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
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/1821—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers comprising discrete fibres or filaments
• • 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
  • B60C9/0238—Carcasses characterised by special physical properties of the carcass ply
• • 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
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C9/2003—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel characterised by the materials of the belt cords
  • B60C9/2006—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel characterised by the materials of the belt cords consisting of steel cord plies only
• • 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
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C9/22—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre
• • 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
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C2009/2041—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel with an interrupted belt ply, e.g. using two or more portions of the same ply
• • 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
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C9/22—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre
  • B60C2009/2214—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre characterised by the materials of the zero degree ply cords
• • 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
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C9/22—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre
  • B60C2009/2252—Physical properties or dimension of the zero degree ply cords
  • B60C2009/2261—Modulus of the cords
• • 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
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C9/22—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre
  • B60C2009/2252—Physical properties or dimension of the zero degree ply cords
  • B60C2009/2295—Physical properties or dimension of the zero degree ply cords with different cords in the same layer
• • 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
  • B60C2200/00—Tyres specially adapted for particular applications
  • B60C2200/06—Tyres specially adapted for particular applications for heavy duty vehicles
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T152/00—Resilient tires and wheels
  • Y10T152/10—Tires, resilient
  • Y10T152/10495—Pneumatic tire or inner tube
  • Y10T152/10513—Tire reinforcement material characterized by short length fibers or the like
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T152/00—Resilient tires and wheels
  • Y10T152/10—Tires, resilient
  • Y10T152/10495—Pneumatic tire or inner tube
  • Y10T152/10765—Characterized by belt or breaker structure
  • Y10T152/10783—Reinforcing plies made up from wound narrow ribbons

