Processing device, method for manufacturing metal member, and metal member

Abstract

Provided is a processing device with which it is possible to manufacture a metal member having exceptional corrosion resistance at a cut end surface thereof. A processing device (20) comprises a punch (21) and a die (22) that are positioned on one sheet-thickness-direction side and the other sheet-thickness-direction side, respectively, of a metal sheet (10) that is a workpiece. The punch (21) and the die (22) each have an end surface (211, 221) and a side surface (212, 222). The punch (21) and the die (22) are positioned such that the end surface (211) of the punch (21) and the end surface (221) of the die (22) do not overlap in plan view. At least one of the side surface (212) of the punch (21) and the side surface (222) of the die (22) includes an inclined section (212a) of which the surface is inclined so as to face toward the metal sheet (10) and which is formed so as not to overlap the other of the punch (21) and the die (22) in plan view, the angle θ formed by the sheet thickness direction and the surface of the inclined section (212a) being 15° or greater.

Description

[Technical field]

[0001] The present invention relates to a processing device, a method for manufacturing a metal member, 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, the raw material, cold-rolled steel sheet or hot-rolled steel sheet, is pressed and then painted or plated. However, adding a painting process or plating process after press working increases the work time and cost.

[0003] To solve this problem, it is conceivable to use plated steel sheets as a material for press working. However, when plated steel sheets are subjected to press working involving cutting, such as punching, the plated layer is separated at the cut end surface, exposing the steel base. If the steel base is left exposed at the cut end surface, corrosion will occur from the cut end surface. Therefore, a process of plating the cut end surface where the steel base is exposed is required, which increases work time and costs.

[0004] JP 2017-87294 A discloses a cutting method in which the clearance between the die and the punch is 1 to 20% of the thickness of the surface-treated steel sheet, and a die having a radius of curvature of 0.12 or more times the thickness of the surface-treated steel sheet is used to cut the surface-treated steel sheet, on the shoulder of at least one of the die or punch.

[0005] JP 2009-287082 A describes a cutting method for cutting a zinc-based plated steel sheet using a mold consisting of a die, a punch, and a die holder, in which one of the shoulders of the die or the punch that faces 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 is at a right angle with the shoulder of the die holder, the sides of the die and the die holder are aligned, and the clearance between the die and the punch is set to 1.0% or less of the thickness of the steel sheet. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-87294 A [Patent Document 2] JP 2009-287082 A [Patent Document 3] JP 2020-32437 A [Patent Document 4] JP 2006-263755 A Summary of the Invention [Problem to be solved by the invention]

[0007] In the processing conditions of JP 2017-87294 A, the occurrence of fracture surfaces is suppressed and the length of the sheared surface can be expanded under narrow clearance conditions, but the plating layer formed on the obtained sheared surface is limited to a small area. On the other hand, under wide clearance conditions, the length of the sheared surface is expanded compared to conventional conditions, but a certain amount of fracture surfaces are generated. Therefore, corrosion may occur on the sheared surface that is not covered with the plating layer or on the fractured surface.

[0008] Under the processing conditions of JP 2009-287082 A, the occurrence of fracture surfaces can be suppressed and the length of the sheared surfaces can be increased, but the plating layer formed on the obtained sheared surfaces is limited to a small area.

[0009] The object of the present invention is to provide a processing apparatus capable of producing a metal component having excellent corrosion resistance at its cut end surface, a method for producing 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]

[0010] A processing apparatus according to one embodiment of the present invention is provided with a punch and a die arranged on one and the other sides in the thickness direction of a metal plate, which is a workpiece, and shears the metal plate by moving at least one of the punch and the die in the thickness direction so that the punch and the die approach each other, wherein each of the punch and the die has an end face and a side face, the punch and the die are arranged so that the end face of the punch and the end face of the die do not overlap in a planar view, at least one of the side face of the punch and the side face of the die is inclined so that the surface faces toward the metal plate and includes an inclined portion formed so as to overlap with the other of the punch and the die in a planar view, and the angle between the surface of the inclined portion and the thickness direction is 15° or more.

[0011] A method for manufacturing a metal component according to one embodiment of the present invention includes a step of shearing a metal plate having a plating layer on its surface, using the above-mentioned processing apparatus.

[0012] A metal component according to one embodiment of the present invention is a metal component made of a metal plate having a plating layer on its surface, and has an inclined surface on its end face whose dimension in the plate thickness direction is 60% or more of the plate thickness and whose angle with the plate thickness direction is 15° or more, and at least a portion of the inclined surface is covered with the plating layer. Effect of the Invention

[0013] According to the present invention, a metal component having excellent corrosion resistance at its cut end faces can be obtained. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration of a processing apparatus according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view that typically illustrates shear processing of a metal plate by the processing apparatus of FIG. [Diagram 3] FIG. 3 is a perspective view of a metal member according to an embodiment of the present invention. [Figure 4]FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] FIG. 5 is a cross-sectional view that illustrates a schematic configuration of a processing apparatus according to a second embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view that typically illustrates shearing of a metal plate by the processing apparatus of FIG. [Figure 7] FIG. 7 is a perspective view of a metal component according to an embodiment of the present invention. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] FIG. 9 is a cross-sectional view that illustrates a schematic configuration of a processing apparatus according to a third embodiment of the present invention. [Figure 10] FIG. 10 is a cross-sectional view that typically illustrates shearing of a metal plate by the processing apparatus of FIG. [Figure 11] FIG. 11 is a cross-sectional view that illustrates a schematic configuration of a processing apparatus according to a fourth embodiment of the present invention. [Figure 12] FIG. 12 is a perspective view of a metal member according to an embodiment of the present invention. [Figure 13] FIG. 13 is a contour map showing the distribution of stress in a metal plate during processing, calculated by the finite element method. [Figure 14] FIG. 14 is a cross-sectional photograph of a metal plate immediately before it broke. [Figure 15] FIG. 15 is a graph showing the relationship between the angle θ and the height H and the limit pressing depth for punching. [Figure 16] FIG. 16 shows a cross-sectional photograph of the processed metal plate and the results of elemental analysis of the end surface. [Figure 17] FIG. 17 is a graph showing the relationship between the angle θ and the height H and the plating remaining rate. [Figure 18] FIG. 18 shows photographs of the metal plate before and after the atmospheric exposure test. [Figure 19] FIG. 19 shows a cross-sectional photograph of the processed metal plate and the results of elemental analysis of the end surface. [Figure 20] FIG. 20 is a graph showing the relationship between the angle θ and the height H and the plating remaining rate. [Figure 21] FIG. 21 shows photographs of the metal plate before and after the atmospheric exposure test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the embodiments 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 their description will not be repeated. The dimensional ratios between the components shown in each drawing do not necessarily represent the actual dimensional ratios.

