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:
Apr. 12, 2005
Filed:
Oct. 30, 2003
Akio Matsunaga, Susono, JP;
Hidenobu Nakamura, Chita, JP;
Akio Matsunaga, Susono, JP;
Hidenobu Nakamura, Chita, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Denso Corporation, Kariya, JP;
Abstract
An EGR-gas flow rate estimation apparatus for an engine including an exhaust circulation pipe connected between an exhaust passage and an intake passage of the engine, and an EGR control valve interposed in the exhaust circulation pipe and having a throttle portion. The apparatus estimates a provisional EGR gas flow rate Gegrby use of a general formula Gegr=Aegr·(2·Pex·ρa)·Φ (Φ=(((κ/(κ−1)·((Pb/Pex)−(Pb/Pex)))) where Pup represents the exhaust pressure, Pb represents the intake pressure, Aegr represents the effective opening area of the throttle portion, ρa represents the density of EGR gas, and κ represents the specific heat ratio of EGR gas. Subsequently, the apparatus estimates the flow rate Gegr of EGR gas flowing into the intake passage, by multiplying the provisional EGR gas flow rate Gegrby a correction value dPgain corresponding to differential pressure (Pex−Pb).