Pneumatic vehicle tyre
Patent Information
- Application Number
- EP2024715080
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-03-24
- Filing Date
- 2024-03-21
- Publication Date
- 2026-02-11
AI Technical Summary
Pneumatic vehicle tires with directional tread patterns experience uneven abrasion of block segments, leading to undesirable noise phenomena during rolling, which affects traction and noise quality.
The tire design incorporates pairs of adjacent incisions with radially inner sections running radially and radially outer sections inclined towards the incoming edge, with varying angles to ensure uniform abrasion and reduce noise, while also enhancing traction and cornering performance.
This design effectively evens out the abrasion of block segments, reducing undesirable noise and improving the tire's response to lateral forces, thereby enhancing traction and noise quality.
Smart Images
Figure EP2024057535_03102024_PF_FP_ABST
Abstract
Description
[0001] 202206439
[0002] Description
[0003] Pneumatic vehicle tires
[0004] The invention relates to a pneumatic vehicle tire with a tread designed in a directional manner with profile blocks or block-like profile structures which, on the tread periphery in the case of grooves such as transverse grooves or oblique grooves, have leading edges which first enter the ground when the tire rolls when driving forward and edges which run out opposite these and are provided with at least two cuts which extend parallel to one another in plan view and which each have a width of 0.40 mm to 1.00 mm and, within a central cut section present along their longitudinal extent in the profile block or the block-like profile structure, have a radially inner section and adjoining this a radially outer section, wherein the radially outer section runs at an angle of 5° to 35° to the radial direction.
[0005] Such a pneumatic vehicle tire is known, for example, from WO 2017 / 213230 A1. The tread of this tire has profile blocks, each with a number of axially extending cuts, which, in the radial direction, starting at the cut base, are composed of two cut sections that are inclined with respect to the radial direction, with their angles of inclination being opposite with respect to the tread periphery. Each profile block contains at least four cuts, which have identically inclined cut sections or are designed such that the bends between the two cut sections of one half of the cuts face the bends between the cut sections of the second half of the cuts.Tires with treads containing such tread blocks are primarily intended to have good ice performance and be easy to demold after vulcanization in a vulcanization mold.
[0006] Further pneumatic vehicle tires with treads featuring profile blocks with cuts, which have two sections in the radial direction that form an obtuse angle with each other, one of which is a section extending radially from the base of the cut, and the second, adjoining section, which runs inclined toward the tread periphery at an acute angle to the radial direction, are known from DE 10 2019 206 591 A1 and DE 10 2019 206 592 A1. Tires with treads featuring profile blocks with cuts designed in this way are said to be improved, especially with regard to aeroplaning properties and braking properties on dry roads, as well as to ensure good snow performance.
[0007] Sipes with radially outer sections running at an acute angle to the radial direction in the area of the tread periphery improve snow grip and braking performance on dry roads due to the pressure angle present at the tread periphery and reduce curling effects at the corresponding sipe edge on the tread surface. In addition, wear is reduced due to a reduced snap-out effect under traction. Depending on the local stiffness of the individual block segments formed by the sipes, such sipes have varying degrees of effectiveness. Particularly in pneumatic vehicle tires with directional tread patterns, varying degrees of wear of the block segments can occur, which can cause undesirable noise phenomena, for example due to sawtooth formation.
[0008] The invention is therefore based on the object of continuing to ensure the above-mentioned positive effects of the cuts in a pneumatic vehicle tire of the type mentioned at the outset with a directional tread pattern, wherein locally varying wear of block segments is to be prevented, in particular also to avoid undesirable noise phenomena, such as certain audible frequencies in the rolling noise.
[0009] The stated object is achieved according to the invention in that profile blocks or block-like profile structures with at least one pair of adjacent incisions are present in the tread, the radially inner sections of which run in the radial direction and the radially outer sections of which are inclined to the radial direction, in each case starting from their radially inner end, towards the leading edge, wherein in that incision which is closer to the leading edge, the radially outer section encloses an angle with the radial direction which is at least 3°, in particular at least 5°, greater than the radially outer section of the other incision.
[0010] The invention allows the wear of block segments formed by cuts in the tread blocks or segments in the block-like tread structures to be evened out, particularly through the different inclinations of the radially outer sections of the cuts and the consistent inclination of these sections with respect to the leading edges. This also largely eliminates undesirable noise phenomena in the rolling noise. These measures also advantageously allow the tire to respond particularly well to lateral forces when changing lanes or cornering.
