Evaporated fuel processing system

Abstract

When a leakage fault occurs in the evaporated fuel processing system of a fuel tank, a control system reliably prevents leakage of the evaporated fuel from the point where the leakage fault has occurred. The fuel tank and a canister are connected to each other via a charge passage having a bypass valve, and the canister and an intake passage of an engine are connected to each other via a purge passage having a purge control valve. When a leakage fault occurs in the fuel tank (or the charge passage upstream of the bypass valve), the bypass valve and the purge control valve are opened and an atmosphere release control valve provided on the canister, is closed. The closure of the atmosphere release control valve stops the negative intake pressure of the engine from being consumed by the intake of air through the atmosphere release control valve, and thus it is possible to efficiently prevent the evaporated fuel from leaking from the point where the leakage fault has occurred by effectively transmitting the negative intake pressure to the point where the leakage fault has occurred.

Dependencies are inferred from the claim text.