Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C17/00—Tyres characterised by means enabling restricted operation in damaged or deflated condition; Accessories therefor
  • B60C17/009—Tyres characterised by means enabling restricted operation in damaged or deflated condition; Accessories therefor comprising annular protrusions projecting into the tyre cavity
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C5/00—Inflatable pneumatic tyres or inner tubes
  • B60C5/01—Inflatable pneumatic tyres or inner tubes without substantial cord reinforcement, e.g. cordless tyres, cast tyres
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C7/00—Non-inflatable or solid tyres
  • B60C7/10—Non-inflatable or solid tyres characterised by means for increasing resiliency
  • B60C7/12—Non-inflatable or solid tyres characterised by means for increasing resiliency using enclosed chambers, e.g. gas-filled
  • B60C7/125—Non-inflatable or solid tyres characterised by means for increasing resiliency using enclosed chambers, e.g. gas-filled enclosed chambers defined between rim and tread
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C7/00—Non-inflatable or solid tyres
  • B60C7/10—Non-inflatable or solid tyres characterised by means for increasing resiliency
  • B60C7/14—Non-inflatable or solid tyres characterised by means for increasing resiliency using springs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C7/00—Non-inflatable or solid tyres
  • B60C7/10—Non-inflatable or solid tyres characterised by means for increasing resiliency
  • B60C7/14—Non-inflatable or solid tyres characterised by means for increasing resiliency using springs
  • B60C7/146—Non-inflatable or solid tyres characterised by means for increasing resiliency using springs extending substantially radially, e.g. like spokes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers

Definitions

• the present invention relates to a pneumatic type device intended to equip a vehicle.
• This pneumatic device can be used on all types of vehicles such as two-wheeled vehicles, passenger vehicles, trucks, agricultural vehicles, civil engineering or aircraft or, more generally, on any rolling device.
• a conventional tire is a toric structure, intended to be mounted on a rim, pressurized by an inflation gas and crushed on a ground under the action of a load.
• the tire has at all points of its rolling surface, intended to come into contact with a ground, a double curvature: a circumferential curvature and a meridian curvature.
• circumferential curvature is meant a curvature in a circumferential plane, defined by a circumferential direction, tangent to the running surface of the tire according to the rolling direction of the tire, and a radial direction, perpendicular to the axis of rotation of the tire.
• meridian curvature is meant a curvature in a meridian or radial plane, defined by an axial direction parallel to the axis of rotation of the tire, and a radial direction perpendicular to the axis of rotation of the tire.
• the expression “radially inner, respectively radially outer” means “closer to, respectively farther from the axis of rotation of the tire”.
• the expression “axially inner, respectively axially outer” means “closer or farther away from the equatorial plane of the tire", the equatorial plane of the tire being the plane passing through the middle of the running surface of the tire and perpendicular to the tire. rotation axis of the tire.
• a conventional tire of the state of the art generally has a large meridian curvature, that is to say a small radius of meridian curvature, at the axial ends of the tread, called shoulders, when the pneumatic, mounted on its mounting rim and inflated to its recommended operating pressure, is subject to its service charge.
• the mounting rim, operating pressure and service load are defined by standards, such as, for example, the standards of the European Tire and Rim Technical Organization (ETRTO).
• a conventional tire carries the load applied, essentially by the axial ends of the tread, or shoulders, and by the flanks connecting the tread to beads ensuring the mechanical connection of the tire with its mounting rim. It is known that a meridian flattening of a conventional tire, with a small meridian curve at the shoulders, is generally difficult to obtain.
• US Pat. No. 4,235,270 describes a tire having an annular body made of elastomeric material, comprising a radially external cylindrical part, at the periphery of the tire, which may comprise a tread, and a radially inner cylindrical part, intended to be mounted on a rim.
• a plurality of walls, circumferentially spaced, extend from the radially inner cylindrical portion to the radially outer cylindrical portion, and provide load bearing.
• flanks may connect the two cylindrical portions respectively radially inner and radially outer, to form, in association with the tread and the sidewalls, a closed cavity and thus allow the pressurization of the tire.
