Patent ID: 6345500
Filing Date: 2002-02-12
Classification: F02B,F02D,Y02T

Abstract:
A cylinder injection spark-ignition engine, comprising:a spark plug to ignite an air mixture fuel in a combustion chamber; a fuel injector to inject fuel directly into the combustion chamber; a catalytic converter interposed in an exhaust passage; a temperature sensor for sensing a temperature Tcat of said catalytic converter; an airflow sensor for sensing and determining the amount of air being inducted into the engine; and a controller, programmed to: command the injector to inject a main injection of a fuel injection quantity Ti1 into the combustion chamber for a first time duration within at least one of a suction stroke and a compression stroke and to inject a sub injection of an additional fuel injection quantity Ti2 for a second time duration within at least one of an expansion stroke and an exhaust stroke; to set a target total air-fuel mixture ratio for a warm-up condition of the catalytic converter depending on the sensed catalytic converter temperature Tcat, the target total air-fuel mixture ratio being leaner than a stoichiometric air-fuel mixture ratio; to calculate a total fuel injection amount of the main and sub injections based on the target A/F ratio and the amount of airflow; and to split the total fuel injection into the main and sub injections in such a manner that the sum of the main and additional amounts is equal to the total fuel injection.