JP3269414B2 - Intake air amount control device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake air control device for an internal combustion engine, and more particularly, to an intake air for an internal combustion engine capable of performing stratified combustion and homogeneous combustion, such as a direct injection internal combustion engine. The present invention relates to a quantity control device.

[0002]

2. Description of the Related Art In a conventionally used engine, fuel from a fuel injection valve is injected into an intake port, and a homogeneous mixture of fuel and air is supplied to a combustion chamber in advance. In such an engine, an intake passage is opened and closed by a throttle valve linked to an accelerator operation, and by this opening and closing, the amount of intake air supplied to a combustion chamber of the engine (consequently, a gas mixture in which fuel and air are homogeneously mixed). ) Is adjusted, thereby controlling the engine output.

[0003] However, in the technique based on the so-called homogeneous combustion described above, a large intake negative pressure is generated in accordance with the throttle operation of the throttle valve, and the pumping loss increases to lower the efficiency. On the other hand, by reducing the throttle of the throttle valve and supplying fuel directly to the combustion chamber, a combustible air-fuel mixture is present near the ignition plug, and the air-fuel ratio of the portion is increased.
There is known a so-called "stratified combustion" technique for improving ignitability.

For example, in the technique disclosed in JP-A-63-248938, stratified combustion is achieved by directly injecting fuel into a combustion chamber and appropriately controlling an electronically controlled throttle valve. ing. That is, in the low / medium load and low / medium rotation regions, stratified combustion is executed by suppressing the throttle throttle and causing the combustible mixture to exist near the ignition plug. At this time,
The electronically controlled throttle valve is controlled to be maintained at a predetermined opening. Further, in the high-load / high-speed region, homogeneous combustion is executed instead of the above-described stratified combustion. For this reason,
Combustion according to the load and rotation at that time is executed, and particularly, the fuel economy is improved by "stratified combustion".

In this technology, an exhaust gas recirculation device (EGR device) is provided. In particular, when performing stratified combustion in a low load region, the exhaust gas recirculation amount (E
GR amount).

[0006]

However, the above prior art has the following problems. That is, even if the control means instructs the same throttle opening for the electronically controlled throttle valve, it is not always possible to obtain a constant throttle opening, and the intake air amount varies. There was a risk. This is considered to be due to the influence of deposits that accumulate in the vicinity of the throttle valve over time, individual differences in the throttle valve, errors in the throttle fully closed position at the time of initial (initial), and the like. If the intake air amount varies as described above, the combustion state may be deteriorated, causing a misfire, engine stall, or the like, or deterioration of emission.

In particular, in the above prior art, since the EGR amount is increased during stratified combustion,
In a region where the throttle opening is small, the EGR amount fluctuates greatly even if the throttle opening is slightly shifted. Therefore, there has been a problem that the misfire, engine stall, and the like are more likely to occur.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an intake air amount control device for an internal combustion engine capable of performing stratified combustion, in which the opening degree of an intake air amount control valve is determined. It is an object of the present invention to provide an intake air amount control device for an internal combustion engine that can prevent a deterioration of a combustion state due to an error.

[0009]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, as shown in FIG. 1, an internal combustion engine M21 is provided for performing stratified combustion and homogeneous combustion.
A fuel injection means M22 for injecting fuel into the cylinder, an intake air amount control valve M24 provided in the intake passage M23 of the internal combustion engine M21 for adjusting the amount of intake air supplied into the cylinder, An actuator M25 for driving the intake air amount control valve M24, an operating state detecting means M26 for detecting an operating state of the internal combustion engine M21, and an actuator M25 for detecting the operating state of the intake air amount control valve M24 based on the detection result of the operating state detecting means M26. Intake air amount control means M for calculating an opening instruction value and controlling the actuator M25 based on the opening instruction value to control the intake air amount.
27. The apparatus for controlling the amount of intake air of an internal combustion engine, comprising:
A stable state detecting means M28 for detecting that the internal combustion engine M21 is in a stable state , including a condition that recirculation is not performed; an intake pressure detecting means M29 for detecting an intake pressure in the intake passage M23; The stable state detecting means M28
When it is detected that the internal combustion engine M21 is in a stable state, the reference opening calculation for calculating the reference opening of the intake air amount control valve M24 based on the intake pressure detected by the intake pressure detecting means M29. Means M30, a reference opening calculated by the reference opening calculating means M30, and an opening of the intake air amount control valve M24 based on the opening instruction value, and a correction amount based on the comparison result. Correction amount calculating means M31 for calculating the correction amount calculating means M31 and correction control means for correcting the opening degree instruction value based on the correction amount calculated by the correction amount calculating means M31 during the control by the intake air amount control means M27. The main point is that M32 is provided.

[0010]

(Operation) According to the first aspect of the present invention, the fuel injection means M 2
Than 2, fuel is injected into the cylinders of an internal combustion engine M 21, output by the explosion and combustion of the mixture within the cylinder is obtained. In addition, stratified combustion and homogeneous combustion can be performed depending on the type of injection. By the intake air amount control valve M 24 provided in the intake passage M 23 of an internal combustion engine M 21 is opened and closed,
The opening area of the intake passage M 23 varies, thereby,
The amount of intake air supplied into the cylinder is adjusted. Further, the operating condition detecting means M 26, the requested operation state of the internal combustion engine M 21 is detected. Then, the opening degree command value of the intake air amount control valve M 24 based on the detection result is calculated by the intake air amount control means M 27, by the means M 27, the actuator M 25 based on the opening degree instruction value Controlled. And the actuator M
25 is controlled so that the intake air amount control valve M 24
Are opened and closed, and the intake air amount is controlled.

