Method for manufacturing a vehicle tyre

Abstract

The invention relates to a method for manufacturing a vehicle tyre having an inner liner, a carcass ply, a bead core (4), a tyre belt and a tread, the method comprising the following steps: a) loading an apparatus (1) with the carcass (8), or building the carcass (8) on the apparatus (1), wherein the carcass (8) comprises the inner liner, carcass plies and the bead cores (4), wherein the bead cores (4) are clamped in clamping heads (3); b) pneumatically shaping the carcass ply on the clamping heads (3); c) expanding the integrated belt-building drum (2); d) laying the belt ply onto the contour defined by the belt-building drum (2); and e) completing the vehicle tyre in further steps.

Description

[0001] 202407917

[0002] 1

[0003] Description

[0004] Method for manufacturing a vehicle tire

[0005] The invention relates to a

[0006] Method for manufacturing a vehicle tire comprising an inner layer, a carcass layer, a bead core, a tire belt and a tread, comprising the following steps:

[0007] a) Loading a device with the carcass or producing the carcass on the device, wherein the carcass comprises the inner layer, carcass plies and the bead cores, wherein the bead cores are clamped in clamping heads, b) pneumatically crowning the carcass ply on the clamping heads,

[0008] c) Expansion of the integrated belt drum,

[0009] d) Placing the belt layer onto the geometry provided by the belt construction drum,

[0010] e) Completing the vehicle tire with further steps.

[0011] Furthermore, the invention relates to a device and a vehicle tire.

[0012] Known methods for manufacturing vehicle tires, particularly motorcycle tires, involve winding a tire carcass onto a first machine. The assembled carcass is then transferred to a second machine. On this second machine, steel cords are wound circumferentially to create the belt plies. The resulting belt bundle is then transferred to the tire carcass and bonded to it.

[0013] To prevent the belt pack from being affected by the transfer process, a transfer layer is wound onto the construction drum before the steel cords are wound on. This transfer layer incurs additional costs in the manufacturing process due to material and processing costs and negatively impacts the tire's properties, for example, by increasing weight and rolling resistance. 202407917

[0014] 2

[0015] Furthermore, inaccuracies in the structure of the belt layers are caused by the transfer.

[0016] Against this background, the invention is based on the objective of designing a method, a device and a vehicle tire in such a way that a weight- and rolling resistance-optimized vehicle tire with particularly high accuracy of the positions of the belt layers can be manufactured in a particularly cost-effective and resource-saving manner.

[0017] This problem is solved by a method according to the features of claim 1, as well as by a device and a vehicle tire according to the dependent claims. The subclaims relate to particularly advantageous embodiments of the invention.

[0018] According to the invention, a method for manufacturing a vehicle tire with an inner layer, a carcass layer, a bead core, a tire belt and a tread is provided, comprising the following steps:

[0019] a) Loading a device with the carcass or producing the carcass on the device, wherein the carcass comprises the inner layer, carcass plies and the bead cores, wherein the bead cores are clamped in clamping heads, b) pneumatically crowning the carcass ply on the clamping heads,

[0020] c) Expanding the integrated belt construction drum, wherein the contour of the carcass is defined by the belt construction drum before the belt ply is applied, d) Applying the belt ply to the geometry defined by the belt construction drum,

[0021] e) Completing the vehicle tire with further steps.

[0022] Pneumatic crowning of the carcass plies on the clamping heads achieves uniform expansion of the carcass plies. In particular, excessive expansion of the carcass plies in certain areas, as caused by mechanical expansion, is avoided. Sufficiently precise placement of the belt plies on this pneumatically expanded carcass ply is not possible due to the flexibility of the carcass plies. The integrated belt construction drum is expanded to such an extent that the carcass contour is defined by the 202407917

[0023] 3

[0024] The belt construction drum is specified. Sufficiently accurate placement of the belt layers on this rigid geometry is possible.

[0025] Transferring the belt bundle to the carcass layer is unnecessary, as the belt layers are already wound onto the carcass layer to form the belt bundle. Therefore, placing a transfer layer is also unnecessary.

[0026] A preferred embodiment provides that step c) follows step b), wherein in step c) the circumference of the carcass ply is increased by no more than 5%, preferably by no more than 3%, and more preferably by no more than 1%. The sequence that step c) follows step b) means, in particular, that the carcass ply is first enlarged in circumference by crowning and subsequently by expanding the integrated belt construction drum. Expansion of the integrated belt construction drum during the crowning process should not be excluded. The expansion of the integrated belt construction drum has a particularly small negative impact on the positioning of the belt plies if the circumference of the carcass ply is increased as little as possible by the expansion.

