VEHICLE AIR TIRES

Description

[0001] The invention relates to a vehicle pneumatic tire with a tread having at least one shoulder-side row of profile blocks, which are separated from each other by inclined grooves running parallel to each other in plan view and extending to the tread depth, and are each bounded on the inside of the tread by a groove which opens into two successive inclined grooves in the circumferential direction and which, in plan view, is inclined opposite to the circumferential direction to the inclined grooves, wherein the groove has a width of 3.0 mm to 7.0 mm, a maximum depth of 65% to 100% of the tread depth, groove walls extending from the tread periphery and a groove base groove extending at its maximum depth, opening into the inclined grooves, and extending obliquely through the groove in plan view.

[0002] Such a vehicle pneumatic tire is known, for example, from EP 2 501 561 B1. In the described embodiment, the vehicle pneumatic tire has a tread with a shoulder-side row of tread blocks, each shoulder-side tread block being adjacent to a semi-central tread block. Circumferentially successive tread blocks are separated from one another by oblique grooves. Between the oblique grooves are grooves that separate the shoulder-side tread blocks from the semi-central tread blocks. Viewed from above, these grooves are straight, inclined opposite to the oblique grooves in the circumferential direction, and run at an angle of, for example, 20° to the circumferential direction. In cross-section, the grooves are bounded by a groove base running parallel to the tread periphery and two groove walls extending radially.At the base of each groove, a cut-like groove base groove with a width of 0.4 mm to 1.5 mm ("groove") is formed, which extends obliquely through the groove in plan view and crosses the groove across its entire width. The grooves have a width of, for example, 3.0 mm to a maximum depth ("groove depth TN") of 10% to 120% of the tread depth, where the tread depth is 8.0 mm to 10.0 mm. Preferably, the maximum groove depth is 3.5 mm less than the tread depth, so that the maximum groove depth is approximately 56% of the tread depth for a tread depth of 8.0 mm and 65% of the tread depth for a tread depth of 10.0 mm. The tire is intended to exhibit low rolling resistance and uniform wear.

[0003] From DE 10 2017 203 225 A1, a pneumatic tire for vehicles is known with a directional tread featuring V-shaped diagonal grooves extending across the width of the tread. In each half of the tread, at least two straight grooves are formed between successive diagonal grooves, inclined in the opposite direction to the diagonal grooves with respect to the circumferential direction. The angle between the grooves and the circumferential direction decreases from groove to groove with increasing distance from the tire's equatorial plane, thereby offering advantages in terms of water drainage and abrasion resistance. Preferably, a cut extends from the base of each groove, passing through the groove, which slightly reduces the lateral stiffness of the tread and thus improves ride comfort.

[0004] WO 2022 / 253372 A1, published only after the priority date of the present application, describes a vehicle pneumatic tire with a tread having a similar groove and a groove base groove in which the inclined surfaces of the groove walls form an angle of inclination to the radial direction which remains constant over the entire longitudinal extent of the groove.

[0005] In pneumatic tires of the type mentioned above, the grooves, each encompassing a groove base, have a beneficial effect on tread drainage while maintaining high tread stiffness. The shoulder-side tread blocks feature block edges on the grooves running between the diagonal grooves. Due to the inclination (angle) of the grooves relative to the circumferential direction, these edges have a longer length compared to block edges running exactly in the circumferential direction. This makes the block edges advantageous for handling characteristics under winter driving conditions. Because of the groove inclination, the shoulder-side tread blocks exhibit varying lateral stiffness along their circumference, which can lead to a reduction in handling characteristics, particularly a decrease in power transmission from the tire to the road surface.

[0006] The invention is therefore based on the objective of demonstrating a possibility for improving the handling characteristics of a vehicle pneumatic tire of the type mentioned at the outset.