• Such a tire has a high mass, compared to a conventional tire, and, because of its massive nature, is likely to dissipate high energy, which can limit its endurance, and therefore its lifetime.
• WO 2009087291 discloses a pneumatic structure comprising two annular rings respectively internal, or radially inner, and outer or radially outer, connected by two sidewalls and a carrier structure.
• the carrier structure is pressurized and shares the annular volume of the tire in a plurality of compartments or cells, and the flanks are connected or integrated with the supporting structure.
• the load applied is carried by both the carrier structure and the sidewalls.
• the pressure distribution in the contact area is not homogeneous in the axial width of the contact area, with overpressures at the shoulders due to the meridian flattening difficulty due to the connection between the flanks and the supporting structure. These overpressures at the shoulders are likely to generate significant wear of the shoulders of the tread.
• WO 2005007422 discloses an adaptive wheel comprising an adaptive band and a plurality of radii extending radially inwardly from the adaptive band to a hub.
• the adaptive strip is intended to adapt to the surface of contact with a soil and to cover the obstacles.
• the spokes transmit the load carried between the adaptive strip and the hub, thanks to the tensioning of the spokes which are not in contact with the ground.
• Such an adaptive wheel requires an optimization of the distribution of the spokes to ensure a substantially cylindrical periphery.
• an adaptive wheel has a relatively high mass compared to a conventional tire.
• the document WO 2016116490 describes a device of the pneumatic type, intended to equip a vehicle, with an improved flattening of its tread with respect to a conventional tire.
• the pneumatic type device comprises a radially outer revolution structure, intended to come into contact with a ground, a radially inner revolution structure, coaxial with the radially outer revolution structure and intended to ensure connection with a mounting means, a an inner annular space radially delimited by the two structures of revolution, and a supporting structure, at least partially connecting the two structures of revolution, constituted by a plurality of independent two-to-two carrier members subjected to compression buckling in the area of contact with the ground.
• the smallest characteristic dimension E of the section S of any carrier element is at most equal to 0.02 times the average radial height H of the inner annular space
• the surface density D of the elements carriers per unit area of radially outer rotational structure, expressed in 1 / m 2 is at least equal to Z / (A * ⁇ Fr / n), where Z is the nominal radial load, expressed in N, A is the ground contact area, expressed in m 2 , and ⁇ Fr / n the average tensile breaking force of the n load-bearing elements subjected to compression buckling, expressed in terms of N, and the pneumatic type device comprises two sidewalls, not related to the supporting structure and closing the inner annular space, constituting a closed cavity that can be pressurized.
• the present invention aims to provide a pneumatic type device with an improved flattening of its tread, when subjected to a load.
• a pneumatic device intended to equip a vehicle, comprising:
• a radially outer revolution structure whose axis of revolution is the axis of rotation of the pneumatic type device and intended to come into contact with a ground by means of a tread comprising at least one elastomeric material, the radially outer revolution structure having two axial ends and comprising a circumferential reinforcing reinforcement,
• a radially inner revolution structure coaxial with the radially outer revolution structure and intended to ensure the connection of the pneumatic type device with a mounting means on the vehicle, the radially inner revolution structure having two axial ends and comprising at least a polymeric material,
• the surface density D of the carrier elements per unit area of radially external structure of revolution expressed in 1 / m 2 , being at least equal to Z / (A * ⁇ Fr / n), where Z is the nominal radial load, expressed in N, A is the ground contact area, expressed in m 2 , and ⁇ Fr / n the average tensile breaking force of the n load bearing elements subjected to compression buckling, expressed in N,
• the principle of a pneumatic type device according to the invention is to have a load-bearing structure, consisting of independent two-to-two bearing elements in the inner annular space, and capable of carrying the load applied to the pneumatic device. by putting a portion of the load-bearing elements positioned outside the contact area under tension, the n load-bearing elements positioned in the contact area being subjected to buckling in compression and therefore not participating in the wearing of the applied load .
