CUTTING METHOD AND CUT ARTICLE

Abstract

A cutting method is provided for cutting a workpiece using a cutting tool comprising a die and a punch, which includes: arranging the workpiece between the die and the punch and, in a state in which a first wedge-shaped cutting portion of the die and a second wedge-shaped cutting portion of the punch are opposed, pushing the punch relatively towards the side of the die to cut the workpiece; wherein: a front end angle θ1 of the first cutting portion and a front end angle θ2 of the second cutting portion are each 10° or more and 120° or less and a front end radius R1 of the first cutting portion and a front end radius R2 of the second cutting portion are each 0.5% or more and 35.0% or less of the sheet thickness.

Description

CUTTING METHOD AND CUT ITEM TECHNICAL FIELD The present invention relates to a cutting method for cutting a workpiece and a cut article that was cut and formed by the cutting method. BACKGROUND OF THE STATE OF THE ART Various types of surface treated materials are produced according to applications, such as metal coated metal sheet in which the surface of a metal material has been subjected to metal coating treatment or painted metal sheet in which the surface of a metallic material has been painted. For example, metal-coated steel sheets that are excellent in corrosion resistance are used for building materials, automobiles, and home appliance applications. Components using a surface-treated material that were produced by subjecting a workpiece to a surface treatment are manufactured, for example, by cutting the workpiece that was subjected to the surface treatment and subsequently processing the cut workpiece. Cutting a workpiece 5 can be carried out, for example, by cutting the workpiece 5 using a cutting tool 10 as illustrated in Figure 35. The cutting tool 10 is composed of a die 11, a punch 12 and a blank holder 13. For example, in a state where one end of the workpiece 5 is restrained by the die 11 and the blank holder 13, the punch 12 that has been positioned to having a clearance d with respect to the die 11 is moved relative to the side of the die 11 to apply a cutting force to the workpiece 5. In this way, the workpiece 5 is cut. The workpiece 5, which underwent surface treatment, which was cut using the cutting tool 10 illustrated in Figure 35, has a cut end face, as illustrated in Figure 36. The cut end face of The workpiece 5 is composed of a cutting depression, a cutting surface and a fracture surface. Shear depression is a deformation caused by a tensile force acting on the upper surface of the workpiece 5 when, with respect to the workpiece 5 in which the surface of a metallic material 5a as the base material is has been covered with a coating layer 5b, the punch 12, illustrated in Figure 35, is pushed downward from the upper surface side towards the lower surface side of the workpiece 5. The cutting surface is a smooth surface formed by the movement of punch 12 sinking into workpiece 5 MA / I / UOO I ¿ó and the fracture surface is a surface in which the cracks arising in the workpiece 5 serve as rupture initiation points and the workpiece 5 breaks. As illustrated in Figure 36, on the cut end face of the workpiece 5, although the coating layer 5b remains in the cutting depression part, almost none of the coating layer 5b remains on the workpiece surface. cut and the metallic material 5a is exposed on the fracture surface. In this regard, on the cut end face of the workpiece 5, the corrosion resistance of the cutting surface and the fracture surface in which the metal material 5a is almost completely exposed is low and there is a concern of red rust may occur. For example, sacrificial protection by a metal coating layer or chemical treatment is commonly used as measures to prevent oxidation on the cut end face of a metal coating layer of metal on which a metal coating layer is formed. on the surface of a metallic material. For example, Patent Document 1 describes that a cutting process is performed such that, within a range of 0.10 times or more of the sheet thickness in the sheet thickness direction, the size of a shear depression of one cut end face falls within a range of 0.45 times or more of the sheet thickness in the flat surface direction. A tensile force and a cutting force applied to the metal material are increased by such a cutting process, a metal layer coated with metallic coating on the surface of the base metal material is made to go around the end face cut and at least a portion of the cut surface of the cut end face is covered with the metal coating layer. The appearance of red rust on the cut end face is suppressed by a sacrificial protective action of the metal coating layer extending to the cut end face. Furthermore, Patent Document 2 describes a method in which a surface-treated steel sheet is cut with a rotating blade that moves up and down and subsequently the end face is subjected to processing using a roller. deformation. Furthermore, Patent Document 3 describes a laminated substrate cutting method in which a laminated substrate is transferred and placed in a pressing tool composed of a top blade mold having a top blade with a front end cross section V-shaped and a lower blade mold having a lower blade having the same structure shape as the upper blade and facing the upper blade mold and being cut by the upper blade and the lower blade when the upper knife mold or the upper knife and the lower knife mold perform a moving operation. Furthermore, Patent Document 4 describes a method of manufacturing an electrical contact in which an outer shell composed of a material having favorable weldability is adhered to a wire rod to form a linear contact material and that cuts the contact material. contact through MA / I / UOO I ¿or of the outer cover with a cutter having a cutting edge having a wedge-shaped cross section whose upper surface is inclined, the outer cover is plastically deformed and a coating of the material is formed that has favorable weldability on the cutting surface of the wire rod and the wire rod is bonded to the contact base metal through the cutting surface. A recess is provided partly along the slope of the upper surface of the cutting edge. LIST OF STATE OF THE ART DOCUMENTS PATENT DOCUMENTS Patent Document 1: JP2017-87294A Patent Document 2: JP2018-075600A Patent Document 3: JP2006-315123A Patent Document 4: JPH1-255117A Patent Document 5: WO 2016 / 027288 Patent Document 6: JP2012-101258A Patent Document 7: JP2008-155219A NON-PATENT DOCUMENT Non-Patent Document 1: Osamu KADA and two others, Advanced Forming Analysis for Bar and Wire Rod with Finite Element Method, Nippon Steel Technical Report , Nippon Steel Corporation, March 2007, No. 386, p. 59-63. SUMMARY OF THE INVENTION TECHNICAL PROBLEM However, in the patent document 1, mentioned above, the metal coated metal layer on the surface of the base metal material only covers at least a part of the cut surface of the cut end face and the metal material. base remains exposed on the fracture surface. Consequently, the corrosion resistance of the cut end face of the metal coated metal sheet is not sufficient. Furthermore, in general, when an attempt is made to impart excessive sacrificial protection property to the cut end face for the purpose of preventing oxidation, the metal coating on the surface of the metal coated metal sheet decreases and the resistance to corrosion Surface corrosion on the surface of the metal-coated metal sheet (that is, the corrosion resistance of the flat surface) decreases. MA / I / UOO I Furthermore, in patent document 2, mentioned above, the coverage of the metal coating is increased by performing two processes, that is, a process for cutting a steel sheet with surface treatment and a process for forming a portion of the face of the end of the steel sheet with surface treatment that was cut. However, because a plurality of processes need to be performed, the cost of the equipment increases. Furthermore, in the technique described in Patent Document 2, after cutting the surface-treated steel sheet with a rotating blade moving up and down, the shape of the end face portion is adjusted and, Consequently, because the stress is imparted in different directions, in the respective processes, cracks or detachments are likely to occur in the metal coating layer. Furthermore, in the technique described in Patent Document 2, it is necessary to flow a larger amount of the metal coating layer from the surface side to cover the end face of the steel sheet which is the base material. Consequently, there is a possibility that a defect such as cracking of the metal coating on the outer layer or localized thinning of the metal coating may occur or that the metal coating may flow onto the surface of the steel sheet that has been a coating of rust or contamination adhered resulting in poor adhesion of the metallic coating. Furthermore, in the aforementioned patent document 3, the leading end of the cutting edge has a flat portion as illustrated in Figure 2(a). Therefore, when a laminate substrate is cut using such a tool, the metal coating splits when the blade bites into the laminate substrate and the cut end face is not covered by the metal coating. Furthermore, because the state at the end of cutting is one in which the material is crushed, it is difficult to cut the laminated substrate in a single process, or to impart sufficient damage to the laminated substrate in a first process and perform the cutting to make the End face cut into desired shape in next process. Furthermore, in the aforementioned patent document 4, the objective is to make the metal coating of the wire rod cover the end face thereof during cutting. As illustrated in Figure 1 and Figure 2 of Patent Document 4, although one side of the cutter blade in question is an inclined face, the other side is a substantially vertical face and therefore the shape has an asymmetry remarkably high. When the blade bites into the wire rod, the blade and the wire rod come into contact at one point, and consequently almost no force is generated in the direction perpendicular to the direction in which the blade is advancing. Therefore, when the workpiece is a wire rod, it is possible to cut the workpiece even in the case of the cutting edge shape illustrated in patent document 4. On the other hand, in the case of cutting a workpiece which is a tabular material, the blade and the workpiece come into contact with each other in the form of a line. Therefore, in the case of the shape of the cutting edge shown in patent document 4, a large ΜΛ / I / UOO I ¿or force in the direction perpendicular to the direction in which the blade advances and increases the load on the blade. Although in a case where the workpiece is extremely soft with respect to the blade, as in the case of a resin piece, the load that arises on the sheet in question is not a problem, in the case of cutting a material that has a certain resistance or more, such as a metallic material, it causes the durability of the blade to deteriorate noticeably. Therefore, the present invention has been made in view of the problems described above and an object of the present invention is to provide a novel and improved cutting method and cutting tool which, with respect to cutting a workpiece, are capable of suppressing the occurrence of a situation in which the performance of the workpiece is reduced after cutting. SOLUTION TO THE PROBLEM According to one embodiment of the present invention, a cutting method is provided for cutting a workpiece using a cutting tool comprising a die and a punch, including arranging the workpiece between the die and the punch and in a state in which a first wedge-shaped cutting part of the die and a second wedge-shaped cutting part of the punch are opposite, pushing the punch relatively to the side of the die to cut the workpiece; where: a leading end angle θι of the first cutting part and a leading end angle O2 of the second cutting part are each 10° or more and 120° or less and a leading end radius Ri of the first cutting part and a radius of the front end radius R2 of the second cutting part are each 0.5% or more and 35.0% or less of a thickness of the sheet. The workpiece may be a multilayer material formed by coating a surface of a base material with a coating material. The front end angle θι of the first cutting part and the front end angle θ2 of the second cutting part may each be 30° or more and 90° or less. The front end radius Ri of the first cutting part and the front end radius R2 of the second cutting part may each be 1.5% or more and 10.0% or less of the thickness of the sheet. Cutting of the workpiece can be performed by a plurality of cutting processes. The plurality of cutting processes may include a first cutting process and a second cutting process that is performed after the first cutting process and, in the second cutting process, at least one of the following may be performed: an angle of the front end θι of the first cutting part in the second cutting process becomes smaller than a front end angle θι of the ΜΛ / I / UOO I ¿o first cutting part in the first cutting process and a front end angle 02 of the second cutting part in the second cutting process becomes smaller than a front end angle 02 of the second part of cutting in the first cutting process and subsequently the workpiece can be cut. Furthermore, the plurality of cutting processes may include a first cutting process and a second cutting process that is performed after the first cutting process and, in the second cutting process, at least one of the following may be performed: a front end radius Ri of the first cutting part in the second cutting process becomes smaller than a front end radius Ri of the first cutting part in the first cutting process and a front end radius R2 of the second part The cutting part in the second cutting process is made smaller than a front end radius R2 of the second cutting part in the first cutting process, and subsequently the workpiece can be cut. In addition, among the plurality of cutting processes, when the radius of the front end of the first cutting part is defined as Rj, the radius of the front end of the second cutting part is defined as R2, and the sheet thickness of the workpiece work is defined as t, a stroke S of the punch in a first cutting process can satisfy the expression (A) below: (Ri+R2)<S<{t- (Ri+R2)} ... (A ). A workpiece trimming width is a distance between an end portion of the workpiece and a cutting position of the workpiece, and when a radius of the front end of the first cutting part is defined as Rj, a leading end radius of the second cutting part is defined as R2 and the thickness of the workpiece sheet is defined as t, a cutting width D of the workpiece can satisfy expression (B) below: R<D<3t ... (B) R = Min(Ri, R2). A first wedge-shaped cutting part of the die and a second wedge-shaped cutting part of the punch may have an asymmetrical shape with respect to a normal line at a cutting edge, respectively. Here, a leading end angle θι of the first cutting part is divided into two angles 0ia and Oib by a normal line on a cutting edge of the first cutting part, a leading end angle 02 of the second cutting part is divided. at two angles 02a and 02b by a normal line on a cutting edge of the second cutting part and (0ia-0ib) or (0ib-0ia), which is an angular difference between angle 0ia and angle 0ib and (02a-02b) or (02b-02a), which is an angular difference between angle 02a and angle 02b, can be 5oo more and 45° or less. Furthermore, when a leading end radius Ri of the first cutting part is taken as an average value of the respective leading end radii Ri and Rib of the first cutting part MA / I / UOO I ¿ó cut formed when the leading end radius Ri is bisected by a normal line at a cutting edge of the first cutting part and a leading end radius R2 of the second cutting part is takes as an average value of the respective leading end radii R2a and R2b of the second cutting part which are formed when the leading end radius R2 is bisected by a normal line at a cutting edge of the second cutting part, the Front end radii R, and R2 may be 0.5% or more and 35.0% or less of the sheet thickness, respectively. A Ria / Rib or Rib / Ria relationship between two leading end radii formed when the leading end radius Ri of the first cut part is divided into two and a R2a / R2b or R2b / R2a relationship between two leading end radii formed when the front end radius R2 of the second cutting part is divided into two, each may be 1.1 or more and 100 or less. Further, the forming may include, from the workpiece, an intermediate material having a final shape region and a surplus region provided along an edge of the final shape region and using a cutting tool including a die and a punch in each of which a cutting part is formed into a closed shape, in correspondence with the edge of the final shape region, in a state in which a first wedge-shaped cutting part of the The die and a second wedge-shaped cutting part of the punch are opposed, urging the punch relatively to the side of the die to cut the intermediate material. In accordance with another embodiment of the present invention, there is provided a cut article formed by cutting a workpiece, including a cut end face of the cut article comprising: a first sloping face sloping from a first surface toward a center at a direction of the thickness of the sheet, a second sloped face which slopes from a second surface towards the center in the direction of the thickness of the sheet, and a fracture surface which is formed between the first sloped face and the second sloped face and at where the thickness of a sloped face when the cut end face is viewed from the front satisfies the relational expression (C) below: (Tt+T2)<T ... (C) Ti = AicosQi, T2= A2cos02where T । represents a thickness of the first inclined face when the cut end face is viewed from the front, T2 represents a thickness of the second inclined face when the cut end face is viewed from the front, Ai represents a length of the first inclined face when the cut end face is observed from the side, A2 represents a length of the second inclined face when the cut end face is observed from the side, 0i represents an angle of inclination of the first inclined face, 02 represents an angle of inclination of the second inclined face and T represents a thickness of the workpiece sheet. MA / I / UOO I A thickness T3 of the fracture surface when the cut end face is viewed from the front can satisfy the relational expression (D) below: <T3<0.5T... (D). The workpiece may be a multi-layer material formed by coating a surface of a base material with a coating material and at least a portion of the first inclined face and the second inclined face may be coated with the coating material covering the surface of the base material. At least a portion of the first inclined face may be coated with a coating material that covers the first surface of the base material and at least a portion of the second inclined face may be coated with a coating material that covers the second surface of the base material. A sheet thickness t of the base material may be 0.2 mm or more and 10 mm or less. ADVANTAGEOUS EFFECTS OF THE INVENTION As described above, according to the present invention, when a workpiece is cut, the occurrence of a situation in which the performance of the workpiece is reduced after cutting can be suppressed. For example, when cutting a workpiece that has undergone surface treatment, while maintaining the function of a coating material on a flat surface of the base material, the function of the coating material can also be made to perform on a cut end face. BRIEF DESCRIPTION OF THE FIGURES Figure 1 is an explanatory drawing illustrating a cutting tool according to a first embodiment of the present invention and illustrating a state before cutting a workpiece. Figure 2 is an explanatory drawing illustrating a state after cutting the workpiece by means of the cutting tool illustrated in Figure 1. Figure 3 is an explanatory drawing illustrating another configuration of a cutting tool according to the first embodiment. Figure 4 is an explanatory drawing schematically illustrating a cut end face of a workpiece that was cut by the cutting tool according to the first embodiment. Figure 5 is an image of a face of the cut end of a workpiece when the workpiece has been cut by the cutting tool according to the first embodiment. ΜΛ / t / ZUZ I / UOO I Zó Figure 6 is an explanatory drawing illustrating the cutting tool according to the first embodiment and illustrating a deviation amount between the position of the front end of a first cutting part and the position of the front end of a second cutting part. Figure 7 is a schematic diagram for describing a trimming width of a workpiece. Figure 8 is a graph illustrating an example of the relationship between trim widths and fracture surface ratios. Figure 9 shows front photographs of the cut end faces of the respective workpiece pieces, which were cut using the respective trim widths set forth in the example illustrated in Figure 8. Figure 10 is a schematic diagram illustrating an example in which, with respect to a cutting part of a punch, the left and right angles of the cutting part bisected by a normal line are made different from each other to make that the cutting part has an asymmetrical shape. Figure 11 is a schematic diagram illustrating an example in which, with respect to a cutting part of a punch, the right and left front end radii of the cutting part divided in two by a normal line are They are made different from each other to make the cutting part have an asymmetrical shape. Figure 12 is an explanatory drawing illustrating the cutting tool according to the first embodiment and illustrating a deviation amount between the position of the front end of the first cutting part and the position of the front end of the second cutting part. Figure 13 is a plan view illustrating cutting positions of a workpiece according to a second embodiment of the present invention. Figure 14 is an explanatory drawing illustrating a process for forming an intermediate material in a cutting method according to the second embodiment. Figure 15 is an explanatory drawing illustrating a cutting process in the cutting method according to the second embodiment. Figure 16 is an explanatory drawing illustrating a cutting tool used in the cutting process according to the second embodiment and illustrating a state before cutting a workpiece. Figure 17 is an explanatory drawing illustrating a state after cutting the workpiece by means of the cutting tool illustrated in Figure 16. Figure 18 is an explanatory drawing illustrating the cutting tool according to the second embodiment and illustrating a deviation amount between the position of the front end of a first cutting part and the position of the front end of a second cutting part. M A / I / UOO I Figure 19 is a plan view illustrating the cutting positions of a workpiece in another cutting method according to the second embodiment. Figure 20 is an explanatory drawing illustrating a process for forming an intermediate material in the other cutting method according to the second embodiment. Figure 21 is an explanatory drawing illustrating a cutting process in the other cutting method according to the second embodiment. Figure 22 is an explanatory drawing schematically illustrating a cut end face of a cut article according to an embodiment of the present invention. Figure 23 is an explanatory drawing to describe the shape of the article cut according to the embodiment illustrated in Figure 22. Figure 24 is an explanatory drawing illustrating another example of the shape of the article cut according to the embodiment illustrated in Figure 22. Figure 25 shows, as an example (A), front photographs and lateral cross-sectional photographs of the cut end faces of metal-coated metal materials that were cut with a cutting tool. Figure 26 is a graph illustrating, by way of example, the sheet thickness ratios representing a state of coverage of a metallic material by metallic coating, with respect to the cut end face of a metallic material with metallic coating . Figure 27 is an explanatory drawing illustrating, with respect to the photographs shown in Figure 25, a sheet thickness and a metal coating layer thickness of the metal coated metal materials when the thickness ratios of the metal coating were calculated. sheet in figure 26. Figure 28 shows, as an example (E), front photographs and photographs of a side cross section of the cut end faces of metallic coated metal materials that were cut with a cutting tool. Figure 29 shows, as an example (F), front photographs and photographs of a side cross section of the cut end faces of metallic coated metal materials that were cut with a cutting tool. Figure 30 is an explanatory drawing schematically illustrating, as in example (G), the cut end faces of the workpieces when the shape of the cutting edge of the cutting tool was changed. Figure 31 is a schematic diagram which, as in example (H), represents cutting edge shapes related to the presence or absence of a flat portion at a leading end of a cutting edge. MA / I / UOO I Figure 32 is a view illustrating the results of the analysis and whether or not a metallic material with metallic coating can be cut in example (I). Figure 33 is a plan view illustrating the shape of a test specimen used in a fatigue test. Figure 34 is a graph showing the results of the fatigue test. Figure 35 is an explanatory drawing illustrating an example of a conventional cutting tool. Figure 36 is an explanatory drawing schematically illustrating a cut end face of a workpiece that was cut using the cutting tool illustrated in Figure 35. DESCRIPTION OF THE MODALITIES Preferred embodiments of the present invention are described in detail below, with reference to the attached figures. It is worth mentioning that, in the present description and the accompanying figures, constituent elements having substantially the same functional configuration are indicated with the same reference characters and a duplicate description thereof is omitted. 1. First modality 1-1. Schematic configuration of cutting tool 1. Schematic configuration First of all, based on Figure 1 to Figure 3, the schematic configuration of a cutting tool 100 will be described, according to a first embodiment of the present invention. It is noted that Figure 1 is an explanatory drawing illustrating an example of the cutting tool 100, according to the present embodiment, and illustrating a state before cutting a workpiece 5. Figure 2 is an explanatory drawing illustrating a state after cutting the workpiece 5 by means of the cutting tool 100 illustrated in Figure 1. Figure 3 is an explanatory drawing illustrating another configuration of the cutting tool 100, according to the present embodiment. An example is illustrated from Figure 1 to Figure 3 in which when the sheet length direction of the workpiece 5 is taken as the X direction, the sheet width direction is taken as the Y direction. and the sheet thickness direction is taken as the Z direction, the workpiece 5 is cut along the sheet width direction. The cutting tool 100, according to the present embodiment, is a tool that cuts a workpiece that has been subjected to a surface treatment. In the following description, a surface treated material having a coating layer (a coating layer 5b in ΜΛ / I / UOO I ¿or Figure 4) on the surface of a metal material (a metal material 5a in Figure 4) which is a base material is adopted as an example of a workpiece. Examples of this type of workpiece include a metal coated metal sheet obtained by subjecting the surface of a metal sheet to a metal coating treatment, a painted metal sheet obtained by coating the surface of a metal material as a base material with paint and a laminated film of metal sheet obtained by laminating a film on a metal sheet. As illustrated in Figure 1, viewed from the direction of the width of the sheet (Y direction), the cutting tool 100, according to the present embodiment, is composed of a die 110 having a first cutting part 113 in wedge-shaped on a base 111 and a punch 120 having a second wedge-shaped cutting part 123 on a base 121. The first cutting part 113 and the second wedge-shaped cutting part 123 extend in the direction of the width of the sheet (Y direction) and the workpiece 5 is cut along the extension direction of the first cutting part 113 and the second cutting part 123. The workpiece 5 to be cut by the first cutting part 113 of the die 110 and the second cutting part 123 of the punch 120 is arranged between the die 110 and the punch 120. For example, the workpiece 5 is placed on the die 110. At this time, the die 110 and the punch 120 are installed so that the first cutting part 113 and the second cutting part 123 face each other. Then, in a state that the workpiece 5 has been set on the die 110, the punch 120 is pushed down relative to the die 110, so that the workpiece 5 is cut as illustrated in the figure. 2. At that time, the use of a blank support to hold the workpiece 5 is not necessarily required. However, for example, as illustrated in figure 3, if a blank support is used blank 130, the workpiece 5 can be supported by the pads 131, 132, 133 and 134 on both sides of the cutting portions 113 and 123. In this case, the inclination of the workpiece 5 is suppressed and Cutting can be done stably. It should be mentioned that it is sufficient that the blank holder 130 is provided on at least one of the die 110 and the punch 120. That is, in the example illustrated in Fig. 3, when the blank holder 130 is provided on die 110 only, only pads 133 and 134 need to be provided and when the blank holder 130 is provided on punch 120 only, only pads 131 and 132 need to be provided. The cutting tool 100, according to the present embodiment, is configured so that, when the punch 120 is pushed towards the die 110, by means of the tensile forces that arise between the first cutting part 113 and the second part 123 and the workpiece 5, a coating layer on the respective surfaces of the workpiece 5 is caused to spread over the cut end face so that the cut end face is covered with the coating layer . MA / I / UOO I That is, the coating layer on the respective surfaces of the workpiece 5 is made to follow the movements of the first cutting part 113 and the second cutting part 123 with respect to the workpiece 5 when the punch 120 is pushed toward the die 110 and the coating layer is caused to extend over the cut end face. In this way, the cut end face of the workpiece 5 is coated with the coating layer. 