Pneumatic vehicle tyre

Abstract

The invention relates to a pneumatic vehicle tyre having a tread with profile positives (4, 5, 6) delimited by grooves (1, 2, 3), wherein profile positives (5) are provided which, when viewed from above, have incisions (7, 8) running, at least in sections, at an angle (α) of 0° to 50° to the axial direction, having a width (bE) of 0.4 mm to 1.6 mm and a depth (te) at the deepest point, which is at least the profile depth (TP) minus 4.5 mm, and at most 100% of the profile depth (TP), wherein the incisions (7, 8) each form at least one abrasion indicator (7b, 8b). The abrasion indicator (7b, 8b) is formed by an incision section (7b, 8b) of the incision (7, 8), having the shape, when viewed from above, of a sun symbol or snowflake symbol.

Description

[0001] Description

[0002] Pneumatic vehicle tires

[0003] The invention relates to a pneumatic vehicle tire with a tread with profile positives delimited by grooves, wherein profile positives are provided which are provided with incisions which, in plan view, run at least in sections at an angle of 0° to 50° to the axial direction and have a width of 0.4 mm to 1.6 mm and a depth at the deepest point which is at least the profile depth reduced by 4.5 mm and at most 100% of the profile depth, wherein the incisions each form at least one abrasion indicator.

[0004] Wear indicators formed on the treads of pneumatic vehicle tires are known in various designs. Conventional wear indicators are primarily formed by negative tread features, such as cuts or depressions, or by positive tread features, preferably projections formed in grooves. Projections serving as wear indicators locally reduce the groove cross-section and can adversely affect water drainage. Depressions intended as wear indicators locally reduce tread stiffness, which can result in uneven wear and adversely affect dry performance.

[0005] A pneumatic vehicle tire of the type mentioned above is known, for example, from DE 102011 054 662 A1. The pneumatic vehicle tire has a tread with profile positives, each with at least two cuts, one cut also forming a wear indicator. When a residual tread depth is reached, the cut that also forms the wear indicator has a different geometry than the other cut, which is clearly visible to the human eye in plan view. In the described embodiment, the cut that also forms the wear indicator has a radially outer cut section that is wave-shaped in plan view in sections, and a radially inner cut section, the radially inner cut section running straight when viewed in plan view after the radially outer cut section has been worn away.The advantage of wear indicators integrated into grooves lies in the fact that, unlike the conventional wear indicators mentioned above, they do not affect the groove cross-section and have little impact on local tread stiffness. With previously known wear indicators integrated into grooves, the information content conveyed to the observer is limited. In particular, there is a risk that the wear indicator may not even be perceived as such.

[0006] The invention is therefore based on the object of providing a clearly recognizable and self-explanatory abrasion indicator for a pneumatic vehicle tire of the type mentioned above, wherein the advantages of the abrasion indicators integrated in cuts are to be retained.

[0007] The stated object is achieved according to the invention in that the abrasion indicator is formed by an incision section of the incision which, in plan view, has the shape of a sun symbol or a snowflake symbol.

[0008] The cut section, shaped like such a symbol, forms a clearly visible wear indicator even when the tire is new, and its function is self-explanatory to the observer. The advantages associated with wear indicators integrated into cuts remain intact.

[0009] According to a preferred embodiment, the cut section extends to the base of the cut while maintaining its shape. After the cut section has been worn down, the cut section disappears completely, making it particularly easy to detect when a specific wear condition has been reached. According to another preferred embodiment, the cut section ends at a radially determined distance before the level of the maximum depth of the cut. Therefore, after the cut section has been worn down, a portion of the cut remains in the tread pattern, which is advantageous, for example, for snow grip properties.

[0010] Preferably, the incision section has a radial distance of 1.6 mm to 4.5 mm from the tread depth level. This indicates particularly relevant wear conditions.

[0011] According to a further preferred embodiment, the sun-shaped incision section has a radial distance of 1.6 mm to 2.0 mm, in particular 1.6 mm or 2.0 mm, from the tread depth level. In this embodiment, the sun-shaped incision section functions as a "summer wear indicator." 1.6 mm corresponds to the currently smallest legally required minimum tread depth in EU countries. A correspondingly larger distance provides a "safety buffer" in this respect.

