JP2019119107A - Tire molding apparatus - Google Patents

Abstract

To provide a tire molding apparatus capable of preventing a bead part from excessively sticking to a bead lock when shaping, and capable of rapidly taking a molded green tire out of the bead lock without causing damage.SOLUTION: A tire molding apparatus for holding a green case 1 formed by winding a bead portion 4 provided with a bead filler 3B on the outer peripheral side of an annular bead core 3A with an end portion of a cylindrical carcass in the width direction is provided with a bead lock 16 for coming into contact with the inner side surface of the bead portion 4 in the radial direction to hold the green case 1. The bead lock 16 has a first region configuring a part of contact surface with the bead portion 4 formed with a material more excellent in mold release property than that in a second region configuring the remainder.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a tire molding apparatus.

  As a method of manufacturing a pneumatic tire, there is a method of forming a green tire by combining a green case molded by a primary molding machine with a tread ring by a secondary molding machine.

  Specifically, after the inner liner and the carcass ply are wound around the outer periphery of the forming drum of the primary forming machine and provided in a cylindrical shape, annular bead cores and bead fillers are extrapolated to both axial ends of the cylindrical carcass ply. . Then, the bead core is folded back so as to wind in the bead core at both ends in the axial direction of the carcass ply, and then sidewall rubbers are laminated to form a green case.

  The obtained green case is held in a secondary molding machine by bead lock from the radial inner side of the bead portion, and the axial central portion is expanded and shaped in a toroid shape to form a tread ring made of a belt and tread rubber Bonding to form a green tire. And a pneumatic tire is obtained by vulcanizing and molding the obtained green tire in a mold (patent documents 1-3).

Japanese Patent Application Laid-Open No. 2004-9457 Unexamined-Japanese-Patent No. 2001-293793 Unexamined-Japanese-Patent No. 9-12330

  In a tire molding machine as a secondary molding machine that performs shaping as described above, the bead portion adheres excessively to the bead lock at the time of shaping, making it difficult to take out the formed green tire, resulting in deterioration of workability or taking out The bead may be damaged.

  The tire molding apparatus according to the present invention is a tire molding apparatus for holding a green case in which a bead portion provided with a bead filler on the outer peripheral side of an annular bead core is wound at the end in the width direction of a cylindrical carcass. The bead lock includes a bead lock that holds the green case in contact with the radially inner side surface, and in the bead lock, a first region that constitutes a part of the contact surface with the bead portion is a second region that constitutes the remaining portion. It is formed of a material having excellent releasability.

  In a preferred aspect of the present invention, the first region may be formed of a resin, and the second region may be formed of a metal.

  In another preferred aspect of the present invention, the first region may abut on the axially inner side of the bead portion.

  In another preferred aspect of the present invention, the second region may abut on the inner side in the tire radial direction of the bead portion.

  In another preferable aspect of the present invention, the bead lock is provided in a base formed of metal constituting the two regions, a resin storage portion provided in the base, and the first region provided in the resin storage portion. And the resin member may be 1 mm or more and 3 mm or less in thickness.

  According to the present embodiment, it is possible to prevent the bead portion from being in intimate contact with the bead lock at the time of shaping, and it is possible to quickly take out the molded green tire from the bead lock without damaging it.

1 is a half sectional view of a tire forming apparatus according to a first embodiment. The principal part enlarged view of FIG. The principal part expanded sectional view of the state which the tire shaping | molding apparatus of FIG. 1 hold | maintained the bead part. The expanded sectional view of the tire molding device concerning a 2nd embodiment.

First Embodiment
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

  Although the pneumatic tire according to the present embodiment is not shown, it is provided between a pair of left and right bead portions, a pair of sidewall portions extending outward from the bead portion in the tire radial direction, and the left and right sidewall portions. And a tread portion. In the bead portion, a bead member formed of an annular bead core and a hard rubber bead filler provided on the outer peripheral side thereof is embedded.

  In the tire, a carcass ply extending between a pair of bead portions is embedded, and the carcass ply is engaged at both ends in the bead portion from the tread portion through the sidewall portion, and is configured by at least one ply There is. The carcass ply is formed by rubber-coating a plurality of carcass cords arranged in parallel, and both ends of the carcass ply are folded and locked from the inside to the outside of the bead member at the bead portion. The bead portion is provided with chafers around the turn-up portion of such carcass ply.

