Method for manufacturing thin strips

Abstract

To provide a manufacturing method of a thin strip which can suppress damage of a rotary die cutter.SOLUTION: A manufacturing method of a thin strip manufactures a thin strip from a thin strip-like material by use of a rotary die cutter which includes an anvil roll and a die roll. The anvil roll includes an anvil roll body. The die roll includes: a die roll body in which a cutting blade protrudes on an outer peripheral surface; and a die roll elastic layer which is arranged at both side of the cutting blade on the outer peripheral surface of the die roll body. When passing the thin strip-like material laid on the surface of an anvil side elastic layer through between the anvil roll and the die roll, the cutting blade of the die roll is pushed into a cutting position of the thin strip-like material so that the elastic force of the anvil side elastic layer applies tensile stress caused by bending to the cutting position of the thin strip-like material, and then, when the cutting blade of the die roll is separated from the cutting position of the thin strip-like material, the elastic force of the anvil side elastic layer and the die roll elastic layer applies tensile stress caused by bend restoration to the cutting position of the thin strip-like material.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a method for producing thin strips by stamping the strips from a thin strip using a rotary die cutter. [Background technology]

[0002] Conventionally, there has been a need to manufacture thin strips of a predetermined shape from thin strip materials such as metal sheets, metal strips, and metal foils made of metal materials, etc. This is because components mounted in various machines and electronic devices are often formed from thin strips having such predetermined shapes. Specifically, as described in Patent Document 1, for example, a laminated core used in a motor core or the like is formed by stacking thin strips made of an amorphous alloy, etc. Furthermore, many of the electrodes provided in secondary batteries and fuel cells are formed from metal strips.

[0003] Conventionally, press punching has been used as a processing method for producing thin strip pieces of a predetermined shape from thin strip material, but in recent years, processing methods using rotary die cutters have come to be used in order to improve productivity, etc.

[0004] As a processing method using a rotary die cutter, for example, Patent Document 2 describes a processing method using a rotary cutter that punches out very thin metal members (thin strips) such as thin metal sheets and metal foils into a predetermined shape by shearing. This rotary cutter includes a first rotating member, a second rotating member, and an elastic body. In this rotary cutter, the first rotating member has at least one of a convex portion and a concave portion on its surface. The second rotating member is rotatable in the opposite direction to the first rotating member and has at least one of a convex portion and a concave portion on its surface. The elastic body is attached to at least a portion of a stepped portion of the edge formed by the convex portion or the concave portion of the first rotating member. Furthermore, the elastic body is attached to at least a portion of a stepped portion of the edge formed by the convex portion or the concave portion of the second rotating member. The metal member is then sheared between the edges of the first rotating member and the second rotating member.

[0005] Furthermore, as a processing method using a rotary die cutter, for example, Patent Document 3 describes a processing method using a die-cutting device equipped with a rotary die and an anvil roll. In this device, the rotary die has a die-cutting roll and a cutting blade shaped to protrude radially outward from the die-cutting roll, and the cutting blade includes a pair of first blade portions shaped to protrude from the outer peripheral surface along the circumferential direction of the die-cutting roll and spaced apart in the axial direction of the die-cutting roll. Furthermore, the rotary die has a sponge that sandwiches the first blade portions in the axial direction of the die-cutting roll, and the sponge has a compression ratio set to 40% or more at the point where the distance between the die-cutting roll and the anvil roll is shortest. In this die-cutting device, when an electrode intermediate passes between the rotary die and the anvil roll, the cutting blade of the rotary die enters a thin strip material such as an electrode intermediate, cutting the thin strip material along a planned cutting line, thereby producing a thin strip piece of a predetermined shape from the thin strip material. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2017 / 006868 [Patent Document 2] Patent No. 6037690 [Patent Document 3] Japanese Patent Application Publication No. 2017-132019 Summary of the Invention [Problem to be solved by the invention]

[0007] In contrast, thin strip materials made of metal materials and the like are not easy to cut because they have high hardness and low ductility. Therefore, when a rotary die cutter such as the rotary cutter described in Patent Document 2 is used to punch out thin strip materials with high hardness and low ductility by shearing, the rotary die cutter is easily damaged due to rapid wear.

[0008] Furthermore, even when a rotary die cutter such as the die-cutting device described in Patent Document 3 is used to punch out thin strip pieces from a thin strip material by cutting the thin strip material with a cutting blade, if the thin strip material is hard and has low ductility, the rotary die cutter is prone to damage due to the heavy load placed on the cutting blade.

[0009] The present invention has been made in consideration of these points, and its object is to provide a method for manufacturing thin strips by punching thin strips from thin strip material using a rotary die cutter, which method can suppress damage to the rotary die cutter. [Means for solving the problem]

[0010] In order to solve the above problems, the manufacturing method of the thin strip of the present invention is a method for manufacturing a thin strip by punching out the thin strip from a thin strip material using a rotary die cutter equipped with an anvil roll and a die roll, wherein the anvil roll includes an anvil roll body, and the die roll includes a die roll body having a cutting blade having a shape corresponding to the periphery of the thin strip protruding from its outer circumferential surface, and a die roll elastic layer provided on both sides of the cutting blade on the outer circumferential surface of the die roll body, and the manufacturing method of the thin strip includes cutting the thin strip at a desired cutting position when the thin strip placed on the die roll side surface of the anvil side elastic layer arranged on the outer circumferential surface of the anvil roll body is passed between the anvil roll and the die roll. The punching process includes a punching step in which the thin strip pieces are punched out from the thin strip material, and in the punching step, when the cutting blade of the die roll is pushed into the cutting position of the thin strip material, the elastic force of the anvil-side elastic layer is applied to both sides of the cutting position of the thin strip material, thereby applying a tensile stress due to bending to the cutting position of the thin strip material, and then, when the cutting blade of the die roll is pulled away from the cutting position of the thin strip material, the elastic force of the anvil-side elastic layer is applied to the cutting position of the thin strip material, while the elastic force of the die roll elastic layer is applied to both sides of the cutting position of the thin strip material, thereby applying a tensile stress due to bending back to the cutting position of the thin strip material, thereby cutting the thin strip material at the cutting position. [Effects of the Invention]