[0007] The problem stated in the invention is solved by the fact that the groove walls of the groove, viewed in cross-section, are each composed over the entire extent of the groove of a radially outer flank surface extending at an angle of 0° to 10° to the radial direction and an inclined surface adjoining this, extending towards and sloping down to the groove base, and extending at an angle to the radial direction, wherein the angle at which the inclined surface of one groove wall extends and the angle at which the inclined surface of the other groove wall extends change their magnitudes continuously and in opposite directions over the longitudinal extent of the groove, wherein the smallest value of the angle of each inclined surface is at least the magnitude of the angle of the radially outer flank surface adjoining the respective inclined surface.

[0008] The inclined surfaces are therefore surfaces that twist along the length of the groove, allowing the transverse stiffness of the respective shoulder-side profile block to be specifically influenced over its circumference and thus the handling characteristics in a particularly advantageous way.

[0009] According to a preferred embodiment, the groove has an outer groove end and an inner groove end, wherein the angle at which the inclined surface of the groove wall formed on the respective shoulder-side profile block runs is greatest at the outer groove end. This provides stronger support for the shoulder-side profile block at its axially narrower region located at the outer groove end than at its axially wider region located at the inner groove end, resulting in particularly uniform transverse stiffness across its circumference. This further improves handling characteristics.

[0010] According to an advantageous further development of the last-mentioned preferred embodiment, the tread is designed to be directionally oriented, wherein the outer end of the groove on the tread is an incoming groove end that first enters the surface when the tire rolls during forward travel, and the inner end of the groove on the tread is a trailing groove end.

[0011] According to a further preferred embodiment, the groove base, viewed from above, is straight with respect to its groove centerline. This improves the water drainage capacity in the groove base, which is advantageous for handling characteristics on wet roads.

[0012] Another preferred embodiment is characterized in that the groove and the groove base groove, viewed from above, run straight with respect to their groove centerlines, wherein the groove centerline of the groove base groove is inclined circumferentially or in the same direction as the groove centerline. This is also advantageous for good handling characteristics on wet roads.

[0013] In the latter preferred embodiment, an advantageous further development consists in the fact that the groove base groove and the groove, viewed in plan view and with respect to their groove centerlines, each run at an angle to the circumferential direction, wherein the angle at which the groove base groove runs to the circumferential direction is smaller, in particular by 1° to 10°, preferably by 3° to 5°, than the angle at which the groove runs to the circumferential direction.

[0014] Furthermore, in the last-mentioned preferred embodiment, it is advantageous if the groove, viewed from above, runs at an angle of 20° to 40°, in particular 25° to 35°, relative to its groove centerline and circumferential direction.

[0015] Another preferred embodiment provides that the angles of the inclined surfaces change continuously, i.e., uniformly. This supports the shoulder-side profile blocks in a manner that is particularly advantageous for handling characteristics.

[0016] According to a further advantageous embodiment, the groove base, viewed in cross-section perpendicular to its groove centerline in plan view, is bounded by a U-shaped groove base with a termination edge at each inclined groove, wherein preferably the groove walls are bounded at the point where the inclined surfaces have the smallest angle by a termination edge that connects tangentially to the termination edge of the groove base without a kink, and in particular is straight. This is particularly advantageous for handling characteristics on wet roads.

[0017] Preferably, the largest and smallest values ​​of the angles of the inclined surfaces coincide. This increases the lateral stiffness of each shoulder-side profile block in a particularly uniform manner. Stiffness jumps to the adjacent profile positive are thus reliably avoided or reduced, which is also advantageous for handling characteristics.

[0018] According to a further preferred embodiment, the groove base groove has two boundary edges at the radially inner ends of the inclined surfaces that are straight in plan view and run at a constant distance in the radial direction from the level of the profile depth.

[0019] In the latter preferred embodiment, it is advantageous if the groove base has a constant width of 15% to 35%, particularly 20% to 30%, of the groove width, as determined in plan view perpendicular to its groove centerline and between the boundary edges. This allows the profile positives adjacent to the groove containing the groove base, including the shoulder-side profile blocks, to support each other in a manner advantageous for handling characteristics under load.

