Patent Application
20230382468
This patent application claims priority from Italian patent application no. 102022000010727 filed on May 24, 2022, the entire disclosure of which is incorporated herein by reference.
The invention relates to a composite body part for a road vehicle, to a relative road vehicle and to a relative method for the production of the body part.
In particular, the invention can advantageously, though not exclusively be applied to a roof panel for high-performance cars, to which explicit reference will be made in the description below without because of this losing in generality.
As it is known, a road vehicle usually comprises a shell substantially consisting of a chassis and a body. The body comprises the outermost parts of the road vehicle, which, therefore, are visible to users. These parts typically also include the roof or roof panel, namely the element, usually shaped like a slightly curved panel, which fulfils the function of protecting the passengers of the road vehicle both from atmospheric agents and in case of tilting of the car.
In the majority of cases, the roof is made of metal, in particular sheet metal, preferably aluminium, to limit the weight thereof. In these cases, the latter is fixed to the rest of the shell by means of fixing devices, such as threaded members or rivets.
On the contrary, in other known cases, the roof can be made of a material other than metal, such as glass or composite material, for example comprising carbon fibres. In these cases, the roof is directly glued to the rest of the shell by means of an adhesive, a sealant or a glue.
In recent years, especially in high-performance vehicles, manufacturers have tried to reduce vehicle weights as much as possible, hence using composite materials such as carbon fibres to manufacture a large part of the body. However, in order to maintain a suitable thickness without decreasing the performances of the vehicle in aerodynamic and sound-damping terms, modern roofs generally consist of several elements.
Generally speaking, modern roofs are obtained by joining, in particular by peripherally gluing, for example by means of polyurethane glues, an outer element (also known as aesthetic coat or outer skin, for example made of aluminium), which has an aesthetic and aerodynamic function and is visible from outside the vehicle, and an inner element (also known as skeleton or inner skin), which has a strictly structural function (as a matter of fact, it usually has a greater thickness than the outer component) as well as a performance-related function. The skeleton usually faces the inside of the passenger compartment and comprises, for example, a net-like structure and/or one or more cross members (usually made of metal, for the very purpose of improving the rigidity of the roof panel), which are configured to stiffen the roof.
Carbon fibre roofs alone usually offer scarce performances from the point of view of soundproofing.
For this reason, some modern aluminium roofs further comprise a sound-absorbing material interposed between one cross member and the other.
Owing to the above, in the Applicant's opinion, known art solutions, despite being functional, can be subjected to improvements.
In general, a further weight reduction is needed, as well as a simpler assembling and better performance in terms of sound damping, in addition to a better feel of the occupants of the passenger compartment of the road vehicle, thus increasing comfort and, hence, the driving pleasure.
Furthermore, known roof or roof panels made of carbon fibres often are dark and opaque and, therefore, the visibility of the road vehicle in very dark conditions has to be improved.
Patent US2021023830 discloses composite structures with a high bending stiffness and low heat release properties and methods for the production thereof.
Patent KR20200030772 discloses a sandwich structure comprising adjacent layers reinforced with continuous fibres and a central layer arranged between the adjacent layers, wherein the central layer is made of a porous material.
The object of the invention is to provide a roof panel for a road vehicle, a relative road vehicle and a relative roof panel production method, which are at least partially free from the drawbacks described above and, at the same time, are simple and economic to be manufactured and implemented.
According to the invention, there are provided a roof panel for a road vehicle, a relative road vehicle and a relative roof panel production method as claimed in the independent claims attached hereto and, preferably, in any one of the dependent claims directly or indirectly depending on the independent claims.
The appended claims describe preferred embodiments of the invention and form an integral part of the description.
Hereinafter, some embodiments of the invention will be described, in order to allow the latter to be better understood, by way of non-limiting example and with reference to the accompanying drawings, wherein:
In
In the figures, the same numbers and the same reference letters indicate the same elements or components with the same function.
For the purposes of the invention, the term “second” component does not imply the presence of a “first” component. As a matter of fact, these terms are only used as labels to improve clarity and should not be interpreted in a limiting manner.
The elements and features contained in the different preferred embodiments, drawings included, can be combined with one another or be isolated from one another, without for this reason going beyond the scope of protection of this patent application, as described hereinafter.
The road vehicle 1 has a front part 4 and a rear part according to its forward driving direction D, represented in
Furthermore, the road vehicle 1 comprises a chassis (of the known kind and, therefore, not shown in detail) and a shell 6 comprising a body 7 fixed to the chassis.
The body 7 comprises the outermost parts of the road vehicle 1, which, therefore, are visible from the outside of the vehicle 1.
The body 7 comprises at least one body part 8 as described hereinafter.
