Method of purging fuel vapor

Abstract

Abstract PURPOSE:To remove fuel vapor without impairing exhaust emission and driving characteristics in idling by purging the fuel vapor in running other than the idling when detected residual fuel exceeds a predetermined amount and in the idling when same is less than the predetermined amount. CONSTITUTION:Residual fuel in a fuel tank 7 is measured by a fuel gauge 29 and when it exceeds a predetermined amount, an electromagnetic valve 21 is closed and a fuel vapor extracting port 9 in a canister 1 communicates only to a purge port 17. And by intake negative pressure near the purge port 17 in running other than idling is purged fuel vapor in the canister 1 to an intake path 15. Also, when the residual fuel is less than the predetermined amount, the output of a comparator 33 is reversed to high level to open the electromagnetic valve 21 and set pressure near a purge port 25 to negative pressure even in idling. Thus, when the residual fuel is less than the predetermined amount and fuel vapor is rich, the fuel vapor is purged from the port 25 to an intake path 23 even in idling to ensure a desired purge flow.

Inventors

• 👤 Shigeru Sasaki
• 👤 茂 佐々木
• 👤 Tatsu Fujita
• 👤 藤田　達

Bibliographic Details