[0011] According to the present invention, damage to the rotary die cutter can be suppressed. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a side view schematically showing a punching device according to a first embodiment. [Figure 2] 1 is a schematic plan view showing a thin strip punched out from a thin strip material using a thin strip manufacturing method according to a first embodiment. FIG. [Figure 3A] 2A to 2C are cross-sectional views schematically illustrating steps in a method for manufacturing a thin strip according to the first embodiment. [Figure 3B] 2A to 2C are cross-sectional views schematically illustrating steps in a method for manufacturing a thin strip according to the first embodiment. [Figure 3C] 2A to 2C are cross-sectional views schematically illustrating steps in a method for manufacturing a thin strip according to the first embodiment. [Figure 3D] 2A to 2C are cross-sectional views schematically illustrating steps in a method for manufacturing a thin strip according to the first embodiment. [Figure 4] 5(a) to 5(c) are cross-sectional views schematically showing each stage of a cutting process of a ribbon material at a cutting position in a punching step of the ribbon manufacturing method according to the first embodiment. [Figure 5] FIG. 10 is a side view schematically showing a punching device according to a second embodiment. [Figure 6] 10A to 10C are cross-sectional views schematically illustrating the steps of a method for manufacturing a thin strip according to a second embodiment. [Figure 7] 10(a) to 10(d) are cross-sectional images showing various stages of the cutting process near the cutting position of a ribbon material observed when the ribbon manufacturing method according to the first embodiment is carried out using an actual machine. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a method for manufacturing a thin strip according to an embodiment will be described. First, an outline of the method for manufacturing a thin strip according to the embodiment will be described by taking the methods for manufacturing a thin strip according to the first embodiment and the second embodiment as examples.

[0014] (First embodiment) Fig. 1 is a side view schematically showing a punching device according to the first embodiment. Fig. 2 is a schematic plan view showing a thin strip punched out of a thin strip using the thin strip manufacturing method according to the first embodiment. Figs. 3A to 3D are cross-sectional views schematically showing steps in the thin strip manufacturing method according to the first embodiment. Figs. 4(a) to 4(c) are cross-sectional views schematically showing each stage of the cutting process at the cutting position of the thin strip in the punching step of the thin strip manufacturing method according to the first embodiment.

[0015] As shown in FIG. 1, the punching device 1 according to the first embodiment includes a material supply unit 10, a conveying unit 20, a rotary die cutter 30, and a material recovery unit 40. In the punching device 1, an amorphous alloy ribbon is supplied as a ribbon material W from the material supply unit 10. The ribbon material W supplied from the material supply unit 10 is conveyed by the conveying unit 20 to the rotary die cutter 30, which then punches out the ribbon material W into ribbon pieces M shown in FIG. 2. The punched ribbon material W' is conveyed by the conveying unit 20 to the material recovery unit 40 and recovered by the material recovery unit 40. The ribbon pieces M are obtained by further dividing the ribbon pieces constituting each layer of the laminated stator core in the circumferential direction.

[0016] The material supply unit 10 has a rotating shaft 11 rotatable in the direction of the arrow so that the thin strip material W can be unwound and supplied to the rotary die cutter 30, and the thin strip material W is wound around the rotating shaft 11. The conveying unit 20 has a pair of conveying rolls 21 that rotate with the thin strip material W sandwiched between them. The pair of conveying rolls 21 are arranged so that their rotation axes are parallel to each other, and rotate in opposite directions as shown by the arrows to convey the thin strip material W sandwiched between them. The conveying units 20 are arranged upstream and downstream of the rotary die cutter 30. The material recovery unit 40 has a rotating shaft 41 rotatable in the direction of the arrow so that the thin strip material W' after punching can be wound up and recovered.

[0017] As shown in FIG. 1 and FIGS. 3A to 3D, the rotary die cutter 30 includes an anvil roll 32 and a die roll 34. The anvil roll 32 includes an anvil roll body 32A and an anvil roll elastic layer (anvil-side elastic layer) 32B. The anvil roll body 32A is a cylindrical metal roll rotatable about a rotation axis A1. The anvil roll elastic layer 32B is fixed to an outer circumferential surface 32As of the anvil roll body 32A. The anvil roll 32 rotates in the direction of the arrow about the rotation axis A1 of the anvil roll body 32A while supporting the thin strip material W by the anvil roll elastic layer 32B. The die roll 34 includes a die roll body 34A and a die roll elastic layer 34B. The die roll body 34A is a cylindrical metal roll rotatable about a rotation axis A2 parallel to the rotation axis A1 of the anvil roll body 32A, and has cutting blades 34Ac projecting from its outer circumferential surface 34As, each having a shape corresponding to the periphery of the thin strip M. The die roll elastic layers 34B are fixed to both sides of the cutting blades 34Ac on the outer circumferential surface 34As of the die roll body 34A (except for the portions where the cutting blades 34Ac are provided). The die roll 34 rotates in the direction of the arrow around the rotation axis A2 of the die roll body 34A, supporting the thin strip W by the die roll elastic layers 34B.

[0018] In the rotary die cutter 30, to prevent the cutting blades 34Ac of the die roll 34 from contacting the outer peripheral surface 32As of the anvil roll body 32A and damaging the cutting blades 34Ac, the shortest distance d between the outer peripheral surface 32As of the anvil roll body 32A and the outer peripheral surface 34As of the die roll body 34A (hereinafter sometimes abbreviated as "shortest distance between roll bodies") is longer than the height h of the cutting blades 34Ac. Also, to ensure that the cutting blades 34Ac of the die roll 34 can be pressed reliably into the cutting position Wp of the thin strip material W in the punching process, the shortest distance d between the roll bodies is shorter than the sum of the height h of the cutting blades 34Ac and the thickness t1 of the anvil roll elastic layer 32B. Furthermore, the thickness t2 of the die roll elastic layer 34B is longer than the height h of the cutting edge 34Ac of the die roll 34 so that both sides of the cutting position Wp of the thin strip material W can be securely held between the anvil roll elastic layer 32B and the die roll elastic layer 34B when the cutting edge 34Ac of the die roll 34 is pressed into the cutting position Wp of the thin strip material W during the punching process.

[0019] In addition, in the rotary die cutter 30, the angle θ of the cutting edge of the cutting blade 34Ac of the die roll 34, the shortest distance d between the roll bodies, the height h of the cutting blade 34Ac of the die roll 34, the thickness t1, hardness, and Young's modulus of the anvil roll elastic layer 32B, and the thickness t2, hardness, and Young's modulus of the die roll elastic layer 34B are set so that the bending angle 180°-α of the thin strip material W is controlled so that the magnitude of the tensile stress due to bending applied to the thin strip material W is 2500 MPa or more during the punching process, and the bending back angle β-α of the thin strip material W is controlled so that the magnitude of the tensile stress due to bending applied to the thin strip material W is 2500 MPa or more.

