JPH0315016B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of controlling an air control valve installed in an automobile engine, which is provided mainly to adjust the engine rotational speed during idling.

[Conventional technology]

Conventionally, when the engine is idling, an air control valve installed in the intake pipe is controlled so that the actual rotation speed converges to a desired target rotation speed, and a predetermined amount of intake air is supplied to the engine. Methods for controlling the amount of intake air are generally known. (For example, Japanese Unexamined Patent Application Publication No. 54-74723) [Problems to be Solved by the Invention] By the way, in the conventional control method shown in the above-mentioned publication, the air control valve is controlled at a control value according to the warm-up state of the engine at the time of starting. was under control.

However, since this control value is determined according to the engine and air control valve at the time of design, changes in the engine and air control valve over time (for example, if dust accumulates on the valve part of the air control valve, the opening area may change). As a result, the relationship between the control value and the opening area of the air control valve, that is, the amount of intake air, deviates from the desired characteristics at the time of design. As a result, sufficient intake air volume cannot be obtained during startup or non-idling operation without negative feedback control as described above, resulting in poor starting performance and rotational speed during the transition from non-idling to idling. This results in deterioration of drivability such as stability.

SUMMARY OF THE INVENTION Therefore, in view of the above problems, it is an object of the present invention to provide a method for controlling the intake air amount of an engine that can maintain the desired drivability at the time of design.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an engine intake air amount control method that controls an air control means that adjusts the amount of air taken into the engine according to the operating state of the engine, the method comprising: a first control value that is determined by comparing the engine rotation speed and the target rotation speed in order to cause the engine rotation speed to converge to a desired target rotation speed at an idle time when the throttle valve is closed; , the air control means is controlled by a control amount including a second control value determined according to a warm-up state of the engine, and the stored content of the correction value determined by the first control value is retained even after the engine is stopped. controlling the air control means with a control amount corrected by the second control value by the correction value when the engine is starting and when the engine is not idling when the throttle valve is open; This is a method for controlling the intake air amount of an engine, which is characterized by the following.

〔Example〕

The present invention will be described below with reference to embodiments shown in the drawings. In FIG. 1, an engine 10 is a known four-cycle spark ignition engine for automobiles, and is equipped with a vehicle air conditioner and an automatic transmission as engine loads. This engine 10 takes in air through an air cleaner 11, an air flow meter 12, an intake pipe 13, a surge tank 14, and each intake branch pipe 15, and fuel, such as gasoline, is injected through an electromagnetic fuel injection valve 16 provided in each intake branch pipe 15. It is supplied by injection from.

The main intake air amount of the engine 10 is regulated by a throttle valve 17 which is arbitrarily operated, while the fuel injection amount is regulated by an electronic control unit 20. The electronic control unit 20 uses the engine rotational speed measured by the rotational speed sensor 18 built in the distributor of the ignition device and the intake air amount measured by the airflow meter 12 as basic parameters to control the fuel consumption. The injection amount is determined by a known method, and the fuel injection amount is also increased or decreased in a known manner based on signals from a warm-up sensor 19 using a water temperature sensor that detects the cooling water temperature.

The air conduits 21, 22 are provided so as to bypass the throttle valve 17, and an air control valve 30 is provided between the two conduits 21, 22. Further, one end of the conduit 21 is connected to an air inlet 23 provided between the throttle valve 17 and the air flow meter 12, and one end of the conduit 22 is connected to an air outlet 24 provided downstream of the throttle valve 17. It is connected.

The air control valve 30 is basically a proportional electromagnetic (linear solenoid) type control valve, and the housing 3
1 changes the air passage area between the air conduits 21, 22. Usually the plunger 32 is a compression coil spring 33
The air passage area is set to zero.

By energizing the electromagnetic mechanism 34, an electromagnetic attractive force acts between the plunger 32 and the core 35, and the plunger 32 attracts the core 3 depending on the average value of the energized current.
Approaching 5.

In this way, the air control valve 30 is operated by the electromagnetic mechanism 3.
Plunger 32 and core 3 depending on the current flowing through 4.
5 and the air passage area between the air conduits 21 and 22 can be changed continuously, so the air flow rate can be controlled by the current value.

