Method and apparatus for operating a diesel engine

US5771686A · kind A · utility

Assignee

• Mercedes-Benz Group AG · DE

Inventors

• Stefan Pischinger · Aachen, DE
• Christof Schon · Winnenden, DE
• Michel Weibel · Großburgwedel, DE
• Bernd Krutzsch · Köngen, DE
• Rudiger Pfaff · Stuttgart, DE
• Walter Boegner · Waiblingen, DE

Key dates

• Filing date: Nov 20, 1996
• Grant date: Jun 30, 1998
• Expiry date: Nov 20, 2016

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02C20/10
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A method and an apparatus are provided for operating a diesel engine with an exhaust feedback device located between the exhaust line and the intake air line, with an adjusting element that can be operated by an adjusting drive actuated by an auxiliary force to operate the exhaust feedback device as a function of signals from an electronic control device. An engine regulator permits rich/lean regulation of the diesel engine as a function of its operating parameters. A storage catalyst is located in the exhaust line, in which catalyst oxides of nitrogen (NO.sub.x) can be adsorbed, desorbed, and reduced. A sensor is located downstream from the storage catalyst for detecting the NO.sub.x concentration in the exhaust stream in such fashion that when an NO.sub.x storage threshold value is reached that varies in terms of its characteristics as a function of the rpm and the load, a switch is made from operation with a lambda value of larger than 1 to operation with a lambda value of less than 1.