  A belt made of a belt ply is provided on the outer peripheral side of the carcass ply in the tread portion to reinforce the tread portion. On the inside of the carcass ply, an inner liner for air pressure retention is provided over the entire tire inner surface.

  In order to manufacture this tire, first, these members are cylindrically provided on the outer periphery of a forming drum of a primary forming machine (not shown) in the order of an inner liner, a chafer and a carcass ply, and both widthwise end portions of the carcass ply are provided. Attach an annular bead member to the outer peripheral surface of Then, after both end portions in the width direction of the carcass ply are folded back so as to wind the bead member, sidewall rubber is disposed at a predetermined position. As a result, as shown in FIG. 1, the green case 1 is formed in which the bead portion 4 including the annular bead core 3A is provided at both ends of the cylindrical carcass ply 2. The green case 1 is provided with a bead member 3 including an annular bead core 3A and a bead filler 3B provided on the outer peripheral side thereof in the bead portion 4 and has a structure in which the bead member 3 is wound at both ends of the carcass ply 2 . The green case 1 further includes an inner liner 5, chafers 6, and sidewall rubbers 7.

  The green case 1 molded in the primary molding machine is held by a tire molding device 10 corresponding to a secondary molding machine.

  Specifically, as shown in FIG. 1, the tire molding device 10 includes a shaft 12 extending along the axial direction L of the green case 1 and a pair of left and right shaping drums 14 rotatably provided around the shaft 12, 14 and a pair of left and right bead locks 16 and 16 provided on the outer periphery of each of the shaping drums 14 and 14.

  The pair of shaping drums 14 and 14 are spaced apart in the axial direction L, and can be rotationally driven about the axis of the shaft 12 by a driving unit (not shown) and can be moved close to and away from each other. It is configured to be movable.

  The bead lock 16 is a member that holds the green case 1 in contact with the bead portion 4 from the inside in the tire radial direction. The bead lock 16 is attached to the outer peripheral surface of the shaping drum 14, is divided into a plurality of segments in the circumferential direction, and is provided to be able to expand and contract in the radial direction R. Therefore, the bead lock 16 is provided so as to be movable in the axial direction L, and is provided so as to be capable of expanding and contracting in the radial direction R, and the diameter is expanded and contracted radially inward of the bead portion 4.

  The bead lock 16 includes a base 17 formed of a metal material such as aluminum or stainless steel into a predetermined shape. The base portion 17 has a recess 18 which is opened radially outward and receives the bead portion 4 from the radially inner side. The recess 18 is in the form of a recess extending along the circumferential direction that is recessed radially inward on the radially outer surface facing the bead portion 4, and the radially inner end portion of the bead portion 4 is formed by the recess 18. Receive and hold the green case 1.

  As shown in FIG. 1 and FIG. 2, the recess 18 has a bottom surface 18A parallel to the axial direction L with which the radially inner side surface 4A of the bead portion 4 abuts, and radially outward from the axial inner end of the bottom surface 18A. An axially inner side wall 18B is provided, and an axially outer side wall 18C is provided radially outward from the axially outer end of the bottom surface 18A.

  The axially inner side wall 18 B of the recess 18 forms a curved surface having a circular arc-like cross section along the shape of the axially inner side surface 4 B of the bead portion 4. The axially outer side wall 18C of the recess 18 has an inclined surface which is inclined outward in the axial direction as it goes radially outward.

  As shown in FIG. 3, when the recess 18 holds the bead portion 4, the axially inner side surface 4 B of the bead portion 4 contacts the axially inner side wall 18 B of the recess 18, and the radially inner side surface 4 A of the bead portion 4 is the recess 18. Of the bead portion 4 (or the edge portion between the radially inner side surface 4A of the bead portion 4 and the axially outer side surface 4C) contacts the axially outer side wall 18C of the recess 18 Do. That is, the axially inner side wall 18 B, the bottom surface 18 A, and the axially outer side wall 18 C of the recess 18 constitute a contact surface in contact with the bead portion 4.

  In the tire molding apparatus 10 having such a configuration, the axially inner side wall 18B and the axially outer side of the axially inner side wall 18B, the bottom surface 18A and the axially outer side wall 18C of the recess 18 constituting the contact surface with the bead portion 4 The wall 18C is formed of a material (hereinafter sometimes referred to as a good releasable material) that is superior in releasability to the bottom surface 18A.

