VEHICLE AIR TIRES

Description

[0001] The invention relates to a vehicle pneumatic tire with sidewalls having at least one circumferential section designed as a circular ring section with a radial width of 20.00 mm to 120.00 mm and with a base level, wherein a plurality of elevations with a height of up to 1.00 mm relative to the base level of the circumferential section are formed on the circumferential section, wherein the elevations are circular in plan view, conical in the direction of their height and regularly distributed.

[0002] Such a vehicle pneumatic tire is known, for example, from US Patent 2020 / 0262252 A1. This vehicle pneumatic tire has sidewalls with at least one circumferential section shaped as a circular ring segment, comprising a base level and a multitude of regularly distributed projections. The projections are circular in plan view, have a diameter of 0.30 mm to 1.00 mm at the base level, and a height of 0.20 mm to 0.60 mm relative to the base level, and are conically shaped in the direction of their height. The projections are, for example, formed in the form of obliquely truncated cones and have a recess extending along the conical axis, which, while maintaining high rigidity of the projection, ensures light absorption from various directions.

[0003] DE 10 2021 206 642 A1 discloses a vehicle tire with sidewalls on which, in one or more circumferential sections, at least two rows of parallelogram-shaped projections (as seen from above) are formed, extending concentrically to the annular shape of the sidewall. These projections have a height of 0.80 mm to 1.50 mm above the base level. Narrow gaps are present both between the projections within a row and between adjacent rows. The rows of projections are offset from one another in the circumferential direction of the sidewall, overlapping each other. The spaces between the projections are also offset from one another in the circumferential direction, from row to row, and are not aligned with each other. The design and arrangement of the projections is aerodynamically unfavorable, giving the sidewall high robustness, but this comes at the expense of flexibility, especially near the tread area.Especially in this area, the amount of rubber material in the raised areas impairs the necessary cushioning and deformation of the tire when it rolls on the ground, which has an adverse effect on the rolling resistance of the tire.

[0004] The invention is therefore based on the objective of designing the sidewalls of a vehicle pneumatic tire of the type mentioned at the outset with elevations in such a way that, while maintaining good robustness, a flexibility advantageous for low rolling resistance is ensured near the tread area and the aerodynamic airflow over the sidewalls during driving is improved.

[0005] The problem stated in the invention is solved by the fact that the elevations at the base level have a diameter of 2.00 mm to 6.50 mm, wherein, in the case of a central division of the circumferential section into a radially outer and a radially inner subsection, the elevations in the radially outer subsection cover a total of 7% to 20% of the area of ​​this subsection and in the radially inner subsection cover a total of 25% to 40% of the area of ​​this subsection.

[0006] The circular and conical shape of the ridges provided according to the invention is particularly advantageous aerodynamically, as such ridges offer only minimal resistance to the airflow. In the radially outer section, the ridges cover a smaller proportion of the total surface area than in the radially inner section, so that correspondingly less rubber volume is present in the radially outer section than in the radially inner section. This allows the tread to deform accordingly as the tire rolls on the road surface, effectively contributing to low rolling resistance. Nevertheless, a good compromise is achieved with regard to the stability and protective effect of the ridges on the sidewall, especially those in the radially inner section.

[0007] According to a preferred embodiment, the protrusions are frustoconical in shape and have a circumferential surface that runs at an angle of 10° to 45°, particularly 15° to 25°, relative to a perpendicular to the base level. Frustoconical protrusions are exceptionally robust and not very susceptible to damage, for example, when the tire comes into contact with curbs or the like.

[0008] In this regard, and with regard to the visibility of the protrusions on the side wall, it is further advantageous if the protrusions have a height of at least 0.40 mm and preferably of 0.50 mm to 0.70 mm.

[0009] All raised sections preferably have the same height, regardless of whether they have a smaller or larger diameter. In the radially outer section, there tend to be significantly smaller raised sections or fewer raised sections with a slightly larger diameter than in the radially inner section. Furthermore, to support the desired suspension behavior in the tread area of ​​the tire, it is advantageous if the total rubber volume occupied by the raised sections in the radially outer section is 20% to 80%, and particularly 40% to 60%, less than that of the raised sections in the radially inner section.