[0016] [First embodiment] [Processing equipment] 1 is a cross-sectional view showing a schematic configuration of a processing device 20 according to a first embodiment of the present invention. The processing device 20 is a die used for shearing a metal plate. The processing device 20 is particularly suitable for, but not limited to, shearing a metal plate having a plating layer on its surface (hereinafter, sometimes referred to as a "surface-plated metal plate"). The shearing process includes, but is not limited to, drilling, punching, cutting, and the like.

[0017] The processing device 20 includes a punch 21, a die 22, and a plate holder 23. The punch 21 and the die 22 are arranged on one side and the other side in the plate thickness direction of the metal plate 10, which is the workpiece. The processing device 20 shears the metal plate 10 by moving at least one of the punch 21 and the die 22 in the plate thickness direction by a press machine (not shown) so that the punch 21 and the die 22 approach each other. The plate holder 23 is arranged to face the die 22 with the metal plate 10 sandwiched therebetween, and suppresses the occurrence of warping of the metal plate 10 when the metal plate 10 is sheared and the occurrence of biting into the punch 21 when the punch 21 is pulled out.

[0018] Hereinafter, the direction parallel to the plate thickness direction may be referred to as the z direction, and the plane perpendicular to the z direction may be referred to as the xy plane. Also, the dimension in the plate thickness direction may be referred to as the "height."

[0019] The punch 21 has an end face 211 and a side face 212 continuous therewith. Similarly, the die 22 has an end face 221 and a side face 222 continuous therewith. The end face 211 comes into contact with the metal sheet 10 before the side face 212 does during processing, and the end face 221 comes into contact with the metal sheet 10 before the side face 222 does during processing.

[0020] It is preferable that the end faces 211 and 221 are perpendicular to the plate thickness direction. That is, it is preferable that the end faces 211 and 221 are parallel to the metal plate 10.

[0021] A clearance CL of a predetermined size is provided between the contour of the end face 211 and the contour of the end face 221 in a plan view. As a result, the punch 21 and the die 22 are arranged so that the end face 211 and the end face 221 do not overlap in a plan view. Here, "plan view" means that the object is viewed straight from one side in the plate thickness direction. The end face 211 and the end face 221 "do not overlap in a plan view" means that the end face 211 and the end face 221 do not overlap when projected onto a plane (xy plane) perpendicular to the plate thickness direction.

[0022] According to this configuration, the punch 21 and the die 22 can be brought close to each other until the distance in the plate thickness direction between the end face 211 and the end face 221 becomes equal to or less than zero. This makes it possible to more reliably cut the metal plate 10. In addition, it is possible to prevent the punch 21 and the die 22 from colliding with each other when the metal plate 10 is cut.

[0023] End face 211 and end face 221 can have any shape as long as they do not overlap in a plan view. The planar shape of end face 211 (shape in the xy plane) is, for example, circular, elliptical, rectangular, etc. The planar shape of end face 221 is, for example, a shape with a circular hole, a shape with an elliptical hole, a shape with a rectangular hole, etc. The planar shape of end face 221 is preferably formed so that the clearance CL is constant.

[0024] The planar shape of the end face 211 is preferably circular. The planar shape of the end face 221 is preferably a shape with a circular hole. In the case of a circular shape, the material is constrained in the circumferential direction, so that uniform deformation can be imparted. As a result, when the surface-plated metal sheet is sheared, excellent corrosion resistance can be imparted to the end face.

[0025] The size (area) of the end face 211 is not particularly limited. However, if the end face 211 is too small, it may not be able to withstand the load during processing and may be damaged. The size of the end face 211 is preferably equivalent to a circle with an outer diameter of 10 mm (area of ​​about 78 mm 2 On the other hand, if the end face 211 is too large, the load required to press the metal plate 10 by the inclined portion 212a described below increases, which may require the use of a press machine with higher performance.

[0026] The punch 21 and the die 22 may be solid or hollow. The punch 21 and the die 22 are preferably solid. A compressive stress is applied to the punch 21 and the die 22 when the metal sheet 10 is pressed by the inclined portion 212a described later. Therefore, the punch 21 and the die 22 preferably have a strength sufficient to withstand the stress.

[0027] The side surface 212 of the punch 21 is inclined so that the surface faces the metal plate 10, and includes an inclined portion 212a formed so as to overlap the die 22 in a plan view.

[0028] Here, "inclined so that the surface faces the direction of the metal plate 10" means that the normal line extending outward from the surface of the inclined portion 212a faces the metal plate 10. More specifically, when the side on which the punch 21 is arranged as viewed from the metal plate 10 is taken as the positive z direction and the side on which the die 22 is arranged is taken as the negative z direction, this means that the z direction component of the normal line extending outward from the surface of the inclined portion 212a is negative.

