JP4837423B2 - Raw tire internal pressure device - Google Patents

Description

  The present invention relates to a green tire internal pressure device for holding the shape of a green tire by internal pressure.

  For example, in the preheating process of the raw tire before vulcanization molding, the temperature of the raw tire is raised to a preheating temperature close to the vulcanization start temperature. In this case, in order to preheat the raw tire uniformly, It is necessary to maintain the shape by applying pressure from

  As an example, in the bladderless type raw tire preheating device 1 disclosed in Patent Document 1, the raw tire 4 is sandwiched from both sides in the axial direction by two support plates 21 and 22, and an internal space formed by these The shape of the green tire 4 is maintained by supplying a pressurized medium to the tire.

In the raw tire preheating device 1, the raw tire 4 and the two support plates 21 and 22 are in contact with each other at the bead portions 4 c and 4 c of the raw tire 4. Then, by supplying the pressurized medium to the internal space, the bead portions 4c and 4c are pressed and adhered to the two support plates 21 and 22 from the inside, respectively, thereby leaking the pressurized medium from the internal space. It is preventing.
JP 2002-36244 A

  However, in the technique of Patent Document 1, when there is unevenness or deformation in the bead portion of the raw tire that comes into contact with the support plate, a gap is generated between the bead portion of the raw tire and the two support plates. The pressure medium supplied to the outside leaks to the outside, and the shape of the green tire is not maintained. Therefore, for example, in a preheating process, a green tire cannot be heated uniformly.

  Accordingly, an object of the present invention is to provide a bladderless green tire internal pressure device that can reliably prevent leakage of a pressure medium.

Means for Solving the Problems and Effects of the Invention

  In order to achieve the above object, the raw tire internal pressure device of the present invention has two support plates arranged on both sides of the raw tire in the axial direction of the raw tire, and the raw tire and the two The shape of the green tire is maintained by supplying a pressure medium to an internal space defined by two support plates. Moreover, it has a sealing member which expand | swells when a pressurization medium is supplied to an inside, and the said raw tire is supported by the said two support plates without gap by expansion | swelling of the said sealing member.

  According to this configuration, by supplying the pressurized medium to the inside, the seal member expands, and the gap between the raw tire and the support plate can be eliminated. A bladderless green tire internal pressure device that can prevent leakage is obtained.

  The two support plates each have a plate portion and a main body portion provided on one surface of the plate portion and having a circular outer periphery, and are concentric with the two main body portions and face each other. It is arranged, and the seal member may be formed in an annular shape and provided along the outer peripheral surface of the main body. According to this, leakage of the pressurized medium can be reliably prevented with a simple configuration.

  It is preferable that the sealing member is in contact with the green tire at the bead portion. According to this, since the contact area between the seal member and the green tire can be increased, a slight misalignment between the green tire and the support plate can be allowed.

  In a state where the green tire is not attached, the outer diameter of the seal member is smaller than the inner diameter of the opening of the green tire when no pressurized medium is supplied to the inside of the seal member. When the pressurized medium is supplied to the inside, it may be larger than the inner diameter of the opening of the green tire. According to this, since the sealing member is in close contact with the bead portion, the pressurized medium can be more reliably prevented from leaking. Furthermore, the green tire can be centered with respect to the two support plates by expanding the seal member.

  In a state where the pressurized medium is supplied to the inside of the seal member, the seal member contacts the bead portion from the inner space side, and the two support plates contact the raw tire from the outside in the axial direction. You may touch. According to this, since the raw tire is pressed against the two support plates by the expansion of the seal member, the raw tire is more reliably supported by the two support plates, and the leakage of the pressurized medium can be prevented more reliably.

Moreover, the raw tire internal pressurization apparatus of this invention can also prevent the preheating failure by the pressurization medium leak from the internal space of a raw tire by using in the preheating process of a raw tire.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  Here, an embodiment in which the raw tire internal pressure device according to the present invention is used in the preheating process of the raw tire will be described.

First, the whole structure of the raw tire internal pressurization apparatus which concerns on one Embodiment of this invention is demonstrated using FIG. FIG. 1 is a schematic cross-sectional view in the axial direction showing the configuration of a green tire internal pressure device according to this embodiment.

  The raw tire internal pressure device 1 according to the present embodiment supports the raw tire 4 and maintains the shape by pressurizing the raw tire from the inside, and further preheats the raw tire 4 by rotating it in the circumferential direction. It is. The raw tire is preheated after the tire is formed and before vulcanization.

