JPH0775731B2 - Wire drawing method and apparatus using three rolls - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for wire drawing by rolling from three directions by rolls in the processing of steel wire such as bar steel.

[0002]

2. Description of the Related Art Conventionally, a steel wire such as a bar steel is passed through a forming hole formed between two rolls or three rolls,
As a wire drawing method for rolling and wire drawing, several rolling units consisting of a forcibly driven roll assembly are arranged, and a system for performing draw wire drawing continuously by driving the roll assembly of the rolling unit, non-driving A method is known in which a rolling unit composed of a roll assembly is combined with a capstan, and a drawing wire is drawn by pulling out a steel wire with the capstan (for example, JP-B-46-10652 and JP-A-63-63). 10
4716).

[0003]

In any of the above-described conventional drawing lines, particularly when a three-roll rolling unit is used, the steel wire is caught in the gap between the rolls and burrs are generated. There are drawbacks such as being easy and the shape does not appear well, and the wear of the roll is fast and the damage frequency of the roll is high. Furthermore, the wire diameter cannot be adjusted by the conventional rolling method. The present invention was devised in order to eliminate the drawbacks of the above-described conventional drawing line working technology, and enables breakage of a roll during drawing line and extension of roll life, and a wire rod after drawing line. An object of the present invention is to provide a drawing line method and apparatus capable of stabilizing the shape of the above and easily adjusting linearly.

[0004]

According to the present invention, there are provided three objects.
In a wire drawing method in which a plurality of rolling units each having a three-roll assembly are arranged in series so as to roll a wire from one side and cold drawing is performed, the rolling units are not driven or move.
Motor driven triangle hole type 3 roll assembly
From combination with a three-roll assembly of a round hole type driven by
The breaking load is 20 to 40 when entering the rolling unit.
The problem could be solved by adopting the technical means characterized by applying a reverse tension of% . If the reverse tension is 15% or less of the breaking load of the incoming wire, the line is too weak to protrude from the gap between the rolls, and if it is 45% or more, the line is too strong to be in a stretched state. 20% to 4
A range of 0% is suitable.

Further, a wire drawing apparatus for achieving the above wire drawing method is a rolling unit having a three-roll assembly composed of three rolls arranged at an angle of 120 °, and is arranged upstream of the rolling unit. A plurality of reverse tension applying dancer rollers and a capstan arranged on the downstream side of the rolling unit are arranged. The rolling unit is configured with a combination of a non-driving or motor-driven three-roll assembly having a forming hole of a triangle hole and a round-roll type motor-driving three-roll assembly for better wire drawing. You can

[0006]

In the rolling of the wire drawing apparatus for the type 3 roll having the above-described structure, various experiments were conducted on the influence of the reverse tension, and the following was found. By applying reverse tension to the wire being rolled by the wire drawing addition dancer roller, the wire can be prevented from tipping over in the round-hole type 3 roll, the wire is prevented from being caught in the roll gap, and the shape of the wire is stabilized. . In addition, the reduced cross-sectional shape changed depending on the magnitude of the reverse tension applied, and by selecting the optimum magnitude of the reverse tension, it was possible to stably draw a good cross-sectional shape. In order to obtain the best cross-sectional shape, the range of 21% to 35% was desired in the case of the stainless steel wire of the example described later,
The range is expected to change depending on the type of wire.

By changing the reverse tension, the cross-sectional shape of the wire changes and the wire diameter also changes. Therefore, the wire diameter can be adjusted by adjusting the reverse tension applied. Furthermore, it was confirmed that the rolling reaction force on the rolls was reduced by applying the reverse tension as compared with the conventional system, and it is possible to prevent damage to the rolls and improve the life. As a result, the occurrence of surface flaws on the wire after the drawing line is prevented, and the productivity is improved.

[0008]

1 is a schematic view of an embodiment of a rolling apparatus according to the present invention. The example in the figure shows a 3-roll wire drawing device consisting of 5 stands. In the figure, 1 is the first wire drawing stand,
2 is a second wire drawing stand, 3 is a third wire drawing stand, 4 is a fourth wire drawing stand, and 5 is a fifth wire drawing stand. In each wire drawing stand, a rolling unit 9 in which one set of non-driving or motor-driven three-roll assembly 7 having a forming hole of a triangle hole and one set of three-roll assembly 8 of a round-hole type motor-driven are respectively installed. After that, a capstan 10 for winding the wire and a dancer roller 11 for applying reverse tension to the next wire drawing stand are installed. The dancer roller 11 is vertically driven by an air cylinder (not shown) so that the reverse tension applied to the wire can be adjusted.