2. Coating the cut end face with a coating layer An example of the cut end face of the workpiece 5 that was cut by the cutting tool 100 is illustrated in Figure 4. In Figure 4, a cross section of a side face (i.e., a face viewed from sheet width direction) of the cut end face of the workpiece 5 is illustrated schematically. As illustrated in Figure 4, the cut end face of the workpiece 5 is composed of cutting depressions s 1 and s2, inclined faces s3 and s4 and a fracture surface s5. The cutting depression si and the inclined face s3 are formed by the first cutting part 113 of the die 110. The cutting depression s2 and the inclined face s4 are formed by the second cutting part 123 of the punch 120. The fracture surface s5 is formed as a result of breaking the workpiece 5 in a manner in which the cracks generated in the workpiece 5 by the first cutting part 113 and the second cutting part 123 serve as starting points. As illustrated in Figure 4, the coating layer 5b on the upper surface side of the metal material 5a covers the metal material 5a continuously from the surface of the metal material 5a to the cutting depression si and the inclined face s3. Similarly, the coating layer 5b on the bottom surface side of the metal material 5a covers the metal material 5a continuously from the surface of the metal material 5a to the cutting depression s2 and the inclined face s4. Thus, in the workpiece 5 that was cut by the cutting tool 100, according to the present embodiment, the region from each surface of the metallic material 5a to the cut end face is covered with the same continuous coating layer 5b . Figure 5 shows an image of the cut end face of the workpiece 5 when the workpiece 5 has been cut by the cutting tool 100, according to the present embodiment. As illustrated in Figure 5, it was found that, on the inclined faces of the workpiece, the surface of the metal material is coated with the coating layer. For example, after the workpiece 5 has been cut, it is possible to cover the cut end face by subjecting the cut end face to a surface treatment such as metal coating or painting. However, it is difficult to cover the cut end face with a material having the same composition as the coating layer 5b of the workpiece 5 and the corrosion resistance of the cut end face will be low compared to the surface. of metallic material 5a. On the contrary, because the workpiece 5 that was cut by the cutting tool 100, according to MA / I / UOO I or the present embodiment, it is covered from each surface to the cut end face of the metallic material 5a with the same continuous coating layer 5b simultaneously with the cutting, it is difficult for the cut end face to rust . Therefore, by cutting the workpiece 5 using the cutting tool 100, according to the present embodiment, the workpiece 5 having a high corrosion resistance on the cut end face can be provided. It is worth mentioning that the shape of the cut end face of the workpiece 5 that was cut by the cutting tool 100, according to the present embodiment, depends on the shape of the first cutting part 113 and the second part cutting part 123. Because the first cutting part 113 and the second cutting part 123 each have a wedge shape, the shape on the cut end face of the workpiece 5 is a shape having the faces inclined s3 and s4 along the wedge-shaped inclinations, as illustrated in Figure 4, and not a vertical shear surface, as illustrated in Figure 36. Therefore, for example, the cut end face of the workpiece 5 that was cut by the cutting tool 100 illustrated in Figure 1 has a shape that protrudes progressively in the direction towards the center in the direction of the thickness of the sheet. By making the shape of the first cutting part 113 and the second cutting part 123 wedge-shaped, when cutting the workpiece 5 it is easy for the coating layer 5b on the surfaces of the metal material 5a to follow the movements of the first cutting part 113 and the second cutting part 123 along the inclinations of the wedge shape. As a result, as illustrated in Figure 4, the coating layer 5b on the surfaces of the metal material 5a can be made to follow the movements of the first cutting part 113 and the second cutting part 123 to the inclined faces s3 and s4 of the cut end face and not only the cutting depressions si and s2. Furthermore, because the cutting depressions s 1 and s2 are formed on both the front and rear surfaces of the workpiece 5 by the cutting part 113 and the cutting part 123, a cutting surface without burrs is formed. Furthermore, the coating layer 5b on the surfaces of the metal material 5a follows the inclinations of the first cutting part 113 and the second cutting part 123 to move to the cut end face. At this time, the amount of the coating layer 5b covering the surfaces of the inclined faces s3 and s4 of the cut end face gradually decreases towards the fracture surface s5, as illustrated in Figure 4. By making the coating layer 5b covers the surface of the inclined faces s3 and s4 in this way, even if the area of ​​the cut end face of the metal material 5a that is coated with the coating layer 5b increases, the amount of the coating layer 5b covering the surface of the metal material 5a moving towards the cut end face hardly increases, and therefore the corrosion resistance of the flat surface of the workpiece 5 can be maintained. ΜΛ / I / UOO I O It is worth mentioning that because the fracture surface s5 is a surface that is formed as a result of cracks that cause the workpiece 5 to break, it is difficult to make the coating layer 5b extend to the fracture surface s5. However, because the workpiece 5 is cut along the inclined surfaces of the first cutting part 113 and the second cutting part 123 until it enters a state in which a front end 113a of the first cutting part 113 and a front end 123a of the second cutting part 123 substantially contact each other, the proportion of the cut end face representing the fracture surface s5 is very small. Therefore, even if the fracture surface s5 is not covered with the coating layer 5b, the corrosion resistance is not significantly reduced. Furthermore, by making the first cutting part 113 of the die 110 and the second cutting part 123 of the punch 120 wedge-shaped as in the cutting tool 100, according to the present embodiment, it is also possible to cut, for example , a material having a tensile strength of 200 MPa or more or a thick material. Furthermore, it is possible to cut a material having a tensile strength of 270 MPa or more and, furthermore, a material having a tensile strength of 590 MPa or more. 1-2. Shape of cutting part to. Case where the shape of the cutting part is symmetrical In the cutting tool 100, according to the present embodiment, the first cutting part 113 of the die 110 and the second cutting part 123 of the punch 120 have the same wedge shape as illustrated in Figure 1. However, it is sufficient that each of the first cutting part 113 and the second cutting part 123 has at least a wedge shape and, preferably, the shape of each of the first cutting part 113 and the second cutting part 123 satisfies the following conditions with respect to the shape. Front end angle A front end angle θι of the first cutting part 113 and a front end angle 02 of the second cutting part 123 are preferably formed of 10° or more and 120° or less. When the angles of the front ends 01 and 02 are 10° or more, the inclination is large, and therefore the ability of the coating layer 5b to follow the movement of the cutting parts is improved and the corrosion resistance of the cut end face is further improved. Furthermore, the stress applied to the cutting part 113 and the cutting part 123 is decreased, damage to the cutting edges is suppressed, and the durability of the tool is improved. Furthermore, when the angles of the front ends 01 and 02 are 120° or less, the load required to cut the workpiece 5 does not become too large and cracks are easily generated in the workpiece 5 when the respective cutting edges are pushed inwards and thus cutting the workpiece 5 is facilitated. Therefore, the angle of the front end ΜΛ / I / UOO I ¿or Θ i of the first cutting part 113 and the angle of the front end 02 of the second cutting part 123 are made 10° or more and 120° or less and, more preferably, are made 30° or more and 90° or less. Front End Radius A front end radius Ri of the first cutting part 113 and a front end radius R2 of the second cutting part 123 are preferably formed to be 0.5% or more and 35.0% or less of the value of a thickness of the sheet t. When the front end radii Ri and R2 are each 0.5% or more of the sheet thickness value t, the stress applied to the cutting edges of the cutting part 113 and the cutting part 123 does not become too large, damage to cutting edges is suppressed and durability is improved. Furthermore, when the front end radii Ri and R2 are each 35.0% or less of the sheet thickness value t, the shape of the cut end face is good. Furthermore, since cracks are easily generated in the workpiece 5 when the respective cutting edges are pushed inward, the cutting of the workpiece 5 is further facilitated. Therefore, the front end radius Ri of the first cutting part 113 and the front end radius R2 of the second cutting part 123 are made 0.5% or more and 35.0% or less of the value of the sheet thickness t and, more preferably, are made 3.0% or more and 10.0% or less than the value of the thickness of the sheet t. In this case, the first cutting part 113 and the second cutting part 123 may have different shapes from each other. For example, if at least one of the front end radii Ri and R2 and the front end angles θι and 02 is different, the first cutting part 113 and the second cutting part 123 will have different shapes from each other. By making the first cutting part 113 and the second cutting part 123 have a different shape from each other, the relationship of the fracture surface can be changed. It is worth mentioning that the fracture surface ratio is the ratio between the fracture surface s5 and the thickness of the workpiece sheet 5. At that time, the relationship between the front end radius Ri of the first cutting part 113 and the front end radius R2 of the second cutting part 123 (ratio of the front end radii R1 / R2 or R2 / Ri) is preferably less than 100 and, more preferably, is less than 10. Most preferable is a case where the front end radii Ri and R2 are equal. It should be mentioned that, the magnitude relationship between the front end radius Ri of the first cutting part 113 and the front end radius R2 of the second cutting part 123 is not particularly limited. Furthermore, the relationship between the front end angle θι of the first cutting part 113 and the front end angle 02 of the second cutting part 123 (ratio of the front end angles Θ i / 02 or 02 / 01) is preferably less than 4 and, more preferably, less than 2. Most preferable is a case where the front end angles θι and 02 are equal. It is noted that the magnitude relationship between the front end angle θι of the first cutting part 113 and the front end angle 02 of the second cutting part 123 is not particularly limited. MA / I / UOO I By setting the front end radius ratio R1 / R2 or R2 / R1 and the front end angle ratio Θ1 / Θ2 or θ2 / θι within the above ranges, the surface area ratio can be reduced. fracture. When at least one of the front end radii and the front end angles differ significantly between the first cutting part 113 and the second cutting part 123, cutting will be carried out first by one of the cutting parts and, by Therefore, the deformation of the workpiece 5 will be concentrated. As a result, the breakage of the workpiece 5 will occur earlier and the failure surface ratio will increase and consequently the end face ratio will decrease. cut which is coated with the coating layer 5b. Therefore, by setting the front end radius ratio R1 / R2 or R2 / R1 and the front end angle ratio Θ1 / Θ2 or 62 / 61 to be within the above-mentioned ranges, the the fracture surface can be reduced. Amount of deviation between front end positions The position of the front end 113a of the first cutting part 113 and the position of the front end 123a of the second cutting part 123 can be made to coincide in a horizontal direction perpendicular to the direction in which the die 110 and the punch 120 are facing each other (i.e., the direction of the sheet thickness of the workpiece 5), as illustrated in Figure 1 and Figure 2. By causing the position of the front end 113a of the first part cutting part 113 and the position of the front end 123a of the second cutting part 123 match, a force in the X direction applied to the cutting part 113 and the cutting part 123 can be reduced, thereby improving durability. Furthermore, cracks may be generated from the cutting edge at a suitable time to complete the cut. Alternatively, as illustrated in Figure 6, the position of the front end 113a of the first cutting part 113 and the position of the front end 123a of the second cutting part 123 may deviate from each other by a deviation amount x in the direction horizontal. The phrase “deflection amount the X direction) which is perpendicular to the direction in which the first cutting part 113 and the second cutting part 123 face each other. The amount of deviation between the front end positions is preferably 50% or less of the sheet thickness value t. If the amount of deviation between the leading end positions is 50% or less of the sheet thickness value t, the workpiece 5 can be cut in such a way that the desired properties of the face of the workpiece are reliably obtained. extreme. Trim Width The phrase “trimming width D of workpiece 5” refers to the length of workpiece 5 that must be left from the cutting position in the direction of the length of the sheet (direction MA / I / UOO I X) When cutting with the cutting tool 100. For example, as illustrated in Figure 7, the cutting width D of the workpiece 5 is represented by the length from the cutting position to one of the extreme portions of the workpiece 5. As illustrated in Figure 6, in a case where the position of the front end 113a of the first cutting part 113 and the position of the front end 123a of the second cutting part 123 deviate from each other , it is enough to take the cutting width D of the workpiece 5 as, for example, the length of an end portion of the workpiece 5 at the position of the front end of the cutting part on the side closest to the portion of relevant extreme. It is seen that, in Figure 7, a pad 140 is arranged between the die 110 and the workpiece 5 on the side opposite to the side on which the cutout width D of the workpiece 5 is taken. The pad 140 It functions similarly to the pads 131, 132, 133 and 134 of the blank holder 130 illustrated in Figure 3. The cutting width D of the workpiece 5 is equal to or greater than the front end radius R of the cutting part and is 5 times or less than the sheet thickness t of the workpiece 5 (R<D< 5t) and, in particular, it is preferably 3 times or less the thickness of the sheet t of the workpiece 5 (R<D<3t). More preferably, the cutout width D of the workpiece 5 is 3 times or more of the front end radius R of the cutting part and is equal to or less than the sheet thickness t of the workpiece 5 (3R <D<t). It is worth mentioning that the phrase “front end radius R of the cutting part” refers to the front end radius Ri of the first cutting part 113 or the front end radius R? of the second cutting part 123. In a case where the front end the radii Ri and R? are equal, R = Ri = R2. In a case where the front end radius Ri and R2 are different from each other, the smallest radius between the front end radius Ri of the first cutting part 113 and the front end radius R2 is taken from the second cutting part 123 as the front end radius R (R = Min(Ri, R2)). By setting the cutout width D to be 5 times or less the thickness of the sheet t and, more preferably, 3 times or less the thickness of the sheet t, the formation of the fracture surface s5 due to cutting and the fracture surface ratio can be reduced. Figure 8 shows an example of the relationship between the cutout width D and the fracture surface ratio. Figure 8 shows the fracture surface ratios when the workpiece 5, whose sheet thickness t was 3.2 mm, was cut by the cutting tool 100 illustrated in Figure 1, in cases where the cutting width D was set to 1.6mm (=0.5t), 3.2mm (=t), 5.0mm (~1.6t), 6.4mm (=2.0t), 10.0mm (~3.1t), 12.8mm (=4.0t) and 16.0 mm (= 5.0t), respectively. In these cases, a galvanized steel sheet with a sheet thickness of 3.2 mm and a tensile strength of 460 MPa was used as the workpiece 5. The front end radius R of the cutting tool 100 was set to 0.05 mm and the front end angle Θ of it was set at 60°. Two graphs with the same width MA / I / UOO I or cutout D show the fracture surface ratios measured for the two pieces of the workpiece 5 that was cut by the cutting tool 100. Furthermore, in Figure 9, the cut end faces of the respective pieces of workpieces 5 that were cut at the cutout widths D of 1.6 mm, 3.2 mm, 6.4 mm and 12.8 mm are shown as examples of faces. of the cut ends. Based on Figure 8 and Figure 9, it was found that the smaller the cutout width D, the more the fracture surface ratio decreased. Furthermore, it was found that when the trim width D is equal to or less than the sheet thickness t, the fracture surface ratio decreases further. On the other hand, by setting the trimming width D to be equal to or larger than the front end radius R of the cutting part, and in particular to be 3 times or more of the front end radius R, the offset can be suppressed. of the cutting edge due to elastic deformation of the tool during cutting and a good end face shape can be obtained by cutting. By changing the shape of the first cutting part 113 of the die 110, the shape of the second cutting part 123 of the punch 120, the amount of deviation between the positions of the leading ends of the respective cutting parts 113 and 123 or the trim width D of workpiece 5 thus changes the shape of the cut end face of workpiece 5 cut by cutting tool 100 and changes the cover state of the cut end face by the layer coating 5b. Therefore, it is enough to properly set the shape of the first cutting part 113 of the die 110 and the shape of the second cutting part 123 of the punch 120, the amount of deviation between the positions of the leading ends of the respective parts of cut 113 and 123 and the cut width D of the workpiece 5, according to the shape of the cut end face or the corrosion resistance that is required for the workpiece 5 after cutting. Height of cutting parts It is enough to set a height hi of the first cut part 113 and a height h2 of the second cut part 123 so that at least the sum of these heights (hi+hg) is greater than the thickness of the sheet t of the piece. work 5. The shape of the cutting tool 100, according to the present embodiment, and a state of coverage with respect to the coverage by a coating layer of a face of the cut end of the workpiece 5 that was cut using the cutting tool cut 100 have been described above. The cutting tool 100, according to the present embodiment, is composed of the die 110 and the punch 120 having the wedge-shaped cutting portions 113 and 123, respectively. By cutting the workpiece 5 with the wedge-shaped cutting parts 113 and 123, the coating layer 5b on each surface of the metal material 5a can be made to follow the movement of the cutting parts 113 and 123 and spread out. on the cut end face. Each of the inclined faces s3 and s4 of the cut end face M A / I / UOO I ¿ó is coated with the coating layer 5b continuously from the respective surfaces of the metallic material 5a, so that the amount of coating layer covering the cut end face decreases towards the fracture surface s5. Therefore, the corrosion resistance of the cut end face can be improved while maintaining the corrosion resistance of the flat surface of the workpiece 5. It is noted that cutting the workpiece 5 with the cutting tool 100 can be carried out by performing a single cutting process or by cutting by performing a plurality of cutting processes. The phrase "cutting performed by carrying out a plurality of cutting processes" refers to executing a cutting process in which the die 110 is pushed downward relative to the punch 120 a plurality of times to thereby cut the workpiece 5. in two pieces. Various types of cut end faces can be made when cutting the workpiece 5, performing a plurality of cutting processes. For example, when the workpiece 5 is cut by performing a plurality of cutting processes, the front end angle θι of the first cutting part 113 and the front end angle 02 of the second cutting part 123 can become smaller in a stepwise manner in the respective cutting processes. As a more specific description, it will be assumed that the plurality of cutting processes includes a first cutting process and a second cutting process that is performed after the first cutting process. At that time, in the second cutting process, at least one operation among an operation that makes the front end angle θι of the first cutting part 113 smaller than the front end angle θι in the first cutting process and an operation that makes the front end angle 02 of the second cutting part 123 smaller than the front end angle 02 in the first cutting process, and subsequently cutting the workpiece 5. Thus, The portion of the cut end face that is coated with the coating layer 5b can be increased and a good shape of the end face can be obtained. At this time, it is good to make a stroke S of the punch 120 gradually smaller in each cutting process. By adjusting the stroke by a large amount in the initial cutting process, the ability of the coating layer 5b to follow the movements of the first cutting part 113 and the second cutting part 123 is increased. For example, among the plurality of cutting processes, the stroke S of the punch 120 in the first cutting process is preferably set to satisfy the relational expression of the following expression (1). More preferably, the stroke S of the punch 120 in the first cutting process is set to satisfy the following expression (2). It is noted that the phrase "the stroke S of the punch 120 in the first cutting process" refers to the amount of stroke when a position at which the blade contacts the workpiece 5 is taken as a starting point. set the stroke S of punch 120 in the first cutting process in this way, the end face portion can be increased M A / I / UOO I ¿or cut coated with the coating layer 5b and a good shape of the end face can be obtained. (Ri+R2)<S<{t-(R,+R2)} ... (1) (Ri+R2)x2<S<{t-(R,+R2)x2} ... (2) In addition, when the workpiece 5 is cut by performing a plurality of cutting processes, the front end radius Ri of the first cutting part 113 and the front end radius R2 of the second cutting part 123 can be made larger. small in a staggered manner in the respective cutting processes. That is, in the second cutting process, at least one operation between an operation that makes the front end radius Ri of the first cutting part 113 smaller than the front end radius Ri in the first cutting process and an operation that makes the front end radius R2 of the second cutting part 123 smaller than the front end radius R2 in the first cutting process is carried out; Next, the workpiece 5 is cut. Also in this case, similarly to the case of reducing the angle of the front end, an advantageous effect of being able to increase the portion covered by the coating layer 5b on the face of the workpiece is achieved. cut end and a good end face shape can be obtained. It is worth mentioning that when it is desired to reduce the load on the cutting tool 100 while making the coating layer 5b cover the cut end face after having suppressed the formation of cutting depressions during cutting of the workpiece 5 , a configuration can be adopted so that to increase the front end angle θι of the first cutting part 113 and the front end angle θ2 of the second cutting part 123 in a stepwise manner in the respective cutting processes. By changing a front end radius or a front end angle of a cutting part in a stepwise manner in the respective cutting processes in this way, the cutting can be controlled to obtain a good end face shape. In addition, it is also possible to gradually adjust the amount of metal coating covering the end face. For example, by reducing the front end radius or the front end angle in a stepwise manner, the metal coating can be spread over a wider region of the end face while reducing burrs on the end portion of the end face. extreme. Furthermore, by increasing the front end radius or the front end angle in a stepwise manner, the end face can be thinly coated with the metal coating leaving a large amount of metal coating on a portion of the cutting start point of the front end. extreme. By leaving a large amount of metal coating on the cutting start point part in this way, the occurrence of a situation where red oxide flows from the end face to the surface of the workpiece 5 can be suppressed. ΜΛ / I / UOO I ¿or b. Case where the shape of the cutting part is asymmetrical In the cutting tool 100, according to the present embodiment, the first cutting part 113 of the die 110 and the second cutting part 123 of the punch 120 have a wedge shape asymmetric with respect to a normal line at the front ends 113a. and 123a, as illustrated, in Figure 1. However, it is sufficient that the first cutting part 113 and the second cutting part 123 have at least a wedge shape asymmetric with respect to the normal line and preferably the shape of each of the first cutting part 113 and the second cutting part the part 123 meets the following conditions with respect to the shape. Front end angle The angle of the leading end 01 of the first cutting part 113 and the angle of the leading end 02 of the second cutting part 123 are preferably formed 10° or more and 120° or less. When the leading end angles Θi and θ2 are 10° or more, the inclination is large and therefore the ability of the coating layer 5b to follow the movement of the cutting parts is improved and the corrosion resistance is improved. of the cut end face is further improved. Furthermore, the stress applied to the cutting part 113 and the cutting part 123 is decreased, damage to the cutting edges is suppressed, and the durability of the tool is improved. Furthermore, when the leading end angles θι and θ2 are 120° or less, the load required to cut the workpiece 5 does not become too large and cracks are easily generated in the workpiece 5 when the respective cutting edges are pushed inward and thus the cutting of the workpiece 5 is facilitated. Therefore, the front end angle θι of the first cutting part 113 and the front end angle 02 of the second cutting part 123 are they are made 10° or more and 120° or less and, more preferably, they are made 30° or more and 90° or less. Furthermore, in the cutting tool 100, according to the present embodiment, the shapes of the first cutting part 113 and the second cutting part 123 are made asymmetric with respect to a normal line. For example, with respect to the front end angle θι of the first cutting part 113, the shape of the first cutting part 113 can be made asymmetric with respect to the normal line by making the left and right angles 0ia and 6ib (θι = 0ia + Oib), formed when the angle θι is divided in two by the normal line, different from each other. Similarly, with respect to the front end angle θ2 of the second cutting part 123, the shape of the second cutting part 123 can be made asymmetric with respect to the normal line by making the left and right angles 02a and 02b (θ2= 02a+ 02b), formed when the angle 02 is divided in two by the normal line, different from each other. An example is illustrated in Figure 10 in which the cutting part 113 of the die 110 and the cutting part 123 of the punch 120 are formed with asymmetric shapes by making the left and right angles 0ia and Oib, formed when the angle Oí is bisected by a normal line N, are different from each other and By making the left and right angles ΜΛ / t / ZUZ I / UOO I Zó right 62a and 62b, formed when the angle θ2 is divided in two by the normal line, are different from each other. By making the angles 0ia and Oib or the angles 02a and 02b different from each other you can control the direction of propagation of cracks that occur when cutting the workpiece 5. For example, by making an angle on one control side (0iao 0ib in the case of die 110 and 02ao 02b in the case of punch 120) in which it is desired that it does not cause burrs on the cutting end face of the workpiece 5 that is cut in two, is larger that the angle on the other side is easier for large cracks to propagate on the control side. As a result, the occurrence of burrs can be suppressed. At that point, it is desirable to make (0ia-0ib) or (0ib-0ia), which is the angular difference between angle 0ia and angle Oib, and (02a-02b) or (02b-02a), which is the difference angle between angle 02a and angle 02b, a value that is 5oo more and 45° or less. If the angular difference between the left and right angles is 5oo more, the direction of crack propagation on the workpiece 5 can be stably controlled. Furthermore, by making the angular difference between the left and right angles 45° or less, the loading of a vertical component of the load in the direction in which the cutting of the workpiece 5 advances, which is applied to the cutting part does not become too large and the durability of the cutting part can be guaranteed. Consequently, the angular difference (0ia-0ib) or (0ib-0ia) and the angular difference (02a-02b) or (02b-02a) between the left and right angles becomes a value that is 5oo plus and 45° or less, and more preferably 10° or more and 30° or less. front end radius In the cutting tool 100, according to the present embodiment, the shape of the first cutting part 113 and the shape of the second cutting part 123 are each made asymmetric with respect to a normal line. As mentioned above, with respect to the front end angle 0| of the first cutting part 113 and the front end angle 02 of the second cutting part 123, while the left and right angles 0,a and 0ib or the angles 02a and 02b, formed when the angle 0i or 02 is divided into two by the normal line, can be made different from each other, each of the shape of the first cutting part 113 and the shape of the second cutting part 123 can also be made asymmetric with respect to the normal line by making the radii of the right and left front ends Riay Rib or the front end radii R2a and R2b, which are formed when the front end radius is divided into two by the normal line, are different from each other. In Figure 11, an example is illustrated in which the cutting part 113 of the die 110 and the cutting part 123 of the punch 120 are formed with an asymmetric shape by making the radii of the right and left front ends Riay Rib and the front end radii R2a and R2b, which are formed when the front end radius is bisected by a normal line N, are different from each other. ΜΛ / I / UOO I ¿or By making the front end spokes Riay Rib or the front end spokes R2a and R2b different from each other, the direction of crack propagation can be controlled when cutting the workpiece 5. For example, by making a radius of the front end on a control side (Ría or Rib in the case of die 110 and R2ao R?b in the case of punch 120) in which it is desired not to cause burrs on the face of the cut end of the workpiece 5 that is cut in two, be smaller than the front end radius on the other side it is easier for large cracks to propagate on the control side. As a result, the appearance of burrs can be suppressed. Here, the leading end radius Ri of die 110 is taken as the average value of the respective leading end radii Riay Rib formed when the leading end radius is bisected by the normal line at the cutting edge of the die 110. relevant cut (Ri = {(Ria+Rib) / 2}). Similarly, the leading end radius R2 of punch 120 is taken as the average value of the respective leading end radii R2a and R2b formed when the leading end radius is bisected by the normal line at the cutting edge of the part. relevant cutoff (R2= {(R2a+ R2b) / 2}). At this time, preferably, the front end radii Ri and R2 are each made 0.5% or more and 35.0% or less of the sheet thickness value t. When the front end radii Ri and R2 are each 0.5% or more of the value of the sheet thickness t, the stress applied to the cutting edges of the cutting part 113 and the cutting part 123 does not become too much. large, damage to each of the cutting edges is suppressed and durability is improved. Furthermore, when the front end radii Ri and R2 are each 35.0% or less of the sheet thickness value t, the shape of the cut end face will be good. In addition, since it is easy for cracks to occur in the workpiece 5 when the cutting edges are pressed, the cutting of the workpiece 5 is facilitated. Therefore, the front end radius Ri of the first cutting part 113 and the front end radius R2 of the second cutting part 123 are each made 0.5% or more and 35.0% or less of the sheet thickness value t and, more preferably, 3.0% or more and 10.0% or less of the value of the thickness of the sheet t. At that time, it is desirable to make a relationship Ria / Rib or Rib / Ria between the radii of the front ends on the left and right of the first cutting part 113 and a relationship R2a / R2b or R2b / R2abetween the radii of the left and right front ends of the second cutting part 123 a value that is 1.1o more and 100 or less. If the ratio of the front end radii Ra and Rb on the left and right is 1.1 or more, the direction of crack propagation on the workpiece 5 can be stably controlled. In addition, by making the ratio between the front end radii Ra and Rb on the left and right 100 or