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
  • B60C9/005—Reinforcements made of different materials, e.g. hybrid or composite cords
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/44—Yarns or threads characterised by the purpose for which they are designed
  • D02G3/48—Tyre cords

Definitions

• the invention relates to a reinforcing element, a tire, a semifinished product and a method of manufacturing such a reinforcing element.
• the textile reinforcing elements play an important role in tires, including in high performance tires approved for rolling. at very high speed. To meet the requirements of the tires, the reinforcing elements must have a high breaking strength, a high extension modulus, excellent fatigue endurance and good adhesion to the rubber matrices or other polymers that they are likely to reinforce. .
• reinforcing elements consist of two multifilament strands each consisting of basic textile monofilaments.
• the two strands of monofilaments are wrapped around each other by twisting to form a twist.
• Each strand comprising the textile monofilaments is generally called spun or surtors according to the stage of the manufacturing process.
• the role of the twisting is to adapt the properties of the material to create the transverse cohesion of the reinforcing element, to increase its fatigue strength and also to improve the adhesion with the reinforced matrix.
• the endurance or fatigue resistance (in extension, flexion, compression) and the breaking force of these reinforcing elements are essential. It is known that in general, for a given material, the toughness is all the greater as the twists used are important, but that in return, the force at break in extension (called toughness when it is reduced to the weight unit) decreases inexorably when the torsion increases, which of course is penalizing from the reinforcement point of view.
• the subject of the invention is a reinforcing element comprising a single strand of high modulus textile monofilaments and a single strand of low modulus textile monofilaments wrapped around each other in one direction.
• D3 with a twist R3 the strand of high modulus textile monofilaments having a residual torsion R1 in the direction D1
• the strand of low modulus textile monofilaments having any residual torsion R2 in the direction D2 the residual torsions R1 and R2 being as :
• R1 is substantially non-zero in the case where R2 is substantially zero.
• the reinforcing element according to the invention has an equivalent breaking force and an improved endurance compared to those of a balanced reinforcement element.
• Substantially zero residual torsion means that the residual torsion is strictly less than 2.5% of the torsion R3.
• substantially non-zero residual torsion it is meant that the residual torsion is greater than or equal to 2.5% of the torsion R3.
• Strand of high modulus textile monofilaments means a strand having a so-called final modulus strictly greater than 25 cN / tex.
• a strand of low modulus textile monofilaments means a strand having a final modulus of less than or equal to 25 cN / tex.
• This definition applies both to the unbleached strands, that is to say without glue, that glued strands, that is to say covered with a layer of glue. In the case of glued strands, this definition applies equally to both strands directly from manufacturing and strands from reinforcing elements, whether directly from manufacturing or semi-finished product or tire extracts .
• the final module is measured from a force-elongation curve obtained at 20 ° C. in a known manner using an "INSTRON" traction machine equipped with "4D” type clamping tongs (for breaking force less than 100 daN) or "4E” (for breaking strength at least equal to 100 daN).
• the strand tested is pulled over an initial length of 400 mm for the 4D pliers and 800 mm for the 4E pliers, at a nominal speed of 200 mm / min. All results given are an average of 10 measurements.
• protective twist 100 revolutions per meter with the exception of aramid strands and whose title is greater than or equal to 330 tex and for which the preliminary torsion is equal to 80 turns per meter.
• the final modulus is defined as the slope at the point corresponding to 80% of the breaking force of the force-elongation curve divided by the title of the strand.
• the final modulus is defined as the slope between two points A and B of the force-elongation curve. divided by the titer of the strand, point A corresponding to 40% of the breaking force of the strand and point B corresponding to 60% of the breaking force of the strand.
• Each strand of textile monofilaments comprises a plurality of textile elemental monofilaments, optionally intermingled with each other.
• Each strand comprises between 50 and 2000 monofilaments.
• each residual torsion R1, R2 is determined by detaching the reinforcing element, which allows to obtain R3, then by detaching each strand, which makes it possible to obtain R1 and R2.
• Each twist R1, R2, R3 is determined according to ASTM D 885 / D 885MA January 2010 (paragraph 30), for example using a torsiometer.
• the invention makes it possible to significantly improve the breaking force while maintaining an endurance equivalent to that of a balanced reinforcement element having an R3 torsion. identical to the invention.
