VEHICLE AIR TIRES

Description

[0001] The invention relates to a pneumatic vehicle tire having at least one surface element formed on its outer surface with a contrast structure imparting a roughness to the surface element.

[0002] It is known to form surface elements with a contrasting structure on the outer surface of pneumatic vehicle tires, particularly on sidewalls. These elements primarily serve the purpose of creating a contrast with other, particularly unstructured, surface areas of the sidewalls, for example, to improve the recognizability of characters on the sidewalls, such as design elements or logos. Surface elements with contrasting structures make this possible by reflecting less light than smooth surfaces, thus "capturing" incident light and therefore appearing darker to the observer than smooth surface areas.

[0003] Pneumatic vehicle tires having a contrast structure are known from DE 20 2014 010855 U1, EP 2554401 A1, WO 2016 / 005569 A1, US 2015 / 004335 A1, and DE 10 2013223567 A1.

[0004] A pneumatic vehicle tire of the type mentioned above is known, for example, from US 2012 / 0227879 A1. On the outer surface of the pneumatic vehicle tire, at least one surface element is formed with a contrasting structure consisting of a plurality of, for example, conical elevations. The conical elevations have an average diameter of 0.03 mm to 0.5 mm, with at least five, preferably at least fifteen, elevations per square millimeter. The average roughness depth RZ of the contrasting structure, determined according to the now-revoked DIN 4768, is 5 µm to 30 µm. To form such elevations on the tire, the corresponding molded part of the vulcanization mold that vulcanizes the tire is provided with depressions by laser engraving.

[0005] US 2016 / 0152095 A1, US 2016 / 0185163 A1, and US 2016 / 0137008 A1 each deal with a pneumatic vehicle tire having a surface element with a contrasting structure on at least one of its sidewalls. The contrasting structure is formed, for example, by conical elevations located in a depression formed in the sidewall and having an average cross-sectional area of ​​0.0007 mm² to 0.06 mm².

[0006] The contrast structures known so far are largely regular in design, which limits their contrast effect.

[0007] The invention is based on the object of providing a contrast structure on tires with a significantly improved contrast effect.

[0008] The stated object is achieved according to the invention in that the contrast structure is a surface-covering, uneven peak and valley contrast structure with an area-related roughness value S a according to EN ISO 25178 of 50 µm to 150 µm and in that the uneven peak and valley contrast structure with each height surface which extends parallel to the base level of the peak and valley contrast structure, lies at a height of 100 µm relative to the base level and has a surface area of ​​1 mm x 1 mm, forms a cutting surface which takes up 40% to 60% of the surface area of ​​the height surface.

[0009] Such a peak and valley contrast structure is characterized—in contrast to the familiar contrast structures formed by individual, largely identically shaped elevations—by "connected" or merging peaks and valleys that reach different heights (mountains) and are located at different levels (valleys), as well as ridges and saddles. The peak and valley contrast structure is particularly characterized by a multitude of intersections where several peak structures or several valley structures converge. This makes the "negative" of the contrast structure very stable in the vulcanization mold, allows for easy venting during molding of the green tire, and allows it to be molded into the tire in perfect condition.Due to its irregularity and significantly greater roughness compared to conventional contrast structures, the peak and valley contrast structure according to the invention optimally captures light, resulting in a significantly better contrast effect compared to smooth surface areas. Furthermore, the irregular peak and valley contrast structure is also particularly robust against any contaminants remaining in the corresponding molded part of the vulcanization mold or any minor damage that may occur there.

[0010] According to a preferred embodiment, the surface-related roughness value S a according to EN ISO 25178 of the irregular peak and valley contrast structure is 70 µm to 120 µm. Such a rough peak and valley contrast structure is particularly robust and, at the same time, enables a very good contrast effect with smooth surface areas.

[0011] Further preferred embodiments, which deal with the height profile of the mountain and valley contrast structure, contribute to a further improvement of the contrast effect.

[0012] In this context, it is advantageous if the uneven peak and valley contrast structure forms a cutting surface with each elevation surface that extends parallel to the base level of the peak and valley contrast structure, is located at a height of 50 µm relative to it and has a surface area of ​​1 mm x 1 mm, which occupies 80% to 90% of the surface area of ​​the elevation surface.

