Patent ID: 6089210
Filing Date: 2000-07-18
Classification: F02D,F02M

Abstract:
An apparatus for controlling the air-fuel ratio of an internal combustion engine having a fuel tank, a canister for storing fuel evaporated from the fuel tank, and a release passage, connected to an intake side of the engine from the canister, for releasing fuel vapor stored in the canister together with air, the apparatus comprising:a flow control valve, mounted in the release passage, for varying an amount of purged air containing the fuel vapor;purge-executing means for causing the flow control valve to purge the fuel vapor and air according to an operating condition of the internal combustion engine;purge limit-forecasting means for forecasting, when purge is not executed, whether the amount of purged fuel vapor and air released to the intake system of the internal combustion engine as a result of the purge by the canister has reached one of an instantaneous purge limit value and a tolerated critical value; andpurge-inhibiting means for inhibiting execution of the purge when the purge limit-forecasting means forecasts that the purge limit will be reached.