Tread and vehicle tyre with good snow and noise properties

Abstract

The invention relates to a tread (1) for a vehicle tyre (2), wherein a shoulder-side profile block row (3) and a semi-central profile block row (4) are formed in the tread (1), wherein the two profile block rows (3, 4) are separated from one another by a zigzagging circumferential groove (5), and wherein transverse and / or oblique grooves (6, 7, 8, 9, 10) are formed in the two profile block rows (3, 4). A maximum number of transverse and / or oblique grooves (6, 7, 8, 9, 10) intersected by a closed circumferential line in the semi-central profile block row (4) is greater than in the shoulder-side profile block row (3), wherein supplementary oblique grooves (9, 10) in the semi-central profile block row (4) each enclose average angles in a range between 10° and 45° with an axial direction (A).

Description

[0001] 202406035

[0002] Treads and vehicle tires with good snow and noise characteristics

[0003] Description

[0004] The invention relates to a tread for a vehicle tire, wherein a shoulder-side profile block row and a semi-central profile block row are formed in the tread, wherein the two profile block rows are separated from each other by a zigzag-shaped circumferential groove and wherein transverse and / or oblique grooves are formed in both profile block rows.

[0005] The treads of vehicle tires are typically provided with treads, which in particular include grooves that can divide the tread into ribs and / or blocks. It is common to categorize ribs and blocks into shoulder, mid-center, and center profile elements. In particular, the edge of a contact patch can run through shoulder profile blocks or ribs, with mid-center profile blocks and ribs being arranged axially within the shoulder profile elements, and center profile blocks and ribs being located closest to the tire's equator. Circumferential grooves are often the most defining tread pattern. It is known to give circumferential grooves a zigzag shape, which can, for example, improve the traction of a tire on winter road surfaces and / or on loose surfaces.

[0006] One problem with the arrangement of transverse and / or diagonal grooves is that while a higher number of these lateral elements improves grip in wet and snowy conditions, it comes at the cost of stability. Stability and stiffness are particularly important in the tire shoulder and the adjacent mid-tread block row. For this reason, continuous handling ribs are sometimes incorporated in the tire shoulder or mid-tread. Alternatively, mid-tread blocks can be grouped into composite blocks to increase circumferential and lateral stiffness. However, the number of lateral elements in the circumferential direction

[0007] Internal 202406035 also has an effect on the frequency of the rolling noise, whereby longer profile blocks in the circumferential direction lead to lower frequencies, which in turn can be perceived as particularly disturbing.

[0008] The invention is based on the objective of creating a tread and vehicle tire with good traction, especially on snow, which at the same time has high stiffness and optimized noise characteristics.

[0009] The object is achieved according to the invention by having a maximum number of transverse and / or oblique grooves cut by a closed circumferential line in the semi-central profile block row greater than in the shoulder-side profile block row, wherein additional oblique grooves in the semi-central profile block row each enclose average angles in a range between 10° and 45° with an axial direction.

[0010] The invention provides a specific way to arrange negative volumes in the sensitive axial area of ​​the shoulder and midsection in such a way that the multidimensional conflict of objectives is optimally resolved. Here, the shoulder is stabilized by a smaller number of transverse and / or inclined grooves compared to the midsection, with the negative volume in the midsection profile block row being arranged in the form of specifically oriented inclined grooves optimized for noise characteristics and stiffness.

[0011] Transverse grooves are tread grooves that extend primarily in a transverse direction. Diagonal grooves are tread grooves that extend at an angle to the transverse direction. A tread groove has a width of at least 2 mm. In addition to tread grooves, sipes, also known as grooves, may be formed in the tread. Sipes have a width of less than 2 mm and may be characterized by the fact that they close within the contact patch under tire load.