[0020] In the thin strip manufacturing method according to the first embodiment, the thin strip M is manufactured by punching the thin strip W from the thin strip W using the punching device 1 according to the first embodiment. Specifically, as shown in Figs. 3A to 3D, the thin strip W placed on the outer peripheral surface 32Bs of the anvil roll elastic layer (anvil-side elastic layer) 32B on the die roll side is sandwiched between the outer peripheral surface 32Bs of the anvil roll elastic layer 32B and the outer peripheral surface 34Bs of the die roll elastic layer 34B, while the anvil roll 32 and the die roll 34 are rotated in opposite directions as shown by the arrows. This causes the thin strip W to pass between the outer peripheral surface 32Bs of the anvil roll elastic layer 32B and the outer peripheral surface 34Bs of the die roll elastic layer 34B. At this time, while the anvil roll elastic layer 32B and the die roll elastic layer 34B are elastically deformed while being in contact with the anvil roll side surface and the die roll side surface of the thin strip material W, respectively, the cutting blade 34Ac of the die roll 34 is protruded from the outer peripheral surface 34Bs of the die roll elastic layer 34B to push the thin strip material W into the cutting position Wp, and then the cutting blade 34Ac of the die roll 34 is separated from the cutting position Wp of the thin strip material W. In this way, the thin strip material W is cut at the cutting position Wp, and a thin strip piece M is punched out from the thin strip material W (punching process).

[0021] When cutting the thin strip material W at the cutting position Wp, as shown in Fig. 4(a), the cutting blade 34Ac of the die roll 34 is brought into contact with the cutting position Wp of the thin strip material W, and then, as shown in Fig. 4(b), the cutting blade 34Ac of the die roll 34 is pressed into the cutting position Wp of the thin strip material W, and at the same time, the pressing force of the cutting blade 34Ac is applied to the cutting position Wp of the thin strip material W, and at the same time, the elastic force of the anvil roll elastic layer 32B is applied to both sides of the cutting position Wp of the thin strip material W, thereby applying a bending tensile stress to the anvil roll side of the cutting position Wp of the thin strip material W. At this time, the shortest distance d between the roll bodies, the height h of the cutting blade 34Ac, the thickness t1, hardness, Young's modulus, etc. of the anvil roll elastic layer 32B are set as described above, so that the elastic force of the anvil-side elastic layer 32B is suitably set. In addition, by setting the cutting edge angle θ of the cutting blade 34Ac as described above, the bending angle 180°-α at the cutting position of the thin strip material W is suitably controlled, and the magnitude of the tensile stress due to bending is 2500 MPa or more.

[0022] 4(c), when the cutting blade 34Ac of the die roll 34 is pulled away from the cutting position Wp of the thin ribbon material W, the elastic force of the anvil roll elastic layer 32B is applied to the cutting position Wp of the thin ribbon material W, while the elastic force of the die roll elastic layer 34B is applied to both sides of the cutting position Wp of the thin ribbon material W, thereby applying a tensile stress due to bending back to the die roll side of the cutting position Wp of the thin ribbon material W. At this time, the shortest distance d between the roll bodies, the height h of the cutting blade 34Ac, the thickness t1, hardness, Young's modulus, etc. of the anvil roll elastic layer 32B, and the thickness t2, hardness, Young's modulus, etc. of the die roll elastic layer 34B are set as described above, so that the elastic forces of the anvil roll elastic layer 32B and the die roll elastic layer 34B are suitably set. As a result, the bending back angle β-α at the cutting position of the thin ribbon material W is suitably controlled, and the magnitude of the tensile stress due to bending back is 2500 MPa or more. As described above, by continuously applying a tensile stress of 2500 MPa or more due to bending and a tensile stress of 2500 MPa or more due to unbending to the cutting position Wp of the ribbon material W, the ribbon material W is cut at the cutting position Wp.

[0023] In the method for manufacturing a thin strip according to the first embodiment, the anvil roll 32 and the die roll 34 are continuously rotated to continuously cut the thin strip material W at the cutting position Wp by the above-described process, thereby punching out the thin strip material W into a thin strip M. In this way, the thin strip material W is manufactured.

[0024] (Second embodiment) Fig. 5 is a side view schematically showing a punching device according to the second embodiment, and Fig. 6 is a cross-sectional view schematically showing the steps of a main part of a method for producing a thin strip according to the second embodiment.

[0025] As shown in FIG. 5, a punching device 51 according to the second embodiment includes a material supply unit 60, a conveying unit 70, a rotary die cutter 80, and a material recovery unit 90. In the punching device 51, a material sheet L including an elastic sheet (anvil-side elastic layer) E and a thin ribbon material W placed on the die-roll-side surface Es of the elastic sheet E is supplied from the material supply unit 60. The thin ribbon material W is an amorphous alloy thin ribbon. The material sheet L supplied from the material supply unit 60 is conveyed by the conveying unit 70 to the rotary die cutter 80, which then punches out the thin ribbon piece M shown in FIG. 2 from the thin ribbon material W of the material sheet L. The material sheet L' after punching is conveyed by the conveying unit 70 to the material recovery unit 90 and recovered by the material recovery unit 90.

[0026] The material supply unit 60 has a rotary shaft 61 rotatable in the direction of the arrow so that it can unwind and supply the material sheet L to the rotary die cutter 80, and the material sheet L is wound around the rotary shaft 61. The conveying unit 70 has a pair of conveying rolls 71 that rotate with the material sheet L sandwiched between them. The pair of conveying rolls 71 are arranged so that their rotation axes are parallel to each other, and rotate in opposite directions as shown by the arrows to convey the material sheet L sandwiched between them. The conveying units 70 are arranged upstream and downstream of the rotary die cutter 80. The material recovery unit 90 has a rotary shaft 91 rotatable in the direction of the arrow so that it can wind up and recover the material sheet L' after punching.

[0027] As shown in FIGS. 5 and 6, the rotary die cutter 80 includes an anvil roll 82 and a die roll 84. The anvil roll 82 includes an anvil roll body 32A. The anvil roll body 32A is similar to the anvil roll body 32A shown in FIG. 3A. The anvil roll 82 rotates in the direction of the arrow around a rotation axis A1 while supporting the material sheet L from the elastic sheet side by the anvil roll body 32A. The die roll 84 has a configuration similar to that of the die roll 34 shown in FIG. 3A. The die roll 84 rotates in the direction of the arrow around a rotation axis A2 of the die roll body 34A while supporting the material sheet L from the thin strip side by the die roll elastic layer 34B.

