Tread for a vehicle tyre
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- CONTINENTAL REIFEN DEUTSCHLAND GMBH
- Filing Date
- 2024-06-24
- Publication Date
- 2026-05-13
AI Technical Summary
Vehicle tire treads face challenges in achieving a balance between stiffness, service life, and wet grip, with existing designs often compromising on one aspect at the expense of others, and are particularly susceptible to cracks and poor wet performance due to asymmetrical stress distribution and groove configurations.
The tread features a profile groove with varying groove widths and asymmetrical cross-sections, where the radially upper region has a narrowing and widening groove width along its length, with convex and concave designs of the groove flanks, respectively, to enhance stiffness, service life, and wet grip by optimizing the use of tread area and stress distribution.
This design achieves a high level of stiffness, service life, and wet grip by efficiently using tread area, reducing susceptibility to cracks, and improving drainage, while maintaining rigidity and dry grip performance.
Smart Images
Figure DE2024200059_09012025_PF_FP_ABST
Abstract
Description
[0001] Tread for a vehicle tire
[0002] Description
[0003] The invention relates to a tread for a vehicle tire, wherein a profile groove is formed in the tread with a radially upper region and a radially lower region and with a first groove flank and a second groove flank, 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 than in the radially lower region of the profile groove at least along parts of a longitudinal extent of the profile groove and wherein, viewed in a sectional area perpendicular to the longitudinal extent, the radially lower region is formed asymmetrically to a radial direction.
[0004] A vehicle tire, particularly one used on a steering axle, can be subjected to greater stress from the axial outer side than from the axial center. In this context, an asymmetrical groove cross-section design can offer the advantage of allowing different transverse stiffness settings on each side of the tread groove. Furthermore, increased crack susceptibility on an axially outward-facing side of the tread groove can be specifically counteracted by a suitable asymmetrical design, particularly of the groove base.
[0005] Lateral overhangs in the radially upper areas of tread grooves have the advantage that, when new, there is more material on the tread surface than without the overhangs. This can lead to better dry grip and slower radial wear. A further advantage of a narrower groove width in the radially upper area can be that the groove flanks can support each other at the lateral overhangs when the tread is loaded, which can lead to improved rigidity. The fact that the tread groove has a wider groove width in the radially lower area than in the radially upper area with the lateral overhangs can simultaneously ensure good drainage.DE 102020 212 560 A1 presents a pneumatic vehicle tire with a tread having a profile and a circumferential groove extending in the circumferential direction of the pneumatic vehicle tire, wherein a second, radially inner groove section is widened 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.
[0006] Tread grooves with lateral overhangs can have the disadvantage of deteriorating wet properties due to the correspondingly reduced groove openings in the tread area. To improve wet properties, US 2021 / 0347209 A1 proposes a tread with two circumferential grooves, with at least one of these grooves being designed as a complex groove with alternating cavities open toward the tread and concealed toward the tread.
[0007] The invention is based on the object of creating a tread for a vehicle tire which has both good rigidity and service life as well as good wet suitability, in particular good wet grip.
[0008] 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 area 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.
[0009] By narrowing and widening the grooves, a good compromise can be found between stiffness and durability on the one hand, and wet properties on the other. The coordinated concave and convex design of the groove flanks allows for additional edge length to be created with efficient surface utilization, which can have a particularly positive effect on wet grip. 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 region of the tread groove, thus achieving a high level of both stiffness and durability as well as wet grip of the tread according to the invention.
[0010] Where 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 as intended on a vehicle tire, with the vehicle tire in turn properly attached to a vehicle. The radial direction refers to a direction perpendicular to the rotation axis of the vehicle tire and intersecting the rotation axis. In the radial direction inward refers to the orientation that faces the rotation axis in the radial direction. In the radial direction outward refers to the orientation that faces away from the rotation axis in the radial direction. The circumferential direction refers to the direction of rolling movement around the rotation axis.When the vehicle is moving forward, a position at the front in the circumferential direction on the vehicle tire passes through a minimum distance from the road surface earlier than a position at the rear in the circumferential direction during a 180° rotation of the vehicle tire. The axial direction refers to a direction parallel to the axis of rotation. Pointing axially inward refers to an orientation that is axially facing a tire equatorial plane or a tire equatorial line. The tire equatorial plane is a plane perpendicular to the axis of rotation of the vehicle tire that runs through the center of the axial width of the vehicle tire, with the tire equatorial line running in the tire equatorial plane and on the surface of the vehicle tire. The transverse direction is a direction that consists of components of the radial direction and / or the axial direction.
