Patent ID: 6640791
Filing Date: 2003-11-04
Classification: F02D,F02M,Y02T

Abstract:
An EGR valve control apparatus in which an opening of an EGR valve for opening and closing an exhaust gas recirculation passage connecting between an exhaust passage and an intake passage is adjusted discretely in a plurality of steps, said EGR valve control apparatus comprising:a detecting section for detecting operating conditions of an internal combustion engine; a step motor target position calculating section for calculating a target position of a step motor in accordance with the operating conditions of said internal combustion engine detected by said detecting section; a difference calculating section for calculating a difference between a current position and the target position of said step motor; a hysteresis-provided drive control section for driving said step motor in accordance with the target position and performing control with hysteresis of two steps or more so as to hold the position of said step motor when a difference between the target position and the current position of said step motor is equal to or less than a prescribed n steps which is equal to or greater than two steps; and a forced drive control section for driving said step motor to the target position thereof while stopping the hysteresis-provided control when a deviation between the target position and the current position of said step motor remains for a predetermined period of time.