[0012]

[0013]

[0014]

[0015] Now, the present invention, it is detected by the stable state detection means M28 for the internal combustion engine M21 is in a stable state. Further, the intake pressure in the intake passage M23 is detected by the intake pressure detecting means M29. Then, when the stable state detecting means M28 detects that the internal combustion engine M21 is in a stable state, the reference opening calculating means M30 calculates the reference pressure based on the intake pressure detected by the intake pressure detecting means M29.
The reference opening of the intake air amount control valve M24 is calculated. Then, the reference opening calculated by the reference opening calculating means M30 and the intake air amount control valve M24 based on the opening instruction value.
Is compared by the correction amount calculation means M31, and the correction amount is calculated based on the comparison result by the calculation means M31. Then, the intake air amount control means M
In the control at 27, the opening control value is corrected by the correction control means M32 based on the correction amount calculated by the correction amount calculating means M31.

Therefore, in the present invention, the intake air amount control valve is provided.
The actual opening of M24 indicates the opening for some reason.
Even if the value does not match the value, the correction control means
Inhalation after correcting the opening degree indication value by M32
The control of the air amount control means M27 is executed. Therefore,
The required intake air amount can be obtained appropriately.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an intake air amount control device for an internal combustion engine according to the present invention.

FIG. 2 is a schematic configuration diagram showing an intake air amount control device for a direct injection engine mounted on a vehicle in the present embodiment. Engine 1 as an internal combustion engine, for example, comprises four cylinders 1a, the combustion chamber structure of each cylinder 1a is shown in FIG. As shown in these drawings, the engine 1 includes a piston in a cylinder block 2, and the piston reciprocates in the cylinder block 2. A cylinder head 4 is provided above the cylinder block 2, and a combustion chamber 5 is formed between the piston and the cylinder head 4. Further, in the present embodiment, four valves are arranged per cylinder 1a, and in the figure, the first intake valve 6a, the second intake valve 6b, the first intake port 7a, and the first intake port 7b in the figure. Two intake ports, a pair of exhaust valves as 8, and a pair of exhaust ports as 9 are shown.

As shown in FIG. 3 , the first intake port 7a
Is composed of a helical intake port, and the second intake port 7
b consists of a straight port extending almost straight.
In addition, an ignition plug 10 is disposed at the center of the inner wall surface of the cylinder head 4. Further, a fuel injection valve 11 is disposed around the inner wall surface of the cylinder head 4 near the first intake valve 6a and the second intake valve 6b. That is, in the present embodiment, the fuel from the fuel injection valve 11 is directly injected into the cylinder 1a, and the stratified combustion is performed by appropriately controlling the fuel injection timing. Is available. An ignition signal distributed by a distributor (not shown) is applied to the ignition plug 10. The distributor distributes the high voltage output from the igniter 12 to each spark plug 10 in synchronization with the crank angle of the engine 1, and the ignition timing of each spark plug 10 is determined by the high voltage output timing from the igniter 12. It is determined.

As shown in FIG. 2 , the first intake port 7a and the second intake port 7b of each cylinder 1a are respectively connected via a first intake path 15a and a second intake path 15b formed in each intake manifold 15. Connected to the surge tank 16. A swirl control valve 17 is arranged in each second intake passage 15b. These swirl control valves 17 are connected to, for example, a step motor 19 via a common shaft 18. The step motor 19 is controlled based on an output signal from an electronic control unit (hereinafter simply referred to as “ECU”) 30 described later. Note that instead of the step motor 19,
An engine controlled according to the negative pressure of the intake port of the engine 1 may be used.

The surge tank 16 includes an intake duct 20
Is connected to the air cleaner 21 through the intake duct 20.
Inside, a throttle valve 23 which is opened and closed by a step motor 22 as an actuator is provided. That is, the throttle valve 23 of the present embodiment is of a so-called electronic control type. Basically, the throttle valve 23 is controlled to open and close by the step motor 22 being driven based on the output signal from the ECU 30. Is done. The opening and closing of the throttle valve 23 causes the intake duct 2
The amount of intake air that passes through 0 and is introduced into the combustion chamber 5 is adjusted. In the present embodiment, an intake passage is constituted by the intake duct 20, the surge tank 16, the first intake passage 15a, the second intake passage 15b, and the like. In the vicinity of the throttle valve 23, a throttle sensor 25 for detecting the opening (throttle opening TA) is provided. An exhaust manifold 14 is connected to the exhaust port 9 of each cylinder. And
The exhaust gas after combustion is discharged to an exhaust duct (not shown) through the exhaust manifold 14.

