Device for vulcanizing a vehicle tire and method for vulcanizing a tire in such a device

Abstract

Device for vulcanizing a vehicle tire with a heating press containing a vulcanization mold (2) and with an internal heater with a heating bladder (11) lying on the inside of the tire and an external heater which heats the outside of the vehicle tire (10) via components of the vulcanization mold (2), wherein the heating bladder (11) is held between an upper bladder plate (13a) and an upper bladder clamping ring (14a) and between a lower bladder plate (13b) and a lower bladder clamping ring (14b), and with a piston rod (15) which is operatively connected to the upper bellows plate (13a) and has a section (15a) located inside the heating bladder when the tire (10) is molded in, for actuating the retraction and extension of the heating bladder (11) into and out of the tire. The internal heating is formed by at least one infrared radiation element (16a, 16b, 16c) which is arranged on the section (15a) of the piston rod (15) located inside the bladder when the tires are molded in.

Description

[0001] The invention relates to a device for vulcanizing a vehicle tire with a heating press containing a vulcanization mold and with an internal heater with a heating bladder attached to the inside of the tire and an external heater which heats the outside of the vehicle tire via components of the vulcanization mold, the heating bladder being held between an upper bladder plate and an upper bladder clamping ring and between a lower bladder plate and a lower bladder clamping ring, and a piston rod operatively connected to the upper bladder plate and having a section located inside the bladder when the tire is molded in, for actuating the retraction and extension of the bladder into and out of the tire. The invention further relates to a method for vulcanizing a tire in such a device.

[0002] The vulcanization of a vehicle tire usually takes place in a heating press with a vulcanization mold into which the green tire is inserted, the heating bladder is positioned inside the tire, the vulcanization mold is closed, and the green tire is vulcanized under the influence of heat and pressure. The heating bladder is usually exposed to a heating medium, such as hot steam, so that the necessary vulcanization energy is supplied to the green tire from the inside. On its outside, the green tire is heated via the designated shaping elements of the vulcanization mold. For example, heating plates or heating chambers are built into the heating press, which transfer heat to the shaping elements.

[0003] In the bladder, the energy of the hot steam is transferred into the bladder by condensation and from there to the tire. First, condensing water droplets form on the bladder's inner wall and then run down the bladder wall from top to bottom, like raindrops on a window pane. This causes a film of water to collect in the lower area of ​​the bladder and a "lake" to form in the area of ​​the lower sidewall. The water acts as an additional insulator, meaning the best heat transfer takes place in the upper, "top" area of ​​the bladder, to the tire areas located there, such as the upper bead area, the upper sidewall, and the upper shoulder area. Heat transfer is lower in the lower area of ​​the bladder, particularly in the lower sidewall, followed by the lower bead area and the lower shoulder area.As a result, certain tire areas are either too little or too strongly cross-linked during the intended vulcanization time, which can impair the quality and properties of the vulcanized tires. This applies particularly to the sidewalls and / or the tire beads. Furthermore, significant energy losses result from the transport of hot steam through supply lines into the interior of the bladder during the vulcanization process, as well as from the removal of the hot steam from the bladder after the vulcanization process.

[0004] EP 3 590 695 A1 addresses the problem of uneven temperature distributions with undesirably high or undesirably low temperatures in certain tire components that occurs with conventional interior heaters. To solve this problem, it is proposed that the mold carrier comprise at least one controllable heating unit designed to heat at least one lateral molding element.

[0005] The invention is based on the object of avoiding the aforementioned energy losses in a device of the type mentioned at the outset and of ensuring a uniform and, if possible, optimal temperature inside the heating bladder.

[0006] The stated object is achieved according to the invention in that the internal heating is formed by at least one infrared radiation element which is arranged on the section of the piston rod located inside the heating bladder when the tire is molded in.

[0007] According to the invention, the bladder is heated directly from the inside without the use of a heating medium, such as superheated steam, so that temperature differences between the upper and lower areas of the bladder are avoided, allowing these areas to be vulcanized evenly, ensuring a high-quality tire. By directly heating the interior of the bladder, energy losses, such as those typically associated with the introduction and discharge of superheated steam, are avoided.

[0008] A particularly simple and practical measure is to attach the infrared radiation element(s) to the section of the piston rod in a thermally insulated manner at a distance from this section.

[0009] In a preferred embodiment, a single infrared radiation element, which surrounds the section of the piston rod over, in particular, at least 50% of the length of the section, forms the internal heating. A particularly advantageous embodiment is one in which this infrared radiation element has multiple heating zones for emitting different heat energies. If different heating zones are present in the infrared radiation element, specific areas of the tire can be supplied with more or less heat energy.

[0010] In an alternative design, several infrared radiation elements are arranged consecutively along the piston rod section, forming the interior heating system. Each of these infrared radiation elements can emit a specific amount of radiant heat to optimize the interior heating system, thus also targeting specific tire areas with more or less heat energy.

[0011] Depending on the heat energy required for the interior heating system, various designs of the infrared radiation element(s) are particularly advantageous. Infrared radiation elements with circular, spiral, or ring-shaped designs are particularly suitable.

