Tyre comprising a complex tread with a durable interface

Abstract

The tyre (10) comprises a tread (14) comprising a tread layer (52) comprising an axially central portion (P0c) and an axially lateral portion (P1c, P2c). The axially central portion (P0c) is in contact with the axially lateral portion (P1c, P2c) via an interface (56) extending radially from a radially exterior interface point (I1, I2). The axial distance E1 between the radially exterior interface point (I1, I2) and the axial end (701, 702) of the axially narrowest crown layer (70) is such that E1 ≥ 0.05 x L, where L is the axial width of the axially narrowest crown layer (70). The axial distance (D1, D2) between the radially exterior interface point (I1, I2) and each edge (19, 21) of each adjacent main circumferential cut (22, 24) is greater than or equal to 5 mm.

Description

Tire comprising a complex tread with a durable interface

[0001] The present invention relates to a tire, in particular for a passenger vehicle. By tire is meant a bandage intended to form a cavity by cooperating with a support element, for example a rim, this cavity being capable of being pressurized to a pressure higher than atmospheric pressure. A tire according to the invention has a structure of substantially toroidal shape of revolution around a main axis of the tire.

[0002] Known from the state of the art are tires comprising a tread comprising a tread layer comprising an axially central portion of the tread layer and first and second axially lateral portions of the tread layer arranged axially outside and on either side of the axially central portion of the tread layer. In order to optimize certain performances of the tire, for example the rolling resistance and / or the drift rigidity, the axially central portion of the tread layer and each first and second axially lateral portion of the tread layer respectively comprise a central material and first and second lateral materials different from each other.

[0003] After use, the appearance of a separation at the interface between the axially central portion and each first and second axially lateral portion of the tread layer was noted on this tire, and a thickness difference between the axially central portion and each first and second axially lateral portion of the tread layer was noted, indicating a difference in the wear rate between these portions.

[0004] The invention aims to eliminate the occurrence of cracks and thickness shifts.

[0005] For this purpose, the subject of the invention is a tire comprising a crown comprising a tread carrying a tread surface and a crown reinforcement arranged radially inside the tread, the crown reinforcement comprising an axially narrowest crown layer, the tread comprising a tread layer comprising an axially central portion of the tread layer and an axially lateral portion of the tread layer arranged axially outside the axially central portion of the tread layer, the axially central portion and the axially lateral portion of the tread layer respectively comprise a central material and a lateral material, the central material being different from the lateral material, the axially central portion of the tread layer being in contact with the axially lateral portion of the tread layer via an interface extending radially from a radially outer interface point of the tread surface, the tread comprising main circumferential cutouts having a depth greater than or equal to 50% of the tread height and ribs, each rib being delimited axially by at least one of the main circumferential cutouts, the interface is arranged in one of the ribs,tire in which the axial distance E1 between the radially outer interface point and the axial end of the axially narrowest crown layer located on the same side of the median plane as the interface is such that E1 > 0.05 x L with L the axial width of the axially narrowest crown layer, and the axial distance between the radially outer interface point and each edge of the or each main circumferential cutout adjacent to the interface is greater than or equal to 5 mm.,

[0006] The tire according to the invention makes it possible to eliminate the appearance of cracks and thickness shifts.

[0007] The distance E1 makes it possible to position the radially outer interface point in a protected zone because it is far from a significant bending zone of the crown corresponding to the zone in which the axial end of the axially narrowest layer of the crown reinforcement is located. Indeed, axially outside this end, the stiffness of the crown is relatively reduced whereas axially inside this end, the stiffness of the crown is relatively high. This difference in stiffness generates stresses which can cause cracking of the interface if the latter is arranged close to the bending zone.

[0008] Furthermore, the inventors understood that local wear responded to a rule according to which a portion of the crown having a relatively high rigidity (here the portion axially inside the end) compared to its neighboring portions wore more quickly than a portion of the crown having a relatively low rigidity (here the or each portion axially outside the end) compared to its neighboring portions. This difference in rigidity, in addition to causing the initiation of cracks described above, leads to non-homogeneous wear in the vicinity of the interface and to the appearance of a thickness shift. The invention makes it possible, thanks to the particular positioning of the interface relative to the end of the axially narrowest crown layer, to avoid the appearance of the thickness shift between the axially central portion and the axially lateral portion(s) by reducing the difference in rigidity in the vicinity of the interface.

[0009] Of course, E1 and L are expressed in the same unit of measurement, for example in mm.

[0010] The fact that the interface extends into one of the ribs reduces the risk of ozone attack on the interface, which further reduces the risk of cracking. Indeed, once attacked by ozone, the interface is weakened and much more likely to crack. However, in many tires, each material of the tread layer includes at least one antiozonant, the quantity of which in the vicinity of the interface is all the greater as the thickness of the tread layer increases, which effectively protects the interface against ozone attack. An interface that would be positioned at the bottom of the main circumferential cut is only protected by a very limited quantity of antiozonant due to the reduced thickness of the tread layer at this location and would therefore be very exposed to the risk of cracking in the long term.In the case where each material is devoid of anti-ozonant agent, the positioning of the interface is even more essential to avoid the risk of cracking.

[0011] By positioning the interface sufficiently far from the or each main circumferential cut adjacent to the interface, the interface is moved away from each adjacent main circumferential cut and the risk associated with ozone attack is reduced as described above. Indeed, by positioning the interface sufficiently far from the or each main circumferential cut adjacent to the interface, the risk of having an interface present at the bottom of the main circumferential cut on certain tires for which control of the manufacturing tools, in particular of the wearing course, would be insufficient to guarantee a position outside the or each main circumferential cut adjacent to the interface.

[0012] The wearing course is intended to come into contact with the ground when the tire is new and at least until a predetermined wear threshold is reached, for example a regulatory wear threshold. Such a regulatory wear threshold is indicated in particular by the presence of wear indicators in the tread. A layer that comes into contact with the ground when the tire has a level of wear above the regulatory wear threshold is not a wearing course.

[0013] The axially central portion of the wearing course comprises the plane median of the tire.

[0014] A rib is a portion of the tread that is raised in the radial direction as opposed to a cutout, which is set back in the radial direction. Because of their delimitation by at least one main circumferential cutout, each rib extends substantially circumferentially. A rib may be continuous circumferentially or circumferentially discontinuous because it is interrupted by cutouts. A distinction will be made between so-called central ribs, delimited axially by two adjacent main circumferential cutouts, and so-called lateral ribs, delimited axially by an adjacent main circumferential cutout and by one of the axial edges of the tread surface. Each lateral rib is the axially outermost rib of the tread on each side of the median plane of the tire.

[0015] Conventionally, the tread surface is delimited axially by first and second axial edges which coincide respectively with the first and second axial edges of the tread. The first and second axial edges are determined on a tire mounted on a nominal rim and inflated to the nominal pressure within the meaning of the ETRTO 2023 standard manual. The first and second axial edges are arranged on either side of the median plane of the tire and formed by lines substantially parallel to the circumferential direction of the tire. In the case of an obvious boundary between the tread surface and the rest of the tire, the first and second axial edges are determined simply.In the case where the tread surface is continuous with the outer surfaces of the tire sidewalls, the first and second axial edges are usually determined by loading the tire to 80% of its load capacity according to the ETRTO 2023 standard manual and the first and second axial edges are identified as the axial limits of the tread in contact with the ground.

[0016] A cutout or a portion of a cutout has two main characteristic dimensions: a width and a curvilinear length such that the curvilinear length is at least twice the width. A cutout or a portion of a cutout is therefore delimited by at least two main lateral faces determining its curvilinear length and connected by a base, the two main lateral faces being distant from each other by a non-zero distance, called the width of the cutout or of the portion of the cutout.

[0017] The principal direction of a cut is the direction along which the curve equidistant from each of the edges of the cut passes to the radial dimension of the rolling surface. The curvilinear length is the length measured along this curve equidistant from each of the edges of the cutout to the radial dimension of the rolling surface, and this between each end of the cutout. The mean direction is the shortest curve joining the two ends of the cutout.

[0018] The width of a cut or a portion of a cut is, in the case where the cut or portion of a cut does not include a chamfer, on a new tyre, the distance between the two main lateral faces measured over the entire depth of the cut or portion. The width of a cut or a portion of a cut is, in the case where the cut or portion of a cut includes a chamfer, on a new tyre, the distance between the two main lateral faces measured over the entire depth of the cut or of the portion radially inside the chamfer. The width is measured substantially perpendicular to the main lateral faces. The minimum width of a cut or portion is the smallest width of the cut or portion concerned.

[0019] The depth of a cut or portion of a cut is, on a new tire, the radial distance between the bottom of the cut or portion and its projection onto the ground when the tire is rolling. The maximum depth of a cut or portion is the greatest of the depths of the cut or portion concerned.

[0020] The maximum value of the depths of the cutouts is called the tread height. Preferably, the maximum value of the depths of the main circumferential cutouts is called the tread height.

[0021] A cutout or portion of a cutout may be transverse or circumferential.

[0022] A transverse cutout or portion is such that the cutout or portion extends in a mean direction forming an angle strictly greater than 30°, preferably greater than or equal to 45° with the circumferential direction of the tire, i.e. forming an angle less than or equal to 60°, preferably strictly less than 45° with the axial direction of the tire. A transverse cutout or portion may be continuous, i.e. not be interrupted by a tread block or another cutout so that the two main lateral faces determining its length are uninterrupted over the length of the transverse cutout or portion.A cutout or a transverse portion may also be discontinuous, that is to say interrupted by one or more sculpture blocks and / or one or more cutouts so that the two main lateral faces determining its length are interrupted by one or more sculpture blocks and / or one or more cutouts.

