Pneumatic vehicle tires

Abstract

The present invention relates to a pneumatic vehicle tire, comprising a directional tread having a tread bar (4, 5, 6) or tread bar-shaped profile structure having at least two grooves (7, 8) extending parallel in a top view, wherein the grooves have a width of 0.40 mm to 1.00 mm and include at least radially inward and adjacent radially outward portions (9a, 9b; 9'a, 9'b) extending from the groove base within central groove portions (7a, 8a) located along their longitudinal extensions within the tread bars (4, 5, 6) or bar-shaped profile structure. Within the tread are provided tread bars (4, 5, 6) or bar-shaped profile structures (6) including at least one pair of grooves extending adjacent to each other, the radially inner portions (9a, 9'a) extending radially, and the radially outer portions (9b, 9'b) in each case starting from their radially inner ends and inclined radially toward the leading edge portions (4a, 5a, 6a).

Description

Technical Field

[0001] The present invention relates to a pneumatic vehicle tire having a directional tread with a profile block or a block-shaped profile structure having a leading edge that first enters the contact patch during rotation of the tire during forward travel and a trailing edge that faces these leading edges in the periphery of the tread in the case of grooves such as transverse grooves or diagonal grooves. The tire has at least two sipes that extend parallel to each other in a plan view. Each sipe has a width of 0.40 mm to 1.00 mm and, within a central sipe portion that exists along its longitudinal range within the profile block or block-shaped profile structure, has a radially inner portion starting from the sipe base and an adjacent radially outer portion, and the radially outer portion extends at an angle of 5° to 35° with respect to the radial direction.

Background Art

[0002] This type of pneumatic vehicle tire is known, for example, from WO 2017 / 213230 A1 pamphlet. The tread of this tire has profile blocks each having several sipes that extend axially and each consist of two sipe portions starting from the sipe base in the radial direction and inclined with respect to the radial direction, and their inclination angles with respect to the tread periphery are opposite. Each profile block has at least four sipes that have correspondingly inclined sipe portions or are designed such that the bend between the two sipe portions in the first half of the sipe faces the bend between the sipe portions in the second half of the sipe.

[0003] A tire having a tread with such profile blocks is intended to have particularly good ice performance and can be easily demolded after vulcanization in a vulcanization mold.

[0004] Further pneumatic vehicle tires having a tread having a profile block with sipes, wherein the tread has two radially adjacent portions that enclose each other at an obtuse angle, one of which is a portion that extends radially from the base of the sipe, and the second portion is adjacent to the first portion and extends radially at an acute angle in the direction of the tread periphery, are known from German Patent Application Publication No. 102019206591A1 and German Patent Application Publication No. 102019206592A1. A tire having a tread having a profile block with sipes configured in this way is intended to have good snow performance, particularly with respect to water surface flattening characteristics and braking characteristics on dry roads.

[0005] Sipes with radially outward portions that run at an acute angle to the radial direction within the area surrounding the tread improve snow grip and braking performance on dry roads due to the engagement angle present around the tread, and reduce the rotational effect at the relevant sipe edges on the profile surface. Furthermore, wear is reduced due to the reduced snap-out effect under traction. Such sipes have different effects depending on the local stiffness of the individual block segments formed by them. In particular, in pneumatic vehicle tires with directional tread profiles, different wear patterns can occur on the block segments, which can lead to undesirable noise phenomena, such as the formation of sawtooth patterns. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2017 / 213230A1 Pamphlet [Patent Document 2] German Patent Application Publication No. 102019206591A1 Specification [Patent Document 3] German Patent Application Publication No. 102019206592A1 Specification [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Therefore, the present invention aims to further ensure the aforementioned positive effects of sipes in the first described type of pneumatic vehicle tire having a directional tread profile, as locally different wear of block segments needs to be prevented in order to avoid undesirable noise phenomena, particularly specific audible frequencies in rotational noise. [Means for solving the problem]

[0008] According to the present invention, the set objective is that a profile block or block-shaped profile structure exists in the tread having at least one pair of sipes running adjacent to each other, wherein the radially inner portion runs radially, and the radially outer portion, in each case, starts from their radially inner ends and slopes radially toward the leading edge, and in the sipes located closer to the leading edge, the radially outer portion surrounds an angle with respect to the radius that is at least 3°, particularly at least 5°, greater than the radially outer portion of the other sipes.

