Housing device for a tire mold, tire mold and vulcanization method

Abstract

The invention relates to a containment device (11) for a tyre mould (10) for vulcanizing a green tyre, a tyre mould and a method for vulcanizing a green tyre. The containment device has heating means (15) for heating the tyre mould, the containment device is composed of a plurality of mould segment containment seats (12) for receiving tyre mould segments (13) of the tyre mould, the mould segment containment seats each have an electric heating unit (16) of the heating means.

Description

Technical Field

[0001] This invention relates to a housing for a tire mold used for vulcanizing green tires, the housing having a heating device for heating the tire mold. The invention also relates to a tire mold for vulcanizing green tires, and a method for vulcanizing green tires using the tire mold. Background Technology

[0002] The aforementioned type of receiving device has been disclosed in the prior art. This device is typically a component of a tire mold for vulcanizing green tires. In addition to the receiving device, the tire mold generally includes multiple radially movable tire mold segments designed to cooperate with the receiving device. Specifically, when the tire mold is in the closed position, the tire mold segments are interconnected to form a mold ring for shaping the tire tread pattern; in this closed position, the tire mold segments are fixed together by the receiving device. The receiving device typically has a receiving frame designed to hold a heating fluid such as steam, which heats the tire mold, thereby vulcanizing the green tire placed within the tire mold. In tire manufacturing facilities, steam is readily available and inexpensive.

[0003] For example, German patent publication DE3631533 A1 describes a tire mold with such a receiving device. The receiving device is a component of the upper mold portion of the tire mold, and the tire mold segment is a component of the lower mold portion of the tire mold. Furthermore, it is known from the prior art that, in addition to the receiving device, the tire mold segment can also serve as a component of the upper mold portion of the tire mold.

[0004] Another type of containment device is found in German patent publication DE102022127194A1, in which a serpentine channel for the flow of water vapor is formed circumferentially within the containment device.

[0005] One drawback of existing containment devices is that the presence of channels for the flow of heating fluid within the device makes them difficult to manufacture. Furthermore, when the tire mold section is separated from the containment device and located in the lower mold section, the tire mold is heated indirectly. This means the containment device must be heated to the required operating temperature along with the tire mold, consuming a significant amount of thermal energy. Additionally, temperature control is challenging because the heat should be distributed relatively evenly along the circumference of the containment device or tire mold. However, steam heating often fails to achieve this uniform distribution. Moreover, steam heating limits the setting or adjustment of the desired operating temperature of the containment device to a relatively large tolerance range. Summary of the Invention

[0006] Therefore, the purpose of this invention is to provide a receiving device for a tire mold, a tire mold, and a method for vulcanizing a green tire. The above technical solution can achieve optimized heating of the tire mold.

[0007] The object of the present invention is achieved by the receiving device having the features of claim 1, the tire mold having the features of claim 18, and the method having the features of claim 20.

[0008] According to the present invention, a receiving device for a tire mold for vulcanizing green tires includes a heating device for heating the tire mold. The receiving device is composed of a plurality of mold segment receiving seats for receiving tire mold segments of the tire mold, and each mold segment receiving seat has an electric heating unit of the heating device.

[0009] According to the present invention, the heating device consists of multiple electric heating units, thus eliminating the need for a fully enclosed design of the housing, which would be necessary if the housing required circumferentially extending fluid channels. This design allows each mold segment housing for the tire mold to be directly heated by its corresponding electric heating unit, eliminating the need for partial separation between the heating device and the mold segment housing, thereby enabling direct heat transfer to the mold segment housing. Direct heating of the mold segment housing reduces heat loss, especially since it eliminates the need for temperature control of the entire housing. Furthermore, the operating temperature setting is not dependent on the steam temperature, and the operation is faster and more precise. Moreover, since the housing does not require a fully enclosed design, the overall structure can be designed to be more compact. Additionally, the elimination of process heat in the form of steam facilitates the transition of production to a CO2-neutralized energy supply model.

[0010] The electric heating unit of the module housing can be composed of at least one resistance heating element. This resistance heating element can be an electric tubular heating element, a heating cylinder, a heating coil, or a similar element. The resistance heating element can be disposed on the surface or inside the module housing, and multiple resistance heating elements can also be disposed on the module housing. This arrangement allows for the formation of different heating zones, which can be controlled independently of each other. Such resistance heating elements are inexpensive and can be easily adapted to the size and shape of the module housing.

