JP4021331B2 - Steel cord for rubber reinforcement, rubber product using the steel cord and manufacturing method thereof, and pneumatic tire using the steel cord and manufacturing method thereof - Google Patents

Description

【００２８】
表１から判るように、実施例のタイヤは、耐カット性が従来例のタイヤに比べて大幅に向上し、比較例のタイヤと対比しても改善効果が見られた。また、実施例では、偏平コイルのスチールコードが略直線形状の癖付け部を備え、その形状安定性が優れているため、比較例に比べてスチールブレーカープライの成形生産性が良好であった。
【００２９】
【発明の効果】
以上説明したように本発明によれば、複数のループ部が順次部分的に重なる偏平コイル状のスチールコードにおいて、隣り合うループ部の相互間にコード幅方向端部でコード長手方向に延長する略直線形状の癖付け部を設けたことにより、ゴム補強用スチールコードの寸法安定性を向上し、延いては、空気入りタイヤに代表されるゴム製品を製造するに際して、加工性や作業性を改善すると共に、安定した品質を確保することが可能になる。
【図面の簡単な説明】
【図１】本発明の実施形態からなる空気入りタイヤを示す子午線半断面図である。
【図２】偏平コイル状のスチールコードを示し、（ａ）は平面図、（ｂ）は側面図、（ｃ）はＸ−Ｘ矢視断面図である。
【符号の説明】
１１ ループ部
１２ 癖付け部
Ｓ スチールコード[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rubber reinforcing steel cord processed into a flat coil shape, and more specifically, a rubber reinforcing steel cord excellent in shape stability, a rubber product using the steel cord, a manufacturing method thereof, and the steel The present invention relates to a pneumatic tire using a cord and a manufacturing method thereof.
[0002]
[Prior art]
Conventionally, it has been proposed to use a steel cord processed into a flat coil shape as a reinforcing material for a pneumatic tire (see, for example, Patent Document 1 and Patent Document 2). Such a flat coil steel cord is formed by crushing a cylindrical coil steel cord so that each loop part falls down in the coil axis direction or sequentially pulling the loop part in a direction perpendicular to the coil axis direction. And processed into a predetermined shape. As a result, in the flat coiled steel cord, the plurality of loop portions are arranged so as to partially overlap each other.
[0003]
However, the flat-coiled steel cord processed as described above is difficult to handle because it is difficult to stabilize the shape, and it is difficult to handle the rubber product using the steel cord. It also destabilizes the quality. Moreover, in order to reduce the variation in quality, it is necessary to complicate the steel cord supply facility, which increases the manufacturing cost of rubber products.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-217716 [Patent Document 2]
Japanese Patent Laid-Open No. 10-258609
[Problems to be solved by the invention]
An object of the present invention is to provide a steel cord for reinforcing rubber excellent in shape stability, a rubber product whose workability, workability and quality are improved by using the steel cord, a manufacturing method thereof, and the use of the steel cord. An object of the present invention is to provide a pneumatic tire improved in workability, workability, and quality, and a manufacturing method thereof.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a steel cord for rubber reinforcement according to the present invention is a flat coil-shaped steel cord in which a plurality of loop portions partially overlap each other in an end portion in the cord width direction between adjacent loop portions. A substantially linear brazing portion extending in the longitudinal direction of the cord is provided.
[0007]
Further, the rubber product of the present invention has a flat coil shape in which a plurality of loop portions are partially overlapped in sequence, and has a substantially linear shape extending in the cord longitudinal direction at the cord width direction end between adjacent loop portions. The steel cord provided with the attaching portion is embedded in rubber as a reinforcing material.
[0008]
In addition, the rubber product manufacturing method of the present invention has a flat coil shape in which a plurality of loop portions sequentially partially overlap each other, and extends substantially in the cord longitudinal direction at the cord width direction end between adjacent loop portions. A steel cord provided with a brazed portion having a shape is embedded in an unvulcanized rubber as a reinforcing material to form an unvulcanized rubber product, and then the unvulcanized rubber product is vulcanized It is.
[0009]
Further, the pneumatic tire of the present invention has a flat coil shape in which a plurality of loop portions sequentially partially overlap each other, and has a substantially linear shape extending in the cord longitudinal direction at the end portion in the cord width direction between adjacent loop portions. A steel cord provided with a brazing portion is embedded in rubber as a reinforcing material.
[0010]
Further, the pneumatic tire manufacturing method of the present invention has a flat coil shape in which a plurality of loop portions are sequentially partially overlapped, and extends in the cord longitudinal direction at the end portions in the cord width direction between adjacent loop portions. A steel cord provided with a linear brazing portion is embedded in unvulcanized rubber as a reinforcing material to form an unvulcanized tire, and then the unvulcanized tire is vulcanized. is there.
[0011]
Thus, by providing the substantially linear brazing part between the adjacent loop parts, the shape of the flat coiled steel cord can be stabilized. Therefore, when manufacturing a rubber product typified by a pneumatic tire using a flat coil-shaped steel cord, it is possible to improve workability and workability and ensure stable quality.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.
[0013]
FIG. 1 shows a pneumatic tire according to an embodiment of the present invention, wherein 1 is a tread portion, 2 is a sidewall portion, and 3 is a bead portion. A plurality of carcass layers 4 are mounted between the pair of left and right bead portions 3 and 3. These carcass layers 4 are laminated so that the reinforcing cords cross each other. Three sets of bead cores 5 are embedded in each bead portion 3, and both end portions of the carcass layer 4 are folded back from the inner side of the tire so as to sandwich the bead filler 6 around the bead cores 5. An inner liner layer 7 is provided on the inner side of the carcass layer 4 between the left and right bead portions 3 and 3. Further, a breaker layer 8 made of an organic fiber cord is embedded on the outer peripheral side of the carcass layer 4 extending between both sidewall portions 2 and 2. Furthermore, a breaker layer 9 made of steel cord is embedded on the outer peripheral side of the breaker layer 8 made of organic fiber cord. CL is a tire center line passing through the tire equatorial plane.
[0014]
