Heat press

Abstract

The invention relates to a heating press (1) for vulcanizing a vehicle tire, wherein the heating press (1) has a heating mold upper part (2), a heating mold lower part (3) and a center mechanism (12), wherein the heating mold upper part (2) and the heating mold lower part (3) each have a sidewall region (7) and a tread region (8).

Description

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

[0002] Heating presses are known that use steam to create excess pressure in a bellows. The bellows presses the vehicle tire into the heating mold and heats it from within. The pressure in the bellows required for shaping determines the temperature when steam is used. It has been shown that this can have a detrimental effect on the vehicle tire, as the necessarily used steam temperature causes excessive heat to be applied to at least some areas of the tire. The vehicle tires are overheated, at least in some areas, and the tire web is damaged or reversible, leading to increased rolling resistance and accelerated aging.

[0003] Against this background, the invention is based on the object of designing a heating press and a method in such a way that a sufficiently high pressure can be generated for shaping, wherein a temperature inside the vehicle tire can be adjusted independently of the pressure, wherein the structure of the heating press is as simple as possible and can preferably be retrofitted in a simple form to existing heating presses and the heating press has a good thermal efficiency.

[0004] 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.

[0005] According to the invention, a heating press is provided for vulcanizing a vehicle tire, preferably a two-wheeler tire, in particular a bicycle tire. The heating press comprises an upper mold part, a lower mold part, and a center mechanism. The upper mold part and the lower mold part each have a sidewall region and a tread region, and the center mechanism can generate a process pressure by means of a gas.

[0006] Because the upper and lower mold sections each have a sidewall area and a tread area, which together form, among other things, the entire tread area of ​​a vehicle tire, additional components for shaping the vehicle tire, such as a container with movable segments, are eliminated. This enables a particularly cost-efficient heating press both in production and operation.

[0007] Generating process pressure through the center mechanism using a gas, i.e., a dry gas that is not water vapor, has proven advantageous. At the process pressures required for shaping inside the vehicle tire, the temperatures required for water vapor are higher than is advantageous for heating vehicle tires. Therefore, in heating presses according to the invention, it has proven advantageous if the pressure inside the vehicle tire is not generated using water vapor, but rather using a gas. High pressures are thus possible even at low temperatures inside the vehicle tire. This enables a particularly simple design of a heating press and particularly suitable heating of the vehicle tire inside the vehicle tire.

[0008] A preferred embodiment provides for the center mechanism to have a bellows, wherein the bellows can preferably be positioned and / or aligned in the heating press by means of a bellows mount. This avoids any interference in the bead area of ​​the vehicle tire, as can occur if the vehicle tire is sealed directly to the center mechanism. Positioning the bellows in the heating press by means of a bellows mount enables highly reproducible and easily automated positioning of the bellows in the vehicle tire.

[0009] A further preferred embodiment provides that the bellows can be positioned in the vehicle tire by means of the bellows mount in such a way that twisting of the vehicle tire along its circumferential direction is avoided when the bellows is filled with process pressure. A bellows mounted on the center mechanism in such a way enables the bellows to expand without twisting when subjected to process pressure, with good reproducibility. When pressure is applied, no torsional forces are transmitted to the vehicle tire to be heated, so that the vehicle tire can exhibit particularly good concentricity after vulcanization.

[0010] A further preferred embodiment provides that the sidewall regions of the heating press can be reproducibly aligned with each other and with a bellows receptacle with a small tolerance. A small tolerance between the sidewall regions of the heating press and the bellows receptacle enables particularly reproducible positioning of the vehicle tire in the heating press, so that it is subjected to only very small torsional moments and undesirable forces during vulcanization.

[0011] A further preferred embodiment provides that the temperature of the gas flowing into the bellows is adjustable, preferably adjustable during a heating process, and more preferably adjustable in such a way that heating and cooling of the vehicle tire is possible. This enables the implementation of particularly advantageous heating curves both for the vehicle tire and with regard to process times.

