Mixing element for an exhaust gas system

1. A mixing element for an exhaust system of an internal combustion engine, comprising:

first and second half-shells, wherein said first and second half-shells are identical parts;

an insertion plate arranged between said first and second half-shells;

wherein said first half-shell comprises:

first and second inlet opening sections;

first and second outlet opening sections; and

first and second channel sections that are open toward said second half-shell;

wherein said second half-shell comprises:

third and fourth inlet opening sections;

third and fourth outlet opening sections;

third and fourth channel sections that are open toward said first half-shell;

wherein, said first and third inlet opening sections define a first inlet opening and said second and fourth inlet opening sections define a second inlet opening;

wherein, said first and third outlet opening sections define a first outlet opening and said second and fourth outlet opening sections define a second outlet opening; and

wherein said first, second, third, and fourth channel sections of said first and second half-shells define a channel system comprising:

first, second, third and fourth channels respectively;

wherein said first and second channels connect said first inlet opening to said first and second outlet openings, respectively, and said third and fourth channels connect said second inlet opening to said first and second outlet openings, respectively.

2. The mixing element according to claim 1 , wherein said first and third channels connect said first outlet opening to said first and second inlet openings, respectively, and said second and fourth channels connect said second outlet opening to said first and second inlet openings, respectively.

3. The mixing element according to claim 1 , wherein said mixing element includes for each of said first and second inlet openings an inlet space from which a channel branches off to said first outlet opening and another channel branches off to said second outlet opening.

4. The mixing element according to claim 1 , wherein said mixing element includes for each of said first and second outlet openings an outlet space into which a channel coming from said first inlet opening opens and a channel coming from said second inlet opening opens.

5. The mixing element according to claim 1 , wherein said first and second channels assigned to said first inlet opening are arranged in a Y shape, said third and fourth channels assigned to said second inlet opening are arranged in a Y shape, said first and third channels assigned to said first outlet opening are arranged in a Y shape, and said second and fourth channels assigned to said second outlet opening are arranged in a Y shape.

6. The mixing element according to claim 1 , wherein said first and fourth channels run essentially parallel to one another, such that the exhaust gas stream through said first and fourth channels does not mix in said mixing element.

7. The mixing element according to claim 1 , wherein said second and third channels intersect one another, preferably in such a way that the exhaust gas streams through said second and third channels do not mix in said mixing element.

8. The mixing element according to claim 1 , wherein said insertion plate seals said first and second channel sections with regard to the other half-shell.

9. The mixing element according to claim 1 , wherein said insertion plate divides the exhaust gas stream into said first and second channels for said first inlet opening and into said third and fourth channels for said second inlet opening.

10. The mixing element according to claim 1 , wherein said first, second, third and fourth channels have flow cross sections of approximately same size.

11. The mixing element of claim 1 , wherein each of said first and second half-shells is a single stamped part.

12. An exhaust system for an internal combustion engine, comprising:

first and second exhaust lines which are connected to one another via a mixing element, said mixing element comprising:

first and second half-shells, wherein said first and second half-shells are identical parts;

an insertion plate arranged between said first and second half-shells;

wherein said first half-shell comprises:

first and second inlet opening sections;

first and second outlet opening sections; and

first and second channel sections that are open toward said second half-shell;

wherein said second half-shell comprises:

third and fourth inlet opening sections;

third and fourth outlet opening sections;

third and fourth channel sections that are open toward said first half-shell;

wherein, said first and third inlet opening sections define a first inlet opening and said second and fourth inlet opening sections define a second inlet opening;

wherein, said first and third outlet opening sections define a first outlet opening and said second and fourth outlet opening sections define a second outlet opening; and

wherein said first, second, third, and fourth channel sections of said first and second half-shells define a channel system comprising:

first, second, third and fourth channels;

wherein said first and second channels connect said first inlet opening to said first and second outlet openings, respectively, and said third and fourth channels connect said second inlet opening to said first and second outlet openings, respectively.

13. The exhaust system according to claim 12 , further comprises a probe or sensor arranged downstream from said mixing element in at least one of said first and second exhaust lines.

14. The exhaust system according to claim 13 , wherein said probe or sensor is adapted for measuring a urea content and/or ammonia content in the exhaust gas.

15. The exhaust system according to claim 12 , wherein each of said first and second exhaust lines comprises first and second catalytic converter arrangement upstream from said mixing element.

16. The exhaust system according to claim 15 , wherein each of said first and second catalytic converter arrangements operates with at least one of urea and ammonia to reduce nitrogen oxides.