Patent ID: 8793058
Filing Date: 2014-07-29
Classification: F02D,F02P,Y02T

Abstract:
1. A control device for an internal combustion engine, comprising: required torque determining means which determines a required value of torque (hereinafter, required torque) generated by the internal combustion engine; required air-fuel ratio determining means which determines a required value of an air-fuel ratio (hereinafter, a required air-fuel ratio) of an air-fuel mixture provided for combustion; target air amount calculating means which calculates a target air amount for realizing the required torque under the required air-fuel ratio, based on data with a relationship between the torque generated by the internal combustion engine and an air amount taken into a cylinder being set by being linked with the air-fuel ratio; air amount control means which operates an actuator for air amount control in accordance with the target air amount; and fuel injection amount control means which operates an actuator for fuel injection amount control in accordance with the required air-fuel ratio, wherein the required air-fuel ratio determining means comprises required air-fuel ratio calculating means which receives a requirement relating to exhaust gas performance of the internal combustion engine, and calculates an air-fuel ratio which satisfies the requirement as a required air-fuel ratio, change speed reducing means which processes a signal of the required air-fuel ratio calculated in the required air-fuel ratio calculating means to reduce a change speed of the required air-fuel ratio, and final determining means which determines a required air-fuel ratio with the change speed reduced by the change speed reducing means as a final required air-fuel ratio when a predetermined reduction condition is satisfied, and determines the required air-fuel ratio which is calculated in the required air-fuel ratio calculating means as a final required air-fuel ratio when the reduction condition is not satisfied, the reduction condition includes a condition that the change amount of a calculated value of the required air-fuel ratio calculating means is larger than a predetermined air-fuel ratio change determination value; target air amount increasing means which increases the target air amount to compensate for a decrease of torque accompanying retardation of an ignition timing when there is a requirement for retarding the ignition timing from an optimal ignition timing; and ignition timing control means which operates an actuator for ignition timing control so that torque which is realized under the required air-fuel ratio corresponds to the required torque when the actuator for air amount control is operated in accordance with the increased target air amount; and wherein the reduction condition further includes a condition that a retardation amount of the ignition timing with respect to the optimal ignition timing is smaller than a predetermined threshold value.