Ignition timing control apparatus for internal combustion engine

An ignition timing control method 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 method comprising the steps of:

• a) calculating a basic ignition timing according to an operating condition of said engine;
• b) determining whether knocking has occurred based on an output of a knock sensor mounted on said engine;
• c) calculating a correction amount according to a determined result in said step b) to suppress knocking;
• d) correcting the basic ignition timing with the calculated correction amount;
• and
• e) calculating learning values of the calculated correction amount,
• wherein the learning values are calculated corresponding, respectively, to the partial-cylinder operation and the all-cylinder operation, and one of the calculated learning values is used for the correction in said step d) according to the operating condition of said engine.

A computer program for causing a computer to carry out an ignition timing control method 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 method comprising the steps of:

• a) calculating a basic ignition timing according to an operating condition of said engine;
• b) determining whether knocking has occurred based on an output of a knock sensor mounted on said engine;
• c) calculating a correction amount according to a determined result in said step b) to suppress knocking;
• d) correcting the basic ignition timing with the calculated correction amount;
• and
• e) calculating learning values of the calculated correction amount,
• wherein the learning values are calculated corresponding, respectively, to the partial-cylinder operation and the all-cylinder operation, and one of the calculated learning values is used for the correction in said step d) according to the operating condition of said engine.