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EP-4741177-A1 - VEHICLE TIRE AND TREAD

EP4741177A1EP 4741177 A1EP4741177 A1EP 4741177A1EP-4741177-A1

Abstract

Tread (1) for a vehicle tire (2), wherein the tread (1) has a negative profile (3) and a positive profile (4), wherein the positive profile (4) is bounded in a radial direction (R) on the outside by a base surface (5) of the tread (1), wherein the positive profile (4) is delimited at least sectionally by a flank surface (6) from the negative profile (3), wherein a transition surface (8) is formed between the flank surface (6) and the base surface (5), wherein the transition surface (8) adjoins the base surface (5) along an edge contour (9). Radially below the transition surface (8) an imaginary flank contour (10) runs at a constant radial height on the flank surface (6), wherein the edge contour (9) at a first axial position (11) encloses an angle (18) with an axial direction (A) that is larger by a first angular difference than the flank contour (10).

Inventors

  • PORUBSKY, Daniel
  • Meier, Nico
  • Eikermann, Wilke
  • Forascepi, Alejandro
  • Henneberger, Ben
  • Rathe, Benjamin
  • Foltin, Miroslav

Assignees

  • Continental Reifen Deutschland GmbH

Dates

Publication Date
20260513
Application Date
20251006

Claims (15)

  1. Tread (1) for a vehicle tire (2), wherein the tread (1) has a negative profile (3) and a positive profile (4), wherein the positive profile (4) is bounded in a radial direction (R) on the outside by a base surface (5) of the tread (1), wherein the positive profile (4) is delimited at least sectionally by a sidewall surface (6) from the negative profile (3), wherein a transition surface (8) is formed between the sidewall surface (6) and the base surface (5), wherein the transition surface (8) adjoins the base surface (5) along an edge contour (9), characterized by that radially below the transition surface (8) an imaginary flank contour (10) runs at a constant radial height on the flank surface (6), wherein the edge contour (9) at a first axial position (11) encloses an angle (18) with an axial direction (A) that is larger by a first angular difference than the flank contour (10).
  2. Running strip (1) according to one of claims 1, characterized in that the edge contour (9) at a second axial position (12) encloses an angle (20) with the axial direction (A) of the same magnitude as the flank contour (10), wherein the edge contour (9) at the second axial position (12) runs along a boundary between the transition surface (8) and the base surface (5) or between the flank surface (8) and the base surface (5).
  3. Tread (1) according to claim 2, characterized in that the first axial position (11) is further away from a tire equator than the second position (12).
  4. Running strip (1) according to one of claims 1 to 3, characterized in that the edge contour (9) at a third axial position (13) encloses an angle (22) with the axial direction (A) that is larger by a third angular difference than the flank contour (10), where the third angle difference is greater than the first angle difference.
  5. Tread (1) according to claim 4, characterized in that the third axial position (13) is further away from a tire equator than the first axial position (11).
  6. Running strip (1) according to one of claims 1 to 5, characterized in that the flank surface (6) adjoins the transition surface (8) at a boundary line (14), wherein the boundary line (14) runs at least sectionally at a variable radial height.
  7. Running strip (1) according to claim 6, characterized in that the boundary line (14) at a lowest point (15) at a radial height in a range between 50% and 90% of a radial distance between a base of the profile negative (3) and the base surface (5) runs above the base of the profile negative (3) and/or that the boundary line (14) at a highest point (16) at a radial height in a range between 80% and 100% of the radial distance between the base of the profile negative (3) and the base surface (5) runs above the base of the profile negative (3).
  8. Running strip (1) according to one of claims 6 or 7, characterized in that the edge contour (9) at a further axial position (17) encloses an angle with the axial direction (A) by a further angular difference larger than the flank contour (10), wherein the further angular difference is larger than the first angular difference, wherein the boundary line (14) at the first axial position (11) runs at a greater radial height than at the further axial position (17).
  9. Running strip (1) according to one of claims 1 to 8, characterized in that the flank surface (6) borders the transition surface (8) at least sectionally at a constant radial height along a boundary line (14).
  10. Running strip (1) according to claim 9, characterized in that the boundary line (14) runs at least sectionally at a constant radial height in a range between 70% and 95% of a radial distance between a base of the profile negative (3) and the base surface (5) above the base of the profile negative (3).
  11. Running strip (1) according to one of claims 9 or 10, characterized in that the flank contour (10) runs at least sectionally along the boundary line (14) on the flank surface (6).
  12. Running strip (1) according to one of claims 1 to 11, characterized in that the edge contour (9) is at least partially straight and/or that the flank contour (10) is at least partially straight.
  13. Tread (1) according to one of claims 1 to 12, characterized in that the edge contour (9) and/or the sidewall contour (10) are intersected by a tire equator and run symmetrically to the tire equator.
  14. Tread (1) according to one of claims 1 to 13, characterized in that four circumferential grooves (24) are formed in the tread (1) and/or that a directional profile is formed in the tread (1).
  15. Vehicle tire (2) comprising a tread (1) according to any one of claims 1 to 14.

