A tire comprising a complex tread pattern comprising bridged and inclined cutouts

Abstract

The tire (10) comprises a crown (12) comprising a tread (14) comprising a tread layer comprising an axially central portion and an axially lateral portion. The tread (14) comprises first and second axially lateral portions (P1b, P2b) and an axially central portion (P0b). The axially central portion (P0b) comprises several inclined cutouts (38, 38', 40, 40', 42) extending in a mean direction forming an angle (A38, A38', A40, A40', A42) greater than or equal to 20° with the axial direction (Y) of the tire (10) and comprises at least one reduced-depth portion, having a depth less than or equal to 85% of the tread height continuously along said reduced-depth portion. Figure for abstract: Fig 2

Description

Title of the invention: Tire comprising a complex tread comprising bridged and inclined cutouts

[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 differentiated 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. 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 respectively having a dynamic shear modulus at 23°CG*C, G*1, G*2 such that G*1 <G*C et / ou G*2<G*C. On parle de pneumatique à couche de roulement différenciée par opposition à un pneumatique présentant une couche de roulement uniforme constituée d’un matériau unique.

[0003] It was noted that the tire with a differentiated tread layer presented an unsatisfactory overall performance compromise.

[0004] The aim of the invention is to obtain a tire with a differentiated tread layer having, compared to a tire having a uniform tread layer, an improved overall performance compromise between the external noise generated by the tire, the drift stiffness and the rolling resistance and having, compared to a tire having a differentiated tread layer, a reduction in external noise without deterioration in the rolling resistance performance.

[0005] For this purpose, the subject of the invention is a tire comprising a crown comprising a 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 comprising a central material and a lateral material having respectively a dynamic shear modulus G*C, G*1 such that G*1 <G*C, chaque module dynamique en cisaillement G*C, G*1 étant mesuré à 23°C à 10% de déformation et à une fréquence de 10 Hz selon la norme ASTM D 5992 - 96, la bande de roulement comprend des découpures circonférentielles principales présentant une profondeur supérieure ou égale à 50% de la hauteur de sculpture comprenant des première et deuxième découpures circonférentielles principales axialement extérieures agencées axialement de part et d’autre du plan médian du pneumatique, les première et deuxième découpures circonférentielles principales axialement extérieures étant les découpures circonférentielles principales axialement les plus extérieures de la bande de roulement, la bande de roulement comprenant : - first and second axially lateral portions of the tread arranged axially outside respectively each first and second axially outer main circumferential cutout, and - an axially central portion of the tread extending from the first axially lateral portion of the tread to the second axially lateral portion of the tread, the axially central portion of the tread comprising a plurality of central ribs, each central rib being axially delimited by two adjacent main circumferential cutouts, the axially central portion of the tread layer being at least partly arranged in the axially central portion of the tread, the axially lateral portion of the tread layer being at least partly arranged in one of the first and second axially lateral portions of the tread, the axially central portion of the tread comprises a plurality of transverse cutouts formed in at least one of the central ribs and, optionally, at least one secondary circumferential cutout formed in said central rib, said optional secondary circumferential cutout having a depth strictly less than 50% of the tread height, the plurality of transverse cutouts formed in said central rib comprises a plurality of transverse cutouts, called inclined cutouts, each inclined transverse cutout formed in said central rib extending between first and second ends, each first and second end: - belonging to one of the main circumferential cutouts adjacent to said central rib, or - belonging to the or one of the secondary circumferential cut(s) op tional(s) formed in said central rib, or - being formed by a blind point of said central rib, each inclined transverse cutout formed in said central rib extending in a mean direction forming an angle greater than or equal to 20° with the axial direction of the tire, each inclined transverse cutout formed in said central rib comprising at least one portion, called reduced depth, having a depth less than or equal to 85% of the tread height continuously along said reduced depth portion.

[0006] The tire according to the invention makes it possible to obtain an overall compromise of exterior noise / drift stiffness / rolling resistance performance which is improved compared to a tire with a uniform tread layer and which presents a reduction in the exterior noise generated by the tire without deterioration in the rolling resistance performance compared to a tire with a differentiated tread layer.

[0007] The inventors behind the invention understood that the external noise generated by the tire with differentiated tread layer of the state of the art was mainly due to the relatively high intrinsic rigidity of the central material of the axially central portion of the tread layer compared to the relatively low rigidity of the lateral material. Thus, the central material contributes mainly to stiffening the axially central portion of the tread and therefore to increasing the external noise.

[0008] In order to reduce this noise, the transverse cutouts provided in the axially central portion of the tread make it possible to soften the axially central portion of the tread and therefore to compensate for the relatively high intrinsic rigidity of the central material of the tread layer. Furthermore, still with the objective of reducing noise, taking advantage of the presence of these transverse cutouts provided in the axially central portion of the tread, the inventors had the idea of ​​strongly inclining their average direction relative to the circumferential direction in order to spread out over time as much as possible the noise generated by the pumping of the air located between the inclined transverse cutout and the ground during the presence of the inclined transverse cutout in the contact area.Thus, the inclined transverse cutouts contribute to the reduction of external noise on the one hand, by reducing the rigidity of the axially central portion of the tread and, on the other hand, by spreading the pumping noise of the inclined transverse cutouts.

[0009] A counterpart of the high inclination of the inclined transverse cutouts is the reduction of the drift rigidity. Indeed, the transverse cutouts, inclined or not, create a discontinuity in the central part of the tread which softens this central part when transverse forces are applied. This softening is all the more important as the cutout extends in a direction close to a direction perpendicular to the forces. Thus, inclined transverse cutouts make the central part less rigid with respect to the transverse forces applied in drift, hence the reduction of the drift rigidity. The more the transverse cutouts are inclined, i.e. the greater the angle, the more the drift rigidity decreases. In order to compensate for this reduction, instead of abandoning the inclined transverse cutouts, the inventors discovered that by reducing the depth of certain portions of the inclined transverse cutouts, the initial drift rigidity was restored without losing the gain in performance in terms of external noise.

[0010] The characteristic according to which the or each portion of reduced depth has a maximum depth reduced continuously along said portion of reduced depth makes it possible to ensure that the depth is reduced without interruption along the portion of reduced depth. Indeed, if locally the depth were to be too great, the drift rigidity would be degraded.

[0011] The or each portion of reduced depth may have a constant or variable depth. The or each portion of reduced depth extends between two ends beyond which the condition(s) characterizing the portion of reduced depth is or are no longer satisfied, in particular the condition relating to the depth of the portion of reduced depth.

[0012] The invention does not prohibit the use, in addition to the portion(s) of reduced depth, of deep portions in the or each inclined transverse cutout, i.e. having a depth strictly greater than the reduced maximum depth and this continuously along said deep portion.

[0013] According to the invention, the presence of one or more secondary circumferential cutout(s) formed in the central rib is optional. In other words, the rib may have a secondary circumferential rib or not. By secondary, it is meant that the or each secondary circumferential cutout has a depth strictly less than that of the adjacent main circumferential cutouts and here strictly less than or equal to 50% of the tread height. Preferably, the maximum depth of the or each secondary circumferential cutout is less than or equal to 30%, preferably 25% of the tread height. Such secondary circumferential cutouts have no influence on the external noise generated by the tire due to their circumferential orientation.Optionally, the maximum width of the or each secondary circumferential cut is greater than or equal to 1.0 mm and preferably less than or equal to 5.0 mm, more preferably 3.0 mm. Optionally, the maximum depth of the or each circumferential cut is . secondary is greater than or equal to 1.0 mm and preferably less than or equal to 3.0 mm.

[0014] The axially central portion of the tread layer comprises the median plane of the tire.

[0015] 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.

[0016] 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.

[0017] The wearing course is intended to come into contact with the ground when the tire is in new condition 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 which would come into contact with the ground when the tire has a level of wear greater than the regulatory wear threshold is not a wearing course.

[0018] Conventionally, the tread carries a tread surface which 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 terminated. In the case where the tread surface is continuous with the external 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.

[0019] 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 equal to 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 bottom, 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.

[0020] The main direction of a cutout or a portion of a cutout is the direction along which the curve passes equidistant from each of the edges of the cutout or the portion of the cutout 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 or the portion of the cutout to the radial dimension of the rolling surface, and this between each end of the cutout or the portion. The average direction is the shortest curve joining the two ends of the cutout or the portion of the cutout.

