JP3928198B2 - Engine control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combustion state control means for setting a combustion state to one of a stratified combustion mode and a uniform combustion mode according to an operating state of the engine, and a fuel that controls to cut fuel when the engine is in a specific operating state. The present invention relates to an engine control device having a cutting means.
[0002]
[Prior art]
Conventionally, as shown in, for example, Japanese Patent Laid-Open No. 7-279729, in an in-cylinder injection fuel control apparatus for an internal combustion engine that directly injects fuel into a cylinder and burns the fuel, compression is performed according to the operating state of the internal combustion engine. Fuel injection switching means for injecting fuel by switching the injection method to stroke injection or intake stroke injection, fuel cut means for determining the fuel cut state according to the operating state and executing fuel cut, and predetermined after returning from the fuel cut state An injection method fixing means for fixing the injection method to one of the compression stroke injection and the intake stroke injection when the condition is satisfied is provided to prevent the switching of the fuel injection method when returning from the fuel cut state to the driver. Reducing shock is being done.
[0003]
[Problems to be solved by the invention]
In the control device described in the above publication, when the fuel cut is performed by the fuel cut means to stop the fuel injection, if the engine speed decreases and the condition for stopping the fuel cut is satisfied, the injection method is compressed. Since it is configured to be fixed to one of the stroke injection and the intake stroke injection, when it is fixed to the compression stroke injection, the amount of intake air supplied to the combustion chamber of the engine is insufficient and the engine is likely to misfire. There's a problem.
[0004]
That is, in a stratified charge combustion engine that performs lean burn combustion with an air-fuel ratio of about 40 to 140, the catalyst temperature of the exhaust purification device is reduced due to the fact that intake air having a low temperature is supplied to the exhaust passage during the fuel cut. In order to prevent a decrease, the intake air amount adjusting means including an electric throttle or the like is configured to be in a closed state. When the fuel cut is completed and the fuel injection is resumed, the engine operating state is normally in a low load state. Therefore, the compression stroke injection is performed to change the engine combustion state to the stratified combustion mode. However, it is inevitable that a response delay will occur in the intake air supply even if the intake air amount adjusting means is opened at the same time as the fuel injection is restarted. There was a problem that misfiring was likely to occur due to the over-rich state of the fuel around the spark plug and the ignition plug being delayed.
[0005]
In view of such circumstances, the present invention is an engine control device that can effectively prevent the engine from misfiring when the fuel cut control by the fuel cut means is terminated and the fuel injection is restarted. The purpose is to provide.
[0006]
[Means for Solving the Problems]
The invention according to claim 1 is a combustion state control means for setting the combustion state to one of the stratified combustion mode or the uniform combustion mode according to the operation state of the engine, and to cut the fuel when the engine is in the specific operation state. An intake air amount adjusting means for adjusting an intake air passage area provided in an intake passage of the engine, and when the fuel cut control is performed by the fuel cut means. While making the adjustment means substantially fully closed, Fuel injection resumes Above fuel Fee An intake air amount control means for controlling the intake air amount by opening the intake air amount adjusting means at the end of the cut control, and the fuel cut control by the fuel cut means From the end of Set the stratified combustion mode for a certain period of time. Ban Thus, the combustion state of the engine is controlled so that the combustion state is in the uniform combustion mode.
[0007]
According to this configuration, during normal operation of the engine, when the combustion state of the engine is set to one of the stratified combustion mode or the uniform combustion mode by the combustion state control means, and the engine is in a specific operation state, the intake air amount adjusting means As a result, the intake air amount adjusting means is brought into a substantially fully closed state, that is, a fully closed state or a state close to a fully closed state, and fuel cut control for stopping fuel injection by the fuel cut means is executed. Then, when the fuel cut control is executed, when the condition for terminating the fuel cut control is satisfied, the intake air amount adjusting means is opened, and the fuel injection is restarted, so that the intake air intake amount is sucked into the combustion chamber. Thus, the combustion control in the uniform combustion mode is executed over a certain time in consideration of the delay time.
