Nissan Motor Company Limited

Isao Otsu

Shinsuke Takakura

An evaporated fuel processing apparatus includes a blocking valve configured to selectively allow and shut off communication between a canister and a fuel tank, and adsorbs evaporated fuel by the canister by opening the blocking valve during fuel filling, wherein the evaporated fuel occurs in the fuel tank, and performs a purge operation of introducing purge gas into an intake air line of an internal combustion engine with the blocking valve closed while the internal combustion engine is operating, wherein the purge gas contains a fuel component released from the canister. A diagnostic apparatus is configured to diagnose whether or not the blocking valve is abnormal, based on sensing of evaporated fuel flowing through the blocking valve while the purge operation is being performed.

Device and method for diagnosing evaporated fuel processing device

An evaporated fuel processing apparatus includes a valve between a canister and a fuel tank, and adsorbs evaporated fuel by the canister during fuel filling, and introduces into an intake air line of an internal combustion engine and processes the evaporated fuel while the internal combustion engine is operating. A diagnostic apparatus includes: a pump for pressurizing a system including the fuel tank and the canister; and a pressure sensor for sensing an internal pressure of the system. The diagnostic apparatus diagnoses whether or not leakage is present, based on a change in the internal pressure of the system from a pressurized state, wherein the pressurized state is a state pressurized to a predetermined pressure for diagnosis that is higher than a tank pressure at start of diagnosis; and maintains the fuel tank in the pressurized state by closing the valve after termination of the diagnosis.

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Sagamihara, Japan

Isao Otsu