A tire comprising a complex tread pattern with bridged and inclined grooves

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 shallow-depth portion, having a depth less than or equal to 85% of the tread depth continuously along said shallow-depth portion. Figure for the abbreviation: Fig 2

Description

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

[0001] The present invention relates to a tire, particularly for passenger vehicles. By tire, we mean a band designed to form a cavity by cooperating with a support element, for example a rim, this cavity being capable of being pressurized to a pressure greater than atmospheric pressure. A tire according to the invention has a substantially toroidal structure of revolution about a principal axis of the tire.

[0002] Prior art tires comprising a tread comprising a differentiated tread layer including 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 comprise respectively a central material and first and second lateral materials having respectively 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 overall unsatisfactory performance compromise.

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

[0005] To this end, the invention relates to 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 : - the first and second axially lateral portions of the tread arranged axially outside each of the first and second main axially external circumferential cutouts, 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 principal circumferential cutouts, the axially central portion of the tread being at least partly arranged within the axially central portion of the tread, the axially lateral portion of the tread being at least partly arranged within 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 depth, the plurality of transverse cutouts formed in said central rib comprises a plurality of transverse cutouts, referred to as inclined cutouts, each inclined transverse cutout formed in said central rib extending between first and second extremities, each first and second extremity: - belonging to one of the main circumferential cuts adjacent to said central rib, or - belonging to the secondary circumferential cut(s) op tional cut(s) made in said central rib, or - being formed by a blind point of said central rib, each inclined transverse cut made in said central rib extending along an average direction forming an angle greater than or equal to 20° with the axial direction of the tire, each inclined transverse cut made in said central rib comprising at least one portion, said to be of reduced depth, having a depth less than or equal to 85% of the tread height continuously along said portion of reduced depth.

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

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

[0008] To reduce this noise, the transverse cutouts in the axially central portion of the tread make this portion more flexible and thus compensate for the relatively high intrinsic rigidity of the central material of the tread layer. Furthermore, still with the aim of reducing noise, and taking advantage of the presence of these transverse cutouts in the axially central portion of the tread, the inventors conceived the idea of ​​significantly inclining their average direction relative to the circumferential direction in order to spread out the noise generated by the pumping of air between the inclined transverse cutout and the ground as much as possible when the inclined transverse cutout is in the contact area.Thus, inclined transverse cutouts contribute to the reduction of external noise, firstly by reducing the rigidity of the axially central portion of the tread and, secondly, by spreading the pumping noise of the inclined transverse cutouts.

[0009] A counterpart to the steep angle of the inclined transverse cutouts is the reduction in drift stiffness. Indeed, the transverse cutouts, inclined or not, create a discontinuity in the central part of the tread which This central section becomes more flexible when transverse forces are applied. This flexibility is greater the closer the cutout is to a direction perpendicular to the forces. Thus, inclined transverse cutouts make the central section less rigid with respect to transverse forces applied during drift, hence the reduction in drift stiffness. The more inclined the transverse cutouts, i.e., the greater the angle, the more the drift stiffness decreases. To compensate for this reduction, instead of abandoning inclined transverse cutouts, the inventors discovered that by reducing the depth of certain portions of the inclined transverse cutouts, the initial drift stiffness could be restored without losing the performance gain in external noise.

[0010] The feature in which the reduced depth portion or portions exhibit a continuously reduced maximum depth along said reduced depth portion ensures that the depth is reduced without interruption along the reduced depth portion. Indeed, if the depth were to become too great locally, the rudder rigidity would be degraded.

[0011] The reduced depth portion or portions may have a constant or variable depth. The reduced depth portion or portions extends between two extremities beyond which the condition or conditions characterizing the reduced depth portion are no longer satisfied, in particular the condition relating to the depth of the reduced depth portion.

[0012] The invention does not prohibit the use, in addition to the portion or portions of reduced depth, of deep portions in the or each inclined transverse cut, that is to say having a depth strictly greater than the maximum reduced depth and this continuously along said deep portion.

[0013] According to the invention, the presence of one or more secondary circumferential grooves in the central rib is optional. In other words, the rib may or may not have a secondary circumferential groove. Secondary means that each secondary circumferential groove has a depth strictly less than that of the adjacent primary circumferential grooves, and here strictly less than or equal to 50% of the tread depth. Preferably, the maximum depth of each secondary circumferential groove is less than or equal to 30%, and preferably 25%, of the tread depth. Such secondary circumferential grooves do not affect the external noise generated by the tire due to their circumferential orientation.Optionally, the maximum width of the secondary circumferential cutout(s) 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 circumferential cutout(s) 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 includes 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 viscoelastic analyzer using specimens comprising a baked composition extracted from tires. The response of the specimen subjected to a sinusoidal alternating simple shear load at a frequency of 10 Hz is recorded under determined temperature conditions (here 23°C) according to ASTM D1349-99. A strain amplitude sweep is performed from 0.1% cc to 100% cc (forward cycle), then from 100% cc to 0.1% cc (reverse cycle), cc meaning peak-to-peak. The test specimen has a 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 complex dynamic shear modulus G* is defined as the square root of the sum of the squares of G' and G'', where G' represents the elastic modulus and G'' represents the viscous modulus. The complex shear modulus G* is measured at 10% cc of strain on the return cycle.

