Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/28—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers characterised by the belt or breaker dimensions or curvature relative to carcass
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C11/04—Tread patterns in which the raised area of the pattern consists only of continuous circumferential ribs, e.g. zig-zag
  • B60C11/042—Tread patterns in which the raised area of the pattern consists only of continuous circumferential ribs, e.g. zig-zag further characterised by the groove cross-section
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C11/04—Tread patterns in which the raised area of the pattern consists only of continuous circumferential ribs, e.g. zig-zag
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/24—Wear-indicating arrangements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/02—Carcasses
  • B60C9/0292—Carcass ply curvature
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C9/2003—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel characterised by the materials of the belt cords
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C9/22—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C9/22—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre
  • B60C9/2204—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre obtained by circumferentially narrow strip winding
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C2009/2012—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel with particular configuration of the belt cords in the respective belt layers
  • B60C2009/2016—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel with particular configuration of the belt cords in the respective belt layers comprising cords at an angle of 10 to 30 degrees to the circumferential direction
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C2009/2012—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel with particular configuration of the belt cords in the respective belt layers
  • B60C2009/2019—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel with particular configuration of the belt cords in the respective belt layers comprising cords at an angle of 30 to 60 degrees to the circumferential direction
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C9/22—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre
  • B60C2009/2214—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre characterised by the materials of the zero degree ply cords
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C9/22—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre
  • B60C2009/2223—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre with an interrupted zero degree ply, e.g. using two or more portions for the same ply
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C9/22—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre
  • B60C2009/2252—Physical properties or dimension of the zero degree ply cords
  • B60C2009/2276—Tensile strength
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C9/22—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre
  • B60C2009/2252—Physical properties or dimension of the zero degree ply cords
  • B60C2009/228—Elongation of the reinforcements at break point
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/28—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers characterised by the belt or breaker dimensions or curvature relative to carcass
  • B60C2009/283—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers characterised by the belt or breaker dimensions or curvature relative to carcass characterised by belt curvature
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C2011/0337—Tread patterns characterised by particular design features of the pattern
  • B60C2011/0339—Grooves
  • B60C2011/0341—Circumferential grooves
  • B60C2011/0355—Circumferential grooves characterised by depth
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C2200/00—Tyres specially adapted for particular applications
  • B60C2200/06—Tyres specially adapted for particular applications for heavy duty vehicles

Definitions

• the present invention relates to a tire intended to be mounted on a vehicle, and more particularly the crown of such a tire.
• a tire having a geometry of revolution relative to an axis of rotation the geometry of the tire is generally described in a meridian plane containing the axis of rotation of the tire.
• the radial, axial and circumferential directions respectively denote the directions perpendicular to the axis of rotation of the tire, parallel to the axis of rotation of the tire and perpendicular to the meridian plane.
• the median circumferential plane called the equator plane, divides the tire into two substantially symmetrical half-tori, the tire possibly having asymmetries in the tread or in the architecture, linked to manufacturing precision or to dimensioning.
• the expressions “radially inside” and “radially outside” mean respectively “closer to the axis of rotation of the tire, in the radial direction, than” and “further from the axis of rotation of the tire, in the radial direction, that ".
• the expressions “axially inside” and “axially outside” mean respectively “closer to the equatorial plane, in the axial direction, than” and “further from the equatorial plane, in the axial direction, than”.
• a “radial distance” is a distance from the axis of rotation of the tire, and an “axial distance” is a distance from the equatorial plane of the tire.
• a “radial thickness” is measured in the radial direction, and an “axial width” is measured in the axial direction.
• the expression “in line with” means “for each meridian, radially interior substantially within the limit of the axial coordinates delimited by”.
• the points of a working layer in line with a groove designate for each meridian, all the points of the working layer radially inside the groove within the limit of the axial coordinates delimited by the groove.
• the expression “overhanging” means “for each meridian, radially outside substantially within the limit of the axial coordinates delimited by”.
• the central rib overhanging the central corrugation designates for each meridian, the rib of the tread radially. external to the central corrugation, located substantially within the limit of the axial coordinates delimited by the corrugation.
• plumb and overhang indicate that there is a relationship between the axial widths and the axial positions of the two objects that this term connects.
• a tire comprises a crown comprising a tread intended to come into contact with the ground via a tread surface, two beads intended to come into contact with a rim and two sidewalls connecting the crown to the beads.