[0029] Further, the inclined portion 212a "overlaps in a plan view" with the die 22 means that when the inclined portion 212a and the die 22 are projected onto a plane (xy plane) perpendicular to the plate thickness direction, the inclined portion 212a and the die 22 overlap. In this case, it is not necessary for the entire inclined portion 212a to overlap with the die 22, and it is sufficient that at least a part of the inclined portion 212a overlaps with the die 22.

[0030] According to this configuration, when the punch 21 and the die 22 are brought close to each other, the metal sheet 10 is sandwiched between the inclined portion 212a and the die 22, and a compressive stress is applied to the metal sheet 10. This compressive stress causes the metal sheet 10 to deform into a specific shape, which will be described later.

[0031] The angle θ between the surface of the inclined portion 212a and the plate thickness direction is equal to or greater than 15°. The preferred range of the angle θ will be described later.

[0032] In relation to the thickness of the metal plate 10, the height HT of the inclined portion 212a is preferably 60% or more of the thickness of the metal plate 10. The height HT of the inclined portion 212a is preferably 1 mm or more, more preferably 3 mm or more, and even more preferably 5 mm or more.

[0033] The side surface 212 of the punch 21 includes, in addition to the inclined portion 212a, a tip portion 212b that is continuous with the inclined portion 212a, is formed at an end portion closer to the metal plate 10 in the plate thickness direction, and has a surface that is approximately parallel to the plate thickness direction. The angle between the surface of the tip portion 212b and the plate thickness direction is preferably 5.0° or less, preferably 3.0° or less, more preferably 1.0° or less, and even more preferably 0.5° or less.

[0034] The tip portion 212b can apply a larger shear stress to the metal plate 10. This makes it possible to more reliably divide the metal plate 10. However, depending on the size of the clearance CL and the material of the metal plate 10, the metal plate 10 can be divided even if the tip portion 212b is not present. Therefore, it is not essential that the side surface 212 includes the tip portion 212b, and the side surface 212 does not have to include the tip portion 212b.

[0035] Furthermore, the presence of the tip portion 212b clarifies the size of the clearance CL, so that the punch 21 and the die 22 can be aligned more reliably. If the tip portion 212b exists, this effect can be obtained even if the height H of the tip portion 212b is small. In relation to the thickness of the metal sheet 10, the lower limit of the height H is preferably 1% of the thickness of the metal sheet 10, more preferably 2%, and even more preferably 3%. The lower limit of the height H is preferably 0.03 mm, more preferably 0.06 mm, and even more preferably 0.09 mm.

[0036] On the other hand, if the height H of the tip portion 212b is too large, the metal sheet 10 may be cut before the inclined portion 212a comes into contact with the metal sheet 10. Also, the smaller the height H, the later the timing at which the metal sheet 10 is cut tends to be. As will be described in detail later, when a surface-plated metal sheet is sheared, the later the timing at which the metal sheet 10 is cut, the more excellent corrosion resistance can be imparted to the end face.

[0037] Therefore, from the viewpoint of imparting excellent corrosion resistance to the manufactured metal component, the smaller the height H of the tip portion 212b, the more preferable. In relation to the thickness of the metal plate 10, the upper limit of the height H is preferably 50% of the thickness of the metal plate 10, more preferably 40%, and even more preferably 30%. The upper limit of the height H is preferably 1.6 mm, more preferably 1.2 mm, and even more preferably 0.8 mm.

[0038] The side surface 222 of the die 22 is approximately parallel to the plate thickness direction. The side surface 222 of the die 22 does not include an inclined portion like the inclined portion 212a of the side surface 212 of the punch 21.

[0039] [Metal component manufacturing method] Next, a method for manufacturing a metal component will be described. The method for manufacturing a metal component according to this embodiment includes a step of shearing a surface-plated metal sheet using a processing device 20.

[0040] The base material of the surface-plated metal sheet is, but is not limited to, steel, copper, a copper alloy, aluminum, an aluminum alloy, etc. The manufacturing method according to this embodiment is particularly suitable when the base material of the surface-plated metal sheet is steel, that is, when the surface-plated metal sheet is a plated steel sheet. This is because steel is prone to rust, and the advantage of imparting corrosion resistance according to this embodiment is great. The plated steel sheet is, for example, a Zn-based plated steel sheet, an Al-based plated steel sheet, etc.

[0041] The surface-plated metal sheet is more preferably a Zn-plated steel sheet. The Zn-plating has a sacrificial corrosion protection effect on the base material steel sheet. Therefore, it is possible to suppress corrosion from the exposed part of the base material at the cut end surface by shearing, and to further increase the corrosion resistance of the manufactured metal member. The Zn-plating includes, but is not limited to, hot-dip galvanizing, alloyed hot-dip galvanizing, Zn-Ni-based plating, Zn-Al-based plating, Zn-Mg-based plating, Zn-Al-Mg-based plating, and the like.

[0042] The thickness of the surface-plated metal sheet is preferably 0.2 to 9 mm. If the sheet thickness is too thick, the proportion of fracture surfaces after shear processing may increase, and the effect of improving corrosion resistance may be reduced. The upper limit of the sheet thickness of the surface-plated steel sheet is more preferably 6 mm. On the other hand, if the sheet thickness is sufficiently thin, rust generated on the end surface is not noticeable, so the benefit of improving corrosion resistance is small. The lower limit of the sheet thickness of the surface-plated steel sheet is more preferably 1.0 mm.