• Each carrier element extends continuously from the radially outer revolution structure to the radially inner revolution structure, that is to say along a path comprising a first end in interface with the revolution structure. radially outer and a second end interfaced with the radially inner revolution structure.
• the carrier elements are two to two independent in the inner annular space, that is to say not mechanically linked together in the inner annular space, so that they have independent mechanical behavior. For example, they are not linked together to form a network or trellis. They function as independent stays.
• Each carrier element has a tensile force Fr and an average section S, these two characteristics are not necessarily identical for all the elements.
• the average section S is the average of the sections obtained by cutting the carrier element by all the cylindrical surfaces, coaxial with the two radially outer and radially outer surfaces of revolution, and radially between said two surfaces of revolution.
• the mean section S is the constant section of the carrier element.
• the smallest characteristic dimension E of the average section S of any carrier element is at most equal to 0.02 times the average radial height H of the inner annular space.
• This characteristic excludes any massive carrier element, having a large volume.
• each carrier element has a high slenderness, in the radial direction, allowing it to flare at the passage in the contact area. Outside the contact area, each carrier element returns to its original geometry, because its buckling is reversible. Such a carrier element has a good resistance to fatigue.
• the carrier elements of the carrier structure have an initial length Lp strictly greater than the average radial height H and at most equal to 1.1 times the average radial height H.
• the average radial height H of the inner annular space is the distance between the radially inner face of the radially outer revolution structure and the radially outer face of the radially inner revolution structure. This distance H is measured on the pneumatic type device in its initial state, that is to say mounted on its mounting means, inflated to a recommended pressure but not subject to a load Z.
• the recommended pressure can if necessary to be null: in this case, the tire is not inflated and supports the load only by its structure.
• An initial length Lp carrier element strictly greater than the average radial height H implies that any carrier element is expanded in the initial state of the pneumatic type device.
• the carrying elements When the pneumatic type device is subjected to the load Z, the carrying elements, outside the area of contact with the ground, are stretched, and at least some of them become rectilinear, because the average radial height increases outside the contact area, due to the appearance of a counter-arrow.
• the load-bearing elements in the contact area on the other hand, remain relaxed.
• the elongation of the load-bearing elements under load allows greater radii of curvature in any circumferential plane, at the entrance and at the exit of the contact area, and thus facilitates circumferential flattening of the pneumatic-type device.
• the surface density D of the carrier elements per unit area of radially external structure of revolution is at least equal to Z / (A * ⁇ Fr / n), where Z is the nominal radial load, expressed in N, A is the ground contact area, expressed in m 2 , and Fr / n is the average tensile breaking force of the n load bearing elements subjected to compression buckling, expressed in N.
• ⁇ Fr / n is the average tensile breaking strength of the n load bearing elements subjected to compression buckling, each having a tensile breaking force Fr which is not necessarily constant over all the bearing elements.
• the distribution of the load-bearing elements is optimized and the surface density of the load-bearing elements is sufficiently high to guarantee a flattening of the tread, to the passage in the contact area, both in a circumferential plane and in a meridian plane, improved over conventional tires and other pneumatic devices known from the state of the art.
• the distribution of the load-bearing members is more uniformly distributed and denser than in the pneumatic type devices of the state of the art, both circumferentially and axially, which contributes to conferring on the tread a quasi-cylindrical geometry, with a so-called "daisy effect" effect decreased.
• the pneumatic device of the invention comprises two flanks, connecting the axial ends of the respectively radially external and radially inner revolution structures and axially delimiting the inner annular space, so that the The inner annular space constitutes a closed cavity which can be pressurized by an inflation gas.
• the flanks according to their design and, in particular, according to their structural rigidity, may participate more or less in the wearing of the applied load.
• the flanks generally comprise at least one elastomeric material and may optionally comprise a reinforcing reinforcement.
• the flanks may or may not be directly related to the supporting structure. In the case where they are not directly related to the supporting structure, the flanks have an autonomous mechanical behavior, without affecting the proper mechanical operation of the supporting structure.
