Tire curing press

Abstract

The invention relates to a tire curing press (1) for vulcanizing rubber curing bladders, comprising a curing press upper part (2) and a curing press lower part (3), wherein the curing press upper part (2) is mounted so as to be movable relative to the curing press lower part (3), and wherein the curing press upper part (2) and the curing press lower part (3) are each electrically heatable by means of at least one heating element (7).

Description

[0001] 202404154

[0002] 1

[0003] Description

[0004] Heating press

[0005] The invention relates to a heating press for vulcanizing rubber bellows, comprising a heating press upper part and a heating press lower part, wherein the heating press upper part is movably mounted relative to the heating press lower part, and wherein the heating press upper part and the heating press lower part can each be heated electrically by means of at least one heating element.

[0006] Furthermore, the invention relates to a method for operating a heating press according to the invention and to a rubber bellows produced with a heating press according to the invention.

[0007] Heating presses for vulcanizing rubber bellows, such as heating bellows for other heating presses, bellows for tire manufacturing machines, or air spring bellows, are known. Known heating presses for vulcanizing rubber bellows feature steam-heated molds in the upper and lower sections of the press, as well as in the core of the bellows press. These molds incorporate steam chambers designed for the prevailing steam pressure of approximately 20 bar. However, at an acceptable cost, the steam chambers cannot be designed to maintain a constant distance between the steam chamber and the rubber bellows. This results in uneven heat input into the rubber bellows, leading to overheated areas and consequently accelerated aging. Furthermore, long warm-up and holding times are required, which hinders high productivity.Especially in the case of rubber bellows with matenalan accumulations or areas with greater material thickness, this regularly leads to a longer process duration and overheated areas.

[0008] Against this background, the invention is based on the objective of designing a heating press for vulcanizing rubber bellows and a method such that a simple design of the heating press is enabled, wherein rubber bellows 202404154

[0009] 2 with short process times and suitable heating or vulcanizing of all areas of the rubber bellows.

[0010] This problem is solved by a heating press according to the features of claim 1, as well as a method and a rubber bellows according to the dependent claims. The subclaims relate to particularly advantageous embodiments of the invention.

[0011] According to the invention, a heating press for vulcanizing rubber bellows is provided, comprising a heating press upper part and a heating press lower part, wherein the heating press upper part is movably mounted relative to the heating press lower part. The heating press upper part and the heating press lower part can each be heated electrically by means of at least one heating element, wherein the at least one heating element is in direct contact with the molds of the heating press upper part and the heating press lower part, respectively, either directly or by means of a thermal conductor. A heat flow in a bellows press core that can be positioned within the rubber bellows can be generated electrically by means of at least one heating element, wherein the heat flow in the bellows press core can be converted from electrical energy into a heat flow.

[0012] Electrical heating of the heating press for rubber bellows, or more precisely, the molds of the upper and lower parts of the heating press and the bellows press core, enables simple installation and maintenance of the heating press. Furthermore, targeted heat application to all areas of the rubber bellows is possible, as electric heating elements can be arranged in a simple manner to ensure uniform heat distribution. In addition, heating elements can also be arranged and designed to provide increased heat flow to areas of the rubber bellows with higher heat requirements, typically due to greater material thickness.

[0013] A preferred embodiment provides that the power density of the heating elements can be adjusted depending on the material thickness of the rubber bellows 202404154

[0014] 3. By means of a controllable or adjustable power output of heating elements, at least also depending on the material thickness of the rubber bellows, it is possible to heat rubber bellows as optimally as possible in every area, even if the material thickness of the rubber bellows is not constant.

[0015] Another preferred embodiment provides that the molds, in areas intended to come into contact with areas of the rubber bellows containing material accumulations, are designed to be heated to a temperature higher than that of the rest of the mold by means of the heating elements. Areas of the molds intended to come into contact with areas of the rubber bellows containing material accumulations are characterized, for example, by the fact that the predominant portion of the heat flow into the rubber bellows, generated by the heating elements located in this area, flows into the area of ​​the rubber bellows containing the material accumulation. Material accumulations are achieved, in particular, by an increased thickness of the rubber bellows.

