JPH11740A - Manufacture of bar of dissimilar section - Google Patents

Abstract

PROBLEM TO BE SOLVED: To unify the thickness distribution, to improve the workability and productivity, and to prevent the torsional deformation or the corrugated deformation of a plate, i.e., to prevent the edge drop. SOLUTION: A plurality of pairs of rolling rolls 20, 30, 40 having approximately columnar roll bodies 21, 31, 41 are provided, at least one projecting part 22, 32, 42 to be respectively extended approximately over the whole circumference and projected from the roll bodies 20, 30, 40 are formed on at least one of the rolling rolls 20, 30, 40, arcshaped surfaces 22a, 32a, 42a of revolution approximately around the axis of revolution of the rolling rolls are formed on the projecting parts, the radius of curvature of the projecting parts 22, 32, 42 formed on the rolling roll of each stage is set to be gradually larger toward the downstream stage in the moving direction of a plate A, and a thick plate part of dissimilar sectioned bar B is rolled by at least a part of the roll body while a thin plate part of the dissimilar sectioned bar B is rolled between the projecting part of the rolling roll and other rolling roll.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a so-called irregularly shaped strip, that is, a strip having portions having different thicknesses in the width direction of the strip continuously in the longitudinal direction.

[0002]

2. Description of the Related Art Some of such irregularly shaped cross sections are formed of conductive copper, copper alloy, or the like, and are used as lead frame materials for transistors and connector materials.

[0003] As a method of manufacturing such a deformed cross-section strip, there is a method of manufacturing by cutting the surface of a plate material, or a method of pressing a roll having a V-shaped projection against the plate material to perform plastic working.

[0004] In such a conventional method of manufacturing a profiled cross section,
In the case of cutting, unnecessary cutting chips are generated, resulting in large material loss and increased cost. In the case of rolls having V-shaped projections, the pressing force is generated by the reciprocating motion of each roll. In addition, it has to be intermittent, the processing speed cannot be increased, and the productivity cannot be improved.

To solve such a problem, a manufacturing method as shown in FIG. 6 or FIG. 7 can be considered.

In the manufacturing method shown in FIG. 6, a rolling step using a roll having a circumferential groove and a flattening step using an outer cylindrical roll are repeated to manufacture a deformed cross section having a predetermined size. Things. That is, as shown in FIG. 6A, a columnar roll 1 in which a circumferential groove 1a is formed,
When the plate material A is sandwiched and rolled between the cylindrical roll 2 having a flat outer surface, the side edges of the plate material A become both edges 1 of the circumferential groove 1a.
b and a thin plate portion A having a deformed cross section which is rolled between rolls 2
1 is formed, and the central portion of the plate material A curves and enters the peripheral groove 1a to form a thick plate portion A2 having an irregular cross section. Next, as shown in FIG. 6B, the thick plate portion A2 curved by the cylindrical rolls 3 and 4 having a smooth outer surface is formed flat. To further increase the width of the thin plate portion A1, FIG.
The sheet material A is sandwiched between a cylindrical roll 5 having a circumferential groove 5a having a smaller groove width than the circumferential groove 1a of the roll 1 and a cylindrical roll 6 having a flat outer surface as shown in FIG. A
1 and rolling the thick plate portion A2 into the circumferential groove 5a. Next, as shown in FIG. 6D, a thick plate portion A2 curved between the rolls 7 and 8 having a flat outer surface is formed flat.
The above steps are performed a plurality of times as necessary.

In the manufacturing method shown in FIG. 6, when the sheet material A is rolled by the rolls 1 and 2 and the rolls 5 and 6, the sheet material A is not rolled in the circumferential grooves 1a and 5a.
By rolling the vicinity of the plate edge of the plate material A, the deformation of the plate material A is generated in the inward direction of the circumferential grooves 1a and 5a, and in the width direction of the plate edge portion, and the thick plate portion A2 and the thin plate portion A1 in the longitudinal direction. Balance of growth.