[0011] The resistance heating element can be disposed on the outer side of the mold segment housing, away from the tire mold segment. This resistance heating element can then be easily installed on the mold segment housing. Furthermore, connecting the resistance heating element to a power source becomes very convenient. For example, an annular cable channel or cable guide structure can be provided on the housing to facilitate the corresponding connection of the resistance heating element.

[0012] The resistance heating element can be disposed within a groove formed on the outer side. This groove can be constructed in the form of a trench. The trench can be serpentine or spiral in shape, so that the heat generated by the resistance heating element is distributed as evenly as possible to the module housing. Alternatively, a plate-shaped resistance heating element can also be used and inserted into the corresponding groove.

[0013] The outer side is covered by a heat insulation plate of the module housing. This heat insulation plate can be made of a fire-resistant material with poor thermal conductivity. This plate can be used to reduce heat transfer to the environment, thereby reducing heat loss.

[0014] Each of the aforementioned mold segment receptacles may be equipped with a temperature sensor for the heating device, which may have a control device for controlling the temperature of the electric heating unit. The temperature sensor may be a resistance thermometer or a similar device. This allows for independent control of the electric heating unit and its temperature of each respective mold segment receptacle using a controller. Overall, this results in a more uniform temperature distribution around the circumference of the tire mold. Furthermore, any temperature variation in one or more mold segment receptacles can be responded to by individually controlling their temperatures. In general, this allows for more precise achievement of the desired operating temperature of the tire mold within a relatively small tolerance range.

[0015] Each of the aforementioned mold segment receiving seats is configured to move radially relative to each other, and the drive mechanism of the receiving device can move the mold segment receiving seats to the open and closed positions of the tire mold. When the tire mold is in the open position, a green tire can be inserted into the tire mold; when it is in the closed position, the green tire can be vulcanized; and when it is in the subsequent open position, it can be removed from the tire mold. The tire mold can be automatically opened and closed by means of the drive mechanism. After the tire mold segment is received on the mold segment receiving seat, the drive mechanism can cause the mold segment receiving seat to retract or separate along the radial direction of the tire mold or tire, thereby forming a mold ring.

[0016] The drive unit is fixed to the outside of the drive unit via at least one intermediate layer element. There is no direct connection between the drive unit and the mold segment housing. The intermediate layer element can be designed as, for example, a plate-like structure. If the drive unit is connected to the mold segment housing by, for example, one or more support plates, these support plates can be fixed to the outside via the intermediate layer element. The intermediate layer element can be made of, for example, stainless steel. Stainless steel has a relatively low thermal conductivity compared to structural steel, but possesses high compressive strength. This creates a robust connection structure between the drive unit and the mold segment housing, which provides at least partial thermal insulation, effectively reducing heat loss from the mold segment housing through the drive unit. If a heat insulation plate is also attached to the outside of the mold segment housing, grooves or through-holes can be provided in the heat insulation plate to house the intermediate layer element. Alternatively, the heat insulation plate can be designed as an integral, pressure-resistant structure.

[0017] The receiving device may have an upper receiving plate and a parallel lower receiving plate, which may be disposed between the pressure heads of a press. Force can then be applied to the upper and lower receiving plates by the press to bring the tire mold into a closed position. The tire mold can be brought into an open position by moving the pressure heads of the press in the opposite direction. For example, the upper and / or lower receiving plates may be fixed to the corresponding pressure heads of the press.

[0018] Each of the aforementioned module receiving seats is connected to the upper receiving plate or the lower receiving plate via a cylindrical joint drive mechanism of the drive device. By means of the cylindrical joint drive mechanism, the force applied axially by the press head along the receiving device can be converted into a force acting laterally or radially along the receiving device, thereby enabling radial movement of the module receiving seat using the drive device. Furthermore, the cylindrical joint drive mechanism is simple and inexpensive to manufacture.

[0019] The upper or lower receiving plate may consist of a guide plate and a drive ring, the drive ring being axially movable relative to the guide plate. Preferably, the drive ring radially surrounds the guide plate at least partially, and more preferably completely. However, in principle, the drive ring may also be positioned above the guide plate, or above the guide plate of the lower receiving plate. By means of the drive ring of the drive device, the die segment receiving seat can be moved, or the force applied by the pressure head can be transmitted to the die segment receiving seat.

