JP4312096B2 - Metal cord for reinforcing rubber articles and method for producing the cord - Google Patents

Description

  The present invention relates to a low-cost metal cord for reinforcing a rubber article that improves the penetration of rubber into the interior without reducing the compression rigidity, and a method for manufacturing the cord.

  In general, a requirement for a metal cord for reinforcing a tire of a passenger car is that it has excellent compression rigidity that affects rubber penetration and cornering characteristics of the car. However, both properties of metal cords for reinforcing rubber articles that are frequently used recently have a trade-off relationship. For example, the steel cord of Patent Document 1 below, in which a wire has a wave smaller than the twist pitch, has a rubber penetration rate. However, there is a problem that the compression rigidity is lower than that of a metal cord (compact cord) in which the wire is not corrugated. Even if the wave applied to the strand is fine or two-dimensional, a large three-dimensional wave corresponding to the twisting pitch is added during the twisting process, and the belly part of the fine wave bending part is outside. There is a portion that starts to appear once in one twist pitch, and this portion becomes weak against the compression load, so that the compression rigidity is lowered. In addition, when the height of the wave applied in advance to the strand is increased, the cord is compressed over the entire length of the cord regardless of whether the belly part of the bent portion of the fine wave is outside or inside. Stiffness decreases.

  On the other hand, the steel cords disclosed in Patent Documents 2 to 4 below all improve the corrosion resistance by increasing the permeability of rubber without corrugating the strands. The twisting process is performed once on any one of them, and then final twisting is performed, which inevitably increases equipment costs and manufacturing costs. Moreover, since the cord of Patent Document 2 is a so-called open-structure cord, the elongation in the low load region is large, and troubles such as cord overlap occur due to instability when the cords are aligned in the intermediate process. Sometimes.

Note that the steel cord of Patent Document 1 is a first strand bundle in which two strands with two-dimensional or three-dimensional fine waves are bundled substantially in parallel to increase the twisting rate. The second strand bundle is a wave of the first strand bundle so that the same stranding rate as the first strand bundle can be obtained for the second strand bundle and the other two strands (second strand bundle). The first strand bundle is entangled with each other at a spiral pitch larger than the attaching pitch,
In addition, the steel cord of Patent Document 2 has two sets of bundling bodies in which two or three strands or strands are arranged in contact with each other, keeping a gap of 8 to 30% of the strand diameter or strand diameter. While twisting together in parallel with each other,
Furthermore, the steel cord of Patent Document 3 is one in which two strands of wire twisted together and two parallel wires are twisted together to increase the permeability of rubber and ensure excellent elastic performance. ,
The steel cord of Patent Document 4 is composed of a group of two strands and a group of three strands. The group of two strands is parallel to the cord direction, and the group of three strands is Two strands of strands that are twisted alternately in half-pitch, roughly umbrella-like, roughly umbrella-like,
The steel cord of Patent Document 5 includes two first wire bundles having a twist pitch of 50 mm or more, three second wire bundles having a pitch smaller than the twist pitch of the first wire bundle, and the first wire bundle. Are wound spirally so that a gap of 10% or more is formed within one pitch of twist of the first wire bundle.
Japanese Patent Laid-Open No. 06-73672 Japanese Patent Publication No. 60-10151 Japanese Patent Publication No. 61-01554 Japanese Patent Publication No. 03-23673 Japanese Patent No. 3174803

  The present invention has been made in view of the above, a metal cord for reinforcing rubber articles that can improve the penetration of rubber into the interior without reducing the compression rigidity, and can reduce equipment costs and manufacturing costs. It is an object to provide a method for manufacturing the code.

  In order to solve the above problems, in the present invention, a first filament bundle in which another metal filament is wound spirally around one metal filament, and a first filament bundle wound around one metal filament. A metal cord for reinforcing a rubber article comprising four metal filaments formed by twisting a second filament bundle in which another metal filament is spirally wound in a direction opposite to the direction and twisting each other at a twist pitch P provide.

