Patent Document ID: 20040163623
Application ID: 10776306
Patent Flag: 0

Claim One:
1. An ignition timing control apparatus for an internal combustion engine having a plurality of cylinders, operation of said engine being switchable between partial-cylinder operation, which operates some of the cylinders, and all-cylinder operation, which operates all of the cylinders, said ignition timing control apparatus comprising: basic ignition timing calculating means for calculating a basic ignition timing according to an operating condition of said engine; a knock sensor mounted on said engine; knocking determining means for determining whether knocking has occurred based on an output of said knock sensor; correcting means for calculating a correction amount according to a determined result from said knocking determining means to suppress knocking, and correcting the basic ignition timing using the calculated correction amount; and learning value calculating means for calculating learning values of the correction amount calculated by said correcting means, wherein said learning value calculating means calculates the learning values corresponding, respectively, to the partial-cylinder operation and the all-cylinder operation, and wherein said correcting means uses one of the learning values calculated by said learning value calculating means, according to the operating condition of said engine.