METHOD FOR MANUFACTURING METAL MEMBER, MOLD, AND METAL MEMBER

Abstract

Provided is a method for manufacturing a metallic member having excellent corrosion resistance on a cut end surface thereof. This method for manufacturing a metallic member is a method for manufacturing a metallic member by punching, with a mold (20), a metal plate (10) having front and rear surfaces coated with a coating layer. The mold (20) includes a punch (21), a counter pad (22), holddowns (23), and dies (24). The holddowns (23) each have a protruding portion (231) at an inner peripheral edge section of a surface facing the metal plate (10), the protruding portion (231) of each of the holddowns (23) has a shoulder portion having a radius R1 of curvature on an inner circumference side, and the radius R1 of curvature is at least 0.10 times the thickness of the metal plate (10). The manufacturing method comprises: a step for pushing the protruding portion (231) of the holddown (23) into the metal plate (10); and a step for bringing the punch (21) and the dies (24) closer to the metal plate (10) to punch the metal plate (10).

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a metal member, a mold, and a metal member. [Background technology]

[0002] Steel components for automobiles and building materials are often manufactured by press working. When corrosion resistance is required for steel components, cold-rolled or hot-rolled steel sheets are pressed and then painted or plated. However, adding a painting or plating process after press working increases the work time and costs.

[0003] One possible solution to this problem is to press-form plated steel sheets. However, when plated steel sheets are subjected to press-forming processes that involve cutting, such as punching, the plating layer is separated at the cut edge, exposing the steel base. If the steel base is left exposed at the cut edge, corrosion will occur from the cut edge. Therefore, a process is required to plate the cut edge where the steel base is exposed, which increases work time and costs.

[0004] Japanese Patent Application Laid-Open Publication No. 2021-133391 describes a die for cutting comprising a fixed die and a movable die. The movable die is configured so that, as the movable die cuts a metal plate, a first-stage cutting process is performed in which the clearance between the fixed die and the movable die is c+Δc (Δc>0), and after the first-stage cutting process, a second-stage cutting process is performed in which the clearance between the fixed die and the movable die is c.

[0005] JP 2017-87294 A describes a cutting method in which the clearance between the die and punch is 1 to 20% of the thickness of the surface-treated steel sheet, and cutting is performed using a mold in which the shoulder of at least one of the die or punch is given a radius of curvature that is 0.12 times or more the thickness of the surface-treated steel sheet.

[0006] In Japanese Patent Application Laid-Open No. 2009-287082, a die consisting of a die, a punch, and a die holder is used to produce a Zn coating of 10 g / m per side.2 The above describes a method for cutting a zinc-based plated steel sheet having a thickness of 2.0 mm or less, in which the shoulder of one of the die and punch facing the product steel sheet is rounded with a radius of curvature of 0.10 to 0.50 times the thickness of the steel sheet, the other shoulder and the shoulder of the die holder are at right angles, and a mold is used in which the sides of the die and die holder are aligned, and the cutting is performed with a clearance between the die and punch of 1.0% or less of the steel sheet thickness.

[0007] Japanese Patent Application Laid-Open Publication No. 2020-32437 describes a cut product formed by cutting a multilayer material in which the surface of a base material is coated with a coating material. The cut end surface of this cut product consists of a first inclined surface that slopes from the first surface toward the center in the plate thickness direction, a second inclined surface that slopes from the second surface toward the center in the plate thickness direction, and a fracture surface formed between the first inclined surface and the second inclined surface. At least a portion of the first inclined surface and the second inclined surface are covered with a coating material that covers the surface of the base material.

[0008] Furthermore, as a precision shearing process that can obtain smooth cut end surfaces, the "opposed die shearing method" is known (see, for example, Japanese Patent Application Laid-Open Nos. 6-182461, 2000-210731, and 2005-14062). [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2021-133391 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-87294 [Patent Document 3] Japanese Patent Application Laid-Open No. 2009-287082 [Patent Document 4] Japanese Patent Publication No. 2020-32437 [Patent Document 5] Japanese Patent Application Publication No. 6-182461 [Patent Document 6] Japanese Patent Application Laid-Open No. 2000-210731 [Patent Document 7] Japanese Patent Application Laid-Open No. 2005-14062 Summary of the Invention [Problem to be solved by the invention]

[0010] Japanese Patent Application Laid-Open Nos. 2021-133391, 2017-87294, and 2009-287082 describe methods for wrapping the plating layer of a material around the cut end surface by devising a mold shape. However, these methods have a limit to the amount of plating components that can be supplied to the cut end surface because the plating layer wraps around from only one direction.

[0011] The object of the present invention is to provide a method for manufacturing a metal component having excellent corrosion resistance at its cut end surface, a mold capable of manufacturing a metal component having excellent corrosion resistance at its cut end surface, and a metal component having excellent corrosion resistance at its cut end surface. [Means for solving the problem]

[0012] A method for manufacturing a metal component according to one embodiment of the present invention is a method for manufacturing a metal component by punching a metal plate, the front and back surfaces of which are covered with coating layers, using a die, wherein the die comprises: a punch; a counter pad arranged opposite the punch with the metal plate sandwiched between them; a plate holder arranged on the punch side in the thickness direction of the metal plate and arranged surrounding the punch in the in-plane direction of the metal plate; and a die arranged on the counter pad side in the thickness direction of the metal plate and arranged surrounding the counter pad in the in-plane direction of the metal plate; the plate holder has a protrusion portion on the inner peripheral edge of the surface facing the metal plate, and the protrusion portion of the plate holder has a shoulder portion on the inner peripheral side with a radius of curvature R1, the radius of curvature R1 being 0.10 times or more the thickness of the metal plate; and the manufacturing method comprises the steps of: pressing the protrusion portion of the plate holder into the metal plate; and punching out the metal plate by bringing the punch and the die close to each other.

[0013] A method for manufacturing a metal component according to one embodiment of the present invention is a method for manufacturing a metal component by punching a metal plate, the front and back surfaces of which are covered with coating layers, using a die, wherein the die comprises: a punch; a counter pad arranged opposite the punch with the metal plate sandwiched between them; a plate holder arranged on the punch side in the thickness direction of the metal plate and arranged to surround the punch in the in-plane direction of the metal plate; and a die arranged on the counter pad side in the thickness direction of the metal plate and arranged to surround the counter pad in the in-plane direction of the metal plate; the punch has a protrusion on the peripheral edge of the surface facing the metal plate, and the protrusion of the punch has a shoulder on the outer periphery with a radius of curvature R3, the radius of curvature R3 being 0.10 times or more the thickness of the metal plate; and the manufacturing method comprises the steps of: pressing the protrusion of the punch into the metal plate; and punching out the metal plate by bringing the counter pad and the plate holder close to each other.

[0014] A mold according to one embodiment of the present invention comprises a punch, a counter pad arranged opposite the punch with a metal plate as the workpiece sandwiched therebetween, a plate holder arranged on the punch side in the thickness direction of the metal plate and surrounding the punch in the in-plane direction of the metal plate, and a die arranged on the counter pad side in the thickness direction of the metal plate and surrounding the counter pad in the in-plane direction of the metal plate, wherein the plate holder has a protrusion on the inner peripheral edge of the surface facing the metal plate, and the protrusion of the plate holder has a shoulder on the inner peripheral side with a radius of curvature R1, and the radius of curvature R1 is 0.2 mm or more.

[0015] A mold according to one embodiment of the present invention comprises a punch, a counter pad arranged opposite the punch across a metal plate that is a workpiece, a plate holder arranged on the punch side in the thickness direction of the metal plate and surrounding the punch in the in-plane direction of the metal plate, and a die arranged on the counter pad side in the thickness direction of the metal plate and surrounding the counter pad in the in-plane direction of the metal plate, wherein the punch has a protrusion on the peripheral edge of the surface facing the metal plate, and the protrusion of the punch has a shoulder on the outer periphery with a radius of curvature R3, and the radius of curvature R3 is 0.2 mm or more.

