| 摘要 |
PURPOSE:To enable control of an ignition timing to an optimum ignition timing under all operating conditions, by a method wherein feedback control is made by correcting a reference ignition timing in both directions of a lead angle and an angle of delay by means of a correcting value changing in a manner to stretch over positive and negative, based on knock detecting information. CONSTITUTION:An ignition timing control device 20 consisting of a microcomputer stores a control value, providing a reference ignition timing characteristic, in each address of a memory 22, and reads out the corresponding map data by means of a crank angle, a pressure, and an acceleration angle signal from sensors 11, 12, and 14. An ignition timing is controlled in a way to correct the stored data by means of a correcting value, changing in a manner to stretch over positive and negative, through computation of the output of a knock detector 15 for detecting a knock component included in the acceleration sensor 14. Thus, a reference ignition timing characteristic is set centering around the optimum value of a knock limit, and as knock of a control starting point is controlled, and besides, even in an operation range in which the reference ignition timing is set to an ignition timing being behind the knock limit, the optimum ignition timing at the knock limit can be controlled, and an ignition timing can be controlled to the optimum ignition timing under all operating conditions. |