The manufacturing method shown in FIG. 7 uses a roll having a convex portion extending in the circumferential direction formed on the outer surface and a cylindrical roll having a flat outer surface to produce a strip having a predetermined dimension by rolling. . That is, as shown in FIG. 7A, two convex portions 1 extending in the circumferential direction are formed on the outer peripheral surface of the cylindrical roll 10.
0a are formed at an interval corresponding to the width of the thick plate portion A2 of the irregular cross-section strip, and a slope 10b is formed on the side surface of each convex portion 10a and is inclined toward the outside of the roll. Is rolled with the plate material A interposed between the roll 11 and the cylindrical roll 11. At this time, the vicinity of the plate edge of the plate material A is the inclined surface 10b.
The sheet is rolled so as to be extruded in the sheet edge direction to form a thin plate portion A1. Further, as shown in FIG.
By rolling using a roll 12 having a convex portion 12a having a width larger than the width of the convex portion 10a of the roll 10 and a columnar roll 13, the thin plate portion A1 is formed by the inclined surface 12b of the convex portion 12a. Widening in the direction. The above steps are performed a plurality of times as necessary.

[0009]

However, the method for manufacturing a profiled strip shown in FIG. 6 or 7 has the following problems to be solved.

That is, in the manufacturing method shown in FIG. 6, since the plate material A is not rolled in the circumferential grooves 1a and 5a of the rolls 1 and 5, surface roughness occurs. In addition, plate material A
Is curved and penetrates into the circumferential grooves 1a, 5a, the thickness of the thick portion A2 near the boundary with the thin portion A1 is larger than the thickness of the other thick portions A2 due to the flow of the material. The thickness distribution of the thick plate portion A2 may become non-uniform. Also in the manufacturing method shown in FIG. 7, there is a similar problem because the rolling is not performed between the convex portions 10a or between the convex portions 12a.

In the manufacturing method shown in FIG. 7, since the rolling of the sheet material A is performed only in the vicinity of the edge of the sheet, it is impossible to increase the widening amount by one rolling. In this case, the rolls have to be arranged over many stages, and workability and productivity have to be deteriorated.

Generally, when rolling a deformed cross-section strip having a different thickness in the width direction from a flat plate material, the rolled portion is deformed in the longitudinal direction, so that a portion having a large processing amount (a thin plate portion) and a small portion (a thick plate). In some cases, there is a difference in elongation in the longitudinal direction between the rolled material and the rolled material, causing wavy deformation or twisting of the rolled material.
In the manufacturing method shown in FIGS. 6 and 7 described above, it is difficult to completely cause material deformation of a portion to be rolled for forming a thin plate portion in the width direction of the thin plate portion. There is a difference in the amount of deformation in the longitudinal direction of the thick plate portion A2 that is not performed. The difference in the amount of deformation varies depending on the roll shape and the amount of rolling. However, when the difference in the amount of deformation is large, defects such as twisting and wave-like deformation of the sheet material during rolling are likely to occur.

In the manufacturing method shown in FIG.
The outer peripheral surfaces of the convex portions 10a, 12a and the convex portions 10a,
A so-called edge drop occurs at a boundary portion between the inclined surfaces 10b and 12b formed on the thin plate portion 12a, and a difference in processing degree occurs between the thin plate portion A1 and the other portions. May occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and aims to make the thickness distribution uniform, improve workability and productivity, prevent torsional deformation and wavy deformation of the plate material, and prevent so-called edge drop. It is an object of the present invention to provide a manufacturing method and a manufacturing apparatus of a deformed cross-section strip that can be formed.

[0015]

According to the method of the present invention, a pair of rolling rolls each having a substantially cylindrical roll body are provided in a plurality of stages, and a sheet material is sequentially rolled by the pair of rolling rolls. In the method for manufacturing a deformed cross-section strip for manufacturing a deformed cross-section strip, at least one of the pair of rolling rolls is formed with at least one protrusion extending substantially all around the roll body and projecting from the roll body. A rotating arc surface about the rotation center axis of the rolling roll is formed substantially at the center, and the radius of curvature of the convex portion formed on each rolling roll is set to gradually increase as the downstream stage in the moving direction of the plate material becomes. Then, while rolling the thin plate portion of the irregular cross section between the convex portion of the rolling roll and the other rolling roll, the thick plate portion of the irregular cross section is rolled by at least a part of the roll body. It is characterized in.

Further, the thin plate portion having the irregularly shaped cross section may be gradually reduced by the plurality of rolling rolls.

It is preferable that the difference in the degree of processing between the thin plate portion and the thick plate portion by the rolling rolls in each step is set within 5%.

[0018] The sheet material may be continuously rolled by the plurality of rolling rolls to produce a profiled strip.

