Tyre comprising pairs of transverse notches for sound dispersion

Abstract

The invention relates to a tyre (10) comprising transverse notches (80, 90) which are arranged in axially lateral portions (P1, P2). The transverse notches (80, 90) which are arranged in each axially lateral portion (P1, P2) comprise at least one sound dispersion pair of first and second transverse notches (801, 802, 811, 812). Each axially interior portion (861, 862, 871, 872) of each first and second transverse notch (801, 802, 811, 812) of the sound dispersion pair extends in an average direction which forms, respectively, a first non-zero average angle with the axial direction (Y) that is different from a second non-zero average angle (F1, F2, F11, F12) with the axial direction (Y).

Description

Pneumatics comprising pairs of transverse sound dispersion cutouts

[0001] The present invention relates to a tire for passenger vehicles. A tire is defined as 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 around a principal axis of the tire.

[0002] We know of the state of the art for a passenger vehicle tire sold under the MICHELIN® brand in the PRIMACY 4® range. Such a tire includes a tread designed to come into contact with the ground during the rolling of the tire via a tread surface.

[0003] The tread comprises principal circumferential cuts with a depth greater than or equal to 50% of the tread depth and includes first and second main circumferential cuts axially arranged on either side of the tire's median plane. The first and second main circumferential cuts axially are the outermost main circumferential cuts of the tread.

[0004] The tread comprises a first axially lateral portion arranged axially outside the first axially external main circumferential cutout, and a second axially lateral portion arranged axially outside the second axially external main circumferential cutout. The tread also comprises transverse cutouts formed at least partially within each first and second axially lateral portion.

[0005] Due to increasingly stringent regulations on external tire noise, state-of-the-art tires generate external noise that we aim to reduce as much as possible under normal operating conditions, as well as under conditions far removed from normal use. Operating conditions include, in particular, speed, pressure, tire load, and also the width of the rim on which the tire is mounted.

[0006] The invention therefore aims to reduce the external noise generated by the tire by reducing the noise generated by the transverse cutouts made in the first and second axially lateral portions in a very wide variety of terms of use.

[0007] To this end, the invention relates to a passenger vehicle tire comprising a tread intended to come into contact with the ground during tire rolling via a tread surface, the tread comprising: - main circumferential cutouts having a depth greater than or equal to 50% of the tread height comprising first and second main circumferential cutouts axially external arranged on either side of the median plane of the tire, the first and second main circumferential cutouts axially external being the outermost main circumferential cutouts axially of the tread, - a first axially lateral portion arranged axially outside the first main axially external circumferential cutout and extending axially from a first axial edge of the rolling surface to an axially external edge of the first main axially external circumferential cutout, - a second axially lateral portion arranged axially outside the second main axially external circumferential cutout and extending axially from a second axial edge of the tread surface to an axially external edge of the second main axially external circumferential cutout, the tread comprising at least transverse cutouts formed at least in part in at least one of the first and second axially lateral portions,at least one of the first and second axially lateral portions comprising an axial portion having an axial width equal to 50% of the axial width of said at least one of the first and second axially lateral portions and extending axially outwards from the axially outward edge of said first or second main axially outward circumferential cutout from which said at least one of the first and second axially lateral portions extends, each transverse cutout comprising an axially inward portion extending into the axial portion of said at least one of the first and second axially lateral portions, the transverse cutouts formed in said at least one of the first and second axially lateral portions comprising at least one pair of sound dispersion comprising a first and a second transverse cutout, each, axially internal portion of each first and second transverse cut of the sound dispersion pair having respectively a width La1, La2 such that: 1 < La1 / La2 < 2.5 in the case where La1 > 1.5 mm and La2 > 1.5 mm, 1 < La1 / La2 < 3.0 in the case where La1 > 1.5 mm and La2 < 1.5 mm, 1 < La1 / La2 < 4.0 in the case where La1 < 1.5 mm, each axially internal portion of each first and second transverse cut of the sound dispersion pair or pairs extends along an average direction forming respectively a first and a second non-zero average angle with the axial direction, the first average angle of the axially internal portion of the first transverse cut of the sound dispersion pair or pairs is different from the second average angle of the axially internal portion of the second transverse cut of said sound dispersion pair.

[0008] The invention makes it possible to reduce external noise generated by the transverse cutouts in at least one of the first and second axially lateral portions under a very wide variety of operating conditions. In other words, the tire according to the invention exhibits great versatility with regard to its external noise performance.

[0009] Indeed, the inventors behind the invention discovered that the external noise generated by the transverse cutouts was all the more significant as the edges of the transverse cutouts coincided with the edge of the contact area of ​​the tire.

[0010] The shape of the contact patch, and therefore its edge, depends on the operating conditions. Thus, under certain conditions, the crosscuts of a given tire may closely coincide with the edge of the contact patch, generating relatively significant external noise. Conversely, under other conditions, the crosscuts of the same tire may only slightly coincide, or not at all, with the edge of the contact patch, generating relatively low external noise. By using crosscuts with varying average angles of axial segments, the occurrence of coincidence between the edges of the crosscuts and the edge of the contact patch is reduced under all operating conditions, and therefore the external noise generated by the tire is minimized.

[0011] This explains the sound dispersion function associated with the pair of transverse cutouts and their portions which allow the noise generated by the transverse cutouts to be dispersed in a very wide variety of usage conditions.

[0012] The characteristic whereby each axially interior portion of each first and second transverse cut of the sound dispersion pair has a width La1, La2 respectively such that: 1 < La1 / La2 < 2.5 in the case where La1 > 1.5 mm and La2 > 1.5 mm, 1 < La1 / La2 < 3.0 in the case where La1 > 1.5 mm and La2 < 1.5 mm, 1 < La1 / La2 < 4.0 in the case where La1 < 1.5 mm, allows us to consider transverse cuts with comparable widths and therefore comparable behaviors without the cuts having strictly the same width.

[0013] In some variations, the inner axial portion may not open into one of the first and second main circumferential grooves located on the outer axial side. These variations are referred to as blind transverse grooves. In other variations, the inner axial portion opens into one of the first and second main circumferential grooves located on the outer axial side. This design promotes tread movement compared to blind transverse grooves, which improves tire flatness and, consequently, rolling resistance.

[0014] Conventionally, the tread is axially delimited by the first and second axial edges. These edges are determined on a tire mounted on a nominal rim and inflated to the nominal pressure as defined by the European Tyre and Rim Technical Organisation (ETRTO) standard, 2021. The first and second axial edges of the tread are positioned on either side of the tire's median plane and are formed by lines substantially parallel to the tire's circumferential direction. If there is a clear boundary between the tread and the rest of the tire, the first and second axial edges of the tread are determined simply.In cases where the tread surface is continuous with the outer surfaces of the tire sidewalls, the first and second axial edges can be determined, for example, by considering that each first and second axial edge passes, in each meridian plane, through the point for which the angle between the tangent to the tread surface and a line parallel to the axial direction passing through that point is equal to 30°. When there are several points on a meridian plane for which this angle is equal in absolute value to 30°, the radially outermost point is retained.

[0015] The average angle of a portion is determined by taking the straight line extending between two endpoints of the portion, the two endpoints being located at ends of each portion, equidistant from the leading and trailing edges of each end of the portion.

[0016] Naturally, the transverse cuts, particularly the first, second, and optionally third transverse sound dispersion cuts, are distinct from one another. Thus, the transverse cuts, particularly the first, second, and optionally third transverse sound dispersion cuts, are circumferentially offset from one another. The transverse cuts, particularly the first, second, and optionally third transverse sound dispersion cuts, therefore do not communicate axially with each other. Thus, either the transverse cuts, particularly the first, second, and optionally third transverse sound dispersion cuts, do not communicate with each other, or, if they do, it is via a cut that is not a transverse cut, for example, a circumferential cut.Thus, the transverse cuts, in particular the first, second and optionally third transverse sound dispersion cuts, are not the axial extension of one another.

[0017] The first and second axially lateral portion of the tread may of course include other transverse cutouts which do not have the characteristics of the transverse cutouts according to the invention, in particular the characteristics relating to the width of their axially inner portion, as well as circumferential cutouts having a depth strictly less than 50% of the tread height.

[0018] A cutout or a portion of a cutout has two main characteristic dimensions on the running surface: a width and a curvilinear length such that the curvilinear length is at least twice the width. A cutout or a portion of a cutout is therefore delimited by at least two main lateral faces that determine its curvilinear length and are connected by a base, the two main lateral faces being separated by a non-zero distance, called the width of the cutout or portion of the cutout.

