Method for manufacturing a press-formed product and press-forming device

Abstract

A saddle-shaped press-formed product is formed using a simpler mold structure. The press-formed product (1) has a top plate portion (1A), a vertical wall portion (1C) that is continuous with the width direction of the top plate portion (1A) via a convex ridge portion (1B), and an outward flange portion (1E) that is continuous with the length direction end of the top plate portion (1A), the length direction end of the convex ridge portion (1B), and the length direction end of the vertical wall portion (1C) via a concave ridge portion (1D). When the press-formed product (1) is manufactured using a metal plate (2), the metal plate (2) is bent at the position of the convex ridge portion (1B) to form a cross-sectional L-shaped form in a state in which the region that becomes the outward flange portion (1E) is released, and then the outward flange portion (1E) is formed by bending at the position of the concave ridge portion (1D).

Description

Technical Field

[0001] This invention relates to a technique for manufacturing saddle-shaped stamped articles by stamping metal sheets using a die.

[0002] The saddle-shaped stamped product includes: a top plate portion; a longitudinal wall portion that is continuous with the top plate portion in the width direction via a convex ridge portion; and an outwardly projecting flange portion that is continuous with the end of the top plate portion, the end of the convex ridge portion, and the end of the longitudinal wall portion in the long side direction via a concave ridge portion. Background Technology

[0003] In industries such as automobiles and home appliances, most stamped parts are manufactured by deforming flat metal sheets into various shapes. Stamping (forming) is widely used in the mass production of stamped parts. Stamping is a processing method that uses a stamping press and dies assembled on the press to deform a metal sheet. Typically, the metal sheet before processing is flat. Therefore, in order to deform the metal sheet into a complex three-dimensional shape, the metal sheet must be stretched to match the desired three-dimensional shape.

[0004] However, the more complex the shape of the stamped part, the more difficult it is to provide the metal sheet with the required stretching and contraction to match the three-dimensional shape. In particular, the above difficulties are likely to occur when the metal sheet is made of high-strength steel sheet or aluminum alloy sheet with a tensile strength of 590 MPa or more and has poor ductility and Lankforod value, which are difficult to form.

[0005] During stamping, if the metal sheet cannot be stretched to match the three-dimensional shape, forming defects such as cracking and wrinkling can occur. Specifically, when deforming the metal sheet into a three-dimensional shape, in areas where the sheet's length is insufficient and cannot be compensated for by surrounding material, the sheet must elongate. Furthermore, if the sheet is stretched beyond its ductility, cracking will occur. On the other hand, if the sheet's length must shrink during deformation into a three-dimensional shape, or in areas where there is excessive flow from the surrounding material, wrinkling is likely to occur.

[0006] As an example of a part shape that is difficult to stamp, there is a saddle-shaped stamped part. The saddle-shaped stamped part has an outwardly projecting flange that extends continuously across a top plate and longitudinal walls formed on both sides of the top plate. The outwardly projecting flange is the flange at the end in the long side direction. When forming such a complex part shape from a flat sheet of metal, tensile and compressive deformations occur during the forming process. Therefore, the sheet metal is prone to cracking and wrinkling.

[0007] When stamping articles with complex shapes as described above using sheet metal, for example, bending processes are performed using a die consisting of a punch, a die, and a backing plate. In this case, due to insufficient line length during forming, there is a concern that the flange at the end in the long side direction may crack, resulting in poor forming.

[0008] As a countermeasure to this problem, for example, there is a method for manufacturing a saddle-shaped stamped article as described in Patent Document 1. In Patent Document 1, when manufacturing the saddle-shaped stamped article, the top plate component is bent, and during this bending, a first force is applied to the top plate component from the inner surface side toward the outer surface side. In addition, Patent Document 1 describes applying a resultant force of a second force in an opposing direction and a third force opposite to the first force to the outer surface side of the longitudinal wall component.

[0009] Patent Document 1: International Publication No. 2019 / 216317

[0010] The manufacturing method described in Patent Document 1 has the problem that the mold becomes more complex and the cost of the mold increases.

[0011] Here, when manufacturing a stamped product having a continuous outwardly projecting flange spanning the top plate and the longitudinal wall, the following problem exists when simply stamping a sheet metal: The corner portion (corner) of the outwardly projecting flange, connecting the top plate and the longitudinal wall, is subjected to tensile deformation. Furthermore, strain concentrates in this portion, raising concerns about cracking at the corner. Therefore, conventionally, it has been impossible to widen the flange width of the corner portion of the outwardly projecting flange, that is, the portion continuous with the long side end of the convex ridge portion. Therefore, it is necessary to cut the flange width of the ridge portion to a formable width (see reference). Figure 17 The attached figure is labeled 1Ec (where the cut is located).

[0012] In Patent Document 1, a vertically movable pad is added to the center of the top plate portion of the lower mold, and forming is performed with the pad protruding. This disperses the strain of the outwardly projecting flange portion at the long side end of the metal sheet, which bends the top plate component, towards the top plate portion. However, Patent Document 1 requires a mechanism to add the protruding pad to the lower mold. Therefore, the mold becomes more complex, and the cost increases. Furthermore, the movement of the pad in the lower mold needs to be controlled, resulting in poor productivity. Summary of the Invention

[0013] The present invention was made with regard to the points mentioned above, and its purpose is to form a saddle-shaped stamped article using a simpler mold structure. The saddle-shaped stamped article has a top plate portion, a longitudinal wall portion, and an outwardly projecting flange portion formed at the long side end of the top plate portion and the longitudinal wall portion.

[0014] The inventors have conducted various studies on stamping methods for saddle-shaped stamped articles having a top plate, left and right longitudinal walls, and an outwardly projecting flange extending across the long side of the top plate and longitudinal walls. Specifically, they have conducted various studies on stamping methods that can form without cracking and do not require complex die structures. The results of these studies have yielded the following insights (1) and (2).

[0015] (1) After the metal sheet is shaped into a U-shaped section, when the outward flange is bent, the forming of the flange begins from the top plate and the longitudinal wall. As a result, the strain of the outward flange located at the end in the long side direction can be dispersed to the top plate side and the longitudinal wall side.

[0016] (2) By changing the shape of the punch (the shape of the lower die) that forms the outward flange, the strain distribution in the outward flange can be controlled.

[0017] This invention was made based on the following insights.

[0018] To address the problem, one aspect of the present invention is characterized by providing a stamped article comprising: a top plate portion; a longitudinal wall portion that is continuous in the width direction of the top plate portion via a convex ridge portion; and an outward flange portion that is continuous in the long side direction end of the top plate portion, the long side direction end of the convex ridge portion, and the long side direction end of the longitudinal wall portion via a concave ridge portion. When manufacturing the stamped article from a sheet metal, with the region forming the outward flange portion released, the sheet metal is bent at the position of the convex ridge portion to form an L-shaped cross-section, and then bent at the position of the concave ridge portion to form the outward flange portion.

[0019] Furthermore, another aspect of the present invention is characterized by providing a stamped article comprising: a top plate portion; a longitudinal wall portion that is continuous in the width direction of the top plate portion via a convex ridge portion; and an outwardly projecting flange portion that is continuous in the long-side direction end of the top plate portion, the long-side direction end of the convex ridge portion, and the long-side direction end of the longitudinal wall portion via a concave ridge portion. When manufacturing the stamped article from a sheet metal, the sheet metal is bent at the position of the convex ridge portion to form an L-shaped cross-section, and bent at the position of the concave ridge portion to form the outwardly projecting flange portion. When the outward flange portion is formed by bending at the position of the concave ridge portion, bending force is applied to the region in the area that forms the outward flange portion, which is continuous with the long side end of the top plate portion and the long side end of the longitudinal wall portion. Then, bending force is applied to the region that is continuous with the long side end of the concave ridge portion and the convex ridge portion. After the L-shaped cross-section is formed, the forming of the region in the outward flange portion that is continuous with the long side end of the concave ridge portion and the convex ridge portion is completed.

[0020] Furthermore, another aspect of the present invention is characterized by providing a stamping forming apparatus for manufacturing stamped articles from sheet metal, the stamped articles comprising: a top plate portion; a longitudinal wall portion that is continuous in the width direction of the top plate portion via a convex ridge portion; and an outwardly projecting flange portion that is continuous in the long-side direction end of the top plate portion, the long-side direction end of the convex ridge portion, and the long-side direction end of the longitudinal wall portion via a concave ridge portion, wherein the stamping forming apparatus comprises: a first upper die and a first lower die, which have forming surfaces capable of forming the regions of the top plate portion and the longitudinal wall portion at the positions where the convex ridge portion is formed, and for the top plate portion and the longitudinal wall portion... The longitudinal wall portion, which is continuous with the top plate portion, is formed; and the second lower mold, which bends the metal plate at the concave ridge portion to form the outward flange portion, wherein the forming surface of the portion of the second lower mold that inputs bending force into the region of the outward flange portion to form the outward flange portion has a top and a pair of inclined surfaces continuous on the left and right sides of the top when viewed from the long side direction of the top plate portion, and the whole is a mountain-shaped shape protruding in the bending direction of the outward flange portion, wherein the top of the mountain-shaped shape is set to be able to abut against the region of the region of the outward flange portion that is continuous with the end of the long side direction of the top plate portion via the concave ridge portion.

[0021] According to the method of the present invention, a saddle-shaped stamped article can be formed using a simpler mold structure. The saddle-shaped stamped article has a top plate portion, a longitudinal wall portion, and an outwardly projecting flange portion formed across the long side end of the top plate portion and the longitudinal wall portion.

