JPH06501A - Device for manufacturing wire rod with thin diameter - Google Patents

Abstract

PURPOSE:To accurately manufacture a wire rod whose diameter is smaller than a specified value by a rolling method. CONSTITUTION:By rolling a wire rod W of a material using a continuous rolling mill 4 which is composed by arranging plural 4-way roll rolling stands 40 having circular grooves in tandem, the wire rod SW with a small diameter of <=5 mm is manufactured. In the continuous rolling mill 4, the bottom position of roll groove of each of adjacent rolling stands 40, 40 is mutually inclined by 45 deg.C around the pass line and the center distance between adjacent respective rolling stands 40, 40 is set not more than 50 times the diameter of the wire rod W which is passed through them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing a thin wire having a diameter of 5 mm or less.

[0002]

2. Description of the Related Art As a method for producing a thin wire rod made of a metal such as steel having a diameter of 5 mm or less, a billet as a raw material is first subjected to a wire rod rolling step consisting of a rough rolling stand group, an intermediate and a finishing stand group. The diameter is 5.
BACKGROUND ART A method is conventionally known in which a wire having a diameter of 5 mm or more is manufactured, and then the manufactured wire is drawn by a die drawing method to gradually reduce the diameter.

However, the drawing method requires a narrowing at the time of passing the wire, and a complicated lubrication process depending on the material. Further, the material breaks when the tension acting during the drawing increases, so that the drawing method is performed once. This is a working method that is inferior to the rolling method in workability and efficiency, such as the rolling reduction after annealing being limited.
In the rolling method, the diameter of the wire that can be produced is generally limited to about 5.5 mm for the following reasons.
The die drawing method was applied to a wire rod having a diameter of about 5.5 mm manufactured by the rolling method to manufacture a thin wire rod having a diameter of 5 mm or less.

Generally, when bar-shaped or wire-shaped is rolled,
As shown in FIG. 6, a hole-type array such as circle-ellipse-round for two rolls, circle-triangle-round for three rolls, square-square-round for four rolls is used. In either case, when rolled into a circle, the material to be rolled rotates around the axis at the lower part of the roll and twists, so-called tilting occurs. Once a collapse occurs, the collapsed state does not return to the original state due to the aspect ratio of the cross-sectional dimension of the material to be rolled, and it does not return to the original state, resulting in a reduction different from the designed pass schedule and the material in the roll gap. Biting out makes it difficult to continue rolling. Therefore, in order to prevent this fall, a fall prevention guide for holding the material to be rolled is incorporated in the entrance side of the circular hole type. However, even when such a fall prevention guide is attached, if the dimension of the material to be rolled becomes small, it becomes impossible to prevent the material to be rolled from falling at the roll pressure lower part. This is because the rolled material itself tends to be twisted due to the smaller cross-sectional shape, and the fall prevention guide cannot be relatively brought closer to the roll pressure lower portion due to the smaller rolled material diameter. This is because even if the rolled material has a twist angle, the rolled material falls down at the roll lower part.

As a means for solving the above problems and producing a thin wire, there is a method and apparatus disclosed in Japanese Patent Application Laid-Open No. 63-168202 filed by the present inventors.
This adopts a circular hole type and manufactures a small-diameter wire rod by rolling without providing a guide for preventing tilting between stands.

FIG. 7 is a schematic side view of the conventional apparatus for manufacturing a thin wire rod disclosed in Japanese Patent Laid-Open No. 63-168202. In this apparatus, a plurality of rolling stands 40 having a plurality of hole type rolls are arranged in a tandem to form a continuous rolling mill 4, and a rewinding machine 1 around which a wire W is wound is used as an inlet side of the continuous rolling mill 4. In addition, the winding machine 2 for winding the manufactured small diameter wire SW is provided on the exit side of the continuous rolling machine 4. And
At first, the leading end of the wire W is passed through the continuous rolling mill 4 at a low speed, and the leading end is wound around the winder 2. Then, the continuous rolling mill 4 rolls the wire W at a high speed. It is designed to wind a small diameter wire SW. The winder 2 controls the tension of the small diameter wire SW according to the rolling speed of the continuous rolling mill 4 so that the small diameter wire SW is stretched with a tension not to loosen, and the high speed rolling is performed. The small-diameter wire SW is wound into an aligned multi-layer winding or a quasi-aligned multi-layer winding in order to meet the above requirement.