[0023] A circumferential cutout or portion is such that the cutout or portion extends in a mean direction forming an angle less than or equal to 30°, preferably less than or equal to 10° with the circumferential direction of the tire, i.e. forming an angle strictly greater than 60°, preferably strictly greater than 80° with the axial direction of the tire. In the case of a continuous circumferential cutout, the two ends coincide with each other and are joined by a curve making a complete turn of the tire. A circumferential cutout may be continuous, i.e. not be interrupted by a tread block or another cutout so that the two main lateral faces determining its length are uninterrupted over the entire turn of the tire.A cutout or circumferential portion may also be discontinuous, i.e. interrupted by one or more tread blocks and / or one or more cutouts so that the two main lateral faces determining its length are interrupted by one or more tread blocks and / or one or more cutouts over the entire circumference of the tire.

[0024] The tire according to the invention has a substantially toric shape around an axis of revolution substantially coincident with the axis of rotation of the tire. This axis of revolution defines three directions conventionally used by those skilled in the art: an axial direction, a circumferential direction and a radial direction.

[0025] Axial direction means the direction substantially parallel to the axis of revolution of the tire, i.e. the axis of rotation of the tire.

[0026] Circumferential direction means the direction which is substantially perpendicular to both the axial direction and a radius of the tire (in other words, tangent to a circle whose center is on the axis of rotation of the tire).

[0027] Radial direction means the direction along a radius of the tire, that is to say any direction intersecting the axis of rotation of the tire and substantially perpendicular to this axis.

[0028] By median plane of the tire (noted M), we mean the plane perpendicular to the axis of rotation of the tire which is located at the axial midpoint of the two beads and passes through the axial center of the crown reinforcement.

[0029] By equatorial circumferential plane of the tire is meant, in a meridian section plane, the plane passing through the equator of the tire, perpendicular to the median plane and to the radial direction. The equator of the tire is, in a meridian section plane (plane perpendicular to the circumferential direction and parallel to the radial and axial directions) the axis parallel to the axis of rotation of the tire and located equidistant between the radially outermost point of the tread intended to be at contact with the ground and the radially innermost point of the tire intended to be in contact with a support, for example a rim.

[0030] Meridian plane means a plane parallel to and containing the axis of rotation of the tire and perpendicular to the circumferential direction.

[0031] By radially inner, respectively radially outer, is meant closer to the tire's axis of rotation, respectively further from the tire's axis of rotation. By axially inner, respectively axially outer, is meant closer to the tire's median plane, respectively further from the tire's median plane.

[0032] By bead is meant the portion of the tire intended to allow the tire to be attached to a mounting support, for example a wheel comprising a rim. Thus, each bead is in particular intended to be in contact with a hook on the rim allowing it to be attached.

[0033] Any interval of values ​​designated by the expression "between a and b" represents the domain of values ​​from more than a to less than b (i.e., excluding the limits a and b), while any interval of values ​​designated by the expression "from a to b" means the domain of values ​​from a to b (i.e., including the strict limits a and b).

[0034] Any angle made between two directions is the smallest of the angles made by those two directions with each other.

[0035] The tires are, in preferred embodiments of the invention, intended for passenger vehicles as defined within the meaning of the European Tyre and Rim Technical Organization or "ETRTO" standard, 2023. Such a tire has a section in a meridian section plane characterized by a section height H and a nominal section width or flange thickness S within the meaning of the European Tyre and Rim Technical Organization or "ETRTO" standard, 2023 such that the ratio H / S, expressed as a percentage, is at most equal to 90, and is at least equal to 20, and the nominal section width S is at least equal to 115 mm and at most equal to 385 mm. In addition, the hook diameter D, defining the diameter of the rim on which the tire is mounted, is at least equal to 12 inches and at most equal to 30 inches.

[0036] The tires are, in embodiments of the invention, so-called summer tires. By summer, we mean tires that are neither so-called 4-season or all-season tires, nor so-called winter tires. Thus, a summer tire does not have an M+S marking, nor a 3PMSF marking.

[0037] In other embodiments, for example in which the tread is devoid of ribs, the tires are so-called 4-season and / or winter tires. Winter tires are in particular identified by a marking M+S (M+S being the acronym for "Mud + Snow") and / or 3PMSF (3PMSF being the acronym for "3 Peak Mountain Snow Flake"). 4-season or all-season tires, due to their performance on snow, also have the M+S and / or 3PMSF markings.

[0038] Preferably, the axially central portion of the wearing course has an axial width strictly greater than the axial width of the or each axially lateral portion.

[0039] Advantageously, E1 > 0.07 x L and even more preferably E1 > 0.09 x L.

[0040] In preferred embodiments for further spacing the interface from each adjacent major circumferential cutout, the axial distance between the radially outer interface point and each edge of the or each major circumferential cutout adjacent to the interface is greater than or equal to 7 mm.

[0041] In a first embodiment, the wearing course comprises first and second axially lateral portions of the wearing course arranged axially outside and on either side of the axially central portion of the wearing course, each first and second axially lateral portion of the wearing course respectively comprises a first and second lateral material, the central material being different from each first and second lateral material, the axially central portion of the wearing course being in contact with each first and second axially lateral portion of the wearing course respectively via a first and a second interface, each first and second interface extending respectively radially from a first and second radially outer interface point of the running surface, each axial distance E1,E2 between each first and second radially outer interface point and each axial end of the axially narrowest crown layer located on the same side of the median plane as each first and second interface is such that E1 > 0.05 x L and E2 > 0.0.5 x L, each first and second interface is arranged respectively in a first and second rib and the axial distance between each first and second radially outer interface point and each edge of the or each main circumferential cutout adjacent to each first and second interface is greater than or equal to 5 mm.,

[0042] Thus, each first and second interface is spaced away from each adjacent main circumferential cut and the risk associated with ozone attack is reduced.

[0043] Advantageously, E1 > 0.07 x L and E2 > 0.07 x L and even more preferably E1 > 0.09 x L and E2 > 0.09.

[0044] Advantageously, E1 < 0.15 x L and E2 < 0.15 x L, preferably E1 < 0.13 x L and E2 < 0.13 x L and even more preferably E1 < 0.11 x L and E2 < 0.11 x L.

[0045] Advantageously, the axial distance between each first and second radially outer interface point and each edge of the or each main circumferential cutout adjacent to each first and second interface is greater than or equal to 7 mm.

[0046] Preferably, in the first embodiment, the main circumferential cutouts having a depth greater than or equal to 50% of the tread height comprise first and second axially outer main circumferential cutouts arranged axially on either side of the median plane of the tire, each first and second axially outer main circumferential cutout being, on the same side of a median plane respectively as each first and second interface, the axially outermost main circumferential cutout of the tread, each first and second interface is arranged: - in the rib adjacent to each first and second axially outer main circumferential cutout respectively, and - axially outside respectively each first and second axially outer main circumferential cutout.

[0047] The compromise resulting from the combination of the central material and the first and second lateral materials is optimized. Indeed, too high a proportion of the first and second lateral materials leads to significant functionalization of the wearing course, i.e. a shift in the compromise in favor of the performance of the first and second lateral materials. Conversely, too high a proportion of the central material leads to low functionalization of the wearing course, i.e. a shift in the compromise in favor of the performance of the central material.

[0048] Preferably, in this first embodiment, the first axially lateral portion of the wearing course extends axially: - from a first axial edge of the rolling surface arranged on the same side of the median plane as the first axially lateral portion, - up to the first interface, the second axially lateral portion of the wearing course extends axially: - from a second axial edge of the rolling surface arranged on the same side of the median plane as the second axially lateral portion, - up to the second interface.

[0049] Preferably, in this first embodiment, E1 > 13 mm and / or E2 > 13 mm, preferably E1 > 15 mm and / or E2 > 15 mm.

[0050] Regardless of the axial width L of the axially narrowest crown layer, it is preferable to significantly distance at least one of the first and second radially outer interface points from each axial end of the axially narrowest crown layer located on the same side of the median plane.

[0051] Preferably, in the first embodiment, the tangent to at least one of the first and second interfaces, preferably to each first and second interface, to each first and second radially outer interface point forms an angle greater than or equal to 30°, preferably 45° with the radial direction of the tire.

[0052] By presenting at least one of the first and second interfaces oriented in a direction distant from the radial direction, the risk of crack initiation on the surface in the radial direction is reduced and the risk of radial propagation of this possible crack is eliminated.

[0053] In a second embodiment, the wearing course comprises a single axially lateral portion and an axially central portion.

[0054] Advantageously, in this second embodiment, the main circumferential cutouts having a depth greater than or equal to 50% of the tread height comprise at least one axially outer main circumferential cutout, the axially outer main circumferential cutout being, on the same side of a median plane as the interface, the axially outermost main circumferential cutout of the tread, the interface is arranged: - in the rib adjacent to the axially outer main circumferential cutout, and - axially inside the axially outer main circumferential cutout or axially outside the axially outer main circumferential cutout.

[0055] The arrangement of the interface axially inside the axially outer main circumferential cutout makes it possible to more distinctly functionalize the side of the tire carrying the axially lateral portion of the tread layer relative to the other side carrying the axially central portion. For this purpose, preferably, the axially lateral portion of the tread layer is arranged on the same side of the median plane of the tire as the outer side of the tire and the axially central portion is arranged on the same side of the median plane of the tire as the inner side of the tire. By inner and outer sides, we mean that the tire is designed so that one of its sides is arranged on the inner side and the other of its sides is arranged on the outer side. This orientation imposed by the tire manufacturer ensures that the tire has the expected operation. Indeed, mounting a tire with an orientation different from that imposed by the manufacturer can lead to suboptimal behavior of the vehicle. By outer side, we mean the side of the tire entirely visible from the outside of the vehicle when the tire is mounted on the vehicle. By inner side, we mean the side of the tire facing the wheel arch of the vehicle on which it is mounted.Usually, the tire has a marking indicating the inner side and the outer side.

[0056] If we want to functionalize less distinctly the side of the tire carrying the axially lateral portion, the interface is arranged: - in the rib adjacent to the axially outer main circumferential cutout and - axially outside the axially outer main circumferential cutout.

