TWI808469B - Processed product and process product manufacturing method - Google Patents

Abstract

The present invention is a processed product, which uses a plated steel sheet having a plated layer on its surface as a blank and has a cut end along the thickness direction of the processed product. The cut end has a sag, a shear surface, and a fracture surface in this order in the thickness direction of the cut end, or has a sag and a shear surface in this order. The sag length Z in the plate thickness direction of the cut end is 0 times to less than 0.10 times the plate thickness t1 of the cut end of the processed product.

Description

Processed product and process product manufacturing method

The present invention relates to a method for manufacturing a processed product and its processed product. The method for manufacturing a processed product is a method for manufacturing a processed product that uses a plated steel plate with a plated layer on its surface as a blank and has a cut end.

In recent years, the use of plated steel sheets with a plated layer on the surface as raw materials for machine parts such as automobiles and home appliances has gradually increased. By using a plated steel sheet as a blank, surface treatment after forming a processed product can be omitted, and manufacturing cost can be suppressed. Also, by omitting the surface treatment after forming, it is possible to avoid the deterioration of the dimensional accuracy of the parts caused by the surface treatment after forming. The point of omitting surface treatment after molding has been studied especially for parts requiring high dimensional accuracy, such as motor housings.

When the surface treatment after forming is omitted, there will be an area where the original steel plate is exposed at the cut end of the processed product. Depending on the environment of the processed product, red rust may occur in the area where the original steel plate is exposed. Red rust will deteriorate the appearance of processed products. In addition, as time passes, the area where red rust occurs expands, so there is also a possibility that the strength of processed products will decrease due to red rust. Especially in the case of home appliances, there is also the possibility of electrical short circuits due to rust falling off.

In addition, screw holes are sometimes provided on the flange of extended processed products such as motor covers, and the screw holes are used to fix the processed product to other machines. If the flatness around the screw hole is poor, there may be concerns that the fastening force will decrease. When cutting the flange part to ensure the flatness around the screw hole, the size of the flange part should be set larger in consideration of the sagging dimension of the cut end part. On the other hand, if the size of the flange portion is increased, it will become the main cause of the increase in the weight of the billet.

As a method of improving the antirust ability of the cut end of the processed product, for example, Patent Document 1 proposes a method of punching a Zn-based plated steel sheet with a thickness of 2 mm or less using a die having a radius of curvature of 0.1 to 0.5 times the thickness of the Zn-based plated steel sheet on the shoulder of a punch or a die, whereby the sheared surface ratio of the punched end surface after punching is 90% or more, and the zinc coating rate of the sheared surface is 50% or more.

Also, Patent Document 2 proposes a method of cutting a Zn-based plated steel sheet using a die to obtain a processed product. Regardless of the thickness of the Zn-based plated steel sheet, the die sets the punching clearance to 1 to 20% of the sheet thickness, and the shoulder of the punch or die has a radius of curvature greater than 0.12 times the thickness of the Zn-based plated steel sheet. By cutting the Zn-based plated steel sheet using the die, the sag Z of the cut end surface is obtained. Above and the sagging X is more than 0.45×plate thickness processed products.

In addition, Patent Document 3 proposes a method of half-cutting a plated steel sheet to 60 to 95% of the plate thickness under negative clearance, and shearing from the opposite side of the half-cut by flat pressing to obtain a product with end surface corrosion resistance.

In addition, Patent Document 4 discloses a method of pressing a sheet metal. The method includes: a first step, using the first punch and a first die to make a shaving allowance on the final processed surface of the punched part of the metal sheet, so as to perform a half-cutting process on the metal sheet; More than 70% of the sheared surface.

In addition, Patent Document 5 describes a shear drilling method in which the first step is performed under negative clearance, and then the second step is performed under positive clearance using a punch and die that do not impart roundness (R) to the blade.

prior art literature

patent documents

Patent Document 1: Japanese Patent No. 5272518

Patent Document 2: Japanese Patent No. 6073025

Patent Document 3: Japanese Patent Laid-Open No. 2002-321021

Patent Document 4: Japanese Patent Laid-Open No. 2004-174542

Patent Document 5: Japanese Patent Laid-Open No. 11-254055

However, the method described in the above-mentioned Patent Document 1 is aimed at steel sheets with a thickness of 2 mm or less. When a steel sheet with a thickness of more than 2 mm is used as a blank, the zinc coverage of the sheared surface will be insufficient, and it may be difficult to suppress the generation of red rust. Furthermore, it is also difficult to apply to a drawn-worked product such as a motor case that thickens the flange end.

In the method described in the above-mentioned Patent Document 2, a processed product in which the sag Z of the trimmed end portion is 0.10 or more of the plate thickness and the sag X is 0.45 or more times the plate thickness is obtained, so a large sag is involved. Therefore, the effective grounding area around the screw hole is reduced, and the fastening force of the fixing screw is reduced. On the other hand, if the dimension of the flange portion is increased in order to secure the flatness around the screw hole, it will become a factor of increase in the weight of the billet. Therefore, the above-described method may not be applicable to drawn processed products such as a motor case to which a flange portion is to be fixed.

In the method described in the above-mentioned Patent Document 3, the plated steel sheet is half-cut with a negative clearance, and sheared by flat pressing from the side opposite to the half-cut. Therefore, a fractured surface may be formed at the middle position in the plate thickness direction of the trimmed edge of the plated steel sheet, and whisker-like burrs may be generated during flat pressing, thereby degrading the shape quality.

The method described in the above-mentioned Patent Document 4 is a technique related to trimming, which is to make the final processed surface of the metal sheet good by forming the sheared surface large. Even if the method described in Patent Document 4 is used to trim the metal sheet with a plated layer on the surface, in the final processed surface There is almost no plating layer left on the surface, so the corrosion resistance of the final processed surface is low.

In the method described in the above-mentioned Patent Document 5, since the blades of the punch and the die used in the second step are not provided with roundness (R), even if a plated steel sheet is used as the blank, the effect of leaving the plated layer on the cut end surface cannot be expected.

Therefore, the present invention was made in view of the above problems, and an object of the present invention is to provide a processed product having good corrosion resistance and shape quality even when a plated steel sheet having a plate thickness of more than 2.0 mm is used as a blank, and a method for manufacturing the processed product.

In order to solve the above-mentioned problems, according to an aspect of the present invention, a processed product can be provided, which is a plated steel sheet having a plated layer on its surface as a blank and has a trimmed end portion along the thickness direction of the processed product. 0.70 or more, and the sag length Z in the thickness direction of the trimmed end is more than 0 times and less than 0.10 times the thickness t1 of the trimmed end of the processed product.

The length W1 of the fractured surface in the thickness direction of the trimmed end may be greater than 0 mm and not greater than 1.0 mm.

The length W1 of the fractured surface in the thickness direction of the trimmed end may be 0.5 mm or less.

The sag length X in the plane direction perpendicular to the thickness direction of the trimmed end is more than 0 times and less than 0.30 times the thickness t1 of the trimmed end of the processed product.

The length of the burr at the cut end can also be less than 0.2mm.

The trimmed end may also have a sag, a sheared surface, a fractured surface, and a sizing surface in sequence in the thickness direction of the trimmed end, or may have a sag, a sheared surface, and a sizing surface in sequence, and, in the thickness direction of the trimmed end, the length W2 of the fractured surface between the sheared surface and the sizing surface is greater than 0 mm and less than 0.5 mm.

Also, in order to solve the above-mentioned problems, according to another aspect of the present invention, a method for manufacturing a processed product is provided, which is a method for manufacturing a processed product using a plated steel plate with a plated layer on the surface as a blank and having a cut end; the method includes the following steps: a half-cutting step, using a first die and a first punch to half-cut the cut part of the first blank formed from the blank along the plate thickness direction, and the clearance between the first die and the first punch is set to a negative clearance; The cutting step is to use the second die and the second punch to fine-cut the first blank body after half-cutting from the same direction as the half-cutting, and obtain a processed product with a cut end along the thickness direction; when forming a cut end on the outer peripheral side of the processed product, the inner diameter of the second die is D₃₂Set as the inner diameter of the first die D₃₁As mentioned above, when forming the trimmed end on the inner side of the processed product, the outer diameter of the second die d₃₂Set as the outer diameter of the first die d₃₁The following; let the thickness of the cut part of the first blank body be t1 and let the remaining thickness of the cut part after the half-cutting step be t2, in the half-cutting step, the clearance C between the first die and the first punch_31-41Satisfy the following formula (a1), the radius of curvature R1 of the blade of the first die satisfies the following formula (a2), the pressing amount D of the first die or the first punch to the cutting part of the first blank satisfies the following formula (a3), and the distance between the first die and the first punch at the bottom dead center is C_PDSatisfy the following formula (a4); in the fine cutting step, the clearance C between the second die and the second punch_32-42The following formula (a5) is satisfied, and the radius of curvature R2 of the blade of the second die satisfies the following formula (a6).

-0.25×t1≦C _31-41 ≦-0.01‧‧‧(a1)

0.10×t1≦R1≦0.50×t1‧‧‧(a2)

D≧0.70×t1‧‧‧(a3)

C _PD ≧0.20‧‧‧(a4)

0.01≦C _32-42 ≦0.2×t2‧‧‧(a5)

0.25≦R2≦1.50×t2‧‧‧(a6)

Here, the unit of C _31-41 , C _PD , C _32-42 and R2 is mm.

In addition, in order to solve the above-mentioned problems, according to another aspect of the present invention, a method for manufacturing a processed product can be provided, which is used to manufacture a plated steel plate with a plated layer on the surface as a blank and has a cutting edge. A method for cutting a processed product at an end; the method includes the following steps: a half-cutting step, using a first die and a first punch to half-cut a cut portion of a first blank formed from a blank in the direction of plate thickness, and the clearance between the first die and the first punch is set to a negative clearance; and a fine-cutting step, using a second die and a second punch to fine-cut the half-cut first blank from the same direction as the half-cut, and obtain a cut end. For the processed product, the cutting surface of the cutting end is along the thickness direction; when the cutting end is to be formed on the outer peripheral side of the processed product, the inner diameter of the second die is D₃₂Set as the inner diameter of the first die D₃₁As mentioned above, when forming the trimmed end on the inner side of the processed product, the outer diameter of the second die d₃₂Set as the outer diameter of the first die d₃₁The following; let the thickness of the cut part of the first blank body be t1 and let the remaining thickness of the cut part after the half-cutting step be t2, in the half-cutting step, the clearance C between the first die and the first punch_31-41Satisfy the following formula (b1), the radius of curvature R11 of the blade of the first die satisfies the following formula (b2-1), the radius of curvature R12 of the blade of the first punch satisfies the following formula (b2-2), the pressing amount D of the first die or the first punch to the cutting part of the first blank satisfies the following formula (b3), the distance between the first die and the first punch at the bottom dead center is C_PDSatisfy the following formula (b4); in the fine cutting step, the clearance C between the second die and the second punch_32-42The following formula (b5) is satisfied, and the radius of curvature R2 of the blade of the second die satisfies the following formula (b6).

-0.35×t1≦C _31-41 ≦-0.10×t1‧‧‧(b1)

0.10×t1≦R11≦0.65×t1‧‧‧(b2-1)

0.10×t1≦R12≦0.65×t1‧‧‧(b2-2)

D≧0.70×t1‧‧‧(b3)

C _PD ≧0.20‧‧‧(b4)

0.01≦C _32-42 ≦0.2×t2‧‧‧(b5)

0.25≦R2≦1.50×t2‧‧‧(b6)

Here, the unit of C _31-41 , C _PD , C _32-42 and R2 is mm.

The above-mentioned method for manufacturing a processed product may further include a finishing step, which is to use the processed product obtained in the fine cutting step as the second blank body, and press the corner of the cut end of the second blank body against the pad to obtain A processed product with a fine-pressed surface formed at the corner.

When forming a tailor -cut part on the sides of the processing items, the absolute value of the difference _between the inner diameter D 31 in the first diameter D ₃₁ and the inner diameter D ₃₂ of the first punching mode should be set to 1.00mm or less; when the tailoring part of the interior side is formed, the absolute value of the difference between the outer diameter D ₃₂ of the 1st diameter D ₃₂ in the inner side of the processing item | D _{32- D 31} | Set to below 1.00mm.

