JPH08267309A - Trimming gear of metal band plate - Google Patents

Abstract

PURPOSE: To provide a trimming ger of a metal band plate, capable of shearing the edge part of a metal band plate in a highly accurate manner by preventing any warp in the cross direction of this metal band plate from occurring. CONSTITUTION: This is a trimming gear of a metal band plate where two shearing machines 2 and 3 are installed along a conveyor route of a metal band plate 1, positioning four cutters 2e, 2d, 3e and 3d of these shearing machines 2 and 3 at two cross directional edge parts 1a and 1b of this metal band plate 1 being conveyed in succession, and then the cross directional edge parts is continuously shearing at the specified trimming width C1, C2. In addition, two expander rolls 4 and 5 imparting tensile force T1 and T2 to the metal band plate 1 toward both the edge parts 1a and 1b from a central part of this band plate in the cross direction are installed in the conveyor route at an adjacent position from the shearing machines 2 and 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trimming device for shearing a widthwise edge of a metal strip with a predetermined trimming width in a metal strip production line.

[0002]

2. Description of the Related Art A metal strip (hereinafter referred to as a steel strip) manufacturing line has a trimming process in which a shearing device is used to shear a widthwise edge portion of a steel strip with a predetermined trimming width. As a device used in this trimming process, for example, a trimming device disclosed in Japanese Patent Laid-Open No. 163819/1986 is known.

In this trimming device, first, a bridle roll is arranged at a position in the front-rear direction (longitudinal direction of the steel strip) sandwiching the shearing position of the steel strip to apply tension in the longitudinal direction of the steel strip. Then, one widthwise edge of the steel strip is used as a reference edge, the other widthwise edge is used as an edge to be sheared (shearing edge), and a shearing device that allows the cutter to move in the plate width direction is provided. The cutter is engaged with the shearing edge side, and the plate width of the steel strip immediately before passing through the shearing device is detected by a width meter. Then, the reference edge is aligned with the reference position, the cutter is positioned at the position of the set width, and the shearing edge side is sheared. The trimming device detects the position sheared by the shearing device, calculates the error between the detected width and the set width, and adjusts the position of the cutter if there is an error.

[0004]

However, in the above-mentioned conventional trimming device, the bridle roll is arranged to apply tension in the longitudinal direction of the steel strip to prevent warpage of the steel strip in the longitudinal direction. , Not enough tension is applied in the width direction of the steel strip. Therefore, if the trimming process is performed in a state where the steel strip is warped in the width direction, it cannot be sheared with an accurate trimming width, and thus a highly accurate strip width cannot be obtained.

Further, since the warp of the steel strip in the width direction is not prevented, the shearing work cannot be normally performed even if the trimming width is made minute (for example, about 3 mm) and shearing is performed. As a result, it is impossible to avoid a reduction in yield in the trimming process. Further, flapping vibration occurs in the steel strip conveyed due to the occurrence of the warp in the width direction, and the flapping vibration easily causes the cutter to be worn or damaged. Therefore, since the cutter must be replaced frequently, there is a problem in terms of production capacity in the trimming process.

The present invention has been made in view of the above circumstances, and it is possible to highly accurately shear the edge portion of a metal strip by preventing the metal strip from warping in the width direction. An object of the present invention is to provide a plate trimming device.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 is arranged such that a shearing device is arranged along a metal path of the metal strip, and the metal strip is conveyed. In a trimming device for a metal strip, in which a cutter of the shearing device is located at an edge in the width direction and the edge in the width direction is continuously sheared with a predetermined trimming width, the transport path immediately preceding the shearing device. In the apparatus, an expander roll that applies tension to the metal strip from the center portion in the width direction of the metal strip toward both edges is provided.

According to a second aspect of the present invention, a shearing device is arranged along the conveying path of the metal strip, and the cutter of the shearing device is positioned at the widthwise edge of the metal strip being conveyed. In the trimming device for a metal strip that continuously shears the widthwise edge portion with a predetermined trimming width, the transport path immediately before the shearing device and the transporting position immediately after the shearing device. The device is characterized in that an expander roll that applies tension to the metal strip from the center portion in the width direction of the metal strip to both edges is provided in the path.

