JPH11100782A - Steel code and steel radial tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a steel code that is excellent in rubber penetrability and has a long life steel radial tires using the same. SOLUTION: This is a flat shaped steel code and is produced by twisting (n) wires having the same diameter (d) into a bundle (1×n) and is embedded into rubber molded products. When (n) is 3, one wire is waved in a different way from the shaping for code forming, while in the case that n=4-7, one wire or two wires that are not adjacent to each other, when twisted, are waved in a different way from the shaping for code forming.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel cord used for reinforcing a rubber molded body such as a steel radial tire or a conveyor belt, and a steel radial tire using the steel cord as a ply cord or a belt cord.

[0002]

2. Description of the Related Art Steel cords used to reinforce rubber moldings such as steel radial tires and conveyor belts have a cavity inside the cord, in which water penetrates and corrodes the wire, and the wire and rubber are separated. They are separated and cause so-called fretting, which causes disconnection.

[0003] Japanese Patent Publication No. 3-32555 discloses a steel cord having a flattened structure in order to improve the rubber permeability inside the cord.

[0004]

However, in the conventional flat-shaped steel cord, if the gap between the strands is small, the rubber permeability varies, so that
It is not easy to obtain sufficient rubber permeability. In particular, when the twist pitch exceeds 50 times the wire diameter, the shape stability becomes unstable, so that sufficient rubber permeability cannot be obtained.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a long-life steel cord and a steel radial tire excellent in rubber permeability without excessive flattening. And

[0006]

SUMMARY OF THE INVENTION A steel cord according to the present invention is used by being embedded in a rubber molding.
A flat-shaped steel cord having a configuration (1 × n) in which strands of the same diameter d are collectively twisted. When n = 3, one strand is different from shaping for cord formation. When the shape is corrugated, when n = 4 to 7, one strand or two strands that are not adjacent to each other when twisted are corrugated in a shape different from shaping for forming a cord. Is performed.

[0007] The steel radial tire according to the present invention comprises:
A flat steel cord having a configuration in which n wires of the same diameter d are twisted together (1 × n). When n = 3, one wire is shaped for forming the cord. In the case where n = 4 to 7, a single strand or two strands which are not adjacent to each other when twisted are shaped differently from the shaping for forming the cord. It is characterized by comprising a steel cord to which a steel cord is attached and a rubber molded member in which the steel cord is embedded as a ply cord or a belt cord.

In the above steel cord, when the corrugated shape is a two-dimensional corrugated shape and the displacement size of the corrugated shape different from the corrugated shape for forming the cord is d1, the inequality d + (1) / 100) ≦ d1 ≦ d + (4/1
It is preferable to satisfy the relationship 0).

It is preferable that the ratio between the minor axis D1 and the major axis D2 of the cord satisfies the relation of inequality 0.40 ≦ D1 / D2 <0.60.

As the corrugating process of the wires, a gear crimping process is used in which the wires are bitten one by one between the crimp gears and deformed two-dimensionally.

Further, it is desirable to use a high-tensile steel wire having a tensile strength of 280 to 400 kgf / mm ² class for the wire constituting the cord. In order for the steel cord to obtain the desired breaking strength, the tensile strength of the wire must be 280 kgf / mm ^2.
This is because it is necessary to do the above. On the other hand, if the tensile strength of the wire exceeds 400 kgf / mm ² , the wire becomes brittle and the wire is easily broken.

The constituent wire has a carbon content of 0.7.
It is desirable to use a high-tensile steel wire of 0 to 1.00% by weight. This is because in order for the steel cord to obtain a desired breaking strength, the carbon content of the wire needs to be 0.70% by weight or more. On the other hand, if the carbon content of the wire exceeds 1.00% by weight, the wire becomes brittle and the wire is likely to break.

The diameter of the wire is 0.10 to 0.40 mm
Range. When the wire diameter is less than 0.10 mm, a desired strength level cannot be obtained. On the other hand, if the wire diameter exceeds 0.40 mm, the fatigue properties deteriorate.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
First, a manufacturing apparatus for manufacturing a steel cord according to the present invention will be described with reference to FIGS.