[0010] Furthermore, it is aerodynamically advantageous to arrange all the protrusions provided in the circumferential section as uniformly as possible, so that the circumferential section contains protrusions with the selected smallest diameter - these primarily in the radially outer section - and protrusions with the selected largest diameter - these preferably or primarily in the radially inner section - as well as protrusions whose diameter lies between the smallest and the largest diameter.

[0011] For a uniform arrangement of the protrusions, it is further advantageous if the protrusions are arranged in a plurality of radially extending rows and run within the rows at intervals of 0.50 mm to 8.00 mm between their centers of circles, preferably the intervals within the rows, in all rows and between the rows are the same size and the space between the protrusions within a row has a width of at least 1.20 mm.

[0012] In this context, it is also advantageous if the elevations in the successive rows in the circumferential direction of the circumferential section are offset from each other in the radial direction, in particular such that one elevation from one row is located centrally opposite two radially successive elevations in the other, adjacent row.

[0013] In a further aerodynamically advantageous, uniform arrangement of the protrusions, at least in a partial area of ​​the circumferential section, the mutual arrangement of the protrusions in the circumferentially successive rows of protrusions is such that connecting lines between the centers of the circles form a network of equilateral triangles whose side lengths are 5.00 mm to 8.50 mm.

[0014] A particularly visible and visually appealing arrangement of the protrusions when viewed from the side wall is achieved if, in at least some of the circumferentially successive rows of protrusions, the design and arrangement of the protrusions are coordinated in such a way that, viewed in the circumferential direction of the circumferential section, an arrow-shaped arrangement of the protrusions with two arrowheads is created across the width of the circumferential section, whereby this arrow-shaped arrangement is particularly striking if, in each arrowhead, there are predominantly, in particular at least 70%, protrusions of the same size.This arrow-shaped arrangement of the ridges is also suitable for tires that are to be mounted with a specific rolling direction when driving forward, in order to indicate the specified rolling direction, while at the same time supporting a particularly advantageous aerodynamic flow to the sidewall when driving forward and at higher speeds.

[0015] The pattern formed by the elevations in the circumferential section can be particularly emphasized on the side wall by the fact that the circumferential section outside the elevations is at least partially covered by a background hatching originating from the base level, which consists of micro-elevations running parallel or substantially parallel to each other with a triangular or trapezoidal cross-section, wherein the micro-elevations have a height of 0.25 mm to 0.35 mm, in particular 0.30 mm, and vertex areas whose mutual distance, determined between the centers of adjacent vertices, is 0.30 mm to 0.50 mm.

[0016] Further features, advantages, and details of the invention will now be described in more detail with reference to the drawing, which schematically depicts an exemplary embodiment. The drawing shows Fig. 1 a cross-section of one half of a vehicle tire, Fig. 2 a view of a circumferential section of a side wall with an embodiment of the invention, Fig. 3 detail D from Fig. 2 in enlarged view, Fig. 4 a sectional view along line IV-IV of the Fig. 3 and Fig. 5 a sectional view along line VV of the Fig. 3 .

[0017] Vehicle pneumatic tires designed according to the invention are tires for motor vehicles, in particular for multi-track motor vehicles, preferably radial tires for passenger cars, vans, SUVs or light trucks (light trucks with a gross vehicle weight of ≤ 7.5 t).

[0018] Fig. 1 Figure 1 shows an exemplary and schematic cross-section of one half of a vehicle pneumatic tire with its essential components. These components include, in particular, a profiled tread 1, of which two circumferential grooves 2 are shown as examples, furthermore bead areas 3 with bead cores 4 and core profiles 5, a multi-layer belt 6, and a carcass ply 7, which extends from bead area 3 to bead area 3 and surrounds the bead cores 4 from the inside of the tire to the outside. The vehicle pneumatic tire also has sidewalls 8 made of a rubber material, which run between the bead areas 3 and the tread 1 and are designed to be relatively thin in order to keep the weight of the vehicle pneumatic tire and thus the rolling resistance low. To make the sidewalls 8 more robust against external influences, such as when driving over curbs, they are, as shown in Figure 1, thicker. Figuren 2 bis 5 will be explained in more detail, with a variety of in Fig. 1 Surveys 9 are provided with regard to their dimensions, which are exaggerated and schematically presented.