Definitions

• the present invention relates to a tire, radial carcass reinforcement and more particularly to a tire intended to equip vehicles carrying heavy loads and rolling at a high speed, such as, for example, trucks, tractors, trailers or road buses.
• the carcass reinforcement is anchored on both sides in the bead zone and is radially surmounted by a crown reinforcement consisting of at least two layers, superimposed and formed of son or parallel cables in each layer and crossed from one layer to the next in making with the circumferential direction angles between 10 ° and 45 °.
• Said working layers, forming the working armature can still be covered with at least one so-called protective layer and formed of advantageously metallic and extensible reinforcing elements, called elastic elements.
• It may also comprise a layer of low extensibility wires or metal cables forming with the circumferential direction an angle of between 45 ° and 90 °, this so-called triangulation ply being radially located between the carcass reinforcement and the first ply of plywood.
• so-called working top formed of parallel wires or cables having angles at most equal to 45 ° in absolute value.
• the triangulation ply forms with at least said working ply a triangulated reinforcement, which presents, under the different stresses it undergoes, few deformations, the triangulation ply having the essential role of taking up the transverse compression forces of which the object all the reinforcing elements in the area of the crown of the tire.
• a single protective layer is usually present and its protective elements are, in most cases, oriented in the same direction and with the same angle in absolute value that those reinforcing elements of the radially outermost and therefore radially adjacent working layer.
• the presence of two layers of protection is advantageous, the reinforcing elements being crossed from one layer to the next and the reinforcement elements of the layer of radially inner protection being crossed with the inextensible reinforcing elements of the radially outer working layer and adjacent to said radially inner protective layer.
• Cables are said to be inextensible when said cables have under a tensile force equal to 10% of the breaking force a relative elongation at most equal to 0.2%.
• Cables are said to be elastic when said cables have under a tensile force equal to the breaking load a relative elongation of at least 3% with a maximum tangent modulus of less than 150 GPa.
• Circumferential reinforcing elements are reinforcing elements which make angles with the circumferential direction in the range + 8 °, - 8 ° around 0 °.
• the circumferential direction of the tire is the direction corresponding to the periphery of the tire and defined by the rolling direction of the tire.
• the transverse or axial direction of the tire is parallel to the axis of rotation of the tire.
• the radial direction is a direction intersecting the axis of rotation of the tire and perpendicular thereto.
• the axis of rotation of the tire is the axis around which it rotates in normal use.
• a radial or meridian plane is a plane which contains the axis of rotation of the tire.
• the circumferential mid-plane, or equatorial plane is a plane perpendicular to the axis of rotation of the tire and which divides the tire into two halves.
• the measurements of force at break (maximum load in N), tensile strength (in MPa) and elongation at break (total elongation in%) are performed in tension according to ISO 6892 of 1984.
• Patent FR 1 389 428 to improve the resistance to degradation of rubber compounds located in the vicinity of the crown reinforcement edges, recommends the use, in combination with a tread of low hysteresis, of a rubber profile covering at least the sides and the marginal edges of the crown reinforcement and consisting of a rubber mixture with low hysteresis.
• Patent FR 2 222 232 to avoid separations between plies of crown reinforcement, teaches to coat the ends of the frame in a rubber mattress, the Shore A hardness is different from that of the strip. rolling overlying said armature, and greater than the Shore A hardness of the rubber mix profile disposed between the edges of crown reinforcement plies and carcass reinforcement.
• the French application FR 2 728 510 proposes to have, on the one hand between the carcass reinforcement and the crown reinforcement working ply, radially closest to the axis of rotation, an axially continuous ply. formed of inextensible metal ropes forming an angle of at least 60 ° with the circumferential direction, the axial width of which is at least equal to the axial width of the shortest working crown ply, and secondly between the two working crown plies an additional ply formed of metal elements, oriented substantially parallel to the circumferential direction.
• the layer of circumferential reinforcing elements is usually constituted by at least one wire rope wound to form a turn whose laying angle relative to the circumferential direction is less than 8 °.
• An object of the invention is to provide tires for vehicles "Heavy-Duty", whose endurance and wear performance are retained for road use and whose wear performance is improved for uses on unpaved ground
