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BR-112021015370-B1 - PNEUMATIC COMPRISING A TREAD

BR112021015370B1BR 112021015370 B1BR112021015370 B1BR 112021015370B1BR-112021015370-B1

Abstract

PNEUMATIC COMPRISING A TREAD. The invention relates to a pneumatic tire comprising a tread (10) bounded by two edges (12A, 12B), said tread (10) comprising a circumferential groove (14) and a plurality of transverse grooves (20A, 20B). Each transverse groove (20A, 20B) extends from one of the edges (12A, 12B) of the tread (10) to a first end (22) of said transverse groove (20A, 20B). At least one transverse groove (20A) of the plurality of transverse grooves (20A, 20B) comprises a bottom that joins the first end (22) thus forming a first inclined wall (26). The tread (10) comprises a transverse incision (30) disposed between two transverse grooves (20A, 20B), said transverse incision (30) extending from the circumferential groove (14) to a second end (32) of said transverse incision (30). The transverse incision (30) comprises a bottom that joins the second end (32) thus forming a second inclined wall (36), said second inclined wall (36) crossing said first inclined wall (26) in a radial section plane (A-A) and according to a projection of said inclined walls (26, 36) in that radial section plane (A-A).

Inventors

  • Aurelie Joseph
  • Sébastien GUILHEM

Assignees

  • COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN

Dates

Publication Date
20260317
Application Date
20200304
Priority Date
20190304

Claims (11)

  1. 1. A tire comprising a tread (10) delimited by two edges (12A, 12B), said tread (10) comprising a circumferential groove (14) and a plurality of transverse grooves (20A, 20B), each transverse groove (20A, 20B) extending from one of the edges (12A, 12B) of the tread (10) to a first extremity (22) of said transverse groove (20A, 20B), at least one transverse groove (20A) of the plurality of transverse grooves (20A, 20B) having a bottom that joins the first extremity (22) thus forming a first inclined wall (26), said tread (10) comprising a transverse sipe (30) disposed between two transverse grooves (20A, 20B), said transverse sipe (30) extending from the circumferential groove (14) to a second end (32) of said transverse lamella (30), characterized in that said transverse lamella (30) has a bottom that joins the second end (32) thus forming a second inclined wall (36), said second inclined wall (36) crossing said first inclined wall (26) in a radial section plane (A-A) and according to a projection of said inclined walls (26, 36) in that radial section plane (A-A).
  2. 2. Tire according to claim 1, characterized in that the first inclined wall (26) and the second inclined wall (36) intersect at a height H determined relative to a tread surface (10), with 0.2*P < H < 0.8*P, preferably 0.3*P < H < 0.7*P and more preferably 0.4*P < H < 0.6*P, where P is the depth of the circumferential groove.
  3. 3. Pneumatic device according to claim 1 or 2, characterized in that the first inclined wall (26) and the second inclined wall (36) form respectively an angle a1 and an angle a2 with the transverse direction, the angle a1 and the angle a2 being greater than or equal to 20° and less than or equal to 70°.
  4. 4. Pneumatic device according to claim 3, characterized in that angle a1 and/or angle a2 is/are greater than or equal to 30° and less than or equal to 35°.
  5. 5. Pneumatic device according to claim 3 or 4, characterized in that angle a1 is identical to angle a2.
  6. 6. Pneumatic device according to any one of claims 1 to 5, characterized in that said pneumatic device has an intermediate lamella (28) connecting the first inclined wall (26) of the transverse groove to the circumferential groove (14)
  7. 7. Pneumatic device according to claim 6, characterized in that said intermediate lamella (28) has a depth less than or equal to 25% of the depth P of the circumferential groove (14).
  8. 8. Pneumatic tire according to any one of claims 1 to 7, characterized in that the plurality of transverse grooves (20A, 20B) have a width between 3.5 mm and 5.5 mm.
  9. 9. Pneumatic device according to claim 8, characterized in that the plurality of transverse grooves (20A, 20B) comprises at least two types of transverse grooves having two different widths, the difference between these two widths being at least 15%.
  10. 10. Pneumatic device according to any one of claims 1 to 9, characterized in that the transverse lamella (30) has a width between 0.4 mm and 1.2 mm, preferably between 0.6 mm and 0.8 mm.
  11. 11. Pneumatic device according to any one of claims 1 to 10, characterized in that said pneumatic device has at least one contact surface (38) that protrudes from a side wall of the transverse lamella (30).