less, the load of a vertical component of the load in the direction in which the cutting of the workpiece progresses 5 which is applied to the cutting part does not become too large and the durability of the cutting part can be guaranteed. Consequently, the relationships M A / I / UOO I or between the left and right front end spokes (Ria / Rib or Rib / Ria and R2a / R2b or R2b / R2a) are made 1.1o more and 100 or less and, more preferably, 5 or more and 20 or less. In this case, although the first cutting part 113 and the second cutting part 123 may have symmetrical shapes with respect to the workpiece 5, as illustrated in Figure 1 and the like, they may also have shapes different from each other. For example, in the first cutting part 113 and the second cutting part 123, if at least one of the front end angles 0iay 0ib or 02ay 02b to the left and right and the front end radii Riay Rib or R2ay R2b on the left and right are different from the other angles or radii, the first cutting part 113 and the second cutting part 123 will have different shapes from each other. By making the first cutting part 113 and the second cutting part 123 have a different shape from each other, the relationship of the fracture surface can be changed. It is worth mentioning that the fracture surface ratio is the ratio between the fracture surface s5 and the thickness of the workpiece sheet 5. Amount of deviation between front positions The position of the front end 113a of the first cutting part 113 and the position of the front end 123a of the second cutting part 123 can be made to coincide in a horizontal direction perpendicular to the direction in which the die 110 and the punch 120 are facing each other (i.e., the direction of the sheet thickness of the workpiece 5), as illustrated in Figure 1 and Figure 2. By causing the position of the front end 113a of the first cutting part 113 and the position of the front end 123a of the second cutting part 123 match, a force in the X direction applied to the cutting part 113 and the cutting part 123 can be reduced, thereby improving durability. Furthermore, cracks may be generated from the cutting edge at a suitable time to complete the cut. Alternatively, as illustrated in Figure 12, the position of the front end 113a of the first cutting part 113 and the position of the front end 123a of the second cutting part 123 may deviate from each other by a deviation amount x in the direction horizontal. The phrase “deflection amount the X direction) which is perpendicular to the direction in which the first cutting part 113 and the second cutting part 123 face each other. The amount of deviation between the front end positions is preferably 50% or less of the sheet thickness value t. If the amount of deviation between the front end positions is 50% or less of the sheet thickness value t, the workpiece 5 can be cut in such a way that the desired properties of the face of the workpiece are reliably obtained. extreme. Trim Width M A / I / UOO I The phrase “trimming width D of workpiece 5” refers to a length of workpiece 5 that must be left from the cutting position in the direction of the length of the sheet (X direction) when cutting with the cutting tool 100. For example, as illustrated in Figure 7, the trimming width D of the workpiece 5 is represented by the length from the cutting position to one of the end portions of the workpiece 5 As illustrated in Figure 12, in a case where the position of the front end 113a of the first cutting part 113 and the position of the front end 123a of the second cutting part 123 deviate from each other, it is enough to take the width of cutout D of the workpiece 5 such as, for example, the length of an end portion of the workpiece 5 to the position of the front end of the cutting part on the side closest to the relevant end portion. It is seen that, in Figure 7, a pad 140 is arranged between the die 110 and the workpiece 5 on the side opposite to the side on which the cutout width D of the workpiece 5 is taken. The pad 140 It functions similarly to the pads 131, 132, 133 and 134 of the blank holder 130 illustrated in Figure 3. The cutting width D of the workpiece 5 is equal to or greater than the front end radius R of the cutting part and is 5 times or less than the sheet thickness t of the workpiece 5 (R<D< 5t) and, in particular, it is preferably 3 times or less the thickness of the sheet t of the workpiece 5 (R<D<3t). More preferably, the cutout width D of the workpiece 5 is 3 times or more of the front end radius R of the cutting part and is equal to or less than the sheet thickness t of the workpiece 5 (3R <D<t). It is worth mentioning that, the front end radius R of the cutting part is taken as the smallest radius between the front end radii Riay Rib on the left and right of the first cutting part 113 and the front end radii R2a and R2b on the left and right of the second cut part 123 (R = Min(Ria, Rib, R2a, R2b))· By setting the cutting width D to be 5 times or less the thickness of the sheet t and, more preferably, 3 times or less the thickness of the sheet t, the formation of the fracture surface s5 due to cutting and the fracture surface ratio can be reduced. On the other hand, by setting the trimming width D to be equal to or greater than the front end radius R of the cutting part, and in particular, to be 3 times or more of the front end radius R, the offset can be suppressed. of the cutting edge due to the elastic deformation of the tool during cutting and a good shape of the end face can be obtained by cutting. The reason for this is as described above according to Figure 8 and Figure 9. By changing the shape of the first cutting part 113 of the die 110, the shape of the second cutting part 123 of the punch 120, the amount of deviation between the positions of the front ends of the respective cutting parts 113 and 123 or the trimming width D of workpiece 5 in this way, changes the shape of the cut end face of workpiece 5 cut by the cutting tool M A / I / UOO I 100 and changes the covering state of the cut end face by the coating layer 5b. Therefore, it is sufficient to properly establish the shape of the first cutting part 113 of the die 110 and the shape of the second cutting part 123 of the punch 120, the amount of deviation between the positions of the front ends of the respective parts of cutting 113 and 123 and the trimming width D of the workpiece 5, according to the shape of the cut end face or the corrosion resistance required for the workpiece 5 after cutting. For example, the corrosion resistance of the cut end face can be increased by making the first cutting portion 113 of the die 110 and the second cutting portion 123 of the punch 120 having the same asymmetrical shape from left to right and causing them to the position of the front end 113a of the first cutting part 113 and the position of the front end 123a of the second cutting part 123 coincide so that the first cutting part 113 and the second cutting part 123 are arranged symmetrically with respect to each other. the workpiece 5. This is because the cut end face will be symmetrical with respect to the central position of the sheet thickness and the extent to which the coating layer 5b on the bottom surface side of the workpiece workpiece 5 extends on the inclined face s3 and the extent to which the coating layer 5b on the side of the upper surface of the workpiece 5 extending on the inclined face s4 will be approximately equal. Furthermore, for example, in the case of welding the cut end face it is desirable that the cut end face be flat from the point of view of facilitating the welding work. In this case, the first cutting part 113 of the die 110 and the second cutting part 123 of the punch 120 may have different wedge shapes to improve the flattening of the cut end face. Height of cutting parts It is sufficient to establish a height hi of the first cutting part 113 and a height h2 of the second cutting part 123 so that, similarly to the case where the shapes of the cutting parts are symmetrical, at least the sum of these heights (hi+h2) is greater than the thickness of the sheet t of the workpiece 5. Therefore, the cutting tool 100 may be composed of the die 110 and the punch 120 having the wedge-shaped cutting parts 113 and 123 with an asymmetrical shape from left to right, respectively. By cutting the workpiece 5 by means of the wedge-shaped cutting parts 113 and 123, the coating layer 5b on the respective surfaces of the metal material 5a can be made to follow the movement of the cutting parts 113 and 123 and extends over the cut end face. Each of the inclined faces s3 and s4 of the cut end face is coated with the coating layer 5b continuously from the respective surfaces of the metal material 5a, so that the amount of coating layer covering the end face sheared decreases towards the fracture surface s5. Therefore, the corrosion resistance of the cut end face can be improved while M A / I / UOO I ¿ó maintains the corrosion resistance of the flat surface of the workpiece 5. Furthermore, in the cutting tool 100, according to the present embodiment, because the cutting parts 113 and 123 of the die 110 and the punch 120 has shapes that are asymmetric with respect to the normal line at the front ends 113a and 123a, the direction of crack propagation when cutting the workpiece 5 can be controlled. It is noted that cutting the workpiece 5 with the cutting tool 100 can be carried out by performing a single cutting process or can be carried out by performing a plurality of cutting processes. The phrase "cutting carried out by performing a plurality of cutting processes" refers to executing a cutting process in which the die 110 is pushed downward relative to the punch 120 a plurality of times to thereby cut the workpiece 5. in two pieces. Various types of cut end faces can be made when cutting the workpiece 5, performing a plurality of cutting processes. 2. Second modality Next, a method for cutting a workpiece according to a second embodiment of the present invention will be described. The method for cutting a workpiece, according to the present embodiment, refers to a cutting process that cuts, from the workpiece 5, a closed-shaped region (hereinafter also referred to as "closed region") , whose edge is defined by a curved line when the workpiece 5 is viewed in plan, as in the case of performing, for example, a drilling or punching. Studies similar to those in the case of linearly cutting a workpiece as described in patent document 1 have also been carried out with respect to said cutting process. For example, Patent Document 5 describes a punching method in which, before punching a Zn-based metal-coated steel sheet, quick-drying oil is applied to a planned drilling location on the surface. of the Zn-based metal coated steel sheet, and then punching the corresponding place is carried out so that the quick-drying oil moves around the punched end face. According to the method described in patent document 5, because quick-drying oil is applied to the planned drilling location on the surface of the Zn-based metal coated steel sheet before drilling, the drying oil fast moves around the drilled end face during drilling and therefore a decrease in the corrosion resistance of the end face is suppressed. Furthermore, patent document 6 describes a method of cutting a coated steel sheet in which, when cutting a coated steel sheet, a punch is used in which a corner portion composed of a surface of elliptical arc having a major axis along M A / I / UOO I ¿o of the radial direction of the punch and a minor axis along the axial direction of the punch are provided at the cutting edge of the punch and a portion where the coating film has been peeled off is made to be include on one side of metallic debris, by making the major axis larger than the amount of expansion toward the outer diameter side of the punch from the portion where the coating film has been peeled off. According to the method described in Patent Document 6, the occurrence of a situation where a portion of the coating film has been peeled off remains on the coated steel sheet after cutting can be avoided and the generation of enamel hairs caused by a portion where the film coating has peeled off. However, in the method described in the aforementioned patent document 1, the metal coating layer on the surface of the base metal material covers only at least a part of the cut surface of the cut end face only and the material of the base metal remains exposed at the fracture surface. Consequently, the corrosion resistance of the cut end face of the metal coated metal sheet is not sufficient. Furthermore, in general, when attempting to impart excessive sacrificial protection property to the cut end face for the purpose of preventing oxidation, the metallic coating of the surface of the metal-coated metal sheet is reduced and the Surface corrosion resistance (that is, flat surface corrosion resistance) of the surface of metal coated metal sheet. Furthermore, in the method described in the aforementioned patent document 5, it is necessary to apply quick-drying oil to a planned punching location on the surface of the Zn-based metal-coated steel sheet. In addition, when the thickness of the Zn-based metal coated steel sheet is thick, it is difficult for the quick-drying oil to move to the entire area of ​​the drilled end face, and therefore after drilling it is You need to apply quick drying oil on the drilled end as well. The method described in the aforementioned patent document 6 is a method of ensuring that a coating film does not peel off from a cutting depression in a coated steel sheet after cutting and is not a technique that covers a cut surface with a coating film. Therefore, a coating film is not adhered to the cut surface of the coated steel sheet and a function that is performed by a coating film adhered to the cut surface is not exhibited. Therefore, in the method for cutting a workpiece according to the present embodiment, with respect to a cutting process for cutting a closed region of the workpiece 5 also, when cutting a workpiece that was subjected to a surface treatment, while maintaining the function of the coating material on a flat surface of the base material, it is also possible to make the function of the coating material on the cut end face. TO ΜΛ / I / UOO I ¿o Next, the method for cutting a workpiece, according to the present embodiment, will be described in detail. 2-1. Case where the part where the closed region of the workpiece was removed will be used as the product (drilling) 1. Cutting method First, a method for cutting a workpiece according to the second embodiment of the present invention will be described based on Figure 13 to Figure 17. Figure 13 is a plan view illustrating cutting positions on a workpiece. of work 5, in accordance with this modality. Figure 14 is an explanatory drawing illustrating a process for forming an intermediate material in the cutting method, according to the present embodiment. Figure 15 is an explanatory drawing illustrating a cutting process in the cutting method, according to the present embodiment. Figure 16 is an explanatory drawing illustrating an example of a cutting tool 100 used in the cutting process according to the present embodiment and illustrating a state before cutting the workpiece 5. Figure 17 is an explanatory drawing illustrating illustrates a state after cutting the workpiece 5 using the cutting tool 100 illustrated in Figure 16. Figure 16 and Figure 17 schematically illustrate the cutting tool 100 and the workpiece 5 illustrated in Figure 15. It is noted that, in the cutting method according to the present embodiment, the workpiece 5 that has been subjected to surface treatment is cut. In the following description, a surface-treated material having a coating layer (the coating layer 5b illustrated in Figure 4) on the surface of a metallic material (the metallic material 5a in Figure 4) is adopted as an example. is a base material of the workpiece 5. Examples of this type of workpiece include a metal coated metal sheet obtained by subjecting the surface of a metal sheet to a metal coating treatment, a painted metal sheet obtained by coating the surface of a metal material as a base material with paint and a metal sheet with laminated film, obtained by laminating a film on a metal sheet. The cutting method, according to the present embodiment, is a method for cutting a closed region of the workpiece 5 from the workpiece 5. As an example of this type of cutting method, in the present embodiment A cutting method is used when a portion in which a closed region of the workpiece 5 has to be removed and a through hole is formed to be used as a product, as in the case of drilling holes described. It is sufficient that the closed region be a shape represented by a curved line (and may include a straight line) and, for example, the closed region may have a shape such as a circle or an ellipse. The cutting method, according to the present embodiment, includes a process of forming an intermediate material from the workpiece 5 and a process of cutting the intermediate material to MA / I / UOO I ¿or acquire a portion to be used as product. For example, in the case of cutting a closed circular region of the workpiece 5 illustrated in Figure 13, first, in the process of forming the intermediate material from the workpiece 5, the workpiece 5 is cut at a cutting position Pl, so as to form an intermediate material in which the inner side portion of the cutting position Pl has been removed. The cutting position Pl is set more on the inner side than a cutting position P2 in the one that will finally cut the intermediate material. Next, in the process of cutting the intermediate material, the intermediate material is cut at the cutting position P2 at which the intermediate material is desired to be finally cut. The intermediate material is cut using a cutting tool in which a wedge-shaped cutting part is provided on a die and a punch. Therefore, in the cutting method, according to the present embodiment, when cutting an intermediate material using wedge-shaped cutting parts to create the shape of the final product, as illustrated in Figure 4, the end face The cut part of the workpiece 5 after cutting can be covered with the coating layer 5b. Therefore, the corrosion resistance of the cut end face can be improved while maintaining the corrosion resistance of the flat surface of the workpiece 5. In addition, before cutting the workpiece 5 in the position of cut P2 in which the final cut is desired, the closed region is cut to leave a surplus region. In this way, by cutting the closed region at the cutting position P2, because a space for the material to move in can be ensured, the workpiece 5 can be cut reliably. Intermediate material formation process An example of the process of forming the intermediate material from the workpiece 5 is illustrated in Figure 14. In Figure 14, the workpiece 5 is cut at the cutting position Pl using a cutting tool 50 having a die 51 and a punch 52. The die 51 is a tubular member having a through hole with a shape corresponding to the closed region to be cut at the cutting position Pl. The punch 52 is a member that must inserted through the die passage hole 51 and having a shape corresponding to the internal space of the die passage hole 51. By pushing down the punch 52 in a state in which the workpiece 5 has been placed in the die 51, the closed region is cut at the cutting position Pl of the workpiece 5. As a result, as illustrated on the lower side of Figure 14, the workpiece 5 is obtained in which a se has formed the passage hole. The obtained workpiece 5 is used as an intermediate material. The through hole in the intermediate material is formed on the inner side of the cutting position P2 in which the final cut is desired to be made. When the region of the workpiece 5 to be obtained by cutting the intermediate material at the cutting position P2 in the following process is assumed to be the final shape region, the cutting position Pl is set to the opposite side of the region final shape, along the edge of the final shape region (ie, the cut position P2). In other words, in addition to M A / I / UOO I ¿or the final shape region, the intermediate material also has, as an excess zone, a portion between the cutting position P2 and the cutting position Pl. The excess region is cut in the following process. By forming the intermediate material in this way, when the intermediate material is cut at the cutting position P2 in the next process, it is possible that the material moves to the side of the through hole. It is worth mentioning that the method of forming the intermediate material from the workpiece 5 is not limited to the method using the cutting tool 50 illustrated in Figure 14 and can be carried out using laser cutting or other cutting method. Cutting process An example of the process for cutting the intermediate material is illustrated in Figure 15. The cutting tool 100 for cutting the intermediate material has, as illustrated in Figure 15, a die 110 having a first cutting part 113 in the shape of wedge on a base 111 and a punch 120 having a second wedge-shaped cutting part 123 on a base 121. The first cutting part 113 and the second wedge-shaped cutting part 123 are created in a corresponding closed shape to the cutting position P2. For example, in a case where the cutting position P2 is circular, as illustrated in Figure 15, the first cutting part 113 and the second wedge-shaped cutting part 123 are created in a circular shape. As illustrated in Figure 16, the workpiece 5 to be cut by the first cutting part 113 of the die 110 and the second cutting part 123 of the punch 120 is arranged between the die 110 and the punch 120. For For example, the workpiece 5 is placed on the die 110. At that time, the die 110 and the punch 120 are installed so that the first cutting part 113 and the second cutting part 123 are facing each other. Then, in a state where the workpiece 5 has been placed on the die 110, the punch 120 is pushed down relatively with respect to the die 110 so that the workpiece 5 is cut at the cutting position P2. , as illustrated in Figure 17. As illustrated on the lower side in Figure 15, in the workpiece 5 that was cut by the cutting tool 100, the excess region has been removed and only the shape region remains. final. The cutting tool 100, according to the present embodiment, is configured so that, when the punch 120 is pushed towards the die 110 by means of the tensile forces arising between the first cutting part 113 and the second part of cut 123 and the workpiece 5, the coating layer on the respective surfaces of the workpiece 5 is made to extend over the cut end face so that the cut end face is covered with the coating layer. That is, the coating layer on the respective surfaces of the workpiece 5 is made to follow the movements of the first cutting part 113 and the second cutting part 123 with respect to the workpiece 5 when the punch 120 is pushed into the die 110 and the coating layer is caused to M A / I / UOO I ¿ó spread over the face of the cut end. Thus, the cut end face of the workpiece 5 can be coated with the coating layer. 2. Coating the cut end face with a coating layer The cut end face of the workpiece 5 that was cut by the cutting tool 100 is, as illustrated in Figure 4, similar to the first embodiment. As illustrated in Figure 4, the cut end face of the workpiece 5 is composed of cutting depressions si and s2, inclined faces s3 and s4 and a fracture surface s5. The cutting depression si and the inclined face s3 are formed by the first cutting part 113 of the die 110 and the cutting depression s2 and the inclined face s4 are formed by the second cutting part 123 of the punch 120. The fracture surface s5 is formed as a result of the breakage of the workpiece 5 in a manner in which the cracks generated in the workpiece 5 by the first cutting part 113 and the second cutting part 123 serve as starting points. As illustrated in Fig. 4, the coating layer 5b on the upper surface side of the metal material 5a covers the metal material 5a continuously from the surface of the metal material 5a to the cutting depression si and the inclined face s3. Similarly, the coating layer 5b on the lower surface side of the metal material 5a covers the metal material 5a continuously from the surface of the metal material 5a to the cut depression s2 and the inclined face s4. Thus, in the workpiece 5 that was cut by the cutting tool 100, according to the present embodiment, the region from each surface of the metal material 5a to the cut end face is covered with the same continuous coating layer 5b. . For example, after cutting the workpiece 5, it is possible to cover the cut end face by subjecting the cut end face to a surface treatment such as metal coating or painting. However, it is difficult to cover the cut end face with a material having the same composition as the coating layer 5b of the workpiece 5, and the corrosion resistance of the cut end face will be low compared to the surface. of metallic material 5a. On the contrary, because the workpiece 5 that was cut by the cutting tool 100, according to the present embodiment, is covered from each surface up to the cut end face of the metallic material 5a with the same coating layer continuous 5b simultaneously with cutting, it is difficult for the cut end face to be oxidized. Therefore, by cutting the workpiece 5 using the cutting tool 100, according to the present embodiment, the workpiece 5 having a high corrosion resistance on the cut end face can be provided. It is worth mentioning that the shape of the cut end face of the workpiece 5 that was cut by the cutting tool 100, according to the present embodiment, depends on the shape of the first cutting part 113 and the second part of cut 123. Because the first cutting part 113 and the second cutting part 123 each have a wedge shape, the shape on the cut end face ΜΛ / I / UOO I ¿ó of the workpiece 5 is a shape having inclined faces s3 and s4 along the wedge-shaped inclinations, as illustrated in Figure 4, and not a cutting surface vertical as illustrated in Figure 36. Therefore, for example, the cut end face of the workpiece 5 that was cut by the cutting tool 100 illustrated in Figure 15 has a shape that protrudes progressively in the direction towards the center in the radial direction. By making the shape of the first cutting part 113 and the second cutting part 123 wedge-shaped, when cutting the workpiece 5 it is easy for the coating layer 5b on the surfaces of the metal material 5a to follow the movements of the first cutting part 113 and the second cutting part 123 along the slopes of the wedge shape. As a result, as illustrated in Figure 4, the coating layer 5b on the surfaces of the metal material 5a can be made to follow the movements of the first cutting part 113 and the second cutting part 123 to the inclined faces s3 and s4. of the face of the cut end and not just the cut depressions si and s2. Furthermore, because the cutting depressions si and s2 are formed on both the front and rear surfaces of the workpiece 5 by the cutting part 113 and the cutting part 123, a cutting surface without burrs is formed. Furthermore, the coating layer 5b on the surface of the metal material 5a follows the inclinations of the first cutting part 113 and the second cutting part 123 to move to the cut end face. At this time, the amount of the coating layer 5b covering the surfaces of the inclined faces s3 and s4 of the cut end face gradually decreases towards the fracture surface s5, as illustrated in Figure 4. By making the coating layer 5b covers the inclined faces s3 and s4 in this way, even if the area of ​​the cut end face of the metal material 5a, which is coated with the coating layer 5b, increases, the amount of the coating layer 5b that covers the surface of the metal material 5a moving towards the cut end face hardly increases, and therefore the corrosion resistance of the flat surface of the workpiece 5 can be maintained. It should be mentioned that since the fracture surface s5 is a surface that is formed as a result of cracks causing the workpiece 5 to break, it is difficult to make the coating layer 5b extend to the fracture surface s5. However, because the workpiece 5 is cut along the inclined surfaces of the first cutting part 113 and the second cutting part 123 until it enters a state in which a front end 113a of the first cutting part 113 and a leading end 123a of the second cutting part 123 substantially come into contact with each other, the proportion of the cut end face representing the fracture surface s5 is very small. Therefore, even if the fracture surface s5 is not covered with the coating layer 5b, the corrosion resistance is not significantly reduced. Furthermore, by making the first cutting part 113 of the die 110 and the second cutting part 123 of the punch 120 wedge-shaped as in the cutting tool 100, according to the present ΜΛ / I / UOO I ¿O mode, it is also possible to cut, for example, a material that has a tensile strength of 200 MPa or more or a thick material. Furthermore, it is possible to cut a material having a tensile strength of 270 MPa or more and, furthermore, a material having a tensile strength of 590 MPa or more. 3. Shape of the cutting parts of the cutting tool In the cutting tool 100 for cutting an intermediate material used in the cutting method, according to the present embodiment, the first cutting part 113 of the die 110 and the second cutting part 123 of the punch 120 have the same wedge shape. , as illustrated in Fig. 16. However, it is sufficient that each of the first cutting part 113 and the second cutting part 123 have at least one wedge shape, and preferably that the shape of each of the first cutting part 113 and the second cutting part 123 satisfy the following conditions with respect to the shape. Front end angle A leading end angle θι of the first cutting part 113 and a leading end angle 02 of the second cutting part 123 are preferably formed to be 10° or more and 120° or less. When the leading end angles θι and 02 are 10° or more, the inclination is large, and therefore the ability of the coating layer 5b to follow the movement of the cutting parts is improved and the resistance to Corrosion of the cut end face is further improved. Furthermore, the stress applied to the cutting part 113 and the cutting part 123 is decreased, damage to the cutting edges is suppressed, and the durability of the tool is improved. In addition, when the angles of the leading ends 01 and θ2 are 120° or less, the load required to cut the workpiece 5 does not become too large and cracks are easily generated in the workpiece 5 when the respective cutting edges are pushed inward and thus the cutting of the workpiece 5 is facilitated. Therefore, the front end angle θι of the first cutting part 113 and the front end angle 02 of the second cutting part 123 are They are made of 10° or more and 120° or less and, more preferably, they are made of 30° or more and 90° or less. front end radius A front end radius Ri of the first cutting part 113 and a front end radius R2 of the second cutting part 123 are preferably formed to be 0.5% or more and 35.0% or less of the value of a thickness of the sheet t. When the leading end radii Ri and R2 are each 0.5% or more of the value of the sheet thickness t, the stress applied to the cutting edges of the cutting part 113 and the cutting part 123 does not become too large. large, damage to cutting edges is suppressed and durability is improved. In addition, when the leading end radii Ri and R2 are each 35.0% or less of the sheet thickness value t, the shape of the cut end face will be good. In addition, since cracks will be easily generated in the workpiece 5 when the respective cutting edges are pushed, cutting of the workpiece 5 will be further facilitated. Therefore, the radius of the M A / I / UOO I ¿or front end Ri of the first cutting part 113 and the radius of the front end R2 of the second cutting part 123 are made 0.5% or more and 35.0% or less of the value of the sheet thickness t and, more preferably, 3.0% or more and 10.0% or less of the sheet thickness value t are made. In this case, the first cutting part 113 