Vehicle tyre, method for producing a vehicle tyre and vulcanizing mould

Abstract

A vehicle tyre with at least one flat and structured element (3), which is formed on the outer surface of the tyre and contains a combination of macrostructures and microstructures which are in each case structures that are raised with respect to a base level (5), wherein the macrostructure consists of a multiplicity of ribs (4, 4', 4'') with vertex regions (7, 7', 7'') which are of a height (H) with respect to the base level (5) of 0.20 mm to 0.80 mm, wherein the microstructure covers surface elements (8) between the ribs (4, 4', 4'') and is or comprises an uneven peak-and-valley contrast structure (9), the peaks of which are of various heights, with a greatest height (h) with respect to the base level (5) that is smaller than the height of the ribs (4, 4', 4''). The peaks of the peak-and-valley contrast structure (9) are of a height (h) of 0.04 mm to 0.10 mm.

Description

[0001] 202202019 Continental Reifen Deutschland GmbH Description Vehicle tire, method for producing a vehicle tire and vulcanization mold The invention relates to a vehicle tire with at least one flat and structured element formed on its outer surface, which contains in combination macrostructures and microstructures, which are each raised structures relative to a base level, wherein the macrostructure consists of a plurality of ribs with crest regions which have a height of 0.20 mm to 0.80 mm relative to the base level, wherein the microstructure covers surface elements present between the ribs and is or has an uneven peak and valley contrast structure, the peaks of which have different heights with a greatest height relative to the base level which is less than the height of the ribs.The invention further relates to a method for producing such a vehicle tire and a vulcanization mold for vulcanizing such a vehicle tire. A vehicle tire of the type mentioned above is known from EP 2691246 B1. On its outer surface, the tire has at least one flat and structured element with adjacent ribs that have a substantially triangular cross-section with inclined rib flanks that extend on both sides of the apex of the ribs toward their base, wherein the angle of inclination of the inclined rib flanks with respect to the base level is at most 25°. The surfaces present between the ribs are referred to as residual surfaces and are covered with a microstructure with an average roughness of 5 µm to 30 µm. The width of the residual surfaces is less than or at most equal to half the height of the ribs, this height being 0.10 mm to 0.80 mm.Since the ribs have a height that is greater than the width of the remaining surfaces, the ribs should be able to deflect incoming light rays particularly effectively before they reach the remaining surfaces in order to limit the amount of light received by the remaining surfaces. The low roughness of the microstructure in the range of 5 µm to 30 µm makes the remaining surfaces appear as almost smooth surfaces that reflect incoming light well and thus have little influence on the contrast effect of the structured element. Structured elements formed on the outer surface of vehicle tires are usually in the form of characters, logos, images, etc. and, in order to be particularly visible, should be designed to contrast with the surrounding outer surfaces.In particular, these elements should be structured in such a way that they reflect little light, i.e. "capture" incoming light, so that these elements appear darker to the outside observer than the surrounding surface areas. Flat elements made of microstructures with an improved contrast effect, formed on the outer surface of vehicle tires, are known, for example, from DE 102019207908 A1. These microstructures are formed as area-wide, irregular peak and valley contrast structures that impart roughness and have a surface-related roughness value Sa according to EN ISO 25178 of 50 µm to 150 µm. Contrast structures designed in this way, with connected or merging peaks and valleys that are located at different levels, can be produced as a negative in the vulcanization mold using a laser, are easy to vent during molding of the green tire, and can be molded onto the tire in perfect condition.In the vehicle tire known from DE 102020215188 A1, the contrast structure consists of a plurality of contrast structure cells arranged in a grid pattern, each having a consistent shape when viewed from above, each of which has irregular peak and valley structures across its entire surface. The arrangement of the contrast structure cells is such that the irregular peak and valley contrast structures, viewed from above, can be transformed into one another by congruent mapping.The object of the invention, in a vehicle tire of the type mentioned at the outset with at least one structured element which has a combination of macrostructures and microstructures, is to design the surface elements present between ribs of the macrostructure with a microstructure consisting of an irregular peak and valley structure in such a way that the contrast effect of the structured elements is significantly improved by particularly effective scattering and absorption of incident light. This object is achieved according to the invention in that the peaks of the peak and valley contrast structure have a height of 0.04 mm to 0.10 mm. The height of the peaks of the peak and valley contrast structure