• a tire comprises a carcass reinforcement comprising at least one carcass layer, radially inner at the crown and connecting the two beads.
• the tread of a tire is delimited, in the axial direction, by two side surfaces.
• the tread is further made up of one or more rubber mixes.
• rubber mixture denotes a rubber composition comprising at least one elastomer and a filler.
• the crown comprises at least one crown reinforcement radially inside the tread.
• the crown reinforcement comprises at least one working reinforcement comprising at least one working layer composed of reinforcing elements parallel to each other forming, with the circumferential direction, an angle of between 15 ° and 50 °.
• the crown reinforcement can also comprise a hooping reinforcement comprising at least one hooping layer comprising reinforcing elements forming, with the circumferential direction, an angle of between 0 ° and 10 °, the hooping reinforcement usually being but not necessarily radially outside the working layers.
• a linear curve per piece For a given meridian, for each layer of crown reinforcement reinforcement elements, working, or other, a linear curve per piece, called radially outer curve (CRE) of said layer, passes through the point more radially outside of each reinforcing element.
• CRE radially outer curve
• a linear surface per piece For a given meridian, for any layer of crown reinforcement, working, or other reinforcing elements, a linear surface per piece, called the radially interior curve (CRI) of said layer, passes through the most radially point inside each reinforcement element.
• the radial distances between a layer of reinforcing elements and any other element of the tire are measured on a meridian section, from one or the other of these curves and so as not to integrate the radial thickness of said layer .
• the radial distance is measured from the radially outer curve CRE at this point; and respectively from the radially internal curve CRI to the other measuring point if the latter is radially internal to the layer of reinforcing elements.
• cutouts are placed in the tread.
• a cutout designates either a well, or a groove, or an incision, or a circumferential groove and forms a space opening onto the rolling surface.
• An incision or a groove has, on the running surface, two main characteristic dimensions: a width W and a length Lo, such that the length Lo is at least equal to 2 times the width W.
• An incision or a groove is therefore delimited by at least two main side faces determining its length Lo and connected by a bottom face, the two main side faces being spaced from each other by a non-zero distance, called the width W of the incision or groove.
• the depth of the cutout is the maximum radial distance between the running surface and the bottom of the cutout. The maximum value of cutout depths is called tread depth D.
• a groove is a substantially circumferential groove, the side faces are substantially circumferential in the sense that their orientation can vary locally around plus or minus 45 ° around the circumferential direction but that all of the patterns belonging to the groove are found all around the tread, forming a substantially continuous assembly, that is to say having discontinuities of less than 10% in length compared to the length of the patterns.
• the circumferential grooves or a circumferential assembly of grooves arranged over the entire circumference of the tire, constitute the circumferential borders of the ribs.
• a rib is an element in substantially circumferential and substantially continuous relief, composed of the patterns of the tread either between an axial edge of the tire and a circumferential border, the most axially outer the closest, or between two circumferential borders.
• the ribs are substantially continuous in the direction or grooves of thickness and / and of width significantly smaller than those of the circumferential grooves, can take place in the rib.
• the rib is substantially circumferential in the insofar as its circumferential borders can have a variation of axial position according to the meridian considered because a circumferential groove can have lateral faces which are circumferentially undulating.
• the width of the rib is the minimum axial distance between two points of the two borders of the rib, regardless of the meridian or meridians to which they belong.
• a tire must meet multiple performance criteria relating to phenomena such as wear, grip on different types of ground, rolling resistance and dynamic behavior. These performance criteria sometimes lead to solutions opposing other criteria. To improve the overall performance compromise, it is possible to undulate the working layers as shown in patent applications EP 35229085A1, EP35229087.
• the reduction in the breaking strength of the reinforcing elements of the tire has the drawback of reducing the resistance to puncture of the crown by certain objects.
• ASTM WK20631 American (ASTM WK20631) and Chinese (GB 9743-2007) regulations based on the measurement of the energy required for an indenter to penetrate through the crown of tires.
• the decrease in puncture resistance resulting from the use of reinforcing elements in a tire with lower breaking strength means that these tires no longer meet these regulations.
• These tires then become unfit for sale in these countries, for import either as spare parts or fitted to vehicles. Compliance with this regulation is therefore an important commercial issue for all manufacturers, whether or not they are in these countries.
• breaking energy tests The breaking energy of the tire under the test conditions imposed by the regulation is therefore called “breaking energy performance”.