In addition, the above-mentioned method of manufacturing a processed product may further include a preparatory step before the half-cutting step. The preparatory step is to form a first blank having a hollow side wall and a flange from a plate-shaped plated steel sheet.

As described above, according to the present invention, even when a plated steel sheet having a plate thickness of more than 2.0 mm is used as a raw material, a processed product having good corrosion resistance and shape quality can be obtained.

1,90: processed product

2: 1st embryo body

6: The second embryo body

7: Pads

8: fine pressing block

9: Embryo body

9a: The part of the embryo body that is more outward than the outer peripheral surface of the processed product

9b: The inner part of the embryo body than the inner peripheral surface of the processed product

10: Torso

11: protrusion

12: Flange

13:Cut ends

13a: upper surface

13b: Collapse

13c: shear plane

13d: fracture surface

13e: Burr

13f, 13f1: plating layer

13g: Corner

13h: Fine pressed noodles

13j: extended surface

13k: bottom surface

20: Flange embryo body

20a: remove part

31: The first die

31a: The side of the first die

32: The second die

32a: The side of the second die

41: 1st punch

41a: The side of the first punch

42: 2nd punch

42a: The side of the second punch

51: The first pressing plate

52: The second pressing plate

61: Outside die

63: Inner die

65: Punch

70: vertical wall

71: Bottom wall

72: Pressing surface

91: Outer peripheral surface

92: inner peripheral surface

101: side wall

103: top wall

121: screw hole

123: screw

900,910A,910B,910C: flat gasket

911,931: teeth

920,930: disc spring

940: plate

A: area

C _31-41 , C _32-42 : Clearance

C _PD : the distance between the first die and the first punch at the bottom dead center

D: amount of pressing

L: Plating component remaining length (plating layer length)

R1, R2, R11, R12: radius of curvature

T: Thickness direction of the flange

V1: The volume of the corner part compressed by the pressing surface

V2: the volume of the scouring space

W1: The length of the fractured surface in the thickness direction of the trimmed end, the length of the fractured surface in the thickness direction of the flange before sizing

W2: The length of the fracture surface between the shear surface and the sizing surface in the thickness direction of the trimmed end, the length of the fracture surface in the thickness direction of the flange after sizing

X: Sag size (the length of the sag in the plane direction perpendicular to the plate thickness direction of the trimmed end (flange))

Z: Sag size (the length of the sag in the thickness direction of the trimmed end (flange))

X, Y, Z: direction

t1: The plate thickness of the trimmed end of the processed product, the plate thickness of the trimmed part of the first blank, and the plate thickness of the flange (flange blank)

t2: The remaining plate thickness of the trimmed part after the half trimming step

Fig. 1 is a perspective view showing an example of a processed product manufactured by a method for manufacturing a processed product according to a first embodiment of the present invention.

2 shows the cut end 13 in the area A of the processed product 1 in FIG. 1, the left side is a cross-sectional view on the ZX plane including the central axis of the processed product, and the right side is a side view from the X direction.

FIG. 3 is a detail view of the cross-sectional view on the left side of FIG. 2 .

FIG. 4 is a graph showing the relationship between sag X and sag Z in FIG. 3 .

Fig. 5 is an explanatory diagram showing a method of manufacturing a processed product according to the embodiment.

Fig. 6 is an explanatory diagram showing a half-cutting step when the blade of a die used in the half-cutting step is made into an R shape.

FIG. 7 is an explanatory view showing a fine cutting step followed by the half cutting step shown in FIG. 6 .

Fig. 8 is an explanatory view showing the half-cutting step when the blades of the die and the punch used in the half-cutting step are made into an R shape.

FIG. 9 is an explanatory diagram showing a fine cutting step followed by the half cutting step shown in FIG. 8 .

Fig. 10 is an explanatory diagram showing the position of the screw hole formed by the difference in the size of the sag X in the plane direction.

Fig. 11 is an explanatory view showing a method of manufacturing a processed product according to a second embodiment of the present invention.

Fig. 12 is an explanatory view showing a sizing step.

Fig. 13 shows the cut end of the processed product after the sizing step, the left side is a cross-sectional view on the ZX plane including the central axis of the processed product, and the right side is a side view from the X direction.

Fig. 14 is a photograph showing an example of a trimmed end portion of a processed product after the sizing step.

Fig. 15 is an explanatory view showing the volume of the corner portion crushed by the pad in the coining step.

Fig. 16 is a perspective view showing an example of a processed product.

Fig. 17 is a perspective view showing another example of a processed product.

Fig. 18 is a perspective view showing another example of a processed product.

Fig. 19 is a perspective view showing another example of a processed product.

Fig. 20 is a schematic diagram showing an example of a cutting die for processing flat gaskets.

Fig. 21 is a schematic diagram showing the state of blanking the blank by using the cutting die of Fig. 20 .

Fig. 22 is a perspective view showing another example of a processed product.

The form used to practice the invention

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. In addition, in this specification and drawing, about the structural element which has substantially the same functional structure, the same code|symbol is attached|subjected, and repeated description is abbreviate|omitted.

[1. First Embodiment]

[1-1. Processed product]

First, a processed product 1 that is processed by the first embodiment of the present invention will be described based on FIG. 1 . The manufacturer of the product manufacturing method. FIG. 1 is a perspective view showing an example of a processed product 1 manufactured by a method for manufacturing a processed product according to a first embodiment of the present invention. The processed product 1 shown in FIG. 1 is a motor case made of a plated steel plate with a plated layer on its surface as a blank. The motor case shown in FIG. 1 can be formed by performing forming processing such as drawing processing on a plate-shaped plated steel sheet.

As shown in FIG. 1 , a processed product 1 according to this embodiment has a trunk portion 10 , a protrusion portion 11 , and a flange portion 12 .

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 . Depending on the direction in which the processed product 1 is used, the top wall 103 may also be called by other names such as the bottom wall. The XY plane cross-sectional shape of the trunk portion 10 of the processed product 1 shown in FIG. 1 is a perfect circle, but the present invention is not limited to the above example. The cross-sectional shape of the trunk portion 10 on the XY plane may be other shapes such as ellipse or polygon, for example.

The protrusion 11 is a protrusion protruding outward from the top wall 103 in the central axis direction (Z direction) of the trunk portion 10 . In addition, 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 trunk portion 10 (that is, the other end of the side wall 101 ) toward the radially outer side of the trunk portion 10 . The shape of the flange portion 12 can be freely determined. The flange part 12 of this embodiment extends over the entire area of the circumferential direction of the trunk part 10 and extends along the diameter direction of the trunk part 10 . In the flange portion 12 , a plurality of screw holes 121 are provided apart from each other along the circumferential direction of the trunk portion 10 . A screw 123 is inserted into the screw hole 121 . The processed product 1 can be fixed to an installation object by fastening it to an installation object such as a vehicle body using screws 123 .

The flange portion 12 of the present embodiment is formed by cutting the flange portion blank body (flange portion blank body 20 in FIG. 5 ), and the flange portion blank body has a larger outer diameter than that of the flange portion 12 finally formed on the processed product 1. That is, the processed product 1 of this embodiment has the trimmed end portion 13 on the outer periphery of the flange portion 12 .

Cutting processing includes cutting, punching and drilling. The cutting system is along the predetermined straight line or curve The processing of cutting the cutting object by the line. Punching is the process of punching out products from the cutting object. Opening is the process of punching out parts that are not intended to be products to obtain products with openings. The flange portion 12 shown in FIG. 1 can be obtained from a flange portion blank by punching.

As the plated steel sheet, plated steel sheets having various plating layers are preferably used. Various kinds of steel sheets can be used for 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. In particular, the plated steel plate is preferably a steel plate plated with a Zn-Al-Mg alloy. Here, the alloy plating preferably contains 80 mass % or more of Zn with respect to the total molar number of plating, and preferably contains 90 mass % or more of Zn.

The raw steel plate of the plated steel plate can be freely determined, for example, it can be very low carbon steel.

The lower limit of the plating adhesion of the plated steel sheet is preferably 30g/m ² , preferably 45g/m ² . Also, the amount of plating on the plated steel sheet is preferably 450 g/m ² as the upper limit, and preferably 190 g/m ² as the upper limit. In particular, by making the plating deposition amount more than 45 g/m ² , the plated metal becomes easy to cover the cut surface of the cut end portion 13 (the cut surface 13c in FIG. 2 ), thereby improving the corrosion resistance after cutting.

The plate thickness of the plated steel plate (the plate thickness of the original steel plate + the plated layer thickness) can be freely determined, and can be less than 2.0mm or greater than 2.0mm. The thickness of the plated steel sheet may be, for example, not less than 0.8 mm and not more than 6.0 mm, preferably not less than 2.0 mm and not more than 4.5 mm.

[1-2. Cutting end of processed product]

Next, the cut end portion 13 of the processed product 1 according to the present embodiment will be described based on FIGS. 2 to 4 . 2 shows the cut end portion 13 in the area A of the processed product 1 in FIG. 1 , the left side is a cross-sectional view on the ZX plane including the central axis of the processed product 1, and the right side is a side view from the X direction. FIG. 3 is a detail view of the cross-sectional view on the left side of FIG. 2 . FIG. 4 is a graph showing the relationship between sag X and sag Z in FIG. 3 . In addition, in FIGS. 2 and 3 , the plate thickness direction T of the flange portion 12 is set to be the same direction as the Z direction which is the central axis direction of the processed product 1 shown in FIG. 1 . In addition, description of the plating layer 13f is omitted in FIG. 2 .

For example, as shown in FIGS. 2 and 3 , the trimmed end portion 13 of the flange portion 12 of the processed product 1 has a sag 13b, a sheared surface 13c, a fractured surface 13d, and a burr 13e sequentially from the upper surface 13a in the thickness direction T of the flange portion 12. Furthermore, the processed product 1 preferably has no burr 13e, and the processed product 1 of this embodiment may also be a processed product 1 without the burr 13e.

The upper surface 13a is a surface (pressed-in surface) into which a cutting die is pressed when cutting the flange portion blank.

The sag 13b is a portion where the surface of the flange body (plated steel sheet) is deformed by tensile force when the flange body is pressed into the cutting die. In this specification, the dimension of the sag 13b in the thickness direction T of the flange portion 12 is referred to as "sag Z", and the dimension of the sag 13b in the plane direction perpendicular to the thickness direction T is referred to as "sag X".

The shearing surface 13c is the surface of the flange body after being sheared by the blade of the cutting die. The shear surface 13c is adjacent to the sag 13b in the plate thickness direction T of the flange portion 12 .

The fractured surface 13d is a surface where cracks generated in the flange body from the edge of the cutting die intersect and fracture. The fractured surface 13d is adjacent to the sheared surface 13c in the plate thickness direction T of the flange portion 12 .

The burr 13e is a portion where the flange portion blank is elongated or torn off when the fracture surface 13d is formed. The burrs 13e are adjacent to the fracture surface 13d in the plate thickness direction T of the flange portion 12 .

As will be described later, by cutting the flange portion blank 20 using the processed product manufacturing method of this embodiment, the sag 13b, fractured surface 13d, and burr 13e can be suppressed to be small.

As shown in FIG. 3 , in the method of manufacturing a processed product of this embodiment, the trimmed edge 13 is formed so that the plated layer 13f covers the sheared surface 13c from the upper surface 13a of the trimmed edge 13 . The plated layer 13f is stretched by the cutting die to cover the shearing surface 13c when the blade of the cutting die gradually cuts into the flange body. By covering with the plating layer 13f, at least a part of the sheared surface 13c is covered with the plating layer 13f. On the other hand, generation of red rust can be suppressed in the portion of the sheared surface 13c coated with the plating layer 13f. Moreover, when the plating layer 13f is a Zn-based plating layer, due to the sacrificial anti-corrosion effect of the Zn-based plating layer, even after plating The vicinity of the portion covered with the coating 13f can also suppress the generation of red rust.

At this time, in the processed product 1, the length L of the plating layer 13f covering at least a part of the sag 13b and the sheared surface 13c from the upper surface 13a of the cut end portion 13 is 0.7 times or more than the thickness t1 of the cut end portion 13 of the processed product 1. That is, the ratio L/t1 of the plating component remaining length L covered by the plating layer 13f on the sheared surface 13c to the plate thickness t1 of the cut end portion 13 of the processed product 1 is 0.70 or more. The length L of the plated layer 13f can also be said to be the distance between the upper surface 13a of the cut end portion 13 and the lower end of the plated layer 13f along the thickness direction T of the flange portion 12 . Moreover, as shown in FIG. 2 , 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 . Therefore, the plate thickness of the flange portion 12 may be expressed as "plate thickness t1" below.

