Air-fuel ratio control system for internal combustion engine

Abstract

Abstract PURPOSE:To prevent a torque shock at the time of selection from occurring, by controlling an air quantity in a throttle valve bypass passage with an air quantity to be related to an accelerator manipulated variable and a correction factor corresponding to a desired air-fuel ratio at the time of selecting it to the desired air-fuel ratio at the lean side according to the running state. CONSTITUTION:A control unit 50 operates a fundamental fuel injection quantity on the basis of a suction air quantity out of an air flow meter 22 and an engine speed out of a crank angle sensor 32. And, it performs water temperature correction based on the detected value of a water temperature sensor 31 and feedback correction to the desired air-fuel ratio based on a pump current of an oxygen sensor 33, etc. And, the control unit 50 sets the desired air-fuel ratio conformed to the suction air quantity and the engine speed, turning the value to the lean side at the specified driving area. And, at the time of selecting it to the lean side, an air correction factor is operated according to the desired air-fuel ratio, and with this correction factor and an air flow rate to be related to an accelerator manipulated variable, it operates and controls opening of an idle control valve 21.

Inventors

• 👤 Hatsuo Nagaishi
• 👤 初雄 永石
• 👤 Masaaki Uchida
• 👤 正明 内田

Bibliographic Details