vehicle tires

Abstract

The invention relates to a vehicle tire with a tread having a profile rib (2, 2', 3, 3') delimited by a circumferential groove (1, 1'), which is provided with trapezoidal indentations (4, 4'), each with a trapezoidal base lying on the circumferential groove (1, 1'), wherein each indentation (4, 4') on the rib outer surface (5, 5') has a boundary edge (K1) opposite the trapezoidal base and two boundary edges (K2, K3) each forming a trapezoidal leg and is delimited by a central flank (F1) and two side flanks (F2, F3). The center flank (F1) and each side flank (F2, F3) are each composed of a rectangular, radially outer boundary surface (A1, A2, A3) and a radially inner boundary surface (I1, I2, I3), wherein the radially inner boundary surface (I1, I2, I3) of the center flank (F1), viewed in cross section, extends to the radial direction at a constant angle (θ), which is greater than the angle at which the radially outer boundary surfaces (A1, A2, A3) extend.

Description

[0001] 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.

[0002] 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 separated from one another by circumferential grooves, wherein the central profile ribs along the circumferential grooves are provided with indentations that are isosceles trapezoidal in plan view, each with a trapezoidal base located 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 on 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, on 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 the susceptibility to cracking in the area of ​​the circumferential grooves.

[0003] The invention is based on the object of improving the wet and snow grip performance of a vehicle tire of the type mentioned above.

[0004] The stated object is achieved according to the invention in that the central 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 central 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.

[0005] 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.

[0006] 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.

[0007] 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.

[0008] 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.

[0009] 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.

[0010] 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.

[0011] 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.

[0012] Furthermore, it is advantageous if the maximum depth of the indentation is 60% to 90%, preferably 65% ​​to 85%, of the profile depth.

[0013] 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.

[0014] 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 advantageous effects of the indentations.

[0015] 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 adjoining 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, become progressively shorter toward the groove base and taper to a triangular apex. When driving on deep snow, snow accumulates in such pocket-like depressions, compacting them and further improving snow performance through the effect of snow-on-snow friction.

[0016] 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 projecting 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.

[0017] 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.

[0018] 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.

[0019] 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. Fig. 1a 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, Fig. 1b an enlarged plan view of detail Z 1b the Fig. 1a, Fig. 1c a section along the line Ic-Ic of the Fig. 1b, Fig. 1d an oblique view according to the Fig. 1b by the arrow S 1d indicated direction of view, Fig. 2a 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, Fig. 2b an enlarged plan view of detail Z 2b the Fig. 2a, Fig. 2c a section along the line IIc-IIc of the Fig. 2b and Fig. 2d an oblique view according to the Fig. 2b by the arrow S 2d indicated direction of view.

[0020] 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), the tires particularly preferably being pneumatic vehicle tires of radial design for rims with a rim diameter of 17.5, 19.5 or 22.5 inches.

[0021] 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), Fig. 1' ( Fig. 2a), which has a shoulder-side profile rib 2 ( Fig. 1a), Fig. 2' ( Fig. 2a) by a central profile rib 3 ( Fig. 1a), Fig. 3' ( Fig. 2a), whereby only partial areas of the profile ribs 2, 2', 3, 3' are shown.

[0022] 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' towards the tread periphery, which are open, 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, 1' 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.

[0023] The circumferential groove 1, 1' is in the radial direction in the tread depth T provided for the respective tire type UR ( Fig. 1c, Fig. 2c), which for commercial vehicle tires is usually 12.0 mm to 26.0 mm, and has - with reference to the auxiliary lines h1 containing the rib edges 6, 6' and running straight in the circumferential direction - a constant width B in the axial direction UR 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, 1' on the profile ribs 2, 3 and 2', 3' is delimited by rib flanks 7 (circumferential groove 1), 7' (circumferential groove 1') extending from the rib edges 6, 6', as well as by a groove base 8 (circumferential groove 1), 8' (circumferential groove 1') 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 area of ​​the indentations 4, 4' ( Fig. 1a, Fig. 2a).

[0024] In the following, the basic design of the cross-section of the circumferential groove 1, 1' is discussed first, followed by the design of the indentations 4, 4'.

