JP2018065323A - Tire manufacturing apparatus and tire manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust a tension of a belt assembly in a tire when manufacturing the tire using the belt assembly formed by a belt and a belt reinforcing layer.SOLUTION: In a tire manufacturing apparatus 1, a belt 3 and a belt reinforcing layer 5 are combined at a periphery 21 of a drum 20. At the periphery 21 of the drum 20, a belt assembly 4 is molded by the belt 3 and the belt reinforcing layer 5 to manufacture a tire. A outer peripheral shape of the drum 20 is set based on a tension of the belt assembly 4 to be applied in the tire.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a tire manufacturing apparatus and a tire manufacturing method for manufacturing a tire by forming a belt assembly using a belt and a belt reinforcing layer.

  At the time of manufacturing a tire, an unvulcanized tire (raw tire) is formed by a plurality of tire constituent members, and the unvulcanized tire is vulcanized to manufacture a tire. The plurality of tire constituent members are generally arranged on the outer peripheral portion of the drum and combined with each other as a part of the unvulcanized tire. Further, in a tire including a belt and a belt reinforcing layer, a belt assembly may be formed from the belt and the belt reinforcing layer, and the tire may be manufactured using the belt assembly. Conventionally, as such a tire manufacturing apparatus, a molding apparatus is known in which a belt layer (belt) and a belt auxiliary layer (belt reinforcing layer) are wound around an outer peripheral portion of a belt drum (drum) in order and combined (see Patent Document 1). ).

  In the conventional molding apparatus described in Patent Document 1, first, the outer periphery of the drum is made flat when viewed in the cross section in the drum width direction, and the belt is wound around the outer periphery of the drum. Next, the outer periphery of the drum is deformed into an arcuate convex shape as seen in the drum width direction cross section, and the belt reinforcing layer is wound around the belt. At that time, the outer peripheral portion of the drum is deformed into the same shape as the finished shape of the belt reinforcing layer in the mold or a shape close to the finished shape. At the outer periphery of the drum after deformation, the belt and the belt reinforcing layer are combined to form a belt assembly.

  Regarding the belt assembly, for example, by increasing the tension of the belt assembly in a predetermined portion of the tire, the diameter growth of the predetermined portion of the tire is suppressed during rotation of the tire. As in this example, the tire characteristics may change corresponding to the tension of the belt assembly in the tire. However, the conventional molding apparatus cannot easily cope with the change in the tension of the belt assembly, and it is difficult to adjust the tension applied to the belt assembly in the tire.

JP-A-1-249429

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to reduce the tension of the belt assembly in the tire when the tire is manufactured using the belt assembly formed by the belt and the belt reinforcing layer. Is to adjust.

The present invention is a tire manufacturing apparatus for manufacturing a tire by forming a belt assembly by combining a belt and a belt reinforcing layer at an outer peripheral portion of a drum. The outer peripheral shape of the drum is set based on the tension of the belt assembly applied in the tire.
Further, the present invention is a tire manufacturing method for manufacturing a tire by forming a belt assembly by combining a belt and a belt reinforcing layer at an outer peripheral portion of a drum. The outer peripheral shape of the drum is set based on the tension of the belt assembly applied in the tire. A belt and a belt reinforcing layer are arranged on the outer periphery of the set-shaped drum, and a belt assembly is formed on the outer periphery of the drum.

  ADVANTAGE OF THE INVENTION According to this invention, when manufacturing a tire using the belt assembly shape | molded by a belt and a belt reinforcement layer, the tension | tensile_strength of the belt assembly in a tire can be adjusted.

It is a front view which shows schematic structure of the tire manufacturing apparatus of this embodiment. It is a figure which shows the example of the outer periphery shape of a 2nd drum.

Hereinafter, an embodiment of a tire manufacturing apparatus and a tire manufacturing method of the present invention will be described with reference to the drawings.
The tire manufacturing apparatus and the tire manufacturing method of this embodiment form an unvulcanized tire with a plurality of tire constituent members to manufacture a tire (product tire). The tire constituent member is a rubber member used for molding an unvulcanized tire, and is formed only by rubber (unvulcanized rubber) or by rubber and another member (cord or the like). The tire manufacturing apparatus and the tire manufacturing method form an unvulcanized tire by combining a plurality of tire constituent members with a drum.