Further, in this embodiment, a known exhaust gas circulation (EGR) device 51 is provided. This EG
The R device 51 includes an EGR passage 5 as an exhaust gas circulation passage.
2 and an EGR valve 53 as an exhaust gas circulation valve provided in the middle of the passage 52. EGR passage 5
2 is an intake duct 20 downstream of the throttle valve 23;
It is provided so as to communicate with the exhaust duct. The EGR valve 53 has a built-in valve seat, valve body, and step motor (all not shown). The opening degree of the EGR valve 53 fluctuates when the stepping motor intermittently displaces the valve body with respect to the valve seat. And EG
When the R valve 53 opens, a part of the exhaust gas discharged to the exhaust duct flows to the EGR passage 52. The exhaust gas flows to the intake duct 20 via the EGR valve 53. That is, a part of the exhaust gas is recirculated into the intake air-fuel mixture by the EGR device 51. At this time, the recirculation amount of the exhaust gas is adjusted by adjusting the opening degree of the EGR valve 53.

The above-described ECU 30 is a digital computer, and is connected to a RAM (random access memory) 3 via a bidirectional bus 31.
2, a ROM (Read Only Memory) 33, a CPU (Central Processing Unit) 34 composed of a microprocessor, an input port 35 and an output port 36. In the present embodiment, the ECU 30 constitutes an intake air amount control unit, a control valve closing control unit, a correction amount calculation unit, and a correction control unit.

An accelerator sensor 26A for generating an output voltage proportional to the amount of depression of the accelerator pedal 24 is connected to the accelerator pedal 24.
Accelerator opening ACCP is detected by 6A. The output voltage of the accelerator sensor 26A is input to the input port 35 via the AD converter 37. Similarly, the accelerator pedal 24 has a fully-closed switch 26B for detecting that the depression amount of the accelerator pedal 24 is "0".
Is provided. That is, the fully closed switch 26B
Generates a signal of “1” as the fully closed signal XL2SW when the depression amount of the accelerator pedal 24 is “0”, and generates a signal of “0” otherwise. The output voltage of the fully closed switch 26B is also input to the input port 35.

The top dead center sensor 27 generates an output pulse when the first cylinder 1a reaches the intake top dead center, for example.
This output pulse is input to the input port 35. The crank angle sensor 28 has a crankshaft of 30 ° CA, for example.
An output pulse is generated each time the motor rotates, and the output pulse is input to the input port. In the CPU 34, the top dead center sensor 2
7 and the output pulse of the crank angle sensor 28, the engine speed NE is calculated (read).

Further, the rotation angle of the shaft 18 is detected by a swirl control valve sensor 29,
Thereby, the opening of the swirl control valve 17 is measured. The output of the swirl control valve sensor 29 is supplied to an input port 35 via an A / D converter 37.
Is input to

At the same time, the throttle sensor 25 detects the throttle opening degree TA. The output of the throttle sensor 25 is input to an input port 35 via an A / D converter 37.

In addition, in the present embodiment, an intake pressure sensor 61 for detecting the pressure (intake pressure PiM) in the surge tank 16 is provided. Further, a water temperature sensor 62 that detects the temperature of the cooling water of the engine 1 (cooling water temperature THW) is provided. The output of both sensors 61 and 62 is also A /
The data is input to the input port 35 via the D converter 37.

In the present embodiment, the throttle sensor 25, the accelerator sensor 26A, the full-close switch 26
B, a top dead center sensor 27, a crank angle sensor 28, a swirl control valve sensor 29, an intake pressure sensor 61, a water temperature sensor 62, and the like constitute an operating state detecting means. A stable state detecting means is constituted by the fully closed switch 26B and the like. Further, the intake pressure sensor 61
Constitutes an intake pressure detecting means.

On the other hand, the output port 36 is connected to each of the fuel injection valves 11 and each of the step motors 1 via a corresponding drive circuit 38.
9, 22, the igniter 12 and the EGR valve 53 (step motor). Then, based on signals from the sensors 25 to 29, 61, and 62, the ECU 30 operates according to a control program stored in the ROM 33,
The fuel injection valve 11, the step motors 19 and 22, the igniter 12, the EGR valve 53 and the like are suitably controlled.

Next, a program related to various controls according to the present embodiment in the engine intake air amount control device having the above configuration will be described with reference to flowcharts. FIG. 4 shows a step motor 22 (throttle valve 2) executed by ECU 30 in the present embodiment.
3 is a flowchart showing a "throttle opening degree setting routine" for controlling the opening degree (3) and controlling the intake air amount, and is executed in the main routine.

When the process proceeds to this routine, the ECU
First, at step 101, various sensors 2
5, 26A, 26B, 27-29, 61, 62, etc., various signals such as the engine speed NE and the accelerator opening ACCP are read, and a throttle closing execution flag X
The TRTST, the closing amount TRTC, the throttle learning value TRTST corresponding to the correction amount, and the like are read from the RAM 32. Note that the throttle closing execution flag XTRTS
The T, the confinement amount TRTC, the learning value TRTST, and the like will be described later.

Next, at step 102, the currently read engine speed NE and accelerator opening ACC are read.
Based on P, a basic instruction value TRTRATM relating to the opening of the throttle valve 23 is calculated. This basic indication value TRT
RATM is the engine speed NE and accelerator opening AC
The CP is calculated by referring to a map in which the basic instruction value TRTRATM is set in advance, and is calculated as the number of steps of the step motor 22.

