[0001]The present disclosure, the first metal plate and the workpiece to the second metal plate is joined by welds, to cutting method according to a press die for cutting by shearing so as to cross the weld. Background technique [0002]Shearing such as punching or piercing of the sheet metal by press, production efficiency is high, also because the processing cost is inexpensive, widely used in the processing of such electronic devices and components for automobiles. However, the use of the shearing process, the high-strength steel sheet of a tensile strength exceeding 1000 MPa, the residual stress of the punching edge is increased, (also referred to as location cracking or delayed fracture) hydrogen embrittlement cracks become likely to occur, and fatigue properties is lowered. [0003] 　In the case of shearing the workpiece which is joined by welding the steel plates of the same or different, with the shearing surface of the weld and heat affected zone (hereinafter sometimes referred to as "HAZ portion".), Hydrogen embrittlement resistance and fatigue properties, it is known to decrease. [0004] 　Punched end surface of the workpiece after punching has been performed, and sagging of the workpiece is formed pressed by a punch, the space between the punch and the die (hereinafter, simply referred to as "clearance". ) shear plane and the workpiece is drawn is formed by locally stretched into, fracture surface and the workpiece is formed by breaking during the shearing surface formed, punching the back surface of the workpiece Bali is present to occur. [0005] 　Normally, to improve the end face characteristics after processing the to the required value generation amount of sagging or shearing surface and fracture surface and burrs, or stretch flange formability and fatigue properties and hydrogen embrittlement resistance and the like in punched end surface of the above adjust the clearance and tool shape aiming for. [0006] 　For example, Japanese Patent Application Publication 2006-224151 Patent Publication (hereinafter referred to as Patent Document 1.), Having a punch and / or bending blade having a shape of the convex portion to the tip portion of the cutting edge of the die, and , using a tool having a predetermined radius of curvature, the blade shoulder angle, by the clearance 25% or less, it is disclosed that can reduce the work hardening and tensile residual stress at the end face after processing. [0007] 　Further, "63rd plastic working Federation Lecture Proceedings, 338 pages" The (hereinafter, Non-Patent Document 1 referred to.) Clearance, as 1% or less at a thickness ratio, the shearing under high compressive stress was carried out, it has been reported to reduce the tensile residual stress in the vent surface. Japanese Patent Application Publication 2014-111283 Patent Publication (hereinafter referred to as Patent Document 2.), The direction which is excellent in ductility, a cutting edge direction of the punch of the wedge shape by 10 degrees or less, piercing with excellent burring properties method of performing have been introduced. Summary of the Invention Problems that the Invention is to Solve [0008] 　By controlling the shearing, if it is possible to reduce the residual stress of the shearing surface, it is possible to improve the hydrogen embrittlement characteristics and fatigue characteristics (e.g., see Patent Document 1 and Non-Patent Document 1). However, there is a drawback in punching surface having a uniform end surface properties formed by the method of Patent Document 1. That is, when a uniform punch shape to the cutting ridge line direction, there is a problem that cracking tends to occur at lower weld and heat-affected zone of the residual stress of the shear edge is higher ductility and toughness. [0009] 　However, as in Non-Patent Document 1 method, if the clearance was set to 1% or less at a thickness ratio, a slight misalignment of the punch, galling occurs. Further, when the clearance is changed due to wear of the side surface of the punch and the die, the effect of improving improving effect and the hydrogen embrittlement resistance of high fatigue characteristics residual stress of the shearing surface there is a problem that it is not sufficiently obtained. [0010] 　The present disclosure is intended to provide a cutting method according to a press die which can reduce residual stress in shearing surface in at least one of the weld and heat-affected zone of the workpiece. Means for Solving the Problems [0011] 　Cutting method according to a press die according to one embodiment of the present disclosure, the workpiece to the first metal plate and the second metal plate is heat-affected zone around the weld together are joined by welding unit for punch having a protrusion protruding toward the workpiece side than the flat portion, of the heat affected zone and the weld portion by the projecting portion prior the cleavage of the workpiece by the flat portion positioned at a position at least one of the cutting is started, the relative movement of said punch and die in the positioning position, the cutting the workpiece by shearing so as to cross the weld in the workpiece to. Effect of the invention [0012] 　According to the present disclosure, the shearing surface of the weld or heat affected zone of the workpiece, it is possible to reduce the residual stress. BRIEF DESCRIPTION OF THE DRAWINGS [0013] FIG. 1 is a schematic perspective view showing a cutting device of the first embodiment. FIG. 2 is a schematic front view of the Z direction of FIG. 1 showing a cutting apparatus of the first embodiment. 