The sheet material may be subjected to an annealing process between the rolling processes by the plurality of rolling rolls.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a method for manufacturing a profiled strip according to an embodiment of the present invention.

As shown in FIG. 1B, the manufacturing method according to the present embodiment employs a substantially cylindrical roll body 21, 31, 41.
A pair of rolling rolls 20, 30, and 40 having three stages are provided, and a sheet material A having a square cross section (see FIG. 1A) is sequentially rolled by the pair of rolling rolls 20, 30, and 40.
This is to produce a modified cross section B having a cross section as shown in FIG. 1 (c). Here, as the plate material A, a metal material such as copper, copper alloy, aluminum, aluminum alloy, iron, and stainless steel, or a composite material using these materials can be used.

In the present manufacturing method, a pair of rolling rolls 20,
The roll body 21,
Two protruding portions 22, 32, and 42 extending over the entire circumference from 31.41 are formed at predetermined intervals, and the distance between the protruding portions 22, 32, 42 is the largest between the protruding portions 22, The space between the protrusions 32 is intermediate, and the space between the protrusions 42 is formed to be the smallest. The convex portions 22, 32, 42 are formed with rotating arc surfaces 22a, 32a, 42a substantially centered on the rotation center axes of the rolling rolls 20, 30, 40, and are formed on the rolling rolls 20, 30, 40 in each stage. Convex part 22,3
The radii of curvature of the plates 2 and 42 are set to be gradually larger as the plate material A moves downstream in the moving direction.

The convex portions 22 of the rolling rolls 20, 30, 40
While the thin plate portion A1 is being rolled between the rolling rolls 32, 42 and the other rolling rolls 20, 30, 40, the thick plate portion A2 is rolled by the roll bodies 21, 31, 41 between the convex portions 22, 32, 42. Specifically, the deformed cross-section strip B is manufactured through the steps shown in FIGS.

That is, as shown in FIG.
0 is rotated and the plate material A is rolled from the left side in the figure to a rolling roll 20.
Supply to Thereby, the plate material A is caught between the pair of rolling rolls 20 as shown in FIG. On this occasion,
The sheet material A is rolled from the shape shown by the dotted line in the drawing, near both plate edges by the double protrusions 22 and widened to form the thin plate portion A1, and also rolled near the center portion by the roll body 21 to form a thick plate. The part A2 is formed.

Sheet material A sent out from rolling roll 20
Is supplied to the rolling rolls 30 and is interposed between the pair of rolling rolls 30 as shown in FIG. At this time, as shown by the dotted line in the figure, the vicinity of both plate edges is rolled and widened by the biconvex portions 32 from the shape formed by the rolling rolls 20 to form a thin plate portion A1, and the roll body 31 is formed.
As a result, the vicinity of the center is also rolled to form a thick plate portion A2.

Sheet material A sent out from rolling roll 20
Is supplied toward the rolling rolls 40 and is interposed between the pair of rolling rolls 40 as shown in FIG. At this time, as shown by the dotted line in the figure, the vicinity of both plate edges is rolled by the double protrusions 42 from the shape formed by the rolling roll 30 to be widened to form the thin plate portion A1, and the roll body 41 is formed.
As a result, the vicinity of the center is also rolled to form a thick plate portion A2.

In the present manufacturing method, the deformed cross-section strip B is manufactured from the sheet material A by passing through the three-stage rolling rolls 20, 30, and 40 as described above.

Next, the operation of the manufacturing method according to the embodiment will be described.

The convex portions 22 of the rolling rolls 20, 30, 40,
The projecting portions 22, 32, 42 of the rolling rolls 20, 30, 40 are arranged such that the thin plate portion A1 is rolled by the rolls 32, 42 and the thick plate portion A2 is rolled by the roll bodies 21, 31, 41 at the same time.
Is set, the thick plate portion A2 can be rolled even when the thin plate portion A1 is rolled and widened, so that the thick plate portion A2 can be elongated and deformed in the longitudinal direction. It is possible to balance with the elongation deformation in the longitudinal direction of the thin plate portion A1 generated by the rolling of A1. As a result, the thin plate portion A
1 and the thick plate portion A2 can be reduced in the difference between the elongation and deformation in the longitudinal direction, and the rolled material can be prevented from waving or twisting due to the difference in elongation and deformation, and the deformed section B can be efficiently used. Can be manufactured well.