[0019] The width of a cut or portion of a cut on a new tire is the maximum distance between the two main sidewalls, measured, by default and in cases where the cut or portion of a cut does not include a chamfer, at a radial dimension coinciding with the tread surface, and by default and in cases where the cut or portion of a cut includes a chamfer, at the outermost radial dimension of the cut or portion of the cut and radially inner dimension of the chamfer. The width is measured substantially perpendicular to the main side faces. If a width other than the default width is specified, for example a width at a particular dimension, the width is equal to the distance between the two main side faces at the particular dimension of the cutout or portion of the cutout.

[0020] The depth of a cut or portion of a cut on a new tire is the maximum radial distance between the bottom of the cut or portion and its projection onto the ground when the tire is in motion. The maximum depth of the cuts is called the tread depth.

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

[0022] A transverse cut is such that the cut extends along a mean direction forming an angle strictly greater than 30°, preferably greater than or equal to 45°, with the circumferential direction of the tire, i.e., forming an angle less than or equal to 60°, preferably strictly less than 45°, with the axial direction of the tire. The mean direction is the shortest curve joining the two ends of the cut and parallel to the tread surface. A cut or a transverse 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 along the length of the transverse cut or portion.A transverse cut can also be discontinuous, that is, interrupted by one or more blocks of sculpture and / or one or more cuts so that the two main lateral faces determining its length are interrupted by one or more blocks of sculpture and / or one or more cuts.

[0023] A circumferential cut is such that the cut or portion extends along a mean direction forming an angle of 30° or less, preferably 10° or less, 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. The mean direction is the shortest curve joining the two ends of the cut and parallel to the tread surface. In the case of a continuous circumferential cut, the two ends coincide and are joined by a curve making a complete rotation of the tire. A circumferential cut can 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-. said interrupted by one or more blocks of sculpture and / or one or more cuts so that the two main lateral faces determining its length are interrupted by one or more blocks of sculpture and / or one or more cuts over the whole of one turn of the tire.

[0024] In the case of a cross cut or a portion of a cross cut, the lateral faces are called the leading face and the trailing face and each is provided respectively with a leading edge and a trailing edge, the leading edge being the edge which, for a given circumferential line, enters the contact area before the trailing edge.

[0025] In embodiments that optionally improve braking on dry surfaces, each transverse cut is provided with chamfers. A chamfer of a transverse cut can be a straight chamfer or a rounded chamfer. A straight chamfer is formed by a flat face inclined relative to the leading or trailing face it extends to the leading or trailing edge circumferentially delimiting the transverse cut. A rounded chamfer is formed by a curved face connecting tangentially to the leading or trailing face it extends. A chamfer of a transverse cut is characterized by a height and a width equal, respectively, to the radial distance and the distance along a direction perpendicular to the leading or trailing faces between the point where the leading or trailing face extended by the chamfer intersects the leading or trailing edge circumferentially delimiting the transverse cut.

[0026] In certain embodiments that optionally improve wet braking and dry lateral grip, at least one of the main circumferential cutouts is fitted with chamfers. A chamfer on a circumferential cutout can be a straight chamfer or a rounded chamfer. A straight chamfer is formed by a flat face inclined relative to the axially inner and outer faces it extends to the axially inner or outer edge that axially delimits the circumferential cutout. A rounded chamfer is formed by a curved face that connects tangentially to the axially inner or outer face it extends.A chamfer of a circumferential cut is characterized by a height and a width equal respectively to the radial distance and the axial distance between the common point between the axially internal or external face extended by the chamfer and the axially internal or external edge axially delimiting the circumferential cut.

[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 classically used by the person skilled in the art: an axial direction, a circumferential direction and a radial direction.

[0028] Axial direction refers to the direction substantially parallel to the axis of revolution of the tire, that is, 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 crown reinforcement.

[0032] The circumferential equatorial plane of the tire (denoted E) is, in a meridional cross-sectional plane, the plane passing through the tire's equator, perpendicular to the median plane and the radial direction. The tire's equator, in a meridional cross-sectional plane (a plane perpendicular to the circumferential direction and parallel to the radial and axial directions), is the axis parallel to the tire's axis of rotation 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, the distance between these two points being equal to H.

[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] Radially inside and radially outside refer to the area closest to and further from the tire's axis of rotation, respectively. Axially inside and axially outside refer to the area closer to and further from the tire's median plane, respectively.

[0035] The bead is the portion of the tire designed to allow the tire to be attached to a mounting surface, such as a wheel with a rim. Each bead is specifically designed to make contact with a hook on the rim, enabling it to be secured.

[0036] Any range of values ​​designated by the expression "between a and b" represents the domain of values ​​from greater than a to less than b (that is, excluding bounds a and b), while any range of values ​​designated by the expression "from a to b" means the domain of values ​​ranging from a to b (that is, including the strict bounds a and b).

[0037] The tires are, in preferred embodiments of the invention, intended for passenger vehicles as defined in the European Tyre and Rim Technical Organisation or "ETRTO" standard, 2021. Such a tire has a cross-section in a meridian cutting plane characterized by a section height H and a nominal section width or flange size S as defined in the European Tyre and Rim Technical Organisation or "ETRTO" standard, 2021 such that the H / S ratio, expressed as a percentage, is at most equal to 90, preferably at most equal to 70 and is at least equal to 30, and the nominal section width S is at least equal to 115 mm, preferably at least equal to 175 mm and at most equal to 385 mm, preferably at most equal to 315 mm. In addition, the diameter at the hook D, defining the diameter of the tire mounting rim, is at least 12 inches, preferably at least 16 inches and at most 24 inches.

[0038] In preferred embodiments of the invention, the tires are summer tires. Summer tires are defined as tires that are neither all-season tires nor winter tires.

[0039] Winter tires are identified by the M+S marking (M+S stands for "Mud + Snow") and / or the 3PMSF marking (3PMSF stands for "3 Peak Mountain Snow Flake"). All-season tires, due to their performance on snow, also display the M+S and / or 3PMSF markings. Summer tires, however, do not have the M+S or 3PMSF markings.

[0040] In an optimized but optional manner, the tread includes at least transverse cutouts formed in each first and second axially lateral portion, each first and second axially lateral portion comprising an axial portion having an axial width equal to 50% of the axial width respectively of each first and second axially lateral portion and extending axially outwards from each axially inner edge respectively of each first and second main circumferential cutout axially outwards from which each first and second axially lateral portion extends respectively, each transverse cutout comprising an axially inner portion extending into the axial portion of said first or second axially lateral portion,the transverse cutouts formed in the first axially lateral portion comprising at least one first pair of sound dispersion comprising a first and a second transverse cutouts, the transverse cutouts formed, in the second axially lateral portion comprising at least a second pair of sound dispersion comprising a first and a second transverse cutouts, each axially internal portion of each first and second transverse cutout of each first and second pair of sound dispersion having respectively a width La1, La2 such that: 1 < La1 / La2 < 2.5 in the case where La1 > 1.5 mm and La2 > 1.5 mm, 1 < La1 / La2 < 3.0 in the case where La1 > 1.5 mm and La2 < 1.5 mm, 1 < La1 / La2 < 4.0 in the case where La1 < 1.5 mm, each axially internal portion of each first and second transverse cut of each first and second sound dispersion pair extends along an average direction forming respectively a first and second non-zero average angle with the axial direction, the first average angle of the axially internal portion of the first transverse cut of each first and second sound dispersion pair is different from the second average angle of the axially internal portion of the second transverse cut respectively of each first and second sound dispersion pair.

[0041] In preferred embodiments, each axially interior portion of each first and second transverse cut of the sound dispersion pair has a width La1, La2 respectively such that: 1 < La1 / La2 < 2.1 in the case where La1 > 1.5 mm and La2 > 1.5 mm, 1 < La1 / La2 < 2.4 in the case where La1 > 1.5 mm and La2 < 1.5 mm, 1 < La1 / La2 < 3.2 in the case where La1 < 1.5 mm.

[0042] In advantageous embodiments, the axially inner portion of each first and second transverse cut of the sound dispersion pair(s) has a width ranging from 0.2 mm to 2.2 mm, preferably from 0.2 mm to 1.0 mm, more preferably from 0.2 mm to 0.6 mm, and even more preferably from 0.2 mm to 0.5 mm. By limiting the width of the axial portion, the noise generated by the sound dispersion cut is reduced.

[0043] In advantageous embodiments, the axially inner portion of each first and second transverse cut of the sound dispersion pair or pairs has a depth ranging from 2.0 mm to 5.5 mm, preferably ranging from 3.0 mm to 5.0 mm.

[0044] Optionally and preferably, each main circumferential cutout has a depth greater than or equal to 75% and more preferably to 90% of the sculpture height.

[0045] In embodiments in which the main circumferential cutouts are relatively deep, each main circumferential cutout has a depth ranging from 4.0 mm to the carving height, preferably ranging from 5.0 mm to the carving height and more preferably ranging from 5.5 mm to the carving height.