and the second cutting part 123 may have different shapes from each other. For example, if at least one of the front end radii R, and R2 or the front end angles θι and θ2 is different, the first cutting part 113 and the second cutting part 123 will have different shapes from each other. By making the first cutting part 113 and the second cutting part 123 have a different shape from each other, the relationship of the fracture surface can be changed. It is worth mentioning that the fracture surface ratio is the ratio between the fracture surface s5 and the thickness of the workpiece sheet 5. At that time, the ratio between the leading end radius Ri of the first cutting part 113 and the leading end radius R2 of the second cutting part 123 (ratio of leading end radii Ri / R2 or R2 / Ri) is preferably less than 100, and more preferably it is less than 10. Most preferable is a case where the leading end radii Ri and R2 are equal. It should be mentioned that, the magnitude relationship between the leading end radius Ri of the first cutting part 113 and the leading end radius R2 of the second cutting part 123 is not particularly limited. Further, the ratio between the leading end angle θι of the first cutting part 113 and the leading end angle θ2 of the second cutting part 123 (ratio of leading end angles θ 1 / Θ2 or 02 / 01) is preferably less than 4 and, more preferably, it is less than 2. Most preferable is a case where the front end angles θι and Θ2 are equal. It is noted that the magnitude relationship between the front end angle 0 of the first cutting part 113 and the front end angle 02 of the second cutting part 123 is not particularly limited. By setting the front end radius ratio R1 / R2 or R2 / Ri and the front end angle ratio Θ1 / Θ2 or Θ2 / Θ1 within the above ranges, the surface area ratio can be reduced. fracture. When at least one of the front end radii and the front end angles differ significantly between the first cutting part 113 and the second cutting part 123, cutting will be carried out first by one of the cutting parts and, by Therefore, the deformation of workpiece 5 will be concentrated. As a result, the breakage of workpiece 5 will occur earlier and the failure surface ratio will increase and consequently the end face ratio will decrease. cut which is coated with the coating layer 5b. Therefore, by setting the front end radius ratio R1 / R2 or R2 / R1 and the front end angle ratio Θ1 / Θ2 or Θ2 / Θ1 to be within the aforementioned ranges, the the fracture surface may decrease. Amount of deviation between front end positions ΜΛ / I / UOO I ¿or The position of the front end 113a of the first cutting part 113 and the position of the front end 123a of the second cutting part 123 can be made to coincide in a horizontal direction perpendicular to the direction in which the die 110 and the punch 120 are facing each other (i.e., the direction of the sheet thickness of the workpiece 5), as illustrated in Figure 16 and Figure 17. By causing the position of the front end 113a of the first cutting part 113 and the position of the front end 123a of the second cutting part 123 to match, a force in the X direction applied to the cutting part 113 and the cutting part 123 can be reduced, thereby improving durability. Furthermore, cracks may be generated from the cutting edge at a suitable time to complete the cut. Alternatively, as illustrated in Figure 18, the position of the front end 113a of the first cutting part 113 and the position of the front end 123a of the second cutting part 123 may deviate radially from each other by a deviation amount x. The phrase “deflection amount the X direction) which is perpendicular to the direction in which the first cutting part 113 and the second cutting part 123 face each other. The amount of deviation between the front end positions is preferably 50% or less of the sheet thickness value t. If the amount of deviation between the leading end positions is 50% or less of the sheet thickness value t, the workpiece 5 can be cut in such a way that the desired properties of the face of the workpiece are reliably obtained. extreme. Trim Width The phrase “trimming width D of workpiece 5” refers to the length of workpiece 5 that must be left from the cutting position P2 in the opposite direction to the final shape region when cutting with the tool cutting width 100. That is, the trimming width D of the workpiece 5 is the length of the excess region (distance between cutting position P1 and cutting position P2) of the intermediate material and, as illustrated in the Figure 16, is represented by the length from the cutting position to one of the end portions of the workpiece 5. As illustrated in Figure 18, in a case where the position of the front end 113a of the first part of cutting 113 and the position of the front end 123a of the second cutting part 123 deviate from each other, it is sufficient to take the cutting width D of the workpiece 5 as, for example, the length from an end part of the workpiece 5 to the front end position of the cutting part on the side closest to the relevant end part. The cutting width D of the workpiece 5 is equal to or greater than the front end radius R of the cutting part and is 5 times or less than the sheet thickness t of the workpiece 5 (R<D< 5t) and, in particular, is preferably 3 times or less the thickness of the sheet t of the workpiece ΜΛ / I / UOO I ¿ó (R<D<3t). More preferably, the cutout width D of the workpiece 5 is 3 times or more of the front end radius R of the cutting part and is equal to or less than the sheet thickness t of the workpiece 5 (3R <D<t). It is worth mentioning that the phrase “front end radius R of the cutting part” refers to the front end radius Ri of the first cutting part 113 or the front end radius R2 of the second cutting part 123. In one case where the front end radii Ri and R2 are equal, R = Ri = R2. In a case where the front end radius Ri and R2 are different from each other, the smallest radius between the front end radius Ri of the first cutting part 113 and the front end radius R2 of the second cutting part 123 is takes R as the front end radius (R = Min(Ri, R2)). By setting the trim width D to be 5 times or less of the sheet thickness t, and more preferably 3 times or less of the sheet thickness t, the formation of the fracture surface s5 due to cutting can be suppressed and the can reduce the fracture surface ratio. On the other hand, by setting the trimming width D to be equal to or greater than the leading end radius R of the cutting part, and in particular to be 3 times or more of the leading end radius R, the displacement of the cutting edge due to elastic deformation of the tool during cutting and a good shape of the end face can be obtained by cutting. The reason for this is as described above according to Figure 8 and Figure 9. By changing the shape of the first cutting part 113 of the die 110, the shape of the second cutting part 123 of the punch 120, the amount of deviation between the positions of the leading ends of the respective cutting parts 113 and 123 or the trim width D of the workpiece 5 in this way, changes the shape of the cut end face of the workpiece 5 cut by the cutting tool 100 and changes the coverage state of the cut end face by the coating layer 5b. Therefore, it is enough to properly set the shape of the first cutting part 113 of the die 110 and the shape of the second cutting part 123 of the punch 120, the amount of deviation between the positions of the leading ends of the respective parts of cut 113 and 123 and the cut width D of the workpiece 5 according to the shape of the cut end face or the corrosion resistance that is required for the workpiece 5 after cutting. For example, the corrosion resistance of the cut end face can be increased by making the first cutting part 113 of the die 110 and the second cutting part 123 of the punch 120 have the same shape and causing the position of the leading end 113a of the first cutting part 113 and the position of the front end 123a of the second cutting part 123 coincide, so that the first cutting part 113 and the second cutting part 123 are arranged symmetrically with respect to the workpiece 5 This is because the face of the cut end will be symmetrical with respect to the center position of the thickness of the sheet and the extent to which the coating layer 5b on the surface side M A / I / UOO I ¿ó bottom of the workpiece 5 extends over the inclined face s3 and the extent to which the coating layer 5b on the upper surface side of the workpiece 5 extends over the face slope s4 will be approximately equal. Further, for example, in the case of making the face of the cut end flat, a configuration can be adopted in which the first cutting part 113 of the die 110 and the second cutting part 123 of the punch 120 have different wedge shapes from each other. Yes, to improve the flattening of the cut end face. Height of cutting parts Similarly to the first modality, it is sufficient to establish a height hi of the first cutting part 113 and a height hz of the second cutting part 123 such that at least the sum of these heights (hi+h?) is greater than the sheet thickness t of the workpiece 5. The cutting method, according to the present embodiment, has been described above. According to the present embodiment, first, in a process for forming the intermediate material from the workpiece 5, the intermediate material is formed by removing the portion of the inner side of the cutting position P1 that is placed beyond on the inner side than the cutting position P2, in which you want to make the final cut. In this way, by cutting the closed region at the cutting position P2, because a space for the material to move in can be ensured, the workpiece 5 can be cut reliably. Next, in the process of cutting the intermediate material, the intermediate material is cut at the cutting position P2 where the final cut is desired to be made. In the process of cutting the intermediate material, as illustrated in Figure 15, the cutting tool 100 having the die 110 and the punch 120, which have the wedge-shaped cutting parts 113 and 123, is used. By cutting the workpiece 5 by means of the wedge-shaped cutting parts 113 and 123, the coating layer 5b on the respective surfaces of the metal material 5a can be made to follow the movements of the cutting parts 113 and 123 and extends over the cut end face. The inclined faces s3 and s4 of the cut end face are each coated with the coating layer 5b continuous from the respective surfaces of the metallic material 5a so that the amount of coating layer covering the cut end face decreases. towards the fracture surface s5. Therefore, the corrosion resistance of the cut end face can be improved while maintaining the corrosion resistance of the flat surface of the workpiece 5. 4. Plugin Cutting of intermediate material by plurality of cutting processes Cutting the workpiece 5 with the cutting tool 100 used in the intermediate material cutting process described above can be carried out by performing a single cutting process or by performing a plurality of cutting processes. The phrase “cut by making a plurality” M A / I / UOO I "or cutting processes" refers to executing a cutting process in which the die 110 is pushed downward relative to the punch 120 a plurality of times to thereby cut the workpiece 5 in two. parts. Various types of cutting end faces can be made by cutting the workpiece 5 by performing a plurality of cutting processes. For example, when the workpiece 5 is cut by performing a plurality of cutting processes, the front end angle 0i of the first cutting part 113 and the front end angle 02 of the second cutting part 123 can gradually become larger. small in the respective cutting process. As a more specific description, it will be assumed that the plurality of cutting processes includes a first cutting process and a second cutting process that is performed after the first cutting process. At that time, in the second cutting process, at least one operation is performed among an operation that makes the front end angle 0, of the first cutting part 113 smaller than the front end angle 0, in the first cutting process and an operation that makes the angle of the front end 02 of the second cutting part 123 less than the angle of the front end 02 in the first cutting process, and subsequently cutting the workpiece 5. In this way, the portion of the cut end face that is coated with the coating layer 5b can be increased and a good shape of the end face can be obtained. At this time, it is good to make the stroke S of the punch 120 gradually smaller in each cutting process. By adjusting the stroke to a large amount in the initial cutting process, the ability of the coating layer 5b to follow the movements of the first cutting part 113 and the second cutting part 123 increases. For example, among the plurality of cutting processes, the stroke S of the punch 120 in the first cutting process is preferably set to satisfy the relational expression of expression (1) mentioned above. More preferably, the stroke S of the punch 120 in the first cutting process is set to satisfy the aforementioned expression (2). It is noted that the phrase "the stroke S of the punch 120 in the first cutting process" refers to the amount of stroke when a position at which the blade contacts the workpiece 5 is taken as a starting point. By setting the stroke S of the punch 120 in the first cutting process in this way, the portion of the cut end face covered with the coating layer 5b can be increased and a good shape of the end face can be obtained. In addition, when the cutting of the workpiece 5 is carried out by performing a plurality of cutting processes, the leading end radius Ri of the first cutting part 113 and the leading end radius R2 of the second cutting part 113 Cutting size 123 can be made gradually smaller in the respective cutting processes. That is, in the second cutting process, at least one operation is performed among an operation that makes the leading end radius Ri of the first part of M A / t / ¿U¿ I / UOO I ¿ó cutting 113 is smaller than the leading end radius Ri in the first cutting process and an operation that makes the leading end radius R2 of the second cutting part 123 to be smaller than the front end radius R2 in the first cutting process; then, the workpiece 5 is cut. Also in this case, as in the case of reducing the angle of the leading end, an advantageous effect of increasing the portion covered by the coating layer 5b on the face of the workpiece is achieved. cut end and a good end face shape can be obtained. It should be mentioned that when it is desired to reduce the load on the cutting tool 100 while making the coating layer 5b cover the face of the cut end after having suppressed the formation of the cutting depressions during the cutting of the workpiece 5 , a configuration can be adopted to gradually increase the leading end angle θι of the first cutting part 113 and the leading end angle θ2 of the second cutting part 123 in the respective cutting processes. 2-2. Case where the closed region extracted from the workpiece will be used as a product (punching) Next, based on Fig. 19 to Fig. 21, a method for cutting a workpiece according to the second embodiment of the present invention will be described. Fig. 19 is a plan view illustrating cutting positions on the workpiece 5 in another cutting method, according to the present embodiment. Fig. 20 is an explanatory drawing illustrating a process for forming an intermediate material in the other cutting method according to the present embodiment. Figure 21 is an explanatory drawing illustrating a cutting process in the other cutting method, according to the present embodiment. While the cutting method according to the present embodiment is a method for cutting a closed region of the workpiece 5 from the workpiece 5 in a similar manner to the case of drilling as described above , a cutting method which is performed when the portion of the closed region removed from the workpiece 5 is to be used as a product, such as in the case of punching, will be described here. Similar to when drilling, as described above, it is sufficient for the closed region to have a shape represented by a curved line and, for example, the closed region may have a shape such as a circle or an ellipse. Similar to the case of making holes described above, the cutting method, according to the present embodiment, includes a process of forming an intermediate material from the workpiece 5 and a process of cutting the intermediate material to acquire a portion that will be used as a product. For example, in the case of cutting a closed circular region of the workpiece 5, illustrated in Figure 19, first of all, in the process of forming the intermediate material from ΜΛ / t / ZUZ I / UOO I Z of the workpiece 5, the workpiece 5 is cut at a cutting position P1 to form an intermediate material in which the part on the outer side of the position has been removed cutting position Pl. The cutting position Pl is set more on the outer side than a cutting position P2 in which the intermediate material is finally to be cut. Next, in the process of cutting the intermediate material, the intermediate material is cut at the cutting position P2 at which the intermediate material is desired to be finally cut. The intermediate material is cut using a cutting tool in which a wedge-shaped cutting part is provided on a die and a punch. Therefore, in the cutting method according to the present embodiment, when cutting an intermediate material using wedge-shaped cutting parts to create the shape of the final product, as illustrated in Figure 4, the cut end face of the workpiece 5 after cutting can be covered with the coating layer 5b. Therefore, the corrosion resistance of the cut end face can be improved while maintaining the corrosion resistance of the flat surface of the workpiece 5. In addition, before cutting the workpiece 5 in the position of cutting P2 in which you want to make the final cut, the closed region is cut to leave an excess region. In this way, by cutting the closed region at the cutting position P2, because a space for the material to move in can be ensured, the workpiece 5 can be cut reliably. Intermediate material formation process An example of the process of forming the intermediate material from the workpiece 5 is illustrated in Figure 20. In Figure 20, the workpiece 5 is cut at the cutting position Pl using a cutting tool 50 having a die 51 and a punch 52. The cutting tool 50 illustrated in Figure 20 has a configuration similar to the cutting tool 50 illustrated in Figure 14. The die 51 is a tubular member having a passage hole with a shape which corresponds to the closed region to be cut at the cutting position PL. The punch 52 is a member that is to be inserted through the die passage hole 51 and has a shape corresponding to the internal space of the die passage hole 51. By pushing down the punch 52 in a state where the workpiece 5 has been placed in the die 51, the closed region in the cutting position Pl is cut off from the workpiece 5. As a result, as illustrated on the lower side of Figure 20, the workpiece 5 is obtained. The obtained workpiece 5 is used as an intermediate material. The through hole in the intermediate material is formed on the outer side of the cutting position P2 in which the final cut is desired to be made. In the present embodiment also, the cutting position Pl is set on the opposite side of the final shape region, along the edge of the final shape region (i.e., the cutting position P2). In other words, in addition to the final shape region, the intermediate material also has, as an excess region, a portion between the cutting position P2 and the cutting position PL. The excess region is cut in the following process. By forming the intermediate material in this way, M A / I / UOO I ¿or when the intermediate material is cut at cutting position P2 in the next process, the material may move outward. It is worth mentioning that the method of forming an intermediate material from the workpiece 5 is not limited to the method using the cutting tool 50 illustrated in Figure 20 and can be carried out using laser cutting or another cutting method. Cutting process An example of the process for cutting the intermediate material is illustrated in Figure 21. The cutting tool 100 illustrated in Figure 21 has a similar configuration to the cutting tool 100 illustrated in Figure 15. That is, the cutting tool 100 to cut the intermediate material it has, as illustrated in Figure 21, a die 110 having a first wedge-shaped cutting part 113 on a base 111 and a punch 120 having a second wedge-shaped cutting part 123 on a base 121. The first cutting part 113 and the second wedge-shaped cutting part 123 are created in a closed shape corresponding to the cutting position P2. For example, in a case where the cutting position P2 is circular, as illustrated in Figure 21, the first cutting part 113 and the second wedge-shaped cutting part 123 are created in a circular shape. The workpiece 5 to be cut by the first cutting part 113 of the die 110 and the second cutting part 123 of the punch 120 is arranged between the die 110 and the punch 120. For example, the workpiece 5 is placed on the die 110. At that time, the die 110 and the punch 120 are installed so that the first cutting part 113 and the second cutting part 123 are facing each other. Then, in a state where the workpiece 5 has been placed on the die 110, the punch 120 is pushed down relatively with respect to the die 110, so that the workpiece 5 is cut in the cutting position P2. As illustrated on the bottom side of Figure 21, in the workpiece 5 that was cut by the cutting tool 100, the excess region has been removed and only the final shape region remains. As described in the first embodiment, in the cutting tool 100 when the punch 120 is pushed towards the die 110 by means of tensile forces arising between the first cutting part 113 and the second cutting part 123 and the workpiece work 5, a coating layer on the respective surfaces of the workpiece 5 is made to spread over the cut end face so that the cut end face is covered with the coating layer. That is, the coating layer on the respective surfaces of the workpiece 5 is made to follow the movements of the first cutting part 113 and the second cutting part 123 with respect to the workpiece 5, when the punch 120 it is pushed into the die 110 and the coating layer is caused to spread over the face of the cut end. Thus, the cut end face of the workpiece 5 can be coated with the coating layer. ΜΛ / t / ¿U¿ I / UOO I ¿ó It is noted that it is sufficient for the first cutting part 113 of the die 110 and the second cutting part 123 of the punch 120 to be configured to have shapes similar to the configuration of the first embodiment. Furthermore, cutting the intermediate material by the cutting tool 100 can also be carried out by performing the cutting once or performing the cutting a plurality of times. A method for cutting a workpiece according to the second embodiment of the present invention has been described above. It is worth mentioning that, although in the previous embodiment a cutting method is described in which a process is carried out to form an intermediate material from a workpiece and a process to cut the intermediate material to acquire a portion that will be used as product, the present invention is not limited to this example. For example, in a case where the intermediate material was not broken in the process of cutting the intermediate material, a process of cutting the excess region of the intermediate material may also be included. The process in question is carried out in order to completely separate the portion to be used as a product from the other portion and the method of carrying out the process is not particularly limited. For example, the excess region can be cut from the intermediate material using the cutting tool 50 illustrated in Figure 14 or Figure 20. Since the cutting tool used at this time is used to completely cut the excess region from the intermediate material, it is good to use a cutting tool that has a similar shape to the cutting tool used in the process of forming the intermediate material from the workpiece, but has a die diameter and a punch diameter different from that of the tool of cutting used in the process of forming the intermediate material. 3. Item cut 3-1. Schematic structure Next, based on Figure 22, the structure of a cut article 3 produced by cutting a workpiece using the cutting method according to the embodiment described above will be described. Figure 22 is an explanatory drawing schematically illustrating a cut end face 3a of the cut article 3, according to the present embodiment, and illustrating a state in which the cut end face 3a is viewed from the side. In the following description, a metal-coated steel sheet 5b is adopted as an example of a multi-layer material, in which the surface of a steel sheet 5a, which is a base material, is coated with a metal coating 5b, which is a coating material. The metal coated steel sheet 5 is, for example, a metal coated steel sheet defined in JIS G-3301, 3302,3314, 3321 or 3323 or the like. In addition, the sheet length direction of the metal coated steel sheet 5 is taken as the X direction, the sheet width direction is taken as the Y direction, and the sheet thickness direction is taken as the Z direction. In Figure 22, the cut article 3 formed by cutting the M A / t / ¿U¿ I / UOO I ¿or metal-coated steel sheet 5 in the sheet thickness direction (Z direction) and a state is shown in which the cut end face 3a is observed from the sheet width direction (Y direction). As illustrated in Figure 22, the cut end face 3a of the cut article 3 is composed of a first inclined face si, a second inclined face s2 and a fracture surface s5. The first inclined face si is composed of a cutting depression si 1 and an inclined portion si3. The second inclined face s2 is composed of a cutting depression s21 and an inclined portion s23. Shear depressions sil and s21 are deformations that occur due to tensile forces acting on the surfaces of the metal-coated steel sheet 5 when the metal-coated steel sheet 5 is cut. The inclined portions sl3 and s23 are faces that are continuous with the cutting depressions si 1 and s21 and that have a predetermined inclination angle with respect to the sheet thickness direction of the metal-coated steel sheet 5. At least a part of the first inclined face si and the second inclined face s2 is covered with the metal coating 5b that covers the surfaces of the steel sheet 5a. The fracture surface s5 is a face formed between the first inclined face si and the second inclined face s2. The fracture surface s5 is formed as a result of the breaking of the metal-coated steel sheet 5 in a manner in which the cracks generated in the metal-coated steel sheet 5 during cutting serve as starting points. Therefore, it is difficult for the fracture surface s5 to be covered with the metal coating 5b, which exposes the steel sheet 5a. As illustrated in Figure 22, viewed from the side, the cut end face 3a has a shape in which the fracture surface s5 protrudes more than the first inclined face si and the second inclined face s2. Furthermore, when the cut end face 3a is viewed from the side, the shape of the steel sheet 5a which is the base material of the first inclined face si and the second inclined face s2 has a substantially linear shape. Next, the structure of the cut article 3, according to the present embodiment, will be described in detail based on Figure 22 to Figure 24. Figure 23 is an explanatory drawing describing the shape of the cut article 3, according to the present modality. Figure 24 is an explanatory drawing illustrating another example of the shape of the cut article 3, according to the present embodiment. 