  The first and second filament bundles may be further twisted together at a twist pitch P by adding one metal filament to them, and a metal cord for reinforcing rubber articles composed of the five metal filaments thus obtained is also provided. To do.

In this metal cord for reinforcing rubber articles, the winding pitches p ₁ and p ₂ of one metal filament to one metal filament of the first and second filament bundles are set to the twist pitch P of the cord.
0.922 ≦ p ₁ /P≦0.991
1.010 ≦ p ₂ /P≦1.085
It is preferable to satisfy the following formula.

  It is also preferable that the cord twist angle α ° is in the range of 3.5 ° to 7.3 °. As shown in FIG. 5, the twist angle of the cord is expressed by the inclination angle of the metal filament with respect to the cord center line at the cord center portion in the side view.

  In addition, the metal cord for reinforcing rubber articles according to the present invention composed of 4 to 5 metal filaments passes through one metal filament through the center of the pass line and uses a flyer for this metal filament. A first filament bundle and a second filament bundle obtained by winding a metal filament in a spiral shape and winding the other one metal filament in opposite directions, or the first and second filament bundles and further different One metal filament is introduced into a stranded wire machine and twisted at a twisting pitch P to manufacture. The present invention also provides a manufacturing method thereof.

  The metal cord of the present invention has a filament bundle in which one metal filament is spirally wound around one metal filament, and two sets of the filament bundle or one metal filament is added to the two bundles. Since the objects are twisted together, the spirally wound metal filaments in each filament bundle serve as spacers, ensuring a gap between the metal filaments that allows the rubber to enter without creating fine waves on the metal filaments. It is possible to increase the permeability of the rubber without causing a decrease in compression rigidity.

  In addition, winding of another metal filament around one metal filament can be performed without twisting using a simple supply device and a flyer, and only one twister is required, and Manufacturing costs can be reduced.

  Furthermore, since the winding direction of the other one metal filament with respect to one metal filament in the first and second filament bundles is reversed, the balance of the twist of the filament generated by winding is improved, and after the final twisting Variation in the residual torsion of the cord becomes smaller and the quality of the cord becomes stable.

In the first filament bundle, the winding pitch p ₁ is made smaller than the twisting pitch P of the cord by making the winding direction of one other metal filament around one metal filament the same as the twisting direction of the cord. The winding frequency in the longitudinal direction of the cord can be increased. When the winding pitch p ₁ is close to the twisting pitch P, the gap between the filaments becomes small. Therefore, the winding pitch p ₁ is preferably 0.991 or less in terms of the ratio to the twisting pitch P. Further, when the winding and 0.922 or less in the ratio of the pitch P twist pitch p _1, can code compression rigidity is easily bent is prevented from being lowered, therefore, the winding pitch p ₁ is 0. A range of 922P to 0.991P is preferable.

In the second filament bundle, in order to balance the twist with the first filament bundle, the winding direction of the other metal filament around one metal filament is opposite to the twisting direction of the cord. Therefore, it is desirable that the amount of twist generated in the other metal filament by winding and the number of times of winding of the other metal filament do not change extremely from those of the first filament bundle. It is preferable that the pitch p ₂ is in the range of 1.010P to 1.085P corresponding to the substantially reciprocal number of the first filament bundle.

Further, the twist angle α ° of the metal cord is determined by the twist pitch and the cord diameter, the lower limit of the twist angle is 3.5 ° in a range where the cord end is not scattered, the upper limit is the winding pitch p ₁ , similar to p _2, it is suppressed to up to 7.3 ° the compression rigidity is easily bent is larger when the code is reduced.

  According to the manufacturing method of the present invention, the metal cord for reinforcing rubber articles can be manufactured with a simple facility while suppressing the manufacturing cost.

  Embodiments of the present invention will be described below with reference to FIGS. 1 to 4 of the accompanying drawings. FIG. 1 schematically shows a cross section of a metal cord for reinforcing a rubber article according to the present invention, which is composed of four metal filaments, cut in the longitudinal direction at intervals of 1/4 P (P = twist pitch of the cord). It is. This cord may be a Z-twisted cord, but the following description is based on the S-twisted cord shown in the figure.

