JP2023104790A - Finished article and finished article manufacturing method - Google Patents

Abstract

To provide a finished article which can suppress a red rust generating region and can suppress remaining burrs even if a plated steel plate with a plate thickness exceeding 2.0 mm is used as a raw material.SOLUTION: A finished article with a plated steel plate having a plating layer on a surface thereof as a raw material has a cut end part 13 along a plate thickness direction of the finished article. The cut end part 13 has an undercut 13c, a sheared surface 13d, a fracture surface 13e and a coining surface 13f in this order in a plate thickness direction T of the cut end part 13 toward an undersurface 13b side from a top face 13a side. A length W3 of the fracture surface 13e between the sheared surface 13d and the coining surface 13f in the plate thickness direction T of the cut end part 13 is more than 0 mm and 0.5 mm or less, and a ratio L1/W2 of a length L1 of the coining surface 13f in the plate thickness direction T and a distance W2 between the undersurface 13b of the cut end part 13 and an upper end of the fracture surface 13e is 0.95 or less.SELECTED DRAWING: Figure 2

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processed product made of a plated steel sheet having a plated layer on its surface and having a cut edge along the plate thickness direction of the processed product, and a method for manufacturing the same.

2. Description of the Related Art In recent years, the use of processed products made from plated steel sheets having a plated layer on their surfaces has been increasing as parts for devices such as automobiles and home appliances. By using a plated steel sheet as a material, it is possible to omit the plating process after forming the processed product and reduce the manufacturing cost. In addition, by omitting the plating process after molding, it is possible to avoid the deterioration of the dimensional accuracy of the parts due to the plating process after molding. Omitting the plating process after molding is particularly considered for parts that require high dimensional accuracy, such as motor cases.

When the plating treatment after forming is omitted, a region where the steel sheet substrate is exposed appears at the cut end of the processed product. Depending on the environment in which the processed product is placed, red rust may occur in areas where the steel plate base is exposed. Red rust deteriorates the appearance of the processed product.

As a method for improving the rust-preventing ability of the end portion of the processed product, for example, methods proposed in Patent Documents 1 and 2 listed below can be cited. In Patent Document 1, for a Zn-based plated steel sheet having a thickness of 2 mm or less, a die having a shoulder portion of a punch or die with a curvature radius of 0.1 to 0.5 times the thickness of the Zn-based plated steel sheet is used. A method has been proposed in which the sheared surface ratio of the punched end face after punching is 90% or more and the zinc coating rate of the sheared surface is 50% or more by punching with a steel plate.

Patent Document 2 proposes a method of obtaining a product having end faces with corrosion resistance by performing half-blanking of 60 to 95% of the plate thickness with a negative clearance and shearing by flat pressing from the opposite side of the half-blanking. .

Japanese Patent No. 5272518 Japanese Patent Application Laid-Open No. 2002-321021

In the method proposed in Patent Document 1, a steel plate with a thickness of 2 mm or less is targeted, and when a steel plate with a thickness of more than 2 mm is used as a material, the zinc coverage of the sheared surface becomes insufficient, suppressing the occurrence of red rust. is likely to become difficult. In addition, it is difficult to apply this method to a drawn product such as a motor case where the thickness increases at the end of the flange.

In addition, in the method proposed in Patent Document 2, half-blanking is performed with a negative clearance, and shearing is performed by flat pressing from the opposite side of the half-blanking. In addition, burrs like whiskers are likely to occur during flat pressing.

The present invention has been made to solve the above problems, and one of its purposes is to solve the red rust generation area even when a plated steel sheet having a thickness of more than 2.0 mm is used as a material. To provide a processed product capable of suppressing burrs and remaining burrs, and a method of manufacturing the same.

In one embodiment, the processed product according to the present invention is a processed product made of a plated steel sheet having a plating layer on the surface and having a cut edge along the thickness direction of the processed product, wherein the cut edge is , From the upper surface side to the lower surface side, it has sagging, sheared surface, fractured surface and coined surface in the plate thickness direction of the cut end, and the sheared surface and coined surface in the plate thickness direction of the cut end The length W3 of the fracture surface between them is more than 0 mm and 0.5 mm or less, and the length L1 of the coining surface in the plate thickness direction and the distance W2 between the lower surface of the cut end and the upper end of the fracture surface The ratio L1/W2 is 0.95 or less.

In another embodiment, the processed product according to the present invention is a processed product made of a plated steel sheet having a plating layer on the surface and having a cut edge along the thickness direction of the processed product, wherein the cut edge has a sag, a sheared surface, a fractured surface and a coined surface in order from the upper surface side to the lower surface side in the plate thickness direction of the cut end. The length W3 of the fractured surface between the It is below.

In one embodiment of the method for manufacturing a processed product according to the present invention, a plated steel sheet having a plating layer on the surface is used as a material, and processing is performed for manufacturing a processed product having a cut edge along the thickness direction of the processed product. A method for manufacturing an article, wherein a cutting step is performed to obtain a second element by performing a cutting process once using a die and a punch on a portion to be cut of a first element formed from a material, The portion to be cut is a plate-like portion including a portion to be a cut end portion, and the cut end portion of the second element is a sagging, a sheared surface, and a fracture surface in the plate thickness direction of the cut end portion of the second element. and a coining process of pressing the corner of the cut end of the second element on the fractured surface side against the pad to obtain a processed product with a coined surface formed on the corner. In the coining step, the amount of processing is adjusted so that the ratio L1/W1 of the length L1 of the coining surface in the plate thickness direction and the length W1 of the fracture surface of the second element in the plate thickness direction is 1.0 or less. Including a coining step of adjusting and coining, the cut end of the processed product is sagging, sheared surface, fractured surface, and It has a coining surface in order, and the length W3 of the fracture surface between the sheared surface and the coining surface in the plate thickness direction of the cut end of the processed product is more than 0 mm and 0.5 mm or less.

In another embodiment of the method for manufacturing a processed product according to the present invention, a plated steel sheet having a plating layer on the surface is used as a material for manufacturing a processed product having a cut edge along the thickness direction of the processed product. A method for manufacturing a processed product, wherein a cutting step is performed to obtain a second element by performing a cutting process once using a die and a punch on a portion to be cut of a first element formed from a material. , The portion to be cut is a plate-like portion including a portion to be the cut end portion, and the cut end portion of the second element is sagging, a sheared surface, and a fracture in the plate thickness direction of the cut end portion of the second element. A processed product having a coined surface formed on the corner is obtained by performing a cutting process having a cross section in order and a coining process in which the corner of the cut end of the second element on the fractured surface side is pressed against the pad. In the coining process to obtain, the amount of processing is adjusted so that the ratio L1/t1 of the length L1 of the coining surface in the plate thickness direction and the plate thickness t1 of the cut end portion of the processed product is 0.38 or less. The cut end of the processed product has a sag, a sheared surface, a fractured surface and a coined surface in the plate thickness direction of the cut end of the processed product from the upper surface side to the lower surface side. The length W3 of the fractured surface between the sheared surface and the coined surface in the plate thickness direction of the cut end of the processed product is more than 0 mm and 0.5 mm or less.