[0021] The width of a cutout or a portion of a cutout is, in the case where the cutout or the portion of a cutout does not include a chamfer, on a new tire, the distance between the two main lateral faces measured over the entire depth of the cutout or the portion. The width of a cutout or a portion of a cutout is, in the case where the cutout or the portion of a cutout includes a chamfer, on a new tire, the distance between the two main lateral faces measured over the entire depth of the cutout or the portion radially inside the chamfer. The width is measured substantially perpendicular to the main lateral faces. The minimum width of a cutout or a portion is the smallest width of the cutout or the portion concerned. The maximum width of a cutout or a portion is the largest width of the cutout or the portion concerned.

[0022] The depth of a cut or a 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 a portion is the greatest of the depths of the cut or portion concerned.

[0023] 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.

[0024] A cutout or a portion of a cutout may be transverse or circumferential.

[0025] A transverse cutout or portion is such that the cutout or portion extends in a mean direction forming an angle strictly greater than 30° with the circumferential direction of the tire, i.e. forming an angle less than or equal to 60° with the axial direction of the tire. A transverse cutout or portion may be continuous, i.e. not interrupted by a tread block or another cutout so that the two main lateral faces determining its length are uninterrupted along the transverse cutout or portion. A transverse cutout or 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.

[0026] 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 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 entire turn of the tire.A circumferential cutout 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.

[0027] 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.

[0028] By axial direction is meant the direction substantially parallel to the axis of revolution of the tire, i.e. the axis of rotation of the tire.

[0029] By circumferential direction is meant 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).

[0030] By radial direction is meant 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.

[0031] By median plane of the tire (denoted M), we mean the plane perpendicular to the axis of rotation of the tire which is located at mid-axial distance of the two beads and passes through the axial center of the crown reinforcement.

[0032] 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 in contact with the ground and the radially innermost point of the tire intended to be in contact with a support, for example a rim.

[0033] By meridian plane is meant a plane parallel to and containing the axis of rotation of the tire and perpendicular to the circumferential direction.

[0034] By radially inner, respectively radially outer, is meant closer to the axis of rotation of the tire, respectively further from the axis of rotation of the tire. By axially inner, respectively axially outer, is meant closer to the median plane of the tire, respectively further from the median plane of the tire.

[0035] 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.

[0036] Any interval of values ​​designated by the expression "between a and b" represents the domain of values ​​going from more than a to less than b (i.e., limits a and b excluded) while any interval of values ​​designated by the expression "from a to b" means the domain of values ​​going from a up to b (i.e., including the strict limits a and b).

[0037] Any angle made between two directions is the smallest of the angles made by these two directions with each other.

[0038] The tires are, in preferred embodiments of the invention, intended for passenger vehicles as defined within the meaning of the European Tire and Rim Technical Organization or “ETRTO” standard, 2023. Such a tire has a section in a meridian cutting 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 Organisation or “ETRTO” standard, 2023 such that the H / S ratio, 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 tyre is mounted, is at least equal to 12 inches and at most equal to 30 inches.

[0039] The tires are, in preferred embodiments of the invention, so-called summer tires. By summer, we mean tires which are neither so-called 4-season or all-season tires, nor so-called winter tires.

[0040] Winter tires are notably identified by an M+S marking (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. Thus, a summer tire does not have an M+S marking or a 3PMSF marking.

[0041] In advantageous and optional embodiments, the or each portion with reduced depth has a depth less than or equal to 80%, preferably 75% and more preferably 60% of the sculpture height continuously along said portion with reduced depth.

[0042] Thus, the loss of drift rigidity associated with the presence of inclined transverse cutouts is further reduced.

[0043] In advantageous and optional embodiments, the or each portion with reduced depth has a depth greater than or equal to 30%, preferably 40% of the sculpture height continuously along said portion with reduced depth.

[0044] Thus, the noise generated by the tire is further reduced by softening the axially central portion of the tread and therefore compensating for the relatively high intrinsic rigidity of the central material of the tread layer.

[0045] In advantageous and optional embodiments, the or each inclined transverse cutout extends in a mean direction forming an angle greater than or equal to 25°, preferably 30°, more preferably 35° and even more preferably 40° with the axial direction of the tire.

[0046] This further reduces the external noise generated by the tire.

[0047] In advantageous and optional embodiments, the or each inclined transverse cutout extends in a mean direction forming an angle less than or equal to 60°, preferably 45° with the axial direction of the tire.

[0048] This ensures that the stiffness of the drift is not too impacted by the cutouts. inclined crossbars.

[0049] In advantageous and optional embodiments, the or each portion with reduced depth has a minimum width less than or equal to 1.5 mm, preferably ranging from 0.2 mm to 1.5 mm.

[0050] A reduced minimum width makes it possible to reduce the external noise generated by the tire compared to portions of reduced depth having a greater minimum width.

[0051] In advantageous and optional embodiments, the axially central portion of the tread comprises a total of Nn central ribs, at least 60%, preferably at least 80% and more preferably 100% of the Nn central ribs comprising inclined transverse cutouts comprising at least one portion of reduced depth.

[0052] Thus, the effects of inclined transverse cutouts are distributed over several central ribs. This also avoids excessively differentiating the rigidity of the different central ribs, which could generate irregular wear of the axially central portion of the tread.

[0053] In advantageous and optional embodiments, the or each central rib i comprising in total Nti inclined transverse cutouts and in total Nri inclined transverse cutouts comprising at least one portion with reduced depth, Nri / Nti > 30%, preferably Nri / Nti > 50% and more preferably Nri / Nti > 70%.

[0054] Thus, the invention is applied to a significant number of inclined transverse cutouts of the or each central rib. The proportion of inclined transverse cutouts being inclined cutouts comprising at least one portion of reduced depth will be a function of the overall performance compromise described above sought by the person skilled in the art.

[0055] In advantageous and optional embodiments, the plurality of inclined transverse cutouts provided in said central rib is distributed into one or more groups of identical inclined transverse cutouts within the same group.

[0056] By identical within the same group is meant that the inclined transverse cutouts of the same group have identical geometric characteristics. The determining geometric characteristics are in particular the width along the inclined transverse cutout, the depth along the inclined transverse cutout, the angle of the mean direction of the inclined transverse cutout and the principal direction of the inclined transverse cutout.

[0057] Thus, for example, two inclined transverse cutouts having a different maximum width belong to two different groups. Similarly, two Inclined transverse cuts extending in a mean direction forming different angles with the axial direction belong to different groups. Similarly, two inclined transverse cuts with non-identical principal directions belong to different groups.

[0058] In advantageous and optional embodiments: - in the case where the plurality of inclined transverse cutouts comprises a single group of identical inclined transverse cutouts formed in said central rib, the axial length of the reduced depth portion or the sum of the axial lengths of the reduced depth portions of the identical inclined transverse cutouts of the group is greater than or equal to 40%, preferably 60% and more preferably 75% of the axial length of said central rib, and - in the case where the plurality of inclined transverse cutouts comprises N>2 groups of identical inclined transverse cutouts within each group formed in said central rib, the sum of the axial lengths of the reduced depth portions of the identical inclined transverse cutouts of all the groups is greater than or equal to N x 40%, preferably N x 60% and more preferably N x 75% of the axial length of said central rib.

[0059] The axial length of the or each portion of reduced depth is the distance in the axial direction measured between the two ends of the or each portion of reduced depth. The axial length of the central rib is the arithmetic mean of the lengths of the central rib in the axial direction taken over one circumferential revolution of the tire. In the case where the central rib has a constant axial length, the axial length is equal to this constant axial length.

[0060] In the case where the plurality of inclined transverse cutouts comprises a single group of identical inclined transverse cutouts, an axial length of the reduced depth portion or the sum of the axial lengths of the reduced depth portions of the identical inclined transverse cutouts of the group relatively large compared to the axial length of said central rib makes it possible to ensure that the depth is reduced over a significant axial length to promote the restoration of the initial drift stiffness without losing the external noise gain.For the same reasons, in the case where the plurality of inclined transverse cutouts comprises several groups of identical inclined transverse cutouts within each group, the sum of the axial lengths of the reduced depth portions of the identical inclined transverse cutouts of all the groups represents a relatively large proportion of the axial length of said central rib.

