Method for vulcanizing a vehicle tire

Abstract

Method for vulcanizing a vehicle tire, comprising the steps of: a) placing a vehicle tire into a heating press (1), b) generating a first process pressure (PB) in a heating bladder, wherein the heating bladder is arranged inside the vehicle tire, c) closing the heating press (1) over a plurality of partial strokes, wherein in the first partial stroke a vacuum chamber (13) that can be placed under vacuum is formed in the hood interior by vacuum hood parts (3, 4) being brought into contact with one another, wherein a container (7) comprising mold parts (8) is arranged in the vacuum chamber (13).

Description

[0001] 202402843

[0002] 1

[0003] Description

[0004] Method for vulcanizing a vehicle tire

[0005] The invention relates to a method for vulcanizing a vehicle tire comprising the steps: a) placing a vehicle tire in a heating press, b) generating a first process pressure in a heating bellows, wherein the heating bellows is arranged in the vehicle tire, c) closing the heating press over several partial strokes, wherein in the first partial stroke a vacuum chamber that can be placed under vacuum is formed by bringing vacuum hood parts into contact with each other in the hood interior, wherein a container having molded parts is arranged in the vacuum chamber.

[0006] Furthermore, the invention relates to a heating press for vulcanizing a vehicle tire and to a vehicle tire.

[0007] Such a process is known, for example, from WO 2021 / 223822 A1. In the process and heating press known from this publication, a raw tire is vulcanized under vacuum. The heating press comprises a container containing a segmented vulcanization mold, which includes the segments that give the raw tire its shape: sidewalls and bead rings. Heating chambers are provided for tempering the shaping parts, thus forming an external heating element. During vulcanization, the container is surrounded by a two-part, closed hood, which serves for temperature insulation. A heating bellows inserted into the interior of the raw tire provides internal heating by introducing a heating medium, such as hot steam, under pressure into the bellows.Vacuum vulcanization allows a tire to be vulcanized in the vulcanization mold without the need for vent valves. The vacuum inside the mold reduces the atmospheric pressure to 202402843.

[0008] 2 reduced, resulting in a differential pressure between the inside of the hood and the pressure outside the hood on the order of more than 1 bar.

[0009] To mold the raw tire, the heating press closes the hood sections in two partial strokes. In the first partial stroke, the open end of the upper hood section moves axially by a specific distance to immerse itself precisely into the open end of the stationary lower hood section, ensuring a tight, gap-free seal. The hood sections overlap and are vacuum-sealed. The container, including the vulcanization mold, remains open during this process. Before the first partial stroke, the heating bellows inside the raw tire is pressurized with hot steam. This internal pressure remains constant or increases until the tire molding process is complete. After the first partial stroke, the interior of the hood is vacuum-sealed. In the second partial stroke, the hood is completely closed, along with the container and the vulcanization mold.The internal pressure in the heating bellows causes the raw tire to expand during and after vacuum establishment within the still-open vulcanization mold. This allows flowable rubber material from the raw tire to penetrate the spaces between the mold components, contaminating the mold and impairing the quality of the subsequently vulcanized tire. The process time required to vulcanize a vehicle tire is extended by the time required for vacuum generation.

[0010] Against this background, the invention is based on the objective of optimizing the aforementioned method for vulcanizing a vehicle tire and a heating press in such a way as to achieve a reduction in process time, thereby enabling high vehicle tire quality and low rejects, in particular due to shrinkage.