• the tests and the associated performance will be named as follows in the remainder of the document. For tires of the same type, i.e. manufactured in the same factory, the same architecture, same tread, the results are scattered by almost 10%.
• the breaking strength of the reinforcing elements of the working layers is considered to be predominant as shown in patent US8662128, via their reinforcement either by increasing the density or by increasing the density. diameter of the elementary wires of the reinforcing elements of the working layers. It is also possible to add a layer of local reinforcement, the reinforcing elements of which form an angle with the longitudinal axis of between 20 and 90 ° (DE102016202295, DE102013107475) between the carcass reinforcement and the working frame.
• these solutions are contrary to the inventors' primary objective, which is to gain mass and raw materials, or gain in performance at iso-mass.
• the main objective of the present invention is therefore to increase the performance in resistance to penetration of a tire without degrading the other performances of the tire.
• a tread intended to come into contact with a ground via a tread surface, a median circumferential plane passing through the center of the tread, the tread surface comprising grooves, the grooves forming a space opening onto the running surface and being delimited by at least two main side faces connected by a bottom face,
• the circumferential borders of the central ribs being substantially circumferential grooves, called circumferential grooves, or a circumferential set of grooves
• a central rib being such that the median circumferential plane passes between its two borders or, if the median circumferential plane passes through a circumferential groove, such that the median circumferential plane passes at a distance from one of the borders of said central rib, at most equal to 15 mm
• the circumferential grooves or the grooves of the circumferential set of grooves forming the borders of the central rib (s) having a width W defined by the distance between two side faces, at least equal to 5 mm and a depth D defined by the maximum radial distance between the running surface and the bottom face, at least equal to 2 mm
• a crown reinforcement radially inside the tread, comprising a working reinforcement, and a carcass reinforcement radially inner to the crown reinforcement comprising at least one carcass layer
• the working reinforcement comprising at least one working layer, each working layer extending radially from a radially inner curve to a radially outer curve, each working layer comprising reinforcing elements, at least partially metallic coated with an elastomeric material, parallel to each other and forming with the circumferential direction of the tire, an angle whose absolute value is at least equal to 15 ° and at most equal to 50 °, the most radially outer working layer comprising at least one central corrugation directly above at least one central rib, of an amplitude at least equal to 1 mm, each central corrugation being such that the portion of the layer working layer of the central corrugation is radially outside the portion of the working layer directly above the bottom faces of the circumferential grooves or the grooves the circumferential set of grooves delimiting the central rib overhanging the central corrugation considered
• At least one local reinforcement comprising at least one layer of reinforcing elements, mutually parallel and forming with the circumferential direction of the tire, an angle whose absolute value is at most equal to 5 °, being at the plumb with at least one central corrugation of the most radially outer working layer.
• the principle of the invention is therefore to create at least one undulation around the equatorial plane, on at least the most radially outer working layer in line with at least one rib of the tread.
• This or these corrugations bring a part of said working layer closer to the tread surface because this part of the corrugation is radially outside the part of said layer in line with the circumferential grooves or the grooves of the circumferential assembly of grooves delimiting said rib which, given its proximity to the equatorial plane, is said to be central.
• the amplitude of the corrugation is at least equal to the diameter of the reinforcing elements of the local reinforcement frame which will be positioned directly above said corrugation. Care should be taken that the most radially outer crown layer is not radially outer to the most radially outer point of the tire wear indicator so that it does not deteriorate at the end of the tire's life by contact with it. floor.
• the crown reinforcement comprises only a single working layer and the invention also works in this case.
• the crown reinforcement can comprise another layer of reinforcing elements such as for example a hooping layer.
• the amplitude of the ripple of a working layer is measured on one or more meridian cuts.
• the amplitude is equal to the radial distance between the most radially exterior point of the working layer considered under the rib considered and the most radially interior point of said layer directly above the bottom face of the circumferential grooves or grooves constituting the circumferential borders of said rib.
• these two points will be of the same nature from the point of view of the geometry of the working layer. They will both be taken either on the neutral fiber, or on the radially internal curve (CRI), or on the radially external curve (CRE) of the working layer considered.
• the amplitude of this corrugation must be at least equal to 1 mm, in order to have significant effects on the scale of the tire.
