US Patent 7243532 Misfire detector for internal combustion engines

Patent 7243532 was granted and assigned to Denso on July, 2007 by the United States Patent and Trademark Office.

Overview Structured Data Issues Contributors Activity

Is a

Patent

Patent attributes

Current Assignee

Denso

Patent Jurisdiction

United States Patent and Trademark Office

Patent Number

72435320

Date of Patent

July 17, 2007

Patent Application Number

110016470

Date Filed

December 2, 2004

Patent Primary Examiner

‌

Edward Lefkowitz

Patent abstract

Air fuel ratios of exhaust gases of respective cylinders are estimated based on a detection value of an air fuel ratio sensor mounted in an exhaust-collector. Normal combustion and misfire are determined depending upon whether individual cylinder air fuel ratios of the respective cylinders are within a normal combustion range. Then, whether a fuel system causes misfire is determined based on a difference between an actual injection quantity of the misfire cylinder and an average value of actual injection quantities of all the cylinders. Whether an air system causes misfire is determined based on a difference between an estimated air quantity of the misfire cylinder and an average value of actual air quantities of all the cylinders.