Vehicle tire

Abstract

The invention relates to a vehicle tire comprising a tread with a profiled rib (2, 2', 3, 3') that is delimited by a circumferential groove (1, 1') and is provided with trapezoidal recesses (4, 4'), each of which has a trapezoid base lying on the circumferential groove (1, 1'), wherein each recess (4, 4') has, on the rib outer surface (5, 5'), a delimiting edge (K1) lying opposite the trapezoid base and two delimiting edges (K2, K3), each of which forms a leg of the trapezoid, and each recess is delimited by a central flank (F1) and two lateral flanks (F2, F3). The central flank (F1) and the lateral flanks (F2, F3) are each composed of a rectangular, radially outer delimiting surface (A1, A2, A3) and a radially inner delimiting surface (I1, 12, l3), and when viewed in cross-section, the radially inner delimiting surface (I1, I2, l3) of the central flank (F1) runs at a constant angle (θ) relative to the radial direction, said angle being greater than the angle at which the radial outer delimiting surfaces (A1,A2, A3) run.

Description

[0001] Description

[0002] Vehicle tires

[0003] The invention relates to a vehicle tire with a tread having at least one tread rib which is delimited on at least one side by a circumferential groove designed to the tread depth and has a rib outer surface, which, viewed in plan view, is provided with trapezoidal indentations elongated along the circumferential groove over its course, each with a trapezoidal base lying on the circumferential groove, wherein each indentation on the circumferential groove has a maximum depth determined in the radial direction of 55% to 95% of the tread depth, on the tread periphery at the trapezoidal base a maximum length determined in the circumferential direction of 15.0 mm to 40.0 mm and on the tread periphery in the axial direction a maximum width of 10% to 35% of the maximum length,wherein the indentation on the outer surface of the rib has a boundary edge opposite the trapezoid base and two boundary edges each forming a trapezoid leg, and is delimited by a central flank extending from the boundary edge opposite the trapezoid base and two side flanks extending from the boundary edges forming the trapezoid legs.

[0004] Such a vehicle tire, which is a commercial vehicle tire, is known for example from DE 10 2017 222 341 A1. According to one exemplary embodiment, the tire has a tread with central profile ribs which are separated from one another by circumferential grooves, wherein the central profile ribs along the circumferential grooves are provided with indentations which are isosceles trapezoidal in plan view, each with a trapezoidal base lying at the circumferential groove. Each indentation has a maximum depth, determined in the radial direction, of 35% to 90%, in particular of up to 75%, of the tread depth at the respective circumferential groove, a maximum length, determined in the circumferential direction, of 10.0 mm to 15.0 mm at the trapezoidal base at the tread periphery, and a maximum width, determined in the axial direction, of 2.0 mm to 5.0 mm, in particular of up to 3.0 mm at the tread periphery. For example, the maximum width is 20% (=3 / 15*100) or 30% (=3 / 10*100) of the maximum length.Each indentation is defined by a central flank and two side flanks extending from the edges forming the trapezoidal legs. The central flank and the side flank are curved in such a way that they merge tangentially into the rib flank. The indentations are intended to improve grip, particularly on wet, sandy, gravelly, muddy, and / or snow-covered surfaces, while minimizing cracking in the area of ​​the circumferential grooves.

[0005] The invention is based on the object of improving the wet and snow grip performance of a vehicle tire of the type mentioned above.

[0006] The stated object is achieved according to the invention in that the center flank and each side flank are each composed of a rectangular, radially outer boundary surface and a radially inner boundary surface, wherein the radially outer boundary surfaces end at the same depth in the radial direction and, viewed in cross-section perpendicular to the boundary edge, run at an angle of 0° to 2° to the radial direction and wherein the radially inner boundary surface of the center flank, viewed in cross-section perpendicular to the boundary edge, runs at a constant angle to the radial direction, which is greater than the angle at which the radially outer boundary surfaces run.

[0007] The radially outer boundary surfaces, which run in a radial direction or essentially in a radial direction, ensure sharp and effectively stiffened boundary edges. The radially inner boundary surface of the center flank exerts a supporting and additional stiffening effect on the adjacent radially outer boundary surface, thereby providing additional stiffening to the boundary edge formed there. These measures significantly improve wet and snow grip performance.