• the invention makes it possible to significantly improve the endurance while maintaining a breaking force equivalent to that of a balanced reinforcing element having R3 torsion less than the invention.
• the final modulus of the high modulus textile monofilament strand is greater than or equal to 30 cN / tex, preferably 35 cN / tex and more preferably 40 cN / tex.
• the final modulus of the low modulus textile monofilament strand is less than or equal to 20 cN / tex, preferably 15 cN / tex and more preferably 10 cN / tex.
• the ratio of the end modulus of the high modulus textile monofilament strand to the final modulus of the low modulus textile monofilament strand is greater than or equal to 2, preferably to 5 and more preferably to 7. advantageous embodiment of the invention, this ratio is less than or equal to 15 and preferably to 10.
• textile or textile material in a very general manner, any material of a material other than metal, whether natural as synthetic, capable of being transformed into wire, fiber or film by any suitable processing method.
• a polymer spinning process such as, for example, melt spinning, spinning in solution or gel spinning.
• non-polymeric material for example mineral material such as glass or non-polymeric organic material such as carbon
• the invention is preferably implemented with polymeric materials, both thermoplastic and non-thermoplastic.
• polymeric materials of the thermoplastic or non-thermoplastic type
• celluloses especially rayon, polyvinyl alcohols (abbreviated as "PVA”), polyketones, aramids (aromatic polyamides), aromatic polyesters, polybenzazoles (abbreviated “PBO”), polyimides, polyesters, especially those chosen from PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PBT (polybutylene terephthalate), PBN (polybutylene naphthalate), PPT ( polypropylene terephthalate), PPN (polypropylene naphthalate).
• PET polyethylene terephthalate
• PEN polyethylene naphthalate
• PBT polybutylene terephthalate
• PBN polybutylene naphthalate
• PPT polypropylene terephthalate
• PPN polypropylene naphthalate
• the directions D1, D2 and D3 are identical in the case where R2 is substantially non-zero and the directions D1 and D3 are identical in the case where R2 is substantially zero.
• the twists R1 'and R2' reduces the twists R1 'and R2' to be applied to each strand to the bare minimum.
• the residual torsions R1 and R2 come from the total consumption of the twists R1 'and R2' by the final twist R3 contrary to a method in which the twists R1 'and R2' would be greater (or equal to ) to R3 and in which the residual torsions R1 and R2 come from the surplus torsions R1 'and R2'.
• the high modulus textile monofilaments are aromatic polyamide, preferably aramid.
• aramid monofilament it is well known that it is a monofilament of linear macromolecules formed of aromatic groups linked together by amide bonds, at least 85% of which are directly linked to two aromatic rings. and more particularly poly (p-phenylene terephthalamide) (or PPTA) fibers, manufactured for a long time from optically anisotropic spinning compositions.
• the low modulus monofilaments are made of a material selected from celluloses, polyvinyl alcohols, polyketones, aliphatic polyamides, polyesters, polybenzazoles, polyimides and monofilament mixtures thereof. materials, preferably selected from aliphatic polyamides, polyesters and monofilament mixtures of these materials.
• polyester monofilament it is well known that it is a monofilament of linear macromolecules formed from groups linked together by ester bonds.
• the polyesters are made by polycondensation by esterification between a dicarboxylic acid, or a derivative thereof, and a diol.
• polyethylene terephthalate can be made by polycondensation of terephthalic acid and ethylene glycol.
• nylon monofilament it is well known that it is a monofilament of macromolecules obtained from a synthetic polyamide chain in which the amide bonds are directly bonded to one or more aliphatic group or cycloaliphatic.
• An example of nylon is poly (hexamethylene adipamide).
• twists can be measured and expressed in two different ways, either simply and in a number of revolutions per meter (t / m), that is, and which is more rigorous. when it is desired to compare materials of different natures (densities) and / or titles, at helix angle of the monofilaments or what is equivalent in the form of a torsion factor K.
• R3 ranges from 200 to 450 revolutions per meter, preferably from 250 to 400 revolutions per meter.
• R3 torsion controls the endurance of the reinforcing element.
• the adapted R3 twist depending on the desired endurance, one can choose the adapted R3 twist.
• the higher the R3 twist the better the endurance.
