, 414-420. Or “Society of Automotive Engineers (SAE) Report No. 790139
It is introduced by etc.

Such a conventional ignition timing control device is constructed as shown in FIG. 8, for example.

To explain this simply, 1 is a θpmax detector that detects the maximum cylinder pressure rank angle IE (hereinafter referred to as θpmaxJ), which inputs the cylinder pressure signal and crank angle position signal to cycle the combustion cycle of each cylinder. θpma every
Detecting x 2 is an in-cylinder pressure sensor provided in each cylinder, and is attached to the cylinder head together with the ignition plug, for example, like a washer for the ignition plug. The pressure inside the cylinder is then converted into an electrical signal by a piezoelectric element and detected.

A reference signal generator 3 generates a reference pulse signal S1 that rises at a compression top dead center of each cylinder or at a predetermined crank angle (for example, 70'' aroc) before the compression top dead center.

In the case of a four-cylinder engine, a rising pulse is generated every time the crankshaft rotates 180 degrees.

4 is a 10 signal generator that generates a pulse signal S2 that rises and falls every time the crankshaft rotates 1''. θpa+
The ax detector 1 receives these two signals S1 and S2 and determines the rotational position of the crankshaft.

Reference numeral 5 denotes a target value setter, which sets the target value θ of θpmax, which has been determined and stored in advance for the engine through experiments, etc.
Read and set psax□ (predetermined crank angle between 10@ and 20” ATDC).

6 is a comparator, and θp given from θpHaX detector 1
maX and the target value θpma given from the target value setter 5
xo and the result is θpmax) θpmax.

If so, “+”, if θpwsax<θpHaXo.

"-", "0" if θpraax = θpmaxo
Outputs a signal indicating.

7 is a basic ignition timing calculator which calculates the basic injection amount Tp of fuel by inputting the rotational speed and load of the engine.

The basic ignition timing SAo is determined and output by reading a table from a memory storing three-dimensional data as shown in FIG.

8 is a rotational speed detector that detects the rotational speed N of the engine, and numeral 8 is a load detector that detects the load state of the engine based on the intake pipe negative pressure or the intake air amount Qa.

10 is a corrector which adjusts the correction amount Δ according to the signal from the comparator 6.
Find SA. For example, when the signal from the comparator 6 is +, ΔSA=ΔSA(previous)+a.

- When ΔSA = ΔSA (previous) - a, when 0
Let ΔSA=ΔSA (previous time). Here, raJ is a predetermined positive value.

The correction amount ΔSA obtained in this manner is added to the basic ignition timing SA calculated by the basic ignition timing calculator 7 to obtain the ignition timing SA (SA=SA, +ΔSA).

The ignition circuit 11 uses a reference signal S1 and a crank angle position according to the ignition timing SA given by the corrector 10.
It is determined based on the signal S2 and an ignition signal is generated at the ignition timing.

[Problem that the invention seeks to solve]

However, in such a conventional ignition timing control device for an internal combustion engine, the ignition timing is controlled so that θpmax matches the target value even during a transient period when the load condition of one engine changes.

However, with the air flow meter installed in front of the throttle valve, which is a well-known engine load detection means, during a transient period, the intake air amount Qa remains constant until the inside of the manifold from the throttle valve to the intake valve reaches a steady value. It has the characteristic of weighing more or less.

Therefore, when shifting to a high load, the detected value of the intake air amount Qa changes as shown in Fig. 10 (b) in response to a change in the opening of the throttle valve as shown in Fig. 10 (a), resulting in an overshoot. During this period, the air-fuel ratio becomes enriched as shown in FIG.

Further, immediately before the start of the transition, the air-fuel ratio becomes lean due to the delay in fuel supply.

In this way, the air-fuel ratio fluctuates rapidly during transient periods.

Therefore, the combustion state within the cylinder also varies greatly, and as shown in FIG. 10(d), the variation of θpmax is also large.

