Technical field
[0001]
　The present invention, automotive, household appliances, architectural structures, ships, bridges, construction machinery, various plants, when manufacturing by shearing the metal member used in the penstock and the like, to form a shearing surface of the superior surface properties on shear processing method.
Background technique
[0002]
　Automobiles, home appliances, architectural structures, ships, bridges, construction machinery, various plants, the production of the metal member used in the penstock, etc., shearing is widely utilized. Figure 1 shows an embodiment of a shearing schematically. In FIG. 1 (a), the mode of shearing for forming a hole in the workpiece shown schematically in FIG. 1 (b), shows schematically an embodiment of a shearing to form an open cross section on a workpiece .
[0003]
　In the shearing shown in FIG. 1 (a), the workpiece 1 is placed on the die 3, the punch 2 downward 2a, i.e. is pushed in the thickness direction of the workpiece 1, the workpiece 1 to form a hole in. In the shearing shown in FIG. 1 (b), the workpiece 1 is placed on the die 3, as well, the punch 2 downward 2a, i.e. is pushed in the thickness direction of the workpiece 1, the workpiece the opening section is formed on the timber 1.
[0004]
　Shearing surface 9 of the workpiece 10 which is formed by shearing is generally as shown in FIG. 2, sagging 4, constituted by the shear surface 5, fracture surface 6, and burr 7. Sagging 4, by the workpiece 1 is pressed by a punch, it is formed on the upper surface 8a of the workpiece 10. Shear plane 5 by the workpiece 1 is drawn into the gap between the punch and the die, the workpiece 1 is formed by locally stretched. Fracture surface 6, the workpiece 1 is formed by broken drawn into the gap of the punch and the die. Burr 7, when the workpiece 1 that is drawn into the gap between the punch and the die is separated from the workpiece 10 to rupture occurs on the lower surface 8b of the workpiece 10.
[0005]
　Shearing surface is generally inferior surface properties compared to the machined surface to form by machining, for example, a low hydrogen embrittlement resistance, low fatigue strength, or stretch flange crack (by pressing after shearing, shearing cracking occurring on the processed surface) is having a problem easily occurs. In particular, in a high-tensile steel plate, decrease in hydrogen embrittlement cracking and the fatigue strength due to residual tensile stress is likely to occur.
[0006]
　Techniques attempt to resolve the problems of shearing surfaces have been proposed, but these techniques generally by devising the structure of the punch and the die, fatigue strength, the stretch flangeability and the like, the surface properties of the shearing surface shall improve (e.g., see Patent documents 1-3), the shearing surface is subjected to a processing such as coining or shaving, embrittlement resistance, such as fatigue strength, surface property of the shearing surface which improve (e.g., see Patent documents 4-8) can be divided into.
[0007]
　However, in the technique by devising the structure of the punch and the die, there is a limit in improving the surface properties of the shearing surface, also, in the technique which processes the shearing surface, one step more min, productivity decreases , production cost is increased.
CITATION
Patent Document
[0008]
Patent Document 1: Laid-Open Patent Publication No. 2009-051001
Patent Document 2: Laid-Open Patent Publication No. 2014-231094
Patent Document 3: Laid-Open Patent Publication No. 2010-036195
Patent Document 4: Laid-Open Patent Publication No. 2008-018481
Patent Document 5: Laid-Open Publication No. 2011-218373
Patent Document 6: Laid-open Patent Publication No. 2006-082099
Patent Document 7: JP Laid-open No. 2002-263748
Patent Document 8: Japanese Patent Application Publication No. 3-207532
Summary of the Invention
Problems that the Invention is to Solve
[0009]
　In view of the state of shear processing techniques, the metal member having excellent shearing surface embrittlement resistance and fatigue strength, good productivity, and that can be manufactured at low cost, shearing an object of the present invention to provide a method.
Means for Solving the Problems
[0010]
　The present inventors have intensively studied a technique for solving the above problems, the shearing of the metal member such as a high tensile steel, in terms of resistance to hydrogen embrittlement resistance, the clearance between the punch and the die (gap) is small Although it is better to, it is difficult to produce accurately clearance small molds, and a large cost can take the production of molds, the clearance between the punch and the die is small, damage of the mold is likely to occur, especially in shearing of the high-tensile steel plate to obtain a knowledge that the damaging of the mold is unavoidable.
[0011]
　The present inventors have further made intensive studies, as a result, the distance between the die and the punch, and set to shearing 5 to 80% of the thickness of the workpiece, by utilizing vent material punched out by the punch, by pressing the end face of the punching member to shearing surface of the workpiece on the die, a metal member having excellent shearing surface embrittlement resistance and fatigue strength, good productivity, and can be produced at low cost It was found.
[0012]
　The present invention has been made based on the above findings, its gist the following.
[0013]
　(1)
　a workpiece having a first surface and a second surface on the opposite side, so that the second surface is disposed on the die side, placed on the die, wherein the first workpiece the terms toward the second surface in the thickness direction of the workpiece, a shearing method of shearing a punch disposed on the first surface,
　and said punch (a) and the die vertical spacing in the thickness direction of the workpiece a distance, the distance setting step of 5% to 80% of the thickness of the workpiece,
　shearing the workpiece by (B) the punch processed to a shearing process for obtaining the punching member and the workpiece, each said vent material and processing material, a first surface and a second surface corresponding to the first and second surfaces of the workpiece having, shearing step, and
　(C) disposed on the second surface side of the workpiece so as to face the punch By a pushing punch, the punching member, while still unplugged, push the punched hole of the workpiece, steps, pressing pressing the end surface of the vent material shearing surface of the workpiece
　including, shear processing method.
　(2)
　In the above step (A), the interval is 10% to 80% of the said die and said punch, it said (1) shearing method according to claim.
　(3)
　In the above step (A), the interval is 10 to 30% of said die and said punch, said (1) shearing method according to claim.
　(4)
　in the step (C), the push of the punching member performs in the range where the second surface of the punching member is not past the first surface of the workpiece, to coining the shearing surface of the workpiece including, (1) shearing method according to any one of - (3).
　(5)
　in the step (C), the push of the punching member, the position of the second surface of the vent material, past the position of half of the thickness toward the first surface to the second surface of the workpiece performed with no range comprises coining the shearing surface of the workpiece, wherein (1) shearing method according to any one of - (3).
　(6)
　in the step (C), the push of the punching member, the position of the second surface of the vent material is performed so as to be the same as the position of the second surface of the workpiece, the shearing of the workpiece the working surface comprises coining said (1) shearing method according to any one of - (3).
　(7)
　in the step (C), the push of the punching member, the position of the second surface of the vent material is performed within a range not past the position of the second surface of the workpiece, shearing of the workpiece comprises coining at least a portion of the surface, the (1) shearing method according to any one of - (3).
　(8)
　in the step (C), said punching a vent pushed into the hole the punching member by the punch to repeat the indentation punch with the punching member said vent hole in one or more times to be pushed, the (1) - shearing method according to any one of (7).
　(9)
　the die, the punch, and the pushing punch, said outer peripheral trim the punch and the pushing punch on the outer peripheral side of the workpiece the die on the inner peripheral side of the are arranged and the workpiece is placed it has a type of construction,
　that at least one surface of the stamping surface and the pushing surface of the pushing punch of the punch has a convex portion, and
　wherein while fixing across the workpiece by the punch and the pushing punch ,, performing the shearing and the pressing
　including, shearing method according to any one of (1) to (8).
　(10)
　said die, said punch, and said pushing punch, said outer peripheral trim the punch and the pushing punch on the outer peripheral side of the workpiece the die on the inner peripheral side of the are arranged and the workpiece is placed having the type of structure,
　the further outer peripheral side of the punch, placing and coupling the additional punch to the punch,
　to further the outer peripheral side of the pushing punch, said additional punch across the workpiece as opposed, placing by connecting additional pushing punch the pushing punch,
　at least one surface of the stamping surface and the pushing surface of the additional pushing punch of said additional punch that has a convex portion, and
　the connecting blanked surface of the punch and the additional punch which is, as well as in pushing surface of the concatenated pushing punch and additional pushing punch, the object While fixed across the engineering material, to perform the shearing and the pressing,
　including, shearing method according to any one of (1) to (8).
　(11)
　said die, said punch, and said pushing punch, said outer peripheral trim the punch and the pushing punch on the outer peripheral side of the workpiece the die on the inner peripheral side of the are arranged and the workpiece is placed having the type of structure,
　the further outer peripheral side of the punch, place additional holder
　further outer peripheral side than the pushing punch, so as to face the additional holder across the workpiece, additional die it placing
　at least one surface of the fixed surface on which the faces the second surface of the workpiece fixing surface and the additional die facing the first surface of the workpiece of the additional holder having a projecting portion it, as well as
　a fixed surface and a fixed surface of the additional die of the additional holder, while the fixed across the workpiece, to perform the shearing and the pressing
　including, the Shearing method according to any one of 1) to (8).
　(12)
　said die, said punch, and said pushing punch, said outer peripheral trim the punch and the pushing punch on the outer peripheral side of the workpiece the die on the inner peripheral side of the are arranged and the workpiece is placed having the type of structure,
　the further outer peripheral side of the punch, placing the additional punch,
　said additional punch and said pushing punch, said obtaining the shearing to shear plane the workpiece, as well as
　the the shear plane was constrained by the side surface of the additional punch, the interval setting, the shearing, and to perform the pressing,
　including, (1) shearing method according to any one of - (8) .
