| 摘要 |
PROBLEM TO BE SOLVED: To reduce power loss, and secure a purge flow even when differential pressure between intake pressure in an intake passage and pressure on a canister side is small. SOLUTION: Evaporated fuel absorbed by an absorbent 31 of the canister 30 is forcibly desorbed by driving of a purge pump 40, and is introduced in the intake passage 11 of the internal combustion engine 10. At that time, intake pulsation of the intake passage 11 of the internal combustion engine 10 is introduced in a driving chamber 41 of the purge pump 40 and a partition wall 43 is moved. Thereby, a ratio of volume of the pump chamber 45 becomes variable. That is, the purge pump 40 utilizes movement of the partition wall 43 brought about by introduction of the intake pulsation of the intake passage 11 of the internal combustion engine 10 to perform pumping operation so that the power loss is reduced. Furthermore, even when the differential pressure between the intake pressure in the intake passage 11 of the internal combustion engine 10 and the pressure on the canister 30 side is small, a desired purge flow rate corresponding to an operation state of the internal combustion engine 10 can be secured. |