Therefore, even if the ignition timing is controlled so that θp■aX matches the target value during this period, it will reach the best fuel efficiency point, maximize efficiency, and obtain maximum torque, so torque fluctuations due to air-fuel ratio fluctuations will occur. There was a problem in that this resulted in an increase in drivability and deteriorated drivability.

There is also the problem that knocking is more likely to occur due to air-fuel ratio fluctuations.

The present invention solves these conventional problems and reduces air-fuel ratio fluctuations during transient periods, reducing θpm.
The purpose is to enable control so that aX reaches the best fuel efficiency point (target value).

[Means for solving problems]

As shown in the functional block diagram in FIG. 1, the present invention includes a θpaax detection means A that detects the crank angular position θpmax at which the cylinder internal pressure is maximum in each combustion cycle of an internal combustion engine, and a θpaax detection means A that detects the θpmax detected thereby. Comparison means B that compares with a predetermined target value θpwaxo, and ignition timing correction means C that corrects and controls the ignition timing so that θpmaX matches θpmaxo according to the comparison result.
In order to solve the above-mentioned problems in a control device for an internal combustion engine, the present invention includes a load state detection means for detecting a load state of the engine.

Transient period determining means E for determining a transient period when the change in load detected by said means exceeds a predetermined value; and air-fuel ratio correcting means F for correcting and controlling the air-fuel ratio of the air-fuel mixture supplied into the cylinders of one engine. Then, the ignition timing correction control by the ignition timing correction means C is interrupted while the transition period is determined to be a transient period by the transient period determination means E, and the detected value of θpmax by the air-fuel ratio correction means F matches the target value θpmaxo. A correction switching means G for correcting and controlling the air-fuel ratio is provided.

[For production]

As already mentioned, the air-fuel ratio changes as shown in FIG. 10(c), which occurs during a transient period when the engine load condition changes. On the other hand, when the ignition timing is kept constant, θpma
The fluctuation of x is as shown in FIG. 2(d). In other words, when the air-fuel ratio is lean, the combustion speed becomes slower, so θP■a
X becomes larger, and in the case of rich fuel, the combustion speed becomes faster, so θpWaK becomes smaller.

Therefore, in the internal combustion engine control device according to the present invention, when there is a load change of more than a predetermined value.

A predetermined period during which the fluctuation is expected to continue from the start is defined as a transition period, during which the ignition timing correction control by the ignition timing correction means C is interrupted, and the air-fuel ratio correction control is performed by the air-fuel ratio correction means F.

The objective is achieved by making θpmax match the target value opHaXo.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 2 to 7 of the drawings.

FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention, and the same parts as in FIG. 8 are denoted by the same reference numerals, and their explanation will be omitted.

12 is a basic injection amount calculator, which detects the intake air amount Qa according to the engine load detected by the load detector S and the rotation speed 1.
) 8, the basic injection amount Tp is determined from the engine rotational speed N (rp) detected by the following equation, for example, every time the 8-fold reference signal is input.

Tp=to-Qa/N (K is a constant) ・(1)13
is the previous basic injection amount Tp calculated by the basic injection amount calculator 12 based on the change in the load condition of one engine by the transient period determiner.
It is determined by the difference ITp-TpBl or the ratio TpB/Tp between m and the current basic injection amount 'rp, and when the difference or ratio is greater than a predetermined value (for example, a value of 2m5ec or more in the case of a difference), switching is performed. After the above condition ends, the output is maintained for a predetermined period (this period is determined by time or the number of revolutions of the crankshaft), and then the output is set to 0. Make it.

That is, if it is determined that it is a transition period, it outputs 1'',
When it is determined that it is not a transition period, it outputs "0". In the illustrated example, the reference signal S1 is input.

After the above conditions are completed, the crankshaft rotates a predetermined amount (for example, 10
The output is held at "work" until it rotates).

Reference numeral 14 denotes a switch, which switches the output to the corrector 10 or 15 according to the input (+, -0) from the comparator 6 and the input (1, 0) from the transient period determiner 13.

