JP2864923B2 - Continuous rolling mill for fine wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a continuous rolling mill for continuously rolling the following thin wire 1 to 2 mm.

[0002]

2. Description of the Related Art Conventionally, bar and wire rods have been rolled by passing a material to be rolled through various hole-type series with a two-roll type rolling mill. However, in a two-roll type rolling mill, the material swells in the gap between the rolls due to pinching of the rolls. FIG. 4 is a front view of a rolling roll and a material to be rolled in a two-roll rolling method, as viewed from a pass line exit side. The material to be rolled 13 is sandwiched between the rolls 11 and 12 from above and below.
The rolled material 13 swells in the gap direction between the roll material 12 and the roll 12 to have a widened shape. The amount of width expansion is greatly affected by slight variations in the diameter of the material to be rolled, and variations in the tension between rolling mills during continuous rolling. In a two-roll type rolling mill, sufficient accuracy in product dimensions is obtained. There was a problem that it could not be obtained.

A four-roll type rolling mill having a smaller width expansion than such a two-roll type rolling mill is disclosed in, for example, Japanese Patent Application Laid-Open No. 50-140354 (Prior Art 1) and Japanese Patent Application Laid-Open No. 58-303.
(Publicly known technology 2). In a four-roll rolling mill, the rolling component on the material to be rolled acts centripetally and uniformly in a cross section orthogonal to the pass line of the material to be rolled, so that the material to be rolled swells and has a widened shape. To prevent FIG. 5 is a cross-sectional view of a four-roll type rolling mill proposed in the prior art 1 as viewed from a pass line exit side for each stand. The four rolls 21, 22, 23, and 24 are arranged so as to form a substantially square shape. A plurality of such stands rotate the roll arrangement angle with respect to the pass line by 45 °, and sequentially increase the size of the substantially square hole type. It is small and installed in tandem. The rectangular material 25 to be rolled is sandwiched between these four rolls and rolled.
A reduction is applied from the 25 corners to reduce its dimensions.

FIG. 6 is a cross-sectional view of a four-roll type rolling mill proposed in the prior art 2, as viewed from the exit side of the pass line for each stand. The four rolls 31, 32, 33, and 34 are formed by connecting both ends of the rolling surface of a pair of rolls 31 and 33 facing each other to another roll.
A plurality of such stands are placed in tandem such that the dimensions of the substantially square holes are sequentially reduced in such a manner as to overlap the side surfaces of the 32, 34 sides. The rectangular material 35 having a rectangular cross section, which is the material to be rolled, is sandwiched between these four rolls and rolled to reduce its size. In this case, the roll arrangement angle with respect to the pass lines of the plurality of rolling mills is constant, and
The same surface of the is always reduced.

[0005] In the above-mentioned four-roll rolling mill of the prior art 1, the width expansion is small, and the rolling reduction given to the material to be rolled is geometrically large. However, since the rolls are arranged at an angle of 45 ° with respect to the pass line at each of the plurality of stands, the rolled material between the stands, that is, the twist, is extremely likely to occur. FIG. 7 is a cross-sectional view in a direction orthogonal to a pass line of the rolling mill of the four-roll system proposed in the prior art 1. The manner in which the material to be rolled is rolled by this rolling mill will be described. First, a rectangular material 25 with a cross section indicated by a broken line is inserted into the rolling entrance of the rolling mill. At this time, the corners 25a of the material to be rolled contact the roll groove bottoms 21a, 22a. Then, the corners 25a, 25a,... Are rolled down, and are formed into a substantially rectangular hole shape of four rolls 21, 22, 23, 24 as they are rolled. This makes it possible to obtain a high area reduction rate of 25 to 35% per pass.

However, at the start of rolling, the bottom of the roll groove is
The portions in contact with 21a, 22a… are corners 25a, 25a… and the contact area is small, and as the contact width increases by rolling, the restraint by the roll of the rectangular material 25 becomes unstable, and the rectangular material 25 rotates. A moment is applied, and the rectangular material 25 in cross section falls down to the left or right. The larger the ratio of the diagonal dimension D on the entry side cross section to the opposite side dimension d on the exit side cross section of the rectangular section material 25, the greater the rotational moment becomes, and the more likely it is to fall down, that is, torsionally.

As described above, in the four-roll rolling mill of the prior art 1, the material to be rolled is easily twisted, and a guide roller for preventing twisting is required between the stands. When rolling a small-diameter material to be rolled, it is necessary to mount the guide roller immediately before the roll-in side due to a large degree of torsion, but since the interval between the four rolls is narrow, the guide roller is rolled. It becomes difficult to mount immediately before the entry side, and the torsion of the material to be rolled cannot be sufficiently prevented. In addition, although a guide roller can be attached to a material to be rolled having a relatively large diameter, there is a problem that a guide flaw is generated by the guide roller.