[0008] According to a preferred embodiment, the depth at which the radially outer boundary surfaces end in the radial direction is at most 20%, in particular at most 15%, of the tread depth. As a result, the aforementioned sharp boundary edge is retained over a certain period of tread wear, making this design particularly favorable with regard to wet and snow grip performance.

[0009] According to a further preferred embodiment, the depth at which the radially outer boundary surfaces end in the radial direction is at least 1.0 mm.

[0010] A further preferred embodiment provides that the boundary edge opposite the trapezoidal base, viewed in plan view, extends at an angle of up to ± 2°, preferably 0°, to the circumferential direction. This contributes to an improvement in wet and snow grip performance under axial loads, such as those encountered when cornering.

[0011] In this context, it is further advantageous if the boundary edge opposite the trapezoidal base has an edge length of 18% to 30%, in particular of at least 20%, of the maximum length of the indentation.

[0012] A further preferred embodiment is characterized in that the boundary edge opposite the trapezoid base encloses an angle of 123° to 165° with each boundary edge forming a trapezoid leg, wherein the angle encloses the boundary edge opposite the trapezoid base with one boundary edge forming a trapezoid leg is preferably 123° to 138°, in particular 125° to 135°, and the angle encloses the boundary edge opposite the trapezoid base with the other boundary edge forming a trapezoid leg is preferably 150° to 165°, in particular 153° to 163°. Such boundary edges are advantageous for snow and wet grip properties, especially when forces act in the circumferential direction, such as those that occur during braking or traction.At the same time, the angle is so large that when driving on wet roads, there is hardly any turbulence in the water flowing in the circumferential groove, which maintains good aquaplaning behavior and thus further improves wet performance.

[0013] According to a further preferred embodiment, the width of the indentation is 15% to 30%, preferably up to 25%, of the maximum length of the indentation.

[0014] Furthermore, it is advantageous if the maximum depth of the indentation is 60% to 90%, preferably 65% ​​to 85%, of the profile depth.

[0015] Furthermore, it is advantageous if the maximum length of the indentation is 20.0 mm to 35.0 mm, preferably up to 30.0 mm, particularly preferably up to 25.0 mm.

[0016] The number of indentations is preferably selected such that successive indentations in the circumferential direction have mutual distances of 3.0 mm to 20.0 mm, preferably up to 10.0 mm, measured in the circumferential direction along the tread periphery. This further enhances the beneficial effects of the indentations.

[0017] A further advantageous embodiment is characterized in that the radially inner boundary surfaces of the side flanks are triangular surfaces, with one side of the triangle running along the adjacent radially outer boundary surface, one side of the triangle running along the center flank, and one side of the triangle running along the circumferential groove. Thus, the radially inner boundary surfaces, viewed in section parallel to the tread periphery, progressively shorten toward the groove base and taper to a triangular apex. When driving on deep snow, snow accumulates in such pocket-like depressions, compacting them in the depressions and further improving snow performance through the effect of snow-on-snow friction.

[0018] A further, alternative advantageous embodiment is characterized in that the circumferential groove, viewed in cross-section, has a radially inner channel region, which provides the tread rib, in the region between circumferentially successive indentations, with local rib projections adjacent to the indentations and extending into the circumferential groove, so that the channel region extends radially within the rib projections, and the side flanks of the indentations are formed on the rib projections. When driving on wet roads, such a channel region ensures particularly effective drainage of the tread and particularly favorable water drainage behavior, thereby further improving wet performance.

[0019] In the last-mentioned preferred embodiment, a first advantageous further development consists in that the radially inner boundary surfaces of the side flanks end in the direction of the groove base of the circumferential groove at the channel region.

[0020] A second advantageous further development of the last-mentioned preferred embodiment provides that the rib projections each have a projection flank which runs between side flanks of indentations which follow one another in the circumferential direction.

[0021] Further features, advantages and details of the invention will now be described in more detail with reference to the drawing, which schematically illustrates exemplary embodiments of the invention.

