Vehicle tires

Abstract

Vehicle tires with a tread featuring profile positives, such as profile blocks (1) or profile ribs, with cuts (4) having two radially extending cut walls (5, 5') which have a mutually constant distance from each other, corresponding to the cut width (b1), of 0.30 mm to 1.50 mm, in particular 0.40 mm to 1.00 mm, wherein each cut wall (5, 5') is provided with a structure of parallel microgrooves (6) and bridges (7) located at the level of the cut walls (5, 5') between the microgrooves (6), wherein the microgrooves (6) have a depth (t2) determined perpendicular to the cut walls (5, 5') of 0.10 mm to 1.00 mm and a width (b2) determined at the level of the cut walls (5, 5') of 0.10 mm to 1.00 mm, and wherein the structures the microgrooves (6) and bridges (7) on the two incision walls (5, 5') are identical and consist of microgrooves (6) of the same dimensions. The microgrooves (6) on one incision wall (5) run parallel to the microgrooves (6) on the opposite incision wall (5').

Description

[0001] The invention relates to a vehicle tire with a tread featuring profile positives, such as profile blocks or profile ribs, with cuts having two radially extending cut walls, which have a mutually constant distance to each other, corresponding to the cut width, of 0.30 mm to 1.50 mm, in particular 0.40 mm to 1.00 mm, wherein each cut wall is provided with a structure of parallel microgrooves and bridges located at the level of the cut walls between the microgrooves, wherein the microgrooves have a depth of 0.10 mm to 1.00 mm determined perpendicular to the cut walls and a width of 0.10 mm to 1.00 mm determined at the level of the cut walls, and wherein the structures of the microgrooves and bridges on the two cut walls are identical and consist of microgrooves of the same dimensions.

[0002] Such a vehicle tire is known from US Patent 6,116,310 B. This vehicle tire has tread features, such as tread blocks, with cuts extending to a depth of up to 9.50 mm, each cut wall having a structure of parallel microgrooves and bridges between them. The microgrooves are all identical in design and are arranged in the same way on one cut wall as on the other, with the microgrooves on each cut wall running at an acute angle to the radial direction and intersecting each other. Cuts with such cut walls are intended to ensure good tread performance in wet conditions and good performance on ice, while maintaining edge effects and block stiffness. This is achieved, in particular, by the cut walls bearing against each other under braking or traction loads.

[0003] From JP H08258515 A, a vehicle tire is known whose tread is divided into profile blocks by circumferential grooves and transverse grooves. Each of these blocks has at least one cut, the walls of which are characterized by a multitude of irregularities across their entire surface. These irregularities are individual protrusions and / or depressions with a height or depth of at least 50 µm and up to 200 µm. This is intended to prevent the cut walls from sticking together during demolding of a tire whose tread is made of a foamed rubber material after vulcanization.

[0004] EP 3 441 241 A1 discloses a vehicle tire with a tread featuring profile positives, such as tread blocks or ribs, which are provided with cuts with a width of 0.40 mm to 0.80 mm, wherein at least one projection is formed on one cut wall, locally narrowing the respective cut, and a corresponding recess is formed on the other cut wall for each projection. The tread is directional, so that the leading edge of the cut, at the periphery of the tread, is the first to engage the road surface when the tire rolls forward. The projection on one cut wall is offset radially relative to its corresponding recess on the other cut wall, with the projection or recess located on the cut wall extending from the leading edge being offset from the recess or projection located on the other cut wall.which is located on the cut wall extending from the tapered cut edge, is formed deeper inside the cut. This offset of the projections causes them to interlock under load, thus counteracting undesirable deformation of the profile positive.

[0005] The invention is based on the objective of designing a vehicle tire of the type mentioned at the outset in such a way that mutual contact takes place between the cut walls of cuts in the tread under load, which causes a particularly effective increase in the frictional energy between the cut walls and therefore counteracts deformation of the profile positive under load particularly well.

[0006] The problem set out in the invention is solved by the fact that the microgrooves on one incision wall run parallel to the microgrooves on the opposite incision wall.

[0007] According to the invention, the microgrooves running parallel to each other on the two cut walls counteract deformation of the profile positives particularly effectively under load when in contact with each other, especially due to the resulting high frictional energy and the possibility of mutual interlocking or mutual engagement of the structure of microgrooves and bridges between the microgrooves.

[0008] In a preferred embodiment, the depth of the microgrooves is 0.20 mm to 0.50 mm, preferably up to 0.30 mm. The width of the microgrooves, determined at the level of the cut walls, is preferably also 0.20 mm to 0.50 mm, more preferably up to 0.30 mm. It is particularly advantageous if the bridges located between the successive microgrooves have a width of 0.05 mm to 1.00 mm, more particularly 0.10 mm to 0.50 mm, preferably up to 0.30 mm, at the level of the cut walls. In preferred embodiments, the structure of microgrooves and bridges is therefore very small or even minute and thus particularly well suited to generating a very high frictional energy between the cut walls under load.