[0020] Furthermore, in the latter preferred embodiment, it is advantageous if the groove base has a constant depth of 0.30 mm to 1.50 mm, measured radially to the boundary edges, particularly up to 1.00 mm, preferably up to 0.75 mm. This is also advantageous for handling characteristics on wet roads.

[0021] Another advantageous embodiment is characterized by the fact that the radially outer flank surfaces connect to the inclined surfaces at a constant depth, determined radially, of 60% to 75% of the maximum groove depth. This contributes to maintaining a groove cross-section that is advantageously large for water drainage and improves the stiffening effect of the inclined surfaces, which extend to a height, determined radially, that correlates with the aforementioned depth. Thus, the handling characteristics are further improved – both on dry and wet roads.

[0022] For improved handling characteristics on dry pavement, it is further advantageous if the groove – viewed from above and with reference to a point located centrally on its groove centerline – has a distance of 7% to 30%, in particular 12% to 25%, preferably 17% to 23%, of the width of the tread's contact patch, measured axially at the periphery of the tread. Consequently, the shoulder-side profile blocks are designed to be correspondingly wide in the axial direction, which is beneficial for handling characteristics on dry pavement.

[0023] Further features, advantages, and details of the invention will now be described in more detail with reference to the drawing, which schematically illustrates an embodiment of the invention. The drawing shows... Fig. 1 a simplified top view of a circumferential section of a tread of a vehicle pneumatic tire developed into a plane with an embodiment of the invention, Fig. 2 an enlarged top view of detail Z 2 of the Fig. 1 , Fig. 3 a section along line III-III of the Fig. 2 and Fig. 4 an oblique view according to the in Fig. 2 The direction of view is indicated by the arrow S 4.

[0024] Vehicle pneumatic tires designed according to the invention are tires for motor vehicles, in particular for multi-track motor vehicles, preferably for passenger cars, vans or SUVs, and preferably radial tires for rims with an integer rim diameter of 13 inches to 24 inches, in particular from 18 inches to 23 inches.

[0025] Fig. 1 Figure 1 shows a top view of a tread of a vehicle tire. The tire's equatorial plane is marked by line AA, and the lateral edges of the tread's contact patch are indicated by two lines L. The contact patch corresponds to the statically determined footprint (determined with a tire mounted on a standard rim, load at 70% of the maximum load capacity, internal pressure 85% of the standard pressure, according to ETRTO standards) and has a width B in the axial direction. The tread 1 has a directional tread pattern and must be mounted on the vehicle such that it exhibits the rolling direction indicated by arrow R when driving forward.

[0026] The tread is provided with inclined grooves 1 that, when viewed from above, extend in a V-shape across the tread width and form the main (drainage) grooves of the tread. When the tire is traveling forward (arrow R), the inclined grooves 1 first enter the contact patch with the ground at their inner ends. The inclined grooves 1 extending towards one edge of the tread are offset circumferentially from those extending towards the other edge. The inclined grooves 1 extend beyond the tire's equatorial plane (line AA) and each merge into an inclined groove 1 extending towards the opposite lateral edge of the tread. Each inclined groove 1 has a center line m SR that, when viewed from above, follows the groove's path. In the radial direction, the grooves are aligned to the intended tread depth T SR (in Fig. 3 The grooves (indicated) are typically 6.5 mm to 12.0 mm wide and have a width BSR, measured in plan view perpendicular to the groove centerline mSR at the tread periphery, increasing continuously towards the tread edge from 2.5 mm to 14.0 mm, in particular from 3.0 mm to 10.0 mm. Viewed in plan view and with respect to a straight auxiliary line h1 connecting the ends of the associated groove centerline mSR, they run at an angle α of 50° to 70° to the circumferential direction. The oblique grooves 1 running towards the same tread edge are parallel to each other with respect to the groove centerlines mSR. The width BSR is determined perpendicular to a tangent (not shown) drawn to the groove centerline mSR. Preferably, the width BSR at the widest point within the ground contact area is at least 3.5 mm.