• the pneumatic type device in combination with the two respectively radially outer and radially inner revolution structures, they close the inner annular space which then constitutes a closed cavity that can be pressurized or not by an inflation gas.
• the pneumatic type device In the case of effective pressurization by an inflation gas, the pneumatic type device then has a pneumatic rigidity, due to the pressure, which will also contribute to the carrying of the applied load. The higher the pressure, the higher the contribution of the pneumatic stiffness to the load carrying capacity applied, and, correlatively, the greater the contribution of the structural rigidity of the bearing structure and / or the flanks and / or the respective structures of revolution respectively.
• radially outer and radially inner to the port of the applied load is low.
• the bearing structure and the respectively radially outer and radially inner revolution structures ensure the entire load port, the flanks playing only a part. protection against possible attacks by elements external to the pneumatic type device.
• the combination of these essential characteristics allows an improved flattening of the tread, particularly in a meridian plane, by increasing meridian radii of curvature at the axial ends of the tread.
• An initial length Lp of the carrier element is advantageously at least equal to 1.01 times the average radial height H, still more advantageously at least equal to 1.03 times the average radial height H, or even at least equal to 1.05 times the radial height. average H.
• the surface density of the carrier elements per unit area of radially outer revolution structure is advantageously at least equal to 3 * Z / (A * ⁇ Fr / n).
• a higher surface density of carrier elements improves the homogenization of pressures in the ground contact area and guarantees a higher safety factor with respect to the applied load and with respect to endurance .
• the surface density of the carrier elements per unit area of radially outer revolution structure is still advantageously at least equal to 6 * Z / (A * ⁇ Fr / n).
• An even higher surface density of carrier elements further improves the homogenization of the pressures in the ground contact area and further increases the safety factor with respect to the applied load and with respect to endurance.
• all the carrier elements have a fracture force in identical Fr traction.
• the load-bearing elements have the same tensile breaking strength, without necessarily having the same geometric characteristics and / or the same constituent materials.
• the average tensile breaking force of the n load elements under compression buckling ⁇ Fr / n is equal to the tensile breaking force Fr of any bearing element.
• the surface density D of the carrier elements per unit area of radially external structure of revolution, expressed in 1 / m 2 is at least equal to Z / (A * Fr), where Z is the nominal radial load, expressed in N, A is the ground contact area, expressed in m 2 , and Fr the tensile strength of any load bearing element, expressed in N.
• the probability of failure by tensile failure of the load-bearing elements is thus the same. at every point of the supporting structure.
• the carrier elements are identical, that is to say that their geometric characteristics and constituent materials are identical.
• their tensile fracture forces Fr being identical, the surface density D of the carrier elements per unit area of radially external structure of revolution, expressed in 1 / m 2 , is at least equal to Z / (A * Fr) , where Z is the nominal radial load, expressed in N, A is the ground contact area, expressed in m 2 , and Fr is the tensile strength of any load-bearing element, expressed in N.
• a carrier structure with elements advantageously have a homogeneous mechanical behavior and have the advantage of greater ease of manufacture.
• any carrier element is unidimensional with a shape ratio K at most equal to 3.
• a carrier element is considered to be one-dimensional, when the largest dimension characteristic L of its mean section S is at most equal to 3 times the smallest characteristic dimension E of its mean section S.
• a one-dimensional carrier element has a mechanical behavior of filarious type, that is to say that it can not be subjected only to extension or compression efforts along its average line.
• textile reinforcements consisting of an assembly of textile yarns, or metal cords, constituted by an assembly of metal threads, can be considered as one-dimensional load-bearing elements, since their average section S being substantially circular, the form ratio K is equal to 1, therefore less than 3.
• an unidimensional carrier element in extension has a rectilinear mean line
• its mean line is not necessarily radial, that is to say perpendicular to the axis of rotation of the tire.
• Such a carrier element is not comparable to a radius.
• This non-radial direction of the mean line makes it possible, in particular, to adjust the rigidities of the pneumatic device in the directions respectively axial and circumferential.