  In the present embodiment, the raw tire 4 embedded with a metal member is used, and the raw tire 4 is formed by induction heating by forming a high-frequency high-frequency magnetic field with a preheating coil arranged along the metal member. Preheat.

  As shown in FIG. 1, the raw tire internal pressure device 1 includes two support plates 10 and 20 disposed on both sides of the raw tire 4 with respect to the raw tire 4 in the axial direction. The shape of the raw tire 4 is maintained by supplying a pressurized medium (compressed air) to the internal space 35 defined by the two support plates 10 and 20 and applying pressure thereto. This pressurized medium is sent from the pressurized medium supply source (not shown) to the internal space 35 of the raw tire 4 (in the direction of arrow X in the figure) through the pressurized tire pressure medium path 16.

  The support plate 10 has a rotary bearing portion 15 on the surface opposite to the internal space 35, and the support plate 20 has a rotation shaft 25 on the surface opposite to the internal space 35. . The fixed shaft 31 and the fixed bearing portion 32 are fixed to a fixed object (not shown). The rotary bearing portion 15 is rotatably supported with respect to the fixed shaft 31, and the rotary shaft 25 is rotatably supported by the fixed bearing portion 32. Further, the rotary bearing portion 15, the fixed shaft 31, the rotary shaft 25, and the fixed bearing portion 32 are arranged so that their rotation axes coincide.

  The two support plates 10 and 20 configured as described above can rotate in the circumferential direction of the raw tire 4 (in the direction of arrow Y in the figure) while supporting the raw tire 4. Further, the two support plates 10 and 20 are rotated by being powered by the rotation driving device 500.

  The two support plates 10 and 20 extend in the direction parallel to the rotation axis of the support plate from the circular plate portions 12 and 22 and the surfaces of the plate portions 12 and 22 on the inner space 35 side, respectively, and the outer periphery thereof It has cylindrical main body portions 13 and 23 formed in a circular shape, and the outer diameter of the main body portion 13 is equal to the outer diameter of the main body portion 23, and similarly, the outer diameter of the plate portion 12 and the plate portion 22. Is equal to the outer diameter of. The outer diameters of the main body portions 13 and 23 are smaller than the outer diameters of the plate portions 12 and 22, and smaller than the inner diameter of the opening formed by the bead portion of the raw tire 4. And the main-body parts 13 and 23 provided in these two support plates 10 and 20 are arrange | positioned mutually concentrically and the board parts 12 and 22 are made into the outer side. Further, the two support plates 10 and 20 are concentric with the rotary bearing portion 15 and the rotary shaft 25.

  On the outer peripheral surfaces 13a and 23a side of the main body portions 13 and 23, annular seal members 40a and 40b that expand when compressed air is supplied to the inside are along the outer peripheral surfaces 13a and 23a of the main body portions 13 and 23, respectively. Are attached to each. Here, the raw tire 4 comes into contact with the sealing members 40a and 40b at the bead portions 4c and 4c, and the raw tire 4 is supported by the two support plates 10 and 20 without a gap by the expansion of the sealing members 40a and 40b.

  Further, inner disk parts 14 and 24 are respectively provided on the opposite sides of the main body parts 13 and 23 from the plate parts 12 and 22, and the outer diameters of the inner disk parts 14 and 24 are the main body part 13. , 23 is larger than the outer diameter. Further, the axial length of the raw tire 4 of the sealing members 40a and 40b, the distance between the plate portion 12 and the inner disc portion 14, and the distance between the disc portion 22 and the inner disc portion 24 are as follows. Since they are substantially equal, the seal member 40a fits in a groove formed by the disc portion 12, the main body portion 13, and the inner disc portion 14, and the seal member 40b includes the plate portion 22, the main body portion 23, It fits in a groove formed by the inner disk portion 24. The seal members 40a and 40b are housed in a groove together with an annular base member and fixed to thereby exhibit internal airtightness.

  The raw tire internal pressure device 1 is formed with seal member pressure medium passages 11 and 21 for supplying a pressure medium (compressed air) to the seal members 40a and 40b, respectively. Then, a pressurized medium from a pressurized medium supply source (not shown) is sent into the seal members 40a and 40b. Further, the pressure medium passages 11 and 12 for the seal member are formed so as to be opened to the inside of the seal members 40 a and 40 b via the insides of the two support plates 10 and 20.