According to a third aspect of the invention, in the invention of the first or second aspect, the expander roll is
While being constituted by a pair of upper and lower rolls that rotate in mutually opposite directions while closely contacting the outer peripheral surfaces made of an elastic body to the front and back surfaces of the metal strip that has been conveyed, the outer peripheral surfaces of these upper and lower rolls have an axial direction of the rolls. The top is located in the center,
In addition, V is applied from the top in the direction opposite to the direction of roll rotation.
A V-shaped convex strip that opens in a V-shape and projects from the outer peripheral surface, and two V-shaped convex strips that continuously extend from two branch portions of the V-shaped convex strip to both end sides in the axial direction of the roll. The device is characterized in that a spiral ridge is formed.

According to a fourth aspect of the invention, in the invention of the first or second aspect, the expander roll is
While being constituted by a pair of upper and lower rolls that rotate in mutually opposite directions while closely contacting the outer peripheral surfaces made of an elastic body to the front and back surfaces of the metal strip that has been conveyed, these upper and lower rolls are provided at the central portion in the longitudinal direction of the rotating shaft. Is curved so as to be eccentric to the downstream side of the transport path.

[0011]

According to the first aspect of the present invention, the metal strip, which has been warped in the width direction and is fed, is expanded in the width direction by the expander roll provided in the conveying path immediately before the shearing device. Tension is applied from the center of the to both edges. As a result, the metal strip that has been warped in the width direction is corrected immediately before going to the shearing device, and has a uniform flat shape in the width direction. Then, the cutter of the shearing device can shear the edge portion in the width direction with the same size as the set trimming width, so that a metal strip plate having a highly precise plate width dimension can be obtained.

Further, since the metal strip to be sheared has a flat shape uniformly in the width direction, the cutter of the shearing device can surely engage and perform shearing even if the trimming width is small. it can. This makes it possible to improve the yield of the metal strip in the trimming process. Further, since the warp of the metal strip in the width direction is corrected, there is no flap vibration of the metal strip toward the shearing device, so that the cutter of the shearing device is hardly worn or damaged. This makes it possible to improve the production capacity of the trimming process.

According to the second aspect of the present invention, the action of the first aspect can be obtained, and since the expander roll is also arranged in the conveying path immediately after the shearing device, the metal strip is provided. The flatness in the width direction of the plate can be further increased, and the shearing accuracy of the trimming width is improved. Further, by disposing the two expander rolls immediately before and after the shearing device, it becomes possible to prevent warpage of the metal strip in the longitudinal direction without disposing the bridle roll as in the prior art. .

On the other hand, according to the third aspect of the invention, the outer peripheral surfaces of the upper and lower rolls that rotate in opposite directions while being in close contact with the front and back surfaces of the metal strip are formed at the central portion in the axial direction thereof. Due to the elastic deformation of the V-shaped ridge, tension is applied to the metal strip from the center in the width direction toward both edges. Also,
Due to the elastic deformation of the spiral ridges which are continuously formed from the branches of the V-shaped ridges and spirally spread to the outer peripheries of both ends of the upper and lower rolls, the metal strip plate is further directed toward both edges in the width direction. Apply tension. As a result, when the metal strip having a warp in the width direction passes between the upper and lower rolls, the metal strip is straightened into a flat shape in the width direction.

Further, according to the invention of claim 4, since the upper and lower rolls are formed so as to be curved so that the central portion in the longitudinal direction of the rotating shaft is eccentric to the downstream side of the conveying path, the metal strip plate is formed. The outer peripheral surfaces of the upper and lower rolls that rotate in opposite directions while closely contacting with the front and back surfaces rotate while facing both edges of the metal strip with the central portion as a boundary. Thereby, tension is applied to the metal strip from the center in the width direction toward both edges.
As a result, when the metal strip having a warp in the width direction passes between the upper and lower rolls, the metal strip is straightened into a flat shape in the width direction.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic view of the present invention, and FIGS. 2 to 4 show a first embodiment of the present invention. As shown in FIGS. 1 and 2, the trimming device according to the first embodiment is arranged on both side edges 1a, 1b in the width direction of a metal strip (hereinafter referred to as a steel strip) that has been conveyed from the previous step. A pair of shearing devices 2 and 3 provided, a first expander roll 4 through which the steel strip 1 immediately before going to these shearing devices 2 and 3 passes, and shearing devices 2 and 3 shear both edges 1a and 1b. The second expander roll 5 through which the steel strip 1 immediately after being passed is provided.