[0008]
The invention according to claim 2 is the engine control device according to claim 1, wherein the fuel injection valve is disposed in a combustion chamber of the engine. By injecting fuel from the fuel injection valve in the compression stroke of the engine, The engine combustion state is set to the stratified combustion mode.
[0009]
According to this configuration, when the combustion state of the engine is set to the stratified combustion mode by the combustion state control means according to the operating state of the engine, the fuel is directly supplied from the fuel injection valve to the combustion chamber during the compression stroke of the engine. By being injected, the entire combustion chamber is in a lean state of the fuel, and the vicinity of the spark plug is partially in a fuel-rich state so that the combustion control in the stratified combustion mode is properly executed. It will be.
[0010]
The invention according to claim 3 is the engine control apparatus according to claim 2, wherein the combustion state of the engine is set to the uniform combustion mode by injecting fuel from the fuel injection valve in the intake stroke of the engine. It is.
[0011]
According to this configuration, when the combustion state of the engine is set to the uniform combustion mode by the combustion state control unit according to the operating state of the engine, or when the fuel cut control is terminated, By directly injecting the fuel from the fuel injection valve into the combustion chamber during the intake stroke, the combustion control in the uniform combustion mode for uniformly dispersing and equalizing the fuel in the combustion chamber is properly executed.
[0012]
According to a fourth aspect of the present invention, in the engine control apparatus according to the second aspect, the combustion state of the engine is set to a uniform combustion mode by injecting fuel from the fuel injection valve in both the intake stroke and the compression stroke of the engine. It is comprised so that it may do.
[0013]
According to this configuration, when the combustion state of the engine is set to the uniform combustion mode by the combustion state control unit according to the operating state of the engine, or when the fuel cut control is terminated, A part of the fuel is injected into the combustion chamber from the fuel injection valve in the intake stroke, and the remaining fuel is injected in the compression stroke of the engine.
[0014]
The invention according to claim 5 is configured such that in the engine according to claim 1, the combustion state of the engine is set to a uniform combustion mode by injecting fuel from the fuel injection valve in a stroke other than the compression stroke of the engine. Is.
[0015]
According to this configuration, when the combustion state of the engine is set to the uniform combustion mode by the combustion state control unit according to the operating state of the engine, or when the fuel cut control is terminated, In the uniform combustion mode, the fuel is uniformly distributed and uniformly distributed in the combustion chamber by injecting fuel from the fuel injection valve disposed in the intake port or the like into the exhaust stroke of the engine or the first half of the intake stroke. Combustion control is properly executed.
[0016]
The invention according to claim 6 is the engine control device according to any one of claims 1 to 5, wherein the fuel injection valve is disposed in the combustion chamber, and the intake air amount adjusting means is disposed upstream of the collecting portion of the intake passage. Is provided.
[0017]
According to this configuration, when the fuel cut control by the fuel cut means is completed and fuel injection is resumed, the intake air amount adjusting means disposed upstream of the collecting portion of the intake passage is opened. As a result, the intake air is supplied into the combustion chamber through the intake passage.
[0018]
The invention according to claim 7 is the engine control device according to any one of claims 1 to 6, further comprising swirl generation means, wherein the swirl generation means is provided when the combustion state of the engine is set to the stratified combustion mode. It is configured to operate.
[0019]
According to this configuration, when the combustion state of the engine is set to the stratified combustion mode by the combustion state control means according to the operating state of the engine, the swirl generating means is operated, and the swirl is formed in the combustion chamber. The combustion control in the stratified combustion mode is appropriately executed.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment of an engine control apparatus according to the present invention. The engine main body 10 has one or a plurality of cylinders 12, and a piston 14 is loaded in the cylinder 12, and a combustion chamber 16 is formed above the piston 14. The combustion chamber 16 is formed with two intake ports and an exhaust port, and each intake port and exhaust port are opened and closed by an intake valve 17 and an exhaust valve 18, respectively.