• the reinforcing element has a torsion factor ranging from 130 to 200, preferably from 140 to 190.
• a torsion factor makes it possible to obtain an enduring reinforcing element having a high breaking force and wherein the twist and the strand titles are compatible with high production rates.
• the torsion factor K of the reinforcing element is related to the torsion R3 of the reinforcing element according to the known relation which follows:
• R1 ranges from 10 to 150 revolutions per meter, preferably from 20 to 120 revolutions per meter and more preferably from 50 to 110 revolutions per meter.
• R1 ranges from 10 to 150 revolutions per meter, preferably from 20 to 120 revolutions per meter and more preferably from 50 to 110 revolutions per meter.
• R2 ranges from 10 to 100 revolutions per meter, preferably from 15 to 75 revolutions per meter and more preferably from 20 to 60 revolutions per meter.
• the ratio R1 / R3 ranges from 0.05 to 0.45, preferably from 0.10 to 0.40, preferably from 0.13 to 0.40, more preferably from 0.13 to 0, 36 and even more preferably from 0.20 to 0.35.
• Such ratios R1 / R3 make it possible to obtain, for a given torsion R3, a good endurance of the reinforcement element and a satisfactory rupture force, while maintaining an elongation with sufficient rupture so as not to cause problems during the process. tire manufacturing, especially during the conformation of the tire.
• the product R1.R3 is greater than or equal to 3000, preferably to 15000, preferably to 30000 and even more preferably to 44000.
• the product R1.R3 is less than or equal to 48000. By limiting the value of the product R1 .R3 to 48000, the risks of industrial variability of the breaking force are reduced.
• the ratio R3 / R2 and R3 satisfy R3 / R2 is from 0.10 to 10.50 and R3 ranges from 200 to 450 revolutions per meter, preferably R3 / R2 ranges from 2.00 to 8.25. and R3 is from 250 to 400 rpm, preferably R3 / R2 is from 2.00 to 7.10 and R3 is from 280 to 400 rpm. Even more preferably, R3 / R2 and R3 satisfy R3 / R2 ranging from 3.20 to 8.75 and R3 is from 235 to 375 turns per meter. In the R3 / R2 intervals and for the R3 values described above, the compromise between breaking strength and endurance is improved.
• the ratio R1 / R2 ranges from 1.90 to 10.00, preferably from 1.90 to 5.00 and more preferably from 1.90 to 2.50.
• the T1 titer of the high modulus textile monofilament strand ranges from 90 to 400 tex, preferably from 100 to 350 tex and more preferably from 140 to 210 tex.
• the T2 titer of the low modulus textile monofilament strand ranges from 80 to 350 tex, preferably from 90 to 290 tex and more preferably from 120 to 190 tex inclusive.
• the breaking force of the reinforcing element is greater than or equal to 30 daN, preferably greater than or equal to 35 daN.
• the breaking force measured according to the ASTM D 885 / D 885MA standard of January 2010, can also be determined from unreinforced reinforcing elements, that is to say without glue or glued reinforcement elements, that is to say covered with a layer of glue. In the case of bonded reinforcement elements, the determination can be carried out indifferently as well to the reinforcement elements directly from manufacturing as to the reinforcement elements extracted from semi-finished product or tire.
• Another object of the invention is a semi-finished product comprising a reinforcing element as defined above embedded in an elastomer matrix.
• An example of a semi-finished product according to the invention is a sheet of reinforcing elements comprising reinforcing elements embedded in an elastomer matrix formed by calendering reinforcing elements between two strips of elastomer.
• the invention also relates to a tire comprising at least one reinforcing element as defined above.
• the tires of the invention may be intended for motor vehicles of the tourism type, 4x4, "SUV” (Sport Utility Vehicles), but also to two-wheeled vehicles such as motorcycles, or to industrial vehicles selected from vans, "heavy goods vehicles” - ie, metros, buses, road transport vehicles (trucks, tractors, trailers), off-the-road vehicles -, agricultural or civil engineering machinery, other transport vehicles or handling.
• SUV Sport Utility Vehicles
• two-wheeled vehicles such as motorcycles
• industrial vehicles selected from vans, "heavy goods vehicles” - ie, metros, buses, road transport vehicles (trucks, tractors, trailers), off-the-road vehicles -, agricultural or civil engineering machinery, other transport vehicles or handling.
