JPH1128504A - Manufacture of metal stock having round shape in cross section and its manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To widen a size free zone, to make the finish cross section shape about complete round even though the rolling reduction is varied and to reduce the difference of deviated diameter by mutually arranging with an inclination respective roll axes of a pair of rolling roll in a two-roll rolling mill in the inverse direction or the same direction to the advancing direction of the stock to be rolled to execute finish rolling. SOLUTION: The upstream side rolling mill Sn+1 of the last two two-roll rolling mills in a finishing mill group 6 is provided with the reduction regulating mechanism of a pair of rolling rolls 1, and the distance between the roll groove bottoms of the rolling mill Sn+1 is set so as to get closer to the objective finish diameter. The downstream side two-roll rolling mill Sn+2 is provided with the reduction regulating mechanism of a pair of the rolling rolls 1 and provided with the mechanism arranging with an inclination respective roll axes of the roll 1 to the advancing direction of the stock 2 to be rolled. Therefore, the practical size free rolling having the finish cross section shape of about the complete round, the small difference of deviated diameter and moreover the wide size free zone is executed with the two-roll rolling mill.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a metal material having a circular cross section and an apparatus for manufacturing the same, comprising a group of upstream rolling mills and a group of finishing mills installed downstream of the group of rolling mills. The present invention relates to a method for manufacturing a metal material having a circular cross section and an apparatus for manufacturing the same. More specifically, the same roll (hole-shaped roll) is used, and the rolling position of the roll and the inclination angle of the roll shaft are changed in a stepless manner, so that the material to be rolled (metal material having a circular cross section) after finish rolling is performed. The present invention relates to a stepless continuous rolling method capable of changing a diameter steplessly and a rolling apparatus for the method.

[0002]

2. Description of the Related Art A metal material having a circular cross-sectional shape, for example, a wire or a bar made of various metal materials as a base material is finished to a desired size (diameter) by "primary processing" such as rolling. In addition, a so-called "secondary / third-order processing" is performed to finish a final industrial product having a desired shape. For this reason, in order to improve the yield and work efficiency in “secondary and tertiary processing”, a metal material having a circular cross-sectional shape as it is finished in “primary processing” is required to have high precision dimensions at a fine pitch. .

[0003] Therefore, when rolling a metal material having a circular cross section, a roll (hollow roll) is generally prepared for each dimension (diameter) of the rolled product, and the finishing diameter (hereinafter referred to as the finishing diameter) is slightly changed. It has been carried out to change the roll according to. However, in the case of this general rolling method, the production efficiency is reduced due to the roll change, and it is necessary to have a large number of rolls.

[0004] In order to solve such a problem, a technique relating to a so-called "size-free rolling" in which the roll reduction position is steplessly adjusted by using the same roll and the finishing diameter can be steplessly changed by this, for example, is disclosed in, Kaihei 1-2101
No. 02 and JP-A-6-134502.

Japanese Patent Application Laid-Open No. Hei 1-210102 discloses a "rolling method without a holding and guiding tool for a strip" in which a two-roll or three-pass two-roll rolling mill having a rolling reduction function is used as a forming rolling mill group (finishing rolling mill group). Has been proposed. According to the technique described in this publication (hereinafter referred to as Conventional Technique 1), it is possible to increase the finishing dimensional accuracy, and to omit the function of the holding guide, thereby simplifying the structure of the rolling mill. The effect is obtained. However, the total area reduction rate of the forming and rolling mill group is as small as 15% or less, and the distance between the rotation axes of the rolling rolls between each pass needs to be as small as 30 times or less the dimension of the material to be rolled. However, the size of the rolled product is naturally limited, and it is difficult to apply to a product having a small finish diameter. Even if the compacting and rolling mill group is made compact so that it can be applied to products with small finishing diameters, the area reduction rate in the rough rolling mill group and the intermediate rolling mill group is small enough to be rolled by the compacting and rolling mill group. Therefore, the rolling pass schedule becomes extremely complicated. Further, since the forming and rolling mill group is composed of a combination of a vertical rolling mill having a normal vertical roll and a horizontal rolling mill having a normal horizontal roll, the product shape after the forming and rolling is as shown in FIG. Becomes almost square.

Japanese Patent Application Laid-Open No. 6-134502 discloses a 90
圧 延 Rolling is performed by a plurality of two-roll rolling mills that are continuously arranged in a phase,
A “rolling method for round bars and wires and a rolling device used for the method” have been proposed in which rolling is performed by a roll rolling mill from four directions inclined at 5 ° and the diameter is reduced to reduce the deviation in diameter (the amount of inflow and out of the target diameter). I have. According to this technology (hereinafter referred to as Conventional Technology 2), the diameter deviation is smaller than that of the “size-free rolling” method in which a normal two-roll rolling mill group having a substantially square cross section is used as a finishing rolling mill group. About 1/4,
It is possible to expand the size free area. However, according to the prior art 2, the cross-sectional shape of the finished product is almost octagonal as shown in FIG.
This is not qualitatively different from the "size-free rolling" of the related art 1 or the like in which the finished cross-sectional shape using the roll rolling mill group as the finishing rolling mill group is substantially square.
In the case of a round hole type roll, if the radius r of the roll hole type groove perfectly round region (hereinafter, simply referred to as the roll hole type true circle region) is equal to １ ／ of the finishing diameter d, the finished cross-sectional shape is close to a perfect circle. However, as the product size is reduced by increasing the rolling reduction, the cross section becomes substantially octagonal, and the deviation in diameter (the difference between the maximum and minimum diameters in the same cross section of the finished product) increases.

There is an extremely large demand for improving the dimensional accuracy of a metal material having a circular cross-sectional shape while being rolled as "primary processing". In addition, the tolerance of the eccentricity difference tends to become smaller. It is extremely difficult to respond to such a demand by the conventional “size-free rolling” technology in which the finished cross-sectional shape is substantially quadrangular or octagonal.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has a wide size-free area, a substantially perfect finished cross-sectional shape and a small eccentric difference even if the amount of reduction varies. It is an object of the present invention to provide a “size-free rolling” method as a method for manufacturing a metal material having a circular shape, and a group of rolling machines as a manufacturing apparatus thereof, particularly a group of finishing rolling machines.

[0009]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a method of manufacturing a metal material having a circular cross section shown in the following (1) to (3) and a method of manufacturing a metal material having a circular cross section shown in (4) to (6). It is in the manufacturing equipment for metal materials.

(1) A plurality of continuous rolling mills in which two two-roll rolling mills continuously arranged in a 90 ° phase are the last two rolling mills in a finishing rolling mill group. A method of manufacturing a material, wherein each roll axis of a pair of rolling rolls of a two-roll rolling mill on a downstream side of the last two rolling mills in the finishing mill group is set with respect to a traveling direction of a material to be rolled. A method of manufacturing a metal material having a circular cross-sectional shape, wherein a finish rolling is performed by arranging them in mutually opposite directions or arranging them both in the same direction.