[0012] Internal 202406035

[0013] In this text, the terms axial, radial, and circumferential refer to the tread or tire as intended on a vehicle tire and its rolling motion. Radial direction refers to a direction perpendicular to and intersecting the tire's axis of rotation. Radially inward refers to the orientation facing radially toward the axis of rotation. Radially outward refers to the orientation facing radially away from the axis of rotation. Circumferential direction describes the direction of rolling motion around the axis of rotation.A tire positioned at the front of the circumference reaches a minimum distance to the road surface earlier during a 180° rotation of the tire when the vehicle is traveling forward than a tire positioned at the rear. The axial direction refers to a direction parallel to the axis of rotation. "Axially inward" refers to an orientation that is axially aligned with a tire equator, a tire equator plane, or a tire equator line. The tire equator plane is a plane perpendicular to the tire's axis of rotation that passes through the center of the tire's axial width, with the tire equator line lying within the tire equator plane and on the tire's surface. The lateral direction is defined as a direction consisting of components of the radial and / or axial directions.

[0014] The axial edges of a ground contact area can be arranged in the axial regions of the shoulder-side profile block rows. The ground contact area can correspond to the statically determined footprint at a load of 70% of the maximum bearing capacity and an internal pressure of 85%, determined according to ETRTO standards.

[0015] All described features refer specifically to the new condition of the tread. The effects achieved with the features of the main claim

[0016] Internal 202406035 can be supported and further enhanced by preferred embodiments and configurations.

[0017] The maximum number of transverse and / or oblique grooves intersected by a closed perimeter line in a profile block row can be determined by shifting the imaginary closed perimeter line axially within the profile block row until the maximum number is found. In a profile block row where all negative elements running in the transverse or oblique direction traverse the entire axial width of the profile block row, the maximum number is given everywhere.

[0018] The additional diagonal grooves are included in the total number of transverse and / or diagonal grooves in the semi-central profile block row within the meaning of the invention.

[0019] The supplementary inclined grooves can follow straight, curved, swerved, or angled paths. Preferably, the supplementary inclined grooves run straight or slightly curved, for example, with radii of curvature of at least 10 mm. An average angle that a supplementary inclined groove forms with the axial direction in the semi-central profile block row can be determined by measuring a straight line segment between two endpoints of the supplementary inclined groove. Alternatively, local angles of inclination along the supplementary inclined groove can be determined and their average calculated.

[0020] According to a preferred embodiment, the additional inclined grooves have a shallower depth than the transverse and / or inclined grooves in the shoulder-side profile block row. Alternatively or additionally, the additional inclined grooves can have a shallower depth than other transverse and / or inclined grooves in the mid-center profile block row. The additional inclined grooves can have a depth in a range between 15% and 93%, or, according to preferred embodiments, between 50% and 93% of a full profile depth. This provides good stability to the mid-center profile block row despite the higher number of transverse and / or inclined grooves compared to the shoulder.

[0021] Internal 202406035

[0022] A first supplementary inclined groove can completely traverse a profile block in the semi-central profile block row, while a second supplementary inclined groove can partially traverse a profile block in the semi-central profile block row and terminate with one end within the profile block. This allows for a good balance between traction and drainage on the one hand, and stability and noise optimization on the other.

[0023] The first supplementary inclined groove can have a shallower depth than the second supplementary inclined groove. For the same groove depth, a groove ending as a sag groove in a profile block affects the stability of the profile block to a lesser extent than a continuous groove. A second supplementary inclined groove designed as a sag groove can therefore be deeper than a first supplementary inclined groove that completely traverses the profile block, with the result that both supplementary inclined grooves have a comparable effect on the stiffness of the profile block. In particular, the first supplementary inclined groove can have a depth in the range of 50% to 78% of the full profile depth, while the second supplementary inclined groove can have a depth in the range of 83% to 93% of the full profile depth.

[0024] According to a preferred embodiment, the additional inclined grooves enclose angles in a range between 15° and 45°, preferably between 20° and 45°, with an axial direction. This limitation of the angular range towards a greater circumferential proportion further improves noise performance. In addition, the circumferential stiffness can be improved in this way.