[0021]
A spark plug 20 is disposed at the top of the combustion chamber 16, and the tip of the spark plug 20 faces the combustion chamber 16. Further, the front end portion of the fuel injection valve 22 faces the combustion chamber 16 from the side, and the fuel is directly injected into the combustion chamber 16 from the fuel injection valve 22. The fuel injection may be a type in which fuel is directly injected onto the upper surface of the piston and fuel is bounced back to the spark plug. The fuel injection valve 22 includes a needle valve and a solenoid (not shown), and when a pulse signal is input to the solenoid, an amount of fuel corresponding to the pulse width is injected at a timing corresponding to the pulse input timing. It is configured as follows.
[0022]
An intake passage 24 is connected to the intake port. In the intake passage 24, an air cleaner 25, an air flow sensor 26, an electric throttle 28, and a surge tank 30 are provided in this order from the upstream side. The downstream passage of the surge tank 30 branches into two corresponding to each intake port, and a swirl control valve 32 is provided in one of the branch passages. The branch passage is opened and closed by the swirl control valve 32, and at least during the combustion control in the stratified combustion mode, which will be described later, the swirl control valve 32 is fully closed or close to the fully closed state. A swirl is generated inside. Further, an exhaust passage 34 is provided in the exhaust port, and exhaust purification devices 35 and 36 having a predetermined three-way catalyst and a lean NOx purification catalyst are disposed in the middle of the exhaust passage 34. These exhaust purification devices 35 and 36 are usually provided in the vicinity of an exhaust manifold having a relatively high exhaust gas temperature.
[0023]
In addition to the air flow sensor 26, the engine is equipped with sensors such as an engine speed sensor 37, an accelerator opening sensor 38, and the like, and a detection signal from these sensors is an ECU (control unit) 40. To be input.
[0024]
The ECU 40 controls the combustion state control means 42 that sets the combustion state to one of the stratified combustion mode or the uniform combustion mode according to the engine operating state, and controls the fuel to be cut when the engine is in a specific operating state. And when the fuel cut control is performed by the fuel cut means 44, the opening of the intake air amount adjusting means is brought to a state close to full closure, and the fuel cut control means 44 Fee There is provided an intake air amount control means 48 for controlling the intake air amount by opening the intake air amount adjusting means at the end of the cut control.
[0025]
The combustion state control means 42 responds to detection signals from the engine speed sensor 37 and the accelerator opening sensor 38, as shown in FIG. 2, when the engine speed and the engine torque are below a predetermined value, that is, the fuel injection amount. By performing late injection in which fuel is injected in the compression stroke at a low low load, combustion in the stratified combustion mode in which the vicinity of the spark plug 20 is locally rich while the entire interior of the combustion chamber 16 is in a lean state. When the engine speed and engine torque exceed the predetermined values, that is, when the fuel injection amount is high and the load is high, the fuel is evenly distributed in the cylinder by performing early injection that injects fuel during the intake stroke. It is configured to ignite in a state of being converted into a combustion state in a uniform combustion mode.
[0026]
In addition, when the engine is in a middle load between a low load and a high load, the fuel is divided into an early injection in which fuel is injected in the intake stroke and a late injection in which fuel is injected in the compression stroke. You may do it. That is, at the time of the medium load, the early injection is performed in order to ignite a part of the fuel in a cylinder in a uniform state, and the late injection is performed to stratify the remaining fuel. Good.
[0027]
Further, it is confirmed that the combustion state control means 42 is in a state in which the condition for ending the fuel cut control is satisfied and the fuel cut control is ended according to the control signal output from the fuel cut control means 44. In this case, the setting of the stratified combustion mode is prohibited for a certain period of time, and the combustion state of the engine is controlled so that the combustion state is in the uniform combustion mode. The predetermined time for prohibiting the setting of the stratified combustion mode is set to a time required for supplying an appropriate amount of intake air into the combustion chamber 16 of the engine after the electric throttle 28 is opened as will be described later. Yes.