[0012] A further preferred embodiment is characterized in that the incision section in the shape of a sun symbol is formed by a first subsection extending over a circular arc, in particular over the circular arc of a semicircle, and at least three, in particular four, elongated and radially extending second subsections emanating from the outer side of the circular arc of the first subsection. Such a sun symbol has a particularly characteristic shape and is therefore particularly easy to classify and recognize.

[0013] In the latter preferred embodiment, it is advantageous if the second subsections are shallower than the first subsection, with the incision base in the region of the second subsections being inclined to the radial direction such that each second subsection becomes continuously deeper toward the first subsection. As tread wear increases, the second subsections, symbolizing the sun's rays, continuously shorten, allowing the tread wear to be monitored particularly well shortly before reaching a critical area.

[0014] According to a further preferred embodiment, the incision section in the shape of a snowflake symbol has a radial distance of 3.0 mm to 4.5 mm, in particular 3.0 mm or 4.0 mm, from the tread depth level. In this embodiment, the incision section in the shape of a snowflake symbol functions as a "winter wear indicator." 3.0 mm or 4.0 mm corresponds to the legally prescribed minimum tread depth for winter tires in some EU countries. A correspondingly larger distance provides a "safety buffer" in this respect.

[0015] In a preferred variant of the latter preferred embodiment, the incision section having the shape of a snowflake symbol is formed by at least three, in particular four, first subsections extending along the edges of a hexagon, in particular a regular hexagon, and by branched second subsections extending at the mutual connection points of the first subsections. Such a snowflake symbol has a particularly characteristic shape and is therefore particularly easy to classify and recognize.

[0016] In the last-mentioned preferred variant, it is advantageous if the branched, second subsections, viewed in plan view, are each Y-shaped, with the Y-trunk adjoining the mutual junction of two first subsections and the Y-trunk preferably continuing between the Y-branches. This further improves the appearance of the snowflake symbol. According to a further preferred embodiment, the incision section, viewed in plan view, has one, in particular precisely one, plane of symmetry. The symmetrical design of the symbolic incision section further improves its recognizability.

[0017] A further preferred embodiment is characterized in that the incision section does not terminate in a groove. This ensures that the effects of the incision on the stiffness of the respective profile positive are uniform, which is beneficial, for example, for abrasion behavior.

[0018] A preferred variant of the last-mentioned preferred embodiment consists in providing pairs of incisions in the same positive profile, one incision having the incision section in the shape of a sun symbol and the other incision having the incision section in the shape of a snowflake symbol, the incisions being formed in pairs such that the incision sections are at least partially opposite one another. This creates a particularly conspicuous incision combination at one point on the profile, providing both a "summer abrasion indicator" and a "winter abrasion indicator." Compared to conventional incisions, the sun symbol and the snowflake symbol increase the overall length or empty volume of the respective incision.In this respect, the paired incisions can be regarded as a sectionally interrupted incision, whereby this interruption compensates for the larger incision empty volume caused by the symbols or the larger incision length caused by the symbols, which is advantageous for the stiffness of the profile positive or the stiffness distribution within the profile positive.

[0019] In the latter variant, it is advantageous if the incisions are each composed of an incision section in the shape of a sun symbol or a snowflake symbol and a further incision section, in particular each terminating in a groove, wherein the further incision sections, viewed in plan view, preferably run in alignment with one another. This is advantageous for the rigidity of the positive profile, while, above all, the usual segmentation of the positive profile associated with incisions is essentially retained.

[0020] Further features, advantages and details of the invention will now be explained in more detail with reference to the drawing, which schematically shows an embodiment of the invention.

