JP4361638B2 - Steel cord manufacturing method and stranded wire machine used in this method - Google Patents

Description

【００３０】
【発明の効果】
この発明によれば、無撚り素線の並列配置に成るコアを有する扁平コードが、コア素線の配置に乱れを生ずることなしに製造されるから、所期した扁平コードを確実に得ることができる。
【図面の簡単な説明】
【図１】 チューブラー撚線機を示す模式図である。
【図２】 従来の撚線機を示す模式図である。
【図３】 撚り合わせ時のコア素線の理想配置を示す図である。
【図４】 撚り合わせ時のコア素線の実際の配置を示す図である。
【図５】 この発明に従う撚線機を示す模式図である。
【図６】 撚り合わせダイを示す断面図である。
【図７】 この発明に従う撚線機を示す模式図である。
【図８】 ローラー対を示す断面図である。
【図９】 この発明に従う撚線機を示す模式図である。
【図１０】 この発明に従う撚線機を示す模式図である。
【図１１】 コア素線の配列角を説明する図である。
【符号の説明】
１ａ〜１ｃ 素線
２ａ〜２ｃ ボビン
３ 回転バレル
４ａ〜４ｆ 素線
５ａ〜５ｆ ボビン
６ 撚り合わせダイ
７ プレフォーマー
８ ローラー対
９ 矯正ローラー群[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a steel cord, and more particularly, to a method for manufacturing a steel cord using a tubular twisted wire machine.
[0002]
[Prior art]
Steel cords that reinforce rubber articles such as pneumatic tires and conveyor belts are generally manufactured by twisting a plurality of strands. For twisting the strands, as shown in FIG. Tubular type twisting machines are often used.
[0003]
For example, a 3 + 6 layer twisted cord applied to carcass and belt reinforcement of pneumatic tires is obtained by winding and twisting six strands that become a sheath around a 1 × 3 core. Can be manufactured. That is, as shown in FIG. 1, the bobbin 2 around which the core 1 is wound is disposed outside the rotating barrel 3, while the bobbins 5 a to 5 f around which the sheath wires 4 a to 4 f are wound are placed inside the rotating barrel 3. Deploy. Next, the core 1 is guided along the barrel wall surface to the tip of the rotating barrel 3 by a guide or the like so as to bypass the bobbins 5a to 5f, and further guided from the barrel tip to the outer twisting die 6 on the barrel rotating shaft. . On the other hand, the sheath wires 4a to 4f are also guided along the barrel wall surface to the tip of the rotating barrel 3, and further guided on the barrel rotating shaft from the tip of the barrel to the preformer 7 outside thereof. A spiral-shaped die-molding process is performed in the same shape as the twisted state, and the sheathed wires thus shaped are twisted and guided to the die 6. When the rotary barrel 3 is rotated, the sheath strands 4 a to 4 f are wound around the core 1 in the twisting die 6, and the cord C is obtained.
[0004]
Incidentally, in recent years, it has been proposed to flatten the cord in order to improve various performances of the steel cord for tires. For example, in Japanese Patent Laid-Open No. 9-1558065, in a 3 + 6 structure cord, untwisted strands are arranged in parallel, the core is flattened, and the strand is wound around the core so that the cross section is elliptical. This code is disclosed. This flat cord has anisotropy in bending rigidity and high tensile strength, and can reduce the thickness when it is made into a rubberized cloth by flattening.
[0005]
When manufacturing such a cord using the above-described tubular type stranding machine, as shown in FIG. 2, one strand 1a to each of bobbins 2a to 2c arranged outside the rotating barrel 3 is used. 1c is unwound, and three strands are fed in parallel into the rotating barrel 3, and then twisted along the wall surface of the rotating barrel 3 to the tip of the barrel and further from the barrel tip to the outside on the barrel rotating shaft. The sheath wire led to the die 6 and guided in the same manner as described above is wound around the cores 1 arranged in parallel.
[0006]
[Problems to be solved by the invention]
Here, if the core strands are introduced into the rotating barrel in a parallel state, the parallel state should be maintained as shown in FIG. 3 even after passing through the barrel along the barrel wall surface.
