Air-fuel ratio control method for internal combustion engine

Abstract

Abstract PURPOSE:To stabilize air-fuel ratio by arranging a solenoid valve in a path communicating between a canister and an intake path in the downstream of a throttle valve, and resetting correction variables to ineffective values which substantially cause no variation on the fuel supply quantity, as required, when the solenoid valve is switched. CONSTITUTION:A fuel tank 25 communicates through a purge path 26 arranged with a canister 28, with an intake path 12 in the downstream of a throttle valve 18. Here, a purge control valve 30 is arranged in the purge path 26. An electronic control unit 16 controls a solenoid 30d in the valve 30 based on signals being fed from various sensors 14, 19-24 for detecting operational conditions of an engine 10 so as to open/close a valve body 30c. If open/close operation of the valve 30 is executed during feedback control operation of air-fuel ratio, correction variables are reset to ineffective values which cause substantially no variation of the fuel supply quantity even if fuel supply quantity is corrected, when the valve 30 is switched.

Inventors

• 👤 Toyoaki Fukui
• 👤 豊明 福井
• 👤 Yoshitaka Yoshida
• 👤 吉田　義孝
• 👤 Nobuyuki Tanaka
• 👤 信行 田中

Bibliographic Details