Vehicle tires with multi-component tread in a hybrid profile

Abstract

The invention relates to a vehicle tire (10) whose tread (12) comprises a base (20) and an outer cover layer (22) and includes on its sides a first shoulder region (24) and a second shoulder region (26) as well as a central region (28) arranged between them, wherein the cover layer (22) comprises an outer surface region (30) and an inner region (32) located underneath, wherein the surface region (30) in the first shoulder region (24) is formed by a first rubber material, wherein the surface region (30) in the second shoulder region (26) is formed by a second rubber material, wherein the inner region (32) in the central region (28) is formed by a third rubber material different from the first and second rubber materials, wherein the third rubber material has a higher storage modulus E' than the first and second rubber materials.wherein a first part of the profile blocks (16) are spiked SR profile blocks (34), wherein a second part of the profile blocks (16) are unspiked NW profile blocks (38), wherein the SR profile blocks (34) are arranged in the central area (28) to a degree of 80% or more, with respect to their number, and wherein the spikes (36) of SR profile blocks (34) arranged in the central area (28) extend into the third rubber material.

Description

[0001] The invention relates to a vehicle tire for use under winter driving conditions.

[0002] In recent decades, tire manufacturers have increasingly focused on developing new solutions for vehicle tires designed for winter driving conditions. Particularly in regions where temperatures drop below freezing during the winter months or even year-round, these tires are subjected to exceptionally high demands. In many regions, such as Scandinavia, Russia, and Canada, winter tires with particularly high friction are legally required on vehicles during the winter months. Winter tires with lower friction, such as those used in temperate regions, are unsuitable for these areas.The use of such unsuitable winter tires in severe winter driving conditions can significantly affect the driving safety of a vehicle, for example by the excessively low frictional resistance of the vehicle tires with the road surface causing the vehicle tire to slip over the road surface, which may be covered with snow or ice, so that the driver can lose control of the vehicle.

[0003] Accordingly, in recent years, two main types of winter tires have been developed for harsh winter driving conditions, tailored to the needs of each region. These tires are designed to ensure maximum power transmission in weather conditions around and well below freezing. These two tire types are designed for different temperature and snow conditions, allowing every vehicle owner to purchase the optimal product based on the temperature and snow conditions in their region. The basic choice is between studded tires and soft-compound tires.

[0004] Studded tires incorporate numerous studs, known as spikes, into their tread pattern. These spikes are typically made of steel and protrude approximately 1.5 to 2 mm from the tire surface. Because of these spikes, studded tires are particularly suitable for weather conditions with low friction between the tire and the road surface. This is the case, for example, on very smooth ice and at temperatures just below freezing, as these conditions promote high tire slippage. Since wheel spin must be prevented at all costs, studded tires are used especially in regions where the aforementioned conditions prevail. Such studded tires are known from prior art, for example, JPS 6118506 A, JPS 59124413 A, or RU 2623365 C2.

[0005] Studded tires, however, have the disadvantage that their typically high number of metal studs can cause significant road wear. Consequently, their use is even prohibited in some regions or subject to strict restrictions, such as allowing them only during the winter months. In some cases, the studs themselves are also subject to restrictions, for example, regarding their dimensions or material. Furthermore, studded tires are generally less suitable for extremely low temperatures and rough road or icy surfaces, as they cannot achieve their maximum effectiveness in these conditions and can lead to increased fuel consumption.

[0006] As an alternative to studded tires, studless winter tires, also known as Nordic winter tires or Nordic soft-compound tires (sometimes simply called soft-compound tires), were developed. These tires also increase the friction between the vehicle tire and the road surface on snow or ice compared to conventional tires and winter tires from temperate regions. Soft-compound tires have a tread surface structure whose number, density, and orientation of grooves significantly increase the tire's rolling resistance in winter driving conditions. Compared to studded tires, this type of tire achieves particularly high rolling resistance at temperatures well below freezing or on rough ice surfaces, ensuring optimal transfer of the vehicle's driving and braking forces to the road.One such soft compound tire is disclosed, for example, in WO 2015 / 086186 A1.

[0007] Despite the rubber compound used and the surface structure, soft compound tires do not achieve the traction potential of studded tires at temperatures around freezing.

[0008] In light of the above, neither soft-compound tires nor studded tires are suitable for achieving optimal results under all relevant temperature, snow, or ice conditions. While studded tires demonstrate their advantages particularly on very smooth road surfaces and at temperatures around freezing, soft-compound tires are primarily designed for rougher surfaces and temperatures well below freezing.

[0009] In recent years, however, due to global climate change, the prevailing weather conditions in regions affected by winter driving conditions have changed significantly, particularly in that the prevailing weather patterns are changing more and more rapidly. Consequently, highly variable temperature patterns and snowfall amounts have been observed in these regions over the last five years. Since it is foreseeable that weather conditions will continue to fluctuate considerably in the future, there is a corresponding need to develop a vehicle tire designed for a wide temperature range, from around to well below freezing, and which ensures optimal transmission of driving and braking forces on various road surfaces. According to the inventors, neither conventional studded tires nor soft compound tires can achieve this.

[0010] Against this background, an advantageous tire concept was proposed in DE 102022204461 A1, in which the tread structure of classic studded tires is combined with the structure of soft compound tires.

[0011] Even though excellent results can already be achieved with these vehicle tires in many cases, the inventors have identified further potential for improvement. In particular, disadvantages regarding spike durability were sometimes observed with the vehicle tires known from DE 102022204461 A1, leading to increased spike loss. Furthermore, the achievable mileage and the grip on dry and wet roads were sometimes considered insufficient.

[0012] The primary objective of the present invention was to eliminate or at least reduce the disadvantages of the prior art.

[0013] The primary objective of the present invention was to provide a vehicle tire that ensures reliable power transmission to the road even under a wide variety of winter conditions. In this context, it was also an objective of the present invention to provide a vehicle tire that synergistically combines the advantages of both soft-compound and studded tires under their respective optimal winter conditions.

[0014] In this respect, an important objective of the present invention was to further improve the vehicle tires known from DE 102022204461 A1, particularly with regard to stud durability. Furthermore, it was an objective of the present invention that the vehicle tires in question should exhibit improved mileage and optimized grip on dry and wet roads.