[0012] A further preferred embodiment provides that the process pressure in the bellows is controllable or adjustable during the heating process. Adjusting the process pressure during the heating process can prevent unnecessarily high process pressure, which can arise from heating the gas. Furthermore, the heat flow into the vehicle tire interior can be reduced while maintaining a constant gas temperature by reducing the process pressure. The thermal efficiency of the heating press can be improved.

[0013] Another preferred embodiment provides that the center mechanism is configured to seal the tire from the environment and to ventilate and aerate it during the heating process. Such a center mechanism eliminates the need for a bellows. This eliminates waste due to defective bellows. Furthermore, costs for the bellows, as well as the installation costs of the bellows and downtime of the heating press, are eliminated.

[0014] According to the invention, a method for vulcanizing a vehicle tire is provided, in particular with a heating press according to the invention, comprising the steps: a) Inserting the vehicle tire into the heating press, b) generating a first process pressure with a gas in the vehicle tire or in a bellows, c) Closing the heating press by moving the upper and lower parts of the heating mould together, d) generating a second process pressure with a gas in the vehicle tire or bellows, e) Vulcanizing the vehicle tire, f) Reducing the process pressure in the vehicle tire or bellows, g) Opening the heating press, h) Removing the vulcanised vehicle tyre from the sidewall areas and the tread areas of the heating press, i) Removing the vulcanized vehicle tire from the bellows and / or the center mechanism.

[0015] Generating process pressure using a gas has proven advantageous because, at the process pressures generated for shaping inside the vehicle tire, the temperatures required for steam are higher than is advantageous for heating vehicle tires. In the method according to the invention, it has therefore proven advantageous if the pressure inside the vehicle tire is not generated with steam, but rather with a gas. High pressures can thus be generated inside the vehicle tire even at low temperatures. This enables a particularly simple construction of a heating press and a particularly suitable method for vulcanizing the vehicle tire inside the vehicle tire.

[0016] A preferred embodiment provides that after step h) and before step i), the vehicle tire is cooled, in particular on its inner side, with a cold gas. Cooling the vehicle tire before removing it from the bellows enables particularly rapid cooling of the vehicle tire by filling the bellows with a cold gas, thus enabling a further adjustable heating curve. Furthermore, the vehicle tires are not removed from the bellows while they are still warm and thus plastically flexible, which enables improved concentricity of the vehicle tire.

[0017] According to the invention, a vehicle tire is provided, produced using a heating press according to the invention and preferably using a method according to the invention. Vehicle tires produced using a heating press according to the invention, in particular using a method according to the invention, can be produced particularly cost-effectively and energy-efficiently with particularly high vulcanization quality. Such vehicle tires can exhibit particularly low rolling resistance and slow aging.

[0018] The invention permits numerous embodiments. To further clarify its basic principle, one of them is shown in the drawing and is described below. This shows in Fig. 1 a heating press for vulcanizing a bicycle tire.

[0019] Fig.Figure 1 shows a curing press 1 for vulcanizing a bicycle tire, comprising an upper mold part 2 and a lower mold part 3. The lower mold part 3 is mounted on a lower press plate 4 and is fixed in place. The upper mold part 2 is fixed to an upper press plate 5 and moves vertically together with the plate, driven by a hydraulic cylinder 6.

[0020] The one-piece heating mold upper part 2 and the one-piece heating mold lower part 3, which are also known as mold parts, each have a sidewall area 7 and a tread area 8, which form the vehicle tire sidewall area and the vehicle tire tread area, respectively.

[0021] The heating mold upper part 2 and the heating mold lower part 3 are heated by a heat source 9 in the form of a steam generator by means of steam lines 10 and steam chambers 11.

[0022] Located centrally in the heating press 1 is a center mechanism 12, which has a supply line 13 and an outlet line 14 through which a gas, namely dry, heated air, flows into the center mechanism 12. The center mechanism 12 supports a bellows 15 on its upper side and on its lower side, thereby aligning it with the heating press 1. The bellows is made of rubber and is filled with the gas by the center mechanism 12.

