JPH0835440A - Output torque control device and control method for internal combustion engine - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide an output torque control device and a control method for an internal combustion engine in consideration of changes over time. [Structure] Torque detection means for detecting output torque 1, lean combustion limit determination means for determining the limit of lean combustion 2, air-fuel ratio correction means for correcting air-fuel ratio 3, limit air-fuel ratio of NOx emission amount according to air-fuel ratio NOx emission limit air-fuel ratio determining means 5, target air-fuel ratio data changing means 6 for changing target air-fuel ratio data, target air-fuel ratio data storage means 7 for storing target air-fuel ratio data, and target air-fuel ratio data It is composed of a fuel amount calculation means 8 for calculating the fuel amount using the air-fuel ratio correction value and a fuel injection device 9. [Effect] Since lean burn control can be realized in accordance with the driver's request in consideration of changes over time, deterioration of fuel efficiency, exhaust gas harmful substance reduction performance, and drivability can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output torque control device and control method for an internal combustion engine of an automobile, and more particularly to an output torque control device and control method for a lean burn internal combustion engine.

[0002]

2. Description of the Related Art In a conventional lean burn internal combustion engine control method, for example, as disclosed in Japanese Patent Laid-Open No. 51-34329, the air-fuel ratio is controlled in accordance with the periodic fluctuation of the average pressure of the combustion chamber, Methods have been proposed for increasing the lean operating range and improving fuel economy. Further, as described in JP-A-58-160530, there has been proposed a method of controlling the EGR (exhaust gas recirculation) amount, the ignition timing and the air-fuel ratio according to the torque fluctuation obtained from the combustion pressure and the like. .

[0003]

However, in the air-fuel ratio control for increasing the lean operation range for the purpose of improving fuel economy, the exhaust gas harmful component reduction performance, that is, the emission amount of nitrogen oxide components (hereinafter, referred to as NOx) is reduced. Is not considered, and it is not perfect for the control of a lean-burn internal combustion engine. Furthermore, fuel consumption, exhaust gas harmful component reduction performance, and drivability may deteriorate as compared with the initial state due to changes over time in the components of the lean-burn internal combustion engine and the components of the control device. The control is not perfect.

An object of the present invention is to consider the above-mentioned change with time,
An object of the present invention is to provide a control apparatus and a control method for a lean-burn internal combustion engine that does not deteriorate fuel economy, exhaust gas harmful component reduction performance, and drivability.

[0005]

In order to achieve the above object, the present invention provides a torque detecting means for detecting an output torque indicating an operating state of a lean burn internal combustion engine, and a lean burn limit according to a change in the output torque. Lean combustion limit determination means for determining a region, air-fuel ratio detection means for detecting an air-fuel ratio of a lean-burn internal combustion engine, and a limit air-fuel ratio corresponding to a predetermined limit value of NOx emission amount is determined using this air-fuel ratio NOx emission limit air-fuel ratio determination means, air-fuel ratio correction means for correcting the air-fuel ratio corresponding to the lean combustion limit determined by the lean combustion limit determination means, the air-fuel ratio correction means, and the NOx emission limit air-fuel ratio determination Target air-fuel ratio data changing means for rewriting and changing the target air-fuel ratio data according to the air-fuel ratio correction value from the means, and storing the target air-fuel ratio data used for the fuel amount calculation. Target air-fuel ratio data storage means, fuel amount calculation means for calculating the fuel amount using the target air-fuel ratio data and the air-fuel ratio correction value, and the fuel amount calculated by the fuel amount calculation means in a lean-burn internal combustion engine It is composed of a fuel injection valve for supplying.