[0057] Preferably, in the second embodiment, the axially central portion of the wearing course extends axially: - from a first axial edge of the rolling surface arranged on the opposite side relative to the median plane of the axially lateral portion, - up to the interface, and the axially lateral portion of the wearing course extends axially: - from a second axial edge of the rolling surface arranged on the same side of the median plane as the axially lateral portion of the rolling course, - up to the interface.

[0058] Preferably, in this second embodiment, E1 > 13 mm, preferably E1 > 15 mm.

[0059] Regardless of the axial width L of the axially narrowest crown layer, it is preferable to significantly distance the radially outer interface point from the axial end of the axially narrowest crown layer.

[0060] More preferably, in the case where the interface is arranged in the rib adjacent to the axially outer main circumferential cutout and arranged axially inside the axially outer main circumferential cutout, E1 > 25 mm, preferably E1 > 35 mm.

[0061] Preferably, in this second embodiment, the tangent to the interface at the radially outer interface point forms an angle greater than or equal to 30°, preferably 45° with the radial direction of the tire.

[0062] By presenting an interface oriented in a direction away from the radial direction, the risk of crack initiation on the surface in the radial direction is reduced and the risk of radial propagation of this possible crack is eliminated.

[0063] In preferred variants of the preceding preferred embodiments: - in the case where the tire comprises first and second axially lateral portions of the tread layer, the central material and each first and second lateral material respectively has a dynamic shear modulus G*C, G*1, G*2 such that G*1 G*C and G*2 G*C, each dynamic shear modulus G*C, G*1, G*2 being measured at 23°C at 10% deformation and at a frequency of 10 Hz according to the standard ASTM D 5992 - 96, - in the case where the tire comprises an axially lateral portion of the tread layer, the central material and the lateral material respectively have a dynamic shear modulus G*C, G*1 such that G*1 G*C, each dynamic shear modulus G*C, G*1 being measured at 23°C at 10% deformation and at a frequency of 10 Hz according to standard ASTM D 5992 - 96.

[0064] Thus, it will be possible to differentiate the rigidities of each first and second lateral material and of the central material or of the central material and of the lateral material depending on the desired performance compromise.

[0065] Thus, in certain embodiments, in the case where the tire comprises first and second axially lateral portions of the tread layer G*1 <G*C et G*2<G*C et dans le cas où le pneumatique comprend une portion axialement latérale de la couche de roulement G*1<G*C, le pneumatique présente un compromis de performance amélioré, par exemple avec une résistance au roulement relativement faible. Néanmoins, comme décrit précédemment, en raison de la différence de rigidité, la présence d’une portion axialement centrale plus rigide que la ou les portions axialement latérales adjacentes conduit, dans la plupart des configurations de l’état de la technique, à la formation d’un décalage d’épaisseur entre la portion axialement centrale et la ou chaque portion axialement latérale adjacente de la couche de roulement indiquant une différence de la vitesse d’usure entre ces portions.Unlike these configurations of the state of the art, the invention makes it possible, thanks to the particular positioning of the interface relative to the end of the axially narrowest crown layer, to avoid the appearance of the thickness shift between the axially portion. central and the axially lateral portion(s). Thus, the invention makes it possible to propose tires having an improved performance compromise, for example with reduced rolling resistance, without creating a thickness offset in the vicinity of the interface.

[0066] In other performance tradeoffs, we can also consider cases where G*1>G*C and G*2>G*C or even cases where G*1>G*C.

[0067] In some preferred embodiments, the first side material is identical to the second side material, and in particular G*1=G*2.

[0068] The complex shear modulus G* is a dynamic property well known to those skilled in the art and is measured on a Metravib VA4000 or DMA+450 type viscoanalyzer using specimens comprising a cured composition extracted from the tire. The response of the specimen subjected to alternating simple sinusoidal shear stress is recorded at a frequency of 10 Hz under determined temperature conditions (here 23°C) according to the ASTM D1349-99 standard. A strain amplitude sweep is carried out from 0.1% cc to 100% cc (forward cycle), then from 100% cc to 0.1% cc (return cycle), cc meaning peak-peak. The test piece is of cylindrical section as described in ASTM D 5992-96 (version reapproved in 2011, originally approved in 1996) in Figure X2.1 (circular embodiment) and has a diameter of 10 mm [0 to + 0.04 mm] and a thickness of 2 mm [1.83-2.33].The dynamic complex shear modulus G* is defined as the square root of the sum of the square of G' and the square of G” where G' represents the elastic modulus and G” represents the viscous modulus. The complex shear modulus G* is measured at 10% cc strain on the return cycle.

[0069] In preferred variants of the preceding preferred embodiments: - in the case where the tire comprises first and second axially lateral portions of the tread layer, G*1 / G*C < 85% and / or G*2 / G*C < 85%, preferably G*1 / G*C < 80% and / or G*2 / G*C < 80%, - in the case where the tire comprises an axially lateral portion of the tread layer, G*1 / G*C < 85%, preferably G*1 / G*C < 80%.

[0070] The difference in intrinsic rigidities between the central material and the lateral material or each first and second lateral material is increased. Thus, for example, the rolling resistance of the tire is further reduced while benefiting from the effects of the invention.

[0071] In preferred variants of the preceding preferred embodiments: - in the case where the tire comprises first and second axially lateral portions of the tread layer, G*1 / G*C > 40% and / or G*2 / G*C > 40%, - in the case where the tire includes an axially lateral portion of the tread layer, G*1 / G*C > 40%.

[0072] By over-differentiating the intrinsic rigidities of the central material and the lateral material or of each first and second lateral material, there is a risk of excessively promoting wear of the central portion.

[0073] In an embodiment making it possible, for example, to reduce the rolling resistance of the tire: - in the case where the tire comprises first and second axially lateral portions of the tread layer, 40% <G*1 / G*C < 70% et / ou 40% < G*2 / G*C < 70%, preferably 40% <G*1 / G*C < 60% et 40% < G*2 / G*C < 60%. - in the case where the tire includes an axially lateral portion of the tread layer, 40% <G*1 / G*C < 70%, de préférence 40% <G*1 / G*C < 60%.

[0074] In a first variant of this embodiment making it possible to reduce rolling resistance while maintaining drift rigidity: - in the case where the tire comprises first and second axially lateral portions of the tread layer, each first and second lateral material respectively has a maximum dynamic loss tanDMAX23-1, tanDMAX23-2, such that tanDMAX23-1 < 0.20 and / or tanDMAX23-2 < 0.20, preferably tanDMAX23-1 < 0.15 and / or tanDMAX23-2 < 0.15 and the core material has a maximum dynamic loss tanDMAX23-0 such that 0.40 < tanDMAX23-0 < 0.50, - in the case where the tire comprises an axially lateral portion of the tread layer, the lateral material has a maximum dynamic loss tanDMAX23-1 such that tanDMAX23-1 < 0.20, preferably tanDMAX23-1 < 0.15 and the central material has a maximum dynamic loss tanDMAX23-0 such that 0.40 < tanDMAX23-0 < 0.50.

[0075] In a second variant of this embodiment making it possible to maximize the reduction in rolling resistance: - in the case where the tire comprises first and second axially lateral portions of the tread layer, each first and second lateral material respectively has a maximum dynamic loss tanDMAX23-1, tanDMAX23-2, such that tanDMAX23-1 < 0.20 and / or tanDMAX23-2 < 0.20, preferably tanDMAX23-1 < 0.15 and / or tanDMAX23-2 < 0.15 and the core material has a maximum dynamic loss tanDMAX23-0 such that tanDMAX23-0 < 0.40, preferably tanDMAX23-0 < 0.35, - in the case where the tire comprises an axially lateral portion of the tread layer, the lateral material has a maximum dynamic loss tanDMAX23-1 such that tanDMAX23-1 < 0.20, preferably tanDMAX23-1 < 0.15 and the central material has a maximum dynamic loss tanDMAX23-0 such that tanDMAX23-0 < 0.40, preferably tanDMAX23-0 < 0.35.

[0076] In an embodiment making it possible to increase the drift rigidity of the tire and therefore improve its behavior: - in the case where the tire comprises first and second axially lateral portions of the tread layer, 50% < G*1 / G*C < 85% and / or 50% < G*2 / G*C < 85%, preferably 65% ​​< G*1 / G*C < 85% and 65% < G*2 / G*C < 85% and more preferably 70% < G*1 / G*C < 85% and 70% < G*2 / G*C < 85%. Even more preferably, 50% < G*1 / G*C < 80% and / or 50% < G*2 / G*C < 80%, preferably 65% ​​< G*1 / G*C < 80% and 65% < G*2 / G*C < 80% and more preferably 70% < G*1 / G*C < 80% and 70% < G*2 / G*C < 80%, - in the case where the tire comprises an axially lateral portion of the tread layer, 50% < G*1 / G*C < 85%, preferably 65% ​​< G*1 / G*C < 85% and more preferably 70% < G*1 / G*C < 85%. Even more preferably, 50% < G*1 / G*C < 80%, preferably 65% ​​< G*1 / G*C < 80% and more preferably 70% < G*1 / G*C < 80%.

[0077] In this embodiment for increasing the drift stiffness, the drift stiffness is favored to the detriment of rolling resistance in a variant in which: - in the case where the tire comprises first and second axially lateral portions of the tread layer, each first and second lateral material respectively has a maximum dynamic loss tanDMAX23-1, tanDMAX23-2, such that 0.30 < tanDMAX23-1 and / or 0.30 < tanDMAX23-2 and the central material has a maximum dynamic loss tanDMAX23-0 such that 0.50 < tanDMAX23-0, - in the case where the tire comprises an axially lateral portion of the tread layer, the lateral material has a maximum dynamic loss tanDMAX23-1 such that 0.30 < tanDMAX23-1 and the central material has a maximum dynamic loss tanDMAX23-0 such that 0.50 < tanDMAX23-0.

