Altitude compensation feature for electronic fuel management systems
US4212065A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 1978 |
| Grant date | Jul 8, 1980 |
| Priority date | — |
| Expiry date | Jun 22, 1998 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2200/703
- 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 the 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 provisions for an altitude compensation feature. The altitude compensation feature includes circuitry to modify the intake manifold pressure portion of the speed density schedule with two variables which depend on altitude. Power enrichment for the pressure schedule is provided as a function of altitude by lowering a power enrichment break point for increases in altitude and enrichment for all values of intake pressure is provided as a function of altitude to compensate for the internal EGR of the engine and to provide increased utilization for the closed loop controller.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.