In the following step 103, the throttle closing execution flag XTRT read this time is read.
It is determined whether or not ST is “1”. Here, the throttle closing execution flag XTRTST is a flag indicating whether or not the closing control of the throttle valve 23 is to be executed, and is set by a separate routine (not shown). . That is, the throttle closing execution flag XTRTST is set to “1” by a separate routine, for example, when the engine 1 is started, after the warm-up is completed, and when the engine is idling for the first time. In this case, the closing control is executed in the subsequent processing. The throttle closing execution flag XTR
When TST is “1”, the target EGR opening degree EGRP is set to “0”, and the EGR control is not executed. On the other hand, if the above condition is not satisfied, the throttle closing execution flag XTR
TST is set to “0”, and in such a case, the closing control is not executed.

If it is determined in step 103 that the throttle closing execution flag XTRTST is "1", the process proceeds to step 104 to execute closing control. In step 104,
A value obtained by subtracting the currently read closing amount TRTC (calculated by a “closing amount calculation routine” described later) from the basic instruction value TRTRATM regarding the opening degree of the throttle valve 23 calculated this time is a temporary instruction value. Set as TRTRATA.

In step 105, the ECU 3
A value of 0 determines whether or not the provisional instruction value TRTRATA set this time is equal to or greater than a predetermined lower-limit reference value TRTMIN. Here, the lower limit reference value TRTMIN is an opening at which an engine stall may occur when the actual throttle opening (the number of steps) falls below the value. Then, in this processing, if the provisional instruction value TRTRATA is lower than the lower reference value TRTMIN, in step 106, the lower reference value TRTMIN is reduced to the provisional instruction value TRTRATA.
And the process proceeds to step 107.
On the other hand, provisional indicated value TRTRATA is
If it is equal to or greater than RTMIN, the process directly proceeds to step 107.

In step 107, the provisional instruction value TRTRATA which is currently set is set as the final throttle instruction value TRTRAT, and the subsequent processing is temporarily terminated. Thus, the closing control of the throttle valve 23 is executed.

If it is determined in step 103 that the throttle closing execution flag XTRTST is "0", the closing control is not executed but the closing control is executed.
It is determined that normal correction control is to be executed, and step 10
Move to 8.

In step 108, a basic instruction value TRTR relating to the opening degree of the throttle valve 23 calculated this time.
The value obtained by adding the learning value TRTST read this time to the ATM is set as the final throttle instruction value TRTRAT, and the subsequent processing is temporarily terminated. Thus, the correction control of the opening degree of the throttle valve 23 is executed.

As described above, in the "throttle opening degree setting routine", the throttle valve 23 is set in accordance with the throttle closing execution flag XTRTST at that time.
Of the throttle valve 23 or correction control of the opening of the throttle valve 23 is performed.

Next, in performing the above-described closing control,
The processing content for calculating the employed closing amount TRTC will be described. That is, FIG. 5 is a flowchart showing a “closed amount calculation routine” executed by the ECU 30 and includes a predetermined crank angle (for example, “36”).
0 ° CA ”).

When the processing shifts to this routine, the ECU
First, at step 201, the fully closed switch 2
6B, various signals such as a full-close signal XL2SW, intake pressure PiM, etc. are read based on detection signals from various sensors such as the intake pressure sensor 61, a throttle closing execution flag XTRTST already described, and a throttle closing described later. Read the completion flag XTRTSTE.

In the following step 202, it is determined whether or not the currently-closed fully closed signal XL2SW is "1". When the fully closed signal XLL2SW is “1”, it is determined that the current time is the idling time, and the process proceeds to step 203.

In step 203, it is determined whether or not the currently read throttle closing execution flag XTRTST is "1". When the throttle closing execution flag XTRTST is “1”, it is determined that the closing control of the throttle valve 23 is being executed, and the process proceeds to step 204.

In step 204, it is determined whether or not the currently read throttle closing completion flag XTRTSTE is "0". The throttle closing completion flag XTRTSTE is set to “0” when the closing control of the throttle valve 23 is not completed, and is set to “1” when the closing control of the throttle valve 23 is completed. Things. The flag XT
RTSTE is set to “1” when a predetermined condition is satisfied in a “learning value calculation routine” described later.
If the throttle closing completion flag XTRTSTE is "0" in step 204, the control proceeds to step 205 on the assumption that the closing control is being executed and has not been completed yet.

In step 205, it is determined whether or not the intake pressure PiM read this time is equal to or less than a predetermined value C5. That is, when the closing control is being performed in the "throttle opening control routine", the throttle valve 23 is closed by the closing amount TRTC, and the intake pressure PiM Should also drop. Then, the intake pressure Pi
Until M decreases to the predetermined value C5, steps 205 to 207 are executed to execute the closing control of the throttle valve 23.
Is performed.

In step 205, the intake pressure PiM
Is less than or equal to a predetermined value C5, it is determined that there is no need to perform further closing.
In step 206, the current confinement amount TRTC is set as it is as a new confinement amount TRTC. On the other hand, if the intake pressure PiM has not yet become equal to or less than the predetermined value C5, in order to perform closing, that is, increase the closing amount TRTC, until the intake pressure PiM becomes equal to or less than the predetermined value C5.
The value obtained by adding “1” to the current confinement amount TRTC is set as a new confinement amount TRTC. Then, the ECU 30 once ends the subsequent processing.