3 is a schematic side view in the Y direction of FIG. 1 showing a cutting apparatus of the first embodiment. 4 is a schematic top view in the X direction of FIG. 1 showing a cutting apparatus of the first embodiment. 5 is a schematic front view of the Z direction of FIG. 1 showing the punch of the first embodiment. 6 is an enlarged view of FIG. 5 illustrating the relationship between the protrusion of the punch and the workpiece according to the first embodiment. 7 is an enlarged view of FIG. 6 illustrating a protruding portion according to the first embodiment. 8 is a schematic side view in the Y direction of FIG. 1 illustrating a protruding portion according to the first embodiment. It is a view similar to FIG. 6 for use in explaining in positioning the second metal plate side of the workpiece with respect to FIG. 9A] punch. It is a view similar to FIG. 6 for use in explaining in positioning the first metal plate side of the workpiece with respect to FIG. 9B] punch. Is [10] a schematic front view illustrating a state in which the protrusion of the punch according to the first embodiment is sheared a portion of the welded portion and the second heat-affected zone with a portion of the first heat-affected zone . 11 is a schematic front view of projecting portions of the punch according to the first embodiment will be described a state of shear a portion and the second heat-affected zone of the weld. 12 is a schematic front view illustrating a state in which the protrusion of the punch according to the first embodiment is sheared part of the second heat-affected zone. 13 is a schematic front view illustrating the shape of the protrusion according to the second embodiment. 14 is a schematic front view illustrating the shape of the protrusion according to the third embodiment. 15 is a schematic front view illustrating the shape of the protrusion according to the fourth embodiment. FIG. 16 is a schematic front view illustrating the shape of the protrusion according to a fifth embodiment. 17 is a schematic front view illustrating the shape of the protrusion according to a sixth embodiment. FIG. 18 is a schematic side view illustrating the shape of the protrusion according to a seventh embodiment. 19 is a schematic side view illustrating the shape of the protrusion according to the eighth embodiment. FIG. 20 is a graph showing the residual stress at the second boundary line for the distance from the center of the cutting edge portion of the projecting portion to the second boundary line. DESCRIPTION OF THE INVENTION [0014] 　First, the present inventors have the workpiece joined by welding rolled two kinds of metal plate is sheared with a flat punch and a die, were investigated residual stress in shearing surface. As a result, the weld and heat affected zone, comparable with other parts (the general portion), or more tensile residual stress is found to remain. [0015] 　In the weld and heat-affected zone, the weld time the crystal grains are coarsened by heat input, ductility and toughness are lowered. Therefore, by shearing, the tensile stress remains in the shearing plane (punched end face), in the shearing surface, cracks easily may occur. Therefore, by reducing the tensile stress remaining in at least part of the shearing surface of the weld or heat affected zone, it is possible to suppress the generation and hydrogen embrittlement cracks of cracks in shearing surface. [0016] 　Then, the present inventors have found that a protruding portion protruding from the punch provided, by inserting the protruding portion into at least a portion of the region of the weld or heat affected zone of the prior to the workpiece to the flat portion When shearing the workpiece it has been found to be able to effectively suppress the generation of cracks generation and hydrogen embrittlement cracks. For cutting method according to a press die for accomplishing this will be described below. [0017] (First Embodiment) 　Hereinafter, a first embodiment will be described with reference to the drawings. [0018] 　Figure 1 is a diagram showing a cutting apparatus 10 for carrying out the cutting method according to a press die according to the present embodiment. Figure 2 shows a front of the cutting device 10 shown in FIG. 1, FIG. 3 shows a side view of cutting apparatus 10 shown in FIG. Further, FIG. 4 shows a top of the cutting device 10 shown in FIG. 1, FIG. 5 