That is, when the input from the transient period determiner 13 is 0' (when it is not a transient period), the output (+t'--o) of the comparator 6 is output as is to the corrector 10, and the corrector For 15, "0" is output. When the input from the transient period determiner 13 is 1'' (during the transient period), "0" is output to the corrector 10, and the comparator date output C+1 + to the corrector 15, o) is output as is.

The functions of the corrector 10 and the ignition circuit 11 are the same as those of the conventional example shown in FIG. 8, so their explanation will be omitted.

15 is a corrector for correcting and controlling the air-fuel ratio.

Basic injection amount T calculated by basic injection amount calculator 12
The injection amount Ti is determined from p using the following equation.

Ti = T p X a + T s
-(2) Here, α is an air-fuel ratio correction coefficient, and Ts is a correction amount based on battery voltage.

When the input from the transient period determiner 13 to the corrector 15 is not a transient period of 0'', normal air-fuel ratio control is performed. In this case, normal air-fuel ratio control to obtain the air-fuel ratio correction coefficient α is as follows. For example, there is air-fuel ratio feedback control using a 02 sensor.

When the output of the transient period determiner 13 is a transient period of 1″,
Stop normal air-fuel ratio control and calculate the air-fuel ratio correction number α at that time.
The transient air-fuel ratio control starts from .

That is, when the output of the switch 14 is "+".

Since combustion is delayed, the air-fuel ratio is enriched by setting α=αB+ΔαR (3). When it is "-", combustion is fast, so the air-fuel ratio is made lean by setting α=αB-ΔαL (4). This calculation is performed in synchronization with fuel injection. Note that in the above equation, αB is the previously determined air-fuel ratio correction coefficient, and ΔαR and ΔαL are positive constants.

When the output of the switch 14 is "0", the previous correction coefficient is held.

α=αB (5) On the 1st, the combustion valve drive circuit generates a fuel valve drive signal according to the injection amount Ti obtained by the corrector 15, and drives the fuel valve.

By correcting and controlling the air-fuel ratio of the air-fuel mixture supplied into the cylinders of one engine in this way, θρmax detected by the θpmax detector 1 matches the target value θpmax0 set by the target value setting device 5. to control combustion.

During the transient period, the corrector 10 does not change the aforementioned ΔSA because the signal from the switch 14 is always rOJ.

Therefore, the ignition timing SA is also not changed.

In this embodiment, θpmax detector 1° comparator 6. Transient period determiner 13. and the switch 14 are the θpmax detection means A in FIG. 1, respectively.

Comparison means B, transient period determination means, and correction switching means G
Corresponding to They correspond to the correction means F, respectively.

3@ and 4 show flowcharts when a device similar to this embodiment is realized by software using a microcomputer.

This program is executed in synchronization with fuel injection and ignition.

When the program shown in Figure 3 starts, first step 1
OPHaX is detected (details will be described later), and in step 2, the basic injection amount Tp is calculated based on equation (1).

Next, in step 3, the basic injection amount Tp calculated this time is compared with the previous basic injection amount TpB, and if it is determined that the difference is greater than a predetermined value (for example, 2 m5ec), the process proceeds to step 8, which will be described later. Otherwise, proceed to step 4 and FLA
If G is 1'', the process proceeds to step 9, but if it is O'', the process proceeds to step 5, where a normal air-fuel ratio correction coefficient is calculated.

Furthermore, the process proceeds to step 6, where the current air-fuel ratio correction coefficient α is stored in the αB register and the basic injection amount TP is stored in the TpB register, and the injection amount T1 is calculated based on equation (2). Ti for the fuel valve drive circuit
Output the value.

In step 3, 1Tp-TpBI≧2m5e
If it is determined that there is a transient state such as c, the T counter is cleared in step 8, and FLAG is set to 1'', and the process proceeds to step 12.

Further, if FLAG is determined to be 1'' in step 4, the value of the T counter is set to ``1'' in step 9, and then the value of the T counter is set to a predetermined value (for example, rl
If the value is 10 or more, the process proceeds to step 11, and after setting FL and AG to O'', normal air-fuel ratio calculations from step 5 onwards are performed.

If the value of the T counter is less than 10 in step 10, the process proceeds to step 12.

