Method of and an apparatus for misfire and rough road detection
First Claim
1. An apparatus for detecting misfire in a multi-cylinder internal combustion engine having an output shaft, said apparatus comprising comparing means for comparing engine output shaft speed variations following engine combustion events with a threshold value, distribution forming means for forming a distribution of numbers of the speed variations exceeding the threshold value with respect to the cylinders, and misfire signalling means for signalling a misfire when the numbers are predominantly distributed among less than a predetermined number of the cylinders.
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Accused Products
Abstract
Engine speed variations following combustion events within the cylinders of a multi-cylinder internal combustion engine are compared with a threshold during a predetermined number of combustion events. A distribution of speed variations exceeding the threshold with respect to the cylinders is formed. The distribution is analyzed to determine whether misfire is occurring, as indicated by speed variation following combustion occurring in half or less than half of the cylinders, or whether the vehicle is driving over a rough surface, as indicated by speed variation following combustion occurring in more than half of the cylinders.
18 Citations
28 Claims
- 1. An apparatus for detecting misfire in a multi-cylinder internal combustion engine having an output shaft, said apparatus comprising comparing means for comparing engine output shaft speed variations following engine combustion events with a threshold value, distribution forming means for forming a distribution of numbers of the speed variations exceeding the threshold value with respect to the cylinders, and misfire signalling means for signalling a misfire when the numbers are predominantly distributed among less than a predetermined number of the cylinders.
- 13. An apparatus for detecting movement of a vehicle driven by a multi-cylinder internal combustion engine over a rough surface, the engine having an output shaft, said apparatus comprising comparing means for comparing engine output shaft speed variations following engine combustion events with a threshold value, distribution forming means for forming a distribution of the numbers of the speed variations exceeding the threshold value with respect to the cylinders, and rough surface signalling means for signalling a rough surface when the numbers are distributed among more than a preset number of cylinders.
- 18. A method of detecting misfire in a multi-cylinder internal combustion engine having an output shaft, comprising comparing engine output shaft speed variations following engine combustion events with a threshold value, forming a distribution of numbers of the speed variations exceeding said threshold value with respect to the cylinders, and signalling a misfire when the numbers are predominantly distributed among less than a predetermined number of the cylinders.
- 24. A method of detecting movement of a vehicle driven by a multi-cylinder internal combustion engine over a rough surface, the engine having an output shaft, said method comprising comparing engine output shaft speed variations following engine combustion events with a threshold value, forming a distribution of numbers of the speed variations exceeding said threshold value with respect to the cylinders, and signalling a rough surface when the numbers are distributed among more than a preset number of cylinders.
Specification