| 摘要 |
<p>PURPOSE: To perform correction of displacement in a position due to the loss of synchronism of a step motor by a method wherein when the target opening of an EGR valve is brought into a full closed state during control of EGR, initialization is performed in such a manner that closing is effected until the valve body of the EGR valve is collided with a valve seat with the aid of the step motor of an initialization control means. CONSTITUTION: In an engine wherein an EGR cooler 46 and an EGR valve 15 are located in an EGR passage 45 through which the part situated upper stream of the O2 sensor 44 of an exhaust manifold 35 and a surge tank 25 situated downstream from a throttle valve 24, when the target opening of an EGRV 15 is brought into a full opening during control of EGR, by effecting closing until the valve body 57 of the EGR valve 15 is collided with a valve seat with the aid of a step motor 15a, the step motor 15a is initialized. Execution of the initialization is such that the step motor 15a is driven preferably at the number of steps higher than the actual number of steps. This constitution corrects displacement in a position owing to the loss of synchronism of the step motor 15a.</p> |
