Vaporized fuel purge controller for engine

摘要

A controller (40) for purging an optimal amount of vaporized fuel in accordance with the operating conditions of an engine (10). The controller presumes the flow rate of the purged gas to be that when a purge valve (35) is fully opened and uses the presumed value to calculate a target flow rate ratio. The controller then uses the target flow rate ratio and the actual intake pressure to calculate a duty ratio. This achieves a purged gas flow rate which compensates for a deviation that results from a characteristic of the purge valve. <IMAGE>