[0046] In embodiments in which the main circumferential cutouts are relatively wide main circumferential grooves, each main circumferential cutout has an axial width greater than or equal to 1.0 mm, preferably greater than or equal to 5.0 mm and more preferably ranging from 5.0 mm to 20.0 mm.

[0047] In optional embodiments, it may also be envisaged that at least one of the first and second axially lateral portions includes at least one additional circumferential cutout having a depth strictly less than 50% of the sculpture height, preferably less than or equal to 30% of the sculpture height and more preferably ranging from 10% to 30% of the sculpture height.

[0048] Optionally but advantageously, each first and second non-zero mean angle of the axially interior portion of each first and second cross-section of the sound dispersion pair or pairs is less than or equal to 50°, preferably 40° and more preferably ranges from 5° to 40°.

[0049] If the average angle is too small, there is an increased risk of the edges of the transverse sound dispersion grooves coinciding with the edge of the tire contact patch under most operating conditions, thus increasing tire noise. Conversely, if the average angle is too large, there is an increased risk of tire pull, meaning the risk of generating a force along the tire's axial direction.

[0050] In some embodiments, the absolute difference between the first mean angle and the second mean angle of each sound dispersion pair is less than or equal to 40°, preferably 30°. Even if the operating conditions of the tire may be significantly different, it remains exceptional for these operating conditions to be so different as to necessitate an excessively large difference between the angle values.

[0051] In still other embodiments, the absolute difference between the first mean angle and the second mean angle of each sound dispersion pair is greater than or equal to 5°, preferably 10°. Conversely, the greater the difference between the angles, the more the conditions under which one The noise reduction measures can vary.

[0052] In embodiments in which the invention is applied to a significant number of transverse cuts of the first and second axially lateral portion(s), the first and second mean angles being equal to values ​​taken from a list of at least the first and second different values: - the average angle of the axially internal portion of at least 25%, preferably at least 50% and more preferably at least 75% of the transverse cuts of said at least one of the first and second axially lateral portions is equal to one of at least first and second different values, - each axially internal portion of each transverse cut whose mean angle is equal to one of at least the first and second different values ​​has a width La such that: o 1 < Lamax / La < 2.5, preferably 1 < Lamax / La < 2.1 in the case where Lamax > 1.5 mm and La > 1.5 mm, o 1 < Lamax / La < 3.0, preferably 1 < Lamax / La < 2.4 in the case where Lamax > 1.5 mm and La < 1.5 mm, o 1 < Lamax / La < 4.0, preferably 1 < Lamax / La < 3.2 in the case where Lamax < 1.5 mm, with Lamax being the maximum value of the widths of the axially internal portions of at least 25%, preferably at least 50% and more preferably at least 75% of the transverse cuts whose mean angle is equal to one of at least the first and second different values.

[0053] Thus, by increasing the number of pairs of cross-sections with different mean angles, noise dispersion is promoted under different usage conditions.

[0054] In these embodiments, it is advantageous that: - each mean angle of the axially internal portion of at least 15%, preferably at least 25%, of the transverse cuts of said at least one of the first and second axially lateral portions is equal to the first value, and - each mean angle of the axially internal portion of at least 15%, preferably at least 25% of the transverse cuts of said at least one of the first and second axially lateral portions is equal to the second value.

[0055] This ensures that a significant number of cross-sections presents a mean angle value equal to one of the first and second values ​​and at the same time that each first and second value is reached by a significant number of crosscuts compared to the total number of crosscuts of the or each first and second axially lateral portion.

[0056] In optional embodiments allowing for even more advantageous noise dispersion, the transverse cutouts formed at least partially in said at least one of the first and second axially lateral portions comprise at least one sound dispersion triplet comprising a first, second and third transverse cutout, each first, second and third transverse cutout of the sound dispersion triplet or each sound dispersion triplet comprising an axially internal portion extending into the axial portion of said at least one of the first and second axially lateral portions, each axially internal portion of each first, second and third transverse cutout of the sound dispersion triplet having respectively a width La1 > La2 > La3 such that: 1 < La1 / La3 < 2.5, preferably 1 < La1 / La3 < 2.1 in the case where La1 > 1.5 mm and La3 > 1.5 mm, 1 < La1 / La3 < 3.0, preferably 1 < La1 / La3 < 2.4 in the case where La1 > 1.5 mm and La3 < 1.5 mm, 1 < La1 / La3 < 4.0, preferably 1 < La1 / La3 < 3.2 in the case where La1 < 1.5 mm, each axially internal portion of each first, second and third transverse cut of the sound dispersion triplet extends along an average direction forming respectively a first, second and third non-zero average angle with the axial direction, the first, second and third average angles of the axially internal portions of the first, second and third transverse cuts of the sound dispersion triplet are two by two different.

[0057] In other words, the first mean angle is different from the second mean angle, the second mean angle is different from the third mean angle, and the first mean angle is different from the third mean angle.

[0058] By using three mean angle values, we can account for a greater number of operating conditions in which effective noise dispersion is achieved. In the case of a mold with several different patterns, it is advantageous to choose a number of mean angles equal to the number of different patterns in order to limit the complexity of the mold design and ensure that at each The pattern corresponds to one and only one average angle.

[0059] In a manner analogous to what is optionally provided for pairs of cross-cuts, each first, second and third non-zero mean angle of the axially interior portion of each first, second and third cross-cut of the sound dispersion triplet or triplet is less than or equal to 50°, preferably 40° and more preferably ranges from 5° to 40°.

[0060] Similar to what is optionally provided for pairs of cross-sections, each difference in absolute value between: - the first mean angle and the second mean angle of the sound dispersion triplet(s), - the second mean angle and the third mean angle of the sound dispersion triplet(s), - the first mean angle and the third mean angle of the sound dispersion triplet(s), is less than or equal to 40°, preferably 30° and / or is greater than or equal to 5°, preferably 10°.

[0061] Similar to what is optionally provided for pairs of cross-sections, the first, second, and third mean angles are equal to values ​​taken from a list of at least two different first, second, and third values: - the average angle of the axially internal portion of at least 25%, preferably at least 50% and more preferably at least 75% of the transverse cuts of said at least one of the first and second axially lateral portions is equal to one of at least the first, second and third different values, - Each axially internal portion of each transverse cut whose mean angle is equal to at least one of the first, second, and third different values ​​has a width La such that: o 1 < Lamax / La < 2.5, preferably 1 < Lamax / La < 2.1 in the case where Lamax > 1.5 mm and La > 1.5 mm, o 1 < Lamax / La < 3.0, preferably 1 < Lamax / La < 2.4 in the case where Lamax > 1.5 mm and La < 1.5 mm, o 1 < Lamax / La < 4.0, preferably 1 < Lamax / La < 3.2 in the case where Lamax < 1.5 mm, with Lamax being the maximum value of the widths of the axially internal portions of at least 25%, preferably at least 50% and more preferably at least 75% of the cross-sections whose average angle is equal to at least one of the first, second and third values ​​different in pairs.

[0062] Similarly to the optional provisions for pairs of transverse cutouts, - each average angle of the axially internal portion of at least 15%, preferably at least 25% of the transverse cuts of said at least one of the first and second axially lateral portions is equal to the first value, - each mean angle of the axially internal portion of at least 15%, preferably at least 25%, of the transverse cuts of said at least one of the first and second axially lateral portions is equal to the second value, and - each mean angle of the axially internal portion of at least 15%, preferably at least 25% of the transverse cuts of said at least one of the first and second axially lateral portions is equal to the third value.

[0063] In some embodiments, the first and second transverse cuts of the or each pair of sound dispersion are circumferentially adjacent.

[0064] This reduces the likelihood that two circumferentially adjacent transverse cutouts will generate the same external noise under given operating conditions. It also promotes the dispersion of noise generated under given operating conditions, particularly if these conditions result in the edges of at least some of the transverse cutouts coinciding with the edge of the tire contact patch.

[0065] Circumferentially adjacent, we understand that no transverse cutout has an axially interior portion with a width La such that: 1 < La1 / La2 < 2.5, preferably 1 < La1 / La2 < 2.1 in the case where La1 > 1.5 mm and La2 > 1.5 mm, 1 < La1 / La2 < 3.0, preferably 1 < La1 / La2 < 2.4 in the case where La1 > 1.5 mm and La2 < 1.5 mm, 1 < La1 / La2 < 4.0, preferably 1 < La1 / La2 < 3.2 in the case where La1 < 1.5 mm, is circumferentially arranged between the transverse cuts of the sound dispersion pair.

[0066] Similarly, in the case of a triplet of circumferentially adjacent transverse cuts, some embodiments are such that the first, second and third transverse cuts of the or each triplet of sound dispersion are circumferentially adjacent.

