Valve timing system for an internal combustion engine

Method of making a valve timing gear for an internal-combustion engine, comprising the acts of:

• providing a timing cam on a camshaft which acts by a tilting segment in a tappet in a timing manner upon a lifting valve, said tilting segment being constructed with a contact path acted upon by the timing cam and arranged in a movably guided manner by a circular-arc section concentric to the axis of rotation of the camshaft in the tappet,
• providing a control device whereby during each valve lift, an engagement of the contact path with flanks of the rotating timing cam, which engagement determines opening and closing phases of the lifting valve, is achieved by a swivelling movement of the tilting segment which is forcibly controlled in the same and/or opposite direction relative to the rotating direction of the timing cam,
• wherein the control device comprises a slider rocker which can be adjusted in the valve lifting direction with the control opening eccentrically to the axis of rotation of the camshaft, such that while the camshaft is rotating, it carries out for each valve lift a periodic rocking movement which forcibly controls the tilting segment and which takes place transversely to the valve lifting direction with a superimposition with a sliding movement caused in the valve lifting direction.

A control device for a timing gear of an internal combustion engine comprising,

• a slider rocker being guidable in a valve lifting direction by a first sliding hinge joint on a first side and by a second sliding hinge joint on a second side, said slider rocker including a control opening having clearance for a camshaft, and
• an adjusting device being arranged in and on the camshaft and rotating with the camshaft, said adjusting device including an element contacting the circumference of the control opening, wherein the slider rocker is adjusted in the valve lifting direction via the control opening being contacted eccentrically to the axis of rotation of the camshaft, and the slider rocker for each valve lift carries out a periodic rocking movement transverse to the valve lifting direction to forcibly control a contact path of a timing cam upon a lifting valve control.