Trailer coupling with a coupling arm

1. A trailer coupling for a motor vehicle, comprising a coupling arm, on a first longitudinal end region of which a coupling body, for coupling a trailer or load carrier a second longitudinal end region having a holding end for holding and/or moveable mounting on a supporting structure of the motor vehicle, wherein the coupling arm comprises supporting straps which extend along a longitudinal extent of the coupling arm at a transverse distance to each other between the first and second longitudinal end regions, wherein the supporting straps are connected to each other by a plurality of connecting struts in the manner of a lattice structure or rib structure, wherein a cross section of the coupling arm through at least one connecting strut, which connects the carrying straps lying opposite each another at a transverse distance, is triangular or V-shaped.

2. The trailer coupling according to claim 1 , wherein a through-opening is provided between at least two connecting struts of the plurality of connecting struts.

3. The trailer coupling according to claim 1 , wherein the coupling arm has at least one receptacle for a contact unit for producing electrical and/or optical connections between an on-board electrical system of the motor vehicle and a trailer or load carrier.

4. The trailer coupling according to claim 3 , wherein the receptacle is delimited on at least one side by a connecting strut extending between the supporting straps.

5. The trailer coupling according to claim 3 , wherein the transverse distance between the supporting straps in the region of the receptacle for the contact unit is greater than in relation to the longitudinal extent of the coupling arm adjacent to the receptacle for the contact unit.

6. The trailer coupling according to claim 3 , wherein the coupling arm comprises at least one connecting strut at a distance from the receptacle for the contact unit with respect to the longitudinal extent of the coupling arm.

7. The trailer coupling according to claim 1 , wherein two of the supporting straps have a different transverse width with respect to the longitudinal extent of the coupling arm.

8. The trailer coupling according to claim 1 , wherein a plug-in projection is arranged on the holding end for insertion into a plug-in receptacle of a holder of the trailer coupling, which is attached or can be attached to the motor vehicle, or a mounting head for movable mounting on a mount, which is attached or can be attached to a motor vehicle, or at least one assembly contour for assembly on the motor vehicle.

9. The trailer coupling according to claim 1 , wherein the coupling body comprises a coupling ball.

10. A trailer coupling for a motor vehicle, comprising a coupling arm, on a first longitudinal end region of which a coupling body, for coupling a trailer or load carrier a second longitudinal end region having a holding end for holding and/or moveable mounting on a supporting structure of the motor vehicle, wherein the coupling arm comprises supporting straps which extend along a longitudinal extent of the coupling arm at a transverse distance to each other between the first and second longitudinal end regions, wherein the supporting straps are connected to each other by a plurality of connecting struts in the manner of a lattice structure or rib structure, wherein a supporting strap of the supporting straps transverse to the longitudinal extent of the coupling arm is at least twice as wide as another supporting strap of the supporting straps.

11. The trailer coupling according to claim 10 , wherein the coupling arm has a uniform cross section without a depression and/or any connecting strut on one or both of the first and second longitudinal end regions.

12. The trailer coupling according to claim 10 , wherein a cross section of the coupling arm through at least one connecting strut, which connects the carrying straps lying opposite each another at a transverse distance, is triangular or V-shaped.

13. A trailer coupling for a motor vehicle, comprising a coupling arm, on a first longitudinal end region of which a coupling body, for coupling a trailer or load carrier a second longitudinal end region having a holding end for holding and/or moveable mounting on a supporting structure of the motor vehicle, wherein the coupling arm comprises supporting straps which extend along a longitudinal extent of the coupling arm at a transverse distance to each other between the first and second longitudinal end regions, wherein the supporting straps are connected to each other by a plurality of connecting struts in the manner of a lattice structure or rib structure, wherein the coupling arm comprises at least three supporting straps which run along edge regions of the coupling arm and of which at least two supporting straps are connected to each other by a plurality of connecting struts.

14. The trailer coupling according to claim 13 , wherein the coupling arm has at least one curved portion along the longitudinal extent.

