KR101639870B1 - Apparatus and Method for manufacturing steel wire - Google Patents

Abstract

The steel wire manufacturing apparatus according to the present invention includes moving means for moving a workpiece; And a drawing means configured to draw a shape and to draw the material in the longitudinal direction in both directions.
As described above, according to the present invention, since the drawing means is constituted such that the drawing is performed in both directions with respect to the longitudinal direction of the workpiece, the cumulative strain is increased even at the same reduction rate at the time of drawing the workpiece, It is possible to improve the twisting characteristic of the steel wire.

Description

TECHNICAL FIELD [0001] The present invention relates to a steel wire manufacturing apparatus,

The present invention relates to a manufacturing apparatus and a manufacturing method for a steel wire, which is capable of increasing the cumulative strain even at the same reduction rate in drawing a workpiece and reducing strain variation in the inside and the surface of the workpiece in order to improve the twist characteristic of the steel wire, .

The torsional properties of high carbon steel wires are used as indicators of ductility as important material properties in various steel types such as tirecord, bridge cable, and bead wire.

In order to increase the strength of the wire rod, when a large amount of reduction amount is given through cold drawing, generally ductility, that is, torsional characteristic is deteriorated, so that delamination (a phenomenon in which the steel wire is broken in a spiral shape when twisting) occurs.

Also, in the case of high carbon steel wire, a plurality of strands are twisted and stranded to form a bundle. When the ductility is poor, the bundle characteristics are deteriorated.

On the other hand, the cause of the delamination is variously analyzed, but the cause of the delamination has not been found yet. There are various theories explaining the causes of delamination.

One of them explains that the creation of texture is made non-uniform due to the deviation of the external strain in the material, and the crack starts at the uneven interface at the torsional deformation. In this connection, it has been reported that the ductility of a high-carbon steel wire can be improved by applying a non-circular drawing (Application No. 10-2011-0070135).

As described above, in the process of manufacturing a high carbon steel wire, there has been actively conducted research to improve the torsional characteristics in order to suppress the occurrence of delamination in the process of using the manufactured high carbon steel wire.

Disclosure of the Invention The present invention has been devised to solve the above problems and it is an object of the present invention to provide a steel wire manufacturing method capable of increasing the cumulative strain even at the same reduction rate, And a method for manufacturing the same.

In order to accomplish the above object, according to a preferred embodiment of the present invention, there is provided a steel wire manufacturing apparatus comprising moving means for moving a workpiece; And a drawing means configured to draw a shape and to draw the material in the longitudinal direction in both directions.

Here, the drawing means may be constituted such that both of the two-sided drawing with respect to the longitudinal direction of the workpiece are formed in the non-circular drawing and the circular drawing drawing.

Specifically, the drawing means includes a drawing portion having a non-circular drawing die for drawing a material into a non-circular shape and a circular drawing die for drawing a material into a circular shape; A control unit for driving and controlling the moving means so that drawing in the longitudinal direction of the work is performed in both directions; And an order holding unit configured to be operated in both the non-circular drawing mode and the circular drawing order, both of which are bidirectional with respect to the longitudinal direction of the workpiece, and are driven and controlled by the control unit.

The order maintaining unit may include a replacement driving member for switching the sequence of the non-circular drawing die and the circular drawing die when the work is moved in the reverse direction.

The order maintaining unit may include a position changing member for changing the position of the moving unit so that the non-circular drawing die and the circular drawing die provided separately are provided when the material is moved in the reverse direction.

Furthermore, the drawing means may be provided with a plurality of the drawing portions in the forward or backward movement line of the work.

According to another aspect of the present invention, there is provided a method of forming a metal sheet, the method comprising: And a reverse drawing step in which the drawing is performed in the opposite direction to the longitudinal direction of the workpiece.

Here, each of the forward drawing step and the reverse drawing drawing step may include a non-circular drawing step in which the material is drawn into a non-circular shape; And a circular drawing process in which the material is circularly drawn after the non-circular drawing process.

At this time, each of the forward drawing step and the reverse drawing drawing step may be carried out a plurality of times by the integrated drawing drawing which sets the non-circular drawing process and the circular drawing process as one set.

