JPH07103017A - In-cylinder injection type spark ignition engine - Google Patents

Abstract

PURPOSE:To carry out in-cylinder injection to achieve desired air fuel ratio even when the step-on amount of acceleration pedal is rapidly changed at least in a drive region in which in-cylinder injection is to be carried out, in an in- cylinder injection type spark ignition engine. CONSTITUTION:An in-cylinder injection type spark ignition engine is provided with a fuel injection valve 7 for directly injection fuel into a cylinder, a throttle valve 9, a first decision means for deciding an aimed throttle valve opening corresponding to an engine drive condition, and a first driving means 10 for driving the throttle valve 9 so that the aimed throttle valve opening determined by the first decision means is achieved. A detection means 21 for detecting a step-on variation amount of acceleration pedal is also provided, and when the step-on variation amount of acceleration pedal detected by a detection means 20 in a drive region in which the fuel injection valve 7 is used, is greater than a specific value, the aimed throttle valve opening determined by the first decision means is corrected to the side where the intake air amount needed at the time is easily provided, for a specific period of time thereafter by a first correction means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-cylinder injection type spark ignition engine in which fuel is directly injected into a cylinder at least in a specific operation region, and an air-fuel mixture formed thereby is ignited and burned by a spark plug.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 2-115542 has a first injection valve for injecting fuel directly into a cylinder and a second injection valve for injecting fuel into an intake passage. In the internal combustion engine that executes the low fuel consumption stratified charge combustion by using the first injection valve, and mainly executes the high output uniform combustion by using the second injection valve when the engine is under high load, when the fuel cut is restored. An internal combustion engine that mainly uses the second injection valve even in a low load operation state is described.

The fuel injection using the second injection valve in the low load operation state when the fuel cut is restored does not atomize with the fuel injected from the first injection valve when the temperature in the combustion chamber is low. Also, it is intended to prevent the fuel from being vaporized in the first injection valve and the desired amount of fuel not being supplied when the temperature in the combustion chamber is high.

[0004]

Generally, when the accelerator pedal is suddenly depressed, such as when the fuel cut is forcibly returned or when the engine is suddenly accelerated, the intake air amount is reduced even if the throttle valve reaches a desired opening degree. Following this, it does not increase instantaneously and a considerable response delay occurs. On the other hand, in the injection valve that directly injects fuel into the cylinder, the injected fuel does not adhere to the wall surface of the intake passage or the like, so that the fuel amount according to the engine operating state is reliably supplied into the combustion chamber. As a result, in the operating region in which the in-cylinder injection is executed, the air-fuel ratio of the air-fuel mixture formed during the fuel cut forced recovery and during the rapid engine acceleration is considerably richer than the target value, and smoke is generated. On the contrary, when the engine decelerates suddenly, it will be on the rather lean side, which may cause a misfire.

In the above-mentioned prior art, since the second injection valve that accompanies fuel adhesion to the wall surface of the intake passage is used when the fuel cut is restored, as a result, the air-fuel ratio of the air-fuel mixture formed at this time is not so rich. However, the occurrence of smoke is prevented, but when the engine load is low, stratified charge combustion is not executed and fuel consumption deteriorates. Further, it is still impossible to prevent the generation of smoke during sudden acceleration of the engine and the occurrence of misfire during sudden deceleration of the engine.

Therefore, an object of the present invention is to provide a cylinder injection type spark ignition engine in which cylinder injection is executed at least in a specific operation region, and in this operation region, even when the depression amount of the accelerator pedal changes abruptly. An object of the present invention is to provide a cylinder injection type spark ignition engine capable of executing internal injection to realize a desired air-fuel ratio.

[0007]

A cylinder injection type spark ignition engine according to the present invention includes a fuel injection valve for directly injecting fuel into a cylinder, an exhaust passage, an intake passage, and the intake passage. A throttle valve, a first determining means for determining a target throttle valve opening degree according to an engine operating state, and a first driving means for driving the throttle valve so that the target throttle valve opening degree is determined by the first determining means. When the driving means, the detecting means for detecting the depression change amount of the accelerator pedal, and the depression change amount of the accelerator pedal detected by the detecting means in the operating region where the fuel injection valve is used are equal to or more than a predetermined value, For a predetermined period of time, a first correcting means for correcting the target throttle valve opening determined by the first determining means to a side where the required intake air amount at this time is easily obtained. And wherein the Rukoto.

