JP3370282B2 - Rubber member for tire and tire using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire rubber member such as tread rubber capable of improving productivity and a tire using the same.

[0002]

2. Description of the Related Art A conventional rubber member for a tire, for example, a tread rubber g1 as shown in FIG. 10, is usually continuous from a rubber extruder or the like with a predetermined finished sectional shape. It was extruded and molded integrally. The finished cross-sectional shape of such a tread rubber g1 is
It is determined by a die or the like attached to the extruding end of the extruder. Therefore, when the size of the tread rubber g1 varies depending on the tire size, the type of tire, etc., it is necessary to prepare as many bases as the number of the types, and when molding tread rubbers g1 having different sizes, Each time, it is necessary to replace or adjust the die of the extruder, and in particular, in recent years, when there is a strong tendency for high-mix low-volume production, the production efficiency becomes very poor.

On the other hand, as shown in FIG. 11, for example, it has been proposed to form a tread rubber g2 having a desired finished sectional shape by successively winding a ribbon-shaped unvulcanized rubber s in the tire circumferential direction. However, in such a method, since the ribbon-shaped rubber s is wound from the beginning to the end, the time required for winding is increased, and improvement in productivity cannot be expected so much. If the cross-sectional area of the ribbon-shaped rubber s is increased in order to reduce the number of windings, the number of windings can be reduced, but it becomes impossible to obtain a tread rubber having a complicated finished cross-sectional shape.

Such a problem is also caused in forming not only tread rubbers but also various rubber members for tires such as sidewall rubbers, inner liner rubbers, bead apex rubbers, clinch rubbers, chafer rubbers and belt cushion rubbers. The same happens.

The present invention has been devised in view of the above situation, and a base portion of a rubber member for a tire is formed by connecting a rubber member for a tire to a ring of extruded rubber extruded products. The rubber strip is wound around the outer peripheral surface of the base portion in a circumferential direction and in a spiral shape to form a finished cross section of the rubber member for a tire. It is an object of the present invention to provide a rubber member for a tire that can improve the tire life and a pneumatic tire using the same.

[0006]

According to a first aspect of the present invention, there is provided a base portion of a rubber member for a tire, which is formed by continuously forming rubber extrusions integrally extruded into a ring shape, and a base portion of the base portion. A rubber member for a tire, which comprises a rubber strip wound around the outer peripheral surface in a circumferential direction and spirally, and a laminated portion forming a finished cross section of the rubber member for a tire.

The invention according to claim 2 is the rubber member for a tire according to claim 1, wherein the base portion has an area of 30 to 50% of the area of the finished cross section.

Further, the invention according to claim 3 is the rubber member for a tire according to claim 1 or 2, which is a tread rubber, a sidewall rubber, an inner liner rubber, a bead apex rubber, a clinch rubber, a chafer rubber or a belt cushion rubber.

The invention according to claim 4 is the rubber member for a tire according to claim 3, characterized in that the tread rubber includes a tread rubber for rehabilitation arranged in a tread portion of a tire for rehabilitation. .

The invention according to claim 5 is a tire using the rubber member for a tire according to any one of claims 1 to 4.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. Rubber member G for tire of the present embodiment
As shown in FIG. 1, inside the tread rubber G1 disposed in the tread portion 10 of the tire raw cover 1 before vulcanization, the sidewall rubber G2 disposed in the sidewall portion 11, and the toroidal radial carcass 13 Inner liner rubber G3 that does not easily permeate the air that is arranged, hard bead apex rubber G4 that is arranged inside the bead portion 12, clinch rubber G5 that is arranged on the outer surface of the bead portion 12 and has excellent wear resistance, or the tread portion. A belt cushion rubber G6 or the like arranged on the tire axial direction outer side and the tire radial direction inner side of the belt layer 14 that reinforces 10 may be included, and although not shown, the clinch rubber is used in the bead portion of the heavy-duty tire and the like. It also includes a separately provided chafer rubber and the like.

