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:
May. 09, 2000
Filed:
Nov. 29, 1994
Hitachi, Ltd., Tokyo, JP;
Abstract
A prescribed threshold level Dth for misfire judgment for each cylinder is recorded in a misfire judgment level retaining means 102 of a misfire judgment processing section 100. A combustion state parameter operation means 106 measures revolution speed of a multi-cylinder engine for each cylinder, and attains as a combustion state parameter a differential in revolution speed between a specific cylinder and other cylinders. In a misfire judgment level correction means 104, a plurality of combustion state parameters concerning the specific cylinder is attained, and the above-mentioned threshold level Dth is corrected as a function of the parameter. A misfire judgment processing means 108 compares the combustion state parameter with the threshold level Dth and diagnoses a combustion state in the specific cylinder. Namely, the corresponding cylinder is judged to be misfire when the combustion state parameter of the specific cylinder exceeds the prescribed parameter.