Patent ID: 8316824
Filing Date: 2012-11-27
Classification: F02D,F02P,Y02T

Abstract:
1. A control apparatus for an internal combustion engine, comprising: operating state detection means for detecting an operating state of the internal combustion engine; variable valve mechanism control means for changing an operation state of a variable valve mechanism in accordance with the operating state to vary an effective compression ratio to obtain a desired effective compression ratio; ignition timing control means for controlling ignition timing in accordance with the operating state; first knock detection means for detecting occurrence of a first knock based on a detection signal by a knock sensor provided to a cylinder block; first knock suppression means for suppressing the first knock by retarding the ignition timing being set in accordance with the operating state when the first knock is detected by the first knock detection means; second knock detection means for judging that a second knock due to the effective compression ratio has occurred when the ignition timing in a case where the first knock is detected by the first knock detection means is on a retard side of a predetermined value; second knock suppression means for suppressing the second knock by calculating a first amount of reduction in the effective compression ratio to change the operation state of the variable valve mechanism so as to reduce the effective compression ratio based on a knock intensity of the second knock when it is judged by the second knock detection means that the second knock has occurred, and by giving the calculated first amount of reduction in the effective compression ratio to the variable valve mechanism control means as a control instruction; first abnormal ignition detection means for judging that first abnormal ignition has occurred due to any one of pre-ignition and post-ignition when the knock intensity of the second knock is equal to or larger than a predetermined value; and first abnormal ignition suppression means for suppressing the first abnormal ignition by performing fuel control for the internal combustion engine when it is judged by the first abnormal ignition detection means that the first abnormal ignition has occurred.