In step 204, the throttle closing completion flag XTRTS read this time is read.
If TE is not “0”, that is, if “1”, it is determined that the closing control of the throttle valve 23 has been completed, and the routine proceeds to step 208. In step 208, it is determined whether or not the current closing amount TRTC is “0”. And the confinement amount TRTC is “0”.
Otherwise, since the closing control has already been completed, the closing is released thereafter (the closing amount TRTC is set to “0”).
Then, the process proceeds to step 209.

In step 209, a value obtained by subtracting "1" from the current confinement amount TRTC is set as a new confinement amount TRTC. By repeating this, after the closing control is completed, the closing amount TRTC gradually approaches “0”. Then, the ECU 30 once ends the subsequent processing.

If the current closing amount TRTC is "0" in step 208, the closing control has already been completed and the closing amount TRTC is "0".
, The subsequent processing is temporarily terminated.

Further, if the fully closed signal XLL2SW is "0" in step 202, it is determined that the vehicle is not idling, and the process proceeds to step 210. In step 203, when the throttle closing execution flag XTRTST is "0", it is determined that the closing control of the throttle valve 23 is not performed, and the process proceeds to step 210 similarly. Then, in step 210, the closing amount TRTC is set to “0”. In the following step 211, the throttle closing completion flag XTRTSTE is set to “0”. Then, the subsequent processing ends once.

As described above, in the above-described "closing amount calculation routine", the throttle closing execution flag XTRTST is set to "1" at the time of idling, and the throttle closing completion flag XTRTS is set.
When TE is set to “0”, the closing amount TRTC is calculated such that the intake pressure PiM becomes the predetermined value C5 in order to execute the closing control.

Next, a description will be given of the contents of processing for calculating the learning value TRTST to be employed in executing the above-described opening degree correction control of the throttle valve 23. That is,
FIG. 6 is a flowchart showing a “learning value calculation routine” executed by the ECU 30. The routine is executed by a periodic interruption every predetermined time (for example, “50 ms”).

When the processing shifts to this routine, the ECU
First, in step 301, the intake pressure PiM and the engine speed NE are calculated based on the detection of various sensors and the like. Also, the target EGR opening degree EGR calculated separately is
P, a count value CTRTST set in a “count value setting routine” described later, and a final throttle instruction value TRTRA calculated in the “throttle opening degree setting routine”.
Read T etc.

Next, in step 302, the current learning value TRTST is set as the previous learning value TRTSTB. Further, in step 303, it is determined whether or not the current target EGR opening degree EGRP is “0”. Then, the current target EGR opening degree EGRP is “0”.
If not, it is determined that the EGR control is currently being performed and the learning value is not being calculated, and the subsequent processing is temporarily terminated. Also, the current target EGR opening degree EGRP
Is “0”, the process proceeds to step 304.

In step 304, a value obtained by subtracting the previously read intake pressure PiM _i-1 from the current intake pressure PiM _i is set as the intake pressure deviation ΔPiM. In step 305, the intake pressure deviation ΔPiM
Is determined to be within a predetermined range, that is, whether the intake pressure deviation ΔPiM is equal to or more than a predetermined value C0 and equal to or less than C1. When the intake pressure deviation ΔPiM is not within the predetermined range, the variation of the intake pressure PiM is large,
It is determined that the engine 1 is not in a stable state, and the subsequent processing is temporarily terminated. If the intake pressure deviation ΔPiM is within the predetermined range, the process proceeds to step 306.

In step 306, the count value CTRTST read this time is set to a predetermined value C
It is determined whether it is 2 or more. Here, the count value CTRTST is generally counted up when there is little change in the above-mentioned final throttle instruction value TRTRAT. That is, the fact that the count value CTRTST is equal to or greater than the predetermined value C2 indicates that a state in which the final throttle instruction value TRTRAT has little change is maintained for a predetermined time. The method of setting the count value CTRTST will be described later. If the count value CTRTST is equal to or more than the predetermined value C2 in step 306, the affirmative determination is made in the processing in steps 303, 305, and 306, and the engine 1
Can be determined to be in a stable operating state. Therefore, it is determined that the learning value can be calculated thereafter, and the process proceeds to step 307.

In step 307, a throttle reference opening TRTRATO (expressed by the number of steps) is calculated based on the engine speed NE and the intake pressure PiM which are read this time. Here, the throttle reference opening TRTR
AT0 is calculated by referring to the map as shown in FIG. That is, during the operation at a certain engine speed NE, if the throttle opening at that time is a certain opening, the intake pressure PiM at that time is uniquely determined. Therefore, conversely, if the current engine speed NE and the intake pressure PiM are certain values, the original throttle opening should be uniquely determined. The throttle reference opening TR is determined in this manner.
TRATO.

Next, in step 308, a value obtained by subtracting the currently set throttle reference opening TRTRAT0 from the currently read final throttle instruction value TRTRAT is set as the current throttle learning value TRTSTN. Therefore, the throttle learning value TRTSTN thus set can be considered to correspond to an error between the actual throttle opening and the reference opening.

