Vehicle tires

Abstract

The invention relates to a vehicle tire with a tread, wherein the tread has at least one circumferentially extending row of profile blocks, wherein the at least one row of profile blocks is subdivided into several profile blocks (6a) by transverse grooves (8), wherein the transverse grooves (8) extend at least partially at an angle to a transverse direction (Q) and at least some of the transverse grooves (8) are formed by shoulder-side transverse grooves (8) whose outer end (8b) is open towards a tire shoulder (S) of the vehicle tire, wherein the shoulder-side transverse grooves (8) are oriented at least partially in a defined direction of travel (L) of the vehicle tire. According to the invention, it is provided that in at least one of the shoulder-side transverse grooves (8) a trough-like depression (11) is formed in a central area (10a) and the central area (10a) of the respective shoulder-side transverse groove (8) transitions via a bend (14) into an outer area (10b) of the tire.

Description

[0001] The invention relates to a vehicle tire according to the preamble of claim 1.

[0002] Vehicle tires, especially pneumatic tires, conventionally have circumferentially extending rows of tread blocks, which may be separated from each other by several circumferentially extending grooves (central circumferential grooves, shoulder-side circumferential grooves). V-shaped or angled transverse grooves, for example, open into the circumferential grooves, which further subdivide the rows of tread blocks into individual tread blocks. This creates a specific tire pattern.

[0003] For a tire's good snow performance, snow-to-snow friction is particularly important, i.e., the friction between the snow trapped in the tire's tread pattern and the snow layer on the road. Therefore, it is advantageous to retain the snow collected from the road to a certain extent within the tire's tread pattern. This is usually achieved effectively with V-shaped, angled transverse grooves oriented opposite the tire's direction of travel (forward travel). Additional measures to retain the snow can be implemented.

[0004] For example, DE 10 2019 217 439 A1 describes the arrangement of base elevations (elevations, "tie-bar") of varying depth or height in the transverse grooves, which locally reduce the groove depth of the transverse grooves. In the individual base elevation sections, two grooves separated from each other by a web are formed on a cover surface parallel to each other and arranged at a corresponding distance from the groove flanks of the respective transverse groove. The grooves serve as additional snow pockets and provide additional grip edges. When driving on snow or slush, snow can be pressed into the grooves and compacted, thereby achieving improved traction properties. Additional depressions extending in the circumferential direction and adjacent to the base elevation sections form additional snow pockets to improve the effect of snow-on-snow friction.

[0005] US 11,161,375 B2 provides a connecting bar with a sipe-like cut, which is located only in the central region of the transverse grooves that lead into one of the central circumferential grooves. In the transverse grooves that lead into one of the shoulder-side circumferential grooves, the connecting bar with the sipe-like cut can also be located in an end region of the respective transverse groove adjacent to the shoulder-side circumferential groove. The sipe-like cut connecting bars in the transverse grooves, in conjunction with other specially arranged sipe-like cuts in the tread blocks, maintain a good balance between steering stability on dry roads and, at the same time, handling on snow and ice.

[0006] In a typical V-shaped tire tread pattern, where the transverse grooves are oriented in the tire's direction of travel and open toward the tire shoulder, snow cannot be held in the tire shoulder. Instead, the snow slides outward from the tire tread pattern as the tire rotates, keeping snow-to-snow friction at a low level.

[0007] DE 10 2015 214 483 A1 further describes a vehicle tire with a shoulder-side tread block row defined on the inside of the tread by a shoulder-side circumferential groove. Transverse grooves extending essentially parallel to one another open into the shoulder-side circumferential groove, with each of these transverse grooves defined by a groove base and two groove flanks. Each of these transverse grooves has at least two adjacent groove sections of different depths within the ground contact area, with the depth of the groove sections gradually increasing toward the tread edge. This is intended to reduce air pumping noises that occur in the shoulder-side areas of the tread due to air being forced through the transverse grooves.