The electromagnetic mechanism 34, like the fuel injection valve 16, is driven and controlled by the electronic control unit 20. The electronic control unit 20 includes the rotational speed sensor 18 described above.
In addition to the warm-up sensor 19, various signals are input, including a signal from an air conditioning switch 28 that turns on and off an electromagnetic clutch 27 that connects and disconnects a compressor 26 for an air conditioner such as an automobile cooler and an engine drive shaft. be done.

Next, this electronic control unit 20 will be explained with reference to FIG. Reference numeral 100 denotes a microcomputer that calculates the amount of fuel injection and the amount of air for speed correction using the opening time width of the fuel injection valve 16 and the displacement amount of the electromagnetic mechanism 34 of the air control valve 30 (that is, the magnitude of the average supplied current). It is a processor (CPU). 1
01 is a rotational speed counter that detects the engine rotational speed based on a signal from the rotational speed (rotational speed) sensor 18. Further, this rotation number counter 101 sends an interrupt command signal to the interrupt control section 102 in synchronization with the engine rotation. Upon receiving this command signal, the interrupt control unit 102 supplies an interrupt signal to the microprocessor 100 via the common bus 150,
The microprocessor 100 calculates the amount of fuel to be injected using a known method. 103 is a digital input port which, in addition to the signal from the air conditioning switch 28, also receives a signal from a starter switch 41 that turns on and off the operation of a starter (not shown), and a neutral switch 42 that detects whether the automatic transmission of the automobile is in the neutral position. , a signal from the throttle switch 43 that detects whether the throttle valve 17 is fully closed (i.e., in the idle position), and a vehicle speed detector that detects whether or not the vehicle has a vehicle speed (i.e., whether it is stopped or not). 44 signals are input and these digital signals are supplied to the microprocessor 100. 104 is an analog multiplexer and A-
An analog input port consisting of a D converter converts the signal from the warm-up sensor 19, which detects the cooling water temperature, and the signal from the air flow meter 12, which detects the amount of intake air into the engine, and sequentially outputs the microprogram. It is supplied to the setter 100. Each of these units 1
The upper outputs of 01, 102, 103, and 104 are connected to the microprocessor 100 through the common bus 150.
is transmitted to. 50 is a battery, 51 is a key switch, and the power supply circuit 105 is connected to the key switch 51.
It is directly connected to the battery 50 without passing through it, and supplies current to the nonvolatile memory (RAM) 107. Therefore, power is always applied to the RAM 107 regardless of the key switch 51. 106 is also a power supply circuit, which is connected to the battery 50 through the key switch 51. The power supply circuit 106
Supply power to parts other than RAM107. The non-volatile memory (RAM) 107 serves as a temporary storage unit that is used temporarily during program operation, but as mentioned above, power is always applied regardless of the key switch 51, and the engine operation can be stopped by turning the key switch 51 OFF. It is structured so that the memory contents will not be lost even if the memory is used. Correction values R (R ₁ , R ₂ , R ₃ ,
R ₄ ) is stored in this RAM 107. 10
Reference numeral 8 denotes a memory unit consisting of a read-only memory (ROM) for storing programs and various constants, and a read/write memory for temporarily storing data during program operation (during arithmetic processing). 109
is a fuel injection time control counter including a register, consisting of a down counter, and operated by a microprocessor (CPU) 100.
The digital signal representing the valve opening time of the electromagnetic fuel injection valve 16, that is, the fuel injection amount, is converted into a pulse signal having a pulse time width that gives the actual valve opening time of the electromagnetic fuel injection valve 16. 11
0 is an amplifier circuit that drives the electromagnetic fuel injection valve. Reference numeral 111 denotes a D-A conversion unit used to control the amount of air for correcting the rotation speed, and an electromagnetic mechanism 34 that determines the amount of air for correction calculated by the microprocessor 100, that is, the opening degree of the electromagnetic air control valve 30.
A control amount I signal representing the magnitude of the current supplied to the air conditioner is converted into an analog value, and this analog signal is amplified by a known drive circuit 112 to drive the air control valve 30. 113 measures the elapsed time with a timer.
It is transmitted to the CPU 100. Rotation number counter 101
measures the engine rotational speed once per engine rotation based on the output of the rotational speed sensor 18, and supplies an interrupt command signal to the interrupt control unit 102 when the measurement is completed. The interrupt control unit 102 generates an interrupt signal from the signal and sends it to the microprocessor 1.
00 to execute an interrupt processing routine for calculating the fuel injection amount.

