| 摘要 |
PURPOSE:To increase the controlling precision of the titled device by detecting the starting speed of knocking, and thereby detecting accurately the strength of knocking without being affected by the ununiformity in the output characteristics of a knock sensor and by the difference in the detecting sensitivity between cylinders. CONSTITUTION:An output signal from a knock sensor 12 fitted on the cylinder block wall of an engine 11 and signals delivered from an igniter 13 at every 180 degrees and every one degree of a rotational angle of a crank are inputted in a knock control unit 14. The gate circuit 101 of a knocking detecting element 14A is turned ON in the range of the rotational angle of the crank wherein knocking occurs, based on a 180-degree signal and a 1-degree signal, and delivers only a knocking signal. This output is inputted in a differential circuit 103 via a band-pass filter and envelope circuit 102, and a signal obtained through differentiation therein is delivered as a knock strength signal via a half-wave rectifying circuit 104 and a compensating circuit 105. The igniter 13 is controlled by the knock strength signal via a knock strength determining element 14B and a delay angle control element 14C. |