[0011] In particular, the circumferential direction and the transverse direction can run on a base surface of the vehicle tire. The base surface coincides with the smooth surface that the vehicle tire would have if no small-scale tread elements, such as grooves or radially protruding ribs, were provided. Small-scale tread elements are characterized in at least one of the three dimensions: radial direction, axial direction, and circumferential direction, by a dimension and / or by a radius of curvature that is less than or equal to a maximum tread depth in the vehicle tire. Specifically, the base surface remains physically intact wherever no such tread elements are provided. The retained sections of the base surface can be at least partially intended for contact with a road surface.Where, for example, a groove runs through a tread of a vehicle tire, the base surface continues as an imaginary surface above the groove; where, for example, a radially projecting rib is arranged on the tread, the base surface continues as an imaginary surface below the radially projecting rib.
[0012] All described features relate in particular to a new condition of the tread. The effects achieved with the features of the main claim can be supported and further enhanced by preferred embodiments and configurations.
[0013] A convex formation of the lateral overhang on the first groove flank in the direction of the second groove flank can be given if, in the first section along the longitudinal extent of the profile groove, the lateral overhang is limited exclusively by a first pair of flank segments enclosing a first angle and / or a first curved flank segment, wherein the first angle assumes a value of more than 180°, or wherein the first curved flank segment is convexly curved in the direction of the second groove flank.Analogously, a concave formation of the lateral overhang on the second groove flank in the direction of the first groove flank exists, for example, when, in the first section along the longitudinal direction of the profile groove, the lateral overhang is limited exclusively by a second pair of flank segments enclosing a second angle and / or a second curved flank segment, wherein the second angle assumes a value of less than 180°, or wherein the second curved flank segment is concavely curved in the direction of the first groove flank. Here, the first and second angles are measured in a surface perpendicular to the radial direction and are open in the direction of the respective opposite groove flank, wherein the axes of curvature of the first and second curved flank segments run parallel to the radial direction.
[0014] The lateral overhangs in the first section can be complementarily convex or concave. This is the case, for example, when the first and second angles add up to 360° and are centered around a common direction, and / or when the first and second curved flank segments are concentric circular arcs.
[0015] The tread groove is preferably a circumferential groove, i.e., a groove that extends over the entire circumference of a vehicle tire equipped with the tread and opens into itself. The circumferential groove may deviate locally from the circumferential direction and, for example, run in a zigzag pattern.
[0016] Preferably, the cross-section in the radially lower region has no kinks, but can be described throughout by well-defined tangents. Furthermore, all curves in the cross-section can be described with radii of curvature of more than 3 mm. A transition to the radially upper region need not be affected by this, but can have bevels and / or curves that can be described by a radius of curvature of less than 3 mm.
[0017] The radially lower region of the tread groove can be formed asymmetrically to the radial direction in various ways. The tread groove can comprise a groove base, wherein the groove base in the radially lower region of the tread groove can transition into the first groove flank in a first curved partial region and can transition into the second groove flank in a second curved partial region. In this case, a minimum radius of curvature characterizing the first curved partial region is preferably smaller than a minimum radius of curvature characterizing the second curved partial region. If the curved partial regions are circular arcs, each curved partial region is characterized by only one radius of curvature, which then serves as the minimum radius of curvature. Preferably, the second groove flank points axially outwards and the first groove flank in the direction of the tire equator.A smaller curvature on the axial outer side and the associated lower susceptibility to cracking allow for greater stress on this side of the tread to be accommodated. In a preferred embodiment, the ratio between the minimum radius of curvature characterizing the first curved partial region and the minimum radius of curvature characterizing the second curved partial region is between 0.3 and 0.7, and preferably between 0.45 and 0.55. The groove base can run straight between the curved partial regions. In a preferred embodiment, however, the groove base between the two curved partial regions is also curved at the transition to the groove flanks. A minimum radius of curvature characterizing the groove base can have a ratio of 2 to 3, preferably 2.4 to 2.6, to the radius of curvature characterizing the second curved partial region.In one embodiment, the first curved partial region, the second curved partial region and the groove bottom can each be described by a circular arc, wherein the circular arcs merge tangentially into one another and wherein the radially deepest point of the profile groove is located at the point of contact between the first curved partial region and the groove bottom.
