Patent ID: 6333843
Filing Date: 2001-12-25
Classification: F01L

Abstract:
A method of starting an electromagnetic actuator for operating a cylinder valve of a piston-type internal-combustion engine, the actuator havingtwo spaced electromagnets having respective pole faces oriented toward one another; one of the electromagnets being a valve-closing electromagnet and the other of the electromagnets being a valve-opening electromagnet;a restoring spring;an armature connected to the cylinder valve and being arranged for reciprocation between the electromagnets against the force of the restoring spring; andan ECU alternatingly supplying the electromagnets with a capturing current, the level of which being regulated as a function of the distance of the armature toward at least one pole face, the method comprising the following steps:(a) detecting a temperature at least at one of the electromagnets;(b) in case the temperature determined in step (a) is within a predetermined normal temperature range,(1) beginning to oscillate the armature by alternatingly supplying current to the electromagnets at a resonant frequency of an oscillating system comprising the armature, the cylinder valve and the restoring spring; and(2) bringing the armature into contact with one of the pole faces; and(c) in case the temperature determined in step (a) is below the predetermined normal temperature range, supplying one of the electromagnets with a high current pulse.