Air fuel ratio sensor deterioration determination system for compression ignition internal combustion engine
US7520274B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2005 |
| Grant date | Apr 21, 2009 |
| Priority date | — |
| Expiry date | Sep 3, 2025 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/1454
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
In a compression ignition internal combustion engine provided with an NOx storage-reduction catalyst on an exhaust system, when the air fuel ratio of the exhaust gas being in a lean state is controlled to a rich state, a response time (ResS) from a time point an air fuel ratio sensor detects a first air fuel ratio (AF1), which is leaner than a stoichiometric air fuel ratio (AFS), to a time point the air fuel ratio sensor detects a second air fuel ratio (AF2), which is equal to or leaner than the stoichiometric air fuel ratio (AFS) and richer than the first air fuel ratio (AF1). When the response time (ResS) exceeds a stoichiometric air fuel ratio shift reference time (StdS), a determination is made that the air fuel ratio sensor is degraded.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.