[0018] The entire radially lower region of the profile groove can be continuously curved in the cross-section perpendicular to the longitudinal extent. Alternatively, a straight section of a respective groove flank can adjoin radially above the first curved section and / or radially above the second curved section within the radially lower region. In particular, the transition between the first curved section and a straight section of the first groove flank can occur radially further down than the transition between the second curved section and a straight section of the second groove flank.In one embodiment, in the radially lower region of the profile groove, there is a transition from the first curved partial region into the straight partial region of the first groove flank, but not from the second curved partial region into a straight partial region of the second groove flank; in other words, the second curved section can extend in the cross-section of the radially lower region of the profile groove perpendicular to the longitudinal direction up to the transition into the radially upper region, without a straight partial region of the second groove flank being arranged in the radially lower region.
[0019] The groove flanks preferably have angles of inclination relative to the radial direction. The angle of inclination of a groove flank can also be determined locally as the angle of inclination of a tangent to a curved portion. Angles of inclination of the groove flanks are positive if they open radially upward and away from the respective opposite groove flank, so that a V-shaped groove, for example, would have two groove flanks inclined at positive angles. The angles of inclination of the groove flanks in the radially lower region are preferably consistently positive.If the second groove flank points axially outwards and the first groove flank points in the direction of the tire equator, the transverse stiffness in the axially outer direction can be increased compared to the axially inner direction by selecting a minimum angle of inclination of the second groove flank in the radially lower region that is greater than the minimum angle of inclination of the first groove flank in the radially lower region. In this way, a greater load on the tread from the axial outside can be specifically counteracted. The minimum angle of inclination of a groove flank in the radially lower region is preferably present in the region of a rectilinear partial region of the groove flank and / or can be present at a radially upper end of the radially lower region. The ratio of the minimum angle of inclination of the first groove flank in the radially lower region to the minimum angle of inclination of the second groove flank in the radially lower region can be between 1:3 and 1:2.The minimum inclination angle of the first groove flank in the radially lower region can be between 4° and 8°.
[0020] The boundary between the radially upper zone and the radially lower zone can be defined at the radial level of a radially lower end of the lateral overhangs and / or where the groove width starts to decrease from maximum tread depth and looking towards the base surface.
[0021] Between the lateral overhangs in the radially upper region and the radially lower region, chamfered transitions can be formed on the groove flanks. If the groove width in the region of the radial extension of the chamfered transitions is smaller than in positions further radially down in the radially lower region, the chamfered transitions can be assigned to the radially upper region. The chamfered transitions can have angles of inclination relative to the radial direction in a cross-section perpendicular to the longitudinal extension of the tread groove, with the angles of inclination being open radially upwards and towards the respective opposite groove flank, so that the chamfered transitions roof over the radially lower region. An angle of inclination can be between 50° and 70°, measured in the middle of a radial extension or a width extension of a chamfered transition.Radially above the beveled transitions, the lateral overhangs can be designed to create a radial region of constant groove width. In particular, the groove flanks on the lateral overhangs in the radial region of constant groove width can run parallel to the radial direction. The radial extension ratio of the radial region of constant groove width in the radially upper region can be between 0.1 and 0.5.
