JP7029291B2 - Tire molding equipment - Google Patents

Description

The present invention relates to a tire molding apparatus.

As a method of manufacturing a pneumatic tire, there is a method of molding a green tire (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 circumference of the molding drum of the primary molding machine and provided in a cylindrical shape, the annular bead core and the bead filler are extrapolated to both ends of the cylindrical carcass ply in the axial direction. .. Then, after folding the carcass ply so as to wrap the bead core at both ends in the axial direction, the sidewall rubber is laminated to form the green case.

In a secondary molding machine, the obtained green case is held by a bead lock from the radial inside of the bead portion, and the central portion in the axial direction is inflated and shaped like a toroid to form a tread ring made of a belt and tread rubber. Join to form a raw tire. Then, the obtained raw tire is vulcanized and molded in a mold to obtain a pneumatic tire (Patent Documents 1 to 3).

Japanese Unexamined Patent Publication No. 2004-9457 Japanese Unexamined Patent Publication No. 2001-293793 Japanese Unexamined Patent Publication No. 9-12330

In a tire molding machine as a secondary molding machine that performs shaping as described above, the bead portion is excessively adhered to the bead lock during shaping, which makes it difficult to remove the molded raw tire and reduces workability, or at the time of removal. The bead part may be damaged.

The first tire forming apparatus of the present invention is a tire forming 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 around a widthwise end of a cylindrical carcass. A bead lock that abuts on the radial inner surface of the bead portion to hold the green case is provided. It is made of a material that is more releasable than the two regions , and the first region abuts on the inside of the bead portion in the tire axial direction.

The second tire forming apparatus of the present invention is a tire forming 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 around a widthwise end of a cylindrical carcass. A bead lock that abuts on the radial inner surface of the bead portion to hold the green case is provided, and the bead lock has a first region that forms a part of a contact surface with the bead portion, and forms the rest. The second region is formed of a material having better releasability than the two regions, and the second region abuts on the inner side of the bead portion in the tire radial direction.

The third tire forming apparatus of the present invention is a tire forming 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 around a widthwise end of a cylindrical carcass. A bead lock that abuts on the radial inner surface of the bead portion to hold the green case is provided, and the bead lock has a first region that forms a part of a contact surface with the bead portion, and the remaining portion constitutes the bead lock. The first region is formed of a resin, the second region is formed of a metal, and the beadlock is formed of a metal constituting the second region. It is provided with a base portion, a resin storage portion provided in the base portion, and a resin member provided in the resin storage portion to form the first region, and the thickness of the resin member is 1 mm or more and 3 mm or less. ..

According to the present embodiment, it is possible to prevent the bead portion from being excessively adhered to the bead lock during shaping, and the molded raw tire can be quickly taken out from the bead lock without being damaged.

The half sectional view of the tire molding apparatus which concerns on 1st Embodiment. Enlarged view of the main part of FIG. FIG. 1 is an enlarged cross-sectional view of a main part of the tire forming apparatus of FIG. 1 in a state where the bead portion is held. The enlarged sectional view of the tire molding apparatus which concerns on 2nd Embodiment.

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

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

A carcass ply extending straddling between a pair of bead portions is embedded in the tire, and the carcass ply is composed of at least one ply with both ends locked at the bead portion from the tread portion through the sidewall portion. There is. The carcass ply is formed by coating a plurality of carcass cords arranged in parallel with rubber, and both ends of the carcass ply are folded back from the inside to the outside of the bead member and locked at the bead portion. In the bead portion, a chafer is provided around the folded portion of the 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. Inside the carcass ply, an inner liner for maintaining air pressure is provided over the entire inner surface of the tire.

