Air-fuel ratio feedback control system including at least downstream-side air fuel ratio sensor
US5022225A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 1990 |
| Grant date | Jun 11, 1991 |
| Priority date | — |
| Expiry date | Mar 23, 2010 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2200/021
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
In an air-fuel ratio feedback control system including at least one air-fuel ratio sensor downstream of a catalyst converter provided in an exhaust gas passage, an actual air-fuel ratio is controlled in accordance with the output of the downstream-side air-fuel ratio sensor. When at least one of the air-fuel ratio feedback control conditions for the downstream-side air-fuel ratio sensor is not satisfied the controlled air-fuel ratio is made an air-fuel ratio by an open loop control, while all the air-fuel ratio feedback control conditions for the downstream-side air-fuel ratio sensor are satisfied the controlled air-fuel ratio is made the stoichometric ratio (.lambda.=1) in accordance with the output of the downstream-side air-fuel ratio sensor. For a period after all the air-fuel ratio feedback control conditions for the downstream-side air-fuel ratio sensor are satisfied, the control by the output of the downstream-side air-fuel ratio sensor is prohibited, but, the controlled air-fuel ratio is made the stoichiometric ratio (.lambda.=1) by an open loop control or by the output of an upstream-side air-fuel ratio sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.