Supporting frame for the chassis of a commercial vehicle

The carrier frame (1) has a pair of relatively spaced longitudinal supports (3) extending in the vehicle longitudinal direction (2), coupled via transverse supports (4). Each longitudinal support has upper and lower members (5,6) joined by a number of vertical elements (7), each lower member divided into a front section (8), a central section (10) and a rear section (9), with auxliary transverse supports between the central sections of both longitudinal supports forming a platform (12) for the engine block (13), fitted to the carrier frame as a pre-assembled unit.