According to the embodiment of the processed product and the method for manufacturing the same of the present invention, even when a plated steel sheet having a thickness of more than 2.0 mm is used as a material, it is possible to suppress the area where red rust is generated, and burrs remain. can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows an example of the processed goods manufactured by the processed goods manufacturing method by embodiment of this invention. FIG. 2 is an explanatory diagram showing a first mode of a cut edge in region A of FIG. 1; FIG. 2 is an explanatory diagram showing a second mode of the cut end portion in the region A of FIG. 1; FIG. 3 is an explanatory diagram showing a third mode of the cut end portion in the region A of FIG. 1; Figure 3 is a detailed view of the cross-sectional view of the cut end of Figure 2; 7 is a graph showing an example of the relationship between sagging Z and sagging X; It is explanatory drawing which shows the processed goods manufacturing method by embodiment of this invention. FIG. 8 is an explanatory diagram showing a die and a punch used in the cutting step of FIG. 7; FIG. 9 is an explanatory view showing the cut end of the second element body obtained in the cutting step of FIG. 8; FIG. 10 is a detailed view of a cross-sectional view of the cut end of the second element of FIG. 9; FIG. 8 is an explanatory view showing pads and coining blocks used in the coining process of FIG. 7; 1 is a photograph of a cut end of a processed product after a coining process; It is a perspective view which shows an example of a processed product. FIG. 11 is a perspective view showing another example of a processed product; FIG. 11 is a perspective view showing another example of a processed product; FIG. 11 is a perspective view showing another example of a processed product; FIG. 14 is a schematic diagram showing an example of a cutting die for manufacturing the processed product of FIG. 13; FIG. 18 is a schematic diagram showing a state in which the material is punched by the cutting die of FIG. 17; FIG. 11 is a perspective view showing another example of a processed product;

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated with reference to drawings. The present invention is not limited to each embodiment, and can be embodied by modifying the constituent elements without departing from the scope of the invention. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in each embodiment. For example, some components may be deleted from all the components shown in the embodiments. Furthermore, components of different embodiments may be combined as appropriate.

<About processed products>
FIG. 1 is a perspective view showing an example of a processed product 1 manufactured by a processed product manufacturing method according to an embodiment of the present invention. A processed product 1 shown in FIG. 1 is a motor case made of a plated steel sheet having a plated layer on its surface. The motor case shown in FIG. 1 can be formed by subjecting a flat plated steel plate to forming such as drawing.

A processed product 1 according to the present embodiment has a body portion 10, a projecting portion 11 and a flange portion 12, as shown in FIG.

The trunk portion 10 has a hollow cylindrical side wall 101 and a top wall 103 formed to cover one end of the side wall 101 . The top wall 103 may also be referred to by other names such as the bottom wall, depending on the orientation in which the workpiece 1 is used. The body portion 10 of the processed product 1 shown in FIG. 1 has a perfect circular cross-sectional shape (cross-sectional shape of the body portion 10) in the XY plane, but the present invention is not limited to such an example. The cross-sectional shape of the trunk portion 10 on the XY plane may be other shapes such as an ellipse and a polygon.

The projecting portion 11 is a projecting body projecting outward from the top wall 103 in the central axis direction (Z direction) of the body portion 10 . Note that the protrusion 11 does not necessarily have to be formed, and the top wall 103 may be flat.

The flange portion 12 is a plate portion extending from the end portion of the body portion 10 (that is, the other end of the side wall 101) to the outside of the body portion 10 in the radial direction (X, Y directions). The shape of the flange portion 12 is arbitrary. The flange portion 12 according to the present embodiment extends in the radial direction of the trunk portion 10 over the entire circumference of the trunk portion 10 . A plurality of screw holes 121 are provided in the flange portion 12 so as to be spaced apart from each other in the circumferential direction of the body portion 10 . A screw 123 is inserted through the screw hole 121 . The processed product 1 can be fixed to an attachment target such as a vehicle body by fastening the screw 123 to the attachment target such as a vehicle body.

The flange portion 12 according to the present embodiment is obtained by cutting a flange portion base body (flange portion base body 20 in FIG. 7) having an outer diameter larger than the outer diameter of the flange portion 12 finally formed in the workpiece 1. Formed by processing. That is, the processed product 1 according to the present embodiment has the cut end portion 13 on the outer periphery of the flange portion 12 .

Cutting processes include processes such as cutting, punching and drilling. Cutting is a process of cutting an object to be cut along a predetermined straight line or curve. Stamping is the process of punching out a product from an object to be cut. Drilling is a process of punching a non-product portion from a cutting object to obtain a product having openings. The flange portion 12 shown in FIG. 1 can be obtained by stamping from a flange portion blank.

As the plated steel sheet, plated steel sheets having various plating layers can be used. Various steel sheets can be used as the plated steel sheet, but it is preferable to use a Zn-based plated steel sheet. Zn-based plating includes Zn plating, Zn--Al-based alloy plating, Zn--Al--Mg-based alloy plating and Zn--Al--Mg--Si-based alloy plating. Here, the alloy plating preferably contains Zn in an amount of 80% by mass or more, more preferably 90% by mass or more, based on the total number of moles of the plating.

The base steel sheet of the plated steel sheet is arbitrary, but may be, for example, ultra-low carbon steel.

The lower limit of the coating weight on the plated steel sheet is preferably 30 g/m ² , more preferably 45 g/m ² . In addition, the upper limit of the coating weight on the plated steel sheet is preferably 450 g/m ² , more preferably 190 g/m ² . In particular, by setting the coating weight to 45 g/m ² or more, the plated metal can easily wrap around the sheared surface of the cut end 13 (the sheared surface 13d in FIG. 2), so that the corrosion resistance after cutting can be improved.

The thickness of the plated steel sheet (the thickness of the base steel sheet + the thickness of the plating layer) is arbitrary, but may be 2.0 mm or less, or may be greater than 2.0 mm. The plate thickness of the plated steel sheet can be, for example, 0.8 mm or more and 6.0 mm or less, more preferably 2.0 mm or more and 4.5 mm or less.

<Regarding the cut edge of the processed product>
Next, the cut end portion 13 of the workpiece 1 will be described with reference to FIGS. 2 to 6. FIG. 2 to 4 are explanatory diagrams showing first to third modes of the cut end portion 13 in the area A of FIG. 2 to 4 are cross-sectional views of the cut edge 13 in the ZX plane of FIG. 1, and the right sides of FIGS. It is a front view. FIG. 5 is a cross-sectional detail view of the cut end 13 of FIG. FIG. 6 is a graph showing an example of the relationship between sagging Z and sagging X. In FIG. 2 to 5, the plate thickness direction T of the cut end portion 13 is assumed to be the same direction as the central axis direction (Z direction) of the processed product 1 shown in FIG. 2 to 4, illustration of the plated layer 13h shown in FIG. 5 is omitted.

As particularly shown in FIG. 2, the cut edge 13 has a sag 13c, a sheared surface 13d, a fractured surface 13e, and a coining surface in the plate thickness direction T of the cut edge 13 from the upper surface 13a side toward the lower surface 13b side. 13f in order.

The upper surface 13a is the surface (pressed surface) into which the cutting edge of the cutting die (the die 4 in FIG. 8) is pushed when cutting the flange portion base. The lower surface 13b is the surface from which the cutting edge of the cutting die comes out when cutting the flange portion base body.

In the sag 13c, when the cutting edge of the cutting die is pushed into the flange element body, a tensile force acts on the surface of the flange element element 20 (plated steel sheet), and the surface of the flange element element is deformed. part. The sag 13c typically appears on the cut edge 13 as a smooth curved surface.

In this specification, the dimension of the sagging 13c in the thickness direction T of the cut end 13 is called "sagging Z", and the dimension of the sagging 13c in the planar direction perpendicular to the thickness direction T is called "sagging X". In particular, "sagging Z" at the cut end 13 of the processed product 1 may be called "sagging Z2", and "sagging X" at the cut end 13 of the processed product 1 may be called "sagging X2". On the other hand, "sagging Z" at the cut end portion 13 of the second element 3, which will be described later, is called "sagging Z1", and "sagging X" at the cut end 13 of the second element 3 is called "sagging X1". sometimes called

The sheared surface 13d is a surface obtained by shearing the flange portion blank by the cutting edge of the cutting die. The sheared surface 13 d is adjacent to the sag 13 c in the plate thickness direction T of the cut edge 13 . The sheared surface 13d typically appears at the cut edge 13 as a smooth surface. After the cutting die comes into contact with the workpiece, a compressive (pressurizing) force is applied to bite into the workpiece, and the sheared surface 13d is caused by rubbing against the side surface of the cutting die, so the sheared surface 13d may exhibit metallic luster. be. The sheared surface 13d may have fine streak-like sliding scratches in the plate thickness direction T. As shown in FIG.

