Cutting device and method for manufacturing multilayer material

Abstract

A cutting device for cutting a multi-layer material sandwiched between a first tool and a second tool, wherein: the first and second tools are arranged such that respective blade parts thereof face one another in a pushing direction; the blade part of the first tool and / or the second tool has an inclined section having a tool inclined surface that is inclined relative to the pushing direction, and also has a protruding section protruding in the pushing direction from the inclined section, the protruding section having a longitudinal wall surface that extends along the pushing direction from the tool inclined surface, and a pressing surface orthogonal to the longitudinal wall surface; and, in a view from the pushing direction, the inclined section overlaps with the tools facing one another.

Description

Technical Field

[0001] The present invention relates to a cutting device for cutting a multilayer material and a multilayer material having a cut end face.

Background Art

[0002] Multilayer materials obtained by coating the surface of a base material with a coating material, such as a plated steel sheet obtained by plating the surface of a steel sheet or a painted steel sheet obtained by painting the surface of a steel sheet, are manufactured and used according to their applications. The reason for coating the base material with a coating material is, for example, in the case of a plated steel sheet used for building materials, automobiles, or home appliances, to improve the corrosion resistance compared to the state of the base material (steel sheet) as it is by the coating material (plating). However, the manufacturing process of parts using a multilayer material as a raw material includes a process of cutting a necessary member from a raw sheet, such as shearing or laser cutting. The cut end face formed by this cutting process includes a sheared surface or a fractured surface where the base material is substantially exposed. At the exposed portion of the base material on the cut end face, the effect obtained by the coating material is not exhibited. For example, when the multilayer material is a plated steel sheet, the corrosion resistance improvement effect by plating cannot be obtained at the exposed portion of the base material on the cut end face, and there is a concern about the occurrence of red rust.

[0003] Therefore, even for parts using a multilayer material as a raw material, in order to exhibit the effect of the coating material on the cut end face as well as on the front and back surfaces coated with the coating material, generally, post-repair (for example, applying a paint containing the main component of plating if it is plating) is required on the cut end face after processing. This requires time and cost. Therefore, a technique for causing a large amount of the coating material to wrap around the cut end face during cutting of the multilayer material to exhibit the effect of the coating material on the cut end face as well as on the front and back surfaces has been studied.

[0004] For example, Patent Document 1 discloses a method for cutting steel plates, in which a steel plate having a coating material is passed between two circular blades for groove forming, which are positioned facing each other vertically and have a tip angle θ of 20 to 70° and a tip radius R of 0.03 to 0.30 mm, thereby forming pressed grooves on the front and back surfaces of the steel strip, the sum of the depths of both sides being 80% or more of the thickness of the steel plate, and then the steel plate is cut by passing it along the grooves between another circular blade, thereby allowing the plating to wrap around to the end face.

[0005] Furthermore, as a cutting tool that takes into account the shape of the cut end surface of a plate material, for example, Patent Document 2 discloses a shearing die consisting of a die having a first shearing blade and a die having a second shearing blade. The die having the second shearing blade is equipped with a third shearing blade behind the second shearing blade, the clearance between the second shearing blade and the first shearing blade being smaller than the clearance between the second shearing blade and the first shearing blade. When shearing a workpiece using such a shearing die, the burrs that are generated when the workpiece is sheared by the first and second shearing blades are removed by the first shearing blade and the third shearing blade, which has an inclined blade surface, thereby removing the burrs without generating any burrs and obtaining a good cut surface. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2004-34183 [Patent Document 2] Japanese Utility Model Publication No. 62-50013 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the steel plate cutting method described in Patent Document 1 above requires two steps: a first step of forming a groove in the plated steel plate while allowing the surface plating to wrap around the end face, and a second step of cutting the plated steel plate, which is time-consuming. Furthermore, since the shear surface and fracture surface created in the second step are not covered with plating, the corrosion resistance of the cut end surface is reduced. In addition, cutting the plated steel plate in the second step may leave protrusions such as burrs in the center of the plate thickness.

[0008] On the other hand, if a workpiece is sheared using the shearing type described in Patent Document 2, it is possible to prevent burrs or rough edges from forming on the cut surface of the workpiece. However, Patent Document 2 does not consider cutting multi-layered materials such as plated steel sheets. In other words, Patent Document 2 does not consider covering the cut surface of the workpiece with a coating material, and it is difficult to achieve the effects obtained by a coating material, such as corrosion resistance, on the cut surface of the workpiece after shearing using the shearing type described in Patent Document 2. Furthermore, when shearing a workpiece using the shearing type described in Patent Document 2, scrap is generated when shearing with the third shearing blade, which presents the problem that it can only be applied to applications where the generation of scrap is acceptable, and also the problem of reduced workpiece yield.

[0009] Therefore, the present invention has been made in view of the above problems, and the object of the present invention is to provide a cutting device and a multilayer material that can exhibit the effect obtained by the covering material on the cut end surface to the same extent as on the front and back surfaces, and that can also satisfy the specifications required for the multilayer material after cutting. [Means for solving the problem]

[0010] To solve the above problems, according to one aspect of the present invention, a cutting device is provided for cutting a multilayer material sandwiched between a first tool and a second tool, wherein the first tool and the second tool are arranged with their respective blades facing each other in the pushing direction, and at least one of the blades of the first tool or the second tool has an inclined portion having a tool inclined surface that is inclined with respect to the pushing direction, a vertical wall surface extending from the tool inclined surface along the pushing direction, and a pressing surface perpendicular to the vertical wall surface, and a projection that protrudes from the inclined portion in the pushing direction, and the inclined portion overlaps with the opposing tool when viewed in the pushing direction.

[0011] The angle of inclination of the tool's inclined surface relative to the pushing direction may be between 15° and 45°.

[0012] Furthermore, the length of the vertical wall surface in the pushing direction may be 0.1 mm or more and 0.8 mm or less.

[0013] The first tool and the second tool may each have an inclined portion and a projection.

[0014] The radius of curvature at the corner where the vertical wall surface and the pressing surface intersect may be 0.1 mm or less.

[0015] The shapes of the first tool and the second tool may be symmetrical.