[0028]
Further, the fuel cut means 44 is confirmed to have an accelerator opening of 0 according to the detection signal of the accelerator opening sensor 38, and the engine speed according to the detection signal of the engine speed sensor 37, As shown in FIG. 3, when it is confirmed that the rotation state is larger than a preset reference value N3 for fuel cut, the fuel cut control for stopping the fuel injection from the fuel injection valve 22 is executed. Is configured to do. When the fuel cut control is executed, it is confirmed that the engine speed is equal to or lower than the first reference value N1 set to a value smaller than the fuel cut reference value N3 and the engine is in a low speed state. The fuel cut control is terminated.
[0029]
Further, the intake air amount control means 48 brings the intake air amount adjusting means including the electric throttle 28 into a fully closed state when the fuel cut control is performed by the fuel cut means 44, and at the end of the fuel cut control. By opening the throttle 28, the intake air flow area is adjusted to control the amount of intake air supplied into the combustion chamber 16 of the engine.
[0030]
As described above, the engine speed becomes equal to or less than the first reference value N1 and the condition for terminating the fuel cut control is established. At the same time as the fuel cut control is terminated, the fuel is injected early and the engine is Transition to the combustion state of the uniform combustion mode. Then, after the combustion state in the uniform combustion mode continues for a certain time, the combustion control in the stratified combustion mode is normally performed by shifting from the early injection state of the fuel to the late injection state.
[0031]
Next, a specific control operation performed by the ECU 40 will be described based on the flowchart shown in FIG. When the control operation starts, first, after reading the engine operating state such as the engine speed ne and the accelerator opening ac (step S1), it is determined whether or not the accelerator opening ac is 0 (step S2). .
[0032]
If NO is determined in step S2, the flag F2 indicating that the combustion state is in the uniform combustion mode is reset to 0 (step S3), and normal combustion control is executed. That is, the fuel injection pulse Ti is obtained from the map (step S4), the opening th of the electric throttle 28 is obtained from the map (step S5), and the current operating state is handled from the stratified combustion mode or the uniform combustion mode. The determined mode is determined, the combustion control corresponding to the mode is executed, and the flag F1 indicating the fuel cut control state is reset to 0 (step S6).
[0033]
When YES is determined in step S2 and it is confirmed that the accelerator opening degree ac is 0, the engine speed ne detected by the engine speed sensor 37 is the fuel cut reference value N3. Or greater (step S7). If YES is determined, the fuel cut flag F1 is set to 1 and fuel cut control is executed (step S8). That is, the fuel injection pulse Ti is set to 0 to stop fuel injection (step S9), and the opening th of the electric throttle 28 is set to substantially 0 to make the intake passage 24 close to full close. (Step S10).
[0034]
Further, when it is determined NO in Step S7 and it is confirmed that the engine speed ne is equal to or less than the fuel cut reference value N3, the uniform combustion mode is set at the end of the fuel cut control. It is determined whether or not the count value of the timer for returning the combustion state to the normal combustion state is 0 (step S11), and it is determined as YES and it is confirmed that the timer has not started counting. In this case, it is determined whether or not the flag F2 indicating that the control mode is in the uniform combustion mode is reset to 0 (step S12).
[0035]
If it is determined as YES in step S12 and it is confirmed that the combustion control in the uniform combustion mode is not executed, the first reference that is a criterion for determining whether or not the engine speed ne ends the fuel cut control. It is determined whether or not the value is larger than the value N1 (step S13). If it is determined NO in step S13 and it is confirmed that the engine speed ne is equal to or less than the first reference value N1, the timer is set (step S14), and the combustion state of the engine is uniformly burned. The mode is set (step S15), and after setting the flag F2 indicating that the engine is in the control state of the uniform combustion mode to 1 (step S16), the process proceeds to step S4.
