A/F ratio control system for internal combustion engine
US5363648A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 1993 |
| Grant date | Nov 15, 1994 |
| Priority date | — |
| Expiry date | Dec 27, 2013 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2041/1433
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A system for controlling an air/fuel ratio of a four-cylinder internal combustion engine. In the system, an actual air/fuel ratio, at least at upstream or downstream of a catalytic converter installed at an exhaust system of the engine, is intentionally oscillated at least either in its amplitude or cycle. A characteristic of a desired air/fuel ratio as a periodic function is established with respect to time such that the desired air/fuel ratio varies at least either at a predetermined amplitude or cycle within a predetermined period. The characteristic is sampled by a time interval determined on the basis of a time interval between TDC crank angle positions of the engine. Each cylinder's desired air/fuel ratio is then determined from the sampled data, and a fuel injection amount for each cylinder is determined from the respective cylinder's desired air/fuel ratios. Fuel is then supplied to each cylinder in response to the determined fuel injection amount. The actual air/fuel ratio at each cylinder is detected or estimated and feedback controlled to the desired air/fuel ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.