Filling head for filling a tank with a liquid

1. A filling head for filling a tank with a liquid, the filling head delimiting:

a conduit for filling the tank which extends axially along a filling axis from an upstream section which is adapted to receive a filling nozzle, up to a downstream section which is designed to be connected on the tank to fill,

an annular sealing collar which extends around the filling axis and which is designed to form an annular lip seal which conforms to the peripheral face of the nozzle, and

a degassing circuit including an inlet which is adapted to be connected on the tank and an outlet in communication with the outside, as well as a filling chamber which is interposed between the inlet and the outlet and in communication with these latter, said outlet being formed by a degassing window located upstream with respect to the sealing collar and arranged so as to allow the gases to escape from the chamber to the outside,

the filling head wherein it delimits, downstream of the sealing collar, at least one suction window which connects the chamber of the degassing circuit to the downstream section of the filling conduit, and which is arranged at the outlet of the nozzle, so as to promote the suction via the degassing circuit of the gases which escape from the tank, during the filling of the tank.

2. The filling head according to claim 1 , wherein it includes a stop which projects radially in the filling conduit so as to limit the axial course of the filling nozzle and in that the suction window is arranged directly downstream of said stop.

3. The filling head according to claim 1 , wherein the filling chamber communicates with the downstream conduit section through the suction window so as to enable the filling of said filling chamber with liquid repelled from the filling conduit.

4. The filling head according to claim 1 , wherein the upstream section of the filling conduit delimits at least one degassing window which forms the outlet of the degassing circuit.

5. The filling head according to claim 4 , wherein it includes:

at least one retaining finger which bears axially on the magnet so as to retain the magnet in its recess, and

a sealing ring which is elastically-deformable and which forms the degassing window, the sealing collar and the retaining finger, in one piece.

6. The filling head according to claim 1 , wherein the filling chamber is formed by an annular cavity which extends around the filling conduit and which is delimited by an annular inner wall which separates it from said conduit and throughout the thickness of which the suction window is pierced.

7. The filling head according to claim 1 , wherein it is equipped with a permanent magnet which is inserted in a recess of the upstream section of the filling conduit and which is adapted to act on a device for automatically turning off the filling nozzle.

8. The filling head according to claim 7 , wherein it includes at least one retaining finger which bears axially on the magnet so as to retain the magnet in its recess.

9. The filling head according to claim 1 , wherein the distance which separates axially, along the axis, a reference position, corresponding to the downstream end of the nozzle, from a downstream opening limit of the suction window, said downstream opening limit being located downstream of said reference position, is smaller than or equal to 130% of the inner diameter of the nozzle.

10. Using, within a filling head according to claim 1 connected to a tank, a liquid flow injected in the filling conduit of said head by a filling nozzle to generate, thanks to the flow speed of said liquid, a depression in the degassing circuit, through a suction window that is arranged in the wall of the filling conduit directly at the outlet of said nozzle, so as to promote the suction via the degassing circuit of the gases escaping from the tank.

11. A device for depollution by selective catalytic reduction for a motor vehicle or heavy-goods vehicle including a filling head according to claim 1 .