Wheel rim provided with a plurality of aerodynamic elements having a respective support structure made of a shape memory material

Abstract

Wheel rim (10) comprising a heat extractor device (5) having a plurality of aerodynamic elements (6) provided with a respective support structure (7) made of a shape memory material, wherein the support structure (7) is reversibly deformable when a determined temperature is reached, from a rest position to an active deformed position, wherein said deformation from the rest position to the active position causes a movement of the respective aerodynamic element (6) from a neutral position to an aerodynamical active position adapted for directing a cooling airflow.

Description

[0001] “Wheel rim provided with a plurality of aerodynamic elements having a respective support structure made of a shape memory material”

[0002] ****

[0003] TEXT OF THE DESCRIPTION

[0004] Field of the invention

[0005] The present invention relates to a wheel rim comprising a monolithic structure having a hollow annular seat for a tire, a hub and a plurality of spokes converging towards said hub.

[0006] Prior art

[0007] Wheel rims of the type indicated above are commonly used for motor vehicles produced for personal, commercial or even sports competition use.

[0008] According to a prior art, the wheel assemblies of the vehicle - including the wheel rim, a braking device such as a disc brake, and a wheel support structure - may also include one or more aerodynamic devices capable of directing a cooling airflow, in order to develop a cooling effect for one or more components of the wheel assembly. In all known solutions, such aerodynamic devices provide static solutions with a permanently defined shape to create said aerodynamic flow during vehicle dynamics.

[0009] However, these known solutions have some disadvantages, including the fact that aerodynamic devices can be particularly bulky or complicated to install, often making their implementation on the vehicle difficult. In this context, there is therefore a need to develop an improved solution.

[0010] Object of the invention

[0011] It is an object of the present invention to provide a wheel rim that can satisfy said needs and overcome said drawbacks.

[0012] A further object is to satisfy said needs and overcome said drawbacks, through a solution that is overall simple and economical to implement. of the invention

[0013] In order to achieve said aims, the invention has as its object a wheel rim comprising a monolithic structure having a hollow annular seat for a tire, a hub and a plurality of spokes converging towards said hub, characterized in that it also comprises a heat extractor device including a plurality of aerodynamic elements provided with a respective support structure made of a shape memory material, wherein the support structure is reversibly deformable when a determined temperature is reached, from a rest position to an active deformed position, wherein said deformation from the rest position to the active position causes a movement of the respective aerodynamic element from a neutral position to an aerodynamical active position adapted for directing a cooling airflow.

[0014] In a preferred embodiment, the monolithic structure comprises a circumferential wall defining an external surface for receiving the tire, a corresponding internal surface, and an external face including said spokes, wherein said aerodynamic elements provide an annular formation of aerodynamic blades, extended along the circumferential wall substantially continuously.

[0015] Brief description of the figures

[0016] Further features and advantages of the invention will be apparent from the following description with reference to the attached drawings, provided purely by way of non-limiting example, wherein:

[0017] - figure 1A is a perspective view of a wheel rim according to one embodiment, including a plurality of aerodynamic elements,

[0018] - figure 1 B is a further perspective view of the wheel rim of the previous figure with the aerodynamic elements illustrated in an aerodynamical active position,

[0019] - figures 2A, 2B are side views of the wheel rim of figures 1A, 1 B respectively,

[0020] - figure 3 is an enlarged scale view of an aerodynamic element provided with a support structure made of a shape memory material,

[0021] - figure 4 is an enlarged scale perspective view of the support structure illustrated in the previous figure,

[0022] - figure 5 is an enlarged scale view of a portion of the support structure illustrated in the previous figure,

[0023] - figure 6 is a perspective view of the aerodynamic elements provided with their respective support structure, with the aerodynamic elements in the aerodynamical active position, and

[0024] - figure 7 is an enlarged view of certain features illustrated in the preceding figure.

[0025] Detailed description of the invention

[0026] In the following description, various specific details are illustrated for the purpose of providing a thorough understanding of examples of one or more embodiments. The embodiments may be implemented without one or more of the specific details, or with other methods, components, materials, etc.

[0027] In other cases, known structures, materials, or operations are not shown or described in detail to avoid obscuring various aspects of the embodiments. Reference to “an / one embodiment” in this specification means that a particular configuration, structure, or feature described in connection with the embodiment is included in at least one embodiment.

[0028] Thus, phrases such as “in an / one embodiment,” which may appear in several places in this specification, do not necessarily refer to the same embodiment.

[0029] Furthermore, particular conformations, structures or features may be combined in a suitable manner in one or more embodiments and / or associated with the embodiments in a manner other than as illustrated herein, so that for example a feature exemplified herein in relation to one figure may be applied to one or more embodiments exemplified in a different figure.