[0021] Fig. 1 is a simplified plan view of a circumferential section of a tread of a pneumatic vehicle tire with an embodiment variant of the invention,

[0022] Fig. 2 is an enlarged plan view of the profile block of the tread located in detail Z2 of Fig. 1,

[0023] Fig. 3 is a greatly enlarged plan view of the detail Z3 of Fig. 1 ,

[0024] Fig. 4 a visualization of two incisions formed in the profile block from Fig. 2 (drawing body of the incisions),

[0025] Fig. 5 is an enlarged front view of the visualization of one incision according to the direction of view indicated by the arrow Ss in Fig. 2 and

[0026] Fig. 6 is an enlarged front view of the visualization of the other incision according to the viewing direction indicated by the arrow Se in Fig. 2.

[0027] Pneumatic vehicle tires designed according to the invention are tires for motor vehicles, in particular for multi-track motor vehicles, and preferably tires of radial design for passenger cars, vans or light trucks (small vans with a GVW < 3.51, light trucks with a GVW < 7.5 t), the tires being intended in particular for year-round use or for driving under winter driving conditions.

[0028] Fig. 1 shows a plan view of a circumferential section of a tread of a pneumatic vehicle tire. The tread is directional, and the pneumatic vehicle tire is to be mounted on the axle of a vehicle in such a way that it has the rolling direction indicated by arrow R when driving forward. The tire's equatorial plane is indicated by a line AA.

[0029] In each tread half, the tread has oblique grooves 1 which, in plan view, run parallel to one another and extend from the region of the tire equatorial plane to the tread edges, run in an overall V-shape across the tread width, and are designed, at least over the majority of their extent, to the respectively intended tread depth TP (indicated in Fig. 5 and Fig. 6), in particular from 6.0 mm to 9.5 mm, and are thus the main (drainage) grooves of the tread, wherein the oblique grooves 1 running in different tread halves are offset from one another in the circumferential direction. The term "tread depth" refers to the depth of the deepest main (drainage) groove(s) in treads with main (drainage) grooves of different depths.Adjoining the inner end of each oblique groove 1 is a notch-like groove 2, which opens into the respective oblique groove 1 running in the other tread half. Furthermore, in each tread half, between circumferentially adjacent oblique grooves 1, two short grooves 3 run, which are inclined in the opposite direction to the oblique grooves 1 with respect to the circumferential direction and which are each provided with a notch (not numbered) extending from their groove base.

[0030] The oblique grooves 1 and the short grooves 3 divide the tread into central tread blocks 4, semi-central tread blocks 5 and shoulder-side tread blocks 6 belonging to shoulder-side tread block rows. The oblique grooves 1 extend in the area of ​​the central tread blocks 4 and the semi-central tread blocks 5 in plan view to the axial direction at an angle of up to 50° and in the area of ​​the shoulder-side tread blocks 6 to the axial direction at an angle of 0° to 20°.

[0031] Each tread block 4, 5, 6 has on the tread periphery a block outer surface 4c (tread block 4), 5c (tread block 5), 6c (tread block 6), an incoming block edge 4a (tread block 4), 5a (tread block 5), 6a (tread block 6) formed on one adjacent oblique groove 1 and an outgoing block edge 4b ​​(tread block 4), 5b (tread block 5), 6b (tread block 6) formed on the other adjacent oblique groove 1, wherein when the tire rolls during forward travel (arrow R) the incoming block edge 4a, 5a, 6a enters the ground before the outgoing block edge 4b, 5b, 6b.

[0032] In each tread half, in the circumferential section shown, a semi-central profile block 5 is provided with two incisions 7, 8 extending from the associated block outer surface 5c and ending closed on one side. Preferably, several semi-central profile blocks 5 with incisions 7, 8 are provided in each tread half.

[0033] The further design of the incisions 7, 8 is explained below using individual incisions 7, 8 formed in a semi-central profile block 5.