[0011] This problem is solved by a method according to the features of claim 1, as well as a heating press and a vehicle tire according to the dependent claims. The subclaims relate to particularly advantageous embodiments of the invention. 202402843

[0012] 3

[0013] According to the invention, a method for vulcanizing a vehicle tire is provided, comprising the steps: a) placing a vehicle tire in a heating press, b) generating a first process pressure in a heating bellows, wherein the heating bellows is arranged in the vehicle tire, c) closing the heating press over several partial strokes, wherein in the first partial stroke a vacuum chamber, which can be placed under vacuum, is formed by bringing vacuum hood parts into contact with each other in the hood interior, wherein a container with molded parts is arranged in the vacuum chamber, wherein the molded parts have valves for venting in order to allow gas located between the vehicle tire and the molded parts to escape. If the valves are functioning correctly, removing the air from within the vacuum chamber is optional.If a valve malfunctions, the air is removed from the vacuum chamber using a vacuum system to create a vacuum, preferably generating an absolute pressure of 0.1 mbar to 950 mbar in the vacuum chamber. During vacuum generation, the pressure within the heating bellows is reduced, preferably to a pressure 0.1 bar to 1 bar higher than the pressure in the vacuum chamber. The process then proceeds as follows: d) bringing the molded parts into contact with each other to form the outer tire geometry; e) generating a pressure of 8 to 25 bar in the heating bellows; f) vulcanizing the vehicle tire; g) reducing the pressure in the heating bellows, opening the heating press, and removing the vehicle tire.

[0014] The problem according to the invention is solved by performing a case distinction in step c), so that if the valves function correctly, the application of a vacuum is omitted, thereby reducing the process time of the vehicle tires. If a valve exhibits a functional defect, typically after the vulcanization of a large number of vehicle tires, it is currently necessary to clean or replace the valve. This process is time-consuming and leads to increased rejects, also because the heating press according to 202402843

[0015] 4

[0016] The valve must be restored to a required thermal state during repair. According to the invention, this step is unnecessary because, if a valve malfunctions, a vacuum is created in the vacuum chamber before step d), allowing the air to escape. A defective valve thus has less of a negative impact on the processing time of numerous vehicle tires. The heating press can continue to operate, and the valve can be repaired after the container with the molded parts has been removed from the heating press.

[0017] To carry out the process according to the invention without the vehicle tire expanding due to the pressure difference when the pressure in the vacuum chamber is reduced, and thus penetrating between the mold parts of the vulcanization mold, it is necessary to maintain the pressure difference between the bellows and the vacuum chamber within the required range. Therefore, the internal pressure of the bellows is lowered to equalize the pressure differences. The difference between the vacuum in the chamber and the pressure in the heating bellows is essentially at the level before the first partial stroke. This also ensures that the heating bellows continues to hold the vehicle tire, but without the tire expanding undesirably.

[0018] A preferred embodiment provides that a malfunction of a valve is detected automatically or manually. Automated detection of a malfunction of a valve allows the process to run automatically.

[0019] When vacuum hood parts are closed, they form the hood interior.

[0020] The vacuum system includes vacuum hood components, a vacuum pump, and a connection between the vacuum hood components and the vacuum pump.

[0021] The molded parts, together with side panels, create the outer tire geometry.

[0022] Another preferred embodiment provides that in a subsequent, second partial stroke of the hood parts, the container and the vulcanization mold are positioned as far as 202402843

[0023] 5. It is concluded that the distance between the vehicle tire and the molded parts of the vulcanization mold is reduced to 1.00 mm to 2.00 mm, whereby the absolute pressure in the vacuum chamber is maintained at the minimum absolute pressure and the pressure inside the heating bellows is adjusted such that the differential pressure between the pressure in the vacuum chamber and the pressure inside the heating bellows is still balanced to up to ± 0.2 bar relative to the initially set pressure.

[0024] If the container and vulcanization mold were completely closed, there would be a possibility that the residual pressure in the hood would not create a sufficient vacuum, leaving air bubbles between the tire and the mold. These bubbles would then be visible on the surface of the finished vulcanized tire. The slightly open vulcanization mold allows the remaining air to escape without causing uneven tire growth and without creating rubber burrs by allowing flowable rubber material to seep into the remaining narrow gaps between the mold parts.