[0008] DE 10 2005 013 810 A1 describes a vehicle tire having a connecting web in each of the transverse grooves that open into shoulder-side circumferential grooves, said connecting web connecting or binding adjacent shoulder-side tread blocks of the vehicle tire in the circumferential direction via the respective transverse groove. A sipe with a zigzag section is formed in the connecting web, extending in the groove center direction of the respective transverse groove. The sipe is three-dimensional, with sipe wall surfaces repeatedly having three-dimensional recesses and protrusions. Because the recessed sections and protrusions can engage with each other, a high resistance force can be achieved in the shoulder region of the tread not only against the force in the circumferential direction, but also against the lateral force.This makes it possible to efficiently suppress the movement of the connecting web, especially the movement in the lateral direction, which can minimize the generation of deformations at the cut bottom in the highly stressed shoulder area and prevent the occurrence of cracks from the cut bottom.

[0009] The following invention is based on the object of providing a vehicle tire with which good snow performance can be provided in a simple manner.

[0010] This problem is solved by a vehicle tire according to the independent claim. The subclaims specify preferred developments.

[0011] Accordingly, a vehicle tire is provided with a tread, the tread having at least one row of profile blocks running in the circumferential direction, the at least one row of profile blocks being divided into a plurality of profile blocks by transverse grooves, the transverse grooves running at least partially at an angle to a transverse direction and at least some of the transverse grooves being formed by shoulder-side transverse grooves whose end on the outside of the tire is open towards a tire shoulder of the vehicle tire, the shoulder-side transverse grooves being oriented at least partially in a fixed running direction of the vehicle tire, and in at least one of the shoulder-side transverse grooves a trough-like depression is formed in a central region and the central region of the respective shoulder-side transverse groove merges into a region on the outside of the tire via a kink.Preferably, the tire outer side end is arranged in the tire outer side region, so that the shoulder-side transverse groove in the tire outer side region is open towards the tire shoulder of the vehicle tire.

[0012] The invention improves snow-on-snow friction, thereby enabling good snow performance, particularly with V-profile tires that have an open tire shoulder. This results from the fact that additional snow can be trapped in the trough-like depression and better retained in the shoulder-side transverse groove, even when this shoulder-side transverse groove is oriented in the direction of travel. Orientation in the direction of travel means that the transverse groove is angled relative to the transverse direction such that it extends inward from the tire shoulder in the direction of travel. The additional flanks of the trough-like depression prevent the snow from slipping or sliding out of the shoulder-side transverse groove over the open outer end of the tire.

[0013] Furthermore, snow trapped in the shoulder-side transverse groove, which cannot be held by the trough-like depression alone during tire operation, can be additionally blocked in the axial direction or further outward in the transverse direction by the kink, thus preventing it to a certain extent from sliding out of the open outer end of the tire or the transverse groove. The trough-like depression and the kink thus act "one after the other" in the axial direction or transverse direction to effectively prevent snow from sliding out and thus improve snow-to-snow friction.

[0014] Preferably, the bend is further provided for the trough-like depression. This allows the additional blocking to act immediately after the trough-like depression, allowing both to interact effectively.

[0015] Preferably, the bend and preferably also the trough-like depression are located within a tire contact patch of the tread, with the bend preferably being located at a maximum distance of 8 mm from a boundary of the tire contact patch. This prevents snow from sliding out to the side of the vehicle tire, i.e., in an upwardly curved area next to the tire contact patch, and can also be effectively retained in the trough-like depression below the tire contact patch.

[0016] Preferably, it is further provided that a tangent angle of a groove tangent, which bears tangentially against one of the groove flanks of the respective shoulder-side transverse groove, changes, preferably abruptly, between the central region and the tire-outer region across the kick by an amount of between 10° and 20°, preferably 15°. This change in angle creates a sufficiently abrupt bend, through which the snow can be effectively held in the shoulder-side transverse groove or prevented from sliding out.

[0017] Preferably, the central region of the shoulder-side transverse groove is oriented at an angle to the transverse direction, in the running direction, and the tire-outside region of the shoulder-side transverse groove is oriented substantially in the transverse direction. As a result, fewer forces act in the running direction of the vehicle tire in the outer region, and snow can be better retained therein. In addition, the bend can be optimally formed.