• the tires may be intended for motor vehicles of the tourism, 4x4, "SUV” (Sport Utility Vehicles) type.
• the tire comprising two beads each comprising at least one annular reinforcing structure and a carcass reinforcement anchored in each of the beads by a turnaround around the annular reinforcing structure, the carcass reinforcement comprises at least one reinforcing element as defined above.
• the tire comprising two beads each comprising at least one annular reinforcement structure and a carcass reinforcement anchored in each of the beads by a reversal around the annular reinforcing structure, the tire comprising a reinforcement having a crown arranged radially external to the carcass reinforcement, the crown reinforcement comprising a working reinforcement and a hooping reinforcement arranged radially external to the working reinforcement, the hooping reinforcement comprises at least one reinforcement element such as as defined above.
• the hooping web comprises the hooping textile reinforcing elements as defined above and substantially parallel to each other.
• Such hoop reinforcing elements form an angle at most equal to 10 °, preferably ranging from 5 ° to 10 ° with the circumferential direction of the tire.
• the tire comprising two beads each comprising at least one annular reinforcing structure and a carcass reinforcement anchored in each of the beads by a turnaround around of the annular reinforcing structure, the tire comprising a sidewall reinforcing armature, the sidewall reinforcing armature comprises at least one reinforcing element as defined above.
• the tire is adapted for a flat run.
• RMG Rolling Mode Inflated
• the invention is particularly advantageous in the case of a reinforcing element in which the high modulus strand is made of aramid monofilaments and the low modulus strand is made of polyester monofilament.
• the reinforcing element has a relatively low modulus to low deformations (in normal rolling mode), in this case that of the polyester, which is sufficient to ensure RMG performance.
• the reinforcing element has a relatively high deformation (in flat rolling mode), in this case that of the aramid, which proves sufficient to ensure, by itself, the performance RME.
• Such a tire adapted for a flat run preferably comprises a flank insert disposed axially inside the carcass reinforcement.
• the carcass reinforcement comprises a single carcass ply.
• Another object of the invention is a method of manufacturing a reinforcing element as described above, in which:
• the strand of high modulus textile monofilaments is obtained with an initial twist R1 'in a direction D1',
• the strand of low modulus textile monofilaments is obtained with an initial twist R2 'in a direction D2',
• the high and low modulus textile monofilament strands are wrapped around each other in a direction D3 with a twist R3 so that:
• the strand of high modulus textile monofilaments has a residual torsion R1 in a direction D1, and
• the strand of low modulus textile monofilaments has a residual torsion R2 in a direction D2,
• R1 ' ⁇ R2'.
• R1 ' ⁇ R3.
• D1 'and D2' are identical.
• D3 is opposed to D1 'and D2'.
• Figure 1 is a radial sectional view of a tire adapted for a run on a flat according to a first embodiment of the invention
• Figure 2 illustrates a detail view of a reinforcing member of the tire of Figure 1;
• Figures 3 and 4 are views similar to that of Figure 1 of tires respectively according to second and third embodiments.
• FIG. 5 represents force-elongation curves of various reinforcing elements.
• the term "radial” it is appropriate to distinguish several different uses of the word by the person skilled in the art.
• the term refers to a radius of the tire. It is in this sense that we say from point A that it is “radially interior” to a point B (or “radially inside” of point B) if it is closer to the axis of rotation of the tire than the point B.
• a point C is said to be “radially outside a point D (or” radially outside “of the point D) if it is farther from the axis of rotation of the only point D. It will be said that one is advancing "radially inwards (or outward)” when moving towards smaller (or larger) radii. When it comes to radial distances, this sense of the term also applies.
• a reinforcing element or an armature is said to be "radial" when the reinforcing element or the reinforcing elements of the reinforcement make with the circumferential direction an angle greater than or equal to 65 ° and less than or equal to at 90 °.
• radial section or “radial section” means here a section or section in a plane which comprises the axis of rotation of the tire.
• An "axial” direction is a direction parallel to the axis of rotation of the tire.
• a point E is said to be “axially inner” at a point F (or “axially inside” of point F) if it is closer to the median plane of the tire than point F.
• a point G is said to be “ axially outside at a point H (or “axially outside” of point H) if it is farther from the median plane of the tire than point H.