[0007]
However, in practice, it is inevitable that the arrangement of the core strands changes due to the resistance when the core strands pass through the barrel wall surface. For example, as shown in FIG. As a result of irregular disturbance, the cross-sectional shape of the core led to the twisting die changes in various shapes in the longitudinal direction. That is, the direction in which the cores are arranged changes to cause the cores to be twisted, or in extreme cases, the core strands may cross each other and flattening of the cores may be hindered.
[0008]
As a result, the desired flat shape cannot be given to the core, and as a result, the desired flattening cannot be achieved for the obtained cord. Even if correction is performed with a correction roller on the exit side of the twisting die, it is extremely difficult to correct the core. It is possible to correct the appearance by correcting the strength, for example, to correct the twist. However, since the elastic twist still exists, the disadvantage that the twist appears again when the cord is cut cannot be avoided.
[0009]
Thus, the flat cords produced by the conventional manufacturing method are difficult to obtain the various properties expected of the flat cords because the flattening is not properly realized.
[0010]
In view of this, the present invention relates to a twisting machine used in this manufacturing for a method that does not disturb the arrangement of the core strands in the manufacturing process of the flat cord having the cores that are arranged in parallel with the untwisted strands. The purpose is to propose.
[0011]
[Means for Solving the Problems]
That is, the gist configuration of the present invention is as follows.
(1) A rotating barrel in which a plurality of bobbins for unwinding the strands are arranged inside, and a tubular type twisted wire machine having an assembly portion of the strands on a barrel rotating shaft outside the rotating barrel. When manufacturing a steel cord comprising a core in which two strands are bundled in parallel without being twisted, and a sheath made of a plurality of strands wound around the core, the three strands that serve as the core are manufactured. A core unwinding bobbin for unwinding a wire and a sheath unwinding bobbin for unwinding an element wire serving as a sheath are disposed inside the rotating barrel, and the core unwinding bobbin is disposed more than the sheath unwinding bobbin. The three strands serving as cores are arranged on the side close to the gathering portion, and the gathering is performed while maintaining the parallel arrangement of the three strands through a position separated from the barrel inside the rotating barrel. part in Do not give tension Method for producing a steel cord, characterized by directing al, a.
[0012]
(2) A method of manufacturing a steel cord according to the above (1), wherein a strand serving as a sheath is wound around the strand of the core between the rollers of the roller pair disposed in the gathering portion.
[0013]
(3) In the above-mentioned (1), in the twisting die having a flat cross-section hole arranged in the gathering portion, the production of a steel cord characterized by winding a sheath wire around the core strand Method.
[0014]
(4) The method of manufacturing a steel cord according to any one of (1) to (3), wherein the steel cord after twisting is straightened with a straightening roller.
[0015]
(5) A core unwinding bobbin for unwinding a core wire and a sheath unwinding bobbin for unwinding a strand serving as a sheath have a rotating barrel disposed inside, and a barrel outside the rotating barrel. A tubular type twisted wire machine having an assembly portion of the strands on a rotating shaft, wherein all of the core unwinding bobbins are arranged closer to the assembly portion than the sheath unwinding bobbins, and the core unwinding A tubular twist that has a path from the bobbin through the position separated from the barrel inside the rotating barrel to the gathering portion while maintaining the parallel arrangement of the strands Wire machine.
[0017]
(6) above (5) to Oite, tubular type stranding machine, characterized in that a roller pair in the set section.
[0018]
(7) above (5) to Oite, tubular type stranding machine, wherein the cross section is disposed and the combined die twisted with a hole in the flat shape to the collecting portion.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Next, the method of the present invention will be described in detail with reference to FIG.
