Air-fuel ratio control device for internal combustion engine
US8230846B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 2008 |
| Grant date | Jul 31, 2012 |
| Priority date | — |
| Expiry date | Feb 17, 2030 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/1441
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
The present invention relates to an air-fuel ratio control device for an internal combustion engine, and makes it possible to maintain high purification performance by suppressing a decrease in the oxygen occlusion capability of a catalyst. When an O2 sensor output oxs is greater than a reference value oxsref, which corresponds to a stoichiometric air-fuel ratio, and smaller than an upper threshold value oxsrefR, a sub-FB reflection coefficient is fixed at a predetermined value vdox2 for providing a lean air-fuel ratio. When, on the other hand, the O2 sensor output oxs is smaller than the reference value oxsref and greater than a lower threshold value oxsrefL, the sub-FB reflection coefficient is fixed at a predetermined value vdox2 for providing a rich air-fuel ratio. The sub-FB reflection coefficient reflects the O2 sensor output oxs in the calculation of a fuel injection amount and increases or decreases to have a consequence on the air-fuel ratio of an exhaust gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.