FIG. 3 shows a schematic flowchart of the part of the microprocessor 100 that calculates the amount of air for rotational speed correction.Based on this flowchart, the functions of the microprocessor 100 and the operation of the entire configuration will be explained. do.

Key switch 51 and starter switch 41
is turned on and the engine is started, the main routine calculation process starts at the start of the first step 1000, and the CPU 10 starts at step 1001.
Initial conditions such as a start address setting of 0 are set, and in step 1002 a digital value corresponding to the cooling water temperature signal from the warm-up sensor 19 obtained via the analog input port 104 is read. In step 1003, the non-volatile memory 107
It is determined whether the correction values R (R ₁ , R ₂ , R ₃ , R ₄ ) stored in the memory are normal, that is, whether the correction values R are within a predetermined range. Proceeding to step 1004, each value R ₁ to _{R 4} of the correction value R in the nonvolatile memory 107 is rewritten to a preset initial correction value (fixed value) I (I ₁ , I ₂ , I ₃ , I ₄ ). When the correction value R is normal or when the rewriting in step 1004 is completed, step 1005
Then, it is determined whether the starter of the engine is being driven, that is, whether the starter switch 41 is on using the signal from the starter switch 41. When the starter is being driven, the engine is started according to the warm-up condition at that time from the starting map 1 shown in FIG. Find the basic control value Is for the current time, and use this basic control value Is as the current control value I'. Next, steps 1028, 1029,
In step 1030, it is determined whether the air conditioning switch is on or not and whether the automatic transmission is in the neutral position to determine the engine load. If the air conditioning switch is off and the transmission is in the neutral position in the first engine load state, step 1031 is performed. In step 1035, the corrected value _R1 corresponding to the first condition is read from the non-volatile memory 107 to calculate the output control amount I=I'+ _R1 , which is output to the DA conversion unit 111 in step 1035. In addition, when the air conditioning switch is off and the transmission is in a non-neutral position and in the second engine load state, the process proceeds to step 1032 and the correction value corresponding to the second condition is set.
The output control amount I=I'+ _R2 is calculated and output using _R2 , and when the air conditioning switch is on and the transmission is in the neutral position in the third engine load state, the process advances to step 1033 and the third condition is met. Calculate and output the output control amount I=I'+ _R3 using the correction value _R3 ,
Step 1 when the air conditioning switch is on and the transmission is in a non-neutral position, in the fourth engine load condition.
The process proceeds to step 103, where the output control amount I=I'+ _R4 is calculated using the modified value _R4 corresponding to the fourth condition.
Output by 5.

If the starter is off in step 1005, the process advances to step 1007, where the control value I' determined in the previous main process is retrieved from the post-start warm-up map 2 (<starting map 1) shown in FIG. It is determined whether _the basic control value after starting I ₀ determined according to the warm-up state of
The transient correction amount I _H is read from 108 and subtracted from the control value I', and the current control value I' is set as the sequential control value.
Reduce I′.

The control value thus obtained in step 1009
I' is a modified value R according to the load condition, similar to the control value obtained in step 1008 when the starter is ON.
is added to become the output control amount I. That is, in steps 1028 to 1034, a correction value R (R ₁ , R ₂ , R ₃ , R ₄ ) corresponding to the engine load condition is added, and in step 1035, the corrected output control amount I is changed to D-
It is output to the A conversion unit 111.

In addition, the previous control value is determined in step 1007.
If I' becomes less than or equal to the basic control value I ₀ after starting, in step 1010, the basic control value I ₀ based on warm-up map 2 is set as the control value I'.