(2) A plurality of continuous rolling mills in which two two-roll rolling mills continuously arranged in a 90 ° phase are the last two rolling mills in the finishing rolling mill group. A method of manufacturing a material, wherein each roll axis of a pair of rolling rolls of a two-roll rolling mill on the upstream side of the last two rolling mills in the finishing mill group is set with respect to a traveling direction of a material to be rolled. The roll shafts of a pair of rolling rolls of the downstream two-roll rolling mill are arranged in a direction opposite to each other with respect to the advancing direction of the material to be rolled, and the upstream two-roll rolling mills are arranged in the opposite directions. The cross-sectional shape of a metal material having a circular cross-section, which is characterized by being arranged in the opposite direction to the direction of the roll rolling mill, or being subjected to finish rolling by both being arranged in the same direction with respect to the traveling direction of the material to be rolled and arranged in the same direction. Production method.

(3) A plurality of continuous rolling mills in which two two-roll rolling mills continuously arranged in a 90 ° phase are the last two rolling mills in the finishing rolling mill group. A method of manufacturing a material, wherein each roll axis of a pair of rolling rolls of a two-roll rolling mill on the upstream side of the last two rolling mills in the finishing mill group is set with respect to a traveling direction of a material to be rolled. Both rolls are inclined in the same direction, and the roll axes of a pair of rolling rolls of the two-roll rolling mill on the downstream side are both inclined in the same direction with respect to the traveling direction of the material to be rolled. A method for producing a metal material having a circular cross-sectional shape, wherein a finish rolling is carried out by arranging the rolled material in a direction opposite to the traveling direction of the rolled material.

(4) A rolling mill group consisting of a plurality of two-roll rolling mills continuously arranged at 90 ° phase, and two or more two rolls continuously arranged at 90 ° phase downstream of the rolling mill group. A device for manufacturing a metal material having a circular cross-section constituted by a finishing mill group consisting of rolling mills, wherein each two-roll rolling mill of the last two rolling mills in the finishing mill group is a roll reduction machine. An adjusting mechanism is provided, and a downstream two-roll rolling mill among the final two rolling mills has a roll axis inclined arrangement mechanism, and each roll axis of a pair of rolling rolls of the rolling mill is a material to be rolled. A device for manufacturing a metal material having a circular cross-sectional shape, wherein the device is arranged to be inclined in directions opposite to each other with respect to the traveling direction or both are arranged to be inclined in the same direction.

(5) A rolling mill group composed of a plurality of two-roll rolling mills continuously arranged at 90 ° phase, and two or more two rolls continuously arranged at 90 ° phase downstream of the rolling mill group. A device for manufacturing a metal material having a circular cross-section constituted by a finishing mill group consisting of rolling mills, wherein each two-roll rolling mill of the last two rolling mills in the finishing mill group is a roll reduction machine. It has an adjusting mechanism and a roll axis tilt arrangement mechanism, and each roll axis of a pair of rolling rolls of an upstream two-roll rolling mill among the final two rolling mills is mutually moved with respect to a traveling direction of a material to be rolled. The roll shafts of a pair of rolling rolls of the downstream two-roll rolling mill are arranged in a reverse direction, and the roll axes of the pair of rolling rolls are opposite to each other with respect to the advancing direction of the material to be rolled and the upstream two-roll rolling mill Inclined arrangement in the opposite direction to that of the machine,
Alternatively, an apparatus for manufacturing a metal material having a circular cross-sectional shape, wherein both are arranged obliquely in the same direction with respect to the traveling direction of the material to be rolled.

(6) A rolling mill group consisting of a plurality of two-roll rolling mills continuously arranged at 90 ° phase, and two or more two rolls continuously arranged at 90 ° phase downstream of the rolling mill group A device for manufacturing a metal material having a circular cross-section constituted by a finishing mill group consisting of rolling mills, wherein each two-roll rolling mill of the last two rolling mills in the finishing mill group is a roll reduction machine. It has an adjusting mechanism and a roll axis inclined arrangement mechanism, and each roll axis of a pair of rolling rolls of the upstream two-roll rolling mill of the final two rolling mills is both in the traveling direction of the material to be rolled. The roll shafts of a pair of rolling rolls of the two-roll rolling mill on the downstream side are both inclined and arranged in the same direction with respect to the traveling direction of the material to be rolled, or the material to be rolled. Slanted in the opposite direction to the direction of travel Sectional shape, wherein Rukoto manufacturing apparatus for circular metal material.

Hereinafter, the above (1) to (6) will be referred to as the inventions of (1) to (6), respectively.

Here, “2 consecutively arranged at 90 ° phase”
The “roll rolling mill” refers to a two-roll rolling mill that is continuously arranged in which the rolling directions are orthogonal to each other, and for example, a combination of a so-called “horizontal rolling mill” and a “vertical rolling mill” applies to this. In addition, when the roll axis of one or both of the above-mentioned "horizontal rolling mill" and "vertical rolling mill" or a pair of rolling rolls is inclined, the rolling direction is not inclined. Therefore, the rolling direction of each rolling mill is orthogonal to each other.

"Each roll axis of a pair of rolling rolls of the upstream two-roll rolling mill is arranged to be inclined in directions opposite to each other with respect to the traveling direction of the material to be rolled. "The roll shafts of a pair of rolling rolls are arranged to be inclined in directions opposite to each other with respect to the traveling direction of the material to be rolled and in a direction opposite to that of the upstream two-roll rolling mill." For example, in the direction shown in FIG. 2A, the respective roll axes of the pair of rolling rolls are arranged in the direction opposite to the traveling direction of the material to be rolled. Each of the roll shafts of a pair of rolling rolls of the two-roll rolling mill is set in a direction opposite to the traveling direction of the material to be rolled, and
This means that the components are arranged obliquely in the direction shown in FIG.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have developed a two-roll rolling mill which has a feature that the structure is simple, the mill rigidity is high, and the biting is hard to occur, so that a large rolling reduction (area reduction rate) can be obtained. Various studies were conducted to realize "size-free rolling" using the machine group. As a result, the following matters became clear.

The final two rolling mills in the finishing rolling mill group are constituted by two two-roll rolling mills continuously arranged in a 90 ° phase, and any one of the last two rolling mills in the finishing rolling mill group is used. In addition, a roll having a hole shape in which the roll hole shape is a so-called “round shape” having a substantially circular shape (hereinafter, referred to as a round hole shape) (hereinafter, a roll having the round hole shape is referred to as a “round hole type roll”) is used. For example, by rolling at least a pair of rolling axes of a pair of rolling rolls of a two-roll rolling mill on the downstream side of the last two rolling mills are arranged obliquely with respect to the traveling direction of the material to be rolled. The "size-free rolling" can be realized by making the cross-sectional shape of the material substantially circular.

Here, the "round shape" of the roll hole shape means that the bottom of the hole shape except for the so-called "side relief portion" 3 represented by the angle .theta. It means that it is a hole-shaped shape having a perfect circular area consisting of a circular arc. In the normal case, the cross section of the side relief portion 3 is
It is often an arc whose radius is twice the radius r of the die bottom, or a straight line tangent to the circular arc of the radius r of the die bottom, and an angle θ representing the side relief portion 3 (hereinafter referred to as a side relief angle) Is often 10 to 45 °.

Next, a more detailed study was conducted and the following findings were obtained.

The projected shape in the traveling direction of the material to be rolled of the round roll hole type of the pair of rolling rolls is such that even if the gap between the rolling rolls is changed in order to reduce the finished dimensions, the rolling is performed in accordance with the gap change. By arranging the roll shaft obliquely, the roll shaft can be kept almost perfectly round.