[0011] In a preferred embodiment of the invention, the pairs of cuts are the only cuts in the profile blocks or block-like profile structures of the tread. In directional treads, two cuts in the profile blocks or block-like profile structures in certain tread areas, for example, in the center of the tread, can be used to particularly advantageously influence the circumferential and transverse stiffness of the individual block segments with respect to promoting even wear or achieving precise power transmission during steering forces.
[0012] In further advantageous embodiments, at least one further cut is present in profile blocks or block-like profile structures, which has a radially inner section which runs in the radial direction, and a radially outer section which runs inclined to the radial direction, in each case starting from its radially inner end towards the leading edge.
[0013] In this case, profile blocks or block-like structures can be present in the tread, in each of which a further cut is formed which is closer to the leading edge, in which case the radially outer section of the further cut runs at an angle to the radial direction which corresponds at least to the angle of the radially outer section, also relative to the radial direction, of that cut which is closer to the leading edge from the pair of cuts.
[0014] If, according to a further advantageous embodiment, profile blocks or block-like profile structures with at least one further incision located closer to the trailing edge are present in the tread, it is advantageous if the radially outer section of the further incision runs at an angle to the radial direction which corresponds at most to the angle of the radially outer section of that incision which is closer to the trailing edge from the pair of incisions.
[0015] The further incisions are therefore advantageously designed in such a way that they support uniform wear of the profile blocks or block-like profile structures in the directional design of the tread.
[0016] In the case of more than two cuts in profile blocks or block-like profile structures, in particular adjacent to the trailing edge, there may also be a cut which does not have an outer section inclined to the radial direction.
[0017] For tread designs with profile blocks or block-like profile structures with larger circumferential lengths, design variants are possible and advantageous in which up to three additional cuts are present.
[0018] For the uniform wear of profile blocks or block-like profile structures in the tread, it can also be particularly advantageous if the angle of the radially outer sections from cut to cut becomes smaller, starting with the radially outer section of the cut adjacent to the leading edge, in the direction of the trailing edge.
[0019] For the effect of the incisions with regard to equalizing the abrasion, it is furthermore advantageous if, in incisions with outer sections running inclined to the radial direction, these sections each enclose an angle in the range of 5° to 25° with the radial direction, wherein in a preferred embodiment the angle of the radially outer section in the incision closest to or adjacent to the leading edge is 15° to 23°, in particular 17° to 23°, preferably 20°, the angle of the radially outer section in the incision closest to or adjacent to the leading edge is 7° to 13°, in particular 10°.
[0020] Particularly effective are radially outer sections in the respective cuts which, as measured from the tread periphery, extend to a depth of 1.50 mm to 3.50 mm, in particular from 2.00 mm to 3.50 mm and preferably from 2.50 mm to 3.50 mm.
[0021] Typically, sipes running in tread blocks or block-like tread structures end at least at one end in a groove. Particularly in the area where grooves join, it is advantageous if the sipes each have an edge section that, measured from the tread periphery, extends to a depth that is less than the depth of the central sipe section. The edge sections can extend to different depths; in preferred designs, they extend from the tread periphery to a depth of 10% to 50% of the tread depth.
[0022] In a further design, the sipes each have a transition section extending radially from the tread periphery to a depth of 0.20 mm to 0.50 mm. These very shallow transition sections are formed by corresponding sections on the metallic sipes that form the sipes during tire vulcanization in a vulcanization mold. These sipe sections serve to ensure particularly clean demolding of the tread in the area of the sipes after vulcanization, without tears.
[0023] Further features, advantages and details of the invention will now be described in more detail with reference to the schematic and simplified drawing, which shows an embodiment of the invention.
[0024] Fig. 1 is a plan view of a section of a circumferential portion of a tread of a pneumatic vehicle tire with an embodiment variant of the invention,
[0025] Fig. 2 is an enlarged sectional view along the line ll-ll of Fig. 1,
[0026] Fig. 3 is an enlarged sectional view along the line III-III of Fig. 1,
[0027] Fig. 4 and Fig. 5 Visualizations (drawing bodies) of incision sections.
[0028] Pneumatic vehicle tires designed according to the invention are tires for motor vehicles, in particular for multi-track motor vehicles, preferably radial tires for passenger cars (PCs), vans (transporters), SUVs or light trucks (light trucks with a GVW < 7.5 t). Fig. 1 shows a plan view of a circumferential section of a tread belonging to a pneumatic vehicle tire with a directional tread pattern so that the pneumatic vehicle tire is to be mounted on the vehicle in such a way that it has the rolling direction indicated by the arrow R when driving forward. The line AA denotes the tire equatorial plane of the tire, the two lateral edges of the ground contact area of the tread are each marked by a line L.