[0018] Preferably, the trough-like depression is formed by at least two flanks and at least one depression part, wherein the flanks adjoin the depression part on both sides in the extension direction of the respective shoulder-side transverse groove, and the flanks have a flank angle such that the at least one depression part is lowered over the flanks. Thus, at least one depression is provided, which is bordered on both sides by angled flanks, thereby ensuring effective snow retention. This can be optimized by ensuring that the flank angle is at least 10°, preferably 15° to 25°. At these angles, the snow can be effectively prevented from sliding out.

[0019] Preferably, the trough-like depression has a first depression part at a first groove depth, a second depression part at a second groove depth, and a third depression part at a third groove depth, wherein the depression parts merge into one another in the transverse direction across the flanks. Accordingly, more than one depression part with correspondingly angled flanks can also be provided, wherein the first groove depth preferably corresponds to the third groove depth and the second groove depth is greater than the first groove depth, and the third groove depth and the second groove depth preferably correspond to a full profile depth of the tread. Thus, a depression is formed on two levels in order to hold the snow even more effectively in the shoulder-side transverse groove.

[0020] Preferably, the first groove depth, the second groove depth, and the third groove depth are greater than a base depth of the shoulder-side transverse groove, wherein a groove base of the shoulder-side transverse groove extends at least partially along the base depth in the direction of extension next to the trough-like depression, and the base depth corresponds to between 60% and 100%, preferably between 70% and 90%, of the full profile depth of the tread. The depression thus originates from the base depth, which shifts the groove base downward in two planes, although more than two planes are also possible.

[0021] In the context of the invention, "central side" or "tread inside" means that the respective element on the respective component is oriented toward the equatorial plane, inward, or toward the central circumferential groove. "Shoulder side" or "tread outside" accordingly means an orientation facing outward toward the outside of the tread or toward a tire shoulder of the vehicle tire.

[0022] The drawings show: Fig. 1 a section of a tire profile of a vehicle tire; Fig. 2 a detailed view of a tire shoulder of the vehicle tire according to Fig. 1; and Fig. 3 a sectional view along one of the shoulder-side transverse grooves according to Fig. 2.

[0023] Fig. 1 schematically shows a section of a tread 1 of a vehicle tire 2, in particular a pneumatic vehicle tire, wherein only one tread half is shown. The tread half, not shown, has a comparable structure, preferably mirror-symmetrical thereto. The tire profile of the tread 1 shown is formed by providing a central circumferential groove 3 along the equatorial plane C of the vehicle tire 1, which is linear in plan view and runs in the circumferential direction U. Alternatively, two central circumferential grooves (not shown) can also be provided, which are parallel and spaced from one another adjacent to the equatorial plane C. Adjacent to this central circumferential groove(s) 3 in the transverse direction Q is a central tread block row 4, which is delimited on its other side by a shoulder-side circumferential groove 5. Adjacent to the shoulder-side circumferential groove 5 is a shoulder-side tread block row 6.

[0024] Between the central circumferential groove 3 and the shoulder-side circumferential groove 5, central transverse grooves 7 run parallel to one another, dividing the central tread block row 4 into central tread blocks 4a. The central transverse grooves 7 open with their central ends 7a into the central circumferential groove 3 and with their shoulder-side ends 7b into the shoulder-side circumferential groove 5. The central transverse grooves 7 run in the transverse direction Q in a V-shape or at an angle between the two circumferential grooves 3, 5. In a similar manner, the shoulder-side tread block row 6 is divided into shoulder-side tread blocks 6a by shoulder-side transverse grooves 8, wherein the shoulder-side transverse grooves 8 open with their tire-inside ends 8a into the shoulder-side circumferential groove 5 and their tire-outside ends 8b are open towards the tire shoulder S, as in Fig. 2 shown.

[0025] The shoulder-side transverse grooves 8 run from the shoulder-side circumferential groove 5 in the transverse direction Q, also in a V-shape or angled towards the tire shoulder S or the tread outer side, wherein the shoulder-side transverse grooves 8 in the illustrated embodiment are angled less strongly relative to the transverse direction Q than the middle transverse grooves 7. For the middle transverse grooves 7, for example, an angle of 30° to 55°, in particular of at least 45°, can be provided and for the shoulder-side transverse grooves 7 of between 5° and 20°.