• a radial carcass reinforcement tire comprising a crown reinforcement formed of at least two working crown layers of inextensible reinforcing elements, crossed with a layer at the same time. other making with the circumferential direction angles between 10 ° and 45 °, itself capped radially of a tread, said tread being joined to two beads by means of two sidewalls, the armature of apex comprising at least one layer of circumferential metal reinforcing elements, said layer of circumferential reinforcing elements consisting of at least one central part and two axially outer parts, the reinforcing elements of the central part of said at least one layer of circumferential reinforcing elements being reinforcing elements cut so as to form sections, the length of the sections less than 550 mm, the distance between the ends of two consecutive sections being greater than 25 mm, the length of the sections being between 1.1 and 13 times the distance between the ends of two consecutive sections and the reinforcement elements of the two parts.
• axially outer being continuous.
• the tire thus defined according to the invention retains satisfactory properties in rolling at high speeds on roads and also has performance in terms of wear resistance and more specifically in terms of resistance to aggressions significantly improved compared to known tires.
• the inventors have indeed been able to highlight that the aggressions that occur on non-bituminous lands essentially concern the central portion of the tread of the tire, the latter being it seems always the most exposed.
• the tire as defined according to the invention leads to a relaxation in the radial direction of the axially central portion of the tire due in particular to the lower circumferential stiffness of the central zone of the tire due to the presence of reinforcing elements. circumferential cut.
• This relaxation leads, in view of the results obtained, to an absorption of the aggressions of the tread from obstacles such as pebbles present on the floors on which the vehicle is traveling.
• the inventors have yet been able to highlight that the decrease in the rigidity of the central zone of the tire makes it possible to modify the shape of the contact area of the tire with the ground and thus further improve the wear performance. on bituminous ground.
• the crown reinforcement according to the invention promotes an almost rectangular footprint by limiting the concave appearance in the axial direction of said footprint.
• An advantageous embodiment of the invention provides that the length of the sections is less than 300 mm and that the length of the sections is less than 6.5 times the distance between the ends of two consecutive sections.
• the length of the sections is less than 260 mm and the length of the sections is less than 3.5 times the distance between the ends of two consecutive sections.
• the distance between the ends of two sections is greater than 35 mm.
• the length of the sections is greater than 95 mm.
• the distance between the ends of two consecutive sections is less than 175 mm.
• the stiffness of the reinforcing elements of the central portion must in particular be sufficient to ensure a satisfactory hooping of the tire at this portion. central to withstand the constraints imposed especially during inflation or rolling at high speeds and limit the circumferential expansion of the crown reinforcement.
• the layer of circumferential reinforcing elements has an axial width greater than 0.5xS.
• S is the maximum axial width of the tire, when the latter is mounted on its service rim and inflated to its recommended pressure.
• the axial widths of the reinforcing element layers are measured on a cross section of a tire, the tire is therefore in a non-inflated state.
• the axial width of the central portion of the layer of circumferential reinforcing elements is greater than 0.15xS and less than 0.5xS.
• the axial width of each of the axially outer portions of the layer of circumferential reinforcing elements is less than 0.45xS.
• transition zones are advantageously provided between the central portion and the axially outer portions such that said transition zones comprise at most one metal reinforcing element, the width, measured according to the axial direction, said transition zones being at least equal to 1.5 mm.
• transition zones will notably make it possible to limit the appearance of overvoltage zones in the cable axially the innermost of the parts axially. external surfaces of the layer of circumferential reinforcing elements in the areas facing the ends of the axially outermost portions of the central portion.
• the width, measured along the axial direction, of said transition zones is at most equal to 7 mm.
• the transition zones comprise a metal reinforcing element, the latter has an angle with the circumferential direction advantageously between 0.2 and 4 °.
• the lateral edges of these transition zones are spaced from the axial ends, at the rolling surface, of said rib by a distance measured in the axial direction of at least 4 mm.
• the axial ends are defined by the intersection of the slope of the groove formed by the rib with the tangent to the upper face of the rib.
• transition zones are advantageously provided between the central portion and the axially outer portions such that said transition zones have intermediate circumferential stiffnesses between those of the central portion and axially portions. exterior.
• transition zones preferably have a small axial width and provide a gradual transition between the circumferential rigidities of the central portion and the axially outer portions.
• the width of said transition zone is advantageously between 1.25 and 3.75 times the pitch of the circumferential reinforcement elements in the axially outer parts.
