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
  • 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
  • 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
  • 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
  • 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
  • B60C9/02—Carcasses
• • 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 type device is designed preferentially for passenger vehicles, but can be used on any other type of vehicle such as two-wheeled vehicles, heavy goods vehicles, agricultural vehicles, civil engineering vehicles 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.
• This object has been achieved, according to the invention, by a pneumatic type 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 a radially inner face having a surface S, and the radially outer revolution structure 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 a radially facing face; exterior, and the radially inner revolution structure comprising at least one polymeric material,
• a supporting structure consisting of a plurality of identical, two to two independent, that is to say non-mechanically interconnected, bearing elements in the inner annular space, the bearing elements extending continuously from the radially inner face of the radially outer revolution structure, to the radially outer face of the radially inner revolution structure, such that when the pneumatic type device is subjected to a nominal radial load Z and is in contact with a plane ground by a contact surface A, the carrier elements, connected to the radially outer portion of the structure of revolution in contact with the ground, are subjected to a compression buckling and at least a portion of the carrier elements, connected to the portion of the radially external revolution structure not in contact with the ground, are in tension, the supporting elements of the structure in because they are filthy, the carrier elements of the carrier structure having an initial length L P strictly greater than the average radial height H and at most equal to 1.1 times the average radial height H,
• the carrying elements of the bearing structure being connected to the radially inner face of the radially outer revolution structure by a radially outer fabric, covering at least partly said radially inner face on a connecting surface SE, and being connected to the face; radially outer of the radially inner revolution structure by a radially inner fabric, covering at least partly said radially outer face, the assembly consisting of the supporting structure, the radially outer fabric and the radially inner fabric being a sandwich structure,
• the average 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 (S / SE) * Z / (A * F R ), where S is the area, expressed in m 2 , of the radially inner face of the radially outer revolution structure, SE is the connecting surface, expressed in m 2 , of the radially outer fabric with the radially inner face of the radially outer revolution structure, Z is the nominal radial load, expressed in N, applied to the pneumatic type device, A is the ground contact area, expressed in m 2 , of the pneumatic type device, and F R is the tensile breaking force, expressed in N, of each carrier element,
• a pneumatic type device comprising two flanks, connecting in pairs the axial ends of the respectively radially outer and radially inner revolution structures and axially delimiting the inner annular space, so that the inner annular space constitutes a closed cavity which can be pressurized by an inflation gas.
• a pneumatic type device essentially comprises two respectively radially outer and radially inner revolution structures, separated by an inner annular space and connected by a bearing structure.
• the principle of a pneumatic type device is to have a carrier structure, consisting of identical bearing elements, two by two independent in the inner annular space, and capable of carrying the load applied to the pneumatic type device by tensioning a part of the carrier elements positioned outside contact area, the carrier elements positioned in the contact area being subjected to buckling in compression and therefore not participating in the carrying of the applied load.
• the carrier structure is constituted by a plurality of identical carrier elements, that is to say whose geometric characteristics and constituent materials are identical.
• 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.
• Each carrier element extends continuously from the radially inner face of the radially outer revolution structure to the radially outer face of the radially inner revolution structure, that is to say along a trajectory comprising a first end connected to the radially inner face of the radially outer revolution structure and a second end connected to the radially outer face of the radially inner revolution structure.
• the carrier elements of the carrier structure are filial, that is to say one-dimensional elements similar to son.
• Each carrier element can be characterized geometrically by its length L P and its mean section Sp, which is the average of the sections obtained by the section of the carrier element by all the cylindrical surfaces, coaxial with the two structures of revolution respectively radially outer and radially outer, and radially between said two structures of revolution.
• the mean section Sp is equal to this constant section.
• a carrier element is said to be filamentary or one-dimensional when the smallest characteristic dimension E of its mean section Sp is at most equal to 0.02 times the average radial height H of the inner annular space and when the form ratio K of its mean section Sp is at most equal to 3.
• 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.
• a form ratio K of its mean section Sp at most equal to 3 means that the largest characteristic dimension L of its mean section Sp is at most equal to 3 times the smallest characteristic dimension E of its mean section Sp.