In particular, advantageously, though not necessarily, and as shown in the non-limiting embodiments of the accompanying figures, the body part 8 comprises/is a vehicle roof 9, which delimits the passenger compartment 3 at the top.
In other non-limiting cases, which are not shown herein, the body part 8 is different from the vehicle roof 9.
Hereinafter, the term “roof panel” should be considered as equivalent to “roof”.
Advantageously, though not necessarily, the body part 8, for example the roof 9, is fitted to the rest of the road vehicle 1 (for instance, to a structural skeleton) by means of peripheral gluing, e.g. by means of a (two-component) epoxy glue.
In particular, the body part 8 comprises an outer portion 10, which is configured to be arranged on the outer side of the road vehicle 1 and defines a first side 11 of the body part 8 (for example, of the roof 9, as shown in
Furthermore, the body part 8 comprises an inner portion 12, which is configured to be arranged, with respect to the outer portion 10, towards the passenger compartment 3 of the road vehicle 1 and defines a second side 13 of the body part 8 (for example, of the roof 9, as shown in
In other words, the first side is the one that is visible from the outside of the road vehicle 1, whereas the second side is the one that is visible from the inside of the passenger compartment 3 of the road vehicle 1.
As shown in the non-limiting embodiments of
In addition, advantageously, though not necessarily, the inner portion 12 also comprises one or more second composite material layers 15.
Advantageously, though not necessarily, the body part 8 further comprises an intermediate portion 16, which is arranged between the outer portion 10 and the inner portion 12. In particular, the intermediate portion 16 comprises, in turn, a layer 17 of sound-absorbing material M (preferably, in the form of a panel). The term “sound-absorbing” identifies a material M that is capable of absorbing sound waves, preventing part of them from bouncing on surfaces and reflecting themselves in the surrounding environment in the form of reverberation and echoes, thus improving the acoustic comfort of the vehicle 1 (in particular, of the passenger compartment 3). In quantitative terms, the term “sound-absorbing” indicates, in this disclosure, a material with a sound-absorption class ranging from A to D (calculated according to standard UNI EN ISO 11654:1998).
According to the non-limiting embodiments of
According to some non-limiting embodiments, like the ones shown in
According to some preferred non-limiting embodiments, the metal filaments 20 are made of copper or of an alloy thereof.
According to other non-limiting embodiments, the metal filaments 18 are made of gold, silver, platinum, tin, zinc or alloys thereof.
Advantageously, though not necessarily, and as shown in the non-limiting embodiment of
In particular, the fibres of the cloth are woven with a 0°/90° orientation between the fibres F making up the weft and the ones making up the warp of the cloth, namely in two different directions.
In some non-limiting cases, like the one shown in the figure, the metal filaments 18 are woven in one single direction, namely together with the fibres F making up the weft or the fibres making up the warp of the fibre cloth.
In other non-limiting cases, which are not shown herein, the metal filaments 18 are woven in both directions, namely together with the fibres F making up the weft and the fibres making up the warp of the fibre cloth.
Advantageously, though not necessarily, the metal filaments 18 have a thickness that is equal to or greater than the one of the carbon fibres F making up the cloth.
According to some preferred non-limiting embodiments, like the ones shown in
Preferably, in order to allow for a mounting procedure that is consistent with other types of roof, for example with a glass roof, the layer 17 of sound-absorbing material M has a thickness of 8 mm or less, preferably of 6 mm or less, in particular of circa 4 mm.
Advantageously, though not necessarily, and as shown in the non-limiting embodiments of
Advantageously, though not necessarily, and as shown in the non-limiting embodiments of
In some preferred non-limiting cases, the outer portion comprises (besides the outermost layer 19 with metal filaments 20, if present) an odd number of first composite material layers 14, in particular at least three, preferably five as shown in the non-limiting embodiments of
In other preferred non-limiting cases, which are not shown herein, the outer portion 10 comprises (the outermost layer 19 with metal filaments 20, if present, included) an odd number of first composite material layers 14, in particular at least three, preferably five as shown in the non-limiting embodiments of
Advantageously, though not in a limiting manner, according to the disclosure above, the outer portion 10 comprises (besides the outermost layer 19 with metal filaments 20, if present) at least two, preferably three (
In particular, the first grammage is smaller than the second grammage. In this way, it possible to obtain, by means of the second grammage, structural performances that would not be possible with the first grammage, whereas the first grammage meets the aesthetic requirements usually set for these composite materials. Therefore, advantageously, though not necessarily, the outer layers of the outer portion 10 have the first grammage.
Advantageously, the outer portion 10 comprises an odd number of first composite material layers 14, in particular the first grammage and the second grammage being alternated with one another. By so doing, the processing can be carried out on a symmetric material (with a symmetric section), which turned out to be particularly convenient during the outer portion 10 forming and lamination steps. Furthermore, the mutual adhesion between the different layers is enhanced during the forming and lamination steps.