[0009] The present invention makes it possible to equalize the wear of the sipes on the block segments formed by the sipes on the profile blocks or segments of a block-shaped profile structure, particularly by having different inclinations on the radially outer portions of the sipes and inclinations on these portions in the same direction relative to the leading edge. As a result, undesirable noise phenomena in rotational noise can also be largely avoided. Advantageously, as a result of these means, the tire can respond particularly well to lateral forces during lane changes or cornering.

[0010] In a preferred embodiment of the present invention, a pair of sipes is, in each case, the only sipe within a profile block or block-like profile structure of the tread. In a directional tread, the circumferential and lateral stiffness of individual block segments can be particularly advantageous in certain tread regions, for example, the central tread region having two sipes in a profile block or block-like profile structure, with respect to supporting uniform wear or achieving precise force transmission of steering forces.

[0011] In a further advantageous embodiment, in at least each case, additional sipes are present within the profile block or block-shaped profile structure, each having a radially extending radially inner portion and, in each case, a radially outer portion that starts from the radially inner end and extends radially inclined toward the leading edge.

[0012] In this case, the profile block or block-like structure may be present within the tread, and the block or structure may have further sipes that are located closer to the leading edge, in which case the radially outer portion of the further sipes extends at an angle with respect to the radius that is at least corresponding to the angle of the radially outer portion of the pair of sipes with respect to the radial direction, and is close to the leading edge.

[0013] In a further advantageous embodiment, if a profile block or block-shaped profile structure is present in the tread having at least one additional sipe located closer to the trailing edge, it is advantageous that the radially outer portion of the additional sipe extends at an angle with respect to the radial direction that corresponds to a certain angle of the radially outer portion of the pair of sipes that is closer to the trailing edge.

[0014] Therefore, additional sipes are advantageously formed to support uniform wear of the profile blocks or block-shaped profile structures in the directional configuration of the tread.

[0015] In the case of three or more sipes in a profile block or block-shaped profile structure, sipes that do not have radially inclined outer portions may also extend particularly adjacent to the trailing edge.

[0016] In tread configurations having profile blocks or block-shaped profile structures with relatively large circumferences, it is advantageous that modified embodiments with up to three additional sipes are possible.

[0017] This can be particularly advantageous for uniform wear of the profile blocks or block-shaped profile structures within the tread, especially when the angle of the radially outward portion from sipe to sipe, starting from the radially outward portion of a sipe adjacent to the leading edge, decreases towards the trailing edge.

[0018] In a sipe having an outer portion that extends radially inclined for the purpose of equalizing wear, each of these portions is at an angle in the range of 5° to 25° with respect to the radial direction, and in a preferred embodiment, the angle of the radially outer portion in the sipe located closest to or adjacent to the leading edge is 15° to 23°, particularly 17° to 23°, preferably 20°, and the angle of the radially outer portion in the sipe located closest to or adjacent to the trailing edge is 7° to 13°, particularly 10°.

[0019] It is particularly effective for the radially outer portion within each sipe, determined from the periphery of the tread, to extend to a depth of 1.50 mm to 3.50 mm, especially 2.00 mm to 3.50 mm, and preferably 2.50 mm to 3.50 mm.

[0020] Typically, the sipes running within the profile block or block-shaped profile structure open into a groove at least at one of their ends. In particular, in the region of the opening into the groove, it is advantageous if the sipes each have an edge portion that is determined from the tread periphery and that in each case extends to a depth lower than the depth of the central sipe portion. The edge portions can extend to different depths and in a preferred embodiment, they extend from the tread periphery and extend to a depth of 10% to 50% of the profile depth.