[0043] The thickness of the plating layer of the surface-plated metal sheet is preferably 15 μm or more. If the plating layer is too thin, the plating layer that can cover the end surface may be exhausted, and the end surface may not be able to be provided with corrosion resistance. 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.

[0044] 1 and 2, a process of shearing a metal sheet 10 (surface-plated metal sheet) using a processing device 20 will be described. As described in the explanation of the configuration of the processing device 20, the punch 21 and the die 22 are placed on one side and the other side of the metal sheet 10 in the sheet thickness direction. At least one of the punch 21 and the die 22 is moved in the sheet thickness direction by a press machine (not shown) so that the punch 21 and the die 22 approach each other. At this time, as shown in FIG. 2, an inclined surface 111 is formed on the metal sheet 10 by the inclined portion 212a of the punch 21.

[0045] Thereafter, the punch 21 and the die 22 are brought even closer to each other, thereby dividing the metal sheet 10 into the first portion 11 and the second portion 12. At this time, a cut surface 112 is formed on the end face of the first portion 11, continuing from the inclined surface 111. The cut surface 112 includes a sheared surface and a fractured surface. However, depending on the processing conditions, the cut surface 112 may be only one of the sheared surface and the fractured surface, or the cut surface 112 may not be formed at all.

[0046] In this embodiment, the first portion 11 having the inclined surface 111 becomes the product (metal member). The inclined surface 111 is a surface formed by deforming the surface of the metal sheet 10, which is a surface-plated metal sheet, and therefore has a plating layer on at least a portion thereof. Although the plating layer of the inclined surface 111 may be partially peeled off due to sliding with the punch 21, etc., the inclined surface 111 is still more likely to be covered with the plating layer than the sheared surface or fractured surface. In addition, the thickness of the plating layer covering the inclined surface 111 is not significantly reduced from the thickness of the plating layer of the surface-plated metal sheet.

[0047] The shear surface may be covered with a plating layer because the plating layer on the surface of the metal sheet 10 wraps around the shear surface, but may not be covered with a plating layer. The fracture surface is usually not covered with a plating layer.

[0048] According to the processing apparatus 20 and the manufacturing method of the metal component of the present embodiment, the end face of the manufactured metal component includes an inclined surface, so that the proportion of the end face covered with the plating layer can be increased. This makes it possible to obtain a metal component with excellent corrosion resistance at the cut end face.

[0049] The angle θ (FIG. 1) between the surface of the inclined portion 212a of the punch 21 and the plate thickness direction is 15° or more. The larger the angle θ, the later the timing at which the metal plate 10 is divided tends to be. "The timing at which the metal plate 10 is divided is delayed" means that the metal plate 10 is not divided unless the punch 21 and the die 22 approach each other. The later the timing at which the metal plate 10 is divided, the smaller the height of the cut surface 112 becomes, and the larger the ratio of the height of the inclined surface 111 to the plate thickness of the metal plate 10 becomes. Therefore, the larger the angle θ, the larger the ratio of the end surface covered by the plating layer can be. The lower limit of the angle θ is preferably 20°, and more preferably 30°.

[0050] On the other hand, the larger the angle θ, the larger the load required to form the inclined surface 111. In addition, the angle θ coincides with the inclination angle of the inclined surface 111, but an increase in the angle θ means that the projection area of ​​the formed inclined surface 111 onto the xy plane increases. The upper limit of the angle θ is preferably 60°, more preferably 50°, and even more preferably 45°.

[0051] As described in the explanation of the configuration of the processing device 20, the smaller the height H of the tip 212b of the punch 21, the later the timing at which the metal sheet 10 is cut tends to be. The later the timing at which the metal sheet 10 is cut, the smaller the height of the cut surface 112 becomes, and the greater the ratio of the height of the inclined surface 111 to the thickness of the metal sheet 10 becomes. Therefore, the smaller the height H, the greater the ratio of the end surface covered by the plating layer can be.

[0052] [Metal parts] As described above, in the manufacturing method of the metal member according to the present embodiment, the first portion 11 in Fig. 2 becomes the product (metal member). The first portion 11 is the remaining portion after the second portion 12 is punched out from the metal plate 10. Hereinafter, the first portion 11 will be referred to as the metal member 11.

[0053] Fig. 3 is a perspective view of the metal member 11, and Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3. Fig. 3 illustrates a case in which the contour of the hole in the metal member 11 is circular, but this is an example. As described in the explanation of the configuration of the processing device 20, the end face 211 of the punch 21 and the end face 221 of the die 22 may have any planar shape. Therefore, the contour of the hole in the metal member 11 may also have any shape.

[0054] The metal member 11 has one inclined surface 111 on an end surface. The metal member 11 further has a cut surface 112 that is continuous with the inclined surface 111 and is formed at an end portion on the side where the dimension of the metal member 11 becomes larger in the plate thickness direction due to the inclined surface 111. As shown in Fig. 4, the cut surface 112 includes a sheared surface 112a whose surface is approximately parallel to the plate thickness direction, and a fractured surface 112b. The sheared surface 112a and the fractured surface 112b are formed in this order from the side closer to the inclined surface 111.

[0055] The surfaces of the metal member 11 except for the end faces are covered with the plating layer 10a. Of the end faces of the metal member 11, at least a portion of the inclined surface 111 is covered with the plating layer 10a. The sheared surface 112a may or may not be covered with the plating layer 10a. The fractured surface 112b is usually not covered with the plating layer 10a. FIG. 4 illustrates, as an example, a case in which the entire inclined surface 111 and a portion of the sheared surface 112a are covered with the plating layer 10a, and the base material is exposed at the remaining portion of the sheared surface 112a and the fractured surface 112b.