As shown in FIGS. 2 and 3, the shearing device 2 includes a drive portion 2a arranged on one widthwise edge 1a side of the steel strip 1 and a width of the steel strip 1 from the drive portion 2a. The drive shafts 2b and 2c extend inward in the direction and are parallel to and separated from each other in the vertical direction, and the rotary cutters 2d and 2e fixed to the tip ends of the drive shafts 2b and 2c, respectively. . The rotary cutters 2d and 2e are connected to the drive shafts 2b and 2e.
By performing the reverse rotation operations of c, the widthwise edges 1a and 1b of the conveyed steel strip 1 are sheared by a predetermined trimming width C ₁ . Then, the shearing device 3 arranged on the other widthwise edge portion 1b side of the steel strip 1 has the same structure as the shearing device 2, and the rotating cutter 3d and the rotating cutter 3e that have been rotated have been conveyed. 1 is sheared with a predetermined trimming width C ₂ .

Although not shown, the shearing devices 2 and 3 are
The steel strip 1 is movable in the width direction, and when the set plate width S of the steel strip 1 is changed, the rotary cutters 2d, 2e, Three
The positions of d and 3e are adjusted. Further, the symbol K shown in FIG. 2 is shearing debris. On the other hand, the first expander roll 4 through which the steel strip 1 is passed immediately before going to the shearing devices 2 and 3 has a surface 1c of the steel strip 1 as shown in FIG.
An upper roll 6 that contacts with the lower roll 7 that contacts the back surface 1d of the steel strip 1, and upper and lower rolls 6 and 7 so that the outer peripheral surfaces of the upper and lower rolls 6 and 7 come into close contact with the front and back surfaces 1c and 1d of the steel strip 1. And a bearing member 8 for rotatably supporting the bearing.

As shown in FIG. 2, the upper roll 6 has a rotary shaft 6a rotatably supported by a bearing member 8,
An elastic roll 6b made of rubber or the like, which is longer than the plate width L of the steel strip 1 conveyed from the previous step, is externally fitted. Then, on the outer peripheral surface of the elastic roll 6b, the apex portion 10a is located at the central portion in the axial direction, and the apex portion 10a opens in a V-shape in a direction opposite to the rotation direction R ₁ of the elastic roll 6 to open from the outer peripheral surface. A protruding V-shaped ridge 10 is formed. And
Continuing from the branch portions 10b, 10c of this V-shaped convex strip 10,
Moreover, two spiral ridges 11a and 11b, which respectively extend spirally to both ends of the elastic roll 6b, are formed so as to project from the outer peripheral surface. Since the lower roll 7 has the same structure as the upper roll 6, the description thereof will be omitted.

Further, the shearing devices 2 and 3 are provided with both edge portions 1a and 1b.
The second expander roll 5 through which the steel strip 1 immediately after being sheared is also constituted by the first upper roll 6 and the second lower roll 7 having the above-mentioned configuration. When the trimming process is performed using the trimming device having the above configuration, the shearing device 2,
The steel strip 1 conveyed toward the steel strip 3 passes through the first expander roll 4 at a position immediately before the shears 2 and 3, and the steel strip 1
The front surface 1c of the lower roll 7 is in close contact with the outer peripheral surface of the upper roll 6 rotating in the R ₁ direction, and the back surface 1d is the lower roll 7 rotating in the R ₂ direction.
Close to the outer peripheral surface of. At that time, the steel strip 1 is deformed by elastic deformation of the V-shaped ridge formed on the outer peripheral surfaces of the upper and lower rolls 6 and 7 in the central portion in the axial direction by opening in a V-shape in the direction opposite to the rotation direction. Both widthwise edges 1b, 1c from the widthwise central portion
Tensions T ₁ and T ₂ are applied which are directed to the sides. Furthermore, the V
Due to the elastic deformation of the spiral ridges that are continuously formed from the character-shaped ridges and spirally spread to the outer peripheries of both ends of the upper and lower rolls 6 and 7, toward both edges 1b and 1c in the width direction of the steel strip 1. The applied tensions T ₁ and T ₂ increase.

