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. 29, 2010
Filed:
Aug. 09, 2005
Yoshiyuki Fukumura, Osaka, JP;
Mitsuhiro Izumi, Osaka, JP;
Shinobu Sugisaki, Osaka, JP;
Tsutomu Kusuhara, Osaka, JP;
Yoshiyuki Fukumura, Osaka, JP;
Mitsuhiro Izumi, Osaka, JP;
Shinobu Sugisaki, Osaka, JP;
Tsutomu Kusuhara, Osaka, JP;
Diamond Electric MFG. Co., Ltd., Osaka-Shi, JP;
Abstract
An ion current detecting apparatus includes a capacitor C that is charged as a spark plugdischarges, a Zener diode ZD that limits a maximum voltage of the capacitor C while charging, a detection resistor Rthrough which a discharge current of the capacitor C flows, and a comparator circuitthat compares a current value of the detection resistor Rwith a predetermined value. A charge quantity Q of the capacitor C at discharge start is set so that, as a consequence of a discharging operation of the capacitor C, discharge duration required until the current value of the detection resistor Rfalls below the predetermined value becomes longer than time duration in which the ion current generated by fuel combustion in the engine combustion chamber lasts. The ion current detecting apparatus automatically detects degradation in an insulation resistance in the spark plug, ensuring normal operation in engine control.