As shown in FIG. 1, the steel cord manufacturing apparatus includes a wire supply unit 10 and a stranded wire unit 20. The wire supply unit 10 is provided with three supply reels 11. The wires 3 are synchronously fed from the respective supply reels 11 toward the stranded portion 20.

Between the supply reel 11 and the stranded wire portion 20, three shaping devices 13, a head plate 14, and a voice 1
8 are provided in this order. A gear crimping machine 12 having a crimp gear is provided between one of the supply reels 11 and the shaping device 13. One wire 3 is two-dimensionally corrugated by the gear crimping machine 12 to be a crimped wire 3a. As shown in FIG. 3, the two-dimensional corrugated height h by the gear crimping machine 12 is d + (1/10
0) ≦ d1 ≦ d + (4/10) mm
And the corrugated pitch P is 10d ≦ P ≦
It is desirable to set an appropriate value within the range of 50 dmm according to the wire diameter d.

Here, "shaping" refers to forming a three-dimensional helical habit required for cord forming by applying a stress exceeding the elastic limit to the wire before being twisted. "Shaping" refers to shaping a wire two-dimensionally in a wave shape different from "shaping". FIG. 3 shows an example of corrugation. Assuming that the wire diameter d, the corrugated pitch P, and the displacement from the wire center of the trough 7 to the wire center of the crest 8 are h,
The corrugation dimension d1 has a relationship of d1 = h + d.

As shown in FIGS. 2A and 2B, in the shaping device 13, the wire 3 is passed in a slalom shape between three pins 13b erected on the base plate 13a. In addition, the twist is transmitted to the wire by the rotation of 20, and the wire 3 having a spiral three-dimensional shape is obtained.

The wires 3 and 3a are bundled together by a voice 18 after passing through the end plate 14, and enter the stranded portion 20 as one wire bundle.

As shown in FIG. 4, three holes 15 are
4 are formed at equal pitch intervals on the periphery. These three
After the crimped and open-formed one wire 3a and the open-shaped only two wires 3 pass through the two holes 15, respectively, they are bundled together by the voice 18 after being passed through. I have.

The stranded wire portion 20 is a buncher type stranded wire machine provided with a fryer bow 21, a twist roll 22, a flattening device 24, a take-up reel 29 and the like. As a result, the three wires 3 a and 3 that have passed through the voice 18 are twisted together and wound on the take-up reel 29.

As shown in FIG. 6, the flattening device 24 is provided with fixed rollers 26 arranged at equal intervals on a base 25, and a movable roller 28 in the middle of which can adjust the amount of pushing individually by adjusting screws 27. I have. As shown in FIG. 7, when the adjusting screw 27 is turned, the movable roller 28 is turned into the slit guide groove 2.
It moves along 7a. As shown in FIG. 8, the roller 26 is a flat roller having an ear 26a for preventing the cord from coming off, and the roller 28 is, as shown in FIG.
Rollers having a flat peripheral surface 28a are arranged in a zigzag pattern. The roller 28 can be freely adjusted in the amount of pushing by the adjusting screw 27, so that the roller 2 is appropriately pressed against the cord 2A and the cord 2A is flattened.

Next, various examples and comparative examples will be described. Each data is as shown in Table 1.

Example 1 A high-tensile wire having a carbon content of 0.82% (weight) was drawn to have a strength of 340 kfg / m.
A steel cord 2A having a (1 × 3) configuration shown in FIG. 10 was manufactured using the above-described manufacturing apparatus, using an elemental wire having an m ² diameter of 0.28 mm. The two-dimensional shaping dimension d1 by the crimping machine is d + (1/100) ≦ d1 ≦ d + (4 /
10) Within the range of mm, set an appropriate value according to the wire diameter d,
It is desirable that the corrugation pitch P be an appropriate value within the range of 10d ≦ P ≦ 50dmm according to the wire diameter d.

The steel cord manufacturing conditions and product sizes of Example 1 are shown below.