[0015] An important requirement was that the specified vehicle tires should be manufacturable in a time- and cost-efficient manner.

[0016] The inventors of the present invention have now found that the problems described above can be solved if the advantageous tire concept known from DE 102022204461 A1 is further developed in such a way that the studded SR profile blocks are arranged predominantly in the central area of ​​the tread and, in addition, the hybrid profile thus obtained is combined with a multi-component tread in which the tread is formed from two or more different rubber materials, as defined in the claims.

[0017] The specific design allows for the advantageous production of high-performance vehicle tires for use in a wide variety of winter conditions, ensuring safe power transmission to the road while offering advantageous stud durability, improved mileage, and optimized grip on dry and wet roads.

[0018] Although DE 102022204461 A1 considered manufacturing the different SR and NW profile blocks of the hybrid tread pattern as complete units from different rubber materials, this approach proved impractical. The manufacturing effort required for the block-specific design proved so significant that, from a practical standpoint, this idea of ​​DE 102022204461 A1 is virtually unsuitable for the mass production of vehicle tires.

[0019] The aforementioned problems are thus solved by the subject matter of the invention as defined in the claims. Preferred embodiments of the invention are described in the dependent claims and the following descriptions.

[0020] Such embodiments, which are hereinafter referred to as preferred, are combined in particularly preferred embodiments with features of other embodiments referred to as preferred. Combinations of two or more of the embodiments referred to below as particularly preferred are therefore especially preferred. Also preferred are embodiments in which a feature of one embodiment, referred to as preferred to any degree, is combined with one or more further features of other embodiments, which are referred to as preferred to any degree.

[0021] Particularly preferred embodiments of the invention are disclosed in the exemplary embodiments. Particularly preferred embodiments of the invention have two or more, preferably three or more, and most preferably four or more, of the preferred features of the invention disclosed below, which are also implemented in the exemplary embodiments.

[0022] The invention relates to a vehicle tire for use under winter driving conditions, in particular on snow and ice, with a circumferentially extending profiled tread, wherein the tread comprises a plurality of profile blocks separated from each other by profile grooves, each having a contact surface intended for contact with the roadway, the tread is a multi-component tread, comprising: i) a radially internal base comprising a base rubber material, and ii) a radially outer cover layer comprising at least two rubber materials different from the base rubber material, wherein the tread, in relation to the transverse direction of the vehicle tire which is orthogonal to the radial direction and circumferential direction, comprises on the sides a first shoulder area and a second shoulder area as well as a central area arranged in between, wherein the top layer comprises a radially outer surface area having a radially medium thickness in the range of 0.5 to 6 mm, wherein the top layer comprises a radially lower inner area, wherein the top layer consists of the surface area and the inner area, wherein the surface area in the first shoulder area is at least partially formed by a first rubber material, wherein the surface area in the second shoulder area is at least partially formed by a second rubber material, wherein the inner area in the central area is at least partially formed by a third rubber material different from the first and second rubber materials, wherein the third rubber material has a higher storage expansion modulus E' than the first rubber material and the second rubber material, wherein the storage expansion modulus E' is defined according to DIN 53535:1982-03 as the real part of the complex modulus E* according to E'=|E*| cos δ, wherein the complex modulus E* and the loss factor δ are measured according to DIN 53513:1990-03 at a temperature T=-15 °C and a compression in the range of 9.8 to 10.2 % at 10 Hz, wherein a first part of the profile blocks are spiked SR profile blocks, each having one or more spikes on the contact surface, where 80% or more of the SR profile blocks are arranged in the central area, the spikes of SR profile blocks arranged in the central area extend into the third rubber material.

[0023] The vehicle tire according to the invention is suitable for winter driving conditions and preferably even for severe winter driving conditions. In accordance with the skilled person's understanding, this includes both ambient temperatures around or below the freezing point of water at atmospheric pressure, i.e., around or below 0°C, and weather conditions that occur primarily at these temperatures, for example, ice and / or black ice and / or snow. An exemplary vehicle tire according to the invention is shown here, wherein the vehicle tire is a passenger car or truck tire, preferably a passenger car tire.

[0024] Besides its use in conventional pneumatic vehicle tires, the concept of the present invention can also be advantageously adapted to airless tires. Thus, a vehicle tire according to the invention is conceivable, wherein the vehicle tire is either a pneumatic or an airless vehicle tire, preferably a pneumatic vehicle tire.

[0025] According to the invention, the vehicle tire comprises a profiled tread, which is typically arranged between two tire sidewalls and extends along the circumferential direction of the vehicle tire. The profiled tread has a profile that typically extends over the entire circumference of the vehicle tire and, preferably, over the entire contact patch transversely to the circumferential direction, so that when the vehicle tire comes into contact with a surface, for example a road surface, the entire contact area of ​​the vehicle tire with the surface is formed by the profile.

[0026] The tread grooves, in accordance with expert understanding, comprise any recesses separating the tread blocks. These can be, for example, transverse grooves, circumferential grooves, and diagonal grooves, the designations referring to the circumferential direction of the vehicle tire along which the profiled tread extends. An exemplary vehicle tire according to the invention is thus presented, wherein the tread grooves are selected from the group consisting of transverse grooves, circumferential grooves, and diagonal grooves. Transverse grooves and diagonal grooves are elongated recesses that are oriented essentially transversely, for example at an angle in the range of 80° to 90°, or diagonally, for example at an angle between 10° and 80°, to the circumferential direction.Circumferential grooves are defined as elongated recesses extending along the circumference, for example, at an angle between 0° and 10°. The profile grooves may, for instance, have a substantially V-shaped, U-shaped, or substantially rectangular cross-section. In most cases, the depth of the central circumferential grooves will be approximately 9 mm and, in the eyes of a person skilled in the art, will determine the overall profile depth. In particular, the SR and NW profile blocks do not have grooves with a comparable or even greater depth than the profile grooves, as this would, in the eyes of a person skilled in the art, create two separate profile blocks and effectively make the corresponding groove a single profile groove.