The thick plate portion A2 is connected to the roll bodies 21, 3
1, 41, so that the thick plate portion A
The irregularly shaped strip B having excellent surface quality and thickness accuracy can be manufactured without causing the surface roughness and the decrease in plate thickness accuracy of No. 2.

In the rolling by the second-stage rolling roll 30 and the third-stage rolling roll 40, the thickness of the root portion A3 of the thin plate portion A1 is changed to the root portion of the thin plate portion A1 formed by the preceding rolling roll. Rolling is performed so as to be smaller than the plate thickness of A3. These are the rolling rolls 30, 4
0, the thickness of the root A3 of the thin plate part A1 is equal to or smaller than the thickness of the root A3 of the thin plate part A1 rolled by the preceding rolling roll (in other words, almost Is not performed or is not rolled at all), a phenomenon in which the thickness of the root portion A3 of the thin plate portion A1 formed by the preceding roll is slightly reduced due to the elongation deformation in the longitudinal direction caused by rolling by the rolls 30 and 40. This may cause the thickness distribution and the surface condition to deteriorate.

In the rolling by the rolling rolls 30 and 40, the difference between the working ratio of the thin plate portion A1 and the working ratio of the thick plate portion A2 by the rolling roll 20 or the rolling rolls 30 and 40 is within 5%. It is preferable that the working degree of A2 be larger than the working degree of the thin plate portion A1. This makes it possible to more effectively prevent wavy deformation and torsional deformation that occur during rolling.

In the manufacturing method of the above embodiment, the case where the irregularly shaped section B is rolled by the three-stage rolling rolls 20, 30, and 40 has been described. An appropriate number can be adopted in consideration of the degree of processing in the step.

The thin plate portion A1 of the irregularly shaped cross section B manufactured by the manufacturing method of the above embodiment has a slight curvature as shown in FIGS. The thin plate portion A1 may be formed into a cylindrical shape so as to be flat.

In the manufacturing method of the above embodiment, the three-stage rolling rolls 20, 30, and 40 are provided, and the sheet material A is continuously rolled to obtain the deformed cross-section strip B. The plate material A, which is an intermediate material, may be wound and accommodated in each of a plurality of stages, and supplied to a rolling device including a separately provided rolling roll.

In the manufacturing method according to the above embodiment, no heat treatment is applied to the rolled material during the rolling at each stage, but the rolled material is annealed between the rolling at each stage, and the work hardening by rolling is performed. This may be resolved to facilitate the subsequent rolling.

In the manufacturing method of the embodiment, the rotating arc surfaces 22a, 32a, 42a are formed only on one side of the convex portions 22, 32, 42 provided on the rolling rolls 20, 30, 40. Alternatively, a rotating arc surface may be provided on each of the projections 22, 32, and 42.

In the manufacturing method of the above-described embodiment, the deformed cross-section strip B is manufactured by forming the thin plate portion A1 at the plate edge portion of the plate material A and the thick plate portion at the center portion by rolling.
As shown in FIG. 5, a thin plate portion A1 may be formed at the center of the plate material A, and a thick plate portion A2 may be formed at the plate edge.
Also in this case, as shown in FIG.
The convex portion 52 formed on one of the roll main bodies 51 has a rotating arc surface 52 about the rotation axis of the roll main body 51 as a center of rotation.
a is formed, and the thin plate portion A1 and the thick plate portion A2 (the shapes of which are indicated by dotted lines in the figure) rolled by the former roll 50 are further rolled. The same is true.

The manufacturing method according to the embodiment of the present invention can be carried out by various types of manufacturing apparatuses, but one embodiment of the manufacturing apparatus will be described below to facilitate understanding of the present invention.

As shown in FIG. 1 (b), this manufacturing apparatus
A pair of rolling rolls 20, 30, and 40 having substantially cylindrical roll bodies 21, 31, and 41 are provided in three stages in series,
The plate material A having a rectangular cross section (see FIG. 1A) is sequentially rolled by the pair of rolling rolls 20, 30, and 40 to produce an irregular cross section B having a cross sectional shape as shown in FIG. 1C. Things.

