Tire comprising two carcass layers

Abstract

A tyre (11) for passenger vehicle comprises a crown (12), two beads (32), two sidewalls (30) and a carcass reinforcement (34) anchored in each bead (32), the two sidewalls (30) connecting each bead (32) to the crown (12), respectively. A load index LI of the tyre (11) satisfies LI ≥ LI' with LI' being a load index of an overloading tyre having the same dimensions according to the 2019 ETRTO Standard Handbook. A sidewall height H of the tyre (11) is defined as H = SW x AR / 100 and satisfies H ≥ 95, with SW being a nominal section width of the tyre according to the 2019 ETRTO Standard Handbook and AR being a nominal height-to-width ratio. The carcass reinforcement (34) comprises two carcass plies (36, 37).

Description

Technical Field

[0001] This invention relates to tires, mounting assemblies including such tires, and passenger vehicles including such tires or such mounting assemblies. A tire is understood to mean an outer tire designed to form a cavity by cooperating with a support element of the mounting assembly, the cavity being pressurized to pressures above atmospheric pressure. The mounting assembly according to the invention has a generally torus-shaped structure exhibiting rotational symmetry about the main axis of the mounting assembly (which coincides with the main axis of the tire). Background Technology

[0002] The development of electric or hybrid passenger vehicles has led to an increase in vehicle weight, particularly due to batteries, which have a relatively high weight that is roughly proportional to the vehicle's driving range. Therefore, for example, to increase the driving range of electric vehicles, the size of the batteries needs to be increased, thus increasing the vehicle's weight.

[0003] In short, current estimates suggest that one kilometer of range for an electric motor would increase a vehicle's weight by one kilogram. Therefore, to achieve a 500-kilometer range, an internal combustion engine vehicle would need to be approximately 500 kilograms heavier. To equip such a vehicle, tires capable of withstanding extremely high loads would be required.

[0004] A tire for passenger vehicles is known in the prior art, capable of bearing relatively high loads. This tire is known as MICHELIN in the Pilot Sport 4 series. TM This branded tire is for sale in size 255 / 35R18. It is an EXTRA LOAD (XL) tire as defined in the ETRTO 2019 standard manual, with a load index of 94. This means the tire can carry a load of 670 kg at 290 kPa. This load capacity is relatively high compared to a tire of the same size designated STANDARD LOAD (SL), which has a load index of 90 and can carry a load of 600 kg at 250 kPa.

[0005] For such tires to be marketed, they must pass prescribed tests. For example, in Europe, tires must pass the load / speed performance tests described in Annex VII of UN / ECE Regulation No. 30.

[0006] However, in overload models, such tires cannot withstand the additional load corresponding to the battery required to achieve the desired driving range, and this is even more true in standard load models. Therefore, tire manufacturers have had to develop new solutions to meet this new demand.

[0007] One solution considered by tire manufacturers is to use larger tires for a given vehicle, thereby enabling it to bear a greater load. Therefore, a given vehicle can be fitted with tires having a higher load index. For example, a vehicle equipped with the aforementioned overload-bearing tires could be fitted with 275 / 35R19 overload-bearing tires, which have a load index of 100 and can withstand a load of 800 kg at 290 kPa, far exceeding a load of 670 kg.

[0008] This increase in tire size inevitably requires either a reduction in the vehicle's interior space or an increase in its external volume, neither of which is desirable for the sake of a spacious and compact vehicle.

[0009] Furthermore, this increase in tire size would require a redesign of the vehicle chassis, which is undesirable for obvious cost reasons.

[0010] Finally, this increase in tire size (especially the increase in nominal cross-sectional width) leads to an increase in external noise and rolling resistance, which is not conducive to reducing vehicle noise pollution and energy consumption.

[0011] Therefore, another solution considered by tire manufacturers is to increase the recommended inflation pressure for a given size and model of tire. This is because higher pressure allows the tire to withstand higher loads.

[0012] However, using relatively high recommended pressures can harden tires and cause a loss of comfort for vehicle passengers, which is clearly not what some motor vehicle manufacturers want when passenger comfort takes precedence over load capacity.

[0013] Another problem tire manufacturers face is that tires with relatively high sidewalls have relatively high carcass reinforcements with relatively high tension, and the greater the load to be carried, the greater the tension. Summary of the Invention

[0014] The purpose of this invention is to provide a tire that can carry a greater load than existing tires without increasing the recommended tire pressure, while still controlling the tension of the tire carcass reinforcement, and without sacrificing the vehicle's sense of space, compactness, and comfort.

[0015] Therefore, the subject of this invention is a tire for passenger vehicles, comprising a crown, two beads, two sidewalls, and a carcass reinforcement anchored in each bead, each sidewall connecting each bead to the crown, the crown including a crown reinforcement and a tread, the carcass reinforcement extending radially inward in each sidewall and crown.

[0016] The load index LI of the tire satisfies LI>LI'+1, where LI' is the load index of an overloaded tire of the same size according to the ETRTO 2019 standard manual.

[0017] The tire sidewall height H is defined as H = SW x AR / 100 and satisfies H ≥ 95, where SW is the nominal cross-sectional width of the tire according to the ETRTO 2019 standard manual and AR is the nominal aspect ratio.

[0018] The tire body reinforcement includes a first tire body layer and a second tire body layer.

[0019] According to the present invention, the tire is a tire for passenger vehicles. Such tires are defined, for example, in the ETRTO (European Tyre and Rim Technology Organization) 2019 Standards Manual. Such tires typically have markings on at least one sidewall consistent with the markings in the ETRTO 2019 Standards Manual, indicating the tire size in the form X / YαV Uβ, where X represents the nominal section width, Y represents the nominal aspect ratio, α represents the R or ZR configuration, V represents the nominal rim diameter, U represents the load index, and β represents the speed rating.

[0020] The load index LI' is the load index of tires with the same dimensions, that is, tires with the same nominal section width, the same nominal aspect ratio, the same construction (R and ZR are considered the same), and the same nominal rim diameter. In the ETRTO 2019 standard manual, specifically in the section titled Passenger Car Tyres – Tyres with Metric Designation (pages 20-41), the load index LI' is given.

[0021] By increasing the load index of the tire of the present invention relative to the load index of an overload model tire of the same size, the present invention allows for an increase in the load capacity of the mounting assembly without altering the sense of space, compactness, and comfort of the vehicle using the tire. This is because, since the tire according to the present invention has the same dimensions as the overload model tire, the mounting assembly does not occupy more space than the overload model tire. The tire according to the present invention can bear unique markings distinguishing it from the standard load model and the overload model, such as HL (high load) or XL+ (overload+) type markings. Such markings to indicate high load capacity tires are specifically disclosed in the General Notes – Passenger Car Tyres section (page 3) of the ETRTO 2021 Standard Manual. Examples of sizes are also disclosed in the Passenger Car Tyres – Tyres with Metric Designation section (page 44, section 9.1) of the ETRTO 2021 Standard Manual.