FIG. 7 shows a projected shape of the roll-to-roll material in the traveling direction when the gap between the rolling rolls is changed using a round-hole type roll. As shown in FIG. 7A, in the case of the round hole type roll, when the radius r of the perfect circular area of the roll hole type is equal to 仕 上 げ of the finishing diameter d, the projected shape of the roll hole type is the side relief portion 3. Remove it to get a perfect circle. In this state, when the roll is rolled down to reduce the finishing diameter to h, that is, when the gap between the rolls is reduced and the distance between the groove bottoms of the roll is set to h, as shown in FIG. The roll hole projection shape is an elliptical shape. However, even when the distance between the groove bottoms of the roll is set to h by reducing the gap of the roll, FIG.
As shown in (2), when the roll axis is inclined, the projected shape of the roll hole type can be made closer to a perfect circle. FIG.
(C) shows a case in which a pair of roll axes are arranged to be inclined in opposite directions to each other. However, even when both of the pair of roll axes are arranged to be inclined in the same direction, the projected shape of the roll hole type is a perfect circle. Approach.

In the same manner as described above, in two two-roll rolling mills continuously arranged at a phase of 90 °, when each rolled roll form is a round form, the rolled form of the material to be rolled in the rolling direction is a round form. Even when the gap between the two rolling rolls is changed in order to reduce the finished dimensions, the projected shape can be maintained almost in a perfect circle by arranging the rolling roll shafts in accordance with the gap change.

FIG. 8 shows a case where two rolls of two rolls continuously arranged at a phase of 90 ° and the same shape of a round roll are used and the gap between the rolls is changed by the same amount. 3 shows a projected shape of a material to be rolled in a traveling direction. As shown in FIG. 8A, in a round hole type roll having the same shape, when the radius r of the perfect circular region of the roll hole type is equal to 仕 上 げ of the finishing diameter d in the rolling mill, each 1
The shape obtained by overlapping the roll hole projection shapes of each pair is a perfect circle. In this state, when the roll is rolled down to reduce the finished diameter to h, that is, when the gap between the rolls is reduced and the distance between the groove bottoms of the rolls in each two-roll rolling mill is set to h, FIG. As shown in ()), the projected shape of the roll hole type is substantially quadrangular. However, even when the gap between the roll grooves is reduced to h by reducing the gap of the roll, as shown in FIG. 8C, when the roll axis is inclined, the projected shape of the roll hole type becomes substantially a perfect circle. be able to.

In FIG. 8 (c), the roll axes of the upstream rolling mill are arranged in an inclined direction in mutually opposite directions, and the roll axes of the downstream rolling mill are also in opposite directions to each other and on the upstream side. Although the case where it was inclined and arranged in the opposite direction to the case of the rolling mill was shown,
(A) Both roll axes of the upstream rolling mill are both inclined in the same direction, and both roll axes of the downstream rolling mill are also inclined in the same direction. (B) Each roll of the upstream rolling mill The shafts are inclined in opposite directions to each other. Both roll axes of the downstream rolling mill are both inclined in the same direction. (C) Both roll axes of the upstream rolling mill are both inclined in the same direction. Similarly, in each case, the roll axes of the rolling mills on the side are inclined in opposite directions to each other, and similarly, the projected shape of the roll hole type approaches a perfect circle.

In two two-roll rolling mills continuously arranged at a 90 ° phase, when each roll form is a round form, the projected shape of the roll form of each roll in the advancing direction of the material to be rolled is used. When rolling into a substantially perfect circle, if the side relief angle θ is a small value of, for example, 30 ° or less,
The whole area in the circumferential direction of the material to be rolled can be accurately formed into a substantially perfect circle.

In the above case, if the side relief angle θ at the time of rolling with each roll is a small value of, for example, 25 ° or less, the whole area of the material to be rolled in the circumferential direction can be formed with higher accuracy.

In two two-roll rolling mills continuously arranged in a 90 ° phase, when each rolling roll die is a round die, when normal rolling is performed by an upstream two-roll rolling mill, When rolling without rolling the roll axes of a pair of rolling rolls, if the side relief angle θ is a small value of, for example, 30 ° or less, the roll axes of the pair of downstream rolling rolls are tilted and arranged. If the side relief angle θ at the time of rolling is set to a small value of, for example, 25 ° or less when the projected shape of the roll hole type material to be rolled in the traveling direction is set to a substantially perfect circle, the entire circumferential direction of the material to be rolled is It can be molded to almost a perfect circle with high accuracy.

The above findings are that, in two two-roll rolling mills continuously arranged at 90 ° phase, if the hole shape of the downstream rolling roll is round, that is, if the hole shape of the downstream roll is a round hole shape, the upstream roll is It has been found that this is almost true even when the hole shape of the rolling roll is an oval shape close to a round shape. For this reason, regarding the rolling mills that constitute the finishing rolling mill group, in the case where the hole shape of the upstream rolling roll of the final two two-roll rolling mills continuously arranged in a 90 ° phase is an oval shape close to a round shape. In this case, it is possible to realize "size-free rolling" by rolling at least each roll axis of a pair of rolling rolls of the two-roll rolling mill on the downstream side with respect to the traveling direction of the material to be rolled. it can.

The term "an oval shape close to a round shape" as used in the present invention means that the center of a circle forming a perfect circular portion at the bottom of a groove is as shown in the sectional view of FIG. Among the so-called "oval-shaped" hole types deviated by the distance δ from the position of the midpoint of the line connecting the deepest groove bottom of the roll, the relationship between δ and the distance h between the groove bottoms of the roll is 0 <(δ / h). <0.20.

The present invention has been completed based on the above findings.

Hereinafter, a method and an apparatus for manufacturing a metal material having a circular cross section according to the present invention will be described with reference to the drawings.

FIG. 1 is a diagram (a front view) for explaining a method for producing a metal material having a circular cross section according to the invention (1) and an apparatus for producing a metal material having a circular cross section according to the invention (4). It is. FIG. 1 (a) shows each of the roll shafts 4 of the pair of rolling rolls 1 of the downstream rolling mill Sn _{+ 2} among the final two two-roll rolling mills in the finishing rolling mill group 6, and the rolled material 2 FIG. 1B shows a case in which both are inclined and arranged in the same direction.

The material to be rolled 2 is a rolling mill group consisting of a plurality of rolling mills arranged continuously (hereinafter referred to as a preceding rolling mill group).
5, after the repetitive area-reducing rolling in step 5, the finishing rolling mill group 6 in which the two-roll rolling mills Sn _{+ 1} and _{Sn + 2} continuously arranged at 90 ° phase are the final two rolling mills A cross-sectional shape having a desired finishing diameter is finished to a circular metal material. The roll hole shape of the two-roll rolling mill S _{n + 1} is a round shape or an oval shape close to a round as described above, and the roll hole shape of the two-roll rolling mill S _{n + 2} is a round shape.

The last two rolling mills S in the rolling mill group 5 and the finishing rolling mill group 6 which constitute the above-mentioned preceding rolling mill group 5
_The rolling mills other than _{n + 1} and _{Sn + 2} are not particularly limited in the case of the invention of (1).

However, in the case of the invention (4), the rolling mills constituting the preceding rolling mill group 5 are a rolling mill group consisting of a plurality of two-roll rolling mills continuously arranged at 90 ° phase. Further, the final two rolling mills S in the finishing rolling mill group 6
_The rolling mills other than _{n + 1} and _{Sn + 2} are also two-roll rolling mills. The reason for this is that the two-roll rolling mill is characterized by its simple structure, low equipment cost, easy maintenance such as roll replacement and centering, and high mill rigidity.