[0023] To vulcanize a vehicle tire, the vehicle tire is placed in the heating press 1, and a first process pressure is generated using the gas in the bellows 15. The heating press 1 is closed by moving the upper heating mold part 2 and the lower heating mold part 3 together, before a second process pressure is generated using the gas in the bellows 15. The vehicle tire is vulcanized, with the process pressure and the gas temperature in the bellows 15 being adjusted during the vulcanization process. At the end of the vulcanization process, the process pressure in the bellows 15 is reduced to a slight overpressure before the heating press 1 is opened. The vulcanized vehicle tire is removed from the sidewall areas 7 and the tread areas 8 of the heating press 1 before the vehicle tire is removed from the bellows 15. List of reference symbols 1 heating press 2 Heating mold upper part 3 Heating mold lower part 4 lower press plate 5 upper press plate 6 hydraulic cylinders 7 Side wall area 8 Tread area 9 Heat source 10 Steam line 11 Steam chamber 12 Center mechanism 13 Supply line 14 Derivation 15 bellows

Claims

[1] Heating press (1) for vulcanizing a vehicle tire, preferably a two-wheel tire, in particular a bicycle tire, wherein the heating press (1) has a heating mold upper part (2), a heating mold lower part (3) and a center mechanism (12), wherein the heating mold upper part (2) and the heating mold lower part (3) each have a sidewall region (7) and a tread region (8), characterized by , that a process pressure can be generated by means of a gas through the center mechanism (12). [2] Heating press (1) according to claim 1, characterized by that the center mechanism (12) has a bellows (15), wherein the bellows (15) can preferably be positioned and / or aligned in the heating press (1) by means of a bellows holder. [3] Heating press (1) according to claims 1 or 2, characterized bythat the bellows (15) can be positioned in the vehicle tire by means of the bellows holder in such a way that twisting of the vehicle tire along its circumferential direction is avoided when filling the bellows (15) with process pressure. [4] Heating press (1) according to one of the preceding claims, characterized by that the side wall areas (7) of the heating press (1) can be reproducibly aligned with each other and with a bellows receptacle with a small tolerance. [5] Heating press (1) according to one of the preceding claims, characterized by that a temperature control of the gas flowing into the bellows (15) is adaptable, preferably adaptable during a heating process, more preferably adaptable in such a way that heating and cooling of the vehicle tire is possible. [6] Heating press (1) according to one of the preceding claims, characterized by that the process pressure in the bellows (15) is controllable or adjustable during the heating process. [7] Heating press (1) according to claim 1, characterized by that the center mechanism (12) is designed to seal the tire from the environment and to ventilate and aerate it during the heating process. [8] Method for vulcanising a vehicle tyre, in particular with a heating press (1) according to one of the preceding claims, comprising the steps: a) Inserting the vehicle tyre into the heating press (1), b) generating a first process pressure with a gas in the vehicle tyre or in a bellows (15), c) closing the heating press (1) by moving the upper part of the heating mould (2) and the lower part of the heating mould (3) together, d) generating a second process pressure with a gas in the vehicle tyre or in the bellows (15), e) Vulcanizing the vehicle tire, f) reducing the process pressure in the vehicle tyre or bellows (15), g) Opening the heating press (1), h) removing the vulcanised vehicle tyre from the sidewall areas (7) and the tread areas (8) of the heating press (1), i) removing the vulcanized vehicle tire from the bellows (15) and / or the center mechanism (12). [9] A method for vulcanising a vehicle tyre according to claim 8, characterized by that after step h) and before step i) the vehicle tyre is cooled, in particular on its inner side with a cold gas. [10] Vehicle tyres produced with a heating press (1) according to one of claims 1 to 7 and preferably with a method according to claim 8 or 9.

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