Therefore, the transient state (ITp-TPBI≧2m5ec
) is detected, the air-fuel ratio correction from step 12 onwards is performed for a predetermined period, and otherwise the normal air-fuel ratio correction from step 5 onwards is performed.

Step 12 and subsequent steps operate as follows.

First, in step 12, θpIl obtained in step 1
Compare ax with the target value θpmaxo (a specific angle in the range of 10 to 20° ATDC) and find that θpmax is smaller.
-'', it is determined that combustion is fast and the process proceeds to step 13, where the air-fuel ratio is made lean based on equation (4).

If θpmax is larger (+), it is determined that combustion is slow, and the process proceeds to step 14, where the air-fuel ratio is enriched based on equation (3). Furthermore, θp+saz and θpma
If xo is equal to "0", the current status is maintained without doing anything.

After this, execute step 6.7 and add Ti to the fuel injection circuit.
Output the value.

FIG. 4 shows the ignition timing correction routine. When this program starts, first in step 15 the above-mentioned FLA
If G is 0" (i.e. outside the transition period), step 16
Then, θpmax is compared with the target value θpmaxo.

And if θpma is larger "+".

It is determined that the ignition timing is delayed and the process proceeds to step 17.
A predetermined value a (for example, 1") is added to the previous correction value ΔSA to advance the current correction value, and the process proceeds to step 19. Furthermore, if epHaX is smaller [-", the ignition timing is advanced. When it is determined that the current correction value is correct, the process proceeds to step 18, where a predetermined value a is subtracted from the previous correction value ΔSA to retard the current correction value, and the process proceeds to step 19. Furthermore, θpraax and θp
If HaXo is the same, proceed directly to step 19. Therefore, the correction value ΔSA at this time maintains the previous value.

In step 19, the basic ignition timing SAO is determined depending on the operating conditions.
Further, in step 20, the correction value ΔSA is added to obtain the ignition timing SA, the current correction value ΔSA is stored in the ΔSA (previous) register, and the ignition timing SA is output to the ignition circuit in step 21.

Here, the subroutine for detecting θpmax in step 1 of FIG. 3 will be explained with reference to FIGS. 5 and 6.

FIG. 5 is a flowchart of a program for detecting θpmax in an embodiment of a four-cylinder engine.

This θp+wax detection program is composed of three types of programs shown in (a), (b), and (c).
(a) is executed once every 720 degrees (that is, the rotation angle required for 4 strokes of a 54-cycle engine), (b) is executed every time the reference signal is input, and (c) is executed every 1 degree. .

The timing at which this program is executed is synchronized with the signal of the engine crank angle position detection la (3 and 4 in FIG. 1). This signal is shown in FIG.

As shown in Figure 6 (B), the 720° signal rises simultaneously with the reference signal shown in Figure 6 (A) at a predetermined crank angle (approximately 70 degrees before the compression top dead center of the first cylinder). This is a pulse signal, which executes the 720' synchronized program shown in FIG. 5(a).

That is, the contents of the N counter are cleared to O (step 110).

As shown in Figure 6 (a), the reference signal rises every 180' in the case of a four-cylinder engine, which is a predetermined crank angle (approximately 70°) before compression top dead center of each cylinder. When the reference signal is input, the reference signal synchronization program shown in FIG.
Clear the contents of the counter and set it to 0.

The 1" signal is the 1" signal of the crankshaft as shown in Figure 6 (C).
``This is a pulse signal that repeats rising and falling every rotation, and each time a 1° program shown in FIG. 5 (c) is executed.

Note that the 720° synchronization program is performed with priority over the reference signal synchronization program, and the reference signal synchronization program is
°It takes priority over the signal synchronization program.

Further, FIG. 6(d) shows changes in the count value of the PoS counter, and FIG. 6(e) shows the rotation angle of the crankshaft.

Next, a 1° synchronization program will be explained.

First, in step 113, a POS counter indicating the crank angle position is incremented by one. next.