3 Total number of wires n; 3 Number of shaping nk; 1 Wire diameter d; 0.28 mm Corrugation dimension d1; 0.42 mm Corrugation pitch P; 3.7 mm Twist pitch Pw; 14 mm Twist direction; Twisted cord flatness: 58% [(D1 / D2) × 100] (Comparative Example 1) Using the same strand as in Example 1, without using the crimping machine of the above manufacturing apparatus, (1 × 3) configuration Was produced.

The steel cord production conditions and product size of Comparative Example 1 are shown below.

Total number of wires n; 3 Number of shaping nk; 0 Wire diameter d; 0.28 mm Wave size d1;-Wave pitch P;-Twist pitch Pw; 14 mm Twist direction; S twist Cord flatness 57% [(D 1 / D 2) × 100] (Example 2) A high-tensile wire having a carbon content of 0.82% (weight) was drawn to have a strength of 340 kgf / mm ² and a diameter of 0.3 mm.
A steel cord 2B having a (1 × 4) configuration shown in FIG. 11 was produced by using a device similar to the above-described production device using a 20 mm wire. The two-dimensional corrugation dimension d1 by the crimping machine is d + (1/100) ≦ d1 ≦ d + (4/1
0) It is desirable to set an appropriate value according to the wire diameter d within the range of mm, and the shaping pitch P to an appropriate value according to the wire diameter d within the range of 10d ≦ P ≦ 50 mm.

The steel cord production conditions and the product size of Example 2 are shown below.

4 Total number of wires n; 4 Number of shaping nk; 2 Wire diameter d; 0.20 mm Corrugation dimension d1; 0.36 mm Corrugation pitch P; 3.6 mm Twist pitch Pw; 10 mm Twist direction; Twisted cord flatness: 54% [(D1 / D2) × 100] (Comparative Example 2) Using the same strand as in Example 2, without using the crimping machine of the manufacturing apparatus of Example 2, (1 × 4) A steel cord having the configuration was manufactured.

The steel cord manufacturing conditions and product size of Comparative Example 2 are shown below.

Total number of wires n; 4 Number of shaping nk; 0 Wire diameter d; 0.20 mm Corrugation size d1;-Corrugation pitch P;-Twist pitch Pw; 10 mm Twist direction; S-twist Cord flatness 56% [(D1 / D2) × 100] (Embodiment 3) Using the same strands as in Embodiment 2 and using an apparatus similar to the above manufacturing apparatus, the (1 × 5) configuration shown in FIG. Steel cord 2C was produced. The two-dimensional corrugation dimension d1 by the crimping machine is d + (1/100) ≦ d
Within the range of 1 ≦ d + (4/10) mm, an appropriate value is set according to the wire diameter d, and the shaping pitch P is 10d ≦ P ≦ 50 dmm
It is desirable to set an appropriate value within the range according to the wire diameter d.

The steel cord manufacturing conditions and the product size of Example 3 are shown below.

5 Total number of wires n; 5 Number of shaping nk; 2 Diameter of wire d; 0.20 mm Corrugated dimension d1; 0.36 mm Corrugated pitch P; 3.7 mm Twist pitch Pw; 10 mm Twist direction; Twisted cord flatness: 54% [(D1 / D2) × 100] (Comparative Example 3) Using the same strand as in Example 2, without using the crimping machine of the manufacturing apparatus of Example 3, (1 × 5) A steel cord having the configuration was manufactured.

The steel cord production conditions and product size of Comparative Example 3 are shown below.

5 total number of wires n; 5 number of shaping nk; 0 diameter of wire d; 0.20 mm corrugation dimension d1; corrugation pitch P;-twist pitch Pw; 10 mm twist direction; 55% [(D 1 / D 2) × 100] (Example 4) A steel cord having a (1 × 6) configuration is manufactured using the same strand as in Example 2 and using an apparatus similar to the above manufacturing apparatus. did. The two-dimensional corrugation dimension d1 by the crimping machine is d + (1/100) ≦ d1 ≦ d + (4/1
0) It is desirable to set an appropriate value according to the wire diameter d within the range of mm, and the corrugation pitch P to an appropriate value according to the wire diameter d within the range of 10d ≦ P ≦ 50 mm.

The steel cord manufacturing conditions and product sizes of Example 4 are shown below.