Further, in the following step 309,
Assuming that the learning has been completed for the time being, the throttle closing completion flag XTRTSTE is set to "1".
In step 310, it is determined whether or not the absolute value of the value obtained by subtracting the previous learning value TRTSTB from the current throttle learning value TRTSTN is equal to or less than a predetermined value C3. If the absolute value of the value obtained by subtracting the previous learning value TRTSTB from the current throttle learning value TRTSTN is equal to or less than a predetermined value C3, it is determined that the learning value does not change much, and the process proceeds to step 31.
Move to 1.

In step 311, the current throttle learning value TRTSTN is set as it is as the final learning value TRTST, and the subsequent processing is temporarily terminated. Then, the learning value TRTST set in this way is used for the correction control in the "throttle opening degree setting routine".

In the throttle 310, the current learning value TRTSTN is changed from the previous learning value TRTSTN to the previous learning value TRTSTN.
If the absolute value of the value obtained by subtracting RTSTB is not less than the predetermined value C3, it is determined that the fluctuation amount becomes too large if the current throttle learning value TRTSTN is directly set as the learning value TRTST. And
Move to step 312.

In step 312, the current throttle learning value TRTSTN is changed to the previous learning value TRTST.
It is determined whether it is B or more. When the current throttle learning value TRTSTN is equal to or greater than the previous learning value TRTSTB, a value obtained by adding the predetermined value C3 to the previous learning value TRTSTB is set as a final learning value TRTST, and the subsequent processing is performed. Stop once. In contrast, at step 312, the current throttle learning value TRTS
If TN is smaller than the previous learning value TRTSTB, a value obtained by subtracting the predetermined value C3 from the previous learning value TRTSTB is set as the final learning value TRTST, and the subsequent processing is temporarily terminated. As described above, in the “learning value calculation routine”, when it is determined that the operating state of the engine 1 at that time is in a stable state, the final learning value TRTST is calculated. The learning value TRTST at this time is a value obtained by subtracting the throttle reference opening TRTRAT0 from the final throttle instruction value TRTRAT,
That is, it is set based on the current throttle learning value TRTSTN.

Although the explanation has been simplified in step 306, the count value CTRTS will be described below.
The processing for calculating T will be described. That is, FIG. 8 is a flowchart of the “count value setting routine” executed by the ECU 30, and is executed by a periodic interruption every predetermined time (for example, “10 ms”).

When the processing shifts to this routine, the ECU
First, at step 401, the final throttle instruction value TRTRAT and the previous final throttle instruction value TR
Read TRATB etc.

Next, at step 402, it is determined whether or not the absolute value of the value obtained by subtracting the previous final throttle instruction value TRTRATB from the presently read final throttle instruction value TRTRAT is equal to or less than a predetermined value C4. Judge. And the final throttle instruction value TR of this time
From TRAT to the last final throttle indication value TRTRAT
When the absolute value of the value obtained by subtracting B is equal to or smaller than the predetermined value C4, there is not much change between the last throttle instruction value and the last throttle instruction value, and the operating state of the engine 1 is stable in a sense. The process proceeds to step 403.

In step 403, a value obtained by adding “1” to the previous count value CTRTST is set as a new count value CTRTST in order to count up, and the process proceeds to step 405.

On the other hand, in step 402, if the absolute value of the value obtained by subtracting the previous final throttle instruction value TRTRATB from the current final throttle instruction value TRTRAT is larger than a predetermined value C4, the count value CT
The RTST is cleared to “0”, and the process proceeds to step 405.

After shifting from step 403 or step 404, in step 405, the current final throttle instruction value TRTRAT is set as the last final throttle instruction value TRTRATB, and is temporarily stored in the ROM 32. Then, the subsequent processing ends once.

As described above, the "count value setting routine"
In this case, the final throttle instruction value TRTRAT
The count value CTRTST is counted up or cleared to "0" based on the difference between the last throttle instruction value TRTRATB and the previous value.

Next, the specific operation and effect of the present embodiment will be described. (A) As described above, in the present embodiment, the engine 1
Is determined to be in the idling state,
When the throttle closing execution flag XTRTST is “1”, the closing control is executed. That is, the closing amount TRTC continues to increase until the intake pressure PiM becomes equal to or less than the predetermined value C5. And
From the basic instruction value TRTRATM, the confinement amount TRT
The value subtracted by C is set as the final throttle instruction value TRTRAT in principle.

In the "learning value calculation routine", when it is determined that the operating state of the engine 1 at that time is in a stable state, the final throttle instruction value TRT is set.
The throttle learning value TRTSTN is set based on the difference between the RAT and the throttle reference opening TRTRAT0.
In controlling the throttle opening, the final throttle instruction value TRTRAT is set after considering (correcting) the learned value TRTSTN, and the opening of the throttle valve 23 is controlled.

For this reason, the actual opening degree of the throttle valve 23 may vary for some reason (the effect of deposits that accumulate in the vicinity of the throttle valve 23 over time, individual differences in the throttle valve 23,
Even if the basic instruction value TRTRATM does not become the same as the basic instruction value TRTRATM due to the error of the throttle fully closed position at the time of initial (initial), the learning value TRTSTN is added to the basic instruction value TRTRATM by the correction (learning) control.
The control of the opening degree of the throttle valve 23 is executed after the correction is made by the amount. Therefore, the required intake air amount can be obtained appropriately. As a result, the throttle valve 2
The deterioration of the combustion state due to the error of the opening degree 3 can be prevented. As a result, it is possible to reliably prevent the occurrence of problems such as misfire and engine stall due to deterioration of the combustion state.

