CN117412870A - Pneumatic tire for vehicle - Google Patents

Abstract

The invention relates to a pneumatic tire for a vehicle, comprising a tread having at least one tread rib (1, 2) delimited on both sides by circumferential grooves (4, 5), the at least one tread rib having a rib outer surface (6) at the tread periphery, wherein the tread rib (1, 2) has a plurality of transverse grooves (7) extending in the circumferential direction thereof in a plurality of transverse, in particular parallel to one another in plan view ^I ，7 ^II ) Configured as rib blocks (1 a,2 a), the slots each having two slot walls (9, 9') and a width (b) of 0.4mm to 1.2mm _E ) Wherein in the middle region of the tread rib (1, 2), each rib piece (1 a,2 a) is provided with a chamfer-like recess (10) on the rib outer surface (6) at one of the adjoining groove walls (9, 9'), which chamfer-like recess is spaced apart from the circumferential grooves (4, 5) and is in top view grooved (7) ^I ，7 ^II ) Longitudinally extending in the direction of extension of (a). In contrast to an end region of the chamfer-like recess (10), the micro-grooves (13) formed in the respective rib (1 a,2 a) merge into each groove (7) ^I ，7 ^II ) Wherein the micro-groove has a length (l) measured in the circumferential direction _ME ) The length is the circumferential length (l) of the associated rib (1 a,2 a) _RB ) And the micro-grooves have a width (b) of 0.5mm to 2.5mm, respectively _ME ) Depth (t) _ME ) And extends at an angle of up to + -10 DEG to the circumferential direction in top view.

Description

Pneumatic tire for vehicle

Technical Field

The invention relates to a pneumatic tire for vehicles, comprising a tread having at least one tread rib delimited on both sides by circumferential grooves, the at least one tread rib having a rib outer surface located at the tread periphery, wherein the tread rib is formed in its circumference as rib blocks with a plurality of transverse grooves (Einschnitt) extending in plan view, in particular parallel to one another, which grooves each have two groove walls and a width of 0.4mm to 1.2mm, wherein in the middle region of the tread rib each rib block is provided with a chamfer-like depression on the rib outer surface at one of the adjoining groove walls, which chamfer-like depression is spaced apart from the circumferential groove and extends longitudinally in the direction of extension of the groove in plan view.

Background

Such a tire is known, for example, from DE 10 2018 208 670 A1. Such a tire has a tread with a tread rib delimited on both sides by circumferential grooves, respectively, which is formed as a rib block by a plurality of transverse incisions having an edge-side incision section. In each edge-side groove section there is a base projection with a cover surface, which, as seen in cross section along the groove center line, is embodied in the shape of an inverted U and contributes to stabilizing the edge region of the rib. In a preferred embodiment, the slot has a central slot section extending between the slot sections on the edge side, which central slot section extends in an arc-shaped manner in plan view, wherein a recess of chamfered design adjoining the slot wall is provided on the arc-shaped outer side of the corresponding rib, which recess contributes to the water absorption in the slot.

In a pneumatic vehicle tire of the type described in the opening paragraph, the transverse cuts allow for good drainage of the tread ribs and provide advantageous flexible and sharp grip edges for grip performance. The chamfer-like recess provided in the central region of the bead is advantageous for the grip performance, in particular the braking performance, on dry road surfaces. Thus, known measures can achieve a relatively balanced grip performance on dry and wet road surfaces, however, where further improvement in wet grip performance is desired.

Disclosure of Invention

It is therefore a basic object of the present invention to improve the wet grip performance in a pneumatic vehicle tire of the type described in the opening paragraph.

According to the invention, the proposed object is achieved by: in contrast to one end region of the undercut of the chamfer-like design, the undercut formed in the respective rib merges into each undercut, which has a length, measured in the circumferential direction, which is 40% to 70% of the circumferential length of the associated rib, and which has a width and a depth of 0.5mm to 2.5mm, respectively, and extends at an angle of up to ±10° to the circumferential direction in a plan view.

When driving on wet road surfaces, the micro-grooves provided absorb water and drain it into the grooves. The orientation of the micro-grooves in or substantially in the circumferential direction ensures optimal water transport from micro-groove to groove. Since each micro-groove merges near a recess of the chamfered design, water "over" the groove is avoided. The water absorbed by the micro-grooves is thus "caught" if necessary by the undercut-like recesses and transported into the grooves. Therefore, the formation of a water film on the rib outer surface is avoided or suppressed, so that the net contact surface of the tread without the water film is significantly increased when running on a wet road, and thus the wet grip performance is further improved.

According to a preferred embodiment, the micro-grooves extend straight in a top view. This facilitates rapid transport of water absorbed by the micro-grooves.

In this connection, it is also advantageous if the micro-grooves extend at an angle of up to ±5°, in particular 0 °, to the circumferential direction in a plan view.

