vehicle tires

Abstract

Vehicle tyre in diagonal design with several reinforcement layers (3) arranged one above the other, to which carcass inserts (3b) and optionally breaker layers (3a) or belt layers and / or bead reinforcement strips (5) belong and which each consist of a cord fabric with textile cords (8) embedded in a rubber matrix, wherein the cords (8) are arranged in a cross-pattern in reinforcement layers (3) running adjacent to one another. In the carcass plies (3b) and in the breaker plies (3a), if present, the cords (8) consist of a single multifilament yarn or of two or three multifilament yarns (9) made of polyamide 4.6 which are twisted together at the ends.

Description

The invention relates to a vehicle tyre of diagonal construction having a plurality of reinforcing plies arranged one above the other, which include carcass plies and, if appropriate, breaker plies or belt plies and / or bead reinforcing strips and which each consist of a cord fabric embedded in a rubber matrix and having textile cords, the cords being arranged in a cross-bond in reinforcing plies running adjacent to one another.Such a tire of diagonal design is known, for example, from DE 10 2013 106 632 A1. The cords in mutually adjacently extending reinforcing plies are arranged in a cross-bond with respect to one another in such a way that they extend in the tire crown at an acute angle with respect to the circumferential direction of equal magnitude in all reinforcing plies, which is between 28° and 34° in the case of a tire having a ratio of cross-sectional width to cross-sectional height of 1 and between 26° and 32° in the case of a tire having a ratio of cross-sectional width to cross-sectional height of 0.85. As a result, the bias tires should be more rigid in the circumferential direction than those from the prior art and have a lower rolling resistance. The cords in the reinforcing plies, i.e. the carcass plies and the breaker plies or belt plies, consist, for example, of filaments of aramid, polyamide or polyester. Moreover, it is common in bias tires that the cords in the reinforcement plies consist of multifilament yarns of polyamide 6.6.The invention is based on the object of configuring diagonal tires of the type mentioned at the beginning in such a way that they are particularly well suited for use at higher ambient temperatures or under high load, which is associated with an elevated temperature in the tire, and have a better temperature and heat resistance than the known diagonal tires, in particular the diagonal tires reinforced with polyamide 6.6.The object set is achieved according to the invention in that in the carcass plies and in the breaker plies, if present, the cords consist of a single multifilament yarn or of two or three multifilament yarns of polyamide 4.6 that are end-twisted with one another.Polyamide 4.6 brings about a high rigidity of the reinforcing plies over a wide temperature range, has a high heat resistance and can therefore be used particularly advantageously in reinforcing plies of bias tires as the material of the cords, especially also in tires which are intended to withstand relatively high ambient temperatures permanently or are used under high load. In particular, the modulus loss of polyamide 4.6 at higher temperatures is lower than that of polyamide 6.6, cords of polyamide 4.6 do not relax as much as those of polyamide 6.6. The temperature stability can be quantified in particular on the basis of the temperature-dependent modulus. A material which is more temperature-stable and thus exhibits a lower modulus loss allows the use of thinner and thus lighter cords in the reinforcing plies. This is advantageous for the tire in terms of weight reduction of the tire as a whole and reduction of the tire rolling resistance.For good durability and high performance of the tyre it is further advantageous if the cords in all carcass plies and in the breaker plies optionally present coincide, therefore consist of the same type of polyamide.Advantageously, the cords in the bead reinforcing strips, which are provided depending on the type of tyre, also consist of a multifilament yarn or of a plurality of multifilament yarns of polyamide 4.6.Depending on the type of tire and intended use, different embodiments of the multifilament yarn or of the multifilament yarns are particularly advantageous compared to the yarns made of polyamide 6.6 preferably used hitherto in these types of tires, in particular with regard to the effects mentioned above, such as heat resistance, stiffness of the reinforcing plies, small ply thickness and thus weight reduction and reduction of rolling resistance.Tires for use in two wheels preferably have, for example, multifilament yarns in the reinforcing layers which have 100 dtex to 300 dtex, in particular 200 dtex to 300 dtex, particularly preferably 235 dtex. In vehicle tires for passenger cars and the like, the reinforcing layers preferably contain multifilament yarns with dtex>300 dtex to 700 dtex, in particular 400 dtex to 500 dtex, particularly preferably 470 dtex.Vehicle tires for vehicles which are subject to a higher load, such as commercial vehicle tires, for example, preferably have multifilament yarns with dtex>700 to 1,200 dtex, in particular 800 dtex to 1,100 dtex, particularly preferably 940 dtex, in the reinforcing layers. As an alternative to such vehicles, suitable reinforcing layers are those with multifilament yarns with dtex >1.200 to 1.600 dtex, in particular 1.300 dtex to 1.500 dtex, particularly preferably 1.400 dtex, or multifilament yarns with dtex >1.600 to 2.100 dtex, in particular 1.700 dtex to 2.000 dtex, particularly preferably 1.880 dtex.In vehicle tires of diagonal construction with reinforcement plies which have cords made from a single multifilament yarn, i.e. x1 structures, the multifilament yarns are preferably arranged with 200 epdm to 600 epdm, in particular to 500 epdm, particularly preferably to 450 epdm.In vehicle tires with reinforcement plies with cords made of two or three multifilament yarns end-twisted with one another, the arrangement of the multifilament yarns is preferably carried out with 50 epdm to 300 epdm, in particular to 250 epdm, particularly preferably to 200 epdm.Further features, advantages and details of the invention will now be described in more detail with reference to the schematic drawing which represents exemplary embodiments. Figure shows FIG. 1 is a view of an embodiment of a vehicle tire according to the invention, partially in the cut-away state, with the reinforcing layers exposed, FIGS. 2 and 3 are cross-sections of embodiments of cords.The invention relates to vehicle tires, preferably a pneumatic vehicle tire, of diagonal design (diagonal type), in particular heavy duty tires, industrial tires, OTR tires, passenger car tires and tires for two-wheel vehicles, for