[0008]

This cylinder injection type spark ignition engine includes a fuel injection valve for directly injecting fuel into the cylinder and a throttle valve, and the first determining means sets the target throttle valve opening degree according to the engine operating state. Then, the driving means drives the throttle valve so that the target throttle valve opening determined by the first determining means is reached, and the detecting means detects the depression change amount of the accelerator pedal. When the amount of depression change of the accelerator pedal detected by the detection means is equal to or more than a predetermined value in the operating region, the first correction means sets the target throttle valve opening determined by the first determination means for a predetermined time thereafter. Correct to the side that makes it easier to obtain the required intake amount.

[0009]

1 is a schematic sectional view of a cylinder injection type spark ignition engine according to the present invention. In the figure, 1 is a combustion chamber, 2
Is a piston, 3 is an intake passage communicating with the combustion chamber 1 via an intake valve 4, and 5 is an exhaust passage communicating with the combustion chamber 1 via an exhaust valve 6. Reference numeral 7 denotes a fuel injection valve for injecting fuel directly into the combustion chamber 1. The fuel injection valve 7 performs fuel injection at the end of the compression stroke so that fuel-efficient stratified combustion is performed in each operating region. It has become. 8 is a spark plug.

A throttle valve 9 is arranged in the intake passage 3, and the throttle valve 9 is an accelerator pedal (not shown).
It is not interlocked with, but is independently driven by the first drive device 10 such as a step motor. The downstream side of the throttle valve 9 of the intake passage 3 and the exhaust passage 5 are connected by an exhaust gas recirculation passage 11, and a control valve 12 for controlling the amount of exhaust gas to be circulated is provided in the exhaust gas recirculation passage 11. It is arranged. 13 is this control valve 12
Is a second drive device such as a step motor for driving the.

Reference numeral 20 denotes a fuel injection amount control via the fuel injection valve 7, an opening control of the throttle valve 9 via the first drive device 10, and a control valve 12 via the second drive device 13.
Of the accelerator pedal stroke sensor 21 for detecting the amount of depression of the accelerator pedal as the engine load, the rotation sensor 22 for detecting the engine speed, and the cooling water temperature as the engine temperature. Sensors for determining the engine operating state such as the cooling water temperature sensor 23 to be detected are connected.

The opening control of the throttle valve 9 is executed according to the first flow chart shown in FIG. This flow chart is executed at the same time when the engine is started and is repeated every engine revolution. First, at step 101, the accelerator pedal stroke sensor 21 detects the current accelerator pedal depression amount L1. Next, at step 102, the target throttle valve opening degree θ1 is determined by the solid line of the first map shown in FIG. 5 based on the depression amount L1 corresponding to the engine load.

Next, at step 103, it is judged if a first count value na, which will be described later, is zero.
Initially, this judgment is affirmed and the routine proceeds to step 104, where it is judged whether the similar second count value nb is 0 or not. Initially, this judgment is also affirmed, and the routine proceeds to step 105.

At step 105, it is judged whether or not the difference between the current accelerator pedal depression amount L1 and the previous accelerator pedal depression amount L0 is equal to or more than a predetermined value α, and when the determination is negative, the routine proceeds to step 106, It is determined whether the difference between the previous depression amount L0 and the current depression amount L1 is equal to or larger than a predetermined value β.

When this determination is denied, that is, when the amount of change in the depression of the accelerator pedal is relatively small, the amount of change in the opening of the throttle valve 9 associated therewith is also small, and at this time a desired amount of intake air is introduced into the combustion chamber 1. In order to be supplied, the target throttle valve opening θ1 determined in step 102
Does not need to be corrected. In step 107, the actual opening θ1 ′ of the throttle valve 9 is set to this opening θ1, and in step 108, the actual opening θ1 ′ is realized so that the actual opening θ1 ′ is realized. 10 is activated. At this time, the guard processing is executed so that the actual opening θ1 ′ does not exceed 100% and does not fall below the minimum opening during idling. Next, the routine proceeds to step 109, where the current accelerator pedal depression amount L1 is set as the previous depression amount L0.