FIG. 1 is a front view showing a schematic configuration of a tire manufacturing apparatus 1 of the present embodiment.
As illustrated, the tire manufacturing apparatus 1 includes two drums 10 and 20 (first drum 10 and second drum 20) and two drum driving devices 30 and 40 (first drum driving) that drive the drums 10 and 20. Device 30, second drum driving device 40), transport device 50, and control device 2. The control device 2 is a control means for controlling the entire tire manufacturing device 1 and controls a tire manufacturing operation (unvulcanized tire molding operation) by the tire manufacturing device 1.

  The drums 10 and 20 are cylindrical forming drums used for forming unvulcanized tires, and rotate around an axis. The directions of the axes of the drums 10 and 20 (drum axis direction) are arranged in the horizontal direction and are located on the same straight line. The outer peripheral portions 11 and 21 of the drums 10 and 20 are molding surfaces (outer peripheral surfaces) for molding the tire constituent members, and are expanded and contracted by an expansion and contraction mechanism provided in the drums 10 and 20. The tire constituent member is disposed on the outer peripheral portions 11 and 21 and is formed into an annular shape by the outer peripheral portions 11 and 21. The shaft portions 12 and 22 of the drums 10 and 20 are attached to the drum driving devices 30 and 40, and the drums 10 and 20 are detachably connected to the drum driving devices 30 and 40.

  The drum driving devices 30 and 40 support the drums 10 and 20 and drive the drums 10 and 20. The drums 10 and 20 are disposed at positions separated from each other in the drum axis direction, and face each other between the drum driving devices 30 and 40. The drum drive devices 30 and 40 are rotation drive devices that rotate the drums 10 and 20, and for example, the drums 10 and 20 are rotated by a motor. Further, the drum driving devices 30 and 40 drive the expansion / contraction mechanism of the drums 10 and 20, and the outer peripheral portions 11 and 21 of the drums 10 and 20 are expanded and contracted. Thereby, the outer diameters of the drums 10 and 20 are changed.

  The first drum 10 is a belt forming drum that forms the belt 3, and is rotatably connected to the first drum driving device 30. The outer peripheral portion 11 of the first drum 10 is parallel to the width direction of the first drum 10 (drum width direction H1), and has a flat shape (flat shape) as viewed in the cross section of the drum width direction H1. The drum width direction H1 is the same direction as the drum axis direction of the first drum 10, and the outer peripheral portion 11 of the first drum 10 extends along the drum width direction H1. The belt-shaped belt 3 is wound around the outer peripheral portion 11 of the first drum 10, and the belt 3 is formed into a cylindrical shape by the outer peripheral portion 11 of the first drum 10. The first drum 10 holds the cylindrical belt 3 on the outer peripheral portion 11.

  The belt 3 is made of one or more belt materials (belt plies), and is supplied to the outer peripheral portion 11 of the first drum 10 by a supply device. The belt member has a plurality of cords (for example, steel cords) arranged in parallel and is formed in a belt shape. When the belt 3 includes a plurality of belt materials, the plurality of belt materials are wound around the outer peripheral portion 11 of the first drum 10 in order and overlapped at the outer peripheral portion 11. Note that a plurality of belt materials may be wound around the outer peripheral portion 11 of the first drum 10 in a state of being overlapped.

  The rigidity of the belt 3 is relatively high among the plurality of tire constituent members. Therefore, it is difficult to greatly deform the belt 3 when the belt 3 is wound. Here, since the outer peripheral portion 11 of the first drum 10 has a flat shape, the belt 3 is easily and accurately wound around the outer peripheral portion 11 of the first drum 10. The occurrence of wrinkles or warpage in the belt 3 is suppressed, and the belt 3 can be neatly wound around the outer peripheral portion 11 of the first drum 10 without reworking after winding. Further, both end portions of the belt 3 are accurately joined.

  The transport apparatus 50 includes a moving unit 52 that moves along the guide rail 51 and a cylindrical holding unit 53 that is installed in the moving unit 52. The guide rail 51 is laid between the drum driving devices 30 and 40 to guide the moving unit 52 to the first drum 10 and the second drum 20. The moving unit 52 includes, for example, a rotating body that is rotated by a motor, and moves along the guide rail 51 by the rotating body. The transport device 50 moves to the first drum 10 and the second drum 20 by the moving unit 52. When the transport device 50 moves to the first drum 10, the first drum 10 and the belt 3 are disposed inside the holding unit 53.

