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:
Jul. 18, 2000
Filed:
Jul. 10, 1997
Yasuhiro Takahashi, Tokyo, JP;
Wataru Fukui, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A combustion state detecting apparatus for an internal-combustion engine improves the signal-to-noise ratio of an ionic pulse signal to achieve good interfacing characteristic, high detection accuracy, and high control reliability without adding to cost. An electronic control unit (2A) which detects the combustion state in a spark plug according to an ionic pulse signal (Gi) includes: an edge detecting circuit (36) for detecting an end edge of an ionic pulse contained in the ionic pulse signal in a detection zone from a second reference crank angle to a first reference crank angle; a level detecting circuit (37) for detecting the level of the ionic pulse signal at the first reference crank angle; and a circuit (38) for determining the combustion state of the internal-combustion engine according to a detection result (Ni) received from the edge detecting circuit and a detection result (Li) received from the level detecting circuit. Thus, an ionic current detection signal can be pulsed using a simple circuit configuration, and the simple determining logic is used to reduce the load on the arithmetic processor of the electronic control unit.