Method for the lambda control of an internal combustion engine having a catalyzer

US5203165A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Ernst Wild · Oberriexingen, DE
• Gunther Plapp · Echterdingen, DE
• Lothar Raff · Waiblingen, DE
• Michael Westerdorf · Asperg, DE
• Eberhard Schnaibel · Hemmingen, DE

Key dates

• Filing date: Jul 31, 1991
• Grant date: Apr 20, 1993
• Expiry date: Jul 31, 2011

Classification

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

Abstract

The invention is directed to a method for lambda control of an internal combustion engine having a catalyzer and a measuring probe arrangement in front of the catalyzer for emitting a measuring signal and a testing probe arrangement behind the catalyzer for emitting a test signal. The method includes the steps of: forming a ratio between the measuring signal and the test signal at pregiven operating conditions; evaluating said ratio as an estimating quantity for the conversion rate of the catalyzer; and, modifying output values of control parameters in a pregiven controlled manner on the basis of the instantaneous values of said ratio, said output values being applicable for controlling an internal combustion engine having a new catalyzer. This method affords the advantage that it evaluates a catalyzer with the aid of the above-mentioned ratio value and controllably modifies values of control parameters in dependence upon the evaluation ratio. This leads to an especially stable control with low toxic gas discharge.