[0026] The vehicle tire 1 is a directional vehicle tire 1, i.e., it has a preferred (forward) running direction L in which the vehicle tire 1 rolls during (forward) travel. The central transverse grooves 7 and the shoulder-side transverse grooves 8 are oriented in this running direction L of the vehicle tire 1, i.e., they are angled such that they extend from the tire shoulder S in the running direction L.

[0027] In principle, it would also be possible for the tread 1 to have no circumferential grooves (or no central circumferential grooves 3) (not shown), and for the tread 1 to therefore be composed of tread block rows P running in the circumferential direction U, which are divided into individual tread blocks PB by transverse grooves R angled relative to the transverse direction Q and in the running direction L, i.e. at least shoulder-side transverse grooves 8. The following description is based on the shoulder-side transverse grooves R; 8 with circumferential grooves 3, 5, as described, but is transferable accordingly to a tread 1 without (central) circumferential grooves 3, 5.

[0028] The shoulder-side transverse grooves 8 are defined by two groove flanks 9a, 9b and a groove base 9c, which form a substantially U-shaped profile, whereby the groove flanks 9a, 9b may also be slightly tilted relative to the vertical. The groove base 9c of the respective shoulder-side transverse groove 8 is stepped in a central region 10a of the shoulder-side transverse groove 8 in the extension direction E of the shoulder-side transverse groove 8, as shown in the detailed view in Fig. 2 and the elevation profile in Fig. 3. This creates a trough-like depression 11 locally in the central region 10a of the shoulder-side transverse groove 8.

[0029] Accordingly, the groove base 9c runs deeper in the area of ​​the trough-like depression 11, i.e. the shoulder-side transverse groove 8 has a locally increased groove depth T (depth from a surface 6b of the shoulder-side tread block 6a to the groove base 9c) with respect to a base depth T0. The groove depth T of the shoulder-side transverse groove 8 is equal to the base depth T0 in an area next to the trough-like depression 11, i.e., for example, in an inner tire area 10c of the shoulder-side transverse groove 8, wherein the shoulder-side transverse groove 8 preferably also opens into the shoulder-side circumferential groove 5 at approximately this base depth T0. There may also be further elevations or depressions compared to the base depth T0 within the shoulder-side transverse groove 8.

[0030] In the illustrated embodiment, the base depth T0 is not at the so-called full tread depth T*, which is normally present at the deepest point in the circumferential grooves 3, 5 of the tread 1. As shown, the deepest point of the trough-like depression 11 is at the full tread depth T*, so that the groove depth T of the shoulder-side transverse groove 8 in the area of ​​the trough-like depression 11 varies between the base depth T0 and the full tread depth T*.

[0031] The groove bottom 9c runs as in Fig. 3, starting from the shoulder-side circumferential groove 5, which lies at the full tread depth T* (depth from the surface 6b of the shoulder-side tread block 6a to the groove base of the shoulder-side circumferential groove 5), initially in the tire-inside region 10c at the base depth T0. Subsequently, the groove base 9c in the central region 10a transitions in a step-like manner over a sloping first flank 12a into a first recessed part 13a designed as a plateau, which lies at a first groove depth Ta that is greater than the base depth T0 but less than the full tread depth T*. Subsequently, the groove base 9c continues in a step-like manner over a sloping second flank 12b into a second recessed part 13b, also designed as a plateau. The second recessed part 13b lies at a second groove depth Tb, which in the illustrated embodiment corresponds to the full tread depth T*.

[0032] After the second recessed portion 13b, which in this case forms the bottom of the trough-like recess 11, the groove base 9c transitions in a stepwise manner via a rising third flank 12c into a third recessed portion 13c designed as a plateau, which lies at a third groove depth Tc, which in this case corresponds to the first groove depth Ta. However, the third groove depth Tc can also be selected differently. Via a fourth flank 12d, the groove base 9c then transitions in a stepwise manner back to the base depth T0, and the shoulder-side transverse groove 8 transitions into a tire-outside region 10b, which then ends open (tire-outside end 8b).

