Coarse and fine air supply control for closed-loop controlled carbureted internal combustion engines
US4303049A · kind A · utility
Inventors
Key dates
| Filing date | Jul 6, 1979 |
| Grant date | Dec 1, 1981 |
| Priority date | — |
| Expiry date | Jul 6, 1999 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02M7/24
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
In a closed loop air-fuel mixture control system for carburetor-equipped internal combustion engines, an exhaust gas sensor provides a feedback signal to a control unit where the signal is modified to meet the control characteristics of the closed loop. The modified feedback signal is converted into digital pulses whose width varies with the amplitude of the feedback signal. Additional air is supplied to the engine through an air bleed in accordance with the magnitude of the analog feedback signal to provide a coarse control of air-fuel ratio and in response to the digital pulses to provide a fine control of the ratio. The mixture is controlled in a wide range of ratios to eliminate the need for calibration which would be required for fitting the closed loop system to the time-varying characteristics of individual carburetors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.