　(13)
　said die, said punch, and said pushing punch, said outer peripheral trim the punch and the pushing punch on the outer peripheral side of the workpiece the die on the inner peripheral side of the are arranged and the workpiece is placed it has a type of construction,
　the more outer peripheral side than the pushing punch, placing the additional die,
　between the additional die and the punch, the workpiece to obtain the shearing to shear plane, and
　wherein the shear plane, and restrained by the side surface of the additional die, the interval setting, the shearing, and that, to perform the pressing
　including, shearing of any one of (1) to (8) Method.
　(14)
　said die, said punch, and said pushing punch, said outer peripheral trim the punch and the pushing punch on the outer peripheral side of the workpiece the die on the inner peripheral side of the are arranged and the workpiece is placed having the type of structure,
　the further outer peripheral side of the punch, placing the additional holder,
　in further the outer peripheral side of the push punch, so as to face the additional holder across the workpiece, additional it placing die
　between the punch and the additional die, said obtaining the shearing to shear plane the workpiece, and
　the shear plane, and restrained by the side surface of the additional die or additional holder, the distance setting the shearing, and to perform the pressing,
　including, shearing method according to any one of (1) to (8).
　(15)
　the workpiece is a metal plate having a 340MPa class or higher tensile strength, wherein (1) to shearing method according to any one of (14).
　(16)
　the workpiece is a metal plate having a 980MPa class or higher tensile strength, wherein (1) to shearing method according to any one of (14).
　(17)
　the workpiece is steel, the (15) or (16) shearing method according to claim.
Effect of the Invention
[0014]
　According to the present invention, the shearing of the metal member, a metal member having excellent shearing surface embrittlement resistance and fatigue strength, good productivity, and can be manufactured at low cost.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015]
[1] Figure 1 (a) is a cross-sectional schematic view showing an aspect of the shearing to form a hole in the workpiece. Figure 1 (b) is a cross-sectional schematic view showing an aspect of the shearing to form an open cross-section on the workpiece.
FIG. 2 is a cross-sectional schematic view of a shearing surface of the workpiece.
FIG. 3 is a cross-sectional schematic view showing an aspect of arranging the workpiece in the shearing machine.
[4] FIG. 4 is a cross-sectional schematic view showing an aspect of fixing the workpiece to the shearing machine.
FIG. 5 is push the punch is a cross-sectional schematic view showing an aspect that shearing the workpiece.
FIG. 6 is further pushed the punch is a cross-sectional schematic view showing an aspect that shearing the workpiece.
FIG. 7 is a vent material punched out by the punch, it pushed back while still unplugged is a cross-sectional schematic view showing an aspect of pressing the end face of the punching member to shearing surface of the workpiece.
[8] FIG. 8 (a) is a cross-sectional schematic view of a distance setting step. 8 (b) is a cross-sectional schematic view of a shearing process. 8 (c) is a cross-sectional schematic view of a pressing process.
[9] FIG. 9 (a) is a cross-sectional schematic view showing a state at the start pressing the end face of the vent member and the shearing surface of the workpiece. 9 (b) is a schematic cross-sectional views showing a plastic deformation area at the time of pressing the completion of the end face of the vent member and the shearing surface of the workpiece.
[10] FIG 10 is a cross-sectional schematic view showing an aspect of arranging the workpiece cantilevered shearing machine.
[11] FIG 11 is a cross-sectional schematic view showing an aspect of fixing the workpiece cantilevered shearing machine.
[12] Figure 12 push the punch is a cross-sectional schematic view showing an aspect that shearing the workpiece.
FIG. 13 is a vent material punched out by the punch, it pushed back while still unplugged is a cross-sectional schematic view showing an aspect of pressing the end face of the punching member to shearing surface of the workpiece.
[14] FIG 14 is a schematic sectional view illustrating a first embodiment of the peripheral trim.
[15] FIG 15 is a schematic sectional view illustrating a second embodiment of the peripheral trim.
[16] FIG 16 is a schematic sectional view illustrating a third embodiment of the peripheral trim.
[17] Figures 17 (a) and 17 (b) is a schematic sectional view illustrating a fourth embodiment of the peripheral trim.
[18] FIG. 18 (a) and 18 (b) is a schematic cross-sectional view illustrating a fifth embodiment of the peripheral trim.
[19] FIGS. 19 (a) and 19 19 (b) is a schematic cross-sectional view illustrating a sixth embodiment of the peripheral trim.
[20] FIG. 20 (a), the interval between the die and the punch is a cross-sectional photograph of shearing plane when 5% of the thickness of the workpiece. FIG. 20 (b), the interval between the die and the punch is a cross-sectional photograph of shearing surface of the case of 10% of the thickness of the workpiece.
[21] FIG. 21 (a), the interval of the die (D) and the punch (P) is a cross-sectional photograph of shearing surface of the case of 20% of the thickness of the workpiece. FIG. 21 (b), the interval of the die (D) and the punch (P) is a cross-sectional photograph of shearing surface of the case of 30% of the thickness of the workpiece. FIG. 21 (c) spacing the die (D) and the punch (P) is a cross-sectional photograph of shearing surface of the case of 40% of the thickness of the workpiece.
[22] FIG 22 is a schematic view showing a measurement position of the residual stress in the shearing plane.
FIG. 23, the interval of the die and the punch is a graph showing the tensile residual stress in the shearing plane when 1% of the plate thickness of the workpiece.
FIG. 24, the interval of the die and the punch is a graph showing the tensile residual stress in the shearing surface when 5% of the thickness of the workpiece.
FIG. 25, the interval of the die and the punch is a graph showing the tensile residual stress in the shearing surface when 10% of the thickness of the workpiece.
FIG. 26, the interval of the die and the punch is a graph showing the tensile residual stress in the shearing surface when 20% of the thickness of the workpiece.
FIG. 27, the interval of the die and the punch is a graph showing the tensile residual stress in the shearing surface when 30% of the thickness of the workpiece.
FIG. 28, the interval of the die and the punch is a graph showing the tensile residual stress in the shearing surface when 40% of the thickness of the workpiece.
FIG. 29, the interval of the die and the punch is a graph showing the tensile residual stress in the shearing surface of the 60% of the thickness of the workpiece.
FIG. 30 is a graph showing the residual stress reduction effect tensile by spacing the die and punch.
FIG. 31, according to the interval of the die and the punch is a graph representing the angle θ of the fracture surface of the workpiece with respect to the traveling direction of the punch.
FIG. 32 is due to the angle of the fracture surface theta, a graph showing the tensile residual stress reduction effect.
[33] FIG 33 is a graph showing the fatigue characteristics measured by flat bending fatigue test.
[34] FIG 34 is a cross-sectional schematic view showing the stretch flangeability of the test method.
[35] FIG 35 is a graph showing the test results for the stretch flangeability of the shearing surface of the workpiece.
DESCRIPTION OF THE INVENTION
[0016]
　Shear processing method of the present disclosure, the shearing method of shearing the workpiece in a die and a punch, the gap between the die and the punch performs a shearing (hereinafter also referred to as clearance) as above specified range, the resulting the vent material, the shearing plane as a basic concept to be used as a tool for finishing line, after shearing, and wherein the pressing the end face of the punching member to shearing surface of the workpiece. In the present application, the workpiece is a metal member.
[0017]
　According to the method of the present disclosure, it is possible to increase the distance between the die and punch. Therefore, without high dimensional accuracy, such as precision shearing is required, the mold can be manufactured at low cost, in addition, damage to the mold is prevented, damage of the mold in particular in shearing of high-tensile steel plate is prevented, it increases productivity because the need for repair and adjustment of the mold is reduced. Furthermore, according to the method of the present disclosure, the state where the vent material punched by shearing, punched, and used as a tool for finishing line a shearing surface, after shearing, machining an end face of the punching member against the shearing surface of the wood. Therefore, it is not necessary to re-install the vent material into another mold after punching, it is possible to reduce the number of steps than the prior art. Moreover, there is no need to re-install the vent material into another mold after punching, does not occur positional deviation of the punching member, it is possible to reliably press the end surface of the punching member to shearing surface of the workpiece. Therefore, according to the method of the present disclosure, the steel having excellent shearing surface embrittlement resistance and fatigue strength, good productivity, and can be manufactured at low cost.
[0018]
　The disclosed method, in order to set a large distance between the die and the punch, the precision shearing of the so-called fine blanking or the like are clearly distinguished. Note that the precision shearing in the plate punching, and minimize the clearance, the entire cutting surface, a method of constructing a shear plane.
[0019]
　Hereinafter, a method of the present disclosure will be described with reference to the drawings.
[0020]
　In FIGS. 3 to 7, after obtaining the processed material and punching material by shearing the workpiece at a shear machine, raises the punch, pushed back the vent material while still unplugged, punching of the workpiece shows an example embodiment pushed into the hole.
