Patent ID: 6298823
Filing Date: 2001-10-09
Classification: F02P,Y02T

Abstract:
A knock control apparatus for an internal combustion engine, comprising:an ignition coil for generating a high ignition voltage in conformance with ignition timing of said internal combustion engine;a spark plug for generating spark discharge in an engine cylinder of said internal combustion engine upon application of said high ignition voltage;ion current detecting means for detecting an ion current flowing by way of said spark plug upon combustion of air-fuel mixture within said engine cylinder;filter means for extracting a knock signal from an output signal of said ion current detecting means;knock decision means for deciding occurrence of a knock event in said engine on the basis of said knock signal;control quantity correcting means for correcting a control quantity for said internal combustion engine so as to suppress the knock event on the basis of result of decision made by said knock decision means; andsooting state detecting means for detecting a sooting state of said spark plug on the basis of a current signal detected through said ion current detecting means during a period in which said ion current is not detected,wherein said sooting state detecting means generates a correction inhibiting signal for inhibiting correction of said control quantity as performed by said control quantity correcting means on the basis of said decision result of said knock decision means when the sooting state of said spark plug is detected.