JP2002347135A - Tire manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire manufacturing method which can surely form tire constituent members all the time having a specified shape and dimension without increasing the number of joints or the like, greatly improve uniformity and balance of product tires in addition to the operation efficiency in tire molding, and also effectively suppressing the product tires from containing air and the generation of a bare or the like. SOLUTION: A raw tire is molded on the rigid rotation support body 1 having an outer periphery face shape corresponding to the inner periphery shape of a product tire, while the raw tire is vulcanized on the rotation support body in this tire manufacturing method,. When the raw tire is molded, unvulcanized rubber strips 4, 6 having a cross section corresponding to the cross section of a tread 3 or parts thereof 5, 7 is wound round the outer periphery of the rotation support body 1 under rotation while being overlapped at least at a part of a width direction to form treads 3 or a part thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a tire, especially a radial tire, and sufficiently satisfies the conditions such as shape, size, and material required for various tire components, and achieves high molding accuracy. It is possible to mold a green tire having the following.

[0002]

2. Description of the Related Art In the manufacture of tires, particularly in the molding of raw tires, various rubber-made tire components formed in advance and supplied from a previous process are sequentially wound and pasted on a molding drum. Conventionally, it has been widely and generally practiced to variously deform the tire constituent members by folding or shaping the end portion of the carcass band.

[0003]

In recent years, as the performance of tires has become higher, the cross-sectional shape and the like required for the tire components have become more complicated. When wound on a forming drum, due to the complexity of the three-dimensional shape, the winding position and shape accuracy decrease due to the influence of the inner and outer circumference length differences and other effects, and the joint shape collapses on the forming drum, etc. Thus, there has been a problem that the uniformity of the tire is reduced and the balance is deteriorated.

[0004] On the other hand, the cross-sectional shape of a tire component is limited by a rubber molding apparatus in a previous process for molding the same, and therefore, it may not be possible to integrally mold a tire as intended. In order to achieve the desired shape, when the component is divided into multiple parts,
As the number of parts increases, the number of winding steps on the molding drum increases, and the number of joints on the molding drum also increases, which lowers the efficiency of molding of raw tires and reduces the production efficiency of product tires. However, there was a high possibility that defects such as infiltration and bareness would occur.

SUMMARY OF THE INVENTION An object of the present invention is to solve such problems of the prior art, and it is an object of the present invention that the cross-sectional shape of a tire component is complicated. Even if it is not necessary to make it a divided structure, tire constituent members of the expected shape and dimensions can be produced without increasing the number of joints, even when they are made of multiple types of rubber materials, for example. It can always be formed reliably, and there is no risk of deterioration in position and shape accuracy due to winding of the tire component itself formed in advance, and in addition to the tire molding work efficiency, uniformity and uniformity of the product tire The balance can be greatly improved, and due to the presence of a large number of joints and the like of the tire constituent members, air entering the product tire,
An object of the present invention is to provide a method for manufacturing a tire that can effectively suppress the occurrence of bears and the like.

[0006]

According to the present invention, a green tire is molded on a rotating support having an outer peripheral shape corresponding to the inner peripheral shape of a product tire, and the raw tire is molded on the rotating support. A method for producing a tire to be vulcanized, wherein at least one kind of tire constituent member, for example, an inner liner, a bead filler, a side reinforcing layer, a side wall, a tread, a rubber chafer, a cushion rubber and the like is used in molding a green tire. For each type, an unvulcanized rubber strip having a cross-sectional shape corresponding to the whole or a part of the cross-sectional shape is overlapped on the outer peripheral surface thereof at least partially in the width direction under the rotation of the rotating support. It winds and constitutes a tire constituent member or a part thereof.

[0007] In this method, a width of 5 to 30 m, formed by an extruder, an injection extruder, a constant volume extruder, or the like, is formed on an outer peripheral surface of a rotary support, which is mainly made of a rigid material.
m and a thickness of about 0.2 to 5 mm are wound around an unvulcanized rubber strip to form the required tire components directly on the rotating support, thereby making the tire components complicated. Even if it has a cross-sectional shape, it is easy and easy to obtain the expected tire component without being restricted by the rubber molding device and the like and without increasing the number of parts, and excellent. It can be formed with high precision under molding efficiency. This is the case when forming only a part of a tire component having a shape that is difficult to integrally mold in the previous process or that is difficult to wind and attach on a forming drum by winding lamination of strips or the like. The same is true for

Here, the tire component is formed in advance by directly winding the strip at a desired position on the rotating support, and the formed body is wound and pasted on a forming drum. Compared to the case of wearing, while being able to bring much better position and shape accuracy, it is possible to effectively prevent the occurrence of joints, and as a result, while greatly improving tire molding work efficiency, Product tire uniformity and balance can also be greatly improved.