[0022] For example, according to the method of the present invention, without a complex mold structure, the strain of the outward flange portion in a stamped article having a top plate portion, longitudinal wall portions formed on both sides of the top plate portion, and a continuous outward flange portion (flange portion at the end in the long side direction) spanning the top plate portion and the longitudinal wall portions can be dispersed. As a result, a saddle-shaped stamped article with an enlarged flange width of the ridge portion can be formed using a simple mold structure. Attached Figure Description

[0023] Figure 1 This is a perspective view showing an example of a stamped article based on an embodiment of the present invention.

[0024] Figure 2 Viewed from the long side of the top plate Figure 1 The front view obtained from the stamping of the product.

[0025] Figure 3 This is a schematic perspective view showing an example of the structure of a die used in a stamping apparatus based on an embodiment of the present invention.

[0026] Figure 4 This diagram shows the state in which the first lower die has moved upwards.

[0027] Figure 5 This diagram illustrates the function of the mountain-shaped form of the second lower mold.

[0028] Figure 6 It is a schematic three-dimensional diagram showing the state of stamping formed using the first upper die and the first lower die.

[0029] Figure 7 This diagram shows the state in which the second lower die has made a downward stroke in order to perform the first process.

[0030] Figure 8 It is a schematic perspective view showing the shape of the molded article after performing a portion of the first molding process and the second molding process in the first step.

[0031] Figure 9 This is a diagram illustrating an example of the contour shape of the mountain-shaped ramp in the second lower mold, wherein... Figure 9 (a) is the case of a straight line shape. Figure 9 (b) is the case of a curved shape with an upward convex bend. Figure 9 (c) is the case of a convex, bent curve.

[0032] Figure 10 This is a diagram showing a variation of the top of a mountain-shaped structure.

[0033] Figure 11This is a diagram showing the distribution of the plate thickness reduction rate along the width direction of the top plate portion in the inventive examples and comparative examples based on the embodiments.

[0034] Figure 12 It is a diagram showing the distribution of the plate thickness reduction rate along the width direction of the top plate under multiple punch angles.

[0035] Figure 13 This is a graph showing the relationship between the punch angle and the reduction rate of plate thickness.

[0036] Figure 14 This is a graph showing the relationship between the stroke of the second lower die and the reduction rate of plate thickness.

[0037] Figure 15 This is a graph showing the relationship between the punch angle and the reduction rate of plate thickness.

[0038] Figure 16 This is a graph showing the relationship between the slope shape of the second lower die and the plate thickness reduction rate.

[0039] Figure 17 This is a perspective view showing other examples of stamped products. Detailed Implementation

[0040] Next, embodiments of the present invention will be described with reference to the accompanying drawings.

[0041] Here, the accompanying drawings are schematic diagrams, and the relationship between the thickness and planar dimensions of each component, as well as the ratios of each component, differ from reality. Furthermore, the embodiments shown below illustrate structures used to embody the technical concept of this disclosure; the technical concept of this disclosure does not specify the shape or structure of the constituent components as described below. The technical concept of this disclosure can be modified in various ways within the scope of the technology defined by the claims. Additionally, the same reference numerals are used to denote the same structures.

[0042] "Stamped Part 1"

[0043] In the embodiments described below, to manufacture Figure 1 The following explanation will be based on the case of a saddle-shaped stamped product 1 as shown.

[0044] Figure 1 The stamped product 1 shown includes a top plate portion 1A, left and right longitudinal wall portions 1C that are continuous on both sides of the top plate portion 1A in the width direction via left and right convex ridge portions 1B, and an outward flange portion 1E. The outward flange portion 1E is continuous with the long side end of the top plate portion 1A, the long side end of the convex ridge portion 1B, and the long side end of the left and right longitudinal wall portions 1C via concave ridge portions 1D.

[0045] also, Figure 1The stamped product 1 shown has a lower flange 1F that is continuous with the lower end of the longitudinal wall portion 1C. The saddle-shaped stamped product may also lack this lower flange 1F.

[0046] In addition, Figure 1 In the shape shown, the top plate portion 1A has longitudinal wall portions 1C on both sides in the width direction, forming a U-shaped cross-section. However, the shape of the stamped product 1 can also be a stamped part shape with a longitudinal wall portion 1C on only one side in the width direction of the top plate portion 1A, forming an L-shaped cross-section. Even with such a stamped product 1, the present invention can be applied. Here, both the U-shaped and L-shaped cross-sections also include the cross-sectional shape with a flange at the lower end of the longitudinal wall portion 1C.

[0047] In addition, Figure 1 The example shown illustrates a case where outwardly projecting flanges 1E are formed at both ends along the long side. The saddle-shaped stamped product 1 may also have a structure where the outwardly projecting flange 1E is only present at one end along the long side.

[0048] The outwardly projecting flange 1E is formed as a single flange that is continuous with the long-side end of the top plate portion 1A, the long-side end of the convex ridge portion 1B, and the long-side ends of the left and right longitudinal wall portions 1C, and spans across the width direction of the top plate portion 1A. That is, as shown... Figure 2 As shown, the outwardly projecting flange portion 1E includes a top plate side region 1Ea (a region continuous with the long side end of the top plate portion 1A), left and right longitudinal wall side regions 1Eb (regions continuous with the long side end of the longitudinal wall portion 1C), and left and right ridge side regions 1Ec (regions continuous with the long side end of the convex ridge portion 1B) connecting the top plate side region 1Ea and the longitudinal wall side region 1Eb.

[0049] In the following description, the region that becomes the outwardly projecting flange 1E in the metal sheet (blank) and is designated as the top plate side region 1Ea is sometimes referred to as the top plate side component, the region that becomes the longitudinal wall side region 1Eb is referred to as the longitudinal wall side component, and the region that becomes the edge side region 1Ec is referred to as the corner component. Furthermore, the same reference numerals are used for the top plate side region 1Ea and the top plate side component. The same reference numerals are used for the longitudinal wall side region 1Eb and the longitudinal wall side component. The same reference numerals are used for the edge side region 1Ec and the corner component.

[0050] "First Implementation"

[0051] The first embodiment based on the present invention will be described with reference to the accompanying drawings.

[0052] (Manufacturing method of stamped parts)

[0053] First, the manufacturing method of the stamped product according to this embodiment will be described.

[0054] The method for manufacturing stamped articles according to this embodiment includes a first step and a second step.

[0055] <Step 1>

[0056] The first process is to form a metal sheet (blank) into a U-shaped cross section by shaping the metal sheet (blank) at the left and right convex ridge portions 1B. Furthermore, in the first process, if we focus on the longitudinal wall portion 1C on one side of the width direction of the top plate portion 1A, it is synonymous with the process of bending the metal sheet at the convex ridge portion 1B to form an L-shaped cross section.

[0057] In addition, as a stamping method, this embodiment illustrates a simple forming process using an upper and lower die clamping. The stamping method can also be a backing plate forming process using a backing plate, or a drawing forming process using a pressure ring.

[0058] In the first step, it is preferable to perform stamping forming on the area that becomes the top plate portion 1A and the area that becomes the longitudinal wall portion 1C while the area that becomes the outward flange portion 1E is free, thereby forming the metal sheet into a U-shaped cross section (L-shaped cross section). The aforementioned "freed state" means that the area that becomes the outward flange portion 1E is not constrained. That is, the forming of the first step is performed while the area that becomes the outward flange portion 1E is free. As a result, it is easy to perform the second step consecutively with the first step.

[0059] <Second Process>

[0060] The second process is to bend the metal plate, which has been shaped into a cross-section of a コ (ko) in the first process, at the concave ridge section 1D to form an outwardly protruding flange section 1E.

[0061] In the second step, bending is performed at the concave ridge portion 1D to form an outwardly projecting flange portion 1E. Preferably, bending force is first applied to the top plate side component 1Ea and the longitudinal wall side component 1Eb in the region forming the outwardly projecting flange portion 1E, and then to the corner component 1Ec. The top plate side component 1Ea is a portion that is continuous with the long side end of the top plate portion 1A via the concave ridge portion 1D. The longitudinal wall side component 1Eb is a portion that is continuous with the long side end of the longitudinal wall portion 1C via the concave ridge portion 1D. The corner component 1Ec is a portion that is continuous with the long side end of the convex ridge portion 1B via the concave ridge portion 1D.

[0062] For example, for the longitudinal wall side component 1Eb, it is set to input bending force sequentially from the lower side position away from the corner component 1Ec toward the corner component 1Ec. Then, it is set to input bending force to the longitudinal wall side component 1Eb first, and then input bending force to the top plate side component 1Ea.

[0063] The input of bending force to the top plate side component 1Ea is set as follows: Specifically, the input of bending force is set to begin from the center of the top plate portion 1A in the width direction within the top plate side component 1Ea, and then sequentially input towards the corner component 1Ec. The starting position of the input of bending force to the top plate side component 1Ea is acceptable as long as it is midway along the width direction of the top plate portion 1A within the top plate side component 1Ea. The starting position of the input of bending force to the top plate side component 1Ea is 0 mm or more away from the end of the corner component 1Ec, preferably 3 mm or more. Here, through experiments, it has been confirmed that compared to simultaneously inputting bending force to both the top plate side component 1Ea and the corner component 1Ec, setting the starting position of the input of bending force based on the top 12A of the second lower die 12 to a position 0 mm or more away from the end of the corner component 1Ec during stamping improves the thickness reduction rate in the corner component 1Ec. In particular, by separating the corner component 1Ec by more than 3mm, it is possible to more reliably set the input start position of the bending force based on the top 12A of the second lower die 12 to be inside the corner component 1Ec.

[0064] Furthermore, the end of the corner component 1Ec refers to the boundary between the arc-shaped corner component 1Ec and the top plate side component 1Ea or the longitudinal wall side component 1Eb.