The fractured surface 13e is a fractured surface formed by joining together cracks generated in the flange portion base body from the cutting edge of the cutting die. The fractured surface 13 e is adjacent to the sheared surface 13 d in the plate thickness direction T of the flange portion 12 . The fracture surface 13e typically appears at the cut edge 13 as a matte, rough surface. The fracture surface may have an inclination according to the gap (clearance) of the cutting die.

The coining surface 13f is a surface obtained by pressing or compressing the corner portion 13i (see FIG. 7) of the cut end portion 13 on the lower surface 13b side by a coining process described later. The coining surface 13f of the present embodiment is a C surface (C chamfered surface). However, the coining surface 13f may be another pressing or compressing surface such as an R surface (R-chamfered surface). The coining surface 13f typically appears on the cut edge 13 as a smooth surface in which the unevenness of the fractured surface is flattened.

As a method of specifying the sagging 13c, the sheared surface 13d, the fractured surface 13e, and the coined surface 13f (method of measuring the length of each) in the cut end 13, for example, a microscope or a controller is used from the appearance based on the above characteristics. There is a method of observing and measuring the shape profile of the cut end portion 13 with a laser or the like.

As described above, the fractured surface 13e is a new rough surface formed as a result of coalescence of cracks generated in the base body of the flange portion. At the fracture surface 13e, the metal components of the steel base are exposed. For this reason, the broken surface 13 e tends to develop red rust earlier than the other surfaces of the cut end portion 13 . On the other hand, the coining surface 13f is a pressed or compressed smooth surface, and red rust is less likely to occur than the rough fractured surface 13e. This is probably because the smoothness of the surface roughness makes it difficult for water to stay on the coining surface 13f. Similarly, since the sheared surface 13d is also a smooth surface, red rust is less likely to occur than the fractured surface 13e.

The present inventors conducted experiments in which the conditions of cutting and coining were changed in various ranges, and investigated the occurrence of red rust in various cut ends 13 . As a result, (1) the length W3 of the fractured surface 13e between the sheared surface 13d and the coined surface 13f in the plate thickness direction T of the cut end 13 (hereinafter also referred to as "fractured surface length W3") exceeds 0 mm and By being 0.5 mm or less, even when a plated steel sheet having a thickness of more than 2.0 mm is used as a material, the area where red rust occurs can be suppressed, and even if red rust occurs on the fracture surface 13e, It turned out that it can be judged that it does not become a problem practically because it is inconspicuous. The fracture surface length W3 is preferably 0.3 mm or less, more preferably 0.2 mm or less. Moreover, after the cutting process, a burr is formed following the fracture surface 13e. By forming the coining surface 13f, burrs can be crushed and the remaining burrs can be suppressed.

Here, in the coining process for forming the coining surface 13f, a pressing or compressing force acts on the cut end portion 13 from the lower surface 13b side of the cut end portion 13 toward the upper surface 13a side. The sagging 13c, the sheared surface 13d and the fractured surface 13e may be pushed up. Depending on the amount of coining, the sagging 13c of the cut end 13 may take the form shown in FIG. 3 or 4 instead of the form shown in FIG.

FIG. 3 shows a mode in which the boundary position 13g between the droop 13c and the sheared surface 13d is pushed up to the same height position as the upper surface 13a by coining. FIG. 4 shows a mode in which the boundary position 13g between the droop 13c and the sheared surface 13d is pushed up to a position higher than the upper surface 13a by coining. 3 and 4, following the smooth upper surface 13a of the cut edge 13, a deformed surface corresponding to the sagging 13c remains. The deformed surface may bulge upward from the smooth upper surface 13a. In this specification, such a deformed surface is also treated as the sagging 13c. In particular, the sagging 13c as shown in FIG. 4 is sometimes called an upwardly convex sagging 13c.

As shown in FIG. 4, in the case of an upwardly convex sagging 13c, that is, when the boundary position 13g between the sagging 13c and the sheared surface 13d is pushed up to a position higher than the upper surface 13a, if the amount of push-up at the boundary position 13g is too large, Excessive deformation of the cut end 13 may cause problems such as loss of stability of the screw 123 (see FIG. 1).

The present inventors conducted experiments in which the conditions for cutting and coining were changed in various ranges as described above, and as a result, (2) the length L1 of the coining surface 13f in the plate thickness direction T and the cut edge Since the ratio L1/W2 of the distance W2 between the lower surface 13b of the portion 13 and the upper end of the fractured surface 13e is 0.95 or less, it is possible to suppress the occurrence of defects due to excessive deformation of the cut end portion 13. I found out. The ratio L1/W2 is preferably 0.85 or less. As a result, excessive deformation of the cut end portion 13 can be suppressed more reliably.

Further, the inventors of the present invention conducted experiments from a different point of view and found that (3) the ratio L1/t1 between the length L1 of the coining surface 13f in the plate thickness direction T and the plate thickness t1 of the cut end portion was 0.5. It has also been found that the occurrence of defects due to excessive deformation of the cut end portion 13 can be suppressed by setting it to 38 or less. The ratio L1/t1 is preferably 0.32 or less. As a result, excessive deformation of the cut end portion 13 can be suppressed more reliably.

Either one of the numerical ranges of the ratio L1/W2 and the ratio L1/t1 may be satisfied, or both of them may be satisfied. Both the ratio L1/W2 and the ratio L1/t1 can be understood as indices corresponding to the amount of coining when manufacturing the processed product 1 .

The value obtained by adding the "length L1 of the coining surface 13f" to the "length W3 of the fractured surface 13e between the sheared surface 13d of the cut edge 13 and the coining surface 13f in the plate thickness direction T" is the "cut edge The distance W2 between the lower surface 13b of the portion 13 and the upper end of the fractured surface 13e (W2=L1+W3). The plate thickness t1 of the cut end portion 13 of the processed product 1 is equal to the plate thickness of the flange portion 12 of the processed product 1 . The plate thickness t1 of the cut edge 13 may be the distance between the upper surface 13a and the lower surface 13b of the cut edge 13 at a position not affected by the droop 13c and the coining surface 13f.

(4) The ratio Z2/t1 between the length Z2 of the sag 13c in the plate thickness direction T toward the lower surface 13b of the cut end 13 with respect to the upper surface 13a of the cut end 13 and the plate thickness t1 of the cut end 13 is preferably -0.1 or more and 0.25 or less. When the ratio Z2/t1 is −0.1 or more, it is possible to prevent the upwardly convex sag 13c from excessively protruding from the upper surface 13a, thereby suppressing the possibility of causing problems due to excessive deformation of the cut end portion 13. be able to. When the ratio Z2/t1 is 0.25 or less, it is possible to prevent the droop X (the dimension of the droop 13c in the planar direction perpendicular to the plate thickness direction T) from becoming too large. The ratio Z2/t1 is more preferably 0 or more and 0.1 or less. Thereby, the shape of the cut end portion 13 can be made in a more preferable state. The ratio Z2/t1 may be -0.10 or more and less than 0, or 0.1 or more and 0.25 or less.

It is known that sagging Z and sagging X have a correlation with each other. FIG. 6 shows an example of the relationship between the sagging Z and the sagging X of the cut end when punching is performed in one step. In FIG. 6, the blade edge of the cutting die to be pushed into the flange element body is given a radius of curvature of 0.01 to 0.30 relative to the plate thickness of the flange element body, and the clearance of the cutting die is set to 0 of the plate thickness. It shows the relationship between the droop Z and droop X at the cut end of the product when punching is performed by setting the ratio to 0.01 to 0.20. As shown in FIG. 6, when punching is performed in one step, the sag X appearing in the plane direction is approximately three to four times as large as the sag Z in the plate thickness direction. Although this correlation is pre-coining, it also affects post-coining.

