| 摘要 |
An ECU calculates a foreign-matter accumulation index base on a total flow rate of EGR gas integrated since the previous execution of a last foreign-matter removal operation until the present execution of the foreign-matter removal operation. The ECU controls an actuator for operating an EGR valve and a number of the actuations of the EGR valve on the basis of the foreign-matter accumulation index. When the total flow rate of the EGR gas increases, the quantity of foreign matters contained in EGR gas correspondingly increases. Therefore, as the foreign-matter accumulation index becomes larger, the actuation intensity of the EGR valve is set higher and the number of the actuations of the EGR valve is set larger. As a result, the removal operation of foreign matters can be efficiently executed in accordance with the deposition intensity or the deposition quantity of foreign matters.
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