The steel wire manufacturing apparatus and the manufacturing method according to the present invention are characterized in that the drawing means is constituted such that drawing is performed in both directions with respect to the longitudinal direction of the workpiece so that cumulative strain is increased even at the same reduction rate, By reducing the deviation of strain between the inside and the surface layer, it is possible to improve the torsional characteristics of the steel wire.

Fig. 1 is a view showing the cross-sectional area of the workpiece by the die drawing and the circular drawing.
Fig. 2 is a view showing the cross-sectional area of the material by one-directional drawing and two-sided drawing.
3 is a view illustrating a steel wire manufacturing apparatus according to an embodiment of the present invention.
Fig. 4 is a view showing that the drawing portion is rotated by the replacement driving member in the steel wire manufacturing apparatus of Fig. 3;
Fig. 5 is a view showing that the moving means is changed in position by the position changing member in the steel wire manufacturing apparatus of Fig. 3;
6 is a flowchart showing a method of manufacturing a steel wire according to an embodiment of the present invention.
Fig. 7 is a flowchart showing mold release drawing in the steel wire manufacturing method of Fig. 6;
8 is a graph showing a strain variation of a work according to a drawing method of a work.
9 is a table showing the tensile strength, the section reduction rate, and the torsional rotation speed up to the material break according to the drawing method of the work.
Fig. 10 is a view comparing the torsional fracture surfaces of the blank according to the drawing method of the blank.

In order to improve the twist characteristic of the steel wire, the steel wire manufacturing apparatus and the manufacturing method of the present invention are characterized in that, in order to increase the cumulative strain even at the same reduction rate at the time of drawing the material, And a drawing means for drawing the drawing in the longitudinal direction of the drawing in both directions is constituted.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are displayed on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Fig. 1 is a view showing the cross-sectional area of a workpiece by the die-drawing and circular drawing, and Fig. 2 is a view showing the cross-sectional area of the workpiece by one-

FIG. 3 is a view showing a steel wire manufacturing apparatus according to an embodiment of the present invention, FIG. 4 is a view showing that the drawing portion is rotated by the replacement drive member in the steel wire manufacturing apparatus of FIG. 3, In which the moving means is displaced by the position changing member in the steel wire manufacturing apparatus of Fig.

The present invention includes a moving means (100) for moving a workpiece, and a drawing means for drawing the workpiece (1) so that drawing is performed in both directions in the longitudinal direction of the workpiece (1).

Here, the moving means 100 can be any member that is configured to move the work 1, and as shown in the figure, a reel that can be wound and unwound can be utilized as an example.

Further, the drawing means may be configured to release the work 1 from the mold.

At this time, the mold releasing by the drawing means will be described below with reference to Fig. 1, in comparison with the circular drawing.

A general circular drawing is a drawing method in which a wire material is reduced to a circular shape at the time of drawing. The sectional area of the drawing material is reduced by drawing the wire material, and the cross section of the drawing die of the drawing die has a circular shape, so that the sectional area of the drawn wire material becomes circular.

On the contrary, the mold releasing according to the present invention is a drawing method for reducing the shape of the cross sectional area of the wire when the wire is drawn, by reducing the cross-sectional area of the wire by drawing the wire, In the process of passing the fresh die, the cross-sectional area of the drawn wire is different for each pass. For example, the shape drawing can be made of a non-circular drawing, a circular drawing, a non-circular drawing, and a circular drawing as shown in FIG.

Here, the above-described mold release is characterized in that the cross-sectional shape of the wire rod changes when the wire rod is drawn, and the cumulative strain can be greatly increased at the same reduction surface, and at the same time, the inner strain variation can be reduced with the surface of the material (1).

As a result, the mold releasing by the drawing means of the present invention can increase the ductility of the material (1) and improve the delamination resistance compared with the circular drawing. In addition, there is an advantage that a more uniform strain can be obtained as compared with the circular drawing by changing the rotation direction of the intermediate section.

In addition, the drawing means of the present invention can be configured so as to perform die-free drawing, but drawing in the longitudinal direction of the work 1 is performed in both directions.

That is, in order to obtain a more uniform deformation of the work 1 than to perform only the release work, the present invention is characterized by changing the direction of drawing in the longitudinal direction of the work 1, The strain variation occurring between the surface layer (surface) can be reduced.