On the other hand, in the four-roll rolling mill of the prior art 2, since the width expansion amount is small and the roll arrangement angle with respect to the pass line is constant at all stands,
Since a rolling moment is not applied to the material to be rolled and the material to be rolled is not twisted between the stands, a guide roller for preventing falling is not required. However, there is a problem that the rolled material slightly bites into the roll gap because the rolling is always applied from the same direction.

In order to solve these problems, the present inventor has disclosed in Japanese Patent Application Laid-Open No. 63-168202 (Prior Art 3)
An approximately circular hole type four-roll type rolling mill has been proposed. FIG. 8 is a cross-sectional view of a four-roll type rolling mill proposed in the related art 3 as viewed from the pass line exit side. 4 rolls 41,4
2, 43, 44 are arranged in a substantially circular hole shape, and a plurality of such stands can be arranged at a roll angle of 45 ° with respect to the pass line.
It is installed in a tandem with the size of the substantially circular hole type being sequentially reduced by rotating each time. Round material 45 to be rolled
Is rolled between these four rolls to reduce its size.

[0010] Since such a four-roll type rolling mill has a substantially circular hole shape, the contact area between the rolled material and the roll at the entry side of the rolling is large, and the rolling reduction at the corners as described above. Rather than being applied, since the diagonal dimension and the opposite side dimension are equal, as shown by the arrow in FIG. 8, the centrifugal reduction is applied from the surface of the material to be rolled in the cross section, so that it is difficult for twist to occur, and No biting occurs.

[0011]

However, even in such a rolling mill, the outer diameter of the material to be rolled is further reduced, and
In the case of a material to be rolled having a thickness of 2 mm or less, there is a problem that the material starts to bite into the roll gap during continuous rolling in a multi-stand, though it is slight. To solve this problem, a method of shortening the stand-to-stand distance is conceivable.However, it is necessary to reduce the roll diameter, and in order to secure a normal production speed with small rolls, the roll rotation speed must be increased. However, there is a problem in that the number of rotations is limited and the production efficiency is reduced.

The present invention has been made in view of the above circumstances, and focuses on the above-described factor of the occurrence of the rotational moment, stabilizes the contact between the bottom of the roll groove and the material to be rolled, and generates twist and biting. An object of the present invention is to provide a continuous rolling mill for small-diameter wire rods capable of rolling a small- diameter wire rod without causing the rolling.

[0013]

According to the present invention, there is provided a wire for a thin wire according to the present invention.
Continuous rolling machine, arranged four grooved rolls around the pass line, the thin wire material for a continuous rolling mill for continuously rolling a small-diameter material to be rolled, the four grooved rolls, octagonal hole In order to form a mold, the groove bottom angle is 137 ° to 150 ° on each peripheral surface .
Has a V-shaped groove, moreover mill phase adjacent alternating
Are arranged at a 45 ° angle to each other and have a diameter of 1-2 mm or less.
It is characterized by obtaining a thin wire .

[0014]

In the continuous rolling mill for small-diameter wire rods according to the present invention, the material to be rolled is restrained by the two groove surfaces of the V-shaped groove provided on the grooved roll. Stabilize.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments. FIG. 1 shows a four-roll type thin film of the present invention.
It is a schematic front view of the 1st rolling mill of the continuous rolling mill for diameter wires . The housing 10 having an octagonal shape in front view is provided with vertical and horizontal cross-shaped holes extending in four directions perpendicular to each other from the center thereof.
2, 3 and 4 are shafts 1a, 2a, 3a and 4a at both ends thereof.
Is rotatably inserted into a bearing hole formed in the longitudinal wall surface of the hole, and is supported in a double-supported manner.

A motor (not shown) is connected to one end of the shaft 1a. When the roller 1 is driven by driving the motor, the internal rollers fitted to the roller 1, 2, 3, 4 are mounted. By the gears 6, 6,..., The rolls 2, 3, and 4 are interlocked. Driving the four rolls at the same time in this manner is effective in stabilizing the material W to be rolled into the four rolls and preventing slippage with the rolls during rolling.

FIG. 2 is an enlarged cross-sectional view in the direction orthogonal to the pass line showing the vicinity of the pass line of the continuous rolling mill for small diameter wires according to the present invention. The following description will be made by taking one groove type roll as an example. The peripheral surface of the hole type roll 1 has a groove 1b having a V-shaped cross section at the center in the axial direction of the hole type roll. An inclined surface inclined by 45 ° with respect to the axis is formed. The groove bottom opening angle θ of the V-shaped groove 1b is 4
The rolls are formed at the same angle, and a radius is provided at the bottom of the groove. A radius is also provided at the apex angle formed by the groove 1b having a V-shaped cross section and the inclined surface, and
Are smoothly rolled. At this time, it is desirable that the radius is set to about one third to one fifth of the octagonal diagonal dimension. Such a roll 4
Individual pieces are arranged around the pass line with grooves 1b, 2b, 3b, 4b having a V-shaped cross section, and form discontinuous octagonal holes at four points between the grooved rolls.

