JP3091578B2 - Tire manufacturing method, tire forming apparatus used therefor, and tire manufactured by the manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of a tire for producing a tire capable of accurately and conveniently folding both ends of a carcass sheet around a bead core, thereby increasing the uniformity of the tire and improving the production efficiency. Method, and for it
Tire manufacturing equipment, and a manufacturing method thereof.
About tires .

[0002]

2. Description of the Related Art In a tire having a radial structure, a carcass is shaped into a donut shape, and a belt or the like is attached to the tire due to the cord arrangement angle. Therefore, conventionally, a radial tire employs a first former for winding a carcass sheet i to form a cylindrical carcass and a second former for shaping the cylindrical carcass into a donut shape to form a green tire. The conventional two-stage molding method is adopted.

[0003] As a first former, for example, FIG.
As shown in FIG. 16, a flat drum provided with a minimum step g enough to accommodate the bead core b, and as shown in FIG. 16b, the outer diameter d of the sticking surface was set to be as large as the drawing operation to the bead portion allowed. High crown drums are generally known.

[0004] However, when a tire using a multilayer body in which a large number of carcass sheets are laminated integrally, such as a heavy load tire, is molded using a high crown drum, a molding method using a flat drum,
Since the shape of the bead portion before vulcanization is significantly different from the bead shape of the finished tire after vulcanization, it includes factors that have residual strain in the bead portion and deteriorate durability.

[0005] In particular, in the case of a radial tire for an aircraft, etc., the carcass sheet i (inner carcass) is generally used.
An outer carcass sheet i1 (outer carcass) is provided on the outside of the tire, and the bead portion shape is fixed in a molded state during vulcanization, so that the finished tire has a large residual strain in the bead portion. Become.

[0006] This is because, in the case of the structure of only the inner carcass without the outer carcass, the ply wound around the bead core is displaced in the vulcanization process to some extent to eliminate the distortion, while the ply wound up around the bead core eliminates the distortion. Because it does not have it.

[0007] Therefore, a high crown drum is used in order to preliminarily mold a bead shape as close as possible to a finished tire. However, in this case, when turning both ends of the multilayer body, a large force F directed outward in the axial direction acts on the bead core b as shown in FIG.
Occurs. This misalignment causes non-uniform cord tension in the finished tire, such as changing the peripheral length of the carcass cord, and further impairs dimensional accuracy and shape accuracy, such as changing the folded length of the carcass left and right, and greatly reduces uniformity. .

That is, the larger the difference in the peripheral length between the inner carcass cord and the outer carcass cord in the molding process and the difference in the peripheral length of each cord determined by the finished product shape, the lower the bead durability of the tire. It turned out that was invited. That is, when considering the radius line K1 raised at the outer end of the drum outer peripheral surface and the radius line K2 pulled down from the center of the bead core b, the length La of the inner carcass between the radius lines K1 and K2, The larger the difference Lb-La from the length Lb of the carcass, the more unevenly the load distribution on the inner carcass increases, impairing the bead durability, and the positional deviation r of the bead core b reduces the difference Lb-La. Could be determined to increase.

Therefore, the present invention is based on the fact that the carcass sheet is folded back while fixing the bead core, thereby improving the uniformity of the tire and improving the bead durability, and contributing to the single-stage molding of the tire, thereby improving the production efficiency. Tire manufacturing method for measurable tires
And a tire manufactured by the manufacturing method thereof .

[0010]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
The invention according to claim 1 of the present application is directed to a car for forming a carcass.
The dregs sheet is provided with a cylindrical outer peripheral surface that can be expanded in diameter.
A step wound around the outer peripheral surface of a drum assembly having a ram
Floor and radially outside of the rolled carcass sheet
The position of the car
Arrange the bead core that forms the protrusion on the waste sheet.
And the both sides of the drum assembly can be moved in the direction of the central axis.
Are arranged on the same central axis and can be moved in the central axis direction.
The bead is expanded by the expanded receiving portion of the
Supporting the core, and both the drum of the drum assembly
A projection that is provided on the side and protrudes outward in the central axis direction;
The ram expands and the bead support moves inward in the center axis direction.
Move the bead core more than the protruding edge
Carrier between the receiving part and the inner side in the center axis direction
Clamping the bead core through the sheet.
It is a manufacturing method of a tire.