[0016] Another preferred embodiment provides that the electric heating elements are inductors featuring induction heating. An effective electric heating system can be easily implemented using induction heating.

[0017] Another preferred embodiment provides that the electrical heating elements are resistance heaters, preferably controllable by means of phase-angle control for power regulation. This type of control enables particularly reliable operation with low complexity and low power loss.

[0018] Another preferred embodiment provides that, when the heating press is closed, the distance between two adjacent inductors is smaller than the distance between the inductors and the rubber bellows. This arrangement and positioning of the inductors ensures a particularly constant heat flow into the rubber bellows. 202404154

[0019] 4

[0020] Another preferred embodiment provides that spatially differentiated power levels can be achieved using the electric heating elements. The spatially adjustable power levels or power densities allow for a heat flow into the rubber bellows that can be adapted to the material thickness.

[0021] Another preferred embodiment provides that the bellows press core is made of a metal, in particular a steel.

[0022] Another preferred embodiment provides that the thermal conductor is implemented as a reservoir filled with a fluid, in particular an oil, in the upper part and / or the lower part of the heating press and / or the bellows press core. By designing the thermal conductor as a fluid-filled reservoir, a particularly uniform heat input into the rubber bellows can be achieved with high heat transfer across the entire surface.

[0023] Another preferred embodiment provides that the upper part and / or the lower part and / or the bellows press core can be heated with steam heating in addition to the heating element. The combination of an electric heating element with steam heating enables a simple, uniform, and high heat input into the rubber bellows via steam heating, at least in some areas. Furthermore, the electric heating elements can provide an additional heat flow to areas with lower heat input from the steam heating or areas with increased heat requirements.

[0024] According to the invention, a method for operating a heating press according to the invention is provided, comprising the steps: a) opening the heating press, b) inserting an unvulcanized rubber bellows, c) closing the heating press, alternatively to step b) the unvulcanized rubber bellows can be injected, d) vulcanizing the rubber bellows, 202404154

[0025] 5 e) Starting up the heating press f) Removing the rubber bellows, whereby the vulcanization of the heating bellows is also carried out by means of a heat flow generated by electric heating elements arranged in the molds and the bellows press core.

[0026] By generating a heat flow electrically, using electric heating elements arranged in the molds and the bellows press core, targeted heat delivery to all areas of the rubber bellows is possible. This is because electric heating elements can be easily arranged, controlled, and regulated to ensure uniform heat input into the rubber bellows. Furthermore, the heating elements can also be arranged, controlled, and regulated in such a way that areas of the rubber bellows with increased heat requirements, typically due to greater material thickness, receive a higher heat flow.

[0027] A preferred embodiment provides that the heat flow is controlled or regulated temporally and / or spatially depending on the heat demand of specific areas of the rubber bellows. Suitable vulcanization of all areas of a rubber bellows, even with varying material thicknesses, becomes possible.

[0028] According to the invention, a rubber bellows is provided that is manufactured using a heating press according to the invention and preferably manufactured using a method according to the invention.

[0029] Rubber bellows produced using a heating press according to the invention, and in particular using a method according to the invention, can be manufactured particularly cost-effectively because the heating press is easy to install and maintain. Furthermore, heating times can be minimized. Targeted heat application to all areas of the rubber bellows enables particularly uniformly vulcanized rubber bellows, even if they have uneven material thickness. 202404154

[0030] 6

[0031] 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

[0032] Fig. 1 shows a section of one half of a heating press for vulcanizing rubber bellows with electric heating elements.

[0033] Figure 1 shows a heating press 1 for vulcanizing rubber bellows. The heating press 1 has an upper part 2 and a lower part 3, the upper part 2 being movably mounted relative to the lower part 3. Both the upper part 2 and the lower part 3 are electrically heated by heating elements 7. The heating elements 7 are in contact with the mold 4 of the upper part 2 via an oil-filled reservoir 9. The oil-filled reservoir 9 homogenizes the heat input into the rubber bellows. The bellows press core 6, which is electrically heated by another heating element 7, is located in the area enclosed by the upper part 2 and the lower part 3.

[0034] In this embodiment, the heating elements 7 are each designed as inductors which induce an electric current into the surrounding steel forms 4, 5 or into the bellows press core 6 and thereby heat them.