[0067] Circumferentially adjacent, we will understand, in a manner analogous to a sound dispersion pair, that no transverse cutout presenting an axially internal portion having a width La such that: 1 < La1 / La3 < 2.5, preferably 1 < La1 / La3 < 2.1 in the case where La1 > 1.5 mm and La2 > 1.5 mm, 1 < La1 / La3 < 3.0, preferably 1 < La1 / La3 < 2.4 in the case where La1 > 1.5 mm and La2 < 1.5 mm, 1 < La1 / La3 < 4.0, preferably 1 < La1 / La3 < 3.2 in the case where La1 < 1.5 mm, is circumferentially arranged between the transverse cuts of the sound dispersion triplet.

[0068] Optionally, but advantageously, the absolute difference between the first mean angle and the second mean angle of the sound dispersion pair of first and second circumferentially adjacent crosscuts is less than or equal to 20°.

[0069] Indeed, if axial sections with significantly different mean angles belong to circumferentially adjacent transverse sound dispersion cutouts, there is a risk of excessive rigidity difference between adjacent tread blocks, which can lead to uneven wear. Here, by limiting the difference between these mean angles, the rigidity difference between these adjacent tread blocks is reduced, thus promoting even tread wear.

[0070] Optionally, but advantageously, the absolute difference between the first mean angle and the second mean angle of the sound dispersion pair of first and second circumferentially adjacent crosscuts is greater than or equal to 5°, preferably 10°.

[0071] By sufficiently differentiating the average angles, the noise generated by the adjacent pneumatic cross-sections is reduced under sufficiently different usage conditions.

[0072] Similar to what is optionally provided for pairs of transverse cutouts, the absolute difference between one of the first, second, and third mean angles and at least one of the other first, second, and third mean angles of the sound dispersion triplet of first, second, and third circumferentially transverse cutouts adjacent is less than or equal to 20° and / or greater than or equal to 5°, preferably 10°.

[0073] In preferred embodiments, the tread comprising N circumferentially adjacent transverse cutouts forming N pairs of circumferentially adjacent transverse cutouts in a circumferential direction of rotation around the tire, the width La of each axially inner portion of each of the N circumferentially adjacent transverse cutouts is such that: 1 < Lamax / La < 2.5, preferably 1 < Lamax / La < 2.1 in the case where Lamax > 1.5 mm and La > 1.5 mm, 1 < Lamax / La < 3.0, preferably 1 < Lamax / La < 2.4 in the case where Lamax > 1.5 mm and La < 1.5 mm, 1 < Lamax / La < 4.0, preferably 1 < Lamax / La < 3.2 in the case where Lamax < 1.5 mm, with Lamax being the maximum value of the widths of the axially internal portions of the transverse cuts of the N pairs of circumferentially adjacent transverse cuts, the mean angles of the axially internal portions of at least 25%, preferably at least 35% of the N pairs of the N circumferentially adjacent transverse cuts are different.

[0074] In other words, at least 25%, at least 50% of the N pairs of circumferentially adjacent cross-sections are sound dispersion pairs.

[0075] Similarly, in the case of a triplet of circumferentially adjacent transverse cutouts, certain embodiments are such that, the tire comprising N circumferentially adjacent transverse cutouts and N triplets of circumferentially adjacent transverse cutouts in a circumferential direction of rotation around the tire, the width La of each axially interior portion of each of the N circumferentially adjacent transverse cutouts is such that: 1 < Lamax / La < 2.5, preferably 1 < Lamax / La < 2.1 in the case where Lamax > 1.5 mm and Lai > 1.5 mm, 1 < Lamax / La < 3.0, preferably 1 < Lamax / La < 2.4 in the case where Lamax > 1.5 mm and Lai < 1.5 mm, 1 < Lamax / La < 4.0, preferably 1 < Lamax / La < 3.2 in the case where Lamax < 1.5 mm, with Lamax being the maximum value of the widths of the axial portions of the cross cuts of the N triplets of circumferentially adjacent cross cuts, the mean angles of the axial portions of at least 15%, preferably at least 20% of the N triplets of the N circumferentially adjacent cross cuts are different in pairs.

[0076] In other words, at least 15%, at least 20% of the N pairs of circumferentially adjacent cross-sections are sound dispersion triplets.

[0077] In preferred variants allowing for further improvement of tread wear uniformity, the tire comprising several pairs of sound dispersion, each pair of sound dispersion comprising first and second circumferentially adjacent transverse cutouts in a circumferential direction of rotation around the tire, the absolute difference between the first mean angle and the second mean angle of at least 25%, preferably at least 50% and more preferably at least 75% of said pairs of sound dispersion of first and second circumferentially adjacent transverse cutouts is less than or equal to 20°.

[0078] In preferred variants allowing for further reduction of the noise generated by the tire under sufficiently different conditions of use, the tire comprising several pairs of sound dispersion, each pair of sound dispersion comprising first and second circumferentially adjacent transverse cuts in a circumferential direction of rotation around the tire, the difference in absolute value between the first mean angle and the second mean angle of at least 25%, preferably at least 50% and more preferably at least 75% of said pairs of sound dispersion of first and second circumferentially adjacent transverse cuts is greater than or equal to 5°, preferably 10°.

[0079] In a manner analogous to what is optionally provided for pairs of cross cuts, the difference in absolute value between one of the first, second and third mean angles and at least one of the other first, second and third mean angles of at least 25%, preferably at least 50% and more preferably at least 75% of said sound dispersion triplets of first, second and third circumferentially adjacent cross cuts is less than or equal to 20° and / or greater than or equal to 5°, preferably 10°.

[0080] In preferred but optional embodiments, each axially interior portion of each cross-section of the or each pair or The sound dispersion triplet extends along an axial length equal to at least 20%, preferably at least 35% of the axial length of the part of each transverse cut of the pair or sound dispersion triplet provided in at least one of the first and second axially lateral portions.

[0081] The greater the axial length of the axial portion, which participates in the dispersion of noise, the more the noise generated by each transverse cut of the sound dispersion pair or triplet is dispersed.

[0082] In some embodiments, the axially inner portion does not extend along the entire length of the axial portion of at least one of the first and second axially lateral portions. In other embodiments, the axially inner portion extends along the entire length of the axial portion of at least one of the first and second axially lateral portions.

[0083] Since the tread is intended to come into contact with the ground during the rolling of the tire via the tread surface, the determination of the curvilinear length is therefore made in the relevant portion of the tread and thus limited to the tread surface and therefore to the first and second axially lateral portions.

[0084] The axial length of a part of a cross-section or a portion of a cross-section, whether it belongs to a sound dispersion pair or triplet or not, is the length measured along the axial direction between the two ends of the part of the cross-section or portion.

[0085] In some variants, each cross-section of the sound dispersion pair or triplet includes an axially external portion communicating with the axially internal portion, arranged axially outside the axially internal portion, the axially external portion being the outermost axial portion of each cross-section of the sound dispersion pair or triplet provided in at least one of the first and second axially lateral portions.

[0086] In these variants, preferably, the axially outer portion of each cross-section of the sound dispersion pair or triplet extends along an average direction forming a mean angle with the axial direction strictly less than the mean angle formed by the mean direction of the axially inner portion of at least one of the cross-sections of the sound dispersion pair or triplet.

[0087] Indeed, in the portion of the running surface corresponding to the axial portion, the contact area is rectilinear. Conversely, in the portion of the surface Because the contact patch corresponds to the outer axial portion, the contact area is rounded due to the tire's curvature. Thus, the leading edge of the inner axial portion makes gradual contact with the ground over a relatively long period of time. This is due to the relatively large angle and the straightness of the contact patch in the axial portion, which limits noise compared to a cut with a near-zero average angle to the axial direction, where the entire leading edge makes contact with the ground simultaneously. Similarly, due to the smaller angle and the rounded contact patch in the outer axial portion, the leading edge also makes gradual contact with the ground, which also helps to reduce noise.

[0088] Thus, advantageously, in order to reduce as much as possible the noise generated by each axially external portion, the average angle formed by the average direction of the axially external portion with the axial direction is optionally strictly less than 25°, preferably less than or equal to 20° and more preferably less than or equal to 15°.

[0089] Preferably, the mean angle formed by the mean direction of the axially outer portion with the axial direction is substantially the same for each cross-section of the sound dispersion pair or triplet.

[0090] Furthermore, in optional embodiments, the outer axial portion has a width strictly greater than the width of the axial portion. Thus, the wide outer axial portion allows for efficient evacuation of water away from the contact area between the tread and the ground on which the tire travels.

[0091] Optionally, the axially outer portion has a width ranging from 0.7 mm to 5.0 mm, preferably from 1.0 mm to 5.0 mm, preferably from 2.0 mm to 4.5 mm.

[0092] Optionally, the axially external portion has a depth ranging from 2.0 mm to 5.5 mm.