[0016] Furthermore, in order to solve the above problems, according to another aspect of the present invention, a multilayer material is provided in which the surface of a base material is covered with a covering material, and the multilayer material has a cut end surface along the thickness direction from a first surface to a second surface, the cut end surface sequentially having an inclined surface that is inclined with respect to the thickness direction and a fracture surface, and at least a part of the inclined surface is covered with a covering material that is continuous with the first surface.

[0017] The length of the fracture surface in the thickness direction of such a multilayer material may be 30% or less of the thickness of the multilayer material.

[0018] The first surface of the multi-layer material intersects the inclined surface, the second surface intersects the fracture surface, and the interior angle between the first surface and the inclined surface may be obtuse.

[0019] The coating material may be made of Zn, Al, or an alloy thereof.

[0020] The base material may be steel plate. [Effects of the Invention]

[0021] As described above, according to the present invention, the effects obtained by the covering material on the cut end surface can be exhibited to the same extent as on the front and back surfaces, and the specifications required for the multi-layer material after cutting, such as suppression of burr generation, can also be met. [Brief explanation of the drawing]

[0022] [Figure 1] It is a schematic diagram showing a configuration example of a slitting facility including a slitting device which is an example of a cutting device according to an embodiment of the present invention. The upper side is a plan view and the lower side is a side view. [Figure 2] It is a schematic diagram showing a configuration example of the slitting device according to the same embodiment. [Figure 3] It is a cross-sectional view taken along the cutting line I-I of the slitting device shown in FIG. 2. [Figure 4] It is a partially enlarged view of the upper rotating part and the lower rotating part of the slitting device according to the same embodiment, showing the case where the shapes of a pair of slit blade parts are different. [Figure 5] It is a partially enlarged view of the upper rotating part and the lower rotating part of the slitting device according to the same embodiment, showing the case where a pair of slit blade parts have a vertically symmetric shape. [Figure 6] It is a schematic diagram showing a cutting state when both the first slit blade and the second slit blade are right-angle blades. [Figure 7] It is a schematic diagram showing the cut end face of a plated steel sheet after cutting by a pair of slit blades shown in FIG. 6. [Figure 8] It is a schematic diagram showing a cutting state when the blade part of the first slit blade has an inclined part and a protrusion part and the second slit blade is a right-angle blade. [Figure 9] It is a schematic diagram showing a cutting state when the blade parts of both the first slit blade and the second slit blade have an inclined part and a protrusion part. [Figure 10A] It is a schematic diagram showing an example of the cut end face of a plated steel sheet after cutting by a pair of slit blades shown in FIG. 8 or FIG. 9. [Figure 10B] It is a schematic diagram showing another example of the cut end face of a plated steel sheet after cutting by a pair of slit blades shown in FIG. 8 or FIG. 9. [Figure 11] It is a schematic diagram showing the cross-sectional shape of the blade part of the first slit blade according to the same embodiment. [Figure 12] It is an explanatory diagram showing punching by a punching die of a comparative example. [Figure 13] It is an explanatory diagram showing punching by a punching die of an example. [Figure 14] This graph shows the relationship between the length of the vertical wall surface of the protrusion (protrusion height) H and the limit of the punching depth. [Figure 15] This graph shows the relationship between the length of the vertical wall surface of the protrusion (protrusion height) H and the remaining plating rate on the cut end surface. [Figure 16] This is a cross-sectional photograph of a plated steel sheet punched out using the punching die of the example. [Figure 17] This is a cross-sectional photograph of a plated steel sheet after cutting. [Figure 18] This is a cross-sectional photograph showing the results of an exposure test. [Figure 19] This is a schematic diagram showing an example of the blade portion of a punch (tool) for a press-fit die. [Figure 20] This is a schematic diagram showing an example of the blade section of the shear (tool) of a shear cutting machine. [Modes for carrying out the invention]

[0023] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. In this specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant descriptions will be omitted.

[0024] [1. Cutting device] First, the schematic configuration of a cutting device according to one embodiment of the present invention will be described based on Figures 1 to 5. Figure 1 is a schematic diagram showing one example of the configuration of a slitting facility equipped with a slitting device 100, which is an example of a cutting device according to this embodiment, with a plan view on the upper side and a side view on the lower side. Figure 2 is a schematic diagram showing one example of the configuration of the slitting device 100 according to this embodiment. Figure 3 is a cross-sectional view of the slitting device 100 shown in Figure 2 along the II cutting line. Figure 4 is a partially enlarged view of the upper rotating part 50A and the lower rotating part 50B of the slitting device 100 according to this embodiment, showing the case where the shapes of the pair of slitting blades are different. Figure 5 is a partially enlarged view of the upper rotating part 50A and the lower rotating part 50B of the slitting device 100, showing the case where the pair of slitting blades have an up-and-down symmetrical shape.

[0025] In Figures 4 and 5, the upper rotating section 50A and the lower rotating section 50B are shown only halfway from the center of rotation. In the following explanation, a plated steel sheet S, in which a plating material is applied to the surface of a steel sheet, which is the base material, will be used as an example of a multi-layer material to be cut by the slitting device 100. In Figures 1 to 5, the length direction of the plated steel sheet S is described as the X direction, the width direction of the plated steel sheet S is described as the Y direction, and the thickness direction is described as the Z direction. The Y direction is also the direction in which the plated steel sheet S is passed through. The Z direction is also the direction in which the tool (slitting blade) is pushed in.

[0026] The slitting equipment is a system that cuts a plated steel sheet S, which is to be cut, using a slitting device 100 equipped with a pair of rotating blades. The slitting equipment includes, for example, a payoff reel 10, a tension generating device 20, a tension reel 30, and the slitting device 100, as shown in Figure 1. The plated steel sheet S, wound in a coil, is dispensed from the payoff reel 10, and with tension applied between the payoff reel 10 and the tension generating device 20, the plated steel sheet S is cut by shear force using the slitting device 100. In the slitting device 100 shown in Figure 1, the plated steel sheet S is divided into three sections in the width direction. The plated steel sheet S cut by the slitting device 100 is wound in a coil by the tension reel 30.