[0025] Another preferred embodiment provides that, with / after stopping the second partial stroke, the pressure inside the heating bellows is increased to an overpressure of 0.1 bar to 1.5 bar above atmospheric pressure, while the absolute pressure in the vacuum chamber remains at the minimum absolute pressure. The pressure increase inside the heating bellows causes the vehicle tire to expand slightly to such an extent that the volume within the vulcanization mold between the vehicle tire and the mold is reduced without causing undesirable compression of the vehicle tire into the vulcanization mold. This reduced volume also results in an absolute reduction of the remaining air volume.

[0026] Another preferred embodiment provides that, to complete the molding of the vehicle tire in a third partial stroke, the hood parts and together with these the container and the vulcanization mold are completely closed, with the absolute pressure in the vacuum chamber remaining at the minimum absolute pressure and the pressure inside the heating bellows 202402843

[0027] 6. The set overpressure of 0.1 bar to 1.5 bar above atmospheric pressure is maintained. Overall, the invention ensures a gentle forming of the vehicle tire into the heating press without damaging the tire, and the process requires only a short time, particularly in the range of 30 to 120 seconds.

[0028] Another preferred embodiment provides that the pressure inside the heating bellows is reduced by means of a second vacuum system. This reduction of the internal pressure in the heating bellows can be easily achieved using a second vacuum system.

[0029] Another preferred embodiment provides that, at least before and immediately after the first partial stroke, the pressure inside the heating bellows is maintained or adjusted by pulsing the pressure by up to 0.1 bar. Particularly at the beginning of the molding process up to and including the execution of the first partial stroke, it is advantageous if the pressure inside the heating bellows is applied or adjusted in a pulsating manner, with fluctuations of up to 0.10 bar, in order to facilitate the escape of air between the vehicle tire and the heating bellows.

[0030] According to the invention, a heating press for vulcanizing a vehicle tire is provided, in particular for carrying out the method according to the invention, with a vacuum chamber formed from two vacuum hood parts that are movable relative to each other. The vacuum chamber is connected to a vacuum pump for evacuating the vacuum chamber, wherein a container having molded parts is arranged inside the vacuum hood parts.

[0031] The molded parts are arranged such that they can be spaced apart from each other while the vacuum hood parts are forming the vacuum chamber. The heating press has a heating bellows for placement inside a vehicle tire, and the molded parts have vent valves to allow any gas located between the vehicle tire and the molded parts to escape. 202402843

[0032] 7

[0033] The problem addressed by the invention is solved by eliminating the need to apply a vacuum when the valves are functioning correctly, thereby reducing the processing time for the vehicle tires. If a valve malfunctions, a vacuum can be created in the vacuum chamber. A defective valve thus has a less negative impact on the processing time of a large number of vehicle tires.

[0034] According to the invention, a vehicle tire is produced using a method according to the invention, preferably using a heating press according to the invention. Vehicle tires produced using the method according to the invention do not exhibit any defects caused by penetration between the mold parts of the vulcanization mold. They are of higher quality and more cost-effective to produce because scrap is reduced, which occurs when the vehicle tire experiences increased penetration between the mold parts of the vulcanization mold.

[0035] 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

[0036] Fig. 1 shows a heating press from the prior art in the open state,

[0037] Fig. 2 shows the heating press from Fig. 1 in a closing phase after a first partial stroke,

[0038] Fig. 3 shows the heating press from Fig. 1 and Fig. 2 in the closed state after a second partial stroke.

[0039] Fig. 4 is a diagram illustrating successive process phases in the inventive forming of a vehicle tire in a heating press, which can be designed similarly to Figs. 1 to 3.

[0040] The heating press 1 shown in Figures 1 to 3 is part of the prior art and is a heating press as shown and described in WO 2021 / 223822 A1 and is intended for vulcanizing a vehicle tire, preferably a pneumatic tire. This heating press 1 is referred to below as 202402843.