[0029] In the embodiment shown, the tread in each tread half has oblique grooves 1 which, in plan view, run parallel to one another and in sections are slightly curved. These grooves extend from the area of the tire equatorial plane AA to beyond the lateral edges L and are generally essentially V-shaped overall and offset from one another in the circumferential direction in the tread halves across the width of the tread. The oblique grooves 1 are preferably designed over most of their extent to the respectively intended tread depth of in particular 6.0 mm to 9.5 mm and are the main (drainage) grooves of the tread. As usual, the term tread depth refers to the depth of the deepest main grooves on a new tire.
[0030] The inner end of each oblique groove 1 of the tread terminates in a oblique groove 1 running in the other half of the tread. Between the circumferentially adjacent oblique grooves 1, two connecting grooves 2, 3 run. These grooves are inclined in the opposite direction to the oblique grooves 1 with respect to the circumferential direction and have a depth in the range of 30% to 70% of the tread depth. The connecting grooves 3 each run at an acute angle of 5° to 15° to the circumferential direction, and the connecting grooves 3' run at an angle of 30° to 45°.
[0031] The oblique grooves 1 together with the connecting grooves 3, 3' divide the
[0032] Treads are divided into central tread blocks 4, semi-central tread blocks 5, and shoulder-side tread blocks 6. In the area of the central and semi-central tread blocks 4, 5, the oblique grooves 1 extend, in plan view, to the axial direction, particularly at an angle of 30° to 50°, and in the area of the shoulder-side tread blocks 6, at an angle of 0° to 20° to the axial direction. In an alternative design, for example, the central and semi-central tread blocks are connected to form block-like tread structures.
[0033] Each tread block 4, 5, and 6 has, on the tread periphery, a leading edge 4a, 5a, and 6a formed adjacent to one oblique groove 1, and a trailing edge 4b, 5b, and 6b formed adjacent to the other oblique groove 1. The leading edges 4a, 5a, and 6a of a block 4, 5, and 6 are the block edges that first enter the ground when the tire rolls forward (arrow R).
[0034] The profile blocks 4, 5 and 6 or the block-like profile structures are repeated over the circumference of the tread, except for various adjustments resulting from the application of a pitch length variation process
[0035] As shown in Fig. 1, two incisions 7, 8 are formed in each of the illustrated tread blocks 4, 5, and 6. All incisions 7, 8 preferably run parallel or substantially parallel to the oblique grooves 1 and parallel to one another within the tread blocks 4, 5, and 6. The incisions 7 are the incisions adjacent to the respective leading edge 4a, 5a, 6a, and the incisions 8 are the incisions adjacent to the respective trailing edge 4b, 5b, 6b.
[0036] The incisions 7, 8 run, each viewed in plan view and along their extent, preferably straight or essentially straight and preferably traversing the respective tread block 4, 5, 6, and have, in plan view, central incision sections 7a, 8a and, relative to these, shallower edge sections 7b, 8b which, starting from the tread periphery, reach to a depth ti (Fig. 4, Fig. 5) of 10% to 50% of the tread depth. The central incision sections 7a, 8a extend over 70% to 95% of the longitudinal extent of the incisions 7, 8, wherein this longitudinal extent in the shoulder-side tread blocks 6 is determined from the lateral edges L and the incisions 7, 8 in the shoulder-side tread blocks 6 each have only one edge section 7b, 8b. In the central profile blocks 4, the incisions 7, 8 end within the profile blocks 4 in the embodiment shown.The central incision sections 7a, 8a extend in the radial direction, starting from the tread periphery and, if necessary, to locations with local base elevations, to a depth t2 (Fig. 2, Fig. 3) of 60% to 95% of the profile depth.
[0037] In each profile block 4, 5 and 6, the two incisions 7, 8 are arranged in particular in such a way that they are at substantially equal distances from one another and from the adjacent block edges 4a, 5a, 6a and 4b, 5b and 6b, so that the arrangement of the incisions 7, 8 in each profile block 4, 5 and 6 essentially corresponds to a uniform arrangement.
