A chassis for a motor vehicle comprises two lateral longitudinal members. The following elements extend between these members and are affixed to them: the front and rear floor parts; a cross member known as the heel board cross member having upper and lower longitudinal sides which are fixed to the front and rear floor parts, respectively; and a cross member, having a length approximately equal to that of the heel board cross member, which extends underneath the lower longitudinal side of the heel board cross member and is affixed to it. Each of the ends of the cross member is fixed to one of the lateral longitudinal members. The invention also relates to station wagon-type motor vehicle having such a chassis.

A wire and pipe-laying structure for a fuel cell vehicle including a rear frame which is disposed at a back of the fuel cell vehicle and extends in a longitudinal direction of the fuel cell vehicle; a side sill which is disposed at a side of the fuel cell vehicle; and a floor frame which is disposed inside the side sill and extends in a longitudinal direction of the fuel cell vehicle. The floor frame together with the side sill are connected to a front end of the rear frame so as to form a Y-shaped frame having a crotch portion. A fuel pipe or a high-voltage wiring is disposed so as to pass through the crotch portion of the Y-shaped frame, and the fuel pipe or high-voltage wiring connects a fuel tank for fuel gas or a storage device to a fuel cell box.

In a vehicle frame structure, an upper edge of a frame member is fixed to a lower face of a substantially flat panel, and a bottom wall of an upper stiffener fixed to an inner face of an upper part of a curved portion of the frame member and a bottom wall of a lower stiffener fixed to an outer face of a lower part of a region between two inflection points of the curved portion are arranged in an X shape relative to a top point of the curved portion. Therefore, when a compressive load in the longitudinal direction acts on the frame member, the curved portion of the frame member is effectively prevented from bending by counterbalancing the upward load acting on the lower stiffener bottom wall with the downward load acting on the upper stiffener bottom wall. Moreover, the upper stiffener and the lower stiffener are U-shaped cross-section members that can be formed by bent sheet metal, and thereby minimize any increase in weight due to installation of the stiffeners.