[0036]
When it is determined YES in step S11 and it is confirmed that the timer has timed up, and when it is determined NO in step S12 and it is confirmed that the flag F2 is set to 1. Then, the process proceeds to step S4, the setting of the uniform combustion mode is canceled, and the normal combustion state is entered. In this case, since the engine is normally in a low load state, the combustion state of the stratified combustion mode, that is, the late injection execution state is set.
[0037]
If it is determined YES in step S13 and it is confirmed that the engine speed ne is greater than the first reference value N1, it is determined whether or not the fuel cut flag F is set to 1. If it is determined NO (NO in step S17), the process proceeds to step S4 and normal combustion control is continued. If YES is determined, the process proceeds to step S9 and fuel cut control is performed. Continue to execute.
[0038]
When the engine speed becomes N1 or less and the fuel cut control is terminated as described above, the fuel is injected early for a predetermined time set by the timer so that the engine is in the combustion state of the uniform combustion mode. Control will be executed.
[0039]
Thus, the combustion state control means 42 for setting the combustion state of the engine to one of the stratified combustion mode and the uniform combustion mode, and the fuel cut means 44 for controlling the fuel to be cut when the engine is in a specific operation state. In the engine control apparatus, the intake air amount adjusting means including an electric throttle 28 provided in the intake passage 24 of the engine and the intake air amount adjusting means are almost fully closed when the fuel cut control is performed by the fuel cut means 44. And the above fuel Fee An intake air amount control means 48 for controlling the intake air amount by opening the intake air amount adjusting means at the end of the cut control is provided, and when the fuel cut control by the fuel cut means 44 is ended, the intake air amount control means 48 is controlled for a predetermined time. Since the engine combustion state is controlled so that the combustion state of the uniform combustion mode is controlled by prohibiting the setting of the stratified combustion mode, it is possible to effectively prevent the engine from misfiring at the end of the fuel cut control. Can do.
[0040]
That is, in order to prevent the catalyst temperature of the exhaust purification devices 35 and 36 from being lowered due to the low temperature intake air being supplied to the exhaust passage 34 during the execution of the fuel cut control, the electric throttle 28 and the like. When the engine is in a stratified combustion state at the end of the fuel cut control in a state where the intake air amount adjusting means is substantially fully closed, even if the intake air amount adjusting means is opened, the intake air amount caused by the response delay of the intake air Since the shortage occurs, the surroundings of the spark plug 20 are in an overrich state of fuel, and misfire is likely to occur. In contrast to this, Fee When the intake air amount adjusting means is opened at the end of the cut control and the setting of the stratified combustion mode is prohibited for a predetermined time so that the combustion state of the uniform combustion mode is achieved, the fuel diffuses. Therefore, it is possible to prevent the misfire from occurring effectively by preventing the vicinity of the spark plug 20 from becoming an overrich state of fuel.
[0041]
Further, in the above embodiment, in the cylinder injection type engine in which the fuel injection valve 22 is disposed in the combustion chamber 16, the fuel injection timing is set so that the fuel is injected from the fuel injection valve 22 in the compression stroke. Since the engine combustion state is set to the stratified combustion mode by setting, a small amount of fuel injected from the fuel injection valve 22 is concentrated around the spark plug 20 during the combustion control in the stratified combustion mode. Thus, the fuel can be properly stratified combustion.
[0042]
In the in-cylinder injection engine, when the fuel cut control is terminated and the fuel injection is restarted, the engine combustion state is set to the stratified combustion mode. Since this portion tends to be overrich due to concentration of fuel, the engine is prevented from misfiring by prohibiting the engine from entering a stratified combustion state at the end of the fuel cut control. Is particularly desirable.
[0043]
In the above embodiment, the example in which the combustion state of the engine is set to the uniform combustion mode by injecting fuel from the fuel injection valve in the intake stroke of the engine has been described. However, the end of the fuel cut control is described above. At the time, that is, when the fuel cut control is finished and the fuel injection is resumed, the fuel is injected from the fuel injection valve in both the intake stroke and the compression stroke of the engine, thereby suppressing the engine from entering the stratified combustion state. Thus, the combustion state of the engine may be set to the uniform combustion mode over a certain period of time.