[0065] Furthermore, it is preferable to perform the process of forming the outwardly projecting flange 1E while the metal sheet is constrained into a formed cross-sectional U-shape (cross-sectional L-shape). In this case, the first and second processes can be performed continuously in a single stamping operation.

[0066] Here, the angle of the L-shaped profile after the first process can be different from the angle of the L-shaped profile in the stamped part 1 of the desired saddle shape. However, it is preferable that the two angles are equal. By forming the outward flange portion 1E after the first process, the springback of the longitudinal wall portion 1C relative to the top plate portion 1A can be suppressed. As a result, the direction of shape change during demolding can be suppressed.

[0067] The first and second processes can also be performed using different molds.

[0068] In addition, after the second process, there may be a fine pressing process to improve the accuracy of the shape and size.

[0069] Here, the second process can also begin midway through the first process.

[0070] (Stamping forming device)

[0071] Next, an example of a stamping forming apparatus for performing a method for manufacturing the shape of a stamped part in this embodiment will be described.

[0072] As a die for stamping, this embodiment includes a first upper die and a first lower die 11, and a second upper die and a second lower die 12.

[0073] In this embodiment, for a stamping forming apparatus, such as Figure 3 As shown, an example is illustrated where the first upper die and the second upper die are both composed of a single upper die 10 (punch die). Furthermore, the first lower die 11 and the second lower die 12 are configured to be offset along the long side of the top plate portion 1A. With this configuration, the first stamping process and the second stamping process can be performed in a single stamping operation.

[0074] Alternatively, the first upper die 10 and the first lower die 11, and the second upper die and the second lower die 12 can be independent die structures. Alternatively, the first upper die 10 and the first lower die 11, and the second upper die and the second lower die 12 can be separately set on a stamping machine to perform stamping processing.

[0075] <1st upper mold 10 and 1st lower mold 11>

[0076] The first upper mold 10 and the first lower mold 11 are molds used to perform the first process.

[0077] The first upper die 10 and the first lower die 11 have forming surfaces capable of forming the areas of the metal plate 2 that become the top plate portion 1A and the longitudinal wall portion 1C at the position that becomes the convex ridge portion 1B. The first upper die 10 and the first lower die 11 are molds used to form the metal plate 2 into a U-shaped cross section.

[0078] The first lower die 11 constitutes the punch. (The following is a description of the forming surface of the die.) Figure 3 As shown, the first lower die 11 is configured such that the forming surface has a U-shaped cross section. The first lower die 11 has a first top plate surface 11A that abuts against the lower surface of the area that forms the top plate portion 1A in the metal plate 2, a punch shoulder portion 11C that abuts against the lower surface of the area that forms the convex ridge portion 1B, left and right first side surfaces 11B that abut against the lower surface (inner surface) of the area that forms the longitudinal wall portion 1C, and left and right first flange surfaces 11D that abut against the lower surface of the area that forms the lower flange portion.

[0079] The first upper die 10 constitutes a stamping die, and is positioned vertically (in the stamping direction) opposite the first lower die 11. For example... Figure 3As shown, the first upper die 10 is configured such that the forming surface has a U-shaped cross section. Specifically, the first upper die 10 has a second top plate surface 10A that abuts against the upper surface of the region that forms the top plate portion 1A in the metal plate 2, a die shoulder portion 10C that abuts against the upper surface of the region that forms the convex ridge portion 1B, left and right second side surfaces 10B that abut against the upper surface (outer surface) of the region that forms the longitudinal wall portion 1C, and left and right second flange surfaces 10D that abut against the upper surface of the region that forms the lower flange portion.

[0080] Moreover, as from Figure 3 Position towards Figure 4 As the position changes, the stamping device becomes a structure in which the first lower die 11 moves relative to the first upper die 10. Thus, as... Figure 6 As shown, the metal plate 2 is clamped by the first lower mold 11 and the first upper mold 10. As a result, the metal plate 2 is bent at the convex ridge portion 1B and formed into a U-shaped cross section.

[0081] At this time, in this embodiment, such as Figure 6 As shown, the forming surfaces of the first lower mold 11 and the first upper mold 10 do not abut against the region that forms the outward flange portion 1E. However, the region that forms the outward flange portion 1E has a U-shaped cross-section, similar to the top plate portion 1A and the longitudinal wall portion 1C.

[0082] <The second upper mold and the second lower mold 12>

[0083] The second upper mold and the second lower mold 12 are molds used to perform the second process.

[0084] The second upper mold and the second lower mold 12 are molds used to bend the metal plate 2, which is formed into a cross-sectional shape (cross-sectional L-shape) by the first upper mold and the first lower mold 11, in the concave ridge section 1D to form the outwardly protruding flange section 1E.

[0085] Furthermore, in this embodiment, as described above, the first upper mold and the second upper mold constitute one upper mold 10.

[0086] like Figure 3 , Figure 6 Thus, the second upper mold has a forming surface 10E that can abut against the upper surface of the bent outward flange portion 1E. This forming surface 10E is composed of upright surfaces that rise upward from the ends of the long side of the first upper mold 10.

[0087] In addition, such as Figure 3 , Figure 6 As shown, the second lower die 12 is disposed in the press in a state where it is offset relative to the first lower die 11 in the long side direction of the top plate portion 1A.

[0088] In this embodiment, the forming surface of the portion forming the outwardly projecting flange portion by inputting bending force into the region of the second lower mold 12 is viewed from the long side direction of the top plate portion 1A, as follows: Figure 3 and Figure 4 As shown, it has a top 12A and a pair of inclined surfaces 12B that are continuous on the left and right sides of the top 12A. Thus, the forming surface becomes a mountain-shaped shape that protrudes from the top 12A as the apex in the bending direction (stamping direction) of the outward flange portion 1E.

[0089] The top 12A of the mountain-shaped structure is designed to first abut against the side component 1Ea of the top plate (see reference). Figure 5 , Figure 6 The top 12A of the preferred mountain shape is positioned to abut against the central portion of the top plate portion 1Ea in the width direction of the top plate portion 1A.

[0090] like Figure 5 As shown, the mountain shape is formed by the width of the top 12A (in Figure 5 The arc-shaped portion in the middle is smaller than the width of the top plate portion 1A (the length of the side component portion 1Ea of the top plate portion).

[0091] In addition, such as Figure 5 As shown, the punch angle α, formed by the intersection angle of the extensions of the left and right inclined planes 12B forming the mountain shape, is twice as wide as the angle obtained by subtracting 90 degrees from the angle formed by the top plate portion 1A and the longitudinal wall portion 1C in the L-shaped cross-section metal plate 2. The intersection angle β, formed by twice the angle obtained by subtracting 90 degrees from the angle formed by the top plate portion 1A and the longitudinal wall portion 1C, and the left and right longitudinal wall portions 1C (refer to...) Figure 2 They are equal. The cross angle β is the angle on the top plate side 1A. That is, as... Figure 5 As shown, the punch angle α is set to be greater than the intersection angle β formed by the extensions of the left and right longitudinal wall sections 1C (refer to...). Figure 2 That is, the inclination of the inclined surface 12B is set to be greater than the inclination of the longitudinal wall portion 1C to be formed (aggregated).

[0092] The punch angle α is, for example, between 60 and 180 degrees, preferably between 80 and 140 degrees. Here, the cross angle β is, for example, less than 40 degrees. The angle between the top plate portion 1A and the longitudinal wall portion 1C is the angle on the inner surface side.

[0093] If set as above, then as Figure 5 As shown, the second lower mold 12 is configured with left and right inclined surfaces 12B that first abut against the longitudinal wall side component 1Eb from its lower end side to its upper end side (corner component 1Ec portion) in sequence, thereby enabling the input of bending force in sequence. That is, it can be set to form the longitudinal wall side component 1Eb from the lower side to the upper side through the left and right inclined surfaces 12B.

[0094] In addition, such as Figure 5 As shown, bending force is initially applied to the longitudinal wall side component 1Eb via the mountain-shaped slope 12B. Then, bending force is initially applied to the top plate side component 1Ea via the mountain-shaped top 12A. Specifically, first, bending force is applied to the portion of the top plate side component 1Ea that is continuous with the central portion in the width direction of the top plate portion 1A via the top 12A. Next, bending force is sequentially applied towards the corner component 1Ec. That is, forming begins from the central portion of the top plate side component 1Ea towards the end portion.

[0095] Furthermore, when the length (height) of the longitudinal wall side component 1Eb is shorter, there is also a situation where the top plate side component 1Ea is formed first.

[0096] Furthermore, after the forming of the longitudinal wall side component 1Eb and the top plate side component 1Ea begins, the forming of the outward flange 1E begins with the input of bending force to the corner component 1Ec.

[0097] The input of bending force to the corner component 1Ec can begin at a time that is staggered from the input from the longitudinal wall side component 1Eb and the input from the top plate side component 1Ea, or it can begin simultaneously. It is preferable that the inputs of both begin simultaneously. If the strain is input evenly to the longitudinal wall side component 1Eb and the top plate side component 1Ea, then the input from the longitudinal wall side component 1Eb and the input from the top plate side component 1Ea begin simultaneously.

[0098] When using the above-described stamping apparatus to manufacture the stamped product 1, for example, the first upper die 10 and the first lower die 11 stamp the areas of the metal sheet 2 that become the top plate portion 1A and the longitudinal wall portion 1C into a U-shaped cross section. Then, the second upper die and the second lower die form an outwardly protruding flange portion 1E on the metal sheet 2 that has been stamped into a U-shaped cross section.

