Ignition timing control for internal combustion engines

Claim 3

A method as defined in claim 1, wherein said correction amount determining step further includes a step of utilizing the relationship between a calculated knock rate and predetermined values to select the correction amount.

Claim 4

A method as defined in claim 1 or 2, wherein said correction amount determining step further includes a step of deciding whether a current amount of correction of ignition timing has a sign opposite of the sign of the preceding amount of correction of ignition timing to determine whether a sign change has occurred.

Claim 5

A method as defined in claim 3, wherein said correction amount determining step further includes a step of reducing correction factor constants which are used in the calculation of the amount of correction of ignition timing, if a sign change has occurred.

Claim 6

A method as defined in claim 4, wherein said correction amount determining step further comprises a step of restoring the reduced amount of correction calculation constants to a predetermined amount of correction of the ignition timing if said running condition changes.

Claim 7

A method as defined in claim 1, wherein said correction amount obtaining step includes a step of the decision of knock and a subsequent step of the generation of knock pulses, the generated knock pulses being used in a step of the generation of advance ignition timing pulses and a step of up/down counting for the correction of the ignition timing.

Claim 8

A method as defined in claim 6, wherein said correction amount obtaining step includes a step of the generation of signals for up/down switching, and a subsequent step of up/down counting for the amount of correction of the ignition timing, the determined amount of correction of the ignition timing being used in said step of up/down counting for correction of the ignition timing.

Claim 9

A method as defined in claim 6, wherein pulses generated by said step of the generation of advance ignition timing pulses are used in said step of up/down counting for the correction of the ignition timing.

Claim 10

A method as defined in claim 1, wherein said correction amount determining step includes the steps of: deciding whether a current amount of correction of ignition timing has a sign opposite of the sign of a preceding amount of correction of ignition timing to determine occurrence of a change of direction of correction between the preceding ignition and the current ignition, and reducing correction factor constants used in the calculation of the amount of correction of ignition timing whenever a correction sign change has occurred.

Claim 13

Apparatus for controlling ignition timing of an internal combustion engine, comprising: means for supplying signals representing engine running conditions; knock detection means for detecting knock in said engine and supplying a signal representative thereof; ignition means, responsive to signals, for providing ignition to said engine; and computer means for receiving the signals from said signal supplying means and said knock detection means, for calculating the ignition timing of the engine based on said received signals, and for delivering correction factor signals to said ignition means, said computer means furthermore deciding whether a current correction signal has a sign opposite of a sign of a preceding correction signal, and carrying out a reduction of the correction signal according to the result of said decision.

Claim 14

Apparatus for controlling ignition timing of an internal combustion engine, comprising: means for supplying signals representing engine running conditions; knock detection means for detecting knock in said engine and supplying a signal representative thereof; ignition means, responsive to signals, for providing ignition to said engine; and computer means for receiving the signals from said signal supplying means and said knock detection means, for calculating the ignition timing of the engine based on said received signals, and for delivering correction factor signals to said ignition means, said computer means furthermore deciding whether a current correction signal has a sign opposite of a sign of a preceding correction signal, and carrying out a reduction of the correction signal according to the result of said decision.

Claim 15

Apparatus for controlling ignition timing of an internal combustion engine, comprising; means for supplying signals representing engine running conditions; knock detection means for detecting knock in said engine and supplying a signal representative thereof; ignition means, responsive to signals, for providing ignition to said engine; and computer means for receiving the signals from said signal supplying means and said knock detection means, for calculating the ignition timing of the engine based on said received signals, and for delivering correction factor signals to said ignition means, said computer means establishing a basic ignition timing in accordance with the engine running conditions, and calculating correction signals based on the signals from said knock detection means, said computer means further calculating a knock rate based on the signals from said knock detection means and a reference level, calculating the correction signals utilizing said calculated knock rate and a predetermined coefficient, deciding whether a current correction signal has a sign opposite of a sign of a preceding correction signal which is stored in a memory in said computer means, and reducing said predetermined coefficient when the result of said decision is affirmative.

Claim 16

Apparatus for controlling ignition timing of an internal combustion engine, comprising; means for supplying signals representing engine running conditions; knock detection means for detecting knock in said engine and supplying a signal representative thereof; ignition means, responsive to signals, for providing ignition to said engine; and computer means for receiving the signals from said signal supplying means and said knock detection means, for calculating the ignition timing of the engine based on said received signals, and for delivering correction factor signals to said ignition means, said computer means establishing a basic ignition timing in accordance with the engine running conditions, and calculating correction signals based on the signals from said knock detection means, said computer means further calculating a knock rate based on the signals from said knock detection means and a reference level, calculating the correction signals utilizing said calculated knock rate and a predetermined coefficient, deciding whether a current correction signal has a sign opposite of a sign of a preceding correction signal which is stored in a memory in said computer means, and reducing said predetermined coefficient when the result of said decision is affirmative.