[0044]
In the above embodiment, when the combustion state of the engine is set to the stratified combustion mode, the swirl generating means including the swirl control valve 32 is configured to operate. Therefore, the combustion state control is performed according to the operating state of the engine. When the combustion state of the engine is set to the stratified combustion mode by the means 42 and when the fuel cut control is terminated, and during the uniform combustion mode period of a certain time and when performing the stratified combustion mode combustion control after that period, By making the swirl control valve 32 fully closed or nearly fully closed, a swirl can be formed in the combustion chamber 16 and the combustion control in the stratified combustion mode can be properly executed.
[0045]
The swirl generating means may be omitted, and a tumble composed of vertical vortices may be generated in the combustion chamber 16 by opening the intake port downward or the like.
[0046]
Further, as shown in the above-described embodiment, the fuel injection valve 22 is disposed in the combustion chamber 16 and includes an electric throttle 28 on the upstream side of the collecting portion of the intake passage 24 located in the installation portion of the surge tank 30. When the intake air amount adjusting means is provided, the combustion control in the stratified combustion mode can be properly executed with a simple configuration. Moreover, even when there is a delay in the response of the intake air due to the long distance between the intake air amount adjusting means and the combustion chamber 16, the fuel can be reduced. Fee At the end of the cut control, the intake air amount adjusting means is opened and controlled to be in the combustion state of the uniform combustion mode for a certain period of time as described above. Misfire due to over-riching can be effectively prevented.
[0047]
In the above embodiment, when the engine speed ne becomes equal to or lower than the first reference value N1, the fuel cut control is completely terminated and the fuel injection control is returned to the normal state. However, at the end of the fuel cut control, the fuel injection amount may be gradually increased to return the fuel injection control stepwise or linearly.
[0048]
In the above embodiment, an example in which the present invention is applied to an in-cylinder injection engine in which the fuel injection valve 22 is disposed in the combustion chamber 16 has been described. However, the fuel injection valve is disposed in the intake port. The present invention can also be applied to an engine having a fuel injection valve disposed in both the combustion chamber 16 and the intake port. In this case, when the combustion state of the engine is set to the uniform combustion mode by the combustion state control means according to the operating state of the engine, or when the fuel cut control is terminated, the exhaust stroke of the engine Alternatively, in the first half of the intake stroke, the combustion state of the engine can be made a uniform combustion state by injecting fuel from a fuel injection valve disposed in the intake port.
[0049]
Further, in place of the electric throttle 28, a throttle bypass passage 50 is provided in the intake passage 24 as shown by a virtual line in FIG. 1, and an intake air amount adjusting means is constituted by a bypass valve 52 provided in the bypass passage 50. The opening / closing control of the bypass valve 52 may be performed at the end of the fuel cut control similarly to the electric throttle 28 according to the above embodiment.
[0050]
Further, in the above embodiment, when the fuel cut control is executed, all the intake air amount adjusting means are provided so that the intake air amount necessary for executing the combustion control in the uniform combustion mode is secured at the end of the fuel cut control. Although an example has been described in which it is configured so that it is close to a fully open state without being closed, the intake air amount adjusting means is opened by the intake air amount control means 48 immediately before the end of the fuel cut control. Thus, the intake air amount adjusting means may be fully closed when the fuel cut control is executed by securing the intake air amount.
[0051]
In other words, the engine speed detected by the engine speed sensor 37 is set to a value slightly larger than the first reference value N1, which is a criterion for determining whether or not to end the fuel cut control. By determining that the value was below the Fee When it is confirmed that the intake air amount adjusting means is opened when it is confirmed that the cut control is in a state immediately before the end, the intake air amount adjusting means is fully closed when the fuel cut control is executed. In addition, it is possible to secure the intake air amount necessary for executing the combustion control in the uniform combustion mode at the end of the fuel cut control.