When measuring the length Z2 of the sag 13c, the height position of the upper surface 13a of the cut end 13 is defined as a reference position (0 point), and the length from the upper surface 13a to the position below is defined as a positive length. The length to a position above 13a is defined as a negative length. The reference position is the height position of the upper surface 13a of the cut end 13 at a position not affected by the droop 13c and the coining surface 13f (a position sufficiently distant from the outer edge of the cut end 13).

For example, height position measurement points can be scanned on the surface of the cut edge 13 from a position unaffected by the droop 13c and the coining surface 13f toward the outer edge of the cut edge 13 . When the boundary position 13g is lower than the upper surface 13a as in the first mode shown in FIG. 2, the height position of the surface of the cut end 13 gradually decreases toward the boundary position 13g, exceeding the boundary position 13g. In this case, the height positions of the surface of the cut edge 13 take discontinuous values. When the boundary position 13g is at the same height position as the upper surface 13a as in the second mode shown in FIG. When exceeding 13 g, the height position of the surface of the cut edge 13 takes a discontinuous value. When the boundary position 13g is higher than the upper surface 13a as in the third mode shown in FIG. 4, the height position of the surface of the cut end 13 gradually rises toward the boundary position 13g and exceeds the boundary position 13g. In this case, the height positions of the surface of the cut edge 13 take discontinuous values. The length Z2 of the sag 13c can be the length in the plate thickness direction T between the height position immediately before the height position of the surface of the cut edge 13 takes a discontinuous value and the reference position. The height position immediately before the height position of the surface of the cut edge 13 takes a discontinuous value can be the height position of the boundary position 13g. As a method for measuring the length Z2 of the droop 13c, for example, there is a method of observing and measuring the shape profile of the cut end portion 13 using a contourer or the like.

As shown in FIG. 5, in the processed product according to the present embodiment, the cut end portion 13 is formed such that the plated layer 13h extends from the upper surface 13a of the cut end portion 13 to the sheared surface 13d. The plated layer 13h wraps around the sheared surface 13d by being stretched by the cutting die when the edge of the cutting die bites into the flange portion base body. At least a portion of the sheared surface 13d is covered with the plated layer 13h by the wrapping of the plated layer 13h. In the portion of the sheared surface 13d covered with the plating layer 13h, the occurrence of red rust can be further suppressed.

Further, in the processed product according to the present embodiment, the cut end portion 13 is formed so that the plating layer 13h extends from the lower surface 13b of the cut end portion 13 to the coining surface 13f. When the coining process is performed, the plated layer 13h on the lower surface 13b is pressed or compressed together with the portion forming the coining surface 13f, and wraps around the coining surface 13f. At least a portion of the coining surface 13f is covered with the plating layer 13h by the winding of the plating layer 13h. In the portion of the coining surface 13f covered with the plating layer 13h, the occurrence of red rust can be further suppressed.

At this time, (5) the distance W2 between the lower surface 13b of the cut end portion 13 and the upper end of the fracture surface 13e in the plate thickness direction T and the distance L2 between the upper end of the plating layer 13h from the lower surface 13b in the plate thickness direction is preferably 1.4 mm or less. The difference W2-L2 corresponds to the length in the plate thickness direction T of the region not covered with the plating layer 13h. When the difference W2-L2 is 1.4 mm or less, the occurrence of red rust can be suppressed more reliably. However, since the sheared surface 13d and the coined surface 13f are smooth surfaces, even the portions not covered with the plating layer 13h can suppress the occurrence of red rust compared to the rough fractured surface 13e.

Further, (6) the distance W2 between the lower surface 13b of the cut end portion 13 and the upper end of the fractured surface 13e is preferably 1.6 mm or less. When the distance W2 is 1.6 mm or less, the occurrence of red rust can be suppressed more reliably.

<Regarding processed product manufacturing method>
Next, FIG. 7 is an explanatory diagram showing a method for manufacturing a processed product according to an embodiment of the present invention. As shown in FIG. 7, the method for manufacturing a processed product according to the present embodiment includes a preparation process, a cutting process, and a coining process.

The preparation step is a step of preparing the first element body 2 . The first element body 2 can be obtained by subjecting a plate-like plated steel sheet to a forming process such as drawing. That is, the first element body 2 is made of a plated steel plate, like the processed product 1 . The first element 2 has a flange portion element 20 wider than the flange portion 12 shown in FIG. The outer shape of the flange portion base body 20 when viewed in plan may be circular or non-circular. The first element 2 can have the same shape as the workpiece 1 except for the flange element element 20 . Note that the preparatory step does not have to involve forming the plated steel sheet. You may obtain a body that has been processed by a third party in some way. The flange portion base body 20 of the present embodiment constitutes a plate-like portion to be cut including a portion that will become the cut end portion 13 .

The cutting step is a step of cutting the flange portion element body 20 (the portion to be cut) of the first element element 2 once to obtain the second element element 3 . The second element 3 is an intermediate member for manufacturing the processed product 1 , and the processed product 1 can be obtained by further processing the second element 3 . One cutting process is not cutting the flange portion base body 20 through a plurality of steps such as half cutting and finish cutting, but cutting the flange portion in one step using a die 4 and a punch 5 described later. This is a process of cutting off the removed portion 20a from the element body 20. FIG. The flange element 20 of the second element 3 has a cut end 13 . The cut end portion 13 of the second element 3 has a corner portion 13i on the lower surface 13b side. The corner 13i may have burrs.

The coining step is a step of applying coining to the cut end portion 13 of the second element body 3 obtained in the cutting step to obtain a processed product. As will be described later with reference to the drawings, the coining process of the present embodiment is performed by pressing the corner 13i of the cut end 13 of the second element body 3 against the pad 7 to form the coining surface 13f on the corner 13i. It is a process to form. The coining surface 13f is a surface where the corner portion 13i is crushed. In the processed product manufacturing method according to the embodiment, the processed product 1 having the flange portion 12 is obtained by forming the coining surface 13 f on the corner portion 13 i of the flange portion base body 20 of the second base body 3 . The screw holes 121 of the processed product 1 shown in FIG. 1 may be formed in the flange part base body 20 at the stage of the first base body 2 or the second base body 3, or may be formed in the flange part 12 after the coining process. may

<Mold used for cutting process>
Next, FIG. 8 is an explanatory diagram showing the die 4 and punch 5 used in the cutting step of FIG. The upper side of FIG. 8 shows the state immediately before cutting, and the lower side of FIG. 8 shows the state immediately after cutting.

Regarding the molds used to obtain the processed product 1, the mold on the pushing side is called a die 4 and the mold on the pushed side is called a punch 5 for convenience. The mold on the pushing side may be positioned above or below the blank. Also in the case of horizontal movement, the mold on the pushing side is called a die 4 and the mold on the pushed side is called a punch 5 . For example, the workpiece 1 shown in FIG. 2 is cut by using the upper mold as the mold on the pushing side. When the lower mold is the mold on the pushing side, that is, when the lower mold is the die 4, the cut edge 13 of the workpiece 1 is opposite to that shown in FIG. It is located at the lowest position, and above it, a sheared surface 13d, a fractured surface 13e and a coining surface 13f are formed. When it is unclear which of the upper and lower (or left and right) molds will be the die 4 or the punch 5, after actually cutting, the cut end portion 13 is observed and the side where the sagging 13c is located The die for pressing the surface of the plate may be called a die 4, and the die for pressing the opposite surface may be called a punch 5. In any case, as described above, the upper surface 13a of the cut end portion 13 is the surface of the side into which the cutting edge of the die 4 is pushed during cutting of the flange portion base body 20, that is, the side of the side where the sagging 13c is located. Defined as surface. The lower surface 13b of the cut end portion 13 is defined as the surface from which the cutting edge of the die 4 exits when the flange portion base body 20 is cut.