The output side of the continuous rolling mill for small diameter wire rods having such a configuration is provided with a second, third, and a substantially similar configuration as the first rolling mill.
A rolling mill and a plurality of rolling mills (not shown) are installed in tandem at an appropriate distance. FIG. 3 is a schematic front view showing the structure of each of these rolling mills as viewed from a pass line exit side.
The pass lines of the four roll-shaped rolls so that the unconstrained portions of the material to be rolled W, which pass through the free surface, which is the discontinuous portion of the octagonal hole, do not overlap in each of the rolling mills 10, 20, 30,. For example, in the illustrated example, the center angles of the surroundings are different by 45 ° between adjacent rolling mills. The central angle is not limited to 45 ° and may be any angle that can achieve a predetermined purpose.

The small-diameter wire according to the present invention configured as described above.
The result of rolling a small-diameter wire rod using a 13-stand rolling mill including a continuous rolling mill for rods will be described below. The material W to be rolled is a stainless steel wire SUS304 having an outer diameter of φ3 mm, and a continuous rolling mill for small diameter wire according to the present invention is used for the upstream 11 stands. 2b, 3
The groove bottom opening angle θ of b and 4b is set to 141 °, and the area reduction rate per stand is set to 12%. The lowermost two stands use a 4-roll circular hole rolling mill, the distance between the 13 stands is 110 mm, the exit rolling speed is 100 m / min, and the exit dimension of the material W to be rolled is φ.
A rolled material W of 100 kg × 3 coils was rolled in a cold state while the thickness was set to 1.5 mm.

As a result, the rolled material was rolled with a dimensional accuracy of φ1.5 mm ± 0.02, and no twist or biting occurred in the rolled material, and no flaw was observed. In order to cool and lubricate the material W to be rolled and the tool during rolling, a water-soluble lubricant was used. Further, the upstream side of the rolling mill of the present invention
After rolling into an octagonal cross section by 11 stands, the downstream side 2
It is finally formed into a circular cross section by the circular hole rolling mill of the stand.

Next, the groove bottom opening angle θ of the four rolls of the continuous rolling mill for small diameter wire rods according to the present invention is set to 135 °, 137 °, 142 °, 150 °.
° and 155 °, and rolling was carried out under the same conditions as in the above-mentioned examples except for this. Table 1 shows the results.

[0022]

[Table 1]

As is clear from Table 1, when θ was 135 °, slight biting occurred, and when θ was 155 °, twisting occurred. From this, in the rolling under the above conditions, the groove bottom opening angle θ of the four rolls is 137 ° <θ <150 °
Is preferable.

In this embodiment, a case is described in which the two most downstream stands use a four-roll circular hole rolling mill to produce a rolled material having a circular cross section. A rolled material having an octagonal cross section can also be manufactured by using the continuous rolling mill for small-diameter wire having the mold according to the present invention.

In this embodiment, the case where the stainless steel wire is rolled is described. However, the present invention is not limited to this, and is applicable to carbon steel, high alloy steel, and fine wire of various nonmetallic materials. it can.

[0026]

As described above, the present invention is an octagonal hole continuous rolling mill provided with a grooved roll having a V-shaped groove on the roll peripheral surface. restraint is stabilized at the bottom, twist, fine without generating chew out
The present invention has excellent effects such as continuous rolling for diameter wire rods .

[Brief description of the drawings]

FIG. 1 is a schematic front view of a first rolling mill of a continuous rolling mill for small-diameter wire rods of a four-roll system according to the present invention.

FIG. 2 is an enlarged cross-sectional view in the direction orthogonal to the pass line, showing the vicinity of the pass line of the continuous rolling mill for small diameter wires according to the present invention.

FIG. 3 is a schematic front view showing a structure of a case where a plurality of continuous rolling mills for a thin wire according to the present invention are arranged.

FIG. 4 is a front view of a rolling roll and a material to be rolled in a conventional two-roll rolling method.

FIG. 5 is a sectional view of a conventional four-roll type rolling mill.

FIG. 6 is a cross-sectional view of a conventional four-roll rolling mill.

FIG. 7 is a sectional view of a conventional four-roll rolling mill.

FIG. 8 is a front view of a conventional four-roll rolling mill.

[Explanation of symbols]

 1,2,3,4 hole type roll 1a, 2a, 3a, 4a shaft 1b, 2b, 3b, 4b V-shaped groove 5 octagonal hole type 6 internal gear

Claims (1)

(57) [Claims] 1. A arranged four grooved rolls around the pass line, the thin wire material for a continuous rolling mill for continuously rolling a small-diameter material to be rolled, the four grooved rolls, octagonal hole In order to form the mold, V-shaped grooves having a groove bottom angle of 137 ° to 150 ° are formed on each peripheral surface.
And the phases of adjacent rolling mills are alternately shifted by 45 °
To obtain a thin wire with a diameter of 1-2 mm or less.
Thin wire material for a continuous rolling mill, characterized in that that.