Method for controlling ignition timing of an internal combustion engine

Claim 1

A method for controlling ignition timing of an internal combustion engine having an ignition timing control system for calculating an ignition timing based on a basic ignition timing, a learning correcting quantity including a large correcting quantity and a small correcting quantity, and a feedback correcting quantity, the method comprising the steps of: detecting an occurrence of knocking; producing a knock signal responsive to said occurrence of knocking; converging the feedback correcting quantity to a large retard value in response to the knock signal; comparing the large retard value with a predetermined reference value; generating a change signal when the large retard value exceeds the reference value; and changing the learning correcting quantity of the small correcting quantity to the learning correcting quantity of the large correcting quantity in response to the change signal.

Claim 2

A method for controlling ignition timing of an internal combustion engine having an ignition timing control system for calculating an ignition timing based on a basic ignition timing, a learning correcting quantity including a large correcting quantity and a small correcting quantity, and a feedback correcting quantity, the method comprising the steps of: detecting an occurrence of knocking; producing a knock signal responsive to said occurrence of knocking; converging the feedback correcting quantity to a large retard value in response to the knock signal; comparing the large retard value with a predetermined reference value; generating a change signal when the large retard value exceeds the reference value; and changing the learning correcting quantity of the small correcting quantity to the learning correcting quantity of the large correcting quantity in response to the change signal.

Claim 4

A system for controlling ignition timing of an internal combustion engine having an ignition timing control system for calculating an ignition timing based on a basic ignition timing, a learning correcting quantity including a large correcting quantity and a small correcting quantity, and a feedback correcting quantity, the system comprising: detector means for detecting an occurrence of knocking and for producing a knock signal; changing means responsive to the knock signal for changing the feedback correcting quantity to a large retard value; comparing means for comparing the large retard value with a predetermined reference value and for producing a change signal when the large retard value exceeds the reference value; and means responsive to the change signal for changing the learning correcting quantity of the small correcting quantity to the learning correcting quantity of the large correcting quantity.

Claim 5

A system for controlling ignition timing of an internal combustion engine having an ignition timing control system for calculating an ignition timing based on a basic ignition timing, a learning correcting quantity including a large correcting quantity and a small correcting quantity, and a feedback correcting quantity, the system comprising: detector means for detecting an occurrence of knocking and for producing a knock signal; changing means responsive to the knock signal for changing the feedback correcting quantity to a large retard value; comparing means for comparing the large retard value with a predetermined reference value and for producing a change signal when the large retard value exceeds the reference value; and means responsive to the change signal for changing the learning correcting quantity of the small correcting quantity to the learning correcting quantity of the large correcting quantity.