  Further, in the present embodiment, one sealing member pressure medium path 11, 21 is provided. FIG. 1 shows an axial section including the pressurizing medium paths 11 and 21 for the seal member, and the axial section does not always become a section including the pressurizing medium path.

  Next, the structure of the seal member 40a will be described with reference to FIGS. 2 and 3 are enlarged sectional views of a region corresponding to the broken line portion A in FIG.

  FIG. 2 shows a state in which the raw tire 4 is not attached to the raw tire internal pressure device 1, the solid line portion indicates a state in which no pressurized medium is supplied into the seal member 40a, and the broken line portion indicates a seal member. The pressurized medium is supplied to the inside of 40a and is expanded. Here, the partial raw tire 4 is shown for reference of the magnitude relationship, and is shown concentrically with the seal member 40a. Moreover, FIG. 3 has shown the state by which the raw tire 4 was attached to the raw tire internal pressurization apparatus 1, and compressed air was supplied to the inside of the sealing member 40a.

  Since the seal member 40a and the seal member 40b have the same structure, only the seal member 40a will be described here, and the description of the seal member 40b will be omitted.

  An annular base member 41 is fixed to the outer peripheral surface 13 a of the main body 13, and the seal member 40 a is attached to the outer peripheral surface 13 a using the base member 41. The pressurizing medium discharge port 11a at the tip of the pressurizing medium path 11 for the seal member passes through the through hole 13b formed in the main body 13 and is located inside the through hole 41a of the base member. The sealing member 40 a is a stretchable member that can seal the pressurized medium, and is locked to the base portion 41 by the locking portions 42 a and 42 b.

As shown in FIG. 2, the maximum outer diameter D of the seal member 40a when the pressurized medium is not supplied to the inside of the seal member 40a in a state where the raw tire 4 is not attached to the raw tire internal pressure device 1. _O is smaller than the inner diameter D _B of the opening of the green tire is formed by the bead portion 4c (solid line). Further, the maximum outer diameter D _P of the seal member 40a in a state where the inside to the pressurized medium of the seal member 40a is supplied is greater than the inner diameter D _B of the opening of the green tire (broken line).

  In addition, as shown in FIG. 3, in a state where the raw tire 4 is attached to the raw tire internal pressure device 1, when the pressure medium is supplied to the inside of the seal member 40a, the seal member 40a expands, While deforming so as to fit the shape of the bead portion 4c, the bead portion 4c is brought into close contact (contact with the surface).

  Further, in a state where the pressurized medium is supplied to the inside of the seal member 40a, the plate portion 12 of the support plate 10 contacts the raw tire 4 from the outside in the axial direction of the raw tire 4, and due to the expansion of the seal member 40a, The bead portion 4c is pressed from the inside of the raw tire (inside the internal space) to the plate portion 12 side of the support plate 10.

  Next, a structural example of the green tire 4 used in the present embodiment will be described. As shown in FIG. 4, the raw tire 4 has a tread portion 4a, sidewall portions 4b and 4b, and bead portions 4c and 4c, and a ring belt-shaped steel belt (metal member) on the tread portion 4a. 5 is embedded, and a ring wire-shaped bead wire (metal member) 6 is embedded in the bead portions 4c and 4c. The steel belt 5 is formed in a ring belt shape in which metal wires are arranged at an angle of 10 to 30 ° in the circumferential direction and are overlapped with each other. The steel belt 5 is sandwiched between a carcass assembly 7a having a rubber inner liner 7b attached to the inner peripheral surface and a rubber tread member 7c attached to the outer peripheral surface of the carcass assembly 7a. On both ends of the steel belt 5 in the width direction, rubber side wall members 7d are stuck between the carcass assemblies 7a. The bead wires 6 and 6 are formed in a wiring shape by twisting a plurality of metal wires. The bead wires 6 and 6 are provided at the bent portion of the carcass assembly 7a and are covered with a rubber side wall portion 7d and an inner liner 7b.

  Next, the preheating coils 510, 511, and 512 used for heating the raw tire 4 will be described. As shown in FIG. 1, the tread portion preheating coil 510 for the tread portion 4 a is disposed close to the outside of the raw tire 4 so as to follow the tread portion 4 a of the raw tire 4. Further, the partial preheating coils 511 and 512 for the bead portions 4c and 4c are arranged close to each other along the bead portions 4c and 4c. Then, high frequency power is supplied to preheating coils 510, 511, and 512 from a high frequency power source (not shown). And a high frequency magnetic field is formed along the longitudinal direction of the metal member (wire) embedded in the green tire, and the metal member is heated.