6 total number of wires n; 6 number of shaping nk; 1 wire diameter d; 0.20 mm corrugation dimension d1; 0.34 mm corrugation pitch P; 3.6 mm twist pitch Pw; 10 mm twist direction; Twisted cord flatness: 53% [(D1 / D2) × 100] (Comparative Example 4) Using the same strand as in Example 2, without using the crimping machine of the manufacturing apparatus of Example 4, (1 × 6) A steel cord having the configuration was manufactured.

The steel cord manufacturing conditions and product size of Comparative Example 4 are shown below.

6 total number of wires n; 6 number of shaping nk; 0 diameter of wire d; 0.20 mm corrugation dimension d1; corrugation pitch P;-twist pitch Pw; 10 mm twist direction; 52% [(D1 / D2) × 100] (Embodiment 5) Using the same wires as in Embodiment 2 and using an apparatus similar to the above-described manufacturing apparatus, the (1 × 6) configuration shown in FIG. Steel cord 2D was produced. The two-dimensional corrugation dimension d1 by the crimping machine is d + (1/100) ≦ d
An appropriate value is set according to the wire diameter d within a range of 1 ≦ d + (4/10) mm, and a corrugation pitch P is 10d ≦ P ≦ 50 dmm.
It is desirable to set an appropriate value within the range according to the wire diameter d.

The steel cord manufacturing conditions and product size of Example 5 are shown below.

6 Total number of wires n; 6 Number of shaping nk; 2 Diameter of wire d; 0.20 mm Corrugation dimension d1; 0.34 mm Corrugation pitch P; 3.6 mm Twist pitch Pw; 10 mm Twist direction; S Twisted cord flatness: 52% [(D1 / D2) × 100] (Comparative Example 5) Using the same strand as in Example 2, using a device similar to the above-described manufacturing device, (1 × 6) configuration A steel cord was made. The two-dimensional corrugation dimension d1 by the crimping machine is d + (1/100) ≦ d1 ≦ d + (4/1
0) It is desirable to set an appropriate value according to the wire diameter d within the range of mm, and the corrugation pitch P to an appropriate value according to the wire diameter d within the range of 10d ≦ P ≦ 50 mm.

The steel cord production conditions and product size of Comparative Example 5 are shown below.

6 Total number of wires n; 6 Number of shaping nk; 3 Wire diameter d; 0.20 mm Corrugation dimension d1; 0.34 mm Corrugation pitch P; 3.6 mm Twist pitch Pw; 10 mm Twist direction; S Twisted cord flatness: 53% [(D1 / D2) × 100] (Comparative Example 6) Using the same strand as in Example 2 and using a device similar to the above-described manufacturing apparatus, a (1 × 6) configuration A steel cord was made. The two-dimensional corrugation dimension d1 by the crimping machine is d + (1/100) ≦ d1 ≦ d + (4/1
0) It is desirable to set an appropriate value according to the wire diameter d within the range of mm, and the corrugation pitch P to an appropriate value according to the wire diameter d within the range of 10d ≦ P ≦ 50 mm.

The steel cord manufacturing conditions and product size of Comparative Example 6 are shown below.

6 Total number of wires n; 6 Number of shaping nk; 4 Wire diameter d; 0.20 mm Corrugation dimension d1; 0.34 mm Corrugation pitch P; 3.6 mm Twist pitch Pw; 10 mm Twist direction; Twisted cord flatness: 54% [(D1 / D2) × 100] (Comparative Example 7) Using the same strand as in Example 2, using an apparatus similar to the above-described manufacturing apparatus, (1 × 6) A steel cord was made. The two-dimensional corrugation dimension d1 by the crimping machine is d + (1/100) ≦ d1 ≦ d + (4/1
0) It is desirable to set an appropriate value according to the wire diameter d within the range of mm, and the corrugation pitch P to an appropriate value according to the wire diameter d within the range of 10d ≦ P ≦ 50 mm.

The steel cord production conditions and the product size of Comparative Example 7 are shown below.