As shown in FIG. 8, in the cutting step of the method for manufacturing a processed product according to the present embodiment, a die 4 and a punch 5 are used to cut the flange portion base body 20 of the first base body 2 . FIG. 8 shows, as one aspect of the cutting process, the die 4 punching out the removed portion 20a from the flange portion element 20 of the first element 2 sandwiched between the punch 5 and the plate retainer 6. As shown in FIG.

It is preferable that the cutting edge of the die 4 has an R shape with a predetermined radius of curvature R as shown in FIG. In general, if the radius of curvature R of the cutting edge of the die 4 is increased, the ratio of the fractured surface to the entire cut surface can be reduced. It is preferable that the cutting edge of the punch 5 be square without roundness, as shown in FIG. At this time, the cutting edge of the punch 5 may have a radius of curvature of less than 0.25 mm, less than 0.15 mm, less than 0.10 mm, or less than 0.05 mm. Alternatively, the radius of curvature of the cutting edge of the punch 5 may be less than 0.1 times the plate thickness t1 of the flange portion base body 20 of the first base body 2, and may be less than 0.06 times or 0.04 times as needed. It may be less than times or less than 0.02 times.

A predetermined clearance C _4-5 [mm] is provided between the die 4 and the punch 5 . The clearance _C4-5 in the cutting step of the method for manufacturing a processed product according to this embodiment is a plus clearance. C _4-5 is represented by the distance between the side surface 4 a of the die 4 and the side surface 5 a of the punch 5 . As shown in FIG. 8, the clearance when the die 4 and the punch 5 are separated from each other in the direction orthogonal to the pushing direction of the die 4 is called plus clearance. On the other hand, the clearance when the die 4 and the punch 5 partially overlap in the direction perpendicular to the pushing direction of the die 4 is called a negative clearance. Generally, when the positive clearance value is decreased, the ratio of the fractured surface to the entire cut surface can be decreased.

<Cut End of Second Element>
Next, the cut end portion 13 of the second element body 3 will be described with reference to FIGS. 9 and 10. FIG. FIG. 9 is an explanatory diagram showing the cut end portion 13 of the second element body 3 obtained in the cutting step of FIG. The left side of FIG. 9 is a cross-sectional view of the cut end portion 13 of the second element 3 in the ZX plane of FIG. 1, and the right side of FIG. 9 is the second element 3 when viewed along the Y direction of FIG. is a front view of the cut end 13 of . FIG. 10 is a detailed cross-sectional view of the cut end 13 of the second element body 3 of FIG.

As shown in FIGS. 9 and 10, the cut end portion 13 of the second element 3 cut by the die 4 and the punch 5 extends from the upper surface 13a side toward the lower surface 13b side in the plate thickness direction T of the cut end portion 13. It has sagging 13c, sheared surface 13d, fractured surface 13e and burr 13k.

The sagging 13c, the sheared surface 13d and the fractured surface 13e of the second element 3 are the same as the sag 13c, the sheared surface 13d and the fractured surface 13e of the cut end portion 13 of the processed product 1 described with reference to FIG.

However, the cut end portion 13 of the second element 3 is not subjected to coining processing, and compared with the sagging 13c, the sheared surface 13d, and the fractured surface 13e of the processed product 1, the sagging 13c, the sheared surface 13e of the second element 3 are The cross section 13d and the fractured surface 13e are in a state where they are wholly lowered toward the lower surface 13b. A boundary position 13g between the sag 13c and the sheared surface 13d of the second element body 3 is located below the upper surface 13a, and is at the same height as the upper surface 13a as shown in FIG. Also, it does not reach a position higher than the upper surface 13a. The length W1 of the fractured surface 13e of the second element body 3 in the plate thickness direction T is longer than the length W3 of the fractured surface 13e between the sheared surface 13d and the coining surface 13f of the workpiece 1 (see FIG. 2, etc.). long. This is because the fracture surface 13e of the second element body 3 is crushed by the subsequent coining process to form the coining surface 13f. Further, the length W1 of the fractured surface 13e of the second element body 3 in the plate thickness direction T is the distance W2 between the lower surface 13b of the cut end portion 13 of the processed product 1 and the upper end of the fractured surface 13e (see FIG. 2, etc.). ). This is because the upper end of the fracture surface 13e of the second element body 3 is pushed up by the subsequent coining process.

The burr 13k is a portion where the flange portion base body 20 is stretched or torn off when the fracture surface 13e is formed. The burr 13k is provided adjacent to the fracture surface 13e in the plate thickness direction T of the cut end portion 13. As shown in FIG.

The shape and size of these sag 13c, sheared surface 13d, fracture surface 13e and burr 13k are determined by clearance C _4-5 between die 4 and punch 5, cutting edge shape of die 4 and punch 5, contour of second element 3 It depends on the shape. Depending on the cutting process, the burr 13k may not occur. That is, the cut end portion 13 of the second element body 3 may not have the burr 13k. A corner portion 13i on the lower surface 13b side of the cut end portion 13 of the second element 3 may be formed by the burr 13k or the lower end of the fractured surface 13e.

In the cutting step, (6′) the flange portion element body 20 (to be cut) of the first element body 2 is cut so that the length W1 of the fracture surface 13e of the second element body 3 in the plate thickness direction T is 1.5 mm or less. part) is preferably cut. The length W1 of the fracture surface 13e of the second element body 3 is set to 1.5 mm or less, and the length W3 of the fracture surface 13e after coining is more than 0 mm and 0.5 mm or less. Excessive amounts can be avoided.

As described above, the larger the radius of curvature R of the die 4, the smaller the proportion of the fracture surface 13e in the entire cut surface. Also, the smaller the clearance _C4-5 between the die 4 and the punch 5 within the plus clearance range, the smaller the ratio of the fractured surface 13e to the entire cut surface. Therefore, by adjusting the curvature radius of the die 4 and the clearance between the die 4 and the punch 5 according to the plate thickness t, the length W1 of the fracture surface 13e of the second element body 3 is set to 1.5 mm or less. can be done.

Further, as particularly shown in FIG. 10, in the cutting step of the present embodiment, the cut end portion 13 is formed so that the plated layer 13h extends from the upper surface 13a to the sheared surface 13d. The plated layer 13h wraps around the sheared surface 13d by being stretched by the die 4 when the cutting edge of the die 4 bites into the plated steel sheet. At least a portion of the sheared surface 13d is covered with the plated layer 13h by the wrap of the plated layer 13h, and the occurrence of red rust in the portion covered with the plated layer 13h can be suppressed. Further, when the plating layer 13h is a Zn-based plating layer, the sacrificial anti-corrosion action of the Zn-based plating layer can suppress the occurrence of red rust in the vicinity of the portion covered with the plating layer 13h.

The wraparound of the plating layer 13h becomes more pronounced as the radius of curvature R applied to the tip of the cutting edge of the die 4 pushed into the flange portion base body 20 increases. If the radius of curvature R given to the tip of the cutting edge is small, this prevents the material directly under the die 4 from flowing from the tip of the cutting edge of the die 4 to the side surface. For this reason, the shear force element becomes dominant, cracks are generated early in the material from the cutting edge of the die 4, and a wider fracture surface 13e is generated. On the other hand, if the radius of curvature R imparted to the tip of the cutting edge is large, the material immediately below the die 4 is encouraged to flow from the tip of the cutting edge of the die 4 to the side surface. As a result, the element of the shearing force is weakened, the generation of cracks from the cutting edge of the die 4 is delayed, and the sheared surface 13d is lengthened. As the material directly under the die 4 flows from the tip of the cutting edge of the die 4 to the side surface, the plating layer 13h is stretched thin and wraps around the sheared surface 13d.