[0027] In the illustrated embodiment, the inclined grooves 1 each consist of a groove section 1a on the inside of the tread, which is continuously curved in plan view, and a shoulder-side groove section 1b, which is inclined more steeply in the circumferential direction than the groove section 1a on the inside of the tread. The groove section 1a on the inside of the tread ends on the outside of the tread, with respect to the respective groove centerline m SR, in front of the lateral edge of the ground contact area (line L) at an axial distance a 1 of 8% to 25% of the width B of the ground contact area.

[0028] In each half of the tread, between circumferentially adjacent inclined grooves 1, there is a groove 2, further inward on the tread, and a groove 3, further outward on the tread. The grooves 2 open into the respective groove sections 1a on the inside of the tread, run straight when viewed from above and are inclined in the opposite direction to the inclined grooves 1 with respect to the circumferential direction, have a width of 1.0 mm to 6.0 mm, in particular at least 2.5 mm, determined in plan view perpendicular to their direction of extension, and a maximum depth (depth at the deepest point) of 70% to 100% of the profile depth T SR ( Fig. 3 ) on. The grooves 3 run either between two groove sections 1a on the inside of the tread, between a groove section 1a on the inside of the tread and a groove section 1b on the shoulder side, or - in another variant not shown - between two groove sections 1b on the shoulder side.

[0029] The tread, due to the described profiling, has in each half of the tread shoulder tread blocks 4 belonging to shoulder-side tread block rows 4', adjacent semi-central tread blocks 5, and central tread blocks 6 intersected by the tire equatorial plane (line AA). The tread blocks 4, 5, 6 are preferably each with Fig. 1 not shown incisions with a width of 0.4 mm to 1.2 mm and a maximum depth (depth at the deepest point) of 70% to 100% of the profile depth T SR ( Fig. 3 ) provided.

[0030] The further design of the grooves 3 formed further on the outer side of the running track is explained below using a single groove 3 as an example.

[0031] According to Fig. 2 The groove 3 at the periphery of the tread is bounded by two groove edges 7, 8 which run straight and parallel to each other in plan view - a groove edge 7 formed on the respective shoulder-side profile block 4 and a groove edge 8 formed on the respective semi-central profile block 5 - wherein the groove 3, viewed in plan view, has a groove centerline m R which follows the groove course and is spaced at the same intervals as the groove edges 7, 8 and furthermore runs straight, inclined opposite to the circumferential direction to the inclined grooves 1 and at an angle β of 20° to 40°, in particular of 25° to 35°, with respect to the groove centerline m R to the circumferential direction.The groove 3 has an inward groove end 9 located on one adjacent inclined groove 1, which enters the surface first when the tire rolls forward and is further towards the outside of the tread, and an outward groove end 10 located on the other adjacent inclined groove 1 and is further towards the inside of the tread. The groove end 9 points towards the tire equatorial plane (line AA, ) relative to the groove end 10. Fig. 1 ) a larger distance determined in the axial direction, relative to the respective end of the groove centerline m R. The groove 3 also has a constant width b R of 3.0 mm to 7.0 mm, in particular from 4.0 mm to 6.0 mm, determined in plan view perpendicular to the groove centerline m R and between the groove edges 7, 8, and a constant maximum depth t R (depth at the deepest point) determined in the radial direction. Fig. 3 ) of 65% to 100%, in particular of at least 70%, of the profile depth T SR ( Fig. 3 ) and - viewed from above and in each case with reference to a point PR lying in the middle on their groove centerline m R - to the nearest lateral edge of the ground contact surface ( Fig. 1 : right line L) a distance a R determined at the periphery of the tread in the axial direction ( Fig. 1 ) of 7% to 30%, in particular of 12% to 25%, preferably of 17% to 23%, of the width B ( Fig. 1 ) of the ground contact area. The depth t R ( Fig. 3 ) preferably is at most the profile depth T SR reduced by 1.0 mm, particularly preferably by 1.5 mm to 2.0 mm ( Fig. 3 ).

