Method and device for operating an internal combustion engine

US8315782B2 · kind B2 · utility

Assignee

• CONTINENTAL AUTOMOTIVE GMBH · DE

Inventors

• Nicole Fuhrmann · Lappersdorf, DE
• Stefan Seyfferth · Regensburg, DE

Key dates

• Filing date: Apr 17, 2009
• Grant date: Nov 20, 2012
• Expiry date: Jun 21, 2029

Classification

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

Abstract

An internal combustion engine has an exhaust gas tract with a first and a second exhaust gas catalyst downstream of the first one, a first exhaust gas sensor, which is disposed upstream or in the first catalyst, and a second exhaust gas sensor, which is disposed downstream of the first catalyst and upstream of the second catalyst. During trailing throttle operation, the measurement signal of the second sensor is monitored for a signal characteristic that is typical of a maximum possible saturation state with oxygen that the first catalyst can achieve, upon which a characteristic variable is determined for a saturation state of the second catalyst with oxygen as a function of an engine operating variable. Outside the trailing throttle operation, an enrichment mode is controlled by enriching the air/fuel mixture, specifically as a function of the characteristic variable for the saturation state of the second catalyst with oxygen.