[0021]
　3, the shearing machine 100 that may be used in the methods of the present disclosure, showing a cross-sectional schematic view of an embodiment of arranging the workpiece 14 having a first surface 141 and second surface 142 opposite it. Figure 4 shows a cross-sectional schematic view of an embodiment of a fixed workpiece 14 to shear machine 100. Figure 5, a punch 17 is moved from the first surface 141 of the workpiece 14 in the thickness direction toward the second surface 142, it shows a cross-sectional schematic view of the course of the mode of shearing the workpiece 14. 6, further moving the punch 17 is a schematic cross-sectional view of the embodiments shearing the workpiece 14. Figure 7 shows the vent material 18 punched out by a punch, it pushed back while still unplugged, the cross-sectional schematic view of the embodiment pushed into drain hole 18a.
[0022]
　As shown in FIG. 3, placing the workpiece 14 in the shearing machine 100. Shearing machine 100 preferably comprises a pushing punch 13 held by the elastic member 11. Pushing the punch 13 held by the elastic member 11 is protruded by ΔH from the surface 121 of the die 12 in contact with the second surface 142 of the workpiece 14. ΔH can be varied depending on the amount pushed back vent material. ΔH may be greater than the thickness of the workpiece, it may be the same as the thickness of the workpiece, or may be zero. Further, pushing the punch 13 may be recessed from the surface 121 of the die 12, but the amount of retraction than the thickness of the workpiece is small. That, [Delta] H is may be negative, the magnitude (absolute value) is less than the plate thickness. For example, if greater than the thickness of the workpiece to [Delta] H, in pushing back the vent material, let through the piercing to vent material, if the [Delta] H to zero, to return to the original position of the piercing of the vent member can. After placing the workpiece 14 in the shearing machine 100, as shown in FIG. 4, to press the holder 15 by the elastic member 16, to secure the workpiece 14 to the die 12.
[0023]
　Next, as shown in FIG. 5, in a state of fixing the workpiece 14 into the die 12, the punch 17 toward the first surface 141 of the workpiece 14 on the second surface 142 is moved in the thickness direction, performing shearing of the workpiece 14. Moreover, by moving toward the punch 17 on the second surface 142, as shown in FIG. 6, formed with vent member 18, a workpiece 14a having a shearing surface 20 including a shear surface and fracture surface. Vent material 18 has a first surface 181 and second surface 182 corresponding to the first surface 141 and second surface 142 of the workpiece 14. Workpiece 14a has a first surface 14a-1 and the second surface 14a-2 corresponding to the first surface 141 and second surface 142 of the workpiece 14.
[0024]
　The movement of the plate thickness direction of the punch 17 towards the second surface 142 from the first surface 141 is preferably performed while applying a back pressure from pushing the punch 13. By moving the punch 17 while against the back pressure from pushing the punch 13, can be held in the vent member 18 more stably. Pushing the punch 13, after shearing, the punching member 18, pushed back in a state in which punching, as long as it can be pushed into the punched hole 18a, is not particularly limited. Means "punched remains" and "pulled as-state" same in the present application, the vent material 18 obtained by the shearing, without removing from the die, means a state in which intact. Pushing the punch 13, prior to placement of the workpiece 14, or even jump out from the surface 121 of the die 12 may not jump out. The driving method of the indentation punch 13, as long as it can drive the push punch 13, the method is not limited, and instead of the elastic member, for example, may be one operated by a gas cushion or a cam mechanism.
[0025]
　Next, as shown in FIG. 7, the pushing punch 13 is vent member 18, while still unplugged, push the punched hole 18a, the end surface 19 of the punching member 18, shearing is the contour surface of the drain hole 18a pressed against the surface 20. If pushing the punch 13 comprises a resilient member 11, by utilizing the repulsive force of the elastic member 11, pushing the punch 13 can be pushed into the hole 18a disconnect the vent material 18. Figure 7 is a second surface 182 of the punching member 18, before passing the position of the second surface 14a-2 of the workpiece 14a, shows an embodiment in which stop the pushing of the punching member 18.
[0026]
　Shearing surface 20 of the workpiece 14a, as shown in FIG. 2, sagging 4, shear plane 5 may be configured in a fracture surfaces 6 and burr 7. In the method of the present disclosure, the vent material 18, used as a tool for finishing line a shearing surface 20 of the workpiece 14a, pushed into the holes 18a disconnect the vent material 18, the holes 18a disconnect the end face 19 of the punching member 18 pressed against the shearing surface 20 is contoured surface. Thus, the tensile residual stress in the shearing surface 20 of the workpiece 14a can be reduced, preferably while reducing the tensile residual stress, the variation can be reduced. By reducing the tensile residual stress, it is possible to improve the hydrogen embrittlement resistance and fatigue strength.
[0027]
　FIG 8 (a) ~ (c), illustrates the method of the present disclosure, the interval setting step, shearing process, and an example schematic cross-sectional view of the pressing process.
[0028]
　The interval setting process shown in FIG. 8 (a), the distance d between the punch 17 and the die 12 is set in the range of 5 to 80% of the thickness t of the workpiece 14. Further, the workpiece 14 is fixed in the die 12 and the holder 15.
[0029]
　The shearing process shown in FIG. 8 (b), carried out shearing of the workpiece 14 with the punch 17, vent material 18 and the workpiece 14a is obtained. Angle of the punch angle 17a (front end of the punch 17) is preferably a right angle, the punch angle 17a may be any shape sheared extent possible, for example, have a rounded or chamfered portion good. Shearing surface of the workpiece 14a, as shown in FIG. 2, sagging 4, shear plane 5, fracture surface 6, and may be configured in a burr 7. The end face 19 of the vent member 18 is also sagging, shear plane may be configured fracture surface, and Bali. The shape of the end face 19 in the shape of shearing surface 20 of the workpiece 14a and the vent member 18, it is substantially symmetrical. In FIG. 8 (b), the the end face 19 of the shearing surfaces and vent member 18 of the workpiece 14a, schematically, only shear surface and fracture surface. Workpiece 14a dashed have a cross section 5 and fracture surfaces 6, fracture surface 6, the fracture surface 6a and the angle of the vent material 18 matches. Furthermore, in the direction perpendicular to the plate thickness of the workpiece 14a, the distance between the vent member 18 and the die 12 is zero.
[0030]
　In the pressing step shown in FIG. 8 (c), the vent material 18 remains punched, pushed in by punching holes 18a pushed back in a state in which punching, the end face 19 that includes a fracture surface 6a of the punching member 18, pressed against the shearing surface including a fracture surface 6 of the workpiece 14a. The vent member 18 spacing is zero the fracture surface and and the die 12 has a fracture surface of the same shape of the workpiece, while still punched, since pushed into drain hole 18a, the fracture surface of the workpiece 14a 6 angle coincides with the fracture surface 6a of the punching member 18 and, on the entire surface of the fracture surface 6 of the workpiece 14a, it is possible to cause plastic deformation of the compression. Preferably, while applying a load to the vent material 18 from the punch 17 pushes the punching member 18 with pushing the punch 13. While applying a load to vent member 18 from the punch 17, by pushing the vent material 18 by pushing the punch 13, at the time of pushing can vent member 18 is prevented from being bent. As long as the curvature of the punching member 18 is allowed, as illustrated in FIG. 8 (c), without applying a load to vent member 18 from the punch 17, may push the vent material 18 by pushing the punch 13.
[0031]
　By spacing d of 5 to 80% of the thickness t of the workpiece 14, the angle of the fracture surface of the shearing surface, it is possible to increase the traveling direction of the punch (thickness direction). The fracture surface 6 of the workpiece 14a, the angle θ with respect to the traveling direction of the punch (thickness direction) is preferably 3 ° or more. Face each other pressing the fracture surfaces 6a of the workpiece 14a of the fracture surface 6 and vent material 18, by having a large angle to the direction of movement of the punch (thickness direction), the plastic deformation of the compression surface of the workpiece it can be generated.
[0032]
　The Push process, why the tensile residual stress is reduced in shearing surface of the workpiece is considered as follows.
[0033]
　FIG. 9 (a) and FIG. 9 (b), the shows a cross-sectional schematic view of the embodiment to press the end surface 19 of the punching member 18 to the shearing face 20 of the workpiece 14a. In FIG. 9 (a), shows a cross-sectional schematic view of the start pressing when the fracture surface 6a of the end face 19 of the punching member 18, against the fracture surface 6 of the shearing surface 20 of the workpiece 14a. In FIG. 9 (b), a schematic cross-sectional view of the plastic deformation area at the time of pressing the completion of the end face 19 of the punching member 18 to the shearing face 20 of the workpiece 14a.
[0034]
　As shown in FIG. 9 (a), in pushing the punch 13, pushed into the holes 18a disconnect the vent member 18 presses the fracture surface 6a of the punching member 18 to the fracture surface 6 of the workpiece 14a. In the method of the present disclosure, the fracture surface 6a of the fracture surface 6 and vent member 18 of the workpiece 14a, the offset angle θ with respect to the traveling direction of the punch is the same. Therefore, it is possible to cause plastic deformation of the stable compressed in the surface layer the entire region of fracture surface 6 of the workpiece 14a. We, will push the vent material 18, the entire end face 19 of the punching member 18, while pressing the entire shearing surface 20 of the workpiece 14a, the pushed back vent member 18 to the same position as the workpiece 14a, FIG. 9 (b), the material overlapping region 20a is formed. Therefore, compressive plastic deformation in the surface layer the entire region of the punched hole 18a occurs workpieces 14a, tensile residual stress can be reduced. In FIG. 9 (b), the second surface 182 of the punching member 18, because the second surface 14a-2 and the same position of the workpiece 14a, the first surface 181 of the vent member 18 is also the working member 14a in substantially the same location one surface 14a-1 and.
