Heat press

Abstract

The invention relates to a heating press (1) for vulcanizing a vehicle tire, comprising a heating press upper part (2) and a heating press lower part (3), wherein a container (4) having a heated upper side wall shell (5) and heated mold segments (10) is arranged on the heating press upper part (2), and wherein the heating press lower part (3) has a heated lower side wall shell (13). The lower side wall shell (13) is heated by means of a lower container plate (14) and the upper side wall shell (5) is heated by means of an upper container plate (7), wherein the lower side wall shell (13) is heated directly by means of a lower container plate (14) and / or the upper side wall shell (5) is heated directly by means of an upper container plate (7).

Description

The invention relates to a heating press and to a method for vulcanizing a vehicle tire. The heating press has a heating press top part and a heating press bottom part, wherein a container having a heated upper side wall shell and heated mold segments is arranged on the heating press top part, wherein the heating press bottom part has a heated lower side wall shell.Heating presses are known whose mold segments and side wall shells are heated by means of steam. These heating presses have high thermal losses and low thermal efficiency because of their construction and the type of supply of their thermal energy. The simultaneous setting of different temperatures at different positions of the heating press is not possible or is only possible to a limited extent. Furthermore, heating presses with electrically heated mold segments and side wall shells are also known. These heating presses likewise have a low thermal efficiency because of their construction, in particular because of the positioning of the electric heating means. Furthermore, such heating presses regularly have disadvantages with regard to their production costs and operating and equipment costs. Disadvantages of such heating presses with regard to the compatibility of containers in different works are likewise known.Against this background, the object of the invention is to design a heating press and a method in such a way that they have a particularly high thermal efficiency and differently temperature-controlled regions are made possible in the heating press, low production costs and operating and setup costs and a high compatibility of containers being made possible.This object is achieved with a heating press according to the features of claim 1 and a method according to the subordinate claim. The dependent claims relate to particularly expedient developments of the invention.According to the invention, a heating press for vulcanizing a vehicle tire is therefore provided, having a heating press upper part and a heating press lower part, wherein a container having a heated upper side wall shell and heated mold segments is arranged on the heating press upper part. The lower heating press part has a heated lower side wall shell, wherein the lower side wall shell is heated by means of a lower container plate and the upper side wall shell is heated by means of an upper container plate. The lower side wall shell is heated by means of the lower container plate and or the upper side wall shell is heated by means of the upper container plate, wherein a heat flow is generated in the lower container plate and or the upper container plate, wherein the heat flow in the lower container plate and or upper container plate is converted from electrical energy into a heat flow.The heat flow in at least one of the container plates is generated by supplying electric current to the container plate and converting it into heat in the container plate. The conversion of the electric current into heat can take place, for example, by means of an electric resistor which is arranged in the container plate. Alternatively, the electric current can be induced in the container plate, for example with an induction coil, so that an electric current flows through at least partial regions of the container plate itself and is converted into heat in the latter. The heat flow generated is conducted from the container plate into the side wall shell, in that the container plate and the side wall shell are preferably in planar contact with one another. A means for improving the heat transfer can be arranged between the container plate and the side wall shell.By generating a heat flow from an electric current in the container plate, different regions of the heating press can be heated independently of one another. Furthermore, the path of the heat flow up to the heating tire is particularly short, so that a high thermal efficiency is achieved and tire regions with high temperature differences from one another can be heated.A preferred embodiment provides that the heat flow is generated in the container plates and or the mold segments by means of electrical resistors, in particular by means of a heating coil. This achieves a cost-effective and reliable conversion of electrical current into heat.A further preferred embodiment provides that the heat flow is generated by induction coils by an inductively generated eddy current in the lower container plate and or upper container plate and or the mold segments. Induction coils have proven to be particularly low-maintenance possible. Convert electrical energy into heat.A further preferred embodiment provides that the induction coils are spaced apart from the lower container plate and or upper container plate by means of a thermal insulator. The thermal insulation of the induction coils from the heated container plates reduces the temperature of the induction coils during operation, thus increasing the durability of the induction coils. It is understood that the materials surrounding the induction coils, which are arranged on the same side of the thermal insulator as the induction coils, are selected such that no or only a very slight conversion of electrical energy into thermal energy takes place therein.A further preferred embodiment provides that the induction coils are positioned in an upper press plate and or a lower press plate and or in the closing ring. This positioning of the induction coils has proven to be particularly advantageous since, as a result, when a container is changed in a heating press, the induction coils remain in the heating press, whereby the effort for refitting is reduced. A further advantage is that only the heating presses need to be provided with induction coils and not the containers. This also increases the compatibility of the containers, since, for example, different voltages at different heating presses are irrelevant for a container change. Furthermore, due to the higher number of containers compared to heating presses, the required number of induction coils can be reduced.A further preferred embodiment provides that the electrical resistors and or the induction coils are divided into at least two, preferably at least three and more preferably at least four, mutually coaxially arranged sub-regions which can be used independently of one another. This makes it possible to heat only that region of the container panels which has to be heated for the present tire size.According to the invention, a method for operating a heating press for vulcanizing a vehicle tire is provided, in particular a heating press according to the invention, having the steps:generating a heat flow in the lower container plate and or the upper container plate, wherein the heat flow in the lower container plate and or the upper container plate is converted from electrical energy into a heat flow,positioning a vehicle tire in the heating press,curing the vehicle tire,terminating the vulcanization process and removing the vehicle tire.The invention permits numerous embodiments. To further clarify its basic principle, two of them are illustrated in the drawings and are described below. These show in FIG. 1 shows a heating press with electric resistances of heated container plates; FIG. 2 shows a heating press with inductively heated container plates.FIG. 1 shows a heating press 1 for vulcanizing a vehicle tire, having a heating press top part 2 and a heating press bottom part 3. The upper container plate 7 is thermally insulated from an upper press plate 9 by means of a thermal insulator 8.The container 4 further comprises mold segments 10 which are indirectly heated by segment shoes 12 by means of electrical resistors 6 which are arranged in a closing ring 11. The closing ring 11 has a thermal insulator 8 which is arranged such that the electrical resistors 6 are thermally connected to the segment shoes 12 and are thermally separated from the radially outer region of the closing ring 11.The heating press lower part 3 has a heated lower side wall shell 13, which is heated by means of a lower container plate 14. For this purpose, the lower container plate 14 has electrical resistors 6 and a thermal insulator 8. The thermal insulator 8 is arranged in such a way that the electrical resistors 6 are thermally connected to the lower side wall shell 13 and are thermally decoupled from the radially outer region of the lower container plate 14 and from a lower press plate 15.FIG. 2 shows a heating press 1 with inductively heated container plates 7, 14, which differs from the embodiment of FIG. 1 with regard to heating the side wall shells 5, 13 and the mold segments 10, as described below. The other components of the heating press 1 correspond to the components of the embodiment of FIG. 1. The heating press 1 has induction coils 16 which are arranged in the lower press plate 15 and the upper press plate 9. The induction coils 16 are separated from the lower container plate 14 or from the upper container plate 7, in which they generate an eddy current and thus heat it, in each case by a thermal insulator 8. In the closing ring 11, further induction coils 16 are arranged, which are likewise thermally decoupled from the region of the closing ring 11 heated by them by a thermal insulator 8. This arrangement of the induction coils 16 ensures that the induction coils 16 are arranged in the colder region of the heating press 1, as a result of which a longer durability of the induction coils 16 is achieved.List of reference characters1 Heating press 2 Heating press upper part 3 Heating press lower part 4 Container 5 Upper side wall shell 6 Electrical resistor 7 Upper container plate 8 Thermal insulator 9 Upper press plate 10 Forming segment 11 Closing ring 12 Segment shoe 13 Lower side wall shell 14 Lower container plate 15 Lower press plate 16 Induction coil