of the microstructure, relative to the base level, is therefore at least 40 µm and up to 100 µm, with the heights of the peaks varying within this range.The surface elements between the ribs therefore contribute particularly effectively to the contrast between the surface and structured elements compared to the surrounding outer surface through the light scattering and light reflection made possible thereby, whereby the distances between the ribs of the macrostructure can be varied in one and the same structured element and the macrostructure can be designed with ribs in a variety of arrangements. In a preferred embodiment, the peak and valley contrast structure extends interrupted by the ribs but otherwise continuously over the surface or at least part of the surface of the structured element. Peak or valley structures formed on one surface element can therefore continue on the adjacent surface element, whereby a special contrast effect of the microstructure can be achieved.Furthermore, the required negative structures of such microstructures and also those of the 202202019 macrostructures can be produced particularly easily in a vulcanization mold. In a further preferred embodiment, the peak and valley contrast structure is composed of a plurality of small-area contrast structure cells arranged in a grid pattern and designed to match in plan view, with the same irregularly shaped peak and valley contrast structure being formed within each contrast structure cell. The contrast structure cells are arranged in particular such that they can be converted into one another by congruent mapping. The contrast structure cells have, for example, the shape of rectangles, in particular squares, and edge lengths of 0.80 mm to 1.50 mm in plan view.By multiplying the contrast structure cells, the peak and valley contrast structure is scalable in size and can be easily produced as a negative structure in the corresponding mold surface of a tire vulcanization mold. The surface elements between the ribs can be largely composed of complete contrast structure cells, thus ensuring a more uniform contrast effect of the surface elements provided with this microstructure. Furthermore, a preferred embodiment is one in which the ribs of the macrostructure have a height of up to 0.60 mm, preferably from 0.25 mm to 0.35 mm. In conjunction with the considerably lower height of the peaks of the microstructure, this measure achieves a particularly good contrast effect. The ribs of the macrostructure running within a structured element can have the same height and remain constant across the entire extension of the ribs.In an alternative embodiment, the ribs either have a height that varies over their extent, or ribs with different heights or different height profiles are provided. In this way, the contrast effect of the structured elements can be influenced, in particular enhanced, in a particularly advantageous manner, particularly depending on their position on the outer surface of the tire. 202202019 The course and the respective arrangement of the ribs also influence the achievable and desired contrast effect, with a multitude of possible designs in this regard. In a particularly simple embodiment, the ribs run next to one another in a hatched manner, in particular parallel or largely parallel to one another, with the surface elements covered with microstructure having a width of 0.20 mm to 0.80 mm between adjacent ribs.In a further advantageous embodiment, the ribs have successive rib sections that differ from one another in terms of their course relative to the direction of extension of the ribs, for example, running in a zigzag shape in plan view, or having a special configuration in plan view, for example as approximately equally sized, correspondingly oriented, and baseless isosceles trapezoids. To further influence and improve the contrast effect, the ribs can additionally have additional rib sections branching off from their rib sections. Advantageously, the clear distance between rib sections in adjacent ribs is at least 0.20 mm and in particular up to 0.80 mm. A certain minimum distance is advantageous in order to emphasize the contrast effect of the microstructure.The invention further relates to a method for producing a vehicle tire designed according to one or more of claims 1 to 11, comprising the following steps: creating a negative contour of at least one structured element in a molding surface of a vulcanization mold for the formative vulcanization of the vehicle tire, 202202019 wherein first the negative of the microstructure is created by laser engraving the molding surface, running over the entire surface of the structured element to be formed, then the negative structure of the macrostructure is created as depressions on the negative of the microstructure by laser engraving or milling, wherein a formative vulcanization of the green tire of the vehicle tire takes place by means of the vulcanization mold, whereby the structured element with a macrostructure of ribs and the microstructure between the ribs is embossed on the outer surface of the vehicle tire.This method enables particularly detailed and easy-to-implement creation of the negative contours of the structured elements provided on the tire on the molding surface of the vulcanization mold and subsequent detailed embossing of the structured elements during vulcanization of the green tire. The vulcanization mold