[0078] Each dynamic loss tanDMAX23 is yet another dynamic property well known to those skilled in the art and is measured on the same viscoanalyzer of the Metravib VA4000 or DMA+450 type using specimens comprising a composition cooked extracted from the tire. The response of the specimen subjected to a sinusoidal stress in alternating simple shear, at a frequency of 10 Hz under determined temperature conditions (here 23°C) according to the ASTM D1349-99 standard, is recorded. A strain amplitude sweep is carried out from 0.1% cc to 100% cc (forward cycle), then from 100% cc to 0.1% cc (return cycle), cc meaning peak-peak. The specimen has a cylindrical section as described in the ASTM D 5992-96 standard (version reapproved in 2011, initially approved in 1996) in figure X2.1 (circular embodiment) and has a diameter of 10 mm [0 to + 0.04 mm] and a thickness of 2 mm [1.83-2.33]. The tangent tanD of the phase angle D between the force exerted on the sample and its displacement reflects a dynamic loss and is equal to the ratio G” / G'.The maximum value tanDMAX of the tangent tanD of the phase angle D observed on the deformation return cycle is recorded.

[0079] In preferred embodiments, the tread height is in the range of 5.0 mm to 10.0 mm, preferably 6.0 mm to 8.0 mm.

[0080] In embodiments in which the main circumferential cutouts are relatively deep, each main circumferential cutout has a depth ranging from 4.0 mm to the tread height, preferably from 5.0 mm to the tread height, and more preferably from 5.5 mm to the tread height.

[0081] In embodiments in which the major circumferential cutouts are relatively deep, each major circumferential cutout has a depth greater than or equal to 75% of the tread height, preferably 90% of the tread height.

[0082] In embodiments in which the major circumferential cutouts are relatively wide major circumferential grooves, each major circumferential cutout has a minimum width greater than or equal to 3.0 mm, preferably greater than or equal to 5.0 mm, and more preferably ranging from 5.0 mm to 20.0 mm.

[0083] In first advantageous and optional variants in which the tread comprises a radially inner layer arranged radially inside the tread layer and distinct from the tread layer, the radially inner layer is arranged radially inside: - the axially lateral portion of the tread layer in the case where the tire comprises an axially lateral portion of the tread layer or of each first and second axially lateral portion of the tread layer in the case where the tire comprises first and second axially lateral portions of the wearing course, and - the axially central portion of the wearing course.

[0084] The radially inner layer makes it possible to optimize certain performances of the tire, for example rolling resistance, wet grip, behavior. Thus, by distinct from the rolling layer, we understand that the radially inner layer is formed in one or more materials different from the lateral material or from the first and second lateral materials.

[0085] In a first configuration of these first variants, the radially inner layer may be intended not to come into contact with the ground when the tire is rolling, at least until a regulatory wear threshold is reached. The radially inner layer will be referred to as a support layer. However, occasionally, i.e. over an axial length less than 10% of the axial length of the radially inner layer, the radially inner layer may be brought into contact with the ground, in particular due to the relative control of industrial processes. Preferably, the radially inner layer is in contact with a crown reinforcement of the tire, for example as described below.

[0086] In a second configuration of these first variants, the radially inner layer may be intended to come into contact with the ground when the tire is rolling before the tire reaches the regulatory wear threshold. The radially inner layer will be referred to as the worn tread layer as opposed to the new tread layer, which is the radially outermost tread layer and is intended to be in contact with the ground when the tire is in its new condition.

[0087] In second advantageous and optional variants, the tread comprises at least one radially inner layer, the or each radially inner layer being formed in the lateral material in the case where the tire comprises an axially lateral portion of the tread layer or in the first and / or in the second lateral material of the tread layer in the case where the tire comprises first and second axially lateral portions of the tread layer, the radially inner layer being arranged radially inside the axially central portion of the tread layer.

[0088] Thus, compared to the first variants, the number of tread materials is reduced. Preferably, the first side material is identical to the second side material.

[0089] In still other variants, the tread does not include a radially inner layer. Thus, the tread layer is directly in contact of the crown reinforcement of the tire, for example as described below.

[0090] In embodiments, the crown reinforcement comprising a working reinforcement, the axially narrowest layer is a layer of the working reinforcement.

[0091] Conventionally, the working reinforcement advantageously comprises at least one working layer, the or each working layer comprising wire reinforcement elements extending substantially parallel to each other in a direction forming an angle strictly greater than 10°, preferably ranging from 15° to 50° and more preferably ranging from 20° to 35° with the circumferential direction of the tire. The wire reinforcement elements are preferably metal wire elements.Preferably, in the embodiments in which the working reinforcement comprises a radially innermost working layer and a radially outermost working layer arranged radially outside the radially innermost working layer, the main direction in which each working cord reinforcement element of the radially innermost working layer extends and the main direction in which each working cord reinforcement element of the radially outermost working layer extends form, with the circumferential direction of the tire, angles of opposite orientations. The angles of opposite orientations may have equal or different absolute values.

[0092] Conventionally, the tire comprises a crown, two sidewalls, two beads, each sidewall connecting each bead to the crown. Also conventionally, the crown comprises the tread and the crown reinforcement arranged radially inside the tread. The tire also comprises a carcass reinforcement anchored in each bead and extending radially in each sidewall and axially in the crown radially inside the crown reinforcement.

[0093] In embodiments allowing the performance of so-called radial tires to be obtained, for example as defined by the ETRTO, the carcass reinforcement comprises at least one carcass layer, the or each carcass layer comprising carcass wire reinforcement elements, each carcass wire reinforcement element extending substantially in a main direction forming with the circumferential direction of the tire, an angle, in absolute value, ranging from 80° to 90°. Alternatively, it will be possible to have a variable angle ranging from 80° to 90° in at least a portion of the sidewall and strictly less than 80° in at least a portion of the crown as described for example in US20190152262.

[0094] Advantageously, the crown reinforcement comprises a hoop reinforcement delimited axially by two axial edges of the hoop reinforcement and comprising at least at least one circumferentially helically wound hoop wire reinforcement element so as to extend axially between the axial edges of the hoop reinforcement.

[0095] Preferably, the hoop reinforcement is arranged radially outside the working reinforcement.

[0096] Preferably, the or each hoop wire reinforcement element extends in a main direction forming, with the circumferential direction of the tire, an angle, in absolute value, less than or equal to 10°, preferably less than or equal to 7° and more preferably less than or equal to 5°.

[0097] By reinforcing element is meant an element allowing the mechanical reinforcement of the polymer matrix in which this reinforcing element is intended to be embedded. Preferably, each reinforcing element is wire-like, that is to say that each reinforcing element has a length at least 10 times greater than the largest dimension of its section regardless of the shape of the latter: circular, elliptical, oblong, polygonal, in particular rectangular or square or oval. In the case of a rectangular section, the wire-like reinforcing element has the shape of a strip.

[0098] The invention will be better understood on reading the following description, given solely as a non-limiting example and with reference to the drawings in which: - figure 1 is a view, in a meridian section plane, of a tire according to a first embodiment of the invention, - figure 2 is a detail view of an interface between an axially lateral part and an axially central part of the tread layer of the tire of figure 1, figure 3 is a top view of the tread of the tire of figure 1, - Figure 4 is a detailed view of the tread of the tire of Figures 1 to 3 illustrating certain transverse cutouts, Figure 5 is a detailed view of the tread of the tire of Figures 1 to 3 illustrating other transverse cutouts, - figure 6 is a view similar to that of figure 1 of a tire according to a second embodiment of the invention, and - figures 7 and 8 are views similar to those of figures 1 and 2 of a tire according to a third embodiment of the invention, - figures 9, 10 and 11 are views similar to those of figures 3, 4 and 5 respectively of a tire according to a fourth embodiment of the invention, and - figure 12 is a view similar to that of figures 3 and 9 of a tire according to a fifth embodiment of the invention.

[0099] In the figures relating to the tire, a reference X, Y, Z is shown corresponding to the usual axial (Y), radial (Z) and circumferential (X) directions of a tire.

[0100] Figures 1 to 5 show a tire according to the invention and designated by the general reference 10. The tire 10 has a substantially toric shape around an axis of revolution substantially parallel to the axial direction Y. The tire 10 is intended for a passenger vehicle and has dimensions 255 / 40 R20. In the various figures, the tire 10 is shown in new condition, that is to say not yet having been driven. The tire 10 has an inner side INT and an outer side EXT.

[0101] The tire 10 comprises a crown 12 comprising a tread 14 carrying a rolling surface 16 intended to come into contact with a ground when the tire 10 is rolling. The rolling surface 16 is delimited axially by first and second axial edges 18, 20. The tread 14 and the rolling surface 16 have an axial width LSR measured as the axial distance from the first axial edge 18 to the second axial edge 20.

[0102] The tread 14 comprises an axially central portion POb of the tread 14 and first and second axially lateral portions P1b, P2b of the tread 14 arranged axially outside the axially central portion POb on either side axially of the axially central portion POb of the tread 14.

[0103] The tread 14 comprises several main circumferential cutouts, here four main circumferential grooves, comprising first, second, third and fourth main circumferential cutouts respectively designated by the references 22, 24, 26, 28. The first and second main circumferential cutouts 22, 24 are arranged axially on either side of the median plane M of the tire 10 and are the axially outermost main circumferential cutouts of the tread 14 and below called axially outer main circumferential cutouts 22, 24.

[0104] The first axially lateral portion P1 b and the second axially lateral portion P2b are arranged respectively axially outside the first axially outer main circumferential cutout 22 and the second axially outer main circumferential cutout 24. The first axially lateral portion P1b extends axially from the first axial edge 18 of the tread surface 16 to the axially outer edge 19 of the first main circumferential cutout 22. The second axially lateral portion P2b extends axially from the second axial edge 20 of the tread surface 16 to the axially outer edge 21 of the second axially outer main circumferential cutout 24. The axially central portion POb of the tread 14 extends axially from the first axially lateral portion P1b of the tread 14 to the second axially lateral portion P2b of the tread 14.