[0027] The slitting device 100 includes four pairs of slitting blades 1, 2, 3, and 4, as shown in Figure 2, for example. The slitting device 100 only needs to have at least one pair of slitting blades. Each pair of slitting blades 1, 2, 3, and 4 consists of a first tool, which is a first set of slitting blades 111, 112, 113, and 114, and a second tool, which is a second set of slitting blades 121, 122, 123, and 124. The pairs of first slitting blades 111, 112, 113, and 114 and the second slitting blades 121, 122, 123, and 124 are arranged to face each other in the pushing direction (Z direction), as shown in Figure 4. Furthermore, in each pair of slit blades 1, 2, 3, and 4, the blade portions 111a, 112a, 113a, 114a, 121a, 122a, 123a, and 124a located on the outer edge of the slit blades overlap when viewed from the direction of the rotation axis (X direction) of each slit blade.

[0028] The shapes of the first slit blades 111, 112, 113, and 114 shown in Figures 2 and 4 are different from those of the second slit blades 121, 122, 123, and 124. The blade portions 111a, 112a, 113a, and 114a of the first slit blades 111, 112, 113, and 114a have an inclined portion with a tool inclined surface that is inclined with respect to the pushing direction (Z direction) when viewed from the front, and a projection that protrudes from the inclined portion in the pushing direction. On the other hand, the blade portions 121a, 122a, 123a, and 124a of the second slit blades 121, 122, 123, and 124a are right-angle blades with corners that are approximately right angles. As shown in Figures 2 and 4, the slitting device 100 only needs to have at least one of the first slitting blades 111, 112, 113, 114 and the second slitting blades 121, 122, 123, 124 having a blade portion with an inclined portion and a projection. For example, as shown in Figure 5, the first slitting blades 111, 112, 113, 114 and the second slitting blades 121, 122, 123, 124 may each have a blade portion with an inclined portion and a projection. A detailed explanation of the shape of the blade portions of the slitting blades will be given later.

[0029] The first slitting blades 111, 112, 113, and 114 are supported on the first shaft portion 115 at the center of rotation. The second slitting blades 121, 122, 123, and 124 are supported on the second shaft portion 125 at the center of rotation. As shown in Figure 3, the first shaft portion 115 is rotatably supported at both ends by a pair of support portions 103a and 103b via chocks 105a and 105b, and the second shaft portion 125 is rotatably supported at both ends by a pair of support portions 103a and 103b via chocks 107a and 107b (chocks 105a and 107a on the far side of the paper are not shown). The pair of support portions 103a and 103b are shown in Figure 2. show It is mounted on the frame 101.

[0030] Sleeves 151 and 153 may be provided between the support parts 103a and 103b, along with the first slit blades 111, 112, 113, 114 and the second slit blades 121, 122, 123, 124. Sleeves 151 and 153 are members for adjusting the spacing between the first slit blades 111, 112, 113, 114 and the second slit blades 121, 122, 123, 124. Although sleeves 151 and 153 of different widths are provided in Figure 2, the spacing between the first slit blades 111, 112, 113, 114 and the second slit blades 121, 122, 123, 124 may also be adjusted using only sleeves of the same width.

[0031] Hereinafter, the first slit blades 111, 112, 113, 114 and sleeves 151, 153 supported by the first shaft portion 115 will also be referred to as the upper rotating portion 50A. The second slit blades 121, 122, 123, 124 and sleeves 151, 153 supported by the second shaft portion 125 will also be referred to as the lower rotating portion 50B. The upper rotating portion 50A rotates integrally with the first shaft portion 115. The lower rotating portion 50B rotates integrally with the second shaft portion 125.

[0032] The pair of support parts 103a and 103b are movable in the plate width direction (X direction) by the drive units 104a and 104b. For example, as shown in Figure 2, the pair of support parts 103a and 103b are screwed onto threaded parts 102a and 102b which are installed parallel to the first shaft part 115 and the second shaft part 125. One end of the threaded parts 102a and 102b is connected to the drive units 104a and 104b. By driving the drive units 104a and 104b to rotate the threaded parts 102a and 102b, the support parts 103a and 103b are moved.

[0033] By driving the drive units 104a and 104b and moving the support units 103a and 103b in the plate width direction so that they separate, one end of the first shaft portion 115 and the second shaft portion 125 is detached from the chock. This makes it possible to remove the sleeves 151 and 153, the first slit blades 111, 112, 113, and 114, and the second slit blades 121, 122, 123, and 124 from the first shaft portion 115 and the second shaft portion 125, and to change the slit blades or the sleeves that adjust the spacing between them.

[0034] Furthermore, at the top of the support sections 103a and 103b, there are reduction devices 109a and 109b, respectively, which serve as spacing adjustment sections for adjusting the distance between the first slit blades 111, 112, 113, and 114 and the second slit blades 121, 122, 123, and 124. By tightening the reduction devices 109a and 109b, the distance between the first slit blades 111, 112, 113, and 114 and the second slit blades 121, 122, 123, and 124 can be narrowed.

[0035] In this embodiment, the slitting device 100 adjusts the spacing between the first slitting blades 111, 112, 113, 114 and the second slitting blades 121, 122, 123, 124 according to the thickness of the plated steel sheet S using the reduction devices 109a and 109b. Then, the plated steel sheet S is passed between the upper rotating part 50A and the lower rotating part 50B while they are rotating, and the plated steel sheet S is cut. As the plated steel sheet S passes between the upper rotating part 50A and the lower rotating part 50B, the pair of slitting blades 1, 2, 3, 4 are gradually pushed in the pushing direction (Z direction), and the plated steel sheet S is cut by shear force.

[0036] At this time, the tensile force generated between the cutting edges of the first slit blades 111, 112, 113, and 114 and the cutting edges of the second slit blades 121, 122, 123, and 124 and the plated steel sheet S causes the plating layer on the surface of the plated steel sheet S to penetrate into the cut end, and the cut end is covered with the plating layer. In other words, the plating layer on the surface of the plated steel sheet S follows the movement of the cutting edges 111a, 112a, 113, and 114 of the first slit blades 111, 112, 113, and 114 and the cutting edges 121a, 122a, 123, and 124a of the second slit blades 121, 122, 123, and 124a on the plated steel sheet S as it passes between the upper rotating section 50A and the lower rotating section 50B, causing the plating layer to penetrate into the cut end. As a result, the cut end of the plated steel sheet S is covered with the plating layer.

