Vehicle chassis with energy management

摘要

According to the invention, a vehicle chassis includes first and second longitudinal extending side rails which are laterally spaced apart. A cross member extends transversely between the first and second side rails and has bolt holes therein. A longitudinally extending slotted aperture is provided in each side rail and registers with the bolt holes of the cross member. Each of the side rails has a cage member attached thereto and overlying aligned the slotted aperture. Each cage member has a longitudinally extending slotted aperture registering with the slotted aperture of the side rail and each has a nut captured therein for longitudinal movement of the nut within the cage member along the slotted aperture. A bolt is installed through the cross member bolt hole, through the slotted aperture of the side rail, and into the nut to attach the cross member and the side rail. Impact force applied against the cross member induces forced longitudinal movement of the cross member relative to the side rail as permitted by longitudinal movement of the bolt along the slotted aperture. At least one of the slotted apertures is constricted by a metal web or other constriction which normally blocks longitudinal movement of the bolt and then yields so that the relative longitudinal movement of the bolt causes yielding of the metal to absorb energy.