Knock control apparatus for internal combustion engine

A knock control apparatus for an internal combustion engine comprising:

• a knock detection section that evaluates an ionic current generated upon combustion of a mixture around a spark plug of the internal combustion engine and outputs a knock detection signal;
• a threshold setting section that sets a knock determination threshold for said knock detection signal;
• a knock determination section that determines the presence or absence of a knock based on said threshold and said knock detection signal;
• a required correction amount setting section that sets an amount of correction for a control parameter including at least ignition timing based on a determination result of said knock determination section;
• a control parameter correction section that sets a control parameter correction amount based on said required correction amount and corrects said control parameter;
• a noise determination section that determines the presence or absence of noise based on whether at least one of said knock detection signal and said control parameter correction amount is within a set level range;
• and
• a noise removal period setting section that sets a noise removal period based on a determination result of said noise determination section;
• wherein said noise removal period setting section starts a noise removal period timer when it is determined that at least one of said knock detection signal and said control parameter correction amount is within said set level range;
• and
• said noise removal period setting section inhibits correction processing of said control parameter correction section for a period of time in which a timer value of said noise removal period timer is less than a predetermined value, and permits said correction processing when said timer value reaches said predetermined value.