[0028] In the rotary die cutter 80, the shortest distance d between the roll bodies is longer than the height h of the cutting blade 34Ac, similar to the rotary die cutter 30 shown in Fig. 3A. Furthermore, the shortest distance d between the roll bodies is shorter than the sum of the height h of the cutting blade 34Ac and the thickness t3 of the elastic sheet E so that the cutting blade 34Ac of the die roll 84 can be pressed into the cutting position Wp of the thin strip material W in the punching process. Furthermore, similar to the rotary die cutter 30 shown in Fig. 3A, the thickness t2 of the die roll elastic layer 34B is longer than the height h of the cutting blade 34Ac of the die roll 84.

[0029] In addition, in the rotary die cutter 80, similar to the rotary die cutter 30 shown in FIG. 3A, the angle θ of the cutting edge of the cutting blade 34Ac of the die roll 84, the shortest distance d between the roll bodies, the height h of the cutting blade 34Ac of the die roll 84, the thickness t3, hardness, and Young's modulus of the elastic sheet E, and the thickness t2, hardness, and Young's modulus of the die roll elastic layer 34B are set so that the bending angle 180°-α of the thin strip material W is controlled and the unbending angle β-α of the thin strip material W is controlled.

[0030] 6, in the method for manufacturing a thin strip according to the second embodiment, the anvil roll 82 and the die roll 84 are rotated in opposite directions as shown by the arrows while sandwiching an elastic sheet (anvil-side elastic layer) E included in a material sheet L and a thin strip material W placed on the die-roll-side surface Es of the elastic sheet E between the outer peripheral surface 32As of the anvil roll body 32A and the outer peripheral surface 34Bs of the die roll elastic layer 34B. As a result, the elastic sheet E and the thin strip material W placed on the outer peripheral surface 32As of the anvil roll body 32A pass between the outer peripheral surface 32As of the anvil roll body 32A and the outer peripheral surface 34Bs of the die roll elastic layer 34B. At this time, while the elastic sheet E and the die roll elastic layer 34B are elastically deformed while being in contact with the anvil roll side surface and the die roll side surface of the thin strip material W, respectively, the cutting blade 34Ac of the die roll 84 is protruded from the outer peripheral surface 34Bs of the die roll elastic layer 34B to push the thin strip material W into the cutting position Wp, and then the cutting blade 34Ac of the die roll 84 is separated from the cutting position Wp of the thin strip material W. In this way, the thin strip material W is cut at the desired cutting position Wp, and a thin strip piece M is punched out from the thin strip material W (punching process).

[0031] When cutting the thin ribbon material W at the cutting position Wp, first, the cutting blade 34Ac of the die roll 84 is brought into contact with and pressed against the cutting position Wp of the thin ribbon material W. At the same time, the pressing force of the cutting blade 34Ac is applied to the cutting position Wp of the thin ribbon material W, and at the same time, the elastic force of the elastic sheet E is applied to both sides of the cutting position Wp of the thin ribbon material W, thereby applying a bending tensile stress to the anvil roll side of the cutting position Wp of the thin ribbon material W. At this time, the shortest distance d between the roll bodies, the height h of the cutting blade 34Ac, the thickness t3, hardness, Young's modulus, etc. of the elastic sheet E are set as described above, so that the elastic force of the elastic sheet E is suitably set. In addition, because the angle θ of the cutting edge of the cutting blade 34Ac is set as described above, the bending angle 180°-α at the cutting position of the thin ribbon material W is suitably controlled, and the magnitude of the bending tensile stress is 2500 MPa or more.

[0032] Next, when the cutting blade 34Ac of the die roll 84 is pulled away from the cutting position Wp of the thin ribbon material W, the elastic force of the elastic sheet E is applied to the cutting position Wp of the thin ribbon material W, while the elastic force of the die roll elastic layer 34B is applied to both sides of the cutting position Wp of the thin ribbon material W, thereby applying a tensile stress due to bending back to the die roll side of the cutting position Wp of the thin ribbon material W. At this time, the shortest distance d between the roll bodies, the height h of the cutting blade 34Ac, the thickness t3, hardness, Young's modulus, etc. of the elastic sheet E, and the thickness t2, hardness, Young's modulus, etc. of the die roll elastic layer 34B are set as described above, so that the elastic force of the elastic sheet E and the elastic force of the die roll elastic layer 34B are suitably set. As a result, the bending back angle β-α at the cutting position of the thin ribbon material W is suitably controlled, and the magnitude of the tensile stress due to bending back is 2500 MPa or more. As described above, by continuously applying a tensile stress of 2500 MPa or more due to bending and a tensile stress of 2500 MPa or more due to unbending to the cutting position Wp of the ribbon material W, the ribbon material W is cut at the cutting position Wp.

[0033] In the method for manufacturing a thin strip according to the second embodiment, the anvil roll 82 and the die roll 84 are continuously rotated, and the thin strip W is continuously cut at the cutting position Wp in the above-described process, thereby punching out the thin strip M from the thin strip W. In this way, the thin strip M is manufactured from the thin strip W.

[0034] (Action and effect) Therefore, according to the method for manufacturing a thin strip according to the embodiment, unlike the conventional method of punching a thin strip by shearing or cutting a thin strip with a cutting blade, as in the first and second embodiments, a tensile stress due to bending and a tensile stress due to unbending are successively applied to the cutting position of the thin strip, thereby cutting the thin strip at the cutting position, thereby manufacturing a thin strip from the thin strip. Therefore, damage to the rotary die cutter can be suppressed.

[0035] Next, details of each component in the method for manufacturing a thin strip according to the embodiment will be described.

[0036] 1. Rotary die cutter The rotary die cutter includes an anvil roll and a die roll. The anvil roll includes an anvil roll body, and the die roll includes a die roll body having a cutting blade projecting from an outer circumferential surface thereof, the cutting blade having a shape corresponding to the periphery of the thin strip, and die roll elastic layers provided on both sides of the cutting blade on the outer circumferential surface of the die roll body.

[0037] The rotary die cutter is not particularly limited as long as it includes an anvil roll and a die roll and can be used in the method for producing a thin strip according to the embodiment, but for example, like the rotary die cutter according to the first embodiment, the anvil roll may further include the anvil roll elastic layer provided on the outer peripheral surface of the anvil roll main body, and the anvil-side elastic layer may be the anvil roll elastic layer. Furthermore, the rotary die cutter may also be, for example, like the rotary die cutter according to the second embodiment, where the anvil roll does not include the anvil roll elastic layer. In such a cutter, the anvil-side elastic layer is an elastic sheet independent of the rotary die cutter.

