Method for adjusting the oxygen concentration in a three-way catalytic converter system

US6571550B2 · kind B2 · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Gerd Rösel · Dresden, DE
• Hong Zhang · Tegernheim, DE

Key dates

• Filing date: Feb 27, 2002
• Grant date: Jun 3, 2003
• Expiry date: Feb 27, 2022

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/12
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

For a three-way catalytic converter system with a preliminary catalytic converter, a main catalytic converter and an oxygen sensor with a constant characteristic curve disposed between the two catalytic converters, a method for resetting the oxygen concentration in the preliminary catalytic converter and the main catalytic converter in the event of a transition from lean-burn operation to stoichiometric operation includes exposing both catalytic converters to a rich mix until the desired oxygen concentrations have been reached. In the process, the constant measurement signal from the oxygen sensor and the measurement signal from an air mass flow meter are used to calculate the quantity of oxygen that is released to the exhaust gas from the main catalytic converter, in order to end rich-burn operation when a predetermined desired value is reached.