[0099] In this embodiment, while the metal plate 2 is constrained into a cross-sectional U-shape (cross-sectional L-shape) by the first upper mold 10 and the first lower mold 11, an outwardly protruding flange 1E is formed by the second upper mold and the second lower mold.

[0100] Furthermore, the formation of the outward flange 1E can also be initiated midway through the stamping process of the cross-sectional コ-shaped part.

[0101] (Other actions)

[0102] In this embodiment, as the first step, the area of ​​the metal plate 2 that becomes the top plate portion 1A and the longitudinal wall portion 1C is clamped by the first upper mold 10 and the first lower mold 11, thereby forming the metal plate 2 into a cross-sectional U-shape (cross-sectional L-shape).

[0103] In this formed state, such as Figure 6 As shown, the region that becomes the outwardly projecting flange 1E extends laterally from the first upper die 10 and the first lower die 11 (in... Figure 6 (The middle section is on the left side) extends out in a cantilever beam shape.

[0104] In this embodiment, the second process is performed while the metal plate 2 is constrained by the first upper mold 10 and the first lower mold 11. That is, the first lower mold 11 is used as a lower liner in the second process to constrain the positions of the top plate portion 1A and the longitudinal wall portion 1C in the metal plate 2.

[0105] In this state, since the metal plate 2 is clamped by the first upper mold 10 and the first lower mold 11, the metal plate 2 becomes difficult to move in both the width direction of the top plate portion 1A and the height direction of the longitudinal wall portion 1C. In this embodiment, the second process is performed in this state to form the outwardly projecting flange portion 1E.

[0106] At the start of the second process, the protruding, mountain-shaped second lower die 12 is raised (approaching the second upper die). Consequently, the inclined surface 12B of the second lower die 12 abuts against the longitudinal wall side component 1Eb from the lower end side upwards. Therefore, a bending force is applied from the lower side to the upper side to the region of the outwardly projecting flange 1E, which is continuous with the longitudinal wall 1C, and this region is held between the surface 12C of the second lower die 12 and the surface 10E of the upper die 10. As a result, the longitudinal wall side region 1Eb of the outwardly projecting flange 1E is formed by bending from the lower side upwards at the concave ridge portion 1D (see reference). Figure 5 ).

[0107] At this time, the longitudinal wall side region 1Eb is formed sequentially from the lower side (lower end) to the upper side, but the amount formed is small. In addition, the concave ridge portion 1D at this position extends in a straight line or near-straight line along the moving direction of the second lower die 12. Therefore, it is possible to achieve a state where the strain input into the longitudinal wall side region 1Eb through this forming is also small.

[0108] Midway through forming the side region 1Eb of the longitudinal wall, such as Figure 5As shown, the top 12A of the mountain-shaped structure of the second lower mold 12 contacts the portion of the top plate side component 1Ea that is continuous with the central portion of the top plate portion 1A in the width direction. This initiates the input of bending force to the top plate side component 1Ea. Alternatively, the bending force can be initiated to the top plate side component 1Ea before the longitudinal wall side region 1Eb.

[0109] At this time, taking the portion of the top plate side component 1Ea that is continuous with the central portion of the top plate portion 1A in the width direction as the center, the top plate side component 1Ea is lifted upward. As a result, strain occurs in the portion of the top plate side component 1Ea that is continuous with the central portion of the top plate portion 1A in the width direction.

[0110] Furthermore, if the forming of the longitudinal wall side region 1Eb from the lower side approaches the corner component 1Ec, it becomes a state in which the relatively rigid part is forcibly bent. Therefore, the shoulder edge (the corner extending along the mountain shape) of the second lower mold 12 is straightened and strain is generated.

[0111] In addition, as the second lower mold 12 rises, it develops towards the corner forming part 1Ec while forming the longitudinal wall side region 1Eb and the top plate side region 1Ea, and strain is generated evenly in the longitudinal wall side region 1Eb and the top plate side region 1Ea.

[0112] Next, the second lower die 12 rises, and before the corner component 1Ec is fully bent up, the curved ridge at the concave ridge portion 1D is nearly straight. As a result, even when the corner component 1Ec is bent up, the reduction rate of plate thickness at the corner component 1Ec can be suppressed to a small extent.

[0113] In this embodiment, the outward flange portion 1E is formed according to the mechanism described above.

[0114] As a result, in this embodiment, the strain of the input outward flange portion 1E is dispersed. In particular, the strain of the edge-side region 1Ec can be dispersed to the longitudinal wall-side region 1Eb and the top plate-side region 1Ea. Therefore, the concentration of strain in the edge-side region 1Ec can be suppressed, thereby improving the plate thickness reduction rate at the edge-side region 1Ec. As a result, it is possible to manufacture a flange with a wider flange width in the edge-side region 1Ec (corner portion) of the outward flange portion 1E. Figure 1 , Figure 2 The stamped product 1 shown.

[0115] As described above, according to this embodiment, a saddle-shaped stamped product having a top plate portion, a longitudinal wall portion, and an outwardly projecting flange portion formed across the long side end of the top plate portion and the longitudinal wall portion can be formed with a simpler mold structure.

[0116] "Second Implementation"

[0117] Next, a second embodiment based on the present invention will be described with reference to the accompanying drawings.

[0118] Furthermore, the same reference numerals are used to describe structures that are the same as those in the first embodiment.

[0119] (Manufacturing method for stamped parts)

[0120] The manufacturing method of the stamped part shape according to this embodiment will be described.

[0121] As a stamping process, the method for manufacturing the shape of the stamped part in this embodiment includes a first forming process and a second forming process as shown below.

[0122] The difference between this embodiment and the first embodiment is that the first molding process is performed simultaneously with the second molding process. That is, the first molding process and the second molding process are performed concurrently. However, either the first molding process or the second molding process can start first, but it is configured such that the first molding process ends first.

[0123] <First Molding Process>

[0124] The first forming process involves shaping the metal sheet (blank) into a U-shaped cross-section by forming the convex ridge portions 1B on the left and right sides. Furthermore, in the first forming process, if we consider the longitudinal wall portion 1C on one side of the width direction of the top plate portion 1A, it is synonymous with the process of bending the sheet at the convex ridge portion 1B to form an L-shaped cross-section. Additionally, as a stamping method, in this embodiment (the manufacturing method described later), a simple forming process using an upper and lower die clamping is illustrated. Other methods include plate forming using a backing plate or drawing forming using a pressure ring.

[0125] In the first forming process, with the region that becomes the outward flange portion 1E released, stamping is performed on the region that becomes the top plate portion 1A and the region that becomes the longitudinal wall portion 1C to form the metal sheet into a U-shaped (L-shaped) profile. That is, the forming of the first forming process is performed in a free state in the region that becomes the outward flange portion 1E, thereby making it easy to perform the second forming process together with the first forming process.

[0126] This first forming process corresponds to the first step in the first embodiment.

[0127] <Second forming process>

[0128] The second forming process involves bending the metal sheet, which was formed into a U-shape in the first forming process, at the concave ridge portion 1D to form an outwardly protruding flange portion 1E.

[0129] In this embodiment, the second forming process is performed simultaneously with the first forming process. The second forming process involves forming the area that was not stamped in the first forming process, that is, the free area that became the outward flange portion 1E, into the outward flange portion 1E. Furthermore, as described above, the second forming process may begin before the first forming process but end after the second forming process.

[0130] The second forming process is the same as the second step in the first embodiment, except that it is performed at the same time as the first forming process.

[0131] In the second forming process of this embodiment, the same as the second step of the first embodiment, bending force is applied to the top plate side component 1Ea and the longitudinal wall side component 1Eb in the region that forms the outward flange portion 1E. Then, bending force is applied to the corner component 1Ec, which is continuous along the long side of the concave ridge portion 1D and the convex ridge portion 1B. As a result, the outward flange portion 1E is formed by the second forming process.

[0132] For example, for the longitudinal wall side component 1Eb, it is set to start applying bending force sequentially (continuously) towards the corner component 1Ec from a position away from the corner component 1Ec. For example, it is set to start applying bending force to the top plate side component 1Ea after applying bending force to the longitudinal wall side component 1Eb.

[0133] The input of bending force to the top plate side component 1Ea is set, for example, to begin sequentially from the center of the top plate portion 1A in the width direction towards the corner component 1Ec within the top plate side component 1Ea. There is no problem as long as the starting position of the input of bending force to the top plate side component 1Ea is at the midpoint of the width direction of the top plate portion 1A within the top plate side component 1Ea. The starting position of the input of bending force to the top plate side component 1Ea should be at least 0 mm away from the boundary between the corner component 1Ec and the top plate side component 1Ea, preferably at least 3 mm away. Here, through experiments, it was confirmed that compared to simultaneously inputting bending force to both the top plate side component 1Ea and the corner component 1Ec, by performing stamping with the starting position of the bending force input based on the top 12A of the second lower die 12 separated from the boundary between the corner component 1Ec and the top plate side component 1Ea by 0 mm or more, preferably 3 mm or more, the thickness reduction rate at the corner component 1Ec is improved. In particular, by separating it by 3 mm or more from the corner component 1Ec, the starting position of the bending force input based on the top 12A of the second lower die 12 can be more reliably set to be inside the corner component 1Ec.

[0134] In this embodiment, it is preferable to complete the forming of the outward flange portion 1E while constraining at least a portion (e.g., the region that forms the top plate portion) of the region in the metal portion that forms a U-shaped (L-shaped) cross section. In this case, the first forming process and the second forming process can be performed in one stamping operation.

[0135] Here, by forming the outward flange portion 1E together with the forming based on the first forming process, the springback of the longitudinal wall portion 1C relative to the top plate portion 1A can be suppressed, and the shape change during demolding can be suppressed to a small extent.

