Patent ID: 8857392

Claim:
A motor vehicle camshaft adjusting device comprising an open- and a closed-loop control unit ( 11 ) provided for adjusting a phase position of a camshaft ( 12 ) and for adjusting the camshaft phase position in a normal operating mode with a predetermined valve opening angle range (β) corresponding to the geometry of the respective cam, the camshaft adjusting device including a frictional coupling element for controlling the camshaft advance or retardation by the control unit ( 11 ), the control unit ( 11 ) having an engine start operating mode which is provided for setting a valve opening angle range (α), which is smaller than the geometric normal valve opening angle range (β) as a result of a camshaft retarding and advancing movement during the valve opening period, by permitting in the engine start-up mode a retardation of the camshaft and the cam during a valve opening period by the force required for lifting the valve against the force of the valve spring of the cam and an advance of the camshaft during a valve closing period by the force of the valve spring on the cam.