The fractured surface 13d is a surface formed as a result of intersection of cracks generated in the flange body, and is a rough primary surface. Metal components of the steel raw material are exposed in the fractured surface 13d. It is difficult for the plated layer 13f covering the sheared surface 13c to cover the fractured surface 13d. Therefore, the fractured surface 13d is more likely to generate red rust earlier than other surfaces of the cut end portion 13 .

The inventors of the present invention conducted experiments by varying the plate thickness t1 of the flange portion 12 formed with the trimmed end portion 13 , trimming conditions, and surface treatment conditions in various ranges, and investigated the occurrence of red rust. As a result, it is conceived to obtain a processed product 1 in which when the plated steel sheet is cut, the plated layer 13f covers the sheared surface 13c from the upper surface 13a and the ratio L/t1 is set to 0.70 or more, and the length of the sag 13b (sag Z) in the thickness direction T of the flange portion 12 is greater than 0 times and less than 0 times the thickness of the flange 12 (that is, the thickness t1 of the trimmed end portion 13 of the processed product 1). .10 times. In addition, it can be seen that by the cutting process, it is not necessary to increase the size of the base material in order to secure the flat portion around the screw 123 required to fix the processed product 1, and it is possible to suppress the occurrence of red rust in the cut end portion 13 as time passes after the cutting process.

Here, the thickness of the flange portion 12 is equal to the thickness t1 of the cut end portion 13 of the processed product 1, and is defined as the outermost thickness of the flange portion 12 (however, it is defined as the thickness of the portion where the sag 13b does not occur). The length W1 of the fracture surface 13d along the plate thickness direction T of the flange portion 12 (hereinafter also referred to as "fracture surface length") is greater than 0mm and Just below 1.0mm. If the fracture surface length W1 is set to be 1.0 mm or less, even if red rust occurs on the fracture surface 13d, it is not conspicuous, so it can be judged that there is no practical problem. The fracture surface length W1 of the processed product 1 is preferably as small as possible, and may be 0.8 mm or less or 0.6 mm or less. It is more preferable to set the fracture surface length W1 of the processed product 1 to 0.5 mm or less, 0.3 mm or less, or 0.2 mm or less. Also, the ratio W1/t1 of the fracture surface length W1 to the plate thickness t1 of the trimmed end portion 13 of the processed product 1 may be less than 0.15, less than 0.10, less than 0.08, less than 0.06, or less than 0.04. Furthermore, the fracture surface length W1 of the processed product 1 may be 0 mm. That is, the cut end portion 13 of the processed product 1 may not have the fracture surface 13d. In this case, the trimmed end portion 13 has a sag 13b and a sheared surface 13c (or a burr 13e when a burr 13e is generated) in order from the upper surface 13a in the thickness direction T of the flange portion 12 .

In addition, in order to secure a flat portion around the screw 123, it is desirable to minimize the sag X as much as possible. The sag Z and the sag X are mutually correlated. Therefore, when the sag Z which is easy to measure is adjusted, the sag Z is preferably set to be smaller than the thickness t1 of the flange portion 12 , that is, the thickness t1 of the cut end portion 13 of the processed product 1 . Moreover, the plate thickness t1 of the flange portion 12 is also equal to the plate thickness of the flange portion blank body 20 . The smaller the sag Z, the better, and may be less than 0.08 times, less than 0.06 times, or less than 0.04 times the thickness of the flange portion 12, that is, the thickness t1 of the trimmed end portion 13 of the processed product 1.

An example of the relationship between the sag Z and the sag X at the cut end of the product is shown in FIG. 4, and the product is produced by punching in one step. Fig. 4 shows the relationship between the sag Z and the sag X of the trimmed end of the product after the blade of the cutting die to be pressed into the flange body has a radius of curvature of 0.01 to 0.30 in terms of the thickness ratio of the flange body, and the blanking process is performed by setting the clearance of the cutting die to 0.01 to 0.20 times the plate thickness. As shown in Fig. 4, if punching is performed in one step, the sag X that appears in the planar direction becomes about 3 to 4 times larger than the sag Z in the thickness direction. That is, if punching is performed in one step, the sag X in the planar direction will increase, and in order to secure a flat portion around the screw 123 required to fix the processed product 1 to the mounting object, it is necessary to additionally increase the trimming size by only the sag X. Therefore, the sag X is preferably set to the thickness of the flange portion 12 of the processed product 1, that is, the thickness The plate thickness t1 of the trimmed end portion 13 of the product 1 is more than 0 times and less than 0.30 times. The smaller the sag X, the better, and may be less than 0.25 times, less than 0.26 times, less than 0.15 times, less than 0.12 times or less than 0.10 times the thickness of the flange portion 12, that is, the thickness t1 of the trimmed end portion 13 of the processed product 1.

In addition, the length of the burrs 13e generated on the lower side of the fractured surface 13d of the cut end portion 13 of the processed product 1 can also be set to be less than 0.2mm. The burrs 13e may cause dents, electrical shorts, and the like. By setting the length of the burrs 13e to be less than 0.2 mm, the burrs are left as little as possible on the processed product 1, and the occurrence of dents, electrical shorts, and the like can be suppressed. The length of the burrs 13e is preferably less than 0.1 mm. Moreover, the length of the burrs 13e is preferably 0 mm, that is, no burrs 13e exist in the processed product 1 .

Therefore, in the processed product manufacturing method of this embodiment, instead of cutting in one step, the plated steel sheet is cut in two steps of a half-cutting step and a finishing cutting step. Thereby, increase of the sag 13b of the trimmed edge part 13 can be suppressed, and more plating layer 13f can coat the trimmed surface 13c. Hereinafter, the method of manufacturing a processed product according to this embodiment will be described.

[1-3. Processed product manufacturing method]

First, a method of manufacturing a processed product according to this embodiment will be described with reference to FIG. 5 . Fig. 5 is an explanatory view showing a method of manufacturing a processed product according to the present embodiment. As shown in FIG. 5 , the method for manufacturing processed products in this embodiment includes: a preparation step, a half-cutting step, and a fine-cutting step.

The preparation step is a step of preparing the first embryo body 2 . The first blank body 2 can be obtained by performing forming processing such as drawing processing on a plate-shaped plated steel sheet. That is, the first raw body 2 uses a plated steel sheet as a raw material similarly to the processed product 1 . The first blank 2 includes a flange blank 20 having a larger outer diameter than the flange 12 shown in FIG. 1 . The shape of the flange body 20 can be circular or non-circular when viewed from above. On the other hand, the first blank body 2 may have the same shape as that of the processed product 1 with respect to parts other than the flange portion blank body 20 . Furthermore, the preparatory steps are not integral to the practice of the invention. If the embryo body processed by a certain method can be obtained through a third party, the preparation step can be omitted.

The half-cutting step is a step of half-cutting the first embryo body 2 . In the half-cut step, The half cutting of the embryo body 20 of the flange portion is carried out. The so-called half-cutting refers to the processing of cutting the flange part blank body 20 to the halfway position along the plate thickness direction of the flange part blank body 20 . When the flange portion blank body 20 of the first blank body 2 is half-cut, the removed portion 20a which will become a non-product at last is cut from the flange portion blank body 20 halfway.

The fine-cutting step is a step of fine-cutting the first embryo body 2 . In the fine cutting step, the removed portion 20a of the flange portion blank 20 is trimmed and cut from the flange portion blank 20 . By cutting off the removed portion 20a, the flange portion 12 can be formed. That is, in the method for manufacturing a processed product of this embodiment, the processed product 1 is obtained from the first green body 2 prepared in the preparation step through the half-cutting step and the fine-cutting step. The screw holes 121 of the processed product 1 shown in FIG. 1 may be formed in the flange portion blank 20 at the stage of the first blank 2, or may be formed in the flange portion 12 after the trimming step.

In the half-cutting step and the fine-cutting step of the processed product manufacturing method of this embodiment, the flange portion blank body 20 is processed using a die and a punch. Hereinafter, for the details of the half-cutting step and the fine-cutting step, two forms depending on the blade shape of the die and punch used in the half-cutting step will be described. The blades of dies and punches are sometimes called the "shoulder".

In addition, in the following description, regarding the mold used to obtain the processed product 1 , for convenience, the mold on the pressing side is called a die and the mold on the side to be pressed is called a punch. The mold on the press-in side may be located above the embryo body, and may be located below. When moving in the horizontal direction, the die on the press-in side is also called a die and the die on the press-in side is called a punch. For example, the processed product 1 shown in FIG. 2 is cut by setting the upper mold as the mold on the press-in side. When the lower mold is set as the mold on the press-in side, that is, when the lower mold is used as the punching die, the cut end 13 of the processed product 1 is opposite to that in FIG. Thereby, the burr 13e will be located uppermost. That is, of the two opposing surfaces of the flange body 20 in the plate thickness direction, a die for pressing the surface of the processed product 1 on the side where the sag 13b is located is called a die, and a die for pressing the surface on the side where the burr 13e is located is called a punch.

If it is not clear which of the upper and lower (or left and right) dies is a die or a punch, the cut end 13 can be observed after actual cutting, and the die that presses the surface on the side where the sag 13b is located is called a die, and the die that presses the surface on the side where the burr 13e is located is called a punch.

When forming the trimmed end portion 13 on the outer peripheral side of the processed product 1 as shown in FIG. 2 , the die is located on the outer peripheral side of the punch. During processing, the inner surface of the die is opposite to the cutting end 13 , and the outer surface of the punch is flush with the cutting end 13 . On the other hand, for example, when cutting the inner peripheral surface of the flat gasket 900 shown in FIG. During processing, the outer surface of the die is opposite to the cutting end 13 , and the inner surface of the punch is flush with the cutting end 13 . In addition, when cutting the outer peripheral side and the inner peripheral side of the processed product 1 at the same time as shown in FIGS. 20 and 21 described later, in this embodiment, the die 61 and the die 63 on the press-in side are called a die, and the die 65 on the press-in side is called a punch.

(a. When the blade of the die used in the half-cutting step is made into an R shape)

First, the half-cutting step and the fine-cutting step when the blade of the die used in the half-cutting step is made into an R shape will be described with reference to FIGS. 6 and 7 . Fig. 6 is an explanatory diagram showing a half-cutting step when the blade of a die used in the half-cutting step is made into an R shape. FIG. 7 is an explanatory view showing a fine cutting step followed by the half cutting step in FIG. 6 .

(half cut step)

As shown in FIG. 6 , in the half-cutting step, the flange portion blank 20 of the first blank 2 is half-cut using the first die 31 and the first punch 41 . In FIG. 6 , a state in which the flange portion 12 is half-cut from the flange portion blank body 20 held by the first punch 41 and the first platen member 51 is shown as an aspect of the half-cutting. The first die 31 constitutes a cutting die that is pressed into the flange portion blank 20 during half cutting. In the present embodiment, the die for pressing the flange portion 12 of the flange body 20 is defined as the first punch 41 , and the die for pressing the removed portion 20a is defined as the first die 31 .

The clearance C _31-41 between the first die 31 and the first punch 41 is negative clearance. Here, the clearance C _31-41 represents the gap between the first die 31 and the first punch 41, as shown in FIG. Based on the state of no clearance (that is, when C _31-41 is zero), when viewed from the pressing direction of the first die 31 (that is, the thickness direction of the flange 12 and the Z direction), the clearance in the state where the first die 31 and the first punch 41 are separated is called positive clearance, and the clearance in the state where the first die 31 and the first punch 41 are partially overlapped is called negative clearance. In this specification, regarding the clearance between the die and the punch, a positive value indicates a positive clearance and a negative value indicates a negative clearance.

As shown in FIG. 6, the first die 31 and the first punch 41 for half-cutting the first blank 2 are arranged in such a manner that the first die 31 and the first punch 41 are partially overlapped when viewed from the pressing direction of the first die 31. If the clearance C _31-41 is set to a positive clearance, the cracks generated from the blades of the first die 31 and the first punch 41 may intersect as in the punching process performed once, and the removed portion 20a may be completely cut off from the flange body 20. In addition, the sag 13b of the trimmed end portion 13 becomes larger. By setting the clearance C _31-41 as a negative clearance, it is possible to prevent the removed portion 20a from being completely cut off from the flange portion blank 20 in the half-cutting step, thereby reducing the sagging 13b.

