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. 26, 1998
Filed:
Jan. 27, 1997
Donald R Haefner, Troy, MI (US);
Joseph S Mazur, Livonia, MI (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A misfire detection system and method for use in conjunction with an internal combustion engine. An engine cylinder has a pressure sensor disposed therein for providing a signal indicative of the pressure in the cylinder's combustion chamber. Compression pressure measurements are obtained at crankshaft angles reached prior to the top dead center position of piston travel. For crankshaft angles greater than that at which top dead center is reached, the pressure measurements are reflected about a vertical axis extending through the top dead center point. The reflected compression pressures for crankshaft angles reached after the top dead center point are subtracted from the actual compression chamber measurements obtained over those crankshaft angles during the power stroke of the engine. The difference values are integrated over a range of crankshaft angles to produce a difference pressure integral which is normalized through multiplication by an optional factor and then subsequent division by the maximum pressure occurring in the compression chamber during the engine's power stroke. The resulting normalized integral value is compared to a threshold, below which partial or complete engine misfire is presumed.