[0022] As explained above, tires with a relatively large sidewall height result in relatively high tension in the carcass reinforcement (particularly the portion of the carcass reinforcement anchored in the bead (e.g., by winding around the circumferential reinforcing element, such as bead cord)) because they contain a relatively large volume of inflation gas compared to tires with a relatively small sidewall height. The higher the load carried, the greater this tension, as is the case with the tires according to the invention having a load index L1. Therefore, two carcass layers must be used, thereby allowing for a significant reduction in tension in each carcass layer.

[0023] Furthermore, compared to tires with relatively short sidewalls (i.e., H < 95), the tire according to the invention exhibits relatively low compression of the carcass reinforcement due to its relatively high height. Therefore, even with two carcass layers, the risk of premature degradation of the carcass reinforcement is avoided, particularly under high loads and relatively low pressures.

[0024] The first and second carcass layers are each defined axially by their respective two axial edges and include carcass filamentary reinforcing elements extending axially from one axial edge of the first and second carcass layers to the other axial edge.

[0025] The nominal section width (SW) and nominal aspect ratio (AR) are those indicated by the dimension markings engraved on the tire sidewall, according to the ETRTO 2019 standard manual.

[0026] The tire according to the invention has a generally toroidal shape about an axis of rotation substantially coincident with the tire's axis of rotation. This axis of rotation defines three directions commonly used by those skilled in the art: axial direction, circumferential direction, and radial direction.

[0027] The axial direction is understood as the direction that is substantially parallel to the axis of rotation of the tire or mounting assembly (i.e., the axis of rotation of the tire or mounting assembly).

[0028] The circumferential direction is understood as a direction that is essentially perpendicular to both the axial direction and the radius of the tire or mounting assembly (in other words, tangent to a circle centered on the axis of rotation of the tire or mounting assembly).

[0029] The radial direction is understood as the direction along the radius of the tire or mounting assembly, that is, any direction that intersects the axis of rotation of the tire or mounting assembly and is substantially perpendicular to that axis.

[0030] The tire's midplane (denoted by M) is understood as a plane perpendicular to the tire's axis of rotation, located axially between the two bead sections and passing through the axial center of the crown reinforcement.

[0031] In the meridional section plane, the tire's equatorial circumferential plane is understood as a plane passing through the tire's equator and perpendicular to the midplane and radial direction. In the meridional section plane (a plane perpendicular to the circumferential direction and parallel to the radial and axial directions), the tire's equator is the axis parallel to the tire's axis of rotation and equidistant between the outermost radial point of the tread intended to contact the ground and the innermost radial point of the tire intended to contact a support (e.g., the rim).

[0032] The meridional plane is understood as a plane that is parallel to, contains, and is perpendicular to the circumferential direction of the tire or mounting assembly's axis of rotation.

[0033] "Radially located inside" and "radially located outside" can be understood as being closer to the tire's axis of rotation and farther away from it, respectively. "Axially located inside" and "axially located outside" can be understood as being closer to the tire's midplane and farther away from it, respectively.

[0034] A tire bead is understood as the portion of a tire designed to allow it to be attached to a mounting support (such as a wheel including a rim). Therefore, each tire bead is specifically designed to contact the flange of the rim for attachment.

[0035] Any range of values ​​expressed as “between a and b” represents a range of values ​​from greater than a to less than b (i.e., excluding the endpoints a and b), while any range of values ​​expressed as “from a to b” means a range of values ​​from a to b (i.e., including the strict endpoints a and b).

[0036] Preferably, the first carcass layer and the second carcass layer each extend radially inside the crown reinforcement in each sidewall and crown.

[0037] In an optional but advantageous implementation, H ≥ 100.

[0038] In an advantageous implementation, LI'+1≤LI≤LI'+4, preferably LI'+2≤LI≤LI'+4. Therefore, the load-bearing capacity of the tire is further increased.

[0039] Optionally, the first carcass layer and the second carcass layer are each defined axially by two axial edges of the carcass layer and include a carcass fabric filamentary reinforcing element extending axially from one axial edge of the carcass layer to the other axial edge in a principal direction, the principal direction forming an angle with the circumferential direction of the tire in an absolute value range of 80° to 90°.

[0040] A filamentary element is understood to be an element with a length at least 10 times its maximum cross-sectional dimension, regardless of the shape of the cross-section: circular, elliptical, rectangular, polygonal, and especially rectangular, square, or oval. In the case of a rectangular cross-section, the filamentary element takes the form of a strip.

[0041] A fabric element is understood to mean a filamentous element comprising one or more basic fabric filaments, which are optionally coated with one or more coatings based on an adhesive composition. The one or more basic fabric filaments are obtained, for example, by melt spinning, solution spinning, or gel spinning. Each basic fabric filament is made of an organic material (particularly a polymeric material) or an inorganic material (e.g., glass or carbon). The polymeric material can be thermoplastic, such as aliphatic polyamides (particularly polyamide 6,6) and polyesters (particularly polyethylene terephthalate). The polymeric material can also be non-thermoplastic, such as aromatic polyamides (particularly aramid) and cellulose (natural or man-made, particularly rayon).

[0042] In a preferred embodiment, one of the first carcass layer and the second carcass layer is wound around the circumferential reinforcing element of each bead, such that the axial inner portion of the carcass layer is axially disposed inside the axial outer portion of the carcass layer, and each axial end of the carcass layer is radially disposed outside each circumferential reinforcing element.

[0043] In certain preferred variants, regardless of the sidewall height, each axial end of the carcass layer forming the wrapping is arranged radially inside the tire equator, and even more preferably at a radial distance of less than or equal to 30 mm from the radially inner end of each circumferential reinforcing element of each bead.

[0044] By arranging each axial end of the wound carcass ply inside the tire equator, the mass of the carcass reinforcement is significantly reduced. Furthermore, the vast majority of rims currently used in passenger vehicle tires have J-flanges, the height of which is in all cases less than 30 mm. Arranging each axial end very preferably in a region radially corresponding substantially to the rim flange allows for mechanical protection of each axial end. This is because if each axial end were arranged too far radially above each circumferential reinforcement element of each bead, i.e., at a radial distance strictly greater than 30 mm from the radially inner end of each circumferential reinforcement element, each axial end would be located in a flexible region of the tire subjected to excessive stress (which is very high in the case of high-load-capacity tires).

[0045] In a first preferred configuration matching the presence of a first carcass layer and a second carcass layer, the first carcass layer is wound around the circumferential reinforcing element of each bead, such that the axially inner portion of the first carcass layer is axially arranged inside the axially outer portion of the first carcass layer and each axial end of the first carcass layer is radially arranged outside each circumferential reinforcing element, and each axial end of the second carcass layer is radially arranged inside each axial end of the first layer and arranged as follows:

[0046] -Located axially between the inner and outer portions of the first carcass layer, or

[0047] -Located axially inside the inner portion of the first carcass layer.

[0048] Preferably, each axial end of the second carcass layer is arranged axially between the inner and outer axial portions of the first carcass layer.

[0049] This arrangement of the first and second tire carcass layers allows for an effective mechanical connection between them, thereby reducing shear stress between them. This reduces energy dissipation and temperature rise in the tire, especially under high loads and when shear stress is particularly high.

