FUEL VAPOR PROCESSING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a fuel vapor processing apparatus capable of controlling the purge flow rate on the low flow rate side with high accuracy and ensuring a large purge flow rate. SOLUTION: A first purge control valve 33 is provided on a first purge passage 18 to communicate a canister 13 with the downstream side of a throttle valve 6 of an intake system 5. A bypass passage 20 to bypass the throttle valve 6 is connected to the upstream side and the downstream side of the throttle valve 6 of the intake system 5. A second purge passage 19 is branched from the downstream side of the first purge control valve 33 of the first purge passage 18 via a branched part 21, connected to the bypass passage 20 via a connection part 22. A second purge control valve 34 is provided on the downstream side of the branched part 21 of the first purge passage 18. The bypass passage 20 has first and second throttling parts 23 and 24 to throttle at least a part thereof on the downstream side and the upstream side of the connection part 22 to a passage area smaller than that of the first purge passage 18. COPYRIGHT: (C)2005,JPO&NCIPI