Method for controlling an electromagnetic valve drive by changing the current direction when supplying the electromagnets with current

Abstract

A method for controlling an electromagnetic actuator for actuating a cylinder valve (6) in a piston-type internal-combustion engine, with the valve having two electromagnets (1, 2) that are spaced from one another, and an armature (5) that is connected to the cylinder valve (6) to be actuated and is guided back and forth, counter to the force of a restoring spring (7, 8), between the facing magnet pole faces of the electromagnets, and with the coils (10, 11) of the electromagnets alternately being acted upon with a direct current via a control device (9) at predetermined intervals. When the piston-type internal-combustion engine is operated under a higher load, the flow direction of the current through the coils (10, 11) of the two electromagnets (1, 2) is preset by the control device (9) so that the magnetic flux (arrows 14, 15) alternately effected in the armature (5) by the two coils (10, 11) remains unidirectional. For low-load operation (idling mode) of the engine, the magnetic flux is altered by the repolarization of the flow direction of the current through one of the coils (10, 11), so that the magnetic flux effected in the armature (5) alternately flows in opposite directions (arrows 14.1, 15.1) when the coils are supplied with current.

Dependencies are inferred from the claim text.