[0034] Fig. 2 shows a plan view of a semi-centered tread block 5 as well as the adjacent short grooves 3 and the adjacent sections of the oblique grooves 1. The cut 7 opens into the short groove 3 bordering the semi-centered tread block 5 on the inside of the tread, ends closed in the semi-centered tread block 5, and is inclined in the axial direction in a manner consistent with the block edges 5a, 5b. The cut 8 opens into the short groove 3 bordering the semi-centered tread block 5 on the outside of the tread, ends closed in the semi-centered tread block 5, and is inclined in the axial direction in a manner consistent with the block edges 5a, 5b.The incision 7, 8 is composed, viewed in plan view, of an edge-side incision section 7a, 8a opening into the respective short groove 3 and a symbolically designed, inside incision section 7b, 8b forming an abrasion indicator, wherein the inside incision section 7b is partially opposite the inside incision section 8b. The incision 7, 8 is in each case delimited by an incision base 9 (Fig. 4) and two incision walls 10 (Fig. 4) running in particular in the radial direction and has a width be of 0.4 mm to 1.6 mm, in particular of up to 1.2 mm, particularly preferably of up to 0.8 mm, and in the radial direction a maximum depth tE (depth at the deepest point, Fig. 5: incision 7, Fig. 6: incision 8) of up to 100% of the profile depth TP (Fig. 5, Fig. 6), the maximum depth tE preferably being the profile depth Tp reduced by 0.75 mm to 1.5 mm.

[0035] The edge-side incision sections 7a, 8a, viewed in plan view, are barely perceptibly curved, inclined in the same direction with respect to the circumferential direction as the oblique grooves 1, at an angle a of 40° to 50° to the axial direction and aligned with each other, so that they define a common incision base line LEB, and, also viewed in plan view, each have a center line m following their course a where the two center lines m a together with a connecting line v, which is straight and between the mutually facing ends of the center lines m a forms the incision base line LEB. The edge incision sections 7a, 8a are spaced apart from each other by a distance a measured along the connecting line v vand are designed in the radial direction at least over a part of their extent, in particular a large part of their extent, to the mentioned maximum depth tE (Fig. 5: incision section 7a, Fig. 6: incision section 8a). The angle a refers to a respective position of the corresponding center line m a applied tangent (not shown) and the width bE is determined perpendicular to the respective tangent.

[0036] As shown in Fig. 5 and Fig. 6, the edge-side incision sections 7a, 8a in the embodiment shown each have a radially raised edge region (not numbered) which opens into the respective short groove 3 (see Fig. 2) and has a depth tER determined in the radial direction of 30% to 70% of the maximum depth tE.

[0037] According to Fig. 3, the inner incision sections 7b, 8b, viewed in plan view, extend in a multiply branched manner, with the inner incision section 7b being designed in the shape of a sun symbol and the inner incision section 8b in the shape of a snowflake symbol. The inner incision sections 7b, 8b extend radially into the semi-central profile block 5 while maintaining their symbolic shape (Fig. 4).

[0038] The inner incision section 7b has, viewed in plan view, a plane of symmetry Ei, which runs perpendicular to the incision base line LEB and in the radial direction, and is composed, also viewed in plan view, of a subsection 7b running over the circular arc of a semicircle 1 and four on subsection 7b 1 evenly distributed and from the outside of the circular arc of subsection 7b 1outgoing, elongated, radial and straight subsections 7b" and has a correspondingly branched, partially curved and partially straight center line mb.

[0039] Subsection 7b 1 runs from the edge-side cutting section 7a in the direction of the outgoing block edge 5b (Fig. 2) and back to the cutting base line LEB, whereby the section corresponding to the subsection 7b 1 underlying circle center Pi is preferably located on the connecting line v and where subsection 7b 1 a length ci corresponding to the diameter of the semicircle, measured along the connecting line v, relative to the center line mb, of 3.0 mm to 5.0 mm. According to Fig. 5, subsection 7b ends. 1in the radial direction in front of the level of the maximum depth tE and has - measured from the incision base 9 - a distance of 1.6 mm to 2.0 mm, in particular 1.6 mm, from the level of the tread depth Tp in the radial direction (1.6 mm corresponds to the currently smallest legally prescribed minimum tread depth in the EU countries). As Fig. 3 further shows, subsections 7b 11 , viewed in plan view, elongated rectangular or elongated trapezoidal. The subsections 7b" each have a symmetry plane E2 running in the radial direction as well as in their longitudinal extent, wherein the symmetry planes E2 of all subsections 7b" meet the symmetry plane Ei at the circle center Pi, and furthermore each have a length 02 of 2.0 mm to 3.0 mm, determined along the associated symmetry plane E2. According to Fig. 5, each subsection 7b" is shallower in the radial direction than the subsection 7b 1, wherein the incision base 9 in the area of ​​the subsections 7b" is inclined to the radial direction in such a way that each subsection 7b" in the direction of the subsection 7b 1 continuously gets deeper.