[0027] Another preferred embodiment provides that in step b) the internal overpressure is set to 0.1 bar to 5 bar, preferably 0.3 bar to 3 bar, and more preferably 0.5 bar to 1.5 bar. Setting these preferred internal overpressures achieves sufficient, but not excessive, expansion of the carcass layers.

[0028] Another preferred embodiment provides that the internal overpressure is reduced after step c). Reducing the internal overpressure allows the carcass plies to be laid down onto the expanded belt drum. It has been shown that this allows the elongations of the carcass plies to be more uniform. This leads to a more precise positioning of the belt plies relative to the carcass plies.

[0029] Another preferred embodiment provides that steps b) and c) are carried out with a temporal overlap, preferably the pneumatic crowning and the expanding belt construction drum for the 202407917

[0030] 4

[0031] This process contributes to increasing and / or reducing the diameter of the vehicle tire under construction. It has been shown that combining pneumatic and mechanical stretching of the carcass layers allows for a preferential distribution of elongation within the carcass layers.

[0032] Another preferred embodiment provides that, before removing the vehicle tire being assembled from the device, the belt assembly drum is reduced to an outer diameter that is smaller than the core diameter of the vehicle tire being assembled.

[0033] Another preferred embodiment provides that the vehicle tire under construction is removed from the device before a tread strip is applied or wound onto it and fed to another tire manufacturing machine.

[0034] According to the invention, a device for manufacturing a vehicle tire, in particular a motorcycle tire, is provided comprising an expandable belt construction drum and clamping heads arranged on both sides in the axial direction of the belt construction drum for fixing bead cores, wherein the device has sealing sleeves for pneumatically sealing the clamping heads to vehicle tire parts, in particular the carcass, wherein the device is sealed to its environment in such a way that the vehicle tire in the assembly can be pressurized with an internal overpressure.

[0035] The pneumatic sealing of the clamping heads to the vehicle tire components enables the pneumatic crowning of the carcass layers on the clamping heads. Uniform expansion of the carcass layers is achieved.

[0036] In particular, excessive stretching of the carcass plies in certain areas, as caused by mechanical stretching, is avoided. Sufficiently precise placement of the belt plies on this pneumatically stretched carcass ply is not possible due to the flexibility of the carcass plies. The integrated belt builder drum is expanded to such an extent that the carcass contour is defined by the belt builder drum. (Ein202407917)

[0037] 5

[0038] Sufficiently accurate placement of the belt layers on this unyielding geometry is possible.

[0039] A preferred embodiment provides that the device is configured for laying down and / or winding up a tread strip. This eliminates the need for transferring the tire to another construction machine and also eliminates the need for an additional construction machine. Winding up the tread strip is also known as stripwinding. It has been shown that vehicle tires manufactured in this way reliably meet particularly high geometric requirements, such as tire concentricity.

[0040] Another preferred embodiment provides that the sealing sleeve comprises, and preferably consists of, a silicone or vulcanized rubber. Silicone and rubber have proven suitable materials for sealing and with regard to their wear resistance.

[0041] Another preferred embodiment provides that the tread is pressed against a round blank contour extending from bead to bead by means of an inflating bellows mounted in a belt support ring, thereby enabling a wrinkle-free reduction in the tread diameter. This method of transporting the vehicle tire under construction, also called a tire blank, results in a particularly low negative impact on the geometry of the vehicle tire.

[0042] Another preferred embodiment provides that the device is configured to carry out a method according to the invention.

[0043] According to the invention, a vehicle tire is manufactured using a method according to the invention and preferably using a device according to the invention. Such a vehicle tire can be manufactured with particularly low reject rates, even with particularly high geometric requirements, and exhibits particularly high quality, for example, with regard to its concentricity. 202407917

[0044] 6

[0045] The invention allows for numerous embodiments. To further illustrate its basic principle, one of these is shown in the drawings and described below. This shows in

[0046] Fig. 1 shows a device for manufacturing a vehicle tire in its compressed state.

[0047] Fig. 2 the device for manufacturing a vehicle tire in a partially expanded state,

[0048] Fig. 3 shows the device for manufacturing a vehicle tire in the expanded state.

[0049] Figure 1 shows a device 1 for manufacturing a vehicle tire in the form of a motorcycle tire with an expandable belt drum 2. Clamping heads 3 for fixing bead cores 4 are arranged axially on both sides of the belt drum 2. The clamping heads 3 are moved towards or apart from each other by means of a threaded spindle 5, whereby the belt drum 2 is also expanded or collapsed by means of pressure rods 6.