[0056] The height Ht of the inclined surface 111 is 60% or more of the plate thickness T. The greater the ratio of the height Ht to the plate thickness T, the higher the corrosion resistance of the end face. The lower limit of the height Ht is preferably 70% of the plate thickness T, more preferably 80%, and even more preferably 90%. In order to increase the height Ht of the inclined surface 111, for example, the angle θ between the surface of the inclined portion 212a of the punch 21 (FIG. 1) and the plate thickness direction may be increased, or the height H of the tip portion 212b of the punch 21 may be reduced.

[0057] The entire end face of the metal member 11 may be an inclined surface 111. In other words, the metal member 11 does not need to have a cut surface 112. On the other hand, when the metal member 11 has the cut surface 112, the metal member 11 can be manufactured more stably. The lower limit of the height of the cut surface 112 is preferably 3% of the plate thickness T, and more preferably 5%.

[0058] Even if a portion of the cut surface 112 is not covered with the plating layer 10a, the metal member 11 has good corrosion resistance because at least a portion of the inclined surface 111 is covered with the plating layer 10a. In particular, when the surface-plated metal sheet is a Zn-based plated steel sheet, the Zn-based plating layer has a sacrificial corrosion protection effect on the base material, that is, the steel sheet, so that corrosion resistance can be ensured even if a certain proportion of the base material is exposed.

[0059] The angle θ between the inclined surface 111 and the plate thickness direction is 15° or more. The lower limit of the angle θ is preferably 20°, and more preferably 30°. The upper limit of the angle θ is preferably 60°, and more preferably 50°, and more preferably 45°.

[0060] The angle θ between the inclined surface 111 and the thickness direction can be controlled by the shape of the punch 21 (FIG. 1). The angle θ between the inclined surface 111 and the thickness direction coincides with the angle θ between the inclined portion 212a and the thickness direction.

[0061] The plating layer 10a covering at least a part of the inclined surface 111 is derived from the workpiece material. Therefore, the plating layer 10a covering at least a part of the inclined surface 111 has exactly the same components as the plating layer 10a covering the surface other than the end face.

[0062] The proportion of the area of ​​the surface of the inclined surface 111 that is covered with the plating layer 10a is preferably 60% or more. It is more preferable that the entire inclined surface 111 is covered with the plating layer 10a.

[0063] The thickness of the plating layer 10a covering the inclined surface 111a is preferably 25 to 90% of the thickness of the plating layer 10a covering the surfaces other than the end faces.

[0064] 4 illustrates a case where an inclined surface 111 and a cut surface 112 are formed on an end surface of a metal member, and the cut surface 112 includes a sheared surface 112a and a fractured surface 112b, but the cut surface 112 does not have to include either the sheared surface 112a or the fractured surface 112b. Also, as described above, the metal member 11 does not have to have a cut surface 112.

[0065] The above describes the processing apparatus 20 according to the first embodiment of the present invention, the method for manufacturing a metal member, and the metal member 11. According to this embodiment, a metal member having excellent corrosion resistance at its cut end faces can be obtained.

[0066] [Second embodiment] [Processing equipment] 5 is a cross-sectional view showing a schematic configuration of a processing apparatus 30 according to a second embodiment of the present invention. The processing apparatus 30 is different from the processing apparatus 20 according to the first embodiment (FIG. 1) in the configuration of the punch and the die. The processing apparatus 30 includes a punch 31 instead of the punch 21 of the processing apparatus 20, and a die 32 instead of the die 22 of the processing apparatus 20.

[0067] The punch 31 has an end face 311 and a side face 312 continuous therefrom. Similarly, the die 32 has an end face 321 and a side face 322 continuous therefrom. In this embodiment as well, a clearance CL of a predetermined size is provided between the contour of the end face 311 and the contour of the end face 321 in a plan view. As a result, the punch 31 and the die 32 are arranged so that the end face 311 and the end face 321 do not overlap in a plan view.

[0068] The side surface 312 of the punch 31 is approximately parallel to the plate thickness direction.

[0069] A side surface 322 of the die 32 is inclined so that the surface faces the metal plate 10, and includes an inclined portion 322a formed so as to overlap the punch 31 in a plan view.

[0070] Here, "inclined so that the surface faces the metal plate 10" means, more specifically, that when the side on which the punch 31 is located is viewed from the metal plate 10 as being positive in the z direction and the side on which the die 32 is located as being negative in the z direction, the z direction component of the normal extending outward from the surface of the inclined portion 322a is positive.

[0071] Further, the inclined portion 322a "overlaps in a plan view" with the punch 31 means that when the inclined portion 322a and the punch 31 are projected onto a plane (xy plane) perpendicular to the plate thickness direction, the inclined portion 322a and the punch 31 overlap. In this case, it is not necessary for the entire inclined portion 322a to overlap with the punch 31, and it is sufficient that at least a part of the inclined portion 322a overlaps with the punch 31.

[0072] With this configuration, when the punch 31 and the die 32 are brought close to each other, the metal sheet 10 is sandwiched between the inclined portion 322a and the punch 31, and a compressive stress is applied to the metal sheet 10. This compressive stress causes the metal sheet 10 to deform into a specific shape.

[0073] The angle θ between the surface of the inclined portion 322a and the plate thickness direction, and the height HT of the inclined portion 322a are the same as in the first embodiment.

[0074] The side surface 322 of the die 32 includes, in addition to the inclined portion 322a, a tip portion 322b that is continuous with the inclined portion 322a, is formed at an end portion closer to the metal plate 10 in the plate thickness direction, and has a surface that is approximately parallel to the plate thickness direction. The height H of the tip portion 322b is the same as in the first embodiment. Also, as in the first embodiment, the side surface 322 does not have to include the tip portion 322b.

