Air-fuel ratio control for car engine

Abstract

Abstract PURPOSE:To prevent the erroneous operation in air-fuel ratio control by suspending the taking-in of the learned values due to the information supplied from an O2 sensor when the P-P value (difference between the max. and the min. values of the O2 sensor within a prescribed time) of the output voltage of the O2 sensor is below a prescribed value. CONSTITUTION:When an engine 1 is in operation, a microcomputer 15 corrects the fundamental injection amount Tp calculated on the basis of the inhaled air amount Q detected by an air-flow meter 17 and the number of revolution N detected by a crank-angle sensor 21 on the basis of the data such as those of an O2 sensor 16 and a water-temperature sensor 19 and controls an injector 4 according to the corrected fuel injection amount Tp'. In this case, the deterioration of the O2 sensor 16 is judged by judging if the P-P value of the O2 sensor 16 becomes below a prescribed value or not. For example, the max. and min. values of the output voltage of the O2 sensor 16 within a prescribed time are obtained, and when the difference between the both values becomes below a prescribed value, it is judged that the O2 sensor 16 is deteriorated, and then taking-in of the learned values according to the information supplied from the O2 sensor 16 is suspended.

Inventors

• 👤 Kunihiro Abe
• 👤 邦宏 阿部
• 👤 Yoshitake Matsumura
• 👤 松村　吉剛
• 👤 Takuro Morozumi
• 👤 両角　卓郎

Bibliographic Details