[0050] The device 1 has silicone sealing sleeves 7 for pneumatically sealing the clamping heads 3 to the carcass 8. The device 1 as a whole is sealed from its surroundings in such a way that the motorcycle tire under construction can be pressurized internally and thus brought into the required geometry. In Figure 1, the internal pressure corresponds to the ambient pressure. The belt construction drum 2 is not in contact with the carcass 8.

[0051] Figure 2 shows the device 1 in a partially expanded state. The motorcycle tire being assembled has expanded radially outwards due to the internal overpressure in the device 1. The device 1 is expanded in the axial direction.

[0052] 7

[0053] A is compressed and the belt drum 2 is in a partially expanded state and does not touch the motorcycle tire.

[0054] Figure 3 shows the device 1 in an expanded state. Due to the internal overpressure and the axial contraction of the device 1, the motorcycle tire has assumed a contour suitable for belt application. By reducing the internal overpressure, the carcass 8 comes into contact with the belt building drum 2 and is mechanically supported by it for belt application. The sealing sleeves 7 are in sealing contact with the carcass 8.

[0055] The belt layer is placed on top, whereupon the belt construction drum 2 collapses and the internal overpressure is released. The motorcycle tire is removed. 202407917

[0056] 8

[0057] Reference symbol list

[0058] 1 Device

[0059] 2 Belt drum 3 Tensioning head

[0060] 4 bead core

[0061] 5 threaded spindle

[0062] 6 pressure rod

[0063] 7 Sealing sleeve 8 Carcass

[0064] A Axial direction

Claims

202407917 9 Patent claims 1. Method for manufacturing a vehicle tire comprising an inner layer, a carcass layer, a bead core (4), a tire belt and a tread, comprising the following steps: a) Loading a device (1) with the carcass (8) or producing the carcass (8) on the device (1), wherein the carcass (8) comprises the inner layer, carcass plies and the bead cores (4), wherein the bead cores (4) are clamped in clamping heads (3), b) pneumatic crowning of the carcass layer on the clamping heads (3), c) expansion of the integrated belt construction drum (2), d) Placing the belt layer onto the geometry given by the belt construction drum (2), e) Completing the vehicle tire with further steps.

2. Method according to claim 1, characterized in that Step c) follows step b), wherein in step c) the extent of the carcass layer is increased by no more than 5%, preferably by no more than 3%, and more preferably by no more than 1%.

3. Method according to claims 1 or 2, characterized in that in step b) the internal overpressure is set to 0.1 bar to 5 bar, preferably 0.3 bar to 3 bar and more preferably to 0.5 bar to 1.5 bar.

4. Method according to one of the preceding claims, characterized in that after step c) the internal overpressure is reduced.

5. A method according to one of the preceding claims, characterized in that steps b) and c) are carried out with a temporal overlap, wherein preferably the pneumatic crowning and the expanding belt construction drum (2) contribute to increasing and / or reducing the diameter of the vehicle tire under construction. 10 6. Method according to one of the preceding claims, characterized in that, before removing the vehicle tire being assembled from the device, the belt assembly drum (2) is reduced to an outer diameter that is smaller than the core diameter of the vehicle tire being assembled.

7. Method according to one of the preceding claims, characterized in that the vehicle tire being assembled is removed from the device (1) before a tread strip is applied or wound onto it and is fed to another tire building machine.

8. Device for manufacturing a vehicle tire, in particular a motorcycle tire, comprising an expandable belt construction drum (2) and clamping heads (3) arranged on both sides in the axial direction of the belt construction drum (2) for fixing bead cores (4), characterized by the fact that the device (1) has sealing sleeves (7) for pneumatically sealing the clamping heads (3) to vehicle tire parts, in particular the carcass (8), wherein the device (1) is sealed to its surroundings in such a way that the vehicle tire in the assembly can be pressurized with an internal overpressure.

9. Device according to claim 8, characterized in that the device (1) is set up for laying a running strip and / or for winding up a running strip.

10. Device according to claim 8 or 9, characterized in that the sealing sleeve (7) comprises a silicone or a vulcanized rubber and preferably consists of a silicone or a vulcanized rubber.

11. Device according to one of claims 8 to 10, characterized in that the tread strip is pressed against a round blank contour extending from bead to bead by means of a bellows mounted in a belt support ring, thereby enabling a wrinkle-free diameter reduction of the tread strip. 202407917 11 12. Device according to one of the preceding claims, characterized in that the device (1) is configured to carry out a method according to any one of claims 1 to 7.

13. Vehicle tires manufactured by a method according to one of claims 1 to 7 and preferably manufactured with a device (1) according to one of claims 8

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