shows the front of the punch 24. In the drawings, X-axis, Y-axis, and Z axis shows the three axes perpendicular to each other. [0019] 　Cutting device 10, as shown in FIGS. 1 to 5, for example, a device for cutting by shearing a plate-shaped workpiece 12 between the punch 24 and the die 20. The details of the configuration of a cutting device 10, for convenience of explanation, will be described later. Workpiece 12 to be blown object, as shown for example in FIG. 2, the first metal plate 14 which is formed in a plate shape and a second metal plate 16 are joined by welding at a portion butt rolling a metal plate. The first metal plate 14 is abutting portion and the portion between the second metal plate 16, the weld 18 is formed. Around the weld 18 (Y-direction on both sides of the weld 18), the heat-affected zone 30, 32 are formed. The detailed structure of the weld 18 and the heat-affected zone 30, 32 for convenience of explanation, will be described later. 　The welded parts butt can be used, for example, arc welding fusion welding, the welding of the resistance welding including upset welding and flash welding. [0020] 　The workpiece 12 is butt not limited to the welding portion, for example, the first metal plate 14 and the second metal plate 16 is a metal plate which is joined by various joining methods such mash seam welding and FSW it may be. 　Further, the first metal plate 14 regardless of the welding method and the second metal plate 16, be a metal plate of the same type may be a metal plate different. Tailored well Secluded blank a metal plate heterologous were joined by welding: In (TWB Tailored Welded Blanks), the press material adapted to the purpose of strength and rust prevention. [0021] 　The material of the workpiece 12 is not limited to steel, for example, iron, copper, zinc, tin, aluminum, titanium, magnesium, or include an alloy to them groups. Thickness T12 of the workpiece 12 may be any shearing is thick as possible, but are not limited to a particular thickness. The thickness may be different between the first metal plate 14 and the second metal plate 16. [0022] 　In the shearing of the cold, from the viewpoint of maintaining the dimensional accuracy of the product, the thickness T12 of the workpiece 12 is preferably 6.0mm or less. In particular, if the dimensional accuracy of the product is required high, the thickness T12 of the workpiece 12, more preferably 3.0mm or less. 　Meanwhile, since the joining by welding to the thickness dimension T12 of the workpiece 12 is too small to become unstable, the thickness T12 of the workpiece 12 is preferably 0.1mm or more. Further, the thickness T12 is more preferably 0.5mm or more. [0023] 　The workpiece 12 is, for example automobiles, household appliances, architectural structures, ships, bridges, construction machinery, used in various plants and the like. [0024] 　Also, as this workpiece 12, after the shearing of the punched or piercing by press, subject to hole expansion processing or flange up processing of the shear section, and a cold-rolled sheet. [0025] 　As shown in FIG. 6, the workpiece 12, and the welded portion 18 and the heat-affected zone 30, 32 previously described is formed. The weld 18 is a portion where the first metal plate 14 which is melted and the second metal plate 16 has solidified again. HAZ (heat-affected zone) 30,32 of the workpiece 12 and, by heat applied at the time of weld 18 is formed, but did not melt-textured, and (冶) gold properties refers to such a change has occurred partially mechanical properties (JIS standard welding terms (see JIS Z 3001 No. 11202)). [0026] 　For convenience of explanation in the present embodiment, the heat-affected zone of the first metal plate 14 which is one side S1 of the welded portion 18 and the first heat-affected zone 30, the heat affected zone of the second metal plate 16 which is the other side S2 a and the second heat-affected zone 32. [0027] 　In this workpiece 12, the coordinates of the edge 12A of the Y-axis direction of one S1 and X0, the distance from X0 to the first boundary line 34 between the first heat-affected zone 30 and the welding portion 18 to X1. Further, the distance between the weld portion 18 from X0 to the second boundary line 36 between the second heat-affected zone 32 and X2. [0028] 　Next, the detailed configuration of the cutting device 10. Cutting device 10, as shown in FIGS. 1 to 4 for example, a rectangular parallelepiped shape of the die 20. On the upper surface of the die 20, the workpiece 12 is placed. At the top of the die 20, the stopper 22 is arranged. The stopper 22 is also formed in substantially the same rectangular shape as the die 20. Stopper 22 includes a front surface 20A front 22A of the die 20 is the surface of the Z-axis direction, are arranged so as to be positioned on the same plane in the Z-axis direction. The stopper 22 is, for example, be vertically by an elevator mechanism (not shown), and fixing the pressing from above the workpiece 12 set on the upper surface