In this invention, first, bobbins 2a to 2c around which the core wires 1a to 1c are wound are arranged at the front end of the rotating barrel 3, that is, at the twisting side, and the element that becomes the sheath at the rear end side of the barrel. It is important to arrange the bobbins 5a to 5f around which the wires 4a to 4f are wound. That is, the bobbins 2a to 2c of the core strands 1a to 1c, which are conventionally arranged outside the rotating barrel 3, are arranged inside the rotating barrel 3 and further to the barrel tip side than the bobbins 5a to 5f of the sheath strand. By doing so, the core strands 1a to 1c do not bypass the bobbins 5a to 5f of the sheath strands, and the core strands 1a to 1c reach the outside of the rotating barrel 3 at a position separated from the inner wall of the barrel, preferably on the rotating shaft of the rotating barrel. Secure the path of the wire.
[0020]
When the core wire is guided from the inside of the rotating barrel 3 to the outer twisting die 6 without being along the wall surface of the rotating barrel 3, the core wire is not affected by the operation of the rotating barrel. In other words, the strands are guided to the outside of the rotating barrel 3 while maintaining the parallel arrangement of the strands. Therefore, the core strand in which an appropriate parallel arrangement without any twists or crossing portions continues in the longitudinal direction is guided to the gathering portion outside the rotating barrel 3. Then, in the twisting die 6 outside the rotating barrel 3, the strands 4 a to 4 f serving as a sheath guided through the preformer 7 around the cores maintained in parallel are rotated by the rotating barrel 3. As a result, the desired flat cord is obtained.
[0021]
When the core wire is unwound from the bobbin and led to the twisting die, if the tension applied to the strand is low, the core wire is easy to move in the process of winding the sheath wire around the core, sequences of the strands of the core is disturbed, since the risk is, Ru tensioned to the extent that movement of the strands of the core is limited to the core wire.
[0022]
Here, as shown in FIG. 6 (a) or (b), the twisting die 6 arranged in the gathering portion outside the rotating barrel 3 has a hole 60 whose cross-sectional shape is an ellipse or a long square. By twisting together under the constraint of 60, it plays the role of maintaining the parallel arrangement of the cores when the sheath wire is wound.
[0023]
In addition, as shown in FIG. 7, instead of the twisting die 6, the roller pair 8 may be disposed in the gathering portion, and twisting may be performed between the rollers of the roller pair 8. Also in this roller pair 8, as in the case of the twisting die 6, it is advantageous to have a roller gap 80 whose cross-sectional shape is an ellipse or a long square as shown in FIG. 8.
[0024]
Furthermore, it is preferable to provide a correction roller group 9 on the exit side of the twisting die 6 or the roller pair 8 to correct the arrangement disorder of each strand when the sheath strand is wound around the core. It is to be noted that the sheath filament is typically shaped like a cylindrical spiral, and in this case, the shaping needs to be flattened by the correction roller group 9. In the cord manufactured according to the above, since the sheath wire is wound around the core guided without disturbing the parallel arrangement, a cord with no disorder in the arrangement of the core wire is obtained. Even if the arrangement of the strands is disturbed in the twisting at, the disorder of the strands can be corrected by correcting the straightening roller group 9.
[0025]
5 and 7 described above, a bobbin is prepared for each core strand and arranged in the rotating barrel 3. However, as shown in FIG. 9 or 10, a plurality of strands are wound. A single bobbin 2 taken may be disposed in the rotating barrel 3, and a plurality of, for example, three strands may be simultaneously unwound from the bobbin 2 and guided from the inside of the rotating barrel 3 to the outside. . In this case, since the number of core bobbins installed can be reduced, the installation space for the bobbins in the rotating barrel can be saved. By the way, in order to wind up a plurality of strands on one bobbin, it is possible to manufacture a strand using a so-called multi-drawing machine capable of drawing a plurality of strands by one unit. This is advantageous in terms of productivity.
[0026]
【Example】
A steel cord was manufactured by winding eight sheath strands having the same diameter around a core wire having a diameter of 0.26 mm and a twist pitch of 18 mm using the twisting machine shown in FIG. Three core wires were wound on one bobbin, and the unwinding tension was 10 kgf. The design values of this cord are a major axis: 1.30 mm and a minor axis: 0.78 mm.
