KR20010028426A - Dies nib for steel cords - Google Patents

Abstract

PURPOSE: A dies nib is provided to reduce the damage of the dies nib and a steel cord surface by preventing excessive force to the dies and a steel cord, to uniformly wear the dies nib and to improve the linear property of the steel cord by locating a bearing in the center of a dies. CONSTITUTION: A dies nib for steel cord contains a bell to easily input a lubricant; an approach to generate a friction with a steel cord and to reduce a sectional area; a bearing to uniformly wear the dies nib and to improve the linear property of the steel cord by locating in the center of the dies nib; a back approach to reduce the damage of the dies nib and the surface damage of the steel cord by preventing excessive force into a dies and the steel cord; and a back bell to prevent the damage of the dies and the scratch of the steel cord. The angle of the back approach is 8-12degrees.

Description

Dies nip for steel cords {DIES NIB FOR STEEL CORDS}

The present invention relates to a die nip for steel cords used in the drawing process during the manufacturing of steel cords for reinforcing rubber products, and more particularly, a back tension taken in the process of drawing steel wires through a die. The present invention relates to a die nip for steel cords, which prevents breakage of die nips, prevents occurrence of gas in the wire, and is applicable to dry and wet wires in steel cord manufacturing processes.

As is well known, steel cord is composed mostly of steel, and other strength elements such as nylon and aramid may exist as filling elements in the cord, and carbon content is 0.6 to Wire wires of 5.0 to 5.5 mm in diameter made of 0.95% by weight carbon steel are wired to wires of 0.9 to 1.8 mm in diameter to obtain the properties required for other steel cords such as microstructure, tensile strength, toughness, etc., suitable for final wire drawing. After heating to 950 ~ 1000 ℃ to perform a potting heat treatment that is maintained at 500 ~ 550 ℃ for several seconds, 0.5 ~ 1.5 ㎛ thick copper plating and 0.3 ~ 1.0 ㎛ zinc plating sequentially thereon after various After the thermal diffusion process of the method to obtain a brass plated layer and the final drawing process with a diameter of 0.1 ~ 0.6 mm and the metal filament in various structures depending on the application, for example, 1 × 2, 1 × 3, 1 × 4, 2 +2, 3 + 6, 3 + 9 Twisted with +15, it is mainly used for rubber reinforcement such as tire, conveyor belt, polyurethane, rubber timing belt and hose because it has superior strength, modulus, heat resistance and fatigue resistance compared to other types of inorganic and organic fibers. have.

In the drawing process performed to obtain a desired diameter in the steel cord manufacturing process, the steel wire is drawn through the die as shown in FIG. The shape of the dice is determined and used in the most suitable form depending on the material, the wire diameter, etc. of the wire to be drawn. In addition, various die nips are used depending on the application, but generally used in steel cord manufacturing processes are alloy die nips and diamond die nips obtained by sintering tungsten carbide powder at high temperature. As shown in Figure 1, the die consists of a nib (1) through which the actual steel wire passes and a case (2) surrounding the nip, and the structure of the die nip is divided into four parts. Easy-to-use bell, Approach to reduce the cross-sectional area by friction with actual steel wire, Bearing to determine the actual wire diameter, Bearing strength of the die due to tensile force when drawing and prevention of fresh wire It consists of a Back Relief. The general shape of the die nip currently used is about 8 to 12 degrees of approach angle, the bearing length is about 0.1 to 0.4 d of the diameter d mm Φ, and the angle of the back relief is about 90 to 120 degrees. It is used by setting the optimum conditions according to the wire diameter.

In general, the speed of drawing steel wire of high carbon steel with carbon content of 0.6 to 0.95% by weight is generally high speed of 600 to 1200 m / min. When drawing, the steel wire passes through the die and high heat is generated. There is a problem that the excessive draw force is often taken so that the die nip is frequently broken.

In addition, the steel wire through which the die passes in the wire is compressed, and the surface of the steel wire has the tensile residual stress as much as the elastic limit due to the repulsive force against compression, so the wire diameter (d1) of the steel wire passed through the actual die is the diameter of the die (diameter). It becomes 1 / 1,000-3 / 1,000 mm larger than (d). After passing through the die, the back tension (7) is applied to the steel wire having a diameter of d1 of 1 / 1,000 to 3 / 1,000 mm and acts in the opposite direction of the fresh direction or the tension direction (8), as shown in FIG. In many cases, damage to the back relief of the die nip and fresh steel wire may be caused by gas or the like. In order to prevent the damage of the die nip and the damage of the steel wire due to the force of the tension force, as shown in Figure 2, the back relief is sometimes used to produce a double 30 degrees or 90 degrees, but it is not a fundamental solution.

Accordingly, an object of the present invention is to solve the conventional problems as described above, in order to prevent the damage of the die nip and the damage of the steel wire due to the torsion force, the back relief shape is made as an approach-like form, the overall shape of the die nip is symmetric As a result, the steel wire passing through the die during drawing is prevented from being excessively applied to the die and the steel wire even though the force is applied in the state in which the steel wire passed through the die is larger than the actual wire diameter due to the tensile residual stress, thereby reducing the breakage of the die nip and the wire surface damage, The bearing part can be placed in the center of the die to maintain the center of gravity of the die when drawing, providing a die cord nip for the steel cord that evenly wears the die nip and the straightness of the fresh wire is good.