[0006]

With the above structure, the limit NOx emission amount is determined by using the air-fuel ratio obtained from the air-fuel ratio detection means, and when the lean combustion operation becomes difficult from the viewpoint of the NOx emission amount, the air-fuel ratio is changed to the theoretical mixture. The exhaust performance is maintained by controlling (air-fuel ratio = 14.7). Further, by adding torque correction by air amount control to air-fuel ratio control that achieves both fuel efficiency improvement by lean combustion limit control and exhaust performance maintenance by NOx emission amount limit determination, change in output torque of the internal combustion engine can be prevented and torque fluctuation can be prevented. Can be suppressed.

[0007]

The present invention will be described below with reference to the drawings.

FIG. 1 is an embodiment of the present invention and is a block diagram showing control of output torque according to the present invention. In FIG. 1, a torque detection means for detecting a torque indicating an operating state of a lean burn internal combustion engine, a lean burn limit determination means for determining a lean burn limit while detecting a change in the torque, and an air-fuel ratio at a burn limit determination. Air-fuel ratio correction means 3, air-fuel ratio detection means for detecting the air-fuel ratio of the lean-burn internal combustion engine 4, NOx emission limit air-fuel ratio determination means 5 for determining the NOx emission limit air-fuel ratio according to this air-fuel ratio , Target air-fuel ratio data changing means for rewriting and changing the target air-fuel ratio data according to the air-fuel ratio correcting means and the NOx emission limit air-fuel ratio discriminating means 6, a target air-fuel ratio data used for fuel quantity calculation The present invention is constituted by the fuel ratio data storage means 7, the fuel amount calculation means 8 for calculating the fuel amount using the target air-fuel ratio data and the air-fuel ratio correction value, and the fuel injection device 9. That is, the NOx emission limit air-fuel ratio discriminating means 5 compares the actual lean combustion limit air-fuel ratio with the NOx emission limit air-fuel ratio, and based on this discrimination, the target air-fuel ratio is set and the air-fuel ratio control corresponding to the change over time is performed. To achieve both fuel efficiency and exhaust.

FIG. 2 is a specific control block diagram of the present invention. Here, an example in which an existing sensor is used is shown in terms of cost, wearability, and the like. The torque fluctuation near the lean burn limit is detected by detecting the internal combustion engine rotational speed with high accuracy and performing surge index calculation and lean limit determination in steps 10 and 11 from this rotational change rate. Then, in process 12, a corrected air-fuel ratio suitable for the operating state is calculated. Then, the value of the process 12 is added to the target air-fuel ratio to correct the target air-fuel ratio. Further, this value is input to processing 17 to change the target air-fuel ratio data. Next, the air-fuel ratio is detected and estimated with high accuracy using an O ₂ sensor. That is, the target air-fuel ratio data is learned when the target air-fuel ratio becomes the theoretical air-fuel ratio (A / F = 14.7) in process 13, and the air-fuel ratio at lean combustion is calibrated based on the learning result at the stoichiometric air-fuel ratio. To do. Then, in process 14, the target air-fuel ratio data is searched, and in process 15, the fuel amount is calculated and output to the fuel injection device. Output value of processing 14 at this time (target air-fuel ratio)
Is input to processing 16 and it is determined whether the NOx emission amount is the limit air-fuel ratio. If it is the limit air-fuel ratio, the target air-fuel ratio data is changed in process 17.

3A to 3C are control flowcharts of FIG. FIG. 3A shows the processing 10, 1 of FIG.
1, 12 and 17 details. First, in process 18, in order to detect the rotation speed of the internal combustion engine with high accuracy, signals Nem and Nec using two methods of pulse width measurement and pulse number counting are read. Next, in process 19, it is determined whether or not the current operating state is steady. Xm (n-1) and Xm (n-2) are average values of the pulse width measurement signal counters of the previous time and the previous time, respectively. If Xm (n-1) and Xm (n-2) are different, the process returns, and if they are the same, the process 20 is performed. In the process 20, the surge index S which is the reference of the torque fluctuation is set to Nem, Nec.
And the function f _{1 of} Xm (n-1). Then, the process 21
Then, the variance V (c) of the surge index S is calculated. This V (c)
Corresponds to torque. In process 22, it is determined whether the variance V (c) is larger than a preset torque fluctuation limit value VL.

