Electromagnetic actuator device and use of such a device

An electromagnetic actuator device, comprising:

• armature means (18);
• an actuator housing (10);
• stationary core means (14) axially fixed relative to the actuator housing (10), the armature means (18) being movable in the actuator housing (10) along an axial direction relative to the stationary core means (14) as a reaction to stationary coil means (12) being energized;
• axially elongated plunger means (20) guided in a core passage (50) of the core means (14) and contacting the armature means (18) such that movement of the armature means (18) in the direction of the core means (14) entrains the plunger means (20),
• wherein the plunger means (20) has an end section (26) axially opposite the armature means (18), the end section (26) being configured to interact with a control partner, wherein the plunger means (20) further comprise an elongated rod section (34) and a disk-shaped end section (30) having a widened diameter, the disk-shaped end section (30) sitting on the elongated rod section (34) as one piece on an end of the plunger means (20) facing the armature means (18),
• wherein an axial extension (W) of the disk-shaped end section (30) determines a minimum distance between the armature means (18) and the core means (14) in an abutment state of the armature means (18) on an end surface and/or front surface of the core means (14) facing the armature means (18),
• wherein the plunger means (20) are made of a polymer material,
• wherein the elongated rod section (34) has a recess facing the core means (14), the recess comprising a longitudinal groove (36, 38) extending along the elongated rod section (34) such that pressure is equalized between an armature space (40) which is defined by the armature means (18) and the core means (14), and an engagement area axially spaced beyond the end section (26) of the plunger means (20),
• wherein the armature means (18) have an armature passage (32) which extends in the axial direction, and wherein the plunger means (20) overlaps, at least in sections, an opening on a plunger side of the armature passage (32) in an area of the disk-shaped end section (30),
• wherein the plunger means (20) have a plunger passage (52, 54) extending axially through the disk-shaped end section (30) such that the plunger passage (52, 54) opens the armature passage (32) towards the armature space (40) between the armature means (18) and the core means (14) while equalizing the pressure when the armature means (18) are contacted by the plunger means (20), and
• wherein the disk-shaped end section has an annular step (50) defined by substantially parallel axially spaced circumferential surfaces, and wherein the annular step extends around a full circumference of the disk-shaped end section.