12.10.2017

TITLE: "Cross-member assembly for a dashboard for vehicles"

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DESCRIPTION

Technical field

The present invention falls within the field of vehicular components, and relates to a cross-member assembly for a dashboard for vehicles. The cross-member is intended to support the driving dashboard of the vehicle, whereon other on-board elements are generally present, such as the steering wheel, push-buttons, indicators, warning lights, etc.

Background art

Dashboard cross-member assemblies are known in the automotive industry which comprise a support cross-member to be fastened to the body of the vehicle. The support cross-member has a load-bearing function, since it supports a number of components, such as: boxes, air outlets, air ducts, instrument panel, radio/navigation system, steering wheel with airbag, steering column, air conditioner, gear lever, etc.

The dashboard cross-member assemblies known in the art suffer from a few drawbacks.

One drawback is that the support cross-member is currently made by using materials characterized by a poor performance/production cost ratio.

For example, it is known to use steel for making the support cross-member, by using parts which are pressed, profiled, drawn, and then joined together by using fastening means such as welds, rivets, screws. Such a solution is economically satisfactory as far as the material in use is concerned, but it is contraindicated because of its heavy weight and because it requires a large investment for dies and assembly fixtures, as well as a long production cycle.

Another known alternative is aluminium, in which case the cross-member is made by using die-cast, profiled and pressed parts which are then joined together by fastening means. Aluminium is more expensive than steel, and essentially requires the same investment and production process as the steel solution.

A further alternative employed in the industry is magnesium, wherein the cross-member is made by using a single die-casting mould, with additional processing steps aimed at removing casting residues after the pressing operation. This is an expensive solution, particularly because of the magnesium-based raw material employed, which requires considerable investments and maintenance costs. A further drawback is that the technology required and the material itself are not easily accessible in all countries where motor vehicles are being manufactured.

An additional option in use in the industry is represented by composite materials (e.g. with carbon fibre reinforcement) . This is a solution for high-end, high- performance vehicles, typically for racing cars, the cost of which is particularly high, and is therefore not suited to large production volumes.

A further alternative resorted to in this field is the use of plastic materials for the support cross-member; however, such a solution cannot meet the latest performance requirements .

Summary of the invention

It is one object of the present invention to provide an improved cross-member assembly for a dashboard for vehicles which can overcome this and other drawbacks of the prior art, while at the same time being simple and economical to manufacture.

In particular, one of the technical problems that are solved by the present invention is to provide a cross- member assembly which can fulfil the requirements of automotive manufacturers in terms of mechanical performance, while at the same time combining light weight, fast production and low cost.

According to the present invention, this and other objects are achieved through a cross-member assembly for a dashboard for vehicles having the features set out in the appended independent claim.

It is to be understood that the appended claims are an integral part of the technical teachings provided in the following detailed description of the invention. In particular, the appended dependent claims define some preferred embodiments of the present invention, which include some optional technical features.

Brief description of the drawings

Further features and advantages of the present invention will become apparent from the following detailed description, which is supplied by way of non-limiting example with particular reference to the annexed drawings, wherein :

- Figure 1 is a perspective view, from the outside of a vehicle, of a dashboard cross-member assembly according to an embodiment of the present invention;

- Figure 2 is a front view, from the outside of a vehicle, of a dashboard cross-member assembly according to an embodiment of the present invention;

- Figure 3 is a perspective view of a particular support element ; - Figure 4 is a partial front view of the dashboard cross-member assembly according to one embodiment of the present invention;

- Figure 5 is a cross-sectional view of an elongated portion belonging to the support element;

- Figure 6 is an exploded perspective view, from the outside of a vehicle, of a dashboard cross-member assembly according to an embodiment of the present invention;

- Figure 7 is a front view, from the inside of a vehicle, of a dashboard cross-member assembly according to an embodiment of the present invention;

- Figure 8 is a perspective view of a dashboard including a cross-member assembly according to one embodiment of the present invention.

Detailed description of the invention

With particular reference to the annexed drawings, numeral 1 designates as a whole a cross-member assembly for a dashboard for vehicles, such as cars, to be fastened to the body or chassis of the vehicle; cross-member assembly 1 comprises :

- a main cross-member 2 moulded in thermoplastic material and configured for being fastened in a passenger compartment of the vehicle, main cross-member 2 extending along a main axis;

- a support element 4, preferably made of metallic material, fastened to the main cross-member for stiffening main cross-member 2 along the main axis and for supporting said main cross-member 2, support element 4 being configured for being fastened to the body or chassis.

The vehicle is preferably a motor vehicle, such as a car, a truck, or any other type of terrestrial vehicle. Main cross-member 2 is an elongated element arranged along a main axis thereof, which generally lies transversally to the direction of travel of the vehicle whereon the cross- member is mounted. For example, as is per se known, main cross-member 2 is adapted to extend from the right-hand side to the left-hand side of the passenger compartment of the vehicle, and to be fastened to the body. For example, with reference to Figure 2, the main axis of main cross- member 2 is horizontal.

