Air-fuel ratio regulator for IC engine - uses two feedback control signals derived from respective oximeter on either side of exhaust catalytic converter

摘要

Two exhaust O2 sensors (86, 88) are installed respectively upstream and downstream from the convertor (24) and wired to a regulator unit (68) which also receives signals denoting crankshaft angular position (70), throttle opening (74), combustion chamber knock (76), coolant temp. (78), intake air flow (10) and engine speed. Control signals are supplied to a fuel injector (30), idling speed regulator (56) and power-control air regulator (62). A learning value for feedback control is worked out from the arithmetic mean of values obtd. shortly before previous and current jumps in a control value. ADVANTAGE - A logical mixt. of air and fuel is maintained to prevent the prodn. of harmful constituents in the exhaust gas.