Abstract: In an internal combustion engine which performs a homogeneous lean combustion mode and a stratified lean combustion mode, there is provided a new internal combustion engine control device capable of obtaining a stable combustion state by decreasing influences of delay of an air flow and a degree of change of a transient state and smoothly performing switching between the homogeneous lean combustion mode and the stratified lean combustion mode.

Abstract: In an internal combustion engine which performs a homogeneous lean combustion mode and a stratified lean combustion mode, there is provided a new internal combustion engine control device capable of obtaining a stable combustion state by decreasing influences of delay of an air flow and a degree of change of a transient state and smoothly performing switching between the homogeneous lean combustion mode and the stratified lean combustion mode.

Abstract: Provided is an engine control device that can suppress an increase in PM/PN in an engine that performs a catalyst warm-up mode. To do so, the engine control device according to the present invention synchronously controls ignition timing and an actual compression ratio of the engine in the catalyst warm-up mode.

Abstract: Provided is an engine control device capable of suppressing deterioration of combustion stability due to a change in engine temperature in an engine which performs lean combustion or EGR combustion. When lean combustion in which an air-fuel mixture leaner than a stoichiometric air-fuel ratio is burned or exhaust gas recirculation combustion in which a diluted air-fuel mixture is burned by re-suctioning exhaust gas discharged from the combustion chamber into the combustion chamber is performed, a ratio of a fuel injection amount during a compression stroke to a total fuel injection amount during one combustion cycle is increased as a temperature of an engine decreases.

Abstract: Provided is an engine control device capable of suppressing deterioration of combustion stability due to a change in engine temperature in an engine which performs lean combustion or EGR combustion. When lean combustion in which an air-fuel mixture leaner than a stoichiometric air-fuel ratio is burned or exhaust gas recirculation combustion in which a diluted air-fuel mixture is burned by re-suctioning exhaust gas discharged from the combustion chamber into the combustion chamber is performed, a ratio of a fuel injection amount during a compression stroke to a total fuel injection amount during one combustion cycle is increased as a temperature of an engine decreases.

Abstract: Provided is an engine control device that can suppress an increase in PM/PN in an engine that performs a catalyst warm-up mode. To do so, the engine control device according to the present invention synchronously controls ignition timing and an actual compression ratio of the engine in the catalyst warm-up mode.

Abstract: At the start-up of an engine, the ignition timing and the air-fuel ratio are controlled to prevent overload onto the volume of ISC air and decreased torque and torque difference. The fuel condition based on the amount of ignition timing correction to inhibit rotational fluctuation during idling is determined and the fuel quantity based on the result is corrected. Right after an engine has started and until a pilot burner is created in the heat spot of the catalyst, the ignition retard control is mainly executed, and at the time when it is determined that a pilot burner has been created in the catalyst's heat spot, the lean air-fuel ratio control is to be executed instead of the ignition retard control. Furthermore, when the ignition retard control changes to the lean air-fuel ratio control, the state transition control is executed along the equivalent ISC air volume line so as not to cause torque fluctuation.

Abstract: At the start-up of an engine, the ignition timing and the air-fuel ratio are controlled to prevent overload onto the volume of ISC air and decreased torque and torque difference. The fuel condition based on the amount of ignition timing correction to inhibit rotational fluctuation during idling is determined and the fuel quantity based on the result is corrected. Right after an engine has started and until a pilot burner is created in the heat spot of the catalyst, the ignition retard control is mainly executed, and at the time when it is determined that a pilot burner has been created in the catalyst's heat spot, the lean air-fuel ratio control is to be executed instead of the ignition retard control. Furthermore, when the ignition retard control changes to the lean air-fuel ratio control, the state transition control is executed along the equivalent ISC air volume line so as not to cause torque fluctuation.