Michelin Recherche Et Technique S.a.

Compagnie Generale Des Etablissements Michelin

Compagnie Generale Des Establissements Michelin

Societe Detechnologie Michelin

Nicolas Dautrey

Nanae Shimanaka

Salvatore Pagano

Ludovic Greverie

Gael Roty

Yasuhiko Futamura

Yuji Kanno

A tread for a pneumatic tire in which air column resonance sound is reduced and wear of the groove fences and tread portion are caused to be approximately the same, while drainage performance is maintained, wherein a plurality of groove fences are formed and are installed within at least one circumferential groove, extending from the bottom of the circumferential groove, and block at least 70% of the cross-sectional area of the circumferential groove, and the bending parameter of the groove fences, defined as E&#xb7;I/(h3l) (where E is the modulus at 10% elongation of the material used for the groove fences, I is the second moment of area of the groove fence, h is the height of the groove fence, and l is the width of the groove fence) is at least equal to 250 Pa and at most equal to 350 Pa.

Pneumatic tire tread

A pneumatic tire tread capable of mitigating air column resonance and maintaining drainage performance while ensuring that the flexible fences are abraded to a similar extent to the tread portion is formed from a rubber composition and has a tread portion, in which is formed at least one primary groove of depth D and width W having a base surface and two opposing walls, and multiple flexible fences of thickness E, which extend inside the primary groove such that at least 70% of the cross-sectional area of the primary groove is blocked and which are disposed at intervals such that at least one of the multiple flexible fences is in the primary groove in the tread contact patch when the tire is rolling, wherein the multiple flexible fences are formed from at least a rubber composition for fences that is different from the rubber composition for the tread portion; and the rubber composition for fences has an abrasion index that is more than or equal to twice the abrasion index of the rubber composition of the tread portion.

A pneumatic tire tread capable of mitigating air column resonance and maintaining drainage performance while ensuring that the flexible fences are abraded to a similar extent to the tread portion is formed from a rubber composition, and has a tread portion in which a primary groove is formed and multiple flexible fences is formed in the primary groove; the flexible fences are formed from at least a rubber composition for fences that is different from the rubber composition for the tread portion; the rubber composition for fences of the flexible fences has an abrasion index that is more than or equal to twice the abrasion index of the rubber composition of the tread portion; and the rubber composition for fences comprises a filler composition that is based on (a) a diene elastomer, (b) a reinforcing filler selected from the group consisting of carbon black, inorganic fillers, organic fillers, and mixtures of said fillers, which has a BET specific surface area of less than 100 m/g and is in an amount of between 20 phr and 120 phr, preferably between 30 phr and 100 phr; (c) a plasticizing system selected from the group consisting of liquid plasticizer, hydrocarbon resins and mixtures thereof; and (d) a vulcanizing agent.

A pneumatic tire tread capable of mitigating air column resonance and maintaining drainage performance while ensuring that the flexible fences are abraded to a similar extent to the tread portion is formed from a rubber composition, and has a tread portion in which a primary groove is formed and multiple flexible fences is formed in the primary groove; the flexible fences are formed from at least a rubber composition for fences that is different from the rubber composition for the tread portion; the rubber composition for fences of the flexible fences has an abrasion index that is more than or equal to twice the abrasion index of the rubber composition of the tread portion; and the rubber composition for fences comprises a filler composition that is based on (a) a diene elastomer, (b) a filler A, which is more than 50 phr of filler A in which the filler particles are nanoparticles having an average grain size (by weight average) smaller than 500 nm; and (c) a filler B, which is more than 50 phr of filler B in which the filler particles are microparticles having a median grain size (by weight average) larger than 1 &#x3bc;m.

A pneumatic tire tread capable of mitigating air column resonance and maintaining drainage performance while ensuring that the flexible fences are abraded to a similar extent to the tread portion is formed from a rubber composition, and has a tread portion in which at least one primary groove is formed and multiple flexible fences is formed in the primary groove; the flexible fences are formed from at least a rubber composition for fences that is different from the rubber composition for the tread portion; the rubber composition for fences of the flexible fences has an abrasion index that is more than or equal to twice the abrasion index of the rubber composition of the tread portion; and the rubber composition for fences comprises a filler composition that is based on (a) a diene elastomer, (b) a reinforcing filler which is less than 50 phr; (c) a plasticizing system, and (d) a vulcanizing system.