[0027] Within the scope of the present invention, the surface of the profile blocks that touches the substrate in later use is referred to as the contact surface intended for roadway contact.

[0028] In accordance with DE 102022204461 A1, the profiled tread comprises a hybrid profile consisting of studded profile blocks, so-called SR profile blocks, and unstudded profile blocks, so-called NW profile blocks.

[0029] Insofar as reference is made below to the height of the profile blocks, the profile grooves define the mean height of the profile blocks via their groove depth, wherein the mean height of the profile blocks within the scope of the present invention is defined as the mean height of the side walls of each profile block relative to the surrounding profile grooves, averaged over the entire circumference of the respective profile block.

[0030] Insofar as reference is made below to the mean depth of a groove and the relative depth ratios, these can, in practice, be estimated qualitatively by a person skilled in the art in the vast majority of cases very easily. In detail, however, the mean depth of a groove is considered, in accordance with the skilled person's understanding, to be the depth averaged over the entire opening area of ​​the groove relative to the contact surface, so that, for example, a groove with a V-shaped profile will have a smaller mean depth than a groove with a rectangular profile, even if it has the same maximum depth.

[0031] According to the invention, a first part of the tread blocks is designed as studded SR tread blocks. The abbreviation SR, used for easier identification, stands for "stud tire" and refers to the fact that these tread blocks comprise at least one stud and are modeled on tread blocks known from studded tires. In accordance with the skilled person's understanding, the SR tread blocks can each also have several studs. In particular, the SR tread blocks can each comprise different numbers of studs. However, a vehicle tire according to the invention is preferred in which the SR tread blocks each have exactly one stud.

[0032] According to the invention, a second part of the tread blocks is designed as unstudded NW tread blocks, i.e., they do not include any spikes. The abbreviation NW, used for easier identification, stands for "Nordic Winter Tire". According to the invention, the NW tread blocks have an NW surface structure with at least one groove-like indentation.

[0033] A person skilled in the art understands that, in order to exploit the advantages of the hybrid construction as fully as possible, it is advantageous to utilize the corresponding tread blocks as much as possible. A preferred vehicle tire according to the invention therefore has a combined proportion of SR tread blocks and NW tread blocks of 80% or more, preferably 90% or more, particularly preferably 95% or more, and most preferably substantially 100%.

[0034] A vehicle tire according to the invention is generally preferred, wherein the proportion of SR tread blocks is 5% or more, preferably 10% or more, particularly preferably 20% or more, based on the total number of tread blocks and / or wherein the proportion of SR tread blocks is in the range of 5 to 40%, preferably in the range of 10 to 30%, particularly preferably in the range of 15 to 20%, based on the total number of tread blocks.

[0035] In principle, a vehicle tire according to the invention is additionally or alternatively preferred, wherein the proportion of NW profile blocks is 30% or more, preferably 40% or more, particularly preferably 50% or more, based on the total number of profile blocks and / or wherein the proportion of NW profile blocks is in the range of 60 to 95%, preferably in the range of 70 to 90%, particularly preferably in the range of 75 to 85%, based on the total number of profile blocks.

[0036] Particularly preferred is a vehicle tire according to the invention, wherein the proportion of SR profile blocks in the central area is 10% or more, preferably 20% or more, particularly preferably 25% or more, based on the total number of profile blocks in the central area, and / or wherein the proportion of SR profile blocks in the central area is 20 to 65%, preferably in the range of 30 to 55%, particularly preferably in the range of 40 to 45%, based on the total number of profile blocks in the central area.

[0037] In principle, a vehicle tire according to the invention is preferred with regard to the construction of corresponding vehicle tires, wherein the arrangement of the SR profile blocks and / or the NW profile blocks, preferably the SR profile blocks, in the profiled tread is carried out according to an algorithm, for example in a pattern repeating along the circumference.

[0038] To define the invention, the tread is divided in the transverse direction, i.e., in the direction perpendicular to the radial and circumferential directions, into three areas: a central area flanked on both sides by a shoulder area. In vehicle tires according to the invention, the dimensions of these areas, i.e., the portions of the tread assigned to the respective areas, depend on the distribution of the different rubber materials, as further specified below. The inventors have succeeded in identifying preferred dimensions for the corresponding areas, with particular preference being to ensure that the shoulder areas are not too narrow while simultaneously providing a sufficiently wide central area.A preferred vehicle tire according to the invention is one in which the first shoulder area and / or the second shoulder area, preferably the first shoulder area and the second shoulder area, extend in the transverse direction over 5% or more, preferably 10% or more, particularly preferably 15% or more, of the tread, and / or in which the first shoulder area and / or the second shoulder area, preferably the first shoulder area and the second shoulder area, extend in the transverse direction over a length in the range of 0.05*Q to 0.3*Q, preferably in the range of 0.1*Q to 0.28*Q, particularly preferably in the range of 0.15*Q to 0.25*Q, of the tread, wherein Q is the total width of the tread in the transverse direction.Preferably, or alternatively, a vehicle tire according to the invention is used, wherein the central area extends in the transverse direction over 30% or more, preferably 40% or more, particularly preferably 50% or more, of the tread, and / or wherein the central area extends in the transverse direction over a length in the range of 0.4*Q to 0.9*Q, preferably in the range of 0.44*Q to 0.8*Q, particularly preferably in the range of 0.5*Q to 0.7*Q, of the tread, wherein Q is the total width of the tread in the transverse direction.

[0039] According to the invention, the SR tread blocks, as a concretization of the concept of DE 102022204461 A1, are arranged predominantly in the central area. The inventors have found that this makes the spikes particularly effective. The inventors have identified it as particularly advantageous to place the spikes as far as possible in the central area. A preferred vehicle tire according to the invention is therefore one in which the SR tread blocks are arranged in the central area to 90% or more, preferably 95% or more, particularly preferably 98% or more, and most preferably substantially 100%, in relation to their number. A preferred additional or alternative vehicle tire according to the invention is one in which the first shoulder area and / or the second shoulder area, preferably the first shoulder area and the second shoulder area, comprise fewer than 10, preferably fewer than 5, and most preferably none, SR tread blocks in relation to the entire tire circumference.

