Patent attributes
An internal-combustion-engine combustion condition detection apparatus that can accurately comprehend a combustion condition is obtained. The internal-combustion-engine combustion condition detection apparatus includes an ion-current detection device (41) that detects an ion current generated during combustion and ignition devices including a first ignition device (21) having a first ignition plug (11) that causes main combustion in a combustion chamber (33) and a second ignition device (22) having a second ignition plug (12) disposed in the same combustion chamber (33) as and spaced apart from the first ignition plug (11) of the first ignition device (21); the ion-current detection device (41) detects a combustion ion current that is generated in the second ignition device (22) regardless of whether or not ignition is performed by the second ignition device (22), thereby detecting pre-ignition or a precursor phenomenon of pre-ignition.