In order to manufacture this tire, first, these members are wound around the outer circumference of a molding drum of a primary molding machine (not shown) in the order of an inner liner, a chafer, and a carcass ply, and provided in a cylindrical shape. An annular bead member is attached to the outer peripheral surface of the tire. Then, after both ends of the carcass ply in the width direction are folded back so as to involve the bead member, the sidewall rubber is arranged at a predetermined position. As a result, as shown in FIG. 1, a green case 1 having bead portions 4 including an annular bead core 3A at both ends of the cylindrical carcass ply 2 is formed. The green case 1 has a structure in which a bead member 3 composed of an annular bead core 3A and a bead filler 3B provided on the outer peripheral side thereof is provided in the bead portion 4, and the bead member 3 is wound at both ends of the carcass ply 2. .. Further, the green case 1 includes an inner liner 5, a chafer 6, and a sidewall rubber 7.

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

Specifically, as shown in FIG. 1, the tire forming apparatus 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. 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 are provided.

The pair of shaping drums 14, 14 are arranged at intervals in the axial direction L, and are rotationally driven around the axis of the shaft 12 by a driving means (not shown), and in the axial direction L so that they can be separated from each other. It is configured to be movable.

The bead lock 16 is a member that abuts on the bead portion 4 from the inside in the radial direction of the tire to hold the green case 1. The beadlock 16 is attached to the outer peripheral surface of the shaping drum 14, is divided into a plurality of segments in the circumferential direction thereof, and is provided so as to be able to expand or contract in the radial direction R. Therefore, the bead lock 16 is provided so as to be movable in the axial direction L and can be expanded / contracted in the radial direction R, so that the bead lock 16 expands / contracts inward in the radial direction of the bead portion 4.

The beadlock 16 includes a base 17 formed by molding a metal material such as aluminum or stainless steel into a predetermined shape. The base 17 has a recess 18 that is opened outward in the radial direction and receives the bead portion 4 from the inside in the radial direction. The concave portion 18 has a concave groove shape extending along the circumferential direction of the radial outer surface facing the bead portion 4, and the concave portion 18 forms a radial inner end portion of the bead portion 4. Receive and hold the green case 1.

As shown in FIGS. 1 and 2, the recess 18 has a bottom surface 18A parallel to the axial direction L to which the radial inner side surface 4A of the bead portion 4 abuts, and the bottom surface 18A radially outward from the axial inner end. It includes an axial inner side wall 18B that rises, and an axial outer wall 18C that rises radially outward from the axial outer end of the bottom surface 18A.

The axial inner side wall 18B of the recess 18 has a curved surface having an arcuate cross section along the shape of the axial inner side surface 4B of the bead portion 4. The axial outer wall 18C of the recess 18 has an inclined surface that inclines toward the axial outer side toward the outer side in the radial direction.

As shown in FIG. 3, when the recess 18 holds the bead portion 4, the axial inner side surface 4B of the bead portion 4 comes into contact with the axial inner side wall 18B of the recess 18, and the radial inner side surface 4A of the bead portion 4 is the recess 18. The axial outer surface 4C of the bead portion 4 (or the edge portion between the radial inner surface 4A and the axial outer surface 4C of the bead portion 4) comes into contact with the axial outer wall 18C of the recess 18. do. That is, the axial inner side wall 18B, the bottom surface 18A, and the axial outer wall 18C of the recess 18 form a contact surface in contact with the bead portion 4.

In the tire forming apparatus 10 having such a configuration, of the axial inner side wall 18B, the bottom surface 18A and the axial outer wall 18C of the recess 18 constituting the contact surface with the bead portion 4, the axial inner side wall 18B and the axial outer side The wall 18C is made of a material having better releasability than the bottom surface 18A (hereinafter, may be referred to as a good releasable material).

In the present embodiment, the bottom surface 18A of the recess 18 is exposed to the metal material constituting the base 17, and the surfaces of the axial inner side wall 18B and the axial outer wall 18C are provided with coatings 22 and 24 made of a good releasable material. It is formed. Specific examples of the good release material include fluororesins such as polytetrafluoroethylene (PTFE), perfluoroalkoxy alkane resin (PFA), fluorinated ethylene / fluorinated propylene copolymer (FEP), and silicone resins. , Nylon resin, silicon resin, polyurethane resin and other resins.