  In the present embodiment, the metal material constituting the base portion 17 is exposed on the bottom surface 18A of the recess 18, and the coatings 22 and 24 made of a good releasability material are formed on the surfaces of the axial inner wall 18B and the axial outer wall 18C. It is formed. Specific examples of the material having good releasability include fluorine resins such as polytetrafluoroethylene (PTFE), perfluoroalkoxy fluorine resin (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and silicone resin And resins such as nylon resin, silicone resin and polyurethane resin.

  The tire molding apparatus 10 includes a fluid supply unit (not shown) for supplying a fluid such as gas in the green case 1 and is configured to expand the green case 1 in a toroidal shape by the fluid supplied from the fluid supply unit. It is done.

  The tire molding apparatus 10 further includes holding means (not shown) for holding a cylindrical tread ring (not shown) in which the belt and the tread rubber are stacked on the radially outer side of the green case 1.

  In order to form a green tire using the tire forming apparatus 10, first, the green case 1 is transferred from the primary forming machine to the tire forming apparatus 10. Specifically, as shown in FIGS. 1 and 2, after the green case 1 is disposed over the outer peripheral portions of the pair of shaping drums 14, the bead lock 16 is radially outward from the inside in the radial direction of the bead portion 4. Move to R1 (ie, increase the diameter of the bead lock 16). As a result, the bead portion 4 of the green case 1 is fitted into the recess 18 provided in the bead lock 16 and the green case 1 is held by the bead lock 16 (see FIG. 3).

  At that time, since the coatings 22 and 24 made of a material that is more excellent in releasability than the bottom surface 18A are provided on the surfaces of the axially inner wall 18B and the axially outer wall 18C of the recess 18, the axially inner wall 18B And while it can prevent that the bead part 4 adheres to the recessed part 18 in the axial direction outer side wall 18C, the bead part 4 adheres in the bottom face 18A, and the inside of the shaping drums 14 and 14 is sealed. As a result, the green case 1 is held by the tire molding apparatus 10 while keeping the inside airtight between the pair of shaping drums 14 without being in close contact with the bead lock 16 excessively.

  Then, after a tread ring (not shown) is disposed on the radially outer side of the green case 1 held by the bead lock 16 so as to surround the green case 1, a fluid supply portion (not shown) The green case 1 is expanded radially outward R1 by moving the pair of shaping drums 14, 14 in the axial direction L2 so as to be close to each other while supplying. That is, the green case 1 is deformed in a toroidal shape in accordance with the tire shape. As a result, the green case 1 can be integrally joined to the tread ring disposed radially outward, and the green tire is formed.

  Then, the bead portion 16 is removed from the recess 18 by moving the bead lock 16 radially inward R2 while holding the outer peripheral surface of the formed green tire by holding means (not shown), and the green tire is held. Deliver to the means. The resulting green tire is vulcanized and molded in a mold to obtain a pneumatic tire.

  According to the present embodiment, since the coatings 22 and 24 made of the material with good releasability are disposed on a part of the portion (contact surface) in contact with the bead portion 4 of the green case 1, the molded green tire When taking out, the bead part 4 can be easily pulled apart from the recessed part 18, and it can take out the green tire shape | molded rapidly, without damaging.

  Further, in the present embodiment, since the good releasability material is not disposed in the remaining part of the contact surface in contact with the bead part 4 of the green case 1, the bead part 4 of the green case 1, the bead lock 16 and The insides of the shaping drums 14 and 14 can be kept in an airtight state by closely adhering to each other.

  Moreover, in the present embodiment, the good releasability material is disposed on axially both side portions of the bead portion 4 (that is, the axially inner side wall 18B and the axially outer side wall 18C) to suppress close contact with the bead portion 4. The bead portion 4 is in close contact with the axial center portion (that is, the bottom surface 18A) of the bead portion 4. The bottom surface 18A of the recess 18 to which the bead portion 4 adheres has a surface perpendicular to the direction (radial direction outward) in which the bead portion 4 is pulled away from the recess 18. 4 can be pulled away from the bottom surface 18A, and can be taken out quickly without damaging the molded green tire.