  Next, operation | movement of the raw tire internal pressurization apparatus 1 which concerns on this Embodiment is demonstrated. Here, the operation from the state in which the raw tire 4 is supported by the raw tire internal pressure device 1 will be described.

  First, a pressurized medium from a pressurized medium supply source (not shown) is supplied to the internal space 35 of the raw tire 4 through the raw tire pressure medium path 16 and the raw tire 4 is expanded to a predetermined shape (see FIG. 1). ), And rotational power is given by the rotation driving device 500, and the raw tire 4 rotates in the circumferential direction together with the two support plates 10 and 20.

  When the pressure medium is supplied into the seal members 40a and 40b when the raw tire 4 is supported, the seal members 40a and 40b expand and come into close contact with the bead portions 4c and 4c while being deformed. . For this reason, there is no gap between the raw tire 4 and the support plates 10 and 20, and leakage of the pressurized medium inside the raw tire 4 is prevented (see FIG. 3).

  At this time, the circular plate portions 12 and 22 of the two support plates 10 and 20 come into contact with the bead portions 4c and 4c of the raw tire 4 from the outside in the axial direction of the raw tire 4, respectively, and the sealing member 40a. 40b, the bead portions 4c and 4c are pressed against the plate portions 12 and 22 of the two support plates 10 and 20, respectively, so that the raw tire 4 is supported more reliably.

Further, when the raw tire 4 is not attached, the outer diameter D _O of the seal members 40a and 40b when the pressurized medium is not supplied to the inside of the seal members 40a and 40b is formed by the bead portions 4c and 4c. smaller than the inner diameter D _B of the opening of the green tire 4 is, also, the sealing member 40a, the sealing member 40a when the inside to the pressurizing medium 40b is supplied, the outer diameter D _P of 40b are of the raw tire 4 larger than the inner diameter D _B of the opening. Therefore, the adhesion between the sealing members 40a and 40b and the raw tire 4 when the sealing member is pressurized is improved, and the leakage of the pressurized medium inside the raw tire 4 is more reliably prevented. Furthermore, the raw tire 4 is automatically centered with respect to the two support plates 10 and 20 by expansion | swelling of the sealing members 40a and 40b.

  Then, high frequency power is supplied to preheating coils 510, 511, and 512 from a high frequency power source (not shown).

  The tread portion preheating coil 510 supplied with the high frequency power applies a high frequency magnetic field to the metallic member at a high magnetic flux density along the longitudinal direction of the metallic member (wire) embedded in the tread portion 4a. As a result, the steel belt 5 of the tread portion 4a is induction-heated. Further, the preheating coils 511 and 512 for the bead portion are high-frequency magnetic fields with respect to the metallic member along the longitudinal direction of the metallic member (wire) embedded in the upper and lower bead portions 4c and 4c. Is applied at a high magnetic flux density to inductively heat the bead wires 6 of the bead portions 4c and 4c. As described above, the tread portion 4a and the bead portions 4c and 4c can be heated to a preheating temperature close to the vulcanization start temperature.

  Further, since the raw tire 4 rotates in the circumferential direction of the raw tire 4, the tread portion coil 510 and the partial preheating coils 511 and 512 move relative to the raw tire 4. In addition, since the pressurized medium inside the raw tire 4 does not leak as described above, the shape of the raw tire 4 is maintained. As a result, the preheated portion of the raw tire 4 is induction-heated uniformly throughout.

  As described above, according to the raw tire internal pressure device 1 according to the present embodiment, the sealing members 40a and 40b are expanded by supplying a pressure medium to the inside, and the raw tire 4 and the support plates 10 and 20 are connected. Since the gap between them can be eliminated, leakage of the pressurized medium inside the raw tire 4 can be reliably prevented. Thereby, since the shape of the raw tire 4 is maintained, the raw tire 4 can be uniformly heated in the preheating step.

  The two support plates 10 and 20 have plate portions 12 and 22, and main body portions 13 and 23 that are provided on the plate portions 12 and 22 and have outer circumferences formed in a circular shape, respectively. , 23 concentrically and opposed to each other, and the seal members 40a, 40b are formed in an annular shape and are provided along the outer peripheral surfaces of the main body portions 13, 23. It is possible to reliably prevent the leakage of compressed air.

