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EP-4739515-A1 - TREAD FOR A VEHICLE TYRE

EP4739515A1EP 4739515 A1EP4739515 A1EP 4739515A1EP-4739515-A1

Abstract

The invention relates to a tread for a vehicle tyre, wherein a profile groove with a radially upper and a radially lower region and with a first and a second groove flank is formed in the tread, wherein in the radially upper region lateral overhangs are formed on the groove flanks such that a groove width in the radially upper region is smaller, at least along parts of a longitudinal extent of the profile groove, than in the radially lower region and wherein the radially lower region is asymmetrical in relation to a radial direction. The radially upper region has a groove width which tapers and widens alternately along the longitudinal extent, wherein, seen in a slice plane perpendicular to the radial direction, the first groove flank, in a first portion along the longitudinal extent of the profile groove in the radially upper region, is convex in the direction of the second groove flank, and the second groove flank, in the radially upper region of the first portion, is concave in the direction of the first groove flank.

Inventors

  • Proksa, Andrej
  • KORBAS, MARIO

Assignees

  • Continental Reifen Deutschland GmbH

Dates

Publication Date
20260513
Application Date
20240624

Claims (15)

  1. 1. Tread for a vehicle tire, wherein a profile groove (1) with a radially upper region (2) and a radially lower region (3) as well as with a first groove flank (4) and a second groove flank (5) is formed in the tread, wherein in the radially upper region (2) of the profile groove (1) lateral overhangs (6) are formed on the groove flanks (4, 5) such that a groove width of the profile groove (1) in the radially upper region (2) is smaller at least along parts of a longitudinal extension of the profile groove (1) than in the radially lower region (3) of the profile groove (1) and wherein, viewed in a sectional area perpendicular to the longitudinal extension, the radially lower region (3) is formed asymmetrically to a radial direction, characterized in that the groove width in the radially upper region (2) alternately narrows and widens again along the longitudinal extent, wherein, viewed in a sectional surface perpendicular to the radial direction, the first groove flank (4) in a first section (7) along the longitudinal extent of the profile groove (1) in the radially upper region (2) is convex in the direction of the second groove flank (5) and the second groove flank (5) in the radially upper region (2) of the first section (7) is concave in the direction of the first groove flank (4).
  2. 2. Tread according to claim 1, characterized in that a groove bottom (11) of the profile groove (1) merges into the first groove flank (4) in a first curved partial region (12) and merges into the second groove flank (5) in a second curved partial region (13), wherein a minimum radius of curvature (14) characterizing the first curved partial region (12) is smaller than a minimum radius of curvature (15) characterizing the second curved partial region (13).
  3. 3. Tread according to claim 2, characterized in that a ratio between the minimum radius of curvature (14) characterizing the first curved partial region (12) and the minimum radius of curvature (15) characterizing the second curved partial region (13) is between 0.3 and 0.7.
  4. 4. Tread according to one of claims 1 to 3, characterized in that the groove flanks (4, 5) have angles of inclination (16, 17) with respect to the radial direction, wherein a minimum inclination angle (16) of the first groove flank (4) in the radially lower region (3) and a minimum inclination angle (17) of the second groove flank (5) in the radially lower region (3) are in a ratio between 1:3 and 1:2.
  5. 5. Tread according to one of claims 1 to 4, characterized in that, viewed in a sectional surface perpendicular to the radial direction, the first groove flank (4) in a second section (8) along the longitudinal extension of the profile groove (1) in the radially upper region (2) is concave in the direction of the second groove flank (5) and the second groove flank (5) in the radially upper region (2) of the second section (8) is convex in the direction of the first groove flank (4).
  6. 6. Tread according to claim 5, characterized in that the first section (7) has a first length along the longitudinal extension of the profile groove (1) and that the second section (8) has a second length along the longitudinal extension of the profile groove (1), the first and the second length being in a ratio of more than 5:4 or less than 4:5 to one another.
  7. 7. Tread according to one of claims 5 or 6, characterized in that the groove width in the radially upper region (2) of the first section (7) is larger than in the radially upper region (2) of the second section (8).
  8. 8. Tread according to claim 7, characterized in that the first and the second portion (7, 8) are connected to each other by a tapering portion (9), wherein the groove width in the radially upper region (2) of the tapering portion (9) decreases from the first portion (7) to the second portion (8).
  9. 9. Tread according to claim 8, characterized in that the first section (7), the tapered section (9) and the second section (8) are supplemented by a widening section (10) to form a quartet of sections (7, 8, 9, 10), wherein several similar quartets are arranged in a row along the longitudinal extent of the profile groove (1), wherein the widening section (10) of a first quartet connects the second section (8) of the first quartet with a first section (7a) of a second quartet and wherein the groove width in the radially upper Region (2) of the widening section (10) increases from the second section (8) of the first quartet to the first section (7a) of the second quartet.
  10. 10. Tread according to claim 9, characterized in that a length of a quartet of sections (7, 8, 9, 10) along the longitudinal extension of the profile groove (1) and a pitch length of a profile formed in the tread are in a ratio of 1:3 to 1:1.
  11. 11. Tread according to one of claims 1 to 10, characterized in that the groove width in the radially lower region (3) is constant along the longitudinal extension of the profile groove (1).
  12. 12. Tread according to one of claims 1 to 11, characterized in that a maximum groove width in the radially lower region (3) is between 5 mm and 15 mm.
  13. 13. Tread according to one of claims 1 to 12, characterized in that the profile groove (1) has a straight line in the radially lower region (3).
  14. 14. Tread according to one of claims 1 to 12, characterized in that, viewed in a sectional surface perpendicular to the radial direction, the first groove flank (4) in the radially lower region (3) of the first section (7) is convex in the direction of the second groove flank (5) and the second groove flank (5) in the radially lower region (3) of the first section (7) is concave in the direction of the first groove flank (4).
  15. 15. Vehicle tire with a tread according to one of claims 1 to 14.

