Wheel rim provided with a heat extractor device including a plurality of aerodynamic elements actuated by a single actuator element made of shape memory material

Abstract

A wheel rim (10) comprising a heat extractor device comprising: - a plurality of aerodynamic elements (6) distributed homogeneously along the circumference defined by the monolithic structure of the rim (10), wherein the aerodynamic elements (6) are mutually connected by a mechanical connection cable (12) substantially extended along said circumference - a single actuator element (7) made of shape memory material, reversibly deformable when a determined temperature is reached, from an initial rest position to an active deformed position, wherein said deformation causes a movement of the aerodynamic elements (6) from a neutral position to an aerodynamically active position adapted for directing a cooling airflow, - wherein said single actuator element (7) made of shape memory material is a wire of shape memory material, wherein the deformation of said wire from the initial rest position to the active deformed position realizes a contraction of the wire which causes the movement of a first aerodynamic element (6) of said plurality of aerodynamic elements (6) and puts in traction said mechanical connection cable (12) so as to actuate the movement of the other aerodynamic elements (6).

Description

[0001] “Wheel rim provided with a heat extractor device including a plurality of aerodynamic elements actuated by a single actuator element made of 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. 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 adapted for 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. 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, despite the aerodynamic benefits. In this context, there is therefore a need to develop an improved solution.

[0008] Object of the invention

[0009] It is an object of the present invention to provide a wheel rim that can satisfy said needs and overcome said drawbacks.

[0010] A further object is to satisfy said needs and overcome said drawbacks, through a solution that is overall simple and economical to implement. Summary of the invention

[0011] 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:

[0012] - a plurality of aerodynamic elements distributed homogeneously along the circumference defined by the monolithic structure, wherein the aerodynamic elements are mutually connected by a mechanical connection cable substantially extended along said circumference,

[0013] - a single actuator element made of shape memory material, reversibly deformable when a determined temperature is reached, from an initial rest position to an active deformed position, wherein said deformation from the initial rest position to the active deformed position causes a movement of the aerodynamic elements from a neutral position to an aerodynamical ly active position adapted for directing a cooling airflow,

[0014] - wherein said single actuator element made of shape memory material is a wire of shape memory material, wherein the deformation of said wire from the initial rest position to the active deformed position realizes a contraction of the wire which causes the movement of a first aerodynamic element of said plurality of aerodynamic elements and puts in traction said mechanical connection cable, actuating the movement of the other aerodynamic elements,

[0015] - in such a way that the deformation of a single actuator element made of shape memory material generates a uniform movement of all the aerodynamic elements.

[0016] Brief description of the figures

[0017] 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, in which:

[0018] - figure 1A is a perspective view of a wheel rim according to one embodiment, including a plurality of aerodynamic elements in a neutral position,

[0019] - figure 1 B is a further perspective view of the wheel rim of the previous figure, in which the aerodynamic elements are in an aerodynamical ly active position,

[0020] - figures 2A, 2B, are side views of the wheel rim illustrated in figures 1A, 1 B respectively,

[0021] - figure 3 is a schematic side view of a wheel rim according to one embodiment of the present invention, in which the aerodynamic elements are illustrated in a neutral position, and

[0022] - figure 4 is a view similar to that of the previous figure, in which the aerodynamic elements are illustrated in an aerodynamically active position.

[0023] Detailed description of the invention

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] The references illustrated herein are for convenience only and therefore do not delimit the extent of protection or the scope of the embodiments.

[0029] 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.

[0030] The monolithic structure comprises:

[0031] - a circumferential wall 10’ defining an external surface to receive the tire, and a corresponding internal surface,

[0032] - an external face 10” including said spokes intended to be visible from the outside of the vehicle, in the final assembled configuration.

[0033] The wheel assembly 1 includes a wheel support structure 2, commonly referred to as an upright or knuckle. Each support structure 2 can be connected to a vehicle chassis by one or more oscillating suspension elements 3.

[0034] The wheel assembly 1 further comprises a braking device 4 (illustrated schematically in figures 3, 4), for example a disc brake device, and at least one shock absorber assembly 5 connected along respective connecting portions to the support structure 2.

[0035] According to the present invention, the wheel rim 10 comprises a heat extractor device, including a plurality of aerodynamic elements 6 adapted for directing a cooling airflow, distributed homogeneously along the circumference defined by the monolithic structure of the wheel rim 10. The heat extractor device also comprises a single actuator element 7 made of shape memory material (illustrated in figures 3, 4), 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 deformed position causes the movement of the aerodynamic elements 6 from an aerodynamically neutral position to an aerodynamically 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 comprises a plurality of blades that can be oriented following the deformation of the actuator element 7 made of shape memory material. The deformation of the actuator element 7 occurs following the overheating of the wheel assembly 1 , during certain operating conditions, which cause the area of the rim where the actuator element 7 is mounted to reach certain temperatures.

[0036] 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.

[0037] In one or more embodiments, the actuator element 7 is made of Ni- Ti intermetallic material, also called Nitinol.