[0025] According to Fig. 1c, the rib flanks 7 (circumferential groove 1) run in the cross-section running in axial direction in plan view (compare position of the line Ic-Ic in Fig. 1b), straight, wherein the rib flank 7 located on the shoulder-side profile rib 2 extends at an angle α to the radial direction and the rib flank 7 located on the middle profile rib 3 extends at an angle β to the radial direction, wherein the inclination of the rib flanks 7 is 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 surrounds the indentations 4 ( Fig. 1d). 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), r b (groove base section 8b), r c (groove base section 8c), where the radii r a , r b , r c and the corresponding arc lengths are coordinated in such a way that the groove base sections 8a, 8b, 8c are tangentially connected to each other. r a > r c > r b .

[0026] According to Fig. 2c and Fig. 2d, the circumferential groove 1' has a radially inner channel region 1'a, which - as Fig. 2d for the shoulder-side profile rib 2' shows - each profile rib 2', 3' in the area between circumferentially successive indentations 4' is provided with local rib projections 9', which are trapezoidal in plan view and border the indentations 4' and project into the circumferential groove 1'. The shape of the rib projections 9' results directly from the shape of the channel area 1'a and the shape of the indentations 4'. According to Fig. 2d, the rib flanks 7' are formed - due to the rib projections 9' and the channel region 1'a - exclusively from projection flanks 10' formed on the rib projections 9' and extending between circumferentially successive indentations 4', each extending from a rib edge section 6'a, which end at the channel region 1'a. Fig. As shown in Figure 2c, each projection flank 10' extends in the radial direction to a depth t1 of 55% to 65% of the profile depth T UR , wherein each projection flank 10', viewed in cross section, consists of a radially outer flank section 10'a running in the radial direction (cf. Fig. 2d) and a radially inner flank section 10'b running at an angle γ of 5° to 17° to the radial direction (cf. Fig. 2d). The radially outer flank section 10'a extends in the radial direction to a depth t2 (cf. Fig. 2d) of not more than 20%, in particular not more than 15%, of the tread depth T UR , where the depth t2 and the profile depth T UR are preferably additionally matched to one another in such a way that the depth t2 is at least 1.0 mm.

[0027] How Fig. 2d further shows, the channel region 1'a extends over the entire circumference of the circumferential groove 1' and radially inside the rib projections 9', wherein the channel region 1'a has a maximum width b in the axial direction k ( Fig. 2c, width at the widest point) of 100% to 120%, in particular of at least 105%, of the width B UR ( Fig. 2a) of the circumferential groove 1' and is limited by the already mentioned groove base 8' and to the rib projections 9' each by a projection underside 11'.

[0028] According to Fig. 1a and Fig. 2a, the indentations 4, 4' formed in the shoulder-side profile rib 2, 2' are rotated by 180° relative to the indentations 4, 4' formed in the middle 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, are spaced apart from one another by a distance a determined along the respective auxiliary line h1 or the respective rib edge section 6a E from 3.0 mm to 20.0 mm, preferably up to 10.0 mm.

[0029] The further design of the indentations 4, 4' is explained below using individual indentations 4, 4'.

[0030] How 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, 1' and coinciding with the auxiliary line h1. The indentation 4, 4' has, on the rib outer surface 5, 5', a boundary edge K1 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' ( Fig. 2d).

[0031] The following explanations regarding the boundary edges K1, K2, K3 refer to the top view. The boundary edge K1 runs at an angle δ of up to ± 2°, preferably 0°, to the circumferential direction and has an edge length c k1 , the size of which will be discussed later. The boundary edge K2 forms an angle ε of 123° to 138°, in particular 125° to 135°, with the boundary edge K1, measured in plan view across the indentation 4, 4', and the boundary edge K3 forms an angle η of 150° to 165°, in particular 153° to 163°, with the boundary edge K1, measured in plan view across the indentation 4, 4'.

[0032] The indentation 4, 4' has, in each case viewed in plan view, a maximum length c determined along the auxiliary line h1 E(Length at the longest point) from 15.0 mm to 40.0 mm, in particular from 20.0 mm to 35.0 mm, preferably from up to 30.0 mm, particularly preferably from up to 25.0 mm, a maximum width b measured between the auxiliary line h1 and the boundary edge k1 and perpendicular to the auxiliary line h1 E (Width at the widest point) from 10% to 35%, in particular from 15% to 30%, preferably up to 25%, of the maximum length c E and a maximum depth t present at the circumferential groove 1, 1', determined in the radial direction and relative to the tread periphery E ( Fig. 1c, Fig. 1d, Fig. 2c, Fig. 2d) from 55% to 95%, in particular 60% to 90%, preferably 65% ​​to 85% of the profile depth T UR ( Fig. 1c, Fig. 2c). The already mentioned edge length c k1 the boundary edge k1 is 18% to 30%, in particular at least 20%, of the maximum length c E the indentation 4, 4'.

