The invention relates to a fuel supply system for a spark-ignition internal combustion engine having arranged on each cylinder a blow-in nozzle for the introduction of a mixture of fuel and a combustion gas into a combustion chamber.
Spark-ignition internal combustion engines have an unsatisfactory efficiency in particular in the part-load range as a result of high charge exchange losses. One possibility for reducing said charge exchange losses and thereby improving efficiency resides in exhaust gas recirculation. By means of exhaust gas recirculation, the engine can operate unthrottled during part-load operation, which reduces the required charge exchange work of the engine and increases the compression pressure.
An increase in the proportion of recirculated exhaust gas can however also bring about a degradation of the ignitability and combustion of the mixture of fuel, air and exhaust gas. Misfiring can even occur.
In order to utilize the advantages of a high exhaust gas recirculation rate and in order to obtain the ignitability required for this purpose, DE 199 45 544 A1 discloses a fuel supply system for a spark-ignition internal combustion engine in which a first fuel metering device comprises an intake pipe injector which is arranged in an intake duct which opens out into the combustion chamber. By means of the intake pipe injector, a fuel quantity is injected in order to form a lean mixture with a predefined exhaust gas proportion. For reliable ignition, one blow-in valve is provided per cylinder, which blow-in valve, in order to ignite the lean mixture, blows a mixture of a small liquid fuel quantity and air as a combustion gas into the combustion chamber. The quantity which is blown in can be easily and reliably ignited. After ignition, the mixture quantity ignites the remaining mixture.
It is the principal object of the present invention to provide an internal combustion engine with a fuel supply system which is small and effectively supplies a mixture of fuel and combustion air into the cylinders of the engine.