Abstract: A direct injection type internal combustion engine has an intake and exhaust mechanism for intaking and exhausting air for a predetermined period of time between a second half of a second expansion stroke and a first half of a first compression stroke following the second expansion stroke so that the first compression stroke, a first expansion stroke, a second compression stroke, and the second expansion stroke can be repeated sequentially along with rotation of a crank shaft; and a control device for controlling fuel injection. The control device injects first fuel during the first compression stroke and injects second fuel during the first expansion stroke or the second compression stroke. Therefore, the first fuel executes the first combustion process, and the second fuel is then injected into burnt gases generated in the first combustion process to enable a second combustion process following the first combustion process.

Abstract: A direct injection type internal combustion engine has an intake and exhaust mechanism for intaking and exhausting air for a predetermined period of time between a second half of a second expansion stroke and a first half of a first compression stroke following the second expansion stroke so that the first compression stroke, a first expansion stroke, a second compression stroke, and the second expansion stroke can be repeated sequentially along with rotation of a crank shaft; and a control device for controlling fuel injection. The control device injects first fuel during the first compression stroke and injects second fuel during the first expansion stroke or the second compression stroke. Therefore, the first fuel executes the first combustion process, and the second fuel is then injected into burnt gases generated in the first combustion process to enable a second combustion process following the first combustion process.

Abstract: An exhaust-gas temperature raising system for a spark-ignition, in-cylinder injection type internal combustion engine includes an electronic control unit. In case that the engine is in an operating condition where the exhaust-gas temperature is required to rise, on an occasion of a main-fuel injection in a compression stroke, the electronic control unit controls engine control parameters such as ignition timing and air-fuel ratio to cause a cool-flame-reaction product, which remains in a combustion chamber in a middle stage or a subsequent stage of an expansion stroke, to have a concentration close to an inflammable concentration limit, and then causes an additional fuel to be injected into the combustion chamber from the fuel injection valve in the middle stage or the subsequent stage of the expansion stroke.

Abstract: An exhaust-gas temperature raising system, installed in an in-cylinder injection type internal combustion engine adapted to spark-ignite fuel injected from a fuel injection valve directly into a combustion chamber, includes an electronic control unit which controls the fuel injection valve to inject the fuel, at a delayed fuel-injection timing in a compression stroke of the engine, in such an amount as to form an overrich air-fuel mixture locally around an ignition plug together with air in the combustion chamber, when the engine is in an operating condition in which an exhaust-gas temperature is required to rise.