On the other hand, when the determination at step 105 is affirmative, that is, at the time of sudden acceleration of the engine in which the amount of depression of the accelerator pedal is large or when the fuel cut is forcibly restored, the routine proceeds to step 110, where it is initially reset to 0. The count value na is incremented by 1. Next, the routine proceeds to step 111, where the target throttle valve opening degree θ1 determined at step 102 is corrected by being multiplied by a coefficient KANA corresponding to the count value na at this time.

Next, at step 112, it is judged whether or not the first count value na has reached the predetermined value MA, and this judgment is initially denied and the routine proceeds to step 107,
The actual opening θ1 ′ of the throttle valve 9 is set to the opening θ1 corrected in step 111. Step 11 once
When 0 is passed, the determination of step 103 is denied in the next processing, the processing of step 110 and after is forcibly executed, the determination of step 112 is affirmed, and the first count value na is reset to 0 in step 113. Until MA, that is, MA times are repeated.

The above-mentioned coefficient KAn is a value larger than 1 as shown in the second map of FIG. 6, and according to the above-described flow, the opening degree of the throttle valve 9 at the time of sudden acceleration of the engine or at the forced return of the fuel cut. As shown in the time chart of FIG. 8, the target throttle valve opening given in accordance with the engine load is increased for a predetermined time (execution interval * MA of the flowchart) from time t1, and the increase rate is gradually increased. After being made larger, it is gradually made smaller. Therefore, the response delay of the increase in the intake air amount that occurs at this time is mitigated by opening the throttle valve 9 more than the target, so that the air-fuel mixture mixture becomes richer than the target value due to insufficient intake air. Therefore, the desired air-fuel ratio can be realized. Further, in particular, after the lapse of a predetermined time, since the target throttle valve opening corresponding to the engine load at this time is gradually returned, the intake air amount is suddenly reduced at this time and torque shock is not generated. Absent.

On the other hand, when the determination in step 106 is affirmative, that is, when the accelerator pedal decelerates with a large accelerator pedal depression change amount, the routine proceeds to step 114, where the second count value nb, which is initially reset to 0, increases by 1. To be done. Next, the procedure proceeds to step 115 and step 102
The target throttle valve opening .theta.1 determined in step 1 is corrected by being multiplied by a coefficient KBnb corresponding to the count value nb at this time. Next, the routine proceeds to step 116, where the second count value na
Is judged to have reached the predetermined value MB, and this judgment is initially denied and the routine proceeds to step 107, where the actual opening θ1 ′ of the throttle valve 9 is made the opening θ1 corrected in step 115. Once step 114 is passed, the determination of step 104 is denied in the next processing, and the processing of step 114 and thereafter is forcibly executed.
If the determination in step 117 is affirmative, step 11
In step 7, the second count value nb is reset to 0, that is, MB times are repeated.

The above-mentioned coefficient KBnb is a positive number smaller than 1 as shown in the third map of FIG. 7, and according to the flow described above, the opening degree of the throttle valve 9 is shown in FIG. 8 during the rapid deceleration of the engine. As shown in the time chart, during a predetermined time (execution interval * MB of the flowchart) from time t2,
The target throttle valve opening degree given according to the engine load is reduced, and this reduction rate is gradually increased and then gradually decreased. Therefore, the response delay of the reduction of the intake air amount that occurs at this time is mitigated by closing the throttle valve 9 more than the target, so that the air-fuel mixture mixture is prevented from becoming leaner than the target value due to excessive intake. Thus, a desired air-fuel ratio can be realized. Further, in particular, after the lapse of a predetermined time, since the target throttle valve opening corresponding to the engine load at this time is gradually returned, the intake air amount suddenly increases at this time and torque shock is not generated. Absent.

As described above, when the accelerator pedal depression change amount is equal to or greater than the predetermined value, the target throttle valve opening determined in accordance with the engine load is increased by the accelerator pedal depression amount for a predetermined time thereafter. Sometimes it is corrected to the increase side, and when the accelerator pedal depression amount is decreased, it is corrected to the decrease side, that is, with respect to the intake delay at this time,
Since the target throttle valve opening is corrected to the side where the required intake amount is easily obtained, it is possible to prevent a desired air-fuel ratio from being realized due to excess or deficiency of the intake amount, and prevent misfire and smoke from occurring.

