WO2018224754A1

WO2018224754A1 - Integral wheel

Info

Publication number: WO2018224754A1
Application number: PCT/FR2018/051264
Authority: WO
Inventors: Mostapha EL-OULHANI; José Merino Lopez; Olivier Muhlhoff; Hélène JAQUET; Margarita Dorato; Masayohi NOMURA; Tomohiro Seii
Original assignee: Compagnie Generale Des Etablissements Michelin
Priority date: 2017-06-09
Filing date: 2018-06-01
Publication date: 2018-12-13
Also published as: FR3067286A1

Abstract

A load-bearing structure (1) suitable for being mounted on a motor vehicle, comprising: - a tread (2) comprising a rolling surface (3) suitable for being in contact with a roadway; - a wheel comprising: - a wheel centre (4), through which the axis of rotation C-C of the wheel passes; - a wheel periphery suitable for carrying the tread (2), - the wheel being formed from a same material; and, - the wheel having a rigidity gradient from the centre of the wheel towards the periphery of said wheel, the rigidity being greater at the centre of said wheel.

Description

INTEGRAL WHEEL

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a wheeled carrier structure for a vehicle comprising a center, a periphery and a tread.

STATE OF THE PRIOR ART

The majority of the vehicle wheels used today are constituted by a set in which there is a rim, sheet or alloy more noble, on which is mounted a tire, hence the common name of " assembled together. For more than 100 years, this solution has equipped millions of vehicles, and is the subject of incessant improvements. Document FR 418002 describes an example of one of the first mounted assemblies using tires with reinforced beads. The reasons why mounted assemblies are so widely used are numerous. Compared with previous solutions with hard wheels, the inflated part of the wheel serves as a shock absorber, greatly increasing the comfort of the passengers of the vehicle. The tire is also provided with a tread whose characteristics are provided according to the use and / or the type of vehicle. This type of solution, however, has certain disadvantages related to the very nature of the concept, such as the risk of punctures. Today, many tire manufacturers are working on advanced products to reduce this risk. To date, no universal solution is truly available.

Today, given the very large number of types of vehicles of all kinds, the tires are produced in an equally large number of dimensions, to optimize the performance of the tire / vehicle torque. The rims also exist in a very large number of dimensions. This is not without presenting innumerable difficulties at the level of the production lines and logistic chains making it possible to ensure the storage and supplying so many product families. There is therefore a need for a simpler product, both in terms of manufacturing and for distribution. [0004] There are other types of wheels, provided with non-inflated tires.

[0005] Document FR 241 1721 describes, for example, rubber solid elastic tires for vehicle wheels such as industrial trucks and other similar vehicles. These solid tires are used in some applications, preferably for tires, because of their insensitivity to punctures and their high radial rigidity ensuring a low sag under load. But because of their massive structure and poor thermal conductivity of rubber, they are prone to overheat, by hysteresis phenomenon when subjected to severe conditions of load and speed. This internal heating can reach a value such that it reduces the strength properties of the rubber and greatly accelerates the degradation.

In another example, the document EP 271 1 199 describes a solid rigid wheel without inflation used in mobile irrigation systems. The wheel is composed of a central part surrounded by a thin rubber band, without inflation. This type of wheel is well adapted for this very particular use where the movements are limited, at low speed, and where the criterion of comfort is irrelevant. In another example, GB 2183565 discloses a wheel with a tire without inflation whose cavity is filled by an insert consisting of several layers of expanded plastic. This solution may be suitable for certain types of specific uses, but has many disadvantages, including the risk of heating due to friction between the insert and the tire.

US 2004012246 discloses a wheel consisting of a hub, lamellar spokes and a flexible strapping on the outside of the wheel where the tread is. WO 2015175003 discloses a wheel consisting of a hub and radially arranged slats to support the tread.

These latter solutions can eradicate the risk of puncture. The wheels, however, are complex to produce and remain for the moment confined to well-targeted uses.