According to a further preferred embodiment, the micro-grooves form a first angle with respect to the groove center line, which forms an obtuse angle with the groove, on one side, and a second angle, which is smaller than the first angle, on the other side, wherein the entry of the micro-grooves in the region of the second angle forms a chamfered land region, which is formed by a corner edge extending between the micro-grooves and the groove, which is inclined with respect to the radial direction, and a land surface, which is connected to the corner edge and is embodied flush with the groove bottom of the micro-grooves. The chamfered land areas effectively counteract "rolling-up" or disadvantageous wear of the groove edges extending in the corner areas, so that the advantageous tread geometry described in terms of wet grip performance is particularly reliably retained in this area.

In this connection, it is also advantageous in the above embodiment if the corner edges have or consist of trapezoidal facets which occupy a large part of the corner edges, extend toward the micro-groove, have trapezoidal base edges on the rib outer surfaces, wherein the trapezoidal facets have limiting edges on the rib outer surfaces, and wherein the trapezoidal facets extend at an angle of 40 ° to 50 ° to the radial direction as seen in a section perpendicular to the limiting edges.

The limit edges of the trapezoidal facets are preferably oriented at an angle of 30 ° to 60 ° to the axial direction.

It is furthermore advantageous if the corner edges consist of trapezoidal facets and rectangular facets extending toward the cutout, wherein the rectangular facets have a limiting edge on the outer surface of the rib and extend at the same angle as the trapezoidal facets as seen in a section perpendicular to the limiting edge with the radial direction, and wherein the limiting edge is preferably oriented perpendicular to the cutout center line in a plan view.

According to a further preferred embodiment, the micro-grooves are located in only one of the rib halves of the tread rib adjoining each other at the rib centre line and merge into the grooves such that the first angle is located on the side of the micro-groove facing the rib centre line and the second angle is located on the side of the micro-groove facing away from the tread rib centre line. This facilitates the transfer of lateral guiding forces on wet road surfaces, thus improving wet grip performance.

Another preferred embodiment is characterized in that: the groove center line of the micro groove and the groove center line of the groove have an intersection point with the rib center line in the axial direction with a spacing of up to 25% of the width of the tread rib measured in the axial direction on the rib outer surface, wherein the spacing is preferably at least 1.5mm. Such an asymmetrical design in particular contributes to a further improvement in the drainage of the rib in a manner that is coordinated with other preferred embodiments of the invention.

According to a further preferred embodiment, the undercut consists of a first undercut section extending over a large part of its extension and at an angle of 20 ° to 50 °, in particular 40 ° to 50 °, to the axial direction, and a second undercut section extending at an angle of 0 ° to 40 °, which is less inclined to the axial direction in plan view, relative to the first undercut section, wherein a chamfer-like depression is formed in the first undercut section, and

wherein the micro-grooves merge into the grooves at the junction of the first groove section and the second groove section, or

Wherein the micro-grooves merge at the end of one groove section connected to the respective other groove section.

According to a further preferred embodiment, the chamfered recess has a length projected in the axial direction, which is 20% to 40%, in particular 25% to 35%, of the width of the tread rib, wherein the rib centre line divides the length projected in the axial direction into two sub-lengths, which are preferably each 30% to 70%, particularly preferably 35% to 65%, of the length projected in the axial direction. Thus, for grip performance, the long slot edges are advantageously maintained.

Another preferred embodiment is characterized in that: the chamfer-like depression is delimited by an inclined surface extending over a large part of the depression towards the rib outer surface, which is connected to the radially inner end of the inclined surface, reaches the groove wall, extends longitudinally in the direction of extension of the groove, has a width of 0.5mm to 1.0mm, wherein the land surface is inclined at a constant angle relative to the rib outer surface such that the depth of the chamfer-like depression, measured in the radial direction, increases in the region of the land surface towards the micro groove, wherein the depth is 2.0mm to 4.0mm at the deepest position and 50% to 70%, in particular 55% to 65%, of the depth at the deepest position. In the region of the micro-grooves which merge into the grooves, the void volume is thus maximized due to the chamfered depressions, which is further advantageous for the water absorption capacity of the grooves. The recess becomes shallower toward the other end thereof, which is advantageous in terms of rigidity of the bead.

In the above embodiment it is preferred that the chamfered recess is further defined by a ramp extending towards the outer surface of the rib, which ramp extends as a continuation of the planar surface and is connected to the end of the planar surface where the chamfered recess has its shallowest position, wherein the ramp has a width of 50 to 150%, in particular at least 100%, of the width of the planar surface and extends at a constant angle of 30 to 45 ° to the outer surface of the rib. The ramp in particular helps to stabilize the depression under load and thereby improves the illustrated manner of operation of the depression.