• the “median plane” of the tire is the plane which is normal to the axis of rotation of the tire and which is equidistant from the annular reinforcing structures of each bead.
• a "circumferential" direction is a direction that is perpendicular to both a tire radius and the axial direction.
• FIG. 10 Diagrammatically in Figure 1, a radial sectional view, a tire according to a first embodiment of the invention designated by the general reference 10.
• the tire 10 is of the type for flat rolling.
• the tire 10 is for passenger vehicle.
• This tire 10 has an apex 12 comprising a crown reinforcement 14 comprising a working frame 15 comprising two working plies 16, 18 and a hooping frame 17 comprising a hooping ply 19.
• the crown reinforcement 14 is The hooping frame 17 is disposed radially outside the working frame 15.
• the hooping frame 17 is radially interposed between the working frame 15 and the tread. 20.
• Two self-supporting flanks 22 extend the top 12 radially inwards.
• the tire 10 further comprises two beads 24 radially inner to the flanks 22 and each having an annular reinforcing structure 26, in this case a rod 28, surmounted by a mass of gum 30 padding rod, and a radial carcass reinforcement 32.
• the carcass reinforcement 32 preferably comprises a single carcass ply 34 of reinforcement elements 36, the carcass reinforcement 32 being anchored in each of the beads 24 by a reversal around the annular reinforcing structure 26, so as to form in each bead 24 a forward strand 38 extending from the beads through the sidewalls to the top, and a return strand 40, the radially outer end 42 of the back strand 40 being substantially mid-height of the tire.
• the carcass reinforcement 32 extends from the beads 24 through the flanks 22 towards the apex 12.
• the crown reinforcement 14 is arranged radially outside the carcass reinforcement 32. Thus, the crown reinforcement 14 is radially interposed between the carcass reinforcement 32 and the tread 20.
• the rubber compositions used for the crown plies 16, 18 and carcass plies 34 are conventional compositions for calendering reinforcing elements, typically based on natural rubber, carbon black, a vulcanization system. and customary additives.
• the adhesion between the textile reinforcing element and the rubber composition which surrounds it is ensured for example by a usual RFL-type adhesive.
• the tire 10 further comprises two flank inserts 44 arranged axially on the inside of the carcass reinforcement 32.
• These inserts 44 with their characteristic crescent-shaped radial section are intended to reinforce the sidewall. They comprise at least one polymeric composition, preferably a rubbery mixture.
• WO 02/096677 gives several examples of rubber mixes that can be used to form such an insert.
• Each edge insert 44 may contribute to supporting a load corresponding to a portion of the weight of the vehicle during a run-flat situation.
• the tire also comprises an inner sealing layer 46, preferably of butyl, located axially inside the flanks 22 and radially inner to the crown reinforcement 14 and extending between the two beads 24.
• the flank inserts 44 are located axially external to the inner layer 46.
• the edge inserts 44 are arranged axially between the carcass reinforcement 32 and the inner layer 46.
• the hooping web 19 comprises hooping textile reinforcing elements 36 according to the invention forming an angle at most equal to 10 °, preferably ranging from 5 ° to 10 ° with the circumferential direction Z of the tire 10.
• reinforcing elements not in accordance with the invention could be used.
• Such reinforcing elements comprise, for example, two strands of textile monofilaments made of a heat-shrinkable material, for example polyamide 66 here, each strand consisting of two yarns of 140 tex which have been twisted together (on a direct capper) at 250 revolutions / meter. .
• the carcass ply 34 comprises elements of textile reinforcements 36 according to the invention, one of which is illustrated in FIG. 2.
• the reinforcing elements 36 are parallel to one another.
• Each reinforcing element 36 is radial.
• each reinforcing element 36 extends in a plane substantially parallel to the axial and radial directions of the tire 10.
• Each reinforcing element 36 comprises a single strand 54 of high modulus textile monofilaments, here aromatic polyamide, for example aramid, and a single strand 56 of low modulus textile monofilaments, here polyester or aliphatic polyamide, for example polyester, wound helically around each other in a direction D3 with a twist R3.
• Each reinforcing element 36 consists of a strand 54 and a strand 56.
• the direction D3 is the direction S.