Description

[0001] The present invention relates to a tire for a motor vehicle, and more especially to a tire whose wear during operation is better controlled. The invention is not limited to a particular type of vehicle and it can be applied to a tire for a motor vehicle belonging to a list of different types of motor vehicles such as a passenger car, a van, a truck, an agricultural vehicle, a civil engineering vehicle or a two-wheeled vehicle, etc. [0002] As is known, a tire intended to equip a motor vehicle comprises a tread. This tread comprises a tread surface and two edges that delimit said tread surface. The tread surface corresponds to the set of points of the tread that come into contact with a pavement when the tire, inflated to its reference pressure and crushed by a reference load, rolls on that pavement. The reference inflation pressure and the reference load are defined in the conditions of use of the tire, conditions specified notably by the E.T.R.T.O. standard. The tread surface comprises voids formed by various grooves, such as circumferential grooves. The circumferential grooves constitute channels intended to evacuate water during driving on a wet pavement. Similarly, the tread may comprise a plurality of transverse grooves that extend respectively in two series of transverse grooves along the two edges of the tread. Transverse grooves also facilitate the evacuation of water over the edges of the tread. It is known from document FR3026347 that each transverse groove is fitted with a bottom which, joining with one end of said transverse groove on the tread surface, forms an inclined wall. This inclined wall is generally arranged in the vicinity of a circumferential groove so as to favor the evacuation of water from the tread to the opposite end of the transverse groove, near an edge of the tread. Two adjacent transverse grooves delimit a block on the tread. This block has a certain rigidity which is a function, notably, of the dimensions of this block and the hardness of the rubber compound that constitutes said block. To improve tire grip, and especially to improve this grip on a wet pavement, it is known that the block is fitted with at least one transverse sipe. This transverse sipe, whose pattern on the tread can be parallel to the transverse grooves, provides a certain flexibility to the block, thus reducing its overall rigidity. However, it was found that the presence of transverse sipes in the blocks was likely to generate uneven tread wear in areas of the tread surface near the edges of said tread. [0003] There is therefore a need to obtain a tire that exhibits greater uniformity in wear. [0004] The present invention aims to correct this drawback. [0005] More specifically, the present invention aims to improve the regularity of the wear pattern of a tire tread whereby the grip on a wet pavement is increased by the presence of transverse sipes near the edges of that tread. [0006] The invention relates to a tire comprising a tread bounded by two edges, the tread comprising a circumferential groove and a plurality of transverse grooves, each transverse groove extending from one edge of the tread to a first extremity of said transverse groove. At least one transverse groove of the plurality of transverse grooves comprises a bottom that joins the first extremity thus forming a first inclined wall. The tread comprises a transverse sipe disposed between two transverse grooves. This transverse sipe extends from the circumferential groove to a second extremity of said transverse sipe. [0007] According to a general characteristic of the pneumatic tire, the transverse lamella comprises a bottom that joins the second end, thus forming a second inclined wall. The second inclined wall intersects the first inclined wall in a plane of section and according to a projection of said inclined walls onto that plane of section. [0008] By “pneumatic” are meant all types of elastic straps subjected to internal pressure or not. [0009] The "tread" of a tire is understood to be a quantity of rubber material delimited by two main surfaces, one of which, called the tread surface, is intended to come into contact with a pavement when the tire is rolling under the tire's usual rolling conditions. "Usual rolling conditions" of the tire are understood to be the conditions of use defined by the E.T.R.T.O. standard. These conditions of use specify the reference inflation pressure and the reference load that correspond to the load capacity of the tire indicated by its load index and speed rating. These conditions of use may also be called "nominal conditions" or "conditions of use". The tread surface is in this case delimited by two edges of the tread beyond which the tire parts are not in contact with the pavement under the tire's usual rolling conditions. The tire thus comprises the tread, two lateral surfaces also called sidewalls, and two intermediate parts located respectively between a sidewall and the tread. These interme