[0022] Fig. 1a is a plan view of a section of a tread of a pneumatic vehicle tire in the region of a circumferential groove with a first embodiment of the invention,

[0023] Fig. 1 b is an enlarged plan view of the detail Zib of Fig. 1a,

[0024] Fig. 1c a section along the line Ic-Ic of Fig. 1b,

[0025] Fig. 1d is an oblique view according to the viewing direction indicated by the arrow Sid in Fig. 1b, Fig. 2a is a plan view of a section of a tread of a pneumatic vehicle tire in the region of a circumferential groove with a second embodiment of the invention,

[0026] Fig. 2b is an enlarged plan view of the detail Z2b of Fig. 2a,

[0027] Fig. 2c a section along the line llc-llc of Fig. 2b and

[0028] Fig. 2d is an oblique view according to the viewing direction indicated by the arrow S2d in Fig. 2b.

[0029] Vehicle tires designed according to the invention are tires for motor vehicles, in particular for multi-track motor vehicles, and preferably commercial vehicle tires, preferably for buses or trucks (HGVs), wherein the tires are particularly preferably pneumatic vehicle tires of radial design for rims with a rim diameter of 17.5, 19.5 or 22.5 inches.

[0030] Fig. 1a and Fig. 2a each show a plan view of a section of a tread of a commercial vehicle tire in the area of ​​a shoulder-side circumferential groove 1 (Fig. 1a), 1' (Fig. 2a) which, in plan view, runs straight overall and which separates a shoulder-side profile rib 2 (Fig. 1a), 2' (Fig. 2a) from a central profile rib 3 (Fig. 1a), 3' (Fig. 2a), wherein only partial areas of the profile ribs 2, 2', 3, 3' are shown.

[0031] As will be explained in more detail, indentations 4 (profile rib 2, 3), 4' (profile rib 2', 3') are formed in the profile ribs 2, 2', 3, 3' along the shoulder-side circumferential groove 1, 1', which are open to the tread periphery, project into the profile ribs 2, 2', 3, 3' and locally widen the circumferential groove 1, 1'. The profile ribs 2, 2', 3, 3' each have a rib outer surface 5 (profile rib 2, 3), 5' (profile rib 2', 3') located in the tread periphery and a rib edge 6 (profile rib 2, 3), 6' (profile rib 2', 3') on the circumferential groove 1, T which co-delimits the rib outer surface 5, 5' and runs straight in the circumferential direction in plan view, wherein the rib edges 6, 6' are interrupted in sections by the indentations 4, 4', so that each rib edge 6, 6' is formed by rib edge sections 6a (rib edges 6), 6'a (groove edges 6') which follow one another in the circumferential direction and are aligned with one another.

[0032] The circumferential groove 1, 1' is designed in the radial direction in the tread depth TUR provided for the respective tire type (Fig. 1c, Fig. 2c), which for commercial vehicle tires is usually 12.0 mm to 26.0 mm, and has - based on auxiliary lines hi containing the rib edges 6, 6' and running straight in the circumferential direction - a constant width BUR in the axial direction, which for commercial vehicle tires is 10.0 mm to 25.0 mm. According to Fig. 1a, Fig. 1c, Fig. 2a and Fig. 2c, the circumferential groove 1, T on the profile ribs 2, 3 and 2', 3', respectively, is delimited by rib flanks 7 (circumferential groove 1), 7' (circumferential groove T) extending from the rib edges 6, 6', as well as by a groove base 8 (circumferential groove 1), 8' (circumferential groove T) extending between the rib flanks 7 and 7', respectively. The rib flanks 7, 7' thus adjoin the rib edge sections 6a, 6'a and are recessed in the region of the indentations 4, 4' (Fig. 1a, Fig. 2a).

[0033] In the following, the basic design of the cross-section of the circumferential groove 1 , T is first discussed, followed by the design of the indentations 4, 4'.

[0034] According to Fig. 1c, the rib flanks 7 (circumferential groove 1 ) run straight when viewed in the cross-section running in the axial direction in plan view (cf. position of the line Ic-Ic in Fig. 1 b), with the rib flank 7 located on the shoulder-side profile rib 2 running at an angle α to the radial direction and the rib flank 7 located on the middle profile rib 3 running at an angle β to the radial direction, the inclination of the rib flanks 7 being such that the width of the circumferential groove 1 increases in the direction towards the rib edges 6. The angles α, β are each 2° to 14°. Furthermore, the rib flank 7 surround the indentations 4 (Fig. 1 d).The groove base 8, viewed in the last-mentioned cross-section, is composed of a central groove base section 8a, an outer groove base section 8b extending to the rib flank 7 located on the shoulder-side profile rib 2, and an inner groove base section 8c extending to the rib flank 7 located on the central profile rib 3. Each groove base section 8a, 8b, 8c extends along a circular arc with a radius r. a (groove base section 8a), rb (groove base section 8b), r c (Groove base section 8c), where the radii r a , rb, r c and the corresponding arc lengths are coordinated in such a way that the groove base sections 8a, 8b, 8c are connected tangentially to each other. r a > r c > rb.