In addition, in this case, since the tire component or a part thereof is formed by directly winding the unvulcanized rubber strip, even if the tire component is made of two or more types of rubber materials, the required component is required. By sequentially winding the rubber strips at required locations, the instability of the shape and the like can be sufficiently removed.

[0010] On the other hand, according to this method, the rubber strip may be wound and laminated in a complicated cross-sectional shape, or may be wound and laminated in multiple layers, whereby air may be trapped in a green tire. Some irregularities may remain on the supination surface, but when vulcanizing the green tire molded on a rotating support made of rigid material on the rotating support, it is vulcanized together with the rotating support. The raw tire is pressed against the surface of the vulcanization mold with a much larger force than when a conventional bladder is used, so that any special deformation or the like is performed on the wound-formed tire components. Vulcanization can be carried out without causing the vulcanization to take place while maintaining the complex shape of the tire components, as well as forcing residual air into the raw tire and its surface irregularities out of the mold. It is possible to output, without internal defects, can provide sufficient homogeneous product tire throughout.

[0011] Thus, according to this method, by winding the unvulcanized rubber strip on the rotating support, the tire component or a part thereof may have a complicated cross-sectional shape even if it has a complicated cross section. Also, at the required position, with the expected shape and dimensions, it can be easily and efficiently formed, and from the tire component or a part thereof, the circumferential joint can be removed, In addition, the tire components and the like once formed can be vulcanized and molded without damaging the shape and the like.

[0012] On the other hand, the remaining of the air in the raw tire, the surface irregularities of the tire constituent members, and the like caused by the winding of the rubber strip are reduced by the rotation of the raw tire on the rotating support. This can be adequately dealt with by pressing the vulcanization mold with a large force.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a main part schematic cross-sectional view showing a molding mode of a green tire in a case where a tread as an example of a tire component is formed by winding and laminating an unvulcanized rubber strip. An inner liner, a carcass, a bead filler, a belt, and the like are previously disposed on a rotating support 1 made of a material by an appropriate method, and a tread 3 is formed on the outer peripheral side of the belt 2.

This is made of a specific type of rubber material. For example, one type of unvulcanized rubber strip 4 extruded from a constant volume extruder and formed to a required cross-sectional dimension by a roller die is formed on the belt 2. FIG. 1 (b) shows a required tread structure in a product tire by spirally winding the belt so as to cover the entire width of the belt while overlapping a part in the width direction on the peripheral surface. Thus, the base tread layer 5 located on the inner peripheral side of the tread 3 is formed, and then the unvulcanized rubber strip 6 made of another type of rubber material is covered so as to cover the entire width of the base tread layer 5. Similarly, by spirally winding and laminating the cap tread layer 7 to a required thickness to form the cap tread layer 7, the required tread 3 having a cap-base structure is formed.
It constitutes.

Here, by appropriately selecting the cross-sectional shape of the rubber strips 4, 6, the base tread layer 5 and the cap tread layer 7, which have the desired shape and dimensions, and the tread, 3 can be formed easily and easily with high precision without the need for a pre-forming step or the like and without the presence of a joint portion. Here, the tread can also be formed by winding and laminating only one type of unvulcanized rubber strip, and this can also provide the same operation and effect as described above.

FIGS. 2 to 4 are schematic cross-sectional views of essential parts showing another example of the structure of the tread. FIG. 2 shows a base tread layer 5 in comparison with that shown in FIG. The rubber strips 4 and 6 are spirally wound at least partially in the width direction so as to have a narrow width and a central portion in the width direction exposed on the surface of the cap tread layer 7. The tread 3 is obtained by laminating it twice.

In FIG. 3, the rubber strip 4 is wound so that the base tread layer 5 becomes thicker in a cross section in the width direction toward the center in the width direction. The tread 3 is formed by forming a cap tread layer 7 by winding a rubber strip 6 around the base tread layer 5 so as to surround the base tread layer 5, and the configuration shown in FIG. On the same base tread layer 5 as above, a third unvulcanized rubber strip 9 is wound and laminated in an intermediate height to form an intermediate tread layer 9, and
The unvulcanized rubber strip 6 is wound and laminated so as to completely cover the base tread layer 5 and the intermediate tread layer 9 to obtain the tread 3 having a required sectional shape. In any case, the layers 5, 7, and 9 can be easily formed with high precision, as in the case shown in FIG.

FIG. 5 is a view showing a molding mode of a green tire in a case where a sidewall is formed.
The three types of unvulcanized rubber strips 11, 12, and 13 are wound around and adhered to the outermost side surface of the rotary support 1 to form the sidewalls 14.

