System controlling any air/fuel ratio with stoichiometric sensor and asymmetrical integration

摘要

In a fuel management system for an internal combustion engine, a system utilizing a stoichiometric gas sensor in the exhaust gas system for supplying an electrical signal to an asymmetrical integrator which controls and maintains any desired air/fuel ratio to the engine. By means of the system, the air/fuel ratio may be maintained slightly richer than stoichiometric for optimum catalytic converter operation. For very lean air/fuel ratios, a delay circuit is used in the system to continue the time the fuel mixture is in a lean condition before the mixture is controllably changed to a rich mixture for sensing by the sensor.