[0061] In an advantageous and optional embodiment, the or each portion to reduced depth of each inclined transverse cutout of the or at least one group comprises at least one so-called shallow portion and / or at least one so-called moderately deep portion, the or each shallow portion having a depth less than or equal to 30%, preferably 25% of the tread height continuously along said shallow portion, and the or each moderately deep portion has a depth less than or equal to 85%, preferably 80%, more preferably 75% and even more preferably 60% of the sculpture height continuously along said moderately deep portion.

[0062] Each shallow portion allows for further restoration of the initial drift stiffness without losing the external noise gain. Each moderately deep portion allows for ensuring the axially central portion of the tread is softened to compensate for the relatively high intrinsic stiffness of the central material of the tread layer.

[0063] In cases where the portion of reduced depth comprises at least one shallow portion and at least one moderately deep portion, the latter make it possible to ensure the presence of inclined transverse cutouts extending over a significant axial length and therefore effective. Thus, preferably, said shallow portion and said moderately deep portion communicate directly with each other, that is to say without any other portion being interposed between the shallow portion and the moderately deep portion.

[0064] In a variant of this embodiment and for the same reasons as those described previously concerning the depth of the portion of reduced depth, the or each moderately deep portion has a depth greater than or equal to 30%, preferably 40% of the sculpture height continuously along said moderately deep portion.

[0065] In a variant of this embodiment and for the same reasons as those described previously concerning the depth of the portion of reduced depth, the axial length of the or each shallow portion is greater than or equal to 15%, preferably 30% of the axial length of said portion of reduced depth and / or the axial length of the or each moderately deep portion is greater than or equal to 30%, preferably 40% of the axial length of said portion of reduced depth.

[0066] In a variant, each inclined transverse cutout of the or at least one group comprises first and second ends belonging to each of the two adjacent main circumferential cutouts.

[0067] Such inclined transverse cutouts extending over a significant and therefore efficient axial length.

[0068] In another variant, each inclined transverse cutout of the or at least one group comprises a first end belonging to one of the two adjacent main circumferential cutouts and a second end formed by a blind point of said central rib.

[0069] Such inclined transverse cutouts having a blind end also make it possible to reduce the external noise generated by the tire by reducing the propagation of acoustic waves between the inclined transverse cutouts and the main circumferential cutouts.

[0070] In yet another variant, each inclined transverse cutout of the or at least one group comprises a first end belonging to one of the two adjacent main circumferential cutouts and a second end belonging to the or one of the optional secondary circumferential cutout(s) provided in said central rib.

[0071] Due to the edges of the secondary circumferential cut, transverse grip is increased when the tire is new and has relatively little wear. Due to its relatively shallow depth, the secondary circumferential cut has no significant effect on the rigidity of the tread.

[0072] In advantageous but optional embodiments, the tread comprises first and second transverse cutouts formed at least in part respectively in each first and second axially lateral portion of the tread and having a minimum width less than or equal to 1.5 mm, preferably ranging from 0.2 mm to 1.5 mm.

[0073] Thus, the external noise generated by the tire is further reduced, and in particular here the contribution of the first and second axially lateral portions of the tread.

[0074] In advantageous and optional embodiments, 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 respectively having a dynamic shear modulus G*1, G*2 such that G*1 <G*C et G*2<G*C, le module dynamique en cisaillement G*2 étant mesuré à 23°C à 10% de déformation et à une fréquence de 10 Hz selon la norme ASTM D 5992 - 96, chaque première et deuxième portion axialement latérale de la couche de roulement étant au moins en partie agencée respectivement dans chaque première et deuxième axially lateral portion of the tread.

[0075] Thus, the overall performance compromise can be shifted in favor of one of the desired performances, for example rolling resistance performance.

[0076] In some variants, the first lateral material is identical to the second lateral material, and in particular G*1=G*2. In other variants, the first and second lateral materials are different, and in particular G*1>G*2 or G*1 <G*2.

[0077] In advantageous and optional embodiments: - 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%, - 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%.

[0078] 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 effect of the invention.

[0079] In advantageous and optional embodiments: - in the case where the tire includes an axially lateral portion of the tread layer, G*1 / G*C > 40%, - 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%.

[0080] By differentiating too much the intrinsic rigidities of the central material and the lateral material or of each first and second lateral material, the external noise generated by the central portion will increase, which will have to be compensated for even more by the inclined cutouts.

[0081] In an embodiment making it possible, for example, to reduce the rolling resistance of the tire: - 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%, - dans le cas où le pneumatique comprend des première et deuxième portions axialement latérales de la couche de roulement, 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%.

[0082] Dans une variante de ce mode de réalisation permettant de maximiser la performance en résistance au roulement : - in the case where the tire comprises an axially lateral portion of the tread layer, the lateral material has a maximum dynamic loss tanDMAX23-l such that tanDMAX23-l < 0.20, preferably tanDMAX23-l < 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 first and second axially lateral portions of the tread layer, each first and second lateral material respectively has a maximum dynamic loss tanDMAX23-l, tanDMAX23-2, such that tanDMAX23-l < 0.20 and / or tanDMAX23-2 < 0.20, preferably tanDMAX23-l <0.15 and / or tanDMAX23-2 < 0.15 and the central material has a maximum dynamic loss tanDMAX23-0 such that tanDMAX23-0 < 0.40, preferably tanDMAX23-0 < 0.35.

[0083] In another embodiment making it possible to increase the drift rigidity of the tire and therefore to improve its behavior: - 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%, - 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%.

[0084] In this embodiment making it possible to increase the drift rigidity, the drift rigidity is favored to the detriment of rolling resistance in a variant in which: - in the case where the tire comprises an axially lateral portion of the tread layer, the lateral material has a maximum dynamic loss tanDMAX23-l such that 0.30 < tanDMAX23-l and the central material has a maximum dynamic loss tanDMAX23-0 such that 0.50 < tanDMAX23-0, - 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-l, tanDMAX23-2, such that 0.30 < tanDMAX23-l and / or 0.30 < tanDMAX23-2 and the central material has a maximum dynamic loss tanDMAX23-0 such that 0.50 < tanDMAX23-0.

[0085] Each dynamic loss tanDMAX23 is yet another dynamic property well known to those skilled in the art and is measured on the same type viscoanalyzer Metravib VA4000 or DMA+450 using specimens comprising a cured compound 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 specific temperature conditions (here 23°C) according to ASTM DI349-99. 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 is of cylindrical cross-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 tangent tanD of the phase angle D between the force exerted on the specimen 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 return deformation cycle is recorded.

[0086] In preferred embodiments, the sculpture height belongs to a range from 5.0 mm to 10.0 mm, preferably from 6.0 mm to 8.0 mm.

[0087] In embodiments in which the main circumferential cutouts are relatively deep, each main circumferential cutout has a maximum depth ranging from 4.0 mm at the tread height, preferably from 5.0 mm at the tread height, and more preferably from 5.5 mm at the tread height.

[0088] In embodiments in which the main circumferential cutouts are relatively deep, each main circumferential cutout has a maximum depth greater than or equal to 75% of the tread height, preferably 90% of the tread height.

[0089] In embodiments in which the main circumferential cutouts are relatively wide main circumferential grooves, each main 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.

[0090] In advantageous and optional embodiments: - in the case where the tire comprises an axially lateral portion of the tread layer, the axially central portion of the tread layer is in contact with the axially lateral portion of the tread layer via an interface arranged in the axially central portion of the tread or in the axially lateral portion of the tread, - in the case where the tire comprises first and second axially lateral portions of the tread layer, the axially central portion of the tread layer is in contact with each first and second axially lateral of the tread layer respectively via a first and a second interface arranged respectively in each first and second axially lateral portion of the tread.

[0091] In the case where the tire comprises an axially lateral portion of the tread layer, the arrangement of the interface in the axially central portion of the tread 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, it is meant 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 performs as expected. Indeed, mounting a tire with an orientation different from that imposed by the manufacturer can lead to suboptimal vehicle behavior. By outer side, we mean the side of the tire that is fully 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. Generally, the tire has a marking indicating the inner side and the outer side.