There is therefore a need for an improved wheel, to eliminate the risk of puncture, but without sacrificing the comfort and dynamic qualities of the tire.

There is also a need for a wheel to achieve additional weight gains, while providing better continuity with the vehicle to which it is attached.

Furthermore, WO2013086577 discloses a device and a method of retreading tires, comprising a heating means, for heating the worn surface of the tire on which the tread must be applied, and a 3D printer adapted for applying one or more layers of thermoplastic elastomer to the heated surface to form a new tread. The device and method described relate to the field of conventional tires. The heating means and the heating steps of the worn surface make the process and the device complex to implement and energy-consuming.

To overcome these disadvantages, the invention provides different technical means.

SUMMARY OF THE INVENTION

First, a first object of the invention is to provide a vehicle wheel whose puncture risks are removed. "

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A second object of the invention is to provide a vehicle wheel to minimize and / or simplify the maintenance and maintenance operations. Yet another object of the invention is to provide a vehicle wheel of reduced mass.

Another objective of the invention is to provide a vehicle wheel for implementing new functions.

To do this, the invention provides a carrier structure (rolling) adapted to be mounted on a motor vehicle, said carrier structure comprising:

a bearing structure center, through which the axis of rotation C-C passes;

a bearing structure periphery adapted to carry a tread;

the supporting structure being formed in the same material or mixture or alloy of materials; and

the bearing structure having a stiffness gradient of the center of the bearing structure towards the periphery of said bearing structure, the rigidity being greater in the center of said bearing structure.

Such an arrangement allows for a lightweight mounted assembly and without risk of puncture. The assembled assembly is particularly suitable for the manufacture by addition of material. The tread is advantageously "rechargeable", that is to say that it can be reconstituted after total or partial wear, reference by addition of material.

A mixture or alloy of materials may for example consist of a hard material and a soft material, the proportions varying between the center (100% hard) and the periphery (100% soft) through 50/50 between these two areas. According to an advantageous embodiment, the material of said support structure comprises a plurality of recesses. The recesses allow to lighten the structure and allow to constitute a set with good bending characteristics.

According to yet another advantageous embodiment, all or part of said plurality of recesses are in communication with each other. The communicating hollows make it possible to cool the structure during the course of running thanks to a possible air circulation between the wheel and its environment. This cooling increases the endurance performance of the mounted assembly, especially at high speeds. The architecture comprising a plurality of intercommunicating cavities also makes it possible to provide a mode of evacuation of the water from the tread towards the inside of the wheel and then towards the lateral sides of the mounted assembly. This improves wet grip performance and lowers the hydroplaning speed threshold, improving safety.

Advantageously, the hollow rate increases from the center of the carrier structure to its periphery. Either the size of the hollows increases from the center to the periphery, or the number of hollows increases from the center to the periphery.

For example, the hollow level at the periphery of the carrier structure may be greater than 50%, and preferably greater than 75%. According to an advantageous embodiment, at least one material has a shore hardness A between 20 and 95, and preferably between 40 and 75 This promotes the establishment of the rigidity gradient of the carrier structure.

The material used may be polyurethane or an elastomer mixture. _r

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Advantageously, in the central zone, the Young's modulus is greater than 5 GPa, and preferably greater than 20 GPa.

Also advantageously, all or part of the material is recycled, and / or recyclable and / or is from bio-sourced material, for example from natural rubber, plants, etc..

Advantageously, the carrier structure (in particular the intermediate zone and the peripheral zone) is made in the form of a three-dimensional structure (or lattice) comprising a plurality of beams. Alternatively, the structure is made by layers or layers of honeycomb.

The beams are preferably interconnected by beam joints. Alternatively, walls connect together at least a portion of the beams.

Advantageously, the beams are oriented to form a Voronoi structure, with a Delaunay triangulation.