The characteristic of this method is that the hole type of the hole type roll is a circular hole type, and the rolling stands 40 adjacent to each other are arranged so that the unconstrained portions of the roll hole types do not overlap. It is that you are. With a round-round-round hole array,
The feature is that rolling can be performed without biting even if the material to be rolled is twisted between stands, and the aspect ratio of the material to be rolled when rolling is close to 1 in the round-round hole type. By utilizing the feature that the twisting moment of the tilt that occurs in 1) is small, a thin wire is manufactured by the rolling method without attaching a tilt prevention guide.

The above-described method not only facilitates the rolling of a thin wire having a diameter of 5 mm or less, which has been conventionally considered difficult to manufacture by rolling, but also causes surface flaws caused by contact with a tipping prevention guide. It is possible to produce a thin wire rod with much higher efficiency than the wire drawing method that has been conventionally used for producing a thin wire rod.

By the way, as a method of sizing a rod wire with a 4-roll circular hole type, there is a method disclosed in Japanese Patent Publication No. 3-6841. This sizing method is 2
The four-roll rolling stands of the table are arranged at a 45 ° offset from each other, and the incorporated eight roll cavities have a shape in which an arc of the same or 120% diameter with respect to the diameter of the material and an appropriate relief are arranged, It is characterized by arbitrarily selecting the roll reduction and sizing within the same range as the diameter of the material or within 80% of the diameter. The 4 rolls have a small width spread, and the 4 rolls have a geometric characteristic that the hole shape does not easily deviate from the target circle even if the roll reduction amount is adjusted. Manufacture rod wire rods of various finish sizes without any.

[0010]

SUMMARY OF THE INVENTION
When the inventors of the present invention tried an additional test on the method and apparatus disclosed in Japanese Patent Publication No. 63-168202, when the diameter of the manufactured thin wire rod was further reduced, the wire rod was twisted between adjacent rolling stands. It was found that the hole-shaped unconstrained part became an unrestrained part even in the next rolling stand and the material was bit into the hole-shaped roll, so that it was not possible to manufacture a fine wire SW with high accuracy. It was also found that the effect cannot be sufficiently obtained in the following cases even if the diameter of the wire is not very small. When the dimensional accuracy and assembling accuracy of the hole shape of the roll are low When targeting metal materials of various materials (for example, materials with crystal anisotropy, non-ferrous metal materials such as titanium and titanium alloys, hardness is High material) When the tension between rolling stands in a continuous rolling mill is low When the wire condition at the tip of the wire rod is poor (for example, when the tip of the wire rod introduced into the rolling stand is markedly bent) As described above, The method and apparatus disclosed in Japanese Patent Laid-Open No. 63-168202 have some problems to be solved and there is room for improvement. .

On the other hand, in the method disclosed in Japanese Examined Patent Publication No. 3-6841, the object to be applied is a steel bar having a diameter of 22 to 120 mm which is generally manufactured in a steel bar factory and has a diameter of 5 mm or less. This method cannot be applied to the production of wire rods.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an apparatus for manufacturing a thin wire having a diameter of 5 mm or less with high accuracy.

[0013]

An apparatus for producing a thin wire rod according to the present invention is an apparatus for producing a thin wire rod having a diameter of 5 mm or less by rolling a wire rod of a material by a continuous rolling mill. A plurality of 4-way roll rolling stands having circular hole shapes are arranged in tandem, and the groove bottom positions of the roll hole shapes of the adjacent rolling stands of the continuous rolling mill are tilted about 45 ° with respect to each other around the pass line. Further, the distance between the circular hole dies in the pass line direction of the adjacent rolling stands of the continuous rolling mill is 50 times or less than the average diameter of the wire rod passing between the adjacent rolling stands.

[0014]

In the apparatus for manufacturing a thin wire of the present invention, a plurality of four-way roll rolling stands having circular hole shapes are provided such that the groove bottom positions of the roll hole shapes of adjacent rolling stands are around each other around the pass line. It is tilted at 45 °, and the distance between the centers of adjacent rolling stands in the pass line direction is 50 times or less than the average diameter of the wire (rolled material) passing through it.
Using a continuous rolling mill arranged in tandem, the material wire rod is rolled to produce a thin wire rod having a diameter of 5 mm or less. Four
The reason for using the single roll rolling stand and the reason for limiting the distance between the centers of the adjacent rolling stands to 50 times or less of the wire diameter will be described below.