[0030] The references illustrated herein are for convenience only and therefore do not delimit the extent of protection or the scope of the embodiments.

[0031] In the attached drawings, the reference number 1 indicates as a whole a motor vehicle wheel assembly including a wheel rim 10. The wheel rim 10 comprises a monolithic structure having a hollow annular seat for a tire and a plurality of spokes converging towards a hub which is part of the monolithic structure.

[0032] The monolithic structure comprises:

[0033] - a circumferential wall 10’ defining an external surface to receive the tire, and a corresponding internal surface,

[0034] - an external face 10” including said spokes intended to be visible from the outside of the vehicle, in the final assembled configuration.

[0035] The wheel assembly 1 comprises a wheel support structure 2, commonly referred to as an upright or knuckle. Each support structure 2 may be connected to a vehicle chassis by one or more oscillating suspension elements 3.

[0036] The wheel assembly 1 further comprises a braking device, for example a disc brake device, and at least one shock absorber assembly 4 connected along respective connecting portions to the support structure 2.

[0037] According to the present invention, the wheel rim 10 comprises a heat extractor device 5 including a plurality of aerodynamic elements 6 adapted for directing a cooling airflow. The aerodynamic elements 6 are respectively provided with a support structure 7 made of a shape memory material, wherein the support structure 7 is reversibly deformable when a determined temperature is reached, from a rest position to an active deformed position. The deformation of the support structure 7 from the rest position to the active deformed position causes the respective aerodynamic element 6 to move from an initial neutral position to an aerodynamical active position adapted for directing a cooling airflow towards one or more components of the wheel assembly 1. In other words, the heat extractor device 5 comprises a plurality of blades which can be oriented following the deformation of the respective support structure 7 made of a shape memory material. As previously stated, the deformation of the support structures 7 occurs as a result of the overheating of the wheel assembly 1 , during certain operating conditions, which cause the area of the wheel rim 10 in which the elements 6 are mounted to reach certain temperatures, and therefore also of the support structures 7.

[0038] The phrase “shape memory material” refers to a material that has the property of undergoing reversible deformations at specific temperatures. The material therefore has the ability to deform due to the reaching of a certain temperature, and return to its previous shape, once the temperature returns to a lower ranges than those that have activated the deformation.

[0039] In one or more embodiments, the support structures 7 are made of Ni-Ti intermetallic material, also called Nitinol. With reference to the attached drawings, figures 1 A and 2A illustrate an embodiment of a wheel rim 10 with aerodynamic elements 6 in the initial neutral position; in figures 1 B, 2B the same wheel rim 10 is illustrated with aerodynamic elements 6 in an aerodynamical active position to generate a cooling airflow.

[0040] In one or more embodiments, the aerodynamic elements 6, as illustrated in figures 1 A-2B, 6, 7, create an annular formation of aerodynamic blades, extended along the circumferential wall 10’ substantially continuously, preferably at an internal circumferential end edge of the circumferential wall 10’, opposite to said external face 10”. This position of the aerodynamic elements is particularly strategic, as it is suitable for developing the necessary cooling on the wheel assembly, and at the same time not impacting on the style of the wheel rim visible from the outside of the vehicle.

[0041] In one or more embodiments, the substantially continuous annular formation of aerodynamic blades is created by a plurality of aerodynamic elements 6 shaped substantially like a circumferential arc, preferably of identical size.

[0042] According to a preferred embodiment, the aerodynamic elements 6 are four elements of equal size, each defining substantially a quarter of the circumference of the monolithic structure of the wheel rim 10. Of course, other configurations can be provided, reducing or increasing the number of elements 6 forming the substantially continuous ring formation.

[0043] In one or more embodiments, two aerodynamic elements 6 arranged consecutively along the circumference of the monolithic structure are spaced from each other by at least 10 mm, in order to not provide mutual interference when the deformation is activated.

[0044] In one or more embodiments, in the initial neutral position, the aerodynamic elements 6 provided with the respective support structure 7 have two opposite main faces substantially parallel to the plane defined by the external face 10” of the wheel rim 10. The initial neutral position described above of the aerodynamic elements 6 also allows the overall aerodynamic drag coefficient of the vehicle to be reduced, thus increasing aerodynamic efficiency.

[0045] Overall, each aerodynamic element 6 includes an external end edge 6’ shaped like a circumferential arc and an internal end edge 6” also shaped like a circumferential arc. The two circumferential edges 6’, 6” are joined, along respective end portions of the element 6, by a respective side 6”’ of smaller size, substantially rectilinear. The aerodynamic elements 6 also have a reduced thickness, for example between 0.5 mm and 2 mm, so as to provide the necessary overall features of lightness and deformability.