[0105] Each main circumferential cutout 22 to 28 has a depth Hr ranging from 4.0 mm to the tread height Hs, preferably ranging from 5.0 mm to the tread height Hs and more preferably ranging from 5.5 mm to the tread height Hs. Each depth Hr is greater than or equal to 50%, preferably 75% and more preferably 90% of the tread height Hs. Here, Hs=6.5 mm, Hr=6.0 mm for each first and second axially outer main circumferential cutout 22, 24 and Hs=Hr=6.5 mm for each main circumferential cutout 26, 28. Each main circumferential cutout 22 to 28 respectively has a minimum width greater than or equal to 3.0 mm, preferably greater than or equal to 5.0 mm and more preferably ranging from 5.0 mm to 20.0 mm.

[0106] With reference to Figures 1 and 3, the axially central portion POb comprises central ribs and here first, second and third central ribs respectively designated by the references 32, 34, 36. Each central rib 32, 34, 36 is arranged axially between two of the adjacent main circumferential cutouts 22 to 28. Each central rib 32, 34, 36 comprises transverse cutouts 38, 38', 40, 40', 42 formed in the central ribs 32, 34, 36.

[0107] Each transverse cutout 38, 38', 40, 40', 42 extends between its first and second ends in a mean direction forming an angle respectively denoted A38, A38', A40, A40', A42 with the axial direction Y of the tire 10 such that A38=A38'=A40=A40'=A42=10°.

[0108] With reference to Figures 3 to 5, each transverse cutout 38 comprises two portions 381, 382 respectively having a depth H81, H82 such that H81=4.9 mm and H82=1.4 mm. Each transverse cutout 38' comprises a portion 381' having a depth H81'=4.9 mm. Each transverse cutout 40 comprises two portions 401, 402 respectively having a depth H01, H02 such that 1-101=1.4 mm and H02=4.9 mm. Each transverse cutout 40' comprises a portion 402' having a depth H02'=4.9 mm. Each transverse cutout 42 comprises two portions 421, 422 respectively having a depth H21, H22 such that 1-121=1.4 mm and H22=4.9 mm. Each portion 381, 382, ​​381', 401, 402, 402', 421, 422 has a minimum width less than or equal to 1.5 mm, preferably ranging from 0.2 mm to 1.5 mm and here equal to 0.4 mm.

[0109] Each first and second axially lateral portion P1b, P2b respectively comprises a first and a second lateral rib respectively designated by the reference 44, 46. The tread 14 comprises first and second transverse cutouts 48', 48”, 50', 50” formed at least in part in each first and second axially lateral portion P1b, P2b. The first transverse cutouts 48', 48” are arranged on the inner side INT of the tire 10. The second transverse cutouts 50', 50” are arranged on the outer side EXT of the tire 10.

[0110] Each first transverse cutout 48' extends in a mean direction forming an angle A48' equal to 10° with the axial direction Y and comprises a portion 48T having a maximum depth H481'=4.7 mm. Each first transverse cutout 48' also comprises a portion axially widened outside the portion formed in the first axially lateral portion P1b and having a width equal to 4.0 mm. Each first transverse cutout 48” extends in a mean direction forming an angle A48” equal to 10° with the axial direction Y and comprises two portions 481”, 482” having respectively a maximum depth H481”=4.7 mm and H482”=1.4 mm.

[0111] Each second transverse cutout 50', 50” extends in a mean direction forming an angle A50', A50” equal to 0° with the axial direction Y and comprises a portion 50T, 501” having a depth H50T, H501” equal to 4.7 mm. Each second transverse cutout 50', 50” also comprises a portion 502', 502” having a depth H502', H502” equal to 1.4 mm. Each second transverse cutout 50' also comprises a portion axially widened outside the portion formed in the second axially lateral portion P2b and having a width equal to 3.0 mm.

[0112] Each first and second transverse cutout 48', 48” has a minimum width less than or equal to 1.5 mm, preferably ranging from 0.2 mm to 1.5 mm and here equal to 0.4 mm. Each first and second transverse cutout 50', 50” has a minimum width greater than or equal to 1.5 mm, preferably ranging from 1.5 mm to 6.0 mm and here equal to 4.5 mm.

[0113] All the transverse cutouts described above, whether inclined or not, are provided with chamfers which are not shown.

[0114] Due to the presence of the various transverse cutouts previously described, the tread 14 has a volumetric notch rate equal to 25%, which gives it a good compromise between the external noise generated by the tire and grip on wet ground.

[0115] The tread 14 comprises a tread layer 52 and a radially inner layer 54 arranged radially inside the tread layer 52 and distinct from the tread layer 52.

[0116] The tread layer 52 comprises an axially central portion POc of the tread layer 52 and first and second axially lateral portions P1c, P2c of the tread layer 52 arranged axially outside and on either side of the axially central portion POc of the tread layer 52. The axially central portion POc of the tread layer 52 is at least partly arranged in the axially central portion POb of the tread 14. Each first and second axially lateral portion P1c, P2c of the tread layer 52 is at least partly arranged respectively in each first and second axially lateral portion P1b, P2b of the tread 14.

[0117] The radially inner layer 54 is arranged radially inside each first and second axially lateral portion P1c, P2c of the wearing course 52 and the axially central portion POc of the wearing course 52. The axially central portion POc of the wearing course 52 comprises the median plane M.

[0118] The axially central portion POc is in contact with each first and second axially lateral portion P1c, P2c respectively via a first and second interface 56, 58. Each first and second interface 56, 58 is arranged in each first and second axially lateral portion P1b, P2b of the tread 14 and here in each rib 44, 46 adjacent to each first and second axially outer main circumferential cutout 22, 24 respectively and arranged axially outside each first and second axially outer main circumferential cutout 22, 24 respectively.

[0119] The axially central portion POc of the wearing course 52 extends axially from the first interface 56 to the second interface 58. The first axially lateral portion P1c of the wearing course 54 extends axially from the first axial edge 18 arranged on the same side of the median plane M as the first axially lateral portion P1c of the wearing course 52 to the first interface 56. second axially lateral portion P2c extends axially from the second axial edge 20 arranged on the same side of the median plane M as the second axially lateral portion P2c of the wearing course 52 to the second interface 58.

[0120] The axially central portion POc has an axial width strictly greater than the axial width of each first and second axially lateral portion P1c, P2c.

[0121] The first axially outer main circumferential cutout 22 is, on the same side of the median plane M as the first interface 56, the axially outermost main circumferential cutout of the tread 14. The second axially outer main circumferential cutout 24 is, on the same side of the median plane M as the second interface 58, the axially outermost main circumferential cutout of the tread 14.

[0122] Each first and second interface 56, 58 extends radially respectively from a first and second interface point 11, 12 radially outside the rolling surface 16 to a first and second interface point I3, 14 radially inside each first and second interface 56, 58.

[0123] The axially central portion POc comprises a central material MO having a dynamic shear modulus G*C measured at 23°C at 10% strain and at a frequency of 10 Hz according to the ASTM D 5992-96 standard. Each first and second axially lateral portion P1c, P2c respectively comprises a first and second lateral material M1, M2 having respectively a dynamic shear modulus G*1, G*2 measured at 23°C at 10% strain and at a frequency of 10 Hz according to the ASTM D 5992-96 standard. The central material MO is different from each first and second lateral material M1, M2. In the embodiment described here, rolling resistance is favored over drift stiffness. The first and second lateral materials M1, M2 are identical here.

[0124] The dynamic shear moduli G*C, G*1, G*2 verify G*1 G*C and G*2 G*C and here G*1 <G*C et G*2<G*C. En outre, G*1 / G*C < 85% et G*2 / G*C < 85%, de préférence G*1 / G*C < 80% et G*2 / G*C < 80%. Également, G*1 / G*C >40% and G*2 / G*C > 40%. Here, 40% <G*1 / G*C < 70% et / ou 40% < G*2 / G*C < 70%, de préférence 40% <G*1 / G*C < 60% et 40% < G*2 / G*C < 60%. Dans ce mode de réalisation, G*1=G*2=1 ,35 MPa, G*C=2,66 MPa et G*1 / G*C=G*2 / G*C=51 %. La dureté shore de chaque premier et deuxième matériau latéral M1 , M2 est égal à 53 et la dureté shore du matériau central MO est égal 67. La dureté shore est par exemple mesurée selon la norme JIS K6253 à 23°C en utilisant un duromètre de type A. Le module dynamique en cisaillement G*’1 , G*’2 de chaque premier et deuxième matériau latéral M1 , M2 mesuré non pas à 10% de deformation and at imposed temperature of 23°C but at 60°C and at imposed stress (0.7 MPa) is equal to 0.95 MPa and the dynamic shear modulus G*'O of the central material MO measured not at 10% deformation and at imposed temperature of 23°C but at 60°C and at imposed stress (0.7 MPa) is equal to 1.14 MPa.

[0125] The complex shear modulus G*' at imposed stress is determined using a Metravib VA4000 or DMA+450 type viscoanalyzer using specimens comprising a cured composition extracted from the tire. The response of the specimens subjected to alternating simple sinusoidal shear stress is recorded at a frequency of 10 Hz under a force equal to 55 N. A temperature sweep is carried out between -80°C and 80°C at a speed of 1.5°C / min, having previously accommodated the specimens to 100% peak-peak strain at a temperature less than or equal to 40°C, for example 23°C. The test piece is of cylindrical section as described in ASTM D 5992-96 (version reapproved in 2011, originally approved in 1996) in Figure X2.1 (circular embodiment) and has a diameter of 10 mm [0 to + 0.04 mm] and a thickness of 2 mm [1.83-2.33].It should be noted that the force of 55 N is equivalent, in the case of a specimen with a diameter of 10.00 mm, to a stress of an amplitude equal to 0.7 MPa peak-peak. The complex shear modulus G*' is measured at 60°C.

