Engine air-fuel ratio controller
US5600948A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 1994 |
| Grant date | Feb 11, 1997 |
| Priority date | — |
| Expiry date | Jul 19, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A control constant in air-fuel ratio feedback control is determined based on steady state engine running conditions. The difference between the exhaust gas temperature when the engine is In the steady state and the real exhaust gas temperature is found, and the control constant is corrected to rich or lean based on this difference. Preferably, the control constant is corrected to rich when the real exhaust gas temperature is lower than the steady state exhaust gas temperature by more than a fixed value. For example during acceleration or Immediately after start-up, even If the engine speed and load are the same as in the steady state, the exhaust gas temperature is lower than the exhaust gas temperature in the steady state. On the other hand, the air-fuel ratio at which the exhaust conversion efficiency of the catalytic converter is optimized varies with the exhaust gas temperature. However, the aforesaid correction procedure adjusts the air-fuel ratio according to the real exhaust gas temperature, hence the exhaust gas conversion efficiency of the converter is always at its optimum level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.