Direct injection, turbocharge and load dependence Internal exhaust gas recirculation Air compression Natural combustion or spark ignition 4-stroke internal combustion engine

摘要

An air-compressing, self-ignition or spark-ignition, four-stroke internal combustion engine having direct fuel injection, turbo-charging, and load-dependent exhaust gas recirculation which is effected, at least in certain operating ranges, by intervention in the gas change system. In order to prevent weakening of the air swirl energy (charge swirl energy) by exhaust gas recirculation at low load in such an internal combustion engine, on the one hand, and, on the other hand, to obtain assisted cylinder scavenging at higher loads, the intake valve is briefly opened during the exhaust stroke. The opening of the intake valve occurs no earlier than 30 degress crank angle after gas-change bottom dead center, and the highest lift is between 15 and 30% of the maximun intake valve lift; and, at the latest, when the exhaust valve closes (shortly before gas change top dead center). Only a minimum opening of the intake valve exists and this is maintained until the start of the intake stroke (shortly after gas change top dead center).