[0040] As Fig. 3 further shows, the inner incision section 8b, viewed in plan view, has a plane of symmetry Es, which runs perpendicular to the incision base line LEB and in the radial direction, and is composed, also viewed in plan view, of four subsections 8b 1 , which run along four edges of a hexagon, in particular a regular hexagon, and three branched subsections 8b" on the outside of the hexagon, each adjoining a corner area of ​​the hexagon, and has a correspondingly branched center line mb. The subsection 8b 1runs from the edge-side incision section 8a in the direction of the incoming block edge 5a (Fig. 2) and back to the incision base line LEB and has a length C3 of 3.0 mm to 5.0 mm measured along the connecting line v and related to the center line mb.

[0041] The subsections 8b" are, viewed in plan view, each Y-shaped, with the Y-trunk continuing between the Y-branches, each have a plane of symmetry E4 running in the radial direction and a length C4 determined along the plane of symmetry E4 of 2.0 mm to 3.0 mm. According to Fig. 6, the inner incision section 8b - measured from the incision base 9 - has a distance at>' from the level of the tread depth Tp in the radial direction of 3.0 mm to 4.5 mm, in particular of 3.0 mm or 4.0 mm (3.0 mm or 4.0 mm corresponds to the legally prescribed minimum tread depth for winter tires in some EU countries).

[0042] As Fig. 3 shows, the design of the cuts 7, 8 is further such that the free end of the subsection 7b 1 , 8b 1 in the area between the two ends of the other subsection 7b 1 , 8b 1 lies.

[0043] The invention is not limited to the described embodiment.

[0044] The incisions can also be formed in circumferential direction around tread ribs and can traverse the respective positive tread (tread rib, tread block). The incisions each have at least one incision section which serves as a wear indicator and is symbolically designed in plan view. The incision section(s) which is / are not symbolically designed can, viewed in plan view, in particular be straight, curved, wavy, or curved and wavy. Furthermore, incisions with several incisions, in particular with two, serving as abrasion indicators can be provided. The maximum depth of the incisions is at least the tread depth reduced by 4.5 mm. The tread does not have to be directional.

[0045] List of reference symbols

[0046] 1 diagonal groove

[0047] 2nd groove 3 short groove

[0048] 4 middle tread block

[0049] 4a incoming block edge

[0050] 4b tapered block edge

[0051] 4c Block outer surface 5 semi-central profile block

[0052] 5a incoming block edge

[0053] 5b tapered block edge

[0054] 5c Block outer surface

[0055] 6 shoulder-side profile block 6a incoming block edge

[0056] 6b tapered block edge

[0057] 6c Block outer surface

[0058] 7 incision

[0059] 7a edge-side incision section 7b inside incision section

[0060] 7b 1 , 7b" subsection

[0061] 8 incision

[0062] 8a marginal incision section

[0063] 8b inside incision section 8b 1 , 8b" subsection

[0064] 9 Incision reason

[0065] 10 cutting wall

[0066] AA line (tyre equatorial plane) ab, ab , a v Distance bE Width ci, C2, C3, C4 ....Length

[0067] Ei, E2, ES, E4.. Symmetry plane LEB incision baseline m a , mb center line

[0068] Pi center of circle

[0069] R arrow (rolling direction) S5, Se arrow (viewing direction) tE maximum depth tER > . depth

[0070] Tp Profile depth v Connecting line Z2, Z3 Detail a Angle

Claims

Patent claims 1. Vehicle pneumatic tires with a tread having profile positives (4, 5, 6) bounded by grooves (1, 2, 3), wherein profile positives (5) are provided which are provided with incisions (7, 8) extending at least partially at an angle (a) of 0° to 50° to the axial direction in plan view, having a width (b) of 0.4 mm to 1.6 mm and a depth (t) at the deepest point which is at least the tread depth (Tp) reduced by 4.5 mm and at most 100% of the tread depth (Tp), wherein the incisions (7, 8) each form at least one wear indicator (7b, 8b), characterized in that the wear indicator (7b, 8b) is formed by a section (7b, 8b) of the incision (7, 8) having the shape of a sun symbol or a snowflake symbol in plan view. is.