  In particular, in the manufacture of a pneumatic tire for heavy load or small trucks, a high internal pressure is applied during shaping, and the bead portion 4 easily adheres to the concave portion 18 of the bead lock 16. However, the shaft of the concave portion 18 as in this embodiment The good releasability material is disposed on the direction inner side wall 18B and the axial direction outer wall 18C, and the good releasability material is not provided on the bottom face 18A, thereby maintaining the inside airtight between the shaping drums 14 and 14 The adhesion of the bead portion 4 to the recess 18 can be suppressed, which is advantageous in the manufacture of a heavy duty or small truck pneumatic tire.

Second Embodiment
Next, a second embodiment of the present invention will be described based on FIG. The same parts as those of the first embodiment will not be described, and only different parts will be described.

  In the present embodiment, the method of providing a good releasability material in the recess 18 is different from the first embodiment described above.

  Specifically, as shown in FIG. 4, the bead lock 16 includes a base portion 17 formed of a metal material such as aluminum or stainless steel in a predetermined shape, resin containing portions 26 and 28, and resin members 27 and 29. .

  The resin storage portion 26 is formed of a recess extending along the circumferential direction and provided at a position corresponding to the axial inner wall 18 B of the recess 18, and the resin member 27 is provided therein. The resin member 27 is made of a resin material (good releasability material) that is more excellent in releasability than the metal material that constitutes the base 17. The surface of the resin member 27 constitutes an axial inner wall 18 B of the recess 18 and is smoothly connected to the bottom surface 18 A of the recess 18.

  The resin storage portion 28 is formed of a recess extending along the circumferential direction and provided at a position corresponding to the axial outer wall 18C of the recess 18, and the resin member 29 is provided in the recess. The resin member 29 is made of a resin material that is more excellent in releasability than the metal material that constitutes the base 17. The surface of the resin member 29 constitutes an axial outer wall 18 C of the recess 18 and is smoothly connected to the bottom surface 18 A of the recess 18.

  In addition, it is preferable that the thickness of the resin members 27 and 29 provided in the resin accommodating parts 26 and 28 is 1 mm or more and 3 mm or less.

  In the present embodiment as described above, since the resin members 27 and 29 made of a material with good releasability are provided in the concave resin storage portions 26 and 28 provided in the bead lock 16, the tire molding apparatus 10 can be obtained. Even if molding of a green tire is repeated using it, the resin members 27 and 29 are less likely to wear out.

  The other configurations and operational effects are the same as those of the first embodiment, and the detailed description will be omitted.

(Other embodiments)
In the first and second embodiments described above, the case where the axially inner side wall 18B and the axially outer side wall 18C of the recess 18 are formed of a material that is more excellent in releasability than the bottom surface 18A has been described. An area made of a superior material can be provided in any area of the contact surface in contact with the bead portion 4 in the recess 18.

  While the embodiments of the present invention have been described above, the embodiments are presented as examples and are not intended to limit the scope of the invention. This novel embodiment can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 1 ... green case, 2 ... carcass ply, 3 ... bead member, 3 A ... bead core, 3 B ... bead filler, 4 ... bead part, 5 ... inner liner, 6 ... chafer, 7 ... sidewall rubber, 10 ... tire forming apparatus , 12: shaft, 14: shaping drum, 16: bead lock, 17: base, 18: recess, 18A: bottom surface, 18B: axial inner wall, 18C: axial outer wall, 22: coating, 24: coating, 26 ... Resin storage unit, 27 ... resin member, 28 ... resin storage unit, 29 ... resin member

Claims (5)

In a tire forming apparatus for holding a green case in which a bead portion provided with a bead filler on an outer peripheral side of an annular bead core is rolled in at a width direction end of a cylindrical carcass,
A bead lock for holding the green case in contact with the radially inner side surface of the bead portion;
The said bead lock is a tire molding apparatus with which the 1st area | region which comprises a part of contact surface with the said bead part is formed with the material which was more excellent in the mold release property than the 2nd area | region which comprises the remainder.   The tire molding apparatus according to claim 1, wherein the first region is formed of a resin, and the second region is formed of a metal.   The tire molding apparatus according to claim 1, wherein the first region abuts on an inner side in an axial direction of the bead portion.   The tire molding device according to any one of claims 1 to 3, wherein the second region abuts on the inner side in the tire radial direction of the bead portion.   The bead lock includes a base formed of metal forming the two regions, a resin storage portion provided in the base, and a resin member provided in the resin storage portion to form the first region. The thickness of the said resin member is 1 mm or more and 3 mm or less, The tire forming apparatus of any one of Claims 2-4.

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