APPARATUS FOR DETECTING KNOCKING OF ENGINE

摘要

PURPOSE:To accurately detect knocking, by a method wherein the reference values of the vibration levels at the combustion and non-combustion periods of an engine are formed and the former is compared with a detected vibration level at the time of the steady operation of the engine and the latter is compared with the detected vibration level at the time of the accelerated operation of the engine. CONSTITUTION:An engine 1 is equipped with a knocking detection circuit 23 cooperating with a controller 22. The signal of a knocking sensor 20 inputted to the circuit 23 is processed by a filter to select only frequency of a predetermined range. The controller 22 discriminates a combustion state and a non- combustion state on the basis of the signal from a crank angle sensor 21 and controls the circuit 23 to form the reference values of the vibration levels in both states. Next, the operated state of the engine is judged and the vibration level of a combustion period is compared with the reference value in steady operation and the vibration level of a non-combustion period is compared with the reference value in a transition state such as accelerated operation to detect knocking.