| 摘要 |
PURPOSE:To reduce the NOx emission quantity and to avoid shortage of torque at the time of acceleration by controlling the purge gas introduction quantity according to the knock intensity during lean operation. CONSTITUTION:A knock intensity obtained by a knock sensor 24 is compared with a designated value 1 by a control unit 16 to determine whether it is during lean operation or not. Knock is controlled to retard ignition timing by a designated value, and a target opening PVO of a purge control valve 15 is calculated. The opening of the purge control valve 15 is controlled to control the evaporated fuel introduction quantity so that the knock intensity is near the designated value. Whether the opening of the purge control valve 15 is throttled to the minimum or not is determined from whether PVO<=PVOmin or not, and if the opening of the purge control valve 15 is throttled to the minimum, ignition timing is retarded by a designated value. |
