JP2001001416A - Former for forming green tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conveniently and quickly replace a bladder. SOLUTION: A forming drum is provided with inner and outer bladder units 6 and 7 to be replaceable independently on both faces of a cylinder 5 in the axial direction. An outer section 3A of a tire member is raised when a medium is transferred by an inner bladder unit 6 to fix an inner bladder 11 to be set along a green tire main body TB raised between bead cores 4, 4 on both inner peripheral edges 11i and 11o of the inner bladder. An outer bladder 20 pressing the inner bladder 11 from outside is fixed on both inner peripheral edges 20i and 20o of the outer bladder by an outer bladder unit 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a green tire molding foamer in which an axially outer portion of a cylindrical tire member formed on a molding drum is wound around a bead core using inner and outer bladders.

[0002]

2. Description of the Related Art In forming a raw tire T, as shown schematically in FIG. 5A, a sheet-shaped inner liner rubber, a side wall rubber, a carcass, etc. are wound around a forming drum a to form a cylindrical tire member. b, and an outer portion b1 of the tire member b in the axial direction outside the bead core c.
Is wound around the bead core c and is attached to the inner portion b2 of the tire member b.

[0003] Further, as this winding means, a means using two bladders ei and eo arranged side by side in and out in the axial direction is known. In this apparatus, first, the inner bladder ei is expanded into a toroidal shape, the outer portion b1 is bent at a substantially right angle to rise, and then the outer bladder eo is expanded to press the inner bladder ei from the outside. As a result, the outer portion b1 is strongly pressed against the inner portion b2, and a strong attachment is performed.

On the other hand, the bladders ei and eo are shown in FIG.
As shown in (B), the inner peripheral edges ei1, ei2, eo1, of the bladders ei, eo are used by using a plurality of clamp rings f.
eo2 is sandwiched between the adjacent clamp rings f, f, and is integrally fixed as one unit.

[0005]

Therefore, even if one of the bladders ei and eo fails due to a puncture or the like, the handling is inferior, for example, it is necessary to disassemble the entire unit and replace the failed bladder. With
For example, it takes a long time to disassemble and assemble the unit, so that the apparatus is stopped for a long time, which impairs the productivity of raw tires.

Accordingly, the present invention is based on the fact that the inner and outer bladders are formed of independent units and each unit can be replaced independently, so that the structure itself of each unit can be simplified and It is an object of the present invention to provide a green tire molding foamer which can expedite and expedite the replacement of bladders by disassembling and assembling only the unit, and can solve the above problems.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a cylindrical tire member including a carcass laminated and formed on a forming drum is formed in an axial direction of the tire member. A raw tire molding foamer that expands in a toroidal shape while forming a winding portion that winds an axially outer portion than a bead core disposed at both ends, wherein the molding drum is a central cylindrical portion that expands and contracts in the axial direction, and An inner bladder unit which is arranged on both sides in the axial direction and is inflated in a toroidal shape with the filling of the medium to raise the winding portion and to fix the inner bladder along the raw tire body rising between the bead cores at both inner peripheral edges thereof. And an outer bladder unit fixing both inner peripheral edges of an outer bladder that presses the inner bladder from the outside by swelling side by side on the outside thereof, or The inner and outer bladder units are independently replaceable.

In the invention of claim 2, the axial center position between the inner peripheral edges of the outer bladder is located near the axial width central position of the inner bladder in a state in which the winding portion rises by expanding. It is characterized by being located.

According to the third aspect of the present invention, the outer bladder unit discharges a medium by pressing the outer bladder against the outer peripheral end of a ring for fixing the inner peripheral edge of the outer bladder by the inner bladder. Notched grooves are formed to prevent the interruption of the operation.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2, a green tire forming foamer 1 of the present application includes a forming drum 2, and cylindrical tire members 3 formed on the forming drum 2 are arranged at both axial ends of the tire member 3. The portion 3A outside the bead core 4 in the axial direction is wound up and expanded into a toroidal shape while forming a winding portion TA, whereby a green tire T is formed.

Here, the tire member 3 is formed by laminating a sheet-like tire component such as inner liner rubber, chafer rubber, sidewall rubber, and carcass on a forming drum 2 in a cylindrical shape. It is.

The forming drum 2 is provided with a central cylindrical portion 5 capable of making the bead cores 4 approach each other by expanding and contracting in the axial direction. It includes inner and outer bladder units 6 and 7 that are independently replaceable.