designed according to the invention for the formative vulcanization of a vehicle tire designed according to one or more of claims 1 to 11 has at least one molding surface containing the negative structure of a structured element consisting of the macrostructure of ribs and the microstructure of an irregular peak and valley contrast structure. The negative structure has depressions for forming the ribs and the negative structure of the microstructure on surface elements between the ribs.Further features, advantages, and details of the invention will now be described in more detail with reference to the schematic drawing, which illustrates several exemplary embodiments. Fig. 1 shows a view of a section of a vehicle tire with structured elements, Fig. 2 shows a view of a detail of a microstructure, Fig. 3 shows a view of a detail of an embodiment of a structured element, Fig. 4 shows a plan view of a detail of a further embodiment of a structured element, Fig. 5 shows an oblique view of a partial area from Fig. 4, Fig. 6 shows a plan view of a detail of yet another embodiment of a structured element, and Fig. 7 shows an oblique view of the detail from Fig. 6.1 shows an oblique view of a circumferential section of a vehicle tire with a tread 1, sidewalls 2 and with structured flat elements 3 on the outside of the visible sidewall 2 and the outer surface of the tread 1. Structured elements 3 can also be formed, for example, on groove flanks and / or on the groove bottoms of grooves formed in the tread 1 and on the tire shoulders. The structured elements 3 can have any external shape, for example in a pictorial design, as a logo or as writing. The vehicle tire is preferably a pneumatic vehicle tire, in particular for passenger cars, vans, SUVs, light trucks, commercial vehicles, motorcycles, buses or bicycles. As shown in particular in FIGS. 3 to 7, the structured elements 3 contain a combination of macrostructures and microstructures, each of which is a raised structure relative to a base level 5.The base level 5 is the level of the unstructured area of ​​the tire outer surface having the respective structured element 3, therefore, for example, the bottom of a shallow depression formed in the sidewall 2 with a smooth or unstructured outer surface or a smooth or unstructured outer surface on the tire, for example on the sidewall 2 in the area where the structured element 3 or the structured elements 3 is or are formed. The macrostructures consist of a plurality of ribs 4 (Fig.3), 4' (Fig.4) and 4'' (Fig.6) of different arrangement and design with rib sections 4'a, 4'b, 4'c, 4''a, 4''b, 4''c (Figs.4 and 5 as well as Figs.6 and 7) of different courses, the microstructures are surface-covering, irregular mountain and valley contrast structures 9 on surface elements 8 present between the ribs 4, 4' and 4''.The ribs 4, 4', and 4'' shown in Figures 6 and 7 have in common that they have a maximum height H of 0.20 mm to 0.80 mm, preferably up to 0.60 mm, particularly preferably from 0.25 mm to 0.35 mm, relative to the base level 5. The height H of the ribs 4, 4', 4'' can also be the height averaged along their respective longitudinal extent. Preferably, all ribs 4, 4', 4'' within a structured element 3 have a consistent and largely constant height H. The ribs 4, 4', 4'' preferably have a triangular or triangular-like cross-section with two rib flanks 6, 6', 6'' sloping towards the base level 5, which each extend at an acute angle α (shown in Fig. 3 and Fig. 5) of 2° to 30°, in particular of 2° to 10°, to a perpendicular to the base level 5.The ribs 4, 4', 4'' shown in Figures 3 to 7 have apex regions 7, 7', 7'' which are designed as a narrow plateau, preferably 0.05 mm to 0.10 mm wide and running continuously over all of the ribs 4, 4', 4''. The apex regions 7, 7', 7'' can also be designed as curves connecting the rib flanks 6, 6', 6''. The described design of the ribs 4, 4', 4'' includes a corresponding design of the rib sections 4'a, 4'b, 4'c, 4''a, 4''b and 4''c, which are shown in the designs of the exemplary embodiments according to Figures 3 and 4 as well as according to Figures 6 and 7. The spaces between the ribs 4, 4', 4'' andThe surface elements 8 having their rib sections 4'a, 4'b, 4'c and 4''a, 4''b and 4''c are covered with the aforementioned microstructure, which therefore extends in each case to the lower end regions of the rib flanks 6, 6', 6'', so that the microstructure, as mentioned, is a surface-covering, irregular peak and valley contrast structure emanating from the base level 5, the peaks of which have a height h (Fig. 2) of 0.04 mm to 0.10 mm. The design is preferably such that the microstructure, interrupted by the ribs 4, 4', 4'', extends virtually continuously over the surface of the respective structured element 3. In a preferred embodiment, the peak and valley contrast structure is an overall irregular structure across all surface elements 8.In an alternative embodiment, the peak and valley contrast structure, viewed across all surface elements 8 and interrupted by the ribs 4, 4', 4'', consists of a plurality of small-area contrast structure cells arranged in a grid pattern and designed to be consistent in plan view, with the same irregularly shaped peak and valley contrast structure being formed within each counterstructure cell. The arrangement of the contrast structure cells is in particular such that they can be converted into one another by