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:
Jun. 17, 1997
Filed:
Oct. 21, 1996
Akihiro Nakagawa, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A misfire detecting apparatus for an internal combustion engine in which erroneous decision as to occurrence of misfire is prevented regardless of engine rotation speed variation pattern. The apparatus includes a crank angle sensor (4) mounted on a crank shaft (2) of the internal combustion engine (1) for generating a crank angle signal (.theta.) for every predetermined crank angle of the engine (1), a rotation-speed variation detector (21, 22) for detecting variation in rotation of the internal combustion engine (1) on the basis of the crank angle signal (.theta.), a misfire decision means (23A) for determining occurrence of misfire on the basis of the variation in the rotation speed of the engine (1), a rotation-speed variation pattern decision means (41) for deciding whether or not a rotation-speed variation pattern representing the variation of the rotation speed of the engine matches with a predetermined pattern which indicates resonance with a driving system operatively coupled to the internal combustion engine, and a misfire decision inhibit means (42) for invalidating the misfire decision means (23A) when matching is found between the rotation-speed variation pattern and the predetermined pattern.