UTILITY VEHICLE TIRE

The invention relates to a utility vehicle tire having sidewalls (2) and having a tread (1) with shoulder-side profile ribs (3), which shoulder-side profile ribs have shoulder-side profile blocks (6) which are separated from one another by transverse channels (5) and which have in each case one flank surface (6a) running in the direction of the adjoining sidewall (2), wherein, on at least one sidewall (2), there is formed a flank guard (7′) which adjoins the shoulder-side profile blocks (6) and which is elevated in relation to the level of the sidewall (2). It is the intention for the flank guard to be designed such that the risk of crack formation is greatly reduced. This is achieved in that the flank guard (7′) is formed from a multiplicity of wedge-shaped elevations (7), wherein each wedge-shaped elevation (7) adjoins the flank surface (6a) of a shoulder-side profile block (6) and has an outer surface (7a) which, in the tire cross section, transitions without a kink into the flank surface (6a) of the profile block (6).

The invention relates to a utility vehicle tire having sidewalls and having a tread with shoulder-side profile ribs, which shoulder-side profile ribs have shoulder-side profile blocks which are separated from one another by transverse channels and which have in each case one flank surface running in the direction of the adjoining sidewall, wherein, on at least one sidewall, there is formed a flank guard which adjoins the shoulder-side profile blocks and which is elevated in relation to the level of the sidewall.

A flank guard formed on the sidewalls of utility vehicle tires protects the sidewall regions and the “off-shoulder regions” of the tread from damage such as cracks, cuts or increased wear, which can occur for example in the event of contact with curbs or during driving on unpaved roads.

A utility vehicle tire of the type mentioned in the introduction is currently (as of October 2019) known and available under the designation Conti HDC 3. On each sidewall, this tire has a flank rib which runs in encircling fashion around the circumference of the sidewall and which has an edge which runs in encircling fashion in a circumferential direction. The flank rib of relatively massive form offers, above all, good protection against damage.

The invention is based on the object, in the case of a utility vehicle tire of the type mentioned in the introduction, of designing a flank guard such that, with good protection against damage, crack formation can also be reliably prevented.

The stated object is achieved according to the invention in that the flank guard is formed from a multiplicity of wedge-shaped elevations, wherein each wedge-shaped elevation adjoins the flank surface of a shoulder-side profile block and has an outer surface which, in the tire cross section, transitions without a kink into the flank surface of the profile block.

The flank guard provided according to the invention is therefore composed of individual wedge-shaped elevations which, in comparison to the hitherto conventional encircling flank ribs, require less rubber material, are significantly more stable, and have little or no tendency to crack owing to the kink-free transition of their outer surfaces into the shoulder-side flank surfaces of the profile blocks.

An embodiment is particularly advantageous in which each wedge-shaped elevation adjoins the flank surface over its length measured in a circumferential direction.

In a preferred embodiment, as viewed in the tire cross section, each wedge-shaped elevation has a maximum width of 3.0 mm to 7.0 mm, in particular of 4.0 mm to 5.0 mm, measured at the level of the sidewall and in a radial direction. Such a flank guard requires only little rubber material.

In this context, it is furthermore expedient if each wedge-shaped elevation has a thickness measured perpendicular to the level of the sidewall, which thickness, as viewed in the tire cross section, increases over the extent of the outer surface in the direction of the sidewall proceeding from the flank surface of the shoulder-side profile block.

It is furthermore preferable here if each wedge-shaped elevation has a maximum thickness of 1.0 mm to 3.0 mm, in particular of 1.5 mm to 2.5 mm.

The risk of crack formation is additionally reduced if, as viewed in the tire cross section, the outer surface of each wedge-shaped elevation is continuously inwardly curved, in particular in the shape of a circular arc.

A further preferred embodiment that requires little rubber material is characterized in that each wedge-shaped elevation has an isosceles trapezoidal shape as seen in a view directed toward the sidewall, wherein the longer base side of the trapezoid is situated at the connection of the outer surface of the elevation to the flank surface of the shoulder-side profile block.

In this embodiment, it has proven to be particularly advantageous if each wedge-shaped elevation has, at the shorter base side of the trapezoid, a length measured in the circumferential direction which is 40% to 70%, in particular 50% to 60%, of the length of the flank surface of the shoulder-side profile block measured in the circumferential direction.

A flank guard composed of a multiplicity of wedge-shaped elevations is preferably formed on each sidewall.

For the stability of the elevations, it is advantageous if these have delimiting surfaces which run between their outer surface and the respective sidewall and which enclose an angle of 90° to 130°, in particular of at least 100°, with the sidewall.