• a wired carrier element has a mechanical behavior of filial type, that is to say that it can be subjected only to extension or compression efforts along its average line.
• textile reinforcements consisting of an assembly of textile spun yarns, or metal cords, consisting of an assembly of metal threads, may be considered as wired load-bearing elements, since their average section Sp being substantially circular, the form ratio K is equal to 1, therefore less than 3.
• all the wired load-bearing elements of a carrier structure do not necessarily have identical lengths L P.
• 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 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 of 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 load-bearing elements outside the area of contact with the ground, are stretched, and at least a portion of them become straight, since the average radial height increases in outside the contact area, due to the appearance of a counter-arrow.
• the load-bearing elements in the contact area 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 carrier elements of the carrier structure are connected to the radially inner face of the radially outer revolution structure by a radially outer fabric, covering at least in part said radially inner face on a connecting surface.
• SE and are connected to the radially outer face of the radially inner revolution structure by a radially inner fabric, covering at least partly said radially outer face, the assembly consisting of the supporting structure, the radially outer fabric and the radially radially interior being a sandwich structure.
• two radially outer and radially inner tissues respectively serve as interfaces between the bearing elements and the respectively radially outer and radially inner revolution structures, which are therefore not in direct contact.
• the connecting surface SE of the radially outer fabric with the radially outer face of the radially inner revolution structure is not necessarily identical to the surface S of the radially outer face of the radially inner revolution structure.
• the radially outer fabric is not necessarily continuous and may consist of juxtaposed fabric elements: in this case, the bonding surface SE of the radially outer fabric with the radially outer face of the radially inner revolution structure is the sum of connecting surfaces of the juxtaposed fabric elements.
• the connecting surface SE is at most equal to the surface S, that is to say that the radially outer fabric does not necessarily completely cover the radially inner face of the radially outer revolution structure.
• connection surface Si of the radially inner fabric with the radially outer face of the radially inner revolution structure is at most equal to the surface S 'of the radially outer face of the radially inner revolution structure; that is to say that the radially inner fabric does not necessarily completely cover the radially outer face of the radially inner revolution structure.
• the radially inner fabric is not necessarily continuous and may consist of juxtaposed fabric elements: in this case, the bonding surface Si of the radially inner fabric with the radially outer face of the structure of radially inner revolution is the sum of the connecting surfaces of the juxtaposed fabric elements.
• This design advantageously allows to have a sandwich structure that can be independently manufactured and integrated in one piece during the manufacture of the pneumatic type device.
• the sandwich structure thus obtained may be secured to the respectively radially outer and radially inner revolution structures by vulcanization, bonding or any other method of connecting the radially outer and radially inner tissues, respectively.
• the average 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 (S / S E ) * Z / ( A * F r ), where S is the area, expressed in m 2 , of the radially inner face of the radially outer revolution structure, S E is the bonding area, expressed in m 2 , of the radially outer fabric with the face radially inwardly of the radially outer revolution structure, Z is the nominal radial load, expressed in N, applied to the pneumatic type device, A is the ground contact area, expressed in m 2 , of the pneumatic type device, and F r tensile strength, expressed in N, of each carrier element.
• the nominal radial load Z is the recommended load for the use of the pneumatic type device.
• the ground contact surface A is the area in which the pneumatic type device is crushed on the ground under the action of the nominal radial load Z.
• This expression reflects, in particular, the fact that the average surface density D of the carrier elements per unit area of radially outer revolution structure is greater than the nominal radial load Z high and / or that the ratio surface S E / S, representing the recovery rate of the radially inner face of the radially outer revolution structure by the radially outer fabric is low.
• the average surface density D of the carrier elements is even lower than the tensile breaking force F r of a carrier element is high.
• Such an average surface density D of the load-bearing elements makes it possible, on the one hand, for the load-bearing members extending outside the contact area to carry the nominal radial load Z, and, on the other hand, for the load-bearing members. in compression in the contact area to ensure a flattening of the tread, both in a circumferential plane and in a meridian plane, improved over conventional tires and other pneumatic type devices known from the state of the art.