[0016] A metal component according to one embodiment of the present invention is a metal component formed by punching a metal plate whose front and back surfaces are covered with a coating layer, and has a cut end surface formed by the punching process, which includes a shear surface and a recessed surface which is a curved surface having a shape that is convex toward the inside of the component, and at least a portion of the recessed surface is covered by the coating layer.

[0017] A method for manufacturing a metal member according to one embodiment of the present invention includes the steps of: A method for manufacturing a metal member by punching a metal plate, the front and back surfaces of which are covered with a coating layer, using a die, The mold is Punch and a counter pad disposed opposite the punch with the metal plate interposed therebetween; a plate holder that is disposed on the punch side in the thickness direction of the metal plate and that is disposed to surround the punch in the in-plane direction of the metal plate; a die disposed on the counter pad side in the thickness direction of the metal plate and surrounding the counter pad in the in-plane direction of the metal plate, The mold further has the following configuration A) or B): A) The plate holder has a protrusion on the inner peripheral edge of the surface facing the metal plate, and the protrusion of the plate holder has a shoulder on the inner peripheral side with a radius of curvature R1, and the radius of curvature R1 is 0.10 times or more the thickness of the metal plate. B) The punch has a protrusion on the peripheral edge of the surface facing the metal plate, and the protrusion of the punch has a shoulder on the outer periphery with a radius of curvature R3, and the radius of curvature R3 is 0.10 times or more the thickness of the metal plate. The manufacturing method includes: a step of pressing the protrusion of the plate holder into the metal plate; and a step of punching the metal plate.

[0018] The mold according to one embodiment of the present invention comprises: Punch and a counter pad disposed opposite the punch with a metal plate as a workpiece sandwiched therebetween; a plate holder that is disposed on the punch side in the thickness direction of the metal plate and that is disposed to surround the punch in the in-plane direction of the metal plate; a die disposed on the counter pad side in the thickness direction of the metal plate and surrounding the counter pad in the in-plane direction of the metal plate, A mold further having the following configuration A) or B): A) The plate holder has a protrusion on the inner peripheral edge of the surface facing the metal plate, and the protrusion of the plate holder has a shoulder on the inner peripheral side with a radius of curvature R1, and the radius of curvature R1 is 0.2 mm or more. B) The punch has a protrusion on the peripheral edge of the surface facing the metal plate, and the protrusion of the punch has a shoulder on the outer periphery with a radius of curvature R3, and the radius of curvature R3 is 0.2 mm or more. [Effects of the Invention]

[0019] According to the present invention, a metal member having excellent corrosion resistance at the cut end surface can be obtained. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a cross-sectional view schematically showing the configuration of a mold according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view showing a part of the plate holder of the mold shown in FIG. [Figure 3] FIG. 3 is a cross-sectional view showing a modified example of the plate holder of the mold of FIG. [Figure 4] FIG. 4 is a flow diagram of a method for manufacturing a metal member according to one embodiment of the present invention. [Figure 5] FIG. 5 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 6] FIG. 6 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 7] FIG. 7 is a schematic cross-sectional view showing an enlarged view of the vicinity of the protrusion. [Figure 8] FIG. 8 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 9] FIG. 9 is a cross-sectional view that schematically shows the configuration of a metal member according to one embodiment of the present invention. [Figure 10] FIG. 10 is a cross-sectional view schematically showing the configuration of a mold according to the second embodiment of the present invention. [Figure 11] FIG. 11 is a cross-sectional view showing a part of the die of the mold shown in FIG. [Figure 12] FIG. 12 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 13] FIG. 13 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 14] FIG. 14 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 15] FIG. 15 is a cross-sectional view that schematically shows the configuration of a metal member according to one embodiment of the present invention. [Figure 16] FIG. 16 is a cross-sectional view schematically showing the configuration of a mold according to the third embodiment of the present invention. [Figure 17] FIG. 17 is a cross-sectional view showing a part of the die of the mold shown in FIG. [Figure 18] FIG. 18 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 19] FIG. 19 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 20]FIG. 20 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 21] FIG. 21 is a cross-sectional view that schematically shows the configuration of a metal member according to one embodiment of the present invention. [Figure 22] FIG. 22 is a cross-sectional view schematically showing the configuration of a mold according to the fourth embodiment of the present invention. [Figure 23] FIG. 23 is a cross-sectional view showing a part of the punch of the die of FIG. [Figure 24] FIG. 24 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 25] FIG. 25 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 26] FIG. 26 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 27] FIG. 27 is a cross-sectional view schematically showing the configuration of a mold according to the fifth embodiment of the present invention. [Figure 28] 28 is a cross-sectional view showing a part of the counter pad of the mold of FIG. [Figure 29] FIG. 29 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 30] FIG. 30 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 31] FIG. 31 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 32] FIG. 32 is a cross-sectional view schematically showing the configuration of a mold according to the sixth embodiment of the present invention. [Figure 33] 33 is a cross-sectional view showing a part of the counter pad of the mold of FIG. [Figure 34] FIG. 34 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 35] FIG. 35 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 36] FIG. 36 is a schematic cross-sectional view of the metal member during its manufacture. [Figure 37]FIG. 37 is a diagram showing a schematic view of the distribution of the plating layer when the protrusion of the sheet holder is pressed into the metal sheet, obtained by CAE. [Figure 38] FIG. 38 is a graph showing the relationship between the radius of curvature R1 and the plating coverage distance d. [Figure 39] FIG. 39 is a diagram for explaining the plating coverage. [Figure 40] FIG. 40 is a diagram showing the plating coverage obtained by CAE. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and the description thereof will not be repeated. The dimensional ratios between the components shown in each drawing do not necessarily represent the actual dimensional ratios.

[0022] [First embodiment] [Mold] FIG. 1 is a cross-sectional view schematically showing the configuration of a die 20 according to a first embodiment of the present invention. The die 20 is a die used for punching a metal plate. The die 20 includes a punch 21, a counter pad 22, a sheet holder (upper die) 23, and a die (lower die) 24. The counter pad 22 is disposed opposite the punch 21 across the metal plate 10, which is the workpiece. The sheet holder 23 is disposed on the punch 21 side in the thickness direction of the metal plate 10 (the z direction in FIG. 1), and is disposed so as to surround the punch 21 in the in-plane direction of the metal plate 10 (the xy in-plane direction in FIG. 1). The die 24 is disposed on the counter pad 22 side in the thickness direction of the metal plate 10, and is disposed so as to surround the counter pad 22 in the in-plane direction of the metal plate 10.

[0023] The punch 21 and the counter pad 22 have surfaces 21a and 22a, respectively, that face the metal sheet 10. Both surfaces 21a and 22a are flat surfaces parallel to the metal sheet 10. The surfaces 21a and 22a have the same planar shape (shape of the xy plane). The planar shapes of the surfaces 21a and 22a may be any shape, such as a circle, an ellipse, or a rectangle.

[0024] A predetermined clearance CL is provided between the punch 21 and the plate holder 23. Similarly, a predetermined clearance CL is provided between the counter pad 22 and the die 24. It is preferable that the clearance CL is approximately constant over the entire outer periphery of the punch 21 or the counter pad 22.

[0025] The sheet holder 23 has a protrusion 231 on the inner peripheral edge of the surface 23a facing the metal sheet 10. Here, the inner peripheral edge of the surface 23a means the peripheral edge adjacent to the punch 21.

[0026] The surface 24 a of the die 24 facing the metal plate 10 is a flat surface parallel to the metal plate 10 .

[0027] 2 is a cross-sectional view showing a portion of the plate holder 23. The protrusion 231 has a shoulder 231a with a curvature radius R1 on the inner circumferential side. Here, the inner circumferential side of the protrusion 231 means the side of the protrusion 231 adjacent to the punch 21.