Furthermore, in the above embodiment, it is advantageous if the inclined surface starts from a limiting edge of the recess on the rib outer surface, which edge passes through the rib center line, wherein the recess has a width measured at the level of the rib outer surface along the limiting edge and perpendicular to the slot center line, which width is 150% to 310% of the width of the slot, wherein the width preferably increases in the direction of the micro slot and in this case 155% to 185% of the width of the slot in the narrowest position and 170% to 300% of the width of the slot in the widest position. The depression embodied in this way in terms of width also facilitates drainage of the rib.

According to a further preferred embodiment, in the region of the bead rib on its edge side, each rib piece is provided with a further recess of chamfer-like design, which reaches the adjoining circumferential groove, adjoins the groove wall, extends longitudinally in the direction of extension of the groove in plan view, which adjoins the groove wall without adjoining the recess of chamfer-like design spaced apart from the circumferential groove.

Drawings

Further features, advantages and details of the invention will now be described in detail with the aid of the accompanying drawings which schematically show embodiments of the invention. In the drawings:

figure 1 shows a simplified plan view of a circumferential section of a tread portion of a pneumatic tyre for vehicles with an embodiment variant of the invention which is developed into a plane,

figure 2 shows a section along line II-II in figure 1,

FIG. 3 shows detail Z in FIG. 1 ₃ Is an enlarged top view of (a),

fig. 4 shows detail Z in fig. 1 ₄ Is a top view of the other of the (c) and (d),

figure 5 shows a section along the line V-V in figure 4,

fig. 6 shows the arrow S according to fig. 4 ₆ An oblique view of the indicated line of sight direction,

fig. 7 shows the arrow S according to fig. 4 ₇ A view of the indicated line of sight direction,

figure 8 shows a section along line VIII-VIII in figure 4,

fig. 9 shows the arrow S according to fig. 4 ₉ Oblique view of indicated gaze direction

Fig. 10 shows a section along the line X-X in fig. 4.

List of reference numerals

1,................... Central tire rib

1a................... Rib block

2,................... Intermediate ribbing

2a................... Rib block

3,................... Intermediate ribbing

4,................... Circumferential grooves

5,................... Circumferential grooves on the shoulder side

6,................... Rib outer surfaces

7 ^I ，7 ^II ................. Grooving

7a,7b................. Cutback sections

8,................... Bottom of the slot

9,9'................. Grooving walls

10,................... Chamfer-like depressions

11a,11b,11c,11d,11e

12a................... Inclined plane

12b................... Side surfaces

12c................... Corner edges

12d................... Slope

12e................... Platform surface

13,................... Micro-kerfs

13a................... Groove bottom

13b................... Slot wall

14,................... Plateau region

15,................... Corner edges

15a,15b............... Facets

15a ',15b'............. Limit edges

16,................... Platform surface

17,................... Chamfer-like depressions

A-A................. Line (tire equatorial plane)

a ₁ ..................... Pitch of

b _A ，b _e ，b _E ，b _ME ，b _PR ，B _UR .. width

FA.................... Vehicle outside

FI.................... Vehicle inside

H _PR ................... Rib half

K,................... Grooving combination

l,................... Line

l _K ，l _A ，l _a ，l _ME ........... Length

l _A '.................. Sub-length

l _RB ................... Circumferential length

m _E ，m _ME ................. Center line of slot

m _PR ................... Rib center line

P _K ..................... Inflection point

P _S ..................... Intersection point

S ₆ ..................... Arrow (line of sight)

t _A ，t _ME ................. Depth

t _A,MIN ，t _A,MAX ............. Value

t _E ..................... Maximum depth

T _P ..................... Tread depth

Z ₃ ，Z ₄ ................. Details

α，β，γ，δ，ε，η，θ，κ，λ ₁ ，λ ₂ Angle of

Detailed Description

The vehicle pneumatic tire implemented according to the invention is a tire for a multitrack motor vehicle and preferably a tire in a child's radial structure for a passenger motor vehicle, truck or light truck (light load vehicle allowing a total weight of 7.5t or less).

Fig. 1 shows a top view of a central tread area belonging to the tread of a pneumatic tire for a vehicle. The tire equatorial plane is represented by line A-A.

The tread has in a central tread area a "central rib 1, a central rib 2 and a central rib 3, which are" bisected "by the equatorial plane of the tyre. The central rib 1 is separated from the intermediate ribs 2, 3 by circumferential grooves 4, respectively, and the intermediate ribs 2, 3 are each delimited on the tread outer side by a shoulder-side circumferential groove 5, to which the shoulder-side ribs, which are designed in particular in a known manner, are connected.

In the exemplary embodiment shown, the circumferential grooves 4,5 extend straight in plan view, in the radial direction being embodied as correspondingly provided tread depths T _P (fig. 2: circumferential grooves 4) of a depth of typically 6.5mm to 13.0mm for the preferred tire type, and these circumferential grooves have a width B in the tread periphery in the axial direction of, in particular, 6.0mm to 13.0mm _UR (FIG. 2: circumferential groove 4).