[0041] Section 8 describes the main components and summarizes their basic function. The heating press 1 comprises a press upper part 2, which is connected to a hood upper part 3, and a press lower part 5, which is connected to a hood lower part 4. It includes the associated mechanisms for positioning the raw tire to be vulcanized, actuating the components of a vulcanization mold 6, introducing the heating media, and demolding the finished vulcanized tire. The vulcanization mold 6 is located in a container 7, which is enclosed during the vulcanization process by the hood consisting of hood upper part 3 and hood lower part 4. The container 7 is a conventional, prior art container that contains the vulcanization mold 6, in this case a segmented mold with a segment ring 6a with profile elements and segment shoes 6b, as well as side shells 6c, and has a closing ring 7a.A heating bellows, which is not shown, is arranged in a known manner and is inserted into the interior of the raw tire positioned in the vulcanization mold 6 before the heating press 1 is closed, and is filled under pressure with a gas, such as a heating medium, in particular hot steam, in order to center the raw tire in the mold from the inside.

[0042] The upper hood part 3 and the lower hood part 4 are designed to be airtight or vacuum-tight (Fig. 2, Fig. 3), enclose a vacuum chamber 13 when closed, and have seals 9 between the hood parts 3 and 4 and a central mechanism 10 for this purpose. To make the closed hood consisting of the two hood parts 3 and 4 vacuum-tight, one of the seals 9 is a ring seal in the lower hood part 4.

[0043] A vacuum can be created inside the closed hood by means of a vacuum system with a pump 11 and a vacuum tank 12, so that the molded parts 8 of the vulcanization mold 6 do not have any venting valves.

[0044] Fig. 2 shows the heating press 1 during a closing phase after a first partial stroke, wherein the open end of the hood upper part 3 has moved axially by a certain stroke in order to plunge into the open end of the stationary hood lower part 4 without play, wherein the hood parts 3 and 4 meet each other. 202402843

[0045] The 9 overlap. The vulcanization mold 6 is open, the hood is vacuum-sealed by the ring seal 9. To create a vacuum in the vacuum chamber 13, the connection between the vacuum tank 12 and the hood is opened.

[0046] Fig. 3 shows the heating press 1 in its closed state after a second partial stroke. After a vacuum has been created in the closed hood as shown in Fig. 2, the second partial stroke completely closes the evacuated vulcanization mold 6 and closes the connection between the vacuum tank 12 and the hood.

[0047] After the tire has been vulcanized, the interior of the hood is opened via a valve and the heating press 1 is opened to unload the fully vulcanized tire from the vulcanization mold 6.

[0048] With reference to Figure 4, the process according to the invention for molding a vehicle tire until a heating press 1, which can basically comprise the components of the heating press 1 shown in Figures 1 to 3, is now described, specifically for the case where a vacuum is created in the space enclosed by the hood parts 3, 4. Therefore, for a better understanding of the invention, the following description will mention components of the heating press 1 shown in Figures 1 to 3 and use the reference numerals assigned to them.

[0049] The forming process is described in terms of successive phases 1 to 7. In Fig. 4, the time axis runs along the abscissa with time in [see], the pressure in [bar] is plotted along the left ordinate, and the distance between the upper and lower press parts in [mm] is plotted along the right ordinate for an exemplary heating press 1. The solid line in Fig. 4 is the status line STH of the heating press 1, which has no relation to pressure but is related to the time axis and symbolizes the respective status of the heating press 1. The dashed line shows the pressure Pv between the hood parts 3, 4 and in the vacuum chamber 13, and the dotted line follows the pressure PB inside the heating bellows. 202402843

[0050] 10

[0051] In Phase 1, the heating press 1 is open (line segment a) of the status line STH), the two hood sections 3 and 4 are extended, the vehicle tire is inserted into the open vulcanization mold 6 in the usual manner, the heating bellows is located inside the vehicle tire and is pressurized from the inside with a gas, for example, superheated steam or nitrogen, to an internal pressure of 0.10 bar to 0.70 bar (absolute) (line segment c) to fix the vehicle tire in place. A slight pulsation of the pressure in the range of approximately 0.10 bar, symbolized by a zigzag line, facilitates the escape of air between the vehicle tire and the heating bellows. Outside the vehicle tire and outside the container 7 and the heating press 1, there is an atmospheric overpressure on the order of 1.00 bar (see line segment b) of the dashed line in Phase 1).