Advantageously, the carrier structure comprises a hub for mounting said wheel on the vehicle, preferably by the inside of the vehicle. To achieve this mounting, the hub may comprise for example at least one reinforcing zone, for the realization of fastening means (for example a bore) for fixing the hub to the motor vehicle. According to yet another advantageous embodiment, the wheel comprises at least one housing adapted to receive a light block comprising a light source. The light block advantageously comprises a brightness detector adapted to control the light source according to the ambient brightness. The dimples allow the ambient brightness to be detected by the detector. The housing is visible only from the inside of the wheel, making the effect created by the light even more significant for the user, without damaging the design of the wheel and maintaining its enhancing appearance. According to an advantageous embodiment, the carrier structure comprises a plurality of sticks extending radially between the center and the periphery of said carrier structure. This lighten the load-bearing structure and improve its cooling by the ambient air.

According to an advantageous embodiment, the carrier structure further comprises a tread having a running surface adapted to be in contact with a roadway.

The tread is preferably integrated by additive manufacturing, using the carrier structure as a support.

Also advantageously, the tread comprises a plurality of channels extending from the surface of the tread towards the inside of the carrier structure, said channels being in communication with all or part of the troughs of said tread. wheel.

Advantageously, a peripheral reinforcing structure is disposed between the surface of the tread and the carrier structure or in the carrier structure, close to the tread. This peripheral reinforcement also makes it possible to stiffen the supporting structure.

The carrier structure is advantageously carried out by additive manufacturing. This makes it possible to produce an integral wheel in which the tread is structurally integrated with the peripheral zone. This also allows for wheel geometries with a large number of beams that would not be feasible or demoldable with traditional manufacturing processes such as rigid molds.

The carrier structure is advantageously not inflated, thereby eliminating the risk of puncture. There is therefore no air under pressure: the air contained in the supporting structure is at ambient pressure. According to various embodiments, the hub is in the same material as the rest of the wheel or the hub is a part attached to the wheel.

The invention also provides a method of manufacturing a carrier structure adapted to be mounted on a motor vehicle, said carrier structure comprising:

a bearing structure center, through which the axis of rotation C-C passes;

a bearing structure periphery adapted to carry a tread,

the supporting structure is formed of the same material or mixture or alloy of materials and has a stiffness gradient from the center to the periphery, the rigidity being greater in the center of said supporting structure;

carrier structure being manufactured in whole or in part by additive manufacturing.

According to an advantageous embodiment, the carrier structure is manufactured from a hub. The hub can be independent, and the supporting structure is manufactured on the hub.

According to an advantageous embodiment, a tread is manufactured by additive manufacturing on the carrier structure. The tread is either manufactured in the same manufacturing phase as the carrier structure, or from a previously manufactured carrier structure.

DESCRIPTION OF THE FIGURES

All details of implementation are given in the following description, supplemented by Figures 1 to 7, presented for purposes of non-limiting examples only, and in which: Figures 1a and 1b are cross-sections illustrating two embodiments of integral wheel according to the invention; FIGS. 2a, 2b, and 3 are enlarged views of portions of the integral wheels of FIGS. 1a and 1b, ie the zones of the top of FIGS. 1a and 1b in FIGS. 2a and 2b, and the central zone for the FIG. 3;

Figure 4 illustrates a tread portion of the integral wheel of Figure 1a;

Figures 5 and 6 illustrate the integral wheel of Figure 1 seen from the outer side in Figure 5 and the inner side in Figure 6;

Figure 7 illustrates an enlarged view of the three-dimensional structure of the integral wheel.

DETAILED DESCRIPTION OF THE INVENTION

DEFINITIONS By "elastomer material or mixture is meant a diene elastomer, that is to say in known manner an elastomer derived from at least in part (ie homopolymer or copolymer) of monomers dienes (monomers bearing two carbon-carbon double bonds, conjugated or otherwise). "Hollow" or "hole" means an available space or a void area or absence of material, the perimeter or contour of which is defined by the surrounding material (for example the beams and / or joints of beams). a lattice structure. By "tread" means the portion of the mounted assembly arranged peripherally and intended to be in contact with the ground. The tread excludes any circumferential cables arranged at the top. This type of arrangement makes it possible to reconstruct the tread by adding material.