[0021] In a further embodiment, the sipes each have a transition portion that starts from the tread periphery and extends radially and extends to a depth of 0.20 mm to 0.50 mm. These very shallow transition portions are formed by corresponding portions on the metal blades that form the sipes during the vulcanization of the tire in the vulcanization mold, and these blade portions are used to release the tread in a specific clean manner and without tearing after vulcanization in the region of the sipes.

[0022] Next, further features, advantages and details of the present invention will be described in more detail with reference to schematic and simplified drawings showing exemplary embodiments of the present invention.

Brief Description of the Drawings

[0023] [Figure 1] A plan view of the details of the circumferential portion of the tread of a pneumatic vehicle tire according to a variant of an embodiment of the present invention is shown. [Figure 2] An enlarged cross-sectional view taken along line II-II of FIG. 1 is shown. [Figure 3] An enlarged cross-sectional view taken along line III-III of FIG. 1 is shown. [Figure 4] Visualization (subtraction solid) of the sipe portion is shown. [Figure 5] Visualization (subtraction solid) of the sipe portion is shown.

Modes for Carrying Out the Invention

[0024] The pneumatic vehicle tire designed according to the present invention is a tire for automobiles, particularly for multi-track vehicles, and is preferably a radial design tire for automobiles, vans, SUVs, or light trucks (with a maximum permissible weight ≤ 7.5 t).

[0025] Figure 1 shows a plan view of the circumferential portion of the tread belonging to a pneumatic vehicle tire with a directional profile, so that the pneumatic vehicle tire is mounted on the vehicle so that it has a rotational direction indicated by arrow R during forward driving. Line AA represents the tire equator, and the two side edges of the tread's contact area are indicated by lines L, respectively.

[0026] In the illustrated embodiment, the tread has oblique grooves 1 in each half of the tread, extending parallel to each other in a plan view, with a slight curvature in part, starting from the region of the tire equatorial plane AA, extending beyond the side edge L, extending in a generally V-shape overall, and extending circumferentially offset from each other within the tread half across the width of the tread. The oblique grooves 1 are the main (discharge) grooves of the tread, preferably configured with a profile depth, particularly 6.0 mm to 9.5 mm, over most of their range. The term profile depth usually refers to the depth of the deepest main groove in a new tire.

[0027] Each end of an oblique groove 1 extending inward from the tread opens into an oblique groove 1 that extends to the other half of the tread. Between adjacent oblique grooves 1 in the circumferential direction, in each case, are two connecting grooves 2 and 3 that are inclined circumferentially in the opposite direction to the oblique groove 1 and have a depth of approximately 30% to 70% of the profile depth. Each connecting groove 3 extends at an acute angle of 5° to 15° with respect to the circumferential direction, and the connecting groove 3' extends at an angle of 30° to 45°.

[0028] Together with connecting grooves 3 and 3', the oblique groove 1 divides the tread into a central profile block 4, a semi-central profile block 5, and a shoulder-side profile block 6. In the plan view, the oblique groove 1 extends particularly at an angle of 30° to 50° with respect to the axial direction in the areas of the central profile block 4 and the semi-central profile block 5, and at an angle of 0° to 20° with respect to the axial direction in the area of ​​the shoulder-side profile block 6. In an alternative embodiment, for example, the central and semi-central profile blocks are connected to form a block-like profile structure.

[0029] Each profile block 4, 5, and 6 has a leading edge portion 4a, 5a, and 6a formed on one adjacent oblique groove 1 around the tread, and a trailing edge portion 4b, 5b, and 6b formed on the other adjacent oblique groove 1. The leading edges 4a, 5a, and 6a of blocks 4, 5, and 6 are the block edges that first enter the contact patch during tire rotation while moving forward (arrow R).

[0030] Profile blocks 4, 5, and 6, or block-shaped profile structures, are repeated themselves around the circumference of the tread, with the exception of various adaptations resulting from the application of methods for varying the pitch length.