In each of the inventions (1) and (4), the finishing rolling mill group 6 is different from the final two two-roll rolling mills Sn _{+ 1} and _{Sn + 2} . A rolling mill may not be included. That is, the finishing mill group 6 may be composed of only two two-roll mills Sn _{+ 1} and _{Sn + 2} .

The final two 2 in the finishing mill group 6
Among the rolling mills, the upstream rolling mill S _{n + 1} has a rolling adjustment mechanism (not shown) for the pair of rolling rolls 1, and the distance between the roll groove bottoms of the rolling mill S _{n + 1} is h (see FIG. 7) is set so as to be close to a target finish diameter (hereinafter, referred to as a sizing dimension). The set value is determined in consideration of the mill stiffness of the rolling mill S _{n + 1} and the breadth of the rolling by the rolling mill S _{n + 2} on the downstream side, which are obtained in advance through experiments and the like.

The downstream two-roll rolling mill S _{n + 2} has a rolling adjustment mechanism (not shown) for a pair of rolling rolls 1, and each roll shaft of the rolls 1 is moved in the traveling direction of the material 2 to be rolled. It has a mechanism (not shown) for arranging it in an inclined manner.
The rolling adjustment of the pair of rolling rolls 1 in the rolling mill Sn _{+ 2} is performed in consideration of the mill rigidity determined in advance by an experiment or the like.

As the mechanism for adjusting the rolling of the pair of rolling rolls 1 described above, for example, a mechanism using a rolling screw and an eccentric sleeve may be used.

The size-free area is a two-roll mill S _{n + 2}
Can be set to a range of not more than twice the radius rn _{+ 2} of the perfect circular region of the roll hole type. As already described with reference to FIG.
When the sizing dimension is equal to twice the radius r _{n + 2} of the perfect circular region of the roll hole shape of the rolling mill S _{n + 2} , when the inclination angle of the roll axis is 0 °, the rolled material is viewed from the traveling direction of the rolled material. The projection shape of the roll hole type becomes a perfect circle except for the side relief portion 3.
When the sizing dimension is reduced by narrowing the gap of the roll, as shown in FIG. 9, the roll shaft is arranged at an appropriate angle to arrange the roll hole type projection shape to a substantially perfect circle except for the side relief portion. Can be The shape of the free surface portion 7 in rolling by the rolling mill S _{n + 2} is determined by the shape of the roll hole of the two-roll rolling mill S _{n + 1} . Therefore, in order to reduce the polarization diameter difference, in the case of using a round grooved rolls in rolling mill S _{n + 1,} the radius r _{n + 1} of the perfect circular area of the roll caliber of the rolling mill S _{n + 1} rolling Machine S
_{n + 2} of radius r _{n + 2} near the perfect circular area of the roll caliber, for example, it is desirable to set the _{0.95r n + 2 ≦ r n +} 1 ≦ 1.05r n + 2. Further, the rolling mill S _{n +} in the case of using a roll caliber of the roll near oval shape round the _1, rolling mill S _{n +1} of perfect circular area of the roll caliber radius r _{n + 1}
Is set near the radius rn _{+ 2} of the perfect circular area of the roll hole type of the rolling mill S _{n + 2} , for example, 0.95rn _{+ 2} ≦ rn _{+ 1} ≦ 1.05rn _{+ 2} . 18 (δ / h)
Is desirably set to a small value, for example, 0 <(δ / h) <0.10.

The final two 2 in the finishing mill group 6
In order to arrange the roll shafts 4 of the pair of rolling rolls 1 of the downstream two-roll rolling mill S _{n + 2} among the roll rolling mills with respect to the traveling direction of the material 2 to be rolled, for example, as shown in FIG. There are methods shown in FIG. 1A and FIG. Further, the tilted arrangement may be performed by a method shown in FIG. 4 having a different direction from that of FIG. FIG.
(A) and FIG. 4 (a) show one of the two-roll mill S _{n + 2} .
In the case where the roll shafts 4 of the pair of rolling rolls 1 are arranged obliquely in directions opposite to each other with respect to the traveling direction of the material 2 to be rolled,
1 (b) and 4 (b) show a case where both are inclined and arranged in the same direction. It should be noted that FIG.
1, (b) -1 is a front view, (a) -2, (b) -2 is a plan view.

As will be described in detail in the following embodiments, as the roll reduction increases, that is, as the roll gap becomes narrower and the sizing dimension becomes smaller, the roll shaft tilt angle φ (for example, see FIG. 4). ) Needs to be set to a large value, but the φ may be set in the range of 0 to 8 ° in order not to generate flaws in the material to be rolled. In addition, as illustrated in FIG.
Each roll shaft 4 of a pair of _{n + 2} rolling rolls 1 is
In any case, the inclination angle φ for each roll needs to be the same value in the case where the rolls are inclined in opposite directions to each other or in the case where both are inclined in the same direction.

As a mechanism for arranging the roll shafts 4 of the pair of rolling rolls 1 of the two-roll rolling mill S _{n + 2} with respect to the traveling direction of the material 2 to be rolled, for example, a jack, which is a conventional means, is used. A mechanism or a hydraulic mechanism may be used.

FIG. 2 is a diagram illustrating a method for manufacturing a metal material having a circular cross section according to the invention (2) and an apparatus for manufacturing a metal material having a circular cross section according to the invention (5). FIG.
(A) shows, among the final two rolling mills in the finishing rolling mill group, each roll shaft 4 of a pair of rolling rolls 1 of an upstream two-roll rolling mill Sn _{+ 1} is moved in the traveling direction of the material 2 to be rolled. And the roll shafts 4 of the pair of rolling rolls 1 of the two-roll rolling mill Sn _{+ 2} on the downstream side are moved with respect to the traveling direction of the material 2 to be rolled. FIG. 7 is a diagram showing one method of arranging in a direction opposite to that of the two-roll rolling mill Sn _{+ 1} on the upstream side and in a direction opposite to that of the upstream two-roll rolling mill Sn _{+ 1} . FIG. 2B and FIG.
(C), the roll shafts 4 of the pair of rolling rolls 1 of the two-roll rolling mill Sn _{+ 1} on the upstream side are arranged obliquely in directions opposite to each other with respect to the traveling direction of the material 2 to be rolled. Each roll shaft 4 of the pair of rolling rolls 1 of the downstream two-roll rolling mill Sn _{+ 2} is
This is an example of a case in which both are arranged in the same direction with respect to the traveling direction of the material 2 to be rolled.

It should be noted that (a) -1, (b) -1, and
(C) is a front view, and (a) -2 and (b) -2 are plan views.

