| 摘要 |
PURPOSE:To prevent generation of shock and so forth due to operation delay by making the smaller value of a basic aimed value based on the driving state or a limit value corresponding to the maximum opening degree of an EGR value which can be corrected according to the atmospheric pressure as an aimed value of EGR valve feedback control. CONSTITUTION:When volume of charging negative pressure introduced into an actuator 6 which drives an EGR valve 5 is controlled by a control valve 9, a feedback controlling means 10 for controlling the control valve 9 so that the aimed opening degree from an aimed value setting means 11 and a real opening degree from a position sensor 12 accord with each other. The aimed value setting means 11 is constituted so that the smaller value of the basic aimed value from a basic aimed value operating means 13 or the maximum opening degree amount from a limit value setting means 14 is set as the final aimed value. The limit value setting means 14 is constituted so that the limit value corresponding to the maximum opening degree of the EGR valve 5 is set based on the intake air negative pressure, and the limit value can be corrected by a correcting means 18 so that it is corrected to a small value according to drop of the atmospheric pressure.
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