[0009] Particularly advantageous are structural designs in which the microgrooves and bridges are both curved in cross-section and are designed to connect directly to one another. Thus, a curved bridge follows a curved microgroove, with the bridges being present only at points at the level of the cut walls in cross-section. It is precisely in this embodiment that a particularly high frictional energy can occur between the cut walls.

[0010] In another preferred embodiment, the microgrooves provided on one cut wall are opposite those formed on the other cut wall. In an alternative, also preferred embodiment, the microgrooves on one cut wall are offset from the microgrooves on the other cut wall, with, for example, the microgrooves on one cut wall being opposite the bridges on the other cut wall. In all these variants, depending on the load occurring on the tread when the tire rolls on the road surface, bridges on one cut wall can engage with microgrooves on the other cut wall. This depends, among other things, on whether the forces acting under load are due to traction or braking and in what position the profile positives are located in the tread.

[0011] There are numerous ways to design the microgrooves with respect to their cross-sectional shape in order to influence the extent of the frictional energy generated between the cut walls.

[0012] In a preferred embodiment, the microgrooves have a U-shaped cross-section with a bottom running parallel to the incision walls and two groove flanks running at right angles to the incision walls.

[0013] In another preferred embodiment, the microgrooves have an arc-shaped or dome-shaped cross-section, in particular along a circular arc, for example a semicircle, or the microgrooves have a triangular or triangular-like cross-section.

[0014] Furthermore, for particularly effective frictional energy between the incision walls, it is advantageous if the number of microgrooves per incision wall is five to one hundred, especially ten to fifty.

[0015] Regarding the course of the microgrooves and bridges across the incision walls, a variety of options are available, in particular those mentioned below.

[0016] Particularly preferred are embodiments in which the microgrooves run straight and parallel to the periphery of the tread or at an angle of up to 90° to the periphery of the tread. The microgrooves can also extend in an arc shape across the entire length of the cut wall. In another preferred embodiment, the structure of microgrooves and bridges on each cut wall consists of several strips, preferably with a constant width of 3.00 mm to 10.00 mm.

[0017] Depending on their course across the cut walls, the microgrooves and bridges can extend to the periphery of the tread and to the points where the cuts merge into grooves on the positive profile flanks. A preferred embodiment is one in which the cut walls are free of the microgroove and bridge structure for a section immediately adjacent to the periphery of the tread and the bottom of the cut, with a width of at least 0.50 mm and, in particular, 1.00 mm.

[0018] Further features, advantages and details of the invention will now be described in more detail with reference to the schematic drawing, which illustrates an exemplary embodiment. Fig. 1. An oblique view of profile blocks of a tread of a vehicle tire, Fig. 2 a sectional view along the line II-II in Fig. 1 marked cutting plane, Fig. 3 to Fig. 7 further embodiments of the invention, each based on a section of the cross-section of a cut, otherwise analogous to Fig. 2, and Fig. 8 to Fig. 10 top views of a cut wall with different design variants of the microgroove pattern.

[0019] Vehicle tires according to the invention are tires for motor vehicles, in particular for multi-track motor vehicles, preferably for passenger cars (PCs), vans (transporters), SUVs, trucks (lorries) or buses, especially preferably radial pneumatic tires.

[0020] Fig. Figure 1 shows two profile blocks 1 belonging to a central or semi-central row of profile blocks in the tread of a vehicle tire. The rows of profile blocks are laterally bounded by indicated circumferential grooves 2, which largely exhibit the intended tread depth. Transverse grooves 3 are present between the circumferentially successive profile blocks 1, which are oriented at an angle ≤ 50° to the axial direction. Instead of rows of profile blocks, circumferential profile ribs may be formed in the tread, which are structured in a block-like manner by grooves or cuts.

[0021] How Fig. Figure 1 shows that each profile block 1 is traversed by two cuts 4, which run straight and parallel to the transverse grooves 3. For example... Fig. As shown in Figure 2, the cuts 4 each have two cut walls 5, 5', a cut base 4a, and a maximum radial depth t1, which is 30% to 100% of the profile depth. The cuts 4 may have a shallower depth in certain sections, for example, at their edges. At the tread periphery, the cuts 4 have a width b1 of 0.30 mm to 1.50 mm, particularly 0.40 mm to 1.20 mm. This width b1, which is particularly constant, is determined as the shortest distance between the two cut edges 4b at the tread periphery and corresponds to the distance between the cut walls 5, 5'.