[0126] Each first and second lateral material M1, M2 respectively has a maximum dynamic loss tanDMAX23-1, tanDMAX23-2, such that tanDMAX23-1 < 0.20 and tanDMAX23-2 < 0.20, preferably tanDMAX23-1 < 0.15 and tanDMAX23-2 < 0.15 and the central material MO has a maximum dynamic loss tanDMAX23-0 such that 0.40 < tanDMAX23-0 < 0.50. Here, tanDMAX23-1=tanDMAX23-2=0.14 and tanDMAX23-0=0.46.

[0127] The glass transition temperature Tg of each first and second lateral material M1, M2 is equal to -24°C and the glass transition temperature Tg of the central material MO is equal to -10°C. Each glass transition temperature Tg is determined using a viscoanalyzer of the Metravib VA4000 or DMA+450 type using test pieces comprising a cured composition extracted from the tire. The response of the test pieces subjected to a sinusoidal stress in alternating simple shear, at a frequency of 10 Hz under a force equal to 55 N, is recorded. A temperature scan is carried out between -80°C and 80°C at a speed of 1.5°C / min. The test piece is of cylindrical section as described in ASTM D 5992-96 (version reapproved in 2011, originally approved in 1996) in Figure X2.1 (circular embodiment) and has a diameter of 10 mm [0 to + 0.04 mm] and a thickness of 2 mm [1.83-2.33].Note that the force of 55 N is equivalent, in the case of a. test piece with a diameter equal to 10.00 mm at a stress of amplitude equal to 0.7 MPa peak-peak. The glass transition temperature Tg is taken equal to the temperature for which the value of the tangent of the phase angle tanD is maximum. The tangent tanD of the phase angle D between the force exerted on the sample and its displacement reflects a dynamic loss and is equal to the ratio G” / G'.

[0128] Table 1 below lists the compositions from which the first and second lateral materials M1, M2 and central MO were manufactured in a conventional manner known to those skilled in the art. The values ​​are given in pce.

[0129] [Table 1]

[0130] (1) - Styrene-Butadiene Elastomer described as Polymer B on page 34 of WO2018115722; (2) - (2) - Styrene-Butadiene Elastomer described as Polymer E on page 34 of WO2018115722; (3) - Styrene-Butadiene Elastomer described as Polymer C on page 34 of WO2018115722; (4) - Styrene-Butadiene Elastomer described as Control Polymer A on page 39 of WO2022162292; (5) - Carbon Black Grade 234 according to ASTM D-1765; (6) - Silica 160MP from Solvay; (7) - "Si75" from Evonik; (8) - "Si69" from Evonik; (9) - N-ter-butyl-2-benzothiazyl sulfenamide (marketed by the company Flexsys;(10) - The other additives are conventionally known to those skilled in the art and here include in particular a protective wax, N-1,3-dimethylbutyl-N-phenylparaphenylenediamine, N-cyclohexyl-benzothiazyl sulphenamide, diphenylguanidine, sulphur, stearic acid, zinc oxide, oleic sunflower oil and an AMO70 processing agent.;

[0131] The radially inner layer 54 comprises an MS material having a dynamic shear modulus G*S measured at 23°C at 10% strain and at a frequency of 10 Hz according to ASTM D 5992 - 96 such that G*S=1.67 MPa and a maximum dynamic loss tanDMAX23-S=0.13. The MS material is manufactured from a composition conventionally comprising at least one diene elastomer and here comprising a styrene-butadiene elastomer, a butadiene elastomer and a natural rubber, at least one filler and here comprising a carbon black, for example a carbon black N234, and a silica, a coupling agent for example a silane “Si69” or “Si75” from the company Evonik, a resin, for example a hydrogenated DCPD resin marketed under the reference PR-383 by the company Exxon or a C5-C9 hydrocarbon cut marketed under the reference ECR-373 by the company Exxon, as well as various additives such as those described previously for the materials MO, M1 and M2.

[0132] Still with reference to Figure 1, the crown 12 comprises a crown reinforcement 60 extending in the crown 12 in the circumferential direction X. The tire 10 also comprises a sealing layer 62 to an inflation gas being intended to delimit an internal cavity closed with a mounting support of the tire 10 once the tire 10 is mounted on the mounting support, for example a rim. The crown reinforcement 60 comprises a working reinforcement 64 and a hooping reinforcement 66.

[0133] The working reinforcement 64 comprises two working layers 68, 70. The radially outer working layer 70 is arranged radially outside the radially inner working layer 68.

[0134] The hoop reinforcement 66 comprises at least one hoop layer and here comprises a hoop layer 72.

[0135] Among the layers 68, 70, 72 of the crown reinforcement, the axially narrowest layer is the radially outer working layer 70 which has first and second ends 701, 702.

[0136] The crown reinforcement 60 is arranged radially inside the tread 14. The hoop reinforcement 66, here the hoop layer 72, is arranged radially outside the working reinforcement 64 and radially inside the tread 14. The hoop reinforcement 66 is therefore radially interposed between the working reinforcement 64 and the tread 14. The hoop layer 72 is therefore the radially outermost layer of the crown reinforcement 60.

[0137] The tire 10 comprises two sidewalls 74 extending the crown 12 radially inwards. The tire 10 further comprises two beads 76 radially inwards to the sidewalls 74. Each sidewall 74 connects each bead 76 to the crown 12.

[0138] The tire 10 comprises a carcass reinforcement 78 anchored in each bead 76, in this case is wound around two bead wires 80. The carcass reinforcement 78 extends radially in each sidewall 74 and axially in the crown 12 radially inside the crown reinforcement 60. The crown reinforcement 60 is arranged radially between the tread 14 and the carcass reinforcement 78. The carcass reinforcement 78 comprises at least one carcass layer and here comprises a single carcass layer 82.

[0139] Each working layer 68, 70, hooping layer 72 and carcass layer 82 comprises a polymeric matrix, here an elastomeric matrix in which one or more reinforcing elements of the corresponding layer are embedded. Thus, each working layer 68, 70 respectively comprises metallic working wire reinforcement elements, the hooping layer 72 comprises textile hooping wire reinforcement elements and the carcass layer 82 comprises textile carcass wire reinforcement elements. The angles of the wire reinforcement elements as well as the materials of the wire reinforcement elements are for example described in WO2021250331.

[0140] In particular, the metal wire reinforcement elements of each working layer 68, 70 extend substantially parallel to each other in a direction forming an angle strictly greater than 10°, preferably ranging from 15° to 50° and more preferably ranging from 20° to 35° with the circumferential direction X. The main direction in which each wire reinforcement element of the working layer 68 extends and the main direction in which each wire reinforcement element of the working layer 70 extends form, with the circumferential direction of the tire, angles of opposite orientations and of absolute values ​​here equal.

[0141] The hooping wire reinforcement element is wound circumferentially helically so as to extend axially between the axial edges of the hooping reinforcement 66 in a main direction forming, with the circumferential direction of the tire, an angle, in absolute value, less than or equal to 10°, preferably less than or equal to 7° and more preferably less than or equal to 5°.

[0142] The axial distance D1, D2 between each first and second radially outer interface point 11, I2 and each edge 19, 21 of the axially outer main circumferential cutout 22, 24 adjacent to each first and second interface 11, I2 is greater than or equal to 5 mm, preferably 7 mm. Here, D1 = 7 mm, D2 = 17 mm.

[0143] Each axial distance E1, E2 between each first and second radially outer interface point 11, I2 and each axial end 701, 702 of the axially narrowest layer 70 located on the same side of the median plane M as each first and second interface 56, 58 is such that E1 > 13 mm and E2 > 13 mm, preferably E1 > 15 mm and E2 > 15 mm. Furthermore, each distance E1, E2 is such that E1 > 0.05 x L and E2 > 0.5 x L, preferably E1 > 0.07 x L and E2 > 0.07 x L and even more preferably E1 > 0.09 x L and E2 > 0.09 and E1 < 0.15 x L and E2 < 0.15 x L, preferably E1 < 0.13 x L and E2 < 0.13 x L and even more preferably E1 < 0.11 x L and E2 < 0.11 x L with L being the axial width of the axially narrowest layer 70. Here L=212 mm, E1=E2=20 mm.

[0144] With reference to Figure 2, the tangent T at each first and second interface 56, 58 at each first and second radially outer interface point 11, 12 forms an angle A greater than or equal to 30°, preferably 45° with the radial direction Z of the tire 10.

[0145] Tires according to second, third, fourth and fifth embodiments will now be described with reference to Figures 4 to 12. Elements similar to those described with reference to the first embodiment are designated by identical references.

[0146] Unlike the tire according to the first embodiment, the tire according to the second embodiment of Figure 6 does not comprise a second axially lateral portion of the tread layer but an axially central portion POc of the tread layer 52 and a single axially lateral portion Pic arranged axially outside the axially central portion POc. The axially central portion POc of the tread layer 52 extends axially from the first axial edge 18 of the tread surface 16 arranged on the opposite side relative to the median plane M of the axially lateral portion Pic to a contact interface 57 between the axially central portion POc and the axially lateral portion Pic.The axially lateral portion Pic of the wearing course 52 extends axially from the second axial edge 20 of the running surface 16 arranged on the same side of the median plane M as the axially lateral portion Pic to the interface 57. The axially lateral portion Pic comprises the first material M1 and the axially central portion POc comprises the material MO described previously.

[0147] Furthermore, the axially central portion POc is in contact with the axially lateral portion Pic via the interface 57 which is arranged in the axially central portion POb of the tread 14, and here in the central rib 36 which is the rib adjacent to the axially outer main circumferential cutout 24 and arranged axially inside the axially outer main circumferential cutout 24. The interface 57 extends radially from a radially outer interface point 111 of the tread surface 16 to a radially inner interface point 113.