  The holding part 53 has a plurality of movable members 54 surrounding the first drum 10, and a position at which the plurality of movable members 54 are brought into contact with the outer peripheral surface of the belt 3 (holding position) and an outer peripheral surface of the belt 3 by a driving mechanism. Move to a position where it leaves (release position). The holding unit 53 moves the plurality of movable members 54 to the holding position, and holds the cylindrical belt 3 by the plurality of movable members 54. In addition, the holding unit 53 moves the plurality of movable members 54 to the release position, releases the holding of the belt 3 by the plurality of movable members 54, and releases the belt 3. The conveyance device 50 holds the belt 3 disposed on the outer peripheral portion 11 of the first drum 10 by the holding portion 53. In this state, the outer peripheral portion 11 of the first drum 10 is reduced, and the belt 3 is transferred from the first drum 10 to the conveying device 50.

  The conveying device 50 moves toward the second drum 20 and conveys the belt 3 from the first drum 10 to the second drum 20. When the transport device 50 moves to the second drum 20, the second drum 20 is disposed inside the holding unit 53 and the belt 3. In this state, the outer peripheral portion 21 of the second drum 20 is enlarged and pressed against the inner peripheral surface of the belt 3. The conveyance device 50 releases the belt 3 from the holding unit 53 and delivers the belt 3 to the second drum 20. Thereafter, the transport device 50 moves toward the first drum 10 and leaves the second drum 20. As the outer peripheral portion 21 of the second drum 20 is enlarged, the belt 3 is deformed by the outer peripheral portion 21 of the second drum 20 and formed into a shape corresponding to the shape (outer peripheral shape) of the outer peripheral portion 21.

  The second drum 20 is an assembly drum for assembling the belt assembly 4 and is rotatably connected to the second drum driving device 40. The width direction (drum width direction H2) of the second drum 20 is the same direction as the drum axis direction of the second drum 20, and is orthogonal to the radial direction (drum radial direction) of the second drum 20. The outer peripheral portion 21 of the second drum 20 has a convex shape that bulges outward in the drum radial direction at the center of the second drum 20 in the drum width direction H2, and extends in a curved manner along the drum width direction H2. Further, the outer peripheral portion 21 of the second drum 20 has an arcuate convex shape as viewed in the cross section in the drum width direction H2, and is curved in an arc shape. For example, the outer peripheral portion 21 of the second drum 20 is formed with a predetermined radius of curvature as viewed in the cross section in the drum width direction H2.

  The belt assembly 4 is a cylindrical belt member including a cylindrical belt 3 and an annular belt reinforcing layer 5 and is disposed between the carcass and the tread rubber in the tire. The belt reinforcing layer 5 is wound around the belt 3, and the belt 3 and the belt reinforcing layer 5 are combined at the outer peripheral portion 21 of the second drum 20. As a result, one or more belt reinforcing layers 5 are superposed on the belt 3, and the belt assembly 4 is formed by the belt 3 and the belt reinforcing layer 5. The belt assembly 4 is formed into a cylindrical shape by the outer peripheral portion 21 of the second drum 20. The second drum 20 holds the cylindrical belt assembly 4 on the outer peripheral portion 21. The belt assembly 4 is removed from the second drum 20 by reducing the outer peripheral portion 21 of the second drum 20.

  The belt reinforcing layer 5 is supplied to the outer peripheral portion 21 of the second drum 20 by a supply device, and is disposed at a predetermined position of the belt 3. The belt reinforcing layer 5 has a plurality of cords (for example, organic fiber cords) arranged in parallel, and reinforces the belt 3. The belt reinforcing layer 5 is made of, for example, a strip-shaped rubber (rubber strip) including one or more cords or a strip-shaped rubber (rubber strip) including a plurality of coats arranged in parallel. A rubber strip is spirally wound around the belt 3 to form the belt reinforcing layer 5. Alternatively, the belt reinforcing layer 5 is formed by winding a rubber band around the belt 3. In this way, the belt reinforcing layer 5 is formed on the belt 3 by being disposed on a part or all of the belt 3. Here, the belt reinforcing layer 5 is disposed at two locations on both edge sides of the belt 3.

  The belt reinforcing layer 5 is more flexible than the belt 3 and easily deforms compared to the belt 3. Therefore, the belt reinforcing layer 5 is easily arranged in accordance with the shape of the belt 3 on the convex outer peripheral portion 21 of the second drum 20. In addition, the occurrence of wrinkles or warpage in the belt reinforcing layer 5 is suppressed, and the belt reinforcing layer 5 is neatly arranged on the belt 3 without reworking after the arrangement.