• the pitch in a portion of the layer of circumferential reinforcing elements is the distance between two consecutive reinforcing elements. It is measured between the longitudinal axes of said reinforcing elements in a direction perpendicular to at least one of said longitudinal axes. It is therefore measured in a substantially axial direction.
• the stiffness gradient from the axially outer portions to the central portion is advantageously obtained with transition zones consisting of circumferential reinforcing elements cut so as to form sections whose length is greater than that of the sections of the central part and / or with a distance between the ends of two consecutive sections which is less than that between two sections of the central part.
• the circumferential length of the sections decreases from the axially outer edge of a transition zone to its axially inner edge.
• the distance between the ends of two consecutive sections increases from the axially outer edge of a transition zone to its axially inner edge.
• a decrease in the circumferential length of the sections is combined with an increase in the distance between the ends of two consecutive sections, from the axially outer edge of a transition zone to its axially inner edge.
• the invention further provides the combination of two successive transition zones provided between the central portion and the axially outer portions, the first, adjacent to an axially outer portion, comprising at most one metal reinforcing element as described above. and the second, adjacent to the central portion, having intermediate circumferential stiffnesses between those of the central portion and axially outer portions, in particular obtained by a decrease in the circumferential length of the sections and / or an increase in the distance between the ends of the central portion. two consecutive sections from the axially outer edge of said second transition zone to its axially inner edge.
• Other variants further provide that the circumferential reinforcing elements are implemented with a different pitch in the central portion and in the axially outer portions.
• the pitch is advantageously greater in said central portion. Its value advantageously does not exceed 1.5 times the value of the pitch in the axially outer parts, and more preferably 1.25 times the value of the pitch in the axially outer parts.
• the pitch of the circumferential reinforcement elements in the transition zone is at a value between that of the axially outer parts and that of the central part.
• a preferred embodiment of the invention provides that two consecutive circumferential reinforcing elements, or axially adjacent, of the central part, and possibly transition zones, which consist of cut reinforcing elements forming sections, do not have zones of cuts axially facing one another. More precisely, the zones of cuts between sections are preferably not axially adjacent and are therefore circumferentially offset.
• the ends of two adjacent sections are separated from each other in the longitudinal direction by a distance greater than 0.1 times the length of the section whose length measured along the longitudinal direction is the smallest.
• the invention further advantageously provides that at least one layer constituting the vertex architecture is present radially under the "rib", or sculpture of longitudinal main orientation, axially the outermost.
• This embodiment allows, as previously stated, to reinforce the rigidity of said sculpture.
• the layer of circumferential reinforcing elements is present radially under the "rib” or sculpture of longitudinal principal orientation, axially the outermost.
• at least two working crown layers have different axial widths, the difference between the axial width of the axially widest working crown layer and the axial width of the layer. axially the least wide axially working vertex being between 10 and 30 mm.
• the axially widest axially working crown layer is radially inside the other working crown layers.
• the layer of circumferential reinforcing elements is radially arranged between two working crown layers.
• the axial widths of the working crown layers radially adjacent to the layer of circumferential reinforcing elements are greater than the axial width of said layer of circumferential reinforcing elements and preferably, said working crown layers adjacent to the layer of circumferential reinforcing elements are on either side of the equatorial plane and in the immediate axial extension of the layer of circumferential reinforcing elements coupled over an axial width, to be subsequently decoupled by rubber mixing profiles at least over the remainder of the width common to said two working layers.
• coupled layers are layers whose respective reinforcing elements are radially separated by at most 1.5 mm, said rubber thickness being measured radially between the respectively upper and lower generatrices of said elements. reinforcement.
• the thickness of the decoupling profiles between working plies, measured at the ends of the least wide working ply, will be at least two millimeters, and preferably greater than 2.5 mm.
• the circumferential reinforcing elements of the central portion of at least one layer of circumferential reinforcing elements are inextensible metal reinforcing elements. This embodiment of the invention is particularly interesting from an economic point of view, this type of reinforcing elements being inexpensive.
• the circumferential reinforcing elements of the central portion of at least one layer of circumferential reinforcing elements are elastic metal reinforcing elements.