[0019] Fig. 2 Figure 1 shows a view of a circumferential section 10, depicted as an annular segment, on a sidewall 8 of a vehicle tire. The circumferential section 10 covers an annular segment on the sidewall 8 with a width b1 of 20.00 mm to 120.00 mm, in particular 30.00 mm to 80.00 mm. Such a circumferential section 10 can be repeated on the sidewall 8 in different dimensions, or it can extend essentially continuously over a larger part of the circumference of the sidewall 8, for example, over three-quarters of the circumference. The circumferential section 10 or sections 10 can be marked with designations, for example, a dimension designation of the tire in question and / or various symbols, which locally overlay or interrupt the design with raised sections 9.The depicted circumferential section 10 terminates on one side at a further, differently designed circumferential section 11, which contains, for example, the tire manufacturer or other tire identification. Since circumferential section 11 is not part of the invention, its design will not be discussed further.

[0020] The surveys 9 interrupt, in the depicted execution, a section 10 that otherwise covers a scope and is based on a base level 14 ( Fig. 4, Fig. 5 ) background hatching 12 extending from the perimeter section 10, of which an exemplary partial cross-section in Fig. 4 The background hatching 12 consists of, according to Fig. 3 from micro-elevations running parallel to each other or essentially parallel to each other 13, which - like Fig. 4 The micro-protrusions 13 show a triangular or trapezoidal cross-section with side flanks 13a extending at an angle α of 20° to 50°, particularly 30°, to a perpendicular to the base level 14, having a height h1 of 0.25 mm to 0.35 mm, particularly 0.30 mm, determined perpendicular to the base level 14, preferably the same for all micro-protrusions 13, and whose mutual distance a between the centers of the vertices of adjacent micro-protrusions 13 is 0.30 mm to 0.60 mm, depending on the inclination of the side flanks 13a. The micro-protrusions 13 can be straight or, as shown, slightly wavy ( Fig. 3 In an alternative version, not shown, there is no background hatching 12 of micro-elevations 13, but rather a largely smooth base surface is present at the base level 14.

[0021] All elevations 9 are circular in plan view ( Fig. 3 ) and in cross-section, as in Fig. 5 As shown by way of example, the projections are conical and in particular frustoconical in shape, with a surface 9a surrounding the projections 9, which runs at an angle β of 10° to 45°, in particular 15° to 25°, and preferably 20°, relative to a perpendicular to the base level 14. All projections 9 have a height h2 determined perpendicular to the base level 14, which is 0.40 mm to 1.00 mm, in particular 0.50 mm to 0.70 mm, and the height h1 ( Fig. 4 ) the micro-raised areas 13 in the base hatching 14 exceeds by at least 0.10 mm. In a preferred embodiment, all raised areas 9 have identical heights h 2, preferably of 0.60 mm. At the base level 14, the diameter d of the raised areas 9 is 2.00 mm to 6.50 mm. How Fig. 2 and Fig. 3 as shown, there are elevations 9 with the selected smallest diameter d as well as elevations 9 with the selected largest diameter d from this area, and further elevations 9 whose diameter d lies between the smallest and the largest diameter d.

[0022] If the circumferential section 10 is divided exactly in the middle into two subsections 15a, 15b designed as circular ring sections ( Fig. 2 ) - divided into a radially outer subsection 15a and a radially inner subsection 15b, as shown in Fig. 2 as indicated by line l 1, the design and / or arrangement of the surveys 9 is such that the surveys 9, at the base level 14 ( Fig. 5 ) determined and, with a regular or largely regular distribution over the respective area of ​​subsection 15a, 15b, the radially outer subsection 15a covers a smaller area overall – when considering all elevations 9 in total – than the radially inner subsection 15b. The extent of the respective coverage is such that in the radially outer subsection 15a the elevations 9 occupy a total of 7% to 20%, in particular 12% to 18%, of the total area of ​​subsection 15a, and in the radially inner subsection 15b 25% to 40%, in particular 27% to 35%, of the total area of ​​the inner subsection 15b. In the radially outer subsection 15a, the total rubber volume occupied by the elevations 9 is in particular 20% to 80%, in particular 40% to 60%, less than that of the elevations 9 in the radially inner subsection 15b.

