Electromagnetic actuating unit of a solenoid valve, and method for the production of such an actuating unit

1. An electromagnetic actuating unit of a solenoid valve, comprising:

an armature, which is arranged within an armature space in an axially displaceable manner; and

a pole core which bounds the armature space in one direction of movement of the armature,

wherein a geometry of the armature is selected in such a way that nonlinearities in a force/displacement characteristic curve of the electromagnetic actuating unit are reduced as a result, the armature having an encircling recess forming a groove in an outer circumferential surface of the armature at an end which faces the pole core.

2. The electromagnetic actuating unit of claim 1 , wherein the encircling recess of the armature is an encircling sawtooth-shaped recess at an end which faces the pole core.

3. The electromagnetic actuating unit of claim 1 , wherein the encircling recess of the armature is an encircling V-shaped recess at an end which faces the pole core.

4. The electromagnetic actuating unit of claim 1 , wherein the encircling recess of the armature is an encircling recess in the form of an arc of a circle at an end which faces the pole core.

5. The electromagnetic actuating unit of claim 1 , wherein the electromagnetic actuating unit is part of a hydraulic directional valve.

6. The electromagnetic actuating unit of claim 5 , wherein the electromagnetic actuating unit is arranged on a cylinder head of an internal combustion engine.

7. The electromagnetic actuating unit of claim 5 , wherein the hydraulic directional valve is a camshaft adjuster for internal combustion engines.

8. The electromagnetic actuating unit of claim 1 , wherein the electromagnetic actuating unit is part of a solenoid valve for controlling switchable valve clearance compensation elements in internal combustion engines.

9. The electromagnetic actuating unit of claim 8 , wherein the switchable valve clearance compensation elements are switchable bucket tappets, switchable roller tappets or switchable cam followers.

10. The electromagnetic actuating unit of claim 1 , wherein the electromagnetic actuating unit is part of a 4/3-way valve, 412-way valve or 3/2-way valve.

11. The electromagnetic actuating unit of claim 1 , wherein the electromagnetic actuating unit comprises a proportional valve solenoid, and in that the proportional valve solenoid is part of a proportional directional valve.

12. The electromagnetic actuating unit of claim 1 , wherein the pole core is arranged in a holder.

13. A method for the production of an electromagnetic actuating unit of a hydraulic directional valve having an armature, which is arranged within an armature space in an axially displaceable manner, and a pole core which bounds the armature space in one direction of movement of the armature, comprising the following steps:

defining a desired force/displacement characteristic curve of the electromagnetic actuating unit;

determining a geometry of the armature which, in connection with the other magnetically active components of the actuating unit, leads to the defined characteristic curve, the geometry including an encircling recess forming a groove in an outer circumferential surface of the armature at an end which faces the pole core;

production of the armature with the geometry determined above;

assembly of the electromagnetic actuating unit.