Search

CN-116635253-B - Tire tread and tire with improved three-level sipe

CN116635253BCN 116635253 BCN116635253 BCN 116635253BCN-116635253-B

Abstract

The present invention relates to a tread for a tire. In particular, it refers to a tread featuring a three-level tread geometry optimized so as to ensure long-term high performance on wet and/or snow surfaces, while maintaining handling characteristics and braking ability on dry and/or slippery surfaces in the case of new tires.

Inventors

  • G. Rodrix
  • P. Agorati
  • TIRONE ANTONIO

Assignees

  • 普利司通欧洲有限公司

Dates

Publication Date
20260505
Application Date
20211215
Priority Date
20201218

Claims (6)

  1. 1. Tread (10) for a tire (1), having a plurality of tread components (20), each having a respective contact surface (21), wherein at least one tread component (20) of the plurality of tread components (20) comprises a sipe (100) defining a first opposing face (101) and a second opposing face (102) of the at least one tread component (20), the sipe (100) having a sipe depth (P) along a radial direction (U), wherein the sipe depth (P) comprises a first section (A) and a second section (C), and the first opposing face (101) and the second opposing face (102) have respective complementary profiles (101 a, 101C, 101z, 102a, 102C, 102 z) along the first section (A) and the second section (C), wherein the first opposing face (101) and the second opposing face (102) also have respective interference profiles (101B) with each other coupling the first section (A) and the second section (C), wherein each of the first interference profile (101B) and the second interference profile (102B) comprises at least two contact surfaces (11 'a, 11' ', 12' B, 12'', B) facing each other and configured to reversibly contact each other in response to a load acting on the at least one tread component (20), wherein the first interference profile (101B) and the second interference profile (102B) are spaced apart between a minimum depth (P min ) and a maximum depth (P max ) of the intermediate section (B) in a manner defining a deformation region (V) of the at least one tread component (20) that develops along a development axis (V) parallel to the radial direction (U), characterized in that the development axis (V) is an axis of symmetry with respect to the development of the first interference profile (101B) and the second interference profile (102B), Wherein each interference profile (101 b, 102 b) comprises three pairs of contact surfaces (1 a, 1b, 1c, 2a, 2b, 2 c), wherein the first interference profile (101 b) and/or the second interference profile (102 b) provides a different maximum distance from the development axis (v) at each pair of the three pairs of contact surfaces (1 a, 1b, 1c, 2a, 2b, 2 c), Wherein the maximum distance increases along the radial direction (U).
  2. 2. Tread (10) according to claim 1, wherein the mutual distance between the first interference profile (101 b) and the second interference profile (102 b) at the minimum depth (P min ) is smaller than the mutual distance at the maximum depth (P max ).
  3. 3. Tread (10) according to any of the preceding claims, wherein said at least two contact surfaces (11 'a, 11 "a, 12' b, 12" b) are continuous and collide with each other to form a recess (C 1 、C 2 ) at the maximum distance of the respective interference profile (101 b, 102 b) with respect to the development axis (v).
  4. 4. Tread (10) according to claim 1 or 2, wherein the sipe depth (P) comprises, in order, the first section (a), the intermediate section (B) and the second section (C).
  5. 5. A tread (10) according to claim 3, wherein the sipe depth (P) comprises, in order, the first section (a), the intermediate section (B) and the second section (C).
  6. 6. Tyre (1) comprising a tread (10) according to any of the preceding claims.

Description

Tire tread and tire with improved three-level sipe Technical Field The present invention relates to a tire tread. In particular, the present invention relates to a tread pattern incorporating an enhanced three-level sipe geometry that improves the performance of a new tire on a dry surface while maintaining high performance on wet and/or snow surfaces throughout its useful life. Background Tires are typically provided with a tread having laterally and/or circumferentially extending grooves, thereby defining "tread elements" that engage the ground and contribute to the overall performance of the tire. It is known that the presence of grooves (called incisions or sipes), which are generally thin and not too wide, defines voids that enable to improve the grip and traction of the tyre, in particular in wet and/or snow conditions, thus facilitating drainage in wet conditions and snow capture in snow conditions. The ability of tires to maintain their initial performance level for as long as possible, especially in wet and/or snow-covered conditions, and in view of the physiological wear and ageing of the materials constituting the tire, has heretofore been the subject of particular attention of operators of the industry. In fact, normal tread wear generally results in a rapid decrease in void fraction and, closer to the end of its useful life, the more the tire is subjected to a significant decrease in adhesion in wet/snowy regions. To counter this trend, it is known to manufacture tires comprising sipes with a specific profile, the main purpose of which is to modify the geometric characteristics of the tread and to compensate for the performance degradation due to the reduction of the void fraction during wear. In this sense, it is known to model the sipe in such a way as to define inside the tread pattern a suitable so-called "hidden" void surplus, in order to mitigate the void fraction reduction during tyre wear and thus the performance degradation on wet and/or snowy surfaces. The above known solutions, while trying to maintain good performance in terms of grip and traction on wet and/or snow surfaces during the service life of the tyre, on the other hand cause a reduction in the rigidity of the tread and therefore an overall deterioration in terms of rigidity, braking capacity and handling on dry and/or slippery surfaces (particularly when the tyre is new). For example, US 2012/132337A1 discloses a sipe composed of continuous thick and thin sections, alternately arranged and inclined with respect to the sliding surface of the tread. US 2002/017349A1 discloses a sipe characterized by an overall zig-zag configuration to prevent deformation of the block and to increase its stiffness. EP 2138330A1 discloses a sipe having opposite faces configured to cooperate between them and whose distance is at a maximum in the region of the tread subject to the maximum deflection. Disclosure of Invention The technical problem addressed and solved by the present invention is therefore to overcome the above-mentioned problems and in particular to provide a tread with sipe geometry such that the performance on wet and/or snow surfaces as a result of normal wear during the lifetime of the tire is improved without affecting the braking and handling ability of the tire (when the tire is new) on dry and/or slippery surfaces. This is achieved by means of a tire tread as defined in claim 1. Another object of the invention is a tire as defined in claim 7. Further features of the invention are defined in the respective dependent claims. The tread according to the invention provides the best performance in wet and/or snow-covered road conditions, but at the same time provides the increased stiffness required in the case of dry road surfaces. In other words, the tread of the present invention provides a sipe having an optimized geometry that not only compensates for the reduction in void volume due to tire wear, but also at the same time facilitates as much as possible the handling and braking ability on dry and/or slippery surfaces, thereby improving performance in the context of new tires. For the purposes of the present invention, the term "tread element" refers to a portion of the tread pattern that may be identically repeated along the entire length of the tread. The term "tread component" or simply "component" refers to any block of the tread, regardless of its shape and/or positioning. The term "contact surface" refers to the portion of the component surface that contacts the ground during rolling of the tire. The term "sipe" refers to a thin and generally narrow groove in a tread component, obtained by means of the moulding of a tire, and is specifically intended to improve the performance of the tire on wet and/or snow surfaces. Other advantages, as well as features and uses of the present invention will become apparent from the following detailed description of a preferred embodiment of the invention, given by way of non-limitin