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. 29, 1995
Filed:
Feb. 21, 1995
David L Vossen, Kalamazoo, MI (US);
James T Walters, Kalamazoo, MI (US);
SPX Corporation, Muskegon, MI (US);
Abstract
This invention relates to a method and apparatus for diagnosing faulty cylinders in internal combustion engines. A probe produces a signal that is representative of the instantaneous angular velocity of the engine shaft. A Percent Power Contribution (PPC) parameter is computed by substracting the square of the instantaneous angular velocity at the beginning of a cylinder period from the square of the instantaneous angular velocity at the end of that cylinder's period and dividing this difference by the square of the average engine angular velocity. A value of this PPC parameter significantly less than zero indicates a faulty cylinder. An Average Energy Percent parameter (AEP) is computed by dividing the squares of the sampled instantaneous angular velocity values summed over a cylinder period by the number of samples in that period and by the square of the average engine angular velocity. A value of this AEP parameter significantly less than one indicates the previous cylinder in the firing order is faulty. The two parameters can be used independently or in combination to diagnose continuous and transient engine faults. Faulty cylinder indications are displayed on a monitor or communicated to an operator.