When V (c) ≤VL, the torque fluctuation is not considered and the routine returns. If V (c)> VL, it is regarded as a torque fluctuation, and the process proceeds to step 23, where the difference ΔV between V (c) and VL is obtained. Then, in process 24, the corrected air-fuel ratio ΔKMR is calculated using the function f ₂ of ΔV and Nec, and in process 25, the data of the target air-fuel ratio KMR is rewritten to the value of KMR + ΔKMR and the process returns. FIG. 3B shows details of the processes 13, 14 and 15 in FIG. First, in step 26, the O ₂ sensor signal A / F,
The air amount Qa, the KMR and Nec are read. Next, in process 27, it is judged whether KMR is 14.7 (theoretical air-fuel ratio). Here, it is necessary to accurately estimate the actual air-fuel ratio in the lean burn region by using the O ₂ sensor. So O
_The target air-fuel ratio data is calibrated in the state of 14.7, which is the air-fuel ratio detectable by the _two sensors. Yes in process 27
In the case of, the routine proceeds to step 28, where it is judged if the target air-fuel ratio KMR is equal to the actual air-fuel ratio A / F. If they are equal, the process proceeds to step 29 and the previous correction constant k ₁ is held. If they are not equal, the process proceeds to step 30, and the correction constant k _{1 is set} to KMR and
It is obtained from the function f _{3 of} / F and changed. Then, the process proceeds to step 31, and the data table of the target air-fuel ratio KMR is searched.
Next, in process 32, the fuel amount Ti is changed to ΔKMR, KMR, Nec.
And Qa are multiplied by the function f ₄ and k _1, and the result is output in process 33. In the case of No in the process 27, the air-fuel ratio cannot be calibrated, so the process advances to the process 29. FIG. 3C shows details of the processes 16 and 17 in FIG. First, in step 34, the target air-fuel ratio KMR
To read processing 35. In process 35, it is determined whether the target air-fuel ratio KMR is equal to or less than the NOx emission limit air-fuel ratio KMR ₀ . The value of this KMR ₀ is preset to, for example, 22. If No, it returns and Ye
In the case of s, the routine proceeds to step 36, where the data table of the target air-fuel ratio KMR is rewritten to 14.7 to prevent an increase in the NOx emission amount.

FIG. 4 is an operating characteristic diagram of the present invention. For example, assume that the air-fuel ratio at the time of a new vehicle is set to 25. After that, the lean combustion limit air-fuel ratio must be gradually reduced to less than 25 due to the change with time. When the air-fuel ratio reaches 22, the air-fuel ratio is switched stepwise to 14.7 in order to prevent the NOx emission amount from increasing. This makes it possible to achieve both fuel efficiency and exhaust gas.

FIG. 5 is a control block diagram when air amount control is added. Means 1 to 9 are the same fuel amount control as in FIG. With this fuel amount control alone, torque fluctuations due to air-fuel ratio changes occur, so torque correction by air amount control is essential. Therefore, first, the torque required by the driver is calculated by the target torque calculation means 37. Then, the target torque and the actual torque detected by the torque detecting means 1 are input to the comparing means 38 and compared. This comparison means 38
The target air amount calculation means 39 calculates the target air amount from the deviation obtained in step (1). Then, the throttle opening calculation means 40
Calculates the target throttle opening and outputs it to the throttle controller 41. Although an example of the electronically controlled throttle is shown here, other air amount control means include an idle speed controller, a supercharger and a variable valve timing controller.

