| 摘要 |
<p>An evaporated fuel processing device using a canister (3), comprising a purge control valve (23) and a drain cut valve (26), and also comprising a shutoff valve (21) for switching between allowing and preventing communication between a fuel tank (2) and the canister (3). The shutoff valve (21) is composed of a normally-closed electromagnetic valve, and is open only when oil is being supplied. When a purge process is being executed, the fuel component concentration of a purge gas is detected based on an air-fuel ratio sensor (32), and if the fuel component concentration of the purge gas is richer than standard, the shutoff valve (21) is determined to be in opening failure. When the purge process is being executed, if the shutoff valve (21) is in opening failure, intake negative pressure acts on the fuel tank (2), and evaporated fuel increases and can therefore be reliably detected.</p> |