The opening control of the control valve 11 is executed according to the second flow chart shown in FIG. This flowchart is also executed at the same time as the engine is started, and is repeated for each revolution of the engine. First in step 201,
The accelerator pedal stroke sensor 21 detects the current depression amount L1 of the accelerator pedal. Next, at step 202, the target control valve opening degree θ2 is determined by the dotted line of the first map shown in FIG. 5 based on the depression amount L1 corresponding to the engine load.

The basic concept of the following processing is the above-mentioned first method.
It is similar to the flowchart, and only the differences will be described. Similarly to the above, in step 206, it is determined whether or not the difference between the current accelerator pedal depression amount L1 and the previous accelerator pedal depression amount L0 is a predetermined value α or more. It is determined whether the accelerator pedal depression amount L1 is less than or equal to the set value A. When this determination is affirmative, that is, when the engine load is low, the process proceeds to step 207 without performing the determination in step 206, and whether the difference between the previous depression amount L0 and the current depression amount L1 is the predetermined value β or more. It will be judged.

When this determination is denied, that is, when the amount of change in the depression of the accelerator pedal is relatively small, the amount of change in the opening of the throttle valve 9 associated therewith is also small. At this time, a desired amount of intake air is introduced into the combustion chamber 1. In order to be supplied, the target control valve opening degree θ2 determined in step 202 does not need to be corrected, and the actual opening degree θ2 ′ of the control valve 12 is set to this opening degree θ2 in step 208.
At 9, the second drive device 13 is operated so that the actual opening θ2 ′ is realized. At this time, the actual opening θ
Guard processing is executed so that 2'does not exceed 100%.

When the determination at step 206 is affirmative, that is, when the accelerator pedal is greatly accelerated and the engine is suddenly accelerated or the fuel cut is forcibly restored, the processing from step 211 onward is executed. In this process, the basic control valve opening degree θ2 determined in step 202 is corrected by multiplying it by the coefficient KCnc corresponding to the count value nc at this time. Since this coefficient KCnc is a positive number smaller than 1 showing the same tendency as the above-mentioned coefficient KBnb, at this time, the opening degree of the control valve 12 is from the time t1 as shown in the time chart of FIG. The target control valve opening given according to the engine load is reduced for a predetermined time (execution interval * MC of the flowchart), and the reduction rate is gradually increased and then gradually decreased. . Therefore, the response delay of the increase of the intake air amount that occurs at this time is mitigated because the intake air easily flows into the combustion chamber 1 by reducing the amount of exhaust gas to be recirculated, and thus the air-fuel ratio of the air-fuel mixture becomes insufficient due to insufficient intake air. Is prevented from becoming richer than the target value, and a desired air-fuel ratio can be realized. Also, especially after the lapse of a predetermined time, since the target control valve opening corresponding to the engine load at this time is gradually returned, the recirculated exhaust gas amount rapidly increases at this time and torque shock occurs. There is nothing to do.

On the other hand, when the determination in step 207 is affirmative, that is, when the engine deceleration in which the amount of depression of the accelerator pedal is large is large, the processing from step 215 is executed. In this processing, the target control valve opening degree θ2 determined in step 202 is corrected by being multiplied by the coefficient KDnd corresponding to the count value nd at this time. This coefficient KD
Since nd is a value larger than 1 showing the same tendency as the coefficient Kana described above, at this time, the opening degree of the control valve 12 is
As shown in the time chart of FIG. 9, the target control valve opening degree that is given according to the engine load is increased for a predetermined time (execution interval * MD of the flowchart) from time t2, and this increase rate is gradually increased. After that, the size is gradually reduced. Therefore, the response delay of the decrease in the intake air amount that occurs at this time is mitigated because the intake air is less likely to flow into the combustion chamber 1 by increasing the amount of exhaust gas to be recirculated. Is prevented from becoming leaner than the target value, and a desired air-fuel ratio can be realized. Also, especially after a lapse of a predetermined time, since the basic control valve opening degree corresponding to the engine load at this time is gradually returned, the recirculated exhaust gas amount sharply decreases at this time and torque shock occurs. There is nothing to do.