FIG. 6 is a detailed control flowchart of the air amount control. First, in step 42, the accelerator opening α, the pulse count signal Nec, the torque converter output shaft speed Nt.
And the target air-fuel ratio KMR are read. Then, the routine proceeds to step 43, where the target internal combustion engine torque Tetar required by the driver is obtained from the function f ₅ of α, Nec. Next, the routine proceeds to step 44, where the actual internal combustion engine torque Tereal is calculated using the characteristics of the torque converter. Using the torque converter characteristic, Tereal can be obtained by multiplying the square of Nec by the pump capacity coefficient c which is a function of Nt and Nec. Then, using the results of processing 43 and 44, processing 45 is performed.
In step 46, the corrected internal combustion engine torque ΔTe is obtained, and in step 46, the target internal combustion engine torque Tetar is corrected. In step 47, the data table of Tetar, Nec, and throttle opening θ for each target air-fuel ratio KMR is searched to calculate the target throttle opening. Then, in process 48, the throttle opening θ is output. Here, the throttle opening calculation can also be performed by a model using a mathematical formula. Further, regarding the detection of the actual internal combustion engine torque, the rotation difference between the actual torque sensor attached to the drive shaft, the combustion pressure sensor that directly detects the pressure in the internal combustion engine cylinder, and the rotation sensor attached before and after the drive shaft ( Twist) can be used.

FIG. 7 is a basic control block diagram of a lean burn internal combustion engine. This system was based on the target internal combustion engine torque. The block 49 has an air-fuel ratio of 14.7.
The characteristics of the internal combustion engine torque, the internal combustion engine speed and the throttle opening at this time are used. That is, if this characteristic is targeted, the operating characteristic of the conventional internal combustion engine can be satisfied. Therefore, the accelerator opening is input instead of the throttle opening, and the internal combustion engine speed is also input. Further, by setting the actual internal combustion engine torque as the target internal combustion engine torque, the driver's request can be satisfied. Therefore, the target internal combustion engine torque is obtained and output. The target internal combustion engine torque and the engine speed are used to determine the fuel amount, the air amount, and the ignition timing. First, depending on the operating region, for example, a lean air-fuel mixture may misfire depending on the operating region, and at high revolutions and high loads, the lean air-fuel mixture may not be produced due to the output. Therefore, there is no choice but to divide the air-fuel ratio region like the block 50. Here, the air-fuel ratio 23 is selected. Next, in block 51, the air-fuel ratio 23, the target engine torque and the engine speed are input, and the target throttle opening set for each air-fuel ratio is selected and output. Finally, in block 52, the target ignition timing is selected and output from the target engine torque and engine speed.
The ignition timing is MBT (Minimumadvance for the
Best Torque) value is set.

FIG. 8 is a block diagram of torque correction control when changing the air-fuel ratio. First, the signals of the air-fuel ratio data change end determination means 53 for determining whether the air-fuel ratio data change is completed and the torque detection means 54 for detecting the output shaft torque state are input to the MBT determination means 55. The MBT determining means 55 detects the torque state during ignition timing control, which will be described below, and determines the MBT. Then, the ignition timing correction means 56 executes the ignition timing correction according to the torque state judged by the MBT judgment means 55. Further, the value of the target ignition timing data storage means 57 is changed by using the target ignition timing data changing means 58 according to the correction result. Also,
The comparison stop start signal generation means 59 generates a comparison stop signal to the comparison means 38 so as not to operate the throttle opening in order to find the ignition timing of the MBT. The ignition timing is determined by the ignition timing correction means 56 and the target ignition timing data storage means 57.
Is calculated by the ignition timing calculation means 60 and output to the ignition device 61. MBT by MBT judging means 55
When it is determined that the comparison is started, the generation means 59 outputs a comparison start signal to the comparison means 38 to permit throttle control. The throttle control corresponding to the torque change due to the ignition timing control is the same as that described in FIG.