As shown in detail in FIG. 2, the tire rubber member G of the present invention, for example, the tread rubber G1, is a tire rubber formed by connecting unvulcanized rubber extruded products 2 integrally extruded in an annular shape. The base member 3 of the member and the laminated portion 5 that forms a finished cross section of the tread rubber G1 (rubber member for tire) by winding a rubber strip 4 around the outer peripheral surface 3a of the base member 3 in a circumferential direction and in a spiral shape. It

Thus, the tread rubber G1 of this embodiment
Then, since the base portion 3 is made of the extruded rubber extruded product 2 integrally, it is possible to reduce the man-hours for winding the rubber strip 4 as compared with the tread rubber g2 shown in FIG. Productivity is improved by forming G1. It is also possible to manufacture a complicated tread rubber G2 in a short time by using the rubber strip 4 having a small cross-sectional area. Further, by using an inexpensive rubber composition for the rubber extruded product 2, a significant cost reduction can be achieved.

A rubber extruded product 2 constituting the base member 3
Is an unvulcanized rubber material obtained by mixing a natural rubber or a synthetic rubber with a rubber compounding agent such as a vulcanizing agent or a filler, and having a die having a predetermined extrusion cross-sectional shape, for example, a screw type extruder. Is extruded from the die. The term "extrusion molding" as used herein also includes calender roll-type molding capable of molding rubber into a predetermined shape by utilizing a gap between a pair of rolls. Further, the rubber extruded product 2 is 1 in this example.
Although a rubber composition made of two kinds of rubber compositions is illustrated, two or more kinds of rubbers may be overlapped. In this case, a known multi-screw extruder or the like may be used to integrally perform extrusion molding.

In the present embodiment, the base portion 3 of the tread rubber G1 is exemplified by a substantially trapezoidal shape having a horizontally long cross section, but the shape is not particularly limited, and various shapes are available. Can be adopted. Further, it is desirable that the base portion 3 has an area of 25 to 60%, and more preferably 30 to 50% of the area of the finished cross section of the tread rubber G1, and thereby the work of winding the rubber strip 4 can be more reliably reduced. Can be done.

The "finished cross-sectional shape" is the cross-sectional shape required for each rubber member when manufacturing the raw cover 1 of the tire, and the cross-sectional shape of each rubber member that appears in the tire after vulcanization. different.

It is desirable that the width or thickness of the rubber extruded product 2 be determined so that it can be shared by tread rubbers having different sizes or shapes shown in FIGS. As a result, the versatility of the rubber extruded product 2 is increased, and the number of types of die of the rubber extruder is significantly reduced as compared with the conventional tread rubber in which a die having a cross-sectional shape different for each size is required in manufacturing. In addition, the troublesomeness of the replacement work is eliminated, so that the facility cost can be reduced and the productivity can be further improved.

Further, the extruded rubber extruded product 2 is cut into a predetermined length corresponding to one tire, and then sent through a servicer or the like to a molding former F capable of expanding and contracting as shown in FIG. 4, for example. The former F is wound around the former F and joined at both ends j to form an annular base portion 3. At this time, the belt layer 14 and other reinforcing layers may be arranged in advance between the base portion 3 and the former.

In the present embodiment, the rubber strip 4 is made of an unvulcanized rubber composition having a narrow width and a small thickness, and may be the same as the rubber composition of the rubber extruded product 2. It may also be different. The rubber strip 4 has a cross-sectional area smaller than that of the rubber extruded product 2. More specifically, the rubber strip 4 preferably has a thickness of, for example, 0.5 to 2 mm and a width of, for example, 10 to 50 mm, but can be variously changed according to the type of tire. Further, the cross-sectional shape of the rubber strip 4 is a laterally long rectangle in this example, but various and preferable shapes such as a trapezoidal shape and one having a small thickness at both ends in the width direction can be adopted depending on the finished cross-sectional shape of the member.

