Air fuel ratio detecting device

Abstract

Abstract PURPOSE:To improve the detection accuracy of an air fuel ratio by correcting a coefficient of calibration according to the time of the start of a fuel cut to fuel cut recovery. CONSTITUTION:An air fuel ratio means (a) detects the oxygen concentration in exhaust gas and a fuel cut detecting means (b) detects the fuel cut state of an engine. Then, the detection outputs of the means (a) and (b) are inputted to a calibration quantity arithmetic means (c) and the calibration quantity of the normal output of the means (a) is computed based on the output of the means (a) when the pressure in an exhaust pipe is the atmospheric pressure. Then, a correcting means (d) corrects a calibration quantity with the fuel cut state detection output of the means (b) and the calibration quantity of the means (c) according to the fuel cut continuance from the start of the fuel cut to the recovery. Then, an air fuel ratio arithmetic means (e) corrects the normal output of the mean (a) based on the calibration value from the means (d) to calculate the air fuel ratio. The accuracy of the calibration of the sensor output is improved and the detection accuracy of the air fuel ratio is improved.

Inventors

• 👤 Yukimasa Kai
• 👤 志誠 甲斐
• 👤 Toyoaki Nakagawa
• 👤 豊昭 中川

Bibliographic Details