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:
Feb. 23, 1988
Filed:
Nov. 28, 1986
Michael R Verheyen, Peoria, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
The present invention pertains to a control system for igniting devices used in an internal combustion engine. In order to ignite alcohol fuel in a diesel engine, the fuel must be heated before or during compression. Glow plugs conveniently provide heat, but have a short life in such continuous applications. Glow plugs must be accurately controlled to prevent overheating, which leads to open-circuiting. Individual constant voltage controls attempt to provide this function, but are only moderately successful. They are costly and complex, and provide only moderate protection from overheating. Since glow plug resistance correlates to glow plug temperature, resistance control provides better protection against glow plug overheating. Therefore, an apparatus monitors the resistance of a single glow plug, and controls the resistance of each glow plug to a preselected resistance value. This preselected resistance value represents a glow plug temperature, that provides satisfactory fuel combustion combined with improved glow plug life. The principal use of the apparatus of the present invention is with internal combustion engines using alternate fuels.