| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a direct-injection engine or an engine mounted on a hybrid vehicle has a throttle valve often largely opened during operation and an inlet pipe subjected to low negative pressure to provide insufficient capability for recovering an evaporating fuel absorbing canister, which should be supplemented. SOLUTION: A second purge line 27 opening to a suction port 8 of each cylinder is provided for purging the canister 18. Numeral 24 is a first purge line opening to a common inlet pipe 12, numeral 23 is a first purge valve and numeral 28 is a second purge valve. Since an inlet port 8 of each cylinder has inlet negative pressure higher than the inlet pipe 12 during an intermediate or high load, high purging capability is established in this condition. During a low-load operated condition such as idling, the first purge line 24 is utilized as conventional. By providing one-way valves in the purge lines 24, 27, canister purging operations are performed in the order of the line having higher negative pressure and the maximum purge flow is therefore provided when both of them operate together. |