[0020] The cylindrical joint drive mechanism can consist of a first cylindrical joint, a second cylindrical joint, and a connecting rod connecting the cylindrical joints. The first cylindrical joint can be mounted on the corresponding mold segment receiving seat, and the second cylindrical joint can be mounted on the drive ring. Each cylindrical joint can be connected to the connecting rod via a shaft, which can be designed as a bolt or formed by the connecting rod or the joint body of the corresponding cylindrical joint. However, in principle, the cylindrical joint and the connecting rod can also be connected via, for example, a ball joint or other similar structure. Furthermore, the connecting rod can be designed as a rod-like structure to transmit tension and pressure. In a particularly simple embodiment, the first cylindrical joint can be connected to the mold segment receiving seat by form fit, force fit, or material fit, or it can also be formed by the mold segment receiving seat itself. The second cylindrical joint can also be fixed to the drive ring by form fit, force fit, or material fit, or it can also be formed by the drive ring itself. The axial movement of the drive ring relative to the guide plate causes radial movement of the mold segment receiving seat via the cylindrical joint drive mechanism. The drive ring can also be designed so that the closing force of the tire mold can be adjusted via the drive ring. Therefore, the next step is simply to limit or extend the axial movement of the drive ring relative to the guide plate.

[0021] The cylindrical joint can be disposed on the outer side of the corresponding mold segment receiving seat opposite to the tire mold segment, and the guide unit of the drive device can guide the mold segment receiving seat radially on the guide plate. For example, a radially extending groove can be formed on the guide plate to guide the mold segment receiving seat. For example, the groove can be designed as a so-called T-shaped groove, into which a correspondingly designed slider on the mold segment receiving seat can be inserted. The slider can be easily fixed to the mold segment receiving seat with screws, thereby facilitating the assembly and disassembly of the mold segment receiving seat on the guide plate.

[0022] Each of the mold segment receiving seats can be connected to the upper or lower receiving plate via a clamping drive mechanism of the drive unit. For example, the clamping drive mechanism can be constructed from an inclined plane or other similar structure. In this case, axial movement can be converted into radial clamping movement. This clamping drive mechanism design is particularly simple and can reliably open and close the tire mold.

[0023] The upper or lower receiving plate may consist of a guide plate and a conical clamping ring, the conical clamping ring being axially movable relative to the guide plate. The guiding unit of the drive device can radially guide the die segment receiving seat on the guide plate, the die segment receiving seat being connected to the clamping ring via a transverse guide rail formed on the inner conical surface of the clamping ring. With the aid of the conical clamping ring, the force applied by the press head along the axial direction of the receiving device can be converted into a force acting in the transverse or radial direction of the receiving device, thereby enabling radial movement of the die segment receiving seat using the drive device. In this process, the conical clamping ring preferably at least partially, and preferably completely, radially encloses the guide plate. With the aid of the conical clamping ring, the die segment receiving seat can be moved or the force generated by the press head can be transmitted to the die segment receiving seat. Subsequently, the die segment receiving seat is radially guided along the guide plate, for example, as in the cylindrical joint drive mechanism described above. Furthermore, a transverse guide rail may also be formed on the inner conical surface of the clamping ring, allowing the die segment receiving seat to move relative to the clamping ring in the transverse direction along the inner conical surface. A transverse guide rail can be formed between the inner conical surface and the outer side of the module housing. The transverse guide rail can be a linear guide rail or a similar structure. Axial movement of the clamping ring causes movement of the module housing on the transverse guide rail, while the module housing simultaneously moves radially on the guide plate. This allows for highly precise positioning of the module housing during opening and closing.

[0024] The receiving device may have 6 to 23 module receiving seats. This receiving device can be used to manufacture tires for various vehicles, such as bicycles, cars, trucks, buses, airplanes, and even other types of tires. The number of module receiving seats may vary depending on the size of the tire to be manufactured. The number of module receiving seats specified herein is in the range of 6 to 23, and all numbers within this range will be mentioned individually.

[0025] The housing has a heat shield that partially encloses it. The heat shield protects the tire mold operators from heat radiation and prevents unnecessary physical contact between them and the tire mold. Furthermore, it reduces heat dissipation from the tire mold.

