METHOD FOR MANUFACTURING MOTORCYCLE TIRE

• US 20140338818A1
• Filed: 05/06/2014
• Published: 11/20/2014
• Est. Priority Date: 05/20/2013
• Status: Active Grant

• Current Assignee: Sumitomo Rubber Industries Limited
• Original Assignee: Sumitomo Rubber Industries Limited
• Inventors: OTANI, Masafumi
• Granted Patent: US 9,962,891 B2
• Time in Patent Office: Days
• US Class Current: 156/117
• CPC Class Codes: B29D 2030/2664 the drum comprising at least two portions that are axially separable, e.g. the portions being supported by different shafts, e.g. in order to facilitate the insertion of the beads
• CPC Class Codes: B29D 30/16 Applying the layers; Guiding or stretching the layers during application applying tread bands to carcasses B29D30/58; retreading B29D30/54
• CPC Class Codes: B29D 30/1621 by feeding a continuous band and winding it spirally, i.e. the band is fed without relative movement along the core axis, to form an annular element winding and joining, spirally in general B29C53/562
• CPC Class Codes: B29D 30/1628 by feeding a continuous band and winding it helically, i.e. the band is fed while being advanced along the core axis, to form an annular element winding and joining, helically in general B29C53/58
• CPC Class Codes: B29D 30/242 for manufacturing substantially cylindrical tyre components without cores or beads, e.g. treads or belts
• CPC Class Codes: B29D 30/36 Expansion of tyres in a flat form , i.e. expansion to a toroidal shape independently of their building-up process, e.g. of tyres built by the flat-tyres method or by jointly covering two bead-rings
• CPC Class Codes: B29D 30/70 Annular breakers

Abstract

A method for manufacturing a motorcycle tire comprises: building a raw tire main body, building a breaker, sticking the breaker, and building a band. The building of the breaker comprises: moving two cylindrical support rings to operating positions, swelling the raw tire main body to have its crown portion protruding from the support rings through a gap therebetween, and winding a breaker ply material on the support rings to form a cylindrical breaker ply whose inner surface is adhered to the raw tire main body. The sticking of the breaker comprises: expanding a profiled deck to swell the raw tire main body into a second swollen state, and turning down both edge portions of the breaker while being supported by the profiled deck. The building of the band comprises: spirally winding a tape on the curved breaker ply while being supported by the profiled deck.

Claims

1. A method for manufacturing a motorcycle tire which tire comprises a tread portion, a pair of sidewall portions, a pair of bead portions each with a bead core therein, a carcass extending between the bead portions through the tread portion and the sidewall portions, a breaker disposed radially outside the carcass in the tread portion and composed of two or three plies of cords laid at angles of from 10 to 40 degrees with respect to the tire circumferential direction, and a band disposed radially outside the breaker in the tread portion and composed of at least one ply of at least one cord wound spirally and circumferentially of the tire, comprising

a raw tire main body building process for building a cylindrical raw tire main body comprising a cylindrical carcass formed by winding a strip of carcass ply material into a cylindrical shape, and the bead cores disposed in both end portions of the cylindrical carcass,

a breaker building process for building a cylindrical breaker ply by winding a strip of breaker ply material into a cylindrical shape,

a sticking process for applying both edge portions of the cylindrical breaker ply to the raw tire main body swollen into a toroidal shape by turning down the edge portions,

a band building process for building a band ply on the breaker ply by spirally circumferentially winding a tape for forming the band ply thereon,

wherein

the breaker building process comprises

a support ring closing step in which a pair of support rings each having a cylindrical outer surface are moved from their axially outer standby positions to their axially inner operating positions, wherein the support rings are disposed one on each side of an axial center corresponding to the tire equatorial plane, and supported movably in the axial direction so as to come close to each other or get away from each other,

a first swelling step in which the raw tire main body is swollen into a toroidal shape, while decreasing the distance between the bead cores, so as to become a first swollen state in which a crown portion of the swollen raw tire main body protrudes slightly radially outwardly from the cylindrical outer surfaces of the support rings through a gap therebetween, and

a winding step in which a strip of the breaker ply material is wound on the support rings to extend across the gap, whereby a cylindrical breaker ply whose inner circumferential surface is adhered to the protruding crown portion of the raw tire main body is formed,

the sticking process comprises

a second swelling step in which, after the support rings are moved to the standby positions, a profiled deck is expanded from its contracted state to its expanded state, while decreasing the distance between the bead cores, so that the raw tire main body with the cylindrical breaker ply thereon is swollen to a second swollen state, and the inside thereof is supported by the profiled deck, and

a turn-down step in which, in the state of the raw tire main body supported by the profiled deck, both edge portions of the cylindrical breaker ply are turned down onto the raw tire main body so as to shape the cylindrical breaker ply into a curved breaker ply curved along the outer circumferential surface of the profiled deck, and

the band building process comprises

a tape winding step in which the tape is spirally wound on the outer circumferential surface of the curved breaker ply in the state supported by the profiled deck so that the band ply is formed along the outer circumferential surface of the profiled deck.