FIGS. 9A and 9B are detailed control flowcharts of ignition timing control. Here, block 5 of FIG.
3 to 60 will be described. First, in step 62, the accelerator opening α, the pulse number count signal Nec, the torque converter output shaft speed Nt, the target air-fuel ratio KMR, the air-fuel ratio change flag FlgA and the air-fuel ratio change state flag FlgB are read. Then, the routine proceeds to step 63, where the actual engine torque Tereal is calculated using the characteristics of the torque converter. Method is Figure 6
Is the same as the description. Next, in process 64, it is determined whether FlgA is 1. In the case of 1, it indicates that the change of the air-fuel ratio data has been completed, and the routine proceeds to step 65, where the MBT control is executed. 1
Otherwise, it is returned. In process 65, 1 is output to the comparison stop start flag FlgC for stopping the correction by the throttle control (air amount control). Then, the routine proceeds to step 66, where it is judged by FlgB whether the air-fuel ratio change is on the rich side or the lean side. If rich, then step 67; if lean, then step 6
Proceed to 8. The MBT is detected by dividing and adding, for example, each 1 deg crank angle. Then, the process proceeds to step 69, where the previous actual engine torque Tereal (n-1) is set to the current Tere
Input al and proceed to step 70. In process 70, a change in engine torque due to a change in ignition timing is detected and fed back. In process 70, Tereal and Tereal (n-1)
When the values are equal to each other, the process proceeds to step 71, the area of the target ignition timing adv is rewritten to the value of adv + Δadv, and in step 72, 0 is written in the comparison stop start flag FlgC and the process is returned. Figure 9 (b)
Is the ignition timing control by interruption. In process 73, the corrected ignition timing Δadv, the air amount Qa, and the pulse count signal N
Read ec. In process 74, the data table of the ignition timing adv is searched, and in process 75, the target ignition timing ADV is set to the above ad.
Calculate using v and Δadv. Then, in step 76, the target ignition timing ADV is output.

FIG. 10 is a block diagram of shock prevention control due to a change in the air-fuel ratio. First, the engine speed and the accelerator opening are input to processing 77 to calculate the target engine torque required by the driver. Next, the routine proceeds to step 78, where the target fuel injection width commensurate with the target engine torque is calculated.
Here, at the same time, the calculation is executed by using the reverse intake pipe model of the process 79, and the target engine torque, that is, the air amount corresponding to the target fuel injection width (throttle opening, shunt valve opening).
Is output. As a result, the target engine torque is set even when the air-fuel ratio is changed while the accelerator opening is constant, and the fuel injection width is maintained, so the air-fuel ratio can be changed without torque fluctuation. Further, in order to improve the accuracy of the fuel amount control, the processing 8
It is necessary to correct the target fuel injection width by feeding back the air quantity (HW: Hot Wire) sensor signal and the engine speed at 0 to calculate the actual fuel injection width. Further, in the steady state, the O ₂ sensor signal or the like is fed back in step 81 to correct the air-fuel ratio map to correct the target fuel injection width. This fuel holding control is optimal when the air-fuel ratio is changed at the time of transient and steady state.

FIG. 11 is a time chart of the embodiment shown in FIG. Since the actual engine torque with respect to the valve opening differs depending on the relationship between the throttle and the mounting position of the diversion valve (described later), it is necessary to delay the change in the diversion valve opening. The model of the process 79 solves this. Further, for example, when the air-fuel ratio is changed while the target engine torque is constant, the air amount is changed for a constant fuel amount, so that the air-fuel ratio can be changed without torque fluctuation.

FIG. 12 is a system configuration diagram. A transmission 83, an exhaust pipe 84, and an intake pipe 85 are attached to the lean burn engine 82. The transmission 83 includes a torque converter input shaft rotation sensor 86, a torque converter output shaft rotation sensor 87, and a transmission output shaft rotation sensor 8.
8, torque sensor 89 and shift control actuator 9
0 is provided. These signals are input / output in the engine powertrain control unit 91. Also,
The exhaust pipe 84 has an O ₂ sensor (air-fuel ratio sensor) 92,
A three-way catalyst 93 and a NOx reduction catalyst 94 are provided. An ignition device 95 is attached to the lean burn engine 82. Further, in the intake pipe 85, an air amount sensor 96, a throttle controller 97, a fuel injection device 98,
A flow dividing valve 99 that forms a swirl for lean combustion, a flow dividing valve motor 100, and a swirl forming passage 101 are provided. The signal from the accelerator sensor 102 is also input to the engine powertrain control unit 91.
This enables the present invention to be implemented.