As described above, the radius of curvature R given to the tip of the cutting edge of the die 4 is determined so that the length W1 of the fractured surface 13e of the second element 3 is 1.5 mm or less, and the plate thickness t and the distance between the die 4 and the punch 5 are 1.5 mm or less. Although it may be adjusted according to the clearance C _4-5 , from the viewpoint of ensuring that the plating layer 13h is wrapped around the sheared surface 13d, it is 0.08 times the plate thickness of the flange portion base body 20 before cutting. It is preferable to set it to 0.45 times or less.

<Molds used in the coining process>
Next, FIG. 11 is an explanatory diagram showing the pad 7 and coining block 8 used in the coining process of FIG. As shown in FIG. 11, in the coining process of the present embodiment, the cut end portion 13 of the second element body 3 is sandwiched between the pad 7 and the coining block 8 . The pad 7 has a vertical wall surface 70 , a bottom wall surface 71 and a pressing surface 72 .

The vertical wall surface 70 is arranged so as to face and be substantially parallel to the sheared surface 13d of the second element body 3 when the cut end portion 13 of the second element body 3 is sandwiched between the pad 7 and the coining block 8. be done. The vertical wall surface 70 is arranged so as to be parallel to the advancing/retreating direction of the coining block 8 (the Z direction in FIG. 11).

The bottom wall surface 71 is arranged to face the coining block 8 in the plate thickness direction T of the cut end portion 13 with the second element body 3 interposed therebetween. The bottom wall surface 71 extends in a direction orthogonal to the vertical wall surface 70 below the vertical wall surface 70 (that is, on the side opposite to the coining block 8).

The pressing surface 72 is a surface that connects the vertical wall surface 70 and the bottom wall surface 71 . The pressing surface 72 is provided for forming a coining surface (coining surface 13f in FIGS. 2 to 4) on the second element body 3, and is formed in a shape corresponding to the shape of the coining surface. For example, as shown in FIGS. 2 to 4, when the coining surface 13f is a planar chamfered surface (hereinafter referred to as “C surface”), the pressing surface 72 is formed on the vertical wall surface 70 and the bottom wall surface 71. A plane that is inclined with respect to the plane may be used. Further, for example, when the coining surface 13f is formed into a curved chamfered surface (hereinafter referred to as "R surface"), the pressing surface 72 may be formed into a curved surface.

In the coining process, as shown in FIG. 11, the cut end portion 13 of the second element 3 is opposed to the vertical wall surface 70 of the pad 7, and the coining block 8 and the bottom wall surface 71 of the pad 7 are used to form the second The element body 3 is sandwiched in the plate thickness direction T. Then, the coining block 8 is pushed toward the bottom wall surface 71 to push down the second element body 3 until the lower surface 13 b of the second element body 3 contacts the bottom wall surface 71 . Here, before the lower surface 13b of the second element body 3 contacts the bottom wall surface 71, the corner portion 13i or the burr 13k is pressed against the pressing surface 72. As shown in FIG. After the corner portion 13 i or the burr 13 k is pressed against the pressing surface 72 , the coining block 8 is pushed further so that the lower surface 13 b of the second element body 3 contacts the bottom wall surface 71 . In this process, the corner portion 13i or the burr 13k and the fractured surface 13e are crushed by the pressing surface 72 to form the coining surface 13f shown in FIGS. The cut end 13 of the processed product 1 after the coining process is in a state as shown in the photograph of FIG. 12, for example.

The coining surface 13f is a smooth surface to which the surface of the pressing surface 72 is transferred, and red rust is less likely to occur than the rough fractured surface 13e. This is probably because the smoothness of the surface roughness makes it difficult for water to stay on the coining surface 13f. In addition, it is considered that the fact that the plating layer 13h on the side of the lower surface 13b of the cut end 13 is thinly extended to the coining surface 13f is also a factor that makes it difficult for red rust to occur. By forming the coining surface 13f on the corner 13i on the side of the lower surface 13b, the fracture surface length W3 (see FIGS. 2 to 4) in the plate thickness direction T at the cut edge 13 after coining is the same as before coining. is shorter than the fracture surface length W1 (see FIG. 9) in the plate thickness direction T at the cut end portion 13 of the second element body 3 . That is, the coining process can narrow the area of the fractured surface 13e, which is a new rough surface, and suppress the area where red rust occurs. Moreover, the coining process can crush the burrs 13k, and the remaining burrs 13k on the processed product 1 can be suppressed more reliably.

The present inventors conducted experiments in which the conditions of cutting and coining were changed in various ranges, and investigated the occurrence of red rust in various cut ends 13 . As a result, in the (1′) coining process, the length W3 of the fractured surface 13e between the sheared surface 13d and the coined surface 13f in the plate thickness direction T of the cut end 13 of the workpiece 1 (fractured surface length W3) By adjusting the amount of processing and performing coining so that the is more than 0 mm and 0.5 mm or less, even when a plated steel sheet with a thickness of more than 2.0 mm is used as a material, the area where red rust occurs is suppressed. I found that it can be done. More specifically, it was found that if the length W3 of the fractured surface 13e is 0.5 mm or less, even if red rust occurs on the fractured surface 13e, it will not be conspicuous and will not pose a practical problem. The amount of processing is the amount of pressing of the corner portion 13 i against the pressing surface 72 . Further, by adjusting conditions such as the position and angle of the pressing surface 72, the amount of processing can be adjusted.

In addition, the present inventors conducted experiments in which the conditions for cutting and coining were changed in various ranges as described above, and as a result, (2') in the coining step, in the plate thickness direction T of the processed product 1 The ratio L1/W1 of the length L1 (see FIGS. 2 to 4) of the coining surface 13f and the length W1 (see FIG. 9) of the fracture surface 13e of the second element body 3 in the plate thickness direction T is 1.0 or less. It was found that by performing the coining process by adjusting the amount of processing so as to achieve the following, it is possible to suppress the occurrence of defects due to excessive deformation of the cut end portion 13 . The ratio L1/W1 is preferably 0.9 or less. As a result, excessive deformation of the cut end portion 13 can be suppressed more reliably. The length L1 of the coining surface 13f can be estimated based on how much coining is performed. The length W1 of the fracture surface 13e of the second element body 3 is known during the coining process.

In addition, the present inventors examined the experiment from a different point of view, and as a result, in the (3′) coining step, the length L1 of the coining surface 13f in the plate thickness direction T of the processed product 1 and the cut end portion of the processed product 1 By performing coining by adjusting the amount of processing so that the ratio L1/t1 to the plate thickness t1 (see FIGS. 2 to 4) of 13 is 0.38 or less, excessive deformation of the cut end 13 It was found that the occurrence of defects can be suppressed. It is preferable that the ratio L1/t1 is 0.32 or less. As a result, excessive deformation of the cut end portion 13 can be suppressed more reliably. The length L1 of the coining surface 13f can be estimated based on how much coining is performed. The plate thickness t1 of the cut end portion 13 of the processed product 1 may be the plate thickness t1 of the cut end portion 13 of the second element body 3 .

Either one of the numerical ranges of the ratio L1/W1 and the ratio L1/t1 may be satisfied, or both of them may be satisfied.

Further, in the coining step, (4′) the length Z2 of the droop 13c in the thickness direction T toward the lower surface 13b of the cut end 13 of the workpiece 1 with the upper surface 13a of the cut edge 13 of the workpiece 1 as a reference and the machining It is preferable to perform coining by adjusting the amount of processing so that the ratio Z2/t1 to the plate thickness t1 of the cut end portion 13 of the product 1 is −0.1 or more and 0.25 or less. The length Z2 of the droop 13c can be estimated based on how much coining is performed. The plate thickness t1 of the cut end portion 13 may be the plate thickness t1 of the cut end portion 13 of the second element body 3 . When the ratio Z2/t1 is −0.1 or more, it is possible to prevent the upwardly convex sag 13c from excessively protruding from the upper surface 13a, thereby suppressing the possibility of causing problems due to excessive deformation of the cut end portion 13. be able to. When the ratio Z2/t1 is 0.25 or less, it is possible to prevent the droop X (the dimension of the droop 13c in the planar direction perpendicular to the plate thickness direction T) from becoming too large. The ratio Z2/t1 is more preferably 0 or more and 0.1 or less. Thereby, the shape of the cut end portion 13 can be made in a more preferable state. The ratio Z2/t1 may be -0.10 or more and less than 0, or 0.1 or more and 0.25 or less.