[0031] As shown in Figure 1, two sipes 7 and 8 are formed within each of the profile blocks 4, 5, and 6 shown in the figure. All sipes 7 and 8 preferably extend parallel or substantially parallel to the oblique groove 1 and extend parallel to each other within the profile blocks 4, 5, and 6. Sipe 7 is adjacent to the respective leading edges 4a, 5a, and 6a, and sipe 8 is adjacent to the respective trailing edges 4b, 5b, and 6b.

[0032] In any case considered along the plan view and its extent, the sipes 7, 8 preferably extend in a straight line or substantially straight line, preferably intersecting the respective profile blocks 4, 5, 6, and in the plan view, having central sipe portions 7a, 8a and, on the opposite side, shallower edge portions 7b, 8b that begin around the tread and extend to a depth t1 of 10% to 50% of the profile depth (Figures 4, 5). The central sipe portions 7a, 8a extend over 70% to 95% of the longitudinal range of the sipes 7, 8, and in the shoulder-side profile block 6, this longitudinal range is determined from the side edge L, and in the shoulder-side profile block 6, the sipes 7, 8 each have only one edge portion 7b, 8b. In the central profile block 4, the sipes 7, 8 terminate within the profile block 4 in the illustrated exemplary embodiment. The central sipe sections 7a and 8a begin around the tread and extend to a depth t2 (Figures 2 and 3) of 60% to 95% of the profile depth, where there are optionally localized base elevations.

[0033] In each profile block 4, 5, and 6, the two sipes 7 and 8 are positioned such that they are substantially equal in distance from each other and from the respective adjacent block edges 4a, 5a, 6a and 4b, 5b, and 6b, in particular, so that the arrangement of the sipes 7 and 8 in each profile block 4, 5, and 6 corresponds to a substantially uniform arrangement.

[0034] Figures 2 and 3 show radial sections from the central sipe portions 7a and 8a, using examples of sipe 7 in profile block 6 and sipe 8 in profile block 5 (the following description also applies to sipes 7 and 8 in further profile blocks 4, 5, and 6). The drawn sipe centerline m EPerpendicular to the sipes, 7 and 8 have a constant width b of 0.40 mm to 1.00 mm, preferably up to 0.80 mm. Considering the radial direction, each central sipe portion 7a and 8a, starting from the sipe base, consists of a radially extending radially inner portion 9a and 9'a, a radially outer portion 9b and 9'b adjacent to the sipe base, and a transition portion 10 and 10' extending to the periphery of the tread. The radially outer portion 9b within sipe 7 extends at an acute angle α (Figure 2) with respect to the radial direction, and the radially outer portion 9'b within sipe 8 extends at an acute angle α' (Figure 3) to a depth t3 determined from the periphery of the tread, in each case, of 1.50 mm to 3.50 mm, preferably 2.00 mm to 3.50 mm, particularly preferably 2.50 to 3.50 mm. Each transition section 10, 10' is a short section that starts from the periphery of the tread, extends radially, and extends to a depth t4 of 0.20 mm to 0.50 mm. In any case, the radially outer sections 9b, 9'b and the transition sections 10, 10' are located at points where possible localized basal ridges exist.

[0035] In sipe 7, the angle α of the radially outer portion 9b with respect to the radial direction is 15° to 23°, preferably 20°, and in sipe 8, the angle α' of the radially outer portion 9'b is 7° to 13°, particularly preferably 10°. The radially outer portion 9b in sipe 7 encloses a radial angle at least 3°, particularly at least 5°, greater than that of the radially outer portion 9'b in sipe 8. The inclination direction of the radially outer portions 9b and 9'b in sipes 7 and 8 is the same, and as a result, portions 9b and 9'b inclin towards the front block edges 4a, 5a, and 6a, respectively, starting from their radially inner ends. Thus, the radially outer portions 9b and 9'b in sipes 7 and 8 move away from their respective front edges 4a, 5a, and 6a as the depth increases.

