Proportional valve for controlling a gaseous medium and fuel cell arrangement

1. A proportional valve ( 100 ) for controlling a gaseous medium, the proportional valve comprising

a valve housing ( 104 ) at least partially defining an inflow space ( 401 ),

a movable closing element ( 301 ) and a first spring ( 302 ) which is arranged on the closing element ( 301 ), the first spring ( 302 ) being configured to exert a first spring force on the closing element ( 301 ) in a closing direction, and

an actuator ( 200 ), the actuator ( 200 ) being configured to provide an adjustable force on the closing element ( 301 ), which adjustable force is directed counter to the first spring force,

wherein the closing element ( 301 ) moves towards a valve seat ( 103 ) in the closing direction and is configured to close and to open a passage opening ( 102 ) by way of movement of the closing element ( 301 ),

characterized in that the proportional valve ( 100 ) also comprises

a closure element ( 305 ) which is arranged at one end of the closing element ( 301 ) in the inflow space ( 401 ) and which is configured to move on and off of the valve seat ( 103 ), and

a second spring ( 304 ) being arranged on the closure element ( 305 ), and the second spring ( 304 ) being configured to exert a second spring force on the closure element ( 305 ), the second spring force acting counter to the first spring force,

wherein the passage opening ( 102 ) communicates with the inflow space ( 401 ) when the passage opening ( 102 ) is opened by movement of the closure element ( 305 ) off the valve seat ( 103 ),

wherein supply pressure is a pressure in the inflow space ( 401 ) and exerts on the closure element ( 305 ) a nonzero closing force in the closing direction,

wherein throughflow of the gaseous medium through the proportional valve ( 100 ) exerts on the closure element ( 305 ) a nonzero closing force in the closing direction, and

wherein the second spring force is greater than a sum of the nonzero closing forces exerted on the closure element ( 305 ) by the supply pressure and by the throughflow.

2. The proportional valve ( 100 ) as claimed in claim 1 , characterized in that the closing element ( 301 ) and the closure element ( 305 ) are arranged on one another by way of the first spring force and the second spring force.

3. The proportional valve ( 100 ) as claimed in claim 1 , characterized in that the first spring force is greater than the second spring force.

4. The proportional valve ( 100 ) as claimed in claim 1 , characterized in that the closure element ( 305 ) comprises a supporting structure ( 303 ), the second spring ( 304 ) being operatively connected to the closure element ( 305 ) via the supporting structure ( 303 ).

5. The proportional valve ( 100 ) as claimed in claim 1 , characterized in that the closure element ( 305 ) is of pot-shaped configuration.

6. The proportional valve ( 100 ) as claimed in claim 1 , characterized in that an elastic element ( 306 ) is arranged on a face of the closure element ( 305 ) facing the passage opening ( 102 ).

7. The proportional valve ( 100 ) as claimed in claim 1 , characterized in that the inflow space ( 401 ) and the closing element ( 301 ) are arranged on a first side of the passage opening ( 102 ), and an outflow space ( 402 ) is configured on a second side of the passage opening ( 102 ), wherein the second side faces away from the first side, such that the inflow space ( 401 ) and the outflow space ( 402 ) are configured to be connected to one another via the passage opening ( 102 ).

8. The proportional valve ( 100 ) as claimed in claim 1 , characterized in that a contact point ( 307 ) of the closing element ( 301 ) with the closure element ( 305 ) is of crowned configuration.

9. The proportional valve ( 100 ) as claimed in claim 1 , characterized in that the actuator ( 200 ) comprises a magnet coil ( 201 ) and a magnet armature ( 202 ), the magnet armature ( 202 ) being connected fixedly to the closing element ( 301 ), such that the magnet armature ( 202 ) is configured to be moved in a reciprocating movement by way of the magnet coil ( 201 ).

10. A fuel cell arrangement having a proportional valve ( 100 ) as claimed in claim 1 .