Further, in the coining process as described above, the plating layer 13h wraps around the coining surface 13f from the lower surface 13b of the cut end portion 13 . In the coining step, (5′) the length W1 of the fracture surface 13e of the second element 3 in the plate thickness direction T and the length L2 ( 5) is preferably 1.25 mm or less, and coining is preferably performed by adjusting the processing amount so that the difference W1-L2 is 1.0 mm or less. It is more preferable to do so. The length W1 of the fracture surface 13e of the second element body 3 is known during the coining process. The wraparound length L2 of the plated layer 13h from the lower surface 13b of the cut end portion 13 can be estimated based on how much coining is performed. The difference W1-L2 predicts how much of the region will be left uncovered by the plating layer 13h. When the difference W1-L2 is 1.25 mm or less, the occurrence of red rust can be more reliably suppressed, and when the difference W1-L2 is 1.0 mm or less, the occurrence of red rust can be suppressed even more reliably. .

<Processed product example>
In the above embodiment, the case where the processed product 1 is a motor case as shown in FIG. 1 has been described. , and may be any article having a cut edge 13 .

The workpiece 1 may be, for example, an annular flat washer 900 as shown in FIG. Alternatively, the workpiece 1 may be plain washers 910A, 910B, 910C having teeth 911 as shown in FIG. 14, for example. Alternatively, the workpiece 1 may be, for example, a corrugated toric disc spring 920 as shown in FIG. The disk spring 920 of FIG. 15 can be manufactured, for example, by processing the flat washer 900 shown in FIG. 13 into a corrugated shape. Further, the workpiece may be, for example, a disc spring 930 having teeth 931 as shown in FIG.

When the processed product 1 is various kinds of annular plate members as shown in FIGS. By applying the processed product manufacturing method according to the above-described embodiment, at least one of the outer peripheral portion and the inner peripheral portion is: The length W3 of the fracture surface 13e between (hereinafter also referred to as “fracture surface length W3”) is more than 0 mm and 0.5 mm or less, and (2) the length L1 of the coining surface 13f in the plate thickness direction T and The ratio L1/W2 of the distance W2 between the lower surface 13b of the end portion 13 and the upper end of the fracture surface 13e is 0.95 or less, and/or (3) the length of the coining surface 13f in the plate thickness direction T The ratio L1/t1 between L1 and the plate thickness t1 of the cut end can be 0.38 or less.

For example, in order to cover the sheared surfaces of the inner and outer peripheral surfaces of the flat washer 900 shown in FIG. 13 with a plating layer, a cutting die as shown in FIGS. . FIG. 17 is a schematic diagram showing an example of a cutting die for processing the flat washer 900. As shown in FIG. FIG. 18 is a schematic diagram showing a state in which the blank 9 is punched by the cutting die of FIG.

The cutting die shown in FIG. 17 is a die for manufacturing an annular processed product 90 such as a flat washer 900, and includes a hollow cylindrical die (hereinafter referred to as "outer die") 61 and a cylindrical die. It has a shaped die (hereinafter referred to as "inner die") 63 and a hollow cylindrical punch 65 for supporting the disk-shaped blank 9 (see FIG. 18). The outer die 61 and inner die 63 and the punch 65 are provided facing each other. The inner diameter of outer die 61 corresponds to the outer diameter of workpiece 90 and the outer diameter of inner die 63 corresponds to the inner diameter of workpiece 90 . The edge of the inner peripheral surface of the outer die 61 and the edge of the outer peripheral surface of the inner die 63 have an R shape with a radius of curvature. On the other hand, the edges of the inner peripheral surface and the outer peripheral surface of the punch 65 do not have an R shape.

When the base body 9 is finished and cut with such a cutting die, as shown in FIG. The inner die 63 cuts the portion 9 b that is inside the peripheral surface 92 . Thereby, a processed product 90 (flat washer 900) as shown in FIG. 13 is formed.

Furthermore, the workpiece 1 may be, for example, a disk-shaped plate 940 as shown in FIG.

Examples are given below. Samples of the second element 3 and the processed product 1 were produced by the method shown in FIG. As the plated steel plate, a Zn-6%Al-3%Mg (mass ratio) alloy plated steel plate with a plate thickness of 1.1 to 4 mm and a coating amount of 90 g/m ² (one side) or 190 g/m ² (one side) is used. Using. The cutting process uses a round die with an inner diameter of φ85 mm (doughnut-shaped or annular die) and a round punch whose diameter is changed according to the clearance C _4-5 , and the flange of the second element 3 is pressed by a plate holder. The subelement body 20 was held. At this time, the shoulder portion of the die 4 was formed into an R shape having a predetermined radius of curvature.

For each sample, the length W1 of the fractured surface 13e after punching and the lengths W2 and W3 of the fractured surface 13e after coining were measured. These were obtained by measuring the circumference of the end face of the processed product at 30° intervals using a microscope and averaging the measured values of a total of 12 points. In addition, for each sample, regarding the wrapping of the plating layer 13h to the coining surface 13f of the cut end portion 13, the plating layer 13h wrapped around the plate thickness direction T of the cut end portion 13 from the cross section of the flange portion 12 of the processed product. A length L2 was measured. An electron probe microanalyzer (EPMA-WDS) was used to measure the length L2 of the plating layer 13h at the cut edge 13. FIG. It was determined that the plating layer 13h was present in a portion where the detection level of the Zn component was three times or more the background. The objects to be measured are the second element 3 obtained by the cutting process and the processed product 1 obtained by the coining process.

The burrs 13k, which cause dents, electrical shorts, etc., were evaluated. Samples with burrs 13k of less than 0.2 mm in size were evaluated as "good", and samples with burrs 13k of 0.2 mm or more in size or samples with whisker-like burrs were evaluated as "poor".

In addition, sagging Z after coining (Z2 for those with coining and Z1 for those without coining) was also evaluated. Those with Z2/t1 (or Z1/t1) of 0 or more and less than 0.1 are evaluated as "◎", and Z2/t1 (or Z1/t1) of -0.1 or more and 0.25 or less (however, ) were evaluated as "O", and those with Z2/t1 (or Z1/t1) of less than -0.1 or greater than 0.25 were evaluated as "x".

Furthermore, the sample was subjected to an atmospheric exposure test outdoors, and the number of days until conspicuous red rust appeared on the cut edges was observed every 15 days.

Table 1 shows the above results. Table 1 also shows the plated steel sheet used for each sample, the punching conditions, whether or not the corner 13i of the cut edge 13 was subjected to coining, and the dimensions of the coining surface 13f. Here, the curvature radius (plate thickness ratio) of the die 4 is obtained by dividing the roundness imparted to the shoulder portion of the die 4 by the plate thickness. Those not intentionally rounded are described as "<0.01" in this column. When the coining surface 13f is the R surface, the numerical value of the dimension L1 is enclosed in < >.

As shown in Table 1, in Examples 1 to 21, the fracture surface length W3 after coining was 0.5 mm or less. The cut ends showed good corrosion resistance up to 60 days or more until red rust appeared. Further, in Examples 1 to 21, no burr was generated and the dimension of sagging Z was good.