Twisting (tilting) between circular hole type rolling stands
As a result of investigating the phenomenon described above, it was found that twisting is more likely to occur in the 2 rolls and 3 rolls than in the 4 rolls. The reason for this is as follows. For example, in the case of 2 rolls,
It has a fairly wide width characteristic, and the material flows to the unconstrained part of the roll gap when the roll is pressed in the axial direction of the material to be rolled. large. Therefore, in the case of the two-roll hole rolling method having a circular hole shape, it is necessary to increase the relief amount on both sides of the roll in order to prevent the roll gap from being caught. This means that the amount of reduction when reducing the bulge of this material in the next rolling stand becomes large. Therefore, since the aspect ratio of the material to be rolled is increased, the material to be rolled easily rotates around the axis, leading to a fall. In order to avoid such a fall, it is conceivable to reduce the rolling reduction per rolling stand to reduce the relief portions on both sides of the roll. Then, the rolling reduction required to obtain the same total rolling reduction is achieved. The number of stands will be huge and the equipment cost will increase. In the case of 3 rolls, the tendency of width expansion is smaller than that of 2 rolls, but the condition is worse than that of 4 rolls. Therefore, in order to suppress rolling between the rolling stands without providing a guide for preventing the rolling between the rolling stands and to suppress the twist between the rolling stands, the present invention uses a continuous rolling machine having a four-roll circular hole type.

By adopting the 4-roll circular hole type, for example, rolling a thin wire having a diameter of 3 mm, 2 mm, or 1 mm, and examining the conditions under which rolling can be performed without twisting between the rolling stands, the distance between the rolling stands can be determined. It has been confirmed that if the material diameter is 50 times or less, stable rolling can be realized without falling even if the above-mentioned various factors that cause falling easily act. 2 rolls,
In case of 3 rolls, the distance between rolling stands is 30
Even if set to double or 40 times, the area reduction rate per stand: 10%
It was confirmed that a collapse would occur. For the production of a thin wire having a diameter of 5 mm or less, it is not practical to reduce the stand interval to 30 to 40 times or less because the roll diameter becomes extremely small. Therefore, in the present invention, the distance between the centers of adjacent rolling stands is set to 50 times or less the diameter of the wire passing therethrough.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments.

FIG. 1 is a schematic side view of an apparatus for manufacturing a thin wire according to the present invention. A turntable-type horizontal rewinding machine 1 around which the wire W is wound is arranged at the most upstream side of the manufacturing line in the apparatus for manufacturing small-diameter wire. On the downstream side of the rewinding machine 1, a straightening machine 3 provided with a guide roller 30 on its inlet side.
And the wire W sent from the rewinding machine 1 is
The bend is corrected by the correction machine 3. At the downstream side of the straightening machine 3, a continuous rolling mill 4 having guide rollers 41 and 42 on its inlet side and outlet side is disposed. The continuous rolling mill 4 has a plurality of rolling rolls 40, 40, ... Of four rolls having a circular hole type, which are arranged in tandem as described later. The hole-shaped rolls are arranged so that the non-restrained portions do not overlap each other, and the wire W sent from the straightening machine 3 is continuously rolled to obtain the thin wire SW. Continuous rolling mill 4
A vertical winder 2 for winding the small-diameter wire SW through a swing roller 5 arranged as a traverse mechanism for aligning and winding the small-diameter wire SW is disposed on the downstream side. The swing roller 5 is adapted to reciprocate in consideration of the diameter of the small diameter wire SW, and according to the number of rotations of the winding machine 2, the small diameter wire SW is wound in line around the winding machine 2. .