[0032] How Fig. 2 bis Fig. 4 especially in combination with each other, the groove 3 is defined by a groove wall 11 adjoining the groove edge 7, a groove wall 12 adjoining the groove edge 8 and a groove wall 12 visible in top view ( Fig. 2 ) extending diagonally through groove 3 and merging into diagonal grooves 1 ( Fig. 2, Fig. 3 ), forming the groove base, straight groove 13.

[0033] According to Fig. 3 The groove walls 11, 12 are positioned in the cross-section running perpendicular to the groove centerline m R in plan view (cf. position of line III-III in Fig. 2 ), each consisting of a radially outer flank surface 11a (groove wall 11), 12a (groove wall 12) adjoining the groove edge 7 (groove wall 11), 8 (groove wall 12) and a radially inner inclined surface 11b (groove wall 11), 12b (groove wall 12) extending to and sloping down to the groove base groove 13.

[0034] The radially outer flank surfaces 11a, 12a, viewed in the aforementioned cross-section, run straight and at a constant angle γ (flank surface 11a), δ (flank surface 12a) to the radial direction of 0° to 10°, in particular of 2° to 8°, wherein the angle γ is preferably 1° to 4° greater than the angle δ. The radially outer flank surfaces 11a, 12a adjoin the respective inclined surfaces 11b, 12b at a constant depth t1 in the radial direction of 60% to 75% of the maximum depth tR of the groove 3.

[0035] The radially inner inclined surfaces 11b, 12b appear, in any cross-section viewed perpendicular to the groove centerline mR in plan view, as straight lines which run at an angle ε (inclined surface 11b), η (inclined surface 12b) to the radial direction and have, in the aforementioned cross-section, a width bSF1 (inclined surface 11b), bSF2 (inclined surface 12b). The magnitude of the angles ε, η and the magnitude of the widths bSF1, bSF2 are specifically adapted to the design of the groove base 13. The design of the groove base 13 will be discussed first, followed by a discussion of the angles ε, η and the widths bSF1, bSF2.

[0036] According to Fig. 2 bis Fig. 4 The groove base 13 extends over its entire longitudinal extent as seen in plan view to the aforementioned maximum depth t R ( Fig. 3 ) of the groove 3. The groove base groove 13 has two limiting edges 13a at the radially inner ends of the inclined surfaces 11b, 12b, which - as Fig. 2 shows – viewed from above – straight and parallel to each other and – as in Fig. 3 especially in connection with Fig. 4 shows - at a constant distance (not specified) determined in the radial direction to the level of the profile depth T SR ( Fig. 3 ) and at a constant distance (not specified) determined in the radial direction to the level of the maximum depth t R ( Fig. 3 ). The groove base groove 13 also has a groove center line m RG ( which follows its course in plan view and is spaced at the same intervals as the boundary edges 13a. Fig. 2 ) which is inclined in the same direction as the groove centerline mR of the groove 3 with respect to the circumferential direction, and runs – with respect to the groove centerline mRG – at an angle θ to the circumferential direction, which is smaller than the aforementioned angle β of the groove 3. Preferably, the angle θ is 1° to 10°, preferably 3° to 5°, smaller than the angle β. The groove base 13 is bounded by a groove base 13b running between the inclined surfaces 11b, 12b, i.e., between the boundary edges 13a, which according to Fig. 3 , viewed in the cross-section running perpendicular to the groove centerline m RG in plan view (cf. position of line III-III in Fig. 2 ), U-shaped and symmetrical with respect to the groove centerline m RG ( Fig. 2 ) is executed and has a continuously curved mouth edge 13b' at each inclined groove 1 ( Fig. 4 ).

