Air-fuel ratio control system for internal combustion engines
US5954028A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 1997 |
| Grant date | Sep 21, 1999 |
| Priority date | — |
| Expiry date | Aug 7, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2200/1015
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An air-fuel ratio control system for an internal combustion engine includes an air-fuel ratio sensor arranged in an exhaust system thereof for generating an output substantially proportional in value to an air-fuel ratio of exhaust gases emitted from the engine. An amount of variation in combustion of the engine is detected. A desired air-fuel ratio of a mixture supplied to the engine is set to a value leaner than a stoichiometric air-fuel ratio based on the amount of variation in combustion of the engine, when the engine is in a predetermined operating condition. Feedback control of an air-fuel ratio of the mixture to the desired air-fuel ratio is carried out in response to the output from the air-fuel ratio sensor. The desired air-fuel ratio is set to a richer value than an immediately preceding value thereof when the amount of variation in combustion of the engine detected is large and to a leaner value than the immediately preceding value thereof when the amount of variation in combustion of the engine is small. A value of the desired air-fuel ratio set is learned as an actual lean limit of the air-fuel ratio for stable combustion of the engine. A rate of change of the desired …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.