As described above, when the accelerator pedal depression change amount is equal to or greater than the predetermined value, the target control valve opening determined according to the engine load is
When the accelerator pedal depression amount is increased, it is corrected to the decreasing side, and when the accelerator pedal depression amount is decreased, it is corrected to the increasing side.In other words, the target control valve opening changes the recirculated exhaust gas amount with respect to the intake delay at this time. Since it is corrected to the side where the required intake amount is easily obtained by changing,
A desired air-fuel ratio cannot be realized due to excess or deficiency of the intake air amount, and misfire and smoke are prevented from occurring. However,
The judgment of step 205 is provided, and when the engine load is low, the correction for reducing the target opening degree after step 211 is not performed. This is because the degree of negative pressure in the intake passage 3 is large when the engine load is low, and if the control valve 11 is closed above the target at this time, a large pumping loss occurs and the output decreases. .

The fuel injection amount control is executed according to the third flow chart shown in FIG. This flowchart is also executed at the same time as the engine is started, and is repeated for each revolution of the engine. First, in step 301, the accelerator pedal stroke sensor 21 detects the current accelerator pedal depression amount L1 and the rotation sensor 22 determines the engine speed N.
Is detected. Next, at step 302, the target fuel injection amount Q is determined based on the depression amount L1 corresponding to the engine load and the engine speed N.

The basic concept of the following processing is the above-mentioned second method.
It is similar to the flowchart, and only the differences will be described. Similarly to the above, in step 306, it is determined whether or not the difference between the current accelerator pedal depression amount L1 and the previous accelerator pedal depression amount L0 is greater than or equal to a predetermined value α, and when this determination is negative, the routine proceeds to step 307, where It is determined whether the difference between the depression amount L0 and the depression amount L1 of this time is equal to or more than the predetermined value β.

When this determination is denied, that is, when the amount of change in the depression of the accelerator pedal is relatively small, the amount of change in the opening of the throttle valve 9 associated therewith is also small, and at this time a desired amount of intake air is introduced into the combustion chamber 1. In order to be supplied, the target fuel injection amount Q determined in step 302 does not need to be corrected, and in step 308, the actual fuel injection amount Q ′ is set to this target fuel injection amount Q, and step 309
At, the fuel injection is executed based on the fuel injection amount Q ′.

When the determination in step 306 is affirmative, that is, when the engine is rapidly accelerated with a large accelerator pedal depression change amount or when the fuel cut is forcibly restored, the processing from step 311 is executed. In this process, the target fuel injection amount Q determined in step 302 is multiplied by the coefficient KEne corresponding to the count value ne at this time and corrected. Since this coefficient KEne is a positive number smaller than 1 showing the same tendency as the coefficient KEnb described above, at this time,
As for the actual fuel injection amount, as shown in the time chart of FIG. 10, the target fuel injection amount given according to the engine operating state is reduced for a predetermined time (execution interval * ME of the flowchart) from time t1. The rate of decrease is gradually increased and then gradually decreased. Therefore, for the response delay of the intake amount increase that occurs at this time,
Since the fuel injection amount is reduced, the air-fuel mixture mixture is prevented from becoming richer than the target value, and a desired air-fuel ratio can be realized. Further, in particular, after the lapse of a predetermined time, since the target fuel injection amount is gradually returned to the target fuel injection amount corresponding to the engine operating state at this time, the fuel injection amount suddenly increases at this time and torque shock occurs. There is no.

On the other hand, when the determination in step 307 is affirmative, that is, when the engine deceleration in which the accelerator pedal depression change amount is large, the processing from step 315 is executed. In this process, the target fuel injection amount Q determined in step 302 is multiplied by the coefficient KFnf corresponding to the count value nf at this time and corrected. This coefficient KFnf
Is a value larger than 1 which shows the same tendency as the above-mentioned coefficient Kana, so that at this time, the actual fuel injection amount Q '
As shown in the time chart of FIG. 10, the target fuel injection amount given according to the engine operating state is increased during a predetermined time (execution interval * MF of the flowchart) from time t2, and the increase rate is gradually increased. After being made larger, it is gradually made smaller. Therefore, since the fuel injection amount is increased with respect to the response delay of the decrease in the intake air amount that occurs at this time, the air-fuel ratio of the air-fuel mixture is prevented from becoming leaner than the target value, and the desired air-fuel ratio is realized. be able to. In addition, in particular, after the lapse of a predetermined time, the target fuel injection amount corresponding to the engine load at this time is gradually returned to the target fuel injection amount. Therefore, at this time, the fuel injection amount sharply decreases and torque shock is not generated. Absent.