[0022] Chamfers can be formed on the lateral overhangs on the groove flanks in the radially upper region as transitions to the base surface of the tread. The chamfers can include angles of inclination with the radial direction, with the angles of inclination opening radially outward and away from the respective opposite groove flank, so that the groove width increases radially outward in the radial extension area of the chamfers. An angle of inclination can be between 20° and 40°, measured at the center of a radial extension or a width extension of a chamfer.
[0023] Transitions between the radially lower region of the profile groove, the bevelled transitions, the radial region of constant groove width and / or the chamfers in the radially upper region of the profile groove are preferably each rounded, so that preferably the entire cross-section of the profile groove can be described by well-defined tangents in a sectional area perpendicular to the longitudinal extent.
[0024] Preferably, the first groove flank, viewed in a sectional plane perpendicular to the radial direction, can be concave in a second section along the longitudinal extent of the profile groove in the radially upper region toward the second groove flank, and the second groove flank can be convex in the radially upper region of the second section toward the first groove flank. In other words, the first and second sections can be oppositely complementary to one another, so that the two sections along the longitudinal extent of the profile groove can be combined to form an S-shaped or zigzag-shaped profile.
[0025] Alternatively, the second section can be formed with straight flanks in the direction of the longitudinal extent. The groove width in the radially upper region of the first section can be greater than in the radially upper region of the second section. In particular, a profile which narrows and widens again in the radially upper region according to the invention can be composed of sections in the manner of the first and second sections along the longitudinal extent of the profile groove. A ratio between the groove width in the radially upper region of the first section and the groove width in the radially upper region of the second section can be between 2:1 and 10:1, preferably between 4:1 and 6:1. The groove width in the radially upper region of the first section can be between 10 mm and 25 mm.
[0026] The first section along the longitudinal extent of the profile groove can have a first length, and the second section along the longitudinal extent of the profile groove can have a second length. In one embodiment, the first and second lengths can be equal to one another. In an alternative embodiment, the first and second lengths can be in a ratio of more than 5:4 or less than 4:5. If the groove widths differ in the first and second sections, such an unequal length ratio can be used to specifically adjust a negative portion in the tread.
[0027] The first and second sections can be connected to each other along their longitudinal extent by a tapered section, wherein the groove width in the radially upper region of the tapered section decreases from the first section to the second section. In this way, a continuous transition between different groove widths in two adjacent first and second sections can be realized.The first section, the tapered section, and the second section can be supplemented by a widening section to form a quartet of sections, wherein several similar quartets are arranged in a row along the longitudinal extent of the tread groove, wherein the widening section of a first quartet connects the second section of the first quartet to a first section of a second quartet, and wherein the groove width increases in the radially upper region of the widening section from the second section of the first quartet to the first section of the second quartet. The lengths of the similar quartets along the longitudinal extent of the tread groove can be identical or vary within the scope of a known variation of a pitch length of a profile formed in the tread.A length of a quartet of sections and a pitch length of a profile formed in the tread may preferably be in a ratio of 1:3 to 1:1.
[0028] A groove width in the radially lower region can be constant along the longitudinal extent of the tread groove or at least exhibit a smaller variation than the groove width in the radially upper region. A maximum groove width in the radially lower region can preferably be between 5 mm and 15 mm. A groove width that is essentially constant along the longitudinal extent of the tread groove can ensure an efficient drainage function in the radially lower region.
[0029] Two alternative, each advantageous, designs are worthy of note for the shape of the profile groove along its longitudinal extension in the radially lower region: According to a first alternative, the profile groove can have a straight line in the radially lower region. In this case, the profile groove can take on an S-shaped or zigzag line in the radially upper region with two mutually complementary sections along its longitudinal extension, while in the radially lower region it can run straight. In this way, a particularly long edge length can be provided in the radially upper region for good wet grip, while simple and efficient drainage can be enabled in the radially lower region.According to a second alternative, the first groove flank, viewed in a sectional area perpendicular to the radial direction, is convex in the radially lower region of the first section in the direction of the second groove flank, and the second groove flank is concave in the radially lower region of the first section in the direction of the first groove flank. Alternatively or additionally, the first groove flank, viewed in a sectional area perpendicular to the radial direction, can be concave in the radially lower region of the second section in the direction of the second groove flank, and the second groove flank can be convex in the radially lower region of the second section in the direction of the first groove flank. In other words, the profile groove in the first section and / or the second section can have a similar basic shape in the radially lower region as in the radially upper region and can optionally differ in groove width from the radially upper region.In this way, good continuity between the radial upper and lower areas can be ensured, which can be beneficial to the stability and stiffness of the tread.
