Volkswagen Ag

Oliver Fladung

Ekkehard Pott

Leo Spiegel

Dirk Hagelstein

Jörg Theobald

Eduard Lippert

Michael Lindlau

Bernd Stiebels

Florian Noodt

J&ouml;rg Theobald

Mustafa Bastug

Rainer Radloff

Jörg Worm

Marc Schweizer

A method for operating an internal combustion engine in the form of an Otto engine, especially of a motor vehicle, selectively uses carburetor fuel, especially gasoline or ethanol (E85) by direct injection into at least one combustion chamber of the internal combustion engine by means of at least one fuel injector. Optionally, instead of injecting ignition spark engine fuel or in addition to injecting ignition spark engine fuel, the internal combustion engine is operated with gas, especially CNG (Compressed Natural Gas) or LPG (Liquefied Petroleum Gas). A mixture adaptation value is continuously determined during the operation of the internal combustion engine with spark ignition engine fuel. An actual mixture adaptation value is stored in a memory during the operation of the internal combustion engine with the spark ignition engine fuel and, after a predetermined minimum duration of operation with gas, an actual mixture adaptation value is compared with the stored mixture adaptation value during the operation of the internal combustion engine with ignition spark engine fuel. The fuel injectors are scavenged when a difference between the actual mixture adaptation value and the stored mixture adaptation value exceeds a predetermined difference value.

Method of operating an internal combustion engine

The invention relates to a four stroke internal combustion engine with applied ignition, wherein fuel is directly injected into a combustion chamber by means of an injector. Said engine comprises at least one admission channel with an admission valve and at least one exhaust channel with an exhaust valve, the admission valve and the exhaust valve being placed on opposite sides of the combustion chamber and the injector being placed on the admission valve side. Said engine also comprises a cavity formed in a piston top. A piston exhibits a central longitudinal axis extending in the direction of displacement of said piston. The cavity is placed on the admission valve side and exhibits, relatively to said admission valve and the injector, a marginal area forming the highest point of the piston top so that an airflow originating in the appropriately designed admission channel and penetrating into the combustion chamber through the admission valve and an injection jet originating in the injector and penetrating into the combustion chamber enter the cavity at opposite points.

Four-stroke internal combustion engine with direct injection

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Braunschweig, Germany

Oliver Fladung