[0021]

According to the present invention, lean combustion control can be realized in accordance with the driver's request in consideration of changes with time of the components of the lean burn internal combustion engine and the components of the control device, so that fuel consumption and exhaust gas can be reduced. It is possible to provide a control device and a control method for a lean-burn internal combustion engine that does not deteriorate the gas harmful component reduction performance and drivability.

[Brief description of drawings]

FIG. 1 is a control block diagram of an embodiment of the present invention.

FIG. 2 is a specific control block diagram of FIG.

FIG. 3 is a control flowchart of FIG.

FIG. 4 is an operation characteristic diagram of the present invention.

FIG. 5 is a control block diagram when air amount control is added.

FIG. 6 is a detailed control flowchart of air amount control.

FIG. 7 is a basic control block diagram of a lean burn engine.

FIG. 8 is a block diagram of torque correction control when changing the air-fuel ratio.

FIG. 9 is a detailed control flowchart of ignition timing control.

FIG. 10 is a block diagram of shock prevention control due to a change in air-fuel ratio.

11 is a time chart of the embodiment shown in FIG.

FIG. 12 is a system configuration diagram.

[Explanation of symbols]

1 ... Torque detecting means, 2 ... Lean combustion limit determining means, 3 ...
Air-fuel ratio correction means, 4 ... Air-fuel ratio detection means, 5 ... NOx emission limit air-fuel ratio determination means, 6 ... Target air-fuel ratio data change means, 7 ... Target air-fuel ratio data storage means, 8 ... Fuel amount calculation means, 9 ... Fuel injection device.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number in the agency FI Technical indication location F02D 43/00 K F02P 5/15 (72) Inventor Matsuo Amano Katsuta City, Ibaraki 2520 Takaba Hitachi, Ltd. Automotive Equipment Division

Claims (20)