Preferably, though not in a limiting manner, the first grammage ranges from 200 g/m2 to 300 g/m2, whereas the second grammage ranges from 300 g/m2 to 500 g/m2. These values allow for a sufficient flexibility in order to simplify the processing, but, at the same time, fulfil structural requirements (in terms of weight, but especially in terms of stiffness) of the outer portion 10. In particular, the number of odd first layers 14 and the grammages thereof can vary within the aforesaid ranges so as to obtain different mechanical features (such as weight and stiffness) depending on the vehicle model to be manufactured.
For the same symmetry- and aesthetic sense-related reasons, the inner portion 12 preferably comprises at least two second composite material layers having a grammage ranging from 200 g/m2 to 300 g/m2, namely with the first grammage of the outer layers of the outer portion 10.
According to a further aspect of the invention, there is provided a method for the production of the body part 8 (for example, of the roof 9 or roof panel) according to the disclosure made so far.
In particular, some of the main steps of the method are shown in the block diagram of
The method comprises a lamination step 23, during which said one or more composite material layers 14 of the outer portion 10 are shaped through lamination on a dedicated mould (of the known kind, for example with the shape of a roof 9, and therefore not described more in detail below).
Furthermore, the method comprises a first forming step 24 (to generically indicate steps 24′, 24″ of
In some non-limiting cases, the first step 24′ entails forming the outer portion 10 by means of a hot pressing station (of the known kind and, therefore, not described more in detail below, namely without an autoclave cycle) for hot pressing said one or more composite material layers 14. Hot pressing is preferable, though not in a limiting manner, in case the outermost layer 19 provided with metal filaments 20 is not present.
In other non-limiting cases, the first step 24″ entails forming the outer portion 10 by means of an autoclave cycle (of the known kind and, therefore, not described more in detail) for said one or more composite material layers 14. Autoclave forming of the pouter portion 10 is preferable, though not in a limiting manner, in case the outermost layer 19 provided with metal filaments 20 is present.
The method further comprises a coupling step 25, which is subsequent to the first lamination step 23 and to the forming step 24 and during which the layer 17 of sound-absorbing material M and said one or more second composite material layers 15 of the inner portion 12, which preferably are directly shaped on the previously formed inner portion 10, are coupled to the outer portion 10.
Finally, the method comprises a second forming step 26, which is subsequent to the coupling step 25 and during which the single multilayer body 18 is formed by placing the previously coupled outer portion 10, intermediate portion 16 and inner portion 12 in an autoclave. This step is preferably applied regardless of the first forming step 24 used.
Advantageously, though not necessarily, during the coupling step 25, the intermediate portion 16 is coupled to the inner portion 12 and to the outer portion 10 by means of the first adhesive film 21 and the second adhesive 22, respectively.
In some non-limiting cases, the method further comprises a coating step 27, during which the body part 8 is coated with an aesthetic or transparent film 28 or a paint.
Finally, the method subsequently comprises a mounting step 29, during which the body part 8 is mounted on the rest of the road vehicle 1, for example by means of sealing adhesives or other fixing elements.
In use, the single multilayer body 18 is easier to be mounted and has the same thickness as a glass roof, thus adjusting to all assembling procedures and improving, at the same time, the performances of the road vehicle 1 in terms of damping of the noise coming from the outside.
In particular, experimental tests have shown that, given the same total thickness, the body part 8, in particular the roof 9, reaches a weight that is 25% smaller than a corresponding roof made of aluminium currently used (provided with a skeleton and possible cross members).
Even though the invention described above specifically relates to a precise embodiment, it should not be considered as limited to said embodiment, for its scope of protection also includes all those variants, changes or simplifications covered by the appended claims, such as for example a different type of road vehicle (for instance, a front-drive vehicle), a different shape of the body part, a different composition of the materials, etcetera.
The body part, the vehicle and the method disclosed above have many advantages.
First of all, they lighten the structure of the road vehicle, thus improving the performances thereof with the same expressed power.
Furthermore, they simplify the installation of the body part, since it basically consists of the sole multilayer body.
A further advantage of the invention lies in the fact that, thanks to the presence of the sound-absorbing material M, which is integrated in the single multilayer body, the performances of the vehicle in terms of sound damping are significantly improved because of the fact that the panel of sound-absorbing material M is continuous, for example, along the entire extension of the roof, without interruptions due to the presence of skeleton nets or cross members.
In addition, in case the outer layer provided with metal filaments is present, the vehicle can more easily be identified even in extremely dark conditions, thus increasing the safety of the vehicle and of the passengers, besides making the road vehicle itself more likeable and luxurious.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102022000010727 | May 2022 | IT | national |