The tread ribs 1,2, 3 each have a rib outer surface 6 at the tread periphery, on which the width b measured in the axial direction is measured _PR (fig. 3: rib 2), and circumferentially encircling ribs 1,2, 3 with reference to their width b _PR In plan view, divided into two rib halves H _PR Rib center line m of (2) _PR (FIG. 3: rib 2). The central bead 3 is shown in simplified (unstructured) form and may be provided with, in particular, incisions and/or grooves which are implemented in a known manner. The central rib 1 and the intermediate rib 2 are each provided with a plurality of Y-shaped groove combinations K inclined in plan view with respect to the circumferential and axial directions, so that the tread has an asymmetrical shape with reference to the tire equatorial plane (line A-A), wherein the vehicle pneumatic tire preferably can be fitted on a vehicle, such as a passenger vehicle, PKW, such that the intermediate rib 2 faces the vehicle inside (indicated by the letter "FI") and the intermediate rib 3 faces the vehicle outside (indicated by the letter "FA"). Each groove combination K consists of grooves 7 traversing the central rib 1 or the intermediate rib 2 ^I (Ribs 1), 7 ^II (Ribs 2) and sink grooves 7 ^I 、7 ^II Is formed by micro-grooves 13.

Grooving 7 ^I 、7 ^II Extending parallel to each other inside the respective rib 1,2, seen in plan view; respectively have a inflection point P along with the trend of the grooving _K Is a slot center line m of _E (FIG. 3: undercut 7) ^II ) The method comprises the steps of carrying out a first treatment on the surface of the Dividing the rib 1,2 into rib blocks 1a (rib 1), 2a (rib 2), each having a groove 7 adjoining it ^I 、7 ^II Is cut into (a)Groove center line m _E (FIG. 3) measured circumferential Length l between _RB The method comprises the steps of carrying out a first treatment on the surface of the And each consists of a cutout section 7a that constitutes the Y trunk that extends straight in a top view and a cutout section 7b that constitutes the Y arm that extends straight in a top view. Grooving 7 ^I 、7 ^II Is oriented such that each of the slots will have its center line m _E Is connected to the end of the line l (fig. 3; cutting 7) ^II ) Inclined in the same direction as each other with respect to the axial direction, wherein the groove segments 7a forming the Y trunk merge into the same central circumferential groove 4.

The slot segments 7a extend, in plan view, through the respective rib center line m at an angle α of 20 ° to 50 °, in particular 40 ° to 50 °, with respect to the axial direction _PR (FIG. 3: undercut 7) ^II ) And has a reference slot center line m measured on the rib outer surface 6 _E Length l projected in axial direction _a (FIG. 3: undercut 7) ^II ) The length being the width b of the rib 1,2 _PR From 55% to 75%, in particular up to 70% (figure 3: rib 2). The slot segments 7b forming a Y arm extend, in plan view, at an angle β of 0 ° to 40 ° with respect to the axial direction. At the cutting groove 7 ^I The angle β of the cutout portion 7b is preferably 5 ° to 15 °, the cutout portion 7b being inclined in opposite directions relative to the cutout portion 7a in a plan view and with reference to the axial direction. At the cutting groove 7 ^II The angle β of the cutout section 7b is preferably 20 ° to 35 °, the cutout section 7b being inclined in the same direction relative to the cutout section 7a as seen in plan view and with reference to the axial direction.

Grooving 7 ^I 、7 ^II Each having a slot base 8 and two slot walls 9,9' (fig. 5: slot 7) opposite each other ^II ) Wherein the slot wall 9 is closer to the belonging line l (fig. 3: grooving 7 ^II ). Grooving 7 ^I 、7 ^II Each having a slot center line m perpendicular to the slot center line m in plan view between the slot walls 9,9 _E A constant width b measured between 0.4mm and 1.2mm, in particular up to 0.8mm _E (FIG. 3: undercut 7) ^II ) And a maximum depth t in the radial direction at its deepest position _E (FIG. 5: grooving 7) ^II ) The maximum depthAt least the degree of the tread pattern depth T _P (FIG. 2) minus 2.5mm, and maximum corresponds to the tread depth T _P Corresponding to each other. Preferably, the maximum depth t _E Maximum tread depth T _P Minus 1.0mm.

