KR101561304B1

KR101561304B1 - Single wire steel cord

Info

Publication number: KR101561304B1
Application number: KR1020090065400A
Authority: KR
Inventors: 이형은
Original assignee: 주식회사 효성
Priority date: 2009-07-17
Filing date: 2009-07-17
Publication date: 2015-10-16
Also published as: KR20110007781A

Abstract

The present invention relates to a single wire steel cord characterized by comprising a corrugated area and a non-corrugated area having an elongation of 3 to 5% and comprising one or a plurality of corrugations.

Single wire steel cord, elongation, waveform

Description

Single wire steel cord

The present invention relates to a single-strand steel cord used for reinforcing rubber products of pneumatic tires with enhanced strength and elongation and improved rubber adhesion.

In recent years, studies on improvement of automobile fuel efficiency have been actively carried out for various reasons such as protecting the global environment, and for this purpose, weight reduction of tires is being promoted. Therefore, it is urgent to develop a thin single-wire steel cord with a small thickness.

In the radial tire belt layer for passenger cars, a 1 × n twisted steel cord is generally used, and the steel cord having such a structure has high rigidity. On the other hand, when the road surface is uneven, the reaction force of the tire becomes too strong, not. In addition, it is easy to make a crack on the surface of the tread, and rainwater or the like intrudes into the tire from the crack, so that the cord wire corrodes early. In addition, when the tire is deformed or vibrated, so-called fretting wear occurs in which the twisted wires are rubbed against each other to cause wear, which tends to cause fatigue fracture of the cord wire.

To solve these problems, it has been proposed to use a single-wire steel cord fabricated by processing a single filament instead of a steel cord manufactured by twisting a plurality of strands into a belt layer of a tire. This is because the single wire steel cord is more plastic than the twisted steel cord.

However, in a single wire steel cord in which a cord of a conventional twisted wire structure (1 x n) or a section of a filament is circular, mechanical characteristics such as a wire material factor and a wire drawing machine or a twisted wire machine, There is a problem that the rotational property and the linearity of the rotor are largely changed. Particularly, since the rotational property is fluctuating, inspection is performed for each product even at a general quality assurance level.

Accordingly, a single wire steel cord whose cross section is not circular has been proposed. Japanese Laid-open Patent Application No. 11/143234 discloses a method of processing a flat single-strand steel cord into a wave shape to improve the straightness and rotability of the steel cord. In Korean Patent No. 10-0318896, twist is applied to the flattened single-stranded steel cord itself to improve the adhesive strength. In addition, in 10-0567812, twisted stress is given to a flattened single-stranded steel cord so that it is twisted in a spiral shape at regular intervals, thereby improving the characteristics such as adhesive strength and elongation.

As described above, flat single-line steel codes are mainly used instead of circular single-line steel codes at present.

It is an object of the present invention to improve the properties such as rotation and elongation at break, to improve the impact resistance by the bending motion of the tire, (AH) and adhesive strength, and can improve workability, and a method for producing the same.

In order to solve the above-mentioned problems, the present invention provides a single wire still code, characterized in that it includes a waveform area and a non-waveform area having an elongation of 3 to 5% and including one or a plurality of waveforms.

The single-wire steel cord according to the present invention has an effect of improving the impact resistance strengthening effect and the adhesive force by the bending motion of the tire due to an increase in the elongation at break of the cord, and the productivity during the product manufacturing stage is improved.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, the length, the diameter, the number of waveforms, and the like may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a view showing an embodiment of a single wire steel cord of the present invention. FIG.

Referring to FIG. 1, the single wire steel cord 10 of the present invention includes a waveform region 110 and a non-waveform region 120 including one or a plurality of waveforms. Although not shown in the drawing, the single wire steel cord 10 of the present invention has an elongation of 3 to 5%. The elongation is improved due to the corrugated area, and when the elongation satisfies the above-mentioned range, the rubber adhesion is improved. However, if the elongation exceeds the above-mentioned range, the height of the corrugation becomes 300% or more of the cord diameter due to an excessive shape during the production of the steel cord, which may cause problems such as overlapping between the cords during the rubber topping operation have. If the elongation is less than the above-mentioned range, belt edge separation phenomenon may occur.

It is preferable that the waveform region 110 and the non-wobble region 120 of the single wire steel cord 10 are repeated at a length ratio of 1: 9 to 9: 1. If the above-mentioned length ratio is satisfied, there is an advantage that the linearity and elongation adjustment can be more easily performed. It is preferable that each of the waveform area 110 and the non-wobble area 120 of the single wire steel cord satisfies the above-described length ratio, respectively, from 1 to 100 mm.

In addition, the waveform region 110 preferably includes 1 to 100 waveforms 110a, and more preferably includes 1 to 10 waveforms 110a. When the above-described range is satisfied, there is an advantage that the linearity and the electromagnetism can be easily adjusted.

The waveform 110a preferably has a height h of 0.30 mm to 3.0 mm and a period t of 1 mm to 10 mm. When the above-mentioned range is satisfied, there is an advantage that the product of desired elongation can be produced in the present invention.