FIG. 6 shows that the inner liner 15 is formed by winding an unvulcanized rubber strip 16 and is adjacent to the outer side of the inner liner 15 and inward of the carcass. FIG. 7 is a view for forming a side reinforcing layer 18 which is a winding of the strip 17.
On each of the inside and outside of the carcass 19, each of the unvulcanized rubber strips 20 and 21 of a different type is wound from the outer peripheral side of the bead core 22 radially outward to be adhered, and A further unvulcanized rubber strip 23 different from any of the rubber strips 20 and 21 is further rolled and adhered to the outer side in the radial direction of the rubber strip 21 wound around the bead filler 24.
It constitutes. In any of these cases, the rubber strips 11, 1 on the rotary support 1 are used.
By the winding molding of 2,13,16,17,20,21,23, the expected operation and effect can be obtained. By the way, the side wall 14 shown in FIG.
It is a matter of course that the bead filler 24 shown in FIG. 7 can be entirely constituted by the same type of unvulcanized rubber strip.

After the green tire is molded on the rotary support 1 as described above, the green tire is loaded together with the rotary support 1 into a vulcanization mold 25 as shown in FIG. And vulcanize.

According to this, the rotary support 1 made of a rigid material can press the green tire 26 against the surface of the vulcanization mold 25 with a large force when the vulcanization mold 25 is clamped. Air remaining in the green tire due to the wound lamination or the like is efficiently discharged out of the mold. Therefore, in this case, the occurrence of air in the product tires, generation of bears, and the like are effectively prevented.

[0022]

Thus, according to the present invention, the unvulcanized rubber strip is wound on the rotating support having the outer peripheral surface shape corresponding to the inner peripheral surface shape of the product tire, and the required tire components or By forming a part of it, it can be formed simply and easily in the required position and in the expected shape and dimensions, and with high precision without joints, thus When formed, the tire components and the like on the rotating support having substantially the same shape, dimensions, and the like as the tire components and the like of the product tire, the raw tire, upon loading into the vulcanization mold, the shape and the like Since it is not damaged, a product tire having high dimensional accuracy and sufficiently uniform in the circumferential direction can be provided.

Here, the pressing force of the green tire against the surface of the vulcanized mold can be sufficiently increased by the rotating support, so that air which may remain in the green tire can be efficiently removed from the mold. Ejection can be performed, which is particularly effective when the rotating support is preheated to bring the mold cavity volume close to that at the start of vulcanization.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a main part of a tire tread in a width direction showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating another configuration example of the tread.

FIG. 3 is a diagram showing another configuration example of the tread.

FIG. 4 is a diagram showing still another configuration example of the tread.

FIG. 5 is a schematic cross-sectional view of a main part of a side wall in a width direction showing an embodiment of the present invention;

FIG. 6 is a schematic cross-sectional view of a main part in a width direction showing an embodiment of an inner liner and a side reinforcing layer.

FIG. 7 is a schematic cross-sectional view of a principal part in a width direction showing an embodiment of a bead filler;

FIG. 8 is an essential part schematic cross-sectional view showing a vulcanization state of a raw tire on a rotating support.

[Explanation of symbols]

1 rotating support 2 belt 3 tread 4,6,8,11,12,13,16,17,20,2
1, 23 Unvulcanized rubber strip 5 Base tread layer 7 Cap tread layer 9 Intermediate tread layer 14 Side wall 15 Inner liner 18 Side reinforcement layer 19 Carcass 24 Bead filler 25 Vulcanized mold 26 Raw tire 27 Cavity

Claims (4)

[Claims] 1. A method of manufacturing a tire, comprising molding a green tire on a rotating support having an outer peripheral surface shape corresponding to an inner peripheral surface shape of a product tire, and vulcanizing the raw tire on the rotating support. In molding a green tire, an unvulcanized rubber strip having a cross-sectional shape corresponding to the cross-sectional shape of a tire component or a part thereof is formed on an outer peripheral surface thereof under rotation of a rotating support. A method for producing a tire which is wound while overlapping at least a part of the direction to constitute a tire constituent member or a part thereof. 2. The method for producing a tire according to claim 1, wherein two or more types of unvulcanized rubber strips are sequentially wound to form a tire component or a part thereof. 3. The tire constituent member is an inner liner, a bead filler, a side reinforcing layer, a side wall, a tread, a rubber chafer, or a cushion rubber.
Or the method for producing a tire according to 2. 4. The method for producing a tire according to claim 1, wherein the green tire molded on the rotary support is charged into a vulcanization mold together with the rotary support and vulcanized.