[0050] In fact, this arrangement of the carcass reinforcement is particularly advantageous when 95 ≤ H ≤ 155. This is because by limiting the tire sidewall height to a sidewall height H that satisfies 95 ≤ H ≤ 155, the volume of gas is reduced, thus reducing the tension of the carcass reinforcement to a reasonable level.

[0051] Furthermore, by means of a specific arrangement of the first and second carcass layers, a tire with optimal energy dissipation and operating temperature in the sidewall is unexpectedly obtained, particularly under high loads and at pressures less than or equal to the recommended pressures of standard or overload tires of the same size. This is even more surprising because the specific arrangement of the first and second carcass layers is located in one area of ​​the tire (in this case, in or near the bead), thus reducing energy dissipation in another area of ​​the tire away from the bead (in this case, the sidewall). It has been found that the specific arrangement of the carcass reinforcement, i.e., each axial end of the second carcass layer axially positioned between the axially inner and axially outer portions of the first carcass layer or axially positioned inside the axially inner portion of the first carcass layer, reduces the tension difference between the first and second carcass layers. In fact, the smaller the tension difference between the first and second carcass layers, the smaller the shear stress generated between the first and second carcass layers, and the less energy is dissipated.

[0052] In a second configuration matching the presence of a first carcass layer and a second carcass layer, the first carcass layer is wound around the circumferential reinforcing element of each bead, such that the axial inner portion of the first carcass layer is axially arranged inside the axial outer portion of the first carcass layer and that each axial end of the first carcass layer is radially arranged outside each circumferential reinforcing element, and each axial end of the second carcass layer is radially arranged inside each axial end of the first layer and axially arranged outside each axial outer portion of the first carcass layer.

[0053] This second configuration is particularly advantageous when H > 155. This is because, for high-load-capacity tires with very high sidewall heights satisfying H > 155, the tension at the ends of the first carcass ply becomes very high. Therefore, a carcass reinforcement should be considered where, unlike the arrangement described in the first configuration, each axial end of the second carcass ply is axially arranged outside each axially outer portion of the first carcass ply. With this arrangement of the carcass reinforcement, the tension at the ends of the first carcass ply will be reduced to a reasonable level.

[0054] For high-load capacity tires with very high sidewall height (i.e., H > 155), even if the tension difference between the first carcass layer and the second carcass layer is still significant, the sidewall height allows for a relatively large shear area that can effectively dissipate energy. For such a shear area, it is preferable not to have the arrangement of the first and second carcass layers as described in the first configuration.

[0055] Each filamentary reinforcing element of the body fabric preferably comprises an assembly of at least two multifilament strands with a total filament count of less than or equal to 475 tex.

[0056] This is because the presence of two carcass layers allows for a reduction in the total number of filaments in each carcass fabric reinforcing element of each layer, while still achieving sufficient mechanical strength in the carcass reinforcement.

[0057] Optionally, each of the filamentary reinforcing elements of the first and second carcass layers has an average diameter D1 and D2, respectively, satisfying that D1≤0.90mm and D2≤0.90mm, preferably D1≤0.85mm and D2≤0.85mm, and more preferably D1≤0.75mm and D2≤0.75mm.

[0058] Such relatively small diameters D1 and D2 allow for the limitation of crack initiation near the respective ends of the first and second carcass layers. This is because the ends of each carcass fabric filamentary reinforcing element constitute locations where cracks are more likely to occur, particularly since these elements lack any adhesive composition and are therefore less likely to adhere to the adjacent matrix into which they are embedded. Reducing each diameter D1, D2 decreases the surface area at the ends, thereby reducing the risk of crack initiation. Optionally, D1 and D2 satisfy D1 ≥ 0.55 mm and D2 ≥ 0.55 mm, preferably D1 ≥ 0.60 mm and D2 ≥ 0.60 mm.

[0059] The yarn count (or linear density) for each strand and filament reinforcement element is determined according to the 2014 standard ASTM D 885 / D 885M–10a. The yarn count is expressed in tex (weight in grams of 1000 meters of product; as a reminder: 0.111 tex equals 1 denier).

[0060] The diameter of each filamentary reinforcing element in the carcass fabric is the diameter of the smallest circle circumscribed around the filamentary reinforcing element. The average diameter is the average of the diameters of the filamentary reinforcing elements in the carcass fabric arranged along a 10cm length of each carcass layer.

[0061] Each polyfilament strand is selected from polyester polyfilament strands, aramid polyfilament strands, and aliphatic polyamide polyfilament strands, preferably, each polyfilament strand is selected from polyester polyfilament strands and aramid polyfilament strands.

[0062] Polyester multifilament strands are understood as multifilament strands composed of monofilaments of linear macromolecules linked together by ester bonds. Polyesters are produced through polycondensation via esterification reactions between dicarboxylic acids or their derivatives and glycols. For example, polyethylene terephthalate (PET) can be produced through polycondensation of terephthalic acid and ethylene glycol. Among known polyesters, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polybutylene naphthalate (PBN), polypropylene terephthalate (PPT), or polypropylene naphthalate (PPN) may be mentioned.

[0063] Aromatic polyamide multifilament strands are understood to be multifilament strands composed of monofilaments of linear macromolecules formed by aromatic groups bonded together by amide bonds, wherein at least 85% of the amide bonds are directly connected to two aromatic rings, and the monofilaments are more particularly poly(p-phenylene terephthalamide) (or PPTA) fibers, which have been produced from optically anisotropic spinning compositions for a long time. Among aromatic polyamides, references may be made to polyarylamides (or PAA, especially PAA known by the trademark Ixef from Solvay), poly(m-phenylene adipamide), polyphthalamide (or PPA, especially PPA known by the trademark Amodel from Solvay), amorphous semi-aromatic polyamides (or PA6-3T, especially PA6-3T known by the trademark Trogamid from Evonik), or para-aramids (or poly(p-phenylene terephthalamide) or PA PPD-T, especially poly(p-phenylene terephthalamide) known by the trademark Kevlar from Du Pont de Nemours or by the trademark Twaron from Teijin).

[0064] Aliphatic polyamide multifilament strands are understood as multifilament strands composed of monofilaments of linear macromolecules containing amide functional groups, wherein the polymer or copolymer has no aromatic rings and can be synthesized by polycondensation between carboxylic acids and amines. Among aliphatic polyamides, nylon PA4.6, PA6, PA6.6, or PA6.10 can be mentioned, especially Zytel from DuPont, Technyl from Solvay, or Rilsamid from Arkema.

[0065] Very preferably, the component is selected from components having two polyester multifilament strands and components having both polyester multifilament strands and aramid multifilament strands.

[0066] In a preferred embodiment, the tire has a nominal section width SW ranging from 225 to 315, a nominal aspect ratio ranging from 25 to 55, a nominal rim diameter ranging from 18 to 23, and a load index LI ranging from 98 to 116, preferably a nominal section width SW ranging from 245 to 315, a nominal aspect ratio ranging from 30 to 45, a nominal rim diameter ranging from 18 to 23, and a load index LI ranging from 98 to 116. As explained above, the tire according to the invention is designed to bear relatively high loads, inevitably resulting in relatively higher wear compared to overloaded tires of the same size. Therefore, it is particularly advantageous to use a tire with a relatively large nominal section width to reduce the pressure applied to the tread, thereby reducing wear.