[0017] The tread layer is intended to come into contact with the ground when the tire is new and at least until a predetermined wear threshold is reached, for example, a regulatory wear threshold. Such a regulatory wear threshold is indicated, in particular, by the presence of wear indicators in the tread. A layer that would come into contact with the ground when the tire has a level of wear exceeding the regulatory wear threshold is not a tread layer.

[0018] Conventionally, the tread has a tread surface that is axially delimited by first and second axial edges coinciding 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 as defined in 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 a clear boundary between the tread surface and the rest of the tire, the first and second axial edges are de simply finished. In the case where the tread surface is continuous with the external surfaces of the sidewalls of the tire, 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 base, the two main lateral faces being separated from each other by a non-zero distance, called the width of the cutout or portion of the cutout.

[0020] The principal direction of a cutout or portion of a cutout is the direction along which the curve equidistant from each edge of the cutout or portion of the cutout to the radial dimension of the running surface passes. The curvilinear length is the length measured along this curve equidistant from each edge of the cutout or portion of the cutout to the radial dimension of the running surface, between each end of the cutout or portion. The mean direction is the shortest curve joining the two ends of the cutout or portion of the cutout.

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

[0022] The depth of a cut or portion of a cut on a new tire is the radial distance between the bottom of the cut or portion and its projection onto the ground when the tire is rolling. The maximum depth of a cut or portion is the greatest of the depths of the cut or portion in question.

[0023] The maximum value of the depths of the cutouts is called the carving height. Preferably, the maximum value of the depths of the main circumferential cutouts is called the carving height.

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

[0025] A cut or cross-section is such that the cut or cross-section extends along an average 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 cut or cross-section may be continuous, i.e., not interrupted by a tread block or another cut, so that the two principal lateral faces determining its length are uninterrupted along the cross-section or cross-section. A cut or cross-section may also be discontinuous, i.e., interrupted by one or more tread blocks and / or one or more cuts, so that the two principal lateral faces determining its length are interrupted by one or more tread blocks and / or one or more cuts.

[0026] A cut or circumferential portion is such that the cut or portion extends along an average 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 cut, the two ends coincide and are joined by a curve making a complete turn of the tire. A cut or circumferential portion may be continuous, i.e., not interrupted by a tread block or another cut, so that the two principal lateral faces determining its length are uninterrupted over the entire circumference of the tire.A circumferential cut can also be discontinuous, that is, interrupted by one or more tread blocks and / or one or more cuts so that the two main lateral faces determining its length are interrupted by one or more tread blocks and / or one or more cuts over the whole of one revolution of the tire.

[0027] The tire according to the invention has a substantially toroidal shape around an axis of revolution substantially coinciding 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, we mean the direction substantially parallel to the axis of revolution of the tire, that is to say the axis of rotation of the tire.

[0029] By circumferential direction, we mean the direction which is substantially perpendicular to both the axial direction and to 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, we mean 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 ribs and passes through the axial midpoint of the apex reinforcement.

[0032] By circumferential equatorial plane of the tire, in a meridional cutting plane, is meant 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 meridional cutting 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 outermost radial point of the tread intended to be in contact with the ground and the innermost radial point of the tire intended to be in contact with a support, for example a rim.

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

[0034] By radially inside, and radially outside respectively, we mean closer to the axis of rotation of the tire, and further from the axis of rotation of the tire respectively. By axially inside, and axially outside respectively, we mean closer to the median plane of the tire, and further from the median plane of the tire respectively.

[0035] By bead, we mean the portion of the tire designed to allow the tire to be attached to a mounting support, for example a wheel including a rim. Thus, each bead is specifically designed 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. excluding bounds a and b) while any interval of values ​​designated by the expression "from a to b" means the domain of values ​​going from a to b (i.e. including the strict bounds 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] In preferred embodiments of the invention, the tires are intended for passenger vehicles as defined in the European Tyre and Rim Technical Organisation or "ETRTO" standard, 2023. Such a tire has a cross-section in a meridional plane characterized by a The tire must have a section height (H) and a nominal section width (or sidewall size, S) as defined by the European Tyre and Rim Technical Organisation (ETRTO) standard, 2023, such that the H / S ratio, expressed as a percentage, is at most 90 and at least 20, and the nominal section width (S) is at least 115 mm and at most 385 mm. Furthermore, the hook diameter (D), defining the diameter of the tire's mounting rim, is at least 12 inches and at most 30 inches.

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

[0040] Winter tires are 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"). All-season tires, due to their performance on snow, also display the M+S and / or 3PMSF markings. Thus, a summer tire does not bear an M+S or 3PMSF marking.

[0041] In advantageous and optional embodiments, the portion or portions with reduced depth have 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 lateral rigidity associated with the presence of inclined transverse cutouts is further reduced.

[0043] In advantageous and optional embodiments, the portion or portions with reduced depth have 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 cut extends along an average 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] Thus, the external noise generated by the tire is reduced even further.

[0047] In advantageous and optional embodiments, the inclined transverse cut or cut extends along an average direction forming an angle less than or equal to 60°, preferably 45° with the axial direction of the tire.