example motor bicycles, mopeds and bicycles.Fig. 1 shows an example of a diagonal type vehicle tire comprising a tread 1, sidewalls 2, reinforcing plies 3, which in the embodiment shown include breaker plies 3a, carcass plies 3b and bead reinforcing strips 5, an inner layer 4 and bead regions 6 having bead cores 7.The carcass inserts 3b extend on the inner layer 4 over the circumference of the tyre and between the bead cores 7 and along and within the side walls 2 and the tread 1. The breaker plies 3 aare installed in the tire running radially inside the tread 1 and thus reinforce the tread region. Both the number of carcass plies 3 band the number of breaker plies 3 acan vary in the usual ranges, depending on the type of tire, wherein the tire can also have carcass plies 3 bas reinforcing plies onlyThe breaker plies 3a, the carcass inserts 3b and the bead reinforcing strips 5 each consist of a cord fabric embedded in a rubber matrix and comprising textile cords 8, which will be discussed in more detail below. Both the breaker plies 3 aand the carcass inserts 3 bare installed in the tire in such a way that their cords 8 run alternately in a leftward and rightward manner from ply to ply, so that a stable ply structure with intersecting cords 8 is formed.In the fully vulcanized tyre, the cords 8 in the breaker plies 3a and in the carcass plies 3b in the tyre crown, i.e. at their intersections with the equatorial plane of the tyre, form with the circumferential direction of the tyre angles which are each of the same size and are usually between 20° and 45°, the angles of the cords 8 being of the same size in a specific tyre-except for deviations due to manufacturing tolerances of 2° to 3°. The cords in the bead reinforcing strips 5 extend parallel to each other and to the radial direction of the tyre at an angle of up to 45°.The cords 8 are cords of a single multifilament yarn and of two or three multifilament yarns 9 of polyamide 4.6 (PA 4.6) end-twisted together. FIGS. 2 and 3 show cross sections of cords 8 made of two and of three multifilament yarns 9 end-twisted with one another. As a result of the end twist of the multifilament yarns 9, the respective cord 8 has a circular cross section over its length with a diameter d and in the reinforcing layers 3 in cross section takes up the area of a circle in each case.In Table 1 below, three embodiments of cords 8 according to the invention - Example E1, Example E2 and Example E3, each with corresponding reference examples from the prior art, Example Ref. 1, Example Ref. 2 and Example Ref. 3 -. The cord 8 of examples E1, E2 and E3 replace the respective reference cords of polyamide 6.6 (PA 6.6). In all examples E1, E2 and E3, the cords 8 are cords of two multifilament yarns of PA 4.6 end-twisted together. The cords of the related reference examples Ref. 1, Ref. 2 and Ref. 3 are cords of two multifilament yarns of PA 6.6 end-twisted together.The dtex value, the diameter of the cord, the circular area occupied by the cord, an example of a preferred arrangement in a breaker ply or a carcass insert in epdm (ends per decimeter in the fabric), a value for a preferred mutual clear distance (spacing) of the cords, and also the circular area occupied by the cord multiplied by the epdm, are in each case given in percent, the value of the reference examples being Ref. 1, Ref. 2 and Ref. 3 is set 100% in each case. The embodiment / arrangement of the cords E 1, E 2 and E 3 according to the invention is preferably carried out in such a way that the value of "area x epdm" in % is in each case of the order of magnitude of 75% of the value of the associated reference example. It can be seen that Examples E1, E2, E3 are compared with Reference Examples Ref. 1, Ref. 2 and Ref. This arrangement is also associated with the advantages of a thinner construction of the reinforcing ply and a consequent weight reduction of the tyre. Table 1 Table 1MaterialPA 6.6PA 4.6PA 6.6.PA 4.6PA 6.6PA 4.6Dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex dtex1880 × 21400 × 21400 × 2940 × 2940 × 2470 × 2[%] dtex [%]100%74%100%67%100%50%Diameter [mm]0,80,660,660,530,530,37Area [mm 2]0,50,340,340,220,220,11EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM EPDM105115951105483Spacing0,150,210,390,381,320,83Area× epdm52,839,332,524,311,98,9Area× epdm [%]100751007510075Table 2 shows force strain data, determined according to ASTM D885 (2014), of cords of the construction 470 dtex×2 from PA 4.6 in comparison with cords of the construction 470 dtex×2 from PA 6.6, in each case with respect to the modulus at room temperature (RT), at 80° C., at 100° C. and at 120° C. LASE stands for load at specific elongation, in the present case at 5% strain. Depending on the temperature, a cord made of PA 4.6 has a higher strength by about 20% to 35% than the cord made of PA 6.6. Table 2 Table 2RT15,515,080° C9,511,6100° C8,111,2120° C7,19,5As already mentioned, the cords 8 are cords of one multifilament yarn or of two or three multifilament yarns of PA 4.6 end-twisted with each other. In all cords, only one particular type of yarn is used in each case, wherein Table 3 below reproduces five examples G1, G2, G3, G4 and G5 of multifilament yarns preferably to be used, with associated dtex values, in each case a base region, a preferred region and a single particularly preferred value. Table 3 Table 3Base range [dtex]100-300> 300-700> 700-1200> 1200-1600>1600-2100More preferably, the range [dtex] is200-300400-500800-11001300-15001700-2000particularly preferred value [dtex]23547094014001880Table 4 gives value ranges for the twist factor for cords made from a single multifilament yarn (referred to as "x1 cords") and for cords made from two or three multifilament yarns (referred to as "x2 and x3 cords") made from PA 4.6. In each case a basic value range, a preferred value range and a particularly preferred value range are indicated. Table 4 Table 4x1 cord30-7035-6540-65x2 cord and x3 cord150-250160-240175-225Definition Twist factor: TF = twist level×(dtex / 1000)^0.5 twist level in twist per meterThe rotation of the cords from a single multifilament yarn can be effected in the S or in the Z direction, in the case of cords from two or three multifilament yarns first in the S or in the Z direction, followed by a rotation in the respectively opposite direction.Table 5 gives advantageous ranges for epdm values for cords made from a multifilament yarn (x1 cord) and those made from two or three multifilament yarns (x2 and x3 cords), each made from PA 4.6. Table 5 Table 51x cord200-600200-500200-450x2 cord and x3 cord50-30050-25050-200List of reference characters1 Tread 2 Sidewall 3 Reinforcing ply 3a Breaker ply 3b Carcass ply 4 Inner layer 5 Bead reinforcing strip 6 Bead region 7 Bead core 8 Cords 9 Multifilament yarn d DiameterReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2013 106 632 A1