[0067] Advantageously, 0.88 ≤ H / LI ≤ 0.98. Therefore, the invention is preferably applicable to tires that may have relatively significant flexure, because for a given sidewall height, they have a relatively high load index, i.e., a load index satisfying H / LI ≤ 0.98. This can be achieved through a specific arrangement of the carcass reinforcements that allows for reduced energy dissipation despite significant sidewall flexure. However, if the sidewall is too short relative to the load index, i.e., H / LI < 0.88, the sidewall flexure results in relatively high compression of the first carcass layer, leading to increased energy dissipation.

[0068] A particularly preferred embodiment is that the tire size and load index L1 are selected from the following size and load index embodiments: 225 / 55R18 105, 225 / 55ZR18 105, 205 / 55R19 100, 205 / 55ZR19 100, 235 / 45R21 104, 235 / 45ZR21 104, 285 / 45R22 116, 285 / 45ZR22 116, 245 / 40R19 101, 245 / 40ZR19 101, 255 / 40R20 104, 255 / 40ZR20 104, 245 / 40R21 103, 245 / 40ZR21 103, 255 / 40R21 105, 255 / 40ZR21 105, 265 / 40R21 108, 265 / 40ZR21 108, 255 / 40R22 106, 255 / 40ZR22 106, 275 / 35R21 105, 275 / 35ZR21 105, 285 / 35R21 108, 285 / 35ZR21 108, 295 / 35R22 111, 295 / 35ZR22 111, 275 / 35R23 108, 275 / 35ZR23 108, 325 / 30R21 111, 325 / 30ZR21 111.

[0069] In some embodiments, the crown reinforcement includes a working reinforcement comprising a radially inner working layer and a radially outer working layer disposed radially outside the radially inner working layer.

[0070] In some embodiments, each working layer is defined axially by two axial edges of the working layer and includes working filamentary reinforcing elements that extend axially from one axial edge of the working layer to the other axial edge in a substantially parallel manner.

[0071] Optionally, each working filamentary reinforcing element extends along a main direction, which forms an angle with the circumferential direction of the tire with an absolute value strictly greater than 10°, preferably ranging from 15° to 50°, and more preferably from 20° to 35°.

[0072] Preferably, in an embodiment where the working reinforcement includes a radially innermost working layer and a radially outermost working layer arranged radially outside the radially innermost layer, the main directions of extension of each working filamentary reinforcement element of the radially innermost working layer and the main directions of extension of each working filamentary reinforcement element of the radially outermost working layer form opposite orientations to the circumferential direction of the tire.

[0073] Optionally, the crown reinforcement includes a hoop reinforcement defined axially by two axial edges of the hoop reinforcement and including at least one hoop filamentary reinforcement element, the at least one hoop filamentary reinforcement element being helically wound circumferentially to extend axially between the axial edges of the hoop reinforcement.

[0074] Preferably, the hoop reinforcement is arranged radially on the outside of the working reinforcement.

[0075] Preferably, the ring-shaped filamentary reinforcing element or each ring-shaped filamentary reinforcing element extends along the main direction, which forms an angle with the circumferential direction of the tire with an absolute value of less than or equal to 10°, preferably less than or equal to 7°, and more preferably less than or equal to 5°.

[0076] Another subject of the present invention is an installation component comprising:

[0077] -Including rim mounting supports, and

[0078] - Tires as defined above, mounted on the rim.

[0079] Advantageously, the crown reinforcement is arranged radially between the tread and the carcass reinforcement and includes a working reinforcement comprising at least one axially narrowest working layer having an axial width T2 in mm, and the rim having a rim width A in mm according to the ETRTO 2019 standard manual, in which case the ratio T2 / A satisfies T2 / A ≤ 1.00.

[0080] To control energy dissipation and temperature in the structure during tire operation according to the invention, it is preferable to ensure that the axial width of the narrowest working ply is appropriately sized relative to the width of the rim. This is because, under high load conditions greater than those known in the prior art, tire deflection (i.e., the difference between the radius of the unloaded mounting assembly and the radius of the mounting assembly under that load) increases significantly. This increase in deflection leads to relatively high energy dissipation and relatively large temperature rise in the tire structure, particularly in the bead.

[0081] To control this, it is preferable to straighten the tire sidewalls, that is, to make the sidewalls straighter in the radial direction. The aim is to increase the radial stiffness of the tire, thereby preventing excessive tire flexing and energy dissipation and temperature increase in the tire structure. Therefore, it is recommended to reduce the ratio T2 / A to a value less than or equal to 1.00 so that:

[0082] - For a given rim width A, reducing the axial width T2 of the narrowest working layer reduces the width of the contact patch, thereby straightening the tire sidewall radially.

[0083] - For a given axial width T2 of the narrowest working layer, increase the rim width A, which also makes the tire sidewall straighter in the radial direction.

[0084] If those skilled in the art change the axial width T2 of the narrowest working layer, they will adjust the characteristics of the tire crown, particularly the characteristics of the crown reinforcement including the working reinforcement and any ring reinforcement, as well as the characteristics of the tread, based on the determined axial width T2.

[0085] In both cases, the radial stiffness of the tire increases, thus reducing tire deflection for a given load. This allows the effects of increased load to be at least partially offset, and the stress applied to the tire structure is reduced, thereby reducing energy dissipation and temperature rise during tire operation.

[0086] To limit the increase in rotational mass on the vehicle, and also to reduce the space occupied by mounting components to improve the vehicle's space and compactness, it is preferable to reduce the axial width T2 of the narrowest working layer rather than increase the rim width A. The axial width of the narrowest working layer is measured on the tire section in the meridional plane and corresponds to the width in the axial direction between the two axial ends of the working layer.

[0087] Preferably, the narrowest axial working layer is the outer radial working layer of the working reinforcement.

[0088] In equally advantageous embodiments, 0.85≤T2 / A, preferably 0.90≤T2 / A, and more preferably 0.93≤T2 / A≤0.97.

[0089] The ratio T2 / A is preferably not too small. Specifically, for a given rim width A, it is preferable not to excessively reduce the value of the axial width T2 of the narrowest working ply, because otherwise the bending stiffness along the edge will decrease, and therefore the lateral stiffness under high cornering conditions will decrease. Furthermore, if the value of the axial width T2 of the narrowest working ply is reduced too much, the width of the contact patch decreases, thereby increasing the pressure applied to the tread and thus increasing wear, which is amplified because the tire according to the invention is designed to bear relatively high loads (inevitably leading to high wear, in any case higher than the wear of an overloaded tire of the same size (which needs to bear less load)). For a given axial width T2 of the narrowest working ply, it is also preferable not to increase the value of the rim width A too much, so as to limit the increase in rotational mass on the vehicle, as explained above, and also to reduce the space occupied by the mounting components to facilitate the space and compactness of the vehicle.