[0038] With reference to the attached drawings, in figures 1A, 2A, 3, wheel rim configurations with aerodynamic elements 6 in the initial neutral position are illustrated; in figures 1 B, 2B, 4, the same wheel rim is illustrated with aerodynamic elements 6 in an aerodynamically active position to generate a cooling airflow.

[0039] In the following, further features of a preferred embodiment of the present invention are described, illustrated in figures 3, 4.

[0040] As indicated above, the aerodynamic elements 6 are distributed homogeneously along the circumference defined by the monolithic structure of the wheel rim 10. The aerodynamic elements 6 provide a substantially annular formation of aerodynamic elements, extended along the circumferential wall 10', preferably at an internal circumferential terminal edge of the circumferential wall 10', opposite the external face 10". This position of the aerodynamic elements and the components that support them in position, is particularly strategic, as it is suitable for developing the necessary cooling on the wheel assembly, and at the same time not impacting the style of the wheel rim visible from the outside of the vehicle.

[0041] In one or more embodiments, the wheel rim 10 comprises a support ring 8 rigidly connected to the monolithic structure of the rim, on which the aerodynamic elements 6 are mounted. The support ring 8 extends along the circumferential wall 10', preferably along the internal circumferential terminal edge of the circumferential wall 10'. The support ring 8 is rigidly connected to the monolithic structure by means of a structural adhesive and / or by means of a plurality of fastening members and / or by means of mutually engaging snap means.

[0042] The aerodynamic elements 6 are respectively constrained to a portion of the support ring 8, by means of an articulation pin 9 adapted for facilitating an articulated movement of the aerodynamic elements 6 from the initial neutral position to the aerodynamically active position, and vice versa. Furthermore, each aerodynamic element 6 is provided with an elastic return element 11 adapted for returning the elements 6 to the neutral position when the actuator 7 passes from the active deformed position to the rest position.

[0043] According to a further feature, the aerodynamic elements 6 are mutually connected to each other by a mechanical connection cable 12 extending substantially along the circumference defined by the monolithic structure of the wheel rim 10. The connection cable 12 is supported in position by respective support pulleys 13 constrained to the monolithic structure of the wheel rim 10. According to a preferred embodiment, the pulleys 13 are connected to the support ring 8. Each aerodynamic element 6 is therefore connected to a respective portion of the mechanical connection cable 12. More specifically, observing figures 3, 4, it should be noted that the aerodynamic elements 6 are arranged in succession along the circumference of the wheel rim 10, creating a series of elements 6 starting from the first element 6 and ending with a last element 6. The distance between the elements 6, including that between the first and the last element 6 is substantially constant.

[0044] According to this arrangement of the elements 6, the connection cable 12 has a first end connected to the first element 6 and a second end connected to the last element 6. It will therefore be appreciated that between two adjacent elements 6 a section of cable 12 extends for mutual connection, and only the last element 6 and the first element 6 are not directly connected to each other by a section of cable 12.

[0045] As previously indicated, the heat extraction device comprises a single shape memory actuator element 7, 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 deformed position causes a movement of the aerodynamic elements 6 from an aerodynamically neutral position to an aerodynamically active position adapted for directing a cooling airflow towards one or more components of the wheel unit 1 . According to a further feature, said actuator element 7 is a wire of shape memory material with a substantially rectilinear extension. In other words, the actuator element 7 made of shape memory material is configured as a thin straight filament. When the wire is heated above its transition temperature, the material contracts back to its original shape. This contracting motion, which shortens the wire, is used to move the aerodynamic elements 6 from the neutral position to the aerodynamical ly active position.

[0046] The wire of shape memory material has a first end connected to a support element 14 preferably constrained to the support ring 8, or connected directly to the monolithic structure of the rim 10, or connected to the support ring 8. In a preferred embodiment, the first end of the wire is connected to a support element 14 positioned between the first and the last element 6 of the series of elements 6. The wire of shape memory material has a second end connected to the first of the aerodynamic elements 6 forming the circumferential series, together with the first end of the mechanical connection cable 12. Therefore, accordingly to said features of the elements 6, the cable 12 and the actuator element 7, it will be appreciated that as a consequence of reaching a certain temperature of the element 7, the wire shortens - passing from the rest position to the active deformed position -, causing the movement of the first aerodynamic element 6 and exerting a traction on the mechanical connection cable 12 in particular on the its first end. The traction of the cable 12 in turn causes a uniform movement of all the other aerodynamic elements 6.