Description

The invention relates to a tread for a vehicle tire, wherein the tread has a negative profile and a positive profile, wherein the positive profile is bounded in a radial direction on the outside by a base surface of the tread, wherein the positive profile is delimited at least section by a flank surface from the negative profile, wherein a transition surface is formed between the flank surface and the base surface, wherein the transition surface adjoins the base surface along an edge contour. It is generally known to create transition surfaces between the sidewalls and the base surface of a tire tread. A typical example of a transition surface is a chamfer. Chamfers can be used, for example, to improve the braking performance of a vehicle tire. Regardless of whether chamfers or other details are incorporated into the tread, increasingly stringent requirements are being placed on vehicle tires with regard to noise generation. Edges in the tread profile that enter the tire contact patch contribute to noise generation. Furthermore, the stiffness of the tread plays a role in the extent to which mechanical excitations from the tread surface are transmitted to a radially deeper structure, such as the belt reinforcement and carcass of the vehicle tire. Generally, higher edge angles relative to an axial direction or to the outline of the tire contact patch are conducive to lower noise generation. However, such a tread profile design often results in a higher negative profile ratio and/or reduced stiffness of the tread blocks. Given these relationships, finding a suitable compromise regarding the noise behavior of the tread is difficult, especially since any modification to the The negative aspect of the profile can also influence other target parameters, such as rolling resistance and/or the drainage behavior of the tread. The invention is based on the objective of creating a running strip or a vehicle tire with optimized noise behavior without negatively influencing other target parameters. The problem is solved according to the invention by having an imaginary flank contour run radially below the transition surface at a constant radial height on the flank surface, wherein the edge contour at a first axial position encloses an angle with an axial direction that is larger by a first angular difference than the flank contour. The invention recognizes that the tread profile can be designed differently at various radial heights and finds a way to utilize this to a dual advantage for noise reduction: First, the angle of the edge contour at the point of entry into the tire contact patch can be optimized. Second, block stiffness can be maintained at a high level by a suitable sidewall contour, or, alternatively, an unnecessarily large material loss at the sidewall of the tread block can be avoided by using a sidewall contour angle that differs from that of the edge contour. As a positive side effect, the resulting block stiffness can also lead to improved rolling resistance. Where the terms axial, radial, and circumferential are used in this text, they refer to the tread or tire as intended on a vehicle tire and its rolling motion. In this context, radial refers to a direction perpendicular to and intersecting the axis of rotation of the vehicle tire. Radially inward refers to the orientation facing radially toward the axis of rotation. Radially outward refers to the orientation that points away from the axis of rotation in the radial direction. The circumferential direction describes the direction of rolling motion around the axis of rotation. A tire positioned at the front in the circumferential direction will reach a minimum distance to the road surface earlier during a 180° rotation of the tire when the vehicle is traveling forward than a tire positioned at the rear in the circumferential direction. The axial direction refers to a direction parallel to the axis of rotation. Pointing axially inward refers to an orientation that is axially aligned with a tire equator, a tire equator plane, or a tire equator line. The tire equator plane is a plane perpendicular to the tire's axis of rotation that passes through the center of the tire's axial width, with the tire equator line lying in the tire equator plane and on the tire's surface. The lateral direction is a direction consisting of components of the radial and/or axial directions. In particular, the circumferential and transverse directions can run along a base surface of the tread. The base surface coincides with the smooth surface that the tread would have if no small-scale profile elements, such as grooves or snow edges, were provided. Small-scale profile elements are characterized in at least one of the three dimensions—radial, axial, and circumferential—by a dimension and/or a radius of curvature that is less than or equal to the maximum tread depth in the vehicle tire. Specifically, the base surface remains physically intact wherever no such profile elements are