[0075] [Metal component manufacturing method] Next, a method for manufacturing a metal component will be described. The method for manufacturing a metal component according to this embodiment includes a step of shearing a surface-plated metal sheet using a processing device 30.

[0076] 5 and 6, a process of shearing a metal sheet 10 (surface-plated metal sheet) using a processing device 30 will be described. A punch 31 and a die 32 are placed on one side and the other side of the metal sheet 10 in the sheet thickness direction. At least one of the punch 31 and the die 32 is moved in the sheet thickness direction by a press machine (not shown) so that the punch 31 and the die 32 approach each other. At this time, as shown in FIG. 6, an inclined surface 141 is formed on the metal sheet 10 by the inclined portion 322a of the die 32.

[0077] Thereafter, the punch 31 and the die 32 are brought even closer to each other, thereby dividing the metal sheet 10 into the first portion 13 and the second portion 14. At this time, a cut surface 142 is formed on the end face of the second portion 14, continuing from the inclined surface 141. The cut surface 142 includes a sheared surface and a fractured surface. However, depending on the processing conditions, the cut surface 142 may be only one of the sheared surface and the fractured surface, or the cut surface 142 may not be formed at all.

[0078] In this embodiment, the second portion 14 becomes the product (metal member).

[0079] According to the processing apparatus 30 of this embodiment and the manufacturing method of the metal component of this embodiment, the end face of the manufactured metal component includes the inclined surface 141, so that the proportion of the end face covered with the plating layer can be increased. This makes it possible to obtain a metal component with excellent corrosion resistance at the cut end face.

[0080] [Metal parts] As described above, in the manufacturing method of the metal member according to the present embodiment, the second portion 14 in Fig. 6 becomes the product (metal member). The second portion 14 is a portion punched out from the metal plate 10. Hereinafter, the second portion 14 will be referred to as the metal member 14.

[0081] Fig. 7 is a perspective view of the metal member 14, and Fig. 8 is a cross-sectional view taken along line VIII-VIII in Fig. 7. Fig. 7 illustrates a case in which the outline of the metal member 14 is circular, but this is merely an example. The outline of the metal member 14 may be any shape.

[0082] The metal member 14 has one inclined surface 141 on an end surface. The metal member 14 further has a cut surface 142 that is continuous with the inclined surface 141 and is formed at an end portion on the side where the dimension of the metal member 14 becomes larger in the plate thickness direction due to the inclined surface 141. As shown in Fig. 8, the cut surface 142 includes a sheared surface 142a whose surface is approximately parallel to the plate thickness direction, and a fractured surface 142b. The sheared surface 142a and the fractured surface 142b are formed in this order from the side closer to the inclined surface 141.

[0083] The metal member 14, like the metal member 11 (FIG. 4), has a surface other than the end face covered with a plating layer 10a. Of the end faces of the metal member 14, at least a portion of the inclined surface 141 is covered with the plating layer 10a. The sheared surface 142a may or may not be covered with the plating layer 10a. The fractured surface 142b is usually not covered with the plating layer 10a. FIG. 8 illustrates, as an example, a case in which the entire inclined surface 141 and a portion of the sheared surface 142a are covered with the plating layer 10a, and the base material is exposed at the remaining portion of the sheared surface 142a and the fractured surface 142b.

[0084] The height Ht of the inclined surface 141, the height of the cut surface 142, the angle θ between the inclined surface 141 and the plate thickness direction, etc. are the same as those in the first embodiment. The height Ht of the inclined surface 141, the height of the cut surface 142, and the angle θ between the inclined surface 141 and the plate thickness direction can be controlled by the shape of the die 32 (FIG. 5). Also, as in the first embodiment, the cut surface 142 does not have to include either the shear surface 142a or the fracture surface 142b, and the metal member 14 does not have to have the cut surface 142.

[0085] The processing apparatus 30, the manufacturing method of the metal member, and the metal member 14 according to the second embodiment of the present invention have been described above. In the processing apparatus 20 according to the first embodiment (FIG. 1), the side surface 212 of the punch 21 is provided with the inclined portion 212a, whereas in the processing apparatus 30 according to the second embodiment (FIG. 5), the side surface 322 of the die 32 is provided with the inclined portion 322a. In the first embodiment, the inclined surface 111 is formed in the first portion 11 (FIG. 2), whereas in the second embodiment, the inclined surface 141 is formed in the second portion 14 (FIG. 6). However, in either case, the same effect can be obtained with respect to the corrosion resistance of the end face.

[0086] That is, in order to manufacture a metal component having an end face with excellent corrosion resistance, it is sufficient that at least one of the side face of the punch and the side face of the die includes an inclined portion, the surface of which is inclined toward the metal sheet and which is formed so as to overlap the other of the punch and the die in a plan view.

[0087] [Third embodiment] 9 is a cross-sectional view showing a schematic configuration of a processing apparatus 40 according to a third embodiment of the present invention. The processing apparatus 40 is different from the processing apparatus 20 (FIG. 1) according to the first embodiment in the configuration of the die. The processing apparatus 40 includes a die 32 instead of the die 22 of the processing apparatus 20. The die 32 is the same as that of the processing apparatus 30 (FIG. 5) according to the second embodiment.

[0088] In this embodiment as well, a clearance CL of a predetermined size in plan view is provided between the contour of the end face of the punch 21 and the contour of the end face of the die 32. As a result, the punch 21 and the die 32 are disposed so that their end faces do not overlap each other in plan view.

[0089] In this embodiment, inclined portions are provided on both the side surface of the punch 21 and the side surface of the die 32. As shown in Fig. 10, the metal plate 10 is divided into a first portion 11 having an inclined surface 111 and a second portion 14 having an inclined surface 141. In this embodiment, both the first portion 11 and the second portion 14 become products (metallic members).