3-2. Characteristics Lengths of inclined faces and relationship between lengths of both inclined faces The cut article 3 has the cut end face 3a which is composed of the first inclined face si, the second inclined face s2 and the fracture surface s5. Regarding the first face ΜΛ / t / ¿U¿ I / UOO I ¿ó inclined si and the second inclined face s2 of the cut end face 3a of the cut article 3, the thicknesses of the respective inclined faces si and s2 when the cut end face 3a viewed from the front (X direction) satisfy the following relational expression (3). The relational expression (3) represents that, with respect to the cut end face 3a of the cut article 3, according to the present embodiment, the sum of a thickness Ti of the first inclined face if when the cut end face 3a is observed from the front (i.e. the length of the first inclined face if in the direction of the sheet thickness (AicosOi)) and a thickness T2of the second inclined face s2 when the cut end face 3a is observed from the front ( that is, the length of the second inclined face s2 in the direction of the sheet thickness (A2cos02)) is less than the sheet thickness T of the metal-coated steel sheet 5. (T,+T2)<T ... (3) Ti = Aicos0i, T2= A2cos02 Ai: length of the first inclined face if when the face of the cut end 3a is observed from the side A2: length of the second inclined face s2 when the cut end face 3a is viewed from the side 0i: inclination angle of the first inclined face si 02: inclination angle of the second inclined face s2 T: sheet thickness of metallic coated steel sheet 5 Furthermore, in the cut article 3, the ratio (Ti / T2) between the thickness Ti of the first inclined face si of the cut end face 3a and the thickness T2 of the second inclined face s2 satisfy the following relational expression (4). The relational expression (4) expresses that, with respect to the cut end face 3a of the cut article 3, according to the present embodiment, the relationship between the thickness (Ti = Aicos0i) of the first inclined face si and the thickness ( T2= A2cos02) of the second inclined face s2 is 0.6 or more and 1.4 or less. This indicates that the difference between the shape of the first inclined face si and the shape of the second inclined face s2 is small, that is, the degree of symmetry of the cut end face 3a is high. The ratio (Ti / T2) between the thickness Ti of the first inclined face si and the thickness T2 of the second inclined face s2 is desirably 0.75 or more and 1.25 or less and more desirably is 0.85 or more and 1.15 or less. 0.6<(Ti / T2)<1.4 ... (4) By making the ratio (Ti / T2) satisfy this relational expression, a multilayer material can be obtained in which the degree of symmetry of the cut end face 3a is high. For example, at least a portion of the cut end face 3a is covered with coating materials that cover the respective surfaces of the base material that moves to follow the blades during cutting of the multi-layered material. At this time, in a case where the respective thicknesses of the coating materials covering the two surfaces of the base material are approximately equal, M A / t / ¿U¿ I / UOO I ¿or the greater the degree of symmetry of the cut end face 3a, the greater the degree of the thicknesses of the coating materials covering the cut end face 3a in the first inclined face si and the second inclined face s2, respectively, are the same. As a result, the corrosion resistance of the cut end face 3a can be stabilized. In this case, as illustrated in Figure 23, the term “length Ai of the first inclined face si” refers to the linear length of the end portion of the cutting depression sil on the surface side of the sheet of metal-coated steel 5 (hereinafter referred to as “initial inclination position Pi”) to the end portion on the side of the fracture surface s5 of the inclined portion s 13 (hereinafter referred to as “position end of inclination P2"). The term “length A2 of the second inclined face s2” refers to the linear length of the end portion of the shear depression s21 on the surface side of the metal-coated steel sheet 5 (hereinafter referred to as “ initial inclination position P3”) to the end portion of the fracture surface side s5 of the inclined portion s23 (hereinafter referred to as “final inclination position P4”). Furthermore, depending on the shape of the cutting tool 100, the cut end face 3a of the cut article 3 will have a shape in which, for example, as illustrated in Figure 24, the fracture surface s5 appears to have been torn. Also in this case, the first inclined face si and the second inclined face s2 are each composed of a cutting depression and an inclined portion. One of the inclined faces (in Figure 24, the first inclined face si) has approximately the same inclination as the fracture surface s5 and the other inclined face (in Figure 24, the second inclined face s2) has a shape that It tilts toward the fracture surface s5 and subsequently rotates upward. In this case, it is enough to define the thickness Ti of the first inclined face si and the thickness T2 of the second inclined face s2 as follows. Similar to Figure 23, the initial inclination position Pi of the first inclined face si and the initial inclination position P3 of the second inclined face s2 are end portions of the shear depressions on the sides of the surface of the metal-coated steel sheet 5. The length Ai of the first inclined face si is the linear length from the initial inclination position Pi of the inclined face s 1 to the final inclination position P2, which is the end portion of the inclined face if on the side of the fracture surface s5. The length A2 of the second inclined face s2 is the linear length from the initial inclination position P3 of the inclined face s2 to the final inclination position P4, which is the final portion of the inclined face s2 on the side of the fracture surface s5. At that time, if the inclined faces si and s2 are recessed and curved towards the side of the steel sheet 5a, the lengths can be determined by linear approximation. Furthermore, with respect to the upwardly rotating inclined face s2, as illustrated in Figure 24, the inclination between an end portion P5 of a portion where the metal coating 5b is present on the side of the fracture surface s5 and the initial position of M A / t / ZUZ I / UOO I Zó inclination P3can be approximated linearly and a point of intersection between the approximate straight line and an extension line in the horizontal direction passing through the final position of inclination P4, which is also the vertex of the upward turn, can be considered as the final inclination position P4 and can be taken as an end of the length A2 of the second inclined face s2. A thickness T3 of the fracture surface s5 is the distance between the final tilt position P2 and the final tilt position P4. An inclination angle θι of the first inclined face si is, as illustrated in Figure 23 and Figure 24, the inclination of the inclined portion si3 with respect to a straight reference line extending in the direction of the thickness of the sheet (Z direction). The angle formed by a straight line connecting the initial inclination position Pi and the final inclination position P2 and the reference straight line can be considered as the inclination angle 0,. Similarly, an inclination angle 02 of the second inclined face s2 is the inclination of the inclined portion s23 with respect to the straight reference line. The angle formed by a straight line connecting the initial tilt position P3 and the final tilt position P4 and the reference straight line can be considered as the tilt angle 02. As illustrated in Figure 23 and Figure 24, the T-sheet thickness of the metal-coated steel sheet 5 is represented by the sum of the T-sheet thickness of the steel sheet 5a and the thicknesses of the metal coating layer tay tb of the metal coating 5b formed on the surfaces of the steel sheet 5a. It is worth mentioning that, although an example is illustrated in Figure 22 to Figure 24 in which the thickness of the metal coating layer ta and the thickness of the metal coating layer tb are taken to be approximately the same, the present technique is not limited to this example and the thickness of the metal coating layer ta and the thickness of the metal coating layer tb may be different thicknesses from each other. Furthermore, in the cutting article 3, the thickness T3 of the fracture surface s5 when the cutting end face 3a is viewed from the front, satisfies the following relational expression (5). The relational expression (5) represents that, on the cut end face 3a of the cut article 3 according to the present embodiment, the length of the fracture surface s5, which is a ductile fracture surface in the final cutting stage, is 50% or less of the thickness of the sheet. It is worth mentioning that when the thickness T3 of the fracture surface s5 is 0, it means that the cut end face 3a is composed only of the inclined faces si and s2. Since the fracture surface s5 exists even in a state substantially close to 0 in the actual cut article, it is assumed that the thickness T3 of the fracture surface s5 of the cut article 3 is greater than 0. The thickness T3 of the article cut from the surface fracture rate s5 is desirably made 0.4 and more desirably made 0.3 or less. 0<T3<0.5T... (5) ΜΛ / I / UOO I ¿or By making the thickness T3 satisfy this relational expression, the inclined faces s 1 and s2 (i.e., the shear depression portions s 11 and s21 and the inclined portions s 13 and s23) increase and, as a result, the coverage improves. metallic coating. That is, in a case where sacrificial protection is applied to the base material, an advantageous effect of improving the corrosion resistance of the cut end face is exhibited. Furthermore, this shape can be obtained by adjusting the shape of the cutting edge or the position of the cutting tool. Metallic coating coating on inclined faces At least a portion of each of the first inclined face si and the second inclined face s2 is covered with metallic coating. More specifically, as illustrated in Figure 22, the first inclined face s 1 is coated with the metal coating 5b that covers the bottom surface (first surface) of the steel sheet 5a. The second inclined face s2 is coated with the metal coating 5b which covers the upper surface (second surface) of the steel sheet 5a. Therefore, the first inclined face s 1 and the second inclined face s2 are covered with the metal coating 5b continuing from a metal coating layer of the metal coated steel sheet 5, respectively. By the same metal coating 5b covering the regions from the respective surfaces of the steel sheet 5a to each inclined face in this way, oxidation of the steel sheet 5a on the cut end face 3a can be suppressed. For example, after cutting the metal coated steel sheet 5, by subjecting the cut end face 3a to a metal coating or paint treatment, it is possible to ensure that the steel sheet 5a is not exposed on the cut end face 3a. . However, it is difficult to cover the cut end face 3a with a material having the same composition as the metal coating 5b of the metal coated steel sheet 5, and the corrosion resistance of the cut end face 3a will be low in comparison with the surface corrosion resistance of steel sheet 5a. On the contrary, the cut end face 3a of the cut article 3, according to the present embodiment, is covered from each surface of the steel sheet 5a to the inclined faces si and s2 with the same continuous metal coating 5b. During cutting, while pushing against the steel sheet 5a, the relevant metal coating 5b moves towards the inclined faces si and s2 from the surfaces of the steel sheet 5a, following the movements of the cutting parts of the cutting tool. court. Therefore, compared with the case of performing surface treatment on the cut end face 3a after cutting, the adhesion between the steel sheet 5a and the metal coating 5b on the cut end face 3a is increased and can be improved. the corrosion resistance of the cut end face 3 a. Furthermore, the amount of metal coating 5b covering the first inclined face si and the second inclined face s2 decreases towards the center from the surfaces of the steel sheet 5a in the M A / I / UOO I ¿or direction of the thickness of the sheet (Z direction). That is, as illustrated in Fig. 22 and Fig. 23, in comparison with the thickness of the metallic coating layer of the metallic coating 5b covering the surfaces of the steel sheet 5a, on the first inclined face s 1 and the second inclined face s2 the thickness of the metal coating layer gradually decreases towards the center in the direction of the width of the sheet from the surfaces. The metallic coating 5b that covers the first inclined face si and the second inclined face s2 is a metallic coating that covers the first inclined face si and the second inclined face s2 as a result of the movement of the metallic coating 5b of the metallic coating layers constituting the metal coated steel sheet 5. Therefore, if the thickness of the metal coating layer of the metal coating 5b on the first inclined face s 1 and the second inclined face s2 becomes large, although the corrosion resistance will increase of the cut end face 3a, there is a possibility that the corrosion resistance of the flat surface will decrease since the thickness of the metal coating layer of the metal coating 5b on the surfaces of the steel sheet 5a will be smaller. Consequently, by the metal coating 5b being covered on the first inclined face s 1 and the second inclined face s2 so that the amount of the metallic coating 5b covering the inclined faces decreases from the surfaces of the steel sheet 5a towards the center, along with maintaining the corrosion resistance of the flat surface of the cut article 3, the corrosion resistance of the cut end face 3a can also be increased. As illustrated in Fig. 22 to Fig. 24, the shape of the steel sheet 5a which is the base material of the first sloping face s 1 and the second sloping face s2 can be created to have an approximately linear shape when the cut end face 3a is seen from the side. For example, if the shape of the cut end face 3a of the steel sheet 5a is assumed to be an arc shape viewed from the side, the surface area of ​​the end face of the steel sheet 5a will be large. in comparison with a case where, as illustrated in Fig. 22 to Fig. 24, the steel sheet 5a of the first sloped face si and the second sloped face s2 have an approximately linear shape. In such a case, it will be necessary to cause a larger amount of the metal coating 5b of the metal coating layer to move from the surface side to the cut end face 3a to cover the cut end face 3a. Therefore, as illustrated in Fig. 22 to Fig. 24, by adopting a configuration so that the shape of the steel sheet 5a which is the base material of the first inclined face si and the second inclined face s2 has a shape approximately linear when the end face of the cut 3a is viewed from the side, the occurrence of a defect such as cracking of the coating in the outer layer or localized thinning can be suppressed. Furthermore, with respect to the first inclined face si and the second inclined face s2, it is not necessarily required that all the inclined faces be covered with the metallic coating 5b and it is sufficient that at least a part of the inclined faces be covered with the metallic coating 5b. Yeah M A / I / UOO I ¿or a portion of the inclined faces si and s2 are covered, the progress of corrosion will be suppressed by a sacrificial protection effect with respect to the portions that are not also covered with the metallic coating 5b. In order to exert a sacrificial protection effect on the inclined faces si and s2 and the fracture surface s5, a metal coating coverage X of the inclined faces si and s2 is preferably 20% or more. Here, the metallic coating coverage observed from the side (i.e., the sheet width direction (Y direction)) and is represented by the following expression (6). It is observed that, in the following expression (6), A is the sum of the length A of the first inclined face si and the length A2 of the second inclined face s2 (that is, Ai+A2). Furthermore, B is the sum of the length B, of a portion in which the metallic coating 5b is present on the first inclined face si and the length B2 of a portion in which the metallic coating 5b is present on the second inclined face s2 (ie Bi+B2). X = 100 x (B / A) ... (6) A (= Ai+A2): length of inclined faces B (= Bi+B2): length of the portions in which the metallic coating is present The respective lengths Bi and B2 of the portions in which the coating 5b is present are taken as the respective lengths from the initial inclination positions Pi and P3 to the respective positions in which the thickness of the metal coating layer of the metal coating 5b in the inclined faces si and s2 become 5% of the metal coating layer thicknesses ta and tb of the metal coated steel sheet 5 before cutting. This is because, when taking into account the long-term use of the material that undergoes metal plating treatment for corrosion resistance, the cut end face 3a must also have the same degree of corrosion resistance. than the surface of the metal coated steel sheet 5. When taking into account the extension of a metal coating component that was cast from the metal coated steel sheet 5 to the cut end face, it is considered that if approximately 5% of the metallic coating remains on the cut end face 3a, it will be exhibited as the initial corrosion resistance. Furthermore, it is enough to set a coefficient to identify a position where the metal coating 5b remains according to the sheet thickness t of the steel sheet 5a. If the sheet thickness t of the steel sheet 5a is a small value, the coefficient may be small. It is noted that it is sufficient for the sheet thickness t of the steel sheet 5a to be a sheet thickness with which it is possible to produce the cut article 3 and, for example, it may be the sheet thickness t set in 0.2 mm or more and 10 mm or less. M A / I / UOO I ¿or Furthermore, in a case where the cut article 3 has the cut end face 3a having a shape as illustrated in Fig. 24, with respect to the inclined face s2 which is turned upward, although the metal coating 5b is substantially absent at a location located further forward on the side of the cutting depression than the final tilt position P4, which is also the apex of the upward swing, in some cases the metal coating left on the leading end of the tool adheres to the area in the vicinity of the final tilt position P4. Since the adhesion of the coating in the vicinity of the final tilt position P4 is an uncertain element, even if the thickness of the coating layer in the vicinity of the final tilt position P4 is approximately 5% or more of the layer thicknesses of coating ta and tb of the metallic coated steel sheet 5 before cutting, it is better not to consider the vicinity of the final tilt position P4 as part of the length B2 of the portion in which the metallic coating 5b is present. Therefore, according to the present embodiment, by making the shape of the cut end face of the metal-coated steel sheet 5 have the shape described above, the corrosion resistance of the cut end face can be improved. while maintaining the corrosion resistance of the flat surface by means of the metal coating 5b which is a multi-layer material on the metal coating steel sheet 5. Method for observing the cut end face It is possible to identify the shape of the cut article 3 by looking at the face of the cut end 3a. The thickness Ti of the first inclined face si and the thickness T2 of the second inclined face s2 when viewing the cut end face 3a from the front are measured by embedding the cut article 3 in a resin or the like and polishing to prepare a sample and , subsequently, observing the sample from the side. That is, the sample is observed from the Y direction (sheet width direction), as illustrated in Figure 22. The observation is performed using, for example, a stereo microscope or a scanning electron microscope (SEM). acronym in English). Specifically, for example, it is sufficient to divide the sample equally in the width direction by the number of measurements and perform the measurement in each of the cross sections. It is good to measure at least three locations. It is enough to take the average value of the thickness of the first inclined face if in the respective cross sections as the thickness T । of the first inclined face s 1 and take the average value of the thickness of the second inclined face s2 in the respective cross sections as the thickness T2 of the second inclined face s2. When observing the coverage of a coating material on a cut end face, there are cases where, depending on the type of coating material, a material of ΜΛ / t / ZUZ I / UOO I ¿or coverage that is less than the actual coverage. Therefore, for example, when preparing a sample, it is desirable to embed a portion around the coating material in a resin or the like in a state where it is reinforced by a backing plate, and subsequently perform polishing. Furthermore, it is desirable to use a polishing method in accordance with the class or hardness of the coating material. As another method of observing the cut end face 3a of the cut article 3 that is different from the method that observes a sample prepared by embedding the cut article 3 in a resin or the like, for example, a method that observes the end face can be used of section 3a from the front using a stereomicroscope or SEM-EDS (energy dispersive X-ray spectroscopy). In the case where it is possible to determine the presence of the coating material by means of color or gloss, it is sufficient to determine the coating material of the cut end face 3a using a stereoscopic microscope. On the other hand, when it is difficult to confirm the presence of the coating material based on color or gloss, it is sufficient to determine the presence of the coating material using a SEM (BSE image) or EDS (all acronyms) backscatter electron image. in English). Since the locations on the cut end face 3a where the coating material is actually present can be estimated based on these methods, it can be confirmed whether or not polishing has been performed as intended. It is worth mentioning that in the case where it is difficult to polish the sample, the thickness Ti of the first inclined face si and the thickness T2 of the second inclined face s2 can be identified by observing the cut article 3 from the front (that is, from the X direction). and measuring the length of the portions in which the coating material is present on the cut end face 3a. At that time, the length of a portion in which the coating material is present can be measured at a plurality of locations in the width direction of the cut end face sheet 3a and the average length of the measured lengths is can be adopted as the thickness of the inclined face. It is observed that, with respect to the cut article 3 according to the present embodiment, whenever there is a variation with respect to the sum of the thickness Ti of the first inclined face s 1 and the thickness T2 of the second inclined face s2 as well as in the value of a ratio between them is 30% or less in a range of 60% or more of the sheet width of the multilayer material, it is possible to improve the corrosion resistance of the cut end face while maintaining the strength to corrosion of the flat surface of the multi-layer cut end face material 3a. At that time, it is sufficient that, in the range of 60% or more of the width of the sheet of the multi-layer material, a variation in the coverage of the coating material when the cut end face 3a is viewed from the side is of 30% or less. With respect to a variation in coverage, similar to when measuring coverage, as described above, it is sufficient to measure the ΜΛ / t / ¿U¿ I / UOO I ¿o portions that are coated with the coating material at a plurality of locations in the width direction of the sheet using a stereomicroscope or SEM-EDS and calculate the average value of these measured values ​​and subsequently calculate a variation of the average value. The structure of the cut article 3 produced by cutting a workpiece using the cutting method, according to the present embodiment, has been described above. It is worth mentioning that, although the cut article described in the previous embodiment has a shape that is vertically symmetrical with respect to the center in the direction of the thickness of the sheet, the present invention is not limited to this example and the cut article may have a shape make it a vertically asymmetric shape. For example, the length Ai of the first inclined face if can be shorter than the length A2 of the second inclined face s2. Furthermore, the inclination angles θι and 02 do not necessarily need to be the same. EXAMPLES A. Coverage status of metal coating of cut end face A metal-coated metal material was adopted as a workpiece that had been subjected to surface treatment, and the coverage state of the metal coating on one face of the cut end of the metal-coated metal material was observed when the metal-coated metal material was cut with cutting tools. Front photographs and lateral cross-sectional photographs of the respective cut end faces of the metal-coated metal material that was cut with the cutting tools are shown in Figure 25. In Figure 25, as a comparative example, a front photograph and a side cross-sectional photograph of the cut end face of a metal-coated metal material are shown when the metal-coated metal material was cut using the conventional cutting tool. 10 illustrated in Figure 35. In addition, in Figure 25, as in examples Al and A2, front photographs and photographs of a side cross section of the cut end face of a metallic material with metallic coating are shown when the metallic material with metal coating was cut using the cutting tool 100 of the present invention illustrated in Figure 1. In example Al, the leading end radius Ri of the cutting edge of the die and the leading end radius R2 of the cutting edge of the punch were each one of 0.05 mm. In example A2, the leading end radius R of the cutting edge of the die and the leading end radius R2 of the cutting edge of the punch were each 0.5 mm. Furthermore, with respect to the metal coated metal material used in the comparative example and examples Al and A2 shown in Figure 25, a ratio of a portion coated with the metal coating to the thickness of the sheet of the coated metal material M A / t / ¿U¿ I / UOO I ¿o metallic of the cut end face (hereinafter referred to as “sheet thickness ratio”) is shown in Figure 26. The sheet thickness ratio is represented by the length in the thickness direction of the sheet when the cut end face of the metallic coated metal material is viewed in plan view. In Figure 26, with respect to a frontal field of view of each cut end face shown in Figure 25, a sheet thickness ratio of the area of ​​a portion of which 50% or more is coated with the coating metal that appears in white in the corresponding image (hereinafter "portion coated with 50% metallic coating") to the total area of ​​the cut end face and a sheet thickness ratio of the area of ​​a portion of which 1% or more is coated with the metallic coating (i.e., the area ratio of the places where the metallic coating covers the metallic material even a little is shown (hereinafter referred to as “portion coated with 1% of metallic coating”) with respect to the total area of ​​the face of the cut end. Specifically, as illustrated in Figure 27, for the comparative example, the thickness of the sheet of the metallic material with metallic coating is taken as t, the thickness of the sheet of the portion coated with 50% metallic coating is taken as ti and the thickness of the sheet of metallic material with 1% metallic coating is taken as t2. In examples Al and A2 the thickness of the sheet of the metallic material with metallic coating is taken as with 1% metallic coating are taken as t2 and 12'. That is, for the comparative example the sheet thickness ratio of the portion coated with 50% metallic coating was calculated by ti / to and the sheet thickness ratio of the portion coated with 1% metallic coating was calculated by t2 / to- In addition, in examples Al and A2, the thickness ratio of the sheet of the portion covered with 50% metallic coating was calculated by (ti+ti') / to and the thickness ratio of the sheet of the portion covered with 1% metallic coating by (t2+t2') / to. As illustrated in Figure 25, in the comparative example, the cut end face was formed by a cutting depression, a cutting surface and a fracture surface and the proportion of the fracture surface was large. Although there was a large amount of metal coating in the cutting depression, there was almost no metal coating on the cutting surface and fracture surface. Figure 26 shows that, in the comparative example, the sheet thickness ratio of the portion coated with 50% coating was approximately 15% and the sheet thickness ratio of the portion coated with 1% metal coating It was approximately 28%. The cutting surface is formed when the cutting edge of the tool enters the metal material and the metal coating and the fracture surface is formed as a result of the propagation of a crack. M A / I / UOO I ¿or ductile fracture. Therefore, it is considered that in the case where the conventional cutting tool was used, the metal coating could not follow the tool to the cutting surface and the fracture surface and therefore there was almost no metal coating present. in the same. On the other hand, with respect to example Al and example A2, although the radii of the leading ends Ri and R2 of the cutting edges differed, each face of the cut end was formed by cutting depressions, inclined faces and a fracture surface and the proportion of inclined faces was large. The metallic coating remained on each inclined face and the amount of metallic coating on each inclined face decreased toward the center of the sheet thickness from the surface of the metallic material. Furthermore, compared with example Al, in example A2 in which the front end radii Ri and R2 of the cutting edges were larger, the rate of decrease in the amount of metal coating until the proximity of the center of the thickness of the sheeting from the surface of the metal material on the inclined faces was small and a greater amount of metal coating followed the movement of the cutting edges. Figure 26 shows that in example Al the sheet thickness ratio of the portion coated with 50% metallic coating was approximately 55% and the sheet thickness ratio of the portion coated with 1% metallic coating was approximately 78%. and that in Example A2 the sheet thickness ratio of the portion coated with 50% metallic coating was approximately 71% and the sheet thickness ratio of the portion coated with 1% metallic coating was approximately 76%. These results indicate that by cutting a metallic material with metallic coating using the cutting tool 100 of the present invention, it is possible to extensively cover the cut end face with the metallic coating. B. Angle of the leading end of the cutting edge The damage state of the cutting edges as well as the shape of the cut end face of the relevant workpiece were investigated when illustrating the leading end angle θι of the first cutting part and the leading end angle 02 of The second cutting part of the cutting tool in Figure 1 was changed and the cutting tool was used to cut a workpiece. A galvanized steel sheet having a sheet thickness of 3.2 mm and a tensile strength of 460 MPa was used as the workpiece. Regarding the cutting process of the workpiece, the angles of the front ends Oí and 02 of the cutting edges were changed and the cutting process was performed twice with each cutting edge. It is worth mentioning that the front end radii Ri and R2 of the cutting edges were each set at 0.05 mm. The results are shown in table 1. It is observed that the term “protruding portion” with respect to the evaluation of the shape of the end face M A / I / UOO I ¿ó cut means a portion projecting from the face of the cut end that arises on the face of the cut end during cutting. MA / t / ¿U¿ I / UOO I ¿ó Table 1 Angle of the front end Θ1=θ2 [°] State of coverage of the metallic coating Damage of the cutting edge Shape of the face of the cutting end 5 CC EE AA 10 cc CC AA 30 CC BB AA 40 BB BB AA 60 AA AA AA 90 AA AA BA 120 AA AA EA 150 AA AA EE Evaluation criteria for the coverage status of the metallic coating A: The sheet thickness ratio of a portion coated with 1% metal coating or more is 70% or more B: The sheet thickness ratio of a portion coated with 1% metal coating or more is 60% or more C: The sheet thickness ratio of a portion coated with 1% metallic coating or more is 50% or more D: The sheet thickness ratio of a portion coated with 1% metal coating or more is 40% or more E: The sheet thickness ratio of a portion coated with 1% metallic coating or more is less than 40% Cutting Edge Damage Evaluation Criteria A: No damage B: Small defects present on the surface C: There is a slight plastic deformation D: There is slight plastic deformation present in a length of 100 pm or more E: There is plastic deformation Cut End Face Shape Evaluation Criteria A: very good B: good C: There is a slightly protruding portion D: A slightly protruding portion is present in several places E: There is a protruding portion As illustrated in Table 1, in the case of each of the leading end angles of the cutting edges, the ratio of the sheet thickness of the portion coated with 1% metal coating or more on the end face cut from the workpiece was 50% or more. In a case where the angle of the leading end of the cutting edge was 5o, although the cutting edge was plastically deformed, the cut end face of the workpiece was good and cutting was also easy. When the leading end angle of the cutting edge was made equal to 10°, the plastic deformation of the cutting edges decreased to an allowable level as compared with the case where the leading end angle of the cutting edge was 5°. When the angle of the leading end of the cutting edge was further increased, although the cutting edge was not plastically deformed when the angle of the leading end was 30° to 40°, there were small defects on the surface of the cutting edge, and in particular, when the leading end angle was 60° to 90°, the cutting edge was not plastically deformed and there was no damage to the cutting edge and the cut end face was also good. It is observed that, by increasing the angle of the leading end of the cutting edge, the damage to the cutting edge was suppressed, when the angle of the leading end of the cutting edge was 120° or more, a protruding part arose on the face of the cut end of the blade. workpiece and although the load required to cut increased, the cut end face of the workpiece was sufficiently covered with the metal coating. Cases where the cut end face shape evaluation was E included some cases where breakage did not occur in the workpiece and the cut was not completed. Based on the above results, it was shown that the metallic coating was sufficiently applied to the cut end face of the workpiece, regardless of the angle of the leading end of the cutting edge. In addition, it was shown that, from the point of view of suppressing tool damage, cut end face shape of the workpiece, and ease of cutting, it is preferable to make the leading end angles θι and Θ2 of the cut portions 10° or more and 120° or less, and more preferably, making the leading end angles θι and 62 of the cut portions 30° or more and 90° or less. C. Radius of leading end of cutting edge The damage state of the cutting edges was investigated, as well as the shape of the cut end face of the relevant workpiece when the leading end radius Ri of the first cutting part and the leading end radius R2 of the second cutting part of the cutting tool illustrated in Fig. 1 were changed and the cutting tool was used to cut a workpiece. A galvanized steel sheet having a sheet thickness of 3.2 was used as the workpiece. M A / I / UOO I ¿ó mm and a tensile strength of 460 MPa. Regarding the cutting process of the workpiece, the leading end angles θι and 02 of the cutting edges were both made 60° and the leading end radii Ri and R2 of the cutting edges were changed and the process Cutting was performed twice with each cutting edge. Results are shown in table 2. MA / I / UOO I Table 2 Front end radius Ri = R2 [mm] Front end radius / sheet thickness [%] State of metal coating coverage Damage of cutting edge End face shape 0.01 0.3 DD EE AA 0.02 0.6 CC CC AA 0.05 1.6 BB BB AA 0.1 3.1 AA AA AA 0.3 9.4 AA AA