[0038] Fig. 2 and Fig. 3 show, using the example of a cut 7 in a tread block 6 and a cut 8 in a tread block 5 (the following description applies analogously to the cuts 7, 8 in the other tread blocks 4, 5 and 6), radial cross-sections of central cut sections 7a, 8a. Perpendicular to the drawn cut center line mE, the cuts 7, 8 have a particularly constant width b of 0.40 mm to 1.00 mm, preferably of up to 0.80 mm. Viewed in the radial direction, each central cut section 7a, 8a is composed, starting from the cut base, of a radially inner section 9a, 9'a running in the radial direction, a radially outer section 9b, 9'b adjoining this, and a transition section 10, 10' running to the tread periphery. The radially outer section 9b in a notch 7 runs at an acute angle a to the radial direction (Fig.2), the radially outer section 9'b in a cut 8 at an acute angle a' (Fig. 3), in each case to a depth ts determined from the tread periphery of 1.50 mm to 3.50 mm, preferably from 2.00 mm to 3.50 mm, particularly preferably from 2.50 to 3.50 mm. Each transition section 10, 10' is a short section which extends in the radial direction from the tread periphery to a depth t4 of 0.20 mm to 0.50 mm. The radially outer section 9b, 9'b and the transition section 10, 10' are in any case located at a point with a possible local base elevation.
[0039] In the incisions 7, the angle a of the radially outer sections 9b relative to the radial direction is 15° to 23°, preferably 20°; in the incisions 8, the angle a' of the radially outer sections 9'b is 7° to 13°, in particular and preferably 10°. The radially outer section 9b in the incisions 7 encloses an angle with the radial direction that is at least 3°, in particular at least 5°, greater than the radially outer section 9'b in the incision 8. The directions of inclination of the radially outer sections 9b, 9'b in the incisions 7, 8 are the same and such that the sections 9b, 9'b are each inclined, starting from their radially inner ends, in the direction of the incoming block edge 4a, 5a, 6a. The radially outer sections 9b, 9'b in the incisions 7, 8 therefore move away from the respective incoming edge 4a, 5a, 6a with increasing depth.
[0040] Fig. 4 shows, by way of example, a visualization of a section of an incision 7, a partial area of the central incision section 7a with a variant of the adjacent edge section 7b. In the edge section 7b, which is shallower than the radially outer section 9b, which is inclined at an angle a to the radial direction, the inclination of the latter is continued; therefore, the edge section 7b also runs at an angle a to the radial direction.
[0041] Fig. 5 shows a variant of the design of an edge section 7a, also based on a visualization of a section of the incision section 7a of an incision 7. Shown are a partial area of the central incision section 7a and the shallow edge section 7b adjoining it, which is oriented in the radial direction here and is connected to these sections via a connecting section 11 which runs at obtuse angles to the central incision section 7a and to the edge section 7b.
[0042] In Fig. 4 and Fig. 5, the transition sections 10 have been omitted. The depth ti shown here refers only to the edge section 7b.
[0043] In alternative designs, which are not shown separately, profile blocks or block-like profile structures are present in the tread in which more than two cuts, in particular three to five cuts, are formed.
[0044] Examples of such variants are:
[0045] With three incisions:
[0046] Examples of angular sequences of the radially outer sections of the cuts, starting with the cut following the incoming block edge: 20°, 20°, 10° or 20°, 15°, 10° or 20°, 10°, 0°.
[0047] With four incisions:
[0048] Examples of angular sequences of the radially outer sections of the cuts, starting with the cut following the incoming block edge: 20°, 15°, 10°, 0° or 20°, 20°, 15°, 10° or 20°, 15°, 10°, 10°.
[0049] Radially extending incision sections also include sections oriented at an angle of up to 3° to the radial direction. The incisions in the tread blocks can also extend to the leading and trailing edges, particularly at acute angles.
[0050] 1 diagonal groove
[0051] 2, 3 connecting groove
[0052] 4 central profile block
[0053] 5 semi-central profile block 6 shoulder-side profile block
[0054] 4a, 5a, 6a leading edge
[0055] 4b, 5b, 6b tapered edge
[0056] 7 Notch (at leading edge)
[0057] 7a central incision section 7b edge section
[0058] 8 Incision (at tapered edge)
[0059] 8a central incision section
[0060] 8b edge section
[0061] 9a radial inner section (notch 7) 9'a radial inner section (notch 8)
[0062] 9b radial outer section (notch 7)
[0063] 9'b radial outer section (notch 8)
[0064] 10 Transition section (cut 7)
[0065] 10' Transition section (cut 8) 11 Connecting section a Angle (at 9b) a' Angle (at 9'b) b Width of cuts 7, 8
[0066] L lateral margin I IE incision center line
[0067] R Rolling direction when driving forward ti Depth (edge sections 7b, 8b)
Claims
Patent claims 1. Pneumatic vehicle tire with a directional tread with profile blocks (4, 5, 6) or profile block-like profile structures, which have, on the tread periphery in the case of grooves, such as transverse grooves or diagonal grooves (1), leading edges (4a, 5a, 6a) which first enter the ground when the tire rolls during forward travel, and edges (4b, 5b, 6b) which run out opposite these, and are provided with at least two cuts (7, 8) which extend parallel to one another in plan view, which have a width of (b) 0.40 mm to 1.00 mm and, at least within a central cut section (7a, 8a) present along their longitudinal extent in the profile block (4, 5, 6) or the block-like profile structure, starting from the cut base, a radially inner section and adjoining this a radially outer section (9a, 9b;9'a, 9'b), wherein the radially outer section (9b, 9'b) runs at an angle (a, a') of 5° to 35° to the radial direction, characterized in that in the tread there are profile blocks (4, 5, 6) or block-like profile structures (6) with at least one pair of adjacent incisions, the radially inner sections (9a, 9'a) of which run in the radial direction and the radially outer sections (9b, 9'b) of which are inclined to the radial direction, in each case starting from their radially inner end, towards the leading edge (4a, 5a, 6a), wherein in that incision (7) which is closer to the leading edge (4a, 5a, 6a), the radially outer section (9b) encloses an angle (a) with the radial direction which is at least 3°, in particular at least 5°, greater than the radially outer section (9'b) of the other incision (8).; 2. Pneumatic vehicle tire according to claim 1, characterized in that the pairs of cuts (7, 8) are the only cuts in profile blocks (4, 5, 6) or block-like profile structures (6) of the tread.
