Patent ID: 6338323
Filing Date: 2002-01-15
Classification: F01L

Abstract:
A vane type variable valve timing control apparatus comprising:a vane secured to a cam shaft; a housing provided integral with a cam sprocket, and housing said vane so as to be relatively rotatable thereto to thereby form an advance angle side hydraulic chamber and a delay angle side hydraulic chamber on rotation direction front and rear sides of said vane, a spool valve for stopping supply and discharge of oil with respect to said both hydraulic chambers in a neutral position, and switching hydraulic chambers for which oil supply and discharge is being performed depending on a movement direction from said neutral position, so that when oil is being supplied to one hydraulic chamber oil is discharged from the other hydraulic chamber; a resilient body for urging said vane to either one of an advance angle side and a delay angle side; target value calculation means for calculating a target value of a rotation phase of said cam shaft to said cam sprocket; neutral control value calculation means for calculating a neutral control value of said spool valve corresponding to said target value; rotation phase detection means for detecting a rotation phase of said cam shaft to said cam sprocket; feedback correction value calculation means for calculating a feedback correction value based on the rotation phase detected by said rotation phase detection means and said target value; and valve control means for controlling said spool valve based on said neutral control value and said feedback correction value.