[0028] The radius of curvature R1 of the shoulder portion 231a is preferably 0.2 mm or more. The radius of curvature R1 is more preferably 0.3 mm or more, even more preferably 0.5 mm or more, even more preferably 0.8 mm or more, and even more preferably 1.0 mm or more. The radius of curvature R1 of the shoulder portion 231a is preferably 0.10 times or more the thickness of the metal plate 10, which is the workpiece. The lower limit of the radius of curvature R1 is more preferably 0.20 times the thickness of the metal plate 10, even more preferably 0.30 times the thickness of the metal plate 10. The upper limit of the radius of curvature R1 is preferably 0.40 times the thickness of the metal plate 10.

[0029] The height h1 of the protrusion 231 is preferably at least 0.25 times the thickness of the metal plate 10, which is the workpiece. The lower limit of the height h1 is more preferably 0.30 times the thickness of the metal plate 10, and even more preferably 0.50 times the thickness of the metal plate 10. The upper limit of the height h1 is preferably 1.00 times the thickness of the metal plate 10.

[0030] The shape of the side opposite to the shoulder 231a of the protrusion 231 is arbitrary. In the example of FIG. 2, the protrusion 231 has an inclined portion 231b on the side opposite to the shoulder 231a. The inclined portion 231b has a shape that bulges outward (away from the punch 21) as it approaches the surface 23a. Providing such an inclined portion 231b in the protrusion 231 can improve the durability of the protrusion 231. Note that the inclined portion 231b may have a linear shape as shown in FIG. 2, or may have a curved shape like the inclined portion 231Ab shown in FIG. 3.

[0031] [Metal component manufacturing method] Next, a method for manufacturing a metal member according to one embodiment of the present invention will be described. The method for manufacturing a metal member according to this embodiment is a method for manufacturing a metal member by punching a metal plate covered on both sides with a coating layer (hereinafter referred to as a "surface-coated metal plate") using the above-mentioned die 20.

[0032] The base material of the surface-coated metal sheet is, but is not limited to, steel, copper, copper alloy, aluminum, aluminum alloy, etc. The manufacturing method according to this embodiment is particularly suitable when the base material of the surface-coated metal sheet is steel. This is because steel is prone to rust, and imparting corrosion resistance is a significant advantage. The coating layer is a plating layer, a paint layer, a resin layer, etc. A representative example of the coated metal sheet is a plated steel sheet. Examples of the plated steel sheet include a Zn-based plated steel sheet and an Al-based plated steel sheet. In the following explanation, a plating layer will be used as a representative example of the coating layer, and a surface-plated metal sheet will be used as a representative example of the surface-coated metal sheet.

[0033] The surface-plated metal sheet is more preferably a Zn-plated steel sheet. Zn-based plating has a sacrificial corrosion protection effect on the base steel sheet. Therefore, it is possible to suppress corrosion from the exposed portion of the base material at the cut end surface due to shearing, and to further improve the corrosion resistance of the manufactured metal member. Zn-based plating includes, but is not limited to, hot-dip galvannealing, galvannealed galvannealing, Zn-Ni-based plating, Zn-Al-based plating, Zn-Mg-based plating, Zn-Al-Mg-based plating, etc.

[0034] The thickness of the surface-plated metal sheet is not particularly limited, but is, for example, 1.0 to 6.0 mm.

[0035] The thickness of the plating layer of the surface-plated metal sheet (thickness of one side; the same applies below) is preferably 15 μm or more. If the plating layer is too thin, the plating layer that can cover the cut end surface will be depleted, and corrosion resistance may not be imparted to the cut end surface. The lower limit of the thickness of the plating layer of the surface-plated metal sheet is more preferably 30 μm. The upper limit of the thickness of the plating layer of the surface-plated metal sheet is not particularly limited, but is, for example, 150 μm.

[0036] 4 is a flow diagram of a method for manufacturing a metal component according to one embodiment of the present invention. This manufacturing method includes a step (step S1) of placing a surface-plated metal sheet (hereinafter simply referred to as "metal sheet 10") on counter pad 22 and die 24, a step (step S2) of pressing protrusion 231 of sheet holder 23 into metal sheet 10, and a step (step S3) of bringing punch 21 and die 24 close to each other to punch out metal sheet 10.

[0037] Each step will be described below with reference to Figs. 5 to 8. These figures are all schematic diagrams. As mentioned above, the dimensional ratios between the components shown in each figure do not necessarily represent the actual dimensional ratios (the same applies to Figs. 1 to 3 and Fig. 9 onwards).

[0038] The metal plate 10 is placed on the counter pad 22 and the die 24 (step S1, see FIG. 5). The front and back surfaces of the metal plate 10 are covered with plating layers 10a. While FIG. 5 and other figures illustrate a case where the end surfaces of the metal plate 10 are also covered with plating layers 10a, the end surfaces of the metal plate 10 do not necessarily have to be covered with plating layers 10a.

[0039] The protrusion 231 of the plate holder 23 is pressed into the metal plate 10 (step S2, see FIG. 6). For example, a press machine (not shown) or the like is used to apply the same amount of pressure to the punch 21 and the counter pad 22 to sandwich the metal plate 10 and hold it. In this state, the position of the die 24 is fixed, and the plate holder 23 is moved closer to the die 24, so that the protrusion 231 of the plate holder 23 is pressed into the metal plate 10. Note that instead of applying the same amount of pressure to the punch 21 and the counter pad 22, the metal plate 10 may be sandwiched by applying pressure to one of the punch 21 and the counter pad 22 while the other is fixed in position.

[0040] 7 is a schematic cross-sectional view showing an enlarged view of the vicinity of the protrusion 231. When the protrusion 231 is pressed in, a recess 10b is formed in the metal plate 10, and a part of the plating layer 10a wraps around the inner wall of the recess 10b. At this time, since the shoulder 231a of the protrusion 231 has a predetermined radius of curvature R1, the plating layer 10a can wrap around the inner wall 10b1 on the shoulder 231a side of the two inner walls 10b1 and 10b2 of the recess 10b.

[0041] This inner wall 10b1 is located inside (towards the center of the punch 21) the surface of the protrusion 231 in the in-plane direction (xy in-plane direction) of the metal plate 10. That is, a minute gap is formed between the inner wall 10b1 and the protrusion 231. This is because the portion into which the protrusion 231 is pressed moves towards the center of the punch 21 due to plastic flow.

[0042] FIG. 7 shows a case where the plating layer 10a also extends around the inner wall 10b2 on the inclined portion 231b side, but the plating layer 10a does not have to extend around the inner wall 10b2.

[0043] The punch 21 and the die 24 are brought close to each other to punch out the metal plate 10 (step S3; see FIG. 8). For example, with the die 24 held in a fixed position, pressure is applied to the plate holder 23, and the metal plate 10 is sandwiched between the plate holder 23 and the die 24 to hold the metal plate 10. In this state, the punch 21 is moved close to the die 24 to punch out the metal plate 10. At this time, a pressure smaller than that applied to the punch 21 may be applied to the counter pad 22 to support the metal plate 10 from below.

[0044] In addition, instead of applying pressure to the plate holder 23 while the position of the die 24 is fixed, the metal plate 10 may be clamped by applying pressure to the die 24 while the position of the plate holder 23 is fixed, or by applying the same amount of pressure to the plate holder 23 and the die 24.

[0045] Also, instead of moving the punch 21, the die 24 may be moved to punch out the metal plate 10. That is, with the metal plate 10 sandwiched between the punch 21 and the counter pad 22, the die 24 may be moved closer to the punch 21 to punch out the metal plate 10. Also, the metal plate 10 may be punched out by moving both the punch 21 and the die 24.

[0046] As a result, the metal plate 10 is separated into the metal member 11 and a remaining portion 119. In this embodiment, the portion sandwiched between the punch 21 and the counter pad 22 becomes the metal member 11. At this time, a part of the plating layer 10a wraps around to the cut end surface 111 of the metal member 11 from one surface of the metal plate 10 (the surface in contact with the counter pad 22).

[0047] Steps S2 and S3 can also be performed as a single process by using a double-action press or a device that can independently drive the punch 21 and the plate holder 23. However, performing steps S2 and S3 separately is preferable because it simplifies the structure of the device. For example, a simple structure can be achieved in which step S2 is formed using only the plate holder 23 by lowering the press machine, and step S3 is punched by lowering the punch 21 while pressurizing the plate holder 23 with a spring or the like.