[0093] In other embodiments, each cross-section of the sound dispersion pair or trio includes an axially terminal portion located axially outside at least one of the first and second axially lateral portions and communicating with the wide axially external portion. This facilitates the evacuation of water from the contact area between the tread and the ground on which the tire rolls.

[0094] The characteristics described above relate to the transverse cuts made in at least one of the first and second portions axially lateral. In certain preferred embodiments, they can also be applied to the transverse cuts of the or each pair or triplet of sound dispersion provided in each first and second axially lateral portion.

[0095] Conventionally, a tire comprises a crown, two sidewalls, and two beads, with each sidewall connecting each bead to the crown. Also conventionally, the crown includes the tread and a crown reinforcement arranged radially within the tread. The tire also includes a carcass reinforcement anchored in each bead and extending radially into each sidewall and axially into the crown, radially internal to the crown reinforcement.

[0096] Conventionally, the top reinforcement comprises at least one top layer containing reinforcing elements. These reinforcing elements are preferably textile or metallic wire elements.

[0097] 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 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°.

[0098] 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 top view of the tread of a tire according to the invention, Figure 2 is a view, in a meridian cutting plane parallel to the axis of rotation of the tire, of the tire of Figure 1, Figure 3 is a cutaway view of the tire of Figure 1 illustrating the arrangement of the wire reinforcement elements in and under the crown, Figure 4 is a view similar to that of Figure 1 of a test tire allowing to demonstrate the interest of the invention, and Figures 5 and 6 illustrate the results of comparative noise tests between the tire according to the invention of Figure 1 and the test tire of Figure 4.

[0099] In the figures relating to the tire, an X, Y, Z coordinate system has been represented. corresponding to the usual directions respectively axial (Y), radial (Z) and circumferential (X) of a tire.

[0100] Figures 1 to 3 show a tire according to the invention, designated by the general reference numeral 10. Tire 10 has a substantially toroidal shape around an axis of revolution substantially parallel to the axial direction Y. Tire 10 is intended for a passenger vehicle and has dimensions 205 / 55 R16. Tire 10 is a summer tire. In the various figures, tire 10 is shown in its new condition, i.e., having not yet been driven on.

[0101] With reference to Figure 2, the tire 10 includes a crown 12 comprising a tread 14 intended to come into contact with a ground during rolling and a crown reinforcement 16 extending into the crown 12 in the circumferential direction X. The tire 10 also includes a sealing layer 18 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.

[0102] The top reinforcement 16 includes a working reinforcement 20 and a shrinkage reinforcement 22. The working reinforcement 20 includes at least one working layer and here includes two working layers comprising a radially inner working layer 24 arranged radially inside a radially outer working layer 26.

[0103] The shrink frame 22 includes at least one, here a shrink layer 28.

[0104] The top reinforcement 16 is radially surmounted by the tread 14. Here, the shrinkage reinforcement 22, here the shrinkage layer 28, is arranged radially outside the working reinforcement 20 and is therefore radially intercalated between the working reinforcement 20 and the tread 14.

[0105] The tire 10 comprises two sidewalls 30 extending radially inwards from the apex 12. The tire 10 further comprises two beads 32 radially inwards from the sidewalls 30. Each sidewall 30 connects each bead 32 to the apex 12.

[0106] The tire 10 includes a carcass reinforcement 34 anchored in each bead 32, in this case wound around a bead 33. The carcass reinforcement 34 extends radially in each sidewall 30 and axially in the crown 12, radially inward to the crown reinforcement 16. The crown reinforcement 16 is arranged radially between the tread 14 and the carcass reinforcement 34. The carcass reinforcement 34 includes at least one carcass layer 36.

[0107] With reference to Figure 2, the tire 10 comprises a tread layer 110 and a support layer 112 of the tread layer 110. The support layer 112 is arranged radially inside the tread layer 110 and has very low rolling resistance.

[0108] With reference to figures 2 and 3, each working layer 24, 26, shrinkage layer 28 and carcass layer 36 comprises an elastomeric matrix in which one or more wire reinforcement elements of the corresponding layer are embedded.

[0109] The shrink-fit reinforcement 22, here the shrink-fit layer 28, comprises one or more wire shrink-fit reinforcement elements 280 wound circumferentially helically along a principal direction D0 forming, with the circumferential direction X of the tire 10, an angle AF, in absolute value, less than or equal to 10°, preferably less than or equal to 7° and more preferably less than or equal to 5°. Here, AF=-5°.

[0110] Each radially inner working layer 24 and radially outer layer 26 comprises respectively wire reinforcement elements 240, 260 extending along principal directions D1, D2 forming with the circumferential direction X of the tire 10, angles respectively AT1 and AT2 of opposite orientations and in absolute value, strictly greater than 10°, preferably ranging from 15° to 50° and more preferably ranging from 15° to 30°. Here, AT1=-26° and AT2=+26°.

[0111] The carcass layer 36 comprises carcass wire reinforcement elements 360 extending along a main direction D3 forming with the circumferential direction X of the tire 10, an angle AC, in absolute value, greater than or equal to 60°, preferably ranging from 80° to 90° and here AC=+90°.

[0112] Each wire reinforcement element of the 280 swaging, 240, 260 working and 360 carcass is, for example, identical to those described in applications WO2021250331, WO2022074341 or WO2022069819.

[0113] With reference to Figures 1 and 2, the tread 14 comprises a tread surface 38 through which the tread 14 makes contact with the ground. The tread surface 38 is intended to make contact with the ground when the tire 10 rolls over the ground. The tread surface 38 is axially delimited by first and second axial edges 41, 42 passing through each point N arranged on either side of the median plane M and for which the angle between the tangent T to the tread surface 38 and a line parallel R to the axial direction Y passing through this point is equal to 30°.

[0114] The tread 14 comprises an axially central portion PO and first and second axially lateral portions P1, P2 arranged axially outside the axially central portion PO on either side of the portion axially central PO with respect to the median plane M of the tire 10. Each first and second axially lateral portion P1, P2 has an axial width respectively L1, L2 such that L1=30.3 mm and L2=25.4 mm.

[0115] The tread 14 comprises N>1 main circumferential cutouts, here N main circumferential grooves, comprising first, second, third and fourth main circumferential cutouts respectively designated by references 52, 54, 56, 58. The first and second main circumferential cutouts 52, 54 are arranged axially on either side of the median plane M of the tire 10 and are the axially outermost main circumferential cutouts of the tread 14.

[0116] The first axially lateral portion P1 and the second axially lateral portion P2 are arranged axially outside the first axially external main circumferential cutout 52 and the second axially external main circumferential cutout 54, respectively. The first axially lateral portion P1 extends axially from the first axial edge 41 of the rolling surface 38 to the axially external edge 43 of the first main circumferential cutout 52. The second axially lateral portion P2 extends axially from the second axial edge 42 of the rolling surface 38 to the axially external edge 44 of the second main circumferential cutout 54.

[0117] Each main circumferential cutout 52 to 58 has a depth Hr ranging from 4.0 mm to the carving height Hs, preferably ranging from 5.0 mm to the carving height Hs, and more preferably ranging from 5.5 mm to the carving height Hs. Each depth Hr is greater than or equal to 50% of the carving height Hs. Here, Hs = 6.5 mm, Hr1 = 6.3 mm for each of the first and second main circumferential cutouts axially external 52, 54, and Hr2 = 6.5 mm for each of the main circumferential cutouts 56, 58 of the axially central portion PO. Thus, each main circumferential cutout 52, 54, 56, 58 advantageously has a depth such that Hr1 / Hs > 75%, Hr2 / Hs > 75% and more preferably Hr1 / Hs > 90%, Hr2 / Hs > 90%.

[0118] Each main circumferential cutout 52 to 58 has an axial width Lr1, Lr2, Lr3, Lr4 respectively greater than or equal to 1.0 mm, preferably greater than or equal to 5.0 mm and more preferably ranging from 5.0 mm to 20.0 mm. Here, Lr1=6.6 mm, Lr2=11.7 mm, Lr3=8.8 mm and Lr4=10.0 mm.

[0119] The axially central portion PO comprises central ribs, specifically the first, second, and third central ribs designated by reference numerals 62, 64, and 66, respectively. Each central rib 62, 64, and 66 is arranged axially between two of the main circumferential cutouts adjacent 52 to 58.

[0120] Each central rib 62, 64, 66 includes transverse cutouts 74, 75, 76 having a width equal to 0.4 mm and a depth equal to 3.0 mm.

[0121] Each first and second axially lateral portion P1, P2 comprises respectively a first and second lateral rib designated by reference numerals 68, 70, and here constitutes respectively each first and second lateral rib 68, 70. Each first and second axially lateral portion P1, P2 comprises an axial portion P11, P21 having an axial width equal to 50% of the axial width L1, L2 of each first and second axially lateral portion P1, P2. Each axial portion P11, P21 extends axially outwards from each axially external edge 43, 44 from which each first and second main circumferential axially external cutout 52, 54 extends.

