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:
Jan. 21, 2003
Filed:
Feb. 27, 2001
Satoru Osaki, Hitachinaka, JP;
Toshio Hori, Hitachinaka, JP;
Osamu Matsuno, Yokohama, JP;
Takeshi Tsuyuki, Ayase, JP;
Other;
Abstract
To provide a failure diagnosis apparatus for an exhaust gas recirculation system which is capable of eliminating the influence of various disturbance factors that vary the suction air pressure, diagnosing a failure of the exhaust gas recirculation system on the basis of the suction air pressure, and preventing wrong diagnosis. A failure diagnosis apparatus for an exhaust gas recirculation system consists of a fresh air pressure estimating device for calculating an estimated fresh air pressure inside a suction pipe from the operating condition of an internal combustion engine, an actual EGR (exhaust gas recirculation) gas pressure estimating device for estimating an EGR gas pressure on the basis of a measured suction pipe pressure detected by a suction pipe pressure detecting device and an estimated fresh air pressure calculated above, and a failure judging device for judging the failure on the basis of the estimated EGR gas pressure and the detected operating condition.