  Moreover, in this embodiment, since the sealing members 40a and 40b are in contact with the raw tire 4 at the bead portions 4c and 4c, the contact area between the sealing members 40a and 40b and the raw tire 4 can be increased. A slight misalignment between the raw tire 4 and the two support plates 10 and 20 can be allowed.

Further, in a state where the raw tire 4 is not attached, the outer diameter D _O of the seal members 40a and 40b when compressed air is not supplied to the inside of the seal members 40a and 40b is the inner diameter of the opening of the raw tire. D is smaller than _B. The seal member 40a, the sealing member 40a when the compressed air inside is supplied 40b, the maximum outer diameter _{D P} of 40b is larger than the inner diameter _{D B} of the opening of the raw tire. Thereby, since the sealing members 40a and 40b are in close contact with the bead portions 4c and 4c, leakage of the compressed air can be prevented more reliably. Furthermore, the raw tire 4 is automatically centered with respect to the two support plates 10 and 20 by expanding the sealing members 40a and 40b.

  Further, in a state where compressed air is supplied to the inside of the seal members 40a and 40b, the seal members 40a and 40b come into contact with the bead portions 4c and 4c from the inner space 35 side, and the two support plates 10 and 20 are The raw tire 4 comes into contact with the raw tire 4 from the outside in the axial direction, and the bead portions 4c and 4c are pressed against the disc portions 12 and 22 of the support plates 10 and 20 by the expansion of the seal members 40a and 40b, respectively. Therefore, the raw tire 4 is more reliably supported by the two support plates 10 and 20, and the leakage of compressed air can be further reliably prevented.

  Further, the seal member 40a fits in a groove formed by the plate portion 12, the main body portion 13, and the inner disk portion 14, and the seal member 40b includes the plate portion 22, the main body portion 23, and the inner disk portion. 24, the direction in which the seal members 40a and 40b expand is limited, and the contact between the seal members 40a and 40b and the bead portions 4c and 4c of the raw tire 4 is increased. In addition, leakage of compressed air can be prevented.

  Next, a modification of the raw tire internal pressure device 1 according to this embodiment will be described with reference to FIG. FIG. 5 is an enlarged cross-sectional view of the raw tire internal pressure device according to this modification in a region corresponding to the broken line portion A of FIG. In addition, in this modification, about the same part (211, 213, 214, 4, 4c) corresponding to the structural member of the raw tire internal pressurization apparatus 1 which concerns on said one Embodiment, said one Embodiment The reference numerals (11, 13, 14, 4, 4c) are sequentially matched to each other, and the description of the similar parts is omitted. Further, FIG. 5 shows a view of the support plate 10 side. However, since the support plate 20 side has the same structure as in the above embodiment, only the support plate 10 side will be described and supported here. Description of the plate 20 side is omitted. Moreover, since it is the same as that of said one Embodiment except the part (and the part by the side of the support plate 20 corresponding to this) represented in FIG. 5, description is abbreviate | omitted.

  In the support plate 210 of the raw tire internal pressure device 2 according to this modification, an annular protruding portion 212 a that protrudes inward in the axial direction (raw tire support side) is formed on the outermost periphery of the disc portion 212. . A groove is formed by the protruding portion 212a, the main body portion 213, and the plate portion 212. The seal member 240a is housed in the groove together with the annular base member, and is fixed so as to exhibit internal airtightness. Further, the pressure medium path 211 for the seal member communicates with the inside of the seal member 240a through the base member from the outside in the axial direction, not from the inside in the radial direction of the support plate. Even with such a configuration, the gap between the raw tire 4 and the support plate 210 can be eliminated, and thus leakage of the pressurized medium supplied into the raw tire 4 can be prevented.

  The raw tire was preheated using the raw tire internal pressure device 1 according to one embodiment of the present invention. In this embodiment, EPDM (ethylene / propylene rubber) having a hardness of 50 is used for the seal members 40a and 40b.

  As a result of preheating under the above conditions, the compressed air supplied to the inside of the raw tire did not leak to the outside, and the shape of the raw tire could be maintained. Further, uniform preheating with respect to the tread portion and the bead portion of the green tire was achieved.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims.

  For example, in the above embodiment, the seal member is attached to the support plate using the base member. However, the present invention is not limited to this configuration, and the seal member may be directly attached to the support plate.