As a result, even if the steel strip 1 which has been warped in the width direction is conveyed from the previous step, the first expander rolls 4 give the steel strip 1 both widthwise edges 1a, 1b.
By the tensions T ₁ and T ₂ directed to the steel strip 1, the widthwise warp of the steel strip 1 is corrected as shown in FIG.
The shape is flat up to a and 1b. Then, the steel strip 1 whose warp in the width direction has been corrected is conveyed to the shearing devices 2 and 3, whereby the rotary cutters 2d, 2e and 3 of the shearing devices 2 and 3 are conveyed.
With d and 3e, both edges 1a and 1b of the steel strip 1 can be reliably and continuously sheared in a width that matches the set trimming widths C ₁ and C ₂ . Then, both edge portions 1a and 1b of the steel strip 1 are surely sheared by the set trimming widths C ₁ and C ₂ , so that the steel strip 1 having a highly accurate strip width dimension S is obtained.
Can be formed.

In FIG. 3, what is indicated by a chain double-dashed line is a state in which the steel strip 1 which is warped in the width direction is conveyed to the shearing device 2 without passing through the first expander roll 4. Is. As is clear from this figure, the steel strip 1 having a warp in the width direction cannot be sheared with an accurate trimming width. Further, in the present embodiment, the steel strip 1 immediately after the both edge portions 1a and 1b are sheared by the shearing devices 2 and 3.
Also, by passing through the second expander roll 5,
Tensions T ₁ and T ₂ are applied toward both edges 1a and 1b in the width direction. As a result, the flatness in the width direction of the steel strip 1 located between the first and second expander rolls 4 and 5 is improved, so that the edges 1a and 1b can be more accurately sheared. . Further, by disposing the first and second expander rolls 4 and 5 immediately before and after the shearing devices 2 and 3, it is possible to remove the steel strip 1 from the steel strip 1 without disposing the bridle roll unlike the prior art. Warpage in the longitudinal direction can also be prevented. Of course, the bride roll may be arranged in a conventional manner.

Further, both widthwise edges 1a, 1b of the steel strip 1 are formed.
Has a flat shape, the rotating cutters 2d of the shearing devices 2 and 3 can be used even when shearing is performed with a small trimming width.
The 2e, 3d, and 3e can be securely engaged to perform shearing. As a result, the yield in the trimming process can be improved. Further, since the warp in the width direction of the steel strip 1 is corrected, there is no flap vibration of the steel strip 1, and the rotary cutters 2d, 2e and 3 of the shearing devices 2 and 3 are eliminated.
The d and 3e are hardly worn or damaged, so that the production capacity of the trimming process can be improved.

Next, FIG. 4 shows a trimming device according to a second embodiment of the present invention. The same components as those shown in FIGS. Is omitted. In the present embodiment, the first expander roll 20 through which the steel strip 1 immediately before going to the shearing devices 2, 3 passes through the steel strip 1
Upper roll 21 that comes into contact with the front surface 1c of the
and a lower roll (not shown) in contact with d.

The upper roll 21 is an elastic roll made of rubber or the like, which is longer than the plate width L of the steel strip 1 conveyed from the previous step on the rotary shaft 22 which is rotatably supported by the bearing member 8. 23 is externally fitted. The outer peripheral surface of the elastic roll 23 is not formed with the ridges or the like provided in the above embodiment. Further, in the rotary shaft 22 of the present embodiment, a line Q connecting both ends 22b and 22c of the axis P is made to be orthogonal to the conveying direction of the steel strip 1, and a central portion 22a of the axis P with respect to the line Q is formed. Is curved so that it is located on the downstream side of the belt 1 in the transport direction. As a result, the elastic roll 23 is fitted onto the rotary shaft 22 so that the outer peripheral surfaces with the central portion in the longitudinal direction as a boundary face the edges 1 a and 1 b of the steel strip 1, respectively.

The lower roll, which constitutes the first expander roll 20 (not shown), like the rotary shaft 22 of the upper roll 21, has a central portion in the axial direction with respect to both ends of the axis of the rotary shaft. Is curved so that it is located on the downstream side of the belt 1 in the transport direction. Further, the second expander roll 24 through which the steel strip 1 immediately after the both edge portions 1a, 1b are sheared by the shearing devices 2, 3 is also configured the same as the first expander roll 20.