In steps 1012 to 1016, it is determined whether the engine is in a stable state after warming up. That is, the process proceeds to step 1012, where it is determined whether the engine warm-up operation has been completed, that is, whether the coolant temperature has exceeded a predetermined temperature using information on the coolant temperature from the warm-up sensor 19. When the warm-up operation is completed, the process proceeds to step 1013, where it is determined whether the throttle valve is fully closed, that is, whether the throttle valve is at the idle position using the signal from the throttle switch 43. If the throttle valve is fully closed, proceed to step 1014;
The vehicle speed detector 44 determines whether or not there is a vehicle speed.
The system determines whether the car is stopped or moving using the signals. When the automobile is stopped, the process proceeds to step 1015, and the engine rotation speed is determined using the signal of the engine rotation speed (revolution number) Ne, which is the output of the rotation number counter 101, to determine whether the engine rotation has stopped or is stopped.
Determine whether Ne is greater than or equal to a certain value. If the engine rotation has not stopped, the process proceeds to step 1016 to check whether the fluctuation in the engine rotation speed is less than a predetermined value, that is, the rotation speed Ne is used to compare the current rotation speed with the rotation speed before the predetermined cycle or before the predetermined period. It is determined whether the difference is less than or equal to a predetermined value. When the engine speed fluctuation is small, that is, when all the judgment conditions in steps 1012 to 1016 are satisfied, and when the engine can be considered to be in an idling operating state and in a stable state, step 101 is performed.
Step 7 determines whether the air conditioning switch 28 is on, that is, whether the compressor 26 for the air conditioner is connected as an engine load, and then proceeds to step 1.
At 018 and 1019, the signal from the neutral switch 42 of the automatic transmission of the automobile is used to determine whether the transmission is in the neutral position, that is, whether or not it is connected as an engine load. When the air conditioning switch 28 is off and the transmission is in the neutral position, that is, under the first condition where it is not acting as a load, the process advances to step 1020 and the correction value R is determined.
The corrected value _R1 corresponding to this first condition is corrected by negative feedback control and stored. In other words, the correction value R ₁ is controlled by learning.

The learning control of this correction value _R1 will be explained with reference to the flowchart in _FIG . In step 603, the actual rotation speed Ne is read.
Calculation of the difference ΔN between and the target speed N ₁ , that is, ΔN=Ne−
N ₁ is calculated, and in step 604 it is determined whether this ΔN is positive. If ΔN is positive, step 605 is performed.
Since the actual rotational speed Ne is faster than the target speed _N1 , the correction value _R1 is subtracted by a predetermined correction amount ΔI in order to lower the actual rotational speed, that is, to reduce the amount of air for rotational speed correction, and _R1 = Store R ₁ −ΔI in non-volatile memory 107 as a new modified value R ₁ .
If ΔN is not positive, it is determined in step 606 whether ΔN is negative or not, and if it is negative, the process proceeds to step 607, where a correction value R ₁ =R ₁ +ΔI is calculated by the logic opposite to that of step 605, and this new correction is performed. value R ₁
is stored in the non-volatile primary memory 107. Step 6
If it is determined in step 06 that ΔN is not negative, R ₁ is not rewritten. The details of the processing step 1020 for learning control of the correction value _R1 have been described above. After the processing in step 1020, the process proceeds to step 1024 and uses the new correction value _R1 to calculate the output control amount I=I′+
Calculate R ₁ (=I ₀ + R ₁ ) and in step 1035 D-
It is output to the A conversion unit 111.

If it is determined in steps 1017, 1018, and 1019 that the air conditioning switch 28 is off and the automatic transmission is not in the neutral position but in the drive position, the load condition is the second condition, the process advances to step 1021 and this first of the correction values R is determined. A correction value R ₂ corresponding to the two conditions is corrected and calculated by negative feedback control and stored.
The correction process for the correction value R ₂ in step 1021 is performed in the same manner as in step 1020 above, and the difference between the idle target rotation speed N ₂ preset corresponding to the second condition of the engine load and the actual idle rotation speed Ne is From this, calculate and correct R ₂ = R ₁ ±ΔI. Next, proceeding to step 1025, the output control amount I=I'+ _R2 is determined and output using the new correction value _R2 .

If it is determined in steps 1017, 1018, and 1019 that the load condition is the third condition, in which the air conditioning switch 28 is on and the automatic transmission is in the neutral position, the process advances to step 1022 and the correction value R is determined.
Of these, the corrected value _R3 corresponding to this third condition is corrected by negative feedback control and stored. The correction process in step 1022 is also the same as that in step 102.
0,1021, R ₃ = R ₃ ± from the difference between the target idle rotation speed N ₃ and the actual idle rotation speed Ne corresponding to the engine load and this third condition.
Calculate and correct ΔI. Next step 10
The process proceeds to step 26, where the output control amount I=I'+ _R3 is determined and output using the new correction value _R3 .