[0037] The groove base groove 13 also has a constant width b RG determined in plan view perpendicular to the groove center line m RG and between the boundary edges 13a ( Fig. 3 ) of 15% to 35%, in particular of 20% to 30%, of the width b R ( Fig. 2 ) the groove 3 and a constant depth t RG determined in the radial direction with respect to the boundary edges 13a ( Fig. 3 ) from 0.30 mm to 1.50 mm, preferably up to 1.00 mm, particularly preferably up to 0.75 mm.

[0038] How Fig. 2 bis Fig. 4 When they point towards each other, the angles ε, η change ( Fig. 3 ) and the widths b SF1 , b SF2 ( Fig. 3 ) their dimensions change continuously, in particular uniformly, along the longitudinal extent of the groove 3 as seen in plan view, and thus simultaneously along the longitudinal extent of the groove base groove 13 as seen in plan view, whereby the parameters belonging to the inclined surface 11b (angle ε, width b SF1 ) change in the opposite direction to the parameters belonging to the inclined surface 12b (angle η, width b SF2 ). The larger the respective angle ε, η, the larger the width b SF1 , b SF2 belonging to the same inclined surface 11b, 12b. The inclined surfaces 11b, 12b are therefore continuously twisting along their longitudinal extent and, with decreasing angles ε, η, continuously shortening surfaces in cross-section. At the incoming groove end 9 ( Fig. 2 , Fig. 4 ) the angle ε ( Fig. 3 ) its greatest value ( Fig. 2 , Fig. 4 ), the width b SF1 ( Fig. 3 ) their larger value, the angle η ( Fig. 3 ) its smallest value ( Fig. 2 , Fig. 4 ) and the width b SF2 ( Fig. 3 ) their smallest value ( Fig. 2 , Fig. 4 ) on. At the end of the groove 10 ( Fig. 2 , Fig. 4 ) the angle ε ( Fig. 3 ) its smallest value ( Fig. 2 , Fig. 4 ), the width b SF1 ( Fig. 3 ) their smallest value ( Fig. 2 , Fig. 4 ), the angle η ( Fig. 3 ) its greatest value ( Fig. 2 , Fig. 4 ) and the width b SF2 reaches its greatest value.

[0039] Preferably, the radially inner inclined surface 12b is designed such that the incoming groove end 9 ( Fig. 2 , Fig. 4 ) present smallest value of the angle η ( Fig. 3 ) with the constant angle δ ( Fig. 3 ) the radially outer flank surface 12a coincides, so that the radially inner inclined surface 12b and the radially outer flank surface 12a at the incoming groove end 9 ( Fig. 2 , Fig. 4 ) together from a kink-free, especially straight, mouth edge 9a ( Fig. 4 are limited.

[0040] Furthermore, it is preferred if the radially inner inclined surface 11b is designed such that the groove end 10 at the outgoing groove end ( Fig. 2 , Fig. 4 ) present smallest value of the angle ε ( Fig. 3 ) with the constant angle γ ( Fig. 3 ) the radially outer flank surface 11a coincides, so that the radially inner inclined surface 11b and the radially outer flank surface 11a at the tapered groove end 10 ( Fig. 2 , Fig. 4 ) together from a kink-free, in particular straight, mouth edge 10a ( Fig. 4 are limited.

[0041] Particularly preferably, the mouth edges 9a, 10a each connect tangentially to the respective mouth edge 13b' ( Fig. 4 ) of the groove base 13b of the groove base groove 13 at ( Fig. 4 , shown for mouth edge 9a).

[0042] The invention is not limited to the described embodiment.

[0043] The tread pattern does not need to be directional. The diagonal grooves can be curved or straight. At least one shoulder-side profile block row is provided, the shoulder-side profile blocks of which are bordered by grooves with corresponding inclined surfaces and groove base grooves.