AA 0.4 12.5 AA AA BB 0.5 15.6 AA AA CC 1.1 34.4 AA AA DD 1.6 50.0 AA AA EE Criteria for evaluating the coverage status of the metallic coating) A: The sheet thickness ratio of a portion coated with 1% metal coating or more is 70% or more B: The sheet thickness ratio of a portion coated with 1% metal coating or more is 60% or more C: The sheet thickness ratio of a portion coated with 1% metallic coating or more is 50% or more D: The sheet thickness ratio of a portion coated with 1% metal coating or more is 40% or more E: The sheet thickness ratio of a portion coated with 1% metallic coating or more is less than 40% Cutting Edge Damage Evaluation Criteria A: no damage B: Small defects present on the surface C: There is a slight plastic deformation D: There is slight plastic deformation present in a length of 100 pm or more E: There is plastic deformation Cut End Face Shape Evaluation Criteria A: very good B: good C: There is a slightly protruding portion D: A slightly protruding portion is present in several places E: There is a protruding portion As illustrated in Table 2, in the case of each of the radii of the leading ends of the cutting edges, the sheet thickness ratio of the portion coated with 1% metallic coating or more on the end face cut from the workpiece was 40% or more. In cases where the ratio of the leading end radius to the sheet thickness was 3.1% or more, the sheet thickness ratio of the portion coated with 1% or more metallic coating was 70% or more. In the case where the front end radii Ri and R2 of the cutting edges were 0.01 mm, that is, in the case where the ratio between the front end radius and the thickness of the sheet was 0.3%, although the cutting edges were plastically deformed, the cut end face of the workpiece was good and cutting was also easy. In the case where the front end radii Ri and R2 of the cutting edges was 0.02 mm, that is, in the case where the ratio between the front end radius and the thickness of the sheet became 0.6%, the plastic deformation of The cutting edges decreased to a permissible level and the cut end face was also good. When the radii of the leading ends Ri and R2of the cutting edges increased further, when the radii of the leading ends Ri and R2were from 0.05 mm to 0.3 mm, that is, in cases where the ratio of the radius of the leading end to the Sheet thickness was 1.6% to 9.4%, the cutting edges were not plastically deformed, and almost no damage was observed on the cutting edges. Also, the cut end face was good too. It is worth mentioning that when the front end radii Ri and R2 of the cutting edges were made large, the damage to the cutting edges was suppressed. On the other hand, when the radii of the front ends R, and R2 of the cutting edges were 1.6 mm, that is, in the case where the ratio between the radius of the front end and the thickness of the sheet was 50.0%, although a protruding portion on the cut end face of the workpiece, the cut end face of the workpiece was sufficiently covered with the metal coating. Furthermore, when the ratio of the leading end radius to the sheet thickness was 34.4% or less, the deterioration of the shape of the end face due to the presence of a protruding portion was suppressed. Based on the above results, it was shown that the metal coating was sufficiently applied to the cut end face of the workpiece, regardless of the size of the radii of the leading ends of the cutting edges (the ratio of the end radius front and the thickness of the sheet). In addition, it was shown that from the point of view of suppressing damage to the tool, the shape of the cut end face of the workpiece and the ease of cutting it is preferable to make the ratio of the front end radii Ri and R2of the cutting parts with the thickness of the ΜΛ / t / ZUZ I / UOO I Zó sheet equal to 0.5% or more and 35.0% or less and, more preferably, make the ratio of the radii of the front ends Ri and R2of the cutting parts with the thickness of the sheet is equal to 1.5% or more and 10.0% or less. M A / t / ¿U¿ I / UOO I ¿ó D. Relationship between tensile strength of workpiece and cutting state Galvanized steel sheets with tensile strengths of 270 MPa, 460 MPa, 585 MPa and 1020 MPa were adopted as workpieces and the cutting state was investigated when the workpieces were cut using the cutting tool of the present invention. illustrated in Figure 1. The sheet thickness of each workpiece was 3.2 mm. It is worth mentioning that the galvanized steel sheet having a tensile strength of 460 MPa was a separate material from the steel sheet used in the aforementioned example C. Cutting of the workpieces was carried out by making each of the leading end angles θι and θ2of the cutting edges 60° and changing the radii of the leading ends Ri and R2of the cutting edges and performing cutting twice with each cutting edge. The results are shown in table 3. Table 3 Tensile strength [MPa] 270 460 585 1020 Ri=R2=0.02 mm (sheet thickness ratio 0.6%) AA AA AA AA Ri=R2=0.1 mm (sheet thickness ratio 3.1%) AA AA AA AA Ri=R2=0.5 mm (sheet thickness ratio 15.6%) AC BC AC AC Ri=R2=1.05 mm (sheet thickness ratio 32.8%) CC CC CC CC Ri=R2=1.1 mm (sheet thickness ratio sheet thickness 34.4%) CD CC CC CC Ri=R2= 1.6 mm (sheet thickness ratio 50.0%) EE EE EE EC Cut End Face Shape Evaluation Criteria A: Very good B: Good C: There is a slightly protruding portion D: A slightly protruding portion is present in several places E: There is a protruding portion The test results showed that the ratio of sheet thicknesses of a portion coated with 1% metal coating or more was 50% or more on the cut end face of the workpieces having the respective tensile strengths. Furthermore, based on Table 3, it was found that with respect to galvanized steel sheets having a tensile strength of 270 MPa or more, in a case where the front end radii Ri and R2 of the cutting edges were 0.5 mm or less, cutting was possible and a good cut end face could be obtained. Furthermore, with respect to galvanized steel sheets having a tensile strength of 270 MPa or more, it was possible to perform cutting even when the front end radii Ri and R2 of the cutting edges were greater than 0.5 mm. E. Shape of upper and lower cutting parts With respect to the cutting tool illustrated in Figure 1, the shapes of the cut end faces of the workpieces were investigated when the workpieces were cut using the first cutting part and the second cutting part in the that the front end radius Ri and the front end radius R2 were different from each other. Similar to the verification in section “A”, which was described above, a metal material with metal coating was adopted as a workpiece that had been subjected to surface treatment, and the coverage state of the metal coating was observed on a cut end face of the metal-coated metal material when the metal-coated metal material was cut by cutting tools. Front photographs and lateral cross-sectional photographs of the respective cut end faces of the metal-coated metal material that was cut with the cutting tools are shown in Figure 28. In example El, the leading end radius Ri of the cutting edge of the die was 0.5 mm, the leading end radius R2 of the cutting edge of the punch was 0.05 mm, and the leading end radius ratio Ri / R2 was 10. In Example E2, the leading end radius Ri of the die cutting edge was 0.05 mm, the leading end radius R2 of the punch cutting edge was 0.5 mm, and the leading end radius ratio R1 / R2 was 0.1. Furthermore, in Figure 28, the cut end face of a metallic coated metal material obtained when the front end radii Ri and R2 were both 0.05 mm is shown as Reference Example 1 and the cut end face of a Metallic coated metal material obtained when the front end radii Ri and R2 were both made 0.5 mm is shown as reference example 2. As illustrated in Figure 28, on the respective faces of the cut ends of the metal-coated metallic materials of Examples El and E2, although the shapes as seen in M A / t / ¿U¿ I / UOO I ¿ó side view were different on the left and right as compared to the respective cut end faces of the metal-coated metal materials of Reference Examples 1 and 2, Shear depressions, inclined faces, and a fracture surface had formed. In addition, although the fracture surface ratio of each of Examples El and E2 was higher compared to Reference Examples 1 and 2, the sheet thickness ratio of the portions coated with 1% metal coating or more had remained at 50% or more. Therefore, even in the case where the leading end radii Ri and R2 of the upper and lower cutting portions differ from each other, when cutting a metal-coated metal material using the cutting tool 100 of the present invention, it is possible to extensively cover the cut end face with metallic coating. It is worth mentioning that, although a case was verified here where the leading end radii Ri and R2 of the upper and lower cutting parts were different, in one case where the leading end angles θι and θ2 of the upper and lower cutting parts may be different from each other as well, when cutting a metallic coated material using the cutting tool 100 of the present invention, the cut end face can be extensively covered with metallic coating. F. Cutting through a plurality of cutting processes The shape of a face of the cut end of a workpiece was investigated when the workpiece was cut by performing a cutting process twice with the cutting tool illustrated in Fig. 1. Similar to the verification in the section “ A", which was described above, a metal-coated metal material was adopted as the workpiece which had been subjected to a surface treatment, and the covering state of the metal coating was observed on a face of the cut end of the metal-coated metal material when the metal coated metal material was cut with a cutting tool. Frontal photographs and photographs of a side cross section of the respective faces of the cut ends of the metal-coated metal material which was cut with the cutting tool are shown in Fig. 29 . In example Fl, in a first cutting process, the metal coated metal material was cut to a partial position using a die and a punch in which the front end radii Ri and R2 of the cutting edges were 0.05 mm and In a second cutting process, the metal coated metal material was completely cut using a die and punch in which the front end radii Ri and R2 of the cutting edges were 0.5 mm. In example F2, in a first cutting process, the metal coated metal material was cut to a partial position using a die and a punch in which the front end radii Ri and R2 of the cutting edges were 0.5 mm and In a second cutting process, the metal coated metal material was completely cut using a die and punch in which the front end radii Ri ΜΛ / t / ¿U¿ I / UOO I ¿ó and R2 of the cutting edges were 0.05 mm. Furthermore, reference examples 1 and 2 which are the same as those in Figure 28 are also shown in Figure 29. As illustrated in Figure 29, the cut end faces of the metal-coated metal materials of Examples F1 and F2 were each formed of cutting depressions, inclined faces and a fracture surface and the ratio of the slanted faces was big. The metallic coating remained on each inclined face and the amount of metallic coating on each inclined face decreased toward the center of the sheet thickness from the surface of the metallic material. Furthermore, by comparing the cut end faces of the metal-coated metal materials of Examples F1 and F2 with the cut end faces of the metal-coated metal materials of Reference Examples 1 and 2, it was found that the faces of the cut ends of examples F1 and F2 were influenced by the radii of the leading ends Ri and R2 of the cutting edges of the cutting tool used in the second cutting process. For example, although a protruding portion was formed as on the cut end face of Reference Example 2 on the cut end face of Example Fl, a greater amount of metallic coating was observed to remain on the cut start point portion. than in other portions of the cut end face. Furthermore, the cut end face of Example F2 was close to Reference Example 1, had a good end face shape with few burrs, and the ability of the metal coating to follow the movements of the cutting edges was good. Thus, when cutting a metallic material with metallic coating using the cutting tool 100 of the present invention by performing a plurality of cutting processes, it is possible to extensively cover the cut end face with metallic coating. In particular, it was found that by making the front end radii Ri and R2 of the cutting parts in the second cutting process smaller than the front end radii Ri and R2 of the cutting parts in the first cutting process, a portion coated with the metal coating on the cut end face can be enlarged and a good shape of the end face can be obtained. In addition, it was also found that by making the leading end angles θι and 02 of the cutting parts in the second cutting process smaller than the leading end angles θι and Θ2 of the cutting parts in the first cutting process, a portion coated with the metal coating on the cut end face can be enlarged and a good shape of the end face can be obtained. Furthermore, with respect to a case where cutting is performed a plurality of times, the fracture surface ratio was investigated when the leading end angles or leading end radii of the cutting edges were reduced during cutting. A galvanized steel sheet having a sheet thickness of 3.2 mm and a tensile strength of 460 MPa was used as the workpiece, similar to the galvanized steel sheet described above. The ΜΛ / t / ¿U¿ I / UOO I ¿ó results are shown in table 4. It is worth mentioning that the front end radii Ri and R2 were made equal (R = Ri = R2) and the front end angles 0i and 02 also became the same (0 = 01 = 02). Table 4 M A / I / UOO I ¿or No. R of the first cutting process [mm] R of the second cutting process R [mm] 0 of the first cutting process [°] 0 of the second cutting process [°] Fracture surface ratio [%] 1 0.05 0.05 60 60 0.21 2 0.5 0.5 0.25 3 0.05 0.5 0.29 4 0.5 0.05 0.17 5 0.05 0.05 45 45 0.25 6 60 60 0.21 7 45 60 0.25 8 60 45 0.20 In Nos. 1 to 4 of Table 4, the front end angle 0 was kept constant and the front end radius R was changed. As a result, it was found that by making the front end radius R at the time of the second cutting process smaller than the front end radius R at the time of the first cutting process as in the case of No. 4, The fracture surface ratio decreases and the interval covered with the metallic coating increases. Furthermore, in Nos. 5 to 8 of Table 4, the front end radius R was kept constant and the front end angle 0 was changed. As a result, it was found that by making the front end angle 0 at the time of the second cutting process smaller than the front end angle 0 at the time of the first cutting process as in the case of No. 8, the ratio of the fracture surface decreases and the interval covered with the metallic coating increases. G. Cut with cutting tool with asymmetrical cutting edges A metal-coated metal material was adopted as the workpiece that had been subjected to surface treatment, and the shape of the cut end face of the metal-coated metal material was observed when the metal-coated metal material was cut with cutting tools. . In example Gl, the metallic material with metallic coating was cut using a die and a punch, each with a cutting part in which the left and right angles were different from each other, as illustrated in Figure 10 The die and punch were of the same shape and were arranged symmetrically with respect to the metal-coated metal material. The leading end angles θι and 02 of the respective cutting edges were 75° and the leading end angle was formed in a shape that was divided into two parts to form angles of 45° (= 0ia= 02a) and 30° ( = 0ib = 02b) along the normal line. In example G2, the metal coated metal material was cut using a die and a punch, each with a cutting portion in which the radii of the left and right front ends were different from each other, as illustrated in Figure 11. The die and punch were of the same shape and were arranged symmetrically with respect to the metal-coated metal material. The radii of the leading ends of the cutting edges of the die and punch were 0.5 mm (= Ria= R2a) on one side and 0.05 mm (= Rib = R2b) on the other side with respect to the normal line, respectively. . It is worth mentioning that, as a reference example, the metal coated metal material was cut with a cutting tool having a shape in which the cutting parts had left to right symmetry with respect to the normal line. The die and punch were of the same shape and were arranged symmetrically with respect to the metal-coated metal material. The leading end angles 0i and 02 of the cutting edges were each 60° and the left and right angles formed when the leading end angle was bisected by the normal line were each 30°. ° (= 0ia= 02a= 0ib = 02b)The shape of the cut end face of each metal-coated metal material when the metal-coated metal material was cut by the cutting method of examples G1 and G2 and example Reference are illustrated in Figure 30. Figure 30 schematically illustrates the shape when viewed in a side view with respect to, of all the metallic coated metal material that was cut, a cut end face on a side that was cut that is on the side on which the angle or radius of the front end was greater when the cutting part was divided into two parts by the normal line. It is worth mentioning that, with respect to the reference example drawing, since each of the cut end faces of the metallic coated metal material that was cut had the same shape, the shape of the cut end face of a piece of it. Furthermore, in the reference example and examples G1 and G2 it was confirmed that a metallic coating layer had formed on the end face on the inclined portion of each cut end face. In the reference example having a shape in which the cutting parts had left to right symmetry with respect to the normal line, as illustrated in Figure 10, a burr occurred on the cut end face. On the other hand, in examples G1 and G2, because each of the cutting parts had a shape with asymmetry from left to right with respect to the normal line, the deformation was concentrated on the side where the angle or The radius of the front end was large, and a crack propagated stably. As a result, as illustrated in Figure 30, no burr was produced M A / I / UOO I or as in the reference example. Therefore, it was found that by making the cutting parts of the die and punch have an asymmetric shape, the direction of propagation of a crack that occurs when cutting the workpiece can be controlled. Furthermore, with respect to examples G1 and G2, when the cut end face was checked after cutting a closed region, as illustrated in Figure 4, the cut end face was formed by cutting depressions, inclined faces and a Fracture surface and the proportion of inclined faces were large. The metallic coating remained on each inclined face and the amount of metallic coating on each inclined face had decreased toward the center of the sheet thickness from the surface of the metallic material. Therefore, it was also confirmed that when a metallic material with metallic coating is cut using the cutting tool illustrated in Figure 10 or Figure 11, the cut end face is extensively coated with the metallic coating. In addition, the direction of propagation of a crack that arose when cutting a workpiece was investigated in the case of using the cutting tool illustrated in Fig. 10 when the front end angles 0ia and 0ib were made different from each other. A galvanized steel sheet having a sheet thickness of 3.2 mm and a tensile strength of 460 MPa was used as the workpiece. In the process of cutting the workpiece, the front end radii Ri and R2 of the cutting edges were both made 0.05 mm, the front end angle 02a of the cutting edge was made the same as the front end angle 0,a the front end angle 02b was made the same as the front end angle Oib. Subsequently, the front end angles 0ia and 0ib were changed and cutting was performed 20 times with each cutting edge and the propagation direction of the generated cracks was confirmed. The results are shown in table 5. Table 5 M A / t / ¿U¿ I / UOO I ¿ó 0la+0lb [°] Wave [°] 01b [°] 0 la-01 b Γ] Crack propagation rate on the side of 01a Crack propagation rate on the side of 01b 90 45 45 0 50% 50% 90 47.5 42.5 5 70% 30% 90 50 40 10 80% 20% 90 52.5 37.5 15 80% 20% 90 55 35 20 80% 20% 90 57.5 32.5 25 85% 15% 90 60 30 30 9 5% 5% 90 62.5 27.5 35 95% 5% 90 65 25 40 95% 5% 90 67.5 22.5 45 95% 5% In Table 5 it can be seen that when (0ia-0ib) was made 5oo more and 45° or less, a crack propagated towards the side of 0ia, which was the largest angle. Furthermore, when the leading end angle 0ib became larger than the leading end angle 0ia, a crack propagated toward the side of 0ib, which is the largest angle. Therefore, the direction of propagation of a crack during cutting can be controlled by making the front end angles 0ia and 9ib different angles from each other. The same applies with respect to the front end angles 02a and 02b and a crack can be caused to propagate towards the larger angle side by making (02a-02b) or (02b02a), which is the angular difference between the angle 02a and angle 02b a difference that is 5oo more and 45° or less. In addition, the direction of propagation of a crack that arose when cutting a workpiece was investigated in the case of using the cutting tool illustrated in Figure 11, when the radii of the Riay Rib front ends were made different from each other. A galvanized steel sheet having a sheet thickness of 3.2 mm and a tensile strength of 460 MPa was used as the workpiece. In the process of cutting the workpiece, the front end angles 0i and 02 of the cutting edges were both made 60°, the front end radius R2a of the cutting edge was made the same as the front end radius Ria and the Front end radius R2b was made the same as the front end radius Rib. Subsequently, the radii of the front ends R|a and Rib were changed and cutting was performed 20 times with each cutting edge and the propagation direction of a generated crack was confirmed. The results are shown in table 6. ΜΛ / I / UOO I ¿or Table 6 Ria [mm] Rib [mm] Ria / Rib [-] Ria side crack propagation rate Rib side crack propagation rate 0.05 0.05 LO 50% 50% 0.055 0.05 1.1 40% 60% 0.075 0.05 1.5 30% 70% 0.15 0.05 3.0 25% 75% 0.5 0.05 10 20% 80% 1.5 0.05 30 15% 85% 5.0 0.05 100 5% 95% It can be seen from Table 6 that when the Ria / Rib ratio between the front end radii was made 1.1 or more and 100 or less, a crack propagated to the Rib side, which was the smallest front end radius. Additionally, when the Riadel front end radius became smaller than the Rib front end radius, a crack propagated to the Ria side, which is the smaller front end radius. Therefore, the direction of propagation of a crack during cutting can be controlled by making the Ria and Rib radii of the front ends different angles to each other. The same applies with respect to the front end radii R2a and R2b and propagation of a crack towards the front end radius side can be caused smaller by making the ratio R2a / R2b or R2b / R2abetween the end radii forwards be 1.1o more and 100 or less. H. Shape of front end of cutting edges The relationship between the shape of the leading end radius of the cutting edges and the fracture surface ratio of the workpiece being cut was investigated. A galvanized steel sheet having a sheet thickness of 3.2 mm and a tensile strength of 460 MPa was used as the workpiece. In the cutting tool using the process to cut the workpiece, the leading end angles θι and θ2 of the cutting edges were each made 60° and the leading end radii R, and R2 of the cutting edges were made made of 0.05 mm. However, the cutting edges of comparative examples H1 and H2 had a shape in which, as illustrated in Figure 31, the leading end was flat and the radius of the intersection between the flat portion and the inclined parts in the shape of wedge was 0.05 mm. A width RW of the flat portion was 0.2 mm in comparative example H1 and 0.02 mm in comparative example H2. In the example there was no flat portion at the leading end of the cutting edge and therefore the RW width of the flat portion was 0 mm. Table 7 shows the fracture surface ratio of the workpieces that were cut with the respective cutting tools. M A / t / ZUZ I / UOO I Zó Table 7 Case Fracture surface ratio [%] Width RW of the flat portion [mm] Comparative examples Η1 34 0.2 Comparative examples H2 29 0.02 Example 22 0 Based on Table 7, it was found that in the cases where the cutting edge was made flat (comparative examples H1 and H2), the fracture surface increased and the amount of coverage of the metal coating decreased compared to the case where the cutting edge had a curvature (example). This is because when the cutting edge is flat, material flow is suppressed when the workpiece is cut on the flat portion and more stress is generated during cutting. It is considered that, consequently, the breakage of the workpiece occurred earlier and the metal coating was split, and therefore the coating amount of the metal coating decreased. I. Closed region court Regarding the method of cutting a closed region of a workpiece, it was checked whether a workpiece could be cut or not. In the present verification, a metal-coated metal material was adopted as the workpiece that had been subjected to surface treatment, and a closed circular region was cut from the flat metal-coated metal material. The metal coated metal material was a galvanized steel sheet which had a tensile strength of 460 MPa and the thickness of the sheet was 3.2 mm. In the example, with respect to the cutting method of the second embodiment described above, first, using the cutting tool illustrated in Figure 14, an intermediate material was formed by cutting a closed region located more on the inner side than the position in which it was desired to cut to finally cut the metallic material with metallic coating and, subsequently, the intermediate material was cut in the final cutting position using the cutting tool illustrated in Figure 15. On the other hand, in a comparative example, not The formation of an intermediate material was carried out and a flat metal coated metal material was cut in the final cutting position using the cutting tool illustrated in Figure 15. In the die and punch of the cutting tool, illustrated in the Figure 15, the diameter of the cutting edge was 10 mm and the angle of the front end of the cutting part was 60°. Figure 32 is a view showing, with respect to when the metal coated metal material was cut using the cutting method of the example and using the cutting method of the comparative example, the analysis results showing the magnitude of damage to the material metal coated metal and also whether or not it was possible to cut the metal coated metal material. Furthermore, as a reference example, an analysis result is shown showing the magnitude of the damage of the metal-coated metal material when the metal-coated metal material was cut linearly and whether or not it was possible to cut the metal-coated metal material. Damage was expressed using damage values ​​calculated using the generalized CockcroftLatham formula (see non-patent document 1). The analysis results in Figure 32 show the magnitude of damage to the metal-coated metal material in gray scale, the whiter a portion is, the greater the damage is indicated and the easier it is for the metal-coated metal material to break. break. As illustrated in the reference example, in a case where the metal-coated metal material was cut linearly, it was found that a large amount of damage was imparted to the metal-coated metal material in the vicinity of the cutting edges of the cutting tool. court. In the reference example, because the metal coated metal material could move in one direction away from the tool when the die and punch are pushed relatively ΜΛ / t / ¿U¿ I / UOO I ¿Or towards each other, a large amount of damage could be imparted to the metal-coated metal material. Therefore, the metal material with metal coating could be cut reliably. Next, with respect to the comparative example, it was found that almost no damage was imparted to the metallic coated metal material in the vicinity of the cutting edges of the cutting tool. In the comparative example, because a through hole was not formed before cutting the closed region at the final cutting position, when the die and punch were pushed relatively toward each other, the metal-coated metal material could not move in a direction away from the tool. Therefore, it was not possible to impart damage to an extent that would generate a crack in the metal-coated metal material and the metal-coated metal material was not cut. On the other hand, with respect to the example, it was found that a large amount of damage was imparted to the metal-coated metal material in the vicinity of the cutting edges of the cutting tool. In the example, because a through hole was formed before cutting the closed region in the final cutting position, when the die and punch were pushed relatively toward each other, the metal-coated metal material could move in a direction away from the tool. Therefore, a large amount of damage could be imparted to the metal-coated metal material and the metal-coated metal material could be cut reliably. Furthermore, with respect to the example, when the cut end face was revised after cutting the closed region, as illustrated in Figure 4, the cut end face was formed from cutting depressions, inclined faces and a surface of fracture and the proportion of inclined faces was large. The metallic coating remained on each inclined face and the amount of metallic coating on each inclined face had decreased toward the center of the sheet thickness from the surface of the metallic material. Therefore, it was also confirmed that when a metallic material with metallic coating is cut using the cutting tool illustrated in Figure 15, the cut end face is extensively coated with the metallic coating. In addition, the fatigue characteristics of the test samples formed in the comparative example and the example illustrated in Figure 32 were investigated. As illustrated in Figure 33, a test sample 70 was formed by forming a through hole 71 of 10 mm in diameter in the center of a metal-coated metal material in the form of a plate having dimensions of 90 mm x 30 mm and forming through holes 73 of 7 mm in diameter in the four corner portions of the metal-coated metal material . Test sample 70 was subjected to a fatigue test with a strain ratio of -1 and a frequency of 25 Hz in atmospheric air at room temperature. In this ΜΛ / t / ZUZ I / UOO I Where appropriate, the loading stress applied to achieve a fatigue life of 107 cycles was defined as the fatigue limit. The fatigue test results are shown in figure 34 and table 8 below. ΜΛ / t / ¿U¿ I / UOO I ¿ó Table 8 TS [MPa] 460 616 790 1010 1210 Fracture surface ratio [%] Comparative example 0.78 0.80 0.82 0.84 0.85 Example 0.20 0.30 0.35 0.38 0.40 Fatigue limit [Mpa] Comparative example 224 300 397 498 600 Example 268 360 476 598 720 From Figure 34 and Table 8, it can be seen that regardless of the tensile strength of the test sample, the fatigue life of the test sample of the example was longer than the fatigue life of the sample. test of the comparative example. Furthermore, with respect to the test samples formed in the comparative example and the example illustrated in Figure 32, the metallic coating was removed by surface grinding and the same test was performed. As a result, results equivalent to those in Table 8 were obtained. Therefore, it was found that, when cutting using the cutting method of the example, an effect of improving the fatigue life can be obtained, regardless of the presence or absence of coating on the steel sheet. J. Verification of metal coated steel sheet Based on the above relational expressions (3) to (5), the relationship between the shape of a processed article and the result of conducting a 50-day exposure test was investigated with respect to covered materials A to H, which were metallic coated steel sheets and a steel sheet I shown in table 9 below. The results are shown in table 10. It is worth mentioning that, with respect to the evaluation of expression (3) mentioned above, a case where expression (3) was met is denoted by “X” and a case where the expression ( 3) was not satisfied is denoted with “Y”. Furthermore, to evaluate the corrosion resistance, each sample was placed in a sunny seaside environment with the cut end face (evaluation surface) of the sample facing upwards and the evaluation was carried out based on the corrosion resistance. the evaluation surface after exposure for 50 days. The states of the evaluation surfaces were classified as follows based on the proportion of the area in which red rust had occurred to the total area of ​​the evaluation surface (proportion of red rust appearance area). A (Excellent): The proportion of red rust appearance area is less than 30% B (Good): The proportion of red rust appearance area is 30% or more and less than 60% C (Acceptable): The proportion of red rust appearance area is 60% or more and less than 75% D (Unacceptable): The proportion of red rust occurrence area is 75% or more and less than 90% M A / I / UOO I E (unacceptable): the proportion of red rust occurrence area is 90% or more Table 9 Coated material Metallic coating Notes A Zn Hot dip galvanized steel sheet defined in JIS G3301 or G3302 B Zn-Fe - C 55%Al-Zn-1.6%Si Metallic coated steel sheet with 55% Al-Zn alloy by hot dip defined in JIS G3321 D Zn-1 l%Al-3%Mg-0.2%Si Metallic coated steel sheet with Zn-Al-Mg alloy by hot dip defined in JIS G3323 E Al-10% Yes Hot-dip metal-coated steel sheet defined in JIS G3314 F Cr - G Ni - H Sn - I No Cold-rolled steel sheet defined in JIS G3141 Table 10 No. Coated material Weight of metallic coating [both sides: g / m2] Sheet thickness [mm] Shape of lower and upper cutting parts End radius R (T1+T2) <T T3 / sheet thickness T Proportion of area of ​​appearance of red rust after 50 days of exposure Note 1 Example J1 A 900 3.2 equal 0.50 X 0.28 A 2 Example J2 A 900 3.2 equal 0.05 X 0.19 A 3 Comparative example J1 A 900 3.2 - - Y 0.78 D 4 Example J3 A 900 4.5 equal 0.50 X 0.30 A 5 Example J4 A 900 4.5 equal 0.05 X 0.28 A 6 Comparative Example J2 A 900 4.5 - - Y 0.63 D 7 Example J5 A 450 6.0 equal 0.50 X 0.32 B 8 Example J6 A 450 6.0 equal 0.05 X 0.30 B 9 Comparative example J3 A 450 6.0 - - Y 0.65 D 10 Example J7 A 900 6.0 equal 0.50 X 0.29 A 11 Example J8 A 900 6.0 equal 0.05 X 0.31 A 12 Comparative Example J4 A 900 6.0 - - Y 0.66 D 13 Example J9 A 900 9.0 equal 0.50 X 0.47 B 5 14 Example J10 A 900 9.0 equal 0.05 X 0.40 B 15 Comparative Example J5 A 900 9.0 - - Y 0.69 D 16 Example J11 B 90 0.2 equal 0.50 X 0.42 C 17 Example J12 B 90 0.2 equal 0.05 X 0.43 C 10 18 Comparative Example J6 B 90 0.2 - - Y 0.63 D 19 Example J13 B 90 0.8 equal 0.50 X 0.26 B 20 Example J14 B 90 0.8 equal 0.05 X 0.21 B 21 Comparative Example J7 B 90 0.8 - - Y 0.79 D i s 22 Example J15 C 150 1.6 equal 0.50 X 0.29 A 1J 23 Example J16 C 150 1.6 equal 0.05 X 0.18 A 24 Comparative example J8 C 150 1.6 - - Y 0.81 D 25 Example J17 D 90 3.2 equal 0.50 X 0.20 B 26 Example J18 D 90 3.2 equal 0.05 X 0.18 B 20 27 Example compare tive J9 D 90 3.2 - - Y 0.77 D 28 Example J19 D 180 3.2 equal 0.50 X 0.18 A 29 Example J20 D 180 3.2 equal 0.05 X 0.19 A 30 Comparative Example J10 D 180 3.2 - - Y 0.76 D 25 31 Example J21 D 270 3. 