The invention according to claim 1 further comprises the bead support.
Of the carcass sheet arranged on each outer side in the central axis direction of the means.
A step of folding the folding means said protruding portion, before
The bead following the reduction operation in the center axis direction of the drum
With the movement of the supporting means, it protrudes by the folding means.
Shaping the carcass sheet with the folded part
And

The invention according to claim 4 of the present application is a carcass component.
A cylindrical carcass sheet wound around the outer peripheral surface
Drum assembly having expandable drum and drum
On both sides of the assembly are arranged on the same central axis and said wound
Outside of the carcass sheet in the radial direction and the center axis than both ends
In the direction of the carcass sheet
With a receiving part that receives the bead core that forms
A bead supporting means movable in monitor central axis direction, the receiving
The carcass sheet disposed on each outer side in the direction of the central axis of the
Folding means for folding the protruding portion of
On both sides of the drum of the drum assembly,
Side and the drum expands in diameter and bead
In the support state in which the support means moves, pierce the bead core.
By positioning it inward in the center axis direction from the protruding edge,
Bead core between the recording unit and the carcass sheet
A projection that can be pinched is formed so as to be connected to the outer peripheral surface.
This is a tire building apparatus.

Further, according to the method for manufacturing a tire according to the present invention,
It is a tire that is produced.

[0014]

In the tire forming apparatus , protrusions are provided on both sides of the expandable drum, and bead support means for receiving a bead core can be moved in the center axis direction of the drum. Therefore, the bead cores can be mounted on both ends of the carcass sheet wound in a straight cylindrical shape on the drum in the reduced diameter state and on the outside in the radial direction. Since the bead core is supported by the receiving portion via the carcass sheet, the carcass sheet is squeezed at the bead portion without disturbing the code arrangement by sliding inward in the center axis direction in synchronization with the expansion of the drum. Can be performed accurately and automatically. Also, after such narrowing, by slightly reducing the diameter of the drum, the bead core can be sandwiched between the protrusion of the drum and the receiving portion via the carcass sheet. By this sandwiching, the bead core can be prevented from being displaced when the carcass sheet is folded back, the dimensions and shape accuracy of the carcass case can be increased, and a tire having a high uniformity can be efficiently and stably formed.

Further, when the drum can be extended and contracted in the direction of the central axis and the bead support means is moved following the reduction operation, single-stage molding using one drum becomes possible, and the uniformity of the tire can be further increased. Productivity can be further improved.

Further, a winding means for winding both ends of the outer carcass sheet to be attached to the outside of the carcass sheet is provided, and the winding means is provided between the length Lb of the outer carcass sheet and the length La of the inner carcass sheet. Value (Lb−La) / La is 0.2
Under the following conditions, the bead durability of heavy duty tires such as aircraft radial tires can be greatly improved.

The tire manufacturing method enables single-stage molding of the tire by pinching a bead core, expanding and contracting a drum, and the like. The tire manufacturing method according to a third aspect of the present invention includes a winding step of winding both ends of an outer carcass sheet, By setting (Lb-La) / La, it is possible to perform single-stage molding of radial tires for aircraft and the like with greatly improved bead durability.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for producing a tire of the present invention and a method for producing the same
Example of a tire manufactured by the method
A description will be given based on the drawings together with the description of the first embodiment.

In FIG. 1, a tire forming apparatus 1 includes a drum assembly 2 for winding a carcass sheet A for forming a carcass in a cylindrical shape on its outer peripheral surface, and two end portions of the carcass sheet A wound in a cylindrical shape. The drum assembly 2, bead support means 3, and fold means 4 are provided with bead support means 3 for receiving the bead core B, and fold means 4 for turning both end portions of the carcass sheet A around the bead core B.
Are arranged on the hollow central shafts 5, respectively.

