| 摘要 |
PURPOSE:To quickly avoid knocking even in the low rotational speed range of an engine and also make a knocking avoiding speed constant, by increasing or decreasing the amount of knocking correstion depending on the operational state of the engine. CONSTITUTION:Basic ignition timing is computed in a control unit 38. Then an amount of knocking correction, i.e., angles of advancing or retarding, is selected by a CPU 38b for searching out a table value stored in a memory 38c based on the number of revolution of an engine detected by a crank angle sensor 20. Here, the amount of knocking correction is determined depending on the number of revolution of the engine, the amount of correction bar ingnition being comparatively large in a low speed range and becoming smaller as the number of revolution of the engine increases. Whether knocking is present or not is confirmed by the output of a knocking sensor 14, and if knocking is present, the angle of ignition is retarded by the above amount of knocking correction. As described above, the amount of correction is varied depending on the engine number of revolution, enabling smooth knock avoiding to be assured. |