[0052]
【The invention's effect】
As described above, the present invention cuts fuel when the engine is in a specific operating state, and the combustion state control means for setting the combustion state to one of the stratified combustion mode or the uniform combustion mode according to the operating state of the engine. In the engine control device having the fuel cut means for controlling the intake air amount, the intake air amount adjusting means provided in the intake passage of the engine for adjusting the intake passage area and the fuel intake control when the fuel cut control is performed by the fuel cut means. While the amount adjusting means is substantially fully closed, Fuel injection resumes Above fuel Fee An intake air amount control means for controlling the intake air amount by opening the intake air amount adjusting means at the end of the cut control, and the fuel cut control by the fuel cut means From the end of Set the stratified combustion mode for a certain period of time. Ban In order to control the combustion state of the engine so that the combustion state of the uniform combustion mode is achieved, when the fuel cut control is performed, the low temperature intake air is supplied to the exhaust passage. It is possible to effectively prevent the occurrence of misfire due to an overrich state of the fuel around the spark plug by making the uniform combustion state when restarting the fuel injection while preventing the temperature from decreasing. There are advantages.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an embodiment of an engine control apparatus according to the present invention.
FIG. 2 is a map showing control regions in a stratified combustion mode and a uniform combustion mode.
FIG. 3 is a time chart showing a combustion control state executed by the control device.
FIG. 4 is a flowchart showing a control operation of an ECU constituting the control device.
[Explanation of symbols]
10 Engine body
16 Combustion chamber
20 Spark plug
22 Fuel injection valve
28 Electric throttle (intake air volume adjusting means)
30 Surge tank (collection part of intake passage)
32 Swirl control valve (swirl generating means)
40 ECU
42 Combustion state control means
44 Fuel cut means
48 Intake air amount control means
52 Bypass valve (intake air amount adjusting means)

Claims (7)

Combustion state control means for setting the combustion state to one of stratified combustion mode or uniform combustion mode according to the operating state of the engine, and fuel cut means for controlling the fuel to be cut when the engine is in a specific operating state And an intake air amount adjusting means provided in an intake air passage of the engine for adjusting an intake air passage area, and when the fuel cut control by the fuel cut means is executed, the intake air amount adjusting means is in a substantially fully closed state. to together, with and an intake air amount control means for the fuel injection is controlled amount of intake air opening is activated the intake air amount adjustment means at the end of the fuel cut control to be resumed, the fuel cut control by the fuel cut means combustion engine so that the combustion state of the homogeneous combustion mode prohibits the setting of the stratified combustion mode from the end over a predetermined time Engine control apparatus wherein controlling the state. 2. The engine control device according to claim 1, wherein the fuel injection valve is disposed in a combustion chamber of the engine, and the fuel is injected from the fuel injection valve during the compression stroke of the engine, thereby changing the combustion state of the engine to the stratified combustion mode. An engine control device characterized by being configured to be set to. 3. The engine control device according to claim 2, wherein the engine combustion state is set to a uniform combustion mode by injecting fuel from a fuel injection valve during an intake stroke of the engine. apparatus. 3. The engine control apparatus according to claim 2, wherein the engine combustion state is set to a uniform combustion mode by injecting fuel from the fuel injection valve in both the intake stroke and the compression stroke of the engine. Engine control device. 2. The engine according to claim 1, wherein the combustion state of the engine is set to a uniform combustion mode by injecting fuel from the fuel injection valve in a stroke other than the compression stroke of the engine. apparatus. 6. The engine control apparatus according to claim 1, wherein the fuel injection valve is disposed in the combustion chamber, and an intake air amount adjusting means is disposed upstream of the collecting portion of the intake passage. The engine control device. The engine control device according to any one of claims 1 to 6, further comprising a swirl generating unit, wherein the swirl generating unit is operated when the combustion state of the engine is set to a stratified combustion mode. An engine control device.

Images