[0038] The anvil roll body of the anvil roll is a cylindrical member rotatable about a rotation axis. The outer peripheral surface of the anvil roll body is not particularly limited and is usually a cylindrical surface. However, for example, it may be a smooth cylindrical surface without irregularities, or it may have protrusions and recesses for fixing the anvil roll elastic layer. The material of the anvil roll body is not particularly limited, but is usually a metal. Examples of the material of the anvil roll body include alloy tool steel (material code: SKD) and high-speed tool steel (material code: SKH) for cold forming dies specified in Japanese Industrial Standard JIS G 4403:2015, and high-speed tool steel (material code: HAP) manufactured by Hitachi Metals, Ltd.

[0039] The anvil roll elastic layer of the anvil roll is not particularly limited as long as it is provided on the outer peripheral surface of the anvil roll body, but it is, for example, fixed to the outer peripheral surface of the anvil roll body by adhesive, welding, mechanical bonding, or a combination of these. The type of the anvil roll elastic layer is not particularly limited, but examples include non-foamed resin sheets made of non-foamed resins such as urethane, rubber, and PET. The type of elastic sheet separated from the rotary die cutter is also the same as the type of the anvil roll elastic layer.

[0040] The die roll body of the die roll is a cylindrical member rotatable about a rotation axis, with cutting blades protruding from its outer circumferential surface. The rotation axis of the die roll body is not particularly limited, but is usually parallel to the rotation axis of the anvil roll body. The outer circumferential surface of the die roll body is not particularly limited, but is usually a cylindrical surface, and may be, for example, a smooth cylindrical surface without irregularities. The constituent material of the die roll body is the same as that of the anvil roll body, and therefore, a description thereof will be omitted here. The cutting blades of the die roll body have a shape corresponding to the periphery of the thin strip. Here, "having a shape corresponding to the periphery of the thin strip" means that the shape of the cutting edge of the cutting blade when the outer circumferential surface of the die roll body is developed into a plane is the same as the periphery of the thin strip. The cutting blades may be part of the die roll body, or may be a member made of a hard material such as metal separate from the die roll body.

[0041] The die roll elastic layer of the die roll is not particularly limited as long as it is provided on both sides of the cutting blade on the outer peripheral surface of the die roll body, and is, for example, fixed to the outer peripheral surface of the die roll body by adhesive bonding, welding, mechanical bonding, or a combination thereof. The type of the die roll elastic layer is not particularly limited, and examples thereof include a foam sheet or sponge sheet made of a foamed resin such as urethane or ethylene vinyl acetate (EVA).

[0042] In a rotary die cutter, the shortest distance d between the roll bodies (the shortest distance between the outer peripheral surface of the anvil roll body and the outer peripheral surface of the die roll body) is not particularly limited, but is usually longer than the height h of the cutting edges of the die roll, as in the first and second embodiments. The shortest distance d between the roll bodies is not particularly limited, but is usually shorter than the sum of the height h of the cutting edges and the thicknesses t1 and t3 of the anvil-side elastic layer, as in the first and second embodiments. The thickness t2 of the die roll elastic layer is not particularly limited, but is preferably longer than the height h of the cutting edges of the die roll, as in the first and second embodiments.

[0043] The "shortest distance d between the roll bodies" refers to the distance between the outer peripheral surface of the anvil roll body and the outer peripheral surface of the die roll body in a line perpendicular to the rotation axis of the anvil roll body and the rotation axis of the die roll body. The "height h of the die roll cutting blade" refers to the dimension from the base end of the cutting blade on the outer peripheral surface side of the die roll body to the cutting edge in the radial direction of the die roll body. The "thickness t1, t3 of the anvil side elastic layer" refers to the dimension of the anvil side elastic layer in the radial direction of the anvil roll body when it is not elastically deformed. The "thickness t2 of the die roll elastic layer" refers to the dimension of the die roll elastic layer in the radial direction of the die roll body when it is not elastically deformed.

[0044] The hardness of the anvil-side elastic layer is not particularly limited, but is preferably harder than the die roll elastic layer, and more preferably at least three times the hardness of the die roll elastic layer. This is because supporting the thin strip with a hard anvil-side elastic layer can suppress deformation and slippage of the thin strip, while the soft die roll elastic layer can impart sufficient elastic force to the thin strip. Here, the hardness of the anvil-side elastic layer and the die roll elastic layer refers to a value measured by a method specified in, for example, Japanese Industrial Standards JIS K 6253-3:2012 or JIS K 7312:1996. That is, the hardness of the anvil-side elastic layer and the die roll elastic layer is, for example, a Type A durometer hardness (Shore A).

[0045] 2. Punching process In the punching process, the rotary die cutter is used to cut the thin strip material placed on the die roll side surface of the anvil side elastic layer arranged on the outer peripheral surface of the anvil roll body at the desired cutting position as the thin strip material passes between the anvil roll and the die roll, thereby punching out the thin strip pieces from the thin strip material.

[0046] When the anvil roll further includes an anvil roll elastic layer provided on the outer peripheral surface of the anvil roll body and the anvil-side elastic layer is the anvil roll elastic layer, in the punching process, the thin strip material placed on the outer peripheral surface of the anvil roll elastic layer on the die roll side is sandwiched between the anvil roll elastic layer and the die roll elastic layer while the anvil roll and the die roll are rotated in opposite directions to each other, thereby passing the thin strip material between the anvil roll elastic layer and the die roll elastic layer.

[0047] When the anvil-side elastic layer is an elastic sheet independent of the rotary die cutter, in the punching process, the elastic sheet and the thin strip material placed on the surface of the elastic sheet facing the die roll are sandwiched between the anvil roll body and the die roll elastic layer while the anvil roll and the die roll are rotated in opposite directions to each other, thereby passing the elastic sheet and the thin strip material between the anvil roll body and the die roll elastic layer.

[0048] In the punching process, when the cutting blade of the die roll is pushed into the cutting position of the thin strip material, the elastic force of the anvil side elastic layer is applied to both sides of the cutting position of the thin strip material, thereby applying a bending tensile stress to the cutting position of the thin strip material, and then, when the cutting blade of the die roll is pulled away from the cutting position of the thin strip material, the elastic force of the anvil side elastic layer is applied to the cutting position of the thin strip material, while the elastic force of the die roll elastic layer is applied to both sides of the cutting position of the thin strip material, thereby applying a bending back tensile stress to the cutting position of the thin strip material, thereby cutting the thin strip material at the cutting position.

