JPS5768559A - Apparatus for inspecting and preventing knocking - Google Patents

Abstract

PURPOSE:To facilitate check of knock-detecting function, by operating an engine under an ignition timing advanced over the ordinary ignition timing with feedback function by knock signals being stopped, and thereby causing knock positively at the time of checking the knock-detecting function. CONSTITUTION:A control unit 2 detects the operational conditions of an engine from output signals of various sensors 5 by means of a detecting circuit 6 and gives an ignition signal to an ignition coil 3 via an ignition timing controlling circuit 7. Further, when knocking is detected by a knock detecting circuit 9 from the output signal of a knock sensor 8, the control unit 2 applies an output signal to a circuit 10 for controlling retard at the time when knocking is caused and corrects the above ignition signal. In the about arrangement, a knock detecting function checking circuit 11 for rendering the above circuit 10 inoperative and producing from the circuit 7 an ignition signal of an ignition timing advanced a prescribed degree from the ordinary timing when a knock detecting function checking switch 12 is turned ON is further provided to light a lamp of a knock detecting monitor 13 when knock is detected.