At least one of the pair of rolling rolls 20, 30, 40 has two convex portions 22, 32, extending from the roll main bodies 21, 31, 41 and extending over the entire circumference.
42 are formed at predetermined intervals. Each convex part 22,
The distance between the protrusions 32 and 42 is the largest between the protrusions 22, the middle between the protrusions 32, and the smallest between the protrusions 42. The rolling rolls 2 are provided on the convex portions 22, 32, and 42, respectively.
Rotational arc surfaces 22a, 32a, and 42a are formed about the 0, 30, and 40 rotation center axes. Convex parts 22, 3 formed on rolling rolls 20, 30, 40 of each stage
The radii of curvature of the plates 2 and 42 are set to be gradually larger as the plate material A moves downstream in the moving direction.

The convex portions 22 of the rolling rolls 20, 30, 40,
While rolling the thin plate portion B1 having the irregularly shaped cross section B between the rolling portions 32, 42 and the other rolling rolls 20, 30, 40, the convex portions 22,
The thick plate portion B2 of the irregularly shaped strip B is rolled by the roll bodies 21, 31, 41 between 32, 42. As described above, the deformed cross-section strip B is manufactured from the sheet material A through the three-stage rolling rolls 20, 30, and 40.

Next, the operation of the manufacturing apparatus according to the embodiment will be described.

In this manufacturing apparatus, the rolling rolls 20, 30,
The thin plate portion A1 is rolled by the 40 convex portions 22, 32, and 42, and at the same time, the thick plate portion A is rolled by the roll bodies 21, 31, and 41.
Since the heights of the projections 22, 32, 42 of the rolling rolls 20, 30, 40 are set so as to roll the sheet 2, the thick part A2 is rolled when the thin part A1 is rolled and widened. Elongation deformation in the longitudinal direction can be generated in the thick plate portion A2, and the elongation deformation in the longitudinal direction of the thin plate portion A1 caused by rolling of the thin plate portion A1 can be balanced. As a result, the difference between the elongation and deformation in the longitudinal direction between the thin plate portion A1 and the thick plate portion A2 can be reduced, and the occurrence of wavy deformation, twisting, and the like of the rolled material due to the difference in elongation deformation can be eliminated. As a result, the modified cross-section strip B can be manufactured efficiently. Further, the thick plate portion A2 is connected to the roll bodies 21, 31, 41.
Since the shape and arrangement of the rolling rolls 20, 30, and 40 are set so as to perform rolling, the surface quality and thickness accuracy of the thick plate portion A2 are not reduced, and the surface quality and thickness accuracy are excellent. It is possible to manufacture a deformed cross-section strip B.

In the case where the thickness of the root portion A3 of the thin plate portion A1 by the rolling rolls 30, 40 is equal to or smaller than the thickness of the root portion A3 of the thin plate portion A1 rolled by the preceding rolling roll. (In other words, when the roll is hardly rolled or not rolled at all), the root portion A3 of the thin plate portion A1 formed by the preceding roll by the elongation deformation in the longitudinal direction generated by the rolling by the rolls 30 and 40. The phenomenon that the thickness of the plate slightly decreases occurs, and may cause deterioration of the thickness distribution and surface condition.
In the present manufacturing apparatus, in the second-stage rolling roll 30 and the third-stage rolling roll 40, the thickness of the base portion A3 of the thin-plate portion A1 is reduced by the thin-plate portion A formed by the preceding-stage rolling roll.
Since the shape of the rolling rolls 30 and 40 is set so as to be rolled to be smaller than the thickness of the root portion A3 of 1, the deterioration of the thickness distribution and the surface condition does not occur.

In the rolling by the rolling rolls 30 and 40, the difference between the working ratio of the thin plate portion A1 and the working ratio of the thick plate portion A2 by the rolling roll 20 or the rolling rolls 30 and 40 is within 5%, especially the thick plate portion. Since the shape of the rolling rolls 30 and 40 is set so that the working ratio of A2 is greater than the working ratio of the thin plate portion A1, it is possible to more effectively prevent wavy deformation and torsional deformation that occur during rolling. it can.

The production apparatus has three rolling rolls 20, 3
Although the rolling of the deformed cross-section strip B has been described with reference to 0 and 40, the number of steps of the rolling roll can be appropriately selected in consideration of the cross-sectional shape and the working ratio of the deformed cross-section strip B. The thin plate portion A1 of the irregularly shaped cross section B manufactured by the present manufacturing apparatus has a slight curvature as shown in FIG.
The final-stage rolling roll may have a cylindrical shape, and the thin plate portion and the thick plate portion may be formed flat.