[0025] The additional inclined grooves can have an opposite inclination direction to other transverse or inclined grooves in the semi-central profile block row, or the other transverse or inclined grooves can run parallel to the axial direction. Due to the differing inclination directions of the lateral grooves in the semi-central profile block row in the circumferential direction,

[0026] Internal 202406035, despite the adjacent zigzag circumferential groove, as many transverse and / or oblique grooves as possible should be placed in the profile block row without jeopardizing the stability of the tread by using profile blocks or profile block sections that are too narrow in the circumferential direction.

[0027] A central row of profile blocks can be formed in the tread, axially enclosing the semi-central row of profile blocks together with the shoulder-side row of profile blocks. The central row of profile blocks and the semi-central row of profile blocks are separated from each other by a further zigzag-shaped circumferential groove. A first transverse or oblique groove in the shoulder-side row of profile blocks can be an extension of a second transverse or oblique groove in the central row of profile blocks. Two grooves are considered to be extensions of each other if an extrapolation of the longitudinal path of one groove coincides with the longitudinal path of the other groove and vice versa, and / or if the longitudinal paths of the two grooves can be described by a spline function. The two grooves can be extensions of each other with or without a gap between them.According to a preferred embodiment, no profile groove is formed in the semi-central profile block row along an imaginary connecting line between the first and second transverse or inclined groove, thus creating a composite block in the semi-central profile block row. This provides stability and advantageous noise characteristics to the semi-central section, while traction and drainage capacity are ensured by the skillful placement of transverse and / or inclined grooves in the composite block, in particular the placement of the additional inclined grooves in the composite block.

[0028] The first and second transverse or oblique grooves can each merge into a short zigzag segment of the circumferential grooves at an angle of less than 45° and preferably in a substantially parallel manner, so that the composite block assumes an eight-sided s-shape, formed on two sides by short zigzag segments of the circumferential grooves and on four sides by long

[0029] Internal 202406035

[0030] Zigzag segments of the circumferential grooves and on two sides is bordered by further transverse or oblique grooves in the semi-central profile block row.

[0031] The composite block can have two additional diagonal grooves. Several composite blocks of the described type can be formed, in particular one composite block per pitch of the tread profile, wherein the composite blocks are separated from each other by further transverse and / or diagonal grooves, and wherein each of the composite blocks has two additional diagonal grooves. In this way, for each pitch, two additional diagonal grooves correspond to the first transverse or diagonal groove in the shoulder-side profile row and the second transverse and / or diagonal groove in the middle profile block row, so that the maximum number of transverse and / or diagonal grooves intersected by a closed circumferential line in the mid-center profile block row is greater by the number of pitches in the profile than in the shoulder-side profile block row.

[0032] The tread pattern can comprise 25 to 45 pitches, particularly 30 to 40 pitches, which can be scaled within a standard pitch length variation. The length and angle of the zigzag segments, as well as the angled groove, can also vary within a standard range along with the pitch length variation.

[0033] The two additional inclined grooves can be arranged in such a way that the composite block is divided into three essentially equal areas. This achieves an optimal stiffness distribution.

[0034] The tread may have incisions, preferably at least one incision per profile block and more preferably at least two incisions per profile block. In particular, more than two incisions may be provided per composite block in the semi-central row of profile blocks. The incisions in the composite blocks may run essentially parallel to the supplementary inclined grooves, which allows for a particularly efficient arrangement of the profile negative in the composite blocks.

[0035] Internal 202406035

[0036] The long zigzag segments of the circumferential groove between the shoulder-side profile block row and the mid-center profile block row can extend circumferentially over two shoulder-side profile blocks each. This can be achieved by positioning every second shoulder profile block axially offset from a circumferentially adjacent shoulder profile block, and every other second shoulder profile block as an extension of the adjacent shoulder profile block. This corresponding extension of the zigzag segment improves the flow characteristics. Furthermore, reducing the number of zigzag corners can benefit the tread's noise characteristics.

[0037] Alternatively or additionally, the long zigzag segments of the further circumferential groove between the semi-central profile block row and the central profile block row can extend circumferentially over a central profile block. This can be achieved by arranging each central profile block axially offset from a central profile block adjacent in the circumferential direction. Such short zigzag segments and the correspondingly high number of corners create high traction.

