Method for manufacturing a vehicle tire

Abstract

Method for manufacturing a vehicle tire (1), comprising at least the following steps: a) providing or manufacturing a tire blank, comprising at least: a tire carcass, two sidewalls (2), tire beads, a tire belt (3) and a winding band with one or more tire assembly drums, b) providing a first printing device (5a) for applying a rubber material (6a) to form a tread (4), c) providing a second printing device (5b) for applying a ply material (6b) to match the tread (4), d) manufacturing a tread (4) by d1) applying the first printing device (5a) layer by layer (8.i) applies the rubber material (6a) of the tread (4) at predefined first positions (P1), and d2) the second printing device (5b) applies the insert material (6b) selectively at predefined second positions (P2) such that the insert material (6b) is locally embedded in the rubber material (6a) in the finished tread (4) to form application-specific local insert areas (7; 7a, 7b, 7c, 7d, 7e, 7f) in the tread (4), wherein the rubber material (6a) and the insert material (6b) form a tread (4) with a tire profile with multiple tread blocks layer by layer (8.i), e) curing the tread (4), and f) completing the vehicle tire (1) with further steps.

Description

The invention relates to a method for manufacturing a vehicle tire. To manufacture a vehicle tire, a tire blank is first provided, consisting of a tire carcass, sidewalls, tire beads, a multi-ply tire belt, and a spool band. The tread with the tire profile is then produced by extruding a strip with a corresponding cross-sectional area and bonding it to the tire blank, particularly to the tire belt. For this purpose, a rubber compound tailored to the vehicle tire is extruded into a tread and then applied to the tire blank. DE 10 2015 210 579 A1, DE 10 2015 210 580 A1, DE 10 2006 038 742 A1, DE 10 2005 061 092 A1, and DE 10 2006 032 817 A1 disclose known methods for manufacturing vehicle tires. The disadvantage here is that the tire performance of the vehicle tire, which is determined by the tread, can only be adjusted to a limited extent, since the entire tread consists of only one material. It is therefore an object of the invention to provide a method that allows for improved, application-specific production of a vehicle tire with low manufacturing costs. This problem is solved by a method according to claim 1. Advantageous embodiments are specified in the dependent claims. According to the invention, the following steps are to be carried out in a method: a) providing or manufacturing a tire blank, comprising at least: a tire carcass, two sidewalls, tire beads, a tire belt and a winding band with one or more tire assembly drums, b) providing a first printing device for applying a rubber material to form a tread, c) providing a second printing device for applying a reinforcement material to customize the tread, d) manufacturing a tread by d1) the first printing device applying the rubber material of the tread layer by layer at predefined first positions, and d2) the second printing device selectively applying the reinforcement material at predefined second positions such that the reinforcement material is locally embedded in the rubber material in the finished tread to form application-specific profiles.local insert areas in the tread, wherein a tread with a tire profile with multiple tread blocks is formed layer by layer by the rubber material and the insert material, e) curing of the tread, and f) finishing of the vehicle tire with further steps. By using printing devices, preferably those based on 3D technology that enable an additive printing process, a tread pattern defined in advance via a 3D model can advantageously be formed. An additional process for shaping the tire profile, such as a molding process, can be eliminated, as the tire profile with its tread blocks is already produced by the printing devices. Furthermore, producing the tread pattern using an additive printing process results in less manufacturing waste. Manufacturing effort and costs are reduced. This makes the production of prototypes particularly cost-effective. Furthermore, the insert areas can be locally formed with special properties by the printing devices without any further processing steps. These properties improve tire performance or enable the transmission of electrical signals or heat dissipation. The manufacturing process allows the insert material to be applied layer by layer within the same layer as the rubber material of the tread. This reduces production time, as both printing devices can operate in parallel or sequentially within the same layer. In this context, "local" means that the reinforcing material is applied specifically within one or more profile blocks of the tread, so that the finished tread does not have a continuous reinforcing area around its entire circumference. Thus, the tread is only given a specific property at those local points where the respective property is absolutely necessary and does not impede performance. This saves on reinforcing material and allows for the production of a tread optimally suited to the application. According to an advantageous embodiment, more than two printing devices can be provided, allowing more than two different materials to be applied to the tread. This increases variability, as it enables finer adjustment of the tread pattern. The process begins with a first layer or level, which, for example, lies directly on the tire blank. The tread can be manufactured layer by layer directly on the tire blank, or it can be pre-fabricated layer by layer and then applied to the tire blank. Depending on the planned design and structure of the tread blocks, the first layer or level consists of a specific area of ​​rubber material with the insert material and, if necessary, additional insert materials in between. The tread is then successively built up layer by layer with the insert material and / or the rubber material. For this, the pre-defined 3D model of the tread is reproduced using at least two printing devices in an additive manufacturing process, with