[0040] The vehicle tire according to the invention comprises a tread which is fundamentally constructed in a so-called cap-base design and includes a radially outer cover layer ("cap") and an underlying base. A corresponding basic structure consisting of a "cap" and a "base" is generally known to those skilled in the art. An exemplary vehicle tire according to the invention is one in which the base has a radial thickness in the range of 0.4 to 5 mm, preferably in the range of 0.6 to 4 mm, particularly preferably 0.8 to 3 mm, and most preferably 1.0 to 2 mm.

[0041] According to the preceding definition, the base material comprises a rubber material, which, for the purpose of clear identification, is referred to as the base rubber material. For the vast majority of applications, a vehicle tire according to the invention is preferred, wherein the base material is formed by the base rubber material to 90% or more, preferably 95% or more, particularly preferably 98% or more, and most preferably substantially 100%, based on the mass of the base material.A preferred vehicle tire according to the invention is wherein the basic rubber material is selected from the group consisting of rubber materials with a storage modulus E' in the range of 10 to 40 MPa, preferably in the range of 15 to 35 MPa, particularly preferably in the range of 20 to 30 MPa, and / or wherein the basic rubber material is selected from the group consisting of rubber materials with a Shore A hardness in the range of 53 to 72, preferably in the range of 58 to 68, particularly preferably in the range of 60 to 65.

[0042] Furthermore, it is important for the vehicle tires according to the invention that the cover layer comprises at least two different rubber materials and is therefore a multi-component cap.

[0043] A key aspect of the present invention is that different rubber materials are used in the different areas of the cover layer in order to optimize the performance characteristics of the vehicle tires according to the invention.

[0044] To clearly define the vehicle tires according to the invention, in addition to the division into the central area and the shoulder areas in the transverse direction, a further conceptual subdivision of the plywood in the radial direction is also used. The plywood is subdivided radially into an outer surface area, which also includes the contact surface intended for road contact, and an inner area located below, i.e., further inwards in the radial direction.

[0045] The radially outer surface area forms the outer surface of the tread and, according to the invention, has a specific average thickness, thus extending only a limited distance into the ply. A vehicle tire according to the invention is generally preferred, wherein the radial surface area has an average thickness in the range of 1 to 5 mm, particularly preferably in the range of 2 to 4.5 mm, and most preferably in the range of 3 to 4 mm.

[0046] The inner area below the surface layer, by definition, constitutes the remaining part of the outer layer. The inventors have identified it as particularly preferred if the surface layer is matched to the overall tread depth in such a way that the inner layer is exposed during wear when only a certain tread depth remains, preferably about 4 mm. A vehicle tire according to the invention is preferred in which the surface layer has a radial average thickness in the range of (T). R - 6 mm) to (T R - 2 mm), preferably in the range of (T R - 5 mm) to (T R - 3 mm), particularly preferably in the range of (T R - 4.5 mm) to (T R - 3.5 mm), wherein T R The mean tread depth of the deepest circumferential tread groove in the profiled tread.

[0047] In summary, the top layer can thus be conceptually divided into three areas in the transverse direction and into two areas in the radial direction, resulting in a total of six areas (3x2) for the top layer in the radial section: - the surface area in the first shoulder area; - the surface area in the second shoulder area; - the surface area in the central area; - the inner area in the first shoulder area; - the inner area of ​​the second shoulder region; and - the interior in the central area.

[0048] The composition of the top layer can be defined with reference to these areas.

[0049] It is defined above that the surface area in the first shoulder region is formed at least partially by a first rubber material, the surface area in the second shoulder region is formed at least partially by a second rubber material, and the interior area in the central region is formed at least partially by a third rubber material different from the first and second rubber materials, wherein these rubber materials are in a specific ratio of properties to each other, as further disclosed below.

[0050] Here, it is defined that the relevant areas comprise the respective rubber materials, so that in principle there is room for further components. This takes into account the fact that, at least theoretically, other components may also be present that are not rubber materials, even though this is not preferred. Furthermore, this formulation also considers that in the boundary areas of the shoulder regions and the central region, or at the transition between the surface region and the interior region, another rubber material from an adjacent region may protrude into the area under consideration. However, it is preferred if the respective regions are formed as largely as possible from the respective rubber material.A preferred vehicle tire according to the invention is wherein the surface area in the first shoulder area is formed by the first rubber material to 50% or more, preferably 70% or more, particularly preferably 90% or more, and especially preferably 95% or more, based on the mass of the corresponding surface area, and / or wherein the surface area in the second shoulder area is formed by the second rubber material to 50% or more, preferably 70% or more, particularly preferably 90% or more, and especially preferably 95% or more, based on the mass of the corresponding surface area, and / or wherein the inner area in the central area is formed by the third rubber material to 50% or more, preferably 70% or more, particularly preferably 90% or more, and especially preferably 95% or more, based on the mass of the corresponding inner area.

[0051] The person skilled in the art understands that the remaining three areas will also comprise rubber materials, which can be designated and which, in preferred embodiments, can be correlated with the other rubber materials with regard to their property profile, with the above statements regarding mass fractions applying accordingly. It is thus a vehicle tire according to the invention, wherein the inner area in the first shoulder region is formed at least partially by a fourth rubber material, and / or wherein the inner area in the second shoulder region is formed at least partially by a fifth rubber material, and / or wherein the surface area in the central region is formed at least partially by a sixth rubber material.A preferred vehicle tire according to the invention is therefore one in which the inner area in the first shoulder area is formed by the fourth rubber material to 50% or more, preferably 70% or more, particularly preferably 90% or more, and especially preferably 95% or more, based on the mass of the corresponding inner area, and / or in which the inner area in the second shoulder area is formed by the fifth rubber material to 50% or more, preferably 70% or more, particularly preferably 90% or more, and especially preferably 95% or more, based on the mass of the corresponding inner area, and / or in which the surface area in the central area is formed by the sixth rubber material to 50% or more, preferably 70% or more, particularly preferably 90% or more, and especially preferably 95% or more, based on the mass of the corresponding outer area.

