The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 04, 2003
Filed:
Aug. 06, 2001
Makoto Itoi, Toyko, JP;
Tsuneo Tanabe, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An EGR valve control apparatus is provided which is capable of controlling an amount of exhaust gas to be recirculated in a precise and proper manner by using a step motor, as well as improving the durability of an EGR valve. The EGR valve control apparatus adjusts an opening of the EGR valve for opening and closing an exhaust gas recirculation passage connecting between an exhaust passage and an intake passage by means of the step motor. The apparatus includes a hysteresis-provided drive control section for driving the 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 the step motor when a difference between the target position and the current position of the 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 the 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 the step motor remains for a predetermined period of time.