In order to achieve the above object, the die nip for steel cord of the present invention is a die nip for steel cord production.

A bell that facilitates the introduction of lubricant; An approach that causes friction with the actual steel wire and reduces the cross-sectional area; A bearing which determines the actual wire diameter and is positioned at the center of the die to maintain the center of gravity of the die, thereby improving uniform wear of the die nip and the linearity of the drawn steel wire; It has the same shape as the approach and symmetrical, thereby preventing the excessive force applied to the die and steel wire even if the steel wire passing through the die when drawn is greater than the actual wire diameter due to the tensile residual stress. A bag approach to reduce breakage and wire surface damage; The bell-like shape has a symmetrical shape, and the back bell to prevent breakage of the die due to the tensile force when drawn, characterized in that it comprises a back bell to prevent the wire of fresh steel wire.

1 is a cross-sectional view of a model showing the general configuration of the die nip for steel cord production,

2 is a cross-sectional view of a model showing a general configuration of a die nip employing a conventional double bag,

3 is a cross-sectional view of a model showing the die nip configuration for a steel cord according to an embodiment of the present invention,

It is a schematic diagram which shows the tension applied to the steel wire at the time of die | dye passage.

<Description of the code | symbol about the principal part of drawing>

1: Die nip 2: Die case (Case)

d: Diameter of die d1: Diameter of steel wire passing through die

7: Back Tention 8: Forward Tension

Hereinafter, a die snip for a steel cord according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a cross-sectional view of a model showing a die cord nip configuration for a steel cord according to an embodiment of the present invention, wherein the die cord nip for a steel cord according to an embodiment of the present invention includes a bell, an approach, a bearing, a backprop and a backbell. It is.

The bell serves to facilitate the introduction of lubricant.

In addition, the Approach causes friction with the actual steel wire and serves to reduce the cross-sectional area.

On the other hand, the bearing (Bearing) determines the actual wire diameter and can be located in the center of the die to maintain the center of gravity of the die to play a role of improving the uniform wear of the die nip and the straightness of the fresh steel wire.

In addition, the back proch has a symmetrical shape similar to the approach, whereby an excessive force is applied to the die and the steel wire even if the steel wire passing through the die is stretched in a state where it is stretched over the actual wire diameter by the tensile residual stress. To prevent breakage of the die nip and damage to the steel wire surface.

On the other hand, the backbell has a symmetrical shape, such as the bell, and serves to prevent the breakage of the die due to the tensile force when the wire is drawn, such as the back proch and to prevent the gas of the fresh steel wire.

In addition, when the back approach angle of the steel cord die nip is 8 to 12 degrees, it is possible to perform a role of reducing the damage of the die nip and the steel wire surface even more.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by the following Examples.

Example

It is a symmetrical die made with a Φ9 × H7mm approach angle of 12 degrees, and a brass-plated steel wire with a carbon content of 0.82% and a diameter of 1.42mm is drawn to a diameter of 0.25mm, which is produced after 90 days of drawing at a rate of 840 m / min. The incidence rate of the steel wire and the use dies were collected and the failure rate was summarized in Table 1 below.

Comparative example

Except for using the general dice produced by the back relief angle 90 degrees, after performing in the same manner as in Example 1, the incidence rate of the steel wire and the breakage rate at the time of collection of the used dies are shown in Table 1 below.

division Example Comparative example Production Ton 370 372 Steel wire occurrences (times) 11 45 The number of dice use () 4140 4240 Collection dice damaged () 12 105 Occurrence rate (times / ton) 0.030 0.121 Die breakage rate (%) 0.29 2.48

* Breakdown rate = (damage quantity / usage quantity) × 100 (%)

The present invention is not limited to the die nip for steel cords, but can also be applied to a die nip for drawing general mild steel wire and hard steel wire.

As described above, according to the die nip for steel cords according to the present invention, even when the steel wire passing through the die is stretched over the actual wire diameter due to the tensile residual stress, it is prevented from applying excessive force to the die and the steel wire. Therefore, it is possible to reduce the damage of die nip and the surface of steel wire, and to maintain the center of gravity of the die when drawing, so that the uniform wear of die nip and the straightness of wire drawn are also excellent.

Claims (2)

In the die nip for steel cord production, A bell that facilitates the introduction of lubricant; An approach that causes friction with the actual steel wire and reduces the cross-sectional area; A bearing which determines the actual wire diameter and is positioned at the center of the die to maintain the center of gravity of the die, thereby improving uniform wear of the die nip and the linearity of the drawn steel wire; It has the same shape as the approach and symmetrical, thereby preventing the excessive force applied to the die and steel wire even if the steel wire passing through the die when drawn is greater than the actual wire diameter due to the tensile residual stress. A back proch to reduce breakage and damage to steel surface; The die cord nip of the steel cord, having a symmetrical shape such as the bell, and having a back bell, such as the back proch, to prevent breakage of the die due to tensile force during drawing and to prevent the wire from being drawn. The method of claim 1, The die cord nip for steel cord, characterized in that the angle of the back proch of the die nip for the steel cord is 8 to 12 degrees.