[0148] The axially lateral portion Pic is arranged on the same side of the median plane M as the outer side EXT of the tire 10 and the axially central portion POc is arranged on the same side of the median plane M as the inner side INT of the tire 10. The axially central portion POc has an axial width strictly greater than the axial width of the axially lateral portion Pic.

[0149] The axial distance E1 between the radially outer interface point 111 and the axial end 702 is such that E1 > 0.05 x L, preferably E1 > 0.07 x L and even more preferably E1 > 0.09 x L. We also have E1 > 13 mm, preferably E1 > 15 mm, more preferably E1 > 25 mm and even more preferably E1 > 35 mm. and here E1 = 62 mm and L = 212 mm. Each axial distance D11, D12 between the radially outer interface point 111 and each edge 23, 25 of each main circumferential cutout 24, 28 adjacent to the interface 57 is greater than or equal to 5 mm, preferably 7 mm. Here D11 = D12 = 15 mm. The angle A is identical to that of the first embodiment.

[0150] Unlike the tire according to the first embodiment, the tire according to the third embodiment of Figures 7 and 8 comprises a radially inner layer 54 formed in each first and second lateral material M1, M2 (the first and second lateral materials are identical). The radially inner layer 54 is integral with each first and second lateral material M1, M2 of the tread layer 52. The radially inner layer 54 is arranged radially inside the axially central portion POc of the tread layer 52. The angle A is identical to that of the first embodiment.

[0151] Unlike the tire according to the first embodiment, the tire 10 according to the fourth embodiment of FIGS. 9 to 11 comprises a tread 14 in which each transverse cutout 38, 38', 40, 40', 42 extends between its first and second ends in a mean direction forming an angle respectively denoted A38, A38', A40, A40', A42 with the axial direction Y of the tire 10 such that A38=A38'=10° and A40=A40'=A42=40°.

[0152] With reference to Figures 9 to 11, each transverse cutout 38 comprises three portions 381, 382, ​​383 respectively having a depth H81, H82, H83 such that H82=4.7 mm and H81=H83=1.4 mm. Each transverse cutout 38' comprises two portions 38T, 382' respectively having a depth H81'=1.4 mm and H82'=4.7 mm. Each transverse cutout 40 comprises two portions 401, 402 respectively having a depth H01, H02 such that H01=1.4 mm and H02=4.9 mm. Each transverse cutout 40' comprises a portion 402' having a depth H02'=4.9 mm. Each transverse cutout 42 comprises two portions 421, 422 respectively having a depth H21, H22 such that H21=1.4 mm and H22=4.9 mm. Each portion 381, 382, ​​383, 381', 382', 401, 402, 402', 421, 422 has a minimum width less than or equal to 1.5 mm, preferably ranging from 0.2 mm to 1.5 mm and here equal to 0.4 mm.

[0153] Each first and second axially lateral portion P1b, P2b respectively comprises a first and a second lateral rib respectively designated by the reference 44, 46. The tread 14 comprises first and second transverse cutouts 48', 48”, 50', 50” formed at least in part in each first and second axially lateral portion P1b, P2b. The first transverse cutouts 48', 48” are arranged on the inner side INT of the tire 10. The second transverse cutouts 50', 50” are arranged on the outer side EXT of the tire 10.

[0154] Each first transverse cutout 48' extends in a mean direction forming an angle A48' equal to 10° with the axial direction Y and comprises a portion 48T having a maximum depth H481'=4.7 mm. Each first transverse cutout 48' also comprises a portion widened axially outside the portion formed in the first axially lateral portion P1b and having a width equal to 4.0 mm. Each first transverse cutout 48” extends in a mean direction forming an angle A48” equal to 10° with the axial direction Y and comprises two portions 481”, 482” having respectively a maximum depth H481”=4.7 mm and a maximum depth H482”=1.4 mm.

[0155] Each second transverse cutout 50', 50” extends in a mean direction forming an angle A50', A50” equal to 10° with the axial direction Y and comprises a portion 50T, 501” having a depth H50T, H501” equal to 4.7 mm. Each second transverse cutout 50', 50” also comprises a portion 502', 502” having a depth H502', H502” equal to 1.4 mm. Each second transverse cutout 50' also comprises a portion axially widened outside the portion formed in the second axially lateral portion P2b and having a width equal to 3.0 mm.

[0156] Each first and second transverse cutout 48', 48”, 50', 50” has a minimum width less than or equal to 1.5 mm, preferably ranging from 0.2 mm to 1.5 mm and here equal to 0.4 mm.

[0157] All the transverse cutouts described above, whether inclined or not, are provided with chamfers which are not shown.

[0158] Due to the presence of the various transverse cutouts previously described, in particular due to the presence of the second transverse cutouts 50', 50” having widths smaller than those of the second transverse cutouts 50', 50” of the tire according to the first embodiment, the tread 14 has a volumetric notch rate equal to 22% which allows it to generate exterior noise lower than that of the tire according to the first embodiment in return for slightly degraded wet grip.

[0159] In a first variant of materials MO, M1, M2 of the tire according to the fourth embodiment making it possible to promote drift rigidity, the dynamic shear moduli G*C, G*1, G*2 verify 50% < G*1 / G*C < 85% and / or 50% < G*2 / G*C < 85%, preferably 65% ​​< G*1 / G*C < 85% and 65% < G*2 / G*C < 85% and more preferably 70% < G*1 / G*C < 85% and 70% < G*2 / G*C < 85% and even more preferably, 50% < G*1 / G*C < 80% and / or 50% < G*2 / G*C < 80%, preferably 65% ​​< G*1 / G*C < 80% and 65% < G*2 / G*C < 80% and more preferably 70% < G*1 / G*C < 80% and 70% < G*2 / G*C < 80%. In this first variant of the MO, M1 and M2 materials, G*1=G*2=2.56 MPa, G*C=3.40 MPa and G*1 / G*C=G*2 / G*C=75%.

[0160] In this first variant embodiment of the materials MO, M1 and M2, the Shore hardness of each first and second lateral material M1, M2 is equal to 66 and the Shore hardness of the central material MO is equal to 74. The dynamic shear modulus of each first and second lateral material M1, M2 measured not at 23°C but at 60°C and at imposed stress (0.7 MPa) is equal to 1.38 MPa and the dynamic shear modulus of the central material MO measured not at 23°C but at 60°C and at imposed stress (0.7 MPa) is equal to 1.40 MPa.

[0161] In this first variant embodiment of the materials MO, M1 and M2, each first and second lateral material M1, M2 respectively has a maximum dynamic loss tanDMAX23-1, tanDMAX23-2, such that 0.30 < tanDMAX23-1 and 0.30 < tanDMAX23-2 and the central material MO has a maximum dynamic loss tanDMAX23-0 such that 0.50 < tanDMAX23-0 and here tanDMAX23-1=tanDMAX23-2=0.32 and tanDMAX23-0=0.54.

[0162] In this first variant embodiment of the materials MO, M1 and M2, the glass transition temperature Tg of each first and second lateral material M1, M2 is equal to -10°C and the glass transition temperature Tg of the central material MO is equal to -4°C.

[0163] Table 2 below brings together the compositions from which the first and second lateral materials M1, M2 and the central material MO of this first variant embodiment of the materials MO, M1 and M2 described just above were manufactured in a conventional manner known to those skilled in the art. values ​​are given in pce. The constituents are identical to those in Table 1.

[0164] [Table 2]

[0165] Still in this first variant embodiment of the materials MO, M1 and M2, the material MS of the radially inner layer 54 has a dynamic shear modulus G*S measured at 23°C at 10% deformation and at a frequency of 10 Hz according to the standard ASTM D 5992 - 96 such that G*S=1.88 MPa and a maximum dynamic loss tanDMAX23-S=0.12. The material MS is manufactured from a composition as described previously using a carbon black N550 instead of carbon black N234 and the person skilled in the art will know how to modify the proportions in order to obtain the dynamic properties described above.

[0166] In a second variant of materials MO, M1, M2 of the tire according to the fourth embodiment allowing to promote the reduction of rolling resistance, the dynamic shear moduli G*C, G*1, G*2 verify 40% <G*1 / G*C < 70% et / ou 40% < G*2 / G*C < 70%, de préférence 40% <G*1 / G*C < 60% et 40% < G*2 / G*C < 60%. Dans cette deuxième variante de réalisation des matériaux MO, M1 et M2, G*1=G*2=1 ,35 MPa, G*C=2,56 MPa et G*1 / G*C=G*2 / G*C=53 %.

[0167] In this second variant embodiment of the materials MO, M1 and M2, the Shore hardness of each first and second lateral material M1, M2 is equal to 53 and the Shore hardness of the central material MO is equal to 66. The dynamic shear modulus of each first and second lateral material M1, M2 measured not at 23°C but at 60°C and at imposed stress (0.7 MPa) is equal to 0.95 MPa and the dynamic shear modulus of the central material MO measured not at 23°C but at 60°C and at imposed stress (0.7 MPa) is equal to 1.38 MPa.

[0168] In this second variant of the production of materials MO, M1 and M2, each first and second lateral material M1, M2 respectively has a maximum dynamic loss tanDMAX23-1, tanDMAX23-2, such that tanDMAX23-1 < 0.20 and tanDMAX23-2 < 0.20, preferably tanDMAX23-1 < 0.15 and tanDMAX23-2 < 0.15 and the central material MO has a maximum dynamic loss tanDMAX23-0 such that tanDMAX23-0 < 0.40. Here, tanDMAX23-1=tanDMAX23-2=0.14 and tanDMAX23-0=0.32.

[0169] In this second variant embodiment of the materials MO, M1 and M2, the glass transition temperature Tg of each first and second lateral material M1, M2 is equal to -24°C and the glass transition temperature Tg of the central material MO is equal to -10°C.

[0170] Still in this second variant embodiment of the materials MO, M1 and M2, the material MS of the radially inner layer 54 is identical to that of the tire according to the first embodiment.