[0122] The tread 14 comprises N transverse cutouts 80, 90 formed partly in at least one of the first and second axially lateral portions P1, P2, and here formed at least partly respectively in each first and second axially lateral portion P1, P2. Here N=87. Thus, the N transverse cutouts 80, 90 form N pairs of circumferentially adjacent transverse cutouts 80 in a circumferential direction S of rotation around the tire 10. Similarly, the tread 14 comprises N, here N=87, triplets of circumferentially adjacent transverse cutouts 80 in the circumferential direction S of rotation around the tire 10. In Figure 2, the bottom of the cutout 80 is represented by a dashed line.

[0123] Each cross-section 80, 90 comprises respectively a thin portion 82, 92 and a wide portion 84, 94.

[0124] Each thin portion 82, 92 comprises an axially internal portion 86, 96 extending into the axial portion P11, P21 of each first and second axially lateral portion P1, P2. Each thin portion 82, 92 also comprises a complementary portion 88, 98 arranged outside the axial portion P11, P21 of each first and second axially lateral portion P1, P2.

[0125] Each wide portion 84, 94 comprises an axially external portion and is here constituted by an axially external portion 84, 94 arranged outside the axial portion P11, P21 of each first and second axially lateral portion P1, P2. Each axially external portion 84, 94 communicates respectively with each axially internal portion 86, 96 and is arranged axially outside respectively of each axially internal portion 86, 96.

[0126] Each axially internal portion 86, 96 is the most axially internal portion inside of each transverse cutout 80, 90. Each axially inside portion 86, 96 opens respectively into each main circumferential cutout 52, 54 which is adjacent to it.

[0127] Each axially outer portion 84, 94 is the outermost axial portion of each transverse cutout 80, 90.

[0128] Each transverse cutout 80, 90 extends along an axial length Loti, Lot2 of the portion of each transverse cutout 80, 90 formed respectively in each first and second axially lateral portion P1, P2. Here, Loti = L1 = 30.3 mm and Lot2 = L2 = 25.4 mm. Each axially internal portion 86, 96 of each transverse cutout 80, 90 extends along an axial length Li1, Li2 equal to at least 20%, preferably at least 35%, and here equal to 50% of the axial length Loti, Lot2 of the portion of each transverse cutout 80, 90 formed in each first and second axially lateral portion. Here, Li1 = 15.2 mm and Li2 = 12.7 mm.

[0129] Each axially internal portion 86, 96 has a width La ranging from 0.2 mm to 2.2 mm, preferably from 0.2 mm to 1.0 mm, more preferably from 0.2 mm to 0.6 mm, and even more preferably from 0.2 mm to 0.5 mm, and here La = 0.4 mm. Each axially internal portion 86, 96 has a depth ranging from 2.0 mm to 5.5 mm, preferably from 3.0 mm to 5.0 mm, and here equal to 4.5 mm.

[0130] Each axially external portion 84, 94 has a width Lb strictly greater than the respective width of each axially internal portion 86, 96. Each width Lb ranges from 0.7 mm to 5.0 mm, preferably from 1.0 mm to 5.0 mm, and more preferably from 2.0 mm to 4.5 mm, and is here equal to 2.3 mm, 2.8 mm, or 3.3 mm, depending on the pattern described below to which the cutout belongs. Each axially external portion 84, 94 has a depth ranging from 2.0 mm to 5.5 mm, and is here equal to 5.1 mm.

[0131] The tire 10 is obtained by molding a raw blank in a mold comprising a plurality of different patterns. In Figure 1, the junctions J between two circumferentially adjacent patterns are represented by solid lines. In this case, the mold comprises three different patterns which have been randomly distributed so as to mold the tread 14. The tread 14 thus comprises three different patterns A, B, C distributed in the circumferential direction of rotation S around the tire as follows: AABACBBCCABCBABAAABBCBAABCCCBAAAABBCBCBAAA BCCCBAAAAAABCBCCCBAAAABCCBABCCCBAAAAAABCBABAB.

[0132] We will now describe only the transverse cutouts 80 formed at least partially in the first axially lateral portion P1. The characteristics of the transverse cutouts 90 formed at least partially in the second portion axially lateral P2 can be deduced mutatis mutandis.

[0133] Each axially internal portion 86 of each transverse cut 80 of each motif A, B, C extends along a mean direction forming a non-zero mean angle with the axial direction Y. In the embodiment presented, the mean angle of the axially internal portion 86 of at least 25%, preferably at least 50%, and more preferably at least 75%, and here 100%, of the transverse cuts 80 is equal to a value taken from a list of first, second, and third values ​​FA, FB, FC. The values ​​of angles FA, FB, and FC are different in pairs. Each axially external portion 84 of each transverse cut 80 extends along a mean direction forming a non-zero mean angle FG with the axial direction Y. The non-zero mean angle FG is substantially the same for each transverse cut 80.

[0134] More specifically, each average angle of the axially internal portion 86 of at least 15%, preferably at least 25% and here 41% of the transverse cuts 80 is equal to the first value FA, each average angle of the axially internal portion 86 of at least 15%, preferably at least 25% and here 32% of the transverse cuts 80 is equal to the second value FB and each average angle of the axially internal portion 86 of at least 15%, preferably at least 25% and here 27% of the transverse cuts 80 is equal to the third value FC.

[0135] The mean angles of the axially internal portions 86 are at least 25%, preferably at least 35% and here 61% of the N pairs of the N circumferentially adjacent transverse cuts 80 different.

[0136] The mean angles of the axially internal portions 86 of at least 15%, preferably at least 20% and here 21% of the N triplets of the N circumferentially adjacent transverse cuts 80 are different in pairs.

[0137] Each non-zero mean angle of each axially interior portion 86, 96 is less than or equal to 50°. Here, FA=5°, FB=25° and FC=45°. The mean angle FG is strictly less than 25°, preferably less than or equal to 20° and more preferably less than or equal to 15° and here equal to 10° regardless of pattern A, B, C.

[0138] The width La of each axially internal portion 86 of each of the N transverse cutouts 80 is here such that 1 < Lamax / La < 4.0, preferably 1 < Lamax / La < 3.2 with Lamax being the maximum value of the widths of the axially internal portions 86 of the transverse cutouts 80. In this case, Lamax=La=0.4 mm.

[0139] The 80 transverse cutouts made in the first axially lateral portion P1 include several pairs of sound dispersion as well as several sound dispersion triplets that we will now describe in detail.

[0140] Figure 1, which illustrates the arrangement of AABACBBCCA patterns, shows several pairs and triplets of sound dispersion. Some pairs and triplets of sound dispersion include 80 non-circumferentially adjacent cross-sections in the S direction of rotation, and other pairs and triplets of sound dispersion include 80 circumferentially adjacent cross-sections in the S direction of rotation.

[0141] With reference to Figure 1, we will first describe the sound dispersion pairs comprising two transverse cuts 80 not circumferentially adjacent in the direction of rotation S and exemplified by the example of the first and second transverse cuts 801, 802 as well as the sound dispersion pairs comprising two transverse cuts 80 circumferentially adjacent in the direction of rotation S and exemplified by the example of the first and second transverse cuts 811, 812.

[0142] Each first and second transverse cutout 801, 802 includes an axially internal portion 861, 862 extending along a mean direction, forming respectively a first non-zero mean angle F1 and a second non-zero mean angle F2 with the axial direction Y. The first mean angle F1 is different from the second mean angle F2. Similarly, each first and second transverse cutout 811, 812 includes an axially internal portion 871, 872 extending along a mean direction, forming respectively a first non-zero mean angle F11 and a second non-zero mean angle F12 with the axial direction Y. The first mean angle F11 is different from the second mean angle F12.

[0143] The first and second mean angles F1, F2 and F11, F12 are equal to values ​​taken from a list of at least first and second different values, here from a list of first, second and third different values ​​two by two made up of the values ​​FA, FB, FC.

[0144] In the illustrated pairs, F1=FA, F2=FC, F11=FC and F12=FB.

[0145] The absolute difference between the first mean angle and the second mean angle of each of the sound dispersion pairs is less than or equal to 40° and greater than or equal to 5°, preferably 10°. Here |F1-F2|=40° and |F11-F12|=20°.

[0146] Regarding sound dispersion pairs comprising first and second circumferentially adjacent transverse cuts in the direction of rotation S, the absolute difference between the first mean angle and the second mean angle of at least 25%, preferably at least 50% and here 57% of the sound dispersion pairs of first and second transverse cuts circumferentially adjacent is less than or equal to 20° and greater than or equal to 5°, preferably 10°. These 57% of sound dispersion pairs include the sound dispersion pair comprising the first and second transverse cutouts 811, 812. Indeed, |F11-F12|=20°.

