Patent ID: 6505585
Filing Date: 2003-01-14
Classification: F01L

Abstract:
An apparatus for controlling valve timing of an engine comprising:a housing connected to a cam sprocket, with recess portions therein; a rotation member connected to an end portion of a cam shaft and incorporating vanes integrally disposed in said recess portions, and partitioning each of said recess portions by each of said vanes to thereby form advance angle side hydraulic chambers and delay angle side hydraulic chambers at both sides of said respective vanes; a control valve for relatively controlling the supply and discharge of oil pressure to said advance angle side hydraulic chambers and delay angle side hydraulic chambers; a rotation phase measuring device for measuring a rotation phase of said cam shaft with respect to a crank shaft; a feedback control device for feedback controlling a control signal for said control valve so that a rotation phase measured by said rotation phase measuring device coincides with a target value; and an offset device which computes an offset to be added to said control signal when a feedback control by said feedback control device is converged, and when said control signal becomes within a predetermined range, forcibly drives a valve timing apparatus based on said control signal added with said offset.