[0035]
　The greater the distance d in the predetermined range, the fracture surface 6a of the fracture surface 6 and vent member 18 of the workpiece 14a, it is possible to increase the displacement angle θ with respect to the traveling direction of the punch, widening the material overlap region 20a be able to. A broad material overlapping area 20a, it is possible to increase the reduction amount of tensile residual stress. Accordingly, to the extent that excessive burr is not generated, it is preferable to increase the distance d.
[0036]
　The lower limit of the interval d is more than 5% of the thickness of the workpiece 14, preferably 10% or more, more preferably 15% or more, more preferably 20% or more. The upper limit of the distance d is 80% or less, preferably 60% or less, more preferably 50% or less, more preferably 40% or less, still more preferably 30% or less. By setting the distance d in the above range, it is possible without incurring excessive burrs, increasing the angle θ with respect to the punch moving direction of the fracture surface 6 of the shearing surface.
[0037]
　The distance d is less than 5%, the fracture surface of the vent hole and vent material can not have sufficient angle to the traveling direction of the punch (thickness direction), the plastic of the compression fracture surface shearing surface it is impossible to apply a force causing deformation. Further, if the distance d is less than 5%, the secondary shear plane shear processing surface of the workpiece is likely to occur, can not be sufficiently performed locally against vent hole and vent material caught. If the interval d is more than 80%, can not be performed shearing, ironing becomes processed at distance d is 80% or more, the distance d is greater than 100%, the bending and drawing.
[0038]
　In particular, in the range interval d is 5-30%, it is possible to increase the angle θ of the fracture surface 6, it is possible to obtain a large pressing effect. In range interval d is more than 30% to 80%, it is possible to obtain the pressing effect. However, the range interval d is more than 30%, cracks during shear processing, progressed displaced from the punch angle 17a to the punch advancing direction, the angle θ decreases the fracture surface, the shearing surface of the workpiece large burr may occur. The range interval d is 60 percent, who increased in shearing surface, an extending direction of cracks is further shifted to the punch moving direction, the angle of the fracture surface θ may be reduced.
[0039]
　Bali fracture by crack arising from the punch angle 17a is not a die angle 12a direction, by occurring displaced in the traveling direction of the punch may be formed on the second surface side of the shearing surface of the workpiece. As the distance d increases beyond 30%, burrs are formed on the second surface side of the shearing surface may be larger. When excessive burrs, the fracture surface 6a of the fracture surface 6 and vent member 18 of the workpiece 14a, may shift angle θ becomes smaller with respect to the traveling direction of the punch, and because stretch flangeability also be reduced, excessive to avoid generation of burrs, it is preferable to set the interval d.
[0040]
　In the method of the present disclosure, vent material 18, in a state in which punching is used as a tool for finishing line the shearing surface of the workpiece 14a, the angle θ with respect to the punch moving direction of the fracture surface 6a of the punching member 18, equal to the angle θ with respect to the punch moving direction of the fracture surface 6 of the shearing surface. Therefore, the larger the angle with respect to the punch moving direction of the fracture surface 6 of the shearing surface, the force fracture surface 6a of the punching member 18 pushes the fracture surface 6 of the workpiece 14a can be sufficiently obtained, fracture of the workpiece 14a compressive plastic deformation in the surface layer the entire region of the cross-section 6 can more stably produce by the.
[0041]
　The angle θ of the fracture surface 6 of the shearing surface, preferably against the punch travel direction is 3 ° or more, more preferably 5.5 ° or more, further preferably 11 ° or more. By the angle θ of the fracture surface 6 of the shearing surface 20 is within the above range, the surface layer the entire region of fracture surface 6 of the shearing surface, the plastic deformation of the compression can be generated more stably. Most tensile residual stress fracture surface of the shearing surface may increase. Thus, the fracture surface is most, hydrogen embrittlement resistance and fatigue strength tends to become a problem. Therefore, preferably, to reduce the surface throughout the tensile residual stress in the fracture surface, and more preferably, to reduce the surface throughout the tensile residual stress in the fracture surface and shear plane, more preferably, the tensile of the surface layer the entire region of the shearing surface the residual stress reducing.
[0042]
　The "pressed against the shearing surface" in the present application, at least, it means to press the fracture surface of the vent material fracture surface shearing surface. After pressing the fracture surface of the vent material fracture surface of shearing surfaces may stop pushing the punching member at that time, may pass through the piercing is punching member pushes the vent material.
[0043]
　In pressing process, when pushed back in the hole 18a disconnect the vent member 18 and push the vent member 18 may pass through the vent holes 18a punching member 18. However, shearing surface 20 to perform the coining respect, from the viewpoint of and elongation improve flangeability, the push of the punching member 18, the first face 14a-1 of the second surface 182 of the punching member 18 workpiece 14a it is preferably performed in a range not past the.
[0044]
　The push of the punching member 18, by performing the extent that the second surface 182 of the punching member 18 is not past the first surface 14a-1 of the workpiece 14a, coining can be performed on shearing surface of the workpiece 14a, it is possible to obtain a good stretch flangeability. Therefore, in addition to the excellent hydrogen embrittlement resistance and fatigue strength, is also compatible good stretch flangeability. The second surface 182 of the punching member 18, when pushed position to the vent material 18 passing through the first face 14a-1 of the workpiece 14a, shavings occurs, burrs occurred on the first surface 14a-1 side of the workpiece 14a and, entering additional work hardening. Therefore, stretch flangeability of shearing surface 20 of the workpiece 14a is lowered.
[0045]
　More preferably, the push of the punching member 18, the second surface 182 of the punching member 18 is not past the half the thickness toward the second surface 14a-2 from the first surface 14a-1 of the workpiece 14a carried out in the range. The push of the punching member 18, by performing this range, coining can be performed on the entire shearing surface of the workpiece, that a compressive plastic deformation keep only the surface layer portion of the sheared surface is appropriately alleviated since it is possible to obtain a better stretch flangeability.
[0046]
　More preferably, the push of the punching member 18, the position of the second surface 182 of the punching member 18 is performed such that the second surface 14a-2 of the position substantially the same as the workpiece 14a. At this time, the position of the first surface 181 of the vent member 18 is on the first surface 14a-1 of the position substantially the same as the workpiece 14a. Will be returned to the original position of the vent member 18 vent holes 18a, the entire shearing surface of the workpiece coining can be carried out, only the surface layer portion of the shearing surface compressive plastic deformation is more appropriately alleviated it is possible to keep, it is possible to obtain even better stretch flangeability.
[0047]
　As long as the fracture surface 6a of the vent member rupture surface 6 of the workpiece 14a is pressed, the push of the punching member 18, the second surface 182 of the punching member 18, past the position of the second surface 14a-2 of the workpiece 14a it may be carried out in the absence of range. It this case, coining of the shearing surface of the workpiece can remain in a partial region of the shearing plane, but the surface layer of the fracture surface 6 if it is coined, to obtain the effect of improving the surface properties of the shearing surface can.
[0048]
　The push of the punching member 18, by performing the extent that the second surface 182 of the punching member 18 is not past the first surface of the workpiece 14a, to suppress the hardening upon shaving, be improved stretch flangeability can, it is possible to obtain hydrogen embrittlement resistance, fatigue strength, and the steel material has excellent shearing surface stretch flangeability.
[0049]
　In the present application, the coining, by applying a compressive stress to shearing surface of the workpiece, means to improve the surface condition and shape of the shearing surface, cutting the surface of the shearing surface, clearly-called shaving It is distinguished.
[0050]
　The shaving, the shearing surface of the workpiece, slightly shearing, i.e., means that slightly cut. In the present application, the separation of material by coining is not generated, if the separation of the material occurs are considered shaving.
[0051]
　From shearing machine, it is possible to take out the vent material 18 and the workpiece 14a by any method, for example, from the embodiment shown in FIG. 7, raising the holder 15, it is possible to take out the vent material 18 and the workpiece 14a.
[0052]
　Pushed into the punched hole 18a of the punching member 18 by extrusion punch 17, again, it may push into the holes 18a disconnect the vent member 18 may be repeated further. By repeating pushing the vent member 18 to the vent hole 18a, the tensile residual stress in the shearing surface further reduced, it is possible to improve the hydrogen embrittlement resistance and fatigue characteristics, shearing of the workpiece 14a in working surface 20, the roughness of the shear surface and fracture surface, respectively, can be visually on and smoother.
[0053]
　Punching shape of the punching member as long as it is possible to perform the shearing step and pushing step in the method of the present disclosure, may be circular, elliptical, polygonal, asymmetric, etc., it is a desired shape.
[0054]
　The disclosed method, as shown in FIG. 1 (b), also in the shearing to form an open cross-section (shearing surface) on the workpiece, likewise, to improve the surface properties of the shearing surface of the workpiece it is intended to achieve the effect. It will be described below.