[0023] Near the tread 1, the design ensures that the compression occurring when the tire rolls on the road surface can take place unhindered or almost unaffected, thus promoting lower rolling resistance. This means that the influence of the protrusions 9 in the radially outer section 15a on the rolling resistance is small or almost negligible.

[0024] Preferred further arrangements of the surveys 9 in scope section 11 are now based on the Figuren 2 and 3 explained in more detail. The elevations 9 are arranged in a multitude of radially extending rows, wherein in Fig. 2 Two adjacent rows are marked with dashed lines r1 and r2. In all rows, the elevations are equidistant from each other at the ( Fig. 3 The raised sections 9 extend from the centers M of the circles and measure between 5.0 mm and 8.50 mm. The space between the raised sections 9 within a row, measured at the base of the raised sections 9, has a width b 2 of at least 1.50 mm. Furthermore, in the rows that are successive in the circumferential direction of the circumferential section 10, the raised sections 9 are radially offset from one another, such that one raised section 9 from one row is centered opposite two radially successive raised sections 9 in the other, adjacent row. Thus, there is a radial offset of the raised sections r 1 , r 2 in the circumferential direction.

[0025] Fig. 3 shows a preferred embodiment of the mutual arrangement of the rows of elevations 9. By connecting the centers M of all elevations 9, a network of equilateral triangles is formed, as shown in Fig. 3 as indicated by dashed lines l 2. The side lengths of these triangles are therefore equal and correspond to the aforementioned distance at , which is 5.00 mm to 8.50 mm.

[0026] Fig. 2 Figure 1 shows another preferred embodiment of the arrangement of the protrusions 9 in the circumferential section 10. The sizes or diameters d ( Fig. 5 The elevations 9 in at least some of the circumferentially successive rows of elevations 9 are selected and coordinated such that, viewed in the circumferential direction of the circumferential section 10, an arrow-shaped arrangement of elevations 9 is created over the width b 1 of the circumferential section. Two lines pf symbolize in Fig. 2The two arrowheads of this arrow-shaped arrangement or design. This appearance is achieved in particular by the fact that each arrowhead (line pf) has largely equal-sized elevations 9. This design is also suitable for tires that are to be mounted with a specific rolling direction when driving forward, in order to indicate the predetermined rolling direction and to support a particularly advantageous aerodynamic airflow over the sidewall when driving forward and at higher speeds. Reference symbol list

[0027] 1. Tread 2. Circumferential groove 3. Bead area 4. Bead core 5. Core profile 6. Belt 7. Carcass ply 8. Sidewall 9. Elevation 9a. Surface 10, 11. Circumferential section 12. Background hatching 13. Micro-elevation 13a. Side surface 14. Base level 15a. Radial outer section 15b. Radial inner section a, am Distance α, β Angle b1, b2 Width d Diameter D Detail h1, h2 Height M Circle center pr Line (arrow leg) l1, l2 Line r1, r2 Line

Claims

1. Pneumatic vehicle tyre comprising sidewalls (8) with at least one circumferential portion (10) designed as a circular ring portion and having a width (b1) in the radial direction of 20.00 mm to 120.00 mm and having a base level (14), a multiplicity of elevations (9) being formed on the circumferential portion (10) with a height (h2), determined with respect to the base level (14) of the circumferential portion (10), of up to 1.00 mm, the elevations (9) being designed as circular when viewed from above and running conically in the direction of their height (h2) and being arranged in a regularly distributed manner, characterized in that the elevations (9) have at the base level (14) a diameter (d) of 2.00 mm to 6.50 mm, with the circumferential portion (10) divided in the middle into a radially outer subportion (15a) and a radially inner subportion (15b), the elevations (9) in the radially outer subportion (15a) cover altogether 7% to 20% of the surface area of this subportion (15a) and the elevations in the radially inner subportion (15b) cover altogether 25% to 40% of the surface area of this subportion (15b).