• the surface density D of the identical unidimensional bearing elements per unit area of radially external structure of revolution is advantageously at least equal to 5000 .
• any carrier element is two-dimensional with a shape ratio K at least equal to 3.
• a carrier element is considered two-dimensional, when the largest characteristic dimension L of its mean section S is at least equal to 3 times the smallest characteristic dimension E of its mean section S.
• a two-dimensional carrier element has a membrane-type mechanical behavior, that is to say that it can not be subjected only to extension or compression forces in its thickness defined by the smallest characteristic dimension E of its middle section S.
• any carrier element is two-dimensional strap type with a form ratio K at least equal to 3 and at most equal to 50.
• the surface density D of the identical two-dimensional load-bearing members of the strip type per unit area of radially outer revolution structure is advantageously at least equal to 600 and at most equal to 15,000.
• any carrier element is two-dimensional film type with a form ratio K at least equal to 50.
• the surface density D of the identical two-dimensional carrier elements of film type per unit area of radially external structure of revolution is advantageously at least equal to 100 and at most equal to 1000.
• the largest characteristic dimension L of the average section S of a two-dimensional film-type carrier element is at most equal to 0.9 times the smallest of axial widths of the respectively radially outer and radially inner revolution structures, the respective axial widths of the respectively radially outer and radially inner revolution structures being not necessarily equal.
• the carrier element is then a so-called through film then circumferentially separating the inner cavity of the tire into cells or cells.
• a two-dimensional carrier element is plane
• its average plane is not necessarily radial, that is to say perpendicular to the axis of rotation of the tire.
• Such a carrier element is not comparable to a radius.
• This non-radial direction of the average plane makes it possible, in particular, to adjust the rigidities of the pneumatic device in the directions respectively axial and circumferential.
• any carrier element advantageously comprises a polymer type material or metal or glass or carbon.
• Polymers, in particular elastomers, and metal, such as steel, are commonly used in the tire field. Glass and carbon are alternative materials conceivable for use in pneumatics.
• any carrier element advantageously comprises polyethylene terephthalate (PET). PET is commonly used in the tire field because of a good compromise between its mechanical properties, such as tensile strength and cost.
• PET polyethylene terephthalate
• any carrier element also advantageously comprises an aliphatic polyamide, such as nylon. Nylon is also commonly used in the tire field for the same reasons as PET.
• any carrier element has a homogeneous structure, comprising a single component. It is the simplest structure envisaged, such as, for example, a wire or a membrane.
• any carrier element has a composite structure, comprising at least two constituents. It is a structure constituted by an assembly of at least two elements, such as, for example, a cable constituted by a set of elementary wires.
• any carrier element comprises a single material: for example, a wire or a cable of textile material.
• any carrier element comprises at least two materials.
• the sidewalls are not directly related to the carrier structure. They may or may not participate in carrying the load, according to their own structural rigidity. In the case where they participate in the carrying of the load, they have an independent mechanical behavior and do not interfere in the mechanical behavior of the supporting structure.
• each flank having a curvilinear length L F the curvilinear length L F of each flank is advantageously at least equal to 1.05 times, preferably 1.15 times the height. mean radial H of the inner annular space. Even more advantageously, the curvilinear length L F of each flank is at least equal to 1.3 times and at most equal to 1.6 times the average radial height H of the inner annular space. This flank length feature ensures that sidewall deformation will not disturb the meridian flattening of the pneumatic type device with low curvature.
• the circumferential reinforcing reinforcement of the radially outer revolution structure advantageously comprises at least one reinforcing layer comprising textile or metal reinforcing elements.
• the radially outer revolution structure comprises a reinforcing reinforcement comprising at least one reinforcing layer constituted by reinforcing wire elements, most often of metal or textile, embedded in a reinforcement. elastomeric material. This reinforcing reinforcement is most often radially interior to a tread.
• the assembly constituted by the reinforcing reinforcement and the tread constitutes the radially outer shell of revolution.
• the radially inner revolution structure also advantageously comprises on a radially inner face a connecting layer intended to be fixed on the mounting means on the vehicle.