As shown in FIG. 2, the metal cord 6 is formed by winding a single metal filament 1 around another metal filament 2 in a spiral manner to form a filament bundle 6 a _1. Another filament 4 is spirally wound to form a filament bundle 6a ₂ , and the two sets of filament bundles 6a ₁ and 6a ₂ are twisted at a pitch P. The winding direction of the metal filament 2 around the metal filament 1 is the same as the twisting direction of the cord, and the winding direction of the metal filament 4 around the metal filament 3 is opposite to the twisting direction of the cord.

  In addition, although a steel cord can be obtained by using a plated steel filament as the metal filament, the cord of the present invention is not limited to the steel cord.

In addition to the three-dimensional rotation in the S twist direction by twisting the filament bundles 6a ₁ and 6a ₂ , rotation by winding the metal filaments 2 and 4 around the metal filaments 1 and 3 is applied. An appropriate gap is formed between the metal filaments by serving as a spacer, thereby improving the penetration of the rubber into the interior.

  In addition, since each metal filament is not irregularly shaped such as fine waves, a compression rigidity equivalent to that of a closed cord having a 1 × 4 twisted structure that does not consider rubber penetration is ensured. If four metal filaments are simply twisted together, it becomes a closed cord with an ordinary 1 × 4 twist structure, and there is no gap between the metal filaments, creating a space isolated from the outside, resulting in poor rubber penetration. However, in the present invention, since two sets of filament bundles in which one metal filament is spirally wound around one metal filament are twisted together, the cord does not have a closed structure.

In the filament bundle 6a ₁ , since the winding direction of the metal filament 2 around the metal filament 1 is the same as the twisting direction of the cord, it is easy to ensure the gap between the filaments.

The winding pitches p ₁ and p ₂ of the metal filaments 2 and 4 with respect to the metal filaments ₁ and ₃ are 0.922 ≦ p ₁ /P≦0.991 and 1.010 ≦ p ₂ / P ≦ 1. It is preferable to set so as to satisfy the condition 085.

  Furthermore, the twist angle α ° of the cord is preferably 3.5 ° to 7.3 °. The reason was already mentioned.

Next, the manufacturing method of the metal cord for reinforcing rubber articles of FIG. 1 will be described based on the conceptual diagram of FIG. In FIG. 3, 7 _-1 and 7 _-2 are drive supply devices for setting the reels 8 _-1 and 8 _-2 , 9 _-1 and 9 _-2 are guides, 10 _-1 and 10 _-2 are reels 11 _-1. , 11 _-2 is a dead supply device, 12 _-1 and 12 _-2 are flyers, 13 _-1 and 13 _-2 are twisting and backflow prevention rollers, 14 is a twisting machine, 15 is a plate of the twisting machine, Reference numeral 16 denotes a twist port of the twisting machine.

Reel _{28-1, 8-2} respectively guide 9 _-1 metal filaments 1 and 3 is unwound from flyer 12 _-1 through 9 _-2 lead to _12-2, each flyer 12 _-1, 12 _-2 The metal filaments 2 and 4 supplied from the reels 11 _-1 and 11 _-2 are spirally wound around the outer periphery of the metal filaments 1 and 3 that have passed through the center guide. The winding directions of the metal filaments 2 and 4 at this time are opposite to each other. The reels 11 _-1 and 11 _-2 are fixed, and the metal filaments 2 and 4 fed out from the reels 11 _-1 and 11 _-2 are given a twist of one rotation per one rotation of the flyer, and thereby the metal The filaments 2 and 4 can be individually wound around the metal filaments 1 and 3, respectively. Since the winding pitches p ₁ and p ₂ of the metal filaments 2 and 4 are sequentially changed according to the winding amount of the reel around which the metal filaments are wound, the winding pitch p ₁ = 0.922P to 0.991P, the winding pitch. Winding is performed by adjusting the winding amount so that p ₂ = 1.010P to 1.085P.