• Such an alternative embodiment of the invention may have the advantage of simplifying the production of the layer of circumferential reinforcing elements, the same reinforcing elements being able to be used for the three axial parts of said layer of circumferential reinforcing elements. .
• a system for cutting the reinforcing elements being for example made operational only for the central part during the installation of the circumferential reinforcing elements.
• At least the reinforcing elements of the two axially outer portions of at least one layer of circumferential reinforcing elements are metal reinforcing elements having a secant modulus at 0, 7% elongation between 10 and 120 GPa and a maximum tangent modulus less than 150 GPa.
• the secant modulus of the reinforcing elements at 0.7% elongation is less than 100 GPa and greater than 20 GPa, preferably between 30 and 90 GPa and more preferably less than 80 GPa. .
• the maximum tangent modulus of the reinforcing elements is less than 130 GPa and more preferably less than 120 GPa.
• the modules expressed above are measured on a tensile stress curve as a function of the elongation determined with a preload of 20 MPa brought back to the metal section of the reinforcing element, the tensile stress corresponding to a measured voltage brought back to the metal section of the reinforcing element.
• the modules of the same reinforcing elements can be measured on a tensile stress curve as a function of the elongation determined with a preload of 10 MPa reduced to the overall section of the reinforcing element, the tensile stress corresponding to a measured voltage brought back to the overall section of the reinforcing element.
• the overall section of the reinforcing element is the section of a composite element made of metal and rubber, the latter having in particular penetrated the reinforcing element during the baking phase of the tire.
• the reinforcing elements of the axially outer portions and the central portion of at least one layer of circumferential reinforcement elements are metal reinforcing elements having a secant modulus at 0.7% elongation between 5 and 60 GPa and a maximum tangent modulus of less than 75 GPa.
• the secant modulus of the reinforcing elements at 0.7% elongation is less than 50 Gpa and greater than 10 GPa, preferably between 15 and 45 GPa and more preferably less than 40 GPa. .
• the maximum tangent modulus of the reinforcing elements is less than 65 GPa and more preferably less than 60 GPa.
• At least the reinforcing elements of the two axially outer portions of at least one layer of circumferential reinforcing elements are metal reinforcing elements having a tensile stress curve as a function of the relative elongation with low slopes for low elongations and a substantially constant slope and strong for higher elongations.
• Such reinforcing elements of the additional ply are usually referred to as "bi-module" elements.
• the substantially constant and strong slope appears from a relative elongation of between 0.1% and 0.5%.
• Reinforcement elements more particularly adapted to the production of at least one layer of circumferential reinforcing elements according to the invention are, for example, assemblies of formula 21.23, the construction of which is 3x (0.26 + 6x0.23).
• 4.4 / 6.6 SS; this strand cable consists of 21 elementary wires of formula 3 x (1 + 6), with 3 twisted strands each consisting of 7 wires, a wire forming a central core of diameter equal to 26/100 mm and 6 coiled wires of diameter equal to 23/100 mm.
• Such a cable has a secant module at 0.7% equal to 45 GPa and a maximum tangent modulus equal to 98 GPa, measured on a tensile stress curve as a function of the elongation determined with a preload of 20 MPa brought back to the section. of the reinforcing element, the tensile stress corresponding to a measured voltage brought back to the metal section of the reinforcing element.
• this cable of formula 21.23 On a tensile stress curve as a function of the elongation determined with a preload of 10 MPa brought back to the overall section of the reinforcing element, the tensile stress corresponding to a measured tension brought back to the overall section of the element of reinforcement, this cable of formula 21.23 has a secant module at 0.7% equal to 23 GPa and a maximum tangent modulus equal to 49 GPa.
• reinforcing elements is an assembly of formula 21.28, whose construction is 3x (0.32 + 6x0.28) 6.2 / 9.3 SS.
• This cable has a secant modulus at 0.7%> equal to 56 GPa and a maximum tangent modulus equal to 102 GPa, measured on a tensile stress curve as a function of the elongation determined with a preload of 20 MPa brought to the section. of the reinforcing element, the tensile stress corresponding to a measured voltage brought back to the metal section of the reinforcing element.
• this cable of formula 21.28 On a tensile stress curve as a function of the elongation determined with a preload of 10 MPa brought back to the overall section of the reinforcing element, the tensile stress corresponding to a measured tension brought back to the overall section of the element of reinforcement, this cable of formula 21.28 has a secant module at 0.7% equal to 27 GPa and a maximum tangent modulus equal to 49 GPa.
• the metal elements are preferably steel cables.
• the invention further advantageously provides for reducing the tension stresses acting on the axially outermost circumferential elements that the angle formed with the circumferential direction by the reinforcement elements of the working crown layers is less than 30 ° and preferably less than 25 °.