[0052] After the loader (not shown), which has inserted the vehicle tire into the vulcanization mold 6, has swung out of the heating press 1, phase 2 begins. The heating press 1 is closed via a first partial stroke (analogous to Fig. 2), see section d) of the status line STH, by closing the hood parts 3, 4, so that the vacuum chamber 13 is also closed, see section g) of the status line STH. Atmospheric overpressure still prevails around the vehicle tire, see section e) of the line Pv. The pressure PB inside the heating bellows remains at the same level as before, see section f).

[0053] In the next phase, phase 3, the air is removed from vacuum chamber 13 by means of the vacuum system. The previously existing overpressure around the vehicle tire is reduced to almost 0 bar, see line segment h) of the pressure Pv line. Simultaneously, the pressure PB inside the heating bellows is reduced by means of another vacuum system, see line segment j). To keep the relative overpressure inside the heating bellows largely constant, the pressure PB is reduced to a negative pressure relative to atmospheric pressure until the pressure difference between pressure Pv and pressure PB results in a pressure PR according to the dotted line in Fig. 4, see line segment i). During this process, the gas inside the heating bellows is removed by means of another vacuum system. The 202402843

[0054] 11

[0055] Heating press 1 remains stationary during phase 3; it will not be closed further, see horizontal line segment k) of the status line STH.

[0056] In phases 1 to 3, the pressure PB inside the heating bellows pulsates by up to 0.1 bar to assist the escape of air between the vehicle tire and the heating bellows, see the jagged curve of the pressure PB.

[0057] In the subsequent phase 4, the pressure PB in the heating bellows does not pulsate in the exemplary embodiment; this measure is not necessary in this phase, whereby the absolute pressure in the heating bellows is kept constant at the final pressure from phase 3 (see line segment n). Due to the decreasing absolute overpressure in the vacuum chamber 13 around the vehicle tire, the absolute pressure in the vacuum chamber 13 (see line segment m) decreases further slightly, resulting in a constant relative overpressure (see line segment I) along the PR line. Phase 4 continues until the minimum absolute pressure around the vehicle tire or in the vacuum chamber 13, as determined by the vacuum system, is reached. During this step, the heating press 1 remains stationary and does not close any further, as symbolized by line segment o) of the status line STH of the heating press 1.

[0058] In phase 5, the heating press 1 is further closed by means of a second partial stroke, see line segment s) of the status line STH. This also sets the container 7 and the molded parts 8 in the vulcanization mold 6 in a closing motion and pushes them towards the vehicle tire, but only to a distance of a few millimeters, specifically 1.00 mm to 2.00 mm, between the molded parts 8 of the vulcanization mold 6 and the vehicle tire. The absolute pressure in the vacuum chamber 13 around the vehicle tire continues to be maintained at the minimum level, see line segment q) in the line of pressure Pv. As the volume in the vacuum chamber 13 decreases, the absolute proportion of residual air in the vacuum chamber 13 also decreases. The pressure PB in the heating bellows, see the corresponding line segment r), and the pressure PR continue to be held at the level from phase 4 and remain constant (see line segment p). 202402843

[0059] 12

[0060] In the next phase, phase 6, the heating press 1 stops the closing process from phase 5, as shown by the horizontal line segment w) of the status line STn of heating press 1. Simultaneously, the pressure PB inside the heating bellows is increased, as shown by line segment u) along the pressure PB curve. The pressure inside the heating bellows is set to a pressure between 0.10 bar and 1.50 bar above atmospheric pressure, resulting in a higher relative overpressure between the pressure PB in the heating bellows and the pressure Pv in the vacuum chamber 13, or the space around the vehicle tire, in the range of 1.10 bar to 2.50 bar, as shown by line segment t). The absolute pressure in the vacuum chamber 13 continues to be maintained at a minimum level, as shown by line segment v) along the pressure Pv curve.In this phase, the vehicle tire begins to grow slightly due to the increased internal relative pressure, whereby the already very small volume in vacuum chamber 13, which may still contain residual air, becomes increasingly smaller. The vulcanization mold is still minimally open.