of the die 20. [0029] 　The front 22A side of the stopper 22, the punch 24 is provided. Punch 24 is formed in a rectangular shape, the width dimension in the Y-axis direction is set to the width substantially the same dimensions of the stopper 22 and the die 20. The punch 24 is driven by a drive mechanism (not shown) in the vertical direction is the X-axis direction along the front surface 20A of the front 22A and die 20 of the stopper 22. Thus the punch 24, in a state where the workpiece 12 is sandwiched between the die 20 and the stopper 22, the extended portion of the workpiece 12 extending from the die 20, and the shear between the punch 24 and the die 20 It is configured to be cut. [0030] 　X-axis direction lower surface of the punch 24, as shown in FIG. 5, is formed to be flat. The flat lower surface a flat section 26. The center in the width direction is the Y-axis direction of the flat portion 26 (shown with a punch center line PC 7 in this embodiment), the protruding portion 28 that protrudes toward the workpiece 12 side. The workpiece 12, for example, as shown in FIGS. 7 and 8, is disposed in the X-axis direction downward with respect to the flat portion 26, is set on the die 20 to be described later. As shown in FIG. 8, the projecting portion 28 is formed in a ridge that extends in the longitudinal direction is the Z-axis direction. Incidentally, the protrusion 28 may be provided in plurality on punch 24. [0031] 　The projection 28 is, for example, as shown in FIG. 7, the X-axis direction upper and a flat portion 26 side of the base end Xa, the width dimension in the Y-axis direction toward the projection direction is the X-axis direction downward from Xc W28 'is formed on the narrower becomes wedge-shaped. That is, the projecting portion 28 decreases as the cross-sectional area toward the edge portion 28A of the tip from the base end portion of the flat portion 26 side when cut in a direction perpendicular to the moving direction of the punch 24 (X-axis direction) . [0032] 　Here, the wedge-shaped, thick end, refers to a blade shape becomes thinner toward the other end. In this embodiment, the cutting edge of the blade-shaped may be flat also be pointed. [0033] 　Protrusions 28 formed in a wedge shape, has one surface 28B which forms one side Y-axis direction, and a second surface 28C for forming the other side. One surface 28B and the other surface 28C is formed of a flat surface, toward the flat portion 26 to the distal portion Xb side is inclined to the punch center line PC. Here, "punch center line PC" passes through the center of the Y-axis direction of the punch 24 is a virtual line extending in the X-axis direction. The "tip Xb" is a portion of the Y-axis direction center of the cutting edge portion 28A, is positioned on the punch center line PC. One surface 28B and the other surface 28C is connected via a flat edge portion 28A at the distal end Xb side of the projection 28. [0034] 　The front end surface 28D of the projecting portion 28, as shown in FIG. 8, for example, are formed continuously in the X-axis direction below the front 24A of the punch 24. The front end face 28D is viewed from the Z-axis direction, is an isosceles triangle shape that protrudes toward the X-axis direction downward (see FIG. 7). Similarly, the rear end surface 28E of the protruding portions 28 are formed continuously on the surface 24B after the punch 24. The shape viewed from the Z-axis direction is an isosceles triangle shape that protrudes toward the X-axis direction downwards. [0035] 　Protrusions 28 need only protrude a little into the X-axis direction downward from the flat portion 26. With such an arrangement, prior to cutting of the workpiece 12 by the flat portion 26 as will be described later, cutting of the workpiece 12 is started by the projection 28. The present invention is by having such a configuration, it is possible to obtain the residual stress reduction effect of the shearing surface. [0036] 　To obtain further residual stress reduction effect of the shearing surface, for example, as shown in FIG. 7, a projecting dimension H of the protruding portion 28 from the flat portion 26, the thickness of the workpiece 12 to be blown object T12 is preferably not less than 10% (see FIG. 6). It is more preferable that the protrusion dimension H and more than 50% of the thickness T12 of the workpiece 12. [0037] 　Incidentally, the protrusion dimension H is, the more residual stress reduction effect of the shearing surface is obtained larger, when the punch 24 is in the raised position, for convenience of preventing interference with the workpiece 12 to be set, the upper limit It is naturally limited. [0038] 　Further, in order to prevent the loss of the cutting edge portion 28A is preferably the following condition is satisfied. That is, the angle α formed between the one surface 28B and the other surface 28C of the projection 28 is preferably not less than 10 degrees. Is less than 10 degrees and stress is concentrated on the edge