PURPOSE: To detect knocking accurately, by giving the instruction of starting time of the conversion of a detected knocking signal into a digital value to an A-D converter, and judging the generating state of the knocking in correspondence with the digital value of the knocking signal.
CONSTITUTION: A detector 1 detects vibration, sounds, and the like of an engine due to knocking. The output of the detector 1 is inputted to a BPF2. The noise component is removed and the since wave with a knocking frequency in the vicinity of 8kHz is obtained. The result is inputted to a terminal AN of a one chip microcomputer 61, which includes an A-D converter 5 and a microcomputer 6. To the computer 61, an oscillator 62, a power source ON reset circuit 63, and a power source circuit 64 are connected. An ignition signal iGt is supplied to the computer 61 from an ignition time control circuit. The output of the computer 61 passes through a resistor ladder 69. After the D-A conversion, the result is sent to the ignition time control circuit by a voltage to current converter 68. The computer 6 controls the conversion starting time of the converter 5 and judges the generating state of the knocking in correspondence with the detected signal. Thus the accurate detection can be performed.
ITOU TERUYOSHI
HARAGUCHI HIROSHI
NARITA HIROSHI
IWATA TOSHIHARU
MATSUI TAKESHI
| JPS5748422A | 1982-03-19 | |||
| JPS5742822A | 1982-03-10 |