As shown in FIG. 3, the drum assembly 2 has a cylindrical drum 9 around which the carcass sheet A is wound around an outer peripheral surface, and a pair of side frames 10 supporting both ends of the drum 9. 10 and so on. The side frame 10 is formed by erecting a disk-shaped side plate 10B on the outer periphery of a bearing portion 10A that can slide along the center axis 5 by being loosely inserted into the center shaft 5, and an outer surface of the side plate 10B. As shown in FIG. 2,
For example, a convex guide 10C for guiding the drum 9 is
Is formed radially around the center.

In this embodiment, the drum 9 is provided with the side plate pieces 10.
B, 10B, each of which has a guide groove guided by the guide 10C at its outer end in the center axis direction.
OB is fixed to the slide piece 12 along the outer surface.

Accordingly, as shown in FIG. 5, each drum piece 11 slides along the guide 10C, so that the diameter of the drum 9 can be increased or reduced. When the diameter is reduced, each drum piece 11
Are brought into contact with each other so that the side plate pieces 1
A dense cylindrical body having substantially the same diameter as OB is formed. In this example, as shown in FIGS. 2 and 3, each drum piece 11 is urged in the radial direction by using a spring piece 13 provided between the bearing 10 </ b> A and the slide piece 12, while the drum 9 is pressed. The diameter is increased by the swelling of a known airbag 14 stored in the inside.

In this embodiment, each of the drum pieces 11 is divided into upper and lower drum pieces 11A and 11B which are overlapped inside and outside in the radial direction, and a lower drum piece 11A is provided on the inner peripheral surface of the upper drum piece 11A. A guide fitted into the guide groove of the portion 11B protrudes. Therefore, in the drum 9, the upper and lower drum pieces 11A and 11B are connected to be able to expand and contract in the overlapping portion.

In the drum assembly 2, the outer peripheral surface of the drum 9 in the contracted state X1 and the extended state Y1 is
A wider carcass sheet A is wound around a straight cylinder. A radially outer side of the straight cylindrical carcass sheet A is located between an outer end of the carcass sheet A and an outer end of the drum 9. , A ring-shaped bead core B is provided. The bead cores B have an inner diameter substantially equal to the outer diameter of the carcass sheet A, and the bead cores B are folded back to both ends of the carcass sheet A by being located more inward in the center axis direction than the outer ends of the carcass sheets A. A protruding portion A1 is formed.

On both sides of the drum assembly 2, receiving portions 19 are provided.
Bead support means 3 is provided below the bead core B.

The bead supporting means 3 includes a bearing 16 slidable along the center shaft 5 by being extrapolated to the center shaft 5, and a body 17 integrally fixed to the bearing 16. And a receiving portion 19 which is held by the body portion 17 via the expanding / contracting diameter moving means 21. The body portion 17 is a cylinder body that connects an inner cylinder 17A fitted and fixed to the outer peripheral surface of the bearing portion 16 and each outer end of an outer cylinder 17B outside thereof with an outer wall 17C. And a plurality of fan-shaped receiving pieces 1 sliding in a radial direction in a plane perpendicular to the center axis 5 between a pair of guide plates 22, 22 raised at respective inner ends of the outer cylinder 17 </ b> B.
Holds a receiving portion 19 made of 9A. The expanding / contracting diameter moving means 21 includes one piston 23 which is loosely fitted in the cylindrical body 17 and slides in the central axis direction, and a plurality of arms pivotally supported by the piston 23 and each of the receiving pieces 19A. 24. Accordingly, as shown in FIG. 6, the expanding / contracting diameter moving means 21 radially moves the receiving piece 19A radially outward through the arm 24 together with the inward movement of the piston 23, thereby expanding the diameter of the receiving portion 19. Can. Accordingly, the receiving portion 19 moves the carcass sheet A in the reduced diameter state Z1.
While waiting in the radially inner side of
In 2, the inner peripheral surface of the bead core B is pressed and held by the outer peripheral surface via the carcass sheet A. In addition, receiving part 19
Has a substantially semicircular concave portion for holding the bead core B at the outer peripheral end thereof. In this example, the receiving portion 19 is in the expanded state Z.
2 so that the outer peripheral surfaces of the receiving piece 19A cooperate with each other to form a dense same circumferential surface, and the tapered receiving piece 19A1 whose both side surfaces S1 gradually approach outward in the radial direction, and vice versa. The receiving pieces 19A2 whose both side surfaces S2 gradually approach inward are alternately combined, and the retreat distance of the receiving piece 19A1 in the reduced diameter state Z1 is larger than the retreat distance of the receiving piece 19A2. The distance between the fulcrums and the fulcrum positions of the arms 24 are different.