[0049] In the punching process, when the thin strip material is passed between the anvil roll and the die roll, the elastic force of the anvil-side elastic layer, such as the anvil roll elastic layer, and the elastic force of the die roll elastic layer may act on the thin strip material before the cutting blade of the die roll is pressed into the cutting position of the thin strip material, as shown in FIG. 4( a). Furthermore, as shown in FIG. 4( b), when the cutting blade of the die roll is pressed into the cutting position of the thin strip material, the elastic force of the anvil-side elastic layer may act on the cutting position of the thin strip material, or the elastic force of the die roll elastic layer may act on both sides of the cutting position of the thin strip material. Furthermore, as shown in FIG. 4( c), when the cutting blade of the die roll is pulled away from the cutting position of the thin strip material, the elastic force of the anvil-side elastic layer may act on both sides of the cutting position of the thin strip material. These elastic forces of the elastic layers acting on each part of the thin strip material at each timing also affect the magnitude of the tensile stress due to bending and the tensile stress due to unbending.

[0050] The magnitude of the tensile stress due to bending is not particularly limited as long as the ribbon can be cut at the cutting position and varies depending on the type and thickness of the ribbon. However, for example, if the ribbon is an amorphous alloy ribbon, it is preferably in the range of 2500 MPa or more. This is because the ribbon can be reliably cut and ribbon pieces can be reliably punched out from the ribbon. The magnitude of the tensile stress due to unbending is not particularly limited as long as the ribbon can be cut at the cutting position and varies depending on the type and thickness of the ribbon. However, for example, if the ribbon is an amorphous alloy ribbon, it is preferably in the range of 2500 MPa or more. This is because the ribbon can be reliably cut and ribbon pieces can be reliably punched out from the ribbon. Note that the "magnitude of the tensile stress due to bending" refers to the magnitude of the maximum tensile stress among the tensile stresses due to bending applied to the cutting position of the ribbon. The "magnitude of the tensile stress due to unbending" refers to the magnitude of the maximum tensile stress among the tensile stresses due to unbending applied to the cutting position of the ribbon.

[0051] The method for adjusting the magnitude of the tensile stress due to bending is not particularly limited, but examples include a method for adjusting the magnitude of the tensile stress due to bending by controlling the bending angle 180°-α at the cutting position of the ribbon material as shown in Figure 4(b). Here, the "bending angle 180°-α" refers to the angle obtained by subtracting the angle α on the die roll side from 180° between adjacent portions of the ribbon material across the cutting position when the bending at the cutting position of the ribbon material is at its maximum. In this method, the magnitude of the tensile stress due to bending can be increased by increasing the bending angle 180°-α, and the magnitude of the tensile stress due to bending can be decreased by decreasing the bending angle 180°-α.

[0052] Conditions that can be set to control the bending angle 180°-α include, but are not limited to, the angle θ of the cutting edge of the die roll cutting blade, the shortest distance d between the roll bodies, the height h of the die roll cutting blade, and the thicknesses t1 and t3, hardness, and Young's modulus of the anvil-side elastic layer.

[0053] When the cutting edge angle θ of the cutting blade is set, the thin strip bends along the cutting edge angle θ of the cutting blade, so the bending angle 180°-α can be increased by reducing the cutting edge angle θ, and the bending angle 180°-α can be decreased by increasing the cutting edge angle θ. Furthermore, when the shortest distance d between the roll bodies, the height h of the die roll cutting blade, and the thicknesses t1 and t3 of the anvil-side elastic layer are set, if the shortest distance d between the roll bodies is shorter than the sum of the cutting edge height h and the anvil-side elastic layer thicknesses t1 and t3, the difference between the shortest distance d between the roll bodies and the sum of the cutting edge height h and the anvil-side elastic layer thicknesses t1 and t3 can be increased to increase the elasticity of the anvil-side elastic layer, thereby increasing the bending angle 180°-α. Furthermore, when the hardness or Young's modulus of the anvil-side elastic layer is set, the elasticity of the anvil-side elastic layer can be increased by increasing the hardness or Young's modulus.

[0054] The method for adjusting the magnitude of the tensile stress due to bending back is not particularly limited, but examples include a method for adjusting the magnitude of the tensile stress due to bending back by controlling the bending back angle β-α at the cutting position of the ribbon material as shown in Figure 4(c). Here, the "bending back angle β-α" refers to the angle obtained by subtracting the angle α from the angle β on the die roll side, among the angles formed between adjacent portions of the ribbon material across the cutting position when the bending back at the cutting position of the ribbon material is at its maximum. In this method, the magnitude of the tensile stress due to bending back can be increased by increasing the bending back angle β-α, and the magnitude of the tensile stress due to bending back can be reduced by decreasing the bending back angle β-α.

[0055] Conditions that can be set to control the bending back angle β-α are not particularly limited, but include, for example, the shortest distance d between the roll bodies, the height h of the cutting edge of the die roll, the thicknesses t1 and t3, hardness, and Young's modulus of the anvil-side elastic layer, and the thickness t2, hardness, and Young's modulus of the die roll elastic layer.

[0056] When setting the minimum distance d between the roll bodies, the height h of the die roll cutting edges, and the thicknesses t1 and t3 of the anvil-side elastic layer, if the minimum distance d between the roll bodies is shorter than the sum of the height h of the cutting edges and the thicknesses t1 and t3 of the anvil-side elastic layer, the difference between the minimum distance d between the roll bodies and the sum of the height h of the cutting edges and the thicknesses t1 and t3 of the anvil-side elastic layer can be increased to increase the elastic force of the anvil-side elastic layer and thereby increase the unbending angle β-α. Furthermore, when setting the hardness or Young's modulus of the anvil-side elastic layer, the elastic force of the anvil-side elastic layer can be increased by increasing the hardness or Young's modulus. Furthermore, when setting the thickness t2 of the die roll elastic layer, the thickness t2 of the die roll elastic layer can be increased to increase the elastic force of the die roll elastic layer and thereby increase the unbending angle β-α. Furthermore, when setting the hardness or Young's modulus of the die roll elastic layer, the elastic force of the die roll elastic layer can be increased by increasing the hardness or Young's modulus.

[0057] 3.Method of manufacturing thin strips The method for manufacturing a thin strip is a method for manufacturing a thin strip by punching the thin strip from a thin strip material using the rotary die cutter, and includes the punching step.