In addition, by setting the clearance C _31-41 as a negative clearance, a large hydrostatic stress is generated in the region sandwiched by the first die 31 and the first punch 41 . Therefore, in the stress generated when the first die 31 is pressed into the flange body 20, the ratio of the tensile stress generated between the material that becomes waste after cutting (that is, the removed portion 20a) and the flange material that becomes the flange portion 12 is reduced. As a result, the material that will become waste after the cutting process and which is in contact with the front end of the blade of the first die 31 flows easily from the front end of the blade of the first die 31 to the side 31a side of the first die 31, and the extent to which the plating layer 13f covers the shear surface 13c can be increased. In addition, as the ratio of the tensile stress decreases and the compressive stress increases, the material that would otherwise flow toward the waste is pushed back toward the flange portion 12 . As a result, the material also fills the portion that will become the sag 13b after cutting, and the sag 13b can also be reduced.

In the direction (X direction in FIG. 6 ) adjacent to the first die 31 and the first punch 41, the shorter the length of the material that will become waste after cutting, the easier it is for the material to flow from the front end of the blade of the first die 31 to the side surface 31a of the first die 31. Therefore, it is preferable to arrange the first die 31 so that the side surface 31a of the first die 31 is located within the range of twice the plate thickness of the flange portion blank 20 (that is, the flange portion 12) from the end of the flange portion blank 20, and perform half-cutting.

As shown in the following formula (a1), the clearance C _31-41 [mm] between the first die 31 and the first punch 41 is set to be -0.01 mm or less and -0.25 times or more than the thickness t1 [mm] of the flange portion blank 20 of the first blank body 2 (that is, the flange portion 12).

-0.25×t1≦C _31-41 ≦-0.01‧‧‧(a1)

If the clearance C _31-41 is less than -0.01mm, there will be no local positive clearance due to the sliding accuracy of the pressing machine or the center shift of the mold, etc., and the negative clearance can be maintained. As a result, cracks are not generated during half-cutting, and there is no case where a large fracture surface occurs due to full-cutting. On the other hand, if the clearance C _31-41 is more than -0.25 times the thickness t1 of the flange body 20, the forming load required for half-cutting will not increase, and the pressing capacity will not be exceeded. Therefore, the burden on the mold is also small, and the reduction in the life of the mold can be suppressed. The upper limit of the clearance C _31-41 may also be set to -0.05 times or -0.10 times the thickness t1 of the flange portion green body 20 . Furthermore, the upper limit of the clearance C _31-41 may be -0.20 times or -0.15 times the plate thickness t1 of the flange portion blank body 20 .

As shown in FIG. 6, the blade of the first die 31 is formed in an R shape having a curvature radius R1. Since the first die 31 is pressed into the flange body 20 as shown in FIG. 6 , the blade of the first die 31 is formed into an R shape having a radius of curvature R1.

As shown in the following formula (a2), the radius of curvature R1 [mm] is 0.10 times to 0.50 times the thickness t1 [mm] of the flange part blank body 20 (that is, the flange part 12 ) of the first blank body 2 .

0.1×t1≦R1≦0.5×t1‧‧‧(a2)

If the radius of curvature R1 is at least 0.10 times the plate thickness t1, the plated layer 13f can be Under the circumstances, a large hydrostatic stress is generated under the negative clearance, so that the material in contact with the front end of the blade of the first die 31 flows from the blade of the first die 31 to the side 31a side of the first die 31. This material is the material directly below the first die 31 that will become waste. This flow reduces the ratio of the tensile stress generated between the material that will become waste after cutting (that is, the removed portion 20 a ) and the flange material that becomes the flange portion 12 in the stress generated when the first die 31 is pressed into the flange portion blank 20 . As a result, the sheared surface 13c can be covered with the plating layer 13f. On the other hand, if the radius of curvature R1 is set to 0.50 times or less than the plate thickness t1, the material on the edge of the first die 31 during half-cutting is reduced, and the formation of the fractured surface 13d can be reduced in the subsequent fine-cutting.

Also, the blade of the first punch 41 is formed in a square shape without roundness as shown in FIG. 6 . In this case, the blade of the first punch 41 may have a radius of curvature smaller than 0.1 times the thickness t1 of the flange portion blank 20 of the first blank 2 . Furthermore, the radius of curvature of the blade of the first punch 41 can also be set to be smaller than 0.06 times, less than 0.04 times or less than 0.02 times of the plate thickness t1 of the flange portion blank body 20 of the first blank body 2 as required.

As shown in the following formula (a3), the pressing amount D [mm] of the first die 31 pressed into the flange portion blank 20 of the first blank body 2 is set to 0.70 times or more than the plate thickness t1 [mm] of the flange portion blank 20 of the first blank body 2 (that is, the flange portion 12). As shown in FIG. 6, the pushing amount D is the moving amount of the first die 31, and the moving amount is calculated from the position where the first die 31 touches the upper surface of the flange portion blank 20 of the first blank 2 to the position where the pressing of the first punching die 31 stops (hereinafter this position is also referred to as "bottom dead point"). In addition, as shown in the following formula (a4), the distance C _PD [mm] between the first die 31 and the first punch 41 at the bottom dead center is set to be 0.20 mm or more.

D≧0.70×t1‧‧‧(a3)

C _PD ≧0.20‧‧‧(a4)

After half-cutting, the remaining thickness t2 of the flange body 20 (that is, the removed portion 20 a ) remaining on the first body 2 can be set to 0.30 times or less than the thickness t1 [mm] of the flange body 20 . Here, the remaining plate thickness t2 refers to the remaining plate thickness on the surface of the cut end portion 13 of the processed product 1 (this surface is the surface facing the inner peripheral surface of the first die 31 ). If the press-in amount D is more than 0.70 times the plate thickness t1, the fracture surface 13d will not be easily formed in the subsequent fine cutting. On the other hand, by ensuring that the distance C _PD between the first die 31 and the first punch 41 at the bottom dead center is 0.20 mm or more, it is possible to avoid the partial complete cutting caused by cracks during half cutting. In addition, the burden on the mold is small, and the reduction of the life of the mold can be suppressed. Also, the distance C _PD is set to be the minimum value of the distance between the first die 31 and the first punch 41 at the bottom dead center.

Furthermore, the pressing amount D [mm] of the first die 31 pressed into the flange portion blank 20 of the first blank body 2 (that is, the flange portion 12) may be 0.70 times or more of the plate thickness t1 of the flange portion blank 20 (that is, the flange portion 12) of the first blank body 2 as shown in the above formula (a3), and may be set at 0.95 times or less (0.70×t1≦D≦0.95×t1).

The remaining thickness t2 is the value obtained by subtracting the pressing amount D of the first die 31 into the flange body 20 from the thickness t1 of the flange body 20 (that is, the flange 12), and then adding the radius of curvature R1 to the obtained value (t2=t1-D+R1). Therefore, the remaining plate thickness t2 is different from the distance C _PD between the bottom dead centers of the first die 31 and the first punch 41 . If the press-in amount D is more than 0.70 times the plate thickness t1, the fracture surface 13d will not be easily formed in the subsequent fine cutting. On the other hand, if the press-in amount D is less than 0.95 times the plate thickness t1, there will be no cracks in half-cutting due to the sliding accuracy of the press machine or the center shift of the mold, etc., and there will be no large fracture surface due to complete cutting.

(fine cutting step)

As shown in FIG. 7 , in the fine-cutting step, the second die 32 and the second punch 42 are used to fine-cut the half-cut flange body 20 . In FIG. 7 , as an example of fine cutting, the flange portion 12 is fine blanked from the flange portion blank 20 held by the second punch 42 and the second platen member 52 . The second die 32 constitutes a cutting die that is pressed into the flange portion blank 20 during finishing cutting. In this embodiment, the die for pressing the portion of the flange body 20 to be the flange portion 12 is defined as the second punch 42 , and the die for pressing the removed portion 20 a is defined as the second die 32 . The second die 32 may be the same as the first die 31 . That is, the first die 31 used in the half-cutting step may be used as the second die 32 in the finishing cutting step.

The positional relationship between the second die 32 and the first blank body 2 is preferably the same as the positional relationship between the first die 31 and the first blank body 2 . When the positional relationship between them is different, for example, if the diameter of the second die 32 is larger than that of the first die 31 , a drop will occur at the cutting end 13 . Conversely, for example, if the diameter of the second die 32 is smaller than that of the first die 31, the second die 32 will contact the half-cut cut end produced in the half-cut step, and the second die 32 may scrape off the plating layer 13f covering the sheared surface 13c.

The fine cutting of this embodiment is carried out from the same direction as the half cutting. That is, after pressing the first die 31 into the flange portion blank 20 from the upper surface side of the flange portion blank 20 during half cutting as shown in FIG. 6, as shown in FIG. Thereby, the removed portion 20a can be separated from the flange portion blank body 20 . Thereby, the removed portion 20a can be separated from the flange portion blank body 20 .

The clearance C _32-42 [mm] between the second die 32 and the second punch 42 is a positive clearance. The clearance C _{32 - 42} is represented by the distance between the side surface 32 a of the second die 32 and the side surface 42 a of the second punch 42 . Here, like the half-cutting step, the clearance in the state where the second die 32 and the second punch 42 are separated is called a positive clearance, and the clearance in a state where the second die 32 and the second punch 42 are partially overlapped is called a negative clearance.

As shown in the following formula (5), the clearance C _32-42 between the second die 32 and the second punch 42 is set to be more than 0.01 mm and less than 0.2 times the remaining thickness t2, which is the thickness of the removed portion 20a remaining on the flange portion blank 20 of the first blank 2 after half-cutting.

0.01≦C _32-42 ≦0.2×t2‧‧‧(5)

If the clearance C _32-42 is 0.01mm or more, even if the sliding accuracy of the press machine and the center shift of the mold occur during fine cutting, there is no possibility of damage to the second die 32 due to contact with the second punch 42 . On the other hand, if the clearance C _{32 - 42} is 0.2 times or less of the remaining plate thickness t2, the burrs 13e are less likely to be generated.

The blade of the second die 32 has an R shape having a curvature radius R2. Since the second die 32 is pressed into the portion of the flange body 20 to be trimmed as shown in FIG. 7 , the blade of the second die 32 is R-shaped with a radius of curvature R2. Again, the blade system of the 2nd punch 42 is set as shown in Figure 7 Show such a square without roundness. In this case, the blade of the second punch 42 may have a radius of curvature smaller than 0.25 mm, smaller than 0.15 mm, smaller than 0.10 mm, or smaller than 0.05 mm. Or, the radius of curvature of the blade of the second punch 42 can also be set to be less than 0.1 times of the plate thickness t1 of the flange portion blank body 20 of the first blank body 2, and can also be set to be less than 0.06 times, less than 0.04 times or less than 0.02 times as required.

As shown in the following formula (6), the radius of curvature R2 [mm] is 0.25 mm or more and 1.50 times or less of the remaining plate thickness t2 of the half-cut part.

0.25≦R2≦1.50×t2‧‧‧(6)

If the radius of curvature R2 is 0.25 mm or more, the second die 32 will not scrape off the plating layer 13f covering the sheared surface 13c. On the other hand, if the radius of curvature R2 is 1.50 times or less the remaining plate thickness t2, the burrs 13e are less likely to be formed.

Furthermore, when the cut end is to be formed on the outer peripheral side of the processed product 1, the inner diameter D ₃₂ of the second die 32 is set to be greater than or equal to the inner diameter D ₃₁ of the first die _{31 ;} Specifically, when forming the trimmed _end on the outer peripheral side of the processed product ₁ , the absolute value | _D32 - _D31 | When forming the trimmed end portion on the inner peripheral side _of the processed product 1, the absolute value | _{d 32 −d 31} | Thereby, the drop can be reduced to obtain a good cut section. The drop is produced by the diameter difference _D32 - _D31 or _d32 - _d31 of the dies 31 and 32 at the cut end 13 of the processed product 1 in order to implement the semi-cutting step and the fine-cutting step twice.

