Heat press

Abstract

The invention relates to a heating press (1) for vulcanizing a vehicle tire (2), wherein a heating press upper part (4) and the heating press lower part (5) each have a sidewall region and a tread region, wherein the heating press (1) has a center mechanism (3) for supporting the vehicle tire (2).

Description

[0001] The invention relates to a heating press for vulcanizing a vehicle tire, wherein a heating press upper part and a heating press lower part each have a sidewall region and a tread region, wherein the heating press has a center mechanism for supporting the vehicle tire. Furthermore, the invention relates to a method for vulcanizing a vehicle tire and to a vehicle tire.

[0002] There are known curing presses that use steam to create excess pressure in a bellows. The bellows presses the vehicle tire into the heating mold and heats it from the inside. Center-split curing presses have an upper and lower heating press section, each with a sidewall area and a tread area. The upper and lower heating press sections are also heated with steam to vulcanize the vehicle tire. Once the vehicle tire is sufficiently vulcanized, the heating process is ended by reducing the process pressure in the bellows and removing the upper and lower heating press sections from the lower heating press sections. The heated vehicle tire is manually removed from the curing press and, in the process, removed from the lower heating press section.It has been shown that due to the longer contact time of the vehicle tire with the lower part of the heating press compared to the contact time of the vehicle tire with the upper part of the heating press, the vehicle tires are overheated in some areas and show damage to the network or reversions, which leads to increased rolling resistance and accelerated aging.

[0003] Furthermore, more complex curing presses are known that feature a container with molded parts or segments, which feature an automated removal device to ensure that the vehicle tire is removed from the lower parts of the curing press immediately at the end of the curing process. Known removal devices are cost-intensive and require additional installation space. Furthermore, it has been shown that immediately removing the vehicle tire from the bellows at the end of the curing process is disadvantageous, as vehicle tires are prone to plastic deformation in this state, which can lead to, for example, runout errors.

[0004] Against this background, the invention is based on the object of designing a curing press and a method such that no areas of the vehicle tire are overheated during vulcanization, while maintaining the simplest possible design of the curing press and preferably being easily retrofittable to existing curing presses. Furthermore, a short process time should prevent plastic deformation of the vehicle tires upon removal from the curing press.

[0005] This object is achieved by a heating press according to the features of patent claim 1, as well as a method and a vehicle tire according to the independent claims. The subclaims relate to particularly useful developments of the invention.

[0006] According to the invention, a curing press is provided for vulcanizing a vehicle tire, preferably a two-wheeler tire, in particular a bicycle tire. A curing press upper part and a curing press lower part each have a sidewall region and a tread region. The curing press has a center mechanism for supporting the vehicle tire, and the center mechanism is configured to automatically move the vehicle tire in a supported manner to the curing press upper part and the curing press lower part.

[0007] The automated movement of the center mechanism to the upper and lower sections of the curing press, i.e., to all curing press components that shape the vehicle tire, enables the vulcanization process to be completed reliably and with good reproducibility at the end of the curing process on all outer surfaces of the vehicle tire, while the vehicle tire is stored in a particularly gentle manner. This ensures particularly uniform vulcanization of the vehicle tire. Supporting the vehicle tire with the center mechanism enables particularly easy removal of the vehicle tire from the curing press, thus reducing process times.Furthermore, at the end of the heating process, the center mechanism can be fed with a cold gas at a constant process pressure, which leads to accelerated cooling of the vehicle tire and, in particular, counteracts plastic deformation of the vehicle tire when it is removed from the center mechanism.

[0008] A preferred embodiment provides for the center mechanism to have a bellows for supporting the vehicle tire. The use of a bellows for supporting the vehicle tire enables a particularly simple design of the center mechanism. Furthermore, the use of a bellows prevents bearing marks of the center mechanism on the vehicle tire.

[0009] A further preferred embodiment provides that the bellows can be pressurized using steam and / or a gas. The use of steam has proven to be particularly cost-effective, especially when steam is already available for external heating of the heating press. Gases, i.e. dry gases, also make it easy to generate a process pressure, with gases also enabling a temperature-independent process pressure. The use of steam, particularly at the beginning of the heating process, and gas, particularly during the further course of the heating process, in combination has also proven advantageous with regard to the energy input into the vehicle tire.