(B) In this embodiment, in the "throttle opening degree setting routine", the provisional instruction value TRTR is set.
When the ATA falls below a predetermined lower limit reference value TRTMIN, the lower limit reference value TRTMIN is newly replaced as a temporary instruction value TRTRATA.
Therefore, it is possible to avoid a situation in which engine stall occurs when the provisional instruction value TRTRATA is too low.

(C) Further, in the present embodiment, in the "learning value calculation routine", the EGR control is not executed, the intake pressure deviation .DELTA.PiM is within the predetermined range, and the final throttle instruction value TRTRAT A small change is a condition for learning the throttle learning value TRTSTN. Therefore, the learning value TRTSTN is calculated in a state where the engine 1 is stable, and as a result, controllability in controlling the opening of the throttle valve 23 can be improved.

(D) In addition, in the present embodiment, in the “learning value calculation routine”, the current throttle learning value T
If the absolute value of the value obtained by subtracting the previous learning value TRTSTB from RTSTN is greater than a predetermined value C3, the current throttle learning value TRTSTN is used as the learning value TRT.
When it is set as ST, it is determined that the fluctuation amount is too large, and the value obtained by adding the predetermined value C3 to the previous learning value TRTSTB is set as the final learning value TRTST. Therefore, it is possible to suppress a rapid change in the intake air amount due to the learning value TRTST fluctuating too much. As a result, it is possible to reliably prevent drivability from deteriorating due to a sudden change in the intake air amount.

The present invention is not limited to the above embodiment, and may be configured as follows, for example. (1) In the above embodiment, in the “closed amount calculation routine”, the intake pressure PiM is set to the predetermined value C.
Until the intake pressure PiM becomes equal to or less than a predetermined value C5, the trapping amount TRTC is kept increasing until the intake pressure PiM becomes equal to or less than a predetermined value C5. Feedback control may be performed so that the intake pressure PiM is maintained at or above the predetermined value C6.

This processing will be described with reference to a part of the flowchart of FIG. 9 (“closing amount calculation routine”). If the determination in step 205 is affirmative, the routine proceeds to step 251 and the ECU 30 determines the intake pressure. It is determined whether PiM is equal to or greater than a predetermined value C6 (C6 <C5). When the intake pressure PiM is equal to or higher than the predetermined value C6, it is assumed that the current intake pressure PiM is maintained between the predetermined value C6 and the predetermined value C5, and the closing amount TRTC up to that time is set to a new value. The confinement amount TRTC is set as it is.

On the other hand, when the intake pressure PiM is not equal to or higher than the predetermined value C6, in step 253,
In order to slightly increase the opening degree of the throttle valve 23, a value obtained by subtracting “1” from the previous closing amount TRTC is set as a new closing amount TRTC. As a result, the opening of the throttle valve 23 is gradually increased, and the intake pressure PiM may eventually reach the predetermined value C6 or more.

If a negative determination is made in step 205 (PiM> C5), the same processing as step 207 in the above embodiment is performed. That is, a value obtained by adding “1” to the previous trapping amount TRTC is set as a new trapping amount TRTC.

By performing the above-described feedback control, the intake pressure PiM is equal to or higher than the predetermined value C6, and
It is maintained at or below the predetermined value C5, and the amount of confinement T
It is possible to avoid a problem caused by an excessively large RTC. However, in the above case, similarly to the above-described embodiment, it is desirable that the operation is performed only at the time of idling in which stratified combustion is performed.

(2) In the above embodiment, when it is determined that the engine 1 is in the idling state and the throttle closing execution flag XTRTST is "1", the closing control is executed. Learning was performed based on this. On the other hand, the learning control described below may be performed when it is difficult to close the throttle valve 23 other than during idling. That is, for example, when the EGR control is not executed, the intake pressure deviation ΔPiM is within the predetermined range, and the final throttle instruction value TRTRAT has a small variation, and the condition is satisfied. Calculates the reference opening of the throttle valve 23 based on the intake pressure PiM detected by the intake pressure sensor, and compares the calculated reference opening with the basic instruction value TRTRATM. The correction amount (learning value TRTST) may be calculated based on the comparison result.
No.

(3) In the above embodiment, the throttle valve 23 is applied as the intake air amount control valve. However, a known idle speed control valve (rotary ISCV or stepper ISCV may be used) or the like may be used. It may be used as a control valve. In such a case, the throttle valve 23 may be of a mechanical link type.

Further, in the above-described embodiment, the embodiment is embodied in the case where only one throttle valve 23 is provided. However, the embodiment may be embodied in a type having two valves in series or in parallel.

(4) In the above embodiment, the present invention is embodied in the in-cylinder injection type engine 1. However, any type of internal combustion engine that performs so-called stratified combustion or weakly stratified combustion can be used. It may be embodied in something. For example, a type in which the fuel is injected toward the back side of the cap of the intake valves 6a and 6b of the intake ports 7a and 7b is also included. Although a fuel injection valve is provided on the intake valves 6a and 6b side, a type in which fuel is injected directly into the cylinder bore (combustion chamber 5) is also included.

(5) In the above embodiment, the helical intake port is provided so as to generate a so-called swirl. However, it is not always necessary to generate a swirl. Therefore, for example, the swirl control valve 17, the step motor 19, and the like in the above embodiment can be omitted .