[0030] The invention also relates to a vehicle tire with a tread as described above and / or below. Vehicle tires constructed according to the invention include tires of any design, in particular radial tires, and tires of any type, in particular pneumatic vehicle tires for motor vehicles such as passenger cars, light trucks, or commercial vehicles. The invention is particularly advantageous for use on vehicle tires for trucks used in long-distance transport.
[0031] The invention is described below by way of example with reference to advantageous embodiments in the accompanying drawings. They show:
[0032] Figure 1 shows a schematic and partial plan view of an embodiment of the tread according to the invention,
[0033] Figure 2 shows schematically a sectional view of a profile groove according to the section line ll-ll shown in Fig. 1,
[0034] Figure 3 shows schematically and in detail a plan view and a sectional view of an alternative embodiment of the tread according to the invention,
[0035] Figure 4 schematically shows a sectional view concentrated on a radially lower region of a profile groove in a further embodiment of a tread according to the invention.
[0036] Figure 1 shows a profile groove 1 which extends as a circumferential groove around a circumferential direction running from top to bottom in the plane of the drawing. The axial direction runs from left to right in the plane of the drawing, with an axial outer side located on the right. As can be seen from its straight contours, which are partially hidden in the plan view according to Fig. 1, a groove base 11 in the embodiment shown runs straight along the circumferential direction. In a radially upper region 2 (see also Fig. 2), lateral overhangs 6 are formed such that in a first section 7 along the longitudinal extent of the profile groove, a first groove flank 4 is convex in the direction of a second groove flank 5 and the second groove flank 5 is concave in the direction of the first groove flank 4.The lateral overhangs 6 increase in a tapered section 9 of the tread groove such that a groove width in the radially upper region 2 decreases in the direction of a second section 8. In the second section 8, the lateral overhangs 6 are designed such that the first groove flank 4 is concave in the direction of the second groove flank 5 and the second groove flank 5 is convex in the direction of the first groove flank 4. The lateral overhangs decrease again in a widened section 10 such that the groove width in the radially upper region 2 increases again in the direction of a further first section 7a. The four sections 7, 8, 9, 10 together form a quartet, which in its basic form can serve as an exclusive building block of the tread groove 1, whereby the length of different quartets arranged in series can vary with a pitch length in the tread.
[0037] Figure 2 shows a sectional view of the profile groove 1 in a plane perpendicular to the circumferential direction, according to the position marked 11-11 in Fig. 1. The radially lower region extends between a groove bottom 11 and the radial beginning of the lateral overhangs 6 on the groove flanks 4, 5, where a groove width begins to decrease radially outward. The radially upper region 2 extends between the radially outer end of the radially inner region 3 and a base surface on the running surface of the tread.
[0038] Figure 3 shows, in the left-hand part of the image, a plan view of an alternative embodiment of a tread according to the invention. In the plan view, a design of the lateral overhangs 6 in the radially upper region 2 can be seen, which is essentially familiar from the embodiment according to Fig. 1, wherein the groove width widens and narrows over a first and second section 7, 8 as well as tapering and widening sections 9, 10. In contrast to the embodiment shown in Fig. 1, however, a groove base 11 in the embodiment shown in Figure 3 does not run in a straight line, but is curved similar to the lateral overhangs 6 in the radially upper region 2. This is more clearly visible in the sectional view shown in the right-hand part of the image, wherein the sectional plane runs through the radially lower region 3 and is perpendicular to the radial direction.Accordingly, 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. Similarly, the groove flanks 4, 5 in the second section 8 are also formed according to the basic pattern of the lateral overhangs 6 in the radially upper region 2. As can be seen from the contours of the groove base 11, which are offset to the left relative to the groove center in the plane of the drawing, or axially inward in the tread, the radially lower region is asymmetrically designed.
