Double air-fuel ratio sensor system having improved exhaust emission characteristics
US4817384A · kind A · utility
13Cited by
11References
58Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 11, 1987 |
| Grant date | Apr 4, 1989 |
| Priority date | — |
| Expiry date | Aug 11, 2007 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/1441
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
In a double air-fuel sensor system including two air-fuel ratio sensors upstream and downstream of a catalyst converter provided in an exhaust gas passage, an air-fuel ratio correction amount is calculated in accordance with the outputs of the upstream-side and downstream-side air-fuel ratio sensors, thereby obtaining an actual air-fuel ratio. The air-fuel ratio correction amount is guarded within a predetermined range. When this correction amount reaches the maximum or minimum value of the range, the calculation of the air-fuel ratio correction amount by the output of the downstream-side air-fuel ratio sensor is prohibited.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.