FIG. 3 is a diagram illustrating a method for manufacturing a metal material having a circular cross section according to the invention (3) and an apparatus for manufacturing a metal material having a circular cross section according to the invention (6). FIG.
(A) and FIG. 3 (b) show the final 2 in the finishing mill group.
Of the two rolling mills on the upstream side, one of the two rolling mills Sn ₊ 1
The roll shafts 4 of the pair of rolling rolls 1 are both inclined in the same direction with respect to the traveling direction of the material 2 to be rolled, and furthermore, a pair of rolling rolls 1 of a downstream two-roll rolling mill S _{n + 2} are arranged. In this example, both roll shafts 4 are inclined in the same direction with respect to the traveling direction of the material 2 to be rolled. FIG.
(C) and FIG. 3 (d) show two-roll rolling mill S _{n + 1} on the upstream side.
Each of the roll shafts 4 of the pair of rolling rolls 1 is disposed so as to be inclined in the same direction with respect to the traveling direction of the material 2 to be rolled.
This is an example in which the respective roll shafts 4 of a pair of rolling rolls 1 of a two-roll rolling mill Sn _{+ 2} on the downstream side are arranged obliquely in directions opposite to each other with respect to the traveling direction of the material 2 to be rolled. .

It should be noted that (a) -1, (b), and (c) of FIG.
-1 and (d) are front views, and (a) -2 and (c) -2 are plan views.

The material to be rolled 2 is subjected to repeated area-reducing rolling at the preceding rolling mill group 5 and then finally passed through two roll rolling mills S _{n + 1} and S _{n + 2} continuously arranged at 90 ° phase. In the finishing rolling mill group 6 as the two rolling mills described above, the cross-sectional shape having a desired finishing diameter is finished to a circular metal material. The roll hole shape of the two-roll rolling mill S _{n + 1} has a round shape or an oval shape close to a round, and the roll hole shape of the two-roll rolling mill S _{n + 2} has a round shape.

The last two rolling mills S in the rolling mill group 5 and the finishing rolling mill group 6 which constitute the above-mentioned preceding rolling mill group 5
_The rolling mill excluding _{n + 1} and _{Sn + 2} is the invention of (2) and (3)
In the case of the invention of (1), there is no particular limitation.

However, in the case of the inventions of (5) and (6), the rolling mills constituting the preceding rolling mill group 5 are a rolling mill composed of a plurality of two-roll rolling mills continuously arranged at 90 ° phase. Group of aircraft. Further, the rolling mills other than the final two rolling mills Sn _{+ 1} and _{Sn + 2} in the finishing rolling mill group 6 are also two-roll rolling mills. The reason for this is that, as in the case of the invention (4) described above, the two-roll rolling mill has a simple structure, low equipment costs, easy maintenance such as roll replacement and centering, and mill rigidity. Is large.

The invention of (2), the invention of (3),
In either case of the invention of (5) and the invention of (6), the finishing rolling mill group 6 is the last two two-roll rolling mills S described above.
A rolling mill other than _{n + 1} and _{Sn + 2} may not be included. That is, the finishing mill group 6 may be composed of only two two-roll mills Sn _{+ 1} and _{Sn + 2} .

Free surface portion 7 in rolling by rolling mill S _{n + 2}
Is determined by the shape of the roll hole shape of the two-roll rolling mill Sn _{+ 1} . Therefore, not only each roll shaft 4 of the pair of rolling rolls 1 of the rolling mill S _{n + 2} but also the rolling mill S
Even in the case of _{n + 1} , if the roll shafts 4 of the pair of rolling rolls 1 are arranged so as to be inclined with respect to the traveling direction of the material 2 to be rolled, one of the rolling mills S _{n + 2} Twin rolls 1
In comparison with the case where only each of the roll shafts 4 is inclined, the difference in diameter deviation of a metal material having a circular cross section can be further reduced.

For this reason, the last two rolling mills S _{n + 1} and _{Sn + 2} in the finishing rolling mill group 6 each have a pair of rolling reduction mechanisms (not shown) for the rolling rolls 1. It is assumed that a mechanism (not shown) for arranging each roll shaft 4 of the roll 1 at an angle to the traveling direction of the material 2 to be rolled is provided.

The setting of the distance h between the bottoms of the roll grooves of the upstream rolling mill S _{n + 1} , that is, the adjustment of the rolling reduction, is performed by the mill rigidity of the two-roll rolling mill S _{n + 1} and the downstream May be determined in consideration of the breadth of the rolling by the rolling mill Sn _{+ 2} . Further, the rolling reduction of the pair of rolling rolls 1 in the rolling mill Sn _{+ 2} may be performed in consideration of the mill stiffness determined in advance by experiments or the like.

It should be noted that a mechanism using, for example, a screw and an eccentric sleeve may be used as the rolling adjustment mechanism of the pair of rolling rolls 1 of the rolling mills S _{n + 1} and S _{n + 2} .

When the sizing dimension is equal to the radius r _{n + 2} of the perfect circular area of the roll hole type of the downstream two-roll rolling mill S _{n + 2} of the last two rolling mills in the finishing rolling mill group 6. If the radii rn _{+ 1} and rn _{+ 2} of the perfect circular area of the roll hole type of the two-roll rolling mill S _{n + 1} on the upstream side are set to be the same, FIG. As described above, the projected shape of the roll-to-roll material of the rolling mill S _{n + 1} and the rolling mill S _{n + 2} viewed from the traveling direction can be made a perfect circle. When the sizing dimension is reduced by narrowing the gap of the roll, the projected shape of the roll hole type viewed from the traveling direction of the material to be rolled is shown in FIG.
As shown in (b), it becomes almost quadrangular. However, as shown in FIG. 8 (c), by arranging each roll axis of a pair of rolling rolls of the rolling mill Sn _{+ 1} and the rolling mill Sn _{+ 2} at an angle, the projected shape of the roll-hole type is reduced. It can be close to a perfect circle.

The roll shafts 4 of the pair of rolling rolls 1 of the final two rolling mills S _{n + 1} and S _{n + 2 in} the finishing rolling mill group 6 are inclined with respect to the traveling direction of the material 2 to be rolled. The arrangement may be performed according to the method shown in FIGS.

Hereinafter, the present invention will be described in more detail with reference to examples.

[0062]

【Example】

(Example 1) The eccentricity difference when rolling by the methods of the prior art 1 and the prior art 2 using a hole-shaped roll based on a finishing diameter of 25 mm was geometrically determined. That is, it is assumed that the finished shape (product shape) is determined by the projected shape of the roll-hole type material to be rolled in the traveling direction without considering the width spread, and the bias in the case of rolling by the methods of the related art 1 and the related art 2 is assumed. The diameter difference was determined. The result is shown in FIG. In the case of rolling by the method of the prior art 1, the deviation difference becomes a line indicated by L1 in FIG. In the prior art 2 “method of rolling and shaping with a two-roll mill and two stands for finishing from four directions inclined at 45 ° with respect to the rolling direction of the two-roll mill group”, the eccentricity difference is represented by a line indicated by L2 in FIG. Although it changes with the product diameter, the diameter deviation difference can be reduced to 1/4 as compared with the method of the prior art 1 described above.

Next, the difference in eccentricity in the case of rolling by the method of the invention (1) was geometrically determined using a grooved roll having a finishing diameter of 25 mm as a reference. Table 1 shows details of the shape of each round hole type roll at this time. The roll diameter in Table 1 refers to the diameter at the bottom of the roll groove. In addition,
In this case, of the final two rolling mills in the finishing rolling mill group, each roll axis of a pair of rolling rolls of the downstream two-roll rolling mill Sn _{+ 2} is moved with respect to the traveling direction of the material to be rolled. The geometrically determined eccentricity difference is the same whether or not both are inclined in the opposite direction or both are inclined in the same direction.