[0026] The tire mold for vulcanizing green tires according to the present invention includes a receiving device according to the present invention.

[0027] The tire mold may include multiple radially movable tire mold segments, which are configured to cooperate with the receiving device such that, when the tire mold is in a closed position, the tire mold segments can be interconnected to form a mold ring for forming the tire tread, and in the closed position, the tire mold segments can be fixed as a single unit by the receiving device, or can cooperate with each other to form a mold ring for forming the tire tread. The tread may be a treadless tread or a treaded tread.

[0028] Other advantageous embodiments of the tire mold can be derived from the features described in the dependent claims referencing claim 1.

[0029] In a method for vulcanizing a green tire using a tire mold according to the present invention, the tire mold is heated by a heating device of a receiving device, the receiving device comprising a plurality of mold segment receiving seats for receiving tire mold segments of the tire mold, and the tire mold is heated by an electric heating unit of the heating device through each mold segment receiving seat. Regarding the advantages of the method described in the present invention, reference can be made to the description of the advantages of the receiving device according to the present invention.

[0030] Other advantageous embodiments of the method can be derived from the features described in the dependent claims of claim 1. Attached Figure Description

[0031] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings.

[0032] Figure 1 A perspective view of a tire mold is shown;

[0033] Figure 2 A top view of a tire mold is shown; Figure 3 It shows Figure 2 A cross-sectional view along line III-III, at which point the tire mold is in the closed position; Figure 4 It shows Figure 2 A partial sectional view along line III-III, showing the tire mold in the open position; Figure 5 It shows Figure 2 A cross-sectional view along line VV; Figure 6 A perspective view of a module housing is shown; Figure 7 It shows Figure 6 Exploded view of the middle module housing; Figure 8 It shows Figure 6 Front view of the middle module housing; Figure 9 It shows Figure 8 A cross-sectional view along line IX-IX; Figure 10 It shows Figure 6 Top view of the middle module housing; Figure 11 A perspective view of another tire mold is shown; Figure 12 A top view of another tire mold is shown; Figure 13 It shows Figure 12 A cross-sectional view along line XIII-XIII, at which point another tire mold is in the closed position; Figure 14 It shows Figure 12 A partial sectional view along line XIII-XIII, showing another tire mold in the open position; Figure 15 It shows Figure 12 A cross-sectional view along the XV-XV line; Figure 16 A perspective view of another type of module housing is shown; Figure 17 It shows Figure 16 An exploded view of another type of module housing. Detailed Implementation

[0034] Figures 1 to 10 A tire mold 10 is shown from different perspectives, comprising a receiving device 11 and a mold segment receiving seat 12 of the receiving device 11. The tire mold 10, used for vulcanizing green tires (not shown in detail), includes a tire mold segment 13 and a tire mold housing 14, both disposed on the receiving device 11 and shown only schematically in the figures. Specifically, the tire mold segment 13 is used to form the tire tread and is fixedly connected to the mold segment receiving seat 12, allowing radial movement. The tire mold housing 14 is used to form the tire sidewalls and is fixed to the receiving device 11 for axial movement relative to each other.

[0035] The receiving device 11 is equipped with a heating device 15 for heating the tire mold 10, and each mold segment receiving seat 12 has an electric heating unit 16 of the heating device 15. The heating device 15 includes a control device (not shown in detail here) for controlling the temperature of the electric heating unit 16. The receiving device has a first upper receiving plate 17 and a first lower receiving plate 18, both of which can be disposed between the press heads of a press (not shown here). The tire mold housing 14 is fixed to the first upper receiving plate 17 and the first lower receiving plate 18. Furthermore, in the embodiment shown here, the receiving device 11 has eight mold segment receiving seats 12, each mold segment receiving seat accommodating one tire mold segment 13.

[0036] like Figures 6 to 10 As seen in the combined view, the module housing 12 is composed of a shell-shaped housing body 19, on the outer side 20 of which grooves 22 are provided in the form of recesses 21. The resistance heating element 23 of the electric heating unit 16 is embedded in the serpentine grooves 22. The outer side 20 is also covered with a heat insulation plate 24, on which grooves 25 are provided, into which intermediate layer elements 26 made of stainless steel are inserted. The support plate 27 of the first cylindrical joint 28 is securely connected to the intermediate layer elements 26 and the housing body 19 by screws. In addition, an electrical connection wire 29 is provided for the resistance heating element 23, which is laid through a portion of the metal flexible hose 30. In addition, a slider 31 is fixed on the housing body 19. In order to control the temperature of the housing body 19 using the heating device 15, the electric heating unit 16 includes a temperature sensor 32, which is inserted into a drilled hole 33 on the housing body 19.