• the tie layer generally comprises at least one elastomeric material, but not necessarily reinforcing reinforcement. Attachment to the mounting means may be effected by the pressure forces resulting from inflating the pneumatic device.
• the radially inner revolution structure comprises on a radially inner face a connecting layer intended to be fixed to the mounting means on the vehicle, by gluing.
• a bonded connection makes it possible to avoid any rotation of the pneumatic-type device with respect to the mounting means on the vehicle.
• the invention also relates to a mounted assembly comprising a pneumatic device according to one of the embodiments described above, mounted on a mounting means on the vehicle.
• the pneumatic device of the invention may be manufactured, for example, according to the method described below.
• the supporting structure is manufactured separately in the form of a composite structure of sandwich type, constituted by a first elastomeric layer, intended to be secured to the radially inner revolution structure, a second elastomeric layer, intended to be secured to the radially outer revolution structure and by carrier elements extending from the first elastomeric layer to the second elastomeric layer. Any known method of manufacturing composite sandwich structure can be used.
• the pneumatic device can be manufactured according to the following process steps:
• the assembly mounted according to the invention can be achieved by fixing the pneumatic type device on a mounting means, such as a rim.
• This attachment can be achieved, for example, by bonding the radially inner face of the radially inner revolution structure to the radially outer face of the mounting means.
• FIG. 2A view of a circumferential section of a pneumatic type device according to the invention, in the initial state
• FIG. 2B view of a circumferential cut of a pneumatic type device according to the invention, in the overwritten state
• FIG. 3A view of a meridian section of a pneumatic type device according to the invention, in the case of a carrier structure with unidimensional bearing elements - Figure 3B: perspective view of a one-dimensional bearing element
• FIG. 4A view of a meridian section of a pneumatic type device according to the invention, in the case of a carrier structure with two-dimensional carrying elements of the lanyard type
• FIG. 4B perspective view of a two-dimensional carrier element of lanyard type
• FIG. 5A view of a meridian section of a pneumatic type device according to the invention, in the case of a carrier structure with two-dimensional film-type carrying elements
• FIG. 5B perspective view of a two-dimensional film-type carrier element
• FIG. 6 comparative standard curves of the evolution of the load applied as a function of the deflection for a pneumatic type device according to the invention (filamentary load-bearing elements) and a reference tire of the state of the art.
• FIG. 7 Comparative standard curves of the evolution of the drift rigidity as a function of the load applied for a pneumatic type device according to the invention (filamentary load-bearing elements) and a reference tire of the state of the art .
• FIG. 1 shows a perspective view in partial section of a pneumatic type device 1 according to the invention, mounted on a mounting means 4 or rim, and comprising a radially outer revolution structure 2, a structure of radially inner revolution 3, an inner annular space 5, a carrier structure 6 and two sidewalls 8.
• the radially outer revolution structure 2 has an axis of revolution which is the axis of rotation YY 'of the pneumatic device and is intended to contacting a soil through a tread 21 comprising at least one elastomeric material.
• the radially outer revolution structure 2 comprises a reinforcing circumferential reinforcement 22 constituted, in the present case, by a single reinforcing layer.
• the radially inner revolution structure 3, coaxial with the radially outer revolution structure 2, is intended to ensure the connection of the pneumatic type device 1 with the mounting means 4.
• the radially inner revolution structure 3 comprises at least one polymeric material , most often an elastomeric mixture.
• the inner annular space 5 is radially delimited by the respectively radially outer and radially inner revolution structures 3.
• the carrier structure 6, according to the invention, is constituted by a plurality of carrier elements 7, extending continuously from from the radially outer revolution structure 2 to the radially inner revolution structure 3, two to two independent in the inner annular space 5.
• the pneumatic type device 1 comprises two flanks 8, connecting the axial ends of the respectively radially outer and radially inner revolution structures 3 and axially delimiting the inner annular space 5, so that the inner annular space 5 constitutes a closed cavity which can be pressurized by a gas of inflation.
