A device for coupling tilting railroad cars onto a high-speed railroad train comprises a coupler and a shock absorber held in a shock absorber frame, each joined by a coupling pin via a coupling joint. The frame includes a front inner surface with a front end wall opening and a cylindrical surface extending to a semi-circular concave inner surface. The joint includes a rounded convex surface engaged with a semi-circular concave surface, a circumferential surface of a short cylinder receiving the rear portion of the coupler, and an insertion hole which is provided in a direction perpendicular to the axis of the short cylinder. The frame has a removal hole and an air removal pin of the coupling pin facing each other at a position to rotate at a predetermined angle in a circumferential direction in the assembled state, and at a position coaxial with the coupling pin in the assembled state.