[0136] The first forming process and the second forming process can also be performed using different molds.

[0137] In addition, after the second forming process, there may be a precision pressing process to improve the accuracy of the shape and size.

[0138] (Stamping forming device)

[0139] Next, an example of a stamping forming apparatus for performing a method for manufacturing the shape of a stamped part in this embodiment will be described.

[0140] As a die for stamping, this embodiment includes a first upper die and a second lower die for performing a first forming process, and a second upper die and a second lower die for performing a second forming process.

[0141] In this embodiment, the apparatus is the same as in the first embodiment, and an example is shown where the first upper die and the second upper die are composed of a single upper die 10 (punch die) (see reference). Figure 3 Furthermore, the first lower die 11 and the second lower die 12 are arranged in a configuration that is offset along the long side of the top plate portion 1A. Therefore, stamping for the first forming process and stamping for the second forming process can be performed in a single stamping operation.

[0142] Similar to the apparatus of the first embodiment, as a mold structure that makes the first upper mold 10 and the first lower mold 11, and the second upper mold and the second lower mold 12 independent, it may also be an apparatus structure in which the first upper mold 10 and the first lower mold 11, and the second upper mold and the second lower mold 12 are individually set on a stamping machine to perform stamping processing.

[0143] <1st upper mold 10 and 1st lower mold 11>

[0144] The first upper mold 10 and the first lower mold 11 are molds used to perform the first forming process.

[0145] Since the structure of the first upper mold 10 and the first lower mold 11 is the same as that of the device in the first embodiment, the description is omitted (see reference). Figure 3 ).

[0146] <The second upper mold and the second lower mold 12>

[0147] The second upper mold and the second lower mold 12 are molds used to perform the second forming process.

[0148] Since the structure of the second upper mold and the second lower mold 12 is the same as that of the device in the first embodiment, the description is omitted (see reference). Figure 3 ).

[0149] <Forming method using stamping equipment>

[0150] An example of a manufacturing method for producing a stamped article 1 by performing the first forming process and the second forming process using the above-described stamping forming apparatus will be described.

[0151] here, Figure 3 This is the state before molding begins. However, considering only the lower mold, Figure 3 The vertical (stroke direction) positional relationship between the first lower die 11 and the second lower die 12 shown is the positional relationship at the end of the first forming process and the second forming process, as well as in the initial state.

[0152] That is, in Figure 3 In the arrangement of the first lower die 11 and the second lower die 12, the inclined surface 12B of the second lower die 12 is displaced further in the stamping direction (upward) than the punch shoulder 11C of the first lower die 11. Specifically, on the opposite side of the punch shoulder 11C, a portion of the surface 12C of the second lower die 12 is exposed, allowing bending force to be input to the corner component 1Ec via the inclined surface 12B. In this state, bending force is also input to the corner component 1Ec.

[0153] In contrast, in this embodiment, firstly, initially, from Figure 3 The state causes the first lower die 11 to travel an upward stroke S relative to the second lower die 12, thus becoming Figure 7 The state.

[0154] exist Figure 7 In this state, the top 12A of the second lower die 12 is positioned further in the stamping direction than the first top plate surface 11A of the first lower die 11 (in the... Figure 7The middle part (top) protrudes. However, the inclined surface 12B of the second lower die 12 is displaced further downward in the stamping direction than the punch shoulder 11C of the first lower die 11. Specifically, in the arrangement direction of the first lower die 11 and the second lower die 12, the surface 12C of the second lower die 12 is not exposed on the opposite side (inner side) of the punch shoulder 11C. Therefore, it is in a state where bending force is not input to the corner component 1Ec through the inclined surface 12B. That is, it is in a state where the surface 12C of the second lower die 12 cannot be seen above the punch shoulder 11C of the first lower die 11, that is, at the position of the punch shoulder 11C, the inclined surface 12B is located below or at the same height.

[0155] In addition, Figure 7 In the middle, for the lower dies 11 and 12, the upper direction is the stamping direction, and for the upper die 10, the lower direction is the stamping direction.

[0156] <Step 1 in the second embodiment>

[0157] The first step in the second embodiment will be described.

[0158] First, the first lower die 11 is made to perform an upward stroke, and the first lower die 11 and the second lower die 12 are set as follows: Figure 7 The state.

[0159] Next, the upper die 10 is pressed relative to the lower dies 11 and 12 to perform a part of the first forming process and the second forming process.

[0160] Once the first process is completed, the blank is formed into... Figure 8 The shape shown. In Figure 8 In the shape shown, the blank is bent at the position of the convex ridge portion 1B to form a cross-sectional コ shape (cross-sectional L shape), and at the same time, it is also bent at the position of the concave ridge portion 1D to form a part of the outwardly protruding flange portion 1E.

[0161] However, in this first process, bending force is input to at least a portion of the longitudinal wall side component 1Eb and the top plate side component 1Ea, but bending force is not input to the corner component 1Ec. Alternatively, bending force is input to the corner component 1Ec only partially.

[0162] In this first process, as part of the second forming process, bending forces are sequentially applied to the longitudinal wall side component 1Eb and the top plate side component 1Ea toward the corner component 1Ec side.

[0163] Furthermore, even if the first process is completed, the input of bending force to the longitudinal wall side component 1Eb and the top plate side component 1Ea may not be completed.

[0164] <Second step in the second embodiment>

[0165] Next, the second step in the second embodiment will be described.

[0166] In the second process, with the metal plate constrained by the first lower die 11 and the upper die 10, the relative position (vertical position) of the first lower die 11 and the second lower die 12 changes from... Figure 7 The state begins as Figure 3 The die moves downwards in that state. Specifically, the first lower die 11, which has been punched upwards, and the upper die 10 are punched downwards together. Thus, following the processing in the first step, the second step is executed.

[0167] In the second step, if the input of bending force to the longitudinal wall side component 1Eb and the top plate side component 1Ea in the first step is not completed, the input of bending force to the remaining longitudinal wall side component 1Eb and the top plate side component 1Ea is sequentially performed towards the corner component 1Ec. In the second step, the input of bending force to the corner component 1Ec is then initiated, and the outward flange portion 1E is formed.

[0168] Thus, in this embodiment, in the first step, the metal plate is bent at the convex ridge portion to form a U-shaped cross section (L-shaped cross section), and at the concave ridge portion to form a portion of the outwardly protruding flange. Furthermore, in the second step, the outwardly protruding flange is formed. However, when bending at the convex ridge portion to form a U-shaped cross section (L-shaped cross section), it is preferable not to initiate the input of bending force to the corner component 1Ec.

[0169] With this treatment, the pre-stroke amount of the first lower die 11 can be reduced. That is, if the first lower die 11 is pre-stroked slightly upward and the upper die 10 is lowered for stamping, then the first lower die 11 only needs to be returned to the initial position for the stroke.

[0170] (Other actions)

[0171] In this embodiment, as the first forming process, the regions of the metal plate 2 that form the top plate portion 1A and the longitudinal wall portion 1C are clamped by the first upper die 10 and the first lower die 11. This forms the metal plate 2 into a U-shaped cross-section (L-shaped cross-section). This first forming process alone, as described in the first embodiment (see [reference]... Figure 6 The region of the outwardly projecting flange 1E extends laterally from the first upper die 10 and the first lower die 11 (in... Figure 6 (The middle section is on the left side) extends out in a cantilever beam shape.

[0172] In contrast, in this embodiment, during the first step, a portion of the second forming process is performed together with the first forming process. Then, as the second step, the second forming process continues to form the outwardly projecting flange.

[0173] Furthermore, in the second process, the metal plate 2 is clamped by the first upper mold 10 and the first lower mold 11. Therefore, the metal plate 2 becomes difficult to move in both the width direction of the top plate portion 1A and the height direction of the longitudinal wall portion 1C. In this embodiment, in this state, the second forming process continues to complete the formation of the outwardly projecting flange portion 1E.

[0174] Here, by initiating the second forming process, the protruding mountain-shaped second lower die 12 is raised relative to the upper die 10 (approaching the second upper die), and the inclined surface 12B of the second lower die 12 abuts against the longitudinal wall side component 1Eb from the lower end side upwards. Therefore, a bending force is input from the lower side to the upper side towards the region of the outwardly projecting flange 1E, which is continuous with the longitudinal wall 1C, and this region is held between the surface 12C of the second lower die 12 and the surface 10E of the upper die 10. Thus, the longitudinal wall side region 1Eb of the outwardly projecting flange 1E is formed by bending from the lower side upwards at the concave ridge portion 1D (see reference). Figure 5 ).

[0175] At this time, the longitudinal wall side region 1Eb is formed sequentially from the lower side (lower end) to the upper side, but the amount formed is small. In addition, the concave ridge portion 1D at this position extends in a straight line or near-straight line along the moving direction of the second lower die 12. Therefore, it is possible to achieve a state where the strain input into the longitudinal wall side region 1Eb through this forming is also small.

[0176] Midway through forming the side region 1Eb of the longitudinal wall, such as Figure 5 As shown, the top 12A of the mountain-shaped structure of the second lower die 12 contacts the portion of the top plate side component 1Ea that is continuous with the central portion in the width direction of the top plate portion 1A. As a result, a bending force is applied to the top plate side component 1Ea. Alternatively, the bending force can be applied to the top plate side component 1Ea before the longitudinal wall side region 1Eb side.

[0177] At this time, taking the portion of the top plate side component 1Ea that is continuous with the central portion of the top plate portion 1A in the width direction as the center, the top plate side component 1Ea is lifted upward. As a result, strain occurs in the portion of the top plate side component 1Ea that is continuous with the central portion of the top plate portion 1A in the width direction.