[0048] Thus, we ensure that the rigidity of the fin is not too affected by the cutouts inclined transverses.

[0049] In advantageous and optional embodiments, the portion or portions with reduced depth have 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 larger 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 includes inclined transverse cutouts comprising at least one portion with reduced depth.

[0052] Thus, the effects of inclined transverse cuts are distributed over several central ribs. This also prevents excessive differentiation in the rigidity of the various central ribs, which could generate uneven wear on 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 central rib(s). The proportion of inclined transverse cutouts comprising at least one portion with reduced depth will depend on the overall performance compromise described above sought by those skilled in the art.

[0055] In advantageous and optional embodiments, the plurality of inclined transverse cutouts formed 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, it is understood that the inclined cross-sections of the same group have identical geometric characteristics. The determining geometric characteristics are in particular the width along the inclined cross-section, the depth along the inclined cross-section, the angle of the average direction of the inclined cross-section, and the principal direction of the inclined cross-section.

[0057] Thus, for example, two inclined transverse cutouts having a different maximum width belong to two different groups. Similarly, two Inclined cross-sections extending along a mean direction and forming different angles with the axial direction belong to different groups. Similarly, two inclined cross-sections 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 shallow portion or the sum of the axial lengths of the shallow 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 portions with reduced depth 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.

[0059] The axial length of the reduced depth portion(s) is the distance along the axial direction measured between the two ends of the reduced depth portion(s). The axial length of the central rib is the arithmetic mean of the lengths of the central rib along the axial direction taken over one circumferential revolution of the tire. If 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 portion with reduced depth or the sum of the axial lengths of the portions with reduced depth 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 gain in external noise.For the same reasons, in the case where the plurality of inclined transverse cuts includes several groups of identical inclined transverse cuts within each group, the sum of the axial lengths of the shallow portions of the identical inclined transverse cuts 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 portion or each portion to reduced depth of each inclined cross-section of the or at least one group includes at least one shallow portion and / or at least one moderately deep portion, each shallow portion having a depth less than or equal to 30%, preferably 25% of the sculpture height continuously along said shallow portion, and where 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 section further restores the initial drift rigidity without sacrificing external noise reduction. Each moderately deep section ensures the softening of the axially central portion of the tread to compensate for the relatively high intrinsic rigidity of the central tread material.

[0063] In cases where the reduced depth portion comprises at least one shallow portion and at least one moderately deep portion, these latter portions ensure the presence of inclined transverse cutouts extending over a significant axial length and thus being effective. 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 above concerning the depth of the reduced depth portion, 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 above concerning the depth of the reduced depth portion, the axial length of the shallow portion or each shallow portion 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 moderately deep portion or each moderately deep portion is greater than or equal to 30%, preferably 40% of the axial length of said reduced depth portion.

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

[0067] Such open, inclined transverse cutouts extend over a significant axial length and therefore effective.

[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) formed in said central rib.

[0071] Thanks to the edges of the secondary circumferential groove, lateral grip is increased when the tire is new and has relatively little wear. Due to its relatively shallow depth, the secondary circumferential groove 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 reduced even further, 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 comprising respectively a first and second lateral material having respectively 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, it will be possible to shift the overall performance compromise in favor of one of the desired performance characteristics, for example, rolling resistance performance.

[0076] In some embodiments, the first lateral material is identical to the second lateral material, and in particular G*1=G*2. In other embodiments, 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 includes 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 includes 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 stiffness between the central material and the lateral material, or between each first and second lateral material, is increased. Thus, for example, the rolling resistance of the tire is further reduced while still 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 includes 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, we will increase the external noise generated by the central portion which will have to be compensated all the more by the inclined cutouts.

[0081] In an embodiment allowing, for example, the reduction of 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 includes an axially lateral portion of the tread, the lateral material has a maximum dynamic loss tanDMAX23-l such that tanDMAX23-l < 0.20, preferably tanDMAX23-l < 0.15 and the central 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 includes first and second axially lateral portions of the tread, each first and second lateral material has respectively 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 allowing for increased drift rigidity of the tire and thus improving its behavior: - in the case where the tire includes 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 includes 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 allowing for increased fin rigidity, fin rigidity is favored at the expense of rolling resistance in a variant in which: - in the case where the tire includes an axially lateral portion of the tread, 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 includes first and second axially lateral portions of the tread layer, each first and second lateral material has respectively 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 is used with test specimens containing a baked compound extracted from the tire. The response of the specimens subjected to a sinusoidal alternating simple shear load at a frequency of 10 Hz is recorded under specified temperature conditions (here 23°C) according to ASTM DI349-99. A strain amplitude sweep is performed from 0.1% cc to 100% cc (forward cycle), then from 100% cc to 0.1% cc (reverse cycle), cc meaning peak-to-peak. The specimen has a cylindrical cross-section as described in ASTM D 5992-96 (2011 re-approved version, 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 represents a dynamic loss and is equal to the ratio G” / G’.The maximum value tanDMAX of the tangent tanD of the phase angle D observed on the deformation return cycle is recorded.