[Claims] 1. An air-fuel ratio control means for controlling an air-fuel ratio of an internal combustion engine, a lean limit air-fuel ratio determining means for detecting an output torque fluctuation of the internal combustion engine and determining a lean limit air-fuel ratio, and an exhaust gas of the internal combustion engine. With a limit air-fuel ratio comparison means for comparing the lean air-fuel ratio with the limit air-fuel ratio corresponding to a predetermined amount of nitrogen oxide component emissions, the air-fuel ratio control means is based on this comparison result An output torque control device for an internal combustion engine, which controls an air-fuel ratio. 2. A stoichiometric air-fuel ratio is detected using an oxygen sensor (O ₂ sensor) in the air-fuel ratio control means, and a target air-fuel ratio operation range based on the stoichiometric air-fuel ratio is detected. A target air-fuel ratio learning means for learning the fuel ratio and a target air-fuel ratio calibration means for calibrating the target air-fuel ratio of the lean air-fuel mixture by using the learned target air-fuel ratio value learned by the target air-fuel ratio learning means are provided. A characteristic output torque control device for an internal combustion engine. 3. The target air-fuel ratio according to claim 2, wherein the target air-fuel ratio is expressed as data in the air-fuel ratio control means and the changed target air-fuel ratio data changed when the target air-fuel ratio data is changed is written. An output torque control device for an internal combustion engine, which is provided with data changing means. 4. The output torque control device for an internal combustion engine according to claim 1, wherein the air-fuel ratio control means is provided with a torque correction means for correcting the output torque of the internal combustion engine. 5. The output torque control device for an internal combustion engine according to claim 4, wherein the amount corrected by the torque correction means is an amount of air taken into the internal combustion engine. 6. The output torque control device for an internal combustion engine according to claim 4, wherein the amount corrected by the torque correction means is an ignition timing. 7. The output torque control device for an internal combustion engine according to claim 4, wherein the amount corrected by the torque correction means is an amount of air taken into the internal combustion engine and an ignition timing. 8. The output torque control device for an internal combustion engine according to claim 7, wherein the air amount is corrected after the ignition timing is corrected. 9. The target torque calculating means for calculating a target torque as a control target value of the output torque of the internal combustion engine according to claim 1, and a target for determining a target fuel amount according to the value of the target torque. An output torque control device for an internal combustion engine, comprising: a fuel injection width calculation means. 10. The amount of air taken into the internal combustion engine based on the target torque and the target fuel amount by modeling the performance characteristic of the intake pipe of the internal combustion engine according to claim 9. An output torque control device for an internal combustion engine, which is provided with an air amount calculating means for calculating 11. An air-fuel ratio control means controls the air-fuel ratio of an internal combustion engine, and a lean limit air-fuel ratio determination means detects an output torque fluctuation of the internal combustion engine to determine a lean limit air-fuel ratio,
The limit air-fuel ratio comparison means compares the limit air-fuel ratio and the lean limit air-fuel ratio corresponding to a predetermined amount of the nitrogen oxide component emission amount in the exhaust gas of the internal combustion engine, and the air-fuel ratio control means is An output torque control method for an internal combustion engine, characterized in that the air-fuel ratio is controlled based on the comparison result. 12. The air-fuel ratio control means is provided with a target air-fuel ratio learning means and a target air-fuel ratio calibration means, and the target air-fuel ratio learning means uses an oxygen sensor (O ₂ sensor). The stoichiometric air-fuel ratio is detected, and the target air-fuel ratio is learned in the stoichiometric air-fuel ratio operating range based on the stoichiometric air-fuel ratio, and the target air-fuel ratio calibrating means uses the value of the learned target air-fuel ratio learned by the target air-fuel ratio learning means. A method for controlling output torque of an internal combustion engine, characterized in that a target air-fuel ratio of a lean mixture is calibrated. 13. The air-fuel ratio control means is provided with a target air-fuel ratio data changing means, and the target air-fuel ratio data changing means represents the target air-fuel ratio as data.
An output torque control method for an internal combustion engine, characterized in that the changed target air-fuel ratio data is written when the target air-fuel ratio data is changed. 14. The output torque control method for an internal combustion engine according to claim 11, wherein the air-fuel ratio control means is provided with torque correction means, and the torque correction means corrects the output torque of the internal combustion engine. . 15. The output torque control method for an internal combustion engine according to claim 14, wherein the amount corrected by the torque correction means is the amount of air taken into the internal combustion engine. 16. The output torque control method for an internal combustion engine according to claim 14, wherein the amount corrected by the torque correction means is an ignition timing. 17. The output torque control method for an internal combustion engine according to claim 14, wherein the amount corrected by the torque correction means is the amount of air taken into the internal combustion engine and the ignition timing. 18. The output torque control method for an internal combustion engine according to claim 17, wherein the air amount is corrected after the ignition timing is corrected. 19. The target torque calculating means and the target fuel injection width calculating means according to claim 11, wherein the target torque calculating means calculates a target torque which is a control target value of the output torque of the internal combustion engine. The output torque control method for an internal combustion engine, wherein the target fuel injection width calculation means determines a target fuel amount according to the value of the target torque. 20. The air amount calculating means according to claim 19, wherein the air amount calculating means models the performance characteristics of the intake pipe of the internal combustion engine, and the target torque and the target fuel are calculated using the model. An output torque control method for an internal combustion engine, comprising calculating the amount of air taken into the internal combustion engine based on the amount.