In the example of Figure 7 a dashboard is shown, with which a plurality of on-board items are associated, including: air outlets 100, on-board indicators 102 (e.g. tachometer, speedometer, odometer, etc.), warning lights, multifunction levers 104, air conditioner controls 106, compartments 108, steering column 110, etc. The image does not show the steering wheel of the motor vehicle. As is apparent to a man skilled in the art, the dashboard may comprise further per se known on-board items, such as displays, satellite navigation systems, loudspeakers, sensors, pedals, etc. Merely by way of example, numerals 150, 152, 154, 156 designate some additional elements that may be useful to complete the dashboard, e.g. in order to give it the desired pleasant appearance, and to visually separate the passenger compartment from the rest of the vehicle. Thus, some aesthetically unpleasant elements such as wirings, body structure, components, fastening means and other structural/functional parts of the motor vehicle can be hidden from the user's sight. Such additional elements may also act as soundproofing insulators, e.g. for attenuating the noise coming from the engine.

Conveniently, the thermoplastic material comprises at least one of the following materials: polycarbonate; acrylonitrile-butadiene-styrene (ABS); polyamide; polypropylene. Other per se known thermoplastic materials may nevertheless be used for manufacturing main cross- member 2.

In accordance with a particular embodiment, the thermoplastic material of main cross-member 2 also comprises additional additives and/or fibres useful for further improving the mechanical performance (e.g. rigidity, elasticity, compression/tensile/flexural strength) of cross-member assembly 1 as a whole. In particular, the material used for making main cross-member 2 comprises: a matrix made of thermoplastic material; and a reinforcement comprising at least one of glass fibres and carbon fibres.

Main cross-member 2 is preferably made as one piece, conveniently by injection moulding. Support element 4 may conveniently be made of steel or aluminium, e.g. by die casting. Support element 4 may optionally be made from a metal alloy. As an alternative, support element 4 may be non-metallic .

Cross-member assembly 1 is one of the most important parts of the vehicle as regards safety in the event of a collision, and is therefore subjected to many verifications for assessing its mechanical parameters, such as, in particular, strength, deformability, resonance frequencies, ductility, fatigue strength. The present invention allows combining high mechanical performance with light weight, fast production and low cost. It is thus possible to obtain a cross-member assembly 1 which is lighter and less expensive, the required level of performance being equal. As a matter of fact, automotive manufacturers currently need to use increasingly lighter components in order to minimize the vehicle's final weight, so as to be able to reduce the vehicle's fuel consumption as much as possible, which is beneficial for both the user (lower cost) and the environment (less pollution) .

Preferably, brackets 8 made of thermoplastic material are co-moulded with support element 4, brackets 8 being also fastened to main cross-member 2. In particular, brackets 8 are fastened to main cross-member 2 by welding or screwing (e.g. by means of screws or bolts) . Therefore, brackets 8 are useful for securing support elements 4 to main cross-member 2. Alternatively, support element 4 may be fastened to main cross-member 2 via per se known fastening means.

Conveniently, main cross-member 2 comprises one or more fastening eyelets or holes to allow it to be fastened to the body of the vehicle by means of through elements, such as pins, rivets, bolts, screws, etc. In particular, the fastening eyelets can be located at the lateral ends of main cross-member 2.

Preferably, main cross-member 2 is co-moulded with metal brackets 9 that can be fastened to the body or chassis of the vehicle. In particular, such metal brackets 9 are located at the lateral ends of main cross-member 2. Metal brackets 9 conveniently comprise holes or eyelets for being fastened to the body of the vehicle.

Support element 4 has an elongated portion 6 with an engagement surface adapted to mechanically engage with a complementary engagement surface of main cross-member 2, in order to constrain support element 4 to main cross-member 2. In particular, said engagement portions are configured for preventing any mutual rotation and any mutual sliding in at least one direction between main cross-member 2 and support element 4 (e.g. relative vertical movement is prevented) . In particular, it is possible to prevent any mutual sliding between main cross-member 2 and support element 4 in a plane perpendicular to said main axis. In this example, on the outer surface of elongated portion 6 there are protrusions/recesses to be engaged with complementary recesses/protrusions on main cross-member 2. In other words, the engagement portions of elongated portion 6 and of main cross-member 2 create a male/female coupling, e.g. by means of protrusions/recesses.

Preferably, also plastic brackets 8 co-moulded with support element 4 engage mechanically with the engagement surface of elongated portion 6 by means of complementary engagement surfaces, such as recesses/protrusions.

Preferably, the protrusions/recesses are arranged along most of the length of elongated portion 6.

In the illustrated example, the protrusions/recesses on elongated portion 6 are fins 10 adapted to mechanically engage with complementary slots on the engagement portion of main cross-member 2.