In the pneumatic tire, a flat coiled steel cord S is used for the breaker layer 9, and the steel cord S is continuously wound in the tire circumferential direction. That is, the cord angle of the steel cord S with respect to the tire circumferential direction is approximately 0 °. The steel cord S is composed of at least one strand. Here, the steel cord S may be one in which a single strand is formed in a flat coil shape, or is formed in a flat coil shape in a state where a plurality of strands are aligned or twisted. There may be. In particular, when the steel cord S is composed of a plurality of strands, it is preferable to twist the strands. As the twisted structure, a known structure can be applied, and a 1 × n structure is preferable from the viewpoint of rubber permeability, but is not limited thereto.
[0015]
The wire diameter of the steel cord S is preferably 0.10 to 5.00 mm, and more preferably 0.12 to 2.50 mm. When the strand diameter is below the lower limit, the strength is insufficient, and when it exceeds the upper limit, the elongation is insufficient, the flexibility is lowered, and separation is likely to occur.
[0016]
FIGS. 2A to 2C illustrate a flat coil steel cord. As shown in FIGS. 2A to 2C, the steel cord S has a plurality of loop portions 11, and these loop portions 11 are configured to partially overlap each other in sequence. Moreover, a substantially linear brazing portion 12 is formed between the adjacent loop portions 11 and 11.
[0017]
The method for forming the flat coiled steel cord S is not particularly limited, but the following method can be exemplified. That is, after the steel cord is formed into a cylindrical coil shape, the portion between the loop portion of the terminal and the loop portion connected to the terminal is brazed in a substantially linear shape with the loop portion of the terminal being shifted in the coil axis direction. And by repeating this brazing process, the flat coil-shaped steel cord S provided with the substantially linear brazing part 12 between the adjacent loop parts 11 and 11 can be shape | molded.
[0018]
The length L of the brazing part 12 is 0.02 W to 0.95 W, more preferably 0.05 W to 0.50 W with respect to the coil width W of the steel cord S. When the length L of the brazing portion 12 is less than the lower limit value, the shape stability of the cord is lowered, the flexibility of the cord is lowered, and separation is likely to occur. Moreover, when the length L of the brazing part 12 exceeds an upper limit, intensity | strength becomes inadequate. The coil width W may be selected from a range of 3.0 to 150.0 mm.
[0019]
It is preferable that the number N of laps of other loop portions that overlap an arbitrary loop portion among the plurality of loop portions 11 is 1 to 15. When the number of laps N is below the lower limit, the strength is insufficient, and when it exceeds the upper limit, the flexibility is lowered and separation is likely to occur. Note that the number of wraps N is the number of other loop portions that overlap an arbitrary loop portion from one direction. That is, the number N of laps of the steel cord S shown in FIGS.
[0020]
In the flat coiled steel cord S, the ratio of the coil height H to the coil width W (H / W × 100%) is preferably 2 to 50%. When this flatness ratio is less than the lower limit value, the strength is insufficient, and when it exceeds the upper limit value, flexibility is lowered and separation is likely to occur. The coil shape is not particularly limited, and may be a polygon such as a perfect circle or an ellipse. The substantially linear brazing portion may be on one side or both sides in the coil width direction.
[0021]
The flat coiled steel cord S described above is excellent in shape stability because it has a substantially linear brazing portion 12 between the adjacent loop portions 11 and 11. And when such a flat coiled steel cord S is used as a reinforcing material for the breaker layer 9 of the pneumatic tire, the quality of the breaker layer 9 can be stabilized, and as a result, the cut resistance can be improved. . Further, the flat coiled steel cord S is flexible and has a large elongation, and is therefore optimal as a rubber reinforcing material.
[0022]
When manufacturing the above-mentioned pneumatic tire (rubber product), after embedding the flat coiled steel cord S as a reinforcing material in the unvulcanized rubber and molding the unvulcanized tire (unvulcanized rubber product), The unvulcanized tire is vulcanized. In such a manufacturing process, since the flat coiled steel cord S has a stable dimension, it is easy to process and handle. Further, since the flat coiled steel cord S has a stable behavior during processing, it is not necessary to complicate the steel cord supply equipment. Therefore, in the above-described embodiment, which can reduce the manufacturing cost of the pneumatic tire, the case where the rubber product is a pneumatic tire has been described. However, in the present invention, a conveyor belt, a marine hose, a fender, and the like are used as the rubber product. Can be mentioned. Moreover, the reinforcement site | part of a pneumatic tire is not specifically limited.
[0023]
【Example】
Pneumatic tire for ore carrying vehicles with tire size 1200-24 16PR, TRA CODE L4 smooth red, and bias structure composed of 8 nylon carcass plies, 2 nylon breaker plies and steel breaker ply The conventional example, the comparative example, and the example in which only the structure of the steel breaker ply was varied as shown in Table 1 were produced.
[0024]
These test tires were evaluated for cut resistance and steel breaker ply molding productivity by the following test methods, and the results are shown in Table 1.
[0025]
[Cut resistance]
The test tire was assembled with a rim at an air pressure of 550 kPa, mounted on an ore transporting vehicle, and actually used for transporting work in the mine. . The evaluation results are shown as an index with the conventional example being 100, using the reciprocal of the measured value. It means that cut resistance is excellent, so that this index value is large.
[0026]
[Molding productivity of steel breaker ply]
The molding time of the steel breaker ply on the molding drum was measured. The evaluation results are shown as an index with the comparative example being 100, using the reciprocal of the measured value. The larger the index value, the better the molding productivity (workability and workability) of the steel breaker ply.
[0027]
[Table 1]