[0013] Furthermore, it is advantageous in this context that the uneven peak and valley contrast structure forms a cutting surface with each elevation surface which extends parallel to the base level of the peak and valley contrast structure, is located at a height of 100 µm relative to the base level and has a surface area of ​​1 mm x 1 mm, which occupies 40% to 60% of the surface area of ​​the elevation surface.

[0014] Furthermore, it is advantageous in this context if the uneven peak and valley contrast structure forms a cutting surface with each elevation surface that extends parallel to the base level of the peak and valley contrast structure, is located at a height of 200 µm relative to the base level and has a surface area of ​​1 mm x 1 mm, which occupies 20% to 40% of the surface area of ​​the elevation surface.

[0015] Furthermore, it is particularly advantageous if the uneven peak and valley contrast structure has peak regions which border on elevation surfaces which extend parallel to the base level of the peak and valley contrast structure, are located at a height of 400 µm relative to the base level and have a surface area of ​​1 mm x 1 mm, wherein the uneven peak and valley contrast structure has up to five, in particular up to three, peak regions within each of these elevation surfaces.

[0016] According to a further preferred embodiment, the peak and valley contrast structure has a height of 400 µm to 500 µm at its highest point(s) relative to the base level. This allows the peak and valley contrast structure to capture a particularly large amount of light, further improving its contrast effect with smooth surface areas.

[0017] In a preferred embodiment, the surface element with the uneven mountain and valley contrast structure is formed on a sidewall of the pneumatic vehicle tire.

[0018] According to a further preferred variant, the surface element with the irregular peak and valley contrast structure is formed on the tread of the pneumatic vehicle tire, preferably also on the outer surface in contact with the ground. To achieve special light / dark effects, the irregular peak and valley contrast structure can be formed on the groove flanks and / or groove bottoms of grooves running in the tread. It is also possible to form surface elements with the irregular peak and valley contrast structure on the shoulder flanks of the tire extending to the sidewalls.

[0019] Preferably, the surface element with the uneven mountain and valley contrast structure forms a design element, a lettering or a character or surrounds such a design element.

[0020] Further features, advantages and details of the invention will now be described in more detail with reference to the drawing, which schematically shows an embodiment of the invention. Fig. 1 a circumferential section of a sidewall of a pneumatic vehicle tire in plan view with an embodiment variant of the invention and Fig. 2 a microscope image of a surface element located on the side wall.

[0021] In all representations shown in the figures, the curvature of the side wall is not taken into account.

[0022] The invention relates to surface elements with a special contrast structure formed on the outer surface of pneumatic vehicle tires.

[0023] The surface elements are formed, for example, on an area of ​​the outer surface which does not come into contact with the ground or does not come into surface contact with the ground when the pneumatic vehicle tire is in use. The surface elements are particularly preferably formed on a sidewall of the pneumatic vehicle tire. Sidewalls of pneumatic vehicle tires usually contain symbols which reproduce the prescribed information, such as dimensions, the speed index, the manufacturer, the intended use (summer / winter tire), or other symbols such as logos or design elements. Surface elements with a contrasting structure can surround the aforementioned symbols on the sidewall or form the symbols themselves. For example, such a surface element is a logo executed in the contrasting structure; alternatively, the surface of the logo itself is smooth and the logo is surrounded by a contrasting structure.

[0024] The surface elements can also be attached in particular to groove flanks and / or groove bottoms of grooves running in the tread or at the tread outlet, i.e. on the shoulder flanks running outside the ground contact area to the side walls, or on the outer surface of the tread, i.e. on the tread that comes into contact with the ground.

[0025] The level opposite which the contrast structure is formed on the finished tire is hereinafter referred to as the base level NB. The base level NB can be formed, for example, by a part of the outer surface of the pneumatic vehicle tire, in particular the sidewall or a bottom of a shallow depression formed on the sidewall.