Each roll of each of the three roll assemblies 7 and 8 is made of cemented carbide, and the details of the three roll assembly 8 are shown in FIG. Each 3-roll assembly 8 has 120
Three rolls are arranged at an interval of °, and a forming hole 13 is formed at the top of the peripheral edge. The shaft 14 to which the main driving roll 15 is attached is driven by a DC motor, and the two driven rolls 16 and 17 are driven via bevel gears 18, 19, 20, and 21. The structure of the three-hole assembly 7 of the triangle hole type is the same structure except that the shape of the roll is different.

With the above apparatus, the material is SUS
304-W1 (JISG4309) diameter 2.30m
When drawing lines with m and 2.70 mm of original wire with the reduction of area as shown in Table 1 and Table 2, respectively, the linear velocity is up to 300 mm / min and the reverse tension is the breaking load of the incoming wire. The effect of reverse tension was tested by varying the range of 10% to 50% of the pressure applied. In the wire drawing shown in Table 1, the total area reduction rate was 69.5% and the average area reduction rate was 11.2%. In the wire drawing process shown in Table 2, the total area reduction rate was 76.5%. The average area reduction rate is 13.6%. The area reduction rate is calculated by the theoretical calculation area when the width expansion rate is zero. Further, in the table, ∇ indicates a triangle roll type three-roll assembly, and ◯ indicates a round hole type three-roll assembly.

[Table 1]

[Table 2]

In the wire drawing process shown in Table 1, a linear velocity of 100 m / mi
n is the reverse tension, 10%, 30%, and 5 of the breaking load of the incoming wire
FIG. 3 shows the cross-sectional shape of the wire in each stand when 0% is added and wire drawing is performed. In FIG.
(A) shows a case where the reverse tension is 10%, (b) shows a case of 30%, and (c) shows a case of 50%. In each figure, T _{1 to} T ₅ are the cross-sectional shapes of outgoing lines from the triangle hole type three-roll assemblies in the first to fifth stands, and R _{1 to} R ₅ are the rounds in the first to fifth stands. The outgoing line cross-sectional shape from the hole-type three-roll assembly is shown. As is clear from the figure, when the cross-sectional shape of the wire changes depending on the magnitude of the reverse tension to be applied and a reverse tension of 30% of the breaking load of the incoming wire is applied, the wire fits neatly within the hole diameter of the roll. The cross-sectional shape is the best. When the reverse tension is 10%, the reverse tension is weak and the line protrudes from the gap between the rolls. Conversely, when the reverse tension is 50%, the line is too strong, the line is in a fine state of drawing, and a flat portion is formed on the round line. Therefore, in this example, it is understood that the application of 30% reverse tension is almost optimal.

In the wire drawing process shown in Table 2, the wire speed is 3
Reverse tension at 00m / min is 21% to 30% of breaking load of incoming wire
As a result of adding and drawing wire, the difference in diameter deviation between the round hole type 3 roll assembly lead wires of each stand is 0.06 to 0.02 mm.
(5th stand outgoing wire), and could be drawn into an extremely good cross-sectional shape. FIG. 4 shows a cross-sectional shape of a lead wire in each stand. A cross-sectional shape T _{1 of a} lead wire of a three-roll assembly having a triangle hole type in the upper stage and a round hole type in the lower stage
Shows a T ₅ and R ₁ to R _5.

On the other hand, as a result of investigating the influence of the reverse tension in the wire drawing in Table 1 on the wire diameter, the results shown in the graph of FIG. 5 were obtained. This figure shows the change in the wire diameter converted into a round wire by measuring the cross-sectional area of the fifth stand outgoing wire.
As is clear from the figure, the wire diameter decreases as the reverse tension increases, and it can be understood that the wire diameter can be adjusted by controlling the magnitude of the reverse tension applied. In the present embodiment, the wire diameter when 10% reverse tension of the breaking load of the incoming wire is applied is d ₀
Then, the wire diameter d ₁ of the fifth stand is d ₁ = d ₀ -1.02
The regression equation is 5 × 10 ⁻³ × (x−10). When the wire drawing process is performed with a wire rod type and a surface reduction ratio other than those shown in Table 1, this regression equation is not always applicable.