The technical idea which is not described in each claim of the claims but can be grasped from the above embodiment is described below together with its effects. (A) The intake air amount control device for an internal combustion engine according to claim 1 , wherein the intake air amount control valve is an electronically controlled throttle valve, and an idle speed control valve provided in a bypass passage that bypasses the intake passage. And at least one of them.

With the above configuration, the function and effect of the invention described in claim 1 can be further ensured. (B) In the intake air amount control apparatus for an internal combustion engine according to claim 1, the stable state detection means includes:
It is characterized by detecting that the internal combustion engine is in an idling state.

With the above configuration, the first aspect of the present invention
The operation and effect of the invention described in Additional Note (a) can be further ensured. (C) In the intake air amount control device for an internal combustion engine according to claim 1, the internal combustion engine according to the additional notes (a) and (b),
An exhaust gas recirculation device is provided, and the stable state detection means sets the amount of exhaust gas recirculation by the exhaust gas recirculation device to 0 when the internal combustion engine is detected to be in a stable state.

With the above arrangement, an accurate correction amount can be obtained, and controllability can be improved.

[0091]

As described above in detail, according to the intake air amount control apparatus for an internal combustion engine of the present invention, in the intake air amount control apparatus for an internal combustion engine capable of performing stratified combustion, an intake air amount control valve is provided. This has an excellent effect that the deterioration of the combustion state due to the error of the opening degree can be prevented.

[Brief description of the drawings]

FIG. 1 is a basic conceptual configuration diagram of the invention described in claim 1;

FIG. 2 is a schematic configuration showing an intake air amount control device for an engine;
FIG.

FIG. 3 is an enlarged view showing a cylinder portion, a port portion, and the like of the engine .
FIG.

FIG. 4 is a diagram showing a throttle opening setting executed by the ECU .
9 is a flowchart showing a “routine”.

FIG. 5 is a diagram illustrating a “closed amount calculation routine” executed by the ECU.
Is a flowchart illustrating a routine ".

FIG. 6 illustrates a learning value calculation routine executed by the ECU.
Is a flow chart showing a down ".

FIG. 7 is a diagram illustrating a speed determined by an engine speed and an intake pressure.
It is the map which showed the relationship of the Lotle reference opening.

FIG. 8 shows a “count value setting routine” executed by the ECU .
FIG.

FIG. 9 is a diagram illustrating a “closed amount calculation rule” according to another embodiment .
Chin ”is a part of a flowchart.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine as an internal combustion engine, 1a ... Cylinder, 11 ... Fuel injection valve as fuel injection means, 15a ... First intake path constituting an intake passage, 15b ... Second intake path constituting an intake passage, 16 ... Intake Surge tank constituting passage, 20 ...
Intake duct forming an intake passage, 23 ... Throttle valve as intake air amount control valve, 25 ... Throttle sensor forming operating state detecting means, 26A ... Accelerator sensor forming operating state detecting means, 26B ... Operating state detecting means ,
Fully-closed switch constituting stable state detecting means, 27 ... Top dead center sensor constituting operating state detecting means, 28 ... Crank angle sensor constituting operating state detecting means, 29 ... Swirl control valve constituting operating state detecting means Sensor, 30... ECU constituting the intake air amount control means, control valve closing control means, correction amount calculation means, correction control means and reference opening degree calculation means, 61... Constituting the operating state detection means, intake pressure detection means Intake pressure sensor 62, a water temperature sensor that constitutes an operating state detecting means.

Continuation of front page (56) References JP-A-7-119509 (JP, A) JP-A-4-228845 (JP, A) JP-A-7-77100 (JP, A) JP-A-5-321743 (JP) JP-A-5-193393 (JP, A) JP-A-9-203350 (JP, A) JP-A-5-39752 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) F02D 41/00-45/00 395

Claims (1)

(57) [Claims] 1. A fuel injection means for injecting fuel into a cylinder of an internal combustion engine to perform stratified combustion and homogeneous combustion, and an amount of intake air provided in an intake passage of the internal combustion engine and supplied to the cylinder An intake air amount control valve for adjusting the operation amount; an actuator for driving the intake air amount control valve; an operating state detecting means for detecting an operating state of the internal combustion engine; and An intake air amount control means for calculating an opening instruction value of the intake air amount control valve and controlling the actuator based on the opening instruction value to control the intake air amount; In the air amount control device, exhaust gas recirculation by the exhaust gas circulation device of the internal combustion engine is performed.
A stable state detecting means for detecting that the internal combustion engine is in a stable state , including a condition that the loop is not performed; an intake pressure detecting means for detecting an intake pressure in the intake passage; and the stable state detecting means When it is detected that the internal combustion engine is in a stable state, a reference opening calculating means for calculating a reference opening of the intake air amount control valve based on the intake pressure detected by the intake pressure detecting means, A correction amount calculation for comparing a reference opening calculated by the reference opening calculation means with an opening of the intake air amount control valve based on the opening instruction value, and calculating a correction amount based on the comparison result. Means, and a correction control means for correcting the opening instruction value based on the correction amount calculated by the correction amount calculation means during control by the intake air amount control means. Internal combustion Engine air intake control device.