[0171] Table 3 below brings together the compositions from which the first and second lateral materials M1, M2 and the central material MO of this second variant embodiment of the materials MO, M1 and M2 described just above were manufactured in a conventional manner known to those skilled in the art. The values ​​are given in pce. The constituents are identical to those in Table 1.

[0172] [Table 3]

[0173] Unlike the tire according to the first embodiment, the tire according to the fifth embodiment of Figure 12 is a so-called winter tire. Such a tire does not have ribs like the tires of the previous embodiments. The tire 10 of Figure 12 has first and second interfaces according to the invention and arranged in the first and second sets of blocks 90, 92 extending axially respectively from each first and second axial edge 18, 20 of the rolling surface 16 towards the median plane M as well as in the first and second axial cutouts 94, 96 respectively separating two first and second sets of circumferentially consecutive breads 90, 92.

[0174] COMPARATIVE TESTS

[0175] The tire 10 according to the first embodiment was compared with a control tire TA. Unlike the tire 10, the control tire T is such that E1 < 0.05 x L and E2 < 0.05 x L. In this case, the control tire T is such that each radially outer interface point 11, 12 is directly above each first and second axial end 701, 702 of the axially narrowest layer of the crown reinforcement 60.

[0176] The tires 10 and T were driven each time on the same vehicle on a wet winding racetrack in order to mechanically stress the tread while sparing its wear. Thus, driving was done at the limits of grip in the bends for 10 to 50 km. At the end of this driving, each tire that had been driven was exposed to an atmosphere rich in ozone for 3 weeks in order to simulate aging of each tire. At the end of this exposure, the tires and more particularly the first and second interfaces 56, 58 were examined. The control tire T showed crack initiation on the surface of the tread at at least one interface while the tire 10 showed no crack or crack initiation on the surface of the tread.

[0177] A wear test was also carried out by rolling each tire according to the invention 10 and control T for several thousand km in order to wear down the tread layer. It was observed that the control tire T had a thickness shift in the vicinity of each interface while the tire 10 according to the invention had homogeneous wear in the vicinity of each first and second interface so that no thickness shift between the central portion and each first and second lateral portion was visible.

[0178] Thus, the invention made it possible to eliminate any risk of cracks appearing at the interface and to eradicate the thickness difference.

[0179] The tire 10 according to the first embodiment was also compared with a control tire T'. Unlike the tire 10, the control tire T' is such that each first and second interface is positioned respectively in each first and second axially outer main circumferential cutout 22, 24.

[0180] Tires 10 and T' were rolled and exposed to ozone in a manner similar to the previous test. After this exposure, the tires were examined, particularly the first and second interfaces. The control tire T' showed a crack at each of the first and second interfaces, while tire 10 showed no cracks or crack initiations on the tread surface.

[0181] The invention is not limited to the embodiments described above. Indeed, it will be possible without any difficulty and depending on the desired performance compromise, to combine the treads of the tires according to each first, second, third embodiment with the first or second variant of the materials MO, M1 and M2 of the fourth embodiment described above.

[0182] It may also be provided that the tread comprises noise reduction devices, in particular Helmoltz resonators as described for example in EP0989000, EP2011671, EP2240335, EP2627524.

[0183] It may also be provided that the tire includes a noise reduction device as described in WO2022 / 069822 or as described in EP1219944, EP1253025, EP1184207, EP1110763, EP1876038.

Claims

CLAIMS 1. A tire (10) comprising a crown (12) comprising a tread (14) carrying a tread surface (16) and a crown reinforcement (60) arranged radially inside the tread (14), the crown reinforcement (60) comprising an axially narrowest crown layer (70), the tread (14) comprising a tread layer (52) comprising an axially central portion (POc) of the tread layer (52) and an axially lateral portion (P1 c, P2c; Pic) of the tread layer (52) arranged axially outside the axially central portion (POc) of the tread layer (52), the axially central portion (POc) and the axially lateral portion (P1c, P2c; Pic) of the tread layer (52) respectively comprise a central material (MO) and a lateral material (M1, M2; M1), the central material (MO) being different of the lateral material (M1, M2;M1), the axially central portion (POc) of the tread layer (52) being in contact with the axially lateral portion (P1c, P2c; Pic) of the tread layer (52) via an interface (56, 58; 57) extending radially from a radially outer interface point (11, I2; 111) of the tread surface (16), the tread (14) comprising main circumferential cutouts (22, 24, 26, 28) having a depth greater than or equal to 50% of the tread height and ribs (44, 46, 32, 34, 36), each rib being axially delimited by at least one of the main circumferential cutouts, the interface (56, 58; 57) is arranged in one of the ribs (44, 46; 36), characterized in that the axial distance E1 between the radially outer interface point (11, I2;11 1 ) and the axial end (701 , 702) of the axially narrowest crown layer (70) located on the same side of the median plane (M) as the interface is such that E1 > 0.05 x L with L the axial width of the axially narrowest crown layer (70) and in that the axial distance (D1 , D2 ; D11 , D12) between the radially outer interface point (11 , I2 ; 11 1 ) and each edge (19, 21 ; 23, 25) of the or each main circumferential cutout (22, 24 ; 24, 28) adjacent to the interface (56, 58 ; 57) is greater than or equal to 5 mm.; 2. Tire (10) according to the preceding claim, in which the axial distance (D1, D2; D11, D12) between the radially outer interface point (11, I2; 111) and each edge (19, 21; 23, 25) of the or each main circumferential cutout (22, 24; 24, 28) adjacent to the interface (56, 58; 57) is greater than or equal to 7 mm.

3. A tire (10) according to claim 1 or 2, wherein the tread layer (52) comprises first and second axially lateral portions (P1c, P2c) of the wearing course (52) arranged axially outside and on either side of the axially central portion (POc) of the wearing course (52), each first and second axially lateral portion (P1c, P2c) of the wearing course (POc) respectively comprises a first and second lateral material (M1, M2), the central material (MO) being different from each first and second lateral material (M1, M2), the axially central portion (POc) of the wearing course (52) being in contact with each first and second axially lateral portion (P1c, P2c) of the wearing course (52) respectively via a first and a second interface (56, 58), each first and second interface (56, 58) extending respectively radially from a first and second interface point (11, I2) radially outside the running surface (16), each axial distance E1,E2 between each first and second radially outer interface point (11, I2) and each axial end (701, 702) of the axially narrowest crown layer (70) located on the same side of the median plane (M) as each first and second interface (56, 58) is such that E1 > 0.05 x L and E2 > 0.05 x L, each first and second interface (56, 58) is arranged respectively in a first and second rib (44, 46) and the axial distance (D1, D2) between each first and second radially outer interface point (11, I2) and each edge (19, 21) of the or each main circumferential cutout (22, 24) adjacent to each first and second interface (11, I2) is greater than or equal to 5 mm., 4. Tire (10) according to the preceding claim, wherein the main circumferential cutouts having a depth greater than or equal to 50% of the tread height comprise first and second axially outer main circumferential cutouts (22, 24) arranged axially on either side of the median plane (M) of the tire (10), each first and second axially outer main circumferential cutout (22, 24) being, on the same side of a median plane (M) respectively as each first and second interface (56, 58), the axially outermost main circumferential cutout (22) of the tread (14), each first and second interface (56, 58) is arranged: - in the rib (44, 46) adjacent to each first and second axially outer main circumferential cutout (22, 24) respectively, and - axially outside respectively each first and second axially outer main circumferential cutout (22, 24).

5. Tire (10) according to claim 3 or 4, wherein the first axially lateral portion (P1 c) of the tread layer (52) extends axially: - from a first axial edge (18) of the rolling surface (16) arranged on the same side of the median plane (M) as the first axially lateral portion (P1c), - up to the first interface (56), the second axially lateral portion (P2c) of the wearing course (52) extends axially: - from a second axial edge (20) of the rolling surface (16) arranged on the same side of the median plane (M) as the second axially lateral portion (P2c), - up to the second interface (58).

6. Tire (10) according to any one of claims 3 to 5, in which E1 > 13 mm and / or E2 > 13 mm, preferably E1 > 15 mm and / or E2 > 15 mm.

7. Tire (10) according to any one of claims 3 to 6, wherein the tangent (T) at at least one of the first and second interfaces (56, 58), preferably at each first and second interface (56, 58), at each first and second radially outer interface point (11, 12) forms an angle (A) greater than or equal to 30°, preferably 45° with the radial direction (Z) of the tire (10).

8. A tire (10) according to claim 1 or 2, wherein the main circumferential cutouts (22, 24, 26, 28) having a depth greater than or equal to 50% of the tread height comprise at least one axially outer main circumferential cutout (24), the axially outer main circumferential cutout (24) being, on the same side of a median plane (M) as the interface (57), the axially outermost main circumferential cutout (24) of the tread (14), the interface (57) is arranged: - in the rib (36) adjacent to the axially outer main circumferential cutout (24), - axially inside the axially outer main circumferential cutout (24) or axially outside the axially outer main circumferential cutout (24).

9. Tire (10) according to the preceding claim, in which: the axially central portion (POc) of the tread layer (52) extends axially: - from a first axial edge (18) of the rolling surface (16) arranged on the opposite side relative to the median plane (M) of the axially lateral portion (Pic), - up to the interface (57), and the axially lateral portion (Pic) of the wearing course (52) extends axially: - from a second axial edge (20) of the rolling surface (16) arranged on the same side of the median plane (M) as the axially lateral portion (Pic) of the rolling layer (52), - up to the interface (57).

10. Tire (10) according to claim 8 or 9, in which E1 > 13 mm, preferably E1 > 15 mm.

11. Tire (10) according to any one of claims 8 to 10, wherein the tangent (T) at the interface (57) at the radially outer interface point (111) forms an angle (A) greater than or equal to 30°, preferably 45° with the radial direction (Z) of the tire (10).