[0033] According to Fig. 1d and Fig. 2d, the indentation 4, 4' is delimited by a central flank F1 extending from the boundary edge K1 and two side flanks F2, F3 extending from the boundary edges K2, K3 forming the trapezoidal legs, the side flanks F2, F3 being formed at the indentation 4' on the two adjacent rib projections 9' ( Fig. 2d). The center flank F1 and each side flank F2, F3 consists of a rectangular, radially outer boundary surface A1, A2, A3 (Note: boundary surface A2 hidden) and a radially inner boundary surface I1, I2, I3 (Note: boundary surface I2 in Fig. 2d). At the mutual connection points of the boundary surfaces A1, A2, A3, I1, I2, I3 as well as at the connection points of the boundary surfaces A1, A2, A3, I1, I2, I3 to the respective 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, of which in Fig. 1d and Fig. 2d some are marked.

[0034] The radially outer boundary surfaces A1, A2, A3 run in the radial direction when viewed in the cross-section perpendicular to the corresponding boundary edge K1, K2, K3 (see Fig. 1c and Fig. 2c: Boundary surface A1, compare position of the line Ic-Ic in Fig. 1b and position of line IIc-IIc in Fig. 2b) and end in the radial direction in the depth t2 ( Fig. 1c, Fig. 1d, Fig. 2c, Fig. 2d), which - as already mentioned - does not exceed 20%, in particular 15%, of the tread depth T UR and additionally preferably at least 1.0 mm.

[0035] The radially inner boundary surfaces I1, I2, I3 adjoin - neglecting the transition roundings U - at the depth t2 to the respective radially outer boundary surface A1 (boundary surface I1), A2 (boundary surface I2), A3 (boundary surfaces I3).

[0036] The radially inner boundary surface I1, viewed in the cross-section aligned in the axial direction in plan view, runs at a constant angle θ ( Fig. 1c, Fig. 2c), where - as Fig. 1d shows - the radially inner boundary surface I1 of the central surface F1 of the indentation 4 in the direction of the groove base 8 ends at the groove flank 7, more precisely at the corresponding transition rounding U, and where - as Fig. 2d shows - the radially inner boundary surface I1 of the central surface F1 of the indentation 4' merges tangentially into the groove base 8' in the direction of the groove base 8' together with the projection undersides 11'.

[0037] 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, I3 therefore runs along the radially outer boundary surface A2, A3, another triangular side of each radially inner boundary surface I2, I3 runs along the radially inner boundary surface I1 of the center flank F1 and another triangular side of each radially inner boundary surface I2, I3 runs on the circumferential groove 1, i.e. on the rib flank 7. The radially inner boundary surfaces I2, I3 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.

[0038] How Fig. 2b in combination with Fig. As shown in Figure 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 λ2 ( Fig. 2b: boundary surface I2), λ3 ( Fig. 2b: boundary surface I3), which extends towards the groove base 8' ( Fig. 2d) continuously decreases, 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).

[0039] The invention is not limited to the described embodiments.

[0040] 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. List of reference symbols 1, 1' shoulder-side circumferential groove 1'a radial inner canal area 2.2' shoulder-side profile rib 3.3' medium profile tip 4, 4' indentation 5.5' outer rib surface 6, 6' rib edge 6a, 6'a rib edge section 7, 7' rib flank 8, 8' groove base 8a central groove base section 8b outer groove base section 8c inside groove base section 9' rib protrusion 10' lead cross 10'a radial outer flank section 10'b radial inner flank section 11' projection underside A1, A2, A3 radial outer boundary surface a E Distance b E maximum width b k maximum width c E maximum length c k1 Edge length B UR Width D triangular tip F1 center flank F2, F3 side flank h1 auxiliary line I1, I2, I3 radial inner boundary surface K1, K2, K3 boundary edge r a , r b , r c radius S 1d , S 2d Arrow (direction of view) t1, t2 depth t E maximum depth T UR Tread depth U Transition rounding Z 1b , Z 2b detail α, β, γ, δ, ε, η, θ, λ2, λ3 angles QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2017 222 341 A1

[0002]