congruent mapping, for example, by parallel displacement of the contrast structure cells. The contrast structure cells, for example, have the shape of rectangles, in particular squares, in plan view and an edge length of 0.80 mm to 1.50 mm.In a further alternative embodiment, not shown separately, the microstructure extends, for example in a strip shape, also over the edge or 202202019 over a section of the edge of the structured element 3, therefore in an area where no ribs are formed. Exemplary embodiments of the arrangement and the course of the ribs 4, 4', 4'' are explained below with reference to Fig. 3, Fig. 4 with Fig. 5 and Fig. 6 with Fig. 7. Fig. 3 shows an exemplary embodiment in which the ribs 4 run next to one another and in particular parallel or largely parallel to one another. The mutual spacing a of the ribs 4 at the base level 5 is 0.20 mm to 0.80 mm. In the case of ribs 4 running parallel or essentially parallel to one another, as shown, this spacing therefore corresponds to the width of the microstructures running in strip shape between the ribs 4. In the case of the ribs 4 shown in Fig.In the embodiment shown in Figures 4 and 5, the ribs 4' each consist of rib sections 4'a, 4'b running in a regular zigzag shape and branching rib sections 4'c. The rib sections 4'a, 4'b forming the zigzag pattern therefore alternate one after the other and have extension lengths e4'a and e4'b along their central center lines, which are preferably of equal length to one another and amount to 0.20 mm to 0.40 mm, in particular 0.25 mm to 0.30 mm. The zigzag pattern of the rib sections 4'a, 4'b results in inner corner areas Ein and outer corner areas Eau. The rib sections 4'a, 4'b each enclose an interior angle β of 70° to 120° at the inner corner areas Ein; in the case of consecutive rib sections 4'a, 4'b, all interior angles are preferably of the same size.For all ribs 4', a branching rib section 4'c branches off from those inner corner regions Ein which are located on the same sides, wherein these rib sections 4'c run parallel or largely parallel to one another within a rib 4' and have corresponding extension lengths e4'c, which are 0.20 mm to 0.50 mm, preferably 0.25 mm to 0.40 mm. 202202019 Furthermore, the ribs 4' running next to each other within a structured element 3 are offset from each other with respect to their longitudinal direction of extension, such that, viewed transversely to the longitudinal direction of extension, a rib section 4'a from one rib 4' runs next to a rib section 4'b from the adjacent rib 4', wherein the rib sections 4'c branching off from the inner corner regions Ein each point in the direction of an inner corner region Ein of the adjacent rib 4'.The mutual distance a' between the mutually facing outer corner regions Eau of adjacent ribs 4', determined at the base level 5, is 0.20 mm to 0.40 mm. The microstructure formed in the surface elements 8 between the rib sections 4'a, 4'b, 4'c is indicated in a simplified design. In the embodiment shown in Fig. 6 and Fig. 7, the ribs 4'' consist of a succession of rib sections 4''a, which, viewed in plan view, are designed as approximately equal-sized, correspondingly oriented, and baseless isosceles trapezoids with respect to the longitudinal direction of the ribs 4'', and of rib sections 4'b, 4''c branching off from these. The rib sections 4''a each have an extension length e4''a determined in the extension direction of the ribs 4 of 0.40 mm to 1.00 mm, in particular of 0.50 mm to 0.80 mm.On the inside of the rib sections 4''a, the two rib sections 4''b, 4''c branch off in pairs and, in plan view, extend in a V-shape to one another, which preferably have matching extension lengths e4''b and e4''c, which, determined along the center lines of the rib sections 4''b, 4''c, amount to 0.30 mm to 0.50 mm, in particular 0.35 mm to 0.45 mm. Furthermore, the ribs 4" running alongside one another within a structured element 3 are offset from one another in their longitudinal direction, in particular such that, viewed in plan view, for each pair of ribs 4" running alongside one another, one of the rib sections 4"b or 4"c is aligned with one another. In this embodiment, too, the microstructure formed in the surface elements 8 between the ribs 4" is indicated in a simplified form in Fig.6 and Fig.7.The production of a vehicle tire with structured flat elements 3 with a combination of a macrostructure and a microstructure, as shown and described, takes place in a vulcanization mold in which the mold surface(s), for example the inside of sidewall shells, is provided with the corresponding negative contour(s). In one embodiment of the production of such a negative structure, the negative of the microstructure is first created by laser engraving at the relevant location on the mold surface, starting from the mold surface, over the entire surface of the intended structured element 3, locally deepening the mold surface accordingly. Subsequently, depressions are created in the negative of the microstructure at the relevant locations as negatives of the macrostructure, i.e., the ribs 4, 4', 4'', either also by laser engraving or by milling.If an already fully assembled green tire of a vehicle tire is placed in this vulcanization mold and vulcanized, at least one flat and structured element 3 with a corresponding micro- and macrostructure is embossed into the rubber material on the outer surface of the vehicle tire.