[0064]

[Table 1]

In the method of the present invention (1), the inclination angle φ of the roll shaft needs to be set larger as the rolling reduction is increased, that is, as the roll gap is narrowed and the sizing dimension is reduced. When the inclination angle at which the geometric deviation difference is minimized (hereinafter referred to as an appropriate inclination angle) is obtained, a line indicated by AP1 in FIG. 13 is obtained. When the deviation difference when this proper inclination angle is used is geometrically obtained for each finishing diameter, a line indicated by LP1 in FIG. 11 is obtained.

The line indicated by LP1 is indicated by L in FIG.
Compared with the line indicated by 1, according to the invention of (1),
It is clear that in the range of 0.92d to d, the eccentricity difference can be suppressed to 3/16 of the case of rolling by the method of the prior art 1. Similarly, the line indicated by LP1 is indicated by L in FIG.
Compared with the line indicated by 2, according to the invention of (1),
It is clear that in the range of 0.92d to d, the eccentricity difference can be suppressed to 3/4 of the case of rolling by the method of the prior art 2. As a result, according to the invention of (1), it is understood that the size-free region is 1.3 times or more as wide as that of the conventional “size-free rolling” technology, especially the conventional technology 2.

Next, a JIS S45C billet produced by smelting and bulk rolling by a usual method is rolled by a group of rolling mills in the former stage by a usual method, and then each round hole die shown in Table 1 is obtained. Two-roll rolling mills Sn _{+ 1} and _{Sn + 2} with rolls
Using the method according to the invention of (1),
Finish rolling was performed to 25 mm, and the deviation in diameter was measured.

Of the last two rolling mills in the finishing rolling mill group, the respective roll axes of a pair of rolling rolls of the downstream two-roll rolling mill S _{n + 2} are mutually moved with respect to the traveling direction of the material to be rolled. Fig. 1 shows the difference in eccentricity when rolling was performed with the sheet inclined in the opposite direction
This is shown as RP1a in 1. FIG. 11 shows the difference in eccentricity in the case where each roll axis of a pair of rolling rolls of the rolling mill Sn _{+ 2} is rolled while being inclined in the same direction with respect to the traveling direction of the material to be rolled. Shown as RP1b.

According to FIG. 11, the eccentricity difference (RP1a, RP1b) when rolling by the actual machine is slightly larger than the eccentricity difference (LP1) obtained geometrically. However, rolling mill S _{n + 2}
(RP1a) when the roll axes of the pair of rolling rolls are inclined in directions opposite to each other with respect to the traveling direction of the material to be rolled.
And when both are inclinedly arranged in the same direction (RP1b)
There is hardly any difference in the eccentricity difference. According to the method (1), the size-free area is 1.5 mm or more with respect to the eccentricity difference of 0.1 mm or less.

(Example 2) Two rolls on the upstream side of the last two rolling mills in the finishing rolling mill group in the invention of (2), using a hole-shaped roll based on a finishing diameter of 25 mm. Each roll axis of a pair of rolling rolls of the rolling mill S _{n + 1} is arranged in an inclined direction in a direction opposite to the traveling direction of the material to be rolled,
Further, the respective roll axes of the pair of rolling rolls of the downstream two-roll rolling mill S _{n + 2} are set in directions opposite to each other with respect to the advancing direction of the material to be rolled and the upstream rolling mill S _{n + 1} (Hereinafter referred to as rolling method), and in the invention of (3), the upstream side of the last two rolling mills in the finishing rolling mill group in the invention of (3). 2 each roll axes of the rolling rolls of a pair of rolling mill S _{n + 1} is arranged obliquely in the same direction both to the traveling direction of the material to be rolled, further, two-roll mill for downstream S _{n +} each roll axis of the rolling rolls ₂ of a pair, the method (hereinafter referred to as the rolling method) for finish rolling inclined disposed in the same direction both to the traveling direction of the material to be rolled, the two cases for the Hen径Differences were determined geometrically.

Table 2 shows details of the shape of each round hole type roll at this time. The roll diameter in Table 2 also indicates the diameter at the bottom of the roll groove. Note that, when the finish rolling is performed by the two rolling methods described above and above, the geometrically determined eccentric differences are equal.

[0072]

[Table 2]

Also in the case of the above-mentioned rolling method and rolling method, as the rolling reduction is increased, that is, as the roll gap is narrowed and the sizing dimension is reduced,
It is necessary to set the inclination angle φ to be large. Then, when an appropriate inclination angle at which the geometric deviation difference is minimized is obtained, FIG.
Inside, a line indicated by AP2 is obtained. In the method described above, since the roll hole shape of the two-roll mills S _{n + 1} and S _{n + 2} is the same, the roll axis for making the projected shape of the roll hole shape almost a perfect circle is used. The appropriate inclination angle of the rolling mill S
_The same value is obtained for _{n + 1} and _{Sn + 2} , that is, a line indicated by AP2. When the diameter deviation difference when this proper inclination angle is used is geometrically obtained for each finishing diameter, a line indicated by LP2 in FIG. 12 is obtained.

The line indicated by LP2 is indicated by L1 in FIG.
It is clear from the comparison with the line shown by the above that the eccentricity difference can be suppressed to 1/60 of the case of rolling by the method of the prior art 1 by the above-mentioned rolling method or the rolling method. Similarly, when the line indicated by LP2 is compared with the line indicated by L2 in FIG.
It can be seen that it can be suppressed.

Next, a JIS S45C billet produced by smelting and slab rolling by a usual method is rolled by a conventional rolling mill group by a usual method, and then each round hole die shown in Table 2 is obtained. Two-roll rolling mills Sn _{+ 1} and _{Sn + 2} with rolls
And finished rolling to a finished diameter (product diameter) of 22 to 25 mm by the above-described rolling method and the rolling method, and the deviation in diameter was measured.

The eccentricity difference when rolled by the above-mentioned rolling method is shown as RP2 in FIG. In addition, the difference in diameter in the case of rolling by the above-mentioned rolling method is shown as RP3 in FIG. According to FIG. 12, the eccentricity difference (RP2, RP3) in the case of rolling by an actual machine is calculated by the eccentricity difference (LP
A little larger than 2). However, there is almost no difference in the diameter difference between the above-described rolling method (RP2) and the rolling method (RP3).

Further, according to the above-mentioned rolling method and the rolling method from FIG. 12, the deviation in diameter in the range of all product diameters (finished diameters) of 25 to 22 mm is 0.05 mm (50 μm).
m), it is clear that the size-free area becomes extremely large. Further, from FIG. 12, in the case of the above-described rolling method or the rolling method, it is assumed that the size-free region is not restricted by the deviation in diameter, but is restricted by the setting of the inclination angle φ of the roll axis.

In order to make the projected shape of the roll hole type substantially circular, it is necessary to set the inclination angle φ of the roll axis to be larger as the sizing dimension becomes smaller. However, when the inclination angle φ of the roll shaft is set to be large, the contact area 8 between the roll and the material to be rolled at the bottom of the roll groove expands obliquely as shown in FIG. 15, so that the material to be rolled may have flaws.