[0022] In the Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 to Fig. In the embodiments shown in Figure 7, the cut walls 5, 5' are each provided with a structure consisting of a plurality of microgrooves 6 and bridges 7 located between the microgrooves 6 at the level of the cut walls 5, 5 or extending to the level of the cut walls 5, 5, wherein the microgrooves 6 and the bridges 7 in the examples run parallel to the tread periphery and to the cut edges 4b at the tread periphery. For example Fig. Figure 2 shows that the cut walls 5, 5' in sections directly adjacent to the tread periphery and the cut base 4a, and having a width a1 of at least 0.50 mm up to, in particular, 1.00 mm, are free of the structure of microgrooves 6 and bridges 7. The structure of microgrooves 6 and bridges 7 can extend to the radially extending side edges of the cut walls 5, 5'.

[0023] The structures consisting of microgrooves 6 and bridges 7 are identical on the two incision walls 5, 5' and consist of microgrooves 6 of the same dimensions, and in the preferred embodiment (as shown) are symmetrical to the one in the Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 to Fig. The incision center plane M is indicated in 7 and extends radially in the direction of the incision. In alternative embodiments not shown, the structure formed on one incision wall 5 is offset radially relative to the structure formed on the second incision wall 5', for example such that a microgroove 6 on one incision wall 5 is opposite a bridge 7 between two microgrooves 6 on the other incision wall 5'.

[0024] In the Fig. 2, Fig. 3, Fig. 4 to Fig. In the 5 illustrated design variants, the bridges 7 are provided with outer surfaces 7a, which are located at the level of the respective cut wall 5, 5'.

[0025] The microgrooves 6 each have a bottom 6a, the deepest point of which is located opposite the respective groove wall 5, 5' and perpendicular to it at a depth t2 of 0.10 mm to 1.00 mm, in particular 0.20 mm to 0.50 mm, preferably up to 0.30 mm.

[0026] The width b2 of the microgrooves 6, determined at the level of the cut walls 5, 5', is also 0.10 mm to 1.00 mm, in particular 0.20 mm to 0.50 mm, preferably up to 0.30 mm. The microgrooves 6 also have a mutual spacing a2, which, in embodiments with bridges 7 designed as webs between the microgrooves 6, corresponds to the width of the bridges 7 at the level of the cut walls 5, 5' and is 0.05 mm to 1.00 mm, in particular 0.10 mm to 0.50 mm, preferably up to 0.30 mm. In embodiments of microgroove structures with bridges 7 rounded in cross-section ( Fig. 7) the mutual distance a2 corresponds to the distance between the centers of the lowest points of the floors 6a of the microgrooves 6, where this distance corresponds to the width b2 of the microgrooves 6.

[0027] The following section discusses the individual examples of implementation.

[0028] Fig. Figure 2 shows an embodiment of the microgrooves 6 with a U-shaped cross-section having a bottom 6a running parallel to the incision walls 5, 5' and groove flanks 6b running at right angles to the incision walls 5, 5.

[0029] Fig. 3 and Fig. Figures 4 each show an embodiment in which the microgrooves 6 are rounded in cross-section in an arc- or dome-shaped manner, in particular along a circular arc ( Fig. 4), for example, a semicircle.

[0030] In the Fig. 5 and Fig. In the embodiments shown in Figure 6, the microgrooves 6 have a triangular cross-section. Fig. 5 There are two groove flanks 6b extending towards the base 6a, which is designed as a narrow plateau, and which run analogously to the sides of an isosceles triangle. In Fig. 6 The groove flanks 6b taper to a point and have different lengths. As a result, the microgrooves 6 form a sawtooth-shaped structure on the incision walls 5, 5'.

[0031] Fig. Figure 7 shows a variant design with microgrooves 6 and bridges 7, which in cross-section are rounded bulges running obliquely in the same direction.

[0032] A variety of other rounded and / or geometric cross-sectional shapes for the microgrooves 6 and the bridges 7 are possible.

[0033] The number of microgrooves 6 per incision wall 5, 5' is five to one hundred, in particular ten to fifty.

[0034] Fig. Figure 8 shows a schematic view of a cut wall 5 with a multitude of microgrooves 6 and bridges 7 running parallel to each other and parallel to the periphery of the tread, therefore straight, each of which can have one of the cross-sectional shapes shown and described and which run transversely across the cut wall 5.

[0035] Fig. Figure 9 shows an alternative arrangement of microgrooves 6 in strip form, based on a view of a cut wall 5, wherein the strips 8 run radially and are spaced apart from each other and have a constant width of, for example, 3.00 mm to 10.00 mm.

[0036] Fig. Figure 10 shows a variant design in which the microgrooves 6 and the bridges 7 run over the cut wall 5' in the form of arcs parallel to the center M5 of the cut wall 5' symmetrically.