[0086] In preferred embodiments, the carving height belongs to an interval 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 of 4.0 mm at the carving height, preferably 5.0 mm at the carving height and more preferably 5.5 mm at the carving 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 sculpture height, preferably 90% of the sculpture 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 includes an axially lateral portion of the tread, the axially central portion of the tread is in contact with the axially lateral portion of the tread 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, the axially central portion of the tread 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] Where the tire includes an axially lateral portion of the tread, the arrangement of the interface in the axially central portion of the tread allows for a more distinct functionalization of the side of the tire carrying the axially lateral portion of the tread compared to the other side carrying the axially central portion. To this end, preferably, the axially lateral portion of the tread is arranged on the same side of the tire's median plane as the outer side of the tire, and the axially central portion is arranged on the same side of the tire's median plane as the inner side of the tire. By inner and outer sides, it is understood that the tire is designed so that one of its sides is arranged on the inner side and the other on the outer side.This orientation, specified by the tire manufacturer, ensures that the tire performs as intended. Indeed, mounting a tire with a different orientation than that specified by the manufacturer can lead to suboptimal vehicle handling. The outer side refers to the side of the tire that is fully visible from outside the vehicle when the tire is mounted. The inner side refers to the side of the tire that faces the wheel well of the vehicle on which it is mounted. Generally, the tire has markings indicating the inner and outer sides.

[0092] Still in the case where the tire includes an axially lateral portion of the tread, if we want 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 cases where the tire comprises first and second axially lateral portions of the tread, 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 decrease in drift stiffness. Conversely, too high a proportion of the central material reduces the rolling resistance gain.

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

[0096] In advantageous and optional first embodiments in which the tread comprises a radially inner layer arranged radially within the wearing course and distinct from the wearing course, the radially inner layer is arranged radially within: - the axially lateral portion of the tread layer in the case where the tire includes an axially lateral portion of the tread layer, or of each first and second axially lateral portion of the tread layer in the case where the tire includes first and second axially lateral portions of the tread layer, and - the axially central portion of the wearing course.

[0097] The radially inner layer optimizes certain tire performance characteristics, such as rolling resistance, wet grip, and handling. Therefore, the term "distinct from the tread layer" means that the radially inner layer is formed from one or more materials different from the lateral material or the first and second lateral materials.

[0098] In a first configuration of these first variants, the radially inner layer may be designed not to come into contact with the ground during tire rolling, at least until a regulatory wear threshold is reached. The radially inner layer will be referred to as the support layer. However, at specific points, i.e., over an axial length less than 10% of the axial length of the radially inner layer, the radially inner layer may be made to come into contact with the ground, particularly due to the relative control of industrial processes. Preferably, the radially inner layer is in contact with a crown reinforcement of the tire, for example as described below.

[0099] In a second configuration of these first variants, the radially inner layer may be designed to come into contact with the ground during tire 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 outermost radially layer and is designed to be in contact with the ground when the tire is new.

[0100] In advantageous and optional second variants, the tread comprises at least one radially inner layer, the or each radially inner layer is formed in the lateral material in the case where the tire includes an axially lateral portion of the tread or in the first and / or in the second lateral material of the tread in the case where the tire includes first and second axially lateral portions of the tread, the radially inner layer being arranged radially inside the axially central portion of the tread.

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

[0102] In other variants, the tread does not include an inner radial layer. Thus, the tread layer is in direct contact with the crown reinforcement of the tire, for example as described below.

[0103] Conventionally, the tire comprises a crown, two sidewalls, and two bead ribs, 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 internal to the crown reinforcement.

[0104] In embodiments enabling the performance of so-called radial tires, for example as defined by ETRTO, the carcass reinforcement comprises at least one carcass layer, the layer or each carcass layer comprising wire carcass reinforcement elements, each wire carcass reinforcement element extending substantially along a principal direction forming with the circumferential direction of the tire an angle, in absolute value, ranging from 80° to 90°. Alternatively, a variable angle ranging from 80° to 90° may be used 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 upon reading the following description, given solely by way of non-limiting example and made with reference to the drawings in which: - Figure [1] is a view, in a meridian cross-section, of a tire according to a first embodiment of the invention, - [Fig.2] is a top view of the tread of the tire in [Fig.1], - [Fig. 3] is a detailed view of the tire tread in Figures 1 and 2, illustrating some cross-sections, - [Fig. 4] is a detailed view of the tire tread in Figures 1 and 2, illustrating other cross-sections, - Figures 5 and 6 are views similar to that of [Fig. 1] of tires according to the 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 frame X, Y, Z has been represented corresponding to the usual directions respectively axial (Y), radial (Z) and circumferential (X) of a tire.

[0107] Figures 1 to 4 show a tire according to the invention, designated by the general reference numeral 10. The tire 10 has a substantially toroidal shape about 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 its new condition, i.e., having not yet been driven on. The tire 10 has an inner side INT and an outer side EXT.

[0108] The tire 10 includes a crown 12 comprising a tread 14 carrying a rolling surface 16 intended to come into contact with a ground during the rolling of the tire 10. The rolling surface 16 is axially delimited 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 the 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, including first, second, third and fourth main circumferential cutouts respectively designated by 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 outermost axially main circumferential cutouts of the tread 14 and below referred to as the outermost axially main circumferential cutouts 22, 24.

