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. 24, 1986
Filed:
Jul. 31, 1985
Philip A Karau, Anderson, IN (US);
Anthony L Marks, Anderson, IN (US);
James H Currie, Rochester, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
An LPP ignition timing control for an internal combustion engine of the type having a normal combustion mode characterized by combustion pressure peaks compatible with closed loop LPP ignition timing control and an abnormal combustion mode which may not be so compatible includes a closed loop control apparatus effective to sense LPP in the combustion chamber, generate an LPP value therefrom, store a DLPP value indicative of a desired LPP, and compare the LPP value and stored DLPP value and adjust ignition timing to reduce the difference therebetween. During a sensed abnormal combustion mode, the control changes the ignition timings for ignition events toward predetermined, stored ignition timings and substitutes for the stored DLPP value temporary DLPP values which are a predetermined crankshaft angle in advance of the generated LPP values and limited in the retard direction to the stored DLPP value. After the termination of the abnormal combustion mode the control continues the substitution of the temporary DLPP values for the stored values until the former comes within a predetermined crankshaft angle of the latter. The abnormal combustion mode may be sensed as excessive variation in LPP, excessively advanced average LPP or excessive numbers of undetected combustion pressure peaks.