[0047] In one or more embodiments, the deformation from the rest position to the active deformed position of the actuator element 7 occurs when a braking device 4 of the wheel unit 1 reaches a temperature comprised between 500 and 800°, which corresponds substantially to 50°-80° at a part of the wheel rim 10 on which the actuator element 7 is extended. When the actuator element 7 reaches such temperatures, mainly due to the emission of heat due to braking, it deforms reversibly from the rest position (extended wire) to the active position (shortened wire), causing a predetermined movement of the aerodynamic elements 6 to develop the cooling effect. The deformation of the actuator element 7 is reversible in that it returns to the initial rest position once the temperature returns below the values that caused the activation. Below the activation temperature, and therefore with the braking device at ordinary temperatures, the aerodynamic elements 6 are therefore not stressed and are in an aerodynamically neutral position, not creating the aerodynamic cooling flow. In other words, according to the invention, the wheel rim 10 comprises ventilation elements mounted on the monolithic structure of the rim, preferably inside the wheel, which convey fresh air towards the braking device 4 only when the braking device 4 is overheated. The movement of the aerodynamic elements 6 will be uniform thanks to the provision of a single actuator element 7 made of shape memory material.

[0048] It will therefore be appreciated that, according to the present invention, below certain temperatures reached by the wheel rim in the area where the actuator element is provided, the aerodynamic elements remain in a neutral position. It is precisely when localized temperatures are reached that can be burdensome for the components of the wheel assembly, that the aerodynamic elements automatically and uniformly orient themselves in the aerodynamically active position to advantageously develop the cooling effect.

[0049] In the embodiment in which the aerodynamic elements 6 are mounted at an internal face of the rim, along an internal terminal edge of the circumferential wall 10', the aerodynamic elements in the active position develop an aerodynamic flow conveyed from a central area of the vehicle under the vehicle floor, towards the wheel assembly 1 .

[0050] In one or more embodiments, in the aerodynamically active position, said aerodynamic elements 6 comprise at least one raised portion, with respect to a configuration substantially coplanar to a plane of the rim, creating a configuration substantially similar to the blades of a fan, to create the cooling airflow when the wheel rim rotates beyond a certain rotation speed.

[0051] In one or more embodiments, in the aerodynamically active position, said aerodynamic elements (6) rotate around the articulation pin, with respect to a configuration substantially flush with the circumferential wall 10', such that part of each element 6 results in a more internal position of the wheel, with respect to the circumferential wall 10'.

[0052] 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 the disc brake device, by arranging on the wheel rim a plurality of aerodynamic elements 6 of a reversible type, or which are active only when certain operating conditions are reached.

[0053] 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. A 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 including:- a plurality of aerodynamic elements (6) distributed homogeneously along the circumference defined by the monolithic structure, wherein the aerodynamic elements (6) are mutually connected by a mechanical connection cable (12) substantially extended along said circumference,- a single actuator element (7) made of shape memory material, reversibly deformable when a determined temperature is reached, from an initial rest position to an active deformed position, wherein said deformation from the initial rest position to the active deformed position causes a movement of the aerodynamic elements (6) from a neutral position to an aerodynamical ly active position adapted for directing a cooling airflow,- wherein said single actuator element (7) made of shape memory material is a wire of shape memory material, wherein the deformation of said wire from the initial rest position to the active deformed position realizes a contraction of the wire which causes the movement of a first aerodynamic element of said plurality of aerodynamic elements (6) and puts in traction said mechanical connection cable (12), actuating the movement of the other aerodynamic elements (6),- in such a way that the deformation of a single actuator element (7) made of shape memory material generates a uniform movement of all the aerodynamic elements (6).

2. The 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 elements (6), extended substantially homogeneously along the circumferential wall (10’).

3. The wheel rim (10) according to claim 1 , characterized in that each aerodynamic element (6) is constrained to the monolithic structure by means of an articulation pin (9) provided for enabling an articulated movement of the aerodynamic elements (6) from the initial neutral positionto the aerodynamically active position, and vice versa.

4. The wheel rim (10) according to claim 1 , characterized in that each aerodynamic element (6) is provided with an elastic return element (11 ) adapted for bringing back the aerodynamic element (6) to the neutral position, when the actuator element (7) passes from the active deformed position to the rest position.

5. The wheel rim (10) according to claim 2, characterized in that the aerodynamic elements (6) are arranged in succession creating a circumferential series of elements (6) starting from the first element (6) and ending with a last element (6), wherein the connection cable (12) comprises a first end connected to the first element (6) and a second end connected to the last element (6).

6. The wheel rim (10) according to claim 5, characterized in that the wire of shape memory material has a first end connected to a support element (14) or connected directly to the monolithic structure, and a second end connected to said first aerodynamic element (6).

7. The wheel rim (10) according to claim 1 , characterized in that it includes a support ring (8) rigidly connected to the monolithic structure, on which the aerodynamic elements (6) are mounted.

8. The wheel rim (10) according to claim 1 , characterized in that the elements (6) are arranged along an internal circumferential terminal edge of the circumferential wall (10’).

9. The wheel rim (10) according to claim 1 , characterized in that the deformation towards the active position occurs when a braking device (4) 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 actuator element (7) is located.

10. The 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 vehicle floor, towards the wheel rim (10).

11. The wheel assembly (1 ) comprising a braking device (4) and a wheel rim (10) having the features according to any of the previous claims, wherein said aerodynamic elements (6) convey a cooling airflow towards the braking device (4), only when the braking device (4) is overheated.

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