An Experimental Study on Knock Sensing for a Spark Ignition Engine 931902
In this study to develop a knock sensor for a high power engine, spark timing is selected as a design parameter and the knock factors are examined for 4-cycle 4-cylinder engine with different spark timing.
Knocking occurrence crank angle, knocking pressure and knocking intensity are measured by a statistical method in which 10 data per 1 crank degree for 120 cycles are selected.
Since, knock sensor detects cylinder wall vibration and estimates pressure vibration in a combustion chamber, cylinder pressure and engine block vibration are detected by pressure transducer and acceleration sensor, respectively, and these two signals are analyzed by frequency analysis method and compared with theoretical knocking mode in the combustion chamber.
A design parameter of knocking sensor is determined by these results.