[0055]
　Figure 10 to 13, and shearing the workpiece by the cantilevered shearing machine, a punching member, in a state in which punching is pushed so as to press the end surface of the punching member to shearing surface of the workpiece It shows a cross-sectional schematic view of the embodiment.
[0056]
　Figure 10 shows a cross-sectional schematic view of an embodiment of arranging the workpiece 24 cantilevered shearing machine 200. Figure 11 shows a cross-sectional schematic view of an embodiment of a fixed workpiece 24 cantilevered shearing machine 200. 12, push the punch 27 is a schematic cross-sectional view of the embodiments shearing the workpiece 24. 13, push back the vent material 28 punched out by the punch 27, while still unplugged shows a cross-sectional schematic view of an embodiment of pressing the end face 29 of the punching member 28 in shearing surface 30 of the workpiece 24a.
[0057]
　As shown in FIG. 10, one side of the machine frame 32, the ΔH just pop out and are cantilevered shearing machine 200 from the surface 221 of the pushing punch 23 die 22 held by the elastic member 21, the workpiece 24 to place. As shown in FIG. 11, it presses the holder 25 by the elastic member 26, to secure the workpiece 24 into the die 22 of the shearing machine. Next, as shown in FIG. 12, in a state of fixing the workpiece 24 into the die 22 of the shearing machine, a punch 27, the thickness toward the first surface 241 of the workpiece 24 on the second surface 242 is moved in a direction, it performs shearing of the workpiece 24 to form the vent material 28, the workpiece 24a having a shearing surface 30 including a shear surface and fracture surface. Moving the plate thickness direction of the punch 27 toward the first surface 241 from the second surface 242 is preferably performed while applying a back pressure from pushing the punch 23. Pushing the punch 23, after shearing, the punching member 28, pushed back while still unplugged, as long as it can be pushed into the punched hole 28a, is not particularly limited. Pushing the punch 23, prior to placement of the workpiece 24, even if protruding from the surface 221 of the die 22 in contact with the second surface 242 of the workpiece 24 or may not jump out. The driving method of the indentation punch 23, as long as it can drive the push punch 23, the method is not limited, and instead of the elastic member, for example, may be one operated by a gas cushion or a cam mechanism.
[0058]
　Then, as shown in FIG. 13, a punch 23 pushing by utilizing a repulsive force of the elastic member 21, the vent member 28, is pushed to the punching hole 28a pushes back while still unplugged, the end face 29 of the vent material 28 and against the shearing surface 30 is the contour surface of the drain hole 28a.
[0059]
　Even in the case of performing the cantilevered shearing, for the same reason as in the case of performing shearing illustrated in FIGS. 3-7 and push the vent material 28, may be passed through the can vent holes 28a punching member 28, the push of the punching member 28, the second surface 282 of the punching member 28 is preferably performed within a range that does not pass the first surface 24a-1 of the workpiece 24a, more preferably, the second surface of the workpiece 24a 24A- , in the range from 2 not passed the half the thickness toward the first surface 24a-1, preferably, the position of the second surface 282 of the punching member 28, the workpiece 24a of the second surface 24a-2 performed such that the position substantially the same. Further, the push of the punching member 28, the second surface 282 of the punching member 28 may be carried out in a range that does not pass the position of the second surface 24a-2 of the workpiece 24a.
[0060]
　Even when using a cantilevered shear machine 100 in the disclosed method, the shearing surface, to improve the tensile residual stress is reduced hydrogen embrittlement resistance and fatigue strength, it can also improve stretch flangeability , and the roughness of the shear surface and fracture surface is respectively, smoother than the naked eye, is as described above.
[0061]
　From cantilevered shearing machine 200, to retrieve the vent material 28 processed material 24a, for example, from the state shown in FIG. 13, pushing the punch 27, vent material 28, the workpiece second surface of 24a 24a-2 it may be pushed to the side.
[0062]
　Even when carrying out the method of the present disclosure with reference to cantilever shearing machine, punching shape of the vent material as long as it is possible to perform the shearing step and pushing step in the method of the present disclosure, a circle, an ellipse, polygonal, asymmetric, etc., it can be a desired shape.
[0063]
　Even in the case of implementing the method of the present disclosure in cantilevered shearing machine, the number of repetitions that push the piercing of the vent member, then push is not limited. This number improved by about or surface properties of the shearing surface, may be set in consideration of the productivity.
[0064]
　The disclosed method can also be used when performing an outer trim. In the present application, and the outer peripheral trim, refer to obtaining the outer peripheral side of the workpiece (the outer peripheral portion) punched with a punch, the workpiece on the inner peripheral side (inner circumferential portion) as a product. Periphery trim is particularly useful when requiring products having a large area, such as steel sheets for automobiles, even if the product is a and asymmetrical with a large area, can be applied.
[0065]
　To do periphery trim, die, punch, and pushing the punch, the configuration of the peripheral trim type punch and push the punch on the outer peripheral side of the inner circumferential die is arranged on the side and the workpiece of the workpiece is placed it can have. Punch and pushing punches are arranged so as to face each other across the workpiece.
[0066]
　In the outer peripheral trim, when punching out the outer peripheral portion of the workpiece by a punch, it is necessary to outer peripheral portion to restrain the outer peripheral portion so as not to escape to the outside. As a method for restraining the outer peripheral portion, the following method can be mentioned.
[0067]
　(Embodiment of the peripheral trim 1)
　at least one surface of the stamping surface and the pushing surface of the pushing punch punch has a convex portion, while fixing across the workpiece by the punch and push punch, shearing and pressing it can be carried out.
[0068]
　14, a protrusion 49 provided on the pushing surface of the stamping surface and pushing the punch 43 of the punch 47, an example of the embodiments detained workpiece 44. In this manner, it is possible to the left punch. If provided on at least one protrusion of the punch 47 and the pushing punch 43, since the outer peripheral portion of the workpiece 44 is fixed by a punch 47 and pushing the punch 43, without requiring a new part, increasing the scrap also you need not.
[0069]
　(Embodiment 2 of the outer peripheral trim)
　further outer peripheral side than the punches, arranged to be connected to additional punch to the punch, to further the outer peripheral side than the pushing punch, to be arranged connected to the punch pushes the additional indentation punch it can. At least one surface of the pushing surface of the stamping surface and the additional pushing punches additional punch protrusions 49, punched surface of linked punch and additional punch, as well as pushing surface of linked push punch and additional pushing punch in, while fixing across the outer peripheral portion of the workpiece, it is possible to perform shearing and pressing. Connecting additional indentation punch and push the punch can be carried out by embedding the pin metallic one another. The connecting method is not limited to this method, if the predetermined coupling strength is ensured, regardless the method.
[0070]
　15, connecting the additional punch 47a on the outer peripheral side of the punch 47, and connecting an additional push punch 43a on the outer peripheral side of the indentation punch 43, the convex portion 49 to push surface of the stamping surface and pushing the punch 43a of the additional punch 47a provided, showing an example of the embodiments detained workpiece 44. In this manner, it is possible to the left punch. Also added to form the convex portion 49 punch 47a and the additional pushing punch 43a is exhausted, it is easy to exchange additional punch and additional pushing punch.
[0071]
　(Embodiment 3 of the outer peripheral trim)
　further outer peripheral side than the punch, the additional holder is arranged, the more outer peripheral side than the pushing punch, place additional die said to be opposed to the additional holder across the workpiece be able to. At least one of the additional holder and additional die, the fixed surface facing the first surface and the second surface of the workpiece may have a convex portion. A fixed surface and a fixed surface of the additional die additional holder, while the fixed across the outer peripheral portion of the workpiece, it is possible to perform shearing and pressing.
[0072]
　16, by adding the holder 45a and the additional die 42a is provided a convex portion on the fixing surface, shows a cross-sectional schematic view of an embodiment of the restraining an outer peripheral portion of the workpiece 44. In Figure 16 the outer periphery of the punch 47 and the pushing punch 43, additional holders 45a and additional die 42a is provided a protruding portion 49 on a surface to secure the outer peripheral portion of the workpiece 44 is disposed. The workpiece 44, in addition to a holder 45 and die 42, with additional holders 45a and additional die 42a has a convex portion 49 can be restrained. In this way, while restraining the workpiece 44 performs shearing punch 47, it is possible to perform pressing by pushing the punch 43.
[0073]
　The shape of the convex portion may be as long as it can restrain the workpiece, projections, irregularities are shaped to increase the frictional resistance of the treated surface, and the like. Formation of the protrusions, can be done by embedding a pin having a projection shape at the tip. Formation of irregularities, the cutting can be done by making the groove depth of 10 [mu] m ~ 500 [mu] m on the contact surface with the steel plate. The surface treatment can be carried out by methods sandblasting etc., to increase the frictional resistance.
[0074]
　An outer peripheral portion fixed to the surface of the convex portion provided on a surface of the vertical height of the workpiece is preferably 10 ~ 500 [mu] m. Circle equivalent diameter of the convex portion is preferably 10 ~ 500 [mu] m. The higher the height of the convex portion in the direction perpendicular to the restraining surface of the workpiece, it is possible to increase the binding force, wear of the convex portion tends to increase, also, the load required for biting into the workpiece It rises. As equivalent circle diameter of the projections is small, it is possible to bite into the workpiece with a small load, the wear of the projections tends to increase. As the number of protrusions (density) is small, it is possible to bite into the workpiece with a small load, the weakened binding.