[0092] Still in the case where the tire comprises an axially lateral portion of the tread layer, if it is desired to functionalize less distinctly the side of the tire carrying the axially lateral portion, the interface is arranged in the axially lateral portion of the tread.

[0093] In the case where the tire comprises first and second axially lateral portions of the tread layer, the overall performance compromise is optimized. Indeed, too high a proportion of lateral material or of the first and second lateral materials leads to a reduction in the drift stiffness. Conversely, too high a proportion of the central material reduces the gain in rolling resistance.

[0094] Optionally: - in the case where the tire comprises an axially lateral portion of the tread layer, the axially central portion of the tread layer extends axially from a first axial edge of the tread surface arranged on the opposite side relative to the median plane of the axially lateral portion to the interface, - in the case where the tire comprises first and second portions axially lateral portions of the wearing course, the axially central portion of the wearing course extends axially from the first interface to the second interface.

[0095] Optionally: - in the case where the tire comprises an axially lateral portion of the tread layer, the axially lateral portion extends axially from a second axial edge of the tread surface arranged on the same side of the median plane as the axially lateral portion of the tread layer to the interface, - in the case where the tire comprises first and second axially lateral portions of the tread layer, the first axially lateral portion of the tread layer extends axially from a first axial edge of the tread surface arranged on the same side of the median plane as the first axially lateral portion of the tread layer to the first interface and the second axially lateral portion of the tread layer extends axially from a second axial edge of the tread surface arranged on the same side of the median plane as the second axially lateral portion of the tread layer to the second interface.

[0096] 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 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 tread layer, and - the axially central portion of the wearing course.

[0097] 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, it is understood 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.

[0098] 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 to come into contact with the ground, in particular due to the relative mastery of industrial processes. Preferably, the radially inner layer is in contact with a crown reinforcement of the tire, for example as described below.

[0099] 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 which is intended to be in contact with the ground when the tire is in the new state.

[0100] 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.

[0101] Thus, compared to the first variants, the number of materials of the tread is reduced. Preferably, the first lateral material is identical to the second lateral material.

[0102] In still other variants, the tread does not comprise a radially inner layer. Thus, the tread layer is directly in contact with the crown reinforcement of the tire, for example as described below.

[0103] Conventionally, the tire comprises a crown, two sidewalls, two beads, each sidewall connecting each bead to the crown. The tire also comprises a carcass reinforcement anchored in each bead and extending radially in each sidewall and axially in the crown radially inward to the crown reinforcement.

[0104] 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 filamentary reinforcement elements, each carcass filamentary 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.

[0105] The invention will be better understood on reading the description which follows, given solely by way of non-limiting example and made with reference to the drawings in which: - [Fig.l] is a view, in a meridian section plane, of a tire according to a first embodiment of the invention, - [Fig.2] is a top view of the tread of the tire of [Fig.l], - [Fig. 3] is a detailed view of the tread of the tire of Figures 1 and 2 illustrating certain transverse cutouts, - [Fig.4] is a detailed view of the tread of the tire of Figures 1 and 2 illustrating other transverse cutouts, - figures 5 and 6 are views similar to that of [Fig.l] of tires according to second and third embodiments of the invention, and - figures 7, 8 and 9 are views similar to those of figures 2, 3 and 4 respectively of a tire according to a fourth embodiment of the invention.

[0106] 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.

[0107] Figures 1 to 4 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.

[0108] 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.

[0109] The tread 14 comprises an axially central portion POb of the tread 14 and first and second axially lateral portions Pib, 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.

[0110] 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.

[0111] The first axially lateral portion Pib 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 Pib extends axially from the first axial edge 18 of the rolling 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 rolling 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 Pib of the tread 14 to the second axially lateral portion P2b of the tread 14.

[0112] 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 Hr=Hs=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.

[0113] With reference to figures 1 and 2, the axially central portion POb comprises a plurality of central ribs, here Nn=3 central ribs respectively designated by the references 32, 34, 36. Each central rib 32, 34, 36 is delimited axially by two adjacent main circumferential cutouts 22 to 28. The axially central portion POb comprises a plurality of transverse cutouts 38, 38', 40, 40', 42 formed in the central ribs 32, 34, 36.

[0114] The transverse cutouts 38, 38' formed in the central rib 32 are divided into two groups comprising on the one hand the group of transverse cutouts versales 38 which are all identical to each other within the first group and on the other hand the group of transverse cutouts 38' which are all identical to each other within the second group and different from transverse cutouts 38 of the first group. The transverse cutouts 40, 40' formed in the central rib 34 are divided into two groups comprising on the one hand the group of transverse cutouts 40 which are all identical to each other within the first group and on the other hand the group of transverse cutouts 40' which are all identical to each other within the second group and different from transverse cutouts 40 of the first group. The transverse cutouts 42 are all identical to each other and belong to the single group of transverse cutouts formed in the central rib 36.

[0115] Each transverse cutout 38, 38', 40, 40', 42 extends between first and second ends. Each first and second end of each transverse cutout 38 belongs respectively to each main circumferential cutout 22, 26 adjacent to the central rib 32. Each first and second end of each transverse cutout 38' belongs respectively to the main circumferential cutout 22 adjacent to the central rib 32 and is formed by a blind point of the central rib 32. Each first and second end of each transverse cutout 40 belongs respectively to each main circumferential cutout 26, 28 adjacent to the central rib 34. Each first and second end of each transverse cutout 40' belongs respectively to the main circumferential cutout 28 adjacent to the central rib 34 and is formed by a blind point of the central rib 34.Each first and second end of each transverse cutout 42 belongs respectively to each main circumferential cutout 28, 24 adjacent to the central rib 36.

[0116] Each transverse cutout 38, 38' extends between its first and second ends in a mean direction forming an angle respectively denoted A3 8, A3 8' equal to 10° with the axial direction Y of the tire 10. Thus, each transverse cutout 38, 38' is not inclined.

[0117] Each transverse cutout 40, 40', 42 extends between its first and second ends in a mean direction forming an angle respectively denoted A3 8, A38', A40, A40', A42 greater than or equal to 20°, preferably 25°, more preferably 30°, even more preferably 35° and very preferably 40° and less than or equal to 60°, preferably 45° with the axial direction Y of the tire 10. Here, A40=A40'= A42=40°. Thus, each transverse cutout 40, 40', 42 is said to be inclined.

[0118] With reference to Figures 2 and 3, each transverse cutout 38 of the first group comprises a portion 380 called reduced depth having a depth less than or equal to 85%, preferably 80% and more preferably 75% of the tread height Hs continuously along the reduced depth portion 380. Each reduced depth portion 380 comprises two portions 381, 383 called shallow and one portion 382 called moderately deep communicating directly with each shallow portion 381, 383. Each shallow portion 381, 383 has a depth H81, H83 less than or equal to 30%, preferably 25% of the tread height Hs continuously along each shallow portion 381, 383. Each moderately deep portion 382 has a depth H82 less than or equal to 85%, preferably 80% and more preferably 75% and greater than or equal to 30%, preferably 40% of the tread height Hs continuously along the moderately deep portion 382. Here, H81=H83=1.4 mm and H82=4.7 mm.The axial length L81, L83 of each shallow portion 381, 383 is greater than or equal to 15% of the axial length L80 of the reduced depth portion 380 and here equal to 20% of the axial length L80 of the reduced depth portion 380. The axial length L82 of the moderately deep portion 382 is greater than or equal to 30%, preferably 40% of the axial length L80 and here equal to 60% of the axial length L80.

[0119] With reference to Figures 2 and 4, each transverse cutout 38' of the second group comprises a portion 380' called reduced depth having a depth less than or equal to 85%, preferably 80% and more preferably 75% of the tread height Hs continuously along the reduced depth portion 380'. Each reduced depth portion 380' comprises a portion 381' called shallow and a portion 382' called moderately deep communicating directly with the shallow portion 381'. Each shallow portion 381' has a depth H81' less than or equal to 30%, preferably 25% of the tread height Hs continuously along each shallow portion 381'.Each moderately deep portion 382' has a depth H82' less than or equal to 85%, preferably 80% and more preferably 75% and greater than or equal to 30%, preferably 40% of the tread height Hs continuously along the moderately deep portion 382'. Here, H81'=1.4 mm and H82'=4.7 mm. The axial length L81' of each shallow portion 381' is greater than or equal to 15% of the axial length L80' of the reduced depth portion 380' and here equal to 25% of the axial length L80'. The axial length L82' of the moderately deep portion 382' is greater than or equal to 30%, preferably 40% of the axial length L80' and here equal to 75% of the axial length L80'.