The tire forming 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 toroid shape by the fluid supplied from the fluid supply unit. Has been done.

The tire forming apparatus 10 also includes a holding means (not shown) for holding a cylindrical tread ring (not shown) in which a belt and tread rubber are laminated on the radial outer side of the green case 1.

To form a raw 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 arranged over the outer peripheral portions of the pair of shaping drums 14, 14, the bead lock 16 is radially inside to outside of the bead portion 4. Move to R1 (that is, increase the diameter of the beadlock 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 having better releasability than the bottom surface 18A are provided on the surfaces of the axial inner side wall 18B and the axial outer wall 18C of the recess 18, the axial inner side wall 18B The bead portion 4 can be prevented from coming into close contact with the recess 18 on the outer wall 18C in the axial direction, and the bead portion 4 comes into close contact with the concave portion 18 on the bottom surface 18A to seal the inside of the shaping drums 14 and 14. As a result, the green case 1 is held by the tire forming apparatus 10 while maintaining the inside between the pair of shaping drums 14 and 14 in an airtight state without being excessively adhered to the beadlock 16.

Then, after disposing a tread ring (not shown) so as to surround the green case 1 on the radial outside of the green case 1 held by the beadlock 16, a fluid is supplied into the green case 1 from a fluid supply unit (not shown). The green case 1 is bulged outward in the radial direction by moving the pair of shaping drums 14 and 14 inward L2 in the axial direction so as to be close to each other. That is, the green case 1 is deformed into a toroid shape that matches the tire shape. As a result, the green case 1 can be joined and integrated with the tread ring arranged on the outer side in the radial direction, and the raw tire is formed.

Then, while holding the outer peripheral surface of the molded raw tire by a holding means (not shown), the bead lock 16 is moved inward R2 in the radial direction, so that the bead portion 4 is removed from the recess 18 and the raw tire is held. Hand over to the means. The obtained raw 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 a good releasable material are arranged in a part of the portion (contact surface) in contact with the bead portion 4 of the green case 1, the raw tire is molded. The bead portion 4 can be easily separated from the recess 18 when the tire is taken out, and the molded raw tire can be quickly taken out without being damaged.

Further, in the present embodiment, since the good release material is not disposed in the remaining portion of the contact surface in contact with the bead portion 4 of the green case 1, the bead portion 4 and the bead lock 16 of the green case 1 are arranged in the remaining portion. Can be in close contact with each other to maintain an airtight state between the shaping drums 14 and 14.

Moreover, in the present embodiment, a good releasable material is disposed on both axially side portions (that is, the axial inner side wall 18B and the axial outer wall 18C) of the bead portion 4 to suppress adhesion to 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. Since the bottom surface 18A of the recess 18 to which the bead portion 4 is in close contact has a surface perpendicular to the direction in which the bead portion 4 is separated from the recess 18 (outward in the radial direction), the bead portion is formed even with a relatively small stress. 4 can be separated from the bottom surface 18A, and the molded raw tire can be quickly taken out without being damaged.

In particular, in the manufacture of pneumatic tires for heavy loads or light trucks, a high internal pressure is applied during shaping, and the bead portion 4 easily adheres to the recess 18 of the bead lock 16, but the shaft of the recess 18 is as in the present embodiment. By arranging the good release material on the directional inner side wall 18B and the axial outer wall 18C and not arranging the good release material on the bottom surface 18A, the inside is kept airtight between the shaping drums 14 and 14. It is possible to suppress the adhesion of the bead portion 4 to the recess 18, which is advantageous in the manufacture of pneumatic tires for heavy loads or light trucks.

(Second Embodiment)
Next, the second embodiment of the present invention will be described with reference to FIG. The same parts as those in the first embodiment will be omitted, and different parts will be described.