On the body 17 of the bead supporting means 3, a holding body 25 for horizontally holding the protruding portion A1 of the carcass sheet A is attached.
A folding means 4 for folding the protruding portion A1 around the bead core B is attached so as to be integrally movable.

The turning means 4 is a bladder in this embodiment, and has one end fixed to the inner surface of the outer guide plate 20 and passing outward on the outer peripheral surface of the receiving portion 19 in the direction of the central axis. The other end, which is stretched and wound inward in a U-shape, is fixed to the holding body 25. Note that a holding plate that keeps the rewind portion of the bladder 4 horizontal is attached to the holding body 25.

The expansion and contraction operation of the drum assembly 2 and the sliding movement of the bead support means 3 in the center axis direction are performed by the moving means 26 in this embodiment.

The moving means 26, as shown in FIG.
A first screw shaft 29 extending in parallel with the central axis 5 and screwing with each of the bearings 16, 16 of the bead support means 3; each of the bearings 10 A extending in parallel with the central axis 5 and of the drum assembly 2;
10A and a second screw shaft 30 to be screwed.

The first screw shaft 29 is connected to the bearings 16, 16
The connector 31 has a connector 31 at the center therebetween, and has a left-handed left-handed screw portion 29A on one side and a right-handed right-handed screw portion 29B on the other side. One end of the first screw shaft 29 is connected to the electric motor M via, for example, a gear G1 or the like. The first screw shaft 29 is inserted without engaging the bearing 10A of the drum assembly 2.

Accordingly, the bead support means 3, 3 is provided by the electric motor M
Can rotate independently of the expansion and contraction of the drum assembly 1 and independently of the connector 31 in directions approaching and moving away from each other.

On the other hand, the second screw shaft 30 similarly has a left-hand thread 30A on one side of the central connector 32 and a right-hand thread 30B on the other side. 16 without being engaged. Then, one end of the second screw shaft 30 is connected via, for example, a clutch 33 or the like.
It is connected to the first screw shaft 29 so that it can be inserted and disconnected.

Therefore, the second screw shaft 3 is operated by the clutch operation.
When 0 is interlocked with the first screw shaft 29, the drum assembly 2 can expand and contract around the connector 32, and in such a case, the first screw shaft 29 interlocks. Thereby, the bead support means 3 can move laterally following the expansion and contraction operation of the drum assembly 2. Each connector 3
An uneven engaging portion 34 for preventing relative lateral displacement is formed at the center of 1 and 32, and the center positions of the drum assembly 2 and the bead supporting means 3 are matched.

Further, in the present invention, on both sides of the drum 9 are formed projections 6 projecting outward in the central axis direction.

As shown in FIG. 8, in the present embodiment, the protruding portion 6 further has a head portion 6B which is curved substantially in an arc shape, further outside a neck portion 6A protruding from the upper portion of the outer surface of the slide piece 12.
The head portion 6B is attached to the outer peripheral surface 9 of the drum 9.
S is smoothly connected to the outer peripheral surface of the neck portion 6A forming the same plane as S.