Here, the bi-directional drawing by the drawing means will be described in comparison with the one-direction drawing at the micro-element side of FIG. 2 as follows.

When the non-circular drawing is performed through unidirectional drawing, the material 1 is deformed continuously. However, when the unidirectional drawing is performed through bidirectional drawing, the drawing direction is changed after the small element is deformed by shear deformation, .

Particularly, the bidirectional drawing has the same amount of unidirectional drawing and the amount of reduction, but the strain is restored due to the shearing deformation at the surface of the material (1), and the strain deviation between the center of the material (1) and the surface layer is reduced.

As a result, the mold releasing by the drawing means of the present invention can increase the ductility of the material (1) and improve the delamination resistance compared with the circular drawing. In addition, there is an advantage that a more uniform strain can be obtained as compared with the circular drawing by changing the rotation direction of the intermediate section.

As described above, according to the present invention, for this purpose, the drawing means can be constituted so as to be able to carry out die drawing in both the non-circular drawing and the circular drawing in the longitudinal direction of the work 1.

Specifically, the drawing means includes a non-circular drawing die 210 for drawing the material 1 into a non-circular shape, and a drawing portion having a circular drawing die 220 for drawing the material 1 in a circular shape. And a control unit for driving and controlling the moving means 100 so as to move the work 1 in the normal direction and the reverse direction so that drawing along the longitudinal direction of the work 1 is performed in both directions.

The drawing means may include a sequence holding portion that is driven and controlled by the control portion so that the drawing in both directions with respect to the longitudinal direction of the work 1 is performed in the order of non-circular drawing and circular drawing.

3 (a), the raw material is passed through the non-circular drawing die 210 and the circular drawing die 220 while moving the work 1 in the forward direction by the moving means 100 The raw material 1 is moved in the reverse direction by the moving means 100 as shown in Fig. 3 (b), and is passed through the non-circular drawing die 210 and the circular drawing die 220 to be fresh . Further, the present invention is characterized in that a plurality of the above-described drawing portions, which are a set of the non-circular drawing die 210 and the circular drawing die 220, are arranged in the forward or backward movement line of the material, May be deformed and drawn a plurality of times.

At this time, the backward movement of the work 1 is not performed by moving the forward end of the work 1 in the forward direction to move the work 1 in the reverse direction, In the opposite direction so that the distal end portion is the rear end of the movement without turning on the distal end of the distal end portion.

The order maintaining unit is configured such that both the bidirectional drawing with respect to the longitudinal direction of the work 1 are performed in the order of non-circular drawing and circular drawing. In the alternative driving member 310 as shown in FIG. 4 or FIG. 5 A position changing member 320 as shown can be utilized.

Specifically, the replacement drive member 310 is configured to switch the order of the non-circular drawing die 210 and the circular drawing die 220 when the work 1 is moved in the reverse direction. At this time, the replacement drive member 310 may include a rotation plate on which the drawing portion is seated, and a rotation motor for rotating the rotation plate, though not shown in the drawing.

The position changing member 320 moves the moving means 100 in a direction opposite to the moving direction of the work 1 so as to pass the other non-circular drawing die 210 'and the circular drawing die 220' And a position changing member 320 for changing the position of the movable member. In this case, the position changing member 320 may include a moving plate on which a rail is formed on an upper portion, for example, although not shown in the drawing, and a moving block on which the moving unit 100 is coupled and moved along the rail have.

A method of manufacturing a steel wire according to the present invention will be briefly described with reference to FIGS. 6 and 7. FIG.

FIG. 6 is a flowchart showing a method of manufacturing a steel wire according to an embodiment of the present invention, and FIG. 7 is a flowchart showing mold release in the steel wire manufacturing method of FIG.

Referring to the drawings, the present invention includes a forward drawing step in which the drawing is performed in the forward direction with respect to the longitudinal direction of the workpiece, and a reverse drawing step in which the drawing is performed in the reverse direction with respect to the length direction of the workpiece.

In this case, each of the forward drawing step and the reverse drawing step may include a non-circular drawing step in which the material is drawn into a non-circular shape; And a circular drawing process in which the material is circularly drawn after the non-circular drawing process.

Further, each of the forward drafting step and the reverse drafting step may be configured to perform the integrated drafting process in which the non-circular drafting process and the circular drafting process are set as one set a plurality of times.