[0075]
　The holder and at least one of the fixed surface of the die for fixing the inner peripheral portion of the product may be provided a convex portion. This embodiment is, because that can cause a deformation by projections on the surface of the product, only if even deformed by protrusions quality of the product is acceptable.
　(Embodiment 4 of the outer trim)
[0076]
　If the intensity of the workpiece is high, correspondingly, the load of the punch is increased, the workpiece is likely further escaped to the outer peripheral side. Therefore, when restraining the workpiece at the die and the holder, it is necessary to increase the restraining load further, even if the constraining the workpiece by a punch having a convex portion, restraint may be insufficient. Further, the strength of the workpiece is increased, the convex portion is easily crushed.
[0077]
　If the intensity of the workpiece is high, restraint in advance by performing the shearing in the desired position on the outer circumference side of the workpiece to form a shearing surface to the end portion of the workpiece, shearing surface formed on the end portion to, it is effective to perform the shearing and pushing the workpiece. The method, the strength of the workpiece is particularly effective when the above 980MPa grade. Shearing surfaces forming the end, as long as possible constraint, the quality of the particular surface texture is not a problem.
[0078]
　(Embodiment 4 of the outer trim)
　in FIG. 17 (a), in order to obtain a shearing surface for restraining shows a cross-sectional schematic view of an embodiment of performing a shearing at a desired position on the outer circumference side of the pre-workpiece. In FIG. 17 (a), the the outer circumferential side of the punch 47, additional punch 47a is disposed. First, with the additional punch 47a and pushing the punch 43, it is possible to perform shearing of the workpiece. In this embodiment, it is necessary push the punch 43 can be fixed.
[0079]
　In FIG. 17 (b), the left end is a shearing surface of the workpiece which has been sheared exhibits a cross-sectional schematic view of an embodiment which is restricted by the side surface of the additional punch 47a. Since the left end of the workpiece is restrained by the side of the additional punch 47a, while suppressing the workpiece escape to the outer peripheral side, with the punch 47 and the die 42, the step of (A) ~ (C) spacing, shearing, and pushing can be carried out.
[0080]
　(Embodiment 5 of the outer trim)
　in FIG. 18 (a), in order to obtain a shearing surface for restraining shows a cross-sectional schematic view of an embodiment of performing a shearing at a desired position on the outer circumference side of the pre-workpiece. In FIG. 18 (a), the respective outer peripheral side of the punch 47 and the pushing punch 43, additional holders 45a and additional die 42a is arranged across the workpiece. First, between the punch 47 and the additional die 42a, it is possible to perform shearing of the workpiece.
[0081]
　Fixing surface for fixing the workpiece in the die 42a is, with respect to the position of the fixed surface of the die 42, arranged dies 42a so as to be located at a higher position in the thickness direction, the same position or a lower position of the workpiece Te, between the punch 47 and the additional die 42a, it is possible to perform shearing of the workpiece.
[0082]
　Fixing surface of the additional die 42a is, to place additional die 42a so as to be positioned higher than the fixed surface of the die 42, the position of the fixed surface of the die 42a with respect to the position of the fixed surface of the die 42, the workpiece deviation in the thickness direction is preferably 3 times the thickness of the workpiece or less, and more preferably not more than 2 times, and may be 1/2 or less of the plate thickness below or thickness. By the displacement in the above range, to suppress the bending of the workpiece during shearing, it is possible to prevent clogging.
[0083]
　If a fixed surface of the additional die 42a to place additional die 42a to be the same position or a lower position relative to the fixed surface of the die 42, the position of the fixed surface of the die 42a with respect to the position of the fixed surface of the die 42, the thickness direction of displacement of the workpiece is less than the thickness of the workpiece. By deviation below the thickness of the workpiece, the left end of the workpiece can be restricted by the side surface of the additional die 42a.
[0084]
　Alternatively, a fixing surface for fixing the workpiece in the die 42a, the position of the fixed surface of the die 42 is arranged to be the same, to fix the additional die 42a and additional holder 45a, the holder 45 and the die 42 and simultaneously operating the punch 47 and the pushing punch 43, it is possible to perform shearing of the workpiece between the punch 47 and the additional die 42a. To operate simultaneously, the holder 45 and the punch 47 is connected, die 42 and a punch 43 and may be connected.
[0085]
　In FIG. 18 (b), the left end of the workpiece which has been sheared exhibits a cross-sectional schematic view of an embodiment which is restricted by the side surface of the additional die 42a. Since the left end of the workpiece is restrained by the side of the additional die 42a, while suppressing the workpiece escape to the outer peripheral side, with the punch 47 and the die 42, the step of (A) ~ (C) spacing, shearing, and pushing can be carried out.
[0086]
　In this embodiment, preferable to use a holder 45a is, becomes large effect of preventing the bending of the workpiece, the use of the holder 45a is arbitrary, if it is possible to stably shearing the workpiece, it is not necessary to use the holder.
[0087]
　(Embodiment 6 of the outer trim)
　in FIG. 18 (a) and the embodiment 5 shown in FIG. 18 (b), after obtaining the shearing surface for restraining, by moving the additional die 42a and additional holders 45a, additional the side of the holder 45a, the left end of the workpiece which has been sheared can be restrained.
[0088]
　As shown in FIG. 19 (b), the left end of the workpiece which has been sheared exhibits a cross-sectional schematic view of an embodiment which is restricted by the side surface of the additional holder 45a. Since the left end of the workpiece is restrained by the side of the additional holders 45a, while suppressing the workpiece escape to the outer peripheral side, with the punch 47 and the die 42, the step of (A) ~ (C) spacing, shearing, and pushing can be carried out.
[0089]
　Generally, shearing using a die and punch are performed, the holder is used to fix the workpiece in combination with the die. Therefore, the die and the punch are made of a relatively high strength material, dimensional accuracy is relatively high, the holder, comparatively intensity is produced at a low material, dimensional accuracy is relatively low. In contrast, in the embodiment of the peripheral trim, die holders, punches, pushing the punch may be used can be used conventional ones, or die as a holder. Embodiments of the peripheral trim, for example a shearing surface using the side of the holder can be constrained, in this case, it may be used holders made of conventional materials and dimensional accuracy, making the die and punch it may be used holders made with materials and dimensions accuracy, or may be from a die as a holder. The same applies to the die and punch.
[0090]
　Workpiece to be machined in the disclosed method is preferably 340MPa or higher class, more preferably a metal plate having a tensile strength of 980MPa or higher class. More preferably, the workpiece to be processed in the method of the present disclosure is a steel having the above tensile strength. In the metal plate having a 340MPa class or higher tensile strength, especially becomes necessary to take measures of fatigue fracture, in the 980MPa grade or higher, it becomes necessary measures of hydrogen embrittlement cracking. Particularly when the workpiece is steel, it measures hydrogen embrittlement cracks and fatigue fracture is important. The method of the present disclosure is applicable to a metal member of any strength, even when applied to a metal member other than steel such as aluminum, may be applied to a low-tension steel plates, or may be applied to a high-tensile steel, tensile residual stress can be reduced. The disclosed method, in particular, by applying a high-tensile steel sheet having the tensile strength, it is possible to achieve both conventionally which was difficult embrittlement resistance, fatigue strength, and stretch flangeability.
[0091]
　Thickness of the workpiece to be processed in the method of the present disclosure, preferably 0.05 ~ 1000 mm, more preferably 0.1 ~ 100 mm, more preferably 0.4 ~ 10 mm, even more preferably 0.6 to it is 2mm. By thickness of the workpiece is in the above range, it is possible to obtain the residual stress reduction effect tensile without bending the workpiece.
[0092]
　Vertical and horizontal dimensions of the workpiece to be processed in the method of the present disclosure is preferably 1 ~ 10000 mm, more preferably 10 ~ 5000 mm, more preferably 100 ~ 1000 mm.
[0093]
　Machining material obtained in the method of the present disclosure can preferably be used various types of vehicles such as automobiles, household appliances, architectural structures, ships, bridges, industrial machinery, construction machinery, various plants, the penstock and the like. For example, in the automotive component applications, the workpiece may be used are further processed.
Example
[0094]
　Next, a description will be given of an embodiment of the present invention, conditions in examples are an example of conditions adopted for confirming the workability and effects of the present invention, the present invention is, in this single condition example the present invention is not limited. The present invention does not depart from the gist of the present invention, as long as they achieve the object of the present invention, it is capable of adopting various conditions.
[0095]
　(Example 1)
　prepared 1180MPa grade DP steel sheet having a thickness of 1.6 mm, using a punch having a diameter .phi.10 mm, subjected to shearing by changing the distance d, to evaluate the cross-sectional shape of the shearing surface. Figure 20 (a) and FIG. 20 (b), the distance d shows a cross-sectional photograph of shearing plane when 5% of the thickness t of the workpiece (CL5%) and 10% (CL10%). Here is omitted the results, black spots seen in the surface layer portion of the shearing surface is trace of Vickers hardness test. Figure 21 (a) ~ (c) , 20% of the distance d, of the workpiece thickness t (CL20%), 30% (CL30%), and shearing surface of the case of 40% (CL40%) It shows a cross-sectional photograph.
