Patent Number: 6,167,873

Title: Apparatus for controlling EGR valve of diesel engine and method

Abstract: A disclosed apparatus and method controls an EGR valve including a valve body, a valve seat, and a step motor that fully closes the EGR passage by moving the valve body to abut onto the valve seat and that opens the EGR passage by moving the valve body away from the valve seat. This valve body is located on a side of the exhaust passage as viewed from the valve seat. A determination is made of whether the voltage of a battery connected to the step motor is relatively low, whether the temperature of a cooling water of the diesel engine is relatively high, and whether the exhaust gas pressure of the diesel engine is at a relatively high level. When it is determined that the voltage of the battery is relatively low, and/or it is determined that the temperature of the cooling water of the diesel engine is relatively high, and it is determined that the exhaust gas pressure of the diesel engine is at the relatively high level, the EGR valve is forcedly fully closed.

Inventors: Kataoka; Hideki (Kanagawa-ken, JP)

Assignee: Nissan Motor Co., Ltd.

International Classification: F02D 21/08 (20060101); F02D 41/20 (20060101); F02D 21/00 (20060101); F02M 025/07 (); H02P 008/00 ()

Expiration Date: 01/02/2018