[0012] According to a further, equally advantageous embodiment, several rod-shaped infrared radiation elements running parallel to the section of the piston rod and along the section of the piston rod form the internal heating.

[0013] As mentioned above, the invention also relates to a method for vulcanizing a tire in a device designed according to one or more of claims 1 to 7. This method comprises the following sequential steps: - Inserting the tire into the opened vulcanization mold, - Inserting the bladder into the tire, - Closing the vulcanization mold, - filling the bladder with a gas, for example air, under pressure to apply the outer side of the tire to the inner sides of the mold parts of the vulcanization mold, - Commissioning of the outdoor and indoor heating, - Vulcanizing the tire, - Switching off the interior heating, - Opening the vulcanization mold and removing the tire, - Release the gas and remove the bladder.

[0014] This process is particularly advantageous when the bladder is filled with heated gas. This facilitates the molding of the tire into the mold and reduces the initial heat output from the infrared radiation elements.

[0015] Further features, advantages and details of the invention will now be described in more detail with reference to the drawing, which schematically illustrates exemplary embodiments. Fig. 1 a central sectional view of a tire vulcanization mold in the closed state with the tire inserted, Fig. 2 and Fig. 3 views of design variants of infrared radiation elements.

[0016] Fig. Figure 1 shows components of a heating press unit comprising a heating press 1 and a vulcanization mold 2 located therein. The heating press 1 comprises an upper external heater 3a and a lower external heater 3b. Components of the heating press 1 are movable in the vertical direction according to arrow P1 for opening and closing.

[0017] The vulcanization mold 2 has a segment ring, which is composed in the usual way of several, for example seven to fourteen, ring-shaped segment shoes 4, which hold profile segments 5 on the inside of the mold, which in turn hold those elements, such as sipes, webs and the like, for forming a profile in the tread of the Fig. 1 of the tire 10 already in the vulcanization mold 2. Further components of the vulcanization mold 2 are upper and lower sidewall shells 6a, 6b and upper and lower bead rings 7a, 7b. The central, in Fig. 1 vertical axis a of the vulcanization mold 2 coincides with the axis of rotation of the tire 10.

[0018] The segment shoes 4 are used to open and close the vulcanization mold 2 radially, in Fig. 1 in the direction of arrow P2. A locking ring 8 is in contact with the segment shoes 4 on the outside, which locking ring has an inclined inner surface which interacts with oppositely inclined outer surfaces of the segment shoes 4 of the segment ring in such a way that when the vulcanization mold is closed, the segment shoes 4 are moved in the direction of arrow P2 in Fig. 1 are moved together and thus close the segment ring.

[0019] Heating units are installed in the upper and lower external heaters 3a, 3b as well as in the locking ring 8, for example heatable heating plates or heating chambers 9, into which a heating medium, in particular water vapor, is introduced during vulcanization, so that in this way the external heater is formed, which supplies heat to the outside of the tire 10 via the segment shoes 4, the sidewall shells 6a, 6b and the bead rings 7a, 7b.

[0020] A heating bladder 11 is inserted into the still raw, unvulcanized tire 10. The heating bladder 11 is designed in a manner known per se and has a bladder part 11a coming into contact with the inside of the tire 10 and bladder feet 12a, 12b, wherein the one, in Fig. 1 upper bellows foot 12a between an upper bellows plate 13a and an upper bellows clamping ring 14a and the Fig. 1 lower bellows base 12b is held between a lower bellows plate 13b and a lower bellows clamping ring 14b. A piston rod 15, which is movable along the axis a of the vulcanization mold 2 and operatively connected to the upper bellows plate 13a, actuates the heating bladder 11 as it moves in and out of the tire 10. The heating bladder 11 is inserted into the tire 10 while the tire is inserted into the vulcanization mold 2, but before the vulcanization mold 2 is closed, so that the tire 10, together with the inserted heating bladder 11, is inserted into the still open vulcanization mold 2. Subsequently, the vulcanization mold 2 is closed and the heating bladder 11 is filled on the inside with a gas, such as air, possibly heated air, under pressure in such a way that the tire 10 rests with its outer side against the inner sides of the profile segments 5, the sidewall shells 6a, 6b and the bead rings 7a, 7b.

[0021] The piston rod 15 has a section 15a which extends inside the tire when the bladder 11 is in the tire and when the tire 10 is molded in. On this section 15a there is at least one infrared radiation element 16a ( Fig. 1), 16b ( Fig. 2) or 16c ( Fig. 3). Each infrared radiation element 16a, 16b, 16c is positioned at a short distance of, for example, 1 cm to approximately 5 cm from section 15a using not-shown, particularly thermally insulating spacers, which preferably simultaneously serve as fastening elements for the infrared radiation elements 16a, 16b, 16c to section 15a. Each infrared radiation element 16a, 16b, and 16c has contact elements for supplying electrical voltage in a known manner.