According to fig. 1, the mentioned micro-grooves 13 each form a second Y-arm of the Y-groove combination K, located in the rib half H _PR In one of (FIG. 3), reference is made to the kerf centerline m of the micro kerf _ME (fig. 3) extends straight in plan view and in the circumferential direction, alternatively at an angle of up to ±10°, in particular up to ±5°, and merges into the respective slot 7 in the illustrated embodiment at the interconnection region of the slot section 7a and the slot section 7b ^I 、7 ^II (see FIG. 3: undercut 7) ^II ). Each micro-groove 13 is associated with a groove 7 belonging to the same groove combination K ^I 、7 ^II With reference to the centre line m of the slot _ME 、m _E At one side enclose an obtuse angle lambda ₁ (see FIG. 3: undercut 7) ^II ) And at the other side at an angle lambda relative to the angle lambda ₁ Implemented at a smaller angle lambda ₂ (see FIG. 3: undercut 7) ^II ). The micro-grooves 13 merge into the grooves 7 ^I 、7 ^II In such a way that the angle lambda obtained ₁ Located in the micro-groove 13 toward the rib center line m _PR (FIG. 3) one side, the angle lambda ₂ Located at the micro-groove 13 facing away from the rib centre line m _PR Is shown (see figure 3: undercut 7) ^II )。

The micro-grooves 13 have a constant width b of 0.5mm to 2.5mm, in particular 1.0mm to 1.5mm, on the rib outer surface 6 _ME (FIGS. 3, 8) have a constant depth t in the radial direction of 0.5mm to 2.5mm, in particular 1.0mm to 1.5mm _ME (FIG. 8) and has a center line m of the slot _ME Length l measured in circumferential direction _ME (FIGS. 1, 3), which is the mentioned circumferential length l of the corresponding associated rib 1a,2a _RB 40% to 70%, in particular 45% to 65%, of (FIG. 1). As for the cutting 7 ^II Figure 3 of (2) shows the kerf centerline m of the micro kerf 13 _ME And slot 7 ^I 、7 ^II Is a slot center line m of _E With an intersection point P _S The intersection point and the ribCenter line m _PR With a spacing a in the axial direction ₁ The spacing being up to the width b of the rib 1,2 _PR 25% of (a), wherein the distance a ₁ Preferably at least 1.5mm. According to fig. 8, the micro groove 13 is delimited in cross section by a groove bottom 13a and two groove walls 13b extending in the radial direction.

As also shown in fig. 1, each rib block 1a,2a is provided with a chamfer-like design recess 10 (fig. 6, 7) adjoining the groove segment 7a and the groove wall 9 in the middle region of the tread rib 1,2, which recess passes through the rib center line m _PR (FIG. 3: rib 2 a), at the slot center line m _E (FIG. 3: undercut 7) ^II ) Is elongated in the direction of extension of the rib 2a, other design aspects of the recess are further described below by means of the recess 10 in the rib 2a.

According to fig. 3, the depression 10 has a trapezoidal shape, seen in plan view, with a trapezoidal base lying on the cutout section 7a and a length l measured on the trapezoidal base and projected in the axial direction _A The length being the width b of the rib 2 _PR From 20% to 40%, in particular from 25% to 35%, wherein the recess 10 is designed such that the rib centre line m _PR Length l _A Divided into lengths l respectively _A 30% to 70%, in particular 35% to 65%, of the two sub-lengths l _A ' and wherein, opposite one end region of the recess 10, the corresponding micro-groove 13 merges into the groove 7 ^II (FIG. 1: also applicable to the kerf 7) ^I )。

According to fig. 4 and 6, the depression 10 has on the rib outer surface 6 a limiting edge 11a opposite the bottom edge of the trapezoid in plan view, reaching the limiting edge 11b of the slot wall 9 forming a trapezoid waist, forming a limiting edge 11c of the other trapezoid waist, and also reaching the short limiting edge 11d of the slot wall 9.

As shown in fig. 4, the limit edge 11a passes through the rib center line m _PR In top view, extends straight and at an angle γ of 35 ° to 50 °, in particular 40 ° to 50 °, to the axial direction, wherein the angle γ is in embodiments 2 ° to 10 °, in particular 4 ° to 8 °, smaller than the mentioned angle α of the slot section 7a, and the limiting edge has a projection in the axial directionLength of l _K The length is the length l of the recess 10 _A From 60% to 80%, in particular from 65% to 75%. The recess 10 has a center line m perpendicular to the slot along the limit edge 11a _E And a width b measured at the level of the rib outer surface 6 _A The width continuously increases in the direction of the slot segment 7b over the extension of the limit edge 11a and is the slot 7 ^I 、7 ^II Width b of (2) _E 150% to 310%. Width b _A Preferably the slot 7 is at the finest point present along the limit edge 11a ^I 、7 ^II Width b of (2) _E 155% to 185% of the limit edge 11a, and is the notch 7 at the widest position existing along the limit edge 11a ^I 、7 ^II Width b of (2) _E 170% to 300%.

The limit edge 11b extends at an angle of + -10 DEG to the circumferential direction, in particular in the circumferential direction, relative to the limit edge 11c, closer to the slot section 7b, wherein in this embodiment the line extending in the extension of the limit edge 11b is to the slot centre line m _E Is referred to as inflection point P _K And (5) intersecting. The limit edge 11c extends at an angle of + -10 deg. to the axial direction as seen in top view. A very short limit edge 11d is connected to the limit edge 11c and is perpendicular to the slot centre line m in top view _E Extending.