[0002] 202202019 List of reference symbols 1.....................Tread 2.....................Sidewall 3.....................Structured element 4, 4', 4'' ..........Rib 4'a, 4'b, 4'c .....Rib section 4''a, 4''b, 4''c ..Rib section 5.....................Base level 6, 6', 6'' ..........Rib flank 7, 7', 7'' ..........Crest area 8.....................Surface element 9.....................Peak and valley contrast structure Ein ..................Inner corner area Eau ..................Outer corner area e4'a, e4'b, e4'c ....Extension length e4''a, e4''b, e4''c ..Extension length a, a' ................Distance α, β .................Angle H ....................Height of the ribs 4, 4', 4'' h .....................Height of the peaks of the mountain and valley contrast structure m ....................Center line

Claims

202202019 Patent claims 1. Vehicle tire with at least one flat and structured element (3) formed on its outer surface, which contains in combination macrostructures and microstructures, which are each raised structures relative to a base level (5), wherein the macrostructure consists of a plurality of ribs (4, 4', 4'') with apex regions (7, 7', 7'') which have a height (H) of 0.20 mm to 0.80 mm relative to the base level (5), wherein the microstructure covers surface elements (8) present between the ribs (4, 4', 4'') and is or has an uneven peak and valley contrast structure (9), the peaks of which have different heights with a greatest height (h) relative to the base level (5) which is less than the height of the ribs (4, 4', 4''), characterized in that the peaks of the peak and valley contrast structure (9) have a height (h) from 0.04 mm to 0.10 mm. 2.Vehicle tire according to claim 1, characterized in that the peak and valley contrast structure (9) extends interrupted by the ribs (4, 4', 4") but otherwise continuously over the surface or at least part of the surface of the structured element (3).