It is preferable that the single wire steel cord 10 has a mold rate of 150 to 300%. If the above range is satisfied, the straightness adjustment can be made easily and the adhesiveness can be improved.

※ Shape ratio = h (height of waveform) / d (diameter) × 100

It is preferable that the wire diameter of the single wire steel cord 10 is 0.10 mm to 1.0 mm. If the above range is satisfied, desired breaking strength and weight reduction can be realized in the tire.

The single wire steel cord 10 preferably has a tensile strength of 270 to 480 kg / mm 2 and a carbon content of 0.7 to 2%.

Hereinafter, a method for manufacturing a single wire steel cord of the present invention will be described.

2 and 3 are views showing a method for manufacturing a single wire steel cord of the present invention.

Referring to FIG. 2, a filament 10a having a carbon content of 0.7% to 2%, a tensile strength of 270 to 480 kg / mm 2 and a diameter (d) of 0.1 mm to 1 mm is provided.

The filament 10a may be formed by first drawing a wire rode, forming a preliminary filament, treating the preliminary filament by a patenting process, brass plating, and drawing a plurality of times.

At this time, the wire rod is preferably carbon steel having a carbon content of 0.7% to 2% and having a diameter of 5.5 mm, which is a common standard.

3, the filament 10a is introduced between the spiral adiabatic part 20 including the corrugated part 21 and the corrugated part 22 to form the filament 10a with the waveform 110a ) To form the single-wire steel cord of the present invention.

A region corresponding to the waveform forming portion 21 is referred to as a waveform region 110 and a region corresponding to the waveform forming portion 22 is referred to as a non-waveform region 120. [

It is preferable to use a sintered alloy (WC) as the spiral loader 20, and the waveform forming part 21 can be adjusted according to a desired waveform.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples are for illustrative purposes only and are not intended to limit the present invention.

1) Example 1

The wire rod having a carbon content of 0.82% and a diameter of 5.5 mm was first freshly washed and then brass plated to a diameter of 1.90 mm, and filaments were prepared by final drawing to a diameter of 0.40 mm. Thereafter, a waveform was applied so that the waveform section was 10 mm and the non-waveform section was 10 mm using a partial screw type machine. Table 1 shows the results of evaluating the properties after manufacturing a single wire steel cord having a break elongation of 3.5% by adjusting the height of the corrugation in the corrugated area to 0.80 mm.

2) Comparative Example 1

The wire rod having a carbon content of 0.82% and a diameter of 5.5 mm was subjected to a first fresh pouring treatment and brass plating so as to have a diameter of 1.90 mm and a filament was prepared by final drawing to a diameter of 0.40 mm. Then, using a partial screw-type machine, a waveform was given so that the waveform section was 10 mm and the non-waveform section was 10 mm. By adjusting the height of the waveform of the waveform section to 0.48 mm, a single wire steel cord with a break elongation of 2.2% The results are shown in Table 1 below.

3) Comparative Example 2

The wire rod having a carbon content of 0.82% and a diameter of 5.5 mm was subjected to a first fresh pouring treatment and brass plating so as to have a diameter of 1.90 mm and a filament was prepared by final drawing to a diameter of 0.40 mm. After that, a single wire (Mono Wire) was produced flat using a pressing roller, and the properties after the steel cord was manufactured by using a straight line calibration R / O are shown in Table 1 below.

Sample classification Example 1 Comparative Example 1 Comparative Example 2 filament Short diameter (mm) 0.40 0.40 0.36 Long diameter (mm) 0.80 0.48 0.45 Length of the corrugated area (mm) 10 10 - The length (mm) of the non- 10 10 - Pitch (mm) 20 20 20 Rotation (times / 6m) ± 0 ± 0 ± 0 Linearity (AH) (mm / 40cm) 10 10 40 Elongation (%) 3.5 2.2 0.8 Adhesion (kg / 8 mm) 28 22 17

Referring to Table 1, when comparing Example 1 with Comparative Example 1 and Comparative Example 2, it can be seen that the adhesion with the tire is improved because the elongation is increased. Also, although not shown in Table 1, the steel cord of Example 1 has a high elongation, so that the belt edge separation phenomenon is improved even in the case where the bending of the road surface is weak, and durability is improved.

In the case of Comparative Example 2, the linearity is reduced due to the use of the compressed R / O, and the workability in rubber topping operation and topping sheet cutting operation is lowered during tire production.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a view showing a single wire steel cord according to the present invention; FIG.

2 and 3 are views showing a method of manufacturing a single wire steel cord according to the present invention.

Claims

A waveform region and a non-waveform region each having an elongation of 3.5 to 5% and including one or a plurality of waveforms,

Characterized in that the wire diameter is 0.10 mm to 1.0 mm, the carbon content is 0.7 to 2%, and the tensile strength is 270 to 480 kg / mm ² .

Wherein the waveform region and the non-waveform region are repeated at a length ratio of 1: 9 to 9: 1,

Wherein the corrugated area comprises 1 to 100 corrugations, the corrugations having a height of 0.30 mm to 3.0 mm, a length of 1 mm to 10 mm and a corrugation ratio of 150 to 300% :

※ Shape ratio (%) = h (height of waveform) / d (diameter) × 100.

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