6 Total number of wires n; 6 Number of shaping nk; 5 Wire diameter d; 0.20 mm Corrugation dimension d1; 0.34 mm Corrugation pitch P; 3.6 mm Twist pitch Pw; 10 mm Twist direction; S Twisted cord flatness: 52% [(D1 / D2) × 100] (Comparative Example 8) Using the same strand as in Example 2, using a device similar to the above-described manufacturing device, (1 × 6) configuration A steel cord was made. The two-dimensional corrugation dimension d1 by the crimping machine is d + (1/100) ≦ d1 ≦ d + (4/1
0) It is desirable to set an appropriate value according to the wire diameter d within the range of mm, and the corrugation pitch P to an appropriate value according to the wire diameter d within the range of 10d ≦ P ≦ 50 mm.

The steel cord production conditions and product size of Comparative Example 8 are shown below.

6 Total number of wires n; 6 Number of shaping nk; 6 Wire diameter d; 0.20 mm Corrugated dimension d1; 0.34 mm Corrugated pitch P; 3.6 mm Twist pitch Pw; 10 mm Twist direction; S Twisted cord flatness: 52% [(D1 / D2) × 100] (Embodiment 6) Using the same strands as in Embodiment 2, using an apparatus similar to the above-described manufacturing apparatus, FIG. 7) A steel cord having the configuration was manufactured. The two-dimensional corrugation dimension d1 by the crimping machine is d + (1/100) ≦ d1 ≦
It is preferable to set an appropriate value according to the wire diameter d within a range of d + (4/10) mm, and to set an appropriate value according to the wire diameter d within a range of 10d ≦ P ≦ 50 dmm. .

The steel cord production conditions and product size of Comparative Example 6 are shown below.

7 Total number of wires n; 7 Number of shaping nk; 2 Diameter of wire d; 0.20 mm Corrugation dimension d1; 0.34 mm Corrugation pitch P; 3.6 mm Twist pitch Pw; 10 mm Twist direction; Twisted cord flatness: 50% [(D1 / D2) × 100] (Comparative Example 9) Using the same strand as in Example 2, without using the crimping machine of the manufacturing apparatus of Example 6 (1 × 7) A steel cord having the configuration was manufactured.

The steel cord production conditions and product size of Comparative Example 9 are shown below.

7 Total number of wires n; 7 Number of shaping nk; 0 Wire diameter d; 0.20 mm Corrugation dimension d1; 0.34 mm Corrugation pitch P; 3.6 mm Twist pitch Pw; 10 mm Twist direction; S Twisted cord flatness: 51% [(D1 / D2) × 100] [Evaluation of rubber permeability] The steel cords of Examples 1 to 6 above were compared with those of Comparative Examples 1 to 9 by rubber penetration as follows. Each was evaluated for gender.

First, a steel cord having a length of 10 pitches is prepared for each of Examples 1 to 6 and Comparative Examples 1 to 9. The side wire of each cord is peeled off, and the wire forming the heart is visually inspected with the naked eye for a total of 20 rubber penetration states at each of the front and back.

For the visual inspection, a point system was adopted. 50 points for the front and 50 points for the back, where 5 points where the rubber has completely penetrated, 2.5 points where the rubber has penetrated about half, and 0 points where the rubber has not penetrated. Each of them was examined for a total of several points. The rubber permeability was evaluated by displaying this as a percentage. Those having a rubber permeability of 80% or more were judged to be acceptable.

In all of Examples 1 to 6, the rubber permeability is as good as 90% or more. On the other hand, among the comparative examples, comparative examples 1, 2, and 2, which did not include the crimped wire.
The codes 3, 4, and 9 are 55 to 70%, which is not a satisfactory value.

On the other hand, Comparative Examples 5, 6, 7, and 8 contain 3 to 6 crimped wires and have good rubber permeability.

[Evaluation of Tensile Strength] Since a certain angle (θ) is generated between the tension axis direction and the wire axis direction by crimping the wire, the force in the tension axis direction is equal to the force in the wire axis direction. Is expressed as F · cos θ,
Since F · cos θ ≦ F, the strength decreases.

Comparative Examples 4, 5, 6, 7, 8 and Example 4,
5 shows the number of crimps and the cutting load, but the cutting load decreases as the number of crimps increases.