15. A trailer coupling for a motor vehicle, comprising a coupling arm, on a first longitudinal end region of which a coupling body, for coupling a trailer or load carrier a second longitudinal end region having a holding end for holding and/or moveable mounting on a supporting structure of the motor vehicle, wherein the coupling arm comprises supporting straps which extend along a longitudinal extent of the coupling arm at a transverse distance to each other between the first and second longitudinal end regions, wherein the supporting straps are connected to each other by a plurality of connecting struts in the manner of a lattice structure or rib structure, wherein the coupling arm has at least one receptacle for a contact unit for producing electrical and/or optical connections between an on-board electrical system of the motor vehicle and a trailer or load carrier, wherein the transverse distance between the supporting straps in the region of the receptacle for the contact unit is greater than in relation to the longitudinal extent of the coupling arm adjacent to the receptacle for the contact unit.

16. The trailer coupling according to claim 15 , wherein at least one wall section is provided transverse to the longitudinal extent of the coupling arm between at least two connecting struts of the plurality of connecting struts arranged one behind another along the longitudinal extent, wherein at least one connecting strut projects to at least one side in front of the wall section transversely to the longitudinal extent.

17. The trailer coupling according to claim 16 , wherein the connecting struts arranged adjacent one another along the longitudinal extent each project from the at least one wall section on opposite sides.

18. The trailer coupling according to claim 16 , wherein at least one of the supporting straps, project in front of the at least one wall section on at least one side.

19. The trailer coupling according to claim 16 , wherein the supporting straps and the wall section form a T-shaped or double T-shaped or bone-shaped cross section.

20. The trailer coupling according to claim 16 , wherein the wall section is narrower than at least one of the supporting straps and in a region furthest away from this supporting strap, the other supporting strap is configured as an integral part of the wall section or is formed by the wall section.

21. The trailer coupling according to claim 16 , wherein the wall section projects approximately at right angles and/or approximately centrally from a longer side or flat side of at least one of the supporting straps.

22. The trailer coupling according to claim 15 , wherein at least two connecting struts are adjacent to each other along the longitudinal extent to transmit tensile forces and/or compressive forces and/or tensile stresses and/or compressive stresses and/or torsions between the supporting straps to compensate for a load.

23. The trailer coupling according to claim 15 , wherein at least one connecting strut has an oblique inclination with respect to the longitudinal extent of the coupling arm or is oriented with respect to the longitudinal extent of the coupling arm approximately at right angles to at least one supporting strap.

24. The trailer coupling according to claim 15 , wherein the coupling arm has at least two connecting struts arranged one behind another along the longitudinal extent which have an oblique inclination in an opposite direction with respect to the longitudinal extent of the coupling arm.

25. The trailer coupling according to claim 24 , wherein the connecting struts cross or are arranged one behind another without crossing with respect to the longitudinal extent and/or that the connecting struts are arranged in an X-shaped or V-shaped manner.

26. The trailer coupling according to claim 15 , wherein at least two connecting struts arranged adjacent to each other with respect to the longitudinal extent, have an oblique inclination in a same direction with respect to the longitudinal extent of the coupling arm.

27. The trailer coupling according to claim 15 , wherein at least one of the supporting straps extends on an upper side or lower side of the coupling arm upon the coupling arm projecting in front of a rear of the motor vehicle for supporting a load carrier or for pulling a trailer.

28. The trailer coupling a claim 15 , wherein a supporting strap of the supporting straps transverse to the longitudinal extent of the coupling arm is at least twice as wide another supporting strap of the supporting straps.

29. The trailer coupling according to claim 15 , wherein at least one connecting strut and/or at least one supporting strap has a rounded or curved outer contour on at least one transverse outer side and/or in that at least one connecting strut on a foot region, on which it is connected to one of the supporting straps, has a larger cross section than at an intermediate section extending between the supporting straps.

30. The trailer coupling according to claim 15 , wherein a number of connecting struts and/or a cross-section or a cross-sectional area of the connecting struts is larger in a region of the holding end than in a region of the coupling body.

31. The trailer coupling according to claim 15 , wherein a web projects at an angle from one supporting strap wherein a section of the web furthest away from the supporting strap forms or comprises the other supporting strap.

32. The trailer coupling according to claim 15 , wherein the coupling arm comprises at least three supporting straps which run along edge regions of the coupling arm and of which at least two supporting straps are connected to each other by a plurality of connecting struts.

33. The trailer coupling according to claim 15 , wherein at least one connecting strut projects approximately at right angles and/or approximately centrally from a longer side or flat side of at least one of the supporting straps.

34. The trailer coupling according to claim 15 , wherein the coupling arm has at least three connecting struts along the longitudinal extent.

35. The trailer coupling according to claim 15 , wherein the coupling arm and the connecting struts are made of metal and/or plastic.