portion 28A, there is a possibility of defects of the cutting edge portion 28A. [0039] 　The angle α is preferably set to be lower than or equal to 170 degrees from the plane to concentrate shear stress, and more preferably not more than 120 degrees. Furthermore, the angle α, it is more preferably equal to or less than 80 degrees. [0040] 　Positional relationship between the workpiece 12 and the projecting portion 28, and the width dimension W28 of the inter-proximal portion Xa and a proximal end Xc in the flat portion 26 side of the projection 28, as shown below, and those specified to. [0041] 　When shearing the tip Xb in contact with the Y-axis direction center of the weld zone 18, by the following conditions positional relationship between the workpiece 12 and the projecting portion 28, the residual stress reduction effect of the shearing surface it can be obtained in the weld 18 and the heat-affected zone 30, 32. [0042] 　Determined based on the width dimension W18 of the welded portion 18 is the width dimension W28. First, as shown in FIG. 7, one surface 28B and the flat portion 26 intersect each other base end portion Xa of the projection 28 and the first base end portion Xa, and the other surface 28C and the flat portion 26 of the projection 28 the base end portion Xc mutually intersecting a second proximal portion Xc. Further, the distance from the first proximal end Xa to the punch center line PC to the first width W1, the distance from the second proximal end Xc to the punch center line PC and second width W2. The this first width W1 width obtained by adding the second width W2 and the width W28. Width W28 in the present embodiment, and be greater than the width dimension W18 of the welded portion 18 shown in FIG. 6, for example (W28 = (W1 + W2)> W18). [0043] 　Here, maintaining the end surface properties of shear plane other than the weld 18, in order to obtain the residual stress reduction effect of the shearing surface, alpha <170 degrees and, W28 = (W1 + W2) <5 × T12 (workpiece it is desirable to set a range of a thickness dimension T12) of 12. More preferably alpha <120 degrees and sets W28 = (W1 + W2) <5 × T12 width W28 at the base end of the projection 28 within an amount of (the thickness T12 of the workpiece 12). [0044] 　Cutting edge 28A of wedge-shaped, as shown in FIG. 7 for example, it is formed to be flat. Surface viewed this cutting edge 28A from the X-axis direction lower side is rectangular. When the tip of the cutting edge portion 28A is at an acute angle, there is a risk of damage caused chipping by stress is concentrated on the cutting edge portion 28A. Therefore, by a flat cutting edge portion 28A, it can be protected punch 24 to prevent breakage of the cutting edge portion 28A. [0045] 　Y-axis direction width dimension H28 of the cutting edge portion 28A is preferably 1% or more of the thickness T12 of the workpiece 12 (see FIG. 6). By width H28 is 1% or more of the thickness dimension T12, excessive stress concentration on the edge portion 28A is prevented. Therefore, it is possible to prevent breakage of the cutting edge portion 28A. The width dimension W28 at the proximal end of the projection 28 is preferably smaller than the total width of the width dimension W18 and the width W30 and the width W32. By width W28 is such a value, the projection 28 during the shearing of the workpiece 12, do not overlap in the width direction all the regions of the welded portion 18 and the heat affected zone 30 and 32. Therefore, it is possible to reliably obtain at least one of the regions in the weld 18 and the heat-affected zone 30, 32 the residual stress reduction effect at a shear plane. [0046] 　The shape of the cutting edge portion 28A of the projecting portion 28 may be a curved shape (R shape) as described below with reference to FIGS. 15 and 16. Preventing stress concentration by the curved shape of the cutting edge 28A, it is possible to prevent breakage of the cutting edge portion 28A. [0047] 　Then, for example, as shown in FIG. 8, the clearance 38 forming a gap between the front 20A of the surface 24B and the die 20 after the punch 24 is 0.5% or more the thickness dimension T12 of the street workpiece 12 shown below preferably 25% or less dimensions. [0048] 　Clearance 38 is less than 0.5% of the thickness T12 of the workpiece 12, there is a possibility that chipping damage caused to the tip portion of the protruding portion 28, the clearance 38, the thickness of the workpiece 12 it is preferable that the T12 0.5% or more. This clearance 38 is more preferably 1.0% or more. [0049] 　On the other hand, the clearance 38 is more than 25% of the thickness T12 of the workpiece 12, the greater the curvature of the workpiece 12, the burr is likely to occur. Therefore, the clearance 38 is 25% or less of the thickness T12 of the workpiece 12. This clearance 38 is more preferably 15% or less. [0050] 　In practicing the cutting method according to a press die according to the present embodiment with reference to the