[0048] In the above explanation, the metal plate 10 is placed on the counter pad 22 and the die 24, and then processed. However, the arrangement of the mold 20 in the up-down direction (z direction) may be reversed, and the metal plate 10 may be placed on the punch 21 and the plate holder 23, and then processed. In this case, the step of pressing the protrusion 231 of the plate holder 23 into the metal plate 10 (step S2) and the step of bringing the punch 21 and the die 24 close to each other to punch out the metal plate 10 (step S3) can be performed in the same way.

[0049] [Metal parts] 9 is a cross-sectional view schematically showing the configuration of a metal member 11 according to one embodiment of the present invention. The metal member 11 is a metal member formed by punching a surface-plated metal sheet. The metal member 11 has a cut end surface 111 formed by punching.

[0050] In addition to the cut end surface 111, the metal member 11 has a first surface 112 and a second surface 113 that is the surface opposite to the first surface 112. The planar shapes (shapes in the xy plane) of the first surface 112 and the second surface 113 may be any shape. The first surface 112 and the second surface 113 are covered with a plating layer 10a. The plating layer 10a is a plating layer derived from the plating layer of the surface-plated metal sheet that is the raw material.

[0051] The cut end surface 111 includes a shear surface 111a, a recessed surface 111b, and a sag 111e adjacent to the recessed surface 111b.

[0052] The cut end surface 111 further includes a fractured surface 111c and a sag (second sag) 111d adjacent to the sheared surface 111a. The fractured surface 111c is located between the sheared surface 111a and the recessed surface 111b in the thickness direction (z direction) of the metal member 11. The sag 111d is located on the opposite side of the recessed surface 111b with respect to the sheared surface 111a in the thickness direction (z direction) of the metal member 11. In other words, the sheared surface 111a is located between the recessed surface 111b and the sag 111d in the thickness direction (z direction) of the metal member 11.

[0053] Depending on the processing conditions, the cut end surface 111 may not include the fracture surface 111c.

[0054] The recessed surface 111b is a surface formed by the step (step S2 in FIG. 4) of pressing the protrusion 231 into the metal plate 10. While the sags 111d and 111e are curved surfaces that are convex toward the outside of the component, the recessed surface 111b is a curved surface that is convex toward the inside of the component.

[0055] The recessed surface 111b is recessed by a sinking amount W1 from the sheared surface 111a. The sinking amount W1 is the distance between the tangent to the sheared surface 111a and the deepest position of the recessed surface 111b in the cross section of the metal member 11. The sinking amount W1 is, for example, 0.01 to 0.15 times the thickness of the metal member 11. The lower limit of the sinking amount W1 is preferably 0.02 times the thickness of the metal member 11. The upper limit of the sinking amount W1 is preferably 0.10 times the thickness of the metal member 11.

[0056] In this embodiment, at least a portion of the recessed surface 111b is covered with the plating layer 10a, thereby improving the corrosion resistance of the cut end surface 111.

[0057] In addition to at least a portion of the recessed surface 111b being covered by the plating layer 10a, it is preferable that 50% or more of the combined area of ​​the recessed surface 111b and the sag 111e adjacent to the recessed surface 111b be covered by the plating layer 10a. More specifically, when the dimensions of the recessed surface 111b and the sag 111e along the thickness direction of the metal plate 10 are t1 and t2, respectively, and the dimension along the thickness direction of the metal plate 10 of the portion of the combined area of ​​the recessed surface 111b and the sag 111e that is covered by the plating layer 10a is d, it is preferable that d / (t1 + t2) be 0.5 or more (50% or more). Whether or not the cut end surface 111 is covered by the plating layer 10a can be determined, for example, by measuring the cut end surface 111 with an energy dispersive X-ray analyzer (EDX).

[0058] More preferably, d / (t1+t2) is 75% or more. Most preferably, the entire recessed surface 111b is covered with the plating layer 10a.

[0059] The sag 111d adjacent to the sheared surface 111a is usually entirely covered with the plating layer 10a. The sheared surface 111a is at least partially covered with the plating layer 10a. The fractured surface 111c is usually not covered with the plating layer 10a.

[0060] The plating layer 10a covering the sheared surface 111a, the recessed surface 111b, the sag 111d, and the sag 111e is a plating layer derived from the plating layer of the surface-plated metal sheet, which is the raw material, similar to the plating layer 10a covering the first surface 112 and the second surface 113. Therefore, the plating layer 10a covering the sheared surface 111a, the recessed surface 111b, and the sag 111d is the same plating layer as the plating layer 10a covering the first surface 112 and the second surface 113.

[0061] [Effects of this embodiment] The mold 20, the method for manufacturing a metal member, and the metal member 11 according to the first embodiment of the present invention have been described above. The plate holder 23 of the mold 20 has a protrusion 231 on the inner peripheral edge of the surface 23a facing the metal plate 10. The protrusion 231 has a shoulder 231a with a curvature radius R1 (FIG. 2) on the inner peripheral side. By pressing the protrusion 231 into the metal plate 10, a recess 10b (FIG. 7) is formed in the metal plate 10, and a portion of the plating layer 10a wraps around the inner wall of the recess 10b. Because the shoulder 231a of the protrusion 231 has a predetermined curvature radius R1, the plating layer 10a can wrap around the inner wall 10b1 of the two inner walls 10b1 and 10b2 of the recess 10b, which is closer to the shoulder 231a. This inner wall 10b1 corresponds to the recessed surface 111b of the metal member 11 (FIG. 9). At least a portion of the recessed surface 111b is covered with the plating layer 10a.

[0062] According to the mold 20 of this embodiment and the method for manufacturing a metal member of this embodiment, the plating layer 10a can be supplied from both sides of the cut end surface 111 in the thickness direction (z direction). That is, the plating layer 10a can be supplied not only from the second surface 113 but also from the first surface 112. Specifically, in addition to the sag 111d and the sheared surface 111a, at least a portion of the recessed surface 111b can also be covered with the plating layer 10a. This allows a metal member 11 having excellent corrosion resistance at the cut end surface 111 to be obtained.

[0063] Second to sixth embodiments of the present invention will be described below. In these descriptions, differences from the first embodiment will be mainly described, and overlapping descriptions will be omitted as appropriate.

[0064] [Second embodiment] [Mold] 10 is a cross-sectional view schematically showing the configuration of a mold 30 according to a second embodiment of the present invention. The mold 30 includes a die 34 instead of the die 24 of the mold 20 (FIG. 1) of the first embodiment.

[0065] The die 34 has a protrusion 341 on the inner peripheral edge of the surface 34a facing the metal plate 10. Here, the inner peripheral edge of the surface 34a means the peripheral edge adjacent to the counter pad 22.

[0066] 11 is a cross-sectional view showing a portion of the die 34. The die 34 has a shoulder 341a with a curvature radius R2 on the inner periphery side. Here, the inner periphery side of the protrusion 341 means the side of the protrusion 341 adjacent to the counter pad 22.

[0067] The preferred range of the radius of curvature R2 of the shoulder portion 431a is the same as the radius of curvature R1 (FIG. 2) of the shoulder portion 231a of the protrusion 231 of the plate holder 23. Note that the radius of curvature R1 and the radius of curvature R2 may be the same or different.

[0068] The preferred range of the height h2 of the protrusion 431 is the same as the height h1 (FIG. 2) of the protrusion 231 of the plate holder 23. The height h1 and the height h2 may be the same or different.

[0069] [Metal component manufacturing method] The method for manufacturing a metal component according to this embodiment is a method for manufacturing a metal component by punching a surface-plated metal sheet using the above-described die 30. This manufacturing method includes the steps of placing metal sheet 10 on counter pad 22 and die 34, pressing protrusion 231 of sheet holder 23 and protrusion 341 of die 34 into metal sheet 10, and punching out metal sheet 10 by bringing punch 21 and die 34 close to each other. Each step will be described below with reference to FIGS. 12 to 14.

