초록 ▼

A system and method in which the exhaust manifold pressure is measured by a single gauge-type pressure sensor positioned in the exhaust manifold to detect misfires in all cylinders of an internal combustion engine. The pressure sensor detects the exhaust manifold pressure and feeds a signal to a mic

A system and method in which the exhaust manifold pressure is measured by a single gauge-type pressure sensor positioned in the exhaust manifold to detect misfires in all cylinders of an internal combustion engine. The pressure sensor detects the exhaust manifold pressure and feeds a signal to a microcomputer via an analog-to-digital converter. A data processing device monitors the pressure waveform created by the data from the sensor to determine if a full or partial misfire occurs. If a cylinder suffers from a partial or complete misfire, the strength of the pressure pulse for that cylinder will be reduced, thus, allowing the data processing device to identify the misfire. The data processing device may determine a misfire by computing an average peak pressure for each combustion cycle, a pressure threshold as a function of engine speed and fuel consumption rate, and a minimum pressure value based on the difference between the average peak pressure and the pressure threshold. The data processing device may alternatively determine a misfire by first computing a coefficient of variation between an observed pressure pulse and the average peak pressure and then comparing the coefficient of variation with a pressure threshold to determine if at least a partial misfire has occurred.

대표청구항 ▼

[ What is claimed is:] [1.]1. A system for detecting an engine cylinder misfire in an internal combustion engine comprising:pressure sensing means mounted in an exhaust manifold of the internal combustion engine for sensing the peak pressure of the exhaust gas flowing through said exhaust manifold;e

[ What is claimed is:] [1.]1. A system for detecting an engine cylinder misfire in an internal combustion engine comprising:pressure sensing means mounted in an exhaust manifold of the internal combustion engine for sensing the peak pressure of the exhaust gas flowing through said exhaust manifold;engine operation detecting means for detecting operating characteristics of the internal combustion engine, said operating characteristics including at least one of the rotational speed, fuel consumption rate and coolant temperature of the internal combustion engine; anddata processing means connected with said engine operation detecting means and said pressure sensing means for receiving the sensed pressure from said pressure sensing means for calculating a minimum pressure value based on the values of said operating characteristics measured by said engine operation detection means and for comparing said sensed pressure with said minimum pressure value to determine if an engine cylinder misfire has occurred.