• the radial distance (do), between the radially outer curve (CRE) of the most radially working layer outer surface and the tread surface is at least 1 mm less than the radial distance (de) between the radially outer curve (CRE) of the most radially outer working layer and the tread surface, distance measured plumb of the bottom face of the circumferential groove or of the grooves constituting the circumferential borders of the rib overhanging said corrugation.
• the breaking energy performance is, among other things, dependent on the mechanical coupling between the layers of the crown reinforcement and the layer or layers of the carcass reinforcement. Indeed, the more the layers of the reinforcements are radially distant from each other, the less the mechanical coupling is important and the lower the perforance in breaking energy. Thus, with an amplitude of at least 1 mm, the mechanical coupling is significantly reduced and the performance in breaking energy significantly altered except to provide, in accordance with the invention, a local reinforcement armature arranged radially between the carcass reinforcement and the most radially outer working layer.
• Such a local reinforcement reinforcement makes it possible, on the one hand, to restore or even increase the performance of the breaking energy test compared to a tire without corrugation and, on the other hand, to create the corrugation by radially separating the tire. radially outermost working layer of the carcass reinforcement layer (s).
• the invention makes it possible to increase the performance in breaking energy of the order of 15%, but without adding any volume of materials, unlike solutions with local reinforcement reinforcements not positioned in corrugations of the layer of most radially outer work or work layers.
• the breaking Energy test is carried out by positioning an indenter on a rib and not in a circumferential groove. Positioning in a circumferential groove would reduce the distance from the indenter to the crown reinforcement and to the carcass reinforcement and would therefore reduce the bending forces exerted on these elements during the test. For this reason the indenter is always positioned on a rib. It is therefore not useful to have a local reinforcement beyond the ribs insofar as the reinforcement elements of the local reinforcement frame are long enough to take up forces in a coupled manner with the reinforcement elements of the others. top layers of reinforcing elements.
• the axial width of a rib would behave the same as a broken part of a layer of reinforcing elements and would not further resist the progression of the indenter.
• the idea is to position them at an angle with the circumferential direction (XX ') of the tire, the absolute value of which is at plus equal to 5 °.
• the breaking energy test does not specify in the case where a circumferential groove passes through the center of the tread on which rib among the two central ribs of this type of tread, position the indenter.
• the two central ribs existing in this arrangement can be defined as a rib such that the median circumferential plane passes at a distance from one of the borders of said central rib at most equal to 15 mm.
• the reinforcing elements of the local reinforcement or reinforcements are long enough to be further coupled to the other reinforcing elements of the crown or carcass reinforcement layers between which they are placed.
• the reinforcing elements of the local reinforcement frame may be continuous son or bands of son placed circumferentially.
• the invention reduces the dispersion of the breaking energy test by at least 25% and therefore allows better control of the performance.
• each central corrugation of the most radially outer working layer is at least equal to 1.5 mm preferably at least equal to 2 mm, and at most equal to 5 mm, preferably at most equal to 3 mm.
• a preferred solution is to position the local reinforcement between the carcass reinforcement and the most radially inner working layer. It is therefore preferred that the local reinforcement reinforcement be radially outside the carcass reinforcement radially inside the most radially internal working layer.
• the most radially outer working layer to include a central corrugation directly above each central rib, each central corrugation being overhanging a reinforcement local reinforcement.
• the axial width of each local reinforcement frame is at least equal to 5 mm, and at most equal to the axial width of the central rib overhanging said local reinforcement frame.
• each local reinforcement frame (6) comprises a layer of reinforcing elements, mutually parallel and forming with the circumferential direction (XX ') of the tire, an oriented angle of which the absolute value is at most equal to 0.5 °, preferably at most equal to 0.2 °, preferably equal to 0 °.
• the local reinforcement frame consists of a continuous reinforcing element placed circumferentially individually or as a strip of several reinforcing elements. In the case of laying a single reinforcing element, the different turns of said reinforcing elements constitute reinforcing elements parallel to each other.
• each local reinforcement reinforcement reinforcement is made of textile, preferably of the aliphatic polyamide, aromatic polyamide, combination of aliphatic polyamide and aromatic polyamide, polyethylene terephthalate or rayon, parallel to each other, each of these materials having different interests in this context of resistance and elongation at break among other criteria.
• the reinforcing elements of the local reinforcement frame have a radial thickness at most equal to 1.5 mm.
• the breaking force of the reinforcing elements of each local reinforcement is at least equal to 20 daN, at most equal to 120 daN and their elongation at break Acc is at least equal to 6%, preferably at most equal to 30%, measured according to standard ASTM D885 / D885M -10A of 2014.