[0037] The above describes one configuration of the slitting device 100 and the slitting equipment equipped therewith according to this embodiment. In the following description, the first slitting blades 111, 112, 113, and 114 will be referred to as "first slitting blade 110," and the second slitting blades 121, 122, 123, and 124 will be referred to as "second slitting blade 120." Similarly, the blade portions 111a, 112a, 113a, and 114a of the first slitting blade will be referred to as "blade portion 110a," and the blade portions 121a, 122a, 123a, and 124a of the second slitting blade will be referred to as "blade portion 120a."

[0038] [2. Covering the cut end surface with a covering material] Parts made from multilayered materials are manufactured, for example, by cutting the multilayered material with a cutting device and then processing it. In this process, the condition of the cut end surface of the multilayered material differs depending on the shape of the blade of the cutting device used to cut the multilayered material. The following describes in detail the condition of the cut end surface when a plated steel sheet 5, which is an example of a multilayered material, is cut.

[0039] For example, in the slitting device 100 shown in Figure 2, let's assume that the blade portion 11a of the first slitting blade 11 and the blade portion 12a of the second slitting blade 12 are both right-angle blades, as shown in Figure 6. In this case, when a plated steel sheet 5, which has a plating layer 5b covering the upper surface (first surface) and lower surface (second surface) of a base material 5a made of steel, is sandwiched between the first slitting blade 11 and the second slitting blade 12 and pressed, a shear force is applied to the plated steel sheet 5 and it is cut. As shown in Figure 7, the cut end surface 5s at this time has a shear surface and a fracture surface, in that order from the top surface. The shear surface is a smooth surface formed by the movement of the first slitting blade 11 embedded in the plated steel sheet 5, and the fracture surface is the surface where the plated steel sheet 5 fractured, with a crack that occurred in the plated steel sheet 5 as the starting point. As shown in Figure 7, at the cut end surface 5s of the plated steel sheet 5, the plating layer 5b hardly remains on the shear surface, and the base material 5a is exposed on the fracture surface. Therefore, the effects obtained from the plating, which is the coating material, are not realized at such cut ends 5s, and there are concerns about the occurrence of red rust at the cut ends 5s.

[0040] As a result of diligent research, the inventors of this application have found that when cutting with a right-angle blade as shown in Figure 6, the shear surface is small, resulting in less plating spreading from the top and bottom surfaces to the cut end surface before the plated steel sheet 5 is cut. Furthermore, it was found that stress concentrates at the corners of the upper and lower tools, and cracks occur connecting these corners, resulting in an earlier cutting timing and a larger exposed area of ​​the base material 5a (i.e., the fracture surface).

[0041] One possible method for allowing more plating to wrap around to the cut end surface 5s of the plated steel sheet 5 is to give the corners of the blade a predetermined radius of curvature to make them rounded (i.e., R-shaped). By making the corners of the blade R-shaped, when the blade is pressed in, the plating of the plating layer 5b of the plated steel sheet 5 wraps around to the cut end surface 5s along the R-shaped corners of the blade, and the stress concentration at the corners of the tool is also reduced, thus delaying the cutting timing. Therefore, compared to cutting the plated steel sheet 5 using the right-angle blade shown in Figure 6, the plating coverage rate of the cut end surface 5s is increased, and the exposure of the base material 5a is also reduced. However, the cutting timing becomes too late, and the burrs 5c protruding downwards from the fracture surface of the cut end surface 5s become large.

[0042] Another method for allowing more plating to wrap around to the cut end surface 5s of the plated steel sheet 5 is to provide a tapered inclined surface to the blade. In this case as well, when the blade is pressed in, the plating of the plating layer 5b of the plated steel sheet 5 wraps around to the cut end surface 5s along the inclined surface of the blade, resulting in a higher plating coverage rate on the cut end surface 5s compared to when the plated steel sheet 5 is cut using the right-angle blade shown in Figure 6. However, if the corners of the blade are sharp, stress concentration at the corners of the tool is not relieved, and cracks occur connecting these corners. Therefore, the cutting timing is not delayed, and the exposed area of ​​the base material 5a (i.e., the fracture surface) remains large.

[0043] Therefore, the inventors of the present invention have found that by giving at least one of the blade portion 110a of the first slit blade 110 or the blade portion 120a of the second slit blade 120 a shape having an inclined portion and a projection, the plating coverage of the cut end surface 5s of the plated steel sheet 5 can be increased without increasing the size of the burrs. That is, for example, as shown in Figure 8, the blade portion 110a of the first slit blade 110 may have an inclined portion P1 and a projection P2, and the second slit blade 120 may have a right-angle blade. Alternatively, for example, as shown in Figure 9, the blade portion 110a of the first slit blade 110 and the blade portion 120a of the second slit blade 120 may have an inclined portion P1 and a projection P2.

[0044] In both Figure 8 and Figure 9, the inclined portion P1 overlaps with the opposing tool when viewed in the pushing direction (Z direction). For example, in Figure 8, the inclined portion P1 of the blade portion 110a of the first slit blade 110 has an overlapping portion Q that overlaps with the opposing second slit blade 120 when viewed in the pushing direction (Z direction). Also, in Figure 9, the inclined portion P1 of the blade portion 110a of the first slit blade 110 has an overlapping portion Q that overlaps with the opposing second slit blade 120 when viewed in the pushing direction (Z direction), and the inclined portion P1 of the blade portion 120a of the second slit blade 120 has an overlapping portion Q that overlaps with the opposing first slit blade 110 when viewed in the pushing direction (Z direction).

[0045] Figures 10A and 10B show examples of the cut end surfaces 5s of a plated steel sheet 5 cut by the pair of slit blades shown in Figures 8 and 9. Figures 10A and 10B show the cut end surface 5s on the side where the surface (top surface, first surface) opposite the inclined portion P1 of the first slit blade 110 in Figures 8 and 9 is pressed in. As shown in Figure 10A, the cut end surface 5s has an inclined surface, a shear surface, and a fracture surface, in that order from the top surface. The inclined surface is a surface formed along the inclined portion P1 of the blade portion 110a of the first slit blade 110 and is inclined with respect to the thickness direction of the sheet. The shear surface is a smooth surface formed by the movement of the first slit blade 110 embedded in the plated steel sheet 5, and occurs only slightly. The fracture surface is the surface where the plated steel sheet 5 fractured, starting from a crack that occurred in the plated steel sheet 5.

