Internal combustion engine air-fuel ratio control apparatus and method
US8381707B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 2009 |
| Grant date | Feb 26, 2013 |
| Priority date | — |
| Expiry date | Jul 15, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
Internal combustion engine air-fuel ratio control apparatus and method in which the target air-fuel ratio of exhaust gas flowing into an exhaust-gas purification catalyst unit is controlled through at least proportional-integral control such that the correction amount per unit time of the oxygen amount in said catalyst unit is maintained constant. When the intake air amount is smaller than a predetermined amount and the air-fuel ratio detected by an oxygen sensor provided downstream of the catalyst unit is rich, the target air-fuel ratio is controlled to suppress an increase in the air-fuel ratio in the exhaust-gas purification catalyst unit. Accordingly, even if rapid acceleration operation is performed in a state where the intake air amount is extremely small and the air-fuel ratio detected by the oxygen sensor is rich, NOx in exhaust gas can be sufficiently removed through reduction reactions at the exhaust-gas purification catalyst unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.