• each corrugation of the most radially outer working layer overhangs at most one local reinforcement, each local reinforcement being produced by the '' continuous winding of a strip of at least two elements of reinforcement, to generate at most 3 layers of reinforcing elements.
• the multiple thicknesses can be obtained by successive winding of one or more strips but also by curling which involves an overlap of a strip between two laying turns.
• the axial distance between two contiguous reinforcing elements of the local reinforcement reinforcement is at least equal to 0.2mm and at most equal to 0.4 mm to maintain optimal performance in breaking energy.
• One of the advantages of the invention is that, compared to the state of the art where the addition of a local reinforcement is done without coupling it with the ribs of the tread, the reinforcing elements of the carcass layer (s) have a meridian curvature of constant sign directly above the narrowest working layer of the crown reinforcement. This avoids local buckling of the carcass reinforcement layer (s) and therefore preserves its endurance.
• the invention requires some adjustments during manufacture.
• the addition of a local reinforcement whose angle is close to 0 ° under a rib will disturb, depending on the laying tension, the flattening of said rib and therefore risk generating irregular wear of the axial edges of the rib. the rib.
• This problem can be solved by adjusting the laying tension of the reinforcing elements of the local reinforcement reinforcement.
• the radial distance (d1) between the radially outer curve (CRE) of the most radially outside and the bottom face of the circumferential grooves is at least equal to 1 mm and at most equal to 5 mm, preferably at least equal to 2 mm and at most equal to 4 mm. Below lower limits, the tire could be too sensitive to damage. Beyond the upper limits, the rolling resistance of the tire would be penalized.
• the amplitude of the corrugation is at least equal to 1 mm but limited to 5 mm due to the radii of curvature to be imposed on the metallic working layers, which are rigid and therefore not very deformable.
• the tread comprises, for example in a groove or a circumferential groove of the tread, at least one wear indicator, and that the minimum radial distance (du) between the radially outer curve (CRE) of the most radially outer layer of the crown reinforcement and the tread surface is at least equal to the radial distance (df) between the tread surface and the most radially outer point of the wear indicator.
• CRE radially outer curve
• df radial distance
• the minimum radial distance (du) between the radially outer curve (CRE) of the most radially outer layer of the crown reinforcement and the running surface is at most equal to the depth D of the most circumferential groove. close increased by 2 mm and at least equal to the depth D of the nearest circumferential groove reduced by 2 mm.
• This solution allows a ideal positioning of the most radially outer layer of reinforcement elements of the crown reinforcement and the tread surface.
• the minimum radial distance (du) between the radially outer curve (CRE) of the most radially outer layer of the crown reinforcement and the tread surface is necessarily measured on the radially outer portion of the crown reinforcement, therefore at level of a ripple.
• the depth D of a major groove or of a circumferential groove is at least equal to 6 mm, and at most equal to 20 mm.
• the tread depths between 6 and 10 mm allow a good compromise between the performance in wear and in rolling resistance in many touring tires.
• the tread depths between 10 and 20 mm are interesting for the same compromises in tires for vehicles carrying heavy loads.
• the invention is not limited to tires of particular use.
• the reinforcing elements of said layer are made of textile, preferably of the aliphatic polyamide, aromatic polyamide, combination of aliphatic polyamide and of aromatic polyamide, polyethylene terephthalate or rayon, mutually parallel and forming, with the circumferential direction (XX ') of the tire, an angle B at most equal to 10 ° in absolute value.
• the crown reinforcement consists of 2 working layers having opposite angles and a hoop layer, like many current crown reinforcements.
• Figure 1 shows a meridian section of the crown of a tire according to the invention with a corrugation (412) directly above the central rib (251) where the circumferential median plane (P) passes. It illustrates the local reinforcement layer (6) positioned under the corrugation (412) of the radially outermost working layer (41) and the different radial distances do, du, de and df.
• Figure 2 shows a meridian section of the crown of a tire according to the invention with a corrugation (412) and a local reinforcement layer (6) directly above each central rib (251), on both sides. other from circumferential groove through which passes the circumferential median plane (P). It also illustrates the distances W, D and d1.
• Figure 3 shows a meridian section of the crown of a tire according to the invention with a corrugation (412) and two local reinforcement layers (61, 62) directly above each central rib (251), respectively under each working layer (41, 42) on either side of the circumferential groove through which the circumferential median plane (P) passes.