[0046] In the cut plated steel sheet 5, the upper surface (first surface) intersects with the inclined surface. At this time, the interior angle α between the upper surface and the inclined surface is an obtuse angle of approximately θ + 90°, which is the inclination angle (taper angle) of the tool inclined surface described later. The lower surface (second surface) intersects with the fracture surface. Because the plated steel sheet 5 is cut diagonally from the upper surface to the lower surface by the inclined portion P1 of the first slit blade 110, an inclined surface is formed on the cut end surface 5s that slopes in one direction from the upper surface to the lower surface.

[0047] At the cut end surface 5s of the plated steel sheet 5, at least a portion of the inclined surface is covered by a coating material that is continuous from the upper surface (first surface). For example, in the cut end surface 5s of the plated steel sheet 5 shown in Figure 10A, the plating layer 5b on the upper surface wraps around to the inclined surface and covers it. Although the entire inclined surface in Figure 10A is covered by a plating layer 5b that is continuous from the upper surface (first surface), depending on the cutting method, for example, as in the cut end surface 5s of the plated steel sheet 5 shown in Figure 10B, the plating layer 5b on the upper surface that wraps around to the inclined surface may be faded, and the inclined surface may be covered discontinuously by the plating layer 5b. Even in such cases, since there is a portion of the inclined surface covered by a plating layer 5b that is continuous from the upper surface (first surface), the effect of the plating as a coating material can be obtained at the cut end surface 5s. Furthermore, as shown in Figures 10A and 10B, the shear surface where almost no plating remains and the fracture surface where the base material 5a is exposed are minimal at the cut end surface 5s. Therefore, the effect of the plating, which is the coating material, can be obtained even at the cut end surface 5s.

[0048] Furthermore, in the pair of slitting blades shown in Figures 8 and 9, the final cut that produces a fracture surface is made by a projection P2 with a corner that is approximately right-angled, thus suppressing the generation of large burrs. It is desirable that the length of the fracture surface in the thickness direction of the plated steel sheet 5 cut by the pair of slitting blades according to this embodiment be 30% or less of the thickness of the plated steel sheet 5, which is a multi-layer material. This reduces the area in which the base material 5a is exposed at the cut end surface 5s.

[0049] As shown in Figure 8, if the blade portion 110a of the first slit blade 110 has a shape with an inclined portion P1 and a projection P2, and the second slit blade 120 has a right-angle blade, then one of the two cut plated steel sheets 5 will have a cut end surface 5s as shown in Figure 10A or Figure 10B (cut plated steel sheet Sa in Figure 4). However, the cut end surface 5s of the other plated steel sheet 5 will not be coated with plating and will become scrap (cut plated steel sheet Sb in Figure 4). As shown in Figure 9, if the blade portion 110a of the first slit blade 110 and the blade portion 120a of the second slit blade 120 have a shape with an inclined portion P1 and a projection P2, then both of the two cut plated steel sheets 5 can have a cut end surface 5s as shown in Figure 10A or Figure 10B (cut plated steel sheet Sa in Figure 5).

[0050] [3. Blade shape] The shape of the blade portion having the inclined portion P1 and the projection portion P2 will be described in detail below with reference to Figure 11. Figure 11 is a schematic diagram showing the cross-sectional shape of the blade portion 110a of the first slit blade 110 according to this embodiment. Note that Figure 11 shows an enlarged view of the blade portion 110a when the slit blade 110 is cut in a plane including the rotation axis of the first slit blade 110. Note that the blade portion 120a of the second slit blade 120 is tilt Even when the blade has a slanted portion P1 and a projection P2, the shape of the blade portion 120a is the same as in Figure 11. Therefore, the blade portion 110a of the first slit blade 110 will be used as an example for explanation. In addition, plated steel sheet 5 will be used as an example of a multi-layer material to be cut.

[0051] The blade portion 110a having the cross-sectional shape shown in Figure 11 has an inclined portion P1 and a projection portion P2. The inclined portion P1 has a tool inclined surface s1 that is inclined with respect to the pushing direction. The projection portion P2 has a vertical wall surface s2 that extends from the tool inclined surface s1 along the pushing direction and a pressing surface s3 that is perpendicular to the vertical wall surface s2. It is desirable that such a blade portion 110a satisfies the following shape.

[0052] (Inclination angle (taper angle) θ of the tool's inclined surface) The inclination angle (taper angle) θ of the tool's inclined surface s1 with respect to the pushing direction should preferably be between 15° and 45°. If the inclination angle θ is 15° or greater, it is possible to ensure a cutting timing that allows the plating layer 5b of the plated steel sheet 5 to wrap around the inclined surface sufficiently. If the inclination angle θ is around 5°, the cutting timing will be similar to that of a right-angle blade.

[0053] On the other hand, the slit blade 110 is subjected to load not only in the pushing direction (up and down) but also in the axial direction (left and right). However, as the inclination angle θ increases, the axial load (left and right) increases, placing an excessive load on the equipment. If the inclination angle θ is 45° or less, the axial load (left and right) on the slit blade 110 does not become too large, and cutting can be performed within the load capacity of the equipment. If the inclination angle θ is greater than 45°, the increase in the plating wrap-around effect obtained in response to the increase in load becomes not so large. For this reason, it is best to set the inclination angle (taper angle) θ of the tool inclination surface s1 with respect to the pushing direction to 15° or more and 45° or less.

[0054] (Length of vertical wall surface H) The length H of the vertical wall surface s2 in the pushing direction is preferably 0.1 mm or more and less than the thickness of the plated steel sheet 5 to be cut. If the length H of the vertical wall surface s2 is 0.1 mm or more, the burrs that form on the cut end surface 5s of the plated steel sheet 5 after cutting can be kept within an acceptable range. In addition, if the length H of the vertical wall surface s2 is 0.1 mm or more, the processing of the blade portion 110a can be made easier. Furthermore, the blade portion 110a of the slit blade 110 wears down with use. If the length H of the vertical wall surface s2 is 0.1 mm or more, the lifespan of the slit blade 110 due to wear can be extended and the frequency of replacement can be reduced.