Therefore, the smaller the number of crimps, the higher the cutting load.

From the above results, the steel cords of the examples are very excellent in rubber permeability and have a small decrease in tensile strength, and are very good as rubber reinforcing agents.

[0063]

[Table 1]

[0064]

As described above, in the steel cord of the present invention, a very stable high rubber permeability can be obtained, and the cutting load can be reduced by limiting the number of crimps according to the number of cords. Can be minimized. Therefore, the life of a steel radial tire using this steel cord as a reinforcing material is reduced and greatly extended.

[Brief description of the drawings]

FIG. 1 is an overall schematic view schematically showing a stranded wire machine used for manufacturing a steel cord according to the present invention.

FIG. 2A is a plan view showing an apparatus for forming an open wire, and FIG. 2B is a side view showing an apparatus for forming an open wire.

FIG. 3 shows a crimped wire (d1 = h +
The schematic diagram which shows d).

FIG. 4 is a front view showing an end plate for three twists.

FIG. 5 is a front view showing a four-strand end plate.

FIG. 6 is an overall view showing an outline of a flattening device.

FIG. 7 is a partial cross-sectional view of the flattening device with a part cut away.

FIG. 8 is a view showing a flat roll with ears of the flattening device.

FIG. 9 is a view showing a flattening roll of the flattening device.

FIG. 10 shows a steel cord (1 ×) according to an embodiment of the present invention.
FIG.

FIG. 11 shows a steel cord (1 ×) according to an embodiment of the present invention.
FIG.

FIG. 12 shows a steel cord (1 ×) according to an embodiment of the present invention.
FIG.

FIG. 13 shows a steel cord (1 ×) according to an embodiment of the present invention.
FIG.

FIG. 14 shows a steel cord (1 ×) according to an embodiment of the present invention.
FIG.

[Explanation of symbols]

2A, 2B, 2C, 2D, 2E ... steel cord, 3,
3a, 3b, 3c, 3d, 3e: wire, 7: valley, 8
... Mountain part, 10 ... Wire supply part, 11 ... Supply reel,
12 ... crimping machine, 13 ... open forming device, 1
4, 14A: end plate, 18: voice (die), 20: stranded wire portion, 24: flattening device, 29: take-up reel.

Claims (6)

[Claims] 1. A flat steel cord having a configuration (1 × n) in which n element wires having the same diameter d used by being embedded in a rubber molded body are collectively twisted, wherein n = 3. In the case of n = 4 to 7, when one strand is twisted, two strands which are not adjacent to each other when one strand is twisted are formed. A steel cord, wherein the strand has a shape different from that for forming the cord. 2. An inequality d + (1/10) where a corrugated shape is a two-dimensional corrugated shape and a displacement size of corrugation having a shape different from shaping for forming a code is d1.
2. The steel cord according to claim 1, wherein a relationship of 0) ≦ d1 ≦ d + (4/10) is satisfied. 3. The steel cord according to claim 1, wherein the ratio between the minor axis D1 and the major axis D2 of the cord satisfies the relationship of inequality 0.40 ≦ D1 / D2 <0.60. 4. Twisting n wires of the same diameter d together (1
× n) a flat steel cord having a configuration, wherein n =
In the case of 3, one strand is corrugated in a shape different from the shaping for forming the cord, and when n = 4 to 7, it is not adjacent to one strand when twisted. A steel cord in which two strands are corrugated in a shape different from the shaping for forming the cord, and a rubber molded member in which the steel cord is embedded as a ply cord or a belt cord. A steel radial tire characterized by: 5. The steel cord has an inequality d + (2 + 2) where a corrugated shape is a two-dimensional corrugated shape and a displacement size of a shaping different from shaping for forming a cord is d1. The steel radial tire according to claim 4, wherein a relationship of (1/100) ≤d1≤d + (4/10) is satisfied. 6. The steel cord according to claim 6, wherein the minor diameter of the cord is D.
The ratio of 1 to the major axis D2 is inequality 0.40 ≦ D1 / D2 <
The steel radial tire according to claim 4, wherein a relationship of 0.60 is satisfied.