In step 114, the contents of the POS counter (count value)
Immediately after the program based on the reference signal is executed, that is, when the POS counter = 1, step 11 is executed.
The process branches to step 5, and otherwise executes step 117.

In step 115, depending on the value of the N counter.

Next, the cylinder number where the compression top dead center is located is stored in the NCYL register. (For example, when the value of the N counter is 0, 1, 1
3 when , 4 when 2, 2 when 3 is stored as the cylinder number).

Next, in step 116, FLAG, which determines whether or not to perform A/D conversion, is set to 0 (A/D conversion is performed), and the A/D conversion is performed.
The C counter for detecting the number of conversions and the crank angle from the rise of the reference signal is cleared, and the process proceeds to step 118.

If the process proceeds to step 117 in step 114, A/
Determine whether FLAG for determining whether to perform D conversion is 0 or 1, and if it is O (conduct A/D conversion), step 11
Proceed to 8, and if it is 1 (no A/D conversion), use this 1
End the ° synchronization program and wait for the execution of the primary l ° synchronization program.

In step 118, the channel of the A/D converter to which the signal of the cylinder pressure sensor 2 (FIG. 2) of each cylinder is input is selected based on the cylinder number at the compression top dead center stored in the NCYL register, and Start D conversion.

Next, in step 119, it is determined whether the A/D conversion has ended, and if it has ended, in step 120, the A/D value is stored in the register at the address corresponding to the value of the C counter.

Then, in step 121, the value of the C counter is determined and 1
If it is less than 00 (i.e. 29" ATDC), proceed to step 122; if it is greater than 100, proceed to step 1.
Proceed to step 23.

That is, until 29'' ATDC, the contents of the C counter are incremented by one in step 122, and the execution of the primary l° synchronization program is waited.

When the A/D conversion store of 30° ATDC is completed.

Jump to step 123, C counter = 0°FLA
G=1, Pn+axi= Or θpn+axi=
Next, in step 124, the value of Pmaxi is compared with the data in the register corresponding to the value of the C counter, and it is determined whether they are equal or not.
If maxi is larger, the process jumps to step 127, and if prmaxi is smaller, the process proceeds to step 125, where data in the register corresponding to the value of the C counter is stored in Pax4. Then, in step 126 θ
Let pmaxi=C counter.

Next, in step 127, the value of the C counter is determined and 10
If it is less than 0, proceed to step 128 and set the C counter to 1.
After one increment, the process returns to step 124 and P
maxi, θpmaxi is determined, and when the C counter = 100, the process proceeds to step 129, and θpmaxi is determined.
Subtract 70° (crank angle from the rise of the reference signal to top dead center) from pmaxi, terminate the execution of this program, and wait for the execution of the next 1° synchronization program.

Pmaxi and θpmaxi at this point are the maximum values P of the cylinder pressures of the cylinders that are at compression top dead center at that time.
IIlax and cylinder pressure maximum crank angle position θ
pmax.

In subsequent 1'' synchronization programs, FLAG=1, so A/D conversion is not performed until the next reference signal synchronization program is executed.

As described above, P wax 1 to pmax of each cylinder
4 and θpWaX1~θpmEIX4 can be determined.

FIG. 7 shows an example in which this embodiment is constructed using hardware.

Reference numeral 101 denotes a POS counter, which resets the counter value when the reference signal rises and increases the count value by one each time the 1° signal rises or falls.

Reference numeral 102 denotes an N counter, which increments a count value by one each time a rising edge of the reference signal is input, and clears the count value to 0 when a rising edge of the 720° signal is input.

103 is a multiplexer which inputs signals from the cylinder pressure sensors 2 (FIG. 2) for each cylinder.

The output signal is switched according to the count value of the N counter 102. That is, the count value of the N counter 102 is 0.
When , the signal for the 1st cylinder is output, when 1, the signal for the 3rd cylinder, when 2, the 4th cylinder, and when 3, the 2nd cylinder signal is output.

A C counter 104 is reset to 0 each time the output of the N counter 102 changes, and counts up by one each time the 1@ signal rises or falls.

105 is an A/D converter which A/D converts the output signal of the multiplexer 103 every time the value of the C counter 104 changes.