• Figure 2A shows a circumferential section of a pneumatic type device 1 according to the invention, mounted on a mounting means 4, in its initial state, that is to say inflated to a recommended pressure but not Z.
• the recommended pressure may be zero if necessary: in this case, the tire is uninflated and supports the load only by its structure.
• the carrier structure 6 is constituted by a plurality of wire carrying elements 7, extending continuously from the radially outer revolution structure 2 to the radially inner revolution structure 3, two by two independent in the annular space. 5.
• the carrier elements 7 are relaxed, that is to say have a non-rectilinear geometry, because their initial length Lp is greater than the average radial height H of the inner annular space 5.
• the FIG. 2A represents a particular embodiment of the invention with identical and radially oriented bearing elements 7.
• the surface density D of the carrier elements 7 per unit area of radially outer revolution structure 2, expressed in 1 / m 2 is at least equal to Z / (A * Fr), where Z is the nominal radial load, expressed in N, A is the ground contact area, expressed in m 2 , and Fr the tensile strength of any load bearing element, expressed in N.
• Figure 2B shows a circumferential section of a pneumatic type device 1 according to the invention, mounted on a mounting means 4, in its crushed state, that is to say subjected to a nominal radial load Z
• the pneumatic type device 1, subjected to a nominal radial load Z is in contact with a plane ground by a contact surface A, having a circumferential length X A.
• the load-bearing elements 72 outside the area of contact with the ground, are stretched, that is to say become rectilinear in the case shown, because the height mean radial increases outside the area of contact, due to the appearance of a counter-arrow.
• the carrier elements 71, in the contact area remain relaxed.
• FIG. 3A shows a meridian section of a pneumatic type device 1 according to the invention, mounted on a mounting means 4, in the case of a carrier structure 6 with one-dimensional carrying elements 7.
• the pneumatic type device 1 comprises a radially outer revolution structure 2, a radially inner revolution structure 3, an inner annular space 5, a carrier structure 6 and two sidewalls 8.
• the pneumatic type device 1, subjected to a nominal radial load Z, is in contact with a plane ground by a contact surface A, having an axial width Y A.
• all the carrier elements 7 are identical and are oriented radially, therefore have a length equal to the average radial height H of the inner annular space 5.
• the carrier elements 7, positioned opposite of the contact area are in tension, while the carrier elements 7, connected to the radially outer rotational structure portion 2 in contact with the ground, are subjected to compression buckling.
• FIG. 3B shows a one-dimensional carrier element 7 having a circular average section S, defined by a smaller characteristic dimension E and a larger characteristic dimension L both equal to the diameter of the circle, and characterized by its K-form ratio. equal to L / E.
• the smallest characteristic dimension E of the average section S of the carrier element 7, that is to say, in this case, its diameter, is at most equal to 0.02 times the average radial height H of the space
• the shaped ratio K is equal to 1.
• the carrier element 7 being oriented radially, its length 1 is equal to the average height H of the inner annular space. 5.
• Figure 4A shows a meridian section of a pneumatic type device 1 according to the invention, mounted on a mounting means 4, in the case of a carrier structure 6 with two-dimensional carrier elements 7 of the strap type.
• the pneumatic type device 1 comprises a radially outer revolution structure 2, a radially inner revolution structure 3, an inner annular space 5, a carrier structure 6 and two sidewalls 8.
• the pneumatic type device 1, subjected to a nominal radial load Z, is in contact with a plane ground by a contact surface A, having an axial width Y A.
• all the carrier elements 7 are identical and are oriented radially, therefore have a length equal to the average radial height H of the inner annular space 5.
• the carrier elements 7, positioned opposite of the contact area are in tension, while the supporting elements 7, connected to the portion of radially outer revolution structure 2 in contact with the ground, are subjected to buckling in compression.
• FIG. 4B shows a two-dimensional stripe type carrier element 7 having a rectangular mean section S, defined by its smallest characteristic dimension E, or thickness, and its largest characteristic dimension L, or width, and characterized by its ratio. of form K equal to L / E.
