DEVICE AND METHOD FOR DIAGNOSING EVAPORATED FUEL PROCESSING DEVICE

摘要

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.

主权项

1. A diagnostic apparatus for an evaporated fuel processing apparatus, wherein the 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 during fuel filling, wherein the evaporated fuel occurs in the fuel tank, and introduces into an intake air line of an internal combustion engine and processes the evaporated fuel while the internal combustion engine is operating, the diagnostic apparatus comprising:
a pump configured to pressurize an inside of a system, wherein the system includes the fuel tank and the canister; and at least one pressure sensor configured to sense an internal pressure of the system; wherein the diagnostic apparatus is configured to:
diagnose 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; andmaintain an inside of the fuel tank in the pressurized state by closing the blocking valve after termination of the diagnosis.