[0002]

Claims

Vehicle tyre of diagonal construction having a plurality of reinforcing plies (3) arranged one above the other, which comprise carcass plies (3b) and optionally breaker plies (3a) or belt plies and / or bead reinforcing strips (5) and which each consist of a cord fabric with textile cords (8) embedded in a rubber matrix, the cords (8) being arranged in a cross-bond in reinforcing plies (3) running adjacent to one another, characterized in that, in the carcass plies (3b) and in the optionally present breaker plies (3a), the cords (8) consist of a single multifilament yarn or of two or three multifilament yarns (9) of polyamide 4.6 which are twisted end-to-end with one another.Vehicle tyre according to Claim 1, characterized in that the cords (8) in all the carcass plies (3b) and in the breaker plies (3a), which may be present, are designed to match and consist of the same type of yarn.Vehicle tyre according to Claim 1 or 2, characterized in that the cords (8) in bead reinforcing strips (5) likewise consist of a single multifilament yarn or of two or three multifilament yarns (9) of polyamide 4.6.Vehicle tyre according to one of Claims 1 to 3, characterized in that the multifilament yarn or the multifilament yarns (9) has or have 100 dtex to 300 dtex, in particular 200 dtex to 300 dtex, particularly preferably 235 dtex.Vehicle tyre according to one of Claims 1 to 3, characterized in that the multifilament yarn or the multifilament yarns (9) has or have > 300 detx to 700 dtex, in particular 400 dtex to 500 dtex, particularly preferably 470 dtex.Vehicle tyre according to one of Claims 1 to 3, characterized in that the multifilament yarn or the multifilament yarns (9) has or have >700 dtex to 1200 dtex, in particular 800 dtex to 1100 dtex, particularly preferably 940 dtex.Vehicle tyre according to one of Claims 1 to 3, characterized in that the multifilament yarn or the multifilament yarns (9) has or have >1200 dtex to 1600 dtex, in particular 1300 dtex to 1500 dtex, particularly preferably 1400 dtex.Vehicle tyre according to one of Claims 1 to 3, characterized in that the multifilament yarn or the multifilament yarns (9) has or have >1600 dtex to 2100 dtex, in particular 1700 dtex to 2000 dtex, particularly preferably 1880 dtex.Vehicle tyre according to one of Claims 1 to 8, characterized in that the cords (8) consist of a single multifilament yarn (9) and are arranged in the reinforcing plies (3) with 200 epdm to 600 epdm, in particular to 500 epdm, preferably to 450 epdm.Vehicle tyre according to one of Claims 1 to 8, characterized in that the cords (8) consist of two or three multifilament yarns (9) which are end-twisted with one another and are arranged in the reinforcing plies (3) at from 50 epdm to 300 epdm, in particular up to 250 epdm, preferably up to 200 epdm.

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