| 摘要 |
PROBLEM TO BE SOLVED: To precisely control the purge flow rate by providing a plurality of purge passages in parallel, interposing a purge control valve in each purge passage, and providing a purge flow rate control means for independently controlling a plurality of purge control valves, thereby controlling the purge flow rate to a target purge flow rate. SOLUTION: In the operation of an internal combustion engine 1, a target purge flow rate is calculated on the basis of engine speed, the intake air quantity, and throttle opening in a control unit 20, and the target flow rate of each purge control valve 15a, 15b is determined according to the target purge flow rate. Namely, the large-sized purge control valve 15a with relatively low resolution takes, as the target flow rate, the maximum flow rate controllable by the purge control valve 15a in a flow rate area less than the target purge flow rate at that time. On the other hand, the target flow rate of the small-sized purge control valve 15b with relatively high resolution is determined so as to supply the deviation between the target purge flow rate and the flow rate controlled by the purge control valve 15a.
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