[0033] Since the transition between the central region 10a and the tire-outside region 10b of the shoulder-side transverse groove 8 is fluid, the trough-like depression 11 can also protrude into the tire-outside region 10b, i.e., extend even further in the transverse direction Q toward the tire shoulder S. The groove base 9c can also be further subdivided into steps and thus have several depression parts 13 and intermediate flanks 12. However, it is advantageous if the trough-like depression 11 lies within a tire contact patch 1A of the tire 1.

[0034] In this trough-like depression 11, additional snow can be trapped and better retained in the shoulder-side transverse groove 8, even if this shoulder-side transverse groove 8 is oriented in the running direction L. The additional flanks 12 prevent the snow from slipping or sliding out of the shoulder-side transverse groove 8 over the open tire outer end 8b, so that the snow-to-snow friction can be improved overall. The flank angle ω of the respective flanks 12 can, for example, be at least 10°, preferably between 15° and 25°, relative to the transverse direction Q.

[0035] In addition, it is provided that the shoulder-side transverse groove 8 has a kink 14 or a sharp bend between the central region 10a and the tire outer region 10b, for example in the transverse direction Q directly adjacent to the trough-like depression 11 (depending on the axial extent). This kink 14 is in Fig. 2 by the dotted lines, which represent straight continuations of the groove flanks 9a, 9b or groove tangents 8T, which lie tangentially on the groove flanks 9a of the shoulder-side transverse grooves 8 on both sides of the kick 14. A tangent angle αT of the groove tangent 8T changes between the central region 10a and the tire-outside region 10b via the kick 14 by an amount of between 10° and 20°, preferably 15°, ie there is an abrupt change in the tangent angle αT of the groove tangent 8T.

[0036] Snow trapped in the shoulder-side transverse groove 8, which cannot be held by the trough-like depression 11 during operation of the vehicle tire 1, is then additionally blocked further outward in the axial direction or in the transverse direction Q by the kink 14 and is thus prevented to a certain extent from sliding out of the open outer tire end 8b. The trough-like depression 11 and the kink 14 therefore act "one after the other" in the axial direction or in the transverse direction Q to even more effectively prevent snow from sliding out and thus improve snow-to-snow friction. For this purpose, the kink 14 is also located within the tire contact area 1A of the tread 1, preferably at a distance A of a maximum of 8 mm in front of a boundary 1G of the tire contact area 1A. As a result, the snow cannot slide out of the shoulder-side transverse groove 8 in the upwardly curved area to the side of the tread 1. List of reference symbols 1 tread 1A tire contact patch 1G Limit of the tire contact patch 1A 2 vehicle tires 3 central circumferential groove 4 middle tread block row 4a middle profile block 5 shoulder-side circumferential groove 6 shoulder-side profile block row 6a shoulder-side profile block 6b Surface of the shoulder-side profile block 7 middle transverse groove 7a central end of the middle transverse groove 7 7b shoulder-side end of the middle transverse groove 7 8 shoulder-side transverse grooves 8a tire inside end of the shoulder-side transverse groove 8 8b tire outer end of the shoulder-side transverse groove 8 8T Groove tangent of the shoulder-side transverse groove 8 9a, 9b Groove flanks of the shoulder-side transverse groove 8 9c Groove base of the shoulder-side transverse groove 8 10a central area of ​​the shoulder-side transverse groove 8 10b tire outer side area of ​​the shoulder-side transverse groove 8 10c tire inside area of ​​the shoulder-side transverse groove 8 11 tub-like depression 12 Flank of the trough-like depression 12a first flank 12b second flank 12c third flank 12d fourth flank 13 Advanced section 13a first in-depth section 13b second part of the study 13c third in-depth section 14 bend A distance αT Tangent angle of the groove tangent 8T C Equatorial plane E Direction of extension of the transverse groove R; 8 L Running direction P tread block row PB profile block Q transverse direction R transverse groove S tire shoulder T Groove depth of the transverse groove R; 8 T* full tread depth of the vehicle tire 1 T0 Base depth of the transverse groove R, 8 Ta first groove depth Tb second groove depth Tc third groove depth U circumferential direction ω flank angle 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 2019 217 439 A1

[0004] US 11,161,375 B2

[0005] DE 10 2015 214 483 A1

[0007] DE 10 2005 013 810 A1

[0008]

