CN-122003330-A - Tire with a tire body

Abstract

A tyre (1) comprises a tread band (2) in a radially external position, on which a tread surface (3) is defined. The aforementioned tread band (2) comprises a plurality of grooves (7A, 7B), each groove comprising a first wall (71) and a second wall (72) facing each other and defining a groove Width (WG). At least one of the first wall (71) and the second wall (72) comprises a plurality of protrusions (8) protruding from at least one of the first wall (71) and the second wall (72) having a protrusion Width (WP), wherein the protrusion Width (WP) is less than 20% of the groove Width (WG).

Inventors

• C. R. E. Rawiza
• D.E. Speziari

Assignees

• 倍耐力轮胎股份公司

Dates

Publication Date

20260508

Application Date

20240926

Priority Date

20231010

Claims (19)

1. 1. A tyre (1) comprising a tread band (2) in a radially external position, said tread band (2) defining a tread surface (3) thereon, The tread band (2) comprises: A plurality of grooves (7A, 7B), each groove comprising a first wall (71) and a second wall (72) facing each other and defining a groove Width (WG), Wherein at least one of the first wall (71) and the second wall (72) of a lateral groove (7B) of the plurality of grooves (7A, 7B) comprises a plurality of protrusions (8) protruding from the at least one of the first wall (71) and the second wall (72) by a protrusion Width (WP), Wherein the protrusion Width (WP) is less than 20% of the groove Width (WG).
2. 2. Tyre (1) according to the preceding claim, wherein said groove Width (WG) is between 2mm and 10 mm.
3. 3. Tyre (1) according to at least one of the preceding claims, characterized in that said plurality of grooves (7 a,7 b) have respective bases (9) located between said first wall (71) and said second wall (72) in a radially internal position and respective groove Depths (DG) from said tread surface (3) to said bases (9).
4. 4. Tyre (1) according to the preceding claim, wherein said plurality of projections (8) have respective projection heights (DP) in a radial direction, said projection heights being comprised between 5% and 20% of said groove Depth (DG).
5. 5. A tyre (1) according to claim 3, wherein said plurality of projections (8) are provided in a portion of said at least one of said first wall (71) and said second wall (72), said portion having a height (H) comprised between 20% and 50% of said groove Depth (DG).
6. 6. Tyre (1) according to the preceding claim, wherein said portion of said at least one of said first wall (71) and said second wall (72) is positioned between a minimum height (Qmin) between 10% and 30% of said groove Depth (DG) and a maximum height (Qmax) between 40% and 70% of said groove Depth (DG).
7. 7. Tyre (1) according to at least one of the preceding claims, wherein at least some of said plurality of projections (8) are provided at respective heights different from each other of said at least one of said first wall (71) and said second wall (72).
8. 8. Tyre (1) according to at least one of the preceding claims, wherein at least some of said plurality of protrusions (8) are arranged along at least one line (L) substantially parallel to said tread surface (3).
9. 9. Tyre (1) according to at least one of the preceding claims, wherein at least some of said plurality of protrusions (8) are arranged along a plurality of Lines (LN) substantially parallel to said tread surface (3).
10. 10. Tyre (1) according to the preceding claim, wherein said plurality of Lines (LN) comprises two to four lines.
11. 11. Tyre (1) according to at least one of claims 9 to 10, wherein the protrusions arranged along a first line (L1) of said plurality of Lines (LN) are arranged in a staggered manner with respect to the protrusions (8) arranged along another line (L2) of said plurality of Lines (LN).
12. 12. Tyre (1) according to at least one of the preceding claims, wherein each of said plurality of projections (8) extends a determined projection Length (LP) and two projections of said plurality of projections (8) are spaced apart by a Projection Distance (PD).
13. 13. Tyre (1) according to the preceding claim, wherein said Projection Distance (PD) is substantially equal to said projection Length (LP).
14. 14. Tyre (1) according to at least one of claims 12 to 13, wherein said projection Length (LP) is between 0.5% and 10% of the groove length of said plurality of grooves (7 a,7 b).
15. 15. Tyre (1) according to at least one of claims 12 to 14, characterized in that the ratio of the projection Length (LP) to the projection Width (WP) is between 3 and 20.
16. 16. Tyre (1) according to at least one of claims 12 to 15, characterized in that the ratio of the projection Length (LP) to the projection height (DP) is between 5 and 10.
17. 17. Tyre (1) according to at least one of the preceding claims, wherein each groove of said plurality of grooves (7 a,7 b) has a relative void volume and said plurality of protrusions (8) in each groove has a total protrusion volume comprised between 0.5% and 8% of said void volume, preferably between 0.5% and 4% of said void volume.
18. 18. Tyre (1) according to at least one of the preceding claims, wherein the protrusions of said plurality of protrusions (8) have an elongated shape, a hemispherical shape or alternatively an elliptical shape or a substantially polyhedral shape, preferably a substantially cuboid shape.
19. 19. Tyre (1) according to at least one of the preceding claims, wherein the projections of said plurality of projections (8) are provided on both said first wall (71) and said second wall (72).