  In the above embodiment, the sealing member is made of a stretchable material capable of sealing the pressurized medium. However, the present invention is not limited to this, and the cloth may be impregnated with rubber. In the above embodiment, EPDM having a hardness of 50 is used as the seal member, but the present invention is not limited to this. Moreover, a highly durable sealing member is obtained by using the EPDM having a hardness in the range of 40 to 70.

  In the above embodiment, the inner disk portion is provided. However, the present invention is not limited to this configuration, and the inner disk portion may not be provided.

  In the above embodiment, compressed air is exemplified as the pressurized medium. However, an inert gas may be used, and the pressurized medium supplied to the raw tire internal space may be heated air or Active gas or saturated steam may be used, and although not specified in the description of the above embodiment, a pressurized medium supply source to the internal space of the green tire, and a pressurized medium supply source to the inside of the two seal members May be separate or the same.

  Further, in the above embodiment, the raw tire is preheated by induction heating from the outside of the raw tire. However, the present invention is not limited to this form. For example, radiation heating using a heater may be used. It is not limited to heating. Moreover, you may preheat from the inside of a green tire by performing internal pressurization with a high temperature pressurization medium.

  Further, in the above-described embodiment, one pressurizing medium path 11, 12 for the seal member is provided. However, the present invention is not limited to this configuration, and any number may be provided. In the above-described embodiment, the pressurizing medium paths 11 and 12 for the seal member are arranged so as to be on the same cross section, but they need not be on the same cross section.

  Moreover, the raw tire internal pressurizing apparatus according to the present invention is not limited to use in the preheating step, and may be used for other uses for pressurizing the inside of the raw tire.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic axial sectional view showing a configuration of a raw tire internal pressure device according to an embodiment of the present invention. An enlarged sectional view of a region corresponding to the broken line portion A in FIG. 1 in a state where the raw tire is not attached to the raw tire internal pressure device, and a partial enlarged sectional view of the raw tire shown concentrically with the seal member in the drawing . The expanded sectional view of the area | region corresponded to the broken-line part A of FIG. 1 in the state by which the raw tire was attached to the raw tire internal pressurization apparatus. The disassembled perspective view which shows the internal structure of the raw tire of FIG. The expanded sectional view of the raw tire internal pressure apparatus which concerns on the modification of this embodiment in the area | region corresponded to the broken-line part A of FIG.

Explanation of symbols

1, 2 Raw tire internal pressure device 4 Raw tire 4c Bead portion 10, 20, 210 Support plate 35 Internal space 40a, 40b, 240a Seal member 12, 22, 212 Plate portion 13, 23, 213 Main body portion 13a, 23a surface

Claims (5)

For the axial direction of the green tire are disposed on both sides of the raw tire has two support plates you support the bead portion of the raw tire,
In a bladderless raw tire internal pressure device that maintains the shape of the raw tire by supplying a pressure medium directly to an internal space defined by the raw tire and the two support plates,
The two support plates each have a plate portion and a main body portion provided on one surface of the plate portion and having a circular outer periphery, and the two main body portions are concentrically opposed to each other. Is to be placed,
A seal member that expands when a pressurized medium is supplied to the inside;
The seal members are respectively provided along outer peripheral surfaces formed in an annular shape and in a circular shape of the two main body portions,
The raw tire internal pressure device, wherein the raw tire is supported on each of the two support plates without a gap by expansion of the seal member between the bead portion and the outer peripheral surface of the main body portion . The sealing member, the raw tire internal pressure device according to claim 1, characterized in that contact with the raw tire and the surface at the bead portion. In a state where the green tire is not attached, the outer diameter of the seal member is smaller than the inner diameter of the opening of the green tire when no pressurized medium is supplied to the inside of the seal member. The raw tire internal pressurizing device according to claim 2 , wherein when the pressurizing medium is supplied to the inside, the internal pressure of the raw tire is larger than an inner diameter of the opening of the raw tire. In a state where the pressurized medium is supplied to the inside of the seal member, the seal member contacts the bead portion from the inner space side, and the two support plates contact the raw tire from the outside in the axial direction. 4. The raw tire internal pressure device according to claim 3 , wherein the green tire internal pressure device is in contact. The raw tire internal pressurizing device according to any one of claims 1 to 4 , which is used in a preheating step of the raw tire.

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