[0147] With further reference to Figure 1, we will now describe the sound dispersion triplets comprising three transverse cuts 80 not circumferentially adjacent in the direction of rotation S and exemplified by the example of the first, second and third transverse cuts 801, 812, 802 as well as the sound dispersion triplets comprising three transverse cuts 80 circumferentially adjacent in the direction of rotation S and exemplified by the example of the first, second and third transverse cuts 801, 811, 812.

[0148] In the case of the sound dispersion triplet comprising the first, second, and third transverse cutouts 801, 812, 802 not circumferentially adjacent, the first, second, and third mean angles F1, F12, F2 are pairwise different. Similarly, in the case of the sound dispersion triplet comprising the first, second, and third transverse cutouts 801, 811, 812 circumferentially adjacent, the first, second, and third mean angles F1, F11, F12 are pairwise different.

[0149] The first, second and third mean angles F1, F12, F2 and F1, F11, F12 are equal to values ​​taken from a list of at least first, second and third different values, here from a list of first, second and third different values ​​two by two made up of the values ​​FA, FB, FC.

[0150] The absolute difference between the first mean angle and the second mean angle of each sound dispersion triplet, the second mean angle and the third mean angle of each sound dispersion triplet, and the first mean angle and the third mean angle of each sound dispersion triplet is less than or equal to 40° and greater than or equal to 5°, preferably 10°. Here, in the case of the sound dispersion triplet comprising the first, second, and third non-circumferentially adjacent transverse cutouts 801, 812, 802, |F1-F12|=20°, |F12-F2|=20°, and |F1-F2|=40°. In the case of the sound dispersion triplet comprising the first, second and third circumferentially adjacent transverse cutouts 801, 811, 812, |F1-F111=40°, |F11-F12|=20° and |F1-F12|=20°.

[0151] Regarding sound dispersion triplets comprising first, second, and third circumferentially adjacent transverse cutouts in the direction of rotation S, the absolute difference between one of the first, second, and third mean angles and at least one of the other first, second, and third average angles of at least 25%, preferably at least 50% and more preferably at least 75%, and here 100% of the sound dispersion triplets of first, second and third circumferentially adjacent cross cuts is less than or equal to 20° and greater than or equal to 5°, preferably 10°.

[0152] The non-zero mean angle FG of the axially external portion 84, 94 of each transverse cut 80, 90 of each pair or triplet of sound dispersion is strictly less than the mean angle formed by the mean direction of the axially internal portion of at least one of the transverse cuts of each pair or triplet of sound dispersion, here less than the angles F2, F11 and F12.

[0153] Comparative tests

[0154] We compared the tire 10 previously described with a reference tire illustrated in Figure 4 and designated by the reference T. The reference tire T is identical to the tire 10 except for the transverse cuts 80, 90 which are all identical to the cut 812 of the tire 10.

[0155] The external noise generated by tire 10 and control tire T was measured alternately by mounting them on the same vehicle under identical conditions. The vehicle was driven on a track conforming to ISO 10844 and certified by UTAC. A designated measurement area on the track was equipped with Müller-BBM vibro-acoustic recording equipment. The raw noise measurement was corrected for ground temperature as specified in UN regulation R117.

[0156] In an initial test, the noise generated by each tire was measured at different steady speeds of 40 km / h, 50 km / h, 60 km / h, 70 km / h, 80 km / h, and 90 km / h. Figure 5 shows the external noise B, expressed in dB, generated by tire 10 and illustrated by curve 10, and the external noise B, expressed in dB, generated by tire T and illustrated by curve T for different steady speeds V expressed in km / h.

[0157] We observe that at 50km / h and 80km / h, which are the usual speeds for evaluating the noise performance of a passenger car tire representing urban and suburban usage conditions, tire 10 generates at least 1 dB less noise compared to the control tire T, which represents a significant gain in these two usage conditions.

[0158] In a second test, the noise generated by each tire was measured when reaching a speed of 50 km / h under different accelerations. At this speed of 50 km / h, the vehicle's acceleration was also measured. Figure 6 shows... a represented the external noise B, expressed in dB, generated by the tire 10 and illustrated by the curve 10, and the external noise B, expressed in dB, generated by the tire T and illustrated by the curve T for different accelerations A expressed in m / s-2.

[0159] Here again, we observe that, regardless of the acceleration used, tire 10 generates at least 1 dB less noise compared to the control tire T, which represents a significant gain regardless of the acceleration conditions.

[0160] The invention is not limited to the embodiment described above.

[0161] Indeed, embodiments can be considered in which the transverse cutouts formed in one or both of the first and second axially lateral portions do not all belong to pairs or triplets of sound dispersion. Thus, in a variant of the preceding embodiment, in addition to the transverse cutouts 80 and 90, there may be identical transverse cutouts with a width La1, for example, equal to 3.0 mm. These transverse cutouts do not satisfy 1 < La1 / La2 < 3.0 (here La2 = 0.5 mm and La1 > 1.5 mm) and therefore do not belong to the pairs or triplets of sound dispersion.

[0162] In other embodiments, each first, second, and third non-zero mean angle of the axially interior portion of each first, second, and third transverse cut of each pair or triplet of sound dispersion is less than or equal to 50°, preferably 40°, and more preferably ranges from 5° to 40°. For example, FA=8°, FB=27°, and FC=35° could be considered.

[0163] In other embodiments, it may also be envisaged that the tread does not include any sound dispersion triplets and only sound dispersion pairs.

Claims

DEMANDS 1. Passenger vehicle tire (10) comprising a tread (14) intended to come into contact with the ground during rolling of the tire (10) by means of a tread surface (38), the tread (14) comprising: - main circumferential cutouts (52, 54, 56, 58) having a depth (Hr1, Hr2) greater than or equal to 50% of the tread height (Hs) comprising first and second main circumferential axially external cutouts (52, 54) arranged axially on either side of the median plane (M) of the tire (10), the first and second main circumferential axially external cutouts (52, 54) being the outermost main circumferential axial cutouts of the tread (14), - a first axially lateral portion (P1) arranged axially outside the first main axially external circumferential cutout (52) and extending axially from a first axial edge (41) of the rolling surface (38) to an axially external edge (43) of the first main axially external circumferential cutout (52), - a second axially lateral portion (P2) arranged axially outside the second main axially external circumferential cutout (54) and extending axially from a second axial edge (42) of the running surface (38) to an axially external edge (44) of the second main axially external circumferential cutout (54), at least one of the first and second axially lateral portions (P1, P2) comprising an axial portion (P11, P21) having an axial width (Li1, Li2) equal to 50% of the axial width (L1, L2) of said at least one of the first and second axially lateral portions (P1, P2) and extending axially outwards from the axially external edge (43, 44) of said first or second main axially external circumferential cutout (52, 54) from which said at least one of the first and second portions extends axially lateral (P1, P2),characterized in that the tread (14) comprises at least transverse cutouts (80, 90) formed at least in part in at least one of the first and second axially lateral portions (P1, P2), each transverse cutout (80, 90) comprising an axially internal portion (86, 96) extending into the axial portion (P11, P21) of said at least one of the first and second axially lateral portions (P1, P2), the transverse cutouts (80, 90) formed in said at least one of the first and second axially lateral portions (P1, P2) comprising at least one sound dispersion pair comprising a first and a second transverse cutout (801, 802, 811, 812), each axially internal portion (861, 862, 871, 872) of each first and second transverse cutout (801, 802, 811, 812) of the sound dispersion pair having respectively a width La1, La2 such that: 1 < La1 / La2 < 2.5 in the case where La1 > 1.5 mm and La2 > 1.5 mm, 1 < La1 / La2 < 3.0 in the case where La1 > 1.5 mm and La2 < 1.5 mm, 1 < La1 / La2 < 4.0 in the case where La1 < 1.5 mm, each axially internal portion (861, 862, 871, 872) of each first and second transverse cut (801, 802, 811, 812) of the sound dispersion pair or pairs extends along an average direction forming respectively a first and a second non-zero average angle (F1, F2, F11, F12) with the axial direction (Y), the first average angle (F1, F11) of the axially internal portion (861, 871) of the first transverse cut (801, 811) of the sound dispersion pair or pairs is different from the second average angle (F2, F12) of the axially internal portion (862, 872) of the second transverse cut (802, 812) of said sound dispersion pair.

2. Pneumatic (10) according to the preceding claim, wherein each first and second non-zero mean angle (F1, F2, F11, F12) of the axially inner portion (861, 862, 871, 872) of each first and second transverse cut (801, 802, 811, 812) of the or each pair of sound dispersion is less than or equal to 50°, preferably to 40° and more preferably goes from 5° to 40°.