[0036] Figure 4 shows, for example, a partial region of the central sipe portion 7a by visualization of a part of the sipe 7, and has an embodiment of a modified edge portion 7b adjacent to that partial region. The edge portion 7b is designed to be shallower than the radially outer portion 9b which is inclined at an angle α with respect to the radial direction, and the inclination continues thereafter, so the edge portion 7b also extends at an angle α with respect to the radial direction.

[0037] Figure 5 shows a modified embodiment of the edge portion 7a, similarly by visualizing a portion of the sipe portion 7a of the sipe 7. The central sipe portion 7a and the adjacent shallow edge portion 7b are shown, which are connected to these portions via a connecting portion 11 that is oriented radially and extends at an obtuse angle to the central sipe portion 7a and the edge portion 7b.

[0038] As shown in Figures 4 and 5, the transition portion 10 is omitted. Here, the elongated depth t1 refers only to the edge portion 7b.

[0039] In alternative embodiments not shown separately, the tread includes a profile block or block-shaped profile structure in which three or more sipes, particularly three to five sipes, are formed.

[0040] Examples of such mutants are as follows:

[0041] In the case of three sipes: An example of an angular sequence of the radially outer portion of a sipe, starting from a sipe that follows the front block edge, is: The angles are 20°, 20°, 10° or 20°, 15°, 10° or 20°, 10°, 0°.

[0042] In the case of four sipes: An example of an angular sequence of the radially outer portion of a sipe, starting from a sipe that follows the front block edge, is: The angles are 20°, 15°, 10°, 0°, or 20°, 20°, 15°, 10°, or 20°, 15°, 10°, 10°.

[0043] The radially extending sipes should also be understood as portions oriented at an angle of up to 3° with respect to the radial direction. Sipes on profile blocks can extend further to the leading and trailing edges, especially at acute angles. [Explanation of Symbols]

[0044] 1. Diagonal groove 2, 3 connecting grooves 4. Central Profile Block 5. Semi-central profile block 6. Shoulder-side profile block 4a, 5a, 6a Front edge 4b, 5b, 6b Trailing edge 7. Sipes (at the anterior edge) 7a Central sipe section 7b Edge part 8. Sipes (at the trailing edge) 8a Central sipe section 8b Edge part 9a Radial inner part (Sipe 7) 9'a Radial inner portion (sipe 8) 9b Radial outer part (Sipe 7) 9'b Radial outer part (Sipe 8) 10. Transition section (Sipe 7) 10' Transition section (8 sipes) 11 Connection part α angle (at 9b) α' angle (at 9'b) b. Width of sipes 7 and 8 L side edge m E Sipe centerline R: Direction of rotation while moving forward t1 depth (edge ​​portion 7b, 8b) t2 depth (central sipe section 7a, 8a) t3 depth (radial outer part 9b, 9'b) t4 depth (transition section 10, 10')

Claims

1. A directional tread having a profile block (4, 5, 6) or a profile block-like profile structure around the tread in the case of grooves such as transverse grooves or oblique grooves (1), having a leading edge portion (4a, 5a, 6a) that first enters the contact patch during rotation of the tire while moving forward, and a trailing edge portion (4b, 5b, 6b) opposite to these leading edge portions, comprising at least two sipes (7, 8) extending parallel to each other when viewed in a plan view, wherein the sipes (b) have a width of 0.40 mm to 1.00 mm, and at least within the central sipe portion (7a, 8a) that exists along their longitudinal range within the profile block (4, 5, 6) or the block-like profile structure, there are radially inward and radially outward portions (9a, 9b; 9'a, 9'b) starting from the base of the sipe, and adjacent thereto, the radially outward portions (9b, 9'b) extend at an angle (α, α') of 5° to 35° with respect to the radial direction. A directional tread having, A pneumatic vehicle tire characterized in that, within the tread, there are profile blocks (4, 5, 6) or block-shaped profile structures (6) having at least one pair of sipes running adjacent to each other, the radially inner portions (9a, 9'a) of which run in the radial direction, and the radially outer portions (9b, 9'b) starting from the radially inner ends of which inclinate with respect to the radial direction toward the leading edge (4a, 5a, 6a), and in the sipe (7) located closer to the leading edge (4a, 5a, 6a), the radially outer portion (9b) surrounds an angle (α) with respect to the radial direction that is at least 3°, and particularly at least 5°, greater than the radially outer portion (9'b) of the other sipe (8).

