Method for operating an internal combustion engine

US7337658B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Andreas Pfaeffle · Löwenstein, DE
• Wolfgang Klenk · Besigheim, DE
• Stefan Scherer · Büttelborn, DE
• Simone Neuberth · Walzbachtal, DE
• Albrecht Schwaderer · Untergruppenbach, DE

Key dates

• Filing date: Apr 6, 2004
• Grant date: Mar 4, 2008
• Expiry date: Apr 20, 2024

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Environmental technology
• WIPO sector: Chemistry

Abstract

A method is described for operating an internal combustion engine, in particular of a motor vehicle. In the method, a lean air/fuel mixture is burned in a combustion chamber; nitrogen oxides contained in the exhaust gas are stored in an accumulator-type catalytic converter; a storage efficiency, with which the accumulator-type catalytic converter stores the nitrogen oxides contained in the exhaust gas, is ascertained; and the storage efficiency is ascertained as a function of an instantaneous space velocity of the exhaust gases in the accumulator-type catalytic converter. Two efficiencies are ascertained at least as a function of the temperature of the accumulator-type catalytic converter and a space velocity. One of the two efficiencies is ascertained for a great space velocity, and the other efficiency is ascertained for a small space velocity. The storage efficiency is ascertained as a function of the instantaneous space velocity from the two efficiencies.