Vehicle tires

Abstract

Vehicle tires with bead areas, each with a hexagonal bead core (1), and with carcass inserts (2) surrounding the bead cores (1) from the inside of the tire with a ply wrap (2a), wherein each bead core has a cross-section forming a regular hexagon with wire plies (4), comprising two outer wire plies (4a), middle wire plies (4b), and a single central wire ply (4c), which is the widest wire ply, and wherein a radially extending apex (3) is positioned on each bead core (1). The apex (3) opens two lateral lips (6, 7) which laterally encompass the bead core (1) up to the region of the central wire ply (4c) such that the lateral lips (6, 7) occupy the space between the carcass insert (2) and the bead core (1) up to the central wire ply (4c), in particular up to the region lateral to the central wire ply (4c).

Description

The invention relates to a vehicle tyre having bead regions each having a hexagonal bead core and having a carcass ply 2 encircling the bead cores 1 from the inner side of the tyre with a ply turn-over 2a in each case, wherein each bead core has a cross section forming a regular hexagon, having wire plies which include two outer wire plies, central wire plies and a single central wire ply which is the widest wire ply, and wherein an apex extending in the radial direction is positioned on each bead core. The invention further relates to a method for producing a vehicle tire having bead regions each having a hexagonal bead core which has a cross section forming a regular hexagon, wherein the bead cores are joined together to form core packs together with in each case one apex extruded from a rubber mixture and are installed in the green tire.It is customary to install in bead regions of vehicle tires, in particular tires for passenger cars, vans or SUVs, bead cores having a substantially rectangular cross section, which are composed of a plurality of wire layers each having the same number of steel wires. The apex, which provides a good fit of the vehicle tire on a rim and is made of a hard rubber material, is seated on the radially outermost wire layer of the bead core. Such an arrangement is known, for example, from DE 10 2013 109 582 A1. From WO 2022 / 128016 A1 a wire core of a bead ring arrangement is known, which has a substantially polygonal cross section with six corners. The cross-sectional shape is such that the radially outermost wire layer has more steel wires than the radially innermost wire layer, thereby resulting in a flat hexagonal cross-section of the bead core. On the radially outermost layer of the bead core, an apex is positioned.Moreover, vehicle tires of the type mentioned at the beginning with bead cores are known which have a cross section forming a regular hexagon. Tires having bead regions with such bead cores are particularly durable and durable. In tire manufacturing, an apex is usually used, as is used in the case of rectangular bead cores. During the vulcanization of a vehicle tire manufactured with such bead regions, air inclusions repeatedly occur laterally of the bead core between the carcass insert encircling the bead core and the bead core, since the rubber material of the apex does not have the flowability in order to adapt to the bead core.The object of the invention is thus to provide a vehicle tire and a method of the type mentioned at the beginning, in which air inclusions of this type no longer occur.With regard to the vehicle tire, the object set is achieved according to the invention in that the apex has two lateral lips which laterally surround the bead core as far as into the region of the central wire layer in such a way that the lateral lips assume the intermediate space between the carcass ply and the bead core as far as the central wire layer, in particular as far as into the region laterally of the central wire layer.As regards the method, the object set is achieved according to the invention in that the apex is extruded with a main section and two lateral lips which laterally surround the bead core in the core package, reaching as far as the widest point thereof.According to the invention, an apex is provided and installed in the bead regions, which apex is provided with lateral lips which surround the bead core in such a way that air inclusions can no longer be produced.Preferably, the apex is obtained from a rubber mixture by extrusion with co-molding of the two lips. This ensures that the apex is designed in such a way that its dimensions are well matched to the interstices between the carcass insert and the bead core.In a preferred embodiment, the lip located on the tire inner side has a width at the level of the outer side of the radially outermost wire layer of the bead core which is 1.00 mm to 2.00 mm and is smaller by at least 0.50 mm than the width of the lip located on the tire outer side at the level of the outer side of the radially outermost wire layer, wherein this width is preferably 2.00 mm to 2.50 mm. As a result, the interstices between the carcass insert and the apex, which are of different widths due to the design, are taken into account in order to particularly effectively prevent the formation of air inclusions during the vulcanization of the tire.The apex is preferably made of a rubber material whose Shore A hardness according to DIN ISO 7619-1 is 42 to 60, in particular 50 to 55. The apex therefore has, together with its two lips, a rigidity and stability which is advantageous for the high loads in the bead regions.Preferably, the bead cores in the bead regions each have five wire layers, wherein the outermost wire layers each have three steel wires, the two middle four steel wires in each case and the central wire layer five steel wires.In the method according to the invention, the apex is preferably extruded such that the lip on the main portion provided on the inner side of the tire has a width which is 1.00 mm to 2.00 mm and is smaller by at least 0.50 mm than the width of the lip on the main portion located on the outer side of the tire, the latter preferably being 2.00 mm to 2.50 mm. Furthermore, the apex is advantageously extruded such that the widths of the lips continuously decrease up to their ends.Further features, advantages and details of the invention will now be described in more detail with reference to the schematic drawing which represents an exemplary embodiment. Figure shows FIG. 1 is a cross-sectional view of a bead portion of a vehicle tire; and FIG. 2 shows the detail D of FIG. 1 in an enlarged illustration.Vehicle tires according to the invention are tires for motor vehicles, in particular for multi-lane motor vehicles, preferably passenger cars (passenger cars), vans (transporters) or SUV, and pneumatic vehicle tires, particularly preferably pneumatic vehicle tires of radial design. CAR, van and SUV tires are provided in particular for rims with an integral rim diameter of 13 inches to 24 inches, preferably of 15 inches to 23 inches, and have a load bearing index of in particular 71 to 126.FIG. 1 shows a cross section of the one bead region of a vehicle tire, wherein the second bead region is of identical construction. Of the components present in the bead region of the vehicle tire, a bead core 1, a carcass insert 2 encircling the bead core 1 from the inner side of the tire with its ply turn-over 2 a,for example a fabric ply, and an apex 3 are illustrated in FIG. 1. The carcass insert 2 runs on the inside and on the outside of the tire along and in contact with the apex 3 and ends with its ply turn-over 2 aextending along the apex 3 in a known manner radially outside the apex 3. The bead portion further includes a bead seat surface 8 with which the tire is seated on a rim.As shown in particular in FIG. 2, the bead core 1 is a hexagonal core with a cross section forming a regular hexagon. The bead core 1 is composed of five parallel wire layers 4, two outer wire layers 4a each of three rubberized steel wires 5, two adjacent middle wire layers 4b each of four rubberized steel wires 5, and one central wire layer 4c each of six rubberized steel wires 5.Apex 3 is made of a rubber material having a Shore A hardness according to DIN ISO 7619-1 of 42 to 60, in particular 50 to 55, and has a main section 3 alocated radially outside radially outermost wire layer 4 a, as well as a lip 6 on the tire inner side and a lip 7 on the tire outer side. The lips 6 and 7 respectively extend in contact with the inside of the carcass ply 2 and the outside of the bead core 1 to the central wire layer 4c, more specifically to the center of the central wire layer 4c.The tire inner-side lip 6 has, at the level of the outer side of the radially outermost wire layer 4 aand determined as an extension of the outer side, a width b 1 which is 1.00 mm to 2.00 mm and is smaller by at least 0.50 mm than the width b 2 of the opposite tire outer-side lip 7, wherein the width b 2 of the lip 7 is 2.00 mm to 2.50 mm. In the direction of their narrowest points in the region at or next to the central wire layer 4c, the width of the lips 6, 7 decreases continuously, so that the lips 6, 7 finally no longer have a width.Apex 3 is prepared by extruding a conventional apex rubber composition having the above-mentioned hardness when vulcanized. In this case, the apex with the two lateral lips 6 and 7 having different widths is extruded as described.List of reference characters1 Bead portion 2 Carcass ply 2a Ply turnup 3 Apex 4 Wire ply 4a Outer wire ply 4b Middle wire ply 4c Central wire ply 4c Central wire ply 5 Steel wire 6, 7 Lip 8 Bead seat surface b 1, b 2 WidthReferences 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 109 582 A1

