Patent ID: 8762033

Claim:
An internal combustion engine control device comprising: guard means for guarding the ignition timing by the retardation limit of a ignition timing range where the combustion in an internal combustion engine is maintainable; judgment means for judging whether fuel cut permission conditions are satisfied; relief means for relieving the ignition timing guard provided by the guard means when the fuel cut permission conditions are satisfied; torque control means for reducing the output torque of the internal combustion engine by retarding the ignition timing after the fuel cut permission conditions are satisfied; and fuel supply shutoff means for shutting off the supply of fuel after the output torque of the internal combustion engine is reduced to a predefined minimum torque, wherein the torque control means includes: target torque setup means, which serves as means for setting a target torque for the internal combustion engine and, after the fuel cut permission conditions are satisfied, reduces the target torque to the minimum torque; intake air amount control means for controlling the operation amount of an intake actuator, which adjusts the intake air amount of the internal combustion engine, in accordance with the target torque; estimated torque calculation means for calculating an estimated torque that is obtained when the ignition timing is adjusted for MBT without changing the current operation amount of the intake actuator; torque efficiency calculation means for calculating torque efficiency from the ratio between the target torque and the estimated torque; ignition retardation amount setup means for setting a retardation amount for the ignition timing in accordance with the torque efficiency; and ignition timing control means for controlling the ignition timing in accordance with the retardation amount; and wherein the target torque setup means includes: requested output torque acquisition means for acquiring an output torque that a consumption element, which consumes the torque of the internal combustion engine, requests the internal combustion engine to generate; pre-fuel-cut torque request means, which serves as request means for expressing a request concerning a pre-fuel-cut operating state in terms of a torque value, requests a value beyond an achievable torque range as a pre-fuel-cut torque when the fuel cut permission conditions are not satisfied, and gradually reduces the pre-fuel-cut torque from an output torque requested when the fuel cut permission conditions are satisfied to the minimum torque after the fuel cut permission conditions are satisfied; and mediation means for comparing the requested output torque and the pre-fuel-cut torque and selecting the lower of the two torques as a target torque.