[0070] The metal plate 10 is placed on the counter pad 22 and the die 34 (see FIG. 12). Note that in this embodiment as well, the arrangement of the die 30 in the vertical direction (z direction) may be reversed, and the metal plate 10 may be placed on the punch 21 and the plate holder 23 before processing.

[0071] The protrusion 231 of the plate holder 23 and the protrusion 341 of the die 34 are pressed into the metal plate 10 (see FIG. 13 ). For example, the metal plate 10 is sandwiched between the punch 21 and the counter pad 22 to hold the metal plate 10. In this state, the plate holder 23 and the die 34 are moved closer to each other to press the protrusion 231 of the plate holder 23 and the protrusion 341 of the die 34 into the metal plate 10. Note that instead of moving both the plate holder 23 and the die 34, one of the plate holder 23 and the die 34 may be fixed and only the other may be moved. In this case, too, the protrusion 231 of the plate holder 23 and the protrusion 341 of the die 34 can be pressed into the metal plate 10 by appropriately controlling the pressure applied to the punch 21 and the counter pad 22.

[0072] The punch 21 and the die 34 are brought close to each other to punch out the metal plate 10 (see FIG. 14). As a result, the metal plate 10 is separated into the metal member 12 and a remaining portion 129. In this embodiment, the portion sandwiched between the punch 21 and the counter pad 22 becomes the metal member 12.

[0073] [Metal parts] Figure 15 is a cross-sectional view schematically showing the configuration of a metal member 12 according to one embodiment of the present invention. The metal member 12 is a metal member formed by punching a surface-plated metal sheet. The metal member 12 has a cut end surface 121 formed by punching. In addition to the cut end surface 121, the metal member 12 has a first surface 122 and a second surface 123. The first surface 122 and the second surface 123 are covered with a plating layer 10a.

[0074] The cut end surface 121 includes a shear surface 121a, a recessed surface 121b, and a sag 121e adjacent to the recessed surface 121b.

[0075] The cut end surface 121 further includes a fractured surface 121c, a second recessed surface 121d, and a sag 121f adjacent to the second recessed surface 121d. The fractured surface 121c is located between the sheared surface 121a and the recessed surface 121b in the thickness direction (z direction) of the metal member 12. The second recessed surface 121d is located on the opposite side of the recessed surface 121b with respect to the sheared surface 121a in the thickness direction (z direction) of the metal member 12. In other words, the sheared surface 121a is located between the recessed surface 121b and the second recessed surface 121d in the thickness direction (z direction) of the metal member 12.

[0076] In this embodiment as well, depending on the processing conditions and the like, the cut end surface 121 may not include the fracture surface 121c.

[0077] Both the recessed surface 121b and the second recessed surface 121d are curved surfaces that convex toward the inside of the member. The range of the sinking depth W2 of the recessed surface 121b and the range of the sinking depth W3 of the second recessed surface 121d are the same as the sinking depth W1 of the recessed surface 111b of the metal member 11 (FIG. 9). Note that the sinking depth W3 of the second recessed surface 121d tends to be smaller than the sinking depth W2 of the recessed surface 121b.

[0078] In this embodiment as well, at least a portion of the recessed surface 121b is covered with the plating layer 10a. This improves the corrosion resistance of the cut end surface 121. In this embodiment as well, in addition to at least a portion of the recessed surface 121b being covered with the plating layer 10a, it is more preferable that 50% or more of the combined area of ​​the recessed surface 121b and the sag 121e adjacent to the recessed surface 121b be covered with the plating layer 10a. The preferable percentage of the combined area of ​​the recessed surface 121b and the sag 121e that is covered with the plating layer 10a is the same as in the case of the metal member 11.

[0079] The sag 121f adjacent to the second recessed surface 121d is usually entirely covered with the plating layer 10a. At least a portion of the second recessed surface 121d is covered with the plating layer 10a. The sheared surface 121a may be entirely covered, partially covered, or not covered at all with the plating layer 10a. The fractured surface 121c is usually not covered with the plating layer 10a.

[0080] [Effects of this embodiment] The mold 30, the method for manufacturing a metal member, and the metal member 13 according to the second embodiment of the present invention have been described above. According to this embodiment, by pressing the protrusions 231 and 341 into the metal plate 10, the plating layer 10a can be supplied from both sides of the metal plate 10 in the thickness direction. Furthermore, even when punching out the remaining central portion, the shoulder 341a of the protrusion 341 has a predetermined radius of curvature R2, which allows more of the plating layer 10a to wrap around the cut end surface 121. This allows a metal member 12 with excellent corrosion resistance at the cut end surface 121 to be obtained.

[0081] [Third embodiment] [Mold] 16 is a cross-sectional view schematically showing the configuration of a mold 40 according to a third embodiment of the present invention. The mold 40 includes a die 44 instead of the die 24 of the mold 20 (FIG. 1) of the first embodiment.

[0082] FIG. 17 is a cross-sectional view showing a portion of a die 44. The surface 44a of the die 44 facing the metal plate 10 is a flat surface parallel to the metal plate 10. The die 44 has a two-step shoulder on its inner circumferential side. Here, the inner circumferential side of the die 44 refers to the side adjacent to the counter pad 22. The two-step shoulder includes a first shoulder 441 and a second shoulder 442. The second shoulder 442 is located farther from the metal plate 10 than the first shoulder 441 in the thickness direction (z direction) of the metal plate 10, and is located closer to the counter pad 22 than the first shoulder 441 in the in-plane direction (xy in-plane direction) of the metal plate 10.

[0083] The step height sh1 of the two-step shoulder portion is preferably more than 0 times and not more than 0.50 times the thickness of the metal plate 10, which is the workpiece. The step height sh1 is the distance along the z direction from the surface 44a to the apex of the second shoulder portion 442 (the position closest to the surface 44a). The lower limit of the step height sh1 is preferably 0.10 times the thickness of the metal plate 10, and more preferably 0.20 times.

[0084] The width w1 of the two-step shoulder portion is preferably 0.10 to 0.70 times the thickness of the metal sheet 10, which is the workpiece. The width w1 is the distance along the xy plane between the side surface of the first shoulder portion 441 and the side surface of the second shoulder portion 442 (the inner peripheral surface of the die 44). The lower limit of the width w1 is preferably 0.10 times the thickness of the metal sheet 10, and more preferably 0.20 times.

[0085] The radius of curvature Rp2 of the second shoulder portion 442 is preferably 0.1 mm or more. The radius of curvature Rp2 is more preferably 0.2 mm or more, and even more preferably 0.3 mm or more. The radius of curvature Rp2 of the second shoulder portion 442 is preferably 0.10 times or more the thickness of the metal plate 10, which is the workpiece. The lower limit of the radius of curvature Rp2 is more preferably 0.20 times the thickness of the metal plate 10. The upper limit of the radius of curvature Rp2 is preferably 0.70 times the thickness of the metal plate 10.

[0086] There are no particular limitations on the radius of curvature Rp1 of the first shoulder portion 441. The radius of curvature Rp1 is, for example, 0 to 0.50 times the radius of curvature Rp2. The radius of curvature Rp1 may be 0.

[0087] [Metal component manufacturing method] The method for manufacturing a metal component according to this embodiment is a method for manufacturing a metal component by punching a surface-plated metal sheet using the above-described die 40. This manufacturing method includes the steps of placing metal sheet 10 on counter pad 22 and die 44, pressing protrusion 231 of sheet holder 23 into metal sheet 10, and punching out metal sheet 10 by bringing punch 21 and die 44 close to each other. Each step will be described below with reference to Figures 18 to 20.

[0088] The metal plate 10 is placed on the counter pad 22 and the die 44 (see FIG. 18). Note that in this embodiment, the arrangement of the die 40 in the vertical direction (z direction) may also be reversed, and the metal plate 10 may be placed on the punch 21 and the plate holder 23 before processing.