[0002] WO 2022 / 128016 A1

[0002]

Claims

Vehicle tyre having bead regions each having a hexagonal bead core (1) and having a carcass ply (2) which extends circumferentially from the inner side of the tyre with a ply turn-over (2a) in each case, wherein each bead core has a cross section which forms a regular hexagon and has wire plies (4) which include two outer wire plies (4a), central wire plies (4b) and a single central wire ply (4c) which is the widest wire ply, and wherein an apex (3) which extends in the radial direction is positioned on each bead core (1), characterized in that the apex (3) has two lateral lips (6, 7) which laterally surround the bead core (1) as far as into the region of the central wire ply (4c) in such a way that the lateral lips (6, are positioned on each bead core (1), 7) can take up the space between the carcass ply (2) and the bead core (1) up to the central wire layer (4c), in particular up to the region to the side of the central wire layer (4c).Vehicle tyre according to Claim 1, characterized in that the apex (3) is obtained from a rubber mixture by extrusion, with the two lips (6, 7) being concomitantly formed.Vehicle tyre according to Claim 1 or 2, characterized in that the lip (6) on the inside of the tyre has a width (b 1) at the level of the outer side of the radially outermost wire ply (4a), which width is 1.00 mm to 2.00 mm and is smaller by at least 0.50 mm than the width (b 2) of the lip (7) on the outside of the radially outermost wire ply (4a).Vehicle tyre according to one of Claims 1 to 3, characterized in that the width (b 2) of the lip (7) located on the tyre outer side at the level of the outer side of the radially outermost wire layer (4a) is 2.00 mm to 2.50 mm.Vehicle tyre according to one of Claims 1 to 4, characterized in that the widths (b 1, b 2) of the lips (6, 7) decrease continuously as far as into the region of the central wire layer (4c).Vehicle tyre according to one of Claims 1 to 5, characterized in that the apex (3) consists of a rubber material, the Shore A hardness of which according to DIN ISO 7619-1 is from 42 to 60, in particular from 50 to 55.Vehicle tyre according to one of Claims 1 to 6, characterized in that the bead core (1) has five wire layers (4), the two outer steel wires (5) each having three, the two middle steel wires (5) each having four and the central five steel wires (5).Method for producing a vehicle tyre having bead regions each having a hexagonal bead core (1) which has a cross section forming a regular hexagon, wherein the bead cores (1) are joined together to form core packs together with in each case one apex (3) extruded from a rubber mixture and are installed in the green tyre, characterized in that the apex (3) is extruded with a main portion (3a) and two lateral lips (6, 7) which laterally surround the bead core (1) in the core pack as far as the widest point thereof.Method according to claim 8, characterised in that the apex (3) is extruded in such a way that the lip (6) on the main section (3a) provided on the inside of the tyre has a width (b 1) which is 1.00 mm to 2.00 mm and is smaller by at least 0.50 mm than the width (b 2) of the lip (7) on the main section (3a) located on the outside of the tyre.Method according to claim 8 or 9, characterised in that the apex (3) is extruded in such a way that the width (b 2) of the lip (7) provided on the outside of the tyre at the main portion (3a) is 2.00 mm to 2.50 mm.Method according to any one of claims 8 to 10, characterised in that the apex (3) is extruded in such a way that the widths (b 1, b 2) of the lips (6, 7) decrease continuously as far as their ends.

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