By "additive manufacturing" is meant a manufacturing process by addition of material, better known as 3D printing. This process of _{Λ n}

Manufacturing transforms a 3D model into a physical object, by assembling one or more successive layers of one or more material (s).

Figures 1a and 1b illustrate examples of supporting structures 1 or integral wheels according to the invention. The carrying structure comprises a tread 2 providing a tread surface 3 adapted to interface with the ground. The carrier structure center 4, defined by an axis CC, serves as a rotation axis. A fixing hub 5 is arranged in the central zone of the supporting structure. This hub 5 makes it possible to fix the carrier structure to a vehicle. In the example illustrated in FIG. 3, the hub 5 defines a hollow cylinder 16 for fixing a bearing structure in which a wheel axle can be accommodated. The wall of the cylinder 16 accommodates a plurality of hub reinforcements 14, designed to accommodate wheel attachment means, such as fixing screws. The reinforcements 14 are preferably made of a material filling the entire volume without forming a depression. The material of the reinforcements 14 is advantageously the same as that of the hub. Reinforcements made of metal or composite materials can also be used. Still in the embodiment shown in Figure 3, at least one housing 15 is provided in the hub. This housing allows to position a light block (not shown) for illuminating all or part of the carrier structure, the hub 5 to the periphery. The light block preferably comprises a battery or a battery and a plurality of low-energy bulbs, for example an led or oled bulb. Alternatively, the hub comprises a plurality of housings 15 for as many light blocks of one or more colors, operating alternately or simultaneously. The specific structure of the carrier structure, with a plurality of intercommunicating cavities 9 (as described in more detail in the following), allows a diffusion of light throughout the carrier structure. In addition to various aesthetic effects, the illuminated load-bearing structures can enhance the illumination of the vehicle, for example with side lights and / or signals indicating changes of direction. Each light block comprises an antenna and a control circuit of lighting, preferably in connection with a central housing provided at the vehicle.

As shown in the section of the wheel of Figure 1, between the hub 5 and the tread 3, there is first an intermediate zone 6 of the carrier structure, then a peripheral zone 7 of the carrier structure radially outside the intermediate zone 6 of the supporting structure. The peripheral zone 7 extends over the entire circumference of the carrier structure and carries the tread 2, structurally integrated with the peripheral zone 7 through a tread-bearing surface.

Figures 1a, 1b and 2a and 2b show two embodiments of the integral wheel. In the example of Figure 2a, the outer contour of the peripheral zone forms the tread bearing surface. In the example of Figure 2b, a circumferential crown reinforcement 19 is provided between the tread and the peripheral zone. This crown reinforcement stiffens the integral wheel and forms a peripheral protection. It may optionally comprise elements of circumferential reinforcements such as textile, metal or hybrid son or cable.

In the example illustrated in Figures 5 and 6, the intermediate area 6 of the carrier structure comprises a plurality of sticks 13 (or stays) connecting the hub 5 to the peripheral region 7 of the carrier structure. Between three and nine sticks can be provided. Openings or windows 17 are defined between the sticks 13. In the example illustrated, the openings are of ovoid profile. Other opening profiles may be provided according to various alternative embodiments not shown. The section of the beams constituting the sticks is provided for example between 3 and 10 mm. The section of the beams is preferably circular. It is preferably variable between the middle of the beam and its ends, the smallest section being positioned in the middle. Preferably, the beams have a simple radius of curvature or S, the radius is greater than the half-length of the beams. They are preferentially straight in the low vacuum parts. ""

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The beams join together forming nodes at their ends (joints 12 of beams).

