Patent ID: 8209105

Claim:
An internal combustion engine apparatus including an internal combustion engine comprising: a plurality of cylinder groups each consisting of at least one cylinder; an exhaust passage having branch portions provided for the respective cylinder groups and a common portion extending toward the downstream side from where the branch portions converge; a recoverable exhaust gas purification device provided in the common portion; a fuel supply system that supplies fuel to the respective cylinder groups; a controller that executes, through the control of the fuel supply system, a bank control in which an air-fuel ratio of a first cylinder group among the cylinder groups is made richer than a stoichiometric air-fuel ratio and an air-fuel ratio of a second cylinder group among the cylinder groups is made leaner than the stoichiometric air-fuel ratio so as to recover the exhaust gas purification device, wherein the internal combustion engine runs on fuel containing alcohol and includes an alcohol concentration obtaining portion that obtains the concentration of alcohol in fuel supplied from the fuel supply system, the controller adjusts, through the control of the fuel supply system, the amount of unburned fuel to be supplied to the exhaust gas purification device during the bank control based on the alcohol concentration obtained by the alcohol concentration obtaining portion, and the controller corrects an amount of fuel to be supplied to the first cylinder group during the bank control based on the alcohol concentration obtained by the alcohol concentration obtaining portion.