2. Vehicle pneumatic tire according to claim 1, characterized in that the cut section (7b, 8b) extends to the cut base (9) of the cut (7, 8) while maintaining its shape.

3. Vehicle pneumatic tire according to claim 1 or 2, characterized in that the cut section (7b, 8b) ends at a distance in the radial direction from the level of the depth (t) at the deepest point of the cut (7, 8).

4. Vehicle pneumatic tire according to one of claims 1 to 3, characterized in that the cut section (7b, 8b) to the level of the tread depth (Tp) has a radially determined distance (ab) of 1.6 mm to 4.5 mm.

5. Vehicle pneumatic tire according to one of claims 1 to 4, characterized in that the cut section (7b) having the shape of a sun symbol to the level of the tread depth (Tp) has a radially determined distance (ab) of 1.6 mm to 2.0 mm, in particular of 1.6 mm or of 2.0 mm.

6. Vehicle pneumatic tire according to one of claims 1 to 5, characterized in that the cut section (7b) having the shape of a sun symbol is divided by a first subsection (7b) extending over a circular arc, in particular over a circular arc of a semicircle. 1 ) and at least three, in particular four, from the outside of the circular arc of the first subsection (7b 1 ) outgoing, elongated and radially extending, second subsections (7b 11 ) is formed.

7. Vehicle pneumatic tire according to claim 6, characterized in that the second subsections (7b 11) are executed more shallowly than the first subsection (7b 1 ), wherein the cut base (9) is in the area of ​​the second subsections (7b 11 ) is inclined to the radial direction such that every second subsection (7b 11 ) towards the first subsection (7b 1 ) becomes continuously deeper.

8. Vehicle pneumatic tire according to one of claims 1 to 7, characterized in that the cut section (8b) having the shape of a snowflake symbol has a radially determined distance (ab) of 3.0 mm to 4.5 mm, in particular of 3.0 mm or of 4.0 mm, to the level of the tread depth (TP).

9. Vehicle pneumatic tire according to claim 8, characterized in that the cut section (8b) having the shape of a snowflake symbol comprises at least three, in particular four, first subsections (8b) extending along edges of a hexagon, in particular a regular hexagon.1 ) and from the mutual connection points of the first subsections (8b 1 ) outgoing, branching, second subsections (8b 11 ) is formed.

10. Vehicle pneumatic tire according to claim 9, characterized in that the branched, second subsections (8b"), viewed in plan view, are each Y-shaped, wherein the Y-stem is connected to the mutual connection point of two first subsections (8b 1 ) connects and wherein the Y-stem is preferably continued between the Y-branches.

11. Vehicle pneumatic tire according to one of claims 1 to 10, characterized in that the cut section (7b, 8b), viewed in top view, has one, in particular exactly one, plane of symmetry (Ei , Es).

12. Vehicle pneumatic tire according to one of claims 1 to 11, characterized in that the cut section (7b, 8b) does not open into any groove (1 , 2, 3).

13. Vehicle pneumatic tire according to claim 12, characterized in that incisions (7, 8) are provided in pairs in the same profile positive (5), wherein one incision (7) has the incision section (7b) having the shape of a sun symbol and the other incision (8) has the incision section (8b) having the shape of a snowflake symbol, wherein the incisions (7, 8) are formed in pairs such that the incision sections (7b, 8b) are at least partially opposite each other.

14. Vehicle pneumatic tire according to claim 13, characterized in that the incisions (7, 8) each consist of the incision section (7a, 7b) having the shape of a sun symbol or a snowflake symbol and a further incision section (7a, 8a), in particular each opening into a groove (3), wherein the further incision sections (7a, 8a), viewed from above, preferably run in alignment with each other.

Images