Device for controlling operation of fuel evaporative purge system of an internal combustion engine

摘要

A device for controlling a fuel evaporative purge system having a solenoid valve arranged in a purge passage, comprises a unit for determining a maximum amount of fuel vapor to be purged, an air flow meter, a unit for calculating a maximum purging ratio of the maximum amount of fuel vapor to an amount of intake air, a unit for setting a purging ratio which is gradually varied during the purging process, and a unit for activating the solenoid valve. In the purging operation, the activating unit drives the valve at a duty-ratio identical to a ratio of the purging ratio to the maximum purging ratio.