Next, the two filament bundles 6a ₁ and 6a ₂ thus formed are respectively wound around the twisted backflow prevention rollers 13 _-1 and 13 _-2 in the shape of a slit, and then placed on the guide hole and the twisting port 16 of the eye plate 15. The wire is led to the twisting machine 14 and twisted by the twisting machine 14. Then, the metal cord 6 completed through the corrector 17 is wound around the reel 18. In addition to straightening and correcting the cord, the corrector 17 is not effective when the arrangement of the metal filaments is extremely unstable in the longitudinal direction of the cord (arrangement indicated by a chain line such as a _{2 at} the first pitch in FIG. 1). It also has the role of placing a stable metal filament in an appropriate arrangement.

Incidentally, for example when producing S-twist cord, the winding direction metallic filament 2 is twisted in the same direction code is rotated counterclockwise in plan view flyer 12 _-1 to metal filaments 1. Flyer 12 _-2 rotate in the opposite direction to the flyer 12 _-1.

The metal filaments 1 and 3 are preferably supplied by forcibly rotating the reels 8 _-1 and 8 _-2 so that twisting does not occur until they are twisted into a bundle.

The above description has been given by taking a 1 × 4 structure cord composed of four metal filaments as an example. However, as shown in FIG. 4, the present invention further includes one cord bundle 6 a ₁ and 6 a _2. 1 × 5 metal cord obtained by adding the metal filament 5 and twisting them with a predetermined twist pitch P is also included in the applicable range. Metal cord formed by the five metal filaments, metal filaments from a reel _8-3 to add the drive supply device 7 _-3 and set in the drive supply device 7 _-3 indicated by a chain line in the equipment of FIG. 3 5 is fed out and twisted together with _two filament bundles 6a ₁ and 6a ₂ to produce.

  Metal cord invention product (1) and invention product (2) of this invention (the product (2) satisfies the condition that the winding pitch of the filament and the twist angle of the cord are preferred), the conventional metal cord, and the present invention A comparative evaluation test of performance was performed using a comparison code (comparative product) that did not satisfy the above conditions. The results are summarized in Tables 1 and 2.

Of the conventional products shown in Tables 1 and 2, the corrugated cord is obtained by corrugating only one metal filament. The wave application conditions are as follows.
2-dimensional wavy wavy pitch: 4.7 mm (initial setting)
Corrugated height: 0.025 ± 0.005mm (after twisting)
Three-dimensional wavy wavy pitch: 1 / 2.5 x P (initial setting) P: Cord twist pitch
Corrugated height: 0.028 ± 0.005mm (after twisting)

  FIG. 6 shows a cross section of a 1 × 4 × d twisted structure cord with two-dimensional waves, FIG. 7 shows a cross section of a 1 × 5 × d twisted structure cord with two-dimensional waves, and FIG. FIG. 8 shows a cross section of a cord having a 4 × d twisted structure, and FIG. 9 shows a cross section of a cord having a 1 × 5 × d twisted structure with a three-dimensional wave.

-Description of characteristics in Tables 1 and 2-
(1) Code of residual torsion: reel 11 _-1 in Fig. 3, 11 _-2 winding amount metal cord and reel 11 _-1 which is created when a fully wound state, 11 winding amount remaining _-2 is low Occasionally, each of the metal cords prepared was measured 20 times, and the value of √V value in total of 40 measurements exceeding 0.7 was evaluated as x, less than 0.33 as ◯, and the intermediate range as △ And display. The measurement of residual torsion is based on the measurement method of JIS G 3510.
(2) Rubber penetration rate: After a sample was prepared by pressure vulcanization in rubber with a tension of 500 gf applied to a single metal cord, the cord in the rubber was taken out. Divided into 2 and 2 pairs of filament bundles, and 5 twisted cords are divided into 2 filament bundles and the other 3 bundles, which are broken down in the longitudinal direction to obtain measurement samples. Then, the degree of penetration of the rubber into the cord of this measurement sample was observed visually or with a magnifying glass, and 100% was observed where the rubber penetrated in the entire observation length.
(3) Compressive rigidity: In the pressure vulcanized sample prepared in (1), the rubber thickness outside the cord is cut to about 0.5 mm to obtain a measurement sample. The resistance value when this measurement sample was compressed to a predetermined stroke under the following conditions using a compression tester was examined, and a reference cord (No. 1 of 1 × 4 twist structure cord and No. 24 of Table 1) was measured. 1 x 5 twisted cord)
%.
Compression condition Grab interval: 50mm
Measurement displacement: 6mm
Compression speed: 10 mm / min

