Pneumatic tire manufacturing method and pneumatic tire

1. A pneumatic tire manufacturing method, in making a green tire having two-side fasteners in its tire inner surface in its tire circumferential direction, each two-side fastener including an engagement element group on both sides, the method comprising the steps of:

covering the engagement element groups on first sides of the two-side fasteners with a protective rubber layer made of an uncured rubber;

making a cylindrical first formed body on a making drum, with the two-side fasteners covered with the protective rubber layer being intermittently attached to an inner circumferential surface of the first formed body in a circumferential direction thereof with the engagement element groups on second sides of the two-side fasteners being interposed in between;

bonding the first formed body to an inner circumference of an annular second formed body by compression through expanding the first formed body into a toroidal shape, and thereby making the green tire; and

curing the green tire inside a mold of a curing machine while pressing the green tire from its inside by a bladder.

2. The pneumatic tire manufacturing method according to claim 1 , wherein the first formed body making step comprises:

attaching the two-side fasteners onto one side of the protective rubber layer shaped like a belt at predetermined intervals in a longitudinal direction of the protective rubber layer in a way that the engagement element groups on the first sides of the two-side fasteners are buried in the protective rubber layer;

winding the protective rubber layer having the two-side fasteners around the making drum into a cylindrical shape with the two-side fasteners being located outward;

winding an inner liner layer around the cylindrical protective rubber layer having the two-side fasteners into a cylindrical shape in a way that the engagement element groups on the second sides of the two side fasteners are buried in the inner liner layer; and

adhering the other tire components constituting the first formed body onto the inner liner layer.

3. The pneumatic tire manufacturing method according to claim 1 , wherein the first formed body making steps comprises:

attaching the two-side fasteners onto one side of the protective rubber layer shaped like a belt at predetermined intervals in a longitudinal direction of the protective rubber layer in a way that the engagement element groups on the first sides of the two-side fasteners are buried in the protective rubber layer;

laying the protective rubber layer having the two-side fasteners on an inner liner layer in a way that the engagement element groups on the second sides of the two-side fasteners are buried in the inner liner layer;

winding a laminated body obtained by laying the protective rubber layer having the two-side fasteners on the inner liner layer around the making drum into a cylindrical shape with the protective rubber layer being located closer to the making drum; and

adhering the other tire components constituting the first formed body onto the laminated body.

4. The pneumatic tire manufacturing method according to claim 1 , wherein the first formed body making step comprises:

attaching a belt-shaped two-side fastener onto one side of a belt-shaped protective rubber layer in a longitudinal direction of the protective rubber layer in a way that the engagement element groups on a first side of the two-side fastener are buried in the protective rubber layer, the engagement element groups being arranged on both sides of the two-side fastener at predetermined intervals in a longitudinal direction thereof;

cutting the two-side fastener of the protective rubber layer having the two-side fastener at a location between each neighboring two of the engagement element groups;

winding the protective rubber layer having the two-side fastener thus cut around the making drum into a cylindrical shape with the two-side fastener being located outward;

winding an inner liner layer around the cylindrical protective rubber layer having the two-side fastener into a cylinder shape in a way that the engagement element groups on a second side of the two-side fastener are buried in the inner liner layer; and

adhering the other tire components constituting the first formed body onto the inner liner layer.

5. The pneumatic tire manufacturing method according to claim 1 , wherein the first formed body making step comprises:

attaching a belt-shaped two-side fastener onto one side of a belt-shaped protective rubber layer in a longitudinal direction of the protective rubber layer in a way that the engagement element groups on a first side of the two-side fastener are buried in the protective rubber layer, the engagement element groups being arranged on both sides of the two-side fastener at predetermined intervals in a longitudinal direction thereof;

cutting the two-side fastener of the protective rubber layer having the two-side fastener at a location between each neighboring two of the engagement element groups;

laying the protective rubber layer having the two-side fastener thus cut on an inner liner layer in a way that the engagement element groups on a second side of the two-side fastener are buried in the inner liner layer;

winding a laminated body obtained by laying the protective rubber layer having the two-side fastener thus cut on the inner liner layer around the making drum into a cylindrical shape with the protective rubber layer being located closer to the making drum; and

adhering the other tire components constituting the first formed body onto the laminated body.

6. The pneumatic tire manufacturing method according to claim 1 , wherein the first formed body making step comprises:

attaching a belt-shaped two-side fastener onto one side of a belt-shaped protective rubber layer in a longitudinal direction of the protective rubber layer in a way that the engagement element groups on a first side of the two-side fastener are buried in the protective rubber layer, the engagement element groups being arranged on both sides of the two-side fastener at predetermined intervals in a longitudinal direction of the two-side fastener, and the two-side fastener being provided with a cut line between each neighboring two of the engagement element groups;

winding the protective rubber layer having the two-side fastener around the making drum into a cylindrical shape with the two-side fastener being located outward;

winding an inner liner layer around the cylindrical protective rubber layer having the two-side fastener into a cylindrical shape in a way that the engagement element groups on a second side of the two-side fastener are buried in the inner liner layer; and

adhering the other tire components constituting the first formed body onto the inner liner layer.