[0028]
As can be seen from Table 1, the tires of the examples have significantly improved cut resistance as compared with the conventional tires, and an improvement effect was seen even when compared with the tires of the comparative examples. Moreover, in the Example, since the steel cord of the flat coil was provided with the substantially linear brazing part, and the shape stability was excellent, the shaping | molding productivity of the steel breaker ply was favorable compared with the comparative example.
[0029]
【The invention's effect】
As described above, according to the present invention, in a flat coil-shaped steel cord in which a plurality of loop portions partially overlap each other , it is substantially extended in the cord longitudinal direction at the end portion in the cord width direction between adjacent loop portions. By providing a straight brazed part, the dimensional stability of the steel cord for rubber reinforcement is improved, and as a result, when manufacturing rubber products represented by pneumatic tires, workability and workability are improved. In addition, stable quality can be ensured.
[Brief description of the drawings]
FIG. 1 is a meridian half sectional view showing a pneumatic tire according to an embodiment of the present invention.
2A and 2B show a flat-coiled steel cord, in which FIG. 2A is a plan view, FIG. 2B is a side view, and FIG.
[Explanation of symbols]
11 Loop part 12 Brazing part S Steel cord

Claims (10)

A flat-coiled steel cord in which a plurality of loop portions partially overlap each other, and a substantially linear brazing portion extending in the cord longitudinal direction at the cord width direction end portion is provided between adjacent loop portions. Steel cord for rubber reinforcement. A steel cord having a flat coil shape in which a plurality of loop portions sequentially partially overlap each other and provided with a substantially linear brazing portion extending in the cord longitudinal direction at the cord width direction end between adjacent loop portions, Rubber products embedded in rubber as a reinforcing material. A steel cord having a flat coil shape in which a plurality of loop portions sequentially partially overlap each other and provided with a substantially linear brazing portion extending in the cord longitudinal direction at the cord width direction end between adjacent loop portions, A method for producing a rubber product, comprising embedding in an unvulcanized rubber as a reinforcing material and molding an unvulcanized rubber product, and then vulcanizing the unvulcanized rubber product. A steel cord having a flat coil shape in which a plurality of loop portions sequentially partially overlap each other and provided with a substantially linear brazing portion extending in the cord longitudinal direction at the cord width direction end between adjacent loop portions, A pneumatic tire embedded in rubber as a reinforcing material. A steel cord having a flat coil shape in which a plurality of loop portions sequentially partially overlap each other and provided with a substantially linear brazing portion extending in the cord longitudinal direction at the cord width direction end between adjacent loop portions, A method for producing a pneumatic tire in which an unvulcanized tire is molded by being embedded in an unvulcanized rubber as a reinforcing material, and then the unvulcanized tire is vulcanized. The steel cord for rubber reinforcement according to claim 1, wherein a length L of the brazing portion is 0.02 W to 0.95 W with respect to a coil width W of the steel cord. The rubber product according to claim 2, wherein a length L of the brazing portion is 0.02 W to 0.95 W with respect to a coil width W of the steel cord. The method for producing a rubber product according to claim 3, wherein a length L of the brazing portion is 0.02 W to 0.95 W with respect to a coil width W of the steel cord. The pneumatic tire according to claim 4, wherein a length L of the brazing portion is 0.02 W to 0.95 W with respect to a coil width W of the steel cord. The method for manufacturing a pneumatic tire according to claim 5, wherein a length L of the brazing portion is 0.02 W to 0.95 W with respect to a coil width W of the steel cord.

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