Therefore, in order to determine the inclination angle φ of the roll axis which does not cause a flaw in the material to be rolled, a JIS S45C billet produced by smelting and sizing and rolling by a usual method is subjected to a pre-process by a usual method. After rolling in a group of rolling mills, by using the two-roll rolling mills Sn _{+ 1} and _{Sn + 2} having each round hole type roll shown in Table 2 above, the rolling method of the roll shaft Finish rolling was performed while changing the inclination angle φ in the range of 0 to 10 °, and the presence or absence of flaws on the surface of the material to be rolled was visually observed. As a result, it was found that the inclination angle φ of the roll axis at which no flaw was generated on the material to be rolled was a maximum of 8 °.

FIG. 14 shows that the appropriate inclination angle in the case of finish rolling by the above-mentioned rolling method and the rolling method is 0-10.
FIG. 9 is a diagram showing a relationship between an appropriate inclination angle and a finished diameter (product diameter) when changed in the range of ゜. As described above, the maximum inclination angle at which no flaw occurs in the material to be rolled is 8 °.
4 and FIG. 12, the size-free area in the above-mentioned rolling method or the rolling method is extremely large, that is, 3 mm or more with respect to the reference finishing diameter of 25 mm, even when the deviation diameter is less than 0.05 mm. be able to.

(Example 3) A JIS S45C billet produced by smelting and bulk rolling by a usual method was rolled by a group of rolling mills in the former stage by a usual method, and then each round shown in Table 3 was obtained. The two-roll rolling mills S _{n + 1} and S _{n + 2} having the grooved rolls are used, and among the final two rolling mills in the finishing rolling mill group in the invention of (1), the rolling mill on the downstream side For the method of finishing and rolling by rolling each roll axis of a pair of rolls of Sn _{+ 2} in directions opposite to each other with respect to the traveling direction of the material to be rolled, the side relief portion has a difference in diameter. The effects were investigated. That is, the roll form of the rolling mill S _{n + 1} is fixed, the side relief angle in the roll form of the rolling mill S _{n + 2} is changed in the range of 5 to 40 °, the sizing dimension is set to 23 mm, and the finish rolling is performed. Then, the diameter difference was measured.

[0082]

[Table 3]

FIG. 16 shows the measurement results of the deviation in diameter. It can be seen from FIG. 16 that when the side relief angle θ exceeds 30 °, the deviation in diameter increases sharply. Therefore, (1)
When the "size-free rolling" is performed by the method described above, the side relief angle θ of the rolling roll of the rolling mill Sn _{+ 2} is desirably 30 ° or less. The side relief angle θ is 2
More preferably, it is set to 5 ° or less.

[0084]

According to the production method of the present invention, it is possible to perform practical size-free rolling using a two-roll rolling mill, which has a substantially perfect finished cross-sectional shape, a small diameter difference, and a wide size-free region. it can. For this reason, the number of rolls held can be reduced, and the roll change can be omitted, so that the rolling operation efficiency can be greatly increased. Furthermore, the rolling mill group of the manufacturing apparatus of the present invention is constituted by a two-roll rolling mill, and has excellent advantages such as simple structure, easy maintenance such as roll replacement and centering, and high mill rigidity. Things.

[Brief description of the drawings]

FIG. 1 is a front view illustrating a rolling method according to the present invention. (A) is a case where each roll axis of a pair of rolling rolls of a rolling mill on the downstream side of the finishing rolling mill group is arranged to be inclined in directions opposite to each other with respect to the traveling direction of the material to be rolled; A case is shown in which each of the above-mentioned roll shafts is inclined and disposed in the same direction with respect to the traveling direction of the material to be rolled.

FIG. 2 is another diagram illustrating a rolling method according to the present invention. (A), the roll axes of a pair of rolling rolls of a rolling mill on the upstream side of the finishing rolling mill group are arranged obliquely in directions opposite to each other with respect to the traveling direction of the material to be rolled; (A) shows a case in which each roll axis of a pair of rolling rolls of a rolling mill is inclined in a direction opposite to the traveling direction of the material to be rolled and in a direction opposite to that of the rolling mill on the upstream side; ) -1 is a front view, and (a) -2 is a plan view. (B), the respective roll axes of the upstream rolling mill are arranged obliquely in directions opposite to each other with respect to the traveling direction of the material to be rolled. The case where both are arranged in the same direction with respect to the traveling direction is shown, (b) -1 is a front view,
(B) -2 is a plan view. (C), the respective roll axes of the upstream rolling mill are arranged obliquely in directions opposite to each other with respect to the traveling direction of the material to be rolled. It is another front view which shows the case where both are inclinedly arranged in the same direction with respect to the traveling direction.

FIG. 3 is yet another view illustrating the rolling method according to the present invention. (A), the roll axes of a pair of rolling rolls of the upstream rolling mill are both arranged in the same direction with respect to the advancing direction of the material to be rolled, and further, a pair of downstream rolling mills are arranged. (A) -1 shows a case where both roll axes of a rolling roll are inclined in the same direction with respect to the traveling direction of the material to be rolled;
Is a front view, and (a) -2 is a plan view. (B), the respective roll axes of a pair of rolling rolls of the upstream rolling mill are both arranged in the same direction with respect to the traveling direction of the material to be rolled, and further, the pair of rolling mills of the downstream rolling mill are further arranged. It is another front view which shows the case where each roll axis | shaft of a roll is both inclinedly arrange | positioned in the same direction with respect to the advancing direction of a to-be-rolled material. (C), each roll axis of the upstream rolling mill is arranged in an inclined manner in the same direction with respect to the traveling direction of the material to be rolled, and further, each roll axis of the downstream rolling mill is set to FIG. 3C shows a case where the components are inclined in directions opposite to each other with respect to the traveling direction, wherein FIG. 1C is a front view and FIG. 2C is a plan view. (D), the roll axes of the upstream rolling mill are both arranged in the same direction with respect to the traveling direction of the material to be rolled, and further, the roll axes of the downstream rolling mill are set to It is another front view which shows the case where it arrange | positions in the mutually opposite direction with respect to the traveling direction. .

FIG. 4 is another explanatory view of a method of arranging each roll axis of a pair of rolling rolls of a rolling mill on the downstream side of a finishing rolling mill group with respect to a traveling direction of a material to be rolled. (A) shows the case where each roll axis of the downstream rolling mill is arranged to be inclined in mutually opposite directions with respect to the traveling direction of the material to be rolled, (a) -1 is a front view, and (a)- 2 is a plan view. (B) shows a case where both the roll shafts are arranged in the same direction with respect to the traveling direction of the material to be rolled, (b) -1 is a front view,
(B) -2 is a plan view.

FIG. 5 is a diagram showing a cross-sectional shape of a product obtained by size-free rolling by a conventional method.

FIG. 6 is a diagram showing a cross-sectional shape of a product obtained by size-free rolling by another conventional method.

FIG. 7 is a diagram showing a projected shape of a roll-to-roll material to be rolled in the traveling direction when the gap between the rolling rolls is changed using a round-hole type roll. (A) is a projected shape when the radius r of the perfect circular area of the roll hole type is equal to 仕 上 げ of the finished diameter d, and (b) is to reduce the gap of the roll and set the distance between the groove bottoms of the roll to h. (C) is a roll hole projection shape when the roll axes are inclined in opposite directions when the roll gap is reduced.