In the present embodiment, the rubber strip 4 has its winding start end 4A (shown in FIGS. 2 and 4) fixed to one axial end of the base body 3 and the former F is moved in a predetermined direction. By rotating the rubber strip 4 in the X direction and moving the rubber strip 4 in the axial direction Y toward the other end side, the rubber strip 4 is spirally wound around the outer peripheral surface 3a of the base portion 3. The laminated portion 5 for forming the finished cross section of the tread rubber G1 by appropriately adjusting the moving speed or pitch in the axial direction.
Can be formed. The tread rubber G1 of this example has a finished cross-sectional shape in which the thickness gradually decreases toward the central portion.

The rubber strip 4 is wound continuously from one side in the axial direction to the other side as illustrated, and two pieces are wound from the central portion of the base portion 3 in the axial direction to the respective outer sides in the axial direction. Of the strips, and further, from the outer side in the axial direction of the base portion 3 toward the central portion 2
You can also wrap a strip of books. Further, three or more rubber strips 4 may be wound with a plurality of positions at different positions in the circumferential direction as winding start ends. The former two windings are preferable when the finished cross-sectional shape of the rubber member G is symmetrical. The rubber strip 4 may be wound continuously or may be discontinuous, and the cross-sectional shape of the rubber strip may be changed during the winding.

The rubber strip 4 may also be supplied while being unwound from a piece of fabric that has been previously formed by extrusion or the like, or may be supplied as it is. Also rubber strip 4
Does not need to cover the entire outer peripheral surface 3a of the base portion 3, and, for example, as shown in FIG. 3, the side edge 3e of the base portion 3 may not be wrapped and this portion may be exposed.

The tread rubber G1 of this embodiment can also be used as a rehabilitation tread rubber G1A arranged in the tread portion of the rehabilitation stand tire 20, as shown in FIG. In this case, the rubber extruded product 2 forms an annular base portion 3 by being wound around the outer surface of the rehabilitation surface 21 of the rehabilitation base tire 20 that has been buffed or the like, and the rubber strip is sequentially placed on the base portion 3. Tread rubber G by winding 4
1A is configured. The tread rubber G1A is hardened and integrated by vulcanization and given an appropriate pattern.

FIG. 5 shows a sectional view of a sidewall rubber G2 as another embodiment of the rubber member G for a tire. In this example, a base portion 3 in which a rubber extruded product 2 having a substantially trapezoidal cross section is connected in an annular shape, and a rubber strip 4 is spirally wound around the outer peripheral surface 3a of the base portion 3 in the circumferential direction. And a laminated portion 5 forming a finished cross section of G2.

FIG. 6 shows a sectional view of an inner liner rubber G3 as another embodiment of the rubber member G for a tire. In this example, a rubber extruded product 2 having a sheet-like cross section
And a base portion 3 in which the base portions 3 are connected in an annular shape, and an outer peripheral surface 3 of the base portion 3.
a, in this example, the rubber strip 4 is wound from both edges 3b, 3b in a circumferential direction and in a spiral shape.
3 and a laminated portion 5 which enlarges the finished cross section in the axial direction. Such an aspect is also included in the present invention.

FIG. 7 shows a sectional view of a bead apex rubber G4 as still another embodiment of the rubber member G for a tire. In this example, a base portion 3 in which rubber extruded products 2 each having a substantially triangular cross section are connected in an annular shape, and a rubber strip 4 is spirally wound around an outer peripheral surface 3a of one side 3A of the base portion 3 in a finished cross section. And the laminated portion 5 forming the. A bead core 15 is provided on the vertical side 3B of the base portion 3.

