Patent ID: 7712450

Claim:
An ignition timing control apparatus for an internal combustion engine, comprising: a learning portion that sets a learning value of an ignition timing when the internal combustion engine is in a given operating state, by executing a learning control, wherein the learning value is used in an ignition timing control executed when the internal combustion engine is in another operating state; an estimated knocking occurrence ignition timing setting portion that sets an estimated knocking occurrence ignition timing based on a most retarded ignition timing using the learning value, wherein the most retarded ignition timing is set based on an operating state of the internal combustion engine; and a final ignition timing setting portion that sets a final ignition timing, by executing a feedback correction process in which a correction amount is based on whether knocking occurs when ignition is performed at the estimated knocking occurrence ignition timing, wherein when a point indicating the operating state of the internal combustion engine moves into a region where it is difficult to set the estimated knocking occurrence ignition timing, the final ignition timing setting portion changes the correction amount by a predetermined amount, to a changed correction amount, so as to retard the final ignition timing, and sets the final ignition timing using the learning value and the changed correction amount, and wherein the region where it is difficult to set the estimated knocking occurrence ignition timing is a low load region in which an engine load is low.