[0055] On the other hand, by setting the length H of the vertical wall surface s2 to less than the thickness of the plated steel sheet 5 to be cut, it is possible to avoid cutting in the same way as with a right-angle blade. For example, when considering the cutting of plated steel sheets 5 with a thickness of 1.0 mm to 4.5 mm, the length H of the vertical wall surface s2 should be smaller than the minimum thickness of 1.0 mm, for example, 0.8 mm. If the minimum thickness of the plated steel sheet 5 to be cut is 3.0 mm, the length H of the vertical wall surface s2 should be, for example, 1.6 mm.

[0056] Thus, the length H of the vertical wall surface s2 in the pressing direction should be 0.1 mm or more and less than the thickness of the plated steel sheet 5 to be cut.

[0057] (R of curvature at the corner) The radius of curvature R of the corner c where the vertical wall surface s2 and the pressing surface s3 intersect is preferably 0.1 mm or less. By setting the radius of curvature R of the corner c to 0.1 mm or less, the amount of burr generated can be reduced. For example, the radius of curvature R of the corner c may be around 0.05 mm. The radius of curvature R of the corner c does not depend on the thickness of the plated steel sheet 5 to be cut, and can be set appropriately according to the material of the plated steel sheet 5, etc.

[0058] The blade portion 110a is shaped as described above, and as shown in Figures 8 and 9, the slit blade 110 having the shape of the blade portion 110a is positioned such that, when viewed in the pushing direction, the tool inclined surface s1 overlaps with the opposing slit blade. By cutting the plated steel sheet 5 using such a slit blade 110, the inclined portion P1 of the blade portion 110a compresses the plating of the plating layer 5b, including the base material 5a, in the pushing direction (plate thickness direction), causing it to wrap around to the cut end surface. By applying compressive stress, the cutting timing is delayed, and the inclined surface can be coated with plating. This enhances the effect obtained by the plating, which is the coating material, on the cut end surface. Furthermore, by completely cutting the plated steel sheet 5 with the projection P2 of the blade portion 110a, the generation of large burrs can be suppressed. [Examples]

[0059] (A. Verification by punching process simulating slit cutting) The effectiveness of the present invention was verified by performing a punching process that simulated slit cutting. In this verification, a punching process using a punching die was performed, simulating slit cutting by the slitting device 100 shown in Figure 2. Multilayer The material used was a 400N-grade Zn-Al-Mg ternary alloy plated steel sheet with a thickness of 3.2 mm.

[0060] In the comparative example, a punching die was used, which included a punch 71 with an outer diameter Dp, a die 72 with an inner diameter Dd, and a plate holder 73, as shown in Figure 12. The punch 71 and die 72 had right-angled blades. With the plated steel sheet 5 placed on the die 72 and held down by the plate holder 73, the punch 71 was pushed in from the plate holder 73 side to punch out the plated steel sheet 5.

[0061] In the embodiment, a punching die was used, as shown in Figure 13, comprising a punch 710 with an outer diameter Dp, a die 720 with an inner diameter Dd, and a plate holder 730. The cutting edge of the punch 710 had an inclined portion with an inclination angle θ and a projection with a vertical wall height H. The radius of curvature of the corner of the projection was 0.05 mm. The punch 710 was positioned so that its inclined portion overlapped with the opposing die 720 when viewed in the punching direction. Similar to the comparative example, with the plated steel sheet 5 placed on the die 720 and held down by the plate holder 730, the punch 710 was pushed in from the plate holder 730 side to punch out the plated steel sheet 5.

[0062] (A-1. Timing of fracture) First, using the punching die of the embodiment shown in Figure 13, the relationship between the length of the vertical wall surface of the projection (projection height) H and the punching limit indentation amount was investigated. The punching limit indentation amount is the amount of indentation by the punch 710 from the start of indentation until a crack occurs and the object to be cut breaks. The larger the punching limit indentation amount, the later the breakage timing can be said to be. Here, the length of the vertical wall surface of the projection (projection height) H was changed to 0.1 mm, 0.4 mm, and 0.8 mm for cases where the inclination angle θ of the inclined part is 15°, 30°, and 45°, respectively. The verification results are shown in Figure 14. The dashed line in Figure 14 shows the punching limit indentation amount when using the punching die of the comparative example shown in Figure 12.

[0063] As shown in Figure 14, when processing using the press die of the embodiment, the maximum punching depth can be increased compared to when processing using the press die of the comparative example. Furthermore, it was found that the maximum punching depth increases as the inclination angle θ of the inclined portion increases, and the maximum punching depth increases as the length of the vertical wall surface (projection height) H of the projection decreases. In other words, it was shown that the larger the inclination angle θ of the inclined portion and the lower the length of the vertical wall surface (projection height) H of the projection, the later the timing of fracture of the plated steel sheet 5 due to crack formation.

[0064] (A-2. Plating retention rate on cut ends) Next, using the punching die of the embodiment shown in Figure 13, the relationship between the length of the vertical wall surface of the protrusion (protrusion height) H and the remaining plating rate on the cut end surface was investigated. The remaining plating rate is the ratio of the length of the remaining plating area in the thickness direction (hereinafter also referred to as the "remaining plating area height") Hp [mm] to the thickness t [mm] of the plated steel sheet 5, and is expressed by the following formula (1). In this verification, the cut end surface was analyzed using a scanning electron microscope (SEM) to measure Zn, the main component of the plating, and Fe, the main component of the base material, and the area in which the proportion of Zn was greater than or equal to a predetermined proportion was identified as the remaining plating area. The cut end surfaces to be analyzed were obtained by pressing the plated steel sheet 5 while varying the length of the vertical wall surface of the protrusion (protrusion height) H to 0.1 mm, 0.4 mm, and 0.8 mm, respectively, for cases where the inclination angle θ of the inclined part was 15°, 30°, and 45°.

[0065] Plating retention rate [%] = Hp / t × 100 ... (1)

[0066] The verification results are shown in Figure 15. The dashed line in Figure 15 shows the plating retention rate when using the punching die of the comparative example shown in Figure 12.