When a trimming process is performed by using the trimming device having the above-described structure, the steel strip 1 conveyed to the shearing devices 2 and 3 has a first expander roll at a position immediately before the shearing devices 2 and 3. After passing through 20, the surface 1c of the steel strip 1 becomes R
_The back surface 1d comes into close contact with the outer peripheral surface of the upper roll 21 rotating in _one direction, and the back surface 1d comes into close contact with the outer peripheral surface of the lower roll rotating in the R ₂ direction. At that time, the elastic roll 23 of the upper roll 21 of this embodiment
Are provided so that their outer peripheral surfaces face the edges 1a and 1b of the steel strip 1 with the central portion in the longitudinal direction as a boundary portion, respectively. Tensions T ₃ and T ₄ directed toward both edges 1b and 1c in the direction are given. Similarly, the lower roll constituting the first expander roll 20 also applies to the steel strip 1 tensions T ₃ and T ₄ directed from the widthwise central portion toward both widthwise edge portions 1b and 1c.

As a result, even if the steel strip 1 having a warp in the width direction is conveyed from the previous step, the first expander roll 20 gives both edges 1a, 1 in the width direction to the steel strip 1.
The warp in the width direction is corrected by the tensions T ₃ and T ₄ toward b, and the steel strip 1 has a flat shape up to both edge portions 1a and 1b in the width direction. Further, in the present embodiment, the steel strip 1 immediately after the both edge portions 1a and 1b are sheared by the shearing devices 2 and 3 also passes through the second expander roll 24 so that the both edge portions 1a and 1b in the width direction. Tensions T ₃ and T ₄ are applied toward the sides. Thereby, the first and second expander rolls 2
The flatness in the width direction of the steel strip 1 located between 0 and 24 is improved. Further, by disposing the first and second expander rolls 20 and 24 immediately before and after the shearing devices 2 and 3, warpage of the steel strip 1 in the longitudinal direction is also corrected. Therefore, the present embodiment can obtain the same effect as the first embodiment.

FIG. 5 shows variations in the trimming device using the expander rolls 4 and 5 according to the present invention and the trimming device not using the expander roll when shearing is performed by setting a trimming width of 3 mm. It is the experimental result which showed the range. When using the expander rolls 4 and 5, the distance between the shearing devices 2 and 3 and the expander rolls 4 and 5 is set within 1 m.

As is clear from the results of this experiment, the trimming device which does not use the expander roll is 1.5-1.5.
A variation of 4.5 mm is generated, and the minimum setting value of the trimming width in operation is 3 mm. However, the trimming device using the expander rolls 4 and 5 of this device is 1.5 to 5.
The variation is 2.5 mm, and the minimum setting value of the trimming width during operation can be 1.5 mm. As a result, since the trimming width can be made minute and the shearing work can be reliably performed, the yield of the metal strip in the trimming process can be significantly improved.

[0031]

As described above, according to the first aspect of the present invention, the metal strip that has been warped in the width direction and has been fed has an expander provided in the conveying path immediately before the shearing device. Tension is applied from the widthwise center to both edges by the roll, and the metal strip that had warped in the widthwise direction is straightened just before going to the shearing device and evenly flattened in the widthwise direction. Since it has such a shape, it is possible to shear the edge portion in the width direction with the same size as the trimming width set by the cutter of the shearing device, and it is possible to obtain a metal strip plate with a highly accurate plate width dimension.

Further, since the metal strip to be sheared is corrected into a flat shape uniformly in the width direction, the cutter of the shearing device can surely engage and shear even if the trimming width is small. Therefore, the yield of the metal strip in the trimming process can be improved. Furthermore, by correcting the warp in the width direction of the metal strip, there is no flap vibration of the metal strip toward the shearing device, and the cutter of the shearing device hardly wears or damages. Can be improved.

The invention according to claim 2 can obtain the effect according to claim 1, and since the expander roll is also arranged in the conveying path immediately after the shearing device, the metal strip is provided. The flatness of the plate in the width direction can be further increased, and the shearing precision of the trimming width can be improved. By disposing the two expander rolls immediately before and after the shearing device, it is possible to prevent warpage of the metal strip in the longitudinal direction without disposing the bridle roll as in the prior art. .