2 equal 0.50 X 0.08 A 32 Example J22 D 270 3.2 equal 0.05 X 0.19 A 33 Comparative Example Jll D 270 3.2 - - Y 0.74 D 34 Comparative Example J12 D 270 3.2 - - X 0.52 D Patent Document 7 30 35 Comparative Example J13 D 270 3.2 - - X 0.60 D Patent document 7 36 Example J23 D 450 4.5 equal 0.50 ΜΛ / t / ¿U¿ I / UOO I ¿ó 38 Comparative Example J14 D 450 4.5 - - Y 0.64 D 39 Example J25 D 450 6.0 equal 0.50 X 0.35 A 40 Example J26 D 450 6.0 equal 0.05 X 0.31 A 5 41 Comparative Example J15 D 450 6.0 - - Y 0.70 D 42 Example J27 E 120 2.3 equal 0.50 X 0.25 B 43 Example J28 E 120 2.3 equal 0.05 X 0.23 B 44 Comparative Example J16 E 120 2.3 - - Y 0.78 E 10 45 Example J29 F 150 2.3 equal 0.50 X 0.32 B 46 Example J30 F 150 2.3 equal 0.05 X 0.30 B 47 Comparative Example J17 F 150 2.3 - - Y 0.72 E 48 Example J31 G 180 2.3 equal 0.50 X 0.32 B 49 Example J32 G 180 2.3 equal 0.05 X 0.29 B 15 50 Comparative Example J18 G 180 2.3 - - Y 0.71 E 51 Example J33 H 250 2.3 Equal 0.50 x 0.34 C 52 Example J34 H 250 2.3 Equal 0.05 x 0.28 C 53 Comparative example J19 H 250 2.3 - - and 0.72 E 20 54 Comparative example J20 I 0 2.3 Equal 0.50 x 0.31 E 55 Example comparative J21 I 0 2.3 equal 0.05 X 0.33 E 25 56 Comparative example J22 I 0 2.3 - - Y 0.73 E M A / I / UOO I From Table 10, it can be seen that, in examples J1 to J34, as a result of satisfying the relationship of expression (3) mentioned above, the ratio of the red oxide appearance area of ​​the evaluation surface after the 50 day exposure was less than 75% for each sample. It is worth mentioning that with respect to examples J11 and J12, the thickness of the sheet was thin compared to the articles cut from the other examples. Therefore, if the metal-coated steel sheet is not firmly suppressed during the cutting process, the moment at which the cutting parts hit the metal-coated steel sheet will be deflected and deflection is likely to occur. However, the proportion of red rust appearance area of ​​the evaluation surface after the 50-day exposure test remained less than 75%. Furthermore, since the cut articles of examples J1 to J34 satisfied the relational expressions (4) and (5), it is assumed that a stable corrosion resistance of the cut end face could be exhibited. On the other hand, because the comparative examples J1 to J11 and J14 to J19 did not satisfy the ratios of expressions (3) to (5) mentioned above, the ratio of the red rust appearance area of ​​the evaluation surface after the exposure test 50 days was 75% or more in each of the comparative examples J1 to J11 and J14 to J19. Furthermore, with respect to comparative examples J12 and J13, the evaluation of cut articles that were cut based on the technique described in patent document 7 was carried out. In this case also, because the relationship was not met From the aforementioned expression (5), the area ratio of red rust appearance of the evaluation surface after the 50-day exposure test was 75% or more in each of the comparative examples J12 and J13. Comparative examples J20 to J22 were each an article sheared from a cold rolled steel sheet without a metal coating layer. Therefore, although the shape of the cut end face of the comparative examples J20 and J21 was similar to the shape of the cut end face of the examples, because none of the comparative examples J20 to J22 had resistance to the corrosion, the red rust occurrence area ratio of the evaluation surface after the 50-day exposure test was 75% or more in each of the comparative examples .120 to .122. Although preferred embodiments of the present invention have been described in detail above with reference to the accompanying figures, the present invention is not limited to the above examples. It is clear that a person having common knowledge in the technical field to which the present invention belongs will be able to devise various examples of changes and modifications within the category of the technical idea described in the appended claims and it should be understood that they also naturally belong to the technical field of the present invention. For example, although in the above embodiments the workpiece is a metal-coated steel sheet, the present invention is not limited to this example. The workpiece may be any type of workpiece formed by coating the surface of a base material with a coating material. For example, a metallic material such as a steel sheet can be used as a base material and a composite material of Zn, Al or an alloy of these elements, an oxide coating, a paint material, a resin material or similar used as coating material. Accordingly, the workpiece may be a coated steel sheet obtained by coating the surface of a metal material as a base material with paint or it may be a laminated film-laminated steel sheet obtained by laminating a film on a steel sheet. Alternatively, it is also possible to produce a cut article from a coating material composed of a base material and a coating material. Examples of facing material M A / I / UOO I ¿ó include a Ni-clad copper material having a Cu foil as a base material and a Ni foil as a coating material. It is worth mentioning that the workpiece is not limited to a material covered with a single layer and can be covered with multiple layers. For example, the surface of the metal coated steel sheet mentioned above may be subjected to chemical treatment, painting, lamination or the like. Furthermore, according to the cutting method of the present invention, it is also possible to similarly form an article obtained by cutting a workpiece in which a resin material such as plastic was used as the base material and a metal material was used as Cu, Cr, Ag, Au or Pt as coating material. When cutting a resin material, such as plastic, that is covered with a metal, the electrical conductivity of the end face is lost. Furthermore, when the exposed proportion of the resin is high, it is easy to charge and therefore the appearance of sparks or the like is a problem. Therefore, by cutting such resin material using the cutting method described above, it is possible to improve the electrical conductivity of the cut end face and prevent it from charging. Additionally, in the case of a coated material, the required purpose when cutting will differ depending on the combination with the workpiece, as well as the intended use. However, by cutting the workpiece using the above-mentioned cutting method, the corrosion resistance and chemical resistance and the like of the base material of the cut end face can be improved. In addition, the electrical conductivity, thermal conductivity, magnetism and the like of a part or the entire face of the cut end can be improved compared with the conventional cutting method. In the case of coating and laminated films, by cutting the workpiece using the above-mentioned cutting method, as well as improving the corrosion resistance of the base material, it is also possible to suppress the appearance of bulges under the coating film , improve the appearance because the base material is not exposed and improve the insulation property of a part or the entire cut end face. Therefore, when cutting a workpiece using the above-mentioned cutting method, it is possible to make a feature possessed by a coating material on a flat surface also be imparted on a face of the cut end. It is worth mentioning that a function possessed by a coating material is not limited to the above-mentioned example and the function of the coating material can be exhibited according to the intended use of the coating material. In other words, by means of the cutting method according to the present embodiment, when a workpiece is cut, the occurrence of a situation in which the performance of the workpiece is reduced after cutting can be suppressed. This applies similarly with respect to cutting an untreated material and not just cutting a workpiece that has undergone a surface treatment. By M A / I / UOO I Or example, using the cutting method according to the present embodiment, regardless of the presence or absence of a coating material, a decrease in the fatigue life of the workpiece can be suppressed. cut work. It is worth mentioning that the following configurations are also included in the technical scope of the present invention. (Al) A cutting method for cutting a workpiece subjected to a surface treatment, using a cutting tool that includes a die and a punch, the cutting method includes: arranging the workpiece between the die and the punch and in a state in which a first wedge-shaped cutting part of the die and a second cutting part of the wedge-shaped punch are opposite, pushing the punch relative to the side of the die to cut the workpiece. (A2) The cutting method according to point (Al) above, where: a blank holder that is arranged between the die and the punch is provided in at least one of the die and the punch and in a state in which the workpiece is clamped by the blank holder, the punch is pushed relatively to the side of the die. (A3) The cutting method, according to points (Al) or (A2) above, where a front end angle θι of the first cutting part and a front end angle 02 of the second cutting part are , each, 10° or more and 120° or less. (A4) The cutting method according to point (A3) above, wherein a front end angle 0i of the first cutting part and a front end angle 02 of the second cutting part are each of 30° or more and 90° or less. (A5) The cutting method, according to points (A3) or (A4) above, where 01 / Θ2 or Θ2 / Θ1 which is a ratio between a front end angle 0, of the first cutting part and the front end angle Θ2 of the second cutting part is less than 4. (A6) The cutting method, according to point (A5) above, where Θ1 / Θ2 or Θ2 / Θ1 which is a relationship between a front angle 0i of the first cutting part and a front angle Θ2 of the second cutting part is less than 2. (A7) The cutting method, according to any of the points (Al) to (A6) above, where a front end radius Ri of the first cutting part and a front end radius R2 of the second part of cut are each 0.5% or more and 35.0% or less of a sheet thickness. (A8) The cutting method, according to point (A7) above, wherein the front end radius Ri of the first cutting part and the front end radius R2 of the second cutting part are each of 3.0% or more and 10.0% or less of a sheet thickness. ΜΛ / I / UOO I ¿ó (Α9) The cutting method, according to points (A7) or (A8) above, where Ri / R2o R2 / Ri, which is a ratio between the front end radius Ri of the first cutting part and the front end radius R2 of the second cutting part is less than 100. (A10) The cutting method, according to point (A9) above, where R| / R2o R2 / Ri, which is a ratio between the front end radius Ri of the first cutting part and the end radius front R2 of the second cutting part is less than 10. (Al 1) The cutting method, according to any of the points (Al) to (A10) above, wherein the die and the punch are made to face each other with a position of the front end of the first part of cutting and a position of the front end of the second cutting part aligned with each other. (A12) The cutting method, according to any of the points (Al) to (A 10) above, wherein, when the first cutting part of the die and the second cutting part of the punch are opposite, an amount of deviation between a position of the front end of the first cutting part and the position of the front end of the second cutting part are made 50% or less of the thickness of the sheet. (A13) The cutting method, according to any of the points (Al) to (A12) above, wherein the first cutting part of the die and the second cutting part of the punch have an identical shape and are arranged symmetrically with with respect to the work piece. (Al4) The cutting method, according to any of the above points (Al) to (Al3), wherein the cutting of the workpiece is carried out by a plurality of cutting processes. (A15) The cutting method, according to point (A14) above, the plurality of cutting processes that include a first cutting process and a second cutting process that is performed after the first cutting process, wherein: In the second cutting process, at least one of the following is performed: a front end angle θι of the first cutting part in the second cutting process becomes smaller than a front end angle θι of the first cutting part in the first cutting process and a front end angle θ2of the second Cutting part in the second cutting process is made smaller than a front end angle θ2 of the second cutting part in the first cutting process, and subsequently the workpiece is cut. (A16) The cutting method, according to point (A 14) or (A 15) above, the plurality of cutting processes including a first cutting process and a second cutting process that is performed after the first process cutting, where: In the second cutting process, at least one of the following is performed: ΜΛ / t / ZUZ I / UOO I Zó a front end radius Ri of the first cutting part in the second cutting process becomes smaller than a front end radius Ri of the first cutting part in the first cutting process cutting and a front end radius R2 of the second cutting part in the second cutting process is made smaller than a front end radius R2 of the second cutting part in the first cutting process and; Subsequently, the workpiece is cut. (A 17) The cutting method, according to any of the points (A 14) to (A 16) above, wherein, among the plurality of cutting processes, when a radius of the front end of the first cutting part is defined as Ri, a radius of the front end of the second cutting part is defined as R2, and the thickness of the workpiece sheet is defined as t, a stroke S of the punch in a first cutting process satisfies the expression ( To the next one: (R i+R2)<S< {t-(R i+R2)} ...(al). (Al 8) The cutting method, according to point (A 17) above, where the stroke S of the punch in the first cutting process satisfies the following expression (a2): (R i+R2) x2<S< {t-(Ri+R2)x2}.. ,(a2). (Al9) The cutting method, according to any of the points (Al) to (Al8) above, where: a workpiece trim width is a distance between an end portion of the workpiece and a cutting position of the workpiece and when the radius of the front end of the first cutting part is defined as Ri, the Radius of the front end of the second cutting part is defined as R2, and the thickness of the workpiece sheet is defined as t, a cutting width D of the workpiece satisfies expression (a3), below: R <D<5t...(a3) R = Min (Ri, R2). (A20) The cutting method, according to point (A 19) above, where a cutting width D of the workpiece satisfies expression (a4) below: 3R<D<t ... (a4). (A21) The cutting method, according to any of (Al) to (A20) above, wherein the workpiece is a material having a tensile strength of 270 MPa or more. (A22) The cutting method, according to point (A21) above, wherein the workpiece is a material having a tensile strength of 590 MPa or more. (A23) The cutting method, according to any of (Al) to (A22) above, wherein the workpiece is a metal sheet with a metallic coating. (A24) A cutting tool, including: M A / t / ¿U¿ I / UOO I ¿or a die on which a workpiece can be placed and which has a first wedge-shaped cutting part and a punch which has a second wedge-shaped cutting part wedge that is provided facing the first cutting part and that is provided facing the die and so that it can be moved relatively relative to the side of the die. (A25) The cutting tool, according to point (A24) above, wherein in a state in which the workpiece is arranged between the die and the punch, the workpiece is cut by pushing the punch relative to next to the die. (Bl) A cutting method for cutting a workpiece subjected to a surface treatment, using a cutting tool including a die and a punch, wherein a first wedge-shaped cutting part of the die and a second part of Wedge-shaped cutting of the punch have an asymmetrical shape with respect to a normal line on a cutting edge, respectively, the cutting method including: arranging the workpiece between the die and the punch and in a state in which a first wedge-shaped cutting part of the die and a second cutting part of the wedge-shaped punch are opposite each other, pushing the punch relative to the side of the die to cut the workpiece. (B2) The cutting method, according to point (Bl) above, where: a blank holder that is arranged between the die and the punch is provided in at least one of the die and the punch and in a state in which the workpiece is clamped by the blank holder, the punch is pushed relatively to the side of the die. (B3) The cutting method, according to points (Bl) or (B2) above, where a front end angle θι of the first cutting part and a front end angle 02of the second cutting part are, each, 10° or more and 120° or less. (B4) The cutting method, according to point (B3) above, wherein a front end angle θι of the first cutting part and a front end angle θ2of the second cutting part are each of 30° or more and 90° or less. (B5) The cutting method, according to point (B3) or (B4) above, where: a front end angle θι of the first cutting part is divided into two angles 9ia and θib by a normal line on a cutting edge of the first cutting part, a front end angle θ2of the second cutting part is divided into two angles 92a and 92b by a normal line on a cutting edge of the second cutting part and M A / t / ¿U¿ I / UOO I ¿ó (Oia-Oib) or (Oib-Oia), which is an angular difference between the angle 0ja and the angle Oib, and (02a~02b) or (02b-O2a) , which is an angular difference between angle 02a and angle 02b, are each 5° or more and 45° or less. (B6) The cutting method, according to point (B5) above, where (0ia-0ib) or (0ib0ia), which is an angular difference between the angle 0ia and the angle Oib, and (02a-02b) or (02b-02a), which is an angular difference between angle 02a and angle 02b, are each 10° or more and 30° or less. (B7) The cutting method, according to any of points (B1) to (B6) above, where: when a front end radius Ri of the first cutting part is taken as an average value of the respective front end radii Ri and Rib of the first cutting part, which are formed when the front end radius Ri is divided into two by a normal line on a cutting edge of the first cutting part and a front end radius R2 of the second cutting part is taken as an average value of the respective front end radii R2a and R2b of the second cutting part that are formed when the leading end radius R2 is bisected by a normal line on a cutting edge of the second cutting part, the leading end radii Ri and R2 are 0.5% or more and 35.0% or less of the thickness of the sheet, respectively. (B8) The cutting method, according to point (B7) above, where the radii of the front ends Ri and R2 are 3.0% or more and 10.0% or less of the thickness of the sheet, respectively. (B9) The cutting method, according to the previous point (B7) or (B8), wherein a ratio Ria / Rib or Rib / Riabetween two leading end radii formed when the leading end radius Ri of the first cutting part is divided into two and a ratio R2a / R2b or R2b / R2abetween two front end radii forms when the front end radius R2of the second cutting part is divided into two are each 1.1o more and 100o less. (B10) The cutting method, according to point (B9) above, wherein a ratio Ria / Rib or Rib / Riabetween two leading end radii formed when the leading end radius Ri of the first cutting part is divided into two and a ratio R2a / R2b or R2b / R2abetween two front end radii that is formed when the front end radius R2 of the second cutting part is divided into two is each 5 or more and 20 or less. (B11) The cutting method, according to any of points (Bl) to (B10) above, wherein the die and the punch are arranged facing each other with a forward end position of the first cutting part and a front end position of the second cutting part aligned with each other. ΜΛ / t / ¿U¿ I / UOO I ¿ó (Β12) The cutting method, according to any of the points (Bl) to (B10) above, where, when the first cutting part of the die and the second cutting part of the punch are opposite, an amount of deviation between a position of the front end of the first cutting part and the position of the front end of the second cutting part is made 50% or less of the thickness of the sheet. (B13) The cutting method, according to any of the preceding points (B1) to (B12), wherein the first cutting part of the die and the second cutting part of the punch have an identical shape and are arranged symmetrically with with respect to the work piece. (B14) The cutting method, according to any of the points (Bl) to (B13) above, wherein the cutting of the workpiece is carried out by performing a plurality of cutting processes. (B15) The cutting method, according to any of points (Bl) to (B14) above, where: A workpiece trimming width is a distance between an end portion of the workpiece and a cutting position of the workpiece and when: a front end radius Ri of the first cutting part is taken as an average value of the respective front end radii R|a and Rib of the first cutting part, which are formed when the front end radius Ri is divided into two by a normal line on a cutting edge of the first cutting part, a front end radius R2 of the second cutting part is taken as an average value of the respective front end radii R2a and R2b of the second cutting part. cutting, which are formed when the leading end radius R2 is bisected by a normal line on a cutting edge of the second cutting part and a sheet thickness of the workpiece is defined as t, a cutting width D of the workpiece satisfies the following expression (bl): R<D<5t ... (bl) R = Min (Rla, Rib, R2a, R2b). (B16) The cutting method, according to point (B15) above, where a cutting width D of the workpiece satisfies expression (b2) below: 3R<D<t ... (b2). (B17) The cutting method, according to any of points (Bl) to (B16) above, wherein the workpiece is a material having a tensile strength of 270 MPa or more. (B18) The cutting method, according to point (B17) above, wherein the workpiece is a material having a tensile strength of 590 MPa or more. ΜΛ / t / ¿U¿ I / UOO I ¿ó (Β19) The cutting method, according to any of the points (Bl) to (B18) above, where the workpiece is a coated metal sheet metal. (B20) A cutting tool that includes: a die on which a workpiece can be placed and having a first wedge-shaped cutting part and a punch having a second wedge-shaped cutting part that is provided facing the first cutting part and which is provided facing the die and so that it can move relative to the side of the die, where: The first cutting part and the second cutting part have an asymmetric shape with respect to a normal line on a cutting edge, respectively. (B21) The cutting tool, according to point (B20) above, wherein, in a state where the workpiece is arranged between the die and the punch, the workpiece is cut by pushing the punch relative to next to the die. (Cl) A cutting method for cutting a workpiece undergoing surface treatment, including: forming, from the workpiece, an intermediate material having a final shape region and an excess region provided along an edge of the final shape region and using a cutting tool including a die and a punch in each of which a cutting part is formed in a closed shape in correspondence with the edge of the final shaped region, in a state where a first wedge-shaped cutting part of the die and a second cutting part The wedge-shaped punches are opposite each other, pushing the punch relatively toward the side of the die to cut the intermediate material. (C2) The cutting method, according to point (C1) above, where the die and the punch are positioned so that they are facing each other, with a front end position of the first cutting part and a front end of the second cutting part aligned with each other. (C3) The cutting method, according to point (Cl) above, wherein, when the first cutting part of the die and the second cutting part of the punch are opposite, an amount of deviation between a front end position of the first cutting part and the position of the front end of the second cutting part is 50% or less of the thickness of the sheet. (C4) The cutting method, according to any of the points (Cl) to (C3) above, wherein the cutting of the intermediate material is carried out by performing a plurality of cutting processes. M A / I / UOO I ¿ó (C5) The cutting method, according to point (C4) above, the plurality of cutting processes that include a first cutting process and a second cutting process that is carried out after the first cutting process, where: In the second cutting process, at least one of the following is carried out: a front end angle 0, of the first cutting part in the second cutting process becomes smaller than a front end angle θι of the first cutting part in the first cutting process and a front end angle 02 of the second cutting part in the second cutting process is made smaller than an angle of the front end 02 of the second cutting part in the first cutting process, and subsequently the intermediate material is cut. (C6) The cutting method, according to points (C4) or (C5) above, the plurality of cutting processes including a first cutting process and a second cutting process that is performed after the first cutting process , where: In the second cutting process, at least one of the following is carried out: a front end radius Ri of the first cutting part in the second cutting process is made smaller than a front end radius Ri of the first cutting part in the first cutting process and a front end radius R2 of the The second cutting part in the second cutting process is made smaller than a front end radius R2 of the second cutting part in the first cutting process, and subsequently the intermediate material is cut. (C7) The cutting method, according to any of the points (C4) to (C6) above, wherein among the plurality of cutting processes, when a radius of the front end of the first cutting part is defined as Ri , a leading end radius of the second cutting part is defined as R2 and the thickness of the workpiece sheet is defined as t, a stroke S of the punch in a first cutting process satisfies the following expression (the) : (Ri+R2)<S<{t-(Ri+R2) ...(el). (C8) The cutting method, according to point (C7) above, where the stroke S of the punch in the first cutting process satisfies the following expression (c2): (Ri+R2)x2<S<{t -(Ri+R2)x2} ... (c2). (C9) The cutting method, according to any of points (Cl) to (C8) above, where: when cutting the intermediate material, an intermediate material trimming width is a distance between an end portion of the intermediate material and a cutting position of the intermediate material which is an edge of the final shape region and ΜΛ / t / ZUZ I / UOO I Zó when the radius of the front end of the first cutting part is defined as Ri, the radius of the front end of the second cutting part is defined as R2, and the thickness of the sheet of the workpiece working width is defined as t, a trim width D of the intermediate material satisfies the expression (c3) below: R<D<5t ... (c3) R = Min(Ri, R2). (CIO) The cutting method, according to point (C9) above, where the cutting width D of the intermediate material satisfies the expression (c4) below: 3R<D<t ... (c4). (C11) The cutting method, according to any of the points (Cl) to (CIO) above, wherein the formation of the intermediate material is carried out by punching, drilling or laser cutting. (C12) The cutting method, according to any of the points (Cl) to (Cl 1) above, where, in the case where the intermediate material does not break during the cutting of the intermediate material, the cutting method includes also cut the excess region of the intermediate material. (C13) The cutting method, according to any of the points (Cl) to (C12) above, where, in the process to form the intermediate material, between the portions that were divided into two by eliminating a closed region of the workpiece, a portion in which a through hole is formed by removing the closed region is adopted as an intermediate material. (C14) The cutting method, according to any of the points (Cl) to (C12) above, where in the process to form the intermediate material, between the portions that were divided into two by eliminating a closed region of the piece workpiece, a portion of the closed region that is extracted from the workpiece is adopted as an intermediate material. (C15) The cutting method, according to any of (Cl) to (C14) above, wherein the workpiece is a material having a tensile strength of 270 MPa or more. (C16) The cutting method, according to point (C15) above, wherein the workpiece is a material having a tensile strength of 590 MPa or more. (C17) The cutting method, according to any of the points (Cl) to (C16) above, wherein the workpiece is a metal sheet with metallic coating. LIST OF REFERENCE SIGNS cutting article 3a Cut End Face Workpiece (steel sheet with metal coating) 5a Metal material (steel sheet) M A / I / UOO I 5b Coating layer (metallic coating) 50, 100 Cutting tool 51, 110 Die 111, 121 Base 113 First cutting part 52, 120 Punch 123 Second cutting part 130 Blank holder 131, 132, 133, 134, 140 Pad MA / t / ¿U¿ I / UOO I ¿ó