In this manufacturing apparatus, the rolling rolls 20 of each stage,
A rolling device including a rolling roll is provided for each stage or for each of a plurality of stages without providing 30 and 40 continuously, and a plate material A which is an intermediate material is wound and accommodated for each rolling device, and a rolling device at a subsequent stage is provided. May be supplied.

During the rolling at each stage, an annealing device comprising a heater or a heating furnace may be provided for annealing the rolled material. Thereby, work hardening due to rolling can be eliminated, and the subsequent rolling can be facilitated.

On one side of the projections 22, 32, 42 provided on the rolling rolls 20, 30, 40, the rotating arc surfaces 22a, 32
a, 42a, but the rotating arc surface is
32 and 42 may be provided on both sides.

In the manufacturing apparatus of the above embodiment, the thin section A1 is formed at the edge of the sheet material A and the thick section is formed at the center to manufacture the irregularly shaped section B. However, FIG. As shown in the drawing, a rotary arc surface 52a about the rotation axis of the roll main body 51 is formed on a convex portion 52 formed on the roll main body 51 of the pair of rolls 50, and the roll roll 50 of the preceding stage is formed.
The shape of the rolling roll is set so that the thin plate portion A1 and the thick plate portion A2 (the shapes are indicated by dotted lines in the figure) are further rolled.
And the thick plate portion A2 may be formed at the plate edge.

[0052]

As described above, according to the method of manufacturing a profiled cross section of the present invention, the thickness distribution can be made uniform.
Workability and productivity can be improved, twisting and wavy deformation of the plate material can be prevented, and so-called edge drop can be prevented.

[Brief description of the drawings]

FIG. 1 is a plan view of a manufacturing apparatus used in a method for manufacturing a profiled strip according to an embodiment of the present invention.

FIG. 2 is a view showing one step of a method of manufacturing a profiled strip according to one embodiment of the present invention.

FIG. 3 is a view showing one step of a method of manufacturing a profiled strip according to an embodiment of the present invention.

FIG. 4 is a view showing one step of a method of manufacturing a profiled strip according to an embodiment of the present invention.

FIG. 5 is a view showing a method for manufacturing a modified cross-section strip according to another embodiment of the present invention.

FIG. 6 is a diagram showing a method of manufacturing a modified cross-section strip to be compared in order to clarify the technical significance of the present invention.

FIG. 7 is a view showing a method of manufacturing a profiled strip to be compared in order to clarify the technical significance of the present invention.

[Explanation of symbols]

 20, 30, 40, 50 Rolling roll 21, 31, 41, 51 Roll body 22, 32, 42, 52 Convex portion 22a, 32a, 42a, 52a Rotating arc surface A Plate material A1 Thin plate portion A2 Thick plate portion B Irregular cross section strip

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Noboru Hagiwara 3550 Kida Yomachi, Tsuchiura-shi, Ibaraki Hitachi Cable, Ltd.

Claims (5)

[Claims] 1. A method for manufacturing a profiled cross section in which a pair of rolling rolls having a substantially cylindrical roll body is provided in a plurality of stages, and a sheet material is sequentially rolled by the pair of rolls to produce a profiled cross section. At least one of the pair of rolling rolls is formed with at least one projection extending from the roll main body and extending substantially all around the circumference,
The convex portion is formed with a rotating arc surface substantially centered on the rotation center axis of the rolling roll, and as the radius of curvature of the convex portion formed on each of the rolling rolls becomes a downstream stage in the moving direction of the plate material. Rolling the thick plate portion of the irregular cross section by at least a part of the roll body while rolling the thin plate portion of the irregular cross section between the convex portion of the rolling roll and the other rolling roll, which is set to be gradually larger. A method for producing a deformed cross-section strip, characterized in that: 2. The method according to claim 1, wherein the thin plate portion having the irregular cross section is gradually reduced by the plurality of rolling rolls. 3. The method for producing a deformed cross-section strip according to claim 1, wherein the difference in the degree of processing of the thin plate portion and the thick plate portion by the rolling rolls at each stage is within 5%. 4. The method for producing a deformed cross-section strip according to claim 1, wherein the sheet material is continuously rolled by the plurality of rolling rolls to produce a deformed cross-section strip. 5. The method according to claim 1, wherein the sheet material is subjected to an annealing process during the rolling process by the plurality of rolling rolls.