Description

Tire with a tire body Technical Field The present invention relates to a tire. More particularly, the present invention relates to a winter tyre or a full season tyre with improved performance, in particular on snow surfaces. Background A tyre generally comprises a carcass structure toroidal-shaped about a rotation axis, on which a belt structure is applied in a radially external position and on which a tread band made of elastomeric material is also superimposed, on which a tread surface intended for contact with the road surface is defined. On the tread band, a plurality of circumferential grooves and/or transverse grooves are generally defined, these grooves defining a corresponding plurality of blocks, which together define the tread pattern of the tire. The characteristics of the tread band, in particular the number and arrangement of grooves provided on the tread surface, mainly determine the performance of the tire in terms of road behaviour, in particular with respect to the possible different conditions of the road surface itself. The term "equatorial plane" of a tire refers to a mid-plane perpendicular to the axis of rotation of the tire. The terms "radial" and "axial" and the expressions "radially internal/external" and "axially internal/external" are used with reference to the rotation axis of the tyre, while the terms "circumferential" and "circumferentially" are used with reference to the annular stretch direction of the tyre, i.e. to the rolling direction of the tyre, which corresponds to a direction lying on a plane coincident with or parallel to the equatorial plane of the tyre. In particular: The expression "radial direction" is used to indicate a direction substantially perpendicular to the rotation axis of the tyre. The term "groove" refers to a depression made on the tread surface, having at least a portion with a width between the walls defining it of at least 1.5mm, referred to as the "groove width". Preferably, the trench has a depth of at least about 5mm, referred to as the "trench depth". The width of the aforementioned groove is such that the walls delimiting the groove do not contact each other under normal driving conditions. This establishes a drainage channel on the tread surface, improving the grip of the tire during running on wet road surfaces. The term "void volume" refers to the volume of tread removed to form the groove itself. In other words, this void volume of the groove is the volume between the two walls and the base of the groove. The term "protrusion" refers to a portion of at least one wall of the groove that protrudes toward the interior of the groove. The term "protrusion width" refers to the dimension of a protrusion measured in a direction orthogonal to the direction in which the protrusion extends. In other words, the protrusion width is a measure of the portion of the wall protruding towards the interior of the groove. The term "protrusion length" refers to the dimension of the protrusion measured in a direction parallel to the direction in which the protrusion extends inside the groove. The term "protrusion height" refers to the dimension of a protrusion measured along its radial extension. The term "protrusion volume" refers to the volume that each protrusion occupies inside the corresponding groove. The term "total protrusion volume" refers to the sum of the volumes of the individual protrusions within the same trench. Patent document JP2006137231a describes a tire having a projection with a projection width of greater than or equal to 60% of the groove width. Patent document US2011290393A1 describes a tyre comprising a tread band having a plurality of raised elements with a contact surface and sidewalls, wherein at least one raised element comprises at least one cut open onto two of the aforementioned sidewalls, said at least one cut being delimited by a first wall and a second wall comprising a protuberance. The first wall comprises at least one protrusion and the second wall comprises as many pairs of first and second protrusions as there are protrusions on the first wall, wherein each protrusion on the first wall is designed to cooperate by contact with a pair of first and second protrusions on an opposing second wall. However, the inventors have noted that these solutions for narrow incisions are not suitable for wider grooves, since the protrusions protrude very much inside the groove, tend to clog the groove, reducing its cross section and preventing water from draining through it. Disclosure of Invention The present inventors have solved the problem of improving the performance of a tire on snow surfaces by promoting the capture and adhesion of snow in grooves engraved in the tread band, without even risking compromising the performance on dry or wet surfaces. The inventors have realized that this object can be achieved by arranging a plurality of protrusions corresponding to the walls of the grooves, the function of the protrusions being to hind