Motor vehicle chassis, comprising means for distributing against a tunnel a force applied by a crossmember in the event of a side impact

The invention relates to a motor vehicle chassis (3), comprising an underbody frame covered by a floor (7) secured to the frame. The frame comprises side rails (4) and at least one longitudinal tube (5) placed at a transverse distance from one such rail (4) to which the tube (5) is connected via a crossmember (6) which is secured by one of the ends (6a) thereof to the tube (5) and by the other end (6b) thereof to the rail (4). The crossmember (6) forms a first member for transmitting to the tube (5) a first thrust force (EP1) generated by an impact applied laterally against the chassis (3). A strut (8) is jointly secured by the respective ends (8a, 8b) thereof to the crossmember (6) and to the tube (5), and is inclined with respect to the main direction in which they extend in a plane parallel to the floor (7). The strut (8) forms a second member for transmitting to the tube (5) a second thrust force (EP2) generated by said impact and transmitted to the strut (8) by the crossmember (6).