As shown in the portion enlargements of the peripheral zone of FIGS. 2 and 7, the mounted assembly, and more particularly the intermediate zone 6 and the peripheral zone 7, generally consist of a three-dimensional network or structure 10 of beams 1 1 (or lattice), the beams being interconnected by joints 12 of beams, and oriented to form a Voronoi structure, with a Delaunay triangulation. The spaces between the beams 1 1 form hollows 9. Such a structure, by minimizing the probability of generating elongated triangles, makes it possible to produce a load bearing structure that is sufficiently strong and durable to carry the weight of the vehicle and to withstand the stresses associated with rolling. vehicle. A judicious choice of the material of the beams 1 1 makes it possible to create flexible and resilient beams, making it possible to provide an area of contact with the ground in a manner similar to the contact area produced by the deformation of a tire for a conventional wheel.

In known manner, it is shown that the edges of the Voronoi cells correspond to portions of Delaunay triangles mediators. Similarly, cell vertices are the centers of circumscribed circles of Delaunay triangles. In other words, two vertices ends of an edge of a Voronoi cell - out of bounds - are the circumscribed circle centers of two adjacent Delaunay triangles. Such a structure makes it possible to minimize the surfaces of the beams, and therefore the mass of the supporting structure. Moreover, a structure with "hollow" 9 or three-dimensional cells is obtained, which has many advantages in use, such as a significant reduction of the supporting structure or the possibility of promoting the evacuation of water by the inside the supporting structure. Figure 4, showing an enlarged area of rolling surface, shows the channels 8 which communicate with the tread, allowing the water to freely enter the structure of the integral wheel, for evacuation from the sides. "

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The three-dimensional structure 10 also allows the possibility of creating a carrier structure lighting, as previously described.

The patterns formed by the three-dimensional structure 10 of beams 1 1 may be repetitive or not. Non-repeating units are advantageously used, in particular to reduce the sources of vibrations (in particular the resonances) and the noise level. The average trough rate of the three-dimensional structure is greater than 50% and preferably greater than 75%. According to a preferred embodiment, the hollowing rate increases by going radially outwardly in the three-dimensional structure.

The material used to create the three-dimensional structure is preferably polyurethane or rubber material. The shore A hardness level of the material is advantageously between 20 and 65. The tread is preferably made of rubber material.

Figure 4 allows to clearly view the running surface 3 provided by the tread 2, clearly visible in Figures 2, 5 and 6. As illustrated, the tread is directly integrated with the peripheral zone 7. through a tread-bearing surface, making it possible to constitute a unitary or integral wheel. In contrast to the three-dimensional structure of the radially inner regions of the wheel, the tread provides a plurality of surface sculptures 18. The tread is embedded in the radially outer zone of the peripheral zone 7. The treads 18 extend radially outwardly beyond the peripheral zone to create the tread surface. These sculptures are advantageously thin, for example with a height of 2 to 5 mm. Figure 4 allows to clearly visualize an embodiment having radial channels 8 tread. These channels are areas where there is no sculpture 18 or three-dimensional structure 10, allowing communication between the inside and the outside of the supporting structure. This feature further allows the water present under the tread to enter the peripheral area 7 to then escape from the sides ""

14 of the integral wheel. The wet running properties are optimal and the risk of aquaplaning is greatly reduced.

The integral wheel according to the invention does not include an inflatable portion, the risk of puncture is completely removed.

The carrier structure is advantageously carried out using a manufacturing method by adding material. The at least one material of said support structure is a composite material (based on plastic, thermoplastic) Ex: based on polyurethane, PET, polyamide, epoxy resin, carbon fiber, natural fiber, fiberglass or elastomer mixture.

Reference numbers used in figures Carrier structure / mounted assembly / integral wheel

Tread

Rolling surface

Wheel Center

Hub

Intermediate wheel area

Peripheral area

Tread channels

Hollow three-dimensional structure with beams

beams

Beam joints

Stick / Shroud

Hub reinforcement

Light block housing

Wheel fixing cylinder

Opening / Window

Sculpture

Summit reinforcement

Claims

1. Carrier structure (1) adapted to be mounted on a motor vehicle, said carrier structure comprising:

a carrier structure center (4) through which the axis of rotation C-C passes;

a bearing structure periphery adapted to carry a tread (2), characterized in that:

the supporting structure is formed of the same material or mixture or alloy of materials;

- The carrier structure has a stiffness gradient of the center of the bearing structure to the periphery of said support structure, the rigidity being greater in the center of said support structure.