Claims

A heating press (1) for vulcanizing a vehicle tyre, having a heating press upper part (2) and a heating press lower part (3), wherein a container (4) having a heated upper side wall shell (5) and heated mould segments (10) is arranged on the heating press upper part (2), wherein the heating press lower part (3) has a heated lower side wall shell (13), wherein the lower side wall shell (13) is heated by means of a lower container plate (14) and / or the upper side wall shell (5) is heated by means of an upper container plate (7), characterized in that a heat flow is generated in the lower container plate (14) and / or the upper container plate (7), wherein the heat flow is converted from electrical energy into a heat flow in the lower container plate (14) and / or upper container plate (7).Heating press (1) according to claim 1, characterised in that the heat flow in the container plates (7, 14) and / or the mould segments (10) is generated by means of electrical resistors (6), in particular by means of a heating coil.Heating press (1) according to claim 1, characterised in that the heat flow is generated by induction coils (16) by an inductively generated eddy current in the lower container plate and / or upper container plate and / or the mould segments (10).Heating press (1) according to claim 3, characterised in that the induction coils (16) are spaced apart from the lower container plate (14) and / or upper container plate (7) by means of a thermal insulator (8).Heating press (1) according to one of the preceding claims, characterized in that the induction coils (16) are positioned in an upper press plate (9) and / or a lower press plate (15) and / or in the closing ring (11).Heating press (1) according to one of the preceding claims, characterized in that the electrical resistors (6) and / or the induction coils (16) are divided into at least two, preferably at least three and more preferably at least four, mutually coaxially arranged sub-regions which can be used independently of one another.Method for operating a heating press (1) for vulcanization of a vehicle tyre, in particular a heating press (1) according to one of the preceding claims, having the steps: - generating a heat flow in the lower container plate (14) and / or the upper container plate (7), wherein the heat flow in the lower container plate (14) and / or upper container plate (7) is converted from electrical energy into a heat flow, - positioning a vehicle tyre in the heating press (1), - vulcanization of the vehicle tyre, - termination of the vulcanization process and removal of the vehicle tyre.

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