In particular, elongated portion 6 is a straight beam, preferably arranged in a position substantially parallel to the main axis of main cross-member 2. With reference to the illustrated example, the beam is a tubular unit, preferably having a circular shape. On the outer surface of the beam there are protrusions/recesses that preferably cover most of the length of said straight beam. In particular, the protrusions/recesses on the beam are fins 10, which preferably cover most of the length of said beam.

With reference to the particular variant illustrated herein, the engagement portions (in this example, the protrusions/recesses) allow the beam and main cross-member 2 to mutually slide along the main axis. Therefore, at the assembly stage, the beam (belonging to elongated portion 6) can be fitted into main cross-member 2 for the purpose of mounting support element 4 to main cross-member 2.

In particular, brackets 8 are fixed to elongated portion 6.

In its lower part, support element 4 comprises a fastening portion adapted to be constrained to the body or chassis of the vehicle, e.g. in a substantially central region of the passenger compartment, such as the gear lever area. In particular, support element 4 is intended to be fastened to the body or chassis only in the substantially central region of the passenger compartment. The fastening portion is located in a substantially central position of cross-member assembly 1. In the illustrated example, the fastening portion comprises a downward arm 12 constrained to elongated portion 6, in particular to one end thereof, e.g. by welding. Downward arm 12, which may be arranged either vertically or obliquely, connects elongated portion 6 to the body or chassis. In accordance with a particular variant, downward arm 12 is a hollow boxed element, e.g. comprising two half-bodies welded together.

In the particular variant shown herein, the lower part of downward arm 12 is associated, e.g. by means of bolts, with a metal flange 14 adapted to be fastened to the body or chassis. For example, elongated portion 6 and downward arm 12 are made of aluminium, and metal flange 14 is made of steel.

Preferably, support element 4 is shorter than main cross-member 2 with reference to the main axis, and is constrained to main cross-member 2 along a tract that is shorter than main cross-member 2. Preferably, support element 4 is fastened to main cross-member 2 in a region intended for receiving the steering gear (e.g. steering wheel and steering column) . Preferably, elongated portion 6, in particular the beam, is shorter than main cross- member 2; for example, the length of elongated portion 6 is shorter than or equal to half the length of main cross- member 2. For example, support element 4 includes a downward arm that connects elongated portion 6 to said fastening portion.

In accordance with a particular variant of the invention, main cross-member 2 comprises a second fastening portion to be constrained to the body or chassis of the vehicle in a substantially central region of the passenger compartment, such as the gear lever area. In particular, the second fastening portion includes a first downward beam 16 adapted to be constrained to the body or chassis. In this example there is a second downward beam 18 having a shape suitable for receiving, at least partially, downward arm 12 of support element 4. For example, the second downward beam 18 has a cavity that houses the outer profile of downward arm 12. The second downward beam 18 is connected to the first downward beam 16 through a horizontal element 20. The first and second downward beams 16, 18 and horizontal element 20, together with the upper part of main cross-member 2, form a frame that defines a through cavity. Said through cavity can accommodate per se known elements, such as air outlets, push-button panel, compartment, radio, etc. Preferably, elements 16, 18, 20 are made as one piece with main cross-member 2.

In the particular variant shown herein, the lower part of the first downward beam 16 is associated, e.g. by means of bolts, with a second metal flange 22, e.g. made of steel, adapted to be fastened to the body or chassis. Optionally, a tapered element 24, e.g. having a conical shape, is fastened to main cross-member 2, conveniently by welding or by means of bolts. Elongated portion 6 is interposed between main cross-member 2 and tapered element 24. Tapered element 24 is moulded in thermoplastic material. Tapered element 24 extends transversally to the main axis of main cross-member 2; it 24 also has an engagement portion for mechanically engaging with the engagement portion of elongated portion 6.

In particular, at least a protruding element 26 (in this example, two) is associated with elongated portion 6, arranged transversally with respect to elongated element 6. Said protruding element 26 is configured for fitting into a corresponding seat 28 formed in main cross-member 2, for the purpose of improving the mechanical engagement between support element 4 and main cross-member 2. Said protruding element 26 preferably has an elongated shape, in particular a tapered shape; in this example, it 26 has a wedge-like shape .

Main cross-member 2 is prearranged for being mounted to the body, or chassis, of the vehicle. For example, main cross-member 2 made of thermoplastic material may be fastened to the body by means of screws, bolts, rivets, joints, etc.

Main cross-member 2 illustrated herein advantageously has a plurality of ribs that enhance the rigidity and reduce the weight thereof.

Of course, without prejudice to the principle of the invention, the forms of embodiment and the implementation details may be extensively varied from those described and illustrated herein by way of non-limiting example, without however departing from the scope of the invention as set out in the appended claims.

Barzano & Zanardo Milano S.p.A.

/GV/LT