[0038] According to a particularly preferred embodiment, the circumferential groove comprises zigzag segments with angles in a range between 5° and 15° relative to the circumferential direction, wherein preferably every second zigzag segment is oriented at such an angle. A zigzag segment is a straight section or at least a substantially straight section compared to the corners of the zigzag pattern. A zigzag pattern can result from a sequence of a pair of two zigzag segments having different angles of extension and connected to each other at a corner. Adjoining zigzag segments can enclose angles in a range of 90° to 135° with each other. The angle range of 5° to

[0039] Internal 202406035

[0040] A 15° angle to the circumferential direction can provide a good compromise between additional traction and drainage capacity.

[0041] The zigzag shape of the circumferential groove can be so pronounced that a closed circumferential line cannot be drawn through its volume. In other words, the circumferential groove can be designed in such a way that it is impossible to see through it in the circumferential direction because the view is obstructed by the groove walls, which are inclined relative to the circumferential direction due to the zigzag shape. This ensures a particularly high degree of traction.

[0042] The shoulder-side tread block row, the mid-center tread block row, and optionally the middle tread block row can be provided on the inside and / or outside of the tire. The inside of the tire is the side of the tire or tread that, when the tire is mounted on a vehicle as intended, faces inwards, i.e., towards the tire mounted parallel to the respective axle, with the outside of the tire being opposite the inside. The tread pattern of a tire with a dedicated inside and outside, or a tread pattern with a tread pattern, is also referred to as asymmetric. Preferably, the tread block rows according to the invention are provided on the outside of the tire; here, particularly high demands are placed on the stiffness of the tread in order to give the tire good handling characteristics.

[0043] The present invention further relates to a vehicle tire comprising a tread according to the invention, preferably a tread as preferably described in the present text. Vehicle tires designed according to the invention are tires of any construction, in particular radial tires, and tires of any type, in particular pneumatic tires for motor vehicles such as passenger cars, light trucks, or commercial vehicles. Vehicle tires according to the invention can be designed for rim sizes in a range between 13 inches and 24 inches.

[0044] Internal 202406035

[0045] The vehicle tire may exhibit special winter suitability according to the "Three Peak Mountain Snow Flake" (3PMS) standard. This is certified by a 3PMS marking on a sidewall of the tire, which may be embossed into the sidewall material. The tread pattern described above and below can contribute to winter suitability; additionally, a suitable rubber compound can contribute to winter suitability, particularly in synergistic interaction with the tread pattern.

[0046] The tread can be further developed with additional features, which are described in connection with the vehicle tire according to the invention. The vehicle tire according to the invention can be further developed with additional features, which are described in connection with the tread according to the invention.

[0047] The invention is described below by way of example with reference to the accompanying drawings and advantageous embodiments. The drawings show:

[0048] Figure 1 schematically and in part shows a side view of an embodiment of a vehicle tire according to the invention,

[0049] Figure 2 schematically and in part shows a top view of an embodiment of a running track according to the invention.

[0050] Figure 1 shows a highly schematic side view of a vehicle tire 2, wherein an embodiment of a tread 1 according to the invention can be arranged on the outside in the radial direction R.

[0051] Figure 2 shows a partial embodiment of an embodiment according to the invention.

[0052] Running track 1 in a top view, wherein the axial direction A and the

[0053] The circumferential direction U is indicated by arrows. The section shows the

[0054] Internal 202406035 entire width of the tread 1, between a first and a second axial profile edge. The embodiment shown relates to an asymmetric tread 1, wherein the side intended for the outside of the tire 2 is shown on the left in the drawing. On the outer half, the tread 1 comprises a shoulder-side profile block row 3 arranged circumferentially U, a semi-central profile block row 4, and a central profile block row 11. The profile blocks of the rows 3, 4, 11 are arranged axially A offset from one another such that zigzag-shaped circumferential grooves 5, 14 are formed. In the shoulder-side circumferential groove 5, long zigzag segments 15 extend over two shoulder-side profile blocks or between two transverse grooves 7 over a first transverse groove 6.In the further circumferential groove 14, further in the axial center, long zigzag segments extend only over one profile block of the middle profile block row 11, resulting in a shorter-wave zigzag pattern compared to the circumferential groove 5.