In addition, in terms of the quality of the processed product 1, _the absolute value | _{D32 - D31} | Also, the upper limit of the absolute values of the diameter differences |D ₃₂ -D ₃₁ | and |d ₃₂ -d ₃₁ | should be as small as possible, and may be 0.75mm, 0.50mm, 0.35mm or 0.20mm. The lower limit of the absolute value of the diameter difference |D ₃₂ -D ₃₁ | and |d ₃₂ -d ₃₁ | is 0 mm. Furthermore, the smaller the drop produced at the cut end portion 13 of the processed product 1, the better, and it may be 0.5 mm or less. The upper limit of the drop produced at the cut end portion 13 of the processed product 1 can also be set to 0.4mm, 0.3mm, 0.2mm or 0.1mm according to requirements.

(b. When the blades of dies and punches used in the half-cutting step are R-shaped)

Next, the half-cutting step and the fine-cutting step when the blades of the punches and punches used in the half-cutting step are R-shaped will be described with reference to FIGS. 8 and 9 . Fig. 8 is an explanatory view showing the half-cutting step when the blades of the die and the punch used in the half-cutting step are made into an R shape. FIG. 9 is an explanatory diagram showing a fine cutting step followed by the half cutting step in FIG. 8 .

(half cut step)

As shown in FIG. 8 , in the half-cutting step, the flange portion blank 20 of the first blank 2 is half-cut using the first die 31 and the first punch 41 . In FIG. 8 , as an example of half-cutting, the same as in FIG. 6 , the flange portion 12 is half-cut from the flange portion blank 20, which is clamped by the first punch 41 and the first platen member 51. The first die 31 constitutes a cutting die that is pressed into the flange portion blank 20 during half cutting. In the present embodiment, the die for pressing the flange portion 12 of the flange body 20 is defined as the first punch 41 , and the die for pressing the removed portion 20a is defined as the first die 31 .

The clearance C _31-41 between the first die 31 and the first punch 41 is a negative clearance. Therefore, as shown in FIG. 8, the first die 31 and the first punch 41 for half-cutting the first blank body 2 are arranged in such a manner that the first die 31 and the first punch 41 are partially overlapped when viewed from the pressing direction of the first die 31. By setting the clearance C _31-41 as a negative clearance, it is possible to prevent the removed portion 20a from being completely cut off from the flange portion blank 20 in the half-cutting step, thereby reducing the sag 13b. Also, the meanings of clearance C _31-41 , negative clearance, and positive clearance in this form b are the same as in the above-mentioned form a.

In addition, by setting the clearance C _31-41 as a negative clearance, a large hydrostatic stress is generated in the region sandwiched by the first die 31 and the first punch 41 . Therefore, in the stress generated when the first die 31 is pressed into the flange body 20, the ratio of the tensile stress generated between the material that becomes waste after cutting (that is, the removed portion 20a) and the flange material that becomes the flange portion 12 is reduced. As a result, the material that will become waste after the cutting process is in contact with the front end of the blade of the first die 31 will easily flow from the front end of the blade of the first die 31 to the side 31a side of the first die 31, thereby increasing the extent to which the plating layer 13f covers the sheared surface 13c. In addition, as the ratio of the tensile stress decreases and the compressive stress increases, the material that would otherwise flow toward the waste is pushed back toward the flange portion 12 . As a result, the material also fills the portion that will become the sag 13b after cutting, and the sag 13b can also be reduced.

In the direction (X direction in FIG. 8 ) adjacent to the first die 31 and the first punch 41, the shorter the length of the material that will become waste after cutting, the easier it is for the material to flow from the front end of the blade of the first die 31 to the side surface 31a of the first die 31. Therefore, the first die 31 is arranged so that the side surface 31a of the first die 31 is located within a range of not more than twice the thickness of the flange portion blank 20 (that is, the flange portion 12) from the end of the flange portion blank 20, and half-cutting is performed.

As shown in the following formula (b1), the clearance C _31-41 [mm] between the first die 31 and the first punch 41 is set to -0.10 times or less and -0.35 times or more of the plate thickness t1 [mm] of the flange portion blank body 20 (that is, the flange portion 12 ) of the first blank body 2 .

-0.35×t1≦C _31-41 ≦-0.10×t1‧‧‧(b1)

If the clearance C _31-41 is -0.10 times or less the plate thickness t1 of the flange body 20, a large hydrostatic stress will be generated in the region sandwiched by the first die 31 and the first punch 41, and the ratio of the tensile stress will decrease. As a result, cracks are generated during the half-cutting, and the large fracture surface caused by the full-cutting disappears, so that the removed portion 20a can be prevented from being completely cut off from the flange portion blank 20 in the half-cutting step. On the other hand, if the clearance C _31-41 is more than -0.35 times the thickness t1 of the flange body 20, the forming load required for half-cutting will not increase, and the pressing capacity will not be exceeded. Therefore, the burden on the mold is also small, and the reduction in the life of the mold can be suppressed. The clearance C _31-41 is preferably -0.15 times or less or -0.20 times or less the plate thickness t1 of the flange portion blank body 20 . Furthermore, the clearance C _31-41 may be -0.30 times or more or -0.25 times or more the plate thickness t1 of the flange part blank body 20.

As shown in FIG. 8 , in this embodiment, the blades of the first die 31 and the first punch 41 are R-shaped. As shown in the following equations (b2-1) and (b2-2), the radius of curvature R11 [mm] of the blade of the first die 31 and the radius of curvature R12 [mm] of the blade of the first punch 41 are set at 0.10 times or more and 0.65 times or less of the plate thickness t1 [mm] of the flange portion blank body 20 (that is, the flange portion 12 ) of the first blank body 2 . Also, the radius of curvature R11 of the blade of the first die 31 and the radius of curvature R12 of the blade of the first punch 41 may be the same or different.

0.10×t1≦R11≦0.65×t1‧‧‧(b2-1)

0.10×t1≦R12≦0.65×t1‧‧‧(b2-2)

If the radii of curvature R11 and R12 are more than 0.10 times the plate thickness t1, a large hydrostatic stress can be generated under the negative clearance without scraping off the plating layer 13f, so that the waste material directly below the first die 31 flows from the blade of the first die 31 to the side surface 31a of the first die 31. This flow reduces the ratio of the tensile stress generated between the material that will become waste after cutting (that is, the removed portion 20 a ) and the flange material that becomes the flange portion 12 in the stress generated when the first die 31 is pressed into the flange portion blank 20 . As a result, the sheared surface 13c can be covered with the plating layer 13f. On the other hand, if the radii of curvature R11 and R12 are set to be less than 0.65 times the plate thickness t1, the material on the edge of the first die 31 will be reduced during half-cutting, and the formation of the fractured surface 13d in the subsequent fine cutting can be reduced.

As shown in the following formula (b3), the pressing amount D [mm] of the first die 31 pressed into the flange portion blank 20 of the first blank 2 (that is, the flange portion 12) is set to 0.70 times or more than the plate thickness t1 [mm] of the flange portion blank 20 of the first blank 2 (that is, the flange portion 12). The pushing amount D is the moving amount of the first die 31, and the moving amount is calculated from the position where the first punching die 31 contacts the upper surface of the flange portion blank body 20 of the first blank body 2 until the position (bottom dead center) where the pressing of the first punching die 31 stops. As shown in the following formula (b4), the distance C _PD [mm] between the first die 31 and the first punch 41 at the bottom dead center is set to 0.20 mm or more.

D≧0.70×t1‧‧‧(b3)

C _PD ≧0.20‧‧‧(b4)

After the half-cutting, the remaining plate thickness t2 of the removed portion 20a remaining on the flange portion blank 20 of the first blank body 2 can be set to be 0.30 times or less than the plate thickness t1 [mm] of the flange portion blank 20 . If the press-in amount D is more than 0.70 times the plate thickness t1, the fracture surface 13d will not be easily formed in the subsequent fine cutting. On the other hand, by ensuring that the distance C _PD between the first die 31 and the first punch 41 at the bottom dead center is 0.20 mm or more, it is possible to avoid the partial complete cutting caused by cracks during half cutting. Also, the distance C _PD is set to be the minimum value of the distance between the first die 31 and the first punch 41 at the bottom dead center.

Compared with the case where only one of the first die 31 and the first punch 41 has an R-shaped blade as shown in FIG. That is, compared with the case where only one of the blades of the first die 31 or the first punch 41 is R-shaped as shown in FIG.

In the case where only the blade of the first die 31 is R-shaped as in the above-mentioned form a, if the pressing amount D of the first die 31 is set to be equal to or greater than the thickness t1 of the flange portion 12, the blade of the first die 31 will contact the blade of the first punch 41. Therefore, in the above-mentioned form a, the pressing amount D of the first die 31 cannot be set to be equal to or greater than the plate thickness t1 of the flange portion 12 . However, if the blades of the first die 31 and the first punch 41 are R-shaped, as shown in FIG. Therefore, the trimming amount of the flange portion blank 20 can be set larger than that of the form a, and the ratio of the shearing surface 13c in the trimmed end portion 13 can be increased. Thereby, more of the plating layer 13f can cover the cut surface 13c, so that the ratio of the cut end portion 13 covered by the plating layer 13f can be increased. In addition, since the remaining plate thickness t2 becomes smaller, the trimming amount in the fine trimming step becomes smaller, and it is possible to avoid a state where there is no residual plating layer in a part of the trimmed portion.

(fine cutting step)

As shown in FIG. 9 , in the fine-cutting step, the second punch 32 and the second punch 42 are used to fine-cut the half-cut flange body 20 . The fine cutting step can be performed in the same manner as the fine cutting step shown in FIG. 7. The fine cutting step shown in FIG.

In FIG. 9 , as an example of fine cutting, the flange portion 12 is fine blanked from the flange portion blank 20 held by the second punch 42 and the second platen member 52 . The second die 32 constitutes a cutting die that is pressed into the flange portion blank 20 during finishing cutting. In this embodiment, the die for pressing the portion of the flange body 20 to be the flange portion 12 is defined as the second punch 42 , and the die for pressing the removed portion 20 a is defined as the second die 32 . The second die 32 may be the same as the first die 31 . That is, the first die 31 used in the half-cutting step may be used as the second die 32 in the finishing cutting step.

The positional relationship between the second die 32 and the first blank body 2 is preferably the same as the positional relationship between the first die 31 and the first blank body 2 . When the positional relationship between them is different, for example, if the diameter of the second die 32 is larger than that of the first die 31 , a drop will occur at the cutting end 13 . Conversely, for example, if the diameter of the second die 32 is smaller than that of the first die 31, the second die 32 will contact the half-cut cut end produced in the half-cut step, and the second die 32 may scrape off the plating layer 13f covering the sheared surface 13c.

The fine cutting of this embodiment is carried out from the same direction as the half cutting. That is, after pressing the first die 31 into the flange portion blank 20 from the upper surface side of the flange portion blank 20 during half cutting as shown in FIG. 8, as shown in FIG. Thereby, the removed portion 20a can be separated from the flange portion blank body 20 .

The clearance C _32-42 [mm] between the second die 32 and the second punch 42 is set to a positive clearance. As shown in the above formula (5), the clearance C _32-42 between the second die 32 and the second punch 42 is set to be more than 0.01 mm and less than 0.2 times the remaining thickness t2, which is the thickness of the removed part 20a remaining on the flange part blank 20 of the first blank 2 after half-cutting. If the clearance C _32-42 is 0.01 mm or more, the second die 32 will not be damaged due to contact with the second punch 42 even if the sliding accuracy of the press machine or the center shift of the mold occurs during fine cutting. On the other hand, if the clearance C _32-42 is 0.2 times or less of the remaining plate thickness t2, the burrs 13e are less likely to be generated.

The blade of the second die 32 has an R shape having a curvature radius R2. Since the second die 32 is pressed into the portion of the flange body 20 to be trimmed as shown in FIG. 9 , the blade of the second die 32 is R-shaped with a radius of curvature R2. In addition, the blade of the second punch 42 may be a square without roundness as shown in FIG. 9 , or may have a radius of curvature. If the blade of the second punch 42 is formed into a square shape without roundness, the burr generated at the tip of the fractured surface 13d can be made smaller. The radius of curvature of the blade of the second punch 42 can be set to be less than 1.00 mm, less than 0.50 mm, less than 0.20 mm, less than 0.10 mm or less than 0.05 mm. Or, the radius of curvature of the blade of the second punch 42 can also be set to be less than 0.3 times of the plate thickness t1 of the flange portion blank body 20 of the first blank body 2, and can also be set to be less than 0.1 times, less than 0.06 times, less than 0.04 times or less than 0.02 times as required.

