Method of operating a spark ignition internal combustion engine

US7654245B2 · kind B2 · utility

Assignee

• Daimler AG · DE

Inventors

• Bernd Kohler · Obertshausen, DE
• Christoph Lux · Stuttgart, DE
• Michael Oechsle · Sindelfingen, DE
• Matthias Werner · Stuttgart, DE

Key dates

• Filing date: Mar 13, 2008
• Grant date: Feb 2, 2010
• Expiry date: Mar 13, 2028

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

In a method for operating a spark-ignition, direct-injection internal combustion engine, wherein fuel is injected into a cylinder of the internal combustion engine and is ignited by a spark plug as a function of at least the load of the internal combustion engine, a crank angle is determined at which a first amount of fuel is injected into the cylinder during the intake stroke whereby a lean mixture is formed in the cylinder, subsequently, as a function of at least the load of the internal combustion engine, a crank angle is determined at which a second amount of fuel is injected, whereby a mixture cloud, which is richer than the lean mixture is formed in the lean mixture and a third amount of fuel is injected in the form of a stratified injection for forming a locally enriched and ignitable fuel/air mixture in the region of the spark plug close to an ignition time which is then ignited by the spark plug causing also combustion of the mixture cloud and the lean mixture.