[0035] According to Fig. 2c and Fig. 2d, the circumferential groove T has a radially inner channel region 1'a, which—as Fig. 2d shows for the shoulder-side profile rib 2'—provides each profile rib 2', 3', in the region between circumferentially successive indentations 4', with local rib projections 9', which are trapezoidal in plan view and adjacent to the indentations 4' and project into the circumferential groove T. The shape of the rib projections 9' results directly from the shape of the channel region Ta and the shape of the indentations 4'. According to Fig. 2d, the rib flanks 7' - due to the rib projections 9' and the channel region Ta - are formed exclusively from projection flanks 10' formed on the rib projections 9' and extending between circumferentially successive indentations 4', each emanating from a rib edge section 6'a, which end at the channel region 1'a. As shown in Fig.2c shows, each projection flank 10* extends in the radial direction to a depth ti of 55% to 65% of the profile depth T UR, wherein each projection flank 10*, viewed in cross-section, is composed of a radially outer flank section 10'a (cf. Fig. 2d) running in the radial direction and a radially inner flank section 10'b (cf. Fig. 2d) running at an angle y to the radial direction of 5° to 17°. The radially outer flank section 10'a extends in the radial direction to a depth t2 (cf. Fig. 2d) of at most 20%, in particular of at most 15%, of the profile depth TUR, wherein the depth t2 and the profile depth TUR are preferably additionally coordinated with one another such that the depth t2 is at least 1.0 mm.

[0036] As Fig. 2d further shows, the channel region 1'a extends over the entire circumference of the circumferential groove T and radially inside the rib projections 9', wherein the channel region 1'a has a maximum width bk (Fig. 2c, width at the widest point) of 100% to 120%, in particular of at least 105%, of the width BUR (Fig. 2a) of the circumferential groove T in the axial direction and is delimited by the already mentioned groove base 8' and by a projection underside 11* to the rib projections 9'.

[0037] According to Fig. 1a and Fig. 2a, the indentations 4, 4' formed in the shoulder-side profile rib 2, 2' are rotated by 180° with respect to the indentations 4, 4' formed in the central profile rib 3, 3', viewed in plan view, and are offset in the circumferential direction, wherein the indentations 4, 4' located in the same profile rib 2, 2', 3, 3', which immediately follow one another in the circumferential direction, have a mutual distance aE of 3.0 mm to 20.0 mm, preferably of up to 10.0 mm, determined along the respective auxiliary line hi or the respective rib edge section 6a.

[0038] The further design of the indentations 4, 4' is explained below using individual indentations 4, 4'.

[0039] As shown in Fig. 1b and Fig. 2b, the indentation 4, 4', viewed in plan view, is elongated in the circumferential direction and, also viewed in plan view, has the shape of an irregular trapezoid at the level of the rib outer surface 5, 5' with a trapezoidal base (long base side of the trapezoid) located at the circumferential groove 1, T and coinciding with the auxiliary line hi. The indentation 4, 4' has on the rib outer surface 5, 5' a boundary edge Ki opposite the trapezoidal base in plan view, a boundary edge K2 extending to the rib edge 6, 6', i.e. the respective rib edge section 6a, 6'a, forming a shorter trapezoidal leg, and a boundary edge K3 extending to the rib edge 6, 6', i.e. the respective rib edge section 6a, 6'a, forming a longer trapezoidal leg. In the case of the indentation 4', the boundary edges K2, K3 are located on the two rib projections 9' adjacent to the indentation 4' (Fig. 2d).