[0089] The protrusion 231 of the plate holder 23 is pressed into the metal plate 10 (see FIG. 19 ). For example, the metal plate 10 is sandwiched between the punch 21 and the counter pad 22 to hold the metal plate 10. In this state, the plate holder 23 is moved closer to the die 44, and the protrusion 231 of the plate holder 23 is pressed into the metal plate 10.

[0090] The punch 21 and the die 44 are brought close to each other to punch out the metal plate 10 (see FIG. 20). As a result, the metal plate 10 is separated into the metal member 13 and a remaining portion 139. In this embodiment, the portion sandwiched between the punch 21 and the counter pad 22 becomes the metal member 13.

[0091] [Metal parts] Figure 21 is a cross-sectional view schematically showing the configuration of a metal member 13 according to one embodiment of the present invention. The metal member 13 is a metal member formed by punching a surface-plated metal sheet. The metal member 13 has a cut end surface 131 formed by punching. In addition to the cut end surface 131, the metal member 13 has a first surface 132 and a second surface 133. The first surface 132 and the second surface 133 are covered with a plating layer 10a.

[0092] The cut end surface 131 includes a sheared surface 131a, a recessed surface 131b, a fractured surface 131c, a sag 111d, and a sag 111e. The configuration of the cut end surface 131 is substantially the same as that of the cut end surface 111 of the metal member 11 (FIG. 9). More specifically, in the cut end surface 131, the size of the sag 131d is larger than that of the sag 111d (FIG. 9), and accordingly, the proportions of the sheared surface 131a and the fractured surface 131c are different from those of the metal member 11.

[0093] [Effects of this embodiment] According to this embodiment, during the process of punching the metal plate 10, the width w1 (FIG. 17) of the two-step shoulder portion increases the clearance between the punch 21 and the die 44, resulting in greater sagging of the cut end surface. As a result, the portion that contacts the second shoulder portion 442 is in a moderately inclined state, which makes it easier for the plating layer 10a to move toward the cut end surface during shaping by the second shoulder portion 442. This results in a metal member 13 with excellent corrosion resistance at the cut end surface 131.

[0094] [Fourth embodiment] [Mold] 22 is a cross-sectional view schematically showing the configuration of a mold 50 according to a fourth embodiment of the present invention. The mold 50 includes a punch 51 instead of the punch 21 of the mold 20 (FIG. 1) of the first embodiment, and a plate holder 53 instead of the plate holder 23.

[0095] The punch 51 has a protrusion 511 on the periphery of a surface 51a facing the metal plate 10.

[0096] A surface 53 a of the plate holder 53 facing the metal plate 10 is a flat surface parallel to the metal plate 10 .

[0097] 23 is a cross-sectional view showing a portion of punch 51. Protrusion 511 has shoulder 511a with a radius of curvature R3 on the outer periphery side. Here, the outer periphery side of protrusion 511 means the side of protrusion 511 adjacent to plate holder 53.

[0098] The preferred range of the radius of curvature R3 of the shoulder 511a is the same as the radius of curvature R1 (FIG. 2) of the shoulder 231a of the protrusion 231 of the plate holder 23. The preferred range of the height h3 of the protrusion 511 is the same as the height h1 (FIG. 2) of the protrusion 231 of the plate holder 23.

[0099] [Metal component manufacturing method] The method for manufacturing a metal component according to this embodiment is a method for manufacturing a metal component by punching a surface-plated metal sheet using the above-described die 50. This manufacturing method includes the steps of placing metal sheet 10 on counter pad 22 and die 24, pressing protrusion 511 of punch 51 into metal sheet 10, and punching out metal sheet 10 by bringing counter pad 22 and sheet holder 53 close to each other. Each step will be described below with reference to Figures 24 to 26.

[0100] The metal plate 10 is placed on the counter pad 22 and the die 24 (see FIG. 24). Note that in this embodiment, the arrangement of the die 50 in the vertical direction (z direction) may also be reversed, and the metal plate 10 may be placed on the punch 51 and the plate holder 53 before processing.

[0101] The protrusion 511 of the punch 51 is pressed into the metal plate 10 (see FIG. 25). For example, the metal plate 10 is sandwiched between the plate holder 53 and the die 24 to hold the metal plate 10. In this state, the punch 51 is moved closer to the counter pad 22, and the protrusion 511 of the punch 51 is pressed into the metal plate 10.

[0102] The counter pad 22 and the plate holder 53 are brought close to each other to punch out the metal plate 10 (see FIG. 26). As a result, the metal plate 10 is separated into the metal member 14 and a remaining portion 149. In this embodiment, the portion sandwiched between the plate holder 53 and the die 24 becomes the metal member 14.

[0103] [Metal parts] The metal member 14 has a similar configuration to the metal member 11 according to the first embodiment (FIG. 9), except for its planar shape (xy plane shape). That is, the metal member 14 is a metal member formed by punching a surface-plated metal sheet, and has a cut end surface formed by the punching process. This cut end surface includes a sheared surface and a recessed surface, and at least a portion of the recessed surface is covered with the plating layer 10a.

[0104] [Effects of this embodiment] The mold 50, the method for manufacturing a metal member, and the metal member 14 according to the fourth embodiment of the present invention have been described above. The mold 50 and the method for manufacturing a metal member according to this embodiment also allow the plating layer 10a to wrap around from both sides of the cut end surface in the thickness direction. This allows the metal member 14 to have excellent corrosion resistance at the cut end surface.

[0105] [Fifth embodiment] [Mold] 27 is a cross-sectional view schematically showing the configuration of a mold 60 according to a fifth embodiment of the present invention. The mold 60 includes a counter pad 62 instead of the counter pad 22 of the mold 50 (FIG. 22) of the fourth embodiment.

[0106] The counter pad 62 has a protrusion 621 on the periphery of a surface 62a facing the metal plate 10.

[0107] 28 is a cross-sectional view showing a portion of the counter pad 62. The protrusion 621 has a shoulder 621a with a curvature radius R4 on the outer periphery side. Here, the outer periphery side of the protrusion 621 means the side of the protrusion 621 adjacent to the die 24.

[0108] The preferred range of the radius of curvature R4 of the shoulder portion 621a is the same as the radius of curvature R1 (FIG. 2) of the shoulder portion 231a of the protrusion 231 of the plate holder 23. The radius of curvature R3 (FIG. 23) and the radius of curvature R4 may be the same or different.

[0109] The preferred range of the height h4 of the protrusion 621 is the same as the height h1 (FIG. 2) of the protrusion 231 of the plate holder 23. Note that the height h3 (FIG. 23) and the height h4 may be the same or different.

[0110] [Metal component manufacturing method] The method for manufacturing a metal component according to this embodiment is a method for manufacturing a metal component by punching a surface-plated metal sheet using the above-described die 60. This manufacturing method includes the steps of placing metal sheet 10 on counter pad 62 and die 24, pressing protrusion 511 of punch 51 and protrusion 621 of counter pad 62 into metal sheet 10, and punching out metal sheet 10 by bringing counter pad 62 and sheet holder 53 close together. Each step will be described below with reference to Figures 29 to 31.

[0111] The metal plate 10 is placed on the counter pad 62 and the die 24 (see FIG. 29). Note that in this embodiment as well, the arrangement of the die 60 in the vertical direction (z direction) may be reversed, and the metal plate 10 may be placed on the punch 51 and plate holder 53 before processing.

[0112] The protrusion 511 of the punch 51 and the protrusion 621 of the counter pad 62 are pressed into the metal plate 10 (see FIG. 30 ). For example, the metal plate 10 is sandwiched between the plate holder 53 and the die 24 to hold the metal plate 10. In this state, the punch 51 and the counter pad 62 are moved closer to each other, and the protrusion 511 of the punch 51 and the protrusion 621 of the counter pad 62 are pressed into the metal plate 10.

[0113] The counter pad 62 and the plate holder 53 are brought close to each other to punch out the metal plate 10 (see FIG. 31). As a result, the metal plate 10 is separated into the metal member 15 and a remaining portion 159. In this embodiment, the portion sandwiched between the plate holder 53 and the die 24 becomes the metal member 15.