Utility vehicle tires designed according to the invention are in particular truck tires of radial construction.

FIG.1shows a shoulder-side partial region of a tread1and a circumferential portion of a sidewall2of a utility vehicle tire. At each tire shoulder, the tread1has a shoulder-side profile rib3which runs in encircling fashion in a circumferential direction and which is delimited to the inside of the tread by a circumferential channel4. Situated between the shoulder-side profile ribs3is a profiled, middle tread region which, in a preferred embodiment, has further profile ribs.

Each shoulder-side profile rib3is subdivided into substantially cuboid profile blocks6by transverse channels5of known design, which emerge at the outside of the tread. Outside the ground contact patch, each profile block6has a shoulder-side flank surface6awhich runs, between mutually adjacent transverse channels, in a direction toward the sidewall2. The flank surface6ahas—measured at its margin facing toward the sidewall2—a length lBin a circumferential direction, which length correlates with the spacing between the transverse channels5.

Situated on the sidewall2is a flank guard7′ which runs in encircling fashion in a circumferential direction and which is formed from a multiplicity of successive wedge-shaped elevations7, which are triangular in the tire cross section (FIG.3a). The wedge-shaped elevations7are each assigned to one of the shoulder-side profile blocks6, wherein each wedge-shaped elevation7adjoins the shoulder-side flank surface6aof the respective profile block6over the entire length lB.

Each wedge-shaped elevation7has an outer surface7awhich, in the tire cross section, is continuously slightly inwardly curved, in particular in the shape of a circular arc, and which is uniform with the flank surface6aof the profile block6(FIG.3atoFIG.3c). Accordingly, as viewed in the tire cross section, the outer surface7atransitions into the flank surface6awithout a kink. InFIG.1, at the numbered wedge-shaped elevation7, the connection of the outer surface7ato the corresponding flank surface6ais indicated by dashed lines.

In the exemplary embodiment shown, the wedge-shaped elevation7and its outer surface7ahave an isosceles trapezoidal shape as seen in a view directed toward the sidewall2, wherein the longer base side of the associated trapezoid (=base of the trapezoid) is situated at the connection of the outer surface7ato the flank surface6a(see alsoFIG.2).

The wedge-shaped elevation7furthermore has two triangular side surfaces7b, which each adjoin one of the trapezoid legs of the trapezoid of the outer surface7aof said elevation and run to the sidewall2, and a substantially rectangular delimiting surface7c, which adjoins the short base side of the trapezoid of the outer surface7aof said elevation and runs between the side surfaces7b(see alsoFIG.2). The triangular side surfaces7band the rectangular delimiting surface7ceach enclose an angle α (shown inFIG.3afor the delimiting surface7c) of 90° to 130°, in particular of at least 100°, with the sidewall2. The transition of the side surfaces7bto the delimiting surface7cand the transition of the outer surface7ato the side surfaces7band to the delimiting surface7cis preferably rounded. In accordance with the wedge shape of the elevation7, the side surfaces7bend at the mutual connection of the outer surface7aand the flank surface6a.

Owing to its wedge shape, the elevation7has a thickness measured perpendicularly to the level of the sidewall2, which thickness increases continuously in the direction of the rectangular delimiting surface7cproceeding from the mutual connection of the outer surface7aand the flank surface6a. At the transition region of the outer surface7ato the rectangular delimiting surface7c, the elevation7has a maximum thickness smax, measured in relation to the locally adjacent level of the sidewall2(FIG.3a), of 1.0 mm to 3.0 mm, in particular of 1.5 mm to 2.5 mm. Furthermore, as viewed in the tire cross section, the elevation7has a maximum width bmax, which correlates with the height of its trapezoid and is measured at the level of the sidewall2(FIG.3a), of 3.0 mm to 7.0 mm, in particular of 4.0 mm to 5.0 mm, and a length l (FIG.2), measured in a circumferential direction without taking into account any rounded portions on the delimiting surface7c, of 40% to 70%, in particular of 50% to 60%, of the abovementioned length lBof the flank surface6a.

The wedge-shaped elevations7are composed at least for the most part, in particular entirely, of the rubber material of the sidewall2.

The invention is not limited to the exemplary embodiment described.

In particular, the elevations7may have a shape that deviates from the isosceles trapezoidal shape. The elevations7may in particular have an asymmetrical trapezoidal shape, or the shape of a rectangle, as seen in a view directed toward the sidewall2. A flank guard formed from elevations7is preferably situated on each sidewall.

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