cutting device 10, set the workpiece 12 on the upper surface 20B of the die 20, the workpiece 12 in the Z-axis direction slide to adjust the shearing position with protruding shear portions from the die 20 to the front edge 20C of the die 20 (setting step). [0051] 　At this time, first as shown in FIG. 9A, first proximal end Xa is the first metal plate 14 side than the boundary 32A between the second heat-affected zone 32 and the general portion 16A of the second metal plate 16 of the protrusion 28 so as to be positioned to position the workpiece 12 relative to the punch 24. The "General portion" in the present embodiment is shown of the workpiece 12, the portion that is not affected by welding, namely the Y-axis direction outside portion of the heat-affected zone. Thus, prior to cutting of the workpiece 12 by the flat portion 26 of the punch 24, the projection 28, at least one of the cleavage of at least the welding portions 18 and the heat-affected zone 30, 32 of the workpiece 12 is started that. Incidentally, the "start of disconnection" in this embodiment means the contact between the punch 24 and the workpiece 12 (the occurrence of sagging). 　Similarly, as shown in FIG. 9B, as the second proximal portion Xc of the punch 24 is positioned on the side of the second metal plate 16 than the boundary 30A between the first heat-affected zone 30 and the general portion 14A, the the workpiece 12 is positioned relative to the punch 24. That is, by positioning the workpiece 12 as one of the first proximal portion Xa or second base portion Xc is positioned within a range from the boundary 30A of the workpiece 12 in the boundary 32A with respect to the punch 24 Bayoi. [0052] 　Here, if the combination of the material of the workpiece 12 has a plurality of formed by welding under the same conditions the same metal plates 14 and 16 respectively, the width of the welded portion 18 and the heat-affected zone 30, 32 is different the It is found to be substantially the same dimension between the workpiece 12. [0053] 　Thus, in a standard sample of workpiece 12 to be blown object, the position and width in the Y-axis direction of the welded portion 18 and the heat-affected zone 30, 32 may be previously measured. Then, to align the Y-axis direction of the workpiece 12 and the projecting portion 28 of the punch 24 with the measurement results. [0054] 　In this positioned state, by operating the drive mechanism lowers the punch 24 to move relative to the punch 24 relative to the die 20. Then, cutting and shearing the workpiece 12 so as to cross the weld 18 in the workpiece 12 (cutting step). It is also possible to move the die 20 relative to the punch 24. [0055] 　In the cutting step, the cutting edge portion 28A of the projecting portion 28 comes in contact with the workpiece 12 fixed die 20 and the stopper 22. At this time, by the workpiece 12 is positioned to one of the previously first proximal portion Xa or second base portion Xc is located between the boundary 30A of the workpiece 12 in the boundary 32A When the punch 24 is lowered, the protruding portion 28 is inserted into at least one place of the heat-affected zone 30, 32 and welds 18. The protrusion 28 will shear the workpiece 12 while applying a stress to at least one place of the heat-affected zone 30, 32 and welds 18. At this time, since the stress in the cutting edge portion 28A of the projection 28 is concentrated, the cutting edge portion 28A is gradually inserted into the workpiece 12 while applying pressure to the workpiece 12 in the X-axis direction downwards. Region in contact with the projecting portion 28 of the workpiece 12, although being sheared by stresses acting through the protruding portion 28 to the X-axis direction lower side, in the peripheral portion to be the sheared, a limited stress acting cage, plastic deformation is small. Therefore, the area sheared projection 28 of the workpiece 12, the shearing proceeds while being constrained by the workpiece 12 in the periphery thereof. Therefore, in the region in contact with the protruding portion 28, an enlarged shear plane area for the production of ductile fracture cracks it is delayed, the tensile residual stress is reduced. Thus, prior to cutting of the workpiece 12 by the flat portion 26 of the punch 24, the projection 28 will shear the workpiece 12. [0056] 　Then, the flat portion 26 along with the descent of the punch 24 abuts on the workpiece 12, to press the workpiece 12. Thus, the workpiece 12, with curved distorted downward by stress generated by the press, is cut sheared action of the flat portion 26 and the die 20 of the punch 24 in a curved state. [0057] 　At this time, a portion of the workpiece 12 is sheared by the projection 28 prior to the workpiece 12 across the cutting by the flat portion 26, shear plane area is enlarged. Therefore, considerably as compared with the case of cutting the workpiece 12 only at the flat portion 26 of the punch 24, during shearing, tensile stress remaining in at least one place