individual layers or levels also consisting solely of rubber material. Thus, a layered construction of the tread means that the first and second printing devices essentially operate in the same layer and complete it before starting a new layer, so that the individual layers are successively built up by both printing devices, with some layers even consisting solely of rubber material. This can be deviated from, for example, during the transition to a subsequent layer, by having one of the printing devices move on to the next layer while the other printing device completes the preceding layer. The tread can be produced by the printing devices applying a single profile block layer by layer and then continuing layer by layer with the next profile block, or by building up the entire tread with all profile blocks layer by layer. According to one embodiment, 3D printing devices utilize extruders that apply the respective material, in its unvulcanized form (e.g., viscoelastic material), to a surface via an extruder opening. One extruder is provided for the rubber material (in its unvulcanized form), and another for the ply material (also in its unvulcanized form). The respective extruder openings are designed to allow for very thin application of the rubber or ply material at the relevant locations, enabling a highly detailed structure of the tread, including the tire profile and ply areas. The printing device is controlled layer by layer, allowing the tread to be additively built up with the respective material using two or more extruders. According to an alternative embodiment, printing devices based on powder solidification are used. In this embodiment, the first printing device applies the rubber material, in particular a photosensitive polymer, in powder form to a surface and solidifies it at the first positions using a low-energy light source, for example, UV light or an electron beam. The molecules of the rubber material form a bridge bond upon treatment with the light source. The second printing device applies the insert material, which is also in photosensitive form, and then solidifies it at the second positions using the same low-energy light source. To form multiple materials within a single layer, the rubber material is selectively solidified, and the unsolidified rubber powder is removed.The insert material in powder form is then applied, particularly to the recessed areas of the layer, and solidified at the corresponding second positions, so that there are two solidified materials within one layer. Within the scope of the invention, the application of the rubber material or the application of the insert material by the respective printing device is understood to be a single-stage (non-vulcanized material) or a multi-stage process (powder solidification), in which the provided material is applied layer by layer to a surface using the respective printing device. The printing devices can also be designed with multiple parts, for example, a part that applies the powder and another part (low-energy light source) that solidifies the powder to obtain the final rubber material or insert material. Other 3D technologies based on "additive manufacturing" can also be considered and combined in any way to create a variable layer structure. According to an advantageous embodiment, this allows, for example, horizontal and / or vertical and / or inclined or beveled structures to be created in the insert areas of the tread by moving the printing devices to the corresponding positions during the tread manufacturing process, where the rubber material or the insert material is applied to replicate the 3D model. Complex structures can also be created by combining the aforementioned structures. This advantageously allows for the simple integration of variable-shaped structures into the tread, for which one or more application-specific insert materials can be selected. This enables, for example, better adaptation of tire performance to the specific application; that is, grip, rolling resistance, tire wear, impact resistance, or handling characteristics can be more precisely adjusted depending on environmental conditions such as road surface or temperature.This can be achieved by using insert materials with a specific property at the corresponding predefined positions in the tread, so that one or more insert areas are formed in the tread in which the at least one insert material interacts with the rubber material in such a way that the tread exhibits a specific behavior during operation of the vehicle tire. According to an advantageous embodiment, the hardness of the at least one insert material can be adjusted. By using a softer insert material inside the rubber material in an area of ​​the tread where higher pressure is exerted, for example, the grip, especially on wet and icy roads, or the wear of the vehicle tire can be improved, since the pressure acting on the vehicle tire is reduced. Using a hard insole material allows for the creation of harder areas in the tread, which also improves grip on ice and snow, as the tread can better engage with the ice or snow. Therefore, a combined application of hard and soft insole materials in specific areas of the tread can optimize grip. Furthermore, according to another embodiment, insert materials can be used that are crack-resistant and therefore less susceptible to cracks or breaks. For example, materials with less filler can be used, which are softer and therefore prevent unwanted cracks, such as those that may occur in the area of ​​a lamella, from propagating in the tread strips. According to an advantageous embodiment, conductive materials, such as metallic materials, can also be used as insert materials. These can serve as leads for a sensor in the vehicle tire or in the tread, enabling the transmission of signals received by the sensor or the supply of energy to the sensor. Alternatively, thermally conductive materials can be used to improve the dissipation of generated heat. According to an advantageous further development, the insert material can act as a shield, thus increasing the service life of