JPH06182433A - Manufacture of bead wire - Google Patents

Abstract

PURPOSE:To drastically reduce residue on the surface of a drawn wire without deteriolating the wire drawing properties in manufacture of a bead wire. CONSTITUTION:In the manufacture of the bead wire having a wire diameter of >=0.7mm which contains 0.6-0.9% carbon and is subjected to wire drawing of 8.0-9.5% total reduction rate of area in the final wire drawing, zinc phosphate film treatment is applied as a pretreatment of wire drawing, and dry lubricant made mainly from sodium soap and dry lubricant made mainly from calcium soap are used jointly as a wire drawing lubricant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a bead wire used in a pneumatic rubber tire used in automobiles, bicycles and the like.

[0002]

2. Description of the Related Art Conventionally, a method of manufacturing a bead wire has been generally performed as follows. The hot-rolled wire is repeatedly subjected to wire drawing and patenting treatments, and in the final wire drawing, quality such as wire diameter, strength, twist value, and straightness as a product is given. After that, in order to improve the corrosion resistance as a bead wire and to adhere it to rubber, the surface is plated with copper, brass, bronze or the like to obtain the final product.

This wire drawing is carried out by using a wire drawing machine as shown in FIG. 1 to easily perform die drawing, and in order to secure the mechanical quality after wire drawing, a dry method generally containing calcium soap as a main component. Uses a lubricant. In addition, in order to enhance the effect of this lubricant, the surface of the wire is treated with a zinc phosphate coating before drawing.

[0004]

[Problems to be Solved by the Invention] The zinc phosphate coating treatment is
Since the lubricant is well retained on the surface of the wire, it exhibits excellent wire drawability during die drawing. However, even after drawing, a large amount of zinc phosphate coating and lubricant remain on the surface.

The present inventor has conducted extensive studies on the residual zinc phosphate coating and the like (hereinafter referred to as "residue"), and as a result, the residue has a very bad effect on the plating treatment applied to the surface thereafter and the adhesion with rubber. Found to give. The residue hinders the strong adhesion between the wire and the plating metal, causing the plating to peel and causing rust. In addition, the residue leaks to the surface due to pinholes and the like formed on the plated surface, and the adhesive force with the rubber is reduced. Such a phenomenon becomes a serious defect in the quality of the bead wire.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is not to impair the wire drawability.
It is an object of the present invention to provide a method for manufacturing a bead wire, which greatly reduces the residue on the surface of the wire after drawing.

[0007]

[Means for Solving the Problems] After the zinc phosphate coating treatment, if wire drawing is performed using a dry lubricant containing calcium soap as a main component, the wire drawability is very good, but a large amount of residue remains on the wire surface. Exists. On the other hand, after the zinc phosphate coating treatment, if wire drawing is performed using a dry lubricant containing sodium soap as the main component,
Wire drawability is poor and wire drawing becomes impossible. For this reason,
No dry lubricant containing sodium-based soap as a main component was used for the wire treated with the zinc phosphate coating. However, there was also an advantage that almost no residue was present on the wire surface.

After confirming these matters, after the zinc phosphate coating treatment, wire drawing was performed using a dry lubricant containing sodium soap as a main component and a dry lubricant containing calcium soap as a main component in combination. As a result, it was confirmed that there was almost no residue on the wire surface after the wire drawing, while maintaining high wire drawability, and the present invention was accomplished.

That is, in the present invention, the C content is 0.6 to 0.9%.
In a method for producing a bead wire having a wire diameter of 0.7 mm or more, in which wire drawing is performed with a total area reduction rate of 80% to 95% in the final wire drawing, a zinc phosphate coating treatment is performed as a pretreatment of wire drawing, As the line lubricant, a dry lubricant containing sodium soap as a main component and a dry lubricant containing calcium soap as a main component are used together.

[0010]

Since the present invention has the above-mentioned constitution, the dry lubricant containing calcium-based soap as a main component is well retained by the zinc phosphate coating and has good wire drawability, and the dry-type lubricant containing sodium-based soap as a main component. Is not retained so much in the zinc phosphate coating, so that the zinc phosphate coating itself falls off. But,
Once the dry lubricant containing calcium-based soap as a main component is held on the wire surface together with the zinc phosphate coating, the wire drawability does not decrease so much even if the zinc phosphate coating falls off a little. Therefore, it is considered that the residue on the surface of the drawn wire can be greatly reduced while maintaining good wire drawability.

As a method of using a dry lubricant containing sodium soap as a main component and a dry lubricant containing calcium soap as a main component in combination, the following method is preferable.

For example, when eight dies are used as shown in FIG. 1, the first die (3) to the fourth die (7) are dried by using a dry lubricant containing calcium soap as a main component. , The fifth die (8) to the eighth (final finish) die (11) use a dry lubricant containing sodium soap as a main component. Further, a dry lubricant containing calcium soap as a main component is used in the first (3), third (6), fifth (8), and seventh (10) dies, and the second (5), fourth (4)
(7), 6th (9), 8th (11) dies use a dry lubricant containing sodium soap as a main component. Moreover,
It is conceivable that a lubricant containing calcium soap as a main component and a lubricant containing sodium soap as a main component are mixed and used in each die. However, in each case, at least 10% of the total amount of each type of lubricant is used.