Tire having a tread comprising at least two grooves of generally circumferential orientation, a plurality of transverse grooves (), each transverse groove culminating in openings into two circumferential grooves, the circumferential and transverse grooves having appropriate cross sections for allowing, when running, a flow of liquid present on the road surface, a plurality of closing devices located in these grooves, each closing device closing at least partly the cross section of a groove, each closing device delimiting, with one end of a transverse groove, a length of groove LR of between half and three-quarters of the length of circumferential groove in contact, the length measured under nominal conditions of load and pressure, this tire being characterized in that each closing device is designed to flex and open the section of groove in which it is placed, under the action of a flow of liquid so as to allow the said liquid to flow when running on a water-covered road surface.

Sound supressing device for a tire tread

Tire including a crown, sidewalls extending the crown on each side, these sidewalls being connected to beads intended to be in contact with a mounting rim on which the tire is mounted, this tire having an internal wall delimiting, with the mounting rim, an internal cavity to allow the tire to be inflated. This tire includes, over at least part of its internal wall delimiting the internal cavity, a plurality of protrusions of elongate shape forming a dense coating, this tire being characterized in that these protrusions of elongate shape include a plurality of supporting fibers and a plurality of branching fibers, the branching fibers being attached to the supporting fibers, each supporting fiber having two ends, of which at least one is attached to the internal wall of the tire.

Device inside a tire for reducing rolling noise

Pneumatic tire tread which reduces tread pattern noise while suppressing air column resonance from circumferential grooves is provided with a number of sets of resonators and at least two types of branch groove shapes; the length of the first branch grooves at least 40% of the length of the contact surface, and groove width between 10% and 25% of the circumferential groove width; the length of the second branch grooves between 40% and 90% of the length of the first branch grooves, and the groove width no less than the first branch groove width; first openings and second openings alternately present on same circumferential groove; length between openings in first branch grooves is no more than 50% of the length of the contact surface; difference between the minimum cross-sectional void ratio in the ribs where the branch grooves are provided and the maximum cross-sectional void ratio is no greater than 10%.

A tire comprising a hooping reinforcement, wherein the axial distance between neighboring portions of the hooping reinforcement is greater than or equal to 0.7 mm and smaller than or equal to 2 mm, with the exception of one first axial region Land two second axial regions L. The axial distance of each of the axial ends of the first axial region Lfrom the median plane is greater than or equal to 0.05&#xb7;S and smaller than or equal to 0.15&#xb7;S, S being the maximum axial width of the tire. The two regions Lare provided on both sides of the median plane, each second axial region being centered at an axial distance Dfrom the median plane, Dbeing greater than or equal to 0.25&#xb7;S and smaller than or equal to 0.4&#xb7;S. Each second axial region Lhas an axial width Wthat is greater than or equal to 0.1&#xb7;S. The sum of the axial widths of the first and second axial regions is smaller than or equal to 0.5&#xb7;S. The difference between the average axial distance between neighboring portions of the hooping reinforcement in the first and second axial regions Land L, and the distance outside the first and second axial regions Land Lis at least 0.2 mm.

Tire having a belt ply with cords disposed along the circumference of the tire to reduce the tire noise

Process for molding and vulcanizing a tire, in which a tire blank is placed in a curing press including a mold intended to form the outer shape of the tire, and a pressing member for transmitting the molding pressure and the heat needed to vulcanize the internal portion of the tire blank. A removable elastic membrane, which includes perforations passing completely therethrough, is interposed, during the molding and the vulcanizing step, between the inner surface of the tire and the pressing member, so as to form, by the constituent material of the internal wall of the tire flowing into the perforations, noise-attenuating protuberances distributed over the internal surface of the tire.

Growing community of inventors

Tokyo, Japan

Nicolas Dautrey