[0090] The above describes the processing apparatus, the manufacturing method for a metal member, and the metal member according to the third embodiment of the present invention. This embodiment also provides a metal member having excellent corrosion resistance at its cut end faces.

[0091] [Fourth embodiment] [Processing equipment] 11 is a cross-sectional view showing a schematic configuration of a processing apparatus 50 according to a fourth embodiment of the present invention. The processing apparatus 50 is different from the processing apparatus 20 (FIG. 1) according to the first embodiment in the configuration of the punch and the die. The processing apparatus 50 includes a punch 51 instead of the punch 21 of the processing apparatus 20, and a die 52 instead of the die 22 of the processing apparatus 20.

[0092] The punch 51 has an end face 511 and a side face 512 continuous therefrom. Similarly, the die 52 has an end face 521 and a side face 522 continuous therefrom. A clearance CL of a predetermined size is provided between the contour of the end face 511 and the contour of the end face 521 in a plan view. This allows the punch 51 and the die 52 to be disposed such that their end faces do not overlap in a plan view.

[0093] The side surface 512 of the punch 51 includes an inclined portion 512a and a tip portion 512b, similarly to the first embodiment. The side surface 522 of the die 52 is approximately parallel to the plate thickness direction.

[0094] The punch 51 and the die 52 of the processing device 50 are different in planar shape from the punch 21 and the die 22 of the processing device 20 (FIG. 1).

[0095] 12 is a perspective view of a metal member 15 manufactured by the processing apparatus 50. The metal member 15 is obtained by cutting a metal plate along one of the directions (y direction) perpendicular to the plate thickness direction. The metal member 15 has an inclined surface 151 and a cut surface 152.

[0096] The inclined surface 151 and the cut surface 152 are similar to the inclined surface 111 and the cut surface 112 of the metal member 11 (FIG. 3) except for their planar shapes (shapes in the xy plane). Therefore, according to this embodiment as well, a metal member having excellent corrosion resistance at the cut end surfaces can be obtained.

[0097] 3 and 4 show an example in which the manufactured metal member is the remaining part after a predetermined shape is punched out of a metal plate (FIG. 3), and an example in which the part is punched out of the metal plate (FIG. 7). In addition, even in the case of cutting a metal plate to obtain a metal member as in this embodiment, the same effects as those of the previously described embodiment can be obtained. Note that the line cutting the metal plate 10 does not have to be a straight line.

[0098] In the above embodiment, a case has been described in which an inclined portion 512a is formed on the side surface 512 of the punch 51. However, instead of or in addition to the side surface 512 of the punch 51, the side surface 522 of the die 52 may include an inclined portion. EXAMPLES

[0099] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0100] A metal plate was punched using a processing device conforming to the configuration of the processing device 20 (Fig. 1). The shape of the end face 211 of the punch 21 was a circle with a diameter of 10.0 mm, and the clearance CL was 0.05 mm (the diameter of the hole in the die 22 was 10.1 mm). Prototypes were made by changing the angle θ to 15°, 30°, and 45°, and the height H to 0.1 mm, 0.4 mm, and 0.8 mm. The processed material had a yield strength of 366 MPa, a tensile strength of 454 MPa, an elongation of 31%, a plate thickness of 3.2 mm, and a coating weight of 275 g / m 2 The Zn-Al-Mg plated steel sheets were used.

[0101] As a comparative example, a metal plate was punched using a cylindrical punch having a diameter of 10.0 mm and a die having a cylindrical hole having a diameter of 10.8 mm.

[0102] Fig. 13 is a contour map showing the distribution of stress in the metal plate during processing, calculated by the finite element method. As shown in Fig. 13, in the processing device of the embodiment, the area pressed by the inclined part becomes highly stressed, and a stress concentration area occurs from the shoulder of the die parallel to the inclined part.

[0103] Fig. 14 is a cross-sectional photograph of a metal plate immediately before it breaks. From Fig. 14, it can be seen that when processing is performed using the processing device of the embodiment, the timing at which cracks occur is delayed (i.e., cracks do not occur unless the punch is pressed deeper) compared to when processing is performed using the processing device of the comparative example.

[0104] Fig. 15 is a graph showing the relationship between the angle θ and the height H and the punching limit indentation amount. The punching limit indentation amount is the indentation amount of the punch just before the metal plate breaks, and the larger the punching limit indentation amount is, the later the timing at which the metal plate breaks. From Fig. 15, it can be seen that the larger the angle θ is and the smaller the height H is, the larger the punching limit indentation amount is.

[0105] Figure 16 shows a cross-sectional photograph of the metal sheet after processing, and the results of elemental analysis of the edge surface. "Hp" in Figure 16 refers to the height of the edge surface where the plating layer remains (hereinafter referred to as "residual plating height Hp"). The residual plating height Hp was determined by measuring the edge surface of the metal sheet with an energy dispersive X-ray analyzer (EDX) and examining the distribution of Zn and Fe on the edge surface. In the metal sheet processed with a punch with an inclined part angle θ of 30°, there were areas near the bottom end of the inclined surface where the plating layer had peeled off. In the metal sheet processed with a punch with an inclined part angle θ of 45°, the plating layer remained, albeit intermittently, all the way to the bottom end of the inclined surface.

[0106] Fig. 17 is a graph showing the relationship between the angle θ and height H and the plating residual rate. The plating residual rate is the value obtained by dividing the plating residual height Hp by the plate thickness. From Fig. 17, it can be seen that the plating residual rate tends to increase as the angle θ increases and as the height H decreases. The plating residual rate of the metal plate processed by the processing device of the comparative example was a maximum of 20%.