A memory 106 stores P ysax and θprmax. The stored P ysax value is cleared every time the output of the N counter 102 changes, and when the P ysax value is rewritten, the count value of the C counter 104 at that time is stored in the θρ■aK memory section.

A comparator 107 compares the A/D converted value by the A/D converter 105 with the Pax value stored in the memory 106, and converts the Pvsax value to A/D only when the A/D converted value>Pvsax value. Rewrite to D conversion value. At this time, the θpmax value also becomes the count value of the C counter at that time.

Reference numeral 108 is a memory for storing θpHlaX of each cylinder, and the stored value is rewritten when the value of the N counter 102 changes.The location where the number minus 70 from the θpmax value before clearing is stored is .

The value before the change of each N counter is When 0, θpHaX 1 When 1, θpHaX 3 2 epmaX4 When 3, θpHaX2 It is.

In this way, θρ1IaX 1~θpma of each cylinder
Find x4.

〔Effect of the invention〕

As explained above, the internal combustion engine control device according to the present invention interrupts the ignition timing correction control based on θpmax during the transient period after the load change of one engine exceeds a predetermined value, so that θpn+ax becomes the target value. The air-fuel ratio was corrected and controlled to match the value.

Since fluctuations in the air-fuel ratio during the transient period can be reduced, torque fluctuations can be reduced and drivability can be improved. Furthermore, by stabilizing the air-fuel ratio, it is possible to suppress the occurrence of knocking during transient periods.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing the basic configuration of the present invention. FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention. Fig. 3 is a flowchart of the air-fuel ratio correction routine when this invention is realized in software using a microcomputer, Fig. 4 is a flowchart of the ignition timing correction routine, and Fig. 5 is the step of Fig. 3. θpiI in subroutine 1
Flowchart showing an example of a program for detecting ax; FIG. 6 is a timing diagram showing the relationship between each timing signal, crank angle, and count value of a PoS counter for executing the program of FIG. 5; FIG. 7 is a block diagram showing an example of a hardware configuration of the θρmax detector that operates as shown in FIG. 5. FIG. 8 is a block diagram showing an example of the configuration of a conventional internal combustion engine control device. 1 is a diagram showing an example of a three-dimensional table of advance angle of ignition timing with respect to engine rotational speed N and basic injection amount To. FIG. 10 is a diagram showing an example of variations in throttle valve opening, intake air amount, air-fuel ratio, and θpmaλ during a transient period. 1... θpNaX detector 2... Cylinder internal pressure sensor 5... Target value setter 6... Comparator 9.
...Load detector 10...Corrector (for ignition timing correction)
11...Ignition circuit 12...Basic injection amount calculator (also serves as load state detection means) 13...Transient period determiner 14...Switcher (correction switching means) 15...Corrector (empty (For fuel ratio correction) 16...Fuel valve drive circuit Figure 4 (A) (C)
Figure 5))

Claims (1)

[Claims] 1. The crank angular position (θpmax) at which the cylinder pressure is at its maximum is detected for each combustion cycle of the internal combustion engine, and the crank angular position (θpmax) is set to a predetermined target value (θ
A control device for an internal combustion engine is provided with a means for correcting and controlling the ignition timing so that the two coincide with each other, and a load state detecting means for detecting the load state of the engine; a transient period determining means for determining a transient period when a change in load exceeds a predetermined value; an air-fuel ratio correcting means for correcting and controlling an air-fuel ratio of the air-fuel mixture supplied into the cylinder; Therefore, during the transition period, the ignition timing correction control is interrupted, and the air-fuel ratio correction means adjusts the crank angle position (θ
1. A control device for an internal combustion engine, comprising: correction switching means for correcting and controlling an air-fuel ratio so that a detected value of pmax) matches a target value (θpmaxo). 2. A patent claim in which the transient period determining means is a means for determining a period during which the change in load detected by the load state detecting means is equal to or greater than a predetermined value and a predetermined period after the end of that period as a transient period. A control device for an internal combustion engine according to item 1.