Patent ID: 6390037
Filing Date: 2002-05-21
Classification: F01L,F02D

Abstract:
Method for regulation of currents during phases of stoppage in electromagnetic actuators, for actuation of intake and exhaust valves in internal-combustion engines, in which an actuator (1) is connected to a respective intake or exhaust valve (2) which has a position (Z), and includes a mobile unit (3), which is actuated magnetically in order to control the movement of the said valve (2), a sensor (12) which supplies a position signal (VZ) which is representative of a present position (Z) of the said mobile unit (3), and a first and a second electromagnet (6a,6b), which are disposed on opposite sides of the said mobile unit (3), and receive respectively a first and a second current (ISUP, IINF); the said mobile unit (3) being disposed in a position of stoppage (ZSUP, ZINF) during phases of stoppage; the said position of stoppage (ZSUP, ZINF) corresponding alternately to a first position of end of travel (ZSUP), in which the said mobile unit (3) abuts the said first electromagnet (6a), and to a second position of end of travel (ZINF), in which the said mobile unit (3) is disposed such as to abut the said second electromagnet (6b); the method being characterised in that it comprises the phases of:a) setting (100) at least one current (ISUP, IINF) out of the said first and the second currents (ISUP, IINF) to an initial maintenance value (IHO), when the said valve (2) is in the said position of stoppage (ZSUP, ZINF); b) checking (120) that the said valve remains in the said position of stoppage (ZSUP, ZINF) for a pre-determined interval of time (&Dgr;T); and c) decrementing (170) the said at least one current (ISUP, IINF), if the said valve has remained in the said position of stoppage (ZSUP, ZINF) for the said pre-determined interval of time (&Dgr;T).