In the present invention, the amount of C is 0.6 to 0.9.
%, The total area reduction rate is 80% to 95%, and the wire diameter is limited to 0.7 mm or more in order to perform a zinc phosphate coating treatment as a pretreatment and to draw with a lubricant containing calcium soap as a main component. Is suitable for wire drawability with a C content of 0.6% or more and a total surface reduction rate of 80% or more. At the same time, since a lubricant containing sodium-based soap as a main component is used, the C content is 0.9%, This is because, if the area reduction ratio exceeds 95% and the finished wire diameter is less than 0.7 mm, the wire drawability is deteriorated, the roughness of the wire surface is increased, and the quality of the bead wire is too problematic.

[0014]

EXAMPLES Examples of the present invention will be described below. Wire diameter 5.
Patented 0mm SWRH72A material,
After pickling, zinc phosphate coating treatment was performed. The coating amount of zinc was 0.247 g per 1 kg of wire. This wire was drawn with eight dies by the wire drawing machine shown in FIG. 1 to a wire diameter of 1.55 mm by the following methods.

As the lubricant, a dry lubricant containing calcium-based soap as a main component was used. The first, third, fifth, and seventh dies are made of a dry lubricant containing calcium-based soap as a main component, and the second, fourth, sixth,
A dry lubricant containing sodium soap as a main component was used in the eighth die. A dry lubricant containing calcium soap as the main component was used in the first and second dies, and a dry lubricant containing sodium soap as the main component was used in the third to eighth dies. A dry lubricant containing sodium-based soap as a main component was used. Table 1 shows the zinc coverage after wire drawing and the weight ratio of the finished die.
It was like.

[0016]

[Table 1]

In Table 1, the zinc adhesion amount is a substitute value for the adhesion amount of the zinc phosphate coating, and is a value obtained by dissolving the wire in a 20% nitric acid solution and analyzing the absorption of the base paper.

Next, a bead wire was manufactured by subjecting each of the above samples to bronze plating treatment (Sn 10%, Cu deposition amount 0.4 g / kg). After this bead wire was embedded in rubber for tires and vulcanized, an adhesion test was conducted.
The result is shown in FIG.

The adhesion test method is ASTM D1871.
-68 indicates the area ratio in which the surface of the wire was covered with rubber. The test rubber is 100 parts by weight of carbon, 6 parts by weight of sulfur, and 1 part of zinc based on 100 parts by weight of the rubber polymer.
A mixture of 2 parts by weight and 2 parts by weight of stearic acid was used.

As can be seen from Table 1 and FIG. 2, sample No. 2 using a dry lubricant containing calcium soap as a main component and a dry lubricant containing sodium soap as a main component was used in combination. 2,
The wire No. 3 is sample No. 3 using only a dry lubricant containing calcium soap as a main component. The amount of zinc deposited was much less than that of the wire of No. 1, and sample No. 1 using only the dry lubricant containing sodium soap as the main component. It is close to the amount of wire 4 attached. However, the thick die is the same as sample No. Remarkably less than four. For bead wires with bronze plating on the surface, sample N
o. It can be seen that a few of those with rubber are good and have excellent adhesion with rubber.

[0021]

EFFECTS OF THE INVENTION Since the present invention has the above-mentioned constitution, in the final wire drawing step of the bead wire, the zinc phosphate coating, the lubricant, etc. remaining on the wire surface of the ascending wire are widely used while ensuring good wire drawability. Can be reduced to Therefore, plating on the surface of the wire can be made strong, problems such as peeling and rust are solved, and adhesion to rubber is improved, resulting in remarkably excellent effects.

[Brief description of drawings]

FIG. 1 is a schematic view showing a wire drawing machine used for manufacturing a bead wire.

FIG. 2 is a diagram showing a result of a test with an adhesive rubber of each sample.

[Explanation of symbols]

 1. Feeding device 2. Wire 3. First die 4. Take-up pot 5. Second die 6. Third Dice 7. Fourth Dice 8. Fifth Dice 9. Sixth Dice 10. 7th die 11. Eighth (final finish) die 21. Winding device

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Claims (1)

[Claims] 1. A method for producing a bead wire having a wire diameter of 0.7 mm or more, which comprises a C content of 0.6 to 0.9% and is subjected to wire drawing with a total area reduction rate of 80% to 95% in final wire drawing. Characterized in that a zinc phosphate coating treatment is performed as a pretreatment for wire drawing, and that a dry lubricant containing sodium soap as a main component and a dry lubricant containing calcium soap as a main component are used together as a wire drawing lubricant. Manufacturing method of bead wire.