[0067] As shown in Figure 15, when processing using the press die of the embodiment, the plating retention rate can be increased compared to when processing using the press die of the comparative example. Furthermore, it was found that the plating retention rate increases as the inclination angle θ of the inclined portion increases, and as the length of the vertical wall surface of the protrusion (protrusion height) H decreases. In other words, it was shown that the plating retention rate increases as the inclination angle θ of the inclined portion increases and as the length of the vertical wall surface of the protrusion (protrusion height) H decreases.

[0068] Furthermore, Figure 16 shows cross-sectional photographs of the plated steel sheet 5 after cutting, as well as the remaining plated area height Hp, when the length of the vertical wall surface of the projection (projection height) H is 0.1 mm and the inclination angle θ of the inclined part is 15°, 30°, and 45°. From Figure 16, it can be seen that when the length of the vertical wall surface of the projection (projection height) H is the same, the remaining plated area height Hp increases as the inclination angle θ of the inclined part increases.

[0069] (B. Verification by slit cutting) Next, a slit cutting test was conducted to verify the effectiveness of the present invention. In this verification, a slit cutting test machine equipped with a pair of slitting blades was used to cut plated steel sheets. The multilayer material to be cut was a 400N class Zn-Al-Mg ternary alloy plated steel sheet with a thickness of 3.2 mm.

[0070] In the comparative example, a plated steel sheet 5 was slit-cut using a slit-cutting test machine equipped with a pair of slit blades, both having right-angled edges, as shown in Figure 6. The clearance between the pair of slit blades was 0.35 mm.

[0071] In this embodiment, a plated steel sheet 5 was slit-cut using a slit-cutting test machine equipped with a pair of slit blades, as shown in Figure 8. One slit blade had a blade portion with an inclined portion at an inclination angle θ and a projection portion with a vertical wall height H, while the other slit blade was a right-angle blade. The inclination angle θ of the inclined portion was 45°, and the vertical wall height H of the projection portion was 0.1 mm. One slit blade was positioned so that its inclined portion overlapped with that of the opposing slit blade when viewed in the direction of insertion.

[0072] Figure 17 shows a cross-sectional photograph of the plated steel sheet 5 after cutting. As shown in Figure 17, the cut end surface of the comparative example has a sag, a shear surface, and a fracture surface from the top side, and it can be seen that the plating of the surface plating layer has not wrapped around to the shear surface and fracture surface. On the other hand, the cut end surface of the embodiment has an inclined surface and a fracture surface from the top side. The shear surface is hardly visible, but it is slightly present between the inclined surface and the fracture surface. It can be seen that the plating of the surface plating layer has wrapped around to the inclined surface of the cut end surface of the embodiment. In addition, there is a slight burr on the bottom side, but it is a minute amount that is acceptable. Thus, it can be seen that when the plated steel sheet is slit-cut using the pair of slit blades of the embodiment, the plating coverage of the cut end surface is higher compared to when the plated steel sheet is slit-cut using the pair of slit blades of the comparative example.

[0073] Furthermore, the inclination angle of the inclined surface of the cut end face in the embodiment is approximately 45°, which is the same as the inclination angle θ of the inclined portion of the slit blade. This demonstrates that the inclined surface of the cut end face is formed by the inclined portion of the slit blade.

[0074] Figure 18 shows the results of exposure tests conducted on plated steel sheets cut with a pair of slitting blades in the comparative example and plated steel sheets cut with a pair of slitting blades in the example. Show the resultsIn the comparative example, the plated steel sheet after cutting had the cut end surface shown in Figure 17, and the plating retention rate was 17.8%. On the other hand, in the examples, two types of plated steel sheets after cutting were prepared by changing the inclination angle θ of the blade portion and the height H of the projection of the vertical wall surface of one of the slit blades shown in Figure 8. In Example 1, an exposure test was conducted using a plated steel sheet after cutting with a slit blade having a blade portion with an inclination angle θ of 30° and a vertical wall surface height H of 0.4 mm. The plating retention rate in Example 1 was 74.1%. In Example 2, an exposure test was conducted using a plated steel sheet after cutting with a slit blade having a blade portion with an inclination angle θ of 45° and a vertical wall surface height H of 0.1 mm. The plated steel sheet after cutting in Example 2 had the cut end surface shown in Figure 17, and the plating retention rate was 69.5%.

[0075] As shown in Figure 18, in the comparative example, red rust formed on the fracture surface two weeks after the start of the exposure test. On the other hand, in Examples 1 and 2, slight red rust formed on the fracture surface four weeks after the start of the exposure test. However, because the fracture surface area was small, the red rust on the cut end was not noticeable, and there were no cosmetic problems.

[0076] Although preferred embodiments of the present invention have been described in detail above with reference to the attached drawings, the present invention is not limited to these examples. It is clear to any person with ordinary skill in the art to which the present invention belongs that various modifications or alterations can be conceived within the scope of the technical idea described in the claims, and these are also understood to fall within the technical scope of the present invention.

[0077] For example, in the above embodiment, a slitting device equipped with a pair of slitting blades as a cutting device was described, but the present invention is not limited to such examples. For example, the cutting device according to the present invention has a first tool and a second tool, and at least one of the blades of the first tool or the second tool has an inclined portion having a tool inclined surface that is inclined with respect to the pressing direction, a vertical wall surface extending from the tool inclined surface along the pressing direction, and a pressing surface perpendicular to the vertical wall surface, and a projection that protrudes from the inclined portion in the pressing direction. In this case, the tools are arranged so that the inclined portions of opposing tools overlap when viewed in the pressing direction. For example, the cutting device may be a press die for punching or a shear cutting machine.

[0078] The press die comprises a punch and a die, as shown in Figure 13, for example. In this case, the punch 200 is shaped as shown in Figure 19, for example. The punch 200 has an inclined portion P1 having a tool inclined surface s1, a vertical wall surface s2 extending from the tool inclined surface s1 along the pressing direction, a pressing surface s3 perpendicular to the vertical wall surface s2, and a projection P2 protruding from the inclined portion P1 in the pressing direction. The cross-sectional shape passing through the central axis of the punch 200 is the same as in Figure 11.