[0114] [Metal parts] The metal member 15 has a similar configuration to the metal member 12 according to the second embodiment (FIG. 15), except for its planar shape (xy plane shape). That is, the metal member 15 is a metal member formed by punching a surface-plated metal sheet, and has a cut end surface formed by the punching process. This cut end surface includes a sheared surface and a recessed surface, and at least a portion of the recessed surface is covered with the plating layer 10a.

[0115] [Effects of this embodiment] The above describes the mold 60, the method for manufacturing a metal member, and the metal member 15 according to the fifth embodiment of the present invention. According to this embodiment, by pressing the protrusions 511 and 621 into the metal plate 10, the plating layer 10a can be supplied from both sides of the metal plate 10 in the thickness direction. Furthermore, even when punching out the remaining central portion, the shoulder 621a of the protrusion 621 has a predetermined radius of curvature R4, which allows more of the plating layer 10a to wrap around the cut end surface. This results in a metal member 15 with excellent corrosion resistance at the cut end surface.

[0116] [Sixth embodiment] [Mold] 32 is a cross-sectional view schematically showing the configuration of a mold 70 according to the sixth embodiment of the present invention. The mold 70 includes a counter pad 72 instead of the counter pad 22 of the mold 50 (FIG. 22) of the fourth embodiment.

[0117] FIG. 33 is a cross-sectional view showing a portion of the counter pad 72. The surface 72a of the counter pad 72 facing the metal plate 10 is a flat surface parallel to the metal plate 10. The counter pad 72 has a two-step shoulder on its outer periphery. Here, the outer periphery of the counter pad 72 refers to the side adjacent to the die 24. The two-step shoulder includes a first shoulder 721 and a second shoulder 722. The second shoulder 722 is located farther from the metal plate 10 than the first shoulder 721 in the thickness direction (z direction) of the metal plate 10, and is located closer to the die 24 than the first shoulder 721 in the in-plane direction (xy in-plane direction) of the metal plate 10.

[0118] The preferred range of the step height sh2 of the two-step shoulder portion is the same as the step height sh1 (FIG. 17) of the two-step shoulder portion of the die 44. The preferred range of the width w2 of the two-step shoulder portion is also the same as the width w1 (FIG. 17) of the two-step shoulder portion of the die 44.

[0119] The preferred range of the radius of curvature Rp4 of the second shoulder 722 is the same as the radius of curvature Rp2 of the second shoulder 442 of the die 44 (FIG. 17). The radius of curvature Rp3 of the first shoulder 721 is not particularly limited. For example, the radius of curvature Rp3 is 0 to 0.5 times the radius of curvature Rp4. The radius of curvature Rp3 may be 0.

[0120] [Metal component manufacturing method] The method for manufacturing a metal component according to this embodiment is a method for manufacturing a metal component by punching a surface-plated metal sheet using the above-described die 70. This manufacturing method includes the steps of placing metal sheet 10 on counter pad 72 and die 24, pressing protrusion 511 of punch 51 into metal sheet 10, and punching out metal sheet 10 by bringing counter pad 22 and sheet holder 53 close to each other. Each step will be described below with reference to Figures 34 to 36.

[0121] The metal plate 10 is placed on the counter pad 72 and the die 24 (see FIG. 34). Note that in this embodiment, the arrangement of the die 70 in the vertical direction (z direction) may also be reversed, and the metal plate 10 may be placed on the punch 51 and the plate holder 53 before processing.

[0122] The protrusion 511 of the punch 51 is pressed into the metal plate 10 (see FIG. 35 ). For example, the metal plate 10 is sandwiched between the plate holder 53 and the die 24 to hold the metal plate 10. In this state, the punch 51 is moved closer to the counter pad 72, and the protrusion 511 of the punch 51 is pressed into the metal plate 10.

[0123] The counter pad 72 and the plate holder 53 are brought close to each other to punch out the metal plate 10 (see FIG. 36). As a result, the metal plate 10 is separated into the metal member 16 and a remaining portion 169. In this embodiment, the portion sandwiched between the plate holder 53 and the die 24 becomes the metal member 16.

[0124] [Metal parts] The metal member 16 has a similar configuration to the metal member 13 according to the third embodiment (FIG. 21), except for its planar shape (xy plane shape). That is, the metal member 16 is a metal member formed by punching a surface-plated metal sheet, and has a cut end surface formed by the punching process. This cut end surface includes a sheared surface and a recessed surface, and at least a portion of the recessed surface is covered with the plating layer 10a.

[0125] [Effects of this embodiment] According to this embodiment, during the process of punching the metal sheet 10, the width w2 (FIG. 33) of the two-step shoulder increases the clearance between the counter pad 72 and the sheet holder 53, resulting in greater sagging of the cut edge surface. This causes the portion in contact with the second shoulder 722 to be inclined to an appropriate degree, making it easier for the plating layer 10a to move to the cut edge surface during shaping by the second shoulder 722. This results in a metal member 16 with excellent corrosion resistance at the cut edge surface. [Example]

[0126] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0127] The behavior of the plating layer when a surface-plated metal sheet is processed using a mold 20 (FIG. 1) was analyzed using CAE. LS-DYNA (registered trademark) was used as the software. FIG. 37 is a diagram showing a schematic diagram of the distribution of the plating layer obtained by CAE when the protrusion 231 of the sheet holder 23 is pressed into the surface-plated metal sheet. The thickness of the target surface-plated metal sheet was 3.2 mm, and the pressing depth S was 1.6 mm without taking the plating thickness into consideration. Analysis was performed by changing the radius of curvature R1 of the shoulder 231a of the protrusion 231 of the sheet holder 23 (FIG. 2), and the relationship between the radius of curvature R1 and the plating coverage distance d (the dimension of the portion covered by the plating layer along the thickness direction of the surface-plated metal sheet) was investigated.

[0128] The results are shown in Figure 38. As shown in Figure 38, it can be seen that the larger the radius of curvature R1, the larger the area covered with the plating layer can be.

[0129] Next, the plating coverage of the cut end surface when punching a surface-plated metal sheet using die 20 (Fig. 1), die 30 (Fig. 10), and die 40 (Fig. 16) was analyzed using CAE. The thickness of the surface-plated metal sheet in question was 3.2 mm, and the plating thickness was not taken into consideration. The clearance CL (Fig. 1, etc.) was 0.1 mm.

[0130] The height h1 of the protrusion 231 (FIG. 2) of the plate holder 23 was set to 1.6 mm, and the radius of curvature R1 of the shoulder 231a was set to 0.9 mm. In an analysis simulating the mold 30 (FIG. 10), the height h2 of the protrusion 341 (FIG. 11) of the die 34 was set to 1.6 mm, and the radius of curvature R2 of the shoulder 341a was set to 0.9 mm. In an analysis simulating the mold 40 (FIG. 16), the radius of curvature Rp1 of the first shoulder 441 (FIG. 17) of the die 44 was set to 0.05 mm, the radius of curvature Rp2 of the second shoulder 442 was set to 0.5 mm, the step height sh1 was set to 0.5 mm, and the width w1 was set to 0.5 mm. As a comparative example, an analysis was also performed in which the radius of curvature R1 of the shoulder 231a of the protrusion 231 (FIG. 2) of the plate holder 23 in the mold 20 (FIG. 1) was set to 0 mm, with the other conditions being the same as above.

[0131] As in the case of Figure 37, dots simulating the plating layer were placed on the plate surface, and their movement was tracked to estimate the plating coverage distance. As shown in Figure 39, the dimensions of the parts of the cut end surface covered with the plating layer along the thickness direction of the surface-plated metal plate were defined as d1 and d2, and the sum of these, d1 + d2, divided by the plate thickness T ((d1 + d2) / T) was defined as the plating coverage rate.

[0132] The results are shown in Figure 40. As shown in Figure 40, it was confirmed that the plating coverage could be improved by using mold 20, mold 30, or mold 40 compared to when the mold of the comparative example was used.