[0022] According to Fig. 1, the infrared radiation element 16a surrounds the section 15a of the piston rod 15 in a circular cylindrical shape (surface of a circular cylinder), in particular centrally and over at least 50% of the length of the section 15a of the piston rod 15. Alternatively, several infrared radiation elements 16a are arranged consecutively on the section 15a. In a further alternative, the one-piece infrared radiation element 16a has different heating zones. These alternative measures allow the heat radiation to be varied specifically across the interior of the heating bladder 11, for example, to set a lower heat radiation in the area of ​​the bead rings 7a, 7b.

[0023] At the Fig. In the embodiment shown in Figure 2, the infrared radiation element 16b has the shape of a spiral, which encircles the section 15a of the piston rod 15, in particular also over at least 50% of the length of the section 15a of the piston rod 15. Alternatively, this embodiment can also provide several spiral-shaped infrared radiation elements 16b, each extending around a partial area of ​​the section 15a.

[0024] A further embodiment of infrared radiation elements 16c shows Fig. 3. Around the section 15a of the piston rod 15, several, in particular a plurality of ring-shaped infrared radiation elements 16c are arranged at mutual distances.

[0025] In a further embodiment not shown separately, rod-shaped infrared radiation elements are provided which surround the piston rod 15 running along the section 15a and at a certain distance therefrom.

[0026] By means of an electronic control system, which receives values ​​from temperature measuring sensors, for example, which are arranged in or on the bellows clamping rings 14a, 14b and / or the bellows plates 13a, 13b, and / or measures the temperature profiles of the external heating, the electrical power of the infrared radiation elements 16a, 16b, 16c is adjusted and regulated accordingly in order to achieve the most advantageous and optimal temperature profile possible inside the tire to be vulcanized over the course of the vulcanization of the tire. List of reference symbols 1 heating press 2 Vulcanization mold 3a upper outdoor heating 3b lower outdoor heating 4 segment shoe 5 profile segment 6a upper side wall shell 6b lower side wall shell 7a Bead ring 7b Bead ring 8 locking ring 9 Heating chamber 10 tires 11 Heating bladder 11a Bellows part 12a upper bellows foot 12b lower bellows foot 13a upper bellows plate 13b lower bellows plate 14a upper bellows clamping ring 14b lower bellows clamping ring 15 Piston rod Section 15a 16a, 16b Infrared radiation element 16c Infrared radiation element a axis P1, P2 direction arrows QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 3 590 695 A1

[0004]

Claims

[1] Device for vulcanizing a vehicle tire with a heating press containing a vulcanization mold (2) and with an internal heater with a heating bladder (11) lying on the inside of the tire and an external heater which heats the outside of the vehicle tire (10) via components of the vulcanization mold (2), wherein the heating bladder (11) is held between an upper bladder plate (13a) and an upper bladder clamping ring (14a) and between a lower bladder plate (13b) and a lower bladder clamping ring (14b), and with a piston rod (15) operatively connected to the upper bellows plate (13a) and having a section (15a) located inside the bladder when the tire (10) is molded in, for actuating the retraction and extension of the bladder (11) into and out of the tire, characterized by , that the internal heating is formed by at least one infrared radiation element (16a, 16b, 16c) which is arranged on the section (15a) of the piston rod (15) located in the interior of the heating bladder when the tires are molded in. [2] Device according to claim 1, characterized by that the infrared radiation element (16a, 16b, 16c) or the infrared radiation elements are attached to the section (15a) of the piston rod (15) in a thermally insulated manner at a distance from the latter. [3] Device according to claim 1 or 2, characterized by that a single infrared radiation element (16a, 16b), which surrounds the section (15a) of the piston rod (15), in particular over at least 50% of the length of the section (15a), forms the internal heating. [4] Device according to claim 3, characterized by that the infrared radiation element (16a, 16b) has heating zones for emitting different heat energies. [5] Device according to claim 1 or 2, characterized by that several infrared radiation elements (16c) arranged successively on the section (15a) of the piston rod (15) form the internal heating. [6] Device according to one or more of claims 1 to 5, characterized by that the infrared radiation element (16a, 16b, 16c) or the infrared radiation elements is / are circular-cylindrical, spiral-shaped or ring-shaped. [7] Device according to claim 1 or 2, characterized by that several rod-shaped infrared radiation elements running parallel to and along the section (15a) of the piston rod (15) form the internal heating. [8] Method for vulcanizing a tire in a device designed according to one or more of claims 1 to 7, comprising the following successive steps: - Inserting the tire into the opened vulcanization mold, - Inserting the bladder (11) into the tire, - Closing the vulcanization mold (2), - filling the bladder (11) with a gas, for example air, under pressure to apply the outer side of the tire (10) to the inner sides of the molded parts of the vulcanization mold (2), - Commissioning of the outdoor and indoor heating, - Vulcanizing the tire, - Switching off the interior heating, - Opening the vulcanization mold (2) and removing the tire, - Release the gas and remove the bladder (11). [9] Method according to claim 8, characterized by that the heating bladder is filled with heated gas.

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