[0079] Alternatively, the shear of the shear cutting machine may be shaped like the shear 300 shown in Figure 20, for example. The shear 300 has an inclined portion P1 having a tool inclined surface s1, a vertical wall surface s2 extending from the tool inclined surface s1 along the pushing direction, a pressing surface s3 perpendicular to the vertical wall surface s2, and a projection P2 protruding from the inclined portion P1 in the pushing direction. The side shape of the shear 300 is the same as in Figure 11.

[0080] Thus, it is sufficient that at least one of the blades of the first tool or the second tool of the cutting device according to this embodiment has a cross-sectional shape as shown in Figure 11.

[0081] In press-fitting dies, it is common to use only one half of the cut multilayer material as the final product, so it is sufficient for either the first or second tool to have a blade with the cross-sectional shape shown in Figure 11. On the other hand, in slitting devices and shear cutting machines, the entire multilayer material after cutting may be used as the final product, so both the first and second tools may have blades with the cross-sectional shape shown in Figure 11.

[0082] Furthermore, although the multilayer material was a plated steel sheet in the above embodiment, the multilayer material can be any material formed by coating the surface of a base material with a coating material. For example, the base material may be not only a steel sheet but also other metal materials, and the coating material may be a material made of Zn, Al or their alloys, an oxide film, a paint material, a resin material, etc. Incidentally, the multilayer material may be a painted steel sheet in which the surface of the metal material that is the base material is painted, or a film-laminated steel sheet in which a film is laminated to a steel sheet. Alternatively, the coating material may be a clad material. For example, the multilayer material may be a Ni-clad copper material in which a Cu sheet is the base material and a Ni sheet is the coating material.

[0083] Furthermore, the coating material constituting the multilayer material is not limited to just one layer, but may consist of multiple layers. For example, the surface of the plated steel sheet described above may be treated with chemical conversion treatment, painting, lamination, or other processes.

[0084] Furthermore, the multilayer material may be a multilayer material in which a resin material such as plastic is used as the base material and a metal material such as Cu, Cr, Ag, Au, or Pt is used as the coating material. When a resin material such as plastic coated with metal is cut, the electrical conductivity of the end surface is lost. Also, if the proportion of exposed resin is high, it becomes prone to static electricity, raising concerns about the generation of sparks, etc. Therefore, by making the cut end surface of such a resin material the same shape as the cut end surface of the multilayer material according to this embodiment, it is possible to improve the electrical conductivity of the cut end surface and prevent static electricity buildup.

[0085] Furthermore, in the case of clad materials, the required purpose when cut varies depending on the combination with the coating material and the application. However, by making the cut end surface similar in shape to that of the multilayer material according to this embodiment, the corrosion resistance, chemical resistance, etc. of the base material can be improved at the cut end surface due to the effect of the coating material. In addition, the electrical conductivity, thermal conductivity, magnetism, etc. of part or the entire cut end surface can be improved compared to conventional cutting methods.

[0086] In the case of coatings and laminates, by making the cut end surface the same shape as the cut end surface of the multilayer material according to this embodiment, it is possible to improve not only the corrosion resistance of the base material at the cut end surface, but also the suppression of blistering under the coating film, the improvement of appearance by suppressing exposure of the base material, and the improvement of the insulation of part or all of the cut end surface.

[0087] Thus, by shaping the cut end of the multilayer material to the shape of the cut end according to this embodiment, the effects obtained by the covering material on the upper and lower surfaces can also be exerted on the cut end. It should be noted that the effects obtained by the covering material are not limited to the examples described above, and may be exerted depending on the application of the covering material. [Explanation of Symbols]

[0088] 5. S-plated steel sheet (multilayer material) 5a Base material 5b Plating layer (coating material) 5c Bali 5s cut end surface 10 Payoffriel 11 First slit blade 11a Cutting edge (of the first slit blade) 12. Second slit blade 12a Cutting edge (of the second slit blade) 20 Tension Generating Device 30 Tension Reels 71, 710 punches 72,720 dice 73, 730 Board holder 100 Slitting device 110 First slit blade 110a Cutting edge (of the first slit blade) 120 Second slit blade 120a (Blade portion of the second slit blade) 200 punches 300 Shar P1 slope part P2 protrusion Q Overlapping part s1 Tool slope s2 Vertical wall surface s3 Pressing surface c corner

Claims

1. A cutting device for cutting a multi-layered material sandwiched between a first tool and a second tool using the first tool and the second tool, The first tool and the second tool are arranged with their respective cutting edges facing each other in the pushing direction. The cutting edge of at least one of the first tool or the second tool is An inclined portion having a tool inclined surface that is inclined with respect to the aforementioned pushing direction, The tool has a vertical wall surface extending from the inclined surface of the tool along the pressing direction, and a pressing surface perpendicular to the vertical wall surface, and a projection that protrudes from the inclined portion in the pressing direction, It has, The aforementioned inclined portion overlaps with the opposing tool when viewed in the pushing direction, in a cutting device.

2. The cutting apparatus according to claim 1, wherein the angle of inclination of the tool inclined surface with respect to the pushing direction is 15° or more and 45° or less.

3. The cutting device according to claim 1, wherein the length of the vertical wall surface in the pushing direction is 0.1 mm or more and 0.8 mm or less.

4. The cutting apparatus according to any one of claims 1 to 3, wherein the first tool and the second tool each comprise the inclined portion and the projection portion.

5. The cutting apparatus according to any one of claims 1 to 3, wherein the radius of curvature of the corner where the vertical wall surface and the pressing surface intersect is 0.1 mm or less.

6. The cutting apparatus according to any one of claims 1 to 3, wherein the shape of the first tool and the shape of the second tool are symmetrical.

7. A method for manufacturing a multilayer material, comprising covering the surface of a base material with a coating material, The material, in which the surface of the base material is covered with the covering material, is cut using the cutting device described in any one of claims 1 to 3, thereby forming a cut end surface along the thickness direction from the first surface toward the second surface. The cut end surface is formed to sequentially have an inclined surface that is inclined with respect to the thickness direction of the plate, and a fracture surface. A method for manufacturing a multilayer material, wherein, by the above cutting, at least a portion of the inclined surface is covered by the covering material that is continuous with the first surface.

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