Further, by applying the reverse tension, the contact projected area of the roll is reduced, and the rolling reaction force on the roll is accordingly reduced. The graph of FIG. 6 shows the contact projected area of each stand when the reverse tension is 10%, 30%, and 50% in the wire drawing process of Table 1, and thereby the rolling reaction force per roll is measured. It is a graph of the calculated results. The graph clearly shows that the rolling reaction force changes with the degree of reverse tension. In this way, the reverse tension reduces the rolling reaction force on the roll, and as a result, it has a positive effect on extending the roll life. Although the embodiment of the present invention using the stainless steel wire has been described above, it goes without saying that the present invention is not limited to the stainless steel wire and can be applied to other steel wires. Further, the number of rolling stands is not limited to five.

[0015]

As is apparent from the above description, the present invention has the following special effects. (1) It is possible to prevent the wire from falling over in the round hole type roll assembly, prevent the wire from being caught between the rolls, and perform stable wire drawing. (2) The wire diameter can be adjusted by changing the reverse tension. (3) Rolling reaction force is reduced, roll life can be extended, cost can be reduced, and surface defects on the back line of the pressure drawing line are prevented from occurring to improve yield and quality of the final product. Improve. (4) Productivity is improved and energy cost is also reduced.

[Brief description of drawings]

FIG. 1 is a schematic view of an embodiment of a wire drawing apparatus of the present invention.

FIG. 2 is a front view of a three roll assembly.

FIG. 3 is a cross-sectional view of each stand lead wire in the case where wire drawing is performed by changing the reverse tension under the conditions shown in Table 1.

FIG. 4 is a cross-sectional view of each stand lead wire when wire drawing is performed under the conditions shown in Table 2.

FIG. 5 is a graph showing the influence of reverse tension on the wire diameter.

FIG. 6 is a graph showing the influence of reverse tension on the rolling reaction force.

[Explanation of symbols]

 1 to 5 1st wire drawing stand to 5th wire drawing stand 7 Triangle hole type 3 roll assembly 8 Round hole type 3 roll assembly 9 Rolling unit 10 Capstan 11 Dancer roller 13 Forming hole 15 Driving roll 16, 17 Follower roll

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kaiji Shioi 7-5-1, Higashi Narashino, Narashino City, Chiba Prefecture Suzuki Metal Industry Co., Ltd. No. 35 Marusan Machinery Co., Ltd. (72) Inventor Takashi Haratomi 1-2-7 Minejima, Nishiyodogawa-ku, Osaka City, Osaka Prefecture Showa Machinery Works Co., Ltd. (56) Reference JP-A-63-104716 (JP, A) ) JP-A 57-171516 (JP, A) JP-A 1-205801 (JP, A) JP-A 63-268501 (JP, A) JP-B 32-1311 (JP, B1) JP-B 46- 10652 (JP, B2)

Claims (2)

[Claims] 1. A plurality of rolling units having a three-roll assembly are arranged in series so as to roll a wire from three directions, and cold rolling is performed.
In wire drawing method for drawing by the rolling unit
Is a non-driven or motor driven triangle hole type 3 row
Assembly and motor driven round hole type 3 roll assembly
Combining with the body , breaking at the entry line to each rolling unit
A wire drawing method using three rolls, wherein a reverse tension of 20 to 40% of the load is applied . 2. Non-driving or arranged at an angle of 120 °
Triangle hole type consisting of three motor-driven rolls
3 roll assembly, and the motors arranged at an angle of 120 °.
Round hole type 3 rolls consisting of 3 rolls driven by
A rolling unit composed of a combination with an assembly and the rolling unit.
, A dancer roller for applying reverse tension, located upstream of the
And a capstan located downstream of the rolling unit.
A wire drawing machine using three rolls in which a plurality of are arranged .