Air/fuel ratio detection system for multicylinder internal combustion engine
US5600056A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 1995 |
| Grant date | Feb 4, 1997 |
| Priority date | — |
| Expiry date | Jun 6, 2015 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2041/1433
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An air/fuel ratio detection system for a multicylinder internal combustion engine having an air/fuel ratio sensor installed at the exhaust system confluence point of the engine. The sensor outputs are successively stored in buffers. In the engine, the distances of the individual cylinder exhaust ports to the sensor are different for all cylinders, which affects the air/fuel ratio detection. Moreover, the engine operating conditions also affect the detection. For that reason, mapped data called timing maps are prepared for the individual cylinders to be retrieved according to the engine speed and manifold absolute pressure for sampled data selection. The timing maps enable the system to select one from among sampled data which approximates the actual behavior of the air/fuel ratio at the confluence point in response to the distances from the cylinder exhaust port to the sensor and the operating conditions of the engine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.