As described above, when the accelerator pedal depression change amount is equal to or greater than the predetermined value, the target fuel injection amount determined according to the engine load and the rotational speed is the accelerator pedal depression amount for a predetermined time thereafter. Is corrected to a decrease side when the accelerator pedal is increased, and is increased to a decrease when the accelerator pedal depression amount is decreased, that is, the fuel injection amount is made closer to a desired air fuel ratio at this time with respect to the intake delay at this time. Due to the side-to-side correction, the occurrence of misfires and misfires and smokes is prevented. However, step 3
The determination of 05 is provided, and when the engine load is low, the correction for reducing the target fuel injection amount after step 311 is not performed. This is because the target fuel injection amount is small when the engine load is low, and if the target fuel injection amount is reduced, misfire may occur.

In this embodiment, predetermined values MA, MB, MC, MD, ME, MF for determining the increase / decrease correction time for each control.
Is set to a value suitable for each increase / decrease correction, and it is also possible to use these as variables according to the amount of depression change of the accelerator pedal. In addition, each increase correction coefficient Kana, KDnd, K
Fnf can be set to a fixed optimum value larger than 1, and each of the reduction correction coefficients KBnb, KCnc, and KEne can be set to a fixed optimum value smaller than 1.

This embodiment has shown the in-cylinder injection spark ignition engine having only the fuel injection valve 7 for injecting fuel into the cylinder. For example, another fuel injection valve for further injecting fuel into the intake passage. Even in the internal combustion engine having, by performing the above-mentioned control in the operating region where in-cylinder injection is executed,
A desired air-fuel ratio can be realized when the depression amount of the accelerator pedal changes rapidly without stopping the in-cylinder injection.

In the present embodiment, the above-mentioned three controls are executed at the same time, but this does not limit the present invention. Any one may execute only one or two, and the other control may be a normal control. However, the desired air-fuel ratio can be realized relatively well. However, in the throttle valve opening control, the target throttle valve opening is already fully opened, that is, 100% at the time of high engine load, and at this time, increase correction cannot be performed, and at the time of low engine load, When the target throttle valve opening is near the idle opening, reduction correction cannot be performed. Further, as described above, when the engine load is low, it is not preferable to correct the decrease of the control valve opening and the fuel injection amount, and the exhaust gas recirculation is accompanied by some combustion deterioration. Since the control valve 12 is fully closed at this time,
No increase or decrease corrections can be made. in this way,
Each control has an uncorrectable operating region, and it is preferable to execute at least two of the above-mentioned three controls in combination so that such an operating region does not exist.

[0037]

As described above, according to the first in-cylinder injection spark ignition engine of the present invention, the fuel injection valve for directly injecting fuel into the cylinder, the exhaust passage, the intake passage, and the intake passage The throttle valve disposed at the first position, the first determining means for determining the target throttle valve opening degree according to the engine operating state, and the throttle valve is driven so as to reach the target throttle valve opening degree determined by the first determining means. A first drive means and a detection means for detecting an accelerator pedal depression change amount are provided, and the accelerator pedal depression change amount detected by the detection means is equal to or more than a predetermined value in an operating region in which the fuel injection valve is used. At a certain time, the target throttle valve opening determined by the determining means for the subsequent predetermined time is corrected to the side that makes it easier to obtain the required intake air amount at this time.
It is possible to prevent a desired air-fuel ratio from being realized due to an excess or deficiency of the intake air amount due to a delay in the intake air increase / decrease, and to prevent misfire and smoke.