[0090] In a preferred embodiment, the tire has a nominal section width SW that satisfies T2 ≥ SW – 75, preferably T2 ≥ SW – 70. For a given nominal section width, the narrowest axial working layer, which primarily defines the width of the contact patch, will not be too small. Indeed, as explained above, although the tire is designed to bear relatively high loads (inevitably leading to relatively high wear), this allows for maintaining good tire wear performance.

[0091] In a preferred embodiment, the tire has a nominal section width SW, which satisfies T2≤SW–27, preferably T2≤SW–30.

[0092] In these embodiments, such as in the present invention in general, the nominal cross-sectional width is the nominal cross-sectional width indicated by the dimension markings engraved on the tire sidewall.

[0093] To reduce the risk of mounting a tire on a rim that is too narrow, resulting in a relatively high degree of tire shoulder flex, it is preferable to limit the rims that can be used with the tire. Therefore, the rims selected are:

[0094] - According to the ETRTO 2019 standard manual, the rim width designation is equal to the rim width designation measured for the tire size.

[0095] - The rim width designation is equal to the measured rim width designation for the tire size minus 0.5 for the rim.

[0096] - The rim width designation is equal to the rim width designation measured for the tire size plus 0.5 rim width.

[0097] Measurements of wheel rims are specifically defined in the section on passenger vehicle tires – metric tires (pages 20-41) of the ETRTO 2019 Standards Manual.

[0098] In order to limit the increase of rotational mass on the vehicle, and also to reduce the space occupied by the mounting components to facilitate the vehicle's space and compactness, the rim width designation is preferably equal to the rim width designation measured for the tire size minus 0.5.

[0099] Advantageously, the tire is inflated to a pressure ranging from 200 to 350 kPa, preferably 250 to 330 kPa. This pressure is the pressure at which the components are installed when the tire is not in operation at 25°C. It typically corresponds to one of the inflation pressures recommended by the motor vehicle manufacturer.

[0100] For applications where the load-bearing capacity of the tires needs to be prioritized, a relatively high pressure of 270 kPa or higher will be used.

[0101] For applications where passenger comfort and vehicle performance (especially grip on dry surfaces) are given priority, a relatively low pressure of less than or equal to 270 kPa will be used.

[0102] Another subject of the invention is a passenger vehicle that includes at least one tire or mounting component as defined above. Attached Figure Description

[0103] The invention will be better understood by reading the following description, which is given by way of non-limiting example only with reference to the accompanying drawings, wherein:

[0104] - Figure 1 This is a meridional cross-sectional plan view of the mounting assembly according to the first embodiment of the present invention.

[0105] - Figure 2 for Figure 1 Meridional cross-sectional plan view of the tire on which the components are installed.

[0106] - Figure 3 For along Figure 2 A cross-sectional view of plane III-III', which shows Figure 1 The tire carcass reinforcement, and

[0107] - Figure 4 For similar Figure 1 The view compares the installation components of existing technologies with... Figure 1 The bending of the installation components. Detailed Implementation

[0108] The figure shows reference frames X, Y, and Z, which correspond to the typical axial direction (Y), radial direction (Z), and circumferential direction (X) of a tire or mounting assembly, respectively.

[0109] In the following description, the measurements were taken on unloaded and undressed tires, or on tire sections in the meridional plane.

[0110] Figure 1 A mounting assembly according to the invention, indicated by overall reference numeral 10, is shown. The mounting assembly 10 includes a tire 11 and a mounting support 100, the mounting support 100 including a rim 200. In this case, the tire 11 is inflated to a pressure ranging from 200 to 350 kPa, preferably 250 to 330 kPa, and in this case equal to 270 kPa.

[0111] Tire 11 has a generally torus shape about an axis of rotation R that is substantially parallel to the axial direction Y. Tire 11 is intended for use in passenger vehicles. In the various figures, tire 11 is depicted as new, that is, it has not yet been operated.

[0112] Tire 11 includes two sidewalls 30, each sidewall bearing markings indicating the size of tire 11, as well as speed ratings and speed designations. In this case, the nominal section width SW of tire 11 ranges from 225 to 315, preferably from 245 to 315, and is here equal to 225. Tire 11 also has a nominal aspect ratio AR ranging from 25 to 55, and here equal to 55. Tire 11 has a nominal rim diameter ranging from 18 to 23, and in this case equal to 18. Therefore, the sidewall height H of tire 11 is defined as SW x AR / 100 = 124 ≥ 95, preferably H ≥ 100.

[0113] According to the invention, the marking also includes a load index LI ranging from 98 to 116, which satisfies LI ≥ LI' + 1, where LI' is the load index of an overloaded tire of the same size according to the ETRTO 2019 standard manual. Preferably, LI' + 1 ≤ LI ≤ LI' + 4, or even LI' + 2 ≤ LI ≤ LI' + 4.

[0114] As shown in the section on passenger vehicle tires – metric tires (page 28) of the ETRTO 2019 standard manual, an overload capacity tire of size 225 / 55R18 has a load index of 102. Therefore, the load index LI of tire 11 satisfies LI ≥ 103, preferably 103 ≤ LI ≤ 106, even 104 ≤ LI ≤ 106, and in this case LI = 105. This load index of 105 corresponds to the load index of a high-load capacity tire of size 225 / 55R18 as shown in the ETRTO 2021 manual. Therefore, tire 11 is clearly of the high-load capacity type.

[0115] For this size, the ETRTO 2019 standard manual, in the section on passenger vehicle tires - metric tires (page 28), specifies the rim width designation as 7. Therefore, the rim 200 for mounting assembly 10 is selected from:

[0116] - According to the ETRTO 2019 standard manual, the rim width designation is equal to the rim width designation measured for the tire size.

[0117] - The rim width designation is equal to the measured rim width designation for the tire size minus 0.5 for the rim.

[0118] - The rim width designation is equal to the rim width designation measured for the tire size plus 0.5 rim width.

[0119] In this case, the rim 200 of the mounting assembly 10 is a rim whose rim width designation is equal to the measured rim width designation for the tire size minus 0.5, and therefore equals 6.5 in this case. The rim 200 has a J-type profile and rim width A according to the ETRTO 2019 standard manual. In this case, the profile of the rim 200 is 6.5J type, and its rim width A (in mm) is equal to 165.10 mm.

[0120] refer to Figure 2The tire 11 includes a crown 12, which includes a tread 14 intended to contact the ground when the tire is in operation and a crown reinforcement 16 extending in the circumferential direction X within the crown 12. The tire 11 also includes a layer 18 that is airtight for inflation gas, which, when the tire 11 is mounted on a mounting support 100, is intended to define a closed internal cavity with respect to the mounting support 100 of the tire 11.

[0121] The crown reinforcement 16 includes a working reinforcement 20 and a ring reinforcement 22. The working reinforcement 16 includes at least one working layer, and in this case, two working layers, including a radially inner working layer 24 arranged radially inside the radially outer working layer 26. Of the radially inner layer 24 and the radially outer layer 26, the axially narrowest layer is the radially outer layer 26.

[0122] The hoop reinforcement 22 includes at least one hoop layer, in this case including a hoop layer 28.