2. Pneumatic vehicle tyre according to Claim 1, characterized in that the elevations (9) in the radially outer subportion (15a) cover altogether 12% to 18% of the surface area of this subportion (15a) and the elevations in the radially inner subportion (15b) cover altogether 27% to 35% of the surface area of this subportion (15b).

3. Pneumatic vehicle tyre according to Claim 1 or 2, characterized in that the elevations (9) are in the form of a truncated cone and have a circumferential surface area (9a) which runs relative to a perpendicular to the base level (14) at an angle (β) of 10° to 45°, in particular of 15° to 25°.

4. Pneumatic vehicle tyre according to any one of Claims 1 to 3, characterized in that the height (h2) of the elevations (9) is at least 0.40 mm and preferably 0.50 mm to 0.70 mm.

5. Pneumatic vehicle tyre according to any one of Claims 1 to 4, characterized in that, in the radially outer subportion (15a), the rubber volume occupied in total by the elevations (9) is 20% to 80%, in particular 40% to 60%, smaller than that of the elevations (9) in the radially inner subportion (15b).

6. Pneumatic vehicle tyre according to any one of Claims 1 to 5, characterized in that, in the circumferential portion (10), there are elevations (9) with the respectively selected smallest diameter (d) and elevations (9) with the respectively selected largest diameter (d) and elevations (9), the diameter (d) of which is between the smallest and the largest diameter (d).

7. Pneumatic vehicle tyre according to any one of Claims 1 to 6, characterized in that the elevations (9) are arranged in a multiplicity of rows (r1, r2) running in the radial direction and run within the rows (r1, r2) at distances (am) determined between their circle centre points (M) of 5.0 mm to 8.50 mm, the distances (am) within the rows (r1, r2), in all rows (r1, r2) and between the rows (r1, r2) preferably being equal in size and the intermediate space between the elevations (9) located within a row (r1, r2) having a width (b2) of at least 1.20 mm.

8. Pneumatic vehicle tyre according to Claim 7, characterized in that, in the rows (r1, r2) following one another in the circumferential direction of the circumferential portion (10), the elevations (9) are each offset in the radial direction to one another, in particular in such a way that in each case one elevation (9) from the one row (r1, r2) is located in the middle in relation to two elevations (9) following one another in the radial direction in the other, adjacent row (r1, r2).

9. Pneumatic vehicle tyre according to Claim 7 or 8, characterized in that, at least in a subregion of the circumferential portion (10), the mutual arrangement of the elevations (9) in the rows (r1, r2) of elevations (9) following one another in the circumferential direction is such that connecting lines (l2) between the circle centre points (M) form a network of equilateral triangles, the side lengths of which are 5.00 mm to 8.50 mm.

10. Pneumatic vehicle tyre according to any one of Claims 7 to 9, characterized in that, in at least some of the rows of elevations (9) following one another in the circumferential direction, the design and arrangement of said elevations is matched to one another in such a way, that, when viewed in the circumferential direction of the circumferential portion (10), an arrow-shaped arrangement of elevations (9) present over the width (b1) of the circumferential portion (10) and having two arrow legs (pf) arises.

11. Pneumatic vehicle tyre according to Claim 10, characterized in that elevations (9) of equal size are present in each arrow leg (pf), in each case predominantly, in particular to at least 70%.

12. Pneumatic vehicle tyre according to any one of Claims 1 to 11, characterized in that the circumferential portion (10) outside the elevations (9) is at least partially covered by a background hatching (12) which starts from the base level (14) and consists of micro-elevations (13) which run parallel to one another or substantially parallel to one another and have a triangular or trapezoidal cross section, wherein the micro-elevations (13) have a height (h1) of 0.25 mm to 0.35 mm, in particular of 0.30 mm, and vertex regions, the mutual distance (a) of which, determined between the centres of adjacent vertices, is 0.30 mm to 0.50 mm.