Bottom assembly unit for a combustion chamber assembly unit of a vaporizing burner

1. A bottom assembly unit for a vaporizing burner combustion chamber assembly unit for a vehicle heater, the bottom assembly comprising:

a bottom part comprising a bottom wall;

a porous evaporator medium at least partially covering the bottom wall on a bottom wall front side that is to be positioned facing a combustion chamber;

a fuel feed line opening into the bottom wall for feeding liquid fuel into the porous evaporator medium; and

a ring-shaped holding part comprising a circumferential wall and a contact area touching the porous evaporator medium, wherein the contact area comprises a contact section extending radially inwardly from the circumferential wall and extending over the porous evaporator medium in a radially outer area, and a plurality of contact projections arranged at spaced locations following one another about a longitudinal axis and extending in a direction towards the porous evaporator medium, wherein the porous evaporator medium is pressed against the bottom wall at least by the contact projections in the radially outer area.

2. A bottom assembly unit in accordance with claim 1 , wherein the porous evaporator medium is pressed by the contact projections and the contact section in the radially outer area against the bottom wall, whereby the porous evaporator medium is in direct contact with the bottom wall.

3. A bottom assembly unit in accordance with claim 1 , wherein the contact area is at least one of formed in at least some areas by a curved end area of the circumferential wall of the holding part and has a ring-shaped design and extends about the longitudinal axis.

4. A bottom assembly unit in accordance with claim 1 , wherein at least one of the contact projections extends, starting from a radially inner end area of the contact section at least one of radially inwardly and in the direction of the porous evaporator medium.

5. A bottom assembly unit in accordance with claim 1 , wherein at least one of the contact projections comprises at least one contact tip.

6. A bottom assembly unit in accordance with claim 1 , further comprising an intermediate contact element covering the porous evaporator medium in a radially outer area thereof, the intermediate contact element being held between the contact section and the porous evaporator medium, the bottom part comprising a bottom part circumferential wall connected to the bottom wall, the bottom part circumferential wall being located radially inward of the circumferential wall of the ring-shaped holding part with respect to the longitudinal axis.

7. A bottom assembly unit in accordance with claim 6 , wherein the intermediate contact element is ring-shaped, at least an outer portion of the bottom part circumferential wall being in direct contact with an inner portion of the circumferential wall of the ring-shaped holding part.

8. A bottom assembly unit in accordance with claim 6 , further comprising:

a second holding part comprising a second holding part circumferential wall, the second holding part circumferential wall being located radially inward of the bottom part circumferential wall and the circumferential wall of the ring-shaped holding part with respect to the longitudinal axis, wherein the intermediate contact element is made of a porous material.

9. A bottom assembly unit in accordance with claim 6 , further comprising:

a second holding part comprising a second holding part circumferential wall, the second holding part circumferential wall being located radially inward of the bottom part circumferential wall and the circumferential wall of the ring-shaped holding part with respect to the longitudinal axis, at least an outer portion of the bottom part circumferential wall being in direct contact with an inner portion of the circumferential wall of the ring-shaped holding part, at least an outer portion of the second holding part circumferential wall being in direct contact with an inner portion of the bottom part circumferential wall, wherein at least one of the contact projections passes through the intermediate contact element or presses the intermediate contact element into the porous evaporator medium.

10. A bottom assembly unit in accordance with claim 1 , wherein at least one of the contact projections penetrates into the porous evaporator medium.

11. A bottom assembly unit in accordance with claim 1 , wherein:

the bottom part comprises a bottom part circumferential wall, which extends from an outer edge area of the bottom wall essentially in the direction of a longitudinal axis of the bottom assembly unit;

the bottom part circumferential wall extends, starting from the bottom wall, in the direction away from the porous evaporator medium on a rear side of the bottom wall, which said rear side is to be positioned such that the rear side faces away from the combustion chamber; and

the circumferential wall of the holding part extends axially at least partially over the bottom part circumferential wall on an outer side thereof and is fixed to same.

12. A bottom assembly unit in accordance with claim 1 , wherein at least one of the bottom part and the holding part comprises a shaped sheet metal part, shaped from steel plate or in a deep-drawing operation.

13. A vaporizing burner combustion chamber assembly unit for a vehicle heater, the combustion chamber assembly unit comprising:

a combustion chamber circumferential wall; and

a bottom assembly comprising:

a bottom part comprising a bottom wall;

a porous evaporator medium at least partially covering the bottom wall on a bottom wall front side that is to be positioned facing a combustion chamber;

a fuel feed line opening into the bottom wall for feeding liquid fuel into the porous evaporator medium; and

a ring-shaped holding part comprising a circumferential wall and a contact area touching the porous evaporator medium, wherein the contact area comprises a contact section extending radially inwardly from the circumferential wall and extending over the porous evaporator medium in a radially outer area, and a plurality of contact projections arranged at spaced locations following one another about a longitudinal axis and extending in a direction towards the porous evaporator medium, wherein the porous evaporator medium is pressed against the bottom wall at least by the contact projections in the radially outer area, wherein the combustion chamber circumferential wall extends at least partially over the circumferential wall of the holding part and is fixed to same.

14. A combustion chamber assembly unit in accordance with claim 13 , wherein the contact area is at least one of formed in at least some areas by a curved end area of the circumferential wall of the holding part and has a ring-shaped design and extends about the longitudinal axis.

15. A combustion chamber assembly unit in accordance with claim 13 , wherein at least one of the contact projections comprises at least one contact tip.

16. A combustion chamber assembly unit in accordance with claim 13 , further comprising an intermediate contact element covering the porous evaporator medium in a radially outer area thereof, the intermediate contact element being held between the contact section and the porous evaporator medium, the bottom part comprising a bottom part circumferential wall connected to the bottom wall, the bottom part circumferential wall being located radially inward of the circumferential wall of the ring-shaped holding part with respect to the longitudinal axis.

17. A combustion chamber assembly unit in accordance with claim 16 , wherein the intermediate contact element is ring-shaped, wherein at least an outer portion of the bottom part circumferential wall is in direct contact with an inner portion of the circumferential wall of the ring-shaped holding part.

18. A combustion chamber assembly unit in accordance with claim 16 , wherein the combustion chamber assembly unit further comprises a second holding part comprising a second holding part circumferential wall, the second holding part circumferential wall being located radially inward of the bottom part circumferential wall and the circumferential wall of the ring-shaped holding part with respect to the longitudinal axis, wherein the intermediate contact element is made of a porous material.

19. A combustion chamber assembly unit in accordance with claim 16 , wherein the combustion chamber assembly unit further comprises a second holding part comprising a second holding part circumferential wall, the second holding part circumferential wall being located radially inward of the bottom part circumferential wall and the circumferential wall of the ring-shaped holding part with respect to the longitudinal axis, at least an outer portion of the bottom part circumferential wall being in direct contact with an inner portion of the circumferential wall of the ring-shaped holding part, at least an outer portion of the second holding part circumferential wall being in direct contact with an inner portion of the bottom part circumferential wall, wherein at least one of the contact projections penetrates into the porous evaporator medium.

20. A combustion chamber assembly unit in accordance with claim 16 , wherein at least one of the contact projections passes through the intermediate contact element or presses the intermediate contact element into the porous evaporator medium, the combustion chamber assembly unit further comprising heat insulating material and a second holding part comprising a second holding part circumferential wall, the second holding part circumferential wall being located radially inward of the bottom part circumferential wall and the circumferential wall of the ring-shaped holding part with respect to the longitudinal axis, the heat insulating material being arranged between the bottom part and the second holding part.