  The belt assembly 4 is formed into a shape corresponding to the outer peripheral shape of the second drum 20. Here, the belt assembly 4 is formed in a convex shape corresponding to the outer peripheral shape of the second drum 20 and bulging outward in the drum radial direction at the center in the drum width direction H2. Further, the belt assembly 4 is formed into an arcuate convex shape as viewed in the cross section in the drum width direction H2, and is curved in an arc shape.

  Depending on the type of characteristics of the tire (product tire), the tension of the belt assembly 4 in the tire affects the characteristics of the tire, and the characteristics of the tire change corresponding to the tension of the belt assembly 4. For example, by increasing the tension of the belt assembly 4 at a predetermined portion of the tire for which it is desired to suppress the diameter growth, the diameter growth of the predetermined portion of the tire is suppressed when the tire rotates. Therefore, by adjusting the tension of the belt assembly 4, the growth of the tire diameter is controlled, and the performance of the tire during running is improved.

  The tension to be applied to the belt assembly 4 in the tire is set by experiment or calculation. For example, the tension of each part in the tire width direction of the tire is measured, and the tension to be applied to the belt assembly 4 is determined based on the measurement result of the tension. Alternatively, the tension to be applied to the belt assembly 4 by computer calculation (numerical analysis, simulation, etc.) based on the tire running conditions (shape, dimensions, internal structure, deformation behavior, rotation conditions, vehicle conditions, etc.) Determine.

  The tension to be applied to the belt assembly 4 is determined by experiment or calculation, and the tension at each position in the drum width direction H2 of the belt assembly 4 to be applied in the tire is set. The tire width direction corresponds to the drum width direction H2 of the second drum 20, and the tension at each position in the drum width direction H2 of the belt assembly 4 corresponds to the tension at each position in the tire width direction of the belt assembly 4. Correspond. Further, the tension of the belt assembly 4 in the tire changes in accordance with the shape (molded shape) of the belt assembly 4 formed by the outer peripheral portion 21 of the second drum 20.

  As the unvulcanized tire is molded and vulcanized, the belt assembly 4 is deformed from the molded shape, and a tension corresponding to the deformation amount is applied to the belt assembly 4. The tension is increased in the enlarged portion of the belt assembly 4, and the tension of the belt assembly 4 increases corresponding to the amount of expansion. Further, in a portion where the change in shape is relatively small in the belt assembly 4, the tension of the belt assembly 4 is smaller than in other portions. Accordingly, the tension of the belt assembly 4 varies depending on the outer peripheral shape of the second drum 20. The tension of the belt assembly 4 changes corresponding to the difference between the outer peripheral shape of the second drum 20 (the shape of the belt assembly 4) and the shape of the belt assembly 4 in the tire (product shape).

  The outer peripheral shape of the second drum 20 is set based on the tension of the belt assembly 4 applied in the tire. Based on the tension of the belt assembly 4, the difference (shape difference) between the product shape of the belt assembly 4 and the outer peripheral shape of the second drum 20 is determined, and the outer peripheral shape of the second drum 20 is set. As the tension of the belt assembly 4 increases, the shape difference increases and the outer peripheral portion 21 of the second drum 20 decreases in the drum radial direction with respect to the product shape of the belt assembly 4. Further, as the tension of the belt assembly 4 increases, the outer diameter of the second drum 20 becomes smaller than the diameter of the belt assembly 4 in the tire. Based on the tension at each position in the drum width direction H2 of the belt assembly 4, the outer diameter of each position in the drum width direction H2 of the second drum 20 is set to set the outer peripheral shape of the second drum 20.

  Based on the change in the tension of the belt assembly 4 in the drum width direction H2, the outer diameter of the second drum 20 is changed in the drum width direction H2. Thereby, the outer peripheral part 21 of the 2nd drum 20 is formed in the shape corresponding to the outer diameter of each position of the drum width direction H2. Further, the outer peripheral shape of the second drum 20 changes corresponding to the change in the outer diameter of the second drum 20 in the drum width direction H2. The outer diameter of the second drum 20 is set so that the outer diameter of the second drum 20 decreases as the tension increases, for example, corresponding to the tension at each position in the drum width direction H2 of the belt assembly 4.