[0055] The first transverse groove 6 leads into a short zigzag segment of the circumferential groove 5. A second oblique groove 12, formed in the central profile block row 11, leads into a short zigzag segment of the further circumferential groove 14. Between the first transverse and the second oblique groove 6, 12, no transverse or oblique groove extends in the semi-central profile block row 4. In this way, composite blocks 13 are formed, with the S-shaped outline of one of these composite blocks 13 highlighted in Figure 2 by a thick solid line. Two additional oblique grooves 9, 10 are formed in the composite block 13, the first additional oblique groove 9 extending axially completely through the composite block 13 and the second additional oblique groove 10 ending as a pocket groove in the block 13. The additional inclined grooves 9, 10 have an inclination opposite to that of the further inclined grooves 8 in the semi-central profile block row 4.This allows for the definition of three block sections that are thicker in the circumferential direction U than would have been possible with a uniform orientation of the grooves 8, 9, 10. In the example shown, the additional oblique grooves 9, 10 form angles of approximately 26° with the axial direction.

[0056] Internal 202406035

[0057] The described features are qualitatively repeated in every pitch, although minor deviations within the range of typical pitch variations are possible. Pitch lengths are indicated by double-pointed arrows in Figure 2. Incisions 16 are formed in the profile blocks, which are shown only as lines in Figure 2. The orientation of the incisions 16 in the semi-central composite blocks 13 is preferably parallel to the orientation of the supplementary diagonal grooves 9, 10, as shown in Figure 2, whereby the lamellae 16 in the shoulder-side profile block row 3 can run parallel to the transverse grooves 6, 7. The angular orientation of the incisions 16 in the composite blocks 13 allows for more incisions 16 per block 13 than with a substantially transverse orientation, as provided in the shoulder-side profile block row 3, without unduly impairing the stiffness of the blocks 13.

[0058] Internal 202406035

[0059] Reference symbol list

[0060] 1 tread

[0061] 2 vehicle tires 3 shoulder-side tread block row

[0062] 4 semi-central profile block rows

[0063] 5 zigzag-shaped circumferential grooves

[0064] 6 first transverse or diagonal groove (of the shoulder-side profile block row)

[0065] 7 Transverse or diagonal groove of the shoulder-side profile block row 8 further transverse or diagonal groove (of the semi-central profile block row)

[0066] 9 first supplementary slant groove (of the semi-central profile block row)

[0067] 10 second supplementary diagonal groove (of the semi-central profile block row)

[0068] 11 middle profile block row

[0069] 12 Second transverse or diagonal groove (of the middle profile block row) 13 Profile block, composite block (of the semi-central profile block row)

[0070] 14 more zigzag-shaped circumferential grooves

[0071] 15 long zigzag segment of the circumferential groove 5

[0072] 16 cut

[0073] A Axial direction R Radial direction

[0074] U circumferential direction

[0075] Internal

Claims

202406035 Patent claims 1. Tread (1 ) for a vehicle tire (2), wherein the tread (1 ) has a shoulder-side tread block row (3) and a semi-central tread block row (4), wherein the two tread block rows (3, 4) are separated from each other by a zigzag circumferential groove (5) and wherein transverse and / or oblique grooves (6, 7, 8, 9, 10) are formed in both tread block rows (3, 4), characterized in that a maximum number of transverse and / or oblique grooves (6, 7, 8, 9, 10) intersected by a closed circumferential line in the semi-central tread block row (4) is greater than in the shoulder-side tread block row (3), wherein supplementary oblique grooves (9, 10) in the semi-central tread block row (4) each enclose average angles in a range between 10° and 45° with an axial direction (A).