• the polyester is chosen from polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polypropylene terephthalate or polypropylene naphthalate.
• the polyester is polyethylene terephthalate (PET).
• the title T1 of strand 54 of high modulus monofilaments ranges from 90 to 400 tex, preferably from 100 to 350 tex and more preferably from 140 to 210 tex.
• T1 167 tex.
• the T2 titer of strand 56 of low modulus monofilaments ranges from 80 to 350 tex, preferably from 90 to 290 tex and more preferably from 120 to 190 tex.
• T2 144 tex.
• the strand 54 of high modulus monofilaments has a residual torsion R1 substantially non-zero in the direction D1.
• the strand 56 of low modulus monofilaments has a residual torsion R2 in the direction D2.
• the residual torsion R1 of the strand 54 of high modulus monofilaments ranges from 10 to 150 turns per meter, preferably from 20 to 120 turns per meter and more preferably from 50 to 1 10 turns per meter.
• R1 100 turns per meter.
• the residual torsion R2 of the strand 56 of low modulus monofilaments ranges from 10 to 100 revolutions per meter, preferably from 15 to 75 revolutions per meter and more preferably from 20 to 60 revolutions per meter, so that the condition R 1> R2 or R1> 0 is checked according to whether R2 is substantially non-zero or zero.
• R2 50 turns per meter.
• D1 and D2 are identical.
• D1, D2 and D3 are identical and are here the direction S.
• R1 and D3 are identical.
• the ratio R1 / R3 ranges from 0.05 to 0.45, preferably from 0.10 to 0.40, preferably from 0.13 to 0.40, more preferably from 0.13 to 0.36 and still more preferably from 0.20 to 0.35.
• R1 / R3 0.29.
• the product R1 .R3 is greater than or equal to 3000, preferably 15000, preferably 30000.
• R1 .R3 34000.
• R1 .R3 is greater than or equal to 44000.
• the product R1.R3 is less than or equal to 48000.
• the reinforcement element 36 is such that the ratio R3 / R2 and the value of R3 satisfy R3 / R2 is from 0.10 to 10.50 and R3 ranges from 200 to 450 revolutions per meter, preferably R3 / R2 ranges from 2.00 to 8.25 and R3 ranges from 250 to 400 revolutions per meter, preferably R3 / R2 ranges from 2.00 to 7.10 and R3 ranges from 280 to 400 revolutions per meter. Even more preferably, R3 / R2 and R3 satisfy R3 / R2 ranging from 3.20 to 8.75 and R3 is from 235 to 375 turns per meter.
• the reinforcing element 36 is such that the ratio R 1 / R 2 ranges from 1.90 to 10.00, preferably from 1.90 to 5.00 and more preferably from 1.90 to 2, 50.
• R2 / R2 2.00.
• the reinforcing element 36 has a torsion factor K ranging from 130 to 200, preferably from 140 to 190.
• K 160.
• the final modulus Mf1 of strand 54 of high modulus textile monofilaments is greater than or equal to 30 cN / tex, preferably 35 cN / tex and more preferably 40 cN / tex.
• Mf 1 64.5 cN / tex.
• the final modulus Mf2 of strand 56 of low modulus textile monofilaments is less than or equal to 20 cN / tex, preferably 15 cN / tex and more preferably 10 cN / tex.
• Mf2 7.1 cN / tex.
• the Mf1 / Mf2 ratio of the final modulus of the strand 54 of high modulus textile monofilaments to the final modulus of strand 56 of low modulus textile monofilaments is greater than or equal to 2, preferably 5 and more preferably 7.
• Mf1 / Mf2 is less than or equal to 15 and preferably 10.
• Mf1 / Mf2 9.1.
• the breaking force of the reinforcing element 36 is greater than or equal to 30 daN, preferably greater than or equal to 35 daN.
• FIGS. 3 and 4 show tires respectively according to second and third embodiments of the invention. Elements similar to those of the first embodiment are designated by identical references.
• the tire 10 according to the second embodiment of Figure 3 is not suitable for a run flat. Thus, it is devoid of flank inserts 44.
• the tire 10 of the second embodiment comprises hoop reinforcing elements according to the invention.
• the tire 10 of the second embodiment comprises hoop reinforcing elements not in accordance with the invention.