Description

tread for a vehicle tire Description The invention relates to a tread for a vehicle tire, wherein a profile groove with a radially upper region and a radially lower region as well as with a first groove flank and a second groove flank is formed in the tread, wherein in the radially upper region of the profile groove lateral overhangs are formed on the groove flanks such that a groove width of the profile groove in the radially upper region is smaller at least along parts of a longitudinal extension of the profile groove than in the radially lower region of the profile groove and wherein, viewed in a sectional surface perpendicular to the longitudinal extension, the radially lower region is formed asymmetrically to a radial direction. A vehicle tire, in particular a vehicle tire used on a steering axle, can be subjected to greater stress from the direction of an axial outer side than from the direction of an axial center. In this context, an asymmetrical design of a groove cross-section can offer the advantage that a transverse stiffness can be set differently on the two sides of the profile groove. Furthermore, an increased susceptibility to cracking on an axially outward-facing side of the profile groove can be specifically counteracted by a suitable asymmetrical design, in particular of the groove base. Lateral overhangs in the radially upper areas of profile grooves have the advantage that, when a tread is equipped in this way, there is more material on the tread surface when new than without the overhangs, which can lead to better dry grip and slower wear in the radial direction. Another advantage of a smaller groove width in the radially upper area can be that the groove flanks on the lateral overhangs can support each other when the tread is loaded, which can lead to improved rigidity. Because the profile groove has a greater groove width in the radially lower area than in the radially upper area with the lateral overhangs, a good drainage function can be ensured at the same time. DE 102020 212 560 A1 presents a pneumatic vehicle tire with a tread having a profile with a circumferential groove running in the circumferential direction of the pneumatic vehicle tire, wherein a second, radially inner groove section is expanded in the axial direction compared to a first groove section and wherein the cross-sectional area of the second groove section is formed asymmetrically to the radial direction. Profile grooves with lateral overhangs can have the disadvantage that the wet properties deteriorate due to the correspondingly reduced groove openings in the area of the tread. US 2021/0347209 A1 provides a profile with two circumferential grooves to improve the wet properties, with at least one of these grooves being designed as a complex groove with alternating cavities that are open towards the tread and hidden towards the tread. The invention is based on the object of creating a tread for a vehicle tire which has both good rigidity and durability as well as good wet suitability, in particular good wet grip. The stated object is achieved according to the invention in that the groove width in the radially upper region alternately narrows and widens again along the longitudinal extent, wherein, viewed in a sectional surface perpendicular to the radial direction, the first groove flank in a first section along the longitudinal extent of the profile groove in the radially upper region is convex in the direction of the second groove flank and the second groove flank in the radially upper region of the first section is concave in the direction of the first groove flank. By narrowing and widening, a good compromise can be found between rigidity and service life on the one hand and wet properties on the other. The coordinated concave and convex design of the groove flanks can create additional edge length with efficient use of area, which can have a positive effect on wet grip in particular. The invention thus combines in a special way a groove cross-section perpendicular to the longitudinal extension with a cross-section perpendicular to the radial direction in a radially upper area of the profile groove and thus achieves a high level of both the stiffness and durability as well as the wet grip of the tread according to the invention. If the direction designations axial, in the axial direction, radial, in the radial direction and in the circumferential direction are used, these refer to the tread intended for use on a vehicle tire, with the vehicle tire in turn intended for use on a vehicle. The radial direction refers to a direction that is perpendicular to the axis of rotation of the vehicle tire and intersects the axis of rotation. In the radial direction inwards refers to the orientation that faces the axis of rotation in the radial direction. In the radial direction outwards refers to the orientation that faces away from the axis of rotation in the radial direction. The circumferential direction refers to th