| 摘要 |
PURPOSE:To always align an exhaust gas recirculation (EGR) rate to a target value, by measuring intake air and EGR amounts at each fixed running distance, checking the EGR rate and correcting a control command value on the basis of a difference between standard and inspected values. CONSTITUTION:An intake air amount signal, measured by an intake air amount sensor 40 provided in the upstream of a throttle valve 23 in an intake passage 21, and an exhaust gas recirculation (EGR) amount signal, from a pressure difference transducer 3 measuring an EGR amount, are input to a control circuit 28. Further a distance sensor 41, detecting a running distance of a vehicle and transmitting a signal to the control circuit 28 at each fixed running distance, is provided, and the control circuit 28 selects a control target value of EGR from a table pick up in accordance with an operation condition, to control an EGR valve 25 or the throttle valve 23 with said target value as a command. Simultaneously, at each prescribed running distance, an error of the EGR rate for the control target value is detected to correct the control command value. |
