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:
May. 25, 1993
Filed:
Sep. 23, 1992
Takanori Fujimoto, Himeji, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A misfire sensing apparatus for an internal combustion engine can determine an occurrence of misfiring in any of engine cylinders as well as which cylinder is misfiring with improved accuracy and reliability. A crank angle sensor 11 generates an output signal at predetermined crank angles of the engine. A control unit 20 identifies operating states of the cylinders based on the output signal from the crank angle sensor. It successively senses misfire information in the form of the number of revolutions per minute of the engine at the predetermined crank angles, and determines possible misfiring in a cylinder when a difference between the current misfire information and the previous one is greater than a predetermined level. When there is possible misfiring in a cylinder, the control unit adjusts an engine operating parameter by a predetermined value, compares misfiring information as sensed before and after the adjustment, and determines an occurrence of true misfiring if a difference in the misfiring information before and after the adjustment is less than a predetermined reference value. In one form, the control unit decreases, upon occurrence of possible misfiring in a cylinder, an amount of fuel supplied to that cylinder so as to cause intentional misfiring therein. In another form, the control unit stops, upon occurrence of possible misfiring in a cylinder, firing of a spark plug for that cylinder.