Accordingly, as shown in FIGS. 9 to 13, the bead supporting means 3 receives the bead core B via the straight cylindrical carcass sheet A formed by the drum 9 in the contracted state X1 and the extended state Y1, as shown in FIGS. It moves alone and inward in the direction of the central axis. In synchronism with this, the diameter of the drum 9 is expanded by the operation of the air bag 14 to an expanded state X2 in which the lower end of the protrusion 6 exceeds the bead core B outward in the radial direction. At the end position W2 of the single movement of the bead support means 3, the center of the bead core B is
e moves inward in the central axis direction of e, and the bead portion of the carcass sheet A is narrowed down.

Further, in this state, the drum 9 is
3, the bead core B is pressed between the protruding portion 6 and the receiving portion 19 via the carcass sheet A and firmly supported. Therefore, even when the bladder 4 is swelled and the protruding portion A1 is folded back in such a support state T of the bead core B, the displacement of the bead core B can be reliably prevented.

Here, as shown in FIG.
Outer diameter Dd of the drum 9 and the bead core B
The ratio Dd / Db to the outer diameter Db of 1.1 or more and 1.5
It is as follows. When the ratio Dd / Db is smaller than 1.1, it is difficult to move the center of the bead core B inward of the protruding edge 6e, so that it is difficult to prevent displacement and the crown height is insufficient, so that the shape of the bead core is insufficient. Carcass cord is disturbed. On the other hand, when the inner carcass is turned over when it is larger than 1.5, the outer carcass is wound under the bead core, and the diameter difference of the circumference at the vertical height of the winding sheet in the tire radial direction is increased. In the direction inside, defects such as wrinkles occur in the carcass,
Molding work becomes difficult. Therefore, in terms of efficiency and quality,
1.1 or more and 1.3 or less are preferable.

In this example, the tire forming apparatus 1 is provided with an outer carcass sheet AA
And a winding means 35 for winding the inner side of the bead core B in the radial direction through the outer surface of the folded portion a1.

In the present embodiment, the winding means 35 is formed of a pressing roller for pressing the outer end portion of the outer carcass sheet AA against the inner carcass sheet A, as shown in FIG.

When such an outer carcass sheet AA is arranged, as shown in FIG. 8, the distance between the projecting edge 6e of the projecting portion 6 and the center of the bead core B in the direction of the central axis. H is set so that the ratio (Lb−La) / La is 0.2 or less, preferably 0.1 or less.

Here, the symbol La indicates the outer peripheral surface 9S of the drum 9.
The radius of the carcass sheet A in the area between the radial line K1 rising radially outward from the end 9e in the central axis direction and the radial line K2 drawn radially inward from the center of the bead core B. The symbol Lb is the curve length of the outer carcass sheet AA in the area.
The ratio (Lb-La) / La of these lengths La and Lb is equal to 0.
When it is 2 or less, the shared load between the inner carcass and the outer carcass can be equalized, and the bead durability can be improved.

As shown in FIGS. 14 and 15, when the bead supporting means 3 and the wrapping means 35 are operated, the side wall rubber 4 for forming the side wall is formed at the starting position W1 of the lateral movement.
0, the position returns to the end position W2, and the receiving portion 19
, One end of the sidewall rubber 40 is pressed against the winding portion aa1.

In the tire forming apparatus 1, the bead support means 3 is further moved inward following the reduction operation of the drum 9 by the operation of the clutch 33, and the carcass sheets A, AA expands into a donut shape, and the carcass sheet is shaped.

As described above, the tire forming apparatus 1 of the present embodiment
A stage P1 in which the carcass sheet A is wound around the outer peripheral surface 9S of the drum 9; a stage P2 in which the carcass sheet A has the protrusion A1 and the bead core B is arranged;
A step P3 of supporting the bead core B by expanding the diameter, a step P4 of holding the bead core B between the protrusion 6 of the drum 9 and the receiving part 19, and a step P5 of folding the protruding part A1 of the carcass sheet A by the bladder 4. And a step P6 of winding both ends of the outer carcass sheet AA, and a step P7 of sping the carcass sheet A. As a result, for example, the radial tire 150A for an aircraft according to the fifth invention shown in FIG. 18 can be formed by a single stage, and the uniformity of the tire can be increased, the bead durability can be improved, and the production efficiency can be improved.