3. Pneumatic vehicle tire according to claim 1, characterized in that profile blocks (4, 5, 6) or block-like profile structures with at least one further cut closer to the leading edge (4a, 5a, 6a) are present in the tread, the radially outer section of the further cut extending at an angle in the radial direction which corresponds at least to the angle of the radially outer section of that cut which is closer to the leading edge from the pair of cuts.
4. Pneumatic vehicle tire according to claim 1 or 3, characterized in that profile blocks (4, 5, 6) or block-like profile structures with at least one further cut closer to the trailing edge (4b, 5b, 6b) are present in the tread, the radially outer section of the further cut extending at an angle to the radial direction which corresponds at most to the angle of the radially outer section of that cut which is closer to the trailing edge from the pair of cuts.
5. Pneumatic vehicle tire according to claim 1, 3 or 4, characterized in that profile blocks (4, 5, 6) or block-like profile structures are present in the tread, in which a cut runs adjacent to the trailing edge (4b, 5b, 6b) which does not have an outer section inclined to the radial direction.
6. Pneumatic vehicle tire according to claim 1 or 3 to 5, characterized in that profile blocks (4, 5, 6) or block-like profile structures with up to three further cuts are present in the tread.
7. Pneumatic vehicle tire according to one of claims 1 to 6, characterized in that the angle (a, a') of the radially outer sections (9b, 9'b) from cut (7) to cut (8), starting at the radially outer section (9b) of the cut (7) adjacent to the leading edge (4a, 5a, 6a), becomes smaller in the direction of the trailing edge (4b, 5b, 6b).
8. Pneumatic vehicle tire according to one of claims 1 to 7, characterized in that in cuts (7, 8) with outer sections (9b, 9'b) running inclined to the radial direction, these sections (9b, 9'b) each enclose an angle (a, a') in the range from 5° to 25° with the radial direction.
9. Pneumatic vehicle tire according to one of claims 1 to 8, characterized in that the angle (a) of the radially outer section (9b) of the incision (7) closest to or adjacent to the leading edge (4a, 5a, 6a) is 15° to 23°, in particular 17° to 23°, preferably 20°, in that of the incision (8) closest to or adjacent to the trailing edge (4b, 5b, 6b) is 7° to 13°, in particular 10°.
10. Pneumatic vehicle tire according to one of claims 1 to 9, characterized in that the radially outer sections (9b, 9'b), determined from the tread periphery, each extend to a depth (ts) of 1.50 mm to 3.50 mm, in particular of 2.00 mm to 3.50 mm and preferably of 2.50 mm to 3.50 mm.
11. Pneumatic vehicle tire according to one of claims 1 to 10, characterized in that the cuts (7, 8) have at least one edge portion (7b) which, determined from the tread periphery, extends in each case to a depth (ti ) which is less than the depth (t2) of the central cut portion (7a).
12. Pneumatic vehicle tire according to claim 11, characterized in that the edge sections (11), determined from the tread periphery, extend to a depth (ti) of 10% to 50% of the tread depth.
13. Pneumatic vehicle tyre according to one of claims 1 to 12, characterised in that the cuts (7, 8) each comprise a groove extending from the tread periphery and in the radial direction transition section (10, 10') which extends to a depth (t4) of 0.20 mm to 0.50 mm.