[0061] 6, see Phase 5, allows the last remaining air to be removed without causing the vehicle tire to grow unevenly, since vulcanization form 6 limits the maximum growth.

[0062] In the final phase of forming or closing the heating press 1, the phase

[0063] In phase 7, a third partial stroke completely closes the heating press 1, and the closing pressure is applied to the container 7 and to hold and join the molded parts 8 of the vulcanization mold 6. The heating press 1, including container 7 and vulcanization mold 6, is now completely closed, as shown in Fig. 3. The area around the vehicle tire remains at the minimum possible pressure level and is therefore almost zero (see line segment z). The pressure inside the heating bellows continues to be maintained at the final level from phase 6 (see line segment x) of the pressure PB curve). Line segment zz) in the status line STH symbolizes the third partial stroke, and line segment y) shows the pressure PR curve.

[0064] The duration of the phases in [see] 3 to 7 is, according to a preferred embodiment, as follows:

[0065] Phase 3: 10 to 30

[0066] Phase 4: 20 to 50 202402843

[0067] 13

[0068] Phase 5: 5 to 15

[0069] Phase 6: 5 to 15

[0070] Phase 7: up to 5

[0071] Once the locking mechanism of container 7 is complete, the heating process begins, typically by activating the internal heating system through further filling of the heating bellows with the high-pressure medium, which also provides the energy for vulcanization via the internal heating. This also presses the vehicle tire into the shaping components 8 of the nearly airless vulcanization mold 6, leaving no visible air bubbles on the tire surface.

[0072] After completion of the vulcanization process, the vacuum chamber 13 is vented, the heating press 1 and the container 7, including the vulcanization mold 6, are opened. The vulcanized vehicle tire is released and can be unloaded.

[0073] In other versions, the heating press used for vulcanization has more than two hood parts.

[0074] According to the invention, the molded parts can have 8 valves, so that the creation of a negative pressure in the vacuum chamber 13 is unnecessary, provided the valves function correctly. This allows phases 3, 4, and 6 to be omitted and phases 5 and 7 to proceed without interruption. Process time and heat losses are reduced.