[0027]
For comparison, a steel cord similar to the above was manufactured using the twisting machine shown in FIG. That is, one bobbin around which three core wires were wound was placed outside the rotating barrel, and the core wire was led from here to the tip of the rotating barrel along the wall surface of the rotating barrel and twisted.
[0028]
Over the length of 7500 m of the cord thus produced, 250 cross-sectional shapes at 30 m intervals were observed. That is, the arrangement of the core strands in the cord cross section was evaluated as the array angle θ formed by the line segment connecting the central axes of the core strands as shown in the typical examples in FIGS. . Then, 180 ° ≧ θ> 150 ° is A rank, 150 ° ≧ θ> 90 ° is B rank, and 90 ° ≧ θ> 60 ° is C rank. did.
[0029]
[Table 1]

[0030]
【The invention's effect】
According to the present invention, the flat cord having the core that is arranged in parallel with the untwisted strands is manufactured without causing any disturbance in the arrangement of the core strands, so that the intended flat cord can be reliably obtained. it can.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a tubular stranded wire machine.
FIG. 2 is a schematic diagram showing a conventional stranded wire machine.
FIG. 3 is a diagram showing an ideal arrangement of core wires at the time of twisting.
FIG. 4 is a diagram showing an actual arrangement of core wires at the time of twisting.
FIG. 5 is a schematic view showing a stranded wire machine according to the present invention.
FIG. 6 is a cross-sectional view showing a twisting die.
FIG. 7 is a schematic diagram showing a stranded wire machine according to the present invention.
FIG. 8 is a cross-sectional view showing a roller pair.
FIG. 9 is a schematic view showing a stranded wire machine according to the present invention.
FIG. 10 is a schematic view showing a stranded wire machine according to the present invention.
FIG. 11 is a diagram for explaining an array angle of core wires.
[Explanation of symbols]
1a to 1c Wire 2a to 2c Bobbin 3 Rotating barrel 4a to 4f Wire 5a to 5f Bobbin 6 Twist die 7 Preformer 8 Roller pair 9 Straightening roller group

Claims (7)

Using a tubular type twisted wire machine having a rotating barrel in which a plurality of bobbins for unwinding the strands are arranged inside, and an assembly of the strands on a barrel rotating shaft outside the rotating barrel, a plurality of strands are used. When manufacturing a steel cord consisting of a core bundled in parallel without twisting the wire and a sheath of a plurality of strands wound around this core,
A core unwinding bobbin for unwinding each of the three strands serving as the core and a sheath unwinding bobbin for unwinding a plurality of strands serving as the sheath are disposed inside the rotating barrel; The core unwinding bobbin is disposed closer to the gathering portion than the sheath unwinding bobbin, and the three strands serving as the core pass through the three barrels separated from the barrel inside the rotating barrel . A method of manufacturing a steel cord, wherein the steel cord is guided while tension is applied to the gathering portion while maintaining the parallel arrangement of the strands .   2. The method of manufacturing a steel cord according to claim 1, wherein a strand serving as a sheath is wound around the strand of the core between the rollers of the pair of rollers arranged in the collecting portion.   2. The method of manufacturing a steel cord according to claim 1, wherein in a twisting die having a flat cross section disposed in the gathering portion, a wire serving as a sheath is wound around the core wire.   4. The method of manufacturing a steel cord according to claim 1, wherein the steel cord after twisting is straightened by a straightening roller. A core unwinding bobbin for unwinding a core wire and a sheath unwinding bobbin for unwinding a sheath wire are arranged on a rotating barrel disposed inside, and on a barrel rotating shaft outside the rotating barrel. The core unwinding bobbin is arranged on the side closer to the collecting portion than the sheath unwinding bobbin, and the core unwinding bobbin the wire passes through a position spaced apart from the said barrel within said rotating barrel, tubular type stranding machine, characterized in that it comprises a journey leading to the collecting unit remains parallel arrangement is maintained in the plain line. 6. The tubular twisted wire machine according to claim 5, wherein a pair of rollers is arranged in the gathering portion . 6. The tubular twisted wire machine according to claim 5, wherein a twisting die having a hole having a flat cross section is disposed in the gathering portion .

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