[0058] The thin ribbon material is not particularly limited as long as it can be punched into thin ribbon pieces, but a material having a Vickers hardness in the range of 300 HV to 900 HV is preferred, and amorphous alloy ribbons are particularly preferred, as this can more effectively prevent damage to the rotary die cutter. Note that "Vickers hardness" refers to the Vickers hardness of the thin ribbon material when, for example, a Vickers hardness test according to JIS Z2244 (2009) is performed with a test force of 0.01 kgf and a load holding time of 10 seconds.

[0059] The thickness of the ribbon material is not particularly limited as long as it is possible to punch out a ribbon piece, and varies depending on the type of ribbon material. For example, in the case of an amorphous alloy ribbon, the thickness is within the range of 0.025 mm to 0.030 mm.

[0060] The thin strips are not particularly limited, but examples thereof include thin strips that form each layer of a laminated core such as a stator core or rotor core in a motor for use in an automobile, and thin strips that are further divided in the circumferential direction. [Example]

[0061] Hereinafter, the method for producing a thin strip according to the embodiment will be described in more detail with reference to examples and test examples.

[0062] [Example] First, the method for manufacturing a ribbon according to the first embodiment was implemented by CAE (Computer Aided Engineering) simulation. Specifically, a calculation model of a rotary die cutter was created by modeling the following configuration. In addition, a calculation model of a ribbon material was created by modeling an amorphous alloy ribbon (thickness: predetermined value) of an actual product.

[0063] (Configuration of rotary die cutter) Outer diameter of the anvil roll body: specified value Thickness t1 of the anvil roll elastic layer: predetermined value Hardness of the anvil roll elastic layer (Shore A): specified value Young's modulus of the anvil roll elastic layer: specified value Outer diameter of the die roll body: specified value Thickness t2 of the die roll elastic layer: specified value Hardness of the die roll elastic layer (Shore A): specified value Young's modulus of the die roll elastic layer: specified value Height of die roll cutting edge h: specified value Angle θ of the cutting edge of the die roll: specified value Shortest distance d between roll bodies: specified value

[0064] Next, using predetermined CAE software and a calculation model of the rotary die cutter and the thin strip material, the process of punching thin strip pieces from the thin strip material under predetermined punching conditions was analyzed (punching process).

[0065] 4(a) to 4(c) show the stress distribution at each stage of the cutting process near the cutting position of the ribbon material, obtained by analysis using CAE simulation in the embodiment. As shown in FIGS. 4(a) to 4(c), the analysis results of the cutting process near the cutting position of the ribbon material show that, when the die roll cutting blade is pushed into the cutting position of the ribbon material, tensile stress due to bending is applied to the anvil roll side of the cutting position of the ribbon material, and then, when the die roll cutting blade is pulled away from the cutting position of the ribbon material, tensile stress due to bending back is applied to the die roll side of the cutting position of the ribbon material. Furthermore, the analysis results show that the magnitude of the tensile stress due to bending is 2500 MPa or more on the surface facing the anvil roll, and the magnitude of the tensile stress due to bending back is 2500 MPa or more on the surface facing the die roll.

[0066] Next, the method for manufacturing a ribbon according to the first embodiment was carried out using an actual machine under the same conditions as those used in the CAE simulation. Specifically, first, a rotary die cutter was prepared. The configuration of the rotary die cutter was the same as that modeled in the calculation model of the rotary die cutter. Furthermore, an amorphous alloy ribbon of an actual product identical to that modeled in the calculation model of the ribbon material was prepared as the ribbon material.

[0067] Next, a test was conducted to punch out thin ribbon pieces from the amorphous alloy ribbon of the actual product using an actual rotary die cutter under the same punching conditions as in the CAE simulation (punching process).As a result, it was possible to punch out thin ribbon pieces from the ribbon material and produce the thin ribbon pieces.

[0068] 7(a) to 7(d) are cross-sectional images showing each stage of the cutting process near the cutting position of the ribbon material observed when the ribbon manufacturing method according to the first embodiment was carried out on an actual machine. Note that these cross-sectional images were photographed using a predetermined photographing method. As shown in FIGS. 7(a) to 7(d), when the ribbon manufacturing method of the example was carried out on an actual machine, the ribbon material bent at the cutting position when the die roll cutting blade (not shown) was pushed into the cutting position of the ribbon material, and returned to its original state at the cutting position of the ribbon material when the die roll cutting blade was pulled away from the cutting position of the ribbon material. Then, when the ribbon material bent at the cutting position, the ribbon material was not cut at the cutting position, and when the bend returned to its original state at the cutting position of the ribbon material, a crack occurred in the ribbon material from the die roll side, and the ribbon material was cut at the cutting position.

[0069] Considering the above-mentioned results, when the ribbon manufacturing method according to the first embodiment is implemented using an actual machine, it is considered that tensile stress due to bending and tensile stress due to unbending are continuously applied to the cutting position of the ribbon material, and when the ribbon material returns to its original state, the ribbon material is cut at the cutting position. It is considered that such continuous cutting at the cutting position of the ribbon material allows ribbon pieces to be punched out from the ribbon material. Furthermore, from the above-mentioned results, it is considered that when the ribbon material is the amorphous alloy ribbon of the above-mentioned actual product, if the magnitude of the tensile stress due to bending is 2500 MPa or more and the magnitude of the tensile stress due to unbending is 2500 MPa or more, the ribbon material can be reliably cut at the cutting position and ribbon pieces can be reliably punched out from the ribbon material.

[0070] [Test Example 1-1] A rotary die cutter was used in which the shape of the cutting blades protruding from the outer peripheral surface of the die roll body corresponded to the periphery of a thin strip different from that of the thin strip M shown in Fig. 2, and a laminated material (thickness: 0.12 mm) in which a polypropylene layer, an aluminum layer, and a polypropylene layer were laminated in this order was used as the thin strip material, but the manufacturing method of the thin strip was carried out in the same manner as in embodiment 1. In this case, the conditions of the rotary die cutter were set as shown in Table 1 below.

[0071] [Test Examples 1-2 and 1-3] A method for producing a thin ribbon was carried out in the same manner as in Test Example 1-1, except that the conditions for the rotary die cutter were set as shown in Table 1 below.

[0072] [Test Examples 2-1 to 2-3] The method for manufacturing the thin strip was carried out in the same manner as in Test Example 1-1, except that a thin strip (thickness: 0.30 mm) made of an aluminum layer was used as the thin strip material, and the rotary die cutter conditions were set as shown in Table 1 below.

[0073] [Test Examples 3-1 to 3-3] The method for manufacturing the thin strip was carried out in the same manner as in Test Example 1-1, except that a thin strip (thickness: 0.015 mm) made of an aluminum layer was used as the thin strip material, and the rotary die cutter conditions were set as shown in Table 1 below.