As shown in the above formula (6), the radius of curvature R2 [mm] is set to be 0.25 mm or more and 1.50 times or less of the remaining plate thickness t2 of the half-cut part. If the radius of curvature R2 is 0.25 mm or more, the second die 32 will not scrape off the plating layer 13f covering the sheared surface 13c. On the other hand, if the radius of curvature R2 is 1.50 times or less the remaining plate thickness t2, the burrs 13e are less likely to be formed.

In the above, the method of manufacturing a processed product according to the first embodiment of the present invention has been described. According to this embodiment, the first blank body 2 is regarded as the cutting object, and the first blank body 2 is formed of a plated steel plate and has a flange portion blank body 20 that becomes the flange portion 12; and, it includes the following steps: a half-cutting step, using the first die 31 and the first punch 41 to half-cut the flange portion blank body 20 of the first blank body 2, and the clearance between the first die 31 and the first punch 41 is set to a negative clearance; and, the fine cutting step , use the second die 32 and the second punch 42 to fine-cut the semi-cut flange body 20 from the same direction as the half-cut, and obtain the processed product 1, which has the trimmed end 13 on the flange 12.

In the processed product 1 that has been cut through the above-mentioned two steps, the cut end of the flange portion 12 The portion 13 has a sag 13b, a sheared surface 13c, and a fractured surface 13d sequentially in the plate thickness direction T of the trimmed end portion 13. At least a part of the sheared surface 13c is covered by the plating layer 13f of the upper surface 13a. At this time, the ratio L/t1 of the plating component remaining length L covered by the plating layer 13f1 on the sheared surface 13c to the thickness t1 of the trimmed edge 13 of the processed product 1 is 0.70 or more, and the length of the sag 13b in the thickness direction T of the trimmed edge 13 is more than 0 times and less than 0.10 times the thickness t1 of the trimmed edge 13 of the processed product 1. As described above, the sag 13b of the cut end portion 13 of the processed product 1 is suppressed from becoming larger, and more plating layers 13f cover the cut surface 13c. Even in the case of using a plated steel sheet with a thickness of more than 2.0 mm as the blank, the corrosion resistance and shape quality can still be improved.

If the length of the sag 13b (sag X) in the plane direction (XY plane direction) can be reduced, the material used for the processed product 1 can be reduced. For example, as shown in FIG. 1 , a screw hole 121 into which a screw 123 for fixing the processed product 1 can be inserted is formed in the flange portion 12 so that the screw 123 can be fixed to the flat portion while avoiding the sag 13b. As shown on the upper side of FIG. 10 , if the sag X becomes larger, the distance from the end of the flange portion 12 to the screw hole 121 becomes longer, requiring additional material. On the other hand, as shown in the lower side of FIG. 10 , if the sag X is small, the distance from the end of the flange portion 12 to the screw hole 121 becomes shorter, and the material used to form the flange portion 12 can be reduced. As mentioned above, according to the method of manufacturing a processed product of this embodiment, there is no need to increase the size of the blank in order to secure the flat portion around the screw 123 required to fix the processed product 1 .

Moreover, the cut surface 13c can be covered with more plated layers 13f by the method of manufacturing a processed product of this embodiment, so red rust can be suppressed from occurring on the cut end portion 13 over time after the cutting process.

In addition, the clearance C _32-42 between the second die 32 and the second punch 42 is set to 0.01 mm or more and 0.2 times or less the remaining thickness t2 of the first blank 2 (flange blank 20 ) of the half-cut part. Thereby, it is possible to prevent the cutting die from contacting and being damaged during the finishing cutting, and to suppress the generation of the burrs 13e.

Also, the blade front end of the second die 32 to be pressed into the portion of the first blank 2 that becomes the target of fine trimming is provided with a curved shape, and the curved shape has a portion that is 0.25 mm or more and is half-cut. The radius of curvature R2 is less than 1.50 times the remaining plate thickness t2. Thereby, the cutting die can prevent the plating layer 13f covering the sheared surface 13c from being scraped off, and the generation of burrs 13e can be suppressed.

[2. Second Embodiment]

Next, a method for manufacturing a processed product according to a second embodiment of the present invention will be described with reference to FIG. 11 . Fig. 11 is an explanatory view showing a method of manufacturing a processed product according to a second embodiment of the present invention. As shown in FIG. 11 , the method for manufacturing processed products in this embodiment includes: a preparation step, a half-cutting step, a fine-cutting step, and a fine-pressing step.

The method for manufacturing a processed product of this embodiment is a method in which a sizing step is added to the method for manufacturing a processed product of the first embodiment shown in FIG. 5 . As shown in FIG. 11, also in this embodiment, the half-cutting step and the fine-cutting step are performed on the first embryo body 2 prepared in the preparation step in the same manner as in the first embodiment. Therefore, detailed description of the preparation step, half-cutting step, and fine-cutting step is omitted.

The sizing step is to use the processed product obtained in the sizing and cutting step as the 2nd green body 6, and carry out the sizing process on the 2nd green body 6. In the finishing step, after the fine cutting step, the corner 13g of the cut end 13 on the fractured surface 13d side is pressed against the pad (pad 7 in FIG. 12 ) to obtain a processed product 1 having a fine-pressed surface 13h formed at the corner. By sizing, the region of the fractured surface 13d of the rough primary surface can be reduced, and the region where red rust occurs can be suppressed. In addition, the burrs 13e can be flattened by sizing, and it is possible to more reliably suppress the burrs 13e from remaining in the processed product 1 .

The sizing step will be described in more detail with reference to FIGS. 12 to 14 . Fig. 12 is an explanatory diagram showing a sizing step. 13 shows the cut end of the processed product 1 after the sizing step, the left side is a cross-sectional view on the ZX plane including the central axis of the processed product 1, and the right side is a side view from the X direction. Fig. 14 is a photograph showing an example of the trimmed end of the processed product 1 after the sizing step. In addition, in FIG. 13, description of the plating layer 13f is abbreviate|omitted similarly to FIG.

As shown in FIG. 12 , in the coining step of the present embodiment, the trimmed end 13 of the second green body 6 is clamped with the pad 7 and the coining block 8 . The pad 7 has a vertical wall 70 , a bottom wall 71 and a pressing surface 72 .

The vertical wall surface 70 is arranged so that when the cut end 13 of the second blank body 6 is sandwiched by the pad 7 and the fine compacted block 8, it will face the shearing surface 13c of the second blank body 6 and be approximately parallel. Moreover, the vertical wall surface 70 is arrange|positioned parallel to the advancing and retreating direction (Z direction in FIG. 12) of the sizing block 8. As shown in FIG.

The bottom wall surface 71 is disposed so as to sandwich the second green body 6 against the sizing block 8 in the thickness direction of the flange portion 12 . Also, the bottom wall surface 71 extends below the vertical wall surface 70 (that is, on the side opposite to the sizing block 8 ) in a direction perpendicular to the vertical wall surface 70 .

The pressing surface 72 is a surface connecting the bottom wall surface 71 and the bottom wall surface 71 . The pressing surface 72 is provided for forming a sizing surface (the sizing surface 13h in FIG. 13 ) on the second blank body 6, and is formed in a shape corresponding to the shape of the sizing surface. For example, as shown in FIG. 13, when the sizing surface 13h is to be a planar chamfered surface (hereinafter referred to as "C surface"), it is only necessary to make the pressing surface 72 an inclined plane with respect to the vertical wall surface 70 and the bottom wall surface 71. Also, for example, when the sizing surface 13h is to be curved (either the pressing surface or the compressing surface; hereinafter referred to as "R surface"), the pressing surface 72 may be curved.

In the sizing step, as shown in FIG. 12 , the second green body 6 is clamped in the plate thickness direction T by the bottom wall surface 71 of the sizing block 8 and the pad 7 in a state where the trimmed end portion 13 of the second green body 6 is opposed to the vertical wall surface 70 of the pad 7 . Then, the precision pressing block 8 is pressed in towards the bottom wall surface 71, so that the second embryo body 6 is pressed down to the position where the bottom surface 13k of the second embryo body 6 contacts the bottom wall surface 71. Here, the corner portion 13g is pressed against the pressing surface 72 before the bottom surface 13k of the second blank body 6 contacts the bottom wall surface 71 . After the corner portion 13g is pressed against the pressing surface 72, the precision compacting block 8 is further pressed in so that the bottom surface 13k of the second blank body 6 contacts the bottom wall surface 71. The corner portion 13g is crushed by the pressing surface 72 to form a sizing surface 13h. And, the cut end portion 13 of the processed product 1 after the sizing step is, for example, as shown in the photograph of FIG. 14 .

The fine-pressed surface 13h is a smooth surface transferred from the surface of the pressing surface 72, and is less prone to red rust than the rough fractured surface 13d. The reason for this is presumed to be that moisture is less likely to stay on the sizing surface 13h because the surface roughness becomes smooth. In addition, it is presumed that the plated layer 13f on the bottom surface 13k side of the trimmed end portion 13 is thinly stretched to the stenciled surface 13h, which is also a factor that hardly generates red rust. by the fracture surface The corner portion 13g on the 13d side forms the sizing surface 13h, and the fracture surface length W2 (see FIG. 13 ) of the flange portion 12 in the plate thickness direction T after sizing is shorter than the fracture surface length W1 (see FIGS. 2 and 3 ) of the flange portion 12 in the plate thickness direction T before sizing. That is, the region of the fractured surface 13d which is the rough primary surface can be reduced by sizing, and the region where red rust occurs can be suppressed. In addition, the burrs 13e can be flattened by sizing, and it is possible to more reliably suppress the burrs 13e from remaining in the processed product 1 .

In the sizing step, the contact surface 72 is pressed against the corner portion 13g so that the length (fracture surface length) W2 of the fracture surface 13d between the shear surface 13c and the sizing surface 13h in the plate thickness direction T of the flange portion 12 of the processed product 1 is greater than 0mm and 0.5mm or less. By setting the fracture surface length W2 to be greater than 0 mm and not more than 0.5 mm, even if red rust occurs on the fracture surface 13d, it is not conspicuous, so it can be judged that there is no practical problem.

Furthermore, in the precision cutting step, it is preferable to obtain the second green body 6 whose fracture surface length W1 in the thickness direction T is less than 1.0 mm. By obtaining the second green body 6 whose fracture surface length W1 is less than 1.0 mm, the fracture surface length W2 can be more reliably set to 0.5 mm or less in the sizing step. The fracture surface length W2 of the processed product 1 is preferably as small as possible, and may be 0.4 mm or less or 0.3 mm or less. It is more preferable that the fracture surface length W2 of the processed product 1 is 0.2 mm or less or 0.1 mm or less. Also, the ratio W2/t1 of the fracture surface length W2 to the plate thickness t1 of the trimmed end portion 13 of the processed product 1 may be less than 0.15, less than 0.10, less than 0.08, less than 0.06, or less than 0.04. Furthermore, the fracture surface length W2 of the processed product 1 may be 0 mm. That is, the cut end portion 13 of the processed product 1 may not have the fracture surface 13d. That is, for example, as shown in FIG. 13, the trimmed edge 13 may have a sag 13b, a sheared surface 13c, a fractured surface 13d, and a sizing surface 13h sequentially in the thickness direction of the trimmed edge 13. Alternatively, the trimmed end portion 13 may have the sag 13b, the sheared surface 13c, and the sizing surface 13h sequentially in the plate thickness direction of the trimmed edge portion 13.

FIG. 15 is an explanatory diagram showing the volume of the corner portion 13g compressed by the pressing surface 72 of the pad 7 in FIG. 12 . As the precision pressing block 8 in FIG. 12 is pressed down toward the bottom wall 71 of the pad 7 , the corner 13g will contact the pressing surface 72 and be flattened. The material (raw steel) of the corner portion 13g that is crushed will move to the shear along the pressing surface 72. Cut surface 13c side. When the cut end portion 13 is pressed down to the position where the bottom surface 13k of the cut end portion 13 touches the bottom wall surface 71, depending on the position and angle of the pressing surface 72, the volume V1 of the corner portion 13g of the flange portion 12 compressed by the pressing surface 72 will change.