In the judgments in steps 1017, 1018, and 1019, if it is judged that the load condition is the fourth condition in which the air conditioning switch 28 is on and the automatic transmission is in the neutral position, the process advances to step 1023 and the correction value R is determined.
Of these, the correction value _R4 corresponding to this third condition is corrected by negative feedback control and stored. Similar to steps 1020, 1021, and 1022, the process for correcting the correction value _R4 in step 1023 is performed by adjusting the idle target rotation speed _N4 , which has been set in advance in response to the fourth condition of the engine load, and the actual idle rotation speed Ne. Calculate and correct R ₄ = R ₄ ±ΔI from the difference. Next, proceeding to step 1027, the output control amount I=I'+ _R4 is determined and output using this new modified value _R4 . In this embodiment, the target rotational speed _N4 corresponding to the fourth condition is selected to be the same value as the target rotational speed _N2 set corresponding to the second condition. In addition, the correction values R ₁ , R ₂ , R ₃ , R ₄ and the initial correction values I ₁ , I ₂ ,
I ₃ and I ₄ are steps 1020, 1021, respectively.
The correction value R ₁ explained in the processing of 1022 and 1023,
This corresponds to R ₂ , R ₃ , and R ₄ .

Steps 1012, 1013, 1014, 10
15, 1016, when the engine is warming up, when the throttle valve is open, when the car is running (vehicle speed is high), when the engine is stopped, when the engine rotational fluctuation is large. If it is determined that either of the above is the case, that is, the engine is not in a stable state or in an idling state, the process proceeds to step 1028 to correct the correction value R (R ₁ , R ₂ , R ₃ , R ₄ ). will not be carried out. Steps 1028, 1029, 103
At 0, the same processing as the correction at startup in step 1008 and during transition in step 1009 described above is performed. That is, these steps 1031, 103
In the processes of No. 2, 1033, and 1034, the output control amount I that determines the rotational speed, that is, the amount of air for rotational speed correction is determined by the basic control value I ₀ (5th It is given by the warm-up map 2) in the figure and the correction values R (R ₁ , R ₂ , R ₃ , R ₄ ) learned and controlled in steps 1020 to 1023, and therefore the actual rotation speed Ne
Negative feedback control such as checking whether there is a deviation from the target rotational speed will not be performed.

Steps 1008, 1009, 1024, 10
25, 1026, 1027, 1031, 103
When any one of the processes 2, 1033, and 1034 is completed and the output control amount I is output in step 1035, the process returns to step 1002 and the above-described process is repeated.

On the other hand, the routine for calculating the fuel injection amount (that is, the injection time width) from the fuel injection valve 16 is well known and will not be described in detail, but it includes the amount of rotational speed correction air supplied via the air control valve 30 to the engine. The total intake air amount to the engine is detected by the air flow meter 12, and each time an interrupt command is issued by the interrupt control unit 102 based on this intake air amount signal, the CPU 100 calculates the fuel injection amount and uses the calculation result to control the fuel injection time. output to counter 109. Thus, the fuel injection valve 16 injects and supplies fuel in an amount commensurate with the amount of intake air.

Although the above embodiment describes an engine having a fuel injection device, in the case of an engine with a carburetor, an actuator for controlling the opening of the throttle valve is provided in place of the air control valve 30, and the operation of this actuator is controlled as described above. Similarly, it is also possible to control according to the output control amount I.

As described above, according to the above embodiment, when starting the engine, the starting map 1 is used, and from this starting map 1, the control value according to the warm-up state is determined.
The air control valve 30 is controlled using this control value and the correction value stored by learning control. On the other hand, after starting the engine, a warm-up map 2 for use after starting is used, and from this warm-up map 2, the air control valve 30 is controlled according to the warm-up state. The air control valve 30 is controlled by the control value and the correction value stored by the learning control.
In addition, starting map 1 is set to obtain a larger control value than warm-up map 2 even in the same warm-up state, so a sufficiently large amount of air-fuel mixture is supplied to the engine at startup, which is sufficient for large friction torque. Overcome and start. In other words, good starting performance can be obtained, and after starting, a mixture suitable for the warm-up characteristics after starting can be supplied to the engine with a smaller control value than during starting, so the rotational speed after starting can be reduced. This prevents the rotation speed from becoming too high and allows the rotation speed to be adjusted to a suitable value.