[0096]
　Distance d, in the case of 5% and 10% of the thickness t of the workpiece, cracks shearing surface occurs towards the die angle is formed. Distance d, in the case of 20% of the thickness t of the workpiece, as shown in FIG. 21 (a), cracks shearing surface occurs towards the die angle is formed. Distance d, for 30% and 40% of the thickness t of the workpiece, as shown in FIG. 21 (b) and FIG. 21 (c), the crack, the thickness direction of the workpiece from the die angle direction the generated offset, shearing surface is formed, burrs formed on the end portion of the workpiece.
[0097]
　(Example 2)
　except that the die and the distance d of the punch plus Example 1% and 60%, the shearing surface of the shearing the workpiece under the same conditions as in Example 1, pressed against the end face of the punching member when pressed against the end face of the case and vent material it was not was evaluated tensile residual stress in the shearing plane. When pressing the end face of the punching member to shearing surface of the workpiece, the second surface of the vent material so that the position coinciding with the second surface of the workpiece, pushing back the original position of the piercing and punching material.
[0098]
　Figure 22 shows a schematic view of a measuring position of the tensile residual stress in the shearing plane. As shown in FIG. 22, the workpiece, along a line passing through the center of the punched hole, shearing surface of plate thickness along the direction three points of the workpiece 14a, i.e., the second surface of the workpiece 14a 14a- 2-side position (s3), the plate thickness center position (s2), and the first surface position of the workpiece 14a (s1), was irradiated so as not to overlap each other X-ray spot diameter 500 [mu] m, sin 2 [psi method used to measure the tensile residual stresses in said position.
[0099]
　Figure 23-29, the distance d is 1% of the plate thickness t of the workpiece, 5%, 10%, 20%, 30%, 40%, and 60% (CL1%, CL5%, CL10%, CL20 %, CL30%, in the case of CL40%, and CL60%), when pressed against the end face of the case has not pressed and vent material, position (s3), the position (s2), and the three positions (s1) at position shows a tensile residual stress in the shearing surface of the workpiece.
[0100]
　Distance d, in the case of more than 5% of the thickness t of the workpiece, the position (s3) and the position (s2), the tensile residual stress is reduced. The interval d is, when 5 to 40% of the thickness t of the workpiece, while reducing the tensile residual stress was also reduced variation of tensile residual stress.
[0101]
　When the distance d is 10 to 20% of the thickness t of the workpiece, the tensile residual stress in the position (s3) and the position (s2) is greatly reduced. When the distance d is 20% of the thickness t of the workpiece, the thickness direction of the residual stress is having approximately uniform becomes compressed.
[0102]
　Distance d, for about 1% of the thickness t of the workpiece, tensile in conventional method residual stress becomes smaller, the same as to perform a so-called precision shearing. Therefore, a high mold accuracy is required, manufacturing cost of the mold becomes high, in particular it is difficult to prepare a mold for high-tensile steel plate, damage to the mold tends to occur, more shear plane punch is formed longer toward the traveling direction of, for work hardening is often applied, it may decrease even stretch flangeability of shearing surface.
[0103]
　Figure 30, in the sheet thickness center position (s2) of FIG. 23-29 show the residual stress reduction effect when changing die and punch spacing (punching clearance). Die and spacing of the punch, to obtain a plate 5% or more in tensile residual stress reduction effect of the thickness of the workpiece, a larger tensile residual stress reduction effect is obtained at 10% to 40%, 10% and 30% greater tensile residual stress reduction effect is obtained, further larger tensile residual stress reduction effect of 10% to 20% was obtained. The large tensile residual stress reduction effect of 10% to 20% was obtained, when the die and spacing of the punch is less than 20%, the size of the burr formed is considered because it was kept small.
[0104]
　Figure 31, with respect to the workpiece evaluated in FIGS. 23-29, shows the relationship between the angle θ of the fracture surface of the case was not performed against the die and punch spacing (punching clearance). And the angle θ of the fracture surface of the workpiece is the angle with respect to the traveling direction of the punch (thickness direction). Die and spacing of the punches, at least 5% of the plate thickness workpiece, 3 angle θ of ° or more fracture surface obtained, the interval of the die and the punch is 10% to 60%, 20% and 40%, and in the range of 20-30%, the angle of the larger fracture surface θ is obtained.
[0105]
　Table 1 shows the relationship between the die and the spacing d of the punch and the angle θ of the fracture surface of the workpiece.
[table 1]

[0106]
　Figure 32 shows the relationship between the die and when the punch interval (punching clearance) is of 5 to 20% and 30 to 60% angle of the fracture surface θ and the tensile residual stress reduction effect. Data shown in FIG. 32, based on the results of FIGS. 30 and 31. An angle of the fracture surface θ is 3 ° or more, a large tensile residual stress reduction effect was obtained. Further, when the die and punch spacing (punching clearance) is 5-20%, die and than the punch interval (punching clearance) is 30 to 60% with respect to the angle θ of the same fracture surface, and more large tensile residual stress reduction effect was obtained.
　(Example 3)
　In Example 2, when the distance d between the die and the punch was 20% was evaluated mean tensile residual stress in the shearing plane by pressing the presence or absence of the punching member.
[0107]
　An average tensile residual stress shearing surface of the workpiece when performing the pressing of the vent material was calculated to compare the average tensile residual stress shearing plane when not subjected to pressing of the vent material. The results are shown in Table 2.
[0108]
[Table 2]

[0109]
　From Table 2, by pressing the punching material, is added compressive stress in the shearing surface, it can be seen that the tensile residual stress in the shearing surface of the workpiece is reduced.
[0110]
　(Example 4)
　the spacing d of the die and the punch 5%, 10%, and as 20% for steel sheet subjected to shearing under the same conditions as in Example 1, the end face of the punching member under the same conditions as in Example 2 when pressed against the end face of the case has not pressed and vent material were investigated hydrogen embrittlement characteristics in shearing surface. Hydrogen embrittlement characteristics, specific liquid volume 15 mL / cm 2 to, 1 ~ 100 g / L test steel sheet ammonium thiocyanate solution was immersed for 72 hours, was assessed. The results are shown in Tables 3 and 4. The presence of hydrogen embrittlement cracks, was evaluated by visual observation.
[0111]
[table 3]

[0112]
[Table 4]

[0113]
　As shown in Table 3 and 4, by pressing the end face of the punching member to shearing surface of the workpiece, hydrogen embrittlement characteristics were greatly improved.
[0114]
　(Example 5)
　were evaluated fatigue properties of shearing surface of the steel plate by pressing the presence or absence of the punching member. As the workpiece, the plate thickness prepared 1180MPa grade DP steel sheet 1.6 mm, the distance d of the punch die and the diameter 10 mm, 20% of the plate thickness of the steel sheet, i.e. a 0.32 mm, subjected to shearing, to give the workpiece and the punching material. Then, the second surface of the vent material is subjected to coining the shearing surface of pressing the piercing of the vent material to match the position of the second surface of the workpiece the workpiece. For pressing without and pressing there workpieces, the stress ratio -1 and frequency as 25 Hz, at room temperature air was flat bending fatigue test. 33, the fatigue characteristics measured by flat bending fatigue test showing a (.sigma.a: Bending number: fatigue limit, Nf). From Figure 33, by performing the coining against an end face of the punching member to shearing surface of the workpiece, it can be seen that the tensile residual stress is improved fatigue properties decrease.
[0115]
　(Example 6)
　was examined a relationship between the stretch flangeability of the shearing surface to the return position of the punching member workpiece. Specifically, in the case of performing a shearing only, after shearing, the punching member 18, the position of the second surface 182 coincides with the second surface 14a-2 of the workpiece punching member 18, i.e., to the original position If returned, and after shearing, in the case where allowed through the vent hole 18a in the punching member 18, was investigated stretch flangeability of shearing surface of the workpiece. As the workpiece 14 prepared 1180MPa grade DP steel plate having a plate thickness of 1.6 mm, using a punch having a diameter .phi.10 mm, as a 20% the distance d, we were shearing.
[0116]
　Test of stretch flangeability, the test method shown in FIG. 34, the workpiece was evaluated by performing a hole expansion test. Using a conical punch vertical angles 60 ° to hole expansion test, a wrinkle holding force is set to 9.8 kN, the punch speed during spread holes of about 0.2 mm / sec, the test of the workpiece 14a so burrs becomes upper set up a piece, fixed in the die 12 and the holder 15. These other conditions are in compliance with ISO16630 (2009). Hole expanding test was performed 10 times for each experimental condition.
[0117]
　Figure 35, when subjected to shearing only (Case1: punching only), after shearing, when returning holes 18a disconnect the vent material 18 (Case2: punching + coining), and after shearing, the punching member 18 If allowed through the drain hole 18a: shows (Case3 punching + shaving) of the graph comparing stretch flangeability of shearing surface of the workpiece.