[0133] Although the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiments, and the above-described embodiments can be appropriately modified and carried out within the scope of the invention. [Explanation of symbols]

[0134] 10 Metal plate (surface coated metal plate) 10a Plating layer (coating layer) 11, 12, 13, 14, 15, 16 Metal parts 111, 121, 131 Cut end surface 111a, 121a, 131a shear surface 111b, 121b, 131b recessed surface 111c, 121c, 131c fracture surface 111d, 131d Dare 121d Second recessed surface 111e, 121e, 131e Who 121f Dare 119, 129, 139, 149, 159, 169 remainder 20, 30, 40, 50, 60 molds 21, 51 punch 22, 62, 72 Counter Pad 23, 53 Plate holder 231 Protrusion 231a Shoulder 24, 34, 44 dice

Claims

1. A method for manufacturing a metal member by punching a metal plate, the front and back surfaces of which are covered with a coating layer, using a die, The mold is Punch and a counter pad disposed opposite the punch with the metal plate interposed therebetween; a plate holder that is disposed on the punch side in the thickness direction of the metal plate and that is disposed to surround the punch in the in-plane direction of the metal plate; a die disposed on the counter pad side in the thickness direction of the metal plate and surrounding the counter pad in the in-plane direction of the metal plate, the plate holder has a protrusion on the inner periphery of a surface facing the metal plate, The protrusion of the plate holder has a shoulder portion with a curvature radius R1 on the inner peripheral side, The radius of curvature R1 is 0.10 times or more the thickness of the metal plate, The manufacturing method includes: a step of pressing the protrusion of the plate holder into the metal plate; and a step of bringing the punch and the die close together to punch out the metal plate.

2. The method for manufacturing a metal member according to claim 1, the die has a protrusion on the inner periphery of the surface facing the metal plate, The protrusion of the die has a shoulder portion with a curvature radius R2 on the inner peripheral side, The radius of curvature R2 is 0.10 times or more the thickness of the metal plate, A method for manufacturing a metal member, wherein in the step of pressing the protrusions of the plate holder into the metal plate, the protrusions of the die are further pressed into the metal plate.

3. The method for manufacturing a metal member according to claim 1, The die has a two-step shoulder on the inner periphery side, The two-stage shoulder portion is a first shoulder; a second shoulder portion that is located farther from the metal plate than the first shoulder portion in the thickness direction of the metal plate and closer to the counter pad than the first shoulder portion in the in-plane direction of the metal plate, A method for manufacturing a metal member, wherein the radius of curvature Rp2 of the second shoulder portion is 0.10 times or more the thickness of the metal plate.

4. A method for manufacturing a metal member by punching a metal plate, the front and back surfaces of which are covered with a coating layer, using a die, The mold is Punch and a counter pad disposed opposite the punch with the metal plate interposed therebetween; a plate holder that is disposed on the punch side in the thickness direction of the metal plate and that is disposed to surround the punch in the in-plane direction of the metal plate; a die disposed on the counter pad side in the thickness direction of the metal plate and surrounding the counter pad in the in-plane direction of the metal plate, the punch has a protrusion on a peripheral edge of a surface facing the metal plate, The protrusion of the punch has a shoulder on the outer periphery with a radius of curvature R3, The radius of curvature R3 is 0.10 times or more the thickness of the metal plate, The manufacturing method includes: pressing the protrusion of the punch into the metal plate; and a step of bringing the counter pad and the plate holder close together to punch out the metal plate.

5. The method for manufacturing a metal member according to claim 4, the counter pad has a protrusion on a peripheral edge of a surface facing the metal plate, The protrusion of the counter pad has a shoulder portion with a curvature radius R4 on the outer periphery side, The radius of curvature R4 is 0.10 times or more the thickness of the metal plate, A method for manufacturing a metal member, wherein in the step of pressing the protruding portion of the punch into the metal plate, the protruding portion of the counter pad is further pressed into the metal plate.

6. The method for manufacturing a metal member according to claim 4, the counter pad has a two-step shoulder portion on the peripheral edge of the surface facing the metal plate, The two-stage shoulder portion is a first shoulder; a second shoulder portion that is located farther from the metal plate than the first shoulder portion in the thickness direction of the metal plate and closer to the die than the first shoulder portion in the in-plane direction of the metal plate, A method for manufacturing a metal member, wherein the radius of curvature Rp4 of the second shoulder portion is 0.10 times or more the thickness of the metal plate.

7. Punch and a counter pad disposed opposite the punch with a metal plate as a workpiece sandwiched therebetween; a plate holder that is disposed on the punch side in the thickness direction of the metal plate and that is disposed to surround the punch in the in-plane direction of the metal plate; a die disposed on the counter pad side in the thickness direction of the metal plate and surrounding the counter pad in the in-plane direction of the metal plate, the plate holder has a protrusion on the inner periphery of a surface facing the metal plate, The protrusion of the plate holder has a shoulder portion with a curvature radius R1 on the inner peripheral side, The mold, wherein the radius of curvature R1 is 0.2 mm or more.

8. The mold according to claim 7, the die has a protrusion on the inner periphery of the surface facing the metal plate, The protrusion of the die has a shoulder portion with a curvature radius R2 on the inner peripheral side, The mold, wherein the radius of curvature R2 is 0.2 mm or more.

9. The mold according to claim 7, The die has a two-step shoulder on the inner periphery side, The two-stage shoulder portion is a first shoulder; a second shoulder portion that is located farther from the metal plate than the first shoulder portion in the thickness direction of the metal plate and closer to the counter pad than the first shoulder portion in the in-plane direction of the metal plate, The mold, wherein the radius of curvature Rp2 of the second shoulder portion is 0.1 mm or more.

10. Punch and a counter pad disposed opposite the punch with a metal plate as a workpiece sandwiched therebetween; a plate holder that is disposed on the punch side in the thickness direction of the metal plate and that is disposed to surround the punch in the in-plane direction of the metal plate; a die disposed on the counter pad side in the thickness direction of the metal plate and surrounding the counter pad in the in-plane direction of the metal plate, the punch has a protrusion on a peripheral edge of a surface facing the metal plate, The protrusion of the punch has a shoulder on the outer periphery with a radius of curvature R3, The mold, wherein the radius of curvature R3 is 0.2 mm or more.

11. The mold according to claim 10, the counter pad has a protrusion on a peripheral edge of a surface facing the metal plate, The protrusion of the counter pad has a shoulder portion with a curvature radius R4 on the outer periphery side, The mold, wherein the radius of curvature R4 is 0.2 mm or more.

12. The mold according to claim 10, the counter pad has a two-step shoulder portion on the peripheral edge of the surface facing the metal plate, The two-stage shoulder portion is a first shoulder; a second shoulder portion that is located farther from the metal plate than the first shoulder portion in the thickness direction of the metal plate and closer to the die than the first shoulder portion in the in-plane direction of the metal plate, The mold, wherein the radius of curvature Rp4 of the second shoulder portion is 0.1 mm or more.

13. A metal member formed by punching a metal plate having front and back surfaces covered with coating layers, the metal member having a cut end surface formed by the punching process, The cut end surface is a shear surface; a recessed surface that is a curved surface having a shape that is convex toward the inside of the member, A metal member, wherein at least a portion of the recessed surface is covered with the coating layer.

14. The metal member according to claim 13, The cutting end surface further includes a sag adjacent to the recessed surface, A metal member in which 50% or more of the combined area of ​​the recessed surface and the sag is covered with the coating layer.

15. The metal member according to claim 13 or 14, The cut end surface further includes a second sag adjacent to the shear surface; A metal member, wherein the shear surface is located between the recessed surface and the second sag in the thickness direction of the metal member.

16. The metal member according to claim 13 or 14, The cut end surface further includes a second recessed surface that is a curved surface having a shape that is convex toward the inside of the member, and a second sag adjacent to the second recessed surface, A metal member, wherein the shear surface is located between the recessed surface and the second recessed surface in the thickness direction of the metal member.

17. The metal member according to claim 13 or 14, A metal member, wherein a sinkage, which is the distance between a tangent to the shear surface and the deepest position of the recessed surface, is 0.01 to 0.10 times the thickness of the metal member.

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