3. Vehicle tire according to claim 1 or 2, characterized in that the peak and valley contrast structure (9) is composed of a plurality of small-area contrast structure cells joined together in a grid-like manner and designed to match in plan view, wherein the same irregularly shaped peak and valley contrast structure (9) is formed within each counterstructure cell. 202202019 4. Vehicle tire according to claim 3, characterized in that the contrast structure cells are arranged such that they can be converted into one another by congruent mapping.

5. Vehicle tire according to claim 3 or 4, characterized in that the contrast structure cells, in plan view, have the shape of rectangles, in particular squares, and edge lengths of 0.80 mm to 1.50 mm.

6. Vehicle tire according to claim 1 or 2, characterized in that the ribs (4, 4', 4'') of the macrostructure have a height (H) of up to 0.60 mm, preferably of 0.25 mm to 0.35 mm.

7. Vehicle tire according to one or more of claims 1, 2, or 6, characterized in that within a structured element (3), the ribs (4, 4', 4") of the macrostructure have equal heights (H) that remain constant over the extent of the ribs (4, 4', 4"). 8.Vehicle tire according to one or more of claims 1 to 7, characterized in that the ribs (4) run next to one another in a hatched manner, in particular parallel to one another, wherein the surface elements (8) covered with microstructure have a width of 0.20 mm to 0.80 mm between adjacent ribs (4).

9. Vehicle tire according to one or more of claims 1 to 8, characterized in that the ribs (4', 4'') have successive rib sections (4'a, 4'b, 4''a) which differ from one another with regard to their course relative to the direction of extension of the ribs (4', 4'') or which have a special configuration in plan view, for example as approximately equally sized, correspondingly oriented and baseless isosceles trapezoids. 202202019 10. Vehicle tire according to one or more of claims 1 to 9, characterized in that the ribs (4', 4'') have further rib sections (4'c, 4''c) branching off from rib sections (4'a, 4'b, 4''a).

11. Vehicle tire according to one or more of claims 1 to 10, characterized in that the clear distance between the rib sections (4'a, 4'b, 4'c, 4''a, 4''b, 4''c) of adjacently extending ribs (4', 4'') is at least 0.20 mm and in particular up to 0.80 mm. 12.A method for producing a vehicle tire designed according to one or more of claims 1 to 11, comprising the following steps: creating a negative contour of at least one structured element (3) in a molding surface of a vulcanization mold for the formative vulcanization of the vehicle tire, wherein first, the negative of the microstructure is created by laser engraving the molding surface, extending over the entire surface of the structured element (3) to be formed, then, on the negative of the microstructure, the negative structure of the macrostructure is created as depressions by laser engraving or milling, wherein a formative vulcanization of the green tire of the vehicle tire takes place by means of the vulcanization mold, whereby the structured element (3) is embossed onto the outer surface of the vehicle tire via the negative structure, thus with a macrostructure consisting of ribs (4, 4', 4'') and the microstructure between the ribs (4, 4', 4'').Vulcanization mold for the shaping vulcanization of a vehicle tire designed according to one or more of claims 1 to 11, wherein the vulcanization mold has at least one molding surface in which the negative structure of a structured element (3) consisting of the macrostructure of ribs (4, 4', 4'') and the microstructure of an uneven mountain and valley contrast structure (9) is contained. 202202019 wherein the negative structure has depressions for forming the ribs (4, 4', 4'') and the surface elements (8) between the ribs (4, 4', 4'') have the negative structure of the microstructure.

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