Patent ID: 7484501

Claim:
A fuel vapor treatment apparatus comprising: a first canister for removably absorbing fuel vapor produced in a fuel tank; a purge passage through which fuel vapor removed from the first canister is purged into an intake passage of an engine; a first detection passage communicating with the purge passage, the first detection passage having a throttle midway therethrough; a second canister located on an opposite side of the purge passage with respect to the throttle, the second canister communicating with the first detection passage for removably absorbing fuel vapor flowing from the purge passage into the second canister through the first detection passage; a second detection passage communicating with the second canister; a gas flow generating unit for generating gas flow by reducing pressure in the second detection passage; a pressure detecting unit for detecting pressure correlated with the throttle and the gas flow generating unit; an exhaust detecting unit for detecting exhaust of fuel vapor from the second canister to the second detection passage; and a purge control unit for controlling purge of fuel vapor from the purge passage to the intake passage in accordance with a detection result of the pressure detecting unit and a detection result of the exhaust detecting unit.