Being the fuel vapor neutron leakage detection device which detects the neutron leakage of the fuel vapor from the aforementioned

摘要

PROBLEM TO BE SOLVED: To provide a fuel vapor leak detecting device capable of suppressing seal leakage on closing a switching valve.;SOLUTION: A housing houses a pump 20 therein and includes a pump passage 13, a canister passage 14 and an atmosphere passage 12. A pressure sensor 40 detects pressure within the pump passage 13. A switching valve 30 is switched between a closed state and an opened state. In the closed state the switching valve is closed to shut off between the pump passage 13 and the canister passage 14 and release between the atmosphere passage 12 and the canister passage 14. In the opened state, the switching valve is opened to release between the pump passage 13 and the canister passage 14 and to shut off between the atmosphere passage 12 and the canister passage 14. When a shutoff pressure Ps is equal to or more than a first prescribed threshold value P1, an ECU 50 performs ON/OFF control of the switching valve 30 once or more and when the shutoff pressure Ps is smaller than the first prescribed threshold value P1, the ECU 50 performs fuel vapor leak detection.;COPYRIGHT: (C)2013,JPO&INPIT