[0074] [Test Examples 4-1 to 4-3] The method for manufacturing the strip pieces was carried out in the same manner as in Test Example 1-1, except that a strip made of a lead layer (thickness: 0.10 mm) was used as the strip material and the rotary die cutter conditions were set as shown in Table 1 below.

[0075] [Test Examples 5-1 to 5-3] The method for manufacturing the strip pieces was carried out in the same manner as in Test Example 1-1, except that a strip made of a lead layer (thickness: 0.05 mm) was used as the strip material and the rotary die cutter conditions were set as shown in Table 1 below.

[0076] [Test Examples 6-1 and 6-2] A method for producing a thin ribbon was carried out in the same manner as in Test Example 1-1, except that the conditions for the rotary die cutter were set as shown in Table 1 below.

[0077] [Test Examples 7-1 and 7-2] A method for producing a thin ribbon was carried out in the same manner as in Test Example 1-1, except that the conditions for the rotary die cutter were set as shown in Table 1 below.

[0078] [Test Examples 8-1 and 8-2] A method for producing a thin ribbon was carried out in the same manner as in Test Example 1-1, except that the conditions for the rotary die cutter were set as shown in Table 1 below.

[0079] [Test Examples 9-1 and 9-2] A method for producing a thin ribbon was carried out in the same manner as in Test Example 1-1, except that the conditions for the rotary die cutter were set as shown in Table 1 below.

[0080] [Test Examples 10-1 and 10-2] A method for producing a thin ribbon was carried out in the same manner as in Test Example 1-1, except that the rotary die cutter conditions were set as shown in Table 1 below.

[0081] [result] The results of punching the ribbon pieces in the ribbon manufacturing method of each test example are shown in Table 1 below, along with the type of ribbon material used in the ribbon manufacturing method of each test example.

[0082] [Table 1]

[0083] As shown in Table 1 above, the cutting edge angle θ of the die roll and the elastic layer of the anvil roll The results of punching the thin strips were changed by changing the settings of the hardness, thickness and Young's modulus of the elastic layer of the die roll. From this, it is considered that by changing the settings of these conditions, the magnitude of the tensile stress due to bending and the magnitude of the tensile stress due to unbending are adjusted, and therefore whether or not the thin strip material can be cut is changed.

[0084] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design modifications can be made without departing from the spirit of the present invention as set forth in the claims. [Explanation of symbols]

[0085] 30 Rotary Die Cutter 32 Anvil Roll 32A Anvil Roll Body 32As outer surface 32B Anvil Roll Elastic Layer 32Bs outer surface 34 Die Roll 34A die roll body 34Ac cutting blade 34As outer surface 34B Die roll elastic layer 34Bs outer surface W Thin strip material Wp cutting position M Thin Strip 80 Rotary Die Cutter 82 Anvil Roll 84 Die Roll L Material Sheet E Elastic sheet Es die roll surface

Claims

1. A method for producing a thin strip by punching the thin strip from a thin strip material using a rotary die cutter equipped with an anvil roll and a die roll, the ribbon material is an amorphous alloy ribbon having a thickness in the range of 0.025 mm or more and 0.030 mm or less, The anvil roll includes an anvil roll body, and the die roll includes a die roll body having a cutting blade having a shape corresponding to the periphery of the thin strip protruding from an outer peripheral surface thereof, and die roll elastic layers provided on both sides of the cutting blade on the outer peripheral surface of the die roll body, The method for manufacturing the thin strip includes a punching step of punching out the thin strip from the thin strip by cutting the thin strip at a desired cutting position when the thin strip is placed on a surface of the die roll side of the anvil-side elastic layer disposed on the outer peripheral surface of the anvil roll body and the thin strip is passed between the anvil roll and the die roll, In the punching step, when the cutting blades of the die roll are pressed into the cutting position of the thin strip, the elastic force of the anvil-side elastic layer is applied to both sides of the cutting position of the thin strip, thereby applying a tensile stress due to bending to the cutting position of the thin strip, and then, when the cutting blades of the die roll are pulled away from the cutting position of the thin strip, the elastic force of the anvil-side elastic layer is applied to the cutting position of the thin strip, while the elastic force of the die roll elastic layer is applied to both sides of the cutting position of the thin strip, thereby applying a tensile stress due to bending back to the cutting position of the thin strip, thereby cutting the thin strip at the cutting position; In the punching step, a bending angle of the ribbon material is controlled so that the magnitude of the tensile stress due to the bending is 2500 MPa or more, and a bending-back angle of the ribbon material is controlled so that the magnitude of the tensile stress due to the bending is 2500 MPa or more, thereby preventing the ribbon material from being cut at the cutting position when the tensile stress due to the bending is applied to the cutting position of the ribbon material, and preventing the ribbon material from being cut at the cutting position when the tensile stress due to the bending-back is applied to the cutting position of the ribbon material, In the rotary die cutter, the bending angle of the thin strip material is controlled so that the magnitude of the tensile stress due to the bending is 2500 MPa or more, and the bending back angle of the thin strip material is controlled so that the magnitude of the tensile stress due to the bending is 2500 MPa or more, and the outer diameters of the anvil roll body and the die roll body, the thickness, hardness, and Young's modulus of the anvil-side elastic layer, the thickness, hardness, and Young's modulus of the die roll elastic layer, the height and cutting edge angle of the die roll, and the shortest distance between the outer peripheral surface of the anvil roll body and the outer peripheral surface of the die roll body are set to predetermined values.

2. The anvil roll further includes the anvil roll elastic layer provided on the outer peripheral surface of the anvil roll body, the anvil-side elastic layer is the anvil roll elastic layer, The method for manufacturing a thin strip piece according to claim 1, characterized in that in the punching process, the thin strip material placed on the outer peripheral surface of the anvil roll elastic layer facing the die roll is sandwiched between the anvil roll elastic layer and the die roll elastic layer while the anvil roll and the die roll are rotated in opposite directions to each other, thereby passing the thin strip material between the anvil roll elastic layer and the die roll elastic layer.

3. the anvil-side elastic layer is an elastic sheet independent of the rotary die cutter, The method for manufacturing a thin strip as described in claim 1, characterized in that in the punching process, the elastic sheet and the thin strip material placed on the surface of the elastic sheet facing the die roll are sandwiched between the anvil roll body and the die roll elastic layer while the anvil roll and the die roll are rotated in opposite directions to each other, thereby passing the elastic sheet and the thin strip material between the anvil roll body and the die roll elastic layer.

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