• the average surface density of the carrier elements is constant both in the circumferential direction and in the axial direction, that is to say that the distribution of the carrier elements is uniform both circumferentially and axially: the average surface density D is therefore equal to the constant surface density.
• the advantage of a constant surface density is to contribute to giving the tread a quasi-cylindrical geometry, with a so-called “daisy effect" effect decreased compared to other pneumatic type devices of the state of the art. the technique.
• the average surface density of the carrier elements may be variable in the circumferential direction and / or in the axial direction, that is to say that the distribution of the carrier elements is not necessarily uniform circumferentially and / or axially, from which the introduction of the average surface density characteristic D.
• the pneumatic type device of the invention comprises two flanks, connecting the axial ends of the respective structures of revolution respectively radially outer and radially inner and axially delimiting the inner annular space, so that the inner annular space constitutes a closed cavity that can be pressurized by an inflation gas.
• Flanks according to their design and, in particular, according to their structural rigidity, may participate more or less in the port of the applied load.
• the flanks generally comprise at least one elastomeric material and may optionally include a reinforcement frame.
• 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 flanks 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 pressure is at least 0.5 bar, preferably at least 1 bar.
• 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 average surface density D of the carrier elements per unit area of radially outer revolution structure is advantageously at least 3 * (S / SE) * Z / (A * F r ).
• a higher average surface density of carrier elements improves the homogenization of pressures in the ground contact area and ensures a higher safety factor with respect to the applied load and with respect to the endurance.
• the average surface density D of the carrier elements per unit area of radially outer revolution structure is even more advantageously at least equal to 6 * (S / SE) * Z / (A * F r ).
• An even higher average surface density of carrier elements further enhances the homogenization of pressures in the ground contact area and further increases the safety factor with respect to the applied load and vis-à-vis - endurance.
• the average surface density D of the carrier elements per unit area of radially outer revolution structure, expressed in 1 / m 2 is advantageously at least equal to 5000.
• the connecting surface SE of the radially outer fabric with the radially inner face of the radially outer revolution structure is equal to the surface S of the radially inner face of the radially outer revolution structure, that is to say that the radially outer fabric completely covers the radially inner face of the radially outer revolution structure.
• the average surface density D of the minimum carrier elements is equal to ZI (A * F r ).
• the radially outer fabric is a halftone fabric comprising intersections of a first family of son, parallel to each other and forming, with a circumferential direction XX 'of the pneumatic type device. , an angle A E at least equal to 10 ° and at most equal to 45 °, and a second family of son, parallel to each other, the respective son of the two families of son of the radially outer fabric being symmetrical with respect to a equatorial plane XZ of the pneumatic device.
• the radially inner fabric is a woven fabric comprising intersections of a first family of son, parallel to each other and forming, with a circumferential direction XX 'of the pneumatic type device , An angle Ai substantially equal to 45 °, and a second family of son, parallel to each other, the respective son of the two son families of the radially inner fabric being symmetrical with respect to an equatorial plane XZ of the pneumatic device.
• a woven fabric during its manufacture, is usually constituted by intersections of a first family of parallel son together, called weft son, and a second family of son parallel to each other, called warp threads, perpendicular to the weft threads.
• the mechanical characteristics of such a fabric such as its stiffness in extension and its tensile strength in tension, in the direction of the weft or that of the chain, depend on the characteristics of the elementary threads, such as, for elementary threads of textile , the title, expressed in tex or g / 1000 m, the tenacity, expressed in cN / tex, and the standard contraction, expressed in%, these elementary son being distributed according to a given density, expressed in number of son / dm. All these characteristics are a function of the material constituting the threads and the design of these threads.
• a screen fabric as described above is, at first, linked to the ends of the carrier elements as a constituent element of the sandwich structure.
• the sandwich structure thus comprises at least one woven fabric intended to be bonded, generally by bonding or vulcanization, or to the radially inner face of the radially outer revolution structure, to become the radially outer woven fabric, either to the radially outer face of the radially inner revolution structure, to become the radially inner halftone fabric.
