AIR-FUEL RATIO CONTROL DEVICE

• Main Author: IWAKURA YOICHI
• Format: Patent
• Language: English
• Published: 19.02.1988
• Subjects: BLASTING; COMBUSTION ENGINES; CONTROLLING COMBUSTION ENGINES; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MECHANICAL ENGINEERING; WEAPONS

PURPOSE:To improve the consumption of fuel by changing the delay time for a lean or rich judgment so that the air-fuel ratio comes to the rich side when the temperature of catalytic converter rhodium exceeds a set value, so as to achieve the attainment of leanness within the range not to overheat the catalytic converter rhodium. CONSTITUTION:An air-fuel ratio judging means 18 judges whether the air-fuel ratio of mixture a given delay time is lean or rich, on the basis of the signal from an O2 sensor 1 which detects the oxygen content in exhaust gases. An air-fuel ratio adjusting mechanism 4 controls the air flow rate to an air bleed passage 6 via a flow control valve 8 on the basis of the signal from the air-fuel ratio judging means 18. A catalyst temperature judging means 21 judges whether the temperature of catalytic converter rhodium 3a has exceeded a set value of not, on the basis of the detected value of a catalyst temperature sensor 26. An air-fuel ratio control correcting means 19 changes the delay time so that the air-fuel ratio comes to the rich side when the temperature of catalytic converter rhodium 3a exceeds a set value.