| 摘要 |
<p>ENGINE WITH DUAL SENSOR CLOSED LOOP FUEL CONTROL In a closed loop fuel control system for an internal combustion engine having a catalytic converter in its exhaust system, a first zirconia sensor in the exhaust system upstream from the catalytic converter generates a signal indicative of air-fuel ratio in gases before catalytic treatment, a second zirconia sensor in the exhaust system downstream from the catalytic converter generates a signal indicative of air-fuel ratio in gases after catalytic treatment and a cascade feedback control system including both zirconia sensors controls the rate of flow of fuel or air to the engine in response to both sensor signals and a reference to maintain a constant stoichiometric air-fuel ratio in the exhaust system for maximum catalytic converter efficiency in simultaneous oxidation and reduction. The engine fuel system reverts to open loop operation during wide open throttle, closed throttle and cold start operation.</p> |