[0111] The first axially lateral portion Pib and the second axially lateral portion P2b are arranged axially outside the first axially external main circumferential cutout 22 and the second axially external main circumferential cutout 24, respectively. The first axially lateral portion Pib extends axially from the first axial edge 18 of the rolling surface 16 to the axially external 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 external edge 21 of the second axially external 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 carving height Hs, preferably from 5.0 mm to the carving height Hs, and more preferably from 5.5 mm to the carving height Hs. Each depth Hr is greater than or equal to 50%, preferably 75%, and more preferably 90% of the carving height Hs. Here, Hs = 6.5 mm, Hr = 6.0 mm for each first and second axially external 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 has a minimum width greater than or equal to 3.0 mm, preferably greater than or equal to 5.0 mm, and more preferably 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 reference numerals 32, 34, 36. Each central rib 32, 34, 36 is axially delimited 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 The transverse cuts 40, 40' formed in the central rib 34 are divided into two groups: firstly, the group of transverse cuts 40, all identical within the first group, and secondly, the group of transverse cuts 40', all identical within the second group and different from the transverse cuts 40 of the first group. The transverse cuts 42 are all identical and belong to the single group of transverse cuts formed in the central rib 36.

[0115] Each cross cut 38, 38', 40, 40', 42 extends between the 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 cut 42 belongs respectively to each main circumferential cut 28, 24 adjacent to the central rib 36. .

[0116] Each transverse cutout 38, 38' extends between its first and second ends along an average direction forming an angle respectively noted 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 cut 40, 40', 42 extends between its first and second ends along an average direction forming an angle respectively denoted A38', 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 cut 40, 40', 42 is said to be inclined.

[0118] With reference to Figures 2 and 3, each cross-section 38 of the first group includes a portion 380 referred to as a shallow portion having a depth less than or equal to 85%, preferably 80% and more preferably 75% of the sculpture height Hs, continuously along the shallow portion 380. Each shallow portion 380 comprises two portions 381, 383 referred to as shallow and a portion 382 referred to as 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 sculpture 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 sculpture 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 shallow portion 380 and here equal to 20% of the axial length L80 of the shallow 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 cross-section 38' of the second group comprises a portion 380' referred to as a reduced depth portion having a depth less than or equal to 85%, preferably 80% and more preferably 75% of the carving height Hs, continuously along the reduced depth portion 380'. Each reduced depth portion 380' comprises a portion 381' referred to as a shallow portion and a portion 382' referred to as a moderately deep portion 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 carving 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 carving 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 shallow 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 cut 40 of the first group comprises a portion 400 referred to as having a reduced depth having a depth less than or equal to 85%, preferably 80% of the carving height Hs continuously along the shallow section 400. Each shallow section 400 comprises a shallow section 401 and a moderately deep section 402 communicating directly with the shallow section 401. Each shallow section 401 has a depth H01 less than or equal to 30%, preferably 25% of the carving height Hs continuously along each shallow section 401. Each moderately deep section 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 carving height Hs continuously along the moderately deep section 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 shallow 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 cut 40' of the second group comprises a portion 400' referred to as a reduced depth portion 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 carving height Hs continuously along the reduced depth portion 400'. Each reduced depth portion 400' comprises a portion 402' referred to as a moderately deep portion. 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 carving 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 shallow-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 portions with reduced depth 400, 400' is greater than or equal to 80%, preferably to 120% and more preferably to 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 cut 42 comprises a portion 420 referred to as a reduced depth portion having a depth less than or equal to 85%, preferably 80% and more preferably 75% of the sculpture height Hs continuously along the shallow section 420. Each shallow section 420 comprises a shallow section 421 and a moderately deep section 422 communicating directly with the shallow section 421. Each shallow section 421 has a depth H21 less than or equal to 30%, preferably 25% of the carving height Hs continuously along each shallow section 421. Each moderately deep section 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 carving height Hs continuously along the moderately deep section 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 shallow 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 identical inclined transverse cutouts 42 within the group, the axial length L20 of the portion with reduced depth 420 is greater than or equal to 40%, preferably to 60% and more preferably to 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 portion with reduced depth 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 comprises respectively a first and a second lateral rib respectively designated by reference numerals 44, 46. The tread 14 comprises first and second transverse cutouts 48', 48”, 50', 50” formed at least partially 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 outside side EXT of the tire 10.

[0129] Each first transverse cut 48' extends along a mean direction forming an angle A48' of 10° with the axial direction Y and includes a portion 481' having a maximum depth H481' = 4.7 mm. Each first transverse cut 48' also includes a portion axially enlarged outside the portion formed in the first axially lateral portion Pib and having a width of 4.0 mm.

[0130] Each first transverse cut 48” extends along a mean direction forming an angle A48” equal to 10° with the axial direction Y and includes a portion 481” having a maximum depth H481”=4.7 mm. Each first transverse cut 48” also includes a portion 482” having a maximum depth H482”=1.4 mm.

