The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 24, 2004
Filed:
Nov. 27, 2002
Satoru Osaki, Hitachinaka, JP;
Toshio Hori, Hitachinaka, JP;
Osamu Matsuno, Yokohama, JP;
Takeshi Tsuyuki, Yokohama, JP;
Other;
Abstract
A failure diagnosis apparatus for an exhaust gas recirculation system eliminates the influence of various disturbance factors that vary the suction air pressure, diagnoses a failure of the exhaust gas recirculation system on the basis of the suction air pressure, and prevents incorrect diagnosis. The system includes a fresh air pressure unit for determining an estimated fresh air pressure inside a suction pipe from the operating condition of an internal combustion engine and an actual exhaust gas recirculation pressure estimating unit for determining an EGR gas pressure on the basis of a measured suction pipe pressure detected by a suction pipe pressure detecting unit and estimated fresh air pressure. A failure is judged on the basis of the estimated EGR gas pressure and the detected operating condition.