  Here, the outer diameter of the second drum 20 is made smaller than the outer diameter of the other position at a position where it is desired to suppress the tire diameter growth, and the tension of the belt assembly 4 is made larger than the tension of the other position. Specifically, the position where it is desired to suppress the tire diameter growth is the position on the shoulder portion side of the tread portion of the tire. Therefore, the outer diameter of the second drum 20 is gradually decreased from the central portion in the drum width direction H2 toward both outer sides, and the outer peripheral shape of the second drum 20 is gradually decreased in the drum radial direction. Accordingly, the tension of the belt assembly 4 in the tire is increased at the position on the shoulder portion side, and the tension on the shoulder portion side is made larger than the tension on the central portion side. As a result, in the tread portion of the tire, the diameter growth amount on the shoulder portion side is smaller than the diameter growth amount on the central portion side, and the tire diameter growth is suppressed on the shoulder portion side.

  Next, a tire manufacturing procedure by the tire manufacturing apparatus 1 will be described. First, the belt 3 is disposed on the outer peripheral portion 11 of the first drum 10 to form the cylindrical belt 3. Subsequently, the belt 3 is conveyed from the first drum 10 to the second drum 20 by the conveying device 50, and the belt 3 is disposed on the outer peripheral portion 21 of the second drum 20. After separating the conveying device 50 from the second drum 20, the two belt reinforcing layers 5 are arranged on the outer peripheral portion 21 of the second drum 20 to form the annular belt reinforcing layer 5. The belt 3 and the belt reinforcing layer 5 are sequentially arranged on the outer peripheral portion 21 of the second drum 20 having a set shape (outer peripheral shape), and the belt 3 and the belt reinforcing layer 5 are combined.

  A cylindrical belt assembly 4 is formed by the belt 3 and the belt reinforcing layer 5 on the outer peripheral portion 21 of the second drum 20. Subsequently, the tread rubber is supplied to the outer peripheral portion 21 of the second drum 20 by the supply device, and is arranged on the outer peripheral portion 21 of the second drum 20. A cylindrical tread rubber is formed on the outer peripheral portion 21 of the second drum 20, and the tread rubber is superposed on the belt assembly 4. A belt-tread assembly is formed by the belt assembly 4 and the tread rubber. Thereafter, the belt tread assembly is removed from the second drum 20 and combined with the carcass band. Thereby, the unvulcanized tire including the belt assembly 4 is formed. Moreover, an unvulcanized tire is vulcanized to produce a tire.

  As described above, according to the tire manufacturing apparatus 1 and the tire manufacturing method of the present embodiment, the tension of the belt assembly 4 in the tire can be adjusted according to the tension to be applied. Further, since the outer diameter of the second drum 20 is set based on the tension at each position in the drum width direction H2 of the belt assembly 4, the tension of the belt assembly 4 can be accurately adjusted. By setting the tension of the belt assembly 4 based on the tire diameter growth, the tire diameter growth can be adjusted. Thereby, the diameter growth of a tire can be suppressed.

FIG. 2 is a diagram showing an example of the outer peripheral shape of the second drum 20, and shows the outer peripheral shape of the plurality of second drums 20. FIG. 2 shows a contour shape of the outer peripheral portion 21 of the second drum 20 in the cross section of the second drum 20 including the drum axial direction (cross section in the drum width direction H2).
As illustrated, the outer peripheral portion 21 of the second drum 20 is set in various shapes based on the tension of the belt assembly 4 to be applied in the tire. For example, the outer peripheral shape of the second drum 20 is formed in an arcuate convex shape (see FIGS. 2A and 2B).

  In the tire, when the tension of the belt assembly 4 on the center side is larger than the tension of the belt assembly 4 on the shoulder side (see FIGS. 2C and 2D), the outer peripheral portion 21 of the second drum 20 is The two drums 20 are formed in a concave shape that is recessed inward in the drum radial direction at the center in the drum width direction H2. In this case, the outer peripheral portion 21 of the second drum 20 is formed in an arcuate concave shape as viewed in the cross section in the drum width direction H2, and is curved in an arc shape. As a result, the tension of the belt assembly 4 in the tire increases at the position on the center portion side, and the tension on the center portion side becomes larger than the tension on the shoulder portion side. As a result, for example, in the tread portion of the tire, the radial growth amount on the central portion side is smaller than the radial growth amount on the shoulder portion side, and the radial growth of the tire is suppressed on the central portion side.