[0037] In other embodiments not shown, the microgrooves 6 run at an acute angle up to a right angle to the incision edges 4b at the tread periphery, whereby any arcuate or wavy course is also possible. In other embodiments, the microgrooves 6 are formed on incision walls that have a zigzag or wave shape or other 3D structure extending transversely across the profile positive in the direction of the incision and / or in a radial direction. Reference symbol list 1 profile block 2 circumferential grooves 3 transverse grooves 4. Cut 4a Cut point 4b Cutting edge 5.5' cut wall 6 microgrooves 6a Floor 6b Groove flank 7 Bridge 7a Outdoor area 8 strips a1 width a2 distance (between microgrooves 6) b1 Width (cut4) b2 width (microgroove 6) M Center line M5 Center t1 Depth (cut 4) t2 depth (microgroove 6) QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 6,116,310 B

[0002] JP H08258515 A

[0003] EP 3 441 241 A1

[0004]

Claims

[1] Vehicle tires with a tread featuring profile positives, such as profile blocks (1) or profile ribs, with cuts (4) having two radially extending cut walls (5, 5') which have a mutually constant distance to each other, corresponding to the cut width (b1), of 0.30 mm to 1.50 mm, in particular 0.40 to 1.00 mm, wherein each cut wall (5, 5') is provided with a structure of parallel microgrooves (6) and bridges (7) located at the level of the cut walls (5, 5') between the microgrooves (6), wherein the microgrooves (6) have a depth (t2) of 0.10 mm to 1.00 mm determined perpendicular to the cut walls (5, 5') and a width (b2) of 0.10 mm to 1.00 mm determined at the level of the cut walls (5, 5'), and wherein the structures of the microgrooves (6) and bridges (7) on the two incision walls (5, 5') are identical and consist of microgrooves (6) of the same dimensions,characterized by , that the microgrooves (6) on one incision wall (5) run parallel to the microgrooves (6) on the opposite incision wall (5'). [2] Vehicle tires according to claim 1, characterized by , that the depth (t2) of the microgrooves (6) is 0.20 mm to 0.50 mm, preferably up to 0.30 mm. [3] Vehicle tires according to claim 1 or 2, characterized by , that the width (b2) of the microgrooves (6) determined at the level of the incision walls (5, 5') is 0.20 mm to 0.50 mm, preferably up to 0.30 mm. [4] Vehicle tires according to any one of claims 1 to 3, characterized by , that the bridges (7) located between the successive microgrooves (6) have a width of 0.05 mm to 1.00 mm, in particular 0.10 mm to 0.50 mm, preferably up to 0.30 mm, at the level of the incision walls (5, 5'). [5] Vehicle tires according to any one of claims 1 to 3, characterized by, that the microgrooves (6) and the bridges (7) are bulges in cross-section and are designed such that they connect directly to each other. [6] Vehicle tires according to any one of claims 1 to 5, characterized by , that the microgrooves (6) on one incision wall (5) are opposite the microgrooves (6) on the other incision wall (5'). [7] Vehicle tires according to any one of claims 1 to 5, characterized by , that the microgrooves (6) on one incision wall (5) are offset in a radial direction relative to the microgrooves (6) on the other incision wall (5'). [8] Vehicle tires according to one of claims 1 to 4, 6 or 7 characterized by , that the microgrooves (6) have a U-shaped cross-section with a bottom (6a) running parallel to the incision walls (5, 5') and two groove flanks (6b) running at right angles to the incision walls (5, 5). [9] Vehicle tires according to one of claims 1 to 4, 6 or 7 characterized by , that the microgrooves (6) are curved or domed in cross-section, in particular along a circular arc, for example a semicircle. [10] Vehicle tires according to one of claims 1 to 4, 6 or 7 characterized by that the microgrooves (6) have a triangular or triangular-like cross-section. [11] Vehicle tires according to any one of claims 1 to 10, characterized by , that the number of microgrooves (6) per incision wall (5, 5') is five to one hundred, in particular ten to fifty. [12] Vehicle tires according to any one of claims 1 to 10, characterized by that the microgrooves (6) run straight. [13] Vehicle tires according to any one of claims 1 to 12, characterized by that the microgrooves run at an angle of up to 90° to the periphery of the tread or in an arc shape overall. [14] Vehicle tires according to any one of claims 1 to 13, characterized by, that the structure consists of microgrooves (6) and bridges (7) of several strips with a particularly constant width of preferably 3.00 mm to 10.00 mm. [15] Vehicle tires according to any one of claims 1 to 14, characterized by , that the cut walls (5, 5') immediately adjacent to the tread periphery and the cut base (4a) are subsequently free of the structure of microgrooves (6) and bridges (7) over a section with a width of at least 0.50 mm and in particular up to 1.00 mm.

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