The structure of each rolling stand 40 is shown in FIG. The housing 40d, which has an octagonal shape when viewed from the front, has vertical and horizontal cruciform holes formed in four directions orthogonal to each other from the center of the housing, and the four hole-shaped rolls 40a, 40a, 40a, 40a are formed in the holes. Is provided by inserting the roll shafts 40b, 40b, 40b, 40b into bearing holes formed in the wall surface of the holes. One end side of the roll shaft 40b of one hole type roll 40a serves as an input shaft and is connected to a drive mechanism (not shown), and this hole type roll 40a is driven. The other three hole-type rolls 40a, 40a, 40a are driven by driving force transmitted to each of them by a bevel gear 40c attached to the side surface thereof. And each of the four rolls
The peripheral surface of 40a has a hole forming groove 40f at the center of the roll axial direction, and on both sides of it there is an inclined surface with the radius of both ends of the hole forming roll 40a smaller than the radius of both ends of the hole forming groove 40f. Has been formed. This inclined surface is 45 ° to the roll axis
Since it is inclined, a circular hole die 40e is formed at the center of the housing 40d by the four hole die forming grooves 40f, and the wire rod W passes through the circular hole die 40e and is rolled. As shown in FIG. 3, both ends of the hole shape of each hole type roll 40a have a relief portion (for example, 2R) having a diameter (for example, 2R) larger than an extension line (shown by a chain line) of the radius of curvature R at the central portion in the axial direction. A is shown by a solid line).

A plurality of rolling stands 40 having such a configuration
Are arranged in tandem in the pass line direction as shown in FIG. 4 (a). 4 (a) and (C) are horizontal stands, (B) is a 45 ° tilt stand, and FIG. 4 (b) shows the respective roll arrangements. Thus, the horizontal stand 4
The continuous rolling mill 4 is constructed by alternately arranging the inclined stands 40, and the groove bottom positions of the adjacent rolling stands 40, 40 are inclined by 45 ° around the pass line. The reduction rate of each rolling stand 40 is set to 15% or less, and the four roll circumferences are set so that the unconstrained portions of the wire W passing through the free surface which is the circular hole type discontinuous portion do not overlap at each rolling stand 40. For example, in the illustrated example, the center angles around the pass line of the surface are different by 45 ° between the adjacent rolling stands 40, 40. This central angle does not have to be 45 °, but in order to suppress the twist of the material to be rolled (wire W), which is the focus of the present invention, it is 45 ° ± 2 °.
The accuracy of is desirable. The center-to-center distance L between adjacent rolling stands 40, 40 is 50 mm, which is the diameter d of the wire W passing therethrough.
It is set to less than double. Further, as shown in FIG. 5, a cylindrical guide pipe 43 is provided between the adjacent rolling stands 40, 40. The inner diameter of the guide pipe 43 is slightly larger than the diameter of the wire W passing through it.

The rolling speed of each rolling stand 40 of the continuous rolling mill 4 is set in accordance with the area reduction rate, that is, the hole type passing amount per unit time becomes constant. The rolling speed of the rolling stand 40 on the outgoing side of the stand 40 is higher. Further, the winding speed of the winding machine 2 is determined according to the rolling speed of the rolling stand 40 at the exit end.

Next, a manufacturing operation of a thin wire rod using the apparatus having such a structure will be described. First, the wire W fed from the coil C1 mounted on the rewinding machine 1 is supplied to the straightening machine 3 via the guide roller 30 and straightened, and then sent to the inlet of the continuous rolling mill 4. The continuous rolling mill 4 is driven at a low speed, and the wire W is guided while being guided by the guide pipe 43 and fed to the outlet of the continuous rolling mill 4. The tip of the thin wire SW fed to the exit of the continuous rolling mill 4 is attached to the swing roller 5
It is sent to the winder 2 through the and wound around the winder 2. When the wire passing process from the rewinding machine 1 to the winding machine 2 is completed, the continuous rolling mill 4 is driven at a high speed to perform high speed rolling. The wire W supplied from the rewinding machine 1 to the continuous rolling machine 4 is successively reduced in diameter at each rolling stand 40 to become a small diameter wire SW having a predetermined size, and this small diameter wire SW is fed to the winding machine 2. The coil C2 of the thin wire SW is obtained by being wound.

After the wire passing process is completed, the wire W is positioned at the center of the pass line by the tension between the rolling stands 40, so that the wire W does not come into contact with the guide pipe 43 during the high speed rolling, and there is no problem. . Further, since the wire rod W is restrained by the circular hole die 40e and the distance between the adjacent rolling stands 40 is set to 50 times or less the diameter of the wire rod, the twisting of the wire rod W between the adjacent rolling stands 40 can be suppressed, and the wire rod W can be suppressed. There is no danger of falling. Further, since the area reduction rate is set to 15% or less for each rolling stand 40, and the relief portion is formed in each hole type roll 40a, the material is prevented from being caught. Further, since each hole type roll 40a is supported on both end sides, the hole type roll 40a
There is no bending and the dimensional accuracy of the thin wire SW is high. As described above, according to the present invention, it is possible to manufacture the small diameter wire SW with high efficiency and high accuracy without providing the guide for preventing the tilt unlike the conventional example.