  From the test results of Table 1, it can be seen that the metal cord of the present invention is excellent in both rubber penetration and compression rigidity characteristics.

  Further, the metal cord of the present invention can be manufactured with a simple facility as shown in FIG. 3, and the facility cost and the manufacturing cost can be reduced.

Schematic diagram of a cross section of the four-stranded metal cord of the present invention cut in the longitudinal direction at intervals of 1/4 twist pitch The perspective view which shows the winding example of another one metal filament with respect to one metal filament of a filament bundle The conceptual diagram which shows the manufacturing method of the metal cord of this invention Sectional view of the five-strand metal cord of the present invention Definition of twist angle Cross section of a conventional cord with 2D wave 1 × 4 × d Cross-sectional view of a conventional cord with 2D wave 1 × 5 × d Cross-sectional view of a conventional cord with 3D wave 1 × 4 × d Cross-sectional view of a conventional 1x5xd cord with 3D wave

Explanation of symbols

1-5 metallic filaments 6 for reinforcing a rubber article metal cords 6a _1, 6a ₂ filament bundles 7 _-1 to 7 _-3 drive supply device 8 _-1 8 _-3 reel _9-1 to 9 _-3 guide 10 _-1, 10 _-2 dead supply device 11 _-1 , 11 _-2 reel 12 _-1 , 12 _-2 flyer 13 _-1 , 13 _-2 twist backflow prevention roller 14 twisting machine 15 dial plate 16 twist opening 17 straightener 18 reel

Claims (6)

  A first filament bundle in which another metal filament is spirally wound around one metal filament, and another metal filament in a direction opposite to the winding direction of the first filament bundle around one metal filament A metal cord for reinforcing rubber articles composed of four metal filaments formed by twisting together a second filament bundle wound in a spiral shape with a twist pitch P.   A first filament bundle in which another metal filament is wound spirally around one metal filament, and another metal filament on one metal filament opposite to the winding direction of the first filament bundle A metal cord for reinforcing rubber articles composed of five metal filaments obtained by twisting and twisting a second filament bundle wound in a spiral shape and another metal filament at a twist pitch P. The winding direction of another metal filament with respect to one metal filament of the first filament bundle is the same direction as the twisting direction of the cord, and the winding pitch p ₁ is relative to the twisting pitch P of the cord. ,
0.922 ≦ p ₁ /P≦0.991
The metal cord for reinforcing rubber articles according to claim 1 or 2, wherein the following formula is satisfied. A single direction opposite to the direction the twisting direction of the cord winding in the other one of the metal filaments to metal filaments of the second filament bundle, and the winding pitch p ₂ are, with respect to the twisting pitch P code ,
1.010 ≦ p ₂ /P≦1.085
The metal cord for reinforcing rubber articles according to any one of claims 1 to 3, which satisfies the following formula.   The metal cord for reinforcing rubber articles according to any one of claims 1 to 4, wherein the cord has a twist angle α ° in a range of 3.5 ° to 7.3 °.   One metal filament is passed through the center of the pass line, and another metal filament is spirally wound around the metal filament using a flyer, and the other metal filaments are wound in opposite directions. The obtained first filament bundle and second filament bundle, or the first and second filament bundles and yet another metal filament are introduced into a stranding machine and twisted at a twist pitch P. 4-5 A method for producing a metal cord for reinforcing rubber articles, which obtains a metal cord for reinforcing rubber articles composed of metal filaments.

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