individual, for example heavily stressed, areas of the tread. According to an advantageous further development, the insert material can have different colors to enable the identification of the vehicle tire. For this purpose, areas with different contrast can be formed by the insert material and the rubber material, for example in the form of a barcode or a QR code, so that the resulting marking can be read by a reading device and the tread can thus be identified. According to an advantageous embodiment, the ply material can also be designed with small recesses or cavities. These serve to suppress the noise generated during the operation of the vehicle tire. For this purpose, the cavities can be formed in pre-identified areas of the tread that are particularly sensitive to noise during operation. To create cavities in the ply material, a material is used that automatically forms cavities through an additional heat treatment, resulting in a foam-like structure within the ply area. The ply material can be chemically treated in the relevant area so that, upon heating, for example during the final vulcanization process, it forms foam-like structured cavities inside. After the tread is manufactured, at least the tread is made resistant in a curing process, for example in a vulcanization device, and then further usual process steps are carried out to complete the vehicle tire. The invention will be explained in more detail below using exemplary embodiments. Figures 1a and 1b show a vehicle tire during the production of a tread according to a first and a second embodiment; and Figures 2a-f show insert areas of different shapes in the tread according to Figures 1a and 1b. As shown in Fig. 1a, a vehicle tire 1 with sidewalls 2 is provided, on whose tire belt 3 a tread 4 is produced. For this purpose, two printing devices 5a, 5b, designed as extruders, are provided, wherein a first printing device 5a supplies a non-vulcanized rubber material 6a via a first extruder opening 5c ​​and a second printing device 5b supplies a non-vulcanized insert material 6b via a second extruder opening 5d. The printing devices 5a, 5b are moved to predefined positions P1, P2 above the tire belt 3 and the rubber material 6a is applied layer by layer at a first position P1 and the insert material 6b at a second position P2, respectively, by extruding the non-vulcanized material 6a, 6b from the extruder openings 5c, 5d, so that the tread 4 with a tire profile (not shown) with several tread blocks is produced in an additive printing process. Simultaneously, several local insert areas 7 are formed in the tread 4, in which both the insert material 6b and the rubber material 6a are applied, with the insert material 6b being embedded in the rubber material 6a. Through the interaction of the insert material 6b and the rubber material 6a, a specific driving behavior is achieved in these insert areas 7 of the finished vehicle tire 1. Additionally or alternatively, the insert material 6b can also serve as a conductive material to transmit signals from sensors or to supply energy to the sensors. According to a further embodiment shown in Fig. 1b, printing devices 5a, 5b are provided with which a powder layer 9a, 9b of powdered rubber material 6ap or powdered infill material 6bp is first applied in any desired manner to apply the rubber material 6a and the infill material 6b, respectively. The application of the powder layers 9a, 9b can be carried out in any desired manner. This is only indicated schematically in Fig. 1b. Subsequently, the respective powder layer 9a, 9b is treated at the predefined positions P1, P2 with a light source 10 belonging to the printing device 5a, 5b such that molecules of the powder 9a, 9b form a bridge bond, thereby forming the solidified rubber material 6a or the solidified infill material 6b. In this way, layer by layer is built up successively to form an infill area 7 made of different materials. As an example, insert areas 7, produced using one of the aforementioned additive manufacturing processes or a combination thereof, are shown in Figures 2a to 2f. According to Figure 2a, a first insert area 7a is formed by embedding the insert material 6b horizontally, with respect to the tread 4, into the rubber material 6a. For this purpose, only the rubber material 6a is initially applied in a first layer 8.1. In a second layer 8.2, a portion of the rubber material 6a and, horizontally, the insert material 6b are then applied. In the third and all subsequent layers 8.3, ..., 8.6, only the rubber material 6a is applied. A second insert area 7b, as shown in Fig. 2b, has vertical or radial structures made of the insert material 6b extending towards the vehicle tire 1, which are manufactured analogously to the first insert area 7a. In a further embodiment according to Fig. 2c, beveled structures made of the insert material 6b are provided in a third insert area 7c. According to Figs. 2d and 2e, complex structures made of the insert material 6b are provided as a fourth insert area 7d and a fifth insert area 7e, wherein the complex structures represent a combination of horizontal (7a), vertical (7b), and beveled structures (7c). According to Fig. 2f, a sixth insert area 7f contains an insert material 6b with cavities 11, the cavities being formed after heat treatment of the applied insert material 6b, resulting in a sponge-like structure that can suppress noise. After the tread 4 has been completed with one or more of the insert areas 7a to 7e, the tread 4 is cured, for example, on the tire blank in a vulcanization process and the vehicle tire 1 is completed in further steps. Reference symbol list 1 Vehicle tire 2 Sidewalls 3 Tire belt 4 Tread 5a First printing device 5b Second printing device 5c First extruder opening 5d Second extruder opening 6a Rubber material 6ap Powdered rubber material 6b Insert material 6bp Powdered insert material 7 Insert area 7a First insert area 7b Second insert area 7c Third insert area 7d Fourth insert area 7e Fifth insert area 8.i Layers of the tread 9a, 9b Powder layer 10 Light source 11 Cavities P1, P2 First, Second position