• the tire 10 according to the third embodiment of Figure 4 comprises a reinforcement armature 48 flank preferably comprising a single sheet 50 of sidewall reinforcement.
• the flank reinforcement armature 48 is arranged axially outside the outward strand 38 and extends, in each bead 24, axially outside the return strand 40 of the carcass ply 34.
• the flank reinforcement armature 48 may be arranged radially between the forward strand 38 and the back strand 40 of the carcass ply 34.
• the radially inner end 52 of the side reinforcement reinforcement 48 is radially inside the radially outer end 53 of the return strand 40 of the carcass reinforcement 32.
• the radially outer end 54 of the the flank reinforcement armature 25 is axially inside the axially outer end 55 of the crown ply radially adjacent to the sidewall reinforcing armature 48, here the radially innermost working ply 18; inside.
• Other configurations of the ends 52 and 54 with respect to the ends 53 and 55 are possible and for example described in WO2014040976.
• the sidewall reinforcing armature comprises reinforcing elements according to the invention.
• a step of obtaining strand 54 of high modulus textile monofilaments starting from a high modulus textile monofilament yarn and twisting this yarn in a direction D1 'with an initial twist R1'. We obtain the strand 54.
• Each yarn in English “yarn"
• the elementary textile monofilaments are thus imposed a helical deformation around the axis of the fiber strand.
• D1 'and D2' are identical and here are the direction Z. Moreover, R1 ' ⁇ R2' with here R1 -240 turns per meter and R2 -290 turns per meter.
• the strands 54, 56 of high and low modulus textile monofilaments are wound one around the other in a direction D3 with a twist R3 so that on the one hand, the strand of textile monofilaments to high modulus has a residual torsion R1, here substantially non-zero, in a direction D1, and secondly, the strand of low modulus textile monofilaments has a residual torsion R2 in a direction D2.
• the residual torsions R1 and R2 are such that R1> R2 in the case where R2 is substantially non-zero and R1 is substantially non-zero in the case where R2 is substantially zero. In this case, in the example of the reinforcing element 36, R1> R2.
• PET is marketed by Hyosung under the name HSP40 NAA.
• the aramid is marketed by the company Teijin under the name Twaron 1000.
• Prior conditioning means the storage of the reinforcing elements (after drying) for at least 24 hours, before measurement, in a standard atmosphere according to the European standard DIN EN 20139 (temperature of 20 ⁇ 2 ° C, hygrometry of 65 ⁇ 2%).
• the title (or linear density) of the elementary strands or reinforcing elements is determined according to the ASTM D1423 standard. The title is given in tex (weight in grams of 1000 m of product - recall: 0, 111 tex equal to 1 denier).
• the endurance is determined by conducting a bending endurance test in accordance with ASTM D430-06 (Method A) in which a reciprocating movement is made to a semi-finished product comprising several reinforcement elements embedded in an elastomer matrix in contact with a pulley. At the end of 600,000 cycles, the reinforcing elements are extracted from the elastomer matrix and the breaking force Ft is measured. This breaking force Ft is compared with the breaking force Fr before the endurance test in flexion. . The decay in% Dt is given by the relation difference (1 -Ft / Fr) .100 and the endurance is given by the relation 100.Ft / Fr and is reported in Table 1
• the NM indicates that the value has not been measured.
• reinforcing elements I and 36 shows that, in accordance with the invention, two residual torsions R1, R2 with R1 such that R1> R2 make it possible to obtain at the same time a breaking force equivalent to that of the control.
• the carcass reinforcement 32 of the tire may comprise two carcass plies 34.
• An embodiment may also be provided in which the return strand 40 rises between the crown ply 18 and the forward strand 38.

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• 2015
  • 2015-03-31 FR FR1552699A patent/FR3034435B1/fr not_active Expired - Fee Related
• 2016
  • 2016-03-25 JP JP2017550487A patent/JP6806697B2/ja active Active
  • 2016-03-25 CN CN201680020491.3A patent/CN107531095B/zh active Active
  • 2016-03-25 US US15/554,583 patent/US10688828B2/en active Active
  • 2016-03-25 WO PCT/EP2016/056702 patent/WO2016156263A1/fr not_active Ceased
  • 2016-03-25 EP EP16714818.8A patent/EP3277869B1/fr active Active

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