• the woven fabric is intended to become the radially outer woven fabric or the radially inner woven fabric, it is placed on a cylindrical surface, so that the warp and weft threads, perpendicular to each other, initially form, with the circumferential direction XX 'of the pneumatic type device, an angle substantially equal to 45 °.
• the pneumatic type device After assembly of the sandwich structure in the pneumatic type device, the pneumatic type device is shaped, that is to say the diameter of the radially outer revolution structure increases while the diameter of the revolution structure. radially inner remains constant. If the woven fabric is radially outside, its distance radial with respect to the axis of revolution of the pneumatic-type device increases significantly during conformation, its circumferential length increases and the angle formed by the warp and weft yarns, with the circumferential direction XX ' the pneumatic type device, initially equal to 45 °, decreases and becomes at least equal to 10 ° and at most equal to 45 °, after shaping.
• the woven fabric is radially interior, its radial distance with respect to the axis of revolution of the pneumatic device remains almost constant during the conformation, its circumferential length does not vary or little and the angle formed by the chain and the weft son, with the circumferential direction XX 'of the pneumatic type device, initially equal to 45 °, remains substantially equal to 45 °, after shaping.
• any carrier element comprises at least one radially inner end portion integrated in the radially outer halftone fabric and constituted by interlacing with respect to at least one yarn.
• the load-bearing elements have at least one radially inner end portion integrated in the radially inner halftone fabric and constituted by intersections with respect to at least one yarn.
• the sandwich structure comprises two respectively radially outer and radially inner fabric raster and wire-carrying elements constituted by wires, the end portions of which are integrated into each fabric respectively radially. outside and radially inside, parallel to one of the families of threads of the fabric.
• Such a structure has the advantage of being able to be manufactured in a single weaving step.
• a plurality of wire carrying elements are constituted by a continuous wire passing alternately in each respectively radially outer and radially inner fabric.
• the carrier structure, the radially outer fabric and the radially inner fabric constituting the sandwich structure comprise a polymeric material, such as an aliphatic polyamide, an aromatic polyamide or a polyester, or a metallic material, such as steel, or a glass or carbon type material or any combination of the above materials.
• a polymeric material such as an aliphatic polyamide, an aromatic polyamide or a polyester
• a metallic material such as steel, or a glass or carbon type material or any combination of the above materials.
• 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.
• the carrier structure, the radially outer fabric and the radially inner fabric, constituting the sandwich structure comprise a polyester, such as a 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.
• the carrier structure, the radially outer fabric and the radially inner fabric, constituting the sandwich structure comprise an aliphatic polyamide, such as nylon.
• Nylon is also commonly used in the tire field for the same reasons as PET.
• the sandwich structure consisting of the supporting structure, the radially outer fabric and the radially inner fabric, comprises a single material.
• a single material makes it possible, on the one hand, to standardize the manufacture of the material and, on the other hand, to simplify the manufacture of the sandwich structure.
• the sandwich structure constituted by the supporting structure, the radially outer fabric and the radially inner fabric, is formed by a helical winding of a strip on the radially outer face of the sandwich structure.
• radially inner fabric so as to constitute a juxtaposition of contiguous or non-contiguous strip portions.
• Strip means a sandwich structure element having a limited axial width, at most equal to 0.3 times the axial width of the overall sandwich structure, and of great length, so that the strip may be stored in form of roll.
• Such a strip is thus unwound according to a helix, having as an axis of revolution the axis of revolution of the pneumatic type device, on the radially inner revolution structure which acts as a laying shape.
• the number of helical winding turns of the strip is determined by the axial width of the targeted sandwich structure and the density of the carrier elements constituting the strips.
• the laying of the strip may be contiguous, that is to say that the strip portions are in contact two by two by their axial ends, or non-contiguous, that is to say that the axial ends of the strip portions are spaced apart from a predetermined space.
• the advantage of striping is the absence of overlapping areas, or welds, in the circumferential direction, between strip portions at the end of winding.
• the bonding surface S E of the radially outer fabric with the radially inner face of the radially outer revolution structure is the sum of the bonding surfaces of the strip elements juxtaposed.