of the heat-affected zone 30, 32 and welds 18 it can be reduced to. As a result, the shearing surface after shearing, it is possible to suppress the occurrence of occurrence and fatigue cracking of hydrogen embrittlement cracks. [0058] 　Thus, for example, steel sheets and high strength residual stress tends to increase the shearing surface of more than 1000 MPa, even tailored well Secluded blank (TWB), making it possible to suppress the generation of occurrence and fatigue cracking of hydrogen embrittlement cracks it can. [0059] 　Further, for example, equal clearance 38 between the punch 24 and the die 20 is, for example 10% or more, even if relatively large, tensile properties, fatigue properties, and forms a good shearing surface hydrogen embrittlement resistance be able to. [0060] 　Here, the width W28 at the proximal end of the projection portion 28 is set larger than the width W18 of the welded portion 18. Thus, for example, as shown in FIG. 10, the first heat-affected zone 30 at least a portion adjacent to the weld 18 and weld 18 at the projection 28 prior to cutting of the workpiece 12 by the flat portions 26 and it can be cut and at least a portion of the second heat-affected zone 32. Thus, welds 18, the first heat-affected zone 30, and residual tensile stress in the shearing surface can be reduced in the second heat-affected zone 32, the generation and development of fatigue cracks in hydrogen embrittlement cracks it can be effectively suppressed. [0061] 　Incidentally, if the prior to cutting to cleavage by welds 18 or 1 HAZ 30 or protrusion 28 is a flat portion 26 at least a portion of one of the second heat-affected zone 32, the residual stress of the shearing surface can be reduced, it is possible to suppress the occurrence of occurrence and fatigue cracking of hydrogen embrittlement cracks. [0062] 　For example, as shown in FIG. 11, the cutting edge portion 28A the center of the projecting portion 28, to position the workpiece 12 so that the second boundary line 36 between the welds 18 and the second heat-affected zone 32 coincides if put can be sheared prior reliably and weld 18 and the second heat-affected zone 32. Thus, it is possible to suppress the occurrence of fatigue cracks in the second boundary line 36 to reduce the residual stress in the shearing plane. [0063] 　For example, as shown in FIG. 12, if sheared prior to cleavage by the flat portion 26 a part of the projection 28 of the punch 24, for example, the second heat-affected zone 32, the shearing surface, the second heat affected residual stress in the part 32 can suppress the generation of reduced fatigue crack. [0064] 　The projecting dimension H of the protruding portion 28 from the flat portion 26 is 50% or more of the thickness T12 of the workpiece 12 to be blown object. This increases the effect of the shear in the projection 28. [0065] 　In the second to eighth embodiments to be described in this embodiment and the following, but the protruding dimension H was more than 50% of the thickness T12, if the projecting dimension H is 10% or more of the thickness dimension T12 , resulting residual stress reduction effect of the shearing plane by the projection 28. [0066] 　The angle α formed between the one surface 28B and the other surface 28C of the projection 28, which is 10 degrees or more, defects of the cutting edge portion 28A is prevented. Further, the angle α is at least 10 degrees 80 degrees or less. Thus, while suppressing the loss of the cutting edge portion 28A, it is possible to ensure the width dimension W28 at the base end of the projection 28. [0067] 　In the second to eighth embodiments to be described in this embodiment and the following, but the angle α was set to 10 to 80 degrees, but it is not limited thereto. For example, the upper limit of the angle α is, or less 120 degrees, or can be less 170 degrees. [0068] 　Further, in the second to eighth embodiments to be described in this embodiment and the following, by the projection 28 and the wedge shape, although easy insertion into the workpiece 12 of the cutting edge portion 28A, the It is not limited to the shape. For example it can be a rectangular projection 28 to obtain the residual stress reduction effect of the shearing surface. [0069] (Second Embodiment) 　FIG. 13 is a diagram showing a second embodiment of the present disclosure, the same or equivalent parts as in the first embodiment, the description thereof will be omitted with denoted by the same reference numerals, the different parts only it is described. [0070] 　That is, in this embodiment, is different from the shape of the projection 28 of the first embodiment. Projection 28 according to this embodiment, the flat one surface 28B and the flat portion 26 is first width W1 of the first base end portion Xa which intersect each other to the punch center line PC, and the other surface 28C from the punch center line PC parts 26 and is set to be shorter than the second width W2 to the second proximal end Xc mutually intersecting (W1