Claims

[1] Vehicle tire (2) with a tread (1), wherein the tread (1) has at least one row of profile blocks (P; 4, 6) running in the circumferential direction (U), wherein the at least one row of profile blocks (P; 4, 6) is divided into a plurality of profile blocks (PB; 4a, 6a) by transverse grooves (R, 7, 8), wherein the transverse grooves (R, 7, 8) run at least partially at an angle to a transverse direction (Q) and at least some of the transverse grooves (R; 7, 8) are formed by shoulder-side transverse grooves (8), the end (8b) of which on the outer side of the tire is open towards a tire shoulder (S) of the vehicle tire (1), wherein the shoulder-side transverse grooves (8) are at least partially oriented in a fixed running direction (L) of the vehicle tire (1), characterized byin that in at least one of the shoulder-side transverse grooves (8) in a central region (10a) a trough-like depression (11) is formed and the central region (10a) of the respective shoulder-side transverse groove (8) merges into a tire-outer region (10b) via a kink (14). [2] Vehicle tyre (2) according to claim 1, characterized by that the tire outer side end (8b) is arranged in the tire outer side region (10b) so that the shoulder-side transverse groove (8) in the tire outer side region (10b) is open towards the tire shoulder (S) of the vehicle tire (1). [3] Vehicle tyre (2) according to claim 1 or 2, characterized by that the bend (14) adjoins the trough-like depression (11). [4] Vehicle tyre (2) according to one of the preceding claims, characterized bythat the kink (14) lies within a tire contact patch (1A) of the tread (1), preferably at a distance (A) of a maximum of 8 mm in front of a boundary (1G) of the tire contact patch (1A). [5] Vehicle tyre (2) according to one of the preceding claims, characterized by that a tangent angle (αT) of a groove tangent (8T), which lies tangentially on one of the groove flanks (9a, 9b) of the respective shoulder-side transverse groove (8), changes between the central region (10a) and the tire-outside region (10b) via the kick (14) by an amount of between 10° and 20°, preferably 15°. [6] Vehicle tyre (2) according to one of the preceding claims, characterized by that the central region (10a) of the shoulder-side transverse groove (8) is oriented at an angle to the transverse direction (Q) in the running direction (L) and the tire-outside region (10b) of the shoulder-side transverse groove (8) is aligned substantially in the transverse direction (Q). [7] Vehicle tyre (2) according to one of the preceding claims, characterized by in that the trough-like depression (11) is formed by at least two flanks (12) and at least one depression part (13), wherein the flanks (12) adjoin the depression part (13) on both sides in the extension direction (E) of the respective shoulder-side transverse groove (8) and the flanks (12) have a flank angle (ω) such that the at least one depression part (13) is lowered over the flanks (12). [8] Vehicle tyre (2) according to claim 7, characterized by that the flank angle (ω) is at least 10°, preferably 15° to 25°. [9] Vehicle tyre (2) according to claim 7 or 8, characterized byin that the trough-like depression (11) has a first depression part (13a) at a first groove depth (Ta), a second depression part (13b) at a second groove depth (Tb) and a third depression part (13c) at a third groove depth (Tc), wherein the depression parts (13; 13a, 13b, 13c) merge into one another in the transverse direction (Q) via the flanks (12). [10] Vehicle tyre (2) according to claim 9, characterized by that the first groove depth (Ta) corresponds to the third groove depth (Tc) and the second groove depth (Tb) is greater than the first groove depth (Ta) and the third groove depth (Tc). [11] Vehicle tyre (2) according to claim 9 or 10, characterized by that the second groove depth (Tb) is equal to a full profile depth (T*) of the tread (1). [12] Vehicle tyre (2) according to one of claims 9 to 11, characterized bythat the first groove depth (Ta), the second groove depth (Tb) and the third groove depth (Tc) are greater than a base depth (T0) of the shoulder-side transverse groove (8), wherein a groove bottom (9c) of the shoulder-side transverse groove (8) runs in the direction of extension (E) next to the trough-like depression (11) at least in regions on the base depth (T0). [13] Vehicle tyre (2) according to claim 12, characterized by that the base depth (T0) corresponds to between 60% and 100%, preferably between 70% and 90%, of the full profile depth (T*) of the tread (1).

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