[0052] The person skilled in the art understands that the foregoing largely consists of clarifications that were omitted from the more extensive formulation of the invention for the sake of brevity. Accordingly, if there are no constraints on conciseness, it is reasonable to understand the corresponding vehicle tires to include all six areas of the plywood and the corresponding rubber materials, which exhibit certain interdependencies and relationships to one another, preferably with the same minimum mass fractions of the respective rubber materials in the corresponding areas.

[0053] A central aspect of the present invention is that the first rubber material and the second rubber material, i.e. the rubber materials in the surface areas of the shoulders, are formed by rubber materials that are less stiff than the third rubber material, which is encompassed in the central area by the inner area.

[0054] This allows for surface property profiles to be achieved in the shoulder areas with few or preferably no spikes, similar to those known from Nordic winter tires, which in turn allows for excellent grip properties on wet and dry roads.

[0055] Conversely, the stiffer third rubber material ensures advantageous retention of the spikes in the central area, which is further expressed in the preceding definition by the fact that the spikes from SR profile blocks arranged in the central area extend into the third rubber material. A vehicle tire according to the invention is relevant for essentially all embodiments, wherein the spikes from the majority, preferably all, of the SR profile blocks arranged in the central area extend into the third rubber material.

[0056] A preferred vehicle tire according to the invention is one in which the spike has a spike foot and a spike waist, wherein the spike waist is located at the boundary of the surface area with respect to the radial direction.

[0057] For the sake of good spike fixation, a vehicle tire according to the invention is preferred, wherein the spikes of SR profile blocks arranged in the central area extend into the third rubber material over 10% or more, preferably 20% or more, particularly preferably 30% or more, of their length, based on the length of the spikes. Additionally or alternatively, a vehicle tire according to the invention is also preferred, wherein the SR profile blocks are designed such that the spike(s) experience a deflection from their initial position of 11° or less, preferably 9° or less, particularly preferably 7° or less, as a result of a force of 100 N or more acting tangentially at the tip of the spike.

[0058] According to the invention, less stiff rubber materials are used in the superficial shoulder areas and a stiffer rubber material is used in the underlying central area in order to optimize the driving characteristics, especially under winter conditions, while also advantageously increasing the durability of the spikes.

[0059] Within the scope of the present invention, the stiffnesses are expressed in accordance with the skilled person's understanding via the storage expansion modulus E'. Within the scope of the present invention, this is defined according to DIN 53535:1982-03 as the real part of the complex modulus E* according to the formula E' = |E*| cos δ. The required quantities, i.e., the complex modulus E* and the loss factor δ, are determined at a temperature T = -15°C according to DIN 53513:1990-03 with a pre-strain / compression in the range of 9.8% to 10.2%, whereby the strain is varied at a frequency of 10 Hz. Before the measurement, the specimen is conditioned. This conditioning takes place at a temperature T = 23°C ±2°C and a strain / compression in the range of 8% to 32%, whereby this strain variation is carried out at a frequency of 10 Hz.

[0060] The inventors consider it advantageous to provide a relatively strong stiffness gradient. A preferred option is a vehicle tire according to the invention, wherein the third rubber material has a storage modulus E' that is 10% or more, preferably 20% or more, particularly preferably 35% or more higher than that of the first rubber material and the second rubber material.

[0061] The increased stiffness is regularly accompanied by a greater hardness of the rubber material. Against this background, a vehicle tire according to the invention is also preferred, wherein the third rubber material has a greater Shore A hardness at 23 °C, preferably 5% or more, more preferably 10% or more, and particularly preferably 20% or more, than the first and second rubber materials.

[0062] In addition to the first, second and third rubber materials, the rubber materials in the remaining areas of the top layer can also be compared to the first, second and third rubber materials with regard to their stiffness and / or hardness.

[0063] The inventors have identified three particularly preferred variants, namely: I) the use of less stiff rubber materials in all surface areas in combination with stiffer rubber materials in all interior areas; II) the use of less stiff rubber materials in the entire shoulder area in combination with stiffer rubber materials in the entire central area, and III) the use of less stiff rubber materials in all surface areas of the shoulder areas in combination with stiffer rubber materials in the entire central area, wherein the inner areas of the shoulder areas may preferably be designed with a medium stiffness or even be formed from the basic rubber material.

[0064] The relative stiffnesses can be expressed for the aforementioned variants. For many applications, a vehicle tire according to the invention is therefore preferred, wherein the third rubber material has a higher storage modulus E', preferably 10% or more, more preferably 20% or more, and particularly preferably 35% or more, than the fourth rubber material, and / or wherein the third rubber material has a higher storage modulus E', preferably 10% or more, more preferably 20% or more, and particularly preferably 35% or more, than the fifth rubber material, and / or wherein the third rubber material has a higher storage modulus E', preferably 10% or more, more preferably 20% or more, and particularly preferably 35% or more, than the sixth rubber material.

[0065] Particularly for variant I) but also for variant III), a vehicle tire according to the invention is additionally or alternatively preferred, wherein the fourth rubber material has a higher storage modulus E', preferably 10% or more, preferably 20% or more, particularly preferably 35% or more, than the first rubber material and the second rubber material, and / or wherein the fifth rubber material has a higher storage modulus E', preferably 10% or more, preferably 20% or more, particularly preferably 35% or more, than the first rubber material and the second rubber material.

[0066] The foregoing statements can also be applied analogously to the hardness of the respective rubber materials, with the Shore A hardness being determined at 23 °C in each case. A preferred or alternatively, therefore, is a vehicle tire according to the invention, wherein the third rubber material has a greater Shore A hardness, preferably 5% or more, more preferably 10% or more, and particularly preferably 20% or more, than the fourth rubber material, and / or wherein the third rubber material has a greater Shore A hardness, preferably 5% or more, more preferably 10% or more, and particularly preferably 20% or more, than the fifth rubber material, and / or wherein the third rubber material has a greater Shore A hardness, preferably 5% or more, more preferably 10% or more, and particularly preferably 20% or more, than the sixth rubber material.Preferably, or alternatively, a vehicle tire according to the invention is also used, wherein the fourth rubber material has a greater Shore A hardness, preferably 5% or more, more preferably 10% or more, and particularly preferably 20% or more, than the first and second rubber materials, and / or wherein the fifth rubber material has a greater Shore A hardness, preferably 5% or more, more preferably 10% or more, and particularly preferably 20% or more, than the first and second rubber materials.