As shown on the upper side of FIG. 15 , in the sizing step, the volume V1 of the corner portion 13g crushed by the pressing surface 72 should be set to be smaller than the volume V2 of the sizing space, which is the space surrounded by the extension surface 13j of the shearing surface 13c, the fracture surface 13d, and the pressing surface 72. As shown in FIG. 12, the fractured surface 13d of the trimmed end portion 13 of the flange portion 12 is inclined relative to the vertical wall surface 70 with a gap therebetween. The volume V2 of the sizing space created by this gap becomes a space into which the material of the corner portion 13g flattened by the pressing surface 72 can flow. If the volume V2 of the sizing space is smaller than the volume V1 of the corner 13g crushed by the pressing surface 72, the material of the corner 13g crushed by the pressing surface 72 cannot be completely accommodated in the volume V2, and will move toward the upper part of the pad 7.

Therefore, by making the volume V1 smaller than the volume V2, it is possible to avoid the material of the corner portion 13g crushed by the pressing surface 72 protruding beyond the extension surface 13j of the shearing surface 13c. If the volume V1 is greater than the volume V2 as shown in the lower side of FIG. 15, the material of the corner portion 13g after being flattened by the pressing surface 72 protrudes beyond the extension surface 13j of the shearing surface 13c, and moves toward the upper part of the pad 7. If such a phenomenon occurs, the dimensional accuracy of the cut end portion 13 will deteriorate. Therefore, it is preferable to process so that the volume V1 becomes smaller than the volume V2 so that the corner portion 13g can be crushed by the pressing surface 72 .

As mentioned above, the manufacturing method of the processed product which concerns on 2nd Embodiment was demonstrated. According to this embodiment, as in the first embodiment, there is no need to additionally increase the size of the base material in order to secure a flat portion around the screw 123 necessary for fixing the processed product 1 . Furthermore, since the sheared surface 13c can be covered with many plating layers 13f, it is possible to suppress the red rust of the trimmed end portion 13 that occurs with the passage of time after the trimming process.

In addition, by performing the sizing step after the trimming step, the region of the fractured surface 13d which is the rough primary surface can be reduced, and the region where red rust occurs can be suppressed. In addition, since the burr 13e can be flattened by sizing, the burr 13e remaining on the processed product 1 becomes less than 0.2mm, which can be more reliable. The residue of the burr 13e is suppressed as much as possible. The length of the burrs 13e is preferably less than 0.1 mm, and preferably less than 0.05 mm or less than 0.01 mm. Moreover, the length of the burrs 13e is preferably 0 mm, that is, no burrs 13e exist in the processed product 1 .

[3. Example of processed product]

In the above-mentioned embodiment, the case where the processed product 1 is a motor case as shown in FIG.

The processed product 1 can also be, for example, an annular flat gasket 900 as shown in FIG. 16 . Moreover, the processed product 1 may be, for example, flat washers 910A, 910B, and 910C having tooth portions 911 as shown in FIG. 17 . Alternatively, the processed product 1 may be, for example, a wave-shaped circular disc spring 920 as shown in FIG. 18 . The disc spring 920 in FIG. 18 can be manufactured by, for example, processing the flat washer 900 shown in FIG. 16 into a wave shape. In addition, the processed product can also be, for example, a disc spring 930 having a tooth portion 931 as shown in FIG. 19 .

When the processed product 1 is various ring-shaped plate members as shown in FIGS. By applying the processed product manufacturing method of the above embodiment, in at least one of the outer peripheral portion and the inner peripheral portion, the ratio L/t1 of the plating component remaining length L of the sheared surface 13c covered by the plating layer 13f1 to the thickness t1 of the trimmed end portion 13 of the processed product 1 can be made 0.70 or more in the thickness direction T of the processed product 1, and the length of the sag 13b can be made smaller than 0.10 of the thickness t1 of the trimmed end portion 13 of the processed product 1. times.

For example, if the plating layer is to cover the sheared surfaces of the inner and outer peripheral surfaces of the flat gasket 900 shown in FIG. 16 , it may be processed using a cutting die as shown in FIGS. 20 and 21 . FIG. 20 is a schematic diagram showing an example of a cutting die for processing the flat gasket 900 . And, FIG. 21 is a schematic diagram, which shows the state after blanking the blank 9 by using the cutting die of FIG. 20 .

The cutting die shown in FIG. 20 is a die for manufacturing an annular processed product 90 such as a flat gasket 900. It has: a hollow cylindrical die (hereinafter referred to as "outer die") 61, a cylindrical die The die (hereinafter referred to as "inner die") 63 and the hollow cylindrical punch 65 for supporting the disc-shaped blank body 9 (refer to FIG. 21 ). The outer punch 61 and the inner punch 63 are arranged opposite to the punch 65 , and the blank 9 is cut by pressing the outer punch 61 and the inner punch 63 into the blank 9 supported by the punch 65 . The inner diameter of the outer die 61 corresponds to the outer diameter of the processed product 90 , and the outer diameter of the inner die 63 corresponds to the inner diameter of the processed product 90 . The blades on the inner peripheral surface of the outer die 61 and the outer peripheral surface of the inner die 63 have an R-shape with a radius of curvature. On the other hand, the edge portions of the inner peripheral surface and the outer peripheral surface of the punch 65 do not have an R shape.

If the blank body 9 is fine-cut using the above-mentioned cutting die, then as shown in FIG. Thereby, a processed product 90 (flat gasket 900 ) as shown in FIG. 20 can be formed. At this time, the ratio L/t1 of the plating component remaining length L covered by the plating layer to the thickness t1 of the trimmed end of the processed product 90 in the sheared surface of the outer peripheral surface 91 and the inner peripheral surface 92 of the processed product 90 is 0.70 or more, and the sag length in the thickness direction of the trimmed end portion can be made smaller than 0.10 times the thickness t1 of the trimmed end portion of the processed product 90.

In addition, the processed product 1 may also be, for example, a disc-shaped plate 940 as shown in FIG. 22 .

[Example]

(Example a. The case where only the blade of the die used in the half-cutting step is R-shaped)

The shoulder (that is, the blade) of the die in the half-cutting step is set to an R shape with a predetermined radius of curvature, and a sample of the processed product is produced by the method shown in Fig. 5 and Fig. 11 . The plated steel plate is a Zn-6%Al-3%Mg (mass ratio) alloy plated steel plate with a thickness of 1.4~3.8mm and a plating weight of 90g/m ² (one side) or 190g/m ² (one side). The semi-cutting process is carried out by using a circular die and a punch and using a platen to hold the plated steel sheet. The inner diameter D ₃₁ of the circular die is 85.00mm, and the diameter of the punch has been changed according to the clearance between the die and the punch. Fine cutting is carried out by using a die and a punch to hold the plated steel sheet using a platen. The shoulder (that is, the blade) of the die is set in an R shape with a predetermined radius of curvature. The punch has been changed in diameter D ₃₂ in response to the clearance C _32-42 between the die and the punch.

For each sample, measure sag Z, sag X, and the fracture surface length (W1) after precision cutting, and if sizing is performed, measure the fracture surface length (W2) after sizing. These are calculated by using a microscope to measure at 30° intervals on the circumference of the end surface of the processed product, and calculating the average of the measured values at a total of 12 points. In addition, for the case where the plating layer covered the cut end of each sample, the length L covered by the plating layer in the thickness direction of the plated steel sheet was measured from the cross-section of the central portion of the straight edge portion of the processed product. An electron probe microanalyzer (EPMA-WDS) was used to measure the length L of the plating layer in the trimmed end. In addition, it was judged that the presence of the plating layer was present in a part where the detection level of the Zn component was 3 times or more of the background. In addition, the object of measurement is the processed product or the 2nd green body after fine-cutting, and the processed product after fine-pressing.

In addition, in the trimmed end of each sample, the sag, the sheared surface, the fractured surface, and the stenciled surface are as shown in FIG. 14 , and more specifically, they appear as follows.

The sag appears in the state of a smooth surface formed by stretching the surface of the workpiece by applying a compressive (pressurizing) force after the die contacts the workpiece. As shown in FIG. 3 , when the cut end is viewed from the side, it has a curved shape.

The cut surface appears as a smooth surface at the cut end. The shear surface is caused by friction with the side of the die due to the compression (pressurization) force applied after the die touches the workpiece to cut into the workpiece. The sheared surface is produced by friction with the die, so it will show a metallic luster. In addition, fine sliding flaws in the form of streaks along the thickness direction were observed on the sheared surface.

The fractured surface is the surface where the cracks generated in the workpiece from the sheared surface side intersect and break, and it appears in the state of a matte rough surface. After the sheared surface of the processed material is formed, if the die cuts further into the processed material, the edge of the punch will generate cracks in the processed material, and at the same time, the edge of the punch will generate cracks in the processed material. The cracks generated by the punch and the die will meet each other and then penetrate. The surface where cracks are formed as described above becomes the fracture surface. The fracture surface is formed without contact between the punch and the die, so it becomes a matte rough surface. The fracture surface has a corresponding impact The inclination of the gap (clearance) between the head and the die.

The embossed surface appears in the state of a smooth surface after the unevenness of the fractured surface is flattened. The sizing surface is obtained by pressing a bevel-shaped or curved sizing die against the corner of the fracture surface from the lower surface side of the end of the fracture surface. The fine embossing surface is transferred through the surface roughness of the fine embossing mold, and becomes a smooth surface after the unevenness of the fracture surface is flattened.

As a method for specifying the sag, the sheared surface, the fractured surface, and the sizing surface at the cut end, for example, there is a method of observing and measuring the shape profile of the cut end using a microscope or a contour measuring machine (contracer) based on the above-mentioned characteristics.

From the viewpoint of securing the flatness around the set screw, the evaluation of "A (good)" when the sag Z of the trimmed end portion 13 was less than 0.10 times, and the evaluation of "B (poor)" when the sag Z was more than 0.10 times. For burrs that may cause dents or electrical shorts, those with a size of less than 0.2 mm were rated as "A (good)", and those with a size of 0.2 mm or more or those with whisker-like burrs were rated as "B (poor)". In addition, in terms of appearance and dimensional accuracy of the product, it is desired to minimize the drop of the end surface. Therefore, those with a drop of 0.5 mm or less are evaluated as "A (good)", and those with a drop of more than 0.5 mm are evaluated as "B (poor)".

In addition, the sample was subjected to an air exposure test outdoors, and the number of days until obvious red rust appeared on the cut end was observed every 15 days.

The above results are listed in Table 1. Table 1 also lists the plated steel sheets used for each sample, the conditions of the half-cutting step and the finishing step, and whether or not the corners of the cut ends are subjected to coining. Here, the plate thickness ratio (R1/t1, R2/t2) of the radius of curvature of the die is a ratio obtained by dividing the roundness given to the die shoulder by the plate thickness. Those who do not intentionally give roundness to the die shoulder (knife edge) are described as "<0.01" in this column.

As shown in Table 1, the remaining length L of plating components in Examples a1 to a19 is more than 0.70 times the thickness t1 of the cut end, and the size of the sag Z that appears in the thickness direction is less than 0.10 times the thickness t1 of the cut end of the processed product. The length W1 of the fractured surface at the cut end was all 1.0 mm or less, and Examples a1 to a19 showed good corrosion resistance in which red rust occurred after 60 days. The size of the sag X that appears in the plane direction in Examples a1 to a13 is less than 0.30 times the thickness t1 of the trimmed end of the processed product. In Examples a1 to a16 in which the length W1 of the fractured surface at the cut end was 0.5 mm or less, good corrosion resistance was exhibited in which red rust was not generated until 90 days or more passed.

In Examples a1 to a14, the remaining length L of the plating component is more than 0.80 times the thickness t1 of the cut end of the processed product, and the fracture surface length (W1) is within the range of 0.5 mm or less. In addition, in Example a15, after fine blanking, sizing processing was performed to form a sizing surface of the R surface, and the length of the side to be flattened (the width of the sizing surface) of the R surface was set to 0.6 mm. Example a16 is the person who has carried out the finishing process for forming the finishing surface of the C surface after the fine blanking, and the length of the side to be flattened (the width of the finishing surface) of the finishing surface of the C surface is set to 1.0mm and is chamfered at an angle of 45°. The length (W2) of the fracture surface after sizing is smaller than the length W1 of the fracture surface of other examples. Regarding the absolute value | _D32 - _D31 | of the difference between the die diameter _D31 of the cutting process and the die diameter _D32 of the fine cutting process, it is set to 0.05mm in the examples a1~a17, set to zero in the example a18 (the diameter _D31 is the same as the diameter _D32 ) and set to 1.00mm in the example a19.