Therefore, it becomes possible to achieve both good starting performance and good drivability during the warm-up process, and it becomes possible to reduce unnecessary engine operation, thereby improving fuel efficiency.

In addition, in this embodiment, when switching from starting map 1 to warm-up map 2 after starting, the control value determined by starting map 1 at the time of completion of starting is changed to the warm-up map at predetermined intervals or every predetermined rotation of the engine. The control value is subtracted by a predetermined amount so as to be closer to map 2, and warm-up map 2 is used from when the control value obtained by subtracting becomes smaller than the control value determined by warm-up map 2. Therefore, the control value does not change suddenly immediately after the start is completed, and therefore, when switching between two types of maps, there has never been a sudden change in the control value, so there is no chance of a sudden change in rotation when switching. There is no.

Furthermore, according to this embodiment, a correction value obtained by performing negative feedback control based on a desired target rotation speed and an actual engine rotation speed during stable idling is stored in the nonvolatile memory, and this correction value is also stored in the nonvolatile memory. Since this is reflected in the entire operating range including the time of starting, the intake air amount characteristics obtained by the control values from starting map 1 and warm-up map 2 may change from the desired state at the time of design due to changes over time. Even if the above correction value changes over time, the above-mentioned correction value will absorb the deviation due to changes over time, and therefore the desired intake air volume characteristics at the time of design will always be obtained.
Drivability can always be maintained at a good level, and especially when starting, it is possible to maintain the desired startability at the time of design, and when transitioning from non-idling to idling after startup, the desired startability at the time of design can be maintained. The actual rotation speed will smoothly settle down to the target rotation speed with responsiveness.

〔Effect of the invention〕

As described above, according to the present invention, even if the intake air amount characteristic with respect to the second control value determined according to the warm-up state changes from the desired one at the time of design due to changes in the air control means etc. over time, , a second control that is used at the time of starting and when the negative feedback control is not executed, and when the engine is not idling, based on a correction value that is obtained when the negative feedback control is executed and is stored in a storage means that can retain the memory contents even after the engine is stopped. Since the air control means is controlled by the control amount obtained by correcting the value, the deviation from the desired characteristic at the time of design is absorbed by this corrected value, and therefore the desired intake air amount characteristic is maintained. This has the excellent effect of making it possible to always maintain the desired starting performance when starting, and when transitioning from non-idling to idling, the aging of the air control means during non-idling Since the desired amount of intake air is secured without being affected by changes, the actual rotation speed smoothly changes to the target rotation speed and is always stabilized with the same response as the desired response at the time of design. There is also the excellent effect that the desired drivability at the time of design can be maintained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an engine and its peripheral equipment to which an embodiment of the present invention is applied, and FIG. 2 is a block diagram of the electronic control unit shown in FIG. 1.
3 is a flowchart showing the main functions of the microprocessor shown in FIG. 2, FIG. 4 is a detailed flowchart of the main part of the flowchart in FIG. 3, and FIG. 5 is a flowchart showing the main functions of the microprocessor shown in FIG. FIG. 2 is a characteristic diagram for explaining the embodiment shown in FIG. 10...engine, 18...rotational speed sensor,
20...Electronic control unit, 100...Microprocessor (CPU), 107...Nonvolatile memory, 30...Air control valve.

Claims (1)

[Scope of Claims] 1. A method for controlling the amount of intake air for an engine, which controls an air control means for adjusting the amount of air taken into the engine according to the operating state of the engine, the method comprising: a first control value determined by comparing the engine rotation speed and the target rotation speed in order to converge the engine rotation speed to a desired target rotation speed during idle time when the throttle valve is closed; and a first control value determined by comparing the engine rotation speed with the target rotation speed; The air control means is controlled by a control amount including a second control value determined according to the state, and the correction value determined by the first control value is stored in a storage means that can retain the stored contents even after the engine is stopped. and controlling the air control means with a control amount obtained by modifying the second control value by the correction value when the engine is starting and when the engine is not idling when the throttle valve is open. Features: Engine intake air amount control method. 2. The engine intake air amount control method according to claim 1, wherein the first control value is stored in the storage means as the correction value. 3 The second control value has two values: one for starting and one for after starting, and the one for starting that is used when starting is used during non-idling or idling after starting. 3. The intake air amount control method for an engine according to claim 1, wherein the intake air amount is set to a value that allows a larger amount of intake air to be obtained than that for after startup.