More specifically, the present invention relates to a high-performance, central-engine vehicle body, to which the following description refers purely by way of example.

BACKGROUND ART As is known, high-performance, central-engine vehicle bodies normally comprise a supporting structure made of composite material and only involving the front and central part of the vehicle where the passenger compartment is formed; and the engine block which projects from the rear end of the supporting structure.

The front suspensions and all the other front and central component parts of the vehicle, including the body panels, are variously fixed to the composite- material supporting structure, while the rear suspensions, transmission, rear differential, and all the other rear component parts of the vehicle, including the body panels, are fixed directly to the engine block,

which in turn is fixed rigidly to the composite-material supporting structure by means of bolts or similar.

Though ensuring a high degree of rigidity and passenger safety, bodies of the above type have the major drawback of being practically impossible to repair in the event of collision. That is, the mechanical stress produced on impact is transmitted directly to the composite-material supporting structure, which is extremely rigid and lightweight, but also only deformable at the expense of being irreparably impaired structurally.

In the event of impact, in fact, the composite- material supporting structure collapses and disintegrates irreparably, so that, to repair the vehicle, the entire supporting structure must be replaced at exorbitant cost.

Another drawback of the above solution is that the engine block must be fixable firmly to the composite- material supporting structure, and must have a torsional and flexural rigidity comparable with that of the supporting structure, thus greatly increasing manufacturing cost as compared with a conventional engine block, which on average is also lighter than a structural engine block.

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide a vehicle body designed to eliminate the aforementioned drawbacks.

According to the present invention, there is

provided a vehicle body, characterized by comprising a rigid central cell made of composite materials; a front auxiliary frame anchored to the front end of said central cell; and a rear auxiliary frame anchored to the rear end of the central cell; the front auxiliary frame and the rear auxiliary frame being so deformable as to absorb, in the form of mechanical strain, the energy dissipated by the vehicle in the event of collision, without directly involving the central cell.

BRIEF DESCRIPTION OF THE DRAWINGS A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a view in perspective, with parts removed for clarity, of a vehicle body in accordance with the teachings of the present invention; Figure 2 shows a view in perspective of the Figure 1 body from a different angle; Figure 3 shows an exploded view of the vehicle body in the previous figures.

BEST MODE FOR CARRYING OUT THE INVENTION Number 1 in Figures 1 and 2 indicates as a whole a vehicle body particularly suitable for high-performance, central-or rear-engine vehicles.

Body 1 comprises a strong, rigid central cell 2 made of composite materials; a deformable front auxiliary frame 3 anchored to the front end of central cell 2; and a deformable rear auxiliary frame 4 anchored to the rear

end of central cell 2.

Central cell 2 is designed to form the rigid, undeformable structure of the passenger compartment of the vehicle, while front auxiliary frame 3 and rear auxiliary frame 4 are made at least partly of metal (e. g. aluminium) so as to absorb, in the form of mechanical strain, the energy dissipated by the vehicle in the event of collision, without directly involving central cell 2.

More specifically, front auxiliary frame 3 and rear auxiliary frame 4 are made at least partly of metal, so as to absorb all the energy dissipated by the vehicle in the event of medium-low impact, and to entrust passenger safety to central cell 2 in the event of medium-high impact, in which case, passenger safety takes precedence over preventing damage to the vehicle.

Front auxiliary frame 3 and rear auxiliary frame 4 may also provide for supporting the vehicle suspensions; the vehicle engine and auxiliary components, such as the coolant radiator; vehicle transmission members, such as the transmission case and/or differential; and the body panels.

In the example shown, central cell 2 is preferably, though not necessarily, made of carbon fiber, and at the rear has two parallel, facing longitudinal members 5 projecting horizontally from the main body of central cell 2, on opposite sides of the vertical centerline plane of the vehicle.

With reference to Figures 2 and 3, rear auxiliary

frame 4 is fixed to the distal ends of the two longitudinal members 5 by means of bolts or similar fastening systems, and, in the example shown, comprises two supporting beams 6 fixed to the rear end of central cell 2, on opposite sides of the vertical centerline plane of the vehicle, and each just beneath a corresponding longitudinal member 5 of central cell 2; and a number of horizontal transverse stiffening members 7 made of metal and connecting the two supporting beams 6.

Each of the two supporting beams 6 comprises two segments 6a and 6b arranged in the form of an L, and is fixed at a first end to central cell 2, close to the base of the corresponding longitudinal member 5, and at a second end to the head of corresponding longitudinal member 5, so that segment 6a of each of the two supporting beams 6 is positioned horizontally just beneath the corresponding longitudinal member 5.

More specifically, in the example shown, segments 6a of the two supporting beams 6 are located on opposite sides of the vertical centerline plane of the vehicle, and converge away from central cell 2; and segments 6b of the two supporting beams 6 slope outwards so as to define, with horizontal transverse stiffening members 7, a trapezoidal structure lying in a plane perpendicular to the vertical centerline plane of the vehicle.

It should be pointed out that the two supporting beams 6 are monolithic, may be made indifferently of

composite material or metal, such as aluminium, and are so formed as to comprise both the attachment points 8 for the rear vehicle suspensions on segments 6b, and the attachment points 9 for the engine supporting joints on segments 6a.

If made of metal, the two supporting beams 6 may be cast using cores of sand or similar filler material.

In addition, rear auxiliary frame 4 comprises two projecting supporting bars 10 extending parallel to and facing each other on opposite sides of the vertical centerline plane of the vehicle. Each of the two projecting bars 10 is preferably, though not necessarily, made of aluminium, and is fixed to the end of a corresponding supporting beam 6 to define an extension of a corresponding longitudinal member 5 of central cell 2.

With reference to Figures 1 and 3, front auxiliary frame 3 if fixed to the front end of central cell 2 by bolts or similar fastening systems, and, in the example shown, comprises two horizontal supporting beams 11 fixed to the front end of central cell 2, on opposite sides of the vertical centerline plane of the vehicle; and a number of horizontal transverse stiffening members 12 connecting the ends and the central portions of the two supporting beams 11.

In the example shown, each of the two supporting beams 11 comprises two box members 13 made of aluminium and fixed rigidly to each other by two connecting plates 14 welded to both ends of both box members 13, and which

are fixed to central cell 2 by bolts or similar fastening systems.

Preferably, though not necessarily, front auxiliary frame 3 has a number of supporting brackets 15 projecting from the two supporting beams 11 and from horizontal transverse stiffening members 12 to support, together with the two supporting beams 11 and with horizontal transverse stiffening members 12, the body panels and all the other front component parts of the vehicle, except for the front suspensions, the attachment points 16 of which are formed on the sides of central cell 2.

As stated, the rear suspension attachment points 8 are formed on the two supporting beams 6 of rear auxiliary frame 4.

Operation of body 1 is easily deducible from the foregoing description, with no further explanation required.

The advantages of body 1 as described and illustrated herein are obvious: in the event of medium- low impact, front auxiliary frame 3 and rear auxiliary frame 4 provide for absorbing mechanical stress before it reaches central cell 2 of composite material, thus preventing damage to the cell and drastically reducing repair cost.

Both front auxiliary frame 3 and rear auxiliary frame 4 can be cast in one piece using cores of sand or similar filler material, which provides for obtaining extremely rigid, lightweight structures.

Relieving the engine block of any structural function greatly simplifies the engine structure, thus greatly reducing weight.

Clearly, changes may be made to the vehicle body 1 as described and illustrated herein without, however, I departing from the scope of the present invention.