[0044] The grooves that define the inner edges of the tread on the shoulder side separate the shoulder-side profile blocks from a profile block or a block-like positive profile structure. Preferably, the grooves separate each shoulder-side profile block from a semi-central profile block, as explained in the exemplary embodiment. In the area of ​​the tire's equatorial plane, one or more circumferential profile ribs can be provided instead of the central profile blocks.

[0045] The smallest value of the angles ε, η of the inclined surfaces 11b, 12b is at least the size of the angle γ, δ of the respective adjoining radially outer flank surface 11a, 12a. Reference symbol list

[0046] 1 Slanted groove 1a Inward groove section 1b Shoulder groove section 2 Groove 3 Groove 4 Shoulder profile block 4' Shoulder profile block row 5 Semi-central profile block 6 Central profile block 7 Groove edge 8 Groove edge 9 Inward groove end 9a End edge 10 Outward groove end 10a End edge 11 Groove wall 11a Radial outer flank surface 11b Radial inner inclined surface 12 Groove wall 12a Radial outer flank surface 12b Radial inner inclined surface 13 Groove base groove 13a Boundary edge 13b Groove base 13b' End edge A-A line (tire equatorial plane) a 1 , a R Distance B, b R , b RG , b SF1 , b SF2 , B SR Width h 1 Auxiliary line L (lateral edge of the ground contact area) m R , m RG , m SR Groove center line PR Point RParrow (rolling direction) S 4 Arrow (viewing direction) t1, t RG Depth t R maximum depth T SR Profile depth Z 2 Detail α, β, γ, δ, ε, η, θ Angle

Claims

1. Pneumatic vehicle tyre having a tread with at least one shoulder-side profile-block row (4') with shoulder-side profile blocks (4) which are separated from one another by oblique channels (1) extending parallel to one another in plan view and formed to a profile depth (TSR) and which, at the tread inner side, are in each case delimited by a channel (3) opening out into two circumferentially successive oblique channels (1) and, in plan view, extending in an inclined manner in the opposite direction to the oblique channels (1) in relation to the circumferential direction, wherein the channel (3) has a width (bR) of 3.0 mm to 7.0 mm, a maximum depth (tR) of 65% to 100% of the profile depth (TSR), channel walls (11, 12) proceeding from the tread periphery, and a channel-base channel (13) extending at its maximum depth (tR) and opening out into the oblique channels (1) and, in plan view, extending obliquely through the channel (3), characterized in that the channel walls (11, 12) of the channel (3), when seen in cross section, are, over the entire extent of the channel (3), made up in each case of a radially outer flank surface (11a, 12a), which extends at an angle (γ, δ) of 0° to 10° to the radial direction, and an oblique surface (11b, 12b), which adjoins said radially outer flank surface and extends to the channel-base channel (13) and descends in relation to the latter and extends at an angle (ε, η) to the radial direction, wherein the angle (ε) at which the oblique surface (11b) of one channel wall (11) extends and the angle (η) at which the oblique surface (12b) of the other channel wall (12) extends change in size continously, and oppositely in relation to one another, over the longitudinal extent of the channel (3), wherein the smallest value of the angle (ε, η) of each oblique surface (11b, 12b) is at least the size of the angle (γ, δ) of the radially outer flank surface (11a, 12a) that adjoins the respective oblique surface (11b, 12b).

2. Vehicle tyre according to Claim 1, characterized in that the channel (3) has a tread-outer-side channel end (9) and a tread-inner-side channel end (10), wherein the angle (ε) at which the oblique surface (11b) of the channel wall (11) formed on the respective shoulder-side profile block (4) extends has its greatest value at the tread-outer-side channel end (9).

3. Pneumatic vehicle tyre according to Claim 2, characterized in that the tread is of directional design, wherein the tread-outer-side channel end (9) is a leading channel end (9), which meets the ground first when the tyre rolls during forward travel (arrow R), and the tread-inner-side channel end (10) is a trailing channel end (10).