[0046] In one or more embodiments, the aerodynamic elements 6 are made of metallic material, for example steel.

[0047] In the following of this description, further details are illustrated relating to the support structures 7 of the aerodynamic elements 6.

[0048] With reference to figures 3-7, each support structure 7 is formed substantially as a sector of a circumferential arc coupled to the aerodynamic element 6 and rigidly connected to the monolithic structure of the wheel rim 10. More specifically, for each element 6, the support structure 7 has a main curvilinear portion coupled to the external circumferential edge 6’ of the aerodynamic element 6, and a substantially rectilinear portion of smaller extension than the main curvilinear portion, coupled with one of the two smaller sides 6” of the aerodynamic element 6. The support structure 7 also has an overall thickness greater than that of the aerodynamic element 6, to achieve a particularly stable coupling. According to a further feature, illustrated in particular in figure 5, the support structure 7 has a recessed portion 7’ obtained to receive a corresponding part of aerodynamic element 6.

[0049] In light of what is described above and illustrated in figures 3-7, it will therefore be appreciated that in the final configuration of aerodynamic elements 6 coupled to the respective support structure 7, each aerodynamic element 6 has said two sides 6” facing respectively towards another aerodynamic element 7, in which a first side of said two sides 6” is rigidly connected to the substantially rectilinear portion of the support structure 7, and a second side of said two sides 6” is not coupled with the support structure 7. This configuration is necessary precisely to allow a movement of the aerodynamic element 6 from the neutral position to the aerodynamical active position, and vice versa, following the deformation of the support structure 7 caused by the variation in its temperature. In light of said configuration, said movement of the aerodynamic element 6 is represented by a lifting of a portion of the element 6 without joining with the support structure 7, which is predominant at a terminal part of the side 6” joined to the internal edge 6” (lifting with respect to the main plane achieved by the flat configuration of aerodynamic elements in the initial neutral position).

[0050] In one or more embodiments, each aerodynamic element 6 is rigidly connected to the respective support structure 6 by means of a structural adhesive.

[0051] In one or more embodiments, the support structures 6 are rigidly connected to the monolithic structure of the wheel rim 10, by means of a plurality of fastening members (for example fastening screws, rivets, fastening clips) and / or snap-on means with mutual engagement and / or by means of structural adhesive.

[0052] With reference to the embodiment illustrated in figures 6, 7, the wheel rim 10 comprises a plurality of fastening members 8, each having a main body substantially in the shape of a plate defining opposite end portions connected by interference to a respective support structure 7, thus creating the joining with two adjacent aerodynamic elements 6. The joining between the member 8 and the structure 7 occurs at the angle of the structure 7 defined by the main curvilinear portion and the substantially rectilinear portion of smaller extension. The width of the member 8 ensures a spacing between the substantially rectilinear portions of two support structures 7 that are adjacent in the final configuration assembled on the wheel rim 10. Once the coupling between the member 8 and two support structures 7 - carrying the respective element 6 - has been achieved, the fastening member 8 is fixed to the monolithic structure of the wheel rim 10. Preferably, this fixing is achieved by means of a connecting screw 9 coupled to two holes obtained respectively on the main body of the member 8 and on the monolithic structure of the wheel rim 10.

[0053] As previously indicated, the support structure 7 made of a shape memory material is reversibly deformable when a determined temperature is reached, from a rest position to an active deformed position, causing the movement of the respective aerodynamic element 6 to an aerodynamical active position capable of directing the cooling airflow towards one or more components of the wheel group 1 .

[0054] In one or more embodiments, said deformation occurs following the reaching of a temperature of the order of 500-800°C of the braking device of the wheel group 1 , which corresponds substantially to 50°C on the part of the wheel rim 10 on which the aerodynamic elements 6 are mounted. When the support structures 7 of the aerodynamic elements 6 reach such temperatures, mainly due to the emission of heat due to braking, they deform causing a predetermined movement of the elements 6 to develop the cooling effect. The deformation of the support structures 7 is reversible as they return to the initial neutral position once the temperature returns below the values that cause activation. Below the activation temperature, the aerodynamic elements 6 therefore do not create the aerodynamic cooling flow as they are in the initial neutral position.

[0055] In other words, according to the invention, the wheel rim 10 comprises ventilation elements directly mounted on the monolithic structure of the wheel rim, inside or outside the wheel, which convey fresh air towards the braking device only when it is overheated. The orientation of the aerodynamic elements 6 varies as a function of the temperature reached by the support structure 7, in a reversible manner.