As also shown in fig. 4 and 6, the recess 10 is defined by: inclined surface 12a extending over a large part of recess 10 in a top view (fig. 4) from limit edge 11a, side surface 12b from limit edge 11b, triangular corner surface 12c from limit edge 11c, and substantially rectangular and in top view with slot center line m _E (fig. 4) a parallel longitudinally extending platform surface 12e, and a ramp surface 12d extending as a continuation of the platform surface 12e in top view (fig. 4) and towards the very short limit edge 11d. According to FIG. 5, in a direction perpendicular to the slot centerline m _E Viewed in an extended section (see the position of the section line V-V in fig. 4), the inclined surface 12a appears to be a straight line and extends at a constant angle δ of 40 ° to 50 °, in particular 43 ° to 48 °, to the radial direction. The side surface 12b extends in a radial direction or is seen in a section perpendicular to the limit edge 11bAn angular extension of up to 2 ° (fig. 4, 6). According to fig. 6, the triangular corner faces 12c are inclined with respect to the radial direction and have a continuously decreasing width from the limit edge 11c towards the radially inner tip thereof. The platform surface 12e has a constant width b of 0.5mm to 1.0mm _e (fig. 4) and has a straight-running limit edge 11e (fig. 6) on the slot main section 7a, which is inclined according to fig. 7 together with the flat surface 12e at a constant angle epsilon relative to the rib outer surface 6, so that the recess 10 has a continuously decreasing depth t measured in the radial direction along the limit edge 11e from the side surface 12b to the ramp surface 12d _A . Depth t _A Has a value t of 2.0mm to 4.0mm at the deepest position of the recess 10 present on the limit edge 11e _A,MAX And has a value t at the shallowest position of the recess present on the limit edge 11e _A,MIN The value is the value t _A,MAX From 50% to 70%, in particular from 55% to 65%. According to fig. 4, the ramp 12d has a constant width b _d The width is the width b of the platform surface 12e _e In particular at least 100%, wherein the sloping surface 12d extends at a constant angle η of 30 ° to 45 ° with respect to the rib outer surface 6, which is embodied at an angle ε, as shown in FIG. 7.

According to fig. 1, in the exemplary embodiment shown, at the inlet of each micro-groove 13, the mentioned embodiment is implemented at a smaller angle λ ₂ Is formed with a chamfered land region 14. As shown in fig. 9, the land area 14 is formed or defined by a corner edge 15 and a land 16 (shown in phantom) connected to the edge. The corner edge 15 extends between the micro groove 13 and the groove section 7b, so that one groove wall 13b of the micro groove 13 ends at the corner edge 15 (see fig. 4: right groove wall 13 b), while the other groove wall 13b of the micro groove 13 (see fig. 4: left groove wall 13 b) reaches the groove main section 7a together with the groove bottom 13a (see fig. 4). According to fig. 9, the corner edges 15 consist of trapezoidal facets 15a extending toward the micro-groove 13 with trapezoidal base edges on the rib outer surface 6 and rectangular facets 15b extending toward the groove section 7b. The trapezoidal edge surface 15a occupies a large part of the edge 15 and is embodied as an isosceles trapezoid, and has a limit edge 15a' on the rib outer surface 6, which limit edge makes an angle of 30 ° to 60 ° with the axial directionθ (fig. 4) is oriented and extends at an angle κ (fig. 10, refer to the position of the section line X-X in fig. 4) of 40 ° to 50 ° from the radial direction as seen in a section perpendicular to the limit edge 15 a'. According to fig. 4, the rectangular facets 15b have on the rib outer surface 6 a center line m of the slot perpendicular in plan view _E An extended limit edge 15b 'and, seen in a section perpendicular to the limit edge 15b', the rectangular facets extend at the same angle (not shown) as the angle κ to the radial direction. The land surface 16 is substantially triangular in plan view and is implemented flush with the groove bottom 13a of the micro groove 13 (refer to fig. 9), corresponding to the shape of the corner ridge 14. Thus, the flat surface 16 is a planar continuation of the slot bottom 13a and is therefore at the mentioned depth t _ME (fig. 8) extends above.

According to fig. 1, in the embodiment shown, each slot 7 in the slot section 7a ^I The slot wall 9' is further provided with a chamfer-like depression 17 at the slot center line m _E Is stretched up to the corresponding circumferential groove 4 in the direction of extension (not shown in fig. 1). The chamfer-like depression 17 corresponds in its design to the chamfer-like depression 10 rotated 180 ° in plan view, wherein, unlike the depression 10, no limiting edge 11b (fig. 4) and no side surface 12b (fig. 4) emerge from the end of the depression 17 located at the circumferential groove 4.

The invention is not limited to the described embodiments.

