Start and warm up features for electronic fuel management systems
US4246639A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 1978 |
| Grant date | Jan 20, 1981 |
| Priority date | — |
| Expiry date | Jun 22, 1998 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/266
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An electronic control unit for regulating the air/fuel ratio of an internal combustion engine is disclosed. The electronic control unit has an open loop calibration for regulating air/fuel ratio that is corrected with a closed loop correction signal developed by an integral controller. The open loop calibration is a speed-density based schedule which is combined with corrections for special conditions to account for the operating parameters of the engine at any instant. Included in these special condition corrections are provision for start and warm-up features. The start feature includes an enrichment pulse generator whose pulses have a duration dependent upon the engine operating temperature and speed which are inhibited while the engine is above a predetermined RPM. The warm-up feature includes a time and temperature dependent enrichment which is linearly multiplied by an engine load factor. The warm-up feature further includes a time dependent holding level or delay from which the enrichment factor value decays during warm up and a feature to defeat this holding level above a certain engine operating temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.