• Figures 4 and 5 show tread patterns of a tread and in particular a circumferential set of grooves (24 ’) forming one of the circumferential boundaries (252) of the central rib (251).
• FIG. 1 schematically shows the meridian section of the crown of the tire 10 according to the invention.
• Each meridian plane is associated with a Cartesian coordinate system (XX ’, YY’, ZZ ’).
• the tire 10 comprises a tread 2 intended to come into contact with a ground via a tread surface 21.
• In the tread are arranged circumferential grooves and grooves 24 defining ribs 25 whose central rib 251 through which passes the median circumferential plane P.
• the tire 10 comprises at least one wear indicator 7.
• the tire 10 further comprises a crown reinforcement 3 comprising a working reinforcement 4 and here for the example, a hooping frame 5.
• the working frame comprises at least one working layer and here for the example two working layers 41 and 42 each comprising mutually parallel reinforcing elements.
• the crown reinforcement 3 is radially outside a carcass reinforcement 8.
• FIG. 1 also shows, directly above this central rib 251, a corrugation 412 of the most radially outer working layer 41 and directly above this. corrugation a local reinforcement layer 6. In this variant, only the most radially outer working layer 41 is corrugated.
• Figure 2 shows a variant of the invention with a corrugation 412 and a local reinforcement layer 6 directly above each central rib 251, on either side of the circumferential groove where passes the circumferential median plane P
• the figure shows the grooves each having side faces 241 and 242 and a bottom face 243 and a width W, maximum axial distance between the side faces, possibly different from one groove 24 to another.
• only the most radially outer working layer 41 is corrugated.
• Figure 3 shows a variant of the invention similar to that of Figure 2 with 2 central ribs 251 but, in this variant, the two working layers 41 and 42 are corrugated, and under each corrugation is positioned a layer local reinforcement.
• Figures 1, 2, 3 represent the following radial distances:
• a meridian section of the tire is obtained by cutting the tire along two meridian planes. This or these cuts are used to determine the different radial distances.
• Figures 4 and 5 show treads where a rib 251 is delimited on one side by a circumferential groove 24 and on the other side by a circumferential set of grooves 24 '.
• Figure 4 shows a circumferential set of grooves 24 'for which the circumferential border 252 of the central rib is evident.
• FIG. 5 represents a circumferential assembly of grooves 24 'for which the axial position of the grooves of said assembly varies.
• the border 252 of the central rib is not only substantially axial.
• said border is extrapolated passing through the points of said border 252 closest to the center of the central rib through a circumferential plane.
• the invention was carried out on a tire A of dimension 295 / 35R20 intended to be fitted to a passenger vehicle.
• the depths D of the grooves in the tread are between 4 and 7 mm and equal to 7 mm for the circumferential grooves, for variable widths W for the grooves and equal to 15 mm for the grooves.
• the crown reinforcement is composed of two working layers whose reinforcing elements make an angle of + or - 38 ° with the circumferential direction and of a hooping layer whose reinforcing elements make an angle of + or - 3 ° with the circumferential direction.
• the most radially outer working layer is corrugated under the central rib of the tread.
• the amplitude of the ripple under the midrib is 1.2mm.
• the axial width of the corrugation is equal to 21 mm.
• the radial distance d1 between the radially outer curve CRE of the most radially outer working layer 41 and the bottom face 243 of the circumferential grooves 25 is between 2 mm and 3.5 mm.
• the gain in rolling resistance was evaluated on a standard machine for standardized measurements ISO 2850: 2009. The tests show a gain of more than 2% compared to the reference tire B.
• a measurement of the characteristic Dz of the tire behavior model shows an increase in this characteristic for a pressure at 2.6 bars hot from 2 to 3%.
• the gain in dry ground grip varies between 0 and 1% depending on the stress conditions.
• the performance gain in breaking energy of tire A compared to tire B is 15% without any increase in mass.

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• 2020
  • 2020-10-22 JP JP2022523444A patent/JP7642631B2/ja active Active
  • 2020-10-22 US US17/771,084 patent/US12109856B2/en active Active
  • 2020-10-22 CN CN202080073028.1A patent/CN114616108B/zh active Active
  • 2020-10-22 WO PCT/FR2020/051905 patent/WO2021079066A1/fr not_active Ceased
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