Retractable aerodynamic underbody flap with force absorption by the lower support

1. The motor vehicle comprising an aerodynamic underbody flap ( 1 ) rotating about a transverse axis ( 10 ) and a lower transverse structure ( 4 ) arranged at the rear of a lower part of a front bumper ( 6 ) characterized in that a rear part of the lower transverse structure ( 4 ) comprises guide means ( 41 , 42 ) which, in a event of a frontal impact, guide backward movement of the lower transverse structure ( 4 ) such that a rear face of the lower transverse structure ( 4 ) comes into contact with the axis ( 10 ) of the aerodynamic underbody flap ( 1 ).

2. The motor vehicle according to claim 1 , wherein the axis of rotation ( 10 ) of the aerodynamic underbody flap ( 1 ) is mounted on bearings fixed onto a lower part of a frame ( 5 ) of a technical front face.

3. The motor vehicle according to claim 2 , wherein the frame ( 5 ) of the technical front face is fixed onto a rear part of an upper transverse structure ( 3 ).

4. The motor vehicle according to claim 3 , wherein the upper transverse structure ( 3 ) is fixed onto a front end of longitudinal side members ( 2 ) by means of crash boxes ( 30 ).

5. The motor vehicle according to claim 3 , wherein the frame ( 5 ) of the technical front face is arranged at a distance of more than 100 mm from the front end of said longitudinal side members ( 2 ).

6. The motor vehicle according to claim 2 , wherein the frame ( 5 ) of the technical front face is fixed directly onto longitudinal side members ( 2 ).

7. The motor vehicle according to claim 2 , wherein the guide means ( 41 , 42 ) are formed by one or more upper clamps ( 41 ) and by one or more lower clamps ( 42 ) extending the lower structure respectively above and below the axis ( 10 ) of the aerodynamic underbody flap ( 1 ).

8. The motor vehicle according to claim 7 , wherein the aerodynamic underbody flap ( 1 ) has windows ( 12 ) arranged near the axis ( 10 ) to allow the passage of the lower clamps through the flap ( 1 ) when said aerodynamic underbody structure ( 1 ) is in the open position.

9. The motor vehicle according to claim 7 , wherein the lower clamps ( 42 ) and the upper clamps ( 41 ) are arranged transversely and alternately.

10. The motor vehicle according to claim 7 , wherein the lower clamps ( 42 ) and the upper clamps ( 41 ) extend around the rear part of the axis ( 10 ) of the aerodynamic underbody flap ( 1 ).

11. The motor vehicle according to claim 7 , wherein the aerodynamic underbody flap ( 1 ) is made using a thermoplastic material.

12. The motor vehicle according to claim 11 , wherein the axis ( 10 ) of the aerodynamic underbody flap comprises an inserted reinforcement piece ( 13 ) in the form of a rod made of metal or a composite material around which is molded a thermoplastic part forming the aerodynamic underbody flap ( 1 ).