Electromechanical valve actuator for internal combustion engines and internal combustion engine equipped with such an actuator
AssigneePeugeot Citroen Automobiles SA
InventorsEmmanuel Sedda, Christophe Fageon, Stephane Guerin, Jean-Paul Yonnet
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Abstract
An electromechanical valve actuator for internal combustion engines, equipped with a polarized electromagnet and with a magnetic plate switches between a first position close to the electromagnet and a second position remote from the electromagnet, the switching times between these positions being determined depending on the operating state of the engine. The actuator supplies the electromagnet with a variable attracting current in the course of the approach of the plate to the electromagnet.
Claims9
A method of displacing a mobile magnetic plate of an electromechanical valve actuator for internal combustion engines from a second position to a first position, said electromechanical valve actuator comprising:
- a first polarized electromagnet and a second polarized electromagnet, each polarized electromagnet including a magnet,
- a mobile magnetic plate positioned between the electromagnets and configured for switching between a first position close to the first electromagnet and a second position close to the second electromagnet,
- the switching times between these first position and the second positions being determined depending on the operating state of the engine,
- said method of displacing the mobile magnetic plate from the second position to the first position comprising the steps of:
- supplying the first electromagnet with a variable attracting current, wherein the variable attracting current increases progressively to a peak value in the course of the approach of the plate to the first electromagnet, and the variable attracting current is immediately decreased after the peak value is achieved, and is decreasing when the magnetic plate contacts the first electromagnet, and
- supplying the second electromagnet with a second current generating a magnetic field opposite to the magnetic field of the magnet of the second electromagnet in order to temporarily demagnetize the magnet of the second electromagnet, the second current being of an intensity lower than or equal to the intensity of the magnetic field generated by the magnet of the second electromagnet, wherein the second current is generated at least until the mobile magnetic plate has traveled about one-half of the distance separating the first electromagnet from the second electromagnet.
Dependencies are inferred from the claim text.