When the wrapping means 35 is omitted from the tire forming apparatus 1 of the present embodiment, the second invention can be implemented, and the tire of the fourth invention shown in FIG. It is possible to efficiently produce the heavy duty tire 50B for trucks and buses with high uniformity.

18 and 19, reference numeral 52 denotes a tread portion, 53 denotes a sidewall portion, 54 denotes a bead portion, and 55 denotes a bead portion.
Indicates a carcass and 56 indicates a belt layer. The belt layer 56
Is formed from a plurality of belt plies 56A in which belt cords are arranged at an angle of 0 to 30 degrees with respect to the tire equator. The carcass 55 in FIG. 18 includes a plurality of carcass sheets A and AA.
A sets the carcass cord at 75-90 with respect to the tire equator.
They are arranged in degrees. The carcass 55 in FIG. 19 includes a plurality of carcass sheets A.

(Specific example) A heavy-duty tire for an aircraft is used in a tire size of 46 × 17R.
At the same time, an overload / cab endurance test, an overload take-off endurance test, and an overpressure test are performed on the prototype tire to measure the endurance strength, and the ratio at that time (Lb-La)
Fig. 2 shows the relationship between / La and the heat generation temperature of the bead portion and the breaking water pressure.
0, 21, and 22 are shown.

(Overload taxi endurance test)
Rated internal pressure (217 psi), rated load (43,195L)
BS) at a constant speed of 2 miles on a test drum with a load of 180% load and a speed of 30 miles / hour.

(Overload take-off endurance test) Rated internal pressure (217 psi), rated load (43,19)
A take-off simulation cycle of an aircraft tire that accelerates on a drum from a speed of 0 to 225 miles / hour under a 150% load (constant) of 5 LBS), so-called FAA
(Federal Aviation Admins
transition) TSO (Technical St)
andrder Order) Universal LST (Lo
ad Speed Time), the bead heat generation level after running the tire using the curve was 100
Were compared.

(Overpressure test) The rim was assembled on a standard rim, water was injected into the tire, and the breaking water pressure until the tire burst (break) was measured.

[0053]

As described above, since the present invention is constructed, both ends of the carcass sheet can be accurately and conveniently turned around the bead core, and the single stage of the radial tire including the tire for aircraft is used. Enables molding.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a tire molding apparatus according to the first invention.

FIG. 2 is an enlarged perspective view showing a part of a drum assembly.

FIG. 3 is a sectional view showing a diameter of a drum assembly and a diameter of a bead supporting means;

FIG. 4 is a sectional view showing expansion and contraction movement and lateral movement of a drum assembly and a bead support means.

FIG. 5 is a schematic diagram illustrating a diameter of a drum to be enlarged and reduced.

FIG. 6 is a schematic diagram illustrating an enlarged / reduced diameter of a receiving portion.

FIG. 7 is a cross-sectional view showing an example of the expanding / contracting diameter moving means.

FIG. 8 is a cross-sectional view illustrating a protrusion of the drum.

FIG. 9 is a schematic cross-sectional view illustrating the operation of the tire molding apparatus.

FIG. 10 is a schematic cross-sectional view illustrating the operation of the tire molding apparatus.

FIG. 11 is a schematic cross-sectional view illustrating the operation of the tire molding apparatus.

FIG. 12 is a schematic cross-sectional view illustrating the operation of the tire molding apparatus.

FIG. 13 is a schematic cross-sectional view illustrating the operation of the tire molding apparatus.

FIG. 14 is a schematic cross-sectional view illustrating the operation of the tire molding apparatus.

FIG. 15 is a schematic cross-sectional view illustrating the operation of the tire molding apparatus.

FIG. 16A is a schematic cross-sectional view illustrating a conventional drum.

FIG. 16b is a schematic sectional view illustrating a conventional drum.