[0035] The bellows press core 6 forms a gap 8 with the shapes 4 and 5, which is larger at its radially inner end. Accordingly, a bellows vulcanized in the gap 8 exhibits varying material thicknesses and a matenal accumulation at its radially inner end. To generate a greater heat flow in this area of ​​the rubber bellows with matenal accumulation, the heating element 7 in the bellows press core 6 has a higher power density in this area.

[0036] These steam chambers 10 provide additional energy input to the upper heating press section 2, the lower heating press section 3, and the bellows press core 6. 202404154

[0037] 7

[0038] Reference symbol list

[0039] 1 heating press

[0040] 2 Heating press top

[0041] 3 Heating press lower part

[0042] 4 Form

[0043] 5 Form

[0044] 6 bellows press core

[0045] 7 Heating element

[0046] 8 gaps

[0047] 9 Reservoir

[0048] 10 steam chambers

Claims

202404154 8 Patent claims 1. Heating press (1) for vulcanizing rubber bellows, comprising a heating press upper part (2) and a heating press lower part (3), wherein the heating press upper part (2) is movably mounted relative to the heating press lower part (3), wherein the heating press upper part (2) and the heating press lower part (3) can each be heated electrically by means of at least one heating element (7), characterized in that the at least one heating element (7) is in direct and / or thermal contact with the shapes (4, 5) of the heating press upper part (2) and the heating press lower part (3), respectively, wherein a heat flow in a bellows press core (6) that can be positioned within the rubber bellows can be generated electrically by means of at least one heating element (7), wherein the heat flow in the bellows press core (6) can be converted from electrical energy into a heat flow.

2. Heating press (1 ) according to claim 1 characterized in that the power density of the heating elements (7) can be adapted depending on the material thickness of the rubber bellows.

3. Heating press (1) according to claims 1 or 2, characterized in that the forms (4, 5), in areas which are intended to come into contact with areas of the rubber bellows with material accumulations, are arranged to be heated to a temperature increased relative to the further form (4, 5) by means of the heating elements (7).

4. Heating press (1) according to one of the preceding claims, characterized in that the electrical heating elements (7) are inductors having an induction heating system.

5. Heating press (1) according to one of claims 1 to 3, characterized in that 202404154 9 the electrical heating elements (7) is a resistance heating element which is preferably controllable by means of a phase-angle control for power regulation.

6. Heating press (1 ) according to claim 4, characterized in that when the heating press (1 ) is closed, the distance between two inductors arranged next to each other is smaller than the distance of the inductors to the rubber bellows.

7. Heating press (1 ) according to one of the preceding claims, characterized in that different power outputs can be achieved spatially differentiated with the electrical heating elements (7).

8. Heating press (1 ) according to one of the preceding claims, characterized in that the bellows press core (6) is made of a metal, in particular a steel.

9. Heating press (1) according to one of the preceding claims, characterized in that the thermal conductor is provided by a reservoir (9) filled with a fluid, in particular an oil, in the heating press upper part (2) and / or the heating press lower part (3) and / or the bellows press core (6).

10. Heating press (1) according to one of the preceding claims, characterized in that the heating press upper part (2) and / or the heating press lower part (3) and / or the bellows press core (6) can be heated with a steam heating system in addition to the heating element (7).

11. Method for operating a heating press (1) according to any one of claims 1 to 10 comprising the steps: a) opening the heating press (1), b) inserting an unvulcanized rubber bellows, 202404154 10 c) Closing the heating press (1), alternatively to step b) the unvulcanized rubber bellows can be injected, d) Vulcanizing the rubber bellows, e) Opening the heating press (1), f) Removing the rubber bellows, characterized in that the vulcanization of the heating bellows is also carried out by means of a heat flow generated by electric heating elements (7) arranged in molds (4, 5) and a bellows press core (6).

12. Method for operating a heating press according to claim 11, characterized in that the heat flow is controlled or regulated temporally and / or spatially depending on a heat requirement of areas of the rubber bellows.

13. Vehicle tires manufactured with a heating press (1 ) according to one of claims 1 to 10 and preferably with a method according to one of claims 11 to 12.

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