[0120] With reference to figures 2 and 3, each inclined transverse cutout 40 of the first group comprises a portion 400 said to be of reduced depth having a depth less than or equal to 85%, preferably 80% of the tread height Hs continuously along the reduced depth portion 400. Each reduced depth portion 400 comprises a portion 401 called shallow and a portion 402 called moderately deep communicating directly with the shallow portion 401. Each shallow portion 401 has a depth H01 less than or equal to 30%, preferably 25% of the tread height Hs continuously along each shallow portion 401. Each moderately deep portion 402 has a depth H02 less than or equal to 85%, preferably 80% and more preferably 75% and greater than or equal to 30%, preferably 40% of the tread height Hs continuously along the moderately deep portion 402. Here, H01=1.4 mm and H02=4.9 mm.The axial length LOI of each shallow portion 401 is greater than or equal to 15%, preferably 30% of the axial length L00 of the reduced depth portion 400 and here equal to 50% of the axial length L00. The axial length L02 of the moderately deep portion 402 is greater than or equal to 30%, preferably 40% of the axial length L00 and here equal to 50% of the axial length L00.

[0121] With reference to Figures 2 and 4, each inclined transverse cutout 40' of the second group comprises a portion 400' called reduced depth having a depth less than or equal to 85%, preferably 80% and more preferably 75% and greater than or equal to 30%, preferably 40% of the tread height Hs continuously along the reduced depth portion 400'. Each reduced depth portion 400' comprises a portion 402' called moderately deep. Each moderately deep portion 402' has a depth H02' less than or equal to 85%, preferably 80% and more preferably 75% and greater than or equal to 30%, preferably 40% of the tread height Hs continuously along the moderately deep portion 402'. Here, H02'=4.9 mm.The axial length L02' of the moderately deep portion 402' is greater than or equal to 30%, preferably 40% of the axial length L00' of the reduced depth portion 400' and here equal to 100% of the axial length L00'.

[0122] The plurality of transverse cutouts formed in the central rib 34 comprising the first and second groups of inclined transverse cutouts 40, 40' identical within each group, the sum of the axial lengths L40, L40' of the reduced depth portions 400, 400' is greater than or equal to 80%, preferably 120% and more preferably 150% of the axial length of the central rib 34 and here equal to 150% of the axial length of the central rib 34.

[0123] With reference to figures 2 to 4, each inclined transverse cutout 42 comprises a portion 420 called reduced depth having a depth less than or equal to 85%, preferably 80% and more preferably 75% of the sculpture height. Hs continuously along the reduced depth portion 420. Each reduced depth portion 420 comprises a portion 421 called shallow and a portion 422 called moderately deep communicating directly with the shallow portion 421. Each shallow portion 421 has a depth H21 less than or equal to 30%, preferably 25% of the tread height Hs continuously along each shallow portion 421. Each moderately deep portion 422 has a depth H22 less than or equal to 85%, preferably 80% and more preferably 75% and greater than or equal to 30%, preferably 40% of the tread height Hs continuously along the moderately deep portion 422. Here, H21=1.4 mm and H22=4.9 mm. The axial length L21 of each shallow portion 421 is greater than or equal to 15%, preferably 30% of the axial length L20 of the reduced depth portion 420 and here equal to 50% of the axial length L20.The axial length L22 of the moderately deep portion 422 is greater than or equal to 30%, preferably 40% of the axial length L20 and here equal to 50% of the axial length L20.

[0124] The plurality of transverse cutouts formed in the central rib 34 comprising a single group of inclined transverse cutouts 42 identical within the group, the axial length L20 of the reduced depth portion 420 is greater than or equal to 40%, preferably 60% and more preferably 75% of the axial length of the central rib 36 and here equal to 100% of the axial length of the central rib 36.

[0125] Each reduced depth portion 380, 380', 400, 400' and 420 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.

[0126] At least 60%, here 67% of the Nn=3 central ribs 32, 34, 36 comprise inclined transverse cutouts 40, 40', 42 comprising the corresponding reduced depth portions 400, 400' and 420.

[0127] Each central rib 34, 36 comprising in total Nt34, Nt36 inclined transverse cutouts and in total Nr34, Nr36 inclined transverse cutouts comprising at least one portion with reduced depth, Nr34 / Nt34 > 30%, Nr36 / Nt36 > 30%, preferably Nr34 / Nt34 > 50%, Nr36 / Nt36 > 50%, and more preferably Nr34 / Nt34 > 70%, Nr36 / Nt36 > 70% and here Nr34 / Nt34=Nr36 / Nt36=100%.

[0128] Each first and second axially lateral portion Pib, 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 Pib, 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.

[0129] 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 481' 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 Pib and having a width equal to 4.0 mm.

[0130] 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 481” having a maximum depth H481”=4.7 mm. Each first transverse cutout 48” also comprises a portion 482” having a maximum depth H482”=1.4 mm.

[0131] 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 501', 501” having a maximum depth H501', H501” equal to 4.7 mm. Each second transverse cutout 50', 50” also comprises a portion 502', 502” having a maximum 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.

[0132] 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.

[0133] All the transverse cutouts described above, whether inclined or not, are provided with chamfers which are not shown.

[0134] 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.

[0135] The tread layer 52 comprises an axially central portion POc of the tread layer 52 and first and second axially lateral portions Pic, 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 Pic, P2c of the tread layer 52 is at least partly arranged respectively in each first and second axially lateral portion Pib, P2b of the tread 14.

[0136] The radially inner layer 54 is arranged radially inside each first and second axially lateral portion Pic, 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.

[0137] The axially central portion POc is in contact with each first and second axially lateral portion Pic, 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 Pib, P2b of the tread 14 and here in each lateral 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.

[0138] 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 Pic 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 Pic of the wearing course 52 to the first interface 56. The 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.

[0139] The axially central portion POc has an axial width strictly greater than the axial width of each first and second axially lateral portion Pic, P2c.

[0140] 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.

[0141] 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 ASTM D 5992-96. Each first and second axially lateral portion Pic, P2c respectively comprises a first and second lateral material Ml, M2 having respectively a dynamic shear modulus G*l, G*2 measured at 23°C at 10% strain and at a frequency of 10 Hz according to ASTM D 5992-96. The central material MO is different from each first and second lateral material Ml, M2. In the embodiment described herein, rolling resistance is prioritized over drift stiffness. The first and second lateral materials M1, M2 are identical here.

[0142] The dynamic shear moduli G*C, G*l, G*2 verify 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="G*2 / G*C=51" < 70% et ou 40% < g*2 < 70%, de préférence <g*1 < 60% < 60%. dans ce mode réalisation, g*1 mpa, mpa %. la dureté shore chaque premier deuxième matériau latéral ml, m2 est égal à 53 la du central mo 66. par exemple mesurée selon norme jis k6253 23°c en utilisant un duromètre type a. le module dynamique cisaillement g*’ 1, g*’2 mesuré non pas 10% déformation température imposée mais 60°c contrainte (0,7 mpa) 0,95 le g*’0 1,38 mpa.

[0143] 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 scan is carried out between -80°C and 80°C at a speed of 1.5°C / min, having previously accommodated the specimens at 100% peak-peak strain at a temperature less than or equal to 40°C, for example 23°C. The specimen 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 test piece with a diameter equal to 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.

[0144] 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, preferably tanDMAX23-0 < 0.35. Here, tanDMAX23-1=tanDMAX23-2=0.14 and tanDMAX23-0=0.32.

[0145] The glass transition temperature Tg of each first and second material lateral Ml, 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 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 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 specimen 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 test piece with a diameter equal to 10.00 mm, to a stress of an 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'.

[0146] Table 1 below lists the compositions from which the first and second lateral materials M1, M2 and central materials MO were manufactured in a conventional manner known to those skilled in the art. The values ​​are given in pce.