Claims

[1] Vehicle tyres with a tread having at least one groove on at least one side with a profile depth (T UR ) circumferential groove (1, 1') and having a rib outer surface (5, 5'), which, viewed in plan view, is provided with trapezoidal indentations (4, 4') elongated along the circumferential groove (1, 1') over its course, each with a trapezoidal base lying on the circumferential groove (1, 1'), wherein each indentation (4, 4') on the circumferential groove (1, 1') has a maximum depth (t E ) from 55% to 95% of the tread depth (T UR ), on the tread periphery at the trapezoid base a maximum length determined in the circumferential direction (C E ) from 15.0 mm to 40.0 mm and at the tread periphery in the axial direction a maximum width (b E ) from 10% to 35% of the maximum length (C E), wherein the indentation (4, 4') on the rib outer surface (5, 5') has a boundary edge (K1) opposite the trapezoid base and two boundary edges (K2, K3) each forming a trapezoid leg and is delimited by a central flank (F1) 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 by , that the central flank (F1) and each side flank (F2, F3) are each composed of a rectangular, radially outer boundary surface (A1, A2, A3) and a radially inner boundary surface (I1, I2, I3), wherein the radially outer boundary surfaces (A1, A2, A3) end in the radial direction at the same depth (t2) and, viewed in cross-section perpendicular to the boundary edge (K1, K2, K3), run 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 (F1), viewed in cross-section perpendicular to the boundary edge (K1), runs at a constant angle (θ) to the radial direction, which is greater than the angle at which the radially outer boundary surfaces (A1, A2, A3) run. [2] Vehicle tyre according to claim 1, characterized by that the depth (t2) at which the radially outer boundary surfaces (A1, A2, A3) end in the radial direction is at most 20%, in particular at most 15%, of the profile depth (T UR ) amounts. [3] Vehicle tyre according to claim 1 or 2, characterized bythat the depth (t2) at which the radially outer boundary surfaces (A1, A2, A3) end in the radial direction is at least 1.0 mm. [4] Vehicle tyre according to one of claims 1 to 3, characterized by that the boundary edge (K1) opposite the trapezoidal base, viewed in plan view, extends at an angle (δ) of up to ± 2°, preferably 0°, to the circumferential direction. [5] Vehicle tyre according to one of claims 1 to 4, characterized by that the boundary edge (K1) opposite the trapezoid base has an edge length (c k1 ) of 18% to 30%, in particular of at least 20%, of the maximum length (C E ) of the indentation (4, 4'). [6] Vehicle tyre according to one of claims 1 to 5, characterized bythat the boundary edge (K1) opposite the trapezoid base encloses an angle (ε, η) of 123° to 165° with each boundary edge (K2, K3) forming a trapezoid leg, wherein the angle (ε) which the boundary edge (K1) opposite the trapezoid base encloses with the one boundary edge (K2) forming a trapezoid leg is preferably 123° to 138°, in particular from 125° to 135°, and the angle (η) which the boundary edge (K1) opposite the trapezoid base encloses with the other boundary edge (K3) forming a trapezoid leg is preferably 150° to 165°, in particular from 153° to 163°. [7] Vehicle tyre according to one of claims 1 to 6, characterized by that the width (b E ) of the indentation (4, 4') 15% to 30%, preferably up to 25%, of the maximum length (C E ) of the indentation (4, 4'). [8] Vehicle tyre according to one of claims 1 to 7, characterized bythat the maximum depth (t E ) of the indentation (4, 4') 60% to 90%, preferably 65% ​​to 85%, of the profile depth (T UR ) amounts. [9] Vehicle tyre according to one of claims 1 to 8, characterized by that the maximum length (C E ) 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, characterized by that circumferentially successive indentations (4, 4') have mutual distances (a E ) of 3.0 mm to 20.0 mm, preferably up to 10.0 mm. [11] Vehicle tyre according to one of claims 1 to 10, characterized bythat the radially inner boundary surfaces (I2, I3) 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 (F1) 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 tip (D). [12] Pneumatic vehicle tyre according to one of claims 1 to 10, characterized bythat the circumferential groove (1'), viewed in cross-section, has a radially inner channel region (1'a) which provides the profile rib (2', 3') in the region between indentations (4') following one another in the circumferential direction with local rib projections (9') which adjoin the indentations (4') and project into the circumferential groove (1'), so that the channel region (1'a) runs 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 tyre according to claim 12, characterized by 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 (1') at the channel area (1'a). [14] Pneumatic vehicle tyre according to claim 12 or 13, characterized bythat the rib projections (9') each have a projection flank (10') which runs between side flanks (F2, F3) of indentations (4') which follow one another in the circumferential direction.

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