[0067] The three preferred variants described above can be effectively defined by designating the less stiff rubber materials, such as the first and second rubber materials, as category A rubber materials and the stiffer rubber materials as category B rubber materials.

[0068] Category A rubber materials have lower stiffnesses and hardnesses than category B rubber materials, although this classification does not include information about the relative stiffnesses or hardnesses of category A and category B rubber materials among each other, which may be the same or different within the category.

[0069] For variant I), a vehicle tire according to the invention is preferred, wherein the first rubber material, the second rubber material and the sixth rubber material are formed by a rubber material of category A and wherein the third rubber material, the fourth rubber material and the fifth rubber material are formed by a rubber material of category B.

[0070] Alternatively, for variant II) a vehicle tire according to the invention is preferred, wherein the first rubber material, the second rubber material, the fourth rubber material and the fifth rubber material are formed by a rubber material of category A and wherein the third rubber material and the sixth rubber material are formed by a rubber material of category B.

[0071] Alternatively, for variant III) a vehicle tire according to the invention is preferred, wherein the first rubber material and the second rubber material are formed by a rubber material of category A and wherein the third rubber material, the fourth rubber material, the fifth rubber material and the sixth rubber material are formed by a rubber material of category B, or wherein the first rubber material, the second rubber material, the fourth rubber material and the fifth rubber material are formed by a rubber material of category A and wherein the third rubber material and the sixth rubber material are formed by a rubber material of category B, or wherein the first rubber material and the second rubber material are formed by a rubber material of category A, wherein the third rubber material and the sixth rubber material are formed by a rubber material of category B, and wherein the fourth rubber material and the fifth rubber material are formed by the basic rubber material.

[0072] In principle, vehicle tires according to the invention are preferred, wherein the rubber materials of category A are selected from the group consisting of rubber materials with a storage modulus E' in the range of 5 to 20 MPa, preferably in the range of 5 to 15 MPa, particularly preferably in the range of 5 to 10 MPa, and / or wherein rubber materials of category A are selected from the group consisting of rubber materials with a Shore A hardness at 23 °C in the range of 40 to 55, preferably in the range of 43 to 53, particularly preferably in the range of 45 to 49.

[0073] In principle, vehicle tires according to the invention are also preferred, either additionally or alternatively, wherein rubber materials of category B are selected from the group consisting of rubber materials with a storage modulus E' in the range of 10 to 40 MPa, preferably in the range of 15 to 25 MPa, particularly preferably in the range of 18 to 22 MPa, and / or wherein rubber materials of category B are selected from the group consisting of rubber materials with a Shore A hardness in the range of 53 to 72, preferably in the range of 56 to 68, particularly preferably in the range of 58 to 62.

[0074] Even though it would theoretically be possible to use six or even more different rubber materials, taking into account the required stiffness and hardness ratios, the inventors believe that, in terms of manufacturing efficiency, it is preferable to use the same rubber materials for different areas that have similar stiffness and hardness requirements.

[0075] In the variant I) disclosed above, a vehicle tire according to the invention is preferred, wherein the first rubber material and the second rubber material, preferably the first rubber material, the second rubber material and the sixth rubber material, are essentially identical, and / or wherein the fourth rubber material and the fifth rubber material, preferably the third rubber material, the fourth rubber material and the fifth rubber material, are essentially identical.

[0076] In the variant II) disclosed above, a vehicle tire according to the invention is preferred, wherein the first rubber material and the second rubber material are identical, and / or wherein the fourth rubber material and the fifth rubber material are essentially identical, wherein the first rubber material, the second rubber material, the fourth rubber material and the fifth rubber material are particularly preferably essentially identical, and / or wherein the third rubber material and the sixth rubber material are identical.

[0077] In the variant III) disclosed above, a vehicle tire according to the invention is preferred, wherein the first rubber material and the second rubber material are essentially identical, and / or wherein the third rubber material and the sixth rubber material are essentially identical, and / or wherein the fourth rubber material and the fifth rubber material are essentially identical. In the variant III) disclosed above, a vehicle tire according to the invention is particularly preferred, wherein the fourth rubber material is essentially identical to the basic rubber material, and / or wherein the fifth rubber material is essentially identical to the basic rubber material.

[0078] The person skilled in the art understands that an actual chemical identity is not absolutely necessary, but that similar stiffnesses are sought, so that the above characteristics can also be expressed via a similarity in the storage expansion modulus E'.

[0079] For the variant I) disclosed above, a vehicle tire according to the invention is preferred, wherein the first rubber material and the second rubber material, preferably the first rubber material, the second rubber material and the sixth rubber material, have a storage modulus E' which differs by less than 5%, preferably less than 2%, and / or wherein the fourth rubber material and the fifth rubber material, preferably the third rubber material, the fourth rubber material and the fifth rubber material, have a storage modulus E' which differs by less than 5%, preferably less than 2%.

[0080] In the variant II) disclosed above, a vehicle tire according to the invention is preferred, wherein the first rubber material and the second rubber material have a storage modulus E' which differs by less than 5%, preferably less than 2%, and / or wherein the fourth rubber material and the fifth rubber material have a storage modulus E' which differs by less than 5%, preferably less than 2%, wherein the first rubber material, the second rubber material, the fourth rubber material and the fifth rubber material particularly preferably have a storage modulus E' which differs by less than 5%, preferably less than 2%, and / or wherein the third rubber material and the sixth rubber material have a storage modulus E' which differs by less than 5%, preferably less than 2%.

[0081] In the variant III) disclosed above, a vehicle tire according to the invention is preferred, wherein the first rubber material and the second rubber material have a storage modulus E' which differs by less than 5%, preferably less than 2%, and / or wherein the third rubber material and the sixth rubber material have a storage modulus E' which differs by less than 5%, preferably less than 2%, and / or wherein the fourth rubber material and the fifth rubber material have a storage modulus E' which differs by less than 5%, preferably less than 2%.For the variant III) disclosed above, a vehicle tire according to the invention is particularly preferred, wherein the fourth rubber material and the basic rubber material have a storage modulus E' that differs by less than 5%, preferably less than 2%, and / or wherein the fifth rubber material and the basic rubber material have a storage modulus E' that differs by less than 5%, preferably less than 2%. Therefore, a vehicle tire according to the invention is particularly preferred for the variant III) disclosed above, wherein the basic rubber material is a rubber material of category B.