[0147] [Tableauxl] Composition M1,M2 MO SBR 1 (1) 0 100 SBR 2 (2) 0 0 SBR 3 (3) 100 0 SBR 4 (4) 0 0 Carbon black (5) 3 3 Silica (6) 60 98 Silane (7) 0 11 Silane (8) 6 Resin (9) 43 37 Other additives (10) 18 23

[0148] (1) - Styrene-Butadiene Elastomer described as Polymer B on page 34 of WO2018115722; (2) - Styrene-Butadiene Elastomer from Arlanxeo having a Mooney viscosity equal to 54 UM according to ASTM D 1646 (1+4 @ 100°C), a vinyl content unit rate equal to 18%, an average styrene rate equal to 27% and a glass transition temperature equal to -48°C; (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, N1,3-dimethylbutyl-N-phenylparaphenylenediamine, N-cy-clohexyl-benzothiazyl sulphenamide, diphenylguanidine, sulphur, stearic acid, zinc oxide, oleic sunflower oil and an AMO70 processing agent. ;

[0149] 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 the ASTM D 5992 - 96 standard 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, Ml and M2.

[0150] Still with reference to [Fig.l], 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.

[0151] 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.

[0152] The hooping reinforcement 66 comprises at least one hooping layer and here comprises a layer of fretting 72.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] Tires according to second, third and fourth embodiments will now be described with reference to Figures 5 to 9. Elements similar to those described with reference to the first embodiment are designated by identical references.

[0158] Unlike the tire according to the first embodiment, the tire according to the second embodiment of [Fig. 5] does not comprise a second axially lateral portion of the tread layer but an axially central portion POc of the tread layer 52 and an 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. 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 Ml and the axially central portion POc comprises the material MO described previously.

[0159] 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.

[0160] 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.

[0161] Unlike the tire according to the first embodiment, the tire according to the third embodiment of [Fig. 6] 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.

[0162] Unlike the tire according to the first embodiment, each central rib 32, 34, 36 of the tire according to the fourth embodiment of FIGS. 7 to 9 comprises secondary circumferential cutouts 38”, 40”, 42” formed respectively in the central ribs 32, 34, 36. Each secondary circumferential cutout 38”, 40”, 42” has a maximum depth strictly less than 50%, preferably 30%, more preferably 25% of the tread height Hs. Here, Hs=6.1 mm and the maximum depth H82, H02, H22 of each secondary circumferential cutout 38”, 40”, 42” is greater than or equal to 1.0 mm and preferably less than or equal to 3.0 mm and here equal to 1.4 mm. The maximum width L82, L02, L22 of each secondary circumferential cutout 38”, 40”, 42” is greater than or equal to 1.0 mm and preferably less than or equal to 5.0 mm, more preferably 3.0 mm and here equal to 1.4 mm.

[0163] Unlike the tire according to the first embodiment, the transverse cutouts 42, 42' formed in the central rib 34 are distributed in two groups comprising on the one hand the group of transverse cutouts 42 which are all identical to each other within the first group and on the other hand the group of transverse cutouts 42' which are all identical to each other within the second group and different from transverse cutouts 42 of the first group.

[0164] The first end of each transverse cutout 38, 38' belongs respectively to each main circumferential cutout 22, 26 adjacent to the central rib 32 and the second end of each transverse cutout 38, 38' belongs to the secondary circumferential cutout 38” formed in the central rib 32. The first end of each transverse cutout 40, 40' belongs respectively to each main circumferential cutout 26, 28 adjacent to the central rib 34 and the second end of each transverse cutout 40, 40' belongs to the secondary circumferential cutout 40” formed in the central rib 34.The first end of each transverse cutout 42, 42' belongs respectively to each main circumferential cutout 28, 24 adjacent to the central rib 36 and the second end of each transverse cutout 42, 42' belongs to the secondary circumferential cutout 42” formed in the central rib 36.

[0165] In this fourth embodiment, A38=A38'=A40=A40'=A42=A42'=40°. Thus, each transverse cutout 38, 38', 40, 40', 42, 42' is said to be inclined.

[0166] With reference to Figures 7 to 9, each transverse cutout 38, 38', 40, 40', 42, 42' comprises a portion of reduced depth 380, 380', 400, 400', 420, 420' respectively comprising a portion 381, 381', 401, 401', 421, 421' called moderately deep. Each reduced depth portion 380, 380', 400, 400', 420, 420' and moderately deep portion 381, 381', 401, 401', 421, 421' has a depth H81, H81', H01, H01', H21, H21' less than or equal to 85%, preferably 80%, more preferably 75% and even more preferably 60% and greater than or equal to 30%, preferably 40% of the tread height Hs continuously along each reduced depth portion 380, 380', 400, 400', 420, 420' and moderately deep portion 381, 381', 401, 401', 421, 421'. Here, H81=H81'=H01=H0r=H21=H2r=2.8mm.

[0167] Each axial length L81, L81', LOI, LOI', L21, L21' of each moderately deep portion 381, 381', 401, 401', 421, 421' is greater than or equal to 30%, preferably 40% of the axial length L80, L80', L00, L00', L20, L20' of each reduced depth portion 380, 380', 400, 400', 420, 420' and here equal to 100% of the axial length L80, L80', L00, L00', L20, L20' of each reduced depth portion 380, 380', 400, 400', 420, 420'.

[0168] The plurality of transverse cutouts provided in the central rib 32 comprising the first and second groups of inclined transverse cutouts 38, 38' identical within each group, the sum of the axial lengths L80, L80' of the reduced depth portions 380, 380' is greater than or equal to 40%, preferably 60% and more preferably 75% of the axial length of the central rib 32 and here equal to 90% of the axial length of the central rib 32. Similarly, the plurality of transverse cutouts made in the central rib 34 comprising the first and second groups of inclined transverse cutouts 40, 40' identical within each group, the sum of the axial lengths L00, L00' of the reduced depth portions 400, 400' is greater than or equal to 40%, preferably 60% and more preferably 75% of the axial length of the central rib 34 and here equal to 90% of the axial length of the central rib 34.The plurality of transverse cutouts formed in the central rib 36 comprising the first and second groups of inclined transverse cutouts 42, 42' identical within each group, the sum of the axial lengths L20, L20' of the reduced depth portions 420, 420' is greater than or equal to 40%, preferably 60% and more preferably 75% of the axial length of the central rib 36 and here equal to 90% of the axial length of the central rib 36.

[0169] Unlike the first embodiment, 100% of the Nn=3 central ribs 32, 34, 36 comprise inclined transverse cutouts 38, 38', 40, 40', 42, 42' comprising the corresponding reduced depth portions 380, 380', 400, 400', 420, 420' and Nr32 / Nt32=Nr34 / Nt34=Nr36 / Nt36=100%.

[0170] The inclined transverse cutouts 38, 38', 40, 40', 42, 42' are arranged, in each central rib 32, 34, 36, as explained in WO2016 / 177974 so as to reduce the noise generated by the tire.

[0171] Each first and second transverse cutout 48', 50' extends in a mean direction forming an angle A48', A50' equal to 10° with the axial direction Y and comprises a portion 481', 501' having a maximum depth H481', H501' equal to 4.5 mm. Each first and second transverse cutout 48', 50' also comprises an axially widened portion outside each portion formed in each first and second axially lateral portion Pib, P2b and having a width equal to 2.0 mm. Each first and second transverse cutout 48', 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.

[0172] A fifth embodiment may also be envisaged in which drift stiffness is favored over rolling resistance by modifying the materials M1, M1, M2 in the first embodiment. In this fifth embodiment of the materials M1, M1, M2, the dynamic shear moduli G*C, G*l, 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 entially 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 fifth embodiment of the materials MO, Ml, M2, G*1=G*2=2.56 MPa, G*C=3.40 MPa and G*1 / G*C=G*2 / G*C=75%.

[0173] In this fifth embodiment of the materials MO, Ml and M2, the Shore hardness of each first and second lateral material Ml, 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 Ml, 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.

[0174] In this fifth embodiment of the materials MO, Ml and M2, each first and second lateral material Ml, M2 respectively has a maximum dynamic loss tanDMAX23-l, tanDMAX23-2, such that 0.30 < tanDMAX23-l 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-l=tanDMAX23-2=0.32 and tanDMAX23-0=0.54.