4. Pneumatic vehicle tyre according to one of Claims 1 to 3, characterized in that the channel-base channel (13), when seen in plan view, extends rectilinearly based on its channel midline (mRG).

5. Pneumatic vehicle tyre according to one of Claims 1 to 4, characterized in that the channel (3) and the channel-base channel (13), when seen in plan view, extend rectilinearly based on their channel midlines (mR, mRG), wherein the channel midline (mRG) of the channel-base channel (13) extends in an inclined manner in the same direction as the channel midline (mR) of the channel (3) in relation to the circumferential direction or in the circumferential direction.

6. Pneumatic vehicle tyre according to Claim 5, characterized in that, when seen in plan view and based on their channel midlines (mRG, mR), the channel-base channel (13) and the channel (3) in each case extend at an angle (β, θ) to the circumferential direction, wherein the angle (θ) at which the channel-base channel (13) extends in relation to the circumferential direction is smaller, in particular is smaller by 1° to 10°, preferably by 3° to 5°, than the angle (β) at which the channel (3) extends in relation to the circumferential direction.

7. Pneumatic vehicle tyre according to Claim 5 or 6, characterized in that the channel (3), when seen in plan view and based on its channel midline (mR), extends at an angle (β) of 20° to 40°, in particular of 25° to 35°, to the circumferential direction.

8. Pneumatic vehicle tyre according to one of Claims 1 to 7, characterized in that the sizes of the angles (ε, η) of the oblique surfaces (11b, 12b) change continuously, that is to say uniformly.

9. Pneumatic vehicle tyre according to one of Claims 1 to 8, characterized in that the channel-base channel (13), when seen in a cross section extending perpendicularly to its channel midline (mRG) in plan view, is delimited by a U-shaped channel base (13b) having in each case one mouth edge (13b') at each oblique channel (1), wherein preferably the channel walls (11, 12), at that point where the oblique surfaces (11b, 12b) have the smallest value of their angle (ε, η), are delimited by an in particular rectilinearly extending mouth edge (9a, 10a) which adjoins the mouth edge (13b') of the channel base ( 13b) without any kinks tangentially.

10. Pneumatic vehicle tyre according to one of Claims 1 to 9, characterized in that the respective largest values and the respective smallest values of the angles (ε, η) of the oblique surfaces (11b, 12b) correspond.

11. Pneumatic vehicle tyre according to one of Claims 1 to 10, characterized in that the channel-base channel (13) has at the radially inner ends of the oblique surfaces (11b, 12b) two delimitation edges (13a) extending rectilinearly in plan view and at a constant distance, determined in a radial direction, from the level of the profile depth (TSR).

12. Pneumatic vehicle tyre according to Claim 11, characterized in that the channel-base channel (13) has a constant width (bRG), determined perpendicularly to its channel midline (mRG) in plan view and between the delimitation edges (13a), of 15% to 35%, in particular of 20% to 30%, of the width (bR) of the channel (3).

13. Pneumatic vehicle tyre according to Claim 11 or 12, characterized in that the channel-base channel (13) has a constant depth (tRG), based on the delimitation edges (13a) and determined in the radial direction, of 0.30 mm to 1.50 mm, in particular of up to 1.00 mm, preferably of up to 0.75 mm.

14. Pneumatic vehicle tyre according to one of Claims 1 to 13, characterized in that the radially outer flank surfaces (11a, 12a) adjoin the oblique surfaces (11b, 12b) at a constant depth (t1), determined in the radial direction, of 60% to 75% of the maximum depth (tR) of the channel (3).

15. Pneumatic vehicle tyre according to one of Claims 1 to 14, characterized in that the channel (3) - when seen in plan view and in each case based on a point (PR) situated centrally on its channel midline (mR) - is at a distance (aR), determined axially on the tread periphery, of 7% to 30%, in particular of 12% to 25%, preferably of 17% to 23%, of the width (B) of the ground contact area of the tread from the nearest lateral boundary of the ground contact area (line L).