Device for controlled deformation by forces or for absorption of energy by deformation, especially obstacle deflector for a railway vehicle

This device is an obstacle deflector (10) which comprises a shield in the form of a rigid box-shaped structure (11) that is movable and disposed transversely to the vehicle, and whose displacement in the event of a crash is transformed into rotation about a pitch axis, by means of a hinge, the movement of the shield taking place against four torsion bars (18, 23) interposed in a mechanical connection between the shield and the chassis (2).