[0123] The crown reinforcement 16 is radially covered by the tread 14. In this case, the ring reinforcement 22 (in this case, the ring layer 28) is arranged radially outside the working reinforcement 20, and thus is radially inserted between the working reinforcement 20 and the tread 14.

[0124] Two sidewalls 30 extend radially inward from the crown 12. The tire 11 also has two bead 32 located radially inside the sidewalls 30. Each sidewall 30 connects each bead 32 to the crown 12.

[0125] Tire 11 includes a carcass reinforcement 34 anchored in each bead 32 and, in this case, wound around a circumferential reinforcing element 33 (in this case, a bead line). The carcass reinforcement 34 extends radially in each sidewall 30 and axially in the crown 12, radially inward of the crown reinforcement 16. The crown reinforcement 16 is radially disposed between the tread 14 and the carcass reinforcement 34. The carcass reinforcement 34 includes at least one carcass layer 36, in this case, a first carcass layer 36 and a second carcass layer 37. The first carcass layer 36 and the second carcass layer 37 each extend radially inward of the crown reinforcement 16 in each sidewall 30 and the crown 12.

[0126] The hoop reinforcement 22 (in this case, the hoop layer 28) is defined axially by two axial edges 281, 282 and includes one or more hoop filamentary reinforcement elements that are circumferentially helically wound between the respective axial edges 281, 282 along a principal direction, which forms an angle AF with the circumferential direction X of the tire 10 with an absolute value less than or equal to 10°, preferably less than or equal to 7°, and more preferably less than or equal to 5°. In this case, AF = -5°.

[0127] The radial inner working layer 24 and the radial outer working layer 26 are each defined axially by their respective two axial edges 241, 242, 261, and 262. The radial inner working layer 24 has an axial width of T1 = 174.00 mm, and the radial outer working layer 26 has an axial width of T2 = 160.00 mm, making the radial outer working layer 26 the narrowest working layer in the axial direction.

[0128] Note that SW = 225 and T2 = 160 satisfy the following relationship: T2 ≥ SW – 75, preferably T2 ≥ SW – 70, and T2 ≤ SW – 27, preferably T2 ≤ SW – 30.

[0129] like Figure 1 As shown, the mounting assembly 10 satisfies that the tire 11 has a sidewall that straightens in the radial direction. Specifically, the ratio T2 / A satisfies 0.85≤T2 / A≤1.00, preferably 0.90≤T2 / A≤1.00, more preferably 0.93≤T2 / A≤0.97, and in this case T2 / A=0.97.

[0130] Working layers 24 and 26 each include working filament reinforcing elements that extend axially from one axial edge 241, 261 of each working layer 24 and 26 to the other axial edge 242, 262, respectively, along a principal direction substantially parallel to each other. These principal directions form opposite-oriented angles AT1 and AT2 with the circumferential direction X of the tire 10, respectively. The absolute values ​​of these angles AT1 and AT2 are strictly greater than 10°, preferably ranging from 15° to 50°, and more preferably from 20° to 35°. In this case, AT1 = -26° and AT2 = +26°.

[0131] The first carcass layer 36 and the second carcass layer 37 are each defined axially by two axial edges 361, 362, 371, and 372 and respectively include carcass fabric filamentary reinforcing elements 360 and 370. The carcass fabric filamentary reinforcing elements 360 and 370 extend axially from one axial edge 361 and 371 to another axial edge 362 and 372 in the principal direction D3. The principal direction D3 forms an angle AC with the circumferential direction X of the tire 10. The absolute value of the angle AC ranges from 80° to 90°, and in this case, AC = +90°.

[0132] The first carcass layer 36 is wound around each circumferential reinforcing element 33 of each bead 32, such that the axially inner portions 3611, 3621 of the first carcass layer 36 are axially arranged inside the axially outer portions 3612, 3622 of the first carcass layer 36, and each axial end portion 361, 362 of the first carcass layer 36 is radially arranged outside each circumferential reinforcing element 33. Each axial end portion 371, 372 of the second carcass layer 37 is radially arranged inside each axial end portion 361, 362 of the first layer, and is axially arranged between the axially inner portions 3611, 3612 and the axially outer portions 3621, 3622 of the first carcass layer 36.

[0133] Each axial end 361, 362 of the first carcass ply 36 is radially arranged inside the equator E of the tire. More specifically, each axial end 361, 362 of the first carcass ply 36 is arranged at a radial distance RNC less than or equal to 30 mm from the radially inner end 331 of each circumferential reinforcing element 33 of each bead 32. In this case, RNC = 23 mm.

[0134] Working layers 24, 26, ring layer 28, and carcass layer 36 each include a calendered matrix for the filamentary reinforcing elements of the respective layer. Preferably, the calendered matrix is ​​a polymer, more preferably an elastomer, such as those commonly used in the tire industry.

[0135] Each hoop-shaped filamentary reinforcing element typically comprises two multifilament strands, each composed of a yarn of aliphatic polyamide (nylon in this case) monofilament with a count of 140 tex. These two multifilament strands are each helically twisted in one direction at 250 turns / meter, and then helically twisted together in the opposite direction at 250 turns / meter. The two multifilament strands are spirally wound around each other. As a variant, a hoop-shaped filamentary reinforcing element may be used, comprising one multifilament strand composed of a yarn of aliphatic polyamide (nylon in this case) monofilament with a count of 140 tex and another multifilament strand composed of a yarn of aramid (aramid in this case) monofilament with a count of 167 tex. These two multifilament strands are each helically twisted in one direction at 290 turns / meter, and then helically twisted together in the opposite direction at 290 turns / meter. The two multifilament strands are spirally wound around each other. In another variant, a hoop-like reinforcing element may be used, comprising two multifilament strands composed of yarns of aramid (in this case, aramid) monofilaments each with a count of 330 tex, and one multifilament strand composed of yarns of aliphatic polyamide (in this case, nylon) monofilaments with a count of 188 tex. Each of these multifilament strands is helically twisted in one direction at 270 turns / meter, and then helically twisted together in the opposite direction at 270 turns / meter. These three multifilament strands are spirally wound around each other.

[0136] Typically, high-load use leads to a decrease in the acceptable speed limit of a tire and a deterioration in its performance, such as lateral stiffness. Therefore, by using one or more high-modulus ring-shaped filamentary reinforcing elements, such as those described in the last two variants above (including one or more aramid strands), the acceptable speed limit of a tire can be increased and its performance, particularly its lateral stiffness, improved.

[0137] Each working filament reinforcing element is an assembly 4.26 consisting of four steel monofilaments, comprising an inner layer with two monofilaments and an outer layer with two monofilaments, the two monofilaments of the outer layer being helically wound around the inner layer (e.g., in direction S) with a twist pitch of 14.0 mm. Such an assembly 4.26 has a breaking force of 640 N and a diameter of 0.7 mm. Each steel monofilament has a diameter of 0.26 mm and a mechanical strength of 3250 MPa. As a variant, an assembly of six steel monofilaments with a diameter of 0.23 mm can also be used, comprising an inner layer with two monofilaments and an outer layer with four monofilaments, the two monofilaments of the inner layer being helically wound around each other in a first direction (e.g., the Z direction) with a twist pitch of 12.5 mm, and the four monofilaments of the outer layer being helically wound around the inner layer in a second direction (e.g., the S direction) opposite to the first direction with a twist pitch of 12.5 mm.