[0040] The further, following explanations regarding the boundary edges K1, K2, K3 refer to the plan view. The boundary edge K1 runs at an angle θ of up to ± 2°, preferably 0°, to the circumferential direction and has an edge length Cki, the size of which will be discussed later. The boundary edge K2 forms an angle E with the boundary edge K1, measured in plan view across the indentation 4, 4', of 123° to 138°, in particular of 125° to 135°, and the boundary edge K3 forms an angle q with the boundary edge K1, measured in plan view across the indentation 4, 4', of 150° to 165°, in particular of 153° to 163°.

[0041] The indentation 4, 4' has, in each case viewed in plan view, a maximum length CE (length at the longest point) determined along the auxiliary line hi of 15.0 mm to 40.0 mm, in particular from 20.0 mm to 35.0 mm, preferably of up to 30.0 mm, particularly preferably of up to 25.0 mm, a maximum width bE (width at the widest point) measured between the auxiliary line hi and the boundary edge ki and perpendicular to the auxiliary line hi of 10% to 35%, in particular from 15% to 30%, preferably of up to 25%, of the maximum length CE and a circumferential groove 1, 1' present in the radial direction and relative to the

[0042] The maximum depth tE determined at the tread periphery (Fig. 1c, Fig. 1d, Fig. 2c, Fig. 2d) is 55% to 95%, in particular 60% to 90%, preferably 65% ​​to 85% of the profile depth TUR (Fig. 1c, Fig. 2c). The previously mentioned edge length CM of the boundary edge ki is 18% to 30%, in particular at least 20%, of the maximum length CE of the indentation 4, 4'.

[0043] According to Fig. 1d and Fig. 2d, the indentation 4, 4' is defined by a central flank Fi extending from the boundary edge Ki and two side flanks F2, F3 extending from the boundary edges K2, K3 forming the trapezoidal legs, wherein the side flanks F2, F3 are formed at the two adjacent rib projections 9' in the indentation 4' (Fig. 2d). The central flank Fi and each side flank F2, F3 are composed of a rectangular, radially outer boundary surface Ai, A2, A3 (Note: boundary surface A2 is hidden) and a radially inner boundary surface I1, I2, h (Note:

[0044] Boundary surface I2 is hidden in Fig. 2d). At the mutual connection points of the boundary surfaces Ai, A2, A3, I1, I2, I3 as well as at the connection points of the boundary surfaces Ai, A2, A3, I1, I2, I3 to the respectively adjoining, further surfaces, to which - as will be explained - the rib flank 7, 7' and the projection undersides 11* belong, transition curves U are formed, some of which are designated in Fig. 1d and Fig. 2d.

[0045] The radially outer boundary surfaces Ai, A2, A3 run, viewed in the cross-section running perpendicular to the associated boundary edge Ki, K2, K3 in plan view, in the radial direction (see Fig. 1c and Fig. 2c: boundary surface Ai, compare position of the line Ic-Ic in Fig. 1b and position of the line llc-llc in Fig. 2b) and end in the radial direction in each case in the depth t2 mentioned so far only in connection with the second embodiment variant (Fig. 1c, Fig. 1d, Fig. 2c, Fig. 2d), which - as also already mentioned - is at most 20%, in particular at most 15%, of the profile depth TUR and additionally preferably at least 1.0 mm.

[0046] The radially inner boundary surfaces I1, 12, 13 adjoin - neglecting the transition curves U - at the depth t2 to the respective radially outer boundary surface Ai (boundary surface I1), A2 (boundary surface I2), A3 (boundary surfaces I3).

[0047] The radially inner boundary surface I1 runs, viewed in the cross-section oriented in the axial direction in plan view, at a constant angle 6 to the radial direction (Fig. 1c, Fig. 2c), whereby - as Fig. 1d shows - the radially inner boundary surface I1 of the central surface Fi of the indentation 4 ends in the direction of the groove base 8 at the groove flank 7, more precisely at the corresponding transition rounding U, and whereby - as Fig. 2d shows - the radially inner boundary surface I1 of the central surface Fi of the indentation 4' in the direction of the groove base 8' merges tangentially into the groove base 8' together with the projection undersides 11'.