FIG. 8 shows a roll-to-roll type rolled material when two rolls of the same shape are used and the gap between the rolls is changed by the same amount in two two-roll rolling mills arranged in a 90 ° phase. It is a figure which shows the projection shape of a traveling direction.
(A) shows the case where the radius r of the roll hole type perfect circle area is the finishing diameter d.
(B) is the projected shape of the roll hole type when the gap between the rolls is reduced and the distance between the groove bottoms of the rolls in each rolling mill is set to h, (b).
Is a roll-hole type projected shape when the roll axis is inclined to reduce the roll gap.

FIG. 9: When the radius r of the perfect circular area of the roll hole type is equal to 仕 上 げ of the finishing diameter d, the roll axis is arranged obliquely, and the projected shape of the roll hole type material to be rolled in the traveling direction is substantially true. It is a figure explaining the state made into a circle.

FIG. 10 is a view showing a relationship between a product diameter (finished diameter) when rolled by a conventional size-free rolling method and a geometrically obtained deviation diameter difference.

FIG. 11 is a diagram showing a relationship between a product diameter (finished diameter) and a deviation diameter when rolled by the method according to the present invention.

FIG. 12 is a view showing a relationship between a product diameter and a deviation diameter when rolled by another method according to the present invention.

FIG. 13 is a diagram illustrating a relationship between a product diameter (finished diameter) and an appropriate inclination angle when rolled by the method according to the present invention.

FIG. 14 is another diagram illustrating a relationship between a product diameter (finished diameter) and an appropriate inclination angle when rolled by the method according to the present invention.

FIG. 15 is a diagram showing a contact area between a roll and a material to be rolled at the bottom of the roll groove.

FIG. 16 shows that the roll hole shape of the upstream rolling mill of the finishing mill group is constant, and the side relief angle of the roll hole shape of the downstream rolling mill is changed in the range of 5 to 40 ° to reduce the sizing dimension to 23 mm. It is a figure which shows the deviation diameter when setting and finishing rolling.

FIG. 17 is a cross-sectional view of a “round shape” roll hole type.

FIG. 18 is a cross-sectional view of a roll hole type “oval shape close to a round shape”.

[Explanation of symbols]

1: Roll roll 2: Rolled material 3: Side relief portion 4: Roll shaft 5: Pre-stage rolling mill group 6: Finish rolling mill group 7: Free surface portion 8: Contact area between roll and rolled material θ: Side Relief angle φ: Roll shaft inclination angle d: Finish diameter h: Distance between roll groove bottoms S _{n + 1} : Upstream finish rolling mill S _{n + 2} : Downstream finish rolling mill

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Masayuki Yamada 4-5-33 Kitahama, Chuo-ku, Osaka City, Osaka Sumitomo Metal Industries, Ltd.

Claims (6)

[Claims] 1. A metal material having a circular cross section in a group of a plurality of continuous rolling mills, wherein two two-roll rolling mills continuously arranged at 90 ° phase are the last two rolling mills in a finishing rolling mill group. In the method of manufacturing, the roll axis of a pair of rolling rolls of a two-roll rolling mill downstream of the final two rolling mills in the finishing mill group, with respect to the traveling direction of the material to be rolled, A method for producing a metal material having a circular cross-sectional shape, characterized in that finish rolling is carried out by arranging them in mutually opposite directions or by arranging them both in the same direction. 2. A metal material having a circular cross-sectional shape in a group of a plurality of continuous rolling mills, wherein two two-roll rolling mills continuously arranged at 90 ° phase are the last two rolling mills in a finishing rolling mill group. Wherein the roll shafts of a pair of rolling rolls of a two-roll rolling mill on the upstream side of the last two rolling mills in the finishing mill group are mutually moved with respect to the traveling direction of the material to be rolled. And the roll shafts of a pair of rolling rolls of the downstream two-roll rolling mill are arranged in opposite directions to the traveling direction of the material to be rolled, and the two rolls on the upstream side. Manufacture of a metal material having a circular cross-sectional shape characterized by being arranged in a direction opposite to the direction of the rolling mill or being finished in an inclined direction in both directions with respect to the traveling direction of the material to be rolled. Method. 3. A metal material having a circular cross section in a group of a plurality of continuous rolling mills in which two two-roll rolling mills continuously arranged at 90 ° phase are the last two rolling mills in a finishing rolling mill group. Wherein the roll shafts of a pair of rolling rolls of a two-roll rolling mill on the upstream side of the last two rolling mills in the finishing mill group are both set with respect to the traveling direction of the material to be rolled. And the roll shafts of a pair of rolling rolls of a two-roll rolling mill on the downstream side are both inclined and arranged in the same direction with respect to the traveling direction of the material to be rolled. A method for producing a metal material having a circular cross-sectional shape, wherein the material is finish-rolled while being arranged in a direction opposite to the traveling direction of the material. 4. A rolling mill group comprising a plurality of two-roll rolling mills continuously arranged at 90 ° phase, and two or more two-roll rolling mills continuously arranged at 90 ° phase downstream of said rolling mill group. And a finishing rolling mill group consisting of rolling mills for manufacturing a metal material having a circular cross-section, wherein each of the final two rolling mills in the finishing rolling mill group has a roll reduction adjustment. And a downstream two-roll rolling mill among the final two rolling mills has a roll axis tilt arrangement mechanism, and each roll axis of a pair of rolling rolls of the rolling mill is a roll material of a rolled material. An apparatus for manufacturing a metal material having a circular cross-sectional shape, wherein the metal member is arranged to be inclined in directions opposite to each other with respect to the traveling direction or both are arranged to be inclined in the same direction. 5. A rolling mill group comprising a plurality of two-roll rolling mills continuously arranged at 90 ° phase, and two or more two-roll rolling mills continuously arranged at 90 ° phase downstream of said rolling mill group. And a finishing rolling mill group consisting of rolling mills for manufacturing a metal material having a circular cross-section, wherein each of the final two rolling mills in the finishing rolling mill group has a roll reduction adjustment. Mechanism and a roll axis inclined arrangement mechanism, wherein the roll axes of a pair of rolling rolls of the upstream two-roll rolling mill of the final two rolling mills are opposite to each other with respect to the traveling direction of the material to be rolled. And the roll axes of a pair of rolling rolls of the downstream two-roll rolling mill are opposite to each other with respect to the advancing direction of the material to be rolled, and the upstream two-roll rolling mill is Inclined arrangement in the opposite direction to the case of, or
An apparatus for manufacturing a metal material having a circular cross-sectional shape, wherein both are arranged obliquely in the same direction with respect to the traveling direction of the material to be rolled. 6. A rolling mill group comprising a plurality of two-roll rolling mills continuously arranged in a 90 ° phase, and two or more two-roll rolling mills continuously arranged in a 90 ° phase downstream of said rolling mill group. And a finishing rolling mill group consisting of rolling mills for manufacturing a metal material having a circular cross-section, wherein each of the final two rolling mills in the finishing rolling mill group has a roll reduction adjustment. Mechanism and a roll axis inclined arrangement mechanism, wherein each of the roll axes of a pair of rolling rolls of the upstream two-roll rolling mill of the final two rolling mills are both the same with respect to the traveling direction of the material to be rolled. And the downstream side 2
Each roll axis of a pair of rolling rolls of a roll rolling machine is disposed inclining in the same direction with respect to the traveling direction of the material to be rolled,
Alternatively, an apparatus for manufacturing a metal material having a circular cross-sectional shape, wherein the metal material is inclined and disposed in a direction opposite to a traveling direction of a material to be rolled.