[0026] The contrasting pattern can be formed on the outer surface of the pneumatic vehicle tire during the vulcanization process. The mold segment(s) of the vulcanization mold, for example, the sidewall shells, are provided with corresponding shallow depressions created by laser engraving. Such a contrasting pattern is therefore a positive compared to the respective base layer. Alternatively, the contrasting pattern can also be laser-engraved on the already vulcanized tire, creating a negative compared to the respective base layer.

[0027] Fig. 1 shows a schematic representation, projected into the plane, of a peripheral section of a side wall 1 with a surface element 2, which essentially has the shape of a section of a circular ring. In Fig. 1 Additionally, a tread runout 3 and an outer bead area 4, which is at least partially covered by the rim when the tire is mounted on a rim, are indicated. Surface element 2 surrounds lettering 5, whose letters ABC have a smooth surface. Lettering 5 is therefore not part of surface element 2.

[0028] Fig. 2 shows a microscope image of a peripheral portion of the surface element 2, with the base level NB additionally indicated, which in the illustrated embodiment corresponds to the level of the side wall 1. As the dimensions show, the microscope image covers an area of ​​approximately 2500 µm x 2500 µm of the surface element 2. The surface element 2 is surface-covering (see Fig. 1 ), i.e. over its entire extent, with an uneven peak and valley contrast structure 6, which imparts roughness, i.e., unevenness, to the surface element 2. The peak and valley contrast structure 6 has a surface-related roughness value S a according to EN ISO 25178 of 50 µm to 150 µm, in particular of 70 µm to 120 µm. The surface-related roughness value S a is, as is known, a surface-related arithmetic mean, in this case an arithmetic mean related to the surface of the peak and valley contrast structure 6.

[0029] The mountain and valley contrast structure 6 is formed by a multitude of mountain structures located at different levels, including ridges and saddles, as well as valley structures. The mountain and valley contrast structure 6 is therefore composed of a multitude of mountains with different heights and a multitude of valleys at different levels.

[0030] The shape of the peak and valley contrast structure 6 is examined below in terms of height surfaces F 1 , F 2 , F 3 and F 4 and explained in more detail using these. The height surfaces F 1 , F 2 , F 3 and F 4 extend parallel to the respective base level NB , have a surface area of ​​1 mm x 1 mm and intersect the peak and valley contrast structure 6 at different heights h 1 (height surface F 1 ), h 2 (height surface F 2 ), h 3 (height surface F 3 ) and h 4 (height surface F 4 ) determined relative to the base level NB. The height surfaces F 1 , F 2 , F 3 and F 4 extend exclusively in the area of ​​the peak and valley contrast structure 6 and therefore do not protrude laterally beyond it. Each elevation surface F 1 , F 2 , F 3 and F 4 therefore has one or more surface areas in which the elevation surface F 1 , F 2 , F 3 and F 4 is penetrated by the mountain and valley contrast structure 6. This or these surface areas form or form a one-piece ormulti-part cutting surface, which is part of the respective height surface F 1 , F 2 , F 3 and F 4. In . Fig. 2 The heights h 1 , h 2 , h 3 , h 4 and, as an example, a height surface F 2 are shown. The height surfaces F 1 , F 3 , and F 4 have been omitted for clarity. The height h 1 is 50 µm, the height h 2 is 100 µm, the height h 3 is 200 µm, and the height h 4 is 400 µm.

[0031] The intersection of the peak and valley contrast structure 6 with each elevation surface F 1 preferably occupies 80% to 90% of the area of ​​the respective elevation surface F 1 . The intersection of the peak and valley contrast structure 6 with each elevation surface F 2 occupies 40% to 60% of the area of ​​the respective elevation surface F 2 . The intersection of the peak and valley contrast structure 6 with each elevation surface F 3 occupies 20% to 40% of the area of ​​the respective elevation surface F 3 . The elevation surfaces F 4 separate peak regions 6a from the remaining peak and valley contrast structure 6. A peak region 6a is a contiguous region of the peak and valley contrast structure 6 that "sits" on or borders on an elevation surface F 4 . Within each elevation surface F 4 , there are preferably up to five, in particular up to three, peak regions 6a.