[0010] A further preferred embodiment provides for the center mechanism to be movable by an electric motor or a hydraulic cylinder. Electric motors and hydraulic cylinders have proven to be cost-effective and particularly reliable for moving the center mechanism.

[0011] A further preferred embodiment provides for the center mechanism to be adjustable to different tire widths. The adjustability of the center mechanism to different tire widths allows for easy conversion of the heating press to different vehicle tires.

[0012] A further preferred embodiment provides for the center mechanism to have bellows clamping rings, whereby the center mechanism can be moved to the upper part of the heating press and the lower part of the heating press while maintaining a constant distance between the bellows clamping rings. A constant distance between the bellows clamping rings during the movement to the upper part of the heating press and the lower part of the heating press enables particularly gentle storage of the vehicle tire at the end of the vulcanization process. For example, this ensures particularly good concentricity of the vehicle tire.

[0013] A further preferred embodiment provides that the center mechanism is configured to clamp the vehicle tire in its bead areas for supporting the vehicle tire in a sealing manner. Clamping the vehicle tire in its bead areas enables the vehicle tire to be clamped directly and sealingly to the center mechanism. This eliminates the need for a bellows, thus eliminating the costs of purchasing bellows and replacing them. Furthermore, rejects due to defective bellows are avoided.

[0014] According to the invention, a method for vulcanizing a vehicle tire is provided, in particular with a heating press according to the invention according to one of the preceding claims, comprising the following steps: a) Placing a vehicle tire in a heating press, b) generating a first process pressure in the vehicle tyre or in a bellows, c) Closing the heating press by moving the upper and lower parts of the heating press together, d) generating a second process pressure in the vehicle tire or bellows, e) Vulcanizing the vehicle tire, f) Reducing the process pressure to a lower overpressure in the vehicle tyre or bellows, g) Opening the heating press, h) moving a center mechanism relative to the heating press upper part and the heating press lower part, i) Removing the vulcanized vehicle tire from the bellows and / or the center mechanism.

[0015] The automated movement of the center mechanism to the upper part of the heating press and the lower part of the heating press enables the vulcanization process to be completed reliably and with good reproducibility on all outer surfaces of the vehicle tire at the end of the heating process. This results in particularly uniform vulcanization of the vehicle tire. Supporting the vehicle tire by the center mechanism enables particularly easy removal of the vehicle tire from the heating press, thereby reducing process times. Furthermore, the center mechanism can be fed with a cold gas at a constant process pressure at the end of the heating process. This leads to accelerated cooling of the vehicle tire and, in particular, counteracts plastic deformation of the vehicle tire upon removal from the center mechanism.

[0016] A preferred embodiment provides that after step h) and before step i), the overpressure in the vehicle tire or bellows is reduced. Reducing the overpressure in the vehicle tire or bellows ensures, on the one hand, particularly gentle storage of the vehicle tire during its movement relative to the upper part of the heating press and relative to the lower part of the heating press, and, on the other hand, enables particularly easy removal of the vehicle tire from the bellows or the center mechanism.

[0017] Another preferred embodiment provides that after step h) and before step i), the vehicle tire is cooled on its inside with a cold gas. This enables particularly rapid cooling of the vehicle tire from the inside, thereby expanding the possibilities for temperature control of the vehicle tire during vulcanization. Rapid cooling also enables a short process time, while avoiding plastic deformation of the still-heated vehicle tire.

[0018] According to the invention, a vehicle tire produced using a heating press according to the invention is provided, which is preferably produced using a method according to the invention. A vehicle tire produced using a heating press according to the invention and, in particular, a method according to the invention can be produced cost-effectively and reliably with particularly high quality in terms of the vulcanization produced and the geometry produced.

[0019] The invention is susceptible of numerous embodiments. To further clarify its basic principle, one of these is illustrated in the drawings and will be described below. Fig. 1 a heating press for vulcanizing a vehicle tire with a center mechanism.

[0020] Fig.1 shows four views of a heating press 1 for vulcanizing a vehicle tire 2, with the heating press 1 being in a different state in each view a) to d). The heating press 1 has a center mechanism 3, a heating press upper part 4, and a heating press lower part 5. The heating press upper part 4 and a heating press lower part 5 each have a sidewall area and a tread area. The heating press 1 is a center-split press; it has no mold segments. The center mechanism 3 is movably mounted on the heating press lower part 5, as can be seen in view c). The center mechanism 3 has a bellows 6, which is provided for supporting and pressurizing the vehicle tire 2.

