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. 31, 1993
Filed:
Jan. 04, 1991
Yutaka Takaku, Katsuta, JP;
Mineo Kashiwaya, Katsuta, JP;
Toshio Ishii, Katsuta, JP;
Naoyuki Tanaka, Tsuchiura, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A method and apparatus for detecting the quality of combustion in each cylinder of a multi-cylinder internal combustion engine is disclosed. The invention determines a combustion stroke of each cylinder by sensors and detects the rotational speed of the engine at least three times during each combustion stroke by a rotation speed calculation device. The detected rotational speeds are evaluated by an arithmetic calculation device to identify the variation in rotational speed of each piston during a combustion stroke whereby the quality of combustion is, thus, determined. In a feature of the invention fluctuations in rotational speed caused by reciprocating inertia (.omega..sub.c) are calculated and eliminated from fluctuation in engine speed caused by combustion (.omega..sub.g) so that the quality of combustion based only upon variation in detected speeds caused by combustion is derived.