Next, a specific example of manufacturing a thin wire using the manufacturing apparatus of the present invention will be described.

A wire rod made of pure titanium (diameter: 5.5 mm) was cold-rolled using 24 rolling stands with a surface reduction rate of 10% per pass to obtain a thin wire rod having a diameter of 1.6 mm. Was produced (first example). Further, the same wire rod was heated to 850 ° C. and hot-rolled to manufacture a similar thin wire rod (second example). The manufacturing conditions are as follows for both the first and second examples. Distance between adjacent rolling stands: 80 mm, hole roll diameter: 80
mm, Rolling stand type: 4-way roll, Hole type: Round hole type In both cases, the manufactured thin wire rod has no surface flaw, and the dimensional accuracy is 1.6 ± 0.015 (mm) (first example), 1.6 ± 0.
It was 03 (mm) (second example), and the rolling process of several tons could be performed without the wire rod falling over.

On the other hand, as a comparative example, when the distance between adjacent rolling stands was changed to 120 mm and the same manufacturing experiment was conducted, the wire rod collapsed when the diameter of the wire rod became smaller than 2.4 mm, and 5 coil Three coils out of one coil (200 kg) failed to be rolled.

A stainless steel (SUS304) wire rod (diameter 5.5 mm) was used as a material, and the area reduction rate per pass was 10%.
Cold rolling was performed using the 24 rolling stands, and a thin wire rod having a diameter of 1.6 mm was manufactured. The manufacturing conditions are as follows. Distance between rolling stands next to each other: 80 mm, hole roll diameter: 85
mm, Rolling stand type: 4-way roll, Hole type: Round hole type There was no surface flaw in the thin wire rod produced, and the wire rod did not collapse even after rolling several tons.

Although specific examples of pure titanium and stainless steel have been described, various other non-ferrous metal materials and ferrous materials such as carbon steel and stainless steel can also be used with the present invention to accurately produce thin wire rods. Of course, it can be manufactured.

[0029]

As described above, in the apparatus for manufacturing a thin wire rod according to the present invention, a plurality of 4-way roll rolling stands having circular hole shapes are provided so that the groove bottom positions of the roll hole shapes of adjacent rolling stands pass. They are arranged in tandem so that they are tilted about 45 ° around each other and the distance between the centers of adjacent rolling stands in the pass line direction is 50 times or less than the average diameter of the wire passing therethrough. A continuous rolling mill is used to roll a wire rod of a material to produce a thin wire rod having a diameter of 5 mm or less. Therefore, it is possible to accurately manufacture a thin wire rod without providing a fall prevention guide between adjacent rolling stands. Moreover, the structure of the continuous rolling mill can be made compact.

[Brief description of drawings]

FIG. 1 is a schematic side view of an apparatus for manufacturing a thin wire according to the present invention.

FIG. 2 is an enlarged front view showing the configuration of each rolling stand in FIG.

FIG. 3 is an explanatory diagram of a relief portion of the hole type roll in FIG.

FIG. 4 is an explanatory diagram showing an arrangement of rolling stands in FIG.

5 is a partially enlarged sectional view of FIG.

FIG. 6 is a schematic view showing a hole type arrangement of a hole type roll.

FIG. 7 is a schematic side view of a conventional apparatus for manufacturing a thin wire.

[Explanation of symbols]

 1 Rewinder 2 Rewinder 3 Straightener 4 Continuous rolling mill 40 Rolling stand 40a Hole type roll 40e Circular hole type 43 Induction pipe W Wire rod SW Small diameter wire rod

Claims (1)

[Claims] 1. An apparatus for producing a thin wire having a diameter of 5 mm or less by rolling a wire rod of a material by a continuous rolling mill, wherein the continuous rolling mill has a plurality of four-way rolling stands having a circular hole type arranged in tandem. Further, the groove bottom position of the roll hole type of the adjacent rolling stand of the continuous rolling mill is tilted about 45 ° with respect to each other around the pass line, and the pass line of the adjacent rolling stand of the continuous rolling mill is further formed. An apparatus for producing a thin wire rod, characterized in that a distance between circular hole dies in a direction is 50 times or less of an average diameter of a wire rod passing between adjacent rolling stands.