2. Tread (1 ) according to claim 1 , characterized in that the additional oblique grooves (9, 10) have a shallower depth compared to the transverse and / or oblique grooves (6, 7) in the shoulder-side profile block row (3).

3. Tread (1 ) according to one of claims 1 or 2, characterized in that a first supplementary inclined groove (9) completely traverses a profile block (13) in the semi-central profile block row (4), wherein a second supplementary inclined groove (10) incompletely traverses a profile block in the semi-central profile block row (4) and terminates with one end in the profile block (13).

4. Tread (1 ) according to claim 3, characterized in that the first supplementary oblique groove (9) has a lesser radial depth than the second supplementary oblique groove (10).

5. Tread (1) according to one of claims 1 to 4, characterized in that the additional inclined grooves (9, 10) have angles in a range between 15° Internal 202406035 and 45°, preferably between 20° and 45° with an axial direction (A) 6. Tread (1 ) according to one of claims 1 to 5, characterized in that the additional inclined grooves (9, 10) have an opposite inclination direction to further transverse or inclined grooves (8) in the semi-central profile block row (4) or that the further transverse or inclined grooves (8) run parallel to the axial direction (A).

7. Running strip (1 ) according to one of claims 1 to 6, characterized in that a central profile block row (11 ) is formed in the running strip (1 ), which axially encloses the semi-central profile block row (4) together with the shoulder-side profile block row (3), wherein the central profile block row (11 ) and the semi-central profile block row (4) are separated from each other by a further zigzag-shaped circumferential groove (14), wherein a first transverse or oblique groove (6) in the shoulder-side profile block row (3) is formed in extension to a second transverse or oblique groove (12) in the central profile block row (11 ), wherein no profile groove is formed in the semi-central profile block row (4) along an imaginary connecting line between the first and second transverse or oblique groove (6, 12), so that a composite block (13) is formed in the semi-central profile block row (4).

8. Tread (1 ) according to claim 7, characterized in that the first and the second transverse or oblique groove (6, 12) each merge into a short zigzag segment of the circumferential grooves (5, 14) at an angle deviation of less than 45°, so that the composite block (13) assumes an eight-sided s-shape, which is bounded on two sides by short zigzag segments of the circumferential grooves (5, 14), on four sides by long zigzag segments of the circumferential grooves (5, 14) and on two sides by further transverse or oblique grooves (8) in the semi-central profile block row (4). Internal 202406035 9. Tread (1 ) according to one of claims 7 to 8, characterized in that the long zigzag segments (15) of the circumferential groove (5) between the shoulder-side profile block row (3) and the semi-central profile block row (4) extend in circumferential direction (U) over two shoulder-side profile blocks each and / or that the long zigzag segments of the further circumferential groove (14) between the semi-central profile block row (4) and the central profile block row (11 ) extend in circumferential direction (U) over one central profile block each.

10. Running strip (1 ) according to one of claims 7 to 9, characterized in that two additional inclined grooves (9, 10) are formed in the composite block (13).

11. Tread strip (1 ) according to claim 10, characterized in that the two additional inclined grooves (9, 10) are arranged such that the composite block (13) is divided into three substantially equal areas by the additional inclined grooves (9, 10).

12. Tread (1 ) according to one of claims 1 to 11 , characterized in that incisions (16) are formed in the tread, wherein preferably at least one incision (16) is formed per profile block and further preferably at least two incisions (8) are formed per profile block.

13. Vehicle tire (2) comprising a tread (1) according to any one of claims 1 to 12.

14. Vehicle tire (2) according to claim 13, characterized in that the tread (1 ) is asymmetrical and that the shoulder-side profile block row (3) is provided on an outer side of the tire. Internal 202406035 15. Vehicle tire (2) according to one of claims 13 or 14, characterized in that a 3PMS marking is formed on a sidewall of the vehicle tire (2), thereby certifying the vehicle tire (2) as having special winter suitability in accordance with the “Three Peak Mountain Snow Flake” standard. Internal

Images