[0082] The NW profile blocks are preferably designed as disclosed in DE 102022204461 A1 as advantageous or preferred.

[0083] A preferred vehicle tire according to the invention is one in which the NW surface structuring comprises two or more first groove-like depressions and two or more second groove-like depressions, wherein the first groove-like depressions each have a mean groove depth in the range of 20 to 90% of the mean height of the NW profile block, and wherein the second groove-like depressions each have a mean groove depth of less than 20% of the mean height of the NW profile block.

[0084] Particularly preferred is a vehicle tire according to the invention, wherein the first groove-like depressions each have a mean groove depth in the range of 25 to 80%, preferably in the range of 30 to 70%, particularly preferably in the range of 35 to 60%, of the mean height of the NW profile block, and / or wherein the second groove-like depressions each have a mean groove depth of less than 15%, preferably less than 10%, particularly preferably less than 5% of the mean height of the NW profile block.

[0085] Particularly preferred is, additionally or alternatively, a vehicle tire according to the invention, wherein the first groove-like depressions each have a mean groove width in the range of 0.35 to 0.65 mm, preferably in the range of 0.4 to 0.6 mm, particularly preferably in the range of 0.45 to 0.55 mm, and / or wherein the second groove-like depressions each have a mean groove width in the range of 0.02 to 1.4 mm, preferably in the range of 0.06 to 1.2 mm, particularly preferably in the range of 0.1 to 1 mm.

[0086] Particularly preferred is, additionally or alternatively, a vehicle tire according to the invention, wherein the NW surface structuring of the NW profile blocks comprises 3 or more, preferably 4 or more, particularly preferably 5 or more, first groove-like depressions, and / or wherein the NW surface structuring of the NW profile blocks comprises 3 or more, preferably 4 or more, particularly preferably 5 or more, second groove-like depressions.

[0087] Building upon the teachings of DE 102022204461 A1, the SR tread blocks can also be designed with groove-like recesses. A preferred vehicle tire according to the invention is thus one in which the SR tread blocks each have an SR surface structuring on the contact surface, wherein the SR surface structuring comprises two or more, preferably two or three, third groove-like recesses. A particularly preferred vehicle tire according to the invention is one in which the third groove-like recesses each have a mean groove depth in the range of 10 to 60%, preferably in the range of 15 to 50%, and particularly preferably in the range of 20 to 40%, of the mean height of the SR tread block, and / or wherein the third groove-like recesses each have a mean groove width in the range of 0.35 to 0.65 mm, preferably in the range of 0.4 to 0.6 mm, and particularly preferably in the range of 0.45 to 0.55 mm.

[0088] With regard to the structure of all groove-like depressions, a vehicle tire according to the invention is generally preferred, wherein the first groove-like depressions and / or the second groove-like depressions and / or the third groove-like depressions, preferably all groove-like depressions, are designed at least sectionally as helical and / or stepped grooves, preferably as helical grooves.

[0089] The invention and preferred embodiments of the invention are explained and described in more detail below with reference to the accompanying figures. These figures show: Fig. 1 a first schematic representation of the profiled tread of a vehicle tire according to the invention in a preferred embodiment; Fig. 2 a second schematic representation of the profiled tread of a vehicle tire according to the invention in a preferred embodiment; Fig. 3 a schematic visualization of the areas of a tread of a vehicle tire according to the invention in radial section; Fig. 4 a first schematic visualization of the distribution of rubber materials in a tread of a vehicle tire according to the invention in radial section by a first preferred embodiment; Fig. 5 a second schematic visualization of the distribution of rubber materials in a tread of a vehicle tire according to the invention in radial section by a second preferred embodiment; Fig. 6 a third schematic visualization of the distribution of rubber materials in a tread of a vehicle tire according to the invention in radial section by a third preferred embodiment; and Fig. 7 A fourth schematic visualization of the distribution of rubber materials in a tread of a vehicle tire according to the invention in radial section by a fourth preferred embodiment.

[0090] Fig. Figure 1 shows a highly simplified representation of a section of a profiled tread 12 of a vehicle tire 10 according to the invention, the construction of which from various rubber materials can be carried out, for example, as shown in the Fig. 4 to 7 are shown.

[0091] In the Fig. Figure 1 shows a vehicle tire 10 for use under severe winter driving conditions in a top view of the profiled tread 12. The profiled tread 12 comprises a plurality of profile blocks 16, which are separated from each other by profile grooves 14. In the lower part of the Fig. Figure 1 shows that the tread 12 can be conceptually divided into three areas along the transverse direction of the vehicle tire 10, namely the first shoulder area 24 and the second shoulder area 26, between which the central area 28 is arranged. In the schematic example shown, Fig. The illustrated section of the tread 12 comprises sixteen profile blocks 16. Of these, thirteen profile blocks 16 are designed as NW profile blocks 38, which are unspiked and each have an NW surface structuring comprising three first groove-like depressions 40 and four second groove-like depressions 42. The remaining three profile blocks 16 are designed as SR profile blocks 34 and each is provided with a spike 36 and third groove-like depressions 44. In the example shown, the SR profile blocks 34 are arranged exclusively in the central area 28, where, according to the inventors, they are particularly effective. The SR profile blocks 34 and the unspiked NW profile blocks 38 are separated from each other by profile grooves 14.

[0092] The Fig. Figure 2 still represents a schematic representation of a section of a tread 12, but with regard to the design of the tread blocks 16 and the tread grooves 14, it is more closely based on a tread profile such as can be used in modern vehicle tires 10. The one in Fig. The tread profile shown in Figure 2 consists exclusively of SR profile blocks 34 and NW profile blocks 38, with the respective groove-like depressions hidden for clarity. Also in the Fig. The first shoulder area 24 and the second shoulder area 26, as well as the central area 28 in between, are shown, with the multi-component tread strip of the Fig. 2 can be carried out, for example, as described in the Fig. 4 to 7 is revealed.