On the other hand, according to the third aspect of the present invention, the outer peripheral surfaces of the upper and lower rolls that rotate in opposite directions while being in close contact with the front and back surfaces of the metal strip are formed at the central portion in the axial direction thereof.
Due to the elastic deformation of the V-shaped ridges, tension is applied to the metal strip from the center in the width direction toward both edges, and the V-shaped ridges are continuously formed to form the outer circumference of both ends of the upper and lower rolls. Due to the elastic deformation of the spiral ridge extending spirally, the metal strip further applies tension toward both edges in the width direction. As a result, by simply passing the metal strip having a warp in the width direction between the upper and lower rolls, the metal strip can be corrected to a uniform flat shape in the width direction and a normal trimming operation can be performed.

In the invention according to claim 4, the upper and lower rolls are formed so as to be curved so that the central portions in the longitudinal direction of their rotating shafts are eccentric to the downstream side of the conveying path. The outer peripheral surfaces of the upper and lower rolls, which rotate in opposite directions while closely contacting the front and back surfaces of, rotate while facing both edge sides of the metal strip with the central part as a boundary, and the center in the width direction with respect to the metal strip. The tension is applied from the part to both edges. As a result, by simply passing the metal strip having a warp in the width direction between the upper and lower rolls, the metal strip can be straightened into a uniform flat shape in the width direction and a normal trimming operation can be performed.

[Brief description of drawings]

FIG. 1 is a schematic view showing an arrangement of a trimming device of the present invention.

FIG. 2 is a plan view showing a first embodiment of the present invention.

FIG. 3 is a view showing a state where the widthwise edge of the metal strip is sheared by the cutter of the shearing device of the present invention.

FIG. 4 is a plan view showing a second embodiment of the present invention.

FIG. 5 is a comparison diagram of a trimming device of the present invention using an expander roll and a conventional trimming device.

[Explanation of symbols]

1 Steel strip (metal strip plate) 1a, 1b Width direction edge part of steel strip 2, 3 Shearing devices 2e, 2d, 3e, 3d Rotating cutter (cutter) 4, 5, 20, 24 Expander roll 6, 21 Upper roll 6a, 7a, 22 rotating shaft 6b, 7b, 23 elastic roll 7 lower roll 10 V-shaped convex strip 10a top 10b, 10c branch 11a, 11b spiral convex strip C ₁ , C ₂ trimming width T ₁ , T ₂ , T ₃ , T ₄ Tension applied from the widthwise center of steel strip to both edges

Claims (4)

[Claims] 1. A shearing device is arranged along a conveying path of a metal strip, and a cutter of the shearing device is positioned at a widthwise edge of the metal strip being conveyed. In a trimming device for a metal strip that is continuously sheared with a predetermined trimming width, in the transport path immediately before the shearing device, from the central portion in the width direction of the metal strip with respect to the metal strip. A trimming device for a metal strip, which is provided with expander rolls that apply tension toward both edges. 2. A shearing device is arranged along a conveying path of the metal strip, and a cutter of the shearing device is positioned at a widthwise edge of the metal strip being conveyed. In a trimming device for a metal strip that is continuously sheared with a predetermined trimming width, the metal strip is provided in the transport path immediately before the shearing device and the transport path immediately after the shearing device. On the other hand, a trimming device for a metal strip, which is provided with an expander roll that applies tension from a central portion in the width direction of the metal strip to both edges. 3. The expander roll is composed of a pair of upper and lower rolls that rotate in opposite directions while closely contacting the outer peripheral surfaces made of an elastic material with the front and back surfaces of the conveyed metal strip, and On the outer peripheral surface of the roll, a top portion is located at the central portion in the axial direction of the roll, and from this top portion, a V-shaped convex strip that opens in a V-shape in a direction opposite to the rotation direction of the roll and projects from the outer peripheral surface is formed. 2. Two spiral ridges, each of which extends in a spiral shape from the two branch portions of the V-shaped ridge continuously to both ends in the axial direction of the roll, are formed. The metal strip trimming device according to 2. 4. The expander roll is composed of a pair of upper and lower rolls that rotate in opposite directions while closely contacting the outer peripheral surfaces made of an elastic body with the front and back surfaces of the conveyed metal strip, and The trimming device for a metal strip according to claim 1 or 2, wherein the roll is formed so as to be curved so that a central portion in the longitudinal direction of the rotating shaft is eccentric to the downstream side of the transport path.