[0138] like Figure 3 As shown, each of the first and second matrix layers 36 and 37, respectively, comprises an assembly of at least two multifilament strands 363, 364 and 373, 374. Each multifilament strand 363, 364, 373, 374 is selected from polyester multifilament strands, aramid multifilament strands, and aliphatic polyamide multifilament strands, preferably from polyester multifilament strands and aramid multifilament strands. In this case, the assembly is selected from assemblies having two polyester multifilament strands and assemblies having both polyester and aramid multifilament strands, and in this case, it is composed of two PET multifilament strands, each helically twisted in one direction at 420 turns / meter and then helically twisted together in the opposite direction at 420 turns / meter. Each of these multifilament strands has a yarn count of 114 tex, such that the total yarn count of the assembly is less than or equal to 475 tex, and in this case, equal to 228 tex.

[0139] Each of the filamentary reinforcing elements 360 and 370 of the body fabric has an average diameter D1 and D2, respectively, expressed in mm, satisfying that D1 ≤ 0.90 mm and D2 ≤ 0.90 mm, preferably D1 ≤ 0.85 mm and D2 ≤ 0.85 mm, more preferably D1 ≤ 0.75 mm and D2 ≤ 0.75 mm, and satisfying that D1 ≥ 0.55 mm and D2 ≥ 0.55 mm, preferably D1 ≥ 0.60 mm and D2 ≥ 0.60 mm. In this case, D1 = D2 = 0.62 mm.

[0140] A tire according to a second embodiment of the present invention will now be described.

[0141] Compared to the first embodiment, the tire according to the second embodiment has a nominal section width SW of 255, a nominal aspect ratio AR of 40, a nominal rim diameter of 21, and a sidewall height H defined as SW x AR / 100 = 102 (which is greater than or equal to 95). As shown in the section on passenger vehicle tires – metric tires (page 34) of the ETRTO 2019 standard manual, an overload capacity tire of size 255 / 40R21 has a load index of 102. Therefore, the load index LI of the tire according to the second embodiment satisfies LI ≥ 103, preferably 103 ≤ LI ≤ 106, even 104 ≤ LI ≤ 106, and in this case LI = 105. This load index of 105 corresponds to the load index of a high-load capacity tire of size 255 / 40R21 as shown in the ETRTO 2021 manual. Therefore, the tire according to the second embodiment is effectively a high-load capacity type.

[0142] Unlike the tire according to the first embodiment, the tire according to the second embodiment satisfies 0.88≤H / LI≤0.98, and in this case H / LI=0.97.

[0143] Comparative Test

[0144] Tension simulation

[0145] To demonstrate the advantages of the invention, the inventors simulated the tension of each filamentary reinforcing element in the tire carcass of various tires.

[0146] For each of these tests, the tension of each carcass filamentary reinforcement element of a tire inflated to a pressure equal to 2.8 bar and subjected to a load, said load being much higher than the load used in the load / speed performance test described in Annex VII of UN / ECE Regulation No 30.

[0147] Simulations were performed on various tires with the following sizes: 255 / 35R20, 235 / 60R18, and 255 / 60R18, resulting in:

[0148] - The tire according to the invention (represented by the designations INV1, INV2) has a carcass reinforcement comprising a first carcass layer and a second carcass layer, wherein each axial end of the second carcass layer is radially disposed inside each axial end of the first layer and axially disposed between the axial inner portion and the axial outer portion of the first carcass layer (first configuration).

[0149] - The tire according to the invention (represented by the designations INV1', INV2') has a carcass reinforcement comprising a first carcass layer and a second carcass layer, wherein each axial end of the second carcass layer is radially disposed inside each axial end of the first layer and axially disposed outside each axially outer portion of the first carcass layer (second configuration).

[0150] - Tire (COMP0) includes a carcass reinforcement similar to tires INV1 and INV2, but with a sidewall height H strictly less than 95, and

[0151] - The tire consists of a single carcass reinforcement (COMP1, COMP2) and has a sidewall height H (COMP0') that is strictly less than 95.

[0152] For tires comprising a single carcass layer, the tension of each carcass filamentary reinforcement element is measured at the end of the single carcass layer, while for tires comprising two carcass layers, the tension of each carcass filamentary reinforcement element is measured at the end of the first carcass layer where the circumferential reinforcement element around each bead forms a winding.

[0153] The results of these simulations are summarized in Table 1 below.

[0154] Table 1

[0155]

[0156] First, it demonstrates that, compared to tires with a single carcass layer, the tension of the carcass filamentary reinforcement element is significantly reduced in the case of tires with a first carcass layer and a second carcass layer. Therefore, by utilizing the first and second carcass layers, the tension of the carcass reinforcement element is controlled.

[0157] Furthermore, this control over the tension of the carcass reinforcement has proven necessary only for tires with a sidewall height greater than or equal to 95. This is because even in the case of a carcass reinforcement comprising a single carcass ply, the tension of the carcass reinforcement in tires with a sidewall height strictly less than 95 is still controlled.

[0158] It should also be noted that for a given number of carcass plies, the higher the sidewall, the greater the tension. Therefore, if it is desired to reduce the tension of the carcass reinforcement to a reasonable level by arranging the carcass reinforcement according to the first configuration, the sidewall height will be limited to a value less than or equal to 155. For sidewall heights strictly greater than 155, as explained above, it is preferable to arrange the carcass reinforcement according to the second configuration to reduce this tension.

[0159] Operational test simulation

[0160] To demonstrate the advantages of the first configuration of the carcass reinforcement arrangement over the second configuration for tires with a sidewall height of 155 or less, the inventors simulated tire operation.

[0161] For each of these tests, simulations were performed similar to the load / speed performance tests described in Annex VII of UN / ECE Regulation No. 30, but under more demanding load and pressure conditions. Simulations were conducted on a variety of tires with the following sizes: 255 / 40R21, 235 / 60R18, and 255 / 60R18, such that:

[0162] - The tire (indicated by markings INV1, INV2, INV3) includes an arrangement of carcass reinforcements according to the first configuration.

[0163] - The tire (indicated by markings INV1', INV2', INV3') includes the arrangement of carcass reinforcements according to the second configuration.

[0164] In these simulations, the maximum volumetric energy dissipation DNRJ (expressed as daN / mm2) of a portion of the calendered matrix of the first and second carcass layers was recorded. This portion is located axially between the first and second carcass layers in the tire sidewall. The higher this value, the greater the energy dissipation of the tire structure and the higher the temperature rise. The results of these simulations are summarized in Table 2 below.

[0165] Table 2

[0166]

[0167]

[0168] It should be noted that the arrangement of the carcass reinforcement according to the first configuration is advantageous for reducing energy dissipation, while the arrangement of the carcass reinforcement according to the second configuration cannot reduce energy dissipation to the same extent. This is particularly advantageous for sidewall heights of H ≤ 130, preferably H ≤ 120, and more preferably H ≤ 110. This is because, for such sidewall heights, the maximum volumetric energy dissipation (DNRJ) is relatively high, while using the arrangement of the carcass reinforcement according to the first configuration allows energy dissipation to be significantly reduced to an acceptable level (in absolute terms).