Claims

Method for manufacturing a vehicle tire (1), comprising at least the following steps: a) providing or manufacturing a tire blank, comprising at least: a tire carcass, two sidewalls (2), tire beads, a tire belt (3) and a winding band with one or more tire assembly drums, b) providing a first printing device (5a) for applying a rubber material (6a) to form a tread (4), c) providing a second printing device (5b) for applying a reinforcement material (6b) to match the tread (4), d) manufacturing a tread (4) by d1) applying the first printing device (5a) layer by layer (8.i) applies the rubber material (6a) of the tread (4) at predefined first positions (P1), and d2) the second printing device (5b) applies the insert material (6b) selectively at predefined second positions (P2) such that the insert material (6b) is locally embedded in the rubber material (6a) in the finished tread (4) to form application-specific local insert areas (7; 7a, 7b, 7c, 7d, 7e, 7f) in the tread (4), wherein the rubber material (6a) and the insert material (6b) form a tread (4) with a tire profile with multiple tread blocks layer by layer (8.i), e) curing the tread (4), and f) completing the vehicle tire (1) with further steps. Method according to claim 1, characterized in that at least one further printing device (5a, 5b) is provided which selectively applies a further insert material (6b) in step d) to form insert areas (7; 7a, 7b, 7c, 7d, 7e, 7f) with more than two different materials. Method according to claim 1 or 2, characterized in that the printing devices (5a, 5b) are printing devices based on a 3D technology which apply layer by layer (8.i) the curable rubber material (6a) and the at least one curable insert material (6b) in an additive printing process. Method according to claim 3, characterized in that the printing devices (5a, 5b) are each designed as an extruder which provides the rubber material (6a) or the at least one insert material (6b) in a non-vulcanized, for example viscoelastic, form and applies it via an extruder opening (5c, 5d). Method according to claim 3 or 4, characterized in that the printing device (5a, 5b) is designed as a powder-solidifying printing device, wherein the rubber material (6a) or the at least one insert material (6b) is provided in a photosensitive powder form (9a, 9b, 6ap, 6bp) and is solidified layer by layer at the corresponding positions (P1, P2) by means of a low-energy light source (10). Method according to one of the preceding claims, characterized in that the at least one insert material (6b) is embedded in the rubber material (6a) in a horizontal and / or vertical and / or beveled manner. Method according to one of the preceding claims, characterized in that an insert material (6b) is applied which is harder or softer than the rubber material (6a) to form hard or soft insert areas (7; 7a, 7b, 7c, 7d, 7e, 7f) in the tread strip (4). Method according to one of the preceding claims, characterized in that an electrically conductive insert material (6b) is embedded in the rubber material (6a) to form conductive insert areas (7; 7a, 7b, 7c, 7d, 7e, 7f) in the running strip (4) for transmitting signals and for power supply. Method according to one of the preceding claims, characterized in that cavities (10) are formed in the at least one insert material (6b), in particular for forming noise-reducing insert areas (7f), wherein an insert material (6b) is used which forms a foam-like structure by heat treatment. Method according to one of the preceding claims, characterized in that the rubber material (6a) and the at least one insert material (6b) are color-matched, wherein a readable tread marking is formed in the treads (4), for example in the form of a QR code or a barcode. Method according to one of the preceding claims, characterized in that the tread (4) is produced layer by layer (8.i) directly on the tire blank in step d) or is produced layer by layer (8.i) beforehand and is then applied to the tire blank. Method according to one of the preceding claims, characterized in that a crack-resistant insert material (6b), for example a material with less filler, is embedded in the rubber material (6a) to prevent cracks from forming in the tread (4). Method according to one of the preceding claims, characterized in that a highly thermally conductive insert material (6b) is embedded in the rubber material (6a) for the local removal of heat generated in the tread (4). Method according to one of the preceding claims, characterized in that the rubber material (6a) and the insert material (6b) are applied layer by layer around the circumference in steps d1) and d2) so that the entire tread (4) is built up layer by layer (8.i), or profile block by profile block is completed layer by layer in successive steps to produce the entire tread (4).

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