[0178] Furthermore, if the forming of the longitudinal wall side region 1Eb from the lower side approaches the corner component 1Ec, it becomes a state in which the relatively rigid part is forcibly bent. Therefore, the shoulder edge (the corner extending along the mountain shape) of the second lower mold 12 is straightened and strain is generated.

[0179] Furthermore, as the second lower die 12 rises, it develops towards the corner forming portion 1Ec while simultaneously forming the longitudinal wall side region 1Eb and the top plate side region 1Ea. At this time, strain is generated evenly in the longitudinal wall side region 1Eb and the top plate side region 1Ea.

[0180] Next, the second lower die 12 rises, and before the corner component 1Ec is fully bent up, the curved ridge at the concave ridge portion 1D is nearly straight. Therefore, even if the corner component 1Ec is bent up, the reduction rate of plate thickness at the corner component 1Ec can be suppressed to a small extent.

[0181] In this embodiment, based on the mechanism described above, the metal plate 2 is formed into a U-shaped cross section (L-shaped cross section), and a portion of the outwardly projecting flange portion 1E is formed. Furthermore, after the U-shaped cross section is formed, the outwardly projecting flange portion 1E continues to be formed, thereby forming the outwardly projecting flange portion 1E. Finally, a corner portion is formed on the outwardly projecting flange portion 1E.

[0182] As a result, in this embodiment, the strain of the input outward flange portion 1E is dispersed. In particular, the strain of the edge-side region 1Ec can be dispersed to the longitudinal wall-side region 1Eb and the top plate-side region 1Ea. Therefore, the concentration of strain in the edge-side region 1Ec can be suppressed, thereby improving the plate thickness reduction rate at the edge-side region 1Ec. As a result, it is possible to manufacture a flange with a wider flange width in the edge-side region 1Ec (corner portion) of the outward flange portion 1E. Figure 1 , Figure 2 The stamped product 1 shown.

[0183] As described above, according to this embodiment, a saddle-shaped stamped product having a top plate portion, a longitudinal wall portion, and an outwardly projecting flange portion formed across the long side end of the top plate portion and the longitudinal wall portion can be formed with a simpler mold structure.

[0184] In this embodiment, as described above, the second forming process can begin before or simultaneously with the first forming process. Preferably, the first forming process begins first.

[0185] "Variations"

[0186] Here, variations of the first and second embodiments will be described.

[0187] (Variation Example 1)

[0188] The profile shape of the inclined surface 12B of the second lower mold 12, which faces away from the top 12A, may not be a straight line (see reference). Figure 9 (a)). As long as the slope shape is oriented in the opposite direction to the stamping direction the further away from the top 12A, it is acceptable.

[0189] exist Figure 9 Other examples of the profile shape of inclined plane 12B are shown in (b) and (c). Figure 9 (b) is the profile shape of the inclined plane 12B, which becomes oriented towards the stamping direction (in Figure 9 An example of a convex curved shape (with the upper side in the middle). Figure 9 (c) is an example of a curved shape in which the profile of the inclined plane 12B is a convex shape in the opposite direction to the stamping direction.

[0190] exist Figure 9 Of (a) to (c), the preferred option is... Figure 9 The curve shape of (c). In Figure 9 In (b) and (c), a curved shape formed by bending at inflection point Q is illustrated, that is, a curved shape formed by connecting two straight lines at inflection point Q. In this case, it is preferable to set the position of inflection point Q, which has the maximum vertical displacement relative to the straight line shape, to correspond to the punch shoulder 11C. That is, it is preferable to set the position of inflection point Q and its vicinity as the input point for inputting bending force to corner component 1Ec.

[0191] The shape of the curve mentioned above can also be an arc, etc.

[0192] (Variation Example 2)

[0193] In the above description, an example was given where the cross-sectional shape of the top 12A, viewed from the long side of the top plate, is an arc shape bulging in the stamping direction. However, as in Figure 10 As illustrated in the example, the cross-sectional shape of the top 12A can also be flat (see reference). Figure 10 (a)). Additionally, the cross-sectional shape of the top 12A can also be irregular (see [reference]). Figure 10 (b)

[0194] If the width of the top 12A is smaller than the width of the top plate portion, it can be configured such that only the top 12A abuts against the side component 1Ea of the top plate portion. Therefore, the cross-sectional shape of the top 12A is not limited.

[0195] "First Embodiment"

[0196] An embodiment based on the first embodiment will be described.

[0197] Here, it is assumed Figure 1 and Figure 2 The manufacturing of the stamped part 1 was evaluated using a saddle-shaped stamped part 1 as shown.

[0198] The metal sheet 2 was made of SPFC980Y steel with a thickness of 1.4 mm. Furthermore, the dimensions of the stamped product 1 were set as follows: the width of the top plate portion 1A was set to 84 mm, and the height of the longitudinal wall portion 1C was set to 100 mm. Moreover, stamping based on this embodiment (inventive example) and a comparative stamping method (comparative example) were performed.

[0199] Furthermore, in the comparative example, upper and lower dies with the same forming surfaces as the intended stamped article 1 were used, and forming was performed by a backing plate (backing plate pressure: 15 tons).

[0200] Furthermore, in this embodiment, the punch angle α of the second lower die 12 is set to 90 degrees. Additionally, the contour shape of the inclined surface 12B is a straight line.

[0201] The analysis results are as follows Figure 11 As shown. In Figure 11 In the middle, the ridge section (1Ec) corresponds to the side region of the ridge section. Additionally, in Figure 11 In the diagram, the horizontal axis represents the distance from a position continuous with the center of the top plate portion 1A in the width direction to the width direction of the top plate portion 1A. (This will be discussed later.) Figure 12 The same applies to China.

[0202] according to Figure 11 It can be seen that, compared with the comparative example, in the invention example, the strain is distributed over a wide range in the width direction of the top plate portion 1A. Furthermore, it can be seen that the thickness reduction rate of the edge portion side region 1Ec, which serves as a corner portion, is lower in the invention example.

[0203] Furthermore, in the invention example, the effect was evaluated by changing the punch angle α of the second lower die 12.

[0204] The analysis result is as follows: Figure 12 As shown.

[0205] according to Figure 12 It was also confirmed that regardless of whether the punch angle α was changed from 90 degrees to the acute angle side or the obtuse angle side, the improvement effect on the plate thickness reduction rate at the edge side region 1Ec was the same as when the punch angle α was 90 degrees. Figure 12 The diagram illustrates cases where the punch angle α ranges from 60 degrees to 180 degrees. For example... Figure 12 As shown, when the punch angle α is set to 60 degrees and 180 degrees, it is also confirmed that the improvement trend of the plate thickness reduction rate at the edge side region 1Ec, which is the corner part, is the same as that in the case of 90 degrees.

[0206] in addition, Figure 13This diagram is derived based on the change in the plate thickness reduction rate in the edge section side region 1Ec and the surrounding area (the longitudinal wall side component 1Eb side and the top plate side component 1Ea side) caused by the change in the punch angle α. Figure 13 It can be seen that the maximum reduction rate of plate thickness is smallest when the punch angle α is around 110 degrees. In contrast, the more acute the punch angle α, the greater the reduction rate of plate thickness at the top plate side component 1Ea. Conversely, the more obtuse the punch angle α, the greater the reduction rate of plate thickness at the longitudinal wall side component 1Eb. Based on this, a punch angle α of 80 to 140 degrees is preferred. More preferably, it is 90 to 120 degrees, and even more preferably, it is 100 to 110 degrees.

[0207] "Second Embodiment"

[0208] Next, an embodiment based on the second implementation method will be described.

[0209] Here, it is assumed Figure 1 and Figure 2 The manufacturing of the stamped part 1 was evaluated using a saddle-shaped stamped part 1 as shown.

[0210] The metal sheet 2 was made of SPFC980Y steel with a thickness of 1.4 mm. Furthermore, the dimensions of the stamped product 1 were set as follows: the width of the top plate portion 1A was set to 84 mm, and the height of the longitudinal wall portion 1C was set to 100 mm. Moreover, stamping based on this embodiment (inventive example) and a comparative stamping method (comparative example) were performed.

[0211] In the comparative example, upper and lower dies with the same forming surfaces as the intended stamped part 1 were used, and forming was performed by a backing plate (backing plate pressure: 15 tons).

[0212] Furthermore, in the embodiment, the punch angle α of the second lower die 12 is set to 90 degrees.

[0213] The analysis results are as follows Figure 14 As shown. In Figure 14 In the middle, the horizontal axis represents the position of the first lower die 11 from its initial position (see reference) in order to perform the first process. Figure 3 The upward stroke S (refer to) Figure 7 ).

[0214] exist Figure 14 In the case of a stroke S = 79 mm, when the metal plate is formed into a U-shaped cross section through the first process, the top 12A of the second lower die 12 is in contact with the metal plate 2 but has not yet started to bend and form.

[0215] By reducing the stroke amount S, the top 12A of the second lower die 12 is configured to protrude relative to the first lower die 11. Therefore, when forming the metal plate 2 into a U-shaped cross section, the forming amount of the outward flange portion 1E also increases.

[0216] On the other hand, in the region where the stroke amount S is less than 44 mm, the protrusion of the top 12A of the second lower die 12 increases, and while being formed into a cross-sectional U-shape, a part of the top plate side component 1Ea is also formed.

[0217] according to Figure 14 As can be seen, compared with the usual method (comparative example), in the second embodiment, the reduction in plate thickness of the ridge side region 1Ec, which is the ridge side region, decreases independently of the stroke of the first lower die 11. In addition, it can be confirmed that even if the stroke amount S is reduced to 29 mm, the reduction in plate thickness of the longitudinal wall side component 1Eb side and the top plate side component 1Ea side does not worsen, and strain is efficiently dispersed.