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

Specifically, as shown in FIG. 4, the beadlock 16 includes a base portion 17 obtained by molding a metal material such as aluminum or stainless steel into a predetermined shape, resin storage portions 26, 28, and resin members 27, 29. ..

The resin storage portion 26 is composed of a recess extending along the circumferential direction provided so as to open at a position corresponding to the axial inner side wall 18B of the recess 18, and the resin member 27 is provided inside the recess. The resin member 27 is made of a resin material (good releasable material) having better releasability than the metal material constituting the base 17. The surface of the resin member 27 constitutes the axial inner side wall 18B of the recess 18, and is smoothly connected to the bottom surface 18A of the recess 18.

The resin storage portion 28 is composed of a recess extending along the circumferential direction provided so as to open at a position corresponding to the axial outer wall 18C of the recess 18, and the resin member 29 is provided inside the recess. The resin member 29 is made of a resin material having better releasability than the metal material constituting the base 17. The surface of the resin member 29 constitutes the axial outer wall 18C of the recess 18, and is smoothly connected to the bottom surface 18A of the recess 18.

The thickness of the resin members 27 and 29 provided in the resin storage portions 26 and 28 is preferably 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 the good releasable material are provided in the concave resin storage portions 26 and 28 provided in the beadlock 16, the tire forming apparatus 10 is provided. Even if the raw tire is repeatedly molded by using the resin members 27 and 29, the resin members 27 and 29 are less likely to be worn.

The other configurations and actions and effects are the same as those in the first embodiment, and detailed description thereof will be omitted.

(Other embodiments)
In the first embodiment and the second embodiment described above, the case where the axial inner side wall 18B and the axial outer wall 18C of the recess 18 are formed of a material having better releasability than the bottom surface 18A has been described. The region formed of the excellent material can be provided in any region of the contact surface in contact with the bead portion 4 in the recess 18.

Although the embodiment of the present invention has been described above, this embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention.

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

Claims (7)

In a tire molding device that holds 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 around the widthwise end of a cylindrical carcass.
A bead lock that abuts on the radial inner surface of the bead portion to hold the green case is provided.
In the beadlock, the first region forming a part of the contact surface with the bead portion is formed of a material having better releasability than the second region forming the rest .
A tire forming apparatus in which the first region abuts on the inside of the bead portion in the tire axial direction. In a tire molding device that holds 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 around the widthwise end of a cylindrical carcass.
A bead lock that abuts on the radial inner surface of the bead portion to hold the green case is provided.
In the beadlock, the first region forming a part of the contact surface with the bead portion is formed of a material having better releasability than the second region forming the rest .
A tire molding device in which the second region abuts on the inner side of the bead portion in the tire radial direction. In a tire molding device that holds 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 around the widthwise end of a cylindrical carcass.
A bead lock that abuts on the radial inner surface of the bead portion to hold the green case is provided.
In the beadlock, the first region forming a part of the contact surface with the bead portion is formed of a material having better releasability than the second region forming the rest .
The first region is made of resin and the second region is made of metal.
The beadlock includes a base portion made of a metal constituting the second region, a resin storage portion provided in the base portion, and a resin member provided in the resin storage portion and forming the first region. , A tire molding device in which the thickness of the resin member is 1 mm or more and 3 mm or less. The tire molding apparatus according to claim 1 or 2 , wherein the first region is made of resin and the second region is made of metal. The tire molding apparatus according to claim 2 or 3 , wherein the first region abuts on the inner side of the bead portion in the tire axial direction. The tire molding apparatus according to claim 1 or 3 , wherein the second region abuts on the inner side of the bead portion in the tire radial direction. The beadlock includes a base portion made of a metal constituting the second region, a resin storage portion provided in the base portion, and a resin member provided in the resin storage portion and forming the first region. The tire molding apparatus according to claim 1 or 2 , wherein the thickness of the resin member is 1 mm or more and 3 mm or less.

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