  Depending on the shape or tension of the belt assembly 4 in the tire (see FIGS. 2E and 2F), the outer peripheral portion 21 of the second drum 20 is formed in a flat shape in the same manner as the outer peripheral portion 11 of the first drum 10. In this manner, the outer diameter of each position in the drum width direction H2 of the second drum 20 is changed, and the tension at each position in the drum width direction H2 of the belt assembly 4 is changed. Further, the outer diameter of the second drum 20 is changed to change the tension of the belt assembly 4 applied in the tire. As the outer diameter of the second drum 20 increases (see FIGS. 2A, 2C, and 2E), the tension of the belt assembly 4 decreases, and as the outer diameter of the second drum 20 decreases (FIGS. 2B, 2D, and FIG. 2). 2F), the tension of the belt assembly 4 increases. As described above, the tension of the belt assembly 4 and the tension of each position of the belt assembly 4 in the drum width direction H2 are adjusted.

  In addition, when changing the outer periphery shape of the 2nd drum 20, the 2nd drum 20 is removed from the 2nd drum drive device 40, and the 2nd drum 20 connected with the 2nd drum drive device 40 is replaced | exchanged. On the other hand, the outer diameter of the second drum 20 may be changed or the outer peripheral shape of the second drum 20 may be changed by an expansion / contraction mechanism in the second drum 20. Alternatively, the outer diameter of the second drum 20 may be continuously curved to smoothly curve the outer peripheral portion 21 of the second drum 20. The outer diameter of the second drum 20 may be changed discontinuously to form the outer peripheral portion 21 of the second drum 20 in a step shape (a shape having a plurality of steps).

  When forming the belt assembly 4, the belt reinforcing layer 5 may be disposed on the outer peripheral surface of the belt 3, and the belt reinforcing layer 5 may be disposed on the inner peripheral surface of the belt 3. Tire constituent members other than the belt 3 and the belt reinforcing layer 5 may be disposed on the outer peripheral portion 21 of the second drum 20. In this case, other tire constituent members (for example, tread rubber and carcass) are combined with the belt assembly 4. When manufacturing a tire using one, or three or more drums, the belt assembly 4 may be formed on the outer periphery of the drum. The outer peripheral shape of various drums that form the belt assembly 4 is set in the same manner as the outer peripheral shape of the second drum 20.

  DESCRIPTION OF SYMBOLS 1 ... Tire manufacturing apparatus, 2 ... Control apparatus, 3 ... Belt, 4 ... Belt assembly, 5 ... Belt reinforcement layer, 10 ... 1st drum, 11 ... Outer periphery , 12 ... shaft part, 20 ... second drum, 21 ... outer peripheral part, 22 ... shaft part, 30 ... first drum driving device, 40 ... second drum driving device , 50 ... conveying device, 51 ... guide rail, 52 ... moving part, 53 ... holding part, 54 ... movable member.

Claims (6)

A tire manufacturing apparatus for manufacturing a tire by forming a belt assembly by combining a belt and a belt reinforcing layer at an outer periphery of a drum,
A tire manufacturing apparatus for setting an outer peripheral shape of a drum based on a tension of a belt assembly applied in a tire. In the tire manufacturing apparatus according to claim 1,
A tire manufacturing apparatus that sets an outer peripheral shape of a drum by setting an outer diameter of each position of the drum in the drum width direction based on a tension at each position in the drum width direction of the belt assembly. In the tire manufacturing apparatus according to claim 1 or 2,
A tire manufacturing apparatus that changes the tension of the belt assembly by changing the outer diameter of the drum. A tire manufacturing method for manufacturing a tire by forming a belt assembly by combining a belt and a belt reinforcing layer at an outer periphery of a drum,
Based on the tension of the belt assembly applied in the tire, the outer peripheral shape of the drum is set,
A tire manufacturing method in which a belt and a belt reinforcing layer are arranged on an outer peripheral portion of a drum having a set shape, and a belt assembly is formed on the outer peripheral portion of the drum. In the tire manufacturing method according to claim 4,
A tire manufacturing method for setting an outer peripheral shape of a drum by setting an outer diameter of each position in the drum width direction of the drum based on a tension at each position in the drum width direction of the belt assembly. In the tire manufacturing method according to claim 4 or 5,
A tire manufacturing method in which the tension of the belt assembly is changed by changing the outer diameter of the drum.

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