[0056] It will therefore be appreciated that, according to the present invention, below certain temperatures reached by the wheel rim in the area where the support structures 7 are mounted, the aerodynamic elements 6 remain in a neutral position. It is precisely when localized temperatures are reached, that can be burdensome for the components of the wheel group, that the aerodynamic elements 6 automatically orient themselves in the aerodynamical active position to advantageously develop the cooling effect.

[0057] In one or more embodiments, in the aerodynamical active position (illustrated in figures 1 B, 2B, 3, 6), each aerodynamic element 6 has at least one raised portion, so as to create the desired cooling airflow, for example to cool a disc brake device associated with the wheel assembly. In other words, in the active position, said one or more aerodynamic elements 6 have respective raised portions, providing a configuration substantially similar to the blades of a fan when operating in rotation.

[0058] In the embodiment in which the aerodynamic elements 6 are mounted at an internal face of the wheel rim 10, along an inner end edge of the circumferential wall 10’, the aerodynamic elements 6 in the active position are partially raised towards an internal direction of the vehicle, away from the inner end edge of the circumferential wall 10’.

[0059] Preferably, the aerodynamic flow is conveyed from a central area of the vehicle under the floor, towards the wheel assembly 1 .

[0060] It will therefore be appreciated that the wheel rim according to the present invention allows one or more components of the wheel group to be cooled, such as for example a disc brake device, by arranging on the wheel rim one or more aerodynamic elements of the reversible type, or which are active only when certain operating conditions are reached.

[0061] Of course, notwithstanding the principle of the invention, the construction details and the embodiments may vary widely with respect to what is described and illustrated purely by way of example, without thereby departing from the scope of the present invention as defined in the attached claims.

Claims

CLAIMS1. Wheel rim (10) comprising a monolithic structure having a hollow annular seat for a tire, a hub and a plurality of spokes converging towards said hub, characterized in that it also comprises a heat extractor device (5) including a plurality of aerodynamic elements (6) provided with a respective support structure (7) made of a shape memory material, wherein the support structure (7) is reversibly deformable when a determined temperature is reached, from a rest position to an active deformed position, wherein said deformation from the rest position to the active position causes a movement of the respective aerodynamic element (6) from a neutral position to an aerodynamical active position adapted for directing a cooling airflow.

2. Wheel rim (10) according to claim 1 , characterized in that said monolithic structure comprises a circumferential wall (10’) defining an external surface for receiving the tire, a corresponding internal surface, and an external face (10”) including said spokes, wherein said aerodynamic elements (6) provide an annular formation of aerodynamic blades, extended along the circumferential wall (10’) substantially continuously.

3. Wheel rim (10) according to claim 2, characterized in that each aerodynamic element (6) includes an external end edge (6’) and an internal end edge (6”) shaped like a circumferential arc, mutually joined along respective ends by a pair of sides (6’”).

4. Wheel rim (10) according to claim 3, characterized in that each support structure (7) comprises a main curvilinear portion coupled to the external edge (6’) and an additional support portion coupled to one of the two sides (6’”).

5. Wheel rim (10) according to claim 1 , characterized in that two aerodynamic elements (6) arranged consecutively along the monolithic structure are spaced from each other by at least 10 mm, in order to not provide mutual interference when the deformation is activated.

6. Wheel rim (10) according to claim 1 , characterized in that the deformation towards the active position occurs when a braking device associated with the wheel rim (10) reaches a temperature comprised between 500 and 800°C, which corresponds substantially to 50-80°C at a part of the wheel rim (10) where the support structures (7) are mounted.

7. Wheel rim (10) according to claim 4, characterized in that in the active position, said aerodynamic elements (6) comprise at least one raised portion, providing a configuration substantially similar to the blades of a fan, in order to create the cooling airflow when the wheel rim (10) rotates above a determined rotation speed.

8. Wheel rim (10) according to claim 7, characterized in that said raised portion is predominant at a terminal part of the side (6”) joined to the internal edge (6”).

9. Wheel rim (10) according to claim 1 , characterized in that said aerodynamic elements (6) in the active position are configured to convey an airflow from a central area of the vehicle under the floor, towards the wheel rim (10).

10. Wheel rim (10) according to claim 2, characterized in that said annular formation of aerodynamic blades is extended substantially continuously in correspondence with an inner face of the wheel rim (10), along an inner end edge of the circumferential wall (10’).

11. Wheel rim (10) according to claim 1 , characterized in that the support structures (7) are rigidly connected to the monolithic structure of the wheel rim (10), by means of a plurality of fastening members (8).

12. Wheel assembly (1 ) comprising a braking device and a wheel rim (10) having the features according to any of the previous claims, wherein said one or more aerodynamic elements (6) convey a cooling airflow towards the braking device, only when the braking device is overheated.

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