FIG. 17 is a cross-sectional view illustrating a displacement of a bead core.

FIG. 18 is a sectional view showing an example of a heavy duty tire according to the fifth invention.

FIG. 19 is a sectional view showing an example of a heavy duty tire according to the fourth invention.

FIG. 20 is a diagram showing a relationship between a ratio (Lb−La) / La and a bead temperature in an overload taxi durability test.

FIG. 21 is a graph showing a relationship between a ratio (Lb−La) / La and a bead portion temperature in an overload take-off durability test.

FIG. 22 shows a ratio (L) in an overpressure test.
It is a diagram showing the relationship between b-La) / La and the breaking water pressure.

[Explanation of symbols]

 Reference Signs List 2 drum assembly 3 bead support means 4 bladder 5 center axis 6 protruding part 9 drum 19 receiving part 35 winding means A, AA carcass sheet A1 protruding part a1 folded part B bead core

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29D 30/08-30/36 B60C 15/00

Claims (12)

(57) [Claims] 1. A step in which a carcass sheet for forming a carcass is wound around the outer peripheral surface of a drum assembly having a drum provided with an outer peripheral surface having a cylindrical shape and an expandable diameter, and the wound carcass sheet is wound. Disposing a bead core that forms a protrusion in the carcass sheet by being located radially outward and inward of the center axis direction from both ends of the drum assembly; and movably in the center axis direction on both sides of the drum assembly on the same center axis. Supporting the bead core by a receiving portion of a bead supporting means, which is arranged at a position and is movable in the central axis direction, and a protrusion provided on both sides of the drum of the drum assembly and protruding outward in the central axis direction. In a supporting state in which the drum is expanded in diameter and the bead supporting means moves inward in the central axis direction, the bead core is positioned on the inner side in the central axis direction from the protruding end edge, and Sandwiching the bead core with a portion of the carcass sheet via a carcass sheet; disposing the protruding portion of the carcass sheet disposed outside each of the bead support means in the central axis direction by a folding means; and a center axis of the drum. Shaping the carcass sheet whose protruding portion has been turned back by the turning means together with the movement of the bead support means following the reducing operation in the direction. 2. The ratio Dd / Db of the outer diameter Db of the bead core to the outer diameter Dd of the drum in the supported state is 1.1.
Method for producing a tire according to claim 1, wherein the higher and 1.3 or less. 3. A step of winding a carcass sheet for forming a carcass around the outer peripheral surface of a drum assembly having a drum provided with an outer peripheral surface having a cylindrical shape and an expandable diameter, and the wound carcass sheet Disposing a bead core that forms a protrusion in the carcass sheet by being located radially outward and inward of the center axis direction from both ends of the drum assembly; and movably in the center axis direction on both sides of the drum assembly on the same center axis. Supporting the bead core by a receiving portion of a bead supporting means, which is arranged at a position and is movable in the central axis direction, and a protrusion provided on both sides of the drum of the drum assembly and protruding outward in the central axis direction. In a supporting state in which the drum is expanded in diameter and the bead supporting means moves inward in the central axis direction, the bead core is positioned on the inner side in the central axis direction from the protruding end edge, and A method for clamping the bead cores through the carcass sheet the ratio Dd / Db of the outer peripheral diameter Db of the bead core with respect to the outer peripheral diameter Dd of the drum of the supporting state as 1.1 or more and 1.5 or less between parts, said A step of folding the protruding portion of the carcass sheet disposed on each outer side in the center axis direction of the bead supporting means by a folding means; and, in a state where the carcass sheet is wound on a drum and supported by the bladder, the protruding portion is overlapped on the folded carcass sheet. Rolling the outer carcass sheet to be attached by radially inward through the outer surface of the folded portion and inwardly in the radial direction of the bead core by winding means, and a protruding end of the protrusion, The distance in the center axis direction between the center of the bead core and the center of the outer peripheral surface of the drum in the center axis direction passes through the center of the bead core. Ratio of the carcass sheet length La and outside carcass <br/> length La of the carcass sheet for the difference Lb-La and the length Lb of Sushito while leading to a radial line extending radially inward ( Lb−La) / La is 2