[0218] in addition, Figure 15 This diagram is derived based on the change in the plate thickness reduction rate in the edge section side region 1Ec and the surrounding area (the longitudinal wall side component 1Eb side and the top plate side component 1Ea side) caused by the change in the punch angle α. Figure 15 It can be seen that the maximum reduction rate of plate thickness is smallest when the punch angle α is around 110 degrees. In contrast, the more acute the punch angle α, the greater the reduction rate of plate thickness at the top plate side component 1Ea. Conversely, the more obtuse the punch angle α, the greater the reduction rate of plate thickness at the longitudinal wall side component 1Eb. Based on this, a punch angle α of 80 to 140 degrees is preferred. More preferably, it is 90 to 120 degrees, and even more preferably, it is 100 to 110 degrees.

[0219] Furthermore, since the influence of the shape of the inclined surface 12B of the second lower die 12 on the reduction of the plate thickness of the flange portion 1E is investigated by performing only the second forming process, the inclined surface 12B is also bent upwards in a curved shape. Figure 9 (b) and the downward-convex curve shape ( Figure 9 The parsing was performed on (c).

[0220] The analysis results are as follows Figure 16 As shown. Comparing with the usual method (comparative example), it can be seen that the reduction in plate thickness of the edge region 1Ec decreases regardless of the shape of the inclined surface 12B. Furthermore, it can be seen that in the shape where the inclined surface 12B is bent downwards, compared with the straight shape (…), the reduction in plate thickness is… Figure 9 Compared to (a), the reduction in plate thickness of the edge region 1Ec, which is the corner, is reduced. Therefore, in cases of uneven strain distribution, the dispersion can be adjusted by changing the shape of the inclined surface 12B.

[0221] (other)

[0222] This disclosure can also adopt a structure like the one below.

[0223] (1) A stamped article comprising: a top plate portion; a longitudinal wall portion that is continuous in the width direction with the top plate portion via a convex ridge portion; and an outwardly projecting flange portion that is continuous in the long side direction end of the top plate portion, the long side direction end of the convex ridge portion, and the long side direction end of the longitudinal wall portion via a concave ridge portion.

[0224] When manufacturing the above-mentioned stamped products using metal sheets

[0225] The metal plate is bent at the position of the convex ridge to form an L-shaped cross section. After the L-shaped cross section is formed or during the formation of the L-shaped cross section, it is bent at the position of the concave ridge to form the outwardly protruding flange.

[0226] (2) After the L-shaped cross-section is formed, the outwardly protruding flange is formed.

[0227] The process of bending the aforementioned convex ridge portion into an L-shaped cross-section is performed while the area that forms the aforementioned outwardly protruding flange portion has been released.

[0228] According to this structure, the input of strain direction in the region of the outward flange when forming an L-shaped cross section can be suppressed to a smaller extent.

[0229] (3) While constraining the top plate portion and the longitudinal wall portion into an L-shaped cross section, the process of forming the outward flange portion is performed.

[0230] According to this structure, the first and second processes can be performed in a single stamping process.

[0231] (4) When the concave ridge portion is bent to form the outward flange portion, a bending force is applied to the region in the region that is the outward flange portion, which is continuous with the long side end of the top plate portion and the long side end of the longitudinal wall portion. Then, a bending force is applied to the region that is continuous with the long side end of the concave ridge portion and the convex ridge portion.

[0232] At this time, for the bending force input to the region that is continuous along the long side of the concave ridge portion and the top plate portion, it is preferable to input the initial bending force at a position at least 0 mm away from the end of the convex ridge portion. "Separation from the end of the convex ridge portion" means separation from the end of the arc of the convex ridge portion, which is composed of a cross-sectional arc shape or the like (the boundary with other parts).

[0233] According to this structure, the strain (thickness reduction rate) dispersed in the outward flange portion to the concave ridge portion 1D (corner portion) can be more reliably suppressed to a smaller value (see reference). Figure 11 ).

[0234] As described in the embodiment, after forming begins from a position away from the concave ridge portion 1D in the outward flange portion, the forming of the concave ridge portion 1D is performed.

[0235] (5) A stamped article comprising: a top plate portion; a longitudinal wall portion that is continuous in the width direction with the top plate portion via a convex ridge portion; and an outwardly projecting flange portion that is continuous in the long side direction end of the top plate portion, the long side direction end of the convex ridge portion, and the long side direction end of the longitudinal wall portion via a concave ridge portion.

[0236] When manufacturing the above-mentioned stamped products using metal sheets

[0237] The metal plate is bent at the convex ridge portion to form an L-shaped cross-section, and bent at the concave ridge portion to form the outwardly protruding flange portion.

[0238] When the outwardly convex flange is formed by bending at the location of the concave ridge portion, a bending force is initially applied to the region in the area that forms the outwardly convex flange, which is continuous with the long side end of the top plate portion via the concave ridge portion and with the long side end of the longitudinal wall portion. Subsequently, a bending force is applied to the region that is continuous with the long side end of the convex ridge portion via the concave ridge portion.

[0239] After the L-shaped profile is formed, the forming of the region in the outward flange portion that is continuous with the long side end of the concave ridge portion and the convex ridge portion is completed.

[0240] Regarding the bending force input to the region that is continuous along the long side of the concave ridge portion and the top plate portion, it is preferable to input the initial bending force at a position where it is separated from the end of the convex ridge portion by 0 mm or more, preferably by 3 mm or more. "Separated from the convex ridge portion" means separated from the end of the arc of the convex ridge portion with its circular cross-section.

[0241] According to this structure, the strain (thickness reduction rate) dispersed in the outward flange portion to the concave ridge portion 1D (corner portion) can be more reliably suppressed to a smaller value (see reference). Figure 8 ).

[0242] As described in the embodiment, after forming begins from a position away from the concave ridge portion 1D in the outward flange portion, the forming of the concave ridge portion 1D is performed.

[0243] (6) Regarding the bending force input to the region that is continuous with the long side end of the concave ridge portion and the top plate portion, the initial bending force is input at a position that is more inward than the convex ridge portion.

[0244] According to this structure, the strain (thickness reduction rate) dispersed in the outward flange portion to the concave ridge portion 1D (corner portion) can be more reliably suppressed to a smaller value.

[0245] (7) The shape of the stamped article described above includes: a top plate portion; left and right longitudinal wall portions that are continuous with the width direction sides of the top plate portion via left and right convex ridge portions; and an outward flange portion that is continuous with the long side end of the top plate portion, the long side end of the left and right convex ridge portions, and the long side end of the left and right longitudinal wall portions via concave ridge portions.

[0246] Based on this structure, saddle-shaped stamped products are manufactured.

[0247] (8) A stamping forming apparatus for manufacturing stamped articles from sheet metal, the stamped articles comprising: a top plate portion; a longitudinal wall portion continuous in the width direction of the top plate portion via a convex ridge portion; and an outwardly projecting flange portion continuous in the long-side direction end of the top plate portion, the long-side direction end of the convex ridge portion, and the long-side direction end of the longitudinal wall portion via a concave ridge portion, wherein...

[0248] The above-mentioned stamping forming apparatus includes:

[0249] The first upper mold and the first lower mold have forming surfaces capable of forming the regions of the top plate portion and the longitudinal wall portion at the locations that form the aforementioned convex ridge portions, thereby forming the top plate portion and the longitudinal wall portion continuous with the top plate portion; and

[0250] The second lower mold bends the metal plate at the concave ridge to form the outwardly protruding flange.

[0251] The forming surface of the portion of the second lower mold that forms the outward flange portion by inputting bending force into the region of the outward flange portion has a top and a pair of continuous inclined surfaces on the left and right sides of the top when viewed from the long side direction of the top plate portion, and the whole has a mountain-shaped shape that protrudes in the bending direction of the outward flange portion.

[0252] The top of the mountain-shaped portion is configured to abut against a region that is continuous with the long side end of the top plate portion via the concave ridge portion in the region that forms the outward flange portion.

[0253] According to this structure, the width of the corner portion of the outward flange portion located at the end of the long side direction can be set to be wider.

[0254] Additionally, for example, it is not necessary to... Figure 17 It is cut in such a way that the width of the corner component 1Ec of the outwardly protruding flange becomes narrower, such as Figure 1 As shown, even if the width is set to be the same as other parts, it can suppress cracking and other problems.

[0255] (9) It has a second upper die that is opposite to the second lower die in the stamping direction.

[0256] The metal plate formed by the second lower mold is a metal plate formed by the first upper mold and the first lower mold.

[0257] (10) The first upper mold and the second upper mold mentioned above are composed of one upper mold.

[0258] The first lower mold and the second lower mold are configured to be offset in the long side direction of the top plate portion.

[0259] According to this structure, the outward flange portion can be formed in a single stamping process.

[0260] (11) The first lower die and the second lower die are configured to be offset in the long side direction of the top plate portion, and the first lower die can perform a stroke in the direction along the stamping direction relative to the second lower die.

[0261] According to this structure, the outward flange portion can be formed in a single stamping process.

[0262] In addition, it can also suppress the stroke of the first die to a smaller amount.

[0263] (12) For the above-mentioned mountain shape, the punch angle formed by the cross angle connecting the left and right slopes that form the mountain shape is wider than twice the angle obtained by subtracting 90 degrees from the angle formed by the top plate portion and the longitudinal wall portion in the metal plate formed by the first upper die and the first lower die.

[0264] According to this structure, it is set to start forming from the lower end of the longitudinal wall side component in the outward flange portion through the second lower mold, and then start forming from the center portion of the top plate side component, so that the forming position moves toward the corner component.