[0175] In this fifth embodiment of the materials MO, Ml and M2, the glass transition temperature Tg of each first and second lateral material Ml, M2 is equal to -10°C and the glass transition temperature Tg of the central material MO is equal to -4°C.

[0176] Table 2 below lists the compositions from which the first and second lateral materials M1, M2 and the central material MO of the fifth embodiment 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.

[0177] [Tables2] Composition M1,M2 MO SBR 1 (1) 100 35 SBR 2 (2) 0 0 SBR 3 (3) 0 0 SBR 4 (4) 0 65 Carbon black (5) 3 5 Silica (6) 98 134 Silane (7) 0 0 Silane (8) 11 12 Resin (9) 37 59 Other additives (10) 23 33

[0178] Still in this fifth 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 proportions of which will be known to those skilled in the art in order to obtain the dynamic properties described above.

[0179] COMPARATIVE TESTS

[0180] The 10-MDR1 tires according to the first embodiment and 10-MDR4 according to the fourth embodiment were compared with several control tires respectively designated by the references T1, T2, T3 for the 10-MDR1 tire and T1', T2', T3' for the 10-MDR4 tire.

[0181] The control tire T1 comprises a uniform tread layer consisting solely of a central material having a dynamic shear modulus equal to 2.94 MPa measured at 23°C at 10% deformation and at a frequency of 10 Hz according to the ASTM D 5992-96 standard and comprising transverse cutouts extending in a mean direction forming an angle equal to 10° with the axial direction. The control tire T1' comprises a uniform tread layer consisting solely of a central material having a dynamic shear modulus equal to 1.90 MPa measured at 23°C at 10% deformation and at a frequency of 10 Hz according to the ASTM D 5992-96 standard and comprising transverse cutouts extending in a mean direction forming an angle equal to 10° with the axial direction. axial.

[0182] The control tire T2 comprises a tread layer identical to that of the tire 10-MDR1 and transverse cutouts extending in a mean direction forming an angle equal to 10° with the axial direction. The control tire T2' comprises a tread layer identical to that of the tire 10-MDR4 and transverse cutouts extending in a mean direction forming an angle equal to 10° with the axial direction.

[0183] The control tire T3 comprises a tread layer identical to that of the 10-MDR1 tire and inclined cutouts each extending in a mean direction forming an angle identical to that of the 10-MDR1 tire. Unlike the latter, the inclined cutouts of the control tire T3 have a depth strictly greater than 85% of the tread height along each inclined cutout. The control tire T3' comprises a tread layer identical to that of the 10-MDR4 tire and inclined cutouts each extending in a mean direction forming an angle identical to that of the 10-MDR4 tire. Unlike the latter, the inclined cutouts of the control tire T3 have a depth strictly greater than 85% of the tread height along each inclined cutout.

[0184] The external noise was measured by driving the vehicle on a track compliant with ISO 10844 regulations and certified by UTAC. A measurement area delimited on the track was equipped with Müller-BBM vibro-acoustic acquisition equipment. The noise generated by each tire was measured under acceleration (conditions similar to those used in regulation R51 UN) and with the engine off (conditions similar to those used in regulation RI 17). The raw noise measured was then corrected for the ground temperature as indicated in regulation RI 17 UN. The two test results under acceleration and engine off were then averaged.

[0185] The drift stiffness test is carried out by rolling the tested tire on a rolling machine and applying a given load equal to 500 daN under a pressure of 2.9 bars. During rolling, the tested tire is subjected to the given load and the tire is rotated by +0.5° around the radial axis perpendicular to the contact surface between the tire and the ground, then by +1° around this axis. Then, the measurement is repeated for angles of -0.5° and -1° around this axis. The force generated by the tire by the rolling support is then determined. The drift stiffness is then deduced, which, for a given load, is expressed in daN / °. The higher the drift stiffness, the more the tire is able to respond to the force imposed on it and the better its road behavior.

[0186] The rolling resistance test was carried out according to ISO 28580:2018. For a tested tire, the result is the rolling resistance coefficient which represents the ratio of the force resisting the vehicle's forward movement by the hysteresis of the tire divided by the load carried.

[0187] The results of the various tests are gathered in Tables 3 and 4 below with the control tires Tl, Tl' as a reference. The letter "R" or "R'" means that the test result constitutes a reference value. The "+" sign indicates an improvement in performance compared to that of the control tire Tl, Tl'. Thus, a "+" sign for the "External noise" performance corresponds to a reduction in the external noise generated by the tire and therefore to an improvement in the external noise performance. A "+" sign for the "Rolling resistance" performance corresponds to a reduction in the rolling resistance and therefore to an improvement in the rolling resistance performance. A "+" sign for the "Drift stiffness" performance corresponds to an increase in the drift stiffness and therefore to an improvement in the behavior performance of the tire.Similarly, the sign “-” indicates a deterioration in performance compared to that of the control tire Tl, Tl' and the sign “=” indicates that performance remains at the same level as that of the control tire Tl, Tl'.

[0188] [Tables3] Performance Tl T2 T3 10-MDR1 External noise R + ++ +++ Drift stiffness R - - Rolling resistance R ++++ ++++ ++++ Overall compromise R ++++ ++++ ++++++

[0189] The tests carried out clearly show an improvement in the overall compromise of external noise / drift stiffness / rolling resistance performance compared to the control tire T1 and by reducing the external noise without deterioration of the rolling resistance compared to the control tire T2. In the 10-MDR1 tire, a reduction in the drift stiffness is nevertheless accepted. Indeed, the stiffness of the tread layer of the control tire T1 being relatively high, the use of a less rigid differentiated tread layer in the control tire T2 generates, in return for a reduction in external noise and rolling resistance, a reduction in the drift stiffness which is even more reduced when adding the inclined cutouts in the control tire T3. The presence of the reduced depth portions in the 10-MDR1 tire according to the invention makes it possible to restore part of the lost stiffness without losing the gains of the exterior noise and rolling resistance performance.

[0190] [Tables 4] Performance Tl' T2' T3' 10-MDR4 External noise R' - + ++ Drift stiffness R' +++ ++ +++ Rolling resistance R' = = = Overall compromise R' ++ +++ +++++

[0191] The tests carried out clearly show an improvement in the overall compromise of exterior noise / drift stiffness / rolling resistance performance compared to the control tire T1 by improving the exterior noise performance and without deteriorating the rolling resistance performance compared to the control tire T2. In the 10-MDR4 tire, it is accepted to maintain the rolling resistance performance without improving it. Indeed, the stiffness of the tread layer of the control tire T1' being relatively low, the use of a stiffer axially central portion in the control tire T2' generates, in return for an improvement in the drift stiffness and a maintenance of the rolling resistance, an increase in the exterior noise. The exterior noise is reduced in the control tire T3' thanks to the addition of the inclined cutouts which nevertheless reduce the drift stiffness without impacting the rolling resistance.The presence of the reduced depth portions in the 10-MDR4 tire further reduces exterior noise and restores the drift stiffness of the T2' control tire without losing the performance gain in rolling resistance.

[0192] The invention is not limited to the embodiments described above.

[0193] 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.

[0194] It may also be provided that the tire comprises a noise reduction device as described in WO2022 / 069822 or as described in EP1219944, EP1253025, EPI 184207, EPI 110763, EP1876038.