[0032] Furthermore, the peak and valley contrast structure 6 preferably has a height h max of 400 µm to 500 µm at its highest point(s) relative to the base level NB.

[0033] The invention is not limited to the described embodiment. List of reference numbers

[0034] 1Sidewall 2Surface element 3Tread run-out 4Bead area 5Lettering 6Mountain and valley contrast structure 6aMountain peak area F 1 , F 2 , F 3 , F 4 Height area h 1 , h 2 , h 3 , h 4 , h max Height NB Base level

Claims

1. Pneumatic tyre for a vehicle, having formed on its outer surface at least one surface element (2) with a contrast structure (6) which imparts a roughness to the surface element (3), characterized in that the contrast structure (6) is a large-area, nonuniform hill-and-dale contrast structure (6) having an areal roughness value Sa according to EN ISO 25178 of 50 µm to 150 µm, and in that, with each height surface (F2) which extends parallel to the base level (NB) of the hill-and-dale contrast structure (6), lies at a height (h2) of 100 µm relative to the base level (NB), and has an area of 1 mm x 1 mm, the nonuniform hill-and-dale contrast structure (6) forms an intersection area which occupies 40% to 60% of the area of the height surface (F2).

2. Pneumatic tyre for a vehicle according to Claim 1, characterized in that the areal roughness value Sa according to EN ISO 25178 of the nonuniform hill-and-dale contrast structure (6) is 70 µm to 120 µm.

3. Pneumatic tyre for a vehicle according to Claim 1 or 2, characterized in that, with each height surface (F1) which extends parallel to the base level (NB) of the hill-and-dale contrast structure (6), lies at a height (h1) of 50 µm relative to said base level, and has an area of 1 mm x 1 mm, the nonuniform hill-and-dale contrast structure (6) forms an intersection area which occupies 80% to 90% of the area of the height surface (F1).

4. Pneumatic tyre for a vehicle according to any of Claims 1 to 3, characterized in that, with each height surface (F3) which extends parallel to the base level (NB) of the hill-and-dale contrast structure (6), lies at a height (h3) of 200 µm relative to the base level (NB), and has an area of 1 mm x 1 mm, the nonuniform hill-and-dale contrast structure (6) forms an intersection area which occupies 20% to 40% of the area of the height surface (F3).

5. Pneumatic tyre for a vehicle according to any of Claims 1 to 4, characterized in that the nonuniform hill-and-dale contrast structure (6) has peak regions (6a) which adjoin height surfaces (F4) which extend parallel to the base level (NB) of the hill-and-dale contrast structure (6), lie at a height (h4) of 400 µm relative to the base level (NB), and have an area of 1 mm x 1 mm, wherein the nonuniform hill-and-dale contrast structure (6) has up to five, in particular up to three, peak regions (6a) within each of these height surfaces (F4).

6. Pneumatic tyre for a vehicle according to any of Claims 1 to 5, characterized in that the hill-and-dale contrast structure (6) has a height (hmax) of 400 µm to 500 µm relative to the base level (NB) at its highest point(s).

7. Pneumatic tyre for a vehicle according to any of Claims 1 to 6, characterized in that the surface element (2) having the nonuniform hill-and-dale contrast structure (6) is formed on a sidewall (1) of the pneumatic tyre for a vehicle.

8. Pneumatic tyre for a vehicle having a profiled tread, according to any of Claims 1 to 6, characterized in that the surface element (2) having the nonuniform hill-and-dale contrast structure (6) is formed on the tread, in particular on the tread outer surface coming into contact with the ground and / or on groove flanks and / or groove bases of grooves extending in the tread.

9. Pneumatic tyre for a vehicle according to any of Claims 1 to 6, characterized in that the surface element (2) having the nonuniform hill-and-dale contrast structure (6) is formed on tyre shoulder flanks running to the sidewalls.

10. Pneumatic tyre for a vehicle according to any of Claims 1 to 9, characterized in that the surface element (2) having the nonuniform hill-and-dale contrast structure (6) forms a design element, lettering or a character or surrounds such a feature.