7. The pneumatic tire manufacturing method according to claim 1 , wherein the first formed body making step comprises:

attaching a belt-shaped two-side fastener onto one side of a belt-shaped protective rubber layer in a longitudinal direction of the protective rubber layer in a way that the engagement element groups on a first side of the two-side fastener are buried in the protective rubber layer, the engagement element groups being arranged on both sides of the two-side fastener at predetermined intervals in a longitudinal direction of the two-side fastener, and the two-side fastener being provided with a cut line between each neighboring two of the engagement element groups;

laying the protective rubber layer having the two-side fastener on an inner liner layer in a way that the engagement element groups on a second side of the two-side fastener are buried in the inner liner layer;

winding a laminated body obtained by laying the protective rubber layer having the two-side fastener on the inner liner layer around the making drum into a cylindrical shape with the protective rubber layer being located closer to the making drum; and

adhering the other tire components constituting the first formed body onto the laminated body.

8. The pneumatic tire manufacturing method according to claim 1 , wherein the first formed body making step comprises:

covering the engagement element groups on a first side of a belt-shaped two-side fastener with the protective rubber layer made of the uncured rubber, the engagement element groups being arranged on both sides of the two-side fastener at predetermined intervals in a longitudinal direction of the two-side fastener;

laying the belt-shaped two-side fastener covered with the protective rubber layer on an inner liner layer in a way that the engagement element groups on a second side of the two-side fastener are buried in the inner liner layer with a part of the two-side fastener being folded between each neighboring two of the engagement element groups;

winding a laminated body obtained by laying the two-side fastener covered with the protective rubber layer on the inner liner layer around the making drum into a cylindrical shape with the two-side fastener being located closer to the making drum; and

adhering the other tire components constituting the first formed body onto the laminated body.

9. The pneumatic tire manufacturing method according to any one of claims 1 to 8 , wherein the protective rubber layer made of the uncured rubber is cured before the green tire is cured.

10. The pneumatic tire manufacturing method according to claim 1 , wherein the first formed body making step comprises:

attaching a belt-shaped two-side fastener onto one side of a belt-shaped protective rubber layer in a longitudinal direction of the protective rubber layer in a way that the engagement element groups on a first side of the two-side fastener are buried in the protective rubber layer, the engagement element groups being provided onto both sides of the two-side fastener;

curing the protective rubber layer having the two-side fastener while forming the protective rubber layer into a meandering shape in a thickness direction thereof;

attaching the thus-cured and formed protective rubber layer having the two-side fastener to an inner liner layer in a way that the engagement element groups on a second side of the two-side fastener are intermittently buried in the inner liner layer;

winding a complex around the making drum into a cylindrical shape with the protective rubber layer being located closer to the making drum, the complex obtained by attaching the protective rubber layer having the two-side fastener thus formed to the inner liner layer; and

adhering the other tire components constituting the first formed body onto the complex.

11. The pneumatic tire manufacturing method according to claim 1 , wherein the first formed body making step comprises:

attaching a belt-shaped two-side fastener onto one side of a belt-shaped protective rubber layer in a longitudinal direction of the protective rubber layer in a way that the engagement element groups on a first side of the two-side fastener are buried in the protective rubber layer, the engagement element groups being provided on both sides of the two-side fastener;

curing the protective rubber layer having the two-side fastener while forming the protective rubber layer into a meandering shape in a thickness direction thereof;

winding the thus-cured and formed protective rubber layer having the two-side fastener around the making drum into a cylindrical shape with the protective rubber layer being located closer to the making drum while keeping the protective rubber layer having the two-side fastener formed into the meandering shape;

winding an inner liner layer around the thus-formed cylindrical protective rubber layer having the two-side fastener into a cylindrical shape in a way that the engagement element groups on a second side of the two-side fastener are intermittently buried in the inner liner layer; and

adhering the other tire components constituting the first formed body onto the inner liner layer.

12. The pneumatic tire manufacturing method according to claim 1 , wherein the first formed body making step comprises:

attaching the two-side fasteners respectively onto first sides of a plurality of protective rubber layers in a way that the engagement element groups on a first side of each two-side fastener are buried in a corresponding one of the protective rubber layers, the engagement element groups being provided on both sides of each two-side fastener;

curing the protective rubber layers having the two-side fasteners while forming the protective rubber layers into a meandering shape in thickness directions thereof;

attaching the thus-cured and formed protective rubber layers having the two-side fasteners to an inner liner layer at predetermined intervals in a longitudinal direction of the inner liner layer in a way that the engagement element groups on a second side of each two-side fastener are intermittently buried in the inner liner layer;

winding a complex around the making drum into a cylindrical shape with the protective rubber layers being located closer to the making drum, the complex being obtained by attaching the thus-formed protective rubber layers having the two-side fasteners to the inner liner layer; and

adhering the other tire components constituting the first formed body onto the complex.

13. The pneumatic tire manufacturing method according to any one of claims 1 to 8 and 10 to 12 , wherein a modulus measured when the rubber of the protective rubber layer or the protective rubber layers is stretched by 100% is 0.2 MPa to 3 MPa.

14. The pneumatic tire manufacturing method according to any one of claims 1 to 8 and 10 to 12 , wherein the protective rubber layer or the protective rubber layers are removed after the green tire is cured.