Air fuel mixture regulator for exhaust gas thermal reactors - fuel supply is varied by engine working conditions

摘要

Exhaust system contains a combustion chmber to complete the oxidisation of unburnt hydro carbons. The chamber has additional air feed which joins an auxiliary fuel feed pipe at a switch over valve which may isolate either or both auxiliary feeds by means of an engine working condition dependent electro magnet. An exhaust oxygen content sensor whose end is surrounded by a heater coil gives a signal to the fuel metering unit to correspondingly increase or decrease the fuel delivery. The spiral winding on the oxygen sensor receives current from a temp. regulator dependend upon the output from a temp. sensor fitted in the immediate proximity of the oxygen sensor in order to ensure a high working temp. when the exhaust gas is relatively cool.