[0037] Figures 3 to 5 A cross-sectional view of the tire mold 10 in the open position 34 and the closed position 35 is shown. In this embodiment, the first lower receiving plate 18 is provided on the press head of the press. The first upper receiving plate 17 is composed of a guide plate 36 and a drive ring 37. The first upper receiving plate 17 is also provided on another opposing press head of the press, by means of which the drive ring 37 can be moved axially relative to the guide plate 36. Each mold segment receiving seat 12 is connected to the drive ring 37 via a cylindrical joint drive mechanism 38. Thus, the mold segment receiving seat 12 and the drive ring 37 together constitute the drive device 39 of the receiving device 11. The cylindrical joint drive mechanism 38 is composed of a first cylindrical joint 28, a second cylindrical joint 40 provided on the drive ring 37, and a connecting rod 41 connecting the first cylindrical joint 28 and the second cylindrical joint 40. Here, the connecting rod 41 is composed of a rod 42, which is pivotally mounted on the shaft 43 of the first cylindrical joint 28 and the shaft 44 of the second cylindrical joint 40.

[0038] Each mold segment receiving seat 12 is provided with a radial guide structure 45 by the guide plate 36. The mold segment receiving seat 12 can move radially along the guide structure relative to the central axis 46 of the tire mold 10. Each radial guide structure 45 is composed of a guide groove 47 into which the slider 31 is inserted. When the drive ring 37 moves axially relative to the central axis 46 and the guide plate 36, if the drive ring 37 separates from the first lower receiving plate 18, the mold segment receiving seat 12 will move radially to the open position 34. If the drive ring 37 and the first lower receiving plate 18 move closer to each other, the mold segment receiving seat 12 will move radially towards the central axis 46, thereby turning to the closed position 35.

[0039] All electrical connection lines 29 converge in a cable trough 49 formed on the drive ring 37 and having a cover plate 48, thereby establishing a central electrical connection (not shown) with the control device of the housing device 11.

[0040] Figures 11 to 17 The tire mold 50 is shown from different perspectives. The tire mold is equipped with a receiving device 51 and mold segment receiving seats 52 of the receiving device 51. The receiving device 51 has a heating device 53 for heating the tire mold 50, and each mold segment receiving seat 52 has an electric heating unit 54 of the heating device 53. Figures 1 to 10 Unlike the tire mold shown, the second upper receiving plate 55 here consists of a guide plate 56 and a conical clamping ring 57. Each mold segment receiving seat 52 is movably connected to the inner conical surface 59 of the conical clamping ring 57 via a transverse guide rail 58. Each transverse guide rail 58 is mounted on the corresponding mold segment receiving seat 52 via a support plate 60. The conical clamping ring 57, together with the transverse guide rail 58 and the mold segment receiving seat 52, constitutes the clamping drive mechanism 61 of the drive device 62 of the tire mold 50.

[0041] Furthermore, the guide plate 56 is formed with a radial guide structure 63 for each mold segment receiving seat 52. When the tapered clamping ring 57 moves axially relative to the central axis 64 of the tire mold 50 and the guide plate 56, if the tapered clamping ring 57 separates from the second lower receiving plate 65, the mold segment receiving seat 52 will move radially to the open position 66. If the tapered clamping ring 57 and the second lower receiving plate 65 move closer to each other, the mold segment receiving seat 52 will move radially towards the central axis 64, thereby switching the mold to the closed position 67.

Claims

1. A receiving device (11, 51) for a tire mold (10, 50) for vulcanizing green tires, said receiving device having a heating device (15, 53) for heating the tire mold, characterized in that, The receiving device consists of multiple mold segment receiving seats (12, 52), which are used to receive the tire mold segment (13) of the tire mold. Each mold segment receiving seat has an electric heating unit (16, 54) of the heating device.

2. The receiving device according to claim 1, characterized in that, The electric heating unit (16, 54) of the module housing (12, 52) is composed of at least one resistance heating element (23).