The tread has at least one tread rib with corresponding sipes and micro-sipes. The depth of the micro kerfs may continuously increase toward the kerfs. The slot may also extend generally straight or arcuate in plan view. The micro-grooves may also have an arcuate course in plan view, wherein such micro-grooves each extend at an angle of up to ±10° to the circumferential direction, viewed in plan view, and with reference to a line connecting the ends of the groove center lines thereof. The chamfered land areas are optional.

Claims (15)

1. A vehicle pneumatic tire has a tread having at least one bounded on both sides by circumferential grooves (4, 5), respectively-a tread rib (1, 2), said at least one tread rib having a rib outer surface (6) at the tread periphery, wherein said tread rib (1, 2) is provided with a plurality of transverse grooves (7) extending in its circumferential direction, in particular parallel to each other in a top view ^I ，7 ^II ) Configured as rib blocks (1 a,2 a), the slots each having two slot walls (9, 9') and a width (b) of 0.4mm to 1.2mm _E ) Wherein in the central region of the tread rib (1, 2), each rib piece (1 a,2 a) is provided with a chamfer-like design recess (10) on the rib outer surface (6) adjacent to one of the groove walls (9, 9'), which chamfer-like design recess is spaced apart from the circumferential groove (4, 5) in the groove (7) in a plan view ^I ，7 ^II ) Is extended longitudinally in the extending direction of (a),

it is characterized in that the method comprises the steps of,

in contrast to an end region of the chamfer-like recess (10), the micro-grooves (13) formed in the respective rib (1 a,2 a) merge into each groove (7) ^I ，7 ^II ) Wherein the micro-grooves have a length (l) measured in the circumferential direction _ME ) The length is the circumferential length (l) of the associated rib (1 a,2 a) _RB ) And the micro-grooves have a width (b) of 0.5mm to 2.5mm, respectively _ME ) Depth (t) _ME ) And extends at an angle of up to + -10 DEG to the circumferential direction in top view.

2. Pneumatic vehicle tyre according to claim 1, characterized in that the micro-grooves (13) extend straight in plan view.

3. Pneumatic vehicle tyre according to claim 1 or 2, characterized in that the micro-grooves (13) extend in plan view at an angle of up to ±5°, in particular 0 °, to the circumferential direction.

4. A pneumatic tyre for vehicles according to one of claims 1 to 3, characterized in that said micro-grooves (13) and said grooves (7) ^I ，7 ^II ) With reference to the centre line of the slot (m _ME ，m _E ) A first side surrounding an obtuse angleAn angle (lambda) ₁ ) And on the other side, a second angle (lambda) is formed smaller than the first angle ₂ ) Wherein at said second angle (lambda ₂ ) A land area (14) forming a chamfer at the junction of the micro-groove (13) in the area of (2) the land area being defined by the junction of the micro-groove (13) and the groove (7) ^I ，7 ^II ) A corner edge (15) extending therebetween and inclined relative to the radial direction, and a platform surface (16) connected to the corner edge and embodied flush with the groove bottom (13 a) of the micro groove (13).

5. Pneumatic vehicle tire according to claim 4, characterized in that the corner bead (15) has or consists of a trapezoidal bead surface (15 a) which occupies a large part of the corner bead (15), extends towards the micro-groove (13), has a trapezoidal base on the rib outer surface (6), wherein the trapezoidal bead surface (15 a) has a limiting edge (15 a ') on the rib outer surface (6), and wherein the trapezoidal bead surface (15 a) extends at an angle (κ) of 40 ° to 50 ° to the radial direction as seen in a section perpendicular to the limiting edge (15 a').

6. A pneumatic tyre for vehicles as claimed in claim 5, wherein the limit edge (15 a') of said trapezoidal land (15 a) is oriented at an angle (θ) of 30 ° to 60 ° to the axial direction.

7. Pneumatic vehicle tyre according to claim 4 or 5, characterized in that said corner edges (15) are defined by said trapezoidal facets (15 a) and directed towards said undercut groove (7) ^I ，7 ^II ) An extended rectangular prism surface (15 b), wherein the rectangular prism surface (15 b) has a limiting edge (15 b ') on the rib outer surface (6) and extends at the same angle (k) as the trapezoid prism surface (15 a) with respect to the radial direction as seen in a section perpendicular to the limiting edge (15 b '), and wherein the limiting edge (15 b ') is preferably perpendicular to the slot center line (m) in a top view _ME ) Orientation.

8. Pneumatic vehicle tyre according to one of claims 4 to 7, characterized in that said micro-grooves (13) are located only in the rib centre line (m) of said tread rib (1, 2) _PR ) Rib half parts (H) _PR ) In one of them and merge into the slot (7) ^I ，7 ^II ) Such that the first angle (lambda ₁ ) Located in the micro-groove (13) towards the rib centre line (m) _PR ) And the second angle (lambda ₂ ) Is located in the micro-groove (13) facing away from the rib centerline (m) _PR ) Is provided.