[0093] Fig. Figure 3 shows a schematic cross-sectional view through a multi-component tread strip to be used according to the invention in radial section and serves to better understand the various conceptual sub-areas of the tread strip and the rubber materials present in these sub-areas. The tread strip 12 comprises a base 20, which in the example shown consists essentially entirely of a base rubber material B. The outermost radial layer 22 is conceptually divided into two areas: the outer radial surface area 30, which also forms the contact surface 18 intended for road contact, and the inner radial area 32. For the sake of clarity, in Fig. 3. The profile blocks 16 or the profile grooves 14 have been omitted. It is clearly evident that, in addition to the base 20, the conceptual division into the first shoulder area 24, the second shoulder area 26, and the central area 28 on the one hand, and the surface area 30 or the inner area 32 on the other, forms a total of seven regions of the multi-component tread strip. Fig. The number 3 is indicated by Roman numerals, showing how the different rubber materials, i.e., the basic rubber material B and the first to sixth rubber materials I, II, III, IV, V, VI, are distributed in the conceptual sub-areas. The surface area 30 forming the contact surface 18 is, in the example shown, the Fig. 3, for example, 4 mm thick in the radial direction, so that with a total profile depth, measured at the central profile groove 14, of 8 mm, a structure results in an abrasion of 4 mm of the profile that would expose the inner area 32.

[0094] In the Fig. Figure 3 further shows that a schematically indicated spike 36 extends through the surface area 30 in the central area 28 and into the inner area 32, where it is fixed in the third rubber material III. The spike is only schematically indicated and in reality will have a spike base and a spike waist, with the transition between rubber materials III and VI located in the area of ​​the spike waist. The rubber materials present in the first shoulder area 24 and in the second shoulder area 26 in the surface area 30, i.e., the first rubber material I and the second rubber material II, are designed as rubber materials also used in Nordic winter tires and have a lower stiffness than the third rubber material III, which can be expressed via the storage modulus E'.

[0095] The Fig. Figure 3 helps to visualize the areas of the tread 12 used within the scope of the present invention, both to provide a design guide for vehicle tires 10 according to the invention and to indicate whether a given vehicle tire 10 meets the relevant requirements. In accordance with the understanding of those skilled in the art, it is advantageously possible, but by no means necessary, to define specific limits for the respective areas. Rather, this conceptual design can be seen as a template that can be applied to various tire designs to implement the teachings of the present invention. For example, a person skilled in the art who wishes to design a vehicle tire 10 according to the invention can adjust the thickness of the surface area 30 to the respective application requirements, provided that the thickness is within the range defined above.Furthermore, the expert also has design discretion regarding the configuration of the various areas along the transverse direction. The actual allocation to the different areas will ultimately depend on the distribution of the different rubber materials in the tread 12 and the positioning of the spike 36.

[0096] Even for an existing vehicle tire size 10, thanks to the in Fig. According to the template described in section 3, a person skilled in the art can determine beyond doubt whether a vehicle tire 10 makes use of the present teaching. For this purpose, it is only necessary to consider the position of the spikes 36 and the distribution of the different rubber materials in the tread 12 and to check whether the corresponding template of the Fig. 3 is applicable under the boundary conditions of the positioning of the spikes 36 and the distribution of the rubber materials on the corresponding vehicle tires 10, or not.

[0097] The Fig. Figures 4 to 7 show preferred embodiments for implementing the multi-component tread strip to be used according to the invention. Starting from the illustration of the Fig. 3. The different areas have been marked with hatching, where identical hatching indicates that the same rubber material is used.

[0098] In Fig. Figure 4 shows that the entire surface area 30 of the tread 12 is formed across its entire width by a less stiff rubber material, while the areas of the inner region 32 located between the surface area 30 and the base 20 are formed by a rubber material with increased stiffness and hardness. This corresponds to variant I) described above.

[0099] Fig. Figure 5 shows the variant II) described above in a preferred embodiment. Here, the rigid rubber material forms not only the inner region 32 in the central region 28, but also the surface region 30 in the central region 28. This arrangement ensures a particularly secure fixation of the spikes 36 in the tread 12. The driving characteristics of the vehicle tire 10 are advantageously enhanced by the use of the less rigid rubber materials in the first shoulder region 24 and in the second shoulder region 26.

[0100] Fig. Figure 6 shows a variation of the Fig. 5, which corresponds to the variant III) discussed above. This differs from the Fig. 5 such that the lower parts of the top layer 22 in the first shoulder area 24 and in the second shoulder area 26 are not formed from the same soft rubber material as the corresponding surface areas 30, but are instead formed from another rubber material which, with regard to its stiffness and hardness, lies between the first rubber material I and the second rubber material II on the one hand and the third rubber material III on the other.

[0101] In Fig. Section 7 presents an alternative design of the variant III) discussed above. This corresponds to the basic structure described in Fig. 6 shown structure, however, the inner areas 32 in the first shoulder area 24 and in the second shoulder area 26 are formed by extending the base rubber material B of the base 20 further upwards. Reference symbol list 10 vehicle tires 12 treads 14 profile grooves 16 profile blocks 18 Contact surface 20 Basis 22 Cover layer 24 first shoulder area 26 second shoulder area 28 Central Area 30 surface area 32 Indoor area 34 SR profile blocks 36 Spike 38 NW profile blocks 40 first groove-like depressions 42 second groove-like depressions 44 third groove-like depressions I first rubber material II second rubber material III third rubber material IV fourth rubber material V fifth rubber material VI sixth rubber material B Basic rubber material 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] JPS 6118506 A

[0004] JPS 59124413 A

[0004] RU 2623365 C2

[0004] WO 2015 / 086186 A1

[0006] DE 102022204461 A1 [0010, 0011, 0014, 0016, 0018, 0028, 0039, 0082, 0087] Cited non-patent literature

[0000] DIN 53535:1982-03 [0022, 0059] DIN 53513:1990-03 [0022, 0059]

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