ELECTROMAGNETIC ACTUATOR FOR A PROPORTIONAL SOLENOID VALVE

摘要

An electromagnetic actuator (4) for a proportional solenoid valve (1), which actuator (4) has a fixed ferromagnetic core (5) having a longitudinal axis (6), a plunger (7) movable with respect to the fixed core (5) along the axis (6) between two stroke end positions (x1, x2), a spring (9) for moving the plunger (7) to the first stroke end position (x1), an energizing winding (10) to generate an electromagnetic induction field which produces a force against the bias of the spring (9) and such that it moves the plunger (7) to a equilibrium position (xeq) between the stroke end positions (x1, x2), and wherein a surface portion (26, 28) of the plunger (7) is increasingly facing a surface portion (15, 16) of the fixed core (5) as the plunger (7) approaches the second stroke end position (x2), so that the electromagnetic induction field has an increasing number of force lines (L1) which close in the air gap (8) between the fixed core (5) and the plunger (7) by crossing the first surface portion (15, 16) of the fixed core (5) orthogonally to said axis (6).