• the smallest characteristic dimension E of the average section S of the carrier element 7, that is to say, in this case, its thickness, is at most equal to 0.02 times the average radial height H of the space 5.
• the shape ratio K at least equal to 3 and at most equal to 50.
• the carrier element 7 being oriented radially, its length 1 is equal to the average height H of the inner annular space 5.
• Figure 5A shows a meridian section of a pneumatic type device 1 according to the invention, mounted on a mounting means 4, in the case of a carrier structure 6 with two-dimensional carrier elements 7 of the film type.
• the pneumatic type device 1 comprises a radially outer revolution structure 2, a radially inner revolution structure 3, an inner annular space 5, a carrier structure 6 and two sidewalls 8.
• the pneumatic type device 1, subjected to a nominal radial load Z, is in contact with a plane ground by a contact surface A, having an axial width YA.
• all the carrier elements 7 are identical and are oriented radially, therefore have a length equal to the average radial height H of the inner annular space 5.
• FIG. 5B shows a two-dimensional film-type carrier member 7 having a rectangular mean section S, defined by its smallest characteristic dimension E, or thickness, and its largest characteristic dimension L, or width, and characterized by its ratio. of form K equal to L / E.
• the smallest characteristic dimension E of the average section S of the carrier element 7, that is to say, in this case, its thickness, is at most equal to 0.02 times the average radial height H of the space
• the shape ratio K is at least equal to 50.
• the carrier element 7 being oriented radially, its length 1 is equal to the average height H of the inner annular space 5.
• FIG. 6 shows two compared standard curves of the evolution of the applied load Z, expressed in daN, as a function of the arrow F, expressed in mm, for a pneumatic type device according to the invention I, in the case of a carrier structure with identical one-dimensional bearing elements, and a reference tire R of the state of the art.
• This figure shows that, for a given radial load Z, the arrow F of a pneumatic type device according to the invention I is smaller than that of the reference tire R. Otherwise, the radial rigidity of the pneumatic device I is greater than the radial stiffness of the reference tire R.
• FIG. 7 presents two compared standard curves of the evolution of the drift rigidity, expressed in N / °, as a function of the load applied, expressed in N, for a pneumatic type device according to the invention, in the case of a carrier structure with identical one-dimensional carrier elements, and a reference tire of the state of the art.
• This figure shows that, for a given radial load Z, the drift rigidity Z of a pneumatic type device according to the invention I is greater than that of the reference tire R.
• the invention has been more particularly studied as an alternative solution to a conventional tire for a passenger vehicle.
• the pneumatic type device studied whose stiffness characteristics are presented in FIGS. 6 and 7 previously described, comprises two radially outer and radially inner revolution structures having respective average radii equal to 333 mm and 289 mm, and axial widths both equal to 250 mm.
• the inner annular space, radially delimited by the respectively radially outer and radially inner revolution structures, has an average radial height H equal to 35 mm.
• the supporting structure consists of one-dimensional son-type carrying elements.
• Each carrier element made of polyethylene terephthalate (PET) has a mean section S equal to 7 * 10 -8 m 2 and a breaking stress equal to 470 MPa.
• the surface density D of the carrier elements per unit area of the structure of revolution radially external is equal to 85000 son / m 2.
• the pneumatic type structure inflated to a pressure p between 1.5 bar and 2.5 bar, is subjected to a radial load Z equal to 1000 daN.
• the carrier structure according to the invention preferably consists of identical bearing elements, both in form ratio K, in structure and in material, it may be constituted by any combination of load-bearing elements, such as , for example and non-exhaustively:
• one-dimensional carrier elements having K-form ratios and / or different structures and / or materials
• two-dimensional carrier elements having K-form ratios and / or different structures and / or materials

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Tires In General (AREA)

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• 2016
  • 2016-07-29 FR FR1657338A patent/FR3054484A1/fr not_active Withdrawn
• 2017
  • 2017-07-27 EP EP17754412.9A patent/EP3490813A1/de not_active Withdrawn
  • 2017-07-27 WO PCT/FR2017/052097 patent/WO2018020163A1/fr unknown

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