[0131] Each second transverse cutout 50', 50" extends along a mean direction forming an angle A50', A50" of 10° with the axial direction Y and includes a portion 501', 501" having a maximum depth H501', H501" of 4.7 mm. Each second transverse cutout 50', 50" also includes a portion 502', 502" having a maximum depth H502', H502" of 1.4 mm. Each second transverse cutout 50' also includes a portion axially enlarged outside the portion formed in the second axially lateral portion P2b and having a width of 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, 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 separate from the tread layer 52.

[0135] The wearing course 52 comprises an axially central portion POc of the wearing course 52 and the first and second axially lateral portions Pic, P2c of the wearing course 52 arranged axially outside and on either side of the axially central portion POc of the wearing course 52. The axially central portion POc of the wearing course 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 wearing course 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 of the axially central portion POc of the wearing course 52. The axially central portion POc of the wearing course 52 includes 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 respectively each first and second main axially external circumferential cutout 22, 24 and arranged axially outside respectively of each first and second main axially external circumferential cutout 22, 24.

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

[0141] The axially central portion POc comprises a central material MO having a shear dynamic 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 comprises a first and second lateral material Ml, M2 respectively having a shear dynamic 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 here, Rolling resistance is prioritized over fin rigidity. The first and second lateral materials, M1 and M2, are identical here.

[0142] The dynamic shear moduli G*C, G*1, G*2 satisfy 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*' under imposed stress is determined using a Metravib VA4000 or DMA+450 type viscoelastic analyzer with specimens comprising a baked composition extracted from tires. The response of the specimens subjected to a sinusoidal alternating simple shear load at a frequency of 10 Hz under a force of 55 N is recorded. A temperature sweep is performed between -80°C and 80°C at a rate of 1.5°C / min, after the specimens have been previously accommodated to 100% peak-to-peak strain at a temperature less than or equal to 40°C, for example 23°C. 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].It should be noted that a force of 55 N, in the case of a specimen with a diameter of 10.00 mm, is equivalent to a stress with a peak-to-peak magnitude of 0.7 MPa. 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 The lateral M1, M2 temperature 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 viscoanalyzer with specimens containing a baked composition extracted from the tire. The response of the specimens subjected to sinusoidal alternating simple shear loading at a frequency of 10 Hz under a force of 55 N is recorded. A temperature sweep is performed between -80°C and 80°C at a rate of 1.5°C / min. The test specimen has a 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].It should be noted that a force of 55 N, in the case of a specimen with a diameter of 10.00 mm, is equivalent to a stress with a peak-to-peak magnitude of 0.7 MPa. The glass transition temperature Tg is taken to be the temperature at which 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 represents a dynamic loss and is equal to the ratio G” / G’.

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

[0147] [Tables] 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 the company Arlanxeo exhibiting a Mooney viscosity of 54 UM according to ASTM D 1646 (1+4 @ 100 °C), a vinyl content of 18%, an average styrene content of 27%, and a glass transition temperature of -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 classically known to those skilled in the art and include here in particular a protective wax, Nl,3-dimethylbutyl-N-phenylparaphenylenediamine, N-cy-clohexyl-benzothiazyl sulfenamide, diphenylguanidine, sulfur, stearic acid, zinc oxide, high oleic sunflower oil and an AMO70 processing agent.

[0149] The radially inner layer 54 comprises a material MS having a dynamic shear modulus G*S measured at 23°C at 10% strain and at a frequency of 10 Hz according to ASTM D 5992 - 96 such that G*S=1.67 MPa and a maximum dynamic loss tanDMAX23-S=0.13.The MS material is manufactured from a composition classically 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 MO, M1 and M2 materials.

[0150] With further reference to [Fig. 1], the apex 12 comprises an apex reinforcement 60 extending into the apex 12 in the circumferential direction X. The tire 10 also comprises a sealing layer 62 for an inflation gas intended to delimit an internal cavity closed with a mounting support for the tire 10 once the tire 10 is mounted on the mounting support, for example, a rim. The apex reinforcement 60 comprises a working reinforcement 64 and a shrink-fit reinforcement 66.

[0151] The working frame 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 shrink-fit armature 66 comprises at least one shrink-fit layer and here includes a 72-layer shrinkage layer.

[0153] The top reinforcement 60 is arranged radially inside the tread 14. The shrink-fit reinforcement 66, here the shrink-fit layer 72, is arranged radially outside the working reinforcement 64 and radially inside the tread 14. The shrink-fit reinforcement 66 is therefore radially interposed between the working reinforcement 64 and the tread 14. The shrink-fit layer 72 is therefore the outermost radially outermost layer of the top reinforcement 60.

[0154] The tire 10 comprises two sidewalls 74 extending radially inwards from the apex 12. The tire 10 further comprises two ribs 76 radially inwards from the sidewalls 74. Each sidewall 74 connects each rib 76 to the apex 12.