• the sandwich structure constituted by the supporting structure, the radially outer fabric and the radially inner fabric, is constituted by a cylindrical winding around the axis of revolution YY ' pneumatic type device, a single element having an axial width equal to the axial width of the sandwich structure.
• the sandwich structure is deposited in a single cylindrical winding turn on the radially inner revolution structure which acts as a laying shape.
• the angle B formed by a carrier element, with a radial direction ZZ 'of the pneumatic type device is substantially zero, for a carrier element located in the equatorial plane XZ of the pneumatic type device, and is as much higher, in absolute value, that a carrier element is distant from the equatorial plane XZ.
• the sidewalls are not directly related to the sandwich structure, preferably are not directly connected to the carrier elements. 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.
• the load-bearing elements positioned at the axial ends of the support structure may possibly be connected to or integrated with the sidewalls.
• each flank having a curvilinear length L F is advantageously at least equal to 1.05 times, preferably 1.15 times the average radial height 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 characteristic of length flank ensures that the flank deformation will not disturb the meridian flattening of the pneumatic type device due to a too small 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 further 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 on 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 sandwich structure constituted by the supporting structure constituted by wire elements connecting two tissues, intended to be respectively secured to the radially inner revolution structure and to the radially outer revolution structure, may be manufactured by any method known composite sandwich structure manufacturing, particularly by weaving.
• the pneumatic type device can be manufactured according to the following method 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.
• - Figure 1 perspective view and partial section of a pneumatic type device according to the invention.
• FIG. 2A view of a circumferential section of a pneumatic type device according to the invention, in the initial state.
• - Figure 2B view of a circumferential cut of a pneumatic type device according to the invention, in the crushed 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 one-dimensional carrying elements.
• 3B perspective view of a one-dimensional carrier element.
• - Figure 4 perspective view in partial section of a pneumatic type device according to a preferred embodiment of the invention, with a sandwich structure formed by helical winding of a strip.
• - Figure 5 front view with partial section of the tread of a pneumatic type device according to a preferred embodiment of the invention, with a sandwich structure formed by helical winding of a strip.
• - Figure 6A meridian sectional view of a sandwich structure comprising two screen fabrics and a supporting structure.
• - Figure 6B top view of a sandwich structure comprising two screen fabrics and a support structure.
• FIG. 7 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 and a reference tire of the state of the art.
• FIG. 8 comparative standard curves of the evolution of the rigidity of drift as a function of the load applied for a pneumatic type device according to the invention 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 having a face radially inner 23 and two axial ends 24, a radially inner structure of revolution 3 having a radially outer face 33 and two axial ends 34, an inner annular space 5, a sandwich structure 8 comprising a carrier structure 6 and two respectively radially outer fabric 71 and radially inner 72, and two sidewalls 9.
• the radially outer revolution structure 2 has an axis of revolution which is the axis of rotation YY 'of the pneumatic type device and is intended to come into contact with a ground via 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 61, extending continuously from of the radially inner face 23 of the structure of radially outer revolution 2 to the radially outer face 33 of the radially inner revolution structure 3, two to two independent in the inner annular space 5.
• the two radially outermost fabric 71 and radially inner 72 of the sandwich structure 8 are connected and most often glued respectively to the radially inner face 23 of the radially outer revolution structure 2 and to the radially outer face 33 of the radially inner revolution structure 3.
• the pneumatic type device 1 comprises two sidewalls 9 connecting the axial ends (24, 34) of 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 an inflation gas.
• 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 61, 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. In this initial state, the carrier elements 61 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.
• FIG. 2B shows a circumferential section of a pneumatic type device 1 according to the invention, mounted on an assembly 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 carrying elements 61 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 load-bearing elements 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. As described for FIG. 1, the pneumatic type device 1 comprises a structure of revolution radially.
• the pneumatic type device 1 subjected to a nominal radial load Z, is in contact with a ground plane by a contact surface A.