In addition, based on the above features, it can be confirmed from the appearance that the trimmed ends of Examples a1~a14, a18, and a19 have sagging, sheared surfaces, and fractured surfaces sequentially in the thickness direction, and the trimmed ends of Examples a15, a16 have sags, sheared surfaces, fractured surfaces, and sizing surfaces sequentially in the thickness direction.

In contrast, in Comparative Examples a1-a5, a8, a10-a13, and a16, the remaining length L of the plating layer components is less than 0.70 times the thickness t1 of the cut end of the processed product, so the number of days until red rust occurs at the cut end is less than 60 days, and the corrosion resistance is worse than that of the examples. In comparative example a9, a large negative clearance was adopted in the half-cutting step, but the load was exceeded in the half-cutting process step using a 750kN mechanical press. The press stops. Comparative examples a14 and a15 both showed good corrosion resistance in which red rust was formed at the cutting end after more than 90 days, but a large burr of more than 0.2mm was generated at the cutting end.

Comparative example a6 shows good corrosion resistance with a period of more than 90 days until red rust occurs at the cutting end. However, the size of the sag Z that appears in the thickness direction is more than 0.10 times the thickness of the flange blank, and the size of the sag X that appears in the plane direction is more than 0.30 times the thickness of the processed product. When screwing, the size of the blank must be increased by this amount. In Comparative Example a7, the gap between the die and the punch in the half-cutting step was set to zero, and the plated steel sheet was completely broken in the half-cutting step.

(Example b. The case where the blades of the die and the punch used in the half-cutting step are set to an R shape)

Next, set the die and the shoulder (that is, the blade) of the punch in the half-cutting step to an R shape with a predetermined radius of curvature, and make a sample of the processed product by the method shown in FIGS. 5 and 11 . The plated steel plate is a Zn-6%Al-3%Mg (mass ratio) alloy plated steel plate with a thickness of 1.4~4.5mm and a plating weight of 90g/m ² (one side) or 190g/m ² (one side). The half-cutting process is carried out by using a circular die and a punch to hold the plated steel plate by using a platen. The circular die has an inner diameter of 85.00mm, and the diameter of the punch has been changed to match the clearance between the die and the punch. Fine cutting is carried out by using a die and a punch to hold the plated steel sheet using a platen. The shoulder (that is, the blade) of the die is R-shaped with a predetermined radius of curvature, and the diameter of the punch has been changed according to the clearance between the die and the punch.

For each sample, flatness evaluation, burr evaluation, and drop evaluation were performed in the same manner as in the above-mentioned embodiment a, and the number of days for red rust generation was investigated by an atmospheric exposure test. The result of embodiment b is listed in table 2.

As shown in Table 2, the remaining length L of plating components in Examples b1 to b19 is more than 0.70 times the thickness t1 of the trimmed end of the processed product, and the size of the sag Z that appears in the thickness direction is less than 0.10 times the thickness t1 of the trimmed end of the processed product. The fracture surface lengths of the cut ends are all below 1.0 mm, and Examples b1 to b19 show good corrosion resistance in which red rust occurs after 60 days. In Examples b1~b13, b15~b19, the size of the sagging X that appears in the plane direction is less than 0.30 times the thickness t1 of the trimmed end of the processed product. In Examples b1 to b14, b16, and b17, the remaining length L of the plating component is more than 0.80 times the thickness t1 of the cut end of the processed product, and the length of the fracture surface (W1) is within the range of 0.5mm or less, and it shows good corrosion resistance that red rust occurs after more than 90 days. In addition, in Example b16, after fine blanking, the sizing process for forming the sizing surface of the R surface was performed, and the length of the side to be flattened (the width of the sizing surface) of the R surface was set to 0.6 mm. In Example b17, after the fine blanking, the coining process for forming the coining surface of the C surface is carried out. The length of the edge to be flattened (the width of the coining surface) of the coining surface of the C surface is set to 1.0mm and chamfered at an angle of 45°. The fracture surface length (W2) after sizing became smaller than other examples. Regarding the absolute value | _D32 - _D31 | of the difference between the die diameter D ₃₁ of the semi-cutting process and the die diameter D ₃₂ of the fine-cutting process, it is set to 0.05 mm in the embodiments b1 to b17, to zero in the embodiment b18 (the diameter D ₃₁ is the same as the diameter D ₃₂ ) and to 1.00 mm in the embodiment b19.

In addition, based on the above characteristics, it can be confirmed from the appearance that the trimmed ends of Examples b1 to b15, b18, and b19 have sag, sheared surface, and fractured surface sequentially in the direction of plate thickness, and the trimmed ends of Examples b16 and b17 have sags, sheared surfaces, fractured surfaces, and stenciled surfaces sequentially in the direction of plate thickness.

In contrast, in Comparative Examples b1, b2, b4, b6-b8, b11, and b13, the residual length L of the plating layer components is less than 0.70 times the thickness t1 of the cut end of the processed product, so the days until red rust occurs at the cut end are less than 60 days, and the corrosion resistance is worse than that of the examples. In addition, in Comparative Examples b1 and b4, since the size of the sag Z appearing in the plate thickness direction is 0.10 times the plate thickness t1 of the trimmed end portion of the processed product, sufficient flatness cannot be obtained. Comparative Example b5 uses a large negative clearance in the half-cutting step, but when using The 750kN mechanical press machine stopped when the load was exceeded during the semi-punching process. Comparative examples b9 and b10 both showed good corrosion resistance in which red rust was formed at the cutting end after more than 90 days, but a large burr of more than 0.2mm was generated at the cutting end. In comparative examples b3 and b12, due to insufficient negative clearance between the die and the punch in the half-cutting step, the plated steel sheet was completely broken during the half-cutting step.

From the above, in the trimming process in which the half trimming step is performed and then the finishing trimming step is performed, regarding the shape of the trimmed edge, it was confirmed that the trimmed edge with good corrosion resistance can be obtained by setting the plating component remaining length L to 0.70 times or more relative to the plate thickness t1 of the trimmed edge of the processed product. It was also confirmed that by setting the sag Z appearing in the thickness direction of the cut end to be less than 0.10 times the thickness t1 of the cut end of the processed product, the product can be obtained without additionally increasing the size of the base material during screwing.

Above, the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited by these examples. And it is obvious that those who have general knowledge in the technical field of the present invention can think of various changes or amendments within the scope of the technical ideas recorded in the scope of the patent application, and know that these should also belong to the technical scope of the present invention.

12: Flange

13:Cut ends

13a: upper surface

13b: Collapse

13c: shear plane

13d: fracture surface

13e: Burr

13f: plating layer

L: Plating component remaining length (plating layer length)

T: Thickness direction of the flange

W1: The length of the fracture surface in the thickness direction of the flange

X: Sag size (the length of the sag in the plane direction perpendicular to the thickness direction of the flange)

Z: Sag dimension (the length of the sag in the thickness direction of the flange)

X, Z: direction

Claims (5)

A method for manufacturing a processed product, which is a method for manufacturing a processed product that uses a plated steel plate with a plated layer on its surface as a blank and has a cut end; the method includes the following steps: a half-cutting step, using a first die and a first punch to half-cut a cut portion of a first blank formed from the blank in the direction of plate thickness, and the clearance between the first die and the first punch is set to a negative clearance; and, a fine cutting step, using a second die and a second punch The head performs fine cutting on the first semi-cut body from the same direction as the half-cut to obtain a processed product with a cut end along the thickness direction;₃₂Let it be the inner diameter D of the aforementioned first die₃₁As mentioned above, when the trimming end is to be formed on the inner side of the aforementioned processed product, the outer diameter d of the aforementioned second die₃₂Let it be the outer diameter d of the aforementioned first die₃₁The following; let the plate thickness of the cut part of the aforementioned first blank body be t1 and make the remaining plate thickness of the aforementioned cut part after the aforementioned half-cutting step be t2, in the aforementioned half-cutting step, the clearance C between the aforementioned first die and the aforementioned first punch_31-41The following formula (a1) is satisfied, the radius of curvature R1 of the blade of the first die satisfies the following formula (a2), the pressing amount D of the first die or the first punch to the cut portion of the first blank body satisfies the following formula (a3), and the distance between the first die and the first punch at the bottom dead center is C_PDSatisfy the following formula (a4): In the aforementioned fine cutting step, the clearance C between the aforementioned second die and the aforementioned second punch_32-42The following formula (a5) is satisfied, and the radius of curvature R2 of the blade of the aforementioned second die satisfies the following formula (a6); -0.25×t1≦C_31-41≦-0.01‧‧‧(a1) 0.10×t1≦R1≦0.50×t1‧‧‧(a2) D≧0.70×t1‧‧‧(a3) C_PD≧0.20‧‧‧(a4) 0.01≦C_32-42≦0.2×t2‧‧‧(a5) 0.25≦R2≦1.50×t2‧‧‧(a6) Here, C_31-41、C_PD、C_32-42and the unit of R2 is mm. A method for manufacturing a processed product, which is a method for manufacturing a processed product that uses a plated steel plate with a plated layer on its surface as a blank and has a cut end; the method includes the following steps: a half-cutting step, using a first die and a first punch to half-cut a cut portion of a first blank formed from the blank in the direction of plate thickness, and the clearance between the first die and the first punch is set to a negative clearance; and, a fine cutting step, using a second die and a second punch The head cuts the half-cut first blank from the same direction as the half-cut to obtain a processed product with a cut end. The cut surface of the cut end is along the aforementioned plate thickness direction;₃₂Let it be the inner diameter D of the aforementioned first die₃₁As mentioned above, when the trimmed end is to be formed on the inner side of the processed product, the outer diameter d of the second die₃₂Let it be the outer diameter d of the aforementioned first die₃₁The following; let the plate thickness of the cut part of the aforementioned first blank body be t1 and make the remaining plate thickness of the aforementioned cut part after the aforementioned half-cutting step be t2, in the aforementioned half-cutting step, the clearance C between the aforementioned first die and the aforementioned first punch_31-41The following formula (b1) is satisfied, and the radius of curvature R11 of the blade of the aforementioned first die satisfies the following formula (b2-1), The radius of curvature R12 of the blade of the aforementioned first punch satisfies the following formula (b2-2), the pressing amount D of the aforementioned first die or the aforementioned first punch to the cutting portion of the aforementioned first blank body satisfies the following formula (b3), and the distance between the aforementioned first die and the aforementioned first punch at the bottom dead center is C_PDSatisfy the following formula (b4); in the aforementioned fine cutting step, the clearance C between the aforementioned second die and the aforementioned second punch_32-42The following formula (b5) is satisfied, and the radius of curvature R2 of the blade of the second die satisfies the following formula (b6); -0.35×t1≦C_31-41≦-0.10×t1‧‧‧(b1) 0.10×t1≦R11≦0.65×t1‧‧‧(b2-1) 0.10×t1≦R12≦0.65×t1‧‧‧(b2-2) D≧0.70×t1‧‧‧(b3) C_PD≧0.20‧‧‧(b4) 0.01≦C_32-42≦0.2×t2‧‧‧(b5) 0.25≦R2≦1.50×t2‧‧‧(b6) here, C_31-41、C_PD、C_32-42and the unit of R2 is mm. The method for manufacturing a processed product according to claim 1 or 2, further comprising a finishing step, wherein the processed product obtained in the fine cutting step is used as a second blank, and the corners of the cut ends of the second blank are pressed against the pad to obtain a processed product with a fine-pressed surface formed at the corner. The method of manufacturing _{a processed} product according to claim 1 or 2, wherein when forming a _{cut end on the outer peripheral side of the processed product, the absolute value |D 32 −D 31 | 32} -d ₃₁ | Set it below 1.00mm. The method for manufacturing processed products as claimed in claim 1 or 2, wherein in the aforementioned half-cutting step The preceding step further includes a preparatory step of forming the first green body from a plate-shaped plated steel sheet.