In any of the examples, in the state of the processed product 1, (2) the length L1 of the coining surface 13f in the plate thickness direction T and the distance W2 between the lower surface 13b of the cut end portion 13 and the upper end of the fracture surface 13e The ratio L1/W2 was 0.95 or less, and (3) the ratio L1/t1 between the length L1 of the coining surface 13f in the plate thickness direction T and the plate thickness t1 of the cut end was 0.38 or less. . Further, in any of the examples, (2′) length L1 of coining surface 13f in plate thickness direction T of processed product 1 and length W1 of fracture surface 13e of second element body 3 in plate thickness direction T (FIG. 9) ) and (3′) the length L1 of the coining surface 13f in the plate thickness direction T of the processed product 1. and the plate thickness t1 of the cut end portion 13 of the processed product 1, the amount of processing is adjusted so that the ratio L1/t1 is 0.38 or less.

On the other hand, in Comparative Examples 1 to 12 in which corrosion resistance was evaluated only by punching, the fracture surface length W3 exceeded 0.5 mm, and the number of days until red rust occurred at the cut end was less than 60 days. Corrosion resistance is inferior to that of

In Comparative Examples 13 to 16, the cut end was subjected to coining from the fracture surface side after punching, but since the C surface dimension during coining was small, the fracture surface length after coining The width (W3) exceeded 0.5 mm. The number of days until the occurrence of red rust on the cut end surface was less than 60 days, and the corrosion resistance was inferior to that of the examples.

In Comparative Examples 17 and 18, similarly to Examples 10 and 21, the fracture surface length W1 after punching is as large as 1.5 mm or more. In Examples 10 and 21, coining was performed by adjusting the amount of processing as described above, but in Comparative Examples 17 and 18, the ratio L1/W1 exceeded 1.0, and the ratio L1/t1 was 0.38. We perform coining processing to exceed As a result, the ratio Z2/t1 between the length Z2 of the sagging 13c in the plate thickness direction T toward the lower surface 13b of the cut end 13 with respect to the upper surface 13a of the cut end 13 and the plate thickness t1 of the cut end 13 is -0.11, which is a large negative value. In Comparative Examples 17 and 18, it was evaluated that excessive deformation of the cut end portion 13 may cause problems.

From the above results, in the cutting process in which punching is performed and then coining is performed from the opposite fracture surface side, by setting the fracture surface length W3 after coining to 0.5 mm or less, the cut end surface having good corrosion resistance can be obtained. was confirmed to be obtained. Also, the effectiveness of adjusting the amount of coining was confirmed.

Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention belongs can conceive of various modifications or modifications within the scope of the technical idea described in the claims. It is understood that these also naturally belong to the technical scope of the present invention.

1: processed product 2: first element 3: second element 4: die 5: punch 7: pad 13: cut edge 13a: upper surface 13b: lower surface 13c: sag 13d: sheared surface 13e: fractured surface 13f: coining Surface 13h: Plated layer 13i: Corner

Claims (10)

A processed product made of a plated steel sheet having a plated layer on the surface and having a cut edge along the thickness direction of the processed product,
The cut end has a sag, a sheared surface, a fractured surface and a coining surface in this order in the plate thickness direction of the cut end from the upper surface side to the lower surface side,
The length W3 of the fractured surface between the sheared surface and the coined surface in the plate thickness direction of the cut edge is more than 0 mm and 0.5 mm or less,
The ratio L1/W2 between the length L1 of the coining surface in the plate thickness direction and the distance W2 between the lower surface of the cut end portion and the upper end of the fractured surface is 0.95 or less.
Processed goods. 2. The processed product according to claim 1, wherein a ratio L1/t1 between the length L1 of the coining surface in the thickness direction and the thickness t1 of the cut edge is 0.38 or less. A processed product made of a plated steel sheet having a plated layer on the surface and having a cut edge along the thickness direction of the processed product,
The cut end has a sag, a sheared surface, a fractured surface and a coining surface in this order in the plate thickness direction of the cut end from the upper surface side to the lower surface side,
The length W3 of the fractured surface between the sheared surface and the coined surface in the plate thickness direction of the cut edge is more than 0 mm and 0.5 mm or less,
A ratio L1/t1 between the length L1 of the coining surface in the plate thickness direction and the plate thickness t1 of the cut end is 0.38 or less.
Processed goods. The ratio Z2/t1 between the sagging length Z2 in the plate thickness direction toward the lower surface of the cut end with respect to the upper surface of the cut end and the plate thickness t1 of the cut end is -0. 4. The processed product according to any one of claims 1 to 3, which is 1 or more and 0.25 or less. The plating layer wraps around the coining surface from the lower surface of the cut end, and the distance W2 between the lower surface of the cut end and the upper end of the fracture surface in the plate thickness direction and the plate The processed product according to any one of claims 1 to 4, wherein a difference W2-L2 from the distance L2 between the lower surface and the upper end of the plating layer in the thickness direction is 1.4 mm or less. 6. A workpiece according to any one of claims 1 to 5, wherein the distance W2 between the lower surface of the cut edge and the upper edge of the fractured surface is 1.6 mm or less. A processed product manufacturing method for manufacturing a processed product using a plated steel sheet having a plated layer on the surface as a material and having a cut edge along the plate thickness direction of the processed product,
A cutting step for obtaining a second element by performing a cutting process once using a die and a punch on the portion to be cut of the first element formed from the material, wherein the portion to be cut is It is a flat plate-shaped portion including a portion to be the cut end portion, and the cut end portion of the second element has sagging, a sheared surface, and a fracture surface in the plate thickness direction of the cut end portion of the second element. a cutting step, comprising in order;
A coining step for obtaining a processed product in which a coining surface is formed on the corner portion by performing a coining process of pressing the corner portion of the cut end portion of the second element on the fracture surface side against a pad, The amount of processing is adjusted so that the ratio L1/W1 of the length L1 of the coining surface in the plate thickness direction and the length W1 of the fracture surface of the second element in the plate thickness direction is 1.0 or less. and a coining step of performing the coining process with
The cut end portion of the processed product has sagging, a sheared surface, a fractured surface, and the coined surface in the plate thickness direction of the cut end portion of the processed product from the upper surface side to the lower surface side, The length W3 of the fracture surface between the shear surface and the coining surface in the plate thickness direction of the cut end of the processed product is more than 0 mm and 0.5 mm or less.
Processed product manufacturing method. In the coining step, the amount of processing is adjusted so that the ratio L1/t1 of the length L1 of the coining surface in the plate thickness direction to the plate thickness t1 of the cut end portion is 0.38 or less. 8. The method of manufacturing a processed product according to claim 7, wherein A processed product manufacturing method for manufacturing a processed product using a plated steel sheet having a plated layer on the surface as a material and having a cut edge along the plate thickness direction of the processed product,
A cutting step for obtaining a second element by performing a cutting process once using a die and a punch on the portion to be cut of the first element formed from the material, wherein the portion to be cut is The cut end portion of the second element is a plate-like portion including the cut end portion. a cutting step;
A coining step for obtaining a processed product in which a coining surface is formed on the corner portion by performing a coining process of pressing the corner portion of the cut end portion of the second element on the fracture surface side against a pad, Coining is performed by adjusting the amount of processing so that the ratio L1/t1 of the length L1 of the coining surface in the thickness direction and the thickness t1 of the cut end of the processed product is 0.38 or less. and
The cut end portion of the processed product has sagging, a sheared surface, a fractured surface, and the coined surface in the plate thickness direction of the cut end portion of the processed product from the upper surface side to the lower surface side, The length W3 of the fracture surface between the shear surface and the coining surface in the plate thickness direction of the cut end of the processed product is more than 0 mm and 0.5 mm or less.
Processed product manufacturing method. In the coining step, the length Z2 of the sagging in the plate thickness direction toward the lower surface of the cut end with the upper surface of the cut end of the processed product as a reference and the plate of the cut end of the processed product The processed product according to any one of claims 7 to 9, wherein coining is performed by adjusting the processing amount so that the ratio Z2/t1 to the thickness t1 is −0.1 or more and 0.25 or less. Production method.

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