Patent · US Expired

Misfire detector for internal combustion engines

US7243532B2 · kind B2 · utility

15Cited by
8References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 2, 2004
Grant dateJul 17, 2007
Priority date
Expiry dateDec 2, 2024

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01M15/11
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.