[0107] FIG. 18 shows photographs of the metal plate before and after the atmospheric exposure test. The atmospheric exposure test was performed by cutting the metal plate in half, applying an anti-rust paint to the end faces other than the evaluation face (the end face formed by punching), and then placing the metal plate outdoors. The metal plate processed by the processing device of the comparative example had a wide and noticeable area of ​​red rust on the fracture surface three weeks after the start of exposure. In contrast, the metal plate processed by the processing device of the embodiment had a small amount of red rust three weeks after the start of exposure when the height H was 0.4 mm, and eight weeks after the start of exposure when the height H was 0.1 mm, but the area was small and difficult to see with the naked eye.

[0108] Next, a processing device similar to the configuration of the processing device 50 (FIG. 11) was used to perform shearing to cut the metal plate into a straight line. The clearance CL between the end face 511 of the punch 51 and the end face 521 of the die 52 was set to 0.05 mm. Prototypes were made by changing the angle θ to 15°, 30°, and 45°, and the height H to 0.1 mm, 0.4 mm, and 0.8 mm. The same Zn-Al-Mg-based plated steel sheet as used in the punching process was used as the processed material. As a comparative example, a shearing die with vertical sides (clearance of 0.4 mm) was used to perform shearing to cut the metal plate into a straight line.

[0109] A cross-sectional photograph of the processed metal sheet and the results of elemental analysis of the end surface are shown in Figure 19. In the metal sheet processed with a punch with an inclined part angle θ of 45°, the plating layer remained all the way to the bottom end of the inclined surface.

[0110] 20 is a graph showing the relationship between the angle θ and the height H and the plating remaining rate. The plating remaining rate of the metal sheet processed by the processing device of the comparative example was 18% at maximum.

[0111] Fig. 21 is a photograph of the metal plate before and after the atmospheric exposure test. The metal plate processed by the processing device of the comparative example had red rust on the fracture surface 6 weeks after the start of exposure. In contrast, the metal plate processed by the processing device of the example did not have red rust 6 weeks after the start of exposure.

[0112] Although the embodiment of the present invention has been described above, the above-mentioned embodiment is merely an example for carrying out the present invention. Therefore, the present invention is not limited to the above-mentioned embodiment, and the above-mentioned embodiment can be appropriately modified and carried out within the scope of the invention. [Explanation of symbols]

[0113] 10 metal plate 11 1st part (metal member) 111 Slope 112 Cut surface 112a Shear surface 112b Fracture surface 12 Part 2 13 Part 1 14 Second part (metal member) 141 Slope 142 Cut surface 142a Shear surface 142b Fracture surface 15 Metal parts 20, 30, 40, 50 processing equipment 21, 31, 51 punch 211, 311, 511 end face 212, 312, 512 Side 212a, 512a Slope 212b, 512b tip 22, 32, 52 Die 221, 321, 521 end face 222, 322, 522 Side 322a Slope 322b Tip

Claims

1. A processing device that includes a punch and a die disposed on one side and the other side in a plate thickness direction of a metal plate that is a workpiece, and that shears the metal plate by moving at least one of the punch and the die in the plate thickness direction so that the punch and the die approach each other, Each of the punch and the die has an end face and a side face, The punch and the die are arranged such that an end surface of the punch and an end surface of the die do not overlap in a plan view, At least one of the side surface of the punch and the side surface of the die includes an inclined portion that is inclined so that the surface faces the metal plate and is formed so as to overlap the other of the punch and the die in a plan view, The angle between the surface of the inclined portion and the plate thickness direction is 15° or more, A processing device in which at least one of the side of the punch and the side of the die includes, in addition to the inclined portion, a tip portion that is continuous with the inclined portion and is formed at an end portion closer to the metal plate in the plate thickness direction, and has a surface that is approximately parallel to the plate thickness direction.

2. The processing apparatus according to claim 1, A processing device, wherein the dimension of the tip portion in the plate thickness direction is 50% or less of the plate thickness of the metal plate.

3. The processing apparatus according to claim 1 or 2, The angle between the surface of the inclined portion and the plate thickness direction is 15 to 60 degrees.

4. A method for manufacturing a metal component, comprising the step of shearing a metal plate having a plating layer on a surface thereof, using the processing device according to claim 1 or 2.

5. A method for manufacturing a metal member according to claim 4, comprising the steps of: The method for producing a metal member, wherein the metal plate having a plating layer on its surface is a plated steel plate.

6. A method for manufacturing a metal member according to claim 5, The method for producing a metal member, wherein the plating layer is a Zn-based plating layer.

7. A metal member made of a metal plate having a plating layer on a surface thereof, The end surface has an inclined surface whose dimension in the thickness direction is 60% or more of the thickness and whose angle with the thickness direction is 15° or more; The inclined surface has a linear shape in a cross section parallel to the plate thickness direction, At least a portion of the inclined surface is covered with the plating layer.

8. The metal member according to claim 7, the end surface having the inclined surface is formed by shearing a surface-plated metal sheet that is a workpiece, A metal member, wherein the plating layer covering at least a portion of the inclined surface is derived from the workpiece.

9. The metal member according to claim 7 or 8, A metal member having a cut surface that is continuous with the inclined surface and is formed at an end portion on the side where the dimension of the metal member is increased in the plate thickness direction by the inclined surface, and that includes at least one of a shear surface and a fracture surface.

10. The metal member according to claim 9, The cut surface includes both the shear surface and the fracture surface, The fracture surface of the metal member is not covered with the plating layer.

11. The metal member according to claim 7 or 8, The metal member, wherein the metal plate having a plating layer on its surface is a plated steel plate.

12. The metal member according to claim 11, The metal member, wherein the plating layer is a Zn-based plating layer.

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