The central cylindrical portion 5 has substantially the same configuration as that of the prior art. For example, the central cylindrical portion 5 includes left and right side plate portions 5A and 5A which can slide in the axial direction along a hollow main shaft 9, and has the side plate portions. 5A and 5A move toward and away from each other by, for example, forward and reverse rotation of a screw shaft (not shown) passing through the inside of the support shaft 9.

Accordingly, the central cylindrical portion 5 supplies the filling medium (air in this example) to the inside while the space between the side plate portions 5A and 5A is brought close to each other, thereby forming the inside of the cylindrical tire member 3 inside. The portion 3B can be expanded and raised in a toroidal shape. Then, the cylindrical tread ring 1 in which the inner portion 3B is made to stand by on the outer side in the radial direction.
A green tire main body TB is formed by pressing and joining the raw tire main body TB. The tread ring 10 is formed by attaching a cord layer such as a belt or a breaker and tire components such as tread rubber inside and outside the radial direction.

Next, the inner bladder unit 6 is inflated in a toroidal shape with the filling of the filling medium (in this example, air), whereby the winding portion TA, which is the outer portion 3A, is started up and the raw tire is raised. A bladder 11 along the main body TB, and both inner peripheral edges 11 of the bladder 11 therein.
i, 11o.

As shown in FIG. 3, the case 12 is slidably inserted outside the main shaft 9 and the side plate 5A.
And a case main body 13 that can be attached to and detached from the main body.

The case body 13 is provided with the central cylindrical portion 5.
A case main portion 13A having a seating portion 14 on the outer periphery of which the bead core 4 is seated, and a small-diameter sub-portion connected to an axially outer end of the case main portion 13A via a step 15; 13B. In this example, the outer portion 13B has an outer bladder unit 7 on its outer periphery.
Is provided with a supporting portion 16 for freely mounting / removing the.

Inner and outer fixing rings 17i and 17o are provided on the inner and outer end faces of the case main portion 13A in the axial direction.
However, it is detachably and integrally attached by, for example, a bolt fitting or the like. The inner peripheral edges 11i and 11o of the inner bladder 11 are sandwiched and fixed between the inner end face and the inner fixing ring 17i and between the outer end face and the outer fixing ring 17o. In this example, a case where fitting recesses for fitting and holding the inner peripheral edges 11i and 11o are provided on the inner end face and the outer end face is illustrated.

Further, the case body 13 is connected to a supply source (not shown) of the filling medium, and has openings at respective positions on the outer periphery of the case main portion 13A and inside and outside the seat portion 14 in the axial direction. A medium passage 19 (shown in FIG. 3) is formed.

Accordingly, by supplying the filling medium through the medium flow path 19, in this example, the inner part 11A and the outer part 11B of the inner bladder 11 that are folded inside and outside the bead core 4 are provided. Can be expanded respectively. Thereby, not only can the raised portion TA be raised along the raw tire body TB by the outer portion 11B, but also the bead portion can be pressed down strongly from both sides to accurately form the bead portion.

Next, the outer bladder unit 7 includes an outer bladder 20 that swells to press the inner bladder 11 from the outside, and a case 21 that fixes both inner peripheral edges 20i and 20o of the outer bladder 20. With

The case 21 includes three inner, middle, and outer rings 22i,
2m, 22o, and each ring 22i, 22m, 2m
2o is detachably and integrally connected by, for example, a bolt. And this ring 22i, 22m
Outer bladder 2 between the rings and between the rings 22m and 22o
The inner peripheral edges 20i and 20o of the “0” are sandwiched and fixed, respectively. In this example, a case is described in which the rings 22i and 22m are provided with fitting recesses for fitting and holding the inner peripheral edges 20i and 20o.

The case 21 is connected to a filling medium supply source (not shown),
A medium flow path 23 (shown in FIG. 3) that opens on the outer periphery of m is formed.

Therefore, when the filling medium is supplied through the medium flow path 23, the outer bladder 20 is expanded, and the inner bladder 11 is pressed from the outside, so that the raised winding section TA can be further expanded. It can be pressed against the tire main body TB with a strong force, and a strong sticking can be performed.

Here, in the present embodiment, as shown in FIG. 2, the axial center position P between the inner peripheral edges 20i and 20o of the outer bladder 20 is in a state where the hoist TA is raised, that is, the inner and outer bladders 11, In the inflated state, the bladder 11 is located near the center position Q of the axial width W of the inner bladder 11. Thereby, the winding portion T
The pressing force of A to the tire main body TB can be most effectively increased, and more firm attachment can be achieved. Further, the setting of the center position P also has an effect of applying the pressing force to a higher position, that is, to a height position near the tread end of the raw tire main body TB, and thereby substantially the entire winding portion TA, It is possible to securely adhere.