[0048] According to Fig. 1d, the radially inner boundary surfaces I2, I3 of the indentation 4 are triangular, flat surfaces, wherein the radially inner boundary surfaces I2, I3 run out in the direction of the groove base 8 along the radially inner boundary surface I1 and thus each have a triangular vertex D at their deepest point. One triangular side of each radially inner boundary surface I2, 13 therefore runs along the radially outer boundary surface A2, A3, another triangular side of each radially inner boundary surface I2, h runs along the radially inner boundary surface I1 of the center flank Fi and another triangular side of each radially inner boundary surface I2, 13 runs on the circumferential groove 1, i.e. on the rib flank 7. The radially inner boundary surfaces I2, 13 of the side flanks F2, F3 become continuously shorter in the direction of the groove base 8 when viewed in section parallel to the tread periphery.

[0049] As shown in Fig. 2b in combination with Fig. 2d, the radially inner boundary surfaces I2, I3 of the indentation 4', viewed in section parallel to the tread periphery, extend to the circumferential direction at an angle A2 (Fig. 2b: boundary surface I2), A3 (Fig. 2b: boundary surface I3), which continuously decreases towards the groove base 8' (Fig. 2d), so that each radially inner boundary surface I2, I3 is a twisting surface. Each rib projection 9' located between two indentations 4' is thus delimited by a projection flank 10', a projection underside 11', a side flank F2, and a side flank F3 (Fig. 2d).

[0050] The invention is not limited to the described embodiments.

[0051] At least one profile rib with indentations is provided. The radially outer boundary surfaces can extend at an angle of up to 2° to the radial direction.

[0052] List of reference symbols

[0053] 1 , 1' shoulder-side circumferential groove

[0054] 1'a radial inner canal area

[0055] 2.2' shoulder-side profile rib

[0056] 3, 3' middle profile tip 4, 4' indentation

[0057] 5.5' rib outer surface

[0058] 6, 6' rib edge

[0059] 6a, 6'a rib edge section

[0060] 7, 7' rib flank 8, 8' groove base

[0061] 8a central groove base section

[0062] 8b outer groove base section

[0063] 8c inside groove base section

[0064] 9' rib projection 10' projection flank

[0065] 10'a radial outer flank section

[0066] 10'b radial inner flank section

[0067] 1 T projection underside

[0068] Ai, A2, A3 radial outer boundary surface aE distance bE maximum width bk maximum width

[0069] CE maximum length

[0070] CM edge length BUR width

[0071] D triangular tip

[0072] Fi middle flank

[0073] F2, Fs side flank hi auxiliary line li, I2, h radial inner boundary surface

[0074] Ki, K2, K3 boundary edge r a , rb, r c Radius Sid, S2d Arrow (viewing direction) ti, t2. Depth tE maximum depth

[0075] TUR tread depth

[0076] U Transition rounding Zib, Z2b Detail a, ß, Y. Ö, E, q, 0, A2, A3.... Angle

Claims

Patent claims 1 . Vehicle tire with a tread having at least one profile rib (2, 2', 3, 3') which is delimited on at least one side by a circumferential groove (1, T) designed to the profile depth (TUR) and has a rib outer surface (5, 5'), which, viewed in plan view, is provided with trapezoidal indentations (4, 4') elongated along the circumferential groove (1, T) over its course, each with a trapezoidal base lying on the circumferential groove (1, T), wherein each indentation (4, 4') on the circumferential groove (1, 1') has a maximum depth (tE) determined in the radial direction of 55% to 95% of the profile depth (TUR), on the tread periphery at the trapezoidal base a maximum length (CE) determined in the circumferential direction of 15.0 mm to 40.0 mm and on the tread periphery in the axial direction a maximum width (bs) from 10% to 35% of the maximum length (CE), wherein the indentation (4, 4') on the rib outer surface (5,5') has a boundary edge (Ki) opposite the trapezoid base and two boundary edges (K2, K3) each forming a trapezoid leg, and is delimited by a central flank (Fi) extending from the boundary edge (K1) opposite the trapezoid base and two side flanks (F2, F3) extending from the boundary edges (K2, K3) forming the trapezoid legs, characterized in that the central flank (Fi) and each side flank (F2, F3) are each composed of a rectangular, radially outer boundary surface (Ai, A2, A3) and a radially inner boundary surface (I1, I2, I3), wherein the radially outer boundary surfaces (Ai, A2, A3) end in the radial direction at the same depth (t2) and, viewed in cross-section perpendicular to the boundary edge (Ki, K2, K3), extend at an angle of 0° to 2° to the radial direction, and wherein the radially inner boundary surface (I1, I2, I3) of the center flank (Fi),viewed in cross-section perpendicular to the boundary edge (K1), runs at a constant angle (0) to the radial direction, which is greater, is the angle at which the radially outer boundary surfaces (Ai, A2, A3) run.