[0118]
　In case3, when passing through the the vent hole 18a punching member 18, together with the shearing surface of the workpiece is scraped, since work hardening by large compressive stress is applied to the shearing face from being granted, stretch flangeability There lowered. In case2, shearing surface is coined by returning to the original position of the holes 18a disconnect the vent material 18, favorable stretch flangeability is obtained. Although not shown here, comparing Case1 and Case2, since the Case2 coining is performed, as compared with the Case1, obtain excellent resistance to hydrogen embrittlement resistance and fatigue strength.
[0119]
　(Example 7)
　as a workpiece, thickness was prepared 1180MPa grade DP steel sheet 1.6 mm. The distance d of the punch die and the diameter 10 mm, 20% of the plate thickness of the steel sheet, i.e., set to 0.32 mm. In this condition, by shearing the steel sheet with a punch, to obtain a workpiece and vent material. The vent material, while still unplugged, let through by pushing the vent hole, then again, let me through push the piercing of the vent material from the opposite side, to the shearing surface of the steel plate of the end face of the vent member pressing was performed.
[0120]
　For each of the workpiece which was processed material and pressing was not carried out pressing, along a line passing through the center of the punched hole, three points along the thickness direction of the workpiece, i.e., the second surface side of the workpiece position (s3), the plate thickness center position (s2), and the first surface position of the workpiece (s1), was irradiated so as not to overlap each other X-ray spot diameter 500 [mu] m, sin 2 with Ψ method, They were compared to investigate the average tensile residual stress of the position. The results are shown in Table 5.
[0121]
[table 5]

Industrial Applicability
[0122]
　As described above, according to the present invention, the shearing of the steel, the steel having excellent shearing surface of the surface texture, good productivity, and can be manufactured at low cost. Accordingly, the present invention has high applicability in the steel production industry.
DESCRIPTION OF SYMBOLS
[0123]
　1 workpiece
　2 punch
　2a downward
　3 die
　4 sagging
　5 shear plane
　6 fracture surface
　6a broken surface
　7 burr
　8a top surface
　8b bottom surface
　9 shearing surface
　10 workpiece
　11 elastic member
　12 die
　12a die angle
　13 pushing the punch
　14 to be workpiece
　14a workpiece
　15 holder
　16 the elastic member
　17 punches
　17a punch angle
　18 vent member
　18a drain hole
　19 the end face
　20 shearing surface
　20a materials overlap region
　21 elastic members
　22 die
　23 pushing the punch
　24 workpiece
　24a workpiece
　25 holder
　26 elastically member
　27 punch
　28 vent member
　28a drain hole
　29 the end face
　30 shearing surface
　32 machine frame
　42 die
　42a adds the die
　43 pushing the punch
　43a additional pushing punch
　44 workpiece
　45 holder
　45a adds the holder
　47 punch
　47a adds punch
　49 protrusions
　1 0 shearing machine
　200 cantilevered shearing machine
　d punch and spacing of the die
　plate thickness of t workpiece
　measurement position of s1, s2, s3 residual stress

The scope of the claims
[Claim 1]
　A first surface and a workpiece having a second surface on the opposite side, so that the second surface is disposed on the die side, placed on the die, said from the first surface of the workpiece wherein toward the second surface in the thickness direction of the workpiece, a shearing method of shearing a punch disposed on the first surface side,
　was at a distance between the punch and the (a) the die the vertical spacing in the thickness direction of the workpiece, the distance setting step of 5% to 80% of the thickness of the workpiece, Te
　and shearing the workpiece by (B) the punch , a shearing step for obtaining a vent material and processing material, the punching member and the workpiece, respectively, having a first surface and a second surface corresponding to the first and second surfaces of the workpiece, shear processing step, and
　(C) disposed on the second surface side of the workpiece so as to face the punch By and included punching, the punching member, while still unplugged, push the punched hole of the workpiece, steps, pressing pressing the end surface of the vent material shearing surface of the workpiece
　including, shearing Method.
[Claim 2]
　Wherein in the step (A), the interval is 10% to 80% of the said die and said punch, shear processing method according to claim 1.
[Claim 3]
　Wherein in the step (A), the interval is 10 to 30% of said die and said punch, shear processing method according to claim 1.
[Claim 4]
　In the step (C), comprising a push of the punching member performs in the range where the second surface of the punching member is not past the first surface of the workpiece, coining the shearing surface of the workpiece, shearing method according to any one of claims 1 to 3.
[Claim 5]
　In the step (C), the push of the punching member, to the extent that the position of the second surface of the vent material is not past the half the thickness from the second surface of the workpiece toward the first surface performed comprises coining the shearing surface of the workpiece, shearing method according to any one of claims 1 to 3.
[Claim 6]
　In the step (C), the push of the punching member, the position of the second surface of the vent material is performed so as to be the same as the position of the second surface of the workpiece, the shearing surface of the workpiece comprising coining, shearing method according to any one of claims 1 to 3.
[Claim 7]
　In the step (C), the push of the punching member, the position of the second surface of the vent material is performed within a range not past the position of the second surface of the workpiece, at least the shearing surface of the workpiece comprising coining part, shearing method according to any one of claims 1 to 3.
[8.]
　In the step (C), punching the punching member is pushed into the vent holes with the punch, the repeated in pushing punch the punching member said drain hole than once pushing any one of claims 1 to 7 shear processing method according to an item.
[Claim 9]
　Said die, said punch, and said pushing punch, configuration of the outer peripheral trim type the punch and the pushing punch on the outer peripheral side of the workpiece the die on the inner peripheral side of the are arranged and the workpiece is placed to have,
　that at least one surface of the stamping surface and the pushing surface of the pushing punch of the punch has a convex portion, and
　wherein while fixing across the workpiece by the punch and the pushing punch, said shear performing the processing and the pressing,
　including, shearing method according to any one of claims 1 to 8.
[Claim 10]
　Said die, said punch, and said pushing punch, configuration of the outer peripheral trim type the punch and the pushing punch on the outer peripheral side of the workpiece the die on the inner peripheral side of the are arranged and the workpiece is placed to have,
　in addition the outer peripheral side of the punch, placing and coupling the additional punch to the punch,
　to further the outer peripheral side of the pushing punch, as opposed to the additional punch across the workpiece in, add a pushing punch placing coupled to the push-punch,
　that at least one surface of the stamping surface and the pushing surface of the additional pushing punch of said additional punch has a convex portion, and
　the concatenated punch and blanked surface of the additional punch, as well as pushing surface of the concatenated pushing punch and additional pushing punch, the workpiece Nde while fixed, to perform the shearing and the pressing,
　including, shearing method according to any one of claims 1 to 8.
[Claim 11]
　Said die, said punch, and said pushing punch, configuration of the outer peripheral trim type the punch and the pushing punch on the outer peripheral side of the workpiece the die on the inner peripheral side of the are arranged and the workpiece is placed to have,
　in addition the outer peripheral side of the punch, place additional holder
　further outer peripheral side than the pushing punch, so as to face the additional holder across the workpiece, place additional die it
　that at least one surface of the fixed surface facing the second surface of the workpiece fixing surface and the additional die facing the first surface of the workpiece of the additional holder having a convex portion, and
　a fixed surface of the fixing surface and the additional die of the additional holder, while the fixed across the workpiece, to perform the shearing and the pressing
　including, claim 1-8 Shearing method according to any one of.
[Claim 12]
　Said die, said punch, and said pushing punch, configuration of the outer peripheral trim type the punch and the pushing punch on the outer peripheral side of the workpiece the die on the inner peripheral side of the are arranged and the workpiece is placed to have,
　in addition the outer peripheral side of the punch, placing the additional punch,
　between the additional punch and said pushing punch, said obtaining the shearing to shear plane the workpiece, and
　the shear plane constraining the sides of the additional punch, the interval setting, the shearing, and to perform the pressing,
　including, shearing method according to any one of claims 1 to 8.
[Claim 13]
　Said die, said punch, and said pushing punch, configuration of the outer peripheral trim type the punch and the pushing punch on the outer peripheral side of the workpiece the die on the inner peripheral side of the are arranged and the workpiece is placed to have,
　more outer peripheral side than the pushing punch, placing the additional die,
　between the punch and the additional die, said obtaining the shearing to shear plane the workpiece, and
　the shear plane , and restrained by the side surface of the additional die, the interval setting, the shearing, and to perform the pressing,
　including, shearing method according to any one of claims 1 to 8.
[Claim 14]
　Said die, said punch, and said pushing punch, configuration of the outer peripheral trim type the punch and the pushing punch on the outer peripheral side of the workpiece the die on the inner peripheral side of the are arranged and the workpiece is placed to have,
　in addition the outer peripheral side of the punch, placing the additional holder,
　in further the outer peripheral side of the push punch, so as to face the additional holder across the workpiece, place additional die it is
　in the punch and the additional die, said obtaining the shearing to shear plane the workpiece, and
　the shear plane, and restrained by the side surface of the additional die or additional holder, the interval setting, the shearing, and to perform the pressing,
　including, shearing method according to any one of claims 1 to 8.
[Claim 15]
　The workpiece is a metal plate having a 340MPa class or higher tensile strength, shearing method according to any one of claims 1 to 14.
[Claim 16]
　The workpiece is a metal plate having a 980MPa class or higher tensile strength, shearing method according to any one of claims 1 to 14.
[Claim 17]
　The workpiece is steel, shearing method according to claim 15 or 16.