2. The pneumatic vehicle tire according to claim 1, characterized in that the pair of sipes (7, 8) are the sole sipes within the tread profile blocks (4, 5, 6) or block-shaped profile structure (6).

3. The pneumatic vehicle tire according to claim 1, wherein within the tread there exists a profile block (4, 5, 6) or block-shaped profile structure having at least one further sipe located closer to the leading edge (4a, 5a, 6a), and the radially outer portion of the further sipe extends radially at an angle corresponding to the angle of the radially outer portion of the pair of sipes that is closer to the leading edge.

4. A pneumatic vehicle tire according to claim 1 or 3, wherein within the tread there exists a profile block (4, 5, 6) or block-shaped profile structure having at least one further sipe located closer to the trailing edge (4b, 5b, 6b), and the radially outer portion of the further sipe makes the angle with respect to the radial direction that corresponds to the angle of the radially outer portion of the sipe closer to the trailing edge of the pair of sipes up to that point.

5. The pneumatic vehicle tire according to claim 1, 3, or 4, characterized in that within the tread, there are profile blocks (4, 5, 6) or block-shaped profile structures in which sipes that do not have an outer portion inclined with respect to the radial direction run adjacent to the trailing edge (4b, 5b, 6b).

6. The pneumatic vehicle tire according to claim 1 or 3 to 5, characterized in that a profile block (4, 5, 6) or block-shaped profile structure having up to three further sipes is present within the tread.

7. A pneumatic vehicle tire according to any one of claims 1 to 6, characterized in that the angle (α, α') of the radially outer portion (9b) of the sipe (7) adjacent to the leading edge portion (4a, 5a, 6a), and the angle (α, α') of the radially outer portion (9b, 9'b) from the sipe (7) to the sipe (8) becomes smaller in the direction of the trailing edge portion (4b, 5b, 6b).

8. A pneumatic vehicle tire according to any one of claims 1 to 7, characterized in that a sipe (7, 8) having outer portions (9b, 9'b) that extend inclined with respect to the radial direction, each of these portions (9b, 9'b) encloses an angle (α, α') in the range of 5° to 25° with respect to the radial direction.

9. The pneumatic vehicle tire according to any one of claims 1 to 8, characterized in that the angle (α) of the radially outer portion (9b) of the sipe (7) located closest to or adjacent to the leading edge (4a, 5a, 6a) is 15° to 23°, particularly 17° to 23°, preferably 20°, and the angle of the sipe (8) located closest to or adjacent to the trailing edge (4b, 5b, 6b) is 7° to 13°, particularly 10°.

10. The radially outer portions (9b, 9'b) determined from the periphery of the tread have a depth of 1.50 mm to 3.50 mm, particularly 2.00 mm to 3.50 mm, preferably 2.50 mm to 3.50 mm (t ３ A pneumatic vehicle tire according to any one of claims 1 to 9, characterized in that it extends to ).

11. The sipes (7, 8) are determined from the periphery of the tread, and the depth of the central sipe portion (7a) is (t ２ The aforementioned depth (t) is lower than ) １ A pneumatic vehicle tire according to any one of claims 1 to 10, characterized in that it has at least one edge portion (7b) that extends to the )

12. The edge portion (11) determined from the tread area is to a depth of 10% to 50% of the profile depth (t １ The pneumatic vehicle tire according to claim 11, characterized in that it extends to ).

13. The sipes (7, 8) each start from the periphery of the tread, extend radially, and have a depth of 0.20 mm to 0.50 mm (t ４ A pneumatic vehicle tire according to any one of claims 1 to 12, characterized in that it has a transition portion (10, 10') that extends to ).

Images