2. Vehicle tyre according to claim 1, characterised in that the depth (t2) at which the radially outer boundary surfaces (Ai, A2, A3) end in the radial direction is at most 20%, in particular at most 15%, of the tread depth (TUR).

3. Vehicle tire according to claim 1 or 2, characterized in that the depth (t2) at which the radially outer boundary surfaces (Ai, A2, A3) end in the radial direction is at least 1.0 mm.

4. Vehicle tyre according to one of claims 1 to 3, characterised in that the boundary edge (K1) opposite the trapezoidal base, viewed in plan view, extends at an angle (5) of up to ± 2°, preferably of 0°, to the circumferential direction.

5. Vehicle tire according to one of claims 1 to 4, characterized in that the boundary edge (K1) opposite the trapezoidal base has an edge length (CM) of 18% to 30%, in particular of at least 20%, of the maximum length (CE) of the indentation (4, 4').

6. Vehicle tire according to one of claims 1 to 5, characterized in that the boundary edge (K1) opposite the trapezoid base encloses an angle (E, q) of 123° to 165° with each boundary edge (K2, K3) forming a trapezoidal leg, wherein the angle (E) which the boundary edge (K1) opposite the trapezoidal base encloses with the one boundary edge (K2) forming a trapezoidal leg is preferably 123° to 138°, in particular from 125° to 135°, and the angle (q) which the boundary edge (K1) opposite the trapezoidal base encloses with the other boundary edge (K3) forming a trapezoidal leg is preferably 150° to 165°, in particular from 153° to 163°.

7. Vehicle tire according to one of claims 1 to 6, characterized in that the width (ÖE) of the indentation (4, 4') is 15% to 30%, preferably up to 25%, of the maximum length (CE) of the indentation (4, 4').

8. Vehicle tire according to one of claims 1 to 7, characterized in that the maximum depth (tE) of the indentation (4, 4') is 60% to 90%, preferably 65% to 85%, of the tread depth (TUR).

9. Vehicle tire according to one of claims 1 to 8, characterized in that the maximum length (CE) of the indentation (4, 4') is 20.0 mm to 35.0 mm, preferably up to 30.0 mm, particularly preferably up to 25.0 mm.

10. Vehicle tyre according to one of claims 1 to 9, characterised in that circumferentially successive indentations (4, 4') have mutual distances (as) of 3.0 mm to 20.0 mm, preferably of up to 10.0 mm, from one another on the tread periphery, determined in the circumferential direction.

11. Vehicle tyres according to one of claims 1 to 10, characterised in that the radially inner boundary surfaces (I2, h) of the side flanks (F2, F3) are triangular surfaces, one side of the triangle running along the adjoining radially outer boundary surface (I2, I3), one side of the triangle running along the central flank (Fi) and one side of the triangle running on the circumferential groove (1), so that the radially inner boundary surfaces (I2, I3), viewed in section parallel to the tread periphery, become continuously shorter in the direction of the groove base (8') and terminate at a triangular apex (D).

12. Pneumatic vehicle tire according to one of claims 1 to 10, characterized in that the circumferential groove (T), viewed in cross section, has a radially inner channel region (1 'a) which provides the profile rib (2', 3') in the region between circumferentially successive indentations (4') with local rib projections (9') adjoining the indentations (4') and projecting into the circumferential groove (T), so that the channel region (Ta) is radially inside the Rib projections (9') and the side flanks (F2, F3) of the indentations (4') are formed on the rib projections (9').

13. Pneumatic vehicle tire according to claim 12, characterized in that the radially inner boundary surfaces (I2, I3) of the side flanks (F2, F3) end in the direction of the groove base (8') of the circumferential groove (T) at the channel region (Ta).

14. Pneumatic vehicle tire according to claim 12 or 13, characterized in that the rib projections (9') each have a projection flank (10') which runs between side flanks (F2, F3) of circumferentially successive indentations (4').

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