[0155] The tire 10 comprises a carcass reinforcement 78 anchored in each bead 76, in this case wound around two beads 80. The carcass reinforcement 78 extends radially in each sidewall 74 and axially in the crown 12 radially internally to 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, reinforcing layer 72, and carcass layer 82 comprises a polymer matrix, here an elastomeric matrix, in which one or more reinforcing elements of the corresponding layer are embedded. Thus, each working layer 68, 70 comprises, respectively, metallic working wire reinforcing elements; the reinforcing layer 72 comprises textile reinforcing wire reinforcing elements; and the carcass layer 82 comprises textile carcass wire reinforcing elements. The angles of the wire reinforcing elements and the materials of the wire reinforcing elements are described, for example, in WO2021250331.

[0157] We will now describe tires according to second, third and fourth embodiments with reference to figures 5 to 9. Elements analogous 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 but an axially central portion POc of the tread 52 and an axially lateral portion Pic arranged axially outside the axially central portion POc. The axially central portion POc of the tread 52 extends axially from the first axial edge 18 of the tread surface 16 arranged on the opposite side with respect to the median plane M of the axially lateral portion Pic to a contact interface 57 between the axially central portion POc and the axially lateral portion Pic. The axially lateral portion Pic of the wearing course 52 extends axially from the second axial edge 20 of the wearing 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 main axially external circumferential cutout 24 and arranged axially inside the main axially external 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 formed in each first and second lateral material M1, M2 of the tread 52. The radially inner layer 54 is arranged radially within the axially central portion POc of the tread 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 Figures 7 to 9 includes 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 cuts 42 which are all identical to each other within the first group and on the other hand the group of transverse cuts 42' which are all identical to each other within the second group and different from transverse cuts 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" made in the central rib 36.

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

[0166] With reference to figures 7 to 9, each cross cut 38, 38', 40, 40', 42, 42' comprises a portion with reduced depth 380, 380', 400, 400', 420, 420' comprising respectively a portion 381, 381', 401, 401', 421, 421' said to be moderately deep. Each shallow-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 sculpture height Hs continuously along each shallow-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 shallow portion 380, 380', 400, 400', 420, 420' and here equal to 100% of the axial length L80, L80', L00, L00', L20, L20' of each shallow portion 380, 380', 400, 400', 420, 420'.

[0168] The plurality of transverse cutouts formed 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 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 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 rib central 34.The plurality of transverse cutouts made 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 portions with reduced depth 420, 420' is greater than or equal to 40%, preferably to 60% and more preferably to 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 includes 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 along a mean direction forming an angle A48', A50' equal to 10° with the axial direction Y and includes a portion 481', 501' having a maximum depth H481', H501' equal to 4.5 mm. Each first and second transverse cutout 48', 50' also includes an axially enlarged 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 considered in which drift stiffness is prioritized over rolling resistance by modifying the materials M1, M1, M2 in the first embodiment. In this fifth embodiment of the materials MO, M1, M2, the dynamic shear moduli G*C, G*1, G*2 satisfy 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 Preferably 70% < G*1 / G*C < 85% and 70% < G*2 / G*C < 85%, and even more preferably, 50% < G*1 / G*C < 80% and / or 50% < G*2 / G*C < 80%, preferably 65% ​​< G*1 / G*C < 80% and 65% < G*2 / G*C < 80%, and more preferably 70% < G*1 / G*C < 80% and 70% < G*2 / G*C < 80%. In this fifth embodiment of the materials MO, M1, 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 under an 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 under an 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 shows the compositions from which the first and second lateral materials M1 and 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 pieces. 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 MS material of the radially inner layer 54 has a dynamic shear modulus G*S measured at 23°C at 10% strain and at a frequency of 10 Hz according to ASTM D 5992-96 such that G*S=1.88 MPa and a maximum dynamic loss tanDMAX23-S=0.12. The MS material is made from a composition as described above using N550 carbon black instead of N234 carbon black and the proportions of which a person skilled in the art can modify to obtain the dynamic properties described above.

[0179] COMPARATIVE TESTS

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

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

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

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

[0184] External noise was measured by driving the vehicle on a track conforming to ISO 10844 and certified by UTAC. A delimited measurement area 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 UN Regulation R51) and with the engine off (conditions similar to those used in UN Regulation RI 17). The raw noise measurement was then corrected for ground temperature as specified in UN Regulation RI 17. The two results from the tests under acceleration and with the engine off were then averaged.

[0185] The drift stiffness test is performed by rolling the tire under test on a rolling machine and applying a given load of 500 daN at a pressure of 2.9 bar. During rolling, the tire under test is subjected to the given load and rotated by +0.5° around the radial axis perpendicular to the contact patch between the tire and the ground, then by +1° around this axis. The measurement is then repeated for angles of -0.5° and -1° around this axis. The force generated by the tire on the rolling surface is then determined. From this, the drift stiffness, which is expressed in daN / ° for a given load, is deduced. The higher the drift stiffness, the better the tire is able to respond to the applied force and the better its road handling.