[0075] 202402843

[0076] 14

[0077] Reference symbol list

[0078] 1 heating press

[0079] 2 Press top

[0080] 3 Hood top part

[0081] 4 Hood base 5 Press base

[0082] 6 Vulcanization form

[0083] 6a Segment ring

[0084] 6b Segment shoe

[0085] 6c side panel 7 containers

[0086] 7a Closure

[0087] 8 Molded part

[0088] 9 Seal

[0089] 10 Center mechanism 11 Pump

[0090] 12 vacuum tank

[0091] 13 Vacuum chamber a) to zz) Line segments

[0092] PB Pressure in heating bellows PR Differential pressure

[0093] PV pressure around / within the hood parts

[0094] STH status line of the heating press

Claims

1. 202402843 15 Patent claims 1. A method for vulcanizing a vehicle tire comprising the steps of: a) placing a vehicle tire in a heating press (1), b) generating a first process pressure (PB) in a heating bellows, wherein the heating bellows is arranged in the vehicle tire, c) closing the heating press (1) over several partial strokes, wherein in the first partial stroke a vacuum chamber (13) that can be vacuum-sealed is formed in the interior of the hood by bringing vacuum hood parts (3, 4) into contact with each other, wherein a container (7) having molded parts (8) is arranged in the vacuum chamber (13), characterized in that the molded parts (8) have valves for venting in order to allow gas located between the vehicle tire and the molded parts (8) to escape, wherein, if the valves are functioning correctly, the removal of air from the vacuum chamber (13) is optional, wherein, if a valve malfunctions, the air from the vacuum chamber (13) is removed.namely by means of a vacuum system for generating a vacuum, wherein preferably 0.1 mbar to 950 mbar absolute pressure is generated in the vacuum chamber (13), wherein during the generation of the vacuum in the vacuum chamber (13) the pressure inside the heating bellows is reduced, preferably such that the pressure (PB) inside the heating bellows is 0.1 bar to 1 bar higher than the pressure (Pv) in the vacuum chamber (13), d) bringing the molded parts (8) into contact with each other to form an outer tire geometry, e) generating a pressure (PB) of 8 to 25 bar in the heating bellows, f) vulcanizing the vehicle tire, g) reducing the pressure (PB) in the heating bellows, opening the heating press (1) and removing the vehicle tire. 202402843 16 2. Method according to claim 1, characterized in that a faulty functioning of a valve is detected automatically or manually.

3. Method according to claim 1 or 2, characterized in that in a next, second partial stroke of the hood parts (3, 4) the container (7) and the vulcanization mold (6) are closed to such an extent that the distance between the vehicle tire and the mold parts (8) of the vulcanization mold (6) is reduced to 1.00 mm to 2.00 mm, wherein the absolute pressure (Pv) in the vacuum chamber (13) is maintained at the minimum absolute pressure (PB) and the pressure inside the heating bellows is adjusted such that the differential pressure (PB) between the pressure (Pv) in the vacuum chamber and the pressure (PB) inside the heating bellows is still balanced to up to ± 0.2 bar relative to the initially set pressure.

4. Method according to claim 3, characterized in that with / after stopping the second partial stroke the pressure (PB) inside the heating bellows is increased to an overpressure of 0.1 bar to 1.5 bar above atmospheric pressure, wherein the absolute pressure (Pv) in the vacuum chamber continues to be kept at the minimum absolute pressure.

5. Method according to claim 4, characterized in that, to complete the molding of the vehicle tire in a third partial stroke, the hood parts (3, 4) and together with these the container (7) and the vulcanization mold (6) are completely closed, wherein the absolute pressure (Pv) in the vacuum chamber (13) continues to be maintained at the minimum absolute pressure and the pressure (PB) inside the heating bellows continues to be maintained at the set overpressure of 0.1 bar to 1.5 bar above atmospheric pressure.

6. Method according to one of the preceding claims, characterized in that the pressure (PB) inside the heating bellows is reduced by means of a second vacuum system. 202402843 17 7. Method according to one of the preceding claims, characterized in that at least before and immediately after the first partial stroke the pressure (PB) inside the heating bellows is maintained or adjusted by pulsing the pressure by up to 0.1 bar.

8. Heating press for vulcanizing a vehicle tire, in particular for carrying out a method according to one of the preceding claims, comprising a vacuum chamber formed from two vacuum hood parts movable relative to each other, wherein the vacuum chamber is connected to a vacuum pump for evacuating the vacuum chamber, wherein molded parts (8) having a container are arranged within the vacuum hood parts, wherein the molded parts (8) are arranged such that the molded parts (8) are spaced apart from each other while the vacuum hood parts are formed to form the vacuum chamber, wherein the heating press has a heating bellows for arrangement within a vehicle tire, characterized in that the molded parts (8) have valves for venting in order to allow gas located between the vehicle tire and the molded parts (8) to escape.

9. Heating press according to claim 8, characterized in that the heating bellows is connected to a vacuum pump.

10. Vehicle tires manufactured using a method according to one of claims 1 to 10. 7, preferably with a heating press according to one of claims 8 to 9.

Images