• the working crown layers comprise reinforcing elements, crossed from one sheet to the other, making with the circumferential direction variable angles in the axial direction, said angles being higher on the axially outer edges of the reinforcing element layers with respect to the angles of said elements measured at the circumferential mid-plane.
• a preferred embodiment of the invention further provides that the crown reinforcement is completed radially on the outside by at least one additional layer, called protective layer, of so-called elastic reinforcing elements, oriented with respect to the direction circumferential with an angle between 10 ° and 45 ° and in the same direction as the angle formed by the inextensible elements of the working layer which is radially adjacent thereto.
• protective layer of so-called elastic reinforcing elements
• the protective layer may have an axial width smaller than the axial width of the least wide working layer.
• Said protective layer may also have an axial width greater than the axial width of the narrower working layer, such that it covers the edges of the narrower working layer and, in the case of the radially upper layer, being the smallest, as coupled, in the axial extension of the additional reinforcement, with the widest working crown layer over an axial width, to be subsequently, axially outside, decoupled from said widest working layer with profiles at least 2 mm thick.
• the protective layer formed of elastic reinforcing elements may, in the case mentioned above, be on the one hand possibly decoupled from the edges of said least-wide working layer by profiles of thickness substantially less than the thickness of the profiles separating the edges of the two working layers, and have on the other hand an axial width smaller than or greater than the axial width of the widest vertex layer.
• the crown reinforcement may be further completed, radially inwardly between the carcass reinforcement and the nearest radially inner working layer. of said carcass reinforcement, by a triangulation layer of steel non-extensible reinforcing elements making, with the circumferential direction, an angle greater than 45 ° and in the same direction as that of the angle formed by the reinforcing elements of the layer radially closest to the carcass reinforcement.
• FIGS. 1 to 5 represent: figurel, a meridian view of a diagram of FIG. 2, a schematic representation of a layer of circumferential reinforcement elements of the tire of FIG. 1, FIG. 3, a schematic representation of a layer of circumferential reinforcing elements according to a second embodiment of the invention, FIG. 4, a schematic representation of a layer of circumferential reinforcing elements according to a third embodiment of the invention, FIG. 5, a meridian view of a diagram of a tire according to an alternative embodiment of the invention.
• the figures are not shown in scale to simplify understanding.
• the figures represent only a half-view of a tire which extends symmetrically with respect to the axis XX 'which represents the circumferential median plane, or equatorial plane, of a tire.
• the tire 1 of dimension 455/45 R 22.5, has an aspect ratio H / S equal to 0.45, H being the height of the tire 1 on its mounting rim and S its width.
• Said tire 1 comprises a radial carcass reinforcement 2 anchored in two beads, not shown in FIG. 1.
• the carcass reinforcement is formed of a single layer of metal cables.
• This carcass reinforcement 2 is fretted by a crown reinforcement 4, formed radially from the inside to the outside: of a layer of reinforcing elements 45, called triangulation, formed of unstretchable, continuous, inextensible metal cables 9.28 across the entire width of the web, oriented at an angle equal to 50 °, a first working layer 41 formed of unstretchable 11.35 inextensible metal cables, continuous over the entire width of the web, oriented by an equal angle at 18 °, a layer of circumferential reinforcing elements 42 formed of 21x28 steel cables, of "bi-module" type, consisting of three parts including two axially outer portions 421 and a central portion 422, of a second working layer 43 formed of unstretchable 11.35 inextensible metal ropes, continuous over the entire width of the ply, oriented at an angle equal to 18 ° and crossed to the metal cables of the layer 41, of a layer e of protection 44 formed of elastic metal cables 18x23, oriented at an
• the crown reinforcement is itself capped with a tread 6.
• the maximum axial width S of the tire is equal to 458 mm.
• the axial width L 45 of the triangulation layer 45 is equal to 382 mm.
• the axial width L of the first working layer 41 is equal to 404 mm.
• the axial width L 43 of the second working layer 43 is equal to 380 mm.
• the difference between the widths L and L 43 is equal to 24 mm.
• the axially outer portions 421 have a width L 421 equal to 61 mm and therefore less than 45% of S.
• the width of the central portion L 422 is equal to 182 mm.
• the last crown ply 44 called the protection ply, has a width L 44 equal to 338 mm.
• FIG. 2 illustrates a first embodiment of a layer of circumferential reinforcing elements 42 according to the invention, corresponding to FIG. 1.
• this layer 42 consists of a central portion 421 and two axially outer parts 421.
• the circumferential reinforcing elements 5 are deposited with a constant pitch P equal to 2.3 mm over the entire axial width of the layer of circumferential reinforcing elements 42.
• the circumferential reinforcing elements are cut to form sections 6, having a length 1 equal to 101 mm. Two sections are separated by a gap 7 whose distance d measured between the ends of two circumferentially consecutive sections 6 is equal to 65 mm.