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

[0187] The results of the various tests are summarized in Tables 3 and 4 below, with reference to the control tires Tl, Tl'. The letter "R" or "R'" indicates that the test result is a reference value. The "+" sign indicates an improvement in performance compared to that of the control tire Tl, Tl'. Thus, a "+" sign for "External Noise" performance corresponds to a reduction in external noise generated by the tire and therefore to an improvement in external noise performance. A "+" sign for "Rolling Resistance" performance corresponds to a reduction in rolling resistance and therefore to an improvement in rolling resistance performance. A "+" sign for "Drift Stiffness" performance corresponds to an increase in drift stiffness and therefore to an improvement in the tire's handling performance.Similarly, the sign "-" indicates a deterioration in performance compared to that of the control tire Tl, Tl' and the sign "=" indicates that performance is maintained 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 performed clearly demonstrate an improvement in the overall performance compromise between external noise, drift stiffness, and rolling resistance compared to the control tire T1, and a reduction in external noise without any deterioration in rolling resistance compared to the control tire T2. However, a decrease in drift stiffness is acceptable in the 10-MDR1 tire. Indeed, since the tread stiffness of the control tire T1 is relatively high, the use of a less rigid, differentiated tread layer in the control tire T2 results, in exchange for a decrease in external noise and rolling resistance, in a reduction in drift stiffness, which is further reduced when the angled cutouts are added in the control tire T3. The presence of the shallower sections in the 10-MDR1 tire according to the invention makes it possible to restore some of the lost stiffness without losing the gains of the external 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 performed clearly demonstrate an improvement in the overall performance compromise between external noise, drift stiffness, and rolling resistance compared to the control tire T1, by improving external noise performance without deteriorating rolling resistance performance compared to the control tire T2. In the 10-MDR4 tire, it is acceptable to maintain rolling resistance performance without improving it. Indeed, since the tread stiffness of the control tire T1' is relatively low, using a more rigid axially central section in the control tire T2' results in an increase in external noise, in exchange for improved drift stiffness and maintained rolling resistance. External noise is reduced in the control tire T3' by adding angled cutouts, which nevertheless reduce drift stiffness without impacting rolling resistance.The presence of shallower sections in the 10-MDR4 tire further reduces external noise and restores the drift rigidity of the T2' reference tire without sacrificing 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 includes 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 includes a noise reduction device as described in WO2022 / 069822 or as described in EP1219944, EP1253025, EPI 184207, EPI 110763, EP1876038.

Claims

Demands

1. Tire (10) comprising a top (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) comprise respectively a central material (MO) and a lateral material (M1, M2;Ml) respectively exhibiting 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 :; - the first and second axially lateral portions (Pib, P2b) of the tread (14) arranged axially outside each of the first and second main axially external circumferential cutouts (22, 24), respectively, 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 wearing course (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 wearing course (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, referred to as inclined cutouts (40, 40', 42; 38, 38', 40, 40', 42; 42'), each inclined transverse cut made in said central rib (34, 36; 32, 34, 36) extending between the first and second extremities, each first and second extremity: - belonging to one of the main circumferential cutouts adjacent (22, 24, 26, 28) 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 cut (40, 40', 42; 38, 38', 40, 40', 42; 42') formed in said central rib (34, 36; 32, 34, 36) extending along an average 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), each inclined transverse cut (40, 40', 42; 38, 38', 40, 40', 42; 42') formed in said central rib (34, 36; 32, 34, 36) comprising at least one portion, referred to as reduced depth (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. Pneumatic (10) according to the preceding claim, wherein the or each portion with reduced depth (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 portion with reduced depth.

3. Pneumatic (10) according to any one of the preceding claims, 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. 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 along an average 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. Tire (10) according to any one of the preceding claims, wherein the inclined transverse cutout or cutout (40, 40', 42; 38, 38', 40, 40', 42; 42') extends along an average 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. Tire (10) according to any one of the preceding claims, wherein the axially central portion (POb) of the tread (14) comprises in total 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 with reduced depth (400, 400', 420; 380, 380', 400, 400', 420; 420').

7. Pneumatic (10) according to any one of the preceding claims, wherein the or each central rib i (34, 36; 32, 34, 36) comprising 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. Pneumatic (10) according to any one of the preceding claims, wherein the plurality of inclined transverse cutouts (40, 40', 42; 38, 38', 40, 40', 42; 42') formed in said central rib (34, 36; 32, 34, 36) is distributed into one or more groups of identical inclined transverse cutouts within the same group.

9. Pneumatic (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 shallow-depth portion (420) or the sum of the axial lengths of the shallow-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 portions with reduced depth (400, 400'; 380, 380', 400, 400', 420, 420') of the identical inclined transverse cuts 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 shallow-depth portion (400, 400', 420; 380, 380', 400, 400', 420; 420') of each inclined crosscut of the tire or at least one group comprises at least one shallow portion (401, 421) and / or at least one moderately deep portion (402, 402', 422; 381, 381', 401, 401', 421, 421'), the shallow portion having a depth less than or equal to 30%, preferably 25%, of the tread depth (Hs) continuously along said shallow portion, and / or the moderately deep portion having a depth less than or equal to 85%, preferably at 80%, more preferably at 75% and even more preferably at 60% of the sculpture height (Hs) continuously along said moderately deep portion.

11. Pneumatic (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. Pneumatic (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 shallow 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 shallow portion.

13. Pneumatic (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 principal circumferential cutouts (24, 26, 28).

14. Pneumatic (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 principal circumferential cutouts and a second end formed by a blind point of said central rib (34).

15. Pneumatic (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”) formed in said central rib (32, 34, 36).

Images