3. Pneumatic (10) according to any one of the preceding claims, wherein the difference in absolute value between the first mean angle (F1, F11) and the second mean angle (F2, F12) of the or each pair of sound dispersion is less than or equal to 40°, preferably 30°.

4. Pneumatic (10) according to any one of the preceding claims, wherein the difference in absolute value between the first mean angle (F1, F11) and the second mean angle (F2, F12) of the or each pair of sound dispersion is greater than or equal to 5°, preferably 10°.

5. Pneumatic (10) according to any one of the preceding claims, wherein the first and second mean angles (F1, F2, F11, F12) are equal to values ​​taken from a list of at least the first and second different values ​​(FA, FB, FC): - the average angle of the axially internal portion (86, 96) of at least 25%, preferably at least 50% and more preferably at least 75% of the transverse cuts (80, 90) of said at least one of the first and second axially lateral portions (P1, P2) is equal to one of at least one of the first and second different values ​​(FA, FB, FC), - Each axially internal portion (86, 96) of each transverse cut (80, 90) whose mean angle is equal to at least one of the first and second different values ​​(FA, FB, FC) has a width La such that: o 1 < Lamax / La < 2.5, preferably 1 < Lamax / La < 2.1 in the case where Lamax > 1.5 mm and La > 1.5 mm, o 1 < Lamax / La < 3.0, preferably 1 < Lamax / La < 2.4 in the case where Lamax > 1.5 mm and La < 1.5 mm, o 1 < Lamax / La < 4.0, preferably 1 < Lamax / La < 3.2 in the case where Lamax < 1.5 mm, with Lamax being the maximum value of the widths of the axially internal portions (86, 96) of at least 25%, preferably at least 50% and more preferably at least 75% of the cross-sections (80, 90) whose mean angle is equal to one of at least the first and second different values ​​(FA, FB, FC).

6. Pneumatic (10) according to the preceding claim, wherein: - each mean angle of the axially internal portion (86, 96) of at least 15%, preferably at least 25% of the transverse cuts (80, 90) of said at least one of the first and second axially lateral portions (P1, P2) is equal to the first value (FA), and - each mean angle of the axially internal portion (86, 96) of at least 15%, preferably at least 25% of the transverse cuts (80, 90) of said at least one of the first and second axially lateral portions (P1, P2) is equal to the second value (FB).

7. Pneumatic (10) according to any one of the preceding claims, wherein the transverse cutouts (80, 90) formed at least in part in said at least one of the first and second axially lateral portions (P1, P2) comprising at least one sound dispersion triplet comprising a first, second and third transverse cutouts (801, 802, 811, 812), each first, second and third transverse cutout (801, 802, 811, 812) of the or each sound dispersion triplet comprising an axially internal portion (861, 862, 871, 872) extending into the axial portion of said at least one of the first and second axially lateral portions (P1, P2), each axially interior portion (861, 862, 871, 872) of each first, second and third transverse cut (801, 802, 811, 812) of the sound dispersion triplet having respectively a width La1 > La2 > La3 such that: 1 < La1 / La3 < 2.5, preferably 1 < La1 / La3 < 2.1 in the case where La1 > 1.5 mm and La3 > 1.5 mm, 1 < La1 / La3 < 3.0, preferably 1 < La1 / La3 < 2.4 in the case where La1 > 1.5 mm and La3 < 1.5 mm, 1 < La1 / La3 < 4.0, preferably 1 < La1 / La3 < 3.2 in the case where La1 < 1.5 mm, each axially internal portion (861, 862, 871, 872) of each first, second, and third transverse cut (801, 802, 811, 812) of the sound dispersion triplet extends along an average direction forming respectively a first, second, and third non-zero mean angle (F1, F2, F11, F12) with the axial direction (Y), the first, second, and third mean angles (F1, F2, F11, F12) of the axially internal portions (861, 862, 871, 872) of the first, second, and third transverse cuts (801, 802, 811, 812) of the sound dispersion triplet Sound dispersion is different in pairs.

8. Pneumatic (10) according to the preceding claim, wherein the first, second and third mean angles (F1, F2, F11, F12) are equal to values ​​taken from a list of at least first, second and third values ​​that are different two by two (FA, FB, FC): - the average angle of the axially internal portion (86, 96) of at least 25%, preferably at least 50% and more preferably at least 75% of the transverse cuts (80, 90) of said at least one of the first and second axially lateral portions (P1, P2) is equal to one of at least first, second and third different values ​​(FA, FB, FC), - Each axially internal portion (86, 96) of each transverse cut (80, 90) whose mean angle is equal to at least one of the first, second, and third different values ​​(FA, FB, FC) has a width La such that: o 1 < Lamax / La < 2.5, preferably 1 < Lamax / La < 2.1 in the case where Lamax > 1.5 mm and La > 1.5 mm, o 1 < Lamax / La < 3.0, preferably 1 < Lamax / La < 2.4 in the case where Lamax > 1.5 mm and La < 1.5 mm, o 1 < Lamax / La < 4.0, preferably 1 < Lamax / La < 3.2 in the case where Lamax < 1.5 mm, with Lamax being the maximum value of the widths of the axially internal portions (86, 96) of at least 25%, preferably at least 50% and more preferably at least 75% of the cross-sections (80, 90) whose mean angle is equal to one of at least the first, second and third different values ​​two by two (FA, FB, FC).

9. Pneumatic (10) according to the preceding claim, wherein: - each mean angle of the axially internal portion (86, 96) of at least 15%, preferably at least 25% of the transverse cuts (80, 90) of said at least one of the first and second axially lateral portions (P1, P2) is equal to the first value (FA), - each mean angle of the axially internal portion (86, 96) of at least 15%, preferably at least 25% of the transverse cuts (80, 90) of said at least one of the first and second axially lateral portions (P1, P2) is equal to the second value (FB), and - each mean angle of the axially internal portion (86, 96) of at least 15%, preferably at least 25% of the transverse cuts (80, 90) of said at least one of the first and second axially lateral portions (P1, P2) is equal to the third value (FC).

10. Pneumatic (10) according to any one of the preceding claims, wherein the first and second transverse cutouts (801 811 , 812) of the or each pair of sound dispersion are circumferentially adjacent.

11. Pneumatic (10) according to claim 10, wherein the difference in absolute value between the first mean angle (F1, F11, F12) and the second mean angle (F1, F11, F12) of the or each pair of sound dispersion of first and second circumferentially adjacent transverse cutouts (801, 811, 812) is less than or equal to 20°.

12. Pneumatic (10) according to claim 10 or 11, wherein the difference in absolute value between the first mean angle (F1, F11, F12) and the second mean angle (F1, F11, F12) of the or each pair of sound dispersion of first and second circumferentially adjacent transverse cutouts (801, 811, 812) is greater than or equal to 5°, preferably 10°.

13. Tire (10) according to any one of the preceding claims, wherein, the tread (14) comprising N circumferentially adjacent transverse cutouts (80, 90) forming N pairs of circumferentially adjacent transverse cutouts (80, 90) in a circumferential direction of rotation (S) around the tire, the width La of each axially inner portion (86, 96) of each of the N circumferentially adjacent transverse cutouts (80, 90) is such that: 1 < Lamax / La < 2.5, preferably 1 < Lamax / La < 2.1 in the case where Lamax > 1.5 mm and La > 1.5 mm, 1 < Lamax / La < 3.0, preferably 1 < Lamax / La < 2.4 in the case where Lamax > 1.5 mm and La < 1.5 mm, 1 < Lamax / La < 4.0, preferably 1 < Lamax / La < 3.2 in the case where Lamax < 1.5 mm, with Lamax being the maximum value of the widths of the axially internal portions (86, 96) of the transverse cuts (80, 90) of the N pairs of circumferentially adjacent transverse cuts (80, 90), the mean angles of the axially internal portions of at least 25%, preferably at least 35% of the N pairs of the N circumferentially adjacent transverse cuts (80, 90) are different.

14. Tire (10) according to any one of the preceding claims, comprising several pairs of sound dispersion, each pair of sound dispersion comprising first and second circumferentially adjacent transverse cutouts (80, 90) in a circumferential direction of rotation (S) around the tire, the difference in absolute value between the first mean angle and the second mean angle of at least 25%, preferably at least 50% and more preferably at least 75% of said pairs of sound dispersion of first and second circumferentially adjacent transverse cutouts (80, 90) is less than or equal to 20°.

15. Tire (10) according to any one of the preceding claims, comprising several pairs of sound dispersion, each pair of sound dispersion comprising first and second circumferentially adjacent transverse cutouts (80, 90) in a circumferential direction of rotation (S) around the tire, the difference in absolute value between the first mean angle and the second mean angle of at least 25%, preferably at least 50% and more preferably at least 75% of said pairs of sound dispersion of first and second circumferentially adjacent transverse cutouts (80, 90) is greater than or equal to 5°, preferably 10°.

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