| 摘要 |
PURPOSE:To permit knocking of respective cylinders to be sensed accurately, by increasing a number of samplings for cylinders of which knocking accuracy sensed is bad by means of a knocking sensor provided commonly with a plurality of cylinders. CONSTITUTION:In a knocking sensing circuit 23 for sensing knocking of an engine 1 in association with a controller 22, a single knocking sensor 20 is used for sensing vibration caused in respective cylinders. The value of the vibration sensed is compared with comparison levels for discriminating knocking which are set for the respective cylinders for sensing knocking. The condition of knocking caused in a prescribe period of time is examined and the data of the condition is averaged for determining the level of the knocking in the period. An ignition timing for each cylinder is controlled based on the result of it for controlling the knocking, wherein knocking discriminating cycles for the respective cylinders are changed depending upon the cylinders, the discriminating cycle being made longer for a cylinder to which the sensitivity of the knock sensor is bad. |
