| 摘要 |
A roof segment 12 for a vehicle (74, Figure 12), typically a car, station wagon, multi-purpose vehicle (MPV), sports utility vehicle (SUV) or other motor vehicle, has a flat base element 14 with a wall created from a single, plastically deformed starting material, forming a closed hollow cross section enclosing one or more cavities 16. Roof segment 12 may be formed by rollforming a single flat blank, suitably of sheet metal such as aluminium or magnesium or an alloy containing a lightweight metal, and connecting ends 32, 34 of the material using adhesive, rivets or laser welding, alternatively roof segment 12 may be formed by extruding a pellet or by hot forming using a high pressure process. A roof module 45 comprising roof segment 12 is also provided. Roof segment 12 may be lightweight while providing adequate torsional stiffness. |