[0021] To vulcanize the vehicle tire 2, the vehicle tire 2 is placed on the bellows 6 in the heating press 1, and the heating press 1 is closed. The process pressure in the bellows 6 is increased. The vulcanization process is carried out. To end the vulcanization process, the process pressure in the bellows 6 is reduced, and the heating press upper part 4 is moved upwards, as shown in view b). At the same time, or immediately thereafter, the center mechanism 3 is moved upwards so that the vehicle tire 2 is spaced apart from both the heating press upper part 4 and the heating press lower part 5. The vehicle tire 2 is placed on the bellows 6, which is filled with a low pressure. To accelerate the cooling of the vehicle tire 2, a gas exchange takes place in the bellows 6, with cold gas flowing into the bellows 6 and gas heated by the bellows 6 flowing out.

[0022] After the vehicle tire 2 has sufficiently cooled, the vehicle tire 2 is gripped by a gripping device 7. The pressure in the bellows 6 is further reduced, and the bellows 6 is moved downwards out of the vehicle tire 2. The vehicle tire 2 is positioned solely by the gripping device 7. The gripping device 7 removes the vehicle tire 2 from the hot press area and feeds it to further process steps. List of reference symbols 1 heating press 2 vehicle tires 3 Center mechanism 4 Heating press upper part 5 Heating press lower part 6 bellows 7 Gripping device

Claims

[1] Heating press (1) for vulcanizing a vehicle tire (2), preferably a two-wheeler tire, in particular a bicycle tire, wherein the heating press (1) has a heating press upper part (4) and a heating press lower part (5), wherein the heating press upper part (4) and the heating press lower part (5) each have a sidewall region and a tread region, wherein the heating press (1) has a center mechanism (3) for supporting the vehicle tire (2), characterized by that the center mechanism (3) is designed to automatically move the vehicle tire (2) in storage to the heating press upper part (4) and to the heating press lower part (5). [2] Heating press (1) according to claim 1, characterized by that the center mechanism (3) has a bellows (6) for supporting the vehicle tire (2). [3] Heating press (1) according to claims 1 or 2, characterized by that the bellows (6) can be pressurized by means of water vapor and / or by means of a gas. [4] Heating press (1) according to one of the preceding claims, characterized by that the center mechanism (3) can be moved by an electric motor or by means of a hydraulic cylinder. [5] Heating press (1) according to one of the preceding claims, characterized by that the center mechanism (3) can be adjusted to different tire widths. [6] Heating press (1) according to one of the preceding claims, characterized by that the center mechanism (3) has bellows clamping rings, wherein the center mechanism (3) can be moved with a constant distance between the bellows clamping rings to the heating press upper part (4) and to the heating press lower part (5). [7] Heating press (1) according to claim 1, characterized by that the center mechanism (3) is designed to clamp the vehicle tire (2) in its bead areas in a sealing manner for supporting the vehicle tire (2). [8] Method for vulcanizing a vehicle tire (2), in particular with a heating press (1) according to one of the preceding claims, comprising the steps: a) Inserting a vehicle tire (2) into a heating press (1), b) generating a first process pressure in the vehicle tire (2) or in a bellows (6), c) closing the heating press (1) by moving the heating press upper part (4) and the heating press lower part (5) towards each other, d) generating a second process pressure in the vehicle tire (2) or in the bellows (6), e) vulcanizing the vehicle tire (2), f) reducing the process pressure to a lower overpressure in the vehicle tyre (2) or in the bellows (6), g) Opening the heating press (1), h) moving a center mechanism (3) relative to the heating press upper part (4) and the heating press lower part (5), i) Removing the vulcanized vehicle tire (2) from the bellows (6) and / or the center mechanism (3). [9] Method for vulcanizing a vehicle tire (2) according to claim 8, characterized by that after step h) and before step i) the overpressure in the vehicle tyre (2) or in the bellows (6) is reduced. [10] Method for vulcanizing a vehicle tire (2) according to claim 8 or 9, characterized by that after step h) and before step i) the vehicle tire (2) is cooled on its inside with a cold gas. [11] Vehicle tyres (2) produced with a heating press (1) according to one of claims 1 to 7 and preferably produced with a method according to claims 8 to 10.

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