2. The method for manufacturing a motorcycle tire according to claim 1, wherein

the stretch of the band ply during vulcanizing the raw tire is in a range of from 0.5% to 5.0%.

3. The method for manufacturing a motorcycle tire according to claim 1, wherein

the amount of protruding of the crown portion of the raw tire main body in the first swelling step from the outer surfaces of the support rings is 5 to 30 mm.

4. The method for manufacturing a motorcycle tire according to claim 1, wherein

in the support ring closing step, the distance between the support rings is set in a range of 50 to 100 mm.

9. The method for manufacturing a motorcycle tire according to claim 2, wherein

the amount of protruding of the crown portion of the raw tire main body in the first swelling step from the outer surfaces of the support rings is 5 to 30 mm.

10. The method for manufacturing a motorcycle tire according to claim 2, wherein

in the support ring closing step, the distance between the support rings is set in a range of 50 to 100 mm.

11. The method for manufacturing a motorcycle tire according to claim 3, wherein

in the support ring closing step, the distance between the support rings is set in a range of 50 to 100 mm.

5. A method for manufacturing a motorcycle tire which tire comprises a tread portion, a pair of sidewall portions, a pair of bead portions each with a bead core therein, a carcass extending between the bead portions through the tread portion and the sidewall portions, a band disposed radially outside the carcass in the tread portion and composed of at least one ply of at least one cord wound spirally and circumferentially of the tire, and a breaker disposed radially outside the band in the tread portion and composed of two or three plies of cords laid at angles of from 10 to 40 degrees with respect to the tire circumferential direction, comprising

a raw tire main body building process for building a cylindrical raw tire main body comprising a cylindrical carcass formed by winding a strip of carcass ply material into a cylindrical shape, and the bead cores disposed in both end portions of the cylindrical carcass,

a band building process for building a band ply by spirally circumferentially winding a tape for forming the band ply on the raw tire main body swollen into a toroidal shape,

a breaker building process for building a cylindrical breaker ply by winding a strip of breaker ply material into a cylindrical shape,

a sticking process for applying both edge portions of the cylindrical breaker ply to the band ply on the swollen raw tire main body by turning down the edge portions,

wherein

the band building process comprises

a second swelling step in which a profiled deck is expanded from its contracted state to its expanded state while decreasing the distance between the bead cores, so that the raw tire main body is swollen into a second swollen state, and the inside thereof is supported by the profiled deck, and

a tape winding step in which, in the state of the raw tire main body supported by the profiled deck, the tape is spirally wound on the outer circumferential surface of the swollen raw tire main body so that the band ply is formed along the outer circumferential surface of the profiled deck,

the breaker building process comprises

a support ring closing step in which a pair of support rings each having a cylindrical outer surface are moved from their axially outer standby positions to their axially inner operating positions so that the crown portion of the band ply slightly protrudes from the cylindrical outer surfaces of the support rings through a gap therebetween, wherein the support rings are disposed one on each side of an axial center corresponding to the tire equatorial plane, and supported movably in the axial direction so as to come close to each other or get away from each other, and

a winding step in which a strip of the breaker ply material is wound on the support rings to extend across the gap, whereby a cylindrical breaker ply whose inner circumferential surface is adhered to the protruding crown portion of the band ply is formed, and

the sticking process comprises

a turn-down step in which, after the support rings are moved to the standby positions, both edge portions of the cylindrical breaker ply are turned down in the state of the raw tire main body supported by the profiled deck so as to shape the cylindrical breaker ply into a curved breaker ply curved along the outer circumferential surface of the profiled deck.

6. The method for manufacturing a motorcycle tire according to claim 5, wherein

the stretch of the band ply during vulcanizing the raw tire is in a range of from 0.5% to 5.0%.

7. The method for manufacturing a motorcycle tire according to claim 5, wherein

in the support ring closing step, the amount of protruding of the crown portion of the band ply from the outer surfaces of the support rings is 5 to 30 mm.

8. The method for manufacturing a motorcycle tire according to claim 5, wherein

in the support ring closing step, the distance between the support rings is set in a range of 50 to 100 mm.

12. The method for manufacturing a motorcycle tire according to claim 6, wherein

in the support ring closing step, the amount of protruding of the crown portion of the band ply from the outer surfaces of the support rings is 5 to 30 mm.

13. The method for manufacturing a motorcycle tire according to claim 6, wherein

in the support ring closing step, the distance between the support rings is set in a range of 50 to 100 mm.

14. The method for manufacturing a motorcycle tire according to claim 7, wherein

in the support ring closing step, the distance between the support rings is set in a range of 50 to 100 mm.