FIG. 8 shows a sectional view of a belt cushion rubber G6 as still another embodiment of the tire rubber member G. In this example, a base portion 3 in which rubber extruded products 2 each having a substantially trapezoidal cross section are connected in an annular shape, and a rubber strip 4 is spirally wound around the outer peripheral surface 3a of one side of the base portion 3 to form a finished cross section. It is composed of the laminated portion 5 to be formed. With respect to each of the rubber members G2 to G6, the rubber extruded product 2 can be shared with rubber members having different sizes or cross-sectional shapes, and the productivity can be greatly increased.
In the present embodiment, the side wall rubber G2, the bead apex rubber G4, the belt cushion rubber G6, etc. are formed by winding the rubber extruded product 2 around the outer peripheral surface of the carcass ply 13A wound around a cylindrical forming drum or the like. The part 3 is formed, and the rubber strip 4 is spirally wound on the part 3. Further, the inner liner rubber G3 can be formed on the molding drum. Although not shown, a clinch rubber G5, a chafer rubber or the like may be formed in the same manner. Then, a raw tire cover 1 is manufactured using these rubber members G1 to G6 for a tire, and by vulcanizing the raw cover 1, a pneumatic radial tire with good productivity can be obtained.

[0028]

As described above, the present invention can be applied to claim 1, 3 or 4.
In the invention described above, the rubber member for a tire is a base portion of a rubber member for a tire, which is formed by connecting rubber extruded products that are integrally extruded in an annular shape, and a rubber strip is circumferentially and spirally formed on the outer peripheral surface of the base portion. The rubber member for a tire is wound in a circular shape and is formed of a laminated portion that forms a finished cross section, so that the number of winding steps of the rubber strip can be reduced, so that the rubber member can be formed in a short time and the productivity is improved. Therefore, it is possible to produce a complicated tread rubber in a short time by using, for example, a rubber strip having a small cross-sectional area.

Further, the rubber extruded product can be shared between tread rubbers of different sizes, which increases the versatility of the rubber extruded product and requires a die having a different cross-sectional shape for each size. Compared with other rubber members, the number of types of die of the rubber extruder required for manufacturing can be greatly reduced, and the troublesome work of exchanging or adjusting the die can be eliminated. Can be further planned.

According to the second aspect of the invention, the base portion of the rubber member for a tire has an area of 30 to 50 of the area of the finished cross section.
%, It is possible to more reliably achieve the improvement in productivity.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a pneumatic radial tire showing an embodiment of the present invention.

FIG. 2 is a sectional view of an unvulcanized tread rubber used for the tire.

FIG. 3 is a sectional view of another embodiment of the tread rubber.

FIG. 4 is a perspective view showing an example of a manufacturing process of tread rubber.

FIG. 5 is a cross-sectional view showing an embodiment of a sidewall rubber.

FIG. 6 is a cross-sectional view showing an embodiment of an inner liner rubber.

FIG. 7 is a cross-sectional view showing an embodiment of a bead apex rubber.

FIG. 8 is a cross-sectional view showing an embodiment of a belt cushion rubber.

FIG. 9 is a cross-sectional view showing an example of a tread rubber for rehabilitation.

FIG. 10 is a cross-sectional view of a conventional tread rubber.

FIG. 11 is a sectional view of a conventional tread rubber.

[Explanation of symbols]

2 rubber extruded products 3 Base part of rubber member for tire 4 rubber strip 5 Laminated part of rubber member for tire G1 tread rubber G2 sidewall rubber G3 Inner liner rubber G4 bead apex rubber G5 clinch rubber G6 belt cushion rubber

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Claims (5)

(57) [Claims] 1. A base portion of a rubber member for a tire, which is formed by connecting integrally extruded rubber extruded products in an annular shape, and a rubber strip is wound around the outer peripheral surface of the base portion in a circumferential and spiral shape. A rubber member for a tire, comprising a laminated portion forming a finished cross section of the rubber member. 2. The base portion has a surface area of 3 of the finished cross section.
The rubber member for a tire according to claim 1, which has an area of 0 to 50%. 3. The tire rubber member according to claim 1, which is a tread rubber, a sidewall rubber, an inner liner rubber, a bead apex rubber, a clinch rubber, a chafer rubber or a belt cushion rubber. 4. The rubber member for a tire according to claim 3, wherein the tread rubber includes a tread rubber for rehabilitation arranged in a tread portion of a tire for rehabilitation. 5. A tire formed by using the rubber member for a tire according to claim 1.