0% or less, and shaping the carcass sheet whose protruding portion has been turned back by the turning means together with the movement of the bead supporting means following the reduction operation of the drum in the center axis direction. Tire manufacturing method. 4. A drum assembly having a cylindrical and expandable drum around which a carcass sheet for forming a carcass is wound around an outer peripheral surface; and a drum assembly disposed on the same central axis on both sides of the drum assembly. A bead support that is provided with a receiving portion for receiving a bead core forming a protruding portion in the carcass sheet by being located radially outside and inward of the both ends in the center axis direction of the wound carcass sheet and movable in the center axis direction. And a turn-back means disposed on each outer side in the direction of the center axis of the receiving portion to turn over the protruding portion of the carcass sheet, while protruding outward in the center axis direction on both sides of the drum of the drum assembly. In addition, in the supporting state where the diameter of the drum is increased and the bead supporting means moves, the bead core is located on the inner side in the central axis direction from the protruding end edge. Ri tire molding apparatus a projection capable of clamping the bead cores through the carcass sheet, obtained by forming by Ren'nara the outer circumferential surface between the receiving portion. 5. The tire building apparatus according to claim 4 , wherein said drum is extendable and contractable in a central axis direction. 6. The bead supporting means, wherein the diameter of the receiving portion can be increased to support the bead core by expanding the diameter, and the bead supporting means can be moved independently in the center axis direction and in accordance with the expansion and contraction operation of the drum. The tire molding apparatus according to claim 4, wherein 7. The tire according to claim 6 , wherein the drum shapes the carcass sheet whose protruding portion has been turned back by the turning means together with the movement of the bead support means following the reduction operation of the drum. Molding equipment. 8. The ratio Dd / Db of the outer diameter Db of the bead core to the outer diameter Dd of the drum in the supported state is 1.1.
The tire molding apparatus according to claim 4, wherein the ratio is not less than 1.5 and not more than 1.5. 9. An outer carcass sheet wound around a drum and attached to a carcass sheet having the protruding portion folded back by a bladder in the support state, the radius of the bead core passing through the outer surface of the folded portion. Outer diameter Db of the bead core with respect to the outer diameter Dd of the drum in the supported state.
The ratio Dd / Db of 1.1 to 1.5 is defined as the distance between the projecting edge of the projection and the center of the bead core in the direction of the central axis. The length of the carcass sheet relative to the difference Lb-La between the length La of the carcass sheet and the length Lb of the outer carcass sheet from the end in the direction to the radius line extending inward in the radial direction through the center of the bead core The tire molding apparatus according to claim 4 , wherein a ratio (Lb-La) / La to La is set to be 20% or less. 10. The outer diameter Dd of the drum in the supported state.
Ratio Dd / Db of the outer diameter Db of the bead core to 1.
5. The method according to claim 4 , wherein the number is not less than 1 and not more than 1.3.
The tire molding apparatus as described in the above. 11. An outer carcass sheet wound around a drum and attached to a carcass sheet having the protruding portion folded back by a bladder in the support state, and passing through the outer surface of the turned portion to a radius of the bead core. Outer diameter Db of the bead core with respect to the outer diameter Dd of the drum in the supported state.
The ratio Dd / Db is set to 1.1 or more and 1.3 or less, and the distance in the central axis direction between the projecting edge of the projection and the center of the bead core is set to the central axis of the outer peripheral surface of the drum. The length La of the carcass sheet from the end of the carcass sheet to the radius line extending inward in the radial direction through the center of the bead core and the outside
The ratio of the carcass sheet of the carcass sheet for the difference Lb-La and the length Lb of the length La (Lb-La) /
The tire forming apparatus according to claim 4, wherein La is set to be equal to or less than 20%. 12. A tire according to any one of claims 1 to 3.
The tire manufactured by the manufacturing method of 1.