[0265] Therefore, the strain (thickness reduction rate) dispersed in the outward flange portion to the concave ridge portion 1D (corner portion) can be more reliably suppressed to a smaller value (see reference). Figure 11 ).

[0266] (13) The above-mentioned punch angle is within the range of 60 degrees to 180 degrees.

[0267] (14) The outline shape of the slope in the above-mentioned mountain shape becomes a curved shape that bulges out in the opposite direction to the stamping direction along the inclination direction of the slope.

[0268] According to this structure, the reduction in plate thickness at the corner can be set to be smaller depending on the degree of strain.

[0269] (15) A manufacturing method comprising manufacturing the above-mentioned stamped article using a stamping apparatus of the present disclosure, wherein...

[0270] Using the first upper die and the first lower die, the regions of the metal plate that constitute the top plate portion and the longitudinal wall portion are stamped into an L-shaped cross-section.

[0271] Using the second upper die and the second lower die, the outward flange portion is formed on the metal sheet that has been stamped into the L-shaped cross-section.

[0272] According to this structure, the strain (thickness reduction rate) dispersed in the outward flange portion to the concave ridge portion 1D (corner portion) can be more reliably suppressed to a smaller value.

[0273] (16) In the state where the metal plate is constrained into a cross-sectional L-shape by the first upper mold and the first lower mold, the outward flange portion is formed by the second upper mold and the second lower mold.

[0274] According to this structure, the strain (thickness reduction rate) dispersed in the outward flange portion to the concave ridge portion 1D (corner portion) can be more reliably suppressed to a smaller value.

[0275] (17) A manufacturing method comprising manufacturing the above-mentioned stamped article using a stamping apparatus of the present disclosure, wherein...

[0276] While using the first upper die and the first lower die to stamp the area of ​​the metal plate that becomes the top plate portion and the longitudinal wall portion into a cross-sectional L-shape, the second lower die is used to form a part of the outward flange portion.

[0277] According to this structure, the strain (thickness reduction rate) dispersed in the outward flange portion to the concave ridge portion 1D (corner portion) can be more reliably suppressed to a smaller value.

[0278] The entire contents of Japanese Patent Application No. 2020-148121 (filed September 3, 2020) and Japanese Patent Application No. 2021-047187 (filed March 22, 2021), which claim priority in this application, are incorporated herein by reference. Although a limited number of embodiments have been described herein, the scope of the claims is not limited thereto, and modifications based on the embodiments disclosed above will be apparent to those skilled in the art.

[0279] Explanation of reference numerals in the attached figures

[0280] 1… Stamped part; 1A… Top plate portion; 1B… Convex ridge portion; 1C… Longitudinal wall portion; 1D… Concave ridge portion; 1E… Outward flange portion; 1Ea… Top plate side area (top plate side component); 1Eb… Longitudinal wall side area (longitudinal wall side component); 1Ec… Ridge side area (corner component); 2… Metal plate; 10… Upper die (first upper die, second upper die); 11… First lower die; 12… Second lower die; 12A… Top; 12B… Inclined surface; α… Punch angle of the second lower die.

Claims

1. A method for manufacturing a stamped product, characterized in that, The stamped product comprises: Top section; The longitudinal wall portion is continuous in the width direction with the top plate portion via the convex ridge portion; and The outwardly convex flange portion is continuous with the long-side end of the concave ridge portion, the long-side end of the convex ridge portion, and the long-side end of the longitudinal wall portion. When manufacturing the stamped product using sheet metal... The metal plate is bent into an L-shaped cross-section at the convex ridge portion, and after the L-shaped cross-section is formed, it is bent at the concave ridge portion to form the outwardly protruding flange portion. The process of bending the convex ridge portion into an L-shaped cross-section is performed while the area that forms the outward flange portion is released. When the outward flange is formed by bending at the position of the concave ridge portion, a bending force is first applied to the region in the area that becomes the outward flange portion, which is continuous with the long side end of the top plate portion and the long side end of the longitudinal wall portion, and then a bending force is applied to the region that is continuous with the long side end of the convex ridge portion.

2. The method for manufacturing stamped articles according to claim 1, characterized in that, After the L-shaped cross-section is formed, the outwardly protruding flange is formed. While constraining the top plate portion and the longitudinal wall portion into the L-shaped cross-section, the process of forming the outward flange portion is performed.

3. A method for manufacturing a stamped product, characterized in that, The stamped product comprises: Top section; The longitudinal wall portion is continuous in the width direction with the top plate portion via the convex ridge portion; and The outwardly convex flange portion is continuous with the long-side end of the concave ridge portion, the long-side end of the convex ridge portion, and the long-side end of the longitudinal wall portion. When manufacturing stamped parts from sheet metal The metal plate is bent at the convex ridge portion to form an L-shaped cross-section, and bent at the concave ridge portion to form the outwardly protruding flange portion. When the outwardly convex flange is formed by bending at the location of the concave ridge portion, a bending force is initially applied to the region in the area that forms the outwardly convex flange, which is continuous with the long-side end of the top plate portion via the concave ridge portion and with the long-side end of the longitudinal wall portion. Then, a bending force is applied to the region that is continuous with the long-side end of the convex ridge portion via the concave ridge portion. After the L-shaped profile is formed, the forming of the region in the outward flange portion that is continuous with the long side end of the concave ridge portion and the convex ridge portion is completed.

4. The method for manufacturing a stamped article according to any one of claims 1 to 3, characterized in that, For the bending force inputted in the region that is continuous along the long side of the concave ridge portion and the top plate portion, the initial bending force is inputted at a position that is inside the convex ridge portion.

5. The method for manufacturing a stamped article according to any one of claims 1 to 3, characterized in that, The stamped product has the following shape: Top section; The left and right longitudinal wall portions are continuous with the top plate portion in the width direction via the left and right convex ridge portions; and The outwardly protruding flange is continuous via the concave ridge portion and the long side end of the top plate portion, the long side end of the left and right convex ridge portions, and the long side end of the left and right longitudinal wall portions.

6. A stamping apparatus for manufacturing stamped articles from sheet metal. The stamped product comprises: Top section; The longitudinal wall portion is continuous in the width direction with the top plate portion via the convex ridge portion; and The outwardly convex flange portion is continuous with the long-side end of the concave ridge portion, the long-side end of the convex ridge portion, and the long-side end of the longitudinal wall portion. The stamping forming apparatus is characterized by having: The first upper mold and the first lower mold have forming surfaces capable of forming the regions of the top plate portion and the longitudinal wall portion at the locations that become the convex ridge portion, thereby forming the top plate portion and the longitudinal wall portion continuous with the top plate portion; and The second lower die bends the metal plate at the concave ridge portion to form the outwardly protruding flange portion. The forming surface of the portion of the second lower mold that forms the outward flange by inputting bending force into the region of the outward flange, when viewed from the long side of the top plate, has a top and a pair of continuous inclined surfaces on the left and right sides of the top, and the whole is a mountain-shaped shape that protrudes in the bending direction of the outward flange. The top of the mountain-shaped portion is configured to abut against a region that is continuous with the long side end of the top plate portion via the concave ridge portion in the region of the outwardly protruding flange portion.

7. The stamping forming apparatus according to claim 6, characterized in that, It has a second upper die that is opposite to the second lower die in the stamping direction. The metal plate formed by the second lower mold is a metal plate formed by the first upper mold and the first lower mold.

8. The stamping forming apparatus according to claim 7, characterized in that, The first upper mold and the second upper mold are composed of a single upper mold. The first lower mold and the second lower mold are configured to be offset in the long side direction of the top plate portion.

9. The stamping forming apparatus according to claim 6, characterized in that, The first lower die and the second lower die are configured to be offset in the long side direction of the top plate portion, and the first lower die is capable of performing a stroke in the direction along the stamping direction relative to the second lower die.

10. The stamping forming apparatus according to any one of claims 6 to 9, characterized in that, For the mountain-shaped shape, the punch angle formed by the intersection angle connecting the left and right inclined surfaces that form the mountain-shaped shape is wider than twice the angle obtained by subtracting 90 degrees from the angle formed by the top plate portion and the longitudinal wall portion in the metal plate formed by the first upper die and the first lower die.

11. The stamping forming apparatus according to claim 10, characterized in that, The punch angle is in the range of 60 degrees to 180 degrees.

12. The stamping forming apparatus according to any one of claims 6 to 9, characterized in that, The contour shape of the inclined surface in the mountain shape is a curved shape that bulges out in the opposite direction to the stamping direction along the inclined direction of the inclined surface.

13. A method for manufacturing a stamped article, wherein the stamped article is manufactured from a metal sheet using the stamping apparatus of claim 7 or 8. The method for manufacturing the stamped product is characterized in that, The first upper die and the first lower die are used to stamp the area of ​​the metal plate that forms the top plate portion and the longitudinal wall portion into an L-shaped cross-section. Using the second upper die and the second lower die, the outward flange portion is formed on the metal plate that has been stamped into the L-shaped cross-section.

14. The method for manufacturing a stamped article according to claim 13, characterized in that, With the metal plate constrained into an L-shaped cross-section by the first upper mold and the first lower mold, the outward flange is formed by the second upper mold and the second lower mold.

15. A method for manufacturing a stamped article, wherein the stamped article is manufactured from a metal sheet using the stamping apparatus of claim 6 or 9. The method for manufacturing the stamped product is characterized in that, While using the first upper die and the first lower die to stamp the area of ​​the metal plate that becomes the top plate portion and the longitudinal wall portion into a cross-sectional L-shape, the second lower die is used to form a part of the outward flange portion.

Images