2. Support structure (1) according to claim 1, wherein the material of said support structure comprises a plurality of recesses (9).

3. Support structure (1) according to claim 2, wherein all or part of said plurality of recesses (9) are in communication with each other.

4. Supporting structure (1) according to one of claims 2 or 3, wherein the hollow rate increases from the center of the carrier structure to its periphery.

5. Supporting structure according to any one of claims 2 to 4, wherein the trough level at the periphery is greater than 50%, preferably greater than 75%.

6. Bearing structure according to any one of claims 1 to 5, wherein at least one material of said bearing structure has a hardness Shore A between 20 and 95, preferably between 40 and 75

7. Supporting structure according to any one of claims 2 to 6, wherein in the central zone, the Young's modulus is greater than 5 GPa, and preferably greater than 20 GPa.

8. Supporting structure according to any one of claims 2 to 7, wherein all or part of the material is recycled, and / or recyclable and / or is from bio-sourced material.

9. Support structure (1) according to any one of claims 1 to 8, made in the form of a three-dimensional structure (10) comprising a plurality of beams (1 1).

10. Support structure (1) according to claim 9, wherein the beams (1 1) are interconnected by joints (12) of beams.

1 1. Supporting structure (1) according to any one of claims 9 or 10, wherein the beams (1 1) are oriented to form a Voronoi structure, with a Delaunay triangulation.

12. Supporting structure (1) according to any one of claims 1 to 1 1, comprising a hub (5) for mounting said wheel on the vehicle.

13. Supporting structure (1) according to claim 12, wherein the hub (5) comprises at least one reinforcing zone (14), for the realization of fastening means for fixing the hub (5) to the motor vehicle.

14. Support structure (1) according to any one of claims 1 to 13, comprising at least one housing (15) adapted to receive a light block having a light source.

15. Supporting structure (1) according to any one of claims 1 to 14, comprising a plurality of sticks (13) extending radially between the center and the periphery of said support structure.

16. Supporting structure according to one of claims 1 to 15, further comprising a tread (2) having a running surface (3) adapted to be in contact with a roadway.

17. The carrier structure (1) according to claim 16, wherein the tread comprises a plurality of channels (8) extending from the surface of the tread towards the inside of the carrier structure, said channels being communication with all or part of the recesses of said supporting structure.

18. Supporting structure according to any one of claims 2 to 17, also comprising a peripheral reinforcing structure (19) disposed between the surface of the tread and the supporting structure or in the supporting structure, close to the band of rolling.

19. Supporting structure (1) according to any one of claims 1 to 18, produced by additive manufacturing.

20. Supporting structure (1) according to any one of claims 1 to 19, wherein said carrier structure is non-inflated.

21. Supporting structure (1) according to any one of claims 1 to 20, wherein the tread is integrated by additive manufacturing, using the carrier structure as a support.

22. A method of manufacturing a carrier structure (1) adapted to be mounted on a motor vehicle, said carrier structure comprising:

a carrier structure center (4) through which the axis of rotation C-C passes;

a bearing structure periphery adapted to carry a tread (2),

the supporting structure is formed of the same material or mixture or alloy of materials and has a stiffness gradient from the center to the periphery, the rigidity being greater in the center of said supporting structure,

characterized in that said supporting structure is manufactured in whole or in part by additive manufacturing.

23. A method of manufacturing a carrier structure (1) according to claim 22, wherein the carrier structure is manufactured from a hub (5).

24. A method of manufacturing a carrier structure (1) according to one of claims 22 or 23, wherein a tread (2) is manufactured by additive manufacturing on the carrier structure (1).

25. A method of manufacturing a carrier structure (1) according to claim 24, wherein the tread is manufactured in the same manufacturing phase as the carrier structure.

26. A method of manufacturing a carrier structure (1) according to claim 24, wherein the tread is manufactured from a previously manufactured carrier structure.