9. Pneumatic vehicle tire according to one of claims 1 to 8, characterized in that the groove center line (m _ME ) And the cutting groove (7) ^I ，7 ^II ) Is a slot center line (m) _E ) Has an intersection point (P) _S ) The intersection point is aligned with the rib center line (m _PR ) With a spacing (a) in the axial direction ₁ ) Said spacing being up to the width (b) of the rib (1, 2) measured in the axial direction on the rib outer surface (6) _PR ) Wherein the spacing (a) ₁ ) Preferably at least 1.5mm.

10. Pneumatic vehicle tyre according to one of claims 1 to 9, characterized in that said undercut groove (7 ^I ，7 ^II ) Consisting of a first groove section (7 a) extending over a large part of its extension and at an angle (alpha) of 20 DEG to 50 DEG, in particular 40 DEG to 50 DEG, relative to the axial direction, and a second groove section (7 b) extending at an angle (beta) of 0 DEG to 40 DEG, inclined less in plan view relative to the first groove section (7 a) with respect to the axial direction,

wherein the chamfer-like depression (10) is formed in the first cutout section (7 b) and

-wherein the micro-groove (13) merges into the groove (7) at a connection region of the first groove section (7 a) and the second groove section (7 b) ^I ，7 ^II ) In (a) or

-wherein the micro-slots (13) merge at the end of one slot segment (7 a) connected to the respective other slot segment (7 b).

11. Pneumatic vehicle tire according to one of claims 1 to 10, characterized in that the chamfered recess (10) has a length (l _A ) Said length being the width (b) of said rib (1, 2) _PR ) From 20% to 40%, in particular from 25% to 35%, wherein the rib centre line (m _PR ) The length (l) to be projected toward the axial direction _A ) Divided into two sub-lengths (l _A '), said sub-lengths are preferably each a length (l) projected towards the axial direction _A ) From 30% to 70%, particularly preferably from 35% to 65%.

12. A pneumatic tyre for vehicles as claimed in one of claims 1 to 11, characterized in that said chamfer-like recess (10) is delimited by an inclined surface (12 a) extending over a substantial part of said recess (10) towards said rib outer surface (6) and a land (12 e) connected to a radially inner end of said inclined surface (12) reaching said groove wall (9), along said groove (7) ^I ，7 ⁷ ) Longitudinally extending in the extending direction and having a width (b) _e ) From 0.5mm to 1.0mm, wherein the Ping Taimian (12 e) is inclined at a constant angle (ε) with respect to the rib outer surface (6) such that the depth (t _A ) In the region of the platform surface (12 e) in the direction of the micro-grooves (13), wherein the depth (t) _A ) At the deepest position (t _A,MAX ) Is 2.0mm to 4.0mm, and at the shallowest position (t _A,MIN ) Is at the deepest position (t _A,MAX ) Depth at (t) _A ) From 50% to 70%, in particular from 55% to 65%.

13. Pneumatic vehicle tyre according to claim 12, characterized in that said chamfer-like recess (10) is further delimited by a sloping surface (12 d) extending towards said rib outer surface (6), said sloping surface extending as a continuation of said landing surface (12 e) and being connected toThe end of the platform surface (12 e) at which the chamfered recess (10) has its shallowest position (t) _A,MIN ) Wherein the ramp (12 d) has a width (b) _d ) Is the width (b) of the platform surface (12 e) _e ) And in particular at least 100% and the ramp extends at a constant angle (eta) of 30 DEG to 45 DEG to the rib outer surface (6).

14. A pneumatic tyre for vehicles as claimed in claim 12 or 13, wherein said inclined surface (12 a) extends from said recess (10) on said rib outer surface (6) through said rib centre line (m _PR ) Starting from a limit edge (11 a) of the rib, wherein the recess (10) has a recess extending along the limit edge (11 a) at the level of the rib outer surface (6) and perpendicular to the slot center line (m) _ME ) Measured width (b) _A ) The width is the width of the slot (7 ^I ，7 ^II ) Width (b) of (b) _E ) 150% to 310%, wherein the width (b) _A ) Preferably in the direction of the micro-grooves (13), and here in the narrowest position is the groove (7) ^I ，7 ^II ) Width (b) of (b) _E ) And at the widest position is the slot (7) ^I ，7 ^II ) Width (b) of (b) _E ) 170% to 300%.

15. Pneumatic vehicle tire according to one of claims 1 to 14, characterized in that in the region of the edge side of the tread rib (1, 2) each rib piece (1 a,2 a) is provided with a further recess (17) of chamfered design, which reaches the adjoining circumferential groove (4, 5), the adjoining groove wall (9'), along the groove (7 in top view ^I ，7 ^II ) The groove walls (9') adjoining the further depressions do not adjoin the chamfer-like depressions (10) spaced apart from the circumferential grooves (4, 5).