Filter cartridge for a reducing agent delivery device and delivery device and motor vehicle having a filter cartridge

1. A filter cartridge for a delivery device for a reducing agent, the filter cartridge comprising:

at least one filter wall and at least one supporting wall together forming an interior space receiving reducing agent filtered by said at least one filter wall;

said at least one supporting wall having an outflow opening discharging the filtered reducing agent out of said interior space and a bypass opening discharging the filtered reducing agent out of said interior space when a predefined excess pressure prevails in said interior space;

said outflow opening having a first diameter and said bypass opening having a second diameter being less than one tenth of said first diameter;

said outflow opening configured to be coupled to the delivery device and said bypass opening bypassing said outflow opening.

2. The filter cartridge according to claim 1 , which further comprises a screen element covering said bypass opening.

3. The filter cartridge according to claim 2 , wherein said screen element is welded or vulcanized to said at least one supporting wall.

4. The filter cartridge according to claim 1 , wherein said bypass opening has a diameter of at least 100 μm [micrometers].

5. The filter cartridge according to claim 1 , wherein:

said filter wall has a cylindrical basic shape;

said at least one supporting wall includes two supporting walls each forming a respective one of a top side and a bottom side; and

said outflow opening is disposed at said top side and said bypass opening is disposed at said bottom side.

6. The filter cartridge according to claim 1 , wherein said supporting wall has a receptacle, and a compressible insert is disposed in said receptacle.

7. A delivery device for a reducing agent, the delivery device comprising:

at least one filter cartridge according to claim 1 ; and

a suction point and a discharge point defining a delivery path for the reducing agent from said suction point to said discharge point;

said delivery path running through said at least one filter cartridge.

8. A motor vehicle, comprising:

an internal combustion engine;

an exhaust-gas treatment device for purification of exhaust gases of said internal combustion engine; and

a delivery device for delivering reducing agent into said exhaust-gas treatment device, said delivery device including:

at least one filter cartridge according to claim 1 , and

a suction point and a discharge point defining a delivery path for the reducing agent from said suction point to said discharge point,

said delivery path running through said at least one filter cartridge.

9. The filter cartridge according to claim 1 , wherein the predefined excess pressure prevailing in said interior space is caused by reducing agent freezing in said interior space.

10. A filter cartridge for a delivery device for a reducing agent, the filter cartridge comprising:

at least one filter wall and at least one supporting wall together forming an interior space receiving reducing agent filtered by said at least one filter wall;

said at least one supporting wall having an outflow opening discharging the filtered reducing agent out of said interior space and an always open bypass opening discharging the filtered reducing agent out of said interior space when a predefined excess pressure prevails in said interior space, said bypass opening being smaller than said outflow opening, said bypass opening having a screen spanning said bypass opening for preventing impurities from entering said interior space through said bypass opening;

said outflow opening configured to be coupled to the delivery device and said bypass opening bypassing said outflow opening.

11. The filter cartridge according to claim 10 , wherein said outflow opening has a first diameter and said bypass opening has a second diameter that is less than one tenth of said first diameter.

12. The filter cartridge according to claim 1 , wherein said bypass opening is always open.

13. The filter cartridge according to claim 1 , wherein said supporting wall has a receptacle, and a compressible insert is disposed in said receptacle, said compressible insert dissipates ice pressure of the reducing agent by the reducing agent acting directly upon the said compressible insert.

14. The filter cartridge according to claim 1 , wherein said supporting wall has a receptacle, and a compressible insert is disposed in said receptacle, said compressible insert being rubber or a compressible bellows.