• the layer 42 thus produced provides a lower circumferential stiffness in the central portion 422 relative to those of the axially outer portions 421.
• Figure 3 illustrates a second embodiment of a layer of circumferential reinforcing elements 42 according to the invention.
• the layer 42 has two intermediate zones 423 axially located between the central portion 422 and each of the axially outer portions 421.
• the axial width L 423 is equal to 4.5 mm.
• the axial width of the central portion L 422 is equal to 173 mm and the axial widths L 421 of the axially outer portions 421 are equal to 61 mm.
• the length of the sections 6 and the distance of the gaps 7 of the central portion 422 are identical to those of FIG. 2.
• the sections 8 of the intermediate zones 423 have a length 1423 equal to 132 mm and two sections 8 are separated by a gap 9 whose distance d 423 measured between the ends of two circumferentially consecutive sections 8 is equal to 35 mm.
• FIG. 4 illustrates a third embodiment of a layer of circumferential reinforcing elements 42 according to the invention. As in the case of Figure 3, it comprises two intermediate zones 423 axially located between the central portion 422 and each of the axially outer portions 421.
• the axial widths L 423 , L 422 and L 421 are identical to those of FIG. 3.
• the length of the sections 6 and the distance of the gaps 7 from the central portion 422 are identical to those of FIG. 2. and 3.
• the length of the sections 8 and the distance of the intervals 9 of the intermediate zones 423 are identical to those of FIG. 3.
• the pitch P 421 of the circumferential reinforcing elements 5 of the axially outer portions 421 is identical to that of Figure 1 and equal to 2.3 mm.
• the circumferential reinforcing elements cut and forming sections 6 in the central part are laid with a pitch P 422 equal to 2.9 mm.
• This step of greater laying in the central part contributes to reducing the circumferential stiffness of said central portion 422 relative to the axially outer portions 421.
• the laying step of the circumferential reinforcing elements cut and forming sections 8 in the zones Intermediates 423 is equal to 2.5 mm.
• the laying pitch of these intermediate zones 423 is at an intermediate value between those of the axially outer portions 421 and that of the central portion 422. These values contribute to the progressivity of the variation of the circumferential rigidity in the axial direction of the outer layer. circumferential reinforcing elements 42.
• the pitch in the intermediate areas 423 could be at a value identical to that of the pitch of the central portion or to that of the pitch of the axially outer portions, only the lengths of the sections and lengths of the intervals between sections progressively evolving. Still other variants may provide a gradual evolution of the pitch in the intermediate zones associated with either continuous circumferential reinforcement elements as in the axially outer portions 421 or reinforcement elements cut with lengths of sections and intervals between sections identical to those of the central portion 422.
• the tire 1 differs from that shown in FIG. 1 in that the two working layers 41 and 43 are on each side of the equatorial plane.
• the two working layers 41, 43 are separated by a rubber profile, not shown in the figure, the thickness of said profile being increasing by going from the axial end of the coupling area at the end of the least wide working layer.
• Said section advantageously has a width sufficient to radially cover the end of the widest working layer 41, which is, in this case, the working layer radially closest to the carcass reinforcement. Tests were carried out with the tire produced according to the invention in accordance with the representation of FIG. 1 and compared with an identical reference tire, but produced in a usual configuration.
• This reference tire comprises a layer of circumferential reinforcing elements consisting of the same cable, laid with the same pitch and having no part with cut elements to form sections.
• the circumferential stiffness of the layer of reinforcement elements is thus homogeneous over its entire axial width.
• the vehicles are associated with a load per tire of 4000 Kg.
• the layer of circumferential reinforcing elements may for example consist of more than five parts to present variations of circumferential rigidity even more progressive.

Landscapes

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

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=42274266

Family Applications (1)

Country Status (8)

Cited By (4)

Families Citing this family (10)

Citations (6)

Family Cites Families (14)

• 2009
  • 2009-12-10 FR FR0958835A patent/FR2953761B1/fr not_active Expired - Fee Related
• 2010
  • 2010-12-09 CN CN201080055447.9A patent/CN102639339B/zh not_active Expired - Fee Related
  • 2010-12-09 US US13/515,200 patent/US9315073B2/en not_active Expired - Fee Related
  • 2010-12-09 BR BR112012013760A patent/BR112012013760A2/pt not_active IP Right Cessation
  • 2010-12-09 JP JP2012542550A patent/JP5726893B2/ja not_active Expired - Fee Related
  • 2010-12-09 EP EP10807328.9A patent/EP2509801B1/fr not_active Not-in-force
  • 2010-12-09 WO PCT/EP2010/069275 patent/WO2011070111A1/fr active Application Filing
  • 2010-12-09 RU RU2012128814/11A patent/RU2536263C2/ru not_active IP Right Cessation

Patent Citations (6)

Also Published As

Similar Documents

Legal Events