• FIG. 3B shows a linear or one-dimensional carrier element 61 having a circular mean section Sp, defined by a smaller characteristic dimension E and a larger characteristic dimension L, all of which are equal, in the example presented, to the diameter of the circle. , and characterized by its form ratio K equal to L / E, thus equal to 1 in the present case.
• the smallest characteristic dimension E of the mean section Sp of the carrier element 61 is at most equal to 0.02 times the average radial height H of the inner annular space 5.
• the carrier member 61 has a length Lp at least equal to the average height H of the inner annular space 5.
• FIG. 4 shows a perspective view in partial section of a pneumatic type device 1 according to a preferred embodiment of the invention in which the sandwich structure 8, constituted by the carrying structure 6, the fabric radially. outside 71 and the radially inner fabric 72, is constituted by a helical winding of a strip 81 on the radially outer face 33 of the radially inner revolution structure 3, so as to form a juxtaposition of strip portions.
• the other elements referenced in FIG. 4 are identical to those of FIG. 1.
• FIG. 5 shows a front view with partial section of the tread of a pneumatic type device 1 according to the preferred embodiment. of the invention, presented in perspective with partial section in Figure 4.
• Figure 5 is a view with partial removal of the tread 2 revealing the helical winding of a strip 81 on the radially outer face 33 of the radially inner revolution structure 3, so as to form a juxtaposition of strip portions.
• This helical winding of a strip 81 constitutes the sandwich structure 8, constituted by the supporting structure 6, the radially outer fabric 71 and the radially inner fabric 72.
• FIG. 6A is a meridian sectional view of a sandwich structure 8 comprising two screen fabrics (71, 72) and a supporting structure 6.
• the two screen fabrics (71, 72) are intended to become the respectively radially-woven fabrics. outside and radially inside, after integration into the pneumatic type device.
• Each woven fabric (71, 72) is constituted by perpendicular intersections of a first family of threads (711, 721), called weft threads, and a second family of threads (712, 722), called warp threads. .
• the carrier elements 61 of the carrier structure 6 consist of continuous filaments connecting the two screen fabrics (71, 72) and comprising portions (611, 612) interwoven with the respective weft threads (711, 721) of said fabrics. framed (71, 72), parallel to the warp son (712, 722) and constituting the ends of the carrier elements 61 integrated in each fabric.
• the advantage of such a design is to be able to weave the sandwich structure in one step.
• FIG. 6B shows a top view of a sandwich structure 8 comprising two screen fabrics (71, 72) and a supporting structure 6.
• the screen fabric 71 shown is formed by perpendicular intersections of the first family of threads 711. , called weft threads, and the second son family 712, called warp threads.
• FIG. 4B shows portions of wires 61 1, intersecting with the weft threads 711, parallel to the warp threads 712 and constituting ends of the carrying elements 61 integrated in the woven fabric 71.
• FIG. 1 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. 1 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. 8 shows two comparative standard curves of the evolution of the drift rigidity, expressed in N / °, as a function of the applied load, expressed in N, for a pneumatic type device according to the invention 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. 5 and 6 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 sandwich structure constituted by the supporting structure, the radially outer fabric and the radially inner fabric is made of polyethylene terephthalate (PET).
• Each holder element wired to the support structure polyethylene terephthalate (PET) has an average section Sp equal to 7 * 10 "8 m 2 and a breaking stress F r / Sp equal to 470 MPa.
• the surface density D elements carriers per unit area of radially outer rotational structure is equal to 85000 threads / 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 600 daN .
• the invention describes a carrier structure constituted by identical filament-carrying elements, both in shape-K relationship, in structure and in material, the invention may be extended to a support structure that may be constituted by any combination of load-bearing elements, such as, for example and non-exhaustively:
• filament-carrying elements having K-form ratios and / or different structures and / or materials

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• Tires In General (AREA)

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• 2016
  • 2016-07-29 FR FR1657339A patent/FR3054485A1/fr not_active Withdrawn
• 2017
  • 2017-07-27 WO PCT/FR2017/052098 patent/WO2018020164A1/fr unknown
  • 2017-07-27 EP EP17754413.7A patent/EP3490814A1/de not_active Withdrawn

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