Patent Number: 7,762,126

Title: Leakage diagnosis apparatus and method for diagnosing purge apparatus for internal combustion engine

Abstract: A leakage diagnosis apparatus is applied to a purge apparatus of an internal combustion engine. The purge apparatus includes a canister accommodating an adsorbent for temporarily absorbing fuel vapor produced in a fuel tank. The fuel vapor is desorbed from the adsorbent and purged into an intake passage of the internal combustion engine. A diagnosis unit performs a leakage diagnosis to detect leakage in the purge apparatus. A state measurement unit measures a fuel vapor state of mixture containing the fuel vapor, which is desorbed from the adsorbent. A command unit commands the diagnosis unit to perform the leakage diagnosis at a predetermined time. An evaluating unit evaluates the leakage diagnosis to be performed in an appropriate state on the basis of a change between the fuel vapor state before the leakage diagnosis and the fuel vapor state after the leakage diagnosis.

Inventors: Shibuya; Hisatoshi (Handa, JP)

Assignee: Denso Corporation

International Classification: G01M 15/00 (20060101); F02M 33/02 (20060101); F02M 33/04 (20060101); F02B 77/08 (20060101)

Expiration Date: 7/27/12018