Claims

Claims

1. A tire (10) comprising a crown (12) comprising a tread (14) comprising a tread layer (52) comprising an axially central portion (POc) of the tread layer (52) and an axially lateral portion (Pic, 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 (Pic, P2c; Pic) of the tread layer (52) respectively comprise a central material (MO) and a lateral material (Ml, M2;Ml) respectively having a dynamic shear modulus G*C, G*1 such that G*1 <G*C, chaque module dynamique en cisaillement G*C, G*1 étant mesuré à 23°C à 10% de déformation et à une fréquence de 10 Hz selon la norme ASTM D 5992 - 96, la bande de roulement (14) comprend des découpures circonférentielles principales (22, 24, 26, 28) présentant une profondeur supérieure ou égale à 50% de la hauteur de sculpture comprenant des première et deuxième découpures circonférentielles principales axialement extérieures (22, 24) agencées axialement de part et d’autre du plan médian (M) du pneumatique (10), les première et deuxième découpures circonférentielles principales axialement extérieures (22, 24) étant les découpures circonférentielles principales axialement les plus extérieures de la bande de roulement (14), la bande de roulement (14) comprenant :; - first and second axially lateral portions (Pib, P2b) of the tread (14) arranged axially outside respectively each first and second axially outer main circumferential cutout (22, 24), and - an axially central portion (POb) of the tread (14) extending from the first axially lateral portion (Pib) of the tread (14) to the second axially lateral portion (P2b) of the tread (14), the axially central portion (POb) of the tread (14) comprising a plurality of central ribs (32, 34, 36), each central rib being axially delimited by two adjacent main circumferential cutouts (22, 24, 26, 28), the axially central portion (POc) of the tread layer (52) being at least partly arranged in the axially central portion (POb) of the tread (14), the axially lateral portion (Pic, P2c; Pic) of the tread layer (52) being at least partly arranged in one of the first and second axially lateral portions (Pib, P2b) of the tread (14), characterized in that the axially central portion (POb) of the tread (14) comprises a plurality of transverse cutouts (38, 38', 40, 40', 42; 38, 38', 40, 40', 42, 42') formed in at least one of the central ribs (32, 34, 36) and, optionally, at least one secondary circumferential cutout (38”, 40”, 42”) formed in said central rib (32, 34, 36), said optional secondary circumferential cutout having a depth strictly less than 50% of the tread height, the plurality of transverse cutouts formed in said central rib comprises a plurality of transverse cutouts, called inclined cutouts (40, 40', 42; 38, 38', 40, 40', 42; 42'), each inclined transverse cutout provided in said central rib (34, 36; 32, 34, 36) extending between first and second ends, each first and second end: - belonging to one of the main circumferential cutouts (22, 24, 26, 28) adjacent to said central rib, or - belonging to the optional secondary circumferential cut(s) (38”, 40”, 42”) made in said central rib, or - being formed by a blind point of said central rib (34), each inclined transverse cutout (40, 40', 42; 38, 38', 40, 40', 42; 42') formed in said central rib (34, 36; 32, 34, 36) extending in a mean direction forming an angle (A40, A40', A42; A38, A38', A40, A40', A42; A42') greater than or equal to 20° with the axial direction (Y) of the tire (10 ... 36) comprising at least one portion, called reduced depth portion (400, 400', 420; 380, 380', 400, 400', 420, 420'), having a depth (H01, H02, H02', H21, H22; H81, H81', H01, H01', H21, H21') less than or equal to 85% of the sculpture height (Hs) continuously along said reduced depth portion.

2. Tire (10) according to the preceding claim, in which the or each reduced depth portion (400, 400', 420; 380, 380', 400, 400', 420, 420') has a depth less than or equal to 80%, preferably 75%, and more preferably 60% of the tread height (Hs) continuously along said reduced depth portion.

3. A tire (10) according to any preceding claim, wherein the or each reduced depth portion (400, 400', 420; 380, 380', 400, 400', 420, 420') has a depth greater than or equal to 30%, preferably 40% of the tread height (Hs) continuously along said reduced depth portion.

4. A tire (10) according to any one of the preceding claims, wherein the or each inclined transverse cutout (40, 40', 42; 38, 38', 40, 40', 42; 42') extends in a mean direction forming an angle (A40, A40', A42; A38, A38', A40, A40', A42; A42') greater than or equal to 25°, preferably 30°, more preferably 35° and even more preferably 40° with the axial direction (Y) of the tire (10).

5. A tire (10) according to any one of the preceding claims, wherein the or each inclined transverse cutout (40, 40', 42; 38, 38', 40, 40', 42; 42') extends in a mean direction forming an angle (A40, A40', A42; A38, A38', A40, A40', A42; A42') less than or equal to 60°, preferably 45° with the axial direction (Y) of the tire (10).

6. A tire (10) according to any one of the preceding claims, wherein the axially central portion (POb) of the tread (14) comprises a total of Nn central ribs (32, 34, 36), at least 60%, preferably at least 80% and more preferably 100% of the Nn central ribs (34, 36; 32, 34, 36) comprises inclined transverse cutouts comprising at least one portion of reduced depth (400, 400', 420; 380, 380', 400, 400', 420; 420').

7. A tire (10) according to any one of the preceding claims, wherein the or each central rib i (34, 36; 32, 34, 36) comprises in total Nti inclined transverse cutouts (40, 40', 42; 38, 38', 40, 40', 42; 42') and in total Nri inclined transverse cutouts (40, 40', 42; 38, 38', 40, 40', 42; 42') comprising at least one portion with reduced depth, Nri / Nti > 30%, preferably Nri / Nti > 50% and more preferably Nri / Nti > 70%.

8. A tire (10) according to any preceding claim, wherein the plurality of inclined transverse cutouts (40, 40', 42; 38, 38', 40, 40', 42; 42') provided in said central rib (34, 36; 32, 34, 36) is distributed into one or more groups of identical inclined transverse cutouts within a single group.

9. A tire (10) according to the preceding claim, wherein: - in the case where the plurality of inclined transverse cutouts (40, 40', 42; 38, 38', 40, 40', 42; 42') comprises a single group of identical inclined transverse cutouts (42) formed in said central rib (36), the axial length (L20) of the reduced-depth portion (420) or the sum of the axial lengths of the reduced-depth portions of the identical inclined transverse cutouts (42) of the group is greater than or equal to 40%, preferably 60% and more preferably 75% of the axial length of said central rib (36), and - in the case where the plurality of inclined transverse cutouts (40, 40', 42; 38, 38', 40, 40', 42; 42') comprises N>2 groups of identical inclined transverse cutouts (40, 40'; 38, 38', 40, 40', 42, 42') within each group formed in said central rib (34; 32, 34, 36), the sum (L00, L00';L80, L80', L00, L00', L20, L20') of the axial lengths of the reduced depth portions (400, 400'; 380, 380', 400, 400', 420, 420') of the identical inclined transverse cutouts of all the groups is greater than or equal to N x 40%, preferably to N x 60% and more preferably to N x 75% of the axial length of said central rib (34; 32, 34, 36).;

10. A tire (10) according to claim 8 or 9, wherein the or each reduced depth portion (400, 400', 420; 380, 380', 400, 400', 420; 420') of each inclined transverse cutout of the or at least one group comprises at least one so-called shallow portion (401, 421) and / or at least one so-called moderately deep portion (402, 402', 422; 381, 381', 401, 401', 421, 421'), the or each shallow portion having a depth less than or equal to 30%, preferably 25% of the tread height (Hs) continuously along said shallow portion, and / or the or each moderately deep portion having a depth less than or equal to 85%, preferably 80%, more preferably 75% and even more preferably 60% of the sculpture height (Hs) continuously along said moderately deep portion.

11. Tire (10) according to the preceding claim, wherein the or each moderately deep portion (402, 402', 422; 381, 381', 401, 401', 421, 421') has a depth greater than or equal to 30%, preferably 40% of the tread height (Hs) continuously along said moderately deep portion.

12. A tire (10) according to claim 10 or 11, wherein the axial length of the or each shallow portion (401, 421) is greater than or equal to 15%, preferably 30% of the axial length of said reduced depth portion and / or the axial length of the or each moderately deep portion (402, 402', 422; 381, 381', 401, 401', 421, 421') is greater than or equal to 30%, preferably 40% of the axial length of said reduced depth portion.

13. A tire (10) according to any one of claims 8 to 12, wherein each inclined transverse cutout (40, 42) of the or at least one group comprises first and second ends belonging to each of the two adjacent main circumferential cutouts (24, 26, 28).

14. A tire (10) according to any one of claims 8 to 12, wherein each inclined transverse cutout (40') of the or at least one group comprises a first end belonging to one of the two adjacent main circumferential cutouts and a second end formed by a blind point of said central rib (34).

15. A tire (10) according to any one of claims 8 to 12, wherein each inclined transverse cutout (38, 38', 40, 40', 42, 42') of the or at least one group comprises a first end belonging to one of the two adjacent main circumferential cutouts (22, 24, 26, 28) and a second end belonging to the or one of the optional secondary circumferential cutout(s) (38”, 40”, 42”) provided in said central rib (32, 34, 36).

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