Further, according to the second in-cylinder injection spark ignition engine of the present invention, in the above-mentioned first in-cylinder injection spark ignition engine, the exhaust gas re-establishment for connecting the exhaust passage and the intake passage is further improved. A circulation passage, a control valve arranged in the exhaust gas recirculation passage, second determining means for determining a target control valve opening degree according to an engine operating state, and target control valve opening determined by the second determining means. A second drive means for driving the control valve so that the fuel injection valve is operated at a predetermined speed, and when the accelerator pedal depression change amount detected by the detection means in the operating region where the fuel injection valve is used is a predetermined value or more, The target control valve opening, which is determined by the second determining means for a predetermined time thereafter, is corrected so that the required intake air amount at this time is easily obtained. Never do It is possible to realize the air-fuel ratio of Nozomu.

According to the third in-cylinder injection type spark ignition engine of the present invention, in the above-described first in-cylinder injection type spark ignition engine, the target fuel injection amount is further determined according to the engine operating state. And a control means for controlling the fuel injection valve so that the target fuel injection amount is determined by the third determination means. The detection means is used in the operating region where the fuel injection valve is used. When the detected amount of change in accelerator pedal depression is equal to or greater than a predetermined value, the target fuel injection amount determined by the third determining means for a predetermined time thereafter is such that the air-fuel ratio at this time is close to the desired air-fuel ratio. As a result, the desired air-fuel ratio can be realized even if the intake air amount becomes excessive or insufficient due to the intake air intake delay.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a direct injection spark ignition engine according to the present invention.

FIG. 2 is a first flowchart for controlling the opening of a throttle valve.

FIG. 3 is a second flowchart for controlling the opening of the control valve.

FIG. 4 is a third flowchart for controlling the fuel injection amount.

FIG. 5 is a first map for determining target opening amounts of a throttle valve and a control valve.

FIG. 6 is a second map for determining the coefficient KAna used in the first flowchart.

FIG. 7 is a third map for determining the coefficient KBnb used in the first flowchart.

FIG. 8 is a time chart showing an actual throttle valve opening.

FIG. 9 is a time chart showing an actual control valve opening.

FIG. 10 is a time chart showing an actual fuel injection amount.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Combustion chamber 3 ... Intake passage 5 ... Exhaust passage 7 ... Fuel injection valve 8 ... Spark plug 9 ... Throttle valve 10 ... First drive device 11 ... Exhaust gas recirculation passage 12 ... Control valve 13 ... Second drive device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location F02D 41/14 320 C 8011-3G 45/00 364 H F02M 25/07 550 FR

Claims (3)

[Claims] 1. A fuel injection valve for directly injecting fuel into a cylinder, an exhaust passage, an intake passage, a throttle valve arranged in the intake passage, and a target throttle valve opening degree according to an engine operating state. First determining means for determining, first driving means for driving the throttle valve so as to reach the target throttle valve opening determined by the first determining means, and detecting means for detecting the amount of depression change of the accelerator pedal. The target throttle determined by the first determining means for a predetermined time thereafter when the accelerator pedal depression change amount detected by the detecting means is equal to or more than a predetermined value in the operating region in which the fuel injection valve is used. A cylinder injection type spark ignition engine, comprising: a first correction means for correcting the valve opening so that a required intake amount at this time is easily obtained. 2. An exhaust gas recirculation passage communicating between the exhaust passage and the intake passage, a control valve arranged in the exhaust gas recirculation passage, and a target control valve opening according to an engine operating state. Degree determining means, second drive means for driving the control valve so as to reach the target control valve opening degree determined by the second determining means, and an operating region in which the fuel injection valve is used. When the amount of depression change of the accelerator pedal detected by the detecting means is equal to or more than a predetermined value, the target control valve opening determined by the second determining means is set to the target intake air amount at this time for a predetermined time thereafter. The in-cylinder injection spark ignition engine according to claim 1, further comprising: a second correction unit that corrects to a side that facilitates obtaining. 3. A third determining means for determining a target fuel injection amount according to an engine operating condition, and the fuel injection valve is controlled so that the target fuel injection amount is determined by the third determining means. When the depression amount of the accelerator pedal detected by the detection means in the operating region where the control means and the fuel injection valve are used is a predetermined value or more,
And a third correction unit that corrects the target fuel injection amount determined by the third determination unit to a side where the air-fuel ratio at this time approaches a desired air-fuel ratio for a predetermined time thereafter. The cylinder injection type spark ignition engine according to claim 1.