FIG. 9 is a table showing the tensile strength, the section reduction ratio, and the torsional rotation speed up to the material breakage according to the drawing method of the material. FIG. Fig. 8 is a view comparing the torsional fracture surfaces of the material according to the fresh method.

The present invention applies a differential drawing to a workpiece and changes the drawing direction in the subsequent drawing process, so that the strain magnitude is the same but the strain deviation can be reduced.

As shown in FIG. 8, it can be seen that the bi-directional deformation drawing of the present invention can reduce the strain variation between the surface layer and the inside of the workpiece compared to the circular drawing and the unidirectional deformation drawing.

As an example, the present invention was applied to 0.8% C high carbon steel having an initial wire rod diameter of 13 mm, and the tensile strength and the section reduction ratio of the material (1) processed by circular drawing, unidirectional deformation drawing, Reduction of Area, RA) and torsional characteristics.

A total of 10 passes were drawn with a reduction of 20% per pass, and the diameter of the final wire rod was 4.26 mm. In this case, as shown in FIG. 9, the cross-sectional reduction ratio and the torsional rotational speed until the fracture were the largest in the case of the bi-directional deformation drawing in the final steel wire.

10 (a), the delamination occurred in the material. In the case of the bidirectional deformation drawing of FIG. 10 (c), the fracture surface of the material is smooth than the unidirectional deformation drawing of FIG. 10 It can be seen that it is close to the fracture.

According to the present invention configured as described above, since the drawing means is constituted such that drawing is performed in both directions with respect to the longitudinal direction of the work (1), the cumulative strain is increased And by reducing the strain fluctuation of the inside and the surface layer of the material 1, the twisting characteristic of the steel wire can be improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is to be understood that various changes and modifications may be made without departing from the scope of the appended claims.

1: Material 100: Moving means
210: Non-circular drawing die 220: Circular drawing die
310: replacement drive member 320: position change member

Claims (9)

Moving means for moving the material; And
And a drawing means configured to draw the shape of the workpiece so that drawing is performed in both directions with respect to the longitudinal direction of the workpiece,
The drawing means
A fresh portion having a non-circular draw die for drawing a material into a non-circular shape and a circular drawing die for drawing a material into a circle; And
And a replacement driving member for switching the sequence of the non-circular drawing die and the circular drawing die when the work is moved in the reverse direction;
And a plurality of wire ropes.
The method according to claim 1,
The drawing means
Wherein both the bidirectional drawing with respect to the longitudinal direction of the workpiece are formed so as to form a freeform drawing in the order of non-circular drawing and circular drawing.
3. The method of claim 2,
The drawing means
And a control unit for drivingly controlling the moving unit so that drawing in the longitudinal direction of the work is performed in both directions,
Wherein the controller controls driving of the order holding unit such that bidirectional drawing with respect to the longitudinal direction of the work is performed in the order of non-circular drawing and circular drawing.
delete The method of claim 3,
Wherein the order holding unit comprises:
A position changing member for changing the position of the moving means so as to pass the other non-circular drawing die and the circular drawing die provided separately in the reverse movement of the material;
And a plurality of wire rope assemblies.
The method according to claim 3 or 5,
The drawing means
Wherein a plurality of the drawing portions are arranged in a forward or backward movement line of the work.
A non-circular drawing die in which the work is moved in the normal direction with respect to the longitudinal direction by the moving means, and a circular drawing die in which the work is drawn into a circular shape, step; And
Wherein the material is moved in the opposite direction to the longitudinal direction by the moving means, the drawing is made in the reverse direction by the drawing portion, and the order of the non-circular drawing die and the circular drawing die is switched by the replacement driving member, A reverse drawing step in which the mold drawing is performed in the same order as the drawing step;
And the steel wire is manufactured.
8. The method of claim 7,
Wherein each of the forward drafting step and the reverse drafting step comprises:
A non-circular drawing process in which the material is drawn into a non-circular shape; And
A circular drawing process in which the material is circularly drawn after the non-circular drawing process;
And a mold releasing process is performed.
9. The method of claim 8,
Wherein each of the forward drafting step and the reverse drafting step comprises:
Wherein an integrated drawing process in which the non-circular drawing process and the circular drawing process are one set is performed a plurality of times.

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