3. The receiving device according to claim 2, characterized in that, The resistance heating element (23) is disposed on the outer side (20) of the mold section receiving seat (12, 52) away from the tire mold section (13).

4. The receiving device according to claim 3, characterized in that, The resistance heating element (23) is disposed in a groove (21) opened on the outer side (20).

5. The receiving device according to claim 3, characterized in that, The outer side (20) is covered by the heat insulation plate (24) of the module receiving seat (12, 52).

6. The receiving device according to claim 1, characterized in that, Each of the module housings (12, 52) is provided with a temperature sensor (32) for the heating device (15, 53), and the heating device has a control device for controlling the temperature of the electric heating unit (16, 54).

7. The receiving device according to claim 1, characterized in that, The module receiving seats (12, 52) are configured to move radially relative to each other, and the drive device (39, 62) of the receiving device (11, 51) is capable of moving the module receiving seats to the open position (34, 66) and closed position (35, 67) of the tire mold (10, 50).

8. The receiving device according to claim 7, characterized in that, The drive unit (39, 62) is fixed to the outside (20) of the module housing (12, 52) by at least one intermediate layer element (26).

9. The receiving device according to claim 7, characterized in that, The receiving device (11, 51) has a first upper receiving plate (17) and a second upper receiving plate (55) and a parallel first lower receiving plate (18) and a second lower receiving plate (65), all of which can be arranged between the press heads of the press.

10. The receiving device according to claim 9, characterized in that, Each of the module receiving seats (12) is connected to the first upper receiving plate (17) or the first lower receiving plate (18) via the cylindrical joint drive mechanism (38) of the drive device (39).

11. The receiving device according to claim 10, characterized in that, The first upper receiving plate (17) or the first lower receiving plate (18) is composed of a guide plate (36) and a drive ring (37), the drive ring (37) being axially movable relative to the guide plate.

12. The receiving device according to claim 11, characterized in that, The cylindrical joint drive mechanism (38) consists of a first cylindrical joint (28), a second cylindrical joint (40), and a connecting rod (41) connecting the cylindrical joints. The first cylindrical joint (28) is disposed on the module receiving seat (12), and the second cylindrical joint (40) is disposed on the drive ring (37).

13. The receiving device according to claim 12, characterized in that, The first cylindrical joint (28) is disposed on the outer side (20) of the mold segment receiving seat (12) away from the tire mold segment (13), and the guide unit of the drive device (39) radially guides the mold segment receiving seat on the guide plate (36).

14. The receiving device according to claim 9, characterized in that, The module receiving seats (52) are all connected to the second upper receiving plate (55) or the second lower receiving plate (65) via the clamping drive mechanism (61) of the drive device (62).

15. The receiving device according to claim 14, characterized in that, The second upper receiving plate (55) or the second lower receiving plate (65) is composed of a guide plate (56) and a conical clamping ring (57), which is axially movable relative to the guide plate; the guide unit of the drive device (62) radially guides the module receiving seat on the guide plate, and the module receiving seat (52) is connected to the clamping ring via a transverse guide rail (58) formed on the inner conical surface (59) of the clamping ring.

16. The receiving device according to claim 1, characterized in that, The receiving device (11, 51) has 6 to 23 module receiving seats (12, 52).

17. The receiving device according to claim 1, characterized in that, The receiving device (11, 51) has a heat insulation cover that partially encloses the receiving device.

18. A tire mold (10, 50) for vulcanizing green tires, characterized in that, The tire mold includes a receiving device (11, 51) according to any one of claims 1 to 17.

19. The tire mold according to claim 18, characterized in that, The tire mold (10, 50) includes a plurality of radially movable tire mold segments (13), which are configured to cooperate with the receiving device (11, 51) such that when the tire mold is in the closed position (35, 67), the tire mold segments can be connected to each other to form a mold ring for forming the tire tread, and in the closed position, the tire mold segments are fixed as one piece by the receiving device.

20. A method for vulcanizing a green tire using tire molds (10, 50), wherein the tire molds (10, 50) are heated by heating devices (15, 53) of a receiving device (11, 51), characterized in that, The receiving device consists of multiple mold segment receiving seats (12, 52), which are used to receive the tire mold segment (13) of the tire mold. The tire mold is heated by the electric heating unit (16, 54) of the heating device through each mold segment receiving seat.

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