Claims

1. A cutting method for cutting a workpiece using a cutting tool comprising a die and a punch, including: placing the workpiece between the die and the punch, and in a state in which a first wedge-shaped cutting portion of the die and a second wedge-shaped cutting portion of the punch are opposed, pushing the punch relatively towards the side of the die to cut the workpiece; characterized in that: a front end angle θι of the first cutting portion and a front end angle θ2 of the second cutting portion are each 10° or more and 120° or less, and a front end radius Ri of the first cutting portion and a front end radius R2 of the second cutting portion are each 0.5% or more and 35.0% or less of the sheet thickness.

2. The cutting method according to claim 1, characterized in that the workpiece is a multi-layered material formed by coating a surface of a base material with a coating material.

3. The cutting method, according to claim 1 or 2, characterized in that the front end angle θι of the first cutting part and the front end angle θ2 of the second cutting part are each 30° or more and 90° or less.

4. The cutting method, in accordance with any of claims 1 to 3, characterized in that the front end radius Ri of the first cutting part and the front end radius R2 of the second cutting part are each 1.5% or more and 10.0% or less of a sheet thickness.

5. The cutting method, in accordance with any of claims 1 to 4, characterized in that the cutting of the workpiece is carried out by a plurality of cutting processes.

6. The cutting method according to claim 5, characterized in that: the plurality of cutting processes includes a first cutting process and a second cutting process that is performed after the first cutting process, and in the second cutting process at least one of the following is performed: a front end angle θι of the first cutting part in the second cutting process is made smaller than a front end angle θι of the first cutting part in the first cutting process and a front end angle θ2 of the second cutting part in the second cutting process is made smaller than a front end angle θ2 of the second cutting part in the first cutting process, MA / t / ZUZ I / UOO I Zó and subsequently the workpiece is cut.

7. The cutting method according to claim 5 or 6, characterized in that: the plurality of cutting processes includes a first cutting process and a second cutting process performed after the first cutting process, and in the second cutting process at least one of the following is performed: a front end radius Ri of the first cutting part in the second cutting process is made smaller than a front end radius Ri of the first cutting part in the first cutting process, and a front end radius R2 of the second cutting part in the second cutting process is made smaller than a front end radius R2 of the second cutting part in the first cutting process, and the workpiece is subsequently cut.

8. The cutting method, according to any of claims 5 to 7, characterized in that: among the plurality of cutting processes, when a radius of the front end of the first cutting part is defined as Ri, a radius of the front end of the second cutting part is defined as R2, and a thickness of the workpiece sheet is defined as t, a stroke S of the punch in a first cutting process satisfies the following expression (A): (Ri+R2) <S<{t-(Ri+R2)} ...(A).

9. The cutting method, according to any of claims 1 to 8, characterized in that: a workpiece trimming width is a distance between an end portion of the workpiece, and a cutting position of the workpiece, and where a front end radius of the first cutting portion is defined as Ri, a front end radius of the second cutting portion is defined as R2, and a sheet thickness of the workpiece is defined as t, a workpiece trimming width D satisfies the expression (B) below: R <D<3t ... (B) R = Min(Ri, R2).

10. The cutting method, in accordance with any of claims 1 to 9, characterized in that: a first wedge-shaped cutting part of the die, and a second wedge-shaped cutting part of the punch have an asymmetrical shape with respect to a normal line on a cutting edge, respectively.

11. The cutting method, according to claim 10, characterized in that: a front end angle θι of the first cutting part is divided into two angles 0ia, and 0ib by a normal line on a cutting edge of the first cutting part, and a front end angle 02 of the second cutting part is divided into two angles 02a, and 02b by a normal line on a cutting edge of the second cutting part, and (0ia-0ib) or (0ib-0ia), which is an angular difference between angle 0ia, and angle 0ib and (02a-02b) or (02b-02a), which is an angular difference between angle 02a, and angle 02b, are each 5° or more, and 45° or less.

12. The cutting method according to claim 10 or 11, characterized in that: when a front end radius Ri of the first cutting part is taken as an average value of the respective front end radii Ria and Rib of the first cutting part, which are formed when the front end radius Ri is bisected by a line normal to a cutting edge of the first cutting part, and a front end radius R2 of the second cutting part is taken as an average value of the respective front end radii R2a and R2b of the second cutting part, which are formed when the front end radius R2 is bisected by a line normal to a cutting edge of the second cutting part, the front end radii Ri and R2 are 0.5% or more and 35.0% or less of the sheet thickness, respectively.

13. The cutting method, according to claim 12, characterized in that: a Ria / Rib or Rib / Ria ratio between two front end radii formed when the front end radius Ri of the first cutting part is divided in two and an R2a / R2b or R2b / R2a ratio between two front end radii, which are formed when the front end radius R2 of the second cutting part is divided in two are, each, 1.10 or more and 100 or less.

14. The cutting method according to any one of claims 1 to 9, comprising: forming, from the workpiece, an intermediate material having a final shape region and a proportionate excess region along an edge of the final shape region; and using a cutting tool including a die and a punch, each of which has a cutting portion formed in a closed shape corresponding to the edge of the final shape region, in a state wherein a first wedge-shaped cutting portion of the die and a second wedge-shaped cutting portion of the punch are opposed, pushing the punch relatively towards the side of the die to cut the intermediate material.

15. A cut article formed by cutting a workpiece, wherein a cut-end face of the cut article comprises: a first inclined face inclined from a first surface towards a center in a direction of the sheet thickness, ML / t / ¿U¿ I / UOO I ¿O a second inclined face inclined from a second surface towards the center in the direction of the sheet thickness, and a fracture surface formed between the first inclined face and the second inclined face, wherein the thickness of an inclined face when the cut-end face is viewed from the front satisfies the relational expression (C) below: (T,+T2) <T ...(C) Ti=Aicos0i, T2=A2cos02 where T । represents a thickness of the first inclined face when the cut end face is viewed from the front, T2 represents a thickness of the second inclined face when the cut end face is viewed from the front, Ai represents a length of the first inclined face when the cut end face is viewed from the side, A2 represents a length of the second inclined face when the cut end face is viewed from the side, 0, represents an angle of inclination of the first inclined face, 02 represents an angle of inclination of the second inclined face and T represents a thickness of the workpiece sheet.

16. The cut article, according to claim 15, characterized in that a thickness T3 of the fracture surface when the cut end face is viewed from the front satisfies the relational expression (D) below: 0 <T3<0.5T ... (D).

17. The cut article, according to claim 15 or 16, characterized in that: the workpiece is a multi-layered material formed by coating a surface of a base material with a coating material, and at least a portion of the first inclined face and the second inclined face are coated with the coating material covering the surface of the base material.

18. The cut article, according to claim 17, characterized in that: at least a portion of the first inclined face is coated with a coating material covering the first surface of the base material, and at least a portion of the second inclined face is coated with a coating material covering the second surface of the base material.

19. The cut article, according to claim 17 or 18, characterized in that: a thickness t of the base material sheet is 0.2 mm or more and 10 mm or less. ML / I / UOO I ¿ó