[0039] Figure 4 shows, based on a further embodiment, an asymmetrical configuration of the radially lower region 3 of a profile groove 1 in a sectional view, wherein the sectional plane is perpendicular to the circumferential direction. The illustration is only schematic, particularly with regard to the transition to the radially upper region 2, and does not take into account, for example, any potentially advantageous and / or technically necessary roundings at the transitions to the lateral overhangs 6. The groove base 11 transitions in a first curved partial region 12 into a straight partial region of the first groove flank 4 and in a second curved partial region 13 into a straight partial region of the second groove flank 5. A radius of curvature 14 characterizing the first curved partial region 12 is smaller than a radius of curvature 15 characterizing the second curved partial region 13. In the example shown, the radii 14, 15 are in a ratio of 1:2.The groove flanks 4, 5 have angles of inclination 16, 17 with respect to the radial direction. A minimum angle of inclination 16 of the first groove flank 4 in the radially lower region 3 lies in the straight-line partial region of the first groove flank 4, and a minimum angle of inclination 17 of the second groove flank 5 in the radially lower region 3 lies in the straight-line partial region of the second groove flank 5. The two minimum angles of inclination 16, 17 have a ratio of approximately 2:5 in the example shown. The groove bottom 11 between the two curved partial regions 12, 13 is curved in the example shown. A radius of curvature 19 characterizing the groove bottom 11 is not shown in its entirety in Fig. 4. In the example shown, the radius 19 is in a ratio of 2.5 to the radius of curvature 15 characterizing the second curved partial region 13. List of reference symbols.
[0040] 1 tread groove
[0041] 2 radial upper area
[0042] 3 radial lower area
[0043] 4 first groove flank
[0044] 5 second groove flank
[0045] 6 lateral overhangs
[0046] 7 first section
[0047] 8 second section
[0048] 9 Tapering section
[0049] 10 widening section
[0050] 11 > Grooved bottom
[0051] 12 first curved section
[0052] 13 second curved section
[0053] 14 minimum radius of curvature characterizing sub-area 12
[0054] 15 minimum radius of curvature characterizing sub-area 13
[0055] 16 minimum inclination angle of the first groove flank
[0056] 17 minimum inclination angle of the second groove flank
[0057] 19 radius of curvature characterizing the groove bottom
Claims
Patent claims 1. Tread for a vehicle tire, wherein a profile groove (1) is formed in the tread 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), 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 than in the radially lower region (3) of the profile groove (1) at least along parts of a longitudinal extent of the profile groove (1), and wherein, viewed in a sectional plane perpendicular to the longitudinal extent, 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 area 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. 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. 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. Tread according to one of claims 1 to 3, characterized in that the groove flanks (4, 5) have angles of inclination (16, 17) relative to the radial direction, wherein a minimum angle of inclination (16) of the first groove flank (4) in the radially lower region (3) and a minimum angle of inclination (17) of the second groove flank (5) in the radially lower region (3) are in a ratio between 1:3 and 1:
2.
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 extent 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. Tread according to claim 5, characterized in that the first section (7) has a first length along the longitudinal extent of the profile groove (1) and that the second section (8) has a second length along the longitudinal extent 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. 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 greater than in the radially upper region (2) of the second section (8).
8. Tread according to claim 7, characterized in that the first and the second section (7, 8) are connected to one another by a tapered section (9), wherein the groove width in the radially upper region (2) of the tapered section (9) decreases from the first section (7) to the second section (8).
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 one after the other 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 Area (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. Tread according to claim 9, characterized in that a length of a quartet of sections (7, 8, 9, 10) along the longitudinal extent 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. 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 extent of the profile groove (1).
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. Tread according to one of claims 1 to 12, characterized in that the profile groove (1) has a rectilinear course in the radially lower region (3).
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. Vehicle tire with a tread according to one of claims 1 to 14.