Leak check apparatus for fuel vapor purge system
AssigneeDenso Corporation
InventorsMasao Kano, Nobuhiko Koyama
Life of this patent
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Abstract
A fuel vapor purge system has a canister and a pump on a purge line arranged between the canister to the intake passage. The system further has a sub-canister on a branch passage of the purge line. The pump is driven when the engine is stopped, and reduces an inside pressure of the system. The vapor discharged from the pump is adsorbed in the sub-canister, therefore, no vapor is emitted to the atmosphere. The controller checks a leak by monitoring the inside pressure after the inside pressure is reduced. It is possible to improve an accuracy of the leak detection since a leak check is executed when the engine is stopped.
Claims6
A leak check apparatus for a fuel vapor purge system having a fuel tank, a main canister for adsorbing fuel vapor in the fuel tank and a purge passage for purging the adsorbed vapor to an intake passage of an engine, the apparatus comprising:
- at least one valve which defines a closed space including the fuel tank, the main canister and at least a part of the purge passage;
- a pump which discharges gaseous component in the closed space for reducing an inside pressure of the closed space;
- a sub canister disposed in series to the pump which adsorb the vapor in the gaseous component discharged by the pump;
- and
- a sensor which outputs a signal indicative of a leak on the closed space.
Dependencies are inferred from the claim text.