[0169] Even though the energy dissipation (in absolute terms) for a sidewall height greater than 130 is less than the energy dissipation for a sidewall height less than or equal to 130, the arrangement of the carcass reinforcement in the first configuration still allows for a reduction of approximately 50% in energy dissipation.

[0170] Static testing

[0171] To illustrate the effect of straightening the tire sidewall (although this is advantageous, it is optional within the scope of this invention), Figure 4 The results of static compression tests are shown on a 225 / 55R18 tire (shown on the left) and the aforementioned tire (shown on the right). The 225 / 55R18 tire is the same size as the aforementioned tire, but its ratio T2 / A is 1.05, while the ratio T2 / A of the aforementioned tire is 0.97. At a pressure of 250 kPa, the load applied to each tire is 925 kg.

[0172] It should be noted that the deflection of the left tire is much greater than that of the right tire. This is because the distance DR1 from the axis of rotation R to the ground in the left tire is less than the distance DR2 from the axis of rotation R to the ground in the right tire.

[0173] It should be noted that the sidewall of the right tire is straighter radially than that of the left tire. This can be observed by comparing the distances DF1 and DF2 between the outer surface of the sidewall on opposite sides of the contact patch and the plane SA, where plane SA is perpendicular to the tire's axis of rotation R and passes through the bearing surface of the rim that defines the axial width A of the rim. This can also be observed by comparing the distances DF1' and DF2' between the outer surface of the sidewall and the vertical plane SA at the same radial point on each sidewall perpendicular to the contact patch. It can be observed that DF1 > DF2, and DF1' > DF2'.

[0174] The present invention is not limited to the above-described embodiments.

Claims

1. A tire (11) for a passenger vehicle, comprising a crown (12), two beads (32), two sidewalls (30), and a carcass reinforcement (34) anchored in each bead (32), each sidewall connecting each bead (32) to the crown (12), the crown (12) comprising a crown reinforcement (16) and a tread (14), the carcass reinforcement (34) extending radially inward of the crown reinforcement (16) in each sidewall (30) and the crown (12). Its features are, The load index LI of the tire (11) satisfies LI≥LI'+1, where LI' is the load index of an overloaded tire of the same size according to the ETRTO 2019 standard manual; the sidewall height H of the tire (11) is defined as H=SW xAR / 100 and satisfies H≥95, where SW is the nominal cross-sectional width of the tire according to the ETRTO 2019 standard manual and AR is the nominal aspect ratio; the carcass reinforcement (34) includes a first carcass layer (36) and a second carcass layer (37); and SW ranges from 245 to 315, AR ranges from 30 to 45, the nominal rim diameter ranges from 18 to 23, the load index LI ranges from 98 to 116, and 0.88≤H / LI≤0.98, Each axial end of the first carcass layer forming the winding is located at a radial distance of less than or equal to 30 mm from the radially inner end of each circumferential reinforcing element of each bead, and the second carcass layer (37) does not form the winding. Wherein, 95≤H≤155 and the first carcass layer (36) is wound around the circumferential reinforcing element (33) of each bead, such that the axial inner portion (3611, 3621) of the first carcass layer (36) is axially arranged inside the axial outer portion (3612, 3622) of the first carcass layer (36), and each axial end (361, 362) of the first carcass layer is radially arranged outside each circumferential reinforcing element (33), and each axial end (371, 372) of the second carcass layer (37) is radially arranged inside each axial end (361, 362) of the first carcass layer (36) and arranged as follows: - Located axially between the inner axial portion (3611, 3621) and the outer axial portion (3612, 3622) of the first carcass layer (36), or - Located axially inside the inner portion (3611, 3621) of the first carcass layer (36); or Wherein, H > 155 and the first carcass layer (36) is wound around the circumferential reinforcing element (33) of each bead, such that the axial inner portion (3611, 3621) of the first carcass layer (36) is axially arranged inside the axial outer portion (3612, 3622) of the first carcass layer, and such that each axial end (361, 362) of the first carcass layer (36) is radially arranged outside each circumferential reinforcing element (33), and each axial end (371, 372) of the second carcass layer (37) is radially arranged inside each axial end (361, 362) of the first carcass layer (36) and axially arranged outside each axial outer portion (3612, 3622) of the first carcass layer (36).

2. The tire (11) according to claim 1, wherein, LI'+1≤LI≤LI'+4.

3. The tire (11) according to any one of the preceding claims, wherein, The first carcass layer (36) and the second carcass layer (37) are each defined axially by two axial edges (361, 362, 371, 372) of the carcass layer, and include carcass fabric filamentary reinforcing elements (360, 370) extending axially from one axial edge of the carcass layer to the other axial edge in a principal direction, the principal direction forming an angle with the circumferential direction (X) of the tire (11) with an absolute value ranging from 80° to 90°.

4. The tire (11) according to claim 1, wherein, One of the first carcass layer (36) and the second carcass layer (37) is wound around the circumferential reinforcing element (33) of each bead, such that the axially inner portion (3611, 3621) of the first carcass layer (36) is arranged axially inside the axially outer portion (3612, 3622) of the first carcass layer (36), and such that each axial end (361, 362) of the first carcass layer (36) is arranged radially outside each circumferential reinforcing element (33).

5. The tire (11) according to claim 4, wherein, Each axial end (361, 362) forming the wound carcass layer is arranged radially inside the equator (E) of the tire.

6. The tire (11) according to claim 1, wherein its size and load index L1 are selected from the following size and load indices: 235 / 45R21 104, 235 / 45ZR21 104, 285 / 45R22 116, 285 / 45ZR22 116, 245 / 40R19 101, 245 / 40ZR19 101, 255 / 40R20 104, 255 / 40ZR20 104, 245 / 40R21 103, 245 / 40ZR21 103, 255 / 40R21 105, 255 / 40ZR21 105, 265 / 40R21 108, 265 / 40ZR21 108, 255 / 40R22 106, 255 / 40ZR22 106, 275 / 35R21 105, 275 / 35ZR21 105, 285 / 35R21 108, 285 / 35ZR21 108, 295 / 35R22 111, 295 / 35ZR22 111, 275 / 35R23 108, 275 / 35ZR23 108.

7. The tire (11) according to claim 1, wherein, The crown reinforcement (16) includes a working reinforcement (20), which includes a radially inner working layer (24) and a radially outer working layer (26) arranged radially outside the radially inner working layer (24).

8. The tire (11) according to claim 1, wherein, The crown reinforcement (16) includes a hoop reinforcement (22) which is axially defined by two axial edges (281, 282) and includes at least one hoop filament reinforcement element which is circumferentially helically wound to extend axially between the axial edges (281, 282) of the hoop reinforcement (22).

9. An installation component (10) comprising: - Including mounting support (100) for the rim (200), and - A tire (11) according to claim 1, mounted on the rim (200).

10. A passenger vehicle comprising at least one tire (11) according to claim 1 or a mounting assembly (10) according to claim 9.

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