The specified pressure in the inflated state for measuring the center position Q is 1 to 3 kg / cm ² .
The green tire is formed in the range of 1 to ³ kg / cm ² . The term “near the center position Q” means an area around the center position Q and not more than 10% of the width W. That is, the distance L between the center positions P and Q is 10 times the width W.
%, Preferably 5% or less, more preferably 3% or less.

If the distance L exceeds 10%, the outer bladder 20 does not function sufficiently, and the pressing force is reduced.
And the height region where this pressing force acts tends to be significantly reduced.

Further, in this embodiment, when the filling medium in the bladders 11 and 20 is exhausted after the green tire is formed, the outer bladder 20 is pressed by the inner bladder 11, whereby the exhaust of the outer bladder 20 is interrupted. As shown in FIG. 4, a notched groove 24 is formed in the inner ring 22m for the purpose of preventing such a situation.

The notch groove 24 is formed in the ring 22
formed by notching the outer peripheral end of m in the axial direction,
For example, a groove having a rectangular cross section is formed at one or more locations, preferably 4 to 6 locations, on the outer periphery. In this embodiment, the medium flow path 23 is opened by a notch groove 24. This is because, at the time of evacuation, the outer bladder 20 is strongly pressed against the end face of the inner ring 22m by the pressing force F due to the expansion of the inner bladder 11 and hermetically sealed, and the filling medium in the outer bladder 20 is removed. There is a tendency for it not to be exhausted. However, a gap is formed by the formation of the notch groove 24, and exhaust is performed from this portion.

Reference numeral 25 in the drawing denotes a holding cylinder that holds the bladders 11 and 20 that are folded by exhaust and supports them in a cylindrical shape, and is attached to the outer ring 22o.

[0031]

As described above, according to the present invention, the inner and outer bladders are formed as independent units, and each unit can be replaced independently. Therefore, the structure itself of each unit can be simplified. Moreover, even if one of the bladders breaks down, the replacement work can be expedited and expedited, for example, by disassembling and assembling only the unit on the faulty side.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a green tire forming foamer according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a state where each bladder is expanded.

FIG. 3 is a sectional view showing inner and outer bladder units.

FIG. 4 is a partial cross-sectional view illustrating a notched groove.

FIG. 5A is a diagram illustrating a method for molding a green tire, and FIG. 5B is a cross-sectional view illustrating a conventional bladder mounting structure.

[Explanation of symbols]

 Reference Signs List 2 forming drum 3 tire member 3A outer portion of tire member 4 bead core 5 bladder unit in central cylindrical portion 6 bladder unit in outer 11 bladder in 11i, 11o inner peripheral edge of bladder in 20 outer bladder 20i, 20o outer Inner peripheral edge of bladder 22o ring 24 Notch groove P, Q Central position TA Winding section TB Raw tire body

Claims (3)

[Claims] 1. A cylindrical tire member including a carcass laminated on a forming drum is formed with a winding portion which winds an outer portion in an axial direction outside a bead core disposed at both axial ends of the tire member. A raw tire forming foamer to be inflated in a toroidal shape, wherein the forming drum is provided with a central cylindrical portion that expands and contracts in the axial direction, and is disposed on both sides in the axial direction, and expands in a toroidal shape together with a medium filling to form the winding portion. A bladder unit in which the inner bladder is fixed at both inner peripheral edges of the inner bladder that rises and is raised along the raw tire body rising between the bead cores, and the outer bladder that presses the inner bladder from the outside by being swelled side by side on the outside. The bladder includes an outer bladder unit having both inner peripheral edges fixed thereto, and the inner and outer bladder units are independently replaceable. Green tire molding Fuoma characterized. 2. An axial center position between said inner peripheral edges of said outer bladder is located near an axial width central position of said inner